2,382 research outputs found
Reorganisation of brain networks in frontotemporal dementia and progressive supranuclear palsy.
The disruption of large-scale brain networks is increasingly recognised as a consequence of neurodegenerative dementias. We assessed adults with behavioural variant frontotemporal dementia and progressive supranuclear palsy using magnetoencephalography during an auditory oddball paradigm. Network connectivity among bilateral temporal, frontal and parietal sources was examined using dynamic causal modelling. We found evidence for a systematic change in effective connectivity in both diseases. Compared with healthy subjects, who had focal modulation of intrahemispheric frontal-temporal connections, the patient groups showed abnormally extensive and inefficient networks. The changes in connectivity were accompanied by impaired responses of the auditory cortex to unexpected deviant tones (MMNm), despite normal responses to standard stimuli. Together, these results suggest that neurodegeneration in two distinct clinical syndromes with overlapping profiles of prefrontal atrophy, causes a similar pattern of reorganisation of large-scale networks. We discuss this network reorganisation in the context of other focal brain disorders and the specific vulnerability of functional brain networks to neurodegenerative disease
Effect Of CARICAPRYL-99 Seed Alkaloid Extract On The Serum Levels Of Sex Hormones And Pituitary Gonadotrophins In Male Albino Rats
Summary: Activity of alkaloid extract of caricapryl–99 seeds (Carica papaya Linn seeds) on the serum levels of steroid hormones was studied in adult male albino rats. Three tolerated doses obtained from the graph of percectage toxicity (10, 50 and 150 mg/kg) were separately administered orally, daily for three days to three groups of male rats (n=5) while group four of 5 rats received the vehicle (corn oil) as control. The results showed that 10mg/kg/d caused increase serum levels of FSH and estrogen but decrease in the serum levels of LH and testosterone compared to control; 50mg/kg/d elevated the serum levels of FSH, estrogen but inhibited testosterone; while 150mg/kg/d pretreatments caused a significant decrease (
An assessment of healthcare professionals' knowledge about and attitude towards influenza vaccination in Freetown Sierra Leone: A cross-sectional study
© 2017 The Author(s). Background: Vaccinating healthcare professionals against influenza is considered an effective infection control measure. However, there is a low uptake of influenza vaccine among healthcare professionals around the globe. Currently, it is unknown whether healthcare professionals in Sierra Leone are aware of, and have been vaccinated against influenza. Also, there is a paucity of research evidence on their level of knowledge and attitude toward influenza vaccination. This study assessed healthcare professionals' current influenza vaccine uptake rate, reasons for not getting vaccinated as well as their awareness, knowledge of, and attitude towards influenza vaccination in Freetown Sierra Leone. Method: A cross-sectional study was conducted between February and April 2016 among healthcare providers working in four public and two private health facilities in Freetown Sierra Leone. Linear regression analysis, one-way ANOVA and independent t-test were employed for data analysis. Results: Among 706 respondents that participated in the study more than half were females 378 (53.6%), nurses 425 (60.4%), and the majority were between the age group of 20-39 years 600 (85.3%). Only 46 (6.5%) were vaccinated against influenza. Key reasons for not vaccinated against influenza were less awareness about influenza vaccination among HCPs 580 (82.73%) with (β = 0.154; CI 0.058-0.163), the high cost of influenza vaccines and therefore not normally purchased 392 (55.92%) having (β = 0.150; CI 0.063-0.186). More than half believed that HCPs are less susceptible to influenza infections than other people. Also, majority 585 (84.3%) of HCPs thought that influenza disease could be transmitted after symptoms appear. In addition, 579 (83.2%) of HCPs felt that symptoms usually appear 8-10 days after exposure. Close to half 321 (46.0%) of HCPs were not aware of the influenza immunisation guidelines published by the Advisory Committee on Immunization Practices and Centre for Disease Control. Conclusion: Influenza vaccine coverage among healthcare professionals in Freetown Sierra Leone was low. High cost, inadequate knowledge about influenza and its vaccine as well as the lack of awareness of vaccine availability were key barriers. Increasing access to influenza vaccine and the use of appropriate educational interventions to increase knowledge and awareness are required to improve influenza vaccination coverage among HCPs
The large N limit of M2-branes on Lens spaces
We study the matrix model for N M2-branes wrapping a Lens space L(p,1) =
S^3/Z_p. This arises from localization of the partition function of the ABJM
theory, and has some novel features compared with the case of a three-sphere,
including a sum over flat connections and a potential that depends
non-trivially on p. We study the matrix model both numerically and analytically
in the large N limit, finding that a certain family of p flat connections give
an equal dominant contribution. At large N we find the same eigenvalue
distribution for all p, and show that the free energy is simply 1/p times the
free energy on a three-sphere, in agreement with gravity dual expectations.Comment: 28 pages, 4 figure
Good neighbours: distribution of black-tufted marmoset (Callithrix penicillata) in an urban environment
Context Primates are one of the most charismatic and widely studied vertebrate groups. However, the study of new world primates in green patches within urban areas has been neglected. Such primates have been viewed as a source of human–animal conflict; however, their ecological importance to urban ecosystems and their role in human well being is poorly understood. Aims To increase understanding of both ecological and socioeconomical factors affecting the distribution, density and group sizes of urban marmosets in a large Brazilian city (Belo Horizonte). Methods A map of vegetation cover and land use was produced and employed to investigate the distribution of marmosets. An online questionnaire was extensively publicised, which permitted the public to report the occurrence or not of marmosets near their residences. For sites with low salary levels and low internet availability, face-to-face interviews were conducted. Additionally, field surveys were conducted in 120 green areas identified by spatial analysis as potential areas of occurrence. The human population density, salary levels and green areas were posteriorly correlated with marmoset distribution. Key results Despite the urbanisation and high human population density, green fragments within the city still housed marmoset groups. However, the presence of green areas did not always indicate primate presence. Group presence was significantly related to the size of parks or green areas and negatively related to built-up areas, and human density. Salary levels were related to more forested streets and possibly tolerance. Marmosets were classified as urban utilisers. Conclusions The human–wildlife conflict with marmoset species was relatively low, owing to marmoset avoidance of built-up areas. The interaction of marmoset species and city dwellers was mainly limited to borders of forest fragments and inside city parks, and appeared to be human motivated. Implications This study showed the importance of public involvement in wildlife studies in urban environments; clarifying the interaction between city dwellers and wild species is essential to mitigate negative interactions
The binaural masking level difference: cortical correlates persist despite severe brain stem atrophy in progressive supranuclear palsy.
Under binaural listening conditions, the detection of target signals within background masking noise is substantially improved when the interaural phase of the target differs from that of the masker. Neural correlates of this binaural masking level difference (BMLD) have been observed in the inferior colliculus and temporal cortex, but it is not known whether degeneration of the inferior colliculus would result in a reduction of the BMLD in humans. We used magnetoencephalography to examine the BMLD in 13 healthy adults and 13 patients with progressive supranuclear palsy (PSP). PSP is associated with severe atrophy of the upper brain stem, including the inferior colliculus, confirmed by voxel-based morphometry of structural MRI. Stimuli comprised in-phase sinusoidal tones presented to both ears at three levels (high, medium, and low) masked by in-phase noise, which rendered the low-level tone inaudible. Critically, the BMLD was measured using a low-level tone presented in opposite phase across ears, making it audible against the noise. The cortical waveforms from bilateral auditory sources revealed significantly larger N1m peaks for the out-of-phase low-level tone compared with the in-phase low-level tone, for both groups, indicating preservation of early cortical correlates of the BMLD in PSP. In PSP a significant delay was observed in the onset of the N1m deflection and the amplitude of the P2m was reduced, but these differences were not restricted to the BMLD condition. The results demonstrate that although PSP causes subtle auditory deficits, binaural processing can survive the presence of significant damage to the upper brain stem.This work has been supported by the Wellcome Trust (Grants 088324 and 088263); Medical Research Council (G0700503 to B. C. P. Ghosh); Guarantors of Brain (to B. C. P. Ghosh); Raymond and Beverley Sackler Trust (to B. C. P. Ghosh); and National Institute of Health Research Cambridge Comprehensive Biomedical Research Centre including the CambridgeBrain Bank.This is the final version of the article. It first appeared from American Physiological Society via http://dx.doi.org/10.1152/jn.00062.201
The use of automated quantitative analysis to evaluate epithelial-to-mesenchymal transition associated proteins in clear cell renal cell carcinoma.
BACKGROUND: Epithelial-to-mesenchymal transition (EMT) has recently been implicated in the initiation and progression of renal cell carcinoma (RCC). Some mRNA gene expression studies have suggested a link between the EMT phenotype and poorer clinical outcome from RCC. This study evaluated expression of EMT-associated proteins in RCC using in situ automated quantitative analysis immunofluorescence (AQUA) and compared expression levels with clinical outcome. METHODS/PRINCIPAL FINDINGS: Unsupervised hierarchical cluster analysis of pre-existing RCC gene expression array data (GSE16449) from 36 patients revealed the presence of an EMT transcriptional signature in RCC [E-cadherin high/SLUG low/SNAIL low]. As automated immunofluorescence technology is dependent on accurate definition of the tumour cells in which measurements take place is critical, extensive optimisation was carried out resulting in a novel pan-cadherin based tumour mask that distinguishes renal cancer cells from stromal components. 61 patients with ccRCC and clinical follow-up were subsequently assessed for expression of EMT-associated proteins (WT1, SNAIL, SLUG, E-cadherin and phospho-β-catenin) on tissue microarrays. Using Kaplan-Meier analysis both SLUG (p = 0.029) and SNAIL (p = 0.024) (log rank Mantel-Cox) were significantly associated with prolonged progression free survival (PFS). Using Cox regression univariate and multivariate analysis none of the biomarkers were significantly correlated with outcome. 14 of the 61 patients expressed the gene expression analysis predicted EMT-protein signature [E-cadherin high/SLUG low/SNAIL low], which was not found to be associated to PFS when measured at the protein level. A combination of high expression of SNAIL and low stage was able to stratify patients with greater significance (p = 0.001) then either variable alone (high SNAIL p = 0.024, low stage p = 0.029). CONCLUSIONS: AQUA has been shown to have the potential to identify EMT related protein targets in RCC allowing for stratification of patients into high and low risk groups, as well the ability to assess the association of reputed EMT signatures to progression of the disease
A Single Basis for Developmental Buffering of Drosophila Wing Shape
The nature of developmental buffering processes has been debated extensively, based on both theoretical reasoning and empirical studies. In particular, controversy has focused on the question of whether distinct processes are responsible for canalization, the buffering against environmental or genetic variation, and for developmental stability, the buffering against random variation intrinsic in developmental processes. Here, we address this question for the size and shape of Drosophila melanogaster wings in an experimental design with extensively replicated and fully controlled genotypes. The amounts of variation among individuals and of fluctuating asymmetry differ markedly among genotypes, demonstrating a clear genetic basis for size and shape variability. For wing shape, there is a high correlation between the amounts of variation among individuals and fluctuating asymmetry, which indicates a correspondence between the two types of buffering. Likewise, the multivariate patterns of shape variation among individuals and of fluctuating asymmetry show a close association. For wing size, however, the amounts of individual variation and fluctuating asymmetry are not correlated. There was a significant link between the amounts of variation between wing size and shape, more so for fluctuating asymmetry than for variation among individuals. Overall, these experiments indicate a considerable degree of shared control of individual variation and fluctuating asymmetry, although it appears to differ between traits
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