Instrument design for an inertial confinement fusion ion temperature imager.

A mix of contaminant mass is a known, performance-limiting factor for laser-driven inertial confinement fusion (ICF). It has also recently been shown that the contaminant mass is not necessarily in thermal equilibrium with the deuterium-tritium plasma [B. M. Haines et al., Nat. Commun. 11, 544 (2020)]. Contaminant mass temperature is one of the dominant uncertainties in contaminant mass estimates. The MixIT diagnostic is a new and potentially transformative diagnostic, capable of spatially resolving ion temperature. The approach combines principles of neutron time-of-flight and neutron imaging diagnostics. The information from the MixIT diagnostic can be used to optimize ICF target and laser drive designs as well as provide key constraints on ICF radiation-hydrodynamic simulations that are critical to contaminant mass estimates. This work details the design and optimization of the major components of the MixIT diagnostic: the neutron aperture, the neutron detector (scintillator), and the recording system.

Design of multi neutron-to-gamma converter array for measuring time resolved ion temperature of inertial confinement fusion implosions.

The ion temperature varying during inertial confinement fusion implosions changes the amount of Doppler broadening of the fusion products, creating subtle changes in the fusion neutron pulse as it moves away from the implosion. A diagnostic design to try to measure these subtle effects is introduced-leveraging the fast time resolution of gas Cherenkov detectors along with a multi-puck array that converts a small amount of the neutron pulse into gamma-rays, one can measure multiple snapshots of the neutron pulse at intermediate distances. Precise measurements of the propagating neutron pulse, specifically the variation in the peak location and the skew, could be used to infer time-evolved ion temperature evolved during peak compression.

Monitoring SARS-CoV-2 decontamination by dry heat and ultraviolet treatment with a swine coronavirus as a surrogate.

The critical need for reliable methods to validate decontamination protocols for personal protective equipment (PPE) for re-use during the SARS-CoV-2 pandemic is limited by the need for specialized containment facilities to handle the virus. Hence, we have herein validated the use of a swine coronavirus as a surrogate, and tested the effectiveness of dry heat and ultraviolet (UV) rays for PPE decontamination. Exposure of experimentally contaminated N95 masks and hospital gowns to 60°C for 20 min, and UVC at 1800 mJ/cm2 resulted in a 4-log reduction and inactivation of the surrogate virus. This study provides a novel alternative to validate PPE reprocessing methods.

Trends in analytical scale separations.

Although gas chromatography has been called a mature technology, advances are still being made in the development of faster columns as well as detectors which yield more information on solutes. In liquid chromatography short columns packed with 3-micrometer particles are already popular for fast analyses, while long narrow-bore columns are being developed for high-resolution separations. An increasing range of detection modes is enhancing the problem-solving capabilities of liquid chromatography. Electrophoresis continues to be of central importance to molecular biology. Computer-aided analysis and display of electropherogram patterns is helping researchers to better comprehend the wealth of data from two-dimensional electrophoresis. A new mode of two-dimensional electrophoresis is permitting separation of whole chromosomes containing as many as 3 million base pairs.

Microcolumn separations and the analysis of single cells.

Capillary zone electrophoresis and open tubular liquid chromatography are two examples of an emerging area of analytical instrumentation known as microcolumn separations. The high resolution and small sample requirements of these methods make them suitable for the quantitative, multicomponent chemical analysis of single cells. Appropriate instrumentation for the analysis of nanoliter and subnanoliter samples is discussed. Data from the analysis of individual neurons are presented, including amino acid and neurotransmitter content.

Chemical Scent Constituents in the Urine of the Red Fox (Vulpes vulpes L.) During the Winter Season.

Four volatile chemical compounds have been identified as apparently unique constituents in urines of red foxes (both sexes) during the winter season when mating occurs. Quinaldine was found only in male fox urine. Several other compounds identified are found in other species also. Some or all of these compounds may function in olfactory communication in the red fox.

Body mass and individual fitness in female ungulates: bigger is not always better.

In female vertebrates, differences in fitness often correspond to differences in phenotypic quality, suggesting that larger females have greater fitness. Variation in individual fitness can result from variation in life span and/or variation in yearly reproductive success, but no study has yet assessed the relationships between the components of fitness and phenotypic quality while controlling for life span. We tried to fill this gap using data from long-term monitoring (23 years) of marked roe deer and bighorn sheep, two ungulates with very different life histories. In both species, we found a strong positive relationship between an adult female's mass and her probability of reaching old age: over the long term, bigger is indeed better for ungulate females. On the other hand, we found no evidence in either species that heavier females had higher fitness when differences in life span were accounted for: over the short term, bigger is not necessarily better. Our results indicate that, while broad differences in phenotypic quality affect individual fitness, when differences in life span are accounted for phenotypic quality has no residual effect on fitness. Therefore, within a given range of phenotypic quality, bigger is not always better, for reasons which may differ between species.

Age-dependent sexual selection in bighorn rams.

Although mating systems and sexual selection have been intensively studied in ungulate model systems, very few studies have combined genetic paternity analysis with individual phenotypic data over several breeding seasons. We used microsatellite paternity analysis to determine the parentage of 83 bighorn sheep (Ovis canadensis) born between 1995 and 2000 at Ram Mountain, Alberta, Canada. We could assign the paternity of 64 lambs at a high level of statistical confidence (95%). Within each season, the most successful ram sired an average of 35.5% of the lambs with assigned paternity, and a single ram sired 26.1% of all lambs over the six mating seasons. Although a few large-horned, mature (age 8+ years) rams had very high reproductive success, younger rams sired ca. 50% of the lambs. Mixed-effects models indicated that mating success increases as a nonlinear function of age, with horn length increasingly positive in correlation with mating success in older rams. These results indicate that young or small rams possibly achieve mating success through alternative mating tactics that are less dependent on body and weapon size, such as coursing and blocking. Sexual selection is therefore likely to have age-dependent effects on traits such as agility, body and horn size.

Continuous flow fast atom bombardment with packed microcolumns: A comparison of precolumn versus coaxial matrix delivery.

The effect of adding glycerol to the mobile phase on the chromatographic separation of peptides has been investigated using a continuous flow fast atom bombardment (CFFAB) interface coupled with commercial packed microcolumns (25 cm × 320 µm.i.d.). In a comparative study using a UV detector, it was found that chromatographic peak broadening progressively increased with increasing percentage of glycerol in the mobile phase. In the liquid chromatographic FAB mass spectrometric analysis, this effect is compounded by the dynamic mixing of the column effluent on the probe. Improvements of 25-155% in the overall separation efficiencies were obtained by introducing the matrix independently to the probe tip via a coaxial arrangement. Application of this coaxial CFFAB is demonstrated by the analysis of peptide mixtures and tryptic digests.

Optimization of capillary zone electrophoresis/electrospray ionization parameters for the mass spectrometry and tandem mass spectrometry analysis of peptides.

The solution chemistry conditions necessary for optimum analysis of peptides by capillary zone electrophoresis (CZE)/electrospray ionization mass spectrometry and CZE electrospray ionization tandem mass spectrometry have been studied. To maximize the signal-to-noise ratio of the spectra it was found necessary to use acidic CZE buffers of low ionic strength. This not only increases the total ion current, but it also serves to fully protonate the peptides, minimizing the distribution of ion current across the ensemble of possible charge states.The use of acidic buffers protonates the peptides, which is advantageous for mass spectrometry and tandem mass spectrometry analysis, but is problematic with CZE when bare fused silica CZE columns are used. These conditions produce positively charged peptides, and negatively charged silanol moieties on the column wall, inducing adsorption of the positively charged peptides, thus causing zone broadening and a loss in separation efficiency. This problem was circumvented by the preparation of chemically modified CZE columns, which, when used with acidic CZE buffers, will have a positively charged inner column wall. The electrostatic repulsion between the positively charged peptides and the positively charged CZE column wall minimizes adsorption problems and facilitates high efficiency separations. Full-scan mass spectra were acquired from injections of as little as 160 fmols of test peptides, with CZE separation efficiencies of up to 250,000 theoretical plates.

Aldrin and dieldrin: a review of research on their production, environmental deposition and fate, bioaccumulation, toxicology, and epidemiology in the United States.

In the last decade four international agreements have focused on a group of chemical substances known as persistent organic pollutants (POPs). Global agreement on the reduction and eventual elimination of these substances by banning their production and trade is a long-term goal. Negotiations for these agreements have focused on the need to correlate data from scientists working on soil and water sampling and air pollution monitoring. Toxicologists and epidemiologists have focused on wildlife and human health effects and understanding patterns of disease requires better access to these data. In the last 20 years, substantial databases have been created and now are becoming available on the Internet. This review is a detailed examination of 2 of the 12 POPs, aldrin and dieldrin, and how scientific groups identify and measure their effects. It draws on research findings from a variety of environmental monitoring networks in the United States. An overview of the ecologic and health effects of aldrin and dieldrin provides examples of how to streamline some of the programs and improve access to mutually useful scientific data. The research groups are located in many government departments, universities, and private organizations. Identifying databases can provide an "information accelerator" useful to a larger audience and can help build better plant and animal research models across scientific fields.

Bacteremia associated with operative decompression of a small bowel obstruction.

BACKGROUND: Intraoperative decompression of the small bowel has been advocated as a method of aiding recovery of both the patient and the intestine. However, the methods proposed (retrograde stripping or enterotomy) require vigorous handling of bacteria-laden small bowel, possibly giving rise to a bacteremia. STUDY DESIGN: A small bowel obstruction was created in 31 rats by means of a ligature. Twenty-four hours later, the obstruction was relieved, and the rats were divided into three groups: relief of obstruction alone, relief with retrograde stripping, and relief with enterotomy plus suction. Blood cultures were taken before and after manipulation of the bowel. RESULTS: In blood cultures taken before and after manipulation there was a significant increase of Escherichia coli bacteremia in the two manipulation groups compared with the relief of obstruction only group. CONCLUSIONS: Bacteremia may be an effect of operative decompression of obstructed bowel, which at times outweighs its supposed benefits.

A hybrid of exponential and gaussian functions as a simple model of asymmetric chromatographic peaks.

A hybrid of exponential and Gaussian functions is developed as a model of asymmetric peak profiles. This exponential-Gaussian hybrid function (EGH) is mathematically simple, numerically stable, and its parameters are readily determined by making graphical measurements and applying simple equations. Furthermore, the statistical moments of the EGH function can be accurately approximated (within+/-0.15% error) at any level of asymmetry using formulae that are easily programmed into a computer. These features of the EGH make it very easy to implement by most chromatographers. The EGH serves as a useful alternative to the exponentially modified Gaussian (EMG) for modeling slightly asymmetric peaks since the two models produce nearly the same profile at relatively low asymmetries. The EGH also serves as an addition to the extensive list of alternative models that are sometimes better than the EMG at describing highly asymmetric peaks. A comparison between EMG and EGH curves at various asymmetries is made by analysis of toluene, phenylalanine, and pyridine on a reversed-phase liquid chromatographic system.

Spatial and temporal progressions of spatial statistical moments in linear chromatography.

Generalizations of existing models of chromatography allow the spatial and temporal progressions of all spatial statistical moments in linear chromatography to be given as the solution to a set of ordinary differential equations. Basic strategies of simplifying these equations are described.

Work activities before and after implementation of an automated dispensing system.

The impact of an automated dispensing system (ADS) on medication-related work activities by nurses and pharmacists was studied. A point-of-care ADS (Baxter Sure-Med) was installed on two nursing units (the surgical intensive care unit [SICU] and a medicine unit [4NMU]) of a 400-bed university hospital as part of a pilot project. A self-reported work-sampling study was used to collect observations of medication-related work activities by nurses, health unit coordinators (nursing support staff), and pharmacists for a seven-day period before ADS implementation and a seven-day period after implementation. There were 7797 observations of nurse work activities, 1408 observations of health unit coordinator work activities, and 4236 observations of pharmacist work activities. The percentage of nurse work activities that were medication related decreased from 20.7% before ADS implementation to 18.4% afterward on 4NMU and increased slightly from 10.8% to 11.0% on the SICU. Medication-related health unit coordinator work activities increased from 17.5% to 25.3% of total activities on 4NMU and decreased from 16.6% to 10.7% on the SICU. None of these changes was significant. For decentralized pharmacists supporting 4NMU, the percentage of work activities classified as clinical increased significantly from 36.5% to 49.1%. For decentralized pharmacists supporting the SICU, clinical activities increased from 27.9% to 35.1%. There were no significant changes on either unit in pharmacist activities classified as technical. An overall measure of the efficiency with which pharmacists used their time for patient care-related activities increased. A point-of-care ADS did not affect the proportion of time spent by nurses on medication-related activities and seemed to give pharmacists more time for clinical work.

New techniques for liquid chromatography in open-tubular columns.

Methods for sample introduction, capillary column fabrication, and on-column detection are discussed. A new cross-linked polymer stationary phase coating (based on similar coatings for capillary gas chromatography) is described. Results of separations of urinary components using 16-mum open-tubular columns and electrochemical detection and laser-induced fluorescence detection are shown.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. (Nematoda: Filarioidea) from Colombian capybaras.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. is described from specimens recovered from skeletal muscle fascia of the capybara, Hydrochoerus hydrochacris, from several localities in Colombia, South America. The microfilaria, which is found in the skin of the host, is also described for the first time. The monotypic species of the subgenus Alafilaria can be distinguished from existing Dipetalonema subgenera and all filariae known to us, on the basis of numerous preanal caudal papillae in males, small size of petals on the caudal extremity of each sex, and low, bluntly-rounded lateral alae in the cuticle of adult worms of both sexes. Unusual and distinctive features of the microfilaria include conspicuous lateral cuticular alae and a caudal extremity devoid of nuclei.

Field immobilization of bighorn sheep with xylazine hydrochloride and antagonism with idazoxan.

Xylazine hydrochloride was used to immobilize 124 Rocky Mountain bighorn sheep (Ovis canadensis canadensis) between 1983 and 1988. Doses of xylazine for free-ranging lambs ranged from 70 to 130 mg with amounts increasing with lamb age. Average doses for 11 free-ranging adult males and 21 adult females darted from the ground were (means +/- SE) 363 +/- 16 and 251 +/- 7 mg, respectively. Adult females captured in "Stevenson's " box traps (n = 7) could be immobilized with significantly (P less than 0.001) less xylazine (93 +/- 9 mg) than free-ranging females but had similar induction times. Long recovery times associated with xylazine immobilization were eliminated with the intravenous administration of idazoxan (RX 781094) at an approximate dosage of 0.1 mg/kg. Eighteen sheep given idazoxan appeared fully recovered within 3 min of injection (means +/- SE = 1.2 +/- 0.2 min). Four mortalities (three lambs, one yearling male) (3% of total) occurred before idazoxan was available for trial.