Effect of zeolites on adaptation processes in cows

The possibility of using Khotynets natural zeolites for preventing the development of oxidative stress and correcting disorders in the antioxidant system of cows when treating diseases of the reproductive system and under unfavorable housing and feeding conditions during the winter stabling period is shown.     

Cilia in nematode sensory organs

Electron microscopic studies revealed thle presenlce of true cilia in nerve processes connected with sensory organs of a nemnatodes. These structures are important in evaluating the relation between nematodes and the other aschelminths, from which they were separated partially on the basis of the supposed total absence of cilia.     

Interocular effects in prism adaptation

Monocular prism after-effects were measured in three groups of subjects each of whom had walked about wearing a 20-diopter prism, base up, over the right eye and one of the following over the left eye: a diffusing screen, 0-diopter prism, or a 20-diopter prism, base down. The performance of the third group showed that visual-motor spatial coordination in the adult is subject to at least limited interocular independence.     

Skin sensory afterglows

Brief stimulation of the upper lip with the tip of a nylon thread frequently produces an " afterglow" sensation that may persist as long as several minutes after cessation of stimulation. The duration of afterglow is increased by strong suggestion, and decreased by vibration of the skin prior to stimulation. The afterglow may be followed by a period of acute "awareness" of the area, distincty different from the stimulus and afterglow sensations. The afterglows produced by a warm stimulator applied to the back often well up into a painful sting.     

Phototaxis and sensory transduction in Euglena

The accumulation of Euglena gracilis in an illuminated region is brought about by two main mechanisms: orientation and subsequent directed movement (positive phototaxis) toward light scattered from particles in the illuminated zone; and by the trapping of cells in this region because of shock reactions experienced upon the cells encountering a sudden decrease of light intensity at the light-dark boundary (inverse photophobic responses).Phototactic orientation is mediated by inverse photophobic reactions which occur when the shadow of the stigma periodically falls upon the photoreceptor proper. Euglena also exhibits shock reactions when an already high light intensity is increased further (direct photophobic responses). The expression of both types of phobic responses depends upon stimulus intensity and adaptation of the sensory system in a seemingly complex way. A definition of the minimum components of the stimulus transduction system and a systems analytical approach to the study of input-output relationships enables one to construct an electronic analog of the cell's signal processing system that converts the photoreceptor input to commands which activate or inhibit flagellar reorientation. Computer simulation studies show that this model has considerable predictive value. It is hoped that with the approach presented in this article, a generalized model has become available for dealing with the questions of sensory transduction in aneural systems. Certainly, at this point more questions have been raised than have been answered. Where is the processing device located? Are its kinetic properties determined by electrical processes or by the rates of chemical reactions? Is the processor, and thereby the behavior of the orgamism, modulated by natural environmental parameters, and can it be modified permanently through more drastic chemical treatment of the cell? Is the system capable of permanent or transitory modification through repeated response, that is, does it exhibit phenomena analogous to learning and memory in higher organisms? These are only a few of the problems that require study in the future.     

Light adaptation in cat retinal rods

It has long been an open question whether individual rod receptors in the mammalian retina show any light adaptation. The prevailing evidence so far has suggested that these cells, unlike those in lower vertebrates, adapt little if at all. The experiments on cat rods reported here, however, indicate that this is not really true. Since the cone system in the cat retina has a fairly high light threshold, the rods also need to adapt so that they do not saturate with light before the cones fully take over vision at higher light intensities. In similar experiments, adaptation was found in rods of other mammalian species, including primates.     

Cellular adaptation to morphine in rats

The respiration of KCl-stimulated cortical slices of brain from control rats is markedly depressed by morphine, whereas the respiration of those from rats chronically dosed with morphine is unaffected. The results demonstrate an adaptation to morphine at the cellular level which is concomitant with the adaptation of the whole animal to morphine     

气候变迁对农业的冲击与调适

工业革命以来,随着大量能源和自然资源的消耗,导致大气中温室气体增加,全球暖化,海平面上升;气候变迁对人类生存环境产生了巨大的影响和冲击。本文从气候变迁与农业生产关系入手,分析了气候变迁对农业正负两面的效应,并着重分析气候变迁对农业生产面和农村经济社会的负面影响,最后从生态保育与绿色农业的发展思路出发,提出调整农业资源利用和生产方式,以应对气候变迁对农业的冲击。     

Spatial learning as an adaptation in hummingbirds

An ecological approach based on food distribution suggests that humming birds should more easily learn to visit a flower in a new location than to learn to return to a flower in a position just visited, for a food reward. Experimental results support this hypothesis as well as the general view that differences in learning within and among species represent adaptations.     

Motor control by sensory cortex

Classical studies of mammalian movement control define a prominent role for the primary motor cortex. Investigating the mouse whisker system, we found an additional and equally direct pathway for cortical motor control driven by the primary somatosensory cortex. Whereas activity in primary motor cortex directly evokes exploratory whisker protraction, primary somatosensory cortex directly drives whisker retraction, providing a rapid negative feedback signal for sensorimotor integration. Motor control by sensory cortex suggests the need to reevaluate the functional organization of cortical maps.     

Low-temperature relaxation and entropic barriers in supercooled liquids

The low-temperature relaxation dynamics of supercooled liquids are a long-standing theoretical problem of considerable interest. The vast amount of experimental data on such liquids indicates that viscosity and diffusion in supercooled liquids are non-Arrhenius over a wide range of temperatures. The non-Arrhenius temperature dependence of the relaxation time of the slow modes in glass-forming liquids is investigated in connection with the topology of the potential energy landscape in configuration space. An analogy is made between the derived dynamical equations and Cooper's formulation of the pair equation in superconductivity.     

TDCS技术在输油生产中的应用

介绍了一种集散控制集中监视输油生产的ＴＤＣＳ系统。该系统由工业控制计算机、可编程序逻辑控制器、现场仪表等组成,能对输油生产过程进行自动控制,并通过通信网将有关生产信息传输到有关部门。