Goldfish retina: sign of the rod input in opponent color ganglion cells

After light adaptation, all "on-center" ganglion cells in the dark became "red on-center," and all "off-center" cells turned into "red off-center" cells. On a chance basis, this similitude of effect between the rods and the red cones in opponent color cells was not expected. These findings indicate that in the goldfish there is some similarity between the connections of the rods and of the long-wavelength cones.     

不同光照条件对斑马鱼趋光行为的影响

为探究斑马鱼(Danio rerio)在不同光照条件下的趋光行为差异,记录了6月龄的斑马鱼成鱼在紫外光(ultraviolet, UV)和可见光照射下的行为反应和在无光、紫光(420nm)、蓝光(460nm)、绿光(500nm)、黄光(585nm)和红光(620nm)6种光照条件下的趋光分布情况。结果表明,刺激光为UV时,斑马鱼优先游向黑暗环境一侧,刺激光为可见光时,斑马鱼优先游向可见光一侧;UV和可见光分别设置在试验区A和试验区B时,随着UV刺激强度增加,斑马鱼的偏好指数未呈现明显的增加趋势,UV和可见光同时设置在试验区B时,随着UV刺激强度增加,斑马鱼的偏好指数呈现出明显的下降趋势;5min和30min时斑马鱼的平均分布率均呈现红光区>紫光区>蓝光区>黄光区,绿光区的平均分布率在5min时高于红光区,在30min时介于紫光区和蓝光区之间。研究表明,斑马鱼趋向可见光而远离紫外光,表现出明显的避UV性和趋可见光性,且避UV性与趋可见光性之间存在显著的抑制作用,而无协同作用。此外,斑马鱼对红光、绿光和紫光的喜好程度较高,对黄光的喜好程度较低。研究结果可为斑马鱼视觉生态的...     

Extinction in goldfish: facilitation by intracranial injection of RNA from brains of extinguished donors

Extracts rich in RNA were prepared from the brains of goldfish that had acquired and then extinguished a light-signaled avoidance to shock in an aquatic shuttle-box. Recipient fish injected intracranially with such extracts extinguished the response significantly faster than those injected with extracts prepared from brains of naive donors.     

Synthetic rat scotophobin induces dark avoidance in mice

Two independent research groups replicate alteration of dark preference to dark avoidance by mice injected with synthetic scotophobin, a pentadecapeptide.     

Conditioned "anxiety" and punishment effects on operant behavior of goldfish (carassius auratus)

Hungry goldfish learned to press a lever for worms on a 2-minute variable-interval schedule of reinforcement. Lever pressing was suppressed in the presence of a flashing light by (i) pairing the light with a brief electric shock ("anxiety") and (ii) punishing the lever-pressing behavior with electric shocks.     

黑暗和光照处理对马铃薯块茎愈伤效果影响的比较

【目的】愈伤是马铃薯块茎受损后的典型反应,受外界环境因素影响较大。比较黑暗和光照处理对马铃薯块茎愈伤效果的影响,为马铃薯采后愈伤提供理论支持。【方法】本研究选取‘大西洋’马铃薯原原种为试材,人工切半后用酒精对伤口表面消毒,之后分别在黑暗和光照（11 000 lx）条件下进行（20±3）℃常温（（95±5）% RH）愈伤。通过测定愈伤期间损伤块茎的失重率及损伤接种Fusarium sulphureum 7 d后块茎的病情指数来评价愈伤效果,观察伤口处聚酚软木脂（SPP）、聚酯软木脂（SPA）和木质素的积累量以及伤口表面的色度变化,分析伤口处苯丙烷代谢关键酶活性和相关代谢产物含量的变化。此外,研究光照和黑暗对伤口处过氧化物酶（POD）和多酚氧化酶（PPO）活性,以及对过氧化氢（H₂O₂）含量积累的影响。【结果】愈伤期间,黑暗和光照处理的块茎失重率均逐渐升高。黑暗处理显著低于光照处理,愈伤第7天时,分别比光照处理低54.27％和58.96％。愈伤期间,黑暗和光照处理块茎伤口处的SPP和SPA积累量均逐渐增加,黑暗处理促进了软木脂和木质素在块茎伤口处的积累,愈伤第14天时,聚酚软木脂、聚酯软木脂和木质化细胞层厚度分别比光照处理高38.22%、36.76%和14.71%。愈伤期间,黑暗和光照处理块茎伤口表面的L^*值和b^*值均表现为先下降后上升的趋势。黑暗处理显著降低了伤口表面的L^*和a^*值,增加了b^*值,L^*和a^*值在愈伤第5天时分别低于光照处理13.51%、32.74%。b^*值在愈伤第5天时高于光照处理42.11%。愈伤期间,黑暗处理块茎伤口处的苯丙氨酸解氨酶（PAL）活性迅速上升,而光照处理的上升缓慢,两种处理块茎伤口处的肉桂酸-4-羟化酶（C4H）活性先上升后趋于平稳,两种处理块茎伤口处的4-香豆酰辅酶A连接酶（4CL）活性先迅速上升后持续下降。黑暗处理块茎伤口处的苯丙氨酸解氨酶、肉桂酸-4-羟化酶、4-香豆酸CoA连接酶的活性显著高于光照处理,愈伤第7天时,分别比光照处理高79.56%、10.71%和72.48%。黑暗和光照处理块茎伤口处的H₂O₂含量在愈伤第一周均迅速上升,之后趋于平稳。两种处理块茎伤口处的POD活性在愈伤期间均显著上升。黑暗处理块茎伤口处具有较高的过氧化物酶活性和H₂O₂含量,第5天时分别高于光照处理49.8%和49.85%。此外,黑暗处理还提高了伤口处组织的多酚氧化酶活性,在愈伤第3天时显著高于光照处理12.93%（P＜0.05）。【结论】黑暗对马铃薯块茎愈伤具有促进作用,而光照则对块茎愈伤具有一定程度的抑制。黑暗对愈伤的促进作用与激活块茎伤口处的苯丙烷代谢,加速伤口部位多酚氧化酶和过氧化物酶活性以促进软木脂和木质素的积累密切相关。     

Reversal by L-dopa of impaired learning due to destruction of the dopaminergic nigro-neostriatal projection

Rats receiving bilateral stereotaxic injections of 6-hydroxydopamine into the zona compacta of the substantia nigra failed to learn a one-way active avoidance response. Small doses of L-dopa (1.5 milligrams per kilogram of body weight) in combination with a peripheral decarboxylase inhibitor reversed this impairment. Animals with lesions which acquired the avoidance response during L-dopa administration retained this response when drug treatment was discontinued. These experiments suggest that the dopaminergic nigro-neostriatal projection serves a critical function in the acquisition of learned instrumental responses.     

光暗条件与触角去除对中华通草蛉成虫取食的影响

为了解视觉、嗅觉单一和双重感觉通道的作用,室内研究了光、暗、触角正常和触角去除4种处理对中华通草蛉成虫取食的影响。结果发现:①光条件下触角去除的中华通草蛉平均取食率(13.67%)高于其暗条件下取食率(3.67%),表明光暗条件及与其关联的视觉对其取食率有影响;②触角正常的中华通草蛉暗条件下平均取食率(30.67%)大于触角去除个体的取食率(3.67%),表明嗅觉对其取食率有显著影响;③4种处理中光条件下触角正常平均取食率最高(43.00%),暗条件下触角正常次之(30.67%),光条件下触角去除居三位(10.67%),暗条件下触角去除最低(3.67%),表明触角去除较光暗条件对其取食率的影响更大(依次分别为88.05%、73.18%),且视嗅觉间具有协同作用;④光、暗条件对触角去除的雌、雄虫取食影响率分别达72.73%和73.70%,触角去除对暗条件下的雌、雄虫取食影响率分别为86.67%和89.37%,表明其性别间各处理的影响差异甚小。综上表明光、暗、触角及其相关的视、嗅觉是影响中华通草蛉取食的重要因素,其中嗅觉影响更大。     

中国梨木虱翅型变化及其影响因素初探

对中国梨木虱不同月份和不同光周期下的翅型变化进行研究.结果表明,梨木虱翅型随月份发生明显变化,5—9月为短翅型,10月至次年4月为长翅型.恒温20℃条件下,短光周期(9 h光/15 h暗、8 h光/16 h暗)可诱导产生长翅型,而长光周期(12 h光/12 h暗,10 h光/14 h暗)可诱导产生短翅型.短光周期下长翅...     

基于结构洞指数的网络节点重要度评估

运用双阶差分模型探究了并购与新建投资模式下公司避税效应的非对称性，并进一步从事后的视角探究该非对称性是否是影响企业投资模式选择的显著影响因素。研究发现：相比于新建投资，并购增加了收购方会计利润应税所得差异，且实质性地降低了其所得税实际有效税率，这表明不同投资模式下公司避税效应存在理论预期的非对称性。进一步研究发现，改变企业会计利润应税所得差异以及会计利润应税所得操纵程度是影响企业投资模式选择的重要因素。从事后的视角来看，企业很可能为了获取更大程度的公司避税效应而选择并购行为。     

光质对甜茶愈伤组织生长及甜茶甙产量的影响

 本文研究了不同光质对甜茶（Rubus suavissimus S.Lee）愈伤组织生长及甜茶甙（Rubusoside）产生的影响。愈伤组织在黑暗中培养28天可获得最大的生物量。与黑暗相比，白光、蓝光、红光、远红光及短红光均对细胞生长有一定抑制作用，其中蓝光抑制作用最强，其次为红光。但是蓝光促进甜茶甙的产生，在7天时，可获得高于在其它光质培养下的甜茶甙含量。黑暗下甜茶甙含量最低。为了获得较高的甜茶甙产量，甜茶愈伤组织分两步培养，在黑暗中培养28天，然后转移到蓝光下培养7天。     

Lizard reflectivity change and its effect on light transmission through body wall

Light transmission through the body wall of living, color-labile desert iguanas (Dipsosaurus dorsalis) was measured by spectrophotometry. In the dark phase, the body wall's absorption of ultraviolet light and visible light was approximately twice that of the body wall in the light phase. The shorter wavelengths of ultraviolet could penetrate the body wall in the light phase but not in the dark phase. The intensity and wavelengths of light which could penetrate the body wall without pigments are potentially mutagenic when judged by bacterial standards.     

金鱼品系的遗传多样性分析及亲缘关系初探

采用RAPD技术对草金(Grassgoldfish)、红龙睛(Red dragoneye goldfish)、鹤顶红(Red-head wen goldfish)、水泡(Blisters-eye goldfish)、黑寿(White-head oval goldfish)等5个金鱼代表品种的遗传多样性及其亲缘关系进行研究。用14个引物在5个金鱼群体中共检测出116个位点,其中多态性位点27个。金鱼群体总的DNA多态位点百分率为23.3%。结果表明,5种金鱼群体间的遗传相似性指数均在0.8759￣0.818之间,存在一定的差异,但未达到显著水平,群体间遗传多样性差异不明显。群体间遗传相似性度最小的为草金和黑寿(0.8759),其遗传距离最大(0.1241),说明这2种群体亲缘关系最远;鹤顶红与黑寿的遗传相似性度最大(0.9182),其遗传距离最小(0.0818),可推断两者的亲缘关系较近。UPGMA法和NJ法的聚类分析显示,草金和红龙睛,鹤顶红和黑寿有较近的亲缘关系,这与传统金鱼品种演化关系的观点一致。研究金鱼遗传多样性对保护金鱼的种质资源有重要意义。     

外界条件对4个安祖花品种花粉萌发及生长的影响

通过体外萌发的方法,研究了火焰、密西西比、成功、火鹤4种安祖花花粉萌发的最佳培养基配方、花粉的最佳采集时间以及光暗条件对安祖花花粉萌发率的影响。结果表明,火焰、密西西比和火鹤花粉萌发的最佳培养基配方为:蔗糖5%+硼酸10μL/mL,pH值为6.0;成功花粉萌发的最佳培养基配方为:蔗糖5%+硼酸25μL/mL,pH值为6.5。在最适培养条件下,4种安祖花花粉萌发率由高到低依次为密西西比>成功>火焰>火鹤;不同品种的安祖花均在16:00采集的花粉萌发率最高;4种安祖花的花粉均在光照条件下萌发率高,畸形率则相反,大多数品种的花粉在黑暗条件下萌发时会形成更高比例的畸形花粉;花粉管生长速率以火焰最大。     

白黄侧耳子实体颜色遗传规律

【目的】研究白黄侧耳子实体颜色的遗传规律,为平菇的色泽定向育种提供遗传学依据。【方法】以白黄侧耳Pleurotus cornucopiae白色菌株CCMSSC00358（P-w）和深灰色菌株CCMSSC00406（P-d）为材料,构建自交系2个(P-w×P-w、P-d×P-d）,两亲本杂交一代（F1,P-w×P-d）,杂交一代中浅灰色和深灰色子实体与二亲本的回交系4个（F1浅×P-w、F1浅×P-d,F1深×P-w、F1深×P-d）,共7个家系群体。出菇期观测统计各家系群体不同颜色的个体数。【结果】菌株P-w的自交系出菇29个,子实体全部为白色。菌株P-d的自交系出菇17个,子实体浅灰色5个、深灰色12个,经卡方检验,浅灰色﹕深灰色＝1﹕3。杂交一代（F1,P-w×P-d）出菇82个,子实体颜色呈现由浅向深的连续分布,无白色子实体出现。按照深浅分为浅灰色和深灰色两大类,分别为47个和35个,经卡方检验,比例为1﹕1。在回交系中,F1代与白色亲本杂交,经卡方检验,出现深灰色﹕浅灰色﹕白色=1﹕4﹕3的分离;与深灰色亲本杂交,无白色子实体出现,经卡方检验深灰色﹕浅灰色=5﹕3。【结论】白黄侧耳子实体的颜色性状为数量性状,深灰色对白色呈不完全显性,由不同位点上的两对主基因控制。     

Light-enhanced potassium absorption by corn leaf tissue

The rate of absorption of potassium by slices of corn leaf in the light was about twice the rate in the dark. When the light was turned on or off, changes in the rate of absorption took place some minutes after the change in illumination. Experiments with the antimetabolites, 2,4-dinitrophenol and cyanide, indicated that the source of energy for active accumulation of potassium by green tissue in the light was different from that in the dark. In the light, energy was closely linked to photosynthetic reactions; in the dark, it was linked to respiratory processes.     

Mycoplasma pneumoniae: proposed nomenclature for atypical pneumonia organism (Eaton agent)

The light intensity-fusion frequency relationship of the goldfish electroretinogram follows the Ferry-Porter law except at the higher intensities. Maximum fusion frequency increases with temperature thus contradicting the results of studies elsewhere on the behavioral responses in sunfish.     

基于基因富集数据的中国金鱼品种谱系研究

金鱼（Carassius auratus）起源于中国,是由野生鲫鱼驯化而来的一种观赏性鱼类。金鱼不同品种间存在巨大外形差异,长期的杂交与人工选择产生了众多的品种,但也导致其谱系关系混乱复杂,划分品种的难度加大。人们尝试了许多方法明确金鱼各品种间的谱系历史与杂交关系,但是至今未取得进展。本研究收集了11个中国金鱼品种,共计59个个体,利用跨物种靶基因富集和高通量测序获取了各品种目标基因序列。以斑马鱼4 434个单拷贝基因位点为参考序列,将金鱼对应的基因按照异源四倍体亚基因组分组,富集的序列分别按照两个亚基因组进行比对分型,产生35 298个单核苷酸多态性（SNPs）位点数据,用于金鱼品种谱系历史和杂交关系的研究。通过主成分分析,品种遗传结构以及系统发育网状图的构建,揭示了中国部分金鱼品种的遗传关系,解释了它们的遗传演化过程：（1）龙睛、琉金两种文种金鱼与和金（文种金鱼）关系较近;珍珠鳞、狮头不是来自于和金,而是独立演化而来。（2）以兰寿为代表的蛋种金鱼虽然早于水泡眼出现,但水泡眼是文种金鱼先出现水泡眼特征,然后文种水泡背鳍消失,演化出现代金鱼中的主流水泡眼。这也解释了蛋种金鱼中,水泡眼出...     

光对激素调控水稻幼苗主根生长的影响

本研究利用日本晴水稻作为研究材料,分析了黑暗和光照条件下不同植物生长调节剂对植物主根生长的影响。结果表明,IAA、JA、ACC、KT和2,4-EBL均抑制水稻幼苗主根的生长,抑制效果与浓度呈正相关;黑暗和光照条件下生长的水稻幼苗对植物生长调节剂的敏感性不同,IAA、JA、KT和2,4-EBL对黑暗条件下生长的水稻幼苗主根的抑制效果更为明显,而ACC对光下生长的水稻幼苗主根的抑制效果更明显,据此推测,光影响水稻幼苗对植物激素的敏感性。     

Self-trapping of dark incoherent light beams

"Dark beams" are nonuniform optical beams that contain either a one-dimensional (1D) dark stripe or a two-dimensional (2D) dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark beams (dark solitons) have been observed using coherent light only. Here, self-trapped dark incoherent light beams (self-trapped dark incoherent wavepackets) were observed. Both dark stripes and dark holes nested in a broad partially spatially incoherent wavefront were self-trapped to form dark solitons in a host photorefractive medium. These self-trapped 1D and 2D dark beams induced refractive-index changes akin to planar and circular dielectric waveguides. The experiments introduce the possibility of controlling high-power coherent laser beams with low-power incoherent light sources such as light emitting diodes.