跨通路注意的失匹配负波研究

采用“跨通路延迟反应”实验模式 ,提高了非注意纯度 ,排除了偏差刺激中的目标任务因素 ,以 1 2名青年正常人为被试者 ,研究注意与非注意条件下的ERPs.实验分为 2项 :( 1 )注意视觉通路 ,忽视听觉通路 ;( 2 )注意听觉通路 ,忽视视觉通路 .主要分析偏差刺激ERP减去标准刺激ERP所得之偏差成分 .结果发现视听通路在注意条件下均能产生MMN ,N2b和P3,在非注意时主要产生MMN .听觉MMN与视觉MMN具有如下共同特征 :注意时视听最大MMN波幅分布于它们的初级感觉投射区 ,而在非注意条件下视听最大MMN波幅均分布于额中央部 .视觉MMN与听觉MMN波幅无显著性差异 .MMN波幅及其头皮分布不受注意影响 ,提示MMN波幅是反映自动加工的重要ERP指标 ;但视听觉MMN潜伏期皆受注意影响 ,表明MMN不仅仅反映自动加工 ,尚与控制加工有关     

山西亚高山草甸植被生物量的地理空间分布

以山西省境内分布的典型亚高山草甸为对象,采用收获法获取植被生物量数据,结合经度、纬度和海拔3个地理因子,分析总生物量(TB)、地上生物量(AGB)、地下生物量(BGB)及根冠比(R/S)沿不同地理梯度的变化规律,从群落水平上探究山西亚高山草甸植被生物量的地理空间分布特征。结果表明:(1)TB、AGB、BGB在地域上表现较大变异。AGB变异最大,在32.50~756.00 g·m-2;BGB次之,变化范围为140.50~1586.50 g·m-2;TB波动最小,在248.25~2342.50 g·m-2。(2)TB随海拔升高显著减小(P0.05),随经度增加缓慢增大(P0.05),随纬度增加略微减小(P0.05),在1700~1800 m、113.4°E—113.85°E、35°N—35.5°N处最大(平均为896 g·m-2)。(3)AGB随纬度增加、海拔升高显著减小(P0.001),随经度增加逐渐增大(P0.05),在1700~1800 m、112.05°E—112.5°E、35°N—35.5°N处最大(平均为366.06 g·m-2)。(4)BGB随纬度增加呈"降低-升高-降低"的变化趋势,整体略有增大(P0.05),随经度增加也略有增大(P0.05),而随海拔升高显著增大(P0.05),在3000~3100 m、113.4°E—113.85°E、35°N—35.5°N处最大(平均为745.63 g·m-2)。(5)R/S随纬度增加、海拔升高显著增大(P0.05),随经度增加略有增大(P0.05);与纬度、海拔呈显著的幂指数函数关系(P0.05),且表现为等速增长(幂指数平均为1.025)。RDA分析结果表明,在一定范围内,对亚高山草甸植被不同生物量特征影响较大的为纬度和海拔因子,最小影响因子是经度,地上生物量与经纬度和海拔均呈显著的负相关,生物量更多地分配到地下部分。     

绵羊皮肤中GHR、IGF-1和IGF-1R基因表达的发育性变化及品种特点

采用相对定量反转录多聚酶链式反应 (RT-PCR)方法, 以18S rRNA作内标, 研究了罗米丽(Romilly Hillys)×中国美利奴(新疆军垦型)杂交一代优质细毛羊和哈萨克粗毛羊皮肤中生长激素受体(GHR)、胰岛素样生长因子1(IGF-1)和胰岛素样生长因子1受体(IGF-1R) mRNA发育性变化并进行了品种间比较。分别于30、60、90、135、180和255日龄称重、采毛样, 并于30、90、135和255日龄采皮样。结果表明: 粗毛羊和细毛羊体重、羊毛生长的发育模式没有明显的差异, 30~135日龄体重迅速增加, 135~255日龄增重十分缓慢; 30~135日龄羊毛日增长逐渐增加, 135~180日龄羊毛生长十分缓慢, 而180~255日龄又上升到较高水平。粗毛羊皮肤中GHR mRNA在30~90日龄显著增加 (P<0.05), 90日龄达到高峰, 此后显著下降(P<0.05); 细毛羊在135日龄时GHR mRNA极显著地升高(P<0.01), 此后又极显著地下降。粗毛羊皮肤中IGF-1、IGF-1R mRNA 30~90日龄上升, 90日龄之后极显著下降(P<0.01); 细毛羊皮肤中IGF-1、IGF-1R mRNA出生时较高, 然后逐渐下降。品种之间比较, 细毛羊GHR mRNA出现高峰晚于粗毛羊, 135日龄高峰时显著地高于粗毛羊; 粗毛羊IGF-1、IGF-1R mRNA在90日龄出现高峰, 并极显著或显著地高于细毛羊; 粗毛羊90日龄前GHR、IGF-1和IGF-1R mRNA高于细毛羊, 之后低于细毛羊。结果提示: 绵羊皮肤中GHR、IGF-1和IGF-1R基因表达有特定的发育模式, 并存在品种差异。     

二花脸和大白猪的脂肪组织中GH-R、IGF-1和IGF-Ⅰ R基因表达的发育性变化

分别于出生当天、3、20、30、45、90、120、180日龄随机屠宰二花脸公、母猪各4头(30日龄仅有公猪),于20、30、90、120、180日龄随机屠宰大白猪公猪4头,采集背部皮下脂肪组织.用RT-PCR方法,以18S rRNA作内标,定量分析脂肪组织中生长激素受体(GH-R)、胰岛素样生长因子-1(IGF-1)及胰岛素样生长因子Ⅰ型受体(IGF-Ⅰ R)基因表达的发育性变化,并进行品种和性别间比较.结果表明:脂肪组织中GH-R mRNA的表达有明显的发育性变化及品种差异,二花脸母猪GH-R mRNA水平出生时较低,45日龄达到高峰,之后维持稳定;二花脸公猪GH-R mRNA水平在出生时较高,至45日龄达到最高值,之后显著下降,但总体上没有性别差异;大白猪公猪GH-R mRNA水平极显著低于二花脸公猪(P＜0.01).脂肪组织中IGF-1 mRNA的表达有明显的发育性变化及性别和品种差异,二花脸母猪显著低于公猪(P＜0.05),大白猪公猪极显著低于二花脸公猪(P＜0.01); 脂肪组织中IGF-Ⅰ R mRNA的表达有明显的发育性变化,但在总体上没有明显的性别和品种差异.结果提示:猪脂肪组织中GH-R、IGF-1和IGF-Ⅰ R的基因表达有特定的发育模式,IGF-1基因表达的品种差异可能正是两品种猪脂肪沉积规律不同的主要原因之一.     

老龄化对内源性注意的影响研究

目的:观察老年人和年轻人的内源性注意行为学及事件相关电位(ERP)表现,探讨老龄化对内源性注意的影响及其机制。方法:参考Posner的经典的"cue-target"范式设计内源性注意任务,分别记录和分析年轻人和老年人行为学和事件相关电位波形P1、N1,比较老年人和年轻人在内源性注意任务中的不同表现。结果:在内源性注意条件下,年轻人的反应时明显短于老年人(P0.05),对于N1成分的波幅,年龄主效应显著(P0.05),年轻人较老年人诱发更大的N1波幅。对于N1成分的潜伏期,年龄主效应显著(P0.05),年轻人潜伏期明显短于老年人。结论:老龄化对内源性注意的早期阶段有影响,在提高老年人注意力时应当对注意的不同类型进行评估和分类以采取合适的治疗策略。     

鲤幼鱼快速启动游泳能力及电刺激参数的影响

为了研究鲤(Cyprinus carpio)幼鱼快速启动游泳能力并揭示电刺激参数的影响,将90尾鲤幼鱼(体长6.47 cm ±0.09 cm;体重6.36 g±0.03 g)在水温25.0℃±0.5℃的条件下分别采用4个不同的刺激场强(0.25、0.40、0.55和0.70 v·cm-1)和5个不同的刺激历时(10、50、90、130和170 ms)测定实验鱼的快速启动游泳能力.结果表明:电刺激场强由0.25 v·cm-1分别上升至0.40、0.55 v·cm-1时,第一阶段偏转角度(θs1)、第二阶段最大线性加速度(αmax)和速度(Vmax)随刺激场强的升高而显著增大(P＜0.05);而当刺激场强高于0.55 v·cm-1,上述3个参数却无显著差异(P＞0.05);刺激历时在10 ～50 ms范围内,αmax 和Vmax随刺激历时的延长而显著增大(P＜0.05),当刺激历时长于50 ms时上述2个参数均无显著差异(P＞0.05);在场强和历时分别为0.55 v·cm-1和50 ms条件下,鲤幼鱼的θs1、αmax和Vmax分别是(56.51±4.11) deg、(31.60±3.62)m·s-2和(1.34±0.07)m·s-1;鲤幼鱼采取“快速直线”的逃逸策略,具有较强的快速启动游泳能力,鱼类的电刺激反应受刺激参数的影响并且存在阈值.     

氮磷互作对菊芋块茎产量和品质的影响

为探明肥料互作对菊芋产量及品质的影响,以“南芋1号”为试验材料,通过正交田间试验,对氮(N)、磷(P)及其交互作用对菊芋块茎产量和品质的影响进行了研究.结果表明:N、P对菊芋块茎产量、干物质含量,总糖、还原糖和菊糖含量具有极显著影响(P＜0.01);N、P交互作用对菊芋块茎产量、干物质和还原糖含量有显著影响(P＜0.05),对块茎总糖和菊糖有极显著影响(P＜0.01);当磷肥为135 kg·hm-2时,与氮肥存在交互效应;当氮肥低于180 kg·hm-2时,为正交互效应,表现出协同促进作用,氮肥高于180 kg·hm-2时,为负交互效应,表现出拮抗作用;当氮肥为180 kg·hm-2、磷肥为135 kg·hm-2时,氮磷正交互效应增强,氮磷表现出协同促进作用,菊芋块茎产量最高,且菊芋块茎的干物质含量、总糖、还原糖和菊糖含量达到最高值,即菊芋块茎能达到最高产量和最优品质.综上,在山东莱州地区菊芋大田种植的基础施肥量宜为纯氮为180 kg·hm-2、P2O5为135 kg·hm-2.     

情绪面孔对听觉通道短时距内隐知觉的影响

时间知觉是人类的一项基本能力.日常生活经验表明时间知觉容易受到情绪的影响.但是在前人的研究中,这些影响往往伴随着主动注意和外显的运动反应.这里关注的是不伴随主动注意和外显运动反应的内隐时间知觉是否受到情绪面孔的影响.被试在主动完成一个由情绪面孔组成的视觉辨别任务的同时,被动地听一系列声音刺激.声音刺激的刺激启动异步时间(stimulus onset asynchrony,SOA)中,80%是标准SOA(800ms),20%是偏差SOA(400,600 ms).对频繁出现的标准SOA和偶尔出现的偏差SOA诱发的事件相关电位(event-related potential,ERP)进行记录.2个短的偏差SOA(400和600ms)引发了2个变化相关的ERP成分:失匹配负波(the mismatch negativity,MMN)和P3a.代表对无规律变化早期检测的MMN波幅受到了情绪面孔的影响.与愉快和中性面孔相比,恐惧面孔降低了MMN波幅.对于400ms偏差SOA,与恐惧面孔和中性面孔相比,愉快面孔增加了P3a波幅.该ERP研究提示听觉通道的内隐时间知觉受到情绪面孔的影响,恐惧面孔降低了内隐时间知觉的准确性.     

前交叉韧带方位角变化的解剖学测量研究

目的:探讨前交叉韧带(anterior cruciate ligament,ACL)在膝关节不同屈曲角度时的方位角变化,为ACL损伤诊断和重建研究提供解剖学支持。方法:成人膝关节标本10具,解剖观察ACL形态,用Photoshop软件测量膝关节不同屈曲角度下ACL方位角变化。结果:0°、30°位膝关节中ACL胫骨角大于ACL股骨角,有显著性差异(P0.01);60°、90°位膝关节中的ACL胫骨角小于股骨角,有显著性差异(P0.01)。膝关节0°、30°、60°、90°ACL胫骨角由大渐小,各角度间均有显著性差异(均P0.01)。膝关节0°和30°的ACL股骨角比60°和90°时小,有显著性差异(均P0.01),0°与30°间无显著性差异(P0.05),60°小于90°,有显著性差异(P0.01)。结论:ACL于膝关节0°和30°位时,后外侧束(posterolateral bundle,PLB)发挥主要作用,ACL诊断或重建主要参考胫骨角;60°、90°时ACL前内侧束(anteromedial bundle,AMB)发挥主要作用,ACL诊断或重建主要参考股骨角。ACL方位角可作为ACL损伤诊断和手术重建的重要参考。     

皖南花猪11种血液生化指标的发育性变化及性别差异

随机选择出生30、45、90、180日龄的皖南花猪公母各5头,测定了11项血清生化指标.结果显示:血糖(GLU)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)、脂联素(ADP)、瘦素(leptin)和IgG有极显著的发育性变化(P0.01);而甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、IgA和IgM等没有明显的发育性变化.母猪的TG、TC、HDL-C和IgM极显著或显著大于公猪(P0.01或P0.05),其他血清生化指标虽在总体上没有性别差异,但在有些日龄差异明显,大多表现为母猪在90或180日龄大于公猪.结果表明:皖南花猪血液生化指标有特定的发育性模式,并存在不同程度的性别差异.     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Tubular networks in the terminal endings of the visual receptor cells in the human,the monkey,the cat and the dog

Summary A tubular network was found in the terminal endings of the visual receptor cells in the human, the monkey (Macaca mulatta), the cat and the dog. These tubules are arranged in close groups in the vicinity of the synaptic lamellae and the invaginated dendrites. According to the form, diameter, density of the tubules and to the consistence of the network formed by them one can distinguish at these places an initial type (type I), a transitory (type II) and a vesicular one (type III). In the the type III branching, bizarre forms are frequent. The diameter of all the tubules reaches 500–600 Å, their density and walls being the same as in the synaptic vesicles.Similar networks also occur in the axons of the visual receptor cells of the monkey.

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Zusammenfassung In den Endigungen der Photorezeptorzellen von Mensch, Affe (Macaca mulatta), Katze und Hund kommen aus Tubuli bestehende Komplexe vor. Organellenartig in geschlossenen Gruppen angeordnet, liegen sie in Nähe der synaptischen Lamellen und der invaginierten Dendriten. An diesen Stellen kann man nach Form, Durchmesser, Dichte und Konsistenz der von den Tubuli gebildeten Komplexe drei Typen unterscheiden: 1. einen initialen (Typus I), 2. einen Übergangstypus (Typus II) und 3. einen vesiculären Typus (Typus III). In letzterem kommen häufig verzweigte, bizarre Formen vor. Der Durchmesser sämtlicher Tubuli erreicht 500–600 Å. Ihre Dichte und ihre Wand gleicht denen der synaptischen Vesikel.Ähnliche Komplexe fanden wir auch in den Axonen der Photorezeptorzellen vom Affen.

     

Assessing the Physiological State of the Fucoids from the Barents Sea Littoral by the End of the Polar Night

Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m² s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.     

Arranging the elements of the potassium channel: the T1 domain occludes the cytoplasmic face of the channel

The voltage-gated potassium channel is currently one of the few membrane proteins where functional roles have been mapped onto specific segments of sequence. Although high-resolution structures of the transmembrane portions of three bacterial potassium channels, the tetramerization domain and the cytoplasmic ball are available, their relative spatial arrangement in mammalian channels remains a matter of ongoing debate. Cryo-electron microscopic images of the six transmembrane voltage-gated Kv channel have been reconstructed at up to 18 Å resolution, revealing that the T1 domain tetramerizes and is suspended below the transmembrane segments. However, the resolution of these images is insufficient to reveal the location of the third piece of the puzzle, the inactivating ball domain. We have used the aberrant interactions observed in a series of chimæric channels to establish that an assembled T1 domain restricts access to the cytoplasmic face of the channel, suggesting that the N-terminal ball and chain may be confined in the space between the T1 domain and the transmembrane portion of the channel.     

Feeding the vertebrate retina from the Cambrian to the Tertiary

The retina of the vertebrate eye is metabolically active and requires nutritive support. During the last 540 million years it has evolved into forms as complicated and nutritionally demanding as those found in avian or primate eyes. Diffusion from the choroid is generally able to supply the metabolic needs of thin retinae. However, when the thickness exceeds the limits of diffusion, structures are needed to supplement the vascular supply from the choroid. These supplemental nutritive devices include the choroidal gland, the falciform process and preretinal vascular plexus of fish, the conus papillaris of lizards, the pecten oculi of birds, the intraretinal vessels of mammals and a few novel systems that remain difficult to classify. These vascular systems are among the most variable features of the vertebrate eye. Here, we review classical and recent findings regarding such retinal nutrition systems, propose a three category classification for them based on histologic origins and speculate on the evolutionary forces which drove their development.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418     

Separation of the pineal vesicle from the wall of the third ventricle during the post-hatching development of the chicken

Summary According to light- and electron-microscopic observations the pineal organ of the 3-day-old chicken consists of a prominent end vesicle and a tapering parenchymal stalk. During this stage the pineal lumen is in open communication with the third ventricle. However, in the 40-day-old chicken, which still possesses a well-developed end vesicle, the proximal portion of the pineal stalk displays regressive changes leading to local fragmentation. At this stage the pineal stalk is reduced, and the pineal lumen is missing. In 1-year-old chickens the parenchyma of the proximal portion of the stalk is further diminished, and in 3-year-old domestic fowl is completely displaced by bundles of collagenous fibers, only some nerve fibers being present. This post-hatching pineal development may reflect the sequence of changes leading from pineal sense organs to pineal glands.This work was supported by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan