1,227 research outputs found
Gender Differences in the Corporate Social Responsibility Orientation of Credit Union Board Members
Credit unions serve an important purpose in the U.S. economy by providing financial services to low- and moderate-income individuals. Their assets have steadily grown from 655 billion between 1990 and 2004. In spite of these impressive growth rates, a number of writers have expressed great concern regarding credit union governance, particularly over the role and functions of the board\u27s members. More recently, the financial crisis has raised important questions regarding the board\u27s level of involvement and its ethical and social responsibilities in corporate decision making. One area which has remained relatively unexplored concerns the attitudes of credit union board members toward corporate social responsibility. Furthermore, to date very little is known regarding the extent of similarities and differences between these organizations\u27 male and female board members with respect to this issue. The present study was designed to investigate this issue. A survey of 470 directors of 80 credit unions revealed significant differences between the genders with respect to the legal and ethical components of corporate social responsibility. Compared to their male counterparts, the female directors exhibited greater concern about the legal dimension of corporate responsibility and a weaker orientation toward ethics. No significant differences between the two groups were observed with respect to the economic and discretionary components
Quantum phase transitions in holographic models of magnetism and superconductors
We study a holographic model realizing an "antiferromagnetic" phase in which
a global SU(2) symmetry representing spin is broken down to a U(1) by the
presence of a finite electric charge density. This involves the condensation of
a neutral scalar field in a charged AdS black hole. We observe that the phase
transition for both neutral and charged (as in the standard holographic
superconductor) order parameters can be driven to zero temperature by a tuning
of the UV conformal dimension of the order parameter, resulting in a quantum
phase transition of the Berezinskii-Kosterlitz-Thouless type. We also
characterize the antiferromagnetic phase and an externally forced ferromagnetic
phase by showing that they contain the expected spin waves with linear and
quadratic dispersions respectively.Comment: 24 pages; v2: references added, typos correcte
Molecular simulation of propane/propylene separation on the metal–organic framework CuBTC
We present results of molecular simulation of pure propane and propylene, as well as their binary mixtures in the metal-organic framework CuBTC. By comparing simulated and experimental pure-component isotherms we are able to describe the adsorption mechanism of these two molecules. The main difference is the existence of strong specific interactions between the open metal sites of CuBTC, freed by framework dehydration during the activation process, and the pi orbitals of the propylene double bond. The net result is a moderate selectivity (up to 4) of the material for propylene adsorption. Given the current lack of experimental data for propane/propylene mixture adsorption in CuBTC, we have compared the molecular simulation results to predictions from Ideal Adsorbed Solution Theory using single-component experimental adsorption isotherms as input. Our comparison suggests that IAST is likely to adequately describe this system, and differences between the theory and simulation are probably due to shortcomings of the simplified potential model used to represent the pi-metal interactions
Host range, damage and seasonality of fruit flies in Sennar State, Sudan
Fruit flies (Diptera: Tephritidae) are one of the most economically important groups of insects in the afrotropical region because they cause damage to fruits and vegetables. Integrated fruit fly (FF) control program requires accurate data about taxonomy, incidence, distribution and seasonality of the members of this pest. Surveys and collection missions were carried out in Sennar State during January 2006- January 2008. Yellow sticky traps were used for adult collection. Trapped fruit flies were labeled, identified and counted monthly to estimate their abundance throughout the year. In addition, infested fruits of mango, guava, grapefruit, orange, banana, melons, pumpkin, watermelon, and the wild magad (Cucurbitaceae) were collected monthly from the surveyed areas. Larvae were reared till the adult stage and identified. Field infestation rate of FF species was determined on mango and guava at Singa area. Percentage of FF infestation on mango Baladi cultivar was 10% in March, 15% in April and 20% in May. During the period from June to August, Abu Samaka cultivar was the only mango cultivar available, and accordingly, was subjected to a heavy attack by the FF. The infestation reached 30% in June and 50% in July. The FF moved to guava, during the period from October to December. The rate of FF infestation on guava was very high during this period and ranged from 80% to 90%. Mango fruits in Singa area were infested by Bactrocera invadens (Drew, Tsuruta and White) (80%), C. cosyra (19.8%) and Dacus longistylus (Wiedemann) (0.2%) of the total emerged adults. This was the first record for the latter species in a host other than Calotropis procera (Apocynaceae). Guava fruits were infested by B. invadens (84.5%), C. cosyra (15.3%), and C. quinaria (Bezzi) (0.2%) of the total emerged adults. B. invadens seemed to out-compete and replace the indigenous species. Cucurbit fruits hosted D. ciliatus (Leow) only. The wild magad fruits hosted B. invadens and B. cucurbitae (Coquillet). The highest population of B.invadenss was observed during July and December (254 and 253 adults/trap, respectively). March and April showed the lowest population due to higher temperatures and low relative humidity.
 
Thermal analysis of space debris for infrared based active debris removal
In space, visual based relative navigation systems suffer from dynamic illumination conditions of the target (Eclipse conditions, solar glare...etc.) where most of these issues are addressed by advanced mission planning techniques. However, such planning would not be always feasible or even if it is, it would not be straightforward for Active Debris Removal (ADR) missions. On the other hand, using an infrared based system would overcome this problem, if a guideline to predict infrared signature of space debris based on the target thermal profile could be provided for algorithm design and testing.
Spacecraft thermal design is unique to every platform. This means every ADR target will have a different infrared signature which changes over time not just only due to orbital dynamics but also due to its thermal surface coatings. In order to provide a space debris infrared signature guideline for most of the possible ADR targets, we introduce an innovative grouping system for thermal surface coatings based on their behaviour in Space environment. Through the use of this grouping system, we propose a space debris infrared signature estimation method which was extensively verified by our simulations and experiments. During our verifications, we have also found out very important problem so called ”Signature Ambiguity” that is unique to Infrared Based Active Debris Removal (IR-ADR) systems which we have also discussed in our work
Biodrying process: a sustainable technology for treatment of municipal solid wastes organic fraction
[EN] The Municipal Solid Waste of Agareb (Sfax –Tunisia), characterized by high organic fraction and moisture contents is the most worrying pollution source that must be managed by innovative treatment and recycling technologies. Bio-drying, as a waste to energy conversion technology, aims at reducing moisture content of this organic matter. This concept, similar to composting, is accomplished by using the heat generated from the microbial degradation of the waste matrix, while forced aeration is used. The purpose of this work was to reduce the moisture content of the waste, by maximizing drying and minimizing organic matter biodegradation, in order to produce a solid recovered fuel with high calorific value.Kechaou, N.; Ammar, E. (2018). Biodrying process: a sustainable technology for treatment of municipal solid wastes organic fraction. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1953-1960. https://doi.org/10.4995/IDS2018.2018.7842OCS1953196
Missed case of Axenfeld-Rieger syndrome: a case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Hypoglycemic and toxic effects of saponins from the fruit of bitter apple [Citrullus colocynthis (L.) Schrad] on the internal organs of Norway rat [Rattus norvegicus (Berkenhout)]
Nowadays, natural products receive attention to research centers because of their special importance in safety of communities. The curative properties of these plants are mainly due to the presence of various complex chemical substances of different composition which occur as secondary metabolites.The main objectives of this study were to evaluate saponins toxic effects as reflected in the histopathological changes in the internal organs of Norway rats and to study the hypoglycemic effects induced by the same group. Powdered dried fruit parts (rinds, pulps and seeds) of bitter apple were screened for detection of saponins, glycosides, terpenes, anthraquinones, flavonoids, tannins, alkaloids, coumarins, cardiac glycosides, cyanogenic glycosides and cucurbitacins. The results of the qualitative analysis and phytochemical screening profiles indicated that, most of the natural products tested for were present in the plant material, except cyanogenic glycosides. Crude saponins were extracted from the rind and their acute toxicity was determined on Norway rats. Five dosage levels (60, 70, 80, 90 and 100 mgs saponins/rat) were administered intraperitoneally
to each batch of albino rats (4 rats/batch). The histological changes in the liver exhibited prominent nucleolus, open chromatin, congestion of central veins and liver sinusoids. The kidney showed signs of reduced renal tubules and lining of epithelial cells. The stomach and digestive system showed mucosal edema, open chromatin, prominent nucleolus and structural necrosis. Percentages reduction in glucose level in treated rats and the control after six hours were 42%, 55.4%, 60%, 62.5%, 69.3 and 0.10 %, following the same order. There was a considerable dose-dependent decrease in the mean concentration of glucose in the plasma of the treated rats.
أصبحت المنتجات النباتية الطبيعية في الآونة الأخيرة محوراً مهماً للبحث في الكثير من المراكز البحثية، وذلك لأهميتها الخاصة في سلامة المجتمعات. تعود الخواص العلاجية لهذه النباتات لاحتوائها على العديد من المركبات الكيمائية المعقدة ذات التراكيب المتباينة والتي توجد فيها على صورة نواتج ثانوية لعملية الأيض. هدفت هذه الدراسة إلي تقويم الآثار الخافضة للسكر والآثار السامة لصابوينات الحنظل والتغيرات النسيجية التي تحدثها على الأعضاء الداخلية للجرذ النرويجي. تم كل ذلك عبر عدة طرق هدفت للكشف عن وتسمية مجاميع المواد الفاعلة في مسحوق ثمار نبات الحنظل C.colocynthis (L.)Schradوشملت هذه المواد الصابونينات، الجلايكوسيدات والفلافونويدات والقلويدات والأنثروكينونات، والتربينات والتانينات والكومارينات، الجلايكوسيدات القلبية والجلايكوسيدات والسيانوجينية والكيوكيربتسينات. كانت النتائج كلها إيجابية مع غياب الجلايكوسيدات السيانوجينية. تم اختبار السمية الحادة للصابونينات المستخلصة من قشور ثمار نبات الحنظل علي طريق الحقن عبر الغشاء البروتوني للجرذان النرويجية البهقاء Rattus norvegicus ( Berkenhout). بناءً على تجارب أولية تم اختبار خمس جرعات وهى 60 ، 70، 80، 90 و100 مجم صابونين خام/جرذ. فيما يختص بالتغيرات النسيجية على الأعضاء والأنسجة الداخلية للجرذان المعاملة بالصابونين فقد لوحظ أنها شملت تشوه الأنوية وانفتاح الكروماتين واحتقان الأوردة في خلايا الكبد مع انخفاض الخلايا الطلائية المبطنة للأنيبيبات البولية في الكلى. أما بالنسبة للتغيرات في المعدة والجهاز الهضمي فشملت وزمة الغشاء المخاطي، وانفتاح الكروماتين مع تشوه الأنوية وموت الأنسجة. تمت أيضا دراسة أثر الصابونينات علي خفض معدل السكر في دم الجرذان المعاملة بالجرعات السابقة وكذا الشاهد حيث تم أخذ متوسط النسب المئوية لانخفاض السكر في الدم خلال ست ساعات وكانت المتوسطات42% ، 55.4%، 60%،62%، 69.3%، 0.10% وللشاهد على الترتيب. وقد لوحظ أن هنالك تدني ملحوظ في نسبة الجلوكوز في دم الجرذان المعاملة يتناسب عكسياً مع الجرعة المستخدمة
Detection of FXIII gene V34L and fibrinogen β-gene -455G/A polymorphisms among Saudi Arabia population via polymerase chain reaction-reverse hybridization technique
FXIII gene Val34Leu variant appears to be associated with decreased risk of myocardial infarction and venous thromboembolism as well as with increased risk of intracerebral hemorrhage. Fibrinogen β-gene SNP -455G/A are associated with differences in the plasma levels of fibrinogen and severity of arterial disease. The aim of the present work was to study the prevalence of FXIII gene V34L and Fibrinogen β-gene -455G/A SNPs in Saudi population. Among 200 blood samples randomly collected from unrelated healthy Saudi subjects, FXIII gene V34L and Fibrinogen β-gene -455G/A SNPs were genotyped via cardiovascular disease (CVD) StripAssay (ViennaLab, Austria. Homozygous (V/V) and heterozygous (V/L) genotypes were detected with 96 and 4%, respectively, among FXIII gene V34L genotypes, whereas (L/L) genotype was not found. The allele frequency was 0.98 for V allele and 0.02 for L allele. Three genotypes of Fibrinogen β-gene -455G/A SNP (GG, GA and AA) were obtained and its prevalence (%) was 70, 25 and 5, respectively. The frequency of G allele was 0.825 and 0.175 for A allele. Prevalence of FXIII gene Vl34L polymorphism and its allele frequency are in line with other Asian populations. Distribution of β-gene -455G/A genotypes and allele frequency are in accordance with previous reports in different ethnic groups. This is the first time to report these polymorphisms in Saudi Arabia population. This study provides valuable information on Saudi genetic background in comparison with other populations. In addition, it serves as a template for future clinical research involving cardiovascular and cerebrovascular diseases.Key words: FXIII gene V34L, fibrinogen β-gene -455G/A, polymorphisms, Saudi Arabia
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