Contribution of thermal noise to the line width of Josephson radiation from superconducting point contacts

Contribution of thermal noise to line width of Josephson radiation from superconducting point contact

Research and education in management of large- scale technical programs Semiannual progress report

Research and education in management of large scale technical programs - education and integration of interdisciplinary tea

Technology and management of large-scale programs Semiannual progress report

Technology and management of large scale program

\u3cem\u3eRhizobium japonicum\u3c/em\u3e Mutants Defective in Symbiotic Nitrogen Fixation

Rhizobium japonicum strains 3I1b110 and 61A76 were mutagenized to obtain 25 independently derived mutants that produced soybean nodules defective in nitrogen fixation, as assayed by acetylene reduction. The proteins of both the bacterial and the plant portions of the nodules were analyzed by two-dimensional polyacrylamide gel electrophoresis. All of the mutants had lower-than-normal levels of the nitrogenase components, and all but four contained a prominent bacteroid protein not observed in wild-type bacteroids. Experiments with bacteria grown ex planta suggested that this protein was derepressed by the absence of ammonia. Nitrogenase component II of one mutant was altered in isoelectric point. The soluble plant fraction of the nodules of seven mutants had very low levels of heme, yet the nodules of five of these seven mutants contained the polypeptide of leghemoglobin. Thus, the synthesis of the globin may not be coupled to the content of available heme in soybean nodules. The nodules of the other two of these seven mutants lacked not only leghemoglobin but most of the other normal plant and bacteroid proteins. Ultrastructural examination of nodules formed by these two mutants indicated normal ramification of infection threads but suggested a problem in subsequent survival of the bacteria and their release from the infection threads

Control of the finite size corrections in exact diagonalization studies

We study the possibility of controlling the finite size corrections in exact diagonalization studies quantitatively. We consider the one- and two dimensional Hubbard model. We show that the finite-size corrections can be be reduced systematically by a grand-canonical integration over boundary conditions. We find, in general, an improvement of one order of magnitude with respect to studies with periodic boundary conditions only. We present results for ground-state properties of the 2D Hubbard model and an evaluation of the specific heat for the 1D and 2D Hubbard model.Comment: Phys. Rev. B (Brief Report), in pres

Shooting Alone: The Pre-Attack Experiences and Behaviors of U.S. Solo Mass Murderers with Implications for Threat Assessments

This paper outlines the socio-demographic, developmental, antecedent attack, attack preparation and commission properties of 115 mass murderers between 1990 and 2014. The results indicate that mass murderer attacks are usually the culmination of a complex mix of personal, political and social drivers that crystalize at the same time to drive the individual down the path of violent action. We specifically focus upon areas related to prior criminal engagement, leakage and attack location familiarity. Whether the violence comes to fruition is usually a combination of the availability and vulnerability of suitable targets that suit the heady mix of personal and political grievances and the individual’s capability to engage in an attack from both a psychological and technical capability standpoint. Many individual cases share a mixture of unfortunate personal life circumstances coupled with an intensification of beliefs/grievances that later developed into the idea to engage in violence

Fe XVII X-ray Line Ratios for Accurate Astrophysical Plasma Diagnostics

New laboratory measurements using an Electron Beam Ion Trap (EBIT) and an x-ray microcalorimeter are presented for the n=3 to n=2 Fe XVII emission lines in the 15 {\AA} to 17 {\AA} range, along with new theoretical predictions for a variety of electron energy distributions. This work improves upon our earlier work on these lines by providing measurements at more electron impact energies (seven values from 846 to 1185 eV), performing an in situ determination of the x-ray window transmission, taking steps to minimize the ion impurity concentrations, correcting the electron energies for space charge shifts, and estimating the residual electron energy uncertainties. The results for the 3C/3D and 3s/3C line ratios are generally in agreement with the closest theory to within 10%, and in agreement with previous measurements from an independent group to within 20%. Better consistency between the two experimental groups is obtained at the lowest electron energies by using theory to interpolate, taking into account the significantly different electron energy distributions. Evidence for resonance collision effects in the spectra is discussed. Renormalized values for the absolute cross sections of the 3C and 3D lines are obtained by combining previously published results, and shown to be in agreement with the predictions of converged R-matrix theory. This work establishes consistency between results from independent laboratories and improves the reliability of these lines for astrophysical diagnostics. Factors that should be taken into account for accurate diagnostics are discussed, including electron energy distribution, polarization, absorption/scattering, and line blends.Comment: 29 pages, including 7 figure

‘They hear “Africa” and they think that there can’t be any good services’ – perceived context in cross-national learning: a qualitative study of the barriers to Reverse Innovation.

BACKGROUND: Country-of-origin of a product can negatively influence its rating, particularly if the product is from a low-income country. It follows that how non-traditional sources of innovation, such as low-income countries, are perceived is likely to be an important part of a diffusion process, particularly given the strong social and cognitive boundaries associated with the healthcare professions. METHODS: Between September and December 2014, we conducted eleven in-depth face-to-face or telephone interviews with key informants from innovation, health and social policy circles, experts in international comparative policy research and leaders in Reverse Innovation in the United States. Interviews were open-ended with guiding probes into the barriers and enablers to Reverse Innovation in the US context, specifically also to understand whether, in their experience translating or attempting to translate innovations from low-income contexts into the US, the source of the innovation matters in the adopter context. Interviews were recorded, transcribed and analyzed thematically using the process of constant comparison. RESULTS: Our findings show that innovations from low-income countries tend to be discounted early on because of prior assumptions about the potential for these contexts to offer solutions to healthcare problems in the US. Judgments are made about the similarity of low-income contexts with the US, even though this is based oftentimes on flimsy perceptions only. Mixing levels of analysis, local and national, leads to country-level stereotyping and missed opportunities to learn from low-income countries. CONCLUSIONS: Our research highlights that prior expectations, invoked by the Low-income country cue, are interfering with a transparent and objective learning process. There may be merit in adopting some techniques from the cognitive psychology and marketing literatures to understand better the relative importance of source in healthcare research and innovation diffusion. Counter-stereotyping techniques and decision-making tools may be useful to help decision-makers evaluate the generalizability of research findings objectively and transparently. We suggest that those interested in Reverse Innovation should reflect carefully on the value of disclosing the source of the innovation that is being proposed, if doing so is likely to invoke negative stereotypes

Similar crimes, similar behaviors? Comparing lone-actor terrorists and public mass murderers

This article adds to the growth in data-driven analyses seeking to compare samples of violent extremists with other violent populations of interest. While lone-actor terrorists and public mass murderers are frequently treated as distinct offender types, both engage (or attempt to engage) in largely public and highly publicized acts of violence and often use similar weapons. This article investigates the (dis)similarities between both offender types. We use a series of bivariate and multivariate statistical analyses to compare demographic, psychologic and behavioral variables across 71 lone-actor terrorists and 115 public mass murderers. The results show little distinction in sociodemographic profiles, but significant differences in (a) the degree to which they interact with co-ideologues (b) antecedent event behaviors and (c) the degree to which they leak information before the attack. Overall, our data inform the emerging idea that lone-actor terrorists and public mass shooters are not distinct offender types. There is more that unites them than divides them. Although the over-arching focus of our results are on the few variables that distinguish them, the vast majority (80%+), of the 180+ variables showed no significant difference. We discuss implications for threat assessment and management in the context of these results

A Device for Noninvasive Assessment of Vascular Impairment Risk in the Lower Extremity

The repeatability and resolution of the clinical gold standard of vascular assessment, the ankle-brachial index (ABI), was compared to that of a new device that dynamically assesses tissue perfusion during external loading utilizing laser Doppler flowmetry. Eight subjects of varying levels of vascular impairment were tested in successive weeks using two different sites on the subject\u27s posterior calf. These new measures included the perfusion decrease as well as the unloading delay during cyclic loading. Some new dynamic tissue perfusion measures demonstrated comparable levels of reproducibility with the ABI (e.g., 10%-20%). Only the unloading delay showed potentially enhanced resolution over ABI measures. The perfusion decrease showed little resolution, and the remaining parameters exhibited too great variability (25%-90%). The unloading delay associated with the reperfusion response during cyclic loading displayed the greatest combination of reproducibility and differentiation between subject groups of varying levels of vascular impairment. The preliminary results of this pilot study were also used to estimate sample sizes necessary to detect possible significant (