Disentanglement and Decoherence without dissipation at non-zero temperatures

Decoherence is well understood, in contrast to disentanglement. According to common lore, irreversible coupling to a dissipative environment is the mechanism for loss of entanglement. Here, we show that, on the contrary, disentanglement can in fact occur at large enough temperatures $T$ even for vanishingly small dissipation (as we have shown previously for decoherence). However, whereas the effect of $T$ on decoherence increases exponentially with time, the effect of $T$ on disentanglement is constant for all times, reflecting a fundamental difference between the two phenomena. Also, the possibility of disentanglement at a particular $T$ increases with decreasing initial entanglement.Comment: 3 page

A translator writing system for microcomputer high-level languages and assemblers

In order to implement high level languages whenever possible, a translator writing system of advanced design was developed. It is intended for routine production use by many programmers working on different projects. As well as a fairly conventional parser generator, it includes a system for the rapid generation of table driven code generators. The parser generator was developed from a prototype version. The translator writing system includes various tools for the management of the source text of a compiler under construction. In addition, it supplies various default source code sections so that its output is always compilable and executable. The system thereby encourages iterative enhancement as a development methodology by ensuring an executable program from the earliest stages of a compiler development project. The translator writing system includes PASCAL/48 compiler, three assemblers, and two compilers for a subset of HAL/S

Two-fluid model of the solar corona

A simple model of the lower corona which allows for a possible difference in the electron and proton temperatures is analyzed. With the introduction of a phenomenological heating term, temperature and density profiles are calculated for several different cases. It is found that, under certain circumstances, the electron and proton temperatures may differ significantly

A comparative analysis of rawinsonde and NIMBUS 6 and TIROS N satellite profile data

Comparisons are made between rawinsonde and satellite profiles in seven areas for a wide range of surface and weather conditions. Variables considered include temperature, dewpoint temperature, thickness, precipitable water, lapse rate of temperature, stability, geopotential height, mixing ratio, wind direction, wind speed, and kinematic parameters, including vorticity and the advection of vorticity and temperature. In addition, comparisons are made in the form of cross sections and synoptic fields for selected variables. Sounding data from the NIMBUS 6 and TIROS N satellites were used. Geostrophic wind computed from smoothed geopotential heights provided large scale flow patterns that agreed well with the rawinsonde wind fields. Surface wind patterns as well as magnitudes computed by use of the log law to extrapolate wind to a height of 10 m agreed with observations. Results of this study demonstrate rather conclusively that satellite profile data can be used to determine characteristics of large scale systems but that small scale features, such as frontal zones, cannot yet be resolved

A Research-Based Curriculum for Teaching the Photoelectric Effect

Physics faculty consider the photoelectric effect important, but many erroneously believe it is easy for students to understand. We have developed curriculum on this topic including an interactive computer simulation, interactive lectures with peer instruction, and conceptual and mathematical homework problems. Our curriculum addresses established student difficulties and is designed to achieve two learning goals, for students to be able to (1) correctly predict the results of photoelectric effect experiments, and (2) describe how these results lead to the photon model of light. We designed two exam questions to test these learning goals. Our instruction leads to better student mastery of the first goal than either traditional instruction or previous reformed instruction, with approximately 85% of students correctly predicting the results of changes to the experimental conditions. On the question designed to test the second goal, most students are able to correctly state both the observations made in the photoelectric effect experiment and the inferences that can be made from these observations, but are less successful in drawing a clear logical connection between the observations and inferences. This is likely a symptom of a more general lack of the reasoning skills to logically draw inferences from observations.Comment: submitted to American Journal of Physic

A Conversation Among Deans on Results: Legal Education, Institutional Change, and a Decade of Gender Studies

On March 10, 2006, the Harvard Journal of Law & Gender, cosponsoring with the Harvard Civil Rights-Civil Liberties Law Review and the Harvard Law Review, hosted a conference, Results: Legal Education, Institutional Change, and a Decade of Gender Studies, to address the number of student experience studies that detail women\u27s lower performance in and dissatisfaction with law school. Rather than advocate for a particular set of responses to the different experiences of men and women in legal education, this conference sought to foster a discussion about the institutional challenges these patterns highlight. As one means of accomplishing this end, law school deans from across the country spoke about their strategies to change legal education. Edward Rubin, dean of Vanderbilt Law School, discussed how law school still acts as a rite of passage that is more suited to an era when the public sphere was male-dominated, and suggested reforms in legal curriculum in light of changes in the legal profession. W. H. Knight, dean of the University of Washington School of Law, concentrated on how law school culture might change as to become more rewarding for students and more inclusive of students from diverse backgrounds. Katherine Bartlett, dean of Duke Law School, spoke about the role of technology in infusing the context in which law operates in the study of law, as well as the Duke Blueprint, a mission statement that helps students (and faculty) examine the motives and values they will bring to becoming a lawyer

Sex distribution of offspring-parents obesity: Angel's hypothesis revisited

This study, which is based on two cross sectional surveys' data, aims to establish any effect of parental obesity sex distribution of offspring and to replicate the results that led to the hypothesis that obesity may be associated with sex-linked recessive lethal gene. A representative sample of 4,064 couples living in Renfrew/Paisley, Scotland was surveyed 1972-1976. A total of 2,338 offspring from 1,477 of the couples screened in 1972-1976, living in Paisley, were surveyed in 1996. In this study, males represented 47.7% among the total offspring of the couples screened in 1972-1976. In the first survey there was a higher male proportion of offspring (53%, p < 0.05) from parents who were both obese, yet this was not significant after adjustment for age of parents. Also, there were no other significant differences in sex distribution of offspring according to body mass index, age, or social class of parents. The conditions of the original 1949 study of Angel (1949) (which proposed a sex-linked lethal recessive gene) were simulated by selecting couples with at least one obese daughter. In this subset, (n = 409), obesity in fathers and mothers was associated with 26% of offspring being male compared with 19% of offspring from a non-obese father and obese mother. Finally we conclude that families with an obese father have a higher proportion of male offspring. These results do not support the long-established hypotheses of a sex-linked recessive lethal gene in the etiology of obesity

An evaluation of orange and clear traps with pear ester to monitor codling moth (Lepidoptera: Tortricidae) in apple orchards

Barros-Parada, W (Barros-Parada, Wilson)[ 1 ] ; Knight, AL (Knight, Alan L.)[ 2 ] ; Basoalto, E (Basoalto, Esteban)[ 3 ] ; Fuentes-Contreras, E (Fuentes-Contreras, Eduardo)[ 1 ] Univ Talca, Fac Ciencias Agr, Casilla 747, Talca, ChileStudies were conducted to evaluate the use of several trap-lure combinations to improve the monitoring of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in apple, Mains domestica Bordk. The treatments involved the use of clear, orange, and white traps baited with one or more of the following attractants: the major sex pheromone component of the codling moth, (E, E)-8,10-dodecadien-1-ol (codlemone, PH); a primary volatile constituent of ripe pear, ethyl (E, Z)-2,4-decadienoate (pear ester, PE); and acetic acid (AA). The studies were conducted in an orchard treated with sex pheromone dispensers in Washington State (USA) and in four untreated orchards in the Maule Region (Chile). In Washington State, the PE+AA lures caught more females than the PE+PH lure in both the clear and orange traps. The clear traps caught more female moths than the orange traps when each trap was baited with the PE+PH lure. The two lures caught similar total numbers of moths across trap colors. The clear traps baited with PE+PH caught significantly more total moths than the orange traps baited with PE+AA. In Chile, the clear traps baited with PE+AA caught more females than the orange traps baited with PE+PH over both moth flights during two field seasons. The white traps baited with PH and the orange traps baited with PE+PH caught similar total numbers of moths in three of the four flight periods. The clear trap baited with PE+AA caught significantly fewer moths than the two treatments that included a PH lure in two of the four flight periods. These data suggest that the adoption of clear delta traps with PE-I-AA lures would allow growers to better track the seasonal population dynamics of female codling moths