Function of Giant Mauthner's Neurons in the Lungfish

Unit spikes were recorded from the spinal cord of the lungfish Protopterus and were identified with Mauthner's axon. With these spikes occurred nongraded tail flips suggesting startle responses. The tail flip and the giant spike resulted from certain forms of jarring and prodding. The conduction velocity for the slightly myelinated. 45 micro diameter fibers was 18.5 m/sec.     

The site of action of DDT in the cockroach

(1) Although DDT undoubtedly affects motor nerves and muscle fibers in concentrations greater than 1,000 ppm, this action cannot be directly responsible for the clonic tremors in the DDT-poisoned cockroach which can be produced by internal concentrations of the order of 5 ppm. (2) DDT has no significant action on the cockroach central nervous system. (3) DDT emulsion perfused through the leg of the cockroach in concentrations as low as 0.01 ppm causes the appearance of a series of high frequency trains of axon spikes in the afferent fibers. (4) It is concluded that the tremors characteristic of DDT poisoning are due to an intense afferent bombardment of the motor neurons.     

Synchronous bursts of action potentials in ganglion cells of the developing mammalian retina

The development of orderly connections in the mammalian visual system depends on action potentials in the optic nerve fibers, even before the retina receives visual input. In particular, it has been suggested that correlated firing of retinal ganglion cells in the same eye directs the segregation of their synaptic terminals into eye-specific layers within the lateral geniculate nucleus. Such correlations in electrical activity were found by simultaneous recording of the extracellular action potentials of up to 100 ganglion cells in the isolated retina of the newborn ferret and the fetal cat. These neurons fired spikes in nearly synchronous bursts lasting a few seconds and separated by 1 to 2 minutes of silence. Individual bursts consisted of a wave of excitation, several hundred micrometers wide, sweeping across the retina at about 100 micrometers per second. These concerted firing patterns have the appropriate spatial and temporal properties to guide the refinement of connections between the retina and the lateral geniculate nucleus.     

中国半野生小麦的酯酶同工酶分析

对 2 8份中国特有半野生小麦的幼苗、剑叶及幼穗的酯酶同工酶分析表明 :酯酶在这些材料中存在组织特异性。幼苗电泳出 10条带 ,8种酶谱类型 ;剑叶 15条带 ,7种类型 ;幼穗 18条带 ,2 0种类型。幼穗的酯酶同工酶在材料个体间类型最为丰富 ,更能反映个体间的遗传多样性。聚类分析结果表明 ,云南小麦和西藏半野生小麦亲缘关系较近 ,它们与新疆小麦的关系相对较远     

大穗型与多穗型小麦单株生产潜力研究

为了解大穗型与多穗型小麦基因型的单株生产潜力,以5个大穗型基因型和5个多穗型基因型为试验材料,在株距14cm、8cm和2cm 3种种植密度条件下对单株产量及产量因素进行试验研究。结果表明：两种穗型的基因型都有较高的单株产量潜力,在株距14cm密度处理中单株产量最高,均达到20 g;多穗型基因型单株产量在株距14cm和2cm的密度处理中分别比大穗型基因型多0.8g和0.5g,差异显著,在株距为8cm的密度处理中后者显著高于前者,表明大穗型基因型对生存环境反映敏感,适应范围窄,而多穗型基因型则具有更好的适应能力;多穗型基因型在株距14cm和2cm密度处理条件下穗数高出幅度大于穗粒重高出的幅度,说明穗数是影响其单株产量在这两个密度处理条件下高于大穗型基因型的主要原因。     

Olfactory epithelium: unitary responses in the tortoise

In the tortoise, Gopherus polyphemus, single unit spikes in the olfactory epithelium in response to amyl acetate were positive relative to the slow potential. The number of spikes in a response train was 4 to 15, the duration 3 to 4 msec, the height 0.5 to 2 mv. The height of successive spikes in a train decreased. The decrement in height, the number, and the frequency of spikes changed with the strength of the odor.     

Dendritic spikes and their inhibition in alligator Purkinje cells

Alligator Purkinje cells generate action potentials in the peripheral dendritic tree, after synaptic depolarization via superficial parallel fibers. These action potentials are inhibited at the dendrite level by preceding parallel-fiber volleys at close intervals. We conclude that this inhibition is produced by the activation of the inhibitory interneurons of the molecular layer, the stellate cells, which establish synaptic contacts with the dendrites of the Purkinje cells.     

外源氮对离体麦穗干物质及氮素积累的影响

采用离体穗培养的方法,选取花后7d的周麦18为材料,研究了外源氮(0、0.5、1.0、2.0 g/LNH4NO3)对离体麦穗干物质及氮素积累的影响。结果表明,随培养天数的增加,离体穗干物质积累总量呈增加趋势,外源氮促进了离体穗干物质的积累,提高了干物质在籽粒中的分配比例。在外源氮供给下,离体穗营养器官干物质向籽粒的转移率和贡献率均降低,籽粒光合产物积累量增加。外源氮增加了籽粒中氮素的含量和积累量,提高了离体穗中氮素在籽粒中的分配比例。在本试验中,2.0 g/L NH4NO3处理效果最佳,促进了离体穗尤其是籽粒的生长,提高了籽粒的氮素含量和积累量,对籽粒建成具有促进作用。     

Transepithelial potentials in Hydra

There is a maintained electrical potential of 15 to 40 millivolts across the two epithelial layers forming the body wall of Hydra, the inside of the animal being positive. Negativegoing (depolarizing) spikes are recorded spontaneously and sometimes in response to depolarizing current pulses. These spikes usually overshoot the zero potential level. The large size of the spikes and the orientation of the potential difference across the body wall indicate that this electrical activity is epithelial rather than nervous in origin.     

早籼金早09直播高产群体经济性状与产量分析

通过2009～2012年的多年多点金早09直播稻示范方的建立,金早09的高产潜力以及适应不利气候环境的能力得到了充分体现,通过相关和通径分析表明:有效穗对金早09直播稻的产量贡献最大,穗实粒数次之。线性回归分析表明:金早09直播稻产量达7500 kg/hm2以上,有效穗、穗实粒数2个性状在95%的置信区间分别为(349.82±8.36)万/hm2、(101.32±3.17)粒,这将为金早09直播稻高产群体结构的搭建提供有力依据。     

协优57穗部性状及不同抽穗期分蘖成穗规律分析

（１）协优５７穗部性状分析结果表明：穗长与穗粒数呈极显著正相关。１次枝梗数与２次枝粳数、２次枝梗结实率与穗结实率呈显著正相关；２次枝梗着粒密度与１次枝梗着粒密度都很稳定，变幅分别是１．２０６～１．２６７粒／ｃｍ与０．５４３～０．７４３粒／ｃｍ。（２）不同时期分蘖穗粒结构：秧田分蘖穗及主茎穗的穗粒数多、结实率高，大田低位蘖次之；大田高位蘖最少。与汕优６３相比：协优５７秧田分蘖穗、主茎穗、大田低位蘖次之；大田低位蘖穗的穗粒数、结实率相关不大，而大田高位蘖穗的穗粒数、结实率较高。结论：协优５７的每穗粒数多、结实率高是其高产的主要原因。     

Breeding for pre-harvest sprouting resistance in bread wheat under rainfed conditions

Pre-harvest sprouting in wheat is the germination of seeds within the spikes when rains occur after or during grain ripening, which occurs commonly in the barani tract of Pakistan. Therefore, 10 cultivars and five advanced lines of spring bread wheat were evaluated for pre-harvest sprouting resistance. After natural rainfall, seeds were immediately collected from the wet spikes and tested for germinating ability. Three different germination tests were applied to hand-threshed seed: (1) spikes threshed on the day of sampling and germination tested immediately, (2) spikes threshed on the day of sampling and germination tested 1 week later, and (3) spikes threshed 1 week after sampling and germination test immediately after threshing. Seeds and spikes kept for 1 week were place on blotting paper at room temperature. Cultivars BARS-09, 09FJ17, Doukkala-12, NARC-09 and Ouassou-20 exhibited higher sprouting resistance while other genotypes were susceptible to pre-harvest sprouting in each of the three tests. A diallel crossing was conducted with six susceptible and two resistant genotypes to assess the genetic behavior of pre-harvest sprouting resistance. The combining ability (CA) demonstrated a higher proportion of additive genetic effects for sprouting resistance, because of higher variance of general and specific CA for both parameters under study. Doukkala-12 and BARS-09 showed increased pre-harvest sprouting resistance in their F₁ descendants.     

旱作技术对水稻中期群体结构的影响

利用三因素二次回归旋转组合设计探索水稻旱种的施氮量、基肥施氮比例及点播密度对水稻抽穗期群体的有效穗、单茎重的影响。结果表明:适宜的施氮量、基肥施氮比例及点播密度将形成抽穗期群体适宜的有效穗、较高的单茎重和茎鞘重/叶重比值。通过改进旱作技术,可使旱作水稻群体形成适宜的有效穗,个体充分生长,并促进抽穗前群体合成的净光合物质由叶流向茎,形成壮蘖、大穗,并控制叶的生长而实现高产。     

戊唑醇与羟菌唑对小麦赤霉病的防治效果及对小麦产量的影响

通过室内和田间药效试验,研究了新型三唑类杀菌剂戊唑醇与羟菌唑对小麦赤霉病的防治效果。温室盆栽试验结果表明:25%的戊唑醇(3.15mL/L)、6%的羟菌唑(3.75mL/L)可有效控制赤霉病菌在小麦穗部小穗之间的扩展,防效高于多菌灵常规用量。田间药效测定结果表明:与对照相比,接种前2d喷药与接种后2d喷药,2001年,戊唑醇可使小麦赤霉病病情指数分别减少80.32%和70.64%,产量增加12.95%与8.74%;羟菌唑可使小麦赤霉病病情指数减少80.5%和68.0%,产量增加11.41%和11.45%;2002年,在小麦赤霉病严重发生的情况下,戊唑醇能使小麦赤霉病病情指数减少76.47%和78.67%,羟菌唑能使小麦赤霉病病情指数减少82.06%和81.89%,产量增加极显著。说明这2种药剂可以作为防治小麦赤霉病的替代品种。     

绵阳26号小麦丰产稳产性研究

用AMMI模型对绵阳26号小麦的丰产、稳产性进行分析,发现其产量显著高于对照品种,并且具有稳产、适应性广、综合性状好等特性。其高产稳产的主要原因之一是穗、粒、重自身水平高,二是源、流、库协调,三是具有良好的冠层结构。产量构成因素中,千粒重和有效穗对绵阳26号的产量贡献和影响最大。     

小麦产量三要素与产量的通径和灰色关联度分析

选用2008—2014年河南省生产上种植面积前15位的小麦品种和部分区域试验或生产示范表现较好的品系,分别采用灰色关联度分析和通径分析2种方法对小麦穗数、穗粒数、千粒质量与产量的相互关系进行分析,并比较了2种分析方法的差异,以期为今后相关研究分析方法的选择提供参考。结果表明,对产量三要素数据分别进行初值化、区间化、均值化处理后,产量三要素与产量的关联度大小顺序各不相同,分别表现为千粒质量穗粒数穗数、穗粒数穗数千粒质量、穗粒数千粒质量穗数;而通径分析结果和前人的研究结果更加一致,产量三要素与产量的相关性表现为穗数穗粒数千粒质量。综上,灰色关联度分析由于受数据转换方法的影响,试验结果波动较大,而通径分析所得结果更加稳定,因此,在进行试验因素相关程度分析时应优先选择通径分析方法。     

Polyester fiber: from its invention to its present position

The use of polyester fibers has grown more rapidly than that of any other man-made fiber. Many factors have contributed to this growth. Polyester's unique physical properties of strength, high modulus, elasticity, and durability are the basis for its success. The tailorability of the fiber makes it possible to generate a whole family of property variants for a wide variety of end uses. The ready availability and low cost of the raw materials, the continuing advances in polymerization technology, and the versatility of the melt spinning process have also been major factors in establishing polyester as the leading man-made fiber. New end uses have had a major impact on the growth of polyester. Most notable was the introduction of durable press fabrics for clothing and home furnishings. The consumer preference for easy-care fabrics and garments makes the durable press area one of continuing growth. Two relatively new areas where growth is expected to continue at a rapid rate are tire cord and textured knits for women's and men's outerwear.     

不同留果穗数对戈壁设施番茄光合特性、产量及品质的影响

【目的】 研究新疆南疆地区戈壁日光温室内不同番茄留果数对叶片光合特性与果实品质的影响,获得戈壁温室番茄生产的经济最适留果穗数。【方法】 以NS3389番茄作为试验材料,设置4种留果穗处理(T₃:留3穗果;T₄:留四穗果;T₅:留五穗果;T₆:留六穗果),测定各处理下,番茄叶片光合特性、植株产量、以及果实品质,筛选出综合效益较优的戈壁设施番茄留果数。【结果】 除T₃和T₆处理外,不同留果穗数的番茄功能叶片中光合色素含量普遍随留果数增加而增加,T₄和T₅处理下的番茄叶片的净光合速率(P_N)显著高于其他处理,而T₅和T₆处理下的叶片气孔导度(G_S)、胞间CO₂浓度(C_i)、以及蒸腾速率(T_r)数据却较高。单株果实产量T₆处理组数据显著高于其他处理,而T₅和T₆处理的设施年产量最高。果实果形指数各处理间无显著差异,可溶性固形物、抗坏血酸(VC)以及番茄红素的果实品质指标T₄和T₅处理显著高于其他处理。【结论】 新疆南疆地区戈壁温室番茄生产较适合采用4穗和5穗的留果模式。     

纤维素酶协同机械法制备微/纳纤丝

以杨木纸浆纤维为原料,采用纤维素酶水解法协同机械处理法制备出微/纳纤丝（Micro/Nanofibrils）.酶处理制备微/纳纤丝的影响因素按大小依次为：时间、加酶量、料液比.最佳工艺条件：处理时间为36 h,加酶量30 FPU,料液比为1∶40.酶解后纤维的结晶度为84.2％,纤维素含量为95.26％,再经过纤丝进行超声和高压均质间歇式处理来制备微/纳纤丝.从SEM图可以看出,纤丝表面起毛、分丝帚化,次生壁中层S2上微纤丝暴露,分离出了细小纤维.纤维的直径分布在25～55 nm,宽度方向已经达到纳米级纤丝要求.     

福建省大麦品种区试结果分析及今后生产和育种方向

“七五”至“九五”期间 ,福建省进行了三轮大麦品种区试。结果表明 :大麦品种产量不断提高 (从“七五”平均 14 4 .0kg/u提高到“九五”平均 2 4 2 .4kg/u) ,穗数增加 ,千粒重提高 ,向多穗大粒和大穗大粒方向发展 ,抗白粉病能力增强 ,新育成品种多表现抗白粉病 ,株高和生育期适宜 ,但稳定性尚需进一步提高 ,通过区试筛选出丰产品种莆大麦 4号、闽诱 3号 ,丰产稳产品种闽麦 0 6 ,丰产抗白粉病品种莆大麦 5号、莆大麦 7号和闽麦 0 2等。从区试结果分析认为 :今后福建大麦育种目标应该是 :中熟、中秆、高产、稳产、抗逆力强 ,质优。育种的方向和道路是走多穗大粒或大穗大粒道路