256 research outputs found

    Companions of Stars: From Other Stars to Brown Dwarfs to Planets: The Discovery of the First Methane Brown Dwarf

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    The discovery of the first methane brown dwarf provides a framework for describing the important advances in both fundamental physics and astrophysics that are due to the study of companions of stars. I present a few highlights of the history of this subject along with details of the discovery of the brown dwarf Gliese 229B. The nature of companions of stars is discussed with an attempt to avoid biases induced by anthropocentric nomenclature. With the newer types of remote reconnaissance of nearby stars and their systems of companions, an exciting and perhaps even more profound set of contributions to science is within reach in the near future. This includes an exploration of the diversity of planets in the universe and perhaps soon the first solid evidence for biological activity outside our Solar System.Comment: 31 pages, 13 figure

    Differentiated thyroid carcinoma in children and adolescents

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    From 1936 to 1990, 89 children and adolescents (72 girls and 17 boys) were treated for differentiated thyroid carcinoma at the University of Michigan Medical Center; 58 of these patients were first reported in 1971. Thirty (34%) patients had previously received external irradiation to the head and neck, although only 1 (3%) patient of the last 33 patients seen had this history. Patients first presenting from 1971 to 1990 had less advanced disease than those seen earlier. Also, during this time period, the rate of initial palpable cervical adenopathy fell from 63% to 36%, local infiltration of primary cancer from 31% to 6%, and initial pulmonary metastases from 19% to 6%. The incidence of cervical nodal metastases has remained 88% for 54 years. Papillary or the follicular variant of papillary carcinoma was found in 93% of all patients. Seventy-nine (89%) patients had total or completion total thyroidectomy. Surgical management of lymphatic metastases varied from regional excision of nodes to radical neck dissection. The overall rate of permanent accidental recurrent laryngeal nerve palsy and hypoparathyroidism was 4.5%, although neither has occurred in a child or adolescent undergoing surgery at the center in the past 25 years. The most recent 33 patients had a low rate of local/regional persistence or recurrence. Cervical nodal persistence occurred in 21%; there were no thyroid recurrences. Eighty-two percent of patients received 131 I. The long-term mortality rate was 2.2%. We continue to advocate total thyroidectomy, cervical lymph node dissection, and postoperative 131 I therapy as the most conservative treatment regimen for children with differentiated thyroid carcinoma. Entre 1936 et 1990, 89 enfants et adolescents (72 filles et 17 garons) ont été traités pour cancer différencie de la thyroïde au Centre Médical de l'Université de Michigan. Cinquante huit d'entre eux ont fait l'objet d'une publication en 1971. Trente de ces patients (34%) avaient eu une radiothérapie externe au niveau de la tête et/ou du cou, mais ce facteur n'a été retrouvé que chez un des 33 derniers patients (3%). Les patients vus entre 1971 et 1990 avaient une maladie moins avancée. Pendant cette période, le taux d'adénopathies cervicales palpables est passée de 63 à 36%; le pourcentage de patients ayant une infiltration locale, de 31 à 6%, et celui de métastases pulmonaires de 19 à 6%. L'incidence des métastases ganglionnaires cervicales, par contre, est restée de 88% depuis 54 ans. Le cancer était papillaire ou folliculaire dans 93% des cas. Soixante-neuf patients (89%) ont eu une thyroïdectomie totale, soit d'embl%ee soit secondairement. La thérapeutique des métastases ganglionnaires a varié depuis l'exérèse régionale et le curage ganglionnaire cervical. Le taux global de paralysie récurrentielle et de l'hypoparathyroïde était de 4.5%, mais aucune de ces deux complications n'a été observée pour les enfants opérés dans notre centre au cours des 25 dernières années. Parmi les 33 derniers patients, le taux de tissu résiduel ou de récidive était bas. Dans 21% des cas, il persistait du tissu néoplasique après chirurgie, sans récidive. Quatre-vingt pour cent de ces patients ont eu un traitement par l'iode 131. La mortalité à distance était de 2.2%. Nous continuous de recommander une thyroïdectomie totale, une lymphadénectomie cervicale et une iodothérapie post-opératoire par l'iode 131 comme le traitement les plus conservateurs du cancer différencié de la thyroïde chez l'enfant. Ochenta y nueve niños y adolescentes (72 de sexo femenino y 17 de sexo masculino) fuiron tratados por carcinoma tiroideo diferenciado en el Centro Médico de la Universidad de Michigan; 58 de estos pacientes fueron reportados por primera vez en 1971. Treinta pacientes (34%) tenían historia de irradiación a la cabeza y el cuello; sin embargo, solamente uno de los últimos 33 (3%) presentó tal historia. Los pacientes vistos entre 1971 y 1990 exhibían enfermedad menos avanzada que aquellos vistos previamente. Así mismo, la incidencia de adenopatías cervicales palpables descendió de 63% a 36%, la de infiltración local por cáncer primario de 31% a 6% y la de metástasis pulmonares iniciales de 19% a 6%. La incidencia de metástasis ganglionares cervicales se ha mantenido en 88% por 54 años. La variante papilar o folicular del carcinoma papilar se encontró en 93% de los pacientes de la serie. Setenta y nueve pacientes (89%) fueron sometidos a toroidectomía total o a reoperación para completar la tiroidectomía total. El manejo quirúrgico de las metástasis linfáticas varió desde la resección regional de los ganglios hasta la disección radical del cuello. La tasa global de lesión accidental, permanente o temporal, del nervio recurrente laríngeo y de hopoparatiroidismo fue 4.5%, aunque ninguna de estas complicaciones ha ocurrido en un niño o en un adolescente sometido a cirugía en nuestro centro médico en los últimos 25 años. Los últimos 33 pacientes exhibieron una tasa reducida de persistencia o de recurrencia local/regional. La persistencia ganglionar cervical se presentó en 21% de los casos; no hubo recurrencias tiroideas. Ochenta y dos por ciento de los pacientes recibió 131 I. La tassa de mortalidad a largo plazo fui 2.2%. Nuestro grupo continúa preconizando tiroidectomía total, disección ganglionar cervical y terapia postoperatoria con 131 I como la modalidad terapéutica más conservadora en carcinoma diferenciado de la glándula tiroidea en la niñez.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41290/1/268_2005_Article_BF02067317.pd

    Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice

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    Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales

    Anemia prevalence in women of reproductive age in low- and middle-income countries between 2000 and 2018

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    Anemia is a globally widespread condition in women and is associated with reduced economic productivity and increased mortality worldwide. Here we map annual 2000–2018 geospatial estimates of anemia prevalence in women of reproductive age (15–49 years) across 82 low- and middle-income countries (LMICs), stratify anemia by severity and aggregate results to policy-relevant administrative and national levels. Additionally, we provide subnational disparity analyses to provide a comprehensive overview of anemia prevalence inequalities within these countries and predict progress toward the World Health Organization’s Global Nutrition Target (WHO GNT) to reduce anemia by half by 2030. Our results demonstrate widespread moderate improvements in overall anemia prevalence but identify only three LMICs with a high probability of achieving the WHO GNT by 2030 at a national scale, and no LMIC is expected to achieve the target in all their subnational administrative units. Our maps show where large within-country disparities occur, as well as areas likely to fall short of the WHO GNT, offering precision public health tools so that adequate resource allocation and subsequent interventions can be targeted to the most vulnerable populations.Peer reviewe

    Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

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    Global, regional, and national under-5 mortality, adult mortality, age-specific mortality, and life expectancy, 1970–2016: a systematic analysis for the Global Burden of Disease Study 2016

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    BACKGROUND: Detailed assessments of mortality patterns, particularly age-specific mortality, represent a crucial input that enables health systems to target interventions to specific populations. Understanding how all-cause mortality has changed with respect to development status can identify exemplars for best practice. To accomplish this, the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) estimated age-specific and sex-specific all-cause mortality between 1970 and 2016 for 195 countries and territories and at the subnational level for the five countries with a population greater than 200 million in 2016. METHODS: We have evaluated how well civil registration systems captured deaths using a set of demographic methods called death distribution methods for adults and from consideration of survey and census data for children younger than 5 years. We generated an overall assessment of completeness of registration of deaths by dividing registered deaths in each location-year by our estimate of all-age deaths generated from our overall estimation process. For 163 locations, including subnational units in countries with a population greater than 200 million with complete vital registration (VR) systems, our estimates were largely driven by the observed data, with corrections for small fluctuations in numbers and estimation for recent years where there were lags in data reporting (lags were variable by location, generally between 1 year and 6 years). For other locations, we took advantage of different data sources available to measure under-5 mortality rates (U5MR) using complete birth histories, summary birth histories, and incomplete VR with adjustments; we measured adult mortality rate (the probability of death in individuals aged 15-60 years) using adjusted incomplete VR, sibling histories, and household death recall. We used the U5MR and adult mortality rate, together with crude death rate due to HIV in the GBD model life table system, to estimate age-specific and sex-specific death rates for each location-year. Using various international databases, we identified fatal discontinuities, which we defined as increases in the death rate of more than one death per million, resulting from conflict and terrorism, natural disasters, major transport or technological accidents, and a subset of epidemic infectious diseases; these were added to estimates in the relevant years. In 47 countries with an identified peak adult prevalence for HIV/AIDS of more than 0·5% and where VR systems were less than 65% complete, we informed our estimates of age-sex-specific mortality using the Estimation and Projection Package (EPP)-Spectrum model fitted to national HIV/AIDS prevalence surveys and antenatal clinic serosurveillance systems. We estimated stillbirths, early neonatal, late neonatal, and childhood mortality using both survey and VR data in spatiotemporal Gaussian process regression models. We estimated abridged life tables for all location-years using age-specific death rates. We grouped locations into development quintiles based on the Socio-demographic Index (SDI) and analysed mortality trends by quintile. Using spline regression, we estimated the expected mortality rate for each age-sex group as a function of SDI. We identified countries with higher life expectancy than expected by comparing observed life expectancy to anticipated life expectancy on the basis of development status alone. FINDINGS: Completeness in the registration of deaths increased from 28% in 1970 to a peak of 45% in 2013; completeness was lower after 2013 because of lags in reporting. Total deaths in children younger than 5 years decreased from 1970 to 2016, and slower decreases occurred at ages 5-24 years. By contrast, numbers of adult deaths increased in each 5-year age bracket above the age of 25 years. The distribution of annualised rates of change in age-specific mortality rate differed over the period 2000 to 2016 compared with earlier decades: increasing annualised rates of change were less frequent, although rising annualised rates of change still occurred in some locations, particularly for adolescent and younger adult age groups. Rates of stillbirths and under-5 mortality both decreased globally from 1970. Evidence for global convergence of death rates was mixed; although the absolute difference between age-standardised death rates narrowed between countries at the lowest and highest levels of SDI, the ratio of these death rates-a measure of relative inequality-increased slightly. There was a strong shift between 1970 and 2016 toward higher life expectancy, most noticeably at higher levels of SDI. Among countries with populations greater than 1 million in 2016, life expectancy at birth was highest for women in Japan, at 86·9 years (95% UI 86·7-87·2), and for men in Singapore, at 81·3 years (78·8-83·7) in 2016. Male life expectancy was generally lower than female life expectancy between 1970 and 2016, an

    Volume I. Introduction to DUNE

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology
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