8,912 research outputs found
New method for non-standard invisible particle searches in tau lepton decays
Motivated by models proposed to explain the Standard Model anomalies, and the
unprecedented data to be collected by the Belle~II
experiment during the next years, we study the kinematics of tau pair decays
and propose a new method to search for lepton flavor violating processes in tau
lepton decays to invisible beyond Standard Model particles, such as , where is either an electron or a muon, and is a
massive particle that escapes undetected. The new method improves by one order
of magnitude the expected upper limit on the production
in 3x1 prong tau decays and establishes the possibility of performing this
search in 1x1 prong tau decays which has not been previously considered.Comment: 6 pages, 7 figure
Meta-analysis of a very low proportion through adjusted wald confidence intervals
In this paper we will discuss the meta-analysis of one low proportion. It is well known, that there are
several methods to perform the meta-analysis of one proportion, based on a linear combination of
proportions or transformed proportions. However, in the context of a linear combination of binomial
proportions has been proposed some approximate estimators with some improvements on low
proportion estimation. In this paper we will show, with a simple adaptation, the possible contribution
of several approximate adjusted Wald confidence intervals (CIs) for the meta-analysis of proportions. In
the context of low proportions, a simulation study scenario is carried out to compare these CIs amongst
themselves and with other available methods with respect to bias and coverage probabilities, using the
fixed effect or the random-effects model. Pointing our interest in rare events (analogous for the abundant
events) and taking into account the prevalence estimation of the Methicillin-resistant Staphylococcus
aureus with mecc gene, we discuss the choice of the meta-analysis methods on this low proportion. The
default meta-analysis methods of meta-analysis software programs are not always the best choice, in
particular to the meta-analysis of one low proportion, where the methods including the adjusted Wald
can outperform.publishe
Use of Prebiotics as an Alternative to Antibiotic Growth Promoters in the Poultry Industry
Nowadays there is a great concern about antimicrobial resistance (AMR), which has been recognized as one of the most serious global public health threats. Multilateral organizations focused on global health accept the use of antibiotics in animal production as one of the main drivers of AMR, so that many strategies to control this problem have been proposed, resulting in the total ban of antibiotics as growth-promoting agents. On the other hand, this ban has led to an increase in the incidence of bacterial infections or even to the use of antibiotics at therapeutic doses, which could cause a worse scenario of bacterial resistance. Poultry is one of the most commonly exploited species worldwide and a sector that continues to grow and industrialize in many parts of the world, so it was to be expected that a large part of the antibiotics used in animal production was destined to this industry. The reduction or complete abolition of antibiotics in poultry production would have a positive effect in the control of AMR, but this would also have negative economic and public health repercussions, caused by foodborne pathogens and the decrease of the productive parameters. For that, many specific alternatives have been evaluated and marketed, prebiotics being one of the most promising alternatives for the poultry industry
The Use of Probiotics in Poultry Production for the Control of Bacterial Infections and Aflatoxins
In intensive poultry production, a large number of antimicrobials are frequently employed to prevent (prophylactic use) and treat (therapeutic use) diseases, as well as for growth promotion (subtherapeutic use), in order to increase productivity. However, it has been reported that the use of antimicrobials at subtherapeutic doses is closely related to the increase in bacterial resistance and with the treatment failure. In addition to antimicrobial resistance, another problem derived from the use of antimicrobials is the presence of residues in animal products. Therefore, these problems and the ban of antimicrobial as growth promoters have prompted the poultry industry to look for alternatives with similar benefits to antibiotics. Among these alternatives, probiotics are one of the most widely studied and interesting groups. Hence, in the present chapter, the effect of probiotics and direct-fed microbial against foodborne pathogens and mycotoxins will be summarized
Control of Aflatoxicosis in Poultry Using Probiotics and Polymers
An important approach to prevent aflatoxicosis in poultry is the addition of non-nutritional adsorbents in the diet to bind aflatoxin B1 (AFB1) in the gastrointestinal tract. These adsorbents are large molecular weight compounds that are able to bind the mycotoxin, forming a stable complex adsorbent-mycotoxin, which can pass through the gastrointestinal tract. In this chapter, we evaluate the use of polymers and probiotics to reduce AFB1 toxic effects in poultry. Our results on the efficacy of polymers and probiotics in sequestering mycotoxins are highly promising, although this field is still in its infancy and further research is needed. Furthermore, in vivo studies are needed to confirm the effectiveness of these materials against AFB1 toxic effects, since results in the past have indicated that there is great variability in the efficacy of adsorbing materials in vivo, even though the compounds may show potential adsorption capacity of the mycotoxin in vitro
Chitoneous Materials for Control of Foodborne Pathogens and Mycotoxins in Poultry
Public concern with the incidence of antibiotic-resistant bacteria, particularly among foodborne pathogens has been challenging the poultry industry to find alternative means of control. Chitosan is a modified, natural biopolymer derived by deacetylation of chitin. The antimicrobial activity and film-forming property of chitosan makes it a potential source of food preservative or coating material of natural origin for improvement of quality and shelf life of various foods of agriculture, poultry, beef and seafood origin. In addition to its use as an antimicrobial, it has been shown that it has good properties as a mycotoxin adsorbent. The purposes of the present chapter is to summarize our experience using chitin-chitosan from Deacetylated 95% food grade chitosan (Paragon Specialty Products LLC Rainsville, AL) or Aspergillus oryzae meal (Fermacto®, PetAg Inc., Hampshire IL) to control foodborne pathogens, improve performance, biological sanitizer and mycotoxin binder in commercial poultry
Production of Aspergillus niger GH1 tannase using solid-state fermentation
The production of tannase by Aspergillus niger GH1 in solid-state fermentation (SSF) was evaluated.
Several concentrations of tannic acid (12.5, 25, 50 and 100 g/L) were tested in a model culture system. Column
reactors were packed with polyurethane foam impregnated with liquid medium and inoculated with fungal
spores. Tannase production was kinetically monitored by 48 h. Tannic acid uptake was spectrophotometrically
measured and extracellular and intracellular tannase activities were assayed by HPLC-chromatography.
Tannase activity increased with increasing concentration of tannic acid. Maximum extracellular and
intracellular tannase activities (11.35 and 6.95 U/mL respectively) were recorded with 100 g/L of tannic acid.
The substrate uptake was 100% at concentrations of 12.5, 25 and 50 g/L, while 74.4% was consumed in the
presence of 100 g/L of tannic acid after 48 h of culture. These results suggest that high concentrations of
tannins can be removed by SSF and tannase production can be reached in high levels.The present work was performed as part of a cooperative agreement between the Universidad Autonoma de Coahuila (UAdeC, Mexico) and the Universidade do Minho (UM, Portugal) within a specific international exchange program (VALNATURA project, alfa network from European Union) undertaken at the Biological Engineering Department (UM, Portugal) M A Cruz-Hernandez thanks to Concejo nacional de Ciencia y Tecnologia (CONACYT) the fellowship to study the doctoral program at the Department of Biotechnology (UAdeC
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