18 resultados para Complex sample analysis

em University of Queensland eSpace - Australia


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Objective: To investigate laryngeal function and phonatory disturbance in children with traumatic brain injury (TBI), using both perceptual and instrumental techniques. Design and participants: The performance of 16 individuals with moderate to severe TBI acquired in childhood and 16 nonneurologicatly impaired control subjects was compared on a battery of perceptual (Frenchay Dysarthria Assessment, speech sample analysis) and instrumental (Aerophone II, laryngograph) assessments. Results and conclusions: As a group, the children with TBI demonstrated normal, or only minimally impaired laryngeal function, when compared with the control group, which contrasts with the significant laryngeal impairment noted in adults after TBI. Several reasons for the different findings in relation to laryngeal function in adults and children after TBI are postulated: (1) differing types of injury usually incurred by adults and children may result in a relatively decreased degree of neurologic impairment in these children, (2) differences in recovery potential between adults and children, and (3) the pediatric larynx is still developing, hence it may be better able to compensate for any impairment incurred.

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Primary objective: To investigate the articulatory function of a group of children with traumatic brain injury (TBI), using both perceptual and instrumental techniques. Research design: The performance of 24 children with TBI was assessed on a battery of perceptual (Frenchay Dysarthria Assessment, Assessment of Intelligibility of Dysarthric Speech and speech sample analysis) and instrumental ( lip and tongue pressure transduction systems) assessments and compared with that of 24 non-neurologically impaired children matched for age and sex. Main outcomes: Perceptual assessment identified consonant and vowel imprecision, increased length of phonemes and overall reduction in speech intelligibility, while instrumental assessment revealed significant impairment in lip and tongue function in the TBI group, with rate and pressure in repetitive lip and tongue tasks particularly impaired. Significant negative correlations were identified between the degree of deviance of perceptual articulatory features and decreased function on many non-speech measures of lip function, as well as maximum tongue pressure and fine force tongue control at 20% of maximum tongue pressure. Additionally, sub-clinical articulatory deficits were identified in the children with TBI who were non-dysarthric. Conclusion: The results of the instrumental assessment of lip and tongue function support the finding of substantial articulatory dysfunction in this group of children following TBI. Hence, remediation of articulatory function should be a therapeutic priority in these children.

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The present investigation aimed to critically examine the factor structure and psychometric properties of the Anxiety Sensitivity Index - Revised (ASI-R). Confirmatory factor analysis using a clinical sample of adults (N = 248) revealed that the ASI-R could be improved substantially through the removal of 15 problematic items in order to account for the most robust dimensions of anxiety sensitivity. This modified scale was renamed the 21-item Anxiety Sensitivity Index (21-item ASI) and reanalyzed with a large sample of normative adults (N = 435), revealing configural and metric invariance across groups. Further comparisons with other alternative models, using multi-sample analysis, indicated the 21-item ASI to be the best fitting model for both groups. There was also evidence of internal consistency, test-retest reliability, and construct validity for both samples suggesting that the 21-item ASI is a useful assessment device for investigating the construct of anxiety sensitivity in both clinical and normative populations.

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Objective: To evaluate the effectiveness of continuous positive airway pressure (CPAP) therapy in the treatment of hypernasality following traumatic brain injury (17111). Design: An A-B-A experimental research design. Assessments were conducted prior to commencement of the program, midway, immediately posttreatment, and 1 month after completion of the CPAP therapy program. Participants: Three adults with dysarthria and moderate to severe hypernasality subsequent to TBI. Outcome Measures: Perceptual evaluation using the Frenchay Dysarthria Assessment, the Assessment of Intelligibility of Dysarthric Speech, and a speech sample analysis, and instrumental evaluation using the Nasometer. Results: Between assessment periods, varying degrees of improvement in hypernasality and sentence intelligibility were noted. At the 1-month post-CPAP assessment, all 3 participants demonstrated reduced nasalance values, and 2 exhibited increased sentence intelligibility. Conclusions: CPAP may be a valuable treatment of impaired velopharyngeal function in the TBI population.

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A cross-sectional study was undertaken in Kosrae, Federated States of Micronesia to assess preschool children and caretaker dietary intake of vitamin A (VA) (including provitamin A carotenoids) and other nutrients contributing to VA status and to investigate relationships between VA intake and factors affecting dietary intake. Ethnography, food sample analysis, two dietary assessment methods (7-day food frequency questionnaire and quantitative 24-hour recall for three nonconsecutive days) administered by trained interviewers to a random sample group, and cultivar difference specification (yellow-fleshed versus white-fleshed bananas) contributed to the richness of the study. Vitamin A intake was low, approximately half of the estimated requirements for children (n = 65) and caretakers (n = 65), whereas protein intake was high. There were no clear significant relationships associated with gender, caretaker education, caretaker occupation, and socio-economic status with VA intake, indicating that a broad-based intervention over all population segments is needed to change dietary behavior, The ethnographic approach was critical for survey instrument development and data analysis.

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We present results of our wide-field redshift survey of galaxies in a 285 square degree region of the Shapley Supercluster (SSC), based on a set of 10 529 velocity measurements (including 1201 new ones) on 8632 galaxies obtained from various telescopes and from the literature. Our data reveal that the main plane of the SSC (v approximate to 14 500 km s(-1)) extends further than previous estimates, filling the whole extent of our survey region of 12 degrees by 30 degrees on the sky (30 x 75 h(-1) Mpc). There is also a connecting structure associated with the slightly nearer Abell 3571 cluster complex (v approximate to 12 000 km s(-1)). These galaxies seem to link two previously identified sheets of galaxies and establish a connection with a third one at v = 15 000 km s(-1) near RA = 13(h). They also tend to fill the gap of galaxies between the foreground Hydra-Centaurus region and the more distant SSC. In the velocity range of the Shapley Supercluster (9000 km s(-1) < cz < 18 000 km s(-1)), we found redshift-space overdensities with b(j) < 17.5 of similar or equal to 5.4 over the 225 square degree central region and similar or equal to 3.8 in a 192 square degree region excluding rich clusters. Over the large region of our survey, we find that the intercluster galaxies make up 48 per cent of the observed galaxies in the SSC region and, accounting for the different completeness, may contribute nearly twice as much mass as the cluster galaxies. In this paper, we discuss the completeness of the velocity catalogue, the morphology of the supercluster, the global overdensity, and some properties of the individual galaxy clusters in the Supercluster.

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Patterns of geographic parthenogenesis can provide insight into the ecological implications of the transition from sexual to parthenogenetic reproduction. We analysed quantitatively the environmental niches occupied by sexual and parthenogenetic geckos of the Heteronotia binoei complex in the Australian and zone. This complex consists of two independently derived maternal lineages of hybrid parthenogens, which, in turn, include two different triploid races that resulted from reciprocal backcrossing with the parental sexual taxa. The sexual progenitors are still extant and occupy very distinct environmental niches. The triploid parthenogenetic races are biased in their environmental niche towards those of the sexual races for which their genomes are biased and this dosage effect is apparent in both maternal lineages. Thus triploidy may have benefited the parthenogens through partial recovery of the parental niches. Although the parthenogens have a broader geographic distribution than their sexual progenitors, their environmental niche is narrower and biased towards one of the sexual races. In keeping with general patterns of geographic parthenogenesis. parthenogenetic H. binoei occupy a harsher environment than the sexual forms. occurring in regions of persistently low rainfall. Bioclimatic modelling suggests patterns of rainfall are important in limiting the distribution of sexual and parthenogenetic taxa. and extrapolation from the current bioclimatic profiles indicates potential for further eastward range expansion by the parthenogens.

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Inferring the spatial expansion dynamics of invading species from molecular data is notoriously difficult due to the complexity of the processes involved. For these demographic scenarios, genetic data obtained from highly variable markers may be profitably combined with specific sampling schemes and information from other sources using a Bayesian approach. The geographic range of the introduced toad Bufo marinus is still expanding in eastern and northern Australia, in each case from isolates established around 1960. A large amount of demographic and historical information is available on both expansion areas. In each area, samples were collected along a transect representing populations of different ages and genotyped at 10 microsatellite loci. Five demographic models of expansion, differing in the dispersal pattern for migrants and founders and in the number of founders, were considered. Because the demographic history is complex, we used an approximate Bayesian method, based on a rejection-regression algorithm. to formally test the relative likelihoods of the five models of expansion and to infer demographic parameters. A stepwise migration-foundation model with founder events was statistically better supported than other four models in both expansion areas. Posterior distributions supported different dynamics of expansion in the studied areas. Populations in the eastern expansion area have a lower stable effective population size and have been founded by a smaller number of individuals than those in the northern expansion area. Once demographically stabilized, populations exchange a substantial number of effective migrants per generation in both expansion areas, and such exchanges are larger in northern than in eastern Australia. The effective number of migrants appears to be considerably lower than that of founders in both expansion areas. We found our inferences to be relatively robust to various assumptions on marker. demographic, and historical features. The method presented here is the only robust, model-based method available so far, which allows inferring complex population dynamics over a short time scale. It also provides the basis for investigating the interplay between population dynamics, drift, and selection in invasive species.

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Maximizing the contribution of endemic natural enemies to integrated pest management (IPM) programs requires a detailed knowledge of their interactions with the target pest. This experimental field study evaluated the impact of the endemic natural enemy complex of Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) on pest populations in commercial cabbage crops in southeastern Queensland, Australia. Management data were used to score pest management practices at experimental sites on independent Brassica farms practicing a range of pest management strategies, and mechanical methods of natural enemy exclusion were used to assess the impact of natural enemies on introduced cohorts of P. xylostella at each site. Natural enemy impact was greatest at sites adopting IPM and least at sites practicing conventional pest management strategies. At IPM sites, the contribution of natural enemies to P. xylostella mortality permitted the cultivation of marketable crops with no yield loss but with a substantial reduction in insecticide inputs. Three species of larval parasitoids (Diadegma semiclausum Hellen [Hymenoptera: Ichneumonidae], Apanteles ippeus Nixon [Hymenoptera: Braconidae], and Oomyzus sokolowskii Kurdjumov [Hymenoptera: Eulophidae]) and one species of pupal parasitoid Diadromus collaris Gravenhorst (Hymenoptera: Ichneumonidae) attacked immature P. xylostella. The most abundant groups of predatory arthropods caught in pitfall traps were Araneae (Lycosidae) > Coleoptera (Carabidae, Coccinelidae, Staphylinidae) > Neuroptera (Chrysopidae) > Formicidae, whereas on crop foliage Araneae (Clubionidae, Oxyopidae) > Coleoptera (Coccinelidae) > Neuroptera (Chrysopidae) were most common. The abundance and diversity of natural enemies was greatest at sites that adopted IPM, correlating greater P. xylostella mortality at these sites. The efficacy of the natural enemy complex to pest mortality under different pest management regimes and appropriate strategies to optimize this important natural resource are discussed.

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The psaBCA locus of Streptococcus pneumoniae encodes a putative ABC Mn2+-permease complex. Downstream of the operon is psaD, which may be co-transcribed and encodes a thiol peroxidase. Previously, there has been discordance concerning the phenotypic impact of mutations in the psa locus, resolution of which has been complicated by differences in mutant construction and the possibility of polar effects. Here, we constructed unmarked, in frame deletion mutants DeltapsaB, DeltapsaC, DeltapsaA, DeltapsaD, DeltapsaBC, DeltapsaBCA and DeltapsaBCAD in S. pneumoniae D39 to examine the role of each gene within the locus in Mn2+ uptake, susceptibility to oxidative stress, virulence, nasopharyngeal colonization and chain morphology. The requirement for Mn2+ for growth and transformation was also investigated for all mutants. Inductively coupled plasma mass spectrometry (ICP-MS) analysis provided the first direct evidence that PsaBCA is indeed a Mn2+ transporter. However, this study did not substantiate previous reports that the locus plays a role in choline-binding protein pro-duction or chain morphology. We also confirmed the importance of the Psa permease in systemic virulence and resistance to superoxide and hydrogen peroxide, as well as demonstrating a role in nasopharyngeal colonization for the first time. Further evi-dence is provided to support the requirement for Mn2+ supplementation for growth and transformation of DeltapsaB, DeltapsaC, DeltapsaA, DeltapsaBC, DeltapsaBCA and DeltapsaBCAD mutants. However, transformation, as well as growth, of the DeltapsaD mutant was not dependent upon Mn2+ supplementation. We also show that, apart from sensitivity to hydrogen peroxide, the DeltapsaD mutant exhibited essentially similar phenotypes to those of the wild type. Western blot analysis with a PsaD antiserum showed that deleting any of the genes upstream of psaD did not affect its expression. However, we found that deleting psaB resulted in decreased expression of PsaA relative to that in D39, whereas deleting both psaB and psaC resulted in at least wild-type levels of PsaA.

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This paper presents a descriptive analysis of the prevalence of depressive symptoms among a national cohort of young Australian women, and the characteristics of those who experience them. It explores the associations between demographic and health-related variables and depressive symptoms in a representative sample of 9333 Australian women aged 22-27 years, from the Australian Longitudinal Study on Women's Health. Approximately 30% of these young women indicated that they were experiencing depressive symptoms, as indicated by the Center for Epidemiological Studies Depression Scale (CESD-10). After adjusting for age and rurality of residence, depressive symptoms were related to the following demographic variables: low income, low educational qualifications, a history of unemployment, not being in a relationship, and living arrangements other than living with a partner. Those health-related variables that were significantly associated with depressive symptoms included frequent visits to doctors and medical specialists, and a higher number of physical symptoms experienced and diagnoses made. More illicit drug use, higher use of cigarettes and alcohol, and lower exercise status were also significantly associated with depressive symptoms. This analysis supports the view that depression is one aspect of a multifactorial cluster of negative conditions across several domains of functioning, including physical ill-health, risky behaviours, and marginal social status. The complex interactions between these conditions, of which depression is only one, underscore the difficulties that arise in the treatment of depression and support the value of preventive interventions as an important public health strategy.

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Objective: This study aimed to investigate associations between violence and younger women's reproductive events using Survey 1 (1996) data of the Younger cohort of the Australian Longitudinal Study of Women's Health (ALSWH). Methods: Multinomial regression, using composite variables for both violence and reproductive events, adjusting for socioeconomic variables and weighted for rural and remote areas. Results: 23.8% of 14,784 women aged 18 to 23 years reported violence; 12.6% reported non-partner violence in the previous year; and 11.2% reported ever having had a violent relationship with a partner. Of the latter group, 43% (4.8% overall) also reported violence in the past year. Compared with women reporting no violence, women reporting partner but not recent violence (OR 2.55, 95% Cl 2.10-3.09) or partner and recent violence (OR 3.96, 95% Cl 3.18-4.93) were significantly more likely to have had one or more pregnancies. Conversely, having had a pregnancy (2,561) was associated with an 80% increase in prevalence of any violence and a 230% increase in partner violence. Among women who had a pregnancy, having had a miscarriage or termination was associated with violence. Partner and recent violence is strongly associated with having had a miscarriage, whether alone (OR = 2.85, 95% Cl 1.74-4.66), with a termination (OR = 4.60, 2.26-9.35), or with birth, miscarriage and a termination (OR 4.12, 1.89-9.00). Conclusions and implications: Violence among young women of childbearing age is a factor for which doctors should be vigilant, well-trained and supported to identify and manage effectively.

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The sources of covariation among cognitive measures of Inspection Time, Choice Reaction Time, Delayed Response Speed and Accuracy, and IQ were examined in a classical twin design that included 245 monozygotic (MZ) and 298 dizygotic (DZ) twin pairs. Results indicated that a factor model comprising additive genetic and unique environmental effects was the most parsimonious. In this model, a general genetic cognitive factor emerged with factor loadings ranging from 0.28 to 0.64. Three other genetic factors explained the remaining genetic covariation between various speed and Delayed Response measures with IQ. However, a large proportion of the genetic variation in verbal (54%) and performance (25%) IQ was unrelated to these lower order cognitive measures. The independent genetic IQ variation may reflect information processes not captured by the elementary cognitive tasks, Inspection Time and Choice Reaction Time, nor our working memory task, Delayed Response. Unique environmental effects were mostly nonoverlapping, and partly represented test measurement error.

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As for other complex diseases, linkage analyses of schizophrenia (SZ) have produced evidence for numerous chromosomal regions, with inconsistent results reported across studies. The presence of locus heterogeneity appears likely and may reduce the power of linkage analyses if homogeneity is assumed. In addition, when multiple heterogeneous datasets are pooled, intersample variation in the proportion of linked families ( a) may diminish the power of the pooled sample to detect susceptibility loci, in spite of the larger sample size obtained. We compare the significance of linkage. findings obtained using allele- sharing LOD scores ( LODexp) - which assume homogeneity - and heterogeneity LOD scores ( HLOD) in European American and African American NIMH SZ families. We also pool these two samples and evaluate the relative power of the LODexp and two different heterogeneity statistics. One of these ( HLOD- P) estimates the heterogeneity parameter a only in aggregate data, while the second ( HLOD- S) determines a separately for each sample. In separate and combined data, we show consistently improved performance of HLOD scores over LODexp. Notably, genome-wide significant evidence for linkage is obtained at chromosome 10p in the European American sample using a recessive HLOD score. When the two samples are combined, linkage at the 10p locus also achieves genome-wide significance under HLOD- S, but not HLOD- P. Using HLOD- S, improved evidence for linkage was also obtained for a previously reported region on chromosome 15q. In linkage analyses of complex disease, power may be maximised by routinely modelling locus heterogeneity within individual datasets, even when multiple datasets are combined to form larger samples.

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Background: Cnidarian - dinoflagellate intracellular symbioses are one of the most important mutualisms in the marine environment. They form the trophic and structural foundation of coral reef ecosystems, and have played a key role in the evolutionary radiation and biodiversity of cnidarian species. Despite the prevalence of these symbioses, we still know very little about the molecular modulators that initiate, regulate, and maintain the interaction between these two different biological entities. In this study, we conducted a comparative host anemone transcriptome analysis using a cDNA microarray platform to identify genes involved in cnidarian - algal symbiosis. Results: We detected statistically significant differences in host gene expression profiles between sea anemones ( Anthopleura elegantissima) in a symbiotic and non-symbiotic state. The group of genes, whose expression is altered, is diverse, suggesting that the molecular regulation of the symbiosis is governed by changes in multiple cellular processes. In the context of cnidarian dinoflagellate symbioses, we discuss pivotal host gene expression changes involved in lipid metabolism, cell adhesion, cell proliferation, apoptosis, and oxidative stress. Conclusion: Our data do not support the existence of symbiosis- specific genes involved in controlling and regulating the symbiosis. Instead, it appears that the symbiosis is maintained by altering expression of existing genes involved in vital cellular processes. Specifically, the finding of key genes involved in cell cycle progression and apoptosis have led us to hypothesize that a suppression of apoptosis, together with a deregulation of the host cell cycle, create a platform that might be necessary for symbiont and/or symbiont-containing host cell survival. This first comprehensive molecular examination of the cnidarian - dinoflagellate associations provides critical insights into the maintenance and regulation of the symbiosis.