检索结果-南通市图书馆

Psychophysics of the hoverfly: categorical or continuous color discrimination?

Current Zoology 2019年第4期65卷 483-492页

作者： Lea Hannah Adrian G. Dyer jair.e. garcia Alan Dorin Martin Burd School of Biological Sciences Monash University Clayton Victoria 3800 Australia Hawkesbury Institute for the environment Western Sydney University Richmond New South Wales 2753 Australia School of Media and Communication RMIT University Melbourne Victoria 3001 Australia Department of Physiology Monash University Clayton Victoria 3800 Australia Faculty of Information Technology Monash University Clayton Victoria 3800 Australia

There is increasing interest in flies as potentially important pollinators. Flies are known to have a complex visual system, in eluding 4 spectral classes of photoreceptors that con tribute to the perception of color. Our current understanding of how color signals are perceived by flies is based on data for the blowfly Lucilia sp., which after being conditi oned to rewarded mono chromatic light stimuli, showed evidenee of a categorical color visual system. The resulting opponent fly color space has 4 distinct categories, and has been used to interpret how some fly pollinators may perceive flower colors. However, formal proof that flower flies (Syrphidae) only use a simple, categorical color process remains outstanding. In free-flying experiments, we tested the hoverfly eristalis tenax, a Batesian mimic of the honeybee, that receives its nutrition by visiting flowers. Using a range of broadband similar-dissimilar color stimuli previously used to test color perception in pollinating hymenopteran species, we evaluated if there are steep changes in behavioral choices with continuously increasing color differences as might be expected by categorical color processing. Our data revealed that color choices by the hoverfly are mediated by a continuous monotonic function. Thus, these flies did not use a categorical processing, but showed evidenee of a color discrimination function similar to that observed in several bee species. We therefore empirically provide data for the minimum color distanee that can be discriminated by hoverflies in fly color space, enabling an improved un derstandi ng of plant-poll in ator interactions with a non-model insect species.

关键词： chromatic signal color model floral color fly pollination plant-pollinator vision

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Signal or cue: the role of structural colors in flower pollination

引用

Current Zoology 2019年第4期65卷 467-481页

作者： jair.e. garcia Mani Shrestha Scarlett R. Howard Phred Petersen Adrian G. Dyer School of Media and Communication RMIT University Melbourne Victoria 3001 Australia Faculty of Information Technology Monash University Clayton Victoria 3800 Australia

Angle dependent colors, such as iridescenee, are produced by structures present on flower petals changing their visual appearanee. These colors have been proposed to act as signals for plantinsect communication. However, there is a paucity of behavioral data to allow for interpretations of how to classify these colors either as a signal or a cue when con sidering the n atural con ditions under which pollination occurs. We sampled flowers from 6 plant species across various viewpoints looking for changes in the visual appearanee of the petals. Spectral characteristics were measured with different instruments to simulate both the spectral and spatial characteristics of honeybee's vision. We show the presenee of color patches produced by angle dependent effects on the petals and the calyx of various species;however, the appearance of the angle dependent color patches significantly varies with viewpoint and would only be resolved by the insect eye at close distances. Behavior experiments with honeybees revealed that pollinators did not use angle dependent colors to drive behavior when presented with novel flower presentations. Results show that angle dependent colors do not comply with the requirements of a signal for plant-pollinator communication since the information transmitted by these colors would be unreliable for potential, free-flying pollination vectors. We thus classify angle dependent colors produced by micro- and ultra-structures as being a cue (a feature which has not evolved for communication), and observe no evidence supporting claims of these angle dependent colors having evolved as visual signal.

关键词： approach angle color flower iridescence photography pollination vision

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Honeybees prefer novel insect-pollinated flower shapes over bird-pollinated flower shapes

引用

Current Zoology 2019年第4期65卷 457-465页

作者： Scarlett R. Howard Mani Shrestha Juergen Schramme jair.e. garcia Aurore AvARGUeS-WeBeR Andrew D. Greentree Adrian G. DYeR Bio-inspired Digital Sensing (BIDS) Lab School of Media and Communication RMIT University Melbourne Victoria 3000 Australia Faculty of Information Technology Monash University Melbourne Victoria 3800 Australia institute of Developmental Biology and Neurobiology (iDn) Johannes Gutenberg University Mainz 55122 Germany Centre de Recherches sur la Cognition Animale Centre de Biologie Integrative (CBI) Universite de Toulouse CNRS UPS Toulouse 31400 France ARC Centre of excellence for Nanoscale BioPhotonics School of Science RMIT University Melbourne Victoria 3000 Australia Department of Physiology Monash University Clayton Victoria 3800 Australia

Plant-pollinator in teractio ns have a fundame ntal in fluence on flower evolution. Flower color signals are frequently tuned to the visual capabilities of important pollinators such as either bees or birds, but far less is known about whether flower shape in fluences the choices of pollinators. We tested european honeybee Apis mellifera pref ere nces using novel achromatic (gray-scale) images of 12 insect-pollinated and 12 bird-pollinated native Australian flowers in Germany;thus, avoiding in flue nces of color, odor, or prior experie nee. In depende nt bees were tested with a number of parameterized images specifically desig ned to assess pref ere nces for size, shape, brightness, or the number of flower-like shapes prese nt in an image. We show that honeybees have a pref ere nee for visiti ng images of in sect-polli nated flowers and such a pref ere nee is most-likely mediated by holistic in formati on rather than by in dividual image parameters. Our results in dicate an giosperms have evolved flower shapes which in fluence the choice behavior of importa nt pollinators, and thus suggest spatial achromatic flower properties are an important part of visual signaling for plantpollinator in teractions.

关键词： angiosperm Apis mellifera (european honeybee) bird-pollinated flower insect-pollinated pollinator

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Flying in Complex environments: Can Insects Bind Multiple Sensory Perceptions and What Could Be the Lessons for Machine Vision?

引用

Journal of Software engineering and Applications 2014年第5期7卷 406-412页

作者： Adrian G. Dyer Sridhar Ravi jair.e. garcia Department of Organismic and evolutionary Biology Harvard University Ambridge USA School of Media and Communication RMIT University Melbourne Australia

The possibility of having flying machines in complex natural environments presents many exciting possibilities, but also technical challenges. Insects often rely on visual cues for flight and decision making, and recent work suggests that the perception of wind force through tactile sensory inputs also provides important information for flight control. However, the extent to which these respective cues might potentially be bound together in the brain to enable accurate decisions remains untested. Here we discuss recent evidence that the brain of insects possesses mechanisms that may allow for the binding of complex multisensory information, and we propose an experiment that could dissect whether insects like bees may have such a capacity. We additionally discuss areas of the bee brain that might facilitate decision making in order to provide a road map forward for future work on understanding the mechanisms of flying in complex natural environments.

关键词： Wind Decision-Making UAV Brain Perception Color

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microstructural Morphologies and experimental Growth Laws during Solidification of Monotectic and Hypermonotectic Al-Pb Alloys

引用

Journal of Materials Science & Technology 2014年第4期30卷 401-407页

作者： Adrina P.Silva Amauri garcia José e.Spinelli Department of Materials engineering University of Campinas-UNICAMP Department of Materials engineering Federal University of Sao Carlos-UFSCar

AI-Pb alloys with monotectic and hypermonotectic compositions were directionally solidified under unsteady- state heat flow conditions. The cooling curves recorded during solidification allowed solidification thermal parameters such as the cooling rate （T）, growth rate （v） and thermal gradient （G） to be experimentally determined. Different microstructural patterns have been associated with the alloy solute content, i.e., AI-1.2 and 2.1 wt% Pb. A sequence of morphologies from the bottom to the top of the A1-1.2 wt% Pb alloy casting （monotectic） can be observed： Pb-rich droplets in the aluminum-rich matrix, followed by a region of microstructural transition formed by droplets and fibers and finally by a mixture of fibers and strings of pearls. A completely fibrous structure （without transition） has been observed along the entire AI-2.1 wt% Pb alloy casting （hypermonotectic）. The interphase spacing （λ） was measured along the casting length, and experimental correlations between λand experimental solidification thermal parameters have been established. Power laws with a -2.2 exponent expressing λ as a function of the growth rate, v, were found to better represent the fibrous growth of both AI-Pb alloys. Moreover, a single experimental law expressing λ as a function of both G and v was found to describe the fibrous growth of both the monotectic and the hypermonotectic alloys experimentally examined.

关键词： Aluminum alloys Casting Phase transformation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An investigation of soil erosion and redistribution in a Mediterranean lowland agricultural catchment using caesium-137

引用

International Journal of Sediment Research 2010年第1期25卷 1-16页

作者： Joan eSTRANY Celso garcia Desmond e. WALLING Department of earth Sciences University of the Balearic Islands Department of Geography University of ExeterAmory Building

This study sought to contribute to an improved understanding of soil erosion and redistribution on Mediterranean agricultural land, where traditional soil conservation practices have been applied over millennia to provide effective protection of cultivated land. The study was undertaken in the Na Borges catchment, a groundwater-dominated lowland limestone basin (319 km2), located in the northeastern part of Mallorca, Spain. The average sediment yield from the basin, based on river sediment load data, is e 137Cs technique was used to quantify soil redistribution rates over the past 40 years and to identify the key factors involved in soil erosion and redistribution processes. To estimate erosion and deposition rates and to elucidate the main factors affecting soil redistribution, samples were collected from six slope transects representative of the local land use and slope gradients and the presence or absence of soil conservation practices. A mass balance and a profile distribution conversion model were used for cultivated areas and areas of natural vegetation, respectively, to derive point estimates of the soil redistribution rates from the 137Cs inventories measured for individual soil bulk cores. In areas without soil conservation practices, the estimated mean soil erosion rates ranged from 12.7 to 26.4 t/ha·yr, which correspond to the slight and moderate erosion classes. The erosivity of Mediterranean climatic conditions combined with the influence of agricultural practices and slope gradient on soil erosion, represent the main factors responsible for the variation of soil losses documented for the cultivated land located in downslope areas, in the absence of soil conservation practices. Deposition dominated for those transects affected by soil conservation practices, with rates ranging between 18.8 and 96.6 t/ha·yr. However, this situation does not mean that soil conservation measures retain all the sediment, but rather that agriculture and urba

关键词： Soil erosion 137Cs Traditional soil conservation practices Agricultural land Mediterranean

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

effects of porosity,dry unit weight,cement content and void/cement ratio on unconfined compressive strength of roof tile waste-silty soil mixtures

引用

Journal of Rock Mechanics and Geotechnical engineering 2019年第2期11卷 369-378页

作者： eclesielter Batista Moreira jair Arrieta Baldovino Juliana Lundgren Rose Ronaldo Luis dos Santos Izzo Department of Civil Construction Federal University of Technology e ParanaCampus Curitiba

One of the conventional ways to improve the mechanical behavior of soils is to mix them with cementing agents such as cement, lime and fly ash. Recently, introduction to alternative materials or sub-products that can be adopted to improve the soil strength is of paramount importance. Therefore, the present study aims to investigate the effects of porosity(h), dry unit weight(gd) of molding, cement content(C)and porosity/volumetric cement content ratio(h/Civ) or void/cement ratio on the unconfined compressive strength(quor UCS) of silty soileroof tile waste(RT) mixtures. Soil samples are molded into four different dry unit weights(i.e. 13 kN/m^3, 13.67 kN/m^3, 14.33 kN/m^3 and 15 kN/m^3) using 3%, 6% and 9%cement and 5%, 15% and 30% RT. The results show that with the addition of cement, the strength of the RT esoil mixtures increases in a linear manner. On the other hand, the addition of RT decreases quof the samples at a constant percentage of cement, and the decrease in porosity can increase qu. A dosage equation is derived from the experimental data using the porosity/volumetric cement content ratio(h/C_(iv)) where the control variables are the moisture content, crushed tile content, cement content and porosity.

关键词： Roof tile waste (RT) Voids/cement ratio Reuse Ground improvement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

How to Make Capsules Containing Rejuvenators for Their Use in Asphalt Concrete

引用

武汉理工大学学报 2010年第17期32卷 18-21,34页

作者： garcia A SCHLANGeN e VAN De VeN M F C Faculty of Civil engineering and Geosciences Delft University of TechnologyMICROLAB2628CN DelftThe Netherlands Faculty of Civil engineering and Geosciences Road and Railway EngineeringDelft University of Technology2628CN DelftThe Netherlands

Rejuvenators are products designed to restore original properties to oxidized asphalt binders by restoring the original ratio of asphaltenes to maltenes. But,for a rejuvenator to be successful,it must penetrate the pavement surface. Besides,application of a rejuvenator will also reduce the skid resistance of the pavement. To solve this,these rejuvenators can be encapsulated and mixed in asphalt concrete. Once the stress in the capsules reaches a certain threshold,the particles break and the rejuvenator is released,giving back the original properties of the pavement. The objective of this paper is to show how these capsules behave and define the most appropriate testing methods to find their effect on asphalt concrete. For this,two different types of rejuvenators will be encapsulated and their effect on the properties of the capsules investigated. Besides,the release mechanisms of the capsules will be unravelled.

关键词： asphalt concrete rejuvenators encapsulation ageing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interactions between maternal parity and feed additives drive the composition of pig gut microbiomes in the post‑weaning period

引用

Journal of Animal Science and Biotechnology 2024年第3期15卷 1241-1257页

作者： Kayla Law eduardo Rosa Medina garcia Chad Hastad Deborah Murray Pedro e.Urriola Andres Gomez Department of Animal Science University of Minnesota1364 Eckles AvenueSaint PaulMN 55108USA New Fashion Pork 164 Industrial ParkwayJacksonMN 56143USA

Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare *** challenges disproportionately impact the offspring of primiparous sows compared to those of mul-tiparous *** is known regarding potential interactions between parity and feed additives in the post-weaning period and their effects on nursery pig ***,the objective of this study was to investigate the effects of maternal parity on sow and offspring microbiomes and the influence of sow parity on pig fecal microbi-ome and performance in response to a prebiotic *** weaning,piglets were allotted into three treat-ment groups:a standard nursery diet including pharmacological doses of Zn and Cu(Con),a group fed a commercial prebiotic only(Preb)based on an Aspergillus oryzae fermentation extract,and a group fed the same prebiotic plus Zn and Cu(Preb+ZnCu).Results Although there were no differences in vaginal microbiome composition between primiparous and mul-tiparous sows,fecal microbiome composition was different(R^(2)=0.02,P=0.03).The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared to multiparous offspring at d 0 and d 21 post-weaning(Perences in community composition observed at d 21(R^(2)=0.03,P=0.04).When analyzing the effects of maternal parity within each treatment,only the Preb diet triggered significant microbiome distinc-tions between primiparous and multiparous offspring(d 21:R^(2)=0.13,P=0.01;d 42:R^(2)=0.19,P=0.001).Composi-tional differences in pig fecal microbiomes between treatments were observed only at d 21(R^(2)=0.12,P=0.001).Pigs in the Con group gained significantly more weight throughout the nursery period when compared to those in the Preb+ZnCu *** Nursery pig gut microbiome composition was influenced by supplementation with an Aspergillus oryzae fermentation extract,with varying effects on performance

关键词： Aspergillus prebiotic Copper Feed additives Maternal Nursery pig microbiome Parity Swine microbiome Trace minerals Zinc

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Overview of power electronics technology and applications in power generation, transmission and distribution

引用

Journal of Modern Power Systems and Clean energy 2017年第4期5卷 499-514页

作者： J.M.MAZA-ORTeGA e.ACHA S.garcia A.GóMeZ-eXPóSITO Department of electrical engineering University of SevillaSevilleSpain Department of electrical energy engineering Tampere University of TechnologyTampereFinland School of electrical engineering Universidad MichoacanaMoreliaMexico

The main objective of this paper is ***, to provide an overview of the current status of the power electronics technology, one of the key actors in the upcoming smart grid paradigm enabling maximum power throughputs and near-instantaneous control of voltages and currents in all links of the power system chain. Second, to provide a bridge between the power systems and the power electronic communities, in terms of their differing appreciation of how these devices perform when connected to the power grid. Third, to discuss on the role that the power electronics technology will play in supporting the aims and objectives of future decarbonized power systems. This paper merges the equipment, control techniques and methods used in flexible alternating current transmission systems(FACTS) and high voltage direct transmission(HVDC) equipment to enable a single, coherent approach to address a specific power system problem, using ‘best of breed’ solutions bearing in mind technical, economic and environmental issues.

关键词： Flexible alternating current transmission systems(FACTS) High voltage direct transmission(HVDC) Voltage source converter(VSC) Insulated gate bipolar transistor(IGBT) Smart grids

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：