393 research outputs found

    A 6 year Geohelminth infection profile of children at high altitude in Western Nepal

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    <p>Abstract</p> <p>Background</p> <p>Geohelminth infections are a major problem of children from the developing countries. Children with these infections suffer from developmental impairments and other serious illnesses. This study aimed to measure the prevalence of geohelminth infection, infection intensity as well as the change in the intensity in children from Western Nepal over years.</p> <p>Methods</p> <p>This 6-year hospital based prospective study at the Manipal Teaching Hospital, Pokhara included children (< 15 years) visiting the hospital from Kaski and 7 surrounding districts. Samples were also collected from children in the community from different medical camps. Three stool samples from every child were processed using direct and concentration methods. The Kato-Katz technique was used for measuring the intensity of infection.</p> <p>Results</p> <p>The overall prevalence in hospital - attending children was 9.2% with 7.6% in preschool (0 – 5 y) and 11.0% in school-age (6 – 15 y) children, and in community 17.7% with 14.8% in pre-school and 20.5% in school-age children. <it>Ascaris lumbricoides</it>, <it>Trichuris trichiura</it>, <it>Ancylostoma deodenale </it>and <it>Strongyloides stercoralis </it>were the common geohelminths with a gradual decrease in worm load over the years. School-age children were found to be significantly more prone to geohelminth infection as compared to preschool children, but no statistical difference was detected by gender, district as well as season.</p> <p>Conclusion</p> <p>This heavy infection of geohelminths in children should be corrected by appropriate medication and maintaining strict personal hygiene. Health education, clean water, good sewage management and a congenial environment should be ensured to minimise infection.</p

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    Ly6Chi monocyte recruitment is responsible for Th2 associated host-protective macrophage accumulation in liver inflammation due to schistosomiasis

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    Accumulation of M2 macrophages in the liver, within the context of a strong Th2 response, is a hallmark of infection with the parasitic helminth, Schistosoma mansoni, but the origin of these cells is unclear. To explore this, we examined the relatedness of macrophages to monocytes in this setting. Our data show that both monocyte-derived and resident macrophages are engaged in the response to infection. Infection caused CCR2-dependent increases in numbers of Ly6Chi monocytes in blood and liver and of CX3CR1+ macrophages in diseased liver. Ly6Chi monocytes recovered from liver had the potential to differentiate into macrophages when cultured with M-CSF. Using pulse chase BrdU labeling, we found that most hepatic macrophages in infected mice arose from monocytes. Consistent with this, deletion of monocytes led to the loss of a subpopulation of hepatic CD11chi macrophages that was present in infected but not naïve mice. This was accompanied by a reduction in the size of egg-associated granulomas and significantly exacerbated disease. In addition to the involvement of monocytes and monocyte-derived macrophages in hepatic inflammation due to infection, we observed increased incorporation of BrdU and expression of Ki67 and MHC II in resident macrophages, indicating that these cells are participating in the response. Expression of both M2 and M1 marker genes was increased in liver from infected vs. naive mice. The M2 fingerprint in the liver was not accounted for by a single cell type, but rather reflected expression of M2 genes by various cells including macrophages, neutrophils, eosinophils and monocytes. Our data point to monocyte recruitment as the dominant process for increasing macrophage cell numbers in the liver during schistosomiasis

    Biodiversity on Broadway - Enigmatic Diversity of the Societies of Ants (Formicidae) on the Streets of New York City

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    Each year, a larger proportion of the Earth's surface is urbanized, and a larger proportion of the people on Earth lives in those urban areas. The everyday nature, however, that humans encounter in cities remains poorly understood. Here, we consider perhaps the most urban green habitat, street medians. We sampled ants from forty-four medians along three boulevards in New York City and examined how median properties affect the abundance and species richness of native and introduced ants found on them. Ant species richness varied among streets and increased with area but was independent of the other median attributes measured. Ant assemblages were highly nested, with three numerically dominant species present at all medians and additional species present at a subset of medians. The most common ant species were the introduced Pavement ant (Tetramorium caespitum) and the native Thief ant (Solenopsis molesta) and Cornfield ant (Lasius neoniger). The common introduced species on the medians responded differently to natural and disturbed elements of medians. Tetramorium caespitum was most abundant in small medians, with the greatest edge/area ratio, particularly if those medians had few trees, whereas Nylanderia flavipes was most abundant in the largest medians, particularly if they had more trees. Many of the species encountered in Manhattan were similar to those found in other large North American cities, such that a relatively small subset of ant species probably represent most of the encounters humans have with ants in North America

    Electrotonic Signals along Intracellular Membranes May Interconnect Dendritic Spines and Nucleus

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    Synapses on dendritic spines of pyramidal neurons show a remarkable ability to induce phosphorylation of transcription factors at the nuclear level with a short latency, incompatible with a diffusion process from the dendritic spines to the nucleus. To account for these findings, we formulated a novel extension of the classical cable theory by considering the fact that the endoplasmic reticulum (ER) is an effective charge separator, forming an intrinsic compartment that extends from the spine to the nuclear membrane. We use realistic parameters to show that an electrotonic signal may be transmitted along the ER from the dendritic spines to the nucleus. We found that this type of signal transduction can additionally account for the remarkable ability of the cell nucleus to differentiate between depolarizing synaptic signals that originate from the dendritic spines and back-propagating action potentials. This study considers a novel computational role for dendritic spines, and sheds new light on how spines and ER may jointly create an additional level of processing within the single neuron

    Acute appendicitis: transcript profiling of blood identifies promising biomarkers and potential underlying processes

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    Background The diagnosis of acute appendicitis can be surprisingly difficult without computed tomography, which carries significant radiation exposure. Circulating blood cells may carry informative changes in their RNA expression profile that would signal internal infection or inflammation of the appendix. Methods Genome-wide expression profiling was applied to whole blood RNA of acute appendicitis patients versus patients with other abdominal disorders, in order to identify biomarkers of appendicitis. From a large cohort of emergency patients, a discovery set of patients with surgically confirmed appendicitis, or abdominal pain from other causes, was identified. RNA from whole blood was profiled by microarrays, and RNA levels were filtered by a combined fold-change (\u3e2) and p value (\u3c0.05). A separate set of patients, including patients with respiratory infections, was used to validate a partial least squares discriminant (PLSD) prediction model. Results Transcript profiling identified 37 differentially expressed genes (DEG) in appendicitis versus abdominal pain patients. The DEG list contained 3 major ontologies: infection-related, inflammation-related, and ribosomal processing. Appendicitis patients had lower level of neutrophil defensin mRNA (DEFA1,3), but higher levels of alkaline phosphatase (ALPL) and interleukin-8 receptor-ß (CXCR2/IL8RB), which was confirmed in a larger cohort of 60 patients using droplet digital PCR (ddPCR). Conclusions Patients with acute appendicitis have detectable changes in the mRNA expression levels of factors related to neutrophil innate defense systems. The low defensin mRNA levels suggest that appendicitis patient’s immune cells are not directly activated by pathogens, but are primed by diffusible factors in the microenvironment of the infection. The detected biomarkers are consistent with prior evidence that biofilm-forming bacteria in the appendix may be an important factor in appendicitis

    Requirement of TORC1 for Late-Phase Long-Term Potentiation in the Hippocampus

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    Late-phase long-term potentiation (L-LTP) and long-term memory depend on the transcription of mRNA of CRE-driven genes and synthesis of proteins. However, how synaptic signals propagate to the nucleus is unclear. Here we report that the CREB coactivator TORC1 (transducer of regulated CREB activity 1) undergoes neuronal activity-induced translocation from the cytoplasm to the nucleus, a process required for CRE-dependent gene expression and L-LTP. Overexpressing a dominant-negative form of TORC1 or down-regulating TORC1 expression prevented activity-dependent transcription of CREB target genes in cultured hippocampal neurons, while overexpressing a wild-type form of TORC1 facilitated basal and activity-induced transcription of CREB target genes. Furthermore, overexpressing the dominant-negative form of TORC1 suppressed the maintenance of L-LTP without affecting early-phase LTP, while overexpressing the wild-type form of TORC1 facilitated the induction of L-LTP in hippocampal slices. Our results indicate that TORC1 is essential for CRE-driven gene expression and maintenance of long-term synaptic potentiation

    Search for Dark Matter and Supersymmetry with a Compressed Mass Spectrum in the Vector Boson Fusion Topology in Proton-Proton Collisions at root s=8 TeV

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    Search for dark matter produced in association with a single top quark or a top quark pair in proton-proton collisions at s=13 TeV

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    A search has been performed for heavy resonances decaying to ZZ or ZW in 2l2q final states, with two charged leptons (l = e, mu) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W' bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.A search has been performed for heavy resonances decaying to ZZ or ZW in 2l2q final states, with two charged leptons (l = e, mu) produced by the decay of a Z boson, and two quarks produced by the decay of a W or Z boson. The analysis is sensitive to resonances with masses in the range from 400 to 4500 GeV. Two categories are defined based on the merged or resolved reconstruction of the hadronically decaying vector boson, optimized for high- and low-mass resonances, respectively. The search is based on data collected during 2016 by the CMS experiment at the LHC in proton-proton collisions with a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). No excess is observed in the data above the standard model background expectation. Upper limits on the production cross section of heavy, narrow spin-1 and spin-2 resonances are derived as a function of the resonance mass, and exclusion limits on the production of W' bosons and bulk graviton particles are calculated in the framework of the heavy vector triplet model and warped extra dimensions, respectively.A search for dark matter produced in association with top quarks in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The data set used corresponds to an integrated luminosity of 35.9 fb(-1) recorded with the CMS detector at the LHC. Whereas previous searches for neutral scalar or pseudoscalar mediators considered dark matter production in association with a top quark pair only, this analysis also includes production modes with a single top quark. The results are derived from the combination of multiple selection categories that are defined to target either the single top quark or the top quark pair signature. No significant deviations with respect to the standard model predictions are observed. The results are interpreted in the context of a simplified model in which a scalar or pseudoscalar mediator particle couples to a top quark and subsequently decays into dark matter particles. Scalar and pseudoscalar mediator particles with masses below 290 and 300 GeV, respectively, are excluded at 95% confidence level, assuming a dark matter particle mass of 1 GeV and mediator couplings to fermions and dark matter particles equal to unity.Peer reviewe
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