Visual adaptation to gradual change of intensity

The eye can adapt to the rate of change of brightness. After exposure of the eye to a light that grows gradually brighter, a steady light appears to grow gradually dimmer, and vice versa. A field containing shading gives larger after effects than a spatially uniform field.     

Visual cortex neurons: response to stimuli during rapid eye movements

While awake, unanesthetized monkeys held their eyes stationary, a motionless or slowly moving stimulus falling on the receptive field of striate cortex neurons produced an excitatory response. When a rapid eye movement was made across the same stimulus, many of these neurons continued to give an excitatory response. But the discharge of other neurons was unchanged or was suppressed during the eye movement.     

Energy generation for an ad hoc wireless sensor network-based monitoring system using animal head movement

The supply of energy to electronics is an imperative constraining factor to be considered during the design process of mobile ad hoc wireless sensor networks (MANETs). This influence is especially important when the MANET is deployed unattended or the wireless modules within the MANET are not easily accessible. Therefore, exploring novel sources of energy generation rather than operating electronics only on limited power supplies such as batteries is a major challenge. Monitoring free-ranging animal behavior is an application in which the entities (animals) within the MANET are not readily accessible; however, animal movement can be potentially used to generate energy. In this study, the head movements of individual sheep in a flock during grazing were monitored in order to investigate the amount of energy that can be generated by these movements. By applying the Lagrange-d’Alembert Principle to this problem, the equations of motion from each neck-mounted sensor as well as the amount of mechanical energy generated per time instant (each second) during upward and downward head movements were calculated. This resulted in the production of 857 mW and 1660 mW during the downward and upward movements, respectively. Furthermore, the energy consumption of each wireless node within the MANET was estimated to be 117.8 mW per second. Conversion of energy from mechanical to electrical requires miniature electromechanical generators that can currently provide between 25% and 50% conversion efficiency. Even using the worst conversion efficiency (25%), a minimum of 214 ± 25 mW of electrical energy per second could be generated. This amount exceeds the energy consumed by the wireless sensors that can be used to gather parameters describing animal behavior such as neck and head movement. This study suggests that the amount of energy generated by the vertical neck-head movement of sheep during grazing can be converted to useful electrical power adequate to provide power for operation of wireless sensor nodes on a continuous basis within a MANET-based animal behavior monitoring system.     

Gating of retinal transmission by afferent eye position and movement signals

Vision in most vertebrates is an active process that requires the brain to combine retinal signals with information about eye movement. Eye movement information may feed forward from the motor control areas of the brain or feed back from the extrinsic eye muscles. Feedback signals elicited by passive eye movement selectively gate retinal outflow at the first relay, the dorsal lateral geniculate nucleus. The gating predominantly facilitates retinogeniculate transmission immediately after eye movement and inhibits transmission when a new steady-state eye position is achieved. These two gating effects are distributed in a complementary fashion across the dorsal lateral geniculate nucleus such that the spatiotemporal activity profile could contribute to object detection and localization.     

大麦赤霉病抗扩展性及其与农艺性状相关性评价

采用单花滴注法将禾谷镰刀菌(Fusarium graminearum)分生孢子接种103份大麦品种（系）,鉴定分析不同的大麦品种（系）对赤霉病菌的抗扩展性及其与农艺性状的相关性。结果表明,不同的基因型品种(系)之间抗赤霉病菌扩展性存在显著差异,可划分为高抗（病穗率0～10%）、中抗（病穗率10%～20%）、中感（病穗率20%～40%）和高感（病穗率40%～100%）;大麦抗赤霉病菌扩展性与抽穗期、株高呈显著的负相关,二棱大麦抗扩展性显著高于多棱大麦;供试材料中抗扩展性品种（系）较少,占总数的31.1%, 筛选到10个高抗扩展性的品种（系）,分别为：‘Sterling’、‘Metcalfe’、‘Parkhill’、‘ACCA’、‘ND14048’、‘玉环猪尾巴’、‘江山二棱麦’、 ‘黄岩野大麦’、 ‘乐清扁大麦’,、‘上虞红大麦’。     

糜子感染黑穗病菌后的生理变化及与抗病性关系

为明确糜子对黑穗病的抗性生理机制,在大田条件下,以不同抗性水平的10个糜子品种为材料,采用种子饱和接种法人工接种黑粉菌,测定了三叶期不同糜子品种叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、β-1,3-葡聚糖酶、几丁质酶活性以及丙二醛(MDA)含量。结果表明,人工接种黑粉菌后不同抗性水平糜子品种叶片SOD、β-1,3-葡聚糖酶和几丁质酶活性有所提高,最大增幅分别达92%、16%和31%;MDA含量有所增加,最大增幅达20%;POD活性呈不同变化。人工接种条件下抗性水平较高品种的保护酶系统酶活性以及病程相关蛋白活性提升幅度较大,MDA含量增加幅度较小。各生理指标与抗病性的相关分析表明,SOD、POD、β-1,3-葡聚糖酶以及几丁质酶活性与发病率呈极显著负相关,相关系数分别为0.941、0.468、0.514和0.757;MDA含量与发病率呈显著正相关,相关系数为0.378。     

结球甘蓝主要商品性状与农艺性状的遗传相关分析

以6个甘蓝亲本进行完全双列杂交,采用加性-显性遗传模型对结球甘蓝的主要商品、农艺性状进行遗传分析。结果表明:各性状的遗传同时受加性效应和显性效应的作用,株高、外叶数主要受加性效应控制;开展度、单球重、帮叶比、中心柱/球高主要受显性效应控制。相关分析表明,开展度-株高、开展度-单球重、外叶数-帮叶比等成对性状成显著正相关,利用株高可对帮叶比、中心柱/球高进行间接选择。     

Eye and head movements in peripheral vision: nature of compensatory eye movements

Simultaneous recordings of both eye and head movements in response to a peripheral signal indicated that the backward compensatory eye movement was initiated during the constant velocity of the head rotation. This compensatory movement began before the eyes had actually reached the peripheral signal.     

Visual and "phonetic" coding of movement: evidence from american sign language

Hearing subjects unfamiliar with American Sign Language and deaf native signers made triadic comparisons of movements of the hands and arms isolated from American Sign Language. Clustering and scaling of subjects' judgments revealed different psychological representations of movement form for deaf and hearing observerd. Linguistically relevant dimensions acquired modified salience for users ofa visual-gestural language. The data indicate that the modification of natural perceptual categories after language acquisition is not bound to a particular transmission modality, but rather can be a more general consequence of acquiring a formal linguistic system.     

花椰菜花球性状及植株性状的遗传相关分析

以7个花椰菜亲本进行不完全双列杂交，采用加性．显性遗传模型，对花椰菜的花球挂状及植株性状进行遗传相关分析。结果表明，多数性状间存在显著的遗传相关，有些性状问存在明显的加性相关，在花椰菜选择育种中可加以利用。     

Foraging adaptation and the relationship between food-web complexity and stability

Ecological theory suggests that complex food webs should not persist because of their inherent instability. "Real" ecosystems often support a large number of interacting species. A mathematical model shows that fluctuating short-term selection on trophic links, arising from a consumer's adaptive food choice, is a key to the long-term stability of complex communities. Without adaptive foragers, food-web complexity destabilizes community composition; whereas in their presence, complexity may enhance community persistence through facilitation of dynamical food-web reconstruction that buffers environmental fluctuations. The model predicts a linkage pattern consistent with field observations.     

Growing food,growing a movement: climate adaptation and civic agriculture in the southeastern United States

This article examines the role that civic agriculture in Georgia (US) plays in shaping attitudes, strategies, and relationships that foster both sustainability and adaptation to a changing climate. Civic agriculture is a social movement that attracts a specific type of “activist” farmer, who is linked to a strong social network that includes other farmers and consumers. Positioning farmers’ practices within a social movement broadens the understanding of adaptive capacity beyond how farmers adapt to understand why they do so. By drawing upon qualitative and quantitative data and by focusing on the cosmological, organizational, and technical dimensions of the social movement, the study illuminates how social values and networks shape production and marketing strategies that enable farmers to share resources and risks. We propose a conceptual framework for understanding how technical and social strategies aimed to address the sustainability goals of the movement also increase adaptive capacity at multiple timescales. In conclusion, we outline directions for future research, including the need for longitudinal studies that focus on consumer motivation and willingness to pay, the effects of scale on consumer loyalty and producer cooperation, and the role of a social movement in climate change adaptation. Finally, we stress that farmers’ ability to thrive in uncertain climate futures calls for transformative approaches to sustainable agriculture that support the development of strong social networks.     

土壤性质与硼有效性的关系

土壤硼的有效性受许多因素的影响 ,文章介绍了土壤 p H,土壤有机质 ,土壤水分 ,土壤温度 ,土壤质地 ,土壤无机离子 ,成土母质类型等对土壤硼有效性的影响 ,对今后的研究提出了建议。     

木质饰面胶合板的视觉物理量与视觉心理量的相关性分析

在对市场具代表性的51个不同材种饰面胶合板表面视觉物理量系统分析的基础上,抽取27个典型材种饰面胶合板,采用数字图像处理技术测量并分析得出表面材色参数,以7个视觉心理变量为基本依据,探讨木材视觉物理量与心理量之间的联系,建立木质饰面胶合板色彩情感模式,为创造更舒适、健康的生活环境以及提高生活质量提供科学依据.     

糖尿病的发生与免疫指标的相关性研究

【目的】观察在糖尿病发生过程中体液免疫与细胞免疫的相关性.【方法】通过高脂饮食来制备小鼠前期糖尿病(Pre-DM)模型,及高脂饮食联合小剂量多次注射链脲佐菌素(STZ)制备小鼠Ⅱ型糖尿病(T2DM)模型.将80只C57BL/6J试验小鼠随机分为4组:根据预试验结果,饲喂高糖高脂饮食,选取0 d(A组)、40 d(B组)、80 d的(C组),为Pre-DM组;在80 d之后用高脂饲喂联合小剂量多次注射STZ制备T2DM模型组(D组).进行空腹血糖腹腔注射糖耐量实验(IPGTT);测定相关血清生化指标,用ELISA法测定胰岛素水平及免疫指标.用比浊法作hs-CRP,应用流式细胞术检测CD_3~+、CD_3~+CD_8~+、CD_3~+CD_4~+等T淋巴细胞亚群的比例.【结果】IPGTT结果显示,D组与其他3组曲线下面积差异极显著(P0.01).A～D组血糖存在依次上升趋势,组间均有显著差异(P0.05),与糖尿病相关的生化指标组间均有差异性(P0.05),CD_3~+CD_8~+与CD_3~+CD_4~+组间差异均显著(P0.05),CD_3~+A组与D组的差异显著(P0.05),其余各组间差异不显著(P0.05).HE染色结果发现,T2DM的发生过程会伴随器官的损伤.【结论】Pre-DM模型组已经存在胰岛素抵抗与胰岛受损,且伴随着肝脏不同程度的损伤;Pre-DM模型组相关的免疫指标异常及T淋巴细胞亚群的比例失衡与T2DM的发生风险有一定的相关性.     

政党意志与革命场景的背离——以晋绥边区农业互助合作运动的偏差为例

农业互助合作运动的开展是抗日战争和解放战争时期共产党经济政策中的重要环节。这一运动曾为共产党赢得战争并最后夺取政权获取合法性权威,但其发展过程中出现政党意志与革命场景背离的问题亦不容忽视。以战时晋绥边区农业互助合作运动中出现的偏差为线索,在分析这一现象的表现、产生原因及其纠正方式的基础上,深刻反思其给予今天党员自身建设与"三农"问题的启示。