844 research outputs found

    Mikroorganizmi koji izazivaju kvar vakuum pakovanih viršli i uticaj na rast Listeria monocytogenes

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    Spoilage microflora present on vacuum packaged frankfurters is in most cases, result of post processing contamination, at the same time this is the primary cause of contamination with Listeria monocytogenes. Since spoilage organisms are present in the same environment as a pathogen, the aim was to determine their microbial interference. Approximately 100 CFU/cm2 of a five-strain mixture of L. monocytogenes was co inoculated onto frankfurters with different concentrations (103 and 106 CFU/cm2) of spoilage microflora (bacteria from genera Lactobacillus, Bacillus, Micrococcus, and Hafnia). The frankfurters were vacuum packaged and stored at 10°C for up to 48 days. The spoilage microflora that developed during storage consisted predominantly of lactic acid bacteria. The growth of mesophilic aerobic bacteria and LAB was very similar, with populations reaching 8.0 log CFU/cm2 within 24 days and final population of >9 log CFU/cm2 within 48 days. The presence of spoilage microflora extended the lag phase of L. monocytogenes until 24 days and significantly decreased pathogen level to 4 and 3 log CFU/cm2, in samples inoculated with initial concentration 103 CFU/cm2 and 106 CFU/cm2 of spoilage microflora, respectively. L. monocytogenes populations were significantly higher (P lt 0.05) in the reference sample (no spoilage microflora) and reached a maximum population of 5.9 log CFU/cm2 after 34 days. These results imply that competing microorganisms present on the processed meat may inhibit the growth of L. monocytogenes in the package.Proizvodi od mesa, uključujući ready-to-eat (RTE) proizvode kao što su viršle, povezani su sa pojavom oboljenja listerioze. Do kontaminacije ovih proizvoda patogenom bakterijom Listeria monocytogenes najčešće dolazi nakon proizvodnje i primenjenog termičkog tretmana a pre pakovanja. S ozirom da se mnogi od ovih proizvoda mogu konzumirati bez ponovnog zagrevanja mogu biti uzrok listerioze. Imajuću u vidu činjenicu da su u vakuum pakovanim viršlama prisutni i mikroorganizmi koji mogu izazivati kvar, cilj je bio da se ispita njihov međusobni uticaj. Viršle su inokulisane mešavinom pet sojeva L. monocytogenes u koncentraciji 100 CFU/cm2 i različitim koncentracijama bakterija koje pripadaju rodovima Lactobacillus, Bacillus, Micrococcus i Hafnia. Viršle su, zatim vakuum pakovane i skladištene na 10°C 48 dana. U odsustvu kompetitivnih bakterija, patogena bakterija L. monocytogenes je dostigla maksimalnu koncentraciju od 5.9 log CFU/cm2 i imala lag fazu koja je iznosila 7 dana. Ovi podaci doprinose činjenici da vakuum pakovane viršle čine veoma dobru sredinu za rast i preživljavanje L. monocytogenes. Mikroflora koja se razvijala tokom skladištenja se uglavnom sastojala od bakterija mlečne kiseline čiji je razvoj bio vrlo sličan razvoju mezofilne aerobne mikroflora, i dostizao maksimalnu populaciju >9 log CFU/cm2. Prisustvo ove mikroflore je produžilo lag fazu L. monocytogenes do 24 dana i značajno smanjilo broj patogena do 4 odn. 3 log CFU/cm2, u uzorcima koji su inokulisani početnom koncentracijom 103 CFU/cm2 odnosno 106 CFU/cm2 bakterija kvara. Ovi rezultati ukazuju da kompetitivna mikroflora može inhibirati rast L. monocytogenes na proizvodima od mesa u vakuum pakovanju

    Perverse coherent t-structures through torsion theories

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    Bezrukavnikov (later together with Arinkin) recovered the work of Deligne defining perverse tt-structures for the derived category of coherent sheaves on a projective variety. In this text we prove that these tt-structures can be obtained through tilting torsion theories as in the work of Happel, Reiten and Smal\o. This approach proves to be slightly more general as it allows us to define, in the quasi-coherent setting, similar perverse tt-structures for certain noncommutative projective planes.Comment: New revised version with important correction

    Recollements of Module Categories

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    We establish a correspondence between recollements of abelian categories up to equivalence and certain TTF-triples. For a module category we show, moreover, a correspondence with idempotent ideals, recovering a theorem of Jans. Furthermore, we show that a recollement whose terms are module categories is equivalent to one induced by an idempotent element, thus answering a question by Kuhn.Comment: Comments are welcom

    Biplane double-supported screw fixation (F-technique): a method of screw fixation at osteoporotic fractures of the femoral neck

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    The present work introduces a method of screw fixation of femoral neck fractures in the presence of osteoporosis, according to an original concept of the establishment of two supporting points for the implants and their biplane positioning in the femoral neck and head. The provision of two steady supporting points for the implants and the highly increased (obtuse) angle at which they are positioned allow the body weight to be transferred successfully from the head fragment onto the diaphysis, thanks to the strength of the screws, with the patient’s bone quality being of least importance. The position of the screws allows them to slide under stress with a minimal risk of displacement. The method was developed in search of a solution for those patients for whom primary arthroplasty is contraindicated. The method has been analysed in relation to biomechanics and statics. For the first time, a new function is applied to a screw fixation—the implant is presented as a simple beam with an overhanging end

    Five fathers' experience of an adult son sustaining a cervical spinal cord injury: an Interpretative Phenomenological Analysis

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    The paper presents an in-depth idiographic study exploring the experience of fathers who have an adult son with a cervical spinal cord injury (SCI). Five participants were recruited and individual semi-structured interviews were conducted. The interviews were transcribed verbatim and analysed using Interpretative Phenomenological Analysis (IPA). Two super-ordinate themes are presented highlighting. Firstly, the ongoing negative impact of their sons’ injury on the participants’ role as fathers’. This comprises the negative impact on emotions with guilt common for failing in their perceived role as a father. The dissonance experienced between wanting to help encourage their sons’ independence. Concern experienced due to their sons altered life trajectory and anxiety because they won’t be alive to protect their son in the future. Secondly, how participants cope and adjust to their son’s SCI are presented. Comprising of how positive thinking, such as focusing on their son surviving the trauma; and the influence of seeing their son cope well affects how participants cope. Also, reflecting on how the injury has changed their life helps participants, to an extent, make sense of the trauma. The results are discussed in relation to the relevant extant literature to give a unique perspective about how SCI impacts their perceived role as fathers and the struggle to cope and adjust to the trauma. Future research investigating the impact of SCI on the family is warranted to better understand the wider implications

    Geographic Coincidence of Increased Malaria Transmission Hazard and Vulnerability Occurring at the Periphery of two Tanzanian Villages.

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    The goal of malaria elimination necessitates an improved understanding of any fine-scale geographic variations in transmission risk so that complementary vector control tools can be integrated into current vector control programmes as supplementary measures that are spatially targeted to maximize impact upon residual transmission. This study examines the distribution of host-seeking malaria vectors at households within two villages in rural Tanzania. Host-seeking mosquitoes were sampled from 72 randomly selected households in two villages on a monthly basis throughout 2008 using CDC light-traps placed beside occupied nets. Spatial autocorrelation in the dataset was examined using the Moran's I statistic and the location of any clusters was identified using the Getis-Ord Gi* statistic. Statistical associations between the household characteristics and clusters of mosquitoes were assessed using a generalized linear model for each species. For both Anopheles gambiae sensu lato and Anopheles funestus, the density of host-seeking females was spatially autocorrelated, or clustered. For both species, houses with low densities were clustered in the semi-urban village centre while houses with high densities were clustered in the periphery of the villages. Clusters of houses with low or high densities of An. gambiae s.l. were influenced by the number of residents in nearby houses. The occurrence of high-density clusters of An. gambiae s.l. was associated with lower elevations while An. funestus was also associated with higher elevations. Distance from the village centre was also positively correlated with the number of household occupants and having houses constructed with open eaves. The results of the current study highlight that complementary vector control tools could be most effectively targeted to the periphery of villages where the households potentially have a higher hazard (mosquito densities) and vulnerability (open eaves and larger households) to malaria infection

    Seawater Acidification and Elevated Temperature Affect Gene Expression Patterns of the Pearl Oyster Pinctada fucata

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    Oceanic uptake of anthropogenic carbon dioxide results in decrease in seawater pH and increase in temperature. In this study, we demonstrated the synergistic effects of elevated seawater temperature and declined seawater pH on gene expression patterns of aspein, calmodulin, nacrein, she-7-F10 and hsp70 in the pearl oyster Pinctada fucata. Under ‘business-as-usual’ scenarios, four treatments were examined: (1) ambient pH (8.10) and ambient temperature (27°C) (control condition), (2) ambient pH and elevated temperature (+3°C), (3) declined pH (7.70) and ambient temperature, (4) declined pH and elevated temperature. The results showed that under warming and acidic seawater conditions, expression of aspein and calmodulin showed no significant differences among different time point in condition 8.10 T. But the levels of aspein and calmodulin in conditions 8.10 T+3, 7.70 T and 7.70 T+3, and levels of nacrein, she-7-F10 in all the four treatments changed significantly. Low pH and pH×temperature interaction influenced the expression of aspein and calmodulin significantly after hours 48 and 96. Significant effects of low pH and pH×temperature interaction on the expression of nacrein were observed at hour 96. The expression level of she-7-F10 was affected significantly by pH after hours 48 and 96. The expression of hsp70 was significantly affected by temperature, pH, temperature×pH interaction at hour 6, and by temperature×pH interaction at hour 24. This study suggested that declined pH and pH×temperature interaction induced down regulation of calcification related genes, and the interaction between declined seawater pH and elevated temperature caused up regulation of hsp70 in P. facata. These results demonstrate that the declined seawater pH and elevated temperature will impact the physiological process, and potentially the adaptability of P. fucata to future warming and acidified ocean

    Follicular fluid levels of vascular endothelial growth factor and early corpus luteum function during assisted reproductive technology cycles

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    BACKGROUND: The relation between vascular endothelial growth factor (VEGF) and early luteal function has rarely been proven in humans. The purpose of this study was to define the relation between follicular fluid concentrations of VEGF (FF VEGF) and early luteal function at the preimplantation stage during assisted reproductive technology (ART) cycles. METHODS: 71 women were divided into two groups, based on reproductive outcome: women who became pregnant after embryo transfer (ET) (n = 18, Group A) and non-pregnant women (n = 53, Group B). Serum progesterone (Se P) and inhibin A on ET day, and FF VEGF levels were measured in all women. Data were expressed as mean ± standard deviation. Statistical analysis was performed using Excel Office 98 for Student's t-test, linear regression test and chi-square test. A p value of < 0.05 was considered statistically significant. RESULTS: The groups were comparable for age, ovarian reserve, number and quality of the oocytes retrieved and of the embryos obtained and transferred. FF VEGF levels were increased (4235 ± 1433 vs 3432 ± 1231 pg/ml), while Se P and inhibin A levels were significantly reduced (83.1 ± 34.1 vs 112.0 ± 58.8 ng/ml and 397.4 ± 223 vs 533.5 ± 283 pg/ml, respectively) in the non-pregnant group and were negatively correlated with FF VEGF (r = -0.482, p < 0.05; r = -0.468, p < 0.05) only in pregnant women. CONCLUSION: Much has to be learned about the regulation and role of VEGF during the early luteal phase. We advance the hypothesis that the existence of a negative correlation between FF VEGF/Se P and FF VEGF/inhibin A in pregnant women might indicate the existence of a normal VEGF-mediated paracrine response when Se P and inhibin A levels are decreased. Excess production of FF VEGF and the absence of a correlation between FF VEGF/Se P and FF VEGF/inhibin A in non-pregnant women may be a paracrine reaction to immature luteal vasculature, resulting in luteal dysfunction

    Measurement of the Relative Branching Fraction of Υ(4S)\Upsilon(4S) to Charged and Neutral B-Meson Pairs

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    We analyze 9.7 x 10^6 B\bar{B}$ pairs recorded with the CLEO detector to determine the production ratio of charged to neutral B-meson pairs produced at the Y(4S) resonance. We measure the rates for B^0 -> J/psi K^{(*)0} and B^+ -> J/psi K^{(*)+} decays and use the world-average B-meson lifetime ratio to extract the relative widths f+-/f00 = Gamma(Y(4S) -> B+B-)/Gamma(Y(4S) -> B0\bar{B0}) = = 1.04 +/- 0.07(stat) +/- 0.04(syst). With the assumption that f+- + f00 = 1, we obtain f00 = 0.49 +/- 0.02(stat) +/- 0.01(syst) and f+- = 0.51 +/- 0.02(stat) +/- 0.01(syst). This production ratio and its uncertainty apply to all exclusive B-meson branching fractions measured at the Y(4S) resonance.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN
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