Variation and Sexual Dimorphism of Body Size in the Plateau Brown Frog along an Altitudinal Gradient

Variation in body size and sexual size dimorphism（SSD） can have important consequences for animal ecology, behavior, population dynamics and the evolution of life-history traits. Organisms are expected to be larger in colder climate（i.e., Bergmann＇s rule） and SSD varies with body size（i.e., Rensch＇s rule）. However, the underlying mechanisms are still elusive. The plateau brown frog（Rana kukunoris）, a medium-sized anuran species with femalebiased SSD, is endemic to the Qinghai-Tibetan Plateau（QTP）. From 1797 m（Maoxiang＇ping） to 3453 m（Heihe＇qiao） in the eastern margin of the QTP, we surveyed 10 populations of R. kukunoris and collected phalanges and snout vent length（SVL） data for 258 adult individuals（199 males versus 59 females）. Based on these data, we explored how body size and SSD varying along the altitudinal gradient and examined the corresponding effects of temperature. We found body size to be larger at higher altitude for males but not for females, with likely effects from the temperature on the variation in male body size. Sex differences in growth rates may be the main cause of the variation in SSD. Our results suggested that only males follow the Bergmann＇s rule and variation in SSD of R. kukunoris do not support the Rensch＇s rule and its inverse. Therefore, the variations of body size can be different between sexes and the applicability of both Bergmann＇s rule and Rensch＇s rule should depend on species and environment where they live.

Geometrical Dimensional Effect on Natural Frequency of Single Layer Graphene in Armchair Configuration

Graphene has remarkable strength,such as yield strength and elastic constant.The dynamic behaviour of graphene sheet is affected by geometrical variation in atomic arrangement.This paper introduced graphene with armchair atomic structure for estimating fundamental natural frequencies.The presented analysis can be useful for the possible high frequency nanomechanical resonator systems.The analytical formulation,based on classical plate theory and continuum solid modelling based finite element method have been performed for estimation of fundamental natural frequencies of single layer graphene sheet(SGLS)with different boundary conditions.The free edge and clamped edge boundary conditions have been considered.For simplifying analytical formulations,Blevins approach for dynamic solution has been adopted and for validating analytical results.The finite element analysis of SLGS has been performed using ANSYS software.The effect of variation in geometrical parameters in terms of width and length of SLGS has been analysed for realization of ultra-high frequency based nanomechanical resonator systems.

Mesoplasticity Approach to Studies of the Cutting Mechanism in Ultra-precision Machining

There have been various theoretical attempts by researchers worldwide to link up different scales of plasticity studies from the nano-, micro- and macro-scale of observation, based on molecular dynamics, crystal plasticity and continuum mechanics. Very few attempts, however, have been reported in ultra-precision machining studies. A mesoplasticity approach advocated by Lee and Yang is adopted by the authors and is successfully applied to studies of the micro-cutting mechanisms in ultra-precision machining. Traditionally, the shear angle in metal cutting, as well as the cutting force variation, can only be determined from cutting tests. In the pioneering work of the authors, the use of mesoplasticity theory enables prediction of the fluctuation of the shear angle and micro-cutting force, shear band formation, chip morphology in diamond turning and size effect in nano-indentation. These findings are verified by experiments. The mesoplasticity formulation opens up a new direction of studies to enable how the plastic behaviour of materials and their constitutive representations in deformation processing, such as machining can be predicted, assessed and deduced from the basic properties of the materials measurable at the microscale.

Chemical characterization of size-resolved aerosols in four seasons and hazy days in the megacity Beijing of China

Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM10 and PM1.8mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m^3, respectively,throughout the measurement, with seasonal variation： nearly two times higher in autumn than in summer and spring. Serious fine particle pollution occurred in winter with the PM1.8/PM10 ratio of 0.63, which was higher than other seasons. The size distribution of PM showed obvious seasonal and diurnal variation, with a smaller fine mode peak in spring and in the daytime. OM（organic matter = 1.6 × OC（organic carbon）） and SIA（secondary inorganic aerosol） were major components of fine particles, while OM, SIA and Ca^2＋were major components in coarse particles. Moreover, secondary components, mainly SOA（secondary organic aerosol） and SIA,accounted for 46%-96% of each size bin in fine particles, which meant that secondary pollution existed all year. Sulfates and nitrates, primarily in the form of（NH4）2SO4, NH4NO3, Ca SO4, Na2SO4 and K2SO4, calculated by the model ISORROPIA II, were major components of the solid phase in fine particles. The PM concentration and size distribution were similar in the four seasons on non-haze days, while large differences occurred on haze days, which indicated seasonal variation of PM concentration and size distribution were dominated by haze days. The SIA concentrations and fractions of nearly all size bins were higher on haze days than on non-haze days, which was attributed to heterogeneous aqueous reactions on haze days in the four seasons.

Exceptionally Preserved Conodont Natural Assemblages from the Middle Triassic Luoping Biota,Yunnan Province,China:Implications for Architecture of Conodont Feeding Apparatus

Articulated natural assemblages contain direct evidence of the element numbers,morphologies,positions and structures for reconstructing the feeding apparatuses of conodont animals,but these kind of materials are very rare in fossil records.Here we report ten new conodont natural assemblages from Member II of the Guanling Formation in Luoping County,eastern Yunnan Province,southwestern China.These assemblages were obtained from the fossil-bearing layers of the Luoping Biota,dated to the early Middle Triassic Anisian stage(Pelsonian substage).These fossiliferous laminated limestones mainly consist of calcites and dolomites,with platy clay minerals and pyrites as subordinate components,indicating that the conodont assemblages were preserved in a lower energy and anoxic sedimentary environment.The new natural assemblages preserve the primary collapse orientations of the Nicoraella feeding apparatus from the Luoping Biota,showing the relative original positions of the S,M and P elements,that could be further used to refine the architecture of this apparatus in space variable M elements and the position unclear P1 elements.Integrating previously reported three-dimensional and bilaterally symmetrical fused clusters,we statistically analyze the size of the positional homogenous elements within different sized materials,in particular S4,S3,or S2 elements,indicates that elements ontogenic changes do not affect the apparatus architecture.Architecture of Nicoraella apparatus remains stable in the process of ontogeny,so our reconstructed model is credible.It is the first time that ample types of materials have been used to restore a conodont apparatus within one genus,namely natural assemblages(articulated and disarticulated),fused clusters(articulated,disarticulated,compressed,and relatively three-dimensional),and abundant discrete elements,respectively.These materials together record the most complete information on architecture in the gondolelloid apparatuses,thus enabling us to reconstruct a reliable fifteen-element apparatus and propose it as a standard template for gondolelloid apparatus reconstruction.

Further geometric morphometric analysis on the genus Eysarcoris(Hemiptera:Pentatomidae) from China

Further geometric morphometric analysis of the genus Eysarcoris was done based on the former studies to classified the nine Eysarcoris species from China. In this study, six characters, such as forewing, hindwing, pygophore, head, pronotum and scutellum, were selected to investigate the shape variation of Eysarcoris. Significant divergence in the shapes of the six characters was observed among the species（p 〈 0.05）. For all methods, phenetic similarity based on the six characters agrees with the current status of the genus. The cluster analysis of eight species are consistent with the traditional morphological studies. CVA analysis also shows that the values of the six characters are not equal in taxonomy. Pygophore, forewing, hindwing and pronotum play more important roles in the classification.