Search results for: degradation gradient
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2477

Search results for: degradation gradient

227 Transformers in Gene Expression-Based Classification

Authors: Babak Forouraghi

Abstract:

A genetic circuit is a collection of interacting genes and proteins that enable individual cells to implement and perform vital biological functions such as cell division, growth, death, and signaling. In cell engineering, synthetic gene circuits are engineered networks of genes specifically designed to implement functionalities that are not evolved by nature. These engineered networks enable scientists to tackle complex problems such as engineering cells to produce therapeutics within the patient's body, altering T cells to target cancer-related antigens for treatment, improving antibody production using engineered cells, tissue engineering, and production of genetically modified plants and livestock. Construction of computational models to realize genetic circuits is an especially challenging task since it requires the discovery of flow of genetic information in complex biological systems. Building synthetic biological models is also a time-consuming process with relatively low prediction accuracy for highly complex genetic circuits. The primary goal of this study was to investigate the utility of a pre-trained bidirectional encoder transformer that can accurately predict gene expressions in genetic circuit designs. The main reason behind using transformers is their innate ability (attention mechanism) to take account of the semantic context present in long DNA chains that are heavily dependent on spatial representation of their constituent genes. Previous approaches to gene circuit design, such as CNN and RNN architectures, are unable to capture semantic dependencies in long contexts as required in most real-world applications of synthetic biology. For instance, RNN models (LSTM, GRU), although able to learn long-term dependencies, greatly suffer from vanishing gradient and low-efficiency problem when they sequentially process past states and compresses contextual information into a bottleneck with long input sequences. In other words, these architectures are not equipped with the necessary attention mechanisms to follow a long chain of genes with thousands of tokens. To address the above-mentioned limitations of previous approaches, a transformer model was built in this work as a variation to the existing DNA Bidirectional Encoder Representations from Transformers (DNABERT) model. It is shown that the proposed transformer is capable of capturing contextual information from long input sequences with attention mechanism. In a previous work on genetic circuit design, the traditional approaches to classification and regression, such as Random Forrest, Support Vector Machine, and Artificial Neural Networks, were able to achieve reasonably high R2 accuracy levels of 0.95 to 0.97. However, the transformer model utilized in this work with its attention-based mechanism, was able to achieve a perfect accuracy level of 100%. Further, it is demonstrated that the efficiency of the transformer-based gene expression classifier is not dependent on presence of large amounts of training examples, which may be difficult to compile in many real-world gene circuit designs.

Keywords: transformers, generative ai, gene expression design, classification

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226 Isolation of Nitrosoguanidine Induced NaCl Tolerant Mutant of Spirulina platensis with Improved Growth and Phycocyanin Production

Authors: Apurva Gupta, Surendra Singh

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Spirulina spp., as a promising source of many commercially valuable products, is grown photo autotrophically in open ponds and raceways on a large scale. However, the economic exploitation in an open system seems to have been limited because of lack of multiple stress-tolerant strains. The present study aims to isolate a stable stress tolerant mutant of Spirulina platensis with improved growth rate and enhanced potential to produce its commercially valuable bioactive compounds. N-methyl-n'-nitro-n-nitrosoguanidine (NTG) at 250 μg/mL (concentration permitted 1% survival) was employed for chemical mutagenesis to generate random mutants and screened against NaCl. In a preliminary experiment, wild type S. platensis was treated with NaCl concentrations from 0.5-1.5 M to calculate its LC₅₀. Mutagenized colonies were then screened for tolerance at 0.8 M NaCl (LC₅₀), and the surviving colonies were designated as NaCl tolerant mutants of S. platensis. The mutant cells exhibited 1.5 times improved growth against NaCl stress as compared to the wild type strain in control conditions. This might be due to the ability of the mutant cells to protect its metabolic machinery against inhibitory effects of salt stress. Salt stress is known to adversely affect the rate of photosynthesis in cyanobacteria by causing degradation of the pigments. Interestingly, the mutant cells were able to protect its photosynthetic machinery and exhibited 4.23 and 1.72 times enhanced accumulation of Chl a and phycobiliproteins, respectively, which resulted in enhanced rate of photosynthesis (2.43 times) and respiration (1.38 times) against salt stress. Phycocyanin production in mutant cells was observed to enhance by 1.63 fold. Nitrogen metabolism plays a vital role in conferring halotolerance to cyanobacterial cells by influx of nitrate and efflux of Na+ ions from the cell. The NaCl tolerant mutant cells took up 2.29 times more nitrate as compared to the wild type and efficiently reduce it. Nitrate reductase and nitrite reductase activity in the mutant cells also improved by 2.45 and 2.31 times, respectively against salt stress. From these preliminary results, it could be deduced that enhanced nitrogen uptake and its efficient reduction might be a reason for adaptive and halotolerant behavior of the S. platensis mutant cells. Also, the NaCl tolerant mutant of S. platensis with significant improved growth and phycocyanin accumulation compared to the wild type can be commercially promising.

Keywords: chemical mutagenesis, NaCl tolerant mutant, nitrogen metabolism, photosynthetic machinery, phycocyanin

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225 Hierarchical Zeolites as Potential Carriers of Curcumin

Authors: Ewelina Musielak, Agnieszka Feliczak-Guzik, Izabela Nowak

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Based on the latest data, it is expected that the substances of therapeutic interest used will be as natural as possible. Therefore, active substances with the highest possible efficacy and low toxicity are sought. Among natural substances with therapeutic effects, those of plant origin stand out. Curcumin isolated from the Curcuma longa plant has proven to be particularly important from a medical point of view. Due to its ability to regulate many important transcription factors, cytokines, and protein kinases, curcumin has found use as an anti-inflammatory, antioxidant, antiproliferative, antiangiogenic, and anticancer agent. The unfavorable properties of curcumin, such as low solubility, poor bioavailability, and rapid degradation under neutral or alkaline pH conditions, limit its clinical application. These problems can be solved by combining curcumin with suitable carriers such as hierarchical zeolites. This is a new class of materials that exhibit several advantages. Hierarchical zeolites used as drug carriers enable delayed release of the active ingredient and promote drug transport to the desired tissues and organs. In addition, hierarchical zeolites play an important role in regulating micronutrient levels in the body and have been used successfully in cancer diagnosis and therapy. To apply curcumin to hierarchical zeolites synthesized from commercial FAU zeolite, solutions containing curcumin, carrier and acetone were prepared. The prepared mixtures were then stirred on a magnetic stirrer for 24 h at room temperature. The curcumin-filled hierarchical zeolites were drained into a glass funnel, where they were washed three times with acetone and distilled water, after which the obtained material was air-dried until completely dry. In addition, the effect of piperine addition to zeolite carrier containing a sufficient amount of curcumin was studied. The resulting products were weighed and the percentage of pure curcumin in the hierarchical zeolite was calculated. All the synthesized materials were characterized by several techniques: elemental analysis, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, Fourier transform infrared (FT-IR), N2 adsorption, and X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The aim of the presented study was to improve the biological activity of curcumin by applying it to hierarchical zeolites based on FAU zeolite. The results showed that the loading efficiency of curcumin into hierarchical zeolites based on commercial FAU-type zeolite is enhanced by modifying the zeolite carrier itself. The hierarchical zeolites proved to be very good and efficient carriers of plant-derived active ingredients such as curcumin.

Keywords: carriers of active substances, curcumin, hierarchical zeolites, incorporation

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224 A Study on the Quantitative Evaluation Method of Asphalt Pavement Condition through the Visual Investigation

Authors: Sungho Kim, Jaechoul Shin, Yujin Baek

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In recent years, due to the environmental impacts and time factor, etc., various type of pavement deterioration is increasing rapidly such as crack, pothole, rutting and roughness degradation. The Ministry of Land, Infrastructure and Transport maintains regular pavement condition of the highway and the national highway using the pavement condition survey equipment and structural survey equipment in Korea. Local governments that maintain local roads, farm roads, etc. are difficult to maintain the pavement condition using the pavement condition survey equipment depending on economic conditions, skills shortages and local conditions such as narrow roads. This study presents a quantitative evaluation method of the pavement condition through the visual inspection to overcome these problems of roads managed by local governments. It is difficult to evaluate rutting and roughness with the naked eye. However, the condition of cracks can be evaluated with the naked eye. Linear cracks (m), area cracks (m²) and potholes (number, m²) were investigated with the naked eye every 100 meters for survey the cracks. In this paper, crack ratio was calculated using the results of the condition of cracks and pavement condition was evaluated by calculated crack ratio. The pavement condition survey equipment also investigated the pavement condition in the same section in order to evaluate the reliability of pavement condition evaluation by the calculated crack ratio. The pavement condition was evaluated through the SPI (Seoul Pavement Index) and calculated crack ratio using results of field survey. The results of a comparison between 'the SPI considering only crack ratio' and 'the SPI considering rutting and roughness either' using the equipment survey data showed a margin of error below 5% when the SPI is less than 5. The SPI 5 is considered the base point to determine whether to maintain the pavement condition. It showed that the pavement condition can be evaluated using only the crack ratio. According to the analysis results of the crack ratio between the visual inspection and the equipment survey, it has an average error of 1.86%(minimum 0.03%, maximum 9.58%). Economically, the visual inspection costs only 10% of the equipment survey and will also help the economy by creating new jobs. This paper advises that local governments maintain the pavement condition through the visual investigations. However, more research is needed to improve reliability. Acknowledgment: The author would like to thank the MOLIT (Ministry of Land, Infrastructure, and Transport). This work was carried out through the project funded by the MOLIT. The project name is 'development of 20mm grade for road surface detecting roadway condition and rapid detection automation system for removal of pothole'.

Keywords: asphalt pavement maintenance, crack ratio, evaluation of asphalt pavement condition, SPI (Seoul Pavement Index), visual investigation

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223 Adaptative Metabolism of Lactic Acid Bacteria during Brewers' Spent Grain Fermentation

Authors: M. Acin-Albiac, P. Filannino, R. Coda, Carlo G. Rizzello, M. Gobbetti, R. Di Cagno

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Demand for smart management of large amounts of agro-food by-products has become an area of major environmental and economic importance worldwide. Brewers' spent grain (BSG), the most abundant by-product generated in the beer-brewing process, represents an example of valuable raw material and source of health-promoting compounds. To the date, the valorization of BSG as a food ingredient has been limited due to poor technological and sensory properties. Tailored bioprocessing through lactic acid bacteria (LAB) fermentation is a versatile and sustainable means for the exploitation of food industry by-products. Indigestible carbohydrates (e.g., hemicelluloses and celluloses), high phenolic content, and mostly lignin make of BSG a hostile environment for microbial survival. Hence, the selection of tailored starters is required for successful fermentation. Our study investigated the metabolic strategies of Leuconostoc pseudomesenteroides and Lactobacillus plantarum strains to exploit BSG as a food ingredient. Two distinctive BSG samples from different breweries (Italian IT- and Finish FL-BSG) were microbially and chemically characterized. Growth kinetics, organic acid profiles, and the evolution of phenolic profiles during the fermentation in two BSG model media were determined. The results were further complemented with gene expression targeting genes involved in the degradation cellulose, hemicelluloses building blocks, and the metabolism of anti-nutritional factors. Overall, the results were LAB genus dependent showing distinctive metabolic capabilities. Leuc. pseudomesenteroides DSM 20193 may degrade BSG xylans while sucrose metabolism could be furtherly exploited for extracellular polymeric substances (EPS) production to enhance BSG pro-technological properties. Although L. plantarum strains may follow the same metabolic strategies during BSG fermentation, the mode of action to pursue such strategies was strain-dependent. L. plantarum PU1 showed a great preference for β-galactans compared to strain WCFS1, while the preference for arabinose occurred at different metabolic phases. Phenolic compounds profiling highlighted a novel metabolic route for lignin metabolism. These findings will allow an improvement of understanding of how lactic acid bacteria transform BSG into economically valuable food ingredients.

Keywords: brewery by-product valorization, metabolism of plant phenolics, metabolism of lactic acid bacteria, gene expression

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222 Robust Processing of Antenna Array Signals under Local Scattering Environments

Authors: Ju-Hong Lee, Ching-Wei Liao

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An adaptive array beamformer is designed for automatically preserving the desired signals while cancelling interference and noise. Providing robustness against model mismatches and tracking possible environment changes calls for robust adaptive beamforming techniques. The design criterion yields the well-known generalized sidelobe canceller (GSC) beamformer. In practice, the knowledge of the desired steering vector can be imprecise, which often occurs due to estimation errors in the DOA of the desired signal or imperfect array calibration. In these situations, the SOI is considered as interference, and the performance of the GSC beamformer is known to degrade. This undesired behavior results in a reduction of the array output signal-to-interference plus-noise-ratio (SINR). Therefore, it is worth developing robust techniques to deal with the problem due to local scattering environments. As to the implementation of adaptive beamforming, the required computational complexity is enormous when the array beamformer is equipped with massive antenna array sensors. To alleviate this difficulty, a generalized sidelobe canceller (GSC) with partially adaptivity for less adaptive degrees of freedom and faster adaptive response has been proposed in the literature. Unfortunately, it has been shown that the conventional GSC-based adaptive beamformers are usually very sensitive to the mismatch problems due to local scattering situations. In this paper, we present an effective GSC-based beamformer against the mismatch problems mentioned above. The proposed GSC-based array beamformer adaptively estimates the actual direction of the desired signal by using the presumed steering vector and the received array data snapshots. We utilize the predefined steering vector and a presumed angle tolerance range to carry out the required estimation for obtaining an appropriate steering vector. A matrix associated with the direction vector of signal sources is first created. Then projection matrices related to the matrix are generated and are utilized to iteratively estimate the actual direction vector of the desired signal. As a result, the quiescent weight vector and the required signal blocking matrix required for performing adaptive beamforming can be easily found. By utilizing the proposed GSC-based beamformer, we find that the performance degradation due to the considered local scattering environments can be effectively mitigated. To further enhance the beamforming performance, a signal subspace projection matrix is also introduced into the proposed GSC-based beamformer. Several computer simulation examples show that the proposed GSC-based beamformer outperforms the existing robust techniques.

Keywords: adaptive antenna beamforming, local scattering, signal blocking, steering mismatch

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221 Optical Imaging Based Detection of Solder Paste in Printed Circuit Board Jet-Printing Inspection

Authors: D. Heinemann, S. Schramm, S. Knabner, D. Baumgarten

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Purpose: Applying solder paste to printed circuit boards (PCB) with stencils has been the method of choice over the past years. A new method uses a jet printer to deposit tiny droplets of solder paste through an ejector mechanism onto the board. This allows for more flexible PCB layouts with smaller components. Due to the viscosity of the solder paste, air blisters can be trapped in the cartridge. This can lead to missing solder joints or deviations in the applied solder volume. Therefore, a built-in and real-time inspection of the printing process is needed to minimize uncertainties and increase the efficiency of the process by immediate correction. The objective of the current study is the design of an optimal imaging system and the development of an automatic algorithm for the detection of applied solder joints from optical from the captured images. Methods: In a first approach, a camera module connected to a microcomputer and LED strips are employed to capture images of the printed circuit board under four different illuminations (white, red, green and blue). Subsequently, an improved system including a ring light, an objective lens, and a monochromatic camera was set up to acquire higher quality images. The obtained images can be divided into three main components: the PCB itself (i.e., the background), the reflections induced by unsoldered positions or screw holes and the solder joints. Non-uniform illumination is corrected by estimating the background using a morphological opening and subtraction from the input image. Image sharpening is applied in order to prevent error pixels in the subsequent segmentation. The intensity thresholds which divide the main components are obtained from the multimodal histogram using three probability density functions. Determining the intersections delivers proper thresholds for the segmentation. Remaining edge gradients produces small error areas which are removed by another morphological opening. For quantitative analysis of the segmentation results, the dice coefficient is used. Results: The obtained PCB images show a significant gradient in all RGB channels, resulting from ambient light. Using different lightings and color channels 12 images of a single PCB are available. A visual inspection and the investigation of 27 specific points show the best differentiation between those points using a red lighting and a green color channel. Estimating two thresholds from analyzing the multimodal histogram of the corrected images and using them for segmentation precisely extracts the solder joints. The comparison of the results to manually segmented images yield high sensitivity and specificity values. Analyzing the overall result delivers a Dice coefficient of 0.89 which varies for single object segmentations between 0.96 for a good segmented solder joints and 0.25 for single negative outliers. Conclusion: Our results demonstrate that the presented optical imaging system and the developed algorithm can robustly detect solder joints on printed circuit boards. Future work will comprise a modified lighting system which allows for more precise segmentation results using structure analysis.

Keywords: printed circuit board jet-printing, inspection, segmentation, solder paste detection

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220 Rural Tourism in Indian Himalayan Region: A Scope for Sustainable Livelihood

Authors: Rommila Chandra, Harshika Choudhary

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The present-day tourism sector is globally developing at a fast pace, searching for new ideas and new venues. In the Indian Himalayan Region (IHR), tourism has experienced a vast growth and continuous diversification over the last few years, thus becoming one of the fastest-growing economic sectors in India. With its majestic landscape, high peaks, rich floral and faunal diversity, and cultural history, the IHR has continuously attracted tourists and pilgrims from across the globe. The IHR has attracted a vast range of visitors who seek adventure sports, natural and spiritual solace, peace, cultural assets, food, and festivals, etc. Thus, the multi-functionality of the region has turned tourism into a key component of economic growth for the rural communities in the hills. For the local mountain people, it means valuable economic opportunity for income generation, and for the government and entrepreneurs, it brings profits. As the urban cities gain attention and investment in India, efforts have to be made to protect, safeguard, and strengthen the cultural, spiritual, and natural heritage of IHR for sustainable livelihood development. Furthermore, the socio-economic and environmental insecurities, along with geographical isolation, adds to the challenging survival in the tough terrains of IHR, creating a major threat of outmigration, land abandonment, and degradation. The question the paper intends to answer is: whether the rural community of IHR is aware of the new global trends in rural tourism and the extent of their willingness to adapt to the evolving tourism industry, which impacts the rural economy, including sustainable livelihood opportunity. The objective of the paper is to discuss the integrated nature of rural tourism, which widely depends upon natural resources, cultural heritage, agriculture/horticulture, infrastructural development, education, social awareness, and willingness of the locals. The sustainable management of all these different rural activities can lead to long-term livelihood development and social upliftment. It highlights some gap areas and recommends fewcommunity-based coping measures which the local people can adopt amidst the disorganized sector of rural tourism. Lastly, the main contribution is the exploratory research of the rural tourism vulnerability in the IHR, which would further help in studying the resilience of the tourism sector in the rural parts of a developing nation.

Keywords: community-based approach, sustainable livelihood development, Indian Himalayan region, rural tourism

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219 Retrospective Cartography of Tbilisi and Surrounding Area

Authors: Dali Nikolaishvili, Nino Khareba, Mariam Tsitsagi

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Tbilisi has been a capital of Georgia since the 5ᵗʰ century. City area was covered by forest in historical past. Nowadays the situation has been changing dramatically. Dozens of problems are caused by damages/destruction of green cover and solution, at one glance, seems to be uncomplicated (planting trees and creating green quarters), but on the other hand, according to the increasing tendency, the built up of areas still remains unsolved. Finding out the ways to overcome such obstacles is important even for protecting the health of society. Making of Retrospective cartography of the forest area of Tbilisi with use of GIS technology and remote sensing was the main aim of the research. Research about the dynamic of forest-cover in Tbilisi and its surroundings included the following steps: assessment of the dynamic of forest in Tbilisi and its surroundings. The survey was mainly based on the retrospective mapping method. Using of GIS technology, studying, comparing and identifying the narrative sources was the next step. And the last one was analyzed of the changes from the 80s to the present days on the basis of decryption of remotely sensed images. After creating a unified cartographic basis, the mapping and plans of different periods have been linked to this geodatabase. Data about green parks, individual old plants existing in the private yards and respondents' Information (according to a questionnaire created in advance) was added to the basic database, the general plan of Tbilisi and Scientific works as well. On the basis of analysis of historic, including cartographic sources, forest-cover maps for different periods of time were made. In addition, was made the catalog of individual green parks (location, area, typical composition, name and so on), which was the basis of creating several thematic maps. Areas with a high rate of green area degradation were identified. Several maps depicting the dynamics of forest cover of Tbilisi were created and analyzed. The methods of linking the data of the old cartographic sources to the modern basis were developed too, the result of which may be used in Urban Planning of Tbilisi. Understanding, perceiving and analyzing the real condition of green cover in Tbilisi and its problems, in turn, will help to take appropriate measures for the maintenance of ancient plants, to develop forests and to plan properly parks, squares, and recreational sites. Because the healthy environment is the main condition of human health and implies to the rational development of the city.

Keywords: catalogue of green area, GIS, historical cartography, cartography, remote sensing, Tbilisi

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218 Use of Geoinformatics and Mathematical Equations to Assess Erosion and Soil Fertility in Cassava Growing Areas in Maha Sarakham Province, Thailand

Authors: Sasirin Srisomkiew, Sireewan Ratsadornasai, Tanomkwan Tipvong, Isariya Meesing

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Cassava is an important food source in the tropics and has recently gained attention as a potential source of biofuel that can replace limited fossil fuel sources. As a result, the demand for cassava production to support industries both within the country and abroad has increased. In Thailand, most farmers prefer to grow cassava in sandy and sandy loam areas where the soil has low natural fertility. Cassava is a tuber plant that has large roots to store food, resulting in the absorption of large amounts of nutrients from the soil, such as nitrogen, phosphorus, and potassium. Therefore, planting cassava in the same area for a long period causes soil erosion and decreases soil fertility. The loss of soil fertility affects the economy, society, and food and energy security of the country. Therefore, it is necessary to know the level of soil fertility and the amount of nutrients in the soil. To address this problem, this study applies geo-informatics technology and mathematical equations to assess erosion and soil fertility and to analyze factors affecting the amount of cassava production in Maha Sarakham Province. The results show that the area for cassava cultivation has increased in every district of Maha Sarakham Province between 2015-2022, with the total area increasing to 180,922 rai or 5.47% of the province’s total area during this period. Furthermore, it was found that it is possible to assess areas with soil erosion problems that had a moderate level of erosion in areas with high erosion rates ranging from 5-15 T/rai/year. Soil fertility assessment and information obtained from the soil nutrient map for 2015–2023 reveal that farmers in the area have improved the soil by adding chemical fertilizers along with organic fertilizers, such as manure and green manure, to increase the amount of nutrients in the soil. This is because the soil resources of Maha Sarakham Province mostly have relatively low agricultural potential due to the soil texture being sand and sandy loam. In this scenario, the ability to absorb nutrients is low, and the soil holds little water, so it is naturally low in fertility. Moreover, agricultural soil problems were found, including the presence of saline soil, sandy soil, and acidic soil, which is a serious restriction on land use because it affects the release of nutrients into the soil. The results of this study may be used as a guideline for managing soil resources and improving soil quality to prevent soil degradation problems that may occur in the future.

Keywords: Cassava, geoinformatics, soil erosion, soil fertility, land use change

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217 Social Mentoring: Towards Formal and Informal Deployment in the Structures of the Social and Solidarity Economy

Authors: Vanessa Casadella, Mourad Chouki, Agnès Ceccarelli, Sofiane Tahi

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Mentoring is positioned in an interpersonal and intergenerational perspective, serving the transmission of interpersonal skills and organizational culture. It echoes orientation, project, self-actualization, guidance, transmission, and filiation. It is available using a formal or informal approach. The formal dimension refers to a privileged relationship between a senior and a junior. Informal mentoring is unplanned and emerges naturally between two people who choose each other. However, it remains more difficult to understand. To study the link between formal and informal mentoring and to define the notion of “social” mentoring, we conducted a qualitative study of an exploratory nature with around ten SSE organizations located in the southeast region of Tunisia. The wealth of this territory has pushed residents to found SSE organizations with a view to creating jobs but also to preserving traditions and preserving nature. These organizations developed spontaneously to solve various local problems, such as the revitalization of deserted rural areas, environmental degradation, and the reskilling and professional reintegration of people marginalized in the labor market. This research, based on semi-structured interviews in order to obtain exhaustive and sensitive data, involves an interview guide with few questions mobilized to let the respondents, leaders of the different structures, express themselves freely. The guide includes questions on activities, methods of sharing knowledge, and difficulties in understanding between stakeholders. The interviews, lasting 30 to 60 minutes, were recorded using a dictaphone and then transcribed in full. The results are as follows: 1. We see two iterative mentoring loops. A first loop can be considered a type of formal mentoring. It highlights the support organized (in the form of training) by social enterprises with the aim of developing the autonomy, know-how, and interpersonal skills of members. A second loop concerns informal mentoring. This is non-formalized support provided by members or with other members of the entourage. This informal mentoring is mainly based on the observation of good practices and learning by doing. 2. We notice an intersection between the two loops. If the first loop is not done, the second will not take place. The knowledge acquired in the first loop is used to feed the second. 3. We note a form of reluctance on the part of some members to share their knowledge for reasons of competition. Ultimately, we retain the notion of “social” mentoring as a hybridization of formal and informal mentoring while dimensioning the “social” perspective by emphasizing the reciprocal character, solidarity, confidence, and trust between the mentor and the mentee.

Keywords: social innovation, social mentoring, social and solidarity economy, informal mentoring

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216 Impact of Natural and Artificial Disasters, Lackadaisical and Semantic Approach in Risk Management, and Mitigation Implication for Sustainable Goals in Nigeria, from 2009 to 2022

Authors: Wisdom Robert Duruji, Moses Kanayochukwu Ifoh, Efeoghene Edward Esiemunobo

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This study examines the impact of natural and artificial disasters, lackadaisical and semantic approach in risk management, and mitigation implication for sustainable development goals in Nigeria, from 2009 to 2022. The study utilizes a range of research methods to achieve its objectives. These include literature review, website knowledge, Google search, news media information, academic journals, field-work and on-site observations. These diverse methods allow for a comprehensive analysis on the impact and the implications being study. The study finds that paradigm shift from remediating seismic, flooding, environmental pollution and degradation natural disasters by Nigeria Emergency Management Agency (NEMA), to political and charity organization; has plunged risk reduction strategies to embezzling opportunities. However, this lackadaisical and semantic approach in natural disaster mitigation, invariably replicates artificial disasters in Nigeria through: Boko Haram terrorist organization, Fulani herdsmen and farmers conflicts, political violence, kidnapping for ransom, ethnic conflicts, Religious dichotomy, insurgency, secession protagonists, unknown-gun-men, and banditry. This study also, finds that some Africans still engage in self-imposed slavery through human trafficking, by nefariously stow-away to Europe; through Libya, Sahara desert and Mediterranean sea; in search for job opportunities, due to ineptitude in governance by their leaders; a perilous journey that enhanced artificial disasters in Nigeria. That artificial disaster fatality in Nigeria increased from about 5,655 in 2009 to 114,318 in 2018; and to 157,643 in 2022. However, financial and material loss of about $9.29 billion was incurred in Nigeria due to natural disaster, while about $70.59 billion was accrued due to artificial disaster; from 2009 to 2018. Although disaster risk mitigation and politics can synergistically support sustainable development goals; however, they are different entities, and need for distinct separations in Nigeria, as in reality and perception. This study concluded that referendum should be conducted in Nigeria, to ascertain its current status as a nation. Therefore it is recommended that Nigerian governments should refine its naturally endowed crude oil locally; to end fuel subsidy scam, corruption and poverty in Nigeria!

Keywords: corruption, crude oil, environmental risk analysis, Nigeria, referendum, terrorism

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215 Opportunities Forensics Biology in the Study of Sperm Traces after Washing

Authors: Saule Musabekova

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Achievements of modern science, especially genetics, led to a sharp intensification of the process of proof. Footprints, subjected to destruction-related cause-effect relationships, are sources of evidentiary information on the circumstances it was committed and the persons committed it. Currently, with the overall growth in the number of crimes against sexual inviolability or sexual freedom, and increased the proportion of the crimes where to destroy the traces of the crime perpetrators different detergents are used. A characteristic feature of modern synthetic detergents is the presence of biological additives - enzymes that break down and gradually destroy stains of protein origin. To study the nature of the influence of modern washing powders semen stains were put kinds of fabrics and prepared in advance stained sperm of men of different groups according to ABO system. For research washing machines of known manufacturers of household appliances have been used with different production characteristics, in which the test was performed and the washing of various kinds of fabrics with semen stains. After washing the tissue with spots were tested for the presence of semen stains visually preserved, establishing in them surviving sperm or their elements, we studied the possibilities of the group diagnostics on the system ABO or molecular-genetic identification. The subsequent study of these spots by morphological method showed that 100% detection of morphological sperm cells - sperm is not possible. As a result, in 30% of further studies of these traces gave weakly positive results are obtained with an immunoassay test PSA SEMIQUANT. It is noted that the percentage of positive results obtained in the study of semen traces disposed on natural fiber fabrics is higher than sperm traces disposed on synthetic fabrics. Study traces of semen, confirmed by PSA - test 3% possible to establish a genetic profile of the person and obtain any positive findings of the molecular genetic examination. In other cases, it was not a sufficient amount of material for DNA identification. Results of research and the practical expert study found, in most cases, the conclusions of the identification of sperm traces do not seem possible. This a consequence of exposure to semen traces on the material evidence of biological additives contained in modern detergents and further the influence of other effective methods. Resulting in DNA has undergone irreversible changes (degradation) under the influence of external human factors. Using molecular genetic methods can partially solve the problems arising in the study of unlaundered physical evidence for the disclosure and investigation of crimes.

Keywords: study of sperm, modern detergents, washing powders, forensic medicine

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214 Environmental Interactions in Riparian Vegetation Cover in an Urban Stream Corridor: A Case Study of Duzce Asar Suyu

Authors: Engin Eroğlu, Oktay Yıldız, Necmi Aksoy, Akif Keten, Mehmet Kıvanç Ak, Şeref Keskin, Elif Atmaca, Sertaç Kaya

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Nowadays, green spaces in urban areas are under threat and decreasing their percentages in the urban areas because of increasing population, urbanization, migration, and some cultural changes in quality. An important element of the natural landscape water and water-related natural ecosystems are exposed to corruption due to these pressures. A landscape has owned many different types of elements or units, a more dominant structure than other landscapes as good or bad perceptible extent different direction and variable reveals a unique structure and character of the landscape. Whereas landscapes deal with two main groups as urban and rural according to their location on the world, especially intersection areas of urban and rural named semi-urban or semi-rural present variety landscape features. The main components of the landscape are defined as patch-matrix-corridor. The corridors include quite various vegetation types such as riparian, wetland and the others. In urban areas, natural water corridors are an important elements of the diversity of the riparian vegetation cover. In particular, water corridors attract attention with a natural diversity and lack of fragmentation, degradation and artificial results. Thanks to these features, without a doubt, water corridors are the important component of all cities in the world. These corridors not only divide the city into two separate sides, but also assured the ecological connectivity between the two sides of the city. The main objective of this study is to determine the vegetation and habitat features of urban stream corridor according to environmental interactions. Within this context, this study will be realized that 'Asar Suyu' is an important component of the city of Düzce. Moreover, the riparian zone touched contiguous area borders of the city and overlaid the urban development limits of the city, determining of characteristics of the corridor will be carried out as floristic and habitat analysis. Consequently, vegetation structure and habitat features which play an important role between riparian zone vegetation covers and environmental interaction will be determined. This study includes first results of The Scientific and Technological Research Council of Turkey (TUBITAK-116O596; 'Determining of Landscape Character of Urban Water Corridors as Visual and Ecological; A Case Study of Asar Suyu in Duzce').

Keywords: corridor, Duzce, landscape ecology, riparian vegetation

Procedia PDF Downloads 337
213 Application of Thermoplastic Microbioreactor to the Single Cell Study of Budding Yeast to Decipher the Effect of 5-Hydroxymethylfurfural on Growth

Authors: Elif Gencturk, Ekin Yurdakul, Ahmet Y. Celik, Senol Mutlu, Kutlu O. Ulgen

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Yeast cells are generally used as a model system of eukaryotes due to their complex genetic structure, rapid growth ability in optimum conditions, easy replication and well-defined genetic system properties. Thus, yeast cells increased the knowledge of the principal pathways in humans. During fermentation, carbohydrates (hexoses and pentoses) degrade into some toxic by-products such as 5-hydroxymethylfurfural (5-HMF or HMF) and furfural. HMF influences the ethanol yield, and ethanol productivity; it interferes with microbial growth and is considered as a potent inhibitor of bioethanol production. In this study, yeast single cell behavior under HMF application was monitored by using a continuous flow single phase microfluidic platform. Microfluidic device in operation is fabricated by hot embossing and thermo-compression techniques from cyclo-olefin polymer (COP). COP is biocompatible, transparent and rigid material and it is suitable for observing fluorescence of cells considering its low auto-fluorescence characteristic. The response of yeast cells was recorded through Red Fluorescent Protein (RFP) tagged Nop56 gene product, which is an essential evolutionary-conserved nucleolar protein, and also a member of the box C/D snoRNP complexes. With the application of HMF, yeast cell proliferation continued but HMF slowed down the cell growth, and after HMF treatment the cell proliferation stopped. By the addition of fresh nutrient medium, the yeast cells recovered after 6 hours of HMF exposure. Thus, HMF application suppresses normal functioning of cell cycle but it does not cause cells to die. The monitoring of Nop56 expression phases of the individual cells shed light on the protein and ribosome synthesis cycles along with their link to growth. Further computational study revealed that the mechanisms underlying the inhibitory or inductive effects of HMF on growth are enriched in functional categories of protein degradation, protein processing, DNA repair and multidrug resistance. The present microfluidic device can successfully be used for studying the effects of inhibitory agents on growth by single cell tracking, thus capturing cell to cell variations. By metabolic engineering techniques, engineered strains can be developed, and the metabolic network of the microorganism can thus be manipulated such that chemical overproduction of target metabolite is achieved along with the maximum growth/biomass yield.  

Keywords: COP, HMF, ribosome biogenesis, thermoplastic microbioreactor, yeast

Procedia PDF Downloads 171
212 Fair Federated Learning in Wireless Communications

Authors: Shayan Mohajer Hamidi

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Federated Learning (FL) has emerged as a promising paradigm for training machine learning models on distributed data without the need for centralized data aggregation. In the realm of wireless communications, FL has the potential to leverage the vast amounts of data generated by wireless devices to improve model performance and enable intelligent applications. However, the fairness aspect of FL in wireless communications remains largely unexplored. This abstract presents an idea for fair federated learning in wireless communications, addressing the challenges of imbalanced data distribution, privacy preservation, and resource allocation. Firstly, the proposed approach aims to tackle the issue of imbalanced data distribution in wireless networks. In typical FL scenarios, the distribution of data across wireless devices can be highly skewed, resulting in unfair model updates. To address this, we propose a weighted aggregation strategy that assigns higher importance to devices with fewer samples during the aggregation process. By incorporating fairness-aware weighting mechanisms, the proposed approach ensures that each participating device's contribution is proportional to its data distribution, thereby mitigating the impact of data imbalance on model performance. Secondly, privacy preservation is a critical concern in federated learning, especially in wireless communications where sensitive user data is involved. The proposed approach incorporates privacy-enhancing techniques, such as differential privacy, to protect user privacy during the model training process. By adding carefully calibrated noise to the gradient updates, the proposed approach ensures that the privacy of individual devices is preserved without compromising the overall model accuracy. Moreover, the approach considers the heterogeneity of devices in terms of computational capabilities and energy constraints, allowing devices to adaptively adjust the level of privacy preservation to strike a balance between privacy and utility. Thirdly, efficient resource allocation is crucial for federated learning in wireless communications, as devices operate under limited bandwidth, energy, and computational resources. The proposed approach leverages optimization techniques to allocate resources effectively among the participating devices, considering factors such as data quality, network conditions, and device capabilities. By intelligently distributing the computational load, communication bandwidth, and energy consumption, the proposed approach minimizes resource wastage and ensures a fair and efficient FL process in wireless networks. To evaluate the performance of the proposed fair federated learning approach, extensive simulations and experiments will be conducted. The experiments will involve a diverse set of wireless devices, ranging from smartphones to Internet of Things (IoT) devices, operating in various scenarios with different data distributions and network conditions. The evaluation metrics will include model accuracy, fairness measures, privacy preservation, and resource utilization. The expected outcomes of this research include improved model performance, fair allocation of resources, enhanced privacy preservation, and a better understanding of the challenges and solutions for fair federated learning in wireless communications. The proposed approach has the potential to revolutionize wireless communication systems by enabling intelligent applications while addressing fairness concerns and preserving user privacy.

Keywords: federated learning, wireless communications, fairness, imbalanced data, privacy preservation, resource allocation, differential privacy, optimization

Procedia PDF Downloads 75
211 Gas-Phase Noncovalent Functionalization of Pristine Single-Walled Carbon Nanotubes with 3D Metal(II) Phthalocyanines

Authors: Vladimir A. Basiuk, Laura J. Flores-Sanchez, Victor Meza-Laguna, Jose O. Flores-Flores, Lauro Bucio-Galindo, Elena V. Basiuk

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Noncovalent nanohybrid materials combining carbon nanotubes (CNTs) with phthalocyanines (Pcs) is a subject of increasing research effort, with a particular emphasis on the design of new heterogeneous catalysts, efficient organic photovoltaic cells, lithium batteries, gas sensors, field effect transistors, among other possible applications. The possibility of using unsubstituted Pcs for CNT functionalization is very attractive due to their very moderate cost and easy commercial availability. However, unfortunately, the deposition of unsubstituted Pcs onto nanotube sidewalls through the traditional liquid-phase protocols turns to be very problematic due to extremely poor solubility of Pcs. On the other hand, unsubstituted free-base H₂Pc phthalocyanine ligand, as well as many of its transition metal complexes, exhibit very high thermal stability and considerable volatility under reduced pressure, which opens the possibility for their physical vapor deposition onto solid surfaces, including nanotube sidewalls. In the present work, we show the possibility of simple, fast and efficient noncovalent functionalization of single-walled carbon nanotubes (SWNTs) with a series of 3d metal(II) phthalocyanines Me(II)Pc, where Me= Co, Ni, Cu, and Zn. The functionalization can be performed in a temperature range of 400-500 °C under moderate vacuum and requires about 2-3 h only. The functionalized materials obtained were characterized by means of Fourier-transform infrared (FTIR), Raman, UV-visible and energy-dispersive X-ray spectroscopy (EDS), scanning and transmission electron microscopy (SEM and TEM, respectively) and thermogravimetric analysis (TGA). TGA suggested that Me(II)Pc weight content is 30%, 17% and 35% for NiPc, CuPc, and ZnPc, respectively (CoPc exhibited anomalous thermal decomposition behavior). The above values are consistent with those estimated from EDS spectra, namely, of 24-39%, 27-36% and 27-44% for CoPc, CuPc, and ZnPc, respectively. A strong increase in intensity of D band in the Raman spectra of SWNT‒Me(II)Pc hybrids, as compared to that of pristine nanotubes, implies very strong interactions between Pc molecules and SWNT sidewalls. Very high absolute values of binding energies of 32.46-37.12 kcal/mol and the highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO, respectively) distribution patterns, calculated with density functional theory by using Perdew-Burke-Ernzerhof general gradient approximation correlation functional in combination with the Grimme’s empirical dispersion correction (PBE-D) and the double numerical basis set (DNP), also suggested that the interactions between Me(II) phthalocyanines and nanotube sidewalls are very strong. The authors thank the National Autonomous University of Mexico (grant DGAPA-IN200516) and the National Council of Science and Technology of Mexico (CONACYT, grant 250655) for financial support. The authors are also grateful to Dr. Natalia Alzate-Carvajal (CCADET of UNAM), Eréndira Martínez (IF of UNAM) and Iván Puente-Lee (Faculty of Chemistry of UNAM) for technical assistance with FTIR, TGA measurements, and TEM imaging, respectively.

Keywords: carbon nanotubes, functionalization, gas-phase, metal(II) phthalocyanines

Procedia PDF Downloads 130
210 Bioaccessible Phenolics, Phenolic Bioaccessibility and Antioxidant Activity of Pumpkin Flour

Authors: Emine Aydin, Duygu Gocmen

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Pumpkin flour (PF) has a long shelf life and can be used as a nutritive, functional (antioxidant properties, phenolic contents, etc.) and coloring agent in many food items, especially in bakery products, sausages, instant noodles, pasta and flour mixes. Pre-treatment before drying is one of the most important factors affecting the quality of a final powdered product. Pretreatment, such as soaking in a bisulfite solution, provides that total carotenoids in raw materials rich in carotenoids, especially pumpkins, are retained in the dried product. This is due to the beneficial effect of antioxidant additives in the protection of carotenoids in the dehydrated plant foods. The oxygen present in the medium is removed by the radical SO₂, and thus the carotene degradation caused by the molecular oxygen is inhibited by the presence of SO₂. In this study, pumpkin flours (PFs) produced by two different applications (with or without metabisulfite pre-treatment) and then dried in a freeze dryer. The phenolic contents and antioxidant activities of pumpkin flour were determined. In addition to this, the compound of bioavailable phenolic substances which is obtained by PF has also been investigated using in vitro methods. As a result of researches made in recent years, it has been determined that all nutrients taken with foodstuffs are not bioavailable. Bioavailability changes depending on physical properties, chemical compounds, and capacities of individual digestion of foods. Therefore in this study; bioaccessible phenolics and phenolic bioaccessibility were also determined. The phenolics of the samples with metabisulfite application were higher than those of the samples without metabisulfite pre-treatment. Soaking in metabisulfite solution might have a protective effect for phenolic compounds. Phenolics bioaccessibility of pumpkin flours was investigated in order to assess pumpkin flour as sources of accessible phenolics. The higher bioaccessible phenolics (384.19 mg of GAE 100g⁻¹ DW) and phenolic bioaccessibility values (33.65 mL 100 mL⁻¹) were observed in the pumpkin flour with metabisulfite pre-treatment. Metabisulfite application caused an increase in bioaccessible phenolics of pumpkin flour. According to all assay (ABTS, CUPRAC, DPPH, and FRAP) results, both free and bound phenolics of pumpkin flour with metabisulfite pre-treatment had higher antioxidant activity than those of the sample without metabisulfite pre-treatment. The samples subjected to MS pre-treatment exhibited higher antioxidant activities than those of the samples without MS pre-treatment, this possibly due to higher phenolic contents of the samples with metabisulfite applications. As a result, metabisulfite application caused an increase in phenolic contents, bioaccessible phenolics, phenolic bioaccessibility and antioxidant activities of pumpkin flour. It can be said that pumpkin flour can be used as an alternative functional and nutritional ingredient in bakery products, dairy products (yoghurt, ice-cream), soups, sauces, infant formulae, confectionery, etc.

Keywords: pumpkin flour, bioaccessible phenolics, phenolic bioaccessibility, antioxidant activity

Procedia PDF Downloads 325
209 On the Utility of Bidirectional Transformers in Gene Expression-Based Classification

Authors: Babak Forouraghi

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A genetic circuit is a collection of interacting genes and proteins that enable individual cells to implement and perform vital biological functions such as cell division, growth, death, and signaling. In cell engineering, synthetic gene circuits are engineered networks of genes specifically designed to implement functionalities that are not evolved by nature. These engineered networks enable scientists to tackle complex problems such as engineering cells to produce therapeutics within the patient's body, altering T cells to target cancer-related antigens for treatment, improving antibody production using engineered cells, tissue engineering, and production of genetically modified plants and livestock. Construction of computational models to realize genetic circuits is an especially challenging task since it requires the discovery of the flow of genetic information in complex biological systems. Building synthetic biological models is also a time-consuming process with relatively low prediction accuracy for highly complex genetic circuits. The primary goal of this study was to investigate the utility of a pre-trained bidirectional encoder transformer that can accurately predict gene expressions in genetic circuit designs. The main reason behind using transformers is their innate ability (attention mechanism) to take account of the semantic context present in long DNA chains that are heavily dependent on the spatial representation of their constituent genes. Previous approaches to gene circuit design, such as CNN and RNN architectures, are unable to capture semantic dependencies in long contexts, as required in most real-world applications of synthetic biology. For instance, RNN models (LSTM, GRU), although able to learn long-term dependencies, greatly suffer from vanishing gradient and low-efficiency problem when they sequentially process past states and compresses contextual information into a bottleneck with long input sequences. In other words, these architectures are not equipped with the necessary attention mechanisms to follow a long chain of genes with thousands of tokens. To address the above-mentioned limitations, a transformer model was built in this work as a variation to the existing DNA Bidirectional Encoder Representations from Transformers (DNABERT) model. It is shown that the proposed transformer is capable of capturing contextual information from long input sequences with an attention mechanism. In previous works on genetic circuit design, the traditional approaches to classification and regression, such as Random Forrest, Support Vector Machine, and Artificial Neural Networks, were able to achieve reasonably high R2 accuracy levels of 0.95 to 0.97. However, the transformer model utilized in this work, with its attention-based mechanism, was able to achieve a perfect accuracy level of 100%. Further, it is demonstrated that the efficiency of the transformer-based gene expression classifier is not dependent on the presence of large amounts of training examples, which may be difficult to compile in many real-world gene circuit designs.

Keywords: machine learning, classification and regression, gene circuit design, bidirectional transformers

Procedia PDF Downloads 61
208 Multidisciplinary Approach to Mio-Plio-Quaternary Aquifer Study in the Zarzis Region (Southeastern Tunisia)

Authors: Ghada Ben Brahim, Aicha El Rabia, Mohamed Hedi Inoubli

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Climate change has exacerbated disparities in the distribution of water resources in Tunisia, resulting in significant degradation in quantity and quality over the past five decades. The Mio-Plio-Quaternary aquifer, the primary water source in the Zarzis region, is subject to climatic, geographical, and geological challenges, as well as human stress. The region is experiencing uneven distribution and growing threats from groundwater salinity and saltwater intrusion. Addressing this challenge is critical for the arid region’s socioeconomic development, and effective water resource management is required to combat climate change and reduce water deficits. This study uses a multidisciplinary approach to determine the groundwater potential of this aquifer, involving geophysics and hydrogeology data analysis. We used advanced techniques such as 3D Euler deconvolution and power spectrum analysis to generate detailed anomaly maps and estimate the depths of density sources, identifying significant Bouguer anomalies trending E-W, NW-SE, and NE-SW. Various techniques, such as wavelength filtering, upward continuation, and horizontal and vertical derivatives, were used to improve the gravity data, resulting in consistent results for anomaly shapes and amplitudes. The Euler deconvolution method revealed two prominent surface faults, trending NE-SW and NW-SE, that have a significant impact on the distribution of sedimentary facies and water quality within the Mio-Plio-Quaternary aquifer. Additionally, depth maxima greater than 1400 m to the North indicate the presence of a Cretaceous paleo-fault. Geoelectrical models and resistivity pseudo-sections were used to interpret the distribution of electrical facies in the Mio-Plio-Quaternary aquifer, highlighting lateral variation and depositional environment type. AI optimises the analysis and interpretation of exploration data, which is important to long-term management and water security. Machine learning algorithms and deep learning models analyse large datasets to provide precise interpretations of subsurface conditions, such as aquifer salinisation. However, AI has limitations, such as the requirement for large datasets, the risk of overfitting, and integration issues with traditional geological methods.

Keywords: mio-plio-quaternary aquifer, Southeastern Tunisia, geophysical methods, hydrogeological analysis, artificial intelligence

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207 Understanding the Reasons for Flooding in Chennai and Strategies for Making It Flood Resilient

Authors: Nivedhitha Venkatakrishnan

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Flooding in urban areas in India has become a usual ritual phenomenon and a nightmare to most cities, which is a consequence of man-made disruption resulting in disaster. The City planning in India falls short of withstanding hydro generated disasters. This has become a barrier and challenge in the process of development put forth by urbanization, high population density, expanding informal settlements, environment degradation from uncollected and untreated waste that flows into natural drains and water bodies, this has disrupted the natural mechanism of hazard protection such as drainage channels, wetlands and floodplains. The magnitude and the impact of the mishap was high because of the failure of development policies, strategies, plans that the city had adopted. In the current scenario, cities are becoming the home for future, with economic diversification bringing in more investment into cities especially in domains of Urban infrastructure, planning and design. The uncertainty of the Urban futures in these low elevated coastal zones faces an unprecedented risk and threat. The study on focuses on three major pillars of resilience such as Recover, Resist and Restore. This process of getting ready to handle the situation bridges the gap between disaster response management and risk reduction requires a shift in paradigm. The study involved a qualitative research and a system design approach (framework). The initial stages involved mapping out of the urban water morphology with respect to the spatial growth gave an insight of the water bodies that have gone missing over the years during the process of urbanization. The major finding of the study was missing links between traditional water harvesting network was a major reason resulting in a manmade disaster. The research conceptualized the ideology of a sponge city framework which would guide the growth through institutional frameworks at different levels. The next stage was on understanding the implementation process at various stage to ensure the shift in paradigm. Demonstration of the concepts at a neighborhood level where, how, what are the functions and benefits of each component. Quantifying the design decision with rainwater harvest, surface runoff and how much water is collected and how it could be collected, stored and reused. The study came with further recommendation for Water Mitigation Spaces that will revive the traditional harvesting network.

Keywords: flooding, man made disaster, resilient city, traditional harvesting network, waterbodies

Procedia PDF Downloads 140
206 Evaluation of Antarctic Bacteria as Potential Producers of Cellulolytic Enzymes of Industrial Interest

Authors: Claudio Lamilla, Andrés Santos, Vicente Llanquinao, Jocelyn Hermosilla, Leticia Barrientos

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The industry in general is very interested in improving and optimizing industrial processes in order to reduce the costs involved in obtaining raw materials and production. Thus, an interesting and cost-effective alternative is the incorporation of bioactive metabolites in such processes, being an example of this enzymes which catalyze efficiently a large number of enzymatic reactions of industrial and biotechnological interest. In the search for new sources of these active metabolites, Antarctica is one of the least explored places on our planet where the most drastic cold conditions, salinity, UVA-UVB and liquid water available are present, features that have shaped all life in this very harsh environment, especially bacteria that live in different Antarctic ecosystems, which have had to develop different strategies to adapt to these conditions, producing unique biochemical strategies. In this work the production of cellulolytic enzymes of seven bacterial strains isolated from marine sediments at different sites in the Antarctic was evaluated. Isolation of the strains was performed using serial dilutions in the culture medium at M115°C. The identification of the strains was performed using universal primers (27F and 1492R). The enzyme activity assays were performed on R2A medium, carboxy methyl cellulose (CMC)was added as substrate. Degradation of the substrate was revealed by adding Lugol. The results show that four of the tested strains produce enzymes which degrade CMC substrate. The molecular identifications, showed that these bacteria belong to the genus Streptomyces and Pseudoalteromonas, being Streptomyces strain who showed the highest activity. Only some bacteria in marine sediments have the ability to produce these enzymes, perhaps due to their greater adaptability to degrade at temperatures bordering zero degrees Celsius, some algae that are abundant in this environment and have cellulose as the main structure. The discovery of new enzymes adapted to cold is of great industrial interest, especially for paper, textiles, detergents, biofuels, food and agriculture. These enzymes represent 8% of industrial demand worldwide and is expected to increase their demand in the coming years. Mainly in the paper and food industry are required in extraction processes starch, protein and juices, as well as the animal feed industry where treating vegetables and grains helps improve the nutritional value of the food, all this clearly puts Antarctic microorganisms and their enzymes specifically as a potential contribution to industry and the novel biotechnological applications.

Keywords: antarctic, bacteria, biotechnological, cellulolytic enzymes

Procedia PDF Downloads 297
205 Antiulcer Potential of Heme Oxygenase-1 Inducers

Authors: Gaweł Magdalena, Lipkowska Anna, Olbert Magdalena, Frąckiewicz Ewelina, Librowski Tadeusz, Nowak Gabriel, Pilc Andrzej

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Heme oxygenase-1 (HO-1), also known as heat shock protein 32 (HSP32), has been shown to be implicated in cytoprotection in various organs. Its activation plays a significant role in acute and chronic inflammation, protecting cells from oxidative injury and apoptosis. This inducible isoform of HO catalyzes the first and rate-limiting step in heme degradation to produce equimolar quantities of biologically active products: carbon monoxide (CO), free iron and biliverdin. CO has been reported to possess anti-apoptotic properties. Moreover, it inhibits the production of proinflammatory cytokines and stimulates the synthesis of the anti-inflammatory interleukin-10 (IL-10), as well as promotes vasodilatation at sites of inflammation. The second product of catalytic HO-1 activity, free cytotoxic iron, is promptly sequestered into the iron storage protein ferritin, which lowers the pro-oxidant state of the cell. The third product, biliverdin, is subsequently converted by biliverdin reductase into the bile pigment bilirubin, the most potent endogenous antioxidant among the constituents of human serum, which modulates immune effector functions and suppresses inflammatory response. Furthermore, being one of the so-called stress proteins, HO-1 adaptively responds to different stressors, such as reactive oxygen species (ROS), inflammatory cytokines and heavy metals and thus protects cells against such conditions as ischemia, hemorrhagic shock, heat shock or hypoxia. It is suggested that pharmacologic modulation of HO-1 may represent an effective strategy for prevention of stress and drug-induced gastrointestinal toxicity. HO-1 is constitutively expressed in normal gastric, intestinal and colonic mucosa and up-regulated during inflammation. It has been proven that HO-1 up-regulated by hemin, heme and cobalt-protoporphyrin ameliorates experimental colitis. In addition, the up-regulation of HO-1 partially explains the mechanism of action of 5-aminosalicylic acid (5-ASA), which is used clinically as an anti-colitis agent. In 2009 Ueda et al. has reported for the first time that mucosal protection by Polaprezinc, a chelate compound of zinc and L-carnosine used as an anti-ulcer drug in Japan, is also attributed to induction of HO-1 in the stomach. Since then, inducers of HO-1 are desired subject of research, as they may constitute therapeutically effective anti-ulcer drugs.

Keywords: heme oxygenase-1, gastric lesions, gastroprotection, Polaprezinc

Procedia PDF Downloads 504
204 Influence of Controlled Retting on the Quality of the Hemp Fibres Harvested at the Seed Maturity by Using a Designed Lab-Scale Pilot Unit

Authors: Brahim Mazian, Anne Bergeret, Jean-Charles Benezet, Sandrine Bayle, Luc Malhautier

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Hemp fibers are increasingly used as reinforcements in polymer matrix composites due to their competitive performance (low density, mechanical properties and biodegradability) compared to conventional fibres such as glass fibers. However, the huge variation of their biochemical, physical and mechanical properties limits the use of these natural fibres in structural applications when high consistency and homogeneity are required. In the hemp industry, traditional processes termed field retting are commonly used to facilitate the extraction and separation of stem fibers. This retting treatment consists to spread out the stems on the ground for a duration ranging from a few days to several weeks. Microorganisms (fungi and bacteria) grow on the stem surface and produce enzymes that degrade pectinolytic substances in the middle lamellae surrounding the fibers. This operation depends on the weather conditions and is currently carried out very empirically in the fields so that a large variability in the hemp fibers quality (mechanical properties, color, morphology, chemical composition…) is resulting. Nonetheless, if controlled, retting might be favorable for good properties of hemp fibers and then of hemp fibers reinforced composites. Therefore, the present study aims to investigate the influence of controlled retting within a designed environmental chamber (lab-scale pilot unit) on the quality of the hemp fibres harvested at the seed maturity growth stage. Various assessments were applied directly on fibers: color observations, morphological (optical microscope), surface (ESEM), biochemical (gravimetry) analysis, spectrocolorimetric measurements (pectins content), thermogravimetric analysis (TGA) and tensile testing. The results reveal that controlled retting leads to a rapid change of color from yellow to dark grey due to development of microbial communities (fungi and bacteria) at the stem surface. An increase of thermal stability of fibres due to the removal of non-cellulosic components along retting is also observed. A separation of bast fibers to elementary fibers occurred with an evolution of chemical composition (degradation of pectins) and a rapid decrease in tensile properties (380MPa to 170MPa after 3 weeks) due to accelerated retting process. The influence of controlled retting on the biocomposite material (PP / hemp fibers) properties is under investigation.

Keywords: controlled retting, hemp fibre, mechanical properties, thermal stability

Procedia PDF Downloads 155
203 Computational Analysis of Thermal Degradation in Wind Turbine Spars' Equipotential Bonding Subjected to Lightning Strikes

Authors: Antonio A. M. Laudani, Igor O. Golosnoy, Ole T. Thomsen

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Rotor blades of large, modern wind turbines are highly susceptible to downward lightning strikes, as well as to triggering upward lightning; consequently, it is necessary to equip them with an effective lightning protection system (LPS) in order to avoid any damage. The performance of existing LPSs is affected by carbon fibre reinforced polymer (CFRP) structures, which lead to lightning-induced damage in the blades, e.g. via electrical sparks. A solution to prevent internal arcing would be to electrically bond the LPS and the composite structures such that to obtain the same electric potential. Nevertheless, elevated temperatures are achieved at the joint interfaces because of high contact resistance, which melts and vaporises some of the epoxy resin matrix around the bonding. The produced high-pressure gasses open up the bonding and can ignite thermal sparks. The objective of this paper is to predict the current density distribution and the temperature field in the adhesive joint cross-section, in order to check whether the resin pyrolysis temperature is achieved and any damage is expected. The finite element method has been employed to solve both the current and heat transfer problems, which are considered weakly coupled. The mathematical model for electric current includes Maxwell-Ampere equation for induced electric field solved together with current conservation, while the thermal field is found from heat diffusion equation. In this way, the current sub-model calculates Joule heat release for a chosen bonding configuration, whereas the thermal analysis allows to determining threshold values of voltage and current density not to be exceeded in order to maintain the temperature across the joint below the pyrolysis temperature, therefore preventing the occurrence of outgassing. In addition, it provides an indication of the minimal number of bonding points. It is worth to mention that the numerical procedures presented in this study can be tailored and applied to any type of joints other than adhesive ones for wind turbine blades. For instance, they can be applied for lightning protection of aerospace bolted joints. Furthermore, they can even be customized to predict the electromagnetic response under lightning strikes of other wind turbine systems, such as nacelle and hub components.

Keywords: carbon fibre reinforced polymer, equipotential bonding, finite element method, FEM, lightning protection system, LPS, wind turbine blades

Procedia PDF Downloads 164
202 Effects of Plasma Technology in Biodegradable Films for Food Packaging

Authors: Viviane P. Romani, Bradley D. Olsen, Vilásia G. Martins

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Biodegradable films for food packaging have gained growing attention due to environmental pollution caused by synthetic films and the interest in the better use of resources from nature. Important research advances were made in the development of materials from proteins, polysaccharides, and lipids. However, the commercial use of these new generation of sustainable materials for food packaging is still limited due to their low mechanical and barrier properties that could compromise the food quality and safety. Thus, strategies to improve the performance of these materials have been tested, such as chemical modifications, incorporation of reinforcing structures and others. Cold plasma is a versatile, fast and environmentally friendly technology. It consists of a partially ionized gas containing free electrons, ions, and radicals and neutral particles able to react with polymers and start different reactions, leading to the polymer degradation, functionalization, etching and/or cross-linking. In the present study, biodegradable films from fish protein prepared through the casting technique were plasma treated using an AC glow discharge equipment. The reactor was preliminary evacuated to ~7 Pa and the films were exposed to air plasma for 2, 5 and 8 min. The films were evaluated by their mechanical and water vapor permeability (WVP) properties and changes in the protein structure were observed using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). Potential cross-links and elimination of surface defects by etching might be the reason for the increase in tensile strength and decrease in the elongation at break observed. Among the times of plasma application tested, no differences were observed when higher times of exposure were used. The X-ray pattern showed a broad peak at 2θ = 19.51º that corresponds to the distance of 4.6Å by applying the Bragg’s law. This distance corresponds to the average backbone distance within the α-helix. Thus, the changes observed in the films might indicate that the helical configuration of fish protein was disturbed by plasma treatment. SEM images showed surface damage in the films with 5 and 8 min of plasma treatment, indicating that 2 min was the most adequate time of treatment. It was verified that plasma removes water from the films once weight loss of 4.45% was registered for films treated during 2 min. However, after 24 h in 50% of relative humidity, the water lost was recovered. WVP increased from 0.53 to 0.65 g.mm/h.m².kPa after plasma treatment during 2 min, that is desired for some foods applications which require water passage through the packaging. In general, the plasma technology affects the properties and structure of fish protein films. Since this technology changes the surface of polymers, these films might be used to develop multilayer materials, as well as to incorporate active substances in the surface to obtain active packaging.

Keywords: fish protein films, food packaging, improvement of properties, plasma treatment

Procedia PDF Downloads 163
201 Effect of Pollutions on Mangrove Forests of Nayband National Marine Park

Authors: Esmaeil Kouhgardi, Elaheh Shakerdargah

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The mangrove ecosystem is a complex of various inter-related elements in the land-sea interface zone which is linked with other natural systems of the coastal region such as corals, sea-grass, coastal fisheries and beach vegetation. The mangrove ecosystem consists of water, muddy soil, trees, shrubs, and their associated flora, fauna and microbes. It is a very productive ecosystem sustaining various forms of life. Its waters are nursery grounds for fish, crustacean, and mollusk and also provide habitat for a wide range of aquatic life, while the land supports a rich and diverse flora and fauna, but pollutions may affect these characteristics. Iran has the lowest share of Persian Gulf pollution among the eight littoral states; environmental experts are still deeply concerned about the serious consequences of the pollution in the oil-rich gulf. Prolongation of critical conditions in the Persian Gulf has endangered its aquatic ecosystem. Water purification equipment, refineries, wastewater emitted by onshore installations, especially petrochemical plans, urban sewage, population density and extensive oil operations of Arab states are factors contaminating the Persian Gulf waters. Population density has been the major cause of pollution and environmental degradation in the Persian Gulf. Persian Gulf is a closed marine environment which is connected to open waterways only from one way. It usually takes between three and four years for the gulf's water to be completely replaced. Therefore, any pollution entering the water will remain there for a relatively long time. Presently, the high temperature and excessive salt level in the water have exposed the marine creatures to extra threats, which mean they have to survive very tough conditions. The natural environment of the Persian Gulf is very rich with good fish grounds, extensive coral reefs and pearl oysters in abundance, but has become increasingly under pressure due to the heavy industrialization and in particular the repeated major oil spillages associated with the various recent wars fought in the region. Pollution may cause the mortality of mangrove forests by effect on root, leaf and soil of the area. Study was showed the high correlation between industrial pollution and mangrove forests health in south of Iran and increase of population, coupled with economic growth, inevitably caused the use of mangrove lands for various purposes such as construction of roads, ports and harbors, industries and urbanization.

Keywords: Mangrove forest, pollution, Persian Gulf, population, environment

Procedia PDF Downloads 399
200 Circular Economy Initiatives in Denmark for the Recycling of Household Plastic Wastes

Authors: Rikke Lybæk

Abstract:

This paper delves into the intricacies of recycling household plastic waste within Denmark, employing an exploratory case study methodology to shed light on the technical, strategic, and market dynamics of the plastic recycling value chain. Focusing on circular economy principles, the research identifies critical gaps and opportunities in recycling processes, particularly regarding plastic packaging waste derived from households, with a notable absence in food packaging reuse initiatives. The study uncovers the predominant practice of downcycling in the current value chain, underscoring a disconnect between the potential for high-quality plastic recycling and the market's readiness to embrace such materials. Through detailed examination of three leading companies in Denmark's plastic industry, the paper highlights the existing support for recycling initiatives, yet points to the necessity of assured quality in sorted plastics to foster broader adoption. The analysis further explores the importance of reuse strategies to complement recycling efforts, aiming to alleviate the pressure on virgin feedstock. The paper ventures into future perspectives, discussing different approaches such as biological degradation methods, watermark technology for plastic traceability, and the potential for bio-based and PtX plastics. These avenues promise not only to enhance recycling efficiency but also to contribute to a more sustainable circular economy by reducing reliance on virgin materials. Despite the challenges outlined, the research demonstrates a burgeoning market for recycled plastics within Denmark, propelled by both environmental considerations and customer demand. However, the study also calls for a more harmonized and effective waste collection and sorting system to elevate the quality and quantity of recyclable plastics. By casting a spotlight on successful case studies and potential technological advancements, the paper advocates for a multifaceted approach to plastic waste management, encompassing not only recycling but also innovative reuse and reduction strategies to foster a more sustainable future. In conclusion, this study underscores the urgent need for innovative, coordinated efforts in the recycling and management of plastic waste to move towards a more sustainable and circular economy in Denmark. It calls for the adoption of comprehensive strategies that include improving recycling technologies, enhancing waste collection systems, and fostering a market environment that values recycled materials, thereby contributing significantly to environmental sustainability goals.

Keywords: case study, circular economy, Denmark, plastic waste, sustainability, waste management

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199 Investigation on Correlation of Earthquake Intensity Parameters with Seismic Response of Reinforced Concrete Structures

Authors: Semra Sirin Kiris

Abstract:

Nonlinear dynamic analysis is permitted to be used for structures without any restrictions. The important issue is the selection of the design earthquake to conduct the analyses since quite different response may be obtained using ground motion records at the same general area even resulting from the same earthquake. In seismic design codes, the method requires scaling earthquake records based on site response spectrum to a specified hazard level. Many researches have indicated that this limitation about selection can cause a large scatter in response and other charecteristics of ground motion obtained in different manner may demonstrate better correlation with peak seismic response. For this reason influence of eleven different ground motion parameters on the peak displacement of reinforced concrete systems is examined in this paper. From conducting 7020 nonlinear time history analyses for single degree of freedom systems, the most effective earthquake parameters are given for the range of the initial periods and strength ratios of the structures. In this study, a hysteresis model for reinforced concrete called Q-hyst is used not taken into account strength and stiffness degradation. The post-yielding to elastic stiffness ratio is considered as 0.15. The range of initial period, T is from 0.1s to 0.9s with 0.1s time interval and three different strength ratios for structures are used. The magnitude of 260 earthquake records selected is higher than earthquake magnitude, M=6. The earthquake parameters related to the energy content, duration or peak values of ground motion records are PGA(Peak Ground Acceleration), PGV (Peak Ground Velocity), PGD (Peak Ground Displacement), MIV (Maximum Increamental Velocity), EPA(Effective Peak Acceleration), EPV (Effective Peak Velocity), teff (Effective Duration), A95 (Arias Intensity-based Parameter), SPGA (Significant Peak Ground Acceleration), ID (Damage Factor) and Sa (Spectral Response Spectrum).Observing the correlation coefficients between the ground motion parameters and the peak displacement of structures, different earthquake parameters play role in peak displacement demand related to the ranges formed by the different periods and the strength ratio of a reinforced concrete systems. The influence of the Sa tends to decrease for the high values of strength ratio and T=0.3s-0.6s. The ID and PGD is not evaluated as a measure of earthquake effect since high correlation with displacement demand is not observed. The influence of the A95 is high for T=0.1 but low related to the higher values of T and strength ratio. The correlation of PGA, EPA and SPGA shows the highest correlation for T=0.1s but their effectiveness decreases with high T. Considering all range of structural parameters, the MIV is the most effective parameter.

Keywords: earthquake parameters, earthquake resistant design, nonlinear analysis, reinforced concrete

Procedia PDF Downloads 151
198 Impact of Microwave and Air Velocity on Drying Kinetics and Rehydration of Potato Slices

Authors: Caiyun Liu, A. Hernandez-Manas, N. Grimi, E. Vorobiev

Abstract:

Drying is one of the most used methods for food preservation, which extend shelf life of food and makes their transportation, storage and packaging easier and more economic. The commonly dried method is hot air drying. However, its disadvantages are low energy efficiency and long drying times. Because of the high temperature during the hot air drying, the undesirable changes in pigments, vitamins and flavoring agents occur which result in degradation of the quality parameters of the product. Drying process can also cause shrinkage, case hardening, dark color, browning, loss of nutrients and others. Recently, new processes were developed in order to avoid these problems. For example, the application of pulsed electric field provokes cell membrane permeabilisation, which increases the drying kinetics and moisture diffusion coefficient. Microwave drying technology has also several advantages over conventional hot air drying, such as higher drying rates and thermal efficiency, shorter drying time, significantly improved product quality and nutritional value. Rehydration kinetics of dried product is a very important characteristic of dried products. Current research has indicated that the rehydration ratio and the coefficient of rehydration are dependent on the processing conditions of drying. The present study compares the efficiency of two processes (1: room temperature air drying, 2: microwave/air drying) in terms of drying rate, product quality and rehydration ratio. In this work, potato slices (≈2.2g) with a thickness of 2 mm and diameter of 33mm were placed in the microwave chamber and dried. Drying kinetics and drying rates of different methods were determined. The process parameters included inlet air velocity (1 m/s, 1.5 m/s, 2 m/s) and microwave power (50 W, 100 W, 200 W and 250 W) were studied. The evolution of temperature during microwave drying was measured. The drying power had a strong effect on drying rate, and the microwave-air drying resulted in 93% decrease in the drying time when the air velocity was 2 m/s and the power of microwave was 250 W. Based on Lewis model, drying rate constants (kDR) were determined. It was observed an increase from kDR=0.0002 s-1 to kDR=0.0032 s-1 of air velocity of 2 m/s and microwave/air (at 2m/s and 250W) respectively. The effective moisture diffusivity was calculated by using Fick's law. The results show an increase of effective moisture diffusivity from 7.52×10-11 to 2.64×10-9 m2.s-1 for air velocity of 2 m/s and microwave/air (at 2m/s and 250W) respectively. The temperature of the potato slices increased for higher microwaves power, but decreased for higher air velocity. The rehydration ratio, defined as the weight of the the sample after rehydration per the weight of dried sample, was determined at different water temperatures (25℃, 50℃, 75℃). The rehydration ratio increased with the water temperature and reached its maximum at the following conditions: 200 W for the microwave power, 2 m/s for the air velocity and 75°C for the water temperature. The present study shows the interest of microwave drying for the food preservation.

Keywords: drying, microwave, potato, rehydration

Procedia PDF Downloads 270