Evolving perceptions of bluetongue: A challenge for government and industry

From the first discovery of bluetongue virus activity in Canada in the Okanagan Valley of British Columbia in 1976 to the present, more than 175,000 sera from cattle in Canada have been tested for the presence of bluetongue antibody during the course of disease investigations and during regional or national surveys. Serological reactors have been detected only in cattle resident in the Okanagan Valley or in those originating in the United States.

Despite the regional nature of the distribution of antibody to bluetongue, international trade sanctions were applied on a nationwide basis. The strategy of the federal government for limiting the international, as well as the domestic, impact of bluetongue has evolved over the past 15 years as the epizootiology of bluetongue has become better understood. This new information is also ameliorating somewhat international attitudes toward nations which experience infections.

     

Formation of Chiral Interdigitated Multilayers at the Air-Liquid Interface Through Acid-Base Interactions

Thin interdigitated films composed of a long-chain, water-insoluble chiral acid (p-pentadecylmandelic acid of absolute configuration R) and a water-soluble chiral base (phenylethylamine, R') were constructed at the air-solution interface. The (R, R') structure was characterized to near-atomic resolution by grazing-incidence x-ray diffraction (GIXD). The two diastereomeric systems, (R, R') and (R, S'), demonstrate similar surface pressure-molecular area isotherms, but their structures are completely different on the molecular level, as monitored by GIXD. Complementary data on these two architectures were provided by atomic force microscopy.     

The need to implement the landscape of fear within rodent pest management strategies

Current reactive pest management methods have serious drawbacks such as the heavy reliance on chemicals, emerging genetic rodenticide resistance and high secondary exposure risks. Rodent control needs to be based on pest species ecology and ethology to facilitate the development of ecologically based rodent management (EBRM). An important aspect of EBRM is a strong understanding of rodent pest species ecology, behaviour and spatiotemporal factors. Gaining insight into the behaviour of pest species is a key aspect of EBRM. The landscape of fear (LOF) is a mapping of the spatial variation in the foraging cost arising from the risk of predation, and reflects the levels of fear a prey species perceives at different locations within its home range. In practice, the LOF maps habitat use as a result of perceived fear, which shows where bait or traps are most likely to be encountered and used by rodents. Several studies have linked perceived predation risk of foraging animals with quitting‐harvest rates or giving‐up densities (GUDs). GUDs have been used to reflect foraging behaviour strategies of predator avoidance, but to our knowledge very few papers have directly used GUDs in relation to pest management strategies. An opportunity for rodent control strategies lies in the integration of the LOF of rodents in EBRM methodologies. Rodent management could be more efficient and effective by concentrating on those areas where rodents perceive the least levels of predation risk. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Effect of body condition score and reuse of progesterone‐releasing intravaginal devices on conception rate following timed artificial insemination in Nelore cows

This study had the aim of investigating the efficiency of timed artificial insemination (TAI) through the progesterone‐releasing intravaginal device (PRID), used in new condition and for the second and third times in Nelore cows. The effects of device reuse and body condition score (BCS) on the conception rate (CR) were evaluated in 1,122 multiparous Nelore cows (mean BCS of 2.7 ± 0.4), which were randomly distributed into three groups that received new (n = 330), once (n = 439) and twice used (n = 353) PRID. Among the 1,122 females that underwent TAI, 573 became pregnant, thus representing an overall CR of 51.06%. Cows with BCS between 2.75 and 4.0 had greater (p < .0001) CR (69.75%) than cows with BSC of 2.0–2.5 (32.98%). It was observed that the CR through using PRID was 60.00%, 51.71% and 41.93% for new, once and twice used PRID, respectively, with difference between all groups (p < .0001). Under tropical conditions, animals with BCS greater than 2.5 had a higher CR, and the CR decreased proportionally with the number of times that the PRID had been used.     

Evaluation of Efficacy and Safety of Zinc Gluconate Associated with Dimethyl Sulphoxide for Sexually Mature Canine Males Chemical Neutering

The aim of this research was to evaluate the efficacy of zinc gluconate associated with dimethyl sulphoxide (DMSO) for chemical neutering in canine males. Fifteen sexually mature male dogs were divided in two groups, named control and treated. An injection was administered to both testicles, at a concentration of 26.2 mg zinc gluconate per ml and 0.5% DMSO in the treated group (11 dogs). The control group was given injections of saline solution (four dogs). Clinical examination and blood collection for a haemogram were done both before and after drug injection. There were 12 spermograms performed to analyse sperm motility, sperm vigour, ejaculate volume, testicle size, pathology and sperm concentrations. Libido was also measured. An ultrasound examination and histopathology were performed at the end of the experiment. Dogs’ libido after chemical injection was reduced by over 50%. The spermogram analysis showed final mean results of 14.54% for sperm motility, 0.72 of sperm vigour and 37 150 per million spermatozoa per millilitre, values considered below the necessary levels at which fertilization can occur. Ultrasound and histopathology analyses of testicles for the treated group revealed more intense injuries when compared with the control group, with compromised testicular parenchyma and a decrease of germ cell number leading to total atrophy, indicating that the treatment reduced the fertilizing potential of male dogs, promoting a possible subfertile status.     

Concentrations of heavy metals in forty sewage sludges in England

Samples of forty sewage sludges taken in England during 1979 were analysed for ten heavy metals using a rapid flameless atomic absorption spectroscopic technique. For all metals the mean concentrations were influenced by a small number of sludges containing exceptionally high concentrations. Typically, the concentration ranges showed approximately a 100-fold spread. Calculations based on U.K. guidelines for limiting the addition of toxic metals in sludge to agricultural soils indicated that application rates would theoretically be limited for more than 75 % of the sludges by the concentrations of Zn, Cu and Ni, expressed additively as the Zn equivalent. Calculations of the theoretical maximum quantities of sludges which could be applied to land on an annual basis suggested that a significant proportion of the sludges would be unsuitable for application to agricultural land at rates of more than 2 t ha^?1 yr^?1     

The kondo effect in the unitary limit

We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect, and the conductance reaches the unitary limit value. We compare the experimental Kondo temperature with the theoretical predictions for the spin- 12 Anderson impurity model. Excellent agreement is found throughout the Kondo regime. Phase coherence is preserved when a Kondo quantum dot is included in one of the arms of an Aharonov-Bohm ring structure, and the phase behavior differs from previous results on a non-Kondo dot.     

The influence of flow conditions on the removal of heavy metals in the primary sedimentation process

A pilot scale primary sedimentation pilot plant, treating raw sewage, was used to assess the efficiency of removal of Cd, Cr, Cu, Ni, Pb, and Zn. Heavy metal removals were determined during conditions designed to simulate normal dry weather flow, three times dry weather flow and diurnal variations in flow. During these experiments, the flow of sewage to the works where the pilot plant was sited also varied. It was found that short term variations in heavy metal concentrations in the raw sewage were related to the flow, although percentage removals appeared to be relatively unaffected by heavy metal concentrations. Removals during normal dry weather flow conditions were generally in the range of 25 to 50%, with Cu and Pb removals highest and Ni removal lowest. Lower removal efficiencies were observed when the flow to the pilot plant was increased three-fold, and the poorest removals were observed under variable flow conditions.     

The speciation of metals in sewage and activated sludge effluent

A gel filtration chromatography technique was used to separate soluble species of Cd, Cu, Co, Mn, Ni, and TI in the influent and effluent of a laboratory scale activated sludge simulation operated at a range of sludge ages from 3 to 18 days. It was found that, whilst there was no general trend for all six metals, Cd and Mn associated mainly with low molecular weight fractions; Co, Cu, and Ni with a range of predominantly high molecular weight fractions; and TI tended towards association with high molecular weight fractions which influenced metal solubility and appeared to be significant in determining metal removal. It appeared that all metals exhibited high affinity for mixed liquor suspended solids (MLSS) and that this affinity was strongest for Cu and Cd. Nickel, Co, Cu, and TI appeared to show a high affinity for polymeric microbial products produced at longer sludge ages. The gel filtration technique was found to be useful in the separation of metal species in conjunction with a sufficiently sensitive detector provided their concentrations in the original sample were relatively high.