Environmental fate of mineral,vegetable and transesterified vegetable oils

Vegetable oils, synthetic esters (including transesterified oils) and mineral oils are the main classes of oil used in pesticide formulations. Biodegradation is a major route for the removal of oils from soil systems. Most of the oils used in pesticide formulations are degraded substantially in the laboratory tests that are used to assess aquatic biodegradability. The susceptibility of different oils to biodegradation can be explained in terms of the metabolic capacity of common microorganisms. Fewer soil biodegradability tests have been carried out with oils, but the available data suggest that the mode of degradation is not very different from that in aquatic systems. Supplements of inorganic nutrients (in particular nitrogen) are needed to stimulate microbial activity in soils containing the high concentrations of oil that can be encountered in the event of a spill. However, oils are applied at such low rates in pesticide form illations (maximum of 5g oil m^? soil) that nutrient availability is unlikely to affect the rate of biodegradation in the field.     

Isolates of Verticillium dahliae Pathogenic to Crucifers Are of at Least Three Distinct Molecular Types

ABSTRACT Diverse isolates of the soilborne wilt fungi Verticillium dahliae and V. albo-atrum were studied to understand the nature and origins of those infecting cruciferous hosts. All isolates from cruciferous crops produced microsclerotia, and the majority produced long conidia with a high nuclear DNA content; these isolates were divided into two groups by amplified fragment length polymorphism (AFLP) analysis. One group could be subdivided by other criteria such as rRNA sequences and mitochondrial DNA restriction fragment length polymorphism (RFLP) analysis. Two crucifer isolates were short spored and had a low nuclear DNA content. The results are consistent with the crucifer isolates being interspecific hybrids. The long-spored isolates are best regarded as amphihaploids (or allodiploids) with the AFLP groups probably each representing separate interspecific hybridization events. The short-spored crucifer isolates appear to be derived from interspecific hybrids and are here called 'secondary haploids'. Molecular evidence suggests that one parent in the crosses was similar to V. dahliae. The other parent of the amphihaploids seems to have been more similar to V. albo-atrum than to V. dahliae, but was distinct from all isolates of either species so far studied. The implications for the taxonomy of crucifer isolates are discussed and the use of the name V. longisporum, proposed elsewhere for just some of these isolates, is discouraged.     

The longevity of immunoglobulin preservation in canine skin utilizing Michel's fixative

Skin biopsy specimens from 7 dogs with immune-mediated skin diseases diagnosed by routine histology and 5 dogs with other skin diseases were placed in Michel's transport medium for 4 to 9 years. Direct immunofluorescence yielded positive results in tissue samples from 3 dogs with pemphigus foliaceus and 2 dogs with discoid lupus erythematosus. Direct immunofluorescence was not seen in tissue samples from 1 dog with pemphigus foliaceus and 5 dogs with non immune-mediated skin diseases. Direct immunofluorescence was seen in skin biopsy specimens maintained in Michel's medium for 4 to 8 years.     

Density and Organic Matter Influence on Egg‐laying and Hatching of Branchiura sowerbyi (Oligochaeta)

This study aimed to assess the combined effects of density of adults of Branchiura sowerbyi and the source of organic matter on the production of eggs and young species. The experimental units used were 250‐mL beakers with 100 mL of fine sand (0.074–0.210 mm) and 150 mL of chlorine‐free water with constant aeration at the temperature 25 C. The experiment was conducted based on a two‐factor model with six treatments and three repetitions, applied in a completely random design. The densities 5 individuals/38.5cm² (D5; 1298/m²) and 8 individuals/38.5cm² (D8; 2078/m²) were assessed with commercial fish feed (FF), commercial poultry feed (PF), and turkey manure (TM) as sources of organic matter. A total of 1223 cocoons and 2138 eggs were produced, with average hatching of 40.0 ± 15.1%. The highest number of cocoons and eggs was found with the use of PF, D8 having produced the highest number of cocoons and eggs. The hatching rate was not influenced by the source of organic matter or density and no influence was registered from the density of adults on the survival. The PF provided the highest growth of adults, and generally the use of TM provided the worst performance.     

Light-energy processing and freezing-tolerance traits in red spruce and black spruce: species and seed-source variation

Red spruce (Picea rubens Sarg.) and black spruce (Picea mariana (Mill.) B.S.P.) are genetically and morphologically similar but ecologically distinct species. We determined intraspecific seed-source and interspecific variation of red spruce and black spruce, from across the near-northern margins of their ranges, for several light-energy processing and freezing-tolerance adaptive traits. Before exposure to low temperature, red spruce had variable fluorescence (Fv) similar to black spruce, but higher photochemical efficiency (Fv/Fm), lower quantum yield, lower chlorophyll fluorescence (%), and higher thermal dissipation efficiency (qN), although the seed-source effect and the seed-source x species interaction were significant only for Fv/Fm. After low-temperature exposure (-40 degrees C), red spruce had significantly lower Fv/Fm, quantum yield and qN than black spruce, but higher chlorophyll fluorescence and relative fluorescence. Species, seed-source effect, and seed-source x species interaction were consistent with predictions based on genetic (e.g., geographic) origins. Multi-temperature exposures (5, -20 and -40 degrees C) often produced significant species and temperature effects, and species x temperature interactions as a result of species-specific responses to temperature exposures. The inherent physiological species-specific adaptations of red spruce and black spruce were largely consistent with a shade-tolerant, late-successional species and an early successional species, respectively. Species differences in physiological adaptations conform to a biological trade-off, probably as a result of natural selection pressure in response to light availability and prevailing temperature gradients.     

Soil carbon distribution and quality in a montane rangeland-forest mosaic in northern Utah

Relatively little is known about soil organic carbon (SOC) dynamics in montane ecosystems of the semi-arid western U.S. or the stability of current SOC pools under future climate change scenarios. We measured the distribution and quality of SOC in a mosaic of rangeland-forest vegetation types that occurs under similar climatic conditions on non-calcareous soils at Utah State University's T.W. Daniel Experimental Forest in northern Utah: the forest types were aspen [Populus tremuloides] and conifer (mixture of fir [Abies lasiocarpa] and spruce [Picea engelmannii]); the rangeland types were sagebrush steppe [Artemisia tridentata], grass-forb meadow, and a meadow-conifer ecotone. Total SOC was calculated from OC concentrations, estimates of bulk density by texture and rock-free soil volume in five pedons. The SOC quality was expressed in terms of leaching potential and decomposability. Amount and aromaticity of water-soluble organic carbon (DOC) was determined by water extraction and specific ultra violet absorbance at 254 nm (SUVA) of leached DOC. Decomposability of SOC and DOC was derived from laboratory incubation of soil samples and water extracts, respectively.

Although there was little difference in total SOC between soils sampled under different vegetation types, vertical distribution, and quality of SOC appeared to be influenced by vegetation. Forest soils had a distinct O horizon and higher SOC concentration in near-surface mineral horizons that declined sharply with depth. Rangeland soils lacked O horizons and SOC concentration declined more gradually. Quality of SOC under rangelands was more uniform with depth and SOC was less soluble and less decomposable (i.e., more stable) than under forests. However, DOC in grass-forb meadow soils was less aromatic and more bioavailable, likely promoting C retention through cycling. The SOC in forest soils was notably more leachable and decomposable, especially near the soil surface, with stability increasing with soil depth. Across the entire dataset, there was a weak inverse relationship between the decomposability and the aromaticity of DOC. Our data indicate that despite similar SOC pools, vegetation type may affect SOC retention capacity under future climate projections by influencing potential SOC losses via leaching and decomposition.     

Consumer willingness to pay price premiums for environmentally certified wood products in the U.S.

Since its inception nearly 15 years ago, environmental certification has become an important issue in the wood products industry. One research question that has been examined is the potential willingness for supply chain participants to pay a premium for certified products or raw materials to offset certification costs. This study examines stated willingness to pay for four wood products from the perspective of U.S. consumers. Data was collected in 1995 and 2005 from the population of U.S. residential consumers to detect changes in willingness to pay for certified wood products along time and increase the statistical strength of the model. Results of an ordered probit model suggest that higher probabilities of paying a premium are associated to consumers who seek out certified products and who believe certification can lessen environmental impacts such as tropical deforestation. There is also a strong relationship between respondent income and willingness-to-pay. Despite the current industry structure in the U.S. that has adopted a mass-certification strategy that does not place price premiums on certified products, results suggest that such premiums may exist for imported certified tropical wood products. Analysis of marginal effects suggests consumers' willingness to pay a 10% premium for three of the four certified items studied. Niche markets may potentially be exploited in the U.S. and price premiums captured by wood products manufacturers in tropical regions and/or American importers.     

Use of genomic recursions and algorithm for proven and young animals for single‐step genomic BLUP analyses – a simulation study

The purpose of this study was to examine accuracy of genomic selection via single‐step genomic BLUP (ssGBLUP) when the direct inverse of the genomic relationship matrix ( G ) is replaced by an approximation of G ^?1 based on recursions for young genotyped animals conditioned on a subset of proven animals, termed algorithm for proven and young animals (APY). With the efficient implementation, this algorithm has a cubic cost with proven animals and linear with young animals. Ten duplicate data sets mimicking a dairy cattle population were simulated. In a first scenario, genomic information for 20k genotyped bulls, divided in 7k proven and 13k young bulls, was generated for each replicate. In a second scenario, 5k genotyped cows with phenotypes were included in the analysis as young animals. Accuracies (average for the 10 replicates) in regular EBV were 0.72 and 0.34 for proven and young animals, respectively. When genomic information was included, they increased to 0.75 and 0.50. No differences between genomic EBV (GEBV) obtained with the regular G ^?1 and the approximated G ^?1 via the recursive method were observed. In the second scenario, accuracies in GEBV (0.76, 0.51 and 0.59 for proven bulls, young males and young females, respectively) were also higher than those in EBV (0.72, 0.35 and 0.49). Again, no differences between GEBV with regular G ^?1 and with recursions were observed. With the recursive algorithm, the number of iterations to achieve convergence was reduced from 227 to 206 in the first scenario and from 232 to 209 in the second scenario. Cows can be treated as young animals in APY without reducing the accuracy. The proposed algorithm can be implemented to reduce computing costs and to overcome current limitations on the number of genotyped animals in the ssGBLUP method.     

Global parasite and Rattus rodent invasions: The consequences for rodent‐borne diseases

We summarize the current knowledge on parasitism‐related invasion processes of the globally invasive Rattus lineages, originating from Asia, and how these invasions have impacted the local epidemiology of rodent‐borne diseases. Parasites play an important role in the invasion processes and successes of their hosts through multiple biological mechanisms such as “parasite release,” “immunocompetence advantage,” “biotic resistance” and “novel weapon.” Parasites may also greatly increase the impact of invasions by spillover of parasites and other pathogens, introduced with invasive hosts, into new hosts, potentially leading to novel emerging diseases. Another potential impact is the ability of the invader to amplify local parasites by spillback. In both cases, local fauna and humans may be exposed to new health risks, which may decrease biodiversity and potentially cause increases in human morbidity and mortality. Here we review the current knowledge on these processes and propose some research priorities.