379 research outputs found

    Microbiological quality control of a cage washing machine by means of a thin film culture system (PetrifilmTM)

    Get PDF
    Washing machine effectiveness is dependent on treatment of cage surface with hot water containing detergent. The temperature of the washing chamber will not reflect the degree of treatment of each individual cage. Bacteriological testing ofcage surface will give a true indication of residual contamination. This study describes the use of rehydratable contact films to harvest and culture residual bacteria. The method registers numbers of colonies retrieved from the surface. It does nottype the bacteria and is as such a non-specific method. The study reveals that the machine in question was effective and that no bacteria were found following a normal cycle. A machine breakdown was demonstrated before the mechanicalcause was uncovered

    Osos Pardos holocenos en trampas naturales: los yacimientos excepcionales de Mont Ventoux (Vaucluse, Francia)

    Get PDF
    [Abstract] On the northern face of the mountain Mont Ventoux (Vaucluse, Southeastern France), a dozen cavities and traps (called MV1, 2, 3, 4 ( = Aven du René-Jean), 5, 6 ...) have been recently discovered by speleologists, yielding rich Holocene faunal remains. Two sites (MV2 and MV4, figure 1) have been excavated for 3 years (1997-1999) and appear to be exceptional places for their archaeological records, containing both numerous remains of brown bears and charcoal. These remains seem to have been accumulated during a short time (Bronze Age ? to late Antiquity). Here are presented some results of our first field investigations. Although these do not strictly concern cave bears, they may be useful to paleontologists, archaeologists, taphonomists and biologists working on (Pleistocene) bears

    Evolution of an elliptical bubble in an accelerating extensional flow

    Get PDF
    Mathematical models that describe the dynamical behavior of a thin gas bubble embedded in a glass fiber during a fiber drawing process have been discussed and analyzed. The starting point for the mathematical modeling was the equations presented in [1] for a glass fiber with a hole undergoing extensional flow. These equations were reconsidered here with the additional reduction that the hole, i.e. the gas bubble, was thin as compared to the radius of the fiber and of finite extent. The primary model considered was one in which the mass of the gas inside the bubble was fixed. This fixed-mass model involved equations for the axial velocity and fiber radius, and equations for the radius of the bubble and the gas pressure inside the bubble. The model equations assumed that the temperature of the furnace of the drawing tower was known. The governing equations of the bubble are hyperbolic and predict that the bubble cannot extend beyond the limiting characteristics specified by the ends of the initial bubble shape. An analysis of pinch-off was performed, and it was found that pinch-off can occur, depending on the parameters of the model, due to surface tension when the bubble radius is small. In order to determine the evolution of a bubble, a numerical method of solution was presented. The method was used to study the evolution of two different initial bubble shapes, one convex and the other non-convex. Both initial bubble shapes had fore-aft symmetry, and it was found that the bubbles stretched and elongated severely during the drawing process. For the convex shape, fore-aft symmetry was lost in the middle of the drawing process, but the symmetry was re-gained by the end of the drawing tower. A small amount of pinch-off was observed at each end for this case, so that the final bubble length was slightly shorter than its theoretical maximum length. For the non-convex initial shape, pinch-off occurred in the middle of the bubble resulting in two bubbles by the end of the fiber draw. The two bubbles had different final pressures and did not have fore-aft symmetry. An extension of the fixed-mass model was considered in which the gas in the bubble was allowed to diffuse into the surrounding glass. The governing equations for this leaky-mass model were developed and manipulated into a form suitable for a numerical treatment

    Revisiting the S-matrix approach to the open superstring low energy effective lagrangian

    Full text link
    The conventional S-matrix approach to the (tree level) open string low energy effective lagrangian assumes that, in order to obtain all its bosonic α′N{\alpha'}^N order terms, it is necessary to know the open string (tree level) (N+2)(N+2)-point amplitude of massless bosons, at least expanded at that order in α′\alpha'. In this work we clarify that the previous claim is indeed valid for the bosonic open string, but for the supersymmetric one the situation is much more better than that: there are constraints in the kinematical bosonic terms of the amplitude (probably due to Spacetime Supersymmetry) such that a much lower open superstring nn-point amplitude is needed to find all the α′N{\alpha'}^N order terms. In this `revisited' S-matrix approach we have checked that, at least up to α′4{\alpha'}^4 order, using these kinematical constraints and only the known open superstring 4-point amplitude, it is possible to determine all the bosonic terms of the low energy effective lagrangian. The sort of results that we obtain seem to agree completely with the ones achieved by the method of BPS configurations, proposed about ten years ago. By means of the KLT relations, our results can be mapped to the NS-NS sector of the low energy effective lagrangian of the type II string theories implying that there one can also find kinematical constraints in the NN-point amplitudes and that important informations can be inferred, at least up to α′4{\alpha'}^4 order, by only using the (tree level) 4-point amplitude.Comment: 34 pages, 3 figure, Submitted on Aug 4, 2012, Published on Oct 15, 201

    CD24-targeted intraoperative fluorescence image-guided surgery leads to improved cytoreduction of ovarian cancer in a preclinical orthotopic surgical model

    Get PDF
    Background: The completeness of resection is a key prognostic indicator in patients with ovarian cancer, and the application of tumour-targeted fluorescence image-guided surgery (FIGS) has led to improved detection of peritoneal metastases during cytoreductive surgery. CD24 is highly expressed in ovarian cancer and has been shown to be a suit

    Analysis of chromosome positions in the interphase nucleus of Chinese hamster cells by laser-UV-microirradiation experiments

    Get PDF
    Unsynchronized cells of an essentially diploid strain of female Chinese hamster cells derived from lung tissue (CHL) were laser-UV-microirradiated (=257 nm) in the nucleus either at its central part or at its periphery. After 7–9 h postincubation with 0.5 mM caffeine, chromosome preparations were made in situ. Twenty-one and 29 metaphase spreads, respectively, with partial chromosome shattering (PCS) obtained after micro-irradiation at these two nuclear sites, were Q-banded and analyzed in detail. A positive correlation was observed between the frequency of damage of chromosomes and both their DNA content and length at metaphase. No significant difference was observed between the frequencies of damage obtained for individual chromosomes at either site of microirradiation. The frequency of joint damage of homologous chromosomes was low as compared to nonhomologous ones. Considerable variation was noted in different cells in the combinations of jointly shattered chromosomes. Evidence which justifies an interpretation of these data in terms of an interphase arrangement of chromosome territories is discussed. Our data strongly argue against somatic pairing as a regular event, and suggest a considerable variability of chromosome positions in different nuclei. However, present data do not exclude the possibility of certain non-random chromosomal arrangements in CHL-nuclei. The interphase chromosome distribution revealed by these experiments is compared with centromere-centromere, centromere-center and angle analyses of metaphase spreads and the relationship between interphase and metaphase arrangements of chromosomes is discussed

    Impaired immunomodulatory effects of seminal plasma may play a role in unexplained recurrent pregnancy loss: results of an in vitro study

    Get PDF
    Background: Seminal plasma contains signaling molecules capable of modulating the maternal immune environment to support implantation and pregnancy. Prior studies indicated that seminal plasma induces changes in gene transcription of maternal immune cells. Reduced immune suppressive capacity may lead to pregnancy loss. The aim of this study was to investigate the immunomodulating effects of seminal plasma on T cells and monocytes in the context of recurrent pregnancy loss (RPL).Methods: Female T cells and monocytes were incubated with seminal plasma of 20 males in unexplained RPL couples (RPL males) and of 11 males whose partners had ongoing pregnancies (control males). The effect of seminal plasma on messenger RNA (mRNA) expression of immune cells was measured. Levels of mRNA expression were related to key signaling molecules present in the seminal plasma. Agglomerative hierarchical cluster analysis was performed on seminal plasma expression profiles and on mRNA expression profiles. Results: Expression of CD25 and anti-inflammatory IL-10 by female T cells was significantly lower after stimulation with seminal plasma of RPL males compared to control males. Female monocytes treated with seminal plasma of RPL males showed an immune activation signature of relatively elevated HLA-DR expression. Expression of these T cell and monocyte components was particularly correlated with the amounts of TGF-beta and VEGF in the seminal plasma. Conclusion: Our findings indicate that seminal plasma has immunomodulating properties on female immune cells compatible with the induction of a more regulatory phenotype, which may be impaired in cases of unexplained RPL.Clinical epidemiolog

    Identification of distinct seminal plasma cytokine profiles associated with male age and lifestyle characteristics in unexplained recurrent pregnancy loss

    Get PDF
    Background: Seminal plasma contains a wide range of cytokines, chemokines and growth factors. Part of these signalling molecules assist in inducing a state of active maternal immune tolerance towards the fetus. Disbalances in seminal plasma content may contribute to pregnancy loss. This study investigated cytokine expression profiles in seminal plasma of male partners of couples with unexplained recurrent pregnancy loss (RPL) and the association with clinical and lifestyle characteristics, including smoking, alcohol consumption and body mass index (BMI). Methods: In the seminal plasma of 52 men who visited a specialised RPL clinic the levels of 25 pre-selected cytokines, chemokines and growth factors were measured by Bio-Plex assay or ELISA. Two-way hierarchical cluster analysis was performed. Identified patient clusters were compared on clinical and lifestyle characteristics. Results: Two distinct cytokine expression profiles in the seminal plasma were revealed by cluster analysis. Patient cluster I showed relatively higher levels of pro-inflammatory cytokines, including IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-12, IL-18 and TNF-alpha, compared to Patient cluster II. Men belonging to Patient cluster I were significantly older and had significantly more lifestyle risk factors compared to men in Patient cluster II. Conclusion: Cluster analysis suggested the existence of a less favourable pro-inflammatory cytokine expression profile, being present in part of men affected by RPL and associated with advanced male age and lifestyle risk factors. These findings may serve as a starting point for further research into underlying mechanisms and ultimately lead to novel diagnostic and therapeutic approaches for couples with RPL.Research into fetal development and medicin
    • …
    corecore