33 research outputs found
Effective Dark Matter Model: Relic density, CDMS II, Fermi LAT and LHC
The Cryogenic Dark Matter Search recently announced the observation of two
signal events with a 77% confidence level. Although statistically inconclusive,
it is nevertheless suggestive. In this work we present a model-independent
analysis on the implication of a positive signal in dark matter scattering off
nuclei. Assuming the interaction between (scalar, fermion or vector) dark
matter and the standard model induced by unknown new physics at the scale
, we examine various dimension-6 tree-level induced operators and
constrain them using the current experimental data, e.g. the WMAP data of the
relic abundance, CDMS II direct detection of the spin-independent scattering,
and indirect detection data (Fermi LAT cosmic gamma-ray), etc. Finally, the LHC
reach is also explored
General Analysis of Antideuteron Searches for Dark Matter
Low energy cosmic ray antideuterons provide a unique low background channel
for indirect detection of dark matter. We compute the cosmic ray flux of
antideuterons from hadronic annihilations of dark matter for various Standard
Model final states and determine the mass reach of two future experiments
(AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron
detection over current bounds. We consider generic models of scalar, fermion,
and massive vector bosons as thermal dark matter, describe their basic features
relevant to direct and indirect detection, and discuss the implications of
direct detection bounds on models of dark matter as a thermal relic. We also
consider specific dark matter candidates and assess their potential for
detection via antideuterons from their hadronic annihilation channels. Since
the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we
find that antideuterons can be a good indirect detection channel for a variety
of thermal relic electroweak scale dark matter candidates, even when the rate
for direct detection is highly suppressed.Comment: 44 pages, 15 Figure
Pig-to-Nonhuman Primates Pancreatic Islet Xenotransplantation: An Overview
The therapy of type 1 diabetes is an open challenging problem. The restoration of normoglycemia and insulin independence in immunosuppressed type 1 diabetic recipients of islet allotransplantation has shown the potential of a cell-based diabetes therapy. Even if successful, this approach poses a problem of scarce tissue supply. Xenotransplantation can be the answer to this limited donor availability and, among possible candidate tissues for xenotransplantation, porcine islets are the closest to a future clinical application. Xenotransplantation, with pigs as donors, offers the possibility of using healthy, living, and genetically modified islets from pathogen-free animals available in unlimited number of islets. Several studies in the pig-to-nonhuman primate model demonstrated the feasibility of successful preclinical islet xenotransplantation and have provided insights into the critical events and possible mechanisms of immune recognition and rejection of xenogeneic islet grafts. Particularly promising results in the achievement of prolonged insulin independence were obtained with newly developed, genetically modified pigs islets able to produce immunoregulatory products, using different implantation sites, and new immunotherapeutic strategies. Nonetheless, further efforts are needed to generate additional safety and efficacy data in nonhuman primate models to safely translate these findings into the clinic
Comparative serology techniques for the diagnosis of Trypanosoma cruzi infection in a rural population from the state of Querétaro, Mexico
Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and “indeterminate” stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests
Natural environments, ancestral diets, and microbial ecology: is there a modern “paleo-deficit disorder”? Part I
Regeneration of mature dermis by transplanted particulate acellular dermal matrix in a rat model of skin defect wound
A hardware-efficient parallel architecture for real-time blob analysis based on run-length code
Large Animal Models of Diabetes
Safe and reliable large animal diabetes models are a key prerequisite for advanced preclinical studies on diabetes. Chemical induction is the standard model of diabetes in rodents but is often critiqued in higher animals due to reduced efficacy, relevant side effects, and inadequate mortality rate. In this chapter, we aim to describe both pharmacological and surgical approaches for reproducible and safe diabetes models in minipigs and primates. In addition, genetically modified pig models for diabetes research are described