799 research outputs found
American Conservatism and Government Funding of the Social Sciences and the Arts
http://deepblue.lib.umich.edu/bitstream/2027.42/51038/1/266.pd
Electrodeposition of Zinc onto Au(111) and Au(100) from the Ionic Liquid [MPPip][TFSI]
The improvement of rechargeable zinc/air batteries was a hot topic in recent years. Predominantly, the influence of water and additives on the structure of the Zn deposit and the possible dendrite formation were studied. However, the effect of the surface structure of the underlying substrate was not focused on in detail, yet. We now show the differences in electrochemical deposition of Zn onto Au(111) and Au(100) from the ionic liquid N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide. The fundamental processes were initially characterized via cyclic voltammetry and in situ scanning tunnelling microscopy. Bulk deposits were then examined using Auger electron spectroscopy and scanning electron microscopy. Different structures of Zn deposits are observed during the initial stages of electrocrystallisation on both electrodes, which reveals the strong influence of the crystallographic orientation on the metal deposition of zinc on gold
Urinary peptidomics analysis reveals proteases involved in diabetic nephropathy
Mechanisms underlying the onset and progression of nephropathy in diabetic patients are not fully elucidated. Deregulation of proteolytic systems is a known path leading to disease manifestation, therefore we hypothesized that proteases aberrantly expressed in diabetic nephropathy (DN) may be involved in the generation of DN-associated peptides in urine. We compared urinary peptide profiles of DN patients (macroalbuminuric, n = 121) to diabetic patients with no evidence of DN (normoalbuminuric, n = 118). 302 sequenced, differentially expressed peptides (adjusted p-value < 0.05) were analysed with the Proteasix tool predicting proteases potentially involved in their generation. Activity change was estimated based on the change in abundance of the investigated peptides. Predictions were correlated with transcriptomics (Nephroseq) and relevant protein expression data from the literature. This analysis yielded seventeen proteases, including multiple forms of MMPs, cathepsin D and K, kallikrein 4 and proprotein convertases. The activity of MMP-2 and MMP-9, predicted to be decreased in DN, was investigated using zymography in a DN mouse model confirming the predictions. Collectively, this proof-of-concept study links urine peptidomics to molecular changes at the tissue level, building hypotheses for further investigation in DN and providing a workflow with potential applications to other diseases
Analytical and Numerical Study of Photocurrent Transients in Organic Polymer Solar Cells
This article is an attempt to provide a self consistent picture, including
existence analysis and numerical solution algorithms, of the mathematical
problems arising from modeling photocurrent transients in Organic-polymer Solar
Cells (OSCs). The mathematical model for OSCs consists of a system of nonlinear
diffusion-reaction partial differential equations (PDEs) with electrostatic
convection, coupled to a kinetic ordinary differential equation (ODE). We
propose a suitable reformulation of the model that allows us to prove the
existence of a solution in both stationary and transient conditions and to
better highlight the role of exciton dynamics in determining the device turn-on
time. For the numerical treatment of the problem, we carry out a temporal
semi-discretization using an implicit adaptive method, and the resulting
sequence of differential subproblems is linearized using the Newton-Raphson
method with inexact evaluation of the Jacobian. Then, we use exponentially
fitted finite elements for the spatial discretization, and we carry out a
thorough validation of the computational model by extensively investigating the
impact of the model parameters on photocurrent transient times.Comment: 20 pages, 11 figure
Multiscale Modeling and Simulation of Organic Solar Cells
In this article, we continue our mathematical study of organic solar cells
(OSCs) and propose a two-scale (micro- and macro-scale) model of heterojunction
OSCs with interface geometries characterized by an arbitrarily complex
morphology. The microscale model consists of a system of partial and ordinary
differential equations in an heterogeneous domain, that provides a full
description of excitation/transport phenomena occurring in the bulk regions and
dissociation/recombination processes occurring in a thin material slab across
the interface. The macroscale model is obtained by a micro-to-macro scale
transition that consists of averaging the mass balance equations in the normal
direction across the interface thickness, giving rise to nonlinear transmission
conditions that are parametrized by the interfacial width. These conditions
account in a lumped manner for the volumetric dissociation/recombination
phenomena occurring in the thin slab and depend locally on the electric field
magnitude and orientation. Using the macroscale model in two spatial
dimensions, device structures with complex interface morphologies, for which
existing data are available, are numerically investigated showing that, if the
electric field orientation relative to the interface is taken into due account,
the device performance is determined not only by the total interface length but
also by its shape
The relationships between problem characteristics, achievement-related behaviors, and academic achievement in problem-based learning
This study investigated the influence of five problem characteristics on students' achievement-related classroom behaviors and academic achievement. Data from 5,949 polytechnic students in PBL curricula across 170 courses were analyzed by means of path analysis. The five problem characteristics were: (1) problem clarity, (2) problem familiarity, (3) the extent to which the problem stimulated group discussion, (4) self-study, and (5) identification of learning goals. The results showed that problem clarity led to more group discussion, identification of learning goals, and self-study than problem familiarity. On the other hand, problem familiarity had a stronger and direct impact on academic achievement
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
The Problem of Experience in the Study of Organizations
This paper deals with the fact that we cannot experience large organizations directly, in the same way as we can experience individuals or small groups, and that this non-experientiability has certain implications for our scientific theories of organizations. Whereas a science is animated by a constructive interplay of theory concepts and experience concepts, the study of organizations has been confined to theory concepts alone. Implications of this analysis for developing a science of organizations are considered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68303/2/10.1177_017084069301400102.pd
Clostridium septicum growth from a total knee arthroplasty associated with intestinal malignancy: a case report
Neural Correlates of Visual Motion Prediction
Predicting the trajectories of moving objects in our surroundings is important for many life scenarios, such as driving, walking, reaching, hunting and combat. We determined human subjects’ performance and task-related brain activity in a motion trajectory prediction task. The task required spatial and motion working memory as well as the ability to extrapolate motion information in time to predict future object locations. We showed that the neural circuits associated with motion prediction included frontal, parietal and insular cortex, as well as the thalamus and the visual cortex. Interestingly, deactivation of many of these regions seemed to be more closely related to task performance. The differential activity during motion prediction vs. direct observation was also correlated with task performance. The neural networks involved in our visual motion prediction task are significantly different from those that underlie visual motion memory and imagery. Our results set the stage for the examination of the effects of deficiencies in these networks, such as those caused by aging and mental disorders, on visual motion prediction and its consequences on mobility related daily activities
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