These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Life history strategy influences parasite responses to habitat fragmentation.  

PubMed

Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission. PMID:23954434

Froeschke, Götz; van der Mescht, Luther; McGeoch, Melodie; Matthee, Sonja

2013-12-01

2

RESEARCH ARTICLE Habitat heterogeneity and life-history traits influence  

E-print Network

traits that facilitate a remnant population strategy, such as dormant seeds (e.g., pin cherry, Prunus pensylvanica) or long-life span and competition avoidance (e.g., emergent pioneer species such as tulip poplar

Turner, Monica G.

3

Host Life History Strategy, Species Diversity, and Habitat Influence Trypanosoma cruzi Vector Infection in Changing Landscapes  

PubMed Central

Background Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. Methodology/Principal Findings R. pallescens vectors (N?=?643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site. Conclusions/Significance In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially by changing host community structure to favor hosts that are short-lived with high reproductive rates. Study results apply to potential environmental management strategies for Chagas disease. PMID:23166846

Gottdenker, Nicole L.; Chaves, Luis Fernando; Calzada, José E.; Saldaña, Azael; Carroll, C. Ronald

2012-01-01

4

Concurrent habitat and life history influences on effective/census population size ratios in stream-dwelling trout.  

PubMed

Lower effective sizes (N(e)) than census sizes (N) are routinely documented in natural populations, but knowledge of how multiple factors interact to lower N(e)/N ratios is often limited. We show how combined habitat and life-history influences drive a 2.4- to 6.1-fold difference in N(e)/N ratios between two pristine brook trout (Salvelinus fontinalis) populations occupying streams separated by only 750 m. Local habitat features, particularly drainage area and stream depth, govern trout biomass produced in each stream. They also generate higher trout densities in the shallower stream by favoring smaller body size and earlier age-at-maturity. The combination of higher densities and reduced breeding site availability in the shallower stream likely leads to more competition among breeding trout, which results in greater variance in individual reproductive success and a greater reduction in N(e) relative to N. A similar disparity between juvenile or adult densities and breeding habitat availability is reported for other species and hence may also result in divergent N(e)/N ratios elsewhere. These divergent N(e)/N ratios between adjacent populations are also an instructive reminder for species conservation programs that genetic and demographic parameters may differ dramatically within species. PMID:22822435

Belmar-Lucero, Sebastian; Wood, Jacquelyn L A; Scott, Sherylyne; Harbicht, Andrew B; Hutchings, Jeffrey A; Fraser, Dylan J

2012-03-01

5

Concurrent habitat and life history influences on effective/census population size ratios in stream-dwelling trout  

PubMed Central

Lower effective sizes (Ne) than census sizes (N) are routinely documented in natural populations, but knowledge of how multiple factors interact to lower Ne/N ratios is often limited. We show how combined habitat and life-history influences drive a 2.4- to 6.1-fold difference in Ne/N ratios between two pristine brook trout (Salvelinus fontinalis) populations occupying streams separated by only 750 m. Local habitat features, particularly drainage area and stream depth, govern trout biomass produced in each stream. They also generate higher trout densities in the shallower stream by favoring smaller body size and earlier age-at-maturity. The combination of higher densities and reduced breeding site availability in the shallower stream likely leads to more competition among breeding trout, which results in greater variance in individual reproductive success and a greater reduction in Ne relative to N. A similar disparity between juvenile or adult densities and breeding habitat availability is reported for other species and hence may also result in divergent Ne/N ratios elsewhere. These divergent Ne/N ratios between adjacent populations are also an instructive reminder for species conservation programs that genetic and demographic parameters may differ dramatically within species. PMID:22822435

Belmar-Lucero, Sebastian; Wood, Jacquelyn L A; Scott, Sherylyne; Harbicht, Andrew B; Hutchings, Jeffrey A; Fraser, Dylan J

2012-01-01

6

Influence of habitat degradation on fish replenishment  

NASA Astrophysics Data System (ADS)

Temperature-induced coral bleaching is a major threat to the biodiversity of coral reef ecosystems. While reductions in species diversity and abundance of fish communities have been documented following coral bleaching, the mechanisms that underlie these changes are poorly understood. The present study examined the impacts of coral bleaching on the early life-history processes of coral reef fishes. Daily monitoring of fish settlement patterns found that ten times as many fish settled to healthy coral than sub-lethally bleached coral. Species diversity of settling fishes was least on bleached coral and greatest on dead coral, with healthy coral having intermediate levels of diversity. Laboratory experiments using light-trap caught juveniles showed that different damselfish species chose among healthy, bleached and dead coral habitats using different combinations of visual and olfactory cues. The live coral specialist, Pomacentrus moluccensis, preferred live coral and avoided bleached and dead coral, using mostly visual cues to inform their habitat choice. The habitat generalist, Pomacentrus amboinensis, also preferred live coral and avoided bleached and dead coral but selected these habitats using both visual and olfactory cues. Trials with another habitat generalist, Dischistodus sp., suggested that vision played a significant role. A 20 days field experiment that manipulated densities of P. moluccensis on healthy and bleached coral heads found an influence of fish density on juvenile weight and growth, but no significant influence of habitat quality. These results suggests that coral bleaching will affect settlement patterns and species distributions by influencing the visual and olfactory cues that reef fish larvae use to make settlement choices. Furthermore, increased fish density within the remaining healthy coral habitats could play an important role in influencing population dynamics.

McCormick, M. I.; Moore, J. A. Y.; Munday, P. L.

2010-09-01

7

Architecture and life support systems for a rotating space habitat  

NASA Astrophysics Data System (ADS)

Life Support Systems are critical to sustain human habitation of space over long time periods. As orbiting space habitats become operational in the future, support systems such as atmo-sphere, food, water etc. will play a very pivotal role in sustaining life. To design a long-duration space habitat, it's important to consider the full gamut of human experience of the environment. Long-term viability depends on much more than just the structural or life support efficiency. A space habitat isn't just a machine; it's a life experience. To be viable, it needs to keep the inhabitants satisfied with their condition. This paper provides conceptual research on several key factors that influence the growth and sustainability of humans in a space habitat. Apart from the main life support system parameters, the architecture (both interior and exterior) of the habitat will play a crucial role in influencing the liveability in the space habitat. In order to ensure the best possible liveability for the inhabitants, a truncated (half cut) torus is proposed as the shape of the habitat. This structure rotating at an optimum rpm will en-sure 1g pseudo gravity to the inhabitants. The truncated torus design has several advantages over other proposed shapes such as a cylinder or a sphere. The design provides minimal grav-ity variation (delta g) in the living area, since its flat outer pole ensures a constant gravity. The design is superior in economy of structural and atmospheric mass. Interior architecture of the habitat addresses the total built environment, drawing from diverse disciplines includ-ing physiology, psychology, and sociology. Furthermore, factors such as line of sight, natural sunlight and overhead clearance have been discussed in the interior architecture. Substantial radiation shielding is also required in order to prevent harmful cosmic radiations and solar flares from causing damage to inhabitants. Regolith shielding of 10 tons per meter square is proposed for the habitat. In order to ensure Thermal control of the habitat, multiple radiators on the exterior and a thermal shield on the inner circumference of the habitat are proposed. Food production on-board the habitat is proposed to be facilitated through vertical farming systems. These multi-storey farming systems are known to be more efficient in terms of area and sustainable than conventional farms. Agriculture on-board these farms are proposed to be facilitated through hydroponics and enriched regolith. Apart from food production, these farms can cater to fish farming as means of food, animal and insect breeding. In order to ensure waste treatment of organic matter, a biogas plant is proposed in the habitat which can be used to generate electrical or mechanical power .An optimum atmospheric pressure of 51.1Kpa is proposed for the habitat comprising of Oxygen and Helium. Recreational facilities although not directly related to life support systems, play a very important role in optimum liveability of inhabitants. Open spaces, sports facilities, micro gravity swimming pools, orbital hotels are proposed as modes of recreation to ensure long term sustainability for the inhabitants.

Misra, Gaurav

8

Comparative phylogeography of two sister (congeneric) species of cardiid bivalve: Strong influence of habitat, life history and post-glacial history  

NASA Astrophysics Data System (ADS)

Sister (congeneric) species may exhibit disparate patterns of biogeographic genetic structures due to different life histories and habitat preferences. The common cockle Cerastoderma edule and the lagoon cockle Cerastoderma glaucum probably diverged from their common ancestor in the present territory of Sahara around 5 million years ago. Although it is difficult to separate both species morphologically, various genetic markers, both mitochondrial and nuclear, clearly distinguish them. Furthermore, their lifestyles are different, as C. edule has a much less fragmented coastal habitat and a longer duration of pelagic larval stage than C. glaucum. A comparative genetic analysis was conducted on 17 populations of C. edule and 13 populations of C. glaucum using a 506 bp fragment of mitochondrial DNA (COI). We tested the hypothesis that differences in habitat types and life history are reflected in the genetic structure patterns of these two cockles. Indeed substantial differences in population genetic structures between them are revealed. Genetic diversity within C. glaucum populations decreases northwards as a consequence of post-glacial (re)colonization from southern refugia, while C. edule displays an opposite pattern indicating survival in glacial refuges in the northern Atlantic. Among populations within geographic groups, genetic differentiation is low in C. edule, probably as a result of larval dispersal with coastal currents, while it is extremely high in C. glaucum, best explained by the fragmented habitats. Interestingly, long distance divergence is less expressed in C. glaucum than in C. edule, which supports the speculation that migrating birds (frequently observed in lagoons) may occasionally transport the former more often or more efficiently than the latter. The approach applied in this study (e.g., rarefaction procedure, selection of samples of both species from the same regions) enabled a new and reliable comparative analysis of the existing raw datasets.

Tarnowska, Katarzyna; Krakau, Manuela; Jacobsen, Sabine; Wo?owicz, Maciej; Féral, Jean-Pierre; Chenuil, Anne

2012-07-01

9

An Analysis of Hybrid Life Support Systems for Sustainable Habitats  

E-print Network

The design of sustainable habitats on Earth, on other planetary surfaces, and in space, has motivated strategic planning with respect to life support (LS) system technology development and habitat design. Such planning ...

Shaw, Margaret Miller

2014-01-01

10

Architecture and life support systems for a rotating space habitat  

Microsoft Academic Search

Life Support Systems are critical to sustain human habitation of space over long time periods. As orbiting space habitats become operational in the future, support systems such as atmo-sphere, food, water etc. will play a very pivotal role in sustaining life. To design a long-duration space habitat, it's important to consider the full gamut of human experience of the environment.

Gaurav Misra

2010-01-01

11

Habitat filtering across tree life stages in tropical forest communities  

PubMed Central

Tropical tree communities are shaped by local-scale habitat heterogeneity in the form of topographic and edaphic variation, but the life-history stage at which habitat associations develop remains poorly understood. This is due, in part, to the fact that previous studies have not accounted for the widely disparate sample sizes (number of stems) that result when trees are divided into size classes. We demonstrate that the observed habitat structuring of a community is directly related to the number of individuals in the community. We then compare the relative importance of habitat heterogeneity to tree community structure for saplings, juveniles and adult trees within seven large (24–50 ha) tropical forest dynamics plots while controlling for sample size. Changes in habitat structuring through tree life stages were small and inconsistent among life stages and study sites. Where found, these differences were an order of magnitude smaller than the findings of previous studies that did not control for sample size. Moreover, community structure and composition were very similar among tree sub-communities of different life stages. We conclude that the structure of these tropical tree communities is established by the time trees are large enough to be included in the census (1 cm diameter at breast height), which indicates that habitat filtering occurs during earlier life stages. PMID:23843384

Baldeck, C. A.; Harms, K. E.; Yavitt, J. B.; John, R.; Turner, B. L.; Valencia, R.; Navarrete, H.; Bunyavejchewin, S.; Kiratiprayoon, S.; Yaacob, A.; Supardi, M. N. N.; Davies, S. J.; Hubbell, S. P.; Chuyong, G. B.; Kenfack, D.; Thomas, D. W.; Dalling, J. W.

2013-01-01

12

Linking habitat structure to life history strategy: Insights from a Mediterranean killifish  

NASA Astrophysics Data System (ADS)

Modern theories of life history evolution deal with finding links between environmental factors, demographic structure of animal populations and the optimal life history strategy. Small-sized teleost fish, occurring in fragmented populations under contrasting environments, have been widely used as study models to investigate these issues. In the present study, the Mediterranean killifish Aphanius fasciatus was used to investigate the relationships between some habitat features and life history strategy. We selected four sites in the Venice lagoon inhabited by this species, exhibiting different combinations of two factors: overall adult mortality, related to intertidal water coverage and a consequent higher level of predator exposure, and the level of sediment organic matter, as indicator of habitat trophic richness. Results showed that these were the two most important factors influencing demography and life history traits in the four sites. Fish from salt marshes with high predator pressure were smaller and produced a higher number of eggs, whereas bigger fish and a lower reproductive investment were found in the two closed, not tidally influenced habitats. Habitat richness was positively related with population density, but negatively related with growth rate. In particular the synergy between high resources and low predation level was found to be important in shaping peculiar life history traits. Results were discussed in the light of the interactions between selective demographic forces acting differentially on age/size classes, such as predation, and habitat trophic richness that may represent an important energetic constraint on life history traits. The importance to link habitat productivity and morphology to demographic factors for a better understanding of the evolution of life history strategy under contrasting environments was finally suggested.

Cavraro, Francesco; Daouti, Irini; Leonardos, Ioannis; Torricelli, Patrizia; Malavasi, Stefano

2014-01-01

13

Key life history strategies and relationship to habitat Chuck Peven  

E-print Network

Key life history strategies and relationship to habitat Chuck Peven Peven Consulting, Inc as swimming performance, temperature tolerance, and direction of migration (e.g., sockeye fry) all have been traits may not reflect genetic adaptations (i.e., that increase fitness), managers should ensure

14

Habitat configuration and availability influences the settlement of temperate reef fishes (Tripterygiidae)  

E-print Network

Habitat configuration and availability influences the settlement of temperate reef fishes Habitat availability Habitat configuration Settlement Tripterygiidae To survive, most benthic marine organisms must find suitable settlement habitat. For reef fishes, settlement hab- itat is often structurally

Shima, Jeff

15

Artificial structures influence fouling on habitat-forming kelps.  

PubMed

The addition of artificial structures along urbanised shorelines is a global phenomenon. Such modifications of habitats have important consequences to the abundance of fouling organisms on primary substrata, but the influence on fouling of habitat-formers living on these structures is poorly understood. Fouling of habitat-forming kelps Ecklonia radiata on pier-pilings was compared to that on rocky reefs at three locations in Sydney Harbour. Kelps on pilings supported different assemblages of bryozoans from those on reefs. The abundances of bryozoans on kelps, in particular of the non-indigenous species Membranipora membranacea, were significantly greater on pilings. Differences were consistent in time and space. This indicates that the addition of artificial structures also affects fouling on secondary biogenic substrata, altering biodiversity and potentially facilitating the introduction and dispersal of non-indigenous epibiota. Understanding the processes that cause these patterns is necessary to allow sensible predictions about ecological effects of built structures. PMID:22452393

Marzinelli, Ezequiel M

2012-01-01

16

Habitat use and ontogenetic shifts of fish life stages at rocky reefs in South-western Mediterranean Sea  

NASA Astrophysics Data System (ADS)

The present study aimed at exploring the habitat use by fish life stages and ontogenetic shifts in a South-western Mediterranean rocky reef. The relation with rocky reef habitat structure (complexity, heterogeneity, total cover and depth) was visually surveyed on a monthly basis, in four locations and during one year, for the abundance of young-of-the-year (YOY) and juvenile reef fish. Fish assemblage responded significantly to spatial and temporal variations of structural microhabitat, this response being species-specific. Abundance of fish life stages was directly related to temperature variation, with higher abundances occurring on warmer months. Also, habitat differences occurred between YOY and juveniles of a series of species from shallow steeper rocky habitats to deeper complex rocky bottoms with high total cover. Spatial differences in YOY and juvenile abundance across locations could be attributed to fine-scale habitat preference, from purely rocky, more complex sites, with greater slopes and depths, to sites harbouring more heterogeneous habitats. By characterising the microhabitat association of fish life stages (both YOY and juveniles), and identifying for what species this influence may interfere with spatial and temporal patterns, the present study can be used as a basis for pluriannual monitoring of fish recruitment success in the area in order to better understand their population dynamics.

Félix-Hackradt, F. C.; Hackradt, C. W.; Treviño-Otón, J.; Pérez-Ruzafa, A.; García-Charton, J. A.

2014-04-01

17

Modified Habitats Influence Kelp Epibiota via Direct and Indirect Effects  

PubMed Central

Addition of man-made structures alters abiotic and biotic characteristics of natural habitats, which can influence abundances of biota directly and/or indirectly, by altering the ecology of competitors or predators. Marine epibiota in modified habitats were used to test hypotheses to distinguish between direct and indirect processes. In Sydney Harbour, kelps on pier-pilings supported greater covers of bryozoans, particularly of the non-indigenous species Membranipora membranacea, than found on natural reefs. Pilings influenced these patterns and processes directly due to the provision of shade and indirectly by altering abundances of sea-urchins which, in turn, affected covers of bryozoans. Indirect effects were more important than direct effects. This indicates that artificial structures affect organisms living on secondary substrata in complex ways, altering the biodiversity and indirectly affecting abundances of epibiota. Understanding how these components of habitats affect ecological processes is necessary to allow sensible prediction of the effects of modifying habitats on the ecology of organisms. PMID:21755011

Marzinelli, Ezequiel M.; Underwood, Antony J.; Coleman, Ross A.

2011-01-01

18

Modified habitats influence kelp epibiota via direct and indirect effects.  

PubMed

Addition of man-made structures alters abiotic and biotic characteristics of natural habitats, which can influence abundances of biota directly and/or indirectly, by altering the ecology of competitors or predators. Marine epibiota in modified habitats were used to test hypotheses to distinguish between direct and indirect processes. In Sydney Harbour, kelps on pier-pilings supported greater covers of bryozoans, particularly of the non-indigenous species Membranipora membranacea, than found on natural reefs. Pilings influenced these patterns and processes directly due to the provision of shade and indirectly by altering abundances of sea-urchins which, in turn, affected covers of bryozoans. Indirect effects were more important than direct effects. This indicates that artificial structures affect organisms living on secondary substrata in complex ways, altering the biodiversity and indirectly affecting abundances of epibiota. Understanding how these components of habitats affect ecological processes is necessary to allow sensible prediction of the effects of modifying habitats on the ecology of organisms. PMID:21755011

Marzinelli, Ezequiel M; Underwood, Antony J; Coleman, Ross A

2011-01-01

19

Does maternal oviposition site influence offspring dispersal to suitable habitat?  

PubMed

Orientation and dispersal to suitable habitat affects fitness in many animals, but the factors that govern these behaviors are poorly understood. In many turtle species, hatchlings must orient and disperse to suitable aquatic habitat immediately after emergence from subterranean nests. Thus, the location of nest sites relative to aquatic habitats ideally should be associated with the direction of hatchling dispersal. At our study site, painted turtles (Chrysemys picta) nest to the west (on an island) and east (on the mainland) of a wetland, which determines the direction that hatchlings must travel to reach suitable aquatic habitat. To determine if hatchling orientation is intrinsically influenced by the location where their mothers nest, we employed a two-part cross-fostering experiment in the field, whereby half the eggs laid in mainland nests were swapped with half the eggs laid in island nests. Moreover, because C. picta hatchlings overwinter inside their nests, we performed a second cross-fostering experiment to fully decouple the effects of (1) the maternally chosen nest location, (2) the embryonic developmental location, and (3) the overwinter location. We released hatchlings into a circular arena in the field and found that turtles generally dispersed in a westerly direction, regardless of the maternally chosen nest location and independent of the locations of embryonic development and overwintering. Although this westerly direction was towards suitable aquatic habitat, we could not distinguish whether naïve hatchling turtles (i) use environmental cues/stimuli to orient their movement, or (ii) have an intrinsic bias to orient west in the absence of stimuli. Nevertheless, these findings suggest that the orientation behavior of naïve hatchling turtles during terrestrial dispersal is not dependent upon the location of maternally-chosen nest sites. PMID:23196739

Warner, Daniel A; Mitchell, Timothy S

2013-07-01

20

Underground habitats in the Río Tinto basin: a model for subsurface life habitats on Mars.  

PubMed

A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the Río Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e.g., pO(2), pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO(2), CH(4), and H(2). SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The Río Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores. PMID:19105758

Fernández-Remolar, David C; Prieto-Ballesteros, Olga; Rodríguez, Nuria; Gómez, Felipe; Amils, Ricardo; Gómez-Elvira, Javier; Stoker, Carol R

2008-10-01

21

Human influence on seagrass habitat fragmentation in NW Mediterranean Sea  

NASA Astrophysics Data System (ADS)

Habitat fragmentation in meadows of Posidonia oceanica, the most important and abundant seagrass in the Mediterranean Sea, was investigated at a region-wide spatial scale using a synthetic ecological index, the Patchiness Index (PI). We tested the hypothesis that human impacts are the major factor responsible for habitat fragmentation in P. oceanica meadows contrasting fragmentation of meadows located in "anthropized" areas with that of meadows located in areas with low anthropization and considered as virtually "natural". We also related fragmentation of meadow with the morphodynamic state of the submerged beach (i.e. distinctive types of beach produced by the topography, the wave climate and the sediment composition) in order to investigate the influence of one natural component on the seagrass meadow seascape. Results demonstrated that fragmentation in the P. oceanica meadows is strongly influenced by the human component, being lower in natural meadows than in anthropized ones, and that it is little influenced by the morphodynamic state of the coast. The use of landscape approaches to discriminate natural disturbance from human impacts that affect seagrass meadows is thus recommended for the proper management of coastal zones.

Montefalcone, Monica; Parravicini, Valeriano; Vacchi, Matteo; Albertelli, Giancarlo; Ferrari, Marco; Morri, Carla; Bianchi, Carlo Nike

2010-01-01

22

Influences of Habitat Composition, Plant Phenology, and Population Density on Autumn Indices of Body  

E-print Network

influenced white-tailed deer (Odocoileus virginianus) body condition during the breeding period. We detailed, body condition, body mass, density, fat reserves, habitat, Odocoileus virginianus, reproduction, white

Laval, Université

23

Habitat  

NSDL National Science Digital Library

This video segment from IdahoPTV's D4K explains the 4 basic requirements of a perfect habitat and what a niche is within a habitat. You'll see videos of different animals in their habitats, such as; bear, moose, spiders and mountain goats,

Idaho PTV

2011-09-21

24

Influences of livestock grazing on sage grouse habitat  

Microsoft Academic Search

Livestock grazing has been identified as one factor associated with the widespread decline and degradation of sage grouse (Centrocercus urophasianus) habitat. We identi- fied n= 17 positive and negative impacts of livestock on sage grouse and habitat. Little information is currently available concerning the directs impacts of livestock grazing on sage grouse habitat. Indirect impacts are better understood than direct

L. Beck; Dean L.. Mitchell

2000-01-01

25

Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season.  

PubMed

Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human activity. The specific areas that require this protection may vary across snowy plover life history stages. PMID:23610630

Webber, Alyson F; Heath, Julie A; Fischer, Richard A

2013-04-01

26

North-Polar Martian Cap as Habitat for Elementary Life  

NASA Astrophysics Data System (ADS)

North-polar cap over millenia Atmospheric water in Mars tends currently as for the past millenia to distil onto the polar caps and be buried under dust deposits. Diffusive release from ground-ice (and its excavation in meteorite impacts [1]) replenishes atmospheric water, allowing the gradual build up of polar ice-dust deposits. When sunlit, this warmed and sublimating ice-dust mix has interest as a potential habitat for micro-organisms. Modelling shows precipitable vapour at 10-50?m/yr, varying sensitively with small changes in orbitable obliquity around the present 25° [2]. The modelling applies to a globe with regionally uniform albedo, unlike the steep topography and dark layering of the north polar cap whose upper 300m have accumulated over the last 500 kyr [3]. The cliffs and ravines of the north-polar cap are thought to form through south-facing slopes sublimating and gaining a dirt-encrusted surface, while horizontal surfaces brighten through frost deposits. The two-phase surface derives from the dust and frost feedback on surface albedo [4] and the resulting terrain develops over diurnal cycles of frosting and sublimation, and over annual seasonal cycles. The steep south-facing sides of observed ravines when unshadowed would see for a few hours the full intensity of sunlight at near normal incidence, without the atmospheric dimming at similar inclinations on Earth. As exposed ice sublimates at T > 200K (partial pressure exceeds typical martian 0.1 Pa), a crust of dirt develops to maintain quasi-stability. The dirt crust's main function is to buffer the ice against diurnal temperature fluctuations, but it also slows down vapour diffusion - analogous to south polar ice sublimation [5] and the growth of ground-ice [6]. We envisage 1-10 mm/yr as the net sublimation rate, compatible with the 100 kyr life and scales of the north polar ravines. Modelling of icy-dirt crusts in the polar cap Plane-parallel layers have been used to model the changing temperature through the dirt-encrusted ice cliff [7]. Thermal conduction through the dirt crust limits sublimation of underlying ice. This allows use of the thermal wave solution: where the thermal diffusivity ? combining conductivity and specific heat is taken constant and ?0 = 1.88 yr is the martian year. As in [6] we adopt a sinusoidal temperature variation and take ? = 0.0001 m²/hour. Like the martian ground ice case, the transition from dirt to ice is quite sharp. The surface temperature variation at the polar cap determined from local radiative balance is largely determined by albedo, while sublimation losses from a south-facing cliff are concentrated in the summer months. For fresh frost, the albedo is close to unity but values 0.6-0.8 allow for varying amounts of exposed dirt or dust, as explored in Figure 1. This shows the integrated ice loss over one martian year (687 Earth days) using the thermal wave solution and the Clausius-Clapeyron equation for ice sublimation: for T in degrees Kelvin. The solutions in Fig. 1 indicate a 10-15cm dirt crust develops quite quickly, within a few decades, becoming thick enough to choke back the sublimation rate to under 1mm/yr, compatible with the age of the cliffs. Less steep slopes develop rather thinner crusts. The seasonal thermal wave of Equ.1 applies for depths exceeding ~5cm (two diurnal skin depths). For A of 0.6, Fig. 1 shows a 10 cm thick crust builds up in ~30yr; this thick a crust may plausibly be maintained against weathering processes. If A<0.5, the mean temperature is too high for thermal inertia alone to choke the sublimation; the crust thickens to >10 cm within a few years and the self-sealing (deposition) and flow-retarding (adsorption/desorption) properties become significant in the thicker and hotter crust [5]. For A>0.7, a 5 cm crust cuts the sublimation rate to <0.1 mm/yr - we expect frost deposition to dominate, keeping the surface icy with high albedo for most of the diurnal cycle. The thermal lag due to latent heat needs including for realistic modeling of the dirt-ice crust. Thus

Wallis, M. K.; Wickramasinghe, J. T.; Wickramasinghe, N. C.

2008-09-01

27

Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2010  

SciTech Connect

This report describes the 2010 research conducted under the U.S. Army Corps of Engineers (USACE) project EST-P-09-1, titled Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, and known as the 'Salmon Benefits' study. The primary goal of the study is to establish scientific methods to quantify habitat restoration benefits to listed salmon and trout in the lower Columbia River and estuary (LCRE) in three required areas: habitat connectivity, early life history diversity, and survival (Figure ES.1). The general study approach was to first evaluate the state of the science regarding the ability to quantify benefits to listed salmon and trout from habitat restoration actions in the LCRE in the 2009 project year, and then, if feasible, in subsequent project years to develop quantitative indices of habitat connectivity, early life history diversity, and survival. Based on the 2009 literature review, the following definitions are used in this study. Habitat connectivity is defined as a landscape descriptor concerning the ability of organisms to move among habitat patches, including the spatial arrangement of habitats (structural connectivity) and how the perception and behavior of salmon affect the potential for movement among habitats (functional connectivity). Life history is defined as the combination of traits exhibited by an organism throughout its life cycle, and for the purposes of this investigation, a life history strategy refers to the body size and temporal patterns of estuarine usage exhibited by migrating juvenile salmon. Survival is defined as the probability of fish remaining alive over a defined amount of space and/or time. The objectives of the 4-year study are as follows: (1) develop and test a quantitative index of juvenile salmon habitat connectivity in the LCRE incorporating structural, functional, and hydrologic components; (2) develop and test a quantitative index of the early life history diversity of juvenile salmon in the LCRE; (3) assess and, if feasible, develop and test a quantitative index of the survival benefits of tidal wetland habitat restoration (hydrologic reconnection) in the LCRE; and (4) synthesize the results of investigations into the indices for habitat connectivity, early life history diversity, and survival benefits.

Diefenderfer, Heida L.; Johnson, Gary E.; Sather, Nichole K.; Skalski, J. R.; Dawley, Earl M.; Coleman, Andre M.; Ostrand, Kenneth G.; Hanson, Kyle C.; Woodruff, Dana L.; Donley, Erin E.; Ke, Yinghai; Buenau, Kate E.; Bryson, Amanda J.; Townsend, Richard L.

2011-10-01

28

Local habitat and landscape influence predation of bird nests1 on afforested Mediterranean cropland2  

E-print Network

1 Local habitat and landscape influence predation of bird nests1 on afforested Mediterranean-mail: josem.rey@uah.es10 11 #12; 2 ABSTRACT12 Afforestation programs such as the one promoted by the EU these14 afforestations may cause severe damage to open habitat species, especially birds of high15

Carrascal, Luis M.

29

Food Availability and Tiger Shark Predation Risk Influence Bottlenose Dolphin Habitat Use  

Microsoft Academic Search

Although both food availability and predation risk have been hypothesized to affect dolphin habitat use and group size, no study has measured both factors concurrently to determine their relative influences. From 1997 to 1999, we investigated the effect of food availability and tiger shark (Galeocerdo cuvier) predation risk on bottlenose dolphin (Tursiops aduncus) habitat use and group size in Shark

Michael R. Heithaus; Lawrence M. Dill

2002-01-01

30

Influence of Mowing Artemisia tridentata ssp. wyomingensis on Winter Habitat for Wildlife  

Microsoft Academic Search

Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter habitat for wildlife is lacking. This information is crucial because many wildlife species depended on

Kirk W. Davies; Jonathan D. Bates; Dustin D. Johnson; Aleta M. Nafus

2009-01-01

31

Influence of matrix habitats on the occurrence of insectivorous bird species in Amazonian forest fragments  

Microsoft Academic Search

The influence of matrix habitats on the occurrence of seven understory insectivorous bird species in forest fragments was examined at the Biological Dynamics of Forest Fragments Project, Manaus, Amazonia. Playback techniques were used to detect individuals in the continuous primary forest, fragments of 1, 10 and 100 ha, and in two matrix habitats of secondary forest dominated by Vismia spp.

Marina Antongiovanni; Jean Paul Metzger

2005-01-01

32

Vocal and Visual Conspecific Cues Influence the Behavior of Chimney Swifts at Provisioned Habitat  

Microsoft Academic Search

Numerous species use socially derived information from conspecifics to evaluate the quality of potential habitat. We examine whether conspecific cues influence Chimney Swift (Chaetura pelagica) behavior at uninhabited provisioned habitat, and whether their response in the pre- and post-breeding seasons differs. We used conspecific playbacks and decoys at 19 towers designed for the swift's nesting in southern Ontario, Canada, and

Leah Finity; Joseph J. Nocera

2012-01-01

33

Salmon Life Histories, Habitats, and Food Webs in the Columbia River Estuary  

E-print Network

Salmon Life Histories, Habitats, and Food Webs in the Columbia River Estuary Daniel J. Bottom NOAA management efforts in the Columbia River estuary on behalf of salmon: (1) the estuary is irrelevant to conservation because fresh water conditions limit salmon production; and (2) the estuary is a threat

34

INVERTEBRATE PRODUCTIVITY IN A SUBTROPICAL BLACKWATER RIVER: THE IMPORTANCE OF HABITAT AND LIFE HISTORY  

Microsoft Academic Search

Habitat and life history are critical elements in assessing the production dynamics of invertebrates and their role in aquatic ecosystems. We studied invertebrate productivity at two sites in a subtropical blackwater river (the Satilla) in the Lower Coastal Plain of Georgia, USA, and found that submerged wooden substrates, or snags, are heavily colonized by aquatic insects. We compared invertebrate productivity

ARTHUR C. BENKE; THOMAS C. VAN; DAVID M. GILLESPIE; FRED K. PARRISH

1984-01-01

35

Life?History Variation in Contrasting Habitats: Flowering Decisions in a Clonal Perennial Herb ( Veratrum album )  

Microsoft Academic Search

Quantifying intraspecific demographic variation pro- vides a powerful tool for exploring the diversity and evolution of life histories. We investigate how habitat-specific demographic variation and the production of multiple offspring types affect the population dynamics and evolution of delayed reproduction in a clonal perennial herb with monocarpic ramets (white hellebore). In this species, flow- ering ramets produce both seeds and

Elze Hesse; Mark Rees

2008-01-01

36

Fluorine-Rich Planetary Environments as Possible Habitats for Life  

PubMed Central

In polar aprotic organic solvents, fluorine might be an element of choice for life that uses selected fluorinated building blocks as monomers of choice for self-assembling of its catalytic polymers. Organofluorine compounds are extremely rare in the chemistry of life as we know it. Biomolecules, when fluorinated such as peptides or proteins, exhibit a “fluorous effect”, i.e., they are fluorophilic (neither hydrophilic nor lipophilic). Such polymers, capable of creating self-sorting assemblies, resist denaturation by organic solvents by exclusion of fluorocarbon side chains from the organic phase. Fluorous cores consist of a compact interior, which is shielded from the surrounding solvent. Thus, we can anticipate that fluorine-containing “teflon”-like or “non-sticking” building blocks might be monomers of choice for the synthesis of organized polymeric structures in fluorine-rich planetary environments. Although no fluorine-rich planetary environment is known, theoretical considerations might help us to define chemistries that might support life in such environments. For example, one scenario is that all molecular oxygen may be used up by oxidation reactions on a planetary surface and fluorine gas could be released from F-rich magma later in the history of a planetary body to result in a fluorine-rich planetary environment. PMID:25370378

Budisa, Nediljko; Kubyshkin, Vladimir; Schulze-Makuch, Dirk

2014-01-01

37

Habitat heterogeneity influences restoration efficacy: Implications of a habitat-specific management regime for an invaded marsh  

NASA Astrophysics Data System (ADS)

Invasive species have to be managed to prevent adverse consequences. Spartina alterniflora has invaded many marshes where salinity and inundation are often key factors affecting vegetation. The former was surface clipped twice and native Phragmites australis was planted in invaded zones to examine the effects of habitat properties on the efficacy of invader control and native restoration. The results showed that two clipping treatments almost eliminated S. alterniflora in the zones with long inundation periods of 80 h/15 d but stimulated compensatory growth of S. alterniflora in the zones with short inundation periods. Transplanted P. australis performed better over time in zones with low salinity (<10.5 psu) but performed poorly in high-salinity zones, indicating that the efficacy of invader management and native restoration activities changes significantly along habitat gradients. With a progression from the dyke to the seaward side of the studied marsh, there was a long then short then long inundation period whereas salinity increased consistently. The study indicates that the high-frequency removal of the above-ground parts of S. alterniflora should be used only in the middle tidal zones and that native vegetation should be planted in zones above the mean high water level while the others zones in the saltmarsh should be restored to mud flats. Usually, invasive plants can flourish in highly heterogeneous habitats, which can influence management efficacy by influencing the re-growth of treated invaders and the performance of restored native species. Therefore, habitat-specific management regimes for invasive species can be expected to be more efficient because of their dependence on specific habitats.

Tang, Long; Gao, Yang; Wang, Cheng-Huan; Li, Bo; Chen, Jia-Kuan; Zhao, Bin

2013-07-01

38

Comparative life history of female mosquito fish, Gambusia affinis , in tidal freshwater and oligohaline habitats  

Microsoft Academic Search

Synopsis  Female Gambusia affinis were collected from low salinity\\/near-neutral pH and tidal freshwater\\/low pH localities to document life history variation\\u000a between these two habitats. Mosquito fish were 2.7 times more abundant in low salinity\\/near-neutral pH (2.37 ± 0.72 ppt; pH\\u000a = 5.73 ± 0.11) than in tidal freshwater\\/low pH (0.27 ± 0.19 ppt; pH = 4.46 ± 0.18) habitats in Old

Nancy Brown-Peterson; Mark S. Peterson

1990-01-01

39

The relative influence of habitat amount and configuration on genetic structure across multiple spatial scales  

PubMed Central

Despite strong interest in understanding how habitat spatial structure shapes the genetics of populations, the relative importance of habitat amount and configuration for patterns of genetic differentiation remains largely unexplored in empirical systems. In this study, we evaluate the relative influence of, and interactions among, the amount of habitat and aspects of its spatial configuration on genetic differentiation in the pitcher plant midge, Metriocnemus knabi. Larvae of this species are found exclusively within the water-filled leaves of pitcher plants (Sarracenia purpurea) in a system that is naturally patchy at multiple spatial scales (i.e., leaf, plant, cluster, peatland). Using generalized linear mixed models and multimodel inference, we estimated effects of the amount of habitat, patch size, interpatch distance, and patch isolation, measured at different spatial scales, on genetic differentiation (FST) among larval samples from leaves within plants, plants within clusters, and clusters within peatlands. Among leaves and plants, genetic differentiation appears to be driven by female oviposition behaviors and is influenced by habitat isolation at a broad (peatland) scale. Among clusters, gene flow is spatially restricted and aspects of both the amount of habitat and configuration at the focal scale are important, as is their interaction. Our results suggest that both habitat amount and configuration can be important determinants of genetic structure and that their relative influence is scale dependent. PMID:25628865

Millette, Katie L; Keyghobadi, Nusha

2015-01-01

40

Influence of grazing management on population attributes, habitats, and habitat selection of bobwhites in south Texas  

E-print Network

Selection of Bobwhites in South Texas (May 1987) Robert Neal Wilkins, B. S. , Stephen F. Austin State University Chairman of Advisory Committee: Dr. Wendell G. Swank The short-term effects that short duration grazing (SDG) and two-pasture deferred... and quail selected habitats were more closely aligned on the SDG than on the 2PDG during the "nesting/brooding season" (summer 1985) and "covey season". DEDICATION To Sandra. ACKNOWLEDGEMENTS My chairman, Dr. Wendell G. Swank, had the rare ability...

Wilkins, Robert Neal

1987-01-01

41

Habitat and distribution of post-recruit life stages of the squid Loligo forbesii  

NASA Astrophysics Data System (ADS)

This study models habitat preferences of the squid Loligo forbesii through its post-recruitment life cycle in waters around Scotland (UK). Trawl survey and market sample data from 1985 to 2004 are used to model seasonal habitats of immature, maturing and mature squid (maturity being inferred from size and season). Squid presence-absence and catch rate in areas of presence were analysed using generalised additive models, relating spatiotemporal patterns of distribution and abundance to ecogeographic variables. For all maturity classes, higher abundance in winter and spring (i.e., quarters 1 and 2) was associated with deeper water while higher abundance in summer and autumn (quarters 3 and 4) was associated with shallower water, consistent with seasonal onshore-offshore migrations but suggesting that most spawning may take place in deeper waters. The preferred SST range was generally 8-8.75 °C while preferred salinity values were below 35‰ in winter and summer and above 35‰ in spring and autumn. Squid were positively associated with gravel substrate and negatively associated with mud. Seasonal changes in habitat use were more clearly evident than changes related to inferred maturity, although the two effects cannot be fully separated due to the annual life cycle. Habitat selection for this species can be satisfactorily modelled on a seasonal basis; predictions based on such models could be useful for fishers to target the species more effectively, and could assist managers wishing to protect spawning grounds. The extent to which this approach may be useful for other cephalopods is discussed.

Smith, Jennifer M.; Macleod, Colin D.; Valavanis, Vasilis; Hastie, Lee; Valinassab, Tooraj; Bailey, Nick; Santos, M. Begoña; Pierce, Graham J.

2013-10-01

42

Shifting the life-history paradigm: discovery of novel habitat use by hawksbill turtles  

PubMed Central

Adult hawksbill turtles (Eretmochelys imbricata) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species. Our findings highlight the variability in life-history strategies that marine turtles and other wide-ranging marine wildlife may exhibit among ocean regions, and the importance of understanding such disparities from an ecological and management perspective. PMID:21880620

Gaos, Alexander R.; Lewison, Rebecca L.; Yañez, Ingrid L.; Wallace, Bryan P.; Liles, Michael J.; Nichols, Wallace J.; Baquero, Andres; Hasbún, Carlos R.; Vasquez, Mauricio; Urteaga, José; Seminoff, Jeffrey A.

2012-01-01

43

Accessible habitat for shorebirds: Factors influencing its availability and conservation implications  

USGS Publications Warehouse

We examined the relationship between water levels and accessible habitat, and how accessible habitat influenced Dunlin (Calidris alpina) and Semipalmated Sandpiper (Calidris pusilla) numbers in managed wetlands at Pea Island (North Carolina) and Merritt Island (Florida) National Wildlife Refuges in 1998 and 1999. At Pea Island we experimentally manipulated water levels, which also allowed us to examine the effects of water level fluctuations on prey base. We examined these relationships because access to foraging habitat by shorebirds is positively related to the length of their tarsometatarsus, and in the southeastern United States, small calidrids are a numerically important component of the two million migrants using inland and managed wetlands. We confirmed the importance of shallow waters for Dunlin and Semipalmated Sandpiper-numbers increased with increasing availability of 0-4 cm habitat. At Merritt Island, Dunlin use was inversely related to variability in water depth of 0-4 cm. Minimizing the frequency and amplitude of water level fluctuations associated with single-capped culverts is necessary to improve habitat quality. After adjusting for accessibility, spring habitat requirements for Dunlin and Semipalmated Sandpiper at Pea Island were met under nearly all abundance scenarios. We identified water level targets that maximize accessible habitat at Pea Island. In contrast, winter habitat requirements for Dunlin at Merritt Island were not met except in one scenario. Seasonally low prey density contributed to the shortfall, suggesting that allocating more habitat is the primary management option. Manipulating water levels at Pea Island did not adversely affect the density of eight shorebird prey species. Estimates of accessible habitat and other parameters (e.g., turnover rates, prey biomass) are essential to set and implement realistic shorebird habitat conservation goals.

Collazo, J.A.; O'Harra, D. A.; Kelly, C.A.

2002-01-01

44

Influence of landscape elements on population densities and habitat use of three small-mammal species.  

SciTech Connect

Mabry, K.E., E.A. Dreelin, and G.W. Barrett. 2003. Influence of landscape elements on population densities and habitat use of three small-mammal species. J. Mammology. 84(1):20-25. Corridor effects on population densities and habitat use of 3 small mammal species were assessed in an experimentally fragmented landscape. Corridor presence did not have a statistically significant effect on population densities of cotton rats or cotton mice; however, a significant effect was observed for old-field mice. The results suggest that landscape fragmentation and habitat structure may have varying effects on population densities of different species.

Mabry, Karen, E.; Dreelin, Erin, A.; Barrett, Gary, W.

2003-01-01

45

Does rock disturbance by superb lyrebirds (Menura novaehollandiae) influence habitat selection by juvenile snakes?  

Microsoft Academic Search

Ver tebrates that destroy or disturb habitats used by other animals may influence habitat selection by sympatric taxa. In south-east Australian forests, superb lyrebirds (Menura novaehollandiae) displace soil, leaf litter and rocks during their daily foraging activities. We investigated whether superb lyrebirds disturb small sandstone rocks that endangered broad-headed snakes Hoplocephalus bungaroides and common small-eyed snakes Cryptophis nigrescens use as

JONATHAN K. WEBB; MARTIN J. WHITING

2006-01-01

46

Influence of Mowing Artemisia tridentata ssp. wyomingensis on Winter Habitat for Wildlife  

Microsoft Academic Search

Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production\\u000a for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter\\u000a habitat for wildlife is lacking. This information is crucial because many wildlife species depended on

Kirk W. Davies; Jonathan D. Bates; Dustin D. Johnson; Aleta M. Nafus

2009-01-01

47

Searching for microbial life remotely: Satellite-to-rover habitat mapping in the Atacama Desert, Chile  

NASA Astrophysics Data System (ADS)

The Atacama Desert, one of the most arid landscapes on Earth, serves as an analog for the dry conditions on Mars and as a test bed in the search for life on other planets. During the Life in the Atacama (LITA) 2004 field experiment, satellite imagery and ground-based rover data were used in concert with a `follow-the-water' exploration strategy to target regions of biological interest in two (1 coastal, 1 inland) desert study sites. Within these regions, environments were located, studied and mapped with spectroscopic and fluorescence imaging (FI) for habitats and microbial life. Habitats included aqueous sedimentary deposits (e.g., evaporites), igneous materials (e.g., basalt, ash deposits), rock outcrops, drainage channels and basins, and alluvial fans. Positive biological signatures (chlorophyll, DNA, protein) were detected at 81% of the 21 locales surveyed with the FI during the long-range, autonomous traverses totaling 30 km. FI sensitivity in detecting microbial life in extreme deserts explains the high percentage of positives despite the low actual abundance of heterotrophic soil bacteria in coastal (<1-104 CFU/g-soil) and interior (<1-102 CFU/g-soil) desert soils. Remote habitat, microbial and climate observations agreed well with ground-truth, indicating a drier and less microbially rich interior compared to the relatively wetter and abundant biology of the coastal site where rover sensors detected the presence of fog and abundant surface lichens. LITA project results underscore the importance of an explicit focus by all engineering and science disciplines on microbially relevant scales (mm to nm), and highlight the success of satellite-based and `follow-the-water' strategies for locating diverse habitats of biological promise and detecting the microbial hotspots within them.

Warren-Rhodes, K.; Weinstein, S.; Dohm, J.; Piatek, J.; Minkley, E.; Hock, A.; Cockell, C.; Pane, D.; Ernst, L. A.; Fisher, G.; Emani, S.; Waggoner, A. S.; Cabrol, N. A.; Wettergreen, D. S.; Apostolopoulos, D.; Coppin, P.; Grin, E.; Diaz, Chong; Moersch, J.; Oril, G. G.; Smith, T.; Stubbs, K.; Thomas, G.; Wagner, M.; Wyatt, M.

2007-12-01

48

The alien flora of Greece: taxonomy, life traits and habitat preferences  

Microsoft Academic Search

The aim of the paper is the state-of-the-art assessment of the alien flora of Greece and its traits. The dataset consists\\u000a of a total of 343 alien taxa, including 49 archaeophytes. The taxonomy, life traits and habitat of the 294 neophytes are analysed\\u000a vs their naturalisation status. Out of the 122 (41%) naturalised neophytes, 50 are identified as exhibiting invasive

Margarita Arianoutsou; Ioannis Bazos; Pinelopi Delipetrou; Yannis Kokkoris

2010-01-01

49

Influences of fluctuating flows on spawning habitat and recruitment success  

NASA Astrophysics Data System (ADS)

Over the 50 years of daily peak power generation, no ramping restrictions, and loss of gravel due to operations of Philpott Dam, on Smith River, has created a wider, rectangular-shaped channel, with steeper banks. The pattern caused by channel degradation, tributary headcutting, bank erosion, and downstream aggradation has limited the length of productive habitat to between 3 and 10 river kilometers from the dam. Here the channel appears to contain key habitats where we found the highest redd densities, abundance, and spawner biomass for brown trout (Salmo trutta). Recruitment of brown trout to the fishable size classes is constrained by the daily hydropower peaking operations. The number of young brown trout produced each year was strongly related to the average magnitude of the peak flow and the duration of generation flows. Magnitude of peak flows also depressed abundance of native fishes. Although, brown trout actively removed fine sediment via redd construction and spawning, thereby increasing gravel permeability, the fine sediments from tributaries and bank erosion rapidly intruded into the spawning gravel in downstream reaches of the river. We recommend mitigating the effects of fluctuating releases from Philpott Dam through a combination of flow management and habitat improvement.

Orth, D. J.; Krause, C. W.; Novinger, D. C.

2005-05-01

50

Evaluating the Influence of Geomorphic Conditions on Instream Fish Habitat Using Hydraulic Modeling and Geostatistical Analyses  

NASA Astrophysics Data System (ADS)

A two-dimensional hydrodynamic model (River2D) was utilized to evaluate the relationship between geomorphic conditions (as estimated using an existing rapid assessment protocol) and instream habitat quality in small Vermont streams. Six stream reaches ranging in geomorphic condition from good to poor according to the protocols were utilized for this study. We conducted detailed topographic surveys, quantified bed substrate, and measured velocity and discharge values during baseflow conditions. The reach models were calibrated with realistic roughness values based on field observations and pebble counts. After calibration, the weighted usable area (WUA) of habitat was calculated for each stream at three flows (7Q 10, median, and bankfull) using modeled parameters and habitat suitability curves for specific fish species and life stage. Brown trout (Salmo trutta), white sucker (Catostomus commersoni), and common shiner (Notropis cornutus) habitats were predicted using habitat parameters of velocity, depth, and channel substrate type for adult, juvenile, and fry stages. The predictions of reach-averaged WUA show a negative correlation to the geomorphic condition scores, indicating that the often-used rapid protocols, may not directly relate to habitat conditions at the reach spatial scale. However, the areas of high WUA are distributed in a patchy nature throughout the stream. This fluctuation of physical habitat conditions may be more important to classifying habitat than a single reach-averaged WUA score. The spatial distribution of habitat variables is not captured using either the reach-averaged WUA or geomorphic assessment scores to classify streams. Spatial analyses will be used to further evaluate the patchy nature of WUA distributions, and actual data on species distributions in the study streams will be compared to modeled habitat parameters and their spatial patterns.

Clark, J. S.; Rizzo, D. M.; Hession, W. C.; Watzin, M. C.; Laible, J. P.

2006-05-01

51

Systematic review of the influence of foraging habitat on red-cockaded woodpecker reproductive success.  

SciTech Connect

Relationships between foraging habitat and reproductive success provide compelling evidence of the contribution of specific vegetative features to foraging habitat quality, a potentially limiting factor for many animal populations. For example, foraging habitat quality likely will gain importance in the recovery of the threatened red-cockaded woodpecker Picoides borealis (RCW) in the USA as immediate nesting constraints are mitigated. Several researchers have characterized resource selection by foraging RCWs, but emerging research linking reproductive success (e.g. clutch size, nestling and fledgling production, and group size) and foraging habitat features has yet to be synthesized. Therefore, we reviewed peer-refereed scientific literature and technical resources (e.g. books, symposia proceedings, and technical reports) that examined RCW foraging ecology, foraging habitat, or demography to evaluate evidence for effects of the key foraging habitat features described in the species’ recovery plan on group reproductive success. Fitness-based habitat models suggest foraging habitat with low to intermediate pine Pinus spp. densities, presence of large and old pines, minimal midstory development, and herbaceous groundcover support more productive RCW groups. However, the relationships between some foraging habitat features and RCW reproductive success are not well supported by empirical data. In addition, few regression models account for > 30% of variation in reproductive success, and unstandardized multiple and simple linear regression coefficient estimates typically range from -0.100 to 0.100, suggesting ancillary variables and perhaps indirect mechanisms influence reproductive success. These findings suggest additional research is needed to address uncertainty in relationships between foraging habitat features and RCW reproductive success and in the mechanisms underlying those relationships.

Garabedian, James E. [North Carolina State University

2014-04-01

52

Influence of habitat amount, arrangement, and use on population trend estimates of male Kirtland's warblers  

USGS Publications Warehouse

Kirtland's warblers (Dendroica kirtlandii) persist in a naturally patchy environment of young, regenerating jack pine forests (i.e., 5-23 years old) created after wildfires and human logging activities. We examined how changing landscape structure from 26 years of forest management and wildfire disturbances influenced population size and spatial dispersion of male Kirtland's warblers within their restricted breeding range in northern Lower Michigan, USA. The male Kirtland's warbler population was six times larger in 2004 (1,322) compared to 1979 (205); the change was nonlinear with 1987 and 1994 identified as significant points of change. In 1987, the population trend began increasing after a slowly declining trend prior to 1987, and the rate of increase appeared to slow after 1994. Total amount of suitable habitat and the relative area of wildfire-regenerated habitat were the most important factors explaining population trend. Suitable habitat increased 149% primarily due to increasing plantations from forest management. The relative amount and location of wildfire-regenerated habitat modified the distribution of males among various habitat types, and the spatial variation in their abundance across the primary breeding range. These findings indicate that the Kirtland's warbler male population shifted its use of habitat types temporally and spatially as the population increased and as the relative availability of habitats changed through time. We demonstrate that researchers and managers need to consider not only habitat quality, but the temporal and the spatial context of habitat availability and population levels when making habitat restoration decisions. ?? 2008 Springer Science+Business Media B.V.

Donner, D.M.; Probst, J.R.; Ribic, C.A.

2008-01-01

53

Effects of habitat structure and risk of cannibalism on life-history traits of red swamp crayfish (Procambarus clarki)  

NASA Astrophysics Data System (ADS)

The effects of habitat structure on predator-prey interactions and intra-guild predation have been well studied in a number of ecological and laboratory systems. How intraspecific interactions among members of cannibalistic species are affected by habitat structure has received less attention. We measured the impacts of habitat structure on interspecific aggression, cannibalism, and life-history traits of Procambarus clarki. Crayfish were randomly assigned to structured or simple habitats. Structured habitats consisted of aquaria with four ceramic fire bricks each with three circular holes for shelter; simple habitats lacked shelters. We hypothesized that habitat structure would lead to decreased injury frequency, increased molting frequency, greater survival, and higher reproductive output in crayfish. Reproductive output did not differ between treatments, but juvenile survival was higher in the structured habitat. Molting was more frequent in the structured habitat. In sharp contrast to predictions, survival was lower in the structured habitat. We concluded the increased mortality in the structured habitat was due to the high degree of exposure to cannibalism and aggression among the crayfish immediately following molting.

McCabe, D.; Fradette, K. J.; Usowski, A. E.

2005-05-01

54

Robotic ecological mapping: Habitats and the search for life in the Atacama Desert  

NASA Astrophysics Data System (ADS)

As part of the three-year `Life in the Atacama' (LITA) project, plant and microbial abundance were mapped within three sites in the Atacama Desert, Chile, using an automated robotic rover. On-board fluorescence imaging of six biological signatures (e.g., chlorophyll, DNA, proteins) was used to assess abundance, based on a percent positive sample rating system and standardized robotic ecological transects. The percent positive rating system scored each sample based on the measured signal strength (0 for no signal to 2 for strong signal) for each biological signature relative to the total rating possible. The 2005 field experiment results show that percent positive ratings varied significantly across Site D (coastal site with fog), with patchy zones of high abundance correlated with orbital and microscale habitat types (heaved surface crust and gravel bars); alluvial fan habitats generally had lower abundance. Non-random multi-scale biological patchiness also characterized interior desert Sites E and F, with relatively high abundance associated with (paleo)aqueous habitats such as playas. Localized variables, including topography, played an important, albeit complex, role in microbial spatial distribution. Site D biosignature trends correlated with culturable soil bacteria, with MPN ranging from 10-1000 CFU/g-soil, and chlorophyll ratings accurately mapped lichen/moss abundance (Site D) and higher plant (Site F) distributions. Climate also affected biological patchiness, with significant correlation shown between abundance and (rover) air relative humidity, while lichen patterns were linked to the presence of fog. Rover biological mapping results across sites parallel longitudinal W-E wet/dry/wet Atacama climate trends. Overall, the study highlights the success of targeting of aqueous-associated habitats identifiable from orbital geology and mineralogy. The LITA experience also suggests the terrestrial study of life and its distribution, particularly the fields of landscape ecology and ecohydrology, hold critical lessons for the search for life on other planets. Their applications to robotic sampling strategies on Mars should be further exploited.

Warren-Rhodes, K.; Weinstein, S.; Piatek, J. L.; Dohm, J.; Hock, A.; Minkley, E.; Pane, D.; Ernst, L. A.; Fisher, G.; Emani, S.; Waggoner, A. S.; Cabrol, N. A.; Wettergreen, D. S.; Grin, E.; Coppin, P.; Diaz, Chong; Moersch, J.; Oril, G. G.; Smith, T.; Stubbs, K.; Thomas, G.; Wagner, M.; Wyatt, M.; Boyle, L. Ng

2007-12-01

55

Life-history variation in contrasting habitats: flowering decisions in a clonal perennial herb (Veratrum album).  

PubMed

Quantifying intraspecific demographic variation provides a powerful tool for exploring the diversity and evolution of life histories. We investigate how habitat-specific demographic variation and the production of multiple offspring types affect the population dynamics and evolution of delayed reproduction in a clonal perennial herb with monocarpic ramets (white hellebore). In this species, flowering ramets produce both seeds and asexual offspring. Data on ramet demography are used to parameterize integral projection models, which allow the effects of habitat-specific demographic variation and reproductive mode on population dynamics to be quantified. We then use the evolutionarily stable strategy (ESS) approach to predict the flowering strategy-the relationship between flowering probability and size. This approach is extended to allow offspring types to have different demographies and density-dependent responses. Our results demonstrate that the evolutionarily stable flowering strategies differ substantially among habitats and are in excellent agreement with the observed strategies. Reproductive mode, however, has little effect on the ESSs. Using analytical approximations, we show that flowering decisions are predominantly determined by the asymptotic size of individuals rather than variation in survival or size-fecundity relationships. We conclude that habitat is an important aspect of the selective environment and a significant factor in predicting the ESSs. PMID:18817459

Hesse, Elze; Rees, Mark; Müller-Schärer, Heinz

2008-11-01

56

Short-Term Influence of Tank Tracks on Vegetation and Microphytic Crusts in Shrubsteppe Habitat  

PubMed

/ I examined vegetation and microphytic crust cover on two sites in burned and two sites in unburned big sagebrush (Artemisia tridentata Nutt.) habitat within the Idaho Army National Guard Orchard Training Area in southwestern Idaho. The purpose of this study was to determine the short-term (1-2 years) influence of tank tracks on vegetation and microphytic crusts in shrubsteppe habitat. The two types of tank tracks studied were divots (area where one track has been stopped or slowed to make a sharp turn) and straight-line tracks. Divots generally had a stronger influence on vegetation and microphytic crusts than did straight-line tracks. Tank tracks increased cover of bare ground, litter, and exotic annuals, and reduced cover of vegetation, perennial native grasses, sagebrush, and microphytic crusts. Increased bare ground and reduced cover of vegetation and microphytic crusts caused by tank tracks increase the potential for soil erosion and may reduce ecosystem productivity. Reduced sagebrush cover caused by tank tracks may reduce habitat quality for rodents. Tank tracks may also facilitate the invasion of exotic annuals into sagebrush habitat, increasing the potential for wildfire and subsequent habitat degradation. Thus, creation of divots and movement through sagebrush habitat by tanks should be minimized.KEY WORDS: Divots; Fire history; Idaho; Military; Sagebrush; Straight-line tracks PMID:9582396

Watts

1998-07-01

57

Potential Habitats For Life On Mars: Lessons From The Early Archean  

NASA Astrophysics Data System (ADS)

The Hadean/Early Archaean Earth was characterised by generally submerged protocontinents on a water-covered planet. The supracrustal rocks deposited on top of the protocontinents from the Early Archaean terrains of Barberton (S. Africa) and the Pilbara (Australia) contain evidence of widespread distributions of fossil bacterial biofilms in almost all the habitats available. These include shallow -water, intertidal (saline), and possibly subaerial environments. There is extensive evidence of hydrothermal activity with associated mats in all habitats. We can thus infer that by 3.4-3.5 b.y. ago, terrestrial organisms probably represented chemolithotrophs, heterotrophs and anaerobic photosynthesisers exhibiting thermophilic, acidophilic (possibly alkalophilic?), or halophyilic attributes. The presence of a unifying body of water on Earth could have been an important aid to microbial dispersal between habitats. The geological evolution of Mars, on the other hand, precludes the formation of oceans and (proto)continents, even though there is evidence for significant liquid water at the surface of the planet during the Noachian and early Hesperion, with intermittent appearances during the later Hesperion and Amazonian. How does this important difference in the geological evolution of the two planets affect the possibility of life on Mars? In fact, since the ingredients for life (water, organics and an energy source) were all present on early Mars, and since microorganisms are purely surface-specific, the major geological differences present no inhibition to the appearance of life. Potential habitats include: hot spring, shallow -water, intertidal (saline/alkaline?), subaerial and subsurface environments; potential types of organisms would be chemolithotrophs, heterotrophs and (anaerobic?) photosynthesisers with thermophilic, mesophilic (later on psychrophilic?), acidophilic (alkalophilic?), or halophilic attributes. However, subsequent evolution during the Noachian would have been restricted to isolated habitats since there was no unifying body of water to aid dispersal. With the loss of surficial volatiles, it is possible that the environmental extremes afflicting potential early Martian microbes could have spurred more rapid and diverse evolution compared to evolution on Earth ­ or it could have produced the opposite effect, even killing it off altogether.

Westall, F.; Brack, A.

58

Breeding in high-elevation habitat results in shift to slower life-history strategy within a single species.  

PubMed

1. Elevational gradients create environmental variation that is hypothesized to promote variation in life-history strategies. We tested whether differences in life-history strategies were associated with elevation in a songbird, the dark-eyed junco (Junco hyemalis; Aves; A.O.U. 1998). 2. We monitored birds in four replicated sites per elevation, at 2000 m a.s.l. (high elevation) and 1000 m a.s.l. (low elevation), in the Rocky Mountains of Canada. 3. Over 5 years, we measured the following traits and vital rates: egg-laying schedules, morphological indicators of reproductive stage, seasonal reproductive success, indicators of competitive class (age, size, arrival time), and survival rates. 4. We found two main patterns: with an increase in breeding elevation, dark-eyed juncos delayed the development of structures necessary for reproduction (e.g. cloacal protuberance in males) and reduced the duration of their reproductive period to less than half of the time used by low-elevation birds; and 5. Juncos at high-elevation sites had 55-61% lower annual reproductive success and 15 to 20% higher survival rates. While adult juncos at high elevations produced fewer offspring, those offspring were in better condition. Proportions of age and size classes in high- compared to low-elevation populations were similar, suggesting that a life-history trade-off is present, rather than competition forcing inferior competitors to breed in a peripheral habitat. The apparent trade-off between reproduction and survival corresponded to a shorter period of favourable weather and available food in high- compared to low-elevation habitats. 6. Thus, elevation had a strong influence on life-history characteristics of a single species over a short spatial distance, suggesting a shift in life history from a high reproductive strategy at lower elevations to a high survivor strategy at high elevations. 7. This is the first paper to show a shift in avian life-history strategies along an elevational gradient (in both genders, of multiple age classes) when region (latitude) and phylogenetic histories are controlled for. PMID:19007385

Bears, H; Martin, K; White, G C

2009-03-01

59

Influence of plumage colour on prey response: does habitat alter heron crypsis to prey?  

E-print Network

Influence of plumage colour on prey response: does habitat alter heron crypsis to prey? M. CLAY of crypsis to aquatic prey. White plumage has been hypothesized to be adaptive for herons hunting in open; Caldwell 1986; Tickell 2003). One hypothesis suggests that white plumage may result in in- creased crypsis

Green, Clay - Department of Biology, Texas State University

60

Influence of plumage colour on prey response: does habitat alter heron crypsis to prey?  

Microsoft Academic Search

The foraging strategies of wading birds may be influenced by their degree of crypsis to aquatic prey. White plumage has been hypothesized to be adaptive for herons hunting in open water habitats. We tested this hypothesis with laboratory and field experiments with multiple prey species. We investigated the response of crayfish, Procambarus spp., and mosquitofish, Gambusia affinis, to white- and

M. Clay Green; Paul L. Leberg

2005-01-01

61

INFLUENCE OF FRESHWATER INPUT ON THE HABITAT VALUE OF OYSTER REEFS IN THREE SOUTHWEST FLORIDA ESTUARIES.  

EPA Science Inventory

In order to examine the influence of freshwater input on the habitat value of oyster reefs, a spatiotemporal comparison of reef-resident fishes and decapod crustaceans was conducted during three seasonally dry and three seasonally wet months in three Southwest Florida estuaries: ...

62

Habitat surrounding patch reefs influences the diet and nutrition of the western rock lobster  

EPA Science Inventory

In this study the influence of habitat on the diet and nutrition of a common reef-associated generalist consumer, the western rock lobster Panulirus cygnus, was tested. Stable isotopes (13C/12C and 15N/14N) and gut contents were used to assess the diet of lobsters collected from ...

63

Swamp rabbits in floodplain ecosystems: Influence of landscape- and stand-level habitat on relative abundance  

Microsoft Academic Search

Swamp rabbits (Sylvilagus aquaticus) are bottomland hardwood forest specialists that may serve as useful indicators of ecosystem health. However, no studies\\u000a have assessed the influence of both microhabitat and macrohabitat variables on relative abundance of swamp rabbits. To address\\u000a this gap in the literature, we assessed the influence of landscape- and stand-level habitat variables on relative abundance\\u000a of swamp rabbits

Paul D. Scharine; Clayton K. Nielsen; Eric M. Schauber; Lyann Rubert

2009-01-01

64

Tektite 2 habitability research program: Day-to-day life in the habitat  

NASA Technical Reports Server (NTRS)

Because it is widely agreed that the field of environmental psychology is quite young, it was determined that a sample of recorded observations from a representative mission should be included in the report on Tektite to give the professional reader a better feeling of normal day-to-day life in the isolated habitat. Names of the crew members have been replaced with numbers and some off-color words have been replaced by more acceptable slang; some remarks have been omitted that might lead to easy identification of the subjects. Otherwise, the following pages are exactly as transcribed during the late afternoons and the evenings of the mission.

Nowlis, D. P.

1972-01-01

65

TOPP AS A MARINE LIFE OBSERVATORY: USING ELECTRONIC TAGS TO MONITOR THE MOVEMENTS, BEHAVIOUR AND HABITATS OF MARINE VERTEBRATES  

Microsoft Academic Search

The Tagging of Pacific Pelagic (TOPP) a field program of the Census of Marine Life has proven the concept of using electronic tags to develop a Marine Life Observatory (MLO) to monitor the habitat utilization, movement patterns and behaviour of large marine predators. Given the difficulty of observing the behavior of highly pelagic marine species we know relatively little about

66

Habitat differentiation in the early life stages of simultaneously mass-spawning corals  

NASA Astrophysics Data System (ADS)

The settlement process of coral larvae following simultaneous mass-spawning remains poorly understood, particularly in terms of population and community parameters. Here, the larval settlement patterns of Acropora corals, which are the most diverse genera of scleractinian corals at the species (haplotype) level, were investigated within a single subtropical reef. Across a 4-year period (2007-2010), the mitochondrial and nuclear molecular markers of 1,073 larval settlers were analyzed. Of the 11 dominant haplotypes of recruited populations, nine exhibited non-random patterns of settlement distribution. This result suggests that the actual habitat segregation starts during the early swimming larval stages of their life history, rather than by natural selection after random settlement. In addition, the presence of a depth-related settlement pattern supports that species-specific vertical zonation of coral larvae may play a role in the establishment of habitat segregation. Moreover, in some species that showed a preference toward the shoreward area of the bay, the settlement pattern was consistent with that of the adult distribution. This result indicates that the gametes were not mixed between fore and back reefs in the period from fertilization to settlement during the mass-spawning event, even within a single small reef. Another compatible hypothesis of this pattern is that the larvae are able to recognize various types of environmental information, facilitating the selection of optimal micro-habitats. Overall, Acropora coral larvae that are produced from a simultaneous mass-spawning event may have adapted to complex reef topography by means of multi-step habitat selection at settlement, corresponding to different spatial scales.

Suzuki, G.; Arakaki, S.; Kai, S.; Hayashibara, T.

2012-06-01

67

Research planning criteria for regenerative life-support systems applicable to space habitats  

NASA Technical Reports Server (NTRS)

The second phase of analyses that were conducted by the Life Support Systems Group of the 1977 NASA Ames Summer Study is described. This phase of analyses included a preliminary review of relevant areas of technology that can contribute to the development of closed life-support systems for space habitats, the identification of research options in these areas of technology, and the development of guidelines for an effective research program. The areas of technology that were studied included: (1) nutrition, diet, and food processing; (2) higher plant agriculture; (3) animal agriculture; (4) waste conversion and resource recovery; and (5) system stability and safety. Results of these analyses, including recommended research options and criteria for establishing research priorities among these many options, are discussed.

Spurlock, J.; Cooper, W.; Deal, P.; Harlan, A.; Karel, M.; Modell, M.; Moe, P.; Phillips, J.; Putnam, D.; Quattrone, P.

1979-01-01

68

Habitat-associated life history variation within a population of the striped plateau lizard, Sceloporus virgatus  

NASA Astrophysics Data System (ADS)

I examined habitat-associated life history variation in a population of the striped plateau lizard ( Sceloporus virgatus) in the Chiricahua Mountains of southeastern Arizona. Individuals living on a north-facing slope were larger and grew faster (especially smaller individuals) than individuals living on a south-facing slope. Those individuals living in covered woods tended to grow faster than individuals living on open slides. Survivorship was generally (but not statistically significantly) higher in the woods than on the slides, and not different between slopes. Females that lived on a south-facing slope and those that lived in woods reproduced in their first year more often than females that lived on a north-facing slope, or on slides. These life history variations are generally consistent with explanations based on proximate factors such as food availability and potential activity periods.

Smith, Geoffrey R.

1998-04-01

69

Physical habitat predictors of Manayunkia speciosa distribution in the Klamath River and implications for management of Ceratomyxa shasta, a parasite with a complex life cycle  

NASA Astrophysics Data System (ADS)

Management strategies for parasites with complex life cycles may target not the parasite itself, but one of the alternate hosts. One approach is to decrease habitat for the alternate host, and in river systems flow manipulations may be employed. Two-dimensional hydraulic models can be powerful tools for predicting the relationship between flow alterations and changes in physical habit, however they require a rigorous definition of physical habitat for the organism of interest. We present habitat characterization data for the case of the alternate host of a salmonid parasite and introduce how it will be used in conjunction with a 2-dimensional hydraulic model. Ceratomyxa shasta is a myxozoan parasite of salmonids that requires a freshwater polychaete Manayunkia speciosa to complete its life cycle. Manayunkia speciosa is a small (3mm) benthic filter-feeding worm that attaches itself perpendicularly to substrate through construction of a flexible tube. In the Klamath River, CA/OR, C. shasta causes significant juvenile salmon mortality, imposing social and economic losses on commercial, sport and tribal fisheries. An interest in manipulating habitat for the polychaete host to decrease the abundance of C. shasta has therefore developed. Unfortunately, there are limited data on the habitat requirements of M. speciosa or the influence of streamflow regime and hydraulics on population dynamics and infection prevalence. This work aims to address these data needs by identifying physical habitat variables that influence the distribution of M. speciosa and determining the relationship between those variables, M. speciosa population density, and C. shasta infection prevalence. Biological samples were collected from nine sites representing three river features (runs, pools, and eddies) within the Klamath River during the summer and fall of 2010 and 2011. Environmental data including depth, velocity, and substrate, were collected at each polychaete sampling location. We tested for differences in environmental variables and polychaete densities among months and river features. Preliminary data suggest differences in density among months and river features as well as relationships among density and water velocity and substrate type. Polychaetes are currently being assayed for C. shasta infection, which will ultimately be included in our analyses. The data will subsequently be used in conjunction with a 2-dimensional hydraulic model to evaluate habitat stability and the influence of varied streamflow senarios.

Jordan, M. S.; Alexander, J. D.; Grant, G. E.; Bartholomew, J. L.

2011-12-01

70

Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2009  

SciTech Connect

This report describes the 2009 research conducted under the U.S. Army Corps of Engineers (USACE or Corps) project EST-09-P-01, titled “Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary.” The research was conducted by the Pacific Northwest National Laboratory, Marine Science Laboratory and Hydrology Group, in partnership with the University of Washington, School of Aquatic and Fishery Sciences, Columbia Basin Research, and Earl Dawley (NOAA Fisheries, retired). This Columbia River Fish Mitigation Program project, referred to as “Salmonid Benefits,” was started in FY 2009 to evaluate the state-of-the science regarding the ability to quantify the benefits to listed salmonids1 of habitat restoration actions in the lower Columbia River and estuary.

Diefenderfer, Heida L.; Johnson, Gary E.; Sather, Nichole K.; Skalski, John R.; Dawley, Earl M.; Coleman, Andre M.

2010-08-01

71

Novel antagonistic interactions associated with plant polyploidization influence trait selection and habitat preference.  

PubMed

Polyploidization is an important mechanism for sympatric speciation in plants. Still, we know little about whether plant polyploidization leads to insect host shifts, and if novel interactions influence habitat and trait selection in plants. We investigated herbivory by the flower bud gall-forming midge Dasineura cardaminis on tetraploids and octoploids of the herb Cardamine pratensis. Gall midges attacked only octoploid plant populations, and a transplantation experiment confirmed this preference. Attack rates were higher in populations that were shaded, highly connected or occurred along stream margins. Within populations, late-flowering individuals with many flowers were most attacked. Galling reduced seed production and significantly influenced phenotypic selection on flower number. Our results suggest that an increase in ploidy may lead to insect host shifts and that plant ploidy explains insect host use. In newly formed plant polyploids, novel interactions may alter habitat preferences and trait selection, and influence the further evolution of cytotypes. PMID:20100239

Arvanitis, Leena; Wiklund, Christer; Münzbergova, Zuzana; Dahlgren, Johan P; Ehrlén, Johan

2010-03-01

72

Post-settlement Life Cycle Migration Patterns and Habitat Preference of Coral Reef Fish that use Seagrass and Mangrove Habitats as Nurseries  

NASA Astrophysics Data System (ADS)

Mangroves and seagrass beds have received considerable attention as nurseries for reef fish, but comparisons have often been made with different methodologies. Thus, relative importance of different habitats to specific size-classes of reef fish species remains unclear. In this study, 35 transects in 11 sites of mangroves, seagrass beds and coral reef were surveyed daily, in and in front of a marine bay on the island of Curaçao (Netherlands Antilles). The density and size-frequency of nine reef fish species (including herbivores, zoobenthivores and piscivores) was determined during a five-month period using a single methodology, viz. underwater visual census. All species were ' nursery species ' in terms of their high densities of juveniles in mangroves or seagrass beds. Relative density distribution of the size-classes of the selected species over mangroves and seagrass beds suggested high levels of preference for either mangroves or seagrass beds of some species, while other species used both habitats as a nursery. Spatial size distribution of the nine species suggested three possible models for Post-settlement Life Cycle Migrations (PLCM). Haemulon sciurus, Lutjanus griseus, L. apodus, and Acanthurus chirurgus appear to settle and grow up in bay habitats such as mangroves and seagrass beds, and in a later stage migrate to the coral reef (Long Distance PLCM). Juveniles of Acanthurus bahianus and Scarus taeniopterus were found only in bay habitats at close proximity to the coral reef or on the reef itself, and their migration pattern concerns a limited spatial scale (Short Distance PLCM). Some congeneric species carry out either Long Distance PLCM or Short Distance PLCM, thereby temporarily alleviating competition in reef habitats. Haemulon flavolineatum, Ocyurus chrysurus and Scarus iserti displayed a Stepwise PLCM pattern in which smallest juveniles dwell in the mouth of the bay, larger individuals then move to habitats deeper into the bay, where they grow up to a (sub-) adult size at which they migrate to nearby coral reef habitats. This type of stepwise migration in opposite directions, combined with different preference for either mangroves or seagrass beds among (size-classes of) species, shows that reef fish using in-bay habitats during post-settlement life stages may do so by choice and not merely because of stochastic dispersal of their larvae, and underline the necessity of these habitats to Caribbean coral reef systems.

Cocheret de la Morinière, E.; Pollux, B. J. A.; Nagelkerken, I.; van der Velde, G.

2002-08-01

73

Joint Effects of Habitat Heterogeneity and Species’ Life-History Traits on Population Dynamics in Spatially Structured Landscapes  

PubMed Central

Both habitat heterogeneity and species’ life-history traits play important roles in driving population dynamics, yet there is little scientific consensus around the combined effect of these two factors on populations in complex landscapes. Using a spatially explicit agent-based model, we explored how interactions between habitat spatial structure (defined here as the scale of spatial autocorrelation in habitat quality) and species life-history strategies (defined here by species environmental tolerance and movement capacity) affect population dynamics in spatially heterogeneous landscapes. We compared the responses of four hypothetical species with different life-history traits to four landscape scenarios differing in the scale of spatial autocorrelation in habitat quality. The results showed that the population size of all hypothetical species exhibited a substantial increase as the scale of spatial autocorrelation in habitat quality increased, yet the pattern of population increase was shaped by species’ movement capacity. The increasing scale of spatial autocorrelation in habitat quality promoted the resource share of individuals, but had little effect on the mean mortality rate of individuals. Species’ movement capacity also determined the proportion of individuals in high-quality cells as well as the proportion of individuals experiencing competition in response to increased spatial autocorrelation in habitat quality. Positive correlations between the resource share of individuals and the proportion of individuals experiencing competition indicate that large-scale spatial autocorrelation in habitat quality may mask the density-dependent effect on populations through increasing the resource share of individuals, especially for species with low mobility. These findings suggest that low-mobility species may be more sensitive to habitat spatial heterogeneity in spatially structured landscapes. In addition, localized movement in combination with spatial autocorrelation may increase the population size, despite increased density effects. PMID:25232739

Ye, Xinping; Skidmore, Andrew K.; Wang, Tiejun

2014-01-01

74

Where wolves kill moose: the influence of prey life history dynamics on the landscape ecology of predation.  

PubMed

The landscape ecology of predation is well studied and known to be influenced by habitat heterogeneity. Little attention has been given to how the influence of habitat heterogeneity on the landscape ecology of predation might be modulated by life history dynamics of prey in mammalian systems. We demonstrate how life history dynamics of moose (Alces alces) contribute to landscape patterns in predation by wolves (Canis lupus) in Isle Royale National Park, Lake Superior, USA. We use pattern analysis and kernel density estimates of moose kill sites to demonstrate that moose in senescent condition and moose in prime condition tend to be wolf-killed in different regions of Isle Royale in winter. Predation on senescent moose was clustered in one kill zone in the northeast portion of the island, whereas predation on prime moose was clustered in 13 separate kill zones distributed throughout the full extent of the island. Moreover, the probability of kill occurrence for senescent moose, in comparison to prime moose, increased in high elevation habitat with patches of dense coniferous trees. These differences can be attributed, at least in part, to senescent moose being more vulnerable to predation and making different risk-sensitive habitat decisions than prime moose. Landscape patterns emerging from prey life history dynamics and habitat heterogeneity have been observed in the predation ecology of fish and insects, but this is the first mammalian system for which such observations have been made. PMID:24622241

Montgomery, Robert A; Vucetich, John A; Roloff, Gary J; Bump, Joseph K; Peterson, Rolf O

2014-01-01

75

Predation and infanticide influence ideal free choice by a parrot occupying heterogeneous tropical habitats.  

PubMed

The ideal free distribution (IFD) predicts that organisms will disperse to sites that maximize their fitness based on availability of resources. Habitat heterogeneity underlies resource variation and influences spatial variation in demography and the distribution of populations. We relate nest site productivity at multiple scales measured over a decade to habitat quality in a box-nesting population of Forpus passerinus (green-rumped parrotlets) in Venezuela to examine critical IFD assumptions. Variation in reproductive success at the local population and neighborhood scales had a much larger influence on productivity (fledglings per nest box per year) than nest site or female identity. Habitat features were reliable cues of nest site quality. Nest sites with less vegetative cover produced greater numbers of fledglings than sites with more cover. However, there was also a competitive cost to nesting in high-quality, low-vegetative cover nest boxes, as these sites experienced the most infanticide events. In the lowland local population, water depth and cover surrounding nest sites were related with F. passerinus productivity. Low vegetative cover and deeper water were associated with lower predation rates, suggesting that predation could be a primary factor driving habitat selection patterns. Parrotlets also demonstrated directional dispersal. Pairs that changed nest sites were more likely to disperse from poor-quality nest sites to high-quality nest sites rather than vice versa, and juveniles were more likely to disperse to, or remain in, the more productive of the two local populations. Parrotlets exhibited three characteristics fundamental to the IFD: habitat heterogeneity within and between local populations, reliable habitat cues to productivity, and active dispersal to sites of higher fitness. PMID:20135326

Bonebrake, Timothy C; Beissinger, Steven R

2010-06-01

76

REGULAR ARTICLE Plant phenology and life span influence soil pool  

E-print Network

REGULAR ARTICLE Plant phenology and life span influence soil pool dynamics: Bromus tectorum, storage, and release. Using the replacement of C3­C4 perennial grasses by the invasive annual grass Bromus tectorum as a case study, we investigated the influence of phenology and life span on pulse responses

Adair, E. Carol

77

How do dispersal costs and habitat selection influence realized population connectivity?  

PubMed

Despite the importance of dispersal for population connectivity, dispersal is often costly to the individual. A major impediment to understanding connectivity has been a lack of data combining the movement of individuals and their survival to reproduction in the new habitat (realized connectivity). Although mortality often occurs during dispersal (an immediate cost), in many organisms costs are paid after dispersal (deferred costs). It is unclear how such deferred costs influence the mismatch between dispersal and realized connectivity. Through a series of experiments in the field and laboratory, we estimated both direct and indirect deferred costs in a marine bryozoan (Bugula neritina). We then used the empirical data to parameterize a theoretical model in order to formalize predictions about how dispersal costs influence realized connectivity. Individuals were more likely to colonize poor-quality habitat after prolonged dispersal durations. Individuals that colonized poor-quality habitat performed poorly after colonization because of some property of the habitat (an indirect deferred cost) rather than from prolonged dispersal per se (a direct deferred cost). Our theoretical model predicted that indirect deferred costs could result in nonlinear mismatches between spatial patterns of potential and realized connectivity. The deferred costs of dispersal are likely to be crucial for determining how well patterns of dispersal reflect realized connectivity. Ignoring these deferred costs could lead to inaccurate predictions of spatial population dynamics. PMID:22834378

Burgess, Scott C; Treml, Eric A; Marshall, Dustin J

2012-06-01

78

Stable isotope ratios indicate that body condition in migrating passerines is influenced by winter habitat.  

PubMed Central

Although predicted some time ago, there has been little success in demonstrating that the overall fitness of migratory birds depends on the combined influences of their experiences over all seasons. We used stable carbon isotope signatures (delta13C) in the claws of migrating black-throated blue warblers Dendroica caerulescens to infer their wintering habitats and investigated whether winter habitat selection can be linked to condition during migration. Resident bird species with low delta13C corresponded to selection of more mesic habitats, and migrating birds with low delta13C were in better condition than conspecifics with higher delta13C signatures. These findings concur with empirical observations on the wintering grounds, where dominants (mostly males) tend to exclude subordinates from mesic areas (considered to be high-quality habitats). We believe that variation in condition during migration may be one of the key factors determining differences in arrival times and condition at the breeding areas, which in turn have a major influence on reproductive success. PMID:15252988

Bearhop, Stuart; Hilton, Geoff M; Votier, Stephen C; Waldron, Susan

2004-01-01

79

Communication breakdown? Habitat influences on black-capped chickadee dawn choruses  

Microsoft Academic Search

The dawn chorus of the black-capped chickadee (Poecile atricapillus) is a communication network that functions in the dissemination of essential information for both males and females. Habitat\\u000a type may influence the performance of this network, and if recognized, chickadees may attempt to behaviorally compensate for\\u000a detrimental changes in the form of increased movement. We studied the dawn chorus of 66

Ingebjørg Jean K. Hansen; Ken A. Otter; Harry van Oort; Carmen I. Holschuh

2005-01-01

80

The Influence of Dissolved Oxygen on Winter Habitat Selection by Largemouth Bass: An Integration of Field Biotelemetry Studies  

E-print Network

143 The Influence of Dissolved Oxygen on Winter Habitat Selection by Largemouth Bass largemouth bass obtained from a whole-lake sub- merged telemetry array. Fish habitat usage was compared largemouth bass acclimated to winter tem- peratures. Results from the dissolved oxygen measurements made

Cooke, Steven J.

81

Mangrove habitat partitioning by Ucides cordatus (Ucididae): effects of the degree of tidal flooding and tree-species composition during its life cycle  

NASA Astrophysics Data System (ADS)

Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs' life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season.

Wunderlich, A. C.; Pinheiro, M. A. A.

2013-06-01

82

Abiotic vs. biotic influences on habitat selection of coexisting species: Climate change impacts?  

USGS Publications Warehouse

Species are commonly segregated along gradients of microclimate and vegetation. I explore the question of whether segregation is the result of microhabitat partitioning (biotic effects) or choice of differing microclimates (abiotic effects). I explored this question for four ground-nesting bird species that are segregated along a microclimate and vegetation gradient in Arizona. Birds shifted position of their nests on the microhabitat and microclimate gradient in response to changing precipitation over nine years. Similarly, annual bird abundance varied with precipitation across 12 yr. Those shifts in abundance and nesting microhabitat with changing precipitation demonstrate the importance of abiotic influences on bird distributions and habitat choice. However, nest-site shifts and microhabitat use also appear to be influenced by interactions among coexisting species. Moreover, shifts in habitat use by all species caused nest predation (i.e., biotic) costs that increased with increasing distance along the microclimate gradient. These results indicate that abiotic and biotic costs can strongly interact to influence microhabitat choice and abundances of coexisting species. Global climate change impacts have been considered largely in terms of simple distributional shifts, but these results indicate that shifts can also increase biotic costs when species move into habitat types for which they are poorly adapted or that create new biotic interactions.

Martin, T.E.

2001-01-01

83

Influence of Habitat Modifications on Habitat Composition and Anadromous Salmonid Populations in Fish Creek, Oregon, 1983-1988 Annual Report.  

SciTech Connect

Modification of degraded habitats to increase populations of anadromous salmonids is a major focus of management agencies throughout the Pacific Northwest. Millions of dollars are spent annually on such efforts. Inherent in implementing habitat improvements is the need for quantitative evaluation of the biological and physical effects of such work. Reeves et al. (in press), however, noted that such evaluations are rare, making it difficult to assess the true results of habitat work. While it is not economically possible to thoroughly evaluate every habitat project, it is essential that intensive evaluations be done on selected representative projects. One such evaluation program has been underway since 1982 on Fish Creek, a tributary of the Clackamas River near Estacada, OR. Habitat modification has been done by the USDA Forest Service, Estacada Ranger District, Mt. Hood National Forest with funding provided in part by the Bonneville Power Administration (BPA). The USDA Forest Service, Anadromous Fish Habitat Research Unit, Pacific Northwest Research Station (PNW), Corvallis, OR is charged with: (1) evaluating the biological and physical responses to habitat modifications on a basin scale; and (2) developing a cost-benefit analysis of the program. Preliminary results have been reported in a series of annual publications, Everest and Sedell 1983, 1984 and Everest et al. 1985, 1986, 1987, 1988. The objectives of this paper are to: (1) report 1988 observations of biological and physical changes in habitat, salmonid populations, and smolt production in Fish Creek, and (2) examine preliminary trends in fish habitat and populations related to habitat improvement over the period 1983-1988. We have prefaced the trends in the latter objective as preliminary because we believe it could take a minimum of 10 years before the full biological and physical responses to habitat work are realized. We therefore urge caution in interpreting these preliminary results.

Reeves, Gordon H.; Everest, Fred H. (Oregon State University, Pacific Northwest Forest and Range Experiment Station, Corvallis, OR); Hohler, David B. (Mount Hood National Forest, Clackamas River Ranger District, Estacada, OR)

1990-05-01

84

Dress Warm, Focus on the Fluids and Be Patient: Studying Ice Habitats and Constraints on Microbial Life at Low Temperatures  

Microsoft Academic Search

Studies of low-temperature environments on Earth can help guide exploration of other planetary environments that are of interest in the search for potential traces of life (or absence thereof) elsewhere in the solar system. Ice environments and habitats on Earth range from terrestrial permafrost to the polar ice caps or floating sea and lake ice. Despite the complexity of these

H. Eicken; K. Junge; J. Deming

2002-01-01

85

Testing the risk of predation hypothesis: the influence of recolonizing wolves on habitat use by moose.  

PubMed

Considered as absent throughout Scandinavia for >100 years, wolves (Canis lupus) have recently naturally recolonized south-central Sweden. This recolonization has provided an opportunity to study behavioral responses of moose (Alces alces) to wolves. We used satellite telemetry locations from collared moose and wolves to determine whether moose habitat use was affected by predation risk based on wolf use distributions. Moose habitat use was influenced by reproductive status and time of day and showed a different selection pattern between winter and summer, but there was weak evidence that moose habitat use depended on predation risk. The seemingly weak response may have several underlying explanations that are not mutually exclusive from the long term absence of non-human predation pressure: intensive harvest by humans during the last century is more important than wolf predation as an influence on moose behavior; moose have not adapted to recolonizing wolves; and responses may include other behavioral adaptations or occur at finer temporal and spatial levels than investigated. PMID:25015119

Nicholson, Kerry L; Milleret, Cyril; Månsson, Johan; Sand, Håkan

2014-09-01

86

Microbial Biogeography of Arctic Streams: Exploring Influences of Lithology and Habitat  

PubMed Central

Terminal restriction fragment length polymorphism and 16S rRNA gene sequencing were used to explore the community composition of bacterial communities in biofilms on sediments (epipssamon) and rocks (epilithon) in stream reaches that drain watersheds with contrasting lithologies in the Noatak National Preserve, Alaska. Bacterial community composition varied primarily by stream habitat and secondarily by lithology. Positive correlations were detected between bacterial community structure and nutrients, base cations, and dissolved organic carbon. Our results showed significant differences at the stream habitat, between epipssamon and epilithon bacterial communities, which we expected. Our results also showed significant differences at the landscape scale that could be related to different lithologies and associated stream biogeochemistry. These results provide insight into the bacterial community composition of little known and pristine arctic stream ecosystems and illustrate how differences in the lithology, soils, and vegetation community of the terrestrial environment interact to influence stream bacterial taxonomic richness and composition. PMID:22936932

Larouche, Julia R.; Bowden, William B.; Giordano, Rosanna; Flinn, Michael B.; Crump, Byron C.

2012-01-01

87

Effect of habitat preference on frond life span in three Cyathea tree ferns  

NASA Astrophysics Data System (ADS)

It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 ± 14.10 , 7.0 ± 3.07 and 5.0 ± 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 ± 4.12 months) than the two others (C. lepifera (6.8 ± 1.29 months) and C. spinulosa (7.3 ±1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 ± 1.34, 8.27 ± 0.69, and 6.34 ± 0.54 ?mol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 ± 1.95), which was followed by C. spinulosa (18.58 ± 1.37) and C. lepifera (18.68 ± 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span, tree fern, Cyathea, frond C : N ratio

Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori

2013-04-01

88

Elk migration patterns and human activity influence wolf habitat use in the Greater Yellowstone Ecosystem  

USGS Publications Warehouse

Identifying the ecological dynamics underlying human–wildlife conflicts is important for the management and conservation of wildlife populations. In landscapes still occupied by large carnivores, many ungulate prey species migrate seasonally, yet little empirical research has explored the relationship between carnivore distribution and ungulate migration strategy. In this study, we evaluate the influence of elk (Cervus elaphus) distribution and other landscape features on wolf (Canis lupus) habitat use in an area of chronic wolf–livestock conflict in the Greater Yellowstone Ecosystem, USA. Using three years of fine-scale wolf (n = 14) and elk (n = 81) movement data, we compared the seasonal habitat use of wolves in an area dominated by migratory elk with that of wolves in an adjacent area dominated by resident elk. Most migratory elk vacate the associated winter wolf territories each summer via a 40–60 km migration, whereas resident elk remain accessible to wolves year-round. We used a generalized linear model to compare the relative probability of wolf use as a function of GIS-based habitat covariates in the migratory and resident elk areas. Although wolves in both areas used elk-rich habitat all year, elk density in summer had a weaker influence on the habitat use of wolves in the migratory elk area than the resident elk area. Wolves employed a number of alternative strategies to cope with the departure of migratory elk. Wolves in the two areas also differed in their disposition toward roads. In winter, wolves in the migratory elk area used habitat close to roads, while wolves in the resident elk area avoided roads. In summer, wolves in the migratory elk area were indifferent to roads, while wolves in resident elk areas strongly avoided roads, presumably due to the location of dens and summering elk combined with different traffic levels. Study results can help wildlife managers to anticipate the movements and establishment of wolf packs as they expand into areas with migratory or resident prey populations, varying levels of human activity, and front-country rangelands with potential for conflicts with livestock.

Nelson, Abigail; Kauffman, Matthew J.; Middleton, Arthur D.; Jimenez, Mike; McWhirter, Douglas; Barber, Jarrett; Gerow, Ken

2012-01-01

89

The Influence of Nutrients and Physical Habitat in Regulating Algal Biomass in Agricultural Streams  

NASA Astrophysics Data System (ADS)

This study examined the relative influence of nutrients (nitrogen and phosphorus) and habitat on algal biomass in five agricultural regions of the United States. Sites were selected to capture a range of nutrient conditions, with 136 sites distributed over five study areas. Samples were collected in either 2003 or 2004, and analyzed for nutrients (nitrogen and phosphorous) and algal biomass (chlorophyll a). Chlorophyll a was measured in three types of samples, fine-grained benthic material (CHLFG), coarse-grained stable substrate as in rock or wood (CHLCG), and water column (CHLS). Stream and riparian habitat were characterized at each site. TP ranged from 0.004-2.69 mg/l and TN from 0.15-21.5 mg/l, with TN concentrations highest in Nebraska and Indiana streams and TP highest in Nebraska. Benthic algal biomass ranged from 0.47-615 mg/m2, with higher values generally associated with coarse-grained substrate. Seston chlorophyll ranged from 0.2-73.1 ?g/l, with highest concentrations in Nebraska. Regression models were developed to predict algal biomass as a function of TP and/or TN. Seven models were statistically significant, six for TP and one for TN; r 2 values ranged from 0.03 to 0.44. No significant regression models could be developed for the two study areas in the Midwest. Model performance increased when stream habitat variables were incorporated, with 12 significant models and an increase in the r 2 values (0.16-0.54). Water temperature and percent riparian canopy cover were the most important physical variables in the models. While models that predict algal chlorophyll a as a function of nutrients can be useful, model strength is commonly low due to the overriding influence of stream habitat. Results from our study are presented in context of a nutrient-algal biomass conceptual model.

Munn, Mark; Frey, Jeffrey; Tesoriero, Anthony

2010-03-01

90

The influence of nutrients and physical habitat in regulating algal biomass in agricultural streams.  

PubMed

This study examined the relative influence of nutrients (nitrogen and phosphorus) and habitat on algal biomass in five agricultural regions of the United States. Sites were selected to capture a range of nutrient conditions, with 136 sites distributed over five study areas. Samples were collected in either 2003 or 2004, and analyzed for nutrients (nitrogen and phosphorous) and algal biomass (chlorophyll a). Chlorophyll a was measured in three types of samples, fine-grained benthic material (CHL(FG)), coarse-grained stable substrate as in rock or wood (CHL(CG)), and water column (CHL(S)). Stream and riparian habitat were characterized at each site. TP ranged from 0.004-2.69 mg/l and TN from 0.15-21.5 mg/l, with TN concentrations highest in Nebraska and Indiana streams and TP highest in Nebraska. Benthic algal biomass ranged from 0.47-615 mg/m(2), with higher values generally associated with coarse-grained substrate. Seston chlorophyll ranged from 0.2-73.1 microg/l, with highest concentrations in Nebraska. Regression models were developed to predict algal biomass as a function of TP and/or TN. Seven models were statistically significant, six for TP and one for TN; r(2) values ranged from 0.03 to 0.44. No significant regression models could be developed for the two study areas in the Midwest. Model performance increased when stream habitat variables were incorporated, with 12 significant models and an increase in the r(2) values (0.16-0.54). Water temperature and percent riparian canopy cover were the most important physical variables in the models. While models that predict algal chlorophyll a as a function of nutrients can be useful, model strength is commonly low due to the overriding influence of stream habitat. Results from our study are presented in context of a nutrient-algal biomass conceptual model. PMID:20143065

Munn, Mark; Frey, Jeffrey; Tesoriero, Anthony

2010-03-01

91

The Influence of Mitigation on Sage-Grouse Habitat Selection within an Energy Development Field  

PubMed Central

Growing global energy demands ensure the continued growth of energy development. Energy development in wildlife areas can significantly impact wildlife populations. Efforts to mitigate development impacts to wildlife are on-going, but the effectiveness of such efforts is seldom monitored or assessed. Greater sage-grouse (Centrocercus urophasianus) are sensitive to energy development and likely serve as an effective umbrella species for other sagebrush-steppe obligate wildlife. We assessed the response of birds within an energy development area before and after the implementation of mitigation action. Additionally, we quantified changes in habitat distribution and abundance in pre- and post-mitigation landscapes. Sage-grouse avoidance of energy development at large spatial scales is well documented. We limited our research to directly within an energy development field in order to assess the influence of mitigation in close proximity to energy infrastructure. We used nest-location data (n = 488) within an energy development field to develop habitat selection models using logistic regression on data from 4 years of research prior to mitigation and for 4 years following the implementation of extensive mitigation efforts (e.g., decreased activity, buried powerlines). The post-mitigation habitat selection models indicated less avoidance of wells (well density ? = 0.18 ± 0.08) than the pre-mitigation models (well density ? = -0.09 ± 0.11). However, birds still avoided areas of high well density and nests were not found in areas with greater than 4 wells per km2 and the majority of nests (63%) were located in areas with ? 1 well per km2. Several other model coefficients differed between the two time periods and indicated stronger selection for sagebrush (pre-mitigation ? = 0.30 ± 0.09; post-mitigation ? = 0.82 ± 0.08) and less avoidance of rugged terrain (pre-mitigation ? = -0.35 ± 0.12; post-mitigation ? = -0.05 ± 0.09). Mitigation efforts implemented may be responsible for the measurable improvement in sage-grouse nesting habitats within the development area. However, we cannot reject alternative hypotheses concerning the influence of population density and intraspecific competition. Additionally, we were unable to assess the actual fitness consequences of mitigation or the source-sink dynamics of the habitats. We compared the pre-mitigation and post-mitigation models predicted as maps with habitats ranked from low to high relative probability of use (equal-area bins: 1 – 5). We found more improvement in habitat rank between the two time periods around mitigated wells compared to non-mitigated wells. Informed mitigation within energy development fields could help improve habitats within the field. We recommend that any mitigation effort include well-informed plans to monitor the effectiveness of the implemented mitigation actions that assess both habitat use and relevant fitness parameters. PMID:25835296

Fedy, Bradley C.; Kirol, Christopher P.; Sutphin, Andrew L.; Maechtle, Thomas L.

2015-01-01

92

Life Style: Personality, Role Concept, Attitudes, Influences, and Choices.  

ERIC Educational Resources Information Center

The relationships between life style and personality, role concept, attitudes, the influence of significant others, and personal and professional choices are examined for women pursuing various life styles. College-graduated women (N=87) between ages 30 and 58 were divided into three groups based on career-home commitment. Traditionals (N=24) left…

O'Connell, Agnes N.

93

Robotic Technologies for Surveying Habitats and Seeking Evidence of Life: Results from the 2004 Field Experiments of the "Life in the Atacama" Project  

NASA Technical Reports Server (NTRS)

The Chilean Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. Evidence suggests that the interior of the Atacama is lifeless, yet where the desert meets the Pacific coastal range dessication-tolerant microorganisms are known to exist. The gradient of biodiversity and habitats in the Atacama's subregions remain unexplored and are the focus of the Life in the Atacama project. Our field investigation attempts to bring further scientific understanding of the Atacama as a habitat for life through the creation of robotic astrobiology. This involves capabilities for autonomously traversing hundreds of kilometers while deploying sensors to survey the varying geologic and biologic properties of the environment, Fig. 1. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain in search of the habitats in which life can survive, or may have in the past.

Wettergreen, D.; Cabrol, N.; Whittaker, W.; Diaz, G. Chong; Calderon, F.; Heys, S.; Jonak, D.; Lueders, A.; Moersch, J.; Pane, D.

2005-01-01

94

Indigenous Microbiota and Habitat Influence Escherichia coli Survival More than Sunlight in Simulated Aquatic Environments  

PubMed Central

The reported fate of Escherichia coli in the environment ranges from extended persistence to rapid decline. Incomplete understanding of factors that influence survival hinders risk assessment and modeling of the fate of fecal indicator bacteria (FIB) and pathogens. FIB persistence in subtropical aquatic environments was explored in outdoor mesocosms inoculated with five E. coli strains. The manipulated environmental factors were (i) presence or absence of indigenous microbiota (attained by natural, disinfected, and cycloheximide treatments), (ii) freshwater versus seawater, and (iii) water column versus sediment matrices. When indigenous microbes were removed (disinfected), E. coli concentrations decreased little despite exposure to sunlight. Conversely, under conditions that included the indigenous microbiota (natural), significantly greater declines in E. coli occurred regardless of the habitat. The presence of indigenous microbiota and matrix significantly influenced E. coli decline, but their relative importance differed in freshwater versus seawater. Cycloheximide, which inhibits protein synthesis in eukaryotes, significantly diminished the magnitude of E. coli decline in water but not in sediments. The inactivation of protozoa and bacterial competitors (disinfected) caused a greater decline in E. coli than cycloheximide alone in water and sediments. These results indicate that the autochthonous microbiota are an important contributor to the decline of E. coli in fresh and seawater subtropical systems, but their relative contribution is habitat dependent. This work advances our understanding of how interactions with autochthonous microbiota influence the fate of E. coli in aquatic environments and provides the framework for studies of the ecology of enteric pathogens and other allochthonous bacteria in similar environments. PMID:23811514

Korajkic, Asja; Wanjugi, Pauline

2013-01-01

95

Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus  

NASA Astrophysics Data System (ADS)

Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the F ST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species.

González-Wangüemert, Mercedes; Vergara-Chen, Carlos

2014-06-01

96

Degree of adaptive response in urban tolerant birds shows influence of habitat-of-origin  

PubMed Central

Urban exploiters and adapters are often coalesced under a term of convenience as ‘urban tolerant’. This useful but simplistic characterisation masks a more nuanced interplay between and within assemblages of birds that are more or less well adapted to a range of urban habitats. I test the hypotheses that objectively-defined urban exploiter and suburban adapter assemblages within the broad urban tolerant grouping in Melbourne vary in their responses within the larger group to predictor variables, and that the most explanatory predictor variables vary between the two assemblages. A paired, partitioned analysis of exploiter and adapter preferences for points along the urban–rural gradient was undertaken to decompose the overall trend into diagnosable parts for each assemblage. In a similar way to that in which time since establishment has been found to be related to high urban densities of some bird species and biogeographic origin predictive of urban adaptation extent, habitat origins of members of bird assemblages influence the degree to which they become urban tolerant. Bird species that objectively classify as urban tolerant will further classify as either exploiters or adapters according to the degree of openness of their habitats-of-origin. PMID:24688881

2014-01-01

97

Factors Influencing Expanded Use of Urban Marine Habitats by Foraging Wading Birds  

EPA Science Inventory

Urban marine habitats are often utilized by wildlife for foraging and other activities despite surrounding anthropogenic impact or disturbance. However little is known of the ecological factors that determine habitat value of these and other remnant natural habitats. We examine...

98

Influence of Mowing Artemisia tridentata ssp. wyomingensis on Winter Habitat for Wildlife  

NASA Astrophysics Data System (ADS)

Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter habitat for wildlife is lacking. This information is crucial because many wildlife species depended on A. tridentata spp. wyomingensis plant communities for winter habitat and consume significant quantities of Artemisia during this time . Furthermore, information is generally limited describing the recovery of A. tridentata spp. wyomingensis to mowing and the impacts of mowing on stand structure. Stand characteristics and Artemisia leaf tissue crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations were measured in midwinter on 0-, 2-, 4-, and 6-year-old fall-applied mechanical (mowed at 20 cm height) treatments and compared to adjacent untreated (control) areas. Mowing compared to the control decreased Artemisia cover, density, canopy volume, canopy elliptical area, and height ( P < 0.05), but all characteristics were recovering ( P < 0.05). Mowing A. tridentata spp. wyomingensis plant communities slightly increases the nutritional quality of Artemisia leaves ( P < 0.05), but it simultaneously results in up to 20 years of decrease in Artemisia structural characteristics. Because of the large reduction in A. tridentata spp. wyomingensis for potentially 20 years following mowing, mowing should not be applied in Artemisia facultative and obligate wildlife winter habitat. Considering the decline in A. tridentata spp. wyomingensis-dominated landscapes, we caution against mowing these communities.

Davies, Kirk W.; Bates, Jonathan D.; Johnson, Dustin D.; Nafus, Aleta M.

2009-07-01

99

Influence of mowing Artemisia tridentata ssp. wyomingensis on winter habitat for wildlife.  

PubMed

Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter habitat for wildlife is lacking. This information is crucial because many wildlife species depended on A. tridentata spp. wyomingensis plant communities for winter habitat and consume significant quantities of Artemisia during this time. Furthermore, information is generally limited describing the recovery of A. tridentata spp. wyomingensis to mowing and the impacts of mowing on stand structure. Stand characteristics and Artemisia leaf tissue crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations were measured in midwinter on 0-, 2-, 4-, and 6-year-old fall-applied mechanical (mowed at 20 cm height) treatments and compared to adjacent untreated (control) areas. Mowing compared to the control decreased Artemisia cover, density, canopy volume, canopy elliptical area, and height (P < 0.05), but all characteristics were recovering (P < 0.05). Mowing A. tridentata spp. wyomingensis plant communities slightly increases the nutritional quality of Artemisia leaves (P < 0.05), but it simultaneously results in up to 20 years of decrease in Artemisia structural characteristics. Because of the large reduction in A. tridentata spp. wyomingensis for potentially 20 years following mowing, mowing should not be applied in Artemisia facultative and obligate wildlife winter habitat. Considering the decline in A. tridentata spp. wyomingensis-dominated landscapes, we caution against mowing these communities. PMID:19159967

Davies, Kirk W; Bates, Jonathan D; Johnson, Dustin D; Nafus, Aleta M

2009-07-01

100

Modeling habitat split: landscape and life history traits determine amphibian extinction thresholds.  

PubMed

Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations. PMID:23818967

Fonseca, Carlos Roberto; Coutinho, Renato M; Azevedo, Franciane; Berbert, Juliana M; Corso, Gilberto; Kraenkel, Roberto A

2013-01-01

101

Life on the rocks: habitat use drives morphological and performance evolution in lizards.  

PubMed

As a group, lizards occupy a vast array of habitats worldwide, yet there remain relatively few cases where habitat use (ecology), morphology, and thus, performance, are clearly related. The best known examples include: increased limb length in response to increased arboreal perch diameter in anoles and increased limb length in response to increased habitat openness for some skinks. Rocky habitats impose strong natural selection on specific morphological characteristics, which differs from that imposed on terrestrial species, because moving about on inclined substrates of irregular sizes and shapes constrains locomotor performance in predictable ways. We quantified habitat use, morphology, and performance of 19 species of lizards (family Scincidae, subfamily Lygosominae) from 23 populations in tropical Australia. These species use habitats with considerable variation in rock availability. Comparative phylogenetic analyses revealed that occupation of rock-dominated habitats correlated with the evolution of increased limb length, compared to species from forest habitats that predominantly occupied leaf litter. Moreover, increased limb length directly affected performance, with species from rocky habitats having greater sprinting, climbing, and clinging ability than their relatives from less rocky habitats. Thus, we found that the degree of rock use is correlated with both morphological and performance evolution in this group of tropical lizards. PMID:19137951

Goodman, Brett A; Miles, Donald B; Schwarzkopf, Lin

2008-12-01

102

Habitat preferences and life history of the red scorpion fish, Scorpaena notata, in the Mediterranean  

NASA Astrophysics Data System (ADS)

Scorpaena notata is a small, sedentary scorpaenid species widely distributed in the Mediterranean and adjacent waters of the Atlantic. In the western Mediterranean it inhabits coastal continental shelf bottoms. In the Balearic Islands, these bottoms are characterised by the presence of the facies with red algae, including both Peyssonnelia and mäerl beds. These beds enhance the structural complexity, biodiversity and secondary production of the soft bottoms. Due to the oceanographic conditions of the Islands, the facies with red algae are especially rich in terms of biomass and algal coverage, and are widespread distributed between 40 and 90 m depth, where trawlers exploiting the continental shelf operate. The present work studies the biology of S. notata and its relationship with habitat characteristics. Special attention is focused on the aspects related to fish condition and growth as a tool to assess the importance of the facies with red algae for fish. The reproduction period of S. notata in the Balearic Islands occurs in summer and is accompanied by a decrease in hepatic condition, as it happens in the adjacent area off the Iberian Peninsula; however, in contrast with this adjacent area, this period is accompanied by a decrease in somatic condition and an increase in feeding potential, which suggests that these could be adaptations to the higher oligotrophy of the Archipelago. The standardised algal biomass (mostly Rhodophyceae) present in the bottoms positively affected the abundance, somatic condition and feeding potential of S. notata. Individuals inhabiting bottoms with the highest algal biomass showed faster growth than the entire population analysed together. Both, the structural complexity and the availability of preys in the facies with red algae are revealed as advantageous traits for the life history of fish. Taking into account the importance of individual health for the overall success of the population, the indexes studied here could be a useful tool for identifying high quality or essential fish habitats. Our results highlight the importance of the facies with red algae as oasis of high productivity where benthic fish can circumvent the general oligotrophic conditions of the Mediterranean, and the necessity of urgent management measures in order to protect them from human impacts.

Ordines, F.; Quetglas, A.; Massutí, E.; Moranta, J.

2009-12-01

103

Removal of small dams and its influence on physical habitat for salmonids in a Norwegian river  

NASA Astrophysics Data System (ADS)

While research and implementation of upstream migration solutions is extensive, and indeed often successful, full scale restoration projects and investigations of their influence on fish biology are rare in Norway. Acid deposition in Norwegian catchments peaked in the 1980's and resulted in both chronically and episodically acidified rivers and Salmonids in River Nidelva, one of the largest cathments in southern Norway, where extinct for decades. During this period hydropower development in the river paid limited attention to aquatic ecology. Weirs were constructed for esthetic purposes in the late 1970's and turned a 3 km stretch into a lake habitat, well suited for lake dwelling fish species, but unsuited for migration, spawning and juvenile habitat for salmonids. Since 2005, continuous liming to mitigate acidification has improved the water quality and a program for reintroduction of Atlantic salmon has been implemented. We used hydraulic modeling to plan the removal of two weirs on a bypass reach of the river. The 50 meters wide concrete weirs were blasted and removed in 2007, and ecological monitoring has been carried out in the river to assess the effect of weir removal. Topographic mapping, hydraulic measurements and modeling, in combination with biological surveys before and after the removal of the weirs, has proved to represent a powerful method for design of physical habitat adjustments and assessing their influence on fish biology. The model results also supported a rapid progress of planning and executing of the works. While telemetry studies before weir removal suggested that adult migration past the weirs was delayed with several weeks the fish can now pass the reach with minor obstacles. Spawning sites were discovered in the old bed substrate and were occupied already the first season after water velocities increased to suitable levels for spawning. Accordingly, the densities of Atlantic salmon juveniles have shown a marked increased after the conclusion of the project. Catches of pike and cyprinids on the reach is reduced, indicating that their habitat is no longer suitable, while salmon anglers have found new favorite spots in the restored pools and runs.

Fjeldstad, Hans-Petter; Barlaup, Bjørn; Stickler, Morten; Alfredsen, Knut; Gabrielsen, Sven-Erik

2010-05-01

104

Chronic diseases influence major life changing decisions: a new domain in quality of life research.  

PubMed

The purpose of this review is to identify knowledge about the influence of chronic disease on major life changing decisions (MLCDs). This review was carried out in three stages: identification of key search terms; selection of databases and searching parameters; and evaluation of references. Only two articles matched the main search term 'major life changing decisions'. No article reviewed or measured the influence of chronic disease on major life changing decisions. However, 76 articles and various sections of seven books were identified that provided insight into this area and these are reviewed in detail. This literature review has brought together previously scattered information on chronic disease impact on important patient life decisions. These include decisions related to having children, marriage and divorce, job and career choice, social life, holidays, travelling and education. Lifestyle decisions viewed by patients as major decisions are also documented. The influence of cancer on life decisions is discussed, as are affected life decisions of other family members. Very little information is available about the long-term impact of chronic disease on patients' lives and methodology to assess long-term impact is incomplete. This review points to a novel dimension to health-related outcome research, the impact of chronic disease on major life changing decisions, and its possible implication for patients' future health. PMID:21659399

Bhatti, Zu; Salek, Ms; Finlay, Ay

2011-06-01

105

Plenty to eat, nothing to breathe: challenges to life in serpentinite habitats (Invited)  

NASA Astrophysics Data System (ADS)

When tectonic uplift exposes ultramafic rocks from the Earth's mantle to water from the surface, iron minerals are oxidized and release hydrogen gas (H2) in a set of geochemical reactions known collectively as serpentinization. The generation of high concentrations of H2 can also lead to abiotic synthesis of organic molecules, thereby providing an exothermic, abundant source of electron donors and organic carbon. The major biological challenges of serpentinization-influenced habitats appear to be the extremely high pH (typically pH 9-12), the associated lack of inorganic carbon, and the lack of electron acceptors due to the highly reducing conditions (1). These challenges are apparently overcome by the prolific archaeal and bacterial biofilms associated with the carbonate chimneys at the Lost City hydrothermal field. Cell densities exceed 109 cells per gram of chimney material (2). Phylogenetic, metagenomic, and experimental evidence indicate that the communities are supported by the copious quantities of H2, CH4, and sulphur fluxing from the chimneys, but the metabolic pathways and associated thermodynamic factors are still unclear (3). In particular, the oxidants that microbes couple with H2, CH4, and sulphur at Lost City remain a matter of speculation. The mystery of the oxidants has also featured in our recent explorations of continental sites of serpentinization. In strong contrast to the Lost City chimneys, these continental fluids tend to contain very little biomass (fewer than 102 cells per mL in the most extreme cases). Presumably, the anoxic, pH 12 fluids enriched in H2 and CH4 are flowing from subsurface habitats where there must be a surplus of reductants and carbon (4). Given the extremely reducing, anoxic conditions, though, oxidants are likely to be very limited in these environments. The ';oxidant limitation' hypothesis is particularly intriguing because of its counter-intuitive nature: to our knowledge, no other habitats on Earth have a surplus of reducants and a lack of oxidants. Other limitations must also be considered, including the extremely high pH and the possible lack of nitrogen, phosphorus, and trace metals. Comparisons of the bacterial communities at Lost City and continental serpentinite springs have highlighted the dynamic nature of the Lost City chimneys, where highly reducing hydrothermal fluids mix with oxidizing seawater (1,5). Consequently, a truly subsurface microbial community below Lost City remains to be detected and will require future sampling efforts to focus on the collection of high-quality, end-member hydrothermal fluids. References 1. Schrenk MO, Brazelton WJ, Lang SQ. 2013. Rev. Mineral. Geochem. 75:575-606. 2. Schrenk MO, Kelley DS, Bolton SA, Baross JA. 2004. Environ. Microbiol. 6:1086-1095. 3. Brazelton WJ, Mehta MP, Kelley DS, Baross JA. 2011. mBio2:4. doi:10.1128/mBio.00127-11. 4. Szponar, N., W.J. Brazelton, M.O. Schrenk, D.M. Bower, A. Steele, P.L. Morrill. 2013. Icarus. 224: 286-296. 5. Brazelton WJ, Schrenk MO, Kelley DS, Baross JA. 2006. Appl. Environ. Microbiol. 72:6257-6270.

Brazelton, W. J.; Twing, K. I.; Crespo-Medina, M.; Lang, S. Q.; Schrenk, M. O.

2013-12-01

106

Habitat features influencing jaguar Panthera onca (Carnivora: Felidae) occupancy in Tortuguero National Park, Costa Rica.  

PubMed

Habitat characteristics and human activities are known to play a major role in the occupancy of jaguars Panthera onca across their range, however the key variables influencing jaguar distribution in Tortuguero National Park, Costa Rica, have yet to be identified. This study evaluated jaguar occupancy in Tortuguero National Park and the surrounding area. Jaguar detection/non-detection data was collected using digital camera traps distributed within the boundaries of the protected area. Local community members were also interviewed to determine jaguar occurrence in the Park's buffer zone. Occupancy models were then applied to identify the habitat characteristics that may better explain jaguar distribution across the study area. From June 2012 to June 2013, a total of 4,339 camera trap days were used to identify 18 individual jaguars inside the protected area; 17 of these jaguars were exclusively detected within the coastal habitat, whilst the remaining individual was detected solely within the interior of the Park. Interviewees reported 61 occasions of jaguar presence inside the buffer zone, between 1995 and 2013, with 80% of these described by the communities of Lomas de Sierpe, Barra de Parismina and La Aurora. These communities also reported the highest levels of livestock predation by jaguars (85% of attacks). In the study area, jaguar occurrence was positively correlated with the seasonal presence of nesting green turtles Chelonia mydas, and negatively correlated with distance to the Park boundary. Our findings suggested that the current occupancy of the jaguar in the study area may be a response to: 1) the vast availability of prey (marine turtles) on Tortuguero beach, 2) the decline of its primary prey species as a result of illegal hunting inside the Park, and 3) the increase in anthropogenic pressures in the Park boundaries. PMID:25720179

Arroyo-Arce, Stephanny; Guilder, James; Salom-Pérez, Roberto

2014-12-01

107

The North Atlantic Ocean as habitat for Calanus finmarchicus: Environmental factors and life history traits  

NASA Astrophysics Data System (ADS)

Here we present a new, pan-Atlantic compilation and analysis of data on Calanus finmarchicus abundance, demography, dormancy, egg production and mortality in relation to basin-scale patterns of temperature, phytoplankton biomass, circulation and other environmental characteristics in the context of understanding factors determining the distribution and abundance of C. finmarchicus across its North Atlantic habitat. A number of themes emerge: (1) the south-to-north transport of plankton in the northeast Atlantic contrasts with north-to-south transport in the western North Atlantic, which has implications for understanding population responses of C. finmarchicus to climate forcing, (2) recruitment to the youngest copepodite stages occurs during or just after the phytoplankton bloom in the east whereas it occurs after the bloom at many western sites, with up to 3.5 months difference in recruitment timing, (3) the deep basin and gyre of the southern Norwegian Sea is the centre of production and overwintering of C. finmarchicus, upon which the surrounding waters depend, whereas, in the Labrador/Irminger Seas production mainly occurs along the margins, such that the deep basins serve as collection areas and refugia for the overwintering populations, rather than as centres of production, (4) the western North Atlantic marginal seas have an important role in sustaining high C. finmarchicus abundance on the nearby coastal shelves, (5) differences in mean temperature and chlorophyll concentration between the western and eastern North Atlantic are reflected in regional differences in female body size and egg production, (6) regional differences in functional responses of egg production rate may reflect genetic differences between western and eastern populations, (7) dormancy duration is generally shorter in the deep waters adjacent to the lower latitude western North Atlantic shelves than in the east, (8) there are differences in stage-specific daily mortality rates between eastern and western shelves and basins, but the survival trajectories for cohort development from CI to CV are similar, and (9) early life stage survival is much lower in regions where C. finmarchicus is found with its congeners, C. glacialis and/or C. hyperboreus. This compilation and analysis provides new knowledge for evaluation and parameterisation of population models of C. finmarchicus and their responses to climate change in the North Atlantic. The strengths and weaknesses of modeling approaches, including a statistical approach based on ecological niche theory and a dynamical approach based on knowledge of spatial population dynamics and life history, are discussed, as well as needs for further research.

Melle, Webjørn; Runge, Jeffrey; Head, Erica; Plourde, Stéphane; Castellani, Claudia; Licandro, Priscilla; Pierson, James; Jonasdottir, Sigrun; Johnson, Catherine; Broms, Cecilie; Debes, Høgni; Falkenhaug, Tone; Gaard, Eilif; Gislason, Astthor; Heath, Michael; Niehoff, Barbara; Nielsen, Torkel Gissel; Pepin, Pierre; Stenevik, Erling Kaare; Chust, Guillem

2014-12-01

108

Influence of habitat modification on the intestinal helminth community ecology of cottontail rabbit populations.  

PubMed

The influence of five brush management treatments using the herbicides tebuthiuron and triclopyr, with or without prescribed burning, on the intestinal helminth community of cottontail rabbits (Sylvilagus floridanus) was studied in 1987 on the Cross Timbers Experimental Range in Payne County, Oklahoma (USA). Six helminth species were found (Dermatoxys veligera, Trichostrongylus calcaratus, Passalurus nonanulatus, Wellcomia longejector, Taenia pisiformis cystercercus, and Mosgovoyia pectinata americana) in 102 rabbits (88 adult and 14 juveniles) collected over two seasons (winter and summer). Prevalence of M. pectinata americana in cottontail rabbits was significantly greater in untreated control pastures than herbicide treated pastures in winter, while prevalence of T. pisiformis was significantly greater in burned than unburned pastures. Abundances of helminth species in the intestinal tract of cottontail rabbits were unaffected by brush treatments. Mosgovoyia pectinata americana abundance demonstrated a highly significant increase from winter to summer; conversely, abundance of all oxyurid pinworms combined (D. veligera, P. nonanulatus, W. longejector) was significantly higher in winter than summer. Helminth community dynamics were significantly influenced by season, but were unaffected by brush treatments. Habitat modification could have influenced cestode transmission by altering the ecology of invertebrate and vertebrate hosts. PMID:2338720

Boggs, J F; McMurry, S T; Leslie, D M; Engle, D M; Lochmiller, R L

1990-04-01

109

Spatial structure and nest demography reveal the influence of competition, parasitism and habitat quality on slavemaking ants and their hosts  

PubMed Central

Background Natural communities are structured by intra-guild competition, predation or parasitism and the abiotic environment. We studied the relative importance of these factors in two host-social parasite ecosystems in three ant communities in Europe (Bavaria) and North America (New York, West Virginia). We tested how these factors affect colony demography, life-history and the spatial pattern of colonies, using a large sample size of more than 1000 colonies. The strength of competition was measured by the distance to the nearest competitor. Distance to the closest social parasite colony was used as a measure of parasitism risk. Nest sites (i.e., sticks or acorns) are limited in these forest ecosystems and we therefore included nest site quality as an abiotic factor in the analysis. In contrast to previous studies based on local densities, we focus here on the positioning and spatial patterns and we use models to compare our predictions to random expectations. Results Colony demography was universally affected by the size of the nest site with larger and more productive colonies residing in larger nest sites of higher quality. Distance to the nearest competitor negatively influenced host demography and brood production in the Bavarian community, pointing to an important role of competition, while social parasitism was less influential in this community. The New York community was characterized by the highest habitat variability, and productive colonies were clustered in sites of higher quality. Colonies were clumped on finer spatial scales, when we considered only the nearest neighbors, but more regularly distributed on coarser scales. The analysis of spatial positioning within plots often produced different results compared to those based on colony densities. For example, while host and slavemaker densities are often positively correlated, slavemakers do not nest closer to potential host colonies than expected by random. Conclusions The three communities are differently affected by biotic and abiotic factors. Some of the differences can be attributed to habitat differences and some to differences between the two slavemaking-host ecosystems. The strong effect of competition in the Bavarian community points to the scarcity of resources in this uniform habitat compared to the other more diverse sites. The decrease in colony aggregation with scale indicates fine-scale resource hotspots: colonies are locally aggregated in small groups. Our study demonstrates that species relationships vary across scales and spatial patterns can provide important insights into species interactions. These results could not have been obtained with analyses based on local densities alone. Previous studies focused on social parasitism and its effect on host colonies. The broader approach taken here, considering several possible factors affecting colony demography and not testing each one in isolation, shows that competition and environmental variability can have a similar strong impact on demography and life-history of hosts. We conclude that the effects of parasites or predators should be studied in parallel to other ecological influences. PMID:21443778

2011-01-01

110

Does riparian habitat condition influence mammalian carnivore abundance in Mediterranean ecosystems?  

Microsoft Academic Search

The severe loss or degradation of riparian habitats has led to their impoverishment and impaired function, which may have\\u000a severe consequences on both the riparian habitats themselves and their associated biota, including mammalian carnivores. We\\u000a selected 70 riparian habitat reaches to evaluate the condition of the riparian habitats in southern Portugal and their use\\u000a by carnivores. These sites were assessed

Hugo M. Matos; Maria J. Santos; Francisco Palomares; Margarida Santos-Reis

2009-01-01

111

Density of red alder ( Alnus rubra ) in headwaters influences invertebrate and detritus subsidies to downstream fish habitats in Alaska  

Microsoft Academic Search

We investigated the influence of red alder (Alnus rubra) stand density in upland, riparian forests on invertebrate and detritus transport from fishless headwater streams to downstream, salmonid habitats in southeastern Alaska. Red alder commonly regenerates after soil disturbance (such as from natural landsliding or timber harvesting), and is common along streams in varying densities, but its effect on food delivery

Mark S. Wipfli; Jake Musslewhite

2004-01-01

112

The influence of stream habitat and water quality on macroinvertebrate communities in degraded streams of northwest Mississippi  

Microsoft Academic Search

Streams in the loess hills of northwest Mississippi have undergone dramatic physical changes since European settlement and both physical and water quality processes may play a role in influencing biotic communities of these stream systems. The objectives of this study were to identify the response of macroinvertebrate taxa to water quality and habitat parameters in streams of northwest Mississippi, examine

J. D. Maul; J. L. Farris; C. D. Milam; C. M. Cooper; S. Testa III; D. L. Feldman

2004-01-01

113

FEEDING HABITATS OF NESTING WADING BIRDS: SPATIAL USE AND SOCIAL INFLUENCES  

Microsoft Academic Search

In an effort to relate social interactions to feeding-habitat use, I observed six species of wading birds near a major colony site in coastal North Carolina. Three spatial scales of habitat use were considered: the general orientation to and from the colony (coarsest level), the habitat \\

R. MICHAEL ERWIN

114

Abstract Habitat loss and fragmentation can influ-ence the genetic structure of biological populations.  

E-print Network

Microsatellites Æ Ursus americanus floridanus Introduction The fragmentation and loss of habitat is one consequences of habitat fragmentation and loss: the case of the Florida black bear (Ursus americanus floridanus populations. We studied the genetic consequences of habitat frag- mentation in Florida black bear (Ursus

Oli, Madan K.

115

Societal Influences on Health and Life-styles  

PubMed Central

Strong sociocultural forces affect individual attitudes toward health and choice of life-style. Economic deprivation fosters negative health behaviors. Positive health habits are reinforced by discrete societal groups. The news media, particularly television, disseminate much useful health information, though the overall educational value is diminished by the content of commercial messages and programming. The automobile is a major societal influence, but neither individual drivers nor the car manufacturers give enough priority to highway safety, leaving that role to governmental regulation. American industry is becoming a positive influence in the encouragement of good health habits, and fashion is lately an important ally in personal health maintenance. PMID:6523860

Ulmer, David D.

1984-01-01

116

Societal influences on health and life-styles.  

PubMed

Strong sociocultural forces affect individual attitudes toward health and choice of life-style. Economic deprivation fosters negative health behaviors. Positive health habits are reinforced by discrete societal groups. The news media, particularly television, disseminate much useful health information, though the overall educational value is diminished by the content of commercial messages and programming. The automobile is a major societal influence, but neither individual drivers nor the car manufacturers give enough priority to highway safety, leaving that role to governmental regulation. American industry is becoming a positive influence in the encouragement of good health habits, and fashion is lately an important ally in personal health maintenance. PMID:6523860

Ulmer, D D

1984-12-01

117

Multi-scale patterns of habitat use by Roanoke logperch (Percina rex) in Virginia rivers: a comparison among populations and life stages.  

E-print Network

Multi-scale patterns of habitat use by Roanoke logperch (Percina rex) in Virginia rivers) in Virginia rivers: a comparison among populations and life stages. Amanda Rosenberger (ABSTRACT) The Roanoke in three river systems in Virginia, including comparisons among rivers and life stages. The first study

118

Habitat fragmentation and species loss across three interacting trophic levels: effects of life-history and food-web traits.  

PubMed

Not all species are likely to be equally affected by habitat fragmentation; thus, we evaluated the effects of size of forest remnants on trophically linked communities of plants, leaf-mining insects, and their parasitoids. We explored the possibility of differential vulnerability to habitat area reduction in relation to species-specific and food-web traits by comparing species-area regression slopes. Moreover, we searched for a synergistic effect of these traits and of trophic level. We collected mined leaves and recorded plant, leaf miner, and parasitoid species interactions in five 100-m2 transects in 19 Chaco Serrano woodland remnants in central Argentina. Species were classified into extreme categories according to body size, natural abundance, trophic breadth, and trophic level. Species-area slopes differed between groups with extreme values of natural abundance or trophic specialization. Nevertheless, synergistic effects of life-history and food-web traits were only found for trophic level and trophic breadth: area-related species loss was highest for specialist parasitoids. It has been suggested that species position within interaction webs could determine their vulnerability to extinction. Our results provide evidence that food-web parameters, such as trophic level and trophic breadth, affect species sensitivity to habitat fragmentation. PMID:19765035

Cagnolo, Luciano; Valladares, Graciela; Salvo, Adriana; Cabido, Marcelo; Zak, Marcelo

2009-10-01

119

Deep Reaching Gas-permeable Tectonic Faults of the Early Earth as Habitats for the Origin of Life  

NASA Astrophysics Data System (ADS)

The discussion on the origin of life encounters difficulties when it comes to estimate the conditions of the early earth and to define plausible environments for the development of the first complex organic molecules. Until now, the role of the earth's crust has been more or less ignored. First continental crustal cores may have been developed some tens to hundreds of million years after formation of earth. Due to tectonic stress the proto continents were sheared by vertical strike-slip faults at an early stage. These deep-reaching open, interconnected tectonic faults may provide possible reaction habitats ranging from nano- to centimetre and even larger dimensions that sum up to several cubic kilometres for the formation of prebiotic molecules. Their fillings consist of supercritical and subcritical waters and supercritical and subcritical gases. Here, all necessary raw materials including phosphate for the development of prebiotic molecules exist in variable concentrations and in sufficient quantities. Furthermore, there are periodically changing pressure and temperature conditions, varying pH-values, metallic surfaces, clay minerals and a large number of catalysts. While cosmic and UV-radiation are excluded, nuclear radiation intervenes the chemical evolution of the molecules inside the crust. Carbon dioxide (CO2) is of crucial importance. It can be present in an almost pure form as a supercritical fluid (scCO2) in a crustal depth less than 1 km (critical point of pure CO2: 74 bar; 31°C). Inside strike-slip faults, a two-phase system formed by supercritical CO2 in liquid water provides the environment for condensation and polymerisation of hydrogen cyanide, nucleobases, nucleotides and amino acids. ScCO2 is a non-polar solvent that is widely used in "green chemistry" (Anastas and Kirchhoff 2002) and enables the dissolution of non-polar reactants and their reactions normally occurring in the absence of water. Under the influence of periodically changing conditions (extreme earth tides played an important role for cyclic variations within the fluid-water-interface and for the development of gradients), the reaction products can be transferred into a neighbouring aqueous environment. Based on these conditions, prebiotic molecules could have been condensed to long-chained molecules, from which first cell structures could have been formed by chemical evolution. This hypothetical model for the origin of life can be used to design crucial experiments for the model's verification. Because all proposed processes could still occur in tectonic faults at the present time, it may be possible to detect and analyse the formation of prebiotic molecules in order to assess the validity of the proposed hypothesis. A clear indication of the geological provenience of corresponding organic substances arises, if these substances appear in racemic mixtures (e.g. d- and l-alanin), making them distinguishable from similar molecules of biological origin. Additionally, their isotopic composition can help to exclude a possible biological origin. Further on, the possible detection of these substances in fluid inclusions of quartz dykes of former deep crustal parts is another possible proof of the hypothesis. Keywords: origin, life, strike-slip faults, scCO2, prebiotic molecules

Schreiber, U.; Mayer, C.

2012-04-01

120

Bird Conservation International (2000) 10:289303. BirdLife International 2000 Comparing endemism and habitat  

E-print Network

and habitat restriction in Mesoamerican tropical deciduous forest birds: implications for biodiversity in an attempt to identify all bird species critically dependent on tropical deciduous forests of western Mexico endemics, 59 corridor species and 3 seasonal endemics associated with tropical deciduous forest (TDF

Ornelas Rodríguez, Juan Francisco - INECOL

121

Diversity and habitat relationships of hypogeous fungi. III. Factors influencing the occurrence of fire-adapted species.  

PubMed

Among the huge array of hypogeous ectomycorrhizal fungi so far documented from Australia, six genera and more than 30 species occur within the family Mesophelliaceae, all of which show various adaptations for surviving in fire-prone landscapes. These mostly endemic fungi are critical to postfire reestablishment of regenerating vegetation, and their fruit-bodies provide essential food resources for diverse ground-dwelling fauna. We developed habitat models for five common representatives of the Mesophelliaceae based on repeat collections of their fruit-bodies from 136 study plots situated along a series of environmental gradients across the south-eastern mainland of Australia. At a meso- or landscape scale, temperature influenced the occurrence of Castoreum radicatum, Mesophellia clelandii and Nothocastoreum cretaceum, with the type of response varying. Below a threshold, C. radicatum preferred sites with cooler mean annual temperatures. In contrast, M. clelandii and N. cretaceum had optimal ranges of temperature, above and below which the probability of detecting them dropped. Also at a landscape scale, C. radicatum was more likely to be detected at sites with lower levels of precipitation during the driest quarter of the year. At a micro-site scale, M. clelandii and N. cretaceum were more likely to occur in stands with an intermediate number of host eucalypt stems, likely relating to successional age of the stand. Sites with a higher number of large fallen trees were more likely to have N. cretaceum, while sites with intermediate litter depths were more likely to have C. radicatum and M. clelandii. Mesophellia glauca and M. trabalis showed no consistent patterns. They are apparently the most broadly adaptable in terms of the independent variables tested. Although fire has been previously suggested to be heavily implicated in the life cycle of several members of the Mesophelliaceae, we found no relationship between time since disturbance by fire and other factors and likelihood of occurrence. Instead, other habitat attributes appeared to be more important in explaining their distribution. The complex and differing responses of the species of Mesophelliaceae studied here, to features of their environment, reinforce the need to manage multiple-use forest landscapes across the region for a diversity of attributes. PMID:19269321

Claridge, Andrew W; Trappe, James M; Mills, Douglas J; Claridge, Debbie L

2009-01-01

122

The influence of hydrogeomorphic dynamics on fish habitat: A case study using the ooCAESAR landscape evolution model  

NASA Astrophysics Data System (ADS)

The sediments, morphological features and riverflows that define the hydrogeomorphology of natural river channels provide physical habitat diversity that sustains the aquatic biodiversity of river ecosystems. This simple concept underpins the large number of contemporary ecohydraulic models that are available in the literature. Such models have been widely used to predict how morphological diversity (taken here to encompass channel sediments, topography and flow velocity) influences habitat quality for target species at the reach scale. The accuracy of these predictions is a matter of considerable practical importance, as the results are frequently used as the basis for restoration or rehabilitation. However, such models are limited in that they do not account for dynamic changes in river morphology, which themselves are triggered by changes in the flows of water and sediment delivered from the watershed upstream and stimulated by climatic, tectonic or land cover perturbations across a wide range of temporal scales. Accordingly there is an urgent need to combine the outputs of catchment-based geomorphological models with ecohydraulic models, so that predictions of habitat quality focused on specific reaches can be placed into their appropriate (i.e., the watershed) spatial context. To address these issues we herein present preliminary simulations from a case study of the Sulphur Creek watershed, a 24.2 sq. km., third-order catchment draining one of 47 tributaries to the Napa River, which empties southerly into the San Francisco Bay of northern California. Therein, the influence of catchment-scale geomorphic dynamics on reach-scale fish habitat is investigated using the ooCAESAR landscape evolution model. This cellular automaton model, based on its predecessor CAESAR, was chosen because it can be run at spatial resolutions (1 to 5 m.) that are ecologically meaningful and at temporal resolutions that capture both individual event dynamics and long-term evolutionary history. Water depths, velocities and surface grain size distributions produced by the ooCAESAR simulations are used to model habitat suitability for spawning and rearing lifestages of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus mykiss) using traditional habitat suitability curves. To drive the simulations, scenarios were developed that express a combination of plausible future events and time series based on climate (rainfall), land use, restoration and seismic variants. A subset of an ensemble of scenario-driven simulations are used to illustrate how non-linear catchment-scale dynamics influence the quality of fish habitat expressed at the reach-scale, in sometimes non-intuitive ways. Sediment budgets derived from the simulations help segregate processes and explain how the delivery and storage of sediment within the catchment combine to change physical habitat in reaches utilized by fish.

Wheaton, J. M.; Sear, D. A.; Darby, S. E.; Booker, D. E.; Acreman, M.

2005-12-01

123

Does habitat heterogeneity in a multi-use landscape influence survival rates and density of a native mesocarnivore?  

PubMed

The relationships between predators, prey, and habitat have long been of interest to applied and basic ecologists. As a native Great Plains mesocarnivore of North America, swift foxes (Vulpes velox) depended on the historic disturbance regime to maintain open grassland habitat. With a decline in native grasslands and subsequent impacts to prairie specialists, notably the swift fox, understanding the influence of habitat on native predators is paramount to future management efforts. From 2001 to 2004, we investigated the influence of vegetation structure on swift fox population ecology (survival and density) on and around the Piñon Canyon Maneuver Site, southeastern Colorado, USA. We monitored 109 foxes on 6 study sites exposed to 3 different disturbance regimes (military training, grazing, unused). On each site we evaluated vegetation structure based on shrub density, basal coverage, vegetation height, and litter. Across all sites, annual fox survival rates ranged from 0.50 to 0.92 for adults and 0.27 to 0.78 for juveniles. Among sites, population estimates ranged from 1 to 7 foxes per 10 km transect. Fox density or survival was not related to the relative abundance of prey. A robust model estimating fox population size and incorporating both shrub density and percent basal cover as explanatory variables far outperformed all other models. Our results supported the idea that, in our region, swift foxes were shortgrass prairie specialists and also indicated a relationship between habitat quality and landscape heterogeneity. We suggest the regulation of swift fox populations may be based on habitat quality through landscape-mediated survival, and managers may effectively use disturbance regimes to create or maintain habitat for this native mesocarnivore. PMID:24963713

Gese, Eric M; Thompson, Craig M

2014-01-01

124

Does Habitat Heterogeneity in a Multi-Use Landscape Influence Survival Rates and Density of a Native Mesocarnivore?  

PubMed Central

The relationships between predators, prey, and habitat have long been of interest to applied and basic ecologists. As a native Great Plains mesocarnivore of North America, swift foxes (Vulpes velox) depended on the historic disturbance regime to maintain open grassland habitat. With a decline in native grasslands and subsequent impacts to prairie specialists, notably the swift fox, understanding the influence of habitat on native predators is paramount to future management efforts. From 2001 to 2004, we investigated the influence of vegetation structure on swift fox population ecology (survival and density) on and around the Piñon Canyon Maneuver Site, southeastern Colorado, USA. We monitored 109 foxes on 6 study sites exposed to 3 different disturbance regimes (military training, grazing, unused). On each site we evaluated vegetation structure based on shrub density, basal coverage, vegetation height, and litter. Across all sites, annual fox survival rates ranged from 0.50 to 0.92 for adults and 0.27 to 0.78 for juveniles. Among sites, population estimates ranged from 1 to 7 foxes per 10 km transect. Fox density or survival was not related to the relative abundance of prey. A robust model estimating fox population size and incorporating both shrub density and percent basal cover as explanatory variables far outperformed all other models. Our results supported the idea that, in our region, swift foxes were shortgrass prairie specialists and also indicated a relationship between habitat quality and landscape heterogeneity. We suggest the regulation of swift fox populations may be based on habitat quality through landscape-mediated survival, and managers may effectively use disturbance regimes to create or maintain habitat for this native mesocarnivore. PMID:24963713

Gese, Eric M.; Thompson, Craig M.

2014-01-01

125

Hunting influences the diel patterns in habitat selection by northern pintails Anas acuta  

USGS Publications Warehouse

Northern pintail Anas acuta (hereafter pintail) populations wintering within Suisun Marsh, a large estuarine managed wetland near San Francisco Bay, California,USA, have declined markedly over the last four decades. The reasons for this decline are unclear. Information on how hunting and other factors influence the selection of vegetation types and sanctuaries would be beneficial to manage pintail populations in SuisunMarsh. During 1991-1993, we radio-marked and relocated female pintails (individuals: N = 203, relocations: N = 7,688) within Suisun Marsh to investigate habitat selection during the non-breeding months (winter). We calculated selection ratios for different vegetation types and for sanctuaries, and examined differences in those ratios between hunting season (i.e. hunting and non-hunting), age (hatchyear and after-hatch-year), and time of day (daylight or night hours). We found that diel patterns in selection were influenced by hunting disturbance. For example, prior to the hunting season and during daylight hours, pintails selected areas dominated by brass buttons Cotula coronopifolia, a potentially important food source, usually outside of sanctuary boundaries. However, during the hunting season, pintails did not select brass buttons during daylight hours, but instead highly selected permanent pools, mostly within sanctuaries. Also, during the hunting season, pintails showed strong selection for brass buttons at night. Sanctuaries provided more area of permanent water pools than within hunting areas and appeared to function as important refugia during daylight hours of the hunting season. Wildlife managers should encourage large protected permanent pools adjacent to hunted wetlands to increase pintail numbers within wetland environments and responsibly benefit hunting opportunities while improving pintail conservation.

Casazza, Michael L.; Coates, Peter S.; Miller, Michael R.; Overton, Cory T.; Yparraguirre, Daniel R.

2012-01-01

126

Habitat context influences predator interference interactions and the strength of resource partitioning  

Microsoft Academic Search

Despite increasing evidence that habitat structure can shape predator–prey interactions, few studies have examined the impact of habitat context on interactions among multiple predators and the consequences for combined foraging rates. We investigated the individual and combined effects of stone crabs (Menippe mercenaria) and knobbed whelks (Busycon carica) when foraging on two common bivalves, the hard clam (Mercenaria mercenaria) and

A. Randall Hughes; Jonathan H. Grabowski

2006-01-01

127

Spawning Distribution of Sockeye Salmon in a Glacially Influenced Watershed: The Importance of Glacial Habitats  

Microsoft Academic Search

The spawning distribution of sockeye salmon Oncorhynchus nerka was compared between clear and glacially turbid habitats in Lake Clark, Alaska, with the use of radiotelemetry. Tracking of 241 adult sockeye salmon to 27 spawning locations revealed both essential habitats and the relationship between spawn timing and seasonal turbidity cycles. Sixty-six percent of radio-tagged sockeye salmon spawned in turbid waters (?5

Daniel B. Young; Carol Ann Woody

2007-01-01

128

Respective influence of habitat conditions and management regimes on prealpine calcareous grasslands  

Microsoft Academic Search

The calcareous grasslands of the south-western French Alps have been poorly studied, although they provide suitable habitat for rare plant species and communities. The separate and combined effects on calcareous grassland communities of habitat conditions (lithology, soil moisture) and management regimes (grazing intensity, cutting regime) were studied using constrained ordination techniques (canonical correspondence analysis with variance partitioning). Among the explanatory

Luc Barbaro; Thierry Dutoit; Fabien Anthelme; Emmanuel Corcket

2004-01-01

129

Salmon Life Histories, Habitat, and Food Webs in the Columbia River Estuary: An Overview of Research Results, 2002-2006.  

SciTech Connect

From 2002 through 2006 we investigated historical and contemporary variations in juvenile Chinook salmon Oncorhynchus tshawytscha life histories, habitat associations, and food webs in the lower Columbia River estuary (mouth to rkm 101). At near-shore beach-seining sites in the estuary, Chinook salmon occurred during all months of the year, increasing in abundance from January through late spring or early summer and declining rapidly after July. Recently emerged fry dispersed throughout the estuary in early spring, and fry migrants were abundant in the estuary until April or May each year. Each spring, mean salmon size increased from the tidal freshwater zone to the estuary mouth; this trend may reflect estuarine growth and continued entry of smaller individuals from upriver. Most juvenile Chinook salmon in the mainstem estuary fed actively on adult insects and epibenthic amphipods Americorophium spp. Estimated growth rates of juvenile Chinook salmon derived from otolith analysis averaged 0.5 mm d-1, comparable to rates reported for juvenile salmon Oncorhynchus spp. in other Northwest estuaries. Estuarine salmon collections were composed of representatives from a diversity of evolutionarily significant units (ESUs) from the lower and upper Columbia Basin. Genetic stock groups in the estuary exhibited distinct seasonal and temporal abundance patterns, including a consistent peak in the Spring Creek Fall Chinook group in May, followed by a peak in the Western Cascades Fall Chinook group in July. The structure of acanthocephalan parasite assemblages in juvenile Chinook salmon from the tidal freshwater zone exhibited a consistent transition in June. This may have reflected changes in stock composition and associated habitat use and feeding histories. From March through July, subyearling Chinook salmon were among the most abundant species in all wetland habitat types (emergent, forested, and scrub/shrub) surveyed in the lower 100 km of the estuary. Salmon densities within wetland habitats fell to low levels by July, similar to the pattern observed at mainstem beach-seining sites and coincident with high water temperatures that approached or exceeded 19 C by mid-summer. Wetland habitats were used primarily by small subyearling Chinook salmon, with the smallest size ranges (i.e., rarely exceeding 70 mm by the end of the wetland rearing season) at scrub/shrub forested sites above rkm 50. Wetland sites of all types were utilized by a diversity of genetic stock groups, including less abundant groups such as Interior Summer/Fall Chinook.

Bottom, Daniel L.; Anderson, Greer; Baptisa, Antonio

2008-08-01

130

Influences of human and livestock density on winter habitat selection of Mongolian gazelle (Procapra gutturosa).  

PubMed

Human and livestock related disturbances of habitat selection by ungulates are topics of global concern, as they have profound impacts on ungulate survival, population density, fitness, and management; however, differences in ungulate habitat use under different human and livestock densities are not fully understood. Mongolian gazelle (Procapra gutturosa), an endemic ungulate species on the Asia-European steppe, faces varying intensities of human and livestock disturbances in the area around Dalai Lake, China. To investigate how habitat selection strategies vary as disturbance intensity changes, we randomly set 20 transects containing 1486 plots, on which we conducted repeated surveys of 21 ecological factors during the winters in the period of 2005-2008. We aimed to: 1) determine the critical factors underlying habitat selection of the gazelles; 2) determine the gazelles' habitat preferences in this area; 3) determine how habitat selection varies with disturbance intensity and explore the primary underlying mechanism. We used binary-logistic regressions and information theoretic approaches to build best-fit habitat selection models, and calculated resource selection functions. Sixty-six herds, 522 individuals, and 499 tracks were recorded. Our results indicate that snow depth and aboveground biomass are the main factors affecting habitat selection by Mongolian gazelle throughout the district in winter. Thin snow cover and abundant aboveground biomass are preferred. Avoiding disturbance was the primary factor accounting for habitat selection in low disturbance areas, although with increasing human or live-stock-related disturbance, gazelle maintained a reduced distance to the source of the disturbance. Presumably owing to that shift, movement costs were more important as disturbance increased. In addition, Mongolian gazelle selected habitats based on topographical features promoting greater visibility where disturbance was lower. We suggest several management implications of our findings for this ungulate species will contribute to the effective conservation of Mongolian gazelle in the Dalai Lake area. PMID:24410492

Luo, Zhenhua; Liu, Bingwan; Liu, Songtao; Jiang, Zhigang; Halbrook, Richard S

2014-01-01

131

Influence of seasonal forcing on habitat use by bottlenose dolphins Tursiops truncatus in the Northern Adriatic Sea  

Microsoft Academic Search

Bottlenose dolphins are the only cetaceans regularly observed in the northern Adriatic Sea, but they survive at low densities\\u000a and are exposed to significant threats. This study investigates some of the factors that influence habitat use by the animals\\u000a in a largely homogeneous environment by combining dolphin data with hydrological and physiographical variables sampled from\\u000a oceanographic ships. Surveys were conducted

Giovanni Bearzi; Arianna Azzellino; Elena Politi; Marina Costa; Mauro Bastianini

2008-01-01

132

The Influence of Social Structure, Habitat, and Host Traits on the Transmission of Escherichia coli in Wild Elephants  

PubMed Central

Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental, and host-related factors that influence transmission patterns. PMID:24705319

Chiyo, Patrick I.; Grieneisen, Laura E.; Wittemyer, George; Moss, Cynthia J.; Lee, Phyllis C.; Douglas-Hamilton, Iain; Archie, Elizabeth A.

2014-01-01

133

An online algorithm for temperature influenced fatigue–life estimation: strain–life approach  

Microsoft Academic Search

This paper presents an online temperature modified strain–life approach based on temperature modified pseudo-elastic stress filtering and rainflow counting. Local temperature–stress–strain behaviour is modelled with an operator of the Prandtl type. The hysteresis loops are supposed to be stabilized and no creep is considered. To gain material parameters at temperatures not measured, linear parameter interpolation is introduced. Temperature influence upon

Marko Nagode; Frank Zingsheim

2004-01-01

134

Wavelength-specific photosynthetic responses of Halophila johnsonii from marine-influenced versus river-influenced habitats  

Microsoft Academic Search

The seagrass Halophila johnsonii Eiseman grows from the upper intertidal to 3m depths in habitats ranging from near-marine inlets to tidal riverine. These habitats have distinct optical characteristics, primarily due to variable concentrations of watershed-derived chromophoric dissolved organic matter (CDOM), which increases the attenuation of short-wavelength (blue and UV) light. H. johnsonii contains a suite of flavonoids that are thought

Amanda E. Kahn; Michael J. Durako

2009-01-01

135

Floral and nesting resources, habitat structure, and fire influence bee distribution across an open-forest gradient  

USGS Publications Warehouse

Given bees' central effect on vegetation communities, it is important to understand how and why bee distributions vary across ecological gradients. We examined how plant community composition, plant diversity, nesting suitability, canopy cover, land use, and fire history affected bee distribution across an open-forest gradient in northwest Indiana, USA, a gradient similar to the historic Midwest United States landscape mosaic. When considered with the other predictors, plant community composition was not a significant predictor of bee community composition. Bee abundance was negatively related to canopy cover and positively to recent fire frequency, bee richness was positively related to plant richness and abundance of potential nesting resources, and bee community composition was significantly related to plant richness, soil characteristics potentially related to nesting suitability, and canopy cover. Thus, bee abundance was predicted by a different set of environmental characteristics than was bee species richness, and bee community composition was predicted, in large part, by a combination of the significant predictors of bee abundance and richness. Differences in bee community composition along the woody vegetation gradient were correlated with relative abundance of oligolectic, or diet specialist, bees. Because oligoleges were rarer than diet generalists and were associated with open habitats, their populations may be especially affected by degradation of open habitats. More habitat-specialist bees were documented for open and forest/scrub habitats than for savanna/woodland habitats, consistent with bees responding to habitats of intermediate woody vegetation density, such as savannas, as ecotones rather than as distinct habitat types. Similarity of bee community composition, similarity of bee abundance, and similarity of bee richness between sites were not significantly related to proximity of sites to each other. Nestedness analysis indicated that species composition in species-poor sites was not merely a subset of species composition at richer sites. The lack of significant proximity or nestedness effects suggests that factors at a small spatial scale strongly influence bees' use of sites. The findings indicate that patterns of plant diversity, nesting resource availability, recent fire, and habitat shading, present at the scale of a few hundred meters, are key determinants of bee community patterns in the mosaic open-savanna-forest landscape. ?? 2010 by the Ecological Society of America.

Grundel, R.; Jean, R.P.; Frohnapple, K.J.; Glowacki, G.A.; Scott, P.E.; Pavlovic, N.B.

2010-01-01

136

Bull Trout Life History, Genetics, Habitat Needs, and Limiting Fact in Central and Northeast Oregon. Annual Report 1999.  

SciTech Connect

This section describes work accomplished in 1999 that continued to address two objectives of this project. These objectives are (1) determine the distribution of juvenile and adult bull trout Salvelinus confluentus and habitats associated with that distribution, and (2) determine fluvial and resident bull trout life history patterns. Completion of these objectives is intended through studies of bull trout in the Grande Ronde, Walla Walla, and John Day basins. These basins were selected because they provide a variety of habitats, from relatively degraded to pristine, and bull trout populations were thought to vary from relatively depressed to robust. In all three basins we used radio telemetry to determine the seasonal movements of bull trout. In the John Day and Walla Walla basins we also used traps to capture migrant bull trout. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, determine the relative abundance, size and age of migrant fish, and capture bull trout to be implanted with radio transmitters. In the John Day basin, we captured adult and juvenile bull trout from the upper John Day River and its tributaries, Call Creek, Reynolds Creek, and Roberts Creek. In the Walla Walla basin, we captured adult and juvenile bull trout from Mill Creek.

Hemmingsen, Alan R.; Gunckel, Stephanie L.; Howell, Philip J.

2001-08-01

137

Searching for microbial life remotely: Satellite-to-rover habitat mapping in the Atacama Desert, Chile  

Microsoft Academic Search

The Atacama Desert, one of the most arid landscapes on Earth, serves as an analog for the dry conditions on Mars and as a test bed in the search for life on other planets. During the Life in the Atacama (LITA) 2004 field experiment, satellite imagery and ground-based rover data were used in concert with a `follow-the-water' exploration strategy to

K. Warren-Rhodes; S. Weinstein; J. Dohm; J. Piatek; E. Minkley; A. Hock; C. Cockell; D. Pane; L. A. Ernst; G. Fisher; S. Emani; A. S. Waggoner; N. A. Cabrol; D. S. Wettergreen; D. Apostolopoulos; P. Coppin; E. Grin; Chong Diaz; J. Moersch; G. G. Oril; T. Smith; K. Stubbs; G. Thomas; M. Wagner; M. Wyatt

2007-01-01

138

Searching for microbial life remotely: Satellite-to-rover habitat mapping in the Atacama Desert, Chile  

Microsoft Academic Search

The Atacama Desert, one of the most arid landscapes on Earth, serves as an analog for the dry conditions on Mars and as a test bed in the search for life on other planets. During the Life in the Atacama (LITA) 2004 field experiment, satellite imagery and ground-based rover data were used in concert with a ‘follow-the-water’ exploration strategy to

K. Warren-Rhodes; S. Weinstein; J. Dohm; J. Piatek; E. Minkley; A. Hock; C. Cockell; D. Pane; L. A. Ernst; G. Fisher; S. Emani; A. S. Waggoner; N. A. Cabrol; D. S. Wettergreen; D. Apostolopoulos; P. Coppin; E. Grin; Chong Diaz; J. Moersch; G. G. Oril; T. Smith; K. Stubbs; G. Thomas; M. Wagner; M. Wyatt

2007-01-01

139

THE INFLUENCE OF SUBURBAN LAND USE ON HABITAT AND BIOTIC INTEGRITY OF COASTAL RHODE ISLAND STREAMS  

EPA Science Inventory

Watershed land use in suburban areas can affect stream biota through degradation of instream habitat, water quality, and riparian vegetation. By monitoring stream biotic communities in various geographic regions, we can better understand and conserve our watershed ecosystems. The...

140

Quantifying The Influence Of Time-Since-Creation On Benthic Secondary Production In Created Coastal Habitats  

EPA Science Inventory

Wetland creation, enhancement, and restoration activities are commonly implemented to compensate for wetland loss or degradation in freshwater and coastal ecosystems. While assessments on structural condition are common in monitoring habitat restoration, functional equivalence i...

141

Factors influencing farmland habitat use by shorebirds wintering in the Fraser River Delta, Canada  

Microsoft Academic Search

Like many other coastal regions of the world, open-soil agricultural lands in the Fraser River Delta provide roosting and feeding habitat for non-breeding shorebirds that supplements intertidal habitat. Focusing on dunlin (Calidris alpina pacifica), black-bellied plover (Pluvialis squatorola), killdeer (Charadrius vociferus), and their avian predators (raptors), diurnal and nocturnal high tide surveys were conducted across the non-breeding period, October–April (1998–2000).

Lesley J. Evans Ogden; Shabtai Bittman; David B. Lank; F. Craig Stevenson

2008-01-01

142

Health Related Quality of Life and Influencing Factors among Welders  

PubMed Central

Background Occupational exposure to welding fumes is a serious occupational health problem all over the world. Welders are exposed to many occupational hazards; these hazards might cause some occupational diseases. The aim of the study was to assess the health related quality of life (HRQL) of electric welders in Shanghai China and explore influencing factors to HRQL of welders. Methods 301 male welders (without pneumoconiosis) and 305 non-dust male workers in Shanghai were enrolled in this study. Short Form-36 (SF-36) health survey questionnaires were applied in this cross-sectional study. Socio-demographic, working and health factors were also collected. Multiple stepwise regress analysis was used to identify significant factors related to the eight dimension scores. Results Six dimensions including role-physical (RP), bodily pain (BP), general health (GH), validity (VT), social function (SF), and mental health (MH) were significantly worse in welders compared to non-dust workers. Multiple stepwise regress analysis results show that native place, monthly income, quantity of children, drinking, sleep time, welding type, use of personal protective equipment (PPE), great events in life, and some symptoms including dizziness, discomfort of cervical vertebra, low back pain, cough and insomnia may be influencing factors for HRQL of welders. Among these factors, only sleep time and the use of PPE were salutary. Conclusions Some dimensions of HRQL of these welders have been affected. Enterprises which employ welders should take measures to protect the health of these people and improve their HRQL. PMID:25048102

Qin, Jingxiang; Liu, Wuzhong; Zhu, Jun; Weng, Wei; Xu, Jiaming; Ai, Zisheng

2014-01-01

143

Natural and anthropogenic influences on a red-crowned crane habitat in the Yellow River Delta Natural Reserve, 1992-2008.  

PubMed

This study aims to assess the relative importance of natural and anthropogenic variables on the change of the red-crowned crane habitat in the Yellow River Nature Reserve, East China using multitempopral remote sensing and geographic information system. Satellite images were used to detect the change in potential crane habitat, from which suitable crane habitat was determined by excluding fragmented habitat. In this study, a principal component analysis (PCA) with seven variables (channel flow, rainfall, temperature, sediment discharge, number of oil wells, total length of roads, and area of settlements) and linear regression analyses of potential and suitable habitat against the retained principal components were applied to explore the influences of natural and anthropogenic factors on the change of the red-crowned crane habitat. The experimental results indicate that suitable habitat decreased by 5,935 ha despite an increase of 1,409 ha in potential habitat from 1992 to 2008. The area of crane habitat changed caused by natural drivers such as progressive succession, retrogressive succession, and physical fragmentation is almost the same as that caused by anthropogenic forces such as land use change and behavioral fragmentation. The PCA and regression analyses revealed that natural factors (e.g., channel flow, rainfall, temperature, and sediment discharge) play an important role in the crane potential habitat change and human disturbances (e.g., oil wells, roads, and settlements) jointly explain 51.8 % of the variations in suitable habitat area, higher than 48.2 % contributed by natural factors. Thus, it is vital to reduce anthropogenic influences within the reserve in order to reverse the decline in the suitable crane habitat. PMID:24526617

Wang, Hong; Gao, Jay; Pu, Ruiliang; Ren, Liliang; Kong, Yan; Li, He; Li, Ling

2014-07-01

144

Personality in its natural habitat: manifestations and implicit folk theories of personality in daily life.  

PubMed

To examine the expression of personality in its natural habitat, the authors tracked 96 participants over 2 days using the Electronically Activated Recorder (EAR), which samples snippets of ambient sounds in participants' immediate environments. Participants' Big Five scores were correlated with EAR-derived information on their daily social interactions, locations, activities, moods, and language use; these quotidian manifestations were generally consistent with the trait definitions and (except for Openness) often gender specific. To identify implicit folk theories about daily manifestations of personality, the authors correlated the EAR-derived information with impressions of participants based on their EAR sounds; judges' implicit folk theories were generally accurate (especially for Extraversion) and also partially gender specific. The findings point to the importance of naturalistic observation studies on how personality is expressed and perceived in the natural stream of everyday behavior. PMID:16737378

Mehl, Matthias R; Gosling, Samuel D; Pennebaker, James W

2006-05-01

145

Influence of monsoon-related riparian phenology on yellow-billed cuckoo habitat selection in Arizona  

USGS Publications Warehouse

Aim: The western yellow-billed cuckoo (Coccyzus americanus occidentalis), a Neotropical migrant bird, is facing steep population declines in its western breeding grounds owing primarily to loss of native habitat. The favoured esting habitat for the cuckoo in the south-western United States is low-elevation riparian forests and woodlands. Our aim was to explore relationships between vegetation phenology patterns captured by satellite phenometrics and the distribution of the yellow-billed cuckoo, and to use this information to map cuckoo habitat. Location: Arizona, USA. Methods: Land surface phenometrics were derived from satellite Advanced Very High-Resolution Radiometer (AVHRR), bi-weekly time-composite, ormalized difference vegetation index (NDVI) data for 1998 and 1999 at a resolution of 1 km. Fourier harmonics were used to analyse the waveform of the annual NDVI profile in each pixel. To create the models, we coupled 1998 satellite phenometrics with 1998 field survey data of cuckoo presence or absence and with point data that sampled riparian and cottonwood–willow vegetation types. Our models were verified and refined using field and satellite data collected in 1999. Results: The models reveal that cuckoos prefer areas that experience peak greenness 29 days later, are 36% more dynamic and slightly (< 1%) more productive than their average cottonwood–willow habitat. The results support a scenario in which cuckoos migrate northwards, following the greening of riparian corridors and surrounding landscapes in response to monsoon precipitation, but then select a nesting site based on optimizing the near-term foraging potential of the neighbourhood. Main conclusions: The identification of preferred phenotypes within recognized habitat can be used to refine future habitat models, inform habitat response to climate change, and suggest adaptation strategies. For example, models of phenotype preferences can guide management actions by identifying and prioritizing for conservation those landscapes that reliably exhibit highly preferred phenometrics on a consistent basis.

Wallace, Cynthia S.A.; Villarreal, Miguel; Van Riper, Charles

2013-01-01

146

Hatching phenology, life history and egg bank size of fairy shrimp Branchipodopsis spp. (Branchiopoda, Crustacea) in relation to the ephemerality of their rock pool habitat  

Microsoft Academic Search

In temporary aquatic habitats, permanence and the severe disturbance associated with desiccation are strong selective agents\\u000a expected to lead to differentiation in life history strategies in populations experiencing different disturbance regimes.\\u000a Besides optimal timing of hatching of dormant life stages, maturation and reproduction, pool inhabitants also benefit from\\u000a the acquisition of reliable cues for the quality of the ambient environment.

Bram Vanschoenwinkel; Maitland Seaman; Luc Brendonck

2010-01-01

147

?-Diversity and Species Accumulation in Antarctic Coastal Benthos: Influence of Habitat, Distance and Productivity on Ecological Connectivity  

PubMed Central

High Antarctic coastal marine environments are comparatively pristine with strong environmental gradients, which make them important places to investigate biodiversity relationships. Defining how different environmental features contribute to shifts in ?-diversity is especially important as these shifts reflect both spatio-temporal variations in species richness and the degree of ecological separation between local and regional species pools. We used complementary techniques (species accumulation models, multivariate variance partitioning and generalized linear models) to assess how the roles of productivity, bio-physical habitat heterogeneity and connectivity change with spatial scales from metres to 100's of km. Our results demonstrated that the relative importance of specific processes influencing species accumulation and ?–diversity changed with increasing spatial scale, and that patterns were never driven by only one factor. Bio-physical habitat heterogeneity had a strong influence on ?-diversity at scales <290 km, while the effects of productivity were low and significant only at scales >40 km. Our analysis supports the emphasis on the analysis of diversity relationships across multiple spatial scales and highlights the unequal connectivity of individual sites to the regional species pool. This has important implications for resilience to habitat loss and community homogenisation, especially for Antarctic benthic communities where rates of recovery from disturbance are slow, there is a high ratio of poor-dispersing and brooding species, and high biogenic habitat heterogeneity and spatio-temporal variability in primary production make the system vulnerable to disturbance. Consequently, large areas need to be included within marine protected areas for effective management and conservation of these special ecosystems in the face of increasing anthropogenic disturbance. PMID:20689578

Thrush, Simon F.; Hewitt, Judi E.; Cummings, Vonda J.; Norkko, Alf; Chiantore, Mariachiara

2010-01-01

148

Local habitat and landscape influence predation of bird nests on afforested Mediterranean cropland  

NASA Astrophysics Data System (ADS)

Afforestation programs such as the one promoted by the EU Common Agrarian Policy have contributed to spread tree plantations on former cropland. Nevertheless these afforestations may cause severe damage to open habitat species, especially birds of high conservation value. We investigated predation of artificial bird nests at young tree plantations and at the open farmland habitat adjacent to the tree plantations in central Spain. Predation rates were very high at both tree plantations (95.6%) and open farmland habitat (94.2%) after two and three week exposure. Plantation edge/area ratio and development of the tree canopy decreased predation rates and plantation area and magpie (Pica pica) abundance increased predation rates within tree plantations, which were also affected by land use types around plantations. The area of nearby tree plantations (positive effect), distance to the tree plantation edge (negative effect), and habitat type (mainly attributable to the location of nests in vineyards) explained predation rates at open farmland habitat. We conclude that predation rates on artificial nests were particularly high and rapid at or nearby large plantations, with high numbers of magpies and low tree development, and located in homogenous landscapes dominated by herbaceous crops and pastures with no remnants of semi-natural woody vegetation. Landscape planning should not favour tree plantations as the ones studied here in Mediterranean agricultural areas that are highly valuable for ground-nesting bird species.

Sánchez-Oliver, J. S.; Rey Benayas, J. M.; Carrascal, L. M.

2014-07-01

149

Influence of early-life nutrition on mortality and reproductive success during a subsequent famine  

E-print Network

-life conditions, no study on humans has demonstrated the predicted fitness benefit under low later-life nutrition of metabolic diseases. developmental plasticity | silver spoon | human life-history | DoHAD Nutrition duringInfluence of early-life nutrition on mortality and reproductive success during a subsequent famine

Lummaa, Virpi

150

Processes on the Young Earth and the Habitats of Early Life  

NASA Astrophysics Data System (ADS)

Conditions at the surface of the young (Hadean and early Archean) Earth were suitable for the emergence and evolution of life. After an initial hot period, surface temperatures in the late Hadean may have been clement beneath an atmosphere containing greenhouse gases over an ocean-dominated planetary surface. The first crust was mafic and it internally melted repeatedly to produce the felsic rocks that crystallized the Jack Hills zircons. This crust was destabilized during late heavy bombardment. Plate tectonics probably started soon after and had produced voluminous continental crust by the mid Archean, but ocean volumes were sufficient to submerge much of this crust. In the Hadean and early Archean, hydrothermal systems around abundant komatiitic volcanism may have provided suitable sites to host the earliest living communities and for the evolution of key enzymes. Evidence from the Isua Belt, Greenland, suggests life was present by 3.8 Gya, and by the mid-Archean, the geological record both in the Pilbara in Western Australia and the Barberton Greenstone Belt in South Africa shows that microbial life was abundant, probably using anoxygenic photosynthesis. By the late Archean, oxygenic photosynthesis had evolved, transforming the atmosphere and permitting the evolution of eukaryotes.

Arndt, Nicholas T.; Nisbet, Euan G.

2012-05-01

151

Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use  

USGS Publications Warehouse

Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research.

Larson, James H.; Richardson, William B.; Knights, Brent C.; Bartsch, Lynn A.; Bartsch, Michelle R.; Nelson, John C.; Veldboom, Jason A.; Vallazza, Jonathan M.

2013-01-01

152

Diversification of Lupinus (Leguminosae) in the western New World: derived evolution of perennial life history and colonization of montane habitats.  

PubMed

Previous phylogenetic studies of Lupinus (Leguminosae) based on nuclear DNA have shown that the western New World taxa form a monophyletic group representing the majority of species in the genus, with evidence for high rates of recent diversification in South America following final uplift of the Andes 2-4 million years ago (Mya). For this study, three regions of rapidly evolving non-coding chloroplast DNA (trnL intron, trnS-trnG, and trnT-trnL) were examined to estimate the timing and rates of diversification in the western New World, and to infer ancestral states for geographic range, life history, and maximum elevation. The western New World species (5.0-9.3Mya, 0.6-1.1 spp./My) comprise a basally branching assemblage of annual plants endemic to the lower elevations of western North America, from which two species-rich clades are recently derived: (i) the western North American perennials from the Rocky Mountains, Great Basin, and Pacific Slope (0.7-2.1Mya, 2.0-5.9 spp./My) and (ii) the predominantly perennial species from the Andes Mountains of South America and highlands of Mexico (0.8-3.4Mya, 1.4-5.7spp./My). Bayesian posterior predictive tests for association between life history and maximum elevation demonstrate that perennials are positively correlated with higher elevations. These results are consistent with a series of one or more recent radiations in the western New World, and indicate that rapid diversification of Lupinus coincides with the derived evolution of perennial life history, colonization of montane habitats, and range expansion from North America to South America. PMID:18534869

Drummond, Christopher S

2008-08-01

153

Adjacent Habitat Influence on Stink Bug (Hemiptera: Pentatomidae) Densities and the Associated Damage at Field Corn and Soybean Edges  

PubMed Central

The local dispersal of polyphagous, mobile insects within agricultural systems impacts pest management. In the mid-Atlantic region of the United States, stink bugs, especially the invasive Halyomorpha halys (Stål 1855), contribute to economic losses across a range of cropping systems. Here, we characterized the density of stink bugs along the field edges of field corn and soybean at different study sites. Specifically, we examined the influence of adjacent managed and natural habitats on the density of stink bugs in corn and soybean fields at different distances along transects from the field edge. We also quantified damage to corn grain, and to soybean pods and seeds, and measured yield in relation to the observed stink bug densities at different distances from field edge. Highest density of stink bugs was limited to the edge of both corn and soybean fields. Fields adjacent to wooded, crop and building habitats harbored higher densities of stink bugs than those adjacent to open habitats. Damage to corn kernels and to soybean pods and seeds increased with stink bug density in plots and was highest at the field edges. Stink bug density was also negatively associated with yield per plant in soybean. The spatial pattern of stink bugs in both corn and soybeans, with significant edge effects, suggests the use of pest management strategies for crop placement in the landscape, as well as spatially targeted pest suppression within fields. PMID:25295593

Venugopal, P. Dilip; Coffey, Peter L.; Dively, Galen P.; Lamp, William O.

2014-01-01

154

Depth and Medium-Scale Spatial Processes Influence Fish Assemblage Structure of Unconsolidated Habitats in a Subtropical Marine Park  

PubMed Central

Where biological datasets are spatially limited, abiotic surrogates have been advocated to inform objective planning for Marine Protected Areas. However, this approach assumes close correlation between abiotic and biotic patterns. The Solitary Islands Marine Park, northern NSW, Australia, currently uses a habitat classification system (HCS) to assist with planning, but this is based only on data for reefs. We used Baited Remote Underwater Videos (BRUVs) to survey fish assemblages of unconsolidated substrata at different depths, distances from shore, and across an along-shore spatial scale of 10 s of km (2 transects) to examine how well the HCS works for this dominant habitat. We used multivariate regression modelling to examine the importance of these, and other environmental factors (backscatter intensity, fine-scale bathymetric variation and rugosity), in structuring fish assemblages. There were significant differences in fish assemblages across depths, distance from shore, and over the medium spatial scale of the study: together, these factors generated the optimum model in multivariate regression. However, marginal tests suggested that backscatter intensity, which itself is a surrogate for sediment type and hardness, might also influence fish assemblages and needs further investigation. Species richness was significantly different across all factors: however, total MaxN only differed significantly between locations. This study demonstrates that the pre-existing abiotic HCS only partially represents the range of fish assemblages of unconsolidated habitats in the region. PMID:24824998

Schultz, Arthur L.; Malcolm, Hamish A.; Bucher, Daniel J.; Linklater, Michelle; Smith, Stephen D. A.

2014-01-01

155

On territorial behavior and other factors influencing habitat distribution in birds  

Microsoft Academic Search

Summary This example is provided so that non-theorists may see actual applications of the theory previously described. This study considered directly some of the components of Field Sparrow breeding success as a measure of habitat suitability, and found these to vary in a way which was inconsistent with hypotheses that territorial behavior either cues, or limits density. This study provides

Stephen Dewitt Fretwell

1969-01-01

156

Prioritizing winter habitat quality for greater sage-grouse in a landscape influenced by energy development  

E-print Network

persistence. Key words: Centrocercus urophasianus; Colorado; energy disturbance; greater sage-grouse; linking models as a framework to quantify habitat value for wintering female greater sage-grouse (Centrocercus urophasianus) inhabiting a 6,093-km2 study area in northwest Colorado and south-central Wyoming, USA, being

Beck, Jeffrey L.

157

Influence of Riparian Habitat and Nutrients on Aquatic Communities Within Riparian Zones of Headwater Streams  

Technology Transfer Automated Retrieval System (TEKTRAN)

Headwater streams are the smallest streams in a watershed. Their small size and high frequency of occurrence make them susceptible to anthropogenic habitat alterations. Many headwater streams in the Midwestern United States have been channelized to drain agricultural fields. Aquatic macroinvertebrat...

158

Geographic, Anthropogenic and Habitat Influences on Great Lakes Coastal Wetland Fish Assemblages  

EPA Science Inventory

We analyzed data from coastal wetlands across all five Laurentian Great Lakes to identify patterns in fish assemblages and relationships to local habitat, watershed condition, and regional setting. NMDS ordination of electrofishing catch-per-effort data revealed an overriding ge...

159

INFLUENCE OF MOWING ARTEMISIA TRIDENTATA SSP. WYOMINGENSIS ON WINTER HABITAT FOR WILDLIFE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production for livestock, and create fuel breaks for fire suppression. However, information detailing the in...

160

Habitat and Grazing Influence on Terrestrial Ants in Subtropical Grasslands and Savannas of Argentina  

Technology Transfer Automated Retrieval System (TEKTRAN)

The maintenance of species diversity in modified and natural habitats is a central focus of conservation biology. The Iberá Nature Reserve (INR) protects highly diverse ecosystems in northeastern Argentina, including one of the largest freshwater wetlands in South America. Livestock grazing is one o...

161

ORIGINAL PAPER Winter habitat use does not influence spring arrival dates  

E-print Network

the breeding phenology and produc- tivity of Yellow Warblers (Setophaga petechia) at the extreme north Setophaga petechia Introduction Studies have shown that the quality of winter habitat occupied by migrant) and American Redstart (Setophaga ruti- cilla; 44°N) populations reported in previous studies. In the arctic, we

162

Environmental and human influences on trumpeter swan habitat occupancy in Alaska  

USGS Publications Warehouse

Approximately 70-80% of the entire population of the Trumpeter Swan (Cygnus huccinator) depends for reproduction on wetlands in Alaska. This makes the identification of important habitat features and the effects of human interactions important for the species' long-term management. We analyzed the swan's habitat preferences in five areas throughout the state and found that swan broods occupied some wetland types, especially larger closed-basin wetlands such as lakes and ponds, at rates much higher than they occupied other wetland types, such as shrubby or forested wetlands. We also found a negative effect of transportation infrastructure on occupancy by broods in and around the Minto Flats State Game Refuge, Kenai National Wildlife Refuge, and Tetlin National Wildlife Refuge. This finding is of particular interest because much of the Minto Flats refuge has recently been licensed for oil and gas exploration and parts of the Kenai refuge have been developed in the past. We also investigated the potential effects of the shrinkage of closed-basin ponds on habitat occupancy by nesting Trumpeter Swans. We compared nesting swans' use of ponds with changes in the ponds' size and other characteristics from 1982 to 1996 and found no relationships between occupancy and changes in pond size. However, we believe that the recent and rapid growth of Trumpeter Swan populations in Alaska may become limited by available breeding habitat, and anthropogenic and climate-induced changes to the swan's breeding habitats have the potential to limit future production. ?? 2009 by The Cooper Ornithological Society. All rights reserved.

Schmidt, J.H.; Lindberg, M.S.; Johnson, D.S.; Schmultz, J.A.

2009-01-01

163

Less is more: density influences the development of behavioural life skills in trout  

PubMed Central

Theory suggests that habitat structure and population density profoundly influence the phenotypic development of animals. Here, we predicted that reduced rearing density and increased structural complexity promote food search ability, anti-predator response and the ability to forage on novel prey, all behavioural skills important for surviving in the wild. Brown trout were reared at three densities (conventional hatchery density, a fourth of conventional hatchery density and natural density) in tanks with or without structure. Treatment effects on behaviour were studied on trout fry and parr, whereupon 20 trout from each of the six treatment groups were released in an enclosed natural stream and recaptured after 36 days. Fry reared at natural density were faster to find prey in a maze. Moreover, parr reared at natural density were faster to eat novel prey, and showed more efficient anti-predator behaviour than fish reared at higher densities. Furthermore, parr reared at reduced densities were twice as likely to survive in the stream as trout reared at high density. In contrast, we found no clear treatment effects of structure. These novel results suggest that reduced rearing densities can facilitate the development of behavioural life skills in captive animals, thereby increasing their contribution to natural production. PMID:20462903

Brockmark, S.; Adriaenssens, B.; Johnsson, J. I.

2010-01-01

164

Abundance, Behavior, and Habitat Utilization by Coho Salmon and Steelhead Trout in Fish Creek, Oregon, as Influenced by Habitat Enhancement: Annual Report 1985.  

SciTech Connect

Construction and evaluation of salmonid habitat improvements on Fish Creek, a tributary of the upper Clackamas River, is designed to increase the annual number of chinook and coho salmon, and steelhead trout smolt outmigrants. The primary objectives of the evaluation include the: (1) evaluation and quantification of changes in salmonid spawning and rearing habitat resulting from a variety of habitat improvements; (2) evaluation and quantification of changes in fish populations and biomass resulting from habitat improvements; and (3) evaluation of the cost-effectiveness of habitat improvements developed with BPA and Forest Service funds on Fish Creek. This report focuses on the projects completed in the basin in 1983, 1984, and 1985, and their evaluation.

Everest, Fred H.

1986-09-01

165

Forestry herbicide influences on biodiversity and wildlife habitat in Southern forests.  

SciTech Connect

Abstract In the southern United States, herbicide use continues to increase for timber management in commercial pine (Pinus spp.) plantations, for modifying wildlife habitats, and for invasive plant control. Several studies have reported that single applications of forestry herbicides at stand initiation have minor and temporary impacts on plant communities and wildlife habitat conditions, with some reports of enhanced habitat conditions for both game and nongame species. Due to the high resiliency of floral communities, plant species richness and diversity rebound rapidly after single herbicide treatments, with short- and long-term compositional shifts according to the selectivity and efficacy of the herbicide used. Recently, however, a shift to the Southeast in North American timber supplies has resulted in increased forest management intensity. Current site-preparation techniques rely on herbicide combinations, often coupled with mechanical treatments and >1 years of post-planting applications to enhance the spectrum and duration of vegetation control. This near-total control of associated vegetation at establishment and more rapid pine canopy closure, coupled with shortened and repeated rotations, likely will affect plant diversity and wildlife habitat quality. Development of mitigation methods at the stand and landscape levels will be required to minimize vegetative and wildlife impacts while allowing continued improvement in pine productivity. More uncertain are long-term impacts of increasing invasive plant occupation and the projected increase in herbicide use that will be needed to reverse this worsening situation. In addition, the potential of herbicides to meet wildlife management objectives in areas where traditional techniques have high social costs (e.g., prescribed fire) should be fully explored.

Miller, Karl V.; Miller, James, H.

2004-07-01

166

Forestry herbicide influences on biodiversity and wildlife habitats in Southern forests.  

SciTech Connect

Abstract In the southern United States, herbicide use continues to increase for timber management in commercial pine (Pinus spp.) plantations, for modifying wildlife habitats, and for invasive plant control. Several studies have reported that single applications of forestry herbicides at stand initiation have minor and temporary impacts on plant communities and wildlife habitat conditions, with some reports of enhanced habitat conditions for both game and nongame species. Due to the high resiliency of floral communities, plant species richness and diversity rebound rapidly after single herbicide treatments, with short- and long-term compositional shifts according to the selectivity and efficacy of the herbicide used. Recently, however, a shift to the Southeast in North American timber supplies has resulted in increased forest management intensity. Current site-preparation techniques rely on herbicide combinations, often coupled with mechanical treatments and >1 years of post-planting applications to enhance the spectrum and duration of vegetation control. This near-total control of associated vegetation at establishment and more rapid pine canopy closure, coupled with shortened and repeated rotations, likely will affect plant diversity and wildlife habitat quality. Development of mitigation methods at the stand and landscape levels will be required to minimize vegetative and wildlife impacts while allowing continued improvement in pine productivity. More uncertain are long-term impacts of increasing invasive plant occupation and the projected increase in herbicide use that will be needed to reverse this worsening situation. In addition, the potential of herbicides to meet wildlife management objectives in areas where traditional techniques have high social costs (e.g., prescribed fire) should be fully explored.

Miller, Karl V.

2004-01-01

167

Habitat differences influence genetic impacts of human land use on the American beech (Fagus grandifolia).  

PubMed

Natural reforestation after regional forest clearance is a globally common land-use sequence. The genetic recovery of tree populations in these recolonized forests may depend on the biogeographic setting of the landscape, for instance whether they are in the core or in the marginal part of the species' range. Using data from 501 individuals genotyped across 7 microsatellites, we investigated whether regional differences in habitat quality affected the recovery of genetic variation in a wind-pollinated tree species, American beech (Fagus grandifolia) in Massachusetts. We compared populations in forests that were recolonized following agricultural abandonment to those in remnant forests that have only been logged in both central inland and marginal coastal regions. Across all populations in our entire study region, recolonized forests showed limited reduction of genetic diversity as only observed heterozygosity was significantly reduced in these forests (H(O) = 0.520 and 0.590, respectively). Within inland region, this pattern was observed, whereas in the coast, recolonized populations exhibited no reduction in all genetic diversity estimates. However, genetic differentiation among recolonized populations in marginal coastal habitat increased (F(st) logged = 0.072; F(st) secondary = 0.249), with populations showing strong genetic structure, in contrast to inland region. These results indicate that the magnitude of recovery of genetic variation in recolonized populations can vary at different habitats. PMID:25138571

Lumibao, Candice Y; McLachlan, Jason S

2014-01-01

168

Abundance, Behavior, and Habitat Utilization by Coho Salmon and Steelhead Trout in Fish Creek, Oregon, as Influenced by Habitat Enhancement, 1985 Annual Report.  

SciTech Connect

Construction and evaluation of salmonid habitat improvements on Fish Creek, a tributary of the upper Clackamas River, was continued in fiscal year 1985 by the Estacada Ranger District, Mt. Hood National Forest, and the Anadromous Fish Habitat Research Unit of the Pacific Northwest Forest and Range Experiment Station (PNW), USDA Forest Service. The study began in 1982 when PNW entered into an agreement with the Mt. Hood National Forest to evaluate fish habitat improvements in the Fish Creek basin on the Estacada Ranger District. The project was initially conceived as a 5-year effort (19824986) to be financed by Forest Service funds. Several factors limiting production of salmonids in the basin were identified during the first year of the study, and the scope of the habitat improvement effort was subsequently enlarged. The habitat improvement program and the evaluation of improvements were both expanded in mid-1983 when the Bonneville Power Administration entered into an agreement with the Mt. Hood National Forest to provide additional funding for work on Fish Creek. Habitat improvement work in the basin is designed to increase the annual number of chinook and coho salmon, and steelhead trout smolt outmigrants. The primary objectives of the evaluation include the: (1) Evaluation and quantification of changes in salmonid spawning and rearing habitat resulting from a variety of habitat Improvements. (2) Evaluation and quantification of changes in fish populations and biomass resulting from habitat improvements. (3) Evaluation of the cost-effectiveness of habitat improvements developed with BPA and Forest Service funds on Fish Creek. Several prototype enhancement projects were constructed and tested during the first three years of the study. The Intention was to identify successful techniques that could then be broadly applied within the bash. This stepwise procedure has been largely successful in identifying the most promising enhancement techniques for the Fish Creek basin. To date, 7-10 percent of the habitat area in the basin has been treated. When work on Fish Creek is completed, it is estimated that 50-60 percent of the total habitat area used by anadromous salmonids will have received some form of treatment. This annual progress report will focus on the projects completed in the basin In 1983, 1984, and 1985, and their evaluation. Winter habitat use and coho salmon and steelhead trout smolt production will also be emphasized.

Wolfe, John (Mount Hood National Forest, Clackamas River Ranger District, Estacada, OR); Everest, Fred H. (Oregon State University, Pacific Northwest Forest and Range Experiment Station, Corvallis, OR); Heller, David A. (Mount Hood National Forest, Gresham, OR)

1986-09-01

169

High-resolution assessment of land use impacts on biodiversity in life cycle assessment using species habitat suitability models.  

PubMed

Agricultural land use is a main driver of global biodiversity loss. The assessment of land use impacts in decision-support tools such as life cycle assessment (LCA) requires spatially explicit models, but existing approaches are either not spatially differentiated or modeled at very coarse scales (e.g., biomes or ecoregions). In this paper, we develop a high-resolution (900 m) assessment method for land use impacts on biodiversity based on habitat suitability models (HSM) of mammal species. This method considers potential land use effects on individual species, and impacts are weighted by the species' conservation status and global rarity. We illustrate the method using a case study of crop production in East Africa, but the underlying HSMs developed by the Global Mammals Assessment are available globally. We calculate impacts of three major export crops and compare the results to two previously developed methods (focusing on local and regional impacts, respectively) to assess the relevance of the methodological innovations proposed in this paper. The results highlight hotspots of product-related biodiversity impacts that help characterize the links among agricultural production, consumption, and biodiversity loss. PMID:25584628

de Baan, Laura; Curran, Michael; Rondinini, Carlo; Visconti, Piero; Hellweg, Stefanie; Koellner, Thomas

2015-02-17

170

Hybridisation between two cyprinid fishes in a novel habitat: genetics, morphology and life-history traits  

PubMed Central

Background The potential role hybridisation in adaptive radiation and the evolution of new lineages has received much recent attention. Hybridisation between roach (Rutilus rutilus L.) and bream (Abramis brama L.) is well documented throughout Europe, however hybrids in Ireland occur at an unprecedented frequency, often exceeding that of both parental species. Utilising an integrated approach, which incorporates geometric morphometrics, life history and molecular genetic analyses we identify the levels and processes of hybridisation present, while also determining the direction of hybridisation, through the analysis of mitochondrial DNA. Results The presence of F2 hybrids was found to be unlikely from the studied populations, although significant levels of backcrossing, involving both parental taxa was observed in some lakes. Hybridisation represents a viable conduit for introgression of genes between roach and bream. The vast majority of hybrids in all populations studied exhibited bream mitochondrial DNA, indicating that bream are maternal in the majority of crosses. Conclusions The success of roach × bream hybrids in Ireland is not due to a successful self reproducing lineage. The potential causes of widespread hybridisation between both species, along with the considerations regarding the role of hybridisation in evolution and conservation, are also discussed. PMID:20529364

2010-01-01

171

Soil Fertility, Salinity and Nematode Diversity Influenced by Tamarix ramosissima in Different Habitats in an Arid Desert Oasis  

NASA Astrophysics Data System (ADS)

The aim of this paper was to assess the influence of tamarisk shrubs on soil fertility, salinity and nematode communities in various habitats located in an arid desert-oasis region in northwest China. Three habitats were studied: sand dune, riparian zone and saline meadow, where tamarisk shrubs have been established in recent decades in order to vegetation restoration used as desertification control and saline land rehabilitation projects and become the dominant plant community. The parameters measured include soil organic carbon (SOC), total nitrogen, available phosphorus (P) and potassium (K), pH, salt component, and nematode community characteristics. Enrichment ratios (a comparison of the soil measurements between soils under canopy and in the open interspaces) for soil nutrients and salinity were used to evaluate fertility and salinity islands underneath the tamarisk shrubs. The soil nematode community was used as a biological indicator of soil condition. SOC and available P and K were higher beneath the plant canopy than in the open interspaces outside that canopy. The enrichment ratios for SOC and nutrients were highest for the sand dune habitat and tamarisk shrubs clearly created islands of greater salinity under the canopies. Nematode abundance per 100 g dry soil varied considerably between the locations and habitats, with the highest abundance found in sand dune and the lowest in saline meadow. A significantly higher nematode abundance and a lower trophic diversity were found in soils under the canopy compared to the soils in the open interspaces. With the exception of saline meadow, the abundance of bacterivores increased and fungivores decreased under the canopy relative to the open interspaces, and bacterivores dominated under the canopies in the sand dune and riparian habitats. The enrichment ratios for salinity were higher than for fertility, suggesting that improved soil fertility can not limit the impact of salinization beneath tamarisk shrubs. The adverse effect of salt accumulation on the soil environment should be taken into account when using tamarisk as restoration plant species, especially in saline meadow and controlling of tamarisk density should be considered when undertaking re-vegetation projects in the arid desert oasis regions.

Yong-zhong, Su; Xue-fen, Wang; Rong, Yang; Xiao, Yang; Wen-jie, Liu

2012-08-01

172

Soil fertility, salinity and nematode diversity influenced by Tamarix ramosissima in different habitats in an arid desert oasis.  

PubMed

The aim of this paper was to assess the influence of tamarisk shrubs on soil fertility, salinity and nematode communities in various habitats located in an arid desert-oasis region in northwest China. Three habitats were studied: sand dune, riparian zone and saline meadow, where tamarisk shrubs have been established in recent decades in order to vegetation restoration used as desertification control and saline land rehabilitation projects and become the dominant plant community. The parameters measured include soil organic carbon (SOC), total nitrogen, available phosphorus (P) and potassium (K), pH, salt component, and nematode community characteristics. Enrichment ratios (a comparison of the soil measurements between soils under canopy and in the open interspaces) for soil nutrients and salinity were used to evaluate fertility and salinity islands underneath the tamarisk shrubs. The soil nematode community was used as a biological indicator of soil condition. SOC and available P and K were higher beneath the plant canopy than in the open interspaces outside that canopy. The enrichment ratios for SOC and nutrients were highest for the sand dune habitat and tamarisk shrubs clearly created islands of greater salinity under the canopies. Nematode abundance per 100 g dry soil varied considerably between the locations and habitats, with the highest abundance found in sand dune and the lowest in saline meadow. A significantly higher nematode abundance and a lower trophic diversity were found in soils under the canopy compared to the soils in the open interspaces. With the exception of saline meadow, the abundance of bacterivores increased and fungivores decreased under the canopy relative to the open interspaces, and bacterivores dominated under the canopies in the sand dune and riparian habitats. The enrichment ratios for salinity were higher than for fertility, suggesting that improved soil fertility can not limit the impact of salinization beneath tamarisk shrubs. The adverse effect of salt accumulation on the soil environment should be taken into account when using tamarisk as restoration plant species, especially in saline meadow and controlling of tamarisk density should be considered when undertaking re-vegetation projects in the arid desert oasis regions. PMID:22610148

Yong-zhong, Su; Xue-fen, Wang; Rong, Yang; Xiao, Yang; Wen-jie, Liu

2012-08-01

173

An ecological classification of Central European macromoths: habitat associations and conservation status returned from life history attributes  

Microsoft Academic Search

To be used as a predictive conservation tool, classification of animal habitats should rely on actual resource requirements\\u000a of individual species. Shreeve et al. (J Insect Conserv 5:145–161, 2001) produced a resource-based habitat classification for British butterflies, obtaining habitat association groups, whose constituent\\u000a species differed in their distribution extent, distribution change and vulnerability in Britain. To test the utility of

Anezka Pavlikova; Martin Konvicka

174

Influence of 4-H Horse Project Involvement on Development of Life Skills  

ERIC Educational Resources Information Center

Four-H horse project members who competed in non-riding horse contests were surveyed to evaluate the influence of their horse project participation on life-skill development. Contests in which youth competed included Horse Bowl, Demonstrations, Public Speaking, and Art. Youth indicated a positive influence on both life-skill development and horse…

Anderson, K. P.; Karr-Lilienthal, L.

2011-01-01

175

Genetic and Environmental Influences on Negative Life Events from Late Childhood to Adolescence  

ERIC Educational Resources Information Center

This multiwave longitudinal study tested two quantitative genetic developmental models to examine genetic and environmental influences on exposure to negative dependent and independent life events. Participants (N = 457 twin pairs) completed measures of life events annually from ages 9 to 16. The same genetic factors influenced exposure to…

Johnson, Daniel P.; Rhee, Soo Hyun; Whisman, Mark A.; Corley, Robin P.; Hewitt, John K.

2013-01-01

176

Landscape-scale Habitat Templates and Life Histories of Endangered and Invasive Fish Species in Large Rivers of the Mid-Continent USA (Invited)  

NASA Astrophysics Data System (ADS)

Many fish species migrate through river systems to complete their life cycles, occupying specific habitats during specific life stages. Regional geomorphology sets a template for their habitat-use patterns and ontogenetic development. In large rivers of the Mid-continent USA, understanding of relations of fish life histories to landscape-scale habitat templates informs recovery of endangered species and prevention of spread of invasive species. The endangered pallid sturgeon has evolved in the Missouri-Mississippi river system over 150 Ma. Its present-day distribution probably results from extensive drainage re-arrangements during the Pleistocene, followed by contemporary fragmentation. The reproductive and early life-stage needs of pallid sturgeon encompass hundreds of km, as adults migrate upstream to spawn and free embryos and larvae disperse downstream. Spawning requires coarse, hard substrate for incubation of adhesive eggs but adult pallid sturgeon are found predominately over sand, indicating that coarse substrate is a critical but transient habitat need. Once hatched, free-embryos initiate 9-17 days of downstream dispersal that distributes them over several hundreds of km. Lotic conditions at the dispersal terminus are required for survival. Persistent recruitment failure has been attributed to dams and channelization, which have fragmented migration and dispersal corridors, altered flow regimes, and diminished rearing habitats. Key elements of the natural history of this species remain poorly understood because adults are rare and difficult to observe, while the earliest life stages are nearly undetectable. Recent understanding has been accelerated using telemetry and hydroacoustics, but such assessments occur in altered systems and may not be indicative of natural behaviors. Restoration activities attempt - within considerable uncertainty -- to restore elements of the habitat template where they are needed. In comparison, invasive Asian carps have been present in large rivers of the Mid-Continent for no more than 40 years and have experienced rapid population growth as they exploit the landscape. Asian carps also spawn in turbulent water over coarse substrate, but in contrast to sturgeon, their eggs are buoyant and drift downstream, hatching in the water column, followed by continued dispersal as free-embryos and larvae. Asian carp eggs and larvae may drift for 4 to 7 days, with dispersal of several hundreds of km, depending on prevailing water velocities. After the drift phase, young Asian carp need lentic habitats in channel margins, floodplains, or lakes, to feed and grow. Hence, Asian carps need a habitat template that combines upstream flowing water and downstream floodplain connectivity. Control strategies for Asian carp seek to minimize access to required template elements. Managing habitat templates for endangered and invasive species on the same landscape may be complementary or conflicting. Understanding of the species' ecology and the landscape-scale habitat template is necessary for effective management.

Jacobson, R. B.; Braaten, P. J.; Chapman, D.; DeLonay, A. J.

2013-12-01

177

The influence of cardiovascular disease on quality of life in type 2 diabetics  

Microsoft Academic Search

Background and Aims: In type 2 diabetes mellitus, disease-related complications have a considerable effect on the quality of life. We studied the influence of cardiovascular disease on quality of life in type 2 diabetic patients in a longitudinal design. We also studied whether quality of life in any way predicts the manifes- tation of cardiovascular disease. Materials and methods: A

C. L. de Visser; H. J. G. Bilo; K. H. Groenier; W. de Visser; B. Meyboom-de Jong

2002-01-01

178

The influence of cardiovascular disease on quality of life in type 2 diabetics  

Microsoft Academic Search

Background and Aims: In type 2 diabetes mellitus, disease-related complications have a considerable effect on the quality of life. We studied the influence of cardiovascular disease on quality of life in type 2 diabetic patients in a longitudinal design. We also studied whether quality of life in any way predicts the manifestation of cardiovascular disease. Materials and methods: A prospective

C. L. de Visser; H. J. G. Bilo; K. H. Groenier; W. de Visser; B. Meyboom-de Jong

2002-01-01

179

Space Wear Vision -Development of a Wardrobe for Life in Space Vehicles and Habitats  

NASA Technical Reports Server (NTRS)

A new vision is needed for the development of a wardrobe for NASA's journey to Mars in the 2030s. All human space missions require significant logistical mass and volume that add an unprecedented burden on long-duration missions beyond low-Earth orbit. The logistical burden is at least twice as great for prolonged exploration and settlements on planetary surfaces compared to missions in low-Earth orbit. The space wear vision is to design apparel that uniquely meets criteria and constraints for sustaining human presence in space. For long duration missions without landing on planetary surface, humans can use only what they carry in their spacecraft, while for settlements, additional resources may be available. The immediate space wear goal is to develop those elements needed for prolonged manned exploration beyond low Earth orbit. Three major objectives have been identified for achieving this goal: satisfying crew preferences, logistics reduction and repurposing, and systems integration. Garments must be comfortable, durable, safe to wear, and aesthetically pleasing. In addition, with limited cleaning resources, garments must be developed to reduce the logistical burden by reducing clothing mass and extending clothing wear. Furthermore, garments must have minimal impact on the life support systems of spacecraft. The approach to achieving the immediate space wear goal is to conduct multiple studies on Earth and on the International Space Station (ISS), thus laying out the path for finding materials and designing garments that meet the three objectives of prolonged manned exploration. Several studies have been undertaken recently for the first time, namely, to ascertain garment length of wear and to assess the acceptance of such extended wear. Most garments in these studies have been exercise T-shirts and shorts, and routine-wear T-shirts. Eleven studies have been completed: five studies of exercise T-shirts, three of exercise shorts, two of routine wear T-shirts, and one of shirts used as sleep-wear. The IVA (Intra Vehicular Activity) Clothing Study has been the first study with Roscosmos under the "Utilization Sharing Plan On-Board ISS," while the other studies have been conducted at the Johnson Space Center in a controlled environment similar to the ISS. For exercise clothing, study participants wore garments during aerobic exercise. For routine wear clothing, study participants wore the T-shirts daily in an office or laboratory. Daily questionnaires collected data on ordinal preferences of nine sensory elements and on reasons for retiring a used garment. More studies have been initiated on Earth, and some should be planned to engage more astronauts and cosmonauts in the design of the new space wear. Future studies will extend to other types of garments in the wardrobe; another will address microbial growth on textiles. Others will address cleaning and sanitation of clothing in space vehicles. Efforts will be made for additional ISS studies with NASA's international partners.

Orndorff, Evelyne

2015-01-01

180

Influence of Life Style Factors on Barrett's Oesophagus.  

PubMed

Background. Since the incidence of adenocarcinoma of the oesophagus is rising, the prognosis is poor, and surveillance programs are expensive and mostly cost ineffective, there is a need to increase the knowledge of risk factors in Barrett's oesophagus and oesophageal cancer in order to be able to give attention to medical prevention and/or surveillance programs. Aim. To study if there is a correlation between the development of Barrett's oesophagus and GOR (gastro oesophageal reflux), family history of GOR, and life style factors, such as alcohol, smoking habits, and mental stress. Methods. Fifty-five consecutively selected patients with Barrett's oesophagus (BO) examined at Linköping University Hospital's Oesophageal Laboratory were matched by sex, age, and duration of reflux symptoms with 55 GOR patients without Barrett's oesophagus at the Oesophageal Laboratory. The medical charts in respective groups were examined for comparison of life style factors, mental stress, medication, duration of gastroesophageal acid reflux at 24?hr-pH-metry, and incidence of antireflux surgery and of adenocarcinoma of the oesophagus (ACO). Also, potential gender differences and diagnosis of ACO were studied. Results. Mean percentage reflux time on 24?hr-pH-metry was higher for the Barrett's oesophagus group, 18% for women and 17% for men compared to 4% for women and 4% for men in the control group (P < 0.05). Family history of GOR was more frequent in Barrett's oesophagus patients (62%) than in the control group (35%) (P < 0.05). Male patients with Barrett's oesophagus had medical therapy for their GOR symptoms to a higher extent (38%) than male controls (65%) (P < 0.05). No difference was found in the number of tobacco users or former tobacco users between Barrett's oesophagus patients and controls. Barrett's oesophagus patients had the same level of alcohol consumption and the same average BMI as the control subjects. Female patients with Barrett's oesophagus rated themselves as more mentally stressed (67%) than the female controls (38%) (P < 0.05). In the five-year medical chart follow-up, five of 55 patients developed adenocarcinoma among the Barrett's oesophagus patients, none in the control group. Conclusions. Long reflux time and family clustering of GOR seem to influence the development of Barrett's oesophagus. Smoking habits, alcohol consumption and BMI do not seem to have any impact on the development of Barrett's oesophagus. PMID:24971090

Horna Strand, A; Franzén, T

2014-01-01

181

Modeling the influence of Peromyscus leucopus body mass, sex, and habitat on immature Dermacentor variabilis burden.  

PubMed

Immature (larvae and nymph) tick burden on rodents is an important determinant of adult tick population size and understanding infectious disease dynamics. The objective of this research was to build a descriptive model for immature Dermacentor variabilis burden on Peromyscus leucopus. Mice were live-trapped on two permanent grids in an old field and an early successional forest every other month between April and October, 2006-2009. Negative binomial regression was used to examine the association between immature D. variabilis burden and the host related variables of host habitat, body mass, and/or sex. The model containing all three variables had the lowest Akaike's Information Criterion (AIC), corrected AIC (AICc), and greatest AICc weight. Immature D. variabilis burden was positively associated with mice with higher body mass, male mice, and those captured in the field habitat. These data are consistent with studies from other tick-rodent systems and suggest that single factor models do not describe host burden. Variables other than those that are related to the host may also be important in describing the tick burden on rodents. The next step is to examine variables that affect tick development rate and questing behavior. PMID:23181857

Dallas, Tad A; Foré, Stephanie A; Kim, Hyun-Joo

2012-12-01

182

Whillans Ice Stream Subglacial Access Research Drilling (WISSARD): Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats (Invited)  

NASA Astrophysics Data System (ADS)

The WISSARD project is a large, NSF-funded, interdisciplinary initiative focused on scientific drilling, exploration, and investigation of Antarctic subglacial aquatic environments. The project consists of three interrelated components: (1) LISSARD - Lake and Ice Stream Subglacial Access Research Drilling, (2) RAGES - Robotic Access to Grounding-zones for Exploration and Science, and (3) GBASE - GeomicroBiology of Antarctic Subglacial Environments). A number of previous studies in West Antarctica highlighted the importance of understanding ice sheet interactions with water, either at the basal boundary where ice streams come in contact with active subglacial hydrologic and geological systems or at the marine margin where the ice sheet is exposed to forcing from the global ocean and sedimentation. Recent biological investigations of Antarctic subglacial environments show that they provide a significant habitat for life and source of bacterial carbon in a setting that was previously thought to be inhospitable. Subglacial microbial ecosystems also enhance biogeochemical weathering, mobilizing elements from long term geological storage. The overarching scientific objective of WISSARD is to examine the subglacial hydrological system of West Antarctica in glaciological, geological, microbiological, geochemical, and oceanographic contexts. Direct sampling will yield seminal information on these systems and test the overarching hypothesis that active hydrological systems connect various subglacial environments and exert major control on ice sheet dynamics, subglacial sediment transfer, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations and geological records of ice sheet history. Technological advances during WISSARD will provide the US-science community with a capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and it will be available for future use. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments.

Tulaczyk, S. M.; Anandakrishnan, S.; Behar, A. E.; Christner, B. C.; Fisher, A. T.; Fricker, H. A.; Holland, D. M.; Jacobel, R. W.; Mikucki, J.; Mitchell, A. C.; Powell, R. D.; Priscu, J. C.; Scherer, R. P.; Severinghaus, J. P.

2009-12-01

183

Habitat Suitability Index Models: Pronghorn  

USGS Publications Warehouse

This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the pronghorn (Antilocapra americana) are synthesized. These data are subsequently used to develop Habitat Suitability Index (HSI) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Allen, Arthur W.; Cook, John G.; Armbruster, Michael J.

1984-01-01

184

Paradata for 'Distribution, Habitat Use and Life History of Stream-dwelling Crayfish in the Spring River Drainage of Arkansas and Missouri with a Focus on the Imperiled Mammoth Spring Crayfish (Orconectes marchandi)'  

NSDL National Science Digital Library

This record contains paradata for the resource 'Distribution, Habitat Use and Life History of Stream-dwelling Crayfish in the Spring River Drainage of Arkansas and Missouri with a Focus on the Imperiled Mammoth Spring Crayfish (Orconectes marchandi)'

185

Leaf alkaloid contents of Tabernaemontana pachysiphon as influenced by endogenous and environmental factors in the natural habitat.  

PubMed

Indole alkaloid contents were investigated in leaves of Tabernaemontana pachysiphon (Apocynaceae) trees in the natural habitat, Shimba Hills National Reserve, Kenya. The contents of the major alkaloids apparicine, tubotaiwine, tubotaiwine- N-oxide, and isovoacangine varied with site, leaf age, leaf growth form, position in the crown, and plant age. Alkaloid contents were highest in young leaves. Trees bearing aberrant small dwarf-leaves showed similar alkaloid patterns as young leaves from healthy trees. At single trees, the contents were found to increase from the top to the bottom of the crown. Tree age had little influence on leaf alkaloid contents. In even aged leaves of trees from different forest sites, alkaloid contents were highest at the site with highest soil cation exchange capacity (CEC) and base saturation. PMID:17253230

Höft, M; Verpoorte, R; Beck, E

1998-03-01

186

Identifying when weather influences life-history traits of grazing herbivores  

Microsoft Academic Search

Summary 1. There is increasing evidence that density-independent weather effects influence life-history traits and hence the dynamics of populations of animals. Here, we present a novel statistical approach to estimate when such influences are strongest. The method is demonstrated by analyses investigating the timing of the influence of weather on the birth weight of sheep and deer. 2. The statistical

MICHELLE SIMS; DAVID A. ELSTON; ANN LARKHAM; DANIEL H. NUSSEY; STEVE D. ALBON

2007-01-01

187

Geographic and Habitat Origin Influence Biomass Production and Storage Translocation in the Clonal Plant Aegopodium podagraria  

PubMed Central

Through physiological integration, clonal plants can support ramets in unfavourable patches, exploit heterogeneously distributed resources and distribute resources that are taken up over large areas. Physiological integration generally increases in adverse conditions, but it is not well known which factors determine the evolution of physiological integration. The aim of this study was to investigate if clonal plants from Southern and Northern populations of the clonal herb Aegopodium podagraria differed in physiological integration in terms of translocation of carbon to the rhizomes, and in biomass production using a reciprocal transplant experiment. Aegopodium podagraria from shaded conditions have been suggested to share more resources than clones from open conditions and therefore, plants from forest and open populations within the Southern and Northern regions were included. The regional growing conditions greatly affected biomass production. Plants grown in North Sweden produced more biomass and allocated more biomass to shoots, while plants grown in South Sweden allocated more biomass to rhizomes. There was a regional origin effect as plants originating from North Sweden produced more biomass in both regions. Within the Northern region, plants from shaded habitats translocated more 14C to the rhizomes, suggesting more storage there than in plants from open habitats. In addition to genetic differentiation in biomass production between Northern and Southern populations, probably as a response to a shorter growing season in the North, there appeared to be genetic differentiation in physiological integration within the Northern region. This shows that both regional and local conditions need to be taken into account in future studies of genetic differentiation of physiological integration in clonal plants. PMID:24427305

D?Hertefeldt, Tina; Eneström, Johanna M.; Pettersson, Lars B.

2014-01-01

188

Volcaniclastic habitats for early life on Earth and Mars: A case study from ˜3.5 Ga-old rocks from the Pilbara, Australia  

NASA Astrophysics Data System (ADS)

Within the context of present and future in situ missions to Mars to investigate its habitability and to search for traces of life, we studied the habitability and traces of past life in ˜3.5 Ga-old volcanic sands deposited in littoral environments an analogue to Noachian environments on Mars. The environmental conditions on Noachian Mars (4.1-3.7 Ga) and the Early Archaean (4.0-3.3 Ga) Earth were, in many respects, similar: presence of liquid water, dense CO 2 atmosphere, availability of carbon and bio-essential elements, and availability of energy. For this reason, information contained in Early Archaean terrestrial rocks concerning habitable conditions (on a microbial scale) and traces of past life are of relevance in defining strategies to be used to identify past habitats and past life on Mars. One such example is the 3.446 Ga-old Kitty's Gap Chert in the Pilbara Craton, NW. Australia. This formation consists of volcanic sediments deposited in a coastal mudflat environment and is thus a relevant analogue for sediments deposited in shallow water environments on Noachian Mars. Two main types of habitat are represented, a volcanic (lithic) habitat and planar stabilized sediment surfaces in sunlit shallow waters. The sediments hosted small (<1 ?m in size) microorganisms that formed colonies on volcanic particle surfaces and in pore waters within the volcanic sediments, as well as biofilms on stabilised sediment surfaces. The microorganisms included coccoids, filaments and rare rod-shaped organisms associated with microbial polymer (EPS). The preserved microbial community was apparently dominated by chemotrophic organisms but some locally transported filaments and filamentous mat fragments indicate that possibly photosynthetic mats formed nearby. Both microorganisms and sediments were silicified during very early diagenesis. There are no macroscopic traces of fossilised life in these volcanic sediments and sophisticated instrumentation and specialized sample preparation techniques are required to establish the biogenicity and syngenicity of the traces of past life. The fact that the traces of life are cryptic, and the necessity of using sophisticated instrumentation, reinforces the challenges and difficulties of in situ robotic missions to identify past life on Mars. We therefore recommend the return of samples from Mars to Earth for a definitive search for traces of life.

Westall, Frances; Foucher, Frédéric; Cavalazzi, Barbara; de Vries, Sjoukje T.; Nijman, Wouter; Pearson, Victoria; Watson, Jon; Verchovsky, Alexander; Wright, Ian; Rouzaud, Jean-Noel; Marchesini, Daniele; Anne, Severine

2011-08-01

189

Habitat and phylogeny influence salinity discrimination in crocodilians: implications for osmoregulatory physiology and historical biogeography  

Microsoft Academic Search

Crocodylids are better adapted than alligatorids, through a suite of morphological specializations, for life in hyperosmotic environments. The presence of such specializations even in freshwater crocodylids has been interpreted as evidence for a marine phase in crocodylid evolution, consistent with the trans-osceanic migration hypothesis of crocodilian biogeography. The ability to discriminate fresh water from hyperosmotic sea water, and to avoid

KATE JACKSON; DAVID G. BUTLER; DANIEL R. BROOKS

1996-01-01

190

Influence of extrinsic variables on activity and habitat selection of lowland tapirs ( Tapirus terrestris) in the coastal sand plain shrub, southern Brazil  

Microsoft Academic Search

The objectives of this research were to: 1. evaluate the circadian activity patterns of lowland tapirs (Tapirus terrestris) throughout the seasons and 2. study the influence of moonlight, temperature and rainfall on the activity patterns and habitat selection of this species, in the coastal sand shrub in southern Brazil. From June 2005 to June 2006, eight tapirs were monitored in

Luiz Gustavo R. Oliveira-Santos; Luiz Carlos P. Machado-Filho; Marcos Adriano Tortato; Luisa Brusius

2010-01-01

191

The influence of disturbed habitat on the spatial ecology of Argentine black and white tegu (Tupinambis merianae), a recent invader in the Everglades ecosystem (Florida, USA)  

USGS Publications Warehouse

The threat of invasive species is often intensified in disturbed habitat. To optimize control programs, it is necessary to understand how degraded habitat influences the behavior of invasive species. We conducted a radio telemetry study to characterize movement and habitat use of introducedmale Argentine black and white tegus (Tupinambis merianae) in the Everglades of southern Florida from May to August 2012 at the core and periphery of the introduced range. Tegus at the periphery moved farther per day (mean 131.7 ± 11.6 m, n = 6) compared to tegus at the core (mean 50.3 ± 12.4 m, n = 6). However, activity ranges were not significantly smaller in the core (mean 19.4 ± 8.4 ha, n = 6) compared to periphery (mean 29.1 ± 5.2 ha, n = 6). Peripheral activity ranges were more linear due to activity being largely restricted to levee habitat surrounded by open water or marsh. Tegus were located in shrub or tree habitat (mean 96 %) more often than expected based on random locations (mean 58 %), and the percent cover of trees and shrubs was higher in activity ranges (mean 61 %) than the general study area (17 %). Our study highlighted the ability of tegus to spread across the Florida landscape, especially in linear disturbed habitats where increased movement occurred and in areas of altered hydrology where movement is not restricted by water.

Klug, Page E.; Reed, Robert N.; Mazzotti, Frank J.; McEachern, Michelle A.; Vinci, Joy J.; Craven, Katelin K.; Yackel Adams, Amy A.

2015-01-01

192

Does Autocthonous Primary Production Influence Oviposition by Aedes japonicus japonicus (Diptera: Culicidae) in Container Habitats?  

PubMed Central

Aedes (Finlaya) japonicus japonicus (Theobald) (Diptera: Culicidae) is recently invasive in North America and has expanded its range rapidly since 1998. Throughout its native and expanded range, Ae. j. japonicus larvae are commonly observed in many types of natural and artificial water-filled containers that vary in organic matter content and exposure to sunlight. Larvae are most often found in containers with decaying leaf material or algae, and we postulated that the added autocthonous primary production from algae could be both an important food source for larvae and an influential oviposition attractant to adult Ae. j. japonicus. We tested this hypothesis by placing plastic containers with varied levels of shading to manipulate algal density in the field, and then monitored oviposition by natural populations of Ae. j. japonicus. Over 99% of larvae hatching from eggs laid on the walls of our containers were Ae. j. japonicus, indicating that this species is a dominant colonizer of artificial containers in the study areas. Although full shading treatments effectively reduced algal biomass (significant reduction in chlorophyll a levels), at only one of three sites did this appear to affect Ae. j. japonicus oviposition. We conclude that algae in larval habitats are not a major factor in oviposition choices of adult Ae. j. japonicus females except when in situ primary production is high enough to substantially alter overall organic matter content cues. PMID:23427654

LORENZ, AMANDA R.; WALKER, EDWARD D.; KAUFMAN, MICHAEL G.

2014-01-01

193

Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover  

USGS Publications Warehouse

The Karner blue butterfly Lycaeides melissa samuelis is an endangered species residing in the Great Lakes and northeastern regions of the United States. Increased canopy cover is a major factor implicated in the decline of the Karner blue at many locales. Therefore, we examined how the butterfly's behavior varied with canopy cover. Adult males at Indiana Dunes National Lakeshore used habitat under canopy openings for nearly 90% of their activities; females used openings and shaded areas more equally. The frequency of oviposition on the sole host plant, wild lupine Lupinus perennis, was highest under 30-60% canopy cover even though lupine was more abundant in more open areas. Larvae fed preferentially on larger lupine plants and on lupines in denser patches. However, lupines were generally larger in the shade. Therefore, shade-related trade-offs existed between lupine abundance and distribution of larval feeding and oviposition. Also, heterogeneity of shading by sub-canopy woody vegetation was greater at oviposition sites than at sites where lupine did not grow. Given the importance of shade heterogeneity, a mixture of canopy openings and shade, on a scale similar to daily adult movement range, should be beneficial for this butterfly.

Grundel, R.; Pavlovic, N.B.; Sulzman, C.L.

1998-01-01

194

Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover  

USGS Publications Warehouse

The Karner blue butterfly Lycaeides melissa samuelis is an endangered species residing in the Great Lakes and northeastern regions of the United States. Increased canopy cover is a major factor implicated in the decline of the Karner blue at many locales. Therefore, we examined how the butterfly's behavior varied with canopy cover. Adult males at Indiana Dunes National Lakeshore used habitat under canopy openings for nearly 90% of their activities; females used openings and shaded areas more equally. The frequency of oviposition on the sole host plant, wild lupine Lupinus perennis, was highest under 30-60% canopy cover even though lupine was more abundant in more open areas. Larvae fed preferentially on larger lupine plants and on lupines in denser patches. However, lupines were generally large in the shade. Therefore, shade-related trade-offs existed between lupine abundance and distribution of larval feeding and oviposition. Also, heterogeneity of shading by sub-canopy woody vegetation was greater at oviposition sites than at sites where lupine did not grow. Given the importance of shade heterogeneity, a mixture of canopy opening and shades, on a scale similar to daily adult movement range, should be beneficial for this butterfly.

Grundel, Ralph; Pavlovic, Noel B.; Sulzman, Christina L.

1998-01-01

195

Environmental, behavioral, and habitat variables influencing body temperature in radio-tagged bullsnakes, Pituophis catenifer sayi  

Microsoft Academic Search

Studies regarding the thermal ecology of snakes are important to understanding their life histories. Yet, little is known about the thermal ecology of the North American genus Pituophis, which includes the bullsnake (Pituophis catenifer sayi). In an attempt to determine which independent variables significantly affected the thermal ecology of free-ranging bullsnakes, we tracked 12–19 radio-tagged individuals weekly from 2003 to

J. M. Kapfer; M. J. Pauers; D. M. Reineke; J. R. Coggins; R. Hay

2008-01-01

196

Removal of small dams and its influence on physical habitat for salmonids in a Norwegian river  

Microsoft Academic Search

While research and implementation of upstream migration solutions is extensive, and indeed often successful, full scale restoration projects and investigations of their influence on fish biology are rare in Norway. Acid deposition in Norwegian catchments peaked in the 1980's and resulted in both chronically and episodically acidified rivers and Salmonids in River Nidelva, one of the largest cathments in southern

Hans-Petter Fjeldstad; Bjørn Barlaup; Morten Stickler; Knut Alfredsen; Sven-Erik Gabrielsen

2010-01-01

197

Caenorhabditis elegans neuronal regeneration is influenced by life stage, ephrin signaling,  

E-print Network

regeneration in genetically tractable model organisms. AlCaenorhabditis elegans neuronal regeneration is influenced by life stage, ephrin signaling functional regeneration of Caenorhabditis elegans motor neurons after femtosecond laser axotomy. We report

Yanik, Mehmet Fatih

198

Habitat manipulation of Exposed Riverine Sediments (ERS) how does microhabitat, microclimate and food availability influence beetle distributions?  

NASA Astrophysics Data System (ADS)

Exposed riverine sediments (ERS) are frequently inundated areas of relatively un-vegetated, fluvially deposited sediment (sand, silt, gravel and pebble). These habitats provide an important interface allowing the interaction of aquatic and terrestrial habitats and species. ERS are highly valuable for many rare and specialist invertebrates particularly beetles. Within an area of ERS, beetle species richness tends to be highest along the water's edge. This higher species richness may be linked to: (1) the availability of food items in the form of emerging and stranded aquatic invertebrates and (2) favourable physical microhabitat conditions in terms of temperature and moisture. This paper explores the role of microclimate and food availability by creating areas of ‘water's edge' habitat in the centre of a gravel bar. Typically these areas are drier, reach higher temperatures and devoid of emerging aquatic invertebrate prey. Four 2m x 2m experimental plots were created: one wet plot, one wet- fed plot, one dry-fed plot and one dry plot (control). These plots were each replicated on three separate areas of ERS. Sixty colour marked ERS specialist ground beetles (Bembidion atrocaeruleum) were released into each plot to monitor beetle persistence and movement on and between plots. The plots were maintained wet using a capillary pump system, and fed with dried blood worms for 30 days. Sediment temperature (0.05 m depth) was measured at 15 minute intervals and spot measurements of surface temperature were taken daily. A hand search was carried out on 25% of each plot after 7, 14, 21 and 30 days. Significant temperature differences were observed between the wet and dry sediment and air temperature. The wet plots on average were 1.8oC cooler than the dry plots and had a reduced temperature range. Both wet and dry sediments remained significantly warmer than air temperature. The wet and wet-fed plots yielded significantly greater numbers of beetles and marked beetles than the dry and dry-fed plots; however, no significant difference was found between the wet and wet-fed plots. These results indicate that microhabitat in terms of increased moisture and lower temperature is the driving factor influencing beetle distribution and movement. Food alone is not as influential. ERS carabid beetles may be using lower temperatures and increased moisture as a cue for aquatic food availability.

Henshall, S. E.; Sadler, J. P.; Hannah, D. M.

2009-04-01

199

The influence of habitat, season and tidal regime in the activity of the intertidal crab Neohelice (= Chasmagnathus) granulata  

NASA Astrophysics Data System (ADS)

The activity pattern of intertidal crabs is influenced by factors that usually change rhythmically following tidal and/or diel cycles, and is often associated with the use of refuges. The movement activity of the burrowing crab Neohelice granulata was compared among three populations from SW Atlantic coastal areas where they face different tidal regimes, water salinities, substrata and biological factors. At each site, we examined the seasonal activity of the crabs (individuals collected in pitfall traps) in two types of habitat: mudflat and salt marsh. The working hypothesis is that the activity would vary according to the diverse environmental conditions encountered at geographical and local scales. Crab activity varied between sites and seasons showing to be more intense when habitats were covered by water. The most active groups were large males, followed by large non-ovigerous females. Ovigerous females were almost inactive. Most crabs were near or inside burrows at low tides in Mar Chiquita and Bahía Blanca, but they were active at both low and high tides in San Antonio during spring and summer. N. granulata were active in a wide range of temperatures: from 10 to 37 °C at low tides and at temperatures as low as 2 °C when covered by water. Differences of activity between mudflat and salt marsh varied among sites depending on flooding frequencies. Movement activity of N. granulata varied both in space and in time; crabs move under very different abiotic conditions (e.g., low or high tide, daylight or night, low and high temperature) and their movement may also be prevented or elicited by biotic conditions like burrow complexity, food quality and predation pressure. The wide set of conditions under which N. granulata can be active may explain why this is the only semiterrestrial crab inhabiting latitudes higher than 40°S in South America.

Luppi, Tomás; Bas, Claudia; Méndez Casariego, Agustina; Albano, Mariano; Lancia, Juan; Kittlein, Marcelo; Rosenthal, Alan; Farías, Nahuel; Spivak, Eduardo; Iribarne, Oscar

2013-03-01

200

Habitat-Mediated Facilitation and Counteracting Ecosystem Engineering Interactively Influence Ecosystem Responses to Disturbance  

PubMed Central

Recovery of an ecosystem following disturbance can be severely hampered or even shift altogether when a point disturbance exceeds a certain spatial threshold. Such scale-dependent dynamics may be caused by preemptive competition, but may also result from diminished self-facilitation due to weakened ecosystem engineering. Moreover, disturbance can facilitate colonization by engineering species that alter abiotic conditions in ways that exacerbate stress on the original species. Consequently, establishment of such counteracting engineers might reduce the spatial threshold for the disturbance, by effectively slowing recovery and increasing the risk for ecosystem shifts to alternative states. We tested these predictions in an intertidal mudflat characterized by a two-state mosaic of hummocks (humps exposed during low tide) dominated by the sediment-stabilizing seagrass Zostera noltii) and hollows (low-tide waterlogged depressions dominated by the bioturbating lugworm Arenicola marina). In contrast to expectations, seagrass recolonized both natural and experimental clearings via lateral expansion and seemed unaffected by both clearing size and lugworm addition. Near the end of the growth season, however, an additional disturbance (most likely waterfowl grazing and/or strong hydrodynamics) selectively impacted recolonizing seagrass in the largest (1 m2) clearings (regardless of lugworm addition), and in those medium (0.25 m2) clearings where lugworms had been added nearly five months earlier. Further analyses showed that the risk for the disturbance increased with hollow size, with a threshold of 0.24 m2. Hollows of that size were caused by seagrass removal alone in the largest clearings, and by a weaker seagrass removal effect exacerbated by lugworm bioturbation in the medium clearings. Consequently, a sufficiently large disturbance increased the vulnerability of recolonizing seagrass to additional disturbance by weakening seagrass engineering effects (sediment stabilization). Meanwhile, the counteracting ecosystem engineering (lugworm bioturbation) reduced that threshold size. Therefore, scale-dependent interactions between habitat-mediated facilitation, competition and disturbance seem to maintain the spatial two-state mosaic in this ecosystem. PMID:21829719

Eklöf, Johan S.; van der Heide, Tjisse; Donadi, Serena; van der Zee, Els M.; O'Hara, Robert; Eriksson, Britas Klemens

2011-01-01

201

Influence of home care on life satisfaction, loneliness, and perceived life stress.  

PubMed

ABSTRACT Strong evidence has established the medical and health services utilization benefits of home care services for older adults. However, sparse research has been conducted on potential psychosocial benefits. Older adults (65 and over) receiving home care with their needs met are compared with persons who have unmet needs (whether they received home care or not) on three key indicators of quality of life - life satisfaction, loneliness, and perceived life stress. Data are drawn from the 2008-2009 Canadian Community Health Survey respondents who met the study criteria (n = 3,244). Regression analyses showed that older adults who had their home care needs met reported higher levels of life satisfaction, and lower levels of loneliness and perceived life stress, than those with unmet needs, net of co-variates. The results suggest that filling this home care gap would significantly raise quality of life by increasing social and environmental resilience to age in place. PMID:25547720

Kadowaki, Laura; Wister, Andrew V; Chappell, Neena L

2015-03-01

202

Quantifying the influence of environmental texture on the rate of species turnover: evidence from two habitats  

Microsoft Academic Search

The environmental texture hypothesis (ETH) proposes that the spatial geometry or texture of the environment influences the\\u000a rate at which species are accumulated in space or time. Specifically, the ETH suggests that regions, and spatial scales, that\\u000a exhibit a larger rate of environmental distance decay (DD) should exhibit more rapid rates of species turnover. The ETH should\\u000a apply over any

D. J. McGlinn; M. W. Palmer

2011-01-01

203

Territorial behavior of the plethodontid salamander Plethodon kentucki : influence of habitat structure and population density  

Microsoft Academic Search

To investigate the possible influence of variation in ecological and demographic factors on the spatial organization of the\\u000a terrestrial plethodontid salamander Plethodon kentucki, I conducted a 3-year capture-recapture study and determined home-range characteristics and spatial relationships of individuals\\u000a at two field sites that differed in predominant cover type and population density. Home ranges of adults were fixed and the\\u000a home

Glenn A. Marvin

1998-01-01

204

Is Life-Style Related to Personality, Role Concept, and the Influence of Significant Others?  

ERIC Educational Resources Information Center

A study was conducted to examine the relationship between life-style, personality, role concept, and the influence of significant others in married women pursuing traditional, neotraditional, and nontraditional life-styles. Traditional women are defined as those who left paid employment after marriage or the birth of their first child;…

O'Connell, Agnes N.

205

Earth is a Marine Habitat. Habitat Conservation Program.  

ERIC Educational Resources Information Center

This brochure is intended to educate the public about the need to conserve and preserve the earth's environment (man's habitat). It contains an introduction to the ocean world and threats to coastal habitat. Photos and narrative revolve around the theme "Earth is a Marine Habitat." Sections include: "The Web of Life,""Oceans and the United…

National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

206

Can environmental conditions experienced in early life influence future generations?  

PubMed Central

The consequences of early developmental conditions for performance in later life are now subjected to convergent interest from many different biological sub-disciplines. However, striking data, largely from the biomedical literature, show that environmental effects experienced even before conception can be transmissible to subsequent generations. Here, we review the growing evidence from natural systems for these cross-generational effects of early life conditions, showing that they can be generated by diverse environmental stressors, affect offspring in many ways and can be transmitted directly or indirectly by both parental lines for several generations. In doing so, we emphasize why early life might be so sensitive to the transmission of environmentally induced effects across generations. We also summarize recent theoretical advancements within the field of developmental plasticity, and discuss how parents might assemble different ‘internal’ and ‘external’ cues, even from the earliest stages of life, to instruct their investment decisions in offspring. In doing so, we provide a preliminary framework within the context of adaptive plasticity for understanding inter-generational phenomena that arise from early life conditions. PMID:24807254

Burton, Tim; Metcalfe, Neil B.

2014-01-01

207

Factors influencing young adults’ attitudes and knowledge of late-life sexuality among older women  

Microsoft Academic Search

Objectives: Although sexuality is valued throughout the lifespan, older women's sexual expression can be influenced by physical, mental and social factors, including attitudes and stereotypes held by younger generations. By gaining an understanding of what influences negative attitudes toward sexuality and beliefs about sexual consent capacity, the stigma associated with sexuality in late life may be reduced.Method: Using vignette methodology

Rebecca S. Allen; Kathryn N. Petro; Laura L. Phillips

2009-01-01

208

Anthropogenic influences on heavy metals across marine habitats in the western coast of Venezuela  

NASA Astrophysics Data System (ADS)

Concentrations of ten metals were measured in waters and sediments at 14 sites during four sampling periods (1996-1997). These sites include various marine ecosystems that are highly influenced by industry, tourism and river discharges, nine of which are within the Morrocoy National Park. Spatially, metal concentrations in water were homogenous, whereas in sediments their distributions were related to grain size. Maximum concentrations of cadmium (Cd) and mean concentrations of copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in water were above the guideline values proposed by NOAA, indicating the potential of these metals for producing chronic effects in marine biota. Sheltered sites showed the highest metal concentrations in sediments; with Cd and Zn above these guidelines. Enrichment factors and geo-accumulation indexes suggested that metals in sediments were largely of natural origin except for Pb, Cd and vanadium (V), which were apparently associated with industrial effluents. A disruption of the spatial distribution of metals after heavy rainfall, when exposed sites reached concentrations as high as those in sheltered sites, showed the influence of nearby rivers. The potential increase of such climatic events could represent additional stress for natural protected areas in the Caribbean.

García, E. M.; Cruz-Motta, J. J.; Farina, O.; Bastidas, C.

2008-12-01

209

Art Influencing Art: The Making of "An Extraordinary Life."  

ERIC Educational Resources Information Center

Explores the creation of "An Extraordinary Life: The Story of a Monarch Butterfly." Selects this book because of the unprecedented decision to give the 1998 Orbis Pictus Award to both the author and the illustrator for a work in which text and illustration melded together. Develops an event model, revealing the creation of this illustrated…

Kerper, Richard M.

2002-01-01

210

Prestraining and Its Influence on Subsequent Fatigue Life  

NASA Technical Reports Server (NTRS)

An experimental program was conducted to study the damaging effects of tensile and compressive prestrains on the fatigue life of nickel-base, Inconel 718 superalloy at room temperature. To establish baseline fatigue behavior, virgin specimens with a solid uniform gage section were fatigued to failure under fully-reversed strain-control. Additional specimens were prestrained to 2 percent, 5 percent, and 10 percent (engineering strains) in the tensile direction and to 2 percent (engineering strain) in the compressive direction under stroke-control, and were subsequently fatigued to failure under fully-reversed strain-control. Experimental results are compared with estimates of remaining fatigue lives (after prestraining) using three life prediction approaches: (1) the Linear Damage Rule; (2) the Linear Strain and Life Fraction Rule; and (3) the nonlinear Damage Curve Approach. The Smith-Watson-Topper parameter was used to estimate fatigue lives in the presence of mean stresses. Among the cumulative damage rules investigated, best remaining fatigue life predictions were obtained with the nonlinear Damage Curve Approach.

Halford, Gary R.; Mcgaw, Michael A.; Kalluri, Sreeramesh

1995-01-01

211

Liana habitat and host preferences in northern temperate forests  

Microsoft Academic Search

Lianas and other climbers are important ecological and structural components of forest communities. Like other plants, their abundance in a given habitat depends on a variety of factors, such as light, soil moisture and nutrients. However, since lianas require external support, host tree characteristics also influence their distribution. Lianas are conspicuous life forms in tropical regions, but in temperate areas,

Stacey A. Leicht-Young; Noel B. Pavlovic; Krystalynn J. Frohnapple; Ralph Grundel

2010-01-01

212

Habitat Suitability Index Models: Bluegill  

USGS Publications Warehouse

A literature review encompassing habitat and species characteristics of the bluegill (Lepomis macrochirus) is followed by a discussion of the relationship of habitat variables and life requisites of this species. These data re then incorporated into Habitat Suitability Index models for the bluegill. This is one in a series of publications describing habitat requirements of selected fish and wildlife species. Numerous literature sources have been consulted in an effort to consolidate scientific data on species habitat relationships. These data have subsequently been synthesized into Habitat Suitability Index (HSI) models. the models are based on suitability indices formulated for variables found to affect the life cycle and survival of the species. The models are designed to be modified to evaluate specific habitat alterations using the HSI model building techniques presented in the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures.

Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

1982-01-01

213

Environmental perturbations influence telomere dynamics in long-lived birds in their natural habitat  

PubMed Central

Telomeres are regarded as markers of biological or cellular ageing because they shorten with the degree of stress exposure. Accordingly, telomere lengths should show different rates of change when animals are faced with different intensities of environmental challenges. However, a relationship between telomere length and the environment has not yet been tested within a natural setting. Here, we report longitudinal telomere dynamics in free-living, black-tailed gulls (Larus crassirostris) through the recapture of birds of a known age over 2–5 consecutive years. The rate of change in telomere lengths differed with respect to year but not sex or age. The years when gulls showed stable telomere lengths or increases in telomere lengths (from 2009 to 2010) and decreases in telomere lengths (from 2010 to 2011) were characterized by El Niño and the Great Japan Earthquake, respectively. Both events are suspected to have had long-lasting effects on food availability and/or weather conditions. Thus, our findings that telomere dynamics in long-lived birds are influenced by dramatic changes in environmental conditions highlight the importance of environmental fluctuations in affecting stress and lifespan. PMID:23945210

Mizutani, Yuichi; Tomita, Naoki; Niizuma, Yasuaki; Yoda, Ken

2013-01-01

214

Influences of Wildfire, Habitat Size, and Connectivity on Trout in Headwater Streams Revealed by Patterns of Genetic Diversity  

Microsoft Academic Search

Wildfire is an important natural process in many stream ecosystems, but the ability of fish to respond to wildfire-related disturbances is increasingly constrained by human activities that fragment and degrade stream habitats. In this study, we used molecular genetic markers (nuclear microsatellites) to examine the effects of wildfire and related disturbances along with habitat fragmentation on native rainbow trout in

Helen Neville; Jason Dunham; Amanda Rosenberger; John Umek; Brooke Nelson

2009-01-01

215

The influence of litter quality and micro-habitat on litter decomposition and soil properties in a silvopasture system  

NASA Astrophysics Data System (ADS)

Studies to understand litter processes and soil properties are useful for maintaining pastureland productivity as animal husbandry is the dominant occupation in the hot arid region. We aimed to quantify how micro-habitats and combinations of litters of the introduced leguminous tree Colophospermum mopane with the grasses Cenchrus ciliaris or Lasiurus sindicus influence decomposition rate and soil nutrient changes in a hot desert silvopasture system. Litter bags with tree litter alone (T), tree + C. ciliaris in 1:1 ratio (TCC) and tree + L. sindicus 1:1 ratio (TLS) litter were placed inside and outside of the C. mopane canopy and at the surface, 3-7 cm and 8-12 cm soil depths. We examined litter loss, soil fauna abundance, organic carbon (SOC), total (TN), ammonium (NH4-N) and nitrate (NO3-N) nitrogen, phosphorus (PO4-P), soil respiration (SR) and dehydrogenase activity (DHA) in soil adjacent to each litter bag. After 12 months exposure, the mean residual litter was 40.2% of the initial value and annual decomposition rate constant (k) was 0.98 (0.49-1.80). Highest (p < 0.01) litter loss was in the first four months, when faunal abundance, SR, DHA and humidity were highest but it decreased with time. These variables and k were highest under the tree canopies. The litter loss and k were highest (p < 0.01) in TLS under the tree canopy, but the reverse trend was found for litter outside the canopy. Faunal abundance, litter loss, k, nutrient release and biochemical activities were highest (p < 0.01) in the 3-7 cm soil layer. Positive correlations of litter loss and soil fauna abundance with soil nutrients, SR and DHA demonstrated the interactions of litter quality and micro-habitats together with soil fauna on increased soil fertility. These results suggest that a Colophospermum mopane and L. sindicus silvopasture system best promotes faunal abundance, litter decomposition and soil fertility. The properties of these species and the associated faunal resources may be utilised as an ecosystem-restoration strategy in designing a silvopasture system. This may help to control land degradation and increase productivity sustainably in this environment.

Tripathi, G.; Deora, R.; Singh, G.

2013-07-01

216

Lunar/Mars Surface Habitat Mockups Project  

NASA Technical Reports Server (NTRS)

Surface habitats play a centric role with respect to integration of the crew operations and supporting surface systems for external operations on the moon and Mars. Up to now the only planetary surface habitat NASA has ever developed is the 2-person, 3-day duration Lunar Module from the 1960 s-era Apollo Program. Today s National Vision for Space Exploration pushes far beyond the safety, performance and operational requirements of the Lunar Module, and NASA needs to develop a basis for making habitat design decisions Experience has shown that using mockups very early in a project s life cycle is extremely beneficial, providing data that influences requirements for human design, volumetrics, functionality, systems hardware and operations. Evaluating and comparing a variety of habitat configurations will provide NASA with a cost-effective basis for trades to support lunar and Martian habitat design selection. This paper describes the NASA project that recently has been created to undertake the development and evaluation of a series of planetary surface habitat mockups. This project is in direct response to the Advanced Space Platforms and Systems (ASPS) Element Program s request for novel systems approaches for robust and reconfigurable habitation systems.

Tri, Terry O.; Daues, Katherine R.

2005-01-01

217

Habitat quality and heterogeneity influence distribution and behavior in African buffalo (Syncerus caffer).  

PubMed

Top-down effects of predators on prey behavior and population dynamics have been extensively studied. However, some populations of very large herbivores appear to be regulated primarily from the bottom up. Given the importance of food resources to these large herbivores, it is reasonable to expect that forage heterogeneity (variation in quality and quantity) affects individual and group behaviors as well as distribution on the landscape. Forage heterogeneity is often strongly driven by underlying soils, so substrate characteristics may indirectly drive herbivore behavior and distribution. Forage heterogeneity may further interact with predation risk to influence prey behavior and distribution. Here we examine differences in spatial distribution, home range size, and grouping behaviors of African buffalo as they relate to geologic substrate (granite and basalt) and variation in food quality and quantity. In this study, we use satellite imagery, forage quantity data, and three years of radio-tracking data to assess how forage quality, quantity, and heterogeneity affect the distribution and individual and herd behavior of African buffalo. We found that buffalo in an overall poorer foraging environment keyed-in on exceptionally high-quality areas, whereas those foraging in a more uniform, higher-quality area used areas of below-average quality. Buffalo foraging in the poorer-quality environment had smaller home range sizes, were in smaller groups, and tended to be farther from water sources than those foraging in the higher-quality environment. These differences may be due to buffalo creating or maintaining nutrient hotspots (small, high-quality foraging areas) in otherwise low-quality foraging areas, and the location of these hotspots may in part be determined by patterns of predation risk. PMID:18543637

Winnie, John A; Cross, Paul; Getz, Wayne

2008-05-01

218

Genetic and Environmental Influences on Negative Life Events From Late Childhood to Adolescence  

PubMed Central

This multi-wave longitudinal study tested two quantitative genetic developmental models to examine genetic and environmental influences on exposure to negative dependent and independent life events. Participants (N = 457 twin pairs) completed measures of life events annually from ages 9 to 16. The same genetic factors influenced exposure to dependent events across time, and increased in magnitude during the transition to adolescence. Independent events were less genetically influenced than dependent events in boys, but not girls. Shared environmental influences decreased in magnitude as youth transitioned into adolescence. Nonshared environmental influences were mostly age-specific and contributed significantly to both types of events at all ages. Results provide theoretical implications for developmental risk pathways to stress exposure and stress-related psychopathology. PMID:23379294

Johnson, Daniel P.; Rhee, Soo Hyun; Whisman, Mark A.; Corley, Robin P.; Hewitt, John K.

2012-01-01

219

Influence of personality on sexual quality of life in epilepsy.  

PubMed

We prospectively investigated the effect of personality on sexual quality of life (SQOL) in 49 epilepsy patients (23 women). Fifteen patients had generalised epilepsy and 34 had focal epilepsy. SQOL was determined using the Derogatis Interview for Sexual Function - Self Report Inventory (DISF-SR) and personality was studied using the NEO five-factor inventory (NEO-FFI). Lower extraversion and female sex were factors associated with decreased SQOL, accounting for 22% of SQOL variance. Our results suggest that particularly introverted women with epilepsy may have an elevated risk of decreased SQOL. PMID:20497913

Mölleken, Daniela; Richter-Appelt, Hertha; Stodieck, Stefan; Bengner, Thomas

2010-06-01

220

Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem.  

PubMed

When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August-30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000-2011. We calculated Manly-Chesson (MC) indices for selectivity of WBP habitat and secure habitat (?500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas. PMID:24963393

Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D

2014-05-01

221

Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem  

PubMed Central

When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August–30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000–2011. We calculated Manly–Chesson (MC) indices for selectivity of WBP habitat and secure habitat (?500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas. PMID:24963393

Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D

2014-01-01

222

Investigating the Impact of UV Radiation on High-Altitude Shallow Lake Habitats, Life Diversity, and Life Survival Strategies: Clues for Mars' Past Habitability Potential?  

NASA Technical Reports Server (NTRS)

We present data and results from an ongoing project of astrobiological high-altitude expeditions investigating the highest and least explored perennial lakes on Earth in the Bolivian and Chilean Andes, including several volcanic crater lakes nearing and beyond 6,000 m in elevation. In the next five years, they will provide the first integrated long-term astrobiological characterization and monitoring of lacustrine environments and their biology for such altitude. These extreme lakes are natural laboratories. They provide the field data missing beyond 4,000 m to complete our understanding of terrestrial lakes and biota. Research on the effects of UV has been performed in lower altitude lakes and models of UV flux over time are being developed. Lakes showing a high content of dissolved organic material (DOM) shield organisms from UV. DOM acts as a natural sunscreen as it influences the water transparency, therefore is a determinant of photic zone depth. In sparsely vegetated alpine areas, lakes are clearer and offer less protection from UV to organisms living in the water. Transparent water and high UV irradiance may maximize the penetration and effect of UV radiation. Shallow-water communities in these lakes are particularly sensitive to UV radiation. The periphyton can live on various susbtrates. While on rocks, it includes immobile species that cannot seek low UV refuges unlike sediment-dwelling periphyton or alpine phytoflagellates which undergo vertical migration. Inhibition of algal photosynthesis by UV radiation has been documented in laboratory and showed that phytoplankton production is reduced by formation of nucleic acid lesions or production of peroxides and free oxygen radicals. of peroxides and free oxygen radicals. Our project is providing the field data that is missing from natural laboratories beyond 4,000 m and will complement the vision of the effects of UV on life and its adaptation modes (or lack thereof).

Cabrol, A.; Grin, E. A.; Hock, A.; Kiss, A.; Borics, G.; Kiss, K.; Acs, E.; Kovacs, G.; Chong, G.; Demergasso, C.

2004-01-01

223

The Influence of Habitat Quality on the Community Structure, Distribution Pattern, Condition, and Growth of Coral Reef Fish: A Case Study of Grunts (Haemulidae) from Antigua B.W.I, A Small Island System  

Microsoft Academic Search

The goal of this research was to determine the relative quality of near shore marine areas by investigating their influence on Haemulidae community structure, distribution pattern, condition, and growth. Habitat was defined at the small spatial scale of individual habitat types such as seagrass beds, mangroves and coral reefs, and at the broader spatial scale of the interconnection of these

Sherry Lynette Constantine

2008-01-01

224

Habitat of early life: Solar X-ray and UV radiation at Earth's surface 43.5 billion years ago  

E-print Network

02008, doi:10.1029/2006JE002784. 1. Introduction [2] Our understanding of the origin of life, as well to the origin of life [e.g., Miller and Urey, 1959]. However, on living tissue, the same radiation has is uncertain, but it is usually placed between 3.8 and 2.7 Ga. The evidence for an early origin of life, around

Utrecht, Universiteit

225

Collective Emotions Online and Their Influence on Community Life  

PubMed Central

Background E-communities, social groups interacting online, have recently become an object of interdisciplinary research. As with face-to-face meetings, Internet exchanges may not only include factual information but also emotional information – how participants feel about the subject discussed or other group members. Emotions in turn are known to be important in affecting interaction partners in offline communication in many ways. Could emotions in Internet exchanges affect others and systematically influence quantitative and qualitative aspects of the trajectory of e-communities? The development of automatic sentiment analysis has made large scale emotion detection and analysis possible using text messages collected from the web. However, it is not clear if emotions in e-communities primarily derive from individual group members' personalities or if they result from intra-group interactions, and whether they influence group activities. Methodology/Principal Findings Here, for the first time, we show the collective character of affective phenomena on a large scale as observed in four million posts downloaded from Blogs, Digg and BBC forums. To test whether the emotions of a community member may influence the emotions of others, posts were grouped into clusters of messages with similar emotional valences. The frequency of long clusters was much higher than it would be if emotions occurred at random. Distributions for cluster lengths can be explained by preferential processes because conditional probabilities for consecutive messages grow as a power law with cluster length. For BBC forum threads, average discussion lengths were higher for larger values of absolute average emotional valence in the first ten comments and the average amount of emotion in messages fell during discussions. Conclusions/Significance Overall, our results prove that collective emotional states can be created and modulated via Internet communication and that emotional expressiveness is the fuel that sustains some e-communities. PMID:21818302

Chmiel, Anna; Sienkiewicz, Julian; Thelwall, Mike; Paltoglou, Georgios; Buckley, Kevan; Kappas, Arvid; Ho?yst, Janusz A.

2011-01-01

226

Variables influencing the presence of subyearling fall Chinook salmon in shoreline habitats of the Hanford Reach, Columbia River  

USGS Publications Warehouse

Little information currently exists on habitat use by subyearling fall Chinook salmon Oncorhynchus tshawytscha rearing in large, main-stem habitats. We collected habitat use information on subyearlings in the Hanford Reach of the Columbia River during May 1994 and April-May 1995 using point abundance electrofishing. We analyzed measures of physical habitat using logistic regression to predict fish presence and absence in shoreline habitats. The difference between water temperature at the point of sampling and in the main river channel was the most important variable for predicting the presence and absence of subyearlings. Mean water velocities of 45 cm/s or less and habitats with low lateral bank slopes were also associated with a greater likelihood of subyearling presence. Intermediate-sized gravel and cobble substrates were significant predictors of fish presence, but small (256-mm) substrates were not. Our rearing model was accurate at predicting fish presence and absence using jackknifing (80% correct) and classification of observations from an independent data set (76% correct). The habitat requirements of fall Chinook salmon in the Hanford Reach are similar to those reported for juvenile Chinook salmon in smaller systems but are met in functionally different ways in a large river.

Tiffan, K.F.; Clark, L.O.; Garland, R.D.; Rondorf, D.W.

2006-01-01

227

Neighborhood Influences on Late Life Cognition in the ACTIVE Study  

PubMed Central

Low neighborhood-level socioeconomic status has been associated with poorer health, reduced physical activity, increased psychological stress, and less neighborhood-based social support. These outcomes are correlates of late life cognition, but few studies have specifically investigated the neighborhood as a unique source of explanatory variance in cognitive aging. This study supplemented baseline cognitive data from the ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly) study with neighborhood-level data to investigate (1) whether neighborhood socioeconomic position (SEP) predicts cognitive level, and if so, whether it differentially predicts performance in general and specific domains of cognition and (2) whether neighborhood SEP predicts differences in response to short-term cognitive intervention for memory, reasoning, or processing speed. Neighborhood SEP positively predicted vocabulary, but did not predict other general or specific measures of cognitive level, and did not predict individual differences in response to cognitive intervention. PMID:22966458

Sisco, Shannon M.; Marsiske, Michael

2012-01-01

228

SHORELINE, LAKE, AND ESTUARY SCALE HABITAT RESEARCH  

EPA Science Inventory

Habitat alteration is well recognized as a major cause of loss of living aquatic resources. Many fish and wildlife species depend on several habitats (or on habitat landscapes) in their life histories and migratory patterns. This NHEERL habitat research will develop stressor-re...

229

Relative importance of water chemistry and habitat to fish communities in headwater streams influenced by agricultural land use  

Technology Transfer Automated Retrieval System (TEKTRAN)

Channelized headwater streams are common throughout agricultural watersheds in the Midwestern United States. Understanding the relative impacts of agricultural contaminants and habitat degradation on the aquatic biota within agricultural headwater streams will provide information that can assist wi...

230

The influence of specific stressors, such as nutrient enrichment and physical habitat degradation, on biotic integrity requires  

E-print Network

throughout Illinois and examined relationships between macroinvertebrate community structure and numerous demonstrate that physical habitat degradation and nutrient pollution are important and often confounded determinants of biotic integrity in Illinois streams. In addition, we suggest that management of Midwestern

David, Mark B.

231

Relative influence of different habitat factors on creek chub population structure within channelized agricultural headwater streams in central Ohio  

Technology Transfer Automated Retrieval System (TEKTRAN)

Creek chubs (Semotilus atromaculatus) are commonly found within channelized agricultural headwater streams within the Midwestern United States. Understanding the relationships of this headwater fish species with different habitat factors will provide information that can assist with developing resto...

232

INFLUENCE OF STREAM NETWORK-SCALE HABITAT OF A COASTAL OREGON WATERSHED ON COHO SALMON AND OTHER NATIVE FISH  

EPA Science Inventory

EPA's Western Ecology Division is undertaking research addressing catchment-scale dynamics of freshwater habitat productivity for native fishes. Through partnerships with state and federal agencies and private landowners, current field efforts focus on linkages among stream chemi...

233

The influence of electron screening on half-lifes  

NASA Astrophysics Data System (ADS)

Electron screening strongly changes nuclear reaction cross sections at energies below 1000 times the screening energy Ue . It has been found that Ue can be one order of magnitude larger than predicted by theory [1] if the target atoms are hosted in a metallic environment. As a consequence, a change of lifetimes of low-energy ? and ? emitters may also be considered if they are situated in a metal. In addition, a temperature dependence of the screening effect has been proposed [2], dramatically changing some half-lifes if the metal is cooled [3, 5]. We checked these claims experimentally by measuring the decay rate of 22 Na in a piece of aluminum activated by a 70 MeV proton beam. We observed the 22 Na activity both at room temperature and when cooled down to nearly LN2 temperatures. As a result, a 10% increase as proposed by [3] can be clearly ? excluded. Furthermore, a 1/ T temperature dependence of Ue as it was proposed by [3, 5] when the Debye-Hückel model is applied is unlikely.

Ruprecht, Götz; Buchmann, L.; Hutcheon, D.; Ottewell, D.; Ruiz, C.; Walden, P.; Vockenhuber, C.; Czerski, K.

234

Ribbon of Life: An Agenda for Preserving Transboundary Migratory Bird Habitat on the Upper San Pedro River  

NSDL National Science Digital Library

The Commission for Environmental Cooperation (CEC) has released this report "to foster cooperative efforts to ensure the continued health of the San Pedro Watershed." Over the past century, the ecological integrity of the Upper San Pedro River has declined substantially; the loss of riparian habitat has important implications for migratory birds. The report (.pdf format), which may be downloaded at the site, calls for coordinated management of the watershed, further research in certain key areas, greater collaboration among stakeholders, and increased public education efforts.

235

Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.  

SciTech Connect

This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration scenarios on habitat opportunity and the estuary's productive capacity for juvenile salmon. The underlying modeling system is part of the SATURN1coastal-margin observatory [1]. SATURN relies on 3D numerical models [2, 3] to systematically simulate and understand baroclinic circulation in the Columbia River estuary-plume-shelf system [4-7] (Fig. 1). Multi-year simulation databases of circulation are produced as an integral part of SATURN, and have multiple applications in understanding estuary/plume variability, the role of the estuary and plume on salmon survival, and functional changes in the estuary-plume system in response to climate and human activities.

Baptista, António M. [Oregon Health & Science University, Science and Technology Center for Coastal Margin Observation and Prediction

2009-08-02

236

[Influence of socioeconomic factors on the quality of life of elderly hypertensive individuals].  

PubMed

This study sought to evaluate the association between socioeconomic variables and the quality of life of elderly hypertensive patients treated under the Family Health Program in the city of Montes Claros, Minas Gerais, Brazil. An analytical cross study was conducted in a representative sample of 294 elderly hypertensive patients. Data were collected using a questionnaire on socioeconomic characteristics and quality of life (MINICHAL). The data were analyzed using the nonparametric Mann-Whitney and Kuskall-Wallis tests. The results showed that marital status, religion and education affect the quality of life of elderly hypertensive patients in a statistically significant way. Elderly hypertensive patients who were single/divorced/widowed, evangelical, spiritualist and belonging to other religious bodies, illiterate achieved lower scores in terms of quality of life. For the remaining variables, there was no statistical association. The conclusion, drawn is that socioeconomic factors such as marital status, education and religion influence the quality of life of elderly hypertensive patients. PMID:25119088

Andrade, João Marcus Oliveira; Rios, Lorena Roseli; Teixeira, Larissa Silva; Vieira, Fernanda Silva; Mendes, Danilo Cangussu; Vieira, Maria Aparecida; Silveira, Marise Fagundes

2014-08-01

237

Early Life Stress as an Influence on Limbic Epilepsy: An Hypothesis Whose Time has Come?  

PubMed Central

The pathogenesis of mesial temporal lobe epilepsy (MTLE), the most prevalent form of refractory focal epilepsy in adults, is thought to begin in early life, even though seizures may not commence until adolescence or adulthood. Amongst the range of early life factors implicated in MTLE causation (febrile seizures, traumatic brain injury, etc.), stress may be one important contributor. Early life stress is an a priori agent deserving study because of the large amount of neuroscientific data showing enduring effects on structure and function in hippocampus and amygdala, the key structures involved in MTLE. An emerging body of evidence directly tests hypotheses concerning early life stress and limbic epilepsy: early life stressors, such as maternal separation, have been shown to aggravate epileptogenesis in both status epilepticus and kindling models of limbic epilepsy. In addition to elucidating its influence on limbic epileptogenesis itself, the study of early life stress has the potential to shed light on the psychiatric disorder that accompanies MTLE. For many years, psychiatric comorbidity was viewed as an effect of epilepsy, mediated psychologically and/or neurobiologically. An alternative – or complementary – perspective is that of shared causation. Early life stress, implicated in the pathogenesis of several psychiatric disorders, may be one such causal factor. This paper aims to critically review the body of experimental evidence linking early life stress and epilepsy; to discuss the direct studies examining early life stress effects in current models of limbic seizures/epilepsy; and to suggest priorities for future research. PMID:19838325

Koe, Amelia S.; Jones, Nigel C.; Salzberg, Michael R.

2009-01-01

238

The Influence of Dietary Fat Source on Life Span in Calorie Restricted Mice.  

PubMed

Calorie restriction (CR) without malnutrition extends life span in several animal models. It has been proposed that a decrease in the amount of polyunsaturated fatty acids (PUFAs), and especially n-3 fatty acids, in membrane phospholipids may contribute to life span extension with CR. Phospholipid PUFAs are sensitive to dietary fatty acid composition, and thus, the purpose of this study was to determine the influence of dietary lipids on life span in CR mice. C57BL/6J mice were assigned to four groups (a 5% CR control group and three 40% CR groups) and fed diets with soybean oil (high in n-6 PUFAs), fish oil (high in n-3 PUFAs), or lard (high in saturated and monounsaturated fatty acids) as the primary lipid source. Life span was increased (p < .05) in all CR groups compared to the Control mice. Life span was also increased (p < .05) in the CR lard mice compared to animals consuming either the CR fish or soybean oil diets. These results indicate that dietary lipid composition can influence life span in mice on CR, and suggest that a diet containing a low proportion of PUFAs and high proportion of monounsaturated and saturated fats may maximize life span in animals maintained on CR. PMID:25313149

López-Domínguez, José A; Ramsey, Jon J; Tran, Dianna; Imai, Denise M; Koehne, Amanda; Laing, Steven T; Griffey, Stephen M; Kim, Kyoungmi; Taylor, Sandra L; Hagopian, Kevork; Villalba, José M; López-Lluch, Guillermo; Navas, Plácido; McDonald, Roger B

2014-10-13

239

Habitat stress initiates changes in composition, CO2 gas exchange and C-allocation as life traits in biological soil crusts.  

PubMed

Biological soil crusts (BSC) are the dominant functional vegetation unit in some of the harshest habitats in the world. We assessed BSC response to stress through changes in biotic composition, CO2 gas exchange and carbon allocation in three lichen-dominated BSC from habitats with different stress levels, two more extreme sites in Antarctica and one moderate site in Germany. Maximal net photosynthesis (NP) was identical, whereas the water content to achieve maximal NP was substantially lower in the Antarctic sites, this apparently being achieved by changes in biomass allocation. Optimal NP temperatures reflected local climate. The Antarctic BSC allocated fixed carbon (tracked using (14)CO2) mostly to the alcohol soluble pool (low-molecular weight sugars, sugar alcohols), which has an important role in desiccation and freezing resistance and antioxidant protection. In contrast, BSC at the moderate site showed greater carbon allocation into the polysaccharide pool, indicating a tendency towards growth. The results indicate that the BSC of the more stressed Antarctic sites emphasise survival rather than growth. Changes in BSC are adaptive and at multiple levels and we identify benefits and risks attached to changing life traits, as well as describing the ecophysiological mechanisms that underlie them. PMID:24694713

Colesie, Claudia; Green, T G Allan; Haferkamp, Ilka; Büdel, Burkhard

2014-10-01

240

Spatial scale-dependent habitat heterogeneity influences submarine canyon macrofaunal abundance and diversity off the Main and Northwest Hawaiian Islands  

NASA Astrophysics Data System (ADS)

The mapping of biodiversity on continental margins on landscape scales is highly relevant to marine spatial planning and conservation. Submarine canyons are widespread topographic features on continental and island margins that enhance benthic biomass across a range of oceanic provinces and productivity regimes. However, it remains unclear whether canyons enhance faunal biodiversity on landscape scales relevant to marine protected area (MPA) design. Furthermore, it is not known which physical attributes and heterogeneity metrics can provide good surrogates for large-scale mapping of canyon benthic biodiversity. To test mechanistic hypotheses evaluating the role of different canyon-landscape attributes in enhancing benthic biodiversity at different spatial scales we conducted 34 submersible dives in six submarine canyons and nearby slopes in the Hawaiian archipelago, sampling infaunal macrobenthos in a depth-stratified sampling design. We employed multivariate multiple regression models to evaluate sediment and topographic heterogeneity, canyon transverse profiles, and overall water mass variability as potential drivers of macrobenthic community structure and species richness. We find that variables related to habitat heterogeneity at medium (0.13 km2) and large (15-33 km2) spatial scales such as slope, backscatter reflectivity and canyon transverse profiles are often good predictors of macrobenthic biodiversity, explaining 16-30% of the variance. Particulate organic carbon (POC) flux and distance from shore are also important variables, implicating food supply as a major predictor of canyon biodiversity. Canyons off the high Main Hawaiian Islands (Oahu and Moloka'i) are significantly affected by organic enrichment, showing enhanced infaunal macrobenthos abundance, whereas this effect is imperceptible around the low Northwest Hawaiian Islands (Nihoa and Maro Reef). Variable canyon alpha-diversity and high rates of species turnover (beta-diversity), particularly for polychaetes, suggest that canyons play important roles in maintaining high levels of regional biodiversity in the extremely oligotrophic system of the North Pacific Subtropical Gyre. This information is of key importance to the process of MPA design, suggesting that canyon habitats be explicitly included in marine spatial planning. The low-islands of Nihoa and Maro Reef in the NWHI showed a lack of sustained input of terrestrial and macrolagae detritus, likely having an influence on the observed low macrofaunal abundances (see further discussion of ‘canyon effects’ in Section 4.3), and showing the fundamental role of coastal landscape characteristics in determining the amount and nature of allochthonous organic matter entering the system. Total and highly-mobile invertebrate megafauna abundances were two to three times higher in the submarine canyons and slopes of the MHI contrasted with the NWHI (Vetter et al., 2010), also demonstrating the role of this larger contribution of terrestrial and coastal organic enrichment in the MHI contrasted with the NWHI.

De Leo, Fabio C.; Vetter, Eric W.; Smith, Craig R.; Rowden, Ashley A.; McGranaghan, Matthew

2014-06-01

241

Workaholism and work–life imbalance: Does cultural origin influence the relationship?  

Microsoft Academic Search

In recent years, workaholism has become prevalent throughout organizations and has captured the attention of organizational leaders as well as the academic and scientific communities. Most research in this area has focused on the negative consequences of workaholism, specifically work–life imbalance. One area of research that has largely been ignored is the potential influence of demographic variables on the relationship

Shahnaz Aziz; Carrie T. Adkins; Alan G. Walker; Karl L. Wuensch

2010-01-01

242

The Influence of Western Society's Construction of a Healthy Daily Life on the Conceptualisation of Occupation  

Microsoft Academic Search

This article proposes that the current conceptualisation of occupation within the dominant Anglophone literature reflects central elements of Western society's construction of a ‘healthy’ daily life, the ‘ideal’ and expected way to live. Contemporary theories of social action are used to describe the structuring influence of social institutions on daily activity. Four of the commonly identified characteristics of occupation, that

Sarah Kantartzis; Matthew Molineux

2011-01-01

243

Factors Influencing Quality of Life of Hungarian Postmenopausal Women Screened by Osteodensitometry  

ERIC Educational Resources Information Center

The aim of our study was to evaluate factors influencing health related quality of life in Hungarian postmenopausal women who underwent osteodensitometry. A questionnaire-based cross-sectional study was carried out; 359 women aged over 40 years were involved, attending the outpatient Bone Densitometry Centre of Szeged. Two kinds of tools were…

Maroti-Nagy, Agnes; Paulik, Edit

2011-01-01

244

Late-life depression and mortality: influence of gender and antidepressant use  

E-print Network

Late-life depression and mortality: influence of gender and antidepressant use JOANNE RYAN The British Journal of Psychiatry 2008;192:12-8 #12;Background: Depression may increase the risk of mortality at risk of dying, as a function of depressive symptoms, gender and antidepressant use. Method: Adjusted

245

Late life depression and incident activity limitations: influence of gender and symptom Isabelle Carrirea,b,*  

E-print Network

1 Late life depression and incident activity limitations: influence of gender and symptom severity Background Mental disorders, especially depression, are one of the principal causes of disablement. Previous baseline depressive symptomatology and activity limitations were examined in a community-dwelling elderly

Paris-Sud XI, Université de

246

The Life Skills Program IPSY: Positive Influences on School Bonding and Prevention of Substance Misuse  

ERIC Educational Resources Information Center

The present study investigated whether a life skills program (LSP) for the prevention of adolescent substance misuse can have positive influences on a school context and on school bonding. The study also explored whether effects on alcohol use are mediated by positive effects on school bonding resulting from program participation. The LSP IPSY…

Wenzel, Victoria; Weichold, Karina; Silbereisen, Rainer K.

2009-01-01

247

Ethnic differences in influences on quality of life at older ages: a quantitative analysis  

Microsoft Academic Search

This article sets out to examine ethnic differences in the key influences on quality of life for older people in the context of the increasing health and wealth of British older people generally and the ageing of the post-1945 migrants. It is based on secondary multivariate analysis of the Fourth National Survey of Ethnic Minorities of England and Wales. Respondents

MADHAVI BAJEKAL; DAVID BLANE; INI GREWAL; SAFFRON KARLSEN; JAMES NAZROO

2004-01-01

248

Factors Influencing Health-Related Quality of Life of Overweight and Obese Children in South Korea  

ERIC Educational Resources Information Center

The purpose of this study was to identify factors influencing health-related quality of life (HRQoL) of overweight and obese children in Korea. This study employed a cross-sectional descriptive study design. A total of 132 overweight and obese children participated in the study. Anthropometric measurements included body mass index, percent body…

Kim, Hee Soon; Park, Jiyoung; Ma, Yumi; Ham, Ok Kyung

2013-01-01

249

Influence of correlations between stresses on calculated fatigue life of machine elements  

Microsoft Academic Search

The correlation between components of the random stress tensor and its influence on the calculated fatigue life of machine elements were analysed. Three covariance matrices of components of biaxial stress state were considered. They were determined from measurements of strains in an element of a vibrating screen for aggregate, in the back wall of a bus, and in a welded

T. ?agoda; E. Macha; A. Dragon; J. Petit

1996-01-01

250

Family and television influences on materialism: a cross-cultural life-course approach  

Microsoft Academic Search

Purpose – The purpose of this study is to examine whether the development of materialistic values in early life reflects cultural norms or is the outcome of media and family influences. It seeks to examine the role of family communication and television, which were found to promote materialistic values in individualistic countries, by assessing their effects on youths in four

George Moschis; Fon Sim Ong; Anil Mathur; Takako Yamashita; Sarah Benmoyal-Bouzaglo

2011-01-01

251

Factors Influencing Older Worker Quality of Life and Intent to Continue to Work  

ERIC Educational Resources Information Center

High turnover has been a major problem in healthcare organizations. The purpose of this study was to examine the relationship among job characteristics, social support, and organizational characteristics on quality of the working life. Subsequently, the intent was to examine how those factors collectively influence turnover intention. A…

Spokus, Diane

2008-01-01

252

RISKS OF TOXIC CONTAMINANTS TO EXPLOITED FISH POPULATIONS: INFLUENCE OF LIFE HISTORY, DATA UNCERTAINTY, AND EXPLOITATION  

EPA Science Inventory

Use of toxicity test data for population-level risk assessment was investigated as follows: 1) the influence of life history characteristics of menhaden and striped bass on vulnerability of contaminant-induced stress, (2) the importance of test data availability, and (3) the infl...

253

Influence of Life Stress on Depression: Moderation by a Polymorphism in the 5-HTT Gene  

Microsoft Academic Search

In a prospective-longitudinal study of a representative birth cohort, we tested why stressful experiences lead to depression in some people but not in others. A functional polymorphism in the promoter region of the serotonin transporter (5-HTT) gene was found to moderate the influence of stressful life events on depression. Individuals with one or two copies of the short allele of

Avshalom Caspi; Karen Sugden; Terrie E. Moffitt; Alan Taylor; Ian W. Craig; HonaLee Harrington; Joseph McClay; Jonathan Mill; Judy Martin; Antony Braithwaite; Richie Poulton

2003-01-01

254

Influence of host habitat on the occurrence of gill monogeneans Pseudodactylogyrus spp. on wild Japanese eels Anguilla japonica.  

PubMed

With technological improvements in otolith microchemical analysis, the flexible use of habitat from coastal marine to fresh waters has been discovered in Japanese eels Anguilla japonica. We examined the occurrence of 3 congeneric gill monogeneans-Pseudodactylogyrus anguillae, P. bini, and P. kamegaii-on wild Japanese eels, in relation to the host's flexibility. From April 2008 to October 2009, 114 eels were collected from a brackish-water cove and 2 rivers flowing into the cove in Ehime Prefecture, western Japan. Based on otolith microchemical analysis, the eels were discriminated according to the following 4 types of habitat use: freshwater residents (Type I), individuals utilizing low-salinity habitats (Type II), downstream habitat-shifters (Type III), and cove residents (Type IV). P. anguillae occurred mainly on Type I and II eels, while P. bini was primarily found on Type I eels. In contrast, P. kamegaii occurred mainly on Type III and IV eels. Thus, we conclude that species composition and infection levels of Pseudodactylogyrus spp. clearly differed with habitat-use patterns of Japanese eels. Also, since P. anguillae was scarcely found on either Type III or IV eels, this study suggests that previous identifications of monogeneans collected from European brackish-water localities as P. anguillae may require verification. PMID:22885512

Katahira, Hirotaka; Mizuno, Kouki; Umino, Tetsuya; Nagasawa, Kazuya

2012-08-13

255

Negative emotionality and disconstraint influence PTSD symptom course via exposure to new major adverse life events.  

PubMed

Identifying the factors that influence stability and change in chronic posttraumatic stress disorder (PTSD) is important for improving clinical outcomes. Using a cross-lagged design, we analyzed the reciprocal effects of personality and PTSD symptoms over time and their effects on stress exposure in a sample of 222 trauma-exposed veterans (ages 23-68; 90.5% male). Personality functioning and PTSD were measured approximately 4 years apart, and self-reported exposure to major adverse life events during the interim was also assessed. Negative emotionality positively predicted future PTSD symptoms, and this effect was partially mediated by exposure to new events. Constraint (negatively) indirectly affected PTSD via its association with exposure to new events. There were no significant effects of positive emotionality nor did PTSD symptom severity exert influences on personality over time. Results indicate that high negative affect and disconstraint influence the course of PTSD symptoms by increasing exposure to stressful life events. PMID:25659969

Sadeh, Naomi; Miller, Mark W; Wolf, Erika J; Harkness, Kate L

2015-04-01

256

Habitat Suitability Index Models: Smallmouth Buffalo  

USGS Publications Warehouse

This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Smallmouth buffalo (Ictiobus bubalus) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Edwards, Elizabeth A.; Twomey, Katie

1982-01-01

257

Habitat Suitability Index Models: Black Bullhead  

USGS Publications Warehouse

This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Black bullhead (Ictalurus melas) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Stuber, Robert J.

1982-01-01

258

Habitat Suitability Index Models: Green Sunfish  

USGS Publications Warehouse

This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Green sunfish (Lepomis cyanellus) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

1982-01-01

259

Habitat Suitability Index Models: Common Carp  

USGS Publications Warehouse

This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Common carp (Cyprinus carpio) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Edwards, Elizabeth A.; Twomey, Katie

1982-01-01

260

Habitat Suitability Index Models: Largemouth Bass  

USGS Publications Warehouse

This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Largemouth bass (Micropterus salmoides) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

1982-01-01

261

Does Thermal Variability Experienced at the Egg Stage Influence Life History Traits across Life Cycle Stages in a Small Invertebrate?  

PubMed Central

Although effects of thermal stability on eggs have often been considered in vertebrates, there is little data thermal stability in insect eggs even though these eggs are often exposed in nature to widely fluctuating ambient conditions. The modularity of development in invertebrates might lead to compensation across life cycle stages but this remains to be tested particularly within the context of realistic temperature fluctuations encountered in nature. We simulated natural temperate fluctuations on eggs of the worldwide cruciferous insect pest, the diamondback moth (DBM), Plutella xylostella (L.), while maintaining the same mean temperature (25°C±0°C, 25±4°C, 25±6°C, 25±8°C, 25±10°C, 25±12°C) and assessed egg development, survival and life history traits across developmental stages. Moderate fluctuations (25±4°C, 25±6°C) did not influence performance compared to the constant temperature treatment, and none of the treatments influenced egg survival. However the wide fluctuating temperatures (25±10°C, 25±12°C) slowed development time and led to an increase in pre-pupal mass, although these changes did not translate into any effects on longevity or fecundity at the adult stage. These findings indicate that environmental effects can extend across developmental stages despite the modularity of moth development but also highlight that there are few fitness consequences of the most variable thermal conditions likely to be experienced by Plutella xylostella. PMID:24911213

Xing, Kun; Hoffmann, Ary A.; Ma, Chun-Sen

2014-01-01

262

Aquatic Habitats  

NSDL National Science Digital Library

The site offers information on Australia's aquatic habitats and their protection, management, and rehabilitation. Visitors will also find instructions for reporting fish kills and information on how to help protect and conserve fish habitats.

263

Temperature Influences Selective Mortality during the Early Life Stages of a Coral Reef Fish  

PubMed Central

For organisms with complex life cycles, processes occurring at the interface between life stages can disproportionately impact survival and population dynamics. Temperature is an important factor influencing growth in poikilotherms, and growth-related processes are frequently correlated with survival. We examined the influence of water temperature on growth-related early life history traits (ELHTs) and differential mortality during the transition from larval to early juvenile stage in sixteen monthly cohorts of bicolor damselfish Stegastes partitus, sampled on reefs of the upper Florida Keys, USA over 6 years. Otolith analysis of settlers and juveniles coupled with environmental data revealed that mean near-reef water temperature explained a significant proportion of variation in pelagic larval duration (PLD), early larval growth, size-at-settlement, and growth during early juvenile life. Among all cohorts, surviving juveniles were consistently larger at settlement, but grew more slowly during the first 6 d post-settlement. For the other ELHTs, selective mortality varied seasonally: during winter and spring months, survivors exhibited faster larval growth and shorter PLDs, whereas during warmer summer months, selection on PLD reversed and selection on larval growth became non-linear. Our results demonstrate that temperature not only shapes growth-related traits, but can also influence the direction and intensity of selective mortality. PMID:21559305

Rankin, Tauna L.; Sponaugle, Su

2011-01-01

264

Early Life Dietary Spray Dried Plasma Influences Immunological and Intestinal Injury Responses to Later Life Salmonella Typhimurium Challenge  

PubMed Central

Increasing evidence supports that early life environmental influences, including nutrition and stress, impact long-term health outcomes and disease susceptibility. The objective of the current study was to determine whether dietary spray-dried plasma (SDP) fed during the first 2 weeks post-weaning (PW) influences subsequent immunological and intestinal injury responses to S. Typhimurium challenge. Thirty two piglets (16–17 d of age) were weaned onto nursery diets containing 0% SDP, 2.5% SDP (fed for 7 d PW), or 5% SDP (for 14 d PW) and were then fed control diets (without SDP), for the remainder of the experiment. At 34 d PW (50 d of age), pigs were challenged with 3×109 cfu S. Typhimurium. A control group (non-challenged) that was fed 0% SDP in the nursery was included. At 2 d post-challenge, distal ileum was harvested for measurement of inflammatory, histological, and intestinal physiological parameters. S. Typhimurium challenge induced elevated ileal histological scores, myeloperoxidase (MPO), IL-8, and TNF, and increased intestinal permeability (indicated by reduced transepithelial voltage (PD) and elevated FD4 flux rates). Compared with S. Typhimurium-challenged controls (0% SDP), pigs fed 5% SDP-14 d exhibited reduced ileal histological scores, MPO, IL-8, and FD4 flux rates. Pigs fed 5% SDP-14 d in the nursery exhibited increased levels of plasma and ileal TNF? in response to challenge, compared with other treatments. These results indicate that inclusion of SDP into PW diets can have influence subsequent immunological responses and intestinal injury induced by later life S. Typhimurium challenge. PMID:25671331

Boyer, P.E.; D’Costa, S.; Edwards, L.L.; Milloway, M.; Susick, E.; Borst, L.B.; Thakur, S.; Campbell, J.M.; Crenshaw, J.D.; Polo, J.; Moeser, A.J.

2015-01-01

265

Ontogenetic Habitat Shifts of Juvenile Bear Lake Sculpin  

Microsoft Academic Search

Bear lake sculpin Cottus extensus exhibit ontogenetic habitat shifts during their initial year of life. Distribution and habitat switching was measured with bimonthly bottom-trawl surveys repeated throughout the summer. Patterns of daily growth increments on otoliths were used to measure the history of habitat residence, individual size at the time of the habitat switch, and habitat-specific growth rates. Laboratory experiments

James R. Ruzycki; Wayne A. Wurtsbaugh

1999-01-01

266

Surface Habitat Systems  

NASA Technical Reports Server (NTRS)

The Surface Habitat Systems (SHS) Focused Investment Group (FIG) is part of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) effort to provide a focused direction and funding to the various projects that are working on human surface habitat designs and technologies for the planetary exploration missions. The overall SHS-FIG effort focuses on directing and guiding those projects that: 1) develop and demonstrate new surface habitat system concepts, innovations, and technologies to support human exploration missions, 2) improve environmental systems that interact with human habitats, 3) handle and emplace human surface habitats, and 4) focus on supporting humans living and working in habitats on planetary surfaces. The activity areas of the SHS FIG described herein are focused on the surface habitat project near-term objectives as described in this document. The SHS-FIG effort focuses on mitigating surface habitat risks (as identified by the Lunar Surface Systems Project Office (LSSPO) Surface Habitat Element Team; and concentrates on developing surface habitat technologies as identified in the FY08 gap analysis. The surface habitat gap assessment will be updated annually as the surface architecture and surface habitat definition continues to mature. These technologies are mapped to the SHS-FIG Strategic Development Roadmap. The Roadmap will bring to light the areas where additional innovative efforts are needed to support the development of habitat concepts and designs and the development of new technologies to support of the LSSPO Habitation Element development plan. Three specific areas of development that address Lunar Architecture Team (LAT)-2 and Constellation Architecture Team (CxAT) Lunar habitat design issues or risks will be focused on by the SHS-FIG. The SHS-FIG will establish four areas of development that will help the projects prepare in their planning for surface habitat systems development. Those development areas are the 1) surface habitat concept definition, 2) inflatable surface habitat development, and 3) autonomous habitat operations, and 4) cross-cutting / systems engineering. In subsequent years, the SHS-FIG will solicit a call for innovations and technologies that will support the development of these four development areas. The other development areas will be assessed yearly and identified on the SHS-FIG s Strategic Development Roadmap. Initial investment projects that are funded by the Constellation Program Office (CxPO), LSSPO, or the Exploration Technology Development Projects (ETDP) will also be included on the Roadmap. For example, in one or two years from now, the autonomous habitat operations and testbed would collaborations with the Integrated Systems Health Management (ISHM) and Automation for Operations ETDP projects, which will give the surface habitat projects an integrated habitat autonomy testbed to test software and systems. The SHS-FIG scope is to provide focused direction for multiple innovations, technologies and subsystems that are needed to support humans at a remote planetary surface habitat during the concept development, design definition, and integration phases of that project. Subsystems include: habitability, lightweight structures, power management, communications, autonomy, deployment, outfitting, life support, wireless connectivity, lighting, thermal and more.

Kennedy, Kriss J.

2009-01-01

267

Cultural influences on children's understanding of the human body and the concept of life.  

PubMed

This study aimed to identify the age by which children begin to demonstrate a biological understanding of the human body and the idea that the purpose of body functioning is to maintain life. The study also explored the influence of education, culturally specific experiences and religion on knowledge acquisition in this domain. Children aged between 4 and 7 years from three different cultural backgrounds (White British, British Muslim, and Pakistani Muslim) were interviewed about the human body and its functioning. At least half of the 4- to 5-year-olds in each cultural group, and almost all 6- to 7-year-olds, referred to the maintenance of life when explaining organs' functions and so were classified as 'life theorizers'. Pakistani Muslim children gave fewer biological responses to questions about organs' functions and the purpose of eating and breathing, but referred to life more than their British counterparts. Irrespective of cultural group, older children understood organ location and function better than younger children. These findings support Jaakkola and Slaughter's (2002, Br. J. Dev. Psychol., 20, 325) view that children's understanding of the body as a 'life machine' emerges around the ages of 4-5 years. They also suggest that, despite many similarities in children's ideas cross-culturally, different educational input and culturally specific experiences influence aspects of their biological understanding. PMID:24628109

Panagiotaki, Georgia; Nobes, Gavin

2014-09-01

268

The influence of habitat selection and density on the population dynamics of stony coral species of the  

E-print Network

population size, potential reproductive output, and population structure for several species across sandy recorded for several island bank systems across habitat types in the central Bahamas. Nearshore patch reefs of larger colony sizes observed in dense patch reefs indicate a high sexual reproductive potential

Sealey, Kathleen Sullivan

269

INFLUENCE OF SALINITY ON HABITAT UTILIZATION OF OYSTER REEFS BY RESIDENT FISHES AND DECAPOD CRUSTACEANS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA.  

EPA Science Inventory

A spatiotemporal comparison of habitat suitability of oyster reefs for fishes and decapod crustaceans was conducted for the lower Caloosahatchee Estuary, Florida. Lift nets (1-m2) containing 5 liters (volume displacement) of oyster clusters were deployed monthly at three sites al...

270

Local Habitat, Watershed, and Biotic Factors Influencing the Spread of Hybridization between Native Westslope Cutthroat Trout and Introduced Rainbow Trout  

Microsoft Academic Search

The invasion of nonnative fishes in freshwater systems is often facilitated by the interaction of biotic and abiotic factors operating at multiple spatial and temporal scales. We evaluated the association of local habitat features (width, gradient, and elevation), watershed characteristics (mean and maximum summer water temperatures, the number of road crossings, and road density), and biotic factors (the distance to

Clint C. Muhlfeld; Thomas E. McMahon; Matthew C. Boyer; Robert E. Gresswell

2009-01-01

271

Plant epiphytism in semiarid conditions revealed the influence of habitat and climate variables on AM fungi communities distribution  

NASA Astrophysics Data System (ADS)

In semiarid Mediterranean ecosystems epiphytic plant species are practically absent and only some species of palm-trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study we focused in Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils, Our aim was to determine the possible presence of AMF in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AM fungi as determined by microscopic observation, all epiphytic and terrestrial samples analysed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF OTUs. The AMF community composition was clearly different between epiphytic and terrestrial root samples and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats.

Torrecillas, Emma; Torres, Pilar; Díaz, Gisela; del Mar Alguacil, Maria; Querejeta, Jose Ignacio; García, Fuensanta; Roldán, Antonio

2014-05-01

272

Longitudinal variation and habitat associations of small fishes in the Bighorn River, Wyoming: influences of river regulation and introduced fishes  

Microsoft Academic Search

We assessed variation in longitudinal distributions of native and introduced fishes and their occurrences in different habitat types downstream from Boysen Dam in the Bighorn River, Wyoming. The closure of Boysen Dam in 1952 and construction of three downstream water diversion dams have led to channel changes in the Bighorn River causing reductions in the numbers and areas of side

Jerry W. Wilhite; Wayne A. Hubert

2011-01-01

273

On the salty side of life: molecular, physiological and anatomical adaptation and acclimation of trees to extreme habitats.  

PubMed

Saline and sodic soils that cannot be used for agriculture occur worldwide. Cultivating stress-tolerant trees to obtain biomass from salinized areas has been suggested. Various tree species of economic importance for fruit, fibre and timber production exhibit high salinity tolerance. Little is known about the mechanisms enabling tree crops to cope with high salinity for extended periods. Here, the molecular, physiological and anatomical adjustments underlying salt tolerance in glycophytic and halophytic model tree species, such as Populus euphratica in terrestrial habitats, and mangrove species along coastlines are reviewed. Key mechanisms that have been identified as mediating salt tolerance are discussed at scales from the genetic to the morphological level, including leaf succulence and structural adjustments of wood anatomy. The genetic and transcriptomic bases for physiological salt acclimation are salt sensing and signalling networks that activate target genes; the target genes keep reactive oxygen species under control, maintain the ion balance and restore water status. Evolutionary adaptation includes gene duplication in these pathways. Strategies for and limitations to tree improvement, particularly transgenic approaches for increasing salt tolerance by transforming trees with single and multiple candidate genes, are discussed. PMID:25159181

Polle, Andrea; Chen, Shaoliang

2014-08-27

274

Life in the Mosaic: Predicting changes in estuarine nursery production for juvenile fishes in response to sea-level rise with a landscape-based habitat production model  

EPA Science Inventory

Identification of critical habitat in estuarine fish nursery areas is an important conservation and management objective, yet response to changes in critical habitat is both equally important and harder to predict. Habitat can be viewed as a mosaic of both temporally variable en...

275

Do omnivorous shrimp influence mayfly nymph life history traits in a tropical island stream?  

PubMed

Interspecific interactions can play an important role in determining habitat selection and resource use between competing species. We examined interactions between an omnivorous shrimp and a grazing mayfly, two co-dominant taxa found in Puerto Rican headwater streams, to assess how predator presence may influence mayfly resource use and instantaneous growth in a tropical rainforest ecosystem. We conducted a series of behavioral and growth experiments to determine the effects of the freshwater shrimp, Xiphocaris elongata, on the growth rate and resource selection of mayfly nymphs in the family Leptophlebiidae. For resource choice assessments, we conducted a series of five day laboratory experiments where mayflies were given access to two resource substrate choices (cobble vs. leaves) in the presence or absence of shrimp. To assess for the effects of shrimp on mayfly fitness, we measured mayfly growth in laboratory aquaria after five days using four treatments (cobble, leaves, cobble + leaves, no resource) in the presence or absence of shrimp. In resource choice experiments, mayflies showed preference for cobble over leaf substrata (p < 0.05) regardless of the presence of shrimps, however, the preference for cobble was significantly greater when shrimp were present in the leaf habitat. In growth experiments, there were no statistical differences in mayfly growth in the presence or absence of shrimp (p = 0.07). However, we measured increased mayfly nymph growth in the absence of predators and when both cobble and leaves were available. Our results suggest that interspecific interactions between these taxa could potentially influence organic matter resource dynamics (e.g., leaf litter processing and export) in Puerto Rican streams. PMID:25189068

Macías, Nicholas A; Colón-Gaud, Checo; Duggins, Jonathan W; Ramírez, Alonso

2014-04-01

276

Challenges and Novel Approaches in the Epidemiological Study of Early Life Influences on Later Disease  

Microsoft Academic Search

The influence of factors acting during early life on health outcomes of offspring is of considerable research and public health\\u000a interest. There are, however, methodological challenges in establishing robust causal links, since exposures often act many\\u000a decades before outcomes of interest, and may also be strongly related to other factors, generating considerable degrees of\\u000a potential confounding. With respect to pre-natal

George Davey Smith; Sam Leary; Andy Ness; Debbie A. Lawlor

277

Spatial, temporal, and life history assumptions influence consistency of landscape effects on species distributions  

Microsoft Academic Search

Models describing relationships between landscape features and species distribution patterns often display inter-study inconsistencies.\\u000a Identifying factors contributing to these inconsistencies is a vital step in clarifying the ecological importance of landscape\\u000a features and synthesizing an effective knowledge base for use in conservation contexts. We examined the influence of several\\u000a spatial, temporal, and life history assumptions on the outcomes of distribution

Brian G. TaverniaJ; J. Michael Reed

2010-01-01

278

Understanding Influence of Mobile Internet Services on Life Behavior of Mobile Users  

Microsoft Academic Search

We have performed a Web-based survey to analyze a variety of services provided via mobile devices, and we studied how the\\u000a usage of mobile Internet services is influencing the life behavior of mobile users. The survey was targeted to young generation\\u000a users in their 20’s-early 30’s, who are main users of mobile Internet services. Mobile services are categorized into Entertainment,

Sang Min Ko; Yong Gu Ji; Dongsoo Kim

2007-01-01

279

Potential for anthropogenic disturbances to influence evolutionary change in the life history of a threatened salmonid.  

PubMed

Although evolutionary change within most species is thought to occur slowly, recent studies have identified cases where evolutionary change has apparently occurred over a few generations. Anthropogenically altered environments appear particularly open to rapid evolutionary change over comparatively short time scales. Here, we consider a Pacific salmon population that may have experienced life-history evolution, in response to habitat alteration, within a few generations. Historically, juvenile fall Chinook salmon (Oncorhynchus tshawytscha) from the Snake River migrated as subyearlings to the ocean. With changed riverine conditions that resulted from hydropower dam construction, some juveniles now migrate as yearlings, but more interestingly, the yearling migration tactic has made a large contribution to adult returns over the last decade. Optimal life-history models suggest that yearling juvenile migrants currently have a higher fitness than subyearling migrants. Although phenotypic plasticity likely accounts for some of the change in migration tactics, we suggest that evolution also plays a significant role. Evolutionary change prompted by anthropogenic alterations to the environment has general implications for the recovery of endangered species. The case study we present herein illustrates the importance of integrating evolutionary considerations into conservation planning for species at risk. PMID:25567631

Williams, John G; Zabel, Richard W; Waples, Robin S; Hutchings, Jeffrey A; Connor, William P

2008-05-01

280

Potential for anthropogenic disturbances to influence evolutionary change in the life history of a threatened salmonid  

PubMed Central

Although evolutionary change within most species is thought to occur slowly, recent studies have identified cases where evolutionary change has apparently occurred over a few generations. Anthropogenically altered environments appear particularly open to rapid evolutionary change over comparatively short time scales. Here, we consider a Pacific salmon population that may have experienced life-history evolution, in response to habitat alteration, within a few generations. Historically, juvenile fall Chinook salmon (Oncorhynchus tshawytscha) from the Snake River migrated as subyearlings to the ocean. With changed riverine conditions that resulted from hydropower dam construction, some juveniles now migrate as yearlings, but more interestingly, the yearling migration tactic has made a large contribution to adult returns over the last decade. Optimal life-history models suggest that yearling juvenile migrants currently have a higher fitness than subyearling migrants. Although phenotypic plasticity likely accounts for some of the change in migration tactics, we suggest that evolution also plays a significant role. Evolutionary change prompted by anthropogenic alterations to the environment has general implications for the recovery of endangered species. The case study we present herein illustrates the importance of integrating evolutionary considerations into conservation planning for species at risk. PMID:25567631

Williams, John G; Zabel, Richard W; Waples, Robin S; Hutchings, Jeffrey A; Connor, William P

2008-01-01

281

Wetlands in Changed Landscapes: The Influence of Habitat Transformation on the Physico-Chemistry of Temporary Depression Wetlands  

PubMed Central

Temporary wetlands dominate the wet season landscape of temperate, semi-arid and arid regions, yet, other than their direct loss to development and agriculture, little information exists on how remaining wetlands have been altered by anthropogenic conversion of surrounding landscapes. This study investigates relationships between the extent and type of habitat transformation around temporary wetlands and their water column physico-chemical characteristics. A set of 90 isolated depression wetlands (seasonally inundated) occurring on coastal plains of the south-western Cape mediterranean-climate region of South Africa was sampled during the winter/spring wet season of 2007. Wetlands were sampled across habitat transformation gradients according to the areal cover of agriculture, urban development and alien invasive vegetation within 100 and 500 m radii of each wetland edge. We hypothesized that the principal drivers of physico-chemical conditions in these wetlands (e.g. soil properties, basin morphology) are altered by habitat transformation. Multivariate multiple regression analyses (distance-based Redundancy Analysis) indicated significant associations between wetland physico-chemistry and habitat transformation (overall transformation within 100 and 500 m, alien vegetation cover within 100 and 500 m, urban cover within 100 m); although for significant regressions the amount of variation explained was very low (range: ?2 to ?5.5%), relative to that explained by purely spatio-temporal factors (range: ?35.5 to ?43%). The nature of the relationships between each type of transformation in the landscape and individual physico-chemical variables in wetlands were further explored with univariate multiple regressions. Results suggest that conservation of relatively narrow (?100 m) buffer strips around temporary wetlands is likely to be effective in the maintenance of natural conditions in terms of physico-chemical water quality. PMID:24533161

Bird, Matthew S.; Day, Jenny A.

2014-01-01

282

Edge geometry influences patch-level habitat use by an edge specialist in south-eastern Australia  

Microsoft Academic Search

We investigated patterns in habitat use by the noisy miner (Manorina melanocephala) along farmland-woodland edges of large patches of remnant vegetation (>300 ha) in the highly fragmented box-ironbark woodlands\\u000a and forests of central Victoria, Australia. Noisy miners exclude small birds from their territories, and are considered a\\u000a significant threat to woodland bird communities in the study region. Seventeen different characteristics of

Rick S. Taylor; Joanne M. Oldland; Michael F. Clarke

2008-01-01

283

GHOSTS OF HABITATS PAST: CONTRIBUTION OF LANDSCAPE CHANGE TO CURRENT HABITATS USED BY SHRUBLAND BIRDS  

Microsoft Academic Search

Models of habitat associations for species often are developed with an im- plicit assumption that habitats are static, even though recent disturbance may have altered the landscape. We tested our hypothesis that trajectory and magnitude of habitat change influenced observed distribution and abundance of passerine birds breeding in shrubsteppe habitats of southwestern Idaho. Birds in this region live in dynamic

STEVEN T. K NICK; JOHN T. R OTENBERRY

2000-01-01

284

Behavioral mechanisms of habitat segregation between sympatric species of Microtus : Habitat preference and interspecific dominance  

Microsoft Academic Search

Two species of microtine rodents are sympatric in eastern Washington, but they are segregated by habitat. Microtus montanus is found in the grass, and M. longicaudus occupies the shrub habitat. This investigation evaluated behavioral mechanisms controlling the distribution and asked the questions: (1) Are voles of either or both species occupying a preferred habitat? (2) Is a habitat preference influenced

Jan A. Randall

1978-01-01

285

The Influence of Diurnal Temperature Variation on Degree-Day Accumulation and Insect Life History  

PubMed Central

Ectotherms, such as insects, experience non-constant temperatures in nature. Daily mean temperatures can be derived from the daily maximum and minimum temperatures. However, the converse is not true and environments with the same mean temperature can exhibit very different diurnal temperate ranges. Here we apply a degree-day model for development of the grape berry moth (Paralobesia viteana, a significant vineyard pest in the northeastern USA) to investigate how different diurnal temperature range conditions can influence degree-day accumulation and, hence, insect life history. We first consider changes in diurnal temperature range independent of changes in mean temperatures. We then investigate grape berry moth life history under potential climate change conditions, increasing mean temperature via variable patterns of change to diurnal temperature range. We predict that diurnal temperature range change can substantially alter insect life history. Altering diurnal temperature range independent of the mean temperature can affect development rate and voltinism, with the magnitude of the effects dependent on whether changes occur to the daily minimum temperature (Tmin), daily maximum temperature (Tmax), or both. Allowing for an increase in mean temperature produces more marked effects on life history but, again, the patterns and magnitude depend on the nature of the change to diurnal temperature range together with the starting conditions in the local environment. The study highlights the importance of characterizing the influence of diurnal temperature range in addition to mean temperature alone. PMID:25790195

Chen, Shi; Fleischer, Shelby J.; Saunders, Michael C.; Thomas, Matthew B.

2015-01-01

286

Influences of early habitat use on the migratory plasticity and demography of Japanese eels in central Japan  

NASA Astrophysics Data System (ADS)

The timing of their entry into freshwater was found using otolith Sr:Ca ratios of 172 silver eels from the Hamana Lake system of central Japan, to be an important factor affecting whether or not Japanese eels (Anguilla japonica) later leave freshwater during their early growth phase. A high degree of phenotypic plasticity in migration and habitat use during their growth phase was found, with eels living in, or moving between, both freshwater and estuarine water. Of the 59% of the total eels that entered freshwater, 23% of those moved back to the brackish water lake within about 2 years. A higher proportion of river residents were females, but there were no significant differences in size, age, or growth at the start of their spawning migration among the different migratory types. None of the earliest eels to move into freshwater appeared to move back into the lake, and none of the eels that experienced the highest salinities at the time of recruitment appeared to enter freshwater. However, a large proportion of eels that arrived in freshwater later returned to the lake. This suggested that timing of arrival into freshwater may be an important factor determining which eels entering freshwater will remain there and which will make habitat shifts back to estuarine habitat.

Yokouchi, Kazuki; Fukuda, Nobuto; Miller, Michael J.; Aoyama, Jun; Daverat, Françoise; Tsukamoto, Katsumi

2012-07-01

287

Habitat Fragmentation and Ecological Traits Influence the Prevalence of Avian Blood Parasites in a Tropical Rainforest Landscape  

PubMed Central

In the tropical rainforests of northern Australia, we investigated the effects of habitat fragmentation and ecological parameters on the prevalence of blood-borne parasites (Plasmodium and Haemoproteus) in bird communities. Using mist-nets on forest edges and interiors, we sampled bird communities across six study sites: 3 large fragments (20–85 ha) and 3 continuous-forest sites. From 335 mist-net captures, we recorded 28 bird species and screened 299 bird samples with PCR to amplify and detect target DNA. Of the 28 bird species sampled, 19 were infected with Plasmodium and/or Haemoproteus and 9 species were without infection. Over one third of screened birds (99 individuals) were positive for Haemoproteus and/or Plasmodium. In forest fragments, bird capture rates were significantly higher than in continuous forests, but bird species richness did not differ. Unexpectedly, we found that the prevalence of the dominant haemosporidian infection, Haemoproteus, was significantly higher in continuous forest than in habitat fragments. Further, we found that ecological traits such as diet, foraging height, habitat specialisation and distributional ranges were significantly associated with blood-borne infections. PMID:24124541

Laurance, Susan G. W.; Jones, Dean; Westcott, David; Mckeown, Adam; Harrington, Graham; Hilbert, David W.

2013-01-01

288

The relative effects of habitat loss, fragmentation, and degradation on population extinction  

EPA Science Inventory

The most prominent conservation concerns are typically habitat loss and habitat fragmentation. The role of habitat degradation has received comparatively little attention. But research has shown that the quality of habitat patches can significantly influence wildlife population d...

289

The Influence of Free Space Environment in the Mission Life Cycle: Material Selection  

NASA Technical Reports Server (NTRS)

The natural space environment has a great influence on the ability of space systems to perform according to mission design specification. Understanding the natural space environment and its influence on space system performance is critical to the concept formulation, design, development, and operation of space systems. Compatibility with the natural space environment is a primary factor in determining the functional lifetime of the space system. Space systems being designed and developed today are growing in complexity. In many instances, the increased complexity also increases its sensitivity to space environmental effects. Sensitivities to the natural space environment can be tempered through appropriate design measures, material selection, ground processing, mitigation strategies, and/or the acceptance of known risks. The design engineer must understand the effects of the natural space environment on the space system and its components. This paper will discuss the influence of the natural space environment in the mission life cycle with a specific focus on the role of material selection.

Edwards, David L.; Burns, Howard D.; de Groh, Kim K.

2014-01-01

290

Early life influences on the development of chronic obstructive pulmonary disease.  

PubMed

There is increasing evidence that chronic obstructive pulmonary disease (COPD) is not simply a disease of old age that is largely restricted to heavy smokers, but may be associated with insults to the developing lung during foetal life and the first few years of postnatal life, when lung growth and development are rapid. A better understanding of the long-term effects of early life factors, such as intrauterine growth restriction, prenatal and postnatal exposure to tobacco smoke and other pollutants, preterm delivery and childhood respiratory illnesses, on the subsequent development of chronic respiratory disease is imperative if appropriate preventive and management strategies to reduce the burden of COPD are to be developed. The extent to which insults to the developing lung are associated with increased risk of COPD in later life depends on the underlying cause, timing and severity of such derangements. Suboptimal conditions in utero result in aberrations of lung development such that affected individuals are born with reduced lung function, which tends to remain diminished throughout life, thereby increasing the risk both of wheezing disorders during childhood and subsequent COPD in genetically susceptible individuals. If the current trend towards the ever-increasing incidence of COPD is to be reversed, it is essential to minimize risks to the developing lung by improvements in antenatal and neonatal care, and to reduce prenatal and postnatal exposures to environmental pollutants, including passive tobacco smoke. Furthermore, adult physicians need to recognize that lung disease is potentially associated with early life insults and provide better education regarding diet, exercise and avoidance of smoking to preserve precious reserves of lung function in susceptible adults. This review focuses on factors that adversely influence lung development in utero and during the first 5 years of life, thereby predisposing to subsequent COPD. PMID:23439689

Stocks, Janet; Sonnappa, Samatha

2013-06-01

291

Endogenous opioid system influences depressive reactions to socially painful targeted rejection life events.  

PubMed

Although exposure to a recent major life event is one of the strongest known risk factors for depression, many people who experience such stress do not become depressed. Moreover, the biological mechanisms underlying differential emotional reactions to social adversity remain largely unknown. To investigate this issue, we examined whether the endogenous opioid system, which is known to influence sensitivity to physical pain, is also implicated in differential risk for depression following socially painful targeted rejection versus non-targeted rejection life events. Adolescents (n=420) enrolled in a large longitudinal birth cohort study had their recent stress exposure and current mental health status assessed using self-report and interview-based methods. Participants were also genotyped for the A118G polymorphism in the ?-opioid receptor gene (OPRM1, rs1799971), which has been found to influence neural and psychological responses to rejection, likely by affecting opioid receptor expression and signaling efficiency. As hypothesized, G allele carriers, who are known to exhibit less opioid receptor expression and signaling efficiency, were more severely depressed and twice as likely to meet criteria for major depressive disorder following a recent targeted rejection major life event (e.g., being broken up with, getting fired) relative to A/A homozygotes who experienced such stress. However, A118G genotype did not moderate the effects of other similarly severe major life events on depression. These data thus elucidate a biological pathway that may specifically influence sensitivity to social pain and rejection, which in turn has implications for understanding differential risk for depression and several other social stress-related disorders. PMID:25086307

Slavich, George M; Tartter, Molly A; Brennan, Patricia A; Hammen, Constance

2014-11-01

292

Exploring Habitats!  

NSDL National Science Digital Library

If you could live anywhere in the world, where would you live? Do you think you could survive anywhere in the world or in any habitat? What types of adaptations might help you survive in your dream habitat? Many places seem great to visit, but you won't know if it's the place for you unless you know the characteristics of the habitat. This lesson will encourage your students to research habitats and adaptations that allow plants and animals to survive in their natural environments.

Vanessa Brewster

2012-06-14

293

Habitat Mapping  

NSDL National Science Digital Library

How do we study what we cannot see or touch? Students learn about technologies used for underwater mapping, such as benthic habitat images produced by GIS. They participate in a class discussion on why habitat mapping is useful and how current technology works to make bathymetry mapping possible. Through inquiry-based questions, students brainstorm about the importance of bathymetry mapping to help us explore and map the seafloor, marine habitats and the water column. They examine collected data and draw conclusions. Students learn how remote sensing and underwater vehicles designed by engineers give scientists more data to be able to better map marine habitats.

Engineering K-PhD Program,

294

Dietary protein influences the life-history characteristics across generations in the African striped mouse Rhabdomys.  

PubMed

The level of dietary protein determines the onset of reproduction, affects offspring growth and maturation, and hence influences life-history traits and fitness. However, to date, the long-term life-history consequences of protein deficiency are not well understood. We studied the transgenerational effects of different levels of dietary protein on the life-history and level of maternal behavior of the striped mouse Rhabdomys dilectus chakae in captivity. Breeding pairs were assigned to three treatments based on the percentage of dietary protein: baseline (BP; 19%); high protein (HP; 24%); and low protein (LP; 10%). Reproductive output and offspring ontogeny was diminished in the LP treatment compared to the other treatments. Transgenerational effects were studied by breeding F2 females raised on the LP or HP diets on the same (HP-HP, LP-LP) or altered diets (HP-LP, LP-HP). The LP-LP treatment had no reproductive success, while reproductive capacity in the remaining treatments was determined mainly by the diet of mothers at breeding. Pups from protein-restricted females (LP, HP-LP) showed post-weaning compensatory growth. Timing of sexual maturity was age-dependent in female and mass-dependent in male offspring. Females fed low protein diets during breeding (LP, HP-LP) displayed lower levels of maternal behavior than females from the other treatments. This study demonstrates that the level of dietary protein influences the life-history of R. d. chakae in predictable ways. The taxon responds to changes in dietary protein at breeding, largely regardless of its nutrition during rearing. Such phenotypic flexibility in life-history parameters allows Rhabdomys to adaptively respond to unpredictable environmental changes. J. Exp. Zool. 323A: 97-108, 2015. © 2015 Wiley Periodicals, Inc. PMID:25589162

Nel, Kerith; Rimbach, Rebecca; Pillay, Neville

2015-02-01

295

Intercohort density dependence drives brown trout habitat selection  

NASA Astrophysics Data System (ADS)

Habitat selection can be viewed as an emergent property of the quality and availability of habitat but also of the number of individuals and the way they compete for its use. Consequently, habitat selection can change across years due to fluctuating resources or to changes in population numbers. However, habitat selection predictive models often do not account for ecological dynamics, especially density dependent processes. In stage-structured population, the strength of density dependent interactions between individuals of different age classes can exert a profound influence on population trajectories and evolutionary processes. In this study, we aimed to assess the effects of fluctuating densities of both older and younger competing life stages on the habitat selection patterns (described as univariate and multivariate resource selection functions) of young-of-the-year, juvenile and adult brown trout Salmo trutta. We observed all age classes were selective in habitat choice but changed their selection patterns across years consistently with variations in the densities of older but not of younger age classes. Trout of an age increased selectivity for positions highly selected by older individuals when their density decreased, but this pattern did not hold when the density of younger age classes varied. It suggests that younger individuals are dominated by older ones but can expand their range of selected habitats when density of competitors decreases, while older trout do not seem to consider the density of younger individuals when distributing themselves even though they can negatively affect their final performance. Since these results may entail critical implications for conservation and management practices based on habitat selection models, further research should involve a wider range of river typologies and/or longer time frames to fully understand the patterns of and the mechanisms underlying the operation of density dependence on brown trout habitat selection.

Ayllón, Daniel; Nicola, Graciela G.; Parra, Irene; Elvira, Benigno; Almodóvar, Ana

2013-01-01

296

Foraging habits in a generalist predator: sex and age influence habitat selection and resource use among bottlenose dolphins (Tursiops truncatus)  

USGS Publications Warehouse

This study examines resource use (diet, habitat use, and trophic level) within and among demographic groups (males, females, and juveniles) of bottlenose dolphins (Tursiops truncatus). We analyzed the ?13C and ?15N values of 15 prey species constituting 84% of the species found in stomach contents. We used these data to establish a trophic enrichment factor (TEF) to inform dietary analysis using a Bayesian isotope mixing model. We document a TEF of 0‰ and 2.0‰ for ?13C and ?15N, respectively. The dietary results showed that all demographic groups relied heavily on low trophic level seagrass-associated prey. Bayesian standard ellipse areas (SEAb) were calculated to assess diversity in resource use. The SEAb of females was nearly four times larger than that of males indicating varied resource use, likely a consequence of small home ranges and habitat specialization. Juveniles possessed an intermediate SEAb, generally feeding at a lower trophic level compared to females, potentially an effect of natal philopatry and immature foraging skills. The small SEAb of males reflects a high degree of specialization on seagrass associated prey. Patterns in resource use by the demographic groups are likely linked to differences in the relative importance of social and ecological factors.

Sam Rossman; McCabe, Elizabeth Berens; Nelio B. Barros; Hasand Gandhi; Peggy H. Ostrom; Stricker, Craig A.; Randall S. Wells

2015-01-01

297

Habitat Selection in a Rocky Landscape: Experimentally Decoupling the Influence of Retreat Site Attributes from That of Landscape Features  

PubMed Central

Organisms selecting retreat sites may evaluate not only the quality of the specific shelter, but also the proximity of that site to resources in the surrounding area. Distinguishing between habitat selection at these two spatial scales is complicated by co-variation among microhabitat factors (i.e., the attributes of individual retreat sites often correlate with their proximity to landscape features). Disentangling this co-variation may facilitate the restoration or conservation of threatened systems. To experimentally examine the role of landscape attributes in determining retreat-site quality for saxicolous ectotherms, we deployed 198 identical artificial rocks in open (sun-exposed) sites on sandstone outcrops in southeastern Australia, and recorded faunal usage of those retreat sites over the next 29 months. Several landscape-scale attributes were associated with occupancy of experimental rocks, but different features were important for different species. For example, endangered broad-headed snakes (Hoplocephalus bungaroides) preferred retreat sites close to cliff edges, flat rock spiders (Hemicloea major) preferred small outcrops, and velvet geckos (Oedura lesueurii) preferred rocks close to the cliff edge with higher-than-average sun exposure. Standardized retreat sites can provide robust experimental data on the effects of landscape-scale attributes on retreat site selection, revealing interspecific divergences among sympatric taxa that use similar habitats. PMID:22701592

Croak, Benjamin M.; Pike, David A.; Webb, Jonathan K.; Shine, Richard

2012-01-01

298

Ecology of Neoschongastia americana (Hirst): laboratory life cycle, developmental period in the field and influence of selected external factors.  

E-print Network

ECOLOGY OF NEOSCHONGASTIA AMERICANA (HIRST): LABORATORY LIFE CYCLE, DEVELOPMENTAL PERIOD IN THE FIELD AND INFLUENCE OF SELECTED EXTERNAL FACTORS A Thesis by JERRY REAL CUNNINGHAM Submitted to the Graduate College of Texas A&? University... in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 19/4 Major Subject: Entomology ECOLOGY OF NEOSCHONGASTIA AMERICANA (HIRST): LABORATORY LIFE CYCLE, DEVELOPMENTAL PERIOD IN THE FIELD AND INFLUENCE OF SELECTED EXTERNAL...

Cunningham, Jerry Real

1974-01-01

299

Environmental contingency in life history strategies: the influence of mortality and socioeconomic status on reproductive timing.  

PubMed

Why do some people have children early, whereas others delay reproduction? By considering the trade-offs between using one's resources for reproduction versus other tasks, the evolutionary framework of life history theory predicts that reproductive timing should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced the desire to have children sooner rather than later. The effects of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals growing up relatively poor, mortality cues produced a desire to reproduce sooner--to want children now, even at the cost of furthering one's education or career. Conversely, for individuals growing up relatively wealthy, mortality cues produced a desire to delay reproduction--to further one's education or career before starting a family. Overall, mortality cues appear to shift individuals into different life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors can influence fertility and family size. PMID:20873933

Griskevicius, Vladas; Delton, Andrew W; Robertson, Theresa E; Tybur, Joshua M

2011-02-01

300

The indirect effects of eutrophication on habitat choice and survival of fish larvae in the Baltic Sea  

Microsoft Academic Search

The structure of the habitat is usually crucial for growth and survival of young life stages. Presently, some nursery areas\\u000a of fish larvae are changing due to eutrophication, e.g. due to enhanced growth of ephemeral filamentous algae at the expense\\u000a of perennial species. We studied the influence of two habitats, one with filamentous algae (Cladophora glomerata) and the other with

Jonna Engström-Öst; Emmi Immonen; Ulrika Candolin; Johanna Mattila

2007-01-01

301

Habitat of In Vivo Transformation Influences the Levels of Free Radical Scavengers in Clinostomum complanatum: Implications for Free Radical Scavenger Based Vaccines against Trematode Infections  

PubMed Central

Background Since free radical scavengers of parasite origin like glutathione-S-transferase and superoxide dismutase are being explored as prospective vaccine targets, availability of these molecules within the parasite infecting different hosts as well as different sites of infection is of considerable importance. Using Clinostomum complanatum, as a model helminth parasite, we analysed the effects of habitat of in vivo transformation on free radical scavengers of this trematode parasite. Methods Using three different animal models for in vivo transformation and markedly different sites of infection, progenetic metacercaria of C. complanatum were transformed to adult ovigerous worms. Whole worm homogenates were used to estimate the levels of lipid peroxidation, a marker of oxidative stress and free radical scavengers. Results Site of in vivo transformation was found to drastically affect the levels of free radical scavengers in this model trematode parasite. It was observed that oxygen availability at the site of infection probably influences levels of free radical scavengers in trematode parasites. Conclusion This is the first report showing that habitat of in vivo transformation affects levels of free radical scavengers in trematode parasites. Since free radical scavengers are prospective vaccine targets and parasite infection at ectopic sites is common, we propose that infections at different sites, may respond differently to free radical scavenger based vaccines. PMID:24759940

Ahmad, Irshad; Ahmad, Masood

2014-01-01

302

Explaining variance of avian malaria infection in the wild: the importance of host density, habitat, individual life-history and oxidative stress  

PubMed Central

Background Avian malaria (Plasmodium sp.) is globally widespread, but considerable variation exists in infection (presence/absence) patterns at small spatial scales. This variation can be driven by variation in ecology, demography, and phenotypic characters, in particular those that influence the host’s resistance. Generation of reactive oxygen species (ROS) is one of the host’s initial immune responses to combat parasitic invasion. However, long-term ROS exposure can harm the host and the redox response therefore needs to be adjusted according to infection stage and host phenotype. Here we use experimental and correlational approaches to assess the relative importance of host density, habitat composition, individual level variation and redox physiology for Plasmodium infection in a wild population of great tits, Parus major. Results We found that 36% of the great tit population was infected with Plasmodium (22% P. relictum and 15% P. circumflexum prevalence) and that patterns of infection were Plasmodium species-specific. First, the infection of P. circumflexum was significantly higher in areas with experimental increased host density, whereas variation in P. relictum infection was mainly attributed to age, sex and reproduction. Second, great tit antioxidant responses – total and oxidizied glutathione - showed age- , sex- and Plasmodium species-specific patterns between infected and uninfected individuals, but reactive oxygen metabolites (ROM) showed only a weak explanatory power for patterns of P. relictum infection. Instead ROM significantly increased with Plasmodium parasitaemia. Conclusions These results identify some key factors that influence Plasmodium infection in wild birds, and provide a potential explanation for the underlying physiological basis of recently documented negative effects of chronic avian malaria on survival and reproductive success. PMID:23565726

2013-01-01

303

[The influences of interaction during online gaming on sociability and aggression in real life].  

PubMed

This study examined the influences of online gaming on sociability and aggression in real life. It was hypothesized that the effects of online gaming would differ depending on the interaction style of the online-gamers. Online-gamers in Japan (n = 1 477) were asked to respond to questionnaires that measured interaction style during online gaming, the effects of sociability and aggression, as well as social and individual orientation in real life. Factor analysis of the scores for interaction style extracted five factors. Covariance structure analysis indicated that sociable interactions such as "Broadening relations" and "Feeling of belonging" promoted sociability in real life. In addition, "Release from daily hassles" promoted sociability and decreased aggression. In contrast, non-sociable and aggressive interactions decreased sociability and increased aggression. The results also suggested that a social orientation in real life promoted sociable interactions during game playing, while an individual orientation promoted non-sociable and aggressive interactions. These results supported the hypotheses and suggested that online gaming resulted in positive outcomes for those who are socially, but negative outcomes for those who are not. PMID:20235474

Fuji, Kei; Yoshida, Fujio

2010-02-01

304

The Teacher I Wish to Be: Exploring the Influence of Life Histories on Student Teacher Idealised Identities  

ERIC Educational Resources Information Center

This paper examines the influence of life histories and apprenticeship of observation on the formation of student teachers' idealised identities. The life histories of 15 student teachers are decoded. Through eliciting from the student teachers the teacher they wish to be, the paper focuses on the interplay between the personal histories and ideal…

Furlong, Catherine

2013-01-01

305

Habitat automation  

NASA Technical Reports Server (NTRS)

A habitat, on either the surface of the Moon or Mars, will be designed and built with the proven technologies of that day. These technologies will be mature and readily available to the habitat designer. We believe an acceleration of the normal pace of automation would allow a habitat to be safer and more easily maintained than would be the case otherwise. This document examines the operation of a habitat and describes elements of that operation which may benefit from an increased use of automation. Research topics within the automation realm are then defined and discussed with respect to the role they can have in the design of the habitat. Problems associated with the integration of advanced technologies into real-world projects at NASA are also addressed.

Swab, Rodney E.

1992-01-01

306

Habitat Suitability Index Models: Black Crappie  

USGS Publications Warehouse

Characteristics and habitat requirements of the black crappie (Pomoxis nigromaculatus) are described in a review of Habitat Suitability Index models. This is one in a series of publications to provide information on the habitat requirements of selected fish and wildlife species. Numerous literature sources have been consulted in an effort to consolidate scientific data on species-habitat relationships. These data have subsequently been synthesized into explicit Habitat Suitability Index (HSI) models. The models are based on suitability indices indicating habitat preferences. Indices have been formulated for variables found to affect the life cycle and survival of each species. Habitat Suitability Index (HSI) models are designed to provide information for use in impact assessment and habitat management activities. The HSI technique is a corollary to the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures.

Edwards, Elizabeth A.; Krieger, Douglas A.; Bacteller, Mary; Maughan, O. Eugene

1982-01-01

307

Habitat fragmentation and evolutionary ecology  

E-print Network

. Habitat fragmentation can be viewed of as a landscape-scale process involving two co-occurring components (Altizer et al. 2003). Another example of the evolutionary impact of human activity is the influence

Merckx, Thomas

308

Quality of life and its influencing factors among medical professionals in China  

Microsoft Academic Search

Purpose  The present study is to evaluate quality of life (QOL) among Chinese medical professionals and explore its main influencing\\u000a factors.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A total of 2,721 medical professionals were selected from two provinces by using stratified cluster sampling method. The Chinese\\u000a version of Short Form-36 Health Survey (SF-36) was used to measure QOL; Occupation Stress Inventory-Revised Edition (OSI-R)\\u000a was used for occupational

Siying Wu; Wei Zhu; Huangyuan Li; Ignatius Tak-Sun Yu; Sihao Lin; Xiaorong Wang; Shujuan Yang

2010-01-01

309

Influence of local habitat features on disease avoidance by Caribbean spiny lobsters in a casita-enhanced bay.  

PubMed

In Bahía de la Ascensión, Mexico, 'casitas' (large artificial shelters) are extensively used to harvest Caribbean spiny lobsters Panulirus argus. After the discovery of a pathogenic virus, Panulirus argus virus 1 (PaV1), in these lobsters, laboratory experiments revealed that PaV1 could be transmitted by contact and through water, and that lobsters avoided shelters harboring diseased conspecifics. To examine these issues in the context of casitas, which typically harbor multiple lobsters of all sizes, we examined the distribution and aggregation patterns of lobsters in the absence/presence of diseased conspecifics (i.e. visibly infected with PaV1) in 531 casitas distributed over 3 bay zones, 1 poorly vegetated ('Vigía Chico', average depth: 1.5 m) and 2 more extensively vegetated ('Punta Allen': 2.5 m; 'Los Cayos': 2.4 m). All zones had relatively high indices of predation risk. Using several statistical approaches, we found that distribution parameters of lobsters were generally not affected by the presence of diseased conspecifics in casitas. Interestingly, however, in the shallower and less vegetated zone (Vigía Chico), individual casitas harbored more lobsters and lobsters were actually more crowded in casitas containing diseased conspecifics, yet disease prevalence was the lowest in lobsters of all sizes. These results suggest that (1) investment in disease avoidance by lobsters is partially modulated by local habitat features, (2) contact transmission rates of PaV1 may be lower in nature than in the laboratory, and (3) water-borne transmission rates may be lower in shallow, poorly vegetated habitats more exposed to solar ultraviolet radiation, which can damage viral particles. PMID:23186701

Briones-Fourzán, Patricia; Candia-Zulbarán, Rebeca I; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Huchin-Mian, Juan P; Lozano-Álvarez, Enrique

2012-08-27

310

The Influence of Life History Milestones and Association Networks on Crop-Raiding Behavior in Male African  

E-print Network

The Influence of Life History Milestones and Association Networks on Crop-Raiding Behavior in Male, Nairobi, Kenya Abstract Factors that influence learning and the spread of behavior in wild animal conservation. In populations of wildlife species that come into conflict with humans by raiding cultivated

Alberts, Susan C

311

Factors influencing the quality of life of Moroccan patients with juvenile idiopathic arthritis.  

PubMed

The aim of our study is to investigate the factors influencing the quality of life, assessed by the Pediatric Quality of Life Inventory 4.0 (PedsQL4) Generic Score Scales, in Moroccan patients with juvenile idiopathic arthritis. This is a cross-sectional study conducted between January and June 2012, covering children with juvenile idiopathic arthritis (JIA) seen at the consultations of El Ayachi Hospital and Children's Hospital of the University Hospital of Rabat. Quality of life is assessed by the PedsQL4 which is a questionnaire composed of 23 items, completed by the child and the parent; the response to each item ranges from 0 to 100, so that higher scores indicate a better quality of life. The functional impact is assessed by the Childhood Health Assessment Questionnaire (CHAQ), and the disease activity by the number of tender and swollen joints, visual analogue scale (VAS) activity, erythrocyte sedimentation rate (ESR), and C-reactive protein. Forty-seven patients are included; the average age of the patients is 11?±?3.35 years, and 40.4 % are females, with a median disease duration of 4 (2; 6) years. The oligoarticular form presents 26.7 %, the systemic form 24.4 %, and the enthesic form 22.2 %. The median of PedsQL4 is 80.43 (63.19; 92.93), and the median of the CHAQ is 0 (0; 1). Our study shows that some clinical and biological characteristics have significant effects on PedsQL by both parent and child reports. This study suggests that the achievement of the quality of life of our patients with JIA depends on the disease activity measured by swollen joints, the number of awakenings, parent VAS, physician VAS, patient VAS, and the ESR. PMID:24445385

Ezzahri, M; Amine, B; Rostom, S; Badri, D; Mawani, N; Gueddari, S; Shyen, S; Wabi, M; Moussa, F; Abouqal, R; Chkirate, B; Hajjaj-Hassouni, N

2014-11-01

312

Walking in simulated Martian gravity: influence of the portable life support system's design on dynamic stability.  

PubMed

With human exploration of the moon and Mars on the horizon, research considerations for space suit redesign have surfaced. The portable life support system (PLSS) used in conjunction with the space suit during the Apollo missions may have influenced the dynamic balance of the gait pattern. This investigation explored potential issues with the PLSS design that may arise during the Mars exploration. A better understanding of how the location of the PLSS load influences the dynamic stability of the gait pattern may provide insight, such that space missions may have more productive missions with a smaller risk of injury and damaging equipment while falling. We explored the influence the PLSS load position had on the dynamic stability of the walking pattern. While walking, participants wore a device built to simulate possible PLSS load configurations. Floquet and Lyapunov analysis techniques were used to quantify the dynamic stability of the gait pattern. The dynamic stability of the gait pattern was influenced by the position of load. PLSS loads that are placed high and forward on the torso resulted in less dynamically stable walking patterns than loads placed evenly and low on the torso. Furthermore, the kinematic results demonstrated that all joints of the lower extremity may be important for adjusting to different load placements and maintaining dynamic stability. Space scientists and engineers may want to consider PLSS designs that distribute loads evenly and low, and space suit designs that will not limit the sagittal plane range of motion at the lower extremity joints. PMID:19725694

Scott-Pandorf, Melissa M; O'Connor, Daniel P; Layne, Charles S; Josi?, Kresimir; Kurz, Max J

2009-09-01

313

WILDLIFE HABITAT RELATIONS AND HABITAT FRAGMENTATION  

E-print Network

WILDLIFE HABITAT RELATIONS AND HABITAT FRAGMENTATION IV #12;#12;353USDA Forest Service Gen. Tech. Rep. PSW-GTR-160. 1997. Section Overview Wildlife Habitat Relations and Habitat Fragmentation section on wildlife habitat relations and habitat fragmentation in hardwood rangelands from this symposium

Standiford, Richard B.

314

Modeling the influence of genetic and environmental variation on the expression of plant life cycles across landscapes.  

PubMed

Organisms develop through multiple life stages that differ in environmental tolerances. The seasonal timing, or phenology, of life-stage transitions determines the environmental conditions to which each life stage is exposed and the length of time required to complete a generation. Both environmental and genetic factors contribute to phenological variation, yet predicting their combined effect on life cycles across a geographic range remains a challenge. We linked submodels of the plasticity of individual life stages to create an integrated model that predicts life-cycle phenology in complex environments. We parameterized the model for Arabidopsis thaliana and simulated life cycles in four locations. We compared multiple "genotypes" by varying two parameters associated with natural genetic variation in phenology: seed dormancy and floral repression. The model predicted variation in life cycles across locations that qualitatively matches observed natural phenology. Seed dormancy had larger effects on life-cycle length than floral repression, and results suggest that a genetic cline in dormancy maintains a life-cycle length of 1 year across the geographic range of this species. By integrating across life stages, this approach demonstrates how genetic variation in one transition can influence subsequent transitions and the geographic distribution of life cycles more generally. PMID:25616140

Burghardt, Liana T; Metcalf, C Jessica E; Wilczek, Amity M; Schmitt, Johanna; Donohue, Kathleen

2015-02-01

315

Estimating the influence of life satisfaction and positive affect on later income using sibling fixed effects.  

PubMed

The question of whether there is a connection between income and psychological well-being is a long-studied issue across the social, psychological, and behavioral sciences. Much research has found that richer people tend to be happier. However, relatively little attention has been paid to whether happier individuals perform better financially in the first place. This possibility of reverse causality is arguably understudied. Using data from a large US representative panel, we show that adolescents and young adults who report higher life satisfaction or positive affect grow up to earn significantly higher levels of income later in life. We focus on earnings approximately one decade after the person's well-being is measured; we exploit the availability of sibling clusters to introduce family fixed effects; we account for the human capacity to imagine later socioeconomic outcomes and to anticipate the resulting feelings in current well-being. The study's results are robust to the inclusion of controls such as education, intelligence quotient, physical health, height, self-esteem, and later happiness. We consider how psychological well-being may influence income. Sobel-Goodman mediation tests reveal direct and indirect effects that carry the influence from happiness to income. Significant mediating pathways include a higher probability of obtaining a college degree, getting hired and promoted, having higher degrees of optimism and extraversion, and less neuroticism. PMID:23169627

De Neve, Jan-Emmanuel; Oswald, Andrew J

2012-12-01

316

Influence of temperature on the life-cycle of Globodera spp.  

PubMed

The potato cyst nematodes (PCN) G. rostochiensis (Woll.) and G. pallida (Stone) are the most economically important pests of potato (Solanum tuberosum L.) in the UK and are widespread in ware potato growing regions in Europe. The new EU directive 2007/33/EC which came into effect July 1, 2010 aims to control their spread and limit further increases in populations. We are investigating the role of temperature in the life cycle of PCN to assess how this effects population multiplication in relation to managing PCN. Hatching and nematode development are stages in the life cycle that are affected by temperature and thus are important life stages that can be examined to determine the impact of temperature on the length of time required for one generation to be completed and the potential for final populations to increase on different potato genetic backgrounds. In some conditions a partial or complete second generation has also been observed within the growing season. Females have been observed on the surface of tubers and "pecking" skin damage can occur which may be a result of a second generation. We are investigating the influence of temperature on the potential for a second generation or the induction of diapause. PMID:22696942

Blok, V; Kaczmarek, A; Palomares-Rius, J E

2011-01-01

317

Influence of Weight Gain Rate on Early Life Nutritional Status and Body Composition of Children  

PubMed Central

Objective. To evaluate the influence of the weight gain rate at 4–6 months on nutritional status and body composition in children between 4 and 7 years of age. Methods. Retrospective cohort study, sample of 257 children. Data collection was performed in two stages, with the first relating to retrospective data of weight gain from birth to the first 4–6 months of life in the patient records. Measurements of weight, height, waist circumference, and body composition in children between ages 4 and 7 years were obtained. Nutritional status was assessed by the BMI/age. Control variables, such as pregnancy, breastfeeding, lifestyle, and sociodemographics, were studied. Descriptive analysis and multiple linear regression were performed. Results. In the nutritional status assessment, the prevalence of overweight observed was 24.9%. After adjusting for control variables, it was found that the increase of the WGR at 4–6 months of age explained the occurrence of higher BMI/age, percentage of total body fat, body fat percentage in the android region, and waist circumference in children between 4 and 7 years of age. Conclusion. The increase of the WGR in the first months of life can lead to the occurrence of higher values of parameters of nutritional status and body composition in later life. PMID:25538953

Magalhães, Taís Cristina Araújo; Ribeiro, Andréia Queiroz; Priore, Silvia Eloiza; Franceschini, Sylvia do Carmo Castro; Sant'Ana, Luciana Ferreira da Rocha

2014-01-01

318

Influence of physicians' life-stance on attitudes towards end-of-life decisions and actual end-of-life decision-making in six countries  

Microsoft Academic Search

Aim: To examine how physicians’ life stances affect their attitudes to end-of-life decisions and their actual end-of-life decision-making.\\u000aMethods: Practising physicians from various specialties involved in the care of dying patients in Belgium, Denmark, The Netherlands, Sweden, Switzerland and Australia received structured questionnaires on end-of-life care, which included questions about their life stance. Response rates ranged from 53% in Australia

Joachim Cohen; J van Delden; Freddy Mortier; Rurik Lofmark; Michael Norup; Colleen M Cartwright; Karin Faisst; C Canova; J Bilsen

2008-01-01

319

The influence of early exposure to vitamin D for development of diseases later in life  

PubMed Central

Background Vitamin D deficiency is common among otherwise healthy pregnant women and may have consequences for them as well as the early development and long-term health of their children. However, the importance of maternal vitamin D status on offspring health later in life has not been widely studied. The present study includes an in-depth examination of the influence of exposure to vitamin D early in life for development of fractures of the wrist, arm and clavicle; obesity, and type 1 diabetes (T1D) during child- and adulthood. Methods/design The study is based on the fact that in 1961 fortifying margarine with vitamin D became mandatory in Denmark and in 1972 low fat milk fortification was allowed. Apart from determining the influences of exposure prior to conception and during prenatal life, we will examine the importance of vitamin D exposure during specific seasons and trimesters, by comparing disease incidence among individuals born before and after fortification. The Danish National databases assure that there are a sufficient number of individuals to verify any vitamin D effects during different gestation phases. Additionally, a validated method will be used to determine neonatal vitamin D status using stored dried blood spots (DBS) from individuals who developed the aforementioned disease entities as adults and their time and gender-matched controls. Discussion The results of the study will contribute to our current understanding of the significance of supplementation with vitamin D. More specifically, they will enable new research in related fields, including interventional research designed to assess supplementation needs for different subgroups of pregnant women. Also, other health outcomes can subsequently be studied to generate multiple health research opportunities involving vitamin D. Finally, the results of the study will justify the debate of Danish health authorities whether to resume vitamin D supplementation policies. PMID:23714352

2013-01-01

320

Relative influence of local- and landscape-level habitat quality on aquatic plant diversity in shallow open-water wetlands in Alberta’s boreal zone: direct and indirect effects  

Microsoft Academic Search

Reclamation usually involves modification of the local environment to achieve some biotic target, but if the influence of\\u000a Landscape Condition on that target is great, we may fail to meet it despite efforts at the local-level. We sought to determine\\u000a the relative influence of local- and landscape-level habitat on aquatic plant diversity in shallow open-water wetlands. Furthermore,\\u000a we asked whether

Rebecca C. RooneySuzanne; Suzanne E. Bayley

2011-01-01

321

Population history and life history influence the migration rate of female Glanville fritillary butterflies  

Microsoft Academic Search

This study examines the causes of emigration from small fragments of suitable habitat in a species that has a distinct metapopulation structure, frequent turnover of local populations, and substantial migration among local populations and currently unoccupied habitat fragments. We conducted a field experiment in which 727 individuals of the Glanville fritillary butterfly (Melitaea cinxia) originating from four regions were marked

Ilkka Hanski; Casper J. Breuker; Katrin Schops; Rosemary Setchfield; Marko Nieminen

2002-01-01

322

Hyperlink Habitats  

NSDL National Science Digital Library

This activity is designed to help students understand the complexity of nature by utilizing an online illustration of the ways in which various elements of a rainforest ecosystem are interconnected. Students will map the online habitat and create their own hyperlink habitat, either in print or on the Web, for a local ecosystem. When they are finished, they can submit their work to the Discovery Channel School.

323

Structurally complex habitats provided by Acropora palmata influence ecosystem processes on a reef in the Florida Keys National Marine Sanctuary  

NASA Astrophysics Data System (ADS)

The disappearance of Acropora palmata from reefs in the Florida Keys National Marine Sanctuary (FKNMS) represents a significant loss in the amount of structurally complex habitat available for reef-associated species. The consequences of such a widespread loss of complex structure on ecosystem processes are still unclear. We sought to determine whether the disappearance of complex structure has adversely affected grazing and invertebrate predation rates on a shallow reef in the FKNMS. Surprisingly, we found grazing rates and invertebrate predation rates were lower in the structurally complex A. palmata branches than on the topographically simple degraded reefs. We attribute these results to high densities of aggressively territorial damselfish, Stegastes planifrons, living within A. palmata. Our study suggests the presence of agonistic damselfish can cause the realized spatial patterns of ecosystem processes to deviate from the expected patterns. Reef ecologists must therefore carefully consider the assemblage of associate fish communities when assessing how the mortality of A. palmata has affected coral reef ecosystem processes.

Lemoine, N. P.; Valentine, J. F.

2012-09-01

324

Ecological Interactions in Dinosaur Communities: Influences of Small Offspring and Complex Ontogenetic Life Histories  

PubMed Central

Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs’ successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S) distribution of carnivorous dinosaurs (as found in the theropod fossil record), in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora). Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods), in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey exists in mammals larger than 21.5 kg, and it seems a similar minimum prey-size threshold could have affected dinosaurs as well. PMID:24204749

Codron, Daryl; Carbone, Chris; Clauss, Marcus

2013-01-01

325

How Does Chronic Back Pain Influence Quality of Life in Koreans: A Cross-Sectional Study  

PubMed Central

Study Design A cross-sectional study. Purpose To explore the impact of chronic low back pain (CLBP) on individuals' quality of life; to understand current treatment practices and level of satisfaction with treatment in patients with CLBP. Overview of Literature Assessing subjective, patient-reported outcomes such as quality of life is essential to health care research. Methods Influences of the CLBP were analyzed via a questionnaire, which contained the character of CLBP, effect of pain management, Korean version Oswestry Disability Index (K-ODI) and Korean version of 12-item Short Form Health Survey (SF-12v2). Results Of 3,121 subjects who responded, 67.3% had moderate to severe pain; 43.5% presented prolonged CLBP of more than two years; and 32.4% had suffered from sleep disturbance due to pain. 22.8% of the patients were not satisfied with current pain management. The mean K-ODI score was 37.63; and it was positively correlated with the mean pain intensity (r=0.6, p<0.001). The SF-12v2 result was negatively correlated with mean pain intensity (PCS: r=-0.5, p<0.001; MCS: r=-0.4, p<0.001) and also negatively correlated with the K-ODI score (PCS: r=-0.75, p<0.001; MCS: r=-0.5, p<0.001). The conformity between patients and doctors in pain assessment was fair (?=0.2463). Conclusions CLBP negatively affects quality of life. Of total 22.8% of the patients were not satisfied with current pain management. Such needs to be taken more seriously by doctors for improvement of satisfaction and quality of life in patients with CLBP. PMID:24967049

Choi, Yong Soo; Kim, Dong Jun; Lee, Kyu Yeol; Park, Ye Soo; Cho, Kyu Jung; Lee, Jae Hyup; Rhim, Hyou Young

2014-01-01

326

The influence of habitat and environment on smallmouth bass ( Micropterus dolomieu) nest sites and nest success in northern Lake Michigan  

Microsoft Academic Search

Information on smallmouth bass nesting ecology is lacking in northern Lake Michigan, despite available information for other Great Lakes ecosystems. Our objectives were to identify factors that influenced nesting sites and nest success in a smallmouth bass population in northern Lake Michigan. Temperature, substrate firmness, and lake bottom rugosity were measured and related to the number of smallmouth bass nests

Mark A. Kaemingk; Alexander Clem; Tracy L. Galarowicz

2011-01-01

327

Factors influencing health-related quality of life of Asians with anxiety disorders in Singapore.  

PubMed

As little is known about health-related quality of life (HRQoL) in Asians with anxiety disorders, we assessed HRQoL in Singaporeans with anxiety disorders and identified factors influencing their HRQoL. Outpatients with anxiety disorders (n = 119) attending a hospital psychiatric clinic completed the Short Form 36 Health Survey (SF-36), Beck Anxiety Inventory (BAI) and General Health Questionnaire (GHQ-12). SF-36 score reduction from population norms (quantified as the number of standard deviations below the mean) in these subjects was compared with existing data on Singaporeans with various medical conditions and Americans with panic disorder (PD). Factors influencing HRQoL were examined using stepwise multiple linear regression models. SF-36 score reduction in these subjects (0.3-1.4 SD) was greater than that in Singaporeans with systemic lupus erythematosus or thyroid cancer survivors for seven scales but similar to that in Americans with PD (0.5-1.7 SD). BAI and GHQ-12 scores, presence of PD/generalized anxiety disorder, presence of chronic medical conditions, being married or increasing age accounted for 19-61% of the variance in six selected SF-36 scales. In conclusion, it can be said that Singaporeans with anxiety disorders experience clinically important reductions in HRQoL; both clinical and socio-demographic factors influence HRQoL in such subjects. PMID:15085928

Luo, Nan; Fones, Calvin Soon-Leng; Thumboo, Julian; Li, Shu-Chuen

2004-03-01

328

Influence of environmental and prey variables on low tide shorebird habitat use within the Robbins Passage wetlands, Northwest Tasmania  

NASA Astrophysics Data System (ADS)

Shorebirds feed primarily on tidal flats, and their distribution over these flats is influenced by their prey and abiotic factors. These factors act by influencing the distribution and abundance of the prey, or the shorebirds ability to exploit it. The aims of this study were to investigate the low tide foraging distribution of shorebirds at four sites within the Robbins Passage wetlands, and the environmental and invertebrate factors that may influence their distribution. The greatest densities and number of shorebirds were found at Shipwreck Point and East Inlet. The shorebirds within-site distribution was also non-random, with the shorebirds present in greatest densities at the water's edge and low intertidal stratum, although this varied among species. Generally, on a small spatial scale, invertebrate diversity was positively correlated, and seagrass leaf mass was negatively correlated, with shorebird feeding density. On a large spatial scale, invertebrate biomass and seagrass root mass were positively correlated with shorebird feeding density. Invertebrate biomass and seagrass root mass explained 71% of the variance in total shorebird feeding density on the tidal flats. The variation in shorebird feeding density and diversity was therefore partly explained by invertebrate diversity and biomass, as well as the environmental factors seagrass roots and leaf mass and tidal flat area, although the strength of these relationships was influenced by the two different spatial scales of the study. The strength of the relationships between shorebird feeding density and the invertebrate and environmental variables was stronger on a large spatial scale. The presence of seagrass may have influenced shorebird-feeding density by affecting the invertebrate abundance and composition or the shorebirds ability to detect and capture their prey. The area of the tidal flat had opposing effects on the shorebird species. These results can be used to assist in the development of management plans for the Robbins Passage wetlands and the conservation of important shorebird areas.

Spruzen, Fiona L.; Richardson, Alastair M. M.; Woehler, Eric J.

2008-06-01

329

The Influence of Climate Change and Fire on Sediment Transport and Aquatic Habitat: a Case Study of the South Fork of Salmon River Basin, Idaho  

NASA Astrophysics Data System (ADS)

In the western United States, climate change is predicted to increase fire severity and frequency, decrease snowpack, and alter the timing and volume of runoff. Wildfire often increases hillslope erosion rates, which alter the timing, quantity and grain-size distribution of sediment supplied to streams. In addition, extreme flood events may become more frequent with climate change and will impact the channel morphology, grain-size distributions and aquatic habitat. To understand the influence of climatically induced alterations in flow hydrographs and hillslope erosion rates, a one-dimensional bedload transport model is used to calculate sediment and flow routing through the South Fork of the Salmon River. The model includes a channel network with drainage areas between 1.5 to 125 square kilometers. To understand the impact of increased hillslope erosion rates, we varied the amount and grain size distribution of supplied sediment between model runs while holding the flow hydrograph constant (rain vs. snow dominated). We also use data collected from an extreme flood event in June 2010, which was the highest recorded flow on record, as a proxy for the impact of climate change. We measured the grain size distributions, and channel dimensions in seventeen channels before and after this event. These parameters only changed significantly in channels with large sediment inputs from landslides. We also model the following two scenarios: 1) pre-event channel and sediment supply conditions combined with a snowmelt dominated hydrograph and 2) post-event channel and sediment supply conditions combined with the extreme event hydrograph. We compare the predicted channel slopes, grain size distributions, flow hydraulics (e.g. flow velocity, shear stress) and bedload fluxes between each model run and throughout the channel network. Such calculations are used to better understand the impact of sediment supply and flow hydrographs on channel stability, and aquatic habitat suitability (e.g. grain size, flow hydraulics) for a number of threatened and endangered species in Idaho.

Neupane, S.; Yager, E. M.

2010-12-01

330

Influence of oceanic factors on Anguilla anguilla (L.) over the twentieth century in coastal habitats of the Skagerrak, southern Norway.  

PubMed

The European eel (Anguilla anguilla L.) is distributed in coastal and inland habitats all over Europe, but spawns in the Sargasso Sea and is thus affected by both continental and oceanic factors. Since the 1980s a steady decline has been observed in the recruitment of glass eels to freshwater and in total eel landings. The eel is considered as critically endangered on the International Union for the Conservation of Nature and Natural Resources Red List of species. The Skagerrak beach seine survey from Norway constitutes the longest fishery-independent dataset on yellow/silver eels (starting in 1904). The Skagerrak coastal region receives larvae born in the Sargasso Sea spawning areas that have followed the Gulf Stream/North Atlantic Drift before they penetrate far into the North Sea. The Skagerrak coastal time series is therefore particularly valuable for exploring the impacts of oceanic factors on fluctuations in eel recruitment abundance. Analyses showed that Sargasso Sea surface temperature was negatively correlated with eel abundance, with a lag of 12 years revealing a cyclic and detrimental effect of high temperatures on the newly hatched larvae. The North Atlantic Oscillation index and inflow of North Atlantic water into the North Sea were negatively correlated with eel abundance, with a lag of 11 years. Increased currents towards the North Atlantic during high North Atlantic Oscillation years may send larvae into the subpolar gyre before they are ready to metamorphose and settle, resulting in low recruitment in the northern part of the distribution area for these years. The Skagerrak time series was compared with glass eel recruitment to freshwater in the Netherlands (Den Oever glass eel time series), and similar patterns were found revealing a cycle linked to changes in oceanic factors affecting glass eel recruitment. The recent decline of eels in the Skagerrak also coincided with previously documented shifts in environmental conditions of the North Sea ecosystem. PMID:20798112

Durif, Caroline M F; Gjøsaeter, Jakob; Vøllestad, L Asbjørn

2011-02-01

331

Influence of oceanic factors on Anguilla anguilla (L.) over the twentieth century in coastal habitats of the Skagerrak, southern Norway  

PubMed Central

The European eel (Anguilla anguilla L.) is distributed in coastal and inland habitats all over Europe, but spawns in the Sargasso Sea and is thus affected by both continental and oceanic factors. Since the 1980s a steady decline has been observed in the recruitment of glass eels to freshwater and in total eel landings. The eel is considered as critically endangered on the International Union for the Conservation of Nature and Natural Resources Red List of species. The Skagerrak beach seine survey from Norway constitutes the longest fishery-independent dataset on yellow/silver eels (starting in 1904). The Skagerrak coastal region receives larvae born in the Sargasso Sea spawning areas that have followed the Gulf Stream/North Atlantic Drift before they penetrate far into the North Sea. The Skagerrak coastal time series is therefore particularly valuable for exploring the impacts of oceanic factors on fluctuations in eel recruitment abundance. Analyses showed that Sargasso Sea surface temperature was negatively correlated with eel abundance, with a lag of 12 years revealing a cyclic and detrimental effect of high temperatures on the newly hatched larvae. The North Atlantic Oscillation index and inflow of North Atlantic water into the North Sea were negatively correlated with eel abundance, with a lag of 11 years. Increased currents towards the North Atlantic during high North Atlantic Oscillation years may send larvae into the subpolar gyre before they are ready to metamorphose and settle, resulting in low recruitment in the northern part of the distribution area for these years. The Skagerrak time series was compared with glass eel recruitment to freshwater in the Netherlands (Den Oever glass eel time series), and similar patterns were found revealing a cycle linked to changes in oceanic factors affecting glass eel recruitment. The recent decline of eels in the Skagerrak also coincided with previously documented shifts in environmental conditions of the North Sea ecosystem. PMID:20798112

Durif, Caroline M. F.; Gjøsæter, Jakob; Vøllestad, L. Asbjørn

2011-01-01

332

Response of biofilm-dwelling nematodes to habitat changes in the Garonne River, France: influence of hydrodynamics and microalgal availability  

Microsoft Academic Search

Lotic epilithic biofilms are submitted to seasonal disturbances (e.g. flood events, self-detachment), which influence the\\u000a biomass, diversity and viability of their algal and bacterial communities. The objective of this study is to examine whether\\u000a (1) biofilm-dwelling nematodes respond to such seasonal changes in terms of diversity and community structure, (2) nematode\\u000a species and feeding-types distribution respond to the varied trophic

Nabil Majdi; Walter Traunspurger; Stéphanie Boyer; Benoît Mialet; Michèle Tackx; Robert Fernandez; Stefanie Gehner; Loïc Ten-Hage; Evelyne Buffan-Dubau

2011-01-01

333

Influence of dams and habitat condition on the distribution of redhorse ( Moxostoma ) species in the Grand River watershed, Ontario  

Microsoft Academic Search

Redhorse, Moxostoma spp., are considered to be negatively affected by dams although this assertion is untested for Canadian populations. One\\u000a hundred and fifty-one sites in the Grand River watershed were sampled to identify factors influencing the distribution of\\u000a redhorse species. Individual species of redhorse were captured from 3 to 32% of sites. The most widespread species were golden\\u000a redhorse, M.

Scott M. Reid; Nicholas E. Mandrak; Leon M. Carl; Chris C. Wilson

2008-01-01

334

Workaholism and work-life imbalance: does cultural origin influence the relationship?  

PubMed

In recent years, workaholism has become prevalent throughout organizations and has captured the attention of organizational leaders as well as the academic and scientific communities. Most research in this area has focused on the negative consequences of workaholism, specifically work-life imbalance. One area of research that has largely been ignored is the potential influence of demographic variables on the relationship between workaholism and work-life imbalance. Therefore, the current study focused on how cultural origin might influence the intensity of this relationship. Based on relative deprivation theory and previous empirical work, it was expected that cultural origin would moderate the relationship between workaholism and work-life imbalance. Specifically, it was predicted that Caucasian participants would score higher on levels of workaholism than Black participants, and that the relationship between workaholism and work-life imbalance would be stronger for Caucasians than for Blacks. The results revealed that high levels of workaholism were significantly correlated with high levels of work-life imbalance. However, results also indicated that cultural origin did not moderate the relationship between workaholism and work-life imbalance, and there was no significant mean difference between Caucasian and Black participants on our measure of workaholism. These findings are important in that it is essential for employers to be aware of workaholic tendencies so they can better handle the negative consequences that result for the organization, and to also help promote the well-being of their employees. En los últimos años la adicción al trabajo se ha vuelto muy popular en las organizaciones y ha capturado la atención tanto de líderes organizacionales, así como de las comunidades científicas y académicas. La mayoría de investigaciones en esta área se han focalizado en las consequencias negativas de la adicción al trabajo (workoholismo), específicamente en el desequilibrio entre trabajo-vida. Una área de investigación que ha sido ignorada por mucho tiempo es la influencia potencial de las variables demográficas sobre la relación entre adicción al trabajo y el desequilibrio trabajo-vida. Por este motivo es que el presente estudio se focalizó en como el origen cultural puede influenciar la intensidad de esta relación. Tomando como base la teoría de la deprivación relativa y estudios empíricos previos, se esperó que el origen cultural moderaría la relación entre adicción al trabajo y desequilibrio trabajo-vida. Específicamente se pudo predecir que los participantes caucásicos mostraron más elevados puntajes en los niveles de adicción al trabajo que los participantes negros, y que la relación entre adicción al trabajo y desequilibrio trabajo-vida era más intensa entre los caucásicos que entre los negros. Los resultados revelaron que elevados niveles de adicción al trabajo correlacionaron significativamente con altos niveles de desequilibrio trabajo-vida. Sin embargo los resultados también revelaron que el origen cultural no moderaba la relación entre adicción al trabajo y desequilibrio trabajo-vida, y que además no había una diferencia significativa de medias entre los participantes caucásicos y negros respecto de nuestras mediciones de adicción al trabajo. Estos resultados son importantes en la medida en que es esencial para los empleadores el ser conscientes respecto de las tendencias de adicción al trabajo, lo que les permitirá manejar con mayor efectividad las consequencias negativas para la empresa resultantes de estas tendencias, y por otro lado apoyar a sus empleados en la promoción de su bienestar. Au cours des dernières années, le travaillolisme (workaholism) a pris de l'ampleur dans les organisations et a capté l'attention à la fois des dirigeants d'organisations et des communautés académique et scientifique. La majorité de la recherche dans ce domaine fut orientée sur les conséquences négatives du travaillolisme et, plus spécifiquement, sur le conflit travai

Aziz, Shahnaz; Adkins, Carrie T; Walker, Alan G; Wuensch, Karl L

2010-02-01

335

Socioeconomic influences on self-rated health in Russian men and women—a life course approach  

Microsoft Academic Search

Socio-economic differentials in health in Russia are not well understood and the life course approach has been relatively neglected. This paper examines the influence of socio-economic risk factors over the life course on the self-rated health of older Russian men and women. A random sample (response rate 61%) of the general population of the Russian Federation in 2002 included 1004

Amanda Nicholson; Martin Bobak; Michael Murphy; Richard Rose; Michael Marmot

2005-01-01

336

Religiosity and Spirituality: Influence on Quality of Life and Perceived Patient Self-Efficacy among Cardiac Patients and Their Spouses  

Microsoft Academic Search

The purpose of this study was to determine the influence of spirituality, religiosity, and religious coping on quality of\\u000a life and self-efficacy among couples following a first time cardiac event. There was no significant association between measures\\u000a for spirituality and religiosity and couples’ ratings for quality of life and self-efficacy. Negative forms of religious coping\\u000a were associated with lower levels

Joan F. Miller; Timothy R. McConnell; Troy A. Klinger

2007-01-01

337

Do Maternal Quality of Life and Breastfeeding Difficulties Influence the Continuation of Exclusive Breastfeeding?  

PubMed Central

Objectives. This study was conducted to determine whether maternal quality of life (QOL) and breastfeeding difficulties influence the continuation of exclusive breastfeeding (EBF). Methods. In a survey, 358 consecutive pregnant women filled out a quality of life questionnaire in the third trimester of pregnancy and the breastfeeding experience scale at 4 weeks postpartum. We assessed breastfeeding practices every month up to 6 months postpartum. Results. Only 11.8% of women continued EBF at six months. Mothers who continued EBF at 2 and 4 months postpartum had better QOL in late pregnancy than mothers who discontinued it (P < 0.05). There were no significant differences between the two groups in QOL scores at 6 months postpartum. Mothers who continued EBF at 2 months postpartum experienced less breastfeeding difficultties during one month postpartum than mothers who discontinued it (P < 0.05). Conclusion. In attempts to promote EBF, mothers with poor QOL or breastfeeding difficulties in early postpartum should be identified and helped. PMID:24868209

Mousavi, Seyed Abbas; Chaman, Reza; Khosravi, Ahmad

2014-01-01

338

The Influence of Power Limitations on Closed Environment Life Support System Applications  

NASA Technical Reports Server (NTRS)

The future of manned space exploration will be determined through a process which balances the innate need of humanity to explore its surroundings and the costs associated with accomplishing these goals. For NASA, this balance is derived from economics and budgetary constraints that hold it accountable for the expenditure of public funds. These budgetary realities demand a reduction in cost and expenditures of exploration and research activities. For missions venturing out to the edge of habitability, the development of cost effective life support approaches will have a significant influence on mission viability. Over the past several years, a variety of mission scenarios for potential Lunar and Mars missions have been developed. The most promising of these scenarios attempt to provide basic mission requirements at a minimum cost. As a result, these scenarios are extremely power limited. For Closed Environment Life Support System (CELSS) applications, these realities impose both limitations and direction to future research. This paper presents a summary of these mission scenarios and an evaluation of the impact which these power limitations will have on CELSS system design.

Flynn, Michael; Kliss, Mark (Technical Monitor)

1997-01-01

339

Evidence that life history characteristics of wild birds influence infection and exposure to influenza A viruses.  

PubMed

We report on life history characteristics, temporal, and age-related effects influencing the frequency of occurrence of avian influenza (AI) viruses in four species of migratory geese breeding on the Yukon-Kuskokwim Delta, Alaska. Emperor geese (Chen canagica), cackling geese (Branta hutchinsii), greater white-fronted geese (Anser albifrons), and black brant (Branta bernicla), were all tested for active infection of AI viruses upon arrival in early May, during nesting in June, and while molting in July and August, 2006-2010 (n?=?14,323). Additionally, prior exposure to AI viruses was assessed via prevalence of antibodies from sera samples collected during late summer in 2009 and 2010. Results suggest that geese are uncommonly infected by low pathogenic AI viruses while in Alaska. The percent of birds actively shedding AI viruses varied annually, and was highest in 2006 and 2010 (1-3%) and lowest in 2007, 2008, and 2009 (<0.70%). Contrary to findings in ducks, the highest incidence of infected birds was in late spring when birds first arrived from staging and wintering areas. Despite low prevalence, most geese were previously exposed to AI viruses, as indicated by high levels of seroprevalence during late summer (47%-96% across species; n?=?541). Seroprevalence was >95% for emperor geese, a species that spends part of its life cycle in Asia and is endemic to Alaska and the Bering Sea region, compared to 40-60% for the other three species, whose entire life cycles are within the western hemisphere. Birds <45 days of age showed little past exposure to AI viruses, although antibodies were detected in samples from 5-week old birds in 2009. Seroprevalence of known age black brant revealed that no birds <4 years old had seroconverted, compared to 49% of birds ?4 years of age. PMID:23469210

Ely, Craig R; Hall, Jeffrey S; Schmutz, Joel A; Pearce, John M; Terenzi, John; Sedinger, James S; Ip, Hon S

2013-01-01

340

Evidence that Life History Characteristics of Wild Birds Influence Infection and Exposure to Influenza A Viruses  

PubMed Central

We report on life history characteristics, temporal, and age-related effects influencing the frequency of occurrence of avian influenza (AI) viruses in four species of migratory geese breeding on the Yukon-Kuskokwim Delta, Alaska. Emperor geese (Chen canagica), cackling geese (Branta hutchinsii), greater white-fronted geese (Anser albifrons), and black brant (Branta bernicla), were all tested for active infection of AI viruses upon arrival in early May, during nesting in June, and while molting in July and August, 2006–2010 (n?=?14,323). Additionally, prior exposure to AI viruses was assessed via prevalence of antibodies from sera samples collected during late summer in 2009 and 2010. Results suggest that geese are uncommonly infected by low pathogenic AI viruses while in Alaska. The percent of birds actively shedding AI viruses varied annually, and was highest in 2006 and 2010 (1–3%) and lowest in 2007, 2008, and 2009 (<0.70%). Contrary to findings in ducks, the highest incidence of infected birds was in late spring when birds first arrived from staging and wintering areas. Despite low prevalence, most geese were previously exposed to AI viruses, as indicated by high levels of seroprevalence during late summer (47%–96% across species; n?=?541). Seroprevalence was >95% for emperor geese, a species that spends part of its life cycle in Asia and is endemic to Alaska and the Bering Sea region, compared to 40–60% for the other three species, whose entire life cycles are within the western hemisphere. Birds <45 days of age showed little past exposure to AI viruses, although antibodies were detected in samples from 5-week old birds in 2009. Seroprevalence of known age black brant revealed that no birds <4 years old had seroconverted, compared to 49% of birds ?4 years of age. PMID:23469210

Ely, Craig R.; Hall, Jeffrey S.; Schmutz, Joel A.; Pearce, John M.; Terenzi, John; Sedinger, James S.; Ip, Hon S.

2013-01-01

341

Factors Influencing Quality of Life of Obese Students in Hangzhou, China  

PubMed Central

Objective To evaluate the quality of life (QOL) of overweight and obese middle or high school students and identify relevant factors influencing their QOL scores. Methods 716 students were recruited from 6 middle or high schools in Hangzhou, China. The Chinese version of the Youth Quality of Life Instrument–Weight Module (YQOL-W) was self administered. The YQOL-W scores were compared among different BMI groups, gender, educational status, annual household income, parental education and recruitment community using t test or one-way analysis of variance. The independent association of these variables with QOL among overweight and obese students was examined using multivariable linear regression modeling. Results Overweight and obese students reported lower total scores, self, social and environment scores than their normal weight peers (all P<0.001). The QOL of overweight and obese middle and high school students was associated with BMI value, gender, educational status, parental education, and recruitment community. Girls had lower total scores, self, social and environment domain scores than boys (all P<0.001); high school students had lower total and three domain scores than middle school students (all P<0.05). Students whose fathers had higher education reported higher total scores, self and social scores than students with less educated fathers (all P<0.05). Students whose mothers had higher education reported higher environment scores than students with less educated mothers (P = 0.01). Students from migrant communities reported significantly lower total scores, self and social scores than those from rural communities (all P<0.05), but comparable scores with those from urban communities (P>0.05). Students from migrant communities reported comparable environment scores with those from rural and urban communities (P>0.05). Conclusions Overweight and obesity have negative effects on students’ quality of life. Therefore weight specific QOL could be included in weight reduction interventions as a relevant outcome. PMID:25799275

Chen, Ying-Ping; Wang, Hong-Mei; Edwards, Todd C.; Wang, Ting; Jiang, Xiao-Ying; Lv, Yi-Ran; Patrick, Donald L.

2015-01-01

342

Essential Fish Habitat and Critical Habitat  

E-print Network

Essential Fish Habitat and Critical Habitat: A comparison NOAA National Marine Fisheries Service #12;Essential fish habitat (EFH) is identified for species managed in Fishery Management Plans under the Magnuson-Stevens Fishery Conservation and Management Act. Essential fish habitat is the habitat necessary

343

Multi-scale geomorphic and hydrogeologic influences on bull trout (Salvelinus confluentus) spawning habitat in headwater streams  

NASA Astrophysics Data System (ADS)

We investigated multi-scale hydrogeomorphic influences on the distribution and abundance of bull trout (Salvelinus confluentus) spawning in snowmelt- dominated streams of the upper Flathead River basin, northwestern Montana. Bull trout redds were primarily found in unconfined alluvial valley reaches (74%), which were strongly influenced by hyporheic and groundwater-stream water exchange. A considerable proportion of redds (26%), however, were patchily distributed in confined valley reaches. Among all reaches and subreaches, the abundance of redds increased with increased bankfull dimensionless shear stress and decreased with reach-average streambed grain size (p < 0.05). Within these selected reaches and subreaches, redd occurrence tended to be associated with the finest available textural facies (i.e., gravel and small cobble substrates) in concave-up bedforms with downwelling intragravel flows. Streambed temperatures tracked stream water diurnal temperature cycles to a depth of at least 25 cm. Groundwater provided substantial thermal moderation of stream water for several high-density spawning reaches. Our spawning gravel competence results indicate that bull trout select spawning areas that are potentially susceptible to flooding-induced scour during the fall and winter incubation period.

Bean, J. R.; Wilcox, A. C.; Woessner, W. W.; Muhlfeld, C.

2013-12-01

344

An assessment of the relative influence of pain coping, negative thoughts about pain, and pain acceptance on health-related quality of life among people with hemophilia.  

PubMed

Many people with hemophilia are affected by chronic arthritic joint pain as well as acute bleeding pain. In this cross-sectional study, 209 men with hemophilia A or B completed the Hemophilia Pain Coping Questionnaire (HPCQ), the Chronic Pain Acceptance Questionnaire (CPAQ), and the RAND 36-item Health Survey (SF-36), a measure of health-related quality of life. Multiple regression was used to test the influence of active pain coping, passive adherence coping, and negative thoughts about pain (HPCQ scales), and activity engagement and pain willingness (CPAQ scales), on physical and mental components of quality of life (SF-36 PCS and MCS scales), taking account of age, hemophilia severity, use of clotting factor, and pain intensity. Pain intensity had the main influence on physical quality of life and negative thoughts had the main influence on mental quality of life. Activity engagement and pain willingness had small but significant influences on physical and mental quality of life. Pain willingness also moderated and partly mediated the influence of pain intensity on physical quality of life, and activity engagement and pain willingness mediated the influence of negative thoughts on mental quality of life. Negative thoughts moderated and partly mediated the influence of pain intensity on mental quality of life. There was no evidence that active pain coping influenced quality of life. The findings suggest that quality of life in hemophilia could potentially be improved by interventions to increase pain acceptance and reduce negative thoughts about pain. PMID:19573989

Elander, James; Robinson, Georgina; Mitchell, Kathryn; Morris, John

2009-09-01

345

Effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in Japan.  

PubMed

In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species. PMID:22943781

Naito, Risa; Yamasaki, Michimasa; Lmanishi, Ayumi; Natuhara, Yosihiro; Morimoto, Yukihiro

2012-09-01

346

Blood parasites in noddies and boobies from Brazilian offshore islands - differences between species and influence of nesting habitat.  

PubMed

Seabirds are often free from blood parasites, and a recent review suggested that phylogenetic, ecological and life-history parameters can determine the prevalence of blood parasites in seabirds. However, there is a lack of data available from many seabird groups, and a larger database is needed to understand prevalence patterns of blood parasites. We used a molecular screening approach to detect parasites of the genera Plasmodium, Haemoproteus, Leucocytozoon and Babesia in five species of two genera of seabirds that breed on Atlantic Ocean islands off Brazil. The observed patterns differed between the two bird genera. Like other Laridae, brown noddy, Anous stolidus adults were infected with Haemoproteus with low prevalence. Masked boobies, Sula dactylatra and brown boobies, Sula leucogaster were infected with Babesia. Of the latter, mainly juveniles were infected. In all species, intensity of infection (i.e. number of infected erythrocytes) was so low that parasites remained undetected in blood smears. This may explain the absence of major effects on the body condition of birds, although infected juvenile masked boobies were lighter than juveniles that were not infected with Babesia. Two tree-nesting species; black noddy, Anous minutus and red-footed booby, Sula sula did not have blood parasites, suggesting that tree-nesting may reduce the exposure to arthropod vectors compared with ground nesting in these species. PMID:24229724

Quillfeldt, Petra; Martínez, Javier; Bugoni, Leandro; Mancini, Patrícia L; Merino, Santiago

2014-03-01

347

Habitat Observations  

NSDL National Science Digital Library

In this outdoor activity, learners discover the wonders of the habitat surrounding them. After reading "The Empty Lot," a picture book by Dale Fife, learners observe and record in writing what happens in the natural environment around them. Spending time outdoors observing nature can help learners better understand and appreciate the world in which we live.

2012-06-26

348

When Giants Turn Up: Sighting Trends, Environmental Influences and Habitat Use of the Manta Ray Manta alfredi at a Coral Reef  

PubMed Central

Manta rays Manta alfredi are present all year round at Lady Elliot Island (LEI) in the southern Great Barrier Reef, Australia, with peaks in abundance during autumn and winter. Drivers influencing these fluctuations in abundance of M. alfredi at the site remain uncertain. Based on daily count, behavioural, weather and oceanographic data collected over a three-year period, this study examined the link between the relative number of sightings of manta rays at LEI, the biophysical environment, and the habitat use of individuals around the LEI reef using generalised additive models. The response variable in each of the three generalised additive models was number of sightings (per trip at sea) of cruising, cleaning or foraging M. alfredi. We used a set of eleven temporal, meteorological, biological, oceanographic and lunar predictor variables. Results for cruising, cleaning and foraging M. alfredi explained 27.5%, 32.8% and 36.3% of the deviance observed in the respective models and highlighted five predictors (year, day of year, wind speed, chlorophyll-a concentration and fraction of moon illuminated) as common influences to the three models. There were more manta rays at LEI in autumn and winter, slower wind speeds, higher productivity, and around the new and full moon. The winter peak in sightings of foraging M. alfredi was found to precede peaks in cleaning and cruising activity around the LEI reef, which suggests that enhanced food availability may be a principal driver for this seasonal aggregation. A spatial analysis of behavioural observations highlighted several sites around the LEI reef as ‘multi-purpose’ areas where cleaning and foraging activities commonly occur, while the southern end of the reef is primarily a foraging area. The use of extensive citizen science datasets, such as those collected by dive operators in this study, is encouraged as they can provide valuable insights into a species' ecology. PMID:23056255

Jaine, Fabrice R. A.; Couturier, Lydie I. E.; Weeks, Scarla J.; Townsend, Kathy A.; Bennett, Michael B.; Fiora, Kym; Richardson, Anthony J.

2012-01-01

349

10/24/13 nsf.gov -National Science Foundation (NSF) News -Habitat research methods give a new peek at tiger life with conservation -US National Science Foundat... nsf.gov/news/news_summ.jsp?cntn_id=129355 1/1  

E-print Network

peek at tiger life with conservation - US National Science Foundat... nsf.gov/news/news_summ.jsp?cntn_id=129355 1/1 News From the Field HABITAT RESEARCH METHODS GIVE A NEW PEEK AT TIGER LIFE WITH CONSERVATION October 21, 2013 From a tiger's point of view, yesterday's thoughtful conservation plans might

350

Influence of Bovine Slurry Deposition on the Structure of Nodulating Rhizobium leguminosarum bv. viciae Soil Populations in a Natural Habitat  

PubMed Central

The population of nodulating R. leguminosarum bv. viciae in soil from a grass-covered valley area which had been used for bovine slurry deposition over a period of 5 years was analyzed. For these studies, a rapid and reproducible method based on enterobacterial repetitive intergenic consensus (ERIC)-PCR was applied to identify Rhizobium strains which had infected pea nodules. Soil samples were taken from different areas and further analyzed in plant tests to determine the impact of the application of slurry (polluted or nonpolluted), the slope position (summit or toe), and exposure (north or south). After comparison of all PCR fingerprint patterns, 24 strain groups were defined. Some strain groups from the nonpolluted soil were suppressed in the polluted samples, and new strain groups were detected in the slurry-polluted soil. After analyzing relationships between the strain groups, we determined the influences of local factors on the nodulating R. leguminosarum bv. viciae population. We show that one of those local parameters, slope position, had significantly greater impact on the composition of the Rhizobium population than the presence of slurry. PMID:16535318

Labes, G.; Ulrich, A.; Lentzsch, P.

1996-01-01

351

The Succession, Habitat Affinity, and Life-forms of Epiphytic Bryophytes in the Turkish Oak (Quercus cerris) Forests on Mount Musa  

Microsoft Academic Search

We studied the epiphytic bryophytes in the deciduous Quercus cerris forests on Mount Musa in the southern part of the Amanos Mountain Range. An Index of Ecological Significance (IES) was used to evaluate the ecological importance of the species in the epiphytic habitats. In a total of 94 quadrats, 4 dm2 each, we observed 25 species of bryophytes (6 liverworts,

Tulay Ezer; Recep KARA; Atabay DUZENLI

2009-01-01

352

Fruit productivity and other life history traits of Maesopsis eminii at a forest edge and in a closed habitat of Amani, East Usambara Mts.Tanzania  

Microsoft Academic Search

The amount of fruits produced by tree species in tropical forest ecosystems depends on water availability, soil types, amount of insolation and structural features among other factors. Fruit productivity of the introduced invasive tree Maesopsis eminii at the edge and in closed habitats was investigated at three different study sites within Amani Nature Reserve (ANR), East Usambara Mountains -Tanzania. Fruits

Simon Nganda Musila

353

Woody debris, voles, and trees: Influence of habitat structures (piles and windrows) on long-tailed vole populations and feeding damage  

Microsoft Academic Search

Coarse woody debris (CWD) has many ecological functions ranging from conservation of biodiversity to long-term ecosystem productivity. Wildlife habitat, in particular, has been the focus of CWD investigations aimed at maintaining mammal species in managed forests. Piles and windrows of post-harvest woody debris could be designed to provide connectivity and habitat across clearcut openings for a wide array of mammalian

Thomas P. Sullivan; Druscilla S. Sullivan

354

Influences of Children's and Adolescents' Action-Control Processes on School Achievement, Peer Relationships, and Coping with Challenging Life Events  

ERIC Educational Resources Information Center

Self-regulation represents a core aspect of human functioning that influences positive development across the life span. This chapter focuses on the action-control model, a key facet of self-regulation during childhood and early adolescence. The authors discuss the development of action-control beliefs, paying particular attention to their…

Geldhof, G. John; Little, Todd D.

2011-01-01

355

Correlates of Life Style: Personality, Role Concept, Attitudes, Influences, and Choices  

Microsoft Academic Search

Using the California Psychological Inventory, the Inventory of Women's Life Styles, and the Inventory of Women's Role Concept and Attitudes, three separate life-style patterns were delineated for women leading Traditional, Neotraditional, and Nontraditional life styles. These women differed significantly in personality; role concepts; attitudes; choices of college majors and occupations; motivation; quality of employment experiences; parents' life styles; perceptions of

Agnes N. OConnell

1980-01-01

356

TSPO ligand residence time influences human glioblastoma multiforme cell death/life balance.  

PubMed

Ligands addressed to the mitochondrial Translocator Protein (TSPO) have been suggested as cell death/life and steroidogenesis modulators. Thus, TSPO ligands have been proposed as drug candidates in several diseases; nevertheless, a correlation between their binding affinity and in vitro efficacy has not been demonstrated yet, questioning the specificity of the observed effects. Since drug-target residence time is an emerging parameter able to influence drug pharmacological features, herein, the interaction between TSPO and irDE-MPIGA, a covalent TSPO ligand, was investigated in order to explore TSPO control on death/life processes in a standardized glioblastoma cell setting. After 90 min irDE-MPIGA cell treatment, 25 nM ligand concentration saturated irreversibly all TSPO binding sites; after 24 h, TSPO de-novo synthesis occurred and about 40 % TSPO binding sites resulted covalently bound to irDE-MPIGA. During cell culture treatments, several dynamic events were observed: (a) early apoptotic markers appeared, such as mitochondrial membrane potential collapse (at 3 h) and externalization of phosphatidylserine (at 6 h); (b) cell viability was reduced (at 6 h), without cell cycle arrest. After digitonin-permeabilized cell suspension treatment, a modulation of mitochondrial permeability transition pore was evidenced. Similar effects were elicited by the reversible TSPO ligand PIGA only when applied at micromolar dose. Interestingly, after 6 h, irDE-MPIGA cell exposure restored cell survival parameters. These results highlighted the ligand-target residence time and the cellular setting are crucial parameters that should be taken into account to understand the drug binding affinity and efficacy correlation and, above all, to translate efficiently cellular drug responses from bench to bedside. PMID:25413799

Costa, Barbara; Da Pozzo, Eleonora; Giacomelli, Chiara; Taliani, Sabrina; Bendinelli, Sara; Barresi, Elisabetta; Da Settimo, Federico; Martini, Claudia

2015-03-01

357

Genetic and environmental influences on atopic immune response in early life.  

PubMed

The purpose of our study was to carry out a prospective follow-up of 114 newborns at term (including three pairs of twins), regarding clinical manifestations for atopy during the first year of life. Their IgE levels in cord blood samples, at 3, 6, 9 and 12 months of age were measured and the influence of race, sex, breast-feeding, maternal smoking, family income, month of birth, family history and personal manifestations of atopic disease were evaluated. Total serum immunoglobulin E was quantified by microparticle enzyme immuno-assay (MEIA). The study group consisted of 60 (53%) male neonates, 67 (59%) Caucasians and 47 (41%) blacks. In the clinical follow-up, 32 (28.1%) infants developed obvious atopic disease: 29 infants presented recurrent wheezing, two had cow's milk allergy and one had atopic dermatitis. Probable atopic disease developed in 12 (10.5%) infants, whereas 70 (61.4%) infants showed no manifestations. Cord blood IgE levels in infants with obvious atopic disease was higher when compared to those without (p = 0.024), with 70.97% sensitivity and 46.2% specificity. IgE levels were also significantly different up to 12 months in these groups (p = 0.0001), when the sensitivity was 82.1% and the specificity 54.1%. At this age, the IgE levels were higher in infants with obvious atopy than nonatopic disease in relation to male sex (p = 0.015), black race (p = 0.009), breast-feeding for less than 6 months (p = 0.011) and when the family income was less than three times the minimum wage (about US $300) (p = 0.006). There was no association between IgE levels and family history of atopy. We concluded that immune response for atopy was in a large degree influenced by environmental factors and serum IgE at 12 months was a good marker for identifying infants with risk of atopic disease in early life. PMID:10664935

López, N; de Barros-Mazón, S; Vilela, M M; Silva, C M; Ribeiro, J D

1999-01-01

358

The Family Context of Autism Spectrum Disorders: Influence on the Behavioral Phenotype and Quality of Life  

PubMed Central

Synopsis In this review, we report the findings from our longitudinal program of research examining the bidirectional influences of the family environment on the behavioral phenotype of autism, and describe a newly developed family psychoeducation program, titled Transitioning Together, designed to reduce family stress, address behavior problems, and improve the overall quality of life of adolescents with autism and their families. In our search for characteristics of the family environment that influence the behavioral phenotype of adolescents and adults with autism, we focus on both positive dimensions of family life, such as warmth and positive remarks that may promote adaptive behavior in individuals with autism, as well as negative dimensions, such as high levels of criticism that may result in an escalation of behavior problems. We find that high levels of maternal warmth and positive remarks are associated with the abatement of behavior problems over time, while high levels of maternal criticism are associated with increasing levels of behavior problems in adolescents and adults with autism. These patterns of relationships have been replicated in a longitudinal study of families of children and adolescents with fragile X syndrome, and are consistent with other studies examining the impact of the family on the behavior of children with developmental disabilities. These findings suggest that the family environment is an important target for interventions not only to reduce family stress but also to improve the behavioral functioning of children, adolescents or adults with ASD. Building upon a well-developed intervention for families of individuals with psychiatric conditions, we report on the development of Transitioning Together, a psychoeducation program targeted to families with adolescents with autism who are approaching high school exit, a difficult transition stage for individuals with autism that is often marked by negative changes in behavior problems. The 8-week Transitioning Together program involves education on a variety of topics relevant to ASD and guided practice in helping families better manage problem behavior in adolescents with autism. Preliminary data suggest that the program can improve the parent-child relationship and increase parental expressions of warmth. A case study is presented that illustrates how Transitioning Together helps reduce family stress and improve the overall quality of the family environment. We conclude the article with a discussion of directions for future research on best practices in working with families of children, adolescents and adults with autism. PMID:24231173

Smith, Leann E.; Greenberg, Jan; Mailick, Marsha R.

2013-01-01

359

Habitat Quality Affects Early Physiology and Subsequent Neuromotor Development of Juvenile Black-Capped Chickadees  

PubMed Central

In songbirds, the ability to learn and render the species-specific song is influenced by the development of both the song nuclei in the brain and the syrinx (bird's vocal apparatus) early in the bird's life. In black-capped chickadees (Poecille atricapillus), habitat quality is known to affect song structure, with birds in high-quality habitat (mature forest) having a higher song consistency than birds in low-quality habitat (young forest). Although this difference is suspected to stem from differences in development, the developmental status of juvenile birds in either habitat remains unexplored. In this study, we used ptilochronology and feather corticosterone to compare the conditional state of juvenile chickadees in young and mature forest during two distinct periods of song learning - the sensory phase, which occurs prior to settlement, and the sensorimotor phase, which occurs post-settlement. A sample of juvenile males was captured and euthanized several weeks prior to their first breeding season to compare the development of song center nuclei and syrinx in both habitats. The corticosterone levels of natally-grown feathers were greater among birds that settled in mature than young forests - as these feathers were grown pre-settlement, they reflect differences in physiology during the sensory phase. This difference in conditional state is reflected by differences in syrinx and song center nuclei development later during the sensorimotor phase - birds in young forest have smaller syrinx, and moderately-larger RA, than birds in mature forest. Those differences could be responsible for the difference in consistency in song structure observed across habitats. The difference in physiological state across habitats, combined with potential compounding effect of differences in winter resources between habitats, could influence the difference in syrinx and neural development seen in juvenile males during the early spring, and influence the male's ability to learn and render their species-specific song. PMID:23951257

Grava, Thibault; Fairhurst, Graham D.; Avey, Marc T.; Grava, Angelique; Bradley, James; Avis, Jillian L.; Bortolotti, Gary R.; Sturdy, Christopher B.; Otter, Ken A.

2013-01-01

360

Interactions between habitat heterogeneity and food affect reproductive output in a top predator.  

PubMed

1. Habitat heterogeneity has important repercussions for species abundance, demography and life-history patterns. While habitat effects have been more thoroughly studied in top-down situations (e.g. in association with predation), their role in bottom-up situations (e.g. in association with food abundance) has been less explored and the underlying mechanism(s) behind the ecological patterns have not commonly been identified. 2. With material from 1993 to 2003, we test the hypothesis that the reproduction of Finnish northern goshawks Accipiter gentilis (L.) is bottom-up limited by habitat composition, especially in situations where the density of their main prey (grouse) is low. Special emphasis was placed on identifying the mechanism(s) behind potential habitat effects. 3. While laying date and large-scale variation in the main prey density (but not habitat composition) were related to the number of eggs goshawks laid, small-scale differences in alternative prey density between different territories later influenced how many young were fledged via the mechanism of habitat-dependent partial-brood loss. As a result of this mechanism, a difference in nestling condition also arose between goshawk territories with differing habitat compositions. 4. As the relative proportions of different landscape elements in a given landscape is a function of large-scale differences in geomorphology and land use, this means that the reproductive performance of goshawks as averaged over larger scales can be understood correctly only in respect to the fact that habitat gradients differ across landscapes. 5. In addition to being one of the first papers identifying the mechanism of partial brood loss as being primarily responsible for the habitat-specific differences in the production of young, this study further illustrates the need to identify small-scale mechanisms to correctly understand the large-scale patterns of reproductive performance in territorial species. The repercussions of the observed habitat effect for local population development are discussed. PMID:17302847

Byholm, Patrik; Nikula, Ari; Kentta, Jussi; Taivalmäki, Jukka-Pekka

2007-03-01

361

Factors influencing the life cycle burdens of the recovery of energy from residual municipal waste.  

PubMed

A life cycle assessment was carried out to assess a selection of the factors influencing the environmental impacts and benefits of incinerating the fraction of municipal waste remaining after source-separation for reuse, recycling, composting or anaerobic digestion. The factors investigated were the extent of any metal and aggregate recovery from the bottom ash, the thermal efficiency of the process, and the conventional fuel for electricity generation displaced by the power generated. The results demonstrate that incineration has significant advantages over landfill with lower impacts from climate change, resource depletion, acidification, eutrophication human toxicity and aquatic ecotoxicity. To maximise the benefits of energy recovery, metals, particularly aluminium, should be reclaimed from the residual bottom ash and the energy recovery stage of the process should be as efficient as possible. The overall environmental benefits/burdens of energy from waste also strongly depend on the source of the power displaced by the energy from waste, with coal giving the greatest benefits and combined cycle turbines fuelled by natural gas the lowest of those considered. Regardless of the conventional power displaced incineration presents a lower environmental burden than landfill. PMID:25758908

Burnley, Stephen; Coleman, Terry; Peirce, Adam

2015-05-01

362

Aquagenic pruritus in polycythemia vera: characteristics and influence on quality of life in 441 patients.  

PubMed

Aquagenic pruritus (AP) is a symptom typical for polycythemia vera, but very little is known about its exact frequency, characteristics, influence on quality of life, and proper treatment. Therefore, we investigated these aspects in a large cohort of German patients with polycythemia vera using a patient directed questionnaire. Our analysis revealed that 301 of 441 analyzed patients suffered from AP. In 64.8%, AP occurred on average 2.9 years prior to diagnosis of polycythemia vera. Only in 15.4% did this lead to a hematological investigation. AP occurs primarily on the trunk and proximal parts of the extremities. Most patients complain about itching (71.8%), the remainder about tickling, stinging, or burning sensations. Forty-four patients (14.6%) classified the pruritus as "unbearable." Patients with AP reported reduced global health status and higher fatigue, pain, and dyspnea. Only 24% of patients received pruritus specific treatment for pruritus consisting mostly of histamine antagonists, which ameliorated symptoms in about half of the patients. In 5.6% of patients, polycythemia vera directed therapy (phlebotomy/cytoreduction) resolved the symptoms. In summary, AP is a serious symptom in patients with polycythemia vera, which until recently was difficult to treat. The advent of the novel JAK2 inhibitors, however, may open new ways for therapy. PMID:23657863

Siegel, Fabian P; Tauscher, Jan; Petrides, Petro E

2013-08-01

363

Life history influences rates of climatic niche evolution in flowering plants  

PubMed Central

Across angiosperms, variable rates of molecular substitution are linked with life-history attributes associated with woody and herbaceous growth forms. As the number of generations per unit time is correlated with molecular substitution rates, it is expected that rates of phenotypic evolution would also be influenced by differences in generation times. Here, we make the first broad-scale comparison of growth-form-dependent rates of niche evolution. We examined the climatic niches of species on large time-calibrated phylogenies of five angiosperm clades and found that woody lineages have accumulated fewer changes per million years in climatic niche space than related herbaceous lineages. Also, climate space explored by woody lineages is consistently smaller than sister lineages composed mainly of herbaceous taxa. This pattern is probably linked to differences in the rate of climatic niche evolution. These results have implications for niche conservatism; in particular, the role of niche conservatism in the distribution of plant biodiversity. The consistent differences in the rate of climatic niche evolution also emphasize the need to incorporate models of phenotypic evolution that allow for rate heterogeneity when examining large datasets. PMID:19776076

Smith, Stephen A.; Beaulieu, Jeremy M.

2009-01-01

364

OIKOS 98: 8797, 2002 Population history and life history influence the migration rate of  

E-print Network

) that is not present in the release area, where there is only Plantago lanceolata, the preferred host plant of females. First, Veronica-preferring females had higher emigration rate than Plantago-preferring females from the Plantago-con- taining release patches, demonstrating that the individual perception of habitat quality

Hanski, Ilkka

365

Relationship of External Influence to Parental Distress in Decision Making Regarding Children with a Life-Threatening Illness  

PubMed Central

Objective?To examine the relationship of external influence to parental distress when making a decision about research or treatment for a child with a life-threatening illness and to test potential moderators of this relationship.?Methods?Parents (n?=?219) who made a decision about research or treatment for a child completed measures of external influence, distress, decision-making preference, and coping.?Results?More external influence was associated with more hostility, uncertainty, and confusion. Decision-making preference and coping style moderated the relationship between external influence and distress: More external influence was associated with more distress when decision-making preference was low and task-focused coping was high.?Conclusions External influence appears to be related to distress in parents making research and treatment decisions for children with life-threatening illnesses. However, it is important to consider parent characteristics, such as decision-making preference and coping style, when examining the effects of contextual factors on distress during decision making. PMID:21693541

Luce, Mary Frances; Nelson, Robert M.

2011-01-01

366

It's a Frog's Life  

NSDL National Science Digital Library

When a preschool teacher unexpectedly found tadpoles in the school's outdoor baby pool, she recognized an unusual opportunity for her students to study pond life up close. By following the tadpoles' development, students learned about frogs, life cycles, habitats.

Audrey L. Coffey

2003-09-01

367

PROGRAM TO ASSIST IN TRACKING CRITICAL HABITAT  

EPA Science Inventory

PATCH is a spatially explicit, individual-based, life history simulator designed to project populations of territorial terrestrial vertebrate species through time. PATCH is ideal for investigations involving wildlife species that are mobile habitat specialists. PATCH's data req...

368

Lunar and Planetary Bases, Habitats, and Colonies  

NASA Technical Reports Server (NTRS)

This special bibliography includes the design and construction of lunar and Mars bases, habitats, and settlements; construction materials and equipment; life support systems; base operations and logistics; thermal management and power systems; and robotic systems.

2004-01-01

369

Habitat and Scale Shape the Demographic Fate of the Keystone Sea Urchin Paracentrotus lividus in Mediterranean Macrophyte Communities  

PubMed Central

Demographic processes exert different degrees of control as individuals grow, and in species that span several habitats and spatial scales, this can influence our ability to predict their population at a particular life-history stage given the previous life stage. In particular, when keystone species are involved, this relative coupling between demographic stages can have significant implications for the functioning of ecosystems. We examined benthic and pelagic abundances of the sea urchin Paracentrotus lividus in order to: 1) understand the main life-history bottlenecks by observing the degree of coupling between demographic stages; and 2) explore the processes driving these linkages. P. lividus is the dominant invertebrate herbivore in the Mediterranean Sea, and has been repeatedly observed to overgraze shallow beds of the seagrass Posidonia oceanica and rocky macroalgal communities. We used a hierarchical sampling design at different spatial scales (100 s, 10 s and <1 km) and habitats (seagrass and rocky macroalgae) to describe the spatial patterns in the abundance of different demographic stages (larvae, settlers, recruits and adults). Our results indicate that large-scale factors (potentially currents, nutrients, temperature, etc.) determine larval availability and settlement in the pelagic stages of urchin life history. In rocky macroalgal habitats, benthic processes (like predation) acting at large or medium scales drive adult abundances. In contrast, adult numbers in seagrass meadows are most likely influenced by factors like local migration (from adjoining rocky habitats) functioning at much smaller scales. The complexity of spatial and habitat-dependent processes shaping urchin populations demands a multiplicity of approaches when addressing habitat conservation actions, yet such actions are currently mostly aimed at managing predation processes and fish numbers. We argue that a more holistic ecosystem management also needs to incorporate the landscape and habitat-quality level processes (eutrophication, fragmentation, etc.) that together regulate the populations of this keystone herbivore. PMID:22536355

Prado, Patricia; Tomas, Fiona; Pinna, Stefania; Farina, Simone; Roca, Guillem; Ceccherelli, Giulia; Romero, Javier; Alcoverro, Teresa

2012-01-01

370

Influence of level of education on disability free life expectancy by sex: the ILSA study  

Microsoft Academic Search

PurposeTo assess the effect of education on Disability Free Life Expectancy among older Italians, using a hierarchical model as indicator of disability, with estimates based on the multistate life table method and IMaCh software.

N. Minicuci

2005-01-01

371

The influence of habitat structure on nearshore fish assemblages in a southern Australian embayment: Comparison of shallow seagrass, reef-algal and unvegetated sand habitats, with emphasis on their importance to recruitment  

Microsoft Academic Search

Assemblage structure and juvenile recruitment of fishes was compared amongst three habitats: seagrass, Heterozostera tasmanica (Martens ex Aschers.) den Hartog; reef-algal; and unvegetated sand. Sampling was conducted monthly from October 1993 to March 1994 at three locations in Port Phillip Bay, southern Australia. A fine-mesh seine net was used to sample subtidally at a depth of approximately 0.5 m. Fish

Gregory P Jenkins; Melissa J Wheatley

1998-01-01

372

Life Without Parole: The Influence of Age and Race on the Sentencing of Juvenile Offenders  

Microsoft Academic Search

In 2010, the Supreme Court ruled it unconstitutional to sentence adolescents charged with non-homicide crimes to life without parole (Graham v. Florida, 2012). Currently, research regarding life without parole is assessed in conjunction with the death penalty, in which life without parole is proposed as a lesser alternative to the death penalty. The current study investigated whether age and race

Maria Annabel Mireles

2012-01-01

373

Spatial and temporal shifts in suitable habitat of juvenile southern flounder (Paralichthys lethostigma)  

NASA Astrophysics Data System (ADS)

Factors influencing suitable habitats of juvenile southern flounder (Paralichthys lethostigma) within the Galveston Bay Complex (GBC), Texas, were assessed using generalized additive models (GAM). Fishery independent data collected with bag seines throughout the GBC from 1999 to 2009 were used to predict the probability of southern flounder occurrence. Binomial GAMs were used to assess presence/absence of southern flounder and models included temporal variables, benthic variables such as distance to habitats generated within a geographic information system, and physicochemical conditions of the water column. Separate models were generated for newly settled southern flounder, young-of-the-year (YOY) southern flounder observed in the summer, and YOY southern flounder observed in fall based on size and collection month. Factors affecting southern flounder occurrence changed seasonally, as did the corresponding shifts in the spatial distribution of suitable habitat. Temporal effects (year and month) were retained in all models. Physicochemical conditions (temperature, turbidity, and measures of environmental variability), and the presence of seagrass beds were influential for newly settled southern flounder. Distance to marine and/or freshwater sources were found to be important for YOY southern flounder in the summer and fall seasons. The abundance of brown shrimp was found to only influence the distribution of YOY southern flounder in the fall, when intermediate abundances of the potential prey item increased the occurrence of southern flounder. After model completion, the availability and spatial distribution of suitable habitat within the GBC was predicted using available environmental and spatial data for 2005. Spatial distributions of predicted suitable habitat stress the relative importance of West Bay during the newly settled stage and in the fall season, and Upper Bay during the summer and fall of the first year of life. These models demonstrate the potential dynamics of suitable habitats for juvenile southern flounder and provide insight into ontogenetic shifts in habitat preference during the first year of life.

Furey, Nathan B.; Rooker, Jay R.

2013-02-01

374

Large-scale occurrence patterns of red-listed lichens and fungi on old oaks are influenced both by current and historical habitat density  

Microsoft Academic Search

Current occurrence patterns of species associated with ancient trees may reflect higher historical habitat densities, because\\u000a the dynamics of the habitat and the colonisation-extinction processes for many inhabiting species are expected to be slow.\\u000a We tested this hypothesis in southeast Sweden by analysing species occurrence per parish for twelve redlisted lichen species\\u000a and nine redlisted fungus species in relation with

Thomas Ranius; Per Eliasson; Per Johansson

2008-01-01

375

Influence of habitat dynamics on the distribution and abundance of the federally threatened Santa Ana Sucker, Catostomus santaanae , in the Santa Ana River  

Microsoft Academic Search

Habitat degradation affects native stream fish populations worldwide. We examined the impact of fluctuation in environmental\\u000a variables on the population dynamics of the federally threatened Santa Ana sucker, Catostomus santaanae, in the Santa Ana River, California through: 1) annual quantitative surveys of C. santaanae abundance and habitat at three 100-m sites between 2001 and 2008 and 2) annual surveys of

Andrew Richard Thompson; Jonathan N. Baskin; Camm C. Swift; Thomas R. Haglund; Randall J. Nagel

2010-01-01

376

The Influence of BMI and Predictors of Disordered Eating and Life Satisfaction on Postmenopausal Women.  

PubMed

This study aims to compare eating behaviors, body satisfaction, exercise, and life satisfaction between normal-weight and overweight postmenopausal women and to examine the predictors of disordered eating and life satisfaction among postmenopausal women (n = 294). The overweight group had more eating disordered behavior, more body dissatisfaction, and lower physical quality of life. The increase of age predicted less disordered eating. Higher BMI, the perception of an ideal weight lower than the current one, lower body satisfaction, and physical quality of life predicted disordered eating. Higher body satisfaction, less psychosocial discomfort, and a greater degree of sexual symptom discomfort predicted life satisfaction. PMID:25581463

Gonçalves, Sónia F; Silva, Elsa; Gomes, A Rui

2015-01-01

377

Slipping through the Cracks: Rubber Plantation Is Unsuitable Breeding Habitat for Frogs in Xishuangbanna, China  

PubMed Central

Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province – a hotspot of frog diversity within China – two-thirds of the native tropical rainforests have been converted into rubber plantation agriculture. We conducted surveys and experiments to quantify habitat use for breeding and non-breeding life history activities of the native frog species in rainforest, rubber plantation and other human impacted sites. Rubber plantation sites had the lowest species richness in our non-breeding habitat surveys and no species used rubber plantation sites as breeding habitat. The absence of breeding was likely not due to intrinsic properties of the rubber plantation pools, as our experiments indicated that rubber plantation pools were suitable for tadpole growth and development. Rather, the absence of breeding in the rubber plantation was likely due to a misalignment of breeding and non-breeding habitat preferences. Analyses of our breeding surveys showed that percent canopy cover over pools was the strongest environmental variable influencing breeding site selection, with species exhibiting preferences for pools under both high and low canopy cover. Although rubber plantation pools had high canopy cover, the only species that bred in high canopy cover sites used the rainforest for both non-breeding and breeding activities, completing their entire life cycle in the rainforest. Conversely, the species that did use the rubber plantation for non-breeding habitat preferred to breed in low canopy sites, also avoiding breeding in the rubber plantation. Rubber plantations are likely an intermediate habitat type that ‘slips through the cracks’ of species habitat preferences and is thus avoided for breeding. In summary, unlike the rainforests they replaced, rubber plantations alone may not be able to support frog populations. PMID:24040026

Behm, Jocelyn E.; Yang, Xiaodong; Chen, Jin

2013-01-01

378

Urban Habitats  

NSDL National Science Digital Library

_Urban Habitats_, published by the Center for Urban Restoration Ecology (CURE), is "a peer-reviewed, fully indexed scientific journal written and edited for a wide audience of researchers, restoration ecologists, park and preserve managers, government officials, and naturalists." The premier issue of this e-journal (focused on urban flora worldwide) is available online, and researchers are encouraged to submit articles and multimedia resources for future issues (detailed submission guidelines provided). CURE is a joint project of Rutgers University and the Brooklyn Botanic Garden.

379

Scale-dependent habitat use in three species of prairie wetland birds  

Microsoft Academic Search

We evaluated the influence of scale on habitat use for three wetland-obligate bird species with divergent life history characteristics and possible scale-dependent criteria for nesting and foraging in South Dakota, USA. A stratified, two-stage cluster sample was used to randomly select survey wetlands within strata defined by region, wetland density, and wetland surface area. We used 18-m (0.1 ha) fixed radius

David E. Naugle; Kenneth F. Higgins; Sarah M. Nusser; W. Carter Johnson

1999-01-01

380

Life history and habitat associations of the broad wood cockroach, Parcoblatta lata (Blattaria: Blattellidae) and other native cockroaches in the Coastal Plain of South Carolina.  

SciTech Connect

Wood cockroaches are an important prey of the red-cockaded woodpecker, Picoides borealis, an endangered species inhabiting pine forests in the southern United States. These woodpeckers forage on the boles of live pine trees, but their prey consists of a high proportion of wood cockroaches, Parcoblatta spp., that are more commonly associated with dead plant material. Cockroach population density samples were conducted on live pine trees, dead snags and coarse woody debris on the ground. The studies showed that snags and logs are also important habitats of wood cockroaches in pine forests.

Horn, Scott; Hanula, James, L.

2002-06-18

381

CHANGING HABITATS AND POPULATIONS: CHANGING OPPORTUNITIES  

Microsoft Academic Search

On private rangelands west of the Mississippi, long-term changes have altered habitats, wildlife popu- lations and opportunities for the rancher. These changes may or not be irreversible depending on the site conditions of each particular ranch. There may be opportunities for ranchers to alter habitats and influence the abundance or distribution of wildlife species if their goal is to enhance

Fred Bryant

382

Habitat Characteristics of Past Delta Landscapes  

E-print Network

of relationships between physical processes, habitat, and ecological function Describes the conditions within which Habitat Map (DRAFT) #12;FLOOD BASINS TIDAL ISLANDS DISTRIBUTARY RIVERS Delta Landscapes #12;Flood Basins Tidal Islands Distributary Rivers Relative tidal influence limited by natural levees and flood basin

383

Maternal and early life influences on calcaneal ultrasound parameters and metacarpal morphometry in 7- to 9-year-old children  

Microsoft Academic Search

We investigated the relationship between maternal and early life influences, calcaneal ultrasound parameters, and metacarpal\\u000a morphometry in 7- to 9-year-old children (n = 109) of mixed ancestral origin from a working class community. Their mothers had participated in a nutrition and pregnancy\\u000a study at the time of the birth. Demographic and maternal data were collected. Anthropometry was assessed. Broadband ultrasound

Lisa Micklesfield; Naomi Levitt; Muhammed Dhansay; Shane Norris; Lize van der Merwe; Estelle Lambert

2006-01-01

384

Pathological Gambling: Influence of Quality of Life and Psychological Distress on Abstinence After Cognitive-Behavioral Inpatient Treatment  

Microsoft Academic Search

The aim of this study is to understand the influence of psychological distress and quality of life on the maintenance of therapy\\u000a success during a 1 year follow-up in pathological gamblers after inpatient cognitive-behavioral treatment. In a sample of\\u000a 281 pathological gamblers (247 men, 34 women) the following measures were taken: psychological distress (beginning and end\\u000a of treatment, and follow

Wiebke Sander; Anne Peters

2009-01-01

385

Habitat Suitability Index Models: Coastal Stocks of Striped Bass  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop estuarine habitat models for coastal stocks of striped bass (Morone saxatilis). Models for five life stages are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) and 1 (optimally suitable habitat) for estuarine areas of the continental United States. Habitat suitability indexes are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service. Guidelines for coastal striped bass model applications and techniques for estimating model variable are described.

Bain, Mark B.; Bain, Jane L.

1982-01-01

386

The Influence of Abnormal Sex Differences in Life Expectancy on National Happiness  

Microsoft Academic Search

Countries with better health, as indexed by life expectancy, score higher on subjective well-being (SWB). It was predicted\\u000a that deviations from the average sex difference in life expectancy (reflecting reproductive competition among males and discrimination\\u000a against females) would be inversely related to happiness. Regression analysis of SWB for 178 countries found that deviations\\u000a from the average sex difference in life

Nigel Barber

2009-01-01

387

Influence of spirituality on cool down reactions, work engagement, and life satisfaction in anthroposophic health care professionals.  

PubMed

This study aimed to analyse whether spirituality is a resource for health care professionals to deal with increasing stress and work burden, specifically to analyse associations between "cool down reactions" (which describe an emotional distancing towards patients and/or reduced engagement as a strategy to protect their own functionality), work burden, and life satisfaction. We specifically focussed on anthroposophic health care professionals because of their unique approach to distinct aspects of spirituality. In a cross-sectional survey using standardized questionnaires, 489 persons were enrolled (66% women, mean age 53?±?10 years, 41% physicians, 12% nurses, and 47% other health care professionals). They scored very high on all measures of spirituality and moderate to low with respect to "cool down reactions." Significant predictors of "cool down reactions" were low work vigor, perceived work burden, alcohol consumption, low life satisfaction, and religious orientation (R (2) = 0.20). In contrast, their life satisfaction was explained best (R (2) = 0.35) by vigor, with further positive influences of being a physician, conscious interactions, and living with a partner on one hand and negative influences of "cool down reactions," work burden, and transcendence convictions on the other hand. Thus, specific aspects of spirituality have only a small influence on anthroposophic health care professionals' "cool down reactions," but might buffer against a loss of vigor and dedication in their work. PMID:25694789

Büssing, Arndt; Lötzke, Désirée; Glöckler, Michaela; Heusser, Peter

2015-01-01

388

The influence of oceanographic fronts and early-life-history traits on connectivity among littoral fish species  

PubMed Central

The spatial distribution of neutral genetic diversity is mainly influenced by barriers to dispersal. The nature of such barriers varies according to the dispersal means and capabilities of the organisms concerned. Although these barriers are often obvious on land, in the ocean they can be more difficult to identify. Determining the relative influence of physical and biotic factors on genetic connectivity remains a major challenge for marine ecologists. Here, we compare gene flow patterns of 7 littoral fish species from 6 families with a range of early-life-history traits sampled at the same geographic locations across common environmental discontinuities in the form of oceanic fronts in the Western Mediterranean. We show that these fronts represent major barriers to gene flow and have a strong influence on the population genetic structure of some fish species. We also found no significant relation between the early-life-history traits most commonly investigated (egg type, pelagic larval duration, and inshore-offshore spawning) and gene flow patterns, suggesting that other life-history factors should deserve attention. The fronts analyzed and the underlying physical mechanisms are not site-specific but common among the oceans, suggesting the generality of our findings. PMID:19164518

Galarza, Juan A.; Carreras-Carbonell, Josep; Macpherson, Enrique; Pascual, Marta; Roques, Severine; Turner, George F.; Rico, Ciro

2009-01-01

389

Life history and environmental influences on population dynamics in sockeye salmon  

E-print Network

salmon (Oncorhynchus nerka) to test general hypotheses for the relative impor- tance of life history populations de saumons rouges (Oncorhynchus nerka) pour vérifier des hypothèses générales concernant l

Reynolds, John D.

390

The Influence of Life History Milestones and Association Networks on Crop-Raiding Behavior in Male African Elephants  

PubMed Central

Factors that influence learning and the spread of behavior in wild animal populations are important for understanding species responses to changing environments and for species conservation. In populations of wildlife species that come into conflict with humans by raiding cultivated crops, simple models of exposure of individual animals to crops do not entirely explain the prevalence of crop raiding behavior. We investigated the influence of life history milestones using age and association patterns on the probability of being a crop raider among wild free ranging male African elephants; we focused on males because female elephants are not known to raid crops in our study population. We examined several features of an elephant association network; network density, community structure and association based on age similarity since they are known to influence the spread of behaviors in a population. We found that older males were more likely to be raiders than younger males, that males were more likely to be raiders when their closest associates were also raiders, and that males were more likely to be raiders when their second closest associates were raiders older than them. The male association network had sparse associations, a tendency for individuals similar in age and raiding status to associate, and a strong community structure. However, raiders were randomly distributed between communities. These features of the elephant association network may limit the spread of raiding behavior and likely determine the prevalence of raiding behavior in elephant populations. Our results suggest that social learning has a major influence on the acquisition of raiding behavior in younger males whereas life history factors are important drivers of raiding behavior in older males. Further, both life-history and network patterns may influence the acquisition and spread of complex behaviors in animal populations and provide insight on managing human-wildlife conflict. PMID:22347468

Chiyo, Patrick I.; Moss, Cynthia J.; Alberts, Susan C.

2012-01-01

391

Survival of freezing by hydrated tardigrades inhabiting terrestrial and freshwater habitats.  

PubMed

The seasonality and unpredictability of environmental conditions at high altitudes and latitudes govern the life cycle patterns of organisms, giving rise to stresses that cause death or development of specific adaptations. Ice formation is a major variable affecting the survival of both freshwater fauna and fauna inhabiting lichens, mosses and leaf litter. Tardigrades occupy a wide range of niches in marine, freshwater and terrestrial environments. The highest number of species is found in terrestrial habitats thanks to their ability to enter anhydrobiosis and cryobiosis. The cryobiotic ability of tardigrade species from polar regions is well known. Consequently, we focused our research on the ability to survive freezing in the active hydrated state using seven tardigrade species differing in phylogenetic position and collected at various altitudes and from different habitats in a temperate area. Specimens were cooled at different cooling rates (from 0.31° C min(-1) to 3.26° C min(-1)). Even though the final survival and the time required by animals to recover to active life were both inversely related to the cooling rate, highly significant interspecific differences were found. Species survival ability ranged from excellent to none. Species living in xeric habitats withstood freezing better than those living in hygrophilous habitats, while true limnic species did not exhibit any cryobiotic ability. The ability to withstand freezing seems linked to the anhydrobiotic ability. The differences in cryptobiotic performance among tardigrade species seem more influenced by selective pressures linked to local adaptation to habitat characteristics than by phylogenetic relationships. PMID:21429723

Guidetti, Roberto; Altiero, Tiziana; Bertolani, Roberto; Grazioso, Pasqualina; Rebecchi, Lorena

2011-04-01

392

The Habitat Connection.  

ERIC Educational Resources Information Center

Consists of activities which address the causes of habitat destruction and the effects of habitat loss on animals and plants. Identifies habitat loss as the major reason for the endangerment and extinction of plant and animal species. (ML)

Naturescope, 1987

1987-01-01

393

Aquatic Habitats  

NSDL National Science Digital Library

This lesson plan will help students to understand that the way a community disposes of its wastewater may negatively affect local aquatic habitats, that it is possible to find wastewater-disposal methods that do not pollute, and that both governments and citizens can take action to ensure that waste water will be disposed of in a way that is not destructive. As part of the lesson, students will discuss the definition of "wastewater", how it is disposed of, invite a guest speaker to class, and write proposals to local government officials either suggesting improvements or commending their current procedures. Adaptations for older students, discussion questions, an evaluation rubric, extension activities, suggested readings, a vocabulary, and links to related sites accompany the lesson.

Betsy Hedberg

2003-01-01

394

Influence of life history strategies on sensitivity, population growth and response to climate for sympatric alpine birds  

PubMed Central

Background The life history strategy of a species can influence how populations of that species respond to environmental variation. In this study, we used a matrix modeling approach to examine how life history differences among sympatric rock and white-tailed ptarmigan affect the influence of demographic rates on population growth (?) and the potential response to a changing climate. Rock ptarmigan have a slower life history strategy than white-tailed ptarmigan in the study region with lower annual reproductive effort but higher adult survival. Results Based on data from a 5-year field study, deterministic estimates of ? indicated that populations were stable for rock ptarmigan (??=?1.01), but declining for white-tailed ptarmigan (??=?0.96). The demographic rates with the highest elasticity for rock ptarmigan were the survival of after-second year females, followed by juvenile survival and success of the first nest. For white-tailed ptarmigan, juvenile survival had the highest elasticity followed by success of the first nest and survival of second-year females. Incorporating stochasticity into the demographic rates led to a 2 and 4% drop in ? for rock and white-tailed ptarmigan respectively. Using data from the first three years we also found that population growth rates of both species were depressed following an increased frequency of severe years, but less so for rock ptarmigan which showed greater resilience under these conditions. Conclusions Our results provide evidence that populations of closely related species can vary in their response to environmental change as a consequence of life history differences. Rock ptarmigan, with a slower life history, are more responsive to demographic rates that influence survival and older life stages but this response is tempered by the extent of variability in each of the rates. Thus, predictions need to consider both aspects in modeling population response to a varying climate. Juvenile survival was a highly influential rate for both species, but the period from independence to first breeding is a poorly understood stage for many bird species. Additional study on juvenile survival, the influence of density dependence and the effects of predators as the mechanism driving survival-reproduction tradeoffs are all areas requiring further study. PMID:22747571

2012-01-01

395

The Influence of Major Life Events on Economic Attitudes in a World of Gene-Environment Interplay  

PubMed Central

The role of “genes” on political attitudes has gained attention across disciplines. However, person-specific experiences have yet to be incorporated into models that consider genetic influences. Relying on a gene-environment interplay approach, this study explicates how life-events, such as losing one’s job or suffering a financial loss, influence economic policy attitudes. The results indicate genetic and environmental variance on support for unions, immigration, capitalism, socialism and property tax is moderated by financial risks. Changes in the magnitude of genetic influences, however, are temporary. After two years, the phenotypic effects of the life events remain on most attitudes, but changes in the sources of individual differences do not. Univariate twin models that estimate the independent contributions of genes and environment on the variation of attitudes appear to provide robust baseline indicators of sources of individual differences. These estimates, however, are not event or day specific. In this way, genetic influences add stability, while environment cues change, and this process is continually updated. PMID:24860199

Hatemi, Peter K.

2014-01-01

396

Influence of herbivores on a perennial plant: variation with life history stage and herbivore species  

Microsoft Academic Search

Herbivores have diverse impacts on their host plants, potentially altering survival, growth, fecundity, and other aspects of plant performance. Especially for longer-lived plant species, the effects of a single herbivore species can vary markedly throughout the life of the host plant. In addition, the effects of herbivory during any given life history stage of a host plant may also vary

Peter J. Warner; Hall J. Cushman

2002-01-01

397

[The influence of attention-deficit hyperactivity disorder on quality of life: case reports].  

PubMed

Recently the concept of Quality of Life has gained increasing importance in Psychiatry. Studies focusing on how much attention-deficit hyperactivity disorder (ADHD) - one of the most prevalent psychiatric disorders among children - affects the every day life found that children with ADHD had significantly lower Quality of Life than healthy controls or children with other psychiatric or physical disorders. In the current paper we present the case of two boys with ADHD and their families. These cases demonstrate that adequate treatment of the symptoms of ADHD can improve Quality of Life of the patients and their families, moreover, different life events can worsen the symptoms of ADHD. Professionals should ensure flexible treatment, which conforms to the above described processes. PMID:24978052

Dallos, Gyöngyvér; Balázs, Judit

2014-06-01

398

Early-life dietary spray-dried plasma influences immunological and intestinal injury responses to later-life Salmonella typhimurium challenge.  

PubMed

Increasing evidence supports the concept that early-life environmental influences, including nutrition and stress, have an impact on long-term health outcomes and disease susceptibility. The objective of the present study was to determine whether dietary spray-dried plasma (SDP), fed during the first 2 weeks post-weaning (PW), influences subsequent immunological and intestinal injury responses to Salmonella typhimurium challenge. A total of thirty-two piglets (age 16-17 d) were weaned onto nursery diets containing 0, 2·5 % SDP (fed for 7 d PW) or 5 % SDP (fed for 14 d PW), and were then fed control diets (without SDP), for the remainder of the experiment. At 34 d PW (age 50 d), pigs were challenged with 3 × 109 colony-forming units of S. typhimurium. A control group (non-challenged) that was fed 0 % SDP in the nursery was included. At 2 d post-challenge, the distal ileum was harvested for the measurement of inflammatory, histological and intestinal physiological parameters. S. typhimurium challenge induced elevated ileal histological scores, myeloperoxidase (MPO), IL-8 and TNF, and increased intestinal permeability (indicated by reduced transepithelial voltage (potential difference) and elevated 4 kDa fluorescein isothiocyanate dextran (FD4) flux rates). Compared with S. typhimurium-challenged controls (0 % SDP), pigs fed the 5 % SDP-14 d diet exhibited reduced ileal histological scores, MPO levels, IL-8 levels and FD4 flux rates. Pigs fed the 5 % SDP-14 d nursery diet exhibited increased levels of plasma and ileal TNF-? in response to the challenge, compared with the other treatments. These results indicate that inclusion of SDP in PW diets can have an influence on subsequent immunological and intestinal injury responses induced by later-life S. typhimurium challenge. PMID:25671331

Boyer, P E; D'Costa, S; Edwards, L L; Milloway, M; Susick, E; Borst, L B; Thakur, S; Campbell, J M; Crenshaw, J D; Polo, J; Moeser, A J

2015-03-01

399

Fragmentation of habitats used by neotropical migratory birds in Southern Appalachians and the neotropics  

SciTech Connect

Recent declines in North American breeding populations have sparked great concern over the effects of habitat fragmentation. Neotropical migrant birds use and are influenced by two biomes during a single life span. Yet assessment of the relative importance of changes in tropical wintering areas versus temperate breeding areas is complicated by regional variation in rates and extent of habitat change. Landscape-level measurements of forest fragmentation derived from remotely-sensed data provide a means to compare the patterns of habitat modification on the wintering and breeding grounds of migrant birds. This study quantifies patterns of forest fragmentation in the Southern Appalachian Mountains and tropical Amazon and relates these patterns to the resource needs of neotropical migrant birds. Study sites were selected from remotely-sensed images to represent a range of forest fragmentation (highly fragmented landscape to continuous forest).

Pearson, S.M.; Dale, V.H. [Oak Ridge National Lab., TN (United States); Offerman, H.L. [Oak Ridge National Lab., TN (United States)]|[Oak Ridge Associated Universities, Inc., TN (United States)

1993-12-31

400

Habitat characteristics affecting fish assemblages on a Hawaiian coral reef  

Microsoft Academic Search

Habitat characteristics of a reef were examined as potential influences on fish assemblage structure, using underwater visual census to estimate numbers and biomass of all fishes visible on 42 benthic transects and making quantitative measurements of 13 variables of the corresponding physical habitat and sessile biota. Fish assemblages in the diverse set of benthic habitats were grouped by detrended correspondence

Alan M Friedlander; James D Parrish

1998-01-01

401

RESEARCH IN SUPPORT OF CRITERIA FOR HABITAT ALTERATIONS  

EPA Science Inventory

Many anthropogenic activities exert their influence on fish, shellfish and aquatic-dependent wildlife by affecting habitats. In fact, habitat alteration is one of the most important contributors to declines in ecological resources in North America. Habitat loss and degradation ar...

402

Toward an ecological synthesis: a case for habitat selection  

Microsoft Academic Search

Habitat selection, and its associated density and frequency-dependent evolution, has a profound influence on such vital phenomena as population regulation, species interactions, the assembly of ecological communities, and the origin and maintenance of biodiversity. Different strategies of habitat selection, and their importance in ecology and evolution, can often be revealed simply by plots of density in adjacent habitats. For individual

Douglas W. Morris

2003-01-01

403

Influence of habitat and climate variables on arbuscular mycorrhizal fungus community distribution, as revealed by a case study of facultative plant epiphytism under semiarid conditions.  

PubMed

In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats. PMID:24038687

Torrecillas, E; Torres, P; Alguacil, M M; Querejeta, J I; Roldán, A

2013-12-01

404

Influence of the Qinghai-Tibetan railway on the habitat selection of wild animals, using satellite data and satellite-based ARGOS system data  

NASA Astrophysics Data System (ADS)

The Qinghai-Tibet Railway (QTR) was in trial operation since 1 July 2006, is the world's highest-elevation railway and the longest highland railway, extending over 1956