Calcium oxalate accumulation and soil weathering in mats of the hypogeous fungus Hysterangium crassum

Fungal mats of Hysterangium crassum (Tul. and Tul.) Fischer occupied a mean of 9.6% of the upper 10 cm of soil developed under a 40–65 yr old stand of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in Oregon. This hypogeous basidiomycete exudes large amounts of oxalic acid, some of which precipitates with Ca in microscopic crystals of calcium oxalate, resulting in a mean CaC₂O₄ content of 82g m^?2 for the entire soil. Soil oxalate concentration was significantly greater within fungal mats (P < 0.01) and soil pH was significantly lower (P < 0.01) than in soil adjacent to mats. The quantity of Ca present as CaC₂O₄ is 0.5 the amount of exchangeable Ca in the soil and exceeds the mass of Ca lost annually in runoff. Scanning electron micrographs show intense chemical weathering, attributable to oxalate attack, in the immediate vicinity of hyphae. X-ray diffraction patterns of clay indicate bulk weathering is more intense within the fungal mats than in adjacent uncolonized soil.     

EFFECTS OF EXPERIMENTAL NERVE ROOT COMPRESSION ON ARTERIAL BLOOD FLOW VELOCITY IN THE SEVENTH LUMBAR SPINAL GANGLION OF THE DOG: MEASUREMENT USING INTRAOPERATIVE DOPPLER ULTRASONOGRAPHY

Intraoperative Doppler ultrasonography was used to measure the effects of four experimental nerve root compression treatments (central compression, central-plus-lateral compression, lateral compression, and compression release) on arterial blood flow velocities in the seventh lumbar spinal ganglion of three dogs. Graphed blood flow velocity changes (change = treatment value − pretreatment value) were below baseline during the first three compression treatments and above baseline following compression release. Mean blood flow velocity changes for both central-plus-lateral compression and lateral compression differed (p ≤ 0.05) from changes for central compression. Changes for central-plus-lateral compression did not differ (p > 0.05) from changes for lateral compression. Changes among the first three compression treatments differed (p ≤ 0.05) from changes for compression release. No histologic abnormalities were identified in compressed nerve tissues, compared to contralateral controls. These findings indicate that stenosis within the L7-S1 intervertebral foramen may cause ischemia of the L7 spinal ganglion in dogs.     

A rapid high-pressure liquid chromatographic method for the determination of carbaryl residues in wheat grain

Carbaryl residues in wheat grain have been determined in methanol extracts using normal-phase high-pressure liquid chromatography (h. p. l. c.) with ultraviolet detection. A single-injection, clean-up and analysis technique was used to allow more rapid analysis of samples after extraction. A detection limit of 0.1 mg kg^?1 in a 50 g sample of wheat was achieved. Recoveries of 86% at the 1 mg kg^?1 level and 90-99% at the 5 mg kg^?1 level were obtained for fortified grain samples. Methanol was found to be a superior extractant for carbaryl from wheat when compared with hexane, acetone and dichloromethane. Twelve samples containing aged carbaryl residues were analysed by the h. p. l. c. technique and by a colorimetric procedure which allowed statistical analysis of errors. For the h. p. l. c. method (excluding sampling error), a relative standard deviation of 4.4% was obtained.     

Seroprevalence of bovine brucellosis and associated risk factors in Nakasongola district,Uganda

A cross-sectional study was carried out between November 2015 and January 2016 to determine the seroprevalence of Brucella antibodies in cattle raised under communal, fenced farms and tethering systems and the associated factors. Seven hundred twenty-eight bovine sera were collected and tested with rose Bengal test as a screening test and the indirect enzyme-linked immunosorbent assay as a confirmatory test. Animal- and herd-level data were collected and binary logistic regression was used to assess the potential risk factors. True animal- and herd-level prevalence was highest in the fenced farms (4.5% (95%CI, 2.3–6.9) and 19.5% (95%CI, 8.2–32.7) respectively). The risks for natural brucellosis infection were sharing water with wild animals (OR = 0.21, 95%CI, 0.104–0.83), herd size (medium: OR = 0.089, 95%CI 0.017–0.449; large: OR = 0.024, 95%CI 0.003–0.203), fenced farms (OR = 3.7, 95% CI, 1.7–7.9), sex (OR = 0.03, 95%CI, 0.01–0.079), and lactation (OR = 0.013, 95%CI, 0.004–0.049). Changes in rangeland tenure and the shift towards intensive cattle production have influenced brucellosis epidemiology. Future studies should aim at identifying the infecting Brucellae and examining the role of wildlife in brucellosis epidemiology.

     

Pet Ownership,Attitude Toward Pets,and Support for Wildlife Management Strategies

Pet ownership affects engagement with animal-related activities and may be related to support of wildlife management. British participants (N = 220) completed an online survey providing information on pet ownership, attitudes toward pets, and support for wildlife management strategies. Within this sample, pet owners and individuals with positive attitudes toward pets were less supportive of strategies that put human needs before the needs of wildlife, more supportive of strategies attempting to avoid species extinctions, and opposed to strategies requiring compromises of individual species. Pet owners’ affectionate attitudes toward animals and opposition to their exploitation may be important in dictating attitudes toward wildlife. Conservation planners could apply these findings when seeking support for management strategies that constrain freedoms of pets and wildlife. Utilizing the sympathetic attitudes of pet owners toward animals by focusing on welfare and survival benefits for wildlife species may help foster support for management strategies.     

Elimination of false-positive polymerase chain reaction results resulting from hole punch carryover contamination.

The collection of biological material (e.g., blood) directly onto filter paper for subsequent use in laboratory assays such as polymerase chain reaction (PCR), has become a common practice. Dried cells or fluid on the paper can be readily rehydrated and retrieved into a standard volume of an appropriate elution buffer but introduces a dilution factor to the sample. The use of a common cutting instrument for excising a standard-sized piece of paper that contains the material also introduces the potential for transferring biological material from one sample to subsequent samples, causing false-positive results by PCR. In the present study, filter-paper-collected blood that contained beak and feather disease virus was used to determine if viral DNA could be transferred between samples by a hole punch used to excise sequential filter papers. It was determined that false-positive results could be obtained at least 13 times after a positive sample. Subsequently, the efficacy of 4 methods of hole punch disinfection, flaming, VirkonS, bleach, and a bleach-ethanol combination, was assessed. The only effective and practical method to destroy DNA was a method where the hole punch was agitated in commercial bleach, rinsed in water, the water was displaced with 100% ethanol and air-dried. This method was simple, cheap, and relatively rapid, and allowed for the use of a single hole punch for a series of samples, without carryover contamination and consequent false-positive results.     

Landscape structure influences avian malaria ecology in the Western Cape, South Africa

A central theme in landscape ecology is that of understanding the consequences of landscape heterogeneity for ecological processes. The effects of landscape heterogeneity on parasite communities are poorly understood, although it has been shown that anthropogenic impacts may contribute to outbreaks of both parasites and pathogens. We tested for effects of landcover type, composition, configuration, and urbanisation on avian diversity and avian malaria prevalence in 26 communities of wetland-associated passerines in the Western Cape of South Africa. We predicted that avian malaria prevalence would be influenced by the pattern of farmland and urban areas in the surrounding landscapes and the sizes of the wetlands in which birds were sampled. We quantified landscape pattern using a six-class simplification of the National Landcover data set at 35 × 35 m resolution and five extents of between 1 and 20 km from each wetland. The bird community was sampled using point counts and we collected blood samples from birds at each site. We screened these for malaria using PCR and molecular techniques. Passerine species richness and infection prevalence varied significantly between different landcover types. Host richness and parasite prevalence were highest in viticultural and cropping sites respectively and lowest in urban sites. Wetlands located in indigenous vegetation had intermediate numbers of bird species and intermediate parasite prevalence. Landscape composition and habitat type surrounding wetlands emerged as useful correlates of infection prevalence. Anthropogenic landscape modification appears to have both direct and indirect effects on avian communities and their associated parasite assemblages, with attendant consequences for avian health.     

Population management: potential impacts of advances in genomics

Even with advanced gene technologies continued population improvement remains a key foundation for future genetic gain in forest trees. Currently, this is served by maintaining genetic diversity while capturing genetic improvement, often through structuring populations into a genetic hierarchy, setting population sizes, and managing pedigrees and inbreeding. In the future, information from genomic technologies will complement classical approaches, such as common-garden field experiments, for characterizing the genetic base and measuring and monitoring genetic diversity. This will entail directly measuring DNA sequence diversity of both selectively neutral markers and functional genes. Calibrating neutral marker diversity against functional diversity will become easier with functional genomics. For maintaining pedigree and managing inbreeding, genomic information can be used to relax some traditional tenets of population management. With future knowledge of functional polymorphisms, the better understanding of the nature and origins of genetic variation should enhance management of populations to both conserve genetic diversity and exploit it by more efficient selection. Where fungal diseases threaten biotic crises, very large populations may be needed, the requisite sizes often being very uncertain. Gene discovery holds enormous promise, but depends heavily on comparative genomics, capitalizing on genomic information from Arabidopsis, Populus and Eucalyptus, and the increasing numbers of accessible ESTs. Much greater insights into non-codon mutational processes and rates should also guide population management. A key challenge, however, will be to utilize information and apply tools cost-effectively. Also, very detailed genomic information, exemplified by the poplar-genome sequencing, may allow earlier adaptation of technology and development of new information in angiosperms than in gymnosperms.