Surgical treatment of a mammary gland comedocarcinoma in an Arabian mare: Post-operative management,and histopathological and immunohistochemical features

A lactating 20-year-old, brown, Arabian mare, weighing about 300 kg, presented for bleeding from one teat and severe swelling of the entire mammary gland. The mare had untreated mastitis 10 months before. Consequently, a gangrenous teat developed after chronic bloody and purulent discharges. The teat was removed surgically by the field veterinarian. At that time, the mammary gland increased in size. Bloody and purulent discharges restarted 10 days previously. Under general anaesthesia, the entire mammary gland was removed. Comedocarcinoma was diagnosed by histopathological assessment. Immunohistochemical staining was performed for pan-cytokeratin and vimentin. Microscopic examination of immunohistochemical stained slides revealed expression of pan-cytokeratin. In conclusion, this report describes clinical, macroscopic, histopathological and immunohistochemical characteristics of comedocarcinoma that did not metastasise to regional lymph nodes. Reports in the field of equine oncology contribute to improved general knowledge in equine medicine, contributing to better diagnosis and treatment.     

Isolating the effect of soil properties on agricultural soil greenhouse gas emissions under controlled conditions

Agricultural soils are important sources of greenhouse gases (GHGs). Soil properties and environmental factors have complex interactions which influence the dynamics of these GHG fluxes. Four arable and five grassland soils which represent the range of soil textures and climatic conditions of the main agricultural areas in the UK were incubated at two different moisture contents (50 or 80% water holding capacity) and with or without inorganic fertiliser application (70 kg N ha⁻¹ ammonium nitrate) over 22 days. Emissions of N₂O, CO₂ and CH₄ were measured twice per week by headspace gas sampling, and cumulative fluxes were calculated. Multiple regression modelling was carried out to determine which factors (soil mineral N, organic carbon and total nitrogen contents, C:N ratios, clay contents and pH) that best explained the variation in GHG fluxes. Clay, mineral N and soil C contents were found to be the most important explanatory variables controlling GHG fluxes in this study. However, none of the measured variables explained a significant amount of variation in CO₂ fluxes from the arable soils. The results were generally consistent with previously published work. However, N₂O emissions from the two Scottish soils were substantially more sensitive to inorganic N fertiliser application at 80% water holding capacity than the other soils, with the N₂O emissions being up to 107 times higher than the other studied soils.     

Genetic diversity and aggressiveness of Calonectria pteridis in Eucalyptus spp.

Calonectria leaf blight, caused by Calonectria pteridis, is currently one of the main foliar diseases in eucalypt plantations in Brazil. In warm and high rainfall regions, the disease can be a limiting factor for eucalypt production when planting susceptible genotypes. The most effective method for controlling this disease in the field is the use of resistant genotypes, which requires knowledge of the genetic variability and aggressiveness of the pathogen population for effective deployment of plant resistance. This work evaluated the genetic diversity and aggressiveness of C. pteridis populations obtained from infected eucalypt plants in Monte Dourado (Pará state) and Imperatriz (Maranhão state), Brazil. To study the genetic diversity, 16 ISSR primers were tested, five of which amplified polymorphic, reproducible and informative bands. Thirty-one closely related genotypes were identified from 84 isolates studied, indicating that the population has a low genetic diversity. The aggressiveness of seven isolates, selected according to geographic origin and their clustering in the ISSR-based dendogram, was determined by inoculation of a hybrid Eucalyptus grandis × E. urophylla clone under controlled conditions. Disease severity was assessed by both measuring the percentage of plant defoliation and assigning a score according to a diagrammatic scale of symptoms. A high correlation between the two evaluation methods was observed, which revealed significant differences in aggressiveness among the isolates. The diagrammatic scale is recommended for disease evaluation because results are obtained much faster, before the occurrence of severe defoliation. No correlation between clustering in the ISSR-based phylogenetic analysis and aggressiveness was observed.     

Beaver dams,streamflow complexity,and the distribution of a rare minnow,Lepidomeda copei

Freshwater fishes are threatened globally, and often too little is known about threatened species to effectively guide their conservation. Habitat complexity is linked to fish species diversity and persistence, and degraded streams often lack habitat complexity. Beaver Castor spp., in turn, have been used to restore streams and increase habitat complexity. The northern leatherside chub Lepidomeda copei is a rare, small‐bodied, drift‐feeding minnow that has anecdotally been observed to use complex habitats associated with beaver dams in the western United States. To investigate this anecdote, we conducted fish and habitat surveys, the latter focusing on quantifying habitat complexity, in a sub‐basin of the Upper Snake River Basin in the USA. Complementary generalised linear model and path analyses revealed that northern leatherside chub occurred more often at sites with complex streamflows, and streamflows were more complex when beaver dams were present and pools were deeper. Northern leatherside chubs were also more likely to occur when temperatures were warmer, aquatic macrophytes were abundant and stream channels were narrow and deep. The linkage between chubs, complex streamflows and beaver dams needs to be evaluated more broadly to completely understand its role in the rangewide status of the species. However, it does suggests that increased use of beaver reintroductions and dam analogues for stream restoration could be a boon for the northern leatherside chub, but such efforts should be monitored to determine their effectiveness to help adapt beaver‐based restoration approaches to best benefit the species.     

Rhynchosporium leaf scald disease incidence: seed source and spatial pattern

A programme of field trials for the study of the winter barley–Rhynchosporium commune pathosystem is reported. The associated seedborne disease rhynchosporium leaf scald is regarded as having an important impact on barley yields. The analysis in this study relates to the impact of the seed source (commercial or farm-saved seed) on disease incidence and to the spatial pattern of rhynchosporium leaf scald disease incidence. Disease incidence data were calculated from field data recorded as disease severity. Mean disease incidence was higher in the crops grown from farm-saved seed than in those grown from commercial seed, although great agronomic significance cannot be attached to this result. The spatial pattern of rhynchosporium leaf scald disease incidence was characterized in terms of the binary power law (BPL) and was indicative of an aggregated pattern. Programme-wide BPL results were described using a novel phytopathological application of a random coefficients model. These results have application in field sampling for rhynchosporium leaf scald disease.     

Selection,optimization and characterization of molecular tests for the detection of Tobacco ringspot virus (TRSV)

The aim of the study was to select, optimize and characterize RT‐PCR tests for the detection of Tobacco ringspot virus (TRSV) in post‐entry quarantine. Among five different tests, the Poojari et al. (Journal of Virological Methods 235, 112–118) and Jossey & Babadoost (Plant Disease 90, 1361) conventionnal RT‐PCR tests were chosen and optimized for this purpose. Ten TRSV isolates, 17 healthy plants from the genera Vitis, Prunus and Malus, four other Nepoviruses or Secoviridae isolates and serial dilutions of three TRSV isolates were used for the complete characterization of the optimized tests. In the tested conditions, the Poojari and Jossey & Babadoost tests respectively showed 100% and 95% inclusivity, 100% and 100% exclusivity, 100% and 96.4% analytical specificity, 100% and 100% diagnostic specificity, [10^?7; 10^?1] and [10^?8; 10^?2] limit of detection dilution factors (analytical sensitivity), 91.1% and 90.0% repeatability, 90.3% and 91.1% reproducibility and 100% and 100% selectivity. Due to its higher inclusivity, the optimized Poojari test is recommended for the detection of TRSV isolates for post‐entry quarantine purposes, but can also be used for global surveys. The optimized Jossey & Babadoost test showed the best analytical sensitivity, suggesting that combining both tests can further enhance detection.     

Multilocus sequence typing analysis of Italian Xanthomonas campestris pv. campestris strains suggests the evolution of local endemic populations of the pathogen and does not correlate with race distribution

Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot in Brassicaceae. It is widespread in Italy and severe outbreaks occur under conditions that favour disease development. In this study a multilocus sequence typing approach (MLST) based on the partial sequence of seven loci was applied to a selection of strains representative of the main areas of cultivation and hosts. The aim was to investigate whether the long tradition of brassica crops in Italy has influenced the evolution of different Xcc populations. All loci were polymorphic; 14 allelic profiles were identified of which 13 were unique to Italian strains. Based on the seven loci, the most common genotype within the Italian Xcc strains (AP1) was also the most representative genotype found in worldwide Xcc strains. This genotype was included in a new clonal complex in addition to three other clonal complexes already identified in Xcc populations. The phylogenetic reconstruction using a concatenated dataset of four conserved protein-coding genes, dnaK, fuyA, gyrB and rpoD, showed that the Italian strains belonged to two genetic groups. Physiological races were also investigated for the first time in Italy. The race structure of Xcc was determined by inoculating eight differential Brassica lines belonging to five species and showed that, in Italy, race 4 is the most widespread, followed by races 1 and 6. No correlation was found between allelic profiles, host of isolation, geographical origin and races, although a prevalent race was identified within the same clonal complex.     

Growth pattern of Juncus effusus and Juncus conglomeratus in response to cutting frequency

Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost‐effective means to control rushes. In a field experiment in western Norway, we investigated development of above‐ and below‐ground fractions of rush from seedlings to three‐year‐old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above‐ground:below‐ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below‐ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.     

Patterns of fish movement at a desert river confluence

Quantifying fish movements in river networks helps identify critical habitat needs and how they change with environmental conditions. Some of the challenges in tracking fish movements can be overcome with the use of passive integrated transponder (PIT) tagging and antennas. We used PIT technology to test predictions of movement behaviour for four fish species at a mainstem–tributary confluence zone in an arid‐land river system. Specifically, we focused on the McElmo Creek tributary confluence with the San Juan River in south‐western Utah, USA. We quantified variation in species occurrences at this confluence zone from May 2012 to December 2015 relative to temporal and environmental conditions. We considered occurrences among species relative to tagging origins (tributary versus mainstem), season and time of day. Generally, fishes tagged in the focal tributary were more likely to be detected compared to fish tagged in the mainstem river or other tributaries. Additionally, adults were most likely to be detected across multiple years compared to subadults. Based on a Random Forests model, the best performing environmental variables for predicting seasonal detections included mainstem discharge during run‐off season (razorback sucker Xyrauchen texanus), tributary discharge during monsoon season (Colorado pikeminnow Ptychocheilus lucius) and mainstem water temperature (flannelmouth sucker Catostomus latipinnis and channel catfish Ictalurus punctatus). The variable responses by endemic and introduced fishes indicate tributary habitats provide several key functions within a fish community including spawning, rearing, foraging and refuge.     

Animal movement varies with resource availability,landscape configuration and body size: a conceptual model and empirical example

Landscape Ecology - Animals must move to find food, shelter and mates, and escape predation and competition. Changes in landscape configuration and resource availability can disrupt natural...