Search results for: high performance liquid chromatography
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 29451

Search results for: high performance liquid chromatography

5301 Mapping Structurally Significant Areas of G-CSF during Thermal Degradation with NMR

Authors: Mark-Adam Kellerman

Abstract:

Proteins are capable of exploring vast mutational spaces. This makes it difficult for protein engineers to devise rational methods to improve stability and function via mutagenesis. Deciding which residues to mutate requires knowledge of the characteristics they elicit. We probed the characteristics of residues in granulocyte-colony stimulating factor (G-CSF) using a thermal melt (from 295K to 323K) to denature it in a 700 MHz Bruker spectrometer. These characteristics included dynamics, micro-environmental changes experienced/ induced during denaturing and structure-function relationships. 15N-1H HSQC experiments were performed at 2K increments along with this thermal melt. We observed that dynamic residues that also undergo a lot of change in their microenvironment were predominantly in unstructured regions. Moreover, we were able to identify four residues (G4, A6, T133 and Q134) that we class as high priority targets for mutagenesis, given that they all appear in both the top 10% of measures for environmental changes and dynamics (∑Δ and ∆PI). We were also able to probe these NMR observables and combine them with molecular dynamics (MD) to elucidate what appears to be an opening motion of G-CSFs binding site III. V48 appears to be pivotal to this opening motion, which also seemingly distorts the loop region between helices A and B. This observation is in agreement with previous findings that the conformation of this loop region becomes altered in an aggregation-prone state of G-CSF. Hence, we present here an approach to profile the characteristics of residues in order to highlight their potential as rational mutagenesis targets and their roles in important conformational changes. These findings present not only an opportunity to effectively make biobetters, but also open up the possibility to further understand epistasis and machine learn residue behaviours.

Keywords: protein engineering, rational mutagenesis, NMR, molecular dynamics

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5300 Methods Employed to Mitigate Wind Damage on Ancient Egyptian Architecture

Authors: Hossam Mohamed Abdelfattah Helal Hegazi

Abstract:

Winds and storms are considered crucial weathering factors, representing primary causes of destruction and erosion for all materials on the Earth's surface. This naturally includes historical structures, with the impact of winds and storms intensifying their deterioration, particularly when carrying high-hardness sand particles during their passage across the ground. Ancient Egyptians utilized various methods to prevent wind damage to their ancient architecture throughout the ancient Egyptian periods . One of the techniques employed by ancient Egyptians was the use of clay or compacted earth as a filling material between opposing walls made of stone, bricks, or mud bricks. The walls made of reeds or woven tree branches were covered with clay to prevent the infiltration of winds and rain, enhancing structural integrity, this method was commonly used in hollow layers . Additionally, Egyptian engineers innovated a type of adobe brick with uniformly leveled sides, manufactured from dried clay. They utilized stone barriers, constructed wind traps, and planted trees in rows parallel to the prevailing wind direction. Moreover, they employed receptacles to drain rainwater resulting from wind-loaded rain and used mortar to fill gaps in roofs and structures. Furthermore, proactive measures such as the removal of sand from around historical and archaeological buildings were taken to prevent adverse effects

Keywords: winds, storms, weathering, destruction, erosion, materials, Earth's surface, historical structures, impact

Procedia PDF Downloads 41
5299 Content Analysis of ‘Junk Food’ Content in Children’s TV Programmes: A Comparison of UK Broadcast TV and Video-On-Demand Services

Authors: Shreesh Sinha, Alexander B. Barker, Megan Parkin, Emma Wilson, Rachael L. Murray

Abstract:

Background and Objectives: Exposure to HFSS imagery is associated with the consumption of foods high in fat, sugar or salt (HFSS), and subsequently obesity, among young people. We report and compare the results of two content analyses, one of two popular terrestrial children's television channels in the UK and the other of a selection of children's programmes available on video-on-demand (VOD) streaming sites. Methods: Content analysis of three days' worth of programmes (including advertisements) on two popular children's television channels broadcast on UK television (CBeebies and Milkshake) as well as a sample of 40 highest-rated children's programmes available on the VOD platforms, Netflix and Amazon Prime, using 1-minute interval coding. Results: HFSS content was seen in 181 broadcasts (36%) and in 417 intervals (13%) on terrestrial television, 'Milkshake' had a significantly higher proportion of programmes/adverts which contained HFSS content than 'CBeebies'. In VOD platforms, HFSS content was seen in 82 episodes (72% of the total number of episodes), across 459 intervals (19% of the total number of intervals), with no significant difference in the proportion of programmes containing HFSS content between Netflix and Amazon Prime. Conclusions: This study demonstrates that HFSS content is common in both popular UK children's television channels and children's programmes on VOD services. Since previous research has shown that HFSS content in the media has an effect on HFSS consumption, children's television programmes broadcast either on TV or VOD services are likely to have an effect on HFSS consumption in children, and legislative opportunities to prevent this exposure are being missed.

Keywords: public health, junk food, children's TV, HFSS

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5298 Quantification of Effects of Structure-Soil-Structure Interactions on Urban Environment under Rayleigh Wave Loading

Authors: Neeraj Kumar, J. P. Narayan

Abstract:

The effects of multiple Structure-Soil-Structure Interactions (SSSI) on the seismic wave-field is generally disregarded by earthquake engineers, particularly the surface waves which cause more damage to buildings. Closely built high rise buildings exchange substantial seismic energy with each other and act as a full-coupled dynamic system. In this paper, SSI effects on the building responses and the free field motion due to a small city consisting 25- homogenous buildings blocks of 10-storey are quantified. The rocking and translational behavior of building under Rayleigh wave loading is studied for different dimensions of the building. The obtained dynamic parameters of buildings revealed a reduction in building roof drift with an increase in number of buildings ahead of the considered building. The strain developed by vertical component of Rayleigh may cause tension in structural components of building. A matching of fundamental frequency of building for the horizontal component of Rayleigh wave with that for vertically incident SV-wave is obtained. Further, the fundamental frequency of building for the vertical vibration is approximately twice to that for horizontal vibration. The city insulation has caused a reduction of amplitude of Rayleigh wave up to 19.3% and 21.6% in the horizontal and vertical components, respectively just outside the city. Further, the insulating effect of city was very large at fundamental frequency of buildings for both the horizontal and vertical components. Therefore, it is recommended to consider the insulating effects of city falling in the path of Rayleigh wave propagation in seismic hazard assessment for an area.

Keywords: structure-soil-structure interactions, Rayleigh wave propagation, finite difference simulation, dynamic response of buildings

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5297 Interface Engineering of Short- and Ultrashort Period W-Based Multilayers for Soft X-Rays

Authors: A. E. Yakshin, D. Ijpes, J. M. Sturm, I. A. Makhotkin, M. D. Ackermann

Abstract:

Applications like synchrotron optics, soft X-ray microscopy, X-ray astronomy, and wavelength dispersive X-ray fluorescence (WD-XRF) rely heavily on short- and ultra-short-period multilayer (ML) structures. In WD-XRF, ML serves as an analyzer crystal to disperse emission lines of light elements. The key requirement for the ML is to be highly reflective while also providing sufficient angular dispersion to resolve specific XRF lines. For these reasons, MLs with periods ranging from 1.0 to 2.5 nm are of great interest in this field. Due to the short period, the reflectance of such MLs is extremely sensitive to interface imperfections such as roughness and interdiffusion. Moreover, the thickness of the individual layers is only a few angstroms, which is close to the limit of materials to grow a continuous film. MLs with a period between 2.5 nm and 1.0 nm, combining tungsten (W) reflector with B₄C, Si, and Al spacers, were created and examined. These combinations show high theoretical reflectance in the full range from C-Kα (4.48nm) down to S-Kα (0.54nm). However, the formation of optically unfavorable compounds, intermixing, and interface roughness result in limited reflectance. A variety of techniques, including diffusion barriers, seed layers, and ion polishing for sputter-deposited MLs, were used to address these issues. Diffuse scattering measurements, photo-electron spectroscopy analysis, and X-ray reflectivity measurements showed a noticeable reduction of compound formation, intermixing, and interface roughness. This also resulted in a substantial increase in soft X-ray reflectance for W/Si, W/B4C, and W/Al MLs. In particular, the reflectivity of 1 nm period W/Si multilayers at the wavelength of 0.84 nm increased more than 3-fold – propelling forward the applicability of such multilayers for shorter wavelengths.

Keywords: interface engineering, reflectance, short period multilayer structures, x-ray optics

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5296 Production, Characterisation and Assessment of Biomixture Fuels for Compression Ignition Engine Application

Authors: K. Masera, A. K. Hossain

Abstract:

Hardly any neat biodiesel satisfies the European EN14214 standard for compression ignition engine application. To satisfy the EN14214 standard, various additives are doped into biodiesel; however, biodiesel additives might cause other problems such as increase in the particular emission and increased specific fuel consumption. In addition, the additives could be expensive. Considering the increasing level of greenhouse gas GHG emissions and fossil fuel depletion, it is forecasted that the use of biodiesel will be higher in the near future. Hence, the negative aspects of the biodiesel additives will likely to gain much more importance and need to be replaced with better solutions. This study aims to satisfy the European standard EN14214 by blending the biodiesels derived from sustainable feedstocks. Waste Cooking Oil (WCO) and Animal Fat Oil (AFO) are two sustainable feedstocks in the EU (including the UK) for producing biodiesels. In the first stage of the study, these oils were transesterified separately and neat biodiesels (W100 & A100) were produced. Secondly, the biodiesels were blended together in various ratios: 80% WCO biodiesel and 20% AFO biodiesel (W80A20), 60% WCO biodiesel and 40% AFO biodiesel (W60A40), 50% WCO biodiesel and 50% AFO biodiesel (W50A50), 30% WCO biodiesel and 70% AFO biodiesel (W30A70), 10% WCO biodiesel and 90% AFO biodiesel (W10A90). The prepared samples were analysed using Thermo Scientific Trace 1300 Gas Chromatograph and ISQ LT Mass Spectrometer (GC-MS). The GS-MS analysis gave Fatty Acid Methyl Ester (FAME) breakdowns of the fuel samples. It was found that total saturation degree of the samples was linearly increasing (from 15% for W100 to 54% for A100) as the percentage of the AFO biodiesel was increased. Furthermore, it was found that WCO biodiesel was mainly (82%) composed of polyunsaturated FAMEs. Cetane numbers, iodine numbers, calorific values, lower heating values and the densities (at 15 oC) of the samples were estimated by using the mass percentages data of the FAMEs. Besides, kinematic viscosities (at 40 °C and 20 °C), densities (at 15 °C), heating values and flash point temperatures of the biomixture samples were measured in the lab. It was found that estimated and measured characterisation results were comparable. The current study concluded that biomixture fuel samples W60A40 and W50A50 were perfectly satisfying the European EN 14214 norms without any need of additives. Investigation on engine performance, exhaust emission and combustion characteristics will be conducted to assess the full feasibility of the proposed biomixture fuels.

Keywords: biodiesel, blending, characterisation, CI engine

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5295 Effects of Lower and Upper Body Plyometric Training on Electrocardiogram Parameters of University Athletes

Authors: T. N. Uzor, C. O. Akosile, G. O. Emeahara

Abstract:

Plyometric training is a form of specialised strength training that uses fast muscular contractions to improve power and speed in sports conditioning by coaches and athletes. Despite its useful role in sports conditioning programme, the information about plyometric training on the athletes cardiovascular health especially Electrocardiogram (ECG) has not been established in the literature. The purpose of the study was to determine the effects of lower and upper body plyometric training on ECG of athletes. The study was guided by three null hypotheses. Quasi–experimental research design was adopted for the study. Seventy-two university male athletes constituted the population of the study. Thirty male athletes aged 18 to 24 years volunteered to participate in the study, but only twenty-three completed the study. The volunteered athletes were apparently healthy, physically active and free of any lower and upper extremity bone injuries for past one year and they had no medical or orthopedic injuries that may affect their participation in the study. Ten subjects were purposively assigned to one of the three groups: lower body plyometric training (LBPT), upper body plyometric training (UBPT), and control (C). Training consisted of six plyometric exercises: lower (ankle hops, squat jumps, tuck jumps) and upper body plyometric training (push-ups, medicine ball-chest throws and side throws) with moderate intensity. The general data were collated and analysed using Statistical Package for Social Science (SPSS version 22.0). The research questions were answered using mean and standard deviation, while paired samples t-test was also used to test for the hypotheses. The results revealed that athletes who were trained using LBPT had reduced ECG parameters better than those in the control group. The results also revealed that athletes who were trained using both LBPT and UBPT indicated lack of significant differences following ten weeks plyometric training than those in the control group in the ECG parameters except in Q wave, R wave and S wave (QRS) complex. Based on the findings of the study, it was recommended among others that coaches should include both LBPT and UBPT as part of athletes’ overall training programme from primary to tertiary institution to optimise performance as well as reduce the risk of cardiovascular diseases and promotes good healthy lifestyle.

Keywords: concentric, eccentric, electrocardiogram, plyometric

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5294 The Test of Memory Malingering and Offence Severity

Authors: Kenji Gwee

Abstract:

In Singapore, the death penalty remains in active use for murder and drug trafficking of controlled drugs such as heroin. As such, the psychological assessment of defendants can often be of high stakes. The Test of Memory Malingering (TOMM) is employed by government psychologists to determine the degree of effort invested by defendants, which in turn inform on the veracity of overall psychological findings that can invariably determine the life and death of defendants. The purpose of this study was to find out if defendants facing the death penalty were more likely to invest less effort during psychological assessment (to fake bad in hopes of escaping the death sentence) compared to defendants facing lesser penalties. An archival search of all forensic cases assessed in 2012-2013 by Singapore’s designated forensic psychiatric facility yielded 186 defendants’ TOMM scores. Offence severity, coded into 6 rank-ordered categories, was analyzed in a one-way ANOVA with TOMM score as the dependent variable. There was a statistically significant difference (F(5,87) = 2.473, p = 0.038). A Tukey post-hoc test with Bonferroni correction revealed that defendants facing lower charges (Theft, shoplifting, criminal breach of trust) invested less test-taking effort (TOMM = 37.4±12.3, p = 0.033) compared to those facing the death penalty (TOMM = 46.2±8.1). The surprising finding that those facing death penalties actually invested more test taking effort than those facing relatively minor charges could be due to higher levels of cooperation when faced with death. Alternatively, other legal avenues to escape the death sentence may have been preferred over the mitigatory chance of a psychiatric defence.

Keywords: capital sentencing, offence severity, Singapore, Test of Memory Malingering

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5293 Towards Law Data Labelling Using Topic Modelling

Authors: Daniel Pinheiro Da Silva Junior, Aline Paes, Daniel De Oliveira, Christiano Lacerda Ghuerren, Marcio Duran

Abstract:

The Courts of Accounts are institutions responsible for overseeing and point out irregularities of Public Administration expenses. They have a high demand for processes to be analyzed, whose decisions must be grounded on severity laws. Despite the existing large amount of processes, there are several cases reporting similar subjects. Thus, previous decisions on already analyzed processes can be a precedent for current processes that refer to similar topics. Identifying similar topics is an open, yet essential task for identifying similarities between several processes. Since the actual amount of topics is considerably large, it is tedious and error-prone to identify topics using a pure manual approach. This paper presents a tool based on Machine Learning and Natural Language Processing to assists in building a labeled dataset. The tool relies on Topic Modelling with Latent Dirichlet Allocation to find the topics underlying a document followed by Jensen Shannon distance metric to generate a probability of similarity between documents pairs. Furthermore, in a case study with a corpus of decisions of the Rio de Janeiro State Court of Accounts, it was noted that data pre-processing plays an essential role in modeling relevant topics. Also, the combination of topic modeling and a calculated distance metric over document represented among generated topics has been proved useful in helping to construct a labeled base of similar and non-similar document pairs.

Keywords: courts of accounts, data labelling, document similarity, topic modeling

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5292 Usability Testing on Information Design through Single-Lens Wearable Device

Authors: Jae-Hyun Choi, Sung-Soo Bae, Sangyoung Yoon, Hong-Ku Yun, Jiyoung Kwahk

Abstract:

This study was conducted to investigate the effect of ocular dominance on recognition performance using a single-lens smart display designed for cycling. A total of 36 bicycle riders who have been cycling consistently were recruited and participated in the experiment. The participants were asked to perform tasks riding a bicycle on a stationary stand for safety reasons. Independent variables of interest include ocular dominance, bike usage, age group, and information layout. Recognition time (i.e., the time required to identify specific information measured with an eye-tracker), error rate (i.e. false answer or failure to identify the information in 5 seconds), and user preference scores were measured and statistical tests were conducted to identify significant results. Recognition time and error ratio showed significant difference by ocular dominance factor, while the preference score did not. Recognition time was faster when the single-lens see-through display on the dominant eye (average 1.12sec) than on the non-dominant eye (average 1.38sec). Error ratio of the information recognition task was significantly lower when the see-through display was worn on the dominant eye (average 4.86%) than on the non-dominant eye (average 14.04%). The interaction effect of ocular dominance and age group was significant with respect to recognition time and error ratio. The recognition time of the users in their 40s was significantly longer than the other age groups when the display was placed on the non-dominant eye, while no difference was observed on the dominant eye. Error ratio also showed the same pattern. Although no difference was observed for the main effect of ocular dominance and bike usage, the interaction effect between the two variables was significant with respect to preference score. Preference score of daily bike users was higher when the display was placed on the dominant eye, whereas participants who use bikes for leisure purposes showed the opposite preference patterns. It was found more effective and efficient to wear a see-through display on the dominant eye than on the non-dominant eye, although user preference was not affected by ocular dominance. It is recommended to wear a see-through display on the dominant eye since it is safer by helping the user recognize the presented information faster and more accurately, even if the user may not notice the difference.

Keywords: eye tracking, information recognition, ocular dominance, smart headware, wearable device

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5291 Seroprevalence and Associated Factors of Hepatitis B and Hepatitis C Viral Infections Among Prisoners in Tigray, Northern Ethiopia

Authors: Belaynesh Tsegay, Teklay Gebrecherkos, Atsebaha Gebrekidan Kahsay, Mahmud Abdulkader

Abstract:

Background: Hepatitis B and C viruses are important health and socioeconomic problem across the globe, with a remarkable number of diseases and deaths in sub-Saharan African countries. The burden of hepatitis is unknown in the prison settings of Tigray. Therefore, we aimed to describe the seroprevalence and associated factors of hepatitis B and C viruses among prisoners in Tigray, Ethiopia. Methods: A cross-sectional study was carried out from February 2020 to May 2020 at the prison facilities of Tigray. Demographics and associated factors were collected from 315 prisoners prospectively. Five milliliters of blood were collected and tested using rapid tests kits of HBsAg (Zhejiang orient Gene Biotech Co., Ltd., China) and HCV antibodies (Volkan Kozmetik Sanayi Ve Ticaret Ltd. STI, Turkey). Positive samples were confirmed using ELISA (Beijing Wantai Biological Pharmacy Enterprise Co. Ltd). Data were analyzed using the SPSS version 20, and p<0.05 was considered statistically significant. Results: The overall seroprevalence of HBV and HCV were 25 (7.9%) and 1 (0.3%), respectively. The majority of hepatitis B viral infections were identified from the age groups of 18–25 years (10.7%) and unmarried prisoners (11.8%). Prisoners greater than 100 per cell (AOR=3.95, 95% CI=1.15–13.6, p=0.029) and with a history of alcohol consumption (AOR=3.01, 95% CI=1.17–7.74, p=0.022) were significantly associated with HBV infections. Conclusion: The seroprevalence of HBV among prisoners was nearly high or borderline, with a very low HCV prevalence. HBV was most prevalent among young adults, those housed with a large number of prisoners per cell, and those who had a history of alcohol consumption. This study recommends that there should be prison-focused intervention, including regular health education, with the emphasis on the mode of transmission and introducing HBV screening policy for prisoners, especially when they enter the prison.

Keywords: seroprevalence, HBV, HCV, prisoners, tigray

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5290 Carbonation of Wollastonite (001) competing Hydration: Microscopic Insights from Ion Spectroscopy and Density Functional Theory

Authors: Peter Thissen

Abstract:

In this work, we report about the influence of the chemical potential of water on the carbonation reaction of wollastonite (CaSiO3) as model surface of cement and concrete. Total energy calculations based on density functional theory (DFT) combined with kinetic barrier predictions based on nudge elastic band (NEB) method show that the exposure of the water-free wollastonite surface to CO2 results in a barrier-less carbonation. CO2 reacts with the surface oxygen and forms carbonate (CO32-) complexes together with a major reconstruction of the surface. The reaction comes to a standstill after one carbonate monolayer has been formed. In case one water monolayer is covering the wollastonite surface, the carbonation is no more barrier-less, yet ending in a localized monolayer. Covered with multilayers of water, the thermodynamic ground state of the wollastonite completely changes due to a metal-proton exchange reaction (MPER, also called early stage hydration) and Ca2+ ions are partially removed from solid phase into the H2O/wollastonite interface. Mobile Ca2+ react again with CO2 and form carbonate complexes, ending in a delocalized layer. By means of high resolution time-of-flight secondary-ion mass-spectroscopy images (ToF-SIMS), we confirm that hydration can lead to a partially delocalization of Ca2+ ions on wollastonite surfaces. Finally, we evaluate the impact of our model surface results by means of Low Energy Ion Scattering (LEIS) spectroscopy combined with careful discussion about the competing reactions of carbonation vs. hydration.

Keywords: Calcium-silicate, carbonation, hydration, metal-proton exchange reaction

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5289 Luminescent and Conductive Cathode Buffer Layer for Enhanced Power Conversion Efficiency of Bulk-Heterojunction Solar Cells

Authors: Swati Bishnoi, D. Haranath, Vinay Gupta

Abstract:

In this work, we demonstrate that the power conversion efficiency (PCE) of organic solar cells (OSCs) could be improved significantly by using ZnO doped with Aluminum (Al) and Europium (Eu) as cathode buffer layer (CBL). The ZnO:Al,Eu nanoparticle layer has broadband absorption in the ultraviolet (300-400 nm) region. The Al doping contributes to the enhancement in the conductivity whereas Eu doping significantly improves emission in the visible region. Moreover, this emission overlaps with the absorption range of polymer poly [N -9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′- benzothiadiazole)] (PCDTBT) significantly and results in an enhanced absorption by the active layer and hence high photocurrent. An increase in the power conversion efficiency (PCE) of 6.8% has been obtained for ZnO: Al,Eu CBL as compared to 5.9% for pristine ZnO, in the inverted device configuration ITO/CBL/active layer/MoOx/Al. The active layer comprises of a blend of PCDTBT donor and [6-6]-phenyl C71 butyric acid methyl ester (PC71BM) acceptor. In the reference device pristine ZnO has been used as CBL, whereas in the other one ZnO:Al,Eu has been used as CBL. The role of the luminescent CBL layer is to down-shift the UV light into visible range which overlaps with the absorption of PCDTBT polymer, resulting in an energy transfer from ZnO:Al,Eu to PCDTBT polymer and the absorption by active layer is enhanced as revealed by transient spectroscopy. This enhancement resulted in an increase in the short circuit current which contributes in an increased PCE in the device employing ZnO: Al,Eu CBL. Thus, the luminescent ZnO: Al, Eu nanoparticle CBL has great potential in organic solar cells.

Keywords: cathode buffer layer, energy transfer, organic solar cell, power conversion efficiency

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5288 The Consequences of COVID-19 Crisis on Informal Workers in Brazil: An Analysis of Emergency Aid from the Government

Authors: Michele Romanello

Abstract:

COVID-19 has spread rapidly in Brazil since March 2020, making the country one of the most affected in the world by the pandemic. From an economic point of view, Brazil came from a pre-pandemic period characterized by low or negative growth, with a resulting increase in the number of unemployed and informal workers. This paper considers lockdown implementation in the situation of the large presence of informality in the economy. The objective of the paper is to analyze how the country has tried to help workers affected by economic crisis after the implementation of measures against COVID-19 and whether the emergency assistance from the government has been adequate to contain the increase of informal workers and unemployed. The methodology used in this paper is survival analysis. Through this methodology, the formality – informality, and informality – unemployment transitions are analyzed. This analysis draws data from the Continuous National Household Sample Survey (Continuous PNAD) and from the National Household Sample Survey COVID-19 (PNAD COVID-19) covering the period of January 2020 – July 2020. The results indicate that emergency aid has been not sufficient to reduce the transitions of workers from formal to informal jobs and from informal jobs to unemployment. Emergency aid has been not sufficient considering the previous situation of the country, with levels of poverty and inequality very high. In the next months, another fundamental determinant of the income trajectory in the context of the COVID-19 crisis will be the continuity of the emergency aid, especially considering the fiscal adjustment policy pursued by the government. Therefore, the current negative portrait may be even worse in the coming months.

Keywords: Brazil, COVID-19, informality, survival analysis

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5287 Development of Hierarchically Structured Tablets with 3D Printed Inclusions for Controlled Drug Release

Authors: Veronika Lesáková, Silvia Slezáková, František Štěpánek

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Drug dosage forms consisting of multi-unit particle systems (MUPS) for modified drug release provide a promising route for overcoming the limitation of conventional tablets. Despite the conventional use of pellets as units for MUP systems, 3D printed polymers loaded with a drug seem like an interesting candidate due to the control over dosing that 3D printing mechanisms offer. Further, 3D printing offers high flexibility and control over the spatial structuring of a printed object. The final MUPS tablets include PVP and HPC as granulate with other excipients, enabling the compaction process of this mixture with 3D printed inclusions, also termed minitablets. In this study, we have developed the multi-step production process for MUPS tablets, including the 3D printing technology. The MUPS tablets with incorporated 3D printed minitablets are a complex system for drug delivery, providing modified drug release. Such structured tablets promise to reduce drug fluctuations in blood, risk of local toxicity, and increase bioavailability, resulting in an improved therapeutic effect due to the fast transfer into the small intestine, where particles are evenly distributed. Drug loaded 3D printed minitablets were compacted into the excipient mixture, influencing drug release through varying parameters, such as minitablets size, matrix composition, and compaction parameters. Further, the mechanical properties and morphology of the final MUPS tablets were analyzed as many properties, such as plasticity and elasticity, can significantly influence the dissolution profile of the drug.

Keywords: 3D printing, dissolution kinetics, drug delivery, hot-melt extrusion

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5286 Effects of the Tomato Pomace Oil Extract on Physical and Antioxidant Properties of Gelatin Films

Authors: N. Jirukkakul, J. Sodtipinta

Abstract:

Tomatoes are widely consumed as fresh and processed products through the manufacturing industry. Therefore, tomato pomace is generated as a by-product accounting for about 5-13% of the whole tomato. Antioxidants still remain in tomato pomace and extraction of tomato oil may useful in edible film production. The edible film solution was prepared by mixing gelatin (2, 4 and 6%) with the distilled water and heating at 40oC for 30 min. Effect of tomato pomace oil was evaluated at 0, 0.5 and 1%. Film solution was poured in plate and dried overnight at 40oC before determining the physical properties, which are tensile strength, moisture content, color, solubility, and swelling power. The results showed that an increase gelatin concentration caused increasing of tensile strength, moisture content, solubility and swelling power. The edible film with tomato pomace oil extract appeared as the rough film with oil droplet dispersion. The addition of tomato pomace oil extract caused an increase in lightness, redness and yellowness, while tensile strength, moisture content, and solubility were decreased. Film with tomato pomace oil extract at 0.5 and 1% exhibited antioxidant properties but those properties were not significantly different (p<0.05) between film incorporated with tomato pomace oil extract 0.5 and 1%. The suitable condition for film production in this study, 4% of gelatin and 0.5% of tomato pomace oil extract, was selected for protecting oxidation of palm oil. At 15 days of the storage period, the palm oil which covered by gelatin film with tomato pomace oil extract had 22.45 milliequivalents/kg of peroxide value (PV), while, the palm oil which covered by polypropylene film and control had 24.79 and 26.67 milliequivalents/kg, respectively. Therefore, incorporation of tomato pomace oil extract in gelatin film was able to protect the oxidation of food products with high fat content.

Keywords: antioxidant, gelatin films, physical properties, tomato oil extract

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5285 Electron-Ion Recombination for Photoionized and Collisionally Ionized Plasmas

Authors: Shahin A. Abdel-Naby, Asad T. Hassan

Abstract:

Astrophysical plasma environments can be classified into collisionally ionized (CP) and photoionizedplasmas (PP). In the PP, ionization is caused by an external radiation field, while it is caused by electron collision in the CP. Accurate and reliable laboratory astrophysical data for electron-ion recombination is needed for plasma modeling for low and high-temperatures. Dielectronic recombination (DR) is the dominant recombination process for the CP for most of the ions. When a free electron is captured by an ion with simultaneous excitation of its core, a doubly-exited intermediate state may be formed. The doubly excited state relaxes either by electron emission (autoionization) or by radiative decay (photon emission). DR process takes place when the relaxation occurs to a bound state by a photon emission. DR calculations at low-temperatures are problematic and challenging since small uncertaintiesin the low-energy DR resonance positions can produce huge uncertainties in DR rate coefficients.DR rate coefficients for N²⁺ and O³⁺ ions are calculated using state-of-the-art multi-configurationBreit-Pauli atomic structure AUTOSTRUCTURE collisional package within the generalized collisional-radiative framework. Level-resolved calculations for RR and DR rate coefficients from the ground and metastable initial states are produced in an intermediate coupling scheme associated withn = 0 and n = 1 core-excitations. DR cross sections for these ions are convoluted with the experimental electron-cooler temperatures to produce DR rate coefficients. Good agreements are foundbetween these rate coefficients and theexperimental measurements performed at CRYRING heavy-ionstorage ring for both ions.

Keywords: atomic data, atomic process, electron-ion collision, plasmas

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5284 Determines of Professional Competencies among Newly Registered Nurses in Teaching Hospital in Kingdom of Saudi Arabia

Authors: Rana Alkattan

Abstract:

Aim: This study aims to identify and analyze the factors predicting the professional clinical competency among newly recruited registered nurses. In addition, it aims to explore factors significantly correlated with high and low professional clinical competency score. Method: A descriptive analytical is applied in this study, cross-sectional which conducted between June 2012 and June 2013 at King Abdulaziz University Hospital, as one of the largest governmental university tertiary Hospital in Saudi Arabia. A survey questionnaire was designed to collect data. And then, data were analyzed using the SPSS. Results: A total of the 86 nurses provided valid responses. 69 were female and 17 were male. The majority of the participants in this study were married, from the Philippines, between 20-29 years old. The majority had certified university bachelor’s degree in nursing, as well as had prior experience in nursing between 1 to 5 years. There are two categories emerged from the data, which significantly correlated with nurses' professional competence and development. The first was the newly employed registered nurses demographic characteristic (correlation coefficients 0.154 to 0.470, P < 0.05), while the second was the list of studied environmental factors except 'job rotation factor' (correlation coefficients 0.122 to 0.540, P < 0.01). However, nurses' attitude including motivation and confidence were not associated with nurse's professional competency. Conclusion: that nurses' professional competence development is a process affected by certain personal demographic and environmental factors which will enable newly graduates nurses to provide safe effective patients' care and maintain their career responsibilities.

Keywords: clinical, competence, development nurses professional, registered

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5283 Genomic Identification of Anisakis Simplex Larvae by PCR-RAPD

Authors: Fumiko Kojima, Shuji Fujimoto

Abstract:

Anisakiasis is a disease caused by infection with an anisakid larvae, mostly Anisakis simplex. The larvae commonly infect in marine fish and the disease is frequently reported in areas of the world where fish is consumed raw, lightly pickled or salted. In Japan, people have the habit of eating raw fish such as ‘sushi’ or ‘sashimi’, so they have more chance of infection with larvae of anisakid nematodes. There are three sibling species in A. simplex larvae, namely, A. simplex sensu stricto (Asss), A. pegreffii (Ap) and A. simplex C. It was revealed that Ap is dominant among the larvae from fish (Scomber japonics) in the Japan Sea side and Asss is dominant among those of the Pacific Ocean side conversely. Although anisakiasis has happened in Japan among both the Japan Sea side area and the Pacific Ocean side area. The aim of this study was to investigate genetic variations between the siblings (Asss and Ap) and within the same sibling species by random amplified polymorphic DNA (RAPD) technique. In order to investigate the genetic difference among the each A. simplex larvae, we used RAPD technique to differentiate individuals of A. simplex obtained from Scomber japonics fish those were caught in the Japan sea (Goto Islands in Nagasaki Prefecture) and the cost of Pacific Ocean (Kanagawa Prefecture). The RAPD patterns of the control DNA (Genus Raphidascaris) were markedly different from those of the A. simplex. There were differences in amplification patterns between Asss and Ap. The RAPD patterns for larvae obtained from fish of the same sea were somewhat different and variations were detected even among larvae from the same fish. These results suggest the considerable high genetic variability between Asss and Ap and the possible existence of genetic variation within the sibling species.

Keywords: Anisakiasis in Japan, Anisakis simplex, genomic identification, PCR-RAPD

Procedia PDF Downloads 165
5282 Determining the Factors Affecting Social Media Addiction (Virtual Tolerance, Virtual Communication), Phubbing, and Perception of Addiction in Nurses

Authors: Fatima Zehra Allahverdi, Nukhet Bayer

Abstract:

Objective: Three questions were formulated to examine stressful working units (intensive care units, emergency unit nurses) utilizing the self-perception theory and social support theory. This study provides a distinctive input by inspecting the combination of variables regarding stressful working environments. Method: The descriptive research was conducted with the participation of 400 nurses working at Ankara City Hospital. The study used Multivariate Analysis of Variance (MANOVA), regression analysis, and a mediation model. Hypothesis one used MANOVA followed by a Scheffe post hoc test. Hypothesis two utilized regression analysis using a hierarchical linear regression model. Hypothesis three used a mediation model. Result: The study utilized mediation analyses. Findings supported the hypotheses that intensive care units have significantly high scores in virtual communication and virtual tolerance. The number of years on the job, virtual communication, virtual tolerance, and phubbing significantly predicted 51% of the variance of perception of addiction. Interestingly, the number of years on the job, while significant, was negatively related to perception of addiction. Conclusion: The reasoning behind these findings and the lack of significance in the emergency unit is discussed. Around 7% of the variance of phubbing was accounted for through working in intensive care units. The model accounted for 26.80 % of the differences in the perception of addiction.

Keywords: phubbing, social media, working units, years on the job, stress

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5281 Characterisation of Human Attitudes in Software Requirements Elicitation

Authors: Mauro Callejas-Cuervo, Andrea C. Alarcon-Aldana

Abstract:

It is evident that there has been progress in the development and innovation of tools, techniques and methods in the development of software. Even so, there are few methodologies that include the human factor from the point of view of motivation, emotions and impact on the work environment; aspects that, when mishandled or not taken into consideration, increase the iterations in the requirements elicitation phase. This generates a broad number of changes in the characteristics of the system during its developmental process and an overinvestment of resources to obtain a final product that, often, does not live up to the expectations and needs of the client. The human factors such as emotions or personality traits are naturally associated with the process of developing software. However, most of these jobs are oriented towards the analysis of the final users of the software and do not take into consideration the emotions and motivations of the members of the development team. Given that in the industry, the strategies to select the requirements engineers and/or the analysts do not take said factors into account, it is important to identify and describe the characteristics or personality traits in order to elicit requirements effectively. This research describes the main personality traits associated with the requirements elicitation tasks through the analysis of the existing literature on the topic and a compilation of our experiences as software development project managers in the academic and productive sectors; allowing for the characterisation of a suitable profile for this job. Moreover, a psychometric test is used as an information gathering technique, and it is applied to the personnel of some local companies in the software development sector. Such information has become an important asset in order to make a comparative analysis between the degree of effectiveness in the way their software development teams are formed and the proposed profile. The results show that of the software development companies studied: 53.58% have selected the personnel for the task of requirements elicitation adequately, 37.71% possess some of the characteristics to perform the task, and 10.71% are inadequate. From the previous information, it is possible to conclude that 46.42% of the requirements engineers selected by the companies could perform other roles more adequately; a change which could improve the performance and competitiveness of the work team and, indirectly, the quality of the product developed. Likewise, the research allowed for the validation of the pertinence and usefulness of the psychometric instrument as well as the accuracy of the characteristics for the profile of requirements engineer proposed as a reference.

Keywords: emotions, human attitudes, personality traits, psychometric tests, requirements engineering

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5280 The Documentation of Modernisation Processes in Spain Based on the Residential Architecture of the 1960s. A Patrimonial Perspective on El Plantinar Neighbourhood in Seville

Authors: Julia Rey-Pérez, Julia Díaz Borrego

Abstract:

The modernisation process of the city of Sevilla in Spain and the transformation of the city took place through national and local government initiatives from the 1960s onwards. Part of these actions was the execution of numerous residential neighbourhoodsthat prepared Sevilla for the change of era. This process was possible thanks to the implementation of public policies that showed the imminent need for new architectural programmes, as well as for high-rise architecture built in reinforced concrete. However, very little is known to this day about the modernisation process in Sevilla and the development of these neighbourhoods, which were designed to house a large number of people and are today a key reference point in the Historic Urban Landscape of the city of Seville. Therefore, the present research aims to learn and reflect upon the urban transformation of the city at this time andto deepen the heritage uniqueness of these neighbourhoods, as is the case of ElPlantinarneighbourhood.The methodology proposed for this research is structured in three phases, where in the first stage, a general study of the El Plantinarneighbourhood was carried out on three scales: urban, object-typological and perceptive. In the second stage, the cultural attributes and values of the urban complex in question were identified in order to determine whether the case study is truly representative of the beginnings of modernity in Spain and whether it needs a heritage approach. Finally, a third phase is proposed in which criteria will be defined on how to intervene in this neighbourhood to guarantee its presence in the urban landscape of the city of Seville. The expected results will help to understand the process of modernisation that the city has undergone, as well as the heritage value of this architecture in the construction of the collective memory.

Keywords: modern heritage, urban obsolescence, methodology, develop

Procedia PDF Downloads 129
5279 Incidence, Risk Factors and Impact of Major Adverse Events Following Paediatric Cardiac Surgery

Authors: Sandipika Gupta

Abstract:

Objective: Due to admirably low 30-day mortality rates for paediatric cardiac surgery, it is now pertinent to turn towards more intermediate-length outcomes such as morbidities closely associated with these surgeries. One such morbidity, major adverse events (MAE) comprises a group of adverse outcomes associated with paediatric cardiac surgery (e.g. cardiac arrest, major haemorrhage). Methods: This is a retrospective study that analysed the incidence and impact of MAE which was the primary outcome in the UK population. The data was collected in 5 centres between October 2015 and June 2017, amassing 3090 surgical episodes. The incidence and risk factors for MAE, were assessed through descriptive statistical analyses and multivariate logistic regression. The secondary outcomes of life status at 6 months and the length of hospital stay were also evaluated to understand the impact of MAE on patients. Results: Out of 3090 episodes, 134 (4.3%) had a postoperative MAE. The majority of the episodes were in: neonates (47%, P<0.001), high-risk cardiac diagnosis groups (20.1%, P<0.001), episodes with longer 5mes on the bypass (72.4%, P<0.001) and urgent surgeries (57.9%, P<0.001). Episodes reporting MAE also reported longer lengths of stay in hospital (29 days vs 9 days, P<0.001). Furthermore, patients experiencing MAE were at a higher risk of mortality at the 6-month life status check (mortality rates: 29.2% vs 2%, P<0.001).Conclusions: Key risk factors were identified. An important negative impact of MAE was found for patients. The identified risk factors could be used to profile and flag at-risk patients. Monitoring of MAE rates and closer investigation into the care pathway before and after individual MAEs in children’s heart units may lead to a reduction in these terrible events.

Keywords:

Procedia PDF Downloads 217
5278 Development of IDF Curves for Precipitation in Western Watershed of Guwahati, Assam

Authors: Rajarshi Sharma, Rashidul Alam, Visavino Seleyi, Yuvila Sangtam

Abstract:

The Intensity-Duration-Frequency (IDF) relationship of rainfall amounts is one of the most commonly used tools in water resources engineering for planning, design and operation of water resources project, or for various engineering projects against design floods. The establishment of such relationships was reported as early as in 1932 (Bernard). Since then many sets of relationships have been constructed for several parts of the globe. The objective of this research is to derive IDF relationship of rainfall for western watershed of Guwahati, Assam. These relationships are useful in the design of urban drainage works, e.g. storm sewers, culverts and other hydraulic structures. In the study, rainfall depth for 10 years viz. 2001 to 2010 has been collected from the Regional Meteorological Centre Borjhar, Guwahati. Firstly, the data has been used to construct the mass curve for duration of more than 7 hours rainfall to calculate the maximum intensity and to form the intensity duration curves. Gumbel’s frequency analysis technique has been used to calculate the probable maximum rainfall intensities for a period of 2 yr, 5 yr, 10 yr, 50 yr, 100 yr from the maximum intensity. Finally, regression analysis has been used to develop the intensity-duration-frequency (IDF) curve. Thus, from the analysis the values for the constants ‘a’,‘b’ &‘c’ have been found out. The values of ‘a’ for which the sum of the squared deviation is minimum has been found out to be 40 and when the corresponding value of ‘c’ and ‘b’ for the minimum squared deviation of ‘a’ are 0.744 and 1981.527 respectively. The results obtained showed that in all the cases the correlation coefficient is very high indicating the goodness of fit of the formulae to estimate IDF curves in the region of interest.

Keywords: intensity-duration-frequency relationship, mass curve, regression analysis, correlation coefficient

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5277 Evaluation of the Dry Compressive Strength of Refractory Bricks Developed from Local Kaolin

Authors: Olanrewaju Rotimi Bodede, Akinlabi Oyetunji

Abstract:

Modeling the dry compressive strength of sodium silicate bonded kaolin refractory bricks was studied. The materials used for this research work included refractory clay obtained from Ijero-Ekiti kaolin deposit on coordinates 7º 49´N and 5º 5´E, sodium silicate obtained from the open market in Lagos on coordinates 6°27′11″N 3°23′45″E all in the South Western part of Nigeria. The mineralogical composition of the kaolin clay was determined using the Energy Dispersive X-Ray Fluorescence Spectrometer (ED-XRF). The clay samples were crushed and sieved using the laboratory pulveriser, ball mill and sieve shaker respectively to obtain 100 μm diameter particles. Manual pipe extruder of dimension 30 mm diameter by 43.30 mm height was used to prepare the samples with varying percentage volume of sodium silicate 5 %, 7.5 % 10 %, 12.5 %, 15 %, 17.5 %, 20% and 22.5 % while kaolin and water were kept at 50 % and 5 % respectively for the comprehensive test. The samples were left to dry in the open laboratory atmosphere for 24 hours to remove moisture. The samples were then were fired in an electrically powered muffle furnace. Firing was done at the following temperatures; 700ºC, 750ºC, 800ºC, 850ºC, 900ºC, 950ºC, 1000ºC and 1100ºC. Compressive strength test was carried out on the dried samples using a Testometric Universal Testing Machine (TUTM) equipped with a computer and printer, optimum compression of 4.41 kN/mm2 was obtained at 12.5 % sodium silicate; the experimental results were modeled with MATLAB and Origin packages using polynomial regression equations that predicted the estimated values for dry compressive strength and later validated with Pearson’s rank correlation coefficient, thereby obtaining a very high positive correlation value of 0.97.

Keywords: dry compressive strength, kaolin, modeling, sodium silicate

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5276 Impact of Lobular Carcinoma in situ on Local Recurrence in Breast Cancer Treated with Breast Conservation Therapy: A Systematic Review and Meta-Analysis

Authors: Christopher G. Harris, Guy D. Eslick

Abstract:

Purpose: Lobular carcinoma in situ (LCIS) is a known risk factor for breast cancer of unclear significance when detected in association with invasive carcinoma. This meta-analysis aims to determine the impact of LCIS on local recurrence risk for individuals with breast cancer treated with breast conservation therapy to help guide appropriate treatment strategies. Methods: We identified relevant studies from five electronic databases. Studies were deemed suitable for inclusion where they compared patients with invasive breast cancer and concurrent LCIS to those with breast cancer alone, all patients underwent breast conservation therapy (lumpectomy with adjuvant radiation therapy), and local recurrence was evaluated. Recurrence data were pooled by use of a random effects model. Results: From 1488 citations screened by our search, 8 studies were deemed suitable for inclusion. These studies comprised of 908 cases and 10638 controls. Median follow-up time was 90 months. There was a significantly increased overall risk of local breast cancer recurrence for individuals with LCIS in association with breast cancer following breast conservation therapy [pOR 1.87; 95% CI 1.14-3.04; p = 0.012]. The risk of local recurrence was non-significantly increased at 5 [pOR 1.09; 95% CI 0.48-2.48; p = 0.828] and 10 years [pOR 1.90; 95% CI 0.89-4.06; p = 0.096]. Conclusions: Individuals with LCIS in association with invasive breast cancer have an increased risk of local recurrence following breast conservation therapy. This supports consideration of aggressive local control of LCIS by way of completion mastectomy or re-excision for certain high-risk patients.

Keywords: breast cancer, breast conservation therapy, lobular carcinoma in situ, lobular neoplasia, local recurrence, meta-analysis

Procedia PDF Downloads 140
5275 The Effect of Occupational Calling and Social Support on the Anxiety of Navies Who Are Sent Overseas

Authors: Yonguk L. Park, Jeonghoon Seol

Abstract:

The Republic of Korea is facing a special situation as it is the only divided country in the world. Even though Korea is facing such unstable circumstances in terms of a foreign diplomacy situation, Korea is one of the countries who, in concern for world peace, have been sending troops overseas. The troops spend more than a year at sea and may suffer from different types of psychological disorders. The purpose of this study is to try to find factors that promote psychological well-being of troops and improve their psychological health. We investigated the effect of dispatch sailors’ occupational calling and social support on anxiety before they are sent overseas and also examined the interaction between occupational calling and social support on anxiety. One hundred thirty-eight dispatched sailors participated in this study, wherein they completed the Korean calling scale, multifaceted social support scale, and anxiety scale –Y form. We analyzed the data using hierarchical regression. The results showed that after controlling gender, marital status, and the previous experiences of dispatch, those who have a higher level of occupational calling and perceived social support experienced a low level of anxiety before they are sent (β = -.276, β = -.395). Furthermore, we examined the interaction effect. If the troops’ perceived social support is high, they experience a low level of anxiety—even if they have a low level of occupational calling. This study confirms that both occupational calling and social support reduce the level of anxiety of the troops. The research provides meaningful information in understanding those who serve in the Navy’s distinctive situations and contributes to improving their psychological well-being. We suggest that sailors undergo training to have a higher occupational calling and healthy relationships with friends, families, and co-workers who provide emotional and social support.

Keywords: navy, occupational calling, social support, anxiety

Procedia PDF Downloads 238
5274 High Prevalence of Canine Mammary Gland Tumor in Nulliparous Compared with Multiparous Female Dogs

Authors: Sudson Sirivaidyapong, Ratthanan Sathienbumrungkit, Nongnapas Ruangpet, Nattanun Uaprayoon, Chawisa Wejjakul

Abstract:

Many factors initiate mammary gland tumor in female dogs such as age, breed, sex, estrous cycle, birth control and pseudopregnancy. Those factors are mostly associated with canine sex hormone. In this study, questionnaires and direct interviews were used to collect information from owners of female dogs that had been diagnosed as mammary tumors at our veterinary teaching hospital, during January 2015 to October 2016 to compare the prevalence of mammary tumor between nulliparous and multiparous female dogs. 200 dogs (from all 212 mammary tumor patients, some were excluded because of inadequate information) were included in the study, 72.5% were nulliparous and 27.5% were multiparous. The results revealed that breed, age, birth control age and birth control methods were not different in both groups; most dogs in both groups were various purebreds, geriatric age, and low incidence of hormonal contraception while 100% of multiparous dogs and 83.7% of nulliparous dogs had been neutered at over two years old. The significant differences between two groups were the frequency of pseudopregnancy and estrus which were much higher in nulliparous female dogs. It can be concluded from our study that nulliparous dogs may be more likely at higher risk of mammary tumor compared to multiparous dogs from various factors especially, the frequency of estrus and the occurrence of pseudopregnancy which related to more times of sex hormonal contact. This study was a preliminary data for further studies to determine the other risk factors of mammary gland tumors in dogs, and to our knowledge, it is the first report on a significantly higher prevalence of mammary tumor in nulliparous female dogs than that in multiparous dogs. This finding corresponds with the study of breast cancer in women but may be from different causes and factors due to the differences in estrous physiology.

Keywords: canine, female dogs, nulliparous, multiparous, mammary tumor, prevalence

Procedia PDF Downloads 456
5273 Induced Pulsation Attack Against Kalman Filter Driven Brushless DC Motor Control System

Authors: Yuri Boiko, Iluju Kiringa, Tet Yeap

Abstract:

We use modeling and simulation tools, to introduce a novel bias injection attack, named the ’Induced Pulsation Attack’, which targets Cyber Physical Systems with closed-loop controlled Brushless DC (BLDC) motor and Kalman filter driver in the feedback loop. This attack involves engaging a linear function with a constant gradient to distort the coefficient of the injected bias, which falsifies the Kalman filter estimates of the rotor’s angular speed. As a result, this manipulation interaction inside the control system causes periodic pulsations in a form of asymmetric sine wave of both current and voltage in the circuit windings, with a high magnitude. It is shown that by varying the gradient of linear function, one can control both the frequency and structure of the induced pulsations. It is also demonstrated that terminating the attack at any point leads to additional compensating effort from the controller to restore the speed to its equilibrium value. This compensation effort produces an exponentially decaying wave, which we call the ’attack withdrawal syndrome’ wave. The conditions for maximizing or minimizing the impact of the attack withdrawal syndrome are determined. Linking the termination of the attack to the end of the full period of the induced pulsation wave has been shown to nullify the attack withdrawal syndrome wave, thereby improving the attack’s covertness.

Keywords: cyber-attack, induced pulsation, bias injection, Kalman filter, BLDC motor, control system, closed loop, P- controller, PID-controller, saw-function, cyber-physical system

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5272 Osteogenesis in Thermo-Sensitive Hydrogel Using Mesenchymal Stem Cell Derived from Human Turbinate

Authors: A. Reum Son, Jin Seon Kwon, Seung Hun Park, Hai Bang Lee, Moon Suk Kim

Abstract:

These days, stem cell therapy is focused on for promising source of treatment in clinical human disease. As a supporter of stem cells, in situ-forming hydrogels with growth factors and cells appear to be a promising approach in tissue engineering. To examine osteogenic differentiation of hTMSCs which is one of mesenchymal stem cells in vivo in an injectable hydrogel, we use a methoxy polyethylene glycol-polycaprolactone blockcopolymer (MPEG-PCL) solution with osteogenic factors. We synthesized MPEG-PCL hydrogel and measured viscosity to check sol-gel transition. In order to demonstrate osteogenic ability of hTMSCs, we conducted in vitro osteogenesis experiment. Then, to confirm the cell cytotoxicity, we performed WST-1 with hTMSCs and MPEG-PCL. As the result of in vitro experiment, we implanted cell and hydrogel mixture into animal model and checked degree of osteogenesis with histological analysis and amount of expression genes. Through these experimental data, MPEG-PCL hydrogel has sol-gel transition in temperature change and is biocompatible with stem cells. In histological analysis and gene expression, hTMSCs are very good source of osteogenesis with hydrogel and will use it to tissue engineering as important treatment method. hTMSCs could be a good adult stem cell source for usability of isolation and high proliferation. When hTMSCs are used as cell therapy method with in situ-formed hydrogel, they may provide various benefits like a noninvasive alternative for bone tissue engineering applications.

Keywords: injectable hydrogel, stem cell, osteogenic differentiation, tissue engineering

Procedia PDF Downloads 433