FISH ASSEMBLAGE RESPONSES TO DIFFERENT SECONDARY CHANNEL DESIGNS IN THE LOWER MISSISSIPPI RIVER,U.S.A.:A TEMPLATE FOR RIVER RESTORATION

The lower Mississippi River(LMR) has been heavily modified for multiple human purposes such as navigation, flood control, and bank stabilization. However, the LMR simultaneously supports a diverse fish fauna that includes recreational and commercial fisheries. Due to river training and diversion structures constructed during the past 80 years, the historic characteristics of the LMR have been drastically altered and have likely influenced fishes and fisheries in the system. One common restoration measure used throughout the LMR has been to "notch" wing-dike structures that close secondary(side) river channels. Dike notching allows year-round flows through secondary channels, which enhances habitat diversity and promotes biological productivity at the ecosystem scale. Although notching is presumed good for LMR fishes and other biota, few studies have examined its effects on fish assemblages. In this study, fish assemblages were sampled at seven LMR secondary channels spanning from river kilometer(rkm) 628(Louisiana-Mississippi, U.S.A.) upstream to rkm 1504(Missouri-Kentucky, U.S.A.). Four secondary channels were termed "permanent"(i.e.,with notched dikes) while three secondary channels were termed "temporary"(i.e., without notched dikes).Fishes were sampled by boat-mounted electrofishing conducted during falling and low stages from1995—1997. Fish assemblages differed between permanent and temporary secondary channels, and varied somewhat between falling and low stages. Gizzard shad(Dorosoma cepedianum), threadfin shad(D. petenense), and white bass(Morone chrysops) demonstrated consistent preferences for low-current conditions associated with temporary secondary channels. Conversely, blue catfish(Ictalurus furcatus), flathead catfish(Pylodictis olivaris), and freshwater drum(Aplodinotus grunniens) were more associated with permanent secondary channels. Future restoration strategies in the LMR should consider dike notching and resultant maintenance of permanent secondary channels in selected river reaches. However, temporary secondary channels also contain unique fish species, and also appear to be important sites of riverine primary production. Restoration strategies should consider a balance of both secondary channel types, which should support the greatest biodiversity for the LMR ecosystem.     

Applications of stem cells and bioprinting for potential treatment of diabetes

Currently, there does not exist a strategy that can reduce diabetes and scientists are working towards a cure and innovative approaches by employing stem cellbased therapies. On the other hand, bioprinting technology is a novel therapeutic approach that aims to replace the diseased or lost β-cells, insulin-secreting cells in the pancreas, which can potentially regenerate damaged organs such as the pancreas. Stem cells have the ability to differentiate into various cell lines including insulinproducing cells. However, there are still barriers that hamper the successful differentiation of stem cells into β-cells. In this review, we focus on the potential applications of stem cell research and bioprinting that may be targeted towards replacing the β-cells in the pancreas and may offer approaches towards treatment of diabetes. This review emphasizes on the applicability of employing both stem cells and other cells in 3 D bioprinting to generate substitutes for diseased β-cells and recover lost pancreatic functions. The article then proceeds to discuss the overall research done in the field of stem cell-based bioprinting and provides future directions for improving the same for potential applications in diabetic research.     

Behavioral and neural auditory thresholds in a frog

Vocalizations play a critical role in mate recognition and mate choice in a number of taxa, especially, but not limited to, orthopterans, frogs, and birds. But receivers can only recognize and prefer sounds that they can hear. Thus a fundamental question linking neurobiology and sexual selection asks-what is the threshold for detecting acoustic sexual displays? In this study, we use 3 methods to assess such thresholds in tdngara frogs: behavioral responses, auditory brainstem responsesz and multi unit electrophysiological recordi ngs from the midbrain.We show that thresholds are lowest for multiunit recordings (ca. 45 dB SPL), and then for behavioral responses (ca. 61 dB SPL), with auditory brainstem responses exhibiting the highest thresholds (ca. 71 dB SPL). We discuss why these estimates differ and why, as with other studies, it is unlikely that they should be the same. Although all of these studies estimate thresholds they are not measuring the same thresholds;behavioral thresholds are based on signal salienee whereas the 2 neural assays estimate physiological thresholds. All 3 estimates, however, make it clear that to have an appreciation for detection and salienee of acoustic signals we must listen to those signals through the ears of the receivers.     

中国省级行政区生态环境可持续性评价

从自然条件、人类胁迫、生态环境效应和社会响应4个主题出发,构建了包含28个指标的中国省级行政区生态环境可持续性评价指标体系,并通过专家调查和层次分析法为各主题层中的指标赋权.分别用各主题层中的指标和对应的权重,采用加权平均法构建自然条件(NSI)、人类胁迫(HPI)、生态环境效应(EEI)和社会响应(SRI)4个分指数,然后用这4个分指数通过灰色关联法构建综合生态环境可持续性指数(CEI),对我国各省级行政区生态环境可持续性进行评价.同时论文通过主成分分析法和相关分析法分析造成各指数地域差异的主导因素和评价中指标赋权的合理性.最后以4个分指数作为变量,采用快速样本聚类法对我国31个省级行政区进行聚类分析.评价结果表明,2003年我国各生态环境指数存在显著的地域差异.自然条件从东南到西北呈明显的由优到劣的过渡趋势,降雨量、年均气温、森林覆盖率和水网密度4个指标是导致地域差异的主导因素;人类胁迫东部发达地区明显高于西部和中部地区,同一个地区经济发展水平存在显著的正相关;生态环境效应西北地区最为显著,同各地区自然条件存在显著的负相关,在人类活动干扰下,自然条件差的地区更容易发生生态损害与退化;社会响应无明显的地域分析规律,各地区经济发展水平对其有一定影响,但并非决定性因素.区域综合生态环境可持续性由区域NSI、HPI、EEI和SRI共同决定,综合评价得到2003年我国各省级行政区生态环境可持续性排序情况,其中生态环境可持续性最强的几个地区为海南、云南、广西、江西等地,最弱的几个地区为内蒙古、宁夏、上海、西藏、新疆等地.最后,聚类分析把我国31个省级行政区聚为生态环境特点各异的六大类,可以促进我国生态环境的分类管理.     

A lubricant boundary condition for a biological body lined by a thin heterogeneous biofilm

We study the asymptotic behavior of an incompressible viscous fluid flow in a biological body lined by a thin biological film with a cellular microstructure,varying thickness,and a heterogeneous viscosity regulated by a time random process.Let ting the thickness of the film tend to zero,we derive an effective biological slip boundary condition on the boundary of the body.This law relates the tangential fluxes to the tangential velocities via a proportional coefficient corresponding to the energy of some local problem.This law describes the ability of the biological film to function as a lubricant reducing friction at the wall of the body.The tangential velocities are functions of the random trajectories of a finely concentrated biological particle.     

猛犸雪原

正我对东北的了解和向往,最早来自上世纪70年代初期读过的描写北大荒知青生活的小说《征途》。我最感兴趣的是书中描述的东北的自然风光和动物植物:"遮天蔽日的红松林,尽管被大雪覆盖,但远远望去,依然是郁郁苍苍。朔风吹过,发出万马奔腾的松涛声。那一望无际的桦树林,好像千百株银枝玉树,俊秀挺拔地屹立在冰天雪地中";"咱这疙瘩呀,是‘棒打獐子瓢舀鱼,雉鸡飞到饭锅里’。汽车在公路上撞死几个挡道的狍子,跟你们南方碾死一条蛇一样不稀     

我国近代发酵工业的先驱——金培松

金培松(又名金柏卿,英文名Pei-sung King)1906年10月30日生于浙江省东阳后岑山村.童年时他是在农村渡过,牛角挂书,放牛识字.1919年进入东阳县长山小学,1923年高小毕业,入东阳县城初级中学,3年后毕业,考入浙江省立第一中学高中部,1年后因家庭经济困难辍学,1927年9月以高中肄业学历被上海劳动大学农学院农艺化学系录取,1931年毕业.     

Species Account of Anura ns from the Western Slope of Mt. Kita nglad,Mindanao Island,Philippines

The Mt. Kitanglad Range is one of the country’s important key biodiversity sites;however, information about anuran diversity in this protected area remains depauperate. Herein we provided accounts of anuran species from high-elevation forests, in three sites of the western slope of Mt. Kitanglad range. The combined belt-transect sampling and microha bitat searches accounted for 13 species representing five families. The most represented family was Rhacophoridae with five representative species of the genus Philautus. Twelve out of the 13 species documented in the current survey are endemic. Four previously unaccounted species(Pelophr yne brevipes, Pulchrana grandocula, Sanguirana mearnsi, and Philautus surrufus) were added and brought the total anurans known from Mt. Kitanglad to 26 species. Most of the species were also recorded in forested sites, suggestive of their lesser affinity to non-forested ecosystems. The additional species detected during our survey may also imply that full understanding of anuran diversity of Mt. Kitanglad remains far from complete.     

2008年春鄱阳湖区斑背大尾莺状况

2008年1月下旬至2月上旬在中国南方广大地区发生冻雨雪灾害,给在鄱阳湖区越冬的斑背大尾莺(Locustella pryeri)带来不利影响,据3月上旬的调查,原本在江西鄱阳湖南矶湿地国家级自然保护区内广泛分布的斑背大尾莺已变得十分稀少.     

圈养条件下金钱豹交配行为的初步观察

2005年3月至2006年3月,采取所有事件取样法,对成都动物园5只(2雄,3雌)圈养金钱豹(Panthera pardu)进行观察,旨在了解圈养金钱豹的交配情况。记录交配行为1 174次。结果显示,圈养金钱豹全年皆可发情。具有明显的交配模式,交配姿势仅有一种,为背腹式。平均交配持续天数为(4.75±1.26)d。昼夜都有交配行为,但白天交配次数较夜间多。日交配的高峰发生在08:00～10:00时,不同的雄性个体出现的交配高峰日不同。平均交配持续时间为(7.48±1.22)s。在交配持续时间(P=0.000)、总交配次数(P=0.04)上,不同的雄性个体间存在显著性差异;而同一雄性在与不同雌性交配时,其持续时间无显著差异。金钱豹交配的特点为,交配的频次多,但每次交配持续时间短。     

Mating Behavior of Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae): Potential for Outbreeding in a Predominantly Inbreeding Species

The mating behavior of the quasi-gregarious egg parasitoid Trissolcus basalis (Wollaston) was investigated under field conditions. Trissolcus basalis has female-biased sex ratios and is a protandrous species, with males emerging 1–2 days before females. Males competed aggressively for control of the egg mass, with one male assuming dominance and control of the egg mass, although changes in dominance occurred at least once on each egg mass observed. Typical mating behavior involved the dominant male mating his sisters immediately upon their emergence from the egg mass. These behaviors are characteristic of an inbreeding species that manifests local mate competition. However, several aspects of the mating behavior of T. basalis are inconsistent with that of an inbreeding species. Over 18% of emerging females were not mated by the dominant male upon emergence, 13% of females were not observed to be mated at all and may have left their natal site as virgins, 25% of females were mated multiple times and sometimes by multiple males, females remained near the natal site for up to several hours after emergence before emigrating, and males dispersed away from the natal site during female emergence. Trissolcus basalis may be a predominantly inbreeding species but its emergence and mating behavior suggest that low-frequency outbreeding is also likely to occur.     

栎旋木柄天牛生殖行为研究

为了阐明栎旋木柄天牛Aphrodisium sauteri Matsushita生殖行为的方式和特点,寻找有效的防治手段,本试验观察了栎旋木柄天牛的生殖行为,并在林间尝试了成虫诱集。结果表明:雌雄成虫之间表现出较强的吸引作用,近距离时雌雄虫可相互吸引,而远距离时雌虫引诱力更强。室内试验中求偶时间会随着成虫的衰弱而增加。成虫交配主要发生于白天。羽化出孔后1～14日龄雌虫和2～13日龄雄虫均可多次交配。成虫一次完整交配平均需时70.12min,交配后保护平均仅用时3.86min。一次完整交配过程中,不同日龄成虫的交配历时、交配间隔历时及交配次数都存在差异,各日龄成虫的交配间隔历时均大于交配历时。交配或产卵经历对雄虫交配行为的影响明显大于雌虫。雌虫产卵前期平均为30.71h。雌虫每产1粒卵平均需时99.58s,并随日龄增长显著加长。每头雌虫平均每日产卵量和总产卵量分别为7.89和26.20粒。雌虫多在白天产卵,用产卵器触探树皮表面寻找合适的产卵部位。卵主要产于树皮裂缝和枝条疤痕内,一般每次产卵1粒,卵表面无覆盖物。     

Temporal and spatial quantitation of nesting and mating behaviors among mice housed in a semi-natural environment

Enhanced behavioral complexity may be observed when animals are tested in naturalistic environments and engaging in nonforced social interactions. For each of six experimental runs, different groups of five adult Swiss-Webster mice (four ovariectomized females and a single male) were maintained under 12h dark:12h light in a 122 x 122 x 30.5-cm open box containing six peripheral "nestboxes." On Day 1, females were released into the box first and their nesting behavior was observed. Two days later, each female was injected with estradiol benzoate and the male was introduced into the environment. Females were injected with progesterone (P) 48 h later and the animals were observed for an additional 14 h. Behaviors were recorded with a video camera suspended over the apparatus. Mating occurred only post-P and males always mated preferentially with certain females. The amount of nesting behavior per female on Day 1 correlated significantly with the number of times each female was mated by the male (r = 0.57, P < 0.005). In all but one run, the male ejaculated with the female who performed the most nesting behavior. While 63% of mating was in the open, 56% of nestbox matings resulted in female postmating darting to alternate nestboxes; in 19% of these cases, the female quickly returned to the mating nestbox and was mated there again. Direct approaches by females to the male and behaviors which affect pacing were observed. These behaviors have not been reported previously for mice and may provide additional endpoints for the exploration of hormonal and genetic influences on reproductive behaviors.     

四川梅花鹿繁殖行为

2006年4—12月和2007年3—11月在四川省铁布自然保护区观察和统计了野生梅花鹿的繁殖行为,包括发情交配、产仔、发情吼叫、爬跨及其昼夜节律行为等。结果表明,四川梅花鹿为季节性发情动物,发情交配行为发生在9月上旬至12月中旬,集中在10—11月(占(86.99±3.24)%)。四川梅花鹿发情交配日期最早见于9月8日,最晚为12月16日,跨度约90—100 d(±6 d,n=90)。雌鹿交配日期与其繁殖经历具有低度正相关性(Kendall's tau-b和Spearman's rho,0.3r0.5,P0.05),成体雌鹿交配日期稍微早于初次配种雌鹿。雄鹿发情吼叫和爬跨行为具有明显的昼夜节律性,各有2个高峰期(05:00—08:00和18:00—21:00),夜间有小节律的发情吼叫和爬跨时期。U-test检验表明发情吼叫频次和爬跨频率在昼夜间有极显著差异(P0.01)。雄鹿吼叫行为与其交配行为具有高度正相关性(Kendall's tau-b和Spearman's rho,0.8r1.0,P0.05),主雄、次雄和群外单身雄鹿的昼夜吼叫次数有极显著差异(P0.01)。雌鹿产仔期从4月下旬开始到7月下旬结束,集中在5—6月(占(91.51±4.96)%),产仔日期最早见于4月29日,最晚为7月28日,跨度约80—90 d(±5 d,n=130)。梅花鹿产仔日期与其分娩经历具有低度正相关性(Kendall's tau-b和Spearman's rho,0.3r0.5,P0.05),成体雌鹿产仔日期早于初次繁殖雌鹿。雌鹿每胎产1—2个幼仔,单双胎率分别为98.86%(±6.96%,n=129)和1.01%(±0.07%,n=1)。妊娠期和哺乳期梅花鹿采食行为分配占较大比率,其次是卧息和移动,哺乳期采食行为分配低于妊娠期,这与妊娠期正逢冬季,食物资源相对匮乏有关,而哺乳期恰逢夏季,植物生长旺盛,食物资源相对丰富。     

Mating behavior of the predatory mite <Emphasis Type="Italic">Kampimodromus aberrans</Emphasis> (Acari: Phytoseiidae)

The mating behavior of the predatory mite Kampimodromus aberrans was studied in the laboratory at a constant temperature of 25± 1 °C and a photoperiod of 16:8 (L:D). Forty pairs of newly emerged virgin females and unmated males, were maintained separately on leaf discs and their mating behavior, was observed continuously under a stereomicroscope. The mean time until first contact of female and male individuals was approximately 8.2 min. After the first contact the male moved to the top of the female’s dorsum and subsequently underneath her in approximately 1.7 min and then the paired mites walked around on the leaf surface for approximately 7.5 min. Afterwards, the mites remained still in the mating position, i.e. the male beneath the female for an average period of 230.5 min. After mating, most of the females had one spermatophore in one of their spermathecae, whereas a few had one spermatophore in both spermathecae.     

Mate choice and sexual conflict in <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> (Rotifera)

Male mate choice in Brachionus plicatilis is based on information from coronal receptors and contact chemoreception of a glycoprotein signal on the body surface of females. Male mating behavior is modulated by mating signal quality and strength, which determines male mating persistence and circling intensity. We probe the sensory abilities of males by better resolving their discrimination of female age. Males preferentially initiate mating with young females, but not too young. Males circle 0.2 h old females just hatched from resting eggs only about 1/2 as frequently as 12 h old females. Males are even more discriminating of females with whom they copulate, preferring 3 h old females significantly more than 0.2 h or 6 h old females. In contrast, males cannot distinguish between virgin females and those who have already copulated. Similarly, males circled and copulated with females hatching from resting eggs with equal frequency as those hatching from amictic eggs. The counterpoint to male mate choice is female resistance to mating. When males contact females, the females respond with one of four behaviors: no response, acceleration, foot flipping, or coronal retraction. In 65% of male–female encounters, there was no initial response by females. However, when males began circling females, females accelerated 11.1 times more often than when males were absent. The second type of evasive female behavior was foot-flipping, which tends to knock off males attempting to circle the female. In the presence of circling males, females performed foot-flipping behavior three times more often than in the absence of males. Coronal retraction, where they stop swimming and withdraw their corona, was observed less frequently than acceleration or foot-flipping, and there was no difference in the presence or absence of males. These data are interpreted in the context of sexual conflict, where the behaviors that optimize male and female fitness differ. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont & R. Rico-Martínez Advances in Rotifer Research     

低盐度海水和淡水对中华绒螯蟹性腺发育及交配行为的影响

研究了低盐度海水(盐度为15)和淡水(盐度为0)对中华绒螯蟹(Eriocheir sinensis,以下简称河蟹)性腺发育及交配行为的影响,并比较了河蟹交配和产卵前后的性腺指数及肝胰腺指数的变化。实验分为4组,分别为低盐度海水雌蟹组、淡水雌蟹组、低盐度海水雄蟹组和淡水雄蟹组。结果表明,(1)各组河蟹的成活率均在80%左右,无显著差异(P>0.05);(2)实验第15天、30天和45天时,低盐度海水雌蟹组的卵巢指数显著高于淡水雌蟹组(P<0.05),低盐度海水雄蟹组的性腺指数也略高于淡水雄蟹组,但差异不显著(P>0.05);(3)实验第30天时,低盐度海水雌蟹组的肝胰腺指数显著低于淡水雌蟹组(P<0.05),其余采样时间两组雌体间或两组雄体间的肝胰腺指数差异不显著(P>0.05),实验期间,两组雌体的肝胰腺指数均显著下降(P<0.05);(4)实验第45天,低盐度海水雌蟹组和雄蟹组实验个体全部能够交配,有66.7%的低盐度海水雌蟹组的个体交配后2 d内产卵,淡水雄蟹组有部分个体在低盐度海水中有发情行为;(5)低盐度海水组,雌蟹产卵后和雄蟹交配后的性腺指数均显著下降(P<0.05),但肝胰腺指数下降不显著(P>0.05)。     

Mating behavior ofXylotrechus pyrrhoderus Bates (Coleoptera: Cerambycidae) V. Female mounting behavior

Female mounting behavior was observed in the grape borerXylotrechus pyrrhoderus Bates (Coleoptera: Cerambycidae) under laboratory conditions. This behavior was directed towards either females (i.e., female homosexual mounting) or males. The female homosexual mounting was strongly elicited in females which had previously been allowed to fly. The frequency of this behavior was not related to the experience of mating. The investigation of the daily temporal pattern in female homosexual mounting activity indicated that the behavior most frequently occurred between 12∶00 and 16∶00, i.e., when females were searching for the pheromone-releasing males. Oviposition was also observed during this time interval. A detailed analysis revealed female mounting behaviors which are characteristic of male mounting behaviors, such as chasing conspecifics and synchronism of licking and abdominal bending. On the other hand, the frequency of male homosexual mounting was lower than that of females. Taken together with cases of other species previously reported, the expression of mounting behavior in females may be related to the evolution of the reproductive system, in which females approach their mates.     

半闭弯尾姬蜂羽化、交配及产卵行为观察

在22℃,相对度60％～70％的实验室条件下,研究了半闭弯尾姬蜂Diadegma semiclausum的羽化、交配与产卵行为。结果表明：半闭弯尾姬蜂蜂蛹从开始羽化到羽化结束历经4d,羽化高峰期出现在羽化的第3d,羽化数量为25头,占全部羽化数量的58．82％;第3d中羽化高峰出现在8：00～13：00,羽化数量为16．5头,占全天羽化数量的66．00％。半闭弯尾姬蜂交配过程大致分为3个阶段：准备阶段、交配阶段、结束阶段;交配后开始产卵,产卵过程大致分为寄主寻找和确定、穿刺和产卵、产卵结束和梳理。