Qualité microbiologique du lait cru ovin collecte dans la steppe centrale de l’Algérie

L’objectif de l’étude consiste à évaluer la qualité microbiologique du lait cru ovin collecté localement, en milieu steppique Algérien dans la région de Djelfa situé à 300 km au sud d’Alger. Au total 51 échantillons de lait ont été prélevés pour des fins analytiques. La contamination moyenne est de 2,3.107 cfu/mL pour la flore totale contre 1,1.105 pour les coliformes totaux et 1,5.104 pour les coliformes fécaux. Pour la flore fongique, les laits sont plus contaminés en levures qu’en moisissures (2,4.105 vs 3,4.103 germes/mL respectivement). Les Streptocoques fécaux sont détectés chez 43,14% des échantillons par contre E.coli n’est décelée que chez 17,65% des laits. Par ailleurs, 28% des prélèvements sont positifs vis-à-vis de Clostridium contre 9,8% pour Staphylococcus aureus. En revanche, tous les laits sont exempts de Salmonella. Pour ce qui est de la recherche des anticorps brucelliques, 13,73% des laits analysés sont positifs au Ring-test. La mauvaise qualité du lait reflète bien les conditions déplorables de production et la non-observance des bonnes pratiques hygiéniques lors de la traiteMots-clés : brebis, lait cru, qualité hygiénique, microorganismes pathogènes, Algérie.Microbiological quality of raw ewe’s milk in Algerian middle steppeThe objective of this study was to assess the microbiological quality of raw milk sheep collected in Algerian steppe. A total of 51 samples of bulk milk were examined. The results obtained show the unsatisfactory quality of milk analyzed. The average contamination is 2,3.107 cfu/ml for the total flora against 1,1.105 for total coliforms and 1,5.104 for fecal coliforms. For the fungal flora, milk is more contamined with yeast than fungi (2,4.105 vs 3,4.103 germes/ml respectively). Fecal streptococci were detected in 43,14% of the samples were E.coli is detected in 17,65% of the milk. In addition, 28% of samples are positive for Clostridium against 9,8% for Staphylococcus aureus. All milk are free from Salmonella. In terms of Brucella antibody, 13,73% of milk are ring test positive. The poor quality of milk reflects the deplorable conditions of production and non-observance of good hygiene practices during milking.Keywords : Ewe, Raw milk, Hygienic quality, Pathogens, Algeria

Conditions for Set Agreement with an Application to Synchronous Systems

The $k$-set agreement problem is a generalization of the consensus problem: considering a system made up of $n$ processes where each process proposes a value, each non-faulty process has to decide a value such that a decided value is a proposed value, and no more than $k$ different values are decided. While this problem cannot be solved in an asynchronous system prone to $t$ process crashes when $t \geq k$, it can always be solved in a synchronous system; $\lfloor \frac{t}{k} \rfloor +1$ is then a lower bound on the number of rounds (consecutive communication steps) for the non-faulty processes to decide. The {\it condition-based} approach has been introduced in the consensus context. Its aim was to both circumvent the consensus impossibility in asynchronous systems, and allow for more efficient consensus algorithms in synchronous systems. This paper addresses the condition-based approach in the context of the $k$-set agreement problem. It has two main contributions. The first is the definition of a framework that allows defining conditions suited to the $\ell$-set agreement problem. More precisely, a condition is defined as a set of input vectors such that each of its input vectors can be seen as ``encoding'' $\ell$ values, namely, the values that can be decided from that vector. A condition is characterized by the parameters $t$, $\ell$, and a parameter denoted $d$ such that the greater $d+\ell$, the least constraining the condition (i.e., it includes more and more input vectors when $d+\ell$ increases, and there is a condition that includes all the input vectors when $d+\ell>t$). The conditions characterized by the triple of parameters $t$, $d$ and $\ell$ define the class of conditions denoted ${\cal S}_t^{d,\ell}$, $0\leq d\leq t$, $1\leq \ell \leq n-1$. The properties of the sets ${\cal S}_t^{d,\ell}$are investigated, and it is shown that they have a lattice structure. The second contribution is a generic synchronous $k$-set agreement algorithm based on a condition $C\in {\cal S}_t^{d,\ell}$, i.e., a condition suitedto the $\ell$-set agreement problem, for $\ell \leq k$. This algorithm requires at most $\left\lfloor \frac{d-1+\ell}{k} \right\rfloor +1$ rounds when the input vector belongs to $C$, and $\left\lfloor \frac{t}{k} \right\rfloor +1$ rounds otherwise. (Interestingly, this algorithm includes as particular cases the classical synchronous $k$-set agreement algorithm that requires $\left\lfloor \frac{t}{k} \right\rfloor+1$ rounds (case $d=t$ and $\ell=1$), and the synchronous consensus condition-based algorithm that terminates in $d+1$ rounds when the input vector belongs to the condition, and in $t+1$ rounds otherwise (case $k=\ell=1$).

The Kuiper Belt and Other Debris Disks

We discuss the current knowledge of the Solar system, focusing on bodies in the outer regions, on the information they provide concerning Solar system formation, and on the possible relationships that may exist between our system and the debris disks of other stars. Beyond the domains of the Terrestrial and giant planets, the comets in the Kuiper belt and the Oort cloud preserve some of our most pristine materials. The Kuiper belt, in particular, is a collisional dust source and a scientific bridge to the dusty "debris disks" observed around many nearby main-sequence stars. Study of the Solar system provides a level of detail that we cannot discern in the distant disks while observations of the disks may help to set the Solar system in proper context.Comment: 50 pages, 25 Figures. To appear in conference proceedings book "Astrophysics in the Next Decade

Microarray Analysis of the Effect of Streptococcus equi subsp. zooepidemicus M-Like Protein in Infecting Porcine Pulmonary Alveolar Macrophage

Streptococcus equi subsp. zooepidemicus (S. zooepidemicus), which belongs to Lancefield group C streptococci, is an important pathogen of domesticated species, causing septicemia, meningitis and mammitis. M-like protein (SzP) is an important virulence factor of S. zooepidemicus and contributes to bacterial infection and antiphagocytosis. To increase our knowledge of the mechanism of SzP in infection, we profiled the response of porcine pulmonary alveolar macrophage (PAM) to infection with S. zooepidemicus ATCC35246 wild strain (WD) and SzP-knockout strain (KO) using the Roche NimbleGen Porcine Genome Expression Array. We found SzP contributed to differential expression of 446 genes, with upregulation of 134 genes and downregulation of 312 genes. Gene Ontology category and KEGG pathway were analyzed for relationships among differentially expressed genes. These genes were represented in a variety of functional categories, including genes involved in immune response, regulation of chemokine production, signal transduction and regulation of apoptosis. The reliability of the data obtained from the microarray was verified by performing quantitative real-time PCR on 12 representative genes. The data will contribute to understanding of SzP mediated mechanisms of S. zooepidemicus pathogenesis

C. albicans Colonization of Human Mucosal Surfaces

Background: Candida albicans is a low level commensal organism in normal human populations with the continuous potential to expand and cause a spectrum of clinical conditions. Methodology/Principal Findings: Using ex vivo human organ cultures and populations of primary human cells, we have developed several related experimental systems to examine early-stage interactions between C. albicans and mucosal surfaces. Experiments have been conducted both with exogenously added C. albicans and with overtly normal human mucosal surfaces supporting pre-existing infections with natural isolates of Candida. Under different culture conditions, we have demonstrated the formation of C. albicans colonies on human target cells and filament formation, equivalent to tissue invasion. Conclusions/Significance: These organ culture systems provide a valuable new resource to examine the molecular and cellular basis for Candida colonization of human mucosal surfaces

Prospects for the development of probiotics and prebiotics for oral applications

There has been a paradigm shift towards an ecological and microbial community-based approach to understanding oral diseases. This has significant implications for approaches to therapy and has raised the possibility of developing novel strategies through manipulation of the resident oral microbiota and modulation of host immune responses. The increased popularity of using probiotic bacteria and/or prebiotic supplements to improve gastrointestinal health has prompted interest in the utility of this approach for oral applications. Evidence now suggests that probiotics may function not only by direct inhibition of, or enhanced competition with, pathogenic micro-organisms, but also by more subtle mechanisms including modulation of the mucosal immune system. Similarly, prebiotics could promote the growth of beneficial micro-organisms that comprise part of the resident microbiota. The evidence for the use of pro or prebiotics for the prevention of caries or periodontal diseases is reviewed, and issues that could arise from their use, as well as questions that still need to be answered, are raised. A complete understanding of the broad ecological changes induced in the mouth by probiotics or prebiotics will be essential to assess their long-term consequences for oral health and disease

Binary systems and their nuclear explosions

Peer ReviewedPreprin

Light Element Isotopic Compositions of Cometary Matter Returned by the STARDUST Mission

Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild2 particle fragments, however extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Non-terrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is {sup 16}O-enriched like refractory inclusions in meteorites, suggesting formation in the hot inner solar nebula and large-scale radial transport prior to comet accretion in the outer solar system

Send more data: a systematic review of mathematical models of antimicrobial resistance

Abstract Background Antimicrobial resistance is a global health problem that demands all possible means to control it. Mathematical modelling is a valuable tool for understanding the mechanisms of AMR development and spread, and can help us to investigate and propose novel control strategies. However, it is of vital importance that mathematical models have a broad utility, which can be assured if good modelling practice is followed. Objective The objective of this study was to provide a comprehensive systematic review of published models of AMR development and spread. Furthermore, the study aimed to identify gaps in the knowledge required to develop useful models. Methods The review comprised a comprehensive literature search with 38 selected studies. Information was extracted from the selected papers using an adaptation of previously published frameworks, and was evaluated using the TRACE good modelling practice guidelines. Results None of the selected papers fulfilled the TRACE guidelines. We recommend that future mathematical models should: a) model the biological processes mechanistically, b) incorporate uncertainty and variability in the system using stochastic modelling, c) include a sensitivity analysis and model external and internal validation. Conclusion Many mathematical models of AMR development and spread exist. There is still a lack of knowledge about antimicrobial resistance, which restricts the development of useful mathematical models