4,079 research outputs found
Eye muscle proprioception is represented bilaterally in the sensorimotor cortex
The cortical representation of eye position is still uncertain. In the monkey a proprioceptive representation of the extraocular muscles (EOM) of an eye were recently found within the contralateral central sulcus. In humans, we have previously shown a change in the perceived position of the right eye after a virtual lesion with rTMS over the left somatosensory area. However, it is possible that the proprioceptive representation of the EOM extends to other brain sites, which were not examined in these previous studies. The aim of this fMRI study was to sample the whole brain to identify the proprioceptive representation for the left and the right eye separately. Data were acquired while passive eye movement was used to stimulate EOM proprioceptors in the absence of a motor command. We also controlled for the tactile stimulation of the eyelid by removing from the analysis voxels activated by eyelid touch alone. For either eye, the brain area commonly activated
by passive and active eye movement was located bilaterally in the somatosensory area extending into the motor and premotor cytoarchitectonic areas. We suggest this is where EOM proprioception is processed. The bilateral representation for either eye contrasts with the contralateral representation of hand proprioception. We suggest that the proprioceptive representation of the two eyes next to each other in either somatosensory cortex and extending into the premotor cortex reflects the integrative nature of the eye position sense, which combines proprioceptive information across the two eyes with the efference copy of the oculomotor comman
The pain experiences of powered wheelchair users
Copyright © 2012 Informa UK, Ltd. This is the author's accepted manuscript. The final published article is available from the link below.Purpose: To explore the experience of pain and discomfort in users of electric-powered indoor/outdoor wheelchairs (EPIOCs) provided by a National Health Service. Methods: EPIOC users receiving their chair between February and November 2002 (N=74) were invited to participate in a telephone questionnaire/interview and 64 (aged 1081 years) agreed. Both specific and open-ended questions examined the presence of pain/discomfort, its severity, minimizing and aggravating factors, particularly in relation to the EPIOC and its use. Results: Most EPIOC users described experiences of pain with 17% reporting severe pain. Over half felt their pain was influenced by the wheelchair and few (25%) considered their chair eased their symptoms. The most common strategy for pain relief was taking medication. Other self-help strategies included changing position, exercise and complementary therapies. Respondents emphasized the provision of backrests, armrests, footrests and cushions which might alleviate or exacerbate pain, highlighting the importance of appropriate assessment for this high dependency group. Conclusions: Users related pain to their underlying medical condition, their wheelchair or a combination of the two. User feedback is essential to ensure that the EPIOC meets health needs with minimal pain. This becomes more important as the health condition of users changes over time
Freezing and water availability structure the evolutionary diversity of trees across the Americas
The historical course of evolutionary diversification shapes the current distribution of biodiversity, but the main forces constraining diversification are still a subject of debate. We unveil the evolutionary structure of tree species assemblages across the Americas to assess whether an inability to move or an inability to evolve is the predominant constraint in plant diversification and biogeography. We find a fundamental divide in tree lineage composition between tropical and extratropical environments, defined by the absence versus presence of freezing temperatures. Within the Neotropics, we uncover a further evolutionary split between moist and dry forests. Our results demonstrate that American tree lineages tend to retain their ancestral environmental relationships and that phylogenetic niche conservatism is the primary force structuring the distribution of tree biodiversity. Our study establishes the pervasive importance of niche conservatism to community assembly even at intercontinental scales
Elastic properties of graphyne-based nanotubes
Graphyne nanotubes (GNTs) are nanostructures obtained from rolled up graphyne
sheets, in the same way carbon nanotubes (CNTs) are obtained from graphene
ones. Graphynes are 2D carbon-allotropes composed of atoms in sp and sp2
hybridized states. Similarly to conventional CNTs, GNTs can present different
chiralities and electronic properties. Because of the acetylenic groups (triple
bonds), GNTs exhibit large sidewall pores that influence their mechanical
properties. In this work, we studied the mechanical response of GNTs under
tensile stress using fully atomistic molecular dynamics simulations and density
functional theory (DFT) calculations. Our results show that GNTs mechanical
failure (fracture) occurs at larger strain values in comparison to
corresponding CNTs, but paradoxically with smaller ultimate strength and
Young's modulus values. This is a consequence of the combined effects of the
existence of triple bonds and increased porosity/flexibility due to the
presence of acetylenic groups
Reversion of Steatosis by SREBP-1c Antisense Oligonucleotide did not Improve Hepatic Insulin Action in Diet-induced Obesity Mice
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The literature has associated hepatic insulin action with NAFLD. In this sense, treatments to revert steatosis and improve hepatic insulin action become important. Our group has demonstrated that inhibition of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) reverses hepatic steatosis. However, insulin signals after NAFLD reversion require better investigation. Thus, in this study, we investigated if the reversal of NAFLD by SREBP-1c inhibitor results in improvement in the hepatic insulin signal in obesity mice. After installation/achievement of diet-induced obesity and insulin resistance, Swiss mice were divided into 3 groups: i) Lean, ii) D-IHS, diet-induced hepatic steatosis [no treatment with antisense oligonucleotide (ASO)], and iii) RD-IHS, reversion of diet-induced hepatic steatosis (treated with ASO). The mice were treated with ASO SREBP-1c as previously described by our group. After ASO treatment, one set of animals was anesthetized and used for in vivo test, and another mice set was anesthetized and used for histology and Western blot analysis. Reversion of diet-induced hepatic steatosis did not change blood glucose, glucose decay constant (k(ITT)), body weight, or serum insulin levels. In addition, results showed that the protocol did not improve insulin pathway signaling, as confirmed by the absence of changes in IR, IRS1, Akt and Foxo1 phosphorylation in hepatic tissue. In parallel, no alterations were observed in proinflammatory molecules. Thus, our results suggest that the inhibition of SREBP-1c reverts steatosis, but without improving insulin hepatic resistance.4412885890Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Santa Catarina (FAPESC)Universidade do Extremo Sul Catarinense (UNESC)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Dynamic CpG methylation delineates subregions within super-enhancers selectively decommissioned at the exit from naïve pluripotency
Clusters of enhancers, referred as to super-enhancers (SEs), control the expression of cell identity genes. The organisation of these clusters, and how they are remodelled upon developmental transitions remain poorly understood. Here, we report the existence of two types of enhancer units within SEs typified by distinctive CpG methylation dynamics in embryonic stem cells (ESCs). We find that these units are either prone for decommissioning or remain constitutively active in epiblast stem cells (EpiSCs), as further established in the peri-implantation epiblast in vivo. Mechanistically, we show a pivotal role for ESRRB in regulating the activity of ESC-specific enhancer units and propose that the developmentally regulated silencing of ESRRB triggers the selective inactivation of these units within SEs. Our study provides insights into the molecular events that follow the loss of ESRRB binding, and offers a mechanism by which the naive pluripotency transcriptional programme can be partially reset upon embryo implantation
Pharmacokinetics of phenoxodiol, a novel isoflavone, following intravenous administration to patients with advanced cancer
Background: Phenoxodiol is a novel isoflavone currently being studied in clinical trials for the treatment of cancer. This study reports the pharmacokinetics of phenoxodiol in patients with cancer.Methods: The pharmacokinetics of phenoxodiol was studied following a single intravenous (iv) bolus dose and during a continuous intravenous infusion. Three men with prostate cancer and 3 women with breast cancer received IV bolus phenoxodiol (5 mg/kg) and plasma was sampled for free and total phenoxodiol levels. On a separate occasion 5 of the same patients received a continuous intravenous infusion of phenoxodiol (2 mg/kg/h) and plasma was again sampled for free and total phenoxodiol levels. Phenoxodiol was measured using gradient HPLC with ultraviolet detection.Results: Following bolus injection, free and total phenoxodiol appeared to follow first order pharmacokinetics. The elimination half-lives for free and total phenoxodiol were 0.67 ± 0.53 h and 3.19 ± 1.93 h, respectively, while the total plasma clearance rates were 2.48 ± 2.33 L/h and 0.15 ± 0.08 L/h, respectively. The respective apparent volumes of distribution were 1.55 ± 0.69 L/kg and 0.64 ± 0.51 L/kg. During continuous intravenous infusion, free phenoxodiol accumulated rapidly to reach a mean concentration at steady state of 0.79 ± 0.14 μg/ml after 0.87 ± 0.18 h. The apparent accumulation half-life of free phenoxodiol was 0.17 ± 0.04 h while the plasma clearance during continuous infusion was 1.29 ± 0.23 L/h.Conclusions: Phenoxodiol has a short plasma half-life, particularly in the free form, leading to a rapid attainment of steady state levels during continuous intravenous infusion.Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12610000334000
Scoping review on vector-borne diseases in urban areas : transmission dynamics, vectorial capacity and co-infection
BACKGROUND: Transmission dynamics, vectorial capacity, and co-infections have substantial impacts on vector-borne diseases (VBDs) affecting urban and suburban populations. Reviewing key factors can provide insight into priority research areas and offer suggestions for potential interventions. MAIN BODY: Through a scoping review, we identify knowledge gaps on transmission dynamics, vectorial capacity, and co-infections regarding VBDs in urban areas. Peer-reviewed and grey literature published between 2000 and 2016 was searched. We screened abstracts and full texts to select studies. Using an extraction grid, we retrieved general data, results, lessons learned and recommendations, future research avenues, and practice implications. We classified studies by VBD and country/continent and identified relevant knowledge gaps. Of 773 articles selected for full-text screening, 50 were included in the review: 23 based on research in the Americas, 15 in Asia, 10 in Africa, and one each in Europe and Australia. The largest body of evidence concerning VBD epidemiology in urban areas concerned dengue and malaria. Other arboviruses covered included chikungunya and West Nile virus, other parasitic diseases such as leishmaniasis and trypanosomiasis, and bacterial rickettsiosis and plague. Most articles retrieved in our review combined transmission dynamics and vectorial capacity; only two combined transmission dynamics and co-infection. The review identified significant knowledge gaps on the role of asymptomatic individuals, the effects of co-infection and other host factors, and the impacts of climatic, environmental, and socioeconomic factors on VBD transmission in urban areas. Limitations included the trade-off from narrowing the search strategy (missing out on classical modelling studies), a lack of studies on co-infections, most studies being only descriptive, and few offering concrete public health recommendations. More research is needed on transmission risk in homes and workplaces, given increasingly dynamic and mobile populations. The lack of studies on co-infection hampers monitoring of infections transmitted by the same vector. CONCLUSIONS: Strengthening VBD surveillance and control, particularly in asymptomatic cases and mobile populations, as well as using early warning tools to predict increasing transmission, were key strategies identified for public health policy and practice
Sociodemographic characteristics determine dietary pattern adherence during pregnancy
OBJECTIVE:Sociodemographic factors may affect adherence to specific dietary patterns during pregnancy. The present study aimed to identify dietary patterns during pregnancy and associated factors among Brazilian pregnant women.
DESIGN:A cross-sectional analysis. Dietary intake was evaluated with a semi-quantitative FFQ during the first postpartum week; the time frame included the second and third gestational trimesters. Principal component analysis was used to identify dietary patterns during pregnancy. Sociodemographic data were obtained using a structured questionnaire. Multiple linear regressions were applied to test the associations between the sociodemographic factors and dietary patterns.
SETTING:Mesquita, Rio de Janeiro, Brazil, 2011.
SUBJECTS:Postpartum women (n 327) who were 18-45 years of age and Mesquita residents.
RESULTS:Three different dietary patterns were identified: 'healthy' (mainly comprising legumes, vegetables and fruits), 'mixed' (mainly comprising candy, butter and margarine, and snacks) and 'traditional' (mainly comprising beans and rice). Women with a higher monthly per capita family income (β=0·0006; 95% CI 0·0001, 0·001; P=0·011) and women of older age (β=0·021; 95% CI -0·001, 0·042; P=0·058) were more likely to adhere to the 'healthy' dietary pattern. Women with higher parity were less likely to adhere to the 'healthy' pattern (β=-0·097; 95% CI -0·184, -0·009; P=0·030) and were more likely to adhere to the 'traditional' pattern (β=0·098; 95% CI 0·021, 0·175; P=0·012). Although not statistically significant, older women were less likely to adhere to the 'mixed' (β=-0·017; 95% CI -0·037, 0·003; P=0·075) and 'traditional' (β=-0·018; 95% CI -0·037, 0·001; P=0·061) dietary patterns.
CONCLUSIONS:Monthly per capita family income, parity and maternal age were factors associated with adherence to a healthy diet during pregnancy
On domain walls in a Ginzburg-Landau non-linear S^2-sigma model
The domain wall solutions of a Ginzburg-Landau non-linear -sigma hybrid
model are unveiled. There are three types of basic topological walls and two
types of degenerate families of composite - one topological, the other
non-topological- walls. The domain wall solutions are identified as the finite
action trajectories (in infinite time) of a related mechanical system that is
Hamilton-Jacobi separable in sphero-conical coordinates. The physical and
mathematical features of these domain walls are thoroughly discussed.Comment: 26 pages, 18 figure
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