Search results for: degree distance

Authors: Hacer Sule Gonul, Vedat Uyak

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Intensive use of pesticides in agricultural activity causes mixing of these compounds into water sources with surface flow. Especially after the 1970s, a number of limitations imposed on the use of chlorinated pesticides that have a carcinogenic risk potential and regulatory limit have been established. These chlorinated pesticides discharge to water resources, transport in the water and land environment and accumulation in the human body through the food chain raises serious health concerns. Carbon nanotubes (CNTs) have attracted considerable attention from on all because of their excellent mechanical, electrical, and environmental characteristics. Due to CNT particles' high degree of hydrophobic surfaces, these nanoparticles play critical role in the removal of water contaminants of natural organic matters, pesticides and phenolic compounds in water sources. Health concerns associated with chlorinated pesticides requires the removal of such contaminants from aquatic environment. Although the use of aldrin and atrazine was restricted in our country, repatriation of illegal entry and widespread use of such chemicals in agricultural areas cause increases for the concentration of these chemicals in the water supply. In this study, the compounds of chlorinated pesticides such as aldrin and atrazine compounds would be tried to eliminate from drinking water with carbon nanotube adsorption method. Within this study, 2 different types of CNT would be used including single-wall (SWCNT) and multi-wall (MWCNT) carbon nanotubes. Adsorption isotherms within the scope of work, the parameters affecting the adsorption of chlorinated pesticides in water are considered as pH, contact time, CNT type, CNT dose and initial concentration of pesticides. As a result, under conditions of neutral pH conditions with MWCNT respectively for atrazine and aldrin obtained adsorption capacity of determined as 2.24 µg/mg ve 3.84 µg/mg. On the other hand, the determined adsorption capacity rates for SWCNT for aldrin and atrazine has identified as 3.91 µg/mg ve 3.92 µg/mg. After all, each type of pesticide that provides superior performance in relieving SWCNT particles has emerged.

Keywords: pesticide, drinking water, carbon nanotube, adsorption

Procedia PDF Downloads 165

Authors: V. V. Belavadi, Syed Najeer E. Noor Khadri, Shivamurthy Naik

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Members of aculeate Hymenoptera exhibit different levels of sociality. While Chrysidoidea are primarily parasitic and use their sting only for the purpose parasitizing the host and never for defense, all vespoid and apoid (sphecid) wasps use their sting for paralysing their prey as well as for defending themselves from predators and intruders. Though most apoid bees use their sting for defending themselves, a few bees (Apis spp.) use their sting exclusively for defending their colonies and the brood. A preliminary study conducted on the comparative morphology of stings of apoid bees and wasps and that of vespid wasps, indicated that the backward projected barbs are more pronounced only in the genus Apis, which is considered as the reason why a honey bee worker, loses its sting and dies when it stings a higher animal. This raises an important question: How barbs on lancets of Apis bees evolved? Supposing the barbs had not been strong, the worker bee would have been more efficient in defending the colony instead of only once in its lifetime! Some arguments in favour of worker altruistic behaviour, mention that in highly social insects, the colony size is large, workers are closely related among themselves and a worker sacrificing its life for the colony is beneficial for the colony. However, in colonies with a queen that has mated multiple times, the coefficient of relatedness among workers gets reduced and still the workers continue to exhibit the same behaviour. In this paper, we have tried to compare the morphology of stings of aculeate Hymenoptera and have attempted to relate sting morphology with social behaviour. Species examined for sting morphology are A. cerana, Apis dorsata, A. florea, Amegilla violacea, A. zonata, Megachile anthracina, M. Disjuncta, Liris aurulentus, Tachysphex bengalensis. Our studies indicate that occurrence of barbs on lancets correlates with the degree of sociality and sting autotomy is more pronounced in swarm-founding species than in haplometrotic species. The number of barbs on the lancets varied from 0 to 11. Additionally SEM images also revealed interesting characters of barbs.

Keywords: altruistic, barbs, sociality, sting autotomy

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Authors: Alexander A. Karabutov, Natalia B. Podymova, Elena B. Cherepetskaya

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The theoretical analysis is carried out to get the relation between the ultrasonic wave velocity and the value of residual stresses. The laser-ultrasonic method is developed to evaluate the residual stresses and subsurface defects in metals. The method is based on the laser thermooptical excitation of longitudinal ultrasonic wave sand their detection by a broadband piezoelectric detector. A laser pulse with the time duration of 8 ns of the full width at half of maximum and with the energy of 300 µJ is absorbed in a thin layer of the special generator that is inclined relative to the object under study. The non-uniform heating of the generator causes the formation of a broadband powerful pulse of longitudinal ultrasonic waves. It is shown that the temporal profile of this pulse is the convolution of the temporal envelope of the laser pulse and the profile of the in-depth distribution of the heat sources. The ultrasonic waves reach the surface of the object through the prism that serves as an acoustic duct. At the interface ‚laser-ultrasonic transducer-object‘ the conversion of the most part of the longitudinal wave energy takes place into the shear, subsurface longitudinal and Rayleigh waves. They spread within the subsurface layer of the studied object and are detected by the piezoelectric detector. The electrical signal that corresponds to the detected acoustic signal is acquired by an analog-to-digital converter and when is mathematically processed and visualized with a personal computer. The distance between the generator and the piezodetector as well as the spread times of acoustic waves in the acoustic ducts are the characteristic parameters of the laser-ultrasonic transducer and are determined using the calibration samples. There lative precision of the measurement of the velocity of longitudinal ultrasonic waves is 0.05% that corresponds to approximately ±3 m/s for the steels of conventional quality. This precision allows one to determine the mechanical stress in the steel samples with the minimal detection threshold of approximately 22.7 MPa. The results are presented for the measured dependencies of the velocity of longitudinal ultrasonic waves in the samples on the values of the applied compression stress in the range of 20-100 MPa.

Keywords: laser-ultrasonic method, longitudinal ultrasonic waves, metals, residual stresses

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Authors: Vaishali Joshi

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In the past, companies and buyers operated as if there was infinite availability of natural resources for usage, which has resulted in the loss of our globe's natural ecosystem. People's consciousness of ecological concerns had increased, which showed the way for the evolution of the green revolution with the objective of discontinuing the use of products that are harmful to the ecosystem of the earth. This green revolution has made the consumers head toward those companies which are providing eco-friendly products s/service s through less eco-harmful ways. Studies show that companies started gaining a reputation in the market through their eco-friendly activities in their business. Hence companies should be alert to understand the consumer's environmentally friendly consumption behavior to survive and be in the game of the competition. Green marketing efforts guarantee beneficial exchanges without harmful consequences for current and /or upcoming generations. This hits the green policies of those companies which are claiming environmental concern. This means that these companies not only focus on the impact of their production and products on the ecosystem but also on every small activity in their value chain. One of the most ignored parts of the value chain is the medium through which the marketing of products/services is done. These companies should also take into account to what degree their selection of advertising media affects the ecosystem of the earth. In this study, a hypothetical fashion apparel brand known as "Dolphin" will be studied. In particular, the following objectives are framed: i) to study the brand attitude of the given fashion brand due to its selection of eco-friendly advertising medium ii) to study the advertisement attitude of the given fashion brand due to its selection of eco-friendly advertising medium and iii) to study the purchase intention of the given fashion brand due to its selection of eco-friendly advertising medium. An online experiment will be conducted. Respondents between the ages of 20-and 64 years will be selected randomly from the online consumer panel database. The findings of this study will have a great impact on the companies that are claiming environmental concerns by understanding how the advertising media is affecting the company’s brand image in the long run.

Keywords: eco-friendly advertising media, fashion, attitude, purchase intention

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Authors: Xuan Zhao, Wen Jiang

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In this study, a web crawler was used to collect POI sample data from 38 districts and counties of Chongqing in 2022, and ArcGIS was combined to coordinate and projection conversion and realize data visualization. Nuclear density analysis and spatial correlation analysis were used to explore the spatial distribution characteristics of elderly care facilities in Chongqing, and K mean cluster analysis was carried out with GeoDa to study the spatial concentration degree of elderly care resources in 38 districts and counties. Finally, the driving force of spatial differentiation of elderly care facilities in various districts and counties of Chongqing is studied by using the method of geographic detector. The results show that: (1) in terms of spatial distribution structure, the distribution of elderly care facilities in Chongqing is unbalanced, showing a distribution pattern of ‘large dispersion and small agglomeration’ and the asymmetric pattern of ‘west dense and east sparse, north dense and south sparse’ is prominent. (2) In terms of the spatial matching between elderly care resources and the elderly population, there is a weak coordination between the input of elderly care resources and the distribution of the elderly population at the county level in Chongqing. (3) The analysis of the results of the geographical detector shows that the single factor influence is mainly the number of elderly population, public financial revenue and district and county GDP. The high single factor influence is mainly caused by the elderly population, public financial income, and district and county GDP. The influence of each influence factor on the spatial distribution of elderly care facilities is not simply superimposed but has a nonlinear enhancement effect or double factor enhancement. It is necessary to strengthen the synergistic effect of two factors and promote the synergistic effect of multiple factors.

Keywords: aging, elderly care facilities, spatial differentiation, geographical detector, driving force analysis, Mountain city

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Authors: Siddarth Kannan

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Objectives: Deep Brain Stimulation (DBS) and Motor Cortex stimulation (MCS) are innovative interventions in order to treat various neuropathic pain disorders such as post-stroke pain. While each treatment has a varying degree of success in managing pain, comparative analysis has not yet been performed, and the success rates of these techniques using validated, objective pain scores have not been synthesised. The aim of this study was to compare the effect of pain relief offered by MCS and DBS on patients with post-stroke pain and to assess if either of these procedures offered better results. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines (PROSPEROID CRD42021277542). Three databases were searched, and articles published from 2000 to June 2023 were included (last search date 25 June 2023). Meta-analysis was performed using random effects models. We evaluated the performance of DBS or MCS by assessing studies that reported pain relief using the Visual Analogue Scale (VAS). Data analysis of descriptive statistics was performed using SPSS (Version 27; IBM; Armonk; NY; USA). R statistics (Rstudio Version 4.0.1) was used to perform meta-analysis. Results: Of the 478 articles identified, 27 were included in the analysis (232 patients- 117 DBS & 115 MCS). The pooled number of patients who improved after DBS was 0.68 (95% CI, 0.57-0.77, I2=36%). The pooled number of patients who improved after MCS was 0.72 (95% CI, 0.62-0.80, I2=59%). Further sensitivity analysis was done to include only studies with a minimum of 5 patients in order to assess if there was any impact on the overall results. Nine studies each for DBS and MCS met these criteria. There seemed to be no significant difference in results. Conclusions: The use of surgical interventions such as DBS and MCS is an upcoming field for the treatment of post-stroke pain, with limited studies exploring and comparing these two techniques. While our study shows that MCS might be a slightly better treatment option, further research would need to be done in order to determine the appropriate surgical intervention for post-stroke pain.

Keywords: post-stroke pain, deep brain stimulation, motor cortex stimulation, pain relief

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Authors: Firouz Amani, Adalat Hoseinian, Sajjad Hakimian

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Background: The mortality due to Myocardial Infarction (MI) is often occur during the first hours after onset of symptom. So, for taking the necessary treatment and decreasing the mortality rate, timely visited of the hospital could be effective in this regard. The aim of this study was to investigate the impact of effective factors in mortality of MI patients by using Linear Logistic Regression. Materials and Methods: In this case-control study, all patients with Acute MI who referred to the Ardabil city hospital were studied. All of died patients were considered as the case group (n=27) and we select 27 matched patients without Acute MI as a control group. Data collected for all patients in two groups by a same checklist and then analyzed by SPSS version 24 software using statistical methods. We used the linear logistic regression model to determine the effective factors on mortality of MI patients. Results: The mean age of patients in case group was significantly higher than control group (75.1±11.7 vs. 63.1±11.6, p=0.001).The history of non-cardinal diseases in case group with 44.4% significantly higher than control group with 7.4% (p=0.002).The number of performed PCIs in case group with 40.7% significantly lower than control group with 74.1% (P=0.013). The time distance between hospital admission and performed PCI in case group with 110.9 min was significantly upper than control group with 56 min (P=0.001). The mean of delay time from Onset of symptom to hospital admission (patient delay) and the mean of delay time from hospital admissions to receive treatment (system delay) was similar between two groups. By using logistic regression model we revealed that history of non-cardinal diseases (OR=283) and the number of performed PCIs (OR=24.5) had significant impact on mortality of MI patients in compare to other factors. Conclusion: Results of this study showed that of all studied factors, the number of performed PCIs, history of non-cardinal illness and the interval between onset of symptoms and performed PCI have significant relation with morality of MI patients and other factors were not meaningful. So, doing more studies with a large sample and investigated other involved factors such as smoking, weather and etc. is recommended in future.

Keywords: acute MI, mortality, heart failure, arrhythmia

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Authors: Laurie U. deBettencourt

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During pre-service field experiences teacher candidates are often asked to reflect as part of their training and in this investigation candidates’ reflective journal entries were reviewed, coded and analyzed with results suggesting teacher candidates need more direct instruction on how to describe, analyze, and make judgements on their instructional practices so that their practices improve over time. Teacher education programs often incorporate reflective-based activities during field experiences. The purpose of this investigation was to determine if special education teacher candidate’s reflective practices changed as they completed their two supervised field experiences and to determine what topics the candidates focused on in their reflections. The six females graduate students were completing two field experiences in special education classrooms within one academic year as part of their coursework leading to a master’s degree and special education teacher state certification. Each candidate wrote 15 reflection journal entries (approximately 200 words each) per field experience. Each of the journal entries were reviewed sentence by sentence to determine a reflective practice score and to determine the topics discussed. The reflective practice score was calculated using four dimensions of reflection (describe, analyze, judge, and apply) in order to create a continuous variable representing their reflective practice across four points of time. A One-way Repeated Measures Analysis of Variance (ANOVA) suggested that special education teacher candidates did not change their reflective practices over time (i.e., at time-point one the practitioner’s mean score was 56.0 out of 100 (SD = 7.6), 53.8 (SD = 4.3) at time-point two, 51.2 (SD = 4.5) at time-point three, and 57.7 (SD = 8.2) at time-point four). Qualitative findings suggest candidates focused mostly on themselves in their reflections. Conclusions suggest the need for teacher preparation programs to provide more direct instruction on how a teacher should reflect. Specific implications are provided for teacher training and future research.

Keywords: field experiences, reflective practices, special educators, teacher preparation

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Authors: Josephine K. Mule, Levi Obonyo

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Technology has changed human life over time. The COVID-19 pandemic has altered the work set-up, the school system, the shopping experience, church attendance, and even the way athletes train in Kenya. Although the use of technology to communicate and maintain interactions has been on the rise in the last 30 years, the uptake during the COVID-19 pandemic has been unprecedented. Traditionally, ‘paid’ work has been considered to take place outside the “home house” but COVID-19 has resulted in what is now being referred to as “the world’s largest work-from-home experiment” with up to 43 percent of employees working at least some of the time remotely. This study was conducted on 90 respondents from across remote work set-ups, school systems, merchants and customers of online shopping, church leaders and congregants and athletes, and their coaches. Data were collected by questionnaires and interviews that were conducted online. The data is based on the first three months since the first case of coronavirus was reported in Kenya. This study found that the use of technology is in the center of working remotely with work interactions being propelled on various online platforms including, Zoom, Microsoft Teams, and Google Meet, among others. The school system has also integrated the use of technology, including students defending their thesis/dissertations online and university graduations being conducted virtually. Kenya is known for its long-distance runners, due to the directives to reduce interactions; coaches have taken to providing their athletes with guidance on training on social media using applications such as WhatsApp. More local stores are now offering the shopping online option to their customers. Churches have also felt the brunt of the situation, especially because of the restrictions on crowds resulting in online services becoming more popular in 2020 than ever before. Artists, innovatively have started online musical concerts. The findings indicate that one of the outcomes in the Kenyan society that is evident as a result of the COVID-19 period is a population that is using technology more to communicate and get work done. Vices that have thrived in this season where the use of technology has increased, include the spreading of rumors on social media and cyberbullying. The place of technology seems to have been cemented by demand during this period.

Keywords: communication, coronavirus, COVID-19, Kenya, technology

Procedia PDF Downloads 135

Authors: Robert Cazar, Nathaly Maza

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Energy drinks and sports drinks are quite popular among young adults and teenagers worldwide. Some concerns regarding their health effects – particularly those of the energy drinks - have been raised based on scientific findings. Differentiating between these two types of drinks by means of their chemical properties seems to be an instructive task. Chemometrics provides the most appropriate strategy to do so. In this study, a discrimination analysis of the energy and sports drinks has been carried out applying chemometric methods. A set of eleven samples of available commercial brands of drinks – seven energy drinks and four sports drinks – were collected. Each sample was characterized by eight chemical variables (carbohydrates, energy, sugar, sodium, pH, degrees Brix, density, and citric acid). The data set was standardized and examined by exploratory chemometric techniques such as clustering and principal component analysis. As a preliminary step, a variable selection was carried out by inspecting the variable correlation matrix. It was detected that some variables are redundant, so they can be safely removed, leaving only five variables that are sufficient for this analysis. They are sugar, sodium, pH, density, and citric acid. Then, a hierarchical clustering `employing the average – linkage criterion and using the Euclidian distance metrics was performed. It perfectly separates the two types of drinks since the resultant dendogram, cut at the 25% similarity level, assorts the samples in two well defined groups, one of them containing the energy drinks and the other one the sports drinks. Further assurance of the complete discrimination is provided by the principal component analysis. The projection of the data set on the first two principal components – which retain the 71% of the data information – permits to visualize the distribution of the samples in the two groups identified in the clustering stage. Since the first principal component is the discriminating one, the inspection of its loadings consents to characterize such groups. The energy drinks group possesses medium to high values of density, citric acid, and sugar. The sports drinks group, on the other hand, exhibits low values of those variables. In conclusion, the application of chemometric methods on a data set that features some chemical properties of a number of energy and sports drinks provides an accurate, dependable way to discriminate between these two types of beverages.

Keywords: chemometrics, clustering, energy drinks, principal component analysis, sports drinks

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Authors: Janmejoy Gupta, Arnab Paul, Manjari Chakraborty

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Jharkhand is a state located in the eastern part of India. The Tropic of Cancer (23.5 degree North latitude line) passes through Ranchi district in Jharkhand. Mud huts with burnt clay tiled roofs in Jharkhand are an integral component of the state’s vernacular architecture. They come in various shapes, with a number of them having a courtyard type of plan. In general, it has been stated that designing dwellings with courtyards in them is a climate-responsive strategy in composite climate. The truth behind this hypothesis is investigated in this paper. In this paper, three types of mud huts with courtyards situated in Ranchi district in Jharkhand are taken as a study and through temperature measurements in the south-side rooms and courtyards, in addition to Autodesk Ecotect (Version 2011) software simulations, their thermal performance throughout the year are observed. Temperature measurements are specifically taken during the peak of summer and winter and the average temperatures in the rooms and courtyards during seven day-periods in peak of summer and peak of winter are plotted graphically. Thereafter, on the basis of the study and software simulations, the hypothesis is verified and the thermally better performing dwelling types in summer and winter identified among the three sub-types studied. Certain recommendations with respect to increasing thermal comfort in courtyard type mud huts in general are also made. It is found that all courtyard type dwellings do not necessarily show better thermal performance in summer and winter in composite climate. The U shaped dwelling with open courtyard on southern side offers maximum amount of thermal-comfort inside the rooms in the hotter part of the year and the square hut with a central courtyard, with the courtyard being closed from all sides, shows superior thermal performance in winter. The courtyards in all the three case-studies are found to get excessively heated up during summer.

Keywords: courtyard, mud huts, simulations, temperature measurements, thermal performance

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Authors: Mohamed Saad, Huda Ismail

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The purpose of this research is to examine the impact of cryptocurrency classification on money laundering crimes and to analyze how the preferences of criminals differ according to the type of digital currency used. Specifically, we aim to explore the roles of stablecoins, utility coins, and privacy tokens in facilitating or hindering money laundering activities and to identify the key factors that influence the choices of criminals in using these cryptocurrencies. To achieve our research objectives, we used a dataset for the most highly traded cryptocurrencies (32 currencies) that were published on the coin market cap for 2022. In addition to conducting a comprehensive review of the existing literature on cryptocurrency and money laundering, with a focus on stablecoins, utility coins, and privacy tokens, Furthermore, we conducted several Multivariate analyses. Our study reveals that the classification of cryptocurrency plays a significant role in money laundering activities, as criminals tend to prefer certain types of digital currencies over others, depending on their specific needs and goals. Specifically, we found that stablecoins are more commonly used in money laundering due to their relatively stable value and low volatility, which makes them less risky to hold and transfer. Utility coins, on the other hand, are less frequently used in money laundering due to their lack of anonymity and limited liquidity. Finally, privacy tokens, such as Monero and Zcash, are increasingly becoming a preferred choice among criminals due to their high degree of privacy and untraceability. In summary, our study highlights the importance of understanding the nuances of cryptocurrency classification in the context of money laundering and provides insights into the preferences of criminals in using digital currencies for illegal activities. Based on our findings, our recommendation to the policymakers is to address the potential misuse of cryptocurrencies for money laundering. By implementing measures to regulate stable coins, strengthening cross-border cooperation, fostering public-private partnerships, and increasing cooperation, policymakers can help prevent and detect money laundering activities involving digital currencies.

Keywords: crime, cryptocurrency, money laundering, tokens.

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Authors: Taiwo Hassanat Bawa-Muhammad, Opeoluwa Hope Adegoke

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Introduction: This study aims to examine the knowledge and perceptions of preconception care among healthcare workers in Nigeria, recognizing its crucial role in ensuring safe pregnancies. Despite its significance, awareness of preconception care remains low in the country. The study seeks to assess the understanding of preconception services and identify the barriers that hinder their efficacy. Methods: Through semi-structured interviews, 129 healthcare workers across six states in Nigeria were interviewed between January and March 2023. The interviews explored the healthcare workers' knowledge of preconception care practices, the socio-cultural influences shaping decision-making, and the challenges that limit accessibility and utilization of preconception care services. Results: The findings reveal a limited knowledge of preconception care among healthcare workers, primarily due to inadequate information dissemination within the healthcare system. Additionally, cultural beliefs significantly influence perceptions surrounding preconception care. Furthermore, financial constraints, distance to healthcare facilities, and poor health infrastructure disproportionately restrict access to preconception services, particularly for vulnerable populations. The study also highlights insufficient skills and outdated training among healthcare workers regarding preconception guidance, primarily attributed to limited opportunities for professional development. Discussion: To improve preconception care in Nigeria, comprehensive education programs must be implemented, taking into account the societal influences that shape perceptions and behaviors. These programs should aim to dispel myths and promote evidence-based practices. Additionally, training healthcare workers and integrating preconception care services into primary care settings, with support from religious and community leaders, can help overcome barriers to access. Strategies should prioritize affordability while emphasizing the broader benefits of preconception care beyond fertility concerns alone. Lastly, widespread literacy campaigns utilizing trusted channels are crucial for effectively disseminating information and promoting the adoption of preconception practices in Nigeria.

Keywords: preconception care, knowledge, healthcare workers, Nigeria, barriers, education, training

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Authors: D. Anderlini, G. Wallis

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Background: The number of people experiencing stroke is steadily increasing due to changes in diet and lifestyle, to longer life expectancy resulting in older population, to higher survival rates as a consequence of improvements during the acute phase. This study considers what risk factors might contribute to delayed entry to hospital for treatment. Methods: We analyzed data from 2472 patients admitted to the Stroke Unit of the Royal Brisbane Women's Hospital, Australia, between 2002 to 2011. Results: Previous studies have reported that factors which can contribute to delay include the patient’s age, the time of day, physical location, visit the GP instead of going to the emergency, means of transport, severity of symptoms and type of stroke. Contrary to findings of other studies, we found a strong correlation between side of lesion and delay in admission: patients with right hemisphere lesions had an average delay of 3.78 days, while patients with left hemisphere lesions had an average delay of 1.49 days. Damage to the right hemisphere generally ends in motor impairment in the non-dominant hand and no speech impediment. In contrast, left hemisphere lesions can result in deficit to; dominant hand function and aphasia which will be noticed even if their impact on performance is relatively minor. A finding which goes against many previous studies, is the fact that women get to the hospital much sooner than men, showing an average delay of 0.92 days in women vs. 3.36 days in men. Conclusion: Acute surgical-pharmacological therapies are most effective if applied immediately after stroke. Hence delays to admission can be crucial to the degree of recovery. The tendency of patients to overlook symptoms of right hemisphere lesion should be the target of information campaigns both for the general public and GPs. Why do men go to hospital so late? We don't know yet! Nevertheless an awareness plan specifically direct to male population should be on the agenda of Health Departments.

Keywords: gender, admission delay, stroke location, bioinformatics, biomedicine

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Authors: S. Mohajeri

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Electrocodeposition of Ni-TiO2 nanocomposite single layers and Ni-TiO2/TiO2 multilayers from Watts bath containing TiO2 sol was carried out on copper substrate. Pulse plating and pulse reverse plating techniques were applied to facilitate higher incorporations of TiO2 nanoparticles in Ni-TiO2 nanocomposite single layers, and the results revealed that by prolongation of the current-off durations and the anodic cycles, deposits containing 11.58 wt.% and 13.16 wt.% TiO2 were produced, respectively. Multilayer coatings which consisted of Ni-TiO2 and TiO2-rich layers were deposited by pulse potential deposition through limiting the nickel deposition by diffusion control mechanism. The TiO2-rich layers thickness and accordingly, the content of TiO2 reinforcement reached 104 nm and 18.47 wt.%, respectively in the optimum condition. The phase structure and surface morphology of the nanocomposite coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The cross sectional morphology and line scans of the layers were studied by field emission scanning electron microscopy (FESEM). It was confirmed that the preferred orientations and the crystallite sizes of nickel matrix were influenced by the deposition technique parameters, and higher contents of codeposited TiO2 nanoparticles refined the microstructure. The corrosion behavior of the coatings in 1M NaCl and 0.5M H2SO4 electrolytes were compared by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Increase of corrosion resistance and the passivation tendency were favored by TiO2 incorporation, while the degree of passivation declined as embedded particles disturbed the continuity of passive layer. The role of TiO2 incorporation on the improvement of mechanical properties including hardness, elasticity, scratch resistance and friction coefficient was investigated by the means of atomic force microscopy (AFM). Hydrophilicity and wettability of the composite coatings were investigated under UV illumination, and the water contact angle of the multilayer was reduced to 7.23° after 1 hour of UV irradiation.

Keywords: electrodeposition, hydrophilicity, multilayer, pulse-plating

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Authors: Maria Ghorbanian, Mohammad Ghahramani, Mahmood Abolghasemi

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Universities and institutions of higher education in Iran, like other higher education institutions in the world, have a heavy mission and task to educate students based on the needs of the country. Taking on such a serious responsibility requires having a good governance system for planning, formulating executive plans, evaluating, and finally modifying them in accordance with the current conditions and challenges ahead. In this regard, the present study was conducted with the aim of identifying the components of good governance in the Iranian higher education system by survey method and with a quantitative approach. In order to collect data, a researcher-made questionnaire was used, which includes two parts: personal and professional characteristics (5 questions) and the three components of good governance in the Iranian higher education system, including good management and leadership (8 items), continuous evaluation and effective (university performance, finance, and university appointments) (8 items) and civic responsibility and sustainable development (7 items). These variables were measured and coded in the form of a five-level Likert scale from "Very Low = 1" to "Very High = 5". First, the validity and reliability of the research model were examined. In order to calculate the reliability of the questionnaire, two methods of Cronbach's alpha and combined reliability were used. Fornell-Larker interaction and criterion were also used to determine the degree of diagnostic validity. The statistical population of this study included all faculty members of public universities in Tehran (N = 4429). The sample size was estimated to be 340 using the Cochran's formula. These numbers were studied using a randomized method with a proportional assignment. The data were analyzed by the structural equation method with the least-squares approach. The results showed that the component of civil responsibility and sustainable development with a factor load of 0.827 is the most important element of good governance.

Keywords: good governance, higher education, sustainable, development

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Authors: Xi Wang, Yoshio Bando

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Lithium-ion batteries (LIBs) can deliver high levels of energy storage density and offer long operating lifetimes, but their power density is too low for many important applications. Therefore, we developed some new strategies and fabricated novel electrodes for fast Li transport and its facile synthesis including N-doped graphene-SnO2 sandwich papers, bicontinuous nanoporous Cu/Li4Ti5O12 electrode, and binder-free N-doped graphene papers. In addition, by using advanced in-TEM, STEM techniques and the theoretical simulations, we systematically studied and understood their storage mechanisms at the atomic scale, which shed a new light on the reasons of the ultrafast lithium storage property and high capacity for these advanced anodes. For example, by using advanced in-situ TEM, we directly investigated these processes using an individual CuO nanowire anode and constructed a LIB prototype within a TEM. Being promising candidates for anodes in lithium-ion batteries (LIBs), transition metal oxide anodes utilizing the so-called conversion mechanism principle typically suffer from the severe capacity fading during the 1st cycle of lithiation–delithiation. Also we report on the atomistic insights of the GN energy storage as revealed by in situ TEM. The lithiation process on edges and basal planes is directly visualized, the pyrrolic N "hole" defect and the perturbed solid-electrolyte-interface (SEI) configurations are observed, and charge transfer states for three N-existing forms are also investigated. In situ HRTEM experiments together with theoretical calculations provide a solid evidence that enlarged edge {0001} spacings and surface "hole" defects result in improved surface capacitive effects and thus high rate capability and the high capacity is owing to short-distance orderings at the edges during discharging and numerous surface defects; the phenomena cannot be understood previously by standard electron or X-ray diffraction analyses.

Keywords: in-situ TEM, STEM, advanced anode, lithium-ion batteries, storage mechanism

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Authors: John Olav Bjornestad, Bjorn Tore Johansen

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The number of people suffering from mental illnesses is increasing, and such illness is currently one of the major causes of disability and poor health. The reason for this is most likely a lack of physical activity. The purpose of this study was to discover if physical activity was an effective mode of treatment for psychiatric patients at an out-patient treatment facility. The study included an exploration of whether or not patients having physical activity included as an integral part of their treatment (to a greater degree than do patients who are physically inactive) would achieve 1) an improvement in their physical condition 2) a reduction in symptomatic pressure and 3) an increase in their health-related quality of life. The intervention period lasted a total of 12 weeks. The training group completed a minimum of 2 training sessions per week with an intensity of 60-75% of maximum heart rate. The participants’ health-related quality of life (SF-36), symptomatic pressure (SCL-90-R) and physical condition (UKK-walking test) were measured before and after intervention. Twenty participants were pre-tested, and out of this initial group, nine patients completed the intervention program and participated thereafter in post-testing. The results showed that participants on average improved their physical condition, reduced their symptomatic pressure and increased their health-related quality of life over the course of the intervention period. The training group experienced significant changes in their symptomatic pressure (the anxiety dimension) and health-related quality of life (the mental health dimension) from the pre-testing stage to the post-testing one. Furthermore, there was a significant connection between symptomatic pressure and health-related quality of life. The patients who were admitted to the psychiatric out-patient clinic were in a physical condition that was significantly poorer than that of persons of the same age in the remainder of the population. Experiences from the study and the relatively large defection from it demonstrate that there is a great need for close follow-up of psychiatric patients’ physical activity levels when physical activity and lifestyle changes are included as part of their treatment program.

Keywords: health-related quality, mental health, physical activity, physical condition

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Authors: Tomasz Komornicki

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The primary aim of the presentation is to try to model border traffic and, at the same time to explain on which economic variables the intensity of border traffic depended in the long term. For this purpose, long series of traffic data on the Polish borders were used. Models were estimated for three variants of explanatory variables: a) for total arrivals and departures (total movement of Poles and foreigners), b) for arrivals and departures of Poles, and c) for arrivals and departures of foreigners. Each of the defined explanatory variables in the models appeared as the logarithm of the natural number of persons. Data from 1994-2017 were used for modeling (for internal Schengen borders for the years 1994-2007). Information on the number of people arriving in and leaving Poland was collected for a total of 303 border crossings. On the basis of the analyses carried out, it was found that one of the main factors determining border traffic is generally differences in the level of economic development (GDP) and the condition of the economy (level of unemployment) and the degree of border permeability. Also statistically significant for border traffic are differences in the prices of goods (fuels, tobacco, and alcohol products) and services (mainly basic ones, e.g., hairdressing services). Such a relationship exists mainly on the eastern border (border traffic determined largely by differences in the prices of goods) and on the border with Germany (in the first analysed period, border traffic was determined mainly by the prices of goods, later - after Poland's accession to the EU and the Schengen area - also by the prices of services). The models also confirmed differences in the set of factors shaping the volume and structure of border traffic on the Polish borders resulting from general geopolitical conditions, with the year 2007 being an important caesura, after which the classical population mobility factors became visible. The results obtained were additionally related to changes in traffic that occurred as a result of the CPOVID-19 pandemic and as a result of the Russian aggression against Ukraine.

Keywords: border, modal structure, transport, Ukraine

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Authors: Yasàlu Haruna

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In every transaction, the use of language is central regardless of form or complexity if any meaning is expected to be harvested therefrom. Students constituting a population group in the learning landscape of Nigeria occupy a central position with a propensity to excel or otherwise in the context of communication, especially in the learning process and social interaction. The nature or quantum of anxiety or confidence in speaking a second language is not only peculiar to societies where the second language is not an official language but to a degree, the linguistic gap created by adoption and adaptation syndrome manifests in created anxiety or lack of confidence especially where mastery of a spoken language becomes a major challenge. This paper explores the manner in which linguistic complexity and cultural barriers combine to widen the adaptation and adoption gap. In much the same way, typical issues of pronouncement, intonation and accent difficulties are vital variables that explain the root cause of anxiety. Using a combination of primary and secondary sources of data expressed in questionnaires, key informant interviews and other available data, the paper concludes that the non-integration of anxiety possibility into the education delivery framework has left a lot to be needed in cultivating second language speakers among students of Nigerian Colleges of Education. In addition, cultural barriers and the absence of integration interfaces in the course of learning within and outside the classroom contribute to further widening the gap. Again, colleagues/mates/conversation partners' mastery of a second language remains a contributory factor largely due to the quality of the preparatory school system in many parts of the country. The paper recommends that national policies and frameworks must be reviewed to consider integration windows where culture and conversation partner deficiencies can be remedied through educational events such as debates, quizzes and symposia; improvements can be attained while commercial advertisements are tailored towards seeking for adoption of second language in commerce and major cultural activities.

Keywords: cultural barriers, integration, college of education and adaptation, second language

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Authors: Peng Zhang, Lihui Zheng, Xiangchun Wang, Xiaopan Kou

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Quantitative research on the main control factors of lost circulation has few considerations and single data source. Using Unmanned Intervention Algorithm to find the main control factors of lost circulation adopts all measurable parameters. The degree of lost circulation is characterized by the loss rate as the objective function. Geological, engineering and fluid data are used as layers, and 27 factors such as wellhead coordinates and WOB are used as dimensions. Data classification is implemented to determine function independent variables. The mathematical equation of loss rate and 27 influencing factors is established by multiple regression method, and the undetermined coefficient method is used to solve the undetermined coefficient of the equation. Only three factors in t-test are greater than the test value 40, and the F-test value is 96.557%, indicating that the correlation of the model is good. The funnel viscosity, final shear force and drilling time were selected as the main control factors by elimination method, contribution rate method and functional method. The calculated values of the two wells used for verification differ from the actual values by -3.036m3/h and -2.374m3/h, with errors of 7.21% and 6.35%. The influence of engineering factors on the loss rate is greater than that of funnel viscosity and final shear force, and the influence of the three factors is less than that of geological factors. Quantitatively calculate the best combination of funnel viscosity, final shear force and drilling time. The minimum loss rate of lost circulation wells in Shunbei area is 10m3/h. It can be seen that man-made main control factors can only slow down the leakage, but cannot fundamentally eliminate it. This is more in line with the characteristics of karst caves and fractures in Shunbei fault solution oil and gas reservoir.

Keywords: drilling and completion, drilling fluid, lost circulation, loss rate, main controlling factors, unmanned intervention algorithm

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Authors: Mahmoud Roushdy, Mohamed El Naggar, Ahmed Yehia Abdelaziz

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Anchored sheet pile has been used worldwide as front quay walls for decades. With the increase in vessel drafts and weights, those sheet pile walls need to be upgraded by increasing the depth of the dredging line in front of the wall. A system has recently been used to increase the depth in front of the wall by installing a separated platform supported on a deep foundation (so called Relieving Platform) behind the sheet pile wall. The platform is structurally separated from the front wall. This paper presents a numerical investigation utilizing finite element analysis on the behavior of separated relieve platforms installed within existing anchored sheet pile quay walls. The investigation was done in two steps: a verification step followed by a parametric study. In the verification step, the numerical model was verified based on field measurements performed by others. The validated model was extended within the parametric study to a series of models with different backfill soils, separation gap width, and number of pile rows supporting the platform. The results of the numerical investigation show that using stiff clay as backfill soil (neglecting consolidation) gives better performance for the front wall and the first pile row adjacent to sandy backfills. The degree of compaction of the sandy backfill slightly increases lateral deformations but reduces bending moment acting on pile rows, while the effect is minor on the front wall. In addition, the increase in the separation gap width gradually increases bending moments on the front wall regardless of the backfill soil type, while this effect is reversed on pile rows (gradually decrease). Finally, the paper studies the possibility of reducing the number of pile rows along with the separation to take advantage of the positive separation effect on piles.

Keywords: anchored sheet pile, relieving platform, separation gap, upgrade quay wall

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Authors: H. Aljabiry, L. Bailey, S. Young

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Qatar is a desert with an average temperature 37⁰C, reaching over 40⁰C during summer. Precipitation is uncommon and mostly in winter. Qatar depends on desalination for drinking water and on groundwater and recycled water for irrigation. Water consumption and network leakage per capita in Qatar are amongst the highest in the world; re-use of treated wastewater is extremely limited with only 14% of treated wastewater being used for irrigation. This has led to the country disposing of unwanted water from various sources in lagoons situated around the country, causing concern over the possibility of environmental pollution. Accordingly, our hypothesis underpinning this research is that the quality and quantity of water in lagoons is having an impact on the groundwater reservoirs in Qatar. Lagoons (n = 14) and wells (n = 55) were sampled for both summer and winter in 2018 (summer and winter). Water, adjoining soil and plant samples were analysed for multiple elements by Inductively Coupled Plasma Mass Spectrometry. Organic and inorganic carbon were measured (CN analyser) and the major anions were determined by ion chromatography. Salinization in both the lagoon and the wells was seen with good correlations between Cl⁻, Na⁺, Li, SO₄, S, Sr, Ca, Ti (p-value < 0.05). Association of heavy metals was observed of Ni, Cu, Ag, and V, Cr, Mo, Cd which is due to contamination from anthropological activities such as wastewater disposal or spread of contaminated dust. However, looking at each elements none of them exceeds the Qatari regulation. Moreover, gypsum saturation in the system was observed in both the lagoon and wells water samples. Lagoons and the water of the well are found to be of a saline type as well as Ca²⁺, Cl⁻, SO₄²⁻ type evidencing both gypsum dissolution and salinization in the system. Moreover, Maps produced by Inverse distance weighting showed an increasing level of Nitrate in the groundwater in winter, and decrease chloride and sulphate level, indicating recharge effect after winter rain events. While E. coli and faecal bacteria were found in most of the lagoons, biological analysis for wells needs to be conducted to understand the biological contamination from lagoon water infiltration. As a conclusion, while both the lagoon and the well showed the same results, more sampling is needed to understand the impact of the lagoons on the groundwater.

Keywords: groundwater quality, lagoon, treated wastewater, water management, wastewater treatment, wetlands

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Authors: Lidija R. Jevrić, Sanja O. Podunavac-Kuzmanović, Strahinja Z. Kovačević

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Quantitative structure-retention relationship (QSRR) analysis was used to predict the chromatographic behavior of s-triazine derivatives by using theoretical descriptors computed from the chemical structure. Fundamental basis of the reported investigation is to relate molecular topological descriptors with chromatographic behavior of s-triazine derivatives obtained by reversed-phase (RP) thin layer chromatography (TLC) on silica gel impregnated with paraffin oil and applied ethanol-water (φ = 0.5-0.8; v/v). Retention parameter (RM0) of 14 investigated s-triazine derivatives was used as dependent variable while simple connectivity index different orders were used as independent variables. The best QSRR model for predicting RM0 value was obtained with simple third order connectivity index (3χ) in the second-degree polynomial equation. Numerical values of the correlation coefficient (r=0.915), Fisher's value (F=28.34) and root mean square error (RMSE = 0.36) indicate that model is statistically significant. In order to test the predictive power of the QSRR model leave-one-out cross-validation technique has been applied. The parameters of the internal cross-validation analysis (r2CV=0.79, r2adj=0.81, PRESS=1.89) reflect the high predictive ability of the generated model and it confirms that can be used to predict RM0 value. Multivariate classification technique, hierarchical cluster analysis (HCA), has been applied in order to group molecules according to their molecular connectivity indices. HCA is a descriptive statistical method and it is the most frequently used for important area of data processing such is classification. The HCA performed on simple molecular connectivity indices obtained from the 2D structure of investigated s-triazine compounds resulted in two main clusters in which compounds molecules were grouped according to the number of atoms in the molecule. This is in agreement with the fact that these descriptors were calculated on the basis of the number of atoms in the molecule of the investigated s-triazine derivatives.

Keywords: s-triazines, QSRR, chemometrics, chromatography, molecular descriptors

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Authors: Wondmnew Derebe Yohannis

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Farming irrigation plays a crucial role in rural development strategies, impacting both annual household income and livelihood. This research aims to evaluate the factors influencing irrigation participation and assess the impact of small-scale irrigation on rural households' annual income. The study collected data from 287 farmers in the Dahana district of northern Ethiopia. The research investigates the driving forces behind farmers' decisions to adopt small-scale irrigation and its effect on annual income gain. The findings reveal that several factors positively influence the probability of adoption, including access to credit, cultivated land size, livestock holding, extension contact, and the education level of the household head. Conversely, the distance to local markets and water schemes negatively affects the likelihood of adoption. To understand the differences in annual income between farm households that adopted irrigation and those that did not, a simultaneous equations model with endogenous switching regression is estimated. This accounts for the heterogeneity in the adoption decision and unobservable characteristics of farmers and their farms. The analysis compares the expected income gain under actual and counterfactual scenarios, considering whether the farm household adopted irrigation or not. The study reveals that the group of farm households that adopted irrigation has distinct characteristics compared to those that did not adopt it. Furthermore, the research demonstrates that the adoption of irrigation practices leads to an increase in annual income. Interestingly, the impact of small-scale irrigation on annual income is greater for the farm households that actually adopted irrigation compared to those in the counterfactual scenario where they did not adopt. Based on the findings, the researcher concludes that small-scale irrigation is a practical solution for meeting household financial needs in the study area. It is recommended that investments in small-scale irrigation continue to further improve the livelihoods of rural farming communities by enhancing annual income gains.

Keywords: small-scale irrigation, income, rural farm households, endogenous switching regression, user, non-user

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Authors: Arlene Caney, Linda Fellag

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To counter the adverse effect of Covid-19 on college student success, two faculty members at a US community college have used web-based assessment data to improve curricula and, thus, student outcomes. This case study exemplifies how “closing the loop” by analyzing outcome assessments in real time can improve student learning for academically underprepared students struggling during the pandemic. The purpose of the study was to develop ways to mitigate the negative impact of Covid-19 on student success of underprepared college students. Using the Assessment, Evaluation, Feedback and Intervention System (AEFIS) and other assessment tools provided by the college’s Office of Institutional Research, an English professor and a Music professor collected data in skill areas related to their curricula over four semesters, gaining insight into specific course sections and learners’ performance across different Covid-driven course formats—face-to-face, hybrid, synchronous, and asynchronous. Real-time data collection allowed faculty to shorten and close the assessment loop, and prompted faculty to enhance their curricula with engaging material, student-centered activities, and a variety of tech tools. Frequent communication, individualized study, constructive criticism, and encouragement were among other measures taken to enhance teaching and learning. As a result, even while student success rates were declining college-wide, student outcomes in these faculty members’ asynchronous and synchronous online classes improved or remained comparable to student outcomes in hybrid and face-to-face sections. These practices have demonstrated that even high-risk students who enter college with remedial level language and mathematics skills, interrupted education, work and family responsibilities, and language and cultural diversity can maintain positive outcomes in college across semesters, even during the pandemic.

Keywords: AEFIS, assessment, distance education, institutional research center

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Authors: Bikram Jung Kunwar

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Forests have central roles in climate change. The conservation of forests sequestrates the carbon from the atmosphere and also regulates the carbon cycle. However, knowingly and unknowingly the world’s forests were deforested and degraded annually at the rate of 0.18% and emitted the carbon to the atmosphere. The IPCC reports claimed that the deforestation and forest degradation accounts 1/5th of total carbon emission, which is second position after fossil fuels. Since 1.6 billion people depend on varying degree on forests for their daily livelihood, not all deforestation are undesirable. Therefore, to conserve the forests and find the livelihood opportunities for forest surrounding people is prerequisites to address the climate change problems especially in developing countries, and also a growing concern to the forestry sector researchers, planners and policy makers. The study examines the role of community based forest management in carbon mitigation and adaptation taking the examples of Nepal’s community forestry program. In the program, the government hands over a part of national forests to the local communities with sole forest management authorities. However, the government itself retained the ownership rights of forestland. Local communities organized through a local institution called Community Forest User Group (CFUG) managed the forests. They also formed an operational plan with technical prescriptions and a constitution with forest management rules and regulations. The implementation results showed that the CFUGs are not only found effective to organize the local people and construct a local institution to forest conservation and management activities, but also they are able to collect a community fund from the sale of forest products and carried out various community development activities. These development activities have decisive roles to improve the livelihood of forest surrounding people and eventually to address the climate change problems.

Keywords: climate change, community forestry, local institution, Nepal

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Authors: Erika Csanyi, Gyula Sandor

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In the course of the examination, we sought to answer the question of how and to what extent the home range and daily activity of a deer stag relocated from its habitual surroundings changes. We conducted the examination in two hunting areas in Hungary, about 50 km from one another. The control area was in the north of Somogy County, while the sample area was an area of similar features in terms of forest cover, tree stock, agricultural structure, altitude above sea level, climate, etc. in the south of Somogy County. Three middle-aged red deer stags were captured with rocket nets, immobilized and marked with GPS-Plus Collars manufactured by Vectronic Aerospace Gesellschaft mit beschränkter Haftung. One captured species was relocated. We monitored deer movements over 24-hour periods at 3 months. In the course of the examination, we analysed the behaviour of the relocated species and those that remained in their original habitat, as well as the temporal evolution of their behaviour. We examined the characteristics of the marked species’ daily activities and the hourly distance they covered. We intended to find out the difference between the behaviour of the species remaining in their original habitat and of those relocated to a more distant, but similar habitat. In summary, based on our findings, it can be established that such enforced relocations to a different habitat (e.g., game relocation) significantly increases the home range of the species in the months following relocation. Home ranges were calculated using the full data set and the minimum convex polygon (MCP) method. Relocation did not increase the nocturnal and diurnal movement activity of the animal in question. Our research found that the home range of the relocated species proved to be significantly higher than that of those species that were not relocated. The results have been presented in tabular form and have also been displayed on a map. Based on the results, it can be established that relocation inherently includes the risk of falling victim to poaching, vehicle collision. It was only in the third month following relocation that the home range of the relocated species subsided to the level of those species that were not relocated. It is advisable to take these observations into consideration in relocating red deer for nature conservation or game management purposes.

Keywords: Cervus elaphus, home range, relocation, red deer stag

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Authors: Xiaoqing Liu, Kurt Friese, Karsten Rinke

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Lacustrine sediment archives rich paleoenvironmental information in lake and surrounding environment. Additionally, modern sediment is used as an effective medium for the monitoring of lake. Organic carbon in sediment is a heterogeneous mixture with varying turnover times and qualities which result from the different biogeochemical processes in the deposition of organic material. Therefore, the isolation of different carbon pools is important for the research of lacustrine condition in the lake. However, the numeric available fractionation procedures can hardly yield homogeneous carbon pools on terms of stability and age. In this work, a multi-step fractionation protocol that treated sediment with hot water, HCl, H2O2 and Na2S2O8 in sequence was adopted, the treated sediment from each step were analyzed for the isotopic and structural compositions with Isotope Ratio Mass Spectrometer coupled with element analyzer (IRMS-EA) and Solid-state 13C Nuclear Magnetic Resonance (NMR), respectively. The sequential extractions with hot-water, HCl, and H2O2 yielded a more homogeneous and C3 plant-originating OC fraction, which was characterized with an atomic C/N ratio shift from 12.0 to 20.8, and 13C and 15N isotopic signatures were 0.9‰ and 1.9‰ more depleted than the original bulk sediment, respectively. Additionally, the H2O2- resistant residue was dominated with stable components, such as the lignins, waxes, cutans, tannins, steroids and aliphatic proteins and complex carbohydrates. 6M HCl in the acid hydrolysis step was much more effective than 1M HCl to isolate a sedimentary OC fraction with higher degree of homogeneity. Owing to the extremely high removal rate of organic matter, the step of a Na2S2O8 oxidation is only suggested if the isolation of the most refractory OC pool is mandatory. We conclude that this multi-step chemical fractionation procedure is effective to isolate more homogeneous OC pools in terms of stability and functional structure, and it can be used as a promising method for OC pools fractionation of sediment or soil in future lake research.

Keywords: 13C-CPMAS-NMR, 13C signature, lake sediment, OC fractionation

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Authors: N. Casado-Sanz, B. Guirao

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The population aged 65 and over is projected to double in the coming decades. Due to this increase, driver population is expected to grow and in the near future, all countries will be faced with population aging of varying intensity and in unique time frames. This is the greatest challenge facing industrialized nations and due to this fact, the study of the relationships of dependency between population aging and road safety is becoming increasingly relevant. Although the deterioration of driving skills in the elderly has been analyzed in depth, to our knowledge few research studies have focused on the road infrastructure and the mobility of this particular group of users. In Spain, crosstown roads have one of the highest fatality rates. These rural routes have a higher percentage of elderly people who are more dependent on driving due to the absence or limitations of urban public transportation. Analysing road safety in these routes is very complex because of the variety of the features, the dispersion of the data and the complete lack of related literature. The objective of this paper is to identify key factors that cause traffic accidents. The individuals under study were the accidents with killed or seriously injured in Spanish crosstown roads during the period 2006-2015. Latent cluster analysis was applied as a preliminary tool for segmentation of accidents, considering population aging as the main input among other socioeconomic indicators. Subsequently, a linear regression analysis was carried out to estimate the degree of dependence between the accident rate and the variables that define each group. The results show that segmenting the data is very interesting and provides further information. Additionally, the results revealed the clear influence of the aging variable in the clusters obtained. Other variables related to infrastructure and mobility levels, such as the crosstown roads layout and the traffic intensity aimed to be one of the key factors in the causality of road accidents.

Keywords: cluster analysis, population ageing, rural roads, road safety

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