Data Available (data + available)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Data Available

  • experimental data available
  • limited data available
  • little data available

  • Selected Abstracts

    The relationship between baseline value and its change: problems in categorization and the proposal of a new method

    Yu-Kang Tu
    Oral health researchers have shown great interest in the relationship between the initial status of diseases and subsequent changes following treatment. Two main approaches have been adopted to provide evidence of a positive association between baseline values and their changes following treatment. One approach is to use correlation or regression to test the relationship between baseline measurements and subsequent change (correlation/regression approach). The second approach is to categorize the lesions into subgroups, according to threshold values, and subsequently compare the treatment effects across the two (or more) subgroups (categorization approach). However, the correlation/regression approach suffers a methodological weakness known as mathematical coupling. Consequently, the statistical procedure of testing the null hypothesis becomes inappropriate. Categorization seems to avoid the problem of mathematical coupling, although it still suffers regression to the mean. We show, first, how the appropriate null hypothesis may be established to analyze the relationship between baseline values and change in the correlation approach and, second, we use computer simulations to investigate the impact of regression to the mean on the significance testing of the differences in the average treatment effects (or average baseline values) in the categorization approach. Data available from previous literature are reanalyzed by testing the appropriate null hypotheses and the results are compared to those from testing the usual (incorrect) null hypothesis. The results indicate that both the correlation and categorization approaches can give rise to misleading conclusions and that more appropriate methods, such as Oldham's method and our new approach of deriving the correct null hypothesis, should be adopted. [source]

    Minimizing the release of proinflammatory and toxic bacterial products within the host: A promising approach to improve outcome in life-threatening infections

    Roland Nau
    Abstract Various bacterial components (e.g., endotoxin, teichoic and lipoteichoic acids, peptidoglycans, DNA) induce or enhance inflammation by stimulating the innate immune system and/or are directly toxic in eukariotic cells (e.g., hemolysins). When antibiotics which inhibit bacterial protein synthesis kill bacteria, smaller quantities of proinflammatory or toxic compounds are released in vitro and in vivo than during killing of bacteria by ,-lactams and other cell-wall active drugs. In general, high antibiotic concentrations liberate lower quantities of bacterial proinflammatory or toxic compounds than concentrations close to the minimum inhibitory concentration. In animal models of Escherichia coli Pseudomonas aeruginosa and Staphylococcus aureus peritonitis/sepsis and of Streptococcus pneumoniae meningitis, a lower release of proinflammatory bacterial compounds was associated with a reduced mortality or neuronal injury. Pre-treatment with a bacterial protein synthesis inhibitor reduced the strong release of bacterial products usually observed during treatment with a ,-lactam antibiotic. Data available strongly encourage clinical trials comparing antibiotic regimens with different release of proinflammatory/toxic bacterial products. The benefit of the approach to reduce the liberation of bacterial products should be greatest in patients with a high bacterial load. [source]

    Treatment of ulcerative colitis from the patient's perspective: a survey of preferences and satisfaction with therapy

    J. R. GRAY
    Summary Background, Data available regarding patient perspectives on ulcerative colitis (UC) and their preferences and satisfaction with therapy are limited. Aims, To examine the preferences of UC patients to understand better what they look for in a therapy when managing their disease, as this may influence overall medication adherence. Methods, The study surveyed 100 Canadian UC patients on topics including educational resources used to learn about the disease, medication attributes that are most valued and preferred by the patient and satisfaction with current therapy. Results, Overall, efficacy- and safety-related medication attributes were rated by patients to be more important than those related to dosing regimen (e.g. dosing frequency, number of pills), cost and formulary coverage. In pair-wise comparisons of specific medication attributes, UC patients rated speed of symptom relief and few side effects as the most important factors when considering a UC medication (preferred on average 84% and 74% of the time respectively). Conclusion, This study provides insight into UC patient preferences and satisfaction with therapy that may be important when counselling on treatment options, and generates relevant discussions on adherence. Larger studies may be warranted to examine further how these findings can be extrapolated to broader UC populations. [source]

    Gas Hold-Up in Stirred Tank Reactors in the Presence of Inorganic Electrolytes

    Archis A. Yawalkar
    Abstract Gas hold-up (,G) in air-aqueous electrolyte solutions in stirred tank reactors (STR) is correlated using a relative gas dispersion parameter, N/Ncd and a surface tension factor (STF), (c/z)(d,/dc)2. For electrolyte concentration below transition concentration (ct) a single correlation in the form of ,G = f(N/Ncd, vvm, STF) shows good agreement with gas hold-up data over a wide range of system and operating conditions. Above ct no effect of STF on gas hold-up is observed and the correlation obtained is of the form ,G = f(N/Ncd, vvm). Data available in the literature on large STR show good fit with the proposed correlation. On a corrélé la rétention de gaz (,G) dans un mélange air-solutions d'électrolytes aqueuses dans des réacteurs à réservoir agité (RRA) à l'aide d'un paramètre de dispersion de gaz, N/Ncd, et d'un facteur de tension de surface (FTS), (c/z)(d,/dc)2. Pour une concentration d'électrolytes en-dessous de la concentration de transition (ct), une corrélation simple sous la forme ,G = f(N/Ncd, vvm, STF) montre un bon accord avec les données de rétention de gaz pour une vaste gamme de conditions de systèmes et de fonctionnement. Au-dessus de ct, on observe aucun effet du STF sur la rétention de gaz et la corrélation obtenue est de la forme ,G = f(N/Ncd, vvm). Les données disponibles dans la littérature scientifique sur des RRA de grande taille montrent un bon accord avec la corrélation proposée. [source]

    Seedling establishment, mortality, tree growth rates and vigour of Acacia nilotica in different Astrebla grassland habitats: Implications for invasion

    AUSTRAL ECOLOGY, Issue 3 2002
    Ian J. Radford
    Abstract A demographic study was conducted in the northern Australian Astrebla grasslands to determine the importance of habitat type in influencing invasion patterns of Acacia nilotica, an exotic leguminous tree from Africa and Asia. One of the repeated patterns observed for A. nilotica is that denser populations are often associated with riparian habitats. Data available on this species do not enable us to determine which of a number of processes has lead to the formation of this pattern. Several explanations were tested for patterns in tree abundance: (i) that more seedlings emerge in wetter habitats; (ii) that mortality is lower in wetter habitats; (iii) that growth rates are faster in wetter habitats; and (iv) that plants are more vigorous (as indicated by leaf cover, flowering intensity and predation rates) over longer periods in wetter habitats. The study was stratified across three habitat types, perennial and ephemeral riparian and non-riparian, which are characteristic of Astrebla grasslands and differentiated by the availability of water. In addition to testing for habitat-linked differentiation in demography, data were also used to test whether seedling emergence, mortality, growth and vigour varied between sites with cattle versus sheep. The data collected indicated that seedling emergence, determined primarily by livestock dispersal, was likely to be the dominant influence on patterns of A. nilotica invasion. Mortality and growth rates were similar in ephemeral riparian and non-riparian habitats, whereas perennial riparian habitats had more rapid growth rates, which may increase the rate of invasion in these areas. Plant vigour was also greater over longer periods in perennial riparian habitats with greater leaf cover, longer flowering season and fewer insect borer holes. Livestock species were found to have little influence on the demography of A. nilotica plants in this study. Very low growth rates and high mortality in A. nilotica populations are likely to lead to net decline in ephemeral riparian and non-riparian habitats in the long term. The importance of episodic recruitment in the maintenance of A. nilotica populations is discussed. [source]

    Consideration of the Effect of Irregular Catalytic Active Component Distributions in Mesopores , Extension of a Model for Wall Catalyzed Reactions in Microchannel Reactors

    B. Platzer
    Abstract Data available from the literature and experimental results have shown that the distribution of the catalytic active components can be irregular already for fresh catalysts. The determination of the local concentrations of the catalytic active components using wavelength dispersive X-ray spectroscopy confirms this for microstructured wafers used in microchannel reactors. Considering this nonuniform distribution, the used model gives the relation between the local concentration profiles of the reactants inside the pores and the product yield in the entire pore. These results were used in an equation for the diffusion flux at the pore mouth, which is useful for a microchannel model developed in a recent paper [1]. The theoretical considerations deal with cylindrical pores with known reactant concentrations at the pore mouth and known distribution of the catalytic active component within the pore. Beside numerical results, some analytical solutions with low mathematical expense, applicable to special cases, are discussed. The nonconsideration of the irregular distribution of the catalytic active component can be the reason for difficulties during the extrapolation of experimental results to slightly different conditions and can have a great influence on the reaction results. The regarded examples are typical of wall-catalyzed reactions in microchannel reactors with mesopores. [source]

    Foetal size to final height

    ACTA PAEDIATRICA, Issue 6 2000
    J Karlberg
    It is well known that some adult diseases, such as cardiovascular diseases, may be programmed during foetal life. It is not clear, however, whether final height may be predicted from foetal growth. A longitudinal cohort of full-term healthy Swedish babies (n = 3650) was followed up from birth to maturity in a population-based growth study. Length or height and its changes were analysed from birth to 18 y of age; 2807 children, with data available on birth length, final height and parental height, were included in this analysis. The result clearly shows that length at birth relates to final height. In terms of standard deviation scores (SDS), the mean difference in length at birth from the mean was greatly decreased in final height, but retained the same order as was seen at birth. In terms of centimeter difference from the reference mean values, the difference in length at birth remained roughly stable into final height. For instance, babies 5 cm above or below the mean birth length will end up approximately 5 cm above or below the mean in final height. Parental height,a surrogate value of the genetic final height potential of an individual,is shown to influence postnatal growth in height strongly. However, the difference from the mean in length at birth remained into adulthood within the same midparental height group. Conclusion: This study reveals that trends in foetal linear growth continue into maturity. Foetal growth is a significant predictor of postnatal growth. Final height is dependent on both the magnitude of foetal growth and the genetic potential in stature, and appears to some extent to be programmed from foetal growth. [source]

    One Hundred Fifty Years of Change in Forest Bird Breeding Habitat: Estimates of Species Distributions

    aptitud del hábitat; ecología aviar; ecología de paisaje; planificación de conservación Abstract:,Evaluating bird population trends requires baseline data. In North America the earliest population data available are those from the late 1960s. Forest conditions in the northern Great Lake states (U.S.A.), however, have undergone succession since the region was originally cut over around the turn of the twentieth century, and it is expected that bird populations have undergone concomitant change. We propose pre-Euro-American settlement as an alternative baseline for assessing changes in bird populations. We evaluated the amount, quality, and distribution of breeding bird habitat during the mid-1800s and early 1990s for three forest birds: the Pine Warbler (Dendroica pinus), Blackburnian Warbler (D. fusca), and Black-throated Green Warbler (D. virens). We constructed models of bird and habitat relationships based on literature review and regional data sets of bird abundance and applied these models to widely available vegetation data. Original public-land survey records represented historical habitat conditions, and a combination of forest inventory and national land-cover data represented current conditions. We assessed model robustness by comparing current habitat distribution to actual breeding bird locations from the Wisconsin Breeding Bird Atlas. The model showed little change in the overall amount of Pine Warbler habitat, whereas both the Blackburnian Warber and the Black-throated Green Warbler have experienced substantial habitat losses. For the species we examined, habitat quality has degraded since presettlement and the spatial distribution of habitat shifted among ecoregions, with range expansion accompanying forest incursion into previously open habitats or the replacement of native forests with pine plantations. Sources of habitat loss and degradation include loss of conifers and loss of large trees. Using widely available data sources in a habitat suitability model framework, our method provides a long-term analysis of change in bird habitat and a presettlement baseline for assessing current conservation priority. Resumen:,La evaluación de tendencias de las poblaciones de aves requiere de datos de referencia. En Norte América, los primeros datos disponibles de poblaciones son del final de la década de 1960. Sin embargo, las condiciones de los bosques en los estados de los Grandes Lagos (E.U.A.) han experimentado sucesión desde que la región fue talada en los inicios del siglo veinte, y se espera que las poblaciones de aves hayan experimentado cambios concomitantes. Proponemos que se considere al período previo a la colonización euro americana como referencia alternativa para evaluar los cambios en las poblaciones de aves. Evaluamos la cantidad, calidad y distribución del hábitat para reproducción de tres especies de aves de bosque (Dendroica pinus, D. fusca y D. virens) a mediados del siglo XIX e inicios del XX. Construimos modelos de las relaciones entre las aves y el hábitat con base en la literatura y conjuntos de datos de abundancia de aves y los aplicamos a los datos de vegetación ampliamente disponibles. Los registros topográficos de tierras públicas originales representaron las condiciones históricas del hábitat, y una combinación de datos del inventario forestal y de cobertura de suelo representaron las condiciones actuales. Evaluamos la robustez del modelo mediante la comparación de la distribución de hábitat actual con sitios de reproducción de aves registrados en el Wisconsin Breeding Bird Atlas. El modelo mostró poco cambio en la cantidad total de hábitat de Dendroica pinus, mientras que tanto D. fusca como D. virens han experimentado pérdidas sustanciales de hábitat. Para las especies examinadas, la calidad del hábitat se ha degradado desde antes de la colonización y la distribución espacial del hábitat cambió entre ecoregiones, con la expansión del rango acompañando la incursión de bosques en hábitats anteriormente abiertos o el reemplazo de bosques nativos con plantaciones de pinos. Las fuentes de pérdida y degradación de hábitats incluyen la pérdida de coníferas y de árboles grandes. Mediante la utilización de fuentes de datos ampliamente disponibles en un modelo de aptitud de hábitat, nuestro método proporciona un análisis a largo plazo de los cambios en el hábitat de aves y una referencia precolonización para evaluar prioridades de conservación actuales. [source]

    Temperate marine reserves: global ecological effects and guidelines for future networks

    Gavin B. Stewart
    Abstract Marine reserves, areas closed to all fishing and other extractive activities, provide a refuge for species of commercial and conservation importance. Given the considerable resources committed to designing temperate reserve networks, we synthesized data from temperate reserves worldwide to determine their ecological effects. In common with other studies, we found higher density, biomass, and species richness in temperate marine reserves compared to adjacent exploited areas. However, there was considerable heterogeneity in magnitude of effect among reserves, variability which was largely unexplained by species or reserve characteristics. Our analytical approach allowed for formal power analyses, indicating that detection of large reserve effects in temperate systems globally requires monitoring at least 37 reserves. These results must be qualified by the limitations of data available and will undoubtedly vary at different spatio-temporal scales and for different focal species, but provide guidance for the design and monitoring of future marine conservations plans. International commitments toward establishment of multiple reserves offer a unique opportunity to assess reserve effectiveness; this opportunity can only be realized if reserves are designed to achieve clear and quantifiable objectives and are adequately monitored before and after establishment, based on appropriate power analyses, to assess how well those objectives are achieved. [source]

    Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy

    CONTACT DERMATITIS, Issue 1 2010
    Part 1.
    In this part of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy, formaldehyde-releasers in cosmetics are discussed. In this first part of the article, key data are presented including frequency of sensitization and of their use in cosmetics. In Europe, low frequencies of sensitization have been observed to all releasers: 2-bromo-2-nitropropane-1,3-diol 0.4,1.2%, diazolidinyl urea 0.5,1.4%, imidazolidinyl urea 0.3,1.4%, quaternium-15 0.6,1.9% (for DMDM hydantoin no recent data are available). All releasers score (far) higher prevalences in the USA; the possible explanations for this are discussed. The relevance of positive patch test reactions has been insufficiently investigated. In the USA, approximately 20% of cosmetics and personal care products (stay-on products: 17%, rinse-off products 27%) contain a formaldehyde-releaser. The use of quaternium-15 is decreasing. For Europe, there are no comparable recent data available. In the second part of the article, the patch test relationship of the releasers in cosmetics to formaldehyde contact allergy will be reviewed and it will be assessed whether products preserved with formaldehyde-releasers may contain enough free formaldehyde to pose a threat to individuals who have contact allergy to formaldehyde. [source]

    Patterns of precursor behaviors in the life span of a U.S. environmental terrorist group

    Brent L. Smith
    Research Summary This article discusses the paucity of data available for assessing the "life span" of a terrorist group. It introduces a new methodology that allows researchers to examine when terrorist groups perform their preincident activities. The findings suggest that differences exist in the temporal patterns of terrorist groups: environmental terrorist groups engage in a relatively short planning cycle compared with right-wing and international terrorists. The article concludes by examining a case study on "the Family," which is a unique environmental terrorist group that conducted activities over a relatively long period of time. This group provides an interesting contrast to other environmental terrorists. Despite significant organizational differences, their patterns of preparatory conduct were highly similar. Policy Implications The findings suggest that (1) temporal and spatial data about preincident terrorist activity can be collected from unclassified and open sources and (2) law-enforcement agencies that are investigating environmental groups have relatively little time to observe and infiltrate their individual cells (compared with right-wing and international terrorists). Finally, the data suggest that environmental terrorists,at least so far,have engaged in attacks that are less deadly than the comparison groups. [source]

    Metrics in the Science of Surge

    Jonathan A. Handler MD
    Metrics are the driver to positive change toward better patient care. However, the research into the metrics of the science of surge is incomplete, research funding is inadequate, and we lack a criterion standard metric for identifying and quantifying surge capacity. Therefore, a consensus working group was formed through a "viral invitation" process. With a combination of online discussion through a group e-mail list and in-person discussion at a breakout session of the Academic Emergency Medicine 2006 Consensus Conference, "The Science of Surge," seven consensus statements were generated. These statements emphasize the importance of funded research in the area of surge capacity metrics; the utility of an emergency medicine research registry; the need to make the data available to clinicians, administrators, public health officials, and internal and external systems; the importance of real-time data, data standards, and electronic transmission; seamless integration of data capture into the care process; the value of having data available from a single point of access through which data mining, forecasting, and modeling can be performed; and the basic necessity of a criterion standard metric for quantifying surge capacity. Further consensus work is needed to select a criterion standard metric for quantifying surge capacity. These consensus statements cover the future research needs, the infrastructure needs, and the data that are needed for a state-of-the-art approach to surge and surge capacity. [source]

    Sentinel Lymph Node Biopsy in Cutaneous Squamous Cell Carcinoma: A Systematic Review of the English Literature

    BACKGROUND Although most cutaneous squamous cell carcinoma (SCC) is curable by a variety of treatment modalities, a small subset of tumors recur, metastasize, and result in death. Although risk factors for metastasis have been described, there are little data available on appropriate workup and staging of patients with high-risk SCC. OBJECTIVE We reviewed reported cases and case series of SCC in which sentinel lymph node biopsy (SLNB) was performed to determine whether further research is warranted in developing SLNB as a staging tool for patients with high-risk SCC. METHODS The English medical literature was reviewed for reports of SLNB in patients with cutaneous SCC. Data from anogenital and nonanogenital cases were collected and analyzed separately. The percentage of cases with a positive sentinel lymph node (SLN) was calculated. False negative and nondetection rates were tabulated. Rates of local recurrence, nodal and distant metastasis, and disease-specific death were reported. RESULTS A total of 607 patients with anogenital SCC and 85 patients with nonanogenital SCC were included in the analysis. A SLN could not be identified in 3% of anogenital and 4% of nonanogenital cases. SLNB was positive in 24% of anogenital and 21% of nonanogenital patients. False-negative rates as determined by completion lymphadenectomy were 4% (8/213) and 5% (1/20), respectively. Most false-negative results were reported in studies from 2000 or earlier in which the combination of radioisotope and blue dye was not used in the SLN localization process. Complications were reported rarely and were limited to hematoma, seroma, cutaneous lymphatic fistula, wound infection, and dehiscence. CONCLUSIONS Owing to the lack of controlled studies, it is premature to draw conclusions regarding the utility of SLNB in SCC. The available data, however, suggest that SLNB accurately diagnoses subclinical lymph node metastasis with few false-negative results and low morbidity. Controlled studies are needed to demonstrate whether early detection of subclinical nodal metastasis will lead to improved disease-free or overall survival for patients with high-risk SCC. [source]

    Financial Liberalisation in Southern Africa: An Assessment

    Obert Nyawata
    In the early 1990s many Southern African economies embarked on financial liberalisation. Although it is too soon to carry out sophisticated econometric analysis of this change in policy, the available empirical evidence may be inspected to see whether it lends support to advocates of financial liberalisation. In this article we explore the avenues through which financial liberalisation might be expected to exert an influence. Consistent with much of the existing literature, we discover that a degree of agnosticism is warranted. Financial liberalisation is no panacea and will not improve economic performance unless accompanied by sound economic policies. It remains difficult to isolate the effects of financial liberalisation from the data available. [source]

    Evolutionary conservation and divergence of the segmentation process in arthropods

    Wim G. M. Damen
    Abstract A fundamental characteristic of the arthropod body plan is its organization in metameric units along the anterior,posterior axis. The segmental organization is laid down during early embryogenesis. Our view on arthropod segmentation is still strongly influenced by the huge amount of data available from the fruit fly Drosophila melanogaster (the Drosophila paradigm). However, the simultaneous formation of the segments in Drosophila is a derived mode of segmentation. Successive terminal addition of segments from a posteriorly localized presegmental zone is the ancestral mode of arthropod segmentation. This review focuses on the evolutionary conservation and divergence of the genetic mechanisms of segmentation within arthropods. The more downstream levels of the segmentation gene network (e.g., segment polarity genes) appear to be more conserved than the more upstream levels (gap genes, Notch/Delta signaling). Surprisingly, the basally branched arthropod groups also show similarities to mechanisms used in vertebrate somitogenesis. Furthermore, it has become clear that the activation of pair rule gene orthologs is a key step in the segmentation of all arthropods. Important findings of conserved and diverged aspects of segmentation from the last few years now allow us to draw an evolutionary scenario on how the mechanisms of segmentation could have evolved and led to the present mechanisms seen in various insect groups including dipterans like Drosophila. Developmental Dynamics 236:1379,1391, 2007. © 2007 Wiley-Liss, Inc. [source]

    Does ethnic origin have an independent impact on hypertension and diabetic complications?

    V. Baskar
    Aim:, The morbidity and mortality from cardiovascular complications in diabetes reputedly differ with ethnicity. We have evaluated the prevalence of hypertension and vascular complications amongst Afro-Caribbean (AC), Caucasian (C) and Indo-Asian (IA) ethnic subgroups of a district's diabetes population to estimate the impact of ethnic origin as an independent risk variable. Methods:, Of the 6485 registered adult individuals, 6047 had ethnic data available and belonged to one of the three ethnic groups described (AC 9%, C 70% and IA 21%). Statistical analyses were performed using spss version 11.5. Results:, Results are presented as mean ± s.d. or percentage. IAs were younger (AC 63 ± 13, C 61 ± 15 and IA 57 ± 13 years), were less obese (body mass index 30 ± 8, 29 ± 9, 28 ± 6 kg/cm2) and had lower systolic blood pressure (155 ± 25, 149 ± 24, 147 ± 24 mmHg) and lower prevalence of hypertension (82%, 74% and 68%) compared with C, who had lower values than AC (all p < 0.01). Relative to C group, the AC group had higher prevalence of hypertension and microvascular complications but lower macrovascular disease burden, while the IA group had lower hypertension and macrovascular complications but with comparable microvascular disease burden [microvascular (51%, 44% and 46%; p < 0.01) and macrovascular (33%, 40% and 32%; p < 0.001)]. On logistic regression, this effect of ethnic origin on diabetic complications was found to be significant and independent of other risk variables. Conclusion:, Hypertension and diabetic complication rates were different amongst ethnic subgroups. On logistic regression, it was found that the difference in distribution of age and diabetes duration largely accounted for this difference, although ethnic origin remained an independent risk factor. [source]

    A new dimension in combining data?

    ACTA ZOOLOGICA, Issue 1 2010
    The use of morphology, phylogenomic data in metazoan systematics
    Abstract Giribet, G. 2010. A new dimension in combining data? The use of morphology and phylogenomic data in metazoan systematics. ,Acta Zoologica (Stockholm) 91: 11,19 Animal phylogenies have been traditionally inferred by using the character state information derived from the observation of a diverse array of morphological and anatomical features, but the incorporation of molecular data into the toolkit of phylogenetic characters has shifted drastically the way researchers infer phylogenies. A main reason for this is the ease at which molecular data can be obtained, compared to, e.g., traditional histological and microscopical techniques. Researchers now routinely use genomic data for reconstructing relationships among animal phyla (using whole genomes or Expressed Sequence Tags) but the amount of morphological data available to study the same phylogenetic patterns has not grown accordingly. Given the disparity between the amounts of molecular and morphological data, some authors have questioned entire morphological programs. In this review I discuss issues related to the combinability of genomic and morphological data, the informativeness of each set of characters, and conclude with a discussion of how morphology could be made scalable by utilizing new techniques that allow for non-intrusive examination of large amounts of preserved museum specimens. Morphology should therefore remains a strong field in evolutionary and comparative biology, as it continues to provide information for inferring phylogenetic patterns, is an important complement for the patterns derived from the molecular data, and it is the common nexus that allows studying fossil taxa with large data sets of molecular data. [source]

    Combined treatment of achalasia , botulinum toxin injection followed by pneumatic dilatation: long-term results

    R. Kroupa
    SUMMARY Injection of botulinum toxin (BT) and pneumatic dilatation are available methods in nonsurgical treatment of achalasia. Authors anticipate beneficial effect of prior BT injection on the success of pneumatic dilatation and duration of its effect. There are no long-term data available to assess efficacy of combined treatment. From 1998 to 2007, 51 consecutive patients (20 men and 31 women, age 24,83) with achalasia were included and prospectively followed up. Each patient received injection of 200 IU of BT into the lower esophageal sphincter (LES) during endoscopy and 8 days later pneumatic dilatation (PD) under X-ray control was performed. The follow-up was established every 3 months first year and then annually. The efficacy was evaluated by a questionnaire concerning patient's symptoms and manometry. Results were compared with 40 historical controls (16 men and 24 women, age 26,80) treated by PD alone using the same method and follow-up. Fifty-one patients underwent combined treatment. Four patients failed in follow-up and were not included for analysis. The mean duration of follow-up was 48 months with range 12,96 months. Thirty-four of forty-seven (72%) patients were satisfied with results with none or very rare and mild troubles at the time of the last visit. Forty-one patients were followed up more than 2 years. Effect of therapy lasted in 75% (31/41) of them. In 17 patients, more than 5 years after treatment, effect lasted in 12 (70%). Mean tonus of LES before therapy was 29 mm Hg (10,80), 3 months after therapy decreased to 14 mmHg (5,26). The cumulative 5 years remission rate (±95% CI) in combined treated patients 69% ± 8% was higher than in controls 50% ± 9%; however it, was not statistically significant (P= 0.07). In control group 1, case of perforation (2.5%) occurred. Eight patients (17%) with relapse of dysphagia were referred to laparoscopic Heller myotomy with no surgical complication. The main adverse effect was heartburn that appeared in 17 patients (36%). Initial injection of BT followed by PD seems to be effective for long-term results with fewer complications. But the combined therapy is not significantly superior to PD alone. [source]

    Climate, climate change and range boundaries

    Chris D. Thomas
    Abstract Aim, A major issue in ecology, biogeography, conservation biology and invasion biology is the extent to which climate, and hence climate change, contributes to the positions of species' range boundaries. Thirty years of rapid climate warming provides an excellent opportunity to test the hypothesis that climate acts as a major constraint on range boundaries, treating anthropogenic climate change as a large-scale experiment. Location, UK and global data, and literature. Methods, This article analyses the frequencies with which species have responded to climate change by shifting their range boundaries. It does not consider abundance or other changes. Results, For the majority of species, boundaries shifted in a direction that is concordant with being a response to climate change; 84% of all species have expanded in a polewards direction as the climate has warmed (for the best data available), which represents an excess of 68% of species after taking account of the fact that some species may shift in this direction for non-climatic reasons. Other data sets also show an excess of animal range boundaries expanding in the expected direction. Main conclusions, Climate is likely to contribute to the majority of terrestrial and freshwater range boundaries. This generalization excludes species that are endemic to specific islands, lakes, rivers and geological outcrops, although these local endemics are not immune from the effects of climate change. The observed shifts associated with recent climate change are likely to have been brought about through both direct and indirect (changes to species' interactions) effects of climate; indirect effects are discussed in relation to laboratory experiments and invasive species. Recent observations of range boundary shifts are consistent with the hypothesis that climate contributes to, but is not the sole determinant of, the position of the range boundaries of the majority of terrestrial animal species. [source]

    Executive functions in children with dyslexia

    DYSLEXIA, Issue 2 2005
    Astrid Reiter
    Abstract There is little data available concerning the executive functions of children with dyslexia. The small number of existing studies in this field focus on single aspects of these functions such as working memory. The aim of the present study was therefore to assess a variety of aspects of executive functioning in children with dyslexia. Forty-two children with dyslexia and 42 non-dyslexic children were examined using a neuropsychological test battery. The test battery consisted of standardised tests examining the assessment of working memory, concept formation, inhibition, flexibility, problem solving and fluency functions. Comparison between the test performance of non-dyslexic children and children with dyslexia revealed obvious difficulties of children with dyslexia in tests measuring working memory. Inhibition of inappropriate reactions was impaired in children with dyslexia in more demanding tests, but not in simple ones. Furthermore, children with dyslexia displayed impairments of both verbal and figural fluency functions. While in comparison to non-dyslexic children no disturbances of concept formation were observed, problem solving seemed to be partially impaired. The present findings suggest that children with dyslexia demonstrate impairments in a variety of executive functions. This should be considered in the development of new concepts in the treatment of dyslexia. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Bridging the gap between field data and global models: current strategies in aeolian research

    Joanna Bullard
    Abstract Modern global models of earth-atmosphere-ocean processes are becoming increasingly sophisticated but still require validation against empirical data and observations. This commentary reports on international initiatives amongst aeolian researchers that seek to combine field-based data sets and geomorphological frameworks for improving the quality of data available to constrain and validate global models. These include a second iteration of the Dust Indicators and Records from Terrestrial Marine Palaeoenvironments (DIRTMAP2) database, the Digital Atlas of Sand Seas and Dunefields of the World and a new geomorphology-based land surface map produced by the QUEST (Quantifying Uncertainties in the Earth System) Working Group on Dust. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    A model for the 3D kinematic interaction analysis of pile groups in layered soils

    Francesca Dezi
    Abstract The paper presents a numerical model for the analysis of the soil,structure kinematic interaction of single piles and pile groups embedded in layered soil deposits during seismic actions. A finite element model is considered for the pile group and the soil is assumed to be a Winkler-type medium. The pile,soil,pile interaction and the radiation problem are accounted for by means of elastodynamic Green's functions. Condensation of the problem permits a consistent and straightforward derivation of both the impedance functions and the foundation input motion, which are necessary to perform the inertial soil,structure interaction analyses. The model proposed allows calculating the internal forces induced by soil,pile and pile-to-pile interactions. Comparisons with data available in literature are made to study the convergence and validate the model. An application to a realistic pile foundation is given to demonstrate the potential of the model to catch the dynamic behaviour of the soil,foundation system and the stress resultants in each pile. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Prognostic Value of 12-Lead Electrocardiogram During Dobutamine Stress Echocardiography

    ECHOCARDIOGRAPHY, Issue 5 2000
    Milind R. Dhond M.D.
    The aim of this study was to assess the prognostic value of the 12-lead electrocardiogram (ECG) obtained during dobutamine stress echocardiography (DSE) in predicting subsequent cardiac events. We retrospectively analyzed 345 patients undergoing DSE in 1992,1994 and selected those patients with negative echo results for ischemia. Of the 200 patients with negative DSE results, a separate analysis of their ECG data was performed with results reported as either positive, negative, or nondiagnostic for ischemia. Follow-up was performed through a physician chart review and direct telephone contact. Event rates were determined for hard (myocardial infarction or cardiac death) and soft (hospitalization for angina and/or congestive heart failure, coronary angioplasty, or coronary artery bypass graft surgery) cardiac events occurring after the negative DSE for up to 6 years after the test. Death was also determined by referencing the patients' data with mortality data available on the Internet. There were 143 patients with ECG data reported as negative and 40 patients with ECG data reported as positive for ischemia. The hard and soft event rates were 1.5% and 9% per patient per year in the ECG negative group and 2% and 11% in the ECG positive group. There were no statistical differences in event rates between the two groups during the 5-year follow-up period. Our results suggest that the ECG result obtained during DSE does not confer any incremental prognostic value over the echo result. [source]

    A practical protocol to assess impacts of unplanned disturbance: a case study in Tuggerah Lakes Estuary, NSW

    A. J. Underwood
    Summary Environmental managers are often confronted with unplanned or accidental disturbances that may lead to environmental impacts. Procedures for detecting or measuring the size of such impacts are complicated because of the lack of data available before the disturbance and because of the intrinsic variability of most natural measures. Here, a protocol for detecting impacts is illustrated for single-measure variables (numbers of individual species) and multivariate measures (relative abundances of invertebrates in assemblages). The present paper describes a case concerning drainage of acidified water into an estuary due to construction of a drainage channel in an area of wetland for which there had been no prior investigations (i.e. no ,before' data). The spatial extent of any impact was also unknowable. Sampling was, therefore, designed to allow for impacts of only a few tens of metres (using control sites 50 m from the mouth of the channel) and impacts covering much larger areas (500 m and 1 km from the mouth of the channel). Invertebrates in the mud around the channel and in control sites were sampled in replicated cores and the amount of seagrass in each core was weighed. Average abundances of invertebrate animals and weights of seagrass were compared, as was variation among samples in potentially impacted and control sites (using univariate analyses of variance). Sets of species were compared using multivariate methods to test the hypothesis that there was an impact at one of the scales examined. In fact, there was no evidence for any sort of impact on the fauna or seagrasses; the disturbance was a short-term pulse without any obvious or sustained ecological response. One consequence of the study was that the local council was able to demonstrate no impact requiring remediation and no penalties were imposed for the unapproved construction of the channel. The implications of this type of study after an environmental disturbance are discussed. The present study identifies the need for clear definition of relevant hypotheses, coupled with rigorous planning of sampling and analyses, so that reliable answers are available to regulators and managers. [source]

    Trends in the state of nature and their implications for human well-being

    ECOLOGY LETTERS, Issue 11 2005
    Andrew Balmford
    Abstract Two major international initiatives , the Convention on Biological Diversity's target to reduce the rate of biodiversity loss by 2010, and the Millennium Ecosystem Assessment , raise the profile of ecological data on the changing state of nature and its implications for human well-being. This paper is intended to provide a broad overview of current knowledge of these issues. Information on changes in the status of species, size of populations, and extent and condition of habitats is patchy, with little data available for many of the taxa, regions and habitats of greatest importance to the delivery of ecosystem services. However, what we do know strongly suggests that, while exceptions exist, the changes currently underway are for the most part negative, anthropogenic in origin, ominously large and accelerating. The impacts of these changes on human society are idiosyncratic and patchily understood, but for the most part also appear to be negative and substantial. Forecasting future changes is limited by our poor understanding of the cascading impacts of change within communities, of threshold effects, of interactions between the drivers of change, and of linkages between the state of nature and human well-being. In assessing future science needs, we not only see a strong role for ecological data and theory, but also believe that much closer collaboration with social and earth system scientists is essential if ecology is to have a strong bearing on policy makers. [source]

    Detection of carbonyl-modified proteins in interfibrillar rat mitochondria using N, -aminooxymethylcarbonylhydrazino- D -biotin as an aldehyde/keto-reactive probe in combination with Western blot analysis and tandem mass spectrometry

    ELECTROPHORESIS, Issue 6 2008
    Woon-Gye Chung
    Abstract There is now a large body of supporting data available that links oxidative modifications of proteins to a large number of diseases, degenerative disorders and aging. However, the detailed analysis of oxidative protein modifications remains challenging. Here, we report a new efficient method for identification of oxidatively modified proteins in complex biological samples which is based on the use of an aldehyde-reactive probe, N,-aminooxymethylcarbonylhydrazino- D -biotin (ARP), in combination with Western-type analyses and MS. The biotinylated hydroxylamine derivative forms a chemically stable oxime derivative with the aldehyde/keto group found in carbonyl-modified proteins. The biotin tag is detected by avidin affinity staining. ARP-positive proteins are subsequently subjected to in-gel trypsinization and MS/MS for protein identification. We demonstrate the usefulness of the method for the analysis of protein extracts obtained from interfibrillar heart mitochondria (IFM) from young and old rats. In this study, we identified as putative major protein targets of oxidative modifications the mitochondrial matrix protein, aconitase, the inner mitochondrial membrane protein, ADP/ATP translocase, and constituents of the electron transport chain complexes IV and V. An age-related increase of carbonyl levels was found for aconitase and ATP synthase. [source]

    Bradykinin stimulates prostaglandin E2 production and cyclooxygenase activity in equine nonglandular and glandular gastric mucosa in vitro

    Summary Reasons for performing study: There are few data available regarding regulation of prostaglandin (PG) generation by equine gastric mucosae and the role of the cyclooxygenase (COX) isoforms in their production. Objectives: To: 1) characterise and quantify PGE2 output in vitro; 2) examine the sensitivity of PGE2 production to exogenous bradykinin (BK) exposure; 3) determine the contribution of the COX-1 and COX-2 pathways to basal and BK-stimulated PGE2 production; and 4) measure if BK influences electrogenic ion transport in equine gastric mucosae in vitro. Methods: Full thickness gastric sheets were obtained from horses at post mortem, stripped of muscle layers and mounted in Ussing chambers. Tissues were exposed to bradykinin (BK, 0.1 ,mol/l) either alone, or following pretreatment with a selective COX-2 inhibitor (NS-398, 1 ,mol/l) or a nonselective COX inhibitor (piroxicam, 1 ,mol/l), or were untreated. Results: BK administration increased PGE2 output from the basolateral but not the apical faces of both tissue types. Piroxicam, but not NS-398, reduced basolateral PGE2 release below control levels in both tissue types. Both piroxicam and NS-398 pretreatment inhibited BK-stimulated PGE2 release. In separate experiments, BK was without effect upon electrophysiological parameters of tissues mounted in Ussing chambers. Conclusions: PGE2 is produced by the nonglandular and glandular equine gastric mucosae in vitro. Significantly more PGE2 is released basolaterally than apically. BK stimulated the production of PGE2 from the basolateral side of both tissue types. These findings suggest that COX-1 is a significant pathway for basal PGE2 production from the basolateral faces of both nonglandular and glandular equine gastric mucosae in vitro. Potential relevance: The identification of the cells responsible for basolateral PGE2 release, via both COX-1 and COX-2 pathways, under basal and BK-stimulated conditions requires further study. [source]

    An echocardiographic and auscultation study of right heart responses to training in young National Hunt Thoroughbred horses

    Summary Reasons for performing study: There are few data available to determine the effect of training on cardiac valve function. Objectives: To investigate the effect of commercial race training on right ventricular (RV) and tricuspid valve function in an untrained group of National Hunt Thoroughbreds (TB). Material and methods: Cardiac auscultation, guided M-mode echocardiography of the RV, and colour flow Doppler (CFD) tricuspid valve and right atrium were performed in 90 TB horses (age 2,7 years) 1998,2003. Forty horses were examined at least once and 48 horses were examined on at least 2 occasions. Examinations were then classified as: i) before commencement of race training, ii) after cantering exercise had been sustained for a period of 8,12 weeks and iii) at full race fitness. Tricuspid valve regurgitation (TR) murmurs were graded on a 1,6 scale and CFD echocardiography TR signals were graded on a 1,9 scale. Right ventricular internal diameter (RVID) in diastole and systole (RVIDd and RVIDs) was measured by guided M-mode. Associations between continuous RVID and TR measures and explanatory covariates of weight, age, heart rate, yard and stage of training were examined using general linear mixed models with horse-level random effects. Results: On average, RVIDd and RVIDs increased by 0.08 and 0.1 cm, respectively, per year increase in age (P=0.1 and 0.02) and by 0.3 and 0.4 cm, respectively between pre-training and race fitness (P = 0.07 and 0.005). Tricuspid regurgitation score by colour flow Doppler increased by 0.6/year with age (P<0.0001) and by 1.8 between pre-training and race fitness (P< 0.0001). No significant associations were found between any outcomes and weight, heart rate and training yard. Due to the high level of co-linearity between age and training, multivariable models including both terms were not interpretable. Conclusions and clinical relevance: Athletic training of horses exerts independent effects on both severity and prevalence of tricuspid valve incompetence. This effect should therefore be taken into account when examinations are performed. Dimensions of RV increase with age and training in TB horses in a manner that appears to be similar to that of the LV. [source]

    Concentration of methylprednisolone in the centrodistal joint after administration of methylprednisolone acetate in the tarsometatarsal joint

    Summary Reasons for performing study: The centrodistal (CD) and tarsometatarsal (TMT) joints are often injected individually with a corticosteroid to resolve lameness caused by osteoarthritis (OA). There are no data available regarding diffusion of methylprednisolone (MP) from the TMT joint to the CD joint. Hypothesis: A therapeutic concentration of MP diffuses into the CD joint after methylprednisolone acetate (MPA) is administered into the TMT joint. Objective: To measure the concentration of MP in the CD joint after MPA was administered into the TMT joint. Methods: MPA was administered into a TMT joint of 16 horses. At different times, the ipsilateral CD joint of these horses was injected with a small amount of saline and recovered saline was measured for concentration of MP using high performance liquid chromatography. Results: Six hours after administration of MPA into the TMT joint, a therapeutic concentration of MP was found in all 10 CD joints sampled at this time. Conclusions: Horses with pain arising from the distal 2 joints of the hock can be treated by administering MPA into the TMT joint alone. Potential relevance: Administering MPA into the TMT joint only, to treat OA of the distal 2 hock joints, reduces the difficulties and risks associated with centesis of the CD joint. [source]

    Cooperative Breeding and Group Structure in the Lake Tanganyika Cichlid Neolamprologus savoryi

    ETHOLOGY, Issue 11 2005
    Dik Heg
    As yet, cooperative breeding has been described only for some fish species. However, evidence is accumulating that it is widespread among Lake Tanganyika cichlids. We studied the cooperative breeding system of the substrate breeding cichlid Neolamprologus savoryi. Breeding groups typically consisted of a large breeding male with one to four breeding females and three to 33 helpers (mean group size: 14.3 members). Group size was significantly related to breeding male and female body sizes, and larger males had more breeding females and larger sized male helpers. The size of the largest female in the group was positively related to the number and sizes of secondary breeding females and female helpers. In case of multiple breeding females, these females usually divided the group's territory into sub-territories, each with its own helpers (subgroups). Interspersed between groups, independent fish were detected defending an individual shelter (4.4% of all fish). In 9% of the groups no breeding female was present. All group members participated in territory defence and maintenance, and showed submissive behaviours to larger group members. As expected, the level of between-subgroup conflicts was high compared with the level of within-subgroup conflicts. We compare these results with data available from other cooperatively breeding fishes. [source]