5,083 research outputs found
Qubit Channels Can Require More Than Two Inputs to Achieve Capacity
We give examples of qubit channels that require three input states in order
to achieve the Holevo capacity.Comment: RevTex, 5 page, 4 figures
Identifying Arkansas Food Desert Blocks Suitable for a Peer-to-Peer Modeled Food Redistribution Program
Abstract
Nearly 10% of Americans reside in low-income urban food deserts which are low-income areas that lack access to affordable and nutritious foods. Food deserts in Arkansas contribute to a food insecurity rate above the national average, making it one of the most food insecure states in the country. Increased internet usage and consumer interest in sharing based companies contribute to the idea of a sharing, or peer-to-peer (P2P) style food redistribution program. The objective of this study is to identify which of the 186,211census blocks in the state of Arkansas are food deserts and best suited for and in the most need, based on an identified set of criteria, of a P2P food redistribution program. A multi-criteria decision analysis was conducted using population, internet access, vulnerable communities, and vehicle availability as criteria. Results suggest that based upon the close proximity of priority areas, transportation access, ethnic/racial diversity, and the number of possible collection locations, Pulaski County be targeted for a P2P food redistribution pilot program
Relationship between structure and function of neurons in the rat rostral nucleus tractus solitarii
To investigate the relationship between the structure and function of neurons in the rostral (gustatory) nucleus tractus solitarii (rNTS), we analyzed the morphological and biophysical properties of rNTS neurons by performing whole-cell recordings in a brain slice preparation. Overall, neurons (n=58) had a mean somal diameter of 16 Μm, an average dendritic length of 598 Μm, an average dendritic thickness of 0.91 Μm, and a spine density of 0.037 spines/Μm. Neurons were separated into three groups (elongate, miltipolar, and ovoid) on the basis of previously established morphological criteria. The highest percentage (49%) of neurons were classified as ovoid, while 35% were multipolar and only 16% were elongate. The most frequently ovserved firing pattern, in all three cell types, elicited by a 1,200 ms, 100 pA depolarizing current pulse was a regularly firing spike train. However, the intrinsic firing properties of the remaining neurons were different. Thirty-one percent of the ovoid neurons responded with a short burst of action potentials and 44% of the elongate neurons showed a delay in the onset of the spike train following a hyperpolarizing prepulse. Less than 16% of the multipolar neurons demonstrated either of these firing characteristics. Therefore, rNTS neurons with similar morphology do not have unique biophysical properties. However, the data suggest that there may be subpopulations of the three morphological types, each of which displays a different firing pattern. Since the structure and function of the three morphological groups were not strictly correlated, these subpopulations may represent functional groups. © 1994 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50061/1/903440105_ftp.pd
A combined NMR and DFT study of Narrow Gap Semiconductors: The case of PbTe
In this study we present an alternative approach to separating contributions
to the NMR shift originating from the Knight shift and chemical shielding by a
combination of experimental solid-state NMR results and ab initio calculations.
The chemical and Knight shifts are normally distinguished through detailed
studies of the resonance frequency as function of temperature and carrier
concentration, followed by extrapolation of the shift to zero carrier
concentration. This approach is time-consuming and requires studies of multiple
samples. Here, we analyzed Pb and Te NMR spin-lattice
relaxation rates and NMR shifts for bulk and nanoscale PbTe. The shifts are
compared with calculations of the Pb and Te chemical shift
resonances to determine the chemical shift at zero charge carrier
concentration. The results are in good agreement with literature values from
carrier concentration-dependent studies. The measurements are also compared to
literature reports of the Pb and Te Knight shifts of - and
-type PbTe semiconductors. The literature data have been converted to the
currently accepted shift scale. We also provide possible evidence for the
"self-cleaning effect" property of PbTe nanocrystals whereby defects are
removed from the core of the particles, while preserving the crystal structure.Comment: 34 pages, 9 figure
Determinants of physical activity promotion by smoking cessation advisors as an aid for quitting: Support for the Transtheoretical Model
Objectives: Physical activity (PA) can reduce cigarette cravings and aid quitting but little is known about its promotion by smoking cessation advisors. This study aimed to: (1) determine the extent to which smoking cessation advisors promote PA; and (2) examine the relationship between PA promotion as a cessation aid and advisor characteristics and cognitions, within the Transtheoretical
Model (TM) framework.
Methods: Self-report surveys assessing PA promotion, TM variables, advisors’ own PA levels and demographics were completed by 170 advisors in England and Scotland.
Results: Advisors reported spending 29 minutes promoting PA over a 6/7-week clinic. Those in later stages of readiness for promoting PA as a cessation aid and those spending more time promoting PA held more positive beliefs regarding pros and cons, self-efficacy, outcome efficacy and importance
of PA within smoking cessation. Time spent promoting PA and stage of readiness were strongly associated. There was a trend for the more physically active advisors to promote PA more often.
Conclusions: About half the advisors promoted PA and TM variables predicted this variability.
Practice Implications: PA promotion among smoking cessation advisors may be facilitated by enhancing self-efficacy, outcome efficacy and pro and con-beliefs related to PA promotion
The Retail FX Trader: Random Trading and the Negative Sum Game
With the internet boom of early 2000 making access to trading the Foreign Exchange (FX) market far simpler for members of the general public, the growth of 'retail' FX trading continues, with daily transaction volumes as high as $200 billion. Potential new entrants to the retail FX trading world may come from the recent UK pension deregulations, further increasing the volumes. The attraction of FX trading is that it offers high returns and whilst it has been understood that it is high-risk in nature, the rewards are seen as being commensurately high for the 'skilled and knowledgeable' trader who has an edge over other market participants. This paper analyses a number of independent sources of data and previous research, to examine the profitability of the Retail FX trader and compares the results with that of a simulated random trading models. This paper finds evidence to suggest that whilst approximately 20% of traders can expect to end up with a profitable account, around 40% might expect their account to be subject to a margin call. This paper finds a strong correlation between the overall profitability of traders and impact of the cost of the bid-ask spread, whilst finding little if any evidence that retail FX traders, when viewed as a group, are achieving results better than that from random trading
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