广西防城发现黄嘴白鹭的繁殖种群

20 0 2年 3～ 8月 ,在广西防城万鹤山首次发现国家Ⅱ级重点保护动物黄嘴白鹭的繁殖种群 ,约 4巢 ,8只成鸟 1 4只雏鸟。黄嘴白鹭于该年 3月底 4月初迁来筑巢繁殖。巢材多为常绿、落叶阔叶树枯枝和松枝。窝卵数 4枚 ,卵为淡蓝青色。雌雄鸟轮流交替孵卵 ,孵化期 2 4 5 0± 1 5 0 ( 2 3～ 2 6)d ,孵化率1 0 0 %。育雏期 41± 2 ( 3 9～ 43 )d ,窝雏数 3 5 0± 0 2 9( 3～ 4)只 ,雏鸟成活率 87 5 0 %。食性主要为鱼( 77 84% )、虾 ( 1 6 76% )和青蛙 ( 5 40 % )。     

无锡太湖地区夜鹭及白鹭繁殖生物学研究

1999年 4～ 6月对分布在无锡地区的夜鹭 (Nycticoraxnycticorax)和白鹭 (Egrettagarzetta)的繁殖生物学进行了调查研究 ,调查地面积约 2 72 37 5m2 ,植被以马尾松 (Pinusmassoniana)和香樟树 (Cinnamomumhupehanum)为主。研究结果表明 :栖息地共有鹭巢近万个 ,平均密度为 0 36个 /m2 ,每棵树上平均巢数为1 0 6个 ,最多达 2 5个 /棵树 ;平均窝卵数夜鹭为 3 5 5枚 ,白鹭为 4 89枚 ;平均窝雏数夜鹭为 2 6 8只 ,白鹭为3 96只 ;孵化期白鹭为 1 9～ 2 1天 ,夜鹭为 2 2～ 2 3天 ;孵化成功率白鹭为 84 2 5 % ,夜鹭为 75 46 % ;白鹭雏鸟主要以小型鱼类和虾类为食 ,夜鹭雏鸟主要以鱼类和两栖类为食。     

青海湖鸬鹚繁殖习性的初步观察

1999年 4～ 7月和 2 0 0 0年 3～ 8月 ,对青海湖地区的鸬鹚繁殖过程进行了观察 ,初步掌握了鸬鹚的迁移、营巢、产卵、孵卵、育雏和扩散等生态习性。结果表明 :鸬鹚每年 3月中、下旬迁来青海湖繁殖 ,两性共同营巢 ,营巢期集中在每年 4月上旬至 6月中旬 ;产卵高峰期为 4月下旬至 5月中旬。平均卵重是(5 7 5± 2 0 2 )g ,卵的大小为 67 2 9mm× 40 2mm ,平均窝卵数为 (3 61± 0 3 4)枚。鸬鹚孵卵期为 (2 8 0 7±0 5 3 )d ,孵化期间的卵重损失 (Y)与孵卵天数 (X)之间的线性回归方程为Y =0 997-0 0 0 68X(r=0 990 ,df=8,P <0 0 1 )。     

两种雀形目鸟类孵化行为对子代质量的影响

对高寒草甸地面营巢的小云雀 (Alaudagulgula)和灌丛筑巢的黄嘴朱顶雀 (Acanthisflavirostris)繁殖方式的研究表明 :①小云雀孵化异步性较弱 (1d) ;平均卵重与产卵顺序不显著相关 ,但最后 1枚卵最重 ;出壳顺序与雏鸟生长率极显著正相关 (P <0 0 1) ;出壳顺序对幼鸟的雏期和离巢体重无显著影响 (P >0 0 5 )。②黄嘴朱顶雀孵化异步性较强 (2～ 3d) ;平均卵重与产卵顺序显著正相关 (P <0 0 5 ) ,最后 1枚卵最重 ,第 1枚次之 ;出壳顺序对雏鸟生长率、雏期和离巢体重均无显著影响 (P >0 0 5 )。结果分析表明 ,2种雀形目鸟类都选择了异步孵化和加强窝雏数对策的繁殖模式。     

新疆木垒波斑鸨的繁殖成功率

作者于 1998～ 2 0 0 0年 4～ 7月 ,采用野外直接观察、栖息地植被样方调查和无线电跟踪等方法对分布于新疆木垒的波斑鸨 (Chlamydotiundulatamacqueenii)种群的繁殖生态进行了初步观察与研究。考察中共发现45个巢、 84窝幼雏。研究结果表明 ,木垒波斑鸨有两个产卵高峰期 ,表明雌鸟第一次繁殖失败后可能再次产卵。雌鸟营巢成功率平均为 0 5 0 5。波斑鸨的窝卵数在 2～ 6枚之间 ,出现 4枚卵的频率最高。第一产卵期内的平均窝卵数 ( 4 0± 0 8枚 /窝 )大于第二产卵期内的平均窝卵数 ( 3 3± 0 8枚 /窝 )。木垒波斑鸨种群三年间卵孵化率分别为 0 84、 0 80和 1,繁殖成功率为 0 45 6。种群在繁殖期几乎不受人类活动干扰 ,巢卵及幼雏损失主要来自天敌捕食 ,如沙狐、大和棕尾等.     

新疆木垒波斑鸨营巢成功率的初步研究

1998年 4月中旬～ 7月中旬 ,对分布于新疆木垒的波斑鸨 (Chlamydotisundulatamacqueenii)种群的营巢成功率进行了初步考察与研究。考察中共发现 16个巢、2 5窝幼雏。每巢产卵 3～ 6枚 ,卵鲜重 (6 4 7± 5 8)g ,卵径为 6 0 9mm× 43 9mm。产卵有两个高峰期 ,表明雌鸟第 1次繁殖失败后可再次产卵。第 1产卵期的巢卵数为(4 1± 0 8)枚 ,第 2产卵期的巢卵数为 (3 5± 0 6 )枚。雌鸟营巢成功率为 77 5 %～ 87 5 % ,卵的孵化率为83 6 %。每窝内从破壳到具备飞行能力的幼雏数基本不变 ,表明繁殖雌鸟大都能将幼雏全部抚育到可以飞行的年龄     

四川南充市区白腰文鸟的巢址选择与雏鸟的生长发育

20 0 2年 1 1月～ 2 0 0 4年 4月在四川省南充市区内对白腰文鸟 (Lonchurastriata)的繁殖习性进行了研究。结果表明 ,白腰文鸟 2月下旬开始繁殖 ;影响巢址选择的主要因素 9种 ;雌雄参与筑巢 ,营巢期 5～ 6d;雌雄轮流孵卵 ,孵卵期 1 3～ 1 5d ,整个种群的孵卵高峰期在 4～ 6月 ,窝卵数 (5 .61± 0 . 78) (n =1 8)枚 ,孵化率 86 0 7% ;雌雄均参与育雏 ,育雏期 1 8～ 2 1d ,雏离巢率 82 43 % ,繁殖生产力 3. 0 1 ,育雏两个高峰期 :上午 8:0 0～ 1 0 :0 0时和下午 1 6:0 0～ 1 8:0 0时 ,日育雏次数 (1 2 . 77± 6 .0 7) (n =3 4) ,育雏时间间隔(0 . 96± 0 . 42 )h(n =1 61 ) ;雏鸟形态生长曲线呈“S”型。     

白鹭作为无锡太湖地区环境污染指示生物的研究

2000年4—6月对分布在无锡太湖地区的4种要鸟中的白鹭(Egretta garzetta)行为生态学及其生境污染状况进行了调查研究．调查地白鹭主要栖息树种包括马尾松(Pnus masson±ana)、香樟树(C±nnamomum hupehanum)、麻砾树(Quercus acut±ssema)、榆树(Ulmus prm±la)和杨梅树（Myr±ca rubra)．栖息地总面积为7hm^2,白鹭总巢数为4200个,每棵树平均0．38个．白鹭的孵化期为19—21d,卵重23．9±4．0g(n=41),平均卵大小(44．5±4．1)mm×(32．6±4．9)mm(n＝41),平均窝卵数5．02(2—8)枚,平均窝雏数3．86(2—7)只,孵化成功率为84．25％．对白鹭雏鸟左右跗Zhe的测量分析表明不对称性不显著(P>0．05)．白鹭雏鸟食物较小,繁殖期间主要以小型鱼类和虾类为食．污染物分析结果表明,白鹭卵中除例外,六氯苯、六六六、环二烯类、DDTs、DDE、PCBs、Cr、Hg和Pb均检测到．食物链(底泥-食物-白鹭雏鸟)中,有机杀虫剂和重金属都逐级富集．通过与相对无污染的鄱阳湖地区比较,太湖地区和鄱阳湖地区卵样品中的DDs(包括DDT、DDE和DDD)浓度最高(超过2μg·g^1),其它污染物浓度均较小．太湖地区白鹭卵中的DDTs、Cd和Cr浓度低于鄱阳湖地区,其它污染物浓度鄱阳湖地区均低于太湖地区．经比较分析,两地样品中有机氯杀虫剂、PCBs和各种重金属浓度都未达到影响白鹭繁殖成功率的阈值．     

四川南充市区火斑鸠的繁殖生态

20 0 2年 5～ 1 1月、2 0 0 3年 4～ 9月对南充市火斑鸠的繁殖生态进行了研究。结果表明 :4月下旬迁到 ,5月下旬开始繁殖 ;影响巢址选择的主要因素 6种 ;两性参与筑巢 ,营巢期 7～ 8d ;隔 2～ 3日产枚卵 ,窝卵数 ( 2 2 1± 0 0 9)枚 (n =1 9) ;雌雄轮流昼夜孵卵 ,日换孵两次 ,孵卵期 1 1～ 1 2d ,孵化率 92 86%;育雏可分三个时期 ,育雏高峰期每日 7:0 0、1 3 :0 0、1 8:0 0时左右 ,育雏期 1 7～ 1 8d ,雏离巢率 1 0 0 %,繁殖生产力1 86,种群育雏高峰期 7月和 8月上中旬 ;雏鸟于 1 7或 1 8日后离巢迁到郊外 ,9月下旬集群 ,1 0月中下旬迁飞。     

厦门鸡屿岛白鹭几种繁殖活动的观察

于 2 0 0 1年 3～ 7月采用颜色标记法 ,记录厦门白鹭保护区内鸡屿岛白鹭 (Egrettagarzetta)卵产出和孵出的顺序和时间 ,并称重卵和雏鸟。有 91 4 %的窝卵数为 4～ 5枚 ,产卵期 7 0± 1 9d ,出壳期 4 2± 1 4d ;卵孵化时间与产卵顺序显著负相关 ;不同产出顺序卵重无差异 ;不同孵出顺序雏鸟早期 (≤ 5d)发育无差异 ,之后差异显著 ,第 4出壳的雏鸟发育水平和成活率较低 ,而第 5出壳的雏鸟最低 ;亲鸟在产卵期的孵化是非连续的 ,而产卵结束后相对连续。如此 ,可以调节孵化时间 ,进而调控异步孵化的程度 ,使雏鸟在生长阶段形成适当的等级差别 ,以获得最大的繁殖收益。     

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.     

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     

On the Dependence of the Quadratic Risk of the Classical Predictor and the Prediction-Horizon

When constructing predictors on the basis of the linear model of time series of various indicators often the question arises on the dependence of forecasting accuracy and the changing prediction horizon. The dependency of the quadratic risk of the classical predictor and the time horizon is considered.     

中国植物区系与其它地区区系的联系及其在世界区系中的地位和作用

基于吴征镒将中国全部种子植物３２３８个属的分布区划分为１５个大类型和３４个变型的基础上,简要地讨论了中国植物区系与其它地区区系的联系,以及它在被子植物起源方面的作用。主要论点如下：（１）与热带亚洲区系的联系。这种联系主要通过第７类型（热带亚洲分布）及其５个变型来体现的。本文列举了１０个科,龙脑香料、狭义隐翼科、交让木科、五隔草科、五列木科、肉实树科、心翼果科、八宝树科、兰花蕉科和四数木科,来说明这