311 research outputs found

    The Relative Importance of Patch Area and Perimeter–Area Ratio to Grassland Breeding Birds

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    Habitat fragmentation has been implicated as a major cause of population decline in grassland birds. We tested the hypothesis that a combination of area and shape determines the use of grassland patches by breeding birds. We compared both species richness and individual species presence in 45 wet meadow grasslands in the floodplain of the central Platte River, Nebraska. Bird data were collected through the use of belt transects and supplemented by walking and listening outside transects. Our data supported our primary hypothesis that perimeter–area ratio, which reflects both the area and shape of a patch, is the strongest predictor of both individual species presence and overall species richness. The probability of occurrence for all six common species (Grasshopper Sparrows, Bobolinks, Upland Sandpipers, Western Meadowlarks, Dickcissels, and Red-winged Blackbirds) was significantly inversely correlated with perimeter–area ratio. The probability of occurrence of Grasshopper Sparrows, Bobolinks, Upland Sandpipers, and Western Meadowlarks was also correlated with area. We conclude that species richness is maximized when patches are large (\u3e50 ha) and shaped so that they provide abundant interior areas, free from the impacts of edges

    The Relative Importance of Patch Area and Perimeter–Area Ratio to Grassland Breeding Birds

    Get PDF
    Habitat fragmentation has been implicated as a major cause of population decline in grassland birds. We tested the hypothesis that a combination of area and shape determines the use of grassland patches by breeding birds. We compared both species richness and individual species presence in 45 wet meadow grasslands in the floodplain of the central Platte River, Nebraska. Bird data were collected through the use of belt transects and supplemented by walking and listening outside transects. Our data supported our primary hypothesis that perimeter–area ratio, which reflects both the area and shape of a patch, is the strongest predictor of both individual species presence and overall species richness. The probability of occurrence for all six common species (Grasshopper Sparrows, Bobolinks, Upland Sandpipers, Western Meadowlarks, Dickcissels, and Red-winged Blackbirds) was significantly inversely correlated with perimeter–area ratio. The probability of occurrence of Grasshopper Sparrows, Bobolinks, Upland Sandpipers, and Western Meadowlarks was also correlated with area. We conclude that species richness is maximized when patches are large (\u3e50 ha) and shaped so that they provide abundant interior areas, free from the impacts of edges

    The Electrical Structure of Thunderstorms

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    The time histories of thunderstorm charge distribution during three storms occurring during the summer of 1940 in the vicinity of the Albuquerque Airport were investigated by the use of eight synchronized recording electrometers arranged in a particular pattern over a field 1.6 kilometers above sea level

    Assessing Inclusion Behaviors and Impact of Inclusion within the Fleet

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    NPS NRP Executive SummaryThis project supports the Navy’s efforts to promote diversity and inclusion (D&I), which are recognized as strategic imperatives that give the Navy a warfighting advantage against our adversaries. The study utilizes both quantitative and qualitative approaches to understand the major contributing factors to an inclusive and diverse command, accomplishing four research objectives: (1) developing metrics to assess behaviors of inclusion within the fleet; (2) assessing inclusion behaviors within the fleet using the developed metrics; (3) determining the most impactful D&I competencies for building inclusion; and (4) identifying command practices that contribute to greater acceptance of diversity. We develop and introduce a survey instrument to assess Personal Inclusion Factors (individuals’ feelings of being personally included within their command) and Command Core Inclusion Competencies (individuals’ beliefs about how their commands demonstrate practices that promote diversity and inclusion) suitable for a Navy context. The instrument captures best practices and validated metrics for promoting and assessing D&I in organizations and tailors them to the Navy and Sailors’ work. We fielded this survey to 489 active-duty Navy personnel (enlisted and officers) asking them to report on both their current and past commands. We find that females across all race/ethnicities on average report lower feelings of inclusion and rate commands lower on Core Command Inclusion Competencies than their male counterparts. This gender difference is stronger for sea versus shore commands. Participants also answered open-ended questions about the competencies that they believed were most important for promoting D&I in the fleet. "Inclusive leadership" emerged as a dominant theme; in particular, participants felt most included in commands where leadership valued their perspectives and ideas and where Sailors felt heard on a day-in, day-out basis.N1 - Manpower, Personnel, Training & EducationThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

    Assessing Inclusion Behaviors and Impact of Inclusion within the Fleet

    Get PDF
    NPS NRP Project PosterThis project supports the Navy’s efforts to promote diversity and inclusion (D&I), which are recognized as strategic imperatives that give the Navy a warfighting advantage against our adversaries. The study utilizes both quantitative and qualitative approaches to understand the major contributing factors to an inclusive and diverse command, accomplishing four research objectives: (1) developing metrics to assess behaviors of inclusion within the fleet; (2) assessing inclusion behaviors within the fleet using the developed metrics; (3) determining the most impactful D&I competencies for building inclusion; and (4) identifying command practices that contribute to greater acceptance of diversity. We develop and introduce a survey instrument to assess Personal Inclusion Factors (individuals’ feelings of being personally included within their command) and Command Core Inclusion Competencies (individuals’ beliefs about how their commands demonstrate practices that promote diversity and inclusion) suitable for a Navy context. The instrument captures best practices and validated metrics for promoting and assessing D&I in organizations and tailors them to the Navy and Sailors’ work. We fielded this survey to 489 active-duty Navy personnel (enlisted and officers) asking them to report on both their current and past commands. We find that females across all race/ethnicities on average report lower feelings of inclusion and rate commands lower on Core Command Inclusion Competencies than their male counterparts. This gender difference is stronger for sea versus shore commands. Participants also answered open-ended questions about the competencies that they believed were most important for promoting D&I in the fleet. "Inclusive leadership" emerged as a dominant theme; in particular, participants felt most included in commands where leadership valued their perspectives and ideas and where Sailors felt heard on a day-in, day-out basis.N1 - Manpower, Personnel, Training & EducationThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

    The (co-)occurrence of problematic video gaming, substance use, and psychosocial problems in adolescents

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    Aims. The current study explored the nature of problematic (addictive) video gaming and the association with game type, psychosocial health, and substance use. Methods. Data were collected using a paper and pencil survey in the classroom setting. Three samples were aggregated to achieve a total sample of 8478 unique adolescents. Scales included measures of game use, game type, the Video game Addiction Test (VAT), depressive mood, negative self-esteem, loneliness, social anxiety, education performance, and use of cannabis, alcohol and nicotine (smoking). Results. Findings confirmed problematic gaming is most common amongst adolescent gamers who play multiplayer online games. Boys (60%) were more likely to play online games than girls (14%) and problematic gamers were more likely to be boys (5%) than girls (1%). High problematic gamers showed higher scores on depressive mood, loneliness, social anxiety, negative self-esteem, and self-reported lower school performance. Nicotine, alcohol, and cannabis using boys were almost twice more likely to report high PVG than non-users. Conclusions. It appears that online gaming in general is not necessarily associated with problems. However, problematic gamers do seem to play online games more often, and a small subgroup of gamers – specifically boys – showed lower psychosocial functioning and lower grades. Moreover, associations with alcohol, nicotine, and cannabis use are found. It would appear that problematic gaming is an undesirable problem for a small subgroup of gamers. The findings encourage further exploration of the role of psychoactive substance use in problematic gaming

    Reconciling disparate prevalence rates of PTSD in large samples of US male Vietnam veterans and their controls

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    BACKGROUND: Two large independent studies funded by the US government have assessed the impact of the Vietnam War on the prevalence of PTSD in US veterans. The National Vietnam Veterans Readjustment Study (NVVRS) estimated the current PTSD prevalence to be 15.2% while the Vietnam Experience Study (VES) estimated the prevalence to be 2.2%. We compared alternative criteria for estimating the prevalence of PTSD using the NVVRS and VES public use data sets collected more than 10 years after the United States withdrew troops from Vietnam. METHODS: We applied uniform diagnostic procedures to the male veterans from the NVVRS and VES to estimate PTSD prevalences based on varying criteria including one-month and lifetime prevalence estimates, combat and non-combat prevalence estimates, and prevalence estimates using both single and multiple indicator models. RESULTS: Using a narrow and specific set of criteria, we derived current prevalence estimates for combat-related PTSD of 2.5% and 2.9% for the VES and the NVVRS, respectively. Using a more broad and sensitive set of criteria, we derived current prevalence estimates for combat-related PTSD of 12.2% and 15.8% for the VES and NVVRS, respectively. CONCLUSION: When comparable methods were applied to available data we reconciled disparate results and estimated similar current prevalences for both narrow and broad definitions of combat-related diagnoses of PTSD

    A follow up study on the efficacy of metadoxine in the treatment of alcohol dependence

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    BACKGROUND: We carried out a three months follow-up study on the efficacy of metadoxine in a cohort of alcoholics admitted to the Alcohol misuse Long-term Treatment (ALT) Unit – University of Pisa (Italy). We analyzed the clinical data, psychometric tests and blood tests of 160 alcoholics on admission and after 3 months of treatment. We compared 58 pts treated with metadoxine (MET) with 102 pts who did not receive (NULL) any drug as an adjunct to the psycho-educational interventions provided by the ALT Unit. RESULTS: At follow-up, the patients in treatment with metadoxine showed a significant improvement in the rate of complete abstinence (44.8% vs. 21.6%; chi square: 8.45, df = 1, p < 0.0037). Furthermore, the number of drop-outs at three months of treatment was also significantly lower in the MET than in the NULL group (17% vs. 57%; chi square of 23.22, df = 1, p < 0.001). CONCLUSION: Our findings support the use of metadoxine in the management of alcohol dependence. However, randomized clinical trials are necessary to confirm and replicate them. This study raises the importance of identifying new pharmacological compounds effective on the outcome of alcoholism in order to help patients to best adhere to treatment programs and to prevent the development of mental and physical complications due to chronic and heavy use of alcohol
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