Epstein Barr Virus and Atrial Fibrillation

Objective: Atrial fibrillation (AF) is very frequent and clinically significant arrhythmia. The incidence of atrial fibrillation is continuously rising. Meanwhile several risk factors for AF development have been identified but the etiology is not cleared. Methods: A systematic review and re-analysis of studies which investigated the relationship between AF and some risk factors was conducted. The method of the conditio sine qua non relationship, the method of the conditio per quam relationship, the method of the exclusion relationship and the mathematical formula of the causal relationship k were used to proof the hypothesis. Significance was indicated by a p-value of less than 0.05. Results: The studies analyzed were able to provide direct and indirect evidence that AF is caused by a process of inflammation while a direct identification of the factor causing AF was not possible. Still, it appears to be very probable that Epstein-Barr virus (EBV) is the cause of AF.  Conclusion: Atrial fibrillation (AF) appears to be caused by an EBV inflammatory process

Index of Unfairness

Objective. Objective scientific knowledge for many authors more valuable than true subjective belief is determined by research on primary data but a renewed analysis of already recorded or published data is common too. Ever since, an appropriate experimental or study design is an important and often a seriously underappreciated aspect of the informativeness and the scientific value of any (medical) study. The significance of study design for the reliability of the conclusions drawn and the ability to generalize the results from the sample investigated for the whole population cannot be underestimated. In contrast to an inappropriate statistical evaluation of a medical study, it is difficult to correct errors in study design after the study has been completed. Various mathematical aspects of study design are discussed in this article. Methods. In assessing the significance of a fair study design of a medical study, important measures of publication bias are introduced. Methods of data or publication bias analysis in different types of studies are illustrated through examples with fictive data. Formal mathematical requirements of a fair study design which can and should be fulfilled carefully with regard to the planning or evaluation of medical research are developed. Results. Various especially mathematical aspects of a fair study design are discussed in this article in detail. Depending on the particular question being asked, mathematical methods are developed which allow us to recognize data which are self-contradictory and to exclude these data from systematic literature reviews and meta-analyses. As a result, different individual studies can be summed up and evaluated with a higher degree of certainty. Conclusions. This article is intended to give the reader guidance in evaluating the design of studies in medical research even ex post which should enable the reader to categorize medical studies better and to assess their scientific quality more accurately

An improved optimization technique for estimation of solar photovoltaic parameters

The nonlinear current vs voltage (I-V) characteristics of solar PV make its modelling difficult. Optimization techniques are the best tool for identifying the parameters of nonlinear models. Even though, there are different optimization techniques used for parameter estimation of solar PV, still the best optimized results are not achieved to date. In this paper, Wind Driven Optimization (WDO) technique is proposed as the new method for identifying the parameters of solar PV. The accuracy and convergence time of the proposed method is compared with results of Pattern Search (PS), Genetic Algorithm (GA), and Simulated Annealing (SA) for single diode and double diode models of solar PV. Furthermore, for performance validation, the parameters obtained through WDO are compared with hybrid Bee Pollinator Flower Pollination Algorithm (BPFPA), Flower Pollination Algorithm (FPA), Generalized Oppositional Teaching Learning Based Optimization (GOTLBO), Artificial Bee Swarm Optimization (ABSO), and Harmony Search (HS). The obtained results clearly reveal that WDO algorithm can provide accurate optimized values with less number of iterations at different environmental conditions. Therefore, the WDO can be recommended as the best optimization algorithm for parameter estimation of solar PV

Desarrollo de formulaciones fito - cosméticas antioxidantes empleando como sustancia activa el extracto seco de Cinchona pubescens Vahl, Rubiaceae (Cascarilla)

This study aimed to assess the species Cinchona pubescens Vahl, known as "scale" as a raw material for cosmetics evaluating the properties and antioxidant components, both in solids, as in cosmetic formulations. The species is widely published in the Ecuadorian territory and its high adaptability has become an invasive species making relevant initiate investigations with a view to industrial use. The phenolic compound concentration in the extract and flavonoids were respectively 30 mg GAE / g Hyp 2 mg / g. Flavonoids characterized by the HP-TLC methodology were: apigenin, quercetin, kaempferol and catechin. The antioxidant activity of the extract and assessed by the DPPH ABTS spectrophotometric methods gave the following values: IC50 (DPPH) 0.0466 mg / mL and the IC50 (ABTS) 0.082 mg / ml. In cosmetic formulations evaluated by the methodology Fotoquimioluminiscencia a significantly increased antioxidant potential when compared to the base formula is observed, up to 15 times higher concentrations of the assay, in all cases (gel or cream), the behavior turned higher as compared to a positive pattern formulated with dry extract of Camellia sinensis.El presente estudio tuvo como finalidad valorar a la especie Cinchona pubescens Vahl, conocido como ―cascarilla‖ como una materia prima para la industria cosmética evaluando las propiedades y componentes antioxidantes, tanto en su extracto seco, como en formulaciones cosméticas. La especie se encuentra altamente difundida en el territorio Ecuatoriano y su alta adaptabilidad la ha convertido en una especie invasiva lo que hace relevante iniciar investigaciones con miras a su aprovechamiento industrial. La concentración de compuestos fenólicos y flavonoides en el extracto fueron respectivamente de, 30 mg GAE/g y 2 mg Hyp/g. Los flavonoides caracterizados por la metodología HP-TLC fueron: apigenina, quercetina, kaempferol y catequina. La actividad antioxidante del extracto evaluada por los métodos DPPH y ABTS espectrofotométricos dio los siguientes valores: IC50 (DPPH) 0,0466 mg/mL y el IC50 (ABTS) 0,082 mg/ml. En las formulaciones cosméticas evaluadas por la metodología de la Fotoquimioluminiscencia se observa un incremento significativo del potencial antioxidante al compararlo con la fórmula base, hasta de 15 veces para las concentraciones más elevadas del ensayo, en todos los casos (gel o crema), el comportamiento resulto mayor al compararlo con un patrón positivo formulado con extracto seco de Camellia sinensis

Serbian, Croatian and Spanish consumers' beliefs towards artisan cheese

Purpose: In the past two decades the popularity of artisan cheese emerged. The present study aimed to investigate similarities and differences in beliefs towards artisan cheeses among participants from Serbia, Croatia and Spain and to determine consumer profiles. Better understanding of their behaviours and beliefs could serve as the basis for the development of appropriate production and marketing strategies and for further popularisation of artisan cheeses. Design/methodology/approach: The data on demographic structure, behaviours and beliefs of 947 participants in total were obtained via a questionnaire collected online. In order to identify consumer profiles and to define their specific beliefs, a cross-country cluster analysis has been conducted. Four clusters were identified: “highly educated men”, “highly educated women”, “millennials” and “educated senior women”. Mann–Whitney U test was used to identify statistically significant differences between countries and clusters. Findings: Respondents from different countries had different preferences for cheese types and different ways of consumption. All participants valued artisan cheeses more than industrial cheeses in terms of healthiness and quality, but they believe that there is still much to be done in terms of proper packaging, labelling, branding, widening of assortment and providing better availability. The results of the present study revealed that participants had no clear opinion regarding trust in artisan cheese safety. Originality/value: Up to date, no study investigated beliefs of consumers from Serbia and Croatia towards artisan cheese. Original consumer pool has unique characteristics: they are far more oriented towards open markets and purchasing cheese directly from producers; they have different preferences towards cheese types and different consuming habits. Unique consumer characteristics provided original findings considering their beliefs.info:eu-repo/semantics/acceptedVersio

Short communication: Effect of different kefir grains on the attributes of kefir produced with milk from Costa Rica

Kefir is an artisanal product that is gaining scientific attention due to its increase in consumption attributed to its potential health benefits. The effect on the quality attributes of kefir grains of different origin (household and commercial) and preserved with different methods (drying and freezing) was evaluated to standardize a domestic and semi-industrial process. Chemical (protein, lactose. lactic acid, ethanol, and acetic acid) as well as microbial properties (total plate count and total yeast count) were monitored during the experiment. Results show a statistical difference between the kefir grains in terms of acetic acid and ethanol percentages, which leads to the conclusion that there is a difference in the microbial populations that produce these products. Lactic acid, protein, and lactose parameters are statistically the same as well as the growth in biomass and the total population of yeast. Our results suggest that both types of kefir grains maintain a similar performance and that their metabolic capabilities are stable throughout time (taking into account that the household grains have been productive for years), meaning that domestic or semi-industrial processes could be easily standardized.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET