Fracture surface energies of high explosives PETN and RDX

Journal of Materials Science -     

Metabolic responses of White Pekin ducks to ambient temperature

Metabolic responses of unrestrained White Pekin ducks, Anas platyrhynchos, were determined at ambient temperatures of -5 degrees, 1 degrees, 10 degrees, 20 degrees, and 30 degrees C. Temperatures from the pectoralis and the subcutaneous back were monitored. Unrestrained ducks exhibited two metabolic states, a high response (540 cc. O2/kg/hr. at 20 degrees C.) and a low response (427 cc. O2/kg./hr. at 20 degrees C). Pectoralis muscle temperature did not vary greatly over the range of ambient temperatures tested and was considered to be a good representative of body temperature.     

Improving breastfeeding support: a community health improvement project

BACKGROUND: Because of the brevity of the postpartum hospital stay, mothers and their newborns are discharged home before breastfeeding is well established. In 1992, feedback from patients who had given birth at Fletcher Allen Health Care (Burlington, VT) suggested a need for more consistent, expert, and timely assistance with breastfeeding in the hospital and better continuity of care during the first few weeks at home. QUALITY IMPROVEMENT TEAM: In 1993 a team developed objectives, analyzed the problem and possible solutions, and made eight recommendations on how the hospital could do more to promote breastfeeding. Implementation by team members and hospital staff included policy development, staff education, acquisition of funding, a visiting professorship, development of a lactation consultant coordinator and team, and patient surveys to evaluate the program. A late 1994 survey of 63 postpartum patients on their day of discharge indicated a high level of satisfaction with breastfeeding support in the hospital. CURRENT STATUS: Activities are being undertaken for lactation consultation coverage, further policy development, implementation of nurse competency validation, improved patient and family education materials, and continued evaluation of the breastfeeding support program through patient surveys. CONCLUSION: In the face of barriers such as the project's large scope, a paucity of internal team members, and a large number and variety of recommendations, some of the recommendations and follow-up plans have yet to be implemented. Yet the project has yielded improvements in care and provides a model of how hospitals can expand their traditional boundaries of care and quality improvement into community health issues.     

Preparation and analysis of some food fats and oils for fatty acid content by gas-liquid chromatography

The fatty acid compositions of some food fats and oils were determined by gas-liquid chromatography (GLC) before and after application of reagents and conditions of some extraction procedures. The extraction procedures studied had a nonsignificant effect on the fatty acid compositions. Procedures leading to methyl ester formation through a series of room temp reactions were selected over procedures requiring higher temp reactions, on the basis of yield of products, fatty acid compositions of food lipids of simple composition, or both. These procedures were then used to prepare some food fats and oils for analysis by GLC and the fatty acid compositions determined in this manner are presented. Food Composition Laboratory, ARS, USDA.     

Polarization dependent four-wave-mixing and two-photon coherence insolids

Polarization dependent degenerate-four-wave-mixing experiments on semiconductors (ZnSe, CdS) and dielectrics (NaCl, PbF₂) reveal the essential mechanisms of the bound-electronic χ⁽³⁾ . We show, for the first time, that the observed anomalous dispersion of the polarization dependent phase-conjugate reflectivity can be explained using a simple 3-band model. The near vanishing reflectivity in the two-photon coherence geometry is shown to be a consequence of the interference between transitions originating from heavyand light-hole valence bands. We also present measurements on the polarization dichroism of the nonlinear refractive index (n₂), in good agreement with this simple theory     

Furan and Methylfurans in Foods: An Update on Occurrence,Mitigation, and Risk Assessment

The acceptance of many foods is related to traditional cooking practices, which create taste and texture and are important to digestibility, preservation, and the reduction of foodborne illnesses. A wide range of compounds are formed during the cooking of foods, a number of these have been shown to lead to adverse effects in classical toxicological models and are known as food processing contaminants (FPC). It is essential that the presence and effects of such compounds alone and in combination within the diet are understood such that proportionate risk management measures can be developed, while taking a holistic view across the whole value chain. Furan and alkylfurans (principally 2‐ and 3‐methylfuran) are highly volatile FPC, which are formed in a wide range of foods at low amounts. The focus of research to‐date has been on those foods, which have been identified to be most consequential in terms of being sources of exposure, namely jarred and canned foods for infants and young children (meals and drinks) and coffee (roast and ground, soluble). This report presents (i) new industry data on the occurrence of furan and methylfurans in selected food categories following previous coffee studies, (ii) the most salient parameters that impact furan formation, and (iii) aspects of importance for the risk assessment.     

Rise of multi-authored papers in economics: Demise of the ‘lone star’ and why?

Scientometrics - This paper builds on previous work by reviewing the key literature relating to the rise in co-authorship in economics and by presenting further new evidence on several features of...     

A genetically encoded pore for the stochastic detection of a protein kinase

Stochastic sensing is an emerging approach for the detection of a wide variety of analytes at the level of individual molecules. Detection is accomplished by observing the modulation of the current that flows through a single protein pore that has been engineered to bind an analyte of interest. Previously, protein analytes have been detected by using pores to which ligands have been appended at specific sites by targeted chemical modification. Here, we report the first genetically encoded stochastic sensor element for detecting a protein. A protein kinase inhibitor peptide sequence was incorporated into the alpha-hemolysin polypeptide, which was used to form a heteroheptameric pore containing a single copy of the inhibitor sequence. With this pore, the successful detection of the catalytic subunit of protein kinase A was demonstrated. This development should greatly facilitate the detection of active kinase subunits by stochastic sensing and the rapid screening of kinase inhibitors by an approach that yields kinetic information.     

Hybrid pore formation by directed insertion of α-haemolysin into solid-state nanopores

Most experiments on nanopores have concentrated on the pore-forming protein α-haemolysin (αHL) and on artificial pores in solid-state membranes. While biological pores offer an atomically precise structure and the potential for genetic engineering, solid-state nanopores offer durability, size and shape control, and are also better suited for integration into wafer-scale devices. However, each system has significant limitations: αHL is difficult to integrate because it relies on delicate lipid bilayers for mechanical support, and the fabrication of solid-state nanopores with precise dimensions remains challenging. Here we show that these limitations may be overcome by inserting a single αHL pore into a solid-state nanopore. A double-stranded DNA attached to the protein pore is threaded into a solid-state nanopore by electrophoretic translocation. Protein insertion is observed in 30-40% of our attempts, and translocation of single-stranded DNA demonstrates that the hybrid nanopore remains functional. The hybrid structure offers a platform to create wafer-scale device arrays for genomic analysis, including sequencing.