Cells infected with Jaagsiekte sheep retrovirus are detected in the bone marrow of asymptomatic sheep

Ovine pulmonary adenocarcinoma (OPA) is a transmissible lung cancer caused by Jaggsiekte sheep retrovirus (JSRV). It is difficult to identify animals infected with JSRV but are clinically healthy. The virus does not induce a specific antibody response and, although proviral DNA sequences of JSRV can be found in mononuclear blood cells, the detection is inconsistent. The aim of this study was to investigate the presence of JSRV in the bone marrow of infected sheep and develop a more consistent screening method. Immunohistochemical examination of bone marrow samples from 8 asymptomatic JSRV-infected sheep revealed the presence of positively labelled cells. However, JSRV could not be detected by a highly sensitive polymerase chain reaction (PCR) in bone marrow aspirates periodically collected from these animals. Results suggest that JSRV-infected cells may be present in the bone marrow of symptomless animals, but the number is below the detectable level for PCR. Therefore, this technique does not seem to be helpful for preclinical diagnosis of OPA.     

Biochemical and molecular differences in diploid and triploid ocean-type chinook salmon (<Emphasis Type="Italic">Oncorhynchus tshawytscha</Emphasis>) smolts

There is increasing evidence for complex dosage effects on gene expression, enzyme activity and phenotype resulting from induced ploidy change. In this study, ocean-type chinook salmon were bred using a 2 × 2 factorial mating design to create four families and test whether triploidization resulted in changes in growth performance and smolting. Eggs were pressure shocked after fertilization to create triploid fish from a subset of each family. In June, fish were sampled for size, plasma insulin-like growth factor 1 (IGF-1), gill Na⁺–K⁺-ATPase activity, and expression of two Na⁺–K⁺-ATPase α subunits in the gill. Diploids were significantly heavier than triploids, and there were significant differences due to family. Despite a significant positive correlation between plasma IGF-1 and fish size, plasma IGF-1 did not differ between diploid and triploid smolts. Diploids also had significantly greater gill Na⁺–K⁺-ATPase enzyme activities than triploids and there was a strong family effect. Gill Na⁺–K⁺-ATPase α1b isoform expression differed significantly by family, but not ploidy, and generally families with lower Na⁺–K⁺-ATPase enzyme activity had higher α1b isoform gene expression. Na⁺–K⁺-ATPase α1a isoform expression did not differ among any of the groups. Although diploids were larger and had higher specific activities of Na⁺–K⁺-ATPase in the gills, there was no difference in gene expression or circulating hormone levels. The strong family effect, however, suggests that strain selection may be useful in improving performance of triploids for aquaculture.     

Nanopore sequencing for the detection and identification of Xylella fastidiosa subspecies and sequence types from naturally infected plant material

Xylella fastidiosa (Xf) is a gram-negative bacterial plant pathogen that can infect over 500 plant species. While it is endemic in America, X. fastidiosa subsp. pauca was reported for the first time in Europe in 2013 on olive trees in southern Italy. The availability of fast, sensitive, and reliable diagnostic tools is indispensable for managing current and future outbreaks of Xf. In this paper, we use the OXford Nanopore Technologies (ONT) MinION platform for detecting and identifying Xf at species, subspecies, and sequence type (ST) level. Two workflows were developed: the first one provided a “shotgun” strategy, that is, exploring the possibility of detecting Xf within DNA extracted from plant samples. This allowed detection of Xf by direct DNA sequencing and identifying the subspecies only in samples with high bacterial levels. Nanopore amplicon sequencing was pursued as a second workflow. This consists of PCR amplification of a set of seven multilocus sequence typing (MLST) fragments, officially adopted for identifying Xf at type strain level, followed by Nanopore-sequencing of the amplicons and an ad hoc pipeline to generate MLST consensus calls. This combined approach, which takes only a few hours, allowed the detection and identification of Xf at ST level in plant material with low bacterial infection.     

Outcome of tactile conditioning of neonates, or "imprint training" on selected handling measures in foals

Behavioural reactions to selected handling procedures were compared between conditioned, or imprint-trained, and untrained foals raised on the same farm. Nineteen randomly chosen healthy foals were imprint trained at birth and 24 h later (Group A). Twenty-one similar foals that were not imprint-trained served as age-matched controls (Group B). Training began within 10 min of birth and consisted of touch desensitization by gentle rubbing. Each tactile stimulus was repeated 30-50 times over 45-60 min, until the foal no longer resisted the procedure and appeared relaxed. The procedure was then repeated at 24 h of age. At that time a physical examination and blood analysis were performed to assess the foals' health status. Group B animals were not handled except for a brief physical examination and blood analysis at 24 h of age. Thereafter all foals were kept on pastures with their dams with no further handling until they were three months of age. Any foals handled for other reasons before that time were excluded from the study. At three months, each of the 28 foals that completed the study experienced the following handling procedures: acceptance of restraint, haltering, complete physical examination, acceptance of a plastic rebreathing bag, touching the whole body, intramuscular vaccination in the neck, intranasal vaccination, and deworming with oral paste. Response to each procedure was scored (1=not resistant, 2=low resistance, 3=strong resistance, 4=not possible without major physical restraint). Conditioned foals (Group A) were significantly less resistant to touching the front and hind legs and picking up the hind feet (P < 0.05). The administration of vaccines and paste dewormer and the collection of blood were tolerated by the majority of the foals of both groups with no or low resistance. It appeared that neonatal imprint training resulted in a learned behaviour that resulted in decreased self-defence responses towards handling the limbs at three months of age.     

Multi-scale mismatches between urban sprawl and landscape fragmentation create windows of opportunity for conservation development

Context

Urban sprawl and the expanding transportation infrastructure drive land consumption and landscape fragmentation, causing environmental deterioration and loss of species. Current understanding of how these drivers interact to shape landscape fragmentation is still poor. However, a strong correlation between urban sprawl and landscape fragmentation patterns is commonly assumed.

Objectives

Our main objective was to test the strength, non-stationarity, and scale-dependency of the relationship between urban sprawl and landscape fragmentation patterns (‘sprawl-fragmentation relationship’). Subsequently, we propose an extended framework for the links between urban sprawl, expansion of transport infrastructure, and landscape fragmentation.

Methods

We quantified spatial patterns of urban sprawl and landscape fragmentation for mainland Spain at multiple scales. We then fitted global regression models and geographically weighted regression models with metrics of landscape fragmentation and urban sprawl.

Results

Most variation in landscape fragmentation values (almost 80 % on average) is not explained by urban sprawl metrics through global modeling. Local models show substantial improvements in model performance, with an average of 37 % of the variance remaining unexplained. The contribution of urban sprawl to landscape fragmentation patterns varies locally and depends on scale, with higher contributions at coarser scales and at higher organizational levels.

Conclusions

Our investigation revealed three critical characteristics of the sprawl-fragmentation relationship: it does not prevail, is non-stationary, and scale-dependent. We propose four mechanisms that may have resulted in this mismatch: scale, time-lagged development, spatial arrangement of development, and other external variables including teleconnections. These spatial mismatches provide windows of opportunity for conservation through better development strategies.

     

Frequency of appropriate and inappropriate presentation and analysis methods of ordered categorical data in the veterinary dermatology literature from January 2003 to June 2006

Clinical outcomes that are difficult to measure directly are often graded with ordinal scales in the veterinary dermatology literature to approximate objective evaluation. Ordered categorical scales require statistical presentation and analysis methods consistent with the structure of the data. The objective of this study was to determine the frequency of inappropriate presentation and analysis methods of ordered categorical data in the recent veterinary dermatology literature. A total of 62 articles published between 1 January 2003 and 30 June 2006 in 16 journals reported categorical scales and were included in the study. The presentation and analysis methods of ordered categorical data were classified as appropriate or inappropriate based on published recommendations. Forty articles (64.5%) utilized a median of four ordinal scales (range 1-13). Inappropriate presentation methods of ordered categorical data were identified in 23 of 40 articles (57.5%). These included reporting inappropriate summary statistics (n = 17) and summation of ad hoc numerical rating scales (n = 15). Inappropriate analytical methods were used in nine of 40 articles (22.5%). These included inappropriate use of t-tests (n = 3) and analysis of variance (anova, n = 6). The frequency of inappropriate presentation and analysis methods of ordered categorical data in the veterinary dermatology literature is similar to that reported for several fields in the human medical literature. In order to reduce the likelihood of making unwarranted implications or conclusions regarding ordinal data, authors should follow established guidelines for methods of presentation and analysis of ordered categorical scales.     

Effect of Thermal Processing on Potato Sensory Profile and off-Odours Detection during Storage

One of the most used thermal treatments in potatoes to inactivate enzymes and prevent their oxidation is the boiling process. This treatment significantly decreases the taste of the potato and causes “off-odours” during storage, whatsoever, represents a big problem for the production of potato-based foodstuffs. This study focused on evaluating the sensory profile of potato slices subjected to a boiling process of three Mexican potato varieties (Alpha, Chica and Gallo) and on off-odours detection in potato produced during storage. According to the examined parameters through PanelCheck, the trained panel had a good performance, resulting 8 of the 12 attributes evaluated were significant. The formation of “cardboard-like off-odour” was detected in the Alpha and Chica varieties at the 24 and 33 h of storage, respectively. Chica potato presented this off-odours with at level significantly lower than Alpha potato (about 30% lower). With respect of Gallo variety, this presented different oxidation olfactory perceptions described by the assessors as “burnt note”, detected after 5 h of refrigerated storage. An adequate election of the variety of potato according to processing will allow an effective utilization of this vegetable and the obtention of potato-based foodstuffs much more stable.