Oviposition markers in Callosobruchus maculatus F. and Callosobruchus rhodesianus pic. (coleoptera,bruchidae): Assymmetry of interspecific responses

The bean weevils Callosobruchus maculatus (F.) and C. rhodesianus (Pic.) both laid fewer eggs on previously infested adzuki beans than on fresh beans, even after eggs were removed. A variety of experimental treatments demonstrated the existence of an oviposition marker with ether soluble components. Callosobruchus rhodesianus was inhibited from ovipositing by the C. maculatus marker, but not vice versa.     

Responses of pikas (Ochotona princeps,Lagomorpha) to naturally occurring terrestrial predators

Summary The responses of individually marked pikas (Ochotona princeps) to terrestrial predators were investigated in 1980 and 1981 in the Rocky Mountains of Colorado. Pikas uttered short call vocalizations in a variety of contexts: preceding or following an individual's movement, and in response to conspecifics, other nonpredaceous mammals and predators. Adult pikas apparently discriminated contexts in which predators were present by short calling more frequently and for longer duration compared with calling in nonpredator contexts. Short calls uttered by juveniles were similar in all contexts.Adults responded differently to two types of terrestrial predators: weasels and pine martens. Pikas called less frequently in response to weasels than to martens and avoided weasels more often than martens. They delayed the initiation of calling following the first sighting of a weasel more often than to martens. Weasels were determined to be more effective predators of pikas than martens, and these asymmetries in behavior and alarm vocalizations may indicate that responses reduce an individual's risk of predaton by weasels.Both male and female pikas called in response to predators, and residents called more often than nonresidents. The possible function of predator-related vocalization in pikas is discussed. It is suggested that calls to predators may function to warn local residents, which in pikas are usually closely related.     

National estimates of U.S. residential fire-related injuries: An improved procedure

This study compared fire-related injuries from two ongoing data systems to determine how to combine them to provide improved estimates of U.S. residential fire-related injuries. National estimates and characteristics of patients treated in hospital emergency rooms for fire-related injuries were compared with injuries in a database of fires attended by the fire service. National estimates, age, and diagnosis distributions of injuries seen by both a hospital and the fire service were very similar in the two systems, indicating that the systems overlapped for this segment of injuries. Each system also contained a segment of fire-related injuries that was not included in the other. Combining the overlapping segment of injuries with segments that did not overlap resulted in an estimate of 45,000–47,000 U.S. fire-related injuries, the most com-prehensive estimate of U.S. residential fire-related injuries available to date.     

ARE WE READY FOR A CLOSED SYSTEM OF WATER SUPPLY TREATMENT,AND REUSE - TECHNOLOGY VS. PSYCHOLOGY?1

ABSTRACT: Up to date there are still not many instances that can be found on the practice of a totally closed system of water supply, treatment, and reuse. In the United States, this is partly because the Public Health Service has discouraged such a practice. However, are there sound scientific reasons to support such a decision or is it purely a matter of psychological reason? Are the treatment technologies available today able to achieve the integrated closed system at a reasonable cost, yet without risking the public health? Are there some extra precautions that must be taken in practicing the direct reuse for the drinking purpose? These questions are discussed in this article. Current available technologies for advanced waste treatment are briefly reviewed and the treated effluent qualities obtained by the authors and others are used as a focal point of discussion on the feasibility of practicing the closed system. For this purpose, the treated effluent qualities are compared to the “Ranges of Promulgated Standards for Raw Water Sources of Domestic Water Supply” which have been used by the Public Health Service and several state regulatory agencies.     

Feeding frequency and parental division of labour in the double-brooded great tit Parus major

Summary We studied the relative contribution of each sex and total effort expended in feeding nestlings in the great tit Parus major in relation to artificially altered brood size. A recent model suggests that feeding frequency should reflect the optimal trade-off between parental and fledgling survival, the former being negatively, the latter positively, influenced by high feeding frequencies. In both sexes weight loss was linearly related to feeding frequency. Since fledgling survival increases with nestling weight, the conditions of this model are fulfilled. However, in contrast to the predictions of the model, the total feeding frequency for both sexes combined did not differ between control and enlarged broods, but was lower for reduced ones. This outcome was not the result of a physiologically related inability of the parents to increase their delivery rate. Instead, we suggest that parents with enlarged broods could not find sufficient amounts of prey large enough to be economically worth transporting to the nest. Differences in brood-provisioning rates between the sexes may arise because costs and benefits of feeding nestlings may differ. Females lost more weight than males during the nesting period, but maintained a relatively higher weight during the incubation period. The relationship between weight loss and feeding frequency was similar for both sexes. Male and female brood-feeding frequency was related to brood size in a similar way. This is discussed in light of the great tit's mating system and the fact that the great tit is facultatively double-brooded.     

Assessment and prediction of the impacts of the Ok Tedi copper mine on fish catches in the Fly River system,Papua New Guinea

The Ok Tedi copper mine discharges overburden and ore residues into the Ok Tedi, a tributary of the Fly River. These discharges result in elevated suspended solids and dissolved and particulate associated copper. Analyses of covariance were performed to establish statistical model of the relationships between the mine discharges and fish catches between 1983 and 1988. These models were then extrapolated to predict the affects of future mine discharges on fish catches. The models predicted that if the observed effects were caused by particulate associated copper, the period of greatest impact will be between 1989 and 1993, following which catches should be close to 1988 levels for the remainder of mine life. Some additional catches not included in the data set used to derive the models were found to fit the model predictions well. As the predicted period of greatest impact is short and most species reproduce away from the river channel, the ability of the fish communities to undergo partial recovery after 1991 should be maintained.     

Price Determination and Efficiency in the Market for South Platte Basin Ditch Company Shares

Water scarcity presents an obstacle to economic development in the western United States. Water rights markets help improve water allocation, allowing states to derive the highest economic benefit from available resources, and supporting new uses and economic development. However, the implicit (marginal) prices of water rights attributes are uncertain. To address this problem, we apply econometric analysis to a unique dataset to estimate the implicit values that market participants place on the attributes of shares of ditch company water rights in Colorado's South Platte River Basin. Our analysis demonstrates that ditch company share buyers value proximity of water diversion, reliability of water deliveries, and temporal flexibility of water use. To assess reliability we introduce the use of the coefficient of variation to capture, in one variable, the randomness of supply from ditch company shares that are not a single water right, but a portfolio of rights with different appropriation dates. Finally, we test and correct for spatial autocorrelation for the first time in a study of water market prices.     

FATE OF NITROGEN AND PHOSPHORUS ENTERING A GULF COAST FRESHWATER LAKE: A CASE STUDY1

ABSTRACT: Nitrogen and P fluxes, transformations and water quality functions of Lake Verret (a coastal Louisiana freshwater lake), were quantified. Ortho-P, total-P, NH₄⁺-N NO₃ -N and TKN in surface water collected from streams feeding Lake Verret averaged 104, 340, 59, 185, and 1,060 mg 1^?1, respectively. Lake Verret surface water concentrations of ortho-P, total-P, NH⁺-N, NO₃^?_-N and TKN averaged 66, 191, 36, 66, and 1,292 μg 1^?1. The higher N and P concentrations were located in areas of the lake receiving drainage. Nitrification and denitrification processes were significant in removing appreciable inorganic N from the system. In situ denitrification rates determined from acetylene inhibition techniques show the lake removes 560 mg N m^?2 yr^?1. Laboratory investigations using sediment receiving 450 μg NH⁺₄-N (N-15 labeled) showed that the lake has the potential to remove up to 12.8 g N m^?2 yr^?1. Equilibrium studies of P exchanges between the sediment and water column established the potential or adsorption capacity of bottom sediment in removing P from the overlying water. Lake Verret sediment was found to adsorb P from the water column at concentrations above 50 μg P 1^?1 and the adsorption rates were as great as 300 μg P cm^?2 day^?1 Using the ¹³⁷C s dating techniques, approximately 18 g N m^?2 yr^?1 and 1.2 g P m^?2 yr^?1 were removed from the system via sedimentation. Presently elevated nutrient levels are found only in the upper reaches of the lake receiving nutrient input from runoff from streams draining adjacent agricultural areas. Nitrification, denitrification, and adsorption processes at the sediment water interface over a relatively short distance reduces the N and P levels in the water column. However, if the lake receives additional nutrient loading, elevated levels will likely cover a larger portion of the lake, further reducing water quality in the lake.     

Alignment of the Lumbar Vertebrae in a Driving Posture

The purpose of this study was to define the anatomical arrangement of the lumbar spine in the mid-body sagittal plane of a human volunteer while in three postures: a driving posture; full flexion; and full extension. Radiographic images of the lumbar spine were made of a 33-year old 50th percentile male subject seated in a comfortable driving posture. Additional radiographs were made of the lumbar spine while the subject was postured in full voluntary flexion, and full voluntary extension. Anterior and posterior mid-sagittal vertebral endplate positions were plotted on an x-y coordinate system for each posture. Anterior and posterior disk thicknesses, and the positions of the centers of each vertebra were numerically determined using information from the plots. Disk thicknesses were then graphed and comparisons made for each posture. The arrangements of the centers of vertebrae were graphed and compared for the three different postures. The arrangement of the lumbar vertebrae tended toward that of full voluntary flexion while the subject was in a normal driving posture. Anterior disk thickness was a sensitive indicator of posture, while posterior disk thickness was not. While in a driving posture, the lower back approximated a straight-line that was nearly parallel to the seat back axis. The observations support those of an earlier study. Since soft tissue spinal elements can only be damaged by applying tensile forces in excess of their tolerance, the anterior elements of the lumbar spine would not be directly threatened in low velocity frontal collisions, since anterior elements would be in relative compression. Tension injury to the anterior structures as a result of a rear-end collision would first require reversing the preimpact conditions imposed by the normal driving posture. Tension injury to the posterior spinal elements resulting from low velocity rear-end collisions would be unlikely since axial compression loading would also diminish tension stress in posterior soft tissue structures. Any compression injury to posterior elements resulting from rear-end collisions would first require reversing the pre-impact conditions imposed by the normal driving posture.