14 research outputs found
Tetrahedral Elliptic Curves and the local-global principle for Isogenies
We study the failure of a local-global principle for the existence of
-isogenies for elliptic curves over number fields . Sutherland has shown
that over there is just one failure, which occurs for and a
unique -invariant, and has given a classification of such failures when
does not contain the quadratic subfield of the 'th cyclotomic field. In this
paper we provide a classification of failures for number fields which do
contain this quadratic field, and we find a new `exceptional' source of such
failures arising from the exceptional subgroups of
\mbox{PGL}_2(\mathbb{F}_l). By constructing models of two modular curves,
and , we find two new families of elliptic
curves for which the principle fails, and we show that, for quadratic fields,
there can be no other exceptional failures.Comment: The attachment contains annotated Sage code with details of the
computation
Security in Wireless Sensor Networks
Wireless Sensor Network (WSN) is an emerging technology that shows great promise for various futuristic applications both for mass public and military. The sensing technology combined with processing power and wireless communication makes it lucrative for being exploited in abundance in future. The inclusion of wireless communication technology also incurs various types of security threats. The intent of this paper is to investigate the security related issues and challenges in wireless sensor networks. We identify the security threats, review proposed security mechanisms for wireless sensor networks. We also discuss the holistic view of security for ensuring layered and robust security in wireless sensor networks
Canadian residents’ perceptions of cross-cultural care training in graduate medical school
Background: The Royal College of Physicians and Surgeons of Canada specifies both respect for diversity as a requirement of professionalism and culturally sensitive provision of medical care. The purpose of the present study was to evaluate the perception of preparedness and attitudes of medical residents to deliver cross-cultural care.Methods: The Cross Cultural Care Survey was sent via e-mail to all Faculty of Medicine residents (approx. 450) in an academic health sciences centre. Comparisons were made between psychiatry residents, family medicine residents, and other residency groups with respect to training, preparedness, and skillfulness in delivering cross-cultural care.Results: Seventy-three (16%) residents responded to the survey. Residents in psychiatry and family medicine reported significantly more training and formal evaluation regarding cross-cultural care than residents in other programs. However, there were no significant differences in self-reported preparedness and skillfulness. Residents in family medicine were more likely to report needing more practical experience working with diverse groups. Psychiatry residents were less likely to report inadequate cross-cultural training.Conclusion: While most residents reported feeling skillful and prepared to work with culturally diverse groups, they report receiving little additional instruction or formal evaluation on this topic, particularly in programs other than psychiatry and family medicine
A REVIEW ON PHYTOSOMES: NOVEL APPROACH FOR HERBAL PHYTOCHEMICALS
  The poor oral bioavailability of polyphenolic compound can be enhanced through the incorporation of them into phospholipid based self-assembled delivery system, i.e. popularly known as phytosome. Phyto†means plants and some†resembles a covering around/or a structure. Phytosome is generally prepared by reacting one or two moles of polyphenolic phytoconstituents and phospholipid. It may be either in the ratio of 1:1 and 1:2. By using phytosomes, one can also achieve enhanced rate and extent of the passage of lipophilic herbal constituents across lipid membrane that explains its character as a carrier as well as acid labile herbal drugs could also be protected in gastrointestinal tract. There are number of products available in the market that contains phytosomal drug delivery system such as Ginkgo biloba, Silybum marianum, and Camellia sinensis. The present review describes an updated overview of preparation of phytosomes, advancement in phytosomes technology, various herbal drugs for which phytosomes have been used as a carrier, its commercial availability and applications
Statistical properties of compact group extensions of non-uniformly expanding dynamical systems
We prove statistical limit theorems for Birkhoff sums of the form Pn−1 k=0 φn ◦ Th(n) , where Th(n) are a sequence of compact group extensions with non-uniformly expanding base and φn are a sequence of equivariant H¨older observables. This is done by extending the methods of Korepanov, Kosloff, and Melbourne to construct two new martingale-coboundary decompositions.
Even in the case of a fixed observable and compact group extension, these decompositions enable us not only to reprove existing results in the literature, but also to obtain far reaching consequences. Using our primary martingale-coboundary decomposition, we give a new proof of a central limit theorem and weak invariance principle under very general conditions, and obtain moment estimates which are optimal given our setup. Still in the case of a fixed observable and compact group extension, we use our secondary martingale-coboundary decomposition to prove an almost sure invariance principle with excellent error rates.
As an application, we prove a homogenisation result for discrete fast-slow dynamical systems with additive noise, where the fast dynamics are generated by a family of compact group extensions with non-uniformly expanding base
TERMINALIA CHEBULA: SUCCESS FROM BOTANY TO ALLOPATHIC AND AYURVEDIC PHARMACY
Terminalia chebula (TC) is a unique herb having various therapeutic potentials as anti-inflammatory, antioxidant, anticancer, and digestant. It belongs to family Combretaceae. In the present review, an attempt has been made to decipher classification, chemical constituents, therapeutic uses, and patents that have been reported for TC. Various pharmacological activities of TC that make it as potential medicine and its Ayurvedic formulations are highlighted.Keywords: Terminalia chebula, Anti-oxidant, Anti-cancer, Ayurvedic formulations, Anti-oxidant
SYNTHESIS OF COPPER NANOPARTICLES USING ASCORBIC ACID AND CETYL TRIMETHYL AMMONIUM BROMIDE
Objective: The present study highlights the development of a method to synthesize copper nanoparticles (CuNPs).Methods: CuNPs were developed using 0.01 M copper penta sulfate and 0.11 M of ascorbic acid (AA) and 0.03 M of cetyl trimethyl ammonium bromide solution. The synthesized CuNPs were differentiated through filtration and washed by water (deionized). CuNPs were kept in dialysis bag 70 KD in a 250 mL glass beaker along with distilled water. The assembly was kept on a magnetic stirrer for 24 h at 500 rpm. Then, the dialysis bag containing CuNPs solution was filtered by a filter assembly with 0.2 μm nylon filter. The filtered CuNPs were spray dried with the help of spray drier.Results: The prepared CuNPs were found to be 440 nm with zeta potential of −10 mV and polydispersity index 0.314.Conclusion: The investigation deciphers the promising and material technique to synthesis of CuNPs by methods for synthetic reduction utilizing strategy using AA (0.2 M) and sodium hydroxide (1 M), and Syloid 244FP
Comportamiento en fritura del aceite de salvado de arroz, aceite de girasol y mezclas de ambos aceites
Shall be deleted offer some advantages like better nutritional quality, lower cost and greater storage stability than pure oils. Model blends prepared from pure rice bran oil (RBO) and sunflower oil (SFO) were examined for change in their physico-chemical parameters (acid value, iodine value, color value, peroxide value and fatty acids). Repeated deep fat frying processes were carried out using dried potato chips in pure rice bran oil, sunflower oil and their model blends, in order to study the thermal behavior of pure rice bran oil, sunflower oil and their model blends. Pure rice bran oil and sunflower oil showed good thermal stability during the repeated deep fat frying cycles. Although all the blended oils used in the study showed good thermal stability during repeated deep fat frying cycles, model blends consisting of 60%RBO + 40% SFO showed better suitability during repeated deep fat frying than the remaining blended oils.La mezclas de aceites pueden ofrecer algunas ventajas sobre los aceites puros las como mejor calidad nutricional, coste inferior o mayor estabilidad durante el almacenamiento. En este estudio, aceite de salvado de arroz (RBO), aceite de girasol (SFO) y mezclas de ambos, se sometieron al proceso de fritura de patatas y se evaluaron los principales cambios fÃsico-quÃmicos en los aceites puros y en sus mezclas (acidez, Ãndice de yodo, color, Ãndice de peróxidos y composición de ácidos grasos). Aunque todas las muestras mostraron buena estabilidad a elevada temperatura, los mejores resultados se obtuvieron con la mezcla que contenÃa 60% de RBO y 40% de SFO
Prognostic risk factors for moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease: a systematic literature review
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. COPD exacerbations are associated with a worsening of lung function, increased disease burden, and mortality, and, therefore, preventing their occurrence is an important goal of COPD management. This review was conducted to identify the evidence base regarding risk factors and predictors of moderate-to-severe exacerbations in patients with COPD. METHODS: A literature review was performed in Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials (CENTRAL). Searches were conducted from January 2015 to July 2019. Eligible publications were peer-reviewed journal articles, published in English, that reported risk factors or predictors for the occurrence of moderate-to-severe exacerbations in adults age ≥ 40 years with a diagnosis of COPD. RESULTS: The literature review identified 5112 references, of which 113 publications (reporting results for 76 studies) met the eligibility criteria and were included in the review. Among the 76 studies included, 61 were observational and 15 were randomized controlled clinical trials. Exacerbation history was the strongest predictor of future exacerbations, with 34 studies reporting a significant association between history of exacerbations and risk of future moderate or severe exacerbations. Other significant risk factors identified in multiple studies included disease severity or bronchodilator reversibility (39 studies), comorbidities (34 studies), higher symptom burden (17 studies), and higher blood eosinophil count (16 studies). CONCLUSIONS: This systematic literature review identified several demographic and clinical characteristics that predict the future risk of COPD exacerbations. Prior exacerbation history was confirmed as the most important predictor of future exacerbations. These prognostic factors may help clinicians identify patients at high risk of exacerbations, which are a major driver of the global burden of COPD, including morbidity and mortality