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Diet composition of the lizard P odarcis lilfordi (Lacertidae) on 2 small islands: an individualresource network approach

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Current Zoology 2020年第1期66卷 39-49页

作者： Silvia SANTAmARIA Camilla Aviaaja ENOKSEN jens m.olesen Giacomo TAVECCHIA Andreu ROTGER Jose manuel IGUAL Anna TRAVESET Global Change Research Group Inst.Mediterrani d'Estudis Avanqats(CSIC-UIB)C/Miquel Marques 21E07190 EsporlesMallorcaBalearic IslandsSpain Section for Ecoinformatics&Biodiversity Department of BioscienceAarhus UniversityAarhus C8000Denmark Animal Ecology and Demography Group Inst.Mediterrani d'Estudis Avanqats(CSIC-UIB)C/Miquel Marques 21EsporlesMallorcaBalearic IslandsE07190Spain

Despite it is widely accepted that intrapopulation variation is fundamental to ecological and evolutionary processes,this level of information has only recently been included into network analysis of species/population interactions.When done,it has revealed non-random patterns in the distribution of trophic resources.Nestedness in resource use among individuals is the most recurrent observed pattern,often accompanied by an absence of modularity,but no previous studies examine bipartite modularity.We use network analysis to describe the diet composition of the Balearic endemic lizard Podarcis lilfordi in 2 islets at population and individual levels,based on the occurrence of food items in fecal samples.Our objectives are to 1)compare niche structure at both levels,2)characterize niche partition using nestedness and modularity,and 3)assess how size,sex,season,and spatial location influence niche structure.At population-level niche width was wide,but narrow at the level of the individual.Both islet networks were nested,indicating similar ranking of the food preferences among individuals,but also modular,which was partially explained by seasonality.Sex and body size did not notably affect diet composition.Large niche overlap and therefore possibly relaxed competition were observed among females in one of the islets and during spring on both islets.Likewise,higher modularity in autumn suggests that higher competition could lead to specialization in both populations,because resources are usually scarce in this season.The absence of spatial location influence on niche might respond to fine-grained spatio-temporally distribution of food resources.Behavioral traits,not included in this study,could also influence resource partitioning.

关键词： Balearic Islands individual diet composition individual-level network modularity nestedness population niche width

Wear dependent virtual flow rate sensor for progressing cavity pumps with deformable stator

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Petroleum Science 2024年第2期21卷 1346-1353页

作者： jens müller Sebastian Leonow Johannes Schulz Christian Hansen martin monnigmann Ruhr-Universitat Bochum Universit atsstraûe 150Bochum44801Germany SEEPEX GmbH Scharnh olzstraûe 344Bottrop46240Germany

This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this material loss on the volumetric efficiency. The results are combined with an established backflow model to implement a backflow calculation procedure that is adaptive to wear. We use a laboratory test setup with a highly abrasive fluid and operate a pump from new to worn condition to validate our approach. The obtained measurement data show that the presented virtual sensor is capable of calculating the flow rate of a pump being subject to wear during its regular operation.

关键词： Backflow Progressing cavity pump Virtual sensor Wear

Developing fertility control for rodents: a framework for researchers and practitioners

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Integrative Zoology 2024年第1期19卷 87-107页

作者： Giovanna mASSEI jens JACOB Lyn A.HINDS Botstiber Institute for Wildlife Fertility Control Department of Environment and GeographyUniversity of YorkHeslingtonYorkUK Rodent Research Institute for Epidemiology and Pathogen DiagnosticsJulius Kühn–Institute(JKI)Federal Research Institute for Cultivated PlantsMünsterGermany CSIRO Health and Biosecurity CanberraACTAustralia

Fertility control is often heralded as a humane and effective technique for management of overabundant wildlife,including rodents.The intention is to reduce the use of lethal and inhumane methods,increase farm productivity and food security as well as reduce disease transmission,particularly of zoonoses.We developed a framework to guide researchers and stakeholders planning to assess the effectiveness of a potential contraceptive agent for a particular species.Our guidelines describe the overarching research questions which must be sequentially addressed to ensure adequate data are collected so that a contraceptive can be registered for use in broad-scale rodent management.The framework indicates that studies should be undertaken iteratively and,at times,in parallel,with initial research being conducted on(1)laboratory-based captive assessments of contraceptive effects in individuals;(2)simulation of contraceptive delivery using bait markers and/or surgical sterilization of different proportions of afield-based or enclosure population to determine how population dynamics are affected;(3)development of mathematical models which predict the outcomes of different fertility control scenarios;and(4)implementation of large-scale,replicated trials to validate contraceptive efficacy under various management-scalefield situations.In some circumstances,fertility control may be most effective when integrated with other methods(e.***.some culling).Assessment of non-target effects,direct and indirect,and the environmental fate of the contraceptive must also be determined.Developing fertility control for a species is a resource-intensive commitment but will likely be less costly than the ongoing environmental and economic impacts by rodents and rodenticides in many contexts.

关键词： captive studies field applications modeling oral contraceptive delivery population management rodents

metabolic collaboration between cells in the tumor microenvironment has a negligible effect on tumor growth

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The Innovation 2024年第2期5卷 107-114页

作者： Johan Gustafsson Fariba Roshanzamir Anders Hagnestål Sagar m.Patel Oseeyi I.Daudu Donald F.Becker Jonathan L.Robinson jens Nielsen Department of Life Sciences Chalmers University of TechnologySE-41296 GothenburgSweden Hagnesia AB SE-43854 HindåsSweden Department of Biochemistry and Redox Biology Center University of Nebraska-LincolnLincolnNE 68588USA BioInnovation Institute DK2200 CopenhagenDenmark

The tumor microenvironment is composed of a complex mixture of different cell types interacting under conditions of nutrient deprivation,but the metabolism therein is not fully understood due to difficulties in measuring metabolic fluxes and exchange of metabolites between different cell types in vivo.Genome-scale metabolic modeling enables estimation of such exchange fluxes as well as an opportunity to gain insight into the metabolic behavior of individual cell types.Here,we estimated the availability of nutrients and oxygen within the tumor microenvironment using concentration measurements from blood together with a metabolite diffusion model.In addition,we developed an approach to efficiently apply enzyme usage constraints in a comprehensive metabolic model of human cells.The combined modeling reproduced severe hypoxic conditions and the Warburg effect,and we found that limitations in enzymatic capacity contribute to cancer cells’preferential use of glutamine as a substrate to the citric acid cycle.Furthermore,we investigated the common hypothesis that some stromal cells are exploited by cancer cells to produce metabolites useful for the cancer cells.We identified over 200 potential metabolites that could support collaboration between cancer cells and cancer-associated fibroblasts,but when limiting to metabolites previously identified to participate in such collaboration,no growth advantage was observed.Our work highlights the importance of enzymatic capacity limitations for cell behaviors and exemplifies the utility of enzyme-constrained models for accurate prediction of metabolism in cells and tumor microenvironments.

关键词： metabolism effect limitations

Small mammal community composition impacts bank vole (Clethrionomys glareolus) population dynamics and associated seroprevalence of Puumala orthohantavirus

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Integrative Zoology 2024年第1期19卷 52-65页

作者： Felicitas maria BUJNOCH Daniela REIL Stephan DREWES Ulrike mROSENFELD Rainer G.ULRICH jens JACOB Christian ImHOLT Julius Kühn-Institute Federal Research Centre for Cultivated PlantsInstitute for Epidemiology and Pathogen DiagnosticsRodent ResearchMünsterGermany University of münster Institute for Evolution and BiodiversityMünsterGermany Friedrich-Loeffler-Institut Federal Research Institute for Animal HealthInstitute of Novel and Emerging Infectious DiseasesGreifswald-Insel RiemsGermany

Rodents are important reservoirs for zoonotic pathogens that cause diseases in humans.Biodiversity is hypoth-esized to be closely related to pathogen prevalence through multiple direct and indirect pathways.For example,the presence of non-host species can reduce contact rates of the main reservoir host and thus reduce the risk of transmission(“dilution effect”).In addition,an overlap in ecological niches between two species could lead to increased interspecific competition,potentially limiting host densities and reducing density-dependent pathogen transmission processes.In this study,we investigated the relative impact of population-level regulation of direct and indirect drivers of the prevalence of Puumala orthohantavirus(PUUV)in bank voles(Clethrionomys glareolus)during years with high abundance.We compiled data on small mammal community composition from four regions in Germany between 2010 and 2013.Structural equation modeling revealed a strong seasonality in PUUV control mechanisms in bank voles.The abundance of shrews tended to have a negative relationship with host abundance,and host abundance positively influenced PUUV seroprevalence,while at the same time increasing the abundance of competing non-hosts like the wood mouse(Apodemus sylvaticus)and the yellow-neckedfield mouse(Apodemusflavicollis)were associated with reduced PUUV seroprevalence in the host.These results indicate that for PUUV in bank voles,dilution is associated with increased interspecific competition.Anthropogenic pressures leading to the decline of Apodemus spp.in a specific habitat could lead to the amplification of mechanisms promoting PUUV transmission within the host populations.

关键词： bank vole biodiversity Puumala orthohantavirus small mammals

Small size does not restrain frugivory and seed dispersal across the evolutionary radiation of Galapagos lava lizards

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Current Zoology 2019年第4期65卷 353-361页

作者： Sandra HERVIAS-PAREJO Ruben HELENO Beatriz RUmEU Beatriz GUZmAN Pablo VARGAS jens m. olesen Anna TRAVESET Carlos VERA Edgar BENAVIDES manuel NOGALES Institut mediterrani d'Estudis Avanqats (CSIC-UIB) Global Change Research Group Mallorca Balearic Islands Spain Centre for Functional Ecology Department of Life Sciences University of Coimbra Portugal Real Jardin Botanico (CSIC-RJB) Madrid Spain Department of Bioscience Aarhus University Denmark Galapagos National Park Puerto Ayora Santa Cruz Galapagos Ecuador Department of Ecology and Evolutionary Biology Yale University USA lnstituto de Productos Naturales Agrobiologia (CSIC-IPNA) Island Ecology and Evolution Research Group Canary Islands Spain

Frugivory in lizards is often assumed to be constrained by body size;only large individuals are considered capable of consuming fruits, with the potential of acting as seed dispersers. However, only one previous study has tested the correlation of frugivory with body and head size at an archipelago scale across closely related species. All nine lava lizards (microlophus spp.) were studied on the eleven largest Galapagos islands from 2010 to 2016 to investigate whether frugivory is related to body and head size. We also tested whether fruit abunda nee in flue nces fruit con sumption and explored the effect of seed ingestion on seedling emergence time and percentage. Our results showed that across islands, lava lizards varied considerably in size (64-102 mm in mean snoutvent length) and level of frugivory (1-23%, i.e., percentage of droppings with seeds). However, level of frugivory was only weakly affected by size as fruit consumption was also common among small lizards. Lava lizards consumed fruits throughout the year and factors other than fruit abundance may be more importa nt drivers of fruit selecti on (e.g., fruit size, energy con tent of pulp). From 2,530 droppings, 1,714 seeds of at least 61 plant species were identified, 76% of the species being native to the Galapagos. most seeds (91%) showed no external structural damage. Seedling emergence time (44 versus 118 days) and percentage (20% versus 12%) were enhanced for lizardingested seeds compared to control (uningested) fruits. De-pulping by lizards (i.e., removal of pulp with potential germi nation inhibitors) might in crease the chances that at least some seeds find suitable recruitment conditi ons. We con eluded that lizards are importa nt seed dispersers throughout the year and across the whole archipelago, regardless of body size.

关键词： microlophus oceanic islands plant-animal interactions seed disperser size seed dispersal effectiveness seedling emergence

Fully integrated and broadband Si-rich silicon nitride wavelength converter based on Bragg scattering intermodal four-wave mixing

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Photonics Research 2024年第3期12卷 I0001-I0010页

作者： VALERIO VITALI THALÍA DOmÍNGUEZ BUCIO HAO LIU JOSÉmANUEL LUQUE GONZÁLEZ FRANCISCO JURADO-ROmERO ALEJANDRO ORTEGA-mOÑUX GLENN CHURCHILL JAmES C.GATES JAmES HILLIER NIKOLAOS KALFAGIANNIS DANIELE mELATI jens H.SCHmID ILARIA CRISTIANI PAVEL CHEBEN J.GONZALO WANGÜEmERT-PÉREZ ÑIGO mOLINA-FERNÁNDEZ FREDERIC GARDES COSImO LACAVA PERIKLIS PETROPOULOS Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK 2ElectricalComputer and Biomedical Engineering DepartmentUniversity of PaviaPavia 27100Italy 3Telecommunication Research Institute(TELMA)Universidad de MálagaCEI Andalucı´a TECHE.T.S.I.Telecomunicación29010 MálagaSpain 4School of Science and TechnologyNottingham Trent UniversityNottingham NG118NSUK 5Department of Electrical EngineeringEindhoven University of TechnologyEindhoven 5600 MBThe Netherlands 6Department of Materials Science and EngineeringUniversity of IoanninaIoannina 45110Greece 7Centre de Nanosciences et de NanotechnologiesUniversitéParis-SaclayCNRS91120 PalaiseauFrance 8Advanced Electronics and Photonics Research CenterNational Research Council CanadaOttawaOntario K1A 0R6Canada

Intermodal four-wave mixing(FWm)processes have recently attracted significant interest for all-optical signal processing applications thanks to the possibility to control the propagation properties of waves exciting distinct spatial modes of the same waveguide.This allows,in principle,to place signals in different spectral regions and satisfy the phase matching condition over considerably larger bandwidths compared to intramodal processes.However,the demonstrations reported so far have shown a limited bandwidth and suffered from the lack of on-chip components designed for broadband manipulation of different modes.We demonstrate here a silicon-rich silicon nitride wavelength converter based on Bragg scattering intermodal FWm,which integrates mode conversion,multiplexing and de-multiplexing functionalities on-chip.The system enables wavelength conversion between pump waves and a signal located in different telecommunication bands(separated by 60 nm)with a 3 dB bandwidth exceeding 70 nm,which represents,to our knowledge,the widest bandwidth ever achieved in an intermodal FWm-based system.

关键词： scattering pump modal

Characterization of ultrafine particles from hardfacing coated brake rotors

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Friction 2023年第1期11卷 125-140页

作者： Yezhe LYU Ankur SINHA Ulf OLOFSSON Stefano GIALANELLA jens WAHLSTRÖm Department of mechanical Engineering Sciences Lund UniversityLund SE-22100Sweden Department of machine Design KTH Royal Institute of TechnologyStockholm SE-10044Sweden Department of Industrial Engineering University of TrentoTrento 38123Italy

Automotive brake rotors are commonly made from gray cast iron(GCI).During usage,brake rotors are gradually worn off and periodically replaced.Currently,replaced brake rotors are mostly remelted to produce brand-new cast iron products,resulting in a relatively high energy consumption and carbon footprint into the environment.In addition,automotive brakes emit airborne particles.Some of the emitted particles are categorized as ultrafine,which are sized below 100 nm,leading to a series of health and environmental impacts.In this study,two surface treatment techniques are applied,ie.,high-velocity oxygen fuel(HVOF)and laser cladding(LC),to overlay wear-resistant coatings on conventional GCI brake rotors in order to refurbish the replaced GCI brake rotor and to avoid the remelting procedure.The two coating materials are evaluated in terms of their coefficient of friction(CoF),wear,and ultrafine particle emissions,by comparing them with a typical GCI brake rotor.The results show that the CoF of the HVOF disc is higher than those of the GCI and LC discs.meanwhile,HVOF disc has the lowest wear rate but results in the highest wear rate on the mating brake pad material.The LC disc yields a similar wear rate as the GCI disc.The ultrafine particles from the GCI and LC discs appeared primarily in round,chunky,and flake shapes.The HVOF disc emits unique needle-shaped particles.In the ultrafine particle range,the GCI and HVOF discs generate particles that are primarily below 100 nm in the running-in period and 200 nm in the steady state.meanwhile,the LC disc emitted particles that are primarily~200 nm in the entire test run.

关键词： ultrafine particle high-velocity oxygen fuel laser cladding brake particle size distribution particle morphology

Potential role of lava lizards as pollinators across the Galápagos Islands

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Integrative Zoology 2020年第2期15卷 144-148页

作者： Sandra HERVÍAS-PAREJO manuel NOGALES Beatriz GUZmÁN maría del mar TRIGO jens molesen Pablo VARGAS Ruben HELENO Anna TRAVESET Global Change Research Group Mediterranean Institute for Advanced StudiesMallorcaBalearic IslandsSpain Island Ecology and Evolution Research Group Institute of Natural Products and AgrobiologyCanary IslandsSpain Royal Botanical Garden of madrid MadridSpain Department of Plant Biology Málaga UniversityMálagaSpain Department of Bioscience Aarhus UniversityAarhusDenmark Centre for Functional Ecology Department of Life SciencesUniversity of CoimbraCoimbraPortugal

Lizards have been reported as important pollinators on several oceanic islands.Here we evaluate the potential role of Galápagos lava lizards(microlophus spp.)as pollinators across their radiation.Over 3 years,we sampled pollen transport by 9 lava lizard species on the 10 islands where they are present,including 7 single-island endemics.Overall,only 25 of 296 individuals sampled(8.4%)transported pollen of 10 plant species,the most common being Prosopis juliflora,Exodeconus miersii,Sesuvium sp.and Cordia leucophlyctis.At least 8 of these plant species were native,and none were confirmed as introduced to the archipelago.Despite the low overall proportion of individuals carrying pollen,this was observed in 7 of the nine lizard species,and on 8 of the ten main islands(Española,Fernandina,Floreana,Isabela,marchena,Pinta,Santa Cruz and Santiago),suggesting that this is a widespread interaction.The results reported here support the potential role of lava lizards as pollinators across their radiation,although they may represent a relatively modest contribution when compared with birds and insects.However,we cannot discard that lizards may be ecologically significant for particular plant species and ecosystems given the specific climatic condition and functional diversity of each island.

关键词： flower visitation microlophus spp. mutualistic interactions pollination vertebrate radiation