359 research outputs found

    How Family Stability Affects Children

    Get PDF
    The following commentary serves as a response to the article, “Family Stability and Childhood Behavioral Outcomes: A Critical Review of the Literature.” The review article provides a good overview into family factors affecting children, but falls short in discussing how modifying family factors could change specific child behavioral outcomes. The next step in this field of research is a unified definition of family stability, a standardized measure of family stability, and discussion of how child behavior affects family stability, and how changes in family stability could affect child behavior

    Nitrogen phosphorus and carbox flux in Chesapeake Bay marshes

    Get PDF
    Annual nitrogen, phosphorus and carbon budgets for two Virginia salt marshes were determined .by monthly measurements of water discharge and constituent concentrations over tidal cycles. Considering all three forms of phosphorus measured (total, dissolved organic and orthophosphate) there was a net loss from the estuary to the marches. The data reveal a loss of particulate phosphorus of estuarine origin to marsh sediments and mineralization of this phosphorus in the marshes with subsequent export of dissolved inorganic and organic phosphorus back to the estuary. Nitrogen flux data show a loss of nitrate and nitrite to the marshes. Particulate nitrogen is imported to the marshes where it is mineralized and returned to the estuary as ammonia and dissolved organic nitrogen. The magnitude of nitrogen export suggests significant fixation of atmospheric nitrogen by marsh flora with subsequent export as dissolved species. Carbon flux data show significant contributions of both particulate and dissolved organic carbon to the estuary from the marshes. Estimates of export, based on marsh grass productivity, suggest a loss of 36 and 49 percent of a year\u27s primary production on the marshes as detritus for Ware and Carter Creeks respectively

    Function of marshes in reducing eutrophication of estuaries of the Middle Atlantic Region

    Get PDF
    Annual nitrogen, phosphorus and carbon budgets for two Virginia salt marshes were determined by monthly measurements of water discharge and constituent concentrations over tidal cycles. Considering all three forms of phosphorus measured (total, dissolved organic and orthophosphate) there was a net loss from the estuary to the marshes. The data reveal a loss of particulate μhosphorus of estuarine origin to marsh sediments and mineralization of this phosphorus in the marshes with subsequent export of dissolved inorganic and organic phosphorus back to the estuary. Nitrogen flux data show a loss of nitrate and nitrite to the marshes. Particulate nitrogen is imported to the marshes where it is mineralized and returned to the estuary as ammonia and dissolved organic nitrogen. The magnitude of nitrogen export suggests significant fixation of atmospheric nitrogen by marsh flora with subsequent export as dissolved species. Carbon flux data show significant contributions of both particulate and dissolved organic carbon to the estuary from the marshes. Estimates of export, based on marsh grass productivity, suggest a loss of 36 and 49% of a years primary production on the marshes as detritus for Ware and Carter Creeks respectively

    Progress in Turbulence Detection via GNSS Occultation Data

    Get PDF
    The increased availability of radio occultation (RO) data offers the ability to detect and study turbulence in the Earth's atmosphere. An analysis of how RO data can be used to determine the strength and location of turbulent regions is presented. This includes the derivation of a model for the power spectrum of the log-amplitude and phase fluctuations of the permittivity (or index of refraction) field. The bulk of the paper is then concerned with the estimation of the model parameters. Parameter estimators are introduced and some of their statistical properties are studied. These estimators are then applied to simulated log-amplitude RO signals. This includes the analysis of global statistics derived from a large number of realizations, as well as case studies that illustrate various specific aspects of the problem. Improvements to the basic estimation methods are discussed, and their beneficial properties are illustrated. The estimation techniques are then applied to real occultation data. Only two cases are presented, but they illustrate some of the salient features inherent in real data

    Experimental Verification of Ocean Bounced GPS Signals and Analysis of their Application to Ionospheric Corrections for Satellite Altimetry

    Get PDF
    An algorithm is presented which uses observations of Global Positioning System (GPS) signals reflected from the ocean surface and acquired by a GPS receiver onboard an altimetric satellite to compute the ionospheric delay present in the altimeter measurement. This eliminates the requirement for a dual frequency altimeter for many Earth observing missions. A ground-based experiment is described which confirms the presence of these ocean-bounced signals and demonstrates the potential for altimeter ionospheric correction at the centimeter level

    ODD Symptom Network During Preschool

    Get PDF
    Several different conceptualizations of Oppositional Defiant Disorder (ODD) symptoms have been proposed, including one undivided set of symptoms (DSM-IV-TR; APA 2000); two domains of symptoms subdivided into affective and behavioral; and three domains of symptoms subdivided as angry/irritable, argumentative/defiant, and spiteful. The current study utilizes a novel approach to examining the division of ODD symptoms through use of network analysis. Participants were 109 preschoolers (64 male) between the ages of three and six (M = 4.34 years, SD = 1.08) and their parents and teachers/caregivers, who provided ratings of ODD symptoms. Results are consistent with one-, two-, and three- cluster solutions of ODD, but perhaps provide most support for the three-cluster solution. In addition, results support the idea that negative affect, particularly anger, forms the core of the ODD symptom network during preschool. These results suggest the importance of targeting anger in preschool interventions for ODD

    CLASSIFICATION OF THYMUS-DERIVED AND MARROW-DERIVED LYMPHOCYTES BY DEMONSTRATION OF THEIR ANTIGEN-BINDING CHARACTERISTICS

    Get PDF
    Antigen-binding cells of T and B origin can readily be determined by quantitating the number of sheep erythrocytes per rosette after glutaraldehyde fixation. The T1 and T2 populations have low antigen-binding properties and are very unstable without fixation. The B1 and B2 populations are stable and correlate with precursor and secretory cells. Fixation of rosettes permits a sensitive test for studying differentiation of T and B cells

    Estimating Risk from Ambient Concentrations of Acrolein across the United States

    Get PDF
    BACKGROUND: Estimated ambient concentrations of acrolein, a hazardous air pollutant, are greater than the U.S. Environmental Protection Agency (EPA) reference concentration throughout the United States, making it a concern for human health. However, there is no method for assessing the extent of risk under the U.S. EPA noncancer risk assessment framework. OBJECTIVES: We estimated excess risks from ambient concentrations of acrolein based on dose–response modeling of a study in rats with a relationship between acrolein and residual volume/total lung capacity ratio (RV/TLC) and specific compliance (sC(L)), markers for altered lung function. METHODS: Based on existing literature, we defined values above the 90th percentile for controls as “adverse.” We estimated the increase over baseline response that would occur in the human population from estimated ambient concentrations of acrolein, taken from the U.S. EPA’s National-Scale Air Toxics Assessment for 1999, after standard animal-to-human conversions and extrapolating to doses below the experimental data. RESULTS: The estimated median additional number of adverse sC(L) outcomes across the United States was approximately 2.5 cases per 1,000 people. The estimated range of additional outcomes from the 5th to the 95th percentile of acrolein concentration levels across census tracts was 0.28–14 cases per 1,000. For RV/TLC, the median additional outcome was 0.002 per 1,000, and the additional outcome at the 95th percentile was 0.13 per 1,000. CONCLUSIONS: Although there are uncertainties in estimating human risks from animal data, this analysis demonstrates a method for estimating health risks for noncancer effects and suggests that acrolein could be associated with decreased respiratory function in the United States

    The seventh international RASopathies symposium: Pathways to a cure—expanding knowledge, enhancing research, and therapeutic discovery

    Get PDF
    RASopathies are a group of genetic disorders that are caused by genes that affect the canonical Ras/mitogen-activated protein kinase (MAPK) signaling pathway. Despite tremendous progress in understanding the molecular consequences of these genetic anomalies, little movement has been made in translating these findings to the clinic. This year, the seventh International RASopathies Symposium focused on expanding the research knowledge that we have gained over the years to enhance new discoveries in the field, ones that we hope can lead to effective therapeutic treatments. Indeed, for the first time, research efforts are finally being translated to the clinic, with compassionate use of Ras/MAPK pathway inhibitors for the treatment of RASopathies. This biannual meeting, organized by the RASopathies Network, brought together basic scientists, clinicians, clinician scientists, patients, advocates, and their families, as well as representatives from pharmaceutical companies and the National Institutes of Health. A history of RASopathy gene discovery, identification of new disease genes, and the latest research, both at the bench and in the clinic, were discussed
    corecore