Visual effects on alpha feedback training

Presenting an audible indication of subjects' electroencephalographic alpha activity under conditions of dim ambient illumination led to systematic increases in alpha density, while in total darkness the same procedure did not. These results support the view that feedback training can be clearly demonstrated only when factors leading to a suppression of alpha activity are present in the environment.     

Anxiety levels in dreams: relation to changes in plasma free fatty acids

Blood samples for determination of plasma free fatty acids were obtained throughout the night by means of an indwelling catheter. The first sample was drawn at the onset of rapid eye movements and a second after 15 minutes of these movements. Subjects were then awakened and asked to relate their dreams; a third sample was drawn 15 to 25 minutes later. Anxiety scores derived from 20 dreams of nine subjects had significant positive correlations with changes in free fatty acids occurring during REM sleep. No statistically significant relation was found between anxiety and the changes in free fatty acids occurring from the time just before awakening to 15 to 25 minutes later. Presumably, anxiety in dreams triggers the release of catecholamines into the circulation, and these catecholamines mobilize proportional amounts of free fatty acids from body fat.     

同伴反馈对大学英语写作焦虑及写作能力影响的实证研究

以152名大学非英语专业一年级学生为研究对象,通过实验组实行同伴反馈＋教师反馈教学模式,控制组完全采用教师反馈模式,考察同伴反馈教学模式对英语写作焦虑和写作能力的影响.结果表明：同伴反馈有利于降低学生的英语写作焦虑,其课堂教学焦虑和自信忧虑因子会因实施同伴反馈发生显著性改变,而这种显著性在构思焦虑和回避行为因子上消失;其次,同伴反馈和教师反馈一样有助于促进学生英语写作能力发展.因此,写作教学中同伴反馈应和教师反馈相结合,以降低学生写作焦虑,增强写作自主性,提高写作能力.     

Molecular and neuronal substrate for the selective attenuation of anxiety

Benzodiazepine tranquilizers are used in the treatment of anxiety disorders. To identify the molecular and neuronal target mediating the anxiolytic action of benzodiazepines, we generated and analyzed two mouse lines in which the alpha2 or alpha3 GABAA (gamma-aminobutyric acid type A) receptors, respectively, were rendered insensitive to diazepam by a knock-in point mutation. The anxiolytic action of diazepam was absent in mice with the alpha2(H101R) point mutation but present in mice with the alpha3(H126R) point mutation. These findings indicate that the anxiolytic effect of benzodiazepine drugs is mediated by alpha2 GABAA receptors, which are largely expressed in the limbic system, but not by alpha3 GABAA receptors, which predominate in the reticular activating system.     

Electrographic evidence of impaired brain function in chronically anxious patients

In a study of cerebral function by electroencephalographic techniques the following observations have been made. (i) In intact subjects, repeated stimulation with bright light causes a predictable change (alpha blocking) in the electroencephalogram, whereas repeated auditory stimulation does not. (ii) If, however, an auditory stimulus is presented repeatedly just before the visual stimulus, the sound temporarily but predictably acquires the property of the light to suppress the alpha activity. (iii) This linkage between sound and light occurs much less frequently in human subjects with known amounts of structural brain damage. (iv) A similar electrophysiological defect, implying impairment of brain function, occurs in patients showing severe anxiety during prolonged periods of difficulty in over-all adaptation.     

Inhibition of neighboring motoneurons in conscious control of single spinal motoneurons

Multiple fine-wire electrodes were implanted in the biceps brachii of five subjects, and artificial electronic feedback was provided to subjects from only one electrode. By this technique, it was shown that neighboring units progressively stop firing as subjects concentrate on activating an isolated unit. The inhibition of neighboring spinal motoneurons in the same pool further indicates that selective inhibition is an automatic part of single motor-unit training.     

生态系统反馈形成原因的分析

早已注意到生态系统中普遍存在着正、负反馈现象,然而却很少研究这两类反馈形成的原因.作者认为正反馈主要起因于现状是未来发展的主要基础,生命对于外界条件有主动的选择性,即有选择地吸收它熟悉的物质和信息,体现着经济高效的生存对策.正反馈的另外成因来自于生物成员间加大的原始协作、性状突变以及锻炼和学习.负反馈的主要成因是共同资源限制、相互干扰抑制、大量因子的自身维持代价变大以及冗余变大.文中以较大篇幅讨论现状是未来发展的主要基础和大量因子自身维持代价变大的问题.     

同伴反馈在大学英语写作教学中的功效研究

在非英语专业一年级学生英语写作教学中实施同伴反馈教学法,发现无论是被评者,还是评阅者,参与同伴评价不仅提高了他们的文章遣词造句能力,而且使文章结构更完善、内容更丰满,同时,该教学法还提高了学生自主学习的能力,减轻了教师的教学负担。要有效实施同伴反馈教学法,在实践中应注意:分组要结合个体差异,互评时间要固定,配对要考虑水平差异,要求学生修改时关注内容和形式,并尽可能地与教师反馈方式相结合。     

Direct cortical control of 3D neuroprosthetic devices

Three-dimensional (3D) movement of neuroprosthetic devices can be controlled by the activity of cortical neurons when appropriate algorithms are used to decode intended movement in real time. Previous studies assumed that neurons maintain fixed tuning properties, and the studies used subjects who were unaware of the movements predicted by their recorded units. In this study, subjects had real-time visual feedback of their brain-controlled trajectories. Cell tuning properties changed when used for brain-controlled movements. By using control algorithms that track these changes, subjects made long sequences of 3D movements using far fewer cortical units than expected. Daily practice improved movement accuracy and the directional tuning of these units.     

Bispectrum analysis of electroencephalogram signals during waking and sleeping

The degree of interaction of component waves making up a single electroencephalogram trace was strongly correlated with alpha activity, lead placement, and state of consciousness. Significant quadratic coupling of the waves was found only for awake subjects with high alpha activity. For these subjects about 50 percent of beta activity can be attributed to harmonic coupling with the alpha peak. During sleep, the degree of interaction was of borderline significance and did not follow a consistent pattern with respect to subject, frequency, state, or lead.     

Insulin secretion by anomers of d-glucose

Isolated rat islets were incubated for 5 minutes in the media containing either the alpha or beta anomer of D-glucose (2 milligrams per milliliter). The amounts of secreted insulin and changes of anomers ratio were concomitantly determined. In spite of rapid mutarotation, significantly greater stimulation of insulin secretion was observed by alpha-D-glucose as compared with beta-D-glucose.     

返乡农民创业政策及经济效益的研究

为了研究返乡农民的创业政策及创业所带来的经济收益,以2008—2014年湖南省怀化市农民创业培训班学员的创业信息反馈为材料,通过理论与实证相结合的方法进行了分析。研究认为应鼓励农民积极创业,引导他们奋发进取,创业创新,努力实现自我价值,从而有力推进社会主义新农村建设。     

半干旱地区马铃薯种植户适应气候变化行为研究——基于甘肃省362个微观调查数据

为了解甘肃省定西市马铃薯种植户适应气候变化行为及其影响因素,采用Bivariate-Probit模型,对362个马铃薯种植户主动和被动适应气候变化两种行为进行了研究,结果表明:种植户的年龄、是否参加技术培训、是否受到自然灾害、农业贷款可获得性明显促进了他们主动适应气候变化的行为,而村庄距市场距离、所在地域起负向影响;影响种植户是否采取被动适应性行为的主要因素是转移劳动力占家庭劳动力人数占比、受到自然灾害影响、获得农业贷款的可行性。就边际效应而言,农业贷款可获得性更能促进种植户适应气候变化。     

Membrane changes in a single photoreceptor cause associative learning in Hermissenda

Single type B photoreceptors in intact, restrained Hermissenda were impaled with a microelectrode and exposed to either paired or unpaired presentations of light and depolarizing current to simulate natural stimulus effects during conditioning with light and rotation. Paired, but not unpaired, stimulus presentations produced cumulative depolarization and increased input resistance in type B cells. These membrane changes are similar to those observed after pairings of light and rotation are administered to either intact animals or isolated nervous systems or when light is paired with electrical stimulation of the vestibular system in isolated nervous systems. One and two days after treatment, pairing- and light-specific suppression of phototactic behavior was observed in recovered animals. These findings indicate that the membrane changes of type B cells produced by pairing light with current injections cause acquisition of the learned behavior.     

正念训练对高水平运动员相关心理指标的影响

为了检验MAC正念训练对高水平运动员心理指标的影响，选取高水平武术运动员3名，进行每周一次 ，每次1h左右，共6周的MAC正念训练。结果表明，MAC训练通过降低高水平运动员特质性焦虑、自我意识 水平；MAC正念训练后解决问题策略和处理情绪策略使用的倾向性明显升高。     

基于趋势辨识理论的神经网络及其在水文时间序列预报中的应用

训练样本在数量级上的差别和分配的不均匀会导致网络收敛缓慢,且训练结果偏向样本比重较大的那一方。由AR模型在水文时间序列的较好应用可知,水文时间序列中趋势项占有绝对优势。因此以趋势辨识理论对样本进行规范化,使样本规范化到同一数量级,同时时间序列的趋势保持不变。此外输出层不经过非线性处理,以保证网络有更大的预报空间。经黑河流域实测流量资料验证,基于趋势辨识理论的神经网络在水文时间序列预报中训练速度较快,预报效果较好。     

Variations in alpha voltage of the electroencephalogram and time perception

Human subjects were instructed to respond regularly at 3-second intervals while their brain waves were recorded and analyzed. When subjects were alert the time between two successive responses did not vary greatly; however, as subjects became increasingly drowsy these times lengthened and the mean voltage of the peak alpha frequency decreased.     

Experimental Diabetes and Diet

In the experiments described the following observations have been made: (1) The toxic and diabetogenic action of alloxan increases in rats fed a low protein diet and even more so in the case of a high lard or ox fat diet. (2) The action of these fat diets was corrected by the addition of methionine, thiouracil, or coconut oil, but there was no modification either by addition of choline or sulfonamide or by increase in the protein proportion. (3) In rats fed other high fat diets (olive oil, butter) the actions of alloxan were not modified, but there was a slight diminution when high oleomargarine or corn oil diets were fed. However, complete protection was observed when a high coconut oil diet was administered. (4) The unfavorable effect of the high lard diet was observed also on the initiation and evolution of diabetes due to subtotal pancreatectomy. Contrarily, feeding a high protein diet and especially treatment with thiouracil had a favorable effect. (5) Diabetes appeared first in subtotal pancreatectomized rats which were overfed, then in those which ate ad libitum, and finally in those which were underfed. Diabetes appeared in rats fed a single meal before it did in those eating the same amount of food divided into three meals.     

Operant conditioning of cortical unit activity

The activity of single neurons in precentral cortex of unanesthetized monkeys (Macaca mulatta) was conditioned by reinforcing high rates of neuronal discharge with delivery of a food pellet. Auditory or visual feedback of unit firing rates was usually provided in addition to food reinforcement. After several training sessions, monkeys could increase the activity of newly isolated cells by 50 to 500 percent above rates before reinforcement.     

T cell CD3-zeta eta heterodimer expression and coupling to phosphoinositide hydrolysis

The T cell antigen receptor consists of an antigen-binding heterodimer that is noncovalently associated with at least five CD3 subunits (gamma, delta, epsilon, zeta, and eta). The CD3-zeta chains are either disulfide-linked homodimers (CD3-zeta 2) or disulfide-linked heterodimers with eta (CD3-zeta eta). Variants of a murine antigen-specific T cell hybridoma that express normal amounts of CD3-zeta 2 but decreased amounts of CD3-zeta eta were isolated. When activated, the parental cell line increased both phosphatidylinositol hydrolysis and serine-specific protein kinase activity to a much greater extent than the variants. In contrast, the activation of a tyrosine-specific kinase after stimulation with a cross-linking antibody to CD3 was similar among these cells. There was a positive linear relation between the expression of CD3-zeta eta and phosphoinositide hydrolysis stimulated by the TCR, suggesting a differential coupling of the T cell alpha beta heterodimer to signal transduction mechanisms due to alpha beta association with either CD3-zeta 2 or CD3-zeta eta.