Leaching of 2,4-D and dicamba from home lawns

Leaching of the broadleaf herbicides 2,4-D and dicamba from home lawns was monitored with ceramic extraction plates placed at a 0.2 m depth beneath undisturbed sod. The site was located on a Merrimac sandy loam. Four treatments, consisting of two rates of herbicide applications coupled with two irrigation regimes. were evaluated on 12 plots. The low herbicide rate consisted of 1.1 and 0.1 kg ha^?1 yr^?1 of 2,4-D and dicamba, respectively. The high rate used was 3.3 and 0.33 kg ha^?1 yr^?1 of 2,4-D and dicamba applied in three equal applications. Irrigation treatments were (1) minimal irrigation to avoid drought stress and percolation from the root zone and (2) overwatering at 37.5 mm week^?1. Geometric mean concentra tions of 2,4-D ranged from 0.55 to 0.87 μg L^?1 compared to 0.26 to 0.55 μg L^?1 for dicamba. The low application-minimum irrigation treatment generated significantly higher concentrations than the other treatments for both herbicides. The low concentrations observed for both herbicides suggest that excellent degradation conditions exist in the root zone of turfgrass during the summer months when application occurs.     

Assessment of Water Quality in Association with Land use in the Tillamook Bay Watershed, Oregon, USA

The water quality in tributaries to Tillamook Bay, Oregon, frequently exceeds standards for fecal coliform bacteria (FCB) and temperature. FCB inputs to the bay have forced periodic closure of the oyster shellfish industry. In addition, impaired water quality may be contributing to reduced salmonid populations in the bay and its tributaries through reduction in the quality of the habitat. Because of these concerns, the Tillamook Bay National Estuary Project (TBNEP) conducted several characterization studies and a long-term water quality monitoring program for the tributary rivers. This paper summarizes data collected to date within these efforts, including storm-based data on FCB and total suspended solids (TSS), and bimonthly data on nutrient concentrations in selected rivers. Monitoring data from 1996 to 2002 are summarized. Results for FCB and TSS are reported by storm, which are classified according to season and precipitation patterns in order to minimize intra-annual variability. There are not indications of large changes in water quality throughout the period of record, but it is too early in the program for trends analysis. Storms that exhibited the highest FCB concentrations tended to be those that occurred during fall and/or those that were preceded by relatively dry conditions and included high rainfall intensity. Implementation of storm-based monitoring and classification of storms according to season effectively reduces the large variability inherent in the FCB monitoring data, thereby facilitating future trends analysis. Continued storm-based monitoring of FCB and TSS, and also continued collection of rainfall and river discharge data, will provide the database that will be needed to determine to what extent on-the-ground remediation actions and best management practices (BMPs) within the Tillamook Basin are having their desired effects.     

Long-term impacts of infrequent biosolids applications on chemical and microbial properties of a semi-arid rangeland soil

A plot study was conducted to quantify long-term (>12 years) impacts of a single biosolids application, and short-term impacts (<2 years) of a repeated application, on semi-arid rangeland soil chemical and microbial parameters. In 2003 and 2004, plots which had received 0, 2.5, 5, 10, 21, or 30 Mg biosolids ha⁻¹ once in 1991 (long-term plots), or again in 2002 (short-term plots), were sampled and analyzed for soil chemical parameters, microbial biovolumes, C and N mineralization activities, Biolog EcoPlate substrate utilization potential, and plant productivity and tissue quality. Repeated applications temporarily exacerbated differences in soil chemical properties among treatments, but after 2 years, soil chemistry trends were similar between short-term and long-term plots. Soils which received a repeated application of 21 or 30 Mg biosolids ha⁻¹ had greater bacterial biovolumes and C and N mineralization activities. In long-term plots, mineralization activities were stimulated only at the highest rate. Biosolids-amended soil communities also utilized Biolog substrates more quickly compared to communities from control plots. Plant biomass increased, whereas plant diversity and plant C/N ratio decreased with increasing application rate for both short- and long-term plots. Infrequent biosolids application had positive ecosystem effects in terms of site management objectives, with relatively low extractable metal levels in soil and greater plant biomass and tissue quality despite reduced species richness.     

Translocation of urban Gila Monsters: a problematic conservation tool

The Gila Monster (Heloderma suspectum) is a large, venomous lizard protected throughout its distribution in the southwestern United States and northwestern Mexico. Rapid urban growth in key areas of its range and increased encounters with humans prompted us to investigate translocation as a conservation tool with “nuisance” Gila Monsters. Twenty-five Gila Monsters reported as nuisances by residents in the northeastern Phoenix Metropolitan Area were translocated from 0 to 25,000 m from their point of capture. Subjects (N=18) translocated less than 1000 m returned to their original site of capture within 2-30 days; none of those (N=7) translocated more than 1000 m successfully returned, they exhibited high daily rates of speed, and were deprived the use of familiar refuges. We conclude that small distance translocations within suitable habitats are ineffective in removing Gila Monsters from areas deemed unsuitable. Moreover, individuals moved significantly greater distances are unlikely to remain at a translocation site, and may experience a variety of costs (e.g., predation risk) associated with high rates of movement.     

Disorders of the pharynx.

Pharyngeal disorders are complex and difficult to treat. Disorders that lead to anatomic derangement, such as trauma and neoplasia, can significantly affect the function of this organ. Pharyngeal dysfunction can manifest as dysphagia, persistent palatal displacement, or exercise intolerance. Secondary complications are serious and life threatening and include aspiration pneumonia, weight loss, and death. Pharyngeal disorders that are only recognizable during strenuous exercise are difficult to diagnose and are treated with limited success, even though they are responsible for significant economic losses with performance animals.     

Effects of detomidine on equine oesophageal function as studied by contrast radiography

The effects of sedation with detomidine on oesophageal function were assessed by contrast radiography in 10 healthy adult thoroughbred horses. Barium swallows were monitored by means of image intensification, first without sedation and then after the intravenous administration of detomidine at doses of 10 and 20 micrograms/kg bodyweight. The transit time of contrast agent to the oesophageal hiatus was recorded and each swallow was scored for markers of oesophageal dysfunction. Analysis of the data indicated that there were highly significant dose dependent increases in the transit time, the retention of barium within the longitudinal mucosal folds, and retrograde peristalsis and pooling of contrast agent within the oesophagus at both the thoracic inlet and caudal to the base of the heart. The degree of gastrooesophageal reflux was not affected at either dosage. These changes in oesophageal function were similar to those recorded from cases of grass sickness and indicate that care should be taken in the interpretation of studies of swallowing in animals that have been given detomidine before a radiographic examination.     

Management of 60 cases of diaphragmatic rupture

Sixty cases of diaphragmatic rupture in the dog and cat were reviewed. There was a 90 per cent success rate following surgical repair. There were six deaths; two of these resulted from pulmonary collapse and hydrothorax, two cats from pulmonary oedema, one cat with cardiac arrest and one due to hepatic necrosis. In none of the deaths was the presence or absence of chest drains implicated. Apart from cases of gastric dilation, all animals benefited from 12 to 24 hours cage rest and stabilisation before surgery. Simple anaesthetic and surgical guidelines for the management of diaphragmatic rupture are described.     

MULTICENTRIC LYMPHOMA WITH INTESTINAL INVOLVEMENT IN A DOG

A 5-year-old, male German shepherd dog was evaluated for a 5-week history of vomiting, diarrhea, lethargy, and weight loss. In abdominal radiographs, there was an unusual corrugated appearance within a loop of intestine. Sonographically, this loop also had a similar corrugated appearance with alternating hyperechoic and hypoechoic bands. Lymph nodes within the abdomen and thorax were enlarged, and a thoracic mass was also detected. Ultrasound-guided fine-needle aspirates of the mesenteric lymph nodes were highly suggestive of lymphoma. After postmortem examination, a diagnosis of multicentric lymphoma with involvement of the gastrointestinal tract was made.