300 research outputs found
Perspectives on Transitioning Uninsured Persons from an Emergency Department to Federally Qualified Health Centers in East Baltimore
Many people in the United States rely on the emergency department (ED) for their usual source of primary care. Linking these ED users to a source of longitudinal primary care could provide significant health benefits. To assess an intervention attempting to connect ED users to federally qualified health cents (FQHCs), we conducted semi-structured, in-depth interviews with volunteers, health facility providers, and a patient and a focus group with program volunteers. All sessions were digitally recorded, transcribed and analyzed to develop emergent themes highlighting the barriers and facilitating factors that affect the process of connecting patients to primary care. Themes included that 1) the ED is the preferred source of primary care over FQHCs, 2) there are limited links between EDs and FQHCs and 3) the evaluated intervention acts through and depends on patientsâ prioritization of health and access to resources. Our findings suggest that, in addition to addressing individual needs, social services programs are well positioned to help increase communication between providers at FQHCs and EDs about both the services available to patients and patientsâ medical care histories
Tunable electron-electron interactions in LaAlO3/SrTiO3 nanostructures
The interface between the two complex oxides LaAlO3 and SrTiO3 has remarkable
properties that can be locally reconfigured between conducting and insulating
states using a conductive atomic force microscope. Prior investigations of
sketched quantum dot devices revealed a phase in which electrons form pairs,
implying a strongly attractive electron-electron interaction. Here, we show
that these devices with strong electron-electron interactions can exhibit a
gate-tunable transition from a pair-tunneling regime to a single-electron
(Andreev bound state) tunneling regime where the interactions become repulsive.
The electron-electron interaction sign change is associated with a Lifshitz
transition where the dxz and dyz bands start to become occupied. This
electronically tunable electron-electron interaction, combined with the
nanoscale reconfigurability of this system, provides an interesting starting
point towards solid-state quantum simulation.Comment: 25 pages, 7 figure
Quantum computing with antiferromagnetic spin clusters
We show that a wide range of spin clusters with antiferromagnetic
intracluster exchange interaction allows one to define a qubit. For these spin
cluster qubits, initialization, quantum gate operation, and readout are
possible using the same techniques as for single spins. Quantum gate operation
for the spin cluster qubit does not require control over the intracluster
exchange interaction. Electric and magnetic fields necessary to effect quantum
gates need only be controlled on the length scale of the spin cluster rather
than the scale for a single spin. Here, we calculate the energy gap separating
the logical qubit states from the next excited state and the matrix elements
which determine quantum gate operation times. We discuss spin cluster qubits
formed by one- and two-dimensional arrays of s=1/2 spins as well as clusters
formed by spins s>1/2. We illustrate the advantages of spin cluster qubits for
various suggested implementations of spin qubits and analyze the scaling of
decoherence time with spin cluster size.Comment: 15 pages, 7 figures; minor change
Use of the Auto-inflammatory Disease Activity Index to monitor disease activity in patients with colchicine-resistant Familial Mediterranean Fever, Mevalonate Kinase Deficiency, and TRAPS treated with canakinumab
To evaluate the feasibility of the autoinflammatory disease activity index (AIDAI) as a tool to assess disease activity in patients with hereditary recurrent fever syndromes (HRFs) treated with canakinumab
Quantum Information Processing with Ferroelectrically Coupled Quantum Dots
I describe a proposal to construct a quantum information processor using
ferroelectrically coupled Ge/Si quantum dots. The spin of single electrons form
the fundamental qubits. Small (<10 nm diameter) Ge quantum dots are optically
excited to create spin polarized electrons in Si. The static polarization of an
epitaxial ferroelectric thin film confines electrons laterally in the
semiconductor; spin interactions between nearest neighbor electrons are
mediated by the nonlinear process of optical rectification. Single qubit
operations are achieved through "g-factor engineering" in the Ge/Si structures;
spin-spin interactions occur through Heisenberg exchange, controlled by
ferroelectric gates. A method for reading out the final state, while required
for quantum computing, is not described; electronic approaches involving single
electron transistors may prove fruitful in satisfying this requirement.Comment: 10 pages, 3 figure
Rewritable nanoscale oxide photodetector
Nanophotonic devices seek to generate, guide, and/or detect light using
structures whose nanoscale dimensions are closely tied to their functionality.
Semiconducting nanowires, grown with tailored optoelectronic properties, have
been successfully placed into devices for a variety of applications. However,
the integration of photonic nanostructures with electronic circuitry has always
been one of the most challenging aspects of device development. Here we report
the development of rewritable nanoscale photodetectors created at the interface
between LaAlO3 and SrTiO3. Nanowire junctions with characteristic dimensions
2-3 nm are created using a reversible AFM writing technique. These nanoscale
devices exhibit a remarkably high gain for their size, in part because of the
large electric fields produced in the gap region. The photoconductive response
is gate-tunable and spans the visible-to-near-infrared regime. The ability to
integrate rewritable nanoscale photodetectors with nanowires and transistors in
a single materials platform foreshadows new families of integrated
optoelectronic devices and applications.Comment: 5 pages, 5 figures. Supplementary Information 7 pages, 9 figure
Sept8/SEPTIN8 involvement in cellular structure and kidney damage is identified by genetic mapping and a novel human tubule hypoxic model.
Chronic kidney disease (CKD), which can ultimately progress to kidney failure, is influenced by genetics and the environment. Genes identified in human genome wide association studies (GWAS) explain only a small proportion of the heritable variation and lack functional validation, indicating the need for additional model systems. Outbred heterogeneous stock (HS) rats have been used for genetic fine-mapping of complex traits, but have not previously been used for CKD traits. We performed GWAS for urinary protein excretion (UPE) and CKD related serum biochemistries in 245 male HS rats. Quantitative trait loci (QTL) were identified using a linear mixed effect model that tested for association with imputed genotypes. Candidate genes were identified using bioinformatics tools and targeted RNAseq followed by testing in a novel in vitro model of human tubule, hypoxia-induced damage. We identified two QTL for UPE and five for serum biochemistries. Protein modeling identified a missense variant within Septin 8 (Sept8) as a candidate for UPE. Sept8/SEPTIN8 expression increased in HS rats with elevated UPE and tubulointerstitial injury and in the in vitro hypoxia model. SEPTIN8 is detected within proximal tubule cells in human kidney samples and localizes with acetyl-alpha tubulin in the culture system. After hypoxia, SEPTIN8 staining becomes diffuse and appears to relocalize with actin. These data suggest a role of SEPTIN8 in cellular organization and structure in response to environmental stress. This study demonstrates that integration of a rat genetic model with an environmentally induced tubule damage system identifies Sept8/SEPTIN8 and informs novel aspects of the complex gene by environmental interactions contributing to CKD risk
Telomeres and the natural lifespan limit in humans
An ongoing debate in demography has focused on whether the human lifespan has a maximal natural limit. Taking a mechanistic perspective, and knowing that short telomeres are associated with diminished longevity, we examined whether telomere length dynamics during adult life could set a maximal natural lifespan limit. We define leukocyte telomere length of 5 kb as the 'telomeric brink', which denotes a high risk of imminent death. We show that a subset of adults may reach the telomeric brink within the current life expectancy and more so for a 100-year life expectancy. Thus secular trends in life expectancy should confront a biological limit due to crossing the telomeric brink
Womenâs subsistence strategies predict fertility across cultures, but context matters
While it is commonly assumed that farmers have higher, and foragers lower, fertility compared to populations practicing other forms of subsistence, robust supportive evidence is lacking. We tested whether subsistence activitiesâincorporating market integrationâare associated with fertility in 10,250 women from 27 small-scale societies and found considerable variation in fertility. This variation did not align with group-level subsistence typologies. Societies labeled as âfarmersâ did not have higher fertility than others, while âforagersâ did not have lower fertility. However, at the individual level, we found strong evidence that fertility was positively associated with farming and moderate evidence of a negative relationship between foraging and fertility. Markers of market integration were strongly negatively correlated with fertility. Despite strong cross-cultural evidence, these relationships were not consistent in all populations, highlighting the importance of the socioecological context, which likely influences the diverse mechanisms driving the relationship between fertility and subsistence
How do firms comply with international sustainability standards? Processes and consequences of adopting the global reporting initiative
This paper addresses the issue of the influence of global governance institutions, particularly international sustainability standards, on a firmâs intra-organizational practices. More precisely, we provide an exploratory empirical view of the impact of the Global Reporting Initiative (GRI) on a multinational corporationâs (MNC) corporate social responsibility (CSR) management practices. We investigate standard compliance by comparing the stated intention of the use of the GRI with its actual use and the consequent effects within the firm. Based on an in-depth case study, our findings illustrate the processes and consequences of the translation of the GRI within the organization. We show that substantive standard adoption can lead to unintended consequences on CSR management practices, specifically it can influence the management structure and CSR committee function; the choice of CSR activities, the relationships between subsidiaries, the temporal dimension of CSR management, and the interpretation of CSR performance. We also highlight the need to look at the relationship dynamics (or lack of) between standards. Finally we illustrate and discuss the role of reporting and its influence on management in order to better understand the internal issues arising from compliance with standards
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