Find research datasets worth reusing

You are what your host eats: The trophic structure and food chain length of a symbiont community are coupled with the plastic diet of the host ant

Food chain length provides key information on the flow of nutrients and energy in ecosystems. Variation in food chain length has primarily been explained by environmental drivers such as ecosystem size and productivity. Most insights are obtained from theory or aquatic systems, but the importance of these drivers remains largely untested in terrestrial systems. We exploited red wood ant nests markedly differing in size as natural experiments to quantify the drivers of trophic structure and food chain length of their symbiont arthropod communities. Using stable isotopes, we explored the variation in the trophic positions of four symbiont species with the trophic position of the top predator as a proxy for food chain length of the symbiont community. Nest size did not affect food chain length, nor trophic distance between the symbionts. Instead, food chain length and the trophic positions of the symbionts were strongly affected by the host's foraging decisions. When the host diet shifted from predominantly herbivorous to more predacious, the trophic position of the symbionts and food chain length strongly increased. We show for the first time that a food web can be structured by biotic interactions with an engineering species rather than by abiotic environmental variable

Periprandial changes in brain serotonergic system and food intake related neuropeptides

In this work, we assessed periprandial serotonin and 5-hydroxyindolacetic acid abundance in several brain areas of rainbow trout, in parallel with the evaluation of gene expression of tryptophan hydroxilase 1 and 2, neuropeptides involved in the central control of food intake, and the quantification of plasma glucose and cortisol. The results showed severe changes in serotonergic systems around mealtime, the most prominent being the increase in their activity just after food intake, suggesting that serotonin has a relevant role in relation to the daily timing of food intake, probably triggering satiety signals. In addition, a temporal adjustment of neuropeptide expression and plasma cortisol was found in relation to food intake, supporting its role in the regulation of feeding behaviour.

opencc-by-4.0Aug 2023View details →

Simulation of the Moving Boundary during Freezing of a One-Dimensional Food Slab

To calculate the moving boundary (MB) of a finite 1D moist food slab,  which is cooled by convection at the exposed surface, a finite  difference model was employed, invoking the Stefan condition. The  primary objective of this project was to generate synthetic data  comprising MB position-time pairs. The MB time profiles were generated  using a nearly orthogonal array, which accounts for the effects of the Biot number, dimensionless  cooling-medium temperature, dimensionless latent heat, and thermal  conductivity parameter. The last two parameters play a crucial role in  controlling the temperature dependence of the effective heat capacity  and thermal conductivity of the food material. The generated data will  be utilized to develop statistical models of the MB, effectively  accounting for the influence of temperature-dependent thermal properties

Physiology of the widespread pulsating soft coral Xenia umbellata is affected by food sources, but not by water flow

Coral energy and nutrient acquisition strategies are complex and sensitive to environmental conditions such as water flow. While high water flow can enhance feeding in hard corals, knowledge about the effects of water flow on the feeding of soft corals, particularly those pulsating, is still limited. In this study, we thus investigated the effects of feeding and water flow on the physiology of the pulsating soft coral Xenia umbellata. We crossed three feeding treatments i) no feeding, ii) particulate organic matter [POM] as phytoplankton, and iii) dissolved organic carbon [DOC] as glucose, with four water volume exchange rates (200, 350, 500 and 650 Lh-1) over 15 days. Various ecophysiological parameters were assessed including pulsation rate, growth rate, isotopic and elemental ratios of carbon (C) and nitrogen (N) as well as photo-physiological parameters of the Symbiodiniaceae (cell density, chlorophyll-a and mitotic index). Water flow had no significant effect but feeding had a substantial impact on the physiology of the X. umbellata holobiont. In the absence of food, corals exhibited significantly lower pulsation rates, lower Symbiodiniaceae cell density, and lower mitotic indices compared to the fed treatments, yet significantly higher chlorophyll-a per cell and total N content. Differences were also observed between the two feeding treatments, with significantly higher pulsation rates and lower chlorophyll-a per cell in the DOC treatment, but higher C and N content in the POM treatment. Our findings suggest that the X. umbellata holobiont can be viable under different trophic strategies, though favouring mixotrophy. Additionally, the physiology of the X. umbellata may be regulated through its own pulsating behaviour without any positive nor negative effects from different water flow. Thus, this study contributes to our understanding of soft coral ecology, particularly regarding the competitive success and widespread distribution of X. umbellata.

Behavioural thermoregulation and food availability drives fine-scale seasonal habitat partitioning in limpets

<ol> <li>Small-scale spatial variation in temperature plays a key role in limiting the distribution of organisms in thermally heterogeneous environments. In the rocky intertidal zone, intra-day temperature variation at small scales (cm-m) can easily exceed 30°C.</li> <li>To experimentally test the impact of this small-scale temperature heterogeneity on the distribution of an ecologically important limpet species (Cellana denticulata), boulders on an intertidal rocky reef in New Zealand were rotated, and small-scale temperature variability and food availability were measured throughout one year. Small-scale variability in thermal tolerance, heart rate, and heat shock protein expression was also measured to relate in situ limpet distributions with environmental conditions. Temperature variability was measured using limpet bio-mimics and HOBO pendant temperature loggers, while food availability (chlorophyll a concentration) was measured on in situ concrete fiberboard tiles.</li> <li>To measure limpet distributions, every tagged limpet on each of 18 boulders was followed from June 2021–2022. During each sampling, the location of each limpet, compass direction, and slope of the surface that each limpet inhabited were measured. To test for physiological differences among limpets from each microhabitat, thermal tolerance, and heat shock protein expression were measured in collected limpets; in situ heart rates and body temperatures were also measured sporadically on hot days.</li> <li>Maximum predicted body temperatures (36–39°C), heart rates, and actual body temperatures were greatest on equatorial surfaces (i.e., surfaces facing the equator) whereas food availability was greatest on poleward-facing surfaces. During summer, limpets moved towards surfaces that minimised their body temperatures and maximised food availability, namely vertical and poleward facing surfaces and undersides of boulders.</li> <li>Thermal tolerance, measured using Arrhenius breakpoint temperatures (mean ± SE: 34.7–35.8 ± 0.4–0.7°C) and flat line temperatures (36.2–37.4 ± 0.3–0.4°C), were similar among limpets facing different directions. Surprisingly, heat shock protein expression was relatively consistent throughout the year and among directions.</li> <li>Overall, limpet populations are resilient to thermal stress because they effectively use behavioural thermoregulation to exploit cooler microhabitats that also have greater food availability during summer.</li> </ol>

Data for: Fear before food: Scale-dependence in elk habitat selection

<ol> <li>Habitat selection is a critical aspect of a species' ecology requiring complex decision-making that is both hierarchical and scale-dependent, since factors that influence selection may be nested or unequal across scales.</li> <li>Elk (Cervus canadensis) ranged widely across diverse habitats in North America prior to European settlement and subsequent eastern extirpation. Most habitat studies have occurred within their contemporary western range, even after eastern elk reintroductions began. As habitat selection can vary by geographic location, available cover, season, and diel period, it is important to understand how a non-migratory, reintroduced population in northern Wisconsin, USA is limited by the lack of variation in topography, elevation, and vegetation.</li> <li>We tested scale-dependent habitat selection on 79 adult elk from 2017–2020. We used resource selection functions across both temporal and spatial scales to understand differences in selection of topographic and environmental features.</li> <li>We found that selection varied both spatially and temporally and elk selected areas with the greatest potential to influence fitness at larger scales (i.e., landscape scale), meaning elk selected areas closer to escape cover and further from "risky" features (e.g., wolf territory centers, county roads and highways). We found stronger avoidance to wolf territory centers during spring, suggesting elk were selecting safer habitats during calving season. We found elk selected habitats with less canopy cover across both spatial scales and all seasons, suggesting that elk selected these areas for better access to forage as forest stands in early seral stages have greater nutritional value and forage biomass than closed-canopy forests and direct solar radiation to provide warmth in the cooler seasons.</li> <li>This study highlights how processes at different spatial and temporal scales influence species' decision-making. It provides insight into the complexity of making informed decisions in which an individual is responding to their immediate environment while simultaneously making decisions in the context of the larger landscape. Scale-dependent behavior is crucial to understand within specific geographic regions as these decisions scale up to influence population dynamics. </li> </ol>

opencc-by-4.0Aug 2023View details →

Supplementary material for "Filter-feeding gelatinous macrozooplankton response to climate change and implications for benthic food supply and global carbon cycle"

Simulation Outputs Description --------------------------- This text file outlines the contents of the simulation outputs utilized in the analysis presented in Clerc et al. (2023). Pre-treated outputs are not provided for storage reasons, but the complete output can be made available upon request. Spatial files are regridded to a 1-degree resolution regular grid using the treatment: cdo remapdis,r360x180 in.nc out.nc. Folder Names: -------------- Here is a brief overview of the content within each folder. - TS_PICONTROL: Globally averaged time series for the PI-control runs spanning 1850-2100. (Units: PgC, or PgC/yr for "fluxes" filenames.) - TS_RCP85: Globally averaged time series for the RCP8.5 runs spanning 1850-2100. (Units: PgC, or PgC/yr for "fluxes" filenames.) - TS_RCP26: Globally averaged time series for the RCP2.6 runs spanning 1850-2100. (Units: PgC, or PgC/yr for "fluxes" filenames.) - EXPORT_LAYERS_PICONTROL: Time-averaged Pi-control flux outputs at specified depth horizons over the indicated period. (Regular 360x180 grid; Units: gC/m2/yr.) - EXPORT_LAYERS_RCP85: Time-averaged RCP8.5 flux outputs at specified depth horizons over the indicated period. (Regular 360x180 grid; Units: gC/m2/yr.) - EXPORT_LAYERS_RCP26: Time-averaged RCP2.6 flux outputs at specified depth horizons over the indicated period. (Regular 360x180 grid; Units: gC/m2/yr.) - SURFACE_LAYERS_RCP85: Vertically integrated (0-300m) time-averaged RCP8.5 outputs over the specified period. (Regular 360x180 grid; Units: mmolC/m3.) - SURFACE_LAYERS_RCP26: Vertically integrated (0-300m) time-averaged RCP2.6 outputs over the specified period. (Regular 360x180 grid; Units: mmolC/m3.) - SURFACE_LAYERS_PICONTROL: Vertically integrated (0-300m) time-averaged PiControl outputs over the specified period. (Regular 360x180 grid; Units: mmolC/m3.) - CHLOROPHYLL: Surface chlorophyll on a 360x180 degree grid, time-averaged over the indicated period. (Units: mg Chl/m3.) - TS_BIOME: Biome-specific averaged time series spanning 1850-2100. (Units: PgC, or PgC/yr for "fluxes" filenames.) - TS_CFLX: Globally averaged carbon uptake time series spanning 1850-2100. (Units: PgC/yr.) - BIOMES: Biome masks on a regular 360x180 grid. Filename Conventions: ----------------------- Please refer to the following conventions for filenames. MODEL: - PISCES-FFGM: SLP - PISCES-v2: STD - PISCES-GM: MAC FORCING: - Pi-control: PI - Climate-change scenario: AD PERIOD: - 1881-1900: PRI - 1995-2014: HIS - 2081-2100: FUT DEPTH: - 0-300 m: dmin0_dmax300 - 100 m: ilevel9 - 1000 m: ilevel21 - Seafloor: seafloor BIOMES: - High Chlorophyll: HC - Intermediate Chlorophyll: IC - Low Chlorophyll: LC - Southern Ocean: SO - Arctic Ocean: LCA NetCDF Variables: ------------------ - SALP: Filter-feeding gelatinous Macrozooplankton (FFGM) - ZOO3: Generic Macrozooplankton (GM) - ZOO2: Mesozooplankton - ZOO: Microzooplankton - PHY: Nanophytoplankton - PHY2: Diatoms - POC: Small particles (quantity or flux) - GOC: Large particles (quantity or flux) - SPCC: FFGM carcasses carbon (content or flux) - SPFC: FFGM fecal pellets carbon (content or flux) - MPCC: GM carcasses carbon (content or flux) - MPFC: GM fecal pellets carbon (content or flux) - CHL: Chlorophyll - Cflx: Carbon uptake - NO3: Nitrate - PO4: Phosphate - O2: Oxygen For any inquiries or data access requests, please contact corentin.clerc -at- usys.ethz.ch.

Food quality shapes gradual phenotypic plasticity in ectotherms facing temperature variability

Organisms exhibit reversible physiological adjustments as a response to rapidly changing environments. Yet, such plasticity of the phenotype is gradual and may lag behind the environmental fluctuations, thereby affecting the long-term average performance of the organisms. By supplying energy and essential compounds for optimal tissue building, food determines the range of possible phenotypic changes and potentially the rate at which they occur. Here, we assess how differences in the dietary supply of essential lipids modulate the phenotypic plasticity of an ectotherm facing thermal fluctuations. We use three phytoplankton strains to create a gradient of polyunsaturated fatty acids and sterols supply for Daphnia magna under constant and fluctuating temperatures. We used three different fluctuation periodicities to unravel the temporal dynamics of gradual plasticity and its long-term consequences on D. magna performance measured as juvenile somatic growth rate. In agreement with gradual plasticity theory, we show that in D. magna, fluctuation periodicity determines the differential between observed growth rates and those expected from constant conditions. Most importantly, we show that diet modulates both the size and the direction of the growth rate differential. Overall, we demonstrate that the nutritional context is essential for predicting ectotherm consumers' performance in fluctuating thermal environments.

opencc-zeroSep 2023View details →

An entorhinal-like region in food-caching birds

The mammalian entorhinal cortex routes inputs from diverse sources into the hippocampus. This information is mixed and expressed in the activity of many specialized entorhinal cell types, which are considered indispensable for hippocampal function. However, functionally similar hippocampi exist even in non-mammals that lack an obvious entorhinal cortex, or generally any layered cortex. To address this dilemma, we mapped extrinsic hippocampal connections in chickadees, whose hippocampi are used for remembering numerous food caches. We found a well-delineated structure in these birds that is topologically similar to the entorhinal cortex and interfaces between the hippocampus and other pallial regions. Recordings of this structure revealed entorhinal-like activity, including border and multi-field grid-like cells. These cells were localized to the subregion predicted by anatomical mapping to match the dorsomedial entorhinal cortex. Our findings uncover an anatomical and physiological equivalence of vastly different brains, suggesting a fundamental nature of entorhinal-like computations for hippocampal function.

opencc-zeroDec 2021View details →

Data for: Cessation of grazing causes biodiversity loss and homogenization of soil food webs

There is widespread concern that cessation of grazing in historically grazed ecosystems is causing biotic homogenization and biodiversity loss. We used 12 montane grassland sites along an 800-km north-south gradient across the United Kingdom, to test whether cessation of grazing affects local ɑ- and β-diversity of belowground food webs. We show cessation of grazing leads to strongly decreased ɑ-diversity of most groups of soil microbes and fauna, particularly of relatively rare taxa. In contrast, the β-diversity varied between groups of soil organisms. While most soil microbial communities exhibited increased homogenization after cessation of grazing, we observed decreased homogenization for soil fauna after cessation of grazing. Overall, our results indicate that exclusion of domesticated herbivores from historically grazed montane grasslands has far-ranging negative consequences for diversity of belowground food webs. This underscores the importance of grazers for maintaining the diversity of belowground communities, which play a central role in ecosystem functioning.

opencc-by-4.0Sep 2023View details →

Role of immigrant males and muzzle contacts in the uptake of a novel food by wild vervet monkeys

Data and script used to analyse data for the study: "Role of immigrant males and muzzle contacts in the uptake of a novel food by wild vervet monkeys"

opencc-zeroDec 2022View details →

Creating new littoral zones in a shallow lake to forward-restore an aquatic food web

Freshwater fish communities typically thrive in heterogenous ecosystems that offer various abiotic conditions. However, human impact increasingly leads to loss of this natural heterogeneity and its associated rich fish communities. To reverse this trend, we need guidelines on how to effectively restore or recreate habitats for multiple fish species. Lake Markermeer in the Netherlands is a human-created 70,000-ha lake with a uniform 4 m-water depth, steep shorelines, high wind-induced turbidity, and a declining fish community. In 2016, a forward-looking restoration project newly created a 1000-ha five-island archipelago in this degrading lake, which offered new sheltered shallow waters and deep sand excavations to the fish community. In 2020, we assessed how omnivorous and piscivorous fish species used these new habitats by tracking 78 adult fish of five key species across local and lake scales. We monitored spring arrival of adult fish and assessed local macro-invertebrate and young-of-the-year fish densities. Adult omnivorous Cyprinidae and piscivorous Percidae arrived at the archipelago in early spring, corresponding with expected spawning movements. During the productive summer season, 12 species of young-of-the-year fish appeared along the sheltered shorelines, with particularly high densities of common roach (Rutilus rutilus) and European perch (Perca fluviatilis). This suggests the sheltered, shallow, vegetated waters formed new suitable spawning and recruitment habitat for the fish community. Despite the highest food densities for adult fish in the shallowest habitats (< 2-m), adult fish preferred minimally 2-m deep water. After spawning, most Cyprinidae left the archipelago and moved long distances through the lake system, while most Percidae remained resident. This may be related to (1) high densities of young-of-the-year fish as food for piscivores, (2) medium food densities for omnivores compared to elsewhere in the lake-system, or (3) the attractiveness of 30-m deep sand excavations that were newly created and frequently used by one-third of all tracked fish. New littoral zones and a deep sand excavation constructed in a uniform shallow lake that lacked these habitat types attracted omnivorous and piscivorous fish species within four years. Both feeding guilds used the littoral zones for reproduction and nursery, and notably piscivorous fish became residents year-round.

opencc-by-4.0Jul 2023View details →

Spending on Luxury Food

A subset of the original study on consumers’ willingness to pay for “luxury food” by Hartmann et al. (2016, 2017). The part of the dataset we examine consists of 821 observations of 44 Likert-type items on eating and shopping habits, diet styles, price, and luxury statements in general. One such item is, for example, “I associate a high price in food with particularly good quality”, with coding scheme −2 = ‘strongly disagree’, . . . , +2 = ‘fully agree’. The coding scheme of the remaining items is similar and given in the file luxfood_description.pdf. The last column contains the response of interest in our analysis, which pertains to whether participants would be willing to pay a higher price for a food product that they associate with luxury (v_60), measured again on the ordinal −2 to +2 scale.     References Hartmann, L. H., Nitzko, S., and Spiller, A. (2016). The significance of definitional dimensions of luxury food. British Food Journal, 118(8), 1976–1998. Hartmann, L. H., Nitzko, S., and Spiller, A. (2017). Segmentation of german consumers based on perceived dimensions of luxury food. Journal of Food Products Marketing, 23(7), 733–768 Hoshiyar, A. and Gertheiss, J. (2023). Fusion, Smoothing and Model Selection for Item-on-Item Regression. Proceedings of the 37th International Workshop on Statistical Modelling, Dortmund, Germany, 133–138. Hoshiyar, A., Gertheiss, L.H. and Gertheiss, J. (2023). Regularization and Model Selection for Item-on-Items Regression with Applications to Food Products’ Survey Data. Preprint on Arxiv.

opencc-zeroOct 2023View details →

Warming alters the top-down effect of a common mesopredator in an aquatic food web

Global warming is altering the composition and functioning of both terrestrial and aquatic ecosystems. Most research has focussed on direct effects of warming on species and their population dynamics, while less is known about indirect effects through species interactions. Trophic cascades are especially likely to influence the effects of warming given that trophic levels differ in their response to warming because of differences in metabolism and vital rates such as growth and reproduction. We investigated if the top-down effect of a common mesopredator, the threespine stickleback, alters the impact of warming on a Baltic Sea food web. We manipulated both temperature and the presence of stickleback in mesocosms, and found the stickleback to alter the impact of warming on lower trophic levels. This was through increased consumption of herbivores that exceeded the rate at which the herbivore population could grow under higher temperature, which in turn increased algae biomass compared to a scenario without stickleback, but not compared to conditions under normal temperature. Thus, the mesopredator increased the transfer of biomass to higher trophic levels of the food web when temperature was increased. This stresses the importance of considering the impact of warming on multiple trophic levels and their interactions. Failing to consider differences in responses among trophic levels and the impact this has on their interactions can result in faulty conclusions about the impact of warming on ecosystems.

opencc-by-4.0Oct 2023View details →

Exogenous foods that activate the NRF2 protein: Systematic review

Background: The activation of the NRF2 signaling pathway, whether through natural compounds, diet, or supplements, plays a crucial role in protecting against oxidative stress and promoting health in various aspects. The objective of this research was to identify studies on exogenous foods that activate the NRF2 protein in the scientific literature. Method: A comprehensive literature review was conducted with the aim of identifying manuscripts related to the activation of NRF2 with exogenous foods and their benefits within the human body. This search was carried out through a systematic review of articles in three languages: English and Spanish, using the MEDLINE, MUBMEB, SCIELO, and SCOPUS repositories. Inclusion criteria focused on foods that activate NRF2 and potential benefits, while exclusion criteria encompassed articles that did not discuss activation, unrelated topics, research in languages other than those specified, and those that did not specifically address the study's objective. The search and article filters were implemented during the period from January to February 2023. To minimize biases, filters were applied in multiple stages, beginning with title search and selection, followed by abstract review, and finally, reading the remaining articles to analyze the information relevant to the research. Results: A total of 26 articles were analyzed, which discussed the adaptive mechanism of NRF2 and its role in hormone dose response, the effects of certain foods, health benefits associated with NRF2 activation, antioxidant, and anti-inflammatory effects, altered NRF2 association with aging, and neurodegenerative diseases. Conclusion: The studies support the notion that NRF2 activation plays a fundamental role in promoting health in various spheres, underscoring the relevance of factors such as diet, natural components, and antioxidant supplementation in defending against oxidative stress and its implications for overall well-being. For future research on this topic, it is important to analyze how the population stands regarding the consumption of exogenous foods that activate NRF2, to understand both the consumption, quantity, and frequency of certain foods and whether they are doing so correctly.

opencc-by-4.0Dec 2022View details →

Dataset for Role of Astrophorina sponges (Demospongiae) in food-web interactions at the Flemish Cap (NW Atlantic)

The data include the functions used to develop the trophic/ non-trophic interaction web models, the input files for these models and the Rmarkdown files with the model output.

opencc-zeroOct 2023View details →

Formica fusca ants use aphid supplemented foods to alleviate effects during the acute phase of a fungal infection

The modulation of nutritional intake by animals to combat pathogens is a behaviour which is getting increasing attention. Ant studies using isolated compounds or nutrients in artificial diets have revealed a lot of the dynamics of the behaviour, but natural sources of medicine are yet to be confirmed. Here we explored whether Formica fusca ants exposed to a fungal pathogen can use an artificial diet containing foods spiked with different concentrations of crushed aphids for a medicinal benefit. We show that pathogen exposed colonies adjusted their diet to include more aphid supplemented foods during the acute phase of the infection, reducing the mortality caused by the disease. However, the benefit was only attained when having access to a varied diet, suggesting that while aphids contain nutrients or compounds beneficial against infection, it is a part of a complex nutritional system where costs and benefits of compounds and nutrients need to be moderated.

opencc-zeroDec 2018View details →

Bronze gui food vessel, 11th C BCE

Chinese bronze gui food vessel, 11th C BCE, now in the collection of the Minneapolis Institute of Art. From artsmia.org: *This vessel is among the earliest gui with looped handles, which emerged in the latest period of the Shang dynasty. The surfaces of the vessel are divided into four vertical panels by four flanges on the foot and two flanges and two handles on the body.* More information about the object: https://collections.artsmia.org/art/1068/gui-food-vessel-china Source: Objaverse 1.0 / Sketchfab

opencc-zeroJan 2021View details →

Low-poly Fangding food vessel

This is a low-poly version of [fangding](https://skfb.ly/IzWq) - this one is better for mobile, VR, and AR. 11th Century BCE fangding (food vessel), now in the collection of the Minneapolis Institute of Art. More information about the object [here](https://collections.artsmia.org/index.php?page=detail&id=1143) *This fangding, or "squared ding," shows an interesting development in ding design. Although it is still a raised boxlike vessel on four columnar legs, the decoration shows a tendency toward the abstract, which may have been influenced by contemporary textile design. The principal surface displays a rectangular field of interlocked Ts on a ground of squared spirals framed on three sides by rows of spikes...Notably, all the linear patterns on this small vessel have been filled with a black carbon-based substance, to give added emphasis to the graphic designs. Though not widespread, this technique can be found in other late Shang and early Western Zhou bronzes.* Source: Objaverse 1.0 / Sketchfab