11,376 research outputs found
Characteristics of ex-racing greyhounds in New Zealand and their impact on re-homing
A small proportion of greyhounds surplus to the racing industry are entered into specialist rehoming organisations to be re-purposed as pets. Records of 835 greyhounds, from New Zealand Greyhounds as Pets (GAP), were used to investigate whether pre-adoption characteristics (age, sex, racing record, reason entered) and management factors (temperament test result, foster and trainer effects) had a bearing on rehoming success, and comparisons were made with shelter studies. Rehoming greyhounds as pets is very successful with 85.5% ultimately successfully rehomed. Only 2.9% fail as a result of failed adoptions, 11.6% fail the initial temperament test. Greyhounds were more likely than shelter dogs to pass an initial temperament test and be adopted, and less likely to be returned after 1 month. However, adopted greyhounds were just as likely as shelter dogs to be returned after 6 months. Logistic regression revealed the youngest age group (< 24 months old) were more likely to pass the initial temperament test than older greyhounds. This age effect was not detectable when the adoption success of dogs subsequently available for rehoming was considered, but a sex effect was evident with females more likely to be successfully adopted than males. Whether or not a dog had raced had no significant effect on the likelihood of successful rehoming. Greyhounds passing the temperament test with a basic pass, were less likely to be successfully rehomed than greyhounds scoring a higher pass indicative of lower prey drive. Further investigation of the validity and reliablity of the temperament test is warranted
Discovery-led refinement in e-discovery investigations: sensemaking, cognitive ergonomics and system design.
Given the very large numbers of documents involved in e-discovery investigations, lawyers face a considerable challenge of collaborative sensemaking. We report findings from three workplace studies which looked at different aspects of how this challenge was met. From a sociotechnical perspective, the studies aimed to understand how investigators collectively and individually worked with information to support sensemaking and decision making. Here, we focus on discovery-led refinement; specifically, how engaging with the materials of the investigations led to discoveries that supported refinement of the problems and new strategies for addressing them. These refinements were essential for tractability. We begin with observations which show how new lines of enquiry were recursively embedded. We then analyse the conceptual structure of a line of enquiry and consider how reflecting this in e-discovery support systems might support scalability and group collaboration. We then focus on the individual activity of manual document review where refinement corresponded with the inductive identification of classes of irrelevant and relevant documents within a collection. Our observations point to the effects of priming on dealing with these efficiently and to issues of cognitive ergonomics at the human–computer interface. We use these observations to introduce visualisations that might enable reviewers to deal with such refinements more efficiently
Hydrologie and biotic influences on nitrate removal in a subtropical spring-fed river
We use a long-term chemical and hydrologic record in combination with longitudinal sampling and highfrequency nitrate (NO3-) measurements from in situ sensors to describe temporal and spatial patterns of nitrogen (N) inputs and removal in the spring-fed Ichetucknee River (Columbia County, Florida) and to determine the hydrological, geomorphic, and biological factors that influence those dynamics. Over a 20-yr period of record, NO 3-N removal averaged 118 kg N d-1 (0.77 g N m-2 d-1 ) over the upper 5 km of the Ichetucknee River. Three independent estimates of gross autotrophic N assimilation (from gross primary production, diel NO3- variation, and standing biomass) agreed closely but accounted for less than 20% of observed N removal. Longitudinal surveys indicate negligible or negative dissolved organic nitrogen and ammonium (NH4+) production, suggesting that denitrification is the predominant mechanism of N removal in this river. A positive relationship between discharge and the magnitude of NO3-N removal shows that interactions with the surrounding floodplain exert considerable influence at high flows, and longitudinal NO3- patterns indicate that N removal may be influenced by channel morphology. These results suggest a greater role for dissimilatory processes and hydrologic connectivity with hyporheic and floodplain sediments than has been previously recognized in highly productive spring-fed rivers of north Florida. While hydrologic variation is the primary determinant of variation in NO 3- removal within the Ichetucknee River, comparison across systems indicates that biotic characteristics can cause significant deviation from predictions based on purely physical models of relationships between river size and N removal. © 2010 by the American Society of Limnology and Oceanography, Inc
Phase Stability Control of Interstitial Oxide Ion Conductivity in the La1+xSr1-xGa3O7+x/2 Melilite Family
A pentapeptide as minimal antigenic determinant for MHC class I-restricted T lymphocytes
Peptides that are antigenic for T lymphocytes are ligands for two receptors, the class I or II glycoproteins that are encoded by genes in the major histocompatibility complex, and the idiotypic / chain T-cell antigen receptor1–9. That a peptide must bind to an MHC molecule to interact with a T-cell antigen receptor is the molecular basis of the MHC restriction of antigen-recognition by T lymphocytes10,11. In such a trimolecular interaction the amino-acid sequence of the peptide must specify the contact with both receptors: agretope residues bind to the MHC receptor and epitope residues bind to the T-cell antigen receptor12,13. From a compilation of known antigenic peptides, two algorithms have been proposed to predict antigenic sites in proteins. One algorithm uses linear motifs in the sequence14, whereas the other considers peptide conformation and predicts antigenicity for amphipathic -helices15,16. We report here that a systematic delimitation of an antigenic site precisely identifies a predicted pentapeptide motif as the minimal antigenic determinant presented by a class I MHC molecule and recognized by a cytolytic T lymphocyte clone
Historic landmarks in clinical transplantation: Conclusions from the consensus conference at the University of California, Los Angeles
The transplantation of organs, cells, and tissues has burgeoned during the last quarter century, with the development of multiple new specialty fields. However, the basic principles that made this possible were established over a three-decade period, beginning during World War II and ending in 1974. At the historical consensus conference held at UCLA in March 1999, 11 early workers in the basic science or clinical practice of transplantation (or both) reached agreement on the most significant contribution of this era that ultimately made transplantation the robust clinical discipline it is today. These discoveries and achievements are summarized here is six tables and annotated with references
Lithium distribution across the membrane of motoneurons in the isolated frog spinal cord
Lithium sensitive microelectrodes were used to investigate the transmembrane distribution of lithium ions (Li+) in motoneurons of the isolated frog spinal cord. After addition of 5 mmol·l–1 LiCl to the bathing solution the extracellular diffusion of Li+ was measured. At a depth of 500 m, about 60 min elapsed before the extracellular Li+ concentration approached that of the bathing solution. Intracellular measurements revealed that Li+ started to enter the cells soon after reaching the motoneuron pool and after up to 120 min superfusion, an intra — to extracellular concentration ratio of about 0.7 was obtained. The resting membrane potential and height of antidromically evoked action potentials were not altered by 5 mmol·l–1 Li+
Biocide exposure induces changes in susceptibility, pathogenicity and biofilm formation in Uropathogenic Escherichia coli
Background: Uropathogenic Escherichia coli (UPEC) are a frequent cause of catheter associated urinary tract infection (CAUTI). Biocides have been incorporated into catheter-coatings to inhibit bacterial colonisation whilst ideally exhibiting low cytotoxicity and mitigating the selection of resistant bacterial populations. We compared the effects of long-term biocide exposure on susceptibility, biofilm-formation and relative-pathogenicity in eight UPEC isolates.Methods: Minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), minimum biofilm eradication concentrations (MBEC) and antibiotic susceptibilities were determined before and after long-term exposure to triclosan, polyhexamethylene biguanide (PHMB), benzalkonium chloride (BAC) and silver nitrate. Biofilm-formation was quantified using a crystal violet assay and relative-pathogenicity was assessed via a Galleria mellonella waxworm model. Cytotoxicity and resulting biocompatability index values were determined against an L929 murine fibroblast cell line.Results: Biocide exposure resulted in multiple decreases in biocide susceptibility in planktonic and biofilm associated UPEC. Triclosan exposure induced the largest frequency and magnitude of susceptibility decreases at MIC, MBC and MBEC, which correlated to an increase in biofilm biomass in all isolates. Induction of antibiotic-cross-resistance occurred in 6/84 possible combinations of bacteria, biocide and antibiotic. Relative-pathogenicity significantly decreased after triclosan exposure (5/8 isolates), increased after silver nitrate exposure (2/8 isolates) and varied between isolates for PHMB and BAC. Biocompatibility index ranked antiseptic potential as PHMB>triclosan>BAC>silver nitrate.Conclusion: Biocide exposure in UPEC may lead to reductions in biocide and antibiotic susceptibility, changes in biofilm-formation and alterations relative-pathogenicity. These data indicate the multiple consequences of biocide adaptation that should be considered when selecting an anti-infective catheter-coating agent
Ruthenacycles and Iridacycles as Catalysts for Asymmetric Transfer Hydrogenation and Racemisation
Ruthenacycles, which are easily prepared in a single step by reaction between enantiopure aromatic amines and [Ru(arene)Cl2]2 in the presence of NaOH and KPF6, are very good asymmetric transfer hydrogenation catalysts. A range of aromatic ketones were reduced using isopropanol in good yields with ee’s up to 98%. Iridacycles, which are prepared in similar fashion from [IrCp*Cl2]2 are excellent catalysts for the racemisation of secondary alcohols and chlorohydrins at room temperature. This allowed the development of a new dynamic kinetic resolution of chlorohydrins to the enantiopure epoxides in up to 90% yield and 98% enantiomeric excess (ee) using a mutant of the enzyme Haloalcohol dehalogenase C and an iridacycle as racemisation catalyst.
Visual ecology of aphids – a critical review on the role of colours in host finding
We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms.
Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region.
We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours
that are not likely to hold. Finally we also discuss the
implications for developing and optimising strategies
of aphid control and monitoring
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