537 research outputs found

    Environmental monitoring of Mycobacterium bovis in badger feces and badger sett soil by real-time PCR, as confirmed by immunofluorescence, immunocapture, and cultivation

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    Real-time PCR was used to detect and quantify Mycobacterium bovis cells in naturally infected soil and badger faeces. Immunomagnetic capture, immunofluorescence and selective culture confirmed species identification and cell viability. These techniques will prove useful for monitoring M. bovis in the environment and for elucidating transmission routes between wildlife and cattle

    Mechanisms by which sialylated milk oligosaccharides impact bone biology in a gnotobiotic mouse model of infant undernutrition

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    Undernutrition in children is a pressing global health problem, manifested in part by impaired linear growth (stunting). Current nutritional interventions have been largely ineffective in overcoming stunting, emphasizing the need to obtain better understanding of its underlying causes. Treating Bangladeshi children with severe acute malnutrition with therapeutic foods reduced plasma levels of a biomarker of osteoclastic activity without affecting biomarkers of osteoblastic activity or improving their severe stunting. To characterize interactions among the gut microbiota, human milk oligosaccharides (HMOs), and osteoclast and osteoblast biology, young germ-free mice were colonized with cultured bacterial strains from a 6-mo-old stunted infant and fed a diet mimicking that consumed by the donor population. Adding purified bovine sialylated milk oligosaccharides (S-BMO) with structures similar to those in human milk to this diet increased femoral trabecular bone volume and cortical thickness, reduced osteoclasts and their bone marrow progenitors, and altered regulators of osteoclastogenesis and mediators of Th2 responses. Comparisons of germ-free and colonized mice revealed S-BMO-dependent and microbiota-dependent increases in cecal levels of succinate, increased numbers of small intestinal tuft cells, and evidence for activation of a succinate-induced tuft cell signaling pathway linked to Th2 immune responses. A prominent fucosylated HMO, 2'-fucosyllactose, failed to elicit these changes in bone biology, highlighting the structural specificity of the S-BMO effects. These results underscore the need to further characterize the balance between, and determinants of, osteoclastic and osteoblastic activity in stunted infants/children, and suggest that certain milk oligosaccharides may have therapeutic utility in this setting

    Algebraic Bethe ansatz for the gl(1|2) generalized model II: the three gradings

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    The algebraic Bethe ansatz can be performed rather abstractly for whole classes of models sharing the same RR-matrix, the only prerequisite being the existence of an appropriate pseudo vacuum state. Here we perform the algebraic Bethe ansatz for all models with 9×99 \times 9, rational, gl(1|2)-invariant RR-matrix and all three possibilities of choosing the grading. Our Bethe ansatz solution applies, for instance, to the supersymmetric t-J model, the supersymmetric UU model and a number of interesting impurity models. It may be extended to obtain the quantum transfer matrix spectrum for this class of models. The properties of a specific model enter the Bethe ansatz solution (i.e. the expression for the transfer matrix eigenvalue and the Bethe ansatz equations) through the three pseudo vacuum eigenvalues of the diagonal elements of the monodromy matrix which in this context are called the parameters of the model.Comment: paragraph added in section 3, reference added, version to appear in J.Phys.

    Integrable multiparametric quantum spin chains

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    Using Reshetikhin's construction for multiparametric quantum algebras we obtain the associated multiparametric quantum spin chains. We show that under certain restrictions these models can be mapped to quantum spin chains with twisted boundary conditions. We illustrate how this general formalism applies to construct multiparametric versions of the supersymmetric t-J and U models.Comment: 17 pages, RevTe

    Specialist nursing and community support for the carers of people with dementia living at home: an evidence synthesis.

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    Specialist nurses are one way of providing support for family carers of people with dementia, but relatively little is known about what these roles achieve, or if they are more effective than roles that do not require a clinical qualification. The aim of this review was to synthesise the literature on the scope and effectiveness of specialist nurses, known as Admiral Nurses, and set this evidence in the context of other community-based initiatives to support family carers of people with dementia. We undertook a systematic review of the literature relating to the scope and effectiveness of Admiral Nurses and a review of reviews of interventions to support the family carers of people with dementia. To identify studies, we searched electronic databases, undertook lateral searches and contacted experts. Searches were undertaken in November 2012. Results are reported narratively with key themes relating to Admiral Nurses identified using thematic synthesis. We included 33 items relating to Admiral Nurses (10 classified as research) and 11 reviews evaluating community-based support for carers of people with dementia. There has been little work to evaluate specific interventions provided by Admiral Nurses, but three overarching thematic categories were identified: (i) relational support, (ii) co-ordinating and personalising support and (iii) challenges and threats to the provision of services by Admiral Nurses. There was an absence of clearly articulated goals and service delivery was subject to needs of the host organisation and the local area. The reviews of community-based support for carers of people with dementia included 155 studies but, in general, evidence that interventions reduced caregiver depression or burden was weak, although psychosocial and educational interventions may reduce depression in carers. Community support for carers of people with dementia, such as that provided by Admiral Nurses, is valued by family carers, but the impact of such initiatives is not clearly established

    Serial Analysis of the Gut and Respiratory Microbiome in Cystic Fibrosis in Infancy: Interaction between Intestinal and Respiratory Tracts and Impact of Nutritional Exposures

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    Pulmonary damage caused by chronic colonization of the cystic fibrosis (CF) lung by microbial communities is the proximal cause of respiratory failure. While there has been an effort to document the microbiome of the CF lung in pediatric and adult patients, little is known regarding the developing microflora in infants. We examined the respiratory and intestinal microbiota development in infants with CF from birth to 21 months. Distinct genera dominated in the gut compared to those in the respiratory tract, yet some bacteria overlapped, demonstrating a core microbiota dominated by Veillonella and Streptococcus. Bacterial diversity increased significantly over time, with evidence of more rapidly acquired diversity in the respiratory tract. There was a high degree of concordance between the bacteria that were increasing or decreasing over time in both compartments; in particular, a significant proportion (14/16 genera) increasing in the gut were also increasing in the respiratory tract. For 7 genera, gut colonization presages their appearance in the respiratory tract. Clustering analysis of respiratory samples indicated profiles of bacteria associated with breast-feeding, and for gut samples, introduction of solid foods even after adjustment for the time at which the sample was collected. Furthermore, changes in diet also result in altered respiratory microflora, suggesting a link between nutrition and development of microbial communities in the respiratory tract. Our findings suggest that nutritional factors and gut colonization patterns are determinants of the microbial development of respiratory tract microbiota in infants with CF and present opportunities for early intervention in CF with altered dietary or probiotic strategies

    Electromagnetic waves in a wormhole geometry

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    We investigate the propagation of electromagnetic waves through a static wormhole. It is shown that the problem can be reduced to a one-dimensional Schr\"odinger-like equation with a barrier-type potential. Using numerical methods, we calculate the transmission coefficient as a function of the energy. We also discuss the polarization of the outgoing radiation due to this gravitational scattering.Comment: LaTex file, 5 pages, 2 figures, one reference added, accepted for publication in PR

    An mRNA Blueprint for C-4 Photosynthesis Derived from Comparative Transcriptomics of Closely Related C-3 and C-4 Species

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    Bräutigam A, Kajala K, Wullenweber J, et al. An mRNA Blueprint for C-4 Photosynthesis Derived from Comparative Transcriptomics of Closely Related C-3 and C-4 Species. Plant Physiology. 2011;155(1):142-156.C-4 photosynthesis involves alterations to the biochemistry, cell biology, and development of leaves. Together, these modifications increase the efficiency of photosynthesis, and despite the apparent complexity of the pathway, it has evolved at least 45 times independently within the angiosperms. To provide insight into the extent to which gene expression is altered between C-3 and C-4 leaves, and to identify candidates associated with the C-4 pathway, we used massively parallel mRNA sequencing of closely related C-3 (Cleome spinosa) and C-4 (Cleome gynandra) species. Gene annotation was facilitated by the phylogenetic proximity of Cleome and Arabidopsis (Arabidopsis thaliana). Up to 603 transcripts differ in abundance between these C-3 and C-4 leaves. These include 17 transcription factors, putative transport proteins, as well as genes that in Arabidopsis are implicated in chloroplast movement and expansion, plasmodesmatal connectivity, and cell wall modification. These are all characteristics known to alter in a C-4 leaf but that previously had remained undefined at the molecular level. We also document large shifts in overall transcription profiles for selected functional classes. Our approach defines the extent to which transcript abundance in these C-3 and C-4 leaves differs, provides a blueprint for the NAD-malic enzyme C-4 pathway operating in a dicotyledon, and furthermore identifies potential regulators. We anticipate that comparative transcriptomics of closely related species will provide deep insight into the evolution of other complex traits
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