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1

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.

2

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

3

Potential Habitats for Exotic Life Within the Life Supporting Zone  

NASA Astrophysics Data System (ADS)

Questions like "Are we alone in the universe?", "How unique is Earth as a planet?" or "How unique is water-based life in the universe?" still are nowhere near of being answered. In recent years, discussions on these topics are more and more influenced by questions whether water is really the only possible solvent, or which conditions are necessary for life to evolve in planetary habitats. A change in our present geocentric mindset on the existence of life is required, in order to address these new questions [see also 1]. In May 2009 a new research platform at the University of Vienna was initiated in order to contribute to the solution of these questions. One task is to find essential biomarkers relevant to the problem of the detection of exotic life. In this context exotic life means: life, which is not necessarily based on a double bond between carbon and oxygen (C=O) and not on water as the only possible solvent. At present little is known about metabolistic systems, which are not based on C=O or on metabolisms which are operative in alternative solvents and a high effort of future laboratory work is necessary to open this window for looking for exotic life. To address the whole spectrum of life the concept of a general life supporting zone is introduced in order to extend the classical habitable zone (which is based on liquid water on a planetary surface, [2]). The life supporting zone of a planetary system is composed of different single "habitable zones" for the liquid phases of specific solvents and composites between water and other solvents. Besides exoplanetary systems which seem to be the most promising place for exotic life in our present understanding, some potential places could also exist within our Solar System and habitats like the subsurface of Enceladus, liquid ethane/methane lakes on Titan or habitable niches in the Venus atmosphere will also be taken into account. A preliminary list of appropriate solvents and their abundances in the Solar System and beyond have been compiled. Dynamical investigations (related to the interior of superearths), but also heat transport regimes and potential cycles with exotic solvents as well as tidal heating processes and their influence on the thermal regime of the planets will help to define the regions of potential exotic life more precisely. Atmospheric and subsurface cycles which can take place in such habitats as well as cloud and droplet formation with and without cloud nuclei cores will further extend our knowledge on mechanisms relevant for the stability of these systems. Finally the question of suitable biomarkers, which can enable the observation of exotic habitats and their potential life forms will be considered in the research platform. In this context a special topic is also the bandwidth of photosynthesis: how is the influence of different atmospheric gases and what are the environment conditions for the chemical reactions of photosynthesis? First preliminary results for the life supporting zones of selected planetary systems will be presented. References: [1] NRC (National Research Council)(2007) The Limits of Organic Life in Planetary Systems, National Academies Press, Washington, DC 20001, ISBN 978-0-309-10484-5. [2] Kasting, J.F., Whitmore D.P. and Reynolds R.T. (1993) Icarus, 101, 109-128.

Leitner, Johannes J.; Firneis, Maria G.; Hitzenberger, Regina

2010-05-01

4

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

5

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

6

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

7

The habitat and nature of early life.  

PubMed

Earth is over 4,500 million years old. Massive bombardment of the planet took place for the first 500-700 million years, and the largest impacts would have been capable of sterilizing the planet. Probably until 4,000 million years ago or later, occasional impacts might have heated the ocean over 100 degrees C. Life on Earth dates from before about 3,800 million years ago, and is likely to have gone through one or more hot-ocean 'bottlenecks'. Only hyperthermophiles (organisms optimally living in water at 80-110 degrees C) would have survived. It is possible that early life diversified near hydrothermal vents, but hypotheses that life first occupied other pre-bottleneck habitats are tenable (including transfer from Mars on ejecta from impacts there). Early hyperthermophile life, probably near hydrothermal systems, may have been non-photosynthetic, and many housekeeping proteins and biochemical processes may have an original hydrothermal heritage. The development of anoxygenic and then oxygenic photosynthesis would have allowed life to escape the hydrothermal setting. By about 3,500 million years ago, most of the principal biochemical pathways that sustain the modern biosphere had evolved, and were global in scope. PMID:11234022

Nisbet, E G; Sleep, N H

2001-02-22

8

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 shown to be correlated with environmental variables. It appears that salmonids have adapted life history and other life history characteristics) in as little as 13 generations. Quinn and Unwin (1993) showed

9

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

10

Effects of Life History Strategy on Fish Distribution and Use of Estuarine Salt Marsh and Shallow-Water Flat Habitats  

Microsoft Academic Search

To assess the potential for habitat isolation effects on estuarine nekton, we used two species with different dispersal abilities\\u000a and life history strategies, mummichog (Fundulus heteroclitus) and pinfish (Lagodon rhomboides) to examine: (1) distribution trends among estuarine shallow-water flat and various intertidal salt marsh habitats and (2)\\u000a the influence of salt marsh habitat size and isolation. Collections were conducted using

David L. Meyer; Martin H. Posey

2009-01-01

11

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

12

The habitat and nature of early life  

Microsoft Academic Search

Earth is over 4,500 million years old. Massive bombardment of the planet took place for the first 500–700 million years, and the largest impacts would have been capable of sterilizing the planet. Probably until 4,000 million years ago or later, occasional impacts might have heated the ocean over 100 °C. Life on Earth dates from before about 3,800 million years

E. G. Nisbet; N. H. Sleep

2001-01-01

13

Developing closed life support systems for large space habitats  

NASA Technical Reports Server (NTRS)

In anticipation of possible large-scale, long-duration space missions which may be conducted in the future, NASA has begun to investigate the research and technology development requirements to create life support systems for large space habitats. An analysis suggests the feasibility of a regeneration of food in missions which exceed four years duration. Regeneration of food in space may be justified for missions of shorter duration when large crews must be supported at remote sites such as lunar bases and space manufacturing facilities. It is thought that biological components consisting principally of traditional crop and livestock species will prove to be the most acceptable means of closing the food cycle. A description is presented of the preliminary results of a study of potential biological components for large space habitats. Attention is given to controlled ecosystems, Russian life support system research, controlled-environment agriculture, and the social aspects of the life-support system.

Phillips, J. M.; Harlan, A. D.; Krumhar, K. C.

1978-01-01

14

Appendix 67 A Review of Bull Trout Life-History and Habitat Use in Relation to  

E-print Network

and Improvement Opportunities #12;A REVIEW OF BULL TROUT (SALVELINUS CONFLUENTUS) LIFE-HISTORY AND HABITAT USE 1996 #12;#12;A Review of Bull Trout (Salvelinus confluentus) Life-history and Habitat Use in Relation., and J. S. Baxter. 1996. A review of bull trout (Salvelinus confluentus) life-history and habitat use

15

Management and Conservation Influence of Habitat Features and Hunter  

E-print Network

Management and Conservation Influence of Habitat Features and Hunter Behavior on White-Tailed Deer white-tailed deer (Odocoileus virginianus) hunting on a high deer density island where hunting, management tool, Odocoileus virginianus, white-tailed deer. In recent decades, several regions including

Laval, Université

16

The Virtual Habitat - a tool for Life Support Systems optimization  

NASA Astrophysics Data System (ADS)

In the course of designing Life Support Systems (LSS) a great multitude of concepts for and various combinations of subsystems and components are developed. In order to find an optimal LSS solution, thus the right combination of subsystems, the parameters for the definition of the optimization itself have to be determined. The often times used Equivalent Systems Mass (ESM) based trade study approach for life support systems is well suited for phase A conceptual design evaluations. The ESM approach allows an efficient evaluation of LSS on a component or subsystem level. The necessary next step in the process is the design, evaluation and optimization of the LSS on a system level. For the system level LSS design a classic ESM-based trade study seems not to be able to provide the information that is necessary to evaluate the concept correctly. Important decisive criteria such as system stability, controllability and effectiveness are not represented in the ESM approach. These parameters directly and decisively impact the scientific efficiency of the crew, thereby the mission in total. Thus, for system level optimization these criteria must be included alongside the ESM in a new integral optimization method. In order to be able to apply such an integral criterion dynamic modeling of most involved LSS subsystems, especially of the human crew, is necessary. Only then the required information about the efficiency of the LSS, over time, e.g. the systems stability, becomes available. In an effort to establish a dynamic simulation environment for habitats in extreme environmental conditions, the "Virtual Habitat" tool is being developed by the Human Spaceflight Group of the Technische Universit¨t M¨nchen (TUM). The paper discussed here presents the concept of a u the virtual habitat simulation. It discusses in what way the simulation tool enables a prediction of system characteristics and required information demanded by an integral optimization criterion. In general the Virtual Habitat consists of four main modules each of which is subdivided into further, more detailed sub-modules. The four main modules of the simulation are the following: · Closed Environment Module (CEM)- monitoring of compounds in a closed environment · Crew Module (CM) - dynamic human simulation · Plant Module (PM) - dynamic plant simulation · P/C systems module (PCSM) - library of dynamic P/C subsystems The paper describes the character of each of the modules introducing the first results, which will be the first version of the metabolism, muscle and cardiovascular sub-modules of the crew module. In addition a dynamic closed environment module and the first dynamic plant model are presented and discussed. Further the modularity strategy and interfaceability of the submodels of the Virtual Habitat are discussed highlighting the resulting model limitations. Finally in the paper an outlook is given on the tasks remaining before the virtual habitat can be used to optimize life support systems on a system level. Among others the question of model correlation with existing simulations and data will be addressed.

Czupalla, Markus; Dirlich, Thomas; Harder, Jan; Pfeiffer, Matthias

17

Influence of habitat degradation on fish replenishment  

Microsoft Academic Search

Temperature-induced coral bleaching is a major threat to the biodiversity of coral reef ecosystems. While reductions in species\\u000a diversity and abundance of fish communities have been documented following coral bleaching, the mechanisms that underlie these\\u000a changes are poorly understood. The present study examined the impacts of coral bleaching on the early life-history processes\\u000a of coral reef fishes. Daily monitoring of

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

2010-01-01

18

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

19

Influence of Habitat Structure on Pomacentrus sulfureus, A Western Indian Ocean Reef Fish  

Microsoft Academic Search

The influence of habitat on the distribution and abundance of Pomacentrus sulfureus was investigated on coral reefs in Zanzibar. Fish censuses were conducted using the simultaneous belt-transect method and substrate data were gathered using a point-base method. Densities of juvenile and adult P. sulfureus were examined in relation to habitat composition and structure. The influence of habitat structure on coral

Kajsa C. Bergman; Marcus C. Öhman; Sara Svensson

2000-01-01

20

Demographics, Life Cycle, Habitat Characterization and Transplant Methods for the Endangered Orchid, Spiranthes parksii Correll  

E-print Network

an estimated 379 S. parksii individuals and 44.7 ha of its habitat. Research has been funded to mitigate for this loss and includes documenting demographics, life cycle, local and landscape habitat, and on-site transplantation of S. parksii. Results found...

Hammons, Jonathan R.

2010-01-14

21

The Influence of Spawning Habitat on Natural Reproduction of Muskellunge in Wisconsin  

Microsoft Academic Search

Many of Wisconsin's native populations of muskellunge Esox masquinongy exhibit declining reproductive success and failing natural recruitment. As a result, self-sustaining populations of muskellunge are diminishing. This study focused on spawning habitat factors that influence egg development and survival and, consequently, the reproductive success of muskellunge. Muskellunge spawning habitat characteristics in lakes with self-sustaining populations were compared with spawning habitat

Sarah A. Zorn; Terry L. Margenau; James S. Diana; Clayton J. Edwards

1998-01-01

22

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

E-print Network

Prioritizing winter habitat quality for greater sage-grouse in a landscape influenced by energy, and F. C. Blomquist. 2014. Prioritizing winter habitat quality for Greater Sage-Grouse in a landscape models as a framework to quantify habitat value for wintering female greater sage-grouse (Centrocercus

Beck, Jeffrey L.

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

Impact of crop production on air quality in life support dynamics in closed habitats  

Microsoft Academic Search

Interest in human-designed closed habitats - where the substances needed for human life support are continuously regenerated from waste products - is growing, as apparent from the National Aeronautics and Space Administration's Closed Ecological Life Support Systems Program, the Soviet Union's Bios experiments, and the Biosphere II Project in Arizona. Nuclear-powered bases on the moon and Mars will have food-growing

Volk

1987-01-01

25

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

PubMed Central

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

2013-01-01

26

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

27

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

28

Habitat: importance, destruction, & Habitat: importance, destruction, &  

E-print Network

Habitat: importance, destruction, & evaluation #12;Habitat: importance, destruction, & evaluation Organisms Habitat People Taxonomy Ecology Population dynamics Life history Stocking Introductions Population Biodiversity Genetics Restoration #12;What is habitat for fish? · Habitat for fish includes all of the physical

Limburg, Karin E.

29

Evaluating habitat effects on population status: influence of habitat restoration on spring-run Chinook salmon  

Microsoft Academic Search

SUMMARY 1. A key element of conservation planning is the extremely challenging task of estimating the likely effect of restoration actions on population status. To compare the relative benefits of typical habitat restoration actions on Pacific salmon (Oncorhynchus spp.), we modelled the response of an endangered Columbia River Chinook salmon (O. tshawytscha) population to changes in habitat characteristics either targeted

JON M. H ONEA; J EFFREY; C. J ORGENSEN; M ICHELLE M. M CCLURE; T HOMAS

2009-01-01

30

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

31

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

32

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

33

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

34

Idea Habitats: How the Prevalence of Environmental Cues Influences the Success of Ideas  

ERIC Educational Resources Information Center

We investigate 1 factor that influences the success of ideas or cultural representations by proposing that they have a habitat, that is, a set of environmental cues that encourages people to recall and transmit them. We test 2 hypotheses: (a) fluctuation: the success of an idea will vary over time with fluctuations in its habitat, and (b)…

Berger, Jonah A.; Heath, Chip

2005-01-01

35

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

36

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

37

The Effects of the Wildlife Habitat Evaluation Program on Targeted Life Skills  

ERIC Educational Resources Information Center

Does participation in the Wildlife Habitat Evaluation Program (WHEP) help develop life skills? 4-H members and coaches who participated in the National WHEP Contest between the years 2003-2005 and 2007-2009 were asked to complete an evaluation at the end of each contest. A portion of the evaluation asked participants and coaches to determine if…

Allen, Kevin; Elmore, R. Dwayne

2012-01-01

38

Habitat Associations, Life History and Diet of the Sabine Shiner Notropis sabinae  

E-print Network

Habitat Associations, Life History and Diet of the Sabine Shiner Notropis sabinae in an East Texas University-San Marcos, San Marcos 78666 ABSTRACT.--We examined aspects of the ecology of Notropis sabinae east Texas streams from November 2001 through October 2002. Notropis sabinae exhibited no strong

Aspbury, Andrea S. - Department of Biology, Texas State University

39

An Evaluation of the Relative Influence of Habitat Complexity and Habitat Stability on Fish Assemblage Structure in Unregulated and Regulated Reaches of a Large Southeastern Warmwater Stream  

Microsoft Academic Search

River regulation and development are the foremost problems threatening lotic fishes and other aquatic biota in the United States. The operation of hydroelectric facilities can influence both habitat availability and environmental stability in downstream reaches. We evaluated the relative influence of habitat complexity and environmental stability on fish assemblage structure at unregulated and hydropower-regulated reaches of the Flint River in

Colin P. Shea; James T. Peterson

2007-01-01

40

Relative embryo length as an adaptation to habitat and life cycle in Apiaceae.  

PubMed

• The factors driving the evolution of the relative embryo length in Apiaceae were examined. We tested the hypothesis that seeds with large relative embryo length, because of more rapid germination, are beneficial in dry and open habitats and for short-lived species. We also analyzed to what extent delayed germination as a result of embryo growth can be considered a dormancy mechanism. • Hypotheses were tested by correlating the relative embryo length with other plant traits, habitat and climatic variables. The adaptive nature of the relative embryo length was determined by comparing the performance of a pure drift, Brownian motion (BM) model of trait evolution with that of a selection-inertia, Ornstein-Uhlenbeck (OU) model. • A positive correlation of the relative embryo length with germination speed and negative correlations with the amount of habitat shade, longevity and precipitation were found. An OU model, in which the evolution of longer embryos corresponded to a transition to habitats of high light, or to a short life cycle, outperformed significantly a BM model. • The results indicated that the relative embryo length may have evolved as an adaptation to habitat and life cycle, whereas dormancy was mainly related to temperature at the sampling sites. PMID:22621412

Vandelook, Filip; Janssens, Steven B; Probert, Robin J

2012-07-01

41

Controlled ecological life support systems for space habitats  

NASA Technical Reports Server (NTRS)

The development of regenerative life support systems to meet the physiological requirements of humans in space is described. A review of previous research on regenerative systems is presented. NASA's Controlled Ecological Life Support System (CELSS) program, which is to develop an environment for a human space crew, is discussed. The table of physiological requirements of an average human and the logical system approach to planning a closed system created by Spurlock and Modell (1976, 1978) are examined. The weight of food and oxygen with respect to lift-off weight is investigated. The creation of the proper atmosphere for space, by balancing all the necessary parameters is studied. The need for a mineral and fluid balance and methods of maintaining it are analyzed. The required cooperation between physicians, physiologists, and nutritionists for the success of the CELSS program is discussed.

Buchanan, P.

1984-01-01

42

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

43

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

44

Early Archaean collapse basins, a habitat for early bacterial life.  

NASA Astrophysics Data System (ADS)

For a better definition of the sedimentary environment in which early life may have flourished during the early Archaean, understanding of the basin geometry in terms of shape, depth, and fill is a prerequisite. The basin fill is the easiest to approach, namely from the well exposed, low-grade metamorphic 3.4 - 3.5 Ga rock successions in the greenstone belts of the east Pilbara (Coppin Gap Greenstone Belt and North Pole Dome) in West Australia and of the Barberton Greenstone Belt (Buck Ridge volcano-sedimentary complex) in South Africa. They consist of mafic to ultramafic volcanic rocks, largely pillow basalts, with distinct intercalations of intermediate to felsic intrusive and volcanic rocks and of silicious sediments. The, partly volcaniclastic, silicious sediments of the Buck Ridge and North Pole volcano-sedimentary complexes form a regressive-transgressive sequence. They were deposited close to base level, and experienced occasional emersion. Both North Pole Chert and the chert of the Kittys Gap volcano-sedimentary complex in the Coppin Gap Greenstone Belt preserve the flat-and-channel architecture of a shallow tidal environment. Thickness and facies distribution appear to be genetically linked to systems, i.e. arrays, of syn-depositionally active, extensional faults. Structures at the rear, front and bottoms of these fault arrays, and the fault vergence from the basin margin towards the centre characterize the basins as due to surficial crustal collapse. Observations in the Pilbara craton point to a non-linear plan view and persistence for the basin-defining fault patterns over up to 50 Ma, during which several of these fault arrays became superposed. The faults linked high-crustal level felsic intrusions within the overall mafic rock suite via porphyry pipes, black chert veins and inferred hydrothermal circulations with the overlying felsic lavas, and more importantly, with the cherty sediments. Where such veins surfaced, high-energy breccias, and in the case of the North Pole Chert huge barite growths, are juxtaposed with the otherwise generally low-energy sediments. Such localities are interpreted as sites of hydrothermal vents. Within this large-scale geological context, many environments on the micro-scale were habitable for life, such as hydrothermal vents and their vicinities, volcanic rock surfaces, subsurface sediments and sediment surfaces. These early collapse basins, hosting this bacterial life, are only partially comparable to Earthly analogues. A resemblance with Venus' coronae and the chaos terranes on Mars is suggested. This study forms part of an international project on Earth's Earliest Sedimentary Basins, supported by the Dutch Foundation Dr. Schürmannfonds. 2

Nijman, W.

45

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.

Millette, Katie L; Keyghobadi, Nusha

2015-01-01

46

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

47

Vacant habitats in the Universe.  

PubMed

The search for life on other planets usually makes the assumption that where there is a habitat, it will contain life. On the present-day Earth, uninhabited habitats (or vacant habitats) are rare, but might occur, for example, in subsurface oils or impact craters that have been thermally sterilized in the past. Beyond Earth, vacant habitats might similarly exist on inhabited planets or on uninhabited planets, for example on a habitable planet where life never originated. The hypothesis that vacant habitats are abundant in the Universe is testable by studying other planets. In this review, I discuss how the study of vacant habitats might ultimately inform an understanding of how life has influenced geochemical conditions on Earth. PMID:21146249

Cockell, Charles S

2011-02-01

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

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

50

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

51

URBANIZATION AND SPIDER DIVERSITY: INFLUENCES OF HUMAN MODIFICATION OF HABITAT STRUCTURE AND PRODUCTIVITY  

Microsoft Academic Search

As a part of the Central Arizona-Phoenix Long-Term Ecological Research project, we determined how land-use alteration influenced spider and harvestman diversity. We sampled spiders in six habitat types (desert parks, urban desert remnants, industrial, agricultural, xeric- and mesic-residential yards) and tested how habitat type and productivity affected spider diversity and abundance. As expected, agricultural fields and mesic yards were more

E. Shochat; W. L. Stefanov; M. E. A. Whitehouse; S. H. Faeth

2004-01-01

52

Urbanization and Spider Diversity: Influences of Human Modification of Habitat Structure and Productivity  

Microsoft Academic Search

As a part of the Central Arizona–Phoenix Long-Term Ecological Research project, we determined how land-use alteration influenced\\u000a spider and harvestman diversity. We sampled spiders in six habitat types (desert parks, urban desert remnants, industrial,\\u000a agricultural, xeric- and mesic-residential yards) and tested how habitat type and productivity affected spider diversity and\\u000a abundance. As expected, agricultural fields and mesic yards were more

E. Shochat; W. L. Stefanov; M. E. A. Whitehouse; S. H. Faeth

53

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

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

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

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

Life-cycle evolution as response to diverse lake habitats in Paleozoic amphibians.  

PubMed

The evolution of life cycles forms the subject of numerous studies on extant organisms, but is rarely documented in the fossil record. Here, I analyze patterns of development in time-averaged samples of late Carboniferous and early Permian amphibians, and compare them to paleoecological patterns derived from the same deposits located within a large sedimentary basin (Saar-Nahe, Germany). In 300-297 million years (myr) old Sclerocephalus haeuseri (1-1.7 m), adult size, morphology, and the course of ontogeny varied with respect to the habitats in which the species existed. These differences are best exemplified by ontogenetic trajectories, which reveal a full range of modifications correlating with environmental parameters (lake properties, food resources, competitors). In a 2- to 3-myr-long interval, six different lake habitats were inhabited by this species, which responded to changes by modification of growth rate, adult size, developmental sequence, skeletal features, prey preference, and relative degree of terrestriality. PMID:19619224

Schoch, Rainer R

2009-10-01

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

Agricultural effects on amphibian parasitism: importance of general habitat perturbations and parasite life cycles.  

PubMed

Agricultural activity can alter host-parasite interactions through associated contaminants and habitat perturbations. It is critical to determine whether agricultural effects are widespread or limited to specific types of agriculture. We examined influences of soybean agriculture on trematode parasitism of larval amphibians (grey tree frogs; Hyla versicolor) to assess the potential effects of a commonly applied pesticide (glyphosate) and landscape factors relative to previous field studies focusing on the herbicide atrazine. Overall, trematode parasite infection did not differ between soybean-adjacent and nonagricultural ponds (87.7% and 72.6% mean infection, respectively). However, host-generalist echinostome species were more common in tadpoles from soybean-associated ponds (86.3% mean infection versus 36.2% in nonagricultural ponds) as well as sites with large or short average distances to forest cover and roads, respectively. In contrast, the occurrence of a host-specialist (Alaria sp.) group was greater in nonagricultural ponds (50.3% mean infection versus 9.8% in soybean-associated ponds) and increased with shorter distances to the closest forest patch and smaller average forest distance. Because glyphosate was not detected at any site and landscape influences were parasite-specific, we suggest that agriculture may have broad effects on wildlife diseases through habitat alterations that affect pathogen transmission via host habitat suitability. Notably, nonagricultural ponds had a lower mean distance to the nearest forest patch and lower mean forest distance compared with soybean-adjacent ponds. As a result, we emphasize the need for wider investigations of habitat perturbations generally associated with agriculture for host-pathogen interactions, and consequently, wildlife conservation and management strategies. PMID:23060494

Koprivnikar, Janet; Redfern, Julia C

2012-10-01

60

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

61

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

E-print Network

of Body Condition in a Northern White-Tailed Deer Population ANOUK SIMARD,1,2 NSERC Industrial Research influenced white-tailed deer (Odocoileus virginianus) body condition during the breeding period. We detailed investigated how spatial and annual variation in habitat composition, deer density, and vegetation productivity

Laval, Université

62

White-tailed Deer Habitat Use and Movements Integrated with Factors Influencing Vehicle  

E-print Network

1/9/13 1 White-tailed Deer Habitat Use and Movements Integrated with Factors Influencing and compare white-tailed deer reproductive efforts during pre-, peak, and post-rut periods 2. Investigate and compare white-tailed deer reproductive efforts during pre-, peak, and post-rut periods 2. Investigate

Gray, Matthew

63

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

64

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: ...

65

Local Abundance Patterns of Noctuid Moths in Olive Orchards: Life-History Traits, Distribution Type and Habitat Interactions  

PubMed Central

Local species abundance is related to range size, habitat characteristics, distribution type, body size, and life-history variables. In general, habitat generalists and polyphagous species are more abundant in broad geographical areas. Underlying this, local abundance may be explained from the interactions between life-history traits, chorological pattern, and the local habitat characteristics. The relationship within taxa between life-history traits, distribution area, habitat characteristics, and local abundance of the noctuid moth (Lepidoptera: Noctuidae) assemblage in an olive orchard, one of the most important agro-ecosystems in the Mediterranean basin, was analyzed. A total of 66 species were detected over three years of year-round weekly samplings using the light-trap method. The life-history traits examined and the distribution type were found to be related to the habitat-species association, but none of the biological strategies defined from the association to the different habitats were linked with abundance. In contrast to general patterns, dispersal ability and number of generations per year explained differences in abundance. The relationships were positive, with opportunistic taxa that have high mobility and several generations being locally more abundant. In addition, when the effect of migrant species was removed, the distribution type explained abundance differences, with Mediterranean taxa (whose baricenter is closer to the studied area) being more abundant. PMID:21529251

Pérez-Guerrero, Sergio; Redondo, Alberto José; Yela, José Luis

2011-01-01

66

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

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

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

70

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

71

Where Wolves Kill Moose: The Influence of Prey Life History Dynamics on the Landscape Ecology of Predation  

PubMed Central

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

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

MWSA's physical habitat approach - combining knowledge of habitat requirements with mechanisms of geomorphic and anthropogenic influence on stream channel form  

EPA Science Inventory

Effective environmental policy decisions benefit from stream habitat information that is accurate, precise, and relevant. The recent National Wadeable Streams Assessment (NWSA) carried out by the U.S. EPA required physical habitat information sufficiently comprehensive to facilit...

74

The influence of spatial scale and habitat arrangement on diel patterns of habitat use by two lowland river fishes  

Microsoft Academic Search

There is growing awareness that patterns of habitat use by animals cannot be isolated from issues of scale. Recently, techniques have been devised which allow empirical testing of hypotheses related to the effects of spatial scale on habitat use. We used spatially explicit statistical procedures to examine the roles of scale and habitat arrangement in determining fish distribution patterns in

David A. Crook; Alistar I. Robertson; Alison J. King; Paul Humphries

2001-01-01

75

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

76

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

77

Impact of crop production on air quality in life support dynamics in closed habitats  

SciTech Connect

Interest in human-designed closed habitats - where the substances needed for human life support are continuously regenerated from waste products - is growing, as apparent from the National Aeronautics and Space Administration's Closed Ecological Life Support Systems Program, the Soviet Union's Bios experiments, and the Biosphere II Project in Arizona. Nuclear-powered bases on the moon and Mars will have food-growing capabilities, and through gas-exchange processes these crops will alter the atmospheric composition. This study focuses on major gases tied to human life support: CO/sub 2/, O/sub 2/, and water vapor. Since actual systems are years and likely decades away, simulation studies can indicate necessary further research and provide instruction about the predicted behavior of such systems. To look at the first-order plant dynamics, i.e., the production of O/sub 2/ and water vapor and the consumption of CO/sub 2/, a simulation model is constructed with crop, human, and waste subsystems. The plant can either share an atmosphere with the humans or be separate, linked by osmotic or mechanical gas exchangers. The crop subsystem is sketched. Stoichiometric equations for the biosynthesis of protein, carbohydrates, and lipids in the edible portion and carbohydrates, fiber, and lignin in the inedible portion govern growth, mimicking that currently observed in the latest hydroponic wheat experiments.

Volk, T.

1987-01-01

78

Factors influencing abundance of butterflies and burnet moths in the uncultivated habitats of an organic farm in Denmark  

Microsoft Academic Search

Biotic and abiotic factors causing aggregations of butterflies were investigated in a variety of uncultivated habitats on an organic farm in Denmark. By combining the method of butterfly transect counting with multiple regression analysis, environmental and floral variables influencing butterfly abundance in linear and non-linear uncultivated habitats were identified. Dependent variables were: butterfly totals, Thymelicus spp. (mainly T. lineola), Aphantopus

H. D. Clausen; J. Reddersen

2001-01-01

79

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 with habitat availability to assess whether fish were selecting for spe- cific dissolved oxygen concentrations largemouth bass acclimated to winter tem- peratures. Results from the dissolved oxygen measurements made

Cooke, Steven J.

80

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

81

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

82

Analysis of the Influence of Spatial Pattern in Habitat Selection Studies  

USGS Publications Warehouse

Design and analysis of wildlife habitat selection studies typically do not assess the effect of spatial pattern on the habitat selection process. Effects of landscape scale pattern on habitat selection cannot be accomplished without replicate study areas, because pattern is a single, albeit multifaceted, attribute of an area. For a single area, however, the influence of pattern-related characteristics, such as shape and edge shared with adjacent patches, can be estimated by using GLIM (McCullough and Neider 1983) procedures to model patch-specific frequency counts of animal use as a function of these parameters. This approach is evaluated and illustrated with simulated breeding-bird counts in a South Carolina study area for which a GIS land cover classification is available. A related technique for evaluating whether movement from patch to patch is selective is developed and illustrated for designs that involve collection of trajectory data from monitored individuals. These designs and analyses are feasible given current GIS and GPS technology. Statistical inferences from habitat selection studies should be interpreted within the context of a range of scales at which animals differentiate between patch attributes.

Otis, D.L.

1998-01-01

83

The relative influence of nutrients and habitat on stream metabolism in agricultural streams  

USGS Publications Warehouse

Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was an assessment of habitat in the sampling reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r 2 = 0.79-0.91) and CR-24 (r 2 = 0.76-0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP. ?? 2009 The Author(s).

Frankforter, J.D.; Weyers, H.S.; Bales, J.D.; Moran, P.W.; Calhoun, D.L.

2010-01-01

84

The influence of fine-scale habitat features on regional variation in population performance of alpine White-tailed Ptarmigan  

USGS Publications Warehouse

It is often assumed (explicitly or implicitly) that animals select habitat features to maximize fitness. However, there is often a mismatch between preferred habitats and indices of individual and population measures of performance. We examined the influence of fine-scale habitat selection on the overall population performance of the White-tailed Ptarmigan (Lagopus leucura), an alpine specialist, in two subdivided populations whose habitat patches are configured differently. The central region of Vancouver Island, Canada, has more continuous and larger habitat patches than the southern region. In 2003 and 2004, using paired logistic regression between used (n = 176) and available (n = 324) sites, we identified food availability, distance to standing water, and predator cover as preferred habitat components . We then quantified variation in population performance in the two regions in terms of sex ratio, age structure (n = 182 adults and yearlings), and reproductive success (n = 98 females) on the basis of 8 years of data (1995-1999, 2002-2004). Region strongly influenced females' breeding success, which, unsuccessful hens included, was consistently higher in the central region (n = 77 females) of the island than in the south (n = 21 females, P = 0.01). The central region also had a much higher proportion of successful hens (87%) than did the south (55%, P < 0.001). In light of our findings, we suggest that population performance is influenced by a combination of fine-scale habitat features and coarse-scale habitat configuration. ?? The Cooper Ornithological Society 2011.

Fedy, B.; Martin, K.

2011-01-01

85

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

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

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

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

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

90

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

91

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

EPA Science Inventory

Urban estuarine 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 exam...

92

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...

93

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

94

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

95

Metazoan meiofaunal communities at cold seeps along the Norwegian margin: Influence of habitat heterogeneity and evidence for connection with shallow-water habitats  

NASA Astrophysics Data System (ADS)

Cold-seep environments and their associated symbiont-bearing megafaunal communities create islands of primary production for macro- and meiofauna in the otherwise monotonous and nutrient-poor deep-sea environment. To examine the spatial variation and distribution patterns of metazoan meiobenthos in different seepage-related habitats, samples were collected in two regions off Norway: several pockmarks associated with the Storegga Slide including the Nyegga pockmark area (730 m; 64°N), and the active, methane-venting Håkon Mosby Mud Volcano (HMMV) west of the Barents Sea (1280 m; 72°N). Based on sediment geochemistry and associated epifauna, three different habitat types were distinguished across the two regions: (1) reduced sediment with suboxic conditions, sometimes covered by bacterial mats, (2) sediment colonised by chemosynthetic, siboglinid tubeworms, and (3) sediment outside the influence of seepage and without a large chemosynthetic fauna. Meiofaunal communities varied strongly in terms of generic diversity and dominance among the different habitat types. Control sites and Siboglinidae polychaete fields both supported high nematode genus richness similar to normal deep-sea sediments, whereas the reduced sediments yielded a genus-poor nematode community dominated by one or two successful species. Meiofaunal densities in the different habitats were negatively correlated with macrobenthic densities. An extremely dense (>11,000 ind. 10 cm -2), mono-specific nematode population appeared to be restricted to the bacterial mats at HMMV. It consisted of a new cryptic species of the Halomonhystera disjuncta complex, which has been described from intertidal habitats in the North Sea. The reduced seep sediments at Nyegga did not yield H. disjuncta but were dominated by Terschellingia longicaudata, another cosmopolitan nematode species known to be abundant in organic-rich, oxygen-poor, shallow-water environments. These observations point to a past or recent connection between margins and shallow-water habitats.

Van Gaever, Saskia; Olu, Karine; Derycke, Sofie; Vanreusel, Ann

2009-05-01

96

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

PubMed Central

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

2011-01-01

97

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

98

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

99

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

100

Influence of corallivory, competition, and habitat structure on coral community shifts.  

PubMed

The species composition of coral communities has shifted in many areas worldwide through the relative loss of important ecosystem engineers such as highly branched corals, which are integral in maintaining reef biodiversity. We assessed the degree to which the performance of recently recruited branching corals was influenced by corallivory, competition, sedimentation, and the interactions between these factors. We also explored whether the species-specific influence of these biotic and abiotic constraints helps to explain recent shifts in the coral community in lagoons of Moorea, French Polynesia. Population surveys revealed evidence of a community shift away from a historically acroporid-dominated community to a pocilloporid- and poritid-dominated community, but also showed that the distribution and abundance of coral taxa varied predictably with location in the lagoon. At the microhabitat scale, branching corals grew mainly on dead or partially dead massive Porites ("bommies"), promontories with enhanced current velocities and reduced sedimentation. A demographic study revealed that growth and survival of juvenile Pocillopora verrucosa and Acropora retusa, the two most common branching species of each taxon, were affected by predation and competition with vermetid gastropods. By 24 months of age, 20-60% of juvenile corals suffered partial predation by corallivorous fishes, and injured corals experienced reduced growth and survival. A field experiment confirmed that partial predation by corallivorous fishes is an important, but habitat-modulated, constraint for branching corals. Competition with vermetid gastropods reduced growth of both branching species but unexpectedly also provided an associational defense against corallivory. Overall, the impact of abiotic constraints was habitat-specific and similar for Acropora and Pocillopora, but biotic interactions, especially corallivory, had a greater negative effect on Acropora than Pocillopora, which may explain the local shift in coral community composition. PMID:22073787

Lenihan, Hunter S; Holbrook, Sally J; Schmitt, Russell J; Brooks, Andrew J

2011-10-01

101

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

102

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

E-print Network

The influence of habitat selection and density on the population dynamics of stony coral species of Biology, University of Miami, Coral Gables, FL, 33124 USA *Corresponding author: K. Semon Phone: 1-305-284-3013, Fax: 1-305-284-3039, e-mail: ksemon@bio.miami.edu Abstract Although stony corals are most frequently

Sealey, Kathleen Sullivan

103

The influence of research scale on bald eagle habitat selection along the lower Hudson River, New York (USA)  

Microsoft Academic Search

As the concepts of landscape ecology have been incorporated into other disciplines, the influence of spatial pat- terns on animal abundance and distribution has attracted considerable attention. However, there remains a sig- nificant gap in the application of landscape ecology theories and techniques to wildlife research. By combining landscape ecology techniques with traditional wildlife habitat analysis methods, we defined an

Craig M. Thompson; Kevin McGarigal

2002-01-01

104

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

E-print Network

Microsatellites Ã? 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.

105

Do Habitat Corridors Influence Animal Dispersal and Colonization in Estuarine Systems?  

Microsoft Academic Search

Studies investigating animal response to habitat in marine systems have mainly focused on habitat preference and complexity. This study is one of the first to investigate the affect of benthic habitat corridors and their characteristics on dispersal and colonization by estuarine macrofuana. In this study, mark-recapture field experiments using artificial seagrass units (ASUs) assessed the effects of seagrass corridors, interpatch

Meaghan C. Darcy; David B. Eggleston

2005-01-01

106

Spousal influence on mammography screening: a life course perspective.  

PubMed

Recently, researchers have challenged the basic tenet that marriage is universally protective for all individuals. We scrutinize socio-economic differences between married couples to shed light on the mechanisms underlying the effects of marriage. We introduce the life course perspective to investigate if differences in positive health behavior between couples are related to their early life conditions. Within the theoretical framework of cultural health capital, we hypothesize that the accumulation of cultural health capital proceeds at the marriage level when partners provide each other with health-related information and norms. For this purpose, we examine the influence of the childhood preventive health care behavior of both wives and husbands on the initiation of mammography screening for a sample of Belgian women (N = 734). Retrospective life histories of both partners are provided by the Survey of Health, Ageing and Retirement (SHARE) and are examined by means of event history analysis. The results show that a partner's cultural health capital affects the initiation of mammography screening by a woman in later life, even after her own cultural health capital and traditional measures of socio-economic status (SES) are taken into account. In line with cumulative advantage theory, it seems that inequalities in cultural health capital are accumulated at the marriage level. In order to shed further light on the spousal influence on health behavior, researchers should revert to early life in order to discern the attribution of premarital and marital conditions. PMID:24331883

Missinne, Sarah; Colman, Elien; Bracke, Piet

2013-12-01

107

A hierarchical Bayesian model for embedding larval drift and habitat models in integrated life cycles for exploited fish.  

PubMed

This paper proposes a hierarchical Bayesian framework for modeling the life cycle of marine exploited fish with a spatial perspective. The application was developed for a nursery-dependent fish species, the common sole (Solea solea), on the Eastern Channel population (Western Europe). The approach combined processes of different natures and various sources of observations within an integrated framework for life-cycle modeling: (1) outputs of an individual-based model for larval drift and survival that provided yearly estimates of the dispersion and mortality of eggs and larvae, from spawning grounds to settlement in several coastal nurseries; (2) a habitat suitability model, based on juvenile trawl surveys coupled with a geographic information system, to estimate juvenile densities and surface areas of suitable juvenile habitat in each nursery sector; (3) a statistical catch-at-age model for the estimation of the numbers-at-age and the fishing mortality on subadults and adults. The approach provided estimates of hidden variables and parameters of key biological significance. A simulation approach provided insight to the robustness of the approach when only weak data are available. Estimates of spawning biomass, fishing mortality, and recruitment were close to the estimations derived from stock-assessment working groups. In addition, the model quantified mortality along the life cycle, and estimated site-specific density-dependent mortalities between settled larvae and age-0 juveniles in each nursery ground. This provided a better understanding of the productivity and the specific contribution of each nursery ground toward recruitment and population renewal. Perspectives include further development of the modeling framework on the common sole and applications to other fish species to disentangle the effects of multiple interacting stress factors (e.g., estuarine and coastal nursery habitat degradation, fishing pressure) on population renewal and to develop risk analysis in the context of marine spatial planning for sustainable management of fish resources. PMID:24261047

Rochette, S; Le Pape, O; Vigneau, J; Rivot, E

2013-10-01

108

Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon. Annual Report 1996.  

SciTech Connect

This study is part of a multi-year research project studying aspects of bull trout life history, ecology and genetics. This report covers the activities of the project in 1996. Results and analysis are presented in the following five areas: (1) analysis of the genetic structure of Oregon bull trout populations; (2) distribution and habitat use of bull trout and brook trout in streams containing both species; (3) bull trout spawning surveys; (4) summary and analysis of historical juvenile bull trout downstream migrant trap catches in the Grande Ronde basin; and (5) food habits and feeding behavior of bull trout alone and in sympatry with brook trout.

Bellerud, Blane L.; Gunckel, Stephanie; Hemmingsen, Alan R.; Buchanan, David V.; Howell, Philip J.

1997-10-01

109

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

110

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

111

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

112

Reproductive phenology, life-forms, and habitats of the Venezuelan Central Plain  

Microsoft Academic Search

percentage of species with unripe fruits produced throughout the year was more seasonal for the disturbed area than for the other habitats. Mature fruit patterns showed an increase during the late rainy season for the ecotone and savanna. A large number of herbaceous (annual and perennial) and liana species flowered during the wet season, and a smaller fraction flowered during

NELSON RAMIREZ; Facultad Ciencias

2002-01-01

113

SOUTHEASTERN NATURALIST2010 9(4):673686 Habitat Associations, Life History, and Diet of the  

E-print Network

of the Blackspot Shiner, Notropis atrocaudalis PrestonT. Bean1,* , Casey S.Williams2 , Peter H. Diaz1 , andTimothy H. Bonner1 Abstract - The ecology of Notropis atrocaudalis (Blackspot Shiner) including habitat distribution of Notropis atrocaudalis (Evermann) (Blackspot Shiner) is from the Brazos River drainage in Texas

Aspbury, Andrea S. - Department of Biology, Texas State University

114

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

115

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

116

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

117

Original article Local habitat and landscape influence predation of bird nests on  

E-print Network

plantations on former cropland. Nevertheless these afforestations may cause severe damage to open habitat decreased predation rates and plantation area and magpie (Pica pica) abundance increased predation rates

Rey Benayas, José María

118

Differential influence of a monotypic and diverse native aquatic plant bed on a macroinvertebrate assemblage; an experimental implication of exotic plant induced habitat  

Microsoft Academic Search

Aquatic plants mediate ecological processes in aquatic habitats, specifically predator–prey (bluegill sunfish (Lepomis macrochirus Rafinesque)-macroinvertebrate) interactions. Macroinvertebrate colonization is directly and indirectly influenced by substrate\\u000a heterogeneity, interstitial space, and surface complexity. Exotic invasive plant species, such as Hydrilla verticillata L.F. Royle, may alter the available structure in aquatic habitat by creating a shift to a homogeneous habitat, thus affecting\\u000a the

Heather J. Theel; Eric D. Dibble; John D. Madsen

2008-01-01

119

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

120

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

121

Ecological constraints on breeding system evolution: the influence of habitat on brood desertion in Kentish plover.  

PubMed

1. One of the fundamental insights of behavioural ecology is that resources influence breeding systems. For instance, when food resources are plenty, one parent is able to care for the young on its own, so that the other parent can desert and became polygamous. We investigated this hypothesis in the context of classical polyandry when females may have several mates within a single breeding season, and parental duties are carried out largely by the male. 2. We studied a precocial wader, the Kentish plover Charadrius alexandrinus, that exhibits variable brood care such that the chicks may be raised by both parents, only by the female or, more often, only by the male. The timing of female desertion varies: some females desert their brood at hatching of the eggs and lay a clutch for a new mate, whereas other females stay with their brood until the chicks fledge. Kentish plovers are excellent organisms with which to study breeding system evolution, as some of their close relatives exhibit classical polyandry (Eurasian dotterel Eudromias morinellus, mountain plover Charadrius montanus), whereas others are polygynous (northern lapwing Vanellus vanellus). 3. Kentish plovers raised their broods in two habitats in our study site in southern Turkey: saltmarsh and lakeshore. Food intake was higher on the lakeshore than in the saltmarsh as judged from feeding behaviour of chicks and adults. As the season proceeded and the saltmarsh dried out, the broods moved toward the lakeshore. 4. As the density of plovers increased on lakeshore, the parents spent more time defending their young, and female parents stayed with their brood longer on the lakeshore. 5. We conclude that the influence of food abundance on breeding systems is more complex than currently anticipated. Abundant food resources appear to have profound implications on spatial distribution of broods, and the social interactions between broods constrain female desertion and polyandry. PMID:16903063

Kosztolányi, András; Székely, Tamas; Cuthill, Innes C; Yilmaz, K Tuluhan; Berberoglu, Süha

2006-01-01

122

The influence of habitat structure and flow permanence on invertebrate communities in karst spring systems  

Microsoft Academic Search

The macroinvertebrate fauna of five karst (limestone) springbrook systems with contrasting physical habitat and discharge patterns were investigated to examine the role of flow permanence and habitat structure on macroinvertebrate community composition. Clear physical differences were identified between perennial and intermittent springs and individual sampling stations. However, flow permanence, water temperature and the input of leaf litter exerted a greater

H. Smith; P. J. Wood; J. Gunn

2003-01-01

123

The influence of matrix habitat on Aphthona flea beetle immigration to leafy spurge patches  

Microsoft Academic Search

Variation in movement ability by insects among different non-habitat (matrix) types may have important implications for both metapopulation dynamics and weed biocontrol practices. We used a mark-recapture experi- ment to explore the effects of two different matrix habitats (grass vs shrub) on the ability of two species of Aphthona (Chrysomelidae: Coleoptera) flea beetle to immigrate to patches of the invasive

Ian D. Jonsen; Robert S. Bourchier; Jens Roland

2001-01-01

124

Influences of environmental cues, migration history, and habitat familiarity on partial migration  

Microsoft Academic Search

The factors that drive partial migration in organisms are not fully understood. Roach (Rutilus rutilus), a freshwater fish, engage in partial migration where parts of populations switch between summer habitats in lakes and winter habitats in connected streams. To test if the partial migration trait is phenotypically plastic or has genetic components, we translocated roach from 2 populations with different

Christian Skov; Kim Aarestrup; Henrik Baktoft; Jakob Brodersen; Christer Brönmark; Lars-Anders Hansson; Einar E. Nielsen; Tine Nielsen; P. Anders Nilsson

2010-01-01

125

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

126

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

127

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

128

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

129

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

E-print Network

these14 afforestations may cause severe damage to open habitat species, especially birds of high15 and plantation area and20 magpie (Pica pica) abundance increased predation rates within tree plantations, which

Carrascal, Luis M.

130

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...

131

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

132

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

USGS Publications Warehouse

Redhorse, Moxostoma spp., are considered to be negatively affected by dams although this assertion is untested for Canadian populations. One hundred and fifty-one sites in the Grand River watershed were sampled to identify factors influencing the distribution of redhorse species. Individual species of redhorse were captured from 3 to 32% of sites. The most widespread species were golden redhorse, M. erythrurum (30%) and greater redhorse, M. valenciennesi (32%), while river redhorse, M. carinatum, was only found along the lower Grand River. Redhorse were absent from the highly fragmented Speed River sub-watershed and upper reaches of the Conestogo River and the Grand River. Redhorse species richness was positively correlated to river fragment size and upstream drainage area. Generalized additive models (GAMs) were applied to evaluate the influence of river fragment length, connectivity and habitat on species distribution. Principal component analysis reduced habitat data to three axes representing: channel structure, substrate, and pool, riffle and run habitats (PC1); gradient and drainage area (PC2); and cover (PC3). GAMs indicate that PC2 was important for predicting black redhorse and greater redhorse site occupancy and PC1 was important for golden redhorse. River fragment length was important for predicting site occupancy for shorthead redhorse, but not other species. ?? 2006 Springer Science+Business Media, Inc.

Reid, S.M.; Mandrak, N.E.; Carl, L.M.; Wilson, C.C.

2008-01-01

133

MEDITERRANEAN CLIMATE STREAMS Review Paper Maintaining and restoring hydrologic habitat connectivity  

E-print Network

floodplain habitat in a med-river, the San Joaquin River, California. Case study results show splittail Á Chinook salmon Introduction Aristotle considered the Mediterranean basin as the only place and life history requirements that together influence ha

Merenlender, Adina

134

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

135

Life history of Gonatus onyx (Cephalopoda: Teuthoidea): ontogenetic changes in habitat, behavior and physiology  

Microsoft Academic Search

In the present study 670 individuals of Gonatus onyx (Cephalopoda: Teuthoidea) were observed in Monterey Bay, California from a remotely operated vehicle. The vertical distribution\\u000a of this species was bimodal, with peaks at 400 and 800?m depth during the day and 300 and 500?m during the night. The bimodal\\u000a distribution reflects a life stage shift between younger, schooling juveniles living

J. C. Hunt; B. A. Seibel

2000-01-01

136

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

137

Relationship between growth and standard metabolic rate: measurement artefacts and implications for habitat use and life-history adaptation in salmonids.  

PubMed

Mass-specific standard metabolic rate (SMR, or maintenance metabolism) varies greatly among individuals. Metabolism is particularly sensitive to variation in food consumption and growth creating the potential for significant bias in measured SMR for animals that are growing (e.g. juveniles) or of uncertain nutritional status. Consequently, interpreting individual variation in metabolism requires a sound understanding of the potentially confounding role of growth and the relative importance of fixed (genetic) vs. environmental drivers of SMR variation. We review the role of growth in measured SMR variation in juvenile salmonids, with the goals of (i) understanding the contribution of growth (and food consumption) to SMR variation through ontogeny, (ii) understanding the relative contributions of tissue maintenance and biosynthesis (overhead costs of growth) to apparent SMR variation, and (iii) using intrinsic growth effects on SMR to model how alternate life-history strategies may influence growth and measured SMR in juvenile salmonids. SMR measures on juveniles, even when post-absorptive, may be inflated by delayed growth-associated overhead costs, unless juveniles are on a maintenance ration (i.e. not growing). Empirical measurements of apparent SMR in food restricted vs. satiated 2-5 g juvenile salmon demonstrate that estimates may be inflated by as much as 67% due to delayed overhead costs of growth, even when SMR measurements are taken 35 h post-feeding. These results indicate that a substantial component of variation in apparent SMR among juvenile salmonids may be associated with (i) environmentally driven variation in ration (where elevated SMR measurements are an artefact of delayed growth overhead costs), (ii) intrinsic (genetic) or plastic organ-system trade-offs related to increasing investment in metabolically expensive digestive tissue responsible for processing food and (iii) intrinsic (genetic) variation in maximum body size and growth among individuals or life-history types. We suggest that selection for differences in adult body size among resident and anadromous forms leading to differences in juvenile growth trajectories may contribute to both SMR variation and habitat segregation in freshwater, where juveniles with higher growth are constrained to foraging in high velocity habitats to meet their greater consumption needs. PMID:24930825

Rosenfeld, Jordan; Van Leeuwen, Travis; Richards, Jeffrey; Allen, David

2014-06-16

138

Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 2000.  

SciTech Connect

This section describes work accomplished in 2000 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 continued to monitor the movements of bull trout with radio transmitters applied in 1998 (Hemmingsen, Bellerud, Gunckel and Howell 2001) and 1999 (Hemmingsen, Gunckel and Howell 2001). No new radio transmitters were applied to bull trout of the upper John Day River subbasin, Mill Creek (Walla Walla Basin), or the Grande Ronde Basin in 2000. We did implant radio transmitters in two bull trout incidentally captured in the John Day River near the confluence of the North Fork John Day River. In Mill Creek, we used traps to capture migrant bull trout to obtain data for the third successive year in this stream. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, and to determine the relative abundance, size and age of migrant fish. Because we captured migrant bull trout with traps for three years in the upper John Day River and its tributaries (Hemmingsen, Bellerud, Buchanan, Gunckel, Shappart and Howell 2001; Hemmingsen, Bellerud, Gunckel and Howell 2001; Hemmingsen, Gunckel and Howell 2001) and traps were no longer needed to capture bull trout for radio-tagging, no traps were operated in the John Day Basin in 2000.

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

2001-11-01

139

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, Jon M.

2013-01-01

140

Fatty Acid Composition at the Base of Aquatic Food Webs Is Influenced by Habitat Type and Watershed Land Use  

PubMed Central

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. PMID:23940619

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

2013-01-01

141

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

142

Depth and medium-scale spatial processes influence fish assemblage structure of unconsolidated habitats in a subtropical marine park.  

PubMed

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

143

Adjacent habitat influence on stink bug (Hemiptera: Pentatomidae) densities and the associated damage at field corn and soybean edges.  

PubMed

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

144

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

145

Microbiome analysis among bats describes influences of host phylogeny, life history, physiology and geography  

E-print Network

Microbiome analysis among bats describes influences of host phylogeny, life history, physiology and their microbial inhabitants. Previous studies have provided the conceptual realization that microbiomes influence of variables in shaping observed microbiome relationships. The variables ranged from those

Nachman, Michael

146

Predicting Influences of Urban Development on Thermal Habitat in a Warm Water Stream  

NASA Astrophysics Data System (ADS)

Watershed and aquatic ecosystem management requires methods to predict and understand thermal impacts on stream habitat from urbanization. This study evaluates thermal effects of projected urbanization using a modeling framework and considers the biological implications to the fish community. The Stream Network Temperature Model (SNTEMP) was used in combination with the Hydrologic Simulation Program Fortran (HSPF) to assess changes in stream thermal habitat under altered streamflow, shade, and channel width associated with low, medium, and high density urban developments in the Back Creek watershed (Roanoke County, Virginia). Flow alteration by the high density development scenario alone caused minimal heating of mean daily summer base flow (mean +0.1°C). However, when flow changes were modeled concurrently with reduced shade and increased channel width, mean daily temperature increased 1°C. Maximum daily temperatures exceeding the state standard (31°C) increased from 1.1 to 7.6 percent of the time using summer 2000 climatic conditions. Model results suggest that additional urban development will alter stream temperature, potentially limiting thermal habitat and shifting the fish community structure from intolerant to tolerant fish species in Back Creek. More research is needed on the sublethal or chronic effects of increased stream temperature regimes on fish, particularly for those species already living in habitats near their upper limits.

Krause, Colin W.; Lockard, Brendan; Newcomb, Tammy J.; Kibler, David; Lohani, Vinod; Orth, Donald J.

2004-12-01

147

Stand age and habitat influences on salamanders in Appalachian cove hardwood forests  

Microsoft Academic Search

We surveyed cove hardwood stands aged 15, 25, 50, and ?85 years following clearcutting in the southern Appalachian Mountains of northern Georgia to assess the effects of stand age and stand habitat characteristics on salamander communities using drift-fence array and pitfall methodologies from May 1994 to April 1995. Over a 60,060 pitfall trapnight effort, we collected 3937 salamanders represented by

W. Mark Ford; Brian R Chapman; Michael A Menzel; Richard H Odom

2002-01-01

148

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...

149

Invasion of a mined landscape: what habitat characteristics are influencing the occurrence of invasive plants?  

Microsoft Academic Search

Throughout the world, the invasion of alien plants is an increasing threat to native biodiversity. Invasion is especially prevalent in areas affected by land transformation and anthropogenic disturbance. Surface mines are a major disturbance, and thus may promote the establishment and expansion of invasive plant communities. Environmental and habitat factors that may contribute to favourable conditions for heightened plant invasion

D. Lemke; C. J. Schweitzer; I. A. Tazisong; Y. Wang; J. A. Brown

2012-01-01

150

Influence of prairie dogs ( Cynomys ludovicianus ) on habitat heterogeneity and mammalian diversity in Mexico  

Microsoft Academic Search

Prairie dogs are considered to be both a keystone species and an ecosystem engineer in grasslands. To partially test these hypotheses we evaluated burrow densities, soil removal, and mammal (i.e. rodents and carnivores) species composition, richness, diversity, and abundance in grasslands with and without prairie dogs (Cynomys ludovicianus) in north-western Mexico. We measured habitat heterogeneity as a function of burrow

Gerardo Ceballos; Jesús Pacheco; Rurik List

1999-01-01

151

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

152

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

153

Simulating the influences of various fire regimes on caribou winter habitat  

USGS Publications Warehouse

Caribou are an integral component of high-latitude ecosystems and represent a major subsistence food source for many northern people. The availability and quality of winter habitat is critical to sustain these caribou populations. Caribou commonly use older spruce woodlands with adequate terrestrial lichen, a preferred winter forage, in the understory. Changes in climate and fire regime pose a significant threat to the long-term sustainability of this important winter habitat. Computer simulations performed with a spatially explicit vegetation succession model (ALFRESCO) indicate that changes in the frequency and extent of fire in interior Alaska may substantially impact the abundance and quality of winter habitat for caribou. We modeled four different fire scenarios and tracked the frequency, extent, and spatial distribution of the simulated fires and associated changes to vegetation composition and distribution. Our results suggest that shorter fire frequencies (i.e., less time between recurring fires) on the winter range of the Nelchina caribou herd in eastern interior Alaska will result in large decreases of available winter habitat, relative to that currently available, in both the short and long term. A 30% shortening of the fire frequency resulted in a 3.5-fold increase in the area burned annually and an associated 41% decrease in the amount of spruce-lichen forest found on the landscape. More importantly, simulations with more frequent fires produced a relatively immature forest age structure, compared to that which currently exists, with few stands older than 100 years. This age structure is at the lower limits of stand age classes preferred by caribou from the Nelchina herd. Projected changes in fire regime due to climate warming and/or additional prescribed burning could substantially alter the winter habitat of caribou in interior Alaska and lead to changes in winter range use and/or population dynamics. ?? 2006 by the Ecological Society of America.

Rupp, T.S.; Olson, M.; Adams, L.G.; Dale, B.W.; Joly, Kyle; Henkelman, J.; Collins, W.B.; Starfield, A.M.

2006-01-01

154

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

155

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

156

Seasonal Movement and Habitat Use by Subadult Bull Trout in the Upper Flathead River System, Montana  

Microsoft Academic Search

Despite the importance of large-scale habitat connectivity to the threatened bull trout Salvelinus confluentus, little is known about the life history characteristics and processes influencing natural dispersal of migratory populations. We used radiotelemetry to investigate the seasonal movements and habitat use by subadult bull trout (i.e., fish that emigrated from natal streams to the river system) tracked for varying durations

Clint C. Muhlfeld; Brian Marotz

2005-01-01

157

Cypris Habitat Selection Facilitated by Microbial Films Influences the Vertical Distribution of Subtidal Barnacle Balanus trigonus  

Microsoft Academic Search

The potential driving force(s) of the vertical distribution of subtidal barnacle Balanus trigonus Darwin were investigated using both field and laboratory experiments. Early juveniles (?24 h old) placed in intertidal [?0.5 m above mean low water level (MLWL)] and subtidal (?3 m below MLWL) habitats survived equally well, indicating that the intertidal absence of B. trigonus in Hong Kong waters was not determined

Vengatesen Thiyagarajan; Stanley C. K. Lau; Sam C. K. Cheung; Pei-Yuan Qian

2006-01-01

158

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

159

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

160

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

161

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

162

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

163

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

164

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

165

Reciprocal Influences between Stressful Life Events and Adolescent Internalizing and Externalizing Problems.  

ERIC Educational Resources Information Center

Investigated hypothesized reciprocal influences between stressful life events and adolescent maladjustment using data from 6-year, prospective longitudinal study. Found that from seventh to twelfth grades, stressful life events, internalizing symptoms, and externalizing behaviors were reciprocally interrelated over time. Found that stressful life…

Kim, Kee Jeong; Conger, Rand D.; Elder, Glen H., Jr.; Lorenz, Frederick O.

2003-01-01

166

Low-crested coastal defence structures as artificial habitats for marine life: Using ecological criteria in design  

Microsoft Academic Search

Coastal defence structures to protect sedimentary coastlines from erosion and flooding are increasingly common throughout Europe. They will become more widespread over the next 10–30 years in response to rising and stormier seas and accelerating economic development of the coastal zone. Building coastal defences results in the loss and fragmentation of sedimentary habitats and their replacement by artificial rocky habitats

P. S. Moschella; M. Abbiati; P. Åberg; L. Airoldi; J. M. Anderson; F. Bacchiocchi; F. Bulleri; G. E. Dinesen; M. Frost; E. Gacia; L. Granhag; P. R. Jonsson; M. P. Satta; A. Sundelöf; R. C. Thompson; S. J. Hawkins

2005-01-01

167

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)'

168

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

169

The influence of habitat structure on genetic differentiation in red fox populations in north-eastern Poland.  

PubMed

The red fox (Vulpes vulpes) has the widest global distribution among terrestrial carnivore species, occupying most of the Northern Hemisphere in its native range. Because it carries diseases that can be transmitted to humans and domestic animals, it is important to gather information about their movements and dispersal in their natural habitat but it is difficult to do so at a broad scale with trapping and telemetry. In this study, we have described the genetic diversity and structure of red fox populations in six areas of north-eastern Poland, based on samples collected from 2002-2003. We tested 22 microsatellite loci isolated from the dog and the red fox genome to select a panel of nine polymorphic loci suitable for this study. Genetic differentiation between the six studied populations was low to moderate and analysis in Structure revealed a panmictic population in the region. Spatial autocorrelation among all individuals showed a pattern of decreasing relatedness with increasing distance and this was not significantly negative until 93 km, indicating a pattern of isolation-by-distance over a large area. However, there was no correlation between genetic distance and either Euclidean distance or least-cost path distance at the population level. There was a significant relationship between genetic distance and the proportion of large forests and water along the Euclidean distances. These types of habitats may influence dispersal paths taken by red foxes, which is useful information in terms of wildlife disease management. PMID:24954926

Mullins, Jacinta; McDevitt, Allan D; Kowalczyk, Rafa?; Ruczy?ska, Iwona; Górny, Marcin; Wójcik, Jan M

2014-01-01

170

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

171

Deep-sea habitat heterogeneity influence on meiofaunal communities in the Gulf of Guinea  

NASA Astrophysics Data System (ADS)

To estimate the degree of spatial heterogeneity of benthic deep-sea communities, we carried out a multiple-scale (from m's to 200 km) investigation in the Congo-Angola margins (Equatorial West African margin, 3150-4800 m) in which we examined the metazoan meiofauna at a variety of habitats along the Congo Channel system and in the associated cold seep. We investigate the structure, density, vertical distribution patterns in the sediment and biomass of meiofaunal communities in the Gulf of Guinea and how they are controlled by hydrologic and biogeochemical processes. The meiofaunal communities in the Gulf of Guinea were shaped by heterogeneous conditions on the margin, and reflect the multiple-scale spatial variability that corresponds with the different identified habitats. The two control sites, located at >100 km away from the canyon, were inhabited by very dense and the most diverse meiobenthic communities. Similar meiobenthic communities inhabited the transition zone between the canyon and the cold seep. Sites located along the Congo Channel were obviously affected by the local high-velocity bottom currents and unstable sedimentary conditions in this active submarine system. Extremely low meiobenthic densities and very low proportions in the most surficial sediment layers provided evidence for recently highly disturbed sediments at these sites. The remote operated vehicle (ROV) Victor 6000 provided images of the cold seep, showing a patchy distribution of several types of patchy distributed megafaunal communities dominated by three key symbiotic taxa (Mytilidae, Vesicomyidae and Siboglinidae). These cold seep sediments were colonised by a unique meiobenthic community, characterised by a high small-scale (m's) patchiness, low species richness and the prominent dominance of two large-sized nematode species: Sabatieria mortenseni, which is a cosmopolitan nematode known from littoral habitats, and an undescribed Desmodora species. The high individual body weight of S. mortenseni and its dominance at the cold seep site resulted in a significantly higher nematode biomass at the seep compared to the surrounding sites. In addition, the vertical nematode profiles, with maximum proportions in subsurficial layers, points to a chemosynthesis-based meiobenthic community in this cold seep, in contrast to the phytodetritus-based communities at the control sites and at the transition zone.

Van Gaever, Saskia; Galéron, Joëlle; Sibuet, Myriam; Vanreusel, Ann

2009-12-01

172

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

173

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

174

The influence of life events on physical activity patterns of Dutch older adults: A life history method.  

PubMed

Objective: Physical activity (PA) can improve well-being and health during older age. This study explored how life events influence PA patterns of older adults. Design: Seventeen interviews with older adults were conducted using a life history method. PA patterns during the life course were identified, including information on when, how and why changes in PA occurred. Results: Four different response patterns that affect PA patterns after life events (e.g. death of partner) were discerned as follows: 'I want to be physically active, but there are too many barriers', 'I have reached a point in my life where I do not have to be so active any more', 'I need to exercise now if I want to live the life I want' and 'I have always been active and cannot do without PA'. Which response pattern an older adult held was strongly related to PA development during earlier life (physical capital), and present and future self-conceptions. Conclusions: When developing interventions to enhance PA in older age, it is important to take into account the diversity of views on PA, based on physical capital and current and future self-conceptions. The life history method appeared valuable, providing a thorough understanding of changes in PA patterns. PMID:24942133

Kenter, Elise J; Gebhardt, Winifred A; Lottman, Irene; van Rossum, Mariët; Bekedam, Margreet; Crone, Mathilde R

2014-07-17

175

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

176

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

177

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

178

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

179

Estimating susceptibility of biological control agents to pesticides: influence of life history strategies and population structure  

Microsoft Academic Search

In this study we examined the influences that differing life history strategies and population structures at the time of pesticide exposure have on population susceptibility to pesticides. We used life table data and a matrix projection model to incorporate combinations of mortality (lethal effect) and reductions in fecundity (sublethal effect) into estimates of intrinsic population growth rates (r) for a

John D Stark; John E Banks; Susanna Acheampong

2004-01-01

180

Genetic and Environmental Influences on Life History Traits in Lake Trout  

Microsoft Academic Search

Lake trout Salvelinus namaycush exhibit substantial life history variation associated with variation in climatic and biotic variables. To assess the environmental and genetic influences on lake trout life history traits, eggs were collected from two lakes in Algonquin Park, Ontario, Lake Opeongo and Louisa Lake, with contrasting ecotypes and forage bases. Eggs from both populations and interpopulation hybrids (Lake Opeongo

Jenni L. McDermid; Peter E. Ihssen; William N. Sloan; Brian J. Shuter

2007-01-01

181

Factors Influencing Health-Related Quality of Life Among Minority Elders in Southwest China  

Microsoft Academic Search

This study described health-related quality of life and examined the relationship of factors influencing health-related quality of life among minority elders in southwest China. A descriptive correlational study was conducted with a convenience sample of 105 community-dwelling minority elders in Southwest China. The participants reported poor physical health-related quality of life. Depression, chronic diseases, and body mass index were predictors

Dan Luo; Jie Hu

2011-01-01

182

Ecological constraints on breeding system evolution: the influence of habitat on brood desertion in Kentish plover  

Microsoft Academic Search

Summary 1. One of the fundamental insights of behavioural ecology is that resources influence breeding systems. For instance, when food resources are plenty, one parent is able to care for the young on its own, so that the other parent can desert and became polygamous. We investigated this hypothesis in the context of classical polyandry when females may have several

TAMÁS SZÉKELY; INNES C. CUTHILL; K. TULUHAN YILMAZ

183

Diversity in skeletal architecture influences biological heterogeneity and Symbiodinium habitat in corals.  

PubMed

Scleractinian corals vary in response to rapid shifts in the marine environment and changes in reef community structure post-disturbance reveal a clear relationship between coral performance and morphology. With exceptions, massive corals are thought to be more tolerant and branching corals more vulnerable to changing environmental conditions, notably thermal stress. The typical responses of massive and branching coral taxa, respectively, are well documented; however, the biological and functional characteristics that underpin this variation are not well understood. We address this gap by comparing multiple biological attributes that are correlated with skeletal architecture in two perforate (having porous skeletal matrices with intercalating tissues) and two imperforate coral species (Montipora aequituberculata, Porites lobata, Pocillopora damicornis, and Seriatopora hystrix) representing three morphotypes. Our results reveal inherent biological heterogeneity among corals and the potential for perforate skeletons to create complex, three-dimensional internal habitats that impact the dynamics of the symbiosis. Patterns of tissue thickness are correlated with the concentration of symbionts within narrow regions of tissue in imperforate corals versus broad distribution throughout the larger tissue area in perforate corals. Attributes of the perforate and environmentally tolerant P. lobata were notable, with tissues ?5 times thicker than in the sensitive, imperforate species P. damicornis and S. hystrix. Additionally, P. lobata had the lowest baseline levels of superoxide and Symbiodinium that provisioned high levels of energy. Given our observations, we hypothesize that the complexity of the visually obscured internal environment has an impact on host-symbiont dynamics and ultimately on survival, warranting further scientific investigation. PMID:23992772

Yost, Denise M; Wang, Li-Hsueh; Fan, Tung-Yung; Chen, Chii-Shiarng; Lee, Raymond W; Sogin, Emilia; Gates, Ruth D

2013-10-01

184

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

185

Livestock grazing and sage-grouse habitat: impacts and opportunities  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sage-grouse obtain resources from sagebrush communities for breeding, summer, and winter life stages. Grazing changes the productivity, composition, and structure of herbaceous plants in sagebrush communities, thus directly influencing the productivity of nesting and early brood-rearing habitats. In...

186

Factors Influencing Vocational Teachers' Mid-Life Career Decisions.  

ERIC Educational Resources Information Center

A study was conducted to increase understanding of the mid-life career decision factors of vocational teachers in trade and industrial education. A sample of 179 conditionally licensed occupational teachers in Indiana who had initially been employed in industrial occupations were willing to participate in the study. Four additional criteria were…

Wittkamper, John Randal; Harris, Robert C.

187

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

188

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

189

Factors influencing the notch rupture life of superalloy 718  

Microsoft Academic Search

The superalloy grade 718 is used extensively for aeroengine applications. Since the fabricated structures operate at high\\u000a temperatures and engine-designer has also to reckon with stress concentrations, notched stress rupture testing is an important\\u000a acceptance criterion. The specification stipulates a minimum life of 23 hours and minimum elongation of 4%, when testing is\\u000a done on specimens with a combined notched

M. Nageswara Rao

2010-01-01

190

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

191

Some instances of the influence of dreams on waking life  

Microsoft Academic Search

Examines the influence of dreams on many of the waking processes especially the occurrence of certain mood states, of foreboding, anxiety, gaiety, and beliefs and daily conduct. It was found possible to trace these to corresponding affects that dominated the dreams of the previous night, in normals as well to an even greater extent in abnormal individuals, and in psychopathology,

Ernest Jones

1911-01-01

192

The influence of habitats on female mobility in Central and Western Africa inferred from human mitochondrial variation  

PubMed Central

Background When studying the genetic structure of human populations, the role of cultural factors may be difficult to ascertain due to a lack of formal models. Linguistic diversity is a typical example of such a situation. Patrilocality, on the other hand, can be integrated into a biological framework, allowing the formulation of explicit working hypotheses. The present study is based on the assumption that patrilocal traditions make the hypervariable region I of the mtDNA a valuable tool for the exploration of migratory dynamics, offering the opportunity to explore the relationships between genetic and linguistic diversity. We studied 85 Niger-Congo-speaking patrilocal populations that cover regions from Senegal to Central African Republic. A total of 4175 individuals were included in the study. Results By combining a multivariate analysis aimed at investigating the population genetic structure, with a Bayesian approach used to test models and extent of migration, we were able to detect a stepping-stone migration model as the best descriptor of gene flow across the region, with the main discontinuities corresponding to forested areas. Conclusions Our analyses highlight an aspect of the influence of habitat variation on human genetic diversity that has yet to be understood. Rather than depending simply on geographic linear distances, patterns of female genetic variation vary substantially between savannah and rainforest environments. Our findings may be explained by the effects of recent gene flow constrained by environmental factors, which superimposes on a background shaped by pre-agricultural peopling. PMID:23360301

2013-01-01

193

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

194

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

PubMed

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

2013-10-23

195

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

196

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

197

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

198

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

199

Individual Variation in Life History Characteristics Can Influence Extinction Risk  

SciTech Connect

The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

Jager, H.I.

2001-01-01

200

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.

201

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

202

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...

203

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

204

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

205

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

206

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

207

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

208

Factors influencing survival and postoperative quality of life after mitral valve reconstruction  

Microsoft Academic Search

Objective: Mitral valve reconstruction (MVR) is the preferred treatment for regurgitant lesions. Clinical benefit is well documented, but comparative data scrutinising factors influencing survival and postoperative quality of life (QOL) in different subsets of patients are missing. We hypothesised that mitral valve reconstruction for mitral regurgitation benefits the patients, regardless of the valve pathology. Methods: In this study, 663 consecutive

Lorenz Hansen; Stephan Winkel; Jannick Kuhr; Ralf Bader; Niels Bleese; Friedrich-Christian Riess

2010-01-01

209

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

210

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

211

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

212

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

213

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

214

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

215

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.

216

Habitat Alteration  

E-print Network

Habitat alteration is a change in land use or land cover that has an impact on local ecosystems. Plants and animals live in specific places that have the conditions of climate and food resources needed for survival. Habitats

unknown authors

217

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

218

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...

219

Physical factors and their influence on the mussel fauna of a main channel border habitat of the upper Mississippi River  

USGS Publications Warehouse

The habitats of mussel species in a portion of the main stem of Navigation Pool 10 of the upper Mississippi River were examined. Population composition, abundance, and sediment and current preferences were measured at 186 sites in the East Channel of the pool. Although total mussel abundance varied significantly as a function of sediment and current (p less than or equal to 0.05), abundance could be predicted in only 44% of sites by discriminant analysis models. Accurate prediction of abundance for most species also was poor. Species showed little discrimination in choosing main channel habitats, but could be broadly classified into species preferring fine to medium-fine sands (e.g., Truncilla truncata and Potamilus alatus) or coarser sands (e.g., Lampsilis cardium and Truncilla donaciformis). The endangered Lampsilis higginsi was found in a broad range of habitats similar to those occupied by many of the more common species, suggesting factors other than loss of adult habitat for the rarity of this species.

Holland Bartels, L. E.

1990-01-01

220

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

221

The influence of disturbance and habitat on the presence of non-native plant species along transport corridors  

Microsoft Academic Search

The impact from transportation corridors on surrounding habitat often reaches far beyond the edge of the corridor. The altered disturbance regime in plant communities along corridor edges and vehicle traffic facilitate the spread and establishment of invasive non-native plant species. We compared the frequency of non-native plant species along highways and railways and the ability of these species to invade

Malin J. Hansen; Anthony P. Clevenger

2005-01-01

222

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...

223

Habitat selection of two gobies ( Microgobius gulosus, Gobiosoma robustum): influence of structural complexity, competitive interactions, and presence of a predator  

Microsoft Academic Search

Herein I compare the relative importance of preference for structurally complex habitat against avoidance of competitors and predators in two benthic fishes common in the Gulf of Mexico. The code goby Gobiosoma robustum Ginsburg and clown goby Microgobius gulosus (Girard) are common, ecologically similar fishes found throughout the Gulf of Mexico and in the southeastern Atlantic Ocean. In Florida Bay,

Pamela J Schofield

2003-01-01

224

Suitability of ponds formed by strip mining in eastern Oklahoma for public water supply, aquatic life, waterfowl habitat, livestock watering, irrigation, and recreation  

USGS Publications Warehouse

A study of coal ponds formed by strip mining in eastern Oklahoma included 25 ponds formed by strip mining from the Croweburg, McAlester, and Iron Post coal seams and 6 noncoal-mine ponds in the coal-mining area. Water-quality samples were collected in the spring and summer of 1985 to determine the suitability of the ponds for public water supply, aquatic life, waterfowl habitat, livestock watering, irrigation, and recreation. The rationale for water-quality criteria and the criteria used for each proposed use are discussed. The ponds were grouped by the coal seam mined or as noncoal-mine ponds, and the number of ponds from each group containing water that exceeded a given criterion is noted. Water in many of the ponds can be used for public water supplies if other sources are not available. Water in most of these ponds exceeds one or more secondary standards, but meets all primary standards. Water samples from the epilimnion (shallow strata as determined by temperature) of six ponds exceeded one or more primary standards, which are criteria protective of human health. Water samples from five of eight Iron Post ponds exceeded the selenium criterion. Water samples from all 31 ponds exceeded one or more secondary standards, which are for the protection of human welfare. The criteria most often exceeded were iron, manganese, dissolved solids, and sulfate, which are secondary standards. The criteria for iron and manganese were exceeded more frequently in the noncoal-mine ponds, whereas ponds formed by strip mining were more likely to exceed the criteria for dissolved solids and sulfate. The ponds are marginally suited for aquatic life. Water samples from the epilimnion of 18 ponds exceeded criteria protective of aquatic life. The criteria for mercury and iron were exceeded most often. Little difference was detected between mine ponds and noncoal-mine ponds. Dissolved oxygen concentrations in the hypolimnion (deepest strata) of all the ponds were less than the minimum criterion during the summer. This decreases available fish habitat and affects the type and number of benthic invertebrates. The ponds are generally well suited for use by wintering and migrating waterfowl. Thirteen of the ponds contained water that exceeded the pH, alkalinity, and selenium criteria. The noncoal-mine ponds had the largest percentage of ponds exceeding pH and alkalinity criteria. Water samples from five of eight Iron Post ponds exceeded the selenium criterion. All ponds are generally unsuitable as waterfowl habitat during the summer because of high temperatures and low dissolved oxygen. Most of the ponds are well suited for livestock watering. Water samples from the epilimnion of 29 ponds met all chemical and physical criteria. Water samples from five ponds exceeded the criteria in the hypolimnion. Mine ponds exceeded chemical and physical criteria more often than noncoal-mine ponds. All the ponds contained phytoplankton species potentially toxic to livestock. Water from most of the ponds is marginally suitable for irrigation of sensitive crops, but is more suitable for irrigation of semitolerant and tolerant crops. Most major cash crops grown in eastern Oklahoma are semitolerant and tolerant crops. Water from the epilimnion of 14 ponds was suitable for irrigation under almost all conditions. Water from the epilimnion of 20 ponds was suitable for irrigation of semitolerant crops, and water from the epilimnion of 25 ponds is suitable for irrigation of tolerant crops. The dissolved solids criterion was exceeded the most often. Most of the ponds would not be suitable for swimming. The pH criterion was exceeded in 17 ponds and turbidity restricts visibility needed for diving in 23 ponds. Little difference was detected between mine ponds and noncoal-mine ponds. Many of the ponds formed by strip mining have steep banks that may be dangerous to swimmers.

Parkhurst, Renee S.

1994-01-01

225

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

226

Life Experiences and Resilience in College Students: A Relationship Influenced by Hope and Mindfulness  

E-print Network

, Hobfoll et al. (2009) found resilience to be less common than symptoms of significant psychological distress or posttraumatic stress. In what they describe as the first ?longitudinal examination of resilience and resistance (rather than ill-being) among... fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY August 2009 Major Subject: Counseling Psychology LIFE EXPERIENCES AND RESILIENCE IN COLLEGE STUDENTS: A RELATIONSHIP INFLUENCED BY HOPE AND MINDFULNESS A...

Collins, Amy B.

2010-01-16

227

The influence of institutionalization on the perception of autonomy and quality of life in old people.  

PubMed

Objective To evaluate the influence exercised by institutionalization on the autonomy and perception of quality of life among the institutionalized elderly. Method The study is quasi-experimental (interrupted time series) and longitudinal. The sample is composed for 104 elderly people who went into a three nursing home in Santander, Spain. To assess the quality of life and dependence two scales were used: the Barthel Index and Lawton Index. Results There was an important relationship between autonomy and independence and their deterioration due to their institutionalisation, such as the physical and social aspects. Conclusion It´s important to point out that the dependence of the elderly is a complex phenomenon, which admits many types of intervention, including the customary ones referring to more classic welfare actions which tend to supplant the absence of autonomy in everyday life by facilitating services and attention to make up for this need, without having to resort to institutionalization. PMID:25626500

Cobo, Carmen María Sarabia

2014-12-01

228

Life-History Evolution on Tropidurinae Lizards: Influence of Lineage, Body Size and Climate  

PubMed Central

The study of life history variation is central to the evolutionary theory. In many ectothermic lineages, including lizards, life history traits are plastic and relate to several sources of variation including body size, which is both a factor and a life history trait likely to modulate reproductive parameters. Larger species within a lineage, for example tend to be more fecund and have larger clutch size, but clutch size may also be influenced by climate, independently of body size. Thus, the study of climatic effects on lizard fecundity is mandatory on the current scenario of global climatic change. We asked how body and clutch size have responded to climate through time in a group of tropical lizards, the Tropidurinae, and how these two variables relate to each other. We used both traditional and phylogenetic comparative methods. Body and clutch size are variable within Tropidurinae, and both traits are influenced by phylogenetic position. Across the lineage, species which evolved larger size produce more eggs and neither trait is influenced by temperature components. A climatic component of precipitation, however, relates to larger female body size, and therefore seems to exert an indirect relationship on clutch size. This effect of precipitation on body size is likely a correlate of primary production. A decrease in fecundity is expected for Tropidurinae species on continental landmasses, which are predicted to undergo a decrease in summer rainfall. PMID:21603641

Brandt, Renata; Navas, Carlos A.

2011-01-01

229

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...

230

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

231

Influence of Life-Course Socioeconomic Position on Incident Heart Failure in Blacks and Whites  

PubMed Central

The influence of early-life socioeconomic position (SEP) on incident heart failure in blacks and whites is unknown. The authors examined the relation between early-life SEP and incident, hospitalized heart failure among middle-aged US participants (2,503 black and 8,519 white) in the Atherosclerosis Risk in Communities (ARIC) Study. Early-life SEP indicators assessed included parental education, occupation, and home ownership. From 1987 to 2004, 221 and 537 incident heart failure events were identified in blacks and whites, respectively. In Cox proportional hazards regression, early-life SEP was inversely related to incident heart failure after adjustment for age, gender, and study center (for blacks, hazard ratio (HR) = 1.39, 95% confidence interval (CI): 1.00, 1.95; for whites, HR = 1.32, 95% CI: 1.06, 1.64). Additional adjustment for young and mid-to-older adulthood SEP and established heart failure risk factors attenuated this association towards the null in both blacks and whites. Of the SEP measures, mid-to-older adulthood SEP showed the strongest association with incident heart failure in both blacks (HR = 1.32, 95% CI: 0.90, 1.96) and whites (HR = 1.39, 95% CI: 1.11, 1.75). SEP over the life course is related to the risk of incident heart failure, with SEP later in adulthood having a more prominent role than earlier SEP. PMID:20696652

Roberts, Calpurnyia B.; Couper, David J.; Chang, Patricia P.; James, Sherman A.; Rosamond, Wayne D.; Heiss, Gerardo

2010-01-01

232

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

233

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

234

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

235

Characterisation of juvenile flatfish habitats in the Baltic Sea  

NASA Astrophysics Data System (ADS)

Survival and growth of the earliest life-stages is considered a key factor in determining the abundance of many marine fish species. For flatfishes, the availability of high quality nursery areas is essential for successful recruitment. Regarding the Baltic Sea, there are large gaps in knowledge on factors that influence the distribution of flatfishes during this sensitive stage. To identify the characteristics of important nursery areas in the Baltic for flounder ( Platichthys flesus) and turbot ( Psetta maxima), a field survey with push net sampling was conducted in the northern Baltic proper during autumn 2006. The sampling stations were stratified to cover several different habitat types defined by substrate and wave exposure. Apart from density of young-of-the-year (YOY) flatfishes, a number of ecological characteristics of the habitat were recorded. Physical habitat variables included substrate type, salinity, depth, turbidity, vegetation and habitat structure. Variables describing biotic processes, such as prey availability and abundance of competitors, were also sampled. The relationships between the spatial distribution of species and these ecological characteristics were fitted to presence/absence data of juvenile flatfish using generalized additive models (GAM). The best habitat descriptors for flounder in order of contribution were: substrate, habitat structure, salinity, wave exposure and occurrence of filamentous algae. Positive effects of increasing wave exposure, salinity and structure were detected while a high cover of filamentous algae had a negative effect. Sand and gravel were preferred over soft and stony substrates. For turbot the best habitat descriptors in order of contribution were: occurrence of filamentous algae, substrate and turbidity. Turbot showed a preference for areas with a low cover of filamentous algae, high turbidity and sandy substrate. Prey availability and abundance of competitors were not included in the models, indicating that the distribution of flatfishes at the scales studied (tens of kilometres) is mainly governed by physical habitat properties. These results constitute the basis for future efforts on mapping of essential flatfish habitats in the Baltic Sea.

Florin, Ann-Britt; Sundblad, Göran; Bergström, Ulf

2009-04-01

236

Two-carbon metabolites, polyphenols and vitamins influence yeast chronological life span in winemaking conditions  

PubMed Central

Background Viability in a non dividing state is referred to as chronological life span (CLS). Most grape juice fermentation happens when Saccharomyces cerevisiae yeast cells have stopped dividing; therefore, CLS is an important factor toward winemaking success. Results We have studied both the physical and chemical determinants influencing yeast CLS. Low pH and heat shorten the maximum wine yeast life span, while hyperosmotic shock extends it. Ethanol plays an important negative role in aging under winemaking conditions, but additional metabolites produced by fermentative metabolism, such as acetaldehyde and acetate, have also a strong impact on longevity. Grape polyphenols quercetin and resveratrol have negative impacts on CLS under winemaking conditions, an unexpected behavior for these potential anti-oxidants. We observed that quercetin inhibits alcohol and aldehyde dehydrogenase activities, and that resveratrol performs a pro-oxidant role during grape juice fermentation. Vitamins nicotinic acid and nicotinamide are precursors of NAD+, and their addition reduces mean longevity during fermentation, suggesting a metabolic unbalance negative for CLS. Moreover, vitamin mix supplementation at the end of fermentation shortens CLS and enhances cell lysis, while amino acids increase life span. Conclusions Wine S. cerevisiae strains are able to sense changes in the environmental conditions and adapt their longevity to them. Yeast death is influenced by the conditions present at the end of wine fermentation, particularly by the concentration of two-carbon metabolites produced by the fermentative metabolism, such as ethanol, acetic acid and acetaldehyde, and also by the grape juice composition, particularly its vitamin content. PMID:22873488

2012-01-01

237

Effects of habitat fragmentation by damming on salmonid fishes: lessons from white-spotted charr in Japan  

Microsoft Academic Search

Dam construction has serious consequences, and one of the most serious concerns is the fragmentation of riverine ecosystems.\\u000a We reviewed the influence of habitat fragmentation on white-spotted charr Salvelinus leucomaenis populations. First, habitat fragmentation by damming has serious consequences in terms of alternative life-history strategies.\\u000a Most fish in dammed-off areas do not migrate to the sea and instead become resident

Kentaro Morita; Shoko H. Morita; Shoichiro Yamamoto

2009-01-01

238

From broadscale patterns to fine-scale processes: habitat structure influences genetic differentiation in the pitcher plant midge across multiple spatial scales.  

PubMed

The spatial scale at which samples are collected and analysed influences the inferences that can be drawn from landscape genetic studies. We examined genetic structure and its landscape correlates in the pitcher plant midge, Metriocnemus knabi, an inhabitant of the purple pitcher plant, Sarracenia purpurea, across several spatial scales that are naturally delimited by the midge's habitat (leaf, plant, cluster of plants, bog and system of bogs). We analysed 11 microsatellite loci in 710 M. knabi larvae from two systems of bogs in Algonquin Provincial Park (Canada) and tested the hypotheses that variables related to habitat structure are associated with genetic differentiation in this midge. Up to 54% of variation in individual-based genetic distances at several scales was explained by broadscale landscape variables of bog size, pitcher plant density within bogs and connectivity of pitcher plant clusters. Our results indicate that oviposition behaviour of females at fine scales, as inferred from the spatial locations of full-sib larvae, and spatially limited gene flow at broad scales represent the important processes underlying observed genetic patterns in M. knabi. Broadscale landscape features (bog size and plant density) appear to influence oviposition behaviour of midges, which in turn influences the patterns of genetic differentiation observed at both fine and broad scales. Thus, we inferred linkages among genetic patterns, landscape patterns and ecological processes across spatial scales in M. knabi. Our results reinforce the value of exploring such links simultaneously across multiple spatial scales and landscapes when investigating genetic diversity within a species. PMID:21929541

Rasic, Gordana; Keyghobadi, Nusha

2012-01-01

239

Environmental Contingency in Life History Strategies: The Influence of Mortality and Socioeconomic Status on Reproductive Timing  

PubMed Central

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.

2013-01-01

240

Influence of Functional Movement Rehabilitation on Quality of Life in People with Parkinson’s Disease  

PubMed Central

[Purpose] Parkinson’s disease is one of the most frequent diseases of the central nervous system. Thorough knowledge of reasons for movement defects may contribute to the ability to quality of life at a good level as far as motor abilities are concerned. The aim of the study was to evaluate the influence of functional movement rehabilitation on the degree of intensity of movement symptoms in Parkinson’s disease. [Subjects] The research was carried out in people diagnosed with stage III Parkinson’s disease, according to the Hoehn and Yahr scale classification. [Methods] In order to establish the clinical state of patients, parts I, II, and III of the Unified Parkinson’s Disease Rating Scale, the Schwab and England Activities of Daily Living scale, and the quality of life in Parkinson’s disease questionnaire were applied. The intervention group took part in 60 minutes of functional movement rehabilitation twice a week for a period of 15 weeks. The main emphasis was placed on the ability to cope with everyday activities. [Results] A significant difference in scores for the given scales between before and after research the intervention period was observed in the intervention group. [Conclusion] The obtained results revealed positive that the influence of applied rehabilitation program had a positive influence on the degree of intensity of movement symptoms in people with Parkinson’s disease. PMID:25276010

Cholewa, Joanna; Gorzkowska, Agnieszka; Szepelawy, Michal; Nawrocka, Agnieszka; Cholewa, Jaroslaw

2014-01-01

241

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

242

Influence of Sleep Disturbances on Quality of Life of Iranian Menopausal Women  

PubMed Central

Background. Subjective sleep disturbances increase during menopause. Some problems commonly encountered during menopause, such as hot flushes and sweating at night, can cause women to have difficulty in sleeping. These complaints can influence quality of life of menopausal women. Methods. This cross-sectional study was performed on menopausal women attending health centers in Qazvin for periodic assessments. We measured excessive daytime sleepiness by Epworth sleepiness scale (ESS), obstructive sleep apnea (OSA) by the Berlin questionnaire, and insomnia by the insomnia severity index (ISI). We evaluate quality of life by the Menopause specific quality of life questionnaire (MENQOL). Results. A total of 380 menopausal women entered the study. Mean age of participated women was 57.6 ± 6.02. Mean duration of menopause was 6.3 ± 4.6. The frequency of severe and moderate insomnia was 8.4% (32) and 11.8% (45). Severe daytime sleepiness (ESS???10) was present in 27.9% (80) of the participants. Multivariate analytic results show that insomnia and daytime sleepiness have independent negative impact on each domain and total score of MENQOL questionnaire. Conclusion. According to our findings, EDS and insomnia are frequent in menopausal women. Both EDS and insomnia have significant quality of life impairment. PMID:24286070

Yazdi, Zohreh; Sadeghniiat-Haghighi, Khosro; Ziaee, Amir; Elmizadeh, Khadijeh; Ziaeeha, Masomeh

2013-01-01

243

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

244

Quality of life and diabetes knowledge of young persons with type 1 diabetes: Influence of treatment modalities and demographics  

Microsoft Academic Search

ObjectiveThe primary objective of this descriptive study was to assess the perception of quality of life and diabetes knowledge among young persons with type 1 diabetes. The secondary objectives were to examine the influence of treatment modality (continuous subcutaneous insulin infusion vs multiple daily injections) and demographics on quality of life and diabetes knowledge of these young persons and to

Kelli J. O’Neil; Satya S. Jonnalagadda; Barbara L. Hopkins; Jana R. Kicklighter

2005-01-01

245

Life cycle and behavioural assessments of the influence of substrate particle size on Chironomus tentans (Diptera: Chironomidae) in laboratory assays  

Microsoft Academic Search

Identifying and understanding factors that affect interpretation of sediment toxicity is critical to the development and standardization of sediment test methods. In this study, we evaluated the influence of sediment particle size on survival, growth, emergence, and reproduction in a life cycle test with the midge Chironomus tentans, and on substrate selection behaviour of C. tentans larvae. In the life

Paul K. Sibley; Duane A. Benoit; Gerald T. Ankley

1997-01-01

246

Identification of Heredity Kernels and Their Influence on the Life Time of Glass/Polyester Composites  

NASA Astrophysics Data System (ADS)

One of the major problems encountered in prediction of hereditary viscoelastic behavior of polymeric composites is the determination of heredity kernels. This issue comes down to identification of the model characterizing the viscoelastic properties of these materials. The purpose of this work is to propose a model for prediction of viscoelastic nonlinear behavior of laminate composite with polyester matrix, through the study and analysis of heredity kernels and their influence on the life time of this material. Identification of this model required experimental determination at room temperature, of viscoelastic parameters of heredity kernels by macroscopic approach. These data provide predictive tools for establishment of the life time and long term stress limit under static complex loading for this type of material.

Olodo, E. T.; Adjovi, E. C.; Adanhounme, V.

2014-11-01

247

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

248

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

10/24/13 nsf.gov - National Science Foundation (NSF) News - Habitat research methods give a new.gov/news/news_summ.jsp?cntn_id=129355 1/1 News From the Field HABITAT RESEARCH METHODS GIVE A NEW PEEK AT TIGER LIFE

249

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

2015-01-01

250

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

251

Influence of beaver impoundments on vegetative composition, and modeling habitat suitability as a tool for wildlife management and conservation.  

E-print Network

??Beavers (Castor canadensis) can have dramatic effects on vegetative communities through impounding streams and wetlands. These alterations may influence rare plant species where beaver create… (more)

Bonner, Jerri LeAnne.

2005-01-01

252

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

253

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.

254

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.

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

2014-01-01

255

Life Stage Influences on U.S. South Asian Women's Physical Activity.  

PubMed

Abstract Purpose . South Asian (SA) women in the United States report extremely low rates of leisure time physical activity (PA) compared with women in other ethnic minority groups. This study explored SA women's perspectives on PA during different life stages. Design . This is a community-based participatory research study that used focus groups. Setting . The study setting was a community-based organization that provides social services to SA immigrants in Chicago, Illinois. Participants . The study team conducted six focus groups (in English and Hindi) with 42 SA women, ages 18 to 71 years. Method . A semistructured interview guide was used to foster discussion about perceptions of, barriers to/facilitators of, and suggestions for PA programs. Discussions were transcribed and independently coded by two reviewers using thematic content analysis and guided by a coding scheme that was developed a priori. Results . Participants said that different life stages strongly influenced their PA. PA decreased after marriage and having children. Chronic diseases constrained older women from more vigorous PA. Barriers to PA among younger women were family disapproval and perceptions that PA is unnecessary if you are "skinny." Women agreed that PA is not a priority within the culture, and that interventions must take into account cultural, religious, and family context. Conclusion . Sociocultural norms, family constraints, and lack of awareness about the benefits of PA strongly influenced PA among SA women. Culturally salient intervention strategies might include programs in trusted community settings where women can exercise in women-only classes with their children, and targeted education campaigns to increase awareness about the benefits of PA across life stages. PMID:24717067

Dave, Swapna S; Craft, Lynette L; Mehta, Promila; Naval, Shilpa; Kumar, Santosh; Kandula, Namratha R

2015-01-01

256

Antihypertensive therapy and quality of life. Influence of blood pressure reduction, adverse events, and prior antihypertensive therapy.  

PubMed

Quality of life is an important attribute of antihypertensive therapy. Previous studies have not addressed the importance of a patient's prior pharmacotherapy on quality of life, which may serve as the basis of reference for a new therapy. Nor have previous studies compared commonly used quality of life instruments for consistency, or investigated whether improvement or worsening of quality of life correlates with adverse events or blood pressure reduction. Two hundred eighteen hypertensive patients with diastolic blood pressure (95 to 114 mm Hg) after a 4- to 5-week placebo washout period were enrolled in a randomized double-blind, parallel group dose-escalation trial to compare the effects of amlodipine (2.5 to 10 mg), bisoprolol (2.5 to 10 mg)/hydrochlorothiazide (HCTZ) 6.25, and enalapril (5 to 20 mg) on blood pressure, adverse events, and quality of life. Three quality of life instruments (General Well-Being Index, Vital Signs Quality of Life, Zung Self-Rating Depression Scale) were administered during original therapy, after placebo washout, and after 12 weeks of optimally titrated clinical trial pharmacotherapy. Our results demonstrated that removal from prior therapy had no detectable influence on subsequent evaluation of quality of life. The three quality of life instruments were consistent with the changes observed with the three therapies: a trend toward better quality of life with amlodipine and bisoprolol/HCTZ. Adverse events, but not systolic or diastolic blood pressure reduction correlated directly with changes in quality of life. PMID:8879341

Weir, M R; Prisant, L M; Papademetriou, V; Weber, M A; Adegbile, I A; Alemayehu, D; Lefkowitz, M P

1996-09-01

257

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

258

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.

259

Depressive mood mediates the influence of social support on health-related quality of life in elderly, multimorbid patients  

PubMed Central

Background It is not well established how psychosocial factors like social support and depression affect health-related quality of life in multimorbid and elderly patients. We investigated whether depressive mood mediates the influence of social support on health-related quality of life. Methods Cross-sectional data of 3,189 multimorbid patients from the baseline assessment of the German MultiCare cohort study were used. Mediation was tested using the approach described by Baron and Kenny based on multiple linear regression, and controlling for socioeconomic variables and burden of multimorbidity. Results Mediation analyses confirmed that depressive mood mediates the influence of social support on health-related quality of life (Sobel’s p?influence of depressive mood (??=??0.341, p?life is greater than the influence of multimorbidity (??=??0.234, p?influences health-related quality of life, but this association is strongly mediated by depressive mood. Depression should be taken into consideration in research on multimorbidity, and clinicians should be aware of its importance when caring for multimorbid patients. Trial registration ISRCTN89818205 PMID:24708815

2014-01-01

260

Abstract--Life history aspects of larval and, mainly, juvenile spotted seatrout  

E-print Network

Everglades res toration plans (i.e. increased freshwater flows) could influence spotted seatrout vital rates distri in Florida Bay and spends its entire life bution, growth, spawning, and diet of history within of the standing of the entire life history of this juvenile habitats and their diets (Het- valuable species

261

Habitat Persistence Underlies Intraspecific Variation in the Dispersal Strategies of Planthoppers  

E-print Network

Habitat Persistence Underlies Intraspecific Variation in the Dispersal Strategies of Planthoppers HABITAT PERSISTENCE UNDERLIES INTRASPECIFIC VARIATION IN THE DISPERSAL STRATEGIES OF PLANTHOPPERS1 ROBERTF temporary habitats, and life history theorists have often hypothesized an inverse relationship between

Behmer, Spencer T.

262

Influence of personal character on quality of life of patients with esophageal cancer in north Henan province and influencing factors.  

PubMed

The aim of this study was to investigate QoL (quality of life) of patients with esophageal cancer in northern Henan province, China, and to accurate evaluate and reflect the relationship between patient characteristics and QoL. In the high risk area of esophageal cancer in the north of Henan province, 735 patients with esophageal cancer were investigated. The Eysenck personality questionnaire (EPQ) and QoL were analyzed by using the questionnaire of general situation, EPQ, QLQ-C30 and QLQ-OES18. The effects of personal character on the QoL of esophageal carcinoma patients were analyzed by SPSS 11.0 software. The QoL of esophageal cancer patients in Northern Henan region was significantly affected by character. The difference between choleric and type of melancholic temperament types was significant (P<0.01), also in OESEAT, OESTA, OESCO and OESSP (P<0.05). Differences in personal character can thus influence the quality of esophageal cancer patient lives. PMID:23317193

Lin, Jian-Ying; Wang, Ming-Sheng; Dong, Liang-Peng; Xu, Da-Wei; Wang, Ying; Li, Xue-Liang; Li, Xiu-Min

2012-01-01

263

The Presence of and Invasive Macrophyte (Phragmites australis) Does not Influence Juvenile Fish Habitat Use in a Freshwater Estuary  

Microsoft Academic Search

I evaluated the short-term influence of the presence of the invasive macrophyte Phragmites australis on fish use in Old Woman Creek, a freshwater estuary connected intermittently to Lake Erie in northcentral Ohio. With minnow traps, trap nets, and light traps I sampled juvenile fish in two areas of the estuary, one dominated by P. australis and the other dominated by

D. Derek Aday

2007-01-01

264

Evaluating the influence of macrophytes on algal and bacterial production in multiple habitats of a freshwater wetland  

Microsoft Academic Search

Algal 14 C uptake and bacterial 3 H leucine incorporation were measured over 20 months to assess the influence of macrophytes on the spatial distribution and magnitude of microbial production and the relative importance of algae versus macrophytes to whole-system energy flow in a southeastern U.S. wetland. Algal and bacterial produc- tion were determined for water column and plant-, sediment-,

Emily H. Stanley; Mark D. Johnson; Amelia K. Ward

2003-01-01

265

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

266

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

267

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

268

Factors influencing psychological status and quality of life in patients with implantable cardioverter-defibrillators.  

PubMed

Various mental and social problems can negatively impact the quality of life and overall health in patients with implantable cardiac defibrillators (ICD). In this report, we review and summarize the main studies and research related to this topic. Depression, anxiety, panic attacks, stress and post-traumatic stress are the most common symptoms of ICD-related disorders that can negatively impact mental status. Factors than can influence the impact of these psychological disorders include socio-demographic variables (younger age, gender, and employment), variables related to the ICD (number of ICD shocks, generator size, time from ICD implant, etc.) and psycho-social variables (negative coping strategies, lack of social support and personality type). Fortunately, these disorders, and their symptoms, can be prevented, treated or managed, if recognized. PMID:25433355

Kajanová, Alena; Bulava, Alan; Eisenberger, Martin

2014-11-30

269

Distribution of motor impairment influences quality of life in Parkinson's disease.  

PubMed

We evaluated the relationship between upper extremity (UE) and lower extremity (LE) motor impairments in Parkinson's disease (PD) to overall disability and quality of life (QoL) measures. A total of 639 patients who were diagnosed with idiopathic PD were administered the Unified Parkinson's Disease Rating Scale (UPDRS), QoL, activities of daily living (ADL), and behavioral scales. Composite UE and LE scores from the motor section of the UPDRS were correlated with ADL, QoL, and behavioral measurement scores while controlling for disease duration. Patients with greater UE and LE motor impairments had lower QoL scores. However, LE impairments had a greater influence than UE impairments across all QoL measures. PMID:18546324

Stewart, Kim C; Fernandez, Hubert H; Okun, Michael S; Jacobson, Charles E; Hass, Chris J

2008-07-30

270

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

271

Prevalence of Widespread Pain and Its Influence on Quality of Life: Population Study in Korea  

PubMed Central

The objective of this study was to examine the prevalence and risk factors for widespread pain and its influence on quality of life in residents of Korean communities. A rural and an urban community were selected, and 5,037 subjects were surveyed. Participants were asked if they had pain, aching, or stiffness in any of their joints on most days. Widespread pain was defined as pain above the waist, below the waist, on both sides of the body and in the axial region. The prevalence of widespread pain was 12% (16.2% and 5.5% in females and males, respectively). It was more frequent among females and increased with age in both genders. Age, female gender, and the presence of hand or knee arthritis were significantly associated with widespread pain after multivariate analysis. Except for mental health, all the items in the SF-12 were adversely affected in the widespread pain group after adjustment for confounding factors. Our findings show that the prevalence of widespread pain among residents of Korean communities is comparable to that reported among Caucasians. The significantly worse quality of life among subjects with widespread pain suggests that it may cause major health issues in the aging population. PMID:22219608

Cho, Nam Han; Kim, Inje; Lim, Seung Hun

2012-01-01

272

Discomfort associated with fixed orthodontic appliances: determinant factors and influence on quality of life  

PubMed Central

Objective To investigate the determinant factors of discomfort attributed to the use of fixed orthodontic appliance and the effect on the quality of life of adolescents. Material and Methods Two hundred and seventy-two individuals aged between 9 and 18 years old, enrolled in public and private schools and undergoing orthodontic treatment with fixed appliance participated in this cross-sectional study. The participants were randomly selected from a sample comprising 62,496 individuals of the same age group. Data was collected by means of questionnaires and an interview. Discomfort intensity and bio-psychosocial variables were assessed using the Oral Impact on Daily Performance questionnaire. Self-esteem was determined using the Global Negative Self-Evaluation questionnaire. Statistical analysis involved the chi-square test and both simple and multiple Poisson regression analyses. Results Although most individuals did not present discomfort, there was a prevalence of 15.9% of impact on individuals' daily life exclusively due to the use of fixed orthodontic appliance . Age [PR: 3.2 (95% CI: 1.2-8.5)], speech impairment [PR: 2.2 (95% CI: 1.1-4.6)], poor oral hygiene [PR: 2.4 (95% CI: 1.2-4.8)] and tooth mobility [PR: 3.9 (95% CI: 1.8-8.1)] remained independently associated with a greater prevalence of discomfort (P ? 0.05). Conclusions Discomfort associated with the use of fixed orthodontic appliances exerted a negative influence on the quality of life of the adolescents comprising the present study. The determinants of this association were age, poor oral hygiene, speech impairment and tooth mobility. PMID:25162573

Marques, Leandro Silva; Paiva, Saul Martins; Vieira-Andrade, Raquel Gonçalves; Pereira, Luciano José; Ramos-Jorge, Maria Letícia

2014-01-01

273

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

274

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

275

Growth history and intrinsic factors influence risk assessment at a critical life transition for a fish  

NASA Astrophysics Data System (ADS)

Making the appropriate decision in the face of predation risk dictates the fate of prey, and predation risk is highest at life history boundaries such as settlement. At the end of the larval phase, most coral reef fishes enter patches of reef containing novel predators. Since vision is often obscured in the complex surroundings, chemical information released from damaged conspecific is used to forewarn prey of an active predator. However, larvae enter the reef environment with their own feeding and growth histories, which will influence their motivation to feed and take risks. The present study explored the link between recent growth, feeding history, current performance and behavioural risk taking in newly settling stages of a coral reef damselfish ( Pomacentrus amboinensis). Older and larger juveniles in good body condition had a stronger response to chemical alarm cues of injured conspecifics; these fish spent a longer time in shelter and displayed a more dramatic decrease in foraging behaviour than fish in lower body condition. Feeding experiments supported these findings and emphasized the importance of body condition in affecting risk assessment. Evidently, larval growth history and body condition influences the likelihood of taking risks under the threat of predation immediately after settlement, thereby affecting the probability of survival in P. amboinensis.

Lönnstedt, O. M.; McCormick, M. I.

2011-09-01

276

Alcohol Response and Consumption in Adolescent Rhesus Macaques: Life History and Genetic Influences  

PubMed Central

The use of alcohol by adolescents is a growing problem and has become an important research topic in the etiology of the alcohol use disorders. A key component of this research has been the development of animal models of adolescent alcohol consumption and alcohol response. Due to their extended period of adolescence, rhesus macaques are especially well-suited for modeling alcohol-related phenotypes that contribute to the adolescent propensity for alcohol consumption. In this review, we discuss studies from our laboratory that have investigated both the initial response to acute alcohol administration and the consumption of alcohol in voluntary self-administration paradigms in adolescent rhesus macaques. These studies confirm that adolescence is a time of dynamic change both behaviorally and physiologically, and that alcohol response and alcohol consumption are influenced by life history variables such as age, sex, and adverse early experience in the form of peer-rearing. Furthermore, genetic variants that alter functioning of the serotonin, endogenous opioid, and corticotropin releasing hormone systems are shown to influence both physiological and behavioral outcomes, in some cases interacting with early experience to indicate gene by environment interactions. These findings highlight several of the pathways involved in alcohol response and consumption, namely reward, behavioral dyscontrol, and vulnerability to stress, and demonstrate a role for these pathways during the early stages of alcohol exposure in adolescence. PMID:20113875

Schwandt, Melanie L.; Lindell, Stephen G.; Chen, Scott; Higley, J. Dee; Suomi, Stephen J.; Heilig, Markus; Barr, Christina S.

2009-01-01

277

Ghosts of habitats past: Contribution of landscape change to current habitats used by shrubland birds  

USGS Publications Warehouse

Models of habitat associations for species often are developed with an implicit 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 landscapes undergoing predominantly large-scale, radical, and unidirectional habitat change because wildfires are converting shrublands into expanses of exotic annual grasslands. We used data from field surveys and satellite image analyses in a series of redundancy analyses to partition variances and to determine the relative contribution of habitat change and current landscapes. Although current habitats explained a greater proportion of total variation, changes in habitat and measures of habitat richness and texture also contributed to variation in abundance of Horned Larks (Eremophila alpestris), Brewera??s Sparrows (Spizella breweri), and Sage Sparrows (Amphispiza belli). Abundance of birds was insensitive to scale for nonspatial habitat variables. In contrast, spatial measures of habitat richness and texture in the landscape were significant only at large spatial scales. Abundance of Horned Larks, Western Meadowlarks (Sturnella neglecta), and Brewera??s Sparrows, but not Sage Thrashers (Oreoscoptes montanus) or Sage Sparrows, was positively correlated with changes toward stable habitats. Because dominant habitat changes were toward less stable conditions, regional declines of those birds in shrubsteppe habitats reflect current landscapes as well as the history, magnitude, and trajectory of habitat change.

Knick, Steven T.; Rotenberry, J.T.

2000-01-01

278

The use of habitat mosaics by terrestrial vertebrate fauna: implications for conservation and management  

Microsoft Academic Search

Many species of vertebrates require multiple habitats to obtain different resources at different stages of their life-cycles. Use of habitat mosaics takes place on a variety of spatial and temporal scales, from a daily requirement for adjacent habitats to seasonal use of geographically separated environments. Mosaics of habitats are also required in some species to allow ontogenetic habitat shifts, while

B. S. LAW; C. R. DICKMAN

1998-01-01

279

Factors influencing quality of life in patients during radiotherapy for head and neck cancer  

PubMed Central

Introduction Radiotherapy (RT) in combination with chemotherapy is a standard of care for patients with head and neck squamous cell carcinoma (HNSCC). The RT is associated with side effects, which impact on quality of life (QoL). Thus, the aim of this prospective longitudinal study was to investigate the impact of RT on the QoL of patients with HNSCC during RT. Material and methods From September 2008 to February 2010, 205 patients with locally advanced HNSCC were enrolled. The data pertaining to their QoL were collected using the EORTC QLQ-C30 and the EORTC Head and Neck Module (QLQ-H&N35) and then all items were transformed to a 0-100 scale according to the guidelines of the EORTC. The following clinical factors were chosen to study their potential influence on the QoL; site of primary, clinical stage, and methods of therapy: RT vs. chemoradiotherapy (CRT). Additionally, the sociodemographic factors (age, gender, education, habit of smoking) were studied. Results Deterioration of almost all scales and items in the QLQ-C30 and QLQ-H&N35 questionnaire were noted at the end of RT. The following factors negatively influenced the QoL: age < 60 years (p < 0.05), female gender (p < 0.05), habit of smoking (p < 0.01), advanced clinical stage (III and IV) (p < 0.05), site of primary (larynx, hypopharynx) (p < 0.01), and CRT (p < 0.01). Conclusions Our study showed that RT significantly negatively influenced QoL at the end of the RT course. Additionally, this study demonstrated that age, gender, smoking habit, tumor site, and clinical stage of disease showed a significant effect on the QoL of HNSCC patients during RT. PMID:25624853

?mijewska-Tomczak, Ma?gorzata; Olek-Hrab, Karolina; Hojan, Katarzyna; Golusi?ski, Wojciech; Ruci?ska, Anna; Adamska, Anna

2013-01-01

280

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

281

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.

Aquariums, Association O.

2009-01-01

282

WILDLIFE HABITAT  

EPA Science Inventory

Habitat change statistics were used to estimate the effects of alternative future scenarios for agriculture on non-fish vertebrate diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future scenarios w...

283

When giants turn up: sighting trends, environmental influences and habitat use of the manta ray Manta alfredi at a coral reef.  

PubMed

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

284

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

285

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

286

Food-plant families of British insects and mites: the influence of life form and plant family  

Microsoft Academic Search

The dissimilarities between 107 British plant families with respect to the insect and mite species which feed on them were analysed using a principal co-ordinates analysis. The relationships between the plant families were strongly influenced by the plant life forms. Major groups were woody plants (trees and shrubs), aquatic plants and herbs. A wet to dry gradient was distinguished, as

Lena K. Ward; A. Hackshaw; R. T. Clarke

1995-01-01

287

An obesity provoking behaviour negatively influences young normal weight subjects' health related quality of life and causes depressive symptoms  

Microsoft Academic Search

In many parts of the world the prevalence of a sedentary lifestyle in combination with high consumption of food has increased, which contributes to increased risk for becoming overweight. Our primary aim was, in an intervention, to examine the influence on health related quality of life (HRQoL) and mood in young normal weight subjects of both sexes, when adopting an

Åsa Ernersson; Gunilla Hollman Frisman; Anneli Sepa Frostell; Fredrik H. Nyström; Torbjörn Lindström

2010-01-01

288

Influences of post weld heat treatment on fatigue life prediction of strength mis-matched HSLA steel welds  

Microsoft Academic Search

Welding of High Strength Low Alloy Steels (HSLA) involve usage of low, even and high strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler materials. In the present investigation, the influences of post weld heat treatment (PWHT) on fatigue life prediction of under matched (UM), even matched

S. Ravi; V. Balasubramanian; S. Nemat Nasser

2005-01-01

289

Influences of welding processes on fatigue life of cruciform joints of pressure vessel grade steels containing LOP defects  

Microsoft Academic Search

The influences of two welding processes, namely, shielded metal arc welding (SMAW) and flux cored arc welding (FCAW), on fatigue life of cruciform joints, containing lack of penetration (LOP) defects, have been studied. Load carrying cruciform joints were fabricated from high strength, quenched and tempered steels of pressure vessel (ASTM 517 ‘F’) grade. Fatigue crack growth experiments were carried out

V Balasubramanian; B Guha

2000-01-01

290

Influence of Interfacial Bond Strength on Fatigue Life and ThermoMechanical Behavior of a Particulate Composite: An Experimental Study  

Microsoft Academic Search

Experimental studies conducted on a particular cast acrylic composite demonstrate the significant influence of the interfacial bond strength between filler particles and the polymer matrix on the fatigue life, and mechanical properties. The composite studied in this project is composed of a ductile matrix, which is lightly cross-linked poly-methyl methacrylate (PMMA) and hard, brittle alumina trihydrate (ATH) agglomerate particle filler.

C. Basaran; S. Nie; C. S. Hutchins; H. Ergun

2008-01-01

291

Prospective association between negative life events and initiation of sexual intercourse: the influence of family structure and family income.  

PubMed

Objectives. We examined the prospective association between negative life events and time to initiation of sexual intercourse and the influence of family structure and family income on this association. Methods. We followed up a randomly selected sample (n?=?649) of ethnically diverse parents and their children aged 12 to 17 years over a 5-year period. We conducted Cox proportional hazards regression analysis to examine the relation between negative life events and time to initiation of sexual intercourse. Family structure and family income were assessed as confounders. Results. Negative life events were significant predictors of time to initiation of sexual intercourse in adolescents. After controlling for demographic variables, youths reporting 1 negative life event had a hazard of initiation of sexual intercourse 1.40 times greater and youths reporting 2 or more negative life events had a hazard of initiation of sexual intercourse 1.61 times greater compared with youths reporting no negative life events. Family structure and family income were not significant confounders of the relation between initiation of sexual intercourse and negative life events. Conclusions. Interventions to prevent initiation of sexual intercourse should focus on youths with recent negative life events, regardless of family income and structure. PMID:25602885

Cheney, Marshall K; Oman, Roy F; Vesely, Sara K; Aspy, Cheryl B; Tolma, Eleni L; John, Robert

2015-03-01

292

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

2014-11-21

293

Water quality and benthic macroinvertebrate communities in karst landscapes of North Island, New Zealand: influences of water sources, habitat type and anthropogenic disturbances  

Microsoft Academic Search

In karst landscapes, aquatic habitats differ in terms of the relative contributions of different water sources (allogenic surface stream vs autogenic karst groundwater) and their geomorphology. Benthic macroinvertebrate community structure in these habitats is likely to vary in response to this heterogeneity, as well as to the physicochemical differences between water flowing through pasture vs native forest dominated catchments. Surveys

DJ Reid; Scarsbrook; AE Wright-Stow; KSS van Houte-Howes; K Joy

2012-01-01

294

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.

Coffey, Audrey L.; Sterling, Donna R.

2003-09-01

295

A quantitative study of factors influencing quality of life in rural Mexican women diagnosed with HIV.  

PubMed

This quantitative study explored the level of Quality of Life (QoL) in indigenous Mexican women and identified psychosocial factors that significantly influenced their QoL, using face-to-face interviews with 101 women accessing care in an HIV clinic in Oaxaca, Mexico. Variables included demographic characteristics, levels of depression, coping style, family functioning, HIV-related beliefs, and QoL. Descriptive statistics were used to analyze participant characteristics, and women's scores on data collection instruments. Pearson's R correlational statistics were used to determine the level of significance between study variables. Multiple regression analysis examined all variables that were significantly related to QoL. Pearson's correlational analysis of relationships between Spirituality, Educating Self about HIV, Family Functioning, Emotional Support, Physical Care, and Staying Positive demonstrated positive correlation to QoL. Stigma, depression, and avoidance coping were significantly and negatively associated with QoL. The final regression model indicated that depression and avoidance coping were the best predictor variables for QoL. PMID:24759058

Holtz, Carol; Sowell, Richard; VanBrackle, Lewis; Velasquez, Gabriela; Hernandez-Alonso, Virginia

2014-01-01

296

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

297

Habitat and scale shape the demographic fate of the keystone sea urchin Paracentrotus lividus in Mediterranean macrophyte communities.  

PubMed

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

298

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

299

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...

300

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

301

Bird Assemblages in Patchy Woodlands: Modeling the Effects of Edge and Matrix Habitats  

Microsoft Academic Search

As habitats become more fragmented, understanding landscape-level effects ,on habitat quality becomes increasingly important. These effects include factors intrinsic to the habitat fragments, such as vegetation cover and structure, and extrinsic factors, such as the modifying influences of surrounding (matrix) habitats. We develop a spatial model, the Effective Area Model (EAM), that predicts the effects of matrix habitats on species

Thomas D. Sisk; Nick M. Haddad; Paul R. Ehrlich

1997-01-01

302

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

303

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

304

Influences on Employee Perceptions of Organizational Work-Life Support: Signals and Resources  

ERIC Educational Resources Information Center

This study examined predictors of employee perceptions of organizational work-life support. Using organizational support theory and conservation of resources theory, we reasoned that workplace demands and resources shape employees' perceptions of work-life support through two mechanisms: signaling that the organization cares about their work-life…

Valcour, Monique; Ollier-Malaterre, Ariane; Matz-Costa, Christina; Pitt-Catsouphes, Marcie; Brown, Melissa

2011-01-01

305

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

306

Great Lakes wetlands as amphibian habitats: A review  

Microsoft Academic Search

Amphibians are highly adapted for life in wetland habitats. They form a major component of wetland faunas, and being both prey and predator, they are important in ecosystem functioning. Wetlands provide aquatic habitats that amphibians require for breeding, development, foraging, hibernation and refuge, and they form an interface with essential adjacent upland habitat. The size and type of wetlands as

S. J. Hecnar

2004-01-01

307

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

308

RESTORATION OF STREAM PHYSICAL HABITAT AND FOOD RESOURCES: INFLUENCE ON JUVENILE COHO GROWTH AND SALMON DERIVED NUTRIENT INCORPORATION IN COASTAL OREGON STREAMS  

EPA Science Inventory

ABSTRACT - Stream restoration in Western Oregon and Washington includes physical habitat improvement and salmon carcass additions. However, few studies examine the effects of carcass placement on juvenile fish in western Oregon, and in particular the interaction with physical hab...

309

Physical habitat template of lotic systems: Recovery in the context of historical pattern of spatiotemporal heterogeneity  

Microsoft Academic Search

Spatial and temporal environmental heterogeneity in lotic ecosystems can be quantitatively described and identified with characteristic\\u000a levels of ecological organization. The long-term pattern of physicochemical variability in conjunction with the complexity\\u000a and stability of the substratum establishes a physical habitat template that theoretically influences which combinations of\\u000a behavioral, physiological and life history characteristics constitute appropriate “ecological strategies” for persistence\\u000a in

N. LeRoy Poff; J. V. Ward

1990-01-01

310

Changes in habitat heterogeneity alter marine sessile benthic communities.  

PubMed

Habitat heterogeneity is considered an important mechanism influencing diversity patterns in spatially structured habitats. However, spatial heterogeneity is not static and it can change along temporal scales. These changes, whether gradual or rapid, have the potential of forcing species extinctions or facilitating the introduction of nonnative species. Here, we present modeling results that show how changes in spatial heterogeneity over several generations can produce strong changes in benthic species composition residing in eastern Long Island Sound, USA. For many benthic species, hard substrate is a limiting resource which can vary in availability among different coastal areas. We modeled gradual changes from a heterogeneous landscape (mimicking patches of natural hard and soft substrate) to a homogenous one (analogous to a fully developed coast with hard, manmade substrate) and followed the abundance and distribution patterns of species possessing four different life histories. We also modeled changes from homogeneous to heterogeneous landscapes. We found that as regions become more homogeneous, species extinctions become more frequent and poor dispersers dominate locally. In contrast, as habitats become more heterogeneous, species distributing across localities leads to regional species coexistence and fewer extinctions. These results suggest that focusing on changing habitat heterogeneity can be a useful management strategy to prevent poor dispersing species, such as invasive ascidians, from driving communities to monocultures. PMID:21639055

Munguia, Pablo; Osman, Richard W; Hamilton, John; Whitlatch, Robert; Zajac, Roman

2011-04-01

311

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

312

Identification of main influencing factors of life cycle CO 2 emissions from the integrated steelworks using sensitivity analysis  

Microsoft Academic Search

The amount of CO2 emissions from steelworks accounts for a great share of the total CO2 emissions from industry in China. Thus, reducing CO2 emissions from steelworks is urgent for China's environmental protection and sustainable development. This study aims at identifying factors that influence CO2 emissions from steelworks and proposing measures to reduce CO2 emissions. The life cycle inventory (LCI)

Zhijia Huang; Xiao Ding; Hao Sun; Siyue Liu

2010-01-01

313

Influence of Spirituality on Cool Down Reactions, Work Engagement, and Life Satisfaction in Anthroposophic Health Care Professionals  

PubMed Central

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 (R2 = 0.20). In contrast, their life satisfaction was explained best (R2 = 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.

Glöckler, Michaela; Heusser, Peter

2015-01-01

314

The influence of life-history strategy on genetic differentiation and lineage divergence in darters (Percidae: Etheostomatinae).  

PubMed

Recent studies determined that darters with specialized breeding strategies can exhibit deep lineage divergence over fine geographic scales without apparent physical barriers to gene flow. However, the extent to which intrinsic characteristics interact with extrinsic factors to influence population divergence and lineage diversification in darters is not well understood. This study employed comparative phylogeographic and population genetic methods to investigate the influence of life history on gene flow, dispersal ability, and lineage divergence in two sympatric sister darters with differing breeding strategies. Our results revealed highly disparate phylogeographic histories, patterns of genetic structure, and dispersal abilities between the two species suggesting that life history may contribute to lineage diversification in darters, especially by limiting dispersal among large river courses. Both species also showed striking differences in demographic history, indicating that extrinsic factors differentially affected each species during the Pleistocene. Collectively, our results indicate that intrinsic and extrinsic factors have influenced levels of gene flow among populations within both species examined. However, we suggest that life-history strategy may play a more important role in lineage diversification in darters than previously appreciated, a finding that has potentially important implications for understanding diversification of the rich North American freshwater fish fauna. PMID:25130551

Fluker, Brook L; Kuhajda, Bernard R; Harris, Phillip M

2014-11-01

315

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

316

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

317

Influence of density dependence on the detection of trends in unobserved life-history stages  

Microsoft Academic Search

In many species, certain life-history stages are difficult or impossible to observe directly, hampering management. Often more easily observed stages are mon- itored instead, but the extent to which various forms of uncertainty cloud our ability to discern trends in one critical life-history stage by observing another is poorly studied. We develop a stochastic simulation model for threatened Califor- nia

K. Shea; N. Wolf; M. Mangel

2006-01-01

318

Life Satisfaction in Early Adolescence: Personal, Neighborhood, School, Family, and Peer Influences  

ERIC Educational Resources Information Center

Drawing from an ecological assets framework as well as research and theory on positive youth development, this study examined the relationship of early adolescents' satisfaction with life to trait optimism and assets representing the social contexts in which early adolescents spend most of their time. Self-reports of satisfaction with life

Oberle, Eva; Schonert-Reichl, Kimberly A.; Zumbo, Bruno D.

2011-01-01

319

Societal Discounting of Health Effects in Cost-Effectiveness Analyses: The Influence of Life Expectancy  

Microsoft Academic Search

Background: Increasing life expectancy and decreasing marginal valuation of additional QALYs over time may serve as a basis for discounting future health effects from a societal perspective. Therefore, we tested the hypothesis that societal time preference for health is related to perceived future life expectancy. Methods: A sample of 223 people from the general population prioritised healthcare programmes with differential

Suzanne Polinder; Willem Jan Meerding; Job van Exel; Werner Brouwer

2005-01-01

320

The Influence of Major Life Events on Economic Attitudes in a World of Gene-Environment Interplay.  

PubMed

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

2013-10-01

321

Channel dynamics and habitat complexity in a meandering, gravel-bed river  

NASA Astrophysics Data System (ADS)

River channel dynamics play an important role in creating and maintaining diverse habitat conditions for multiple life stages of aquatic organisms. As a result, many river restoration projects seek to re-establish ecosystems in which an enhanced degree of habitat complexity is sustained through natural fluvial processes of flow, sediment transport, and channel change. Few field cases have effectively quantified the evolution of channel morphology and habitat complexity in restored rivers, however, and the outcomes of restoration actions remain difficult to predict. Our objective was to quantify the extent to which morphology, flow complexity and salmonid spawning and rearing habitat develop from the simplified initial conditions commonly observed in re-configured meandering channels. Using a time-series of topographic data, we measured rates of morphologic change in a recently restored gravel-bed reach of the Merced River, California, USA. We constructed two-dimensional (2D) hydrodynamic models to quantify how the evolving morphology influenced hydraulic conditions, flow complexity and suitability for Chinook salmon spawning and rearing. Following two large flood events, point bar development led to order-of-magnitude increases in modeled flow complexity, as quantified via the metrics of kinetic energy gradient, vorticity and hydraulic strain. On a bend-averaged scale, morphologic changes produced up to a two-fold increase in flow circulation, indicating a direct linkage between geomorphic processes and the development of habitat complexity at both the local (1.0 m2 grid cell) and meander wavelength scale. Habitat modeling indicated that the availability of Chinook salmon spawning habitat has increased over time, whereas the majority of the reach provides low-medium quality rearing habitat for juvenile salmonids, primarily due to a lack of low velocity refuge zones. These results demonstrate the ability of geomorphic processes to increase flow complexity and enhance spawning habitat, yet there is little indication that morphological changes alone will create bioenergetically favorable conditions for juvenile salmonids in the absence of off-channel habitat and large wood. In order to better understand the relations between channel dynamics, flow complexity and individual fish performance at a given life stage, ongoing efforts are focused on using Dynamic Energy Budget theory to develop a mechanistic framework integrating information on the different salmon life stages with flow fields of varying complexity.

Harrison, L. R.; Legleiter, C. J.; Pecquerie, L.; Dunne, T.

2009-12-01

322

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

323

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

324

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...

325

Health-related quality of life and influencing factors among rural left-behind wives in Liuyang, China  

PubMed Central

Background In China, the number of left-behind wives in rural areas has reached 47 million. Left-behind wives might have more psychological stress and lower life quality. This study was to examine the health-related quality of life and influencing social and cognitive factors in a sample of left-behind wives in rural areas of China. Methods The demographic data questionnaire, the Short Form 36 Health Survey Scale, Center for Epidemiological Studies Depression Scale, Perceived Social Support Scale, Simplified Coping Style Questionnaire, and Perceived Stress Scale were completed by a sample of 1,893 left-behind wives and 969 non-left-behind wives. Results Left-behind wives had lower scores on physical component summary (PCS), mental component summary (MCS) , and all the eight subscales of the SF-36 than non-left-behind wives (P?influencing factors on the PCS of rural women, whereas the status of being left behind, monthly income, physical health status, sense of marriage security, stress, social support, passive coping styles, and depression were influencing factors on the MCS of rural women. Conclusions Left-behind wives scored lower on health-related quality of life than non-left-behind wives. Low health-related quality of life was associated with left behind status, older age, less education, low monthly income, unemployment, bad physical health status, passive coping styles, low social support, high level of stress, and high depression. PMID:24886024

2014-01-01

326

Habitat triage for exploited fishes: Can we identify essential “Essential Fish Habitat  

NASA Astrophysics Data System (ADS)

There is little doubt that estuarine habitat is important for some exploited fish species, at some times, and in some places. However, it is also clear that we do not have enough resources to conserve or restore all estuarine habitat. Consequently, a simple, quantitative and transparent approach to prioritizing estuarine habitat management is required. Here, we present a general framework for identifying critical habitats of exploited fishes. Our approach requires three basic steps: (1) develop stage-structured models and identify sensitive life history stages; (2) determine what habitats, if any, are important to these stages; and (3) identify sites in which high densities of critical life stages occur in important habitat. We will illustrate the utility of this approach using red drum, Sciaenops ocellatus. Results of a simulation-based sensitivity analysis of a stage-structured matrix model show that most of the variability in population growth rate ( ?) of red drum is explained by larval and juvenile survival rates. Thus, this approach indicates that larval/juvenile red drum habitat should be given higher priority for conservation and/or restoration than habitats used by other life history stages. To illustrate the potential importance of juvenile habitat to red drum, we modeled the growth of a hypothetical red drum population using different population matrices as manifestations of varying habitat conditions. These numerical experiments revealed that restoration of both marsh and seagrass habitats would yield a ca. 24% increase in post-settlement survival and would result in a ca. 2% increase in ?—an increase sufficient to stem a long-term population decline. Our results illustrate that protection of fish habitat depends not only on protecting sites where fish occur but also on protecting the ecological processes that allow populations to expand. Quantitative and synthetic analyses of ecological data are a first step in this direction.

Levin, Phillip S.; Stunz, Gregory W.

2005-07-01

327

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.

328

Indoor Gateball's Influence on Life Satisfaction and the Prevention of Falls by the Elderly.  

PubMed

[Purpose] The purpose of this study was to investigate the effects of indoor gateball exercise on life satisfaction and the prevention of falls by the elderly. [Subjects] Sixteen elderly subjects aged 65 or more, residents in nursing care facilities, were randomly divided into two groups. [Methods] One group performed indoor gateball exercise for 30 minutes a day, five times per week. The Tetrax fall index and life satisfaction were measured before and after four weeks of gateball exercise. [Results] The indoor gate ball exercise group showed significant improvements in the fall index and life satisfaction. [Conclusion] The indoor gateball exercise used in this study should be considered as a therapeutic method for the elderly, for improving their life satisfaction and because of its effectiveness in preventing falls. PMID:25540489

Kang, Kwon-Young

2014-12-01

329

Indoor Gateball’s Influence on Life Satisfaction and the Prevention of Falls by the Elderly  

PubMed Central

[Purpose] The purpose of this study was to investigate the effects of indoor gateball exercise on life satisfaction and the prevention of falls by the elderly. [Subjects] Sixteen elderly subjects aged 65 or more, residents in nursing care facilities, were randomly divided into two groups. [Methods] One group performed indoor gateball exercise for 30 minutes a day, five times per week. The Tetrax fall index and life satisfaction were measured before and after four weeks of gateball exercise. [Results] The indoor gate ball exercise group showed significant improvements in the fall index and life satisfaction. [Conclusion] The indoor gateball exercise used in this study should be considered as a therapeutic method for the elderly, for improving their life satisfaction and because of its effectiveness in preventing falls.

Kang, Kwon-Young

2014-01-01

330

Life-history differences among coral reef sponges promote mutualism or exploitation of mutualism by influencing partner fidelity feedback.  

PubMed

Mutualism can be favored over exploitation of mutualism when interests of potential heterospecific partners are aligned so that individual organisms are beneficial to each others' continued growth, survival, and reproduction, that is, when exploitation of a particular partner individual is costly. A coral reef sponge system is particularly amenable to field experiments probing how costs of exploitation can be influenced by life-history characteristics. Pairwise associations among three of the sponge species are mutually beneficial. A fourth species, Desmapsamma anchorata, exploits these mutualisms. Desmapsamma also differs from the other species by growing faster, fragmenting more readily, and suffering higher mortality rates. Evaluating costs and benefits of association in the context of the complex life histories of these asexually fragmenting sponges shows costs of exploitation to be high for the mutualistic species but very low for this essentially weedy species. Although it benefits from association more than the mutualist species, by relying on their superior tensile strength and extensibility to reduce damage by physical disturbance, exploitation is favored because each individual host is of only ephemeral use. These sponges illustrate how life-history differences can influence the duration of association between individuals and, thus, the role of partner fidelity in promoting mutualism. PMID:18419569

Wulff, Janie L

2008-05-01

331

Life in the Sidewalk Cracks  

NSDL National Science Digital Library

In this activity, learners compare plant and animal life in different habitats including a sidewalk crack and lawn. Learners sort human-made materials and natural materials found in each habitat. Learners also examine the specimens with a magnifying glass and make sketches. This activity can be used to explore human impact, habitats, and/or field studies.

Extension, University O.

2001-01-01

332

A general approach to the analysis of habitat selection  

Microsoft Academic Search

The investigation of animal habitat selection aims at the detection of selective usage of habitat types and the identification\\u000a of covariates influencing their selection. The results not only allow for a better understanding of the habitat selection\\u000a process but are also intended to help improve the conservation of animals. Usually, habitat selection by larger animals is\\u000a assessed by radio-tracking or

Thomas Kneib; Felix Knauer; Helmut Küchenhoff

2011-01-01

333

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

334

Influence of forage preferences and habitat use on C and N abundance in wild caribou (Rangifer tarandus caribou) and moose (Alces alces) from Canada  

Microsoft Academic Search

Stable isotope composition (?C and ?N) of moose (Alces alces) and caribou (Rangifer tarandus) hair from the boreal forest of Jacques-Cartier Park and Côte-Nord (Québec) and arctic tundra of Queen Maud Gulf and Southampton Island (Nunavut) was investigated as an indicator of dietary preferences and habitat use. Values of ?Chair and ?Nhair in moose were consistently lower compared to those

Dorothée G. Drucker; Keith A. Hobson; Jean-Pierre Ouellet; Réhaume Courtois

2010-01-01

335

The Influence of Mortality and Socioeconomic Status on Risk and Delayed Rewards: A Life History Theory Approach  

PubMed Central

Why do some people take risks and live for the present, whereas others avoid risks and save for the future? The evolutionary framework of life history theory predicts that preferences for risk and delay in gratification should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced decisions involving risk preference (e.g., $10 for sure vs. 50% chance of $20) and temporal discounting (e.g., $5 now vs. $10 later). The effect of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals who grew up relatively poor, mortality cues led them to value the present and gamble for big immediate rewards. Conversely, for individuals who grew up relatively wealthy, mortality cues led them to value the future and avoid risky gambles. Overall, mortality cues appear to propel individuals toward diverging life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors influence economic decisions and risky behaviors. PMID:21299312

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

2012-01-01

336

Life history tradeoffs influence mortality associated with the amphibian pathogen Batrachochytrium dendrobatidis  

Microsoft Academic Search

Fatal amphibian chytridiomycosis has typically been associated with the direct costs of infection. However the relationship between exposure to the pathogen, infection and mortality may not be so straightforward. Using results from both field work and experiments we report how exposure of common toads to Batrachochytrium dendrobatidis influences development and survival and how developmental stage influences host responses. Our results

Trenton W. J. Garner; Susan Walker; Jaime Bosch; Stacey Leech; J. Marcus Rowcliffe; Andrew A. Cunningham; Matthew C. Fisher

2009-01-01

337

Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie  

USGS Publications Warehouse

1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics, trophic interactions and fish community structure.

Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

2011-01-01

338

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate  

USGS Publications Warehouse

Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

Martin, Thomas E.; Ton, Riccardo; Nikilson, Alina

2013-01-01

339

Measuring marine fish biodiversity: temporal changes in abundance, life history and  

E-print Network

, the biodiversity of many coral reef and coastal marine species is also influenced by habitat loss (Friedlander). Losses of marine fish biodiversity can be reflected by various intraspecific metrics. Prominent amongMeasuring marine fish biodiversity: temporal changes in abundance, life history and demography

Baum, Julia K.

340

Distributions and habitat associations of the bridled monocle bream Scolopsis bilineatus (Nemipteridae): a demographic approach.  

PubMed

This study focussed on the demography and ecology of Scolopsis bilineatus at three locations on the Great Barrier Reef: the Lizard Island Group, Orpheus Island and One Tree Island. Scolopsis bilineatus lived for up to 16?years and had four distinct life-history stages, which varied in their distribution patterns, habitat use and reproductive behaviour. Pre-maturational sex change occurred whereby all males were derived from immature females, and males grew faster and larger than females. Small females and larger males generally formed pairs, which influenced their spatial distributions at small scales. Distributions of S. bilineatus were influenced by depth and exposure within reefs, particularly for juveniles, and most fish were found in shallow, sheltered habitats. Abundance was influenced by benthic cover, and was higher in areas of high coral cover and low where algae were abundant. Habitat associations were stronger at the microhabitat scale, and shelter sites were important for adults. Ontogenetic changes in microhabitat associations were found: juveniles occupied sand and rubble, and adults occupied shelters such as caves and overhangs. Adults showed site fidelity for shelter sites over a period of 4?days and returned to specific shelter sites repeatedly. These findings illustrate the importance of understanding the spatial ecology and habitat use of coral reef fishes, particularly with reference to size-based changes within species. PMID:23991878

Boaden, A E; Kingsford, M J

2013-09-01

341

Multi-scale Hydroacoustic Remote Sensing of Sturgeon and Their Habitats in A Large, Turbid River  

Microsoft Academic Search

Restoration and management of the Lower Missouri River (LMOR) to support recovery of the endangered pallid sturgeon (Scaphirhynchus albus) requires quantifying habitats used during all life stages in order to isolate specific habitats (if any) that present bottlenecks to reproduction and survival. All life stages of the pallid sturgeon take place in deep, turbid rivers where direct observation of habitat

R. B. Jacobson; A. Delonay; C. Vishy; C. M. Elliott; J. M. Reuter; K. A. Chojnacki

2009-01-01

342

Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary, Annual Report of Research.  

SciTech Connect

In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes in estuarine habitat opportunities and food web linkages of Columbia River salmon (Onchorhynchus spp.). Together these studies constitute the estuary's first comprehensive investigation of shallow-water habitats, including selected emergent, forested, and scrub-shrub wetlands. Among other findings, this research documented the importance of wetlands as nursery areas for juvenile salmon; quantified historical changes in the amounts and distributions of diverse habitat types in the lower estuary; documented estuarine residence times, ranging from weeks to months for many juvenile Chinook salmon (O. tshawytscha); and provided new evidence that contemporary salmonid food webs are supported disproportionately by wetland-derived prey resources. The results of these lower-estuary investigations also raised many new questions about habitat functions, historical habitat distributions, and salmon life histories in other areas of the Columbia River estuary that have not been adequately investigated. For example, quantitative estimates of historical habitat changes are available only for the lower 75 km of the estuary, although tidal influence extends 217 km upriver to Bonneville Dam. Because the otolith techniques used to reconstruct salmon life histories rely on detection of a chemical signature (strontium) for salt water, the estuarine residency information we have collected to date applies only to the lower 30 or 35 km of the estuary, where fish first encounter ocean water. We lack information about salmon habitat use, life histories, and growth within the long tidal-fresh reaches of the main-stem river and many tidally-influenced estuary tributaries. Finally, our surveys to date characterize wetland habitats within island complexes distributed in the main channel of the lower estuary. Yet some of the most significant wetland losses have occurred along the estuary's periphery, including shoreline areas and tributary junctions. These habitats may or may not function similarly as the island complexes that we have surveyed to date. In 2007 we initiated a second phase of the BPA estuary study (Phase II) to address specific uncertainties about salmon in tidal-fresh and tributary habitats of the Columbia River estuary. This report summarizes 2007 and 2008 Phase II results and addresses three principal research questions: (1) What was the historic distribution of estuarine and floodplain habitats from Astoria to Bonneville Dam? (2) Do individual patterns of estuarine residency and growth of juvenile Chinook salmon vary among wetland habitat types along the estuarine tidal gradient? (3) Are salmon rearing opportunities and life histories in the restoring wetland landscape of lower Grays River similar to those documented for island complexes of the main-stem estuary? Phase II extended our analysis of historical habitat distribution in the estuary above Rkm 75 to near Bonneville Dam. For this analysis we digitized the original nineteenth-century topographic (T-sheets) and hydrographic (H-sheets) survey maps for the entire estuary. Although all T-sheets (Rkm 0 to Rkm 206) were converted to GIS in 2005 with support for the USACE estuary project, final reconstruction of historical habitats throughout the estuary requires completion of the remaining H-sheet GIS maps above Rkm 75 and their integration with the T-sheets. This report summarizes progress to date on compiling the upper estuary H-sheets above Rkm 75. For the USACE estuary project, we analyzed otoliths from Chinook salmon collected near the estuary mouth in 2003-05 to estimate variability in estuary residence times among juvenile out migrants. In Phase II we expanded these analyses to comp

Bottom, Daniel L.; Simenstad, Charles A.; Campbell, Lance [Northwest Fisheries Science Center

2009-05-15

343

The influence of environmental conditions on early life stages of flounder (Platichthys flesus) in the central Baltic Sea  

NASA Astrophysics Data System (ADS)

Flounder (Platichthys flesus) is a temperate marine fish that is well adapted to the brackish waters of the Baltic Sea. There are two sympatric flounder populations in the Baltic Sea, pelagic and demersal spawners, which differ in their spawning habitat and egg characteristics. In the present study, pelagic spawning flounder of the central Baltic Sea was studied. We examined whether variations in hydrological regime can explain fluctuations in flounder early life stages that have occurred over the past 30 years (1970-2005). Using generalized additive modeling to explain the abundance of flounder eggs and larvae in a Latvian ichthyoplankton dataset, we evaluate the hypothesis that the available reproductive volume, defined as the water column with dissolved oxygen larger than 1 ml/l and salinity between 10.6 and 12 PSU, affects the survival of flounder ichthyoplankton and determines recruitment success. Both reproductive volume and spawning stock biomass were significant factors determining flounder ichthyoplankton abundance. Different measures of water temperature did not contribute significantly to the variability of eggs or larvae. However, recruitment did not correlate to the supply of larvae. The findings presented in this study on the relationship between flounder reproduction, spawning stock biomass and reproductive volume, as well as the lack of correlation to recruitment, are valuable for the understanding of flounder ecology in the Baltic Sea, and for developing the management of the species.

Ustups, Didzis; Müller-Karulis, Bärbel; Bergstrom, Ulf; Makarchouk, Andrej; Sics, Ivo

2013-01-01

344

The influence of interimplant distance in mandibular overdentures supported by two implants on patient satisfaction and quality of life.  

PubMed

This study evaluates the influence of interimplant distance (ID) on patient satisfaction and quality of life (QOL) of 55 patients who received mandibular overdentures supported by two implants. IDs were measured over the residual ridge crest and linearly on all of the patients' mandibular casts. The crestal detours of all patients were determined by subtracting these two values from each other. Higher IDs were associated with better QOL scores (P < .05), whereas higher crestal detour values were associated with better general comfort, chewing, ease of hygiene maintenance, esthetics, pain, and QOL scores (P < .05). PMID:25588167

Geckili, Onur; Cilingir, Altug; Erdogan, Ozge; Kesoglu, Aysun Coskun; Bilmenoglu, Caglar; Ozdiler, Arda; Bilhan, Hakan

2015-01-01

345

Does Human-Induced Habitat Modification Influence the Impact of Introduced Species? A Case Study on Cavity-Nesting by the Introduced Common Myna ( Acridotheres tristis) and Two Australian Native Parrots  

NASA Astrophysics Data System (ADS)

Introduced species pose a major threat to biodiversity across the globe. Understanding the impact of introduced species is critical for effective management. Many species around the world are reliant on tree cavities, and competition for these resources can be intense: threatening the survival of native species. Through the establishment of 225 nest boxes, we examined the relationship between tree density and the abundance and nesting success of three bird species in Canberra, Australia. The common myna ( Acridotheres tristis) is an introduced species in Australia, and the crimson rosella ( Platycercus elegans) and eastern rosella ( Platycercus eximius) are native species. We then investigated the impact of common myna nest box occupation on crimson rosella and eastern rosella abundance. Tree density significantly influenced the abundance and cavity-nesting of all three species. Common myna abundance (birds per square kilometer) was greatest at low tree density sites (101.9 ± 22.4) and declined at medium (45.4 ± 10.1) and high (9.7 ± 3.6) tree density sites. The opposite pattern was observed for the crimson rosella, with greater abundance (birds per square kilometer) at high tree density sites (83.9 ± 9.3), declining over medium (61.6 ± 6.4) and low (31.4 ± 3.9) tree density sites. The eastern rosella was more abundant at medium tree density sites (48.6 ± 8.0 birds per square kilometer). Despite the strong influence of tree density, we found a significant negative relationship between common myna nest box occupancy and the abundance of the crimson rosella ( F 1,13 = 7.548, P = 0.017) and eastern rosella ( F 1,13 = 9.672, P < 0.001) at some sites. We also observed a slight increase in rosella nesting interruptions by the common myna at lower tree densities (high: 1.3 % ± 1.3, medium: 6.6 % ± 2.2, low: 12.7 % ± 6.2), although this increase was not statistically significant ( F 2,40 = 2.435, P = 0.100). Our study provides the strongest evidence to date for the negative impact of the common myna on native bird abundance through cavity-nesting competition. However, due to the strong influence of habitat on species abundance and nesting, it is essential to investigate the impacts of introduced species in conjunction with habitat variation. We also suggest one component of introduced species management could include habitat restoration to reduce habitat suitability for introduced species.

Grarock, Kate; Lindenmayer, David B.; Wood, Jeffrey T.; Tidemann, Christopher R.

2013-10-01

346

Does human-induced habitat modification influence the impact of introduced species? A case study on cavity-nesting by the introduced common myna (Acridotheres tristis) and two Australian native parrots.  

PubMed

Introduced species pose a major threat to biodiversity across the globe. Understanding the impact of introduced species is critical for effective management. Many species around the world are reliant on tree cavities, and competition for these resources can be intense: threatening the survival of native species. Through the establishment of 225 nest boxes, we examined the relationship between tree density and the abundance and nesting success of three bird species in Canberra, Australia. The common myna (Acridotheres tristis) is an introduced species in Australia, and the crimson rosella (Platycercus elegans) and eastern rosella (Platycercus eximius) are native species. We then investigated the impact of common myna nest box occupation on crimson rosella and eastern rosella abundance. Tree density significantly influenced the abundance and cavity-nesting of all three species. Common myna abundance (birds per square kilometer) was greatest at low tree density sites (101.9 ± 22.4) and declined at medium (45.4 ± 10.1) and high (9.7 ± 3.6) tree density sites. The opposite pattern was observed for the crimson rosella, with greater abundance (birds per square kilometer) at high tree density sites (83.9 ± 9.3), declining over medium (61.6 ± 6.4) and low (31.4 ± 3.9) tree density sites. The eastern rosella was more abundant at medium tree density sites (48.6 ± 8.0 birds per square kilometer). Despite the strong influence of tree density, we found a significant negative relationship between common myna nest box occupancy and the abundance of the crimson rosella (F 1,13 = 7.548, P = 0.017) and eastern rosella (F 1,13 = 9.672, P < 0.001) at some sites. We also observed a slight increase in rosella nesting interruptions by the common myna at lower tree densities (high: 1.3% ± 1.3, medium: 6.6% ± 2.2, low: 12.7% ± 6.2), although this increase was not statistically significant (F 2,40 = 2.435, P = 0.100). Our study provides the strongest evidence to date for the negative impact of the common myna on native bird abundance through cavity-nesting competition. However, due to the strong influence of habitat on species abundance and nesting, it is essential to investigate the impacts of introduced species in conjunction with habitat variation. We also suggest one component of introduced species management could include habitat restoration to reduce habitat suitability for introduced species. PMID:23716011

Grarock, Kate; Lindenmayer, David B; Wood, Jeffrey T; Tidemann, Christopher R

2013-10-01

347

The effects of chemical interactions and culture history on the colonization of structured habitats by competing bacterial populations  

PubMed Central

Background Bacterial habitats, such as soil and the gut, are structured at the micrometer scale. Important aspects of microbial life in such spatial ecosystems are migration and colonization. Here we explore the colonization of a structured ecosystem by two neutrally labeled strains of Escherichia coli. Using time-lapse microscopy we studied the colonization of one-dimensional arrays of habitat patches linked by connectors, which were invaded by the two E. coli strains from opposite sides. Results The two strains colonize a habitat from opposite sides by a series of traveling waves followed by an expansion front. When population waves collide, they branch into a continuing traveling wave, a reflected wave and a stationary population. When the two strains invade the landscape from opposite sides, they remain segregated in space and often one population will displace the other from most of the habitat. However, when the strains are co-cultured before entering the habitats, they colonize the habitat together and do not separate spatially. Using physically separated, but diffusionally coupled, habitats we show that colonization waves and expansion fronts interact trough diffusible molecules, and not by direct competition for space. Furthermore, we found that colonization outcome is influenced by a culture’s history, as the culture with the longest doubling time in bulk conditions tends to take over the largest fraction of the habitat. Finally, we observed that population distributions in parallel habitats located on the same device and inoculated with cells from the same overnight culture are significantly more similar to each other than to patterns in identical habitats located on different devices inoculated with cells from different overnight cultures, even tough all cultures were started from the same ?80°C frozen stock. Conclusions We found that the colonization of spatially structure habitats by two interacting populations can lead to the formation of complex, but reproducible, spatiotemporal patterns. Furthermore, we showed that chemical interactions between two populations cause them to remain spatially segregated while they compete for habitat space. Finally, we observed that growth properties in bulk conditions correlate with the outcome of habitat colonization. Together, our data show the crucial roles of chemical interactions between populations and a culture’s history in determining the outcome of habitat colonization. PMID:24884963

2014-01-01

348

Campus Habitat Improvement Plan  

NSDL National Science Digital Library

In working with students to provide suitable habitat for species of interest, teachers can begin to develop the school campus into an outdoor classroom. Students will build self-esteem while obtaining useful real-life skills related to ecological practices. Students will have the opportunity to work with professionals from related fields of study. The hands-on activities give students a chance to put into practice the theories and themes that have been studied in a closed classroom setting. Students will learn to read aerial photographs, perform biological surveys, and write wildlife management plans. They will carry out management practices on the campus site and learn to evaluate the success of their program.

BEGIN:VCARD VERSION:2.1 FN:Francis Carter N:Carter;Francis ORG:Somerset High School REV:2005-04-15 END:VCARD

1995-06-30

349

The Influence of Subjective Life Expectancy on Retirement Transition and Planning: A Longitudinal Study  

ERIC Educational Resources Information Center

This study examines the construct of subjective life expectancy (SLE), or the estimation of one's probable age of death. Drawing on the tenets of socioemotional selectivity theory (Carstensen, Isaacowitz, & Charles, 1999), we propose that SLE provides individuals with their own unique mental model of remaining time that is likely to affect their…

Griffin, Barbara; Hesketh, Beryl; Loh, Vanessa

2012-01-01

350

How does seed heteromorphism influence the life history stages of Atriplex sagittata (Chenopodiaceae)?  

Microsoft Academic Search

Atriplex sagittata is an annual, heterocarpic species producing three types of fruits, (i) dormant ebracteate (further termed type A), (ii) dormant bracteate (type B) and (iii) non-dormant bracteate (type C). In this study, we investigated populations grown from particular fruit types under different density regimes, and assessed their fate in particular life stages throughout a complete growing season. Differences in

Bohumil Mandaka; Petr Pys

351

Factors Influencing Midlife and Older Adults' Attendance in Family Life Education Programs  

ERIC Educational Resources Information Center

This study explored the likelihood of midlife and older adults attending a family life education program by assessing learner characteristics and deterrents to and motivators of attendance. Data were collected through a survey mailed to a stratified sample of adults aged 50 and over. Discriminant analysis results based on survey responses from 264…

Ballard, Sharon M.; Morris, Michael Lane

2005-01-01

352

Influence of Support Media Characteristics on Biofilm Activity in Graywater Treatment Systems for Advanced Life Support  

Microsoft Academic Search

Advanced life support systems for long-duration space missions will require efficient recycling of water and air. Biological treatment systems may be used as the initial process in a multistep recycling system. Biofilm reactors (or biotrickling filters) have been shown to be effective for treatment of air and water. A major design consideration for these reactors is the selection of biofilm

Neepa Shah; Sybill E. Sharvelle; M. Katherine Banks

2007-01-01

353

Influences of Marriage, Motherhood, and Other Life Events on Australian Women's Employment Aspirations  

ERIC Educational Resources Information Center

The study contributes to the understandings of how women negotiate work and family over the life course by investigating what factors impact young women's aspirations for full time, part-time, and other forms of work. Using data from the Australian Longitudinal Study on Women's Health (ALSWH) with its nationally representative sample of Australian…

Johnstone, Melissa; Lucke, Jayne; Lee, Christina

2011-01-01

354

System Integration and Its Influence on the Quality of Life of Children with Complex Needs  

PubMed Central

Purpose. To explore the interactions between child and parents psychosocial factors and team integration variables that may explain improvements in physical dimensions of the PEDS QL quality of life of children with complex needs after 2 years. Methods. In this 2-year study, parents were identified by the Children's Treatment Network. Families were eligible if the child was aged 0–19 years, had physical limitations, resided in either Simcoe County or the Region of York, Ontario, and there were multiple other family needs. Regression analysis used to explore associations and interactions; n = 110. Results. A child's physical quality of life was affected by interacting factors including child's behavior, parenting, and integrated care. Statistically significant interactions between team integration, processes of care, and child/parent variables highlight the complexity of the rehabilitation approach in real-life situations. Conclusions. Rehabilitation providers working with children with complex needs and their families should also address child and parent problematic behaviors. When this was the case in high integrated teams, the child's physical quality of life improved after two years. PMID:20976132

Thurston, Sandy; Paul, Louise; Ye, Chenglin; Loney, Patricia; Browne, Dillon; Browne, Gina; Wong, Maria; Thabane, Lehana; Rosenbaum, Peter

2010-01-01

355

Emotional expressiveness during worship services and life satisfaction: assessing the influence of race and religious affiliation  

Microsoft Academic Search

The purpose of this study is to see if an emotional expressive worship style is associated with life satisfaction. Our study model contains the following core relationships: (1) blacks are more likely than whites to worship in conservative Protestant congregations; (2) members of conservative congregations and blacks will attend church services more often; (3) blacks and conservative Protestants are more

Neal Krause; R. David Hayward

2012-01-01

356

Influence of light exposure on characteristics and storage life of kiwifruit  

Microsoft Academic Search

Quality and storage life of kiwifruit were investigated on fruits from shaded and exposed positions of the canopy and on fruits artificially shaded and grown in absence of light. At harvest the fruits grown in high light intensity have a high quality and can be stored for a long time; after 25 weeks of cool storage they have a soluble

A. Tombesi; E. Antognozzi; A. Palliotti

1993-01-01

357

Habitat of early life: Solar X-ray and UV radiation at Earth's surface 4-3.5 billion years ago  

E-print Network

Solar X-ray and UV radiation (0.1-320 nm) received at Earth's surface is an important aspect of the circumstances under which life formed on Earth. The quantity that is received depends on two main variables: the emission of radiation by the young Sun and its extinction through absorption and scattering by the Earth's early atmosphere. The spectrum emitted by the Sun when life formed, between 4 and 3.5 Ga, was modeled here, including the effects of flares and activity cycles, using a solar-like star that has the same age now as the Sun had 4-3.5 Ga. Atmospheric extinction was calculated using the Beer-Lambert law, assuming several density profiles for the atmosphere of the Archean Earth. We found that almost all radiation with a wavelength shorter than 200 nm is attenuated effectively, even by very tenuous atmospheres. Longer-wavelength radiation is progressively less well attenuated, and its extinction is more sensitive to atmospheric composition. Minor atmospheric components, such as methane, ozone, water vapor, etc., have only negligible effects, but changes in CO2 concentration can cause large differences in surface flux. Differences due to variability in solar emission are small compared to this. In all cases surface radiation levels on the Archean Earth were several orders of magnitude higher in the 200-300 nm wavelength range than current levels in this range. That means that any form of life that might have been present at Earth's surface 4-3.5 Ga must have been exposed to much higher quantities of damaging radiation than at present.

I. Cnossen; J. Sanz-Forcada; F. Favata; O. Witasse; T. Zegers; N. F. Arnold

2007-02-20

358

Habitat requirements of Atlantic salmon and brown trout in rivers and streams  

Microsoft Academic Search

The distributions and abundances of trout and salmon are strongly influenced by their habitat. The habitat includes both abiotic and biotic factors, which interact in complex webs. Habitat probably has strongest effects during population bottlenecks, when the standing stock approaches the carrying capacity of the environment. Various approaches to modelling interactions between habitat and population density and mean weight have

J. D Armstrong; P. S Kemp; G. J. A Kennedy; M Ladle; N. J Milner

2003-01-01

359

Habitat of early life: Solar X-ray and UV radiation at Earth's surface 4-3.5 billion years ago  

E-print Network

Solar X-ray and UV radiation (0.1-320 nm) received at Earth's surface is an important aspect of the circumstances under which life formed on Earth. The quantity that is received depends on two main variables: the emission of radiation by the young Sun and its extinction through absorption and scattering by the Earth's early atmosphere. The spectrum emitted by the Sun when life formed, between 4 and 3.5 Ga, was modeled here, including the effects of flares and activity cycles, using a solar-like star that has the same age now as the Sun had 4-3.5 Ga. Atmospheric extinction was calculated using the Beer-Lambert law, assuming several density profiles for the atmosphere of the Archean Earth. We found that almost all radiation with a wavelength shorter than 200 nm is attenuated effectively, even by very tenuous atmospheres. Longer-wavelength radiation is progressively less well attenuated, and its extinction is more sensitive to atmospheric composition. Minor atmospheric components, such as methane, ozone, water v...

Cnossen, I; Favata, F; Witasse, O; Zegers, T; Arnold, N F

2007-01-01

360

Relating Habitat and Climatic Niches in Birds  

E-print Network

Predicting species ’ responses to the combined effects of habitat and climate changes has become a major challenge in ecology and conservation biology. However, the effects of climatic and habitat gradients on species distributions have generally been considered separately. Here, we explore the relationships between the habitat and thermal dimensions of the ecological niche in European common birds. Using data from the French Breeding Bird Survey, a large-scale bird monitoring program, we correlated the habitat and thermal positions and breadths of 74 bird species, controlling for life history traits and phylogeny. We found that cold climate species tend to have niche positions in closed habitats, as expected by the conjunction of the biogeographic history of birds ’ habitats, and their current continent-scale gradients. We also report a positive correlation between thermal and habitat niche breadths, a pattern consistent with macroecological predictions concerning the processes shaping species ’ distributions. Our results suggest that the relationships between the climatic and habitat components of the niche have to be taken into account to understand and predict changes in species’

Jean-yves Barnagaud; Vincent Devictor; Frédéric Jiguet; Morgane Barbet-massin; Isabelle Le Viol; Frédéric Archaux

2011-01-01

361

Evidence that life history characteristics of wild birds influence infection rates and exposure to influenza A viruses  

USGS Publications Warehouse

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 (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.

Ely, Craig R.; Hall, Jeffrey S.; Schmutz, Joel A.; Pearce, John M.; Terenzi, John; Sedinger, James S.; Ip, Hon S.

2013-01-01

362

Can settlement in natal-like habitat explain maladaptive habitat selection?  

PubMed Central

The study of habitat selection has long been influenced by the ideal free model, which maintains that young adults settle in habitat according to its inherent quality and the density of conspecifics within it. The model has gained support in recent years from the finding that conspecifics produce cues inadvertently that help prebreeders locate good habitat. Yet abundant evidence shows that animals often fail to occupy habitats that ecologists have identified as those of highest quality, leading to the conclusion that young animals settle on breeding spaces by means not widely understood. Here, we report that a phenomenon virtually unknown in nature, natal habitat preference induction (NHPI), is a strong predictor of territory settlement in both male and female common loons (Gavia immer). NHPI causes young animals to settle on natal-like breeding spaces, but not necessarily those that maximize reproductive success. If widespread, NHPI might explain apparently maladaptive habitat settlement. PMID:23804619

Piper, Walter H.; Palmer, Michael W.; Banfield, Nathan; Meyer, Michael W.

2013-01-01

363

Nutritional physiology of life-history trade-offs: how food protein-carbohydrate content influences life-history traits in the wing-polymorphic cricket Gryllus firmus.  

PubMed

Although life-history trade-offs result from the differential acquisition and allocation of nutritional resources to competing physiological functions, many aspects of this topic remain poorly understood. Wing-polymorphic insects, which possess alternative morphs that trade off allocation to flight capability versus early reproduction, provide a good model system for exploring this topic. In this study, we used the wing-polymorphic cricket Gryllus firmus to test how expression of the flight capability versus reproduction trade-off was modified across a heterogeneous protein-carbohydrate nutritional landscape. Newly molted adult female long- and short-winged crickets were given one of 13 diets with different concentrations and ratios of protein and digestible carbohydrate; for each cricket, we measured consumption patterns, growth and allocation to reproduction (ovary mass) versus flight muscle maintenance (flight muscle mass and somatic lipid stores). Feeding responses in both morphs were influenced more by total macronutrient concentration than by protein-carbohydrate ratio, except at high-macronutrient concentration, where protein-carbohydrate balance was important. Mass gain tended to be greatest on protein-biased diets for both morphs, but was consistently lower across all diets for long-winged females. When long-winged females were fed high-carbohydrate foods, they accumulated greater somatic lipid stores; on high-protein foods, they accumulated greater somatic protein stores. Food protein-carbohydrate content also affected short-winged females (selected for early reproductive onset), which showed dramatic increases in ovary size, including ovarian stores of lipid and protein, on protein-biased foods. This is the first study to show how the concentration and ratio of dietary protein and carbohydrate affects consumption and allocation to key physiological features associated with the reproduction-dispersal life-history trade-off. PMID:25524979

Clark, Rebecca M; Zera, Anthony J; Behmer, Spencer T

2015-01-15

364

Food availability and nest predation influence life history traits in Audouin's gull, Larus audouinii  

Microsoft Academic Search

The effects of food availability and nest predation on several life history traits such as adult survival, dispersal, and\\u000a reproductive performance were assessed in an Audouin's gull (Larus audouinii) colony during the period 1992–1997. The amounts of fish discarded from trawlers were used as a measure of food availability,\\u000a and a trawling moratorium which partially overlapped with the breeding season

Daniel Oro; Roger Pradel; Jean-Dominique Lebreton

1999-01-01

365

Submandibular salivary glands: influence on growth rate and life span in mice  

Microsoft Academic Search

Submandibular glands accumulate a variety of growth factors, especially in male mice. Surgical excision of these glands (sialoadenectomy)\\u000a results in alterations in several organs and systems including the liver, skin and reproductive system. We studied the life-long\\u000a consequences of sialoadenectomy in male mice. Animals were operated at the age of 10 weeks. Thereafter, body weight and food\\u000a and water intake were

Ignasi Ramírez; Maria Soley

2011-01-01

366

Influence of age on Medicare expenditures and medical care in the last year of life  

Microsoft Academic Search

CONTEXT: Expenditures for Medicare beneficiaries in the last year of life decrease with increasing age. The cause of this phenomenon is uncertain.\\u000aOBJECTIVES: To examine this pattern in detail and evaluate whether decreases in aggressiveness of medical care explain the phenomenon.\\u000aDESIGN, SETTING, AND PATIENTS: Analysis of sample Medicare data for beneficiaries aged 65 years or older from Massachusetts (n

Norman G. Levinsky; Wei Yu; Arlene S. Ash; Mark A. Moskowitz; Gail Gazelle; Oolga Saynina; Ezekiel J. Emanuel

2001-01-01

367

Influence of Host Origin on Host Choice of the Parasitoid Dinarmus basalis: Does Upbringing Influence Choices Later in Life?  

PubMed Central

The aim of this study was to investigate the influence of volatile compounds from four secondary host plants on the ability of Dinarmus basalis Rond. (Hymenoptera: Pteromalidae) to locate, recognize, and parasitize its host, 4th instar larvae or pupae of Callosobruchus maculatus F. (Coleoptera: Chrysomelidae). To examine this, strains of D. basalis were transferred from cowpea seeds (Vigna unguiculata (L.) Walp. (Fabales: Fabaceae)) to pigeon pea (Cajanus cajan (L.) Millsp.) and two varieties of Bambara groundnut (Vigna subterranea (L.) Verdc.) seeds. The ability of D. basalis females to recognize the volatile compounds emanating from their complex host plant was tested by using a Y-tube olfactometer and a three-dimensional device. The results suggest that when females have a choice between pure air and the air emanating from their complex host of origin, they are attracted to the air tainted by the volatile compounds they have become accustomed to. They spent significantly more time (p < 0.0001) in the branch of the tube leading to the odorous air than in the tube leading to the pure air. When females from pigeon pea seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4th instar larvae, the familiar odor of pigeon pea seeds were most attractive. When females from Bambara groundnut (white and striped) seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4th instar larvae, they were significantly attracted to the odour of cowpea seeds. In the three-dimensional system, the females from the four strains did not appear to have any preference for a given type of seed containing 4th instar larvae or pupae. The parasitism rate remained high on all four types of seeds used. These results show that the use of D. basalis as a biological control agent is possible in host changing situations where C. maculatus starts to attack other legumes. The results of this study also provide information supporting the behavioral plasticity of D. basalis. Understanding the mechanisms involved in the adaptive phenomena of biological control agents is discussed in the context of the development of adequate methods of pest control. PMID:25373173

Sankara, F.; Dabiré, L. C. B.; Ilboudo, Z.; Dugravot, S.; Cortesero, A. M.; Sanon, A.

2014-01-01

368

Current Life Concerns of Early Adolescents and Their Mothers: Influence of Maternal HIV.  

ERIC Educational Resources Information Center

This study examined influences of maternal HIV on concerns among inner-city minority families. Findings indicated that beyond concerns reported by early adolescent children of HIV-negative mothers, concerns of children of HIV-positive mothers included mothers' sickness and death, adult responsibilities, and uncertainty about their futures.…

Brackis-Cott, Elizabeth; Mellins, Claude Ann; Block, Megan

2003-01-01

369

Neighborhood and School Influences on the Family Life and Mathematics Performance of Eighth-Grade Students.  

ERIC Educational Resources Information Center

This study examines how neighborhoods, schools, and families can influence the mathematics achievement of eighth graders, using data from the 1988 National Educational Longitudinal Study combined with U.S. Census data. These data allow simultaneous analysis of all aspects of students' lives. Results indicate that there are associations between…

Catsambis, Sophia; Beveridge, Andrew A.

370

Influence of basin-scale physical variables on life history characteristics of cutthroat trout in Yellowstone Lake  

USGS Publications Warehouse

Individual spawning populations of Yellowstone cutthroat trout Oncorhynchus clarki bouvieri differ in life history characteristics associated with broad spatial and temporal environmental patterns, but relationships between specific life history characteristics of Yellowstone cutthroat trout and physical aspects of the environment are poorly understood. We examined basin-scale physical characteristics of tributary drainages and subbasins of Yellowstone Lake in relation to timing (peak and duration) of lacustrinea??adfluvial Yellowstone cutthroat trout spawning migrations and mean length of cutthroat trout spawners in 27 tributaries to the lake. Stream drainages varied along gradients that can be described by mean aspect, mean elevation, and drainage and stream size. Approximately two-thirds of the variation in the timing of the peak of the annual cutthroat trout spawning migrations and average length of spawners was explained by third-order polynomial regressions with mean aspect and basin area as predictor variables. Because most cutthroat trout ascend tributaries soon after peak runoff, it appears that the influence of basin-scale physical variables on the date of the migration peak is manifested by the pattern of stream discharge. Spawner length does not seem to be a direct function of stream size in the Yellowstone Lake watershed, and aspect of the tributary basin seems to have a greater influence on the body length of cutthroat trout spawners than does stream size. Mechanisms that explain how the interaction of basin-scale physical variables influence spawner length were not investigated directly; however, we found evidence of distinct aggregations of cutthroat trout that are related to physical and limnological characteristics of the lake subbasins, and there is some indication that lake residence may be related to tributary location.

Gresswell, Robert E.; Liss, W.J.; Larson, Gary L.; Bartlein, P.J.

1997-01-01

371

Life course influences of physical and cognitive function and personality on attitudes to aging in the Lothian Birth Cohort 1936.  

PubMed

ABSTRACT Background: Reports of attitudes to aging from older people themselves are scarce. Which life course factors predict differences in these attitudes is unknown. Methods: We investigated life course influences on attitudes to aging in healthy, community-dwelling people in the UK. Participants in the Lothian Birth Cohort 1936 completed a self-report questionnaire (Attitudes to Aging Questionnaire, AAQ) at around age 75 (n = 792, 51.4% male). Demographic, social, physical, cognitive, and personality/mood predictors were assessed, around age 70. Cognitive ability data were available at age 11. Results: Generally positive attitudes were reported in all three domains: low Psychosocial Loss, high Physical Change, and high Psychological Growth. Hierarchical multiple regression found that demographic, cognitive, and physical variables each explained a relatively small proportion of the variance in attitudes to aging, with the addition of personality/mood variables contributing most significantly. Predictors of attitudes to Psychosocial Loss were high neuroticism; low extraversion, openness, agreeableness, and conscientiousness; high anxiety and depression; and more physical disability. Predictors of attitudes to Physical Change were: high extraversion, openness, agreeableness, and conscientiousness; female sex; social class; and less physical disability. Personality predictors of attitudes to Psychological Growth were similar. In contrast, less affluent environment, living alone, lower vocabulary scores, and slower walking speed predicted more positive attitudes in this domain. Conclusions: Older people's attitudes to aging are generally positive. The main predictors of attitude are personality traits. Influencing social circumstances, physical well-being, or mood may result in more positive attitudes. Alternatively, interventions to influence attitudes may have a positive impact on associated physical and affective changes. PMID:24622392

Shenkin, Susan D; Laidlaw, Ken; Allerhand, Mike; Mead, Gillian E; Starr, John M; Deary, Ian J

2014-03-13

372

Influence of aerosols on the life cycle of a radiation fog event. A numerical and observational study  

NASA Astrophysics Data System (ADS)

Despite the knowledge gained on the physical processes dominating the formation, development and dissipation of radiation fog events, uncertainties still exist about the role of the microphysical processes related to aerosol characteristics. The objective of this work is to analyze the sensitivity of fog to aerosols through their impacts on the fog droplets. A radiation fog event that formed on 15/11/2011 at the SIRTA Observatory near Paris in the context of the 2011-2012 ParisFog field campaign is the basis of this study. The selected case is one that initially forms a few hundred meters above the surface and within half an hour lowers down to the surface. A combination of SIRTA's sophisticated observations and 1D numerical simulations is employed with the aim of better understanding the influence of thermodynamics and microphysics on the life-cycle of the fog event and the degree to which aerosol characteristics such as concentration of potentially activated aerosols, size and solubility affect its characteristics. It results that the model simulates fairly well the fog life cycle, with only one half hour advance in the onset and one hour in the dissipation at the surface. The quality of the reference simulation is evaluated against several in-situ and remote sensing measurements. A numerical sensitivity analysis shows that the fog characteristics are strongly influenced by the aerosols. Doubling (halving) the cloud condensation nuclei (CCN) number translates into a 160% increase (65% decrease) in the production of fog droplets, and a 60% increase (40% decrease) of the liquid water path (LWP). The aerosols influence up to 10% the fog geometrical thickness. The necessity for more detailed local forcings that will produce better thermohygrometric conditions in the upper levels above the formed fog layer is underlined, as well as the addition of microphysical measurements in the vertical that will allow to improve two-moment microphysics schemes.

Stolaki, S.; Haeffelin, M.; Lac, C.; Dupont, J.-C.; Elias, T.; Masson, V.

2015-01-01

373

Influences of the Landscape on Life Cycle Carbon Intensity of Biofuels  

NASA Astrophysics Data System (ADS)

Biofuels derived from first (sugar and starch based) and second (lignocellulosic) generation agricultural feedstocks will continue to expand into the market between now and 2022 as incentivized through the federal Energy Independence and Security Act (EISA). Nitrogen use is one of the key environmental concerns within the life cycle since it is both the dominant source of life cycle greenhouse gas (GHG) emissions (energy from N fertilizer production and N2O emissions) and poses risks of reactive N movement throughout agricultural landscapes and watersheds. The other dominant components of the feedstock production on life cycle GHG emissions are tillage and land use change impacts on soil organic carbon (SOC). Opportunities to reduce reactive N through winter double crops may satisfy the dual goal of mitigating N2O emissions and reducing NO3 loses while meeting the objectives of EISA. However, changes in N2O, NO3, and SOC are variable within the agricultural landscape due to soil texture, climate, and crop rotation history thereby increasing the complexity of developing mitigation recommendations. Moreover, the inherent variability in N2O emissions makes it difficult to develop single life cycle carbon intensity profiles for specific fuel pathways that apply across the US, since those pathways will have geographic dependencies. Estimating the expected changes in N2O and SOC is an integral part of quantifying the life cycle GHG profile of biofuels derived from winter double crop feedstocks, while NO3 losses affect both indirect N2O emissions and water quality. The biogeochemical model DayCent was used to simulate the impact of growing winter barley as a double crop following corn before soybean establishment during the winter fallow period for six states in the Mid Atlantic region of the Eastern US on SOC and direct and indirect N2O. EPA is currently reviewing the addition of an advanced fuel pathway for winter barley in the Mid Atlantic region as part of the RFS2 program. Modeling results showed that N2O emissions varied across the landscape; NO3 leaching was higher on the sandy coastal plains soils leading to higher indirect N2O emissions, but direct N2O emissions were higher on the finer textured clay soils. In spite of the variabilities present due to landscape characteristics noted above, when DayCent estimates of changes in N2O emissions and SOC from addition of winter barley into the corn soybean rotation in the Mid Atlantic region were coupled with life cycle inventory results developed for winter barley-to-ethanol fuel expected to be produced from this region, results indicate that the fuel could meet advanced fuel status under EISA because the life cycle carbon intensity of the biofuel is at least 50% lower than a baseline gasoline fuel. This case study demonstrates a possible benefit of one approach to nitrogen management that also meets an important market opportunity mandated by law.

Adler, P. R.; Del Grosso, S.; Parton, W. J.; Spatari, S.

2011-12-01

374

Comparing adult hippocampal neurogenesis in mammalian species and orders: influence of chronological age and life history stage.  

PubMed

Adult hippocampal neurogenesis is a prominent event in rodents. In species with longer life expectancies, newly born cells in the adult dentate gyrus of the hippocampal formation are less abundant or can be completely absent. Several lines of evidence indicate that the regulatory mechanisms of adult neurogenesis differ between short- and long-lived mammals. After a critical appraisal of the factors and problems associated with comparing different species, we provide a quantitative comparison derived from seven laboratory strains of mice (BALB, C57BL/6, CD1, outbred) and rats (F344, Sprague-Dawley, Wistar), six other rodent species of which four are wild-derived (wood mouse, vole, spiny mouse and guinea pig), three non-human primate species (marmoset and two macaque species) and one carnivore (red fox). Normalizing the number of proliferating cells to total granule cell number, we observe an overall exponential decline in proliferation that is chronologically equal between species and orders and independent of early developmental processes and life span. Long- and short-lived mammals differ with regard to major life history stages; at the time points of weaning, age at first reproduction and average life expectancy, long-lived primates and foxes have significantly fewer proliferating cells than rodents. Although the database for neuronal differentiation is limited, we find indications that the extent of neuronal differentiation is subject to species-specific selective adaptations. We conclude that absolute age is the critical factor regulating cell genesis in the adult hippocampus of mammals. Ontogenetic and ecological factors primarily influence the regulation of neuronal differentiation rather than the rate of cell proliferation. PMID:21929629

Amrein, Irmgard; Isler, Karin; Lipp, Hans-Peter

2011-09-01

375

Inbreeding depression in an insect with maternal care: influences of family interactions, life stage and offspring sex.  

PubMed

Although inbreeding is commonly known to depress individual fitness, the severity of inbreeding depression varies considerably across species. Among the factors contributing to this variation, family interactions, life stage and sex of offspring have been proposed, but their joint influence on inbreeding depression remains poorly understood. Here, we demonstrate that these three factors jointly shape inbreeding depression in the European earwig, Forficula auricularia. Using a series of cross-breeding, split-clutch and brood size manipulation experiments conducted over two generations, we first showed that sib mating (leading to inbred offspring) did not influence the reproductive success of earwig parents. Second, the presence of tending mothers and the strength of sibling competition (i.e. brood size) did not influence the expression of inbreeding depression in the inbred offspring. By contrast, our results revealed that inbreeding dramatically depressed the reproductive success of inbred adult male offspring, but only had little effect on the reproductive success of inbred adult female offspring. Overall, this study demonstrates limited effects of family interactions on inbreeding depression in this species and emphasizes the importance of disentangling effects of sib mating early and late during development to better understand the evolution of mating systems and population dynamics. PMID:23981229

Meunier, J; Kölliker, M

2013-10-01

376

Enchanted Learning: Biomes-Habitats  

NSDL National Science Digital Library

Created by Enchanted Learning, this kid-friendly Biome-Habitats website introduces children to many of the earth's biomes. Although the site provides basic information about many different biomes, the main emphasis is on the animals that live in each habitat. From the homepage, site visitors can link to almost twenty separate biome / habitat sites including Desert, Cave, Savanna, and Coral Reef-just too name a few. Each site presents a brief introduction covering general characteristics, such as plant life and climate, and then provides links to many separate animal pages ranging from grasshoppers to eagles. The animal pages feature nice diagrams (that can be printed out for coloring) and basic information about anatomy, diet and more. The Biome-Habitats homepage also contains a simple chart listing differences between biomes including elements such as amount of water, temperature range, and soil quality. (Note: While the site asks for a $20 / year donation, it is free to use and requires no registration or fee).

377

Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.  

PubMed

In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080

Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B

2014-01-01

378

Influence of tinnitus on pain severity and quality of life in patients with temporomandibular disorders  

PubMed Central

Objective The aim of this cross-sectional study was to evaluate the relationship among pain intensity and duration, presence of tinnitus and quality of life in patients with chronic temporomandibular disorders (TMD). Material and Methods Fifty-nine female patients presenting with chronic TMD were selected from those seeking for treatment at the Bauru School of Dentistry Orofacial Pain Center. Patients were submitted to the Research Diagnostic Criteria anamnesis and physical examination. Visual analog scale was used to evaluate the pain intensity while pain duration was assessed by interview. Oral Health Impact Profile inventory modified for patients with orofacial pain was used to evaluate the patients' quality of life. The presence of tinnitus was assessed by self report. The patients were divided into: with or without self report of tinnitus. The data were analyzed statistically using the Student's t-test and Pearson's Chi-square test, with a level of significance of 5%. Results The mean age for the sample was 35.25 years, without statistically significant difference between groups. Thirty-two patients (54.24%) reported the presence of tinnitus. The mean pain intensity by visual analog scale was 77.10 and 73.74 for the groups with and without tinnitus, respectively. The mean pain duration was 76.12 months and 65.11 months for the groups with and without tinnitus, respectively. The mean OHIP score was 11.72 and 11.74 for the groups with and without tinnitus, respectively. There was no statistically significant difference between groups for pain intensity, pain duration and OHIP scoreS (p>0.05). Conclusion Chronic TMD pain seems to play a more significant role in patient's quality of life than the presence of tinnitus. PMID:22666832

CALDERON, Patrícia dos Santos; HILGENBERG, Priscila Brenner; ROSSETTI, Leylha Maria Nunes; LAURENTI, João Vítor El Hetti; CONTI, Paulo César Rodrigues

2012-01-01

379

Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds  

PubMed Central

In general, tropical birds have a “slow pace of life,” lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal’s life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080

Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.

2014-01-01

380

Geomorphological, trophic and human influences on the bamboo coral Isidella elongata assemblages in the deep Mediterranean: To what extent does Isidella form habitat for fish and invertebrates?  

NASA Astrophysics Data System (ADS)

We analyzed what are the best ecological conditions for megafauna associated with the bamboo coral Isidella elongata based on the geomorphological, physical and trophic information taken in 3 stations (St1, St2, St3) off the southern Catalonian coasts at 620 m depth in June 2011. Results were compared with assemblage compositions recorded in past cruises (May 1992, 1994) at the same 3 stations. St1 was in a fishing ground exploited since the 1940s over a relatively wide slope at ca. 22 km from the nearest canyon head; St2 and St3 were on a narrower slope closer to canyon heads and to the Ebro river mouth than St1. I. elongata had formed (to May 1994, at least) a dense coral forest at St2-St3 (to ca. 255 colonies/ha at St3), and some isolated colonies (to ca. 0.9 colonies/ha) were still collected in 2011. Fish and invertebrate communities significantly differed between St1 and St2/St3, with two macrourid fishes (Trachrhynchus trachyrhynchus and Nezumia aequalis) and two decapods (Plesionika martia and Plesionika acanthonotus) more abundant at St2/St3. The following ecological indicators imply better food conditions for megafauna at St2-St3 and for I. elongata itself: (i) greater density of zooplankton (copepods, euphausiids, and others) as potential prey for planktivores (including I. elongata); (ii) greater biomass and mean weight of epifaunal and infaunal deposit feeders; (iii) higher feeding intensity, F, at St3 for benthos feeders (Phycis blennoides, N. aequalis and Aristeus antennatus). Also, at St2-St3 we found higher near-bottom turbidity (indicating particle resuspension: food for suspension feeders) and finer and more reduced (Eh) sediments. The results let us suggest that corals and accompanying fauna preferently found optimal ecological conditions in the same habitat, while habitat-forming capacity by I. elongata seemed weak to generate these conditions. Coral forests may enhance detritus accumulations around them, improving habitat conditions for benthos feeders (e.g. macrourid fish). At St3 our side-scan sonar recorded three types of tracks produced by trawler doors, which match with three identified vessels occasionally operating in the area. After this low fishing activity off the Ebro Delta since the mid-1990s, almost all colonies of I. elongata has been removed. However, this impact has hardly altered fish and invertebrate composition without any significant loss of diversity, pointing also toward a rather low capacity of I. elongata facies in forming habitat for megafauna on muddy bottoms of the Mediterranean slope.

Cartes, J. E.; LoIacono, C.; Mamouridis, V.; López-Pérez, C.; Rodríguez, P.

2013-06-01

381

Habitat patches & landscape in protecting species I. Habitat v. landscape  

E-print Network

1 Habitat patches & landscape in protecting species I. Habitat v. landscape II. The landscape on non-reserve lands Approaches to solving conservation problems I. Habitat v. landscapes in conservation A. Habitat ­ Habitat Selection ­ a species' use of a habitat type at frequencies that differ from

Dever, Jennifer A.

382

The Influence of Both Testing Environment and Fillet Radius of the Die Holder on the Rupture Life of Small Punch Creep Tests  

NASA Astrophysics Data System (ADS)

The small punch (SP) creep test has been proposed as a semi destructive testing methodology to examine the residual creep life of high temperature components. A series of SP creep tests were conducted on low alloy steel at 600°C both in air and in high vacuum to investigate the influences of both testing environment and the fillet radius of the lower die holder on the SP creep rupture life. The thickness of the oxide scale on the SP creep specimen in air increased with the test duration, e.g., about 30µm in thickness after a 400 hour exposure. The SP creep rupture life in air reduced to a half of the life in vacuum due to an increase in the actual stress in the specimen and also the coefficient of friction. In addition, the magnitude of the fillet radius at the lower die holder also affected the SP creep rupture life. The influence of the fillet radius on the SP creep rupture life was studied both experimentally and numerically. The SP creep rupture life with a smaller fillet radius of the lower die holder had twice the rupture life compared to that with a larger fillet radius. This effect was also demonstrated by the FE analysis.

Kobayashi, Ken-Ichi; Kaneko, Masahiro; Koyama, Hideo; Stratford, Gavin C.; Tabuchi, Masaaki

383

Biodiversity: Habitat Suitability  

EPA Science Inventory

Habitat suitability quantifies the relationship between species and habitat, and is evaluated according to the species? fitness (i.e. proportion of birth rate to death rate). Even though it might maximize evolutionary success, species are not always in habitat that optimizes fit...

384

Urban Areas. Habitat Pac.  

ERIC Educational Resources Information Center

The materials in this educational packet are designed for use with students in grades 4 through 7. They consist of an overview, teaching guides and student data sheets for three activities, and a poster. The overview discusses the city as an ecosystem, changing urban habitats, urban wildlife habitats, values of wildlife, habitat management, and…

Fish and Wildlife Service (Dept. of Interior), Washington, DC.

385

Estuary Habitat Restoration INTRODUCTION  

E-print Network

1 Estuary Habitat Restoration STRATEGY 2012 INTRODUCTION The Estuary Restoration Act of 2000 (ERA agencies to maximize benefits derived from estuary habitat restoration projects and address the pressures facing our nation's estuaries. The ERA established an inter-agency Estuary Habitat Restoration Council

US Army Corps of Engineers

386

POTENTAIL HABITAT MOUNTAIN PLOVERS  

E-print Network

POTENTAIL HABITAT FOR MOUNTAIN PLOVERS ON COLORADO SPRINGS UTILITIES PROPERTY A Report to Colorado). To identify potential habitat on current and future Colorado Springs Utilities property, the Utility funded a habitat survey conducted by the Colorado Natural Heritage Program at Colorado State University. METHODS

387

[Manic-depressive psychoses in adolescence. Influence of life change events. Study of family dynamics].  

PubMed

A sample of 38 adolescents hospitalized for a major depressive episode melancholic type or a manic episode during the course of a bipolar disorder (according to the DSM III-R Criteria) was examined with particular emphasis on precipating life events and family relationships. Psychosocial stressors in the year preceding onset of the affective disorder were found in a very high proportion of cases (about 80%). Stressors are most often severe. All of these stressors have to do with loss or threat of loss, particularly the most frequent one: the sentimental failure. Analyzing results of a familial dynamic questionnaire, we showed in the MDD sample the prevalence of two psychopathological index: maternal rejection, parental dysharmony. PMID:9035994

Corcos, M; Atger, F; Jeanneau, A; Benoit, S; Ficheux, P; Jeammet, P

1996-01-01

388

Influence of poplar clones on fertility life-table parameters of Chaitophorus leucomelas (Hemiptera: Aphididae).  

PubMed

The aphid Chaitophorus leucomelas Koch (Hemiptera: Aphididae) is one of the most important pests of poplar (Populus spp.) plantations in Iran. In this study, development, reproduction, and life history of the aphid were assessed on 11 poplar clones; belong to three species, Populus nigra L., Populus deltoides Bartram ex Marshall, and Populus. euramericana Guinier. The experiments were carried out under controlled conditions at 24 +/- 1 degrees C, 50-60% RH, and a photoperiod of 12:12 (L:D) h. The developmental time at immature stage ranged from 10 to 12 d. Nymphs reproduced per female were ranged from 49 to 98 nymphs on Populus deltoides var. missoriensis and P. deltoides 72/51, respectively. The intrinsic rate of natural increase (r(m)) varied from 0.176 to 0.264 d(-1) among poplar clones. The r(m) values of the aphids were adversely affected in P. euramericana 242 in comparison with P. nigra 56/72 and P. nigra 63/135. In addition, the jackknife estimates of net reproductive rate (R0) indicated the presence of resistance among poplar clones. R0 ranged from 16.48 on P. nigra var. betulifoli to 47.53 on P. nigra 63/135. Mean generation times (T) was last 17.56 d on P. euramericana 242 to 14.51 d on P. deltoides 69/55. However, doubling time (DT) was 3.87 d on P. euramericana var. grandis to 2.63 d on P. nigra 63/135. The finite rate of increase (lambda) was 1.192 on resistant clone (P. euramericana 242) and 1.302 on susceptible clone (P. nigra 63/135). These results indicate that variation in life-table parameters could be an important component of variation in resistance to C. leucomelas in poplar. PMID:21309247

Yali, M Pahlavan; Moharramipour, S; Sadeghi, S E; Razmjou, J

2010-12-01

389

Plant origin and ploidy influence gene expression and life cycle characteristics in an invasive weed  

PubMed Central

Background Ecological, evolutionary and physiological studies have thus far provided an incomplete picture of why some plants become invasive; therefore we used genomic resources to complement and advance this field. In order to gain insight into the invasive mechanism of Centaurea stoebe we compared plants of three geo-cytotypes, native Eurasian diploids, native Eurasian tetraploids and introduced North American tetraploids, grown in a common greenhouse environment. We monitored plant performance characteristics and life cycle habits and characterized the expression of genes related to constitutive defense and genome stability using quantitative PCR. Results Plant origin and ploidy were found to have a significant effect on both life cycle characteristics and gene expression, highlighting the importance of comparing appropriate taxonomic groups in studies of native and introduced plant species. We found that introduced populations of C. stoebe exhibit reduced expression of transcripts related to constitutive defense relative to their native tetraploid counterparts, as might be expected based on ideas of enemy release and rapid evolution. Measurements of several vegetative traits were similar for all geo-cytotypes; however, fecundity of tetraploids was significantly greater than diploids, due in part to their polycarpic nature. A simulation of seed production over time predicts that introduced tetraploids have the highest fecundity of the three geo-cytotypes. Conclusion Our results suggest that characterizing gene expression in an invasive species using populations from both its native and introduced range can provide insight into the biology of plant invasion that can complement traditional measurements of plant performance. In addition, these results highlight the importance of using appropriate taxonomic units in ecological genomics investigations. PMID:19309502

Broz, Amanda K; Manter, Daniel K; Bowman, Gillianne; Müller-Schärer, Heinz; Vivanco, Jorge M

2009-01-01

390

Generalisation of physical habitat-discharge relationships  

NASA Astrophysics Data System (ADS)

Physical habitat is increasingly used worldwide as a measure of river ecosystem health when assessing changes to river flows, such as those caused by abstraction. The major drawback with this approach is that defining precisely the relationships between physical habitat and flow for a given river reach requires considerable data collection and analysis. Consequently, widely used models such as the Physical Habitat Simulation (PHABSIM) system are expensive to apply. There is, thus, a demand for rapid methods for defining habitat-discharge relationships from simple field measurements. This paper reports the analysis of data from 63 sites in the UK where PHABSIM has been applied. The results demonstrate that there are strong relationships between single measurements of channel form and river hydraulics and the habitat available for target species. The results can form the basis of a method to estimate sensitivity of physical habitat to flow change by visiting a site at only one flow. Furthermore, the uncertainty in estimates reduces as more information is collected. This allows the user to select the level of investment in data collection appropriate for the desired confidence in the estimates. The method is demonstrated using habitat indicators for different life stages of Atlantic salmon, brown trout, roach and dace.

Booker, D. J.; Acreman, M. C.

2007-01-01

391

Landscape-stream interactions and habitat conservation for amphibians.  

PubMed

Semiaquatic organisms depend on the features of both water bodies and landscapes; the interplay between terrestrial and aquatic systems might influence the semiaquatic communities, determining the scale at which management would be more effective. However, the consequences of such interplay are not frequently quantified, particularly at the community level. We analyzed the distribution of amphibians to evaluate whether the influence of landscape features on freshwater ecosystems can have indirect consequences at both the species and community level. We surveyed 74 streams in northern Italy to obtain data on breeding amphibians, water, and microhabitat features; we also measured features of surrounding landscapes. We used an information-theoretic approach and structural equation models to compare hypotheses on causal relationships between species distribution and variables measured at multiple levels. We also used a constrained redundancy analyses to evaluate causal relationships between multivariate descriptors of habitat features and community composition. Distribution of Salamandra salamandra was related to landscape, hydrological, and water characteristics: salamanders were more frequent in permanent streams with low phosphate concentration within natural landscapes. Water characteristics were dependent on landscape: streams in natural landscapes had less phosphates. Landscape influenced the salamander both directly and indirectly through its influence on phosphates. Community structure was determined by both landscape and water characteristics. Several species were associated with natural landscapes, and with particular water characteristics. Landscape explained a significant proportion of variability of water characteristics; therefore it probably had indirect effects on community. Upland environments play key roles for amphibians, for example, as the habitat of adults, but upland environments also have indirect effects on the aquatic life stages, mediated through their influence on water characteristics. Synergistic effects can magnify the negative consequences of landscape alteration on amphibians; landscape management can be particularly effective, as it can also improve wetland features. PMID:21774429

Ficetola, Gentile Francesco; Marziali, Laura; Rossaro, Bruno; De Bernardi, Fiorenza; Padoa-Schioppa, Emilio

2011-06-01

392

Grasslands. Habitat Ecology Learning Program (HELP). Teachers' Manual.  

ERIC Educational Resources Information Center

The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

Wildlife Conservation Society, Bronx, NY.

393

Wetlands. Habitat Ecology Learning Program (HELP). Teachers' Manual.  

ERIC Educational Resources Information Center

The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

Wildlife Conservation Society, Bronx, NY.

394

Temperate Forests. Habitat Ecology Learning Program (HELP). Teachers' Manual.  

ERIC Educational Resources Information Center

The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

Wildlife Conservation Society, Bronx, NY.

395

Deserts. Habitat Ecology Learning Program (HELP). Teachers' Manual.  

ERIC Educational Resources Information Center

The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

Wildlife Conservation Society, Bronx, NY.

396

How Nature Works. Habitat Ecology Learning Program (HELP). Teachers' Manual.  

ERIC Educational Resources Information Center

The goal of this guide is to address a major environmental dilemma: worldwide habitat destruction and the disappearance of species. This guide is one of six that are included in the Habitat Ecology Learning Program (HELP), a holistic life science curriculum that involves students in an in-depth study of ecology. HELP includes six teaching guides…

Wildlife Conservation Society, Bronx, NY.

397

Population viability impacts of habitat additions and subtractions: A simulation experiment with endangered kangaroo rats  

EPA Science Inventory

Species viability is influenced by the quality, quantity and configuration of habitat. For species at risk, a principal challenge is to identify landscape configurations that, if realized, would improve a population?s viability or restoration potential. Critical habitat patche...

398

The influence of early life nutrition on epigenetic regulatory mechanisms of the immune system.  

PubMed

The immune system is exquisitely sensitive to environmental changes. Diet constitutes one of the major environmental factors that exerts a profound effect on immune system development and function. Epigenetics is the study of mitotically heritable, yet potentially reversible, molecular modifications to DNA and chromatin without alteration to the underlying DNA sequence. Nutriepigenomics is an emerging discipline examining the role of dietary influences on gene expression. There is increasing evidence that the epigenetic mechanisms that regulate gene expression during immune differentiation are directly affected by dietary factors or indirectly through modifications in gut microbiota induced by different dietary habits. Short-chain fatty acids, in particular butyrate, produced by selected bacteria stains within gut microbiota, are crucial players in this network. PMID:25353665

Paparo, Lorella; di Costanzo, Margherita; di Scala, Carmen; Cosenza, Linda; Leone, Ludovica; Nocerino, Rita; Canani, Roberto Berni

2014-11-01

399

Individual variation in life history characteristics can influence extinction risk (vol 144, pg 61, 2001) Correction  

SciTech Connect

The white sturgeon (Acipenser transmontanus) shows great individual variation in the age at maturation. This study examines the consequences of model assumptions about individual variation in the age at maturation on predicted population viability. I considered: (1) the effects of variation in age at maturation alone; (2) the effects of heritability; and (3) the influence of a stable and an altered selective regime. Two selective regimes represented conditions before and after the impoundment of a river, blocking access of anadromous white sturgeon populations to the ocean. In contrast to previous simulation studies, I found that increased individual variation in the age at maturity did not necessarily lead to a higher likelihood of persistence. Individual variation increased the simulated likelihood of persistence when the variation was heritable and the selective regime had changed such that the mean age at maturity was no longer optimal.

Jager, Yetta [ORNL

2009-01-01

400

Spatiotemporal patterns and habitat associations of smallmouth bass (Micropterus dolomieu) invading salmon-rearing habitat  

USGS Publications Warehouse

1. Smallmouth bass (Micropterus dolomieu) have been widely introduced to fresh waters throughout the world to promote recreational fishing opportunities. In the Pacific Northwest (U.S.A.), upstream range expansions of predatory bass, especially into subyearling salmon-rearing grounds, are of increasing conservation concern, yet have received little scientific inquiry. Understanding the habitat characteristics that influence bass distribution and the timing and extent of bass and salmon overlap will facilitate the development of management strategies that mitigate potential ecological impacts of bass. 2. We employed a spatially continuous sampling design to determine the extent of bass and subyearling Chinook salmon (Oncorhynchus tshawytscha) sympatry in the North Fork John Day River (NFJDR), a free-flowing river system in the Columbia River Basin that contains an upstream expanding population of non-native bass. Extensive (i.e. 53 km) surveys were conducted over 2 years and during an early and late summer period of each year, because these seasons provide a strong contrast in the river's water temperature and flow condition. Classification and regression trees were applied to determine the primary habitat correlates of bass abundance at reach and channel-unit scales. 3. Our study revealed that bass seasonally occupy up to 22%of the length of the mainstem NFJDR where subyearling Chinook salmon occur, and the primary period of sympatry between these species was in the early summer and not during peak water temperatures in late summer. Where these species co-occurred, bass occupied 60–76% of channel units used by subyearling Chinook salmon in the early summer and 28–46% of the channel units they occupied in the late summer. Because these rearing salmon were well below the gape limitation of bass, this overlap could result in either direct predation or sublethal effects of bass on subyearling Chinook salmon. The upstream extent of bass increased 10–23 km (2009 and 2010, respectively) as stream temperatures seasonally warmed, but subyearling Chinook salmon were also found farther upstream during this time. 4. Our multiscale analysis suggests that bass were selecting habitat based on antecedent thermal history at a broad scale, and if satisfactory temperature conditions were met, mesoscale habitat features (i.e. channel-unit type and depth) played an additional role in determining bass abundance. The upstream extent of bass in the late summer corresponded to a high-gradient geomorphic discontinuity in the NFJDR, which probably hindered further upstream movements of bass. The habitat determinants and upstream extent of bass were largely consistent across years, despite marked differences in the magnitude and timing of spring peak flows prior to bass spawning.5. The overriding influence of water temperature on smallmouth bass distribution suggests that managers may be able limit future upstream range expansions of bass into salmon-rearing habitat by concentrating on restoration activities that mitigate climate- or land-use-related stream warming. These management activities could be prioritised to capitalise on survival bottlenecks in the life history of bass and spatially focused on landscape knick points such as high-gradient discontinuities to discourage further upstream movements of bass.

Lawrence, David J.; Olden, Julian D.; Torgersen, Christian E.

2012-01-01

401

Correlation between spraying conditions and microcrack density and their influence on thermal cycling life of thermal barrier coatings  

NASA Astrophysics Data System (ADS)

It is generally known that the porosity of thermal barrier coatings is essential to guarantee a sufficiently high strain tolerance of the coating during thermal cycling. However, much less is known about the influence of the specific morphology of porosity, such as microcracks and typically larger pores, on the performance of the coatings. Both features are usually formed during plasma spraying of yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs). In this investigation, the influence of microcracks on the thermal cycling behavior was studied. The amount of microcracks within YSZ thermal barrier coatings was changed by changing the powder-feeding rate. Only small changes of the total porosity were observed. Mercury porosimetry served as a tool to investigate both the amount of microcracks and pores in the coating. Additionally, microcrack densities were determined from metallographical investigations. A linear dependence between the amount of fine pores determined by Hg porosimetry and the crack density was obtained for one set of coatings. Thermal cycling TBC specimens with different microcrack densities were produced and tested in a gas burner test facility. At high surface temperatures (above 1300 °C), failure occurred in the ceramic close to the surface. Under these conditions, the samples with increased horizontal microcrack densities showed a significant increase of thermal cycling life.

Vaßen, Robert; Traeger, Franziska; Stöver, Detlev

2004-09-01

402

Maternal and environmental influences on egg size and juvenile life-history traits in Pacific salmon.  

PubMed

Life-history traits such as fecundity and offspring size are shaped by investment trade-offs faced by mothers and mediated by environmental conditions. We use a 21-year time series for three populations of wild sockeye salmon (Oncorhynchus nerka) to test predictions for such trade-offs and responses to conditions faced by females during migration, and offspring during incubation. In years when their 1100 km upstream migration was challenged by high water discharges, females that reached spawning streams had invested less in gonads by producing smaller but not fewer eggs. These smaller eggs produced lighter juveniles, and this effect was further amplified in years when the incubation water was warm. This latter result suggests that there should be selection for larger eggs to compensate in populations that consistently experience warm incubation temperatures. A comparison among 16 populations, with matching migration and rearing environments but different incubation environments (i.e., separate spawning streams), confirmed this prediction; smaller females produced larger eggs for their size in warmer creeks. Taken together, these results reveal how maternal phenotype and environmental conditions can shape patterns of reproductive investment and consequently juvenile fitness-related traits within and among populations. PMID:23789081

Braun, Douglas C; Patterson, David A; Reynolds, John D

2013-06-01

403

Genetic structure in the Amazonian catfish Brachyplatystoma rousseauxii: influence of life history strategies.  

PubMed

The Dorado or Plateado (Gilded catfish) Brachyplatystoma rousseauxii (Pimelodidae, Siluriformes) is a commercially valuable migratory catfish performing the largest migration in freshwaters: from the Amazonian headwaters in the Andean foothills (breeding area) to the Amazon estuary (nursery area). In spite of its importance to inform management and conservation efforts, the genetic variability of this species has only recently begun to be studied. The aim of the present work was to determine the population genetic structure of B. rousseauxii in two regions: the Upper Madera Basin (five locations in the Bolivian Amazon) and the Western Amazon Basin (one regional sample from the Uyucalí-Napo-Marañon-Amazon basin, Peru). Length polymorphism at nine microsatellite loci (284 individuals) was used to determine genetic variability and to identify the most probable panmictic units (using a Bayesian approach), after a significant departure from Hardy-Weinberg equilibrium was observed in the overall dataset (Western Amazon + Upper Madera). Bayesian analyses revealed at least three clusters in admixture in the five locations sampled in the Bolivian Amazon, whereas only two of these clusters were observed in the Western Amazon. Considering the migratory behaviour of B. rousseauxii, different life history strategies, including homing, are proposed to explain the cluster distribution. Our results are discussed in the light of the numerous threats to the species survival in the Madera basin, in particular dam and reservoir construction. PMID:25038864

Carvajal-Vallejos, F M; Duponchelle, F; Desmarais, E; Cerqueira, F; Querouil, S; Nuñez, J; García, C; Renno, J-F

2014-08-01

404

Maternal and environmental influences on egg size and juvenile life-history traits in Pacific salmon  

PubMed Central

Life-history traits such as fecundity and offspring size are shaped by investment trade-offs faced by mothers and mediated by environmental conditions. We use a 21-year time series for three populations of wild sockeye salmon (Oncorhynchus nerka) to test predictions for such trade-offs and responses to conditions faced by females during migration, and offspring during incubation. In years when their 1100 km upstream migration was challenged by high water discharges, females that reached spawning streams had invested less in gonads by producing smaller but not fewer eggs. These smaller eggs produced lighter juveniles, and this effect was further amplified in years when the incubation water was warm. This latter result suggests that there should be selection for larger eggs to compensate in populations that consistently experience warm incubation temperatures. A comparison among 16 populations, with matching migration and rearing environments but different incubation environments (i.e., separate spawning streams), confirmed this prediction; smaller females produced larger eggs for their size in warmer creeks. Taken together, these results reveal how maternal phenotype and environmental conditions can shape patterns of reproductive investment and consequently juvenile fitness-related traits within and among populations. PMID:23789081

Braun, Douglas C; Patterson, David A; Reynolds, John D

2013-01-01

405

Geomorphic and Ecologic Interactions of Large Wood and Pacific Salmonid Redds Across Habitat Units on a Regulated California River  

NASA Astrophysics Data System (ADS)

Large wood pieces (LW, >1 m length, >10 cm diameter) are important components of geomorphic and ecologic dynamics within river systems. Physical presence of LW within a bankful channel can influence flow, sediment deposition and scour patterns, and storage of organic matter, whereas ecologic elements of LW include hydraulic variability, habitat, and nutrient sources for aquatic species. In regulated rivers hydrologic connectivity has been lost and ecosystem dynamics disrupted, yet lower reaches continue to serve as habitat, and now as headwaters, for a myriad of species including anadromous salmonids returning to spawn and complete their life-cycles. Regardless of condition, lower reaches of regulated rivers must serve as ecosystem hotspots in response to anthropogenic manipulations of the watershed. In this research, interactions between large wood, Pacific salmonid redds, and aquatic habitat units (i.e. riffle, run, glide, and pool as defined by depth and velocity) were explored in a regulated, mid-sized (i.e. channel width is greater than most tree heights), Mediterranean-climate (i.e. smaller, softer-wood trees dominate the landscape) river draining a portion of the Sierra Nevada of California. Because watershed connectivity has been severed, riparian zones highly altered, and LW removal remains common, LW levels are thought to be very low in regulated ecosystems. The study hypothesis was that a dynamic and healthy ecosystem might have areas of low, optimal, and overabundances of wood, which would correlate to low, optimal, and low redd abundances, respectively. On the other hand, in an ecosystem where connectivity is diminished, an increase in the amount of LW may potentially convert otherwise unsuitable spawning habitat to highly preferred spawning habitat. In exploring the dynamics of wood and redds at the habitat unit scale, characteristics of 530 LW pieces, locations of 650 redds, and habitat units along a 7.5 km reach directly below a dam were mapped during a spawning season. Findings suggest that fall-run Chinook salmon preferentially spawned in riffles often where LW was present, but also spawned in glides and occasionally runs, and across all these habitats both with and without LW. No spawning was observed in pools. LW was present in all habitat types, but not in every habitat unit occurrence. There were no areas in the study reach with an overabundance (i.e. complete coverage of channel bed) of LW, nor did LW presence appear to prohibit redd activity in spawning habitats. Further research is needed to determine what quantities of LW might be considered optimal in below-dam ecosystems where suitable spawning habitat is needed.

Senter, A. E.; Pasternack, G. B.

2007-12-01