829 research outputs found
International Migration with Heterogeneous Agents: Theory and Evidence for Germany, 1967-2009
Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships of German migration stocks and flows since 1967. We find that (i) panel-unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis of cointegration cannot be rejected for the stock model.International migration, temporary migration, panel cointegration
Evaluating the Intra-Rater and Inter-Rater Reliability of Fixed Tension Scale Instrumentation for Determining Isometric Neck Strength
International Journal of Exercise Science 14(3): 563-577, 2021. PURPOSE: The purpose of this study was to evaluate the reliability of a fixed tension scale instrumentation, comparing the intra-rater and inter-rater reliability between seating and standing measurement techniques. Instrumentation developed from this study will be utilized to assess isometric neck strength in future studies comparing neck strengthening protocols. METHODS: Isometric neck strength for eight movements (cervical/capital flexion, cervical/capital extension, left/right lateral flexion, left/right cervical rotation) as well as anthropometric measurements were evaluated for thirty-one participants through the use of a novel neck strength assessment protocol. RESULTS: The fixed tension scale instrumentation and methods used in this study demonstrated good to excellent intra-rater reliability (ICC range from 0.78 to 0.97) as well as moderate to excellent inter-rater reliability (ICC range from 0.73 to 0.91) for both measurement techniques. PRACTICAL APPLICATIONS: This study will provide foundational knowledge for the reliable assessment of neck strength. Additionally, the findings will provide a cost-effective, portable, and reliable instrument for measuring isometric neck strength. CONCLUSIONS: Seated and standing measurement techniques demonstrated similar intra and inter-rater reliability. Inter-rater reliability tended to be lower with motions (capital flexion and extension) that required the participants to face directly towards or away from the instrumentation. This could be due to participant positioning or unfamiliarity with those specific movements. The assessment protocol utilized in this study demonstrated comparable inter-rater reliability to another cost-effective method for evaluating isometric neck strength
Commercial Aircraft-Cabin Egress: The Current State of Simulation Model Development and the Need for Future Research
There has been increasing interest in developing simulation models capable of analyzing commer cial aircraft-cabin egress under both non-life- threatening and life-threatening scenarios. At issue is the ability to accurately simulate human behavior within non-toxic environments, as well as the debilitating effects that toxic environments (e.g., fire and smoke) have on human-decision making. A set of criteria has been identified by the Federal Aviation Administration for developing simulation models capable of analyzing commer cial aircraft-cabin egress. These criteria are used to (a) compare the capabilities and limitations of four aircraft-evacuation models in existence to day, (b) identify the issues that need to be ad dressed when developing these types of models, and (c) propose a new paradigm for developing aircraft-cabin egress models.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
T-bet controls intestinal mucosa immune responses via repression of type 2 innate lymphoid cell function
Innate lymphoid cells (ILCs) play an important role in regulating immune responses at mucosal surfaces. The transcription factor T-bet is crucial for the function of ILC1s and NCR+ ILC3s and constitutive deletion of T-bet prevents the development of these subsets. Lack of T-bet in the absence of an adaptive immune system causes microbiota-dependent colitis to occur due to aberrant ILC3 responses. Thus, T-bet expression in the innate immune system has been considered to dampen pathogenic immune responses. Here, we show that T-bet plays an unexpected role in negatively regulating innate type 2 responses, in the context of an otherwise intact immune system. Selective loss of T-bet in ILCs leads to the expansion and increased activity of ILC2s, which has a functionally important impact on mucosal immunity, including enhanced protection from Trichinella spiralis infection and inflammatory colitis. Mechanistically, we show that T-bet controls the intestinal ILC pool through regulation of IL-7 receptor signalling. These data demonstrate that T-bet expression in ILCs acts as the key transcriptional checkpoint in regulating pathogenic vs. protective mucosal immune responses, which has significant implications for the understanding of the pathogenesis of inflammatory bowel diseases and intestinal infections
Anomalous Roughening in Experiments of Interfaces in Hele-Shaw Flows with Strong Quenched Disorder
We report experimental evidences of anomalous kinetic roughening in the
stable displacement of an oil-air interface in a Hele-Shaw cell with strong
quenched disorder. The disorder consists on a random modulation of the gap
spacing transverse to the growth direction (tracks). We have performed
experiments varying average interface velocity and gap spacing, and measured
the scaling exponents. We have obtained beta=0.50, beta*=0.25, alpha=1.0,
alpha_l=0.5, and z=2. When there is no fluid injection, the interface is driven
solely by capillary forces, and a higher value of beta around beta=0.65 is
measured. The presence of multiscaling and the particular morphology of the
interfaces, characterized by high slopes that follow a L\'evy distribution,
confirms the existence of anomalous scaling. From a detailed study of the
motion of the oil--air interface we show that the anomaly is a consequence of
different local velocities over tracks plus the coupling in the motion between
neighboring tracks. The anomaly disappears at high interface velocities, weak
capillary forces, or when the disorder is not sufficiently persistent in the
growth direction. We have also observed the absence of scaling when the
disorder is very strong or when a regular modulation of the gap spacing is
introduced.Comment: 14 pages, 17 figure
MYCN and HDAC2 cooperate to repress miR-183 signaling in neuroblastoma
MYCN is a master regulator controlling many processes necessary for tumor cell survival. Here, we unravel a microRNA network that causes tumor suppressive effects in MYCN-amplified neuroblastoma cells. In profiling studies, histone deacetylase (HDAC) inhibitor treatment most strongly induced miR-183. Enforced miR-183 expression triggered apoptosis, and inhibited anchorage-independent colony formation in vitro and xenograft growth in mice. Furthermore, the mechanism of miR-183 induction was found to contribute to the cell death phenotype induced by HDAC inhibitors. Experiments to identify the HDAC(s) involved in miR-183 transcriptional regulation showed that HDAC2 depletion induced miR-183. HDAC2 overexpression reduced miR-183 levels and counteracted the induction caused by HDAC2 depletion or HDAC inhibitor treatment. MYCN was found to recruit HDAC2 in the same complexes to the miR-183 promoter, and HDAC2 depletion enhanced promoter-associated histone H4 pan-acetylation, suggesting epigenetic changes preceded transcriptional activation. These data reveal miR-183 tumor suppressive properties in neuroblastoma that are jointly repressed by MYCN and HDAC2, and suggest a novel way to bypass MYCN function
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Design and analysis of a 20 MW propulsion power train
The electric ship research program at the University of Texas at Austin focuses on the development of power system technology for future electric ships. The main goal of the on-going research activity is to identify critical, high pay-off technology development needed to enable major improvement, in size and functionality, of navy ships power systems. Initial efforts were directed towards the establishment of a baseline power train which highlights various constraints and provides a basis for later optimization efforts. A 20 MW power train system was chosen for such a baseline, and all components, from fuel to propulsion motor, were considered and their impact on the whole power system assessed. The baseline design consists of a 25 MVA/3600 rpm radial flux permanent magnet generator, a 22 MVA PWM converter, and a 20 MW/150 rpm radial flux permanent magnet motor, along with the amount of fuel sized for an assumed mission profile, and the widely used LM2500 gas turbine. The analysis shows that fuel is by far the dominant component contributing to weight and volume and, consequently, overall efficiency of power train components is the most relevant parameter to reduce weight and volume. The 3600 rpm generator is the smallest component. The 150 rpm motor is the heaviest component, other than fuel, weighing close to 100 tonnes.Center for Electromechanic
Alteration in the plasma concentration of a DAAO inhibitor, 3-methylpyrazole-5-carboxylic acid, in the ketamine-treated rats and the influence on the pharmacokinetics of plasma d-tryptophan
A determination method for 3-methylpyrazole-5-carboxylic acid (MPC), an inhibitor of d-amino acid oxidase (DAAO), in rat plasma was developed by using high-performance liquid chromatography-mass spectrometry (LC-MS). The structural isomer of MPC, 3-methylpyrazole-4-carboxylic acid, was used as an internal standard, and the intra- and inter-day accuracies and precisions were satisfactory for the determination of plasma MPC
The Deuteron Spin-dependent Structure Function g1d and its First Moment
We present a measurement of the deuteron spin-dependent structure function
g1d based on the data collected by the COMPASS experiment at CERN during the
years 2002-2004. The data provide an accurate evaluation for Gamma_1^d, the
first moment of g1d(x), and for the matrix element of the singlet axial
current, a0. The results of QCD fits in the next to leading order (NLO) on all
g1 deep inelastic scattering data are also presented. They provide two
solutions with the gluon spin distribution function Delta G positive or
negative, which describe the data equally well. In both cases, at Q^2 = 3
(GeV/c)^2 the first moment of Delta G is found to be of the order of 0.2 - 0.3
in absolute value.Comment: fits redone using MRST2004 instead of MRSV1998 for G(x), correlation
matrix adde
A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target
New high precision measurements of the Collins and Sivers asymmetries of
charged hadrons produced in deep-inelastic scattering of muons on a
transversely polarised 6LiD target are presented. The data were taken in 2003
and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at
160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible
with zero, within the present statistical errors, which are more than a factor
of 2 smaller than those of the published COMPASS results from the 2002 data.
The final results from the 2002, 2003 and 2004 runs are compared with naive
expectations and with existing model calculations.Comment: 40 pages, 28 figure
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