Hot-blooded singers: endothermy facilitates crepuscular signaling in African platypleurine cicadas (Hemiptera: Cicadidae:<Emphasis Type="Italic"> Platypleura</Emphasis> spp.)

The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature ( T _b) show that these animals regulate T _b through endogenous heat production. Maximum T _b measured was 22.1°C above ambient temperature during calling activity at dusk. The mean T _b during dusk activity did not differ from the mean T _b during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate T _b. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.     

Ontogenetic variation in cold tolerance plasticity in Drosophila: is the Bogert effect bogus?

Ontogenetic variation in plasticity is important to understanding mechanisms and patterns of thermal tolerance variation. The Bogert effect postulates that, to compensate for their inability to behaviourally thermoregulate, less-mobile life stages of ectotherms are expected to show greater plasticity of thermal tolerance than more-mobile life stages. We test this general prediction by comparing plasticity of thermal tolerance (rapid cold-hardening, RCH) between mobile adults and less-mobile larvae of 16 Drosophila species. We find an RCH response in adults of 13 species but only in larvae of four species. Thus, the Bogert effect is not as widespread as expected.     

Indoor climate and thermal comfort in high-rise public housing in an equatorial climate: A field-study in Singapore

Urban residential development in Singapore has been focussed on clusters of high-rise public housing known locally as ‘new towns’. Indoor climatic conditions were assessed in a sample of 214 flats in the new towns. Also a sample of 583 occupants were interviewed about their experiences of thermal comfort. Separate body-environment heat-balances were estimated for each respondent and these data were input to the PMV (ISO 7730) mathematical model of thermal comfort. The operative temperature actually preferred by the respondents was about 1°C cooler than the mean value of 29.6°C recorded in their flats. However, their empirically derived temperature preference was about 2°C warmer than the value predicted by the PMV model and ISO standard. Processes of physiological acclimatization and perceptual habituation are put forward as possible explanations for the discrepancy between temperate climate comfort theory and actual human response in the tropics. The implications for energy conservation in tropical cities are also discussed.     

Increased lipid accumulation but not reduced metabolism explains improved starvation tolerance in cold-acclimated arthropod predators

Predatory arthropods are used for biological control in greenhouses, but there is increasing interest to extend their use to the outdoor environment where temperatures are typically lower. Acclimation at low temperature increases the ability of ectotherms to cope with subsequent more extreme cold, but may involve costs or benefits to other performance traits. A recent study in mesostigmatid mites (Gaeolaelaps aculeifer) showed that starvation tolerance was improved following a period of cold exposure. However, the physiological mechanisms that underlie improved starvation tolerance following cold exposure were not investigated. To examine whether cold acclimation would also improve starvation tolerance in an insect, we repeated the starvation study in another arthropod predator, the pirate bug Orius majusculus, as well as in G. aculeifer. Before tests, the two species were acclimated at 10, 15, or 20 °C for 7 (G. aculeifer) or 16 (O. majusculus) days. We then analyzed the effects of thermal exposure on body composition, consumption, and basal metabolic rate in both species. Our results confirmed that exposure to low temperature improves starvation tolerance in these arthropod predators. Body composition analyses revealed that both species had accumulated larger lipid stores during exposure to colder temperature, which at least in part can explain the larger starvation tolerance following cold exposure. In contrast, consumption and basal metabolic rate were not changed by thermal acclimation. Our study indicates that predatory arthropods exposed to cold increase their physiological robustness and ability to endure environmental challenges, including low temperature and low prey availability.     

Biochemical and ecological similarities in marsh plants and diving animals

Higher plants which can survive flooding have certain ecological and biochemical similarities with diving reptiles, birds, and mammals. The ecological similarities arise from the fact that these wet-land plants and diving animals are all terrestrial organisms which have re-entered the aquatic habitat as a retreat or ecological refuge free from interference by dry-land species. To survive in the wet-land or aquatic habitat species of terrestrial origin have to restrict their metabolic rate in the absence of oxygen and exploit a wide range of metabolic products to aid proton disposal and avoid the dangers of cell toxicity due to the accumulation of an excessive oxygen debt. In some plants metabolic adaptation to anoxia (low oxygen supply) resembles that found in animal parasites. It is a striking example of metabolic co-evolution that the retreat of so many terrestrial species of both plants and animals back to the low-oxygen habitat has been made possible by the exploitation of similar biochemical control mechanisms and pathways.     

消化污泥序批式驯化中产气性能和微生物多样性变化

利用序批式运行方法探索低活性厌氧接种污泥对新底物的适应过程。研究发现,接种污泥经过1个批次驯化后,后续批次的甲烷产量维持稳定,说明首批次培养实现了有效的代谢调整。分析各发酵批次的pH值和产甲烷动力学参数发现,随着驯化批次的增加,接种污泥产甲烷的延迟期缩短、产甲烷速率升高,且各批次初期酸化程度降低,说明了多批次驯化促进污泥对底物的适应能力。高通量测序技术分析驯化前后微生物群落结构可知,3个批次驯化后污泥菌群的丰富度和多样性均降低。驯化筛选出以Paludibacter属（相对丰度为52.3%）和Methanosaeta属（相对丰度为72.31%）为优势菌属的群落结构。     

Was basking important in the evolution of mammalian endothermy?

The first mammals were small, nocturnal, and presumably had low metabolic rates and were therefore probably unable to maintain a constant high body temperature throughout cool nights. How these animals, without sufficient heat production for endogenous rewarming, were able to become warm and active again before the next activity period remains unresolved. However, we discovered that, similar to reptiles, the carnivorous marsupial mammal Pseudantechinus macdonnellensis (body mass 30.8LJ.0 g) uses the morning sun to rewarm from low (26.3dž.5°C) body temperatures during torpor. Our findings provide the first evidence of basking during rewarming from torpor in mammals and may provide an alternative explanation as to how ancestral mammals could have become nocturnal to avoid diurnal predators despite their small size and a low endogenous heat production.     

海洋生物及生态系统对海洋酸化的响应

在过去 10 a中,海洋酸化已经成为全球海洋的一个新挑战。海洋酸化不仅会影响海洋中的碳化学、营养盐、微量元素等的地球化学特性,而且能影响海洋中微生物、浮游动植物、各种大型动物乃至整个海洋生态系统;不同区域的生物体系对酸化产生不同的响应,同一生物不同生命阶段的酸化响应可能截然不同;酸化给海洋带来的影响是及其复杂多变的,而且这些影响之间还存在复杂的相互作用;生态系统对海洋酸化的自然响应是很多生物和非生物因素独立和共同作用的结果;对很多单一物种或单一因素酸化响应的简单概括或总结,远不能描述海洋酸化对整个生态系统的影响规律。本文综述了海洋中微生物、浮游动植物、各种大型动物等海洋生物对酸化响应的研究进展,指出了目前海洋酸化研究中存在的一些不足,并提出了一些新的思路和方法。     

The last polar dinosaurs: high diversity of latest Cretaceous arctic dinosaurs in Russia

A latest Cretaceous (68 to 65 million years ago) vertebrate microfossil assemblage discovered at Kakanaut in northeastern Russia reveals that dinosaurs were still highly diversified in Arctic regions just before the Cretaceous–Tertiary mass extinction event. Dinosaur eggshell fragments, belonging to hadrosaurids and non-avian theropods, indicate that at least several latest Cretaceous dinosaur taxa could reproduce in polar region and were probably year-round residents of high latitudes. Palaeobotanical data suggest that these polar dinosaurs lived in a temperate climate (mean annual temperature about 10°C), but the climate was apparently too cold for amphibians and ectothermic reptiles. The high diversity of Late Maastrichtian dinosaurs in high latitudes, where ectotherms are absent, strongly questions hypotheses according to which dinosaur extinction was a result of temperature decline, caused or not by the Chicxulub impact.     

Hibernation in Malagasy mouse lemurs as a strategy to counter environmental challenge

The spiny forest of southwestern Madagascar is the driest and most unpredictable region of the island. It is characterized by a pronounced seasonality with high fluctuations in ambient temperature, low availability of food, and a lack of water during the cool dry season and, additionally, by changes in environmental conditions between years. One of the few mammalian species that manages to inhabit this challenging habitat is the reddish-gray mouse lemur (Microcebus griseorufus). The aim of our study was to determine whether this small primate uses continuous hibernation as an energy saving strategy, and if so, to characterize its physiological properties. We measured skin temperature of 16 free-ranging individuals continuously over 3 months during the cool dry season using collar temperature data loggers. Prolonged hibernation was found in three mouse lemurs and was not sex dependent (one male, two females). Skin temperature of hibernating individuals tracked ambient temperature passively with a minimum skin temperature of 6.5°C and fluctuated strongly each day (up to 20°C), depending on the insulation capacity of the hibernacula. Individuals remained in continuous hibernation even at an ambient temperature of 37°C. The animals hibernated continuously during the dry season, and hibernation bouts were only interrupted by short spontaneous arousals. The study emphasizes that hibernation is an important measure to counter environmental challenge for more tropical species than previously thought, including primates. It furthermore provides evidence that tropical hibernation is functionally similar among tropical species.     

Mushroom harvesting ants in the tropical rain forest

Ants belong to the most important groups of arthropods, inhabiting and commonly dominating most terrestrial habitats, especially tropical rainforests. Their highly collective behavior enables exploitation of various resources and is viewed as a key factor for their evolutionary success. Accordingly, a great variety of life strategies evolved in this group of arthropods, including seed harvesters, gardeners, and planters, fungus growers, nomadic hunters, life stock keepers, and slave makers. This study reports the discovery of a new lifestyle in ants. In a Southeast Asian rainforest habitat, Euprenolepis procera is specialized in harvesting a broad spectrum of naturally growing mushrooms, a nutritionally challenging and spatiotemporally unpredictable food source. While unfavorable to the vast majority of animals, E. procera has developed exceptional adaptations such as a shift to a fully nomadic lifestyle and special food processing capabilities, which allow it to rely entirely on mushrooms. As a consequence, E. procera is the most efficient and predominant consumer of epigeic mushrooms in the studied habitat and this has broad implications for the tropical rainforest ecosystem.     

Multiple Factors in the Evolution of Animal Coloration

Many of the subjects about which biologists disagree concern the interpretation of function. Morphological, physiological and behavioral characters can simultaneously serve several various functions, all of which are subject to natural selection. These may operate synergistically, but when two produce opposing effects, the one possessing the greater survival value at the time is selected. Often a compromise between several different evolutionary functions results. When the functions under consideration are viewed from a wider angle, a synthesis between differing opinions can sometimes be achieved and a greater understanding of the phenomenon obtained. It should be remembered that, even if an adaptation is invoked for only a brief time during the life of its possessor, it might well be selected merely because of its transient value then. This contribution is not a review, nor is it concerned with the biochemistry and physiology of pigmentation. Rather, it is a discussion of some of the diverse functions that have been ascribed to animal colours. A few typical examples are considered, chosen mainly from among tropical animals including human beings.     

A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., from the Permian of China

Captorhinids, a clade of Paleozoic reptiles, are represented by a rich fossil record that extends from the Late Carboniferous into the Late Permian. Representatives of this clade dispersed from the equatorial regions of Laurasia into the temperate regions of Pangea during the Middle and Late Permian. This rich fossil record shows that there was an evolutionary trend from faunivorous to omnivorous and herbivorous feeding habits within this clade. The discovery of well-preserved captorhinid materials in the Middle Permian of China allows us to determine that the new taxon, Gansurhinus qingtoushanensis, gen. et sp. nov, is a member of Moradisaurinae, a clade of captorhinids with multiple tooth rows arranged in parallel. The presence of this moradisaurine in the Middle Permian of south central Asia leads us to suggest that paleogeographic changes during the Permian, with part of what is today China becoming a large peninsula of Pangea, allowed these early reptiles as well as other terrestrial vertebrates to extend their geographic ranges to this region of the Late Paleozoic supercontinent.     

Vertebrate diet decreases winter torpor use in a desert marsupial

One of the energetic benefits of daily torpor over prolonged hibernation is that it enables animals to regularly forage and, therefore, replenish food reserves between bouts of torpor. However, little is known about the diet of predators undergoing torpor or whether differences in prey composition among individuals influence torpor characteristics. Here, we test the hypothesis that prey composition affects winter torpor use and patterns of a population of carnivorous marsupial, the brush-tailed mulgara (Dasycercus blythi), in the Great Sandy Desert, Australia. Mulgaras in the study population captured a wide range of prey including vertebrates (mammals, reptiles, birds), seven insect orders, spiders and centipedes. The proportion of vertebrates in the diet was negatively correlated with both frequency of torpor use and maximum bout duration. This variation in torpor use with diet can be explained by the higher energetic content of vertebrates as well as their larger size. Even assuming uniform intake of prey biomass among individuals, those that subsisted on an invertebrate-dominated diet during winter apparently suffered energetic shortages as a result of the scarcity of invertebrate taxa with high energy content (such as insect larvae). Our study is the first to demonstrate a link between diet composition and daily torpor use in a free-ranging mammal.     

Was endothermy in amniotes induced by an early stop in growth during ontogeny?

Endothermy and its evolution are still an unresolved issue. Here, we present a model which transforms an ectothermic amniote (ancestor) into a derived amniote (descendant) showing many characteristics seen in extant endothermic birds and mammals. Consistent with the fossil record within the ancestral lineages of birds and mammals, the model assumes that mutations in genes which get active during ontogeny and affect body growth resulted in a reduced asymptotic body size and an early growth stop of the descendant. We show that such a postulated early growth stop in the descendant simultaneously increases the growth rate and metabolic rate, and also changes six life history traits (offspring mass, annual clutch/litter mass, number of offspring per year, age and mass at which sexual maturity is reached, age at which the individual is fully grown) of the descendant compared to a similar-sized ancestor. All these changes coincide with known differences between recent ectothermic and endothermic amniotes. We also elaborate many other differences and similarities in biological characteristics supporting the early growth stop. An early stop in growth during ontogeny thus could have played a key role in the evolution of endothermy within the reptilia and therapsids. It generated variability in characteristics of ancestral ectotherms, which was subject to natural selection in the past and resulted in many adaptations linked to endothermy in today’s birds and mammals.     

垃圾渗滤液的生物降解特性与动态模型实验研究

应用微生物耗氧速率测定法对不同来源不同季节垃圾渗滤液的生物降解特性进行了比较评估 ,并采用经过长期驯化的厌氧 好氧废水生物处理模型系统对被评估为难生物降解的一种渗滤液进行了动态模拟运行试验。研究结果表明 ,不同来源的污泥菌种及驯化前后均表现出不同的生化代谢活性。驯化污泥对 3种被测渗滤液的耗氧速率常数相差甚大 ,3种待测废水分别被评估为易生物降解、难生物降解及不能被受试微生物降解等类别。当厌氧 好氧模型生物反应器系统进水CODCr、NH+4 N浓度分别为 3 0 18 9mg L、45 2 4mg L时出水质量可达到GB16889 1997排放标准。CODCr及NH+4 N总去除率分别为 78 9%和 75 8%。     

The relationship between the methane seasonal cycle and regional sources and sinks at Tae-ahn Peninsula,Korea

Methane measurements from weekly air samples collected at Tae-ahn Peninsula, Korea (TAP) present new constraints on the regional methane source strength of eastern Asia. Analysis of atmospheric trajectories shows that the lowest methane values observed at Tae-ahn are associated with southeasterly flow off the tropical Pacific Ocean and are similar to those observed at Cape Kumukahi, Hawaii. During June to August, northwesterly flow from the peat-rich wetlands located in the maritime provinces of the Far East former Soviet Union elevates methane at TAP by ∼80 ppb above the annual mean. Analysis of the Tae-ahn observations using a 3-D atmospheric methane model suggests that methane emission rates from the Far East Soviet wetlands may be ∼2 times those of Alaskan wetlands. Also, the relative maximum in May June at Tae-ahn constraints global CH₄ emissions from rice cultivation to ∼100 Tg yr⁻¹.     

全程自养脱氮系统中氨氧化菌关键种群的变迁

全程自养脱氮是在高铵氮低溶氧条件下完全由自养菌群作用而将水中氮素脱除的现象。特异性扩增16SrDNA上的氨氧化菌特异的CTO基因片段,建立克隆文库并进行系统发育学分析,考察全程自养脱氮系统菌群驯化及退化过程中氨氧化菌的结构组成和其中关键种群的变迁,结果表明:在驯化过程中Nitrosospira属细菌和Nitrosomonas oligotropha细菌逐渐被能够耐受高氨氮低溶氧的Nitrosomonas europaea细菌所代替,后者可能是全程自养脱氮系统氨氧化步骤的主要参与者,而氨氧化菌的菌群演变可能并不是后来系统退化的原因。     

热带雨林环境霉菌试验菌种筛选研究

目的 研究西双版纳热带雨林环境空气中的优势菌种和装备上的敏感菌种,为热带雨林环境霉菌试验的菌种筛选提供参考。方法 采用撞击法采集西双版纳试验站空气中的菌种,同时挑取试验站内正在进行环境试验的装备上生长的霉菌,通过纯化、鉴定、分析得到西双版纳热带雨林环境优势菌种和装备上的敏感菌种。结果 获得热带雨林环境优势菌种12株,装备材料上的敏感菌种10株。结论 根据霉菌对纤维、塑料、皮革、橡胶和纺织品的影响,筛选出6株优势菌种结合10株敏感菌种作为装备霉菌试验添加菌种。