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Terms modified by Correlated Selected AbstractsPrescribing Flood Regimes to Sustain Riparian Ecosystems along Meandering RiversCONSERVATION BIOLOGY, Issue 5 2000Brian D. Richter By managing river flows for water supplies and power generation, water management agencies have inadvertently caused considerable degradation of riverine ecosystems and associated biodiversity. New approaches for meeting human needs for water while conserving the ecological integrity of riverine ecosystems are greatly needed. We describe an approach for identifying the natural flooding characteristics that must be protected or restored to maintain riparian ( floodplain) ecosystems along meandering rivers. We developed a computer model to simulate flood-driven changes in the relative abundance of riparian patch types along the Yampa River in Colorado ( U.S.A.). The model is based on research suggesting that the duration of flooding at or above 209 m3 per second (125% of bankfull discharge) is particularly important in driving lateral channel migration, which is responsible for initiating ecological succession in the Yampa's riparian forest. Other hydrologic variables, such as the magnitude of annual peak flows, were not as strongly correlated with lateral channel migration rates. Model simulations enabled us to tentatively identify a threshold of alteration of flood duration that could lead to substantial changes in the abundance of forest patch types over time should river flows be regulated by future water projects. Based on this analysis, we suggest an ecologically compatible water management approach that avoids crossing flood alteration thresholds and provides opportunity to use a portion of flood waters for human purposes. Recommended improvements to the Yampa model include obtaining additional low-elevation aerial photographs of the river corridor to enable better estimation of channel migration rates and vegetation changes. These additional data should greatly improve the model's accuracy and predictive capabilities and therefore its management value. Resumen: La composición y estructura de ecosistemas ribereños están fuertemente ligadas a la variabilidad hidrológica natural. Al manejar el flujo de ríos para abastecer agua y generar energía, las agencias de manejo de agua han causado inadvertidamente una degradación considerable de los ecosistemas ribereños y la biodiversidad asociada a ellos. Se necesitan nuevas estrategias para satisfacer las necesidades humanas de agua al mismo tiempo que se conserva la integridad de los ecosistemas ribereños. Describimos una estrategia para identificar las características de inundaciones naturales que deben ser protegidas o restauradas para mantener ecosistemas riparios ( planicies de inundación) a lo largo de ríos sinuosos. Desarrollamos un modelo de computadora para simular los cambios causados por inundaciones en la abundancia relativa de tipos de parche ripario a lo largo del río Yampa, en Colorado ( Estados Unidos de Norteamérica). Este modelo se basa en investigación que sugiere que la duración de la inundación a, o mayor a, 209 m3 por segundo (125% de descarga del banco lleno a su capacidad) es particularmente importante en la conducción de la migración de canales laterales, lo cual es responsable de la iniciación de la sucesión ecológica en el bosque ripario del río Yampa. Otras variables hidrológicas, como lo es la magnitud del pico de los flujos anuales no estuvieron tan fuertemente correlacionadas con las tasas de migración lateral de canales. Las simulaciones del modelo nos permitieron identificar límites tentativos de alteración de la duración de la inundación que podrían conducir a cambios sustanciales en la abundancia de tipos de parches forestales en el tiempo si los flujos de los ríos son regulados en proyectos de agua futuros. En base a este análisis, sugerimos una estrategia de manejo de agua ecológicamente compatible que evita sobrepasar los límites de alteración de las inundaciones y provee la oportunidad de usar una porción del agua de las inundaciones para fines humanos. Las recomendaciones de mejoras al modelo del río Yampa incluyen la necesidad de obtener fotografías aéreas de baja elevación adicionales del corredor del río, que permitan una mejor estimación de las tasas de migración de los canales y los cambios en la vegetación. Estos datos adicionales deberán mejorar en gran medida la precisión del modelo y sus capacidades predictivas y, por lo tanto, su valor de manejo. [source] Human immunodeficiency virus gag and pol-specific CD8 T cells in perinatal HIV infectionCYTOMETRY, Issue 5 2001Thomas W. McCloskey Abstract Background: Binding of fluorochrome-conjugated MHC class I tetramers is a powerful means to detect antigen-specific CD8 T lymphocytes. In human immunodeficiency virus (HIV) infection, cellular immune response is essential in curtailing HIV disease progression but gaps persist in our understanding of HIV-specific cells during the disease course. In this study, we evaluated tetramer binding HIV-specific CD8 T cells in HIV-infected children. Methods: Fluorescently labeled tetramers for HIV gag and pol were utilized to quantify antigen-specific cells by flow cytometry using a whole blood labeling method in a cohort of 19 HLA-A2+ HIV- infected children (age range 1 month to 17 years). Results: Fourteen children had detectable gag (median 0.4%) and pol (median 0.1%) binding CD8 T cells, three children had gag binding cells only, and two had neither. Numbers of gag and pol binding cells correlated with each other and each correlated independently with total CD8 T cells and total CD4 T cells. Conclusions: HIV gag and pol-specific CD8 T cells are maintained during the chronic phase of HIV infection in children and CD4 lymphocytes appear to be important for sustaining their levels. Cytometry (Comm. Clin. Cytometry) 46:265,270, 2001. © 2001 Wiley-Liss, Inc. [source] Novel application of flow cytometry: Determination of muscle fiber types and protein levels in whole murine skeletal muscles and heartCYTOSKELETON, Issue 12 2007Connie Jackaman Abstract Conventional methods for measuring proteins within muscle samples such as immunohistochemistry and western blot analysis can be time consuming, labor intensive and subject to sampling errors. We have developed flow cytometry techniques to detect proteins in whole murine heart and skeletal muscle. Flow cytometry and immunohistochemistry were performed on quadriceps and soleus muscles from male C57BL/6J, BALB/c, CBA and mdx mice. Proteins including actins, myosins, tropomyosin and ,-actinin were detected via single staining flow cytometric analysis. This correlated with immunohistochemistry using the same antibodies. Muscle fiber types could be determined by dual labeled flow cytometry for skeletal muscle actin and different myosins. This showed similar results to immunohistochemistry for I, IIA and IIB myosins. Flow cytometry of heart samples from C57BL/6J and BALB/c mice dual labeled with cardiac and skeletal muscle actin antibodies demonstrated the known increase in skeletal actin protein in BALB/c hearts. The membrane-associated proteins ,-sarcoglycan and dystrophin could be detected in C57BL/6J mice, but were decreased or absent in mdx mice. With the ability to label whole muscle samples simultaneously with multiple antibodies, flow cytometry may have advantages over conventional methods for certain applications, including assessing the efficacy of potential therapies for muscle diseases. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source] Freshwater invasions: using historical data to analyse spreadDIVERSITY AND DISTRIBUTIONS, Issue 1 2007Sarina E. Loo ABSTRACT Aquatic invasive species cause deleterious environmental and economic impacts, and are rapidly spreading through ecosystems worldwide. Despite this, very few data sets exist that describe both the presence and the absence of invaders over long time periods. We have used Geographical Information Systems (GIS) to analyse time-series data describing the spread of the freshwater invasive New Zealand mudsnail, Potamopyrgus antipodarum, in Victoria, Australia, over 110 years. We have mapped the snail's spread, estimated the percentage of stream length invaded through time, calculated the functional form of the spread rate, and investigated the role that the two proposed vectors , fish stocking and angling , have had in this invasion. Since it was first found in 1895, P. antipodarum has expanded its range in Victoria and now occurs throughout much of the southern and central areas of the state. The north of the state is relatively less invaded than the south, with the division corresponding approximately to the presence of the Great Dividing Range. We show that the snail's range has been increasing at an approximately exponential rate and estimate that 20% of total Victorian stream length is currently invaded. We also show that using long-term data can change the outcome of analyses of the relationship between vectors of spread and invasion status of separate catchments. When our time-series data were aggregated through time, the total numbers of fish stocking events and angling activity were both correlated with invasion. However, when the time-series data were used and the number of fish stocking events calculated up until the date of invasion, no relationships with stocking were found. These results underline the role that time-series data, based on both presences and absences, have to play when investigating the spread of invasive species. [source] Beta diversity of geometrid moths (Lepidoptera: Geometridae) in an Andean montane rainforestDIVERSITY AND DISTRIBUTIONS, Issue 5 2003Gunnar Brehm Abstract. Turnover in species composition of the extremely species-rich family Geometridae (Lepidoptera) was investigated along an elevational gradient ranging from 1040 m to 2677 m above sea level. Moths were sampled using weak light traps (30 W) in three field periods in 1999 and 2000 in an Andean montane rainforest in the province of Zamora-Chinchipe in southern Ecuador. A total of 13 938 specimens representing 1010 species were analysed. Similarities of ensembles of all geometrid moths and of the subfamilies Ennominae and Larentiinae were calculated using the NESS index (with mmax). Ordinations performed using nonmetric multidimensional scaling (NMDS) and correspondence analysis depicted a gradual change of the ensembles along the altitudinal gradient. Extracted ordination scores significantly correlate with altitude (,0.97 , r , ,0.95, P < 0.001) and with ambient air temperature (0.93 , r , 0.97, P < 0.001). Temperature is therefore assumed to be the most important abiotic determinant responsible for the species turnover among the moths. Matrix correlation tests were performed in order to compare faunal matrices with matrices derived from available environmental factors. Both tree diversity and vegetation structure significantly correlate with faunal data, but tree diversity explains considerably more of the data variability (range: Mantel r = 0.81,0.83, P < 0.001) than vegetation structure (range: Mantel r = 0.35, P < 0.005 to r = 0.43, P < 0.001). Tree diversity also changes gradually and scores of the first NMDS dimension are highly significantly correlated with altitude (r = 0.98, P < 0.001). A common underlying factor such as ambient temperature might also be responsible for such vegetation changes. Additionally, simulated model data was developed that assumed a constant turnover of moth species and equal elevational ranges of all species involved. Despite the simplicity of the models, they fit empirical data very well (Mantel r > 0.80 and P < 0.001 in all models). [source] A Novel Approach to Assess Aortic Stiffness Related to Changes in Aging Using a Two-Dimensional Strain ImagingECHOCARDIOGRAPHY, Issue 9 2008Yoshifumi Oishi M.D. Background: Recently, it has been demonstrated that aortic stiffness is associated with cardiovascular morbidity and mortality. The objective of the present study was to accurately evaluate the aortic stiffness relative to the changes in aging using two-dimensional (2D) strain imaging in 39 comparatively normal patients (15,85 years). Methods: We obtained short-axis images of the abdominal aorta (Ao) and determined the peak circumferential strain (Ao-S) and strain rate (Ao-SR) and the time from Q-wave of electrocardiogram to peak Ao-S using the 2D strain imaging. The stiffness parameters ,1 and ,2 of the abdominal aorta were measured using M-mode ultrasonography and 2D strain imaging, respectively. Results: The stiffness parameters ,1 and ,2 correlated significantly with age (r=0.51, P < 0.001 and r=0.69, P < 0.0001, respectively), particularly the latter parameter ,2. The peak circumferential Ao-S and Ao-SR correlated strongly with age (r=,0.79, P < 0.0001 and r=,0.87, P < 0.0001, respectively). The stiffness parameter ,1 was significantly greater in the old-aged group (>60 years) than in the young-aged group (<30 years). The peak circumferential Ao-S and Ao-SR were significantly lower in the middle-aged (30,60 years) and old-aged groups than in the young-aged group. Conclusion: The aortic circumferential strain and strain rate measured by 2D strain imaging allow simple and accurate determination of the aortic stiffness. [source] Dynamics in a butterfly,plant,ant system: influence of habitat characteristics on turnover rates of the endangered lycaenid Maculinea alconECOLOGICAL ENTOMOLOGY, Issue 5 2007JAN CHRISTIAN HABEL Abstract 1.,Maculinea alcon, a myrmecophilic, stenotopic lycaenid butterfly is restricted to wet heathlands, bogs, and nutrient-poor hay meadows. Due to intensification of agriculture and decrease of extensively grazed meadows, many suitable habitats have disappeared and the remaining ones are highly fragmented and deteriorated. 2.,Historical distribution data and a comparison with the present occupation of patches show the decline of this critically endangered butterfly in north-west Germany. Most of the populations in north-west Germany are small and often geographically isolated. 3.,In summer 2002, two-thirds of 77 investigated potential patches were unoccupied as a result of unsuitable habitat structure and habitat fragmentation. 4.,Several habitat parameters were highly significantly correlated with the presence of M. alcon, in particular the distribution pattern of the host plant Gentiana pneumonanthe. Furthermore, butterflies were absent from many patches with an incidence probability below 50% with respect to patch size and isolation. 5.,In the nature reserve Lüneburger Heide, part of the study area, M. alcon populations have been observed since 1995. Typical turnover of local populations could be detected during these years. Extinctions and re-colonisations have stabilised the presence of this species in a metapopulation in this nature reserve. 6.,These data show the importance of different factors on different spatial levels influencing the presence of this endangered butterfly. [source] Tospoviruses infecting vegetable crops in IsraelEPPO BULLETIN, Issue 2 2000A. Gera Symptoms of vein clearing, stem necrosis, curling, necrotic spots and rings on the leaves associated with infection by tomato spotted wilt tospovirus (TSWV) were documented among vegetable crops growing in commercial glasshouses and open fields in Israel. Plants exhibiting symptoms were collected, from 1994-01 to 1998-12. Among cultivated vegetable crops analysed for TSWV by ELISA, the following plants were found to be infected: tomato, capsicum, aubergine, lettuce, cabbage and cucumber. These incidences of the virus were all correlated with the occurrence in high population of Frankliniella occidentalis. Transmission of the virus from infected Datura stramonium to Petunia leaf discs, by F. occidentalis, was up to 26%. TSWV antigens were readily detected by ELISA in seeds harvested from naturally infected vegetable crops. However, we failed to show virus transmission to the progeny plants. Iris yellow spot tospovirus (IYSV) was detected in onion. High incidence of the disease was associated with large populations of Thrips tabaci. [source] MSK regulate TCR-induced CREB phosphorylation but not immediate early gene transcriptionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2007Madlen Kaiser Abstract Stimulation of the T cell receptor activates the ERK1/2 and p38 mitogen-activated protein kinase (MAPK) cascades. We demonstrate that TCR stimulation also activates the mitogen- and stress-activated kinases (MSK) downstream of ERK1/2 and p38 in both a T cell line and primary peripheral T cells. MSK1/2-knockout mice were found to have normal numbers of T cells in the thymus, and development of these cells appeared unaffected. Using naive T cells and T lymphoblasts from MSK1/2-knockout mice, it was found that MSK was the kinase responsible for phosphorylation of the transcription factor CREB in response to TCR stimulation. Phosphorylation of CREB by MSK has been linked to the transcription of nur77, nor1 and c-fos downstream of MAPK signalling in various cell types. In T cells, the TCR-dependent transcription of these genes was found to require a MAPK-dependent but MSK-independent signalling pathway. Nevertheless, the number of T cells present in the spleens of MSK1/2-knockout mice and the IL-2-induced proliferation of these cells was reduced compared to wild-type mice. This correlated to a reduction in the TCR-induced up-regulation of the IL-2 receptor CD25 and a requirement for MSK in IL-2-induced CREB phosphorylation. [source] Inverse correlation between IL-7 receptor expression and CD8 T cell exhaustion during persistent antigen stimulationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2005Abstract Persistence is a hallmark of infection by viruses such as HIV, hepatitis B virus, hepatitis C virus and LCMV. In the case of LCMV, persistence may often be associated with exhaustion of CD8+ T cells. We demonstrate here that persistent antigen suppressed IL-7R, expression and this correlated with T cell exhaustion and reduced expression of the anti-apoptotic molecule B cell leukemia/lymphoma 2 (Bcl-2). In contrast, exposure to short-lived antigen only temporarily suppressed IL-7R, expression, failed to induce T cell exhaustion, and primed T cells. Persistent antigen also suppressed IL-7R, expression on primed T cells and this correlated with exhaustion of a previously stable primed T cell population. These findings suggest that antigen longevity regulates T cell fate. [source] Effect of neurotrophin-3 on reinnervation of the larynx using the phrenic nerve transfer techniqueEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2007Paul J. Kingham Abstract Current techniques for reinnervation of the larynx following recurrent laryngeal nerve (RLN) injury are limited by synkinesis, which prevents functional recovery. Treatment with neurotrophins (NT) may enhance nerve regeneration and encourage more accurate reinnervation. This study presents the results of using the phrenic nerve transfer method, combined with NT-3 treatment, to selectively reinnervate the posterior cricoarytenoid (PCA) abductor muscle in a pig nerve injury model. RLN transection altered the phenotype and morphology of laryngeal muscles. In both the PCA and thyroarytenoid (TA) adductor muscle, fast type myosin heavy chain (MyHC) protein was decreased while slow type MyHC was increased. These changes were accompanied with a significant reduction in muscle fibre diameter. Following nerve repair there was a progressive normalization of MyHC phenotype and increased muscle fibre diameter in the PCA but not the TA muscle. This correlated with enhanced abductor function indicating the phrenic nerve accurately reinnervated the PCA muscle. Treatment with NT-3 significantly enhanced phrenic nerve regeneration but led to only a small increase in the number of reinnervated PCA muscle fibres and minimal effect on abductor muscle phenotype and morphology. Therefore, work exploring other growth factors, either alone or in combination with NT-3, is required. [source] REPLICATED EVOLUTION OF INTEGRATED PLASTIC RESPONSES DURING EARLY ADAPTIVE DIVERGENCEEVOLUTION, Issue 4 2006Kevin J. Parsons Abstract Colonization of a novel environment is expected to result in adaptive divergence from the ancestral population when selection favors a new phenotypic optimum. Local adaptation in the new environment occurs through the accumulation and integration of character states that positively affect fitness. The role played by plastic traits in adaptation to a novel environment has generally been ignored, except for variable environments. We propose that if conditions in a relatively stable but novel environment induce phenotypically plastic responses in many traits, and if genetic variation exists in the form of those responses, then selection may initially favor the accumulation and integration of functionally useful plastic responses. Early divergence between ancestral and colonist forms will then occur with respect to their plastic responses across the gradient bounded by ancestral and novel environmental conditions. To test this, we compared the magnitude, integration, and pattern of plastic character responses in external body form induced by shallow versus open water conditions between two sunfish ecomorphs that coexist in four postglacial lakes. The novel sunfish ecomorph is present in the deeper open water habitat, whereas the ancestral ecomorph inhabits the shallow waters along the lake margin. Plastic responses by open water ecomorphs were more correlated than those of their local shallow water ecomorph in two of the populations, whereas equal levels of correlated plastic character responses occurred between ecomorphs in the other two populations. Small but persistent differences occurred between ecomorph pairs in the pattern of their character responses, suggesting a recent divergence. Open water ecomorphs shared some similarities in the covariance among plastic responses to rearing environment. Replication in the form of correlated plastic responses among populations of open water ecomorphs suggests that plastic character states may evolve under selection. Variation between ecomorphs and among lake populations in the covariance of plastic responses suggests the presence of genetic variation in plastic character responses. In three populations, open water ecomorphs also exhibited larger plastic responses to the environmental gradient than the local shallow water ecomorph. This could account for the greater integration of plastic responses in open water ecomorphs in two of the populations. This suggests that the plastic responses of local sunfish ecomorphs can diverge through changes in the magnitude and coordination of plastic responses. Although these results require further investigation, they suggest that early adaptive evolution in a novel environment can include changes to plastic character states. The genetic assimilation of coordinated plastic responses could result in the further, and possibly rapid, divergence of such populations and could also account for the evolution of genes of major effect that contribute to suites of phenotypic differences between divergent populations. [source] Early Distal-less expression in a developing crustacean limb bud becomes restricted to setal-forming cellsEVOLUTION AND DEVELOPMENT, Issue 1 2008Terri A. Williams SUMMARY Distal-less (Dll) plays a well-known role in patterning the distal limb in arthropods. However, in some taxa, its expression even during early limb development is not always limited to the distal limb. Here, I trace the expression of Distal-less in a crustacean (Thamnocephalus platyurus) from the early limb bud to later stages of limb development, a period that includes differentiation of juvenile and adult morphology. During early development, I find two distinct types of DLL expression: one correlated with proximal distal leg patterning and the other restricted to setal-forming cells. Later in development, all the DLL expression is restricted to setal-forming cells. Based on the particular cells expressing DLL, I hypothesize an ancestral role for Dll function in the formation accessory cells of sensilla. [source] The skin as a biofactory for systemic secretion of erythropoietin: potential of genetically modified keratinocytes and fibroblastsEXPERIMENTAL DERMATOLOGY, Issue 6 2008Frank Scheidemann Abstract Background:, The skin is an interesting target tissue for gene therapy applications because of its ready accessibility. One possibility would be to utilize the genetically modified skin as a biofactory secreting a systemically needed product, such as erythropoietin (EPO). Methods:, Keratinocytes (KC) and fibroblasts (FB) were transduced with a retroviral vector encoding human EPO. Gene transfer efficiency was assessed by real-time PCR analysis and flow cytometry of transduced cells. In addition, EPO synthesis and secretion were analysed by quantifying the amount of RNA and secreted protein in both monolayer cultures and skin equivalents (SE). Results:, When cultured as a monolayer, EPO-KC synthesized significantly more EPO than EPO-FB, as shown by quantitatively measuring the amount of secreted protein and RNA. This correlated with an increased EPO-vector incorporation in KC compared with FB, demonstrated by determining both the percentage of transduced cells and the average transgene copy number per cell. In addition, in transduced cell cultures enriched to equally high percentages of EPO+ cells, KC showed a higher activity of EPO secretion than FB. Finally, when assembled in a SE, EPO-KC secreted significantly higher amounts of EPO than EPO-FB, although reduced secretory activity of EPO-KC monolayers grown in high calcium concentrations suggested that in stratified epidermis differentiated KC secrete less EPO than non-differentiated KC. Conclusion:, In summary, while both transduced KC and FB are able to synthesize and secrete human EPO, KC show higher potential in serving as possible target cells for therapeutic substitution with EPO, probably because of improved transduction rates and increased secretory activity. [source] Seasonal and management influences on bacterial community structure in an upland grassland soilFEMS MICROBIOLOGY ECOLOGY, Issue 3 2005Nabla M. Kennedy Abstract Floristically diverse Nardo,Galion upland grasslands are common in Ireland and the UK and are valuable in agricultural, environmental and ecological terms. Under improvement (inputs of lime, fertiliser and re-seeding), they convert to mesotrophic grassland containing very few plant species. The effects of upland grassland improvement and seasonality on soil microbial communities were investigated at an upland site. Samples were taken at five times in one year in order to observe seasonal trends, and bacterial community structure was monitored using automated ribosomal intergenic spacer analysis (ARISA), a DNA-fingerprinting approach. Differences in soil chemistry and bacterial community structure between unimproved and improved grassland soils were noted. Season was also found to cause mild fluctuations in bacterial community structure, with soil samples from colder months (October and December) more correlated with change in ribotype profiles than samples from warmer months. However, for the majority of seasons clear differences in bacterial community structures from unimproved and improved soils could be seen, indicating seasonal influences did not obscure effects associated with improvement. [source] Changes in fish assemblages in catchments in north-eastern Spain: biodiversity, conservation status and introduced speciesFRESHWATER BIOLOGY, Issue 8 2010ALBERTO MACEDA-VEIGA Summary 1. North-eastern Spain is a hot spot for the introduction of alien fish species, and its native fish fauna is one of the most endangered worldwide. We used an extensive data set from 2002 to 2003 and historical information from the area to characterize fish diversity and establish conservation priorities in river catchments. 2. Diversity indices were used to characterize fish diversity at the basin scale. An index of conservation status was applied for each species, which considers the occurrence, abundance and endemicity of each taxon. We used indirect ordination methods to test the relationship among basin features and to identify those variables most correlated with each other. To identify physical, biotic and environmental characteristics that seem to make a basin particularly susceptible to invasion, we performed a step-wise multiple regression to examine the relationship between the number of native, translocated and introduced fish species (including the original native species richness of each basin), and landscape variables. 3. Over a period of approximately 50 years, the mean range size of native fish species has decreased by 60%. The greatest decline occurred in Gasterosteus gymnurus, Anguilla anguilla and Salaria fluviatilis, for which species over 75% of the original distribution area has been lost. The species with the highest conservation index were Gasterosteus gymnurus and Salaria fluviatilis. 4. Basin area and the catchment type explained 70% of variation in native species richness, whereas the number of dams and basin area accounted for more than 80% of variation in the number of introduced species. 5. The original native species richness and the number of introduced species at basin scale were not related, and thus there was no evidence of "biotic resistance" to invasion. The restoration of natural hydrologic processes and the development of specific management tools to protect native species, such as the prioritization of areas for fish conservation and the eradication of local populations of exotic species, are required to restore native fish fauna in these catchments. [source] Leaf dark respiration as a function of canopy position in Nothofagus fusca trees grown at ambient and elevated CO2 partial pressures for 5 yearsFUNCTIONAL ECOLOGY, Issue 4 2001K. L. Griffin Summary 1,Mass-based and area-based rates of respiration, leaf nitrogen content, leaf total protein content, non-structural carbohydrates and leaf mass per unit area (LMA) all decreased with depth in the canopy of Nothofagus fusca (Hook. F.) Oerst. (Red beech) trees grown for 5 years at ambient (36 Pa) or elevated (66 Pa) CO2 partial pressures. 2Elevated CO2 partial pressure had a strong effect on dark respiration, decreasing both mass-based and area-based rates at all canopy positions, but had little or no effect on leaf physical and biochemical properties. 3Leaf sugars, starch, protein, N and LMA were all correlated with respiration rate, and are therefore strong predictors of area-based dark respiration rates. The y axis intercept of regressions of respiration rate on mean leaf N, protein, starch and LMA was lower for plants grown at elevated compared to ambient CO2 partial pressures because of the differential effect of growth at elevated CO2 partial pressure on leaf gas-exchange, chemical and physical characteristics. 4,The lower respiration rates for leaves from trees grown at elevated CO2 partial pressure resulted in a significant increase in the ratio of light-saturated net photosynthesis to respiration, increasing the potential carbon-use efficiency of these leaves. [source] Evaluating interactions between soil drainage and seedling performance in a restoration of Pinus sylvestris woodland, ScotlandGLOBAL ECOLOGY, Issue 2 2001M. D. Crowell Abstract 1,This paper evaluates the role of soil drainage in tree seedling performance at a site being restored from Calluna vulgaris moorland to Pinus sylvestris woodland, in Glen Affric, Scotland. The investigation focuses on the relationships between height of planted seedlings, type of ground vegetation and drainage conditions. 2,Slope, aspect, and soil depth were assessed as potential surrogates for direct measures of soil drainage, all of which were derived from digital terrain data. 3,Six variables related to drainage were recorded at 58 seedling locations and used in a factor analysis to understand links between soil moisture conditions, topographic variables and soil depth characteristics. 4,Factor analysis generated two factors that accounted for 70.5% of the variance in the correlation matrix of these variables: Factor 1 correlated strongly with variables that controlled peat accumulation and Factor 2 correlated strongly with topographic controls upon drainage patterns. 5,These two factors explained a significant amount of the variance in height of the Pinus seedlings planted at these locations. Significant differences were found between the factor scores associated with different types of ground vegetation, as well as between the seedling heights observed at locations with different vegetation types. 6,Multiple regressions were developed that indicated that slope, aspect, and soil depth were significant as independent variables in models where soil moisture content and aerobic soil depth were the dependent variables. [source] Phytosociological study on steppe vegetation in the vicinity of Kharkiv, UkraineGRASSLAND SCIENCE, Issue 2 2006Yunxiang Cheng Abstract To classify the steppe vegetation of the natural grasslands in the Ukraine from a viewpoint of phytosociology, vegetation investigation was carried out in three relatively homogeneous sites in Kharkiv Province. Plant communities were classified by their characteristic species and differential species on the basis of the floristic composition into two communities, Stipa capillata,Festuca sulcata community and Poa angustifolia,F. sulcata community, and below four lower units. Using the data of three phases of soil in each of the three sites and the detrended correspondence analysis ordination technique, the score of axis 1 correlated most closely with geographical gradient which reflected the soil water condition. This result shows that the S. capillata,F. sulcata community is more tolerant to a dry habitat of the steppe vegetation of the Ukraine. [source] Should uptake of state benefits be used as indicators of need and disadvantage?HEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 4 2006Michael Rosato BSc MSc Abstract Government requires indicators of disadvantage to guide programmes and allocate resources to those areas which are most in need. Proxy measures of relative disadvantage are often utilised for this task in the absence of ideal indicators of need. The recent availability of government administrative datasets, such as social security benefit uptake levels, are increasingly being used throughout the UK and have been hailed as a significant advance on previous measures of need. However, their suitability presupposes that the association between those in need of benefit and those actually in receipt of benefit is not confounded by non-needs-related factors. In the present study, the authors examine area-level factors associated with uptake of one health-related benefit and show that, while closely correlated with health status, it is also associated with factors which might be related to the propensity and ability to make a successful claim, as well as local adjudication practices. They conclude that, while the use of these government datasets has increased our ability to target resources, researchers and policy makers should be aware of these additional influences. [source] Tumor necrosis factor,like weak inducer of apoptosis is a mitogen for liver progenitor cells,,HEPATOLOGY, Issue 1 2010Janina E. E. Tirnitz-Parker Liver progenitor cells (LPCs) represent the cell compartment facilitating hepatic regeneration during chronic injury while hepatocyte-mediated repair mechanisms are compromised. LPC proliferation is frequently observed in human chronic liver diseases such as hereditary hemochromatosis, fatty liver disease, and chronic hepatitis. In vivo studies have suggested that a tumor necrosis factor family member, tumor necrosis factor,like weak inducer of apoptosis (TWEAK), is promitotic for LPCs; whether it acts directly is not known. In our murine choline-deficient, ethionine-supplemented (CDE) model of chronic liver injury, TWEAK receptor [fibroblast growth factor-inducible 14 (Fn14)] expression in the whole liver is massively upregulated. We therefore set out to investigate whether TWEAK/Fn14 signaling promotes the regenerative response in CDE-induced chronic liver injury by mitotic stimulation of LPCs. Fn14 knockout (KO) mice showed significantly reduced LPC numbers and attenuated inflammation and cytokine production after 2 weeks of CDE feeding. The close association between LPC proliferation and activation of hepatic stellate cells in chronic liver injury prompted us to investigate whether fibrogenesis was also modulated in Fn14 KO animals. Collagen deposition and expression of key fibrogenesis mediators were reduced after 2 weeks of injury, and this correlated with LPC numbers. Furthermore, the injection of 2-week-CDE-treated wildtype animals with TWEAK led to increased proliferation of nonparenchymal pan cytokeratin,positive cells. Stimulation of an Fn14-positive LPC line with TWEAK led to nuclear factor kappa light chain enhancer of activated B cells (NF,B) activation and dose-dependent proliferation, which was diminished after targeting of the p50 NF,B subunit by RNA interference. Conclusion: TWEAK acts directly and stimulates LPC mitosis in an Fn14-dependent and NF,B-dependent fashion, and signaling via this pathway mediates the LPC response to CDE-induced injury and regeneration. (HEPATOLOGY 2010) [source] Induction of avian musculoaponeurotic fibrosarcoma proteins by toxic bile acid inhibits expression of glutathione synthetic enzymes and contributes to cholestatic liver injury in mice,HEPATOLOGY, Issue 4 2010Heping Yang We previously showed that hepatic expression of glutathione (GSH) synthetic enzymes and GSH levels fell 2 weeks after bile duct ligation (BDL) in mice. This correlated with a switch in nuclear anti-oxidant response element (ARE) binding activity from nuclear factor erythroid 2,related factor 2 (Nrf2) to c,avian musculoaponeurotic fibrosarcoma (c-Maf)/V-maf musculoaponeurotic fibrosarcoma oncogene homolog G (MafG). Our current aims were to examine whether the switch in ARE binding activity from Nrf2 to Mafs is responsible for decreased expression of GSH synthetic enzymes and the outcome of blocking this switch. Huh7 cells treated with lithocholic acid (LCA) exhibited a similar pattern of change in GSH synthetic enzyme expression as BDL mice. Nuclear protein levels of Nrf2 fell at 20 hours after LCA treatment, whereas c-Maf and MafG remained persistently induced. These changes translated to ARE nuclear binding activity. Knockdown of c-Maf or MafG individually blunted the LCA-induced decrease in Nrf2 ARE binding and increased ARE-dependent promoter activity, whereas combined knockdown was more effective. Knockdown of c-Maf or MafG individually increased the expression of GSH synthetic enzymes and raised GSH levels, and combined knockdown exerted an additive effect. Ursodeoxycholic acid (UDCA) or S-adenosylmethionine (SAMe) prevented the LCA-induced decrease in expression of GSH synthetic enzymes and promoter activity and prevented the increase in MafG and c-Maf levels. In vivo knockdown of the Maf genes protected against the decrease in GSH enzyme expression, GSH level, and liver injury after BDL. Conclusion: Toxic bile acid induces a switch from Nrf2 to c-Maf/MafG ARE nuclear binding, which leads to decreased expression of GSH synthetic enzymes and GSH levels and contributes to liver injury during BDL. UDCA and SAMe treatment targets this switch. (HEPATOLOGY 2010.) [source] Fractures and avascular necrosis before and after orthotopic liver transplantation: Long-term follow-up and predictive factors,HEPATOLOGY, Issue 4 2007Maureen M. J. Guichelaar With early posttransplant bone loss, orthotopic liver transplantation (OLT) recipients experience a high rate of fracturing and some avascular necrosis (AVN), but little is known about the incidence of and predictive factors for these skeletal complications. We studied 360 consecutive patients who underwent transplantation for primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) and assessed both vertebral and nonvertebral (rib, pelvic, and femur) fractures in a protocolized fashion. Before OLT, 20% of the patients had experienced fracturing, and 1.4% of the patients had experienced AVN. Following OLT, there was a sharp increase in fracturing, with a 30% cumulative incidence of fractures at 1 year and 46% at 8 years after transplantation. In contrast to previous studies, there was a similar incidence of posttransplant vertebral and nonvertebral fractures. The greatest risk factors for posttransplant fracturing were pretransplant fracturing and the severity of osteopenia and posttransplant glucocorticoids. Nine percent of the liver recipients experienced AVN after OLT, and this correlated with pretransplant and posttransplant lipid metabolism, bone disease (bone mineral density and fracturing), and posttransplant glucocorticoids. A novel association between cholestasis and AVN was also identified, the mechanism for which is not known. Conclusion: Fortunately, recent years have seen an increase in the bone mass of liver recipients and, along with this, less fracturing and less AVN. Nonetheless, 25% of patients undergoing OLT for chronic cholestatic liver disease still develop de novo fractures after OLT; this situation demands an ongoing search for effective therapeutic agents for these patients. (HEPATOLOGY 2007.) [source] Altered gene expression in acute systemic inflammation detected by complete coverage of the human liver transcriptomeHEPATOLOGY, Issue 2 2004Cédric Coulouarn The goal of the current study was to provide complete coverage of the liver transcriptome with human probes corresponding to every gene expressed in embryonic, adult, and/or cancerous liver. We developed dedicated tools, namely, the Liverpool nylon array of complementary DNA (cDNA) probes for approximately 10,000 nonredundant genes and the LiverTools database. Inflammation-induced transcriptome changes were studied in liver tissue samples from patients with an acute systemic inflammation and from control subjects. One hundred and fifty-four messenger RNAs (mRNA) correlated statistically with the extent of inflammation. Of these, 134 mRNA samples were not associated previously with an acute-phase (AP) response. The hepatocyte origin and proinflammatory cytokine responsiveness of these mRNAs were confirmed by quantitative reverse-transcription polymerase chain reaction (Q-RT-PCR) in cytokine-challenged hepatoma cells. The corresponding gene promoters were enriched in potential binding sites for inflammation-driven transcription factors in the liver. Some of the corresponding proteins may provide novel blood markers of clinical relevance. The mRNAs whose level is most correlated with the AP extent (P < .05) were enriched in intracellular signaling molecules, transcription factors, glycosylation enzymes, and up-regulated plasma proteins. In conclusion, the hepatocyte responded to the AP extent by fine tuning some mRNA levels, controlling most, if not all, intracellular events from early signaling to the final secretion of proteins involved in innate immunity. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (HEPATOLOGY 2004;39:353,364.) [source] Susceptibility to experimental biliary atresia linked to different hepatic gene expression profiles in two mouse strainsHEPATOLOGY RESEARCH, Issue 2 2010Johannes Leonhardt Aim:, To compare hepatic gene expression during the development of experimental biliary atresia (BA) in two different mouse strains. Methods:, Balb/c mice and C57Black/6 (Black/6) mice were infected with rhesus rotavirus (RRV) postpartum, clinical signs of BA and survival were noted. Liver sections were assessed for cluster of differentiation antigen (CD) 3, CD4 and CD8 expression, and the hepatic virus load was determined. Second, mice of both strains were sacrificed three days after infection. Isolated hepatic RNA was subjected to gene expression analysis using Affymetrix Gene Chip MOE 430 2.0. Results:, The incidence of BA was significantly lower in Black/6 mice compared to Balb/c mice (13.5% vs. 67%, P < 0.05). The mean virus titers were higher in mice with BA compared to mice without BA. Different gene profiles three days after virus infection were noted, with differential expression of 201 genes, including those regulating apoptosis, nucleic acid binding, transport function and particularly the immune response (chemokine C-C motif ligand 2, toll-like receptor 3, CD antigen 14, chemokine (C-X-C motif) ligands 10 and 11). This correlated with a significant increase of CD4 positive cells only in Balb/c mice with BA compared to healthy mice (13.5 vs. 5.0; P < 0.05). Black/6 mice did not exhibit any significant increase of CD3 or CD4 leukocytes despite cholestasis. Conclusion:, The different susceptibility to experimental BA was associated with an increase of CD4 T-cells in the liver of Balb/c mice, which is linked to different gene profiles at the onset of bile duct obstruction. [source] Emotional imagery: Assessing pleasure and arousal in the brain's reward circuitryHUMAN BRAIN MAPPING, Issue 9 2010Vincent D. Costa Abstract Research on emotional perception and learning indicates appetitive cues engage nucleus accumbens (NAc) and medial prefrontal cortex (mPFC), whereas amygdala activity is modulated by the emotional intensity of appetitive and aversive cues. This study sought to determine patterns of functional activation and connectivity among these regions during narrative emotional imagery. Using event-related fMRI, we investigate activation of these structures when participants vividly imagine pleasant, neutral, and unpleasant scenes. Results indicate that pleasant imagery selectively activates NAc and mPFC, whereas amygdala activation was enhanced during both pleasant and unpleasant imagery. NAc and mPFC activity were each correlated with the rated pleasure of the imagined scenes, while amygdala activity was correlated with rated emotional arousal. Functional connectivity of NAc and mPFC was evident throughout imagery, regardless of hedonic content, while correlated activation of the amygdala with NAc and mPFC was specific to imagining pleasant scenes. These findings provide strong evidence that pleasurable text-driven imagery engages a core appetitive circuit, including NAc, mPFC, and the amygdala. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source] Effects of lorazepam on visual perceptual abilitiesHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 3 2008S. Pompéia Abstract Objective To evaluate the effects of an acute dose of the benzodiazepine (BZ) lorazepam in young healthy volunteers on five distinguishable visual perception abilities determined by previous factor-analytic studies. Methods This was a double-blind, cross-over design study of acute oral doses of lorazepam (2,mg) and placebo in young healthy volunteers. We focused on a set of paper-and-pencil tests of visual perceptual abilities that load on five correlated but distinguishable factors (Spatial Visualization, Spatial Relations, Perceptual Speed, Closure Speed, and Closure Flexibility). Some other tests (DSST, immediate and delayed recall of prose; measures of subjective mood alterations) were used to control for the classic BZ-induced effects. Results Lorazepam impaired performance in the DSST and delayed recall of prose, increased subjective sedation and impaired tasks of all abilities except Spatial Visualization and Closure Speed. Only impairment in Perceptual Speed (Identical Pictures task) and delayed recall of prose were not explained by sedation. Conclusion Acute administration of lorazepam, in a dose that impaired episodic memory, selectively affected different visual perceptual abilities before and after controlling for sedation. Central executive demands and sedation did not account for results, so impairment in the Identical Pictures task may be attributed to lorazepam's visual processing alterations. Copyright © 2008 John Wiley & Sons, Ltd. [source] How HR professionals rate ,continuing professional development'HUMAN RESOURCE MANAGEMENT JOURNAL, Issue 3 2005Andrew Rothwell This article describes a research project undertaken with the co-operation of the UK's Chartered Institute of Personnel and Development, Derbyshire and Nottinghamshire branch, to investigate members' attitudes to and engagement with ,continuing professional development'(CPD), and how these correlated with a range of other variables and demographic characteristics. Women held more positive attitudes to the value of CPD than men. The majority of the most popular updating strategies were informal and organisationally located, with less emphasis on courses and qualifications. The most powerful predictor of the perceived value of CPD was professional commitment, while other attitudinal and demographic variables had weaker associations than expected. Valuing CPD did not necessarily translate into participating in it. Implications of this research include guidance for professional institutes on what CPD professionals engage in and why, and what influences this. [source] A preliminary report on the implication of RT,PCR detection of DAZ, RBMY1, USP9Y and Protamine-2 mRNA in testicular biopsy samples from azoospermic menINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2002A. Friel In this study, reverse transcription,polymerase chain reaction (RT,PCR) was optimized to analyse the presence of DAZ, RBMY1, USP9Y, protamine-2, SRY and actin messenger RNA (mRNA) in testicular cells of men suffering from idiopathic azoospermia. All samples (n=28), including five controls, showed normal expression of actin, SRY and USP9Y. Sperm was not recovered from eight patients after testicular biopsy. Of these, four patients showed altered mRNA levels for the fertility genes, DAZ, RBMY1 and protamine-2. One patient, who was previously shown to be azoospermia factor region (AZF)b deleted, lacked RBM mRNA and presented with reduced amplification of protamine-2 mRNA. This correlated with previous studies, which proposed that RBM expression is exclusive to AZFb and that the lack of testicular RBMY1 mRNA results in suppressed spermatogenesis. Two patients were each lacking DAZ mRNA but did show expression of RBMY1 mRNA at a reduced level, suggesting that there might be residual spermatogenesis in the absence of DAZ expression. Protamine-2 mRNA was detected in one patient and was absent in the second patient. Finally, one patient lacked DAZ, RBMY1 and protamine-2 mRNA. The 19 remaining azoospermic patients presented with normal expression patterns for each of the fertility genes studied. This study demonstrates that the expression of spermatogenesis-specific genes varies in azoospermia. The study of the expression of such genes in a larger number of patients might be useful in characterizing and identifying subpopulations of azoospermic men. [source] The combination of epigallocatechin gallate and curcumin suppresses ER,-breast cancer cell growth in vitro and in vivoINTERNATIONAL JOURNAL OF CANCER, Issue 9 2008Tiffany J. Somers-Edgar Abstract Both epigallocatechin gallate (EGCG) and curcumin have shown efficacy in various in vivo and in vitro models of cancer. This study was designed to determine the efficacy of these naturally derived polyphenolic compounds in vitro and in vivo, when given in combination. Studies in MDA-MB-231 cells demonstrated that EGCG + curcumin was synergistically cytotoxic and that this correlated with G2/M-phase cell cycle arrest. After 12 hr, EGCG (25 ,M) + curcumin (3 ,M) increased the proportion of cells in G2/M-phase to 263 ± 16% of control and this correlated with a 50 ± 4% decrease in cell number compared to control. To determine if this in vitro result would translate in vivo, athymic nude female mice were implanted with MDA-MB-231 cells and treated with curcumin (200 mg/kg/day, po), EGCG (25 mg/kg/day, ip), EGCG + curcumin, or vehicle control (5 ml/kg/day, po) for 10 weeks. Tumor volume in the EGCG + curcumin treated mice decreased 49% compared to vehicle control mice (p < 0.05), which correlated with a 78 ± 6% decrease in levels of VEGFR-1 protein expression in the tumors. Curcumin treatment significantly decreased tumor protein levels of EGFR and Akt, however the expression of these proteins was not further decreased following combination treatment. Therefore, these results demonstrate that the combination of EGCG and curcumin is efficacious in both in vitro and in vivo models of ER,- breast cancer and that regulation of VEGFR-1 may play a key role in this effect. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||