A water quality monitoring network design methodology for the selection of critical sampling points: part II.

In order to resolve the spatial component of the design of a water quality monitoring network, a methodology has been developed to identify the critical sampling locations within a watershed. This methodology, called Critical Sampling Points (CSP), focuses on the contaminant total phosphorus (TP), and is applicable to small, predominantly agricultural-forested watersheds. The CSP methodology was translated into a model, called Water Quality Monitoring Station Analysis (WQMSA). It incorporates a geographic information system (GIS) for spatial analysis and data manipulation purposes, a hydrologic/water quality simulation model for estimating TP loads, and an artificial intelligence technology for improved input data representation. The model input data include a number of hydrologic, topographic, soils, vegetative, and land use factors. The model also includes an economic and logistics component. The validity of the CSP methodology was tested on a small experimental Pennsylvanian watershed, for which TP data from a number of single storm events were available for various sampling points within the watershed. A comparison of the ratios of observed to predicted TP loads between sampling points revealed that the model's results were promising.

A water quality monitoring network design methodology for the selection of critical sampling points: Part I.

The principal instrument to temporally and spatially manage water resources is a water quality monitoring network. However, to date in most cases, there is a clear absence of a concise strategy or methodology for designing monitoring networks, especially when deciding upon the placement of sampling stations. Since water quality monitoring networks can be quite costly, it is very important to properly design the monitoring network so that maximum information extraction can be accomplished, which in turn is vital when informing decision-makers. This paper presents the development of a methodology for identifying the critical sampling locations within a watershed. Hence, it embodies the spatial component in the design of a water quality monitoring network by designating the critical stream locations that should ideally be sampled. For illustration purposes, the methodology focuses on a single contaminant, namely total phosphorus, and is applicable to small, upland, predominantly agricultural-forested watersheds. It takes a number of hydrologic, topographic, soils, vegetative, and land use factors into account. In addition, it includes an economic as well as logistical component in order to approximate the number of sampling points required for a given budget and to only consider the logistically accessible stream reaches in the analysis, respectively. The methodology utilizes a geographic information system (GIS), hydrologic simulation model, and fuzzy logic.

The effect of time at which plasma separation occurs on biochemical values in small island flying foxes (Pteropus hypomelanus).

Heparinized blood samples from 15 adult small island flying foxes (Pteropus hypomelanus) were stored at 22 degrees C for 0-, 6-, and 24-hr intervals prior to centrifugation and separation of plasma from erythrocytes. Mean plasma biochemical values of 16 analytes were determined from all samples. Mean values of blood urea nitrogen, creatinine, total protein, albumin, globulin, alkaline phosphatase, alanine transaminase, aspartate transaminase, cholesterol, calcium, sodium, and bilirubin did not change significantly over 24 hr at 22 degrees C. Glucose was decreased at 6 and 24 hr. Potassium and phosphorus increased and chloride decreased, respectively, between 6 and 24 hr.

Spatial and temporal epidemiology of pseudorabies virus infection.

OBJECTIVE: To examine the pattern of pseudorabies virus (PRV) infection in Pennsylvania and identify the area factors associated with herd quarantine status. SAMPLE POPULATION: 123 PRV-quarantined commercial swine herds identified between 1986 and 1993 were selected as cases, and 162 uninfected herds were selected as controls. PROCEDURE: Herd location, demographics, and temporal vaccination and quarantine data for a case-control study were obtained from producer questionnaires and state records, using a database of swine herds from 2 Pennsylvania counties. Any herd that was on quarantine as of Jan 1, 1991, or quarantined subsequent to this date, was defined as a case. A herd was defined as a control if it had never been quarantined for PRV. Controls were group matched to cases by year. Study herds were centered in a circle, or buffer zone, with a 1.61-km (1-mile), 3.22-km (2-mile), or 6.44-km (4-mile) radius, and densities of operation types, quarantined herds, nonquarantined herds, and vaccinated herds in the buffer zone were compared. The analytical outcome was the probability of a herd being quarantined, conditional on the buffer zone density of herds quarantined, herds not quarantined, and herds in which a PRV vaccine was used. These density variables were categorized into high, medium, and low, or just high and low categories. Confounding by year was assessed in the analysis. Analysis was performed, using unconditional logistic regression. RESULTS: Decreased density of PRV-quarantined herds in the study region was associated with reduced risk of a herd becoming quarantined, whereas increased density of nonquarantined, presumably uninfected herds was associated with decreased probability of a herd becoming quarantined. Decreased density of vaccinated herds was associated with increased probability of a herd becoming quarantined. In addition, being a farrow-to-finish study herd was associated with increased probability of becoming quarantined, compared with being a feeder pig producer study herd. CONCLUSIONS: Associations with quarantine status and area densities of vaccinated, nonquarantined, and quarantined herds indicate the importance of area spread in PRV control. These effects are seen most strongly at a 3.22-km (2-mile) radius, but also are seen at a 6.44-km (4-mile) radius.

Spatial and biological characteristics of between-herd transmission of Aujeszky's disease virus.

The eradication of Aujeszky's disease virus (ADV) in Pennsylvania has suffered because the modes of viral transmission between herds are unknown. Our objective was to identify the major risk factors involved in viral transmission by comparing proportions of operation type, density, quarantine level, and vaccination status of neighboring herds for infected case and uninfected control herds. Multivariate analysis demonstrated an elevated risk of infection with local increases in the proportion of finishing floors. A local increase in the proportion of ADV-quarantined herds was shown to be a significant risk factor, as was an increase in the proportion of vaccinating herds. A reduced risk of infection was found with local increases in the number of feeder pig producer operations.

The effect of tourniquets on muscle enzymes during foot and ankle surgery.

The use of lower extremity tourniquets for procedures of the foot and ankle is considered routine in podiatric surgery, yet, lower extremity tourniquets are not benign. Recent publications in the orthopedic and podiatric literature report incidents of rhabdomyolysis with associated myoglobinurea as a consequence of prolonged tourniquet use. An unselected series of 40 patients undergoing a variety of surgical procedures on the foot and ankle with tourniquet control were studied. Preoperative and postoperative laboratory values were used to evaluate the effect of tourniquets on muscle enzymes during podiatric surgery.

[Failure of acupuncture anesthesia. A psychophysical study (author's transl)]. / Der Misserfolg der Akupunktur-Anästhesie. Eine psychophysische Studie

Four volunteers judged eight levels of thermal stimuli induced by a Hardy dolorimeter, varying in intensity from extremely painful to a low level seldom even perceived. Half of the 406 stimuli were applied during acupuncture and half either before the insertion or after removal of the needles. The experimental design minimized or eliminated factors other than the needles themselves; i.e. no medications were given; the subjects were scientists accustomed to objectivity and, on a preceeding day or days, all became experienced in assigning a number (individually chosen) to the sensation produced by the different stimuli. Galvanic skin resistance was also tested. The results did not show any influence of acupuncture on pain perception or galvanic skin resistance.