3,864 research outputs found

    Possible Observational Criteria for Distinguishing Brown Dwarfs from Planets

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    The difference in formation process between binary stars and planetary systems is reflected in their composition as well as their orbital architecture, particularly orbital eccentricity as a function of orbital period. It is suggested here that this difference can be used as an observational criterion to distinguish between brown dwarfs and planets. Application of the orbital criterion suggests that with three possible exceptions, all of the recently-discovered substellar companions discovered to date may be brown dwarfs and not planets. These criterion may be used as a guide for interpretation of the nature of sub-stellar mass companions to stars in the future.Comment: LaTeX, 11 pages including 2 figures, accepted for publication in the Astrophysical Journal Letter

    Investigating Potential Biomarkers in Autism Spectrum Disorder

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    Background: Early identification and treatment of individuals with autism spectrum disorder (ASD) improves outcomes, but specific evidence needed to individualize treatment recommendations is lacking. Biomarkers that could be routinely measured within the clinical setting could potentially transform clinical care for patients with ASD. This demonstration project employed collection of biomarker data during regular autism specialty clinical visits and explored the relationship of biomarkers with clinical ASD symptoms. Methods: Eighty-three children with ASD, aged 5-10 years, completed a multi-site feasibility study integrating the collection of biochemical (blood serotonin, urine melatonin sulfate excretion) and clinical (head circumference, dysmorphology exam, digit ratio, cognitive and behavioral function) biomarkers during routine ASD clinic visits. Parents completed a demographic survey and the Aberrant Behavior Checklist-Community. Cognitive function was determined by record review. Data analysis utilized Wilcoxon two-sample tests and Spearman correlations. Results: Participants were 82% male, 63% White, 19% Hispanic, with a broad range of functioning. Group means indicated hyperserotonemia. In a single regression analysis adjusting for race and median household income, higher income was associated with higher levels of blood serotonin and urine melatonin sulfate excretion levels (p = 0.004 and p = 0.04, respectively). Melatonin correlated negatively with age (p = 0.048) and reported neurologic problems (p = 0.02). Dysmorphic status correlated with higher reported stereotyped behavior (p = 0.02) and inappropriate speech (p = 0.04). Conclusion: This demonstration project employed collection of multiple biomarkers, allowed for examination of associations between biochemical and clinical measures, and identified several findings that suggest direction for future studies. This clinical research model has promise for integrative biomarker research in individuals with complex, heterogeneous neurodevelopmental disorders such as ASD

    Nkx2-5 and Sarcospan genetically interact in the development of the muscular ventricular septum of the heart

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    The muscular ventricular septum separates the flow of oxygenated and de-oxygenated blood in air-breathing vertebrates. Defects within it, termed muscular ventricular septal defects (VSDs), are common, yet less is known about how they arise than rarer heart defects. Mutations of the cardiac transcription factor NKX2-5 cause cardiac malformations, including muscular VSDs. We describe here a genetic interaction between Nkx2-5 and Sarcospan (Sspn) that affects the risk of muscular VSD in mice. Sspn encodes a protein in the dystrophin-glycoprotein complex. Sspn knockout (Sspn(KO)) mice do not have heart defects, but Nkx2-5(+/−)/Sspn(KO) mutants have a higher incidence of muscular VSD than Nkx2-5(+/−) mice. Myofibers in the ventricular septum follow a stereotypical pattern that is disrupted around a muscular VSD. Subendocardial myofibers normally run in parallel along the left ventricular outflow tract, but in the Nkx2-5(+/−)/Sspn(KO) mutant they commonly deviate into the septum even in the absence of a muscular VSD. Thus, Nkx2-5 and Sspn act in a pathway that affects the alignment of myofibers during the development of the ventricular septum. The malalignment may be a consequence of a defect in the coalescence of trabeculae into the developing ventricular septum, which has been hypothesized to be the mechanistic basis of muscular VSDs

    Phase I/II Archaeological Testing on Fleet Street (18AP111), Cornhill Street (18AP112), and 26 Market Space (18AP109), for the Proposed Fleet and Cornhill Streets Reconstruction Project, Annapolis, Maryland, 2008

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    From 3/31/08 to 5/30/08 staff from the Department of Anthropology, University of Maryland, College Park (UMCP), Archaeology in Annapolis Project, conducted archaeological testing on city-owned public right-of-ways at 26 Market Space (18AP109), on Fleet Street (18AP111), and on Cornhill Street (18AP112) prior to the upcoming undergrounding and replacement of city-owned utilities along and beneath these streets. In addition, from 06/02/08 to 06/20/08, undergraduate and graduate students enrolled in the University of Maryland, Field School in Urban Archaeology conducted further testing of city-owned public right-of-ways on Cornhill Street (18AP112). This Phase II investigation has been conducted at the request of the City of Annapolis, Department of Public Works (DPW) as part of the Fleet and Cornhill Streets Reconstruction Project. The project area comprises the streetscapes of what is referred to as the Fleet-Cornhill neighborhood. Eleven test units were used to evaluate archaeological integrity and significance of these sites and to evaluate the potential effects of planned construction on archaeological resources. Background research shows that the Fleet Street neighborhood was initially developed in the late 17th and early 18th century. Throughout the later 18th, 19th and 20th centuries the area became known as an ethnically diverse working class neighborhood in the heart of the city. Historical residents of the project area have included in the early 20th century native people of European, African descent, and a community of Russian Ashkenazi Jews in the early 20th century. Previous archaeological investigations found evidence of intact archaeological resources within the project area dating from the 18th to 20th centuries. In addition to providing evidence of patterns of Annapolis’ historical urbanization, several features excavated in the course of this project have shed light on the development of public space within this working class neighborhood. These features include a corduroy or log road dating to the first quarter of the 18th century; what is believed to be a Yoruba ritual bundle dating to the first quarter of the 18th century; and a series of city improvements (i.e. curbs, sidewalks, and a public well) dating from the 18th through 20th centuries. A high degree of archaeological integrity at all three sites has the potential to add considerable knowledge concerning both Annapolis city development, and an ethnically diverse working class community. All three sites are eligible for inclusion in the National Register of Historic Places under Criterion D. Because of the integrity and uniqueness of the archaeological record within the project area, it is recommended that further archaeological research be done. Included within this recommendation is the need to process flotation and macrobotanical samples recovered in the fiel

    The Role of Glutamate and GABA in Autism Spectrum Disorders: Pilot Results from a Proton Magnetic Resonance Spectroscopy Study

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    Objectives: To measure the levels of glutamate, a major excitatory neurotransmitter; glutamine, a metabolite of glutamate; and γ-aminobutyric acid (GABA), a major inhibitory neurotransmitter; in a pilot study of proton magnetic resonance spectroscopy (1H-MRS) findings in adolescents with Autism Spectrum Disorders (ASD). Methods: The subjects were assessed with the Autism Diagnostic Observation Schedule (ADOS), the Reading the Mind in the Eyes test (RMET) and the Social Responsiveness Scale (SRS). 1H-MRS measures of the anterior cingulate cortex were conducted using a Philips 3.0 T scanner. Results: To date, we have completed the data analysis on 18 subjects, 8 with ASD and 10 healthy control (HC) subjects. There was no significant difference between the combined glutamate + glutamine concentrations as measured by 1H-MRS (ASD = 12.0 ± 0.9 IU, HC = 11.6 ± 0.8 IU, p = 0.37). However, there was a higher than average glutamine level in the ASD group compared to healthy controls (ASD = 2.4 ± 0.2 IU, HC = 1.9 ± 0.3 IU, p = 0.01). This was accompanied by a trend toward lower GABA/Cr levels in the ASD group (ASD = 0.073 ± 0.010, HC = 0.082 ± 0.010, p = 0.06). Glutamine levels in the ACC were correlated positively with deficits of social cognition across groups (higher SRS, lower RMET scores). Those with higher glutamine levels made more errors when identifying emotions in the RMET task (r(10) = -0.77, p = 0.009), and also had more clinically significant scores on the SRS (r(10) = 0.87, p = 0.001). Conclusions: Our results present evidence that glutamine levels measured within the ACC region are higher for adolescent males with ASD than age-matched HC males, and signal that GABA levels may also be decreased in this region. These changes are correlated with deficits in social cognition

    Breast cancer in lesbians and bisexual women: Systematic review of incidence, prevalence and risk studies

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    This article is made available through the Brunel Open Access Publishing Fund. © 2013 Meads and Moore; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: The UK Parliamentary Enquiry and USA Institute of Medicine state that lesbians may be at a higher risk of breast cancer but there is insufficient information. Lesbians and bisexual (LB) women have behavioural risk-factors at higher rates compared to heterosexuals such as increased alcohol intake and higher stress levels. Conversely, breast cancer rates are higher in more affluent women yet income levels in LB women are relatively low. This systematic review investigated all evidence on whether there is, or likely to be, higher rates of breast cancer in LB women. Methods: Cochrane library (CDSR, CENTRAL, HTA, DARE, NHSEED), MEDLINE, EMBASE, PsychINFO, CAB abstracts, Web of Science (SCI, SSCI), SIGLE and Social Care Online databases were searched to October 2013. Unpublished research and specific lesbian, gay and bisexual websites were checked, as were citation lists of relevant papers. Included were studies in LB populations reporting breast cancer incidence or prevalence rates, risk model results or risk-factor estimates. Inclusions, data-extraction and quality assessment were by two reviewers with disagreements resolved by discussion. Results: Searches found 198 references. No incidence rates were found. Nine studies gave prevalence estimates - two showed higher, four showed no differences, one showed mixed results depending on definitions, one had no comparison group and one gave no sample size. All studies were small with poor methodological and/or reporting quality. One incidence modelling study suggested a higher rate. Four risk modelling studies were found, one Rosner-Colditz and three Gail models. Three suggested higher and one lower rate in LB compared to heterosexual women. Six risk-factor estimates suggested higher risk and one no difference between LB and heterosexual women. Conclusions: The only realistic way to establish rates in LB women would be to collect sexual orientation within routine statistics, including cancer registry data, or from large cohort studies
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