Showing papers by "University of Western Australia published in 1999"
TL;DR: The results of this study support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives.
Abstract: The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of ≤ 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives.
2,513 citations
TL;DR: IHC is superior to the LBA for assessing ER status in primary breast cancer because it is easier, safer, and less expensive, and has an equivalent or better ability to predict response to adjuvant endocrine therapy.
Abstract: PURPOSE: Immunohistochemistry (IHC) is a newer technique for assessing the estrogen receptor (ER) status of breast cancers, with the potential to overcome many of the shortcomings associated with the traditional ligand-binding assay (LBA). The purpose of this study was to evaluate the ability of ER status determination by IHC, compared with LBA, to predict clinical outcome—especially response to adjuvant endocrine therapy—in a large number of patients with long-term clinical follow-up. PATIENTS AND METHODS: ER status was evaluated in 1,982 primary breast cancers by IHC on formalin-fixed paraffin-embedded tissue sections, using antibody 6F11 and standard methodology. Slides were scored on a scale representing the estimated proportion and intensity of positive-staining tumor cells (range, 0 to 8). Results were compared with ER values obtained by the LBA in the same tumors and to clinical outcome. RESULTS: An IHC score of greater than 2 (corresponding to as few as 1% to 10% weakly positive cells) was used to...
2,017 citations
TL;DR: The health sector has had its main impact in the area of dementia by providing skills and expertise necessary for comprehensive, holistic assessments, but Kitwood challenges this medical model.
Abstract: Tom Kitwood
Open University Press, £14.95, pp 176
ISBN 0335198554
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The burden of dementia is borne not only by people with dementia, but by their carers, both informal and professional. The major direct financial costs are managed by the welfare sector, through the provision of community services and residential care, whereas indirect costs are largely attributed to informal carers. Advances in care practices would be of considerable benefit. The health sector has had its main impact in the area of dementia by providing skills and expertise necessary for comprehensive, holistic assessments. Kitwood challenges this medical model, which he labels as …
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1,719 citations
TL;DR: In this paper, the authors extended previous research on perceived value by including the role of perceived risk within a model of the antecedents and consequences of perceived value and found that perceived risk played an important role in the perceived product and service quality-value for money relationship and was a significant mediator of this relationship.
1,566 citations
TL;DR: To determine the validity of short Geriatric Depression Scale (GDS) versions for the detection of a major depressive episode according to ICD‐10 criteria for research and DSM‐IV, six patients with a history of major depressive disorder were surveyed.
Abstract: Objective. To determine the validity of short Geriatric Depression Scale (GDS) versions for the detection of a major depressive episode according to ICD-10 criteria for research and DSM-IV. Design. Cross-sectional evaluation of depressive symptoms in a sample of elderly subjects with short GDS versions. DiAerent GDS cutoA points were used to estimate the sensitivity, specificity, positive predictive value and negative predictive value for the diagnosis of major depressive episode. Internal consistency of the scales was estimated with the Cronbach's alpha coeAcient. Setting. Mental Health Unit for the Elderly of 'Santa Casa' Medical School in Sao Paulo, Brazil. Participants. Sixty-four consecutive outpatients aged 60 or over who met criteria for depressive disorder (current or in remission). Subjects with severe sensory impairment, aphasia or Mini-Mental State score lower than 10 were excluded from the study. Measurements. ICD-10 Checklist of Symptoms, GDS with 15, 10, 4 and 1 items, Montgomery-Asberg Depression Rating Scale (MADRS), ICD-10 diagnostic criteria for research and DSM-IV diagnostic criteria. Results. The use of the cutoA point 4/5 for the GDS-15 produced sensitivity and specificity rates of 92.7% and 65.2% respectively, and positive and negative predictive values of 82.6% and 83.3% respectively when ICD-10 diagnostic criteria for major depressive episode were used as the 'gold standard'. Similarly, rates of 97.0%, 54.8%, 69.6% and 94.4% were found when DSM-IV was the comparing diagnostic criteria. Sensitivity, specificity and positive and negative predictive values for the cutoA point 6/7 were 80.5%, 78.3%, 86.8% and 69.2% according to ICD-10, and 84.8%, 67.7%, 73.7% and 80.8% respectively according to DSM-IV. Intermediate values were found for the cutoA point 5/6. The best fit for GDS-10 was the cutoA point 4/5, which produced a sensitivity rate of 80.5%, specificity of 78.3%, positive predictive value of 86.8% and negative predictive value of 60.2% according to ICD-10 diagnosis of a major depressive episode. Similarly, rates of 84.8%, 67.7%, 73.7% and 80.8% were found when DSM- IV criteria for major depression were used. GDS-4 cutoA point of 2/3 was associated with a sensitivity rate of 80.5%, specificity of 78.3%, positive predictive value of 86.8% and negative predictive value of 69.2% when compared to ICD-10. Again, rates of 84.8%, 67.7%, 73.7% and 80.8% respectively were found when the criteria used were based on DSM-IV. GDS-1 had low sensitivity (61.0% and 63.6% for ICD-10 and DSM-IV respectively) and negative predictive value (56.7% and 67.6% for ICD-10 and DSM-IV respectively), suggesting that this question is of limited clinical utility in screening for depression. GDS-15 (rhoa 0.82), GDS-10 (rhoa 0.82) and GDS-4 (rhoa 0.81) scores were highly correlated with subjects' scores on the MADRS. Reliability coeAcients were 0.81 for GDS-15, 0.75 for GDS-10 and 0.41 for GDS-4. Conclusion. GDS-15, GDS-10 and GDS-4 are good screening instruments for major depression as defined by both the ICD-10 and DSM-IV. The shorter four- and one-item versions are of limited clinical value due to low reliability and failure to monitor the severity of the depressive episode. General practitioners may benefit from the systematic use of short GDS versions to increase detection rates of depression among the elderly. Copyright # 1999 John Wiley & Sons, Ltd. KEY WORDS—depression; GDS; short versions; assessment; screening; diagnosis; ICD-10; DSM-IV; validity; reliability
1,150 citations
TL;DR: For more than 20 years, moderately raised concentrations of total homocysteine (tHcy) have been associated with an increased risk of atherothrombotic vascular events but only recently has evidence mounted to suggest that the association may be causal as mentioned in this paper.
1,145 citations
TL;DR: The Western Australian Health Services Research Linked Database is introduced as infrastructure to support aetlologic, utilisation and outcomes research and to compare the study population, data resources, technical systems and organisational supports with international best practice.
1,014 citations
TL;DR: The elevated levels of matrix metalloproteinase activity decreased significantly as healing occurs in chronic leg ulcers, which parallels the processes observed in normally healing acute wounds and supports the case for the addition of protease inhibitors in chronic wounds in conjunction with any treatments using growth factors.
Abstract: To assess the differences in proteolytic activity of acute and chronic wound environments, wound fluids were collected from acute surgical wounds (22 samples) and chronic wounds (25 samples) of various etiologies, including mixed vessel disease ulcers, decubiti and diabetic foot ulcers. Matrix metalloproteinase (MMP) activity measured using the Azocoll assay was significantly elevated by 30 fold in chronic wounds (median 22.8 microg MMP Eq/ml) compared to acute wounds (median 0.76 microg MMP Eq/ml) (p < 0.001). The addition of the matrix metalloproteinase inhibitor Illomostat decreased the matrix metalloproteinase activity by approximately 90% in all samples, confirming that the majority of the activity measured was due to matrix metalloproteinases. Gelatin zymograms indicated predominantly elevated matrix metalloproteinase-9 with smaller elevations of matrix metalloproteinase-2. In addition tissue inhibitor of metalloproteinase-1 levels were analyzed in a small subset of acute and chronic wounds. When tissue inhibitor of metalloproteinase-1 levels were compared to protease levels there was an inverse correlation (p = 0.02, r = - 0.78). In vitro degradation of epidermal growth factor was measured by addition of 125I labelled epidermal growth factor to acute and chronic wound fluid samples. There was significantly higher degradation of epidermal growth factor in chronic wound fluid samples (mean 28.1%) compared to acute samples (mean 0.6%). This also correlated to the epidermal growth factor activity of these wound fluid samples (p < 0. 001, r = 0.64). Additionally, the levels of proteases were assayed in wound fluid collected from 15 venous leg ulcers during a nonhealing and healing phase using a unique model of chronic wound healing in humans. Patients with nonhealing venous leg ulcers were admitted to the hospital for bed rest and wound fluid samples were collected on admission (nonhealing phase) and after 2 weeks (healing phase) when the ulcers had begun to heal as evidenced by a reduction in size (median 12%). These data showed that the elevated levels of matrix metalloproteinase activity decreased significantly as healing occurs in chronic leg ulcers (p < 0.01). This parallels the processes observed in normally healing acute wounds. This data also supports the case for the addition of protease inhibitors in chronic wounds in conjunction with any treatments using growth factors.
867 citations
TL;DR: It is explained how the face-segmentation results can be used to improve the perceptual quality of a videophone sequence encoded by the H.261-compliant coder.
Abstract: This paper addresses our proposed method to automatically segment out a person's face from a given image that consists of a head-and-shoulders view of the person and a complex background scene. The method involves a fast, reliable, and effective algorithm that exploits the spatial distribution characteristics of human skin color. A universal skin-color map is derived and used on the chrominance component of the input image to detect pixels with skin-color appearance. Then, based on the spatial distribution of the detected skin-color pixels and their corresponding luminance values, the algorithm employs a set of novel regularization processes to reinforce regions of skin-color pixels that are more likely to belong to the facial regions and eliminate those that are not. The performance of the face-segmentation algorithm is illustrated by some simulation results carried out on various head-and-shoulders test images. The use of face segmentation for video coding in applications such as videotelephony is then presented. We explain how the face-segmentation results can be used to improve the perceptual quality of a videophone sequence encoded by the H.261-compliant coder.
797 citations
TL;DR: Independent predictors of the combined outcome event of swallowing impairment, chest infection, or aspiration at 6 months were videofluoroscopic evidence of delayed oral transit and penetration into the laryngeal vestibule, age >70 years, and male sex.
Abstract: Background and Purpose—Swallowing dysfunction (dysphagia) is common and disabling after acute stroke, but its impact on long-term prognosis for potential complications and the recovery from swallowing dysfunction remain uncertain. We aimed to prospectively study the prognosis of swallowing function over the first 6 months after acute stroke and to identify the important independent clinical and videofluoroscopic prognostic factors at baseline that are associated with an increased risk of swallowing dysfunction and complications. Methods—We prospectively assembled an inception cohort of 128 hospital-referred patients with acute first stroke. We assessed swallowing function clinically and videofluoroscopically, within a median of 3 and 10 days, respectively, of stroke onset, using standardized methods and diagnostic criteria. All patients were followed up prospectively for 6 months for the occurrence of death, recurrent stroke, chest infection, recovery of swallowing function, and return to normal diet. Res...
762 citations
TL;DR: Mafic to ultramafic dykes and sills in South China, dated as 828±7 Ma old, are identical in age to the 827±6 Ma Gairdner Dyke Swarm in Australia, thought to be of mantle plume origin this paper.
TL;DR: A concordância entre os escores de itens individuais da escala foi avaliada pelo coeficiente estatistico Kappa, sugere that essas versoes tem utilidade clinica limitada.
Abstract: Depressao e problema de saude frequente entre idosos, embora a identificacao desses pacientes seja muitas vezes dificil na pratica clinica. Nesse sentido, a avaliacao sistematica dos individuos nessa faixa etaria pode contribuir para melhorar a deteccao dos casos de depressao. Este estudo foi desenhado com o objetivo de avaliar a confiabilidade de teste-reteste das versoes com 15, 10, 4, e 1 itens da Escala de Depressao em Geriatria (GDS). Foram selecionados 64 individuos com 60 ou mais anos de idade atendidos de forma consecutiva nos ambulatorios da Unidade de Idosos do Departamento de Saude Mental da Santa Casa de Sao Paulo entre fevereiro e maio de 1998. Todos preenchiam criterios para o diagnostico de transtorno depressivo (em remissao ou atual) de acordo com a CID-10 e apresentavam escores maiores do que 10 no Mini-Exame do Estado Mental. Eles foram avaliados duas vezes com a GDS-15, sendo as entrevistas conduzidas com intervalo de 48 a 72 horas. Cinquenta e um pacientes aceitaram participar do estudo. A concordância entre os escores de itens individuais da escala foi avaliada pelo coeficiente estatistico Kappa. Estes oscilaram entre 0,04 e 0,49, indicando baixa estabilidade na resposta dos pacientes. Os escores totais da GDS-15 mantiveram-se relativamente estaveis durante o reteste, conforme indicado pelo teste pareado de Wilcoxon (z=1,60; p=0,109), correlacao de Spearman (rho=0,86; p<0,001), e Kappa ponderado (Kappa=0,64). O mesmo padrao foi observado para a GDS-10 no teste de Wilcoxon (z=0,85; p=0,402), Spearman (rho=0,81; p<0,001), e Kappa ponderado (Kappa=0,60). O escore total da GDS-4 mostrou variacoes significativas do teste para o reteste (z=3,75; p<0,001; rho=0,56; p<0,001; Kappa=0,37). Esses resultados indicam que as versoes com 1 e 4 itens apresentam baixos coeficientes de confiabilidade. Isso sugere que essas versoes tem utilidade clinica limitada. Por outro lado, a GDS com 15 e 10 iitens pode ser utilizada com relativa confiabilidade na pratica clinica, particularmente quando se consideram os escores totais das escalas.
TL;DR: In this article, the authors provide guidance to help qualitative researchers use reflexivity to identify areas of potential bias and to bracket them so their influence on the research process is minimal, but the means by which this attempt was made often are not explained.
Abstract: Despite the realization that total objectivity is neither achievable nor necessarily desirable in qualitative research, researchers often are required to put aside assumptions so that the true experiences of respondents are reflected in the analysis and reporting of research. In many qualitative publications and conference presentations, researchers report that they have attempted this process, but the means by which this attempt was made often are not explicated. In this article, the author provides guidance to help qualitative researchers use reflexivity to identify areas of potential bias and to “bracket” them so their influence on the research process is minimal.
TL;DR: The results suggest that positional cloning of susceptibility loci by linkage analysis may be a formidable task and that other approaches may be necessary.
Abstract: Summary We have conducted a genome screen of autism, by linkage analysis in an initial set of 90 multiplex sibships, with parents, containing 97 independent affected sib pairs (ASPs), with follow-up in 49 additional multiplex sibships, containing 50 ASPs. In total, 519 markers were genotyped, including 362 for the initial screen, and an additional 157 were genotyped in the follow-up. As a control, we also included in the analysis unaffected sibs, which provided 51 discordant sib pairs (DSPs) for the initial screen and 29 for the follow-up. In the initial phase of the work, we observed increased identity by descent (IBD) in the ASPs (sharing of 51.6%) compared with the DSPs (sharing of 50.8%). The excess sharing in the ASPs could not be attributed to the effect of a small number of loci but, rather, was due to the modest increase in the entire distribution of IBD. These results are most compatible with a model specifying a large number of loci (perhaps ⩾15) and are less compatible with models specifying ≤10 loci. The largest LOD score obtained in the initial scan was for a marker on chromosome 1p; this region also showed positive sharing in the replication family set, giving a maximum multipoint LOD score of 2.15 for both sets combined. Thus, there may exist a gene of moderate effect in this region. We had only modestly positive or negative linkage evidence in candidate regions identified in other studies. Our results suggest that positional cloning of susceptibility loci by linkage analysis may be a formidable task and that other approaches may be necessary.
TL;DR: Eight of the 16 homozygous subjects had clinical findings that were consistent with the presence of hereditary hemochromatosis, such as hepatomegaly, skin pigmentation, and arthritis, in a population of white adults of northern European ancestry.
Abstract: Background and Methods Hereditary hemochromatosis is associated with homozygosity for the C282Y mutation in the hemochromatosis (HFE) gene on chromosome 6, elevated serum transferrin saturation, and excess iron deposits throughout the body. To assess the prevalence and clinical expression of the HFE gene, we conducted a population-based study in Busselton, Australia. In 1994, we obtained blood samples for the determination of serum transferrin saturation and ferritin levels and the presence or absence of the C282Y mutation and the H63D mutation (which may contribute to increased hepatic iron levels) in 3011 unrelated white adults. We evaluated all subjects who had persistently elevated transferrin-saturation values (45 percent or higher) or were homozygous for the C282Y mutation. We recommended liver biopsy for subjects with serum ferritin levels of 300 ng per milliliter or higher. The subjects were followed for up to four years. Results Sixteen of the subjects (0.5 percent) were homozygous for the C282Y ...
TL;DR: In this article, three clastic metasediments from the Kongling high-grade terrain of the Yangtze craton, South China were analyzed for major, trace and rare earth elements and Sm-Nd isotopic ratios.
TL;DR: Operative cholangiography has a protective effect for complications of cholecystectomy, compared with OC, which carries a nearly twofold higher risk of major bile, vascular, and bowel complications.
Abstract: BACKGROUND: Previous studies suggest that laparoscopic cholecystectomy (LC) is associated with an increased risk of intraoperative injury involving the bile ducts, bowel, and vascular structures compared with open cholecystectomy (OC). Population-based studies are required to estimate the magnitude of the increased risk, to determine whether this is changing over time, and to identify ways by which this might be reduced. METHODS: Suspected cases of intraoperative injury associated with cholecystectomy in Western Australia in the period 1988 to 1994 were identified from routinely collected hospital statistical records and lists of persons undergoing postoperative endoscopic retrograde cholangiopancreatography. The case records of suspect cases were reviewed to confirm the nature and site of injury. Ordinal logistic regression was used to estimate the risk of injury associated with LC compared with OC after adjusting for confounding factors. RESULTS: After the introduction of LC in 1991, the proportion of all cholecystectomy cases with intraoperative injury increased from 0.67% in 1988-90 to 1.33% in 1993-94. Similar relative increases were observed in bile duct injuries, major bile leaks, and other injuries to bowel or vascular structures. Increases in intraoperative injury were observed in both LC and OC. After adjustment for age, gender, hospital type, severity of disease, intraoperative cholangiography, and calendar period, the odds ratio for intraoperative injury in LC compared with OC was 1.79. Operative cholangiography significantly reduced the risk of injury. CONCLUSION: Operative cholangiography has a protective effect for complications of cholecystectomy. Compared with OC, LC carries a nearly twofold higher risk of major bile, vascular, and bowel complications. Further study is required to determine the extent to which potentially preventable factors contribute to this risk.
TL;DR: Several candidate genes in the central MHC have the potential to modulate immune or inflammatory responses in an antigen‐independent manner, as is seen in studies of cultured cells from healthy carriers of the 8.1 AH.
Abstract: An individual's major histocompatibility complex (MHC) ancestral haplotype (AH) is the clearest single determinant of susceptibility to MHC associated immunopathological disease, as it defines the alleles carried at all loci in the MHC. However, the direct effects of any of the 150-200 genes that constitute the MHC are difficult to determine since recombination only occurs at defined hotspots. This review concerns the 8.1 AH (HLA-A1, C7, B8, C4AQ0, C4B1, DR3, DQ2), which is carried by most Caucasians with HLA-B8. It is associated with accelerated human immunodeficiency virus (HIV) disease, and susceptibility to insulin-dependent diabetes mellitus (IDDM), systemic lupus erythematosus, dermatitis herpetiformis, common variable immunodeficiency and IgA deficiency, myasthenia gravis and several other conditions. We have mapped susceptibility genes for HIV, IDDM and myasthenia gravis to the central MHC between HLA-B and the tumour necrosis factor or complement genes. Here we consider which of the remaining 8.1-associated diseases are more closely associated with HLA-DR3 and/or DQ2. Several candidate genes in the central MHC have the potential to modulate immune or inflammatory responses in an antigen-independent manner, as is seen in studies of cultured cells from healthy carriers of the 8.1 AH. Hence these genes may act as a common co-factor in the diverse immunopathological conditions associated with the 8.1 AH.
TL;DR: The results indicate that the short GDS versions with 1 and 4 items are unreliable for use in clinical practice, and in contrast, the GDS with 10 and 15 items produced consistent results in the assessment of elderly patients when total scores were used as clinical guidelines.
Abstract: Depression is a frequent health problem in old age, although the detection of such cases in clinical practice is often difficult. The systematic use of depression rating scales may increase diagnostic rates of depression amongst the elderly. This study aimed to assess the test-retest reliability of short versions of the Geriatric Depression Scale (GDS) with 1, 4, 10, and 15 items. Sixty-four consecutive patients aged 60 or over attending the outpatient clinic for the elderly (UNID) at the Department of Mental Health of Santa Casa of Sao Paulo were recruited for the study between February and May 1998. All subjects fulfilled criteria for the diagnosis of a depressive disorder (current or in remission) according to ICD-10, and had Mini Mental State scores greater than 10. They were evaluated twice in 48 to 72 hours with the GDS-15. Fifty-one patients completed both assessments. Agreement between scores for individual items was evaluated with Kappa statistic. Kappa coefficients ranged from 0.04 to 0.49, indicating that there was much variation within individual items. Total GDS-15 scores were reasonably stable, as assessed by paired Wilcoxon (z = 1.60, p = 0.109), Spearman correlation coefficient (rho = 0.86, p < 0.001), and weighted Kappa (Kappa = 0.64). The same pattern was also observed for the total scores of the GDS-10 on the paired Wilcoxon (z = 0.85, p = 0.402), Spearman correlation coefficient (rho = 0.81, p < 0.001), and weighted Kappa (Kappa = 0.60). Total score for the GDS-4 showed significant changes from test to retest (z = 3.75, p < 0.001; rho = 0.56, p < 0.001; Kappa = 0.37). These results indicate that the short GDS versions with 1 and 4 items are unreliable for use in clinical practice. In contrast, the GDS with 10 and 15 items produced consistent results in the assessment of elderly patients when total scores were used as clinical guidelines.
TL;DR: In this article, an ultrastable cryogenic sapphire oscillator is used to measure the short-term frequency stability of the fountain as a function of the number of detected atoms.
Abstract: We describe the operation of a laser cooled cesium fountain clock in the quantum limited regime. An ultrastable cryogenic sapphire oscillator is used to measure the short-term frequency stability of the fountain as a function of the number of detected atoms ${N}_{\mathrm{at}}$. For ${N}_{\mathrm{at}}$ varying from $4\ifmmode\times\else\texttimes\fi{}{10}^{4}$ to $6\ifmmode\times\else\texttimes\fi{}{10}^{5}$ the Allan standard deviation of the frequency fluctuations is in excellent agreement with the ${N}_{\mathrm{at}}^{\ensuremath{-}1/2}$ law of atomic projection noise. With $6\ifmmode\times\else\texttimes\fi{}{10}^{5}$ atoms, the relative frequency stability is $4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}14}{\ensuremath{\tau}}^{\ensuremath{-}1/2}$, where \ensuremath{\tau} is the integration time in seconds. This is the best short-term stability ever reported for primary frequency standards, a factor of 5 improvement over previous results.
TL;DR: In this article, the authors used two basic approaches to assess stream ecosystem response to catchment disturbance and, particularly, to the loss of riparian vegetation in different forested biomes across Australia.
Abstract: SUMMARY 1. Measurements of ecological patterns are often used as primary biological indicators of river health. However, these patterns provide little information about important stream ecosystem processes (e.g. the sources and fate of energy and nutrients). The direct measurement of these processes is considered fundamental to the determination of the health of stream and river ecosystems. 2. In this paper we used two basic approaches to assess stream ecosystem response to catchment disturbance and, particularly, to the loss of riparian vegetation in different forested biomes across Australia. Benthic gross primary production (GPP) and respiration (R24) provided measures of the amounts of organic carbon produced and consumed within the system, respectively. Stable isotope analysis was used to trace the fate of terrestrial and instream sources of organic matter in the aquatic food web. In a focal catchment in SE Queensland, additional measurements were taken of riparian attributes, catchment features and water quality. 3. Baseline measurements of GPP and R24 from undisturbed forest streams provided reference values for healthy streams for comparison with sites where the catchment or riparian vegetation had been disturbed. These values of metabolism were low by world standards in all biomes examined. Preliminary data from the Mary River catchment in SE Queensland indicated that these parameters were sensitive to variations in riparian canopy cover and, to a lesser extent, catchment clearing, and predictive models were developed. The ratio P : R (GPP : R24) was used to determine whether sites were net consumers (P R) of carbon but this was not considered a reliable indicator of stream health on its own. 4. Although forest streams were typically net consumers of carbon (P << R), stable isotope analysis of metazoan food webs indicated a high dependence on inconspicuous epilithic algae in some biomes. 5. A dramatic decline in the health of forest streams was observed when GPP substantially exceeded R24, especially when instream primary producers shifted from palatable unicellular algae to prolific filamentous green algae and macrophytes. These sources of instream production do not appear to enter aquatic food webs, either directly through grazing or indirectly through a detrital loop. Accumulation of these plants has led to changes in channel morphology, loss of aquatic habitat and often a major decline in water quality in some of the streams studied.
TL;DR: This review of the effectiveness of treatment for acute stroke and methods of secondary prevention shows that the highest priority for providers of a stroke service must be to establish a stroke unit and multidisciplinary team that delivers organised stroke care.
TL;DR: An efficient and reliable evolutionary programming algorithm for solving the optimal power flow (OPF) problem and is enhanced with gradient information to improve the speed of convergence of the algorithm and its ability to handle larger systems.
Abstract: This paper develops an efficient and reliable evolutionary programming algorithm for solving the optimal power flow (OPF) problem. The class of curves used to describe generator performance does not limit the algorithm and the algorithm is also less sensitive to starting points. To improve the speed of convergence of the algorithm as well as its ability to handle larger systems, the algorithm is enhanced with gradient information. In the paper, the main elements of the evolutionary programming based OPF algorithm are presented. The algorithm is then demonstrated on the IEEE 30 bus test system.
TL;DR: DHA is the principal omega3 fatty acid in fish and fish oils that is responsible for their BP- and HR-lowering effects in humans, and these results have important implications for human nutrition and the food industry.
Abstract: —Animal studies suggest that the 2 major ω3 fatty acids found in fish, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may have differential effects on blood pressure (BP) and heart rate (HR). The aim of this study was to determine whether there were significant differences in the effects of purified EPA or DHA on ambulatory BP and HR in humans. In a double-blind, placebo-controlled trial of parallel design, 59 overweight, mildly hyperlipidemic men were randomized to 4 g/d of purified EPA, DHA, or olive oil (placebo) capsules and continued their usual diets for 6 weeks. Fifty-six subjects completed the study. Only DHA reduced 24-hour and daytime (awake) ambulatory BP ( P P =0.001). Relative to the placebo group, DHA reduced 24-hour HR by 3.5±0.8 bpm, daytime HR by 3.7±1.2 bpm, and nighttime HR by 2.8±1.2. EPA had no significant effect on ambulatory BP or HR. Supplementation with EPA increased plasma phospholipid EPA from 1.66±0.07% to 9.83±0.06% ( P P
TL;DR: In this paper, a review summarizes recent findings on the nature of the cellular and molecular mechanisms underlying this process, and addresses the issue of why the intensity and duration of these tissue-damaging responses in the airway wall apparently exceeds the critical threshold required for development of persistent asthma in only a minority of allergy sufferers.
Abstract: Recent studies have shown that initial sensitization to airborne environmental allergens occurs typically in early childhood, but subsequent progression to persistent atopic asthma, which may not manifest for several years, is restricted to only a subset of atopics. The key to establishing the link between atopy and asthma lies in the development of persistent inflammation in the airway wall, resulting in structural and functional changes in local tissues which are responsible for the symptoms of the disease. This review summarizes recent findings on the nature of the cellular and molecular mechanisms underlying this process, and addresses the issue of why the intensity and duration of these tissue-damaging responses in the airway wall apparently exceeds the critical threshold required for development of persistent asthma in only a minority of allergy sufferers.
TL;DR: In this article, a review of literature indicates that fertilization with inorganic and organic forms of micronutrients has a potential to increase their concentrations in grain, and that the most effective fertilization could be via soil (for Zn and, to some extent, Cu), foliarly (for Fe) and by adding fertilizers to the irrigation water (for iodine).
TL;DR: There is an association between severity of liver disease and increase in the number of oval cells consistent with the hypothesis that oval cell proliferation is associated with increased risk for development of hepatocellular carcinoma in chronic liver disease.
Abstract: The risk of developing hepatocellular carcinoma is significantly increased in patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C infection. The precise mechanisms underlying the development of hepatocellular carcinoma in these conditions are not well understood. Stem cells within the liver, termed oval cells, are involved in the pathogenesis of hepatocellular carcinoma in animal models and may be important in the development of hepatocellular carcinoma in human chronic liver diseases. The aims of this study were to determine whether oval cells could be detected in the liver of patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C, and whether there is a relationship between the severity of the liver disease and the number of oval cells. Oval cells were detected using histology and immunohistochemistry in liver biopsies from patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C. Oval cells were not observed in normal liver controls. Oval cell numbers increased significantly with the progression of disease severity from mild to severe in each of the diseases studied. We conclude that oval cells are frequently found in subjects with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C. There is an association between severity of liver disease and increase in the number of oval cells consistent with the hypothesis that oval cell proliferation is associated with increased risk for development of hepatocellular carcinoma in chronic liver disease.
Murdoch University1, University of Western Australia2, Harvard University3, University of Mainz4, University of Helsinki5, Royal Perth Hospital6, Humboldt University of Berlin7, University of Sydney8, University of Würzburg9, Hammersmith Hospital10, Boston Children's Hospital11, University of South Florida12
TL;DR: Mutations in the human skeletal muscle α-actin gene (ACTA1) are associated with two different muscle diseases, 'congenital myopathy with excess of thin myofilaments' (actin myopathy) and nemaline myopathy, characterized by structural abnormalities of the muscle fibres and variable degrees of muscle weakness.
Abstract: Muscle contraction results from the force generated between the thin filament protein actin and the thick filament protein myosin, which causes the thick and thin muscle filaments to slide past each other. There are skeletal muscle, cardiac muscle, smooth muscle and non-muscle isoforms of both actin and myosin. Inherited diseases in humans have been associated with defects in cardiac actin (dilated cardiomyopathy and hypertrophic cardiomyopathy), cardiac myosin (hypertrophic cardiomyopathy) and non-muscle myosin (deafness). Here we report that mutations in the human skeletal muscle alpha-actin gene (ACTA1) are associated with two different muscle diseases, 'congenital myopathy with excess of thin myofilaments' (actin myopathy) and nemaline myopathy. Both diseases are characterized by structural abnormalities of the muscle fibres and variable degrees of muscle weakness. We have identified 15 different missense mutations resulting in 14 different amino acid changes. The missense mutations in ACTA1 are distributed throughout all six coding exons, and some involve known functional domains of actin. Approximately half of the patients died within their first year, but two female patients have survived into their thirties and have children. We identified dominant mutations in all but 1 of 14 families, with the missense mutations being single and heterozygous. The only family showing dominant inheritance comprised a 33-year-old affected mother and her two affected and two unaffected children. In another family, the clinically unaffected father is a somatic mosaic for the mutation seen in both of his affected children. We identified recessive mutations in one family in which the two affected siblings had heterozygous mutations in two different exons, one paternally and the other maternally inherited. We also identified de novo mutations in seven sporadic probands for which it was possible to analyse parental DNA.
TL;DR: The majority of the data support a direct role for the T NF2 ‐308 allele in the elevated TNF levels observed in TNF2 homozygotes and HLA‐A1, B8, DR3 individuals.
Abstract: A biallelic G (TNF1 allele) to A (TNF2 allele) polymorphism 308 nucleotides upstream from the transcription initiation site in the tumor necrosis factor (TNF) promoter is associated with elevated TNF levels and disease susceptibilities observed in human subjects. The TNF2 allele is strongly associated with the high-TNF-producing autoimmune MHC haplotype HLA-A1, B8, DR3, with elevated serum TNF levels and a more severe outcome in infectious diseases, such as cerebral malaria. A number of groups have set out to determine whether the -308 polymorphism could affect transcription factor binding and hence influence TNF transcription and expression levels. Although some studies have failed to show any functional difference between the two allelic forms, others have shown that the -308 polymorphism effected transcription factor binding to the region encompassing -308, with the region in the TNF2 allele showing altered binding characteristics. The -308 polymorphism also has been found by some groups to be functionally significant in reporter gene assays in Raji B cells, Jurkat T cells, and U937 pre-monocytic cells. Up to fivefold differences can be measured between TNF1 and TNF2 allelic constructs when the TNF 3'UTR is present, indicating a role in the expression of the polymorphism. Although controversial, the majority of the data support a direct role for the TNF2 -308 allele in the elevated TNF levels observed in TNF2 homozygotes and HLA-A1, B8, DR3 individuals. Elevated TNF levels due to the -308 polymorphism may alter the immune response such that it confers susceptibility to certain autoimmune and infectious diseases.
TL;DR: It is shown that activation of PAR2, which co-localizes immunohistochemically with trypsin(ogen) in airway epithelium, causes the relaxation of airway preparations from mouse, rat, guinea-pig and humans by the release of a cyclooxygenase product from the epithelia.
Abstract: The protection of cells in the upper intestine against digestion by pancreatic trypsin depends on the prostanoid prostaglandin E2 (PGE2) and is mediated by protease-activated receptors in the epithelium. As the airway epithelium is morphologically similar and also expresses one of these receptors, PAR2, and is a major source of PGE2, we reasoned that bronchial epithelial PAR2 might also participate in prostanoid-dependent cytoprotection in the airways. Here we show that activation of PAR2, which co-localizes immunohistochemically with trypsin(ogen) in airway epithelium, causes the relaxation of airway preparations from mouse, rat, guinea-pig and humans by the release of a cyclooxygenase product from the epithelium. This physiological protective response in isolated airways also occurred in anaesthetized rats, where activation of PAR2 caused a marked and prolonged inhibition of bronchoconstriction. After desensitization of PAR2, the response to trypsin recovered rapidly by mechanisms dependent on de novo synthesis and trafficking of proteins. Our results indicate that trypsin released from the epithelium can initiate powerful bronchoprotection in the airways by activation of epithelial PAR2.