Optimal random search for a single hidden target

A single target is hidden at a location chosen from a predetermined probability distribution. Then, a searcher must find a second probability distribution from which random search points are sampled such that the target is found in the minimum number of trials. Here it will be shown that if the searcher must get very close to the target to find it, then the best search distribution is proportional to the square root of the target distribution. For a Gaussian target distribution, the optimum search distribution is approximately a Gaussian with a standard deviation that varies inversely with how close the searcher must be to the target to find it. For a network, where the searcher randomly samples nodes and looks for the fixed target along edges, the optimum is to either sample a node with probability proportional to the square root of the out degree plus one or not at all.Comment: 13 pages, 5 figure

Effects of an Educational Intervention on Exclusive Breastfeeding Rates in Marshallese Mothers Residing in the U.S.

Abstract Background: The Marshallese are one of the fastest growing migrant populations in the U.S. They have considerable health disparities despite their increasing access to health care. The Marshallese women in this population prefer to breastfeed, but have encountered many cultural barriers that have deterred them from exclusively breastfeeding for a significant amount of time. Breastfeeding is linked to many protective benefits for children’s health, such as decreasing the likelihood of obesity, even into the adult years. Objective: The purpose was to evaluate the impact on breastfeeding rates through implementation of a culturally significant educational intervention for the Marshallese women at a study hospital pursuing Baby-Friendly status. Methods: In this quasi-experimental study, the exclusive breastfeeding rates of the Marshallese women in Northwest Arkansas at the study hospital were collected prior to and after the interventions were implemented. The data gathered was compared to evaluate the effectiveness of the interventions. The intervention consisted of two parts: 1) a culturally significant educational video, and 2) a written pamphlet that the mothers were able to take home to reinforce the teaching. Results: Although the results were not statistically significant due to sample size, exposure to the intervention positively influenced breastfeeding practices during the hospital stay. Conclusion: It is hoped that this project will support the hospital in pursuit of Baby-Friendly status while also improving the exclusive breastfeeding rates and thus overall health of the Marshallese population in Northwest Arkansas

Effect of Framing of Reentry Program on Perceptions of Ex-Offenders

We examine the effect of the framing of reentry programs on participants’ perceptions of ex-offenders. Across four studies, participants expressed more favorable attitudes toward an ex-offender who completed a global citizen reentry program than an ex-offender who did not complete a reentry program. The results show that ex-offenders who complete a global citizen reentry program (vs. no program) are viewed as more likeable and similar to oneself, which then predicts reduced prejudice and greater endorsement to hire the ex-offender. The results are discussed in relation to the crossed categorization model of prejudice reduction

Transient interference of transmission and incidence

Due to a transient quantum interference during a wavepacket collision with a potential barrier, a particular momentum, that depends on the potential parameters but is close to the initial average momentum, becomes suppressed. The hole left pushes the momentum distribution outwards leading to a significant constructive enhancement of lower and higher momenta. This is explained in the momentum complex-plane language in terms of a saddle point and two contiguous ``structural'' poles, which are not associated with resonances but with incident and transmitted components of the wavefunction.Comment: 4 pages of text, 6 postscript figures, revte

Long-acting nifedipine in the management of the hypertensive patient

Hypertension is a global condition affecting billions worldwide. It is a significant contributor to cardiovascular events, cardiac death and kidney disease. A number of medication classes exist to aid healthcare providers and their patients in controlling hypertension. Nifedipine, a dihydropyridine calcium channel blocker, was once one of the most widely used medications for hypertension, but safety and tolerability concerns along with the introduction of new classes of antihypertensive medications and an increasing pool of data showing mortality benefit of other classes caused nifedipine to fall out of favor. More recently, long-acting formulations were developed and made available to clinicians. These newer formulations were designed to address many of the concerns raised by earlier formulations of nifedipine. Numerous clinical trials have been conducted comparing long-acting nifedipine to many of the more commonly prescribed antihypertensive medications. This review will address the pharmacology, pharmacokinetics and the available clinical trial data on long-acting nifedipine and summarize its role in the management of hypertension

Single-electron latch with granular film charge leakage suppressor

A single-electron latch is a device that can be used as a building block for Quantum-dot Cellular Automata (QCA) circuits. It consists of three nanoscale metal "dots" connected in series by tunnel junctions; charging of the dots is controlled by three electrostatic gates. One very important feature of a single-electron latch is its ability to store ("latch") information represented by the location of a single electron within the three dots. To obtain latching, the undesired leakage of charge during the retention time must be suppressed. Previously, to achieve this goal, multiple tunnel junctions were used to connect the three dots. However, this method of charge leakage suppression requires an additional compensation of the background charges affecting each parasitic dot in the array of junctions. We report a single-electron latch where a granular metal film is used to fabricate the middle dot in the latch which concurrently acts as a charge leakage suppressor. This latch has no parasitic dots, therefore the background charge compensation procedure is greatly simplified. We discuss the origins of charge leakage suppression and possible applications of granular metal dots for various single-electron circuits.Comment: 21 pages, 4 figure

A spin field effect transistor for low leakage current

In a spin field effect transistor, a magnetic field is inevitably present in the channel because of the ferromagnetic source and drain contacts. This field causes random unwanted spin precession when carriers interact with non-magnetic impurities. The randomized spins lead to a large leakage current when the transistor is in the ``off''-state, resulting in significant standby power dissipation. We can counter this effect of the magnetic field by engineering the Dresselhaus spin-orbit interaction in the channel with a backgate. For realistic device parameters, a nearly perfect cancellation is possible, which should result in a low leakage current.Comment: To appear in Physica E. The revised version has additional material which addresses the issue of which way the contacts should be magnetized in a Spin Field Effect Transistor. This was neither addressed in the previous version, nor in the upcoming journal pape