Reported Acquisition Practices of Australian Dog Owners

In Australia, the UK and the US dog ownership is prevalent with an estimated 40% ofAustralian households, 25% of UK households, and 50% of US households owning a dog. Onceacquired, a dog usually becomes a family companion so, unlike a faulty product, it can rarely bereturned or resold without some emotional impact on both the acquirer and the dog. Regarding thereality of dog relinquishment, there is a growing need for cross-disciplinary research that considershow dog owners are making their acquisition choices and, if prioritising different attributes, leads tomore optimal acquisition choices. This research collected data from 2840 dog owners via an onlinesurvey and examines how owners prioritised various attributes when acquiring their latest dog.The Pearson-Blotchky analysis of survey results show owners are split into two groups, with eachgroup prioritising different attributes or characteristics in their search for a new dog. The first groupare those dog owners who prioritised: the ability to rescue a dog, how compatible the dog wason the first meeting, and how compatible they believed the dog would be with their household.The second group are those owners who prioritised: a dog’s morphology, temperament predictability,and breeding practices. While each group prioritised different attributes, neither group madesubstantially more optimal acquisition choices in terms of overall satisfaction with the dog that theyultimately selected

The enhancement and suppression of immersion mode heterogeneous ice-nucleation by solutes

Heterogeneous nucleation of ice from aqueous solutions is an important yet poorly understood process in multiple fields, not least the atmospheric sciences where it impacts the formation and properties of clouds. In the atmosphere ice-nucleating particles are usually, if not always, mixed with soluble material. However, the impact of this soluble material on ice nucleation is poorly understood. In the atmospheric community the current paradigm for freezing under mixed phase cloud conditions is that dilute solutions will not influence heterogeneous freezing. By testing combinations of nucleators and solute molecules we have demonstrated that 0.015 M solutions (predicted melting point depression <0.1°C) of several ammonium salts can cause suspended particles of feldspars and quartz to nucleate ice up to around 3°C warmer than they do in pure water. In contrast, dilute solutions of certain alkali metal halides can dramatically depress freezing points for the same nucleators. At 0.015 M, solutes can enhance or deactivate the ice-nucleating ability of a microcline feldspar across a range of more than 10°C, which corresponds to a change in active site density of more than a factor of 105. This concentration was chosen for a survey across multiple solutes-nucleant combinations since it had a minimal colligative impact on freezing and is relevant for activating cloud droplets. Other nucleators, for instance a silica gel, are unaffected by these ‘solute effects’, to within experimental uncertainty. This split in response to the presence of solutes indicates that different mechanisms of ice nucleation occur on the different nucleators or that surface modification of relevance to ice nucleation proceeds in different ways for different nucleators. These solute effects on immersion mode ice nucleation may be of importance in the atmosphere as sea salt and ammonium sulphate are common cloud condensation nuclei (CCN) for cloud droplets and are internally mixed with ice-nucleating particles in mixed-phase clouds. In addition, we propose a pathway dependence where activation of CCN at low temperatures might lead to enhanced ice formation relative to pathways where CCN activation occurs at higher temperatures prior to cooling to nucleation temperature

Selective expansion of viral variants following experimental transmission of a reconstituted feline immunodeficiency virus quasispecies

Following long-term infection with virus derived from the pathogenic GL8 molecular clone of feline immunodeficiency virus (FIV), a range of viral variants emerged with distinct modes of interaction with the viral receptors CD134 and CXCR4, and sensitivities to neutralizing antibodies. In order to assess whether this viral diversity would be maintained following subsequent transmission, a synthetic quasispecies was reconstituted comprising molecular clones bearing envs from six viral variants and its replicative capacity compared in vivo with a clonal preparation of the parent virus. Infection with either clonal (Group 1) or diverse (Group 2) challenge viruses, resulted in a reduction in CD4+ lymphocytes and an increase in CD8+ lymphocytes. Proviral loads were similar in both study groups, peaking by 10 weeks post-infection, a higher plateau (set-point) being achieved and maintained in study Group 1. Marked differences in the ability of individual viral variants to replicate were noted in Group 2; those most similar to GL8 achieved higher viral loads while variants such as the chimaeras bearing the B14 and B28 Envs grew less well. The defective replication of these variants was not due to suppression by the humoral immune response as virus neutralising antibodies were not elicited within the study period. Similarly, although potent cellular immune responses were detected against determinants in Env, no qualitative differences were revealed between animals infected with either the clonal or the diverse inocula. However, in vitro studies indicated that the reduced replicative capacity of variants B14 and B28 in vivo was associated with altered interactions between the viruses and the viral receptor and co-receptor. The data suggest that viral variants with GL8-like characteristics have an early, replicative advantage and should provide the focus for future vaccine development

Quantifying water diffusion in high-viscosity and glassy aqueous solutions using a Raman isotope tracer method

Recent research suggests that under certain temperature and relative humidity conditions atmospheric aerosol may be present in the form of a glassy solid. In order to understand the impacts that this may have on aerosol–cloud interactions and atmospheric chemistry, knowledge of water diffusion within such aerosol particles is required. Here, a method is described in which Raman spectroscopy is used to observe D2O diffusion in high-viscosity aqueous solutions, enabling a quantitative assessment of water diffusion coefficients, Dwater, as a function of relative humidity. Results for sucrose solutions compare well with literature data at 23.5 ± 0.3 °C, and demonstrate that water diffusion is slow (Dwater ~5 × 10−17 m2 s−1), but not arrested, just below the glass transition at a water activity of 0.2. Room temperature water diffusion coefficients are also presented for aqueous levoglucosan and an aqueous mixture of raffinose, dicarboxylic acids and ammonium sulphate: at low humidity, diffusion is retarded but still occurs on millisecond to second timescales in atmospherically relevant-sized particles. The effect of gel formation on diffusion in magnesium sulfate solutions is shown to be markedly different from the gradual decrease in diffusion coefficients of highly viscous liquids. We show that using the Stokes–Einstein equation to determine diffusion timescales from viscosity leads to values which are more than 5 orders of magnitude too big, which emphasises the need to make measurements of diffusion coefficients. In addition, comparison of bounce fraction data for levoglucosan with measured diffusion data reveals that even when particles bounce the diffusion timescales for water are a fraction of a second for a 100 nm particle. This suggests a high bounce fraction does not necessarily indicate retarded water diffusion

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets

Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry

Children from Baffin Island have a disproportionate burden of tuberculosis in Canada: data from the Children's Hospital of Eastern Ontario (1998-2008)

<p>Abstract</p> <p>Background</p> <p>The Children's Hospital of Eastern Ontario (CHEO) provides services to children in Baffin Island, through the Baffin Island Pediatric Health Initiative. Tuberculosis (TB) remains a major public health problem in that region. The objective of our study was to describe the origin and clinical characteristics of patients with TB disease at CHEO, since the inception of the Baffin Island Pediatric Health Initiative.</p> <p>Methods</p> <p>All charts with a discharge diagnosis of TB disease during the first 10 years of the Baffin Island program were reviewed. Patients meeting a pre-determined case definition were included in analyses. A standard medical record abstraction form was used for patient data collection.</p> <p>Results</p> <p>Twenty patients met our case definition. Seven (35%) were Canadian-born children from Baffin Island. Seven resided in Ontario, 4 in Quebec, and 2 were visiting from other countries. All 7 children residing in Ontario were born in African countries. Endothoracic disease occurred in 16 patients (80%), including 9 with primary pulmonary TB, and 3 with sputum smear positive "adult-type" disease. Extrathoracic disease was present in 6 children (30%), including 3 with CNS disease. Three children had disease in 2 separate sites.</p> <p>Conclusions</p> <p>While Baffin Island makes up 1% of the hospital catchment population, they contributed 35% of TB patients, and the only TB death. While TB in foreign-born children is due in part to epidemics abroad, the problem in Baffin Island is a reflection of disease burden and transmission within Canada.</p

Direct monitoring of single-cell response to biomaterials by Raman spectroscopy

There is continued focus on the development of new biomaterials and associated biological testing methods needed to reduce the time taken for their entry to clinical use. The application of Raman spectroscopy to the study of individual cells that have been in contact with biomaterials offers enhanced in vitro information in a potentially non-destructive testing regime. The work presented here reports the Raman spectral analysis of discreet U-2 OS bone cells after exposure to hydroxyapatite (HA) coated titanium (Ti) substrates in both the as-deposited and thermally annealed states. These data show that cells that were in contact with the bioactive HA surface for 7 days had spectral markers similar to those cultured on the Ti substrate control for the same period. However, the spectral features for those cells that were in contact with the annealed HA surface had indicators of significant differentiation at day 21 while cells on the as-deposited surface did not show these Raman changes until day 28. The cells adhered to pristine Ti control surface showed no spectral changes at any of the timepoints studied. The validity of these spectroscopic results has been confirmed using data from standard in vitro cell viability, adhesion, and proliferation assays over the same 28-day culture period. In this case, cell maturation was evidenced by the formation of natural bone apatite, which precipitated intracellularly for cells exposed to both types of HA-coated Ti at 21 and 28 days, respectively. The properties of the intracellular apatite were markedly different from that of the synthetic HA used to coat the Ti substrate with an average particle size of 230 nm, a crystalline-like shape and Ca/P ratio of 1.63 ± 0.5 as determined by SEM-EDX analysis. By comparison, the synthetic HA particles used as a control had an average size of 372 nm and were more-rounded in shape with a Ca/P ratio of 0.8 by XPS analysis and 1.28 by SEM-EDX analysis. This study shows that Raman spectroscopy can be employed to monitor single U-2 OS cell response to biomaterials that promote cell maturation towards de novo bone thereby offering a label-free in vitro testing method that allows for non-destructive analyses. [Image: see text