Resonant electron transmission through a finite quantum spin chain

Electron transport in a finite one dimensional quantum spin chain (with ferromagnetic exchange) is studied within an $s-d$ exchange Hamiltonian. Spin transfer coefficients strongly depend on the sign of the $s-d$ exchange constant. For a ferromagnetic coupling, they exhibit a novel resonant pattern, reflecting the salient features of the combined electron-spin system. Spin-flip processes are inelastic and feasible at finite voltage or at finite temperature.Comment: 4 pages including 4 .eps figure

Elements Affecting Disclosure of Abusive Dating Relationships: Attachment Style Sex of Research Participant and Importance of Disclosure Target

This study examined the influence of attachment style, sex of research participant, and relationship importance of disclosure target on the self-disclosure of abuse in dating relationships using a hypothetical dating aggression scenario. The two dependent variables were willingness to disclose and perceived helpfulness of self-disclosure. Research participants were classified according to Bartholomew\u27s model of adult attachment (i.e., secure, preoccupied, dismissing, or fearful). Attachment style of research participants significantly affected perceived helpfulness of self-disclosure. Fearful participants perceived the most helpfulness from disclosure and were the most willing to self-disclose. Sex of research participant did not have a significant effect on willingness to self-disclose or perceived helpfulness of self-disclosure. Male and female research participants showed nearly identical disclosure patterns except that female participants were more affected by the relationship importance of disclosure targets. Female research participants were more willing to self-disclose and perceived more helpfulness from disclosing to important target persons. Female research participants were less willing to self-disclose and perceived less helpfulness from disclosing to unimportant target persons. Relationship importance of disclosure target had significant effects for both willingness to self-disclose and perceived helpfulness of self-disclosure. Research participants were more willing to self-disclose and perceived more helpfulness when disclosing to targets they judged important (significant) as compared to unimportant (non-significant) targets. Overall, the results suggested that attachment style and relationship importance of disclosure target are valuable concepts for understanding self-disclosure patterns. Results also question the relevance of sex of research participant for understanding self-disclosure patterns except when sex of research participant is interacting with importance of disclosure target

An Exploration of the State-Trait Continuum in Counseling and Positive Psychology

Counselors value remaining positive in the face of adversity. Consequently, positive psychology has placed an emphasis on uncovering how long-enduring positive traits (e.g., hope, wisdom, and creativity) can be developed from short-term positive states. This search has resulted in positive psychology\u27s conceptualization of a state-trait continuum. This study explores the state-trait continuum by examining possible quantitative relationships between a state instrument (the Learning Environment Preferences) and a trait instrument (the Myers-Briggs Type Indicator). Research question 1 found a significant predictive relationship between two MBTI scales (S-N and J-P) and the LEP\u27s cognitive complexity index. Research question 2 found a significant relationship suggesting that very clear preference scores across the MBTI dichotomies are associated with higher cognitive complexity

BMQ

BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals

Partitioning Evapotranspiration in Semiarid Grassland and Shrubland Ecosystems Using Diurnal Surface Temperature Variation

The encroachment of woody plants in grasslands across the Western U.S. will affect soil water availability by altering the contributions of evaporation (E) and transpiration (T) to total evapotranspiration (ET). To study this phenomenon, a network of flux stations is in place to measure ET in grass- and shrub-dominated ecosystems throughout the Western U.S. A method is described and tested here to partition the daily measurements of ET into E and T based on diurnal surface temperature variations of the soil and standard energy balance theory. The difference between the mid-afternoon and pre-dawn soil surface temperature, termed Apparent Thermal Inertia (I(sub A)), was used to identify days when E was negligible, and thus, ET=T. For other days, a three-step procedure based on energy balance equations was used to estimate Qe contributions of daily E and T to total daily ET. The method was tested at Walnut Gulch Experimental Watershed in southeast Arizona based on Bowen ratio estimates of ET and continuous measurements of surface temperature with an infrared thermometer (IRT) from 2004- 2005, and a second dataset of Bowen ratio, IRT and stem-flow gage measurements in 2003. Results showed that reasonable estimates of daily T were obtained for a multi-year period with ease of operation and minimal cost. With known season-long daily T, E and ET, it is possible to determine the soil water availability associated with grass- and shrub-dominated sites and better understand the hydrologic impact of regional woody plant encroachment

The potential for stabilizing Amundsen Sea glaciers via underwater curtains

Rapid sea level rise due to an ice sheet collapse has the potential to be extremely damaging the coastal communities and infrastructure. Blocking deep warm water with thin flexible buoyant underwater curtains may reduce melting of buttressing ice shelves and thereby slow the rate of sea level rise. Here, we use new multibeam bathymetric datasets, combined with a cost-benefit model, to evaluate potential curtain routes in the Amundsen Sea. We organize potential curtain routes along a "difficulty ladder"representing an implementation pathway that might be followed as technological capabilities improve. The first curtain blocks a single narrow (5 km) submarine choke point that represents the primary warm water inflow route towards western Thwaites Glacier, the most vulnerable part of the most vulnerable glacier in Antarctica. Later curtains cross larger and deeper swaths of seabed, thus increasing their cost, while also protecting more of the ice sheet, increasing their benefit. In our simple cost-benefit analysis, all of the curtain routes achieve their peak value at target blocking depths between 500 and 550 m. The favorable cost-benefit ratios of these curtain routes, along with the trans-generational and societal equity of preserving the ice sheets near their present state, argue for increased research into buoyant curtains as a means of ice sheet preservation, including high-resolution fluid-structural and oceanographic modeling of deep water flow over and through the curtains, and coupled ice-ocean modeling of the dynamic response of the ice sheet

A Phase I Double Blind, Placebo-Controlled, Randomized Study of a Multigenic HIV-1 Adenovirus Subtype 35 Vector Vaccine in Healthy Uninfected Adults

<div><h3>Background</h3><p>We conducted a phase I, randomized, double-blind, placebo-controlled trial to assess the safety and immunogenicity of escalating doses of two recombinant replication defective adenovirus serotype 35 (Ad35) vectors containing gag, reverse transcriptase, integrase and nef (Ad35-GRIN) and env (Ad35-ENV), both derived from HIV-1 subtype A isolates. The trial enrolled 56 healthy HIV-uninfected adults.</p> <h3>Methods</h3><p>Ad35-GRIN/ENV (Ad35-GRIN and Ad35-ENV mixed in the same vial in equal proportions) or Ad35-GRIN was administered intramuscularly at 0 and 6 months. Participants were randomized to receive either vaccine or placebo (10/4 per group, respectively) within one of four dosage groups: Ad35-GRIN/ENV 2×10⁹ (A), 2×10¹⁰ (B), 2×10¹¹ (C), or Ad35-GRIN 1×10¹⁰ (D) viral particles.</p> <h3>Results</h3><p>No vaccine-related serious adverse event was reported. Reactogenicity events reported were dose-dependent, mostly mild or moderate, some severe in Group C volunteers, all transient and resolving spontaneously. IFN-γ ELISPOT responses to any vaccine antigen were detected in 50, 56, 70 and 90% after the first vaccination, and in 75, 100, 88 and 86% of Groups A–D vaccine recipients after the second vaccination, respectively. The median spot forming cells (SFC) per 10⁶ PBMC to any antigen was 78–139 across Groups A–C and 158–174 in Group D, after each of the vaccinations with a maximum of 2991 SFC. Four to five HIV proteins were commonly recognized across all the groups and over multiple timepoints. CD4+ and CD8+ T-cell responses were polyfunctional. Env antibodies were detected in all Group A–C vaccinees and Gag antibodies in most vaccinees after the second immunization. Ad35 neutralizing titers remained low after the second vaccination.</p> <h3>Conclusion/Significance</h3><p>Ad35-GRIN/ENV reactogenicity was dose-related. HIV-specific cellular and humoral responses were seen in the majority of volunteers immunized with Ad35-GRIN/ENV or Ad35-GRIN and increased after the second vaccination. T-cell responses were broad and polyfunctional.</p> <h3>Trial Registration</h3><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/ct2/results?term=NCT00851383">NCT00851383</a></p> </div

The Importance of Formative Assessment in Science and Engineering Ethics Education: Some Evidence and Practical Advice

Recent research in ethics education shows a potentially problematic variation in content, curricular materials, and instruction. While ethics instruction is now widespread, studies have identified significant variation in both the goals and methods of ethics education, leaving researchers to conclude that many approaches may be inappropriately paired with goals that are unachievable. This paper speaks to these concerns by demonstrating the importance of aligning classroom-based assessments to clear ethical learning objectives in order to help students and instructors track their progress toward meeting those objectives. Two studies at two different universities demonstrate the usefulness of classroom-based, formative assessments for improving the quality of students’ case responses in computational modeling and research ethics

Political Polarization as a Constraint on Corruption: A Cross-National Comparison

Efforts to explain corruption have increased dramatically in recent years. The interest stems from the increasing weight economists assign to corruption when explaining economic growth. Much research focuses on how political institutions influence perceptions of corruption. We move this debate in a new direction by addressing a previously ignored dimension: ideological polarization. We contend perceptions of corruption are determined not only by specific institutional features of the political system–such as elements of voting systems, ballot structures, or separation of powers–but by who sits at the controls. We employ panel data from a broad variety of countries to test our theoretical argument. Contrary to recent findings by both economists and political scientists, we show that ideological polarization predicts perceptions of corruption