3,987 research outputs found
Federalism and the Treaty Power: Breaking the âBond(S)â Between Nations: The Treaty Power and Status of Forces Agreements
Federalism and the Treaty Power: Breaking the âBond(S)â Between Nations: The Treaty Power and Status of Forces Agreements
Resistivity of Graphene Nanoribbon Interconnects
Graphene nanoribbon interconnects are fabricated, and the extracted
resistivity is compared to that of Cu. It is found that the average resistivity
at a given line-width (18nm<W<52nm) is about 3X that of a Cu wire, whereas the
best GNR has a resistivity comparable to that of Cu. The conductivity is found
to be limited by impurity scattering as well as LER scattering; as a result,
the best reported GNR resistivity is 3X the limit imposed by substrate phonon
scattering. This study reveals that even moderate-quality graphene nanowires
have the potential to outperform Cu for use as on-chip interconnects.Comment: 10 pages, 3 figures, to be published in IEEE Electron Device Letter
Breakdown Current Density of Graphene Nano Ribbons
Graphene nanoribbons (GNRs) with widths down to 16 nm have been characterized
for their current-carrying capacity. It is found that GNRs exhibit an
impressive breakdown current density, on the order of 10^8 A/cm2. The breakdown
current density is found to have a reciprocal relationship to GNR resistivity
and the data fit points to Joule heating as the likely mechanism of breakdown.
The superior current-carrying capacity of GNRs will be valuable for their
application in on-chip electrical interconnects. The thermal conductivity of
sub-20 nm graphene ribbons is found to be more than 1000 W/m-K
Comparison of ultracold neutron sources for fundamental physics measurements
Ultracold neutrons (UCNs) are key for precision studies of fundamental
parameters of the neutron and in searches for new CP violating processes or
exotic interactions beyond the Standard Model of particle physics. The most
prominent example is the search for a permanent electric dipole moment of the
neutron (nEDM). We have performed an experimental comparison of the leading UCN
sources currently operating. We have used a 'standard' UCN storage bottle with
a volume of 32 liters, comparable in size to nEDM experiments, which allows us
to compare the UCN density available at a given beam port.Comment: 20 pages, 30 Figure
Experimental compressive phase space tomography
Phase space tomography estimates correlation functions entirely from
snapshots in the evolution of the wave function along a time or space variable.
In contrast, traditional interferometric methods require measurement of
multiple two-point correlations. However, as in every tomographic formulation,
undersampling poses a severe limitation. Here we present the first, to our
knowledge, experimental demonstration of compressive reconstruction of the
classical optical correlation function, i.e. the mutual intensity function. Our
compressive algorithm makes explicit use of the physically justifiable
assumption of a low-entropy source (or state.) Since the source was directly
accessible in our classical experiment, we were able to compare the compressive
estimate of the mutual intensity to an independent ground-truth estimate from
the van Cittert-Zernike theorem and verify substantial quantitative
improvements in the reconstruction
Specific premature epigenetic aging of cartilage in osteoarthritis
Osteoarthritis (OA) is a disease affecting multiple tissues of the joints in the elderly, but most notably articular cartilage. Premature biological aging has been described in this tissue and in blood cells, suggesting a systemic component of premature aging in the pathogenesis of OA. Here, we have explored epigenetic aging in OA at the local (cartilage and bone) and systemic (blood) levels. Two DNA methylation ageâmeasures (DmAM) were used: the multiâtissue age estimator for cartilage and bone; and a bloodâspecific biomarker for blood. Differences in DmAM between OA patients and controls showed an accelerated aging of 3.7 years in articular cartilage (95 % CI = 1.1 to 6.3, P = 0.008) of OA patients. By contrast, no difference in epigenetic aging was observed in bone (0.04 years; 95 % CI = â1.8 to 1.9, P = 0.3) and in blood (â0.6 years; 95 % CI = â1.5 to 0.3, P = 0.2) between OA patients and controls. Therefore, premature epigenetic aging according to DNA methylation changes was specific of OA cartilage, adding further evidence and insight on premature aging of cartilage as a component of OA pathogenesis that reflects damage and vulnerability
Dimensionality and dynamics in the behavior of C. elegans
A major challenge in analyzing animal behavior is to discover some underlying
simplicity in complex motor actions. Here we show that the space of shapes
adopted by the nematode C. elegans is surprisingly low dimensional, with just
four dimensions accounting for 95% of the shape variance, and we partially
reconstruct "equations of motion" for the dynamics in this space. These
dynamics have multiple attractors, and we find that the worm visits these in a
rapid and almost completely deterministic response to weak thermal stimuli.
Stimulus-dependent correlations among the different modes suggest that one can
generate more reliable behaviors by synchronizing stimuli to the state of the
worm in shape space. We confirm this prediction, effectively "steering" the
worm in real time.Comment: 9 pages, 6 figures, minor correction
The Relationship between Concurrent Substance Use Disorders and Eating Disorders with Personality Disorders
Objective: The current pilot study investigated whether patients with concurrent substance use disorders and eating disorders (SUD and ED) who experienced a reduction in SUD and ED symptoms following treatment for SUD and ED also experienced a reduction in personality disorder (PD) symptoms. Method: Twenty patients with SUD and ED and PD were assessed pre and post treatment using clinical interviews, self-report questionnaires, and a therapist questionnaire on DSM-IV-TR symptoms for PD. Results: Symptoms for the personality disorders were reduced following treatment. This reduction was correlated with a decrease in the number of symptoms of ED at post treatment. Discussion: Chronic concurrent SUD and ED may make it difficult to separate PD symptoms from co-occurring disorders. Many features attributed to PDs may be reduced when problematic substance use and disordered eating are addressed, a fact that may increase clinician and patientsâoptimism about therapeutic change
The Multiscale Systems Immunology project: software for cell-based immunological simulation
<p>Abstract</p> <p>Background</p> <p>Computer simulations are of increasing importance in modeling biological phenomena. Their purpose is to predict behavior and guide future experiments. The aim of this project is to model the early immune response to vaccination by an agent based immune response simulation that incorporates realistic biophysics and intracellular dynamics, and which is sufficiently flexible to accurately model the multi-scale nature and complexity of the immune system, while maintaining the high performance critical to scientific computing.</p> <p>Results</p> <p>The Multiscale Systems Immunology (MSI) simulation framework is an object-oriented, modular simulation framework written in C++ and Python. The software implements a modular design that allows for flexible configuration of components and initialization of parameters, thus allowing simulations to be run that model processes occurring over different temporal and spatial scales.</p> <p>Conclusion</p> <p>MSI addresses the need for a flexible and high-performing agent based model of the immune system.</p
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