176 research outputs found

    NEC FUTURE Tier I Scoping Process: Public Comment

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    Utilizing its special expertise, the Regional Transportation Planning and High Speed Rail Research Group at the Massachusetts Institute of Technology (MIT) sought to provide input via public comment to the NEC FUTURE Tier I scoping process. Earlier in 2012, we completed a comprehensive look at the complexities and challenges associated with mobility in the NEC. This submittal is based on a report prepared for and funded by the Institute for Transportation Policy Studies (ITPS) in Tokyo, Japan, entitled Transportation in the Northeast Corridor of the U.S.: A Multimodal and Intermodal Conceptual Framework. We applied novel combinations of system analysis methods to seek new insights for planning in this corridor. With the lessons learned from this account, we seek to provide input to the NEC FUTURE scoping process, and enrich the NEC FUTURE Tier I EIS study. We recognize that the Purpose and Need and a comprehensive and carefully articulated range of alternatives are of utmost importance for the EIS process, and we are focusing our comments in these two areas. With our lessons learned, we hope to offer insights useful in formulating and refining the project’s Purpose and Need, and as well in defining the alternatives to be considered

    Neuropilin-1 mediates vascular permeability independently of vascular endothelial growth factor receptor-2 activation

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    Neuropilin-1 (NRP1) regulates developmental and pathological angiogenesis, arteriogenesis, and vascular permeability, acting as a coreceptor for semaphorin 3A (Sema3A) and the 165–amino acid isoform of vascular endothelial growth factor A (VEGF-A165). NRP1 is also the receptor for the CendR peptides, a class of cell- and tissue-penetrating peptides with a specific R-x-x-R carboxyl-terminal motif. Because the cytoplasmic domain of NRP1 lacks catalytic activity, NRP1 is mainly thought to act through the recruitment and binding to other receptors. We report here that the NRP1 intracellular domain mediates vascular permeability. Stimulation with VEGF-A165, a ligand-blocking antibody, and a CendR peptide led to NRP1 accumulation at cell-cell contacts in endothelial cell monolayers, increased cellular permeability in vitro and vascular leakage in vivo. Biochemical analyses, VEGF receptor-2 (VEGFR-2) silencing, and the use of a specific VEGFR blocker established that the effects induced by the CendR peptide and the antibody were independent of VEGFR-2. Moreover, leakage assays in mice expressing a mutant NRP1 lacking the cytoplasmic domain revealed that this domain was required for NRP1-induced vascular permeability in vivo. Hence, these data define a vascular permeability pathway mediated by NRP1 but independent of VEGFR-2 activation

    NEC FUTURE Preliminary Alternatives Report: Public Comment

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    The United States Department of Transportation's Federal Railroad Administration (FRA) is currently in the early stages of a planning process to define a 30-year passenger rail investment plan for the Northeast Corridor (NEC), between Boston and Washington, D.C. In the Spring of 2013, NEC FUTURE (the name of the planning process), released a Preliminary Alternatives Report, containing 15 possible alternatives for passenger rail infrastructure investment. This working paper contains a memo from the Regional Transportation Planning and High Speed Rail Research Group at the Massachusetts Institute of Technology (MIT) responding to the Preliminary Alternatives Report, as well as following up on the group's previous public comments to NEC FUTURE (ESD-WP-2012-27 NEC FUTURE Tier I Scoping Process: Public Comment). The memo focuses on the group's reactions in three areas: β€œgoals and objectives, and evaluation of the alternatives,” β€œplanning under uncertainty and flexible alternatives,” and β€œinstitutional assumptions.” These comments also build on the knowledge gained from report prepared for and funded by the Institute for Transportation Policy Studies (ITPS) in Tokyo, Japan, entitled Transportation in the Northeast Corridor of the U.S.: A Multimodal and Intermodal Conceptual Framework

    High Magnetic Shear Gain in a Liquid Sodium Stable Couette Flow Experiment; A Prelude to an alpha-Omega Dynamo

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    The Ξ©\Omega-phase of the liquid sodium Ξ±\alpha-Ξ©\Omega dynamo experiment at NMIMT in cooperation with LANL has successfully demonstrated the production of a high toroidal field, Bϕ≃8Γ—BrB_{\phi} \simeq 8\times B_r from the radial component of an applied poloidal magnetic field, BrB_r. This enhanced toroidal field is produced by rotational shear in stable Couette flow within liquid sodium at Rm≃120Rm \simeq 120. The small turbulence in stable Taylor-Couette flow is caused by Ekman flow where (Ξ΄v/v)2∼10βˆ’3 (\delta v/v)^2 \sim 10^{-3} . This high Ξ©\Omega-gain in low turbulence flow contrasts with a smaller Ξ©\Omega-gain in higher turbulence, Helmholtz-unstable shear flows. This result supports the ansatz that large scale astrophysical magnetic fields are created within semi-coherent large scale motions in which turbulence plays only a smaller diffusive role that enables magnetic flux linkage.Comment: 5 pages, 5 figures, submitted PRL revised version: add one author, minor typo'

    Caveolin-2 associates with intracellular chlamydial inclusions independently of caveolin-1

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    BACKGROUND: Lipid raft domains form in plasma membranes of eukaryotic cells by the tight packing of glycosphingolipids and cholesterol. Caveolae are invaginated structures that form in lipid raft domains when the protein caveolin-1 is expressed. The Chlamydiaceae are obligate intracellular bacterial pathogens that replicate entirely within inclusions that develop from the phagocytic vacuoles in which they enter. We recently found that host cell caveolin-1 is associated with the intracellular vacuoles and inclusions of some chlamydial strains and species, and that entry of those strains depends on intact lipid raft domains. Caveolin-2 is another member of the caveolin family of proteins that is present in caveolae, but of unknown function. METHODS: We utilized a caveolin-1 negative/caveolin-2 positive FRT cell line and laser confocal immunofluorescence techniques to visualize the colocalization of caveolin-2 with the chlamydial inclusions. RESULTS: We show here that in infected HeLa cells, caveolin-2, as well as caveolin-1, colocalizes with inclusions of C. pneumoniae (Cp), C. caviae (GPIC), and C. trachomatis serovars E, F and K. In addition, caveolin-2 also associates with C. trachomatis serovars A, B and C, although caveolin-1 did not colocalize with these organisms. Moreover, caveolin-2 appears to be specifically, or indirectly, associated with the pathogens at the inclusion membranes. Using caveolin-1 deficient FRT cells, we show that although caveolin-2 normally is not transported out of the Golgi in the absence of caveolin-1, it nevertheless colocalizes with chlamydial inclusions in these cells. However, our results also show that caveolin-2 did not colocalize with UV-irradiated Chlamydia in FRT cells, suggesting that in these caveolin-1 negative cells, pathogen viability and very likely pathogen gene expression are necessary for the acquisition of caveolin-2 from the Golgi. CONCLUSION: Caveolin-2 associates with the chlamydial inclusion independently of caveolin-1. The function of caveolin-2, either in the uninfected cell or in the chlamydial developmental cycle, remains to be elucidated. Nevertheless, this second caveolin protein can now be added to the small number of host proteins that are associated with the inclusions of this obligate intracellular pathogen

    Individualized chiropractic and integrative care for low back pain: the design of a randomized clinical trial using a mixed-methods approach

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    <p>Abstract</p> <p>Background</p> <p>Low back pain (LBP) is a prevalent and costly condition in the United States. Evidence suggests there is no one treatment which is best for all patients, but instead several viable treatment options. Additionally, multidisciplinary management of LBP may be more effective than monodisciplinary care. An integrative model that includes both complementary and alternative medicine (CAM) and conventional therapies, while also incorporating patient choice, has yet to be tested for chronic LBP.</p> <p>The primary aim of this study is to determine the relative clinical effectiveness of 1) monodisciplinary chiropractic care and 2) multidisciplinary integrative care in 200 adults with non-acute LBP, in both the short-term (after 12 weeks) and long-term (after 52 weeks). The primary outcome measure is patient-rated back pain. Secondary aims compare the treatment approaches in terms of frequency of symptoms, low back disability, fear avoidance, self-efficacy, general health status, improvement, satisfaction, work loss, medication use, lumbar dynamic motion, and torso muscle endurance. Patients' and providers' perceptions of treatment will be described using qualitative methods, and cost-effectiveness and cost utility will be assessed.</p> <p>Methods and Design</p> <p>This paper describes the design of a randomized clinical trial (RCT), with cost-effectiveness and qualitative studies conducted alongside the RCT. Two hundred participants ages 18 and older are being recruited and randomized to one of two 12-week treatment interventions. Patient-rated outcome measures are collected via self-report questionnaires at baseline, and at 4, 12, 26, and 52 weeks post-randomization. Objective outcome measures are assessed at baseline and 12 weeks by examiners blinded to treatment assignment. Health care cost data is collected by self-report questionnaires and treatment records during the intervention phase and by monthly phone interviews thereafter. Qualitative interviews, using a semi-structured format, are conducted with patients at the end of the 12-week treatment period and also with providers at the end of the trial.</p> <p>Discussion</p> <p>This mixed-methods randomized clinical trial assesses clinical effectiveness, cost-effectiveness, and patients' and providers' perceptions of care, in treating non-acute LBP through evidence-based individualized care delivered by monodisciplinary or multidisciplinary care teams.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00567333</p

    The Weaker Sex? The Propensity for Male-Biased Piglet Mortality

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    For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t35β€Š=β€Š2.51 Pβ€Š=β€Š0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively zβ€Š=β€Š2.06 Pβ€Š=β€Š0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and providing an over-supply of this more vulnerable sex in expectation of sex-biased mortality

    How robust are the natural history parameters used in chlamydia transmission dynamic models? A systematic review

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    Transmission dynamic models linked to economic analyses often form part of the decision making process when introducing new chlamydia screening interventions. Outputs from these transmission dynamic models can vary depending on the values of the parameters used to describe the infection. Therefore these values can have an important influence on policy and resource allocation. The risk of progression from infection to pelvic inflammatory disease has been extensively studied but the parameters which govern the transmission dynamics are frequently neglected. We conducted a systematic review of transmission dynamic models linked to economic analyses of chlamydia screening interventions to critically assess the source and variability of the proportion of infections that are asymptomatic, the duration of infection and the transmission probability. We identified nine relevant studies in Pubmed, Embase and the Cochrane database. We found that there is a wide variation in their natural history parameters, including an absolute difference in the proportion of asymptomatic infections of 25% in women and 75% in men, a six-fold difference in the duration of asymptomatic infection and a four-fold difference in the per act transmission probability. We consider that much of this variation can be explained by a lack of consensus in the literature. We found that a significant proportion of parameter values were referenced back to the early chlamydia literature, before the introduction of nucleic acid modes of diagnosis and the widespread testing of asymptomatic individuals. In conclusion, authors should use high quality contemporary evidence to inform their parameter values, clearly document their assumptions and make appropriate use of sensitivity analysis. This will help to make models more transparent and increase their utility to policy makers
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