2,022 research outputs found
Theory of magnetic spin and orbital Hall and Nernst effects in bulk ferromagnets
The magnetic spin Hall effect (MSHE) is an anomalous charge-to-spin
conversion phenomenon which occurs in ferromagnetic materials. In contrast to
the conventional spin Hall effect (SHE), being a time-reversal even effect, the
magnetic counterpart is time-reversal odd. In this work, we use ab initio
calculations to investigate the MSHE for the bulk ferromagnets Fe, Co, and Ni.
The magnitudes of the MSHE of Fe and Co are comparable to those of the SHE, but
the MSHE is strongly dependent on the electron lifetime and the MSHE and SHE
can moreover have opposite signs. For Ni the MSHE is smaller than the SHE, but
in general, the MSHE cannot be ignored for spin-orbit torques. Considering a
charge current we analyze how both the MSHE and SHE contribute to a total Hall
angle. We extend our analysis of the MSHE to its orbital counterpart, that is,
the magnetic orbital Hall effect (MOHE), for which we show that the MOHE is in
general smaller than the orbital Hall effect (OHE). We compute furthermore the
thermal analogs, i.e., the spin and orbital Nernst effects, and their magnetic
counterparts. Here our calculations show that the magnetic spin and orbital
Nernst effects of Ni are substantially larger than those of Fe and Co
Effectiveness of a Federal Healthy Start Program in Reducing Infant Mortality
Objective: Infant mortality is an important indicator of the health status of a community. In this analysis, we aimed to evaluate temporal changes in infant mortality rates (IMR) in the Central Hillsborough Healthy Start (CHHS) program service area in Tampa, Florida compared to rates in the rest of Hillsborough County and the state.
Method: We conducted a five-year (2010-2014) trends analysis using birth and infant death data extracted from the Florida Community Health Assessment Resource Tool Set (CHARTS). The number of infant deaths and live births were used to calculate and compare IMRs in the CHHS catchment area to those in the rest of Hillsborough County, and the state of Florida. Three-year centered moving averages were directly adjusted to account for differences in the racial/ethnic distribution of mothers across geographic areas.
Results: Between 2010 and 2014, the IMR decreased 42.8% in the CHHS service area (from 14.5 to 8.3 per 1,000 live births) compared to decreases of 10.1% and 7.7% in the rest of Hillsborough County and the state of Florida, respectively. Additionally, the infant mortality gap in the CHHS catchment area narrowed from 72% in 2010 to 14% in 2014 compared to the rest of the state, and was eliminated when compared to the rest of Hillsborough County.
Discussion: The absolute and relative decreases in IMR in the CHHS catchment area reflect the program’s effectiveness in decreasing disparity in infant mortality. The quality services provided by the CHHS program have had a significant positive impact on the families served
Enhancing the significance of gravitational wave bursts through signal classification
The quest to observe gravitational waves challenges our ability to
discriminate signals from detector noise. This issue is especially relevant for
transient gravitational waves searches with a robust eyes wide open approach,
the so called all- sky burst searches. Here we show how signal classification
methods inspired by broad astrophysical characteristics can be implemented in
all-sky burst searches preserving their generality. In our case study, we apply
a multivariate analyses based on artificial neural networks to classify waves
emitted in compact binary coalescences. We enhance by orders of magnitude the
significance of signals belonging to this broad astrophysical class against the
noise background. Alternatively, at a given level of mis-classification of
noise events, we can detect about 1/4 more of the total signal population. We
also show that a more general strategy of signal classification can actually be
performed, by testing the ability of artificial neural networks in
discriminating different signal classes. The possible impact on future
observations by the LIGO-Virgo network of detectors is discussed by analysing
recoloured noise from previous LIGO-Virgo data with coherent WaveBurst, one of
the flagship pipelines dedicated to all-sky searches for transient
gravitational waves
Regional Partnerships for Living Labs: the Case of Sicily and the MedLab Project
Abstract: This paper addresses the issue of how the Living Lab model can be integrated into regional development policy, through a “demand-pull” approach to innovation in which institutional innovation plays a key role in the form of bottom-up partnerships between a range of actors. The MedLab project, funded by the ERDF in the MED programme, addresses this issue with eight partners in seven Mediterranean regions. The paper first discusses the case of a concrete experience in building a regional Living Lab partnership in the Sicilian region and how the lessons learned shaped the MedLab approach and workplan. The first activities in MedLab are then presented as a more structured attempt at laying the ground for stable Living Lab governance mechanisms that will be tested in the project’s pilot projects. The ultimate aim is to permanently integrate the Living Lab approach as a transversal instrument of regional innovation policies in the Mediterranean basin, as a model for other regions in Europe
Three Dimensional Dynamic Analysis of Alborz Dam with Asphalt and Clay Cores
Alborz rockfill dam with a clay core is under construction in North of Iran, an area of heavy rainfall. Because of the difficulties in the construction of a clay core in a wet area, an alternative for the watertight element (asphalt core) was considered. During the design of Alborz dam, a dynamic response analysis of the asphalt core was performed using two-dimensional modeling based on the equivalent linear method. Considering the shortage of study on the seismic behavior of asphalt core dams and also the high level of risk of earthquakes in Iran, it was necessary that the dynamic behavior of this dam was studied using three-dimensional models. In this study, the dynamic response of Alborz dam for both variants of clay and asphalt cores has been investigated and three-dimensional dynamic (non-linear) analyses have been carried out using the explicit finite-difference program, FLAC3-D, under various hazard levels of earthquakes (DBL and MCL). The results obtained included: time histories of the response acceleration, displacement, shear stress and shear strains are presented in this paper. The dynamic response of the dam with a clay core and asphalt core are compared with each other
Investigation of Dynamic Behavior of Asphalt Core Dams
In this research, dynamic behavior of a rockfill dam with asphalt-concrete core has been studied utilizing numerical models and centrifuge model tests with material parameters determined by laboratory tests including static and cyclic triaxial tests and also wave velocity measurements. The case study selected is the Meyjaran asphalt core dam, recently constructed in Northern Iran, with 60 m height and 180 m crest length. The seismic response analyses have been performed using a non-linear three dimensional finite difference software under various hazard levels of earthquake loadings. Their results showed that the induced shear strains in the asphalt core are less than 1% during an earthquake with amax=0.25g and the asphalt core remains watertight. Also, the small scale physical models of the asphalt core dam have been tested on centrifuge, under impact loading and response accelerations and induced deformations were recorded by instruments installed within and on the models. The recorded data and observations of the centrifuge model tested at 80g acceleration showed that the induced deformations in the asphalt core under an impact load with a large acceleration of 7.6 m/s2 were very small. Comparing the results of centrifuge tests with the results of numerical dynamic analyses of a prototype dam indicated that the numerical results corresponded well with the data recorded during centrifuge tests
Water management for sustainable irrigated agriculture in the Zayandeh Rud Basin, Esfahan Province, Iran
Irrigation systemsCropping systemsIrrigated farmingRiver basinsTopographyGeomorphologyClimateHydrologyWater qualityGroundwaterSoil salinitySustainable agricultureIranEsfahan ProvinceZayandeh Rud BasinChadegan Reservoir
Characterization of RanBPM Molecular Determinants that Control its Subcellular Localization
RanBPM/RanBP9 is a ubiquitous, nucleocytoplasmic protein that is part of an evolutionary conserved E3 ubiquitin ligase complex whose function and targets in mammals are still unknown. RanBPM itself has been implicated in various cellular processes that involve both nuclear and cytoplasmic functions. However, to date, little is known about how RanBPM subcellular localization is regulated. We have conducted a systematic analysis of RanBPM regions that control its subcellular localization using RanBPM shRNA cells to examine ectopic RanBPM mutant subcellular localization without interference from the endogenously expressed protein. We show that several domains and motifs regulate RanBPM nuclear and cytoplasmic localization. In particular, RanBPM comprises two motifs that can confer nuclear localization, one proline/glutamine-rich motif in the extreme N-terminus which has a dominant effect on RanBPM localization, and a second motif in the C-terminus which minimally contributes to RanBPM nuclear targeting. We also identified a nuclear export signal (NES) which mutation prevented RanBPM accumulation in the cytoplasm. Likewise, deletion of the central RanBPM conserved domains (SPRY and LisH/CTLH) resulted in the relocalization of RanBPM to the nucleus, suggesting that RanBPM cytoplasmic localization is also conferred by protein-protein interactions that promote its cytoplasmic retention. Indeed we found that in the cytoplasm, RanBPM partially colocalizes with microtubules and associates with α-tubulin. Finally, in the nucleus, a significant fraction of RanBPM is associated with chromatin. Altogether, these analyses reveal that RanBPM subcellular localization results from the combined effects of several elements that either confer direct transport through the nucleocytoplasmic transport machinery or regulate it indirectly, likely through interactions with other proteins and by intramolecular folding
Prospects for intermediate mass black hole binary searches with advanced gravitational-wave detectors
We estimated the sensitivity of the upcoming advanced, ground-based
gravitational-wave observatories (the upgraded LIGO and Virgo and the KAGRA
interferometers) to coalescing intermediate mass black hole binaries (IMBHB).
We added waveforms modeling the gravitational radiation emitted by IMBHBs to
detectors' simulated data and searched for the injected signals with the
coherent WaveBurst algorithm. The tested binary's parameter space covers
non-spinning IMBHBs with source-frame total masses between 50 and 1050
and mass ratios between and 1. We found that
advanced detectors could be sensitive to these systems up to a range of a few
Gpc. A theoretical model was adopted to estimate the expected observation
rates, yielding up to a few tens of events per year. Thus, our results indicate
that advanced detectors will have a reasonable chance to collect the first
direct evidence for intermediate mass black holes and open a new, intriguing
channel for probing the Universe over cosmological scales.Comment: 9 pages, 4 figures, corrected the name of one author (previously
misspelled
Noninvasive PET Imaging and Tracking of Engineered Human Muscle Precursor Cells for Skeletal Muscle Tissue Engineering
Transplantation of human muscle precursor cells (hMPCs) is envisioned for the treatment of various muscle diseases. However, a feasible noninvasive tool to monitor cell survival, migration, and integration into the host tissue is still missing.
METHODS: In this study, we designed an adenoviral delivery system to genetically modify hMPCs to express a signaling-deficient form of human dopamine D2 receptor (hD2R). The gene expression levels of the receptor were evaluated by reverse transcriptase polymerase chain reaction, and infection efficiency was evaluated by fluorescent microscopy. The viability, proliferation, and differentiation capacity of the transduced cells, as well as their myogenic phenotype, were determined by flow cytometry analysis and fluorescent microscopy. (18)F-fallypride and (18)F-fluoromisonidazole, two well-established PET radioligands, were assessed for their potential to image engineered hMPCs in a mouse model and their uptakes were evaluated at different time points after cell inoculation in vivo. Biodistribution studies, autoradiography, and PET experiments were performed to determine the extent of signal specificity. To address feasibility for tracking hMPCs in an in vivo model, the safety of the adenoviral gene delivery was evaluated. Finally, the harvested tissues were histologically examined to determine whether survival of the transplanted cells was sustained at different time points.
RESULTS: Adenoviral gene delivery was shown to be safe, with no detrimental effects on the primary human cells. The viability, proliferation, and differentiation capacity of the transduced cells were confirmed, and flow cytometry analysis and fluorescent microscopy showed that their myogenic phenotype was sustained. (18)F-fallypride and (18)F-fluoromisonidazole were successfully synthesized. Specific binding of (18)F-fallypride to hD2R hMPCs was demonstrated in vitro and in vivo. Furthermore, the (18)F-fluoromisonidazole signal was high at the early stages. Finally, sustained survival of the transplanted cells at different time points was confirmed histologically, with formation of muscle tissue at the site of injection.
CONCLUSION: Our proposed use of a signaling-deficient hD2R as a potent reporter for in vivo hMPC PET tracking by (18)F-fallypride is a significant step toward potential noninvasive tracking of hD2R hMPCs and bioengineered muscle tissues in the clinic
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