Uterine Infection Influences Size and Follicular Fluid Composition of the Largest Follicle in Buffalo (Bubalus bubalis)

The effect of uterine infection on size and follicular fluid composition of the largest follicle was studied in buffalo. Reproductive tracts were collected from 102 graded Murrah buffaloes at an abattoir. Uterine infection was diagnosed by physical examination of uterine mucus, white side test and uterine cytology. Samples with pus‐containing mucus, positive reaction on white side test and/or >5% neutrophils were considered to be positive for uterine infection. Diameter of the largest follicle was measured, and follicular fluid was aspirated and assayed for nitric oxide (NO), ascorbic acid (AA), cholesterol, oestradiol (E₂) and progesterone (P₄). Infected buffaloes had smaller‐sized (p < 0.0001) largest follicles than non‐infected buffaloes. Follicular fluid collected from the largest follicle in infected buffaloes had greater (p < 0.0001) NO and P₄ concentrations coincident with lesser AA (p < 0.001), cholesterol (p < 0.0001) and E₂ (p < 0.0001) concentrations. Results indicated that uterine infection has an inhibitory effect on growth of the largest follicle in buffalo. The changes in follicular fluid composition in infected buffaloes suggest that the direct effect of uterine infection on ovarian function may be mediated through an alteration in the follicular microenvironment. Greater NO and lesser AA concentrations in the follicular fluid of infected animals are novel findings.     

Attitudes of dog owners to neutering pets: demographic data and effects of owner attitudes

SUMMARY A survey of the attitudes of dog owners to desexing male and female dogs was conducted in the Brisbane area. Over 15800 replies (35% response) were returned for analyses and included both demographic and attitude data. The most common reasons given by owners for not having the dog desexed were that it was unnecessary or they wanted to breed from it or could not afford it or did not agree with it or that the dog was too old or it might get fat. Nearly twice as many male owners agreed that desexing male dogs removed maleness and also more males agreed with the question “Do you equate dog sexuality with human sexuality?” Female owners were more aware than males that their female dogs did not need to have a season (oestrus) or a litter before being desexed. More male owners thought that desexing changed a male or female dog's personality. A disturbing fact was that 61.1% of male owners and 47.3% of female owners would now not have their dog desexed if it had not already been done. More male than female dog owners were ignorant about whether desexing changed personality, made dogs frustrated, or if female dogs should have a season or a litter before desexing. The study showed a gender bias in owner attitudes to all the attitude questions.     

Evidence that nematodes may vector the soft rot‐causing enterobacterial phytopathogens

Bacterial soft rot is a globally significant plant disease that causes major losses in the production of many popular crops, such as potato. Little is known about the dispersal and ecology of soft‐rot enterobacteria, and few animals have been identified as vectors for these pathogens. This study investigates whether soil‐living and bacterial‐feeding nematodes could act as vectors for the dispersal of soft‐rot enterobacteria to plants. Soft‐rot enterobacteria associated with nematodes were quantified and visualized through bacterial enumeration, GFP‐tagging, and confocal and electron scanning microscopy. Soft‐rot enterobacteria were able to withstand nematode grazing, colonize the gut of Caenorhabditis elegans and subsequently disperse to plant material while remaining virulent. Two nematode species were also isolated from a rotten potato sample obtained from a potato storage facility in Finland. Furthermore, one of these isolates (Pristionchus sp. FIN‐1) was shown to be able to disperse soft‐rot enterobacteria to plant material. The interaction of nematodes and soft‐rot enterobacteria seems to be more mutualistic rather than pathogenic, but more research is needed to explain how soft‐rot enterobacteria remain viable inside nematodes.     

Forest stand age classification using time series of photogrammetrically derived digital surface models

In this research, we developed and tested a remote sensing-based approach for stand age estimation. The approach is based on changes in the forest canopy height measured from a time series of photo-based digital surface models that were normalized to canopy height models using an airborne laser scanning derived digital terrain model (DTM). Representing the Karelian countryside, Finland, CHMs from 1944, 1959, 1965, 1977, 1983, 1991, 2003, and 2012 were generated and allow for characterization of forest structure over a 68-year period. To validate our method, we measured stand age from 90 plots (1256?m²) in 2014, whereby producer's accuracy ranged from 25.0% to 100.0% and user's accuracy from 16.7% to 100.0%. The wide range of accuracy found is largely attributable to the quality and characteristics of archival images and intrastand variation in stand age. The lowest classification accuracies were obtained for the images representing the earliest dates. For forest managers and agencies that have access to long-term photo archives and a detailed DTM, the estimation of stand age can be performed, improving the quality and completeness of forest inventory databases.     

Invasions of non-native earthworms related to population declines of ground-nesting songbirds across a regional extent in northern hardwood forests of North America

Non-native invasive earthworms (Lumbricus spp.) substantially change previously earthworm-free hardwood forests of North America by consuming the leaf litter layer, reducing cover and richness of herbaceous plants, and increasing dominance of sedges and grasses. These changes have been associated with reduced density of Ovenbirds (Seiurus aurocapilla) and Hermit Thrushes (Catharus guttatus) in 10–20 ha forest stands, and with reduced Ovenbird nesting success. Whether earthworms reduce songbird populations across a regional extent is unclear. We investigated relationships among Lumbricus, vegetation structure, landscape patterns of forest cover, and density of four ground-nesting songbird species at points scattered across the Chequamegon-Nicolet (Wisconsin) and Chippewa (Minnesota) National Forests, USA. In both national forests, Ovenbird density was significantly lower at invaded points than Lumbricus-free points, but only in sugar maple (Acer saccharum) and sugar maple/basswood (Tilia americana) (hereafter, maple-basswood) woodlands. Density of the Hermit Thrush, Black-and-white Warbler (Mniotilta varia), and Veery (Catharus fuscescens) did not differ in relation to Lumbricus. In maple-basswood forests, Lumbricus biomass was the best predictor of Ovenbird density, with greater biomass associated with reduced density. Vegetation structure and landscape pattern variables received weak support as density predictors. Across all forest types, Ovenbird density was most strongly related to forest cover within 500 and 1,000 m radii. Our results suggest that earthworm invasions may pose a regional threat to Ovenbirds within maple-basswood forests of the U.S. northern Midwest.