Electroretinogram in response to x-ray stimulation

The retina of the grass frog, Rana pipiens, responds to flashes of highintensity x-rays and produces an electroretinogram indistinguishable in form from the electroretinogram produced in response to light stimulation at low and intermediate intensities. At higher intensities the form changes and, for maximal responses, the electroretinogram in response to x-rays shows a lower amplitude and a longer latent period than that in response to light. The prolonged latent period indicates additional intermediate reactions for the x-rays response.     

国内外蓝绿藻应急响应预案的比较分析

近年来,蓝绿藻暴发问题在我国水体中频频出现,各地已经出现了针对该事件的应急响应预案。澳大利亚及美国在蓝绿藻暴发事件的应急响应方面具有多年丰富的经验。以澳大利亚Coliban地区、美国弗吉尼亚州、无锡太湖、安徽巢湖的蓝绿藻暴发应急响应预案为例,分析了国内外应急响应预案的差异,并得到完善我国蓝绿藻应急响应预案的几点启示。并提出在编制蓝绿藻暴发应急响应预案时,要完善相关应急预案的内容、重视公众信息的发布、设立专项法规、加强相关科研成果在应急预案中的应用及加强应急预案的教育作用。     

Observation learning in cats

In two experiments cats acquired a stimulus-controlled approach or avoidance response by observational or conventional shaping procedures. Observer cats acquired the avoidance response (hurdle jumping in response to a buzzer stimulus) significantly faster and made fewer errors than cats that were conventionally trained. Observer cats acquired the approach response (lever pressing for food in response to a light stimulus) with significantly fewer errors than cats that were conventionally trained. In some cases, observer cats committed one or no errors while reaching criterion.     

Infant responses to impending collision: optical and real

Twenty-four infants ranging in age from 2 to 11 weeks responded to symmetrically expanding shadows, which optically specify an approaching object, with an integrated avoidance response and upset. This response did not occur for asymmetrically expanding shadows nor for contracting shadows that specify an object on a miss path and a receding object. The response was observed in all the infants regardless of age, and the addition of kinetic depth information to the displays did not increase the intensity or likelihood of the response. In a second experiment, seven infants defensively reacted to the approach of a real object except when it was on a miss path.     

Red and far-red light effects on a short-term behavioral response of a dinoflagellate

Cessation of movement (stop response) is used as a criterion for light reception by the dinoflagellate Gyrodinium dorsum Kofoid. Brief irradiation (2 seconds at 470 nanometers) elicits a stop response in cells any time during the 6-minute interval after removal from growth lights. This stop response is inactivated by exposure for 4 minutes to 470-nanometer light prior to stimulation. Red light (620 nanometers) reactivates this stop response, and far-red light (700 nanometers) reverses this reactivation. This red-far-red photo reversibility is taken as evidence for phytochrome involvement.     

盘刀式切碎器刀盘系统动态特性的试验

以盘刀式切碎器刀盘系统的动态数学模型为基础,本文分析了刀盘系统在稳态条件下对单位脉冲扭矩函数的响应。通过试验,确定了刀盘系统在工作过程中所输入的扭矩函数型式,进一步分析了刀盘系统对输入函数的响应过程,并求出了响应过程的数学模型。最后,根据系统的响应方程,分析了系统动力学参数对系统工作时响应的影响。     

Electroretinogram of the visually deprived cat

Cats kept in darkness from birth show a subnormal b-wave in the electroretinogram to 4 weeks of age but quickly develop the full response upon stimulation. When the cats are kept without light for 1 year, the response recovers slowly after intense stimulation. A 2-day exposure to light is sufficient to reverse this diminution in response.     

Carbon dioxide and climate: the importance of realistic geography in estimating the transient temperature response

Results obtained from a detailed air-sea-ice climate model for an instantaneous increase in the atmospheric carbon dioxide content are used to estimate the transient surface temperature response for several time-dependent carbon dioxide increase scenarios. The inclusion of realistic variations of land fraction and ocean mixing with latitude is found to limit the applicability of steady- state simulations as approximate guides to the actual time-dependent temperature response, particularly when the regional response is considered.     

Independence of yield potential and crop nitrogen response

Crop yield level and nitrogen (N) responsiveness influence the demand for fertilizer. If they were found to be unrelated, this would justify using a combination of both for determining fertilizer N requirements. Failure to understand the independence of crop response to N and yield level has led to confusion as to what theory is appropriate for making N fertilizer rate recommendations. The sufficiency approach applies a fixed rate of N at a computed sufficiency level, regardless of yield potential. Alternatively, mid-season optical sensor estimates of yield potential and crop response to additional N provide a physiological basis to estimate N removal and a biologically based N application rate. This study investigated the relationship between grain yield and response to N in long-term wheat and corn experiments. No relationship between response to N and grain yield was found. There was also no relationship between yield and year at two of three sites. Finally, there was no relationship between response to N and year at any site. Because yield and response to N were consistently independent of one another, and as both affect the demand for fertilizer N, estimates of both should be combined to calculate realistic in-season N rates.     

玉米产量及组成性状稳定性的遗传及相关分析

本试验由11个玉米自交系按双列式组配成55个单交组合,在三个地点试验。产量及组成性状的稳定性参数的估计按Tai的方法进行。稳定性参数的配合力分析表明:产量、穗长、百粒重、籽粒深度等组成性状的稳定性的线性反应的遗传主要受GCA所控制;在直线响应离差的表现中,GCA和SCA都同样重要。产量稳定性在相关分析中主要与百粒重、籽粒深度、穗重、穗粒重和单株穗数的稳定性反应有关,而穗长和行粒数与其它组成性状表现出一种互补关系。     

我国农业财政投入对农民收入增长效应的实证分析

为探讨财政农业投入与农民收入的关系,根据1978～2006年经济数据,利用协整理论分析了财政支农与农民收入的关系,并得到了计量回归模型,回归结果表明,支援农业生产和各项农业事业费、农业科技三项费用对增加农民收入起到有利作用,而农业基本建设支出和农村救济费阻碍了农民收入增加。然后对变量间的脉冲响应进行分析,结果表明,支持农业生产和各项农业事业费的支出变化对农民纯收入有正的冲击,并且从第2年开始冲击越来越大;农业基本建设支出和农村救济费开始反应为正,持续到将近第3年发生波动;农业科技三项费用对农民收入的脉冲响应开始为负,并持续了大约5个时期,然后才转为正的冲击。最后结合我国财政支农的一些特征,得出我国财政支农的规模、比重以及结构严重不合理的结论。     

我国粮食生产对价格及非价格因素的反应

通过建立回归方程和计算弹性系数,对我国粮食生产对价格因素和非价格因素的反应进行了研究.计算结果表明:我国粮食总供给价格弹性系数为0.73,粮食总产量对前3年财政支农支出反应的弹性系数为0.09744.表明我国粮食生产对价格因素的反应是敏感的,对非价格因素的反应不敏感.     

毛竹光响应模型适用性分析

为更好地开展毛竹Phyllostachys pubescens固碳研究,筛选适合毛竹的光响应模型的基础性研究显得十分必要。以3年生毛竹叶片2009年1月－2010年1月光合响应曲线测定资料为基础,利用非直角双曲线模型、直角双曲线模型、二次函数和指数方程4种方法,对毛竹光响应曲线进行拟合。结果表明：非直角双曲线模型与直角双曲线模型拟合的相关度最高,均大于0.95,指数方程次之,二次函数最差;但非直角双曲线模型与直角双曲线模型所求出的最大净光合速率（P_max）和暗呼吸速率（R_d）较实测值高,指数模型的拟合结果准确,但对暗呼吸速率（R_d）的拟合结果比实测值低;二次函数所拟合的光饱和点（P_LS）与暗呼吸速率（R_d）均不正确。建议计算P_LS和P_max时使用指数方程,计算表观光量子效率（Y_AQ）,光补偿点（P_LC）和R_d时使用50 ~ 100 μmol·m^－2·s^－1以下数值进行直线拟合。图1表2参22     

A substance P antagonist, [D-Pro2, D-Trp7,9]SP, inhibits inflammatory responses in the rabbit eye

Neurogenic factors released by antidromic nerve stimulation are thought to be in part responsible for the vasodilation and breakdown of the blood-aqueous barrier that follows trauma to the eye. Substance P is one candidate for the mediation of the inflammatory response since it is thought to be a neurotransmitter in sensory afferents and since exogenous substance P is capable of eliciting a response characteristic of inflammation. In rabbits, intravitreal or topical application onto the eye of a specific substance P antagonist, [d-Pro2, D-Trp7,9]SP, inhibited not only the irritant effects of exogenous substance P but also the inflammatory response to a standardized trauma (infrared irradiation of the iris). These observations suggest that substance P, or a related peptide, is a neurogenic mediator of the inflammatory response in the eye.     

昆虫滞育诱导的光周期反应类型

介绍了昆虫滞育诱导的4种光周期反应类型，即：长日照反应型、短日照反应型、短日照一长日照反应型与中间型日长反应型。根据这4种光周期反应类型显示的结果，光周期反应可能是温度补偿或温度敏感的；基于数量的时间测量或基于质量的时间测量的；极短日照或极长日照对滞育诱导的影响是不同的；诱导夏季滞育的长日照和诱导冬季滞育的短日照对滞育诱导效果是不同的。     

Giant Piezoelectric Effect in Strontium Titanate at Cryogenic Temperatures

Piezoelectric materials have many applications at cryogenic temperatures. However, the piezoelectric response below 10 kelvin is diminished, making the use of these materials somewhat marginal. Results are presented on strontium titanate (SrTiO3), which exhibits a rapidly increasing piezoelectric response with decreasing temperature below 50 kelvin; the magnitude of its response around 1 kelvin is comparable to that of the best materials at room temperature. This "giant" piezoelectric response may open the way for a broad class of applications including use in ultralow-temperature scanning microscopies and in a magnetic field-insensitive thermometer. These observations, and the possible divergence of the mechanical response to electric fields at even lower temperatures, may arise from an apparent quantum critical point at absolute zero.     

Distributed and overlapping representations of faces and objects in ventral temporal cortex

The functional architecture of the object vision pathway in the human brain was investigated using functional magnetic resonance imaging to measure patterns of response in ventral temporal cortex while subjects viewed faces, cats, five categories of man-made objects, and nonsense pictures. A distinct pattern of response was found for each stimulus category. The distinctiveness of the response to a given category was not due simply to the regions that responded maximally to that category, because the category being viewed also could be identified on the basis of the pattern of response when those regions were excluded from the analysis. Patterns of response that discriminated among all categories were found even within cortical regions that responded maximally to only one category. These results indicate that the representations of faces and objects in ventral temporal cortex are widely distributed and overlapping.     

糯玉米、优质蛋白玉米花培反应率的研究初报

用82-1培养基对14份糯玉米和10份优质蛋白玉米的花培反应率进行了离体培养研究。结果表明,14份糯玉米材料中有13份具有花培反应,占参试糯玉米材料的92.86%,其中反应率最高的是作登糯玉米(出愈率3.16%);10份优质蛋白玉米材料中有5份具有花培反应,占参试优质蛋白玉米材料的50.00%,其中反应率最高的是CML170(出愈率0.65%)。3份糯玉米材料即田东作登糯、都安良昌糯、天峨糯能产生正常绿苗,占参试糯玉米材料的21.43%,正常绿苗率分别为4.08%、9.09%、25.00%;1份优质蛋白玉米材料(CML170)产生正常绿苗,正常绿苗率占参试优质蛋白玉米材料的10.00%。试验结果还表明,糯玉米材料的出愈率以及绿苗率均比优质蛋白玉米材料高;糯玉米与优质蛋白玉米的花培反应同普通玉米一样存在基因型依赖性。     

Central and peripheral control of gill movements in Aplysia

Two types of gill contraction in Aplysia were used to study the relation of peripheral and central pathways in controlling behavioral responses in a mollusk. A weak or moderate tactile stimulus to the mantle elicits gill contraction (gill-withdrawal reflex) as a component of a more extensive withdrawal response; a stimulus applied directly to the gill elicits a localized response of the gill pinnule (pinnule response). Central pathways through the abdominal ganglion are both necessary and sufficient for the gill-withdrawal reflex, and motor neuron L7 makes direct connections with gill muscles, without engaging the peripheral plexus. Peripheral pathways are necessary and sufficient for the pinnule response. As a result of the independence of peripheral and central pathways, habituation by repeated tactile stimulation of one pathway does not affect the responsiveness of the other pathway.