164 research outputs found
Spatial genetic variation of a riparian wolf spider Pardosa agricola (Thorell, 1856) on lowland river banks: the importance of functional connectivity in linear spatial systems
Introduction: contains Cover, Table of Contents, Letter from the Editor, and Masthead
The Richmond Journal of Law and Technology is proud to present the fourth and final issue of the 2011-2012 academic year. This issue includes a dedication to Professor John Carroll written by Rick Klau, the Journal’s founder
Introduction: contains Cover, Table of Contents, Letter from the Editor, and Masthead
The Richmond Journal of Law and Technology is proud to present its first issue of the 2011-2012 academic year. The Journal strives to discuss new and emerging issues that fall squarely at the intersection of technology and the law. Another year goes by and technology continues to advance, and not surprisingly, further immerses itself into our daily lives. The Journal believes it is our mission to recognize the practical effects the growth of technology has on society and to promote a relevant and timely discussion on these topics
Introduction: contains Cover, Table of Contents, Letter from the Editor, and Masthead
The Richmond Journal of Law and Technology is proud to present its second issue of the 2011-2012 academic year. The Journal strives to discuss new and emerging issues that fall squarely at the intersection of technology and the law. As we enter the new year, we must remain mindful of the ever-growing role that technology plays in our daily lives. In that vein, the Journal believes it is our mission to promote a relevant and timely discussion on technology-related legal issues
The effects of flooding disturbance on the distribution and behaviour of riparian arthropods along a lowland gravel river
This Ph.D.-thesis aimed to address which environmental factors influence the assemblage structure of mobile, riparian arthropods along spatially structured river banks of a rain-fed, lowland gravel river, the Common Meuse. As riverine ecosystems are basically non-equilibrium, dynamic ecosystems, mainly flow regimes and flood pulse characteristics are expected to shape both the distribution and behaviour of its inhabitants. The river banks along the Common Meuse are (in)frequently disturbed by flood events and liable to extreme microclimatological conditions. Hence, functional life-history traits of the present species, particularly spiders (Araneae) and carabid beetles (Carabidae), supposedly affect species composition as well. Moreover, organisms occurring within a highly structured system and which are repeatedly exposed to flooding disturbance, are expected to have evolved or adjusted their behavioural responses in accordance with their functional life-history characteristics such as habitat affinity and mobility. Correspondingly, less mobile species are expected to show variation in their spatial genetic structure as well.
Based on an intensive pitfall survey, increased anthropogenic alterations of water discharges were shown to cause the loss of stenotopic, xerothermophilic and less mobile riparian arthropods. Next to it, the results of two field experiments indicated that movement decisions of two sympatric wolf spiders (Lycosidae) were guided, particularly, by factors related to their population of origin (side of the river; either genetics or experience). A stenotopic riparian wolf spider, however, relied more on individual information (e.g. visual signals) and showed a higher degree of behavioural plasticity. This might increase the beneficiality of flood-avoiding behaviour. By using Amplified Fragment Length Polymorphism (AFLP) markers, the genetic population structure of the highly stenotopic wolf spider Pardosa agricola (Thorell, 1856) was studied. Nearby populations were less differentiated genetically than populations on different sides of the river, indicating the importance of functional connectivity along the riparian corridor.
River restoration and the rehabilitation of the riparian corridor should generate the required heterogeneity at the river bank level, hence increasing the sustainability of dynamic lowland river systems and realizing the conservation of vulnerable riparian arthropods. River management should consider the management of the alluvial hinterland as well to provide suitable refuges during flooding
Boomkikker en kamsalamander in Vlaanderen : eindelijk van de ondergang gered?
Boomkikker en kamsalamander komen omwille van hun Europese bescherming regelmatig onder de aandacht. Er worden al geruime tijd inspanningen gedaan om deze soorten te beschermen, maar die waren niet altijd even succesvol. Het is pas sinds 2007 dat er dankzij de inzet van vrijwilligers met grootschalige acties en gericht beheer successen worden geboekt. Anno 2018 worden eindelijk nieuwe soortbeschermingsprogramma’s (SBP’s) voor beide soorten in Vlaanderen opgemaakt. Het moment bij uitstek om een overzicht te geven van hoe het beide de afgelopen jaren verging, en welke initiatieven echt het verschil hebben gemaakt, met aandacht voor wat zeker niet mag ontbreken in de nieuwe SBP’s
Relaciones culturales filipino-persas (I): las Rubaiyat de Manuel Bernabé
Life history trade-offs are a key notion in evolutionary biology, notably for understanding how selection shapes the diversity of traits among species. Despite the frequent study of such trade-offs, few studies synchronously investigate the effects of multiple factors, such as niche specialization and adaptation to harsh environments. We compared reproduction (fecundity and egg quality) in two sympatric couples (one habitat generalist and one specialist) of congeneric wolf spider species, in both Arctic and temperate habitats. We found that specialist species at both latitudes invested more in clutch size than did generalist species. We interpret this result as an optimization of clutch production. In the Arctic, the specialist was able to invest in fecundity with increasing body size at a much higher rate than the generalist species. In the temperate habitat, both species showed similar strategies: they increased quantity and quality of offspring relative to body size at the same rate. These results are consistent with the hypothesis that Arctic species must develop distinct strategies in order not to overlap each other’s ecological niches as a consequence of limited food resources or niche space. We emphasize the need to test the role of plasticity and environmentally mediated effects of competition on arthropod fitness
Resolving diverse oxygen transport pathways across Sr-doped lanthanum ferrite and metal-perovskite heterostructures
Perovskite structured transition metal oxides are important technological
materials for catalysis and solid oxide fuel cell applications. Their
functionality often depends on oxygen diffusivity and mobility through complex
oxide heterostructures, which can be significantly impacted by structural and
chemical modifications, such as doping. Further, when utilized within
electrochemical cells, interfacial reactions with other components (e.g. Ni-
and Cr-based alloy electrodes and interconnects) can influence the perovskite's
reactivity and ion transport, leading to complex dependencies that are
difficult to control in real-world environments. Here we use isotopic tracers
and atom probe tomography to directly visualize oxygen diffusion and transport
pathways across perovskite and metal-perovskite heterostructures, i.e. (Ni-Cr
coated) Sr-doped lanthanum ferrite (LSFO). Annealing in 18O2(g) results in
elemental and isotopic redistributions through oxygen exchange (OE) in the LSFO
while Ni-Cr undergoes oxidation via multiple mechanisms and transport pathways.
Complementary density functional theory (DFT) calculations at experimental
conditions provide rationale for OE reaction mechanisms and reveal a complex
interplay of different thermodynamic and kinetic drivers. Our results shed
light on the fundamental coupling of defects and oxygen transport in an
important class of catalytic materials.Comment: 39 pages, 10 figure
Dispersal capacity shapes responses of river island invertebrate assemblages to vegetation structure, island area, and flooding
1. Riparian invertebrate communities occupy a dynamic ecotone where hydrogeomorphological (e.g. river flows) and ecological (e.g. succession) processes may govern assemblage structure by filtering species according to their traits (e.g. dispersal capacity, niche).
2. We surveyed terrestrial invertebrate assemblages (millipedes, carabid beetles, spiders) in 28 river islands across four river catchments over two years. We predicted that distinct ecological niches would produce taxon-specific responses of abundance and species richness to: i) disturbance from episodic floods, ii) island area, iii) island vegetation structure and iv) landscape structure. We also predicted that responses would differ according to species’ dispersal ability (aerial vs terrestrial only), indicating migration was sustaining community structure.
3. Invertebrate abundance and richness was affected by different combinations of vegetation structure, island area and flood disturbance according to species’ dispersal capacity. Carabid abundance related negatively to episodic floods, particularly for flightless species, but the other taxa were insensitive to this disturbance. Larger islands supported greater abundance of carabids and all invertebrates able to disperse aerially. Vegetation structure, particularly tree canopy density and plant richness, related positively to invertebrate abundance across all taxa and aerial dispersers, whereas terrestrial disperser richness related positively to tree cover. Landscape structure did not influence richness or abundance.
4. Multiple ecological processes govern riparian invertebrate assemblages. Overall insensitivity to flood disturbance and responses contingent on dispersal mode imply that spatial dynamics subsidize the communities through immigration. Particular habitat features (e.g. trees, speciose vegetation) may provide refuges from disturbance and concentration of niches and food resources
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