80 research outputs found
Unidentified Woman 40 [reverse]
No full texthttps://digitalarchives.apu.edu/barfield-images/1446/thumbnail.jp
Urinary felinine excretion in intact male cats is increased by dietary cystine
No full textFelinine is a branched-chain sulfur amino acid present in the urine of certain Felidae, including domestic cats. The objective of the present study was to determine if additional cystine and/or dietary N would increase felinine and N-acetylfelinine excretion by intact male cats fed a low-protein (LP) diet. Feeding five adult intact male cats an LP diet (18·8% of metabolisable energy (ME) as protein) v. a high-protein diet (38·6% of ME as protein) resulted in a trend (P¼0·08) for decreased urinary felinine and no change in N-acetylfelinine excretion. In a 23 d study, when the LP diet was supplemented with L-cystine at 9·3 g/kg DM, urinary felinine:creatinine ratio showed a linear two-fold (121 %) increase (P,0·01) from 0·24 (SEM 0·05) to 0·53 (SEM 0·13) after 10 d. Subsequent feeding of the LP diet resulted in a decrease in felinine excretion to base levels. Plasma gglutamylfelinylglycine concentrations were consistent with the excretion of felinine. Supplementation of the LP diet with L-cystine (9·3 g/kg DM), dispensable amino acids and arginine to a second group (n 5) also resulted in a significant (P,0·01) but smaller (þ72 %) increase in the daily felinine:creatinine ratio (0·25 (SEM 0·04) to 0·43 (SEM 0·05)). The degree of felinine N-acetylation within groups was unaffected by dietary addition and withdrawal of amino acids. The results indicate that felinine synthesis is regulated by cystine availability, and that arginine may be physiologically important in decreasing felinine biosynthesis in intact male cats
The Effect of a 14-Day gymnema sylvestre Intervention to Reduce Sugar Cravings in Adults
No full textGymnemic-acids (GA) block lingual sweet taste receptors, thereby reducing pleasantness and intake of sweet food. Objective: To examine whether a 14-day gymnema-based intervention can reduce sweet foods and discretionary sugar intake in free-living adults. Healthy adults (n = 58) were randomly allocated to either the intervention group (INT) or control group (CON). The intervention comprised of consuming 4 mg of Gymnema sylvestre containing 75% gymnema acids, a fibre and vitamin supplement, and an associated healthy-eating guide for 14 days; participants in the CON group followed the same protocol, replacing the GA with a placebo mint. Amount of chocolate bars eaten and sensory testing were conducted before and after the 14-day intervention (post-GA or placebo dosing on days zero and 15, respectively). Food frequency questionnaires were conducted on days zero, 15 and after a 28-day maintenance period to examine any changes in intake of sweet foods. A range of statistical procedures were used to analyse the data including Chi square, t-test and two-way analysis of variance. Post dosing, INT consumed fewer chocolates (2.65 ± 0.21 bars) at day zero than CON (3.15 ± 0.24 bars; p = 0.02); there were no differences between groups at day 15 (INT = 2.77 ± 0.22 bars; CON = 2.78 ± 0.22 bars; p = 0.81). At both visits, a small substantive effect (r < 0.3) was observed in the change in pleasantness and desire ratings, with INT showing a slight increase while CON showed a small decrease over the 14-day period. No differences were found in the intake of 9 food categories between groups at any timepoint. There were no differences in consumption of low sugar healthy foods between visits, or by group. The 14-day behavioural intervention reduced pleasantness and intake of chocolate in a laboratory setting. There was no habituation to the mint over the 14-day period. This study is the first to investigate the effect of longer-term gymnema acid consumption on sweet food consumption outside of a laboratory setting; further research is needed to assess how long the effect of the 14-day intervention persists
Extremely red stellar objects revealed by IPHAS
Full text linkWe present photometric analysis and follow-up spectroscopy for a population of extremely red stellar objects extracted from the point-source catalogue of the Isaac Newton Telescope (INT) Photometric H alpha Survey (IPHAS) of the northern Galactic plane. The vast majority of these objects have no previous identification. Analysis of optical, near- and mid-infrared photometry reveals that they are mostly highly reddened asymptotic giant branch stars, with significant levels of circumstellar material. We show that the distribution of these objects traces galactic extinction, their highly reddened colours being a product of both interstellar and circumstellar reddening. This is the first time that such a large sample of evolved low-mass stars has been detected in the visual and allows optical counterparts to be associated with sources from recent infrared surveys.
Follow-up spectroscopy on some of the most interesting objects in the sample has found significant numbers of S-type stars which can be clearly separated from oxygen-rich objects in the IPHAS colour-colour diagram. We show that this is due to the positions of different molecular bands relative to the narrow-band H alpha filter used for IPHAS observations. The IPHAS (r' - H alpha) colour offers a valuable diagnostic for identifying S-type stars. A selection method for identifying S-type stars in the Galactic plane is briefly discussed and we estimate that over a thousand new objects of this type may be discovered, potentially doubling the number of known objects in this short but important evolutionary phase
New Frontiers in Characterizing Structure and Dynamics by NMR
No full textNuclear Magnetic Resonance (NMR) spectroscopy has emerged as the method of choice for studying both the structure and the dynamics of biological macromolecule in solution. Despite the maturity of the NMR method for structure determination, its application faces a number of challenges. The method is limited to systems of relatively small molecular mass, data collection times are long, data analysis remains a lengthy procedure, and it is difficult to evaluate the quality of the final structures. The last years have seen significant advances in experimental techniques to overcome or reduce some limitations. The function of bio-macromolecules is determined by both their 3D structure and conformational dynamics. These molecules are inherently flexible systems displaying a broad range of dynamics on timescales from picoseconds to seconds. NMR is unique in its ability to obtain dynamic information on an atomic scale. The experimental information on structure and dynamics is intricately mixed. It is however difficult to unite both structural and dynamical information into one consistent model, and protocols for the determination of structure and dynamics are performed independently. This chapter deals with the challenges posed by the interpretation of NMR data on structure and dynamics. We will first relate the standard structure calculation methods to Bayesian probability theory. We will then briefly describe the advantages of a fully Bayesian treatment of structure calculation. Then, we will illustrate the advantages of using Bayesian reasoning at least partly in standard structure calculations. The final part will be devoted to interpretation of experimental data on dynamics
Normativity and law
No full textAn action's illegality can be irrelevant to a reason not to perform it. A plausible
example of a reason not to assault is that assault causes suffering. Since assault
is illegal, the reason pertains to a legally proscribed action. Still, assault's
illegality is irrelevant in this case: the reason would pertain (assault would cause
suffering; we would have reason not to assault) even if assault were not legally
proscribed.
On the other hand, it appears that a reason can be one that derives from
the interposition of law. This thesis is about reasons of this second type (legal
reasons). In particular, it is about their formal features. For example, it is about
their individuating conditions (when are p and q two legal reasons rather than
one?) and about how legal reasons can be second-order rather than first-order
(what follows when p is a reason not to have another reason figure in
deliberation about action?). Most particularly, however, it is about their identity
conditions (if p is a reason, when and only when is p a legal reason?).
I argue against three widely-accepted claims about the nature of legal
reasons: (i) p is a legal reason only if p is a content-independent reason (chapters
5 and 6); (ii) if p is a legal reason to ¢, p could be a complete reason to ¢ or a
part of a complete reason to ¢ (chapters 2, 3 and 4); (iii) a legal reason p has a
significant formal feature when p is an exclusionary reason (chapter 8). I also
argue that one argument to the conclusion that analytical jurisprudence must pay
special to attention moral legal reasons - an argument seen in recent work by R.
A. Duff - is unconvincing (chapter 7)
Choice of antipsychotic treatment by European psychiatry trainees: are decisions based on evidence?
Full text linkBackground: Little is known about the factors influencing treatment choice in psychosis, the majority of this work being conducted with specialists (consultant) in psychiatry. We sought to examine trainees' choices of treatment for psychosis if they had to prescribe it for themselves, their patients, and factors influencing decision-making.
<p/>Methods: Cross-sectional, semi-structured questionnaire-based study.
<p/>Results: Of the 726 respondents (response rate = 66%), the majority chose second-generation antipsychotics (SGAs) if they had to prescribe it for themselves (n = 530, 93%) or for their patients (n = 546, 94%). The main factor influencing choice was perceived efficacy, 84.8% (n = 475) of trainees stating this was the most important factor for the patient, and 77.8% (n = 404) stating this was the most important factor for their own treatment. Trainees with knowledge of trials questioning use of SGAs (CATIE, CUtLASS, TEOSS) were more likely to choose second-generation antipsychotics than those without knowledge of these trials (χ2 = 3.943; p = 0.047; O.R. = 2.11; 95% C.I. = 1.0-4.48). Regarding psychotherapy, cognitive behavioural therapy (CBT) was the most popular choice for self (33.1%; n = 240) and patient (30.9%; n = 224). Trainees were significantly more likely to prefer some form of psychotherapy for themselves rather than patients (χ2 = 9.98; p < 0,002; O.R. = 1.54; 95% CIs = 1.18-2.0).
<p/>Conclusions: Trainees are more likely to choose second-generation antipsychotic medication for patients and themselves. Despite being aware of evidence that suggests otherwise, they predominantly base these choices on perceived efficacy
Novel Biopesticides Based on Recombinant Avidin for Protection of Crops Against Insect Pests
Full text linkFarmers are required to increase their food productivity to meet the demand from a continually enlarging population. A major constraint on meeting this requirement is the damage created by insect pests. Agricultural pests and associated diseases destroy 30%-40% of the world’s crop produce. The withdrawal of broad-spectrum chemical insecticides, the threat of the development of resistance in insect pests to remaining compounds and the possibility of new pest species spreading into the UK as a result of environmental change have prompted research into alternative pesticides.
Protein-based insecticides offer the possibility of producing compounds that are specific to pest species and environmentally benign. The production of orally active insecticidal fusion proteins, containing toxins from Segestria florentina (tube-web spider) or Mesobuthus tamulus (Indian red scorpion) fused to a ‘carrier’ protein (snowdrop lectin; Galanthus nivalis agglutinin; GNA) which transports them across the insect gut epithelium, has shown that recombinant protein expression systems and protein engineering techniques can be used to produce novel insecticidal proteins. The main aim of the work described in this thesis is to extend this technology.
Avidin, a biotin-binding protein known to be insecticidal, was evaluated as a possible ‘carrier’ protein. Recombinant avidin was produced in high yields using Pichia pastoris and was compared to the native egg white protein. Recombinant avidin has insecticidal activity towards hemipteran plant pests. It was highly toxic to Acyrthosiphon pisum (pea aphid) when fed in liquid artificial diet, causing 100% mortality after four days when present at concentrations ≥0.25mg/ml (250ppm). The toxicity towards A. pisum was prevented by biotin supplementation of the diet. In contrast, recombinant avidin had no significant effects on the survival of Sitobion avenae (cereal aphid) at concentrations up to 2mg/ml (2000ppm) in liquid diet. Analysis of genomic DNA showed that symbionts from both aphid species lack the ability to synthesise biotin de novo. Cereal aphids appear to be less sensitive to sub-optimal levels of biotin and possess a more effective system for scavenging biotin from recombinant avidin in the diet.
Avidin is readily transported to the haemolymph of lepidopteran larvae after feeding, which suggested that it might replace GNA in synthetic insecticidal fusion proteins. Numerous attempts were made to produce a fully functional insecticidal avidin-based fusion protein containing scorpion or spider toxins by expression as recombinant proteins in P. pastoris but, following tests against Mamestra brassicae (cabbage moth) larvae, the fusion proteins were found to be non-toxic. The lack of toxicity was most likely due to incorrect folding of the toxin component of the fusion, since the avidin component was functional.
Avidin fed to A. pisum was found to bind to the stomach region of the gut after ingestion and was retained for at least 72 hours. Feeding conjugates of avidin with fluorescently labelled biotin, or a fluorescently labelled, biotinylated peptide, showed that the conjugated compound was also retained in the aphid gut after feeding. A conjugate between avidin and biotinylated leucomyosuppressin (LMS), a myoinhibitory peptide hormone that affects gut contractions in insects, was prepared and fed to aphids. The avidin : biotin-LMS conjugate had insecticidal activity towards A. pisum when fed in diet at levels which neither of the components (avidin or biotin-LMS) caused significant mortality. It was hypothesised that binding to the gut, through the avidin moiety, was responsible for the observed oral toxicity of the avidin : biotin-LMS conjugate. The same principle was applied to lepidopteran larvae. A conjugate between avidin and biotinylated allatostatin was prepared and fed to M. brassicae larvae. The avidin : biotin-allatostatin was non-toxic, most likely due to cleavage between the biotin molecule and allatostatin as a result of the high levels of gut proteolysis in lepidoptera. Avidin conjugates of peptides that have little or no oral toxicity to insects, as a result of restricted access to sites of action, could have the potential to form a novel class of insecticidal compounds
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