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Stronger Influence (stronger + influence)
Selected AbstractsEffects of Pair-Bond and Social Context on Male,Female Interactions in Captive Titi Monkeys (Callicebus moloch, Primates: Cebidae)ETHOLOGY, Issue 12 2000Eduardo Fernandez-Duque In monogamous species, an abiding relationship between a specific adult male and a specific adult female is a defining feature of the social system. The interactions between these individuals are influenced by many factors, including not only the history of their relationship (for example, development of a mutual bond), but also the immediate effects of the prevailing social context (for example, presence and sex of extra-pair conspecifics). In this study we examined the effects of an existing bond and of social context on interactions between adult heterosexual pairs of the monogamous titi monkeys (Callicebus moloch). Twelve adult males and 12 adult females were tested with their cagemates and with an unfamiliar partner of the opposite sex in five social contexts: (1) mated male,female pair; (2) unfamiliar pair; (3) single female; (4) single male; and (5) empty stimulus cage. Results show that mated pairs were more affiliative than unfamiliar pairs and differentiated social contexts more sharply. Males were more responsive to context than females. Distance between mates was less and physical contact was more frequent in the presence of male,female pairs or a single male, than in the presence of a single female or an empty cage. These findings suggest that the presence and sex of strangers have a stronger influence on male,female interactions when the pair has an existing relationship. [source] Do changes in climate patterns in wintering areas affect the timing of the spring arrival of trans-Saharan migrant birds?GLOBAL CHANGE BIOLOGY, Issue 1 2005Oscar Gordo Abstract The life cycles of plants and animals are changing around the world in line with the predictions originated from hypotheses concerning the impact of global warming and climate change on biological systems. Commonly, the search for ecological mechanisms behind the observed changes in bird phenology has focused on the analysis of climatic patterns from the species breeding grounds. However, the ecology of bird migration suggests that the spring arrival of long-distance migrants (such as trans-Saharan birds) is more likely to be influenced by climate conditions in wintering areas given their direct impact on the onset of migration and its progression. We tested this hypothesis by analysing the first arrival dates (FADs) of six trans-Saharan migrants (cuckoo Cuculus canorus, swift Apus apus, hoopoe Upupa epops, swallow Hirundo rustica, house martin Delichon urbica and nightingale Luscinia megarhynchos), in a western Mediterranean area since from 1952 to 2003. By means of multiple regression analyses, FADs were analysed in relation to the monthly temperature and precipitation patterns of five African climatic regions south of the Sahara where species are thought to overwinter and from the European site from where FADs were collected. We obtained significant models for five species explaining 9,41% of the variation in FADs. The interpretation of the models suggests that: (1) The climate in wintering quarters, especially the precipitation, has a stronger influence on FADs than that in the species' potential European breeding grounds. (2) The accumulative effects of climate patterns prior to migration onset may be of considerable importance since those climate variables that served to summarize climate patterns 12 months prior to the onset of migration were selected by final models. (3) Temperature and precipitation in African regions are likely to affect departure decision in the species studied through their indirect effects on food availability and the build-up of reserves for migration. Our results concerning the factors that affect the arrival times of trans-Saharan migrants indicate that the effects of climate change are more complex than previously suggested, and that these effects might have an interacting impact on species ecology, for example by reversing ecological pressures during species' life cycles. [source] Wavelet analysis of inter-annual variability in the runoff regimes of glacial and nival stream catchments, Bow Lake, AlbertaHYDROLOGICAL PROCESSES, Issue 6 2003Melissa Lafrenière Abstract Continuous wavelet analyses of hourly time series of air temperature, stream discharge, and precipitation are used to compare the seasonal and inter-annual variability in hydrological regimes of the two principal streams feeding Bow Lake, Banff National Park, Alberta: the glacial stream draining the Wapta Icefields, and the snowmelt-fed Bow River. The goal is to understand how water sources and flow routing differ between the two catchments. Wavelet spectra and cross-wavelet spectra were determined for air temperature and discharge from the two streams for summers (June,September) 1997,2000, and for rainfall and discharge for the summers of 1999 and 2000. The diurnal signal of the glacial runoff was orders of magnitude higher in 1998 than in other years, indicating that significant ice exposure and the development of channelized glacial drainage occurred as a result of the 1997,98 El Niño conditions. Early retreat of the snowpack in 1997 and 1998 led to a significant summer-long input of melt runoff from a small area of ice cover in the Bow River catchment; but such inputs were not apparent in 1999 and 2000, when snow cover was more extensive. Rainfall had a stronger influence on runoff and followed quicker flow paths in the Bow River catchment than in the glacial catchment. Snowpack thickness and catchment size were the primary controls on the phase relationship between temperature and discharge at diurnal time scales. Wavelet analysis is a fast and effective means to characterize runoff, temperature, and precipitation regimes and their interrelationships and inter-annual variability. The technique is effective at identifying inter-annual and seasonal changes in the relative contributions of different water sources to runoff, and changes in the time required for routing of diurnal meltwater pulses through a catchment. However, it is less effective at identifying changes/differences in the type of the flow routing (e.g. overland flow versus through flow) between or within catchments. Copyright © 2003 John Wiley & Sons, Ltd. [source] Do Applicants' Perceptions Matter?INTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 4 2007Investigating Reapplication Behavior Using Fairness Theory This study used a fairness theory approach to examine a link between applicants' perceptions and their actual reapplication behavior. We suggested that applicants who do not receive job offers form ,Would' counterfactuals based on perceived performance and ,Should' counterfactuals based on two procedural justice rules (job relatedness and opportunity to perform). Participants (N=542) were applicants for a United States federal government position. After not being hired in the initial selection process, 9% of the applicants reapplied for the job the following year. We found some support for the hypothesized interactions. The job relatedness,perceived performance interaction was not significant, but the opportunity to perform,perceived performance interaction was. Opportunity to perform had a stronger influence when perceived performance was higher. [source] Effect of ethylene glycidyl methacrylate compatibilizer on the structure and mechanical properties of clay nanocomposites modified with ethylene vinyl acetate copolymerJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2007B. R. Guduri Abstract The structure and mechanical properties of clay modified with ethylene vinyl acetate copolymer in the presence of ethylene glycidyl methacrylate (EGMA) were investigated as a function of compatibilizer and clay contents. The structure and properties were determined by X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis (TGA). The presence of EGMA caused strong exfoliation of the clay in the polymer matrix, although at higher clay contents, some clay layers still existed. The more effective exfoliation, however, did not seem to substantially influence the tensile properties of the nanocomposites because the EGMA itself had a much stronger influence, which overshadowed any possible influence that the EGMA,clay interaction may have had on these properties. The thermal stability of the nanocomposites (as studied by TGA) improved in the presence of EGMA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4095,4101, 2007 [source] Interaction Effects in the Theory of Planned Behavior: The Interplay of Self-Identity and Past BehaviorJOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 11 2007Joanne R. Smith This research used a revised theory of planned behavior (TPB) model, which incorporated self-identity and past behavior,and the interaction between these constructs,in order to improve the model's predictive power in relation to consumer behavior (purchasing one's preferred beer). At Time 1, respondents (N = 108) completed measures of attitudes, perceived behavioral control, subjective norm, self-identity, past behavior, and intentions. Behavior was assessed 1 week later. All predictors were positively related to intentions. Self-identity and past behavior interacted to influence intentions: Self-identity had a stronger influence on intentions at low, rather than high, levels of past behavior. Intentions and past behavior were predictive of Time 2 behavior. These findings emphasize the need to consider identity issues in the TPB. [source] Fish assemblages of the Casiquiare River, a corridor and zoogeographical filter for dispersal between the Orinoco and Amazon basinsJOURNAL OF BIOGEOGRAPHY, Issue 9 2008Kirk O. Winemiller Abstract Aim, The aim of this study was to determine whether the Casiquiare River functions as a free dispersal corridor or as a partial barrier (i.e. filter) for the interchange of fish species of the Orinoco and Negro/Amazon basins using species assemblage patterns according to geographical location and environmental features. Location, The Casiquiare, Upper Orinoco and Upper Negro rivers in southern Venezuela, South America. Methods, Our study was based on an analysis of species presence/absence data and environmental information (11 habitat characteristics) collected by the authors and colleagues between the years 1984 and 1999. The data set consisted of 269 sampled sites and 452 fish species (> 50,000 specimens). A wide range of habitat types was included in the samples, and the collection sites were located at various points along the entire length of the Casiquiare main channel, at multiple sites on its tributary streams, as well as at various nearby sites outside the Casiquiare drainage, within the Upper Orinoco and Upper Rio Negro river systems. Most specimens and field data used in this analysis are archived in the Museo de Ciencias Naturales in Guanare, Venezuela. We performed canonical correspondence analysis (CCA) based on species presence/absence using two versions of the data set: one that eliminated sites having < 5 species and species occurring at < 5 sites; and another that eliminated sites having < 10 species and species occurring at < 10 sites. Cluster analysis was performed on sites based on species assemblage similarity, and a separate analysis was performed on species based on CCA loadings. Results, The CCA results for the two versions of the data set were qualitatively the same. The dominant environmental axis contrasted assemblages and sites associated with blackwater vs. clearwater conditions. Longitudinal position on the Casiquiare River was correlated (r2 = 0.33) with CCA axis-1 scores, reflecting clearwater conditions nearer to its origin (bifurcation of the Orinoco) and blackwater conditions nearer to its mouth (junction with the Rio Negro). The second CCA axis was most strongly associated with habitat size and structural complexity. Species associations derived from the unweighted pair-group average clustering method and pair-wise squared Euclidean distances calculated from species loadings on CCA axes 1 and 2 showed seven ecological groupings. Cluster analysis of species assemblages according to watershed revealed a stronger influence of local environmental conditions than of geographical proximity. Main conclusions, Fish assemblage composition is more consistently associated with local environmental conditions than with geographical position within the river drainages. Nonetheless, the results support the hypothesis that the mainstem Casiquiare represents a hydrochemical gradient between clearwaters at its origin and blackwaters at its mouth, and as such appears to function as a semi-permeable barrier (environmental filter) to dispersal and faunal exchanges between the partially vicariant fish faunas of the Upper Orinoco and Upper Negro rivers. [source] Habitual Levels of Physical Activity Influence Bone Mass in 11-Year-Old Children From the United Kingdom: Findings From a Large Population-Based Cohort,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2007Jon H Tobias MD Abstract We examined the influence of habitual levels of physical activity on bone mass in childhood by studying the relationship between accelerometer recordings and DXA parameters in 4457 11-year-old children. Physical activity was positively related to both BMD and bone size in fully adjusted models. However, further exploration revealed that this effect on bone size was modified by fat mass. Introduction: Exercise interventions have been reported to increase bone mass in children, but it is unclear whether levels of habitual physical activity also influence skeletal development. Materials and Methods: We used multivariable linear regression to analyze associations between amount of moderate and vigorous physical activity (MVPA), derived from accelerometer recordings for a minimum of 3 days, and parameters obtained from total body DXA scans in 4457 11-year-old boys and girls from the Avon Longitudinal Study of Parents and Children. The influence of different activity intensities was also studied by stratification based on lower and higher accelerometer cut-points for moderate (3600 counts/minute) and vigorous (6200 counts/minute) activity, respectively. Results: MVPA was positively associated with lower limb BMD and BMC adjusted for bone area (aBMC; p < 0.001, adjusted for age, sex, socio-economic factors, and height, with or without additional adjustment for lean and fat mass). MVPA was inversely related to lower limb bone area after adjusting for height and lean mass (p = 0.01), whereas a positive association was observed when fat mass was also adjusted for (p < 0.001). Lower limb BMC was positively related to MVPA after adjusting for height and lean and fat mass (p < 0.001), whereas little relationship was observed after adjusting for height and lean mass alone (p = 0.1). On multivariable regression analysis using the fully adjusted model, moderate activity exerted a stronger influence on lower limb BMC compared with light activity (light activity: 2.9 [1.2,4.7, p = 0.001]; moderate activity: 13.1 [10.6,15.5, p < 0.001]; regression coefficients with 95% confidence intervals and p values). Conclusions: Habitual levels of physical activity in 11-year-old children are related to bone size and BMD, with moderate activity exerting the strongest influence. The effect on bone size (as reflected by DXA-based measures of bone area) was modified by adjustment for fat mass, such that decreased fat mass, which is associated with higher levels of physical activity, acts to reduce bone size and thereby counteract the tendency for physical activity to increase bone mass. [source] Multiple organizational identification levels and the impact of perceived external prestige and communication climateJOURNAL OF ORGANIZATIONAL BEHAVIOR, Issue 2 2007Jos Bartels Earlier studies have shown that perceived external prestige and communication climate influence organizational identification. In this paper we present the results of a study of the influence of communication climate and perceived external prestige on organizational identification at various organizational levels of a regional police organization. In total, 314 respondents filled out a questionnaire on communication climate, perceived external prestige and organizational identification. The results of this study show that communication climate has the strongest link with employee identification when it concerns the identification with the daily work group and a weaker one with the organization as a whole. It also appears that perceived external prestige has a stronger influence on the identification with the organization as a whole than on the identification at the more concrete organizational levels (such as department or work group). This research offers reasons to presuppose that organizational identification and communication climate are multiple constructs. If management wishes to influence organizational identification through a bottom-up process, it is wise to pay particular attention to the communication climate in the work groups. Influencing organizational identification with the organization as a whole is better conducted through perceived external prestige. Copyright © 2006 John Wiley & Sons, Ltd. [source] Comparison of the Temperature-Dependent Ferroelastic Behavior of Hard and Soft Lead Zirconate Titanate CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2010Mie Marsilius The ferroelastic properties of a hard acceptor-doped lead zirconate titanate (PZT) ceramic are investigated between room temperature and 300°C. Comparison with a soft PZT shows that acceptor doping has a stronger influence on mechanically induced domain switching than on switching caused by electric fields. A quantitative analysis of spontaneous and remanent strain and polarization indicates that poling in the soft material is dominated by 180° domain processes, while non-180° processes dominate the strain behavior. If the mechanical load exceeds a threshold level, the "hardening" effect of the acceptor doping vanishes, and hard and soft materials behave identically. The results are discussed based on the defect dipole model and the charge drift model for hardening and aging in acceptor-doped ferroelectric ceramics. [source] An Inside View: Professional Judges' and Lay Judges' Support for Mixed TribunalsLAW & POLICY, Issue 2 2003Sanja Kutnjak Ivkovi This paper studies the level of specific and general support for mixed tribunals, a form of lay participation in the government. The analyses focus on the opinions provided by 229 Croatian lay judges and eighty professional judges , the insiders in mixed tribunals. The results indicate that the judge's lay or professional role in the criminal justice system and the type of court exhibit stronger influence on the general level of support than any of the variables measuring specific support. Nevertheless, the perceived frequency of lay judges' comments, the most direct measure of members' crucial activity during trials and deliberations among the specific variables included in the models, is significantly related to the respondents' general opinions about mixed tribunals. [source] A metabolomic study of substantial equivalence of field-grown genetically modified wheatPLANT BIOTECHNOLOGY JOURNAL, Issue 4 2006John M. Baker Summary The ,substantial equivalence' of three transgenic wheats expressing additional high-molecular-weight subunit genes and the corresponding parental lines (two lines plus a null transformant) was examined using metabolite profiling of samples grown in replicate field trials on two UK sites (Rothamsted, Hertfordshire and Long Ashton, near Bristol) for 3 years. Multivariate comparison of the proton nuclear magnetic resonance spectra of polar metabolites extracted with deuterated methanol,water showed a stronger influence of site and year than of genotype. Nevertheless, some separation between the transgenic and parental lines was observed, notably between the transgenic line B73-6-1 (which had the highest level of transgene expression) and its parental line L88-6. Comparison of the spectra showed that this separation resulted from increased levels of maltose and/or sucrose in this transgenic line, and that differences in free amino acids were also apparent. More detailed studies of the amino acid composition of material grown in 2000 were carried out using gas chromatography-mass spectrometry. The most noticeable difference was that the samples grown at Rothamsted consistently contained larger amounts of acidic amino acids (glutamic, aspartic) and their amides (glutamine, asparagine). In addition, the related lines, L88-6 and B73-6-1, both contained larger amounts of proline and ,-aminobutyric acid when grown at Long Ashton than at Rothamsted. The results clearly demonstrate that the environment affects the metabolome and that any differences between the control and transgenic lines are generally within the same range as the differences observed between the control lines grown on different sites and in different years. [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] Genetic and environmental influence on language impairment in 4-year-old same-sex and opposite-sex twinsTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 2 2004Essi Viding Background:, We investigated the aetiology of language impairment in 579 four-year-old twins with low language performance and their co-twins, members of 160 MZ twin pairs, 131 same-sex DZ pairs and 102 opposite-sex DZ pairs. Methods:, Language impairment in 4-year-olds was defined by scores below the 15th percentile on a general factor derived from an extensive language test battery. Language impairment of different degrees of severity was investigated by using multiple cut-offs below the 15th percentile. Results:, DeFries,Fulker extremes analysis indicated that language impairment as measured by the general language scale is under strong genetic influence. In addition, group differences heritability showed an increasing trend (from 38% to 76%) as a function of severity of language impairment. Although more boys are impaired than girls, incorporating opposite-sex DZ pairs into the analysis found neither quantitative nor qualitative differences between boys and girls in genetic and environmental aetiologies. Conclusions:, Language impairment at four years is heritable. This finding replicates previous research on language impairment and extends it by showing that language impairment is heritable in twins selected from a representative community sample. Despite the mean difference between boys and girls, genetic and environmental influences are quantitatively and qualitatively similar for language impairment for boys and girls. For both boys and girls, heritability appears to be greater for more severe language impairment, indicating stronger influence of genes at the lower end of language ability. [source] Effect of sublingual medication of sildenafil citrate/ apomorphine on sexual behaviour of male ratsANDROLOGIA, Issue 2 2009X. Huang Summary The study investigated the combined effect of sublingually administered sildenafil (SN) and apomorphine (APO SL) on the sexual behaviour of male rats. Male Sprague,Dawley rats (50) were divided into five groups (10 rats per each group): blank control, sildenafil group and SN plus APO SL high dosage, medium dosage and low dosage group. After sublingual administration of the agents (control and SN plus APO SL) and a sole dosage of sildenafil (stomach irrigation), the rats were mated with female counterparts in pairs, and the latent period of chasing, the frequency of chasing in 60 min, the latent period of mounting and the frequency of mounting in 60 min were recorded. The lower dosage of SN plus APO SL exerted a stronger influence on the sexual activities in male rats than did the higher sole dosage of sildenafil. Identification of common neurochemical and neuroanatomical substrates of sexual responding between animals and humans suggests that the evolution of sexual behaviour has been highly conserved and indicates that animal models of human sexual response can be used successfully as pre-clinical tools. So sublingual medication of SN combined with APO SL may be at least a support inference about male sexual libido. [source] The use of alternative diets to culture juvenile cuttlefish, Sepia officinalis: effects on growth and lipid compositionAQUACULTURE NUTRITION, Issue 3 2010A. FERREIRA Abstract The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), crayfish (Procambarus clarkii) and fish (Sardina pilchardus) and two semi-humid artificial diets (based on fish or shrimp powder) to the cuttlefish, Sepia officinalis, were analysed. Growth rate and feeding rate [FR; % body weight (BW) day,1] and food conversions (FC, %) were determined. Cuttlefish fed shrimp grew larger (3.8% BW day,1) and had the highest FC, followed by those fed crayfish, and sardine. The highest FR was obtained for cuttlefish fed crayfish (10.5% BW day,1). Although both artificial diets were accepted, none produced growth. Digestive gland-to-body weight ratio (DG/BW ratio) was calculated for animals fed each diet. A positive correlation (r = 0.94) between cuttlefish ingestion FR and DG weight was obtained. Mortality occurred mainly during the last week, and some cannibalism occurred among cuttlefish fed artificial diets. Finally, lipid composition of diets, DG and mantle of each group were analysed. Sardine diet was characterized by high levels of triacylglycerol (TG), whereas the main difference between shrimp and crayfish was the higher n -3/n -6 ratio found in shrimp. Changes in the lipid composition of DG were related to diet, but did not correlate with growth data. A strong loss of TG in the DG of artificial diets groups was notable. No differences in mantle lipid composition among the natural diets were found, but artificial diet groups showed higher contents of neutral lipids in their mantle respect to natural diets. According to results obtained, crayfish (P. clarkii) could be used as an alternative prey for rearing S. officinalis compared with shrimp. Artificial diets showed the worst effects in growth and mortality as well as the stronger influence on DG and mantle lipid composition of cuttlefish. [source] Interactive effects of temperature and diet on the growth and biochemical composition of juveniles of the pearl oyster Pinctada mazatlanicaAQUACULTURE RESEARCH, Issue 11 2009Pedro E Saucedo Abstract The combined effects of temperature and diet on the growth and biochemical composition of juveniles of the pearl oyster Pinctada mazatlanica at the hatchery were investigated. Specimens were subjected to a combination of four temperatures (20, 23, 26 and 29 °C) and five microalgal diets (Isochrysis galbana alone, I. galbana+Pavlova salina, I. galbana+Chaetoceros muelleri, C. muelleri+P. salina and I. galbana+P. salina+C. muelleri). An increase in shell height occurred in a linear pattern, while wet weight gain fitted a power law. Temperature, more than diet, exerted a stronger influence on the growth and condition of the specimens. The combination of 29 °C with P. salina+C. muelleri led to the fastest growth in shell height, while the combination of 29 °C with I. galbana+C. muelleri led to the highest wet and dry weight biomass. In contrast, specimens grew significantly less in shell height and wet weight at 20 °C, regardless of the diet. At all temperatures, the monoalgal diet of I. galbana led to the slowest growth of specimens, but in turn favoured the highest levels of protein, carbohydrate and lipid reserves as a possible strategy to store more energy reserves under stressful events. [source] Combined effects of water exchange regimes and calcium carbonate additions on growth and survival of hatchery-reared juvenile spotted babylon (Babylonia areolata Link 1807) in recirculating grow-out systemAQUACULTURE RESEARCH, Issue 7 2006S Kritsanapuntu Abstract To determine a suitable culture environment to maximize growth and survival, the hatchery-reared juvenile spotted babylon, Babylonia areolata, were held in plastic rearing tanks at four calcium carbonate additions of 0, 100 and 300 g tonne,1, and four water exchange regimes of 0-, 15-, 30- and 60-day intervals in a recirculating grow-out system for 120 days. The results clearly showed that growth was greatest between water exchange regimes of 15- and 30-day intervals and all calcium carbonate additions, with water exchange regimes of 0- and 60-day intervals resulting in poor growth. Final survival was highest between water exchange regimes of 15- and 30-day intervals, and all calcium carbonate additions, with water exchange regimes of 0-day intervals and all calcium carbonate additions resulting in high mortalities. This study showed that water exchange regimes had a stronger influence on the growth of juvenile B. areolata than calcium carbonate additions. It is recommended that B. areolata juveniles be maintained within the water exchange regimes range of 15,30-day intervals and at calcium carbonate additions between 0 and 500 g tonne,1, providing optimum conditions for production of this species in a recirculating grow-out system. [source] Differences in benthic cover inside and outside marine protected areas on the Great Barrier Reef: influence of protection or disturbance history?AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 7 2009Monique R. Myers Abstract 1.Marine protected areas (MPAs) are being used increasingly to manage and protect marine resources. Most studies of MPAs have focused on fish. In this study, the influence of MPA protection on coral reef benthic organisms on the Great Barrier Reef (GBR) was investigated. In addition, the interaction between protection and natural disturbance history was examined. 2.Differences in benthic cover inside and outside MPAs were assessed at 15 pairs of Protected and General Use reefs on the GBR using annual monitoring data from the Australian Institute of Marine Science's Long-Term Monitoring Programme (LTMP). At each reef, benthic cover was determined using a benthic video survey at three sites, with each site consisting of five 50,m transect lines separated by at least 250,m running parallel to the reef crest at 6,9,m depth. 3.Benthic cover was related to both protection status and disturbance history, but natural perturbations exerted a stronger influence on benthic cover than did protection status. The influence of natural perturbation was most noticeable for hard coral. 4.Most reefs where no natural disturbance events had occurred (,undisturbed reefs') had higher hard coral cover and lower soft coral cover than General Use reefs. While the high levels of hard coral on Protected reefs may be a result of protection status, it might also have resulted from selection bias that occurred during the initial zoning of the Great Barrier Reef Marine Park (i.e. managers may have given protection status to reefs with high coral cover). 5.These results are likely influenced by the relatively low intensity of human use, both on the Great Barrier Reef in general and at the particular monitoring sites studied. Over time, as local populations and tourism increase, the effect of protection may become more evident at LTMP sites. Copyright © 2009 John Wiley & Sons, Ltd. [source] Fire resilience of ant assemblages in long-unburnt savanna of northern AustraliaAUSTRAL ECOLOGY, Issue 7 2008CATHERINE L. PARR Abstract Tropical savannas and rainforests contrast in their flammability and the fire resilience of their associated species. While savanna species generally exhibit high resilience to burning, there is much debate about the fire resilience of forest-associated species, and the persistence of forest patches in a flammable savanna matrix. Where fire has been excluded, savanna tends on a trajectory towards forest, with an increase in forest-associated plants and animal species. This study tested the idea that given the high proportion of forest-associated taxa in long-unburnt savanna, the fauna of these areas would be expected to exhibit less resilience to fire than the fauna in frequently burnt savannas. The study investigated the immediate and short-term effects on ant assemblages of re-introducing fire into long-unburnt savanna in northern Australia. The ant fauna exhibited high resistance to fires, with no significant short-term change in mean abundance or species richness; instead, seasonality had a far stronger influence on overall ant activity. Fire caused dramatic declines in dominance of the patchily distributed forest-associated species Oecophylla smaragdina and Papyrius sp., but had no effect on overall dominance by open savanna species of Iridomyrmex. Dominance by Iridomyrmex pallidus declined, but this was compensated for by increases in I. reburrus, while two other species of Iridomyrmex showed no change. This indicates a high level of functional redundancy among dominant species of Iridomyrmex, which universally dominate open savanna communities, but not of dominant forest-associated species. Overall, our findings demonstrate a high degree of fire-resilience of the long-unburnt savanna ant fauna. Despite the occurrence of forest-associated species, the high proportion of savanna species persisting in this habitat means that long-unburnt savanna retains the general response characteristics of frequently burnt savanna. [source] ECONOMIC FREEDOM VERSUS POLITICAL FREEDOM: CROSS-COUNTRY INFLUENCES ON CORRUPTION,AUSTRALIAN ECONOMIC PAPERS, Issue 2 2005RAJEEV K. GOEL Using a well-known index of corruption, this paper examines the determinants of corruption for a large sample of countries. Specifically, the present study brings empirical evidence to bear on the question of whether economic freedom or political freedom serves as a deterrent to corrupt activity. In particular, does greater economic freedom or greater political freedom yield a more ,clean' society? Our results show that greater economic freedom seems to matter more in this regard. Examining different components of economic freedom, we find that not all these components are equally effective in reducing corruption. For instance, monetary policy seems to have a stronger influence on the level of corrupt activity in a country than fiscal policy. Robustness of these findings is checked and policy implications are discussed. [source] Parameters Influencing the Release of Tertiary Alcohols from the Surface of "Spherical" Dendrimers and "Linear" Stylomers by Neighbouring-Group-Assisted Hydrolysis of 2-CarbamoylbenzoatesCHEMISTRY - A EUROPEAN JOURNAL, Issue 12 2009Alain Trachsel Abstract Size is not all! Investigation of the controlled release of tertiary alcohols from the surface of dendrimers and "stylomers" as polymer model systems (see scheme) showed that the polarity of the conjugates and structural modifications in close proximity to the release unit have a stronger influence on the rates of hydrolysis than the size (generation) or shape (linear or spherical) of the macromolecules. The influence of structural and physico-chemical parameters on the release of a volatile tertiary alcohol (2-methyl-1-phenyl-2-propanol) by neighbouring-group-assisted cyclisation of 2-carbamoylbenzoates at neutral pH was investigated by comparing the covalent-bond cleavage from the surface of linear, comblike poly(propylene imine) "stylomers" and their corresponding spherical, globular dendrimers. Determination of the kinetic rate constants for the stepwise intramolecular cyclisation of the 2-carbamoylbenzoate moiety by using HPLC showed that the polarity of the conjugates, and thus their solubility in the aqueous reaction medium, has a stronger influence on the rates of hydrolysis than the size (generation) or shape (linear or spherical) of the macromolecules. Furthermore, structural modifications in close proximity to the release unit, such as the presence of functionalities with catalytic activity, have a strong impact on the release efficiency of the active molecules. An understanding of the physico-chemical parameters determining the local environment of the covalent-bond cleavage site is therefore an important prerequisite to transfer the characteristics of small molecules to larger structures such as oligomers and polymers and thus to design efficient macromolecular conjugates for the controlled delivery of bioactive compounds. L'influence des paramètres structurels et physico-chimiques sur le relargage à pH neutre d'un alcool tertiaire volatil (2-méthyl-1-phényl-2-propanol) par cyclisation de 2-carbamoylbenzoates assistée par un groupe voisin a été étudiée. Les ruptures de liaisons covalentes depuis la surface de poly(propylene imines) en forme de peigne ("stylomères") d'une part et de leurs analogues sphériques et globulaires (dendrimères) correspondants d'autre part ont été comparées. La détermination par CLHP des constantes cinétiques pour la cyclisation intramoléculaire des unités 2-carbamoylbenzoate par étapes a montré que la polarité des conjugués, et par conséquent leur solubilité dans le milieu de réaction aqueux, a une influence plus forte sur les vitesses d'hydrolyse que la taille (génération) ou la forme (linéaire ou sphérique) des macromolécules. De plus, des modifications structurelles à proximité immédiate de l'unité de relargage telles que la présence de groupes fonctionnels avec une activité catalytique ont un fort impact sur l'efficacité de relargage des molécules actives. La compréhension des paramètres physico-chimiques qui déterminent l'environnement local du site de rupture de la liaison covalente est par conséquent une condition préalable importante lors du transfert de caractéristiques de petites molécules à des structures plus grandes telles que des oligomères et des polymères, et donc à la conception de conjugués macromoléculaires efficaces pour le relargage contrôlé de composés bioactifs. [source] EFFECTS OF THERMAL AND ELECTROTHERMAL PRETREATMENTS ON HOT AIR DRYING RATE OF VEGETABLE TISSUEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2000WEI-CHI WANG ABSTRACT Cylindrical samples of carrot, potato and yam were dried in a hot-air dehydrator after preheating to 50C or 80C by three different heating methods (conventional, microwave and ohmic). The results showed that enhancement of drying rate increased with pretreatment temperature. Ohmic pretreatment increased the drying rate more than conventional and microwave heating. Desorption isotherms showed that in the low aw range, desorption data of preheated and raw materials were similar. However, the isotherms of preheated samples shifted when aw was high, which indicated that thermal pretreatments altered the structure, and apparently, the water distribution within these materials. For all samples, ohmic pretreatment showed stronger influences on isotherms than microwave heating, while the pretreatment effect of conventional heating was only observed for potato tissue. [source] Spatial and temporal variations in the timing of leaf replacement in a Quercus cornelius-mulleri populationJOURNAL OF VEGETATION SCIENCE, Issue 6 2003Martin L. Cody Nixon & Steele (1981) Abstract. The phenology of spring leaf replacement was studied in a population of 46 evergreen scrub oaks (Quercus cornelius-mulleri) at the edge of the Mojave Desert in each of five years over the period 1990,2001. The oaks occupied a site that spanned rocky slopes to sandy bajadas. The site receives variable annual rainfall (estimated 12-yr average 195 mm; range in study years 67,706 mm). The spatial coordinates of all individuals were recorded, and in April, when leaf replacement was underway, individual replacement phenologies were assessed. Shrub sizes were recorded in three separate years, and in 2001 water potentials were measured. Individuals vary greatly in their timing of leaf replacement within years, and also between years. Many individuals with an early phenology one year are significantly later in the following year, and vice versa. While we detected weak influences on leaf replacement phenology due to shrub size, position within the site, and a genetic component, stronger influences were attributable to the phenology of the shrub in prior years, and to the phenology of neighbours within years. Neighbouring individuals that are close and/or large are significantly disparate in phenology, with one early and the other late. A potential mechanism of local resource depletion associated with costs to an early phenology is discussed. [source] | |||||||||||||||||||||||||||||||