Search results for: atmospheric effects on muons
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 11272

Search results for: atmospheric effects on muons

10432 Receptor-Independent Effects of Endocannabinoid Anandamide on Contractility and Electrophysiological Properties of Rat Ventricular Myocytes

Authors: Lina T. Al Kury, Oleg I. Voitychuk, Ramiz M. Ali, Sehamuddin Galadari, Keun-Hang Susan Yang, Frank Christopher Howarth, Yaroslav M. Shuba, Murat Oz

Abstract:

A role for anandamide (N-arachidonoyl ethanolamide; AEA), a major endocannabinoid, in the cardiovascular system in various pathological conditions has been reported in earlier studies. In the present work, we have hypothesized that the antiarrhythmic effects reported for AEA are due to its negative inotropic effect and altered action potential (AP) characteristics. Therefore, we tested the effects of AEA on contractility and electrophysiological properties of rat ventricular myocytes. Video edge detection was used to measure myocyte shortening. Intracellular Ca2+ was measured in cells loaded with the fluorescent indicator fura-2 AM. Whole-cell patch-clamp technique was employed to investigate the effect of AEA on the characteristics of APs. AEA (1 μM) caused a significant decrease in the amplitudes of electrically-evoked myocyte shortening and Ca2+ transients and significantly decreased the duration of AP. The effect of AEA on myocyte shortening and AP characteristics was not altered in the presence of pertussis toxin (PTX, 2 µg/ml for 4 h), AM251 and SR141716 (cannabinoid type 1 receptor antagonists) or AM630 and SR 144528 (cannabinoid type 2 receptor antagonists). Furthermore, AEA inhibited voltage-activated inward Na+ (INa) and Ca2+ (IL,Ca) currents; major ionic currents shaping the APs in ventricular myocytes, in a voltage and PTX-independent manner. Collectively, the results suggest that AEA depresses ventricular myocyte contractility, by decreasing the action potential duration (APD), and inhibits the function of voltage-dependent Na+ and L-type Ca2+ channels in a manner independent of cannabinoid receptors. This mechanism may be importantly involved in the antiarrhythmic effects of anandamide.

Keywords: action potential, anandamide, cannabinoid receptor, endocannabinoid, ventricular myocytes

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10431 Numerical Investigation of the Effect of the Spark Plug Gap on Engine-Like Conditions

Authors: Fernanda Pinheiro Martins, Pedro Teixeira Lacava

Abstract:

The objective of this research is to analyze the effects of different spark plug conditions in engine-like conditions by applying computational fluid dynamics analysis. The 3D models applied consist of 3-Zones Extended Coherent Flame (ECFM-3Z) and Imposed Stretch Spark Ignition Model (ISSIM), respectively, for the combustion and the spark plug modelling. For this study, it was applied direct injection fuel system in a single cylinder engine operating with E0. The application of realistic operating conditions (load and speed) to the different cases studied will provide a deeper understanding of the effects of the spark plug gap, a result of parts outwearing in most of the cases, to the development of the combustion in engine-like conditions.

Keywords: engine, CFD, direct injection, combustion, spark plug

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10430 Endocrine Disruptors Effects on the 20-Hydroxyecdysone Concentration and the Vitellogenin Gene Expression in Gammarus sp.

Authors: Eric Gismondi, Aurelie Bigot-Clivot

Abstract:

Endocrine disruptors (EDCs) are well known to disrupt the development and the reproduction of exposed organisms. Although this point has been studied in vertebrate models, the limited knowledge of the endocrine system of invertebrates makes the evaluation of EDCs effects difficult. However, invertebrates represent the major part of aquatic ecosystems, such as amphipods Gammaridea, which are crucial for their functioning (e.g., litter degradation, food resource). Moreover, gammarids are hosts of parasites such as vertically-transmitted microsporidia (microsporidia VT), which could be confounding factors in assessment of EDC effects. Indeed, some microsporidia VT could have endocrine effects by their own present in the host since it was observed for example, a feminization of juvenile males, which become phenotypic females. This work evaluated the impact of ethinylestradiol (EE₂, estrogenic), cyproterone acetate (CPA, anti-androgenic), 4-hydroxytamoxifen (4HT, anti-estrogenic) and 17α-methyltestosterone (17MT - androgenic), on the 20-hydroxyecdysone concentration (i.e. 20HE - molt process) and the vitellogenin gene expression (i.e. reproduction) in the freshwater amphipod Gammarus pulex, after a 96h laboratory exposure. In addition, the presence of microsporidia VT was verified in order to analyze the effect of this confounding factor. Results of this study shown that, although endocrine systems of invertebrates and vertebrates are different, EDCs proved in vertebrates could also affect biological functions hormonally controlled in invertebrates. Indeed, the molt process of crustaceans was disrupted in the first stage (i.e. 20-HE concentration) and therefore, could affect, at the long term, the population dynamic. In addition, it was observed that G. pulex was differently impacted according to the gender and parasitism, which underline the importance to take into account these confounding factors to better evaluate the EDCs impact on invertebrate populations.

Keywords: endocrine disruption, gammarus sp., molt, parasitism

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10429 PM10 Prediction and Forecasting Using CART: A Case Study for Pleven, Bulgaria

Authors: Snezhana G. Gocheva-Ilieva, Maya P. Stoimenova

Abstract:

Ambient air pollution with fine particulate matter (PM10) is a systematic permanent problem in many countries around the world. The accumulation of a large number of measurements of both the PM10 concentrations and the accompanying atmospheric factors allow for their statistical modeling to detect dependencies and forecast future pollution. This study applies the classification and regression trees (CART) method for building and analyzing PM10 models. In the empirical study, average daily air data for the city of Pleven, Bulgaria for a period of 5 years are used. Predictors in the models are seven meteorological variables, time variables, as well as lagged PM10 variables and some lagged meteorological variables, delayed by 1 or 2 days with respect to the initial time series, respectively. The degree of influence of the predictors in the models is determined. The selected best CART models are used to forecast future PM10 concentrations for two days ahead after the last date in the modeling procedure and show very accurate results.

Keywords: cross-validation, decision tree, lagged variables, short-term forecasting

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10428 A Study on Selfie Culture, Social Media Engagement, Self-Image, and Young Adult Mental Well-being

Authors: Sumaiyya Ali, Humaira Jamshed

Abstract:

Selfie culture has become increasingly prevalent in recent years, with young adults being one of the most active demographics when it comes to taking and sharing selfies. While some argue that selfies can be a harmless way to express oneself, connect with others, and boost self-esteem, others have raised concerns about the potential negative effects of selfie culture on mental health. This study investigated the complex relationship between selfie culture, social media use, self-image, and mental well-being among young adults. A cross-sectional survey was conducted with over 75 participants aged 18–30. The results of the study showed that there is a positive relationship between selfie culture and social media use and that both of these factors are associated with lower self-esteem, higher self-consciousness, and increased appearance anxiety among young adults. Additionally, the study found that selfie culture was associated with increased narcissistic traits among young adults. The findings of this study suggest that selfie culture may have some negative effects on the mental health of young adults. However, it is important to note that the study was cross-sectional, which means that it cannot establish causality. Future research is needed to further investigate the relationship between selfie culture and mental health. In addition to the findings of the study, it is also important to consider the motivation behind selfie-taking. The study identified four main motivations for taking selfies: to communicate with others, to promote oneself, to express oneself, and to seek attention. It is likely that the negative effects of selfie culture are more pronounced for individuals who take selfies for narcissistic or attention-seeking reasons. Overall, the findings of this study suggest that selfie culture is a complex phenomenon with both positive and negative potential effects on the mental health of young adults. It is important to be aware of the potential risks associated with selfie culture, and to use it in a healthy and balanced way.

Keywords: selfie, social media, psychology, mental health

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10427 Effects of Increased Green Surface on a Densely Built Urban Fabric: The Case of Budapest

Authors: Viktória Sugár, Orsolya Frick, Gabriella Horváth, A. Bendegúz Vöröss, Péter Leczovics, Géza Baráth

Abstract:

Urban greenery has multiple positive effects both on the city and its residents. Apart from the visual advantages, it changes the micro-climate by cooling and shading, also increasing vapor and oxygen, reducing dust and carbon-dioxide content at the same time. The above are all critical factors of livability of an urban fabric. Unfortunately, in a dense, historical district there are restricted possibilities to build green surfaces. The present study collects and systemizes the applicable green solutions in the case of a historical downtown district of Budapest. The study contains a GIS-based measurement of the eligible surfaces for greenery, and also calculates the potential of oxygen production, carbon-dioxide reduction and cooling effect of an increased green surface.  It can be concluded that increasing the green surface has measurable effects on a densely built urban fabric, including air quality, micro-climate and other environmental factors.

Keywords: urban greenery, green roof, green wall, green surface potential, sustainable city, oxygen production, carbon-dioxide reduction, geographical information system

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10426 Sensitivity Parameter Analysis of Negative Moment Dynamic Load Allowance of Continuous T-Girder Bridge

Authors: Fan Yang, Ye-Lu Wang, Yang Zhao

Abstract:

The dynamic load allowance, as an application result of the vehicle-bridge coupled vibration theory, is an important parameter for bridge design and evaluation. Based on the coupled vehicle-bridge vibration theory, the current work establishes a full girder model of a dynamic load allowance, selects a planar five-degree-of-freedom three-axis vehicle model, solves the coupled vehicle-bridge dynamic response using the APDL language in the spatial finite element program ANSYS, selects the pivot point 2 sections as the representative of the negative moment section, and analyzes the effects of parameters such as travel speed, unevenness, vehicle frequency, span diameter, span number and forced displacement of the support on the negative moment dynamic load allowance through orthogonal tests. The influence of parameters such as vehicle speed, unevenness, vehicle frequency, span diameter, span number, and forced displacement of the support on the negative moment dynamic load allowance is analyzed by orthogonal tests, and the influence law of each influencing parameter is summarized. It is found that the effects of vehicle frequency, unevenness, and speed on the negative moment dynamic load allowance are significant, among which vehicle frequency has the greatest effect on the negative moment dynamic load allowance; the effects of span number and span diameter on the negative moment dynamic load allowance are relatively small; the effects of forced displacement of the support on the negative moment dynamic load allowance are negligible.

Keywords: continuous T-girder bridge, dynamic load allowance, sensitivity analysis, vehicle-bridge coupling

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10425 The Moderation Effect of Smart Phone Addiction in Relationship between Self-Leadership and Innovative Behavior

Authors: Gi-Ryun Park, Gye-Wan Moon, Dong-Hoon Yang

Abstract:

This study aims to explore the positive effects of self-leadership and innovative behavior that'd been proven in the existing researches proactively and understand the regulation effects of smartphone addiction which has recently become an issue in Korea. This study conducted a convenient sampling of college students attending the four colleges located at Daegu. A total of 210 questionnaires in 5-point Likert scale were distributed to college students. Among which, a total of 200 questionnaires were collected for our final analysis data. Both correlation analysis and regression analysis were carried out to verify those questionnaires through SPSS 20.0. As a result, college students' self-leadership had a significantly positive impact on innovative behavior (B= .210, P= .003). In addition, it is found that the relationship between self-leadership and innovative behavior can be adjusted depending on the degree of smartphone addiction in college students (B= .264, P= .000). This study could first understand the negative effects of smartphone addiction and find that if students' self-leadership is improved in terms of self-management and unnecessary use of smartphone is controlled properly, innovative behavior can be improved. In addition, this study is significant in that it attempts to identify a new impact of smartphone addiction with the recent environmental changes, unlike the existing researches that'd been carried out from the perspective of organizational behavior theory.

Keywords: innovative behavior, revolutionary behavior, self-leadership, smartphone addiction

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10424 Exploring The Effects of Immersive Virtual Reality on Increasing Willingness to Communicate, Oral Performance, and Reducing Speaking Anxiety for EFL Elementary Students from Taiwan

Authors: Yi-ju Ariel Wu

Abstract:

Exploring The Effects of Immersive Virtual Reality on Increasing Willingness to Communicate, Oral Performance, and Reducing Speaking Anxiety for EFL Elementary Students from Taiwan

Keywords: Immersive Virtual Reality, EFL speaking, situated learning, pragmatics

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10423 The Effect of Dementia on Family Members

Authors: Shakeela Ahmed, Nabanita Hazarika

Abstract:

The study aims to understand the effects of dementia on family members. The primary objectives of this research are to identify the main reasons for dementia among the elderly, understand the struggles and stigmas faced by the family members, and understand the effects of dementia on family members. The research employs a qualitative method and utilizes unstructured interviews with family members, counselors and caregivers. A descriptive research design is employed, and thematic analysis is used to analyze the data. A total of 17 family members in the age group of 54-69 years were interviewed, along with 2 counselors and 2 caretakers. In understanding dementia, the researcher has reviewed articles, and the studies revealed diverse meanings, symptoms, stages attached to dementia, and the complex interplay of protective and risk factors for dementia. However, in understanding dementia and its effects on families, there is a lack of studies in relation to the significant effects of dementia on family members and their role as primary caregivers. Therefore, an attempt has been made to understand the effects of dementia on family members, along with ways to improve dementia care for family members. The purpose of the study was to understand the effects and challenges of dementia on family members, the psychosocial reasons for dementia among the elderly, and the various struggles and stigmas faced by the family members of dementia patients. The major findings of the study indicate that people with dementia are cared for by family members at home. Dementia has a significant impact on family members. Family member's quality of life is affected; they experience feelings of anxiety, stress, irritation, frustration, and fear as they watch their loved ones struggle with dementia. They also experience financial strain, as dementia care, medication, and therapy are expensive. Another common impact is the role reversal of family members for their loved ones with dementia. There is a lack of awareness and social understanding about dementia, which leads to family members experiencing stigma and struggles. Caregivers are unable to take care of themselves, and many times, the primary caregiver, a spouse who is elderly, experiences acute stress and a physical inability to meet the demands of being a caregiver. Strategies to improve dementia care are understanding dementia, being patient with the person, showing love and care for the person, avoiding provoking the person, distracting them, offering reassurance, playing their favorite music, talking about things they love, going through old memories, following a structured routine, and remaining calm. The study has made an attempt to provide strategies to manage dementia care, understanding the struggles family members go through, and raising awareness about dementia that will enable further research and investigations.

Keywords: elderly, dementia, stigma, family members

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10422 Comparing the Experimental Thermal Conductivity Results Using Transient Methods

Authors: Sofia Mylona, Dale Hume

Abstract:

The main scope of this work is to compare the experimental thermal conductivity results of fluids between devices using transient techniques. A range of different liquids within a range of viscosities was measured with two or more devices, and the results were compared between the different methods and the reference equations wherever it was available. The liquids selected are the most commonly used in academic or industrial laboratories to calibrate their thermal conductivity instruments having a variety of thermal conductivity, viscosity, and density. Three transient methods (Transient Hot Wire, Transient Plane Source, and Transient Line Source) were compared for the thermal conductivity measurements taken by using them. These methods have been chosen as the most accurate and because they all follow the same idea; as a function of the logarithm of time, the thermal conductivity is calculated from the slope of a plot of sensor temperature rise. For all measurements, the selected temperature range was at the atmospheric level from 10 to 40 ° C. Our results are coming with an agreement with the objections of several scientists over the reliability of the results of a few popular devices. The observation was surprising that the device used in many laboratories for fast measurements of liquid thermal conductivity display deviations of 500 percent which can be very poorly reproduced.

Keywords: accurate data, liquids, thermal conductivity, transient methods.

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10421 The Effects of Soil Chemical Characteristics on Accumulation of Native Selenium by Zea mays Grains in Maize Belt in Kenya

Authors: S. B. Otieno, T. S. Jayne, M. Muyanga

Abstract:

Selenium which is an-antioxidant is important for human health enters food chain through crops. In Kenya Zea mays is consumed by 96% of population hence is a cheap and convenient method to provide selenium to large number of population. Several soil factors are known to have antagonistic effects on selenium speciation hence the uptake by Zea mays. No investigation in Kenya has been done to determine the effects of soil characteristics (pH, Tcarbon, CEC, Eh) affect accumulation of selenium in Zea mays grains in Maize Belt in Kenya. About 100 Zea mays grain samples together with 100 soil samples were collected from the study site, put in separate labeled Ziplocs and were transported to laboratories at room temperature for analysis. Maize grains were analyzed for selenium while soil samples were analyzed for pH, Cat Ion Exchange Capacity, total carbon, and electrical conductivity. The mean selenium in Zea mays grains varied from 1.82 ± 0.76 mg/Kg to 11±0.86 mg/Kg. There was no significant difference between selenium levels between different grain batches {χ (Df =76) = 26.04 P= 1.00} The pH levels varied from 5.43± 0.58 to 5.85± 0.32. No significant correlations between selenium in grains and soil pH (Pearson’s correlations = - 0.143), and between selenium levels in grains and the four (pH,Tcarbon,CEC,Eh) soil chemical characteristics {F (4,91) = 0.721 p = 0.579} was observed.It can be concluded that the soil chemical characteristics in the study site did not significantly affect the accumulation of native selenium in Zea mays grains.

Keywords: maize, native, soil, selenium

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10420 Analysis of in Vitro Biocompatibility Studies of Silicate-Based Bioceramic Cements: A Scoping Review

Authors: Olphiara Rodolpheza Alexandre, Carla David, Rafael Guerra Lund, Nadia Ferreira

Abstract:

Due to the increasing demand for biomaterials in the dental field, especially in endodontics, calcium silicate-based cements (CSCs) have gained prominence because of their biocompatibility and tissue regeneration capabilities. Originating from Mineral Trioxide Aggregate (MTA), the first bioceramic in endodontics derived from Portland cement, these materials are becoming increasingly prevalent in the market. For any drug released to the market, pharmacovigilance must ensure the absence of adverse health effects on consumers through rigorous toxicological testing. Although these materials have undergone in vitro and in vivo testing, such tests have typically been conducted over a limited period. Some effects may only become apparent after several years, and these studies are generally carried out on a non-specific population. However, the variety of calcium silicate-based products, including cement and sealers, raises questions about their toxicity, particularly considering potential long-term effects not addressed in existing studies. While the scientific literature includes comparative studies on the toxicity of these materials, the consistency of their conclusions is often controversial. Therefore, this project aims to map the scientific evidence from in vitro biocompatibility studies, including those investigating the toxicity of calcium silicate-based bioceramics.

Keywords: toxicity, toxicity test, bioceramics, calcium silicate, genotoxicity

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10419 The Assessment of Nephrotoxic Effects of Peganum Harmala In Rat

Authors: Amal Yamani, Jaber Elgtou, Aziz Mohammed, Lazaar Jamila, Elachouri Mostafa

Abstract:

Peganum harmala used traditionally as an emenagogue and abortifacient agent in Morocco phytotherapy. Even thought its benefits effects, Peganum harmala remained severely toxic for the organism especially in strong doses. The present study was initiated to evaluate the nephrotoxic effects of aqueous extract of Peganum harmala seeds (PHS). The solution containing aqueous extract of PHS was administered orally by gavage at the dose of 2g/kg body weight during twenty days. Rats were used in this study, two groups were considered, a treated group received an extract of PHS at dose 2g/kg bodyweight and control group received an amount of tap water equivalent to the volume of the vehicle used for the dose of PHS extract. The data we collected showed that aqueous extracts of PHS administered during twenty days induced a significant changes in renal function expressed in decreases of diuresis (from 10 ± 0,58 to 5,33 ± 0,33 ml/24 hours) and the same profile for mean arterial blood pressure (from 125 ± 2,89 to 96,67 ± 6,01 mmHg). The histopathological study showed an alteration of kidney cells in treated group with regard the control group which is not affected. In conclusion: our results indicate that the aqueous extract of PHS induces toxicity may affect severely kidney function and causes renal histopathology.

Keywords: peganum harmala seeds, nephrotoxic, diuresi, histpathology, kidney

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10418 Cardioprotective Effects of Grape Seed Extract against Lipo-toxicity and Energy Metabolism Alterations in High-Fat-Diet-Induced Obese Rats

Authors: Thouraya Majoul

Abstract:

Obesity is now a real public health issue throughout the world, and it is well-established that obesity leads to cardiovascular diseases. The prevention and treatment of obesity using nutritional supplements has become a realistic and effective approach. This study was carried out to analyze the incidence of a high-fat diet on rat heart metabolism as well as on fatty acids composition, then to investigate the eventual protective effects of a grape seed extract (GSE). The experimental design consisted of three rat groups subjected to three different conditions; standard (SD), high-fat diet (HFD) and HFD+GSE (HG). We showed that GSE counteracted the effect of HFD on fatty acid composition, namely, docosapentaenoic acid, docosahexaenoic acid, arachidonic acid (ARA), palmitic acid (PA) and palmitoleic acid. Besides, GSE treatment restored HFD-altered metabolic pathways through the recovery of some cardiac enzyme activities such as lipase, glucose 6 phosphate dehydrogenase and pyruvate dehydrogenase. The cardiac lactate level and lactate dehydrogenase activity were also analyzed in relation to HFD and GSE administration. To our knowledge, this is the first study showing the anti-obesity and cardioprotective effects of GSE in relation to fatty acid composition and some cardiac enzymes, supporting its role as a therapeutic agent of obesity.

Keywords: Grape seed extract, phenolic, obesity, cardioprotective, lipotoxicity, energy metabolism

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10417 Effects of Knitting Variables for Pressure Controlling of Tubular Compression Fabrics

Authors: Shi Yu, Rong Liu, Jingyun Lv

Abstract:

Compression textiles with ergonomic-fit and controllable pressure performance have demonstrated positive effect on prevention and treatment of chronic venous insufficiency (CVI). Well-designed compression textile products contribute to improving user compliance in their daily application. This study explored the effects of multiple knitting variables (yarn-machinery settings) on the physical-mechanical properties and the produced pressure magnitudes of tubular compression fabrics (TCFs) through experimental testing and multiple regression modeling. The results indicated that fabric physical (stitch densities and circumference) and mechanical (tensile) properties were affected by the linear density (yarn diameters) of inlay yarns, which, to some extent, influenced pressure magnitudes of the TCFs. Knitting variables (e.g., feeding velocity of inlay yarns and loop size settings) can alter circumferences and tensile properties of tubular fabrics, respectively, and significantly varied pressure values of the TCFs. This study enhanced the understanding of the effects of knitting factors on pressure controlling of TCFs, thus facilitating dimension and pressure design of compression textiles in future development.

Keywords: laid-in knitted fabric, yarn-machinery settings, pressure magnitudes, quantitative analysis, compression textiles

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10416 Predictors of Post-marketing Regulatory Actions Concerning Hepatotoxicity

Authors: Salwa M. Almomen, Mona A. Almaghrabi, Saja M. Alhabardi, Adel A. Alrwisan

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Background: Hepatotoxicity is a major reason for medication withdrawal from the markets. Unfortunately, serious adverse hepatic effects can occur after marketing with limited indicators during clinical development. Therefore, finding possible predictors for hepatotoxicity might guide the monitoring program of various stakeholders. Methods: We examined the clinical review documents for drugs approved in the US from 2011 to 2016 to evaluate their hepatic safety profile. Predictors: we assessed whether these medications meet Hy’s Law with hepatotoxicity grade ≥ 3, labeled hepatic adverse effects at approval, or accelerated approval status. Outcome: post-marketing regulatory action related to hepatotoxicity, including product withdrawal or updates to warning, precaution, or adverse effects sections. Statistical analysis: drugs were included in the analysis from the time of approval until the end of 2019 or the first post-marketing regulatory action related to hepatotoxicity, whichever occurred first. The hazard ratio (HR) was estimated using Cox-regression analysis. Results: We included 192 medications in the study. We classified 48 drugs as having grade ≥ 3 hepatotoxicities, 43 had accelerated approval status, and 74 had labeled information about hepatotoxicity prior to marketing. The adjusted HRs for post-marketing regulatory action for products with grade ≥ 3 hepatotoxicity was 0.61 (95% confidence interval [CI], 0.17-2.23), 0.92 (95%CI, 0.29-2.93) for a drug approved via accelerated approval program, and was 0.91 (95%CI, 0.33-2.56) for drugs with labeled hepatotoxicity information at approval time. Conclusion: This study does not provide conclusive evidence on the association between post-marketing regulatory action and grade ≥ 3 hepatotoxicity, accelerated approval status, or availability of labeled information at approval due to sampling size and channeling bias.

Keywords: accelerated approvals, hepatic adverse effects, drug-induced liver injury, hepatotoxicity predictors, post-marketing withdrawal

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10415 Vibration Behavior of Nanoparticle Delivery in a Single-Walled Carbon Nanotube Using Nonlocal Timoshenko Beam Theory

Authors: Haw-Long Lee, Win-Jin Chang, Yu-Ching Yang

Abstract:

In the paper, the coupled equation of motion for the dynamic displacement of a fullerene moving in a (10,10) single-walled carbon nanotube (SWCNT) is derived using nonlocal Timoshenko beam theory, including the effects of rotary inertia and shear deformation. The effects of confined stiffness between the fullerene and nanotube, foundation stiffness, and nonlocal parameter on the dynamic behavior are analyzed using the Runge-Kutta Method. The numerical solution is in agreement with the analytical result for the special case. The numerical results show that increasing the confined stiffness and foundation stiffness decrease the dynamic displacement of SWCNT. However, the dynamic displacement increases with increasing the nonlocal parameter. In addition, result using the Euler beam theory and the Timoshenko beam theory are compared. It can be found that ignoring the effects of rotary inertia and shear deformation leads to an underestimation of the displacement.

Keywords: single-walled carbon nanotube, nanoparticle delivery, Nonlocal Timoshenko beam theory, Runge-Kutta Method, Van der Waals force

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10414 The Effects of Vitamin D Supplementation on Anthropometric Indicators of Adiposity and Fat Distribution in Children and Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Authors: Simin Zarea Karizi, Somaye Fatahi, Amirhossein Hosseni

Abstract:

Background: There are conflicting findings regarding the effect of vitamin D supplementation on obesity-related factors. This study aimed to investigate the effect of vitamin D supplementation on changes in anthropometric indicators of adiposity and fat distribution in children and adolescents. Methods: Original databases were searched using standard keywords to identify all controlled trials investigating the effects of vitamin D supplementation on obesity-related factors in children and adolescents. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model analysis. Results: Fourteen treatment arms were included in this systematic review and meta-analysis. The quantitative meta-analysis revealed no significant effect of vitamin D supplement on BMI (-0.01 kg/m2; 95% CI: -0.09, 0.12; p= 0.74; I2=0.0%), BMI z score (0.02; 95% CI: -0.04, 0.07; p= 0.53; I2=0.0%) and fat mass (0.07%; 95% CI: -0.09 to 0.24; p= 0.38; I2=31.2%). However, the quantitative meta-analysis displayed a significant effect of vitamin D supplementation on WC compared with the control group (WMD=-1.17 cm, 95% CI: -2.05, -0.29, p=0.009; I2=32.0 %). It seems that this effect was greater in healthy children with duration>12 weeks, dose<=400 IU and baseline less than 50 nmol/l vitamin D than others. Conclusions: Our findings suggest that vitamin D supplementation may be a protective factor of abdominal obesity and should be evaluated on an individual basis in clinical practice.

Keywords: weight loss, vitamin D, anthropometry, children, adolescent

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10413 Microplastics in Urban Environment – Coimbra City Case Study

Authors: Inês Amorim Leitão, Loes van Shaick, António Dinis Ferreira, Violette Geissen

Abstract:

Plastic pollution is a growing concern worldwide: plastics are commercialized in large quantities and it takes a long time for them to degrade. When in the environment, plastic is fragmented into microplastics (<5mm), which have been found in all environmental compartments at different locations. Microplastics contribute to the environmental pollution in water, air and soil and are linked to human health problems. The progressive increase of population living in cities led to the aggravation of the pollution problem worldwide, especially in urban environments. Urban areas represent a strong source of pollution, through the roads, industrial production, wastewater, landfills, etc. It is expected that pollutants such as microplastics are transported diffusely from the sources through different pathways such as wind and rain. Therefore, it is very complex to quantify, control and treat these pollutants, designated current problematic issues by the European Commission. Green areas are pointed out by experts as natural filters for contaminants in cities, through their capacity of retention by vegetation. These spaces have thus the capacity to control the load of pollutants transported. This study investigates the spatial distribution of microplastics in urban soils of different land uses, their transport through atmospheric deposition, wind erosion, runoff and streams, as well as their deposition in vegetation like grass and tree leaves in urban environment. Coimbra, a medium large city located in the central Portugal, is the case-study. All the soil, sediments, water and vegetation samples were collected in Coimbra and were later analyzed in the Wageningen University & Research laboratory. Microplastics were extracted through the density separation using Sodium Phosphate as solution (~1.4 g cm−3) and filtration methods, visualized under a stereo microscope and identified using the u-FTIR method. Microplastic particles were found in all the different samples. In terms of soils, higher concentrations of microplastics were found in green parks, followed by landfills and industrial places, and the lowest concentrations in forests and pasture land-uses. Atmospheric deposition and streams after rainfall events seems to represent the strongest pathways of microplastics. Tree leaves can retain microplastics on their surfaces. Small leaves such as needle leaves seem to present higher amounts of microplastics per leaf area than bigger leaves. Rainfall episodes seem to reduce the concentration of microplastics on leaves surface, which suggests the wash of microplastics down to lower levels of the tree or to the soil. When in soil, different types of microplastics could be transported to the atmosphere through wind erosion. Grass seems to present high concentrations of microplastics, and the enlargement of the grass cover leads to a reduction of the amount of microplastics in soil, but also of the microplastics moved from the ground to the atmosphere by wind erosion. This study proof that vegetation can help to control the transport and dispersion of microplastics. In order to control the entry and the concentration of microplastics in the environment, especially in cities, it is essential to defining and evaluating nature-based land-use scenarios, considering the role of green urban areas in filtering small particles.

Keywords: microplastics, cities, sources, pathways, vegetation

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10412 Sexually Dimorphic Effects of Chronic Exercise and Myocytic Androgen Receptor Overexpression on Body Composition in Sprague dawley Rats

Authors: Sabrina Barsky, Ashley Monks

Abstract:

In humans, exercise improves symptoms of various pathological states, although exercise adaptations seem to differ in response to sex. Skeletal muscle anabolism is thought to be regulated by androgen receptor (AR) through poorly specified mechanisms. Interactions of AR and exercise on muscle phenotype remain inconclusive in males, and undetermined in females. We hypothesized that sex differences in exercise adaptations are regulated by the androgenic system and the type of exercise performed. Here we examined interactions between a muscle-specific AR overexpression transgene (HSA-AR) and forced aerobic exercise paradigm on muscle and adipose exercise adaptation in male and female rats. We used dual-energy X-ray absorptiometry (DXA) to examine body composition adaptations post 9-week exercise protocol. We replicated the effects of HSA-AR on body composition, with males only having increased % lean mass and reduced % fat mass (P<0.05). Aerobic exercise improved lean body phenotype significantly, with lesser indices of total and % fat mass (P<0.01) in both sexes. Sex-specific effects of exercise included decreased total body mass (P<0.01) in males and increased lean mass % (P<0.001) in females. Surprisingly, neither AR manipulation nor exercise affected bone parameters in either sex. This varied response in total mass and lean mass according to exercise presents a sexually dimorphic response to exercise. Neither sex showed an interaction between HSA-AR and forced aerobic exercise on body composition. Future work is proposed to examine the effects of exercise type (aerobic versus resistance) and the role of gonadal androgens in sexually dimorphic exercise-mediated mitochondrial adaptations. This work implicates the development of sex-specific exercise therapies.

Keywords: androgen receptor, forced exercise, muscle physiology, sexual dimorphism

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10411 Exploring the Dark Side of IT Security: Delphi Study on Business’ Influencing Factors

Authors: Tizian Matschak, Ilja Nastjuk, Stephan Kühnel, Simon Trang

Abstract:

We argue that besides well-known primary effects of information security controls (ISCs), namely confidentiality, integrity, and availability, ISCs can also have secondary effects. For example, while IT can add business value through impacts on business processes, ISCs can be a barrier and distort the relationship between IT and organizational value through the impact on business processes. By applying the Delphi method with 28 experts, we derived 27 business process influence dimensions of ISCs. Defining and understanding these mechanisms can change the common understanding of the cost-benefit valuation of IT security investments and support managers' effective and efficient decision-making.

Keywords: business process dimensions, dark side of information security, Delphi study, IT security controls

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10410 Assessment of Soil Salinity through Remote Sensing Technique in the Coastal Region of Bangladesh

Authors: B. Hossen, Y. Helmut

Abstract:

Soil salinity is a major problem for the coastal region of Bangladesh, which has been increasing for the last four decades. Determination of soil salinity is essential for proper land use planning for agricultural crop production. The aim of the research is to estimate and monitor the soil salinity in the study area. Remote sensing can be an effective tool for detecting soil salinity in data-scarce conditions. In the research, Landsat 8 is used, which required atmospheric and radiometric correction, and nine soil salinity indices are applied to develop a soil salinity map. Ground soil salinity data, i.e., EC value, is collected as a printed map which is then scanned and digitized to develop a point shapefile. Linear regression is made between satellite-based generated map and ground soil salinity data, i.e., EC value. The results show that maximum R² value is found for salinity index SI 7 = G*R/B representing 0.022. This minimal R² value refers that there is a negligible relationship between ground EC value and salinity index generated value. Hence, these indices are not appropriate to assess soil salinity though many studies used those soil salinity indices successfully. Therefore, further research is necessary to formulate a model for determining the soil salinity in the coastal of Bangladesh.

Keywords: soil salinity, EC, Landsat 8, salinity indices, linear regression, remote sensing

Procedia PDF Downloads 352
10409 Sensitivity Analysis of Oil Spills Modeling with ADIOS II for Iranian Fields in Persian Gulf

Authors: Farzingohar Mehrnaz, Yasemi Mehran, Esmaili Zinat, Baharlouian Maedeh

Abstract:

Aboozar (Ardeshir) and Bahregansar are the two important Iranian oilfields in Persian Gulf waters. The operation activities cause to create spills which impacted on the marine environment. Assumed spills are molded by ADIOS II (Automated Data Inquiry for Oil Spills) which is NOAA’s weathering oil software. Various atmospheric and marine data with different oil types are used for the modeling. Numerous scenarios for 100 bbls with mean daily air temperature and wind speed are input for 5 days. To find the model sensitivity in each setting, one parameter is changed, but the others stayed constant. In both fields, the evaporated and dispersed output values increased hence the remaining rate is reduced. The results clarified that wind speed first, second air temperature and finally oil type respectively were the most effective factors on the oil weathering process. The obtained results can help the emergency systems to predict the floating (dispersed and remained) volume spill in order to find the suitable cleanup tools and methods.

Keywords: ADIOS, modeling, oil spill, sensitivity analysis

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10408 Biochemical Studies on the Effects of Cymbopogon citratus (Lemon Grass) on Wistar Albino Rats

Authors: Adegbegi Ademuyiwa Joshua, Onoagbe Iyare

Abstract:

Medicinal plants have been recognized to have therapeutic effects and they may also have toxic side effects. The present study was undertaken to investigate the effect of extracts of Cymbopogon citratus on normal rats. Blood glucose levels of all animals were determined. Biochemical studies carried out to determine the oxidative status by measuring activities of superoxide dismutase (SOD) and catalase (CAT), and in the liver, kidney and pancrease. Oral administration of ethanolic and aqueous extract of C. citratus at a doses of 200 mg/kg body weight, for a period of 30 days, caused a significant (p<0.05) reduction in blood glucose levels. Effect on hormonal profile (TSH, T3, and T4) was also determined, and was found to be significantly higher in all the administered groups when compared with control. Lipid profiles levels; Total cholesterols, triglycerides, high density lipoprotein-cholesterol and low density lipoprotein-cholesterol were significantly (p>0.05) higher for all treated rats as compared against control. SOD, catalase, GSH and Vitamin C activities in the tissues (liver, kidney and pancrease) of the rats treated with the medicinal plants were generally higher or statistical slightly similar to control. Histopathology result showed that both ethanolic and aqueous extracts (200 mg/kg body weight) of C. citratus was safer as no adverse effects were observed in the organs examined. Findings in this study showed that this plant has hypoglycemic properties and did not exert oxidative damage; in some instances, particularly in the liver, kidney and pancreas as well as its relative safety and possible use for weight gain.

Keywords: medicinal plants, blood glucose, cymbopogon citratus, hypoglycaemic, oxidative status

Procedia PDF Downloads 474
10407 Lymphomas as Estrogen-Regulated Cancers

Authors: M. S. Hasni, J. Guan, K. Yakimchuk, M. Berglund, B. Sander, G. Enblad, R. M. Amini, S. Okret

Abstract:

Lymphomas are generally not considered as endocrine-related cancers. However, most lymphoid malignancies show gender differences in incidence and show prognosis with males being more affected. Furthermore, some epidemiological data indicate a protective role of estrogens against Non-Hodgkin lymphomas. Recent studies have demonstrated estrogen receptor β (ERβ) to be the major ER expressed in normal and malignant cells of lymphoid origin. We have analyzed the effects of estradiol and selective ERα and ERβ agonists on lymphoma growth in culture and in vivo. Treating lymphoma cells with estradiol or ERα selective agonist had minor or no effect on cell growth while selective ERβ agonist treatment showed an antiproliferative effect. When grafting mice with murine T lymphoma cells, male mice developed larger tumors compared to female mice, a difference that was abolished following ovariectomy, demonstrating estrogen-dependent growth in vivo. When subcutaneously grafting lymphoma cells to mice, so far growth of all tested human B lymphoma tumors (Raji and Ramos Burkitt lymphoma, SU.DHL4 (GC) and U2932 (ABC) DLBCL, Granta-519, Maver1 and Z138 MCL cells), were reduced following treatment with ERβ selective agonist (ref. 2 and unpublished). Moreover, the number and size of liver foci of disseminating Raji cells was reduced. We have identified target genes and mechanism that could explain the above effects of ERβ agonists. This included effects on angio and lymphangiogenesis. Now we have further analyzed effects of ERβ agonists on Ibrutinib-sensitive and -insensitive MCL cells in xenograft experiments as well as ERβ expression in primary lymphoma material (DLBCL). Preliminary statistical analysis has been done correlating ERβ expression to other biomarkers and clinical data.

Keywords: lymphomas, estrogen receptors, cancer, liver foci

Procedia PDF Downloads 414
10406 On Pooling Different Levels of Data in Estimating Parameters of Continuous Meta-Analysis

Authors: N. R. N. Idris, S. Baharom

Abstract:

A meta-analysis may be performed using aggregate data (AD) or an individual patient data (IPD). In practice, studies may be available at both IPD and AD level. In this situation, both the IPD and AD should be utilised in order to maximize the available information. Statistical advantages of combining the studies from different level have not been fully explored. This study aims to quantify the statistical benefits of including available IPD when conducting a conventional summary-level meta-analysis. Simulated meta-analysis were used to assess the influence of the levels of data on overall meta-analysis estimates based on IPD-only, AD-only and the combination of IPD and AD (mixed data, MD), under different study scenario. The percentage relative bias (PRB), root mean-square-error (RMSE) and coverage probability were used to assess the efficiency of the overall estimates. The results demonstrate that available IPD should always be included in a conventional meta-analysis using summary level data as they would significantly increased the accuracy of the estimates. On the other hand, if more than 80% of the available data are at IPD level, including the AD does not provide significant differences in terms of accuracy of the estimates. Additionally, combining the IPD and AD has moderating effects on the biasness of the estimates of the treatment effects as the IPD tends to overestimate the treatment effects, while the AD has the tendency to produce underestimated effect estimates. These results may provide some guide in deciding if significant benefit is gained by pooling the two levels of data when conducting meta-analysis.

Keywords: aggregate data, combined-level data, individual patient data, meta-analysis

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10405 Effects of Age and Energy Expenditure on Obesity Among Adults in Abeokuta, Nigeria

Authors: Adeniyi Samuel Adekoya

Abstract:

The study assessed the independent effects of age and energy expenditure on the risks of obesity among adults (20-64 years). A cross-sectional study with changes in age, changes in work and leisure-time, and physical activities information played roles, with cut-off for energy expenditure and BMI in rural and urban localities. Physical activity information determined the energy expenditure, while the BMI determined the risk of obesity among the subjects. Statistically, age has a strong and direct association with obesity in both rural and urban settings, while energy expenditure was inverse in its association. Findings from the this study showed that in developing societies, age tends to be a risk factor for obesity, whereas energy expenditure is to be protective. Level of education and economic development are also relevant modifiers of the influences exerted by these variables.

Keywords: age, energy expenditure, BMI, rural/urban

Procedia PDF Downloads 436
10404 A Thermodynamic Solution for the Static and Dynamic Characteristics of a Two-Lobe Journal Bearing

Authors: B. Chetti, W. A. Crosby

Abstract:

The work described in this paper is an investigation of the static and dynamic characteristics of two-lobe journal bearings taking into consideration the thermal effects. A thermo-hydrodynamic solution of a finite two-lobe journal bearing is performed by solving the generalized form Reynolds equation with the energy equation, taking into consideration viscosity variation across the film thickness. The static and dynamic characteristics were numerically obtained. The results are evaluated for different values of viscosity-temperature coefficient and Peclet number. The results show that considering the thermal effects in the solution of the two-lobe journal bearing has a marked on the study of its stability.

Keywords: two-lobe bearing, thermal effect, static, dynamic characteristics

Procedia PDF Downloads 391
10403 Effects of Ingredients Proportions on the Friction Performance of a Brake Pad Material

Authors: Rukiye Ertan

Abstract:

In this study, a brake friction material composition was investigated experimentally related to the effects of the friction modifiers and abrasive proportions on the tribological properties. The investigation was based on a simple experimental formulation, consisting of seven friction materials with different proportions of abrasives (ZrSiO4 and Fe2O3) and friction modifiers (cashew dust). The friction materials were evaluated using a Chase friction tester. The tribological properties, such as the wear resistance and friction stability, depending on the test temperature and the number of braking were obtained related to the friction material ingredient proportions. The results showed that the tribological properties of the brake pad were greatly affected by the abrasive and then cashew dust proportion.

Keywords: brake pad, friction, wear, abrasives

Procedia PDF Downloads 443