Bulletin No. 238 - Lamb-Fattening Experiments in Utah

This bulletin includes the results of Station Project 99-Fattening Lambs in Winter Drylot-which was begun at Monroe on November 15, 1928, and at Delta on November 13, 1929. The experiment was conducted for a period of four years at Monroe and for one year at Delta. Messers Alma and Milton Magelby of Monroe were closely associated with the Monroe experiment, furnishing the yards and the lambs as well as the feed used; the Monroe Lamb-feeders Association also cooperated in conducting this experiment. During the period that the Delta test was under way, Mr. J. F. Roe furnished the yards, the necessary lambs, and the feed supplies. Members of the Animal Husbandry Section of the Utah Agricultural Experiment Station have assisted in planning the experimental feeding work and have analyzed the results of the experiments

Ion beam formation in a low-pressure geometrically expanding argon plasma

Supersonic ion beam formation has been observed in a geometrically expanding low-pressure inductively coupled argon plasma. It is found that the ion beam is only observed below 3mTorr and only when the discharge is operated in inductive mode. The geometrical expansion of the plasma induces density and potential gradients leading to the ion beam formation. The ion beam energy increases with decreasing source tube radius. The results show that ion beam formation can be achieved by geometrical expansion alone and that the ion beam energy depends on the ratio of the cross-sectional area of the source and expansion region

Spatial evolution of an ion beam created by a geometrically expanding low-pressure argon plasma

The spatial distribution of an ion beam—created at the interface of a small diameter plasma source and much larger diameter diffusion chamber—is studied in a low-pressure inductively coupled plasma using a retarding field energy analyzer. It is found that the ion beam density decays axially and radially in the diffusion chamber following the expansion of the plasma from the source region. The radial distribution of the ion beam indicates that the acceleration region has a convex shape and is located just outside the source exit, giving rise to a hemispherical plasma expansion into the diffusion chamber

Orbit Selection for the Proposed Lynx Observatory Mission

The Advanced Concepts Office design team performed several analyses and trades in support of orbit selection for the proposed Lynx mission, an x-ray observatory being submitted to the Astro2020 Decadal Survey. Though the descriptions in this Technical Memorandum (TM) focus on the Lynx mission, the approach and process for selecting the final orbit is applicable to a variety of proposed science and exploration missions. To select the best orbit for the Lynx science, mission designers assembled a team of subsystem and discipline experts, in addition to mission analysts, to evaluate several candidate orbits. These discipline experts included members of the science and instrument team, power and avionics, thermal, propulsion, and environments. The goal was to clearly show the benefits and weaknesses of each orbit in the trade space and provide sound justification for the final selection. Discipline experts conducted trades and evaluated the results using a variety of methods including engineering judgement, rough estimates, and detailed calculations, and rolled the results into a final grade using a weighted grading method. The orbit options could then be ranked. The principal investigator (PI) for the mission, along with the science team, was given the task of final orbit selection. The result of the trades indicated that a halo orbit about the second Sun-Earth Lagrange point (SE-L2), similar to the planned orbit for the James Webb Space Telescope (JWST), was the best choice for the Lynx mission. Details of how the team arrived at this selection are below

A productivity collapse to end earth's great oxidation

Author Posting. © National Academy of Sciences, 2019. This article is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences 116 (35), (2019): 17207-17212, doi:10.1073/pnas.1900325116.It has been hypothesized that the overall size of—or efficiency of carbon export from—the biosphere decreased at the end of the Great Oxidation Event (GOE) (ca. 2,400 to 2,050 Ma). However, the timing, tempo, and trigger for this decrease remain poorly constrained. Here we test this hypothesis by studying the isotope geochemistry of sulfate minerals from the Belcher Group, in subarctic Canada. Using insights from sulfur and barium isotope measurements, combined with radiometric ages from bracketing strata, we infer that the sulfate minerals studied here record ambient sulfate in the immediate aftermath of the GOE (ca. 2,018 Ma). These sulfate minerals captured negative triple-oxygen isotope anomalies as low as ∼ −0.8‰. Such negative values occurring shortly after the GOE require a rapid reduction in primary productivity of >80%, although even larger reductions are plausible. Given that these data imply a collapse in primary productivity rather than export efficiency, the trigger for this shift in the Earth system must reflect a change in the availability of nutrients, such as phosphorus. Cumulatively, these data highlight that Earth’s GOE is a tale of feast and famine: A geologically unprecedented reduction in the size of the biosphere occurred across the end-GOE transition.Olivia M. J. Dagnaud assisted during fieldwork. S. V. Lalonde and E. A. Sperling provided helpful comments on an early version of the manuscript. We thank N. J. Planavsky and an anonymous reviewer for their constructive feedback. M.S.W.H. was supported by an NSERC PGS-D and student research grants from National Geographic, the APS Lewis and Clark Fund, Northern Science Training Program, McGill University Graduate Research Enhancement and Travel Awards, Geological Society of America, Mineralogical Association of Canada, and Stanford University. P.W.C. acknowledges support from the University of Colorado Boulder, the Agouron Institute Geobiology postdoctoral Fellowship program, a Natural Sciences and Engineering Council of Canada Postgraduate Scholarship–Doctoral Program scholarship, and the NSTP. Y.P. was supported by the Strategic Priority Research Program of CAS (XDB26000000). T.J.H. thanks Maureen E. Auro for laboratory assistance and the NSF for supporting isotope research in the NIRVANA Labs.2020-02-1

The experiences and perspectives of overseas trained speech and language therapists working in the United Kingdom

There is a growing body of research which has investigated the experience of the migrant health worker. However, only one of these studies has included speech and language therapists thus far, and then only with extremely small numbers. The aim of this study was to explore the experiences and perspectives of migrant speech and language therapists living in the UK. Twenty-three overseas qualified speech and language therapists living in the UK completed an online survey consisting of 36 questions (31 closed question, 5 open-ended questions). The majority of participants came from Australia or the USA and moved to the UK early in their careers. Participants reported a range of benefits from working in another country and more specifically working in the UK. The findings were consistent with other research on migrant health workers regarding known pull factors of travel, finance, and career. This study suggests additional advantages to working in the UK were realised once participants had started working in the UK, such as the UK job lifestyle. Finally, the migrant speech and language therapists were similar in profile to other migrant health workers in terms of age and country of origin previously reported in the literature

Solid polymer fuel cell synthesis by low pressure plasmas: a short review

In this review, we report on the use of low pressure plasmas for elaborating materials at the heart of solid polymer fuel cells (SPFC), especially electrodes and the membrane electrolyte. Electrodes are formed using plasma sputtering techniques while the ion conducting membranes are built up using plasma polymerization. Fuel cell performance will be improved by these approaches. The electrode catalyst profile is optimized while membrane working temperature is increased and methanol crossover is lowered compared to conventional PEM fuel cells.We gratefully thank GdR 2479 PACEM, Université d'Orléans, SPI-CNRS, ACI ECD 2004 (Ministry of Research) for grants and constant support

Access to Dental Care for Children and Young People in Care and Care Leavers: A Global Scoping Review

Aims: This scoping review aimed to explore three research questions: 1. What is the dental care access for children and young people (CYP) in care and care leavers? 2. What factors influence CYP in care and care leavers’ access to dental care? 3. What pathways have been developed to improve access to oral health care for CYP in care and care leavers? Methods: Five databases (Ovid MEDLINE, Ovid Embase, CINAHL, SocINDEX and Dentistry and Oral Sciences Source) and grey literature sources were systematically searched. Articles relating to CYP in care or care leavers aged 0–25 years old, published up to January 2023 were included. Abstracts, posters and publications not in the English language were excluded. The data relating to dental care access were analysed using thematic analysis. Results: The search identified 942 articles, of which 247 were excluded as duplicates. A review of the titles and abstracts yielded 149 studies. Thirty-eight were eligible for inclusion in the review: thirty-three peer-reviewed articles, one PhD thesis and four grey literature sources. All papers were published from very high or medium Human Development Index countries. The studies indicate that despite having higher treatment needs, CYP in care and care leavers experience greater difficulty in accessing dental services than those not care-experienced. Organisational, psycho-social and logistical factors influence their access to dental care. Their experience of dental care may be impacted by adverse childhood events. Pathways to dental care have been developed, but little is known of their impact on access. There are very few studies that include care leavers. The voices of care-experienced CYP are missing from dental access research. Conclusions: care-experienced CYP are disadvantaged in their access to dental care, and there are significant barriers to their treatment needs being met