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Traditional Dipodomys (sub)species identification uses geography, phenotype, and external/skull measurements. Such measurements are correlated with size and thus redundant. I assessed the value of scaled cranial shape, based on two‐dimensional landmarks (analyzed using geometric morphometric methods) in distinguishing Dipodomys taxa, and in summarizing their variation. My dataset includes 601 adult specimens from 20 species (49 operational taxonomic units ‐ OTUs) across 190 localities. Cranial shape was highly useful in classifying Dipodomys taxa without considering geography. The auditory bulla was the most variable region—taxa differed in its hypertrophy, accompanied by different degrees of nearby structure crowding. Cranial shape was weakly allometric, with no significant sexual dimorphism. Weak size dimorphism was detected. (Sub)specific taxonomy is not reflective of shape variation, as the number of subspecies per species is not associated with disparity. Shape had significant phylogenetic signal, but subspecies did not always cluster with conspecifics and species did not always cluster according to phylogenetic relationship/taxonomy. Shape variation was correlated with climate, and species differed in morphological disparity and degree of specialization, which may contribute to divergence in shape variation patterns from phylogeny. D. deserti was the most specialized species, diverging greatly from the genus mean; D. heermanni was the least specialized. This study provides new insights into morphological variation of North American keystone species, several of conservation interest, for example, D. heermanni berkeleyensis, D. h. dixoni, D. nitratoides brevinasus, and D. n. nitratoides. [ABSTRACT FROM AUTHOR]

Aim: Species‐level traits, such as body and range sizes, are important correlates of extinction risk. However, both are often related and are driven by environmental factors. Here, we elucidated links between environmental factors, body size, range size and susceptibility to extinction, across the whole order of rodents. Location: Global. Time period: Current. Major taxa studied: Rodents (order Rodentia). Methods: We compiled an unprecedentedly large database of rodent morphology, phylogeny, range size, conservation status, global climate and normalized difference vegetation index (NDVI), comprising >86% of all described species. Using phylogenetic regressions, we initially explored the environmental factors driving body size. Next, we modelled the relationship between body size and range size. From this relationship, we computed and mapped (at the assemblage level) an index of relative range size, corresponding to the deviation from the expected range size of each species, given its body size. Finally, we tested whether relative range was correlated with the risk of extinction of the species derived from an assessment by the International Union for Conservation of Nature. Results: We found that, contrary to the expectations of Bergmann's rule, the body size of rodents was mostly influenced by variation in NDVI (rather than latitude/temperature). Body size, in turn, imposed a constraint on species range size, as evidenced by a triangular relationship that was segmented at the lower bound. The relative species range size derived from this relationship highlighted four geographical regions where rodents with small relative range were concentrated globally. We demonstrated that lower relative range size was associated with increased risk of extinction. Main conclusions: Species that, given their body size, are distributed across ranges that are smaller than expected have elevated extinction risk. Therefore, investigating the relationships between environmental drivers, body size and range size might help to detect species that could become threatened in the near future. [ABSTRACT FROM AUTHOR]

An approach guided by physical consistency in determining the general forms of D‐dimensional kinetic energy density functionals (KEDF) has been demonstrated previously, producing an expansion which contains the majority of the known one‐point KEDF forms. It has also been shown that any noninteracting KEDF must necessarily have a homogeneity degree of 2 in coordinate scaling, and that the ratio of the collective KED to electron density must approach the ionization energy as r→∞. This article demonstrates that the scaling condition is already satisfied in the general expansion despite not being conceived with the scaling as a constraint, and that the second condition places a restriction on the expansion terms of the KED. The discussion is extended as well for some known KEDs for comparison. [ABSTRACT FROM AUTHOR]

Aim: We test whether geographical variation in the length of appendages in rodent species follows predictions of Allen's rule (a positive relationship between appendage length and temperature) at a broad taxonomic scale (order Rodentia). We also test whether the applicability of this rule varies based on the unit of analysis (species or assemblage), the appendage examined (tail, hind foot, ear), body size, occupied habitat, geographical range size, life mode and saltatorial ability. Location: World‐wide. Time period: Current. Major taxa studied: Rodents (order Rodentia). Methods: We assembled data on the morphology, ecology and phylogeny for ≤ 2,212 rodent species, representing c. 86% of all the described rodent species and c. 95% of the described genera. We tested the predicted Allen's rule associations among size‐corrected appendage lengths and both latitudinal and climatic variables (temperature and precipitation). We applied a cross‐species approach based on phylogenetic regressions and a cross‐assemblage approach based on spatial regressions in equal‐area 1.5° grid cells. Results: Support for Allen's rule was greatest for the tail and was stronger across assemblages than across species. We detected a negative relationship between tail length and (absolute) latitude, which was accounted for by a positive association between tail length and temperature of the coldest month. This association was greatest in desert species. In addition, we observed a negative relationship between ear length and precipitation. Main conclusions: In rodents, Allen's rule is confirmed only for tails, and this association seems to be driven by adaptation to the cold, rather than warm temperatures. Habitat type seems to influence conformity to this rule. Conformity to Allen's rule is likely to be the result of complex evolutionary trade‐offs between temperature regulation and other essential species traits. [ABSTRACT FROM AUTHOR]

Aim: The International Union for Conservation of Nature (IUCN) expert range maps and the Global Biodiversity Information Facility (GBIF) species occurrence data are commonly used to estimate species' geographic range. Macroecological studies often cross‐reference geographic range data with a climate dataset, to extract the mean environmental conditions encountered by a species within its geographic range. We aimed to assess the consistency of the environmental data estimates derived from IUCN versus GBIF geographic range data, and to test whether such differences may affect estimates of ecogeographical relationships, such as Bergmann's rule. Location: Worldwide. Time period: Around 2000. Taxa: Rodents (Rodentia). Methods: We first assessed the correlation between environmental data estimates (19 bioclimatic variables and elevation) derived from IUCN versus GBIF geographic range data of 1,315 rodent species, comparing how range size, conservation status, habitat, zoogeographic realm or elevation changed these correlations. Then, we compared the association between body mass and climate (mean temperature and precipitation) when the latter are derived from IUCN or GBIF data. Results: There was high correlation between environmental data estimates derived from IUCN versus GBIF data, especially when excluding GBIF occurrences outside of IUCN polygons. Species' characteristics, or using the mean or median, did not change the consistency between estimates. Overall, GBIF occurrence data and IUCN range maps produced similar patterns of body mass—climate correlations. Main conclusions: At the large spatial and taxonomic scale employed in this study, there does not seem to be any considerable differences in the average environmental data estimates derived from IUCN versus GBIF geographic range data. This result indicates that both sources of geographic range data could be used independently or in concert for macroecological inferences that involve summarizing species' niches by a single estimate of the average of their used environments. [ABSTRACT FROM AUTHOR]

Careful collection and organization of biological specimens and their associated data are at the core of field research (e.g., ecology, genetics). Fieldwork data are often collected by handwriting or unsystematically via an electronic device (e.g., laptop), a process that is time‐intensive, disorganized, and may lead to transcription errors, as data are copied to a more permanent repository. SamplEase is an iOS and Android application that is designed to ease the process of collecting biological specimen data in the field (data associated with biological samples, such as location, age, and sex). In addition to biological specimen data, SamplEase allows for the assignment of photographs to each collected sample, which provides visual records of each specimen in its environment. SamplEase outputs biological specimen data in a tabular format, facilitating subsequent analyses and dissemination. Despite the simplicity of SamplEase, no similar data management application is readily available for researchers. SamplEase is an iOS and Android application that is designed to ease the process of collecting biological specimen data in the field. SamplEase also outputs biological specimen data in a tabular format, facilitating subsequent analyses and dissemination. [ABSTRACT FROM AUTHOR]

Musladin-Lueke syndrome ( MLS), previously termed Chinese Beagle syndrome, is an autosomal-recessive connective tissue disorder characterized by extensive fibrosis of the skin and joints that was first identified in Beagles in the 1970s. Recent research identified a founder mutation (c.660C>T; p.R221C) in the ADAMTSL2 gene in Beagles with MLS. Here, we report the detailed clinical phenotype and laboratory findings in 2 Beagles affected with MLS. We discuss these findings in relation to the human disorder geleophysic dysplasia ( GD), which also arises from recessive ADAMTSL2 mutations, and recent findings in Adamtsl2-deficient mice. [ABSTRACT FROM AUTHOR]

Summary. Sperm-cell volume, measured electronically by cell counter, is a parameter providing information about the state and integrity of the plasma membrane by determining cell osmotic reactivity (swelling level). Electronic volume measurement is a modification of the hypo-osmotic swelling test, based on the increase in sperm volume in response to hypo-osmotic stress. In this study the volumetric method was applied to bull ejaculates, and the relationships of volumetric parameters, osmolality of seminal plasma, and concentration of sodium and potassium ions in seminal plasma, with the nonreturn rate (NRR) were examined. Significant correlations were found between volumetric parameters, conventional spermatological parameters, and NRR. The relative volume shift of the mean volume correlated significantly with motility before and after thawing (P < 0.05). NRR correlated significantly with iso-osmotic cell volume (- 0.49; P < 0.05) and with the relative volume shift (0.51, P < 0.05). The prediction level of regression models was improved when volumetric parameters (iso-osmotic cell volume) were included in the multiple regression model. Therefore, using electronic volume measurement as a component for fast, correct and valid (up to 50 000 cells), recording sperm-cell population may help to evaluate ejaculate quality more precisely. [ABSTRACT FROM AUTHOR]