Downstream Warming and Headwater Acidity May Diminish Coldwater Habitat in Southern Appalachian Mountain Streams.

Stream-dwelling species in the U.S. southern Appalachian Mountains region are particularly vulnerable to climate change and acidification. The objectives of this study were to quantify the spatial extent of contemporary suitable habitat for acid- and thermally sensitive aquatic species and to forecast future habitat loss resulting from expected temperature increases on national forest lands in the southern Appalachian Mountain region. The goal of this study was to help watershed managers identify and assess stream reaches that are potentially vulnerable to warming, acidification, or both. To our knowledge, these results represent the first regional assessment of aquatic habitat suitability with respect to the combined effects of stream water temperature and acid-base status in the United States. Statistical models were developed to predict July mean daily maximum water temperatures and air-water temperature relations to determine potential changes in future stream water temperatures. The length of stream considered suitable habitat for acid- and thermally sensitive species, based on temperature and acid neutralizing capacity thresholds of 20°C and 50 µeq/L, was variable throughout the national forests considered. Stream length displaying temperature above 20°C was generally more than five times greater than the length predicted to have acid neutralizing capacity below 50 µeq/L. It was uncommon for these two stressors to occur within the same stream segment. Results suggested that species' distributional shifts to colder, higher elevation habitats under a warming climate can be constrained by acidification of headwater streams. The approach used in this study can be applied to evaluate climate change impacts to stream water resources in other regions.

Perchlorate content of plant foliage reflects a wide range of species-dependent accumulation but not ozone-induced biosynthesis.

Perchlorate (ClO4(-)) interferes with uptake of iodide in humans. Emission inventories do not explain observed distributions. Ozone (O3) is implicated in the natural origin of ClO4(-), and has increased since pre-industrial times. O3 produces ClO4(-)in vitro from Cl(-), and plant tissues contain Cl(-) and redox reactions. We hypothesize that O3 exposure may induce plant synthesis of ClO4(-). We exposed contrasting crop species to environmentally relevant O3 concentrations. In the absence of O3 exposure, species exhibited a large range of ClO4(-) accumulation but there was no relationship between leaf ClO4(-) and O3, whether expressed as exposure or cumulative flux (dose). Older, senescing leaves accumulated more ClO4(-) than younger leaves. O3 exposed vegetation is not a source of environmental ClO4(-). There was evidence of enhanced ClO4(-) content in the soil surface at the highest O3 exposure, which could be a significant contributor to environmental ClO4(-).

Soil, plant, and terrain effects on natural perchlorate distribution in a desert landscape.

Perchlorate (ClO) is a contaminant that occurs naturally throughout the world, but little is known about its distribution and interactions in terrestrial ecosystems. The objectives of this Amargosa Desert, Nevada study were to determine (i) the local-scale distribution of shallow-soil (0-30 cm) ClO with respect to shrub proximity (far and near) in three geomorphic settings (shoulder slope, footslope, and valley floor); (ii) the importance of soil, plant, and terrain variables on the hillslope-distribution of shallow-soil and creosote bush [ (Sessé & Moc. ex DC.) Coville] ClO; and (iii) atmospheric (wet plus dry, including dust) deposition of ClO in relation to soil and plant reservoirs and cycling. Soil ClO ranged from 0.3 to 5.0 µg kg. Within settings, valley floor ClO was 17× less near shrubs due in part to enhanced leaching, whereas shoulder and footslope values were ∼2× greater near shrubs. Hillslope regression models (soil, = 0.42; leaf, = 0.74) identified topographic and soil effects on ClO deposition, transport, and cycling. Selective plant uptake, bioaccumulation, and soil enrichment were evidenced by leaf ClO concentrations and Cl/ClO molar ratios that were ∼8000× greater and 40× less, respectively, than soil values. Atmospheric deposition ClO flux was 343 mg ha yr, ∼10× that for published southwestern wet-deposition fluxes. Creosote bush canopy ClO (1310 mg ha) was identified as a previously unrecognized but important and active reservoir. Nitrate δO analyses of atmospheric deposition and soil supported the leaf-cycled-ClO input hypothesis. This study provides basic data on ClO distribution and cycling that are pertinent to the assessment of environmental impacts in desert ecosystems and broadly transferable to anthropogenically contaminated systems.

Some notes on an early nineteenth century manuscript medical receipt book.

There are 97 remedies listed, including 11 veterinary ones. These numbers include several that are duplicates. The commonest types of medicament are salves or ointments, of which there are ten, but these ten do not include ointments for specific complaints such as haemorrhoids or scurvy. The most frequently found cures are for the itch (10), rheumatism (5), gravel (4), pain (4), and piles (3), all the others having only one or two entries. They were intended to treat 39 human complaints and 9 animal ones. In addition there were formulae for killing lice, making rat poison, and preparing damson wine! The number of different medicaments that were used in the recipes was relatively small, but more than were to be found in the smaller sizes of domestic medicine cabinet. In 1820 Reece's Traveller's Dispensary that was flat and would fit in the pocket of a carriage, only contained ten drugs plus court plaster, lint, scales and weights with a book of directions and cost L3.10s.0d. (L3.50). The Lady's Dispensary which contained twenty medicines, including two pills, with some dispensing equipment and a book of directions cost L5.10s.0d. (L5.50). In all, he listed twenty different cabinets and a sea medicine chest ranging in price from L3.10s.0d. to L32.10s.0d. They included ones suitable for the family, country clergymen, and travellers on the continent and in the tropics. In 1862 Savory and Moore stocked a range of sixty-seven different medicine chests and cases in rosewood, mahogany, walnut, boxwood and leather that were fitted with 'modern appliances and conveniences adapted for the requirements of families, clergymen, officers, owners of yachts, and travellers.' Unfortunately no prices are quoted. I think that we can safely assume that the treatment received at the hands of Evan Jones was likely to be rather rough and ready when compared to the ministrations of a physician, surgeon, clergyman or local 'Lady Bountiful', but, nevertheless, must have been of great value to those who could not afford professional treatment.

The effect of compacted cancellous bone grafting on the healing of subchondral bone defects of the medial femoral condyle in horses.

OBJECTIVE: To compare the quality of second-intention healing and that of compacting sternally harvested cancellous bone into subchondral bone defects of the medial femoral condyle in horses. STUDY DESIGN: A controlled experiment using a surgical technique that minimizes soft tissue trauma, customized for consistency among horses. ANIMALS OR SAMPLE POPULATION: Ten horses, aged 2 to 5 years, free of hindlimb lameness and with radiographically normal stifles. METHODS: After a 12.7-mm-diameter x 19-mm-deep defect was created into randomly selected medial femoral condyles, bone and cartilage healing was evaluated over a 6-month period in control horses (n = 5) and horses receiving a compacted cancellous bone graft (n = 5). Healing was evaluated using lameness assessment, radiographic and microradiographic interpretation, arthroscopic appearance, percent bone fill, proteoglycan content, and histology. RESULTS: Six months after surgery, there was no significant difference between grafted and ungrafted defects with respect to lameness, radiographic score, or percent bone fill. Histologically, grafted defects were characterized by the presence of dead graft and secondary cyst formation in four defects. Ungrafted defects filled with fibrous tissue and no cyst formation were identified. CONCLUSIONS: Grafted defects do not heal better than ungrafted defects, and lameness was not affected by surgical technique. CLINICAL SIGNIFICANCE: Cartilage healing is similar in grafted and ungrafted defects in the equine medial femoral condyle at 6 months, suggesting that surgical debridement alone of cystic structures remains the treatment of choice.

Chemiluminescent detection of amines and amino acids using in situ generated Ru(bpy)(3)(3+) following separation by capillary electrophoresis.

A new sensitive chemiluminescent detection method for capillary electrophoresis is described. Underivatized amines and amino acids were detected following capillary electrophoresis separation by their chemiluminescent reaction with Ru(bpy)(3)(3+) generated in situ at 35 mum carbon fibers. Detection limits for triethylamine and proline were 5 and 3 fmol, respectively at a SNR of three. The noise limiting the detectability of separated analytes was determined to exist at the level of the dark noise limit of the PMT used for these studies and additional noise reduction strategies are expected to improve the quantitative aspects of the method. Theoretical plate numbers for proline were approximately 20 000. End column addition of Ru(bpy)(3)(2+) coupled with in situ generation of Ru(bpy)(3)(3+), has been shown to be compatible with the nanoliter elution volumes characteristic of capillary electrophoresis.