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Strong Implications (strong + implication)
Selected AbstractsTotal population density during the first year of life as a major determinant of lifetime body-length trajectory in marble troutECOLOGY OF FRESHWATER FISH, Issue 4 2008S. Vincenzi Abstract,,, The conditions experienced early in life can strongly influence life-history trajectories in a variety of animal species. Here, we use data from four isolated populations of the endangered stream-dwelling salmonid marble trout (Salmo marmoratus Cuvier 1817) living in the Soca and Idrijca river basins (Slovenia) to explore the influence of the total density experienced during and after the first year of life by marble trout year-classes on body length of marble trout through the lifetime. Analyses were performed by pooling together the stream-specific datasets to cover a wider range of densities. Mean body length of marble trout year-classes through the lifetime (from age 1+ to 5+) was negatively related to total density of marble trout during the first year of life. The relationship between density during the first growth period and body length through the lifetime was well described by negative power curves. Total population density after the first year of life was not correlated with body length, thus suggesting that body growth trajectories are heavily determined early in life. Given size-dependent sexual maturity and egg production in marble trout, the relationship between density early in life and lifetime individual growth may have strong implications in terms of population dynamics and regulation of population size. [source] Developmental changes in the BDNF-induced modulation of inhibitory synaptic transmission in the Kölliker,Fuse nucleus of ratEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2007Miriam Kron Abstract The Kölliker,Fuse nucleus (KF), part of the pontine respiratory group, is involved in the control of respiratory phase duration, and receives both excitatory and inhibitory afferent input from various other brain regions. There is evidence for developmental changes in the modulation of excitatory inputs to the KF by the neurotrophin brain-derived neurotrophic factor (BDNF). In the present study we investigated if BDNF exerts developmental effects on inhibitory synaptic transmission in the KF. Recordings of inhibitory postsynaptic currents (IPSCs) in KF neurons in a pontine slice preparation revealed general developmental changes. Recording of spontaneous and evoked IPSCs (sIPSCs, eIPSCS) revealed that neonatally the ,-aminobutyric acid (GABA)ergic fraction of IPSCs was predominant, while in later developmental stages glycinergic neurotransmission significantly increased. Bath-application of BDNF significantly reduced sIPSC frequency in all developmental stages, while BDNF-mediated modulation on eIPSCs showed developmental differences. The eIPSCs mean amplitude was uniformly and significantly reduced following BDNF application only in neurons from rats younger than postnatal day 10. At later postnatal stages the response pattern became heterogeneous, and both augmentations and reductions of eIPSC amplitudes occurred. All BDNF effects on eIPSCs and sIPSCs were reversed with the tyrosine kinase receptor-B inhibitor K252a. We conclude that developmental changes in inhibitory neurotransmission, including the BDNF-mediated modulation of eIPSCs, relate to the postnatal maturation of the KF. The changes in BDNF-mediated modulation of IPSCs in the KF may have strong implications for developmental changes in synaptic plasticity and the adaptation of the breathing pattern to afferent inputs. [source] Adhesion of Enterococcus faecalis 1131 grown under subinhibitory concentrations of ampicillin and vancomycin to a hydrophilic and a hydrophobic substratumFEMS MICROBIOLOGY LETTERS, Issue 1 2001Amparo M Gallardo-Moreno Abstract The effect of two subinhibitory antibiotic concentrations of ampicillin and vancomycin during growth on the adhesion of Enterococcus faecalis 1131 to glass and silicone rubber was studied in a parallel plate flow chamber. Initial deposition rates and numbers of adhering bacteria after 4 h were higher on hydrophilic glass than on hydrophobic silicone rubber, regardless of growth conditions. The presence of 1/4 minimal inhibitory concentration (MIC) of ampicillin during growth reduced enterococcal adhesion to both substrata, but growth in the presence of 1/4 MIC vancomycin did not affect the adhesion of E. faecalis. Moreover, enterococcal adhesion increased after growth in the presence of 1/8 MIC vancomycin. The increased adhesion after growth in the presence of subinhibitory concentrations of vancomycin may have strong implications for patients living with implanted biomaterials, as they may suffer adverse effects from use of this antibiotic, especially since bacteria once adhered are less sensitive to antibiotics. [source] The impact of co-occurring tree and grassland species on carbon sequestration and potential biofuel productionGCB BIOENERGY, Issue 6 2009RAMESH LAUNGANI Abstract We evaluated how three co-occurring tree and four grassland species influence potentially harvestable biofuel stocks and above- and belowground carbon pools. After 5 years, the tree Pinus strobus had 6.5 times the amount of aboveground harvestable biomass as another tree Quercus ellipsoidalis and 10 times that of the grassland species. P. strobus accrued the largest total plant carbon pool (1375 g C m,2 or 394 g C m,2 yr), while Schizachyrium scoparium accrued the largest total plant carbon pool among the grassland species (421 g C m,2 or 137 g C m,2 yr). Quercus ellipsoidalis accrued 850 g C m,2, Q. macrocarpa 370 g C m,2, Poa pratensis 390 g C m,2, Solidago canadensis 132 g C m,2, and Lespedeza capitata 283 g C m,2. Only P. strobus and Q. ellipsoidalis significantly sequestered carbon during the experiment. Species differed in total ecosystem carbon accumulation from ,21.3 to +169.8 g C m,2 yr compared with the original soil carbon pool. Plant carbon gains with P. strobus were paralleled by a decrease of 16% in soil carbon and a nonsignificant decline of 9% for Q. ellipsoidalis. However, carbon allocation differed among species, with P. strobus allocating most aboveground in a disturbance prone aboveground pool, whereas Q. ellipsoidalis, allocated most carbon in less disturbance sensitive belowground biomass. These differences have strong implications for terrestrial carbon sequestration and potential biofuel production. For P. strobus, aboveground plant carbon harvest for biofuel would result in no net carbon sequestration as declines in soil carbon offset plant carbon gains. Conversely the harvest of Q. ellipsoidalis aboveground biomass would result in net sequestration of carbon belowground due to its high allocation belowground, but would yield lower amounts of aboveground biomass. Our results demonstrate that plant species can differentially impact ecosystem carbon pools and the distribution of carbon above and belowground. [source] A pH-Gating Ionic Transport Nanodevice: Asymmetric Chemical Modification of Single NanochannelsADVANCED MATERIALS, Issue 22 2010Xu Hou Inspired by biological ion channels, the generation of artificial nanochannels has strong implications for the simulation of different processes of ionic transport as well as enhance the functionality of biological ion channels. Here, we show plasma asymmetric chemical modification approach to prepare the pH asymmetric gating nanochannel that can achieve pH control for both different ionic rectification and perfect gating function, simultaneously. [source] Effect of leading edge cut on the aerodynamics of ram-air parachutesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 1 2005R. Balaji Abstract The effect of the configuration of leading edge cut on the aerodynamic performance of ram-air parachutes is studied via two-dimensional flow simulations. The incompressible Reynolds-averaged Navier,Stokes equations, in primitive variables, are solved using a stabilized finite-element formulation. The Baldwin,Lomax model is employed for turbulence closure. Flow past an LS(1) 0417 airfoil is investigated for various configurations of the leading edge cut and results are compared with those from a Clark-Y airfoil section. It is found that the configuration of the leading edge cut affects the lift-to-drag ratio (L/D) of the parachute very significantly. The L/D value has strong implications on the flight performance of the parachute. One particular configuration results in a L/D value that is in excess of 25 at 7.5° angle of attack. Results are presented for other angles of attack for this configuration. Copyright © 2004 John Wiley & Sons, Ltd. [source] Representation and Agenda SettingPOLICY STUDIES JOURNAL, Issue 1 2004Bryan D. Jones We develop a new approach to the study of representation based on agenda setting and attention allocation. We ask the fundamental question: do the policy priorities of the public and of the government correspond across time? To assess the policy priorities of the mass public, we have coded the Most Important Problem data from Gallup polls across the postwar period into the policy content categories developed by the Policy Agendas Project (Baumgartner & Jones, 2002). Congressional priorities were assessed by the proportion of total hearings in a given year focusing on those same policy categories, also from the Agendas Project. We then conducted similar analyses on public laws and most important laws, similarly coded. Finally we analyzed the spatial structure of public and congressional agendas using the Shepard-Kruskal non-metric multidimensional scaling algorithm. Findings may be summarized as follows: First, there is an impressive congruence between the priorities of the public and the priorities of Congress across time. Second, there is substantial evidence of congruence between the priorities of the public and lawmaking in the national government, but the correspondence is attenuated in comparison to agendas. Third, although the priorities of the public and Congress are structurally similar, the location of issues within the structure differs between Congress and the general public. The public "lumps" its evaluation of the nations most important problems into a small number of categories. Congress "splits" issues out, handling multiple issues simultaneously. Finally, the public tends to focus on a very constrained set of issues, but Congress juggles many more issues. The article has strong implications for the study of positional representation as well, because for traditional representation to occur, there must be correspondence between the issue-priorities of the public and the government. We find substantial evidence for such attention congruence here. [source] Decomposing Product Innovativeness and Its Effects on New Product SuccessTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 5 2006Roger J. Calantone Does product innovativeness affect new product success? The current research proposes that the ambiguity in findings may be due to an overly holistic conceptualization of product innovativeness that has erroneously included the concepts of product advantage and customer familiarity. This article illustrates how the same measures have often been used to assess product advantage with product innovativeness and product innovativeness with customer familiarity. These paired overlaps in measurement use are clarified in this research, which decomposes dimensions of product innovativeness along conceptual lines into distinct product innovativeness, product advantage, and customer familiarity constructs. To further support this decomposition, structural equation modeling is used to empirically test the distinctions. The measurement model supports the conceptual separation, and the path model reveals contingent effects of product innovativeness. Although product innovativeness enhances product advantage, a high level of innovativeness reduces customer familiarity, indicating that product innovativeness can be detrimental to new product success if customers are not sufficiently familiar with the nature of the new product and if innovativeness fails to improve product advantage. This exercise in metric development also reveals that after controlling for product advantage and customer familiarity, product innovativeness has no direct effect on new product profitability. This finding has strong implications for firms that mistakenly pursue innovation for its own sake. Consideration of both distribution and technical synergy as driving antecedents demonstrates how firms can still enhance new product success even if an inappropriate level of innovativeness is present. This leads to a simple but powerful two-step approach to bringing highly innovative products to market. First, firms should only emphasize product innovativeness when it relates to the market relevant concepts of product advantage and customer familiarity. Second, existing technical and distribution abilities can be used to enhance product quality and customer understanding. Distribution channels in particular should be exploited to counter customer uncertainty toward newly introduced products. [source] Comparison and Origin of Forest and Grassland Ant Assemblages in the High Plateau of Madagascar (Hymenoptera: Formicidae),BIOTROPICA, Issue 1 2002Brian L. Fisher ABSTRACT We assessed species richness and composition of ant assemblages in adjacent montane forest and secondary (anthropogenic) grassland habitats in the central plateau of Madagascar. We used five quantitative methods (leaf litter sifting, two types of pitfall traps, beating low vegetation, and soil digging) and compared methods within and across habitats. Sample,based and occurrence,based accumulation curves demonstrated that die efficiency of ant inventory methods is habitat specific. Litter sifting, however, was the single most efficient method in both habitats. Overall, our analyses of the relative efficiency of methods recommend the use of sifting and beating in the montane forest site, and sifting alone in the grassland site. In four of five methods, more species were collected in the grassland site (31 spp.) than in the forest site (26 spp.). Occurrence,based accumulation curves based on all methods demonstrated that species richness was similar in the two habitats, reaching a maximum difference of approximately one species. Only five species were shared between the grassland and forest sites. The presence of a high number of ant species restricted to the grassland site (18 spp.) is the first record of high endemism in this habitat in Madagascar and may have strong implications for the reconstruction of the natural vegetation types at the time humans arrived. Their presence suggests that a comparable open habitat, such as montane woodland, shrubland, or thicket, was present on Madagascar long before humans developed the secondary grasslands less than 2000 years ago. These results are contrary to the "classical hypothesis" that the central plateau was a continuous region of closed forest. These results support the hypothesis that the montane regions, including the central plateau, once contained areas of habitat with an open structure and that the endemic ants now found in the secondary grasslands were originally native to such a habitat. RéSUMé La richesse en espéces et la composition des fourmis ont été inventoriées dans la for,t montagneuse du plateau central de Madagascar et dans la prairie secondaire adjacente. Cinq méthodes quantitatives ont été utilisées (tamisage des litières, deux types de trous-pièges, battage des végétations basses et lavage de terre). Nous avons comparé I'efficacité de ces méthodes dans chacun et entre les deux habitats. Les courbes d'accumulation d'espèces basées sur I'échantillon et sur I'occurrence ont montré que I'efficacité des méthodes d'inventaire de fourmis est habitat-dépendant. Cependant, le tamisage des litières se montrait la méthode la plus efficace dans les deux habitats. Nos analyses sur I'efficacité relative des méthodes recommandent I'utilisation combinée du tamisage des litières et du battage de végétation dans la for,t montagneuse, et I'utilisation seule du tamisage des litières dans la prairie secondaire. Dans quatre des cinq méthodes, plus d'espèces ont été collectées dans la prairie (31 spp.) que dans la for,t (26 spp.). Les courbes d'accumulation d'occurrence basées sur routes les méthodes ont démontré que la richesse en espèces de ces deux habitats est similaire, atteignant seulement une difference maximale d'approximativement une espèce. Pourtant, seulement cinq espèces parta-geaient les deux habitats. La présence de plusieurs espèces de fourmis uniquement trouvées dans la prairie (18 spp.) est la première observation d'une forte endémicité de cet habitat et peut avoir une importante implication pour la restauration des types de végétation naturelle initiale de I'ile. Leur présence suggère que des habitats ouverts similaires tels que les formations arbustives de montagnes et les fourrés, étaient présentsà Madagascar longtemps avant la transformation de ces habitats en prairie secondaire par les humains. Ces résultats contredisent I'hypothèse classique qui avance que le plateau central a é té uniquement composé d'une région de for,t dense. Ainsi, ces résultats supportent I'hypothese que la région montagneuse contenant le plateau central, renfermait des habitats àstructure ouverte et que les fourmis endémiques actuellement trouvées dans la prairie secondaire sont, a I'origine natives de ces habitats. [source] | ||||||||||