Muscle Damaging Exercise Affects Isometric Force Fluctuation as well as Intraindividual Variability of Cognitive Function

Healthy untrained men (N = 11) were asked to perform 10 series of 12 repetitions of knee eccentric extension (EE) at 160° per second. Quadriceps muscle torques evoked by electrical stimulation at 20 Hz (P20) and 100 Hz (P100), maximal voluntary isometric contraction torque (MVC), maximal isokinetic concentric torque (IT) at 30° per second, voluntary activation index (VA), simple reaction time (RTs), complex reaction time (RTc), and torque variability at 30% of MVC were measured before EE, immediately after EE, and 60 min and 24 hr after EE. MVC, IT, P20, P100, and VA decreased significantly after EE and remained depressed 24 hr later. Torque variability increased significantly after EE. Average RTs and RTc did not change after EE, whereas intraindividual variability in RTs and RTc increased significantly after EE.     

Radial bisection of words and lines in right‐brain‐damaged patients with spatial neglect

The bisection of lines positioned radially (with the two ends of the line close and far, with respect to the participant's body) has been less investigated than that of lines placed horizontally (with their two ends left and right, with respect to the body's midsagittal plane). In horizontal bisection, patients with left neglect typically show a rightward bias for both lines and words, greater with longer stimuli. As for radial bisection, available data indicate that neurologically unimpaired participants make a distal error, while results from right‐brain‐damaged patients with left spatial neglect are contradictory. We investigated the bisection of radially oriented words, with the prediction that, during bisection, linguistic material would be recoded to its canonical left‐to‐right format in reading, with the performance of neglect patients being similar to that for horizontal words. Thirteen right‐brain‐damaged patients (seven with left spatial neglect) and fourteen healthy controls were asked to manually bisect 40 radial and 40 horizontal words (5–10 letters), and 80 lines, 40 radial and 40 horizontal, of comparable length. Right‐brain‐damaged patients with spatial neglect exhibited a proximal bias in the bisection of short radial words, with the proximal part corresponding to the final right part of horizontally oriented words. This proximal error was not found in patients without neglect and healthy controls. For bisection, short radial words may be recoded to the canonical orthographic horizontal format, unveiling the impact of left neglect on radially oriented stimuli.     

Terror and Collateral Damage: Are they Permissible?*

This article begins by comparing terror and death and then focuses on whether killing combatants and noncombatants as a mere means to create terror, that is in turn a means to winning a war, is ever permissible. The role of intentions and alternative acts one might have done is examined in this regard. The second part of the article begins by criticizing a standard justification for causing collateral (side effect) deaths in war and offers an alternative justification that makes use of the idea of group liability. * This article is a shortened version of my “Failures of Just War Theory: Terror, Harm, and Justice,” Ethics 114 (July 2004), pp. 650–694, with the addition of new material on the use of terror in Section 2.     

美式反恐战略给无辜者带来的道德伤害

恐怖主义是全人类的共同敌人。在美国主导国际社会反恐话语权的宏观背景下,美式反恐战略在美国国内造就了一个放弃“美国价值”的美国;在国际社会,给无数无辜者带来了巨大的道德伤害。其对人类社会伦理秩序破坏所造成的损害尚无法评估。     

论人类个体原始DNA保存的价值

DNA的遗传和变异是人类延续和进化的本源;在外界环境影响下,DNA遗传、突变与人类疾病的产生具有密切的关系;因此人类个体原始DNA资料对于研究疾病的发展进程和日后的个性化诊疗具有不可替代的作用,将其作为健康档案保存对于国家和个人都具有特殊的价值。     

表观遗传修饰在应激诱发抑郁症中的作用

应激可以对个体的生理和行为产生负面影响, 甚至导致抑郁症, 但病因机制尚不清楚。近年来许多研究发现应激导致的表观遗传修饰变化影响抑郁症的发生。表观遗传是指DNA序列不发生变化, 但基因表达却发生了可遗传的改变。应激引起的HPA轴、单胺类递质、BDNF三个方面的表观遗传修饰的变化, 在抑郁症发生中发挥重要作用。最后提出了目前表观遗传机制研究的局限性和未来研究热点。     

思想史视野中的DNA双螺旋发现

医学史上许多丰碑不仅仅只是技术的辉煌,而且是思想史的楼梯口,由此可以提升学科的精神高度,50年前的DNA双螺旋结构的发现就是这样一个精神“事件”。试图穿越生物学实验探究其另一面——思想实验的创新价值;重新审定了物理学对于50年来生命科学的技术和思维引领作用;分析了还原论在DNA之后的价值终结。     

Genes in Context: Gene–Environment Interplay and the Origins of Individual Differences in Behavior

ABSTRACT— Interactions between genes and the environment are a critical feature of development. Insights into the dynamic interplay between these factors have come from laboratory studies exploring experience-dependent changes in gene function, which illustrate the importance of environmental factors in determining activity of the genome. These studies have implications for our understanding of the origins of individual differences in behavior and may provide new ways of thinking about the transmission of traits across generations. Here we will highlight how these new findings illustrate the importance of putting genes in context.     

Semantically induced distortions of visual awareness in a patient with Balint’s syndrome

We present data indicating that visual awareness for a basic perceptual feature (colour) can be influenced by the relation between the feature and the semantic properties of the stimulus. We examined semantic interference from the meaning of a colour word (‘‘RED”) on simple colour (ink related) detection responses in a patient with simultagnosia due to bilateral parietal lesions. We found that colour detection was influenced by the congruency between the meaning of the word and the relevant ink colour, with impaired performance when the word and the colour mismatched (on incongruent trials). This result held even when remote associations between meaning and colour were used (i.e. the word ‘‘PEA” influenced detection of the ink colour red). The results are consistent with a late locus of conscious visual experience that is derived at post-semantic levels. The implications for the understanding of the role of parietal cortex in object binding and visual awareness are discussed.     

DNA methylation and behavioral changes induced by neonatal spinal transection

Although the importance of epigenetic mechanisms in behavioral development has been gaining attention in recent years, research has largely focused on the brain. To our knowledge, no studies to date have investigated epigenetic changes in the developing spinal cord to determine the dynamic manner in which the spinal epigenome may respond to environmental input during behavioral development. Animal studies demonstrate that spinal cord plasticity is heightened during early development, is somewhat preserved following neonatal transection, and that spinal injured animals are responsive to sensory feedback. Because epigenetic alterations have been implicated in brain plasticity and are highly responsive to experience, these alterations are promising candidates for molecular substrates of spinal plasticity as well. Thus, the current study investigated behavioral changes in the development of weight-bearing locomotion and epigenetic modifications in the spinal cord of infant rats following a neonatal low-thoracic spinal transection or sham surgery on postnatal day (P)1. Specifically, global levels of methylation and methylation status of the brain-derived neurotrophic factor (Bdnf) gene, a neurotrophin heavily involved in both CNS and behavioral plasticity, particularly in development, were examined in lumbar tissue harvested on P10 from sham and spinal-transected subjects. Behavioral results demonstrate that compared to shams, spinal-transected subjects exhibit significantly reduced partial-weight bearing hindlimb activity. Molecular data demonstrate group differences in global lumbar methylation levels as well as exon-specific group differences in Bdnf methylation. This study represents an initial step toward understanding the relationship between epigenetic mechanisms and plasticity associated with spinal cord and locomotor development.