Herd-level risk factors associated with the presence of Phage type 21/28 E. coli O157 on Scottish cattle farms

Background  

E. coli O157 is a bacterial pathogen that is shed by cattle and can cause severe disease in humans. Phage type (PT) 21/28 is a subtype of E. coli O157 that is found across Scotland and is associated with particularly severe human morbidity.     

MOTHER-INFANT SPATIAL RELATIONS IN CAPTIVE BOTTLENOSE DOLPHINS,TURSIOPS TRUNCATUS

The prolonged nursing period and strong, extended mother-infant bond observed among bottlenose dolphins may reflect social and physical ontogeny critical for infant survival. This study was conducted to quantify ontogentic changes in mother-infant contact time and the amount of time infants spent in specific spatial states with their mothers from birth to age 12 mo. These behaviors were studied through a systematic, longitudinal study of six mother-infant pairs of captive bottlenose dolphins from three different social groups. There was a significant decrease in the time infants spent with their mothers (logistic regression, P < 0.001), following the general mammalian pattern of increasing independence with age. When with their mothers, the probability that infants would be found in “echelon” position, flanking the mother, decreased as the calf aged (logistic regression, P <0.001), possibly due to anatomical and hydrodynamic factors. The probability that infants would be found in “infant” position, underneath the mother, increased with calf age (logistic regression, P < 0.001). Results obtained in this study are consistent with similar studies of wild bottlenose dolphin mother-infant pairs, indicating a suite of ontogenetically comparable behaviors between wild and captive bottlenose dolphins.     

Fertilization effects with P on accumulated leaf area duration,biomass and yield of three cultivars of maize in Toluca,Mexico

The effect of six phosphorus levels (0, 40, 80, 120, 160 and 200 kg/ha) on the duration of cumulative leaf area, biomass and agronomic yield was determined in the maize cultivars: Amarillo Almoloya, Cacahuacintle and Condor in 2010 and 2011. Such cultivars were sown in the Cerrillo Piedras Blancas Mexico. A completely randomized complete block design with factorial arrangement was utilized. High phosphorus levels (120, 160 and 200 kg/ha) positively affected the duration of cumulative leaf area; greatest values were obtained in Cacahuacintle. A greater duration of accumulated leaf area contributes to determine high values of biomass accumulation and grain yield in this cultivar. Leaf area duration appeared to be a useful tool for evaluating different genotypes in a given environment.     

Population dynamics of plant-parasite interactions: thresholds for invasion

Thresholds are derived for the invasion of plant populations by parasites. The theory is developed for a generic model that takes into account two features characteristic of plant-parasite interactions: a dual source of inoculum (infection from primary or externally introduced inoculum and secondary infection from contact between susceptible and infected host tissue) and a host response to infection load. Each of the threshold criteria is shown to be the sum of the individual components for primary and secondary infection. This indicates that if parasite invasion is not possible through primary or secondary infection alone, when the two modes of transmission are combined, the parasite may be able to invade. The invasion criteria demonstrate that there is a threshold population of susceptible hosts below which the parasite is unable to invade. If there are nonlinearities in the population dynamics (arising through either the transmission process or the host response), there are also threshold densities for the infected hosts and parasite populations below which invasion does not occur. The implications of the results for the control of plant disease are discussed.     

The predictive value of transcranial duplex sonography for the clinical diagnosis in undiagnosed parkinsonian syndromes: comparison with SPECT scans

Background  

Transcranial duplex sonography (TCD) of the substantia nigra has emerged as a promising, non-invasive tool to diagnose idiopathic Parkinson's disease (IPD). However, its diagnostic accuracy in patients with undefined parkinsonism remains to be determined.     

Construction and analysis of recombinant DNAs containing a structural gene for rat prolactin.

Poly A-containing RNA enriched in prolactin-coding sequences was isolated from female rate pituitaries after induction with diethylstilbesterol. Double stranded cDNA was synthesized from this RNA and inserted into plasmid pBR322 at the Pst I site via the poly(dG):polyy(dC) tailing method. E. coli was transformed with this DNA and the recombinant plasmid in one of the transformants characterized in detail. About half of its 900 base pair cDNA insert was sequenced. The DNA sequence is consistent with most of the reported amino acid sequence of rat preprolactin. In addition, the recombinant plasmids in two of the other transformants appear to contain growth hormone coding sequences.     

The importance of fine‐scale predictors of wild boar habitat use in an isolated population

1. Predicting the likelihood of wildlife presence at potential wildlife–livestock interfaces is challenging. These interfaces are usually relatively small geographical areas where landscapes show large variation over small distances. Models of wildlife distribution based on coarse data over wide geographical ranges may not be representative of these interfaces. High‐resolution data can help identify fine‐scale predictors of wildlife habitat use at a local scale and provide more accurate predictions of species habitat use. These data may be used to inform knowledge of interface risks, such as disease transmission between wildlife and livestock, or human–wildlife conflict.
2. This study uses fine‐scale habitat use data from wild boar (Sus scrofa) based on activity signs and direct field observations in and around the Forest of Dean in Gloucestershire, England. Spatial logistic regression models fitted using a variant of penalized quasi‐likelihood were used to identify habitat‐based and anthropogenic predictors of wild boar signs.
3. Our models showed that within the Forest of Dean, wild boar signs were more likely to be seen in spring, in forest‐type habitats, closer to the center of the forest and near litter bins. In the area surrounding the Forest of Dean, wild boar signs were more likely to be seen in forest‐type habitats and near recreational parks and less likely to be seen near livestock.
4. This approach shows that wild boar habitat use can be predicted using fine‐scale data over comparatively small areas and in human‐dominated landscapes, while taking account of the spatial correlation from other nearby fine‐scale data‐points. The methods we use could be applied to map habitat use of other wildlife species in similar landscapes, or of movement‐restricted, isolated, or fragmented wildlife populations.

     

Immune responses in pigs vaccinated with adjuvanted and non-adjuvanted A(H1N1)pdm/09 influenza vaccines used in human immunization programmes

Following the emergence and global spread of a novel H1N1 influenza virus in 2009, two A(H1N1)pdm/09 influenza vaccines produced from the A/California/07/09 H1N1 strain were selected and used for the national immunisation programme in the United Kingdom: an adjuvanted split virion vaccine and a non-adjuvanted whole virion vaccine. In this study, we assessed the immune responses generated in inbred large white pigs (Babraham line) following vaccination with these vaccines and after challenge with A(H1N1)pdm/09 virus three months post-vaccination. Both vaccines elicited strong antibody responses, which included high levels of influenza-specific IgG1 and haemagglutination inhibition titres to H1 virus. Immunisation with the adjuvanted split vaccine induced significantly higher interferon gamma production, increased frequency of interferon gamma-producing cells and proliferation of CD4(-)CD8(+) (cytotoxic) and CD4(+)CD8(+) (helper) T cells, after in vitro re-stimulation. Despite significant differences in the magnitude and breadth of immune responses in the two vaccinated and mock treated groups, similar quantities of viral RNA were detected from the nasal cavity in all pigs after live virus challenge. The present study provides support for the use of the pig as a valid experimental model for influenza infections in humans, including the assessment of protective efficacy of therapeutic interventions.     

Dexamethasone induces gelsolin synthesis and altered morphology in L929 cells

When L929 cells are exposed to 5 μg/ml dexamethasone, synthesis of a 90,000 M(r) polypeptide is induced within 12 h. Flattening of the cells begins at about this time and progresses to become quite prominent after 48 h of exposure. Two-dimensional PAGE and partial proteolytic fingerprints identify the 90,000 M(r) polypeptide as gelsolin, a Ca(++)-dependent inhibitor of actin polymerization. Thus, this system provides evidence that gelsolin may have a role in regulating cell shape in response to physiological agents such as glucocorticoids.