Caste-fate determination primarily occurs after adult emergence in a primitively eusocial paper wasp: significance of the photoperiod during the adult stage

Independent-founding paper wasps constitute a major group of primitively eusocial insects, and when caste-fate determination occurs in temperate species of these wasps, particularly regarding whether it occurs before or after emergence, remains unclear. No critical morphological differences occur between potential queens of the next generation (often called gynes) and workers in primitively eusocial insects. The gynes of temperate species are characterized by diapausing, and the nutrients available during the larval stage have often been believed to determine caste fate. Short days usually induce diapause in temperate nonsocial insects, although few investigations of the effects of day length on caste-fate determination in paper wasps have been conducted. By exposing individuals to different combinations of short and long days during the immature and adult stages, we show for the first time that short days during the adult stage (but not during the immature stage) facilitated caste-fate determination toward gynes in a paper wasp. Moreover, the decision to diapause partly depended on changes in the photoperiod during the pupal and adult stages. The size of the adult also affected caste-fate determination, with diapause more likely to occur in large adults, but this size effect did not occur when individuals were exposed to many short days during the pupal stage. In addition, all adults except for a small proportion of smaller individuals prepared for diapause under short days. These findings suggest that the photoperiod is a higher priority cue than adult size.     

The function of dart behavior in the paper wasp, Polistes fuscatus

Dominance behavior in Polistes wasps is a composite trait consisting of various discrete behaviors such as darts, lunges, bites, and mounts. The majority of these behaviors are considered aggressive, and these aggressive behaviors are considered to form a continuum from mild (e.g., darts) to severe (e.g., falling fights). In this paper we focus on darts, the most common of the dominance behaviors, and investigate their function in un-manipulated post-emergent colonies of the primitively eusocial wasp P. fuscatus. Here we show that darts are correlated with the more severe dominance behaviors, and that dominance ranks do not change with the addition or exclusion of darts. We find no correlation, however, between receiving darts and receiving more severe dominance behaviors. This result suggests that darts are not indicative of aggressive reinforcement of dominance, but rather may serve a different function. Our data suggest that the function of darts is to regulate activity on nests. Both foundresses and workers dart inactive workers significantly more often than by chance, and workers respond to a foundresss (but not a workers) dart by becoming less inactive. We also found that active workers who receive a dart from either a foundress or worker respond mostly by switching from one activity to another. Thus, our data suggest that darts are not aggressive behaviors, that foundresses use this signal to initiate activity, and that foundresses and workers both use the signal to regulate worker activity.     

The energetic costs of stereotyped behavior in the paper wasp, Polistes dominulus

Polistes wasps engage in many behavioral interactions. Although there has been debate over the meaning of these interactions, these stereotypical behaviors can be used to determine a colony’s linear dominance hierarchy. Due to the implicit relationship between behavioral and reproductive dominance, behavioral interactions are commonly used to distinguish the reproductively dominant alpha foundress from the beta foundress. It has been suggested that in order to maintain reproductive control, the alpha foundress is forced to remain at a physiologically constrained activity limit. This, in turn, may allow aggressive interactions to be used as determinants influencing reproductive partitioning between cooperating individuals. Energetic costs can place important limitations on behavior, but the energetic cost of the interactions has not previously been measured. To address this, we measured the CO₂ production of 19 non-nestmate pairs displaying interactive and noninteractive behavior. The rate of energy used during interaction behavior was positively associated with published rankings of aggression. However, our results indicate that interactions are not very energetically costly in Polistes, particularly when compared to the likely cost of foraging. These data suggest that maintaining reproductive dominance is not very energetically expensive for the dominant and that the dominant foundress expends energy at a lower rate than the subordinate foundress. Electronic Supplementary Material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Queen regulates biogenic amine level and nestmate recognition in workers of the fire ant, <Emphasis Type="Italic">Solenopsis invicta</Emphasis>

Nestmate recognition is a critical element in social insect organization, providing a means to maintain territoriality and close the colony to parasites and predators. Ants detect the colony chemical label via their antennae and respond to the label mismatch of an intruder with aggressive behavior. In the fire ant, Solenopsis invicta, worker ability to recognize conspecific nonnestmates decreases if the colony queen is removed, such that they do not recognize conspecific nonnestmates as different. Here, we tested the hypothesis that the presence of the colony queen influences the concentration of octopamine, a neuromodulator, in worker ants, which in turn has an effect on nestmate recognition acuity in workers. We demonstrate that queenless workers exhibit reduced brain octopamine levels and reduced discriminatory acuteness; however, feeding queenless workers octopamine restored both. Dopamine levels are influenced by honeybee queen pheromones; however, levels of this biogenic amine were unchanged in our experiments. This is the first demonstration of a link between the presence of the colony queen, a worker biogenic amine, and conspecific nestmate recognition, a powerful expression of colony cohesion and territoriality.     

Distribution and contamination of metals and biogenic elements in sediments from Zhifu Bay of the Yellow Sea, China

Metals and biogenic elements were analyzed from surface sediments of sixteen stations and a 32 cm core collected from Zhifu Bay in July 2009. High concentrations of biogenic silica (BSi) reflected the high diatom productivity in the Bay. Meanwhile, total organic carbon (TOC) in Zhifu Bay was mainly from terrestrial sources. All metals were lower than the marine sediment quality guidelines. Based on the vertical profiles of biogenic elements, there was a clear increase of TOC, total nitrogen (TN), and total phosphate (TP) between 1985 and 2000. TN concentrations decreased after the start of the operation of the sewage treatment plant in 1998; however TOC and BSi remained at high levels. Metal concentrations showed a general increase from the bottom to the top of the core. Most anthropogenic metals reached a maximum during 1996 and 2000, and decreased after the startup of the sewage plant; however, they have increased again recently. The results from correlation analysis and principal component analysis show that industrial pollution is the main source of Cd, Cr, Cu, Ni, Pb and Zn contamination in Zhifu Bay, and Yantai Port and ship transportation also contribute a lot to Cd, Cu, Hg, and Pb pollution.     

On the parental origin of the X's in a prenatally diagnosed 49,XXXXX syndrome

A 49,XXXXX fetus was detected in amniotic fluid cell cultures from a 39-year-old mother. On ultrasonography, growth retardation and bilateral radioulnar synostosis were found. Additional clinical manifestations were mild facial anomalies and hypoplastic ovaries depleted of oocytes. Molecular analysis showed that this aneuploidy arose by successive maternal non-disjunction.     

二氧化硫对大鼠离体心脏功能影响的机制研究

为了探讨二氧化硫(SO2)对心脏功能影响的机制,分别用10、300和1000μmol·L-1的SO2灌流大鼠离体心脏后,测定心脏组织中一氧化氮(NO)、超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽(GSH)含量以及心脏灌流液中肌酸激酶(CK)和乳酸脱氢酶(LDH)活性.结果表明,10、300和1000μmol·L-1的SO2均可使心脏组织中NO和MDA含量以及心脏灌流液中CK和LDH活性明显增加,而使SOD和GSH含量明显减少.较高浓度(300和1000μmol·L-1)的SO2可使心脏组织中Na+K+-ATP酶和Ca2+Mg2+-ATP酶活性明显下降.结论:SO2对大鼠离体心脏功能影响的作用机制与SO2对心脏组织的氧化损伤作用、心肌细胞膜Na+K+-ATP酶和Ca2+Mg2+-ATP酶活性降低及NO-cGMP信号转导通路有关.     

土壤四环素污染对小白菜幼苗生长发育的生态毒性

采用土培盆栽试验模拟研究了土壤四环素污染对小白菜幼苗生长发育的生态毒性.结果表明,1～100 mg/kg四环素暴露促进了小白菜的茎伸长,但抑制了小白菜的根伸长和鲜重.100 mg/kg四环素处理28 d后,小白菜根长抑制率达到36.0%,鲜重抑制率达到34.6%.随着四环素暴露时间的延长,100 mg/kg四环素处理的...     

Biosorption of copper and zinc by immobilised and free algal biomass, and the effects of metal biosorption on the growth and cellular structure of Chlorella sp. and Chlamydomonas sp. isolated from rivers in Penang, Malaysia

In this study, the biosorption of copper and zinc ions by Chlorella sp. and Chlamydomonas sp. isolated from local environments in Malaysia was investigated in a batch system and by microscopic analyses. Under optimal biosorption conditions, the biosorption capacity of Chlorella sp. for copper and zinc ions was 33.4 and 28.5 mg/g, respectively, after 6 hr of biosorption in an immobilised system. Batch experiments showed that the biosorption capacity of algal biomass immobilised in the form of sodium alginate beads was higher than that of the free biomass. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed that copper and zinc were mainly sorbed at the cell surface during biosorption. Exposure to 5 mg/L of copper and zinc affected both the chlorophyll content and cell count of the algal cells after the first 12 hr of contact time.     

贵州高原百花湖水库湖沼学变量特征及环境效应

为了揭示贵州高原百花湖水库湖沼学变量特征及其与突发性水质恶化的关系,对百花湖水库的水文、营养盐及相关理化因子进行了调查.结果表明：百花湖水库表层水温在10.2～27.0℃之间,4—9月形成分层,水体分层结构为单循环混合模式;总氮（TN）、总磷（TP）、叶绿素a（Chl.a）和透明度（SD）分别为1.60mg·L-1、0...     

Toxic effects of meothrin on the gill ultrastructure in grass carp, Ctenopharyngodon idellus

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Mitigation costs,distributional effects,and ancillary benefits of carbon policies in the Nordic countries,the U.K., and Ireland

This paper provides a survey of top-downmodelling analyses of carbon (C) abatementmitigation costs, distributional effectsand ancillary benefits in the Nordiccountries, the U.K. and Ireland. Specialemphasis is placed on the effects ofrevenue recycling and tax exemptions.According to the analyses, modestemissions reductions can be met withoutsubstantial costs for the countriesstudied, and a strong double dividend isfound in some analyses. The gross domesticproduct (GDP) or welfare effects are mostlyin the range of –0.4 and 1.2 percent whenC emissions are reduced by 20–30 per cent.Lowest costs are obtained without taxexemptions and with tax revenues used toreduce distortionary taxes. Ancillarybenefits are mostly in the range35–80/MgC^-1, i.e., about the same order ofmagnitude as the mitigation costs.Distributional effects are mostlyregressive, unless the tax revenues aredistributed in lump-sum fashion with equaltransfers to each household.     

Enhanced ozonation degradation of atrazine in the presence of nano-ZnO: Performance, kinetics and effects

Enhanced ozonation degradation of atrazine (ATZ) with nano-ZnO (nZnO) as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The results demonstrated that the combination of ozone (O₃) and nZnO showed an obvious synergetic effect and the ATZ degradation conformed to pseudo-first-order kinetics. An improvement of ATZ degradation efficiency by 41.8% and pseudo-first-order rate constant by more than a factor of four was obtained in the O₃/nZnO process after 5 min of reaction compared to O₃ alone. Meanwhile, the degradation efficiency of ATZ was gradually enhanced with increasing nZnO dosage and initial pH in the range from 3.0 to 8.0, and a higher amount of ATZ was degraded when the initial concentration of ATZ rose from 0.5 to 5 mg/L. Additionally, sulfate ion, chloride ion, nitrate ion and low concentrations of humic acid substances led to enhancement of the ATZ degradation. The notable decrease of ATZ removal efficiency observed in the presence of radical scavengers and the results of free radical tests indicated that OH is the dominant active radical species. The mechanism investigation demonstrated that the enhancement effect could be attributed to the introduction of nZnO, which could promote the utilization of O₃, enhance the formation of superoxide radical, and further accelerate the production of hydrogen peroxide and the generation of OH/O₂-.     

The effects of different predator species on antipredator behavior in the Trinidadian guppy, Poecilia reticulata

Different types of predators often elicit different antipredator responses in a common type of prey. Alternatively, some prey species may adopt a general response, which provides limited protection from many different types of predator. The Trinidadian guppy, Poecilia reticulata, is faced with a wide range of different predators throughout its range and is known to display varying levels of antipredator behavior depending on the predator assemblage. Pike cichlids, Crenicichla frenata, are regarded as the primary aquatic guppy predator in streams in the northern mountain range in Trinidad. As such, they are seen to be responsible for many of the differences in morphology, life history traits, and behavior between guppy populations from areas with few predators and those from areas with many pike cichlids. In this study we investigated how guppies responded when faced with different predator species using three common aquatic predators. We exposed shoals of ten guppies to one out of four treatments: no predator (control), pike cichlid, acara cichlid (Aequidens pulcher), and wolf fish (Hoplias malabaricus); and we made behavioral observations on both focal individuals and the shoal as a whole. Guppies showed significantly greater levels of predator inspection and shoaling behavior, foraged less, spent more time in the surface water, and stayed in significantly larger shoals when faced with pike cichlids than in other treatments. We discuss these results in the context of multiple predator effects.     

Revised estimates and projections of down syndrome births in the United States,and the effects of prenatal diagnosis utilization, 1970–2002

The objectives of this study were to: (1) calculate revised estimates and projections of United States annual Down syndrome (DS) births for 1970–2002, and (2) estimate the effects of amniocentesis on these baseline DS birth projections. Three models of amniocentesis utilization among 30–34 and ≧ 35-year-old women were considered. The recently revised Census Bureau birth projections, and new single year maternal age DS risk rates estimated from a 1970–1983 Ohio data set, were used. Data from all three Census Bureau projection series were analysed; series II was considered in depth since it is consistent with recent fertility levels. Assuming no use of amniocentesis, total estimated DS births dropped from about 4770 in 1970 to 4120 in 1980 (a 14 per cent decline), but are projected to a plateau of about 5100 by the year 1990 (a 24 per cent increase). DS births to women ≧ 35 would increase dramatically from about 1050 in 1980 to 1900 in 2000 (an 81 per cent increase). Assuming 1983 Ohio prenatal diagnosis ratios for women aged 30–34 (1.7 per cent) and ≧ 35 (23.4 per cent) are used nationally, an annual reduction of about 7 per cent of DS births in 1986 and 9 per cent in 2002 would result. Fifty and 70 per cent utilization among women 30–34 and 235, respectively, would reduce DS births by about 33 per cent in 1986 and 38 per cent in 2002. Therefore, if the projected increase in DS births is to be averted, utilization of prenatal diagnosis by ≧ 30-year-old women must increase substantially.     

Effects of field application of phosphate fertilizers on the availability and uptake of lead, zinc and cadmium by cabbage (Brassica chinensis L.) in a mining tailing contaminated soil

A field trial was conducted to evaluate the reduction of bioavailability of heavy metals including lead (Pb), zinc (Zn) and cadmium (Cd) in a soil contaminated by mining tailings in Shaoxing, Zhejiang, China. Three commercial phosphate (P) fertilizers including phosphate rock (PR), calcium magnesium phosphate (CMP), and single superphosphate (SSP) were applied to the plot at three P application rates, 50, 300, and 500 g/m2 with 9 treatments and control (CK). Plants, water soluble and exchangeable (WE) extra...     

彩虹方头鱼(Paracheirodon innesi)鱼鳃微环境特性及铜的生物有效性

建立了测定小个体鱼种鳃部微环境特殊条件的高密度暴露方法，利用这种方法测定了彩虹方头鱼（Paracheirodon innesi）鱼鳃微环境的、 pH、碱度、粘液含量等参数， 并根据测定结果计算了鱼鳃微环境中铜的形态分布。结果表明：高密度暴露可在15s左右建立动态平衡，鱼鳃与外部水体平衡pH7.2。鱼鳃微环境中，碱度在碱性条件下迅速增加。计算并讨论了鱼鳃微环境与外部水相中铜的形态分布和有效态含量差异。     

聚丙烯酸钠(SP)保水剂对不同基质氮、磷、钾、钠淋溶的影响

保水剂正逐步运用于干旱半干旱地区的水土保持和节水农业中,而聚丙烯酸钠(SP)是其中一种重要的保水剂.为了弄清保水剂对元素淋溶的影响,进行了水解污泥、湖泊底泥、山地黄壤3种基质,4种SP添加比例(0、1.0%、2.5%、4.0%)的淋溶试验,并分析测定了淋溶液中的氮、磷、钾、钠.结果表明,添加SP使水解污泥、湖泊底泥和山地黄壤的氮总淋溶量分别增加了67.8%、37.0%和95.7%,磷总淋溶量分别增加了151%、436%和219%.3种基质氮淋溶量的分配相同,而磷淋溶量的分配不同,说明不同基质中淋溶氮的类型相同,淋溶磷的类型不同.添加SP使水解污泥钾的总淋溶量增加了大约19%,而对湖泊底泥钾的总淋溶量无显著影响,却使山地黄壤钾的淋溶量降低了约67%,SP对钾淋溶的影响效果受基质类型和SP本身所含钠的影响.不同基质钠淋溶量都随SP添加比例的增加而显著增加,但它们淋溶量的分配模式各不相同,说明不同基质钠的来源不同.水解污泥淋溶的钠主要来自基质本身钠的活化,湖泊底泥淋溶的钠主要来自基质的活化和SP中的钠,而山地黄壤淋溶的钠主要来自SP中的钠.总之,SP保水剂处理下的元素淋溶量及其分配受SP比例、基质类型和元素类型影响,使用SP保水剂既能活化基质的氮、磷等养分,有利于植物生长,也具有增加钠离子从而导致土壤碱化的风险.     

Comparison of surface water chemistry and weathering effects of two lake basins in the Changtang Nature Reserve, China

The geochemistry of natural waters in the Changtang Nature Reserve,northern Tibet,can help us understand the geology of catchments,and provide additional insight in surface processes that influence water chemistry such as rock weathering on the Qinghai–Tibet Plateau.However,severe natural conditions are responsible for a lack of scientific data for this area.This study represents the first investigation of the chemical composition of surface waters and weathering effects in two lake basins in the reserve(Lake Dogaicoring Qiangco and Lake Longwei Co).The results indicate that total dissolved solids(TDS)in the two lakes are significantly higher than in other gauged lakes on the Qinghai–Tibet Plateau,reaching 20–40 g/L,and that TDS of the tectonic lake(Lake Dogaicoring Qiangco)is significantly higher than that of the barrier lake(Lake Longwei Co).Na+and Cl-are the dominant ions in the lake waters as well as in the glacier-fed lake inflows,with chemical compositions mainly affected by halite weathering.In contrast,ion contents of inflowing rivers fed by nearby runoff are lower and concentrations of dominant ions are not significant.Evaporite,silicate,and carbonate weathering has relatively equal effects on these rivers.Due to their limited scope,small streams near the lakes are less affected by carbonate than by silicate weathering.     

铜陵矿区河流沉积物重金属的迁移及环境效应

测定铜陵矿区的新桥至顺安河沉积物中5种重金属的全量和形态,并结合环境条件分析它们的迁移变化特征,以阐明不同重金属对河流沉积物环境影响的程度.结果表明,该区域沉积物重金属除Cr外,Cu、Zn、Pb、Cd的均值皆远超长江下游沉积物背景值,其中以Cu和Cd最显著.重金属横向迁移结果显示,矿山重金属会随着沉积物的距离增加而显著降低,新桥河沉积物的迁移变化显著高于顺安河沉积物.重金属Cu、Zn、Pb、Cr皆以残渣态为优势,Cd则以酸提取态为主;迁移过程中Cu、Zn、Cr残渣态逐步增加,毒性减弱;Pb、Cd的活性态比例增大,仍有较高的释放风险.重金属的纵向迁移结果表明,离矿山的位置远近对沉积柱金属的总量和形态起决定作用;新桥河沉积物金属总量高、活性组分多且垂向变化幅度相对较小,说明尾矿堆积速度较快且释放风险较高;顺安河金属总量较低但垂向变化幅度较大,且多种元素的变化趋势不同,说明矿区下游河流沉积物既受尾矿的影响,也受河流流域物质本身的影响.