Since Delaware's coastal bays have been highly eutrophied for at least twenty years and Maryland's coastal bays are not nutrient stressed, dominance of the fish community in Delaware's coastal bays by Fundulus sp. may be an indicator of nutrient stress. Maryland's coastal bays are menhaden, spot, and anchovy dominated. The dominance of Fundulus sp. in a nutrient-stressed system relates to the hardy nature of these fishes, especially in low-oxygen conditions. Submerged aquatic vegetation as seagrasses (SAV) has been absent from the highly nutrient-stressed Delaware coastal bays for about twenty-five years. In contrast, SAV is still found in Maryland's coastal bays. The loss of SAV as a habitat for young fish may also be contributing to the apparent species shift in Delaware's coastal bays.Indian River Bay is less hospitable to macroalgae (seaweeds) than Rehoboth Bay. Dominance of Ulva in Indian River Bay reflects its tolerance to varying salinities, higher nutrient levels, and increased turbidities, and indicates a stressed system. The total volume of macroalgae, especially in Rehoboth Bay, tends to follow the seasonal cycle for phosphorus.Based on an assessment of the ecological condition of the Delaware and Maryland coastal bays conducted by EMAP in 1993 and other related studies, the author offers a conceptual framework for Delaware's inland bays environmental classification, considering the water quality parameters of turbidity, TSS, Chla, DIN, DIP, and O2 as they relate to presence of SAV, seaweed abundance and diversity, benthic invertebrate diversity, and fish sensitivity to low oxygen. 相似文献
The ventilation mechanism of Rn gas in underground environments is considered. Ventilation plays an important role in influencing the variability (harmonics) of Rn gas in the porous space below the earth's surface. We propose a new physical-environmental model of relating Rn gas concentrations to air temperature variations at the earth's surface. Applicability of this model was tested after searching for Rn gas indicators of geodynamic processes in two underground tunnels in central and southern Israel. The theoretical estimation of Rn gas concentrations shows a good agreement with the observed values. We demonstrate the possibility of Rn gas anomalies being caused by atmospheric temperature variations and the necessity to take these effects into account when investigating geodynamic processes. 相似文献
ABSTRACT .A summary is presented of remarks made at a conference held at Louisiana Tech University on the possibility of diverting some of the Mississippi River water to Texas and New Mexico. The Texas Water Plan which has initiated the diversion possibility is discussed and particular reference is made to the activities of the federal and state agencies directly responsible for determining various aspects of the diversion study. These agencies include the Texas Water Development Board, Texas Water Quality Board, Louisiana Department of Public Works, State Engineer's Office of New Mexico, Mississippi River Commission, and the Bureau of Reclamation. 相似文献
ABSTRACT: The U.S. Geological Survey has collected flood data for small, natural streams at many sites throughout Georgia during the past 20 years. Flood-frequency relations were developed for these data using four methods: (1) observed (log-Pearson Type HI analysis) data, (2) rainfall-runoff model, (3) regional regression equations, and (4) map-model combination. The results of the latter three methods were compared to the analyses of the observed data in order to quantify the differences in the methods and determine if the differences are statistically significant. Comparison of regression-estimates with observed discharges for sites having 20 years (1966 to 1985) and 10 years (1976 to 1985) of record at different sites of annual peak record indicate that the regression-estimates are not significantly different from the observed data. Comparison of rainfall-runoff-model simulated estimates with observed discharges for sites having 10 years and 20 years of annual peak record indicated that the model-simulated estimates are significantly and not significantly different, respectively. The biasedness probably is due to a “loss of variance” in the averaging procedures used within the model and the short length of record as indicated in the 10 and 20 years of record. The comparison of map-model simulated estimates with observed discharges for sites having 20 years of annual-peak runoff indicate that the simulated estimates are not significantly different. Comparison of “improved” map-model simulated estimates with observed discharges for sites having 20 years of annual-peak runoff data indicate that the simulated estimates are different. The average adjustment factor suggested by Lichty and Liscum to calculate the “improved” map-model overestimates in Georgia by an average of 20 percent for three recurrence intervals analyzed. 相似文献
A 25-item scoring instrument was developed to measure perceptions of the extent to which performance appraisals are affected by organizational politics. The survey was administered to 157 francophone managers. A factor analysis revealed that the perceptions of the extent to which political considerations affect the appraisal an employee receives can be sensibly interpreted in terms of a single general factor. The internal consistency and test-retest reliability of the instrument was high. Moderate support was found for the instrument's convergent and discriminant validity. 相似文献
Objective: Road traffic accidents (RTAs) are the first cause of abdominopelvic injuries (APIs). The objective of this study was to describe the characteristics and severity of APIs due to traffic accidents in a large French trauma registry and to identify risk factors for API.
Methods: All victims from the French Rhône registry of victims of RTAs were analyzed from 1996 to 2013. This registry contained data that were issued over a 20-year period from 245 medical departments, from prehospital care until re-adaptation, and forensic medicine departments. All APIs, defined as an injury between the diaphragm and the pelvic bone, were extracted and studied.
Results: Among 162,695 victims, 10,165 had an API (6.7%). Accidents frequently involved young men and 2 cars. Mean Injury Severity Score (ISS) was 8.7. Mortality rate was 5.6%. Soft tissue injuries largely predominated (n = 6,388; 54.4% of patients). Overall, 2,322 victims had a pelvic bone injury. Internal abdominal organs were involved in 2,425 patients; the most frequent were the spleen, liver, and kidney. Wearing of the seat belt appeared to be a significant protective factor in API, including serious injuries. A partial analysis over the past 2 years among the most severe patients hospitalized in the intensive care unit indicated that nonoperative management was carried out in two thirds of the wounded. In uni- or multivariate analysis, sex, age, type of user, antagonist, time of occurrence, associated severe lesions, or wearing of the seat belt were statistically associated with the occurrence of API, highlighting a more dangerous user profile.
Conclusions: Abdominopelvic injuries concern a minority of road traffic injuries, but they are responsible for significant mortality. Large solid organs are the most frequently affected. Women drivers wearing a seat belt and driving in town during the day appear to be more protected against API. 相似文献
How well does the general public understand the concept of urban resilience? We address this question via an online survey of 500+ citizens living in three large Australian cities (Sydney, Melbourne and Perth). The majority of respondents claim not to know what urban resilience means. Of the remaining respondents, understanding ranges from poor to sophisticated. To circumvent this stated lack of understanding, we cast the concept of urban resilience into a more familiar framework consisting of risk and ability to cope with threats. This allows us to assess perceptions about what may challenge the resilience of Australian cities. Two concerns clearly emerge: (1) violence and social unrest and (2) environmental threats. Analysing a number of constructs from the social psychology literature reveals that these two concerns hold different cognitive signatures, whose understanding may facilitate discussion and communication within a public engagement process. 相似文献
Environmental Science and Pollution Research - Risks of heavy metal exposure from contaminated indoor dust constitute a major threat to human health. In this paper, heavy metals in deposited indoor... 相似文献