El espectroheliógrafo del Observatorio de Física Cósmica de San Miguel

El espectroheliógrafo de San Miguel (cfr. Inf. Bull.South. Hem. N° 15) ha comenzado a operar en marzo del presente año. Presentaremos aquí únicamente una breve descripción del mismo. El instrumento ha sido diseñado por el Dr. M. Miller S. I. y construido por la American Optical Company (U.S.A.); está instalado en una torre de hormigón protegida por un segundo edificio (ver figura). A 12,50 m del suelo, protegido por una cúpula corrediza, se encuentra el celóstato sistema Lippmann, compuesto por dos espejos planos de 405 mm de diámetro. El telescopio en sí es un sistema gregoriano fuera de eje. Su primario es parabólico de 305 mm de diámetro y su secundario es elíptico de 203 mm. La distancia focal equivalente del sistema es de 7320 mm y da una imagen del sol de unos 68 mm sobre la rendija del espectrógrafo. El espectroheliógrafo cuenta con monocromador tipo Lyot centrado en la línea H-alfa que se utiliza como equipo auxiliar de patrullaje y para elegir la zona de la cual se quiere obtener el espectro. El espectrógrafo propiamente dicho está ubicado dentro de un tanque en el cual se puede hacer un vacío del orden de los 5 mm de Hg. Consta de dos espejos colimadores y una red de difracción de 600 líneas/min construida por Bausch & Lomb con una superficie útil de 154 X 206 mm con un ángulo de tallado de 28® 41’. La dispersión de la red varía entre 0,6 y 3 Å/mm, según el orden elegido.Asociación Argentina de Astronomí

El espectroheliógrafo del Observatorio de Física Cósmica de San Miguel

El espectroheliógrafo de San Miguel (cfr. Inf. Bull.South. Hem. N° 15) ha comenzado a operar en marzo del presente año. Presentaremos aquí únicamente una breve descripción del mismo. El instrumento ha sido diseñado por el Dr. M. Miller S. I. y construido por la American Optical Company (U.S.A.); está instalado en una torre de hormigón protegida por un segundo edificio (ver figura). A 12,50 m del suelo, protegido por una cúpula corrediza, se encuentra el celóstato sistema Lippmann, compuesto por dos espejos planos de 405 mm de diámetro. El telescopio en sí es un sistema gregoriano fuera de eje. Su primario es parabólico de 305 mm de diámetro y su secundario es elíptico de 203 mm. La distancia focal equivalente del sistema es de 7320 mm y da una imagen del sol de unos 68 mm sobre la rendija del espectrógrafo. El espectroheliógrafo cuenta con monocromador tipo Lyot centrado en la línea H-alfa que se utiliza como equipo auxiliar de patrullaje y para elegir la zona de la cual se quiere obtener el espectro. El espectrógrafo propiamente dicho está ubicado dentro de un tanque en el cual se puede hacer un vacío del orden de los 5 mm de Hg. Consta de dos espejos colimadores y una red de difracción de 600 líneas/min construida por Bausch & Lomb con una superficie útil de 154 X 206 mm con un ángulo de tallado de 28® 41’. La dispersión de la red varía entre 0,6 y 3 Å/mm, según el orden elegido.Asociación Argentina de Astronomí

El espectroheliógrafo del Observatorio de Física Cósmica de San Miguel

El espectroheliógrafo de San Miguel (cfr. Inf. Bull.South. Hem. N° 15) ha comenzado a operar en marzo del presente año. Presentaremos aquí únicamente una breve descripción del mismo. El instrumento ha sido diseñado por el Dr. M. Miller S. I. y construido por la American Optical Company (U.S.A.); está instalado en una torre de hormigón protegida por un segundo edificio (ver figura). A 12,50 m del suelo, protegido por una cúpula corrediza, se encuentra el celóstato sistema Lippmann, compuesto por dos espejos planos de 405 mm de diámetro. El telescopio en sí es un sistema gregoriano fuera de eje. Su primario es parabólico de 305 mm de diámetro y su secundario es elíptico de 203 mm. La distancia focal equivalente del sistema es de 7320 mm y da una imagen del sol de unos 68 mm sobre la rendija del espectrógrafo. El espectroheliógrafo cuenta con monocromador tipo Lyot centrado en la línea H-alfa que se utiliza como equipo auxiliar de patrullaje y para elegir la zona de la cual se quiere obtener el espectro. El espectrógrafo propiamente dicho está ubicado dentro de un tanque en el cual se puede hacer un vacío del orden de los 5 mm de Hg. Consta de dos espejos colimadores y una red de difracción de 600 líneas/min construida por Bausch & Lomb con una superficie útil de 154 X 206 mm con un ángulo de tallado de 28® 41’. La dispersión de la red varía entre 0,6 y 3 Å/mm, según el orden elegido.Asociación Argentina de Astronomí

SPR Perspectives: scientific opportunities in the Environmental influences on Child Health Outcomes Program

Drawing upon extant data from existing pediatric cohorts and new follow-up of a diverse set of pediatric cohorts from across the United States, the Environmental influences on Child Health Outcomes (ECHO) Program creates the opportunity for novel and innovative investigations of many previously inaccessible scientific questions in the area of child health. We describe how the large sample size, diversity of participants, emphasis on team science, and infrastructure for improving research methodology make the ECHO Program a major research resource for improving our understanding of early life determinants of childhood health and well-being. Pediatric researchers leverage the unique features of the ECHO Program to address research questions with the potential to yield far-reaching and long-term impacts on child health. IMPACT: The ECHO Program unites pediatric cohorts from across the United States, allowing for investigations of compelling research questions that were previously infeasible due to limited sample sizes or lack of participant diversity. The focus of the ECHO Program on team science, solution-oriented research, and methodological innovation propels novel scientific investigations that are responsive to the needs of a wide range of stakeholders. Features of the ECHO program\u27s infrastructure poise its investigators to rapidly launch research endeavors that are responsive to time-sensitive and critical needs within the realm of pediatric research

Response to Professor Olsen's Commentary on ‘Random Sampling – Is It Worth It?’

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94518/1/ppe12019.pd

Elevated Endogenous Erythropoietin Concentrations Are Associated with Increased Risk of Brain Damage in Extremely Preterm Neonates

Background We sought to determine, in very preterm infants, whether elevated perinatal erythropoietin (EPO) concentrations are associated with increased risks of indicators of brain damage, and whether this risk differs by the co-occurrence or absence of intermittent or sustained systemic inflammation (ISSI). Methods Protein concentrations were measured in blood collected from 786 infants born before the 28th week of gestation. EPO was measured on postnatal day 14, and 25 inflammation-related proteins were measured weekly during the first 2 postnatal weeks. We defined ISSI as a concentration in the top quartile of each of 25 inflammation-related proteins on two separate days a week apart. Hypererythropoietinemia (hyperEPO) was defined as the highest quartile for gestational age on postnatal day 14. Using logistic regression and multinomial logistic regression models, we compared risks of brain damage among neonates with hyperEPO only, ISSI only, and hyperEPO+ISSI, to those who had neither hyperEPO nor ISSI, adjusting for gestational age. Results Newborns with hyperEPO, regardless of ISSI, were more than twice as likely as those without to have very low (< 55) Mental (OR 2.3; 95% CI 1.5-3.5) and/or Psychomotor (OR 2.4; 95% CI 1.6-3.7) Development Indices (MDI, PDI), and microcephaly at age two years (OR 2.4; 95%CI 1.5-3.8). Newborns with both hyperEPO and ISSI had significantly increased risks of ventriculomegaly, hemiparetic cerebral palsy, microcephaly, and MDI and PDI < 55 (ORs ranged from 2.2-6.3), but not hypoechoic lesions or other forms of cerebral palsy, relative to newborns with neither hyperEPO nor ISSI. Conclusion hyperEPO, regardless of ISSI, is associated with elevated risks of very low MDI and PDI, and microcephaly, but not with any form of cerebral palsy. Children with both hyperEPO and ISSI are at higher risk than others of very low MDI and PDI, ventriculomegaly, hemiparetic cerebral palsy, and microcephaly

Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals

We briefly summarize the reported anomalous effects in deuterated metals at ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on important experiments as well as the theoretical basis for the opposition to interpreting them as cold fusion. Then we critically examine more than 25 theoretical models for CF, including unusual nuclear and exotic chemical hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure

Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradox

This article discusses three statistical paradoxes that pervade epidemiological research: Simpson's paradox, Lord's paradox, and suppression. These paradoxes have important implications for the interpretation of evidence from observational studies. This article uses hypothetical scenarios to illustrate how the three paradoxes are different manifestations of one phenomenon – the reversal paradox – depending on whether the outcome and explanatory variables are categorical, continuous or a combination of both; this renders the issues and remedies for any one to be similar for all three. Although the three statistical paradoxes occur in different types of variables, they share the same characteristic: the association between two variables can be reversed, diminished, or enhanced when another variable is statistically controlled for. Understanding the concepts and theory behind these paradoxes provides insights into some controversial or contradictory research findings. These paradoxes show that prior knowledge and underlying causal theory play an important role in the statistical modelling of epidemiological data, where incorrect use of statistical models might produce consistent, replicable, yet erroneous results

Implementing Provider‐based Sampling for the National Children's Study: Opportunities and Challenges

Background:  The National Children's Study (NCS) was established as a national probability sample of births to prospectively study children's health starting from in utero to age 21. The primary sampling unit was 105 study locations (typically a county). The secondary sampling unit was the geographic unit (segment), but this was subsequently perceived to be an inefficient strategy. Methods and Results:  This paper proposes that second‐stage sampling using prenatal care providers is an efficient and cost‐effective method for deriving a national probability sample of births in the US. It offers a rationale for provider‐based sampling and discusses a number of strategies for assembling a sampling frame of providers. Also presented are special challenges to provider‐based sampling pregnancies, including optimising key sample parameters, retaining geographic diversity, determining the types of providers to include in the sample frame, recruiting women who do not receive prenatal care, and using community engagement to enrol women. There will also be substantial operational challenges to sampling provider groups. Conclusion:  We argue that probability sampling is mandatory to capture the full variation in exposure and outcomes expected in a national cohort study, to provide valid and generalisable risk estimates, and to accurately estimate policy (such as screening) benefits from associations reported in the NCS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94504/1/ppe12005.pd