8,299 research outputs found
Quenched Charmed Meson Spectra using Tadpole Improved Quark Action on Anisotropic Lattices
Charmed meson charmonium spectra are studied with improved quark actions on
anisotropic lattices. We measured the pseudo-scalar and vector meson dispersion
relations for 4 lowest lattice momentum modes with quark mass values ranging
from the strange quark to charm quark with 3 different values of gauge coupling
and 4 different values of bare speed of light . With the bare
speed of light parameter tuned in a mass-dependent way, we study the mass
spectra of , , ,
, and mesons.
The results extrapolated to the continuum limit are compared with the
experiment and qualitative agreement is found.Comment: 8 pages, 2 figures, latex fil
Spatiotemporal complexity of a ratio-dependent predator-prey system
In this paper, we investigate the emergence of a ratio-dependent
predator-prey system with Michaelis-Menten-type functional response and
reaction-diffusion. We derive the conditions for Hopf, Turing and Wave
bifurcation on a spatial domain. Furthermore, we present a theoretical analysis
of evolutionary processes that involves organisms distribution and their
interaction of spatially distributed population with local diffusion. The
results of numerical simulations reveal that the typical dynamics of population
density variation is the formation of isolated groups, i.e., stripelike or
spotted or coexistence of both. Our study shows that the spatially extended
model has not only more complex dynamic patterns in the space, but also chaos
and spiral waves. It may help us better understand the dynamics of an aquatic
community in a real marine environment.Comment: 6pages, revtex
Quantum Thermodynamic Cycles and quantum heat engines
In order to describe quantum heat engines, here we systematically study
isothermal and isochoric processes for quantum thermodynamic cycles. Based on
these results the quantum versions of both the Carnot heat engine and the Otto
heat engine are defined without ambiguities. We also study the properties of
quantum Carnot and Otto heat engines in comparison with their classical
counterparts. Relations and mappings between these two quantum heat engines are
also investigated by considering their respective quantum thermodynamic
processes. In addition, we discuss the role of Maxwell's demon in quantum
thermodynamic cycles. We find that there is no violation of the second law,
even in the existence of such a demon, when the demon is included correctly as
part of the working substance of the heat engine.Comment: 17 pages, 9 figures, 4 table
Access to and Use of Technology for Health: Comparisons Between Appalachian Kentuckians and the General U.S. Population
Introduction: Technology may increase the availability of health information and enable health promoting behaviors. However, lack of access to and use of technology may also exacerbate disparities, particularly in rural communities with limited Internet access.
Purpose: The purpose of this study was to compare Internet access, device ownership, and use of technology for health between Appalachian Kentuckians and the general U.S. population. Methods: Findings from the 2017 Assessing the Health Status of Kentucky (ASK) survey were compared to national estimates from the Health Information National Trends Survey (HINTS) 5, Cycle 1 (2017), with a particular focus on degree of rurality. ASK and HINTS respondent sociodemographics, Internet access, and use of technology for health were assessed using weighted percentages; chi-square P-values were calculated based on weighted counts. Results: Over 80% of both populations reported accessing the Internet. However, Appalachian Kentuckians across all geographic strata were significantly less likely to access the Internet through broadband, cellular networks, and Wi-Fi. The U.S. population reported greater electronic device ownership rates. Appalachian Kentuckians were significantly more likely to search for cancer information online compared to national estimates. The majority of both populations reported not having health apps on their smartphones or tablets. Appalachian Kentuckians reported significantly lower rates of using electronic media to exchange information with health professionals. Implications: Ensuring high-speed Internet access among Appalachian Kentuckians could help this population leverage available technology to overcome barriers to care and reduce health disparities – for example, by enabling the use of health-related apps or electronic means to remotely communicate with providers. Such technologies have the potential to improve the health of medically underserved populations and deserve further attention
Recommended from our members
Do MNEs from developed and emerging economies differ in their location choice of FDI? A 36-year review
This study examines the extent to which MNEs from developed (DMNEs) and emerging (EMNEs) economies differ in Location behaviour. Studies on MNE location choices have failed to capture the changing FDI landscape and leave the inconsistent findings unexplained. We address this gap by systematically reviewing the extant literature on location choices of DMNEs and EMNEs over the past 36 years – from the introduction of the OLI model to 2016. Key themes emerging from the review reflect a comprehensive picture, capturing the impact of multiple factors affecting location choices of DMNEs and EMNEs. Future research is challenged by: a. adopting an integrated approach examining three levels – individual (managerial), firm (ownership structure, type of FDI, internationalisation stages, and the different nature of ownership advantage), and context of location decisions (home, host, sub-national, regional, supranational, and networking); b. refining or developing theories to capture the dynamic picture of MNE internationalisation
The Zwicky Transient Facility: Surveys and Scheduler
We present a novel algorithm for scheduling the observations of time-domain
imaging surveys. Our Integer Linear Programming approach optimizes an observing
plan for an entire night by assigning targets to temporal blocks, enabling
strict control of the number of exposures obtained per field and minimizing
filter changes. A subsequent optimization step minimizes slew times between
each observation. Our optimization metric self-consistently weights
contributions from time-varying airmass, seeing, and sky brightness to maximize
the transient discovery rate. We describe the implementation of this algorithm
on the surveys of the Zwicky Transient Facility and present its on-sky
performance.Comment: Published in PASP Focus Issue on the Zwicky Transient Facility
(https://dx.doi.org/10.1088/1538-3873/ab0c2a). 13 Pages, 11 Figure
Agephagy – Adapting Autophagy for Health During Aging
Autophagy is a major cellular recycling process that delivers cellular material and entire
organelles to lysosomes for degradation, in a selective or non-selective manner. This
process is essential for the maintenance of cellular energy levels, components, and
metabolites, as well as the elimination of cellular molecular damage, thereby playing
an important role in numerous cellular activities. An important function of autophagy
is to enable survival under starvation conditions and other stresses. The majority of
factors implicated in aging are modifiable through the process of autophagy, including
the accumulation of oxidative damage and loss of proteostasis, genomic instability and
epigenetic alteration. These primary causes of damage could lead to mitochondrial
dysfunction, deregulation of nutrient sensing pathways and cellular senescence, finally
causing a variety of aging phenotypes. Remarkably, advances in the biology of
aging have revealed that aging is a malleable process: a mild decrease in signaling
through nutrient-sensing pathways can improve health and extend lifespan in all model
organisms tested. Consequently, autophagy is implicated in both aging and age-related
disease. Enhancement of the autophagy process is a common characteristic of all
principal, evolutionary conserved anti-aging interventions, including dietary restriction,
as well as inhibition of target of rapamycin (TOR) and insulin/IGF-1 signaling (IIS). As an
emerging and critical process in aging, this review will highlight how autophagy can be
modulated for health improvement
Heterotopic and Orthotopic Tracheal Transplantation in Mice used as Models to Study the Development of Obliterative Airway Disease
Obliterative airway disease (OAD) is the major complication after lung transplantations that limits long term survival (1-7)
Entanglement in spin-one Heisenberg chains
By using the concept of negativity, we study entanglement in spin-one
Heisenberg chains. Both the bilinear chain and the bilinear-biquadratic chain
are considered. Due to the SU(2) symmetry, the negativity can be determined by
two correlators, which greatly facilitate the study of entanglement properties.
Analytical results of negativity are obtained in the bilinear model up to four
spins and the two-spin bilinear-biquadratic model, and numerical results of
negativity are presented. We determine the threshold temperature before which
the thermal state is doomed to be entangled.Comment: 7 pages and 4 figure
- …