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Dominant Influence (dominant + influence)
Selected AbstractsThe significance of geographic range size for spatial diversity patterns in Neotropical palmsECOGRAPHY, Issue 1 2006Holger Kreft We examined the effect of range size in commonly applied macroecological analyses using continental distribution data for all 550 Neotropical palm species (Arecaceae) at varying grain sizes from 0.5° to 5°. First, we evaluated the relative contribution of range-restricted and widespread species on the patterns of species richness and endemism. Second, we analysed the impact of range size on the predictive value of commonly used predictor variables. Species sequences were produced arranging species according to their range size in ascending, descending, and random order. Correlations between the cumulative species richness patterns of these sequences and environmental predictors were performed in order to analyse the effect of range size. Despite the high proportion of rare species, patterns of species richness were found to be dominated by a minority of widespread species (,20%) which contained 80% of the spatial information. Climatic factors related to energy and water availability and productivity accounted for much of the spatial variation of species richness of widespread species. In contrast, species richness of range-restricted species was to a larger extent determined by topographical complexity. However, this effect was much more difficult to detect due to a dominant influence of widespread species. Although the strength of different environmental predictors changed with spatial scale, the general patterns and trends proved to be relatively stabile at the examined grain sizes. Our results highlight the difficulties to approximate causal explanations for the occurrence of a majority of species and to distinguish between contemporary climatic factors and history. [source] Designing a Stable Cathode with Multiple Layers to Improve the Operational Lifetime of Polymer Light-Emitting DiodesADVANCED FUNCTIONAL MATERIALS, Issue 12 2009Tae-Woo Lee Abstract The short device lifetime of blue polymer light-emitting diodes (PLEDs) is still a bottleneck for commercialization of self-emissive full-color displays. Since the cathode in the device has a dominant influence on the device lifetime, a systematic design of the cathode structure is necessary. The operational lifetime of blue PLEDs can be greatly improved by introducing a three-layer (BaF2/Ca/Al) cathode compared with conventional two-layer cathodes (BaF2/Al and Ba/Al). Therefore, the roles of the BaF2 and Ca layers in terms of electron injection, luminous efficiency, and device lifetime are here investigated. For efficient electron injection, the BaF2 layer should be deposited to the thickness of at least one monolayer (,3,nm). However, it is found that the device lifetime does not show a strong relation with the electron injection or luminous efficiency. In order to prolong the device lifetime, sufficient reaction between BaF2 and the overlying Ca layer should take place during the deposition where the thickness of each layer is around that of a monolayer. [source] Responses of dryland soil respiration and soil carbon pool size to abrupt vs. gradual and individual vs. combined changes in soil temperature, precipitation, and atmospheric [CO2]: a simulation analysisGLOBAL CHANGE BIOLOGY, Issue 9 2009WEIJUN SHEN Abstract With the large extent and great amount of soil carbon (C) storage, drylands play an important role in terrestrial C balance and feedbacks to climate change. Yet, how dryland soils respond to gradual and concomitant changes in multiple global change drivers [e.g., temperature (Ts), precipitation (Ppt), and atmospheric [CO2] (CO2)] has rarely been studied. We used a process-based ecosystem model patch arid land simulator to simulate dryland soil respiration (Rs) and C pool size (Cs) changes to abrupt vs. gradual and single vs. combined alterations in Ts, Ppt and CO2 at multiple treatment levels. Results showed that abrupt perturbations generally resulted in larger Rs and had longer differentiated impacts than did gradual perturbations. Rs was stimulated by increases in Ts, Ppt, and CO2 in a nonlinear fashion (e.g., parabolically or asymptotically) but suppressed by Ppt reduction. Warming mainly stimulated heterotrophic Rs (i.e., Rh) whereas Ppt and CO2 influenced autotrophic Rs (i.e., Ra). The combined effects of warming, Ppt, and CO2 were nonadditive of primary single-factor effects as a result of substantial interactions among these factors. Warming amplified the effects of both Ppt addition and CO2 elevation whereas Ppt addition and CO2 elevation counteracted with each other. Precipitation reduction either magnified or suppressed warming and CO2 effects, depending on the magnitude of factor's alteration and the components of Rs (Ra or Rh) being examined. Overall, Ppt had dominant influence on dryland Rs and Cs over Ts and CO2. Increasing Ppt individually or in combination with Ts and CO2 benefited soil C sequestration. We therefore suggested that global change experimental studies for dryland ecosystems should focus more on the effects of precipitation regime changes and the combined effects of Ppt with other global change factors (e.g., Ts, CO2, and N deposition). [source] The distribution of constitutional and somatic mutations in the neurofibromatosis 2 gene,HUMAN MUTATION, Issue 4 2006Michael E. Baser Abstract Constitutional heterozygous inactivating mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene cause the autosomal dominant disease NF2, and biallelic inactivating somatic NF2 mutations are found in a high proportion of unilateral sporadic vestibular schwannoma (USVS) and sporadic meningioma. We surveyed the distributions of constitutional NF2 mutations in 823 NF2 families, 278 somatic NF2 mutations in USVS, and 208 somatic NF2 mutations in sporadic meningioma. Based on the available NF2 mutation data, the most dominant influence on the spectra of mutations in exons 1,15 are C>T transitions that change arginine codons (CGA) to stop codons (TGA) due to spontaneous deamination of methylcytosine to thymine in CpG dinucleotides. The paucity of reported mutations in exon 9 and the absence of reported mutations in exons 16 and 17 may be related to structure,function relationships in the NF2 protein. Hum Mutat 27(4), 297-306, 2006. © 2006 Wiley-Liss, Inc. [source] Is rainfall intensity significant in the rainfall,runoff process within tropical rainforests of northeast Queensland?HYDROLOGICAL PROCESSES, Issue 18 2010The Hewlett regression analyses revisited Abstract Following the statistical analyses of long-term rainfall-runoff records from research basins in humid temperate latitudes, Hewlett and co-workers extended the global challenge to disprove their findings that rainfall intensity was non-significant. This paper responds to Hewlett's challenge as no preceding analyses have involved forested basins in a tropical cyclone-prone area. Based on a 7 year rainfall-runoff record, quickflow (QF), peak flow (QP) and quickflow response ratios (QRR) were regressed as dependent variables against rainfall parameters (intensity, Pi, amount, P), storm duration, D and antecedent flow, I. These data sets were categorised into total streamflow (Q) classes and stratified into three seasons, (monsoon, post-monsoon and dry) for forested and cleared catchments. Where rainfall variable collinearity met acceptable levels, the addition of Pi to regression models including P, D, I contributed up to 9% and 66% of the respective variations in quickflow and peak flow. For the highest Q storm classes (monsoon), Pi alone accounted for up to 67% and 91% of the variation in QF and QP respectively and was the dominant influence on QP for all seasons. The very high rainfall intensities experienced in the monsoon season is a causal factor why these results differ from those of other research drainage basins. Surprisingly, Pi continued to have a significant influence on QF for dry season classes when less-intense rainfall occurs. Further the results were similar for both catchments across all seasons. P was the dominant independent variable affecting QF above a threshold Q of 50 mm (monsoon), as rainfall contributes directly to saturation overland flow and return flow under saturated conditions. Further although QRR increased with increasing Q for each season, the regression results for that parameter were poor possibly due to the non-linearity of the rainfall-runoff relationship. Copyright © 2010 John Wiley & Sons, Ltd. [source] Rainfall,runoff modelling of ephemeral streams in the Valencia region (eastern Spain)HYDROLOGICAL PROCESSES, Issue 17 2002Ana M. Camarasa Abstract This paper presents preliminary results from the application of a transfer-function rainfall,runoff model to ephemeral streams in Mediterranean Spain. Flow simulations have been conducted for two small catchments (Carraixet and Poyo basins), located in close proximity to one another yet with significantly different geological characteristics. Analysis of flow simulations for a number of high-flow events has revealed the dominant influence of the rainfall on the catchment response, particularly for high-rainfall events. Particular success has been attained modelling the highest magnitude events in both catchments and for all events in the faster responding (Poyo) catchment. In order to investigate the viability of the model for forecasting floods in ungauged catchments, additional investigations have been conducted by calibrating the model for one catchment (donor catchment) and then applying it to another (receptor catchment). The results indicate that this can be successful when either the donor catchment is a fast response catchment or when the model is calibrated using a high-magnitude event in the donor catchment, providing that the modelled receptor catchment event is of a lower magnitude. Copyright © 2002 John Wiley & Sons, Ltd. [source] Simulating forest ecosystem response to climate warming incorporating spatial effects in north-eastern ChinaJOURNAL OF BIOGEOGRAPHY, Issue 12 2005Hong S. He Abstract Aim, Predictions of ecosystem responses to climate warming are often made using gap models, which are among the most effective tools for assessing the effects of climate change on forest composition and structure. Gap models do not generally account for broad-scale effects such as the spatial configuration of the simulated forest ecosystems, disturbance, and seed dispersal, which extend beyond the simulation plots and are important under changing climates. In this study we incorporate the broad-scale spatial effects (spatial configurations of the simulated forest ecosystems, seed dispersal and fire disturbance) in simulating forest responses to climate warming. We chose the Changbai Natural Reserve in China as our study area. Our aim is to reveal the spatial effects in simulating forest responses to climate warming and make new predictions by incorporating these effects in the Changbai Natural Reserve. Location, Changbai Natural Reserve, north-eastern China. Method, We used a coupled modelling approach that links a gap model with a spatially explicit landscape model. In our approach, the responses (establishment) of individual species to climate warming are simulated using a gap model (linkages) that has been utilized previously for making predictions in this region; and the spatial effects are simulated using a landscape model (LANDIS) that incorporates spatial configurations of the simulated forest ecosystems, seed dispersal and fire disturbance. We used the recent predictions of the Canadian Global Coupled Model (CGCM2) for the Changbai Mountain area (4.6 °C average annual temperature increase and little precipitation change). For the area encompassed by the simulation, we examined four major ecosystems distributed continuously from low to high elevations along the northern slope: hardwood forest, mixed Korean pine hardwood forest, spruce-fir forest, and sub-alpine forest. Results, The dominant effects of climate warming were evident on forest ecosystems in the low and high elevation areas, but not in the mid-elevation areas. This suggests that the forest ecosystems near the southern and northern ranges of their distributions will have the strongest response to climate warming. In the mid-elevation areas, environmental controls exerted the dominant influence on the dynamics of these forests (e.g. spruce-fir) and their resilience to climate warming was suggested by the fact that the fluctuations of species trajectories for these forests under the warming scenario paralleled those under the current climate scenario. Main conclusions, With the spatial effects incorporated, the disappearance of tree species in this region due to the climate warming would not be expected within the 300-year period covered by the simulation. Neither Korean pine nor spruce-fir was completely replaced by broadleaf species during the simulation period. Even for the sub-alpine forest, mountain birch did not become extinct under the climate warming scenario, although its occurrence was greatly reduced. However, the decreasing trends characterizing Korean pine, spruce, and fir indicate that in simulations beyond 300 years these species could eventually be replaced by broadleaf tree species. A complete forest transition would take much longer than the time periods predicted by the gap models. [source] Influence of CYP2C9 and CYP2C19 genetic polymorphisms on pharmacokinetics and pharmacodynamics of gliclazide in healthy Chinese Han volunteersJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 3 2010H. Shao PhD Summary Background and objective:,CYP2C9 is the major contributor to gliclazide metabolic clearance in vitro, while the pharmacokinetics of gliclazide modified release are affected mainly by CYP2C19 genetic polymorphisms in vivo. This study aims to investigate the influence of CYP2C9 and CYP2C19 genetic polymorphisms on the pharmacokinetics and pharmacodynamics of gliclazide in healthy Chinese Han volunteers. Methods:, Eighteen healthy Han subjects with various combinations of CYP2C9 and CYP2C19 genotypes received 80 mg gliclazide. Plasma gliclazide concentrations were measured by a liquid chromatography,tandem mass spectrometry method for 84 h and plasma glucose and insulin levels were measured up to 15 h post-dose. Results and discussion:, There was no difference in either pharmacokinetic and or pharmacodynamic parameters of gliclazide when group A (CYP2C9*1/*1, CYP2C19 extensive metabolizers) was compared with group B (CYP2C9*1/*3, CYP2C19 *1/*1). When group C (CYP2C9*1/*1 and CYP2C19 poor metabolizers) was compared with group A, the AUC0,, and Cmax in group C were significantly higher [83·94 ± 40·41 vs. 16·39 ± 5·10 ,g·h/mL (P = 0·000) and 1·50 ± 0·85 vs. 0·45 ± 0·18 ,g/mL (P = 0·000)], and the oral clearance was significantly lower [1·17 ± 0·63 vs. 5·38 ± 1·86 L/h (P = 0·000)]. The half-life of gliclazide was also significantly prolonged in group C subjects when compared with that of group A (33·47 ± 12·39 vs. 19·34 ± 10·45 h), but the difference was not significant (P = 0·052). The increase in serum glucose level at 11 h after dosing (,Cglu11) in group C was significantly higher than that of group A (,1·08 ± 0·42 vs. 0·22 ± 1·01 mmol/L, P = 0·022). The corresponding insulin levels showed no difference between the two groups. Conclusion:,CYP2C9*3 was not associated with any change in the disposition of gliclazide. CYP2C19 polymorphisms appear to exert the dominant influence on the pharmacokinetics of gliclazide in healthy Chinese Han subjects, and may also affect the observed pharmacodynamics of the drug as a result. [source] Nutrients, not caloric restriction, extend lifespan in Queensland fruit flies (Bactrocera tryoni)AGING CELL, Issue 5 2009Benjamin G. Fanson Summary Caloric restriction (CR) has been widely accepted as a mechanism explaining increased lifespan (LS) in organisms subjected to dietary restriction (DR), but recent studies investigating the role of nutrients have challenged the role of CR in extending longevity. Fuelling this debate is the difficulty in experimentally disentangling CR and nutrient effects due to compensatory feeding (CF) behaviour. We quantified CF by measuring the volume of solution imbibed and determined how calories and nutrients influenced LS and fecundity in unmated females of the Queensland fruit fly, Bactocera tryoni (Diptera: Tephritidae). We restricted flies to one of 28 diets varying in carbohydrate:protein (C:P) ratios and concentrations. On imbalanced diets, flies overcame dietary dilutions, consuming similar caloric intakes for most dilutions. The response surface for LS revealed that increasing C:P ratio while keeping calories constant extended LS, with the maximum LS along C:P ratio of 21:1. In general, LS was reduced as caloric intake decreased. Lifetime egg production was maximized at a C:P ratio of 3:1. When given a choice of separate sucrose and yeast solutions, each at one of five concentrations (yielding 25 choice treatments), flies regulated their nutrient intake to match C:P ratio of 3:1. Our results (i) demonstrate that CF can overcome dietary dilutions; (ii) reveal difficulties with methods presenting fixed amounts of liquid diet; (iii) illustrate the need to measure intake to account for CF in DR studies and (iv) highlight nutrients rather than CR as a dominant influence on LS. [source] Exposure of mouse preosteoblasts to pulsed electromagnetic fields reduces the amount of mature, type I collagen in the extracellular matrixJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2006Yoshitada Sakai Abstract We tested the hypothesis that exposure of a mouse preosteoblast cell line to pulsed electromagnetic fields (PEMF) would affect components of the extracellular matrix. We report that exposure of MC3T3-E1 cells to a single PEMF waveform significantly reduced the amount of mature, ,1(I) collagen in the extracellular matrix (ECM) and the conditioned medium, without affecting the amount of total ECM protein. This decrease was not due to changes in the steady-state level of Col1A1 mRNA or to degradation of mature collagen. We then tested the effect of three distinct PEMF waveforms, two orthogonal coil orientations, and two waveform amplitude levels on the amount of ,1(I) collagen in the conditioned medium. A sequence of factorial ANOVAs and stepwise regression modeling revealed that the period (duration) of the individual pulses accounted for a significant proportion of the variance associated with the amount of ,1(I) collagen in the conditioned medium. The total variance accounted for, however, was small (R2,=,0.155, p,<,0.001 and R2,=,0.172, p,<,0.001, in the horizontal and vertical orientations, respectively). The positive and negative regression coefficients for the coil orientations revealed that the influence of pulse period was significantly different for the orthogonal coil orientations (p,<,0.001). The findings imply that the dominant influence of PEMF on the amount of mature, ,1(I) collagen in the ECM is related to variables other than those expressed in the time-amplitude domain. The results provide objective direction toward identifying waveform characteristics that contribute to the observed between-waveform differences with regard to collagen. Advances in this area may lead toward improving waveforms and waveform delivery protocols. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] Oxygen isotope and palaeotemperature records from six Greenland ice-core stations: Camp Century, Dye-3, GRIP, GISP2, Renland and NorthGRIPJOURNAL OF QUATERNARY SCIENCE, Issue 4 2001Sigfus J. Johnsen Abstract Oxygen isotope variations spanning the last glacial cycle and the Holocene derived from ice-core records for six sites in Greenland (Camp Century, Dye-3, GRIP, GISP2, Renland and NorthGRIP) show strong similarities. This suggests that the dominant influence on oxygen isotope variations reflected in the ice-sheet records was regional climatic change. Differences in detail between the records probably reflect the effects of basal deformation in the ice as well as geographical gradients in atmospheric isotope ratios. Palaeotemperature estimates have been obtained from the records using three approaches: (i) inferences based on the measured relationship between mean annual ,18O of snow and of mean annual surface temperature over Greenland; (ii) modelled inversion of the borehole temperature profile constrained either by the dated isotopic profile, or (iii) by using Monte Carlo simulation techniques. The third of these approaches was adopted to reconstruct Holocene temperature variations for the Dye 3 and GRIP temperature profiles, which yields remarkably compatible results. A new record of Holocene isotope variations obtained from the NorthGRIP ice-core matches the GRIP short-term isotope record, and also shows similar long-term trends to the Dye-3 and GRIP inverted temperature data. The NorthGRIP isotope record reflects: (i) a generally stronger isotopic signal than is found in the GRIP record; (ii) several short-lived temperature fluctuations during the first 1500 yr of the Holocene; (iii) a marked cold event at ca. 8.2 ka (the ,8.2 ka event'); (iv) optimum temperatures for the Holocene between ca. 8.6 and 4.3 ka, a signal that is 0.6, stronger than for the GRIP profile; (v) a clear signal for the Little Ice Age; and (vi) a clear signal of climate warming during the last century. These data suggest that the NorthGRIP stable isotope record responded in a sensitive manner to temperature fluctuations during the Holocene. Copyright © 2001 John Wiley & Sons, Ltd. [source] Spectroscopic Properties and Thermal Stability of Er3+ -Doped Germanotellurite Glasses for Broadband Fiber AmplifiersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2001Xian Feng The thermal stability and spectroscopic properties of Er2O3 -doped TeO2,GeO2,ZnO,Na2O,Y2O3 glasses for 1.5 ,m fiber amplifiers were investigated. The thermal stability of the 75TeO2·20ZnO· 5Na2O glass was improved by introducing GeO2 and Y2O3. The radiative transition and the nonradiative transition have a dominant influence on the 4I13/2 level lifetime of Er3+ in high- and low-GeO2 regions, respectively. Adding Y2O3 increases the 4I13/2 level lifetime of Er3+ significantly. The Judd,Ofelt (J-O) parameter ,6 shows a strong correlation with the 1.5 ,m emission bandwidth; and the larger the ,6, the wider the bandwidth. [source] The parameterization of solid metal-liquid metal partitioning of siderophile elementsMETEORITICS & PLANETARY SCIENCE, Issue 10 2003Nancy L. CHABOT We present a method for parameterizing solid metal-liquid metal partition coefficients for siderophile (metal-loving) elements as a function of the metallic liquid composition. Our parameterization method is based on an older theory of Jones and Malvin (1990), which stated that the metallic liquid is composed of metal and non-metal-bearing domains, and the domains are the dominant influence on the partitioning behavior. By revising the means by which the metal domains are calculated, our revised parameterization method is able to match experimental partitioning data from the Fe-Ni-S, Fe-Ni-P, Fe-Ni-S-P, and Fe-Ni-C systems. Mathematical expressions were derived for the solid metal-liquid metal partitioning of 13 siderophile elements. Elements that are chalcophile (S-loving), P-loving, or C-loving prefer the non-metal-bearing domains in the metallic liquid and, consequently, aren't fit by the parameterization method presented here. Possible applications for our parameterization method include modeling the crystallization of iron meteorites, planetary differentiation, and the solidification of Earth's inner core. [source] Design for synergy with brand or price information,PSYCHOLOGY & MARKETING, Issue 7 2010Ravindra Chitturi Customers' preference for the hedonic benefits (e.g., aesthetics) and utilitarian benefits (e.g., functionality) offered by a product varies depending on the context,buying versus selling, and choice versus willingness-to-pay. However, a customer's preference formation could involve brand information or price information in addition to the benefits offered by the product. It is unclear how the consideration of brand or price information influences customers' relative preference for hedonic and utilitarian product benefits. Does this information alter preference in favor of a product that offers greater utilitarian or greater hedonic benefits, and why? The results show that (1) hedonic (utilitarian) attributes have a significantly stronger influence on consumer preference when accompanied by a strong (weak) versus a weak (strong) brand; and (2) in the presence of price information, hedonic attributes have a dominant influence on consumer preference compared to in the absence of price information. The article concludes with a discussion of the theoretical contributions and managerial implications of design for synergy with brand or price information. © 2010 Wiley Periodicals, Inc. [source] How Big Was the Effect of Budget Consolidation on the Australian Economy in the 1990s?THE AUSTRALIAN ECONOMIC REVIEW, Issue 1 2006Lei Lei Song This article evaluates the effects of budget consolidation on the Australian economy in the 1990s. As the economy recovered from the 1991,92 recession, the need to improve the fiscal balance to lift national saving became the dominant influence on fiscal policy. The article argues that spending cuts by the Australian federal government announced in 1996 had immediate effects on financial markets, with reduced long-term interest rates of about 50 basis points in 1996,97. Using a modified version of the Treasury macroeconometric model of the Australian economy (TRYM), the article simulates the net macroeconomic effects of the expenditure cuts, fiscal consolidation and lower long-term interest rates. The article finds that the program of budget consolidation had a sizeable short- and medium-term impact on the economy, raising Gross Domestic Product by up to three-quarters of a percentage point and reducing unemployment by 0.3 percentage points over the next two to three years. [source] Change in the dominant decadal patterns and the late 1980s abrupt warming in the extratropical Northern HemisphereATMOSPHERIC SCIENCE LETTERS, Issue 3 2010Tzu-Ting Lo Abstract Widespread abrupt warming in the extratropical Northern Hemisphere (NH) occurred in the late 1980s. This warming was associated with a change in the relative influence of the Pacific Decadal Oscillation (PDO)-like pattern and the Arctic Oscillation (AO)-like pattern. The AO-like pattern has had a dominant influence on the NH-mean temperature since the late 1980s, whereas the influence of the PDO has weakened. The AO-like mode appears as part of natural variability in the pre-industrial simulations of the CMIP3/IPCC climate models. However, its emergence in the late 1980s was not simulated by most models with or without the observed increasing greenhouse effect in the 20th century. Copyright © 2010 Royal Meteorological Society [source] Seedling establishment, mortality, tree growth rates and vigour of Acacia nilotica in different Astrebla grassland habitats: Implications for invasionAUSTRAL ECOLOGY, Issue 3 2002Ian 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] Dermatological aspects of angiogenesisBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2002P. Velasco Summary Neovascularization is vital for the growth of tumours, providing a lifeline for sustenance and waste disposal. Tumour vessels can grow by sprouting, intussusception or by incorporating bone marrow-derived endothelial precursor cells into growing vessels. Recent advances in vascular biology have identified some key factors that control vascular growth, and have led to the hypothesis that in normal tissues vascular quiescence is maintained by the dominant influence of endogenous angiogenesis inhibitors over angiogenic stimuli. In contrast, increased secretion of angiogenic factors and the down-regulation of endogenous angiogenesis inhibitors induce tumour angiogenesis. Vascular quiescence in the skin seems to be primarily maintained by a balance between the endogenous angiogenesis inhibitors thrombospondin 1 and thrombospondin 2 and the potent proangiogenic factor vascular endothelial growth factor A. Inhibiting tumour growth by controlling angiogenesis is an intriguing approach with great potential for the treatment of vascular tumours such as haemangioma, Kaposi's sarcoma and solid cutaneous tumours such as squamous cell carcinoma, melanoma and basal cell carcinoma. In this review, the role of angiogenesis and more recent topics such as lymphangiogenesis in cutaneous tumour growth, invasion and metastasis will be discussed. [source] Information and Values in Popular Protests: Costa Rica in 2000BULLETIN OF LATIN AMERICAN RESEARCH, Issue 1 2009EDUARDO FRAJMAN The mass demonstrations in Costa Rica in 2000 opposing a government initiative to deregulate the electricity and telecommunications markets point to the importance of the paths of communication between the people and government leaders to understand mass political mobilisation. This article explains the surprising reaction of the Costa Rican public by focusing on the unwillingness or inability of the policy-makers to articulate their position in a way acceptable to the citizenry, leaving public space under the dominant influence of social organisations that opposed the initiative. [source] Role of hematopoietic lineage cells as accessory components in blood vessel formationCANCER SCIENCE, Issue 7 2006Nobuyuki Takakura In adults, the vasculature is normally quiescent, due to the dominant influence of endogenous angiogenesis inhibitors over angiogenic stimuli. However, blood vessels in adults retain the capacity for brisk initiation of angiogenesis, the growth of new vessels from pre-existing vessels, during tissue repair and in numerous diseases, including inflammation and cancer. Because of the role of angiogenesis in tumor growth, many new cancer therapies are being conducted against tumor angiogenesis. It is thought that these anti-angiogenic therapies destroy the tumor vessels, thereby depriving the tumor of oxygen and nutrients. Therefore, a better understanding of the molecular mechanisms in the process of sprouting angiogenesis may lead to more effective therapies not only for cancer but also for diseases involving abnormal vasculature. It is widely believed that after birth, endothelial cells (EC) in new blood vessels are derived from resident EC of pre-existing vessels. However, evidence is now emerging that cells derived from the bone marrow may also contribute to postnatal angiogenesis. Most studies have focused initially on the contribution of endothelial progenitor cells in this process. However, we have proposed a concept in which cells of the hematopoietic lineage are mobilized and then entrapped in peripheral tissues, where they function as accessory cells that promote the sprouting of resident EC by releasing angiogenic signals. Most recently we found that hematopoietic cells play major roles in tumor angiogenesis by initiating sprouting angiogenesis and also in maturation of blood vessels in the fibrous cap of tumors. Therefore, manipulating these entrapment signals may offer therapeutic opportunities to stimulate or inhibit angiogenesis. (Cancer Sci 2006; 97: 568,574) [source] Vested Interests in Addiction Research and Policy Poisonous partnerships: health sector buy-in to arrangements with government and addictive consumption industriesADDICTION, Issue 4 2010Peter J. Adams ABSTRACT Aim This paper critically appraises relationship arrangements among three broadly conceived sectors: the government sector, the health sector (including researchers) and addictive consumption industries (particularly tobacco, alcohol and gambling). Method Three models for involvement are examined. In the ,tripartite partnership model' health sector agencies engage as co-equals with the government and industry sectors in order to implement public health initiatives such as host responsibility and public education. In the ,non- association model' the health sector engages with government agencies but not with the industry sector. In the ,managed association model' the health sector engages for specific purposes with the industry sector but contact is monitored and managed by government agencies. Findings Government and industry sectors commonly favour tripartite partnership arrangements. Health sector agencies that opt to engage in these partnership arrangements can encounter conflicts of interest and find their voice subsumed by dominant influences. Furthermore, their partnership compliance generates divisions within the health sector, with partnership dissenters often silenced and excluded from policy processes and funding. The non-association model is the least hazardous to the health sector because it protects against compromise and dominance. The managed association model is an option only when the government sector as a whole is committed strongly and clearly to the public health objectives. Conclusion In contexts where key parts of the government sector are conflicted over their public health responsibilities, health sector engagement in partnership arrangements entails too many risks. [source] Guidebook use by Japanese tourists: a qualitative study of Australia inbound travellersINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 1 2006Sachiko Nishimura Abstract This qualitative investigation into guidebook use reports on in-depth interviews conducted with 26 Japanese individuals and one couple who had visited Australia during the five previous years. Focusing on the stages before, during and after travel the research framework was based on Vogt and Fesenmaier's model of information needs. It was found that functional needs were the dominant influences during the prior to travel phase, with some non-functional needs (hedonic, aesthetic and innovation) also being influential. During the travel phase, only functional needs were evident. Some respondents were identified as being deliberate non-users of guidebooks. The variable ,tourist type' was found to be helpful for distinguishing between users and non-users and for identifying those with functional needs. The use of guidebooks by those whose needs are both functional and non-functional may be unaffected by this variable. When the attitudes of those who actively dislike guidebooks and those who hesitate to use them are aggregated, a view emerges of guidebooks as a symbol of standardised tourism. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||