1,802 research outputs found
Level Density of a Bose Gas and Extreme Value Statistics
We establish a connection between the level density of a gas of
non-interacting bosons and the theory of extreme value statistics. Depending on
the exponent that characterizes the growth of the underlying single-particle
spectrum, we show that at a given excitation energy the limiting distribution
function for the number of excited particles follows the three universal
distribution laws of extreme value statistics, namely Gumbel, Weibull and
Fr\'echet. Implications of this result, as well as general properties of the
level density at different energies, are discussed.Comment: 4 pages, no figure
Resistivity due to a Domain Wall in Ferromagnetic Metal
The resistivity due to a domain wall in ferromagnetic metallic wire is
calculated based on the linear response theory. The interaction between
conduction electrons and the wall is expressed in terms of a classical gauge
field which is introduced by the local gauge transformation in the electron
spin space. It is shown that the wall contributes to the decoherence of
electrons and that this quantum correction can dominate over the Boltzmann
resisitivity, leading to a decrease of resisitivity by nucleation of a wall.
The conductance fluctuation due to the motion of the wall is also investigated.
The results are compared with recent experiments.Comment: 9 pages, 3 figure
PedHunter 2.0 and its usage to characterize the founder structure of the Old Order Amish of Lancaster County
<p>Abstract</p> <p>Background</p> <p>Because they are a closed founder population, the Old Order Amish (OOA) of Lancaster County have been the subject of many medical genetics studies. We constructed four versions of Anabaptist Genealogy Database (AGDB) using three sources of genealogies and multiple updates. In addition, we developed PedHunter, a suite of query software that can solve pedigree-related problems automatically and systematically.</p> <p>Methods</p> <p>We report on how we have used new features in PedHunter to quantify the number and expected genetic contribution of founders to the OOA. The queries and utility of PedHunter programs are illustrated by examples using AGDB in this paper. For example, we calculated the number of founders expected to be contributing genetic material to the present-day living OOA and estimated the mean relative founder representation for each founder. New features in PedHunter also include pedigree trimming and pedigree renumbering, which should prove useful for studying large pedigrees.</p> <p>Results</p> <p>With PedHunter version 2.0 querying AGDB version 4.0, we identified 34,160 presumed living OOA individuals and connected them into a 14-generation pedigree descending from 554 founders (332 females and 222 males) after trimming. From the analysis of cumulative mean relative founder representation, 128 founders (78 females and 50 males) accounted for over 95% of the mean relative founder contribution among living OOA descendants.</p> <p>Discussion/Conclusions</p> <p>The OOA are a closed founder population in which a modest number of founders account for the genetic variation present in the current OOA population. Improvements to the PedHunter software will be useful in future studies of both the OOA and other populations with large and computerized genealogies.</p
Monitoring local well-being in environmental interventions: a consideration of practical trade-offs
Within the field of environmental management and conservation, the concept of well-being is starting to gain traction in monitoring the socio-economic and cultural impact of interventions on local people. Here we consider the practical trade-offs policy makers and practitioners must navigate when utilizing the concept of well-being in environmental interventions. We first review current concepts of well-being before considering the need to balance the complexity and practical applicability of the definition used and to consider both positive and negative components of well-being. A key determinant of how well-being is operationalized is the identity of the organization wishing to monitor it. We describe the trade-offs around the external and internal validity of different approaches to measuring well-being and the relative contributions of qualitative and quantitative information to understanding well-being. We explore how these trade-offs may be decided as a result of a power struggle between stakeholders. Well-being is a complex, multi-dimensional, dynamic concept that cannot be easily defined and measured. Local perspectives are often missed during the project design process as a result of the more powerful voices of national governments and international NGOs, so for equity and local relevance it is important to ensure these perspectives are represented at a high level in project design and implementation
High-throughput sequencing of the DBA/2J mouse genome
The DBA/2J mouse is not only the oldest inbred strain, but also one of the most widely used strains. DBA/2J exhibits many unique anatomical, physiological, and behavior traits. In addition, DBA/2J is one parent of the large BXD family of recombinant inbred strains [1]. The genome of the other parent of this BXD family— C57BL/6J—has been sequenced and serves as the mouse reference genome [2]. We sequenced the genome of DBA/2J using SOLiD and Illumina high throughput short read protocols to generate a comprehensive set of ~5 million sequence variants segregating in the BXD family that ultimately cause developmental, anatomical, functional and behavioral differences among these 80+ strains
Aldehyde Dehydrogenase (ALDH) Activity Does Not Select for Cells with Enhanced Aggressive Properties in Malignant Melanoma
Malignant melanoma is an exceptionally aggressive, drug-resistant and heterogeneous cancer. Recently it has been shown that melanoma cells with high clonogenic and tumourigenic abilities are common, but markers distinguishing such cells from cells lacking these abilities have not been identified. There is therefore no definite evidence that an exclusive cell subpopulation, i.e. cancer stem cells (CSC), exists in malignant melanoma. Rather, it is suggested that multiple cell populations are implicated in initiation and progression of the disease, making it of importance to identify subpopulations with elevated aggressive properties.. Furthermore, both subpopulations showed similar sensitivity to the anti-melanoma drugs, dacarbazine and lexatumumab.These findings suggest that ALDH does not distinguish tumour-initiating and/or therapy-resistant cells, implying that the ALDH phenotype is not associated with more-aggressive subpopulations in malignant melanoma, and arguing against ALDH as a “universal” marker. Besides, it was shown that the ability to reestablish tumour heterogeneity is not necessarily linked to the more aggressive phenotype
Modulation of SOCS protein expression influences the interferon responsiveness of human melanoma cells
<p>Abstract</p> <p>Background</p> <p>Endogenously produced interferons can regulate the growth of melanoma cells and are administered exogenously as therapeutic agents to patients with advanced cancer. We investigated the role of negative regulators of interferon signaling known as suppressors of cytokine signaling (SOCS) in mediating interferon-resistance in human melanoma cells.</p> <p>Methods</p> <p>Basal and interferon-alpha (IFN-α) or interferon-gamma (IFN-γ)-induced expression of SOCS1 and SOCS3 proteins was evaluated by immunoblot analysis in a panel of n = 10 metastatic human melanoma cell lines, in human embryonic melanocytes (HEM), and radial or vertical growth phase melanoma cells. Over-expression of SOCS1 and SOCS3 proteins in melanoma cells was achieved using the PINCO retroviral vector, while siRNA were used to inhibit SOCS1 and SOCS3 expression. Tyr<sup>701</sup>-phosphorylated STAT1 (P-STAT1) was measured by intracellular flow cytometry and IFN-stimulated gene expression was measured by Real Time PCR.</p> <p>Results</p> <p>SOCS1 and SOCS3 proteins were expressed at basal levels in melanocytes and in all melanoma cell lines examined. Expression of the SOCS1 and SOCS3 proteins was also enhanced following stimulation of a subset of cell lines with IFN-α or IFN-γ. Over-expression of SOCS proteins in melanoma cell lines led to significant inhibition of Tyr<sup>701</sup>-phosphorylated STAT1 (P-STAT1) and gene expression following stimulation with IFN-α (IFIT2, OAS-1, ISG-15) or IFN-γ (IRF1). Conversely, siRNA inhibition of SOCS1 and SOCS3 expression in melanoma cells enhanced their responsiveness to interferon stimulation.</p> <p>Conclusions</p> <p>These data demonstrate that SOCS proteins are expressed in human melanoma cell lines and their modulation can influence the responsiveness of melanoma cells to IFN-α and IFN-γ.</p
The novel photon detectors based on MPGD technologies for the upgrade of COMPASS RICH-1
The RICH-1 Detector of the COMPASS experiment at CERN SPS has undergone an
important upgrade in 2016. Four new photon detectors, based on MPGD technology
and covering a total active area larger than 1.2~ have replaced the
previously used MWPC-based photon detectors. The new detector architecture,
resulting from a dedicated, eight years long, R\&D program, consists in a
hybrid MPGD combination of two THGEMs and a Micromegas stage; the first THGEM,
coated with a CsI layer, acts as a reflective photocathode. The signals are
extracted from the anode pads by capacitive coupling and read-out by analog
front-end electronics based on the APV25 chip. The new COMPASS RICH-1 photon
detectors are described in detail: the detector design, the engineering
aspects, the mass production, and the quality assessment are discussed. The
assembly of the MPGD components and the installation of the new detectors are
illustrated together with the main aspects of the commissioning. Preliminary
indication of performance results are also presented.Comment: 5th International Conference on Micro-Pattern Gas Detectors
(MPGD2017), speaker: F.Tessarotto (INFN -Trieste
Impact of Sequencing Targeted Therapies With High-dose Interleukin-2 Immunotherapy: An Analysis of Outcome and Survival of Patients With Metastatic Renal Cell Carcinoma From an On-going Observational IL-2 Clinical Trial: PROCLAIM
BACKGROUND: This analysis describes the outcome for patients who received targeted therapy (TT) prior to or following high-dose interleukin-2 (HD IL-2).
PATIENTS AND METHODS: Patients with renal cell carcinoma (n = 352) receiving HD IL-2 were enrolled in Proleukin
RESULTS: Overall, there were 4% complete response (CR), 13% partial response (PR), 39% stable disease (SD), and 43% progressive disease (PD) with HD IL-2. The median overall survival (mOS) was not reached in patients with CR, PR, or SD, and was 15.5 months in patients with PD (median follow-up, 21 months). Sixty-one patients had prior TT before HD IL-2 with an overall response rate (ORR) to HD IL-2 of 19% (1 CR, 9 PR) and an mOS of 22.1 months. One hundred forty-nine patients received TT only after HD IL-2 with an mOS of 35.5 months. One hundred forty-two patients had no TT before or after HD IL-2, and mOS was not reached. The mOS was 8.5 months in PD patients who received HD IL-2 without follow-on TT and 29.7 months in PD patients who received follow-on TT after HD IL-2.
CONCLUSIONS: HD IL-2 as sole front-line therapy, in the absence of added TT, shows extended clinical benefit (CR, PR, and SD). Patients with PD after HD IL-2 appear to benefit from follow-on TT. Patients who progressed on TT and received follow-on HD IL-2 experienced major clinical benefit. HD IL-2 therapy should be considered in eligible patients
Search for pair production of squarks or gluinos decaying via sleptons or weak bosons in final states with two same-sign or three leptons with the ATLAS detector
A search for pair production of squarks or gluinos decaying via sleptons or weak bosons is reported. The search targets a final state with exactly two leptons with same-sign electric charge or at least three leptons without any charge requirement. The analysed data set corresponds to an integrated luminosity of 139 fb−1 of proton-proton collisions collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Multiple signal regions are defined, targeting several SUSY simplified models yielding the desired final states. A single control region is used to constrain the normalisation of the WZ + jets background. No significant excess of events over the Standard Model expectation is observed. The results are interpreted in the context of several supersymmetric models featuring R-parity conservation or R-parity violation, yielding exclusion limits surpassing those from previous searches. In models considering gluino (squark) pair production, gluino (squark) masses up to 2.2 (1.7) TeV are excluded at 95% confidence level
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