Considering the deficiency of the means for confirming the attribution of fault redundancy in the re-search of Automatic Testing System(ATS) , a fault-injection system has been proposed to study fault redundancyof aut...Considering the deficiency of the means for confirming the attribution of fault redundancy in the re-search of Automatic Testing System(ATS) , a fault-injection system has been proposed to study fault redundancyof automatic testing system through compurison. By means of a fault-imbeded environmental simulation, thefaults injected at the input level of the software are under test. These faults may induce inherent failure mode,thus bringing about unexpected output, and the anticipated goal of the test is attained. The fault injection con-sists of voltage signal generator, current signal generator and rear drive circuit which are specially developed,and the ATS can work regularly by means of software simulation. The experimental results indicate that the faultinjection system can find the deficiency of the automatic testing software, and identify the preference of fault re-dundancy. On the other hand, some soft deficiency never exposed before can be identified by analyzing the tes-ting results.展开更多
This study deals with a new evaluation method of nuclear electromagnetic pulse (NEMP) vulnerability on cots electronic equipments. The method consists in comparing electromagnetic compatibility (EMC) test severiti...This study deals with a new evaluation method of nuclear electromagnetic pulse (NEMP) vulnerability on cots electronic equipments. The method consists in comparing electromagnetic compatibility (EMC) test severities to NEMP conducted stresses. The comparison uses five characteristic criteria of the induced stresses, calculated with an analytic method. The process is based on a software named "SUSIE" (in French: SUSceptibilite a I'IEMN "Impulsion ElectroMagnttique d'origine Nucl6aire Haute Altitude"). Today, only conducted stresses are analyzed. An evolution is planned in 2013 to determine the equivalent vulnerability of radiated stresses and to validate the software.展开更多
This paper examined variation in Onko dialect using the family tree model and the corresponding comparative method as the theoretical tool. A wordlist of basic items and a designed frame technique were used to gather ...This paper examined variation in Onko dialect using the family tree model and the corresponding comparative method as the theoretical tool. A wordlist of basic items and a designed frame technique were used to gather data for this study. The data were presented in tables and the analyses were done through descriptive statistics. The data were analyzed to determine variation at the phonological, syntactic and lexical levels. The study revealed differences between Standard Yoruba and Onko dialect as well as the variation therein. Two basic factors discovered to be responsible for variations in Onko are geography(distribution of Onko communities) and language contact. The paper established that Onko exhibits variations, which are however not significant enough to disrupt mutual intelligibility among the speakers, and thus all the varieties remain a single dialect.展开更多
For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that...For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that the latter should be adopted so as to increase the operation reliability of large generators and power systems.展开更多
To assess the operational safety risk of long-term evolution for the metro(LTE-M)communication system more accurately,the guide maintenance strategy,the improved evidence theory and the multi-attribute ideal reality c...To assess the operational safety risk of long-term evolution for the metro(LTE-M)communication system more accurately,the guide maintenance strategy,the improved evidence theory and the multi-attribute ideal reality comparative analysis(MAIRCA)approaches are proposed.According to the features of LTE-M system,the risk evaluation system is established.The enhanced structural entropy weight method is used to obtain the weight.Furthermore,it is combined with nine-element fuzzy mathematics to transform the degree of membership,modifying the conflict and fusion rules to solve the confidence degree clashed problem of evidence theory.Then,the system risk grade assessment result is obtained.For the purpose of forming the ranking of indicator importance,the MAIRCA is introduced and the ranking is three-dimensional.The operational state of the metro line is used as the data source in various ways the obtained risk grade increased by 7.12%.It is verified that MAIRCA can be applied to the field of urban rail transit because it has based on the test and calculation.The results show that the method is effective;compared with others,the confidence degree of excellent stability and the ranking result of risk factors is reasonable.The influencing indicator with the highest importance is the'equipment failure rate".展开更多
Comparative studies of trait evolution require accounting for the shared evolutionary history. This is done by includ- ing phylogenetic hypotheses into statistical analyses of species' traits, for which birds often s...Comparative studies of trait evolution require accounting for the shared evolutionary history. This is done by includ- ing phylogenetic hypotheses into statistical analyses of species' traits, for which birds often serve as excellent models. The online publication of the most complete molecular phylogeny of extant bird species (www.birdtree.org, BirdTree hereafter) now allows evolutionary biologists to rapidly obtain sets of equally plausible phylogenetic trees for any set of species to be incorporated as a phylogenetic hypothesis in comparative analyses. We discuss methods to use BirdTree tree sets for comparative studies, either by building a consensus tree that can be incorporated into standard comparative analyses, or by using tree sets to account for the ef- fect of phylogenetie uncertainty. Methods accounting for phylogenetic uncertainty should be preferred whenever possible because they should provide more reliable parameter estimates and realistic confidence intervals around them. Based on a real compara- tive dataset, we ran simulations to investigate the effect of variation in the size of the random tree sets downloaded from BirdTree on the variability of parameter estimates from a bivariate relationship between mass-specific productivity and body mass. Irre- spective of the method of analysis, using at least 1,000 trees allows obtaining parameter estimates with very small (〈 0.15%) co- efficients of variation. We argue that BirdTree, due to the ease of use and the major advantages over previous 'traditional' meth- ods to obtain phylogenetic hypotheses of bird species (e.g. supertrees or manual coding of published phylogenies), will become the standard reference in avian comparative studies for years to come.展开更多
Both observational and indirect evidence are widely used to determine the diets of wild animals.Direct observations are often assumed to provide the most comprehensive reflection of diet,but many wild animals are logi...Both observational and indirect evidence are widely used to determine the diets of wild animals.Direct observations are often assumed to provide the most comprehensive reflection of diet,but many wild animals are logistically challenging to observe.Despite the regular use of observa-tional and indirect methods for inferring diet in wild animals,they have rarely been compared in detail for the same study population.Over 12 months this study assessed the congruence of methods in estimating the diet of a montane community of eastern chimpanzees Pan troglodytes schweinfurthii in Nyungwe National Park,Rwanda using observational scan samples and macro-scopic fecal inspection.The assessment of the number of food species consumed each month was comparable between methods,but the estimation of the composition of items in the diet differed significantly.Most notably,the fecal samples significantly underestimated the consumption of flowers,and certain fruit species,which based on direct behavioral observations were seasonally consumed at very high rates.Conversely,direct observations underestimated the consumption of leaves and pith in comparison to results present in the fecal samples.These results suggest that combining methods where possible is most useful for accurate monitoring of dietary trends,particularly for species that experience significant seasonal shifts in their diet.展开更多
An animal's pelage,feather,or skin color can serve a variety of functions,so it is important to have multiple standardized methods for measuring color.One of the most common and reliable methods for measuring anim...An animal's pelage,feather,or skin color can serve a variety of functions,so it is important to have multiple standardized methods for measuring color.One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals.New tech no logy in the form of a commercially available handheld digital color sensor could provide an alter native to photography-based animal color measurements.To determine whether a digital color sensor could be used to measure animal coloration,we tested the ability of a digital color sensor to measure coloration of mammalian,avian,and lepidopteran museums specimens.We compared results from the sensor to measurements taken using traditional photography methods.Our study yielded significant differences between photography-based and digital color sensor measurements of brightness(light to dark)and colors along the green to red spectrum.There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum.The average difference in recorded color(AE)by the 2 methods was above the threshold at which humans can perceive a difference.There were sign讦icant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool.However,the sensor's small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research.We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.展开更多
As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evol...As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evolution in multiple components of a complex courtship signal in darters, specifically addressing the question of how nuptial coloration evolves across different areas of the body. Using spectral reflectance, we defined 4 broad color classes present on the body and fins of 17 species of freshwater fishes (genus Etheostoma) and quantified differences in hue within each color class. Ancestral state reconstruction suggests that most color traits were expressed in the most recent common ancestor of sampled species and that differences among species are mostly due to losses in coloration. The evolutionary lability of coloration varied across body regions; we found sig- nificant phylogenetic signal for orange color on the body but not for most colors on fins. Finally, patterns of color evolution and hue Of the colors were correlated among the two dorsal fins and between the anterior dorsal and anal fins, but not between any of the fins and the body. The observed patterns support the hypothesis that different components of complex signals may be subject to distinct evolutionary pressures, and suggests that the combination of behavioral displays and morphology in communication may have a strong influence on patterns of signal evolution .展开更多
The distance from an approaching threat at which animals initiate flight - flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessin...The distance from an approaching threat at which animals initiate flight - flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assess- ment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats [Current Zoology 61 (4): 773-780, 2015].展开更多
Although the East Asian monsoon is believed to be an important driver for the origin and evolution of the biotas in this region,the association has rarely been rigorously tested.Here,using phylogenetic comparative met...Although the East Asian monsoon is believed to be an important driver for the origin and evolution of the biotas in this region,the association has rarely been rigorously tested.Here,using phylogenetic comparative methods and analyses of key innovations of adaptive traits,we investigated evolutionary patterns of the East Asian cyprinid opsariichthyin-xenocyprinin-cultrin clade;the dominant species in lakes and rivers,which are the typical productions of monsoon climate.Our molecular phylogenetic analyses revealed the relationships as(Opsariichthystribe t(((Oxygaster-tribe t Aphyocypris-tribe)t Metzia-tribe)t(Paralaubuca-tribe t(Squaliobarbus-tribe t(Hypophthalmichthys-tribe t(xenocyprinins t cultrins)))))).Based on Bayesian relaxed-clock methods,we found that origins of the Squaliobarbus-and Hypophthalmichthys-tribes bearing the key adaptation of riverine spawning with drifting eggs occurred 22.5 and 21.1 Mya,respectively.These times are consistent with the Early Miocene origin of major rivers(e.g.,Yangtze River)and the appearance of the East Asian monsoon climate.Diversification of the cultrins,characterized by spawning of adhesive eggs as well as swimming and feeding in lentic waters,were estimated to have evolved 16.6 to 0.2 Mya.This period covers three phases of enhancement of the East Asian monsoon from the Middle Miocene to the Pliocene(around 15–13,10–7,and 3.5 Mya).The habitats of these cultrins and their evolution also suggest the appearance and development of a lake-river environment during those periods.Therefore,our results suggest close relationships between the evolution of these fishes and geological events in East Asia.Further,they provide knowledge that may help facilitate future conservation strategies such as the maintenance of high river flows during dam construction and operation.展开更多
A feasible method of combining the concept of fluorescence half-life and the power dependent photo- bleaching rate for characterizing the practical photostability of fluorescent proteins (FPs) was introduced. Furthe...A feasible method of combining the concept of fluorescence half-life and the power dependent photo- bleaching rate for characterizing the practical photostability of fluorescent proteins (FPs) was introduced. Furthermore, by using a fluorescent photostability standard, a relative comparison of the photostabilty of FPs from different research groups was proposed, which would be of great benefit for developing novel FPs with optimized emission wavelength, better brightness, and improved photostability. We used rho- damine B as an example to verify this method and evaluate the practical photostability of a far-red FP, mKate-S158C. Experimental results indicated good potential of this method for further study.展开更多
Geomyoid rodents provide a great study system for the analysis of sexual dimorphism.They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism.In fact,there has been extensive wor...Geomyoid rodents provide a great study system for the analysis of sexual dimorphism.They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism.In fact,there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent clade.However,little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual dimorphism.We use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s rule.Our results suggest that sexual dimorphism is more common in geomyids than heteromyids,but it is not in fact universal.There is evidence for variation in sexual dimorphism across populations.Additionally,in many taxa,geographic variation appears to overwhelm existing sexual dimorphism.We find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa,but we do not find support for an association between size and shape dimorphism.There is no evidence for Rensch’s rule in geomyoids,whether at the superfamily or family level.Together,our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that,instead,it is the product of numerous evolutionary events.Future studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.展开更多
Selective pressures favor morphologies that are adapted to distinct ecologies,resulting in trait partition!ng among ecomorphotypes.However,the effects of these selective pressures vary across taxa,especially because m...Selective pressures favor morphologies that are adapted to distinct ecologies,resulting in trait partition!ng among ecomorphotypes.However,the effects of these selective pressures vary across taxa,especially because morphology is also influenced by factors such as phylogeny,body size,and functional trade-offs.In this study,we examine how these factors impact functional diversification in mammals.It has been proposed that trait partitioning among mammalian ecomorphotypes is less pronoun ced at small body sizes due to biomecha nical,energetic,and environ mental factors that favor a"generalist"body plan,whereas larger taxa exhibit more substantial functional adaptations.We title this the Diverge nee Hypothesis(DH)because it predicts greater morphological divergence among ecomorphotypes at larger body sizes.We test DH by using phylogenetic comparative methods to examine the postcranial skeletons of 129 species of taxonomically diverse,small-tomedium-sized(<15 kg)mammals,which we categorize as either"tree-dwellers"or"ground-dwellers."In some analyses,the morphologies of ground-dwellers and tree-dwellers suggest greater between-group differentiation at larger sizes,providing some evidence for DH.However,this trend is n either particularly strong nor supported by all an alyses.In stead,a more pronoun ced patter n emerges that is distinct from the predictions of DH:within-group phenotypic disparity increases with body size in both ground-dwellers and tree-dwellers,driven by morphological outliers among"medium'-sized mammals.Thus,evolutionary increases in body size are more closely linked to increases in within-locomotor-group disparity tha n to in creases in betwee n-group disparity.We discuss biomechanical and ecological factors that may drive these evolutionary patter ns,and we emphasize the significant evolutionary influences of ecology and body size on phenotypic diversity.展开更多
Key inn ovations may allow lin eages access to new resources and facilitate the invasi on of new adaptive zon es,potentially influencing diversificati on patter ns.Many studies have focused on the impact of key inno v...Key inn ovations may allow lin eages access to new resources and facilitate the invasi on of new adaptive zon es,potentially influencing diversificati on patter ns.Many studies have focused on the impact of key inno vations on speciation rates,but far less is known about how they influe nee phe notypic rates and patterns of ecomorphological diversification.We use the repeated evolution of pharyngognathy within acanthomorph fishes,a commonly cited key innovation,as a case study to explore the predicti ons of key inn ovation theory.Specifically,we in vestigate whether transiti ons to phary ngognathy led to shifts in the rate of phenotypic evolution,as well as shifts and/or expansion in the occupation of morphological and dietary space,using a dataset of 8 morphological traits measured across 3,853 species of Acanthomorpha.Analyzing the 6 evolutionarily independent pharyngognathous clades together,we found no evidence to support pharyngognathy as a key innovation;however,comparisons between individual pharyngognathous lineages and their sister clades did reveal some consistent patterns.In morphospace,most pharyngognathous clades cluster in areas that correspond to deeper-bodied morphologies relative to their sister clades,whereas occupying greater areas in dietary space that reflects a more diversified diet Additi on ally,both Cichlidae and Labridae exhibited higher univariate rates of phenotypic evolution compared with their closest relatives.However,few of these results were exceptional relative to our null models.Our results suggest that transitions to pharyngognathy may only be advantageous when combined with additional ecological or intrinsic factors,illustrating the importance of account!ng for lineage-specific effects when testing key innovation hypotheses.Moreover,the challenges we experienced formulating informative comparisons,despite the ideal evolutionary scenario of multiple independent evolutionary origins of pharyngognathous clades,illustrates the complexities involved in quantifying the impact of key innovations.Given the issues of lineage specific effects and rate heterogeneity at macroevolutionary scales we observed,we suggest a reassessment of the expected impacts of key innovations may be warranted.展开更多
This article investigates what might be characterised as "the forensic challenge" for criminal adjudication and clarifies its nature and scope. The "challenge" identified is complex, dynamic and multifaceted, enco...This article investigates what might be characterised as "the forensic challenge" for criminal adjudication and clarifies its nature and scope. The "challenge" identified is complex, dynamic and multifaceted, encompassing a variety of issues and debates concerning the ways in which forensic science evidence is validated, generated, presented, tested, evaluated and utilised in criminal proceedings. Common law evidentiary principles governing the admissibility of scientific evidence and expert witness testimony are reviewed and the underlying assumptions and potential weaknesses of adversarial trial procedure are critically considered. The discussion is pitched at the generic level of recurring intellectual puzzles, institutional design, regulatory frameworks, procedural structures and processes, macro-policy choices and methodological prescriptions, with the intention of making it relevant to an international audience. Aspects of the procedural law and adjudicative practice of England and Wales, and the regulatory context of UK forensic science, are offered as concrete illustrations with the potential for illuminating comparative extrapolation to other legal systems. In conclusion, the article draws out specific implications for Chinese scholarship, law reform and policymaking in relation to scientific and other expert evidence, and advances a bold suggestion for entertaining an unconventionally expansive conception of "forensic science" and, correspondingly, of the challenges it presents.展开更多
Gasoline evaporation is an important anthropogenic source of atmospheric volatile organic compounds(VOCs). Total OH reactivity for gasoline vapor was measured from 4 kinds of gasoline for the first time by comparati...Gasoline evaporation is an important anthropogenic source of atmospheric volatile organic compounds(VOCs). Total OH reactivity for gasoline vapor was measured from 4 kinds of gasoline for the first time by comparative reactivity method(CRM) using proton transfer reaction mass spectrometer(PTR-MS).Compositions of 56 PAMS(photochemical assessment monitoring station) nonmethane hydrocarbons(NMHCs) were measured for both liquid and headspace of gasoline. We found high abundance of alkenes and aromatics in gasoline. The calculated OH reactivity derived from quantified NMHCs speciation accounted for only 57 ? 4% of total reactivity obtained from CRM method. N-Alkenes, only 6 wt% in liquid gasoline, contributed to 70% of calculated reactivity. We assume that the undetected branched alkenes are the possible reason for the missing reactivity. We suggest that the priority of gasoline quality improvement is to reduce alkenes content in gasoline in term of reactivity-based control.展开更多
基金Sponsored by the Fund of "the Tenth 5-year" Preparatory Project of National Defence(Grant No. 417010402)
文摘Considering the deficiency of the means for confirming the attribution of fault redundancy in the re-search of Automatic Testing System(ATS) , a fault-injection system has been proposed to study fault redundancyof automatic testing system through compurison. By means of a fault-imbeded environmental simulation, thefaults injected at the input level of the software are under test. These faults may induce inherent failure mode,thus bringing about unexpected output, and the anticipated goal of the test is attained. The fault injection con-sists of voltage signal generator, current signal generator and rear drive circuit which are specially developed,and the ATS can work regularly by means of software simulation. The experimental results indicate that the faultinjection system can find the deficiency of the automatic testing software, and identify the preference of fault re-dundancy. On the other hand, some soft deficiency never exposed before can be identified by analyzing the tes-ting results.
文摘This study deals with a new evaluation method of nuclear electromagnetic pulse (NEMP) vulnerability on cots electronic equipments. The method consists in comparing electromagnetic compatibility (EMC) test severities to NEMP conducted stresses. The comparison uses five characteristic criteria of the induced stresses, calculated with an analytic method. The process is based on a software named "SUSIE" (in French: SUSceptibilite a I'IEMN "Impulsion ElectroMagnttique d'origine Nucl6aire Haute Altitude"). Today, only conducted stresses are analyzed. An evolution is planned in 2013 to determine the equivalent vulnerability of radiated stresses and to validate the software.
文摘This paper examined variation in Onko dialect using the family tree model and the corresponding comparative method as the theoretical tool. A wordlist of basic items and a designed frame technique were used to gather data for this study. The data were presented in tables and the analyses were done through descriptive statistics. The data were analyzed to determine variation at the phonological, syntactic and lexical levels. The study revealed differences between Standard Yoruba and Onko dialect as well as the variation therein. Two basic factors discovered to be responsible for variations in Onko are geography(distribution of Onko communities) and language contact. The paper established that Onko exhibits variations, which are however not significant enough to disrupt mutual intelligibility among the speakers, and thus all the varieties remain a single dialect.
文摘For large generators, the problem of high-resistance grounding method and the advantages of resonance, grounding method are discussed in detail, and an overall comparison is given in this paper. It is recommended that the latter should be adopted so as to increase the operation reliability of large generators and power systems.
基金supported by grants from the National Natural Science Foundation of China(Grant No.61661027)the Gansu Provincial Department of Education:Excellent Postgraduate‘Innovation Star’Project(Grant No.2022CXZX-619).
文摘To assess the operational safety risk of long-term evolution for the metro(LTE-M)communication system more accurately,the guide maintenance strategy,the improved evidence theory and the multi-attribute ideal reality comparative analysis(MAIRCA)approaches are proposed.According to the features of LTE-M system,the risk evaluation system is established.The enhanced structural entropy weight method is used to obtain the weight.Furthermore,it is combined with nine-element fuzzy mathematics to transform the degree of membership,modifying the conflict and fusion rules to solve the confidence degree clashed problem of evidence theory.Then,the system risk grade assessment result is obtained.For the purpose of forming the ranking of indicator importance,the MAIRCA is introduced and the ranking is three-dimensional.The operational state of the metro line is used as the data source in various ways the obtained risk grade increased by 7.12%.It is verified that MAIRCA can be applied to the field of urban rail transit because it has based on the test and calculation.The results show that the method is effective;compared with others,the confidence degree of excellent stability and the ranking result of risk factors is reasonable.The influencing indicator with the highest importance is the'equipment failure rate".
文摘Comparative studies of trait evolution require accounting for the shared evolutionary history. This is done by includ- ing phylogenetic hypotheses into statistical analyses of species' traits, for which birds often serve as excellent models. The online publication of the most complete molecular phylogeny of extant bird species (www.birdtree.org, BirdTree hereafter) now allows evolutionary biologists to rapidly obtain sets of equally plausible phylogenetic trees for any set of species to be incorporated as a phylogenetic hypothesis in comparative analyses. We discuss methods to use BirdTree tree sets for comparative studies, either by building a consensus tree that can be incorporated into standard comparative analyses, or by using tree sets to account for the ef- fect of phylogenetie uncertainty. Methods accounting for phylogenetic uncertainty should be preferred whenever possible because they should provide more reliable parameter estimates and realistic confidence intervals around them. Based on a real compara- tive dataset, we ran simulations to investigate the effect of variation in the size of the random tree sets downloaded from BirdTree on the variability of parameter estimates from a bivariate relationship between mass-specific productivity and body mass. Irre- spective of the method of analysis, using at least 1,000 trees allows obtaining parameter estimates with very small (〈 0.15%) co- efficients of variation. We argue that BirdTree, due to the ease of use and the major advantages over previous 'traditional' meth- ods to obtain phylogenetic hypotheses of bird species (e.g. supertrees or manual coding of published phylogenies), will become the standard reference in avian comparative studies for years to come.
基金the University of Western Australia,UWA Postgraduate Student Association and Baslcr Stiftung fiir Biologischc Forschung(Switzerland).
文摘Both observational and indirect evidence are widely used to determine the diets of wild animals.Direct observations are often assumed to provide the most comprehensive reflection of diet,but many wild animals are logistically challenging to observe.Despite the regular use of observa-tional and indirect methods for inferring diet in wild animals,they have rarely been compared in detail for the same study population.Over 12 months this study assessed the congruence of methods in estimating the diet of a montane community of eastern chimpanzees Pan troglodytes schweinfurthii in Nyungwe National Park,Rwanda using observational scan samples and macro-scopic fecal inspection.The assessment of the number of food species consumed each month was comparable between methods,but the estimation of the composition of items in the diet differed significantly.Most notably,the fecal samples significantly underestimated the consumption of flowers,and certain fruit species,which based on direct behavioral observations were seasonally consumed at very high rates.Conversely,direct observations underestimated the consumption of leaves and pith in comparison to results present in the fecal samples.These results suggest that combining methods where possible is most useful for accurate monitoring of dietary trends,particularly for species that experience significant seasonal shifts in their diet.
基金Funding for this study was provided by Florida's State Wildlife Grant through Florida's Wildlife Legacy Initiative.
文摘An animal's pelage,feather,or skin color can serve a variety of functions,so it is important to have multiple standardized methods for measuring color.One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals.New tech no logy in the form of a commercially available handheld digital color sensor could provide an alter native to photography-based animal color measurements.To determine whether a digital color sensor could be used to measure animal coloration,we tested the ability of a digital color sensor to measure coloration of mammalian,avian,and lepidopteran museums specimens.We compared results from the sensor to measurements taken using traditional photography methods.Our study yielded significant differences between photography-based and digital color sensor measurements of brightness(light to dark)and colors along the green to red spectrum.There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum.The average difference in recorded color(AE)by the 2 methods was above the threshold at which humans can perceive a difference.There were sign讦icant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool.However,the sensor's small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research.We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.
基金Acknowledgements We thank Michael Martin, Tory Williams, and Alex Nahm for assistance in collecting fishes and the Mendelson lab for assistance in fish maintenance. We thank Chioma Ihekweazu for assistance with spectral analysis. We also thank Karen Carleton for use of the software to calculate spectral location. Tom Cronin, Kevin Omland, Megan Porter, Kate Feller, Nick Friedman and Brian Dalton provided helpful discussions throughout the course of this work. We thank two anonymous reviewers and the editor for their helpful comments on previous versions of this manuscript. We especially thank Eileen Hebets for the invitation to submit to this special issue. This work was funded through a National Science Foundation grant to TCM (#DEB 0718987). Additional support for this work came from the NSF, NCEAS and NESCENT funded "Comparative Phylogenetics in R" workshop attended by JMG.
文摘As complex traits evolve, each component of the trait may be under different selection pressures and could respond independently to distinct evolutionary forces. We used comparative methods to examine patterns of evolution in multiple components of a complex courtship signal in darters, specifically addressing the question of how nuptial coloration evolves across different areas of the body. Using spectral reflectance, we defined 4 broad color classes present on the body and fins of 17 species of freshwater fishes (genus Etheostoma) and quantified differences in hue within each color class. Ancestral state reconstruction suggests that most color traits were expressed in the most recent common ancestor of sampled species and that differences among species are mostly due to losses in coloration. The evolutionary lability of coloration varied across body regions; we found sig- nificant phylogenetic signal for orange color on the body but not for most colors on fins. Finally, patterns of color evolution and hue Of the colors were correlated among the two dorsal fins and between the anterior dorsal and anal fins, but not between any of the fins and the body. The observed patterns support the hypothesis that different components of complex signals may be subject to distinct evolutionary pressures, and suggests that the combination of behavioral displays and morphology in communication may have a strong influence on patterns of signal evolution .
基金We thank Kate Rose for help managing data, the survey participants for judging vividness, C. East- wood for his intellectual contributions, and Bill Cooper and one anonymous reviewer for their constructive comments on a previous version of this MS. NMH was supported by the UC Regents Special Fellowship. JPD was supported by a National Science Foundation (NSF) Graduate Research Fellowship and a fellowship from the UCLA Graduate Division during the course of this study. DTB is supported by NSF-DEB-1119660.
文摘The distance from an approaching threat at which animals initiate flight - flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assess- ment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats [Current Zoology 61 (4): 773-780, 2015].
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)National Key R and D Program of China(2018YFD0900806)National Natural Science Foundation of China(31872234)。
文摘Although the East Asian monsoon is believed to be an important driver for the origin and evolution of the biotas in this region,the association has rarely been rigorously tested.Here,using phylogenetic comparative methods and analyses of key innovations of adaptive traits,we investigated evolutionary patterns of the East Asian cyprinid opsariichthyin-xenocyprinin-cultrin clade;the dominant species in lakes and rivers,which are the typical productions of monsoon climate.Our molecular phylogenetic analyses revealed the relationships as(Opsariichthystribe t(((Oxygaster-tribe t Aphyocypris-tribe)t Metzia-tribe)t(Paralaubuca-tribe t(Squaliobarbus-tribe t(Hypophthalmichthys-tribe t(xenocyprinins t cultrins)))))).Based on Bayesian relaxed-clock methods,we found that origins of the Squaliobarbus-and Hypophthalmichthys-tribes bearing the key adaptation of riverine spawning with drifting eggs occurred 22.5 and 21.1 Mya,respectively.These times are consistent with the Early Miocene origin of major rivers(e.g.,Yangtze River)and the appearance of the East Asian monsoon climate.Diversification of the cultrins,characterized by spawning of adhesive eggs as well as swimming and feeding in lentic waters,were estimated to have evolved 16.6 to 0.2 Mya.This period covers three phases of enhancement of the East Asian monsoon from the Middle Miocene to the Pliocene(around 15–13,10–7,and 3.5 Mya).The habitats of these cultrins and their evolution also suggest the appearance and development of a lake-river environment during those periods.Therefore,our results suggest close relationships between the evolution of these fishes and geological events in East Asia.Further,they provide knowledge that may help facilitate future conservation strategies such as the maintenance of high river flows during dam construction and operation.
基金supported by the National HighTech Research and Development Program of China(No.2006AA020801)the National Natural Science Foundation of China(No.30770525)the Programme of Introducing Talents of Discipline to Universities
文摘A feasible method of combining the concept of fluorescence half-life and the power dependent photo- bleaching rate for characterizing the practical photostability of fluorescent proteins (FPs) was introduced. Furthermore, by using a fluorescent photostability standard, a relative comparison of the photostabilty of FPs from different research groups was proposed, which would be of great benefit for developing novel FPs with optimized emission wavelength, better brightness, and improved photostability. We used rho- damine B as an example to verify this method and evaluate the practical photostability of a far-red FP, mKate-S158C. Experimental results indicated good potential of this method for further study.
基金funded by a Paleontological Society Norman Newel Award,a College of Arts and Sciences Regional Campus Research and Creative Activity Grant from the Ohio State University,a research grant from the Ohio State University at Marion,and startup funds from the Ohio State University to J.C.Some of the ideas for this project were developed while J.Cwas supported by a Meaningful Inquiry grant from the Ohio State University library system.
文摘Geomyoid rodents provide a great study system for the analysis of sexual dimorphism.They are polygynic and many inhabit harsh arid environments thought to promote sexual dimorphism.In fact,there has been extensive work published on the sexual size dimorphism of individual populations and species within this rodent clade.However,little work has been undertaken to assess the evolutionary patterns and processes associated with this sexual dimorphism.We use multivariate analyses of cranial measurements in a phylogenetic framework to determine the distribution of size and shape dimorphism among geomyoids and test for Rensch’s rule.Our results suggest that sexual dimorphism is more common in geomyids than heteromyids,but it is not in fact universal.There is evidence for variation in sexual dimorphism across populations.Additionally,in many taxa,geographic variation appears to overwhelm existing sexual dimorphism.We find support for the repeated independent evolution of shape and size dimorphism across geomyoid taxa,but we do not find support for an association between size and shape dimorphism.There is no evidence for Rensch’s rule in geomyoids,whether at the superfamily or family level.Together,our findings suggest that there is no single explanation for the evolution of sexual dimorphism in geomyoids and that,instead,it is the product of numerous evolutionary events.Future studies incorporating phylogenetic relationships will be necessary to paint a more complete picture of the evolution of sexual dimorphism in geomyoids.
基金the National Science Foundation Graduate Research Fellowship,UW BiologyBurke Museumthe National Science Foundation Postdoctoral Research Fellowship in Biology(DBI-1812126).
文摘Selective pressures favor morphologies that are adapted to distinct ecologies,resulting in trait partition!ng among ecomorphotypes.However,the effects of these selective pressures vary across taxa,especially because morphology is also influenced by factors such as phylogeny,body size,and functional trade-offs.In this study,we examine how these factors impact functional diversification in mammals.It has been proposed that trait partitioning among mammalian ecomorphotypes is less pronoun ced at small body sizes due to biomecha nical,energetic,and environ mental factors that favor a"generalist"body plan,whereas larger taxa exhibit more substantial functional adaptations.We title this the Diverge nee Hypothesis(DH)because it predicts greater morphological divergence among ecomorphotypes at larger body sizes.We test DH by using phylogenetic comparative methods to examine the postcranial skeletons of 129 species of taxonomically diverse,small-tomedium-sized(<15 kg)mammals,which we categorize as either"tree-dwellers"or"ground-dwellers."In some analyses,the morphologies of ground-dwellers and tree-dwellers suggest greater between-group differentiation at larger sizes,providing some evidence for DH.However,this trend is n either particularly strong nor supported by all an alyses.In stead,a more pronoun ced patter n emerges that is distinct from the predictions of DH:within-group phenotypic disparity increases with body size in both ground-dwellers and tree-dwellers,driven by morphological outliers among"medium'-sized mammals.Thus,evolutionary increases in body size are more closely linked to increases in within-locomotor-group disparity tha n to in creases in betwee n-group disparity.We discuss biomechanical and ecological factors that may drive these evolutionary patter ns,and we emphasize the significant evolutionary influences of ecology and body size on phenotypic diversity.
基金a National Science Foundation grant DEB-1556953/1830127 to S.A.P.and P.C.W.
文摘Key inn ovations may allow lin eages access to new resources and facilitate the invasi on of new adaptive zon es,potentially influencing diversificati on patter ns.Many studies have focused on the impact of key inno vations on speciation rates,but far less is known about how they influe nee phe notypic rates and patterns of ecomorphological diversification.We use the repeated evolution of pharyngognathy within acanthomorph fishes,a commonly cited key innovation,as a case study to explore the predicti ons of key inn ovation theory.Specifically,we in vestigate whether transiti ons to phary ngognathy led to shifts in the rate of phenotypic evolution,as well as shifts and/or expansion in the occupation of morphological and dietary space,using a dataset of 8 morphological traits measured across 3,853 species of Acanthomorpha.Analyzing the 6 evolutionarily independent pharyngognathous clades together,we found no evidence to support pharyngognathy as a key innovation;however,comparisons between individual pharyngognathous lineages and their sister clades did reveal some consistent patterns.In morphospace,most pharyngognathous clades cluster in areas that correspond to deeper-bodied morphologies relative to their sister clades,whereas occupying greater areas in dietary space that reflects a more diversified diet Additi on ally,both Cichlidae and Labridae exhibited higher univariate rates of phenotypic evolution compared with their closest relatives.However,few of these results were exceptional relative to our null models.Our results suggest that transitions to pharyngognathy may only be advantageous when combined with additional ecological or intrinsic factors,illustrating the importance of account!ng for lineage-specific effects when testing key innovation hypotheses.Moreover,the challenges we experienced formulating informative comparisons,despite the ideal evolutionary scenario of multiple independent evolutionary origins of pharyngognathous clades,illustrates the complexities involved in quantifying the impact of key innovations.Given the issues of lineage specific effects and rate heterogeneity at macroevolutionary scales we observed,we suggest a reassessment of the expected impacts of key innovations may be warranted.
文摘This article investigates what might be characterised as "the forensic challenge" for criminal adjudication and clarifies its nature and scope. The "challenge" identified is complex, dynamic and multifaceted, encompassing a variety of issues and debates concerning the ways in which forensic science evidence is validated, generated, presented, tested, evaluated and utilised in criminal proceedings. Common law evidentiary principles governing the admissibility of scientific evidence and expert witness testimony are reviewed and the underlying assumptions and potential weaknesses of adversarial trial procedure are critically considered. The discussion is pitched at the generic level of recurring intellectual puzzles, institutional design, regulatory frameworks, procedural structures and processes, macro-policy choices and methodological prescriptions, with the intention of making it relevant to an international audience. Aspects of the procedural law and adjudicative practice of England and Wales, and the regulatory context of UK forensic science, are offered as concrete illustrations with the potential for illuminating comparative extrapolation to other legal systems. In conclusion, the article draws out specific implications for Chinese scholarship, law reform and policymaking in relation to scientific and other expert evidence, and advances a bold suggestion for entertaining an unconventionally expansive conception of "forensic science" and, correspondingly, of the challenges it presents.
基金funded by the National Natural Science Foundation (Nos. 41125018, 41330635)
文摘Gasoline evaporation is an important anthropogenic source of atmospheric volatile organic compounds(VOCs). Total OH reactivity for gasoline vapor was measured from 4 kinds of gasoline for the first time by comparative reactivity method(CRM) using proton transfer reaction mass spectrometer(PTR-MS).Compositions of 56 PAMS(photochemical assessment monitoring station) nonmethane hydrocarbons(NMHCs) were measured for both liquid and headspace of gasoline. We found high abundance of alkenes and aromatics in gasoline. The calculated OH reactivity derived from quantified NMHCs speciation accounted for only 57 ? 4% of total reactivity obtained from CRM method. N-Alkenes, only 6 wt% in liquid gasoline, contributed to 70% of calculated reactivity. We assume that the undetected branched alkenes are the possible reason for the missing reactivity. We suggest that the priority of gasoline quality improvement is to reduce alkenes content in gasoline in term of reactivity-based control.