Search Results
Results 201 - 250 of 335
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Stern Gary A - - 2011
Recent studies have shown that climate change is already having significant impacts on many aspects of transport pathways, speciation and cycling of mercury within Arctic ecosystems. For example, the extensive loss of sea-ice in the Arctic Ocean and the concurrent shift from greater proportions of perennial to annual types have ...
Adams Douglas H - - 2011
Stable-isotope ratios (δ(13)C and δ(15)N) and mercury in a model predator, and associated prey community assessments were used to make inferences regarding food web relationships and how these relationships are influenced by habitat variability and anthropogenic factors. Although interconnected, the three major basins of the Indian River Lagoon system on ...
Zhang Liang - - 2012
Seasonal variation in mercury (Hg) concentrations and food web structure was assessed for eastern Lake Ontario. Hg concentrations, measured in 6 species of invertebrates and 8 species of fishes, tended to be highest in the spring and lowest in the summer for most biota. Yellow perch (Perca flavescens) exhibited significant ...
Internicola Antonina I - - 2012
Most rewardless orchids engage in generalized food-deception, exhibiting floral traits typical of rewarding species and exploiting the instinctive foraging of pollinators. Generalized food-deceptive (GFD) orchids compete poorly with rewarding species for pollinator services, which may be overcome by flowering early in the growing season when relatively more pollinators are naive ...
Eklöf Anna - - 2012
Explaining the structure of ecosystems is one of the great challenges of ecology. Simple models for food web structure aim at disentangling the complexity of ecological interaction networks and detect the main forces that are responsible for their shape. Trophic interactions are influenced by species traits, which in turn are ...
Visser André W - - 2012
We examine the effect of adaptive foraging behaviour within a tri-trophic food web with intra-guild predation. The intra-guild prey is allowed to adjust its foraging effort so as to achieve an optimal per capita growth rate in the face of realized feeding, predation risk and foraging cost. Adaptive fitness-seeking behaviour ...
Eckert Ester M - - 2011
The vernal successions of phytoplankton, heterotrophic nanoflagellates (HNF) and viruses in temperate lakes result in alternating dominance of top-down and bottom-up factors on the bacterial community. This may lead to asynchronous blooms of bacteria with different life strategies and affect the channelling of particular components of the dissolved organic matter ...
Hogsden Kristy L - - 2011
We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food ...
Pillai Pradeep - - 2011
Food webs are highly complex ecological networks, dynamic in both space and time. Metacommunity models are now at the core of unified theories of biodiversity, but to date they have not addressed food web complexity. Here we show that metacommunity theory can explain the emergence of species-rich food webs with ...
Aguirre-Macedo María Leopoldina - - 2011
In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). ...
Glanz Karen - - 2012
The Nutrient Rich Foods (NRF) approach to eating uses the NRF Index, a nutrient profiling metric to help consumers choose foods that contain more vitamins, minerals, and other nutrients per kilocalorie. Research is needed to test the efficacy of dietary guidance using nutrient profiling systems to rank foods. To examine ...
Layman Craig A - - 2011
Stable isotope analysis has emerged as one of the primary means for examining the structure and dynamics of food webs, and numerous analytical approaches are now commonly used in the field. Techniques range from simple, qualitative inferences based on the isotopic niche, to Bayesian mixing models that can be used ...
Rundgren Shu-Nu Chang - - 2011
Based upon the goal of scientific literacy and the importance of socioscientific issues (SSIs), the purpose of this study was to investigate the Taiwanese public's awareness of, inclinations to buy/use, and their attitudes towards three attributes of SSIs including genetically modified food (GM food), organic food, and DDT and malaria ...
Emmerson Mark C - - 2011
[Formula: see text] [ The sap-feeding plant bug Lopidea media is a specialist on Solidago goldenrod plants. The study by Schmitz and Price compares the interaction strengths of this and several other sap-feeding and leaf- chewing insect herbivores in experimentally assembled food webs in a Connecticut USA meadow. Photo courtesy ...
Roach Katherine A - - 2011
Photoautotrophs are generally considered to be the base of food webs, and habitats that lack light, such as caves, frequently rely on surface-derived carbon. Here we show, based on analysis of gut contents and stable isotope ratios of tissues (13C:12C and 15N:14N), that sulfur-oxidizing bacteria are directly consumed and assimilated ...
Hoekman David - - 2011
Aquatic insects are a common and important subsidy to terrestrial systems, yet little is known about how these inputs affect terrestrial food webs, especially around lakes. Mývatn, a lake in northern Iceland, has extraordinary midge (Chironomidae) emergences that result in large inputs of biomass and nutrients to terrestrial arthropod communities. ...
Upadhyay Atul - - 2012
Pineapple stem has been extensively used for bromelain extraction; however, almost no attention has been given to the waste obtained during bromelain manufacturing. In this regard, antioxidant, antimicrobial, and inhibitions against 15-lipoxygenase and advanced glycation end product formations by pineapple stem waste (PSW) obtained during bromelain manufacturing process were studied. ...
Spink John - - 2011
Food fraud, including the more defined subcategory of economically motivated adulteration, is a food risk that is gaining recognition and concern. Regardless of the cause of the food risk, adulteration of food is both an industry and a government responsibility. Food safety, food fraud, and food defense incidents can create ...
Stephansen Diana A - - 2011
The concentrations and patterns of persistent halogenated compounds (PHCs), including polychlorinated biphenyls (PCBs), DDT, hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and polybrominated diphenyl ethers (PBDEs) were examined in a pelagic food web from the southern Baltic Sea consisting of sediment, zooplankton, sprat, Atlantic salmon and anadromous brown trout. Lipid-normalized concentrations generally increased ...
Altintas Hande - - 2011
Currently, filling, smoothing, or recontouring the face through the use of injectable fillers is one of the most popular forms of cosmetic surgery. Because these materials promise a more youthful appearance without anesthesia in a noninvasive way, various fillers have been used widely in different parts of the world. However, ...
Arab Lenore - - 2011
To date, Web-based 24-hour recalls have not been validated using objective biomarkers. From 2006 to 2009, the validity of 6 Web-based DietDay 24-hour recalls was tested among 115 black and 118 white healthy adults from Los Angeles, California, by using the doubly labeled water method, and the results were compared ...
Saldanha Leila G - - 2012
Food composition databases are critical to assess and plan dietary intakes. Dietary supplement databases are also needed because dietary supplements make significant contributions to total nutrient intakes. However, no uniform system exists for classifying dietary supplement products and indexing their ingredients in such databases. Differing approaches to classifying these products ...
Liu Bian - - 2012
We examined Hg biogeochemistry in Baihua Reservoir, a system affected by industrial wastewater containing mercury (Hg). As expected, we found high levels of total Hg (THg, 664-7421 ng g(-1)) and monomethylmercury (MMHg, 3-21 ng g(-1)) in the surface sediments (0-10 cm). In the water column, both THg and MMHg showed ...
Hightower Jane M - - 2011
ABSTRACT: BACKGROUND: Dried meat and fish have served as an important durable nutrition source for humans for centuries. Because omega 3 fatty acids in fish are recognized as having antioxidant and anti inflammatory properties found to be beneficial for good health, many consumers are looking to fish as their main ...
Jardine Timothy D - - 2011
High levels of hydrological connectivity during seasonal flooding provide significant opportunities for movements of fish between rivers and their floodplains, estuaries and the sea, possibly mediating food web subsidies among habitats. To determine the degree of utilisation of food sources from different habitats in a tropical river with a short ...
Scully Maree - - 2011
The present study examined associations between food marketing exposure and adolescents' food choices and reported consumption of energy-dense and nutrient-poor (EDNP) foods. A cross-sectional survey of 12,188 Australian secondary students aged 12-17years was conducted, using a web-based self-report questionnaire. Measures included students' level of exposure to commercial television and non-broadcast ...
Bartels Pia - - 2011
Cross-ecosystem movements of material and energy are ubiquitous. Aquatic ecosystems typically receive material that also includes organic matter from the surrounding catchment. Terrestrial-derived (allochthonous) organic matter can enter aquatic ecosystems in dissolved or particulate form. Several studies have highlighted the importance of dissolved organic carbon to aquatic consumers, but less ...
Deribe Ermias - - 2011
The concentrations and bioaccumulation of persistent organic pollutants (POPs) were determined in four fish species from Lake Koka, Ethiopia, representing 2-3 levels in the food chain of the lake. Dichlorodiphenyltrichloroethanes (DDTs), endosulfans, polychlorinated biphenyls (PCBs) and chlorpyrifos were identified, with DDTs as the most predominant pesticide, with concentration ranging from ...
Rotheram-Borus Mary Jane MJ Department of Psychiatry, University of California, Los Angeles, - - 2011
The effects of a community popular opinion leader (CPOL) intervention were examined among market vendors in a city on the eastern coast of China. Employees of 40 food markets were enrolled in a study that provided HIV-related education and tests, and treatment for sexually transmitted diseases (STDs). Twenty markets were ...
Nfon Erick - - 2011
A dynamic combined fate and food web model was developed to estimate the food web transfer of chemicals in small aquatic ecosystems (i.e. ponds). A novel feature of the modeling approach is that aquatic macrophytes (submerged aquatic vegetation) were included in the fate model and were also a food item ...
Poulsen Anita H - - 2011
Persistent organic pollutants (POPs) have been frequently measured throughout the Southern Ocean food web for which little information is available to assess the potential risks of POP exposure. The current study evaluated the toxicological sensitivity of a key Southern Ocean species, Antarctic krill, to aqueous exposure of p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE). ...
Davenport Jon M - - 2011
1. Many taxa can be found in food webs that differ in trophic complexity, but it is unclear how trophic complexity affects the performance of particular taxa. In pond food webs, larvae of the salamander Ambystoma opacum occupy the intermediate predator trophic position in a partial intraguild predation (IGP) food web ...
Rooney Neil N School of Environmental Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada. - - 2012
Given the unprecedented rate of species extinctions facing the planet, understanding the causes and consequences of species diversity in ecosystems is of paramount importance. Ecologists have investigated both the influence of environmental variables on species diversity and the influence of species diversity on ecosystem function and stability. These investigations have ...
Labonté M-È - - 2011
Background/Objectives:To assess the validity and the reproducibility of a newly developed web-based, self-administered food frequency questionnaire (web-FFQ).Subjects/Methods:A total of 74 healthy subjects (34 men and 40 women) from the Québec City metropolitan area were asked to complete, in random order, the web-FFQ, a validated interviewer-administered FFQ (IA-FFQ) and a 3-day ...
Viganò Luigi - - 2011
Decabromodiphenyl ether (BDE-209), the primary constituent of a widely used flame retardant formulation, is present at relatively high levels in sediments and macroinvertebrates of the River Po. Since it was demonstrated that BDE-209 can be biotransformed to smaller and more toxic polybrominated dipheyl ethers (PBDEs), the main objective of this ...
Weiss Bernard - - 2012
The proposition that synthetic food colors can induce adverse behavioral effects in children was first enunciated in 1975 by Feingold [Why Your Child Is Hyperactive. New York:Random House (1975)], who asserted that elevated sensitivity to food additives underlies the signs of hyperactivity observed in some children. Although the evidence suggested ...
Risse-Buhl Ute - - 2011
Food webs in the rhithral zone rely mainly on allochthonous carbon from the riparian vegetation. However, autochthonous carbon might be more important in open canopy streams. In streams, most of the microbial activity occurs in biofilms, associated with the streambed. We followed the autochthonous carbon transfer toward bacteria and grazing ...
Papi Luigi - - 2011
Nerium oleander is a very popular urban ornamental plant in Europe, but it is also extremely dangerous because it contains several types of glycosides, accidental ingestion of which can cause cardiac arrhythmias and even deaths.The rarity of such cases makes it difficult to think of oleander poisoning without evidences that ...
França Susana - - 2011
Stable carbon and nitrogen isotopes (δ(13)C, δ(15)N) were used to analyse food web dynamics of two of the main estuaries of the Portuguese coast: Tejo and Mira. The ultimate sources of organic matter supporting production of some of the most abundant and commercially important fish species were determined; and seasonal, ...
Mùˆller Claudia E - - 2011
The biomagnification behavior of perfluorinated carboxylates (PFCAs) and perfluorinated sulfonates (PFSAs) was studied in terrestrial food webs consisting of lichen and plants, caribou, and wolves from two remote northern areas in Canada. Six PFCAs with eight to thirteen carbons and perfluorooctane sulfonate (PFOS) were regularly detected in all species. Lowest ...
Chiu Grace S - - 2011
A food web consists of nodes, each consisting of one or more species. The role of each node as predator or prey determines the trophic relations that weave the web. Much effort in trophic food web research is given to understand the connectivity structure, or the nature and degree of ...
Qureshi Naema - - 2011
Although studies have yet to prove definitively a causal relationship between diet and acne, the lay public has traditionally held that such causality exists. The authors' study aims to determine which nutritional elements are thought to be related to acne, both positively and negatively. YouTube, a popular video-sharing Web site, ...
Baillie Jonathan - - 2011
An independent survey into hospital food standards in England conducted earlier this year for the Soil Association saw over half of those patients surveyed admit they would not be happy serving the meals they received during a recent hospital stay to a child, while 29% said the food was so ...
Abrams Peter A - - 2011
Abstract This article analyzes the nature of top-down and bottom-up effects and alternative states in systems characterized by life-history omnivory. The analysis is based on a three-species food web with intraguild predation (IGP). The top predator population has juvenile and adult stages, which consume the basal resource and the intermediate ...
Goodman Samantha - - 2011
To examine longitudinal trends in use of nutrition information among Canadians. Population-based telephone and Internet surveys. Representative samples of Canadian adults recruited with random-digit dialing sampling in 2004 (n = 2,405) and 2006 (n = 2,014) and an online commercial panel in 2008 (n = 2,001). Sociodemographic predictors of label ...
Williams Richard J - - 2011
The structure of food webs, complex networks of interspecies feeding interactions, plays a crucial role in ecosystem resilience and function, and understanding food web structure remains a central problem in ecology. Previous studies have shown that key features of empirical food webs can be reproduced by low-dimensional "niche" models. Here ...
Cross Wyatt F - - 2011
Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, U.S.A., ...
Skatrud-Mickelson Monica - - 2011
Television viewing is associated with an increased risk in childhood obesity. Research surrounding food habits of tweens largely bypasses snacking preferences while watching television in the home. The aim of this cross-sectional study was to describe snacking prevalence by tween sex and to describe parental rules surrounding snacking while watching ...
Nevitt Gabrielle A - - 2011
Information transfer influences food-web dynamics in the marine environment, but infochemicals involved in these processes are only beginning to be understood. Dimethylsulfoniopropionate (DMSP) is produced by phytoplankton and other marine algae, and has been studied primarily in the context of sulfur cycling and regulation of global climate. My laboratory has ...
Di Beneditto Ana Paula Madeira - - 2011
The present study raised the hypothesis that the trophic status in a tropical coastal food web from southeastern Brazil can be measured by the relation between total mercury (THg) and nitrogen isotope (δ(15)N) in their components. The analysed species were grouped into six trophic positions: primary producer (phytoplankton), primary consumer ...
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