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Sample records for larval food affects

  1. Drosophila adult and larval pheromones modulate larval food choice.

    Science.gov (United States)

    Farine, Jean-Pierre; Cortot, Jérôme; Ferveur, Jean-François

    2014-06-07

    Insects use chemosensory cues to feed and mate. In Drosophila, the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured their influence on larval food preference and puparation behaviour. We also tested compounds that varied between these species: (i) two larval volatile compounds: hydroxy-3-butanone-2 and phenol (predominant in D. simulans and D. buzzatii, respectively), and (ii) adult cuticular hydrocarbons (CHs). Drosophila buzzatii larvae were rapidly attracted to non-CH adult conspecific cues, whereas D. simulans larvae were strongly repulsed by CHs of the two species and also by phenol. Larval cues from both species generally reduced larval attraction and pupariation on food, which was generally--but not always--low, and rarely reflected larval response. As these larval and adult pheromones specifically influence larval food search and the choice of a pupariation site, they may greatly affect the dispersion and survival of Drosophila species in nature.

  2. Larval food quantity affects development time, survival and adult biological traits that influence the vectorial capacity of Anopheles darlingi under laboratory conditions

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    Araújo Maisa

    2012-08-01

    Full Text Available Abstract Background The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology. However, in order develop effective control strategies and laboratory breeding conditions for this species, more data on the factors affecting vector biology is needed. The aim of the present study is to assess the effects of larval food quantity on the vectorial capacity of An. darling under laboratory conditions. Methods Anopheles darlingi was maintained at 28°C, 80% humidity and exposed to a daily photoperiod of 12 h. Larvae were divided into three experimental groups that were fed either a low, medium, or high food supply (based on the food amounts consumed by other species of culicids. Each experiment was replicated for six times. A cohort of adults were also exposed to each type of diet and assessed for several biological characteristics (e.g. longevity, bite frequency and survivorship, which were used to estimate the vectorial capacity of each experimental group. Results The group supplied with higher food amounts observed a reduction in development time while larval survival increased. In addition to enhanced longevity, increasing larval food quantity was positively correlated with increasing frequency of bites, longer blood meal duration and wing length, resulting in greater vectorial capacity. However, females had greater longevity than males despite having smaller wings. Conclusions Overall, several larval and adult biological traits were significantly

  3. Food quality affects secondary consumers even at low quantities: an experimental test with larval European lobster.

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    Schoo, Katherina L; Aberle, Nicole; Malzahn, Arne M; Boersma, Maarten

    2012-01-01

    The issues of food quality and food quantity are crucial for trophic interactions. Although most research has focussed on the primary producer-herbivore link, recent studies have shown that quality effects at the bottom of the food web propagate to higher trophic levels. Negative effects of poor food quality have almost exclusively been demonstrated at higher food quantities. Whether these negative effects have the same impact at low food availability in situations where the majority if not all of the resources are channelled into routine metabolism, is under debate. In this study a tri-trophic food chain was designed, consisting of the algae Rhodomonas salina, the copepod Acartia tonsa and freshly hatched larvae of the European lobster Homarus gammarus. The lobster larvae were presented with food of two different qualities (C:P ratios) and four different quantities to investigate the combined effects of food quality and quantity. Our results show that the quality of food has an impact on the condition of lobster larvae even at very low food quantities. Food with a lower C:P content resulted in higher condition of the lobster larvae regardless of the quantity of food. These interacting effects of food quality and food quantity can have far reaching consequences for ecosystem productivity.

  4. Protein and carbohydrate composition of larval food affects tolerance tothermal stress and desiccation in adult Drosophila melanogaster

    DEFF Research Database (Denmark)

    Andersen, Laila H; Kristensen, Torsten N; Loeschcke, Volker

    2010-01-01

    Larval nutrition may affect a range of different life history traits as well as responses to environmental stress in adult insects. Here we test whether raising larvae of fruit flies, Drosophila melanogaster, on two different nutritional regimes affects resistance to cold, heat and desiccation...

  5. Aquatic microfauna alter larval food resources and affect development and biomass of West Nile and Saint Louis encephalitis vector Culex nigripalpus (Diptera: Culicidae).

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    Duguma, Dagne; Kaufman, Michael G; Simas Domingos, Arthur B

    2017-05-01

    Ciliate protists and rotifers are ubiquitous in aquatic habitats and can comprise a significant portion of the microbial food resources available to larval mosquitoes, often showing substantial declines in abundance in the presence of mosquito larvae. This top-down regulation of protists is reported to be strong for mosquitoes inhabiting small aquatic containers such as pitcher plants or tree holes, but the nature of these interactions with larval mosquitoes developing in other aquatic habitats is poorly understood. We examined the effects of these two microbial groups on lower trophic level microbial food resources, such as bacteria, small flagellates, and organic particles, in the water column, and on Culex larval development and adult production. In three independent laboratory experiments using two microeukaryote species (one ciliate protist and one rotifer) acquired from field larval mosquito habitats and cultured in the laboratory, we determined the effects of Culex nigripalpus larval grazing on water column microbial dynamics, while simultaneously monitoring larval growth and development. The results revealed previously unknown interactions that were different from the top-down regulation of microbial groups by mosquito larvae in other systems. Both ciliates and rotifers, singly or in combination, altered other microbial populations and inhibited mosquito growth. It is likely that these microeukaryotes, instead of serving as food resources, competed with early instar mosquito larvae for microbes such as small flagellates and bacteria in a density-dependent manner. These findings help our understanding of the basic larval biology of Culex mosquitoes, variation in mosquito production among various larval habitats, and may have implications for existing vector control strategies and for developing novel microbial-based control methods.

  6. Effect of Larval Density on Food Utilization Efficiency of Tenebrio molitor (Coleoptera: Tenebrionidae).

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    Morales-Ramos, Juan A; Rojas, M Guadalupe

    2015-10-01

    Crowding conditions of larvae may have a significant impact on commercial production efficiency of some insects, such as Tenebrio molitor L. (Coleoptera: Tenebrionidae). Although larval densities are known to affect developmental time and growth in T. molitor, no reports were found on the effects of crowding on food utilization. The effect of larval density on food utilization efficiency of T. molitor larvae was studied by measuring efficiency of ingested food conversion (ECI), efficiency of digested food conversion (EDC), and mg of larval weight gain per gram of food consumed (LWGpFC) at increasing larval densities (12, 24, 36, 48, 50, 62, 74, and 96 larvae per dm(2)) over four consecutive 3-wk periods. Individual larval weight gain and food consumption were negatively impacted by larval density. Similarly, ECI, ECD, and LWGpFC were negatively impacted by larval density. Larval ageing, measured as four consecutive 3-wk periods, significantly and independently impacted ECI, ECD, and LWGpFC in a negative way. General linear model analysis showed that age had a higher impact than density on food utilization parameters of T. molitor larvae. Larval growth was determined to be responsible for the age effects, as measurements of larval mass density (in grams of larvae per dm(2)) had a significant impact on food utilization parameters across ages and density treatments (in number of larvae per dm(2)). The importance of mass versus numbers per unit of area as measurements of larval density and the implications of negative effects of density on food utilization for insect biomass production are discussed.

  7. Effects of moisture content of food waste on residue separation, larval growth and larval survival in black soldier fly bioconversion.

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    Cheng, Jack Y K; Chiu, Sam L H; Lo, Irene M C

    2017-09-01

    In order to foster sustainable management of food waste, innovations in food waste valorization technologies are crucial. Black soldier fly (BSF) bioconversion is an emerging technology that can turn food waste into high-protein fish feed through the use of BSF larvae. The conventional method of BSF bioconversion is to feed BSF larvae with food waste directly without any moisture adjustment. However, it was reported that difficulty has been experienced in the separation of the residue (larval excreta and undigested material) from the insect biomass due to excessive moisture. In addition to the residue separation problem, the moisture content of the food waste may also affect the growth and survival aspects of BSF larvae. This study aims to determine the most suitable moisture content of food waste that can improve residue separation as well as evaluate the effects of the moisture content of food waste on larval growth and survival. In this study, pre-consumer and post-consumer food waste with different moisture content (70%, 75% and 80%) was fed to BSF larvae in a temperature-controlled rotary drum reactor. The results show that the residue can be effectively separated from the insect biomass by sieving using a 2.36mm sieve, for both types of food waste at 70% and 75% moisture content. However, sieving of the residue was not feasible for food waste at 80% moisture content. On the other hand, reduced moisture content of food waste was found to slow down larval growth. Hence, there is a trade-off between the sieving efficiency of the residue and the larval growth rate. Furthermore, the larval survival rate was not affected by the moisture content of food waste. A high larval survival rate of at least 95% was achieved using a temperature-controlled rotary drum reactor for all treatment groups. The study provides valuable insights for the waste management industry on understanding the effects of moisture content when employing BSF bioconversion for food waste recycling

  8. Larval intraspecific competition for food in the European grapevine moth Lobesia botrana.

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    Thiéry, D; Monceau, K; Moreau, J

    2014-08-01

    Effective pest management with lower amounts of pesticides relies on accurate prediction of insect pest growth rates. Knowledge of the factors governing this trait and the resulting fitness of individuals is thus necessary to refine predictions and make suitable decisions in crop protection. The European grapevine moth, Lobesia botrana, the major pest of grapes in Europe, is responsible for huge economic losses. Larvae very rarely leave the grape bunch on which they were oviposited and thus cannot avoid intraspecific competition. In this study, we determined the impact of intraspecific competition during the larval stage on development and adult fitness in this species. This was tested by rearing different numbers of larvae on an artificial diet and measuring developmental and reproductive life history traits. We found that intraspecific competition during larval development has a slight impact on the fitness of L. botrana. The principal finding of this work is that larval density has little effect on the life history traits of survivors. Thus, the timing of eclosion, duration of subsequent oviposition, fecundity appears to be more uniform in L. botrana than in other species. The main effect of larval crowding was a strong increase of larval mortality at high densities whereas the probability of emergence, sex ratio, pupal mass, fecundity and longevity of mated females were not affected by larval crowding. Owing to increased larval mortality at high larval densities, we hypothesized that mortality of larvae at high densities provided better access to food for the survivors with the result that more food was available per capita and there were no effect on fitness of survivors. From our results, larval crowding alters the reproductive capacity of this pest less than expected but this single factor should now be tested in interaction with limited resources in the wild.

  9. Larval Temperature-Food Effects on Adult Mosquito Infection and Vertical Transmission of Dengue-1 Virus.

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    Buckner, Eva A; Alto, Barry W; Lounibos, L Philip

    2016-01-01

    Temperature-food interactions in the larval environment can affect life history and population growth of container mosquitoes Aedes aegypti (L.) and Aedes albopictus Skuse, the primary vectors of chikungunya and dengue viruses. We used Ae. aegypti, Ae. albopictus, and dengue-1 virus (DENV-1) from Florida to investigate whether larval rearing temperature can alter the effects of larval food levels on Ae. aegypti and Ae. albopictus life history and DENV-1 infection and vertical transmission. Although we found no effect of larval treatments on survivorship to adulthood, DENV-1 titer, or DENV-1 vertical transmission, rates of vertical transmission up to 16-24% were observed in Ae. albopictus and Ae. aegypti, which may contribute to maintenance of this virus in nature. Larval treatments had no effect on number of progeny and DENV-1 infection in Ae. aegypti, but the interaction between temperature and food affected number of progeny and DENV-1 infection of the female Ae. albopictus parent. The cooler temperature (24°C) yielded the most progeny and this effect was accentuated by high food relative to the other conditions. Low and high food led to the highest (∼90%) and lowest (∼65%) parental infection at the cooler temperature, respectively, whereas intermediate infection rates (∼75-80%) were observed for all food conditions at the elevated temperature. These results suggest that temperature and food availability have minimal influence on rate of vertical transmission and a stronger influence on adults of Ae. albopictus than of Ae. aegypti, which could have consequences for dengue virus epidemiology. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Food selection in larval fruit flies: dynamics and effects on larval development

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    Schwarz, Sebastian; Durisko, Zachary; Dukas, Reuven

    2014-01-01

    Selecting food items and attaining a nutritionally balanced diet is an important challenge for all animals including humans. We aimed to establish fruit fly larvae ( Drosophila melanogaster) as a simple yet powerful model system for examining the mechanisms of specific hunger and diet selection. In two lab experiments with artificial diets, we found that larvae deprived of either sucrose or protein later selectively fed on a diet providing the missing nutrient. When allowed to freely move between two adjacent food patches, larvae surprisingly preferred to settle on one patch containing yeast and ignored the patch providing sucrose. Moreover, when allowed to move freely between three patches, which provided either yeast only, sucrose only or a balanced mixture of yeast and sucrose, the majority of larvae settled on the yeast-plus-sucrose patch and about one third chose to feed on the yeast only food. While protein (yeast) is essential for development, we also quantified larval success on diets with or without sucrose and show that larvae develop faster on diets containing sucrose. Our data suggest that fruit fly larvae can quickly assess major nutrients in food and seek a diet providing a missing nutrient. The larvae, however, probably prefer to quickly dig into a single food substrate for enhanced protection over achieving an optimal diet.

  11. Maternal cortisol stimulates neurogenesis and affects larval behaviour in zebrafish

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    Best, Carol; Kurrasch, Deborah M.; Vijayan, Mathilakath M.

    2017-01-01

    Excess glucocorticoid transferred from stressed mother to the embryo affects developing vertebrate offspring, but the underlying programming events are unclear. In this study, we tested the hypothesis that increased zygotic glucocorticoid deposition, mimicking a maternal stress scenario, modifies early brain development and larval behaviour in zebrafish (Danio rerio). Cortisol was microinjected into the yolk at one cell-stage, to mimic maternal transfer, and the larvae [96 hours post-fertilization (hpf)] displayed increased activity in light and a reduction in thigmotaxis, a behavioural model for anxiety, suggesting an increased propensity for boldness. This cortisol-mediated behavioural phenotype corresponded with an increase in primary neurogenesis, as measured by incorporation of EdU at 24 hpf, in a region-specific manner in the preoptic region and the pallium, the teleostean homolog of the hippocampus. Also, cortisol increased the expression of the proneural gene neurod4, a marker of neurogenesis, in a region- and development-specific manner in the embryos. Altogether, excess zygotic cortisol, mimicking maternal stress, affects early brain development and behavioural phenotype in larval zebrafish. We propose a key role for cortisol in altering brain development leading to enhanced boldness, which may be beneficial in preparing the offspring to a stressful environment and enhancing fitness. PMID:28098234

  12. Maternal cortisol stimulates neurogenesis and affects larval behaviour in zebrafish.

    Science.gov (United States)

    Best, Carol; Kurrasch, Deborah M; Vijayan, Mathilakath M

    2017-01-18

    Excess glucocorticoid transferred from stressed mother to the embryo affects developing vertebrate offspring, but the underlying programming events are unclear. In this study, we tested the hypothesis that increased zygotic glucocorticoid deposition, mimicking a maternal stress scenario, modifies early brain development and larval behaviour in zebrafish (Danio rerio). Cortisol was microinjected into the yolk at one cell-stage, to mimic maternal transfer, and the larvae [96 hours post-fertilization (hpf)] displayed increased activity in light and a reduction in thigmotaxis, a behavioural model for anxiety, suggesting an increased propensity for boldness. This cortisol-mediated behavioural phenotype corresponded with an increase in primary neurogenesis, as measured by incorporation of EdU at 24 hpf, in a region-specific manner in the preoptic region and the pallium, the teleostean homolog of the hippocampus. Also, cortisol increased the expression of the proneural gene neurod4, a marker of neurogenesis, in a region- and development-specific manner in the embryos. Altogether, excess zygotic cortisol, mimicking maternal stress, affects early brain development and behavioural phenotype in larval zebrafish. We propose a key role for cortisol in altering brain development leading to enhanced boldness, which may be beneficial in preparing the offspring to a stressful environment and enhancing fitness.

  13. Drosophila Food-Associated Pheromones: Effect of Experience, Genotype and Antibiotics on Larval Behavior.

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    Thibert, Julien; Farine, Jean-Pierre; Cortot, Jérôme; Ferveur, Jean-François

    2016-01-01

    Animals ubiquitously use chemical signals to communicate many aspects of their social life. These chemical signals often consist of environmental cues mixed with species-specific signals-pheromones-emitted by conspecifics. During their life, insects can use pheromones to aggregate, disperse, choose a mate, or find the most suitable food source on which to lay eggs. Before pupariation, larvae of several Drosophila species migrate to food sources depending on their composition and the presence of pheromones. Some pheromones derive from microbiota gut activity and these food-associated cues can enhance larval attraction or repulsion. To explore the mechanisms underlying the preference (attraction/repulsion) to these cues and clarify their effect, we manipulated factors potentially involved in larval response. In particular, we found that the (i) early exposure to conspecifics, (ii) genotype, and (iii) antibiotic treatment changed D. melanogaster larval behavior. Generally, larvae-tested either individually or in groups-strongly avoided food processed by other larvae. Compared to previous reports on larval attractive pheromones, our data suggest that such attractive effects are largely masked by food-associated compounds eliciting larval aversion. The antagonistic effect of attractive vs. aversive compounds could modulate larval choice of a pupariation site and impact the dispersion of individuals in nature.

  14. Rearing Tenebrio molitor in BLSS: Dietary fiber affects larval growth, development, and respiration characteristics

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    Li, Leyuan; Stasiak, Michael; Li, Liang; Xie, Beizhen; Fu, Yuming; Gidzinski, Danuta; Dixon, Mike; Liu, Hong

    2016-01-01

    Rearing of yellow mealworm (Tenebrio molitor L.) will provide good animal nutrition for astronauts in a bioregenerative life support system. In this study, growth and biomass conversion data of T. molitor larvae were tested for calculating the stoichiometric equation of its growth. Result of a respiratory quotient test proved the validity of the equation. Fiber had the most reduction in mass during T. molitor‧s consumption, and thus it is speculated that fiber is an important factor affecting larval growth of T. molitor. In order to further confirm this hypothesis and find out a proper feed fiber content, T. molitor larvae were fed on diets with 4 levels of fiber. Larval growth, development and respiration in each group were compared and analyzed. Results showed that crude-fiber content of 5% had a significant promoting effect on larvae in early instars, and is beneficial for pupa eclosion. When fed on feed of 5-10% crude-fiber, larvae in later instars reached optimal levels in growth, development and respiration. Therefore, we suggest that crude fiber content in feed can be controlled within 5-10%, and with the consideration of food palatability, a crude fiber of 5% is advisable.

  15. Effects of habitat fragmentation on abundance, larval food and parasitism of a spider-hunting wasp.

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    Coudrain, Valérie; Herzog, Felix; Entling, Martin H

    2013-01-01

    Habitat fragmentation strongly affects species distribution and abundance. However, mechanisms underlying fragmentation effects often remain unresolved. Potential mechanisms are (1) reduced dispersal of a species or (2) altered species interactions in fragmented landscapes. We studied if abundance of the spider-hunting and cavity-nesting wasp Trypoxylon figulus Linnaeus (Hymenoptera: Crabronidae) is affected by fragmentation, and then tested for any effect of larval food (bottom up regulation) and parasitism (top down regulation). Trap nests of T. figulus were studied in 30 agricultural landscapes of the Swiss Plateau. The sites varied in the level of isolation from forest (adjacent, in the open landscape but connected, isolated) and in the amount of woody habitat (from 4% to 74%). We recorded wasp abundance (number of occupied reed tubes), determined parasitism of brood cells and analysed the diversity and abundance of spiders that were deposited as larval food. Abundances of T. figulus were negatively related to forest cover in the landscape. In addition, T. figulus abundances were highest at forest edges, reduced by 33.1% in connected sites and by 79.4% in isolated sites. The mean number of spiders per brood cell was lowest in isolated sites. Nevertheless, structural equation modelling revealed that this did not directly determine wasp abundance. Parasitism was neither related to the amount of woody habitat nor to isolation and did not change with host density. Therefore, our study showed that the abundance of T. figulus cannot be fully explained by the studied trophic interactions. Further factors, such as dispersal and habitat preference, seem to play a role in the population dynamics of this widespread secondary carnivore in agricultural landscapes.

  16. Rising CO2 concentrations affect settlement behaviour of larval damselfishes

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    Devine, B. M.; Munday, P. L.; Jones, G. P.

    2012-03-01

    Reef fish larvae actively select preferred benthic habitat, relying on olfactory, visual and acoustic cues to discriminate between microhabitats at settlement. Recent studies show exposure to elevated carbon dioxide (CO2) impairs olfactory cue recognition in larval reef fishes. However, whether this alters the behaviour of settling fish or disrupts habitat selection is unknown. Here, the effect of elevated CO2 on larval behaviour and habitat selection at settlement was tested in three species of damselfishes (family Pomacentridae) that differ in their pattern of habitat use: Pomacentrus amboinensis (a habitat generalist), Pomacentrus chrysurus (a rubble specialist) and Pomacentrus moluccensis (a live coral specialist). Settlement-stage larvae were exposed to current-day CO2 levels or CO2 concentrations that could occur by 2100 (700 and 850 ppm) based on IPCC emission scenarios. First, pair-wise choice tests were performed using a two-channel flume chamber to test olfactory discrimination between hard coral, soft coral and coral rubble habitats. The habitat selected by settling fish was then compared among treatments using a multi-choice settlement experiment conducted overnight. Finally, settlement timing between treatments was compared across two lunar cycles for one of the species, P. chrysurus. Exposure to elevated CO2 disrupted the ability of larvae to discriminate between habitat odours in olfactory trials. However, this had no effect on the habitats selected at settlement when all sensory cues were available. The timing of settlement was dramatically altered by CO2 exposure, with control fish exhibiting peak settlement around the new moon, whereas fish exposed to 850 ppm CO2 displaying highest settlement rates around the full moon. These results suggest larvae can rely on other sensory information, such as visual cues, to compensate for impaired olfactory ability when selecting settlement habitat at small spatial scales. However, rising CO2 could cause larvae

  17. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

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    Takken Willem

    2010-01-01

    Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

  18. Larval starvation reduces responsiveness to feeding stimuli and does not affect feeding preferences in a butterfly.

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    Kehl, Tobias; Fischer, Klaus

    2012-07-01

    It is commonly assumed that holometabolic insects such as Lepidoptera rely primarily on larval storage reserves for reproduction. Recent studies though have documented a prominent role of adult-derived carbohydrates for butterfly reproduction. Moreover, a few studies have shown that adult butterflies may also benefit from adult-derived amino acids, at least when larval storage reserves are reduced. Given that in holometabolous insects larval deficiencies are carried over into the adult stage, reduced storage reserves have the potential to modulate adult feeding preferences and responses in order to allow for a successful compensation. We tested this hypothesis here in the fruit-feeding butterfly Bicyclus anynana using larval food stress to manipulate storage reserves. Alcohols (methanol, ethanol, butanol, propanol), sugars (maltose, glucose, fructose, sucrose), and acetic acid acted as feeding stimuli, while butterflies did not respond to other substances such as amino acids, yeast, salts, or vitamins. Contrary to expectations, stressed butterflies showed a weaker response than controls to several feeding stimuli. In preference tests, butterflies preferred sugar solutions containing proline, arginine, glutamic acid, acetic acid, or ethanol over plain sugar solutions, but discriminated against salts. However, there were no general differences among starved and control butterflies. We conclude that larval food-stress does not elicit compensatory feeding behavior such as a stronger preference for amino acids or other essential nutrients in B. anynana. Instead, the stress imposed by a period of starvation yielded negative effects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Larval growth in the dominant polychaete Polydora ciliata is food-limited in a eutrophic Danish estuary (Isefjord)

    DEFF Research Database (Denmark)

    Pedersen, Troels Møller; Almeda, Rodrigo; Fotel, Frank Lech;

    2010-01-01

    Food limitation in larval growth of the spionid polychaete Polydora ciliata was examined in a typical eutrophic estuary, Isefjord, in Denmark. In the field, food availability and the energetic requirements of the P. ciliata larval population were measured during 2 different periods in 2004 and 20...

  20. Influence of food concentration, temperature and salinity on the larval development of Balanus amphitrite

    Digital Repository Service at National Institute of Oceanography (India)

    Anil, A.C.; Kurian, J.

    Influence of food concentration (0.5, 1 and 2 x 10 sup(5) cell ml sup(-1) of Skeletonema costatum), temperature (20 and 30 degrees C) and salinity (15, 25 and 35 ppt) on the larval development of Balanus amphitrite (Cirripedia: Thoracica...

  1. Food of larval Anopheles culicifacies and Anopheles varuna in a stream habitat in Sri Lanka

    DEFF Research Database (Denmark)

    Piyaratne, M K; Amerasinghe, P H; Amerasinghe, F P

    2005-01-01

    No previous studies have been conducted on the natural food of larval Anopheles culicifacies s.l. (the major malaria vector) and An. varuna (a secondary vector) in Sri Lanka. The present study analyzed the contents of guts dissected from larvae collected from pools in a natural stream-cum-irrigat...

  2. The parasitoid, Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), influences food consumption and utilization by larval Diatraea saccharalis (F.) (Lepidoptera: Crambidae).

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    Rossi, Guilherme Duarte; Salvador, Gabriela; Cônsoli, Fernando Luis

    2014-10-01

    Parasitoids exploit host insects for food and other resources; they alter host development and physiology to optimize conditions to favor parasitoid development. Parasitoids influence their hosts by injecting eggs, along with a variety of substances, including venoms, polydnaviruses, ovarian fluids, and other maternal factors, into hosts. These factors induce profound changes in hosts, such as behavior, metabolism, endocrine events, and immune defense. Because endoparasitoids develop and consume tissues from within their hosts, it is reasonable to suggest that internal parasitization would also influence host food consumption and metabolism. We report on the effects of parasitism by Cotesia flavipes on the food consumption and utilization of its host, Diatraea saccharalis. Cotesia flavipes reduces the host food consumption, but parasitized larvae considered a unit with their parasitoid's attained the same final weight as the nonparasitized larvae. Nutritional indices, midgut activities of carbohydrases, and trypsin of parasitized and nonparasitized D. saccharalis were assessed. Parasitized larvae had reduced relative food consumption, metabolic and growth rates, coupled with higher efficiency for conversion of the digested, but not ingested, food into body mass. Parasitism also affected food flux through the gut and protein contents in the midgut of parasitized larvae. The activity of α-amylase and trehalase in parasitized host was enhanced in the first day after parasitism relative to control larvae. Saccharase activity remained unchanged during larval development. Trypsin activity was reduced from the fifth to ninth day after parasitism. We argue on the mechanisms involved in host food processing after parasitism.

  3. Food aroma affects bite size

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    de Wijk René A

    2012-03-01

    Full Text Available Abstract Background To evaluate the effect of food aroma on bite size, a semisolid vanilla custard dessert was delivered repeatedly into the mouth of test subjects using a pump while various concentrations of cream aroma were presented retronasally to the nose. Termination of the pump, which determined bite size, was controlled by the subject via a push button. Over 30 trials with 10 subjects, the custard was presented randomly either without an aroma, or with aromas presented below or near the detection threshold. Results Results for ten subjects (four females and six males, aged between 26 and 50 years, indicated that aroma intensity affected the size of the corresponding bite as well as that of subsequent bites. Higher aroma intensities resulted in significantly smaller sizes. Conclusions These results suggest that bite size control during eating is a highly dynamic process affected by the sensations experienced during the current and previous bites.

  4. The impact of food type, temperature and starvation on larval development of Balanus amphitrite Darwin (Cirripedia: Thoracica)

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, D.V.; Anil, A.C.

    The impact of diatom food species (Chaetoceros calcitrans and Skeletonema costatum), temperature and starvation on the larval development of Balanus amphitrite was evaluated. Starvation threshold levels for different ages of larvae (0- to 5-day...

  5. Aedes aegypti pharate 1st instar quiescence affects larval fitness and metal tolerance.

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    Perez, Mario H; Noriega, Fernando G

    2012-06-01

    The eggs of the mosquito Aedes aegypti possess the ability to undergo an extended quiescence hosting a fully developed 1st instar larvae within the chorion. As a result of this life history trait pharate larvae can withstand months of quiescence inside the egg where they depend on stored maternal reserves. A. aegypti mosquitoes are frequently associated with urban habitats that may contain significant metal pollution. Therefore, the duration of quiescence and extent of nutritional depletion may affect the physiology and survival of larvae that hatch in a suboptimal habitat. The aim of this study was to determine the effect of an extended quiescence on larval nutrient reserves and the subsequent effects of metal exposure on larval fitness, survival and development. We hypothesized that an extended quiescence would reduce nutritional reserves and alter the molecular response to metal exposure thereby reducing larval survival and altering larval development. As a molecular marker for metal stress responses, we evaluated transcriptional changes in the metallothionein gene (AaMtn) in response to quiescence and metal exposure. Extended 1st instar quiescence resulted in a significant decrease in lipid reserves and negatively affected larval fitness and development. AaMtn transcription and metal tolerance were compromised in first instars emerged from eggs that had undergone an extended quiescence. These findings suggest that newly emerged mosquito larvae that had survived a relatively long pharate 1st instar quiescence (as might occur during a dry season) are more vulnerable to environmental stress. Pharate 1st instar quiescence could have implications for vector control strategies. Newly emerged mosquito larvae at the end of the dry season or start of the wet season are physiologically compromised, and therefore potentially more susceptible to vector control strategies than mosquito larvae hatched subsequently throughout the wet season. Published by Elsevier Ltd.

  6. Performance of five food regimes on Anopheles gambiae senso stricto larval rearing to adult emergence in insectary.

    Directory of Open Access Journals (Sweden)

    Happiness S Kivuyo

    Full Text Available BACKGROUND: Rearing of Anopheles gambiae s.s mosquitoes in insectary with quality cheap food sources is of paramount importance for better and healthy colony. This study evaluated larval survival and the development rate of aquatic stages of An.gambiae s.s under five food regimes; tetramin fish food (a standard insectary larval food, maize pollen, Cerelac, green filamentous algae and dry powdered filamentous algae. METHODS: Food materials were obtained from different sources, cerelac was made locally, fresh filamentous algae was taken from water bodies, dry filamentous algae was ground to powder after it was dried under shade, and maize pollen was collected from the flowering maize. Each food source type was used to feed three densities of mosquito larvae 20, 60, and 100 in six replicates each. Larval age structure was monitored daily until pupation and subsequently adult emergence. Tetramin was used and taken as a standard food source for An. gambiae s.s. larvae feeding in Insectary. RESULTS: Larval survivorship using maize pollen and Tetramin fish food was statistically insignificant (P = 0.564. However when compared to other food regime survivorship was significantly different with Tetramin fish food performing better than cerelac (P<0.001, dry algae (P<0.001 and fresh algae (P<0.001. The pupation rates and sex ratio of emerging adults had significant differences among the food regimes. CONCLUSION: The findings of this study have shown that maize pollen had closely similar nutritional value for larval survivorship to tetramin fish food, a standard larvae food in insectary. Further studies are required to assess the effect of food sources on various life traits of the emerged adults.

  7. Copper affects biofilm inductiveness to larval settlement of the serpulid polychaete Hydroides elegans (Haswell)

    KAUST Repository

    Bao, Wei Yang

    2010-01-01

    Copper (Cu) contamination is a potential threat to the marine environment due to the use of Cu-based antifouling paints. Cu stress on larval settlement of the polychaete Hydroides elegans was investigated, and this was linked to Cu stress on biofilms and on the biofilm development process. The inductiveness of young biofilms was more easily altered by Cu stress than that of old biofilms, indicating the relative vulnerability of young biofilms. This might result from changes in bacterial survival, the bacterial community composition and the chemical profiles of young biofilms. Cu also affected biofilm development and the chemical high performance liquid chromatograph fingerprint profile. The results indicate that Cu affected larval settlement mainly through its effect on the process of biofilm development in the marine environment, and the chemical profile was crucial to biofilm inductiveness. It is strongly recommended that the effects of environmentally toxic substances on biofilms are evaluated in ecotoxicity bioassays using larval settlement of invertebrates as the end point. © 2010 Taylor & Francis.

  8. Population regulation of a tropical damselfly in the larval stage by food limitation, cannibalism, intraguild predation and habitat drying.

    Science.gov (United States)

    Fincke, Ola M

    1994-11-01

    experimentally prevented, competition for food reduced the growth of one or both larvae relative to controls. Holes that were watered during the dry season supported larval densities similar to those in the wet season. Thus, dry season mortality could not be attributed to a decrease in available prey. Rather, M. coerulatus larvae could not survive more than 1 month of complete drying. Because the dry season typically lasts more than 6 weeks, habitat drying is a secondary source of mortality, affecting second- or third-generation larvae that fail to emerge before tree holes dry out completely.

  9. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

  10. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    NARCIS (Netherlands)

    Bukhari, T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

    2010-01-01

    Background: Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (specie

  11. Larval exposure to azadirachtin affects fitness and oviposition site preference of Drosophila melanogaster.

    Science.gov (United States)

    Bezzar-Bendjazia, Radia; Kilani-Morakchi, Samira; Aribi, Nadia

    2016-10-01

    Azadirachtin, a biorational insecticide, is one of the prominent biopesticide commercialized today and represent an alternative to conventional insecticides. The current study examined the lethal and sublethal effects of azadirachtin on Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae) as biological model. Various doses ranging from 0.1 to 2μg were applied topically on early third instar larvae and the cumulative mortality of immature stage was determined. In second series of experiments, azadirachtin was applied at its LD25 (0.28μg) and LD50 (0.67μg) and evaluated on fitness (development duration, fecundity, adult survival) and oviposition site preference with and without choice. Results showed that azadirachtin increased significantly at the two tested doses the duration of larval and pupal development. Moreover, azadirachtin treatment reduced significantly adult's survival of both sex as compared to control. In addition, azadirachtin affected fecundity of flies by a significant reduction of the number of eggs laid. Finally results showed that females present clear preference for oviposition in control medium. Pre-imaginal exposure (L3) to azadirachtin increased aversion to this substance suggesting a memorability of the learned avoidance. The results provide some evidence that larval exposure to azadirachtin altered adult oviposition preference as well as major fitness traits of D. melanogaster. Theses finding may reinforce behavioural avoidance of azadirachtin and contribute as repellent strategies in integrated pest management programmes.

  12. Factors affecting food selection in Canadian population.

    Science.gov (United States)

    Ree, M; Riediger, N; Moghadasian, M H

    2008-11-01

    To establish health-related reasons behind Canadian food choices, and how variables such as education, income, gender, ethnicity and age may affect food selection. Approximately 98 733 Canadians responded to the 12 questions regarding food choices in the Canadian Community Health Survey (CCHS) cycle 2.1, conducted by the Canadian Government in 2003. These included 13 727 adolescents (12-19 years), 19 089 young adults (20-34 years), 31 039 middle-aged adults (35-54 years), 25 338 older adults (55-74 years) and 9580 elderly (75+ years). Approximately 70% of Canadian adolescents in the sample indicated that their food choices were independent of health concerns. Body weight management was a major concern for food selection by adolescents and adults, while the elderly stated heart disease as their main concern. Among all participants, females, and individuals with high levels of education and income reported the highest response to choosing or avoiding foods due to health concerns and food content. Our data indicate that several factors significantly affect food choices for health-related reasons in the Canadian population. Among them, age- and gender-related gaps, particularly between adolescents and adults, are profound. This observation may urge authorities to implement effective strategies to educate Canadians, especially adolescents, that selection of appropriate foods may prevent chronic diseases.

  13. Dietary TAG source and level affect performance and lipase expression in larval sea bass (Dicentrarchus labrax).

    Science.gov (United States)

    Morais, S; Cahu, C; Zambonino-Lnfante, J L; Robin, J; Rønnestad, I; Dinis, M T; Conceição, L E C

    2004-05-01

    The influence of dietary TAG source (fish oil, triolein, and coconut oil) and level (7.5 and 15% of the diet) on growth, lipase activity, and mRNA level was studied in sea bass larvae, from mouth opening until day 24 and from day 37 to 52. Fish oil and triolein induced better growth in both experiments, this being significant at a higher dietary level. Coconut oil significantly decreased growth at the higher level, possibly as the result of an excessive supply of medium-chain TAG. Growth was not related to lipase specific activity, suggesting a production in excess to dietary needs. Body lipid content was positively related to dietary lipid level and was affected by lipid quality. In addition, larval FA composition generally reflected that of the diet. The source of dietary lipid, but not the quantity, was shown to affect lipase activity significantly. Coconut oil diets induced the highest lipase activity, whereas the effect of fish oil was age dependent-it was similar to coconut oil at day 24 but induced the lowest lipase activity in 52-d-old larvae. The differential lipase response was probably caused by differences in the FA composition of the diet, related to the specificity of lipase toward FA differing in chain length and degree of saturation. No significant differences were found in lipase/glyceraldehyde-3-phosphate dehydrogenase mRNA, which suggests the existence of a posttranscriptional regulation mechanism.

  14. Larval connectivity of pearl oyster through biophysical modelling; evidence of food limitation and broodstock effect

    Science.gov (United States)

    Thomas, Yoann; Dumas, Franck; Andréfouët, Serge

    2016-12-01

    The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia atoll lagoons. This aquaculture relies on spat collection, a process that experiences spatial and temporal variability and needs to be optimized by understanding which factors influence recruitment. Here, we investigate the sensitivity of P. margaritifera larval dispersal to both physical and biological factors in the lagoon of Ahe atoll. Coupling a validated 3D larval dispersal model, a bioenergetics larval growth model following the Dynamic Energy Budget (DEB) theory, and a population dynamics model, the variability of lagoon-scale connectivity patterns and recruitment potential is investigated. The relative contribution of reared and wild broodstock to the lagoon-scale recruitment potential is also investigated. Sensitivity analyses pointed out the major effect of the broodstock population structure as well as the sensitivity to larval mortality rate and inter-individual growth variability to larval supply and to the subsequent settlement potential. The application of the growth model clarifies how trophic conditions determine the larval supply and connectivity patterns. These results provide new cues to understand the dynamics of bottom-dwelling populations in atoll lagoons, their recruitment, and discuss how to take advantage of these findings and numerical models for pearl oyster management.

  15. Diet and density dependent competition affect larval performance and oviposition site selection in the mosquito species Aedes albopictus (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Yoshioka Miho

    2012-10-01

    Full Text Available Abstract Background Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container and conspecific density (CD; number of pre-existing larvae of the same species. Immature development (larval mortality, development time to pupation and time to emergence and fitness (measured as wing length were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water and CD (0, 20, 40 and 80 larvae/300 ml water. Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1. Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P . Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding

  16. Ethanol affects the development of sensory hair cells in larval zebrafish (Danio rerio.

    Directory of Open Access Journals (Sweden)

    Phillip M Uribe

    Full Text Available Children born to mothers with substantial alcohol consumption during pregnancy can present a number of morphological, cognitive, and sensory abnormalities, including hearing deficits, collectively known as fetal alcohol syndrome (FAS. The goal of this study was to determine if the zebrafish lateral line could be used to study sensory hair cell abnormalities caused by exposure to ethanol during embryogenesis. Some lateral line sensory hair cells are present at 2 days post-fertilization (dpf and are functional by 5 dpf. Zebrafish embryos were raised in fish water supplemented with varying concentrations of ethanol (0.75%-1.75% by volume from 2 dpf through 5 dpf. Ethanol treatment during development resulted in many physical abnormalities characteristic of FAS in humans. Also, the number of sensory hair cells decreased as the concentration of ethanol increased in a dose-dependent manner. The dye FM 1-43FX was used to detect the presence of functional mechanotransduction channels. The percentage of FM 1-43-labeled hair cells decreased as the concentration of ethanol increased. Methanol treatment did not affect the development of hair cells. The cell cycle markers proliferating cell nuclear antigen (PCNA and bromodeoxyuridine (BrdU demonstrated that ethanol reduced the number of sensory hair cells, as a consequence of decreased cellular proliferation. There was also a significant increase in the rate of apoptosis, as determined by TUNEL-labeling, in neuromasts following ethanol treatment during larval development. Therefore, zebrafish are a useful animal model to study the effects of hair cell developmental disorders associated with FAS.

  17. The larval development of Habronema muscae (Nematoda: Habronematidae) affects its intermediate host, Musca domestica (Diptera: Muscidae).

    Science.gov (United States)

    Schuster, Rolf Karl; Sivakumar, Saritha

    2017-02-01

    Although the life cycle of the equid stomach parasite Habronema muscae was disclosed more than 100 years ago, little is known about the effect of the developing nematode larvae in its intermediate host, Musca domestica. In a series of experiments, freshly hatched M. domestica larvae were exposed to H. muscae eggs contained in a faecal sample of a naturally infected horse. In daily intervals, 50 fly larvae were removed and transferred on a parasite-free larval rearing medium where they completed their development. Hatched flies were examined for the presence of Habronema third-stage larvae. In two subsequent control groups, flies spend their entire larval life in contaminated horse faeces and in a parasite-free larval rearing medium, respectively. Out of the 700 fly larvae used in the infection experiments, 304 developed into adult flies of which 281 were infected. The average nematode larval burden rose from 3.6 in the group with the shortest exposure to more than 25 in the groups with the longest exposure. The proportion of larvae that developed into the adult insect fell from 82 % in the uninfected control group to 27 % in the positive control group. The pupae of the positive control group were smaller and lighter than those of the uninfected control group. Lower pupal size and weight in the positive control group as well as a lower insect developing rate might be attributed to the destruction of adipose cells in the maggots by Habronema larvae.

  18. Drosophila clueless is highly expressed in larval neuroblasts, affects mitochondrial localization and suppresses mitochondrial oxidative damage.

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    Aditya Sen

    Full Text Available Mitochondria are critical for neuronal function due to the high demand of ATP in these cell types. During Drosophila development, neuroblasts in the larval brain divide asymmetrically to populate the adult central nervous system. While many of the proteins responsible for maintaining neuroblast cell fate and asymmetric cell divisions are known, little is know about the role of metabolism and mitochondria in neuroblast division and maintenance. The gene clueless (clu has been previously shown to be important for mitochondrial function. clu mutant adults have severely shortened lifespans and are highly uncoordinated. Part of their lack of coordination is due to defects in muscle, however, in this study we have identified high levels of Clu expression in larval neuroblasts and other regions of the dividing larval brain. We show while mitochondria in clu mutant neuroblasts are mislocalized during the cell cycle, surprisingly, overall brain morphology appears to be normal. This is explained by our observation that clu mutant larvae have normal levels of ATP and do not suffer oxidative damage, in sharp contrast to clu mutant adults. Mutations in two other genes encoding mitochondrial proteins, technical knockout and stress sensitive B, do not cause neuroblast mitochondrial mislocalization, even though technical knockout mutant larvae suffer oxidative damage. These results suggest Clu functions upstream of electron transport and oxidative phosphorylation, has a role in suppressing oxidative damage in the cell, and that lack of Clu's specific function causes mitochondria to mislocalize. These results also support the previous observation that larval development relies on aerobic glycolysis, rather than oxidative phosphorylation. Thus Clu's role in mitochondrial function is not critical during larval development, but is important for pupae and adults.

  19. Effects of microcosm scaling and food resources on growth and survival of larval Culex pipiens

    Directory of Open Access Journals (Sweden)

    Paradise Christopher J

    2001-08-01

    Full Text Available Abstract Background We used a simple experimental design to test for the effects of microcosm scaling on the growth and survival of the mosquito, Culex pipiens. Microcosm and mesocosm studies are commonly used in ecology, and there is often an assumption that scaling doesn't affect experimental outcomes. The assumption is implicit in the design; choice of mesocosms may be arbitrary or based on convenience or cost. We tested the hypothesis that scale would influence larvae due to depth and surface area effects. Larvae were predicted to perform poorly in microcosms that were both deep and had small openings, due to buildup of waste products, less exchange with the environment, and increased competition. To determine if the choice of scale affected responses to other factors, we independently varied leaf litter quantity, whose effects on mosquitoes are well known. Results We found adverse effects of both a lower wall surface area and lower horizontal surface area, but microcosm scale interacted with resources such that C. pipiens is affected by habitat size only when food resources are scarce. At low resource levels mosquitoes were fewer, but larger, in microcosms with smaller horizontal surface area and greater depth than in microcosms with greater horizontal surface area and shallower depth. Microcosms with more vertical surface area/volume often produced larger mosquitoes; more food may have been available since mosquitoes browse on walls and other substrates for food. Conclusions The interaction between habitat size and food abundance is consequential to aquatic animals, and choice of scale in experiments may affect results. Varying surface area and depth causes the scale effect, with small horizontal surface area and large depth decreasing matter exchange with the surrounding environment. In addition, fewer resources leads to less leaf surface area, and the effects of varying surface area will be greater under conditions of limiting resources

  20. Grape variety affects larval performance and also female reproductive performance of the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Moreau, J; Benrey, B; Thiéry, D

    2006-04-01

    For insect herbivores, the quality of the larval host plant is a key determinant of fitness. Therefore, insect populations are supposed to be positively correlated with the nutritional quality of their host plant. This study aimed to determine if and how different varieties of grapes (including the wild grape Lambrusque) affect both larval and adult performance of the polyphagous European grapevine moth Lobesia botrana (Denis & Schiffermüller). Significant differences were found in larval development time, but not in pupal mass, adult emergence rate, or sex ratio. Although the fecundity of females is not different among varieties, females fed on some varieties produced eggs of different sizes which are correlated to their fertility. Thus, females adapt resource allocation to eggs depending on their diet as larvae. Using a fitness index, the average reproductive output was found to be highest for females reared on cv. Chardonnay. Females reared on wild grape produced a fitness index identical to the cultivated grapes. However, Lambrusque and Gewurztraminer separate themselves from the cultivated varieties according to our discriminant analyses. It is emphasized, through this study, that cultivars fed on by larvae should be considered in the population dynamics of L. botrana and that egg number is insufficient to determine host plant quality.

  1. Exposure to domoic acid affects larval development of king scallop Pecten maximus (Linnaeus, 1758).

    Science.gov (United States)

    Liu, Hui; Kelly, Maeve S; Campbell, Dirk A; Dong, Shuang Lin; Zhu, Jian Xin; Wang, Su Feng

    2007-02-28

    Domoic acid (DA) is a highly toxic phycotoxin produced by bloom forming marine diatoms Pseudo-nitzschia spp. Bivalves can accumulate this toxin to a high level through their feeding activities, and thus illness or death in can occur in consumers of bivalves. In this study, king scallop, Pecten maximus, larvae were exposed to dissolved domoic acid (DA) for 25d, and the toxin accumulation and effects of harbouring this toxin were investigated. Scallop larvae incorporated DA continuously during the larval culture period and accumulated a maximum DA level of 5.21pgind(-1) when exposed to a solution of 50ngml(-1) dissolved DA. As a result of the DA treatment, larval growth, measured in terms of shell length and the appearance of the eye-spot, and larval survival were significantly compromised. This is the first study on DA incorporation dynamics in P. maximus larvae, signifying the potential of using shellfish larvae for the study on mechanisms of phycotoxin accumulation. The negative effect of DA exposure suggests that this toxin could possibly influence natural recruitment in P. maximus, and it may be necessary to protect hatchery-cultured scallop larvae from DA during toxic Pseudo-nitzschia blooms.

  2. How Microorganisms Affect Food Safety and Quality

    OpenAIRE

    Bacon, Karleigh

    2012-01-01

    The main methods of preservation for shelf-stable foods are controlling the water activity or lowering the pH. Factors are often combined, like lowering pH AND using refrigeration. Understanding how food supports the growth of microorganisms can help improve both food safety AND food quality. This guide can help you manipulate your food to create a safe product.

  3. Grass Pollen Affects Survival and Development of Larval Anopheles arabiensis (Diptera: Culicidae)

    Science.gov (United States)

    Asmare, Yelfwagash; Hopkins, Richard J; Tekie, Habte; Hill, Sharon R

    2017-01-01

    Abstract Nutrients in breeding sites are critical for the survival and development of malaria mosquitoes, having a direct impact on vectorial capacity. Yet, there is a limited understanding about the natural larval diet and its impact on the individual fitness of mosquitoes. Recent studies have shown that gravid Anopheles arabiensis Patton (Diptera: Culicidae) are attracted by and oviposit in grass-associated habitats. The pollen provided by these grasses is a potential source of nutrients for the larvae. Here, we assess the effect of Typha latifolia L. (Poales: Typhaceae), Echinochloa pyramidalis Lamarck, Pennisetum setaceum Forsskål, and Zea mays L. pollen on larval survival and rate of development in An. arabiensis under laboratory conditions. In addition, we characterize the carbon to nitrogen ratio and the size of pollen grains as a measure of diet quality. Carbon-rich pollen with a small grain size (T. latifolia and P. setaceum; 9.7 ± 0.3 × 103 and 5.5 ± 0.2 × 104 µm3, respectively) resulted in enhanced rates of development of An. arabiensis. In contrast, the larva fed on the nitrogen-rich control diet (TetraMin) was slower to develop, but demonstrated the highest larval survival. Larvae fed on carbon-rich and large-grained Z. mays pollen (4.1 ± 0.2 × 105 µm3) survived at similar levels as those fed on the control diet and also took a longer time to develop compared with larvae fed on the other pollens. While males and females did not appear to develop differently on the different pollen diets, males consistently emerged faster than their female counterparts. These results are discussed in relation to integrated vector management.

  4. Elements affecting food waste in the food service sector.

    Science.gov (United States)

    Heikkilä, Lotta; Reinikainen, Anu; Katajajuuri, Juha-Matti; Silvennoinen, Kirsi; Hartikainen, Hanna

    2016-10-01

    Avoidable food waste is produced in the food service sector, with significant ecological and economical impacts. In order to understand and explain better the complex issue of food waste a qualitative study was conducted on the reasons for its generation in restaurants and catering businesses. Research data were collected during three participatory workshops for personnel from three different catering sector companies in Finland. Based on synthesized qualitative content analysis, eight elements influencing production and reduction of food waste were identified. Results revealed the diversity of managing food waste in the food service sector and how a holistic approach is required to prevent and reduce it. It is crucial to understand that food waste is manageable and should be an integral component of the management system. The model of eight factors provides a framework for recognition and management of food waste in the food service sector.

  5. Trichobaris weevils distinguish amongst toxic host plants by sensing volatiles that do not affect larval performance.

    Science.gov (United States)

    Lee, Gisuk; Joo, Youngsung; Diezel, Celia; Lee, Eun Ju; Baldwin, Ian T; Kim, Sang-Gyu

    2016-07-01

    Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviours are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically relevant interactions. Here, we examined the host-selection behaviours of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field and glasshouse experiments with transgenic host plants specifically altered in different components of their secondary metabolism. Adult females of both species strongly preferred to feed on D. wrightii rather than on N. attenuata leaves, but T. mucorea preferred to oviposit on N. attenuata, while T. compacta oviposited only on D. wrightii. These oviposition behaviours increased offspring performance: T. compacta larvae only survived in D. wrightii stems and T. mucorea larvae survived better in N. attenuata than in D. wrightii stems. Choice assays with nicotine-free, JA-impaired, and sesquiterpene-over-produced isogenic N. attenuata plants revealed that although half of the T. compacta larvae survived in nicotine-free N. attenuata lines, nicotine did not influence the oviposition behaviours of both the nicotine-adapted and nicotine-sensitive species. JA-induced sesquiterpene volatiles are key compounds influencing T. mucorea females' oviposition choices, but these sesquiterpenes had no effect on larval performance. We conclude that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions. © 2016 John Wiley & Sons Ltd.

  6. Socioeconomic status affects mosquito (Diptera: Culicidae) larval habitat type availability and infestation level.

    Science.gov (United States)

    Dowling, Zara; Ladeau, Shannon L; Armbruster, Peter; Biehler, Dawn; Leisnham, Paul T

    2013-07-01

    Mosquito populations are largely regulated by processes occurring at the larval stage. We sampled mosquito larval microhabitats (mostly water-holding containers) in six neighborhoods in the Washington, DC, area that varied in socioeconomic status (SES) and housing structure (row houses vs. stand-alone houses) to test associations among these neighborhood characteristics, microhabitat abundance and parameters, and mosquito occurrence and densities. Thirty-four percent (33.9%) of sampled microhabitats contained mosquito larvae, and 93.1% of larvae were Aedes albopictus Skuse or Culex pipiens L. Five specific container types (drains, corrugated flexible drainpipes, planters, garbage cans, and buckets) accounted for the majority of water-holding (56.0%) and mosquito-positive (50.6%) microhabitats sampled. We found no associations between SES or housing structure with total microhabitat abundance per yard, mosquito occurrence or mosquito densities per microhabitat. In contrast, container purpose varied with SES, with low SES neighborhoods having greater numbers of disused containers and lower numbers of functional containers than low and medium SES neighborhoods. Ae. albopictus were 83% more abundant in disused containers, whereas Cx. pipiens were more abundant in structural and functional containers, possibly owing to species-specific oviposition and development related to water quality. Ae. albopictus densities increased over the summer, whereas Cx. pipiens densities remained constant. Ae. albopictus is usually the dominant pest in urban areas in the eastern United States; therefore, integrated mosquito management programs should incorporate the elimination of disused containers to reduce its infestation and adult production, especially in low SES neighborhoods where they occur most frequently.

  7. Larval Habitat Substrates Could Affect the Biology and Vectorial Capacity of Culex quinquefasciatus (Diptera: Culicidae).

    Science.gov (United States)

    Shah, Rizwan Mustafa; Ali, Qasim; Alam, Mehboob; Shad, Sarfraz Ali; Majeed, Shahid; Riaz, Muhammad; Binyameen, Muhammad

    2017-05-01

    Culex quinquefasciatus Say is an important disease vector throughout much of the world. Experiments were conducted to determine the effects of different larval habitat substrates on the fitness and biting efficiency of Cx. quinquefasciatus adults. Our findings indicate that the development time (egg to adult) of larvae reared in irrigation water was 8.63 d while that of larvae reared in distilled water was 17.10 d (Effect size = 0.95). However, the rate of adult emergence was similar for all the tested treatments. Furthermore, the mean weight of an egg raft varied between larval habitats: distilled water (1.83 mg), rainfall water (1.25 mg), irrigation water (1.52 mg), and sewerage water (2.52 mg) (Effect size = 0.91). But, the fecundity (eggs per female) and hatchability (%) were statistically similar in all the rearing mediums (Effect size = 0.79). Longevity of females in all the tested populations did not differ significantly (Effect size = 0.91). The mean relative growth rates of larvae reared in tap water (0.80) and distilled water (0.86) habitats were lower than growth rates in all other rearing habitats (Effect size = 0.96). The intrinsic rate of natural increase in tap water (0.27) and irrigation water (0.35) was significantly higher than that in distilled water (0.09) and sewerage water (0.16) (Effect size = 0.84). Adults reared in rain water had the highest biting efficiency among all the tested populations. These results provide useful information for the management of Cx. quinquefasciatus. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Larval exposure to chlorpyrifos affects nutritional physiology and induces genotoxicity in silkworm Philosamia ricini (Lepidoptera: Saturnidae

    Directory of Open Access Journals (Sweden)

    Moni Kankana Kalita

    2016-11-01

    Full Text Available Chlorpyrifos is a most widely used organophosphate insecticide because of its cost effectiveness and degradable nature. However, this pesticide enters and contaminates the environment either by direct application, spray drifts or crop run off and shows adverse effect on the non-targeted organisms. Philosamia ricini (eri silkworm, one of the most exploited, domesticated and commercialized non mulberry silkworm is known for mass production of eri silk. The silkworm larvae get exposed to pesticide residues on the leaves of food plants. The present study investigates the effect of commercial formulation of chlorpyrifos (Pyrifos-20 EC on eri silkworm. Initially the LC50 value of chlorpyrifos was determined at 24 - 96 h and further experiments were carried out with sub lethal concentrations of the chlorpyrifos after 24 h of exposure period. The potential toxicity of chlorpyrifos was evaluated as a fuction of metabolism and nutritional physiology in 3rd, 4th and 5th instar larvae. Alteration in histoarchitecture of 5th instar eri silkworm gut exposed to sub lethal concentration of chlorpyrifos formulation was also studied. Chlorpyrifos induced genotoxicity in silkworm hemocytes was also investigated by single cell gel electrophoresis, micronuclei assay and apoptosis assay. Herein, LC50 values of chlorpyrifos were calculated as 3.83, 3.35, 2.68 and 2.35 mg/L at 24 h, 48 h, 72 h and 96 h respectively. A significant decrease in trehalose activity along with digestive enzyme activity was observed in chlorpyrifos affected groups (P < 0.05. Further, genotoxicity study revealed higher tail percentage, tail length and tail moment of the damage DNA in chlorpyrifos exposed groups (P < 0.001. Moreover, at 2.0 mg/L concentration, ~ 10 fold increases in tail length was observed as compared to the control. Results showed activation of caspase activity following 24 hr chlorpyrifos exposure (1.5 mg/L and 2.0 mg/L in a dose-dependent manner. Moreover, in control group

  9. Affective and cognitive drivers of food choice

    NARCIS (Netherlands)

    Gutjar, S.

    2015-01-01

    Abstract  Introduction In sensory science liking ratings are commonly used to understand and predict food intake and choice. And indeed, higher liked products are more often chosen than lower liked products. However, there is more to food

  10. Affective and cognitive drivers of food choice

    NARCIS (Netherlands)

    Gutjar, S.

    2015-01-01

    Abstract  Introduction In sensory science liking ratings are commonly used to understand and predict food intake and choice. And indeed, higher liked products are more often chosen than lower liked products. However, there is more to food choic

  11. Larval development and metamorphosis of Balanus albicostatus (Cirripedia: Thoracica); implications of temperature, food concentration and energetics

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, D.V.; Khandeparker, L.; Shirayama, Y.

    The influence of food concentrations (0.5, 1 and 2 x 105 cells ml sup(-1)) and temperatures (20 and 30 degrees C) on the survival, development, organic carbon and nitrogen content of Balanus albicostatus larvae was evaluated The effect of food...

  12. Food neophobia in childhood affects dietary variety.

    Science.gov (United States)

    Falciglia, G A; Couch, S C; Gribble, L S; Pabst, S M; Frank, R

    2000-12-01

    To determine whether children with food neophobia (unwillingness to try new foods) have more restrictive diets than children without neophobia. Seventy children were classified into 3 groups based on scores obtained on the Food Neophobia Scale: neophobic group, score greater than 41; neophilic group, score less than 27; and average group, score of 28 to 40. Dietary data were collected and analyzed for 3 days selected randomly. The dependent variables measured were energy and nutrient intakes, servings of each Food Guide Pyramid group, and Health Eating Index (HEI) scores. chi 2, 1-way analysis of covariance, and Scheffé multiple comparisons tests were conducted. The 3 groups were similar with respect to the number of children meeting two thirds of the RDA/DRI for energy and most nutrients. The exception was vitamin E: fewer neophobic children met two thirds of the recommended value for this nutrient than average and neophilic children. The overall HEI score was significantly lower for the neophobic group compared with the average and neophilic groups. The HEI index showed that children with neophobia had a higher intake of saturated fat and less food variety than children without food neophobia. Dietitians should emphasize increased food variety for children within the context of a healthful diet. Research should be conducted to determine the effects of dietary variety on quality of diet and health of children.

  13. Conventional and organic soil fertility management practices affect corn plant nutrition and Ostrinia nubilalis (Lepidoptera: Crambidae) larval performance.

    Science.gov (United States)

    Murrell, Ebony G; Cullen, Eileen M

    2014-10-01

    Few studies compare how different soil fertilization practices affect plant mineral content and insect performance in organic systems. This study examined: 1) The European corn borer, Ostrinia nubilalis (Hübner), larval response on corn (Zea mays L.) grown in field soils with different soil management histories; and 2) resilience of these plants to O. nubilalis herbivory. Treatments included: 1) standard organic--organically managed soil fertilized with dairy manure and 2 yr of alfalfa (Medicago sativa L.) in the rotation; 2) basic cation saturation ratio--organically managed soil fertilized with dairy manure and alfalfa nitrogen credits, plus addition of gypsum (CaSO4·2H2O) according to the soil balance hypothesis; and 3) conventional--conventionally managed soil fertilized with synthetic fertilizers. Corn plants were reared to maturity in a greenhouse, and then infested with 0-40 O. nubilalis larvae for 17 d. O. nubilalis exhibited negative competitive response to increasing larval densities. Mean development time was significantly faster for larvae consuming basic cation saturation ratio plants than those on standard organic plants, with intermediate development time on conventional plants. Neither total yield (number of kernels) nor proportion kernels damaged differed among soil fertility treatments. Soil nutrients differed significantly in S and in Ca:Mg and Ca:K ratios, but principal components analysis of plant tissue samples taken before O. nubilalis infestation showed that S, Fe, and Cu contributed most to differences in plant nutrient profiles among soil fertility treatments. Results demonstrate that different fertilization regimens can significantly affect insect performance within the context of organic systems, but the effects in this study were relatively minor compared with effects of intraspecific competition.

  14. Food and predators affect egg production in song sparrows.

    Science.gov (United States)

    Zanette, Liana; Clinchy, Michael; Smith, James N M

    2006-10-01

    Although the possibility that food and predators may interact in limiting avian populations has long been recognized, there have been few attempts to test this experimentally in the field. We conducted a manipulative food addition experiment on the demography of Song Sparrows (Melospiza melodia) across sites that varied in predator abundance, near Victoria, British Columbia, Canada, over three consecutive breeding seasons. We previously showed that food and predators had interactive effects on annual reproductive success (young fledged per female). Here, we report the effects on egg production. Our results show that food limits the total number of eggs laid over the breeding season ("total egg production") and that interactive food and predator effects, including food effects on nest predation, determine how those eggs are "parceled out" into different nests. Food addition alone significantly affected total egg production, and there was no significant interannual variability in this result. At the same time, both food and predators affected the two determinants of total egg production: "clutch number" (total number of clutches laid) and average clutch size. Both clutch number and size were affected by a food x predator x year interaction. Clutch number was lower at low-predator locations because there was less nest predation and thus less renesting. Food addition also significantly reduced nest predation, but there was significant interannual variation in this effect. This interannual variation was responsible for the food x predator x year interactions because the larger the effect of food on nest predation in a given year, the smaller was the effect of food on clutch number; and the smaller the effect of food on clutch number, the larger was the effect of food on clutch size. Potential predator and year effects on total egg production were thus cancelled out by an inverse relationship between clutch number and clutch size. We suggest that combined food and

  15. Larval life history responses to food deprivation in three species of predatory lady beetles (Coleoptera: Coccinellidae)

    Science.gov (United States)

    We studied life history responses of larvae of three coccinellid species, Coleomegilla maculata (DeGeer), Hippodamia convergens Guerin-Meneville, and Harmonia axyridis (Pallas), when deprived of food for different periods of time during the fourth stadium. The coccinellid species did not differ in ...

  16. Maternal presence and environmental enrichment affect food neophobia of piglets.

    Science.gov (United States)

    Oostindjer, Marije; Muñoz, Julia Mas; Van den Brand, Henry; Kemp, Bas; Bolhuis, J Elizabeth

    2011-02-23

    Young omnivores show food neophobia in order to avoid the potential harmful effects of ingesting unfamiliar food items. We investigated whether the presence of the mother and an enriched rearing environment would reduce food neophobia in piglets. A mother may provide information on suitable food types to include in the diet, whereas an enriched environment may stimulate behavioural development and reduce reactivity towards novel stimuli (including food). Five barren-reared or enriched-reared piglets per litter were exposed to two novel food items in the presence, and the other five per litter in the absence, of the mother in a 7 min test. Maternal presence reduced food neophobia profoundly as reflected in a reduced latency to touching the food, a higher proportion of piglets sampling the two different food items and a higher intake. Latency to touch the food, however, was affected by maternal presence more strongly for barren-reared piglets than for enriched-reared piglets, and in the absence of the sow, consumption of one novel food type and time spent in the feeding area were higher for enriched-reared piglets. Environmental enrichment does have the potential to reduce food neophobia, but the presence of the mother during the encounter with novel food seems more efficient in decreasing food neophobia of piglets.

  17. Dietary salt levels affect salt preference and learning in larval Drosophila.

    Directory of Open Access Journals (Sweden)

    Cheryl Russell

    Full Text Available Drosophila larvae change from exhibiting attraction to aversion as the concentration of salt in a substrate is increased. However, some aversive concentrations appear to act as positive reinforcers, increasing attraction to an odour with which they have been paired. We test whether this surprising dissociation between the unconditioned and conditioned response depends on the larvae's experience of salt concentration in their food. We find that although the point at which a NaCl concentration becomes aversive shifts with different rearing experience, the dissociation remains evident. Testing larvae using a substrate 0.025 M above the NaCl concentration on which the larvae were reared consistently results in aversive choice behaviour but appetitive reinforcement effects.

  18. Variation in food availability mediate the impact of density on cannibalism, growth, and survival in larval yellow spotted mountain newts (Neurergus microspilotus): Implications for captive breeding programs.

    Science.gov (United States)

    Vaissi, Somaye; Sharifi, Mozafar

    2016-11-01

    In this study, we examined cannibalistic behavior, growth, metamorphosis, and survival in larval and post-metamorph endangered yellow spotted mountain newts Neurergus microspilotus hatched and reared in a captive breeding facility. We designed a 2 × 2 factorial experiment, crossing two levels of food with two levels of density including high food/high density, high food/low density, low food/high density, and low food/low density. The level of cannibalistic behavior (including the loss of fore and hind limbs, missing toes, tail, gills, body damage, and whole body consumption) changed as the larvae grew, from a low level during the first 4 weeks, peaking from weeks 7 to 12, and then dropped during weeks 14-52. Both food level and density had a significant effect on cannibalism. The highest frequency of cannibalism was recorded for larvae reared in the low food/high density and lowest in high food/low density treatments. Growth, percent of larval metamorphosed, and survival were all highest in the high food/low density and lowest in low food/high density treatment. Food level had a significant effect on growth, metamorphosis, and survival. However, the two levels of density did not influence growth and metamorphosis but showed a significant effect on survival. Similarly, combined effects of food level and density showed significant effects on growth, metamorphosis, and survival over time. Information obtained from current experiment could improve productivity of captive breeding facilities to ensure the release of adequate numbers of individuals for reintroduction programs. Zoo Biol. 35:513-521, 2016. © 2016 The Authors. Zoo Biology published by Wiley Periodicals, Inc. © 2016 The Authors. Zoo Biology published by Wiley Periodicals, Inc.

  19. Copepod recruitment and food composition : Do diatoms affect hatching success?

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Kiørboe, Thomas

    1996-01-01

    was fed several different diets while egg production and hatching success were monitored. The diet was analysed for fatty acid content as an indicator of food quality. Both egg production and hatching were found to be affected by the nutritional quality of the food. Hatching was also highly dependent...

  20. Cardenolide connection between overwintering monarch butterflies from Mexico and their larval food plant,Asclepias syriaca.

    Science.gov (United States)

    Seiber, J N; Brower, L P; Lee, S M; McChesney, M M; Cheung, H T; Nelson, C J; Watson, T R

    1986-05-01

    The majority (85%) of 394 monarch butterflies sampled from overwintering sites in Mexico contain the same epoxy cardenolide glycosides, including most conspicuously a novel polar glycoside with a single genin-sugar bridge (aspecioside), as occur in the milkweedsAsclepias speciosa andA. syriaca. This cardenolide commonality was established by isolating aspecioside and syriobioside from the wings of overwintering monarchs and the two plant species, and comparing Chromatographie and NMR spectrometric characteristics of the isolates. When combined with the migratory pattern of monarchs and the distribution of these two milkweed species, this chemical evidence lends strong support to the hypothesis thatA. syriaca is the major late summer food plant of monarchs in eastern North America. This finding may be of ecological importance, forA. syriaca contributes less cardenolide and cardenolides of lower emetic potency to monarchs than most milkweeds studied to date.

  1. Bacterial formyl peptides affect the innate cellular antimicrobial responses of larval Galleria mellonella (Insecta: Lepidoptera).

    Science.gov (United States)

    Alavo, Thiery B C; Dunphy, Gary B

    2004-04-01

    The non-self cellular (hemocytic) responses of Galleria mellonella larvae, including the attachment to slides and the removal of the bacteria Xenorhabdus nematophila and Bacillus subtilis from the hemolymph, were affected by N-formyl peptides. Both N-formyl methionyl-leucyl-phenylalanine (fMLF) and the ester derivative decreased hemocyte adhesion in vitro, and both elevated hemocyte counts and suppressed the removal of both X. nematophila and B. subtilis from the hemolymph in vivo. The amide derivative and the antagonist tertiary-butoxy-carbonyl-methionyl-leucyl-phenylalanine (tBOC) increased hemocyte attachment to glass. The fMLF suppressed protein discharge from monolayers of granular cells with and without bacterial stimulation, while tBOC stimulated protein discharge. The peptide tBOC offset the effects of fMLF in vitro and in vivo. This is the first report implying the existence of formyl peptide receptors on insect hemocytes in which the compounds fMLF and tBOC inhibited and activated hemocyte activity, respectively.

  2. Copepod recruitment and food composition : Do diatoms affect hatching success?

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Kiørboe, Thomas

    1996-01-01

    Laboratory experiments were conducted to differentiate between factors controlling the hatching success of copepod eggs. Factors that could affect viability of eggs; viz food quality, female condition and external factors were investigated. In a series of experiments the copepod Acartia tonsa Dana...... was fed several different diets while egg production and hatching success were monitored. The diet was analysed for fatty acid content as an indicator of food quality. Both egg production and hatching were found to be affected by the nutritional quality of the food. Hatching was also highly dependent...

  3. Factors Affecting Food Away from Home: Are Food-Secure and Food-Insecure Households Different?

    OpenAIRE

    Pan, Suwen; Jensen, Helen H.; Malaga, Jaime E.

    2007-01-01

    Expenditures on food away from home by food-secure and food-insecure households are compared. The analysis, based on data from the Current Population Survey (CPS), finds that female labor force participation, household income, Food Stamp Program (FSP) participation, education, and other socio-demographic variables have different effects on the food expenditures made by households classified as food-secure in comparison to food-insecure households.

  4. Factors Affecting Food Safety of Animal Origin in Indonesia

    Directory of Open Access Journals (Sweden)

    Sjamsul Bahri

    2006-03-01

    Full Text Available Based on the Indonesian Regulation Number 7 year 1996, food is defined as everything derived from biological sources and water, either processed and non-processed materials to be used as food and drinks, including food additives, food raw materials and other materials for preparation process, processing and production of food or drinks . Furthermore, food safety is a condition and an approach required to prevent the food from contamination of pathogenic microbes, toxic compounds and other xenobiotics that may affect and hazardous to human health . Food safety is basically a complexity and close related to policy . toxicity, microbiology, chemicals, nutrition status, health and public welfare . On the other hand, food safety problem is a dynamic process following the changing of public society including socioculture, health, development of science and technology as well as everything related to human life . In general, there are three main stages of process as the critical point in food safety of animal origin, namely : (1 preharvest ; (2 production ; and (3 postharvest . The main factors of these stages are discussed in this paper .

  5. Technological factors affecting biogenic amine content in foods: a review

    Directory of Open Access Journals (Sweden)

    Fausto Gardini

    2016-08-01

    Full Text Available Biogenic amines (BAs are molecules which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine and agmatine. The importance of preventing the excessive accumulation of BAs in food is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BA accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting biogenic amine content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity and other BAs, environmental factors influencing BA formation (temperature, salt concentration, pH. In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolising BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances are addressed.

  6. Technological Factors Affecting Biogenic Amine Content in Foods: A Review

    Science.gov (United States)

    Gardini, Fausto; Özogul, Yesim; Suzzi, Giovanna; Tabanelli, Giulia; Özogul, Fatih

    2016-01-01

    Biogenic amines (BAs) are molecules, which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine, and agmatine. The importance of preventing the excessive accumulation of BAs in foods is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BAs accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting BA content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity, and other BAs), environmental factors influencing BA formation (temperature, salt concentration, and pH). In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolizing BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances) are addressed. PMID:27570519

  7. Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate

    Indian Academy of Sciences (India)

    MANASWINI SARANGI; ARCHANA NAGARAJAN; SNIGDHADIP DEY; JOY BOSE; AMITABH JOSHI

    2016-09-01

    Multiple experimental evolution studies on Drosophila melanogasterin the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies. We recently showed that populations of D. ananassaeand D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through acombination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very differentsuite of traits than that seen to evolve under similar selection in D. melanogasterand was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates ofgreater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term labora-tory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we

  8. Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate.

    Science.gov (United States)

    Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh

    2016-09-01

    Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we

  9. GROWTH AND BEHAVIOR OF LARVAL ZEBRAFISH Danio rerio FED A PROCESSED DIET, LIVE FOOD, OR THE COMBINATION

    Science.gov (United States)

    Because Zebrafish (Danio rerio) have become a popular and important model for scientific research, the capability to rear larval zebrafish to adulthood is of great importance. Recently research examining the effects of diet (live versus processed) have been published. In the cu...

  10. Immature stages and the larval food plant of Nacaduba pactolus ceylonica Fruhstorfer, 1916 (Lepidoptera: Lycaenidae in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Tharaka Sudesh Priyadarshana

    2015-10-01

    Full Text Available The biology of  Nacaduba pactolus ceylonica (Large Four-lineblue , a rare butterfly endemic to Sri Lanka is described with a report of Entada rheedii (Fabaceae as the first known larval host plant. Information pertaining to the distribution of this butterfly is also provided.

  11. Foliage maturity of Quercus ilex affects the larval development of a Croatian coastal population of Lymantria dispar (Lepidoptera: Erebidae

    Directory of Open Access Journals (Sweden)

    Lukić Ivan

    2017-02-01

    Full Text Available Gypsy moth (Lymantria dispar is one of the most important forest pests in the world. Numerous previous studies focused only on different host tree species, but small number of them on foliage age. Since recent genetic analyses showed that there are significant differences between Croatian continental and coastal population we investigated coastal population since there was no previous research. For this research juvenile and mature foliage of Holm oak (Quercus ilex was used. Larval development was investigated in two laboratory experiments. One experiment involved rearing trials consisting of 50 individual larvae per treatment while a parallel experiment investigated gregarious feeding conditions using 120 larvae in a rearing treatment. Larval mortality was lower and development time shorter for individuals reared on juvenile foliage. High pupation success in both the individual and group rearing experiment for larvae reared on juvenile foliage was also observed. To conclude, our results showed high mortality, poor larval development and low pupation success in larvae reared on mature foliage. This research is significant because in the aspect of ongoing climate changes there is a possibility that gypsy moth will move to the north and shift its distribution by expanding into new climatic area.

  12. How 21st century droughts affect food and environmental security

    Science.gov (United States)

    Kogan, Felix

    The first 13th years of the 21st century has begun with a series of widespread, long and intensive droughts around the world. Extreme and severe-to-extreme intensity droughts covered 2-6% and 7-16% of the world land, respectively, affecting environment, economies and humans. These droughts reduced agricultural production, leading to food shortages, human health deterioration, poverty, regional disturbances, population migration and death. This presentation is a travelogue of the 21st century global and regional droughts during the warmest years of the past 100 years. These droughts were identified and monitored with the NOAA operational space technology, called Vegetation Health (VH), which has the longest period of observation and provide good data quality. The VH method was used for assessment of vegetation condition or health, including drought early detection and monitoring. The VH method is based on operational satellites data estimating both land surface greenness (NDVI) and thermal conditions. The 21st century droughts in the USA, Russia, Australia Argentina, Brazil, China, India and other principal grain producing countries were intensive, long, covered large areas and caused huge losses in agricultural production, which affected food and environmental security and led to food riots in some countries. This presentation investigate how droughts affect food and environmental security, if they can be detected earlier, how to monitor their area, intensity, duration and impacts and also their dynamics during the climate warming era with satellite-based vegetation health technology.

  13. Nitric oxide affects ERK signaling through down-regulation of MAP kinase phosphatase levels during larval development of the ascidian Ciona intestinalis.

    Directory of Open Access Journals (Sweden)

    Immacolata Castellano

    Full Text Available In the ascidian Ciona intestinalis larval development and metamorphosis require a complex interplay of events, including nitric oxide (NO production, MAP kinases (ERK, JNK and caspase-3 activation. We have previously shown that NO levels affect the rate of metamorphosis, regulate caspase activity and promote an oxidative stress pathway, resulting in protein nitration. Here, we report that NO down-regulates MAP kinase phosphatases (mkps expression affecting positively ERK signaling. By pharmacological approach, we observed that the reduction of endogenous NO levels caused a decrease of ERK phosphorylation, whereas increasing levels of NO induced ERK activation. We have also identified the ERK gene network affected by NO, including mpk1, mpk3 and some key developmental genes by quantitative gene expression analysis. We demonstrate that NO induces an ERK-independent down-regulation of mkp1 and mkp3, responsible for maintaining the ERK phosphorylation levels necessary for transcription of key metamorphic genes, such as the hormone receptor rev-erb and the van willebrand protein vwa1c. These results add new insights into the role played by NO during larval development and metamorphosis in Ciona, highlighting the cross-talk between different signaling pathways.

  14. Foods and food constituents that affect the brain and human behavior

    Science.gov (United States)

    Lieberman, Harris R.; Wurtman, Richard J.

    1986-01-01

    Until recently, it was generally believed that brain function was usually independent of day-to-day metabolic changes associated with consumption of food. Although it was acknowledged that peripheral metabolic changes associated with hunger or satiety might affect brain function, other effects of foods on the brain were considered unlikely. However, in 1971, Fernstrom and Wurtman discovered that under certain conditions, the protein-to-carbohydrate ratio of a meal could affect the concentration of a particular brain neurotransmitter. That neurotransmitter, serotonin, participates in the regulation of a variety of central nervous system (CNS) functions including sleep, pain sensitivity, aggression, and patterns of nutrient selection. The activity of other neurotransmitter systems has also been shown to be, under certain conditions, affected by dietary constituents which are given either as ordinary foods or in purified form. For example, the CNS turnover of two catecholamine neurotransmitters, dopamine and norepinephrine, can be altered by ingestion of their amino acid precursor, tyrosine, when neurons that release these monoamines are firing frequently. Similarly, lecithin, a dietary source of choline, and choline itself have been shown to increase the synthesis of acetylcholine when cholinergic neurons are very active. It is possible that other neurotransmitters could also be affected by precursor availability or other, as yet undiscovered peripheral factors governed by food consumption. The effects of food on neurotransmitters and behavior are discussed.

  15. Changes in a middle school food environment affect food behavior and food choices.

    Science.gov (United States)

    Wordell, Doug; Daratha, Kenn; Mandal, Bidisha; Bindler, Ruth; Butkus, Sue Nicholson

    2012-01-01

    Increasing rates of obesity among children ages 12 to 19 years have led to recommendations to alter the school food environment. The purpose of this study was to determine whether there are associations between an altered school food environment and food choices of middle school students both in and outside of school. In a midsized western city, two of six middle schools allowed only bottled water in vending machines, only milk and fruit on à la carte menus, and offered a seasonal fruit and vegetable bar. Three years after the intervention was initiated, seventh- and eighth-grade students attending the two intervention schools and four control middle schools were surveyed about their food choices. A total of 2,292 surveys were completed. Self-reported frequency of consumption for nine food groups in the survey was low; consumption was higher outside than in school. Boys consumed more milk than girls although girls consumed more fruits and vegetables. Significant socioeconomic differences existed. Compared with students who paid the full lunch fee, students qualifying for free and reduced-price meals consumed more milk and juice in schools but less outside school; more candy and energy drinks in school; and more sweet drinks, candy, pastries, and energy drinks outside school. Students in intervention schools were 24% more likely to consume milk outside school, 27% less likely to consume juice in school, and 56% less likely to consume sweet pastries in school. There were no differences in fruit and vegetable consumption reported by children in control and intervention schools. Overall, there was a positive association between a modified school food environment and student food behavior in and outside school. Policies related to the school food environment are an important strategy to address the obesity epidemic in our country. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  16. Tree holes as larval habitats for Aedes aegypti in urban, suburban and forest habitats in a dengue affected area.

    Science.gov (United States)

    Mangudo, C; Aparicio, J P; Gleiser, R M

    2015-12-01

    Aedes aegypti (L.) (Diptera: Culicidae), the main vector of dengue and urban yellow fever in the world, is highly adapted to the human environment. Artificial containers are the most common larval habitat for the species, but it may develop in tree holes and other phytotelmata. This study assessed whether tree holes in San Ramón de la Nueva Orán, a city located in subtropical montane moist forest where dengue outbreaks occur, are relevant as larval habitat for Ae. aegypti and if the species may be found in natural areas far from human habitations. Water holding tree holes were sampled during 3 years once a month along the rainy season using a siphon bottle, in urban and suburban sites within the city and in adjacent forested areas. Larvae and pupae were collected and the presence and volume of water in each tree hole were recorded. Finding Ae. aegypti in forested areas was an isolated event; however, the species was frequently collected from tree holes throughout the city and along the sampling period. Moreover, larvae were collected in considerably high numbers, stressing the importance of taking into account these natural cavities as potential reinfestation foci within dengue control framework.

  17. Does skipping a meal matter to a butterfly's appearance? Effects of larval food stress on wing morphology and color in monarch butterflies.

    Directory of Open Access Journals (Sweden)

    Haley Johnson

    Full Text Available In animals with complex life cycles, all resources needed to form adult tissues are procured at the larval stage. For butterflies, the proper development of wings involves synthesizing tissue during metamorphosis based on the raw materials obtained by larvae. Similarly, manufacture of pigment for wing scales also requires resources acquired by larvae. We conducted an experiment to test the effects of food deprivation in the larval stage on multiple measures of adult wing morphology and coloration of monarch butterflies (Danaus plexippus, a species in which long-distance migration makes flight efficiency critical. In a captive setting, we restricted food (milkweed from late-stage larvae for either 24 hrs or 48 hrs, then after metamorphosis we used image analysis methods to measure forewing surface area and elongation (length/width, which are both important for migration. We also measured the brightness of orange pigment and the intensity of black on the wing. There were correlations between several wing features, including an unexpected association between wing elongation and melanism, which will require further study to fully understand. The clearest effect of food restriction was a reduction in adult wing size in the high stress group (by approximately 2%. Patterns observed for other wing traits were ambiguous: monarchs in the low stress group (but not the high had less elongated and paler orange pigmentation. There was no effect on wing melanism. Although some patterns obtained in this study were unclear, our results concerning wing size have direct bearing on the monarch migration. We show that if milkweed is limited for monarch larvae, their wings become stunted, which could ultimately result in lower migration success.

  18. Does Skipping a Meal Matter to a Butterfly's Appearance? Effects of Larval Food Stress on Wing Morphology and Color in Monarch Butterflies

    Science.gov (United States)

    Johnson, Haley; Solensky, Michelle J.; Satterfield, Dara A.; Davis, Andrew K.

    2014-01-01

    In animals with complex life cycles, all resources needed to form adult tissues are procured at the larval stage. For butterflies, the proper development of wings involves synthesizing tissue during metamorphosis based on the raw materials obtained by larvae. Similarly, manufacture of pigment for wing scales also requires resources acquired by larvae. We conducted an experiment to test the effects of food deprivation in the larval stage on multiple measures of adult wing morphology and coloration of monarch butterflies (Danaus plexippus), a species in which long-distance migration makes flight efficiency critical. In a captive setting, we restricted food (milkweed) from late-stage larvae for either 24 hrs or 48 hrs, then after metamorphosis we used image analysis methods to measure forewing surface area and elongation (length/width), which are both important for migration. We also measured the brightness of orange pigment and the intensity of black on the wing. There were correlations between several wing features, including an unexpected association between wing elongation and melanism, which will require further study to fully understand. The clearest effect of food restriction was a reduction in adult wing size in the high stress group (by approximately 2%). Patterns observed for other wing traits were ambiguous: monarchs in the low stress group (but not the high) had less elongated and paler orange pigmentation. There was no effect on wing melanism. Although some patterns obtained in this study were unclear, our results concerning wing size have direct bearing on the monarch migration. We show that if milkweed is limited for monarch larvae, their wings become stunted, which could ultimately result in lower migration success. PMID:24695643

  19. Zebra mussels (Dreissena polymorpha) limit food for larval fish (Pimephales promelas) in turbulent systems: A bioenergetics analysis

    Science.gov (United States)

    Bartsch, L.A.; Richardson, W.B.; Sandheinrich, M.B.

    2003-01-01

    We conducted a factorial experiment, in outdoor mesocosms, on the effects of zebra mussels and water column mixing (i.e., turbulence) on the diet, growth, and survival of larval fathead minnows (Pimephales promelas). Significant (P zebra mussels, whereas mortality was 37% in treatment with turbulence and 17% and 18% in the zebra mussels treatment, and the control, respectively. The size of individual fish was significantly different among treatments at the end of the experiment and was inversely related to survival. Levels of trophic resources (i.e., phyto and zooplankton) varied among treatments and were treatment specific. Turbulent mixing facilitated removal of phytoplankton by zebra mussels by making the entire water column of the tanks available to these benthic filter feeders. Early in the experiment (Day = 0 to 14) the physical process of turbulent mixing likely caused a reduction in standing stocks of zooplankton. The interactive effect of turbulence and mussels reduced copepod and rotifer stocks, through physical processes and through filtration by zebra mussels, relative to the turbulence treatment. The reductions in the number of total zooplankton in the turbulent mixing mesocosms and the further reduction of rotifer and copepod in the turbulence and mussels treatment coincided with a period of increased reliance of larval fathead minnows on these prey. Estimates of consumption from bioenergetics modeling and measured prey standing stocks indicated caloric resources of suitable prey in turbulence treatments during the early weeks of the experiment were insufficient to prevent starvation. Early mortality in the turbulence and mussels treatment likely released surviving fish from intense intraspecific competition and resulted in higher individual growth rates. A combination of high abundance of zebra mussels in an environment with a well-mixed water column can have significant effects on larval fish survival and growth.

  20. Larval development and metamorphosis in Balanus amphitrite Darwin (Cirripedia; Thoracica): Significance of food concentration, temperature and nucleic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Anil, A.C.; Desai, D.V.; Khandeparker, L.

    an individual’s chance of locating a site appropriate for metamorphosis, but simultane- ously reducing the ability to compete for space during the first few weeks of juvenile life. The cypris larvae are non-feeding and have to depend upon the energy reserves... barnacles to compete for space and seriously reduce their likelihood of successfully recruiting to the adult population. In Ž. Ž. the light of these observations, Jarrett and Pechenik 1997 and Pechenik et al. 1998 opined that larval experience influences...

  1. Factors Affecting Rural Households’ Resilience to Food Insecurity in Niger

    Directory of Open Access Journals (Sweden)

    Aboubakr Gambo Boukary

    2016-03-01

    Full Text Available Niger faces many natural and human constraints explaining the erratic evolution of its agricultural production over time. Unfortunately, this is likely to cause a decline in the food supply. This study attempts to identify factors affecting rural households’ resilience to food insecurity in Niger. For this, we first create a resilience index by using principal component analysis and later apply structural equation modeling to identify its determinants. Data from the 2010 National Survey on Households’ Vulnerability to Food Insecurity done by the National Institute of Statistics is used. The study shows that asset and social safety net indicators are significant and have a positive impact on households’ resilience. Climate change approximated by long-term mean rainfall has a negative and significant effect on households’ resilience. Therefore, to strengthen households’ resilience to food insecurity, there is a need to increase assistance to households through social safety nets and to help them gather more resources in order to acquire more assets. Furthermore, early warning of climatic events could alert households, especially farmers, to be prepared and avoid important losses that they experience anytime an uneven climatic event occurs.

  2. Larval development of japanese "conchostracans"

    DEFF Research Database (Denmark)

    Olesen, Jorgen; Fritsch, Martin; Grygier, Mark J.

    2013-01-01

    For comparison with the remarkable larvae of the laevicaudatan (clam shrimp) Lynceus brachyurus, a basic description of the larval sequence of another laevicaudatan branchiopod, the Japanese Lynceus biformis, is provided. Four larval stages have been identified, ranging in size from 258 to 560 mu m...... to the endopod and a change in the form of the naupliar process, used for food manipulation, from a long, unbranched, pointed spine to a bifid structure. In addition, buds of trunk limbs (five pairs) first appear externally in stage 4 but can be recognized through the cuticle in the previous stage. The larval...

  3. Sweet potato resistance to Euscepes postfasciatus (Coleoptera: Curculionidae): larval performance adversely effected by adult's preference to tuber for food and oviposition.

    Science.gov (United States)

    Okada, Y; Yasuda, K; Sakai, T; Ichinose, K

    2014-08-01

    The preferences of the West Indian sweet potato weevil, Euscepes postfasciatus (Fairmaire), to tubers of sweet potato, Ipomoea batatas (L.), for food and for oviposition were evaluated, and correlated to sweet potato's resistance to immatures. Adults (parent) were released in a plastic box containing tubers of sweet potato cultivars and maintained for 5 d, after which the adults on each tuber were counted. All adults were then removed and each tuber was maintained separately. New adults that emerged from the tubers were counted. Cultivars were grouped by cluster analyses using the number of parent adults on the tubers and the number of new adults emerging from the tubers, adjusted for the weight of each tuber. Cultivars were divided into five groups: average level of preference, preferred, preferred for oviposition but not for food, preferred for food but not for oviposition, and not preferred. New adults from the first two groups took less time to eclose than those from the other groups, and their body size was smaller. In a second experiment, one to five cultivars were selected from each group and inoculated each tuber with 10 weevil eggs on each cultivar. Although the proportion of eclosed adults was not significantly different between cultivars, the time to eclosion was shorter and body size was smaller on preferred cultivars. The selection of tubers by parent adults was not linearly related with larval development, and did not reduce the survival of the immatures.

  4. RNA interference of a putative S-adenosyl-L-homocysteine hydrolase gene affects larval performance in Leptinotarsa decemlineata (Say).

    Science.gov (United States)

    Zhou, Li-Tao; Jia, Shuang; Wan, Pin-Jun; Kong, Ye; Guo, Wen-Chao; Ahmat, Tursun; Li, Guo-Qing

    2013-10-01

    In Leptinotarsa decemlineata, juvenile hormones (JHs) play primary roles in the regulation of metamorphosis, reproduction and diapause. In JH biosynthetic pathway in insect corpora allata, methylation of farnesoic acid or JH acid using S-adenosyl-L-methionine generates a potent feedback inhibitor S-adenosyl-L-homocysteine (AdoHcy). Rapid removal of AdoHcy is hypothesized to be essential for JH synthesis. AdoHcy hydrolase (SAHase) is the only eukaryotic enzyme catalyzing the removal. In the present paper, we firstly cloned a putative LdSAHase gene from L. decemlineata. The cDNA consists of 1806 bp and encodes a 525 amino acid protein. LdSAHase was expressed in all developmental stages. The gene had the highest and the lowest level of transcription respectively in the 3rd- and 4th-instars' heads that contain corpora allata, which was positively correlated with JH titer in the haemolymph and the mRNA level of a JH early-inducible gene, the Krüppel homolog 1 gene (Kr-h1). Secondly, dietary ingestion of bacterially-expressed LdSAHase-dsRNA significantly decreased LdSAHase and LdKr-h1 mRNA levels, reduced JH titer, and caused the death of the larvae, and the failure of pupation and adult emergence. After continuous exposure for 12 days, 42% of the larvae died, 65% of the prepupae failed to pupate and 100% of the pupae failed to emerge. Moreover, RNAi-mediated LdSAHase knockdown also reduced larval developing time, and decreased larval weight. Lastly, application of JH analogue pyriproxyfen to LdSAHase-dsRNA-exposed larvae did not greatly increase LdSAHase expression level and JH content, but up-regulated LdKr-h1 mRNA level. Expectedly, pyriproxyfen application could partially rescue the negative effects on the survival and the development. Thus, our results support the hypothesis that SAHase plays a critical role in JH biosynthesis in insects.

  5. Acute exposure to tris (2-butoxyethyl) phosphate (TBOEP) affects growth and development of embryo-larval zebrafish.

    Science.gov (United States)

    Liu, Yiran; Wu, Ding; Xu, Qinglong; Yu, Liqin; Liu, Chunsheng; Wang, Jianghua

    2017-10-01

    Tris (2-butoxyethyl) phosphate (TBOEP), is used as a flame retardant worldwide. It is an additive in materials and can be easily discharged into the surrounding environment. There is evidence linking TBOEP exposure to abnormal development and growth in zebrafish embryos/larvae. Here, using zebrafish embryo as a model, we investigated toxicological effects on developing zebrafish (Danio rerio) caused by TBOEP at concentrations of 0, 20, 200, 1000, 2000μg/L starting from 2h post-fertilization (hpf). Our findings revealed that TBOEP exposure caused developmental toxicity, such as malformation, growth delay and decreased heart rate in zebrafish larvae. Correlation analysis indicated that inhibition of growth was possibly due to down-regulation of expression of genes related to the growth hormone/insulin-like growth factor (GH/IGF) axis. Furthermore, exposure to TBOEP significantly increased thyroxine (T4) and 3,5,3'-triiodothyronine (T3) in whole larvae. In addition, changed expression of genes involved in the hypothalamic-pituitary-thyroid (HPT) axis was observed, indicating that perturbation of HPT axis might be responsible for the developmental damage and growth delay induced by TBOEP. The present study provides a new set of evidence that exposure of embryo-larval zebrafish to TBOEP can cause perturbation of GH/IGF axis and HPT axis, which could result in developmental impairment and growth inhibition. Copyright © 2017. Published by Elsevier B.V.

  6. Extended incubation affects larval morphology, hatching success and starvation resistance in a terrestrially spawning fish, Galaxias maculatus (Jenyns 1842).

    Science.gov (United States)

    Semmens, D; Swearer, S E

    2011-10-01

    The effect of extended incubation (delayed hatching) on larval morphology in the terrestrially spawning common galaxias Galaxias maculatus was investigated by inducing larvae to hatch 1 and 2 weeks after the normal 2 week incubation period. After 1 week of extended incubation, larvae were larger (longer in standard length, L(S), and greater in body depth) compared to controls (larvae that experienced normal incubation durations). After 2 weeks of extended incubation, larvae were smaller (shorter in L(S) and smaller in body depth) than larvae that experienced 1 week of extended incubation. Furthermore, eye area increased while yolk-sac size decreased monotonically with increasing incubation duration. These results suggest that larvae experiencing long periods of extended incubation are using somatic tissue to meet their metabolic demands. Larvae that experienced 2 weeks of extended incubation succumbed to starvation sooner than control larvae, but hatching success was not significantly different. Temperature mediated the effect of extended incubation on the morphology of larvae at hatching, most likely, through its effects on developmental rate and efficiency of yolk utilization. This study demonstrates some of the consequences of terrestrial spawning with extended incubation, which will assist in determining why this intriguing behaviour has evolved several times in a diverse range of taxa.

  7. Maternal presence and environmental enrichment affect food neophobia of piglets

    NARCIS (Netherlands)

    Oostindjer, M.; Mas Muñoz, J.; Brand, van den H.; Kemp, B.; Bolhuis, J.E.

    2011-01-01

    Young omnivores show food neophobia in order to avoid the potential harmful effects of ingesting unfamiliar food items. We investigated whether the presence of the mother and an enriched rearing environment would reduce food neophobia in piglets. A mother may provide information on suitable food typ

  8. Short 5'-flanking regions of the Amy gene of Drosophila kikkawai affect amylase gene expression and respond to food environments.

    Science.gov (United States)

    Inomata, Nobuyuki; Nakashima, Shuichi

    2008-04-15

    Evolution of the duplicated genes and regulation in gene expression is of great interest, especially in terms of adaptation. Molecular population genetic and evolutionary studies on the duplicated amylase genes of Drosophila species have suggested that their 5'-flanking (cis-regulatory) regions play an important role in evolution of these genes. For better understanding of evolution of the duplicated amylase genes and gene expression, we studied functional significance of the Amy1 gene of Drosophila kikkawai using in vitro deletion mutagenesis followed by P-element-mediated germline transformation. We found that a 1.6-kb of the 5'-flanking region can produce strikingly higher level of larval amylase activity on starch food compared with that on glucose food. We found two cis-regulatory elements, which increase larval amylase activity on starch food. We also found a larval cis-regulatory element, which responds to the food difference. This food-response element is necessary for the function of the element increasing larval activity on starch food. A 5-bp deletion in a putative GRE caused high amylase activity, indicating a cis-regulatory element decreasing amylase activity. These cis-regulatory elements identified in the 5'-flanking region could be the targets of natural selection.

  9. Are You Sure? Confidence about the Satiating Capacity of a Food Affects Subsequent Food Intake

    Directory of Open Access Journals (Sweden)

    Helgi B. Schiöth

    2015-06-01

    Full Text Available Expectations about a food’s satiating capacity predict self-selected portion size, food intake and food choice. However, two individuals might have a similar expectation, but one might be extremely confident while the other might be guessing. It is unclear whether confidence about an expectation affects adjustments in energy intake at a subsequent meal. In a randomized cross-over design, 24 subjects participated in three separate breakfast sessions, and were served a low-energy-dense preload (53 kcal/100 g, a high-energy-dense preload (94 kcal/100 g, or no preload. Subjects received ambiguous information about the preload’s satiating capacity and rated how confident they were about their expected satiation before consuming the preload in its entirety. They were served an ad libitum test meal 30 min later. Confidence ratings were negatively associated with energy compensation after consuming the high-energy-dense preload (r = −0.61; p = 0.001. The same relationship was evident after consuming the low-energy-dense preload, but only after controlling for dietary restraint, hunger prior to, and liking of the test meal (p = 0.03. Our results suggest that confidence modifies short-term controls of food intake by affecting energy compensation. These results merit consideration because imprecise caloric compensation has been identified as a potential risk factor for a positive energy balance and weight gain.

  10. Maternal presence and environmental enrichment affect food neophobia of piglets

    OpenAIRE

    Oostindjer, Marije; Muñoz, Julia Mas; van den Brand, Henry; Kemp, Bas; Bolhuis, J. Elizabeth

    2010-01-01

    Young omnivores show food neophobia in order to avoid the potential harmful effects of ingesting unfamiliar food items. We investigated whether the presence of the mother and an enriched rearing environment would reduce food neophobia in piglets. A mother may provide information on suitable food types to include in the diet, whereas an enriched environment may stimulate behavioural development and reduce reactivity towards novel stimuli (including food). Five barren-reared or enriched-reared ...

  11. Acute toxicity of aromatic and non-aromatic fractions of naphthenic acids extracted from oil sands process-affected water to larval zebrafish.

    Science.gov (United States)

    Scarlett, A G; Reinardy, H C; Henry, T B; West, C E; Frank, R A; Hewitt, L M; Rowland, S J

    2013-09-01

    The toxicity of oil sands process-affected water (OSPW) has regularly been attributed to naphthenic acids, which exist in complex mixtures. If on remediation treatment (e.g., ozonation) or on entering the environment, the mixtures of these acids all behave in the same way, then they can be studied as a whole. If, however, some acids are resistant to change, whilst others are not, or are less resistant, it is important to establish which sub-classes of acids are the most toxic. In the present study we therefore assayed the acute toxicity to larval fish, of a whole acidified OSPW extract and an esterifiable naphthenic acids fraction, de-esterified with alkali: both fractions were toxic (LC50 ∼5-8mgL(-1)). We then fractionated the acids by argentation solid phase extraction of the esters and examined the acute toxicity of two fractions: a de-esterified alicyclic acids fraction, which contained, for example, adamantane and diamantane carboxylic acids, and an aromatic acids fraction. The alicyclic acids were toxic (LC50 13mgL(-1)) but the higher molecular weight aromatic acids fraction was somewhat more toxic, at least on a weight per volume basis (LC50 8mgL(-1); P<0.05) (for comparison, the monoaromatic dehydroabietic acid had a LC50 of ∼1mgL(-1)). These results show how toxic naphthenic acids of OSPW are to these larval fish and that on a weight per volume basis, the aromatic acids are at least as toxic as the 'classical' alicyclic acids. The environmental fates and other toxic effects, if any, of the fractions remain to be established. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Influence of food restriction on the reproduction and larval performance of matrinxã, Brycon amazonicus (Spix and Agassiz, 1829

    Directory of Open Access Journals (Sweden)

    ACS. Camargo

    Full Text Available This work evaluated the effect of food restriction and refeeding of matrinxã females, Brycon amazonicus, on their reproductive performance and on the growth and survival of the progeny. Broodstocks were distributed in 8 earthen tanks (15 fish/tank and fish from 4 tanks were fed daily (G1 while fish from the other 4 tanks were fed for 3 days and not fed for 2 days (G2 during 6 months prior to artificial spawning. Among the induced females, 57% in G1 group and 45% in G2 group spawned and the mean egg weights were 208.1 g (G1 and 131.6 g (G2. Oocytes of G2 fish were smaller (1.017 ± 0.003 mm than oocytes of G1 fish (1.048 ± 0.002 mm. Fertilization (71.91 ± 12.6% and 61.18 ± 13.7% and hatching (61.28 ± 33.9% and 67.50 ± 23.4% rates did not differ between G1 and G2 fish. Larvae were collected at hatching and at 24, 48 and 72 hours of incubation and fixed for growth measurement. After incubation, fry were transferred to aquaria and sampled 1, 5, 9 and 15 days later. G1 and G2 larvae had similar weight (1.51 ± 0.15 and 1.46 ± 0.07 mg but the G2 length was significantly higher (6.26 ± 0.13 and 6.74 ± 0.14 mm. By the ninth day of rearing, G2 fry had higher weight (13.6 ± 0.26 and 18.9 ± 0.07 mg and length (11.8 ± 0.09 and 14.5 ± 0.04 mm but by the fifteenth day, G1 fry had higher weight (90.2 ± 1.19 and 68.6 ± 0.77 mg and length (18.8 ± 0.16 and 18.5 ± 0.04 mm than G2 fry. By the ninth day of rearing, when fry are recommended to be transferred to outdoor tanks, G2 fry were larger and after 15 days, fry produced by restricted-fed females showed higher survival. The survival rate of G2 progeny by the fifteenth day was significantly higher (24.7 ± 2.07% than that of G1 progeny (19.2 ± 1.91%. The ration restriction (35% reduction imposed on matrinxã broodstock during 6 months prior to spawning reduced the number of spawned females and the egg amount, but it did not affect fertilization and hatching rates. Otherwise restricted

  13. Seasonal diversity of butterflies and their larval food plants in the surroundings of upper Neora Valley National Park, a sub-tropical broad leaved hill forest in the eastern Himalayan landscape, West Bengal, India

    Directory of Open Access Journals (Sweden)

    P. Sengupta

    2014-01-01

    Full Text Available Seasonal butterfly diversity in the adjacent areas of the upper Neora Valley National Park, a part of the Himalayan landscape, was studied. The available larval host plant resources present within, as well as in the adjoining areas of transect were identified. A total of 4163 butterflies representing 161 species belonging to five families were recorded during this study. One-hundred-and-forty-three species of plants belonging to 44 families served as the larval food plants of butterflies. The maximum number of butterfly species and maximum number of individuals were sampled during the monsoons. The monsoons with least skewed rank abundance curve of species distribution, was also marked by maximum species diversity and maximum species evenness. This was probably due to the abundant distribution of luxurious vegetation that served as food plants for the larval stages of butterflies. Nymphalidae was the most dominant family with 43.48% of the total number of species. Autumn followed by the monsoon was associated with high species richness probably due to the abundance of vegetation that provides foliage to its larval stages.

  14. Larval growth rate and sex determine resource allocation and stress responsiveness across life stages in juvenile frogs.

    Science.gov (United States)

    Warne, Robin W; Crespi, Erica J

    2015-03-01

    The extent to which interactions between environmental stressors and phenotypic variation during larval life stages impose carry-over effects on adult phenotypes in wildlife are not clear. Using semi-natural mesocosms, we examined how chronically low food availability and size-specific phenotypes in larval amphibians interact and carry over to influence frog growth, resource allocation, endocrine activity and survival. We tagged three cohorts of larvae that differed in body size and developmental stage at 3 weeks after hatching, and tracked them through 10 weeks after metamorphosis in high and low food conditions. We found that growth and development rates during the early tadpole stage not only affected metamorphic rates, but also shaped resource allocation and stress responsiveness in frogs: the slowest growing larvae from low-food mesocosms exhibited a suppressed glucocorticoid response to a handling stressor; reduced growth rate and fat storage as frogs. We also show for the first time that larval developmental trajectories varied with sex, where females developed faster than males especially in food-restricted conditions. Last, while larval food restriction profoundly affected body size in larvae and frogs, time to metamorphosis was highly constrained, which suggests that the physiology and development of this ephemeral pond-breeding amphibian is adapted for rapid metamorphosis despite large potential variation in nutrient availability. Taken together, these results suggest that larval phenotypic variation significantly influences multiple dimensions of post-metamorphic physiology and resource allocation, which likely affect overall performance.

  15. How can Early Life Flavor Experiences Affect Food Preferences?

    Directory of Open Access Journals (Sweden)

    Seray Kabaran

    2017-01-01

    Full Text Available Early experiences with food flavors lead up to children’s food preferences and develop long-lasting flavor preferences and healthy eating habits. The process of flavor learning begins during pregnancy by the foods eaten by mothers which pass to the amniotic fluid. Some flavors coming from the mother’s diet that pass to the amniotic fluid are detected by the fetus. This flavor learning continues after birth with breastfeeding, since the human milk is composed of flavors which reflect the foods consumed by the mother. Flavor composition in human milk which changes during the course of lactation due to the transmission of flavors into human milk enables the baby to get used to new flavors. Therefore, breastfed infants are likely to accept flavor changes and novel flavors more than formula fed infants. Flavor learning continues with starting complementary foods and eating the foods directly. Exposure to a specific flavor and repeated exposures in different times may facilitate the acceptance of this flavor. Furthermore, infants exposed to a variety of foods accept new flavors than infants following a monotonous diet. This underlines the importance of promoting the access to a variety of foods in early childhood. In conclusion, pregnant and lactating women should have variety of healthy foods in their diets with a variety of flavors and they should be encouraged to breastfeed their babies. In addition, starting complementary foods and early repeated exposure to a wide variety of healthy foods, the infants should get familiar with the flavor of healthy and various food. These factors may influence the development of healthy food preferences and healthy eating habits in later periods.

  16. Larval starvation to satiation: influence of nutrient regime on the success of Acanthaster planci.

    Directory of Open Access Journals (Sweden)

    Kennedy Wolfe

    Full Text Available High density populations of the crown-of-thorns seastar, Acanthaster planci, are a major contributor to the decline of coral reefs, however the causes behind periodic outbreaks of this species are not understood. The enhanced nutrients hypothesis posits that pulses of enhanced larval food in eutrophic waters facilitate metamorphic success with a flow-on effect for population growth. The larval resilience hypothesis suggests that A. planci larvae naturally thrive in tropical oligotrophic waters. Both hypotheses remain to be tested empirically. We raised A. planci larvae in a range of food regimes from starvation (no food to satiation (excess food. Algal cell concentration and chlorophyll levels were used to reflect phytoplankton conditions in nature for oligotrophic waters (0-100 cells ml(-1; 0-0.01 μg chl a L(-1, natural background levels of nutrients on the Great Barrier Reef (GBR (1,000-10,000 cells ml(-1; 0.1-1.0 μg chl a L(-1, and enhanced eutrophic conditions following runoff events (100,000 cells ml(-1; 10 μg chl a L(-1. We determine how these food levels affected larval growth and survival, and the metamorphic link between larval experience and juvenile quality (size in experiments where food ration per larvae was carefully controlled. Phytoplankton levels of 1 μg chl a L(-1, close to background levels for some reefs on the GBR and following flood events, were optimal for larval success. Development was less successful above and below this food treatment. Enhanced larval performance at 1 μg chl a L(-1 provides empirical support for the enhanced nutrients hypothesis, but up to a limit, and emphasizes the need for appropriate mitigation strategies to reduce eutrophication and the consequent risk of A. planci outbreaks.

  17. Larval Starvation to Satiation: Influence of Nutrient Regime on the Success of Acanthaster planci

    Science.gov (United States)

    Wolfe, Kennedy; Graba-Landry, Alexia; Dworjanyn, Symon A.; Byrne, Maria

    2015-01-01

    High density populations of the crown-of-thorns seastar, Acanthaster planci, are a major contributor to the decline of coral reefs, however the causes behind periodic outbreaks of this species are not understood. The enhanced nutrients hypothesis posits that pulses of enhanced larval food in eutrophic waters facilitate metamorphic success with a flow-on effect for population growth. The larval resilience hypothesis suggests that A. planci larvae naturally thrive in tropical oligotrophic waters. Both hypotheses remain to be tested empirically. We raised A. planci larvae in a range of food regimes from starvation (no food) to satiation (excess food). Algal cell concentration and chlorophyll levels were used to reflect phytoplankton conditions in nature for oligotrophic waters (0-100 cells ml-1; 0-0.01 μg chl a L-1), natural background levels of nutrients on the Great Barrier Reef (GBR) (1,000-10,000 cells ml-1; 0.1-1.0 μg chl a L-1), and enhanced eutrophic conditions following runoff events (100,000 cells ml-1; 10 μg chl a L-1). We determine how these food levels affected larval growth and survival, and the metamorphic link between larval experience and juvenile quality (size) in experiments where food ration per larvae was carefully controlled. Phytoplankton levels of 1 μg chl a L-1, close to background levels for some reefs on the GBR and following flood events, were optimal for larval success. Development was less successful above and below this food treatment. Enhanced larval performance at 1 μg chl a L-1 provides empirical support for the enhanced nutrients hypothesis, but up to a limit, and emphasizes the need for appropriate mitigation strategies to reduce eutrophication and the consequent risk of A. planci outbreaks. PMID:25790074

  18. Presentation and interpretation of food intake data: factors affecting comparability across studies

    OpenAIRE

    Faber, Mieke; Wenhold, Friede A.M.; MacIntyre, Una E.; Wentzel-Viljoen, Edelweiss; Steyn, Nelia P

    2013-01-01

    Non-uniform, unclear, or incomplete presentation of food intake data limits interpretation, usefulness, and comparisons across studies. In this contribution, we discuss factors affecting uniform reporting of food intake across studies. The amount of food eaten can be reported as mean portion size, number of servings or total amount of food consumed per day; the absolute intake value for the specific study depends on the denominator used because food intake data can be presented...

  19. Food depictions in picture books for preschool children: Frequency, centrality, and affect.

    Science.gov (United States)

    Goldman, Jane A; Descartes, Lara

    2016-01-01

    The food content and messages depicted in popular children's picture books were examined using a set of 100 "Favorite Books for Preschoolers." Sixty-nine of these books depicted food and comprised the sample. Examined were: the types and frequencies of food depicted in the text and/or illustrations of the books; the centrality (central, background); and the affect (positive, neutral, or negative) of those depictions. Each food item was counted, categorized by type, and where possible, coded for centrality and affect. Fruit was the most frequently depicted food, followed by sweetened baked goods, dairy, and vegetables. However, centrality and affect differed for these foods. For example, sweet baked goods were high in both centrality and affect. In contrast vegetables were relatively high in centrality but most often neutral in affect. Ice cream, although not in many books, always was associated with positive outcomes. Results were compared to findings in the literature on food messages presented in children's television programs. The ratio of healthy foods to nutrient-poor foods was higher in the books. However, as in television, the books emphasized the desirability of sweetened foods. The results point to the need for detailed analyses of the types of presentations associated with different foods presented in books for children, as well as for continued investigations into food messages in the growing range of media available to young children.

  20. Key External Influences Affecting Consumers’ Decisions Regarding Food

    Science.gov (United States)

    Martínez-Ruiz, María Pilar; Gómez-Cantó, Carmen María

    2016-01-01

    Among the numerous internal and external forces that compete for consumers’ attention in the context in which they buy their food, this paper will seek to provide a review of the most important external influences, such as the variables related to food itself. To this end, in addition to the food attributes traditionally identified in fields such as consumer behavior, it will give special consideration to the classification of food values. Although the influence of these variables on consumer decisions depends on the individual, analyzing them will undoubtedly increase understanding of consumers’ decisions. Additionally, identifying and describing these variables will enable subsequent research on how they influence both consumer behavior and other key outcomes for producers, manufacturers, and retailers in the food industry, such as satisfaction, trust, and loyalty. PMID:27803686

  1. Using the Larval Zebrafish Locomotor Asssay in Functional Neurotoxicity Screening: Light Brightness and the Order of Stimulus Presentation Affect the Outcome

    Science.gov (United States)

    We are evaluating methods to screen/prioritize large numbers of chemicals using 6 day old zebrafish (Danio rerio) as an alternative model for detecting neurotoxic effects. Our behavioral testing paradigm simultaneously tests individual larval zebrafish under sequential light and...

  2. Visual food cues decrease postprandial glucose concentrations in lean and obese men without affecting food intake and related endocrine parameters.

    Science.gov (United States)

    Brede, Swantje; Sputh, Annika; Hartmann, Ann-Christin; Hallschmid, Manfred; Lehnert, Hendrik; Klement, Johanna

    2017-10-01

    The abundance of highly palatable food items in our environment represents a possible cause of overconsumption. Neuroimaging studies in humans have demonstrated that watching pictures of food increases activation in brain areas involved in homeostatic and hedonic food cue processing. Nevertheless, the impact of food cues on actual food intake and metabolic parameters has not been systematically investigated. We tested the hypothesis that watching high-calorie food cues increases food intake and modifies anticipatory blood parameters in lean and especially in obese men. In 20 normal-weight and 20 obese healthy fasted men, we assessed the effects of watching pictures of high-calorie food items versus neutral contents on food intake measured during a standardized test buffet and subsequent snacking as well as on glucose homeostasis and endocrine parameters. Compared to neutral pictures, viewing food pictures reduced postprandial blood glucose concentrations in lean (p = 0.016) and obese (p = 0.044) subjects, without any differences in insulin or C-peptide concentrations (all p > 0.4). Viewing food pictures did not affect total calorie intake during the buffet (all p > 0.5) and snack consumption (all p > 0.4). Concentrations of ghrelin, adrenocorticotropic hormone (ACTH), cortisol, and glucagon also remained unaffected (all p > 0.08). These data indicate that preprandial processing of food cues curbs postprandial blood glucose excursions, without immediately affecting eating behavior in normal-weight and obese men. Findings indicate that exposure to food cues does not acutely trigger calorie overconsumption but rather improves the glucoregulatory response to food intake. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. How Can Interdisciplinarity Of food, Design, Architecture, Engineering And Pedagogy Affect Children's Eating Habits And Food Preferences?

    DEFF Research Database (Denmark)

    Fisker, Anna Marie; Hermanssdottir, Sunna; Rasmussen, Mai

    , that affect children’s eating habits and food preferences. In order to make evidence in the field, an interdisciplinary team consisting of food specialists, designers, engineers, architects and pedagogues, created a carrot pavilion and appurtenant carrot activities. The aim was to influence the children...... to create a positive and strong relationship to the carrot, and therefore the activities were all based on sensory and playfulness, as results show, that sensory education has positive effect on children’s food preferences (Reverdy et al, 2010) and positive reinforcement retrains the brain to learn new...... of 3-5 years old. The results were positive and underpinning the thesis: integrating feedstock in context and activities can affect children's eating habits and food preferences. Based on the carrot case, the poster will present how the interdisciplinary approach involving food, design, architecture...

  4. Heparanase affects food intake and regulates energy balance in mice.

    Directory of Open Access Journals (Sweden)

    Linda Karlsson-Lindahl

    Full Text Available Mutation of the melanocortin-receptor 4 (MC4R is the most frequent cause of severe obesity in humans. Binding of agouti-related peptide (AgRP to MC4R involves the co-receptor syndecan-3, a heparan sulfate proteoglycan. The proteoglycan can be structurally modified by the enzyme heparanase. Here we tested the hypothesis that heparanase plays a role in food intake behaviour and energy balance regulation by analysing body weight, body composition and food intake in genetically modified mice that either lack or overexpress heparanase. We also assessed food intake and body weight following acute central intracerebroventricular administration of heparanase; such treatment reduced food intake in wildtype mice, an effect that was abolished in mice lacking MC4R. By contrast, heparanase knockout mice on a high-fat diet showed increased food intake and maturity-onset obesity, with up to a 40% increase in body fat. Mice overexpressing heparanase displayed essentially the opposite phenotypes, with a reduced fat mass. These results implicate heparanase in energy balance control via the central melanocortin system. Our data indicate that heparanase acts as a negative modulator of AgRP signaling at MC4R, through cleavage of heparan sulfate chains presumably linked to syndecan-3.

  5. Organizational factors affecting safety implementation in food companies in Thailand.

    Science.gov (United States)

    Chinda, Thanwadee

    2014-01-01

    Thai food industry employs a massive number of skilled and unskilled workers. This may result in an industry with high incidences and accident rates. To improve safety and reduce the accident figures, this paper investigates factors influencing safety implementation in small, medium, and large food companies in Thailand. Five factors, i.e., management commitment, stakeholders' role, safety information and communication, supportive environment, and risk, are found important in helping to improve safety implementation. The statistical analyses also reveal that small, medium, and large food companies hold similar opinions on the risk factor, but bear different perceptions on the other 4 factors. It is also found that to improve safety implementation, the perceptions of safety goals, communication, feedback, safety resources, and supervision should be aligned in small, medium, and large companies.

  6. Can diet composition affect behaviour in dogs? : food for thought

    NARCIS (Netherlands)

    Bosch, G.

    2009-01-01

    The consumption of food goes beyond the basic provision of energy and essential nutrients for the maintenance of physical health. Studies in rats, pigs, and human subjects have shown that behaviour and mood can be influenced by specific nutrients consumed. The research described in this thesis aimed

  7. 76 FR 65734 - Guidance for Industry on Evaluating the Safety of Flood-Affected Food Crops for Human Consumption...

    Science.gov (United States)

    2011-10-24

    ...-Affected Food Crops for Human Consumption; Availability AGENCY: Food and Drug Administration, HHS. ACTION... entitled ``Guidance for Industry: Evaluating the Safety of Flood-Affected Food Crops for Human Consumption... information on how to evaluate the safety of flood-affected food crops for human consumption. DATES:...

  8. Food-cue affected motor response inhibition and self-reported dieting success: a pictorial affective shifting task

    Directory of Open Access Journals (Sweden)

    Adrian eMeule

    2014-03-01

    Full Text Available Behavioral inhibition is one of the basic facets of executive functioning and is closely related to self-regulation. Impulsive reactions, i.e. low inhibitory control, have been associated with higher body-mass-index (BMI, binge eating, and other problem behaviors (e.g. substance abuse, pathological gambling, etc.. Nevertheless, studies which investigated the direct influence of food-cues on behavioral inhibition have been fairly inconsistent. In the current studies, we investigated food-cue affected behavioral inhibition in young women. For this purpose, we used a go/no-go task with pictorial food and neutral stimuli in which stimulus-response mapping is reversed after every other block (affective shifting task. In study 1, hungry participants showed faster reaction times to and omitted fewer food than neutral targets. Low dieting success and higher BMI were associated with behavioral disinhibition in food relative to neutral blocks. In study 2, both hungry and satiated individuals were investigated. Satiation did not influence overall task performance, but modulated associations of task performance with dieting success and self-reported impulsivity. When satiated, increased food craving during the task was associated with low dieting success, possibly indicating a preload-disinhibition effect following food intake. Food-cues elicited automatic action and approach tendencies regardless of dieting success, self-reported impulsivity, or current hunger levels. Yet, associations between dieting success, impulsivity, and behavioral food-cue responses were modulated by hunger and satiation. Future research investigating clinical samples and including other salient non-food stimuli as control category is warranted.

  9. Can diet composition affect behaviour in dogs? : food for thought

    OpenAIRE

    Bosch, G

    2009-01-01

    The consumption of food goes beyond the basic provision of energy and essential nutrients for the maintenance of physical health. Studies in rats, pigs, and human subjects have shown that behaviour and mood can be influenced by specific nutrients consumed. The research described in this thesis aimed to evaluate the impact of dietary composition on two physiological systems involved in the regulation of canine behaviour. In other studies it has been shown that physical activity of pigs can be ...

  10. Double trouble. Trait food craving and impulsivity interactively predict food-cue affected behavioral inhibition.

    Science.gov (United States)

    Meule, Adrian; Kübler, Andrea

    2014-08-01

    Impulsivity and food craving have both been implicated in overeating. Recent results suggest that both processes may interactively predict increased food intake. In the present study, female participants performed a Go/No-go task with pictures of high- and low-calorie foods. They were instructed to press a button in response to the respective target category, but withhold responses to the other category. Target category was switched after every other block, thereby creating blocks in which stimulus-response mapping was the same as in the previous block (nonshift blocks) and blocks in which it was reversed (shift blocks). The Food Cravings Questionnaires and the Barratt Impulsiveness Scale were used to assess trait and state food craving and attentional, motor, and nonplanning impulsivity. Participants had slower reaction times and more omission errors (OE) in high-calorie than in low-calorie blocks. Number of commission errors (CE) and OE was higher in shift blocks than in nonshift blocks. Trait impulsivity was positively correlated with CE in shift blocks while trait food craving was positively correlated with CE in high-calorie blocks. Importantly, CE in high-calorie-shift blocks were predicted by an interaction of food craving × impulsivity such that the relationship between food craving and CE was particularly strong at high levels of impulsivity, but vanished at low levels of impulsivity. Thus, impulsive reactions to high-calorie food-cues are particularly pronounced when both trait impulsivity and food craving is high, but low levels of impulsivity can compensate for high levels of trait food craving. Results support models of self-regulation which assume that interactive effects of low top-down control and strong reward sensitive, bottom-up mechanisms may determine eating-related disinhibition, ultimately leading to increased food intake.

  11. Factors affecting food security and contribution of modern technologies in food sustainability.

    Science.gov (United States)

    Premanandh, Jagadeesan

    2011-12-01

    The concept of food insecurity is complex and goes beyond the simplistic idea of a country's inability to feed its population. The global food situation is redefined by many driving forces such as population growth, availability of arable lands, water resources, climate change and food availability, accessibility and loss. The combined effect of these factors has undeniably impacted global food production and security. This article reviews the key factors influencing global food insecurity and emphasises the need to adapt science-based technological innovations to address the issue. Although anticipated benefits of modern technologies suggest a level of food production that will sustain the global population, both political will and sufficient investments in modern agriculture are needed to alleviate the food crisis in developing countries. In this globalised era of the 21st century, many determinants of food security are trans-boundary and require multilateral agreements and actions for an effective solution. Food security and hunger alleviation on a global scale are within reach provided that technological innovations are accepted and implemented at all levels.

  12. Socio-cultural and economic factors affecting food consumption patterns in the Arab countries.

    Science.gov (United States)

    Musaiger, A O

    1993-04-01

    Several factors have been found to determine the dietary habits of the people in the Arab world. Food consumption pattern has dramatically changed in some Arab countries as a result of sudden increase in income from oil revenue. It is believed that food subsidy policy has adversely affected the food habits in the Gulf states by encouraging the intake of fat, sugar, rice, wheat flour and meat. Socio-cultural factors such as religion, beliefs, food preferences, gender discrimination, education and women's employment all have a noticeable influence on food consumption patterns in this region. Mass media, especially televised food advertisements, play an important role in modifying the dietary habits. The migration movement, particularly that which was carried out during the 70s has a great impact on the food practices in many Arab countries. Comprehensive studies on social, cultural and economic factors associated with food consumption patterns in the Arab region are highly recommended.

  13. Food as Risk: How Eating Habits and Food Knowledge Affect Reactivity to Pictures of Junk and Healthy Foods.

    Science.gov (United States)

    Yegiyan, Narine S; Bailey, Rachel L

    2016-01-01

    This study explores how people respond to images of junk versus healthy food as a function of their eating habits and food knowledge. The experiment reported here proposed and tested the idea that those with unhealthy eating habits but highly knowledgeable about healthy eating would feel more positive and also more negative toward junk food images compared to images of healthy food because they may perceive them as risky--desirable but potentially harmful. The psychophysiological data collected from participants during their exposure to pictures of junk versus healthy food supported this idea. In addition, unhealthy eaters compared to healthy eaters with the same degree of food knowledge responded more positively to all food items. The findings are critical from a health communication perspective. Because unhealthy eaters produce stronger emotional responses to images of junk food, they are more likely to process information associated with junk food with more cognitive effort and scrutiny. Thus, when targeting this group and using images of junk food, it is important to combine these images with strong message claims and relevant arguments; otherwise, if the arguments are perceived as irrelevant or weak, the motivational activation associated with junk food itself may transfer into an increased desire to consume the unhealthy product.

  14. Plate size does not affect perception of food portion size.

    Science.gov (United States)

    Penaforte, F R O; Japur, C C; Diez-Garcia, R W; Hernandez, J C; Palmma-Linares, I; Chiarello, P G

    2014-04-01

    Evidences have suggested that larger utensils may provoke 'size-contrast illusions', influencing the perceived volume and food consumption. To analyse the influence of plate size on the visual estimate of food portion size. Two 400 g portions of pasta with tomato sauce were presented on two plates of different diameters (24.0 and 9.0 cm). Each participant visually estimated on an individual basis the quantities of the pasta portions (g) present on each plate. In addition, each subject classified the size of the portions on each plate as 'small', 'medium' and 'large'. The mean estimates of the amount of pasta on each plate were compared by the nonparametric Mann-Whitney. The differences in the frequencies of portion classifications between plates were evaluated by the chi-squared test. Forty-eight students (average 25.8 ± 8.9 years) participated in the study. There was no difference in the median amount of pasta estimated for the large and small plates (150 g; range 50-500 and 115 g; range 40-500 g, respectively). The classification of the portion size as 'large' was reported by a significantly greater number of persons when they evaluated the amount of pasta arranged on the large plate compared to the small plate (47.9 versus 22.9%, respectively; P = 0.018). The size of the plate did not influence the estimate of food portions, even though it did influence the classification of portion size. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  15. Food microstructure affects the bioavailability of several nutrients.

    Science.gov (United States)

    Parada, J; Aguilera, J M

    2007-03-01

    There is an increased interest in the role that some nutrients may play in preventing or ameliorating the effect of major diseases (for example, some types of cancer, cardiovascular diseases, eye disorders, among others). In this respect, the bioavailability or the proportion of an ingested nutrient that is made available (that is, delivered to the bloodstream) for its intended mode of action is more relevant than the total amount present in the original food. Disruption of the natural matrix or the microstructure created during processing may influence the release, transformation, and subsequent absorption of some nutrients in the digestive tract. Alternatively, extracts of bioactive molecules (for example, nutraceuticals) and beneficial microorganisms may be protected during their transit in the digestive system to the absorption sites by encapsulation in designed matrices. This review summarizes relevant in vivo and in vitro methods used to assess the bioavailability of some nutrients (mostly phytochemicals), types of microstructural changes imparted by processing and during food ingestion that are relevant in matrix-nutrient interactions, and their effect on the bioavailability of selected nutrients.

  16. Nutrition research to affect food and a healthy lifespan12

    Science.gov (United States)

    Ohlhorst, Sarah D.; Russell, Robert; Bier, Dennis; Klurfeld, David M.; Li, Zhaoping; Mein, Jonathan R.; Milner, John; Ross, A. Catharine; Stover, Patrick; Konopka, Emily

    2013-01-01

    Proper nutrition offers one of the most effective and least costly ways to decrease the burden of many diseases and their associated risk factors, including obesity. Nutrition research holds the key to increasing our understanding of the causes of obesity and its related comorbidities and thus holds promise to markedly influence global health and economies. After outreach to 75 thought leaders, the American Society for Nutrition (ASN) convened a Working Group to identify the nutrition research needs whose advancement will have the greatest projected impact on the future health and well-being of global populations. ASN’s Nutrition Research Needs focus on the following high priority areas: 1) variability in individual responses to diet and foods; 2) healthy growth, development, and reproduction; 3) health maintenance; 4) medical management; 5) nutrition-related behaviors; and 6) food supply/environment. ASN hopes the Nutrition Research Needs will prompt collaboration among scientists across all disciplines to advance this challenging research agenda given the high potential for translation and impact on public health. Furthermore, ASN hopes the findings from the Nutrition Research Needs will stimulate the development and adoption of new and innovative strategies that can be applied toward the prevention and treatment of nutrition-related diseases. The multidisciplinary nature of nutrition research requires stakeholders with differing areas of expertise to collaborate on multifaceted approaches to establish the evidence-based nutrition guidance and policies that will lead to better health for the global population. In addition to the identified research needs, ASN also identified 5 tools that are critical to the advancement of the Nutrition Research Needs: 1) omics, 2) bioinformatics, 3) databases, 4) biomarkers, and 5) cost-effectiveness analysis. PMID:24038264

  17. Nutrition research to affect food and a healthy life span.

    Science.gov (United States)

    Ohlhorst, Sarah D; Russell, Robert; Bier, Dennis; Klurfeld, David M; Li, Zhaoping; Mein, Jonathan R; Milner, John; Ross, A Catharine; Stover, Patrick; Konopka, Emily

    2013-08-01

    Proper nutrition offers one of the most effective and least costly ways to decrease the burden of many diseases and their associated risk factors, including obesity. Nutrition research holds the key to increasing our understanding of the causes of obesity and its related comorbidities and thus holds promise to markedly influence global health and economies. After outreach to 75 thought leaders, the American Society for Nutrition (ASN) convened a Working Group to identify the nutrition research needs whose advancement will have the greatest projected impact on the future health and well-being of global populations. ASN's Nutrition Research Needs focus on the following high priority areas: 1) variability in individual responses to diet and foods; 2) healthy growth, development, and reproduction; 3) health maintenance; 4) medical management; 5) nutrition-related behaviors; and 6) food supply/environment. ASN hopes the Nutrition Research Needs will prompt collaboration among scientists across all disciplines to advance this challenging research agenda given the high potential for translation and impact on public health. Furthermore, ASN hopes the findings from the Nutrition Research Needs will stimulate the development and adoption of new and innovative strategies that can be applied toward the prevention and treatment of nutrition-related diseases. The multidisciplinary nature of nutrition research requires stakeholders with differing areas of expertise to collaborate on multifaceted approaches to establish the evidence-based nutrition guidance and policies that will lead to better health for the global population. In addition to the identified research needs, ASN also identified 5 tools that are critical to the advancement of the Nutrition Research Needs: 1) omics, 2) bioinformatics, 3) databases, 4) biomarkers, and 5) cost-effectiveness analysis.

  18. Food can lift mood by affecting mood-regulating neurocircuits via a serotonergic mechanism

    NARCIS (Netherlands)

    Kroes, M.C.W.; Wingen, G.A. van; Wittwer, J.; Mohajeri, M.H.; Kloek, J.; Fernandez, G.S.E.

    2014-01-01

    It is commonly assumed that food can affect mood. One prevalent notion is that food containing tryptophan increases serotonin levels in the brain and alters neural processing in mood-regulating neurocircuits. However, tryptophan competes with other long-neutral-amino-acids (LNAA) for transport acros

  19. Similarities and differences in affective and cognitive origins of food likings and dislikes.

    Science.gov (United States)

    Letarte, A; Dubé, L; Troche, V

    1997-04-01

    In a field study, 355 French-Canadian adults (Caucasians; 119 men, 236 women; average age of 40) freely stated the food item they liked and disliked the most, the reasons for their attitude and the context of their last consumption of these two food items. Content analysis revealed that the origins of food likes and dislikes are at the same time very similar and very different. They are similar in terms of the overwhelming influence of affective factors, in particular sensory experience, in the formation of both positive and negative attitudes toward food. Similarity between origins of food likes and dislikes in the same subjects is higher when they are from affective sources than when they are from cognitive sources. Food likes and dislikes are also similar in terms of the high salience of the social dimension in subjects' memories of consumption contexts. Results also show that food likes and dislikes also differ in many ways. Subjects can more easily elicit attitude bases and consumption contexts for food likes than they do for food dislikes. Beside taste as their common and most frequent base, results show that dislikes originate from more specific (e.g. texture, smell, appearance) and more intense sensory experiences than likes. Further, physiological consequences that contribute to food likes and dislikes are not the same: likes originate from positive nutritional value whereas dislikes follow from negative physiological responses, in particular nausea. Also, specific factors contribute uniquely to likes and dislikes. Functional aspects (e.g. flexibility, preparation) were the second most important reasons for food likes while having almost no influence on dislikes. In contrast, food symbolism was the third most important reason for food dislikes with almost no effect on food likes.

  20. The fate of eggs and larvae of three pelagic species, mackerel (Scomber scombrus, horse mackerel (Trachurus trachurus and sardine (Sardina pilchardus in relation to prevailing currents in the Bay of Biscay: Could they affect larval survival?

    Directory of Open Access Journals (Sweden)

    Paula Alvarez

    2012-05-01

    Full Text Available The spatial distribution of eggs and larvae of three pelagic species, mackerel, horse mackerel and sardine, in the Bay of Biscay was studied in 1998, 2001 and 2004. The spatial distribution was clearly different between the years studied and corresponds quite precisely to different water circulation regimes. Mackerel and horse mackerel larvae are more affected by the prevailing currents than sardine, as their spawning grounds are located offshore, far from the shelf break where the current velocities are higher. Survival rates for mackerel and horse mackerel were higher in 2001, when the offshore larval transport was stronger. However, for sardine, the mortality rate hardly varied between years. The abundance of 25-day-old larvae, considered as an index of the survival rate, appears to be a good recruitment indicator, at least for 1998, 2001 and 2004. Our results did not support the hypothesis of Bakun (1996, which states that dispersion of early life stages towards open ocean waters should cause high larval mortality. At least under the conditions observed for the years studied, the retention of larvae offshore appears to have a positive effect on larval growth and/or survival.

  1. Size of food bowl and scoop affects amount of food owners feed their dogs.

    Science.gov (United States)

    Murphy, M; Lusby, A L; Bartges, J W; Kirk, C A

    2012-04-01

    The incidence of canine obesity appears to be increasing dramatically and understanding factors impacting the amount of food pet owners provide their dogs may improve weight management. Human research has shown the size of food bowls, plates and utensils can significantly impact the amount of food portioned and consumed. This effect can be attributed to both the Delboeuf optical illusion and the Ebbinghaus-Titchener size-contrast illusion. To investigate the existence of a similar effect with dog owners, 54 dogs and their owners were recruited for a four treatment randomized prospective trial. Owners scooped out a normal kibble-based meal using a small bowl and small scoop, small bowl and large scoop, large bowl and small scoop or a large bowl and large scoop. Each treatment was used once per owner over four visits. Repeated measures anova revealed the mean amount of food portioned using the small bowl and small scoop was significantly less than all other bowl and scoop combinations (150.7 g vs. 171.5 g vs. 172.7 g vs. 184.5 g, p 0.05). Owners were more likely to portion a larger amount of food with a large bowl and large scoop. Results are consistent with human data and emphasize the need for owners to use standard measuring cups. Results also suggest owner compliance during weight loss programs may be improved with smaller bowls and serving scoops. © 2011 Blackwell Verlag GmbH.

  2. New product, familiar taste: Effects of slogans on cognitive and affective responses to an unknown food product among food neophobics and neophilics

    NARCIS (Netherlands)

    Fenko, Anna; Leufkens, Jean-Marie; van Hoof, Joris Jasper

    2015-01-01

    Food neophobia is considered a potential barrier for the introduction of new food products. This study investigated how advertising slogans could influence cognitive and affective responses to a new product in food neophobics and food neophilics. An unknown dairy product was used to examine the

  3. New product, familiar taste: Effects of slogans on cognitive and affective responses to an unknown food product among food neophobics and neophilics

    NARCIS (Netherlands)

    Fenko, A.; Leufkens, Jean-Marie; Hoof, van J.J.

    2015-01-01

    Food neophobia is considered a potential barrier for the introduction of new food products. This study investigated how advertising slogans could influence cognitive and affective responses to a new product in food neophobics and food neophilics. An unknown dairy product was used to examine the effe

  4. What consumers don't know about genetically modified food, and how that affects beliefs.

    Science.gov (United States)

    McFadden, Brandon R; Lusk, Jayson L

    2016-09-01

    In the debates surrounding biotechnology and genetically modified (GM) food, data from consumer polls are often presented as evidence for precaution and labeling. But how much do consumers actually know about the issue? New data collected from a nationwide U.S. survey reveal low levels of knowledge and numerous misperceptions about GM food. Nearly equal numbers of consumers prefer mandatory labeling of foods containing DNA as do those preferring mandatory labeling of GM foods. When given the option, the majority of consumers prefer that decisions about GM food be taken out of their hands and be made by experts. After answering a list of questions testing objective knowledge of GM food, subjective, self-reported knowledge declines somewhat, and beliefs about GM food safety increase slightly. Results suggest that consumers think they know more than they actually do about GM food, and queries about GM facts cause respondents to reassess how much they know. The findings question the usefulness of results from opinion polls as a motivation for creating public policy surrounding GM food.-McFadden, B. R., Lusk, J. L. What consumers don't know about genetically modified food, and how that affects beliefs.

  5. Meet OLAF, a good friend of the IAPS! The Open Library of Affective Foods: a tool to investigate the emotional impact of food in adolescents.

    Science.gov (United States)

    Miccoli, Laura; Delgado, Rafael; Rodríguez-Ruiz, Sonia; Guerra, Pedro; García-Mármol, Eduardo; Fernández-Santaella, M Carmen

    2014-01-01

    In the last decades, food pictures have been repeatedly employed to investigate the emotional impact of food on healthy participants as well as individuals who suffer from eating disorders and obesity. However, despite their widespread use, food pictures are typically selected according to each researcher's personal criteria, which make it difficult to reliably select food images and to compare results across different studies and laboratories. Therefore, to study affective reactions to food, it becomes pivotal to identify the emotional impact of specific food images based on wider samples of individuals. In the present paper we introduce the Open Library of Affective Foods (OLAF), which is a set of original food pictures created to reliably select food pictures based on the emotions they prompt, as indicated by affective ratings of valence, arousal, and dominance and by an additional food craving scale. OLAF images were designed to allow simultaneous use with affective images from the International Affective Picture System (IAPS), which is a well-known instrument to investigate emotional reactions in the laboratory. The ultimate goal of the OLAF is to contribute to understanding how food is emotionally processed in healthy individuals and in patients who suffer from eating and weight-related disorders. The present normative data, which was based on a large sample of an adolescent population, indicate that when viewing affective non-food IAPS images, valence, arousal, and dominance ratings were in line with expected patterns based on previous emotion research. Moreover, when viewing food pictures, affective and food craving ratings were consistent with research on food cue processing. As a whole, the data supported the methodological and theoretical reliability of the OLAF ratings, therefore providing researchers with a standardized tool to reliably investigate the emotional and motivational significance of food. The OLAF database is publicly available at zenodo.org.

  6. Meet OLAF, a good friend of the IAPS! The Open Library of Affective Foods: a tool to investigate the emotional impact of food in adolescents.

    Directory of Open Access Journals (Sweden)

    Laura Miccoli

    Full Text Available In the last decades, food pictures have been repeatedly employed to investigate the emotional impact of food on healthy participants as well as individuals who suffer from eating disorders and obesity. However, despite their widespread use, food pictures are typically selected according to each researcher's personal criteria, which make it difficult to reliably select food images and to compare results across different studies and laboratories. Therefore, to study affective reactions to food, it becomes pivotal to identify the emotional impact of specific food images based on wider samples of individuals. In the present paper we introduce the Open Library of Affective Foods (OLAF, which is a set of original food pictures created to reliably select food pictures based on the emotions they prompt, as indicated by affective ratings of valence, arousal, and dominance and by an additional food craving scale. OLAF images were designed to allow simultaneous use with affective images from the International Affective Picture System (IAPS, which is a well-known instrument to investigate emotional reactions in the laboratory. The ultimate goal of the OLAF is to contribute to understanding how food is emotionally processed in healthy individuals and in patients who suffer from eating and weight-related disorders. The present normative data, which was based on a large sample of an adolescent population, indicate that when viewing affective non-food IAPS images, valence, arousal, and dominance ratings were in line with expected patterns based on previous emotion research. Moreover, when viewing food pictures, affective and food craving ratings were consistent with research on food cue processing. As a whole, the data supported the methodological and theoretical reliability of the OLAF ratings, therefore providing researchers with a standardized tool to reliably investigate the emotional and motivational significance of food. The OLAF database is publicly

  7. 'Peer pressure' in larval Drosophila?

    Science.gov (United States)

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-06-06

    Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila.

  8. Veronica longifolia L. as an important initial larval food plant of Scarce Fritillary Euphydryas maturna (LINNAEUS, 1758 (Lepidoptera, Nymphalidae: the ecological uniqueness of populations from the Natura 2000 area “Dolina Biebrzy” (Biebrza Valley in NE Poland

    Directory of Open Access Journals (Sweden)

    Sielezniew Marcin

    2016-06-01

    Full Text Available The Euro-Siberian Scarce Fritillary Euphydryas maturna is considered a vulnerable species in the European Union and is listed in Annexes II and IV of the Habitats Directive. The butterfly shows a complex pattern of larval plant use throughout its range. In central Europe females oviposit on some trees and bushes, especially Fraxinus spp., on which hatched larvae spend their pre-diapause phase of development feeding gregariously in conspicuous webs. However, some herbal plants are also reported in the north and east. During a study performed in the Natura 2000 area “Dolina Biebrzy” (Biebrza Valley in NE Poland we recorded populations showing a unique mixture of ecological characteristics. Both Fraxinus excelsior and Veronica longifolia were used as larval food plants before hibernation, and some local populations seemed to be completely dependent on the latter plant. Moreover, in the spring, at one site, we observed larvae feeding on Salix rosmarinifolia - the first host record for this plant species. The importance of our findings for conservation, as well as for the monitoring of the butterfly, is discussed.

  9. Relative Preference and Localized Food Affect Predator Space Use and Consumption of Incidental Prey.

    Science.gov (United States)

    Schartel, Tyler E; Schauber, Eric M

    2016-01-01

    Abundant, localized foods can concentrate predators and their foraging efforts, thus altering both the spatial distribution of predation risk and predator preferences for prey that are encountered incidentally. However, few investigations have quantified the spatial scale over which localized foods affect predator foraging behavior and consumption of incidental prey. In spring 2010, we experimentally tested how point-source foods altered how generalist predators (white-footed mice, Peromyscus leucopus) utilized space and depredated two incidental prey items: almonds (Prunus dulcis; highly profitable) and maple seeds (Acer saccharum; less profitable). We estimated mouse population densities with trapping webs, quantified mouse consumption rates of these incidental prey items, and measured local mouse activity with track plates. We predicted that 1) mouse activity would be elevated near full feeders, but depressed at intermediate distances from the feeder, 2) consumption of both incidental prey would be high near feeders providing less-preferred food and, 3) consumption of incidental prey would be contingent on predator preference for prey relative to feeders providing more-preferred food. Mouse densities increased significantly from pre- to post-experiment. Mean mouse activity was unexpectedly greatest in control treatments, particularly preferred food (sunflower seeds) created localized refuges for incidental prey at intermediate distances (15 to 25m) from the feeder. Feeders with less-preferred food (corn) generated localized high risk for highly preferred almonds food on risk experienced by incidental prey, which can be positive or negative depending on both spatial proximity and relative preference.

  10. Dietary fatty acid composition affects food intake and gut-brain satiety signaling in Senegalese sole (Solea senegalensis, Kaup 1858) larvae and post-larvae.

    Science.gov (United States)

    Bonacic, Kruno; Campoverde, Cindy; Gómez-Arbonés, Javier; Gisbert, Enric; Estevez, Alicia; Morais, Sofia

    2016-03-01

    Little is known how dietary lipids affect food intake during larval development of fish, especially with regard to fatty acid (FA) composition. In fact, very little work has been done on appetite regulation and food intake in fish larvae in general, due to biological and technical difficulties associated with this type of studies. A new method using fluorescent microspheres as markers was developed in this study to evaluate food intake and prey selectivity of Senegalese sole larvae and post-larvae. Food intake was quantified in fish fed Artemia metanauplii enriched with oils differing in FA profile: cod liver oil (CLO), linseed oil (LSO), soybean oil (SBO) or olive oil (OO). The fish did not preferentially ingest a specific diet when presented with a choice. However, pre-metamorphic larvae from the CLO treatment ingested more metanauplii per g body weight, while differences in post-larvae were not significant. These findings were developed further by analyzing mRNA levels of a range of putative anorexigenic (pyya, pyyb, glp1, cckl, cart1a, cart1b, cart2a, cart4, pomca, pomcb, crf) and orexigenic (gal, npy, agrp2) genes, to identify those which are significantly affected by feeding and/or dietary FA composition. The variety of expression patterns observed highlighted the complexity of appetite regulatory mechanisms. In general, fish fed the CLO diet tended to show gene expression patterns most dissimilar to the remaining treatments. Expression in pre-metamorphic larvae was generally less in accordance with the putative function of the genes than in post-larvae, which could suggest a yet underdeveloped regulatory system.

  11. Agroecology and sustainable food systems: Participatory research to improve food security among HIV-affected households in northern Malawi.

    Science.gov (United States)

    Nyantakyi-Frimpong, Hanson; Mambulu, Faith Nankasa; Bezner Kerr, Rachel; Luginaah, Isaac; Lupafya, Esther

    2016-09-01

    This article shares results from a long-term participatory agroecological research project in northern Malawi. Drawing upon a political ecology of health conceptual framework, the paper explores whether and how participatory agroecological farming can improve food security and nutrition among HIV-affected households. In-depth interviews were conducted with 27 farmers in HIV-affected households in the area near Ekwendeni Trading Centre in northern Malawi. The results show that participatory agroecological farming has a strong potential to meet the food, dietary, labour and income needs of HIV-affected households, whilst helping them to manage natural resources sustainably. As well, the findings reveal that place-based politics, especially gendered power imbalances, are imperative for understanding the human impacts of the HIV/AIDS epidemic. Overall, the study adds valuable insights into the literature on the human-environment dimensions of health. It demonstrates that the onset of disease can radically transform the social relations governing access to and control over resources (e.g., land, labour, and capital), and that these altered social relations in turn affect sustainable disease management. The conclusion highlights how the promotion of sustainable agroecology could help to partly address the socio-ecological challenges associated with HIV/AIDS.

  12. Effects of temperature and dietary nitrogen on genetic variation and covariation in gypsy moth larval performance traits

    Directory of Open Access Journals (Sweden)

    Janković-Tomanić Milena

    2012-01-01

    Full Text Available To assess the plastic and genetic components of variation in responses of gypsy moth (Lymantria dispar 4th instar larvae to temperature and food quality, we applied a split-family four-environment experimental design where full-sibs were reared on two constant temperatures (23°C and 28°C and two concentrations of dietary nitrogen (1.5 and 3.7% dry weight. A temperature of 28°C and low dietary nitrogen decreased larval weight and prolonged larval developmental time, while viability was not affected. Only a marginally significant interaction between the two environmental factors was found for larval weight. The broad-sense heritability for larval developmental time did not change across environments, and across-environment genetic correlations were close to one. Heritability for larval weight depended on environmental and across-environmental genetic correlations that were not significant. There was no evidence of a trade-off between developmental time and larval weight. The implications of the obtained results for the evolution of phenotypic plasticity in complex environments are discussed. [Acknowledgments. This work was supported by Ministry of Education and Science of Serbia, grant No. 173027.

  13. Foraging and predation risk for larval cisco (Coregonus artedi) in Lake Superior: a modelling synthesis of empirical survey data

    Science.gov (United States)

    Myers, Jared T.; Yule, Daniel L.; Jones, Michael L.; Quinlan, Henry R.; Berglund, Eric K.

    2014-01-01

    The relative importance of predation and food availability as contributors to larval cisco (Coregonus artedi) mortality in Lake Superior were investigated using a visual foraging model to evaluate potential predation pressure by rainbow smelt (Osmerus mordax) and a bioenergetic model to evaluate potential starvation risk. The models were informed by observations of rainbow smelt, larval cisco, and zooplankton abundance at three Lake Superior locations during the period of spring larval cisco emergence and surface-oriented foraging. Predation risk was highest at Black Bay, ON, where average rainbow smelt densities in the uppermost 10 m of the water column were >1000 ha−1. Turbid conditions at the Twin Ports, WI-MN, affected larval cisco predation risk because rainbow smelt remained suspended in the upper water column during daylight, placing them alongside larval cisco during both day and night hours. Predation risk was low at Cornucopia, WI, owing to low smelt densities (cisco survival at Black Bay and to a lesser extent at Twin Ports, and that starvation may be a major source of mortality at all three locations. The framework we describe has the potential to further our understanding of the relative importance of starvation and predation on larval fish survivorship, provided information on prey resources available to larvae are measured at sufficiently fine spatial scales and the models provide a realistic depiction of the dynamic processes that the larvae experience.

  14. Foraging arena size and structural complexity affect the dynamics of food distribution in ant colonies.

    Science.gov (United States)

    Buczkowski, Grzegorz; VanWeelden, Matthew

    2010-12-01

    Food acquisition by ant colonies is a complex process that starts with acquiring food at the source (i.e., foraging) and culminates with food exchange in or around the nest (i.e., feeding). While ant foraging behavior is relatively well understood, the process of food distribution has received little attention, largely because of the lack of methodology that allows for accurate monitoring of food flow. In this study, we used the odorous house ant, Tapinoma sessile (Say) to investigate the effect of foraging arena size and structural complexity on the rate and the extent of spread of liquid carbohydrate food (sucrose solution) throughout a colony. To track the movement of food, we used protein marking and double-antibody sandwich enzyme-linked immunosorbent assay, DAS-ELISA. Variation in arena size, in conjunction with different colony sizes, allowed us to test the effect of different worker densities on food distribution. Results demonstrate that both arena size and colony size have a significant effect on the spread of the food and the number of workers receiving food decreased as arena size and colony size increased. When colony size was kept constant and arena size increased, the percentage of workers testing positive for the marker decreased, most likely because of fewer trophallactic interactions resulting from lower worker density. When arena size was kept constant and colony size increased, the percentage of workers testing positive decreased. Nonrandom (clustered) worker dispersion and a limited supply of food may have contributed to this result. Overall, results suggest that food distribution is more complete is smaller colonies regardless of the size of the foraging arena and that colony size, rather than worker density, is the primary factor affecting food distribution. The structural complexity of foraging arenas ranged from simple, two-dimensional space (empty arenas) to complex, three-dimensional space (arenas filled with mulch). The structural

  15. Food Restriction Affects Inflammatory Response and Nutritional State in Tuco-tucos (Ctenomys talarum).

    Science.gov (United States)

    Merlo, Julieta Leticia; Cutrera, Ana Paula; Zenuto, Roxana Rita

    2016-12-01

    Insufficient or unbalanced food intake typically has a negative impact on immune responses. The understanding of this effect is, however, hampered by the effect that food has on general condition, which, in turn, affects immunity, and the interaction among general condition, immunocompetence, and concurrent infections. The goal of this study was to determine the effects of food restriction and methionine supplementation on immunity in tuco-tucos (Ctenomys talarum). Effects of diet manipulations on nutritional state, inflammatory response to phytohemagglutinin (PHA), and other immune parameters (bacterial killing capacity, natural antibodies, and leukocyte profile) were evaluated. Health and stress parameters and endoparasite loads were assessed to understand more deeply potential effects of treatments on immune status. Individuals under food restriction presented an altered nutritional state as well as increased stress levels (higher N: L ratios) compared with individuals fed ad libitum, and a marked reduction in the inflammatory response to PHA. Supplementation with methionine did not affect any of the parameters analyzed. Endoparasite loads were not affected by treatments. Our results support the idea that food insufficiency can modulate the individual's immune responsiveness through the lack of adequate essential nutrients, metabolic fuel and energetic reserves, or by a detrimental effect of the stress caused by nutrient limitation. We show that the response to PHA previously reported as nonenergetically costly for C. talarum, implies a nutritional cost; an opposite pattern to that previously found for the adaptive antibody response to sheep red blood cells in the same species.

  16. Inducing negative affect increases the reward value of appetizing foods in dieters.

    Science.gov (United States)

    Wagner, Dylan D; Boswell, Rebecca G; Kelley, William M; Heatherton, Todd F

    2012-07-01

    Experiencing negative affect frequently precedes lapses in self-control for dieters, smokers, and drug addicts. Laboratory research has similarly shown that inducing negative emotional distress increases the consumption of food or drugs. One hypothesis for this finding is that emotional distress sensitizes the brain's reward system to appetitive stimuli. Using functional neuroimaging, we demonstrate that inducing negative affect in chronic dieters increases activity in brain regions representing the reward value of appetitive stimuli when viewing appetizing food cues. Thirty female chronic dieters were randomly assigned to receive either a negative (n = 15) or neutral mood induction (n = 15) immediately followed by exposure to images of appetizing foods and natural scenes during fMRI. Compared with chronic dieters in a neutral mood, those receiving a negative mood induction showed increased activity in the OFC to appetizing food images. In addition, activity to food images in the OFC and ventral striatum was correlated with individual differences in the degree to which the negative mood induction decreased participants' self-esteem. These findings suggest that distress sensitizes the brain's reward system to appetitive cues, thereby offering a mechanism for the oft-observed relationship between negative affect and disinhibited eating.

  17. Ethanol concentration in food and body condition affect foraging behavior in Egyptian fruit bats ( Rousettus aegyptiacus)

    Science.gov (United States)

    Sánchez, Francisco; Korine, Carmi; Kotler, Burt P.; Pinshow, Berry

    2008-06-01

    Ethanol occurs in fleshy fruit as a result of sugar fermentation by both microorganisms and the plant itself; its concentration [EtOH] increases as fruit ripens. At low concentrations, ethanol is a nutrient, whereas at high concentrations, it is toxic. We hypothesized that the effects of ethanol on the foraging behavior of frugivorous vertebrates depend on its concentration in food and the body condition of the forager. We predicted that ethanol stimulates food consumption when its concentration is similar to that found in ripe fruit, whereas [EtOH] below or above that of ripe fruit has either no effect, or else deters foragers, respectively. Moreover, we expected that the amount of food ingested on a particular day of feeding influences the toxic effects of ethanol on a forager, and consequently shapes its feeding decisions on the following day. We therefore predicted that for a food-restricted forager, ethanol-rich food is of lower value than ethanol-free food. We used Egyptian fruit bats ( Rousettus aegyptiacus) as a model to test our hypotheses, and found that ethanol did not increase the value of food for the bats. High [EtOH] reduced the value of food for well-fed bats. However, for food-restricted bats, there was no difference between the value of ethanol-rich and ethanol-free food. Thus, microorganisms, via their production of ethanol, may affect the patterns of feeding of seed-dispersing frugivores. However, these patterns could be modified by the body condition of the animals because they might trade-off the costs of intoxication against the value of nutrients acquired.

  18. The Food Matrix and Sterol Characteristics Affect the Plasma Cholesterol Lowering of Phytosterol/Phytostanol1

    Science.gov (United States)

    Cusack, Laura Kells; Fernandez, Maria Luz; Volek, Jeff S.

    2013-01-01

    Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of common foods. Understanding the cholesterol-lowering impact of the food matrix and the PS characteristics would maximize their success and increase the benefit to consumers. This review systematically examines whether the PS characteristics and the fatty acid composition of foods with added PS affects serum LDL-c. A total of 33 studies published between the years 1998 and 2011 inclusive of 66 individual primary variables (strata) were evaluated. The functional food matrices included margarine, mayonnaise, yogurt, milk, cheese, meat, grain, juice, and chocolate. Consistently, ≥10% reductions in LDL-c were reported when the characteristics of the food matrix included poly- and monounsaturated fatty acids known to lower LDL-c. Also, >10% mean reductions in LDL-c were reported when β-sitostanol and campestanol as well as stanol esters were used. These characteristics allow both low-fat and high-fat foods to successfully incorporate PS and significantly lower LDL-c. PMID:24228192

  19. The food matrix and sterol characteristics affect the plasma cholesterol lowering of phytosterol/phytostanol.

    Science.gov (United States)

    Cusack, Laura Kells; Fernandez, Maria Luz; Volek, Jeff S

    2013-11-01

    Foods with added phytosterols/phytostanols (PS) are recommended to lower LDL cholesterol (LDL-c) concentrations. Manufacturers have incorporated PS into a variety of common foods. Understanding the cholesterol-lowering impact of the food matrix and the PS characteristics would maximize their success and increase the benefit to consumers. This review systematically examines whether the PS characteristics and the fatty acid composition of foods with added PS affects serum LDL-c. A total of 33 studies published between the years 1998 and 2011 inclusive of 66 individual primary variables (strata) were evaluated. The functional food matrices included margarine, mayonnaise, yogurt, milk, cheese, meat, grain, juice, and chocolate. Consistently, ≥10% reductions in LDL-c were reported when the characteristics of the food matrix included poly- and monounsaturated fatty acids known to lower LDL-c. Also, >10% mean reductions in LDL-c were reported when β-sitostanol and campestanol as well as stanol esters were used. These characteristics allow both low-fat and high-fat foods to successfully incorporate PS and significantly lower LDL-c.

  20. You are what you eat: food limitation affects reproductive fitness in a sexually cannibalistic praying mantid.

    Directory of Open Access Journals (Sweden)

    Katherine L Barry

    Full Text Available Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role. Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an

  1. You are what you eat: food limitation affects reproductive fitness in a sexually cannibalistic praying mantid.

    Science.gov (United States)

    Barry, Katherine L

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  2. How can interdisciplinarity of food, design, architecture and pedagogy affect children’s eating habits and food preferences?

    DEFF Research Database (Denmark)

    Fisker, Anna Marie; Hermanssdottir, Sunna; Rasmussen, Mai

    2012-01-01

    Abstract for the International Conference on Designing Food and Designing for Food 2012, London June 28-29, 2012......Abstract for the International Conference on Designing Food and Designing for Food 2012, London June 28-29, 2012...

  3. How can interdisciplinarity of food, design, architecture and pedagogy affect children’s eating habits and food preferences?

    DEFF Research Database (Denmark)

    Fisker, Anna Marie; Hermanssdottir, Sunna; Rasmussen, Mai

    2012-01-01

    Abstract for the International Conference on Designing Food and Designing for Food 2012, London June 28-29, 2012......Abstract for the International Conference on Designing Food and Designing for Food 2012, London June 28-29, 2012...

  4. Negative affect and neural response to palatable food intake in bulimia nervosa.

    Science.gov (United States)

    Bohon, Cara; Stice, Eric

    2012-06-01

    Binge eating is often preceded by reports of negative affect, but the mechanism by which affect may lead to binge eating is unclear. This study evaluated the effect of negative affect on neural response to anticipation and receipt of palatable food in women with bulimia nervosa (BN) versus healthy controls. We also evaluated connectivity between the amygdala and reward-related brain regions. Females with and without BN (n=26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless solution. We measured negative affect just prior to the scan. Women with BN showed a positive correlation between negative affect and activity in the putamen, caudate, and pallidum during anticipated receipt of milkshake (versus tasteless solution). There were no significant relations between negative affect and receipt of milkshake. Connectivity analyses revealed a greater relation of amygdala activity to activation in the left putamen and insula during anticipated receipt of milkshake in the bulimia group relative to the control group. The opposite pattern was found for the taste of milkshake; the control group showed a greater relation of amygdala activity to activation in the left putamen and insula in response to milkshake receipt than the bulimia group. Results show that as negative affect increases, so does responsivity of reward regions to anticipated intake of palatable food, implying that negative affect may increase the reward value of food for individuals with bulimia nervosa or that negative affect has become a conditioned cue due to a history of binge eating in a negative mood. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. ANALYSIS OF FACTORS AFFECTING FOOD SECURITY IN RURAL AND URBAN FARMING HOUSEHOLDS OF BENUE STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    Godwin Anjeinu Abu

    2016-01-01

    Full Text Available The study examined factors affecting household food security status among rural and urban farming households of Benue State, Nigeria. Purposive and simple random sampling techniques were employed to obtain a sample of 180 respondents, 90 households head each from rural and urban areas. Data were collected through structured questionnaire and analyzed using descriptive statistics, Food Security Index, Surplus/Food Insecurity Gap, Factor analysis and Probit model. Using calorie intake method, the result revealed that 53.3% and 62.2% of rural and urban households respectively were food secured. The rural and urban food secure households exceeded the recommended calorie intake by 39% and 42% respectively, while the rural and urban food insecure households fell short of recommended calorie by 24% and 26% respectively. It was also found that income of households head (p<0.10, rural households size (p<0.01, and farm size (p<0.10 had a positive impact on household food security. On the other hand, age of household head (p<0.05 and urban household size (p<0.10 had a negative relationship with household food security. Constraints such as lack of access to credits, inadequate land availability, and poverty, infertility of the soil, lack of non-farm income generating activities, storage and processing problems were identified as some of the factors militating against the achievement of food security in the study area. It was recommended that credit be provided to farming households by government to reduce the constraint of not being able to access credit facilities, the agricultural policies which aimed at promoting farmers access to land and improving farm household productivity be encouraged and that farmers be provided with informal education through extension services on nutritional awareness and non-farm income generating activities.

  6. Consequences of Food Restriction for Immune Defense, Parasite Infection, and Fitness in Monarch Butterflies.

    Science.gov (United States)

    McKay, Alexa Fritzsche; Ezenwa, Vanessa O; Altizer, Sonia

    2016-01-01

    Organisms have a finite pool of resources to allocate toward multiple competing needs, such as development, reproduction, and enemy defense. Abundant resources can support investment in multiple traits simultaneously, but limited resources might promote trade-offs between fitness-related traits and immune defenses. We asked how food restriction at both larval and adult life stages of the monarch butterfly (Danaus plexippus) affected measures of immunity, fitness, and immune-fitness interactions. We experimentally infected a subset of monarchs with a specialist protozoan parasite to determine whether parasitism further affected these relationships and whether food restriction influenced the outcome of infection. Larval food restriction reduced monarch fitness measures both within the same life stage (e.g., pupal mass) as well as later in life (e.g., adult lifespan); adult food restriction further reduced adult lifespan. Larval food restriction lowered both hemocyte concentration and phenoloxidase activity at the larval stage, and the effects of larval food restriction on phenoloxidase activity persisted when immunity was sampled at the adult stage. Adult food restriction reduced only adult phenoloxidase activity but not hemocyte concentration. Parasite spore load decreased with one measure of larval immunity, but food restriction did not increase the probability of parasite infection. Across monarchs, we found a negative relationship between larval hemocyte concentration and pupal mass, and a trade-off between adult hemocyte concentration and adult life span was evident in parasitized female monarchs. Adult life span increased with phenoloxidase activity in some subsets of monarchs. Our results emphasize that food restriction can alter fitness and immunity across multiple life stages. Understanding the consequences of resource limitation for immune defense is therefore important for predicting how increasing constraints on wildlife resources will affect fitness and

  7. Silencing of ecdysone receptor, insect intestinal mucin and sericotropin genes by bacterially produced double-stranded RNA affects larval growth and development in Plutella xylostella and Helicoverpa armigera.

    Science.gov (United States)

    Israni, B; Rajam, M V

    2017-04-01

    RNA interference mediated gene silencing, which is triggered by double-stranded RNA (dsRNA), has become a important tool for functional genomics studies in various systems, including insects. Bacterially produced dsRNA employs the use of a bacterial strain lacking in RNaseIII activity and harbouring a vector with dual T7 promoter sites, which allow the production of intact dsRNA molecules. Here, we report an assessment of the functional relevance of the ecdysone receptor, insect intestinal mucin and sericotropin genes through silencing by dsRNA in two lepidopteran insect pests, Helicoverpa armigera and Plutella xylostella, both of which cause serious crop losses. Oral feeding of dsRNA led to significant reduction in transcripts of the target insect genes, which caused significant larval mortality with various moulting anomalies and an overall developmental delay. We also found a significant decrease in reproductive potential in female moths, with a drop in egg laying and compromised egg hatching from treated larvae as compared to controls. dsRNA was stable in the insect gut and was efficiently processed into small interfering RNAs (siRNAs), thus accounting for the phenotypes observed in the present work. The study revealed the importance of these genes in core insect processes, which are essential for insect development and survival. © 2016 The Royal Entomological Society.

  8. Food intake patterns and factors affecting in preschool children in Bushehr city

    Directory of Open Access Journals (Sweden)

    Farideh Nazari

    2015-07-01

    Full Text Available Background: Numerous factors, some obvious and others subtle, determine food intake patterns in children. Likes and dislikes are established in the early years. The purpose of this study is to assess the food consumption pattern and factors affecting in preschool children in bushehr city. Materials and Methods: This is descriptive, analytical study. The total of 191 preschool children (6 years old was selected at random sampling method. Data were collected by food frequency questionnaire and were analyzed by table of serving sizes food groups for children and adolescents and by SPSS software 16. Results: Frequency Of milk consumption was 41.9% daily, 40.9% weekly, and 12.6% rarely. Frequency Of fish consumption was 1.6% daily, 71.7% weekly, and 16.8% rarely. Frequency Of chicken consumption was 1% daily, 83.4% weekly, and 9.9% rarely. Frequency Of fruit consumption was 69.6% daily, 22% weekly, and 7.3% rarely. There was significant statistical relationship between Frequency consumption Of dairy, salad, fruit , juices, chicken, egg, and fathers ‘job and fathers’ and mothers’ education level.(P<0. 05 Conclusion: It is concluded that situation of food group consumption about dairy, meats, vegetables, cereals is poor but fruit consumption was good in preschool children. Based on results we recommended planning for educational program in relation to Nutrition and food group consumption by media and in school and public centers and health centers.

  9. Eating in groups: Do multiple social influences affect intake in a fast-food restaurant?

    Science.gov (United States)

    Brindal, Emily; Wilson, Carlene; Mohr, Philip; Wittert, Gary

    2015-05-01

    This study investigated multiple social influences to determine whether they affect amount eaten at a fast-food environment. Using observational methods, data on meal duration, foods eaten and personal characteristics were collected for 157 McDonald's patrons. Analysis of covariance revealed that female diners ate less kilojoules when eating in mixed- versus same-sex groups (adjusted difference = 967 kJ, p groups compared to pairs (adjusted difference = 1067 kJ, p = .019). Influences to increase and restrict the amount eaten can operate simultaneously in an eating environment with gender a critical factor for consideration.

  10. Larval fish nutrition

    National Research Council Canada - National Science Library

    Holt, J

    2011-01-01

    ... introduction to fish micronutrient history 4.2 Micronutrients in larval feeds 4.3 Requirements versus recommendations 4.4 Vitamins 4.5 Minerals 34.6 Future challenges Section 2: Nutritional Physi...

  11. Larval Exposure to the Juvenile Hormone Analog Pyriproxyfen Disrupts Acceptance of and Social Behavior Performance in Adult Honeybees.

    Directory of Open Access Journals (Sweden)

    Julie Fourrier

    Full Text Available Juvenile hormone (JH plays an important role in honeybee development and the regulation of age-related division of labor. However, honeybees can be exposed to insect growth regulators (IGRs, such as JH analogs developed for insect pest and vector control. Although their side effects as endocrine disruptors on honeybee larval or adult stages have been studied, little is known about the subsequent effects on adults of a sublethal larval exposure. We therefore studied the impact of the JH analog pyriproxyfen on larvae and resulting adults within a colony under semi-field conditions by combining recent laboratory larval tests with chemical analysis and behavioral observations. Oral and chronic larval exposure at cumulative doses of 23 or 57 ng per larva were tested.Pyriproxyfen-treated bees emerged earlier than control bees and the highest dose led to a significant rate of malformed adults (atrophied wings. Young pyriproxyfen-treated bees were more frequently rejected by nestmates from the colony, inducing a shorter life span. This could be linked to differences in cuticular hydrocarbon (CHC profiles between control and pyriproxyfen-treated bees. Finally, pyriproxyfen-treated bees exhibited fewer social behaviors (ventilation, brood care, contacts with nestmates or food stocks than control bees.Larval exposure to sublethal doses of pyriproxyfen affected several life history traits of the honeybees. Our results especially showed changes in social integration (acceptance by nestmates and social behaviors performance that could potentially affect population growth and balance of the colony.

  12. How Emotions Expressed by Adults' Faces Affect the Desire to Eat Liked and Disliked Foods in Children Compared to Adults

    Science.gov (United States)

    Barthomeuf, Laetitia; Droit-Volet, Sylvie; Rousset, Sylvie

    2012-01-01

    The aim of this study was to determine whether or not pleasure, neutrality, and disgust expressed by eaters in photographs could affect the desire to eat food products to a greater extent in children than in adults. Children of 5 and 8 years of age, as well as adults, were presented with photographs of liked and disliked foods. These foods were…

  13. Lycopene in tomatoes: chemical and physical properties affected by food processing.

    Science.gov (United States)

    Shi, J; Le Maguer, M

    2000-01-01

    Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all

  14. Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development.

    Directory of Open Access Journals (Sweden)

    Raylea Rowbottom

    Full Text Available Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level. To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission.

  15. Air pollution affects food security in China: taking ozone as an example

    Directory of Open Access Journals (Sweden)

    Zhaozhong FENG,Xuejun LIU,Fusuo ZHANG

    2015-06-01

    Full Text Available Air pollution is becoming an increasingly important environmental concern due to its visible negative impact on human health. However, air pollution also affects agricultural crops or food security directly or indirectly, which has not so far received sufficient attention. In this overview, we take ozone (O3 as an example to analyze the principles and extent of the impact of air pollution on food security in China based on a review of the literature. Current O3 pollution shows a clear negative impact on food security, causing around a 10% yield decrease for major cereal crops according to a large number of field studies around the world. The mean yield decrease of winter wheat is predicted to be up to 20% in China, based on the projection of future ground-level O3 concentration in 2020, if no pollution control measures are implemented. Strict mitigation of NOx and VOCs (two major precursors of O3 emissions is crucial for reducing the negative impacts of ground-level O3 on food security. Breeding new crop cultivars with tolerance to high ground-level O3 should receive serious consideration in future research programs. In addition, integrated soil-crop system management will be an important option to mitigate the negative effects of elevated ground-level O3 on cereal crop production and food quality.

  16. Rethinking Food: How United States Agriculture Production Affects Security Policy and Global Markets

    Science.gov (United States)

    2014-06-13

    businesses. In 1978, USAID introduced Policy Directive 71, which affected palm oil , citrus and sugar projects, and related products. This internal...Economic Coordination and Development PD Policy Directive PL-480 Public Law 480 SALT Strategic Arms Limitation Talks RTAA Reciprocal Trade Agreement...field agents that assist in implementing broad US policy statements or legislation (Becker 2014). PL-480– Public Law 480, or Food for Peace. This law

  17. Familiarity with and affective responses to foods in 8-11-year-old children. The role of food neophobia and parental education.

    Science.gov (United States)

    Mustonen, Sari; Oerlemans, Patty; Tuorila, Hely

    2012-06-01

    The present study investigated whether the familiarity with and affective responses to foods are predicted by the individual trait food neophobia and by parental education in school children. The cross-sectional data collection involved children (N=208, 8- and 11-year-old) from Helsinki, and their parents. A questionnaire assessing children's food neophobia with Food Neophobia Scale (FNS), and familiarity with and affective responses to 36 foods was completed by parents. Children with low FNS were familiar with a larger number of foods than those with high FNS. High FNS was associated with low pleasantness assessment of most food groups, including cheese, fruit/vegetables, fish, starch/cereals, and ethnic/exotic. Children of well educated parents had tasted a larger number of foods, thus displaying lower behavioral neophobia, and had lower FNS scores than children of less educated parents. Both low FNS scores and high parental education predicted the number of tasted foods. Parental education was not associated with pleasantness ratings (exception: cheese). To conclude, high food neophobia lowers the pleasantness ratings of foods, and parental education moderates behavioral neophobia.

  18. Affective priming as an indirect measure of food preferences acquired through odor conditioning.

    Science.gov (United States)

    Hermans, Dirk; Baeyens, Frank; Lamote, Sabine; Spruyt, Adriaan; Eelen, Paul

    2005-01-01

    The present study aimed at investigating affective priming for originally neutral food stimuli that recently acquired their affective meaning through odor conditioning. In a first phase, pictures of different brands of yogurts (CSs) were contingently presented with a positive or negative odor (US). In a subsequent phase, the yogurt CSs were used as primes in an affective priming procedure. Rating data showed that the acquisition procedure resulted in a reliable evaluative learning effect. This could be corroborated by the results of the priming task. Participants responded faster to positive target words and made fewer errors when they were preceded by a CS that had been associated with a positive odor, as compared to a CS that was associated with a negative odor. A reversed pattern was present for negative targets. Based on these findings, it is suggested that affective priming might be used as a demand-free measure of evaluative learning.

  19. Food availability and maternal immunization affect transfer and persistence of maternal antibodies in nestling pigeons.

    Directory of Open Access Journals (Sweden)

    Ahmad Ismail

    Full Text Available The ability of mothers to transfer antibodies (Abs to their young and the temporal persistence of maternal Abs in offspring constitute important life-history traits that can impact the evolution of host-parasite interactions. Here, we examined the effects of food availability and parental immunization on the transfer and persistence of maternal antibodies in nestling pigeons (Columba livia. This species can transmit maternal Abs to offspring before hatching through the egg yolk and potentially after hatching through crop milk. However, the role of this postnatal substance in immunity remains elusive. We used a full cross-fostering design to disentangle the effects of food limitation and parental immunization both before and after hatching on the levels and persistence of maternal Abs in chicks. Parents were immunized via injection with keyhole limpet hemocyanin antigens. Using an immunoassay that specifically detected the IgY antibodies that are known to be transmitted via the yolk, we found that the levels of anti-KLH Abs in newly hatched chicks were positively correlated with the levels of anti-KLH Abs in the blood of their biological mothers. However, this correlation was not present between chicks and their foster parents, suggesting limited IgY transfer via crop milk to the chick's bloodstream. Interestingly, biological mothers subjected to food limitation during egg laying transferred significantly fewer specific maternal Abs, which suggests that the transfer of antibodies might be costly for them. In addition, the persistence of maternal Abs in a chick's bloodstream was not affected by food limitation or the foster parents' anti-KLH Ab levels; it was only affected by the initial level of maternal anti-KLH Abs that were present in newly hatched chicks. These results suggest that the maternal transfer of Abs could be costly but that their persistence in an offspring's bloodstream may not necessarily be affected by environmental conditions.

  20. Bioecology of Stenoma catenifer (Lepidoptera: Elachistidae) and associated larval parasitoids reared from Hass avocados in Guatemala.

    Science.gov (United States)

    Hoddle, Mark S; Hoddle, Christina D

    2008-06-01

    A 10-wk study of the avocado seed-feeding moth Stenoma catenifer Walsingham (Lepidoptera: Elachistidae), was conducted in a commercial 'Hass' avocado (Persea americana Miller [Lauraceae]) orchard in Guatemala. Up to 45% of fruit in the orchard were damaged by larval S. catenifer. Larval-to-adult survivorship for 1,881 S. catenifer larvae in Hass fruit was 37%, and adult sex ratio was 51% female. Four species of larval parasitoid were reared from field-collected S. catenifer larvae. The most common parasitoid reared was a gregarious Apanteles sp., which parasitized 53% of larvae and produced on average eight to nine cocoons per host. Apanteles sp. sex ratio was 47% female and 87% of parasitoids emerged successfully from cocoons. Apanteles sp. longevity was approximately equal to 1.5 d in the absence of food, and when provisioned with honey, parasitoids survived for 5-7 d. The mean number of cocoons produced by Apanteles sp. per host, and larval parasitism rates were not significantly affected by the number of S. catenifer larvae inhabiting seeds. Oviposition studies conducted with S. catenifer in the laboratory indicated that this moth lays significantly more eggs on the branch to which the fruit pedicel is attached than on avocado fruit. When given a choice between Hass and non-Hass avocados, S. catenifer lays up to 2.69 times more eggs on Hass.

  1. Swimming speed of larval snail does not correlate with size and ciliary beat frequency.

    Science.gov (United States)

    Chan, Kit Yu Karen; Jiang, Houshuo; Padilla, Dianna K

    2013-01-01

    Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8-4 body lengths s(-1)) that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton.

  2. Swimming speed of larval snail does not correlate with size and ciliary beat frequency.

    Directory of Open Access Journals (Sweden)

    Kit Yu Karen Chan

    Full Text Available Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8-4 body lengths s(-1 that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton.

  3. Swimming Speed of Larval Snail Does Not Correlate with Size and Ciliary Beat Frequency

    Science.gov (United States)

    Chan, Kit Yu Karen; Jiang, Houshuo; Padilla, Dianna K.

    2013-01-01

    Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8–4 body lengths s−1) that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton. PMID:24367554

  4. Do human activities influence survival and orientation abilities of larval fishes in the ocean?

    Science.gov (United States)

    Siebeck, Ulrike E; O'Connor, Jack; Braun, Christoph; Leis, Jeffrey M

    2015-01-01

    The larval stages of most marine fishes spend days to weeks in the pelagic environment, where they must find food and avoid predators in order to survive. Some fish only spend part of their life history in the pelagic environment before returning to their adult habitat, for example, a coral reef. The sensory systems of larval fish develop rapidly during the first few days of their lives, and here we concentrate on the various sensory cues the fish have available to them for survival in the pelagic environment. We focus on the larvae of reef fishes because most is known about them. We also review the major threats caused by human activities that have been identified to have worldwide impact and evaluate how these threats may impact larval-fish survival and orientation abilities. Many human activities negatively affect larval-fish sensory systems or the cues the fish need to detect. Ultimately, this could lead to decreased numbers of larvae surviving to settlement, and, therefore, to decreased abundance of adult fishes. Although we focus on species wherein the larvae and adults occupy different habitats (pelagic and demersal, respectively), it is important to acknowledge that the potential anthropogenic effects we identify may also apply to larvae of species like tuna and herring, where both larvae and adults are pelagic. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  5. An (un)healthy poster: When environmental cues affect consumers' food choices at vending machines.

    Science.gov (United States)

    Stöckli, Sabrina; Stämpfli, Aline E; Messner, Claude; Brunner, Thomas A

    2016-01-01

    Environmental cues can affect food decisions. There is growing evidence that environmental cues influence how much one consumes. This article demonstrates that environmental cues can similarly impact the healthiness of consumers' food choices. Two field studies examined this effect with consumers of vending machine foods who were exposed to different posters. In field study 1, consumers with a health-evoking nature poster compared to a pleasure-evoking fun fair poster or no poster in their visual sight were more likely to opt for healthy snacks. Consumers were also more likely to buy healthy snacks when primed by an activity poster than when exposed to the fun fair poster. In field study 2, this consumer pattern recurred with a poster of skinny Giacometti sculptures. Overall, the results extend the mainly laboratory-based evidence by demonstrating the health-relevant impact of environmental cues on food decisions in the field. Results are discussed in light of priming literature emphasizing the relevance of preexisting associations, mental concepts and goals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Lescord, Gretchen L., E-mail: glescord@gmail.com [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kidd, Karen A. [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kirk, Jane L. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada); O' Driscoll, Nelson J. [Acadia University, 15 University Ave, Wolfville, NS B4P 2R6 (Canada); Wang, Xiaowa; Muir, Derek C.G. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada)

    2015-03-15

    In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ{sup 13}C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ{sup 15}N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota. - Highlights: • Mercury (Hg) in Arctic char and invertebrates

  7. Evaluating sampling strategies for larval cisco (Coregonus artedi)

    Science.gov (United States)

    Myers, J.T.; Stockwell, J.D.; Yule, D.L.; Black, J.A.

    2008-01-01

    To improve our ability to assess larval cisco (Coregonus artedi) populations in Lake Superior, we conducted a study to compare several sampling strategies. First, we compared density estimates of larval cisco concurrently captured in surface waters with a 2 x 1-m paired neuston net and a 0.5-m (diameter) conical net. Density estimates obtained from the two gear types were not significantly different, suggesting that the conical net is a reasonable alternative to the more cumbersome and costly neuston net. Next, we assessed the effect of tow pattern (sinusoidal versus straight tows) to examine if propeller wash affected larval density. We found no effect of propeller wash on the catchability of larval cisco. Given the availability of global positioning systems, we recommend sampling larval cisco using straight tows to simplify protocols and facilitate straightforward measurements of volume filtered. Finally, we investigated potential trends in larval cisco density estimates by sampling four time periods during the light period of a day at individual sites. Our results indicate no significant trends in larval density estimates during the day. We conclude estimates of larval cisco density across space are not confounded by time at a daily timescale. Well-designed, cost effective surveys of larval cisco abundance will help to further our understanding of this important Great Lakes forage species.

  8. Factors Affecting Project Governance Of Arusha Archdiocesan Food Security And Livelihood Project In Monduli District Tanzania.

    Directory of Open Access Journals (Sweden)

    Kisame Deogratious

    2015-06-01

    Full Text Available Abstract This research project dealt with the factors affecting governance of Food security and livelihood projects a case study of the Food security and livelihood project that was implemented by AAIDRO in Monduli district and included 60 respondents all together. The specific objectives of this study intended to access the Leadership styles that are being used in project governance. The findings of the study indicated that 91.7 of the respondents were in favor of their leaders project governance styles it was portrayed that participative leadership style was being used by the leaders for project governance. Based on a sample of 60 project members this study had confirmed that a project leaders leadership roles like mentor facilitator innovator and coordinator are important in influencing project governance effectiveness which includes team mission goal achievement and empowerment open and honest communication

  9. Adaptation to larval crowding in Drosophila ananassae and Drosophila nasuta nasuta : increased larval competitive ability without increased larval feeding rate

    Indian Academy of Sciences (India)

    ARCHANA NAGARAJAN; SHARMILA BHARATHI NATARAJAN; MOHAN JAYARAM; ANANDA THAMMANNA; SUDARSHAN CHARI; JOY BOSE; SHREYAS V. JOIS; AMITABH JOSHI

    2016-06-01

    The standard view of adaptation to larval crowding in fruitflies, built on results from 25 years of multiple experimental evo-lution studies onDrosophila melanogaster , was that enhanced competitive ability evolves primarily through increased larvalfeeding and foraging rate, and increased larval tolerance to nitrogenous wastes, at the cost of efficiency of food conversion tobiomass. These results were at odds from the predictions of classicalK -selection theory, notably the expectation that selec-tion at high density should result in the increase of efficiency of conversion of food to biomass, and were better interpretedthrough the lens of α -selection. We show here that populations ofD. ananassaeandD. n. nasutasubjected to extreme larvalcrowding evolve greater competitive ability and pre-adult survivorship at high density, primarily through a combination ofreduced larval duration, faster attainment of minimum critical size for pupation, greater time efficiency of food conversion tobiomass and increased pupation height, with a relatively small role of increased urea/ammonia tolerance, if at all. This is avery different suite of traits than that seen to evolve under similar selection inD .melanogaster ,andseemstobeclosertotheexpectations from the canonical theory ofK -selection. We also discuss possible reasons for these differences in results acrossthe three species. Overall, the results reinforce the view that our understanding of the evolution of competitive ability in fruit-flies needs to be more nuanced than before, with an appreciation that there may be multiple evolutionary routes through whichhigher competitive ability can be attained.

  10. Fruit-related terms and images on food packages and advertisements affect children's perceptions of foods' fruit content.

    Science.gov (United States)

    Heller, Rebecca; Martin-Biggers, Jennifer; Berhaupt-Glickstein, Amanda; Quick, Virginia; Byrd-Bredbenner, Carol

    2015-10-01

    To determine whether food label information and advertisements for foods containing no fruit cause children to have a false impression of the foods' fruit content. In the food label condition, a trained researcher showed each child sixteen different food label photographs depicting front-of-food label packages that varied with regard to fruit content (i.e. real fruit v. sham fruit) and label elements. In the food advertisement condition, children viewed sixteen, 30 s television food advertisements with similar fruit content and label elements as in the food label condition. After viewing each food label and advertisement, children responded to the question 'Did they use fruit to make this?' with responses of yes, no or don't know. Schools, day-care centres, after-school programmes and other community groups. Children aged 4-7 years. In the food label condition, χ 2 analysis of within fruit content variation differences indicated children (n 58; mean age 4·2 years) were significantly more accurate in identifying real fruit foods as the label's informational load increased and were least accurate when neither a fruit name nor an image was on the label. Children (n 49; mean age 5·4 years) in the food advertisement condition were more likely to identify real fruit foods when advertisements had fruit images compared with when no image was included, while fruit images in advertisements for sham fruit foods significantly reduced accuracy of responses. Findings suggest that labels and advertisements for sham fruit foods mislead children with regard to the food's real fruit content.

  11. The 2008 food price crisis negatively affected household food security and dietary diversity in urban Burkina Faso.

    Science.gov (United States)

    Martin-Prevel, Yves; Becquey, Elodie; Tapsoba, Sylvestre; Castan, Florence; Coulibaly, Dramane; Fortin, Sonia; Zoungrana, Mahama; Lange, Matthias; Delpeuch, Francis; Savy, Mathilde

    2012-09-01

    Although the 2008 food price crisis presumably plunged millions of households into poverty and food insecurity, the real impact of the crisis has rarely been documented using field data. Our objective was to assess the consequences of this crisis for household food insecurity and dietary diversity in urban Burkina Faso. Two cross-sectional surveys were conducted among randomly selected households in Ouagadougou in July 2007 (n = 3017) and July 2008 (n = 3002). At each round, food insecurity assessed by the Household Food Insecurity Access Scale (HFIAS), the Dietary Diversity Score of an index-member of the household (IDDS = number of food groups consumed in the last 24 h), and food expenditure were collected. Food prices of the 17 most frequently consumed food items were recorded throughout the study area. Food prices at local markets increased considerably between 2007 and 2008, especially those of fish (113%), cereals (53%), and vegetable oil (44%), increasing the household monthly food expenditure by 18%. Thirty-three percent of households were food secure in 2007 and 22% in 2008 (P = 0.02). Individuals consumed fewer fruits and vegetables, dairy products, and meat/poultry in 2008 than in 2007 (mean IDDS = 5.7 ± 1.7 food groups in 2007 vs. 5.2 ± 1.5 in 2008; P crisis.

  12. Variability in the contents of pork meat nutrients and how it may affect food composition databases.

    Science.gov (United States)

    Reig, Milagro; Aristoy, M-Concepción; Toldrá, Fidel

    2013-10-01

    Pork meat is generally recognised as a food with relevant nutritional properties because of its content in high biological value proteins, group B vitamins, minerals especially heme iron, trace elements and other bioactive compounds. But pork meat also contributes to the intake of fat, saturated fatty acids, cholesterol, and other substances that, in inappropriate amounts, may result in negative physiologically effects. However, there are relevant factors affecting the content of many of these substances and somehow such variability should be taken into consideration. So, genetics, age and even type of muscle have a relevant influence on the amount of fat and the contents in heme iron. Also the composition in fatty acids of triacylglycerols is very sensitive to the contents of cereals in the feed; for instance, polyunsaturated fatty acids may range from 10% to 22% in pork meat. The content of other nutrients, like vitamins E and A, are also depending on the type of feed. Some bioactive substances like coenzyme Q10, taurine, glutamine, creatine, creatinine, carnosine and anserine show a large dependence on the type of muscle. This manuscript describes the main factors affecting the composition of pork meat nutrients and how these changes may affect the general food composition databases.

  13. Factors Affecting the Adoption of Genetically Modified Animals in the Food and Pharmaceutical Chains

    Directory of Open Access Journals (Sweden)

    Cristina Mora

    2013-03-01

    Full Text Available The production of genetically modified (GM animals is an emerging technique that could potentially impact the livestock and pharmaceutical industries. Currently, food products derived from GM animals have not yet entered the market whilst two pharmaceutical products have. The objective of this paper is twofold: first it aims to explore the socio-economic drivers affecting the use of GM animals and, second, to review the risks and benefits from the point of view of the life sciences. A scoping study was conducted to assess research relevant to understanding the main drivers influencing the adoption of GM applications and their potential risks and benefits. Public and producers’ acceptance, public policies, human health, animal welfare, environmental impact and sustainability are considered as the main factors affecting the application of GM animal techniques in livestock and pharmaceutical chains.

  14. Multidimensional Evaluation of Endogenous and Health Factors Affecting Food Preferences, Taste and Smell Perception.

    Science.gov (United States)

    Guido, D; Perna, S; Carrai, M; Barale, R; Grassi, M; Rondanelli, M

    2016-01-01

    This study, by taking a holistic approach, investigates the relationships between taste, smell sensitivity and food preference with prognostic (endogenous and health) factors including age, gender, genetic taste markers, body mass, cigarette smoking, and number of drugs used. Cross sectional study. Northern Italy. 203 healthy subjects (160 women/43 men; mean age: 58.2±19.8 years) were examined. Individual taste sensitivity was determined by saccharose, sodium chloride, acetic acid and caffeine solutions and by 6-n-propylthiouracil (PROP) responsiveness test. Olfactory sensitivity has been assessed by «Sniffin' Sticks». Four tag Single nucleotide polymorphisms (SNPs) in regions of interest were genotyped. Factor analysis and multivariate regression were performed for scaling food preferences and screening prognostic factors, respectively. Increasing age is associated with decreased responsiveness to NaCl (P=0.001), sweet solutions (P=0.044), and smell perception (Pmore than younger. Regarding number of drugs taken, there is a significant negative effect on smell perception (Peffect was shown, on sweet perception (P=0.006). Variation in taste receptor genes can give rise to differential perception of sweet, acid and bitter tastes. No effect of gender and smoking was observed. Our study suggested that age, genetic markers, BMI and drugs use are the factors which affect taste and smell perception and food preferences.

  15. Ultrasonic excitation affects friction interactions between food materials and cutting tools.

    Science.gov (United States)

    Schneider, Yvonne; Zahn, Susann; Schindler, Claudia; Rohm, Harald

    2009-06-01

    In the food industry, ultrasonic cutting is used to improve separation by a reduction of the cutting force. This reduction can be attributed to the modification of tool-workpiece interactions at the cutting edge and along the tool flanks because of the superposition of the cutting movement with ultrasonic vibration of the cutting tool. In this study, model experiments were used to analyze friction between the flanks of a cutting tool and the material to be cut. Friction force at a commercial cutting sonotrode was quantified using combined cutting-friction experiments, and sliding friction tests were carried out by adapting a standard draw-off assembly and using an ultrasonic welding sonotrode as sliding surface. The impact of material parameters, ultrasonic amplitude, and the texture of the contacting food surface on friction force was investigated. The results show that ultrasonic vibration significantly reduces the sliding friction force. While the amplitude showed no influence within the tested range, the texture of the contact surface of the food affects the intensity of ultrasonic transportation effects. These effects are a result of mechanical interactions and of changes in material properties of the contact layer, which are induced by the deformation of contact points, friction heating and absorption heating because of the dissipation of mechanical vibration energy.

  16. Disruption of the lower food web in Lake Ontario: Did it affect alewife growth or condition?

    Science.gov (United States)

    O'Gorman, R.; Prindle, S.E.; Lantry, J.R.; Lantry, B.F.

    2008-01-01

    From the early 1980s to the late 1990s, a succession of non-native invertebrates colonized Lake Ontario and the suite of consequences caused by their colonization became known as "food web disruption". For example, the native burrowing amphipod Diporeia spp., a key link in the profundal food web, declined to near absence, exotic predaceous cladocerans with long spines proliferated, altering the zooplankton community, and depth distributions of fishes shifted. These changes had the potential to affect growth and condition of planktivorous alewife Alosa pseudoharengus, the most abundant fish in the lake. To determine if food web disruption affected alewife, we used change-point analysis to examine alewife growth and adult alewife condition during 1976-2006 and analysis-of-variance to determine if values between change points differed significantly. There were no change points in growth during the first year of life. Of three change points in growth during the second year of life, one coincided with the shift in springtime distribution of alewife to deeper water but it was not associated with a significant change in growth. After the second year of life, no change points in growth were evident, although growth in the third year of life spiked in those years when Bythotrephes, the largest of the exotic cladocerans, was abundant suggesting that it was a profitable prey item for age-2 fish. We detected two change points in condition of adult alewife in fall, but the first occurred in 1981, well before disruption began. A second change point occurred in 2003, well after disruption began. After the springtime distribution of alewife shifted deeper during 1992-1994, growth in the first two years of life became more variable, and growth in years of life two and older became correlated (P < 0.05). In conclusion, food web disruption had no negative affect on growth and condition of alewife in Lake Ontario although it appears to have resulted in growth in the first two years of

  17. Food Deprivation Affects the miRNome in the Lactating Goat Mammary Gland.

    Directory of Open Access Journals (Sweden)

    Lenha Mobuchon

    Full Text Available Nutrition affects milk composition thus influencing its nutritional properties. Nutrition also modifies the expression of mammary genes, whose regulation is not fully understood. MicroRNAs (miRNA are small non coding RNA which are important post-transcriptional regulators of gene expression by targeting messenger RNAs. Our goal was to characterize miRNA whose expression is regulated by nutrition in the lactating goat mammary gland, which may provide clues to deciphering regulations of the biosynthesis and secretion of milk components.Using high-throughput sequencing technology, miRNomes of the lactating mammary gland were established from lactating goats fed ad libitum or deprived of food for 48 h affecting milk production and composition. High throughput miRNA sequencing revealed 30 miRNA with an expression potentially modulated by food deprivation; 16 were down-regulated and 14 were up-regulated. Diana-microT predictive tools suggested a potential role for several nutriregulated miRNA in lipid metabolism. Among the putative targets, 19 were previously identified as differently expressed genes (DEG. The functions of these 19 DEG revealed, notably, their involvement in tissue remodelling.In conclusion, this study offers the first evidence of nutriregulated miRNA in the ruminant mammary gland. Characterization of these 30 miRNA could contribute to a clearer understanding of gene regulation in the mammary gland in response to nutrition.

  18. Food can lift mood by affecting mood-regulating neurocircuits via a serotonergic mechanism.

    Science.gov (United States)

    Kroes, Marijn C W; van Wingen, Guido A; Wittwer, Jonas; Mohajeri, M Hasan; Kloek, Joris; Fernández, Guillén

    2014-01-01

    It is commonly assumed that food can affect mood. One prevalent notion is that food containing tryptophan increases serotonin levels in the brain and alters neural processing in mood-regulating neurocircuits. However, tryptophan competes with other long-neutral-amino-acids (LNAA) for transport across the blood-brain-barrier, a limitation that can be mitigated by increasing the tryptophan/LNAA ratio. We therefore tested in a double-blind, placebo-controlled crossover study (N=32) whether a drink with a favourable tryptophan/LNAA ratio improves mood and modulates specific brain processes as assessed by functional magnetic resonance imaging (fMRI). We show that one serving of this drink increases the tryptophan/LNAA ratio in blood plasma, lifts mood in healthy young women and alters task-specific and resting-state processing in brain regions implicated in mood regulation. Specifically, Test-drink consumption reduced neural responses of the dorsal caudate nucleus during reward anticipation, increased neural responses in the dorsal cingulate cortex during fear processing, and increased ventromedial prefrontal-lateral prefrontal connectivity under resting-state conditions. Our results suggest that increasing tryptophan/LNAA ratios can lift mood by affecting mood-regulating neurocircuits.

  19. Attitudinal Factors Affecting Viral Advertising Pass-On Behaviour of Online Consumers in Food Industry

    Science.gov (United States)

    Mohd Salleh, Nurhidayah; Ariff, Mohd Shoki Md; Zakuan, Norhayati; Sulaiman, Zuraidah; Zameri Mat Saman, Muhamad

    2016-05-01

    The increase number of active users of social media, especially Facebook, stimulates viral advertising behaviour among them, thus attracting e-marketers to focus on viral advertising in promoting their products. In global market, use of Facebook platform indicated that food services/restaurant of food industry is ranked number 11 with 18.8% users’ response rate within the platform. This development calls for e-marketers in Malaysia to use Facebook as their viral advertising channel. Attitudinal factors affecting the viral advertising pass-on behaviour (VAPB) especially among members of social media is of interest to many researchers. The typical attitudinal factors used were attitude toward social media (ATSM), attitude toward advertising in social media (AASM) and attitude toward advertising in general (AAIG). Attitude toward advertised brand (ATAB) is important in fast food industry because users of social media tend to share their experience about tastes and features of the food. However, ATAB is less emphasized in the conceptual model between attitudinal factors and VAPB. These four factors of consumer attitude served as independent variables in the conceptual model of this study and their effect on viral advertising pass-on behaviour among members of Domino's Pizza Malaysia Facebook page was examined. Online survey using a set of questionnaire which was sent to the members of this group via private message was employed. A total of 254 sets of usable questionnaires were collected from the respondents. All the attitudinal factors, except for AASM, were found to have positive and significant effect on VAPB. AAIG exerted the strongest effect on VAPB. Therefore, e-marketers should emphasize on developing a favourable attitude toward advertising in general among members of a social media to get them involve in viral advertising. In addition, instilling a favourable attitude towards advertised brand is also vital as it influences the members to viral the brand

  20. Assessment of intake of iron and nutrients that affect bioavailability of daily food rations of girls

    Directory of Open Access Journals (Sweden)

    Anna Broniecka

    2014-06-01

    Full Text Available INTRODUCTION AND AIM In a human body iron occurs at a level of 3 to 5 g, 60-70 % of which are in hemoglobin, ca. 10% in myoglobin, and ca. 3% are accumulated in enzymes of cellular respiration or enzymes degrading toxic hydrogen peroxide. The other part of iron is accumulated in liver, spleen, kidneys and bone marrow. The dietary deficiency of iron appears at its insufficient level in a diet and at impaired absorption of iron ions present in food products by a body. Groups at an especially high risk of iron deficiencies include, among others, menstruating girls in the pubescence period and women with heavy and irregular menstruations, as well as vegetarians and patients with chronic enteritis. The aim of this study was to evaluate the intake of iron and nutrients that affect its bioavailability from daily food rations of girls. MATERIAL AND METHODS The study included 159 girls aged 17-18, students of high schools in the city of Wroclaw. The study was conducted between November 2010 and ay 2011. Girls were divided into 3 subgroups according to the BMI score. Girls’ diets were analyzed with the method of a direct interview of the last 24 hours before the test and the interview was repeated seven times. RESULTS The present study demonstrated that the intake of iron from food rations of almost all the girls surveyed was below the requirements defined for this age group. Statistically significant differences were noted in the intake of energy and nutrients among the three distinguished subgroups of girls. CONCLUSIONS Food rations of the surveyed girls were characterized by a low, compared to dietary allowances, calorific value, which resulted in deficiencies of nutrients increasing iron bioavailability.

  1. Biofilm Matrix Composition Affects the Susceptibility of Food Associated Staphylococci to Cleaning and Disinfection Agents

    Science.gov (United States)

    Fagerlund, Annette; Langsrud, Solveig; Heir, Even; Mikkelsen, Maria I.; Møretrø, Trond

    2016-01-01

    Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride (BC)-containing disinfectants is due to biofilm formation, matrix composition, or BC efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2), S. cohnii, S. epidermidis, S. lentus (2), and S. saprophyticus (2). The eight biofilm producing strains were characterized using whole genome sequencing. Three of these strains contained the ica operon responsible for production of a polysaccharide matrix, and formed a biofilm which was detached upon exposure to the polysaccharide degrading enzyme Dispersin B, but not Proteinase K or trypsin. These strains were more tolerant to the lethal effect of BC both in suspension and biofilm than the remaining five biofilm producing strains. The five BC susceptible strains were characterized by lack of the ica operon, and their biofilms were detached by Proteinase K or trypsin, but not Dispersin B, indicating that proteins were major structural components of their biofilm matrix. Several novel cell wall anchored repeat domain proteins with domain structures similar to that of MSCRAMM adhesins were identified in the genomes of these strains, potentially representing novel mechanisms of ica-independent biofilm accumulation. Biofilms from all strains showed similar levels of detachment after exposure to alkaline chlorine, which is used for cleaning in the food industry. Strains with qac genes encoding BC efflux pumps could grow at higher concentrations of BC than strains without these genes, but no differences were observed at biocidal concentrations. In conclusion, the biofilm matrix of food associated staphylococci varies with respect to protein or polysaccharide nature, and this may affect the sensitivity toward a commonly used disinfectant. PMID:27375578

  2. Biofilm matrix composition affects the susceptibility of food associated staphylococci to cleaning and disinfection agents

    Directory of Open Access Journals (Sweden)

    Annette eFagerlund

    2016-06-01

    Full Text Available Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride-containing disinfectants is due to biofilm formation, matrix composition or benzalkonium chloride efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2, S. cohnii, S. epidermidis, S. lentus (2, and S. saprophyticus (2. The eight biofilm producing strains were characterized using whole genome sequencing. Three of these strains contained the ica operon responsible for production of a polysaccharide matrix, and formed a biofilm which was detached upon exposure to the polysaccharide degrading enzyme Dispersin B, but not Proteinase K or trypsin. These strains were more tolerant to the lethal effect of benzalkonium chloride both in suspension and biofilm than the remaining five biofilm producing strains. The five benzalkonium chloride susceptible strains were characterized by lack of the ica operon, and their biofilms were detached by Proteinase K or trypsin, but not Dispersin B, indicating that proteins were major structural components of their biofilm matrix. Several novel cell wall anchored repeat domain proteins with domain structures similar to that of MSCRAMM adhesins were identified in the genomes of these strains, potentially representing novel mechanisms of ica-independent biofilm accumulation. Biofilms from all strains showed similar levels of detachment after exposure to alkaline chlorine, which is used for cleaning in the food industry. Strains with qac genes encoding benzalkonium chloride efflux pumps could grow at higher concentrations of benzalkonium chloride than strains without these genes, but no differences were observed at biocidal concentrations. In conclusion, the biofilm matrix of food associated staphylococci varies with respect to protein or

  3. Food chain transport of nanoparticles affects behaviour and fat metabolism in fish.

    Directory of Open Access Journals (Sweden)

    Tommy Cedervall

    Full Text Available Nano-sized (10(-9-10(-7 m particles offer many technical and biomedical advances over the bulk material. The use of nanoparticles in cosmetics, detergents, food and other commercial products is rapidly increasing despite little knowledge of their effect on organism metabolism. We show here that commercially manufactured polystyrene nanoparticles, transported through an aquatic food chain from algae, through zooplankton to fish, affect lipid metabolism and behaviour of the top consumer. At least three independent metabolic parameters differed between control and test fish: the weight loss, the triglycerides∶cholesterol ratio in blood serum, and the distribution of cholesterol between muscle and liver. Moreover, we demonstrate that nanoparticles bind to apolipoprotein A-I in fish serum in-vitro, thereby restraining them from properly utilising their fat reserves if absorbed through ingestion. In addition to the metabolic effects, we show that consumption of nanoparticle-containing zooplankton affects the feeding behaviour of the fish. The time it took the fish to consume 95% of the food presented to them was more than doubled for nanoparticle-exposed compared to control fish. Since many nano-sized products will, through the sewage system, end up in freshwater and marine habitats, our study provides a potential bioassay for testing new nano-sized material before manufacturing. In conclusion, our study shows that from knowledge of the molecular composition of the protein corona around nanoparticles it is possible to make a testable molecular hypothesis and bioassay of the potential biological risks of a defined nanoparticle at the organism and ecosystem level.

  4. Larval exposure to 4-nonylphenol and 17β-estradiol affects physiological and behavioral development of seawater adaptation in Atlantic salmon smolts

    Science.gov (United States)

    Lerner, Darrren T.; Bjornsson, Bjorn Thrandur; McCormick, Stephen D.

    2007-01-01

    Population declines of anadromous salmonids are attributed to anthropogenic disturbances including dams, commercial and recreational fisheries, and pollutants, such as estrogenic compounds. Nonylphenol (NP), a xenoestrogen, is widespread in the aquatic environment due to its use in agricultural, industrial, and household products. We exposed Atlantic salmon yolk-sac larvae to waterborne 10 or 100 μg L-1 NP (NP-L or NP-H, respectively), 2 μg L-1 17β-estradiol (E2), or vehicle, for 21 days to investigate their effects on smolt physiology and behavior 1 year later. NP-H caused approximately 50% mortality during exposure, 30 days after exposure, and 60 days after exposure. Mortality rates of NP-L and E2 fish were not affected until 60 days after treatment, when they were 4-fold greater than those of controls. Treatment with NP-L or E2 as yolk-sac larvae decreased gill sodium-potassium-activated adenosine triphosphatase (Na+,K+-ATPase) activity and seawater (SW) tolerance during smolt development, 1 year after exposure. Exposure to NP-L and E2 resulted in a latency to enter SW and reduced preference for SW approximately 2- and 5-fold, respectively. NP-L-exposed fish had 20% lower plasma insulin-like growth factor I (IGF-I) levels and 35% lower plasma triiodothyronine (T3). Plasma growth hormone and thyroxine (T4) were unaffected. Exposure to E2 did not affect plasma levels of IGF-I, GH, T3, or T4. Both treatment groups exhibited increased plasma cortisol and decreased osmoregulatory capacity in response to a handling stressor. These results suggest that early exposure to environmentally relevant concentrations of NP, and other estrogenic compounds, can cause direct and delayed mortalities and that this exposure can have long term, “organizational” effects on life-history events in salmonids.

  5. Larval exposure to 4-nonylphenol and 17beta-estradiol affects physiological and behavioral development of seawater adaptation in Atlantic salmon smolts.

    Science.gov (United States)

    Lerner, Darren T; Björnsson, Björn Thrandur; McCormick, Stephen D

    2007-06-15

    Population declines of anadromous salmonids are attributed to anthropogenic disturbances including dams, commercial and recreational fisheries, and pollutants, such as estrogenic compounds. Nonylphenol (NP), a xenoestrogen, is widespread in the aquatic environment due to its use in agricultural, industrial, and household products. We exposed Atlantic salmon yolk-sac larvae to waterborne 10 or 100 microg L(-1) NP (NP-L or NP-H, respectively), 2 microg L(-1) 17beta-estradiol (E2), or vehicle, for 21 days to investigate their effects on smolt physiology and behavior 1 year later. NP-H caused approximately 50% mortality during exposure, 30 days after exposure, and 60 days after exposure. Mortality rates of NP-L and E2 fish were not affected until 60 days after treatment, when they were 4-fold greater than those of controls. Treatment with NP-L or E2 as yolk-sac larvae decreased gill sodium-potassium-activated adenosine triphosphatase (Na+,K(+)-ATPase) activity and seawater (SW) tolerance during smolt development, 1 year after exposure. Exposure to NP-L and E2 resulted in a latency to enter SW and reduced preference for SW approximately 2- and 5-fold, respectively. NP-L-exposed fish had 20% lower plasma insulin-like growth factor I (IGF-I) levels and 35% lower plasma triiodothyronine (T3). Plasma growth hormone and thyroxine (T4) were unaffected. Exposure to E2 did not affect plasma levels of IGF-I, GH, T3, or T4. Both treatment groups exhibited increased plasma cortisol and decreased osmoregulatory capacity in response to a handling stressor. These results suggest that early exposure to environmentally relevant concentrations of NP, and other estrogenic compounds, can cause direct and delayed mortalities and that this exposure can have long-term, "organizational" effects on life-history events in salmonids.

  6. Can Food Stamps Do More to Improve Food Choices? An Economic Perspective--Higher Cost of Food in Some Areas May Affect Food Stamp Households' Ability To Make Healthy Food Choices

    OpenAIRE

    Nord, Mark; Hopwood, Heather

    2007-01-01

    The cost of “enough food,” estimated from the amount that low- and medium-income households in a geographic area report needing to spend to just meet their food needs, differs substantially across States and among metropolitan areas. In areas with high food costs, many food-stamp recipients are likely to have inadequate food resources to support healthy food choices.

  7. Gender differences in factors affecting rejection of food in healthy young Swedish adults.

    Science.gov (United States)

    Nordin, S; Broman, D A; Garvill, J; Nyroos, M

    2004-12-01

    With the objectives to better understand gender-related differences in variables of importance for food intake, and interrelations between these variables, 100 healthy, young women and 100 healthy, young men responded to self-administrated questionnaires about general food rejection, learned illness-associated food aversions, disgust (the Disgust Scale), food neophobia (the Food Neophobia Scale), nausea and appetite. The results show that food rejection and aversions were more common in women (69 and 38%, respectively) than in men (47 and 18%), and that women are more disgust sensitive than men. However, no differences between women and men were observed regarding reasons for rejecting food (predominantly sensory attributes), prevalence of gastrointestinal illness as an associated aversion symptom (95 vs 89%), type of aversive food due to associated illness (predominantly high protein items), or food neophobia. Based on path analyses, a model is proposed of interrelations between disgust, food neophobia, learned food aversions, nausea, appetite, and general food rejection in healthy young adults.

  8. Food intake, growth, and reproduction as affected by day length and food availability in the pond snail Lymnaea stagnalis

    NARCIS (Netherlands)

    Maat, ter A.; Zonneveld, C.; Visser, de J.A.G.M.; Jansen, R.F.; Montagne-Wajer, K.; Koene, J.M.

    2007-01-01

    With the aim of integrating the physiology and evolutionary ecology of Lymnaea stagnalis (Linnaeus, 1758), we studied the effects of day length and food availability on the energy budget. Snails were assigned to two different photoperiods and three levels of food availability. The snails were kept i

  9. Food intake, growth, and reproduction as affected by day length and food availability in the pond snail Lymnaea stagnalis

    NARCIS (Netherlands)

    Maat, ter A.; Zonneveld, C.; Visser, de J.A.G.M.; Jansen, R.F.; Montagne-Wajer, K.; Koene, J.M.

    2007-01-01

    With the aim of integrating the physiology and evolutionary ecology of Lymnaea stagnalis (Linnaeus, 1758), we studied the effects of day length and food availability on the energy budget. Snails were assigned to two different photoperiods and three levels of food availability. The snails were kept

  10. Fire affects root decomposition, soil food web structure, and carbon flow in tallgrass prairie

    Science.gov (United States)

    Shaw, E. Ashley; Denef, Karolien; Milano de Tomasel, Cecilia; Cotrufo, M. Francesca; Wall, Diana H.

    2016-05-01

    Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is common and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to intact tallgrass prairie soil cores collected from annually burned (AB) and infrequently burned (IB) treatments at the Konza Prairie Long Term Ecological Research (LTER) site. Incorporation of 13C into microbial phospholipid fatty acids and nematode trophic groups was measured on six occasions during a 180-day decomposition study to determine how C was translocated through the soil food web. Results showed significantly different soil communities between treatments and higher microbial abundance for IB. Root decomposition occurred rapidly and was significantly greater for AB. Microbes and their nematode consumers immediately assimilated root litter C in both treatments. Root litter C was preferentially incorporated in a few groups of microbes and nematodes, but depended on burn treatment: fungi, Gram-negative bacteria, Gram-positive bacteria, and fungivore nematodes for AB and only omnivore nematodes for IB. The overall microbial pool of root-litter-derived C significantly increased over time but was not significantly different between burn treatments. The nematode pool of root-litter-derived C also significantly increased over time, and was significantly higher for the AB treatment at 35 and 90 days after litter addition. In conclusion, the C flow from root litter to microbes to nematodes is not only measurable but also significant, indicating that higher nematode trophic levels are critical components of C flow during root decomposition, which, in turn, is significantly affected by fire. Not

  11. Burning management in the tallgrass prairie affects root decomposition, soil food web structure and carbon flow

    Science.gov (United States)

    Shaw, E. A.; Denef, K.; Milano de Tomasel, C.; Cotrufo, M. F.; Wall, D. H.

    2015-09-01

    Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is a common management practice and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to intact tallgrass prairie soil cores collected from annually burned (AB) and infrequently burned (IB) treatments at the Konza Prairie Long Term Ecological Research (LTER) site. Incorporation of 13C into microbial phospholipid fatty acids and nematode trophic groups was measured on six occasions during a 180-day decomposition study to determine how C was translocated through the soil food web. Results showed significantly different soil communities between treatments and higher microbial abundance for IB. Root decomposition occurred rapidly and was significantly greater for AB. Microbes and their nematode consumers immediately assimilated root litter C in both treatments. Root litter C was preferentially incorporated in a few groups of microbes and nematodes, but depended on burn treatment: fungi, Gram-negative bacteria, Gram-positive bacteria, and fungivore nematodes for AB and only omnivore nematodes for IB. The overall microbial pool of root litter-derived C significantly increased over time but was not significantly different between burn treatments. The nematode pool of root litter-derived C also significantly increased over time, and was significantly higher for the AB treatment at 35 and 90 days after litter addition. In conclusion, the C flow from root litter to microbes to nematodes is not only measurable, but significant, indicating that higher nematode trophic levels are critical components of C flow during root decomposition which, in turn, is significantly

  12. Larval helminths in intermediate hosts

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2005-01-01

    a reduction in size, caused by crowding, virtually nothing is known about longer-lasting effects after transmission to the definitive host. This study is the first to use in vitro cultivation with feeding of adult trematodes to investigate how numbers of parasites in the intermediate host affect the size......Density-dependent effects on parasite fitness have been documented from adult helminths in their definitive hosts. There have, however, been no studies on the cost of sharing an intermediate host with other parasites in terms of reduced adult parasite fecundity. Even if larval parasites suffer...... and fecundity of adult parasites. For this purpose, we examined two different infracommunities of parasites in crustacean hosts. Firstly, we used experimental infections of Maritrema novaezealandensis in the amphipod, Paracalliope novizealandiae, to investigate potential density-dependent effects in single...

  13. Increasing Plant Based Foods or Dairy Foods Differentially Affects Nutrient Intakes: Dietary Scenarios Using NHANES 2007-2010.

    Science.gov (United States)

    Cifelli, Christopher J; Houchins, Jenny A; Demmer, Elieke; Fulgoni, Victor L

    2016-07-11

    Diets rich in plant foods and lower in animal-based products have garnered increased attention among researchers, dietitians and health professionals in recent years for their potential to, not only improve health, but also to lessen the environmental impact. However, the potential effects of increasing plant-based foods at the expense of animal-based foods on macro- and micronutrient nutrient adequacy in the U.S. diet is unknown. In addition, dairy foods are consistently under consumed, thus the impact of increased dairy on nutrient adequacy is important to measure. Accordingly, the objective of this study was to use national survey data to model three different dietary scenarios to assess the effects of increasing plant-based foods or dairy foods on macronutrient intake and nutrient adequacy. Data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010 for persons two years and older (n = 17,387) were used in all the analyses. Comparisons were made of usual intake of macronutrients and shortfall nutrients of three dietary scenarios that increased intakes by 100%: (i) plant-based foods; (ii) protein-rich plant-based foods (i.e., legumes, nuts, seeds, soy); and (iii) milk, cheese and yogurt. Scenarios (i) and (ii) had commensurate reductions in animal product intake. In both children (2-18 years) and adults (≥19 years), the percent not meeting the Estimated Average Requirement (EAR) decreased for vitamin C, magnesium, vitamin E, folate and iron when plant-based foods were increased. However the percent not meeting the EAR increased for calcium, protein, vitamin A, and vitamin D in this scenario. Doubling protein-rich plant-based foods had no effect on nutrient intake because they were consumed in very low quantities in the baseline diet. The dairy model reduced the percent not meeting the EAR for calcium, vitamin A, vitamin D, magnesium, and protein, while sodium and saturated fat levels increased. Our modeling shows that increasing plant

  14. Increasing Plant Based Foods or Dairy Foods Differentially Affects Nutrient Intakes: Dietary Scenarios Using NHANES 2007–2010

    Directory of Open Access Journals (Sweden)

    Christopher J. Cifelli

    2016-07-01

    Full Text Available Diets rich in plant foods and lower in animal-based products have garnered increased attention among researchers, dietitians and health professionals in recent years for their potential to, not only improve health, but also to lessen the environmental impact. However, the potential effects of increasing plant-based foods at the expense of animal-based foods on macro- and micronutrient nutrient adequacy in the U.S. diet is unknown. In addition, dairy foods are consistently under consumed, thus the impact of increased dairy on nutrient adequacy is important to measure. Accordingly, the objective of this study was to use national survey data to model three different dietary scenarios to assess the effects of increasing plant-based foods or dairy foods on macronutrient intake and nutrient adequacy. Data from the National Health and Nutrition Examination Survey (NHANES 2007–2010 for persons two years and older (n = 17,387 were used in all the analyses. Comparisons were made of usual intake of macronutrients and shortfall nutrients of three dietary scenarios that increased intakes by 100%: (i plant-based foods; (ii protein-rich plant-based foods (i.e., legumes, nuts, seeds, soy; and (iii milk, cheese and yogurt. Scenarios (i and (ii had commensurate reductions in animal product intake. In both children (2–18 years and adults (≥19 years, the percent not meeting the Estimated Average Requirement (EAR decreased for vitamin C, magnesium, vitamin E, folate and iron when plant-based foods were increased. However the percent not meeting the EAR increased for calcium, protein, vitamin A, and vitamin D in this scenario. Doubling protein-rich plant-based foods had no effect on nutrient intake because they were consumed in very low quantities in the baseline diet. The dairy model reduced the percent not meeting the EAR for calcium, vitamin A, vitamin D, magnesium, and protein, while sodium and saturated fat levels increased. Our modeling shows that

  15. Do hunger and exposure to food affect scores on a measure of hedonic hunger? An experimental study.

    Science.gov (United States)

    Witt, Ashley A; Raggio, Greer A; Butryn, Meghan L; Lowe, Michael R

    2014-03-01

    Research suggests that visceral bodily states, such as hunger, can affect participants' responses on self-report measures of eating behavior. The present study evaluated the influence of hunger and exposure to palatable food on self-reported hedonic appetite, measured using the Power of Food Scale (PFS). A secondary aim was to evaluate the effects of these manipulations on self-reported external eating and disinhibition. Participants (N=67) ate a standardized meal followed by a 4-h fast. Participants were randomized to one of four groups (Fasted/Food Absence, Fasted/Food Exposure, Fed/Food Absence, or Fed/Food Exposure). In Phase I of the experiment (Hunger Manipulation), participants randomized to the "Fed" group drank a protein shake, while those in the "Fasted" group did not receive a shake. In Phase II (Palatable Food Exposure), participants in the "Food Exposure" group were visually exposed to palatable food items, while "Food Absence" participants were not. All participants completed the PFS, Dutch Eating Behavior Questionnaire External Eating subscale, and the Disinhibition subscale from the Eating Inventory during Phase II. Results showed no significant main or interactive effects of Hunger condition or Food Exposure condition on PFS, External Eating, or Disinhibition scores (all p'setas squared ⩽.015). Manipulation checks confirmed that the intended hunger and exposure interventions were successful. Results suggest that relatively short fasting periods (e.g., 4h) analogous to typical breaks between meals are not associated with changes in scores on the PFS, External Eating, or Disinhibition scales. Hedonic hunger, at least as measured by the PFS, may represent a relatively stable construct that is not substantially affected by daily variations in hunger. In addition, individual differences in exposure to food in the immediate environment are unlikely to confound research using these measures.

  16. Assessment of the emotional responses produced by exposure to real food, virtual food and photographs of food in patients affected by eating disorders

    Directory of Open Access Journals (Sweden)

    Petrova Anna

    2010-07-01

    Full Text Available Abstract Background Many researchers and clinicians have proposed using virtual reality (VR in adjunct to in vivo exposure therapy to provide an innovative form of exposure to patients suffering from different psychological disorders. The rationale behind the 'virtual approach' is that real and virtual exposures elicit a comparable emotional reaction in subjects, even if, to date, there are no experimental data that directly compare these two conditions. To test whether virtual stimuli are as effective as real stimuli, and more effective than photographs in the anxiety induction process, we tested the emotional reactions to real food (RF, virtual reality (VR food and photographs (PH of food in two samples of patients affected, respectively, by anorexia (AN and bulimia nervosa (BN compared to a group of healthy subjects. The two main hypotheses were the following: (a the virtual exposure elicits emotional responses comparable to those produced by the real exposure; (b the sense of presence induced by the VR immersion makes the virtual experience more ecological, and consequently more effective than static pictures in producing emotional responses in humans. Methods In total, 10 AN, 10 BN and 10 healthy control subjects (CTR were randomly exposed to three experimental conditions: RF, PH, and VR while their psychological (Stait Anxiety Inventory (STAI-S and visual analogue scale for anxiety (VAS-A and physiological (heart rate, respiration rate, and skin conductance responses were recorded. Results RF and VR induced a comparable emotional reaction in patients higher than the one elicited by the PH condition. We also found a significant effect in the subjects' degree of presence experienced in the VR condition about their level of perceived anxiety (STAI-S and VAS-A: the higher the sense of presence, the stronger the level of anxiety. Conclusions Even though preliminary, the present data show that VR is more effective than PH in eliciting emotional

  17. Food Contaminant Zearalenone and Its Metabolites Affect Cytokine Synthesis and Intestinal Epithelial Integrity of Porcine Cells

    Science.gov (United States)

    Marin, Daniela E.; Motiu, Monica; Taranu, Ionelia

    2015-01-01

    The intestinal epithelium is the first barrier against food contaminants. Zearalenone (ZEN) is an estrogenic mycotoxin that was identified as a common contaminant of cereal grains and food and feedstuffs. In the present study, we have investigated the in vitro effects of ZEN and some of its metabolites (α-ZOL, β-ZOL) in concentrations of 10–100 µM on a swine epithelial cell line: Intestinal porcine epithelial cells (IPEC-1). We demonstrated that both ZEN metabolites were more toxic for IPEC cells as resulted from the XTT test, while for doses lower than 10 µM, only β-ZOL showed a more pronounced cytotoxicity versus epithelial cells as resulted from neutral red assay. ZEN has no effect on TER values, while α-ZOL significantly decreased the TER values, starting with day 4 of treatment. β-ZOL had a dual effect, firstly it induced a significant increase of TER, and then, starting on day 6, it induced a dramatic decrease of TER values as compared with on day 0. Concerning the cytokine synthesis, our results showed that ZEN has a tendency to increase the synthesis of IL-8 and IL-10. By contrast, α- and β-ZOL decreased the expression of both IL-8 and IL-10, in a dose dependent manner. In conclusion, our results showed that ZEN and its metabolites differently affected porcine intestinal cell viability, transepithelial resistance and cytokine synthesis with important implication for gut health. PMID:26035492

  18. In vitro selenium accessibility in pet foods is affected by diet composition and type.

    Science.gov (United States)

    van Zelst, Mariëlle; Hesta, Myriam; Alexander, Lucille G; Gray, Kerry; Bosch, Guido; Hendriks, Wouter H; Du Laing, Gijs; De Meulenaer, Bruno; Goethals, Klara; Janssens, Geert P J

    2015-06-28

    Se bioavailability in commercial pet foods has been shown to be highly variable. The aim of the present study was to identify dietary factors associated with in vitro accessibility of Se (Se Aiv) in pet foods. Se Aiv is defined as the percentage of Se from the diet that is potentially available for absorption after in vitro digestion. Sixty-two diets (dog, n 52; cat, n 10) were in vitro enzymatically digested: fifty-four of them were commercially available (kibble, n 20; pellet, n 8; canned, n 17; raw meat, n 6; steamed meat, n 3) and eight were unprocessed (kibble, n 4; canned, n 4) from the same batch as the corresponding processed diets. The present investigation examined if Se Aiv was affected by diet type, dietary protein, methionine, cysteine, lysine and Se content, DM, organic matter and crude protein (CP) digestibility. Se Aiv differed significantly among diet types (Pcanning process (n 4) decreased Se Aiv (P =0·001), whereas extrusion (n 4) revealed no effect on Se Aiv (P =0·297). These differences in Se Aiv between diet types warrant quantification of diet type effects on in vivo Se bioavailability.

  19. Second-hand eating? Maternal perception of the food environment affects reproductive investment in mice.

    Science.gov (United States)

    Schwartz, Tonia S; Gainer, Renee; Dohm, Erik D; Johnson, Maria S; Wyss, J Michael; Allison, David B

    2015-05-01

    Little information exists on how perception of the food (or "energetic") environment affects body composition and reproductive investment. The hypothesis was tested that female mice, who are themselves consuming standard chow diets but who are exposed to conspecifics eating a rich "cafeteria diet," will exhibit altered weight gain and reproductive investment. Female C57BL/6 mice were raised on a cafeteria diet. At maturity, subjects were switched to a standard chow diet, and their cage-mates were assigned to consume either a cafeteria diet (treatment, n = 20) or standard chow (control, n = 20). Subjects were mated and pups raised to weaning. Subjects and pups were analyzed for body composition. Treatment had no discernable effect on dam body weight or composition but caused pups to have lower body weight (P = 0.036) and less fat mass (P = 0.041). A nearly significant treatment effect on "time to successful reproduction" (avg. 55 versus 44 days), likely due to increased failed first pregnancies, (14/19 versus 8/19, P = 0.099) was found. These data indicate that perceived food environment (independent of the diet actually consumed) can produce small pups with less body fat and possibly induce difficulties in pregnancy for dams. Replication and mechanistic studies should follow. © 2015 The Obesity Society.

  20. Food contaminant zearalenone and its metabolites affect cytokine synthesis and intestinal epithelial integrity of porcine cells.

    Science.gov (United States)

    Marin, Daniela E; Motiu, Monica; Taranu, Ionelia

    2015-05-29

    The intestinal epithelium is the first barrier against food contaminants. Zearalenone (ZEN) is an estrogenic mycotoxin that was identified as a common contaminant of cereal grains and food and feedstuffs. In the present study, we have investigated the in vitro effects of ZEN and some of its metabolites (α-ZOL, β-ZOL) in concentrations of 10-100 µM on a swine epithelial cell line: Intestinal porcine epithelial cells (IPEC-1). We demonstrated that both ZEN metabolites were more toxic for IPEC cells as resulted from the XTT test, while for doses lower than 10 µM, only β-ZOL showed a more pronounced cytotoxicity versus epithelial cells as resulted from neutral red assay. ZEN has no effect on TER values, while α-ZOL significantly decreased the TER values, starting with day 4 of treatment. β-ZOL had a dual effect, firstly it induced a significant increase of TER, and then, starting on day 6, it induced a dramatic decrease of TER values as compared with on day 0. Concerning the cytokine synthesis, our results showed that ZEN has a tendency to increase the synthesis of IL-8 and IL-10. By contrast, α- and β-ZOL decreased the expression of both IL-8 and IL-10, in a dose dependent manner. In conclusion, our results showed that ZEN and its metabolites differently affected porcine intestinal cell viability, transepithelial resistance and cytokine synthesis with important implication for gut health.

  1. Ecology of conflict: marine food supply affects human-wildlife interactions on land

    Science.gov (United States)

    Artelle, Kyle A.; Anderson, Sean C.; Reynolds, John D.; Cooper, Andrew B.; Paquet, Paul C.; Darimont, Chris T.

    2016-01-01

    Human-wildlife conflicts impose considerable costs to people and wildlife worldwide. Most research focuses on proximate causes, offering limited generalizable understanding of ultimate drivers. We tested three competing hypotheses (problem individuals, regional population saturation, limited food supply) that relate to underlying processes of human-grizzly bear (Ursus arctos horribilis) conflict, using data from British Columbia, Canada, between 1960–2014. We found most support for the limited food supply hypothesis: in bear populations that feed on spawning salmon (Oncorhynchus spp.), the annual number of bears/km2 killed due to conflicts with humans increased by an average of 20% (6–32% [95% CI]) for each 50% decrease in annual salmon biomass. Furthermore, we found that across all bear populations (with or without access to salmon), 81% of attacks on humans and 82% of conflict kills occurred after the approximate onset of hyperphagia (July 1st), a period of intense caloric demand. Contrary to practices by many management agencies, conflict frequency was not reduced by hunting or removal of problem individuals. Our finding that a marine resource affects terrestrial conflict suggests that evidence-based policy for reducing harm to wildlife and humans requires not only insight into ultimate drivers of conflict, but also management that spans ecosystem and jurisdictional boundaries. PMID:27185189

  2. Factors affecting the musculoskeletal disorders of workers in the frozen food manufacturing factories in Thailand.

    Science.gov (United States)

    Thetkathuek, Anamai; Meepradit, Parvena; Jaidee, Wanlop

    2016-01-01

    The purpose of this research was to study factors affecting musculoskeletal disorders. The sample population of the study was 528 factory workers from the frozen food industry, as well as a controlled group of 255 office workers. The samples were collected during interviews using the Nordic questionnaire to assess musculoskeletal disorders, and to assess the risk by the rapid upper limb assessment and rapid entire body assessment techniques. The findings of the study were that most symptoms were found in the dissecting department, higher than in the controlled group. The details of the symptoms were, accordingly: elbow pain (adjusted odds ratio, 35.1; 95% CI [17.4, 70.9]). Regarding the risk of alcohol drinking, workers were exposed to more risks when alcohol was consumed. It is suggested that workers' health should be monitored regularly. People who work in a cold environment should be encouraged to wear body protection and to avoid drinking.

  3. Source segregation of food waste in office areas: Factors affecting waste generation rates and quality

    DEFF Research Database (Denmark)

    Edjabou, Vincent Maklawe Essonanawe; Boldrin, Alessio; Scheutz, Charlotte;

    2015-01-01

    and the purity of the source-sorted food waste. The moisture content of source-sorted food waste and residual waste fractions, and potential methane production from source-sorted food waste, was also investigated.Food waste generation equated to 23. ±. 5. kg/employee/year, of which 20. ±. 5. kg...

  4. Food-web composition affects cross-ecosystem interactions and subsidies.

    Science.gov (United States)

    Romero, Gustavo Q; Srivastava, Diane S

    2010-09-01

    1. Ecosystems may affect each other through trophic interactions that cross ecosystem boundaries as well as via the transfer of subsidies, but these effects can vary depending on the identity of species involved in the interaction. 2. In this study, we manipulated two terrestrial bromeliad-living spider species (Aglaoctenus castaneus, Corinna gr. rubripes) that have variable hunting modes, to test their individual and combined effects on aquatic invertebrate community structure and ecosystem processes (i.e. decomposition rate and nitrogen cycling). We predicted that these terrestrial predators can affect aquatic invertebrates and nutrient dynamics within water-filled bromeliads. 3. Aglaoctenus spiders reduced the richness, abundance and biomass of aquatic insect larvae via consumptive or non-consumptive effects on ovipositing terrestrial adults, but effects of the two spider species in combination were usually the linear average of their monoculture effects. In contrast, invertebrates with entirely aquatic life cycles were unaffected or facilitated by spiders. Spiders did not affect either net detritivore biomass or the flux of detrital nitrogen to the bromeliad. Instead, Corinna spiders contributed allochthonous nitrogen to bromeliads. 4. Our results provide the novel observations that predators in one ecosystem not only directly reduce taxa whose life cycles cross-ecosystem boundaries, but also indirectly facilitate taxa whose life cycles are entirely within the second ecosystem. This compensatory response between cross-ecosystem and within-ecosystem taxa may have led to an attenuation of top-down effects across ecosystem boundaries. In addition, our results add to a growing consensus that species identity is an important determinant of community structure and ecosystem functioning. Thus, the composition of both terrestrial and aquatic food webs may affect the strength of cross-ecosystem interactions.

  5. Re-feeding food-deprived male meadow voles affects the sperm allocation of their rival males.

    Science.gov (United States)

    Vaughn, Ashlee A; Delbarco-Trillo, Javier; Ferkin, Michael H

    2012-12-01

    An individual's nutritional status affects the manner in which same- and opposite-sex conspecifics respond to that individual, which may affect their fitness. Male meadow voles, Microtus pennsylvanicus, increase their sperm allocation if they encounter the scent mark of an unfamiliar male that is not nutritionally challenged. If, however, the scent mark comes from a male that has been food deprived for 24 hours, stud male voles do not increase their sperm allocation. Food deprived males may be viewed as being lower quality and a reduced risk of sperm competition by rival males. We hypothesized that stud males in promiscuous mating systems tailor their sperm allocations depending on whether rival males have been food deprived and then re-fed. We predicted that newly re-fed males will be considered a strong risk of sperm competition because of the potentially high fitness and survival costs associated with food deprivation in males, and that they will cause stud males to increase their sperm allocation. Our results, however, showed that the recovery period from 24 hours of food deprivation was a relatively slow process. It took between 96 hours and 336 hours of re-feeding male scent donors that were food deprived for 24 hours to induce stud males to increase their sperm allocation to levels comparable to when scent donors were not food deprived. Stud male voles may be conserving the amount of sperm allocated until the male scent donors have recovered from food deprivation and subsequent re-feeding.

  6. Emotional communication in the context of joint attention for food stimuli: effects on attentional and affective processing.

    Science.gov (United States)

    Soussignan, Robert; Schaal, Benoist; Boulanger, Véronique; Garcia, Samuel; Jiang, Tao

    2015-01-01

    Guided by distinct theoretical frameworks (the embodiment theories, shared-signal hypothesis, and appraisal theories), we examined the effects of gaze direction and emotional expressions (joy, disgust, and neutral) of virtual characters on attention orienting and affective reactivity of participants while they were engaged in joint attention for food stimuli contrasted by preference (disliked, moderately liked, and liked). The participants were exposed to videos of avatars looking at food and displaying facial expressions with their gaze directed either toward the food only or toward the food and participants consecutively. We recorded eye-tracking responses, heart rate, facial electromyography (zygomatic, corrugator, and levator labii regions), and food wanting/liking. The avatars' joy faces increased the participants' zygomatic reactions and food liking, with mutual eye contact boosting attentional responses. Eye contact also fostered disgust reactions to disliked food, regardless of the avatars' expressions. The findings show that joint attention for food accompanied by face-to-face emotional communication elicits differential attentional and affective responses. The findings appear consistent with the appraisal theories of emotion.

  7. Laboratory studies on larval growth of Polydora ligni, Polydora ciliata, and Pygospio elegans (Polychaeta, Spionidae)

    Science.gov (United States)

    Anger, K.; Anger, V.; Hagmeier, E.

    1986-12-01

    The spionid polychaete species Polydora ligni, P. ciliata, and Pygospio elegans were cultivated in the laboratory over several successive generations. A flow-through cultivation system for Polydora spp. is described. Duration of life cycles (time from hatching of the larva to first reproduction) and life spans (hatching to death) of these species were not significantly influenced by the degree of inbreeding nor by individual age of the parents. Minimum time from metamorphosis (15-setiger stage) to first hatching of offspring larvae (in the 3-setiger stage) at 18°C was 33 days in Polydora spp. and 81 days in Pygospio elegans. Larval growth patterns are described in terms of number of setigers, body length, and biomass (dry weight, carbon, nitrogen, hydrogen), in relation to time after hatching. Regression models are proposed which link these measures of larval growth and, thus, may be used for conversions. Rates of development and growth show a high degree of variability in all three species, not only caused by variation in environmental factors such as temperature or food, but also among and within single hatches of larvae reared under identical conditions. Larvae were reared at constant temperatures (6°, 12°, and 18°C). Temperature affected larval growth in Polydora ligni more than in P. ciliata, and least of all in Pygospio elegans. Only the latter species was able to develop at 6°C from hatching to metamorphosis. This differential response may be explained by differences in the natural spawning season of these species. Eleven phytoplankton species were tested as to their food values. A “relative index of growth” is proposed which compares the slopes of two growth curves (one standard and one test condition). The flagellate Dunaliella tertiolecta was used as a standard food in these experiments. Most algal species were less suitable, and only the diatom Thalassiosira rotula was consistently better food for spionid larvae than D. tertiolecta.

  8. Fitness consequences of larval exposure to Beauveria bassiana on adults of the malaria vector Anopheles stephensi.

    Science.gov (United States)

    Vogels, Chantal B F; Bukhari, Tullu; Koenraadt, Constantianus J M

    2014-06-01

    Entomopathogenic fungi have shown to be effective in biological control of both larval and adult stages of malaria mosquitoes. However, a small fraction of mosquitoes is still able to emerge after treatment with fungus during the larval stage. It remains unclear whether fitness of these adults is affected by the treatment during the larval stage and whether they are still susceptible for another treatment during the adult stage. Therefore, we tested the effects of larval exposure to the entomopathogenic fungus Beauveria bassiana on fitness of surviving Anopheles stephensi females. Furthermore, we tested whether larval exposed females were still susceptible to re-exposure to the fungus during the adult stage. Sex ratio, survival and reproductive success were compared between non-exposed and larval exposed A. stephensi. Comparisons were also made between survival of non-exposed and larval exposed females that were re-exposed to B. bassiana during the adult stage. Larval treatment did not affect sex ratio of emerging mosquitoes. Larval exposed females that were infected died significantly faster and laid equal numbers of eggs from which equal numbers of larvae hatched, compared to non-exposed females. Larval exposed females that were uninfected had equal survival, but laid a significantly larger number of eggs from which a significantly higher number of larvae hatched, compared to non-exposed females. Larval exposed females which were re-exposed to B. bassiana during the adult stage had equal survival as females exposed only during the adult stage. Our results suggest that individual consequences for fitness of larval exposed females depended on whether a fungal infection was acquired during the larval stage. Larval exposed females remained susceptible to re-exposure with B. bassiana during the adult stage, indicating that larval and adult control of malaria mosquitoes with EF are compatible.

  9. Task-Based and Questionnaire Measures of Inhibitory Control Are Differentially Affected by Acute Food Restriction and by Motivationally Salient Food Stimuli in Healthy Adults.

    Science.gov (United States)

    Bartholdy, Savani; Cheng, Jiumu; Schmidt, Ulrike; Campbell, Iain C; O'Daly, Owen G

    2016-01-01

    Adaptive eating behaviors are dependent on an interaction between motivational states (e.g., hunger) and the ability to control one's own behavior (inhibitory control). Indeed, behavioral paradigms are emerging that seek to train inhibitory control to improve eating behavior. However, inhibitory control is a multifaceted concept, and it is not yet clear how different types (e.g., reactive motor inhibition, proactive motor inhibition, reward-related inhibition) are affected by hunger. Such knowledge will provide insight into the contexts in which behavioral training paradigms would be most effective. The present study explored the impact of promoting a "need" state (hunger) together with motivationally salient distracting stimuli (food/non-food images) on inhibitory control in 46 healthy adults. Participants attended two study sessions, once after eating breakfast as usual and once after acute food restriction on the morning of the session. In each session, participants completed questionnaires on hunger, mood and inhibitory control, and undertook task-based measures of inhibitory control, and had physiological measurements (height, weight, and blood glucose) obtained by a researcher. Acute food restriction influenced task-based assessments but not questionnaire measures of inhibitory control, suggesting that hunger affects observable behavioral control but not self-reported inhibitory control. After acute food restriction, participants showed greater temporal discounting (devaluation of future rewards), and subjective hunger and these were inversely correlated with stop accuracy on the stop signal task. Finally, participants generally responded faster when food-related distractor images were presented, compared to non-food images, independent of state. This suggests that although food stimuli motivate approach behavior, stimulus relevance does not impact inhibitory control in healthy individuals, nor interact with motivational state. These findings may provide some

  10. Task-based and questionnaire measures of inhibitory control are differentially affected by acute food restriction and by motivationally salient food stimuli in healthy adults

    Directory of Open Access Journals (Sweden)

    Savani Bartholdy

    2016-08-01

    Full Text Available Adaptive eating behaviors are dependent on an interaction between motivational states (e.g., hunger and the ability to control one’s own behavior (inhibitory control. Indeed, behavioral paradigms are emerging that seek to train inhibitory control to improve eating behavior. However, inhibitory control is a multifaceted concept, and it is not yet clear how different types (e.g., reactive motor inhibition, proactive motor inhibition, reward-related inhibition are affected by hunger. Such knowledge will provide insight into the contexts in which behavioral training paradigms would be most effective. The present study explored the impact of promoting a need state (hunger together with motivationally salient distracting stimuli (food/non-food images on inhibitory control in 46 healthy adults. Participants attended two study sessions, once after eating breakfast as usual and once after acute food restriction on the morning of the session. In each session, participants completed questionnaires on hunger, mood and inhibitory control, and undertook task-based measures of inhibitory control, and had physiological measurements (height, weight and blood glucose obtained by a researcher. Acute food restriction influenced task-based assessments but not questionnaire measures of inhibitory control, suggesting that hunger affects observable behavioral control but not self-reported inhibitory control. After acute food restriction, participants showed greater temporal discounting (devaluation of future rewards, and subjective hunger and these were inversely correlated with stop accuracy on the stop signal task. Finally, participants generally responded faster when food-related distractor images were presented, compared to non-food images, independent of state. This suggests that although food stimuli motivate approach behavior, stimulus relevance does not impact inhibitory control in healthy individuals, nor interact with motivational state. These findings may

  11. Portion size variably affects food intake of 6-year-old and 4-year-old children in Kunming, China.

    Science.gov (United States)

    Smith, Lindsey; Conroy, Katharine; Wen, Hongmei; Rui, Li; Humphries, Debbie

    2013-10-01

    Age and portion size have been found to influence food intake in American children but have not been examined in an international context. This study evaluated the association between age and the effects of portion size on the food intake of kindergarteners in Kunming, China. Using a within-subjects crossover design in a classroom setting, 173 children in two age groups, mean age 4.2 years and 6.1 years, were served a predefined reference, small (-30%) and large (+30%) portion of rice, vegetables, and a protein source during lunchtime over three consecutive days. Each portion was weighed before and after the meal to determine amount of food consumed. Linear mixed modeling, controlling for repeated measures and clustering by classroom, was used to compare food intake under small and large portion size conditions to the reference portion. Children ate significantly less food when served small portions. When served a large portion, 6-year-old children increased food intake while 4-year-old children decreased food intake in comparison to the reference portion. Findings indicate that portion size affects food intake in Chinese children 4-6-years old. Older children show larger increases in food intake with increased portion size than do younger children.

  12. Numerical simulations of barnacle larval dispersion coupled with field observations on larval abundance, settlement and recruitment in a tropical monsoon influenced coastal marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, C.A.; Samiksha S.V.; George, G.; Aboobacker V.M.; Vethamony, P.; Anil, A.C.

    different circumstances. Environmental variability is the main cause for such differences. Larvae are likely to disperse or retain more without settling behavior or mortality factors. Factors such as food availability and predation can also influence... both feeding as well as non-feeding stages, success of larval populations depends on its dispersal/retention to habitats with sufficient food. The non-feeding larval stage (cyprids) can last for several days depending on the stored energy content...

  13. Larval nervous systems

    DEFF Research Database (Denmark)

    Nielsen, Claus

    2015-01-01

    The apical organ of ciliated larvae of cnidarians and bilaterians is a true larval organ that disappears before or at metamorphosis. It appears to be sensory, probably involved in metamorphosis, but knowledge is scant. The ciliated protostome larvae show ganglia/nerve cords that are retained as t...... common ancestor of the deuterostomes was very similar to the latest common pelago-benthic ancestor of the protostomes as described by the trochaea theory, and that the neural tube of the chordates is morphologically ventral....

  14. ‘Peer pressure’ in larval Drosophila?

    Directory of Open Access Journals (Sweden)

    Thomas Niewalda

    2014-06-01

    Full Text Available Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on ‘peer pressure’, that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i by the level of innate olfactory preference in the surrounding group nor (ii by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii by the level of innate olfactory preference of the surrounding group nor (iv by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila.

  15. Bioaerosols from a Food Waste Composting Plant Affect Human Airway Epithelial Cell Remodeling Genes

    Directory of Open Access Journals (Sweden)

    Ming-Wei Chang

    2013-12-01

    Full Text Available The composting procedure in food waste plants generates airborne bioaerosols that have the potential to damage human airway epithelial cells. Persistent inflammation and repair responses induce airway remodeling and damage to the respiratory system. This study elucidated the expression changes of airway remodeling genes in human lung mucoepidermoid NCI-H292 cells exposed to bioaerosols from a composting plant. Different types of microorganisms were detectable in the composting plant, using the agar culture method. Real-time polymerase chain reaction was used to quantify the level of Aspergillus fumigatus and the profile of remodeling genes. The real-time PCR results indicated that the amount of A. fumigatus in the composting hall was less than 102 conidia. The endotoxins in the field bioaerosols were determined using a limulus amebocyte lysate test. The endotoxin levels depended on the type of particulate matter (PM, with coarse particles (2.5–10 μm having higher endotoxin levels than did fine particles (0.5–2.5 μm. After exposure to the conditioned medium of field bioaerosol samples, NCI-H292 cells showed increased pro-inflammatory interleukin (IL-6 release and activated epidermal growth factor receptor (EGFR, transforming growth factor (TGF-β1 and cyclin-dependent kinase inhibitor 1 (p21WAF1/CIP1 gene expression, but not of matrix metallopeptidase (MMP-9. Airborne endotoxin levels were higher inside the composting hall than they were in other areas, and they were associated with PM. This suggested that airborne bioaerosols in the composting plant contained endotoxins and microorganisms besides A. fumigatus that cause the inflammatory cytokine secretion and augment the expression of remodeling genes in NCI-H292 cells. It is thus necessary to monitor potentially hazardous materials from bioaerosols in food composting plants, which could affect the health of workers.

  16. Precipitation variability on global pasturelands may affect food security in livestock-dependent regions

    Science.gov (United States)

    Sloat, L.; Gerber, J. S.; Samberg, L. H.; Smith, W. K.; West, P. C.; Herrero, M.; Brendan, P.; Cecile, G.; Katharina, W.; Smith, W. K.

    2016-12-01

    The need to feed an increasing number of people while maintaining biodiversity and ecosystem services is one of the key challenges currently facing humanity. Livestock systems are likely to be a crucial piece of this puzzle, as urbanization and changing diets in much of the world lead to increases in global meat consumption. This predicted increase in global demand for livestock products will challenge the ability of pastures and rangelands to maintain or increase their productivity. The majority of people that depend on animal production for food security do so through grazing and herding on natural rangelands, and these systems make a significant contribution to global production of meat and milk. The vegetation dynamics of natural forage are highly dependent on climate, and subject to disruption with changes in climate and climate variability. Precipitation heterogeneity has been linked to the ecosystem dynamics of grazing lands through impacts on livestock carrying capacity and grassland degradation potential. Additionally, changes in precipitation variability are linked to the increased incidence of extreme events (e.g. droughts, floods) that negatively impact food production and food security. Here, we use the inter-annual coefficient of variation (CV) of precipitation as a metric to assess climate risk on global pastures. Comparisons of global satellite measures of vegetation greenness to climate reveal that the CV of precipitation is negatively related to mean annual NDVI, such that areas with low year-to-year precipitation variability have the highest measures of vegetation greenness, and vice versa. Furthermore, areas with high CV of precipitation support lower livestock densities and produce less meat. A sliding window analysis of changes in CV of precipitation over the last century shows that, overall, precipitation variability is increasing in global pasture areas, although global maps reveal a patchwork of both positive and negative changes. We use

  17. Experimental food supplementation affects the physical development, behaviour and survival of Little Owl Athene noctua nestlings

    National Research Council Canada - National Science Library

    Perrig, Marco; Grüebler, Martin U; Keil, Herbert; Naef‐Daenzer, Beat; Rutz, Christian

    2014-01-01

    ...‐fostering and food supplementation experiment, we estimated the effect of variation in food supply during growth on nestling survival and fledgling phenotypic traits of Little Owls Athene noctua...

  18. Limited Evidence That Competitive Food and Beverage Practices Affect Adolescent Consumption Behaviors

    Science.gov (United States)

    Vericker, Tracy C.

    2013-01-01

    Childhood obesity is emerging as a considerable public health problem with no clear antidote. The school food environment is a potential intervention point for policy makers, with competitive food and beverage regulation as a possible policy lever. This research examines the link between competitive food and beverage availability in school and…

  19. Manipulations of Start and Food Locations Affect Navigation on a Foraging Task

    Science.gov (United States)

    Martin, Gerard M.; Pirzada, Ashar; Bridger, Alexander; Tomlin, Julian; Thorpe, Christina M.; Skinner, Darlene M.

    2011-01-01

    Rats were able to search multiple food cups in a foraging task and successfully return to a fixed, but not a variable, start location. Reducing the number of food cups to be searched resulted in an improvement in performance in the variable start condition. Performance was better when only one or two food cups had to be visited but was still…

  20. Limited Evidence That Competitive Food and Beverage Practices Affect Adolescent Consumption Behaviors

    Science.gov (United States)

    Vericker, Tracy C.

    2013-01-01

    Childhood obesity is emerging as a considerable public health problem with no clear antidote. The school food environment is a potential intervention point for policy makers, with competitive food and beverage regulation as a possible policy lever. This research examines the link between competitive food and beverage availability in school and…

  1. Does Household Food Insecurity Affect the Nutritional Status of Preschool Children Aged 6–36 Months?

    Directory of Open Access Journals (Sweden)

    Mahama Saaka

    2013-01-01

    Full Text Available Introduction. This study used three dependent measures of food security to assess the magnitude of household food insecurity and its consequences on the nutritional status of children 6–36 months in Tamale Metropolis of Northern Ghana. Methods. An analytical cross-sectional study was conducted on a sample of 337 mother/child pairs in June 2012. Food access was measured as household food insecurity access scale (HFIAS, household dietary diversity score (HDDS, and food consumption score (FCS. Results. The magnitude of household food insecurity depended on the food access indicator, with HFIAS yielding the highest household food insecurity of 54%. Of the three food access indicators, 30-day HFIAS was not related to any of the nutrition indices measured. HDDS and FCS were both significantly associated with BMI of mothers and chronic malnutrition (stunted growth but not acute malnutrition (wasting with FCS being a stronger predictor of nutritional status. Compared to children in food insecure households, children in food secure households were 46% protected from chronic malnutrition (, 95% CI: 0.31–0.94. Conclusions and Recommendations. The results of this study show that different measures of household food insecurity produce varied degree of the problem. Efforts at reducing chronic child malnutrition should focus on improving the adequacy of the diet.

  2. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk, vi...

  3. The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees

    Directory of Open Access Journals (Sweden)

    Bryan R. Helm

    2017-06-01

    Full Text Available In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee, Apis mellifera, nurse bees provision food to developing larvae, directly moderating growth rates and caste development. However, the eusocial nature of honey bees makes nutritional studies challenging, because diet components cannot be systematically manipulated in the hive. Using in vitro rearing, we investigated the roles and interactions between carbohydrate and protein content on larval survival, growth, and development in A. mellifera. We applied a geometric framework to determine how these two nutritional components interact across nine artificial diets. Honey bees successfully completed larval development under a wide range of protein and carbohydrate contents, with the medium protein (∼5% diet having the highest survival. Protein and carbohydrate both had significant and non-linear effects on growth rate, with the highest growth rates observed on a medium-protein, low-carbohydrate diet. Diet composition did not have a statistically significant effect on development time. These results confirm previous findings that protein and carbohydrate content affect the growth of A. mellifera larvae. However, this study identified an interaction between carbohydrate and protein content that indicates a low-protein, high-carb diet has a negative effect on larval growth and survival. These results imply that worker recruitment in the hive would decline under low protein conditions, even when nectar abundance or honey stores are sufficient.

  4. Match/mismatch between the Mytilus edulis larval supply and seston quality: effect on recruitment.

    Science.gov (United States)

    Toupoint, Nicolas; Gilmore-Solomon, Lisandre; Bourque, François; Myrand, Bruno; Pernet, Fabrice; Olivier, Frédéric; Tremblay, Réjean

    2012-08-01

    We considered Cushing's match/mismatch theory in a heterotrophic environment and hypothesized that settlement and recruitment success in blue mussel are higher when the food supply is rich in polyunsaturated and essential fatty acids (PUFA/EFA). To test this hypothesis, we monitored larval development as well as fatty acid composition in trophic resources during two successive reproductive seasons. The decoupling we found between the presence of competent larvae in the water column and settlement rates strongly suggests that metamorphosis is delayed until conditions are suitable. In both years, the major mussel settlement peak was synchronized with a phytoplanktonic pulse rich in EFA, consisting of a large autotrophic bloom in 2007 and a short but substantial peak of picoeukaryotes in 2008. These results suggest a "trophic settlement trigger" that indirectly affects recruitment by strongly improving the settlement rate. Despite similar larval settlement rates during both years, the lower 2007 recruitment likely resulted from a mismatch with a high lipid-quality trophic resource. The seasonal trophic conditions differed greatly between the two years, with fatty acids profiles reflecting heterotrophic plankton production in 2007 and mostly autotrophic production in 2008. In agreement with Cushing's theory, our results highlight a match/mismatch, related to the food lipid quality rather than food quantity. For the first time, we show that the recruitment in marine bivalves may be dependent on phytoplanktonic pulses characterized by high levels of PUFA.

  5. Source segregation of food waste in office areas: Factors affecting waste generation rates and quality

    DEFF Research Database (Denmark)

    Edjabou, Vincent Maklawe Essonanawe; Boldrin, Alessio; Scheutz, Charlotte

    2015-01-01

    Existing legislation mandates that the amount of waste being recycled should be increased. Among others, in its Resource Strategy Plan, the Danish Government decided that at least 60% of food waste generated by the service sector, including in office areas, should be source-sorted and collected...... separately by 2018. To assess the achievability of these targets, source-sorted food waste and residual waste from office areas was collected and weighed on a daily basis during 133 working days. Waste composition analyses were conducted every week to investigate the efficiency of the source-sorting campaign...... and the purity of the source-sorted food waste. The moisture content of source-sorted food waste and residual waste fractions, and potential methane production from source-sorted food waste, was also investigated.Food waste generation equated to 23. ±. 5. kg/employee/year, of which 20. ±. 5. kg...

  6. How parental dietary behavior and food parenting practices affect children's dietary behavior. Interacting sources of influence?

    Science.gov (United States)

    Larsen, Junilla K; Hermans, Roel C J; Sleddens, Ester F C; Engels, Rutger C M E; Fisher, Jennifer O; Kremers, Stef P J

    2015-06-01

    Until now, the literatures on the effects of food parenting practices and parents' own dietary behavior on children's dietary behavior have largely been independent from one another. Integrating findings across these areas could provide insight on simultaneous and interacting influences on children's food intake. In this narrative review, we provide a conceptual model that bridges the gap between both literatures and consists of three main hypotheses. First, parental dietary behavior and food parenting practices are important interactive sources of influence on children's dietary behavior and Body Mass Index (BMI). Second, parental influences are importantly mediated by changes in the child's home food environment. Third, parenting context (i.e., parenting styles and differential parental treatment) moderates effects of food parenting practices, whereas child characteristics (i.e., temperament and appetitive traits) mainly moderate effects of the home food environment. Future studies testing (parts of) this conceptual model are needed to inform effective parent-child overweight preventive interventions.

  7. Does school size affect interest for purchasing local foods in the midwest?

    Science.gov (United States)

    Smith, Sylvia; Wleklinski, Danielle; Roth, Sara Long; Tragoudas, Ulrike

    2013-04-01

    Due to the recent surge in environmental consciousness and the need to address childhood obesity, Farm to School programs have gained momentum. Even though Farm to School programs have increased in popularity, many schools still fail to take advantage of the benefits from such programs. School food service employees' lack of familiarity with the benefits of Farm to School programs or the means to overcome obstacles to implement such programs, along with school size, may represent key variables that serve to explain why more schools do not purchase more local foods for their schools. This study used a convenience sampling methodology to gather information regarding food service employees' perceptions of the benefits and obstacles and their attitudes to purchasing and serving local foods in their schools. A self-administered questionnaire was used to collect data from school food service employees in southern Illinois. Data (n=151) were collected from 60 schools, representing 16 counties during the month of December, 2009. Purchasers from large- and medium-size schools perceived the "ability to know product sources" as a greater benefit to purchasing local food and perceived "cost of food," "adequate volume," "reliable supply of food quantity," "payment arrangement," and "packing material" as greater obstacles (p<0.05) compared to small schools. In addition, results indicated that food service employees were interested in receiving training to prepare and serve more local foods. Findings from this study indicate a need for continued education, development, and training to better prepare school food service purchasers in southern Illinois for how to buy more local foods to meet the 2020 legislation requiring schools to purchase at least 10% locally.

  8. When is it worth waiting for? Food quantity, but not food quality, affects delay tolerance in tufted capuchin monkeys.

    Science.gov (United States)

    De Petrillo, Francesca; Gori, Emanuele; Micucci, Antonia; Ponsi, Giorgia; Paglieri, Fabio; Addessi, Elsa

    2015-09-01

    When faced with choices between smaller sooner options and larger later options (i.e. intertemporal choices), both humans and non-human animals discount future rewards. Apparently, only humans consistently show the magnitude effect, according to which larger options are discounted over time at a lower rate than smaller options. Most of the studies carried out in non-human animals led instead to negative results. Here, we tested ten tufted capuchin monkeys (Sapajus spp.) in a delay choice task to evaluate whether they show a magnitude effect when choosing between different quantities of the same food or when the options are represented by high- and low-preferred foods in different conditions. Whereas food quality did not play a role, we provided the first evidence of an effect of the reward amount on temporal preferences in a non-human primate species, a result with potential implications for the validity of comparative studies on the evolution of delay tolerance. In contrast with human results, but as shown in other animal species, capuchins' choice of the larger later option decreased as the amount of the smaller sooner option increased. Capuchins based their temporal preferences on the quantity of the smaller sooner option, rather than on that of the larger later option, probably because in the wild they virtually never have to choose between the above two options at the same time, but they more often encounter them consecutively. Thus, paying attention to the sooner option and deciding on the basis of its features may be an adaptive strategy rather than an irrational response.

  9. Food's visually perceived fat content affects discrimination speed in an orthogonal spatial task.

    Science.gov (United States)

    Harrar, Vanessa; Toepel, Ulrike; Murray, Micah M; Spence, Charles

    2011-10-01

    Choosing what to eat is a complex activity for humans. Determining a food's pleasantness requires us to combine information about what is available at a given time with knowledge of the food's palatability, texture, fat content, and other nutritional information. It has been suggested that humans may have an implicit knowledge of a food's fat content based on its appearance; Toepel et al. (Neuroimage 44:967-974, 2009) reported visual-evoked potential modulations after participants viewed images of high-energy, high-fat food (HF), as compared to viewing low-fat food (LF). In the present study, we investigated whether there are any immediate behavioural consequences of these modulations for human performance. HF, LF, or non-food (NF) images were used to exogenously direct participants' attention to either the left or the right. Next, participants made speeded elevation discrimination responses (up vs. down) to visual targets presented either above or below the midline (and at one of three stimulus onset asynchronies: 150, 300, or 450 ms). Participants responded significantly more rapidly following the presentation of a HF image than following the presentation of either LF or NF images, despite the fact that the identity of the images was entirely task-irrelevant. Similar results were found when comparing response speeds following images of high-carbohydrate (HC) food items to low-carbohydrate (LC) food items. These results support the view that people rapidly process (i.e. within a few hundred milliseconds) the fat/carbohydrate/energy value or, perhaps more generally, the pleasantness of food. Potentially as a result of HF/HC food items being more pleasant and thus having a higher incentive value, it seems as though seeing these foods results in a response readiness, or an overall alerting effect, in the human brain.

  10. Factors Affecting the Consumer Purchasing Decisions of Perishable Foods: Exploring the Attitudes and the Preferences

    Directory of Open Access Journals (Sweden)

    Muhammad Rehan MASOOM

    2015-09-01

    Full Text Available The present study is designed to make a comprehensive understanding of the attitude of the urban consumers and explore the factors involved in dealing with the perishable food of certain kinds. The rise of the middle class stipulates the enhancement of the shopping environment; hence witnessing a substantial increase of the number of the supermarkets in developing countries like Bangladesh will not be surprising. A number of urban supermarkets in recent times start selling perishable foods that were once available in Bangladesh only in flea markets (Kaccha Bazaar. However, due to the lack of proper infrastructure, agro-based perishable food reaches the urban market via a long process of chain mediations and raises concerns about quality and price for both retailers and consumers. Very often the attitudes of consumers regarding perishable foods are unknown and their preferences remain unidentified. This high level of uncertainty regarding the attitude of consumers and the unpopularity regarding overall food quality need to be resolved to ensure the continuity of the business and guarantee the quality of the products. This has made the study of the consumers’ attitude towards perishable food, especially relevant for emerging economies like Bangladesh. The data is collected from one hundred (100 consumers, who buy food regularly from both super-shops and flea markets in Dhaka city. The collected data are analyzed in terms of factors like importance, expectation and perceived actual level of value to show the gap in terms of perishable foods involved.

  11. In vitro selenium accessibility in pet foods is affected by diet composition and type

    NARCIS (Netherlands)

    Zelst, van M.; Hesta, M.; Alexander, L.G.; Gray, K.; Bosch, G.; Hendriks, W.H.; Laing, Du G.; Meulenaer, de B.; Goethals, K.; Janssens, G.

    2015-01-01

    Se bioavailability in commercial pet foods has been shown to be highly variable. The aim of the present study was to identify dietary factors associated with in vitro accessibility of Se (Se Aiv) in pet foods. Se Aiv is defined as the percentage of Se from the diet that is potentially available for

  12. Commercial WWW Site Appeal: How Does It Affect Online Food and Drink Consumers' Purchasing Behavior?

    Science.gov (United States)

    White, Gregory K.; Manning, Barbara J.

    1998-01-01

    Reports on an online survey of consumer attitudes toward online storefronts marketing barbecue sauce, cheese, olive oil, potato chips, and other specialty food products. The relationship between consumer attitudes toward Web sites and the likelihood of purchase, as well as demographic factors related to online food and drink buying, are described.…

  13. Commercial WWW Site Appeal: How Does It Affect Online Food and Drink Consumers' Purchasing Behavior?

    Science.gov (United States)

    White, Gregory K.; Manning, Barbara J.

    1998-01-01

    Reports on an online survey of consumer attitudes toward online storefronts marketing barbecue sauce, cheese, olive oil, potato chips, and other specialty food products. The relationship between consumer attitudes toward Web sites and the likelihood of purchase, as well as demographic factors related to online food and drink buying, are described.…

  14. Context factors affecting design and operation of Food Safety Management Systems in the fresh produce chain

    NARCIS (Netherlands)

    Kirezieva, K.K.; Nanyunja, J.; Jacxsens, L.; Vorst, van der J.G.A.J.; Uyttendaele, M.; Luning, P.A.

    2013-01-01

    Recent food-borne outbreaks and cases of non-compliances to maximum residue limits of pesticides, indicated that food safety management systems (FSMS) in fresh produce chain are not yet performing in a satisfactory manner. However, the system output is not only dependent on the system design and ope

  15. How partial reinforcement of food cues affects the extinction and reacquisition of appetitive responses. A new model for dieting success?

    Science.gov (United States)

    van den Akker, Karolien; Havermans, Remco C; Bouton, Mark E; Jansen, Anita

    2014-10-01

    Animals and humans can easily learn to associate an initially neutral cue with food intake through classical conditioning, but extinction of learned appetitive responses can be more difficult. Intermittent or partial reinforcement of food cues causes especially persistent behaviour in animals: after exposure to such learning schedules, the decline in responding that occurs during extinction is slow. After extinction, increases in responding with renewed reinforcement of food cues (reacquisition) might be less rapid after acquisition with partial reinforcement. In humans, it may be that the eating behaviour of some individuals resembles partial reinforcement schedules to a greater extent, possibly affecting dieting success by interacting with extinction and reacquisition. Furthermore, impulsivity has been associated with less successful dieting, and this association might be explained by impulsivity affecting the learning and extinction of appetitive responses. In the present two studies, the effects of different reinforcement schedules and impulsivity on the acquisition, extinction, and reacquisition of appetitive responses were investigated in a conditioning paradigm involving food rewards in healthy humans. Overall, the results indicate both partial reinforcement schedules and, possibly, impulsivity to be associated with worse extinction performance. A new model of dieting success is proposed: learning histories and, perhaps, certain personality traits (impulsivity) can interfere with the extinction and reacquisition of appetitive responses to food cues and they may be causally related to unsuccessful dieting.

  16. Larval Survivorship and Settlement of Crown-of-Thorns Starfish (Acanthaster cf. solaris at Varying Algal Cell Densities

    Directory of Open Access Journals (Sweden)

    Morgan S. Pratchett

    2017-01-01

    Full Text Available The dispersal potential of crown-of-thorns starfish (CoTS larvae is important in understanding both the initiation and spread of population outbreaks, and is fundamentally dependent upon how long larvae can persist while still retaining the capacity to settle. This study quantified variation in larval survivorship and settlement rates for CoTS maintained at three different densities of a single-celled flagellate phytoplankton, Proteomonas sulcata (1 × 103, 1 × 104, and 1 × 105 cells/mL. Based on the larval starvation hypothesis, we expected that low to moderate levels of phytoplankton prey would significantly constrain both survival and settlement. CoTS larvae were successfully maintained for up to 50 days post-fertilization, but larval survival differed significantly between treatments. Survival was greatest at intermediate food levels (1 × 104 cells/mL, and lowest at high (1 × 105 cells/mL food levels. Rates of settlement were also highest at intermediate food levels and peaked at 22 days post-fertilization. Peak settlement was delayed at low food levels, probably reflective of delayed development, but there was no evidence of accelerated development at high chlorophyll concentrations. CoTS larvae were recorded to settle 17–43 days post-fertilization, but under optimum conditions with intermediate algal cell densities, peak settlement occurred at 22 days post-fertilization. Natural fluctuations in nutrient concentrations and food availability may affect the number of CoTS that effectively settle, but seem unlikely to influence dispersal dynamics.

  17. Food insecurity affects school children's academic performance, weight gain, and social skills.

    Science.gov (United States)

    Jyoti, Diana F; Frongillo, Edward A; Jones, Sonya J

    2005-12-01

    Food insecurity has been associated with diverse developmental consequences for U.S. children primarily from cross-sectional studies. We used longitudinal data to investigate how food insecurity over time related to changes in reading and mathematics test performance, weight and BMI, and social skills in children. Data were from the Early Childhood Longitudinal Study-Kindergarten Cohort, a prospective sample of approximately 21,000 nationally representative children entering kindergarten in 1998 and followed through 3rd grade. Food insecurity was measured by parent interview using a modification of the USDA module in which households were classified as food insecure if they reported > or =1 affirmative response in the past year. Households were grouped into 4 categories based on the temporal occurrence of food insecurity in kindergarten and 3rd grade. Children's academic performance, height, and weight were assessed directly. Children's social skills were reported by teachers. Analyses examined the effects of modified food insecurity on changes in child outcomes using lagged, dynamic, and difference (i.e., fixed-effects) models and controlling for child and household contextual variables. In lagged models, food insecurity was predictive of poor developmental trajectories in children before controlling for other variables. Food insecurity thus serves as an important marker for identifying children who fare worse in terms of subsequent development. In all models with controls, food insecurity was associated with outcomes, and associations differed by gender. This study provides the strongest empirical evidence to date that food insecurity is linked to specific developmental consequences for children, and that these consequences may be both nutritional and nonnutritional.

  18. Effects of host plant and larval density on intraspecific competition in larvae of the emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Duan, Jian J; Larson, Kristi; Watt, Tim; Gould, Juli; Lelito, Jonathan P

    2013-12-01

    Competition for food, mates, and space among different individuals of the same insect species can affect density-dependent regulation of insect abundance or population dynamics. The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of North American ash (Fraxinus spp.) trees, with its larvae feeding in serpentine galleries between the interface of sapwood and phloem tissues of ash trees. Using artificial infestation of freshly cut logs of green ash (Fraxinus pennsylvanica Marshall) and tropical ash (Fraxinus uhdei [Wenzig] Lingelsh) with a series of egg densities, we evaluated the mechanism and outcome of intraspecific competition in larvae of A. planipennis in relation to larval density and host plant species. Results from our study showed that as the egg densities on each log (1.5-6.5 cm in diameter and 22-25 cm in length) increased from 200 to 1,600 eggs per square meter of surface area, larval survivorship declined from ≍68 to 10% for the green ash logs, and 86 to 55% for tropical ash logs. Accordingly, larval mortality resulting from cannibalism, starvation, or both, significantly increased as egg density increased, and the biomass of surviving larvae significantly decreased on both ash species. When larval density was adjusted to the same level, however, larval mortality from intraspecific competition was significantly higher and mean biomasses of surviving larvae was significantly lower in green ash than in tropical ash. The role of intraspecific competition of A. planipennis larvae in density-dependent regulation of its natural population dynamics is discussed.

  19. Factors Affecting the Consumption of Fast Foods Among Women Based on the Social Cognitive Theory

    Directory of Open Access Journals (Sweden)

    Nooshin Beiranvandpour

    2014-06-01

    Full Text Available Introduction: Fast-food consumption among Iranian families appears to be increasing probably due to urbanization, popularization of western-style diets and increased women's labor force participation. Few theory-based investigations have assessed the determinants of fast food consumption. Therefore, the aim of this study was to determine the predictors of fast food consumption, based on the social cognitive theory (SCT among women referred to health centers in Hamadan, West of Iran. Materials and Methods: This cross-sectional study was conducted using structured self-administered questionnaires on 384 women referred to 10 health centers in Hamadan city, Western of Iran. Health center was considered as a sampling unit and systematic random sampling method was applied to select health centers. Participants filled a questionnaire containing SCT constructs, an eight-item food frequency questionnaire, and demographic characteristics. Data was analyzed by independent T-test, one-way ANOVA, and multiple linear regression using SPSS-16. Results: The model could explain 21% of the variance in frequency of fast food consumption. Outcome expectations (p=0.04 and availability (p< 0.001 were the significant predictors. The career status of women was the only related demographic characteristic (p< 0.001. Conclusion: Interventions aimed to change outcome expectations and introducing nutritious alternatives to fast food could be promising to decrease the rate of fast-food consumption.

  20. Kauri seeds and larval somersaults

    DEFF Research Database (Denmark)

    Dupont, Steen Thorleif

    2012-01-01

    The trunk morphology of the larvae of the kauri pine (Agathis) seed infesting moth Agathiphaga is described using conventional, polarization, and scanning electron microscopy. The pine seed chamber formed by the larva is also described and commented on. The simple larval chaetotaxy includes more...... of the minute posture sensing setae, proprioceptors, than expected from the lepidopteran larval ground plan. The excess of proprioceptors is suggested to be necessary for sensory input concerning the larval posture within the seed chamber. The trunk musculature includes an autapomorphic radial ventral...... musculature made up of unique multisegmental muscles. The combined presence of additional proprioceptors and the unique ventral musculature is proposed to be related to the larval movement within the confined space of the seed chamber, especially to a proposed somersault movement that allows the larva...

  1. Susceptibility of South Korea to Extremes Affecting the Global Food System

    Science.gov (United States)

    Chon, So Young; Puma, Michael J.

    2015-01-01

    Food security in South Korea is tightly linked to the global food system. The country's production of major grains declined from 5.8 million metric tons (mmt) in 1998 to 4.8 mmt in 2014, which caused the country's grain self suciency to decline from 31.4% to 24%. This decline is a consequence of several factors including reductions in domestic agricultural land, governmental policies supporting industry over agriculture, and a push towards trade liberalization. South Korea's self suciency is now one of the lowest among Organisation for Economic Co-operation and Development (OECD) countries, leaving it vulnerable to disruptions in the global food system.

  2. Hypothalamic-specific manipulation of Fto, the ortholog of the human obesity gene FTO, affects food intake in rats.

    Directory of Open Access Journals (Sweden)

    Yi-Chun Loraine Tung

    Full Text Available Sequence variants in the first intron of FTO are strongly associated with human obesity and human carriers of the risk alleles show evidence for increased appetite and food intake. Mice globally lacking Fto display a complex phenotype characterised by both increased energy expenditure and increased food intake. The site of action of FTO on energy balance is unclear. Fasting reduces levels of Fto mRNA in the arcuate nucleus (ARC of the hypothalamus, a site where Fto expression is particularly high. In this study, we have extended this nutritional link by demonstrating that consumption of a high fat diet (45% results in a 2.5 fold increase in Arc Fto expression. We have further explored the role of hypothalamic Fto in the control of food intake by using stereotactic injections coupled with AAV technology to bi-directionally modulate Fto expression. An over expression of Fto protein by 2.5-fold in the ARC results in a 14% decrease in average daily food intake in the first week. In contrast, knocking down Arc Fto expression by 40% increases food intake by 16%. mRNA levels of Agrp, Pomc and Npy, ARC-expressed genes classically associated with the control of food intake, were not affected by the manipulation of Fto expression. However, over expression of Fto resulted in a 4-fold increase in the mRNA levels of Stat3, a signalling molecule critical for leptin receptor signalling, suggesting a possible candidate for the mediation of Fto's actions. These data provide further support for the notion that FTO itself can influence key components of energy balance, and is therefore a strong candidate for the mediation of the robust association between FTO intronic variants and adiposity. Importantly, this provide the first indication that selective alteration of FTO levels in the hypothalamus can influence food intake, a finding consistent with the reported effects of FTO alleles on appetite and food intake in man.

  3. Timed food availability affects circadian behavior but not the neuropeptide Y expression in Indian weaverbirds exposed to atypical light environment.

    Science.gov (United States)

    Singh, Devraj; Trivedi, Neerja; Malik, Shalie; Rani, Sangeeta; Kumar, Vinod

    2016-07-01

    We tested the hypothesis whether daily food availability period would restore rhythmicity in individuals with disrupted circadian behavior with no effect on appetite regulation. Particularly, we investigated the effects of timed food availability on activity behavior, and Fos and neuropeptide Y expressions in Indian weaverbirds (Ploceus philippinus) under atypical light conditions. Initially, weaverbirds in 3 groups of 7-8 each were entrained to 7L:17D (25: food ad libitum. Thereafter, food availability was restricted for 7h such that it overlapped with the light period. After a week, 7L:17D was replaced with 3.5L: 3.5D (T7, group 1), 3.5L: 20.5D (T24, group 2) or constant dim light, LLdim (Food cycles synchronized the circadian activity behavior, albeit with group differences, but did not affect body mass, blood glucose levels or testis size. Further, Fos, not NPY mRNA or peptide, expression measured at ZT2 and ZT14 (ZT0=time of food given) showed significant group differences in the hippocampus, dorsomedial hypothalamus and infundibular nuclear complex. Another identical experiment examined after-effects of the 3 light conditions on persistence of the circadian rhythms. Weaverbirds exposed for 4weeks to identical food but different light conditions, as above, were released into the free-running condition of food ad libitum and LLdim. Circadian rhythms were decayed in birds previously exposed to T7 LD cycle. Overall, these results show that timed meal restores rhythmicity in individuals with circadian rhythm disruptions without involving neuropeptide Y, the key appetite regulatory molecule.

  4. Variables Affecting Secondary School Students' Willingness to Eat Genetically Modified Food Crops

    Science.gov (United States)

    Maes, Jasmien; Bourgonjon, Jeroen; Gheysen, Godelieve; Valcke, Martin

    2017-04-01

    A large-scale cross-sectional study (N = 4002) was set up to determine Flemish secondary school students' willingness to eat genetically modified food (WTE) and to link students' WTE to previously identified key variables from research on the acceptance of genetic modification (GM). These variables include subjective and objective knowledge about genetics and biotechnology, perceived risks and benefits of GM food crops, trust in information from different sources about GM, and food neophobia. Differences between WTE-related variables based on students' grade level, educational track, and gender were analyzed. The students displayed a rather indecisive position toward GM food and scored weakly on a genetics and biotechnology knowledge test. WTE correlated most strongly with perceived benefits and subjective and objective knowledge. The results have clear implications for education, as they reiterate the need to strengthen students' scientific knowledge base and to introduce a GM-related debate at a much earlier stage in their school career.

  5. Proteomic Analysis of Larval Midgut from the Silkworm (Bombyx mori

    Directory of Open Access Journals (Sweden)

    Sai Zhang

    2011-01-01

    Full Text Available The midgut is the major organ for food digestion, nutrient absorption and also a barrier for foreign substance. The 5th-instar larval stage of silkworm is very important for larval growth, development, and silk production. In the present study, we used 2-DE and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS to analyze the midgut proteins from the 5th-instar larvae as well as the midgut proteins under starvation condition. A total of 96 proteins were identified in this study; and among them, 69 proteins were observed in midgut for the first time. We also found that the silkworm larval midgut responded to starvation by producing a 10 kDa heat shock protein and a diapause hormone precursor.

  6. HOW LABELING OF SAFETY AND PROCESS ATTRIBUTES AFFECTS MARKETS FOR FOOD

    OpenAIRE

    Julie A Caswell

    1998-01-01

    Consumers are increasingly considering information on the safety and process (how foods are produced) attributes of food in making their buying decisions. Producers, processors, and retailers may choose voluntary labeling of these attributes, may be required to label by government regulations, or may use a combination of these approaches. The market effects depend on consumer perceptions of the attributes, the benefits and costs of labeling for companies, and the goals of government policy. T...

  7. Biofilm Matrix Composition Affects the Susceptibility of Food Associated Staphylococci to Cleaning and Disinfection Agents

    OpenAIRE

    Annette eFagerlund; Solveig eLangsrud; Even eHeir; Maria Ingeborg Mikkelsen; Trond eMøretrø

    2016-01-01

    Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride-containing disinfectants is due to biofilm formation, matrix composition or benzalkonium chloride efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2), S. cohnii, S. epidermidis, S. lentus (2), and S. saprophyticu...

  8. A guide to countermeasures for implementation in the event of a nuclear accident affecting nordic food-producing areas

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, K.G.; Roed, J. [Risoe National Lab., (Denmark); Rantavaara, A. [STUK (Finland); Rosen, K. [Swedish Univ. of Agricultural Sciences (Sweden); Salbu, B.; Skipperud, L. [Agricultural Univ. of Norway (Norway)

    2000-08-01

    State-of-the-art information on methods for management of nuclear accidents affecting food-producing areas has been reviewed, evaluated and transposed to reflect conditions relevant to the Nordic countries. This data, describing in detail the various method-specific costs and benefits, is reported in a well-arranged format facilitating analyses in connection with decision-making. Guidance, recommendations and examples are given as to how the individual data sheets may be used in emergency preparedness planning. (au)

  9. Maternal and young child nutrition adversely affected by external shocks such as increasing global food prices.

    Science.gov (United States)

    Darnton-Hill, Ian; Cogill, Bruce

    2010-01-01

    Rising food prices, resulting from the ongoing global economic crisis, fuel price volatility, and climate change, have an adverse impact upon the poor, especially those in food-importing, resource-limited countries. The conventional approach by large organizations has been to advocate for increased staple crop yields of mainly cereals. High food prices are predicted to continue to at least 2015. Past shocks and their known impacts upon nutrition were reviewed. Price instability and increases have long been an existing global problem, which has been exacerbated by recent macroeconomic shocks such as acute emergencies due to war and civil strife, acute climatic events, increase in food prices, fuel price volatility, dysfunction of the global financial systems, long-term climate change, and the emergence of failed states. The FAO estimated that there were 815 million "hungry" people in 2006, with a now additional 75-135 million with increased vulnerability, and currently it is estimated that there are one billion people at risk of food insecurity. The shocks initially compromise maternal and child nutrition, mainly through a reduction in dietary quality and an increase in micronutrient deficiencies and concomitant increases in infectious disease morbidity and mortality. A further reduction in the quantity of diet may follow with greater underweight and wasting. Recent macroeconomic shocks have greatly increased the number of people who are vulnerable to hunger in developing countries. Nutritional surveillance systems need to be strengthened and expanded to inform policy decisions.

  10. ‘Peer pressure’ in larval Drosophila?

    OpenAIRE

    Thomas Niewalda; Ines Jeske; Birgit Michels; Bertram Gerber

    2014-01-01

    ABSTRACT Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on ‘peer pressure’, that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group ...

  11. Mood modulation by food: an exploration of affect and cravings in 'chocolate addicts'.

    Science.gov (United States)

    Macdiarmid, J I; Hetherington, M M

    1995-02-01

    To test the hypothesis that some foods are eaten to alter mood, the relationship between mood and intake of chocolate was investigated in 40 women. Twenty self-identified chocolate 'addicts' and 20 controls rated hunger, mood, intensity of craving and amount of chocolate eaten in a diary for seven consecutive days. The 'addicts' reported a significantly greater number of eating episodes and consumed a larger amount of chocolate than controls. 'Addicts' also rated depression, guilt and craving higher and feeling content and relaxed as lower before eating than controls. However, eating chocolate resulted in increased feelings of guilt in the 'addicts' and no significant changes in feeling depressed or relaxed. On indices of disordered eating and depression, 'addicts' scored significantly higher than controls; however, eating chocolate did not improve mood. Although chocolate is a food which provides pleasure, for those who consider intake of this food to be excessive, any pleasure experienced is short lived and accompanied by feelings of guilt.

  12. Parasites affect food web structure primarily through increased diversity and complexity.

    Directory of Open Access Journals (Sweden)

    Jennifer A Dunne

    Full Text Available Comparative research on food web structure has revealed generalities in trophic organization, produced simple models, and allowed assessment of robustness to species loss. These studies have mostly focused on free-living species. Recent research has suggested that inclusion of parasites alters structure. We assess whether such changes in network structure result from unique roles and traits of parasites or from changes to diversity and complexity. We analyzed seven highly resolved food webs that include metazoan parasite data. Our analyses show that adding parasites usually increases link density and connectance (simple measures of complexity, particularly when including concomitant links (links from predators to parasites of their prey. However, we clarify prior claims that parasites "dominate" food web links. Although parasites can be involved in a majority of links, in most cases classic predation links outnumber classic parasitism links. Regarding network structure, observed changes in degree distributions, 14 commonly studied metrics, and link probabilities are consistent with scale-dependent changes in structure associated with changes in diversity and complexity. Parasite and free-living species thus have similar effects on these aspects of structure. However, two changes point to unique roles of parasites. First, adding parasites and concomitant links strongly alters the frequency of most motifs of interactions among three taxa, reflecting parasites' roles as resources for predators of their hosts, driven by trophic intimacy with their hosts. Second, compared to free-living consumers, many parasites' feeding niches appear broader and less contiguous, which may reflect complex life cycles and small body sizes. This study provides new insights about generic versus unique impacts of parasites on food web structure, extends the generality of food web theory, gives a more rigorous framework for assessing the impact of any species on trophic

  13. Parasites affect food web structure primarily through increased diversity and complexity

    Science.gov (United States)

    Dunne, Jennifer A.; Lafferty, Kevin D.; Dobson, Andrew P.; Hechinger, Ryan F.; Kuris, Armand M.; Martinez, Neo D.; McLaughlin, John P.; Mouritsen, Kim N.; Poulin, Robert; Reise, Karsten; Stouffer, Daniel B.; Thieltges, David W.; Williams, Richard J.; Zander, Claus Dieter

    2013-01-01

    Comparative research on food web structure has revealed generalities in trophic organization, produced simple models, and allowed assessment of robustness to species loss. These studies have mostly focused on free-living species. Recent research has suggested that inclusion of parasites alters structure. We assess whether such changes in network structure result from unique roles and traits of parasites or from changes to diversity and complexity. We analyzed seven highly resolved food webs that include metazoan parasite data. Our analyses show that adding parasites usually increases link density and connectance (simple measures of complexity), particularly when including concomitant links (links from predators to parasites of their prey). However, we clarify prior claims that parasites ‘‘dominate’’ food web links. Although parasites can be involved in a majority of links, in most cases classic predation links outnumber classic parasitism links. Regarding network structure, observed changes in degree distributions, 14 commonly studied metrics, and link probabilities are consistent with scale-dependent changes in structure associated with changes in diversity and complexity. Parasite and free-living species thus have similar effects on these aspects of structure. However, two changes point to unique roles of parasites. First, adding parasites and concomitant links strongly alters the frequency of most motifs of interactions among three taxa, reflecting parasites’ roles as resources for predators of their hosts, driven by trophic intimacy with their hosts. Second, compared to free-living consumers, many parasites’ feeding niches appear broader and less contiguous, which may reflect complex life cycles and small body sizes. This study provides new insights about generic versus unique impacts of parasites on food web structure, extends the generality of food web theory, gives a more rigorous framework for assessing the impact of any species on trophic

  14. Food availability affects the strength of mutualistic host–microbiota interactions in Daphnia magna

    Science.gov (United States)

    Callens, Martijn; Macke, Emilie; Muylaert, Koenraad; Bossier, Peter; Lievens, Bart; Waud, Michael; Decaestecker, Ellen

    2016-01-01

    The symbiotic gut microbial community is generally known to have a strong impact on the fitness of its host. Nevertheless, it is less clear how the impact of symbiotic interactions on the hosts' fitness varies according to environmental circumstances such as changes in the diet. This study aims to get a better understanding of host–microbiota interactions under different levels of food availability. We conducted experiments with the invertebrate, experimental model organism Daphnia magna and compared growth, survival and reproduction of conventionalized symbiotic Daphnia with germ-free individuals given varying quantities of food. Our experiments revealed that the relative importance of the microbiota for the hosts' fitness varied according to dietary conditions. The presence of the microbiota had strong positive effects on Daphnia when food was sufficient or abundant, but had weaker effects under food limitation. Our results indicate that the microbiota can be a potentially important factor in determining host responses to changes in dietary conditions. Characterization of the host-associated microbiota further showed that Aeromonas sp. was the most prevalent taxon in the digestive tract of Daphnia. PMID:26405832

  15. Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity

    NARCIS (Netherlands)

    Dunne, J.A.; Lafferty, K.D.; Dobson, A.P.; Hechinger, R.F.; Kuris, A.M.; Martinez, N.D.; McLaughlin, J.P.; Mouritsen, K.N.; Poulin, R.; Reise, K.; Stouffer, D.B.; Thieltges, D.W.; Williams, R.J.; Zander, C.D.

    2013-01-01

    Comparative research on food web structure has revealed generalities in trophic organization, produced simple models, and allowed assessment of robustness to species loss. These studies have mostly focused on free-living species. Recent research has suggested that inclusion of parasites alters struc

  16. Citicoline affects appetite and cortico-limbic responses to images of high-calorie foods.

    Science.gov (United States)

    Killgore, William D S; Ross, Amy J; Kamiya, Toshikazu; Kawada, Yoko; Renshaw, Perry F; Yurgelun-Todd, Deborah A

    2010-01-01

    Cytidine-5'-diphosphocholine (citicoline) has a variety of cognitive enhancing, neuroprotective, and neuroregenerative properties. In cocaine-addicted individuals, citicoline has been shown to increase brain dopamine levels and reduce cravings. The effects of this compound on appetite, food cravings, and brain responses to food are unknown. We compared the effects of treatment with Cognizin citicoline (500 mg/day versus 2,000 mg/day) for 6 weeks on changes in appetite ratings, weight, and cortico-limbic responses to images of high-calorie foods using functional magnetic resonance imaging (fMRI). After 6 weeks, there was no significant change in weight status, although significant declines in appetite ratings were observed for the 2,000 mg/day group. The higher dose group also showed significant increases in functional brain responses to food stimuli within the amygdala, insula, and lateral orbitofrontal cortex. Increased activation in these regions correlated with declines in appetite ratings. These preliminary findings suggest a potential usefulness of citicoline in modulating appetite, but further research is warranted.

  17. Citicoline Affects Appetite and Cortico-Limbic Responses to Images of High Calorie Foods

    Science.gov (United States)

    Killgore, William D. S.; Ross, Amy J.; Kamiya, Toshi; Kawada, Yoko; Renshaw, Perry F.; Yurgelun-Todd, Deborah A.

    2011-01-01

    Cytidine-5’-diphosphocholine (citicoline) has a variety of cognitive enhancing, neuroprotective, and neuroregenerative properties. In cocaine-addicted individuals, citicoline has been shown to increase brain dopamine levels and reduce cravings. The effects of this compound on appetite, food cravings, and brain responses to food are unknown. We compared the effects of treatment with citicoline (500 mg/day versus 2000 mg/day) for six weeks on changes in appetite ratings, weight, and cortico-limbic responses to images of high calorie foods using functional magnetic resonance imaging (fMRI). After six weeks, there was no significant change in weight status, although significant declines in appetite ratings were observed for the 2000 mg/day group. The higher dose group also showed significant increases in functional brain responses to food stimuli within the amygdala, insula, and lateral orbitofrontal cortex. Increased activation in these regions correlated with declines in appetite ratings. These preliminary findings suggest a potential usefulness of citicoline in modulating appetite, but further research is warranted. PMID:19260039

  18. Factors affecting the adoption of genetically modified animals in the food and pharmaceutical chains

    NARCIS (Netherlands)

    Mora, C.; Menozzi, D.; Kleter, G.A.; Aramyan, L.H.; Valeeva, N.I.; Zimmermann, K.L.; Pakky Reddy, G.

    2012-01-01

    The production of genetically modified (GM) animals is an emerging technique that could potentially impact the livestock and pharmaceutical industries. Currently, food products derived from GM animals have not yet entered the market whilst two pharmaceutical products have. The objective of this pape

  19. Factors Affecting College Students' Knowledge and Opinions of Genetically Modified Foods

    Science.gov (United States)

    Laux, Chad M.; Mosher, Gretchen A.; Freeman, Steven A.

    2010-01-01

    The use of biotechnology in food and agricultural applications has increased greatly during the past decade and is considered by many to be a controversial topic. Drawing upon a previous national study, a new survey was conducted of U.S. and international college students at a large, land-grant, Research University to determine factors that may…

  20. How parental dietary behavior and food parenting practices affect children's dietary behavior: Interacting sources of influence?

    NARCIS (Netherlands)

    Larsen, J.K.; Hermans, R.C.J.; Sleddens, E.F.C.; Engels, R.C.M.E.; Fisher, J.O.; Kremers, S.P.J.

    2015-01-01

    Until now, the literatures on the effects of food parenting practices and parents' own dietary behavior on children's dietary behavior have largely been independent from one another. Integrating findings across these areas could provide insight on simultaneous and interacting influences on

  1. Use of a test of perceived authenticity to trigger affective responses when testing food

    NARCIS (Netherlands)

    Boutrolle, I.; Delarue, J.; Köster, E.P.; Aranz, D.; Danzart, M.

    2009-01-01

    Food developers frequently check the liking for their recipes by asking consumers to state their preferences. This approach is often criticised for the lack of commitment of the participants and the artificiality of the hedonic response. This study tested whether an authenticity test could also be u

  2. Acute sleep deprivation increases portion size and affects food choice in young men.

    Science.gov (United States)

    Hogenkamp, Pleunie S; Nilsson, Emil; Nilsson, Victor C; Chapman, Colin D; Vogel, Heike; Lundberg, Lina S; Zarei, Sanaz; Cedernaes, Jonathan; Rångtell, Frida H; Broman, Jan-Erik; Dickson, Suzanne L; Brunstrom, Jeffrey M; Benedict, Christian; Schiöth, Helgi B

    2013-09-01

    Acute sleep loss increases food intake in adults. However, little is known about the influence of acute sleep loss on portion size choice, and whether this depends on both hunger state and the type of food (snack or meal item) offered to an individual. The aim of the current study was to compare portion size choice after a night of sleep and a period of nocturnal wakefulness (a condition experienced by night-shift workers, e.g. physicians and nurses). Sixteen men (age: 23 ± 0.9 years, BMI: 23.6 ± 0.6 kg/m(2)) participated in a randomized within-subject design with two conditions, 8-h of sleep and total sleep deprivation (TSD). In the morning following sleep interventions, portion size, comprising meal and snack items, was measured using a computer-based task, in both fasted and sated state. In addition, hunger as well as plasma levels of ghrelin were measured. In the morning after TSD, subjects had increased plasma ghrelin levels (13%, p=0.04), and chose larger portions (14%, p=0.02), irrespective of the type of food, as compared to the sleep condition. Self-reported hunger was also enhanced (pchoice after sleep loss depend on both an individual's hunger status, and the type of food offered. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. A Point-of-Purchase Intervention Featuring In-Person Supermarket Education Affects Healthful Food Purchases

    Science.gov (United States)

    Milliron, Brandy-Joe; Woolf, Kathleen; Appelhans, Bradley M.

    2012-01-01

    Objective: This study tested the efficacy of a multicomponent supermarket point-of-purchase intervention featuring in-person nutrition education on the nutrient composition of food purchases. Design: The design was a randomized trial comparing the intervention with usual care (no treatment). Setting and Participants: A supermarket in a…

  4. Urbanization affects water and nitrogen use in the food chain in China

    NARCIS (Netherlands)

    Qin, W.; Ma, L.; Zhang, F.S.; Oenema, O.

    2012-01-01

    ABSTRACT Urbanization and agriculture are highly coupled. However, the impacts of urbanization(e.g. transformation in urban and rural population and change in diet) on water and nitrogen (N) use remain poorly understood. The objectives of this study are to quantify water flows in the food chain of

  5. How parental dietary behavior and food parenting practices affect children's dietary behavior: Interacting sources of influence?

    NARCIS (Netherlands)

    Larsen, J.K.; Hermans, R.C.J.; Sleddens, E.F.C.; Engels, R.C.M.E.; Fisher, J.O.; Kremers, S.P.J.

    2015-01-01

    Until now, the literatures on the effects of food parenting practices and parents' own dietary behavior on children's dietary behavior have largely been independent from one another. Integrating findings across these areas could provide insight on simultaneous and interacting influences on children'

  6. Factors affecting the adoption of genetically modified animals in the food and pharmaceutical chains

    NARCIS (Netherlands)

    Mora, C.; Menozzi, D.; Kleter, G.A.; Aramyan, L.H.; Valeeva, N.I.; Zimmermann, K.L.; Pakky Reddy, G.

    2012-01-01

    The production of genetically modified (GM) animals is an emerging technique that could potentially impact the livestock and pharmaceutical industries. Currently, food products derived from GM animals have not yet entered the market whilst two pharmaceutical products have. The objective of this pape

  7. Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity

    NARCIS (Netherlands)

    Dunne, J.A.; Lafferty, K.D.; Dobson, A.P.; Hechinger, R.F.; Kuris, A.M.; Martinez, N.D.; McLaughlin, J.P.; Mouritsen, K.N.; Poulin, R.; Reise, K.; Stouffer, D.B.; Thieltges, D.W.; Williams, R.J.; Zander, C.D.

    2013-01-01

    Comparative research on food web structure has revealed generalities in trophic organization, produced simple models, and allowed assessment of robustness to species loss. These studies have mostly focused on free-living species. Recent research has suggested that inclusion of parasites alters struc

  8. Trophallaxis in filled-crop honeybees (Apis mellifera L.): food-loading time affects unloading behaviour

    Science.gov (United States)

    Wainselboim, A. J.; Farina, W. M.

    Honeybees ingested 50% w/w (1.8M) sucrose solution at a rate feeder offering either 16.5, 32.5 or 65 μl/min. While the time spent ingesting solution at the feeder decreased significantly with increasing flow of solution, bees attained maximum crop loads with this range of flows. Different parameters related to mouth-to-mouth food exchange (trophallaxis) showed important modulations as the offered flow of solution was incremented. Trophallactic transfer rate, i.e. the speed at which liquid food is transferred from donor to recipient bee, was found to increase along with increasing profitability at the rate feeder. In the present case, food source profitability could have been evaluated by foragers either by measuring the time invested in ingesting the solution, or by direct assessment of the flow rate of the feeder. Thus it seems that perception of profitability conditions at the food sourcesuffices for later representation in the hive through trophallactic contacts, independently of crop-filling state.

  9. Food availability affects the strength of mutualistic host-microbiota interactions in Daphnia magna.

    Science.gov (United States)

    Callens, Martijn; Macke, Emilie; Muylaert, Koenraad; Bossier, Peter; Lievens, Bart; Waud, Michael; Decaestecker, Ellen

    2016-04-01

    The symbiotic gut microbial community is generally known to have a strong impact on the fitness of its host. Nevertheless, it is less clear how the impact of symbiotic interactions on the hosts' fitness varies according to environmental circumstances such as changes in the diet. This study aims to get a better understanding of host-microbiota interactions under different levels of food availability. We conducted experiments with the invertebrate, experimental model organism Daphnia magna and compared growth, survival and reproduction of conventionalized symbiotic Daphnia with germ-free individuals given varying quantities of food. Our experiments revealed that the relative importance of the microbiota for the hosts' fitness varied according to dietary conditions. The presence of the microbiota had strong positive effects on Daphnia when food was sufficient or abundant, but had weaker effects under food limitation. Our results indicate that the microbiota can be a potentially important factor in determining host responses to changes in dietary conditions. Characterization of the host-associated microbiota further showed that Aeromonas sp. was the most prevalent taxon in the digestive tract of Daphnia.

  10. Metacommunity patterns in larval odonates.

    Science.gov (United States)

    McCauley, Shannon J; Davis, Christopher J; Relyea, Rick A; Yurewicz, Kerry L; Skelly, David K; Werner, Earl E

    2008-11-01

    The growth of metacommunity ecology as a subdiscipline has increased interest in how processes at different spatial scales structure communities. However, there is still a significant knowledge gap with respect to relating the action of niche- and dispersal-assembly mechanisms to observed species distributions across gradients. Surveys of the larval dragonfly community (Odonata: Anisoptera) in 57 lakes and ponds in southeast Michigan were used to evaluate hypotheses about the processes regulating community structure in this system. We considered the roles of both niche- and dispersal-assembly processes in determining patterns of species richness and composition across a habitat gradient involving changes in the extent of habitat permanence, canopy cover, area, and top predator type. We compared observed richness patterns and species distributions in this system to patterns predicted by four general community models: species sorting related to adaptive trade-offs, a developmental constraints hypothesis, dispersal assembly, and a neutral community assemblage. Our results supported neither the developmental constraints nor the neutral-assemblage models. Observed patterns of richness and species distributions were consistent with patterns expected when adaptive tradeoffs and dispersal-assembly mechanisms affect community structure. Adaptive trade-offs appeared to be important in limiting the distributions of species which segregate across the habitat gradient. However, dispersal was important in shaping the distributions of species that utilize habitats with a broad range of hydroperiods and alternative top predator types. Our results also suggest that the relative importance of these mechanisms may change across this habitat gradient and that a metacommunity perspective which incorporates both niche- and dispersal-assembly processes is necessary to understand how communities are organized.

  11. Testing efficacy of teaching food safety and identifying variables that affect learning in a low-literacy population.

    Science.gov (United States)

    Mosby, Terezie Tolar; Romero, Angélica Lissette Hernández; Linares, Ana Lucía Molina; Challinor, Julia M; Day, Sara W; Caniza, Miguela

    2015-03-01

    Nurses at a meeting of the Asociación de Hemato Oncología Pediátrica de Centroamérica y El Caribe recognized food safety as one of the main issues affecting patient care. The objective was to increase awareness of food safety issues among caregivers for pediatric cancer patients in Guatemala and El Salvador. A low-literacy booklet about food safety, "Alimentación del niño con cáncer (Feeding the child with cancer)," was developed for caregivers. Tests were developed to assess information acquisition and retention. An educator's guide was developed for consistency of education along with a demographics questionnaire. The efficacy of the booklet was tested with 162 caregivers of patients with newly diagnosed leukemia. Information retention was tested 1 and 3 months after the initial education. The booklet was found to be efficient for food safety education. There was no significant difference between post-educational knowledge in either country at 1 month or in Guatemala at 3 months. Pre-educational knowledge was not associated with any demographic variable except for self-reported ability to read in El Salvador. There was no significant association between learning ability and demographic variables in either country. Caregivers from El Salvador had a better ability to learn than caregivers from Guatemala. Education using the booklet greatly improved food safety knowledge, which remained high 1 and 3 months later. Education with the booklet was efficacious for teaching a low-literacy population about food safety. However, it is unknown which part of the education contributed to the significant improvement in knowledge.

  12. The influence of competition between foragers on clutch size decisions in an insect parasitoid with scramble larval competition

    NARCIS (Netherlands)

    Visser, M.E.

    1996-01-01

    The effect of competition between ovipositing females on their clutch size decisions is studied in animals that lay their eggs in discrete units of larval food (hosts). In such species the effect of competition depends on the form of the larval competition within such units. In insect parasitoids, t

  13. The influence of competition between foragers on clutch size decisions in an insect parasitoid with scramble larval competition

    NARCIS (Netherlands)

    Visser, M.E.

    1996-01-01

    The effect of competition between ovipositing females on their clutch size decisions is studied in animals that lay their eggs in discrete units of larval food (hosts). In such species the effect of competition depends on the form of the larval competition within such units. In insect parasitoids,

  14. Temporal Patterns of Larval Fish Occurrence in a Large Subtropical River.

    Directory of Open Access Journals (Sweden)

    Fangmin Shuai

    Full Text Available Knowledge of temporal patterns of larval fish occurrence is limited in south China, despite its ecological importance. This research examines the annual and seasonal patterns of fish larval presence in the large subtropical Pearl River. Data is based on samples collected every two days, from 2006 to 2013. In total, 45 taxa representing 13 families and eight orders were sampled. The dominant larval family was Cyprinidae, accounting for 27 taxa. Squaliobarbus curriculus was the most abundant species, followed by Megalobrama terminalis, Xenocypris davidi, Cirrhinus molitorella, Hemiculter leuscisculus and Squalidus argentatus. Fish larvae abundances varied significantly throughout the seasons (multivariate analyses: Cluster, SIMPROF and ANOSIM. The greatest numbers occurred between May and September, peaking from June through August, which corresponds to the reproductive season. In this study, redundancy analysis was used to describe the relationship between fish larval abundance and associated environmental factors. Mean water temperature, river discharge, atmospheric pressure, maximum temperature and precipitation play important roles in larval occurrence patterns. According to seasonal variations, fish larvae occurrence is mainly affected by water temperature. It was also noted that the occurrence of Salanx reevesii and Cyprinus carpio larvae is associated with higher dissolved oxygen (DO concentrations, higher atmospheric pressure and lower water temperatures which occur in the spring. On the other hand, M. terminalis, X. davidi, and C. molitorella are associated with high precipitation, high river discharge, low atmospheric pressure and low DO concentrations which featured during the summer months. S. curriculus also peaks in the summer and is associated with peak water temperatures and minimum NH3-N concentrations. Rhinogobius giurinus occur when higher atmospheric pressure, lower precipitation and lower river discharges occur in the autumn

  15. Factors Affecting Microbial Load and Profile of Potential Pathogens and Food Spoilage Bacteria from Household Kitchen Tables.

    Science.gov (United States)

    Biranjia-Hurdoyal, Susheela; Latouche, Melissa Cathleen

    2016-01-01

    The aim was to study the bacterial load and isolate potential pathogens and food spoilage bacteria from kitchen tables, including preparation tables and dining tables. Methods. A total of 53 households gave their consent for participation. The samples were collected by swabbing over an area of 5 cm by 5 cm of the tables and processed for bacterial count which was read as colony forming units (CFU), followed by isolation and identification of potential pathogens and food spoilage bacteria. Result. Knowledge about hygiene was not always put into practice. Coliforms, Enterococcus spp., Pseudomonas spp., Proteus spp., and S. aureus were detected from both dining and preparation tables. The mean CFU and presence of potential pathogens were significantly affected by the hygienic practices of the main food handler of the house, materials of kitchen tables, use of plastic covers, time of sample collection, use of multipurpose sponges/towels for cleaning, and the use of preparation tables as chopping boards (p Kitchen tables could be very important source of potential pathogens and food spoilage bacteria causing foodborne diseases. Lack of hygiene was confirmed by presence of coliforms, S. aureus, and Enterococcus spp. The use of plastic covers, multipurpose sponges, and towels should be discouraged.

  16. Time spent in home meal preparation affects energy and food group intakes among midlife women.

    Science.gov (United States)

    Chu, Yen Li; Addo, O Yaw; Perry, Courtney D; Sudo, Noriko; Reicks, Marla

    2012-04-01

    Time spent in meal preparation may be indicative of the healthfulness of meals and therefore with weight status. The purpose of this study was to examine the association between amount of time spent preparing meals and meal food group and nutrient content by meal occasion (breakfast, lunch, and dinner) among 1036 midlife women. Participants completed a 1-day food record and eating occasion questionnaires for each meal occasion. ANCOVA was used to identify possible associations. Approximately half of the participants reported spending time spent preparing breakfast was associated with lower energy and fat intakes (ptime spent preparing lunch and dinner was associated with lower vegetable and sodium intakes (ptime spent preparing meals and meal content by weight status. Nutrition education should encourage home meal preparation while stressing the selection of healthier options. The differing associations by meal occasion suggest that interventions should be tailored according to meal type. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. How changes in consumer behaviour and retailing affect competence requirements for food producers and processors

    DEFF Research Database (Denmark)

    Grunert, Klaus G.

    2006-01-01

    This paper analyses the changing competence requirements which members of the food chain face in their pursuit of competitive advantage. Two groups of trends serve as point of departure: more dynamic and heterogeneous consumer demands, which can be analysed in terms of consumer demands for sensory......, health, process and convenience qualities, and changing roles for retailers in the food chain. Based on these trends, it is argued that competencies which can increase producers' level of market orientation get increased weight in the attainment of competitive advantage, and three types of competencies...... are singled out as especially important: consumer understanding, relationship management, and new product development. The development of market-related competencies aimed at exploiting trends in consumer behaviour and retailing will also entail changing forms of cooperation among members of the value chain...

  18. How changes in consumer behaviour and retailing affect competence requirements for food producers and processors

    DEFF Research Database (Denmark)

    Grunert, Klaus G.

    This paper analyses the changing competence requirements which members of the food chain face in their pursuit of competitive advantage. Two groups of trends serve as point of departure: more dynamic and heterogeneous consumer demands, which can be analysed in terms of consumer demands for sensory......, health, process and convenience qualities, and changing roles for retailers in the food chain. Based on these trends, it is argued that competencies which can increase producers' level of market orientation get increased weight in the attainment of competitive advantage, and three types of competencies...... are singled out as especially important: consumer understanding, relationship management, and new product development. The development of market-related competencies aimed at exploiting trends in consumer behaviour and retailing will also entail changing forms of cooperation among members of the value chain...

  19. Larval transport simulation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this study is to understand how oceanographic factors affect the annual recruitment success of gag grouper. We use the Connectivity Modeling System...

  20. How does profitability get affected by working capital management in food and beverages industry?

    OpenAIRE

    Thapa, Priya Darshini Pun

    2013-01-01

    This study examines the working capital management of the Food and Beverage Corporations from the U.S.A. and Canada during the 10 years study period from year 2000 to 2009. Firstly, unlike previous studies which advocate a linear relationship between the working capital management and profitability, it investigates the existence of a possible non-linear relationship. Secondly, the efficiency of working capital management was checked using performance index, utilization index and efficiency in...

  1. Nutrient Enrichment and Food Web Composition Affect Ecosystem Metabolism in an Experimental Seagrass Habitat

    Science.gov (United States)

    Spivak, Amanda C.; Canuel, Elizabeth A.; Duffy, J. Emmett; Richardson, J. Paul

    2009-01-01

    Background Food web composition and resource levels can influence ecosystem properties such as productivity and elemental cycles. In particular, herbivores occupy a central place in food webs as the species richness and composition of this trophic level may simultaneously influence the transmission of resource and predator effects to higher and lower trophic levels, respectively. Yet, these interactions are poorly understood. Methodology/Principal Findings Using an experimental seagrass mesocosm system, we factorially manipulated water column nutrient concentrations, food chain length, and diversity of crustacean grazers to address two questions: (1) Does food web composition modulate the effects of nutrient enrichment on plant and grazer biomasses and stoichiometry? (2) Do ecosystem fluxes of dissolved oxygen and nutrients more closely reflect above-ground biomass and community structure or sediment processes? Nutrient enrichment and grazer presence generally had strong effects on biomass accumulation, stoichiometry, and ecosystem fluxes, whereas predator effects were weaker or absent. Nutrient enrichment had little effect on producer biomass or net ecosystem production but strongly increased seagrass nutrient content, ecosystem flux rates, and grazer secondary production, suggesting that enhanced production was efficiently transferred from producers to herbivores. Gross ecosystem production (oxygen evolution) correlated positively with above-ground plant biomass, whereas inorganic nutrient fluxes were unrelated to plant or grazer biomasses, suggesting dominance by sediment microbial processes. Finally, grazer richness significantly stabilized ecosystem processes, as predators decreased ecosystem production and respiration only in the zero- and one- species grazer treatments. Conclusions/Significance Overall, our results indicate that consumer presence and species composition strongly influence ecosystem responses to nutrient enrichment, and that increasing

  2. Ghrelin affects stopover decisions and food intake in a long-distance migrant

    OpenAIRE

    Goymann, Wolfgang; Lupi, Sara; Kaiya, Hiroyuki; Cardinale, Massimiliano; Fusani, Leonida

    2017-01-01

    Twice a year, billions of birds migrate across continents. Along their route, most species spend considerable time at stopover sites to replenish their fuel stores. What physiological signals tell them when they are ready to continue their journey? Ghrelin is a recently discovered hormone involved in appetite regulation. We found that ghrelin concentrations correlated positively with fat stores of wild garden warblers. Further, birds injected with ghrelin decreased their food intake and incre...

  3. Urbanization affects water and nitrogen use in the food chain in China

    OpenAIRE

    Qin, W.; Ma, L.; Zhang, F. S.; Oenema, O

    2012-01-01

    ABSTRACT Urbanization and agriculture are highly coupled. However, the impacts of urbanization(e.g. transformation in urban and rural population and change in diet) on water and nitrogen (N) use remain poorly understood. The objectives of this study are to quantify water flows in the food chain of China, to analyze the complex relationship between urbanization and water and N use efficiency, and to project water and N demand in China via various scenarios, using a combination of water footpri...

  4. Multiscale structures of lipids in foods as parameters affecting fatty acid bioavailability and lipid metabolism.

    Science.gov (United States)

    Michalski, M C; Genot, C; Gayet, C; Lopez, C; Fine, F; Joffre, F; Vendeuvre, J L; Bouvier, J; Chardigny, J M; Raynal-Ljutovac, K

    2013-10-01

    On a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen.

  5. Hypoallergenic legume crops and food allergy: factors affecting feasibility and risk.

    Science.gov (United States)

    Riascos, John J; Weissinger, Arthur K; Weissinger, Sandra M; Burks, A Wesley

    2010-01-13

    Currently, the sole strategy for managing food hypersensitivity involves strict avoidance of the trigger. Several alternate strategies for the treatment of food allergies are currently under study. Also being explored is the process of eliminating allergenic proteins from crop plants. Legumes are a rich source of protein and are an essential component of the human diet. Unfortunately, legumes, including soybean and peanut, are also common sources of food allergens. Four protein families and superfamilies account for the majority of legume allergens, which include storage proteins of seeds (cupins and prolamins), profilins, and the larger group of pathogenesis-related proteins. Two strategies have been used to produce hypoallergenic legume crops: (1) germplasm lines are screened for the absence or reduced content of specific allergenic proteins and (2) genetic transformation is used to silence native genes encoding allergenic proteins. Both approaches have been successful in producing cultivars of soybeans and peanuts with reduced allergenic proteins. However, it is unknown whether the cultivars are actually hypoallergenic to those with sensitivity. This review describes efforts to produce hypoallergenic cultivars of soybean and peanut and discusses the challenges that need to be overcome before such products could be available in the marketplace.

  6. An experimental study on fermentative H₂ production from food waste as affected by pH.

    Science.gov (United States)

    Cappai, G; De Gioannis, G; Friargiu, M; Massi, E; Muntoni, A; Polettini, A; Pomi, R; Spiga, D

    2014-08-01

    Batch dark fermentation experiments were performed on food waste and mixtures of food waste and wastewater activated sludge to evaluate the influence of pH on biological H2 production and compare the process performance with and without inoculum addition. The effect of a preliminary thermal shock treatment of the inoculum was also investigated as a means to harvest the hydrogenogenic biomass. The best performance in terms of both H2 generation potential and process kinetics was observed at pH=6.5 under all experimental conditions (no inoculum, and untreated or thermally treated inoculum added). H2 production from food waste was found to be feasible even without inoculum addition, although thermal pre-treatment of the inoculum notably increased the maximum production and reduced the lag phase duration. The analysis of the fermentation products indicated that the biological hydrogen production could be mainly ascribed to a mixed acetate/butyrate-type fermentation. However, the presence of additional metabolites in the digestate, including propionate and ethanol, also indicated that other metabolic pathways were active during the process, reducing substrate conversion into hydrogen. The plateau in H2 generation was found to mirror the condition at which soluble carbohydrates were depleted. Beyond this condition, homoacetogenesis probably started to play a role in the degradation process.

  7. The food matrix affects the anthocyanin profile of fortified egg and dairy matrices during processing and in vitro digestion.

    Science.gov (United States)

    Pineda-Vadillo, Carlos; Nau, Françoise; Guerin-Dubiard, Catherin; Jardin, Julien; Lechevalier, Valérie; Sanz-Buenhombre, Marisa; Guadarrama, Alberto; Tóth, Tamás; Csavajda, Éva; Hingyi, Hajnalka; Karakaya, Sibel; Sibakov, Juhani; Capozzi, Francesco; Bordoni, Alessandra; Dupont, Didier

    2017-01-01

    The aim of the present study was to understand to what extent the inclusion of anthocyanins into dairy and egg matrices could affect their stability after processing and their release and solubility during digestion. For this purpose, individual and total anthocyanin content of four different enriched matrices, namely custard dessert, milkshake, pancake and omelettete, was determined after their manufacturing and during in vitro digestion. Results showed that anthocyanin recovery after processing largely varied among matrices, mainly due to the treatments applied and the interactions developed with other food components. In terms of digestion, the present study showed that the inclusion of anthocyanins into food matrices could be an effective way to protect them against intestinal degradation, and also the incorporation of anthocyanins into matrices with different compositions and structures could represent an interesting and effective method to control the delivery of anthocyanins within the different compartments of the digestive tract.

  8. Analysis of the Factors Affecting Consumer’s Some Traditional Food Products Preferences by Multidimensional Scaling Method

    Directory of Open Access Journals (Sweden)

    Y. Oraman G. Unakıtan E. Yılmaz B. Başaran

    2011-01-01

    Full Text Available The aim of this study is to evaluate consumer behaviour towards factors affecting purchase decision of some traditional food products and grouping those consumer attitudes. The original data was obtained from results of a survey conducted in 14 different districts in Tekirdag. The survey consisted of face-to-face interviews conducted within a total sample of 166 households randomly. In the study, multidimensional scaling analysis is used for evaluating the effective factors of consumer preferences for traditional products and grouping their preferences. It is found that taste, food safety and freshness have similar effects on consumer preferences for yogurt, molasses and noodles. Price has an important and positive loaded effect on other variables for the three products.

  9. Interactions between introduced trout and larval salamanders (Ambystoma macrodactylum) in high-elevation lakes

    Science.gov (United States)

    Tyler, T.; Liss, W.J.; Ganio, L.; Larson, Gary L.; Hoffman, Robert L.; Deimling, E.; Lomnicky, G.A.

    1998-01-01

    The larval stage of the long-toed salamander (Ambystoma macrodactylum) is the top vertebrate predator in high-elevation fishless lakes in the North Cascades National Park Service Complex, Washington (U.S.A.). Although most of these high-elevation lakes were naturally fishless, trout have been stocked in many of them. We sought to determine the effects of physicochemical factors and introduced trout on abundance and behavior of A. macrodactylum larvae. Larval salamander densities were estimated by snorkeling. Snorkelers carefully searched through substrate materials within 2 m of the shoreline and recorded the number of larvae observed and if larvae were hidden in benthic substrates. Physicochemical factors were measured in each lake on the same day that snorkel surveys were conducted. In fishless lakes, larval salamander densities were positively related to total Kjeldahl-N concentration and negatively related to lake elevation. Crustacean zooplankton, especially cladocerans, were important food resources for larval A. macrodactylum. Crustacean zooplankton and cladoceran densities were positively related to total Kjeldahl-N, suggesting that increased food resources contributed to increased densities of larval A. macrodactylum. Differences in larval salamander densities between fish and fishless lakes were related to total Kjeldahl-N concentrations and the reproductive status of trout. Mean larval salamander densities for fishless lakes with total Kjeldahl-N amphibians requires an understanding of natural abiotic and biotic factors and processes influencing amphibian distribution and abundance.

  10. How changes in consumer behaviour and retailing affect competence requirements for food producers and processors

    DEFF Research Database (Denmark)

    Grunert, Klaus G.

    are singled out as especially important: consumer understanding, relationship management, and new product development. The development of market-related competencies aimed at exploiting trends in consumer behaviour and retailing will also entail changing forms of cooperation among members of the value chain......This paper analyses the changing competence requirements which members of the food chain face in their pursuit of competitive advantage. Two groups of trends serve as point of departure: more dynamic and heterogeneous consumer demands, which can be analysed in terms of consumer demands for sensory......, which favour both new ways of adding value but also new ways of matching consumer heterogeneity with heterogeneity in agricultural raw materials....

  11. How changes in consumer behaviour and retailing affect competence requirements for food producers and processors

    DEFF Research Database (Denmark)

    Grunert, Klaus G.

    2006-01-01

    are singled out as especially important: consumer understanding, relationship management, and new product development. The development of market-related competencies aimed at exploiting trends in consumer behaviour and retailing will also entail changing forms of cooperation among members of the value chain......This paper analyses the changing competence requirements which members of the food chain face in their pursuit of competitive advantage. Two groups of trends serve as point of departure: more dynamic and heterogeneous consumer demands, which can be analysed in terms of consumer demands for sensory......, which favour both new ways of adding value but also new ways of matching consumer heterogeneity with heterogeneity in agricultural raw materials....

  12. Effects of beach morphology and waves on onshore larval transport

    Science.gov (United States)

    Fujimura, A.; Reniers, A.; Paris, C. B.; Shanks, A.; MacMahan, J.; Morgan, S.

    2015-12-01

    Larvae of intertidal species grow offshore, and migrate back to the shore when they are ready to settle on their adult substrates. In order to reach the habitat, they must cross the surf zone, which is characterized as a semi-permeable barrier. This is accomplished through physical forcing (i.e., waves and current) as well as their own behavior. Two possible scenarios of onshore larval transport are proposed: Negatively buoyant larvae stay in the bottom boundary layer because of turbulence-dependent sinking behavior, and are carried toward the shore by streaming of the bottom boundary layer; positively buoyant larvae move to the shore during onshore wind events, and sink to the bottom once they encounter high turbulence (i.e., surf zone edge), where they are carried by the bottom current toward the shore (Fujimura et al. 2014). Our biophysical Lagrangian particle tracking model helps to explain how beach morphology and wave conditions affect larval distribution patterns and abundance. Model results and field observations show that larval abundance in the surf zone is higher at mildly sloped, rip-channeled beaches than at steep pocket beaches. Beach attributes are broken up to examine which and how beach configuration factors affect larval abundance. Modeling with alongshore uniform beaches with variable slopes reveal that larval populations in the surf zone are negatively correlated with beach steepness. Alongshore variability enhances onshore larval transport because of increased cross-shore water exchange by rip currents. Wave groups produce transient rip currents and enhance cross-shore exchange. Effects of other wave components, such as wave height and breaking wave rollers are also considered.

  13. Antioxidant properties of certain cereals as affected by food-grade bacteria fermentation.

    Science.gov (United States)

    Wang, Chung-Yi; Wu, Sz-Jie; Shyu, Yuan-Tay

    2014-04-01

    The effects of fermentation by 2 food-grade bacteria (Bacillus subtilis and Lactobacillus plantarum) on antioxidant activities and the contents of phenolics and flavonoids in 4 cereals (specifically adlay, chestnut, lotus seed, and walnut) were determined and compared with those of their non-fermented counterparts. Results showed that antioxidant properties observed in the fermented and non-fermented cereals may vary with fermented starters. Fermentation was observed to increase the phenolic and flavonoid contents of the extracts. The effects on Bacillus-fermented cereals were stronger than on Lactobacillus-fermented cereals. In IC50 values (mg/mL) of extracts, the extracts of fermented cereal showed a stronger DPPH radical scavenging and ferric-reducing activities. Fermentation did not significantly alter the Fe(2+)-chelating activity in the extracts of chestnuts and lotus seeds. All cereals were shown significantly inhibited the production of LPS-induced intracellular reactive oxygen species (ROS) without creating obvious cytotoxic effects in the macrophage cells. These results suggest that the fermentation process enables cereal-based foods with enhanced antioxidant capacities to contribute to health and nutritional improvements in consumers.

  14. "Healthy," "diet," or "hedonic". How nutrition claims affect food-related perceptions and intake?

    Science.gov (United States)

    Gravel, Karine; Doucet, Éric; Herman, C Peter; Pomerleau, Sonia; Bourlaud, Anne-Sophie; Provencher, Véronique

    2012-12-01

    The main purpose of this study was to investigate the impact of nutrition claims on food perceptions and intake among adult men and women, during ad libitum snacks. In a three (healthy vs. diet vs. hedonic) by two (normal-weight vs. overweight/obese) by two (unrestrained vs. restrained eaters) factorial design, 164 men and 188 women were invited to taste and rate oatmeal-raisin cookies. Despite the fact that the cookies were the same in all conditions, they were perceived as being healthier in the "healthy" condition than in the "diet" and "hedonic" conditions. The caloric content was estimated as higher by participants in the "hedonic" than in the "healthy" condition, by women than by men, and by restrained than by unrestrained eaters. Although measured ad libitum cookie intake did not differ as a function of experimental condition, overweight restrained men ate more than did women from each BMI and restraint category. Conversely, overweight restrained women ate less than did men from each BMI and restraint category. In conclusion, our manipulations of healthiness and "fatteningness" of food were effective in changing perceptions, but were not in changing behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Strengthened currents override the effect of warming on lobster larval dispersal and survival

    NARCIS (Netherlands)

    Cetina-Heredia, Paulina; Roughan, Moninya; van Sebille, Erik|info:eu-repo/dai/nl/304831921; Feng, Ming; Coleman, Melinda A.

    2015-01-01

    Human-induced climate change is projected to increase ocean temperature and modify circulation patterns, with potential widespread implications for the transport and survival of planktonic larvae of marine organisms. Circulation affects the dispersal of larvae, whereas temperature impacts larval

  16. Food industry workers' attitudes on the importance of factors affecting foodstuff quality managament

    Directory of Open Access Journals (Sweden)

    Antić Zorana

    2015-01-01

    Full Text Available The food industry is faced with several challenges at the same time: to supply safe and affordable foodstuff in sufficient quantity; to provide products in conditions where demand surpasses the human population growth; to operate in circumstances of ever-increasing competition; to protect the environment and respond to the population's public health concerns. An organization's success depends on the knowledge, skills, creativity and motivation of the company's workers and partners. Focus on its employees enables a company's development and improvement, whereas business ethics ensures public health and safety protection, environmental protection and life quality improvement. The company management's responsibility lies foremost in education, worker training and development, thus enabling a direct and indirect influence on the foodstuff quality and satisfying consumer requests in terms of foodstuff quality characteristics.

  17. Proteolytic activity of beef luncheon fungi as affected by incorporation of some food preservatives.

    Science.gov (United States)

    Saleem, A; El-Said, A H M

    2009-12-01

    Screening of thirty-one fungal isolates (representing 16 genera, 28 species and 3 varieties) collected from beef luncheon meat for their abilities to produce protease enzyme revealed that eleven isolates (35.48%) exhibited high protease production. However, fifteen isolates (48.39%) had moderate ability and 5 isolates (16.13%) were low producers. Aspergillus flavus, Gibberella fujikuroi and Penicillium chrysogenum were the most active producers of protease. The incorporation of five chemical substances used as food preservatives (disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium for protease production exhibited depressive effect on protease production as well as on mycelial growth of Aspergillus flavus, Gibberella fujikuroi and Penicillium chrysogenum , except in few cases the mycelial growth of A. flavus and G. fujikuroi was increased by the lowest concentration (100 ppm) of sodium benzoate, citric acid and disodium phosphate.

  18. Energy and macronutrient composition of breakfast affect gastric emptying of lunch and subsequent food intake, satiety and satiation.

    Science.gov (United States)

    Clegg, Miriam; Shafat, Amir

    2010-06-01

    Satiety and food intake are closely related to gastrointestinal transit and specifically gastric emptying. High-fat (HF) meals empty more slowly from the stomach yet are less satiating than isoenergetic low-fat (LF) meals. The current study examines how gastric emptying and satiety at lunch are affected by energy and macronutrient content of breakfast. Nine male volunteers consumed either (1) a HF breakfast, (2) a LF breakfast isoenergetic to HF (LFE) or (3) a LF breakfast of equal mass to HF (LFM). Gastric emptying half time measured using the sodium [(13)C] acetate breath test was delayed after HF compared to LF meals (HF: 102 + or - 11, LFE: 96 + or - 13, LFM: 95 + or - 13 min, mean + or - SD). Fullness increased and desire to eat decreased following the LFE breakfast measured using visual analogue scales. Eating a HF breakfast increased the energy, fat and protein from an ad libitum buffet meal given 4h after lunch. In conclusion, eating a HF breakfast delayed gastric emptying of lunch and increased food intake 7 h later compared to a LFM breakfast. These data suggest both mass and energy content of food regulate subsequent appetite and feeding and demonstrate the hyperphagic effect of a single HF meal.

  19. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Prolonged protein deprivation, but not food restriction, affects parvalbumin-containing interneurons in the dentate gyrus of adult rats.

    Science.gov (United States)

    Cardoso, Armando; Castro, João Paulo; Pereira, Pedro Alberto; Andrade, José Paulo

    2013-07-19

    Several studies have demonstrated the vulnerability of the hippocampal formation to malnutrition. In this study, we compared the effects of food restriction and protein malnutrition in the total number of neurons of the dentate gyrus and in the number of parvalbumin-immunoreactive (PV-IR) interneurons, which are related to the control of calcium homeostasis and fine tuning of the hippocampal circuits. Two month-old rats were randomly assigned to control, food-restricted and low-protein diet groups. After 6 months, 10 rats from the low-protein diet group were selected at random and fed with a normal protein diet for 2 months. The total number of granule and hilar cells was reduced in protein-deprived rats and the nutritional reestablishment with a normal protein diet did not recover neuron numbers. Protein deprivation increased the number of PV-IR interneurons in the granule cell layer and hilus, but their number returned to values similar to controls after nutritional rehabilitation. Food restriction did not affect the total number of neurons or the density of PV-IR interneurons in the dentate gyrus. These results support the view that protein deprivation may disturb calcium homeostasis, leading to neuronal death. The up-regulation of PV-IR cells may reflect a protective mechanism to counteract the calcium overload and protect the remaining neurons of the dentate gyrus. This imbalance in cell-ratio favoring GABAergic interneurons may justify some learning and memory impairments described in protein-deprived animals. This contrast between the results of food restriction and protein deprivation should be further analyzed in future studies.

  1. Lycopene from two food sources does not affect antioxidant or cholesterol status of middle-aged adults

    Directory of Open Access Journals (Sweden)

    Baker RA

    2004-09-01

    Full Text Available Abstract Background Epidemiological studies have reported associations between reduced cardiovascular disease and diets rich in tomato and/or lycopene. Intervention studies have shown that lycopene-containing foods may reduce cholesterol levels and lipid peroxidation, factors implicated in the initiation of cardiovascular disease. The objective of this study was to determine whether consumption of lycopene rich foods conferred cardiovascular protection to middle-aged adults as indicated by plasma lipid concentrations and measures of ex vivo antioxidants. Methods Ten healthy men and women consumed a low lycopene diet with no added lycopene (control treatment or supplemented with watermelon or tomato juice each containing 20 mg lycopene. Subjects consumed each treatment for three weeks in a crossover design. Plasma, collected weekly was analyzed for total cholesterol, high density lipoprotein cholesterol (HDL-C and triglyceride concentrations and for the antioxidant biomarkers of malondialdehyde formation products (MDA, plasma glutathione peroxidase (GPX and ferric reducing ability of plasma (FRAP. Data were analyzed using Proc Mixed Procedure and associations between antioxidant and lipid measures were identified by Pearson's product moment correlation analysis. Results Compared to the control diet, the lycopene-containing foods did not affect plasma lipid concentrations or antioxidant biomarkers. Women had higher total cholesterol, HDL-C and triglyceride concentrations than did the men. Total cholesterol was positively correlated to MDA and FRAP while HDL-C was positively correlated to MDA and GPX. GPX was negatively correlated to triglyceride concentration. Conclusions The inclusion of watermelon or tomato juice containing 20 mg lycopene did not affect plasma lipid concentrations or antioxidant status of healthy subjects. However, plasma cholesterol levels impacted the results of MDA and FRAP antioxidant tests.

  2. Food-web composition affects cross-ecosystem interactions and subsidies

    OpenAIRE

    2010-01-01

    P>1. Ecosystems may affect each other through trophic interactions that cross ecosystem boundaries as well as via the transfer of subsidies, but these effects can vary depending on the identity of species involved in the interaction.2. In this study, we manipulated two terrestrial bromeliad-living spider species (Aglaoctenus castaneus, Corinna gr. rubripes) that have variable hunting modes, to test their individual and combined effects on aquatic invertebrate community structure and ecosystem...

  3. Estimating of larval stadia of West Indian sweetpotato weevil Euscepes postfasciatus (Fairmaire) developed in the artificial larval diet by measuring larval head widths.

    OpenAIRE

    下地, 幸夫; Shimoji, Yukio; 琉球産経株式会社

    2003-01-01

    The survey conducted by measuring larval head widths of West Indian sweetpotato weevil Euscepes postfasciatus developed in the artificial larval diet revealed that there were five larval stadia in the developmental period. The result of this experiment can be used to estimate the larval stadia approximately in the artificial larval diet.

  4. Foraging mode affects the evolution of egg size in generalist predators embedded in complex food webs.

    Science.gov (United States)

    Verdeny-Vilalta, O; Fox, C W; Wise, D H; Moya-Laraño, J

    2015-06-01

    Ecological networks incorporate myriad biotic interactions that determine the selection pressures experienced by the embedded populations. We argue that within food webs, the negative scaling of abundance with body mass and foraging theory predict that the selective advantages of larger egg size should be smaller for sit-and-wait than active-hunting generalist predators, leading to the evolution of a difference in egg size between them. Because body mass usually scales negatively with predator abundance and constrains predation rate, slightly increasing egg mass should simultaneously allow offspring to feed on more prey and escape from more predators. However, the benefits of larger offspring would be relatively smaller for sit-and-wait predators because (i) due to their lower mobility, encounters with other predators are less common, and (ii) they usually employ a set of alternative hunting strategies that help to subdue relatively larger prey. On the other hand, for active predators, which need to confront prey as they find them, body-size differences may be more important in subduing prey. This difference in benefits should lead to the evolution of larger egg sizes in active-hunting relative to sit-and-wait predators. This prediction was confirmed by a phylogenetically controlled analysis of 268 spider species, supporting the view that the structure of ecological networks may serve to predict relevant selective pressures acting on key life history traits.

  5. Acrylamide in Japanese processed foods and factors affecting acrylamide level in potato chips and tea.

    Science.gov (United States)

    Yoshida, Mitsuru; Ono, Hiroshi; Chuda, Yoshihiro; Yada, Hiroshi; Ohnishi-Kameyama, Mayumi; Kobayashi, Hidetaka; Ohara-Takada, Akiko; Matsuura-Endo, Chie; Mori, Motoyuki; Hayashi, Nobuyuki; Yamaguchi, Yuichi

    2005-01-01

    Acrylamide concentrations in processed foods sold in Japanese markets were analyzed by LC-MS/MS and GC-MS methods. Most potato chips and whole potato-based fried snacks showed acrylamide concentration higher than 1000 microg/kg. The concentrations in non-whole potato based Japanese snacks, including rice crackers and candied sweet potatoes, were less tha. 350 microg/kg. Those in instant precooked noodles were less than 100 microg/kg with only one exception. The effect of storage condition of potato tubers on acrylamide concentration in potato chips after frying was also investigated. Sugar content in the tubers increased during cold storage, and the acrylamide concentration increased accordingly. The concentrations of asparagine and other amino acids, however, did not change during the cold storage. High correlations were observed between the acrylamide content in the chips and glucose and fructose contents in the tubers. This fact indicated that the limiting factor for acrylamide formation in potato chips is reducing sugar, not asparagine content in the tubers. Effects of roasting time and temperature on acrylamide concentration in roasted green tea are also described.

  6. Environmental factors limiting fertilisation and larval success in corals

    Science.gov (United States)

    Woods, Rachael M.; Baird, Andrew H.; Mizerek, Toni L.; Madin, Joshua S.

    2016-12-01

    Events in the early life history of reef-building corals, including fertilisation and larval survival, are susceptible to changes in the chemical and physical properties of sea water. Quantifying how changes in water quality affect these events is therefore important for understanding and predicting population establishment in novel and changing environments. A review of the literature identified that levels of salinity, temperature, pH, suspended sediment, nutrients and heavy metals affect coral early life-history stages to various degrees. In this study, we combined published experimental data to determine the relative importance of sea water properties for coral fertilisation success and larval survivorship. Of the water properties manipulated in experiments, fertilisation success was most sensitive to suspended sediment, copper, salinity, phosphate and ammonium. Larval survivorship was sensitive to copper, lead and salinity. A combined model was developed that estimated the joint probability of both fertilisation and larval survivorship in sea water with different chemical and physical properties. We demonstrated the combined model using water samples from Sydney and Lizard Island in Australia to estimate the likelihood of larvae surviving through both stages of development to settlement competency. Our combined model could be used to recommend targets for water quality in coastal waterways as well as to predict the potential for species to expand their geographical ranges in response to climate change.

  7. Stretch-activated cation channel from larval bullfrog skin

    DEFF Research Database (Denmark)

    Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

    2010-01-01

    Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed...... was markedly reduced with N-methyl-D-glucamide (NMDG)-Cl Ringer's solution in the pipette. Neither amiloride nor ATP, which are known to stimulate an apical cation channel in Ussing chamber preparations of larval frog skin, produced channel activation nor did these compounds affect the response to suction....... Stretch activation was not affected by varying the pipette concentrations of Ca(2+) between 0 mmol l(-1) and 4 mmol l(-1) or by varying pH between 6.8 and 8.0. However, conductance was reduced with 4 mmol l(-1) Ca(2+). Western blot analysis of membrane homogenates from larval bullfrog and larval toad skin...

  8. Application of X-ray microscopy in food science investigation of high pressure affected bacterial spores

    Science.gov (United States)

    Mönch, Susanne; Heinz, Volker; Guttmann, Peter; Knorr, Dietrich

    2000-05-01

    Using the Göttingen transmission X-ray microscope at BESSY the effect of different pressure and temperature levels during the high hydrostatic pressure (HP) treatment was investigated. At 150 MPa and temperatures up to 50 °C the triggering of germination was observed by standard microbiological methods with Bacillus subtilis spores. Increasing the temperature to 70 °C at the same pressure level killed the spores without any indication of germination. By X-ray microscopy images it could be shown that the typical disintegration of the protoplast is inhibited. This suggests that the enzymic reaction pathway is possibly affected under specific pressure temperature conditions.

  9. Correlated evolution between mode of larval development and habitat in muricid gastropods.

    Science.gov (United States)

    Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

    2014-01-01

    Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids gastropods.

  10. Correlated evolution between mode of larval development and habitat in muricid gastropods.

    Directory of Open Access Journals (Sweden)

    Paula Pappalardo

    Full Text Available Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule, which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in

  11. Utilization of larval and pupal detritus by Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Bara, J J; Clark, T M; Remold, S K

    2014-06-01

    The utilization of detritus sources by mosquito larvae during development may significantly affect adult life history traits and mosquito population growth. Many studies have shown invertebrate carcasses to be an important detritus source in larval habitats, but little is known regarding how invertebrate carcasses are utilized by mosquito larvae. We conducted two studies to investigate the rate of detritus consumption and its effect on larval development and life history traits. Overall, we found that Aedes aegypti and Aedes albopictus larvae rapidly consumed larval detritus, while pupal detritus was consumed at a significantly slower rate. We also found that the consumption of larval detritus significantly increased larval survivorship and decreased male development time but did not significantly influence female development time or pupal cephalothorax length for either sex. Our results suggest that the direct consumption of larval detritus can support the production of adults in larval habitats that lack allochthonous detritus inputs or where such organic inputs are insufficient. These studies indicate that different forms of invertebrate detritus are utilized in distinct ways by mosquito larvae, and therefore different forms of invertebrate detritus may have distinct effects on larval development and adult life history traits. © 2014 The Society for Vector Ecology.

  12. Biological Strategies of Dermestes maculatus DeGeer (Coleoptera: Dermestidae) at Larval Stages in Different Temperatures.

    Science.gov (United States)

    Zanetti, N I; Visciarelli, E C; Centeno, N D

    2016-12-01

    The intraspecific variation in larval instars is a widely distributed phenomenon amongst holometabolous insects. Several factors can affect the number of instars, such as temperature, humidity, and density. Only a few references could be found in the literature because the invariability in the number of larval instars is considered normal, and the issue has raised little to no interest. Despite this, no study to date has intended to assess or focus on the larval development. Here, we analyzed the effect of different rearing temperature on the larval stage of Dermestes maculatus DeGeer (Coleoptera: Dermestidae). The results indicated that at all temperatures, L5 represented a decisive point for individuals as well as the other later larval instars, because the next step to follow was to pupate or molt to the next larval instar. Furthermore, there were mainly two populations, L5 and L6, although in different proportions according to temperature. We also found that at a greater number of instars, the larval development at all temperatures lasted longer. Moreover, the exponential model was the best adjustment in the developmental time of all populations as well as for the accumulated developmental time of L1-L4. Thus, we conclude that random factors such as genetics could probably cause interspecific variability in D. maculatus larval development.

  13. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

  14. Bone quality is affected by food restriction and by nutrition-induced catch-up growth.

    Science.gov (United States)

    Pando, Rakefet; Masarwi, Majdi; Shtaif, Biana; Idelevich, Anna; Monsonego-Ornan, Efrat; Shahar, Ron; Phillip, Moshe; Gat-Yablonski, Galia

    2014-12-01

    Growth stunting constitutes the most common effect of malnutrition. When the primary cause of malnutrition is resolved, catch-up (CU) growth usually occurs. In this study, we have explored the effect of food restriction (RES) and refeeding on bone structure and mechanical properties. Sprague-Dawley male rats aged 24 days were subjected to 10 days of 40% RES, followed by refeeding for 1 (CU) or 26 days long-term CU (LTCU). The rats fed ad libitum served as controls. The growth plates were measured, osteoclasts were identified using tartrate-resistant acid phosphatase staining, and micro-computed tomography (CT) scanning and mechanical testing were used to study structure and mechanical properties. Micro-CT analysis showed that RES led to a significant reduction in trabecular BV/TV and trabecular number (Tb.N), concomitant with an increase in trabecular separation (Tb.Sp). Trabecular BV/TV and Tb.N were significantly greater in the CU group than in the RES in both short- and long-term experiments. Mechanical testing showed that RES led to weaker and less compliant bones; interestingly, bones of the CU group were also more fragile after 1 day of CU. Longer term of refeeding enabled correction of the bone parameters; however, LTCU did not achieve full recovery. These results suggest that RES in young rats attenuated growth and reduced trabecular bone parameters. While nutrition-induced CU growth led to an immediate increase in epiphyseal growth plate height and active bone modeling, it was also associated with a transient reduction in bone quality. This should be taken into consideration when treating children undergoing CU growth. © 2014 Society for Endocrinology.

  15. Factors affecting use of veterinarians by small-scale food animal operations.

    Science.gov (United States)

    Beam, Andrea L; Thilmany, Dawn D; Garber, Lindsey P; Van Metre, David C; Pritchard, Randy W; Kopral, Christine A; Olea-Popelka, Francisco J

    2013-11-01

    To identify factors associated with use of a veterinarian by small-scale food animal operations. Cross-sectional descriptive survey. 16,000 small-scale farm or ranch operations in all 50 states. Surveys were conducted via mail or telephone during 2011 for small-scale operations (gross annual agricultural sales between $10,000 and $499,999) in which an animal or animal product comprised the highest percentage of annual sales. 8,186 (51.2%) operations responded to the survey; 7,849 surveys met the inclusion criteria. For 6,511 (83.0%) operations, beef cattle were the primary animal species. An estimated 82.1% of operations (95% confidence interval [CI], 81.1% to 83.0%) had a veterinarian available ≤ 29 miles away; 1.4% (95% CI, 1.2% to 1.7%) did not have a veterinarian available within 100 miles of the operation. Operations for which the nearest veterinarian was ≥ 100 miles away or for which a veterinarian was not available were located in 40 US states. Overall, 61.7% of operations (95% CI, 60.6% to 62.9%) had used a veterinarian during the 12 months prior to the survey. Producers with college degrees were significantly more likely to use a veterinarian (675%) versus those who did not complete high school (52.9%). Results of this study indicated most small-scale operations had adequate access to veterinarians during 2011, but there seemed to be localized shortages of veterinarians in many states.

  16. Co-infection by alveolate parasites and frog virus 3-like ranavirus during an amphibian larval mortality event in Florida, USA

    National Research Council Canada - National Science Library

    Landsberg, Jan H; Kiryu, Yasunari; Tabuchi, Maki; Waltzek, Thomas B; Enge, Kevin M; Reintjes-Tolen, Sarah; Preston, Asa; Pessier, Allan P

    2013-01-01

    A multispecies amphibian larval mortality event, primarily affecting American bullfrogs Lithobates catesbeianus, was investigated during April 2011 at the Mike Roess Gold Head Branch State Park, Clay...

  17. Food connections: A qualitative exploratory study of weight- and eating-related distress in families affected by advanced cancer.

    Science.gov (United States)

    Hopkinson, J B

    2016-02-01

    Weight loss and eating problems are common in cancer and have a profound effect on quality of life. They are symptoms of cancer cachexia syndrome. This paper examines interdependency between advanced cancer patient and family carer experience of weight- and eating-related problems, leading to proposition of how weight- and eating-related distress might be alleviated in both patients and their family members. The study was of cross-sectional design. Interpretive phenomenology informed the analytic process. Patient participants had advanced cancer and concern about weight and/or eating. Semi-structured interviews were conducted with 31 patient-spouse/partner dyads (62 interviews), which focused on weight loss and eating problems in the patient and how these had been managed. This study found change in weight and eating habits in advanced cancer to disrupt food connections. Food connects us with others physically by fuelling the body and sustaining physical activity and life, emotionally by communicating feelings about self and others, and socially by providing a reason for sharing time with others. The study found three dyadic responses to disruption in food connections; dual acceptance, dual resistance and mismatched resistance. They are of interest, because they can help discriminate between those patient-family carer dyads who might benefit from psychosocial interventions and those who will cope without such help. The findings challenge clinicians and researchers to seek ways of aiding not only with concerns of the individual patients and carers, but also with interactions between distressed family members affected by symptoms of cancer cachexia syndrome. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

  18. Identification of the key bitter compounds in our daily diet is a prerequisite for the understanding of the hTAS2R gene polymorphisms affecting food choice.

    Science.gov (United States)

    Hofmann, Thomas

    2009-07-01

    In order to decode genetic variations affecting food choice and to determine whether to accept or to reject certain food products, it is a necessary prerequisite to deorphanize the hTAS2R/ligand pairs using the key bitter compounds in foods as stimuli rather than doing this either by using artificial molcules, to which the normal consumer had never been exposed, or by using food-born molecules which do not at all contribute to the overall bitterness. Therefore, the chemical structure of the most active bitter molecules in foods needs to be unequivocally determined in order to be sure that hTAS2R polymorphisms are related to the key molecules which really contribute to the overall bitterness perception of food products. As most studies focused primarily on quantitatively predominating compounds, rather than selecting the target compounds to be identified with regard to taste-activity, it seems that yet unknown components play a key role in evoking the bitter taste of food products. Driven by the need to discover the key players inducing the food taste, the research area "sensomics" made tremendous efforts in recent years to map the sensometabolome and to identify the most intense taste-active metabolites in fresh and processed foods. The present article summarizes recent studies on the identification of orphan key bitter stimuli in fresh, fermented, and thermally processed foods using carrots, cheese, and roasted coffee as examples.

  19. Developmental timing of a sensory-mediated larval surfacing behavior correlates with cessation of feeding and determination of final adult size

    OpenAIRE

    2010-01-01

    Controlled organismal growth to an appropriate adult size requires a regulated balance between nutrient resources, feeding behavior and growth rate. Defects can result in decreased survival and/or reproductive capability. Since Drosophila adults do not grow larger after eclosion, timing of feeding cessation during the third and final larval instar is critical to final size. We demonstrate that larval food exit is preceded by a period of increased larval surfacing behavior termed the Intermedi...

  20. Withdrawal of dietary phytoestrogens in adult male rats affects hypothalamic regulation of food intake, induces obesity and alters glucose metabolism.

    Science.gov (United States)

    Andreoli, María Florencia; Stoker, Cora; Rossetti, María Florencia; Alzamendi, Ana; Castrogiovanni, Daniel; Luque, Enrique H; Ramos, Jorge Guillermo

    2015-02-05

    The absence of phytoestrogens in the diet during pregnancy has been reported to result in obesity later in adulthood. We investigated whether phytoestrogen withdrawal in adult life could alter the hypothalamic signals that regulate food intake and affect body weight and glucose homeostasis. Male Wistar rats fed from conception to adulthood with a high phytoestrogen diet were submitted to phytoestrogen withdrawal by feeding a low phytoestrogen diet, or a high phytoestrogen-high fat diet. Withdrawal of dietary phytoestrogens increased body weight, adiposity and energy intake through an orexigenic hypothalamic response characterized by upregulation of AGRP and downregulation of POMC. This was associated with elevated leptin and T4, reduced TSH, testosterone and estradiol, and diminished hypothalamic ERα expression, concomitant with alterations in glucose tolerance. Removing dietary phytoestrogens caused manifestations of obesity and diabetes that were more pronounced than those induced by the high phytoestrogen-high fat diet intake. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. How avatar customizability affects children's arousal and subjective presence during junk food-sponsored online video games.

    Science.gov (United States)

    Bailey, Rachel; Wise, Kevin; Bolls, Paul

    2009-06-01

    The purpose of this study was to determine how children cognitively and emotionally process interactive marketing of snack food products in advergames. Children (N = 30) aged 10 to 12 were asked to play advergames with (a) avatars that were assigned to them, (b) avatars chosen from a pool, and (c) self-designed avatars. The children's skin conductance levels were collected during play. After gameplay, at each customization level, self-reported presence was collected. The results of this study indicate that customization of game avatars can affect both subjective feelings of presence and psychophysiological indicators of emotion during gameplay, which may make the gameplay experience more enjoyable. This may have implications for game sponsors and producers. Self-reported presence had no effect on psychophysiological indicators of emotion during gameplay. Implications of this finding and limitations of this study are discussed.

  2. Stretch-activated cation channel from larval bullfrog skin.

    Science.gov (United States)

    Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

    2010-05-01

    Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed a variable pattern of opening and closing with continuing suction. Current-voltage plots demonstrated linear or inward rectification and single channel conductances of 44-56 pS with NaCl or KCl Ringer's solution as the pipette solution, and a reversal potential (-V(p)) of 20-40 mV. The conductance was markedly reduced with N-methyl-D-glucamide (NMDG)-Cl Ringer's solution in the pipette. Neither amiloride nor ATP, which are known to stimulate an apical cation channel in Ussing chamber preparations of larval frog skin, produced channel activation nor did these compounds affect the response to suction. Stretch activation was not affected by varying the pipette concentrations of Ca(2+) between 0 mmol l(-1) and 4 mmol l(-1) or by varying pH between 6.8 and 8.0. However, conductance was reduced with 4 mmol l(-1) Ca(2+). Western blot analysis of membrane homogenates from larval bullfrog and larval toad skin identified proteins that were immunoreactive with mammalian TRPC1 and TRPC5 (TRPC, canonical transient receptor potential channel) antibodies while homogenates of skin from newly metamorphosed bullfrogs were positive for TRPC1 and TRPC3/6/7 antibodies. The electrophysiological response of larval bullfrog skin resembles that of a stretch-activated cation channel characterized in Xenopus oocytes and proposed to be TRPC1. These results indicate this channel persists in all life stages of anurans and that TRP isoforms may be important for sensory functions of their skin.

  3. Loss of rare fish species from tropical floodplain food webs affects community structure and ecosystem multifunctionality in a mesocosm experiment.

    Directory of Open Access Journals (Sweden)

    Richard M Pendleton

    Full Text Available Experiments with realistic scenarios of species loss from multitrophic ecosystems may improve insight into how biodiversity affects ecosystem functioning. Using 1000 L mesocoms, we examined effects of nonrandom species loss on community structure and ecosystem functioning of experimental food webs based on multitrophic tropical floodplain lagoon ecosystems. Realistic biodiversity scenarios were developed based on long-term field surveys, and experimental assemblages replicated sequential loss of rare species which occurred across all trophic levels of these complex food webs. Response variables represented multiple components of ecosystem functioning, including nutrient cycling, primary and secondary production, organic matter accumulation and whole ecosystem metabolism. Species richness significantly affected ecosystem function, even after statistically controlling for potentially confounding factors such as total biomass and direct trophic interactions. Overall, loss of rare species was generally associated with lower nutrient concentrations, phytoplankton and zooplankton densities, and whole ecosystem metabolism when compared with more diverse assemblages. This pattern was also observed for overall ecosystem multifunctionality, a combined metric representing the ability of an ecosystem to simultaneously maintain multiple functions. One key exception was attributed to time-dependent effects of intraguild predation, which initially increased values for most ecosystem response variables, but resulted in decreases over time likely due to reduced nutrient remineralization by surviving predators. At the same time, loss of species did not result in strong trophic cascades, possibly a result of compensation and complexity of these multitrophic ecosystems along with a dominance of bottom-up effects. Our results indicate that although rare species may comprise minor components of communities, their loss can have profound ecosystem consequences across

  4. Loss of rare fish species from tropical floodplain food webs affects community structure and ecosystem multifunctionality in a mesocosm experiment.

    Science.gov (United States)

    Pendleton, Richard M; Hoeinghaus, David J; Gomes, Luiz C; Agostinho, Angelo A

    2014-01-01

    Experiments with realistic scenarios of species loss from multitrophic ecosystems may improve insight into how biodiversity affects ecosystem functioning. Using 1000 L mesocoms, we examined effects of nonrandom species loss on community structure and ecosystem functioning of experimental food webs based on multitrophic tropical floodplain lagoon ecosystems. Realistic biodiversity scenarios were developed based on long-term field surveys, and experimental assemblages replicated sequential loss of rare species which occurred across all trophic levels of these complex food webs. Response variables represented multiple components of ecosystem functioning, including nutrient cycling, primary and secondary production, organic matter accumulation and whole ecosystem metabolism. Species richness significantly affected ecosystem function, even after statistically controlling for potentially confounding factors such as total biomass and direct trophic interactions. Overall, loss of rare species was generally associated with lower nutrient concentrations, phytoplankton and zooplankton densities, and whole ecosystem metabolism when compared with more diverse assemblages. This pattern was also observed for overall ecosystem multifunctionality, a combined metric representing the ability of an ecosystem to simultaneously maintain multiple functions. One key exception was attributed to time-dependent effects of intraguild predation, which initially increased values for most ecosystem response variables, but resulted in decreases over time likely due to reduced nutrient remineralization by surviving predators. At the same time, loss of species did not result in strong trophic cascades, possibly a result of compensation and complexity of these multitrophic ecosystems along with a dominance of bottom-up effects. Our results indicate that although rare species may comprise minor components of communities, their loss can have profound ecosystem consequences across multiple trophic

  5. Conjugated linoleic acid of dairy foods is affected by cows’ feeding system and processing of milk

    Directory of Open Access Journals (Sweden)

    Juan Pablo Avilez Ruiz

    2016-04-01

    Full Text Available ABSTRACT The distribution of conjugated linoleic acid (CLA in dairy products commercially available in Chile is poorly understood. This study aimed to assess the content of CLA in dairy cow products from Chile and the effect of processing fresh milk into dairy products. Samples of raw milk were categorized into two groups based on the animal feeding system utilized by the dairy farm: 1 grazing based systems (Los Lagos region; and 2 housing systems using total mixed ration (TMR diets (Los Angeles region. Simultaneously, commercial samples of condensed milk, powdered milk, butter and Gouda cheese were analyzed. Furthermore, samples of raw milk and processed products (powdered and sweetened condensed milk were also analyzed. Dairy farms based on grazing systems had higher levels of CLA in raw milk than TMR farms. In addition, average values of CLA were 1.72 g 100 g−1 of total fatty acids, in spring milk in the Los Lagos region, and 0.42 g 100 g−1 in summer milk, in the Los Angeles region. Similarly, the CLA content of dairy products was higher than that of raw milk. Milk processing affected the transferring of CLA from fresh milk into the final products. Sweetened condensed milk presented lower CLA values than raw and powdered milk. In conclusion, this study indicates the importance of the production systems to the CLA content as well as the effects of milk processing into dairy products. To sum up, more research is needed to elucidate the exact effect of the processing conditions of dairy products on the CLA content.

  6. The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees

    Science.gov (United States)

    In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diet are often complex and may interact with one another, necessitating the use of a geometric framework for und...

  7. Predicting intentions to purchase organic food: the role of affective and moral attitudes in the Theory of Planned Behaviour.

    Science.gov (United States)

    Arvola, A; Vassallo, M; Dean, M; Lampila, P; Saba, A; Lähteenmäki, L; Shepherd, R

    2008-01-01

    This study examined the usefulness of integrating measures of affective and moral attitudes into the Theory of Planned Behaviour (TPB)-model in predicting purchase intentions of organic foods. Moral attitude was operationalised as positive self-rewarding feelings of doing the right thing. Questionnaire data were gathered in three countries: Italy (N=202), Finland (N=270) and UK (N=200) in March 2004. Questions focussed on intentions to purchase organic apples and organic ready-to-cook pizza instead of their conventional alternatives. Data were analysed using Structural Equation Modelling by simultaneous multi-group analysis of the three countries. Along with attitudes, moral attitude and subjective norms explained considerable shares of variances in intentions. The relative influences of these variables varied between the countries, such that in the UK and Italy moral attitude rather than subjective norms had stronger explanatory power. In Finland it was other way around. Inclusion of moral attitude improved the model fit and predictive ability of the model, although only marginally in Finland. Thus the results partially support the usefulness of incorporating moral measures as well as affective items for attitude into the framework of TPB.

  8. Phenotypic plasticity in sperm traits in scorpionflies (Mecoptera : Panorpidae): Consequences of larval history and seasonality on sperm length and sperm transfer

    NARCIS (Netherlands)

    Vermeulen, Andreas; Engels, Sierk; Engqvist, Leif; Sauer, Klaus Peter

    2009-01-01

    We examined effects of seasonality, larval food availability and larval rearing density on sperm length, sperm transfer rates and body size in the bivoltine scorpionfly Panorpa vulgaris. Males of the first annual generation were larger and had larger sperm. Comparing individuals of two summer genera

  9. Sodium benzoate, a food preservative, affects the functional and activation status of splenocytes at non cytotoxic dose.

    Science.gov (United States)

    Yadav, Ashish; Kumar, Arvind; Das, Mukul; Tripathi, Anurag

    2016-02-01

    Sodium benzoate (SB) is a widely used food preservative due to its bacteriostatic and fungistatic properties. The acceptable daily intake of SB is 5 mg/kg-bw, however, it has been found to be used in the food commodities at relatively high levels (2119 mg/kg). Earlier studies on SB have shown its immunosuppressive properties, but comprehensive immunotoxicity data is lacking. Our studies have shown that SB was non cytotoxic in splenocytes up to 1000 μg/ml for 72 h, however at 2500 μg/ml it was found to be cytotoxic. Thus, 1000 μg/ml dose of SB was chosen for the subsequent experiments. SB significantly suppresses the proliferation of Con A and LPS stimulated splenocytes at 72 h, while allogenic response of T cells was significantly decreased after 96 h. SB did not affect the relative expression of CD3e or CD4 molecules following 72 h exposure, however, it downregulated the relative expression of CD8 co-receptor. Further, exposure of splenocytes to SB for 72 h led to reduced expression of CD28 and CD95, which play a vital role in T cell activation. SB also suppresses the relative expression of CD19, CD40 and CD95 receptors on B cells after 72 h. In addition to the functional responses, SB lowered the expression of IL4, IL6, IFNγ and IL17 cytokines in Con A stimulated splenocytes; and IL6, IFNγ and TNFα in LPS stimulated splenocytes following 48 h of exposure. Taken together, the present study is suggestive of the immunomodulatory potential of SB.

  10. Condition of larval red snapper (Lutjanus campechanus) relative to environmental variability and the Deepwater Horizon oil spill

    Science.gov (United States)

    Hernandez, F. J., Jr.; Filbrun, J. E.; Fang, J.; Ransom, J. T.

    2016-09-01

    The Deepwater Horizon oil spill (DWHOS) spatially and temporally overlapped with the spawning of many fish species, including Red Snapper, one of the most economically important reef fish in the Gulf of Mexico. To investigate potential impacts of the DWHOS on larval Red Snapper, data from a long-term ichthyoplankton survey off the coast of Alabama were used to examine: (1) larval abundances among pre-impact (2007-2009), impact (2010), and post-impact (2011, 2013) periods; (2) proxies for larval condition (size-adjusted morphometric relationships and dry weight) among the same periods; and (3) the effects of background environmental variation on larval condition. We found that larval Red Snapper were in poorer body condition during 2010, 2011, and 2013 as compared to the 2007-2009 period, a trend that was strongly (and negatively) related to variation in Mobile Bay freshwater discharge. However, larvae collected during and after 2010 were in relatively poor condition even after accounting for variation in freshwater discharge and other environmental variables. By contrast, no differences in larval abundance were detected during these survey years. Taken together, larval supply did not change relative to the timing of the DWHOS, but larval condition was negatively impacted. Even small changes in condition can affect larval survival, so these trends may have consequences for recruitment of larvae to juvenile and adult life stages.

  11. Role of circulation scales and water mass distributions on larval fish habitats in the Eastern Tropical Pacific off Mexico

    Science.gov (United States)

    León-Chávez, Cristina A.; Beier, Emilio; Sánchez-Velasco, Laura; Barton, Eric Desmond; Godínez, Victor M.

    2015-06-01

    On the basis of five oceanographic cruises carried out in the Eastern Tropical Pacific off Mexico, relationships between the larval fish habitats (areas inhabited by larval fish assemblages) and the environmental circulation scales (mesoscale, seasonal, and interannual) were examined. Analysis of in situ data over a grid of hydrographic stations and oblique zooplankton hauls with bongo net (505 µm) was combined with orthogonal robust functions decomposition applied to altimetry anomalies obtained from satellite. During both cool (March and June) and warm (August and November) periods, Bray-Curtis dissimilarity Index defined three recurrent larval fish habitats which varied in species composition and extent as a function of the environmental scales. The variability of the Tropical larval fish habitat (characterized by high species richness, and dominated by Vinciguerria lucetia, Diogenichthys laternatus, and Diaphus pacificus) was associated with the seasonal changes. The Transitional-California Current larval fish habitat (dominated by V. lucetia and D. laternatus, with lower mean abundance and lower species richness than in the Tropical habitat) and Coastal-and-Upwelling larval fish habitat (dominated by Bregmaceros bathymaster) was associated mainly with mesoscale activity induced by eddies and with coastal upwelling. During February 2010, the Tropical larval fish habitat predominated offshore and the Transitional-California Current larval fish habitat was not present, which we attribute to the effect of El Niño conditions. Thus, the mesoscale, seasonal, and interannual environmental scales affect the composition and extension of larval fish habitats.

  12. Susceptibility to Overeating Affects the Impact of Savory of Sweet Drinks on Satiation, Reward, and Food Intake in Nonobese Women

    NARCIS (Netherlands)

    Finlayson, G.; Bordes, I.; Griffioen-Roose, S.; Graaf, de C.; Blundell, J.E.

    2012-01-01

    Taste is involved in food preference and choice, and it is thought that it can modulate appetite and food intake. The present study investigated the effect of savory or sweet taste on satiation, reward, and food intake and according to individual differences in eating behavior traits underlying

  13. Susceptibility to Overeating Affects the Impact of Savory of Sweet Drinks on Satiation, Reward, and Food Intake in Nonobese Women

    NARCIS (Netherlands)

    Finlayson, G.; Bordes, I.; Griffioen-Roose, S.; Graaf, de C.; Blundell, J.E.

    2012-01-01

    Taste is involved in food preference and choice, and it is thought that it can modulate appetite and food intake. The present study investigated the effect of savory or sweet taste on satiation, reward, and food intake and according to individual differences in eating behavior traits underlying susc

  14. [Canine peritoneal larval cestodosis caused by Mesocestoides spp. larval stages].

    Science.gov (United States)

    Häußler, T C; Peppler, C; Schmitz, S; Bauer, C; Hirzmann, J; Kramer, M

    2016-01-01

    In a female dog with unspecific clinical symptoms, sonography detected a hyperechoic mass in the middle abdomen and blood analysis a middle grade systemic inflammatory reaction. Laparotomy revealed a peritoneal larval cestodosis (PLC). The diagnosis of an infection with tetrathyridia of Mesocestoides spp. was confirmed by parasitological examination and molecularbiological analysis. Reduction of the intra-abdominal parasitic load as well as a high dose administration of fenbendazole over 3 months led to a successful treatment which could be documented sonographically and by decreased concentrations of C-reactive protein (CRP). Seven months after discontinuation of fenbendazole administration, PLC recurred, pre-empted by an elevation of serum CRP values. According to the literature a life-long fenbendazole treatment was initiated. In cases of unclear chronic granulomatous inflammations in the abdominal cavity in dogs, PLC should be considered. CRP concentration and sonographic examinations are suitable to control for treatment success and a possibly occurring relapse.

  15. Food allergy

    Directory of Open Access Journals (Sweden)

    Youngshin Han

    2012-05-01

    Full Text Available Food allergy is an important public health problem affecting 5% of infants and children in Korea. Food allergy is defined as an immune response triggered by food proteins. Food allergy is highly associated with atopic dermatitis and is one of the most common triggers of potentially fatal anaphylaxis in the community. Sensitization to food allergens can occur in the gastrointestinal tract (class 1 food allergy or as a consequence of cross reactivity to structurally homologous inhalant allergens (class 2 food allergy. Allergenicity of food is largely determined by structural aspects, including cross-reactivity and reduced or enhanced allergenicity with cooking that convey allergenic characteristics to food. Management of food allergy currently focuses on dietary avoidance of the offending foods, prompt recognition and treatment of allergic reactions, and nutritional support. This review includes definitions and examines the prevalence and management of food allergies and the characteristics of food allergens.

  16. Toxicokinetics of the food-toxin IQ in human placental perfusion is not affected by ABCG2 or xenobiotic metabolism

    DEFF Research Database (Denmark)

    Immonen, E; Kummu, M; Petsalo, A

    2010-01-01

    Metabolizing enzymes and transporters affect toxicokinetics of foreign compounds (e.g. drugs and carcinogens) in human placenta. The heterocyclic amine, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) is a food-borne carcinogen being metabolically activated by cytochrome P450 (CYP) enzymes, especially...... by CYP1A1/2. IQ is also a substrate for ABCG2 transporter. Placental transfer of (14)C-IQ was evaluated in 4-6 h ex vivo human placental perfusions in Finland and Denmark. In Finland placentas were perfused with (14)C-IQ alone (0.5 muM, n = 6) or in combination with GF120918 (inhibitor of ABCG2, 1 muM, n...... = 6) or Ko143 (specific inhibitor of ABCG2, 2 muM, n = 4) to study the role of ABCG2 inhibition in transfer while in Denmark perfusions were performed with (14)C-IQ alone. Critical parameters (leak from fetal to maternal circulation, pH values, blood gases, glucose consumption, the production of h...

  17. Preimaginal exposure to azadirachtin affects food selection and digestive enzymes in adults of Drosophila melanogaster (Diptera: Drosophilidae).

    Science.gov (United States)

    Kilani-Morakchi, Samira; Bezzar-Bendjazia, Radia; Ferdenache, Maroua; Aribi, Nadia

    2017-08-01

    Among the plant derived product, azadirachtin, a neem-based insecticide, is exceptional in having a broad range of bioactivity including toxicity, growth, development and reproduction effects, repellency and antifeedancy. If considerable progress on the physiological and biological activities and agricultural application of azadirachtin has been achieved, its exact mechanism of action remains uncertain. In this study, we aimed at assessing the lethal and sublethal behavioral and physiological effects of azadirachtin on Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae) as biological model. Azadirachtin was applied topically at two doses LD25 (0.28μg) and LD50 (0.67μg) on early third instar larvae. Results showed that flies preferentially ingested control medium rather than azadirachtin-treated medium. Pre-imaginal exposure (L3) to azadirachtin increased aversion to this substance suggesting a memorability of the learned avoidance. In addition, all tested flies revealed a clear preference for solvent odour rather than azadirachtin odour. Moreover, azadirachtin treatment decreased significantly the amount of food intake in the adults of both sexes. Finally, azadirachtin was found to affect digestive enzyme activities in the midgut of flies. Indeed, an inhibition of α-amylase, chitinase, and protease activities and an increase of lipasic activity were noted. These results may reflect interference of azadirachtin with regulation of feeding and metabolism, and provide some evidence of a long term antifeedancy and delayed effects through developmental stage which may reinforce the insecticidal activity of this bioinsecticide. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Intrauterine growth restriction increases the preference for palatable foods and affects sensitivity to food rewards in male and female adult rats.

    Science.gov (United States)

    Dalle Molle, Roberta; Laureano, Daniela Pereira; Alves, Márcio Bonesso; Reis, Tatiane Madeira; Desai, Mina; Ross, Michael G; Silveira, Patrícia Pelufo

    2015-08-27

    Clinical evidence suggests that intrauterine growth restriction (IUGR) can cause persistent changes in the preference for palatable foods. In this study, we compared food preferences, the response to food rewards, and the role of the mesolimbic dopaminergic system in feeding behavior, between IUGR and control rats. Time-mated pregnant Sprague-Dawley rats were randomly allocated to a control group (standard chow ad libitum) or a 50% food restriction (FR) group, which received 50% of the control dams׳ habitual intake. These diets were provided from gestation day 10 to the 21st day of lactation. Within 24h of birth, pups were cross-fostered and divided into four groups: Adlib/Adlib, FR/Adlib, FR/FR, Adlib/FR. Standard chow consumption was compared between all groups. Food preferences, conditioned place preference to a palatable diet, and the levels of tyrosine hydroxylase (TH) phosphorylation and D2 receptors in the nucleus accumbens were analyzed and compared between the two groups of interest: Adlib/Adlib (control) and FR/Adlib (exposed to growth restriction during the fetal period only). IUGR adult rats had a stronger preference for palatable foods, but showed less conditioned place preference to a palatable diet than controls. D2 receptors levels were lower in IUGR rats. At baseline, TH and pTH levels were higher in FR/Adlib than control males. Measurements taken after exposure to sweet foods revealed higher levels of TH and pTH in FR/Adlib than control females. These data showed that IUGR rats exhibited a preference for palatable foods, potentially due to alterations in their mesolimbic reward pathway. Additionally, the changes observed in the mesolimbic dopaminergic system of IUGR rats proved to be sex-specific. This article is part of a Special Issue entitled 1618. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Effect of Larval Competition on Extrinsic Incubation Period and Vectorial Capacity of Aedes albopictus for Dengue Virus.

    Science.gov (United States)

    Bara, Jeffrey; Rapti, Zoi; Cáceres, Carla E; Muturi, Ephantus J

    2015-01-01

    Despite the growing awareness that larval competition can influence adult mosquito life history traits including susceptibility to pathogens, the net effect of larval competition on human risk of exposure to mosquito-borne pathogens remains poorly understood. We examined how intraspecific larval competition affects dengue-2 virus (DENV-2) extrinsic incubation period and vectorial capacity of its natural vector Aedes albopictus. Adult Ae. albopictus from low and high-larval density conditions were orally challenged with DENV-2 and then assayed for virus infection and dissemination rates following a 6, 9, or 12-day incubation period using real-time quantitative reverse transcription PCR. We then modeled the effect of larval competition on vectorial capacity using parameter estimates obtained from peer-reviewed field and laboratory studies. Larval competition resulted in significantly longer development times, lower emergence rates, and smaller adults, but did not significantly affect the extrinsic incubation period of DENV-2 in Ae. albopictus. Our vectorial capacity models suggest that the effect of larval competition on adult mosquito longevity likely has a greater influence on vectorial capacity relative to any competition-induced changes in vector competence. Furthermore, we found that large increases in the viral dissemination rate may be necessary to compensate for small competition-induced reductions in daily survivorship. Our results indicate that mosquito populations that experience stress from larval competition are likely to have a reduced vectorial capacity, even when susceptibility to pathogens is enhanced.

  20. A larval hunger signal in the bumblebee Bombus terrestris

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Duchateau, Marie-Jose

    2006-01-01

    broods sprayed with the extracts of the starved larvae were fed significantly more than larval broods sprayed with the extracts of normally fed larvae or with the solvent (n-pentane) only. We therefore conclude that B. terrestris larvae signal their need for food via their cuticular chemicals...

  1. The influence of larval competition on Brazilian Wolbachia-infected Aedes aegypti mosquitoes.

    Science.gov (United States)

    Dutra, Heverton Leandro Carneiro; Lopes da Silva, Vanessa; da Rocha Fernandes, Mariana; Logullo, Carlos; Maciel-de-Freitas, Rafael; Moreira, Luciano Andrade

    2016-05-16

    With field releases starting in Brazil, particular interest must be given to understanding how the endosymbiotic bacterium Wolbachia pipientis affects Aedes aegypti mosquitoes with a Brazilian genetic background. Currently, there is limited information on how the bacterium affects phenotypic traits such as larval development rate, metabolic reserves and morphometric parameters in Ae. aegypti. Here, we analyze for the first time, the effect of Wolbachia on these key phenotypes and consider how this might impact the potential of the bacterium as a disease control agent in Brazil. We examined the influence of the wMel strain of Wolbachia in laboratory Ae. aegypti with a Brazilian genetic background, reared under different larval densities. Pupae formation was counted daily to assess differences in development rates. Levels of metabolic reserves and morphometric parameters were assessed in adults resulting from each larval condition. wMel infection led to more rapid larval development at higher densities for both males and females, with no effect under less crowded conditions in females. Infection also led to reduced body size at both high and low density, but not at intermediate density, although the scale of this difference was maintained regardless of larval density, in comparison to uninfected individuals. Wing shape also varied significantly between infected and uninfected mosquitoes due to larval density. Glycogen levels in uninfected mosquitoes decreased under higher larval density, but were consistently high with Wolbachia infection, regardless of larval density. We demonstrate that the wMel Wolbachia strain can positively influence some important host fitness traits, and that this interaction is directly linked to the conditions in which the host is reared. Combined with previously published data, these results suggest that this Wolbachia strain could be successfully used as part of the Eliminate Dengue Program in Brazil.

  2. Dopamine D4 receptor (D4R) deletion in mice does not affect operant responding for food or cocaine

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, P.K.

    2009-10-22

    In this study we examined the genetic contribution of the D4R in food and cocaine self-administration using D4R mice. Mice were examined for operant responding to food pellets or intravenous cocaine. Compared to wild-type mice (D4R{sup +/+}), both heterozygous (D4R{sup +/-}) and knockout (D4R{sup -/-}) mice showed no difference in responding for food or cocaine. Our findings suggest that the D4R is not directly involved in mediating operant response behaviors for food or cocaine.

  3. [Assessing various aspects of the motivation to eat that can affect food intake and body weight control].

    Science.gov (United States)

    Bellisle, F

    2009-04-01

    Over the last 30 years, several questionnaires have been developed and validated in order to assess many aspects of the motivation to eat that might be susceptible to impair adequate food intake and body weight control. A few of such questionnaires are described here, in particular, the "Three Factor Eating Questionnaire" also called the "Eating Inventory", and the "Dutch Eating Behavior Questionnaire". Critical aspects of the motivation to eat assessed by these tools are presented, such as dietary restraint, disinhibition, hunger, vulnerability to eat in response to external cues or emotional states, etc. These questionnaires were developed for use in the general population with the aim to identify critical aspects of the motivation to eat that might predispose to weight gain. They have been widely used in many countries and have allowed an improved understanding of the individual characteristics that predispose to body weight gain or resistance to weight loss. Originally, poor body weight control was attributed to a high level of dietary "restraint", or in other words, the tendency to deliberately restrict one's food intake for body weight control purposes. Such dietary restraint was suspected to lead to a number of physical and psychological difficulties, among which poor self-esteem and a paradoxical tendency to gain weight, resulting from the incapacity to maintain strict restraint over time. More recent studies have established that a motivational trait called "Disinhibition" is a strong predictor of body weight gain over time and of poor outcome of dieting. "Disinhibition" corresponds to a tendency to lose control over one's eating behavior and ingest excessively large quantities of food substances, in response to a variety of cues and circumstances. In addition to its untoward effect on weight, disinhibition also predicts various risk factors and pathologies, such as hypertension and diabetes. Other potentially critical dimensions for adequate body weight

  4. Protein source and quality in therapeutic foods affect the immune response and outcome in severe acute malnutrition

    Science.gov (United States)

    Protein is a vital component of therapeutic foods designed to treat severe acute malnutrition (SAM) in children; however there are still unknowns about the quality and quantity of the proteins to use in these foods. This review examines two recent studies investigating several different qualities an...

  5. Tobacco and alcohol sponsorship of sporting events provide insights about how food and beverage sponsorship may affect children's health.

    Science.gov (United States)

    Kelly, Bridget; Baur, Louise A; Bauman, Adrian E; King, Lesley

    2011-08-01

    Determining children's exposure to food and beverage company sponsorship, and the effect of this exposure, is important in establishing the extent to which there may be health and societal consequences. This paper aimed to provide preliminary evidence on the scope and potential effects on children of unhealthy food and beverage sponsorship. A review of published literature and media and marketing reports was conducted to determine the types of food and beverage sponsorship campaigns that children are exposed to, and the effect of corporate sponsorship (including tobacco and alcohol) on children and adolescents. A large range of food and beverage sponsorship activities, in Australia and internationally, were identified for both school and sport settings. In particular, food and beverage companies have attempted to develop a marketing presence at all levels of professional and community sport. No information was identified measuring the effect of food and beverage company sponsorship on children and adolescents. However, empirical evidence from consumer studies relating to tobacco and alcohol sponsorship has repeatedly demonstrated that sponsorship has an impact on children's product recall and product-related attitudes and behavioural intentions. While there is no available research on the direct effect of food and beverage sponsorship, the demonstrated effects of tobacco and alcohol sponsorship on children's product awareness, preferences and consumption are likely to be applicable to food companies.

  6. The Challenge of Compliance: Food Security in Rural Households Affected by Welfare Reform. Food Assistance Needs of the South's Vulnerable Population.

    Science.gov (United States)

    Monroe, Pamela A.; O'Neil, Carol; Tiller, Vicky V.; Smith, Jennifer

    A study examined welfare reform and food security issues. Interviews were conducted with 32 rural Louisiana women in 1997-98 when they were receiving welfare payments, in 1998-99 when they were in transition, and in 2000-01 when none received Temporary Assistance for Needy Families (TANF). Most women were African-American; about half had not…

  7. Does the local food environment around schools affect diet? Longitudinal associations in adolescents attending secondary schools in East London.

    Science.gov (United States)

    Smith, Dianna; Cummins, Steven; Clark, Charlotte; Stansfeld, Stephen

    2013-01-24

    The local retail food environment around schools may act as a potential risk factor for adolescent diet. However, international research utilising cross-sectional designs to investigate associations between retail food outlet proximity to schools and diet provides equivocal support for an effect. In this study we employ longitudinal perspectives in order to answer the following two questions. First, how has the local retail food environment around secondary schools changed over time and second, is this change associated with change in diet of students at these schools? The locations of retail food outlets and schools in 2001 and 2005 were geo-coded in three London boroughs. Network analysis in a Geographic Information System (GIS) ascertained the number, minimum and median distances to food outlets within 400 m and 800 m of the school location. Outcome measures were 'healthy' and 'unhealthy' diet scores derived from adolescent self-reported data in the Research with East London Adolescents: Community Health Survey (RELACHS). Adjusted associations between distance from school to food retail outlets, counts of outlets near schools and diet scores were assessed using longitudinal (2001-2005 n=757) approaches. Between 2001 and 2005 the number of takeaways and grocers/convenience stores within 400 m of schools increased, with many more grocers reported within 800 m of schools in 2005 (pproximity to takeaways and unhealthy diet scores also resulted in small parameter estimates. The results provide some evidence that the local food environment around secondary schools may influence adolescent diet, though effects were small. Further research on adolescents' food purchasing habits with larger samples in varied geographic regions is required to identify robust relationships between proximity and diet, as small numbers, because of confounding, may dilute effect food environment effects. Data on individual foods purchased in all shop formats may clarify the frequent

  8. Does the local food environment around schools affect diet? Longitudinal associations in adolescents attending secondary schools in East London

    Directory of Open Access Journals (Sweden)

    Smith Dianna

    2013-01-01

    Full Text Available Abstract Background The local retail food environment around schools may act as a potential risk factor for adolescent diet. However, international research utilising cross-sectional designs to investigate associations between retail food outlet proximity to schools and diet provides equivocal support for an effect. In this study we employ longitudinal perspectives in order to answer the following two questions. First, how has the local retail food environment around secondary schools changed over time and second, is this change associated with change in diet of students at these schools? Methods The locations of retail food outlets and schools in 2001 and 2005 were geo-coded in three London boroughs. Network analysis in a Geographic Information System (GIS ascertained the number, minimum and median distances to food outlets within 400 m and 800 m of the school location. Outcome measures were ‘healthy’ and ‘unhealthy’ diet scores derived from adolescent self-reported data in the Research with East London Adolescents: Community Health Survey (RELACHS. Adjusted associations between distance from school to food retail outlets, counts of outlets near schools and diet scores were assessed using longitudinal (2001–2005 n=757 approaches. Results Between 2001 and 2005 the number of takeaways and grocers/convenience stores within 400 m of schools increased, with many more grocers reported within 800 m of schools in 2005 (p Conclusions The results provide some evidence that the local food environment around secondary schools may influence adolescent diet, though effects were small. Further research on adolescents’ food purchasing habits with larger samples in varied geographic regions is required to identify robust relationships between proximity and diet, as small numbers, because of confounding, may dilute effect food environment effects. Data on individual foods purchased in all shop formats may clarify the frequent, overly simple

  9. Process-based models of feeding and prey selection in larval fish

    DEFF Research Database (Denmark)

    Fiksen, O.; MacKenzie, Brian

    2002-01-01

    rates and prey selection in larval cod. Observed pursuit times of larvae are long and approach velocity slow enough to avoid an escape response from prey, but too short to avoid loss of prey at high turbulence levels. The pause-travel search mode is predicted to promote ingestion of larger prey than...... jig dry wt l(-1). The spatio-temporal fluctuation of turbulence (tidal cycle) and light (sun height) over the bank generates complex structure in the patterns of food intake of larval fish, with different patterns emerging for small and large larvae....

  10. The effect of larval nutritional deprivation on the life history and DDT resistance phenotype in laboratory strains of the malaria vector Anopheles arabiensis

    Directory of Open Access Journals (Sweden)

    Oliver Shüné V

    2013-02-01

    Full Text Available Abstract Background Anopheles arabiensis is a major malaria vector in Africa. It thrives in agricultural areas and has been associated with increased malaria incidence in areas under rice and maize cultivation. This effect may be due to increased adult size and abundance as a consequence of optimal larval nutrition. The aim of this study was to examine the effect of larval nutrition on the life history and expression of insecticide resistance in adults of laboratory reared An. arabiensis. Methods Larvae drawn from an insecticide susceptible An. arabiensis strain (SENN as well as a DDT-resistant strain (SENN-DDT were subjected to three fasting regimes: 1 mg of food per larva offered once per day, once every second day and once every third day. Control cohorts included larvae offered 1 mg food thrice per day. The rate of larval development was compared between matched cohorts from each strain as well as between fasted larvae and their respective controls. The expression of DDT resistance/tolerance in adults was compared between the starved cohorts and their controls by strain. Factors potentially affecting variation in DDT resistance/tolerance were examined including: adult body size (wing length, knock-down resistance (kdr status and levels of detoxification enzyme activity. Results and conclusion Anopheles arabiensis larval development is prolonged by nutrient deprivation and adults that eclose from starved larvae are smaller and less tolerant to DDT intoxication. This effect on DDT tolerance in adults is also associated with reduced detoxification enzyme activity. Conversely, well fed larvae develop comparatively quickly into large, more DDT tolerant (SENN or resistant (SENN-DDT adults. This is important in those instances where cereal farming is associated with increased An. arabiensis transmitted malaria incidence, because large adult females with high teneral reserves and decreased susceptibility to insecticide intoxication may also

  11. Arrested larval development in cattle nematodes.

    Science.gov (United States)

    Armour, J; Duncan, M

    1987-06-01

    Most economically important cattle nematodes are able to arrest their larval development within the host - entering a period of dormancy or hypobiosis. Arrested larvae have a low death rate, and large numbers can accumulate in infected cattle during the grazing season. Because of this, outbreaks of disease caused by such nematodes can occur at times when recent infection with the parasites could not have occurred, for example during winter in temperature northern climates when cattle are normally housed. The capacity to arrest is a heritable trait. It is seen as an adaptation by the parasite to avoid further development to its free-living stages during times when the climate is unsuitable for free-living survival. But levels of arrestment can vary markedly in different regions, in different cattle, and under different management regimes. Climatic factors, previous conditioning, host immune status, and farm management all seem to affect arrestment levels. In this article, James Armour and Mary Duncan review the biological basis of the phenomenon, and discuss the apparently conflicting views on how it is controlled.

  12. Sensory-specific appetite is affected by actively smelled food odors and remains stable over time in normal-weight women.

    Science.gov (United States)

    Ramaekers, Mariëlle G; Boesveldt, Sanne; Gort, Gerrit; Lakemond, Catriona M M; van Boekel, Martinus A J S; Luning, Pieternel A

    2014-08-01

    Understanding overconsumption starts with knowledge of how separate factors influence our eating behavior. Food cues such as food odors are known for their effect on general appetite and sensory-specific appetite (SSA). Active sniffing rather than passive exposure may induce satiation over time. The objective of this study was to investigate how actively sniffing banana odors affects general appetite, SSA, and subsequent food intake. In a crossover study, 61 women actively smelled cups containing natural banana, artificial banana odor, or water (no odor) for 10 min. Treatment order was randomly assigned as much as possible. General appetite and SSA were monitored by using 100-mm visual analog scales during the 10 min of active sniffing, followed by ad libitum intake of banana milkshake. Results showed that SSA was consistently high (+12 mm) during actively sniffing natural or artificial banana odors, with no decrease in SSA over time. Sniffing both banana odors increased the appetite for banana (+11 mm) and other sweet products (+4 mm), whereas the appetite for savory products decreased by 7 mm (all P appetite scores (P = 0.06). In conclusion, SSA scores during active sniffing were identical to the SSA found in a similar study that used passive smelling, suggesting that SSA is independent of the manner of sniffing and exposure time. Moreover, sweet/savory categorization may suggest that food odors communicate information about the nutrient composition of their associated foods. These data clearly show the appetizing effects of food odors.

  13. Feeding competition between larval lake whitefish and lake herring

    Science.gov (United States)

    Savino, Jacqueline F.; Hudson, Patrick L.

    1995-01-01

    The potential for competition for food between larval lake whitefish (Coregonus clupeaformis) and lake herring (C. artedi) 1- to 8-wk of age was explored in a series of 1-h laboratory feeding studies. Feeding started at 2-wk post-hatch. Learning and fish size appear to be more important than prey density at the onset of feeding. Species differed in their feeding behavior and consumption noticeably by 5-wk and substantially by 8-wk. Lake whitefish generally were more aggressive foragers than lake herring, attacking and capturing more prey. At high plankton density at 8-wk, lake herring feeding was depressed in mixed-fish treatments. This difference in competitive food consumption between the two coregonids occurs at a critical life stage, and when combined with other biotic and abiotic factors, may have a significant impact on recruitment.

  14. Behavioral ecology of larval dragonflies and damselflies.

    Science.gov (United States)

    Johnson, D M

    1991-01-01

    During the past decade, larval dragonflies and damselflies (Insecta: Odonata) have been the subjects for very productive ecological research. Descriptive field work, enclosure experiments and laboratory behavior studies have identified fish predation, intraguild predation (especially mutual predation among odonates, including cannibalism) and interference competition as particularly strong interactions influencing larval odonate assemblages. Behavioral differences among species suggest evolutionary adaptations for coexistence with different predators, and for winning intraspecific aggressive encounters.

  15. Detecting larval export from marine reserves.

    Science.gov (United States)

    Pelc, R A; Warner, R R; Gaines, S D; Paris, C B

    2010-10-26

    Marine reserve theory suggests that where large, productive populations are protected within no-take marine reserves, fished areas outside reserves will benefit through the spillover of larvae produced in the reserves. However, empirical evidence for larval export has been sparse. Here we use a simple idealized coastline model to estimate the expected magnitude and spatial scale of larval export from no-take marine reserves across a range of reserve sizes and larval dispersal scales. Results suggest that, given the magnitude of increased production typically found in marine reserves, benefits from larval export are nearly always large enough to offset increased mortality outside marine reserves due to displaced fishing effort. However, the proportional increase in recruitment at sites outside reserves is typically small, particularly for species with long-distance (on the order of hundreds of kilometers) larval dispersal distances, making it very difficult to detect in field studies. Enhanced recruitment due to export may be detected by sampling several sites at an appropriate range of distances from reserves or at sites downcurrent of reserves in systems with directional dispersal. A review of existing empirical evidence confirms the model's suggestion that detecting export may be difficult without an exceptionally large differential in production, short-distance larval dispersal relative to reserve size, directional dispersal, or a sampling scheme that encompasses a broad range of distances from the reserves.

  16. Larval development of Spodoptera eridania (Cramer fed on leaves of Bt maize expressing Cry1F and Cry1F + Cry1A.105 + Cry2Ab2 proteins and its non-Bt isoline

    Directory of Open Access Journals (Sweden)

    Orcial Ceolin Bortolotto

    2015-03-01

    Full Text Available This study aimed to evaluate, in controlled laboratory conditions (temperature of 25±2 °C, relative humidity of 60±10%, and 14/10 h L/D photoperiod, the larval development of Spodoptera eridania (Cramer, 1784 (Lepidoptera, Noctuidae fed with leaves of Bt maize expressing Cry1F and Cry1F + Cry1A.105 + Cry2Ab2 insecticide proteins and its non-Bt isoline. Maize leaves triggered 100% of mortality on S. eridania larvae independently of being Bt or non-Bt plants. However, it was observed that in overall Bt maize (expressing a single or pyramided protein slightly affects the larval development of S. eridania, even under reduced leaf consumption. Therefore, these results showed that Cry1F and Cry1F + Cry1A.105 + Cry2Ab2 can affect the larval development of S. eridania, although it is not a target pest of this plant; however, more research is needed to better understand this evidence. Finally, this study confirms that non-Bt maize leaves are unsuitable food source to S. eridania larvae, suggesting that they are not a potential pest in maize fields.

  17. How Growing Complexity of Consumer Choices and Drivers of Consumption Behaviour Affect Demand for Animal Source Foods.

    Science.gov (United States)

    Perry, B D; Grace, D C

    2015-12-01

    Many societies are spoiled for choice when they purchase meat and other livestock products, and around the globe food choice has grown dramatically in the last two decades. What is more, besides the cost and obvious health concerns influencing commodity section, an increasing proportion of choices is made to contribute to the achievement of certain ideals, such as natural resource management, climate change mitigation, animal welfare concerns and personal lifestyle. At the same time, human health considerations are becoming more important for consumption choices as richer societies, and increasingly the urban poor in low- and middle-income countries, face an unprecedented epidemic of over-consumption and associated diet-related non-communicable diseases. Animal source foods are considered significant contributors to this trend. This paper reviews this complicated arena, and explores the range of considerations that influence consumers' preferences for meat and other animal source foods. This paper also argues that deeper drivers of consumption behaviour of many foods may act in opposition to the articulated preferences for choices around animal source food consumption. We review how the returns to different causes are being valued, how emerging metrics are helping to manage and influence consumption behaviours, and draw conclusions regarding options which influence food choice.

  18. Food quality and the risk of light exposure affect patch-choice decisions in the slime mold Physarum polycephalum.

    Science.gov (United States)

    Latty, Tanya; Beekman, Madeleine

    2010-01-01

    How individuals deal with multiple conflicting demands is an important aspect of foraging ecology, yet work on foraging behavior has typically neglected neurologically simple organisms. Here we examine the impact of an abiotic risk (light) and energetic status on the foraging decisions of a protist, the slime mold Physarum polycephalum. We examined patch choice in a "non-risky" environment by presenting starved and non-starved P. polycephalum amoebas with a choice between two shaded food patches (one high quality, one low quality). We next examined patch choice in the presence of a conflict between foraging risk (light exposure) and food quality by presenting amoebas with a choice between a shaded, low-quality patch, and a light-exposed, high-quality patch. When both patches were shaded, 100% of amoebas selected the higher quality food patch, irrespective of food-quality differences or the individual's energetic status. When light exposure and food quality conflicted, amoebas selected the patch with the higher food quality when the quality difference between the patches was high. When the quality difference between patches was small, amoebas selected the shaded, lower quality patch.

  19. Larval and post-larval stages of Pacific oyster (Crassostrea gigas are resistant to elevated CO2.

    Directory of Open Access Journals (Sweden)

    Ko W K Ginger

    Full Text Available The average pH of surface oceans has decreased by 0.1 unit since industrialization and is expected to decrease by another 0.3-0.7 units before the year 2300 due to the absorption of anthropogenic CO2. This human-caused pH change is posing serious threats and challenges to the Pacific oyster (Crassostrea gigas, especially to their larval stages. Our knowledge of the effect of reduced pH on C. gigas larvae presently relies presumptively on four short-term (<4 days survival and growth studies. Using multiple physiological measurements and life stages, the effects of long-term (40 days exposure to pH 8.1, 7.7 and 7.4 on larval shell growth, metamorphosis, respiration and filtration rates at the time of metamorphosis, along with the juvenile shell growth and structure of the C. gigas, were examined in this study. The mean survival and growth rates were not affected by pH. The metabolic, feeding and metamorphosis rates of pediveliger larvae were similar, between pH 8.1 and 7.7. The pediveligers at pH 7.4 showed reduced weight-specific metabolic and filtration rates, yet were able to sustain a more rapid post-settlement growth rate. However, no evidence suggested that low pH treatments resulted in alterations to the shell ultrastructures (SEM images or elemental compositions (i.e., Mg/Ca and Sr/Ca ratios. Thus, larval and post-larval forms of the C. gigas in the Yellow Sea are probably resistant to elevated CO2 and decreased near-future pH scenarios. The pre-adapted ability to resist a wide range of decreased pH may provide C. gigas with the necessary tolerance to withstand rapid pH changes over the coming century.

  20. Estimation of food limitation of bivalve larvae in coastal waters of north-western Europe

    DEFF Research Database (Denmark)

    Bos, O.G.; Hendriks, I.E.; Strasser, M.;

    2006-01-01

    Marine invertebrate recruitment may be affected by food limitation during the pelagic larval life stages. In the present study, field data on abundance of bivalve larvae along with their prey (small phytoplankton) were examined to see whether they were consistent with predictions made by an energ...... assimilation rate averaged 7-26% of the maximum assimilation rate. Under the assumptions made for the present study, it is suggested that growth of larvae in north-west European waters is often food-limited. (c) 2005 Elsevier B.V. All rights reserved...

  1. Seasonal variations in larval biomass and biochemical composition of brown shrimp, Crangon crangon (Decapoda, Caridea), at hatching

    Science.gov (United States)

    Urzúa, Ángel; Anger, Klaus

    2013-06-01

    The "brown shrimp", Crangon crangon (Linnaeus 1758), is a benthic key species in the North Sea ecosystem, supporting an intense commercial fishery. Its reproductive pattern is characterized by a continuous spawning season from mid-winter to early autumn. During this extended period, C. crangon shows significant seasonal variations in egg size and embryonic biomass, which may influence larval quality at hatching. In the present study, we quantified seasonal changes in dry weight (W) and chemical composition (CHN, protein and lipid) of newly hatched larvae of C. crangon. Our data revealed significant variations, with maximum biomass values at the beginning of the hatching season (February-March), a decrease throughout spring (April-May) and a minimum in summer (June-September). While all absolute values of biomass and biochemical constituents per larva showed highly significant differences between months ( P additive models (GAM), key variables of embryonic development exerted significant effects on larval condition at hatching: The larval carbon content (C) was positively correlated with embryonic carbon content shortly after egg-laying ( r 2 = 0.60; P Additionally, water temperature ( r 2 = 0.57; P food availability (phytoplankton C; r 2 = 0.39; P effects persisting from the embryonic to the larval phase. Since "winter larvae" are more likely exposed to poor nutritional conditions, intraspecific variability in larval biomass at hatching is interpreted as part of an adaptive reproductive strategy compensating for strong seasonality in plankton production and transitory periods of larval food limitation.

  2. Factors related to fruit, vegetable and traditional food consumption which may affect health among Alaska Native People in Western Alaska

    Directory of Open Access Journals (Sweden)

    Jennifer S. Johnson

    2012-03-01

    Full Text Available Objectives: Determine intake of fruits, vegetables and traditional foods (TF, availability of foods, and attitudes towards increasing their consumption. Study design: Establish community baseline through a cross-sectional sample of residents who were weighed, measured and interviewed. Village stores were surveyed for food availability, price and quality. Methods: Eighty-eight respondents self-identified as the household member primarily responsible for food shopping and cooking were surveyed in 3 Western Alaska Native villages using a food frequency questionnaire, and village stores were evaluated using food environment surveys. Results: Overweight (BMI[kg/m2] > 25 was present in 68% of participants. Fruit and vegetable intake (3.3 median servings/day was low in comparison to recommended intakes of 5–9 servings/d. Seventy-two per cent were eating less than 5 servings/d of fruits and vegetables combined. Thirty-four per cent of respondents were trying to eat more vegetables; 41% were trying to eat more fruits. The median number of servings of TF was 3.2/d (mean 4.3/d. Seventy-seven per cent of respondents reported that they ate enough TF. Conclusion: Recommendations to continue use of TF and increase intake of fruits and vegetables are consistent with local attitudes. Our findings indicate that increasing the availability of fruits and vegetables would be well received. Information from this study provides a basis for nutrition education and food supplement programs that is responsive to the needs and perceptions of the residents. Continued TF intake and increased fruit and vegetable intake have the potential to benefit the health of rural residents.

  3. Factors related to fruit, vegetable and traditional food consumption which may affect health among Alaska Native People in Western Alaska

    Science.gov (United States)

    Johnson, Jennifer S.; Nobmann, Elizabeth D.; Asay, Elvin

    2012-01-01

    Objectives Determine intake of fruits, vegetables and traditional foods (TF), availability of foods, and attitudes towards increasing their consumption. Study design Establish community baseline through a cross-sectional sample of residents who were weighed, measured and interviewed. Village stores were surveyed for food availability, price and quality. Methods Eighty-eight respondents self-identified as the household member primarily responsible for food shopping and cooking were surveyed in 3 Western Alaska Native villages using a food frequency questionnaire, and village stores were evaluated using food environment surveys. Results Overweight (BMI[kg/m2] >25) was present in 68% of participants. Fruit and vegetable intake (3.3 median servings/day) was low in comparison to recommended intakes of 5–9 servings/d. Seventy-two per cent were eating less than 5 servings/d of fruits and vegetables combined. Thirty-four per cent of respondents were trying to eat more vegetables; 41% were trying to eat more fruits. The median number of servings of TF was 3.2/d (mean 4.3/d). Seventy-seven per cent of respondents reported that they ate enough TF. Conclusion Recommendations to continue use of TF and increase intake of fruits and vegetables are consistent with local attitudes. Our findings indicate that increasing the availability of fruits and vegetables would be well received. Information from this study provides a basis for nutrition education and food supplement programs that is responsive to the needs and perceptions of the residents. Continued TF intake and increased fruit and vegetable intake have the potential to benefit the health of rural residents. PMID:22456043

  4. Effects of stocking-density in flow-through system on the mussel Perna perna larval survival

    Directory of Open Access Journals (Sweden)

    Caio Silva Turini

    2014-07-01

    Full Text Available This study evaluated the effects of larval densities, cultured in flow-through system, in the yield and quantity of larvae. The first experiment compared the larval yield of a flow­through system (80 larvae mL-1 and a batch system (8 larvae mL-1, which resulted in a higher yield and number of larvae in the flow­through system, after 23 days. The second experiment compared two larval densities (20 and 45 larvae mL-1 in flow­through system. The densities affected the yield after 15 and 23 days and the larvae final quantity after all tested times (8, 15, and 23 days. After 23 days of larviculture, the yield was highest for 20 larvae mL-1 and the larval number for 45 larvae mL-1. The third experiment also compared two larval densities (100 and 150 larvae mL-1 in flow­through system. The larvae densities did not affect the yield and number of larvae for all tested times (8, 15, and 23 days. In general, the yield has reduced at higher larval densities. Therefore, considering the number of suitable larvae for settlement, the flow-through system was more efficient than the static system. However, in general, we observed reduced yield with high larval stocking-density in flow-through system.

  5. Nutritional value-dependent and nutritional value-independent effects on Drosophila melanogaster larval behavior.

    Science.gov (United States)

    Rohwedder, Astrid; Pfitzenmaier, Johanna E; Ramsperger, Noel; Apostolopoulou, Anthi A; Widmann, Annekathrin; Thum, Andreas S

    2012-10-01

    Gustatory stimuli allow an organism not only to orient in its environment toward energy-rich food sources to maintain nutrition but also to avoid unpleasant or even poisonous substrates. For both mammals and insects, sugars-perceived as "sweet"-potentially predict nutritional benefit. Interestingly, even Drosophila adult flies are attracted to most high-potency sweeteners preferred by humans. However, the gustatory information of a sugar may be misleading as some sugars, although perceived as "sweet," cannot be metabolized. Accordingly, in adult Drosophila, a postingestive system that additionally evaluates the nutritional benefit of an ingested sugar has been shown to exist. By using a set of seven different sugars, which either offer (fructose, sucrose, glucose, maltodextrin, and sorbitol) or lack (xylose and arabinose) nutritional benefit, we show that Drosophila, at the larval stage, can perceive and evaluate sugars based on both nutrition-dependent and -independent qualities. In detail, we find that larval survival and feeding mainly depend on the nutritional value of a particular sugar. In contrast, larval choice behavior and learning are regulated in a more complex way by nutrition value-dependent and nutrition value-independent information. The simplicity of the larval neuronal circuits and their accessibility to genetic manipulation may ultimately allow one to identify the neuronal and molecular basis of the larval sugar perception systems described here behaviorally.

  6. Ocean acidification alters temperature and salinity preferences in larval fish.

    Science.gov (United States)

    Pistevos, Jennifer C A; Nagelkerken, Ivan; Rossi, Tullio; Connell, Sean D

    2017-02-01

    Ocean acidification alters the way in which animals perceive and respond to their world by affecting a variety of senses such as audition, olfaction, vision and pH sensing. Marine species rely on other senses as well, but we know little of how these might be affected by ocean acidification. We tested whether ocean acidification can alter the preference for physicochemical cues used for dispersal between ocean and estuarine environments. We experimentally assessed the behavioural response of a larval fish (Lates calcarifer) to elevated temperature and reduced salinity, including estuarine water of multiple cues for detecting settlement habitat. Larval fish raised under elevated CO2 concentrations were attracted by warmer water, but temperature had no effect on fish raised in contemporary CO2 concentrations. In contrast, contemporary larvae were deterred by lower salinity water, where CO2-treated fish showed no such response. Natural estuarine water-of higher temperature, lower salinity, and containing estuarine olfactory cues-was only preferred by fish treated under forecasted high CO2 conditions. We show for the first time that attraction by larval fish towards physicochemical cues can be altered by ocean acidification. Such alterations to perception and evaluation of environmental cues during the critical process of dispersal can potentially have implications for ensuing recruitment and population replenishment. Our study not only shows that freshwater species that spend part of their life cycle in the ocean might also be affected by ocean acidification, but that behavioural responses towards key physicochemical cues can also be negated through elevated CO2 from human emissions.

  7. Inaccessible food cues affect stress and weight gain in calorically-restricted and ad lib fed rats.

    Science.gov (United States)

    Coelho, Jennifer S; Polivy, Janet; Fleming, Alison; Hargreaves, Duane; Herman, C Peter; Lao, Grace

    2010-02-01

    Research suggests that caloric restriction (CR) is beneficial; however, the effects of CR in the context of food cues are unclear. A 2 (food cue vs. no cue)x2 (CR vs. ad lib) between-subjects design was employed to test these effects in 40 rats. It was predicted that cue exposure and CR would induce stress, and that these factors might interact synergistically. The results demonstrated that cue-exposed CR rats weighed less than did non-exposed CR rats. A blunted stress response was evident in CR rats relative to ad lib rats. Finally, cue-exposed rats had higher corticosterone levels and body weight during ad lib feeding than did non-cued rats. These results suggest that both CR and chronic food-cue exposure can be stressful, and the implications of this research are discussed in the context of humans' 'obesigenic' environment. 2009 Elsevier Ltd. All rights reserved.

  8. How does consumer knowledge affect environmentally sustainable choices? Evidence from a cross-country latent class analysis of food labels.

    Science.gov (United States)

    Peschel, Anne O; Grebitus, Carola; Steiner, Bodo; Veeman, Michele

    2016-11-01

    This paper examines consumers' knowledge and lifestyle profiles and preferences regarding two environmentally labeled food staples, potatoes and ground beef. Data from online choice experiments conducted in Canada and Germany are analyzed through latent class choice modeling to identify the influence of consumer knowledge (subjective and objective knowledge as well as usage experience) on environmentally sustainable choices. We find that irrespective of product or country under investigation, high subjective and objective knowledge levels drive environmentally sustainable food choices. Subjective knowledge was found to be more important in this context. Usage experience had relatively little impact on environmentally sustainable choices. Our results suggest that about 20% of consumers in both countries are ready to adopt footprint labels in their food choices. Another 10-20% could be targeted by enhancing subjective knowledge, for example through targeted marketing campaigns.

  9. Experimental parameters differentially affect the humoral response of the cholera-toxin-based murine model of food allergy

    DEFF Research Database (Denmark)

    Kroghsbo, S.; Christensen, Hanne Risager; Frøkiær, Hanne

    2003-01-01

    Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle immunomodu......Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle...

  10. Changing how I feel about the food: experimentally manipulated affective associations with fruits change fruit choice behaviors.

    Science.gov (United States)

    Walsh, Erin M; Kiviniemi, Marc T

    2014-04-01

    Fewer than half of Americans meet current recommendations for fruit and vegetable intake. The behavioral affective associations model posits that feelings and emotions associated with a behavior are a proximal influence on decision making. Cross-sectional evidence supports the model and suggests that affective associations predict fruit and vegetable consumption. The purpose of this study was to test whether a causal relation exists between affective associations about fruits and future fruit consumption behavior, as measured by a snack selection task. Following a baseline assessment of cognitive and affective variables, participants' (N = 161) affective associations about fruits were experimentally manipulated with an implicit priming paradigm. Images of fruits were repeatedly paired with positive, negative, or neutral affective stimuli. The key outcome measure was a behavioral choice task in which participants chose between fruit and a granola bar. Participants in the positive prime condition were three times more likely than those in the negative condition to select a piece of fruit over the granola bar alternative in the snack selection task. They were also twice as likely as those in the neutral condition to select fruit. There were no changes in self-reported affective associations or cognitive beliefs. These findings provide further evidence of the implicit and direct influence of affective associations on behavior, suggesting the need to both incorporate the role of affect in health decision making models, as well as the potential utility of intervention strategies targeting affective associations with health-related behaviors.

  11. Does Food Insecurity at Home Affect Non-Cognitive Performance at School? A Longitudinal Analysis of Elementary Student Classroom Behavior

    Science.gov (United States)

    Howard, Larry L.

    2011-01-01

    This paper estimates models of the transitional effects of food insecurity experiences on children's non-cognitive performance in school classrooms using a panel of 4710 elementary students enrolled in 1st, 3rd, and 5th grade (1999-2003). In addition to an extensive set of child and household-level characteristics, we use information on U.S.…

  12. Selected gelling agents in canned dog food affect nutrient digestibilities and fecal characteristics of ileal cannulated dogs

    NARCIS (Netherlands)

    Karr-Lilienthal, L.K.; Merchen, N.R.; Grieshop, C.M.; Smeets-Petersen, M.J.E.; Fahey, G.C.

    2002-01-01

    Little is known about the effects of gelling agents in canned dog food on nutrient digestibilities and fecal characteristics. Dogs were fed canned diets with either no gelling agent (control) or one of three gelling agents, wheat starch, a guar gum/carrageenan mixture (50:50), and a locust bean meal

  13. How Tactile and Function Information Affect Young Children's Ability to Understand the Nature of Food-Appearing, Deceptive Objects

    Science.gov (United States)

    Krause, Christina Miles

    2008-01-01

    Preschool children's (N = 64) ability to use tactile information and function cues on less-realistic and more-realistic food-appearing, deceptive objects was examined before and after training on the function of deceptive objects. They also responded to appearance and reality questions about deceptive objects. Half of the children (F-S:…

  14. Food matrices affect the bioavailability of (n-3) polyunsaturated fatty acids in a single meal study in humans

    DEFF Research Database (Denmark)

    Schram, Laurine B; Nielsen, Carina J.; Porsgaard, Trine

    2007-01-01

    , a yoghurt drink, eight oil capsules, bread and butter; 4 g of fish oil was incorporated into one of the matrices. Blood samples were collected and fatty acid composition of chylomicrons was determined together with plasma levels of conjugated dienes and alpha-tocopherol. Fish oil incorporated into food...

  15. How Tactile and Function Information Affect Young Children's Ability to Understand the Nature of Food-Appearing, Deceptive Objects

    Science.gov (United States)

    Krause, Christina Miles

    2008-01-01

    Preschool children's (N = 64) ability to use tactile information and function cues on less-realistic and more-realistic food-appearing, deceptive objects was examined before and after training on the function of deceptive objects. They also responded to appearance and reality questions about deceptive objects. Half of the children (F-S:…

  16. Nesfatin-130-59 Injected Intracerebroventricularly Differentially Affects Food Intake Microstructure in Rats Under Normal Weight and Diet-Induced Obese Conditions.

    Science.gov (United States)

    Prinz, Philip; Teuffel, Pauline; Lembke, Vanessa; Kobelt, Peter; Goebel-Stengel, Miriam; Hofmann, Tobias; Rose, Matthias; Klapp, Burghard F; Stengel, Andreas

    2015-01-01

    Nesfatin-1 is well-established to induce an anorexigenic effect. Recently, nesfatin-130-59, was identified as active core of full length nesfatin-11-82 in mice, while its role in rats remains unclear. Therefore, we investigated the effects of nesfatin-130-59 injected intracerebroventricularly (icv) on the food intake microstructure in rats. To assess whether the effect was also mediated peripherally we injected nesfatin-130-59 intraperitoneally (ip). Since obesity affects the signaling of various food intake-regulatory peptides we investigated the effects of nesfatin-130-59 under conditions of diet-induced obesity (DIO). Male Sprague-Dawley rats fed ad libitum with standard diet were icv cannulated and injected with vehicle (5 μl ddH2O) or nesfatin-130-59 at 0.37, 1.1, and 3.3 μg (0.1, 0.3, 0.9 nmol/rat) and the food intake microstructure assessed using a food intake monitoring system. Next, naïve rats were injected ip with vehicle (300 μl saline) or nesfatin-130-59 (8.1, 24.3, 72.9 nmol/kg). Lastly, rats were fed a high fat diet for 10 weeks and those developing DIO were icv cannulated. Nesfatin-1 (0.9 nmol/rat) or vehicle (5 μl ddH2O) was injected icv and the food intake microstructure assessed. In rats fed standard diet, nesfatin-130-59 caused a dose-dependent reduction of dark phase food intake reaching significance at 0.9 nmol/rat in the period of 4-8 h post injection (-29%) with the strongest reduction during the fifth hour (-75%), an effect detectable for 24 h (-12%, p food intake. In DIO rats fed high fat diet, nesfatin-130-59 injected icv reduced food intake in the third hour post injection (-71%), an effect due to a reduced meal frequency (-27%, p food intake in rats. The anorexigenic effect depends on the metabolic condition with increased satiation (reduction in meal size) under normal weight conditions, while in DIO rats satiety (reduction in meal frequency) is induced.

  17. Social modeling of eating: a review of when and why social influence affects food intake and choice.

    Science.gov (United States)

    Cruwys, Tegan; Bevelander, Kirsten E; Hermans, Roel C J

    2015-03-01

    A major determinant of human eating behavior is social modeling, whereby people use others' eating as a guide for what and how much to eat. We review the experimental studies that have independently manipulated the eating behavior of a social referent (either through a live confederate or remotely) and measured either food choice or intake. Sixty-nine eligible experiments (with over 5800 participants) were identified that were published between 1974 and 2014. Speaking to the robustness of the modeling phenomenon, 64 of these studies have found a statistically significant modeling effect, despite substantial diversity in methodology, food type, social context and participant demographics. In reviewing the key findings from these studies, we conclude that there is limited evidence for a moderating effect of hunger, personality, age, weight or the presence of others (i.e., where the confederate is live vs. remote). There is inconclusive evidence for whether sex, attention, impulsivity and eating goals moderate modeling, and for whether modeling of food choice is as strong as modeling of food intake. Effects with substantial evidence were: modeling is increased when individuals desire to affiliate with the model, or perceive themselves to be similar to the model; modeling is attenuated (but still significant) for healthy-snack foods and meals such as breakfast and lunch, and modeling is at least partially mediated through behavioral mimicry, which occurs without conscious awareness. We discuss evidence suggesting that modeling is motivated by goals of both affiliation and uncertainty-reduction, and outline how these might be theoretically integrated. Finally, we argue for the importance of taking modeling beyond the laboratory and bringing it to bear on the important societal challenges of obesity and disordered eating. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Anopheline larval habitats seasonality and species distribution: a prerequisite for effective targeted larval habitats control programmes.

    Directory of Open Access Journals (Sweden)

    Eliningaya J Kweka

    Full Text Available BACKGROUND: Larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. Understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. This study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western Kenya. METHODS AND FINDINGS: A total of 51 aquatic habitats positive for anopheline larvae were surveyed and visited once a week for a period of 85 weeks in succession. Habitats were selected and identified. Mosquito larval species, physico-chemical parameters, habitat size, grass cover, crop cycle and distance to nearest house were recorded. Polymerase chain reaction revealed that An. gambiae s.l was the most dominant vector species comprised of An.gambiae s.s (77.60% and An.arabiensis (18.34%, the remaining 4.06% had no amplification by polymerase chain reaction. Physico-chemical parameters and habitat size significantly influenced abundance of An. gambiae s.s (P = 0.024 and An. arabiensis (P = 0.002 larvae. Further, larval species abundance was influenced by crop cycle (P≤0.001, grass cover (P≤0.001, while distance to nearest houses significantly influenced the abundance of mosquito species larvae (r = 0.920;P≤0.001. The number of predator species influenced mosquito larval abundance in different habitat types. Crop weeding significantly influenced with the abundance of An.gambiae s.l (P≤0.001 when preceded with fertilizer application. Significantly higher anopheline larval abundance was recorded in habitats in pasture compared to farmland (P = 0.002. When habitat stability and habitat types were considered, hoof print were the most productive followed by disused goldmines. CONCLUSION: These findings suggest that implementation of effective larval

  19. The larval alimentary canal of the Antarctic insect, Belgica antarctica.

    Science.gov (United States)

    Nardi, James B; Miller, Lou Ann; Bee, Charles Mark; Lee, Richard E; Denlinger, David L

    2009-09-01

    On the Antarctica continent the wingless midge, Belgica antarctica (Diptera, Chironomidae) occurs further south than any other insect. The digestive tract of the larval stage of Belgica that inhabits this extreme environment and feeds in detritus of penguin rookeries has been described for the first time. Ingested food passes through a foregut lumen and into a stomodeal valve representing an intussusception of the foregut into the midgut. A sharp discontinuity in microvillar length occurs at an interface separating relatively long microvilli of the stomodeal midgut region, the site where peritrophic membrane originates, from the midgut epithelium lying posterior to this stomodeal region. Although shapes of cells along the length of this non-stomodeal midgut epithelium are similar, the lengths of their microvilli increase over two orders of magnitude from anterior midgut to posterior midgut. Infoldings of the basal membranes also account for a greatly expanded interface between midgut cells and the hemocoel. The epithelial cells of the hindgut seem to be specialized for exchange of water with their environment, with the anterior two-thirds of the hindgut showing highly convoluted luminal membranes and the posterior third having a highly convoluted basal surface. The lumen of the middle third of the hindgut has a dense population of resident bacteria. Regenerative cells are scattered throughout the larval midgut epithelium. These presumably represent stem cells for the adult midgut, while a ring of cells, marked by a discontinuity in nuclear size at the midgut-hindgut interface, presumably represents stem cells for the adult hindgut.

  20. Integrated mosquito larval source management reduces larval numbers in two highland villages in western Kenya

    Directory of Open Access Journals (Sweden)

    Imbahale Susan S

    2012-05-01

    Full Text Available Abstract Background In western Kenya, malaria remains one of the major health problems and its control remains an important public health measure. Malaria control is by either use of drugs to treat patients infected with malaria parasites or by controlling the vectors. Vector control may target the free living adult or aquatic (larval stages of mosquito. The most commonly applied control strategies target indoor resting mosquitoes. However, because mosquitoes spend a considerable time in water, targeting the aquatic stages can complement well with existing adult control measures. Methods Larval source management (LSM of malaria vectors was examined in two villages i.e. Fort Ternan and Lunyerere, with the aim of testing strategies that can easily be accessed by the affected communities. Intervention strategies applied include environmental management through source reduction (drainage of canals, land levelling or by filling ditches with soil, habitat manipulation (by provision of shading from arrow root plant, application of Bacillus thuringiensis var israelensis (Bti and the use of predatory fish, Gambusia affinis. The abundance of immature stages of Anopheles and Culex within intervention habitats was compared to that within non-intervention habitats. Results The findings show that in Fort Ternan no significant differences were observed in the abundance of Anopheles early and late instars between intervention and non-intervention habitats. In Lunyerere, the abundance of Anopheles early instars was fifty five times more likely to be present within non-intervention habitats than in habitats under drainage. No differences in early instars abundance were observed between non-intervention and habitats applied with Bti. However, late instars had 89 % and 91 % chance of being sampled from non-intervention rather than habitats under drainage and those applied with Bti respectively. Conclusion Most of these interventions were applied in habitats

  1. Effects of food variability on growth and reproduction of Aedes aegypti.

    Science.gov (United States)

    Zeller, Michael; Koella, Jacob C

    2016-01-01

    Despite a large body of knowledge about the evolution of life histories, we know little about how variable food availability during an individual's development affects its life history. We measured the effects of manipulating food levels during early and late larval development of the mosquito Aedes aegypti on its growth rate, life history and reproductive success. Switching from low to high food led to compensatory growth: individuals grew more rapidly during late larval development and emerged at a size close to that of mosquitoes consistently reared at high food. However, switching to high food had very little effect on longevity, and fecundity and reproductive success were considerably lower than in consistently well-fed mosquitoes. Changing from high to low food led to adults with similar size as in consistently badly nourished mosquitoes, but even lower fecundity and reproductive success. A rapid response of growth to changing resources can thus have unexpected effects in later life and in lifetime reproductive success. More generally, our study emphasizes the importance of varying developmental conditions for the evolutionary pressures underlying life-history evolution.

  2. Ecological Support of Larval Fish During Multigenerational Studies on Space Station

    Science.gov (United States)

    Taub, Frieda B.

    1998-01-01

    Live, microscopic food is required by larval Zebrafish, Danio rerio, which are candidates for the Aquatic Habitat of the Space Station Biological Research Project (SSBRP). Zebrafish have proven to be convenient research animals, and their embryology and genetics are extensively documented. Their ability to mature at 3 months of age, and the transparent eggs which hatches in 2 days, are attractive attributes for space research. Among the goals of the SSBRP Aquatic Habitat is the ability to study three generations, with the objective of maintaining adults, their offspring, and the maintaining of these offspring through maturity and spawning. For Zebrafish, it is anticipated that sexually mature fish (PI) would be delivered to Space Station and spawned in space. The challenge would be it to provide appropriate microscopic foods for the offspring (FI), and 3 months later for the next generation (F2); if these were raised to maturity and bred, live foods would be required at approximately 6 months. In laboratories where Zebrafish are traditionally reared, the larval foods are the protozoan Parameciwn micromultinucleatwn and later brine shrimp Artemia nauplii. Under normal laboratory conditions, the rearing of these foods are relatively easy, although time consuming because of the food organisms must be separated from their rearing medium which is discarded. A freshwater food chain that would ensur-e healthy on- orbit research animals is needed. ne food chain should (a) be reared in conditions that are compatible with the larval fish (water chemistry, pH, temperature and light), (b) assist in maintaining water quality (by removing ammonia, nitrate, phosphate, carbon dioxide, and bacteria) and (c) be convenient for the space crew (minimize handling and waste production).

  3. An obesity-associated risk allele within the FTO gene affects human brain activity for areas important for emotion, impulse control and reward in response to food images.

    Science.gov (United States)

    Wiemerslage, Lyle; Nilsson, Emil K; Solstrand Dahlberg, Linda; Ence-Eriksson, Fia; Castillo, Sandra; Larsen, Anna L; Bylund, Simon B A; Hogenkamp, Pleunie S; Olivo, Gaia; Bandstein, Marcus; Titova, Olga E; Larsson, Elna-Marie; Benedict, Christian; Brooks, Samantha J; Schiöth, Helgi B

    2016-05-01

    Understanding how genetics influences obesity, brain activity and eating behaviour will add important insight for developing strategies for weight-loss treatment, as obesity may stem from different causes and as individual feeding behaviour may depend on genetic differences. To this end, we examined how an obesity risk allele for the FTO gene affects brain activity in response to food images of different caloric content via functional magnetic resonance imaging (fMRI). Thirty participants homozygous for the rs9939609 single nucleotide polymorphism were shown images of low- or high-calorie food while brain activity was measured via fMRI. In a whole-brain analysis, we found that people with the FTO risk allele genotype (AA) had increased activity compared with the non-risk (TT) genotype in the posterior cingulate, cuneus, precuneus and putamen. Moreover, higher body mass index in the AA genotype was associated with reduced activity to food images in areas important for emotion (cingulate cortex), but also in areas important for impulse control (frontal gyri and lentiform nucleus). Lastly, we corroborate our findings with behavioural scales for the behavioural inhibition and activation systems. Our results suggest that the two genotypes are associated with differential neural processing of food images, which may influence weight status through diminished impulse control and reward processing.

  4. A comparison of Aedes vigilax larval population densities and associated vegetation categories in a coastal wetland, Northern Territory, Australia.

    Science.gov (United States)

    Jacups, S P; Kurucz, N; Whelan, P I; Carter, J M

    2009-12-01

    Darwin's northern suburbs border an extensive coastal reed and upper mangrove wetland recognized as an important larval habitat for Aedes vigilax (Skuse), the northern salt marsh mosquito, an established vector for Ross River and Barmah Forest viruses and an appreciable pest species. We sought to identify the most important vegetation categories associated with Ae. vigilax breeding to maximize the efficiency of mosquito control efforts. Using a generalized linear model with negative binominal distribution and log link, this study compares larval densities, determined by focused dipping, between 13 discernable vegetation categories. The incidence rate ratios (RR) generated can be used to compare the magnitude of larval densities for each vegetation category, compared with the reference category. Aedes vigilax larval densities were almost ten times greater in artificial drainage areas (RR=9.82), followed by tide-affected reticulate (Sporobolus/Xerochloa) areas (RR=8.15), then Schoenoplectus/mangroves (RR=2.29), compared with the reference vegetation category "lower mangroves." Furthermore, larval densities were highest in May, due to tidal inundation, for drainage areas and tide-affected reticulates (RR=12.2, 11.7, respectively) compared with March, the reference month. Thus, to maximize the efficiency of aerial salt marsh mosquito control operations in this wetland, larval control is best accomplished by concentrating on drains, Schoenoplectus/mangroves, and tide-affected reticulate areas, commencing early after the wet season. These results should apply to other areas of salt marsh mosquito breeding across northern Australia.

  5. Feeding of potato, tomato and eggplant alkaloids affects food consumption and body and liver weights in mice.

    Science.gov (United States)

    Friedman, M; Henika, P R; Mackey, B E

    1996-04-01

    Reduced liver weight was used to evaluate the potential toxicity in mice of four naturally occurring steroidal glycoalkaloids: alpha-chaconine and alpha-solanine, alpha-tomatine and solasonine. Increased liver weights was used to evaluate the three corresponding steroidal aglycones: solanidine, tomatidine, and solasodine and the non-alkaloid adrenal steroid dehydroepiandrosterone (DHEA). Adult female Swiss-Webster mice were fed diets containing test compound concentrations of 0 (control), 1.2, 2.4 or 4.8 mmol/kg diet for 7, 14 or 28 d. Absolute liver weights (LW) and relative liver weights (liver weight/body weight x 100, %LW/BW) were determined at autopsy. The %LW/BW was lower than that of controls in mice fed the potato glycoalkaloid alpha-chaconine (-10%, P toxic ++compounds from plant foods. The implications of the results for food safety and health are discussed.

  6. Rehydration of forensically important larval Diptera specimens.

    Science.gov (United States)

    Sanford, Michelle R; Pechal, Jennifer L; Tomberlin, Jeffery K

    2011-01-01

    Established procedures for collecting and preserving evidence are essential for all forensic disciplines to be accepted in court and by the forensic community at large. Entomological evidence, such as Diptera larvae, are primarily preserved in ethanol, which can evaporate over time, resulting in the dehydration of specimens. In this study, methods used for rehydrating specimens were compared. The changes in larval specimens with respect to larval length and weight for three forensically important blow fly (Diptera: Calliphoridae) species in North America were quantified. Phormia regina (Meigen), Cochliomyia macellaria (F.), and Chrysomya rufifacies (Macquart) third-instar larvae were collected from various decomposing animals and preserved with three preservation methods (80% ethanol, 70% isopropyl alcohol, and hot-water kill then 80% ethanol). Preservative solutions were allowed to evaporate. Rehydration was attempted with either of the following: 80% ethanol, commercial trisodium phosphate substitute solution, or 0.5% trisodium phosphate solution. All three methods partially restored weight and length of specimens recorded before preservation. Analysis of variance results indicated that effects of preservation, rehydration treatment, and collection animal were different in each species. The interaction between preservative method and rehydration treatment had a significant effect on both P. regina and C. macellaria larval length and weight. In addition, there was a significant interaction effect of collection animal on larval C. macellaria measurements. No significant effect was observed in C. rufifacies larval length or weight among the preservatives or treatments. These methods could be used to establish a standard operating procedure for dealing with dehydrated larval specimens in forensic investigations.

  7. How does shape affect predator- prey interactions in fish? Implications for marine food web structure and dynamics

    OpenAIRE

    Cachera, Marie; Villanueva, Ching-maria; Ernande, Bruno; Baheux, Mickael; Rouquette, Manuel; Chambord, Sophie; Lefebvre, Sebastien

    2011-01-01

    Each species pertains to a given functional niche, depending on its relationships with others species and its interactions with the abiotic environment. Understanding inter-specific interactions is critical to know and predict ecosystems' structure, functioning and dynamics, but also their response to anthropogenic impacts. Predator-prey relationship is one of the main biotic interactions as it both determines the survival of the prey and the predator and is the keystone of food webs. Unra...

  8. Factors affecting food choices of older adults from high and low socioeconomic groups: a discrete choice experiment.

    Science.gov (United States)

    Kamphuis, Carlijn B M; de Bekker-Grob, Esther W; van Lenthe, Frank J

    2015-04-01

    Healthiness, price, and convenience are typically indicated as important motives for food choices; however, it is largely unknown to what extent older adults from high and low socioeconomic groups differ in these underlying motives. A discrete choice experiment (DCE) is an innovative way to elicit implicit motives for food choices. The aim was to investigate differences in food motives between socioeconomic groups by means of a DCE. A DCE was carried out during a face-to-face interview among older adults as part of the Health and Living Conditions in Eindhoven and surrounding cities (GLOBE) cohort study, The Netherlands. Participants (n = 399; mean age: 63.3 y) were offered a series of choice sets about a usual dinner at home and were asked to choose in each choice set between 2 meals and an opt-out choice, with different combinations of attribute levels. We included 5 meal attributes (taste, healthiness, preparation time, travel time to shops, and price) and 3 or 4 levels for each attribute. Data were analyzed by multinomial logit models. Healthiness, taste, price, and travel time to the grocery store proved to significantly influence older adults' meal decisions; preparation time was not significant. Healthiness was the most important attribute for all of the participants. More highly educated participants rated a healthy and less expensive meal to be more important than did less educated participants. Those with a high income rated a meal that was healthy and very tasteful to be more important than did those with a lower income. Healthiness, taste, price, and travel time to grocery shops influenced older adults' meal decisions. Higher socioeconomic groups valued health more than did lower socioeconomic groups. DCEs represent a promising method to gain insight into the relative importance of motives for food choices. This trial was registered at www.isrctn.com as ISRCTN60293770. © 2015 American Society for Nutrition.

  9. Are we positively or negatively affected? : A study on how people react to food-related communication messages

    OpenAIRE

    PETROVIC, ANA; Hammer, Emma

    2016-01-01

    Background- Communication messages today are all about influencing and persuading people. Two main types of messages can be seen when studying the healthy food trend on Instagram and how it is impacting attitude formation and change; these two are positive and negative messages. However, different communication messages are not the only deciders of attitude formation and change. There is one more significant factor that impacts attitude formation and change; this factor is identification with...

  10. 'Peer pressure' in larval Drosophila?

    National Research Council Canada - National Science Library

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

    2014-01-01

    .... Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing...

  11. Biosurgery: use of larvae of necrophage insects in wound healing. The larval therapy

    Directory of Open Access Journals (Sweden)

    Magda Carolina Sánchez

    2004-12-01

    Full Text Available Larval therapy is a technique that allows the useof larva of some diptera species on chronicwounds or localized infected focuses, in order topromote the affected tissue restoration. Thetreatment velocity and efficacy, with almost nohealthy tissue loses during the process, havemade larval therapy (sometimes calledbiosurgery a viable alternative for healingwounds associated with entities as diabetic foot,venous ulcers, cutaneous chronic ulcers andburns, and some benign tumors, abscesses andosteomyelitis.Although modern medicine has been, in manycases, reticent on the application of this kind oftherapies, events as antibiotic resistance andalterations in cicatrization process in chronicwounds, have modified the respective initialpoint of view of many doctors.

  12. Probiotic-enriched foods and dietary supplement containing SYNBIO positively affects bowel habits in healthy adults: an assessment using standard statistical analysis and Support Vector Machines.

    Science.gov (United States)

    Silvi, Stefania; Verdenelli, M Cristina; Cecchini, Cinzia; Coman, M Magdalena; Bernabei, M Simonetta; Rosati, Jessica; De Leone, Renato; Orpianesi, Carla; Cresci, Alberto

    2014-12-01

    A randomised, double-blind, placebo-controlled, parallel group study assessed in healthy adults how daily consumption of the probiotic combination SYNBIO®, administered in probiotic-enriched foods or in a dietary supplement, affected bowel habits. Primary and secondary outcomes gave the overall assessment of bowel well-being, while a Psychological General Well-Being Index compiled by participants estimated the health-related quality of life as well as the gastrointestinal tolerance determined with the Gastrointestinal Symptom Rating Scale. Support Vector Machine models for classification problems were used to validate the total outcomes on bowel well-being. SYNBIO® consumption improved bowel habits of volunteers consuming the probiotic foods or capsules, while the same effects were not registered in the control groups. The recovery of probiotic bacteria from the faeces of a cohort of 100 subjects for each supplemented group showed the persistence of strains in the gastrointestinal tract.

  13. Diatom production in the marine environment : implications for larval fish growth and condition

    DEFF Research Database (Denmark)

    St. John, Michael; Clemmesen, C.; Lund, T.

    2001-01-01

    to post-yolk-sac larval cod. Results indicate that larval growth rates are significantly influenced by the content of essential fatty acids of the algal food source: growth rates were positively correlated with the content of DHA (C22:6 omega0) and negatively with EPA (C20:5 omega3). The ratio of omega3....../omega6 fatty acids in the algal source had no significant effect. The highest and lowest growth rates were observed in food chains based on H. triquetra and T. weissflogii. respectively (means for days 14-16 of 4.0 and - 4.7). The mixed diatom/dinoflagellate diet resulted in inter- mediate growth rates...

  14. Interactive Effects of Endogenous and Exogenous Nutrition on Larval Development for Crown-Of-Thorns Starfish

    Directory of Open Access Journals (Sweden)

    Ciemon Frank Caballes

    2017-03-01

    Full Text Available Outbreaks of crown-of-thorns starfish are often attributed to step-changes in larval survivorship following anomalous increases in nutrients and food availability. However, larval growth and development is also influenced by the nutritional condition of spawning females, such that maternal provisioning may offset limitations imposed by limited access to exogenous sources of nutrients during the formative stages of larval development. This study examined the individual, additive, and interactive effects of endogenous (maternal diet: Acropora, Porites, mixed, and starved and exogenous (larval diet: high concentration at 104 cells·mL−1, low concentration at 103 algal cells·mL−1, and starved nutrition on the survival, growth, morphology, and development of larvae of the crown-of-thorns starfish. Female starfish on Acropora and mixed diet produced bigger oocytes compared to Porites-fed and starved treatments. Using oocyte size as a proxy for maternal provisioning, endogenous reserves in the oocyte had a strong influence on initial larval survival and development. This suggests that maternal reserves can delay the onset of obligate exogenous food acquisition and allow larvae to endure prolonged periods of poor environmental nutritive conditions or starvation. The influence of exogenous nutrition became more prominent in later stages, whereby none of the starved larvae reached the mid-to-late brachiolaria stage 16 days after the onset of the ability to feed. There was no significant difference in the survival, development, and competency of larvae between high and low food treatments. Under low algal food conditions, larvae compensate by increasing the length of ciliated feeding bands in relation to the maximum length and width, which improve food capture and feeding efficiency. However, the effects of endogenous nutrition persisted in the later developmental stages, as larvae from starved females were unable to develop larger feeding structures

  15. pH、盐度和不同饵料对咖啡金黄水母幼体生长与存活的影响%The effect of pH, salinity and food organism species on survival and growth of larval jellyfish Chrysaora melanaster

    Institute of Scientific and Technical Information of China (English)

    杨为东; 郭玲玲; 赵文; 滕利平; 杨担光; 张荣坤

    2011-01-01

    采用实验生态学方法研究了pH、盐度和不同饵料对观赏类水母--咖啡金黄水母Chrysaora melanaster幼体生长和存活的影响.结果表明:咖啡金黄水母幼体(伞径为2 cm)的适宜pH为7.3~8.8;盐度的生态幅为20~45;不同饵料条件下,第11天时饵料为卤虫无节幼体组与饵料为桡足类组的水母幼体的平均伞径有显著性差异(P<0.05),第16天时饵料为海月水母组与饵料为桡足类组的水母幼体的平均伞径有显著性差异(P<0.05),第20天时海月水母组的幼体生长最快,卤虫无节幼体组的次之,混合桡足类组的生长较慢.%Effects of pH, salinity and food organism species on survival and growth of larval jellyfish Chrysaora melanaster were studied by a ecological method. The maximal survival and best growth in the larvae were showed at pH of from 7.3 to 8.8, and a salinity from 20 to 45. There was significant difference in the test diameter in the jellyfish in Artemia group and copepoda group 11 days after the experiment, and 16 days after the experiemnt, significant difference in the growth performance between moon jellyfish group and copepoda group. The range of the fimbria diameter 20 days after feeding was arranged as the following as moon jellyfish group>Anemia group>mixed copepoda group.

  16. Low larval densities in northern populations reinforce range expansion by a Mediterranean damselfly

    DEFF Research Database (Denmark)

    Therry, Lieven; Swaegers, Janne; Dinh, Khuong Van

    2016-01-01

    towards the very edge of the expansion front has been neglected. Density effects may, however, have a profound direct impact on traits involved in range expansion and influence range dynamics. 2. In this study, we contrast the effects of high conspecific larval density typical for established populations...... and low larval density typical for newly founded populations at the edge of the expansion front on a set of larval traits that may affect the range dynamics in the poleward moving damselfly Coenagrion scitulum. We therefore ran an outdoor mesocosm experiment with a low- and high-density treatment close......, fat content and activity of phenoloxidase (PO)] was scored at the end of the winter period. 3. The low-density treatment had strong direct positive effects on survival, growth rate and body size of larvae before winter indicating relaxed competition. Lower foraging activity at the lowdensity treatment...

  17. Microbiological and biochemical characteristics of ground beef as affected by gamma irradiation, food additives and edible coating film

    Science.gov (United States)

    Ouattara, B.; Giroux, M.; Yefsah, R.; Smoragiewicz, W.; Saucier, L.; Borsa, J.; Lacroix, M.

    2002-03-01

    The current interest in "minimally processed foods" has attracted the attention for combination of mild treatments to improve food safety and shelf-life extention. The present study was conducted to evaluate the combined effect of gamma irradiation and incorporation of naturally occurring antimicrobial compounds on microbial and biochemistry characteristics of ground beef. Ground beef patties (23% fat ) were purchased from a local grocery store (IGA, Laval, Que., Canada) and divided into 3 separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid, and (iii) ground beef with 0.5% ascorbic acid and coated with a protein-based coating containing selected spices. Samples were irradiated at 0, 1, 2, and 3 kGy final dose at the CIC. Samples were stored at 4°C and evaluated periodically for microbial growth, total thiobarbituric reactive substances (TBARS) and free sulfydryl content. At the end of the storage period, Enterobacteriaceae, Lactic acid bacteria, Pseudomonas and Brochothrix thermosphacta were enumerated. Regardless of the treatment group, irradiation significantly ( p⩽0.05) reduced the total aerobic plate counts (APC). Irradiation doses of 1, 2, and 3 kGy produced immediate reduction of 2, 3, and 4 log units of APCs, respectively. Also, shelf-life periods were higher for ground beef samples containing food additives. Lactic acid bacteria and Brochothrix thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. Concentration of TBARS and free sulfydryl concentrations were stabilized during post-irradiation storage for samples containing ascorbic acid and coated with the protein-based coating containing spices.

  18. Have changes to meat and poultry food safety regulation in Australia affected the prevalence of Salmonella or of salmonellosis?

    Science.gov (United States)

    Sumner, John; Raven, Geoff; Givney, Rod

    2004-04-15

    During the 1990s, there was radical change in regulation of meat and poultry hygiene in Australia, and Australian Standards were developed for each sector of the meat industry. Systems for industry/government co-regulation and company-employed meat inspection were introduced based on company HACCP programs approved and audited by the Controlling Authority. However, in the 5 years since regulatory changes took full effect, rates of salmonellosis have not decreased (surveillance and reporting systems have remained unchanged). Using statistics gathered by the National Enteric Pathogens Surveillance Scheme, an attempt was made to link Salmonella serovars isolated from meat and poultry with those causing salmonellosis. Two periods were studied, 1993/1994, before regulations were introduced, and 2000/2001, when regulations should be having an effect. For red meat, the same serovars were prominent among the top 10 isolates both before and after regulation, and there was little linkage with salmonelloses. For poultry, frequently isolated serovars differed pre- and post-regulation, however, in both periods there was some linkage between serovars isolated from poultry and those causing salmonelloses. Using published and unpublished survey data, it was concluded that there had been improvements in microbiological quality of red meat and poultry over the same timeframe as regulatory changes. That these improvements apparently have not carried through to reduced case-rates for salmonellosis may be due to numerous causes, including lack of control in the food processing, food service and home sectors. The present paper illustrates difficulties faced by governments in measuring public health outcomes of changes to food hygiene regulation.

  19. Microbiological and biochemical characteristics of ground beef as affected by gamma irradiation, food additives and edible coating film

    Energy Technology Data Exchange (ETDEWEB)

    Ouattara, B.; Giroux, M.; Yefsah, R.; Smoragiewicz, W.; Saucier, L.; Borsa, J.; Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca

    2002-03-01

    The current interest in 'minimally processed foods' has attracted the attention for combination of mild treatments to improve food safety and shelf-life extension. The present study was conducted to evaluate the combined effect of gamma irradiation and incorporation of naturally occurring antimicrobial compounds on microbial and biochemistry characteristics of ground beef. Ground beef patties (23% fat ) were purchased from a local grocery store (IGA, Laval, Que., Canada) and divided into 3 separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid, and (iii) ground beef with 0.5% ascorbic acid and coated with a protein-based coating containing selected spices. Samples were irradiated at 0, 1, 2, and 3 kGy final dose at the CIC. Samples were stored at 4 deg. C and evaluated periodically for microbial growth, total thiobarbituric reactive substances (TBARS) and free sulfydryl content. At the end of the storage period, Enterobacteriaceae, Lactic acid bacteria, Pseudomonas and Brochothrix thermosphacta were enumerated. Regardless of the treatment group, irradiation significantly (p{<=}0.05) reduced the total aerobic plate counts (APC). Irradiation doses of 1, 2, and 3 kGy produced immediate reduction of 2, 3, and 4 log units of APCs, respectively. Also, shelf-life periods were higher for ground beef samples containing food additives. Lactic acid bacteria and Brochothrix thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. Concentration of TBARS and free sulfydryl concentrations were stabilized during post-irradiation storage for samples containing ascorbic acid and coated with the protein-based coating containing spices.

  20. The use of immunostimulants in fish larval aquaculture.

    Science.gov (United States)

    Bricknell, Ian; Dalmo, Roy A

    2005-11-01

    The production of fish larvae is often hampered by high mortality rates, and it is believed that most of this economic loss due to infectious diseases is ca. 10% in Western European aquaculture sector. The development of strategies to control the pathogen load and immuno-prophylactic measures must be addressed further to realise the economic "potential" production of marine fish larvae and thus improve the overall production of adult fish. The innate defence includes both humoral and cellular defence mechanisms such as the complement system and the processes played by granulocytes and macrophages. A set of different substances such as beta-glucans, bacterial products, and plant constituents may directly initiate activation of the innate defence mechanisms acting on receptors and triggering intracellular gene activation that may result in production of anti-microbial molecules. These immunostimulants are often obtained from bacterial sources, brown or red algae and terrestrial fungi are also exploited as source of novel potentiating substances. The use of immunostimulants, as dietary supplements, can improve the innate defence of animals providing resistance to pathogens during periods of high stress, such as grading, reproduction, sea transfer and vaccination. The immunomodulation of larval fish has been proposed as a potential method for improving larval survival by increasing the innate responses of the developing animals until its adaptive immune response is sufficiently developed to mount an effective response to the pathogen. To this end it has been proposed that the delivery of immunostimulants as a dietary supplement to larval fish could be of considerable benefit in boosting the animals innate defences with little detriment to the developing animal. Conversely, there is a school of thought that raises the concern of immunomodulating a neotanous animal before its immune system is fully formed as this may adversely affect the development of a normal immune

  1. Do differences in food web structure between organic and conventional farms affect the ecosystem service of pest control?

    Science.gov (United States)

    Macfadyen, Sarina; Gibson, Rachel; Polaszek, Andrew; Morris, Rebecca J; Craze, Paul G; Planqué, Robert; Symondson, William O C; Memmott, Jane

    2009-03-01

    While many studies have demonstrated that organic farms support greater levels of biodiversity, it is not known whether this translates into better provision of ecosystem services. Here we use a food-web approach to analyse the community structure and function at the whole-farm scale. Quantitative food webs from 10 replicate pairs of organic and conventional farms showed that organic farms have significantly more species at three trophic levels (plant, herbivore and parasitoid) and significantly different network structure. Herbivores on organic farms were attacked by more parasitoid species on organic farms than on conventional farms. However, differences in network structure did not translate into differences in robustness to simulated species loss and we found no difference in percentage parasitism (natural pest control) across a variety of host species. Furthermore, a manipulative field experiment demonstrated that the higher species richness of parasitoids on the organic farms did not increase mortality of a novel herbivore used to bioassay ecosystem service. The explanation for these differences is likely to include inherent differences in management strategies and landscape structure between the two farming systems.

  2. Cannibalistic feeding of larval Trichogramma carverae parasitoids in moth eggs

    Science.gov (United States)

    Heslin, Leeane M.; Merritt, David J.

    2005-09-01

    Wasps of the genus Trichogramma parasitise the eggs of Lepidoptera. They may deposit one or many eggs in each host. Survival is high at low density but reaches a plateau as density increases. To reveal the mechanism by which excess larvae die we chose a lepidopteran host that has flattened, transparent eggs and used video microscopy to record novel feeding behaviours and interactions of larval Trichogramma carverae (Oatman and Pinto) at different densities. Single larvae show a rapid food ingestion phase, followed by a period of extensive saliva release. Ultimately the host egg is completely consumed. The larva then extracts excess moisture from the egg, providing a dry environment for pupation. When multiple larvae are present, the initial scramble for food results in the larvae consuming all of the egg contents early in development. All larvae survive if there is sufficient food for all to reach a threshold developmental stage. If not, physical proximity results in attack and consumption of others, continuing until the surviving larvae reach the threshold stage beyond which attacks seem to be no longer effective. The number of larvae remaining at the end of rapid ingestion dictates how many will survive to emerge as adults.

  3. Does introduction of clover in an agricultural grassland affect the food base and functional diversity of Collembola?

    NARCIS (Netherlands)

    Annibale, D' Alessandra; Sechi, Valentina; Larsen, Thomas; Christensen, Søren; Krogh, Paul Henning; Eriksen, Jørgen

    2017-01-01

    Introduction of legumes (i.e. white clover) in agricultural grasslands is a common practice to improve yields, but how this affects soil fauna populations, particularly mesofauna, is still poorly understood. We investigated taxonomical and functional differences of Collembola communities between

  4. Digital game-based learning (DGBL) in the L2 classroom: The impact of the UN's off-the-shelf videogame, Food Force, on learner affect and vocabulary retention

    National Research Council Canada - National Science Library

    Claire Ikumi Hitosugi; Matthew Schmidt; Kentaro Hayashi

    2014-01-01

      This mixed-method study explored the impact of Food Force (FF), a UN-sponsored off-the-shelf videogame, on learner affect and vocabulary learning and retention in a Japanese as a second/foreign language classroom...

  5. Acondicionamiento de reproductores, desove y cultivo larval de Graus nigra (Philippi, 1887 (Kyphosidae: Girellinae Broodstock conditioning, spawning and larval culture of Graus nigra (Philippi, 1887 (Kyphosidae: Girellinae

    Directory of Open Access Journals (Sweden)

    Avelino Muñoz

    2012-09-01

    th post hatching (PE reached a total length of 12.6 ± 0.37 mm. The larval survival after hatching was between 50.9-79.1%, and at day 30 PE it was 12.1%. Larval culture was developed in tanks supplied with filtered and sterilized seawater. After yolk sac reabsorption the digestive tract development occurs and larvae were fed with live foods enriched with highly unsaturated fatty acids emulsions. Then, at day 35th larvae were offered with artificial food with size progressively greater as ontogenetic development progressed. Anatomical evolution of larvae and morphometric relationships depicting its development is described. Larval growth pattern up to 50 days post-hatching is characterized. Aspects related to larval survival and the introduction of improvements optimizing larvae and juvenile production of this species are discussed.

  6. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments.

  7. A review of postfeeding larval dispersal in blowflies: implications for forensic entomology

    Science.gov (United States)

    Gomes, Leonardo; Godoy, Wesley Augusto Conde; von Zuben, Claudio José

    2006-05-01

    Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.

  8. Effect of leaf type and pesticide exposure on abundance of bacterial taxa in mosquito larval habitats.

    Directory of Open Access Journals (Sweden)

    Ephantus J Muturi

    Full Text Available Lentic freshwater systems including those inhabited by aquatic stages of mosquitoes derive most of their carbon inputs from terrestrial organic matter mainly leaf litter. The leaf litter is colonized by microbial communities that provide the resource base for mosquito larvae. While the microbial biomass associated with different leaf species in container aquatic habitats is well documented, the taxonomic composition of these microbes and their response to common environmental stressors is poorly understood. We used indoor aquatic microcosms to determine the abundances of major taxonomic groups of bacteria in leaf litters from seven plant species and their responses to low concentrations of four pesticides with different modes of action on the target organisms; permethrin, malathion, atrazine and glyphosate. We tested the hypotheses that leaf species support different quantities of major taxonomic groups of bacteria and that exposure to pesticides at environmentally relevant concentrations alters bacterial abundance and community structure in mosquito larval habitats. We found support for both hypotheses suggesting that leaf litter identity and chemical contamination may alter the quality and quantity of mosquito food base (microbial communities in larval habitats. The effect of pesticides on microbial communities varied significantly among leaf types, suggesting that the impact of pesticides on natural microbial communities may be highly complex and difficult to predict. Collectively, these findings demonstrate the potential for detritus composition within mosquito larval habitats and exposure to pesticides to influence the quality of mosquito larval habitats.

  9. Mosquito population regulation and larval source management in heterogeneous environments.

    Directory of Open Access Journals (Sweden)

    David L Smith

    Full Text Available An important question for mosquito population dynamics, mosquito-borne pathogen transmission and vector control is how mosquito populations are regulated. Here we develop simple models with heterogeneity in egg laying patterns and in the responses of larval populations to crowding in aquatic habitats. We use the models to evaluate how such heterogeneity affects mosquito population regulation and the effects of larval source management (LSM. We revisit the notion of a carrying capacity and show how heterogeneity changes our understanding of density dependence and the outcome of LSM. Crowding in and productivity of aquatic habitats is highly uneven unless egg-laying distributions are fine-tuned to match the distribution of habitats' carrying capacities. LSM reduces mosquito population density linearly with coverage if adult mosquitoes avoid laying eggs in treated habitats, but quadratically if eggs are laid in treated habitats and the effort is therefore wasted (i.e., treating 50% of habitat reduces mosquito density by approximately 75%. Unsurprisingly, targeting (i.e. treating a subset of the most productive pools gives much larger reductions for similar coverage, but with poor targeting, increasing coverage could increase adult mosquito population densities if eggs are laid in higher capacity habitats. Our analysis suggests that, in some contexts, LSM models that accounts for heterogeneity in production of adult mosquitoes provide theoretical support for pursuing mosquito-borne disease prevention through strategic and repeated application of modern larvicides.

  10. Nesfatin-130−59 Injected Intracerebroventricularly Differentially Affects Food Intake Microstructure in Rats Under Normal Weight and Diet-Induced Obese Conditions

    Science.gov (United States)

    Prinz, Philip; Teuffel, Pauline; Lembke, Vanessa; Kobelt, Peter; Goebel-Stengel, Miriam; Hofmann, Tobias; Rose, Matthias; Klapp, Burghard F.; Stengel, Andreas

    2015-01-01

    Nesfatin-1 is well-established to induce an anorexigenic effect. Recently, nesfatin-130−59, was identified as active core of full length nesfatin-11−82 in mice, while its role in rats remains unclear. Therefore, we investigated the effects of nesfatin-130−59 injected intracerebroventricularly (icv) on the food intake microstructure in rats. To assess whether the effect was also mediated peripherally we injected nesfatin-130−59 intraperitoneally (ip). Since obesity affects the signaling of various food intake-regulatory peptides we investigated the effects of nesfatin-130−59 under conditions of diet-induced obesity (DIO). Male Sprague–Dawley rats fed ad libitum with standard diet were icv cannulated and injected with vehicle (5 μl ddH2O) or nesfatin-130−59 at 0.37, 1.1, and 3.3 μg (0.1, 0.3, 0.9 nmol/rat) and the food intake microstructure assessed using a food intake monitoring system. Next, naïve rats were injected ip with vehicle (300 μl saline) or nesfatin-130−59 (8.1, 24.3, 72.9 nmol/kg). Lastly, rats were fed a high fat diet for 10 weeks and those developing DIO were icv cannulated. Nesfatin-1 (0.9 nmol/rat) or vehicle (5 μl ddH2O) was injected icv and the food intake microstructure assessed. In rats fed standard diet, nesfatin-130−59 caused a dose-dependent reduction of dark phase food intake reaching significance at 0.9 nmol/rat in the period of 4–8 h post injection (−29%) with the strongest reduction during the fifth hour (−75%), an effect detectable for 24 h (−12%, p < 0.05 vs. vehicle). The anorexigenic effect of nesfatin-130−59 was due to a reduction in meal size (−44%, p < 0.05), while meal frequency was not altered compared to vehicle. In contrast to icv injection, nesfatin-130−59 injected ip in up to 30-fold higher doses did not alter food intake. In DIO rats fed high fat diet, nesfatin-130−59 injected icv reduced food intake in the third hour post injection (−71%), an effect due to a reduced meal frequency (

  11. Nesfatin-1(30-59 injected intracerebroventricularly differentially affects food intake microstructure in rats under normal weight and diet-induced obese conditions

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    Philip ePrinz

    2015-11-01

    Full Text Available Nesfatin-1 is well established to induce an anorexigenic effect. Recently, nesfatin-1(30-59, was identified as active core of full length nesfatin-1(1-82 in mice, while its role in rats remains unclear. Therefore, we investigated the effects of nesfatin-1(30-59 injected intracerebroventricularly (icv on the food intake microstructure in rats. To assess whether the effect was also mediated peripherally we injected nesfatin-1(30-59 intraperitoneally (ip. Since obesity affects the signaling of various food intake-regulatory peptides we investigated the effects of nesfatin-1(30-59 under conditions of diet-induced obesity (DIO. Male Sprague-Dawley rats fed ad libitum with standard diet were icv cannulated and injected with vehicle (5µl ddH2O or nesfatin-1(30-59 at 0.37, 1.1 and 3.3 µg (0.1, 0.3, 0.9 nmol/rat and the food intake microstructure assessed using a food intake monitoring system. Next, naïve rats were injected ip with vehicle (300 µl saline or nesfatin-1(30-59 (8.1, 24.3, 72.9 nmol/kg. Lastly, rats were fed a high fat diet for 10 weeks and those developing DIO were icv cannulated. Nesfatin-1 (0.9 nmol/rat or vehicle (5µl ddH2O was injected icv and the food intake microstructure assessed. In rats fed standard diet, nesfatin-1(30-59 caused a dose-dependent reduction of dark phase food intake reaching significance at 0.9 nmol/rat in the period of 4-8 h post injection (-29% with the strongest reduction during the 5th h (-75%, an effect detectable for 24 h (-12%, p<0.05 vs. vehicle. The anorexigenic effect of nesfatin-130-59 was due to a reduction in meal size (-44%, p<0.05, while meal frequency was not altered compared to vehicle. In contrast to icv injection, nesfatin-1(30-59 injected ip in up to 30-fold higher doses did not alter food intake. In DIO rats fed high fat diet, nesfatin-1(30-59 injected icv reduced food intake in the 3rd h post injection (-71%, an effect due to a reduced meal frequency (-27%, p<0.05, while meal size was not

  12. Cell cycle analysis of brain cells as a growth index in larval cod at different feeding conditions and temperatures

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    Rafael González-Quirós

    2007-09-01

    Full Text Available The percentage of cells dividing in a specific tissue of individual larvae can be estimated by analyzing DNA per cell by flow cytometry. An experimental test was carried out with cod (Gadus morhua larvae, with brain as the target tissue, to validate this technique as an appropriate growth index for larval fish. Standard length (SL, myotome height, and %S-phase (% of cells in the S-phase of the cell-division cycle variability were analyzed, with temperature (6 and 10°C, food level (high- and no-food and larval developmental stage (first feeding, pre-metamorphosis and post-metamorphosis as independent factors. Cod larvae grew faster (in SL and presented a higher %S-phase under high-food conditions. Larval SL increased with temperature in rearing and experimental tanks. However, there was a significant interaction between temperature and food in the %S-phase. There were no significant differences in the %S-phase between 6 and 10°C at high-food levels. We suggest that this result is a consequence of temperature-dependency of the duration of the cell cycle. In the absence of food, larvae at 10ºC had a lower %S-phase than larvae at 6°C, which may be related to increased metabolic costs with increasing temperature. Considering the effect of temperature, the mean % S-phase explained 74% of the variability in the estimated standard growth rate.

  13. Effect of tanniniferous food from Bauhinia pulchella on pasture contamination with gastrointestinal nematodes from goats.

    Science.gov (United States)

    Lopes, Suzana G; Barros, Lilyan B G; Louvandini, Helder; Abdalla, Adibe L; Costa Junior, Livio M

    2016-02-24

    Tannin-rich plants have been examined as an alternative for controlling the gastrointestinal nematodes in ruminants. In vivo assays typically examine the anthelmintic activity in female fecundity and/or the adult worm burden, without considering other life-cycle stages or the impact on pasture contamination. The aim of the present study was to evaluate the anthelmintic activity of tanniniferous food from Bauhinia pulchella in goats and the potential impact on pasture contamination with the infective larval stage of gastrointestinal nematodes. Sixteen cross breed Boer goats that were naturally infected with gastrointestinal nematodes were fed tanniniferous concentrate from the leaves of B. pulchella and compared to a separate paddock of control animals without condensed tannin supplementation. A range of parasite characteristics were monitored throughout the 63 days of experimentation, including faecal egg count (FEC), egg hatching and relative numbers of hatched helminth larvae on herbage. Worm free tracer animals were used to assess the infective larval stage load of the contaminated pasture. The tanniniferous food did not reduce the combined FEC values, but egg hatching was significantly affected (p < 0.05). The pasture grazed by goats fed with tanniniferous food from B. pulchella showed reduced contamination through infective larval stages. Tracer goats maintained in paddocks grazed with animals fed with tanniniferous food had lower numbers of Trichostrongylus colubriformis than did those in the control group (86 % reduction). Condensed tannin from B. pulchella showed anthelmintic activity, affected egg viability and reduced pasture contamination, which led to the reduced infection of the animals by T. colubriformis.

  14. Selective serotonin receptor stimulation of the medial nucleus accumbens differentially affects appetitive motivation for food on a progressive ratio schedule of reinforcement.

    Science.gov (United States)

    Pratt, Wayne E; Schall, Megan A; Choi, Eugene

    2012-03-09

    Previously, we reported that stimulation of selective serotonin (5-HT) receptor subtypes in the nucleus accumbens shell differentially affected consumption of freely available food. Specifically, activation of 5-HT(6) receptors caused a dose-dependent increase in food intake, while the stimulation of 5-HT(1/7) receptor subtypes decreased feeding [34]. The current experiments tested whether similar pharmacological activation of nucleus accumbens serotonin receptors would also affect appetitive motivation, as measured by the amount of effort non-deprived rats exerted to earn sugar reinforcement. Rats were trained to lever press for sugar pellets on a progressive ratio 2 schedule of reinforcement. Across multiple treatment days, three separate groups (N=8-10) received bilateral infusions of the 5-HT(6) agonist EMD 386088 (at 0.0, 1.0 and 4.0 μg/0.5 μl/side), the 5-HT(1/7) agonist 5-CT (at 0, 0.5, 1.0, or 4.0 μg/0.5 μl/side), or the 5-HT(2C) agonist RO 60-0175 fumarate (at 0, 2.0, or 5.0 μg/0.5 μl/side) into the anterior medial nucleus accumbens prior to a 1-h progressive ratio session. Stimulation of 5-HT(6) receptors caused a dose-dependent increase in motivation as assessed by break point, reinforcers earned, and total active lever presses. Stimulation of 5-HT(1/7) receptors increased lever pressing at the 0.5 μg dose of 5-CT, but inhibited lever presses and break point at 4.0 μg/side. Injection of the 5-HT(2C) agonist had no effect on motivation within the task. Collectively, these experiments suggest that, in addition to their role in modulating food consumption, nucleus accumbens 5-HT(6) and 5-HT(1/7) receptors also differentially regulate the appetitive components of food-directed motivation.

  15. Temperature- and sex-related effects of serine protease alleles on larval development in the Glanville fritillary butterfly.

    Science.gov (United States)

    Ahola, V; Koskinen, P; Wong, S C; Kvist, J; Paulin, L; Auvinen, P; Saastamoinen, M; Frilander, M J; Lehtonen, R; Hanski, I

    2015-12-01

    The body reserves of adult Lepidoptera are accumulated during larval development. In the Glanville fritillary butterfly, larger body size increases female fecundity, but in males fast larval development and early eclosion, rather than large body size, increase mating success and hence fitness. Larval growth rate is highly heritable, but genetic variation associated with larval development is largely unknown. By comparing the Glanville fritillary population living in the Åland Islands in northern Europe with a population in Nantaizi in China, within the source of the post-glacial range expansion, we identified candidate genes with reduced variation in Åland, potentially affected by selection under cooler climatic conditions than in Nantaizi. We conducted an association study of larval growth traits by genotyping the extremes of phenotypic trait distributions for 23 SNPs in 10 genes. Three genes in clip-domain serine protease family were associated with larval growth rate, development time and pupal weight. Additive effects of two SNPs in the prophenoloxidase-activating proteinase-3 (ProPO3) gene, related to melanization, showed elevated growth rate in high temperature but reduced growth rate in moderate temperature. The allelic effects of the vitellin-degrading protease precursor gene on development time were opposite in the two sexes, one genotype being associated with long development time and heavy larvae in females but short development time in males. Sexually antagonistic selection is here evident in spite of sexual size dimorphism.

  16. Larval development of Evermannia zosterura (Perciformes: Gobiidae)

    OpenAIRE

    González-Navarro, Enrique; Saldierna-Martínez, Ricardo Javier; Aceves-Medina, Gerardo

    2013-01-01

    Gobiidae is the most specious fish family in the world with almost 2 000 species, however only 11% of them have been described for their larval stages. The entire life cycle information is essential to understand the biology and ecology of this important fish group. Previous studies on zooplankton samples from Ensenada de La Paz, México, have shown the presence of several Gobiidae larvae and juveniles which were identified as Evermania zosterura. The main objective of this work was to describ...

  17. Depletion of Essential Fatty Acids in the Food Source Affects Aerobic Capacities of the Golden Grey Mullet Liza aurata in a Warming Seawater Context.

    Science.gov (United States)

    Vagner, Marie; Lacoue-Labarthe, Thomas; Zambonino Infante, José-Luis; Mazurais, David; Dubillot, Emmanuel; Le Delliou, Hervé; Quazuguel, Patrick; Lefrançois, Christel

    2015-01-01

    The objective of this study was to evaluate the combined effects of thermal acclimation and n-3 highly unsaturated fatty acids (n-3 HUFA) content of the food source on the aerobic capacities of fish in a thermal changing environment. The model used was the golden grey mullet Liza aurata, a species of high ecological importance in temperate coastal areas. For four months, fish were exposed to two food sources with contrasting n-3 HUFA contents (4.8% ecosapentaenoic acid EPA + docosahexaenoic acid DHA on the dry matter DM basis vs. 0.2% EPA+DHA on DM) combined with two acclimation temperatures (12°C vs. 20°C). The four experimental conditions were LH12, LH20, HH12 and HH20. Each group was then submitted to a thermal challenge consisting of successive exposures to five temperatures (9°C, 12°C, 16°C, 20°C, 24°C). At each temperature, the maximal and minimal metabolic rates, metabolic scope, and the maximum swimming speed were measured. Results showed that the cost of maintenance of basal metabolic activities was particularly higher when n-3 HUFA food content was low. Moreover, fish exposed to high acclimation temperature combined with a low n-3 HUFA dietary level (LH20) exhibited a higher aerobic scope, as well as a greater expenditure of energy to reach the same maximum swimming speed as other groups. This suggested a reduction of the amount of energy available to perform other physiological functions. This study is the first to show that the impact of lowering n-3 HUFA food content is exacerbated for fish previously acclimated to a warmer environment. It raises the question of the consequences of longer and warmer summers that have already been recorded and are still expected in temperate areas, as well as the pertinence of the lowering n-3 HUFA availability in the food web expected with global change, as a factor affecting marine organisms and communities.

  18. Depletion of Essential Fatty Acids in the Food Source Affects Aerobic Capacities of the Golden Grey Mullet Liza aurata in a Warming Seawater Context.

    Directory of Open Access Journals (Sweden)

    Marie Vagner

    Full Text Available The objective of this study was to evaluate the combined effects of thermal acclimation and n-3 highly unsaturated fatty acids (n-3 HUFA content of the food source on the aerobic capacities of fish in a thermal changing environment. The model used was the golden grey mullet Liza aurata, a species of high ecological importance in temperate coastal areas. For four months, fish were exposed to two food sources with contrasting n-3 HUFA contents (4.8% ecosapentaenoic acid EPA + docosahexaenoic acid DHA on the dry matter DM basis vs. 0.2% EPA+DHA on DM combined with two acclimation temperatures (12°C vs. 20°C. The four experimental conditions were LH12, LH20, HH12 and HH20. Each group was then submitted to a thermal challenge consisting of successive exposures to five temperatures (9°C, 12°C, 16°C, 20°C, 24°C. At each temperature, the maximal and minimal metabolic rates, metabolic scope, and the maximum swimming speed were measured. Results showed that the cost of maintenance of basal metabolic activities was particularly higher when n-3 HUFA food content was low. Moreover, fish exposed to high acclimation temperature combined with a low n-3 HUFA dietary level (LH20 exhibited a higher aerobic scope, as well as a greater expenditure of energy to reach the same maximum swimming speed as other groups. This suggested a reduction of the amount of energy available to perform other physiological functions. This study is the first to show that the impact of lowering n-3 HUFA food content is exacerbated for fish previously acclimated to a warmer environment. It raises the question of the consequences of longer and warmer summers that have already been recorded and are still expected in temperate areas, as well as the pertinence of the lowering n-3 HUFA availability in the food web expected with global change, as a factor affecting marine organisms and communities.

  19. Activity patterns during food provisioning are affected by artificial light in free living great tits (Parus major.

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    Mieke Titulaer

    Full Text Available Artificial light may have severe ecological consequences but there is limited experimental work to assess these consequences. We carried out an experimental study on a wild population of great tits (Parus major to assess the impact of light pollution on daily activity patterns during the chick provisioning period. Pairs that were provided with a small light outside their nest box did not alter the onset, cessation or duration of their working day. There was however a clear effect of artificial light on the feeding rate in the second half of the nestling period: when provided with artificial light females increased their feeding rate when the nestlings were between 9 and 16 days old. Artificial light is hypothesised to have affected the perceived photoperiod of either the parents or the offspring which in turn led to increased parental care. This may have negative fitness consequences for the parents, and light pollution may thus create an ecological trap for breeding birds.

  20. Acute central neuropeptide Y administration increases food intake but does not affect hepatic very low-density lipoprotein (VLDL production in mice.

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    Janine J Geerling

    Full Text Available OBJECTIVE: Central neuropeptide Y (NPY administration stimulates food intake in rodents. In addition, acute modulation of central NPY signaling increases hepatic production of very low-density lipoprotein (VLDL-triglyceride (TG in rats. As hypertriglyceridemia is an important risk factor for atherosclerosis, for which well-established mouse models are available, we set out to validate the effect of NPY on hepatic VLDL-TG production in mice, to ultimately investigate whether NPY, by increasing VLDL production, contributes to the development of atherosclerosis. RESEARCH DESIGN AND METHODS: Male C57Bl/6J mice received an intracerebroventricular (i.c.v. cannula into the lateral (LV or third (3V ventricle of the brain. One week later, after a 4 h fast, the animals received an intravenous (i.v. injection of Tran(35S (100 µCi followed by tyloxapol (500 mg/kg body weight; BW, enabling the study of hepatic VLDL-apoB and VLDL-TG production, respectively. Immediately after the i.v. injection of tyloxapol, the animals received either an i.c.v. injection of NPY (0.2 mg/kg BW in artificial cerebrospinal fluid; aCSF, synthetic Y1 receptor antagonist GR231118 (0.5 mg/kg BW in aCSF or vehicle (aCSF, or an i.v. injection of PYY3-36 (0.5 mg/kg BW in PBS or vehicle (PBS. RESULTS: Administration of NPY into both the LV and 3V increased food intake within one hour after injection (+164%, p<0.001 and +367%, p<0.001, respectively. NPY administration neither in the LV nor in the 3V affected hepatic VLDL-TG or VLDL-apoB production. Likewise, antagonizing central NPY signaling by either PYY3-36 or GR231118 administration did not affect hepatic VLDL production. CONCLUSION: In mice, as opposed to rats, acute central administration of NPY increases food intake without affecting hepatic VLDL production. These results are of great significance when extrapolating findings on the central regulation of hepatic VLDL production between species.

  1. Growth variability and stable isotope composition of two larval carangid fishes in the East Australian Current: The role of upwelling in the separation zone

    Science.gov (United States)

    Syahailatua, Augy; Taylor, Matthew D.; Suthers, Iain M.

    2011-03-01

    The larvae of two carangid fishes, silver trevally ( Pseudocaranx dentex) and yellowtail scad ( Trachurus novaezelandiae), were compared among coastal water masses and the East Australian Current (EAC). Samples followed a north to south gradient including a southern region of upwelling, generated as the EAC separated from the coast. Mean larval carangid densities were greater in the mixed layer (10-30 m) than the surface, but there was no difference between inshore and offshore stations or along latitudinal gradients. Overall, P. dentex recent larval growth over two days pre-capture was faster than T. novaezelandiae, and faster at inshore, coastal stations than in the EAC. Integrated larval growth rate (mm d -1) was usually faster at inshore stations for both species. T. novaezelandiae were enriched in both nitrogen (δ 15N) and carbon (δ 13C) stable isotopes relative to P. dentex. Larvae of both species captured within the upwelling region were enriched in δ 15N and depleted in δ 13C relative to other sites. Recent larval growth had a significant positive relationship with fluorescence (as a proxy of chlorophyll a biomass), and integrated larval growth rate had a significant positive relationship with fluorescence and larval isotope (δ 15N) composition. Recent and integrated growth of larval T. novaezelandiae and P. dentex was enhanced by EAC separation and upwelling, and also in coastal water; stimulated by food availability, and potentially through exploitation of a different trophic niche.

  2. Lake size and water-column stability affect the importance of methane for pelagic food webs of boreal lakes

    Science.gov (United States)

    Kankaala, Paula; Lopez-Bellido, Jessica; Ojala, Anne; Tulonen, Tiina; Jones, Roger I.

    2013-04-01

    Physical forcing, related to lake size and morphometry, plays an important role in the landscape-scale biogeochemical processing and fluxes of terrestrial carbon in lakes. Boreal lakes are typically dimictic, with mixing of the water column in spring and autumn, but in small, sheltered, humic, forest lakes the spring mixing is often incomplete. This leads to a steep summer stratification and oxygen depletion in the hypolimnion of the lakes. As a result of anaerobic decomposition of organic matter, high concentrations of CH4are typical in these lakes. At the oxic-anoxic interface zone methanotrophic microbes oxidize CH4 to CO2 and partly incorporate CH4-C into microbial biomass, and thus potentially provide a diet source for pelagic consumers. We studied production at the base of the pelagic food web by methane oxidising bacteria (MOB), heterotrophic bacteria (HB) and phytoplankton (PP) in five boreal lakes with a dissolved organic carbon (DOC) concentration varying between 7 and 25 mg C L-1 and an area ranging from 0.004 to 13.4 km2. High MOB activity was detected in the water columns of the three smallest lakes having anoxia in the hypolimnion during summer. The highest MOB activities (ca. 2-12 μmol L-1 d-1) were observed when the CH4:O2 ratio varied between ca. 0.5-12. Seasonally, the highest MOB activities were measured during late-summer mixed layer deepening and autumnal mixing of the whole water column. The proportion of MOB in the total basal production was highest in the two smallest lakes (24-56 and 13-36%), having the steepest summertime stratification. The proportion MOB in the basal production decreased with lake size being 70% of basal production was by PP. In all studied lakes HB contributed only 10-23% of the total basal production, suggesting that a transfer of allochthonous DOC via HB plays only a modest role for the nutrition of the higher trophic levels.

  3. Chronic treatment with long-acting bromocriptine does not affect duration of the breeding season, voluntary food intake, body weight, or wool growth in the Scottish blackface ewe.

    Science.gov (United States)

    Curlewis, J D; Sibbald, A M; Milne, J A; McNeilly, A S

    1991-01-01

    The aim of this study was to determine whether suppression of the seasonal increase in prolactin concentrations by chronic treatment with the dopamine agonist bromocriptine would affect onset of anoestrus, voluntary food intake, body weight, and wool growth in a seasonal breed of sheep. Groups of eight Scottish Blackface ewes were injected i.m. each week with either the vehicle (Group A) or 2.0 mg (Group B), 6.0 mg (Group C), or 18.0 mg (Group D) of bromocriptine in a long-acting formulation, commencing on 18 January and terminating on 25 July (midwinter to midsummer in the northern hemisphere). Immediately before the bromocriptine injection, blood samples were taken for progesterone and prolactin determination. Voluntary food intakes were measured daily, and body weights were recorded every fortnight. Estimates of wool growth were made by weighing wool clipped from a measured area of skin once a month. Treatment had no effect on onset of anoestrus, voluntary food intake, body weight, or wool growth. Plasma prolactin concentrations increased significantly in all groups during the treatment period. From January to April, all doses of bromocriptine significantly reduced prolactin concentrations but later in the study (May and June) prolactin was significantly suppressed in Group D only, although even in this group prolactin concentrations increased between March and June. Pituitary prolactin content, measured at the end of the study in July, was also suppressed by bromocriptine. The gradual increase in prolactin concentrations in ewes receiving chronic bromocriptine was further investigated by treating a fifth group of ewes (Group E) with 18.0 mg of long-acting bromocriptine each week, commencing on 20 June.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. p53-upregulated-modulator-of-apoptosis (PUMA) deficiency affects food intake but does not impact on body weight or glucose homeostasis in diet-induced obesity.

    Science.gov (United States)

    Litwak, Sara A; Loh, Kim; Stanley, William J; Pappas, Evan G; Wali, Jibran A; Selck, Claudia; Strasser, Andreas; Thomas, Helen E; Gurzov, Esteban N

    2016-04-01

    BCL-2 proteins have been implicated in the control of glucose homeostasis and metabolism in different cell types. Thus, the aim of this study was to determine the role of the pro-apoptotic BH3-only protein, p53-upregulated-modulator-of-apoptosis (PUMA), in metabolic changes mediated by diet-induced obesity, using PUMA deficient mice. At 10 weeks of age, knockout and wild type mice either continued consuming a low fat chow diet (6% fat), or were fed with a high fat diet (23% fat) for 14-17 weeks. We measured body composition, glucose and insulin tolerance, insulin response in peripheral tissues, energy expenditure, oxygen consumption, and respiratory exchange ratio in vivo. All these parameters were indistinguishable between wild type and knockout mice on chow diet and were modified equally by diet-induced obesity. Interestingly, we observed decreased food intake and ambulatory capacity of PUMA knockout mice on high fat diet. This was associated with increased adipocyte size and fasted leptin concentration in the blood. Our findings suggest that although PUMA is dispensable for glucose homeostasis in lean and obese mice, it can affect leptin levels and food intake during obesity.

  5. Comparison of probabilistic and deterministic predictions of time to growth of Listeria monocytogenes as affected by pH and temperature in food.

    Science.gov (United States)

    Guevara, Leymaya; Martínez, Antonio; Fernández, Pablo S; Muñoz-Cuevas, Marina

    2011-01-01

    Stochastic models are useful for estimating the risk of foodborne illness and they can be integrated, besides other sources of variability, into microbial risk assessment. A stochastic approach to evaluate growth of two strains of Listeria monocytogenes influenced by different factors affecting microbial growth (pH and storage temperature) was performed. An individual-based approach of growth through optical density measurements was used. From results obtained, histograms of the lag phase were generated and distributions were fitted. Histograms presented increased variation when the factors applied were suboptimal for L. monocytogenes and they were combined. The extreme value distribution was ranked as the best one in most cases, whereas normal was the poorest fitting distribution. To evaluate the influence of pH and storage temperature on L. monocytogenes CECT 5672 in real food, commercial samples of courgette and carrot soup were inoculated with this pathogen. It was able to grow in both soups at storage temperatures from 4°C to 20°C. Using the distributions adjusted, predictions of time to growth (10² cfu/g) of L. monocytogenes were established by Monte Carlo simulation and they were compared with deterministic predictions and observations in foods.

  6. Global mismatch between fishing dependency and larval supply from marine reserves

    Science.gov (United States)

    Andrello, Marco; Guilhaumon, François; Albouy, Camille; Parravicini, Valeriano; Scholtens, Joeri; Verley, Philippe; Barange, Manuel; Sumaila, U. Rashid; Manel, Stéphanie; Mouillot, David

    2017-07-01

    Marine reserves are viewed as flagship tools to protect exploited species and to contribute to the effective management of coastal fisheries. Yet, the extent to which marine reserves are globally interconnected and able to effectively seed areas, where fisheries are most critical for food and livelihood security is largely unknown. Using a hydrodynamic model of larval dispersal, we predict that most marine reserves are not interconnected by currents and that their potential benefits to fishing areas are presently limited, since countries with high dependency on coastal fisheries receive very little larval supply from marine reserves. This global mismatch could be reversed, however, by placing new marine reserves in areas sufficiently remote to minimize social and economic costs but sufficiently connected through sea currents to seed the most exploited fisheries and endangered ecosystems.

  7. Comparison of alpha-amylase activity in larval stages of flour beetles, Tribolium confusum (Coleoptera: Tenebionidae).

    Science.gov (United States)

    Bandani, A R; Balvasi, A

    2006-01-01

    Flour beetles attack stored grain products such as flour, cereals, meal, dried pet food, dried flowers and even dried museum specimens and other foods in the house. Stored-product insects cause tremendous losses by lowering weight, germination rate, nutritional value and grain grade. These beetles are of the most important pests of stored products in the home and grocery stores. The adult female may live for as long as two years, depositing 300 to 400 eggs. The life cycle requires one to four months when temperatures are favorable. Several methods could be used to control this insect including synthetic insecticides, biological control, physical control and transgenic plant carrying gene of interest. Chemical controls are discouraged due to pesticide residue in the commodities and resistance in insects. The study of insect digestive enzymes seems to make sense in the realization that the gut is the major interface between the insect and its environment. Hence, an understanding of digestive enzyme function is essential when developing methods of insect control such as the use of enzyme inhibitors and transgenic plants to control insect pests. Therefore, the aim of the current study was to get a good understanding from enzyme composition of different larval stages of the insect and finally characterize amylase which is the key enzyme in digestive system of this insect. For alpha-amylase study whole larvae were homogenized in 0.02 M phosphate buffer at pH 7.2. The homogenates were separately transferred to a 1.5 ml of centrifuge tubes and centrifuged at 15000xg for 20 min at 4degrees C. The supernatants were used as enzyme source in assays. alpha-Amylase activity was assayed by the dinitrosalicylic acid (DNS) procedure using 1% soluble starch (Merck) as substrate. The results show that enzyme activity (OD) in the first, second, third and fourth larval stages were 0.5, 1.15, 1.35 and 1.362, respectively. There are significant differences in amylase activity in

  8. Larval Environment Alters Amphibian Immune Defenses Differentially across Life Stages and Populations.

    Directory of Open Access Journals (Sweden)

    Katherine L Krynak

    Full Text Available Recent global declines, extirpations and extinctions of wildlife caused by newly emergent diseases highlight the need to improve our knowledge of common environmental factors that affect the strength of immune defense traits. To achieve this goal, we examined the influence of acidification and shading of the larval environment on amphibian skin-associated innate immune defense traits, pre and post-metamorphosis, across two populations of American Bullfrogs (Rana catesbeiana, a species known for its wide-ranging environmental tolerance and introduced global distribution. We assessed treatment effects on 1 skin-associated microbial communities and 2 post-metamorphic antimicrobial peptide (AMP production and 3 AMP bioactivity against the fungal pathogen Batrachochytrium dendrobatidis (Bd. While habitat acidification did not affect survival, time to metamorphosis or juvenile mass, we found that a change in average pH from 7 to 6 caused a significant shift in the larval skin microbial community, an effect which disappeared after metamorphosis. Additionally, we found shifts in skin-associated microbial communities across life stages suggesting they are affected by the physiological or ecological changes associated with amphibian metamorphosis. Moreover, we found that post-metamorphic AMP production and bioactivity were significantly affected by the interactions between pH and shade treatments and interactive effects differed across populations. In contrast, there were no significant interactions between treatments on post-metamorphic microbial community structure suggesting that variation in AMPs did not affect microbial community structure within our study. Our findings indicate that commonly encountered variation in the larval environment (i.e. pond pH and degree of shading can have both immediate and long-term effects on the amphibian innate immune defense traits. Our work suggests that the susceptibility of amphibians to emerging diseases could be

  9. The effect of rearing temperature in larval development of pejerrey, Odontesthes bonariensis: morphological indicators of development

    Directory of Open Access Journals (Sweden)

    Tomás Chalde

    Full Text Available It is well known that in pejerrey water temperature not only affects growth rates but also directs the sexual differentiation process. This fact rise the question of how different the development of pejerrey larvae of the same age is when reared at different temperatures. A description of developmental stages for the embryonic and larval periods of the pejerrey, Odontesthes bonariensis, and the influence of rearing temperature on larval development are presented. Then, larval development was studied at three rearing temperatures, and changes in general morphology, fin morphology, and caudal fin structure have been taken into consideration within the thermal range involved in the temperature sex determination of this species. Fin fold reabsorption, caudal fin formation, and body shape were selected to follow the events leading to the acquisition of the juvenile morphology. The juvenile phenotype was defined when the fin fold was reabsorpted and the caudal fin acquired its definitive homocercal structure. The moment at which the juvenile phenotype was achieved, was evaluated in relation to larval age, size and, shape. The size resulted as the best indicator of development in pejerrey.

  10. Larval development and settlement of a whale barnacle.

    Science.gov (United States)

    Nogata, Yasuyuki; Matsumura, Kiyotaka

    2006-03-22

    Larval development and settlement of whale barnacles have not previously been described, unlike intertidal barnacles. Indeed, the mechanisms of the association between barnacles and whales have not been studied. Here we describe the larval development and settlement of the whale barnacle, Coronula diadema, and possible involvement of a cue from the host in inducing larval settlement. Eight-cell stage embryos were collected from C. diadema on a stranded humpback whale, incubated in filtered seawater for 7 days, and nauplius larvae hatched out. When fed with Chaetoceros gracilis, the nauplii developed to stage VI, and finally metamorphosed to the cypris stage. The larval development looked similar to that of intertidal barnacles with planktotrophic larval stages. The cyprids did not settle in normal seawater, but did settle in polystyrene Petri dishes when incubated in seawater with a small piece of skin tissue from the host whale. This strongly suggests the involvement of a chemical cue from the host whale tissue to induce larval settlement.

  11. Condition and size of damselflies: a field study of food limitation.

    Science.gov (United States)

    Baker, Robert L

    1989-10-01

    Based on evidence from field manipulations, several authors have recently suggested that interference competition among larval odonates reduces individual growth rates and biomass by reducing foraging rates. This study was designed to test the effects of food shortage on "condition" (relative mass per unit head width) of larval Ischnura verticalis (Odonata: Coenagrionidae) under laboratory conditions and to use these results to estimate the degree of food shortage of larvae under naturally occurring field conditions. In the laboratory, there were marked differences in condition of larvae fed diets ranging from ad libitum feeding with worms to ad libitum feeding with Daphnia 1 day out of every 8. Condition of larvae collected from May through October from 17 different sites in southern Ontario indicated that, for most of the year, larvae had conditions similar to those fed ad libitum with Daphnia in the laboratory. There was no evidence that larval condition was related to population density. Condition of larvae in most sites during July was similar to that of larvae fed poor diets in the laboratory. It is unlikely that the low conditions were due to competition as there were no correlations with density across sites and population densities during July were at their lowest. Adult head widths showed a seasonal decline from mid June to the end of the flight season. There was no evidence that head widths were related to population density although there was some evidence that head widths of males were positively related to larval condition. My results do not support the hypothesis that competition is important in affecting foraging rates and subsequent development of larvae. Contrasts between my results and other studies may stem from difficulties with the interpretation of field experiments, that densities in my study may have been low due to fish predation, and/or that I. verticalis larvae are slow moving relative to other larvae and thus less likely to interact.

  12. Intra-instar larval cannibalism in Anopheles gambiae (s.s.) and Anopheles stephensi (Diptera: Culicidae).

    Science.gov (United States)

    Porretta, Daniele; Mastrantonio, Valentina; Crasta, Graziano; Bellini, Romeo; Comandatore, Francesco; Rossi, Paolo; Favia, Guido; Bandi, Claudio; Urbanelli, Sandra

    2016-11-02

    Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1) has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4) of Anopheles gambiae (s.s.) and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size) on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s.) than in An. stephensi. In both species the total number of cannibalistic events increased from 0-24 to 0-48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s.) and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of

  13. Larval diapause termination in the bamboo borer, Omphisa fuscidentalis

    Science.gov (United States)

    Suang, Suphawan; Manaboon, Manaporn; Singtripop, Tippawan; Hiruma, Kiyoshi; Kaneko, Yu; Tiansawat, Pimonrat; Neumann, Peter; Chantawannakul, Panuwan

    2017-01-01

    In insects, juvenile hormone (JH) and 20-hydroxyecdysone (20E) regulate larval growth and molting. However, little is known about how this cooperative control is terminating larval diapause especially in the bamboo borer, Omphisa fuscidentalis. In both in vivo and in vitro experiments, we here measured the expression levels of genes which were affected by juvenile hormone analogue (JHA: S-methoprene) and 20-hydroxyecdysone (20E) in diapausing O. fuscidentalis larvae. Corresponding mRNA expression changes in the subesophageal ganglion (SG) and prothoracic gland (PG) were evaluated using qRT-PCR. The data showed similar response patterns of JH receptor gene (OfMet), diapause hormone gene (OfDH-PBAN), ecdysone receptor genes (OfEcR-A and OfEcR-B1) and ecdysone inducible genes (OfBr-C, OfE75A, OfE75B, OfE75C and OfHR3). JHA induced the expressions of OfMet and OfDH-PBAN in both SG and PG, whereas ecdysone receptor genes and ecdysone inducible genes were induced by JHA only in PG. For 20E treatment group, expressions of ecdysone receptor genes and ecdysone inducible genes in both SG and PG were increased by 20E injection. In addition, the in vitro experiments showed that OfMet and OfDH-PBAN were up-regulated by JHA alone, but ecdysone receptor genes and ecdysone inducible genes were up-regulated by JHA and 20E. However, OfMet and OfDH-PBAN in the SG was expressed faster than OfMet and OfDH-PBAN in the PG and the expression of ecdysone receptor genes and ecdysone inducible genes induced by JHA was much later than observed for 20E. These results indicate that JHA might stimulate the PG indirectly via factors (OfMet and OfDH-PBAN) in the SG, which might be a regulatory mechanism for larval diapause termination in O. fuscidentalis. PMID:28369111

  14. Adaptive locomotor behavior in larval zebrafish.

    Science.gov (United States)

    Portugues, Ruben; Engert, Florian

    2011-01-01

    In this study we report that larval zebrafish display adaptive locomotor output that can be driven by unexpected visual feedback. We develop a new assay that addresses visuomotor integration in restrained larval zebrafish. The assay involves a closed-loop environment in which the visual feedback a larva receives depends on its own motor output in a way that resembles freely swimming conditions. The experimenter can control the gain of this closed feedback loop, so that following a given motor output the larva experiences more or less visual feedback depending on whether the gain is high or low. We show that increases and decreases in this gain setting result in adaptive changes in behavior that lead to a generalized decrease or increase of motor output, respectively. Our behavioral analysis shows that both the duration and tail beat frequency of individual swim bouts can be modified, as well as the frequency with which bouts are elicited. These changes can be implemented rapidly, following an exposure to a new gain of just 175 ms. In addition, modifications in some behavioral parameters accumulate over tens of seconds and effects last for at least 30 s from trial to trial. These results suggest that larvae establish an internal representation of the visual feedback expected from a given motor output and that the behavioral modifications are driven by an error signal that arises from the discrepancy between this expectation and the actual visual feedback. The assay we develop presents a unique possibility for studying visuomotor integration using imaging techniques available in the larval zebrafish.

  15. Microhabitat influence on larval fish assemblages within ...

    Science.gov (United States)

    We examined larval and juvenile fish assemblage structure in relation to microhabitat variables within the St. Louis River estuary, a drowned river mouth of Lake Superior. Fish were sampled in vegetated beds throughout the estuary, across a gradient of vegetation types and densities (including disturbed, preserved and post-restoration sites). Canonical correspondence analysis, relating species abundances to environmental variables revealed that plant species richness, turbidity and aquatic plant cover were most influential in structuring assemblages. Results from this microhabitat analysis at this crucial life stage has potential to inform wetland restoration efforts within the St. Louis River and other Great Lake coastal wetlands. not applicable

  16. Larval morphology of Metaphycus flavus and its role in host attachment and larval cannibalism.

    Science.gov (United States)

    Tena, A; Kapranas, A; Walker, G P; Garcia-Marí, F; Luck, R F

    2011-06-01

    Metaphycus flavus (Howard) (Hymenoptera: Encyrtidae) is a facultatively gregarious endoparasitoid of soft scales (Hemiptera: Coccidae). When it develops in superparasitised hosts, the larvae often attack and consume brood mates six or more days post oviposition. Under our laboratory conditions (25±1°C and 14 hours of light followed by 18±1°C and ten hours of darkness in 50-70% R.H.), M. flavus eggs hatched three days after oviposition. Measurements of the mandibles and tentorium indicate there are four larval instars, and M. flavus reaches the fourth instar by day six post oviposition, and pupates on day eight. Thus, cannibalism among M. flavus larvae occurs during the fourth instar. During this instar, M. flavus larvae separate from their attachment to the scale cuticle, to which they were tethered by a respiratory structure during the previous three larval instars. Once detached, they are free to move within the scale, which increases the probability of larval encounters and aggressive behaviours. Moreover, the mandibles of the fourth instar are better adapted for fighting than are those of the first three larval instars, since they are larger and more sclerotized. The cranium and mouthparts of M. flavus have four different types of sensory organs, some of which are almost certainly olfactory, an unexpected function for a larva that presumably is surrounded by an aqueous medium where gustatory sensilla would seem to be more appropriate. The cranium also bears two pairs of what appear to be secretory pores.

  17. Influence of Physiological Stress on Nutrient Stoichiometry in Larval Amphibians.

    Science.gov (United States)

    Kirschman, Lucas J; Haslett, Savhannah; Fritz, Kelley A; Whiles, Matt R; Warne, Robin W

    2016-01-01

    Exposure to environmental stressors alters animal phenotypes as well as nutrient metabolism, assimilation, and excretion. While stress-induced shifts in nutrient processes are known to alter organismal carbon (C) and nitrogen (N) stoichiometry, there has been little exploration of how environmental factors influence phosphorous (P). A better understanding of how P cycling varies with animal physiological state may provide insight into across-scale processes, because P is essential to animal function and ecological processes such as production and decomposition. We tested the effects of predator stress and exogenous glucocorticoids on C∶N∶P stoichiometry of larval amphibians. Glucocorticoids altered nutrient stoichiometry, apparently by modulating ossification and renal function. This reduced whole-body P and significantly increased N∶P. Additionally, elevated glucocorticoids caused a long-term reduction in P excretion. This reduction may reflect an initial unmeasured loss of P that glucocorticoids induce over acute timescales. In contrast, exposure to predator cues had no effect on larval C∶N∶P stoichiometry, which highlights that different stressors have varied effects on the endocrine stress response. Predation, in particular, is ubiquitous in the environment; thus, larvae responding to predators have conserved mechanisms that likely prevent or minimize physiological disruption. These results demonstrate the differing physiological roles of N and P, distinct nutrient demands associated with amphibian metamorphosis, and the contrasting effects that different environmental factors have on the physiological stress response. Our results also suggest that anthropogenic changes to the environment that induce chronic stress in amphibians could affect the biogeochemistry of nutrient-poor environments where they may act as keystone species.

  18. Food allergy: an overview.

    OpenAIRE

    Kagan, Rhoda Sheryl

    2003-01-01

    Food allergy affects between 5% and 7.5% of children and between 1% and 2% of adults. The greater prevalence of food allergy in children reflects both the increased predisposition of children to develop food allergies and the development of immunologic tolerance to certain foods over time. Immunoglobulin (Ig) E-mediated food allergies can be classified as those that persist indefinitely and those that are predominantly transient. Although there is overlap between the two groups, certain foods...

  19. Energy-restricted diets based on a distinct food selection affecting the glycemic index induce different weight loss and oxidative response.

    Science.gov (United States)

    Abete, Itziar; Parra, Dolores; Martinez, J Alfredo

    2008-08-01

    Low glycemic index (GI) based diets could influence the accompanying physiological adaptations to energy restriction in the treatment of obesity. It was aimed to investigate the effects of two energy-restricted diets with different food distribution and GI values on weight loss and energy metabolism in the nutritional treatment of obesity. Participants (n=32; BMI: 32.5+/-4.3 kg/m(2)) were randomly assigned to follow two energy-restricted diets with higher-GI or lower-GI for 8 weeks. The energy restriction was -30% in relation to energy expenditure. Anthropometry, energy expenditure and mitochondrial oxidation were assessed at baseline and at the endpoint of the intervention. Body weight was also measured one year after the treatment. The work was approved by the ethical committees of the University of Navarra (54/2006). Volunteers consuming the lower-GI diet showed a significantly higher weight loss than their counterparts (-5.3+/-2.6% vs -7.5+/-2.9%; p=0.032), although the decrease in resting energy expenditure (REE) was similar between groups (p=0.783). Mitochondrial oxidation was significantly affected by the type of diet (p=0.001), being activated after the lower-GI treatment (p=0.022). Interestingly, one year after the nutritional intervention weight regain was only statistically significant in the higher-GI group (p=0.033). Lower-GI energy-restricted diets achieved through a specific differential food selection can improve the energy adaptations during obesity treatment, favouring weight loss and probably weight maintenance compared with higher-GI hypocaloric diets.

  20. Acquisition of Borrelia burgdorferi infection by larval Ixodes scapularis (Acari: Ixodidae) associated with engorgement measures

    Science.gov (United States)

    Couret, Janelle; Dyer, M.C.; Mather, T.N.; Han, S.; Tsao, J.I.; LeBrun, R.A.; Ginsberg, Howard

    2017-01-01

    Measuring rates of acquisition of the Lyme disease pathogen, Borrelia burgdorferi sensu lato Johnson, Schmid, Hyde, Steigerwalt & Brenner, by the larval stage of Ixodes scapularis Say is a useful tool for xenodiagnoses of B. burgdorferi in vertebrate hosts. In the nymphal and adult stages of I. scapularis, the duration of attachment to hosts has been shown to predict both body engorgement during blood feeding and the timing of infection with B. burgdorferi. However, these relationships have not been established for the larval stage of I. scapularis. We sought to establish the relationship between body size during engorgement of larval I. scapularis placed on B. burgdorferi-infected, white-footed mice (Peromyscus leucopus Rafinesque) and the presence or absence of infection in larvae sampled from hosts over time. Body size, time, and their interaction were the best predictors of larval infection with B. burgdorferi. We found that infected larvae showed significantly greater engorgement than uninfected larvae as early as 24 h after placement on a host. These findings may suggest that infection with B. burgdorferi affects the larval feeding process. Alternatively, larvae that engorge more rapidly on hosts may acquire infections faster. Knowledge of these relationships can be applied to improve effective xenodiagnosis of B. burgdorferi in white-footed mice. Further, these findings shed light on vector–pathogen–host interactions during an understudied part of the Lyme disease transmission cycle.

  1. Flavonoid-mediated inhibition of intestinal ABC transporters may affect the oral bioavailability of drugs, food-borne toxic compounds and bioactive ingredients

    NARCIS (Netherlands)

    Brand, W.; Schutte, M.E.; Bladeren, van P.J.; Rietjens, I.M.C.M.

    2006-01-01

    The transcellular transport of ingested food ingredients across the intestinal epithelial barrier is an important factor determining bioavailability upon oral intake. This transcellular transport of many chemicals, food ingredients, drugs or toxic compounds over the intestinal epithelium can be high

  2. Flavonoid-mediated inhibition of intestinal ABC transporters may affect the oral bioavailability of drugs, food-borne toxic compounds and bioactive ingredients

    NARCIS (Netherlands)

    Brand, W.; Schutte, M.E.; Bladeren, van P.J.; Rietjens, I.M.C.M.

    2006-01-01

    The transcellular transport of ingested food ingredients across the intestinal epithelial barrier is an important factor determining bioavailability upon oral intake. This transcellular transport of many chemicals, food ingredients, drugs or toxic compounds over the intestinal epithelium can be high

  3. Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem

    Science.gov (United States)

    2015-01-01

    Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with

  4. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

    Directory of Open Access Journals (Sweden)

    Ori Segev

    Full Text Available Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail on Near Eastern fire salamander (Salamandra infraimmaculata larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

  5. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

    Science.gov (United States)

    Segev, Ori; Polevikove, Antonina; Blank, Lior; Goedbloed, Daniel; Küpfer, Eliane; Gershberg, Anna; Koplovich, Avi; Blaustein, Leon

    2015-01-01

    Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern fire salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

  6. Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

    Science.gov (United States)

    Walsh, Harvey J; Richardson, David E; Marancik, Katrin E; Hare, Jonathan A

    2015-01-01

    Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with

  7. Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

    Directory of Open Access Journals (Sweden)

    Harvey J Walsh

    Full Text Available Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf. Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf

  8. Fisheries Closed Areas Strengthen Scallop Larval Settlement and Connectivity Among Closed Areas and Across International Open Fishing Grounds: A Model Study

    Science.gov (United States)

    Davies, Kimberley T. A.; Gentleman, W. C.; DiBacco, C.; Johnson, C. L.

    2015-09-01

    This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.

  9. Students’ beliefs and behaviour regarding low-calorie beverages, sweets or snacks: are they affected by lessons on healthy food and by changes to school vending machines?

    NARCIS (Netherlands)

    Kocken, P.L.; Kesteren, N.M.C. van; Buijs, G.; Snel, J.; Dusseldorp, E.

    2015-01-01

    Objective To study the effects of school lessons about healthy food on adolescents’ self-reported beliefs and behaviour regarding the purchase and consumption of soft drinks, water and extra foods, including sweets and snacks. The lessons were combined with the introduction of lower-calorie foods,

  10. Students’ beliefs and behaviour regarding low-calorie beverages, sweets or snacks: are they affected by lessons on healthy food and by changes to school vending machines?

    NARCIS (Netherlands)

    Kocken, P.L.; Kesteren, N.M.C. van; Buijs, G.; Snel, J.; Dusseldorp, E.

    2015-01-01

    Objective To study the effects of school lessons about healthy food on adolescents’ self-reported beliefs and behaviour regarding the purchase and consumption of soft drinks, water and extra foods, including sweets and snacks. The lessons were combined with the introduction of lower-calorie foods, f

  11. Students’ beliefs and behaviour regarding low-calorie beverages, sweets or snacks: are they affected by lessons on healthy food and by changes to school vending machines?

    NARCIS (Netherlands)

    Kocken, P.L.; Kesteren, N.M.C. van; Buijs, G.; Snel, J.; Dusseldorp, E.

    2015-01-01

    Objective To study the effects of school lessons about healthy food on adolescents’ self-reported beliefs and behaviour regarding the purchase and consumption of soft drinks, water and extra foods, including sweets and snacks. The lessons were combined with the introduction of lower-calorie foods, f

  12. The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development

    Science.gov (United States)

    De Marco, Rodrigo J.; Groneberg, Antonia H.; Yeh, Chen-Min; Treviño, Mario; Ryu, Soojin

    2014-01-01

    The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging. PMID:25368561

  13. Social facilitation of eating novel food in tufted capuchin monkeys (Cebus apella): input provided by group members and responses affected in the observer.

    Science.gov (United States)

    Addessi, E; Visalberghi, E

    2001-11-01

    Learning about food palatability from watching what conspecifics eat might be one of the advantages of group living. A previous study investigated whether group members' presence or eating activity account for social facilitation of eating of foods never previously tasted. Capuchins encountered novel colored foods when (1) alone (Alone condition) or (2) with group members visible in the nearby cage (Group-present condition) or (3) with group members present and eating a familiar food that had not been colored (Group+food condition). Social facilitation of eating occurred when group members were eating, despite the difference in color between the familiar food eaten by them and the novel food presented to the experimental subject. To clarify what subjects learnt from group members when social facilitation occurred, we further analyze here the data from the previous study. The number of visual exposures to the colored novel food (as a group member) correlated with increased consumption of that novel food when encountered later (as experimental subject). In contrast, the number of times that an individual fed on the familiar food (as a group member) did not decrease its consumption of novel food (as experimental subject). Therefore, capuchins (1) habituated to the colors of the novel foods, and (2) did not take into account that seeing group members eating a food does not provide information about the palatability of a differently colored food. Since social facilitation of eating occurs when foods do not match in color, at least in capuchins, social facilitation of eating should not be considered as a way of learning about a safe diet, but rather as a way of overcoming neophobia.

  14. EFFECTS OF THALLIUM ON THE LARVAL DEVELOPMENT OF LUCILIA SERICATA MEIGEN 1826 AND PMI ESTIMATION

    Directory of Open Access Journals (Sweden)

    Arif Gökhan BAŞARAN

    2011-08-01

    Full Text Available Determination of larval growth rate of and forensic analysis of the age of Calliphoridae larvae on a corpse are useful evidence in legal investigations for the estimation of exact death time and time duration after death; post mortem interval. However many factors, such as temperature, tissue type and contamination of drugs and toxins, effect larval development of blow fly larvae and consequently theestimation of post mortem interval. The present study examined the larval growth rate of a forensically important blow fly species, Lucilia sericata Meigen 1826 in different concentrations (0,12; 0,25; 0,50; 1 and 2 μg/g of toxic heavy metal Thallium under controlled laboratory conditions. Body length and weight, death ratio of larvae and pupa between experimental and control groups were compared. Results demonstrated that the development rate of larvae between uncontaminated and contaminated diets varies significantly. In short, they molted later, reached maximum length more slowly and sometimesproduced significantly smaller pupae in contaminated food source. These results emphasized that the importance of determining the contamination rate of toxins in tissue for the forensic entomologist,while using development rates from standard curves based on larvae fed non-contaminated mediums.

  15. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Elmore, Logan R [ORNL; McCracken, Kitty [ORNL

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the

  16. Elevated copper levels during larval development cause altered locomotor behavior in the adult carabid beetle Pterostichus cupreus L. (Coleoptera: Carbidae)

    DEFF Research Database (Denmark)

    Bayley, M; Baatrup, E; Heimbach, U

    1995-01-01

    It is generally believed that copper causes changes in carabid communities indirectly by reducing food availability, because these animals are frequently found to have only slightly elevated metal contents even close to pollution sources. Using computer-centered video tracking, the locomotor...... behavior of adult Pterostichus cupreus carabid beetles was quantified after being raised on copper-contaminated food and soil during larval development. Copper was found to have an acute toxic effect measured in larval mortality, to cause a slight increase in the developmental period of males......, but not to effect the emergence weights of adults of either sex. This toxic effect on the larvae was preserved through pupation to the surviving adults, which were normal in size and appearance, but displayed a dramatically depressed locomotor behavior. Copper analysis of these adults revealed that copper levels...

  17. Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

    Science.gov (United States)

    Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

    2014-04-01

    The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability.

  18. Larval fish assemblages in a tropical mangrove estuary and adjacent coastal waters: Offshore-inshore flux of marine and estuarine species

    Science.gov (United States)

    Ooi, A. L.; Chong, V. C.

    2011-10-01

    A total of 92,934 fish larvae representing 19 families were sampled monthly from the Sangga Kecil estuary (Matang Mangrove Forest Reserve) and adjacent coastal waters from May 2002 to October 2003. Larval fish assemblages were numerically dominated by Gobiidae (50.1%) and Engraulidae (38.4%). Canonical Correspondence Analysis (CCA) revealed that the larval fish assemblages, including their ontogenetic stages, differed between the mangrove estuary and adjacent offshore waters, and that salinity, turbidity and zooplankton food are the major environmental factors structuring the larval fish assemblages. Estuarine preflexion gobiid larvae were ubiquitous in the coastal and estuarine waters. Larval stages of euryhaline species that were spawned in offshore waters, such as Engraulidae and Clupeidae, were largely advected into mangrove areas at the postflexion stages. Larvae of other euryhaline fishes (Sciaenidae, Blenniidae and Cynoglossidae) that may have been spawned inside the estuary were, however, exported to offshore waters. Given that the collective number of juvenile and adult fish families in the Matang estuary was 53, while the number of larval families was only 17, the former is quite disconnected from the existing larval fish population in the estuary.

  19. EFFECT OF TOURISM ON THE DISTRIBUTION OF LARVAL BLACKFLIES (DIPTERA: SIMULIUM) IN PALNI HILLS OF SOUTH INDIA

    Institute of Scientific and Technical Information of China (English)

    Sankarappan Anbalagan; Sundaram Dinakaran; Jeyaraj Pandiarajan; Muthukalingan Krishnan

    2011-01-01

    The effect of tourism on the distribution of larval blackflies during three different seasons of Palni hills was investigated. Six streams were selected (Kumbakkarai, Moolayar, Kurusedi, Silver cascade Pampar and Guntar) for this study, of which, three streams (Silver cascade Pampar and Guntar) were in peak of Palni hills (Kodaikanal town areas)and easy access to the tourists. The remaining three streams (Kumbakkarai, Moolayar and Kurusedi) were in downhill areas. The physico-chemical and stream parameters analyses indicated that the most tourist accessible site of Silver cascade stream had poor water quality and the predominant of larval blackfly population when compared to other sampling streams. The highest population of larval blackflies was observed during winter followed by summer and northeast monsoon. Since the effect of tourism causes pollution to streams, which in turn to promote the population of blackfly larvae and affect the other insect community in streams.

  20. Scanning electron microscopy of the four larval instars of the Dengue fever vector Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Schaper, Stefan; Hernández-Chavarría, Francisco

    2006-09-01

    Aedes aegypti is the main insect vector of Dengue fever and dengue hemorrhagic fever/dengue shock syndrome and represents the only vulnerable element in the control of this disease. Therefore, the identification and quantification of this mosquito is an important task; however, the majority of taxonomic keys are based on the 4th larval instar. For that reason, this study describes the four larval instars ofA. aegypti using scanning electron microscopy. Morphological changes during larval development were observed at the pecten, comb scales and the ventral brush of the abdominal segment X; however, the 3rd and 4th instars showed similar structures with only a slight variation. The structures described in this study will be helpful in the identification of the four instars of A. aegypti, a fundamental task for comprehending the natural history of dengue mainly in new territories affected.

  1. Recruitment decline in North Sea herring is accompanied by reduced larval growth rates

    DEFF Research Database (Denmark)

    Payne, Mark; Ross, Stine Dalmann; Worsøe Clausen, Lotte

    2013-01-01

    estimated for two hundred larvae from four different years using a model-based analysis of the otolith ring-widths. Hydrographic-backtracking models complemented the otolith analysis by reconstructing the environmental history and spawning origin of each larva. A significant reduction in net larval growth...... of available food. The study demonstrates the potential in coupling of two different techniques, the otolith microstructure analysis and the hydrographic modelling, for affording new insights into fish early-life history. Finally, the study provides a novel indication of the association between reduced growth...

  2. Larval development of Evermannia zosterura (Perciformes: Gobiidae).

    Science.gov (United States)

    González-Navarro, Enrique; Saldierna-Martínez, Ricardo Javier; Aceves-Medina, Gerardo

    2014-06-01

    Gobiidae is the most specious fish family in the world with almost 2 000 species, however only 11% of them have been described for their larval stages. The entire life cycle information is essential to understand the biology and ecology of this important fish group. Previous studies on zooplankton samples from Ensenada de La Paz, México, have shown the presence of several Gobiidae larvae and juveniles which were identified as Evermania zosterura. The main objective of this work was to describe the larval stages of this species, widely distributed in the Eastern tropical Pacific. The development of E. zosterura larvae was described based on 66 specimens. A total of 53 specimens were used to describe morphometrics and pigmentation patterns, while 13 specimens were cleared and stained, to obtain meristic characteristics. Cleared specimens had 30 to 31 total vertebrae; dorsal-fin elements: IV; 1, 13-14, anal-fin elements: 1, 13-14, and most had pterygiophore formula 4-111100. The combination of these characteristics confirmed these specimens as E. zosterura. The pigment pattern is similar throughout ontogeny. Larvae are characterized by having three to five dendritic melanophores along the post-anal ventral margin, four to nine smaller melanophores along the ventral margin between the isthmus and anus, and one on the midpoint of the dorsal margin of the tail. There is one small pigment spot on the angle of the jaw, and other on the tip of lower lip. There is an elongated internal pigment under the notochord, between the head and gas bladder. Notochord flexion starts near 3.5mm BL and ends at 4.6mm BL; transformalion to the juvenile stage is at about 13.6mm BL. Our conclusion is that the most useful characters to distinguish this species early-larval stages from those of similar species in the area, are the number of myomeres, the large melanophores (approximately uniformly in size) on the post anal ventral margin, and the elongate internal pigment under the notochord

  3. Turbulence-enhanced prey encounter rates in larval fish : Effects of spatial scale, larval behaviour and size

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; MacKenzie, Brian

    1995-01-01

    Turbulent water motion has several effects on the feeding ecology of larval fish and other planktivorous predators. In this paper, we consider the appropriate spatial scales for estimating relative velocities between larval fish predators and their prey, and the effect that different choices...

  4. Sandeel ( Ammodytes marinus ) larval transport patterns in the North Sea from an individual-based hydrodynamic egg and larval model

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Jensen, Henrik; Mosegaard, Henrik

    2008-01-01

    is modelled by a stochastic, nonlinear degree-day model describing the extended hatch period. The larval growth model is parameterized by individually back-tracking the local physical environment of larval survivors from their catch location and catch time. Using a detailed map of sandeel habitats...

  5. Adult and larval traits as determinants of geographic range size among tropical reef fishes.

    Science.gov (United States)

    Luiz, Osmar J; Allen, Andrew P; Robertson, D Ross; Floeter, Sergio R; Kulbicki, Michel; Vigliola, Laurent; Becheler, Ronan; Madin, Joshua S

    2013-10-01

    Most marine organisms disperse via ocean currents as larvae, so it is often assumed that larval-stage duration is the primary determinant of geographic range size. However, empirical tests of this relationship have yielded mixed results, and alternative hypotheses have rarely been considered. Here we assess the relative influence of adult and larval-traits on geographic range size using a global dataset encompassing 590 species of tropical reef fishes in 47 families, the largest compilation of such data to date for any marine group. We analyze this database using linear mixed-effect models to control for phylogeny and geographical limits on range size. Our analysis indicates that three adult traits likely to affect the capacity of new colonizers to survive and establish reproductive populations (body size, schooling behavior, and nocturnal activity) are equal or better predictors of geographic range size than pelagic larval duration. We conclude that adult life-history traits that affect the postdispersal persistence of new populations are primary determinants of successful range extension and, consequently, of geographic range size among tropical reef fishes.

  6. New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory

    Directory of Open Access Journals (Sweden)

    Cherre Sade Bezerra Da Silva

    2013-09-01

    Full Text Available New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory. Here we show, for the first time, that larvae of the fall armyworm (FAW, Spodoptera frugiperda (Lepidoptera, Noctuidae, can be successfully reared in a cohort-based manner with virtually no cannibalism. FAW larvae were reared since the second instar to pupation in rectangular plastic containers containing 40 individuals with a surprisingly ca. 90% larval survivorship. Adult females from the cohort-based method showed fecundity similar to that already reported on literature for larvae reared individually, and fertility higher than 99%, with the advantage of combining economy of time, space and material resources. These findings suggest that the factors affecting cannibalism of FAW larvae in laboratory rearings need to be reevaluated, whilst the new technique also show potential to increase the efficiency of both small and mass FAW rearings.

  7. Effect of temperature on feeding period of larval blacklegged ticks (Acari: Ixodidae) on eastern fence lizards

    Science.gov (United States)

    Rulison, Eric L.; LeBrun, Roger A.; Ginsberg, Howard S.

    2014-01-01

    Ambient temperature can influence tick development time, and can potentially affect tick interactions with pathogens and with vertebrate hosts. We studied the effect of ambient temperature on duration of attachment of larval blacklegged ticks, Ixodes scapularis Say, to eastern fence lizards, Sceloporus undulatus (Bose & Daudin). Feeding periods of larvae that attached to lizards under preferred temperature conditions for the lizards (WARM treatment: temperatures averaged 36.6°C at the top of the cage and 25.8°C at the bottom, allowing behavioral thermoregulation) were shorter than for larvae on lizards held under cool conditions (COOL treatment temperatures averaged 28.4°C at top of cage and 24.9°C at the bottom). The lizards were infested with larvae four times at roughly monthly intervals. Larval numbers successfully engorging and dropping declined and feeding period was longer after the first infestation.

  8. Coastal pollution limits pelagic larval dispersal.

    Science.gov (United States)

    Puritz, Jonathan B; Toonen, Robert J

    2011-01-01

    The ecological impact of large coastal human populations on marine ecosystems remains relatively unknown. Here, we examine the population structure of Patiria miniata, the bat star, and correlate genetic distances with a model based on flow rates and proximity to P. miniata populations for the four major stormwater runoff and wastewater effluent sources of the Southern California Bight. We show that overall genetic connectivity is high (F(ST)~0.005); however, multivariate analyses show that genetic structure is highly correlated with anthropogenic inputs. The best models included both stormwater and wastewater variables and explained between 26.55 and 93.69% of the observed structure. Additionally, regressions between allelic richness and distance to sources show that populations near anthropogenic pollution have reduced genetic diversity. Our results indicate that anthropogenic runoff and effluent are acting as barriers to larval dispersal, effectively isolating a high gene flow species that is virtually free of direct human impact.

  9. Modelling larval movement data from individual bioassays.

    Science.gov (United States)

    McLellan, Chris R; Worton, Bruce J; Deasy, William; Birch, A Nicholas E

    2015-05-01

    We consider modelling the movements of larvae using individual bioassays in which data are collected at a high-frequency rate of five observations per second. The aim is to characterize the behaviour of the larvae when exposed to attractant and repellent compounds. Mixtures of diffusion processes, as well as Hidden Markov models, are proposed as models of larval movement. These models account for directed and localized movements, and successfully distinguish between the behaviour of larvae exposed to attractant and repellent compounds. A simulation study illustrates the advantage of using a Hidden Markov model rather than a simpler mixture model. Practical aspects of model estimation and inference are considered on extensive data collected in a study of novel approaches for the management of cabbage root fly.

  10. Effect of maize lines on larval fitness costs of Cry1F resistance in the European corn borer (Lepidoptera: Crambidae).

    Science.gov (United States)

    Petzold-Maxwell, Jennifer L; Siegfried, Blair D; Hellmich, Richard L; Abel, Craig A; Coates, Brad S; Spencer, Terrence A; Gassmann, Aaron J

    2014-04-01

    Crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) are widely planted and enable management of key insect pests while reducing the use of conventional insecticides. However, the evolution of Bt resistance could diminish these benefits. Fitness costs of Bt resistance occur in the absence of Bt toxin when individuals with resistance alleles show a reduction in fitness relative to susceptible individuals, and they can delay the evolution of resistance. Ecological factors including host-plant variety can affect the magnitude of fitness costs, and consequently, the degree to which fitness costs delay resistance. In this study, we measured fitness costs of resistance to Bt toxin Cry1F in the European corn borer Ostrinia nubilalis Hübner (Lepidoptera: Crambidae) using Cry1F-resistant and Cry1F-susceptible strains sharing a similar genetic background. Fitness costs were tested on three lines of maize, Zea mays L., by measuring larval survival and development in two greenhouse experiments with plants in either the vegetative or reproductive stage. Both experiments showed that maize line significantly affected larval survival and developmental rate. However, larval survival, mass, and developmental rate did not differ between the Cry1F-resistant and susceptible strains, indicating a lack of fitness costs of resistance to Cry1F for the larval fitness components measured in this experiment. Future experiments should test for fitness costs of Cry1F resistance affecting survival to adulthood and adult life-history parameters.

  11. Evaluating the effects of trophic complexity on a keystone predator by disassembling a partial intraguild predation food web.

    Science.gov (United States)

    Davenport, Jon M; Chalcraft, David R

    2012-01-01

    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 and can function as keystone predators. Larval A. opacum are also found in simpler food webs lacking either top predators or shared prey. 2. We conducted an experiment where a partial IGP food web was simplified, and we measured the growth and survival of larval A. opacum in each set of food webs. Partial IGP food webs that had either a low abundance or high abundance of total prey were also simplified by independently removing top predators and/or shared prey. 3. Removing top predators always increased A. opacum survival, but removal of shared prey had no effect on A. opacum survival, regardless of total prey abundance. 4. Surprisingly, food web simplification had no effect on the growth of A. opacum when present in food webs with a low abundance of prey but had important effects on A. opacum growth in food webs with a high abundance of prey. Simplifying a partial IGP food web with a high abundance of prey reduced A. opacum growth when either top predators or shared prey were removed from the food web and the loss of top predators and shared prey influenced A. opacum growth in a non-additive fashion. 5. The non-additive response in A. opacum growth appears to be the result of supplemental prey availability augmenting the beneficial effects of top predators. Top predators had a beneficial effect on A. opacum populations by reducing the abundance of A. opacum present and thereby