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1.
Evolutionary Ecology - Understanding how environmental conditions affect trait expression in animals is important for estimating the evolutionary potential of that trait. Two different mechanisms...  相似文献   
2.
KV Thomas 《Biofouling》2013,29(1):73-86

Antifouling paint booster biocides are a group of organic compounds added to antifouling paints to improve their efficacy. They have become prevalent since the requirement for alternative antifouling paints formulations for small boats (< 25 m). This need followed a ban on the use of triorganotin biocides in antifouling paints for small boats, in the late 1980's. Worldwide, around eighteen compounds are currently used as antifouling biocides, viz. benzmethylamide, chlorothalonil, copper pyrithione, dichlofluanid, diuron, fluorofolpet, Irgarol 1051, Sea‐Nine 211, Mancozeb, Polyphase, pyridine‐triphenyl‐borane, TCMS (2,3,5,6‐tetrachloro‐4‐methylsulfonyl) pyridine, TCMTB [2‐(thiocyanomethylthio)benzothia‐zole], Thiram, tolyfluanid, zinc pyrithione (ZPT), ziram and Zineb. Any booster biocide released into the environment is subjected to a complex set of processes. These processes include transport mechanisms, transformation, degradation, cross media partitioning, and bioaccumulation. This paper reviews the fate and behaviour data currently available in the public domain concerning antifouling paint booster biocides.  相似文献   
3.
Recent empirical and conceptual papers have highlighted the potential for metabolism to act as a proximate mechanism for behavior that could explain animal personality (consistency over time). Under this hypothesis, individuals with consistently high levels of behavioral activity should also have high resting metabolic rate (RMR) as it can reflect capacity to process food and generate energy. We tested for the predicted positive covariance between RMR and three behaviors that differ in energy demands in 30 male guppies, using multivariate mixed models; we repeatedly measured their activity (10 times each), courtship displays (nine times), voracity (10 times), and metabolism (four‐times). Resting metabolic rate (measured overnight in respirometry trials) did not consistently differ among males, whereas initial peak metabolism measured during those same trials (= 0.42), and all behaviors were repeatable (= 0.33–0.51). RMR declined over time suggesting habituation to the protocol, whereas peak metabolism did not. Initial peak metabolism was negatively correlated with courtship display intensity, and voracity was positively correlated with activity, but all other among‐individual correlations were not significant. We conclude that RMR does not provide a proximate explanation for consistent individual differences in behavior in male guppies, and therefore the potential for independent evolution of these physiological and behavioral traits seems possible. Finally, we identify peak metabolism as a potential measure of the stress response to confinement, which highlights the value of considering various aspects of metabolic rates recording during respirometry trials.  相似文献   
4.
In the Barwon River, Australia, a tidal barrage formed a major impediment to fish movement so in 2013 a vertical slot fishway was installed. The assessment of fishways on tidal barriers is rare in Australia so to ensure the fishway was achieving its ecological objective (i.e. successfully passing the target size range of fish of 20–400 mm total length), fish were trapped at the entrance and exit on 12 occasions and the species composition, abundance and length of fish at the two locations were compared. Additionally, a section of the river downstream of the fishway was sampled to ensure fishway trapping accurately reflected the species composition wanting to use the fishway to move upstream. Eighteen species and 69,246 individual fish were caught in the fishway traps. Catch rates between locations did not differ for Common Galaxias (Galaxias maculatus) or Australian Smelt (Retropinna semoni), although species‐specific catch rates were lower at the exit for Flat‐headed Gudgeon (Philypnodon grandiceps), Tupong (Pseudaphritis urvillii) and Yellow‐eye Mullet (Aldrichetta forsteri). Length distribution between locations only differed for Australian Smelt with small fish under‐represented at the exit location (<25 mm total length). Eight species of fish were collected downstream of the fishway that were not collected in it; however, all of these were estuarine dependent except the non‐native Common Carp (Cyprinus carpio). Our results indicate that vertical slot fishways are a suitable design for improving river connectivity at a low head, tidal barrages in south‐eastern Australia. The study reiterates the importance of reinstating connectivity for species with obligate marine/freshwater migratory life history traits, and the indirect benefits of increased productivity made available to upstream areas.  相似文献   
5.

Background

The function of proteins is a direct consequence of their three-dimensional structure. The structural classification of proteins describes the ways of folding patterns all proteins could adopt. Although, the protein folds were described in many ways the functional properties of individual folds were not studied.

Results

We have analyzed two β-barrel folds generally adopted by small proteins to be looking similar but have different topology. On the basis of the topology they could be divided into two different folds named SH3-fold and OB-fold. There was no sequence homology between any of the proteins considered. The sequence diversity and loop variability was found to be important for various binding functions.

Conclusions

The function of Oligonucleotide/oligosaccharide-binding (OB) fold proteins was restricted to either DNA/RNA binding or sugar binding whereas the Src homology 3 (SH3) domain like proteins bind to a variety of ligands through loop modulations. A question was raised whether the evolution of these two folds was through DNA shuffling.  相似文献   
6.
7.
We report the molecular epidemiology of highly pathogenic avian influenza (HPAI) virus involved in an outbreak causing death in free-ranging wild birds at Mysore, Karnataka state of India. The virus was typed as HPAI A(H5N8) by conventional and TaqMan probe based real-time PCR assays. Six isolates of HPAI virus were recovered in 9-day-old embryonated chicken eggs. Haemagglutinin gene-based phylogeny of virus isolates showed >?99.9% nucleotide sequence identity with HPAI A(H5N8) isolates from migratory birds and domestic poultry from China and Korea indicating either these wild birds have routed their migration through Korea and/or eastern China or these dead birds must have directly or indirectly contacted with wild birds migrating from Eastern China and/or Korean regions. The study emphasises the role of migratory wild birds in spread of HPAI across the globe.  相似文献   
8.
Understanding underlying physiological differences between the sexes in circulating androgens and how hormonal variation affects morphology–performance relationships may help clarify the evolution of sexual dimorphism in diverse taxa. Using a widely distributed Australian lizard (Eulamprus quoyii) with weak sexual dimorphism and no dichromatism, we tested whether circulating androgens differed between the sexes and whether they covaried with morphological and performance traits (bite force, sprint speed, endurance). Males had larger head dimensions, stronger bite force, faster sprint speed, and longer endurance compared to females. We found that the sexes did not differ in androgen concentrations and that androgens were weakly associated with both morphological and performance traits. Interestingly, high circulating androgens showed a nonlinear relationship with bite force in males and not females, with this relationship possibly being related to alternative male reproductive tactics. Our results suggest that androgens are not strongly correlated with most performance and morphological traits, although they may play an important organizational role during the development of morphological traits, which could explain the differences in morphology and thus performance between the sexes. Differences in performance between the sexes suggest differential selection on these functional traits between males and females. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 834–849.  相似文献   
9.
Extensive research has examined the effects of social isolation in neonatal and adult animal populations, but few studies have examined the effect of social isolation in early adulthood. Animals reaching reproductive age often experience extensive social changes as they leave their natal site, and a social stressor like isolation may uniquely affect this age group. Furthermore, adolescence is a time when sex differences in behavior become more pronounced. As such, the effects of social stressors are likely to vary by sex. In this study, we used noninvasive methods to evaluate stress responses to social change in male and female subadult chickens (Gallus gallus). Half of the birds experienced regular sessions of social isolation over the course of 2 wk, while the other half were never isolated. Subsequently, all of the animals were exposed to a suite of three novel probes, including an open‐field test. We monitored the birds’ behavioral (head movements) and physiological (fecal glucocorticoid metabolites, FGM) response to the tests. Our results indicate that, for subadult chickens, the effect of social isolation is sex dependent: Male FGM and behavioral responses did not change with subsequent experiences, in contrast to females. Females also exhibited more social reinstatement behavior compared to males. Our results are consistent with the expectations of differences between the sexes based on changes in the social environment due to sex‐biased dispersal patterns. For both sexes, the FGM and behavioral responses varied independently, which highlights the necessity for multiple measures of stress in animal populations.  相似文献   
10.
The trade-off between lifespan and reproduction is commonly explained by differential allocation of limited resources. Recent research has shown that the ratio of protein to carbohydrate (P : C) of a fly''s diet mediates the lifespan–reproduction trade-off, with higher P : C diets increasing egg production but decreasing lifespan. To test whether this P : C effect is because of changing allocation strategies (Y-model hypothesis) or detrimental effects of protein ingestion on lifespan (lethal protein hypothesis), we measured lifespan and egg production in Queensland fruit flies varying in reproductive status (mated, virgin and sterilized females, virgin males) that were fed one of 18 diets varying in protein and carbohydrate amounts. The Y-model predicts that for sterilized females and for males, which require little protein for reproduction, there will be no effect of P : C ratio on lifespan; the lethal protein hypothesis predicts that the effect of P : C ratio should be similar in all groups. In support of the lethal protein hypothesis, and counter to the Y-model, the P : C ratio of the ingested diets had similar effects for all groups. We conclude that the trade-off between lifespan and reproduction is mediated by the detrimental side-effects of protein ingestion on lifespan.  相似文献   
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