A Concentric Analysis of the Impact of Urbanization on the Threatened European Tree Frog in an Agricultural Landscape

Abstract:  Pond-breeding amphibians are affected by site-specific factors and regional and landscape-scale patterns of land use. Recent anthropogenic landscape modifications (drainage, agriculture intensification, larger road networks, and increased traffic) affect species by reducing the suitable habitat area and fragmenting remaining populations. Using a robust concentric approach based on permutation tests, we evaluated the impact of recent landscape changes on the presence of the endangered European tree frog ( Hyla arborea ) in wetlands. We analyzed the frequency of 1 traffic and 14 land-use indices at 20 circular ranges (from 100-m up to 2-km radii) around 76 ponds identified in western Switzerland. Urban areas and road surfaces had a strong adverse effect on tree frog presence even at relatively great distances (from 100 m up to 1 km). When traffic measurements were considered instead of road surfaces, the effect increased, suggesting a negative impact due to a vehicle-induced effect. Altogether, our results indicate that urbanization and traffic must be taken into account when pond creation is an option in conservation management plans, as is the case for the European tree frog in western Switzerland. We conclude that our easy-to-use and robust concentric method of analysis can successfully assist managers in identifying potential sites for pond creation, where probability of the presence of tree frogs is maximized.     

Radioactivity in trinitite six decades later

The first nuclear explosion test, named the Trinity test, was conducted on July 16, 1945 near Alamogordo, New Mexico. In the tremendous heat of the explosion, the radioactive debris fused with the local soil into a glassy material named Trinitite. Selected Trinitite samples from ground zero (GZ) of the test site were investigated in detail for radioactivity. The techniques used included alpha spectrometry, high-efficiency gamma-ray spectrometry, and low-background beta counting, following the radiochemistry for selected radionuclides. Specific activities were determined for fission products (90Sr, 137Cs), activation products (60Co, 133Ba, 152Eu, 154Eu, 238Pu, 241Pu), and the remnants of the nuclear fuel (239Pu, 240Pu). Additionally, specific activities of three natural radionuclides (40K, 232Th, 238U) and their progeny were measured. The determined specific activities of radionuclides and their relationships are interpreted in the context of the fission process, chemical behavior of the elements, as well as the nuclear explosion phenomenology.     

1999年委内瑞拉阿维拉山北坡入海型泥石流

委内瑞拉阿维拉山呈东一西走向，北坡濒临加勒比海．１９９９年１２月１６日，阿维拉山北坡２０多条沟谷暴发泥石流，使沿海的城镇、村庄、港口、公路及各种设施遭到毁灭性破坏，造成数万人死亡，直接经济损失超过刀亿美元．泥石流发生在森林植被良好的山区，具低频率和群发性特征，规模大，直接入海．分析这次泥石流灾害，对我国的防灾减灾工作具有启示意义．     

Radionuclide and chemical concentrations in mineral waters at Saratoga Springs, New York

A project to characterize the radionuclide and chemical components in natural spring waters in the vicinity of Saratoga Springs, New York (USA) has been completed. As a result of the measured radionuclide and chemical content, eight springs were labeled as mineral waters, whereas three springs contained very low concentrations of these components. The mineral waters were highly enriched in alkaline and alkaline-earth elements, as well as chloride ions. Three isotopes of radium ((224)Ra, (226)Ra, (228)Ra) were detected in the mineral waters and reached concentrations of 1, 20, and 2 Bq/L, respectively. Overall, the (226)Ra isotope constituted about 80% of the total radioactivity measured in the water samples. Dissolved uranium concentrations in the mineral waters were very low (mean approximately 50 mBq/L).     

Assessing radon concentrations in areas with few measurements

The New York State Department of Health has estimated and mappedradon concentrations for every town and city in the State. Sincefor many towns there are few indoor radon measurements, the radonestimates for these towns were determined using correlations to surficial geology. A project was conducted to target towns for additional measurements that currently have few data but, based on the surficial geology of the town, are estimated to have elevated levels of indoor radon. The objective of the project wasto obtain at least 30 additional measurements for the targeted towns and to compare the measurement results with the estimates based on geology. The study completed 1606 radon measurements from 9080 detector applications mailed to home owners in 94 underserved towns spread throughout the State. Of the 1115 basement measurements, 43% exceeded 148 Bq m^-3, with a maximum of 6900 Bq m^-3. Three homes measured in one town hadradon concentrations above 2900 Bq m^-3. Of the 491 living-area measurements, 19% exceeded 148 Bq m^-3, with a maximum of 2700 Bq m^-3. About 60% and 86% of measurementresults were within one standard deviation and a factor of two,respectively, of estimated concentrations. Results indicate thatregardless of the magnitude of radon potential, the estimates arein good agreement with measured concentrations.     

Elemental analysis of total suspended particulate matter in the ambient air of Baghdad

Samples of atmospheric particulate matter obtained from representative areas of the city of Baghdad were collected on glass fiber filters using a high-volume sampler. Atomic absorption techniques were used to analyze the total suspended particulates (TSP) for the following trace metals; Fe, Cu, Zn, Pb, Mn, Cr, Cd, Co, and Hg. Sulfates were measured by turbidemetric method. Ion-selective electrodes was used for chloride analysis. It is concluded that the major components of TSP in the ambient air of Baghdad consist of mineral dust. Pb and Cd gave high enrichment factor values, which implies enrichment of these two metals from anthropogenic sources. High enrichment factors were also obtained for Zn and Cu. It is also concluded that in this arid area, the black smoke reflectance method is not suitable for measuring total suspended matter gravimetrically.     

Impact of education on the attitudes of college students toward biotechnology

An interdisciplinary course was designed as an introduction to the applications of, and the socio-economic issues associated with, biotechnology. College students enrolled in the course were surveyed prior to the first formal lecture, and again upon completion of the course. Assessment was made of the impact of the educational materials on the attitudes and perceptions of the students toward the applications of biotechnology to agriculture. Data were collected for the first three semesters in which the course was offered. Answers to survey questions were analyzed on a before and after basis. It was found that students were very accepting of biotechnology prior to taking the course, despite a generally low level of exposure to this type of technology. The course was effective in increasing the knowledge base of the students, but not as effective in allaying their perceptions of risks associated with biotechnology.     

稻田土壤种子库研究进展

土壤种子库是指存在于土壤表面和土壤中全部存活种子的总和。稻田土壤种子库是地上杂草产生的根本来源。我国是一个水稻种植大国,目前关于稻田土壤种子库的研究还不够全面和深入。研究稻田土壤种子库对于防治稻田草害具有重要指导意义,同时也是种子库研究领域的一个重要补充。取样方法和取样时间是研究土壤种子库的关键所在。而萌发法是最常见的判定方法。关于稻田土壤种子库大小的结论相差很大,从103~105 m-2不等。稻田土壤种子库中的杂草主要有19科55种,一般的稻田可检出10科或20种左右。种子的垂直分布格局主要受耕作强度的影响。70%~80%甚至更多的杂草种子分布在0~10 cm。稻田土壤种子库由于萌发、捕食、衰老和种子散布等原因具有季节动态。轮作制度、耕作方式、不同施肥处理以及除草方式等对稻田土壤种子库有重要影响。连续多年的田间管理会使种子库的大小、分布和物种组成产生年际变化。目前,需要加强长期定位研究,扩大研究区域和研究内容,重点研究杂草种子的休眠萌发机制和种子命运研究,为杂草治理提供更准确的信息。     

Airborne 131I at a background monitoring site

As part of an environmental surveillance program, measurements of 131I in samples of atmospheric aerosols were determined in week-long collection periods at 0.3 km and 1.5 km from a municipal-sewage sludge incinerator located in Albany, New York. During an 11-month period when the sampler was temporarily located near the incinerator, sampling canisters of activated charcoal nearly always contained detectable airborne 131I activity (range of 0.1-6.0 mBq m(-3)). In contrast, remote concentrations where the sample was normally located were near or below analytical detection limits, both before and after the 11-month relocation. Activities of wet and dry fallout at both locations were below detection limits. The source of 131I in the aerosols associated with the sewage sludge was likely excreta from patients following medical treatments at local hospitals.     

Performance of a commercial radon-in-water measurement kit

Methods currently approved for the measurement of radon ((222)Rn) in water in New York State are liquid scintillation counting and emanation into alpha-scintillation cells. A passive system using an electret ion chamber (EIC) was evaluated as an alternative for the measurement of radon in water. Over 130 water samples from a community water supply containing 32BqL(-1) and 30 standards containing 686BqL(-1) were measured using the EIC method over 1- to 4-day exposure times. For comparison, identical samples were measured using liquid scintillation counting. Results of duplicate samples were typically within 5% for liquid scintillation counting and within 10% for the EIC. With respect to accuracy, the EIC produced results that were consistently low by 11-15%.