Factors influencing movement probabilities of big brown bats (Eptesicus fuscus) in buildings.

We investigated movements of female big brown bats (Eptesicus fuscus) roosting in maternity colonies in buildings in Fort Collins, Colorado (USA), during the summers of 2002, 2003, and 2005. This behavior can be of public health concern where bats that may carry diseases (e.g., rabies) move among buildings occupied by people. We used passive integrated transponders (PIT tags) to mark individual bats and hoop PIT readers at emergence points to passively monitor the use of building roosts by marked adult females on a daily basis during the lactation phase of reproduction. Multi-strata models were used to examine movements among roosts in relation to ambient temperatures and ectoparasite loads. Our results suggest that high ambient temperatures influence movements. Numbers of mites (Steatonyssus occidentalis) did not appear to influence movements of female bats among building roosts. In an urban landscape, periods with unusually hot conditions are accompanied by shifting of bats to different buildings or segments of buildings, and this behavior may increase the potential for contact with people in settings where, in comparison to their more regularly used buildings, the bats may be more likely to be of public concern as nuisances or health risks.     

Single-laboratory evaluation and modification of U.S. EPA methods 7470 and 7471 for the determination of mercury in aqueous and solid hazardous wastes

The current U.S. Environmental Protection Agency (U.S. EPA) protocols for mercury determinations in aqueous and solid waste samples (SW-846 Methods 7470 and 7471) using recirculating cold-vapor atomic absorption spectrometry (CV-AAS) have been evaluated. The U.S. EPA methods are not sufficiently flexible to permit special quality control (QC) measures, have limited detectability for low-level mercury concentrations, and are plagued by spectral interferences caused by the nonspecific absorption of primary mercury radiation by volatile organic vapors. The U.S. EPA protocols have been modified in a single-laboratory study to facilitate additional QC measures, to enhance detectability for low-level mercury concentrations, and to eliminate nonspecific vapor absorption interferences. Volumetric manipulations for additional QC measures, if required, are facilitated by performing the sample digestions in Erlenmeyer flasks rather than in the current Biochemical Oxygen Demand (BOD) reduction-aeration bottles. Typical manipulations for additional QC measures that are now feasible include dilution of concentrated samples and multiple aliquot sampling for post-digestion spike and replicate analyses. Instrument detectability is improved 10-fold by using a gas sparging bottle as a dedicated reduction-aeration vessel and a silver wool-amalgamation CV-AAS system operated in an open configuration. The on-line amalgamation/thermal desorption process of the modified CV-AAS system eliminates interfering water and organic matrix vapors prior to the mercury absorption measurement. Good accuracy and precision have been obtained with the amalgamation CV-AAS system for the analyses of four reference sediment materials. The amalgamation CV-AAS measurements on the reference sediment digests have been successfully performed at absolute mercury concentration levels that are only 1 to 4 times above the instrumental detection limit of the U.S. EPA recirculating CV-AAS method.     

Noise susceptibility: A comparison of two naval aviator populations

The identification of characteristics of noise-susceptible (S) or noise-resistant (R) individuals is necessary for the development of noise-susceptibility risk profiles. Fifty-six naval aviators, categorized as having either incurred a hearing loss, i.e., hearing threshold levels (HTLs) > 40 dB at 4–8 kHz or retained normal hearing, i.e., HTLs ≤ 25 dB at 125 Hz-8 kHz, after thousands of flight hours were compared along several auditory and non-auditory dimensions. A number of variables occurred differentially in the two groups: Minimal Auditory Intensity Differential (MAID) scores at 2 kHz (p < 0.01) and 4 kHz (p < 0.001); iris pigmentation (blue eyes were over-represented in the S group; p < 0.05); systolic blood pressure (sitting; S group was higher; p < 0.05); calcium, albumin, and LDH levels (higher in the R group; p < 0.05); and present tobacco usage (more S aviators were currently smokers; p < 0.05). The S population also tended (p < 0.10) to exhibit elevated cholesterol and triglyceride levels as well as higher contralateral acoustic reflexes, and to have fewer individuals who had never smoked. Although no classic profile of the S or R individual definitely emerged, results suggested that at least one measurement device (MAID test) may serve as an “early warning” of imminent noise-induced damage. Further research, however, is required to test this possibility.     

Dispersion of 222Rn from two New Zealand geothermal power plants

The dispersion of ²²²Rn from emitted waste gases at Wairakei geothermal power station, New Zealand, is modelled. It is concluded that resulting concentrations in the nearby township of Taupo will never exceed the maximum permissible in any meteorological situation. The greatest possible accumulation is calculated to be less than one eighth of the normal background radon concentration. A more realistic set of assumptions predicts long-term mean concentrations about 4% of background levels. A new geothermal power station, Ohaaki, a factor of three times more distant, is calculated to produce ten times lower concentrations than Wairakei. Measurements using a few passive solid-state radon detectors show that the natural variation of radon concentrations greatly exceeds any calculated contribution from either geothermal station; hence, much of the radon is probably due to more local minor sources. Local sources have increased due to draw-off of ground water by the Wairakei station. Thus, there could be some indirect contribution to radon concentrations by its operation. The measured six-month integrated mean radon concentration at Taupo is a significant fraction of the maximum permissible concentration. It seems likely that natural sources alone may lead to levels in air which are above the maximum when temperature inversion exists. It is concluded that these two geothermal power plants are unlikely to produce concentrations of radon hazardous to the population or to plant workers.     

Traffic noise, work noise and cardiovascular risk factors: The Caerphilly and Speedwell collaborative heart disease studies

As part of two large heart surveys, associations between traffic noise exposure and cardiovascular risk factors were studied. The Caerphilly sample (small town, total sample) consisted of 2512 men aged 45 to 59 years and the Speedwell sample (suburb of a major city, random sample) of 2030 men of same age group. Both studies have a prospective design; cross-sectional results are presented here. Acoustic measurements were carried out in both areas. Among the possible risk factors for ischaemic heart disease studied were blood pressure, blood coagulation, blood lipids and other biochemical factors. Statistically significant noise effects were detected for systolic blood pressure, total cholesterol, HDL cholesterol, total triglycerides, blood viscosity, platelet count and glucose level, although not all of these were consistent with noise being a risk factor for heart disease. In a subsample, the additional influence of work noise as determined by noise dosimetry was studied in 255 men, taking the use of ear protection into account. The associations between traffic noise and risk factors were more pronounced in men who also were exposed to high work noise levels.     

Genetic Polymorphisms and Their Relationships with Inbreeding and Breed Structure in Rare British Sheep: The Portland, Manx Loghtan, and Hebridean

Abstract: 320 sheep of three rare British breeds were typed for blood group and biochemical polymorphism. Genetic distance was least between the Manx Loghtan and Hebridean (D = 0.1241, supporting historical evidence of a close relationship between the breeds. Distances to the Portland breed were 0.144 and 0.186, respectively. The claim that the Portland is related to the Dorset Horn was substantiated by the fact that both breeds possess the i blood group allele. Pedigree analysis showed that most rare or unusual alleles in the three bee could be traced to particular ancestors, which had been accepted for registration as foundation stocks, i. e., there was little evidence of genetic introgression from other breeh. Highly inbred sheep showed the predicted lack of heterozygosity.
When these sheep were first registered (1973), foundation stocks were defined comprising animals of correct breed type. Today, the pedigree of each sheep reveals the percentages of its ancestry attributable to each foundation stock Sheep were classified according to these percentages into subgroups, each of which, therefore corresponds to a strain within the breed Genetic distances were calculated among these subgroups within each breed For the Portland these distances were rather large (D up to 0.069), but distances were rather small for the other two breeds (D up to 0.027). The Manx Loghtan and Hebridean breeds are therefore relatively homogeneous while the genetic distances among Portland subgroups reveal the genetic consequences of the reproductive isolation of certain important flocks