565 research outputs found
Validation of the face-name pairs task in major depression: impaired recall but not recognition
Major depression can be associated with neurocognitive deficits which are believed in part to be related to medial temporal lobe pathology. The purpose of this study was to investigate this impairment using a hippocampal-dependent neuropsychological task. The face-name pairs task was used to assess associative memory functioning in 19 patients with major depression. When compared to age-sex-and-education matched controls, patients with depression showed impaired learning, delayed cued-recall, and delayed free-recall. However, they also showed preserved recognition of the verbal and nonverbal components of this task. Results indicate that the face-name pairs task is sensitive to neurocognitive deficits in major depression.Thisresearchwasfundedbya4-yearHealthResearch Board grant
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Dissociating effects of acute photic stress on spatial, episodic-like and working memory in the rat.
Adaptively responding to acute stress has been of great importance for human and animal survival. However, for our species, stress-related disorders are putting an ever-increasing burden on healthcare systems. It is thus crucial to understand the basic processes and cognitive changes associated with acute stress. Here, we examined the effects of acute stress exposure on spatial (water maze) and memory (delayed match to sample and episodic-memory-like tasks) performance. We found striking performance deficits in stressed animals navigating in the water maze. We also found, in an episodic-like memory task, striking object-location deficits, but not in temporal-object association learning in stressed animals. Finally, no differences were apparent for any delay periods (up to 30 s) in a delayed match to sample task. Taken together, these results show a strong differential effect of acute stress on differing memory processes
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Interferon-alpha-induced deficits in novel object recognition are rescued by chronic exercise
The anti-viral drug interferon-alpha (IFN-alpha) is widely-known to induce psychiatric and cognitive effects in patients. Previous work has shown that physical exercise can have a positive effect against brain insult. We investigated the effects of a clinically-comparable treatment regime of IFN-alpha on cognitive function in male Wistar rats and assessed the impact of chronic treadmill running on the deficits generated by IFN-alpha. We found that IFN-alpha induced significant impairments in performance on both spatial novelty and object novelty recognition. Chronic forced exercise did not protect against IFN-alpha-induced learning deficits in reactivity to spatial change, but did restore the capacity for novel object recognition in IFN-alpha-treated animals
Self broadening of hydrogen lines: Initial results
For the first time broadening by both resonance and dispersive-inductive interactions with H-atoms are included in the formation of Balmer lines in cool stars, without the use of a multipole expansion. Comparison of synthetic profiles with observed profiles for the Sun and two late F dwarfs shows that this improvement in broadening theory accounts for some of the problems found in previous work. It is anticipated that planned future developments in the theory of self broadening will lead to further improve ments in the modelling of cool star atmospheres
Self-broadening in Balmer line wing formation in stellar atmospheres
Details of a theory of self-broadening of hydrogen lines are presented. The main features of the new theory are that the dispersive-inductive components of the interaction (van der Waals forces) have been included, and the resonance components have been computed by perturbation theory without the use of the multipole expansion. The theory is applied to lower Balmer lines and the theoretical and observational impact of the new broadening theory is examined. It is shown that this theory leads to considerable differences in the predicted line profiles in cool stars when compared with previous theories which include only resonance interactions. In particular, the effect is found to be very important in metal poor stars. The theory provides a natural explanation for the behaviour of effective temperatures derived from Balmer lines by others using a theory which includes only resonance broadening. When applied to Balmer lines in the solar spectrum the theory predicts an improved agreement between observed and computed profiles for models which also match limb darkening curves and rules out a model which does not. However significant discrepancies still remain which could be due to inadequacies in our theory or the atmospheric model or both
Comments on alternative calculations of the broadening of spectral lines of neutral sodium by H-atom collisions
With the exception of the sodium D-lines recent calculations of line
broadening cross-sections for several multiplets of sodium by Leininger et al
(2000) are in substantial disagreement with cross-sections interpolated from
the tables of Anstee and O'Mara (1995) and Barklem and O'Mara (1997). The
discrepancy is as large as a factor of three for the 3p-4d multiplet. The two
theories are tested by using the results of each to synthesize lines in the
solar spectrum. It is found that generally the data from the theory of Anstee,
Barklem and O'Mara produce the best match to the observed solar spectrum. It is
found, using a simple model for reflection of the optical electron by the
potential barrier between the two atoms, that the reflection coefficient is too
large for avoided crossings with the upper states of subordinate lines to
contribute to line broadening, supporting the neglect of avoided ionic
crossings by Anstee, Barklem and O'Mara for these lines. The large
discrepancies between the two sets of calculations is a result of an
approximate treatment of avoided ionic crossings for these lines by Leininger
et al (2000).Comment: 18 pages, 5 ps figures included, to appear in J Phys B: At. Mol. Opt.
Phy
Evaluation and Refinement of the French Protein System (PDI) under Irish Conditions
End of Project ReportThe CP and DM degradability of grazed grass (between April and October, inclusive) and grass silage samples (differing in cut number and treatment) was determined using the in situ technique and the results obtained were used to calculate the PDIE and PDIN values. The degradability data on 12 concentrate ingredients from a previous study (Woods, 2000) were used to estimate PDIE and PDIN values for these feedstuffs. The mean PDIE and PDIN values determined for grass were 81 g/kg and 127 g/kg DM, respectively and for grass silage were 60 g/kg and 94 g/kg DM. Regression analysis resulted in equations to predict the PDIN of samples of grazed grass (PDIN = 3.8 + 0.628 CP) (RÂČ= 0.999) and grass silage (PDIN = 5.9 + 0.605 CP) (RÂČ= 0.997), and the PDIE of grazed grass (PDIE = 181.4 - 0.104 NDF - 0.195 ash - 0.047 OMD) (RÂČ= 0.987) and grass silage (PDIE = 27.7 + 0.083 DMD - 0.147 CP) (RÂČ= 0.812). The PDIE and PDIN values of 11 of the 12 concentrate ingredients were similar to those used in the French Tables but the maize distillersâ grains in this study and those used in France would appear to be quite different products.
The response to PDIE and PDIN in the diet of lactating cows was evaluated and the effect of better balancing the PDIE and PDIN supply on the efficiency of N utilisation was assessed. Twenty autumn calving cows were blocked in a complete Latin Square design and assigned to four different diets varying in PDIN and PDIE content. Each of the four treatments consisted of a concentrate, maize silage and grass silage in the proportions 37:38:25 on a DM basis. There were 4 periods of 4-week duration each. Diet A contained 92 g/kg DM of PDIE and 116 g/kg DM of PDIN. Diet B contained 103 g/kg DM of PDIE and 122 g/kg DM of PDIN. Diet C and D over supplied PDIN at 137 g/kg and 153 g/kg, respectively relative to PDIE at 111 g/kg DM. Dry matter intake increased significantly with the excess dietary PDIN relative to PDIE but there were no significant differences in milk yield and composition. Decreasing the supply of PDIE in the diet (i.e. diet A vs. B) resulted in no significant effect on milk or constituent yields but did significantly reduce the efficiency (kg milk / kg DMI) of milk production. There was also a significant reduction in the efficiency of milk produced per kg DMI with increasing dietary concentrations of PDIN and increasing PDIN: PDIE balance (B>C>D). Increasing the dietary PDIN from 122 to 153 g/kg DMI increased urine N (+54%), faecal N (+11%) and plasma urea concentrations (+75%). The results indicate that the optimum concentration of dietary PDI is approximately 103 g/kg DM for cows producing about 35 kg of milk per day. A better balance between PDIE and PDIN supply improves the efficiency of conversion of DM to milk and dietary protein
The effectiveness of community engagement in public health interventions for disadvantaged groups: a meta-analysis
BACKGROUND: Inequalities in health are acknowledged in many developed countries, whereby disadvantaged groups systematically suffer from worse health outcomes such as lower life expectancy than non-disadvantaged groups. Engaging members of disadvantaged communities in public health initiatives has been suggested as a way to reduce health inequities. This systematic review was conducted to evaluate the effectiveness of public health interventions that engage the community on a range of health outcomes across diverse health issues. METHODS: We searched the following sources for systematic reviews of public health interventions: Cochrane CDSR and CENTRAL, Campbell Library, DARE, NIHR HTA programme website, HTA database, and DoPHER. Through the identified reviews, we collated a database of primary studies that appeared to be relevant, and screened the full-text documents of those primary studies against our inclusion criteria. In parallel, we searched the NHS EED and TRoPHI databases for additional primary studies. For the purposes of these analyses, study design was limited to randomised and non-randomised controlled trials. Only interventions conducted in OECD countries and published since 1990 were included. We conducted a random effects meta-analysis of health behaviour, health consequences, self-efficacy, and social support outcomes, and a narrative summary of community outcomes. We tested a range of moderator variables, with a particular emphasis on the model of community engagement used as a potential moderator of intervention effectiveness. RESULTS: Of the 9,467 primary studies scanned, we identified 131 for inclusion in the meta-analysis. The overall effect size for health behaviour outcomes is dâ=â.33 (95% CI .26, .40). The interventions were also effective in increasing health consequences (dâ=â.16, 95% CI .06, .27); health behaviour self-efficacy (dâ=â.41, 95% CI .16, .65) and perceived social support (dâ=â.41, 95% CI .23, .65). Although the type of community engagement was not a significant moderator of effect, we identified some trends across studies. CONCLUSIONS: There is solid evidence that community engagement interventions have a positive impact on a range of health outcomes across various conditions. There is insufficient evidence to determine whether one particular model of community engagement is more effective than any other
Broadening of lines of Be II, Sr II and Ba II by collisions with hydrogen atoms and the solar abundance of strontium
In a previous paper by the present authors the theory of Anstee and O'Mara for the broadening of spectral lines of neutral atoms by collisions with hydrogen atoms was extended to singly ionized atoms. In this paper we apply the method to the resonance and triplet lines of ionized strontium, the infrared triplet of ionized barium, and the resonance lines of ionized beryllium. Analysis of five lines of ionized strontium, previously regarded as too strong for an abundance analysis, and two lines of neutral strontium results in a solar abundance of strontium of log(N/N) + 12 = 2.92 ± 0.05, which is entirely consistent with the meteoritic value
The allosteric inhibition of glycine transporter 2 by bioactive lipid analgesics is controlled by penetration into a deep lipid cavity.
The role of lipids in modulating membrane protein function is an emerging and rapidly growing area of research. The rational design of lipids that target membrane proteins for the treatment of pathological conditions is a novel extension in this field and provides a step forward in our understanding of membrane transporters. Bioactive lipids show considerable promise as analgesics for the treatment of chronic pain and bind to a high-affinity allosteric binding site on the human glycine transporter 2 (GlyT2 or SLC6A5). Here we use a combination of medicinal chemistry, electrophysiology, and computational modelling to develop a rational structure activity relationship for lipid inhibitors and demonstrate the key role of the lipid tail interactions for GlyT2 inhibition. Specifically, we examine how lipid inhibitor head group stereochemistry, tail length and double bond position promote enhanced inhibition. Overall, the L-stereoisomer is generally a better inhibitor than the D-stereoisomer, longer tail length correlates with greater potency, and the position of the double bond influences the activity of the inhibitor. We propose that the binding of the lipid inhibitor deep into the allosteric binding pocket is critical for inhibition. Furthermore, this provides insight into the mechanism of inhibition of GlyT2 and highlights how lipids can modulate the activity of membrane proteins by binding to cavities between helices. The principles identified in this work have broader implications for the development of a larger class of compounds that could target SLC6 transporters for disease treatment
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