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M. Dixon et al., We use stacked spectra of the host galaxies of photometrically identified Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) to search for correlations between Hubble diagram residuals and the spectral properties of the host galaxies. Utilizing full spectrum fitting techniques on stacked spectra binned by Hubble residual, we find no evidence for trends between Hubble residuals and properties of the host galaxies that rely on spectral absorption features (, MD would like to acknowledge support through an Australian Government Research Training Program Scholarship. This research was supported by the Australian Research Council The Centre of Excellence for Dark Matter Particle Physics (CDM; project number CE200100008) and the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav; project number CE170100004). This project/publication was made possible through the support of a grant from the John Templeton Foundation. The authors gratefully acknowledge this grant ID 61807, Two Standard Models Meet. The opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of the John Templeton Foundation. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenössische Technische Hochschule (ETH) Zürich, Fermi National Accelerator Laboratory, the University of Illinois at Urbana-Champaign, the Institut de Ciències de l’Espai (IEEC/CSIC), the Institut de Física d’Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universität München and the associated Excellence Cluster Universe, the University of Michigan, NSF’s NOIRLab, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, Texas A&M University, and the OzDES Membership Consortium. Based in part on observations at Cerro Tololo Inter-American Observatory at NSF’s NOIRLab (NOIRLab Prop. ID 2012B-0001; PI: J. Frieman), which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. The DES data management system is supported by the National Science Foundation under Grant Numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MICINN under grants ESP2017-89838, PGC2018-094773, PGC2018-102021, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciência e Tecnologia (INCT) do e-Universo (CNPq grant 465376/2014-2). This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. Based on data acquired at the Anglo-Australian Telescope, under program A/2013B/012. We acknowledge the traditional custodians of the land on which the AAT stands, the Gamilaraay people, and pay our respects to elders past and present.

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiere, This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Monthly Notices of the Royal Astronomical Society 520.2 (2023): 2009-2023 is available online at: https://academic.oup.com/mnras/article-abstract/520/2/2009/6988199?redirectedFrom=fulltext#no-access-message, Reverberation mapping measurements have been used to constrain the relationship between the size of the broad-line region and luminosity of active galactic nuclei (AGN). This R-L relation is used to estimate single-epoch virial black hole masses, and has been proposed to use to standardize AGN to determine cosmological distances. We present reverberation measurements made with Hβ from the 6-yr Australian Dark Energy Survey (OzDES) Reverberation Mapping Program. We successfully recover reverberation lags for eight AGN at 0.12 < z < 0.71, probing higher redshifts than the bulk of Hβ measurements made to date. Our fit to the R-L relation has a slope of α = 0.41 ± 0.03 and an intrinsic scatter of σ = 0.23 ± 0.02 dex. The results from our multi-object spectroscopic survey are consistent with previous measurements made by dedicated source-by-source campaigns, and with the observed dependence on accretion rate. Future surveys, including LSST, TiDES, and SDSS-V, which will be revisiting some of our observed fields, will be able to build on the results of our first-generation multi-object reverberation mapping survey, The DES participants from Spanish institutions are partially supported by MICINN under grants ESP2017-89838, PGC2018-094773, PGC2018-102021, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these re-sults has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciên-cia e Tecnologia (INCT) do e-Universo (CNPq grant 465376/2014-2). This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. De-partment of Energy, Office of Science, Office of High Energy Physics.

Tucker et al., On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star–black hole merger (NSBH), the first ever identified. An extensive search for an optical counterpart of this event, designated GW190814, was undertaken using the Dark Energy Camera on the 4 m Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory. Target of Opportunity interrupts were issued on eight separate nights to observe 11 candidates using the 4.1 m Southern Astrophysical Research (SOAR) telescope's Goodman High Throughput Spectrograph in order to assess whether any of these transients was likely to be an optical counterpart of the possible NSBH merger. Here, we describe the process of observing with SOAR, the analysis of our spectra, our spectroscopic typing methodology, and our resultant conclusion that none of the candidates corresponded to the gravitational wave merger event but were all instead other transients. Finally, we describe the lessons learned from this effort. Application of these lessons will be critical for a successful community spectroscopic follow-up program for LVC observing run 4 (O4) and beyond., Funding for the DES Projects has been provided by the DOE and NSF(USA), MEC/MICINN/MINECO (Spain), STFC (UK), HEFCE(UK). NCSA (UIUC), KICP (U. Chicago), CCAPP (Ohio State), MIFPA (Texas A&M), CNPQ, FAPERJ, FINEP (Brazil), DFG (Germany) and the Collaborating Institutions in the Dark Energy Survey. The DES Data Management System is supported by the NSF under grant Nos. AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015-71825, ESP2015-88861, FPA2015-68048, and Centro de Excelencia SEV-2016-0588, SEV-2016-0597 and MDM-2015-0509. Research leading to these results has received funding from the ERC under the EU's 7th Framework Programme including grants ERC 240672, 291329 and 306478. I.A. is a CIFAR Azrieli Global Scholar in the Gravity and the Extreme Universe Program and acknowledges support from that program, from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation program (grant agreement number 852097), from the Israel Science Foundation (grant number 2752/19), from the United States–Israel Binational Science Foundation (BSF), and from the Israeli Council for Higher Education Alon Fellowship.

We present multi-wavelength spectral and temporal variability analysis of PKS 0027-426 using optical griz observations from DES (Dark Energy Survey) between 2013-2018 and VOILETTE (VEILS Optical Light curves of Extragalactic TransienT Events) between 2018-2019 and near infrared (NIR) JKs observations from VEILS (VISTAExtragalactic Infrared Legacy Survey) between 2017-2019. Multiple methods of cross-correlation of each combination of light curve provides measurements of possible lags between optical-optical, optical-NIR, and NIR-NIR emission, for each observation season and for the entire observational period. Inter-band time lag measurements consistently suggest either simultaneous emission or delays between emission regions on timescales smaller than the cadences of observations. The colour-magnitude relation between each combination of filters was also studied to determine the spectral behaviour of PKS 0027-426. Our results demonstrate complex colour behaviour that changes between bluer when brighter (BWB), stable when brighter (SWB) and redder when brighter (RWB) trends over different timescales and using different combinations of optical filters. Additional analysis of the optical spectra is performed to provide further understanding of this complex spectral behaviour., Accepted for publication in MNRAS. 33 pages, 28 figures, 11 tables

Preferences for pink and blue were tested in children aged 4–11 years in three small-scale societies: Shipibo villages in the Peruvian Amazon, kastom villages in the highlands of Tanna Island, Vanuatu, and BaYaka foragers in the northern Republic of Congo; and compared to children from an Australian global city (total N = 232). No sex differences were found in preference for pink in any of the three societies not influenced by global culture (ds − 0.31–0.23), in contrast to a female preference for pink in the global city (d = 1.24). Results suggest that the pairing of female and pink is a cultural phenomenon and is not driven by an essential preference for pink in girls.

Funder: Gates Cambridge Trust; doi: http://dx.doi.org/10.13039/501100005370, It is generally recognized that there are gender-related differences in children’s toy preferences. However, the magnitude of these differences has not been firmly established. Furthermore, not all studies of gender-related toy preferences find significant gender differences. These inconsistent findings could result from using different toys or methods to measure toy preferences or from studying children of different ages. Our systematic review and meta-analysis combined 113 effect sizes from 75 studies to estimate the magnitude of gender-related differences in toy preferences. We also assessed the impact of using different toys or methods to assess these differences, as well as the effect of age on gender-related toy preferences. Boys preferred boy-related toys more than girls did, and girls preferred girl-related toys more than boys did. These differences were large (d ≥ 1.60). Girls also preferred toys that researchers classified as neutral more than boys did (d = 0.29). Preferences for gender-typical over gender-atypical toys were also large and significant (d ≥ 1.20), and girls and boys showed gender-related differences of similar magnitude. When only dolls and vehicles were considered, within-sex differences were even larger and of comparable size for boys and girls. Researchers sometimes misclassified toys, perhaps contributing to an apparent gender difference in preference for neutral toys. Forced choice methods produced larger gender-related differences than other methods, and gender-related differences increased with age.

The analysis of current and future cosmological surveys of Type Ia supernovae (SNe Ia) at high redshift depends on the accurate photometric classification of the SN events detected. Generating realistic simulations of photometric SN surveys constitutes an essential step for training and testing photometric classification algorithms, and for correcting biases introduced by selection effects and contamination arising from core-collapse SNe in the photometric SN Ia samples. We use published SN time-series spectrophotometric templates, rates, luminosity functions, and empirical relationships between SNe and their host galaxies to construct a framework for simulating photometric SN surveys. We present this framework in the context of the Dark Energy Survey (DES) 5-yr photometric SN sample, comparing our simulations of DES with the observed DES transient populations. We demonstrate excellent agreement in many distributions, including Hubble residuals, between our simulations and data. We estimate the core collapse fraction expected in the DES SN sample after selection requirements are applied and before photometric classification. After testing different modelling choices and astrophysical assumptions underlying our simulation, we find that the predicted contamination varies from 7.2 to 11.7 per cent, with an average of 8.8 per cent and an r.m.s. of 1.1 per cent. Our simulations are the first to reproduce the observed photometric SN and host galaxy properties in high-redshift surveys without fine-tuning the input parameters. The simulation methods presented here will be a critical component of the cosmology analysis of the DES photometric SN Ia sample: correcting for biases arising from contamination, and evaluating the associated systematic uncertainty.

We describe the creation, content, and validation of the Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support of upcoming cosmological analyses. The Y1A1 GOLD data set is assembled from multiple epochs of DES imaging and consists of calibrated photometric zero-points, object catalogs, and ancillary data products—e.g., maps of survey depth and observing conditions, star–galaxy classification, and photometric redshift estimates—that are necessary for accurate cosmological analyses. The Y1A1 GOLD wide-area object catalog consists of $\sim 137$ million objects detected in co-added images covering $\sim 1800\,{\deg }^{2}$ in the DES grizY filters. The 10σ limiting magnitude for galaxies is $g=23.4$, $r=23.2$, $i=22.5$, $z=21.8$, and $Y=20.1$. Photometric calibration of Y1A1 GOLD was performed by combining nightly zero-point solutions with stellar locus regression, and the absolute calibration accuracy is better than 2% over the survey area. DES Y1A1 GOLD is the largest photometric data set at the achieved depth to date, enabling precise measurements of cosmic acceleration at z lesssim 1., Multiple funders including STFC listed on paper.

Using proton-transfer reactions in a Fourier transform ion cyclotron resonance mass spectrometer and correlated molecular orbital theory at the G3(MP2) level, gas-phase acidities (GAs) and the associated structures for amides corresponding to the common amino acids have been determined for the first time. These values are important because amino acid amides are models for residues in peptides and proteins. For compounds whose most acidic site is the C-terminal amide nitrogen, two ions populations were observed experimentally with GAs that differ by 4-7 kcal/mol. The lower energy, more acidic structure accounts for the majority of the ions formed by electrospray ionization. G3(MP2) calculations predict that the lowest energy anionic conformer has a cis-like orientation of the [-C(═O)NH](-) group whereas the higher energy, less acidic conformer has a trans-like orientation of this group. These two distinct conformers were predicted for compounds with aliphatic, amide, basic, hydroxyl, and thioether side chains. For the most acidic amino acid amides (tyrosine, cysteine, tryptophan, histidine, aspartic acid, and glutamic acid amides) only one conformer was observed experimentally, and its experimental GA correlates with the theoretical GA related to side chain deprotonation.

Sixteen meat and bone meal (MBM) samples were obtained and selected from various company plants to provide a wide range in pepsin nitrogen digestibility values. Pepsin digestibility was determined using either 0.02 or 0.002% pepsin. Amino acid (AA) digestibility of the 16 MBM samples was then determined using a precision-fed cecectomized rooster assay. The 0.02% pepsin digestibility values were numerically higher than the 0.002% pepsin values. The values varied from 77 to 93% for 0.02% pepsin and from 67 to 91% for 0.002% pepsin. The rooster AA digestibility results showed a wide range of values among MBM samples mostly due to the 4 samples having lowest and highest AA digestibility. A precision-fed broiler chick ileal AA digestibility assay confirmed that there were large differences in AA digestibility among the MBM samples having the lowest and highest rooster digestibility values. Correlation analyses between pepsin and AA digestibility values showed that the correlation values (r) were highly significant (P0.0001) for all AA when all 16 MBM samples were included in the analysis. However, when the MBM samples with the 2 lowest and the 2 highest rooster digestibility values were not included in the correlation analyses, the correlation coefficient values (r) were generally very low and not significant (P0.05). The results indicated that the pepsin nitrogen digestibility assay is only useful for detecting large differences in AA digestibility among MBM. There also was no advantage for using 0.02 versus 0.002% pepsin.

The quality of analytical measurements can be influenced by the matrix of the sample of interest. The knowledge of the sample matrix allows for appropriate sample preparation, instrumental parameters, and quantification methods in an effort to achieve accurate results. Matrix matching can be difficult when sampling across various water sources with the possible introduction of unknown endogenous contaminants due to various degrees of land use, urbanization, and energy exploration, likely playing a factor. The degree of matrix effects in inductively coupled plasma–optical emission spectroscopy for nineteen metals from twenty groundwater samples across North Texas was assessed using a standard addition method. Matrix effects were characterized in collected groundwater samples (a) with no pretreatment, (b) after reversed-phase solid-phase extraction of possible organic contaminants, and (c) for a matrix of organic material retained on the reversed-phase sorbent. It was found that without any extraction treatment, only 54 % of all measurements experienced no matrix effect. After extracting unknown organic sample constituents, an increase to 74 % of measurements showing no matrix effect was recorded. Reconstituting the extracted organic sample matrix found this fraction to be a significant source of the deviated results with only 13 % experiencing no matrix effect. Results for the metals investigated are also discussed, along with correlations to water quality parameters such as turbidity, total dissolved solids, and salinity.

Deliberate practice is essential for skill acquisition and expertise and may be a direct consequence of episodic foresight. However, little is known about how deliberate practice develops in children. We present two experiments testing children's ability to selectively practise a behaviour that was going to be useful in future and to reason about the role of practice in skill formation. Five-year-olds demonstrated an explicit understanding of deliberate practice both in selectively choosing to practise a future-relevant skill and in predicting skill change in others based on their practice. Four-year-olds showed some capacities, but failed to demonstrate consistent understanding of the relationship between practice and skill improvement. Children's understanding of this relationship was significantly related to their understanding of how information leads to knowledge, suggesting that both may draw on similar cognitive developmental changes.

This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2013. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with environmental management, sustainability efforts, environmental corrective actions, and habitat restoration. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, Argonne, and other) and are compared with applicable standards intended to protect human health and the environment. A U.S. Department of Energy (DOE) dose calculation methodology, based on International Commission on Radiological Protection (ICRP) recommendations and the U.S. Environmental Protection Agency’s (EPA) CAP-88 Version 3 computer code, wasmore » used in preparing this report.« less

Well-recovery networks coupled to immobilized microbe bioreactors (IMBRs) were installed at a 172-acre former wood preserving facility for the bioremediation of organic wood preservatives present in site groundwater. Free-phase creosote from the hardpan and soluble preservative fractions contained in subsurface groundwater were pumped separately to different holding tanks. Trace creosote fractions contained in the subsurface groundwater were further gravity separated in the holding tank. Immobilized microbial isolates evaluated in earlier laboratory and field pilot tests were established into two 40, 000-liter bioreactors for the biodegradation of all targeted consitituents. Microbial growth, dissolved oxygen, pH, nutrients, flow rate, and temperature were monitored in this in situ/ex situ bioremediation system. The process was used to remove the polycyclic aromatic hydrocarbon (PAH) and phenolic components of creosote and pentachlorophenol from contaminated groundwater. Data generated during the past 2 1/2 years indicate that 26 target compounds consistently are reduced to levels acceptable for discharge. Currently operating in Baldwin, Florida, this full-scale prototype is remediating the former wood preserving facility and is being used as a model system for the design and construction of new bioreactor systems needed at similar industrial sites in the United States and abroad.

This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2008. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, fallout, Argonne, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's CAP-88 Version 3 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

This report discusses the status and the accomplishments of the environmental protection program at Argonne National Laboratory for calendar year 2007. The status of Argonne environmental protection activities with respect to compliance with the various laws and regulations is discussed, along with the progress of environmental corrective actions and restoration projects. To evaluate the effects of Argonne operations on the environment, samples of environmental media collected on the site, at the site boundary, and off the Argonne site were analyzed and compared with applicable guidelines and standards. A variety of radionuclides were measured in air, surface water, on-site groundwater, and bottom sediment samples. In addition, chemical constituents in surface water, groundwater, and Argonne effluent water were analyzed. External penetrating radiation doses were measured, and the potential for radiation exposure to off-site population groups was estimated. Results are interpreted in terms of the origin of the radioactive and chemical substances (i.e., natural, fallout, Argonne, and other) and are compared with applicable environmental quality standards. A U.S. Department of Energy dose calculation methodology, based on International Commission on Radiological Protection recommendations and the U.S. Environmental Protection Agency's CAP-88 Version 3 (Clean Air Act Assessment Package-1988) computer code, was used in preparing this report.

Turbomachine‐based Brayton (turbo‐Brayton) cryocoolers are an ideal option for long‐duration space missions. Key attributes inherent to the technology are high reliability, extremely low vibration emittance, and flexible packaging and integration with instruments and spacecraft systems. The first space implementation of the technology was the NICMOS Cryocooler, which is a single‐stage unit that was installed on the Hubble Space Telescope in March 2002. This cryocooler provides 7 W of cooling at 70 K and has been operating for 3.3 years (July 2005) without degradation in performance. New developments at Creare are focused on two‐stage configurations with load temperatures as low as 6 K. The lower temperatures and loads have required advances in component technologies to meet aggressive targets for cryocooler mass, size and performance. The development of the electronics, compressors and intermediate turboalternator for a 6–10 K cryocooler are complete. This paper summarizes our accomplishments on the completed components, and reviews our progress towards the development of the remaining critical components, a lightweight recuperator and a high performance low temperature turboalternator.

The Air Force Research Laboratory (AFRL) Cryogenic Technology Research Facility (CTRF) is characterizing the performance of the Northrop Grumman Space Technology (NGST), previously TRW, 150 K mini pulse tube (MPT) cryocooler. This cooler was developed under the AFRL 150 K Protoflight Spacecraft Cryocooler (PSC) Program supported by the Missile Defense Agency (MDA), then Ballistic Missile Defense Organization, (BMDO). Although this cooler has a smaller heat load capacity than other long-life space cryogenic coolers, it has been successfully used in a variety of scientific and military space applications providing cooling of focal planes, optics, and sensors for instruments such as SABER, CX, Hyperion, and the projected STSS Flight Demonstration System (FDS).

As the life and reliability capabilities of cryocoolers have improved there has been a corresponding evolution of user requirements. Tactical applications routinely require operation in excess of 10,000 hours; space‐borne applications require operational life of >10 years. Demonstration of these long lifetimes provides a substantial challenge. Previous treatises have discussed means of addressing specific aspects of reliability via accelerated life testing. This paper provides a review of documented accelerated test methods as well as test methods that may be considered for non‐wear related failures. A review of common life‐limiting features of cryocoolers is provided, including: seal wear, flexure fatigue, gaseous and particulate contamination, fretting failures at interfaces between non‐moving/moving components and random failures. A recommendation for accelerated assessment of the lifetime and reliability related to each limitation is presented. The result is a compilation of test methodologies that may be tailored to users’ and designers’ needs. This approach offers the potential of providing a realistic assessment of operational life without incurring the cost and schedule associated with operating multiple cryocoolers to failure over a multi‐year period.

This paper presents results from characterization studies performed on the Northrop Grumman Space Technology, formerly TRW, 95 K High Efficiency Cryocooler at the Air Force Research Laboratory (AFRL) Cryogenic Technology Research Facility. This pulse tube cryocooler unit is capable of lifting 10 W heat loads at 95 K, and has demonstrated the highest efficiency performance at this temperature range for space cryocoolers characterized at AFRL. Physical characteristics of the test setup for the cooler are described in the paper. Results are presented for the cryocooler over a wide range of operating parameters and environmental conditions. Effects of varying heat rejection temperature, compressor drive input, and heat loads on the input power and cold end temperatures are examined as well as the cold end temperature stability. In addition, the effect of orientation on the cryocooler’s performance is presented. The cooler has entered life‐test mode with accumulation of over 5000 of run‐time hours.

Future Department of Defense missions will require efficient, low mass, reliable mechanical cryocoolers. Loads of 2 W to 8 W at 35 K are anticipated, combined with higher loads at higher temperatures for optical benches and shielding. A single, multistage cryocooler that can supply refrigeration to several loads at distributed locations without significant penalties in performance has the potential for dramatic reductions in overall mass, system complexity, and input power when compared to multiple single‐point coolers. In early 2002, a single‐stage turbo‐Brayton cryocooler was installed on the Hubble Space Telescope to cool the NICMOS instrument. The NICMOS Cryogenic Cooler (NCC) returned the instrument to operation within one month of installation and has maintained the instrument at optimum temperature since that time. The NCC provides 7 W of cooling at 70 K. Recently completed efforts have demonstrated a single‐stage cryocooler using comparable technology that provides 3 W to 4 W of refrigeration at a...

To investigate pituitary-adrenal function in acute uncomplicated falciparum malaria, we performed an overnight dexamethasone suppression test in 13 Vietnamese adults with acute malaria and 6 healthy controls. After blood samples were taken for serum cortisol and plasma ACTH at 23.00 hours on the admission day, 1 mg dexamethasone was given and further samples were taken at 08.00, 16.00 and 23.00 hours the next day. The patients received conventional antimalarial and supportive treatment. Baseline plasma ACTH concentrations in the patients [3.9 (0.2-41.2) pmol/l] and controls [3.4 (1.1-4.3) pmol/l] were similar (p=0.51), and exhibited a similar fall after dexamethasone to 0.6 (0.2-2.5) and 0.9 (0.7-1.6) pmol/l at 08.00 hours respectively (p0.03 vs 23.00 hour values). Serum cortisol levels before dexamethasone were higher in the patients than in the controls [456 (102-821) vs 145 (64-183) nmol/l respectively; p=0.007] and the overnight fall was less in the patients [208 (26-340) and 23 (15-46) nmol/l at 08.00 hours respectively; p0.001 vs 23.00 hour values and between groups]. Between 08.00 and 23.00 hours, plasma ACTH and serum cortisol remained suppressed in the controls. In the patients, the serum cortisol continued to fall progressively towards control values. These data suggest that there is a raised set point for cortisol inhibition of ACTH secretion but normal corticotrophin responsiveness to dexamethasone in uncomplicated malaria. A raised serum cortisol after dexamethasone in the patients might reflect the combination of a prolonged cortisol half-life and the stimulatory effects of cytokines on the adrenal cortex, with a consequent protective effect against complications such as hypoglycemia.