Relationship between vision impairment and ability to perform activities of daily living

Purpose: To determine the relationship between clinical measures of vision impairment and the ability to perform activities of daily living (ADLs).

Methods: One hundred and twenty subjects with low vision from a variety of causes participated in the study. Vision impairment was assessed under binocular conditions by measuring distance visual acuity, near word acuity, Melbourne Edge Test contrast sensitivity, Pelli–Robson Chart contrast sensitivity and visual fields. The ADL performance was assessed using the Melbourne Low Vision ADL Index (MLVAI), which is in part an observed performance assessment of instrumental ADLs and in part a self-report assessment of basic self-care ADLs.

Results: All vision measures had a high, statistically significant correlation with MLVAI total score. Near word acuity, had the strongest correlation (rs=−0.86, p < 0.001), followed by Melbourne Edge Test contrast sensitivity (rs=0.80, p < 0.001). Visual field had the weakest correlation (rs=0.56, p < 0.001). Together, age, near word acuity, Melbourne Edge Test contrast sensitivity and visual field accounted for 82.2% (adjusted R2, p < 0.001) of the variance in MLVAI total score. All correlations obtained were higher for the observed performance assessment of instrumental ADLs than for the self-report assessment of basic self-care ADLs.

Conclusions: Clinical vision impairment measures are highly correlated with capacity to perform ADLs, as measured by the MLVAI.

High genetic diversity is not essential for successful introduction

Some introduced populations thrive and evolve despite the presumed loss of diversity at introduction. We aimed to quantify the amount of genetic diversity retained at introduction in species that have shown evidence of adaptation to their introduced environments. Samples were taken from native and introduced ranges of Arctotheca populifolia and Petrorhagia nanteuilii. Using microsatellite data, we identified the source for each introduction, estimated genetic diversity in native and introduced populations and calculated the amount of diversity retained in introduced populations. These values were compared to those from a literature review of diversity in native, confamilial populations and to estimates of genetic diversity retained at introduction. Gene diversity in the native range of both species was significantly lower than for confamilials. We found that, on average, introduced populations showing evidence of adaptation to their new environments retained 81% of the genetic diversity from the native range. Introduced populations of P. nanteuilii had higher genetic diversity than found in the native source populations, whereas introduced populations of A. populifolia retained only 14% of its native diversity in one introduction and 1% in another. Our literature review has shown that most introductions demonstrating adaptive ability have lost diversity upon introduction. The two species studied here had exceptionally low native range genetic diversity. Further, the two introductions of A. populifolia represent the largest percentage loss of genetic diversity in a species showing evidence of substantial morphological change in the introduced range. While high genetic diversity may increase the likelihood of invasion success, the species examined here adapted to their new environments with very little neutral genetic diversity. This finding suggests that even introductions founded by small numbers of individuals have the potential to become invasive.

High activity and Levy searches : jellyfish can search the water column like fish

Over-fishing may lead to a decrease in fish abundance and a proliferation of jellyfish. Active movements and prey search might be thought to provide a competitive advantage for fish, but here we use data-loggers to show that the frequently occurring coastal jellyfish (Rhizostoma octopus) does not simply passively drift to encounter prey. Jellyfish (327 days of data from 25 jellyfish with depth collected every 1 min) showed very dynamic vertical movements, with their integrated vertical movement averaging 619.2 m d−1, more than 60 times the water depth where they were tagged. The majority of movement patterns were best approximated by exponential models describing normal random walks. However, jellyfish also showed switching behaviour from exponential patterns to patterns best fitted by a truncated Lévy distribution with exponents (mean μ = 1.96, range 1.2–2.9) close to the theoretical optimum for searching for sparse prey (μopt ≈ 2.0). Complex movements in these ‘simple’ animals may help jellyfish to compete effectively with fish for plankton prey, which may enhance their ability to increase in dominance in perturbed ocean systems.

Two tests of approach-iron golf skill and their ability to predict tournament performance

The aim of this study was to investigate the convergent and predictive validity of two skill tests that examine the ability of golfers to hit accurate approach-iron shots. Twenty-four high-level golfers (handicap = 2.6 ± 1.7) performed the Nine-Ball Skills Test (assesses the ability to shape/control ball trajectory with high accuracy) and the Approach-Iron Skill Test (assesses the ability to hit straight shots from varying distances with high accuracy). Participants then completed at least eight rounds of tournament golf over the following 90 days and reported an indicator of approach-iron accuracy (per cent error index). A moderate correlation (r = 0.50, P < 0.05) was noted between scores for both tests. Generalised estimating equations, using two covariates (lie of the ball and distance to hole), were used to determine model fit and the amount of variance explained for tournament per cent error index. Results showed that the Approach-Iron Skill Test was the slightly stronger predictor of on-course per cent error index. With both test scores considered together, a minimal amount of additional variance was explained. These findings suggest that either of the tests used individually or combined may be used to predict tournament approach iron performance in high-level golfers.

Sleep in high-functioning children with autism : longitudinal developmental change and associations with behavior problems

Sleep disturbance is common in autism spectrum disorder (ASD), but longitudinal trajectories are poorly defined. This study measured sleep disturbance at baseline and 1 year later examining change over time and associated problem behaviors. Participants were 84 gender-matched children, aged between 7 and 12 years at baseline; 46 children were diagnosed with ASD, and 38 were typically developing (TYP) children. Parent reports on a range of scales were collected. The ASD group had more sleep disturbance than the TYP group. Sleep disturbance decreased over the year in children with ASD, but not in TYP children. Reduced sleep disturbance was associated with improved social ability. Sleep disturbance at baseline predicted later anxiety. Findings indicated different trajectories of sleep disturbance in ASD, and the implications are discussed.

Impact of nanodiffusion on the stacking fault energy in high-strength steels

A key requirement of modern steels – the combination of high strength and high deformability – can best be achieved by enabling a local adaptation of the microstructure during deformation. A local hardening is most efficiently obtained by a modification of the stacking sequence of atomic layers, resulting in the formation of twins or martensite. Combining ab initio calculations with in situ transmission electron microscopy, we show that the ability of a material to incorporate such stacking faults depends on its overall chemical composition and, importantly, the local composition near the defect, which is controlled by nanodiffusion. Specifically, the role of carbon for the stacking fault energy in high-Mn steels is investigated. Consequences for the long-term mechanical properties and the characterisation of these materials are discussed.

A self-supported, flexible, binder-free pseudo-supercapacitor electrode material with high capacitance and cycling stability from hollow, capsular polypyrrole fibers

Flexible energy devices with high performance and long-term stability are highly promising for applications in portable electronics, but remain challenging to develop. As an electrode material for pseudo-supercapacitors, conducting polymers typically show higher energy storage ability over carbon materials and larger conductivity than transition-metal oxides. However, conducting polymer-based supercapacitors often have poor cycling stability, attributable to the structural rupture caused by the large volume contrast between doping and de-doping states, which has been the main obstacle to their practical applications. Herein, we report a simple method to prepare a flexible, binder-free, self-supported polypyrrole (PPy) supercapacitor electrode with high cycling stability through using novel, hollow PPy nanofibers with porous capsular walls as a film-forming material. The unique fiber structure and capsular walls provide the PPy film with enough free-space to adapt to volume variation during doping/de-doping, leading to super-high cycling stability (capacitance retention > 90% after 11000 charge-discharge cycles at a high current density of 10 A g^-1) and high rate capability (capacitance retention ∼ 82.1% at a current density in the range of 0.25-10 A g^-1).

In vivo cardiac glucose metabolism in the high-fat fed mouse: comparison of euglycemic-hyperinsulinemic clamp derived measures of glucose uptake with a dynamic metabolomic flux profiling approach

Rationale Cardiac metabolism is thought to be altered in insulin resistance and type 2 diabetes (T2D). Our understanding of the regulation of cardiac substrate metabolism and insulin sensitivity has largely been derived from ex vivo preparations which are not subject to the same metabolic regulation as in the intact heart in vivo. Studies are therefore required to examine in vivo cardiac glucose metabolism under physiologically relevant conditions. Objective To determine the temporal pattern of the development of cardiac insulin resistance and to compare with dynamic approaches to interrogate cardiac glucose and intermediary metabolism in vivo. Methods and results Studies were conducted to determine the evolution of cardiac insulin resistance in C57Bl/6 mice fed a high-fat diet (HFD) for between 1 and 16 weeks. Dynamic in vivo cardiac glucose metabolism was determined following oral administration of [U-¹³C] glucose. Hearts were collected after 15 and 60 min and flux profiling was determined by measuring ¹³C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates. Cardiac insulin resistance, determined by euglycemic-hyperinsulinemic clamp, was evident after 3 weeks of HFD. Despite the presence of insulin resistance, in vivo cardiac glucose metabolism following oral glucose administration was not compromised in HFD mice. This contrasts our recent findings in skeletal muscle, where TCA cycle activity was reduced in mice fed a HFD. Similar to our report in muscle, glucose derived pyruvate entry into the TCA cycle in the heart was almost exclusively via pyruvate dehydrogenase, with pyruvate carboxylase mediated anaplerosis being negligible after oral glucose administration. Conclusions Under experimental conditions which closely mimic the postprandial state, the insulin resistant mouse heart retains the ability to stimulate glucose metabolism.

Failure to respond to food resource decline has catastrophic consequences for koalas in a high-density population in Southern Australia

Understanding the ability of koalas to respond to changes in their environment is critical for conservation of the species and their habitat. We monitored the behavioural response of koalas to declining food resources in manna gum (Eucalyptus viminalis) woodland at Cape Otway, Victoria, Australia, from September 2011 to November 2013. Over this period, koala population density increased from 10.1 to 18.4 koalas.ha-1. As a result of the high browsing pressure of this population, manna gum canopy condition declined with 71.4% manna gum being completely or highly defoliated in September 2013. Despite declining food resources, radio collared koalas (N = 30) exhibited high fidelity to small ranges (0.4-1.2 ha). When trees became severely defoliated in September 2013, koalas moved relatively short distances from their former ranges (mean predicted change in range centroid = 144 m) and remained in areas of 0.9 to 1.0 ha. This was despite the high connectivity of most manna gum woodland, and close proximity of the study site (< 3 km) to the contiguous mixed forest of the Great Otway National Park. Limited movement had catastrophic consequences for koalas with 71% (15/21) of radio collared koalas dying from starvation or being euthanased due to their poor condition between September and November 2013.

Wave exposure as a predictor of benthic habitat distribution on high energy temperate reefs

The new found ability to measure physical attributes of the marine environment at high resolution across broad spatial scales has driven the rapid evolution of benthic habitat mapping as a field in its own right. Improvement of the resolution and ecological validity of seafloor habitat distribution models has, for the most part, paralleled developments in new generations of acoustic survey tools such as multibeam echosounders. While sonar methods have been well demonstrated to provide useful proxies of the relatively static geophysical patterns that reflect distribution of benthic species and assemblages, the spatially and temporally variable influence of hydrodynamic energy on habitat distribution have been less well studied. Here we investigate the role of wave exposure on patterns of distribution of near-shore benthic habitats. A high resolution spectral wave model was developed for a 624 km2 site along Cape Otway, a major coastal feature of western Victoria, Australia. Comparison of habitat classifications implemented using the Random Forests algorithm established that significantly more accurate estimations of habitat distribution were obtained by including a fine-scale numerical wave model, extended to the seabed using linear wave theory, than by using depth and seafloor morphology information alone. Variable importance measures and map interpretation indicated that the spatial variation in wave-induced bottom orbital velocity was most influential in discriminating habitat classes containing the canopy forming kelp Ecklonia radiata, a foundation kelp species that affects biodiversity and ecological functioning on shallow reefs across temperate Australasia. We demonstrate that hydrodynamic models reflecting key environmental drivers on wave-exposed coastlines are important in accurately defining distributions of benthic habitats. This study highlights the suitability of exposure measures for predictive habitat modeling on wave-exposed coastlines and provides a basis for continuing work relating patterns of biological distribution to remotely-sensed patterns of the physical environment.

Marketing performance measurement : overview of approaches and practices for high technology firms

Um levantamento de 320 executivos de marketing feito pelo Conselho CMO e divulgado em junho de 2004 indicou que poucas companhias de alta tecnologia (menos de 20% das empresas entrevistadas) têm desenvolvido medidas e métricas úteis e expressivas para as suas organizações de marketing. Porém a pesquisa também revelou que companhias que estabeleceram medidas formais e compreensivas atingiram resultados financeiros superiores e tiveram mais confiança do CEO na função de marketing. Esta dissertação provê uma visão geral da informação precisa para executivos de marketing entenderem e implementarem processos para medição de performance de marketing (MPM) em suas organizações. Ela levanta questões para gerentes de marketing na industria de alta tecnologia com respeito às demandas para maior responsabilidade final, valor de medição para o melhoramento dos processos de marketing, iniciativas para determinar a lucratividade dos investimentos em marketing, e a importância das atividades de marketing nos relatórios corporativos. Esta dissertação defende a implementação de MPM, mapeando seus benefícios de medição para ambos gerentes de marketing e as suas empresas. o trabalho logo explora alguns conceitos gerais de medição de marketing e investiga algumas abordagens a MPM propostas pela industria, pela comunidade acadêmica, e pelos analistas. Finalmente, a dissertação descreve algumas práticas que todo gerente de marketing na industria de alta tecnologia deve considerar quando adotando MPM. As sugestões são gerais, mas devem familiarizar o leitor com as informações precisas para habilitar processos e rigor na sua organização com respeito a MPM.

The status of soil phosphate fractions and the ability of fungi to dissolve hardly soluble phosphates

Brazilian soils predominantly consist of iron and aluminum oxides and have a low phosphorus content. The present study was carried out in order to assess the status of phosphate fractions in pasture, forest and agricultural soils and the ability of soil fungi to solubilize iron and aluminum phosphates. The abundance of P fractions in the soils studied occurred in the following order: Fe-P > reductant-soluble Fe-P > occluded Fe-P > occluded Al-P > Al-P > Ca-P. of the 481 fungi isolated, 33 showed the ability to solubilize the inorganic phosphates in culture. of these, 14 were considered to be high or very high solubilizers based on a solubilization capacity > 1000 mu g PO43- ml(-1). Isolate F-111 was the only one that dissolved all the insoluble phosphates used. Nine isolates solubilized both Al-P and Ca-P, and four other isolates only solubilized Ca-P. The highest number of isolates with high solubilization capacity were detected in pasture soil, followed by tropical rain forest and forest patch soils. Pasture soil presented both the largest contents of insoluble phosphates and the largest number of fungal isolates with phosphate-solubilizing ability. The range and size of P fractions influenced the number of fungi and their ability to solubilize hardly soluble phosphates. (c) 2004 Elsevier B.V. All rights reserved.

High-level production of functional muscle alpha-tropomyosin in Pichia pastoris

Although numerous studies have reported the production of skeletal muscle alpha -tropomyosin in E. coli, the protein needs to be modified at the amino terminus in order to be active. Without these modifications the protein does not bind to actin, does not exhibit head-to-tail polymerization, and does not inhibit the actomyosin Mg2+-ATPase in the absence of troponin. on the other hand, the protein produced in insect cells using baculovirus as an expression vector (Urbancikova, M., and Hitchcock-DeGregori, S. E., J. Biol. Chem., 269, 24310-24315, 1994) is only partially acetylated at its amino terminal and therefore is not totally functional. In an attempt to produce an unmodified functional recombinant muscle alpha -tropomyosin for structure-function correlation studies we have expressed the chicken skeletal alpha -tropomyosin cDNA in the yeast Pichia pastoris. Recombinant protein was produced at a high level (20 mg/L) and was similar to the wild type muscle protein in its ability to polymerize, to bind to actin and to regulate the actomyosin S1 Mg2+-ATPase. (C) 2001 Academic Press.

Modeling a system of phosphated cross-linked high amylose for controlled drug release. Part 2: Physical parameters, cross-linking degrees and drug delivery relationships

High amylose cross-linked to different degrees with sodium trimetaphosphate by varying base strength (2% or 4%) and contact time (0.5-4 h) was evaluated as non-compacted systems for sodium diclophenac controlled release. The physical properties and the performance of these products for sodium diclophenac controlled release from non-compacted systems were related to the structures generated at each cross-linking degree. For samples at 2% until 2 h the swelling ability, G' and eta* values increased with the cross-linking degree, because the longer polymer chains became progressively more entangled and linked. This increases water uptake and holding, favoring the swelling and resulting in systems with higher viscosities. Additionally, the increase of cross-linking degree should contribute for a more elastic structure. The shorter chains with more inter-linkages formed at higher cross-linking degrees (2%4h and 4%) make water caption and holding difficult, decreasing the swelling, viscosity and elasticity. For 2% samples, the longer drug release time exhibited for 2%4h sample indicates that the increase of swelling and viscosity contribute for a more sustained drug release, but the mesh size of the polymeric network seems to be determinant for the attachment of drug molecules. For the 4% samples, smaller meshes size should determine less sustained release of drug. (C) 2008 Elsevier B.V. All rights reserved.

Experimental paracoccidioidomycosis in high and low antibody responder mice of Selection IV-A

High (H) and low (L) responder mice were selected for their ability to produce antibodies against sheep and human erythrocytes (Selection IV-A). In this selection, the difference in antibody responsiveness between H and L lines (HIV-A and LIV-A mice, respectively) was shown to depend mainly on macrophage function. The more rapid catabolism of antigens by macrophages in L mice has been suggested as the main cause of the low antibody production. Due to this high macrophage activity, L animals have been described as more resistant than H animals to intracellular pathogens. These animals were utilized as an experimental model of paracoccidioidomycosis. HIV-A and LIV-A mice were infected with Paracoccidioides brasiliensis by the intravenous route. As expected, H mice were more susceptible to P. brasiliensis with a shorter survival time and higher levels of specific antibodies when compared to L mice. Contrasting with the survival time, the lungs, spleen and liver from H mice showed typical nodular granulomas containing epithelioid and giant cells and few fungi. on the other hand, in LN-A mice, the lesions of these organs were characterized by looser granulomas with irregular borders and the presence of a large number of fungi, However, the adrenal gland showed different lesion patterns. In H mice these lesions were extensive and characterized by loose granulomas with numerous fungi, while in LIV-A mice the lesions were small and limited to the cortex. Moreover the HIV-A mice presented higher levels of serum corticosterone when compared to LIV-A ones. The higher susceptibility of H mice could be attributed to the extensive lesions of the adrenal glands. These results suggest the use of the H line from the IV-A Selection as an experimental model for further studies of adrenal involvement in paracoccidioidomycosis.