检索结果-南通市图书馆

Food preferences by birds using bird-feeders in winter： a large-scale experiment

在线全文

学校读者我要写书评

暂无评论

Avian Research 2018年第2期9卷 157-162页

作者： piotr Tryjanowski Anders Pape Moiler Federico Morelli piotr Indykiewicz piotr Zduniak Lukasz Myczko Institute of Zoology Poznarn University of Life Sciences Wojska Polskiego 71C 60-62S Poznan Poland Ecologie Systematique Evolution Universite Paris-Sud CNRS AgroParisTech Universite Paris-Saclay 91405 Orsay Cedex France Department of Applied Geoinformatics and Spatial Planning Facult of Environmental Sciences Czech University of Life Sciences Prague Kamycka 129 16500 Prague 6 Czech Republic Department of Zoology and Landscaping University of Technology and Life Sciences Ks. A. Kordeckiego 20 85-225 Bydgoszcz Poland Department of Avian Biology and Ecology Faculty of Biology Adam Mickiewicz University in Poznah Umultowska 89 61-614 Poznan Poland

Background: Intentional winter bird feeding in gardens is one of the most common interactions between birds and humans. Because feeding may have both desired effects(provisioning of nutritious food for under-nourished birds) and undesired effects(favouritism of competitively superior species, transmission of disease), management of supplementary sites should be optimized from an ecological and conservation perspective. Therefore, the main aim of this study was to experimentally test winter food preferences of birds, with underlying potential influence of habitat(rural vs. urban) on realised food preferences ***: We conducted an experimental analysis of food preferences of wintering birds by provided bird-feeders in urban and rural environments across Poland. Data were collected twice during winter 2013–2014 across Poland, in total with 80 experimental ***: Sunflower seeds were the most preferred food supplement both in urban and rural habitats, significantly more exploited than any other food simultaneously available in feeders(animal fat, millet seed and dry fruits of rowanberry). However, no significant differences were recorded between urban and rural habitats in use of ***: The degree of use of a particular type of food at bird-feeders depended on the overall use of food in a bird-feeder—consumption of each of the four types of food was significantly positively correlated with that of the others, and it was positively correlated with the number of birds observed at the feeders.

关键词： Bird Food preferences Human-animal interactions Supplementary food Winter

Collagen Fibers in Crocodile Skin and Teeth:A Morphological Comparison Using Light and Scanning Electron Microscopy

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2020年第4期17卷 669-676页

作者： piotr Krzysztof Szewczyk Urszula Stachewicz Metals Engineering and Industrial Computer Science and International Centre of Electron Microscopy for Materials Science AGH University of Science and TechnologyKraków 30-059Al.Mickiewicza 30Poland

Collagen is one of the most versatile tissues of living organisms that comes in many shapes and sizes,providing functions ranging from tissue matrix through,ligament formation up to enabling mineralization in *** detailed light microscopy and Scanning Electron Microscopy(SEM)observations conducted in this study,allowed us to investigate morphology,sizes and crimp patterns of collagen fibers observed in crocodile skin and ***,the microscopy study revealed that although two completely different tissues were investigated,many similarities in their structure based on collagen fibers were *** type I is present in crocodile skin and teeth,showing the flexibility in naturally constructed tissues to obtain various *** crimp size investigation of collagen fibers confirmed experimentally the theoretical 67 nm D-periodicity expected for collagen type *** collagen in teeth provides a matrix for crystal growth and in the skin provides flexibility and is a precursor for corneous ***,these observations of the collagen in the skin and tooth structure in crocodiles play an important role in designing biomimetic materials with similar functions and properties.

关键词： crocodile skin collagen crimp fiber crocodile tooth SEM

Fluoride ions in groundwater of the Turkana County, Kenya, East Africa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2021年第6期40卷 945-960页

作者： piotr Rusiniak Klaudia Sekuła Ondra Sracek piotr Stopa Department of Hydrogeology and Engineering Geology Faculty of GeologyGeophysics and Environmental ProtectionAGH University of Science and TechnologyMickiewicza 30 Av30-059 KrakòwPoland Department of Geology Faculty of SciencePalacky University Olomouc17.listopadu 1277146 OlomoucCzech Republic

Groundwater samples were evaluated throughout Turkana County(Kenya,East Africa)while looking for drinking water *** samples showed high concentrations of fluoride with values in the range of 0.15–5.87 mg/*** 50%of the samples exceeded the WHO and Kenyan potable water standard guideline value of 1.5 mg/L for drinking water *** hydrogeochemical studies revealed that the dominant cation in water is Na^(+)and the dominant anion is HCO_(3)^(-)resulting in Na-HCO_(3) type of groundwater,followed by Ca/Mg-HCO_(3) or Na-SO_(4) and Na-Cl in a few *** modelling revealed that the groundwater is undersaturated with respect to gypsum and anhydrite,mostly undersaturated with respect to fluorite(6 samples are at equilibrium),and supersaturated or at equilibrium with respect to calcite(CaCO_(3)).Precipitation of calcite favours the dissolution of F-rich minerals in the alkaline ***,groundwater is enriched with sodium and bicarbonate,probably as a result of chemical weathering of *** groundwater can be presumably used for drinking purposes from 17 wells,but a detailed investigation of other trace element concentrations is necessary.

关键词： Africa Kenya Fluoride Groundwater Drinking water Speciation calculation

Anthropogenic noise interacts with the predation risk assessment in a free-ranging bird

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2024年第3期70卷 277-283页

作者： piotr Matyjasiak Patrycja Chacińska piotr Książka Institute of Biological Sciences Cardinal Stefan Wyszyński University in WarsawWóycickiego 1/3PL-01-815 WarsawPoland Department of Environmental Acoustics Institute of Environmental Protection—National Research InstituteKolektorska 4PL-01-692 WarsawPoland

Anthropogenic noise can affect a number of behavioral,physiological,and ecological aspects of animals from major taxonomic groups,raising serious conservation *** example,noise pollution impacts communicative behavior and perception of signals,movements and distribution,as well as predator–prey interactions,such as hunting success or predator detection and predation risk *** have carried out an experimental playback study,in which we investigated whether exposure to anthropogenic noise(sound of a tractor)distracts free-ranging barn swallows Hirundo rustica from paying attention to an approaching human“predator”(the“cognitive distraction”hypothesis),or whether noise leads to increased responsiveness to this“predator”(the“increased threat”hypothesis).The subjects were male barn swallows attending their breeding territories during the time when the females were *** found that barn swallow males initiated fight at signifcantly greater distances to the approaching human“predator”in the noise treatment than during the quiet control *** results suggest that anthropogenic noise causes increased vigilance and reactivity rather than a distraction,enabling birds to avoid the“predator”more *** further discuss the mechanism behind the increased alertness in response to noise and contrast the“increased threat”mechanism,usually tested in previous studies,with an alternative“cognitive sensitization”mechanism.

关键词： anthropogenic noise barn Swallow cognitive distraction flight initiation distance Hirundo rustica predation risk assessment

Slow and fast light in quantum-well and quantum-dot semiconductor optical amplifiers Invited Paper

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2008年第10期6卷 736-742页

作者： piotr Konrad Kondratko Akira Matsudaira Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbana IL61801USA

Slow and fast light in quantum-well （QW） and quantum-dot （QD） semiconductor optical amplifiers （SOAs） using nonlinear quantum optical effects are presented. We demonstrate electrical and optical controls of fast light using the coherent population oscillation （CPO） and four wave mixing （FWM） in the gain regime of QW SOAs. We then consider the dependence on the wavelength and modal gain of the pump in QW SOAs. To enhance the tunable photonic delay of a single QW SOA, we explore a serial cascade of multiple amplifiers. A model for the number of QW SOAs in series with variable optical attenuation is developed and matched to the experimental data. We demonstrate the scaling law and the bandwidth control by using the serial cascade of multiple QW SOAs. Experimentally, we achieve a phase change of 160^o and a scaling factor of four at 1 GHz using the cascade of four QW SOAs. Finally, we investigate CPO and FWM slow and fast light of QD SOAs. The experiment shows that the bandwidth of the time delay as a function of the modulation frequency changes in the absorption and gain regimes due to the carrier-lifetime variation. The tunable phase shift in QD SOA is compared between the ground- and first excited-state transitions with different modal gains.

关键词： SOA CPO Slow and fast light in quantum-well and quantum-dot semiconductor optical amplifiers Invited Paper FWM well

Generalized stiffness and effective mass coefficients for power-law Euler-Bernoulli beams

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2020年第1期36卷 160-175页

作者： piotr Skrzypacz Daulet Nurakhmetov Dongming Wei School of Sciences and Humanities Nazarbayev University010000Nur-SultanKazakhstan

We extend the well-known concept and results for lumped parameters used in the spring-like models for linear materials to Hollomon’s power-law *** provide the generalized stiffness and effective mass coefficients for the power-law Euler-Bernoulli beams under standard geometric and load *** particular,our mass-spring lumped parameter models reduce to the classical models when Hollomon’s law reduces to Hooke’s *** there are no known solutions to the dynamic power-law beam equations,solutions to our mass lumped models are compared to the low-order Galerkin approximations in the case of cantilever beams with circular and rectangular cross-sections.

关键词： Power-law Euler-Bernoulli beams Lumped parameter models Generalized stiffness coefficient Effective mass coefficient

Influence of seven levels of chemical/biostimulator protection on amino acid profile and yield traits in wheat

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Crop Journal 2022年第4期10卷 1198-1206页

作者： piotr Iwaniuk Rafal Konecki piotr Kaczynski Alua Rysbekova Bozena Lozowicka Institute of Plant Protection-National Research Institute Chelmonskiego 22 Street15–195 BialystokPoland Kazakh National Agrarian Research University Department of Plant ProtectionAbai Avenue 8Almaty 050010Kazakhstan

Biostimulators combined with pesticides can reduce the need for chemical crop protection to yield healthy wheat with high grain quality and nutritional *** goal of this four-year field study was an assessment of the effects of seven levels of sulfonylurea herbicide,morpholine and triazole fungicides,and humic biostimulator protection on concentrations of 20 amino acids(AAs)and on yield parameters under diverse climatic *** of pesticides and biostimulators reduced amino acid *** applied alone reduced AAs ***(herbicide+fungicide)protection or its combination with humic biostimulator were the most effective strategies for increasing yield,thousand-kernel weight,spike number,grain surface area,and wet *** dosages of fungicides showed effects on AA content and crop parameter values similar to those of the recommended dosages of fungicides and are in line with the European Commission’s “From Farm to Fork”*** biostimulators as agents supporting pesticide protection should be optimized for wheat growth stage to achieve the most desirable wheat parameters and implemented in agricultural practice.

关键词： Amino acids Biostimulators Plant protection products Wheat quality Yield

Changes in the speed of ants as a result of aggressive interactions

在线全文

学校读者我要写书评

暂无评论

Insect Science 2017年第5期24卷 842-852页

作者： piotr Slipinski Michal Zmihorski Laboratory of Social and Myrmecophilous Insects Museum and Institute of Zoology Polish Academy of Sciences Warsaw Poland Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden Institute of Nature Conservation PolishAcademy of Sciences Krakow Poland

Subordinate ant species utilize different tactics to reduce competition with the stronger, larger and more aggressive individuals of a dominant species. In our experimental study, we assessed the behavioral response of individual workers of 4 subordinate ant species during their co-occurrence with workers of a single dominant species. Contrary to most classical experiments focused on aggressive interactions, we assessed workers＇ speed as a crucial factor in the outcome of co-occurrence. Generally, there was a large intraspecific variation in the speed of the studied species--each had slow and fast individuals. Workers of all studied species moved faster just after interaction, suggesting that contact between 2 hostile workers is a stressful stimulus, generating a behavioral reaction of increasing speed. Also, the number of aggressive contacts experienced by a given individual positively affected its speed. Moreover, workers which were fast when exploring territory were also fast after interspecific interactions. The duration of aggression was significantly reduced by the speed and body size of a subordinate species worker--the more quickly a worker reacted and bigger it was, the shorter was the time of cumulative aggression. To our knowledge, this is the first study of this type to be conducted on ants and we conclude that speed is an overlooked and important characteristic of species and also individuals, therefore it should be considered as a driver of patterns of co-occurrence in ant assemblages.

关键词： hierarchy reaction response speed survival velocity

Cadmium and lead toxicity and bioaccumulation in Microcystis aeruginosa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2014年第3期8卷 427-432页

作者： piotr RZYMSKI Barbara PONIEDZIALEK Przemyslaw NIEDZIELSKI piotr TABACZEWSKI Krzysztof WIKTOROWICZ Department of Biology and Environmental Protection Poznan University of Medical Sciences Poznan 61-848 Poland Faculty of Chemistry Department of Water and Soil Analysis Adam Mickiewicz University Poznan 61-614 Poland

The growth of human population leads to intensification of agriculture and promotes, through eutrophication, development of cyanobacteria. One of the most widespread and bloom-forming species in freshwater is toxic Microcystis aeruginosa （M. aeruginosa）. Combustion of fossil fuels and metallurgical processes are the main sources of heavy metals contamination in surface water including cadmium （Cd） and lead （Pb）. The following study was conducted in order to determine the effect of 1- 20 mg. L-1 of Cd and Pb on photochemistry （using flow cytometry） and growth （based on chlorophyll concentra- tion） ofM. aeruginosa as well as to estimate levels of metal bioaccumulation. We have found that 1-10mg.L-1 of Cd and 1-5 rag. L1 of Pb induced continuous enhancement of chlorophyll fluorescence during 24 h of incubation. No significant degradation of chlorophyll was observed in these samples. At higher concentrations of 20 mg. L-1 of Cd and 10-20 mg.L-1 of Pb chlorophyll level significantly decreased and its fluorescence was quenched. M. aeruginosa demonstrated high capability of Cd and Pb bioaccumulation, proportionally to initial metal concentration. In samples with initial concentration of 20 mg. L-1 of Cd and Pb bioaccumulation of 87.3% and 90.1% was observed, respectively. Our study demonstrates that M. aeruginosa can potentially survive in highly metals polluted environments, be a primary source of toxic metals in the food chain and consequently contribute to enhanced toxicity of heavy metals to living organisms including human.

关键词： Microcystis aeruginosa heavy metals bioac-cumulation chlorophyll flow cytometry