Nitric oxide protection against adriamycin-induced tubulointerstitial injury

It is well known that oxidative stress is related to the pathogenesis of adriamycin (ADR) nephropathy. However, it is unclear how nitric oxide (NO) is associated with the pathophysiological process after ADR administration. The NO level in a kidney homogenate was assayed by electron paramagnetic resonance (EPR) spectrometry using a direct in vivo NO trapping technique after ADR administration. N-(3-(aminomethyl)benzyl)acetamidine (1400W) was used as a specific, inducible nitric oxide synthase (iNOS) inhibitor. The levels of NO after ADR administration gradually increased for 6 h and then decreased until 24 h after ADR administration. The fractional excretion of Na (FE_Na) in the urine was elevated in the ADR group on day 1. Pre-treatment of the animals with 1400W attenuated the increase in NO levels despite further elevation of FE_Na. These findings suggest that iNOS-derived NO does not produce a harmful effect but rather protects the ADR-treated kidney against sodium excretion.     

Metabolism of Ethanol to 1-Hydroxyethyl Radicals in Rat Liver Microsomes: Comparative Studies with Three Spin Trapping Agents

Metabolism of ethanol to 1-hydroxyethyl radicals by rat liver microsomes was studied with three nitrone spin trapping agents (POBN, PBN, and DMPO) under essentially comparable conditions. The data indicate that POBN was the superior spin trapping agent for 1-hydroxyethyl radicals, and that DMPO was least efficient. Addition of deferoxamine completely prevented detection of 1-hydroxyethyl radicals with PBN or DMPO, but caused only 50% decrease in EPR signals when POBN was the spin trap. However, superoxide dismutase only decreased 1-hydroxyethyl radical formation when POBN was the spin trap. Other experiments demonstrated that POBN was the most effective of these nitrones for reduction of Fe(III) in aqueous solutions. Furthermore, 1-hydroxyethyl radical adducts were formed when POBN was added to mixtures of ethanol, phosphate buffer, POBN and FeCl₃, but this effect did not occur with either PBN or DMPO. Thus, these data indicate that undesirable effects of POBN on iron chemistry may influence results of spin trapping experiments, and complicate interpretation of the resulting data.     

Monitoring mammals in the Caxiuanã National Forest,Brazil – First results from the Tropical Ecology,Assessment and Monitoring (TEAM) program

The need for long-term biodiversity monitoring using standardized protocols led to the creation of the Tropical Ecology, Assessment and Monitoring (TEAM) initiative. At some 50 field stations in tropical forests around the world, TEAM will monitor various taxa such as ants, birds, butterflies, medium and large terrestrial mammals, primates, litter fall, and trees, as well as landscape change in nine tropical biodiversity hotspots and three tropical wilderness areas. The TEAM terrestrial mammal program calls for using a grid of camera phototraps to monitor long-term trends in densities and occupancy rates of species that can or cannot be uniquely identified, respectively. We describe the TEAM camera phototrapping program and provide results for the first TEAM site–Caxiuanã National Forest in northern Brazil. An intensive one year camera trapping effort was carried out to determine which months were most suitable for long-term monitoring. Fifteen species of medium and large terrestrial mammals and two large birds were recorded, including three xenarthrans, five carnivores, one perissodactyle, three artiodactyles, two rodents, and one marsupial. The medium and large terrestrial mammal diversity was well represented during two consecutive wet and dry months, respectively. We also recorded activity patterns for all species photographed by our camera traps more than 10 times.     

Using species accumulation curves to estimate trapping effort in fauna surveys and species richness

Abstract The shape of species accumulation curves is influenced by the relative abundance and diversity of the fauna being sampled, and the order in which individuals are caught. We use resampling to show the variation in species accumulation curves caused by the order of trapping periods. Averaged species accumulation curves calculated by randomly assigning the order of trapping periods are smooth curves that are a better estimate of species richness and a more useful tool for determining the trapping effort required to adequately survey a site. We extend this concept of randomly resampling the trapping period to show that randomizing the number of individuals caught for each species over the number of collection periods (e.g. days) can provide an accurate estimate of the averaged species accumulation curve. This is particularly useful as it enables an accurate estimation of the proportion of the total number of species caught in an area during a survey from information on the number of individuals caught for each species and the number of trapping periods, and is not dependent on having knowledge of the trapping period in which each individual was caught. This calculation also enables an assessment to be made of the adequacy of fauna surveys to report a species inventory in environmental impact assessments when only a species list and relative abundance data are provided.     

整合昆虫发育生物学和果蝇遗传学来研究昆虫发育与变态

成熟动物(昆虫)个体大小主要由生长持续时间和生长速度2个因素所决定。蜕皮激素和保幼激素协同调控昆虫发育变态,并决定昆虫生长持续时间;胰岛素、营养和细胞接触抑制等生长死亡信号及其传导途径控制细胞分裂、长大、分化、死亡,并最终决定昆虫的生长速度。最近研究成果表明,蜕皮激素信号和胰岛素信号相互影响,对昆虫个体大小起决定性的作用;脂肪体和营养代谢把这2条信号传导途径整合起来。科学家将会整合昆虫发育生物学和果蝇遗传学,抓住生长持续时间和生长速率2个关键因素,并以营养代谢和脂肪体为切入点来研究昆虫的发育变态。     

豆野螟成虫行为学特征及性信息素产生与释放节律

豆野螟Maruca vitrata (Fabricius)是一种严重的泛热带豆类蔬菜害虫。本文在（29±1）℃、相对湿度75%～80%、光周期14L∶10D条件下研究了豆野螟成虫的羽化、交尾行为以及雌蛾性信息素的释放节律。结果表明：其羽化行为全天可见,在雌蛾中,86%于暗期羽化; 在雄蛾中,73%于暗期羽化。雌雄蛾羽化行为在暗期第4、5和8 h差异达到显著 (t>4; P<0.05)。交尾活动发生在暗期19：00到5：00之间,交尾持续时间最短约为20 min,最长约为90 min,3日龄进入暗期第5 h具有最高的交尾率。1、6和7日龄成虫具有单个交尾高峰,2到5日龄成虫具有两个交尾高峰。同一日龄成虫交尾在暗期前半段平均花费的时间要明显高于在后半段花费的时间。低龄和高龄的成虫用于交尾的时间明显高于中龄的性成熟成虫。成虫的开始交尾时间随着日龄的增加逐渐前移。雄蛾对进入暗期后第5 h和第9 h处女雌蛾的性腺提取物和空气收集性信息素的触角电位反应最强,对 3日龄处女雌蛾的性腺提取物和空气收集性信息素的触角电位反应最强。处女雌蛾田间诱蛾试验表明：23：00-01：00为诱蛾高峰期,3日龄处女雌蛾的诱蛾效果最好。该蛾的羽化、交尾及性信息素产生与释放均存在节律上的一致性。雌蛾的性信息素释放的时间较长,见于整个暗期,然而交尾行为发生时间较短,主要发生于两个交尾高峰之间。     

烟蚜茧蜂寄生对烟蚜生长发育和繁殖的影响

【目的】为探究烟蚜茧蜂Aphidius gifuensis对烟蚜Myzus persicae寄生后烟蚜生长发育和繁殖影响及其在烟蚜防控中的作用。【方法】采用室内叶片培养皿法,测定了不同龄期烟蚜(1-4龄若蚜及成蚜)被烟蚜茧蜂寄生后烟蚜当代(F₀)及后代(F₁)的发育历期、寿命、产仔量。【结果】烟蚜1龄若蚜被烟蚜茧蜂寄生后,1龄若蚜历期受到显著影响,较未被寄生对照缩短了0.65 d (33.00%),而2-4龄若蚜期和成蚜历期未受显著影响;2龄若蚜被寄生后,4龄若蚜和成蚜历期均受到显著影响,较未被寄生的对照分别缩短了1.50 d (100.00%)和0.83 d (100.00%),而2和3龄若蚜期未受显著影响;3龄若蚜被寄生后,4龄若蚜和成蚜期均受到显著影响,较未被寄生对照分别缩短了1.50 d (100.00%)和0.83 d (100.00%),而3龄若蚜期未受显著影响。2龄若蚜被寄生后烟蚜的寿命和产仔量均受到显著影响,寿命较未被寄生对照缩短了8.39 d(54.00%),每雌产仔量较未被寄生对照减少了48.67头(100.00%)。此外,2-3龄若蚜被寄生后其后代(F₁)1龄若蚜历期受影响最大,较未被寄生烟蚜后代1龄若蚜期缩短了0.80 d(40.00%),其F₁代平均寿命较未被寄生烟蚜后代平均寿命延长了5.72 d(41.20%),但其产仔量与对照差异不显著。【结论】不同龄期烟蚜被烟蚜茧蜂寄生后,其发育历期和寿命比未被寄生的缩短,产仔量比被未寄生的少,但其F₁代平均寿命比未被寄生后代烟蚜的长且其产仔量未受显著影响。当代2龄若蚜期是控制烟蚜增长的关键时期。这些结果对确定烟蚜茧蜂防治烟蚜适期及认识其机理具有重要参考意义。     

温度对取食玉米籽粒桃蛀螟生长发育、存活和生殖的影响

为了明确不同温度对取食玉米籽粒桃蛀螟生长发育、存活和生殖的影响,本研究依据年龄-龄期两性生命表理论计算了在21、24、27和30 ℃下取食玉米籽粒的桃蛀螟种群的生命表参数,并基于这些参数预测了未来80 d的种群动态。结果表明: 在21、24、27和30 ℃下桃蛀螟均能完成1个世代,随着温度升高,各阶段的发育历期缩短,且温度间差异显著。24 ℃下的平均单雌产卵量最高(116.7粒),成虫前期存活率最高(84.7%),雌虫占比最高(0.46),均显著高于其他温度。24、27、30 ℃下种群的内禀增长率分别为0.1059、0.1101、0.1045 d^-1,周限增长率分别为1.1117、1.1164、1.1102 d^-1,处理间差异不显著,但均显著高于21 ℃处理。21、24、27和30 ℃下的净增殖率(R₀)分别为17.3、53.7、36.9、19.8个后代个体,其中24 ℃时的R₀最高且显著高于其他温度处理。表明桃蛀螟种群在24～27 ℃下的存活率高、繁殖力大、雌性占比较高,是其生长发育、生存和繁殖的适合温度。     

Effects of starvation on death‐feigning in adult Eucryptorrhynchus brandti (Coleoptera: Curculionidae)

In insects, death‐feigning is an effective defence strategy. Eucryptorrhynchus brandti, a major borer pest in China, has a weak flight ability and exhibits obvious death‐feigning behaviour when disturbed. Despite a large number of studies of its biological and ecological properties as well as control methods, the death‐feigning behaviour has not been specifically described. In laboratory conditions, we recorded the survival rate under starvation and feeding conditions and evaluated the effect of starvation on the duration and occurrence of death‐feigning. In a continuous experiment, we examined variation in the death‐feigning duration every day over 7 day. Then, we evaluated the effects of starvation for 3, 6 and 9 day in a non‐continuous experiment and further observed variation in the death‐feigning intensity. We found that starvation significantly affected the survival rate. Survival time was significantly longer in the starvation group than in the feeding group, and females had longer survival times than males (female: 14 day, male: 8 day). In the continuous experiment, starved E. brandti had the longest duration of death‐feigning at 2 day, followed by a significant decrease. In the non‐continuous experiment, the duration and proportion of death‐feigning decreased significantly as the duration of starvation increased and were significantly lower than feeding. These observations suggest that starvation is a non‐negligible factor in the death‐feigning behaviour of E. brandti adults, facilitating the interpretation of future ecological and behavioural data of thanatosis.     

Delayed sleep/wake rhythm and excessive daytime sleepiness correlate with decreased daytime brain activity during cognitive task in university students

Insufficient sleep and irregular sleep/wake rhythm are common problems among university students. We investigated the effect of sleep/wake rhythm and excessive daytime sleepiness (EDS) on the cortical oxygenation as measured by near-infrared spectroscopy (NIRS) and cognitive performance in university students. Peak- and integral values by a word fluency task were measured with NIRS. EDS was evaluated by the Epworth sleepiness scale (ESS), and performance function was evaluated using N-back task. Peak cerebral oxygenation was significantly correlated with ESS, bedtime, wake-up time, and median time of sleep. Accuracy on 2-back task was significantly correlated with integral value. Peak- and integral values were significantly lower, and bedtime and median time of sleep were significantly delayed in the EDS group than in the non-EDS group. EDS accompanied by delayed sleep/wake rhythm and short sleep duration may play an important role in decreasing daytime brain activity and cognitive performance.