Transient effects in the backscattered current of a Luttinger liquid

We study the backscattered current in a Luttinger liquid in the presence of a point like weak impurity switched on at finite time, taking into account finite-temperature effects. We show how the well-known results for a static impurity are distorted. We derive a dimensionless parameter $\tau_{R}$ as function of the electron-electron interaction and the temperature, such that for $\tau_{R} 1$) the switching process is relevant (irrelevant). Our results suggest the possibility of determining the value of the Luttinger parameter $K$ through time measurements in transport experiments at fixed voltage.Comment: 8 pages, 3 figures. To appear in Physical Review

APPLIED STUDY OF MICROBIOLOGICAL HAZARDS IN RAW MILK SOFT WHITE CHEESE IN EGYPT

Raw milk Domiati cheese is the main soft white pickled cheese produced in Egypt. The objective of this study was to assess the microbiological hazards, physiochemical quality and safety of some raw Domiati cheese subtypes including Double Cream, Tallaga, Baramely and Istanbully. The cheese samples were randomly collected from different cheese retailers in Cairo. The results indicated that the protein content and fat content were high in Double cream cheese. The pH value was low in Baramely cheese. Total solid, ash, and EC were high in Istanbully cheese because it is high salt level. Also, results indicated high microbiological hazards. the cheese samples were highly contaminated, having microbial load exceeding the acceptable limits such as: Total bacterial count, Total coliform, Fecal E. coli and yeast & molds. Pathogenic bacteria (Staphylococcus aureus, E. coli O157:H7, Salmonella sp., Shigella sp., Listeria monocytogenes, Bacillus cereus and Campylobacter jejuni) were detected in three cheese samples.  Except Istanbully cheese sample were found free of most pathogenic bacteria.  A high microbial load of the cheese samples present a public health hazard to the consumers and emphasize the need for improving hygienic standard. Microbiological hazards must be limited to the stander limit of food safety. Raw milk soft white cheese must be manufactured according to hygienic standard

Avaliação de método de colorimetria para dosagem de glicosaminoglicanos do líquido sinovial de equinos para detecção de doença degenerativa articular

O artigo não apresenta resumo

Emergence of terpene cyclization in Artemisia annua

The emergence of terpene cyclization was critical to the evolutionary expansion of chemical diversity yet remains unexplored. Here we report the first discovery of an epistatic network of residues that controls the onset of terpene cyclization in Artemisia annua. We begin with amorpha-4,11-diene synthase (ADS) and (E)-b-farnesene synthase (BFS), a pair of terpene synthases that produce cyclic or linear terpenes, respectively. A library of B27,000 enzymes is generated by breeding combinations of natural amino-acid substitutions from the cyclic into the linear producer. We discover one dominant mutation is sufficient to activate cyclization, and together with two additional residues comprise a network of strongly epistatic interactions that activate, suppress or reactivate cyclization. Remarkably, this epistatic network of equivalent residues also controls cyclization in a BFS homologue from Citrus junos. Fitness landscape analysis of mutational trajectories provides quantitative insights into a major epoch in specialized metabolism

Resultados da rede de ensaios cooperativos para a resistência à brusone da espiga de trigo (RECORBE), safras 2020 e 2021.

A brusone, causada pelo fungo Pyricularia oryzae Triticum, é uma das principais ameaças fitossanitárias que assolam as regiões tritícolas da América do Sul (Embrapa, 2019). Nesse sentido, existe um conjunto de medidas recomendadas que fazem parte do manejo integrado da brusone, as quais têm por objetivo controlar ou, ao menos, minimizar os efeitos dessa doença no campo. Entretanto, a eficiência das mesmas depende muito das condições climáticas pois, caso tais condições sejam favoráveis à doença, as possibilidades de manejo e de controle da brusone do trigo serão limitadas.ODS-