New insight into the role of exosomes in idiopathic membrane nephropathy

Exosomes,nanoscale extracellular vesicles(EVs)derived from the invagination of the endosomal membrane,are secreted by a majority of cell types.As carriers of DNA,mRNA,proteins,and microRNAs,exosomes are implicated in regulating biological activities under physiological and pathological conditions.Kidney-derived exosomes,which vary in origin and function,may either contribute to the pathogenesis of disease or represent a potential therapeutic resource.Membranous nephropathy(MN),an autoimmune kidney disease characterized by glomerular damage,is a predominant cause of nephrotic syndrome.Notably,MN,especially idiopathic membranous nephropathy(IMN),often results in end-stage renal disease(ESRD),affecting approximately 30%of patients and posing a considerable economic challenge to healthcare systems.Despite substantial research,therapeutic options remain ineffective at halting IMN progression,underscoring the urgent need for innovative strategies.Emerging evidence has implicated exosomes in IMN’s pathophysiology;Providing a fresh perspective for the discovery of novel biomarkers and therapeutic strategies.This review aims to scrutinize recent developments in exosome-related mechanisms in IMN and evaluate their potential as promising therapeutic targets and diagnostic biomarkers,with the hope of catalyzing further investigations into the utility of exosomes in MN,particularly IMN,ultimately contributing to improved patient outcomes in these challenging disease settings.

The electrical design of a membrane antenna for a lunar-based low-frequency radio telescope

Detecting primordial fluctuations from the cosmic dark ages requires extremely large low-frequency radio telescope arrays deployed on the far side of the Moon.The antenna of such an array must be lightweight,easily storable and transportable,deployable on a large scale,durable,and capable of good electrical performance.A membrane antenna is an excellent candidate to meet these criteria.We study the design of a low-frequency membrane antenna for a lunar-based low-frequency(<30 MHz)radio telescope constructed from polyimide film widely used in aerospace applications,owing to its excellent dielectric properties and high stability as a substrate material.We first design and optimize an antenna in free space through dipole deformation and coupling principles,then simulate an antenna on the lunar surface with a simple lunar soil model,yielding an efficiency greater than 90%in the range of 12-19 MHz and greater than 10%in the range of 5-35 MHz.The antenna inherits the omni-directional radiation pattern of a simple dipole antenna in the 5-30 MHz frequency band,giving a large field of view and allowing detection of the 21 cm global signal when used alone.A demonstration prototype is constructed,and its measured electrical property is found to be consistent with simulated results using|S11|measurements.This membrane antenna can potentially fulfill the requirements of a lunar low-frequency array,establishing a solid technical foundation for future large-scale arrays for exploring the cosmic dark ages.

Unraveling the macroevolution of horseshoe bats(Chiroptera: Rhinolophidae: Rhinolophus)

Unraveling the diversification mechanisms of organisms is a fundamental and important macroevolutionary question regarding the diversity,ecological niche, and morphological divergence of life. However, many studies have only explored diversification mechanisms via isolated factors. Here,based on comparative phylogenetic analysis, we performed a macroevolutionary examination of horseshoe bats(Chiroptera: Rhinolophidae:Rhinolophus), to reveal the inter-relationships among diversification, intrinsic/extrinsic factors, and climatic ecological niche characteristics. Results showed a general slowing trajectory during diversification, with two dispersal events from Asia into Southeast Asia and Africa playing key roles in shaping regional heterogeneous diversity. Morphospace expansions of the investigated traits(e.g., body size,echolocation, and climate niche) revealed a decoupled pattern between diversification trajectory and trait divergence, suggesting that other factors(e.g., biotic interactions) potentially played a key role in recent diversification. Based on ancestral traits and pathway analyses, most Rhinolophus lineages belonging to the same region overlapped with each other geographically and were positively associated with the diversification rate, implying a competitive prelude to speciation. Overall, our study showed that multiple approaches need to be integrated to address diversification history. Rather than a single factor, the joint effects of multiple factors(biogeography, environmental drivers, and competition) are responsible for the current diversity patterns in horseshoe bats, and a corresponding multifaceted strategy is recommended to study these patterns in the future.

Adsorption,in vitro digestion and human gut microbiota regulation characteristics of three Poria cocos polysaccharides

Poria cocos(PC)is a famous traditional Chinese medicine(TCM)and a widely used healthcare ingredient,which has antiobesity,enhancing immunity and improving sleep effects.Traditionally,only water-soluble poria polysaccharide(WSP)is extracted and applied for clinical application,while insoluble polysaccharide(alkali-soluble poria polysaccharide,ASP)is discarded as herb residue.However,the whole PC has also been historically utilized as functional herbal food.Considering the beneficial role of dietary fiber and the traditional use of PC,ASP may also contribute substantially to the therapy function of PC.Compared to WSP,little attention has been paid to ASP and ASP modified product carboxymethyl poria polysaccharide(CMP)which has been used as an antitumor adjuvant drug.In this study,the oil,cholesterol,metal ions and polyphenols adsorption ability,in vitro simulated digestive and the gut microbiota fermentation characteristics of WSP,ASP and CMP were studied to evaluate the functional values of three P.cocos polysaccharides(PCPs).The results showed that all three PCPs had good adsorption capacity on cholesterol,polyphenols and metal ions(Cd^(2+)/Zn^(2+)/Mg^(2+)),among which ASP showed the highest capacity than WSP and CMP.The adsorption capacity of all three PCPs on heavy metal ions(Cd^(2+)/Zn^(2+))was stronger than that of non-heavy metal ions(Mg^(2+));The in vitro digestibility of all three PCPs was very low,but WSP was slightly higher than ASP and CMP;Moreover,the indigestible residue of all three PCPs could improve the richness and diversity of gut microbiota,among which ASP had the greatest influence.In general,ASP and CMP could significantly promote the proliferation of some probiotics and inhibit the growth of some harmful bacteria.The gut microbiota diversity of CMP was reduced,but the richness of probiotics,especially Parabacteroides distasonis was significantly enhanced compared with the ASP group,and the growth of harmful bacteria Klebsiella pneumoniae was inhibited after CMP treatment.The short-chain fatty acids(SCFAs)analysis results showed that all three PCPs could significantly promote the production of acetic acid,propionic acid and the total acid content compared with blank control group,and SCFAs producing activity was positively correlated with the proliferative capacity of probiotics.Taken together,the good adsorption characteristics and gut microbiota regulatory activity of ASP may lay foundation for its lipid-lowering and immune-improving function.Additionally,the probiotic effect of CMP and ASP indicated that except for only use the water extract of PC in clinic,CMP and ASP also can be used in healthcare to take full advantage of this valuable medicine.

Molecular phylogeny and divergence time of Trachypithecus： with implications for the taxonomy of T. phayrei

The genus Trachypithecus is the most diverse langur taxon, distributed in southwestern China, south and southeastern Asia. In this study, we include 16 recognized Trachypithecus species to reconstruct the phylogeny with particular concern to the taxonomy of the three subspecies of Z phayrei using multiple genes. Our results support a sister-relationship between Z p. phayrei and T p. shanicus. However, the mitochondrial CYT B gene supported T. p. crepuscula as a distinct species, but the nuclear PRMI gene suggested a closer relationship between T p. crepuscula and T p. phayrei. The incongruence between nuclear and mitochondrial genes suggests that hybridization may have occurred, a fact that would benefit from re-examination using multiple unlinked nuclear genes.

Influence of anchorage length and pretension on the working resistance of rock bolt based on its tensile characteristics

In coal mining roadway support design,the working resistance of the rock bolt is the key factor affecting its maximum support load.Effective improvement of the working resistance is of great significance to roadway support.Based on the rock bolt’s tensile characteristics and the mining roadway surrounding rock deformation,a mechanical model for calculating the working resistance of the rock bolt was established and solved.Taking the mining roadway of the 17102(3)working face at the Panji No.3 Coal Mine of China as a research site,with a quadrilateral section roadway,the influence of pretension and anchorage length on the working resistance of high-strength and ordinary rock bolts in the middle and corner of the roadway is studied.The results show that when the bolt is in the elastic stage,increasing the pretension and anchorage length can effectively improve the working resistance.When the bolt is in the yield and strain-strengthening stages,increasing the pretension and anchorage length cannot effectively improve the working resistance.The influence of pretension and anchorage length on the ordinary and high-strength bolts is similar.The ordinary bolt’s working resistance is approximately 25 kN less than that of the high-strength bolt.When pretension and anchorage length are considered separately,the best pretensions of the high-strength bolt in the middle of the roadway side and the roadway corner are 41.55 and 104.26 kN,respectively,and the best anchorage lengths are 1.54 and 2.12 m,respectively.The best anchorage length of the ordinary bolt is the same as that of the high-strength bolt,and the best pretension for the ordinary bolt in the middle of the roadway side and at the roadway corner is 33.51 and 85.12 kN,respectively.The research results can provide a theoretical basis for supporting the design of quadrilateral mining roadways.

Taxonomic revision of the genus Mesechinus (Mammalia Erinaceidae) with description of a new species

Hedgehogs in the genus Mesechinus （Family Erinaceidae）, which include two currently recognized species （ M. dauuricus and M. hughi）, are distributed from northeast Mongolia to the upper Amur Basin in Russia and adjacent areas in northeast and northern China. In recent years, a population of Mesechinus hedgehogs was discovered from Mt. Gaoligong, southwestern Yunnan, China, far from the known distribution range of the genus. Furthermore, these hedgehogs are the only known population to be distributed at elevations higher than 2 100 m and in sympatry with gymnures. To evaluate the taxonomic status of these hedgehogs, we examined specimens representing Mesechinus taxa in China and further conducted morphometric and karyotypic analyses. Our results supported the existence of four species in China. Specifically, we identified the hedgehogs from Mt. Gaoligong as a new species, Mesechinus wangi sp. nov., and recognized M. miodon, previously considered as a synonym of either M. dauuricus or M. hughi as a distinct species. Interestingly, we observed a supernumerary M4 on all specimens of Mesechinus wangi sp. nov., which is an extremely rare event in the evolution of mammalian dentition.

Castleman disease of the pancreas mimicking pancreatic malignancy on^(68)Ga-DOTATATE and 18F-fluorodeoxyglucose positron emission tomography/computed tomography:A case report

BACKGROUND Castleman disease is an uncommon nonclonal lymphoproliferative disorder,which frequently mimics both benign and malignant abnormalities in several regions.Depending on the number of lymph nodes or regions involved,Castleman disease(CD)varies in diagnosis,treatment and prognosis.It rarely occurs in the pancreas alone without any distinct clinical feature and tends to be confused with pancreatic paraganglioma(PGL),neuroendocrine tumors(NETs),and primary tumors,thus impeding proper diagnosis and treatment.CASE SUMMARY A 28-year-old woman presented with a lesion on the neck of the pancreas,detected by ultrasound during a health examination.Physical examination and laboratory findings were normal.The mass showed hypervascularity on enhanced computed tomography(CT),significantly increased 18F-fluorodeoxyglucose uptake on positron emission tomography(PET)/CT,and slightly increased somatostatin receptor(SSTR)expression on^(68)Ga-DOTATATE PET/CT,suggesting no distant metastases and subdiagnoses such as pancreatic PGL,NET,or primary tumor.Intraoperative pathology suggested lymphatic hyperplasia,and only simple tumor resection was performed.The patient was diagnosed with the hyaline vascular variant of CD,which was confirmed by postoperative immunohistochemistry.The patient was discharged successfully,and no recurrence was observed on regular review.CONCLUSION High glucose uptake and slightly elevated SSTR expression are potentially new diagnostic features of CD of the pancreas.

Species identification of crested gibbons(Nomascus) in captivity in China using karyotyping-and PCR-based approaches

Gibbons and siamangs （Hylobatidae） are well-known for their rapid chromosomal evolution,which has resulted in high speciation rate within the family.On the other hand,distinct karyotypes do not prevent speciation,allowing interbreeding between individuals in captivity,and the unwanted hybrids are ethically problematic as all gibbon species are endangered or critically endangered.Thus,accurate species identification is crucial for captive breeding,particularly in China where studbooks are unavailable.Identification based on external morphology is difficult,especially for hybrids,because species are usually similar in appearance.In this study,we employed G-banding karyotyping and fluorescence in situ hybridization （FISH） as well as a PCR-based approach to examine karyotypic characteristics and identify crested gibbons of the genus Nomascus from zoos and nature reserves in China.We characterized and identified five karyotypes from 21 individuals of Nomascus.Using karyotypes and mitochondrial and nuclear genes,we identified three purebred species and three hybrids,including one F2 hybrid between N.gabriellae and N.siki.Our results also supported that N.leucogenys and N.siki shared the same inversion on chromosome 7,which resolves arguments from previous studies.Our results demonstrated that both karyotyping and DNA-based approaches were suitable for identifying purebred species,though neither was ideal for hybrid identification.The advantages and disadvantages of both approaches are discussed.Our results further highlight the importance of animal ethics and welfare,which are critical for endangered species in captivity.

Molecular phylogeny and divergence time of Trachypithecus:with implications for the taxonomy of T.phayrei

The genus Trachypithecus is the most diverse langur taxon,distributed in southwestern China,south and southeastern Asia.In this study,we include 16 recognized Trachypithecus species to reconstruct the phylogeny with particular concern to the taxonomy of the three subspecies of T.phayrei using multiple genes.Our results support a sister-relationship between T.p.phayrei and T.p.shanicus.However,the mitochondrial CYT B gene supported T.p.crepuscula as a distinct species,but the nuclear PRM1 gene suggested a closer relationship between T.p.crepuscula and T.p.phayrei.The incongruence between nuclear and mitochondrial genes suggests that hybridization may have occurred,a fact that would benefit from re-examination using multiple unlinked nuclear genes.

页岩油组分对油水界面性质的影响

探讨了页岩油组分对油水界面性质的影响,油水界面性质对非常规储层中碳氢化合物的回收和运移起着至关重要的作用。研究考察了页岩油的组分含量变化对油水界面性质的影响,包括饱和分、芳香分、胶质、沥青质和蜡的变化。系统评价了不同组分质量分数下油水界面张力和界面模量,建立了页岩油组成与界面性质之间的相关性。结果表明,沥青质和胶质的存在显著影响油水界面性质,导致界面张力降低,质量分数为1%的沥青质和胶质组分分别可将平衡界面张力降低至22.48 mN/m和19.42 mN/m;沥青质对界面膜的稳定起到主要作用,不同胶质/沥青质(R/A)含量下对界面张力和界面模量大小改善程度不相同;蜡组分没有降低界面张力的能力,但与胶质-沥青质存在协同作用,可提高界面膜的稳定性,降低高胶质/沥青质(R/A)比例下的竞争吸附,当R/A为10时,胶质/沥青质-蜡的平衡界面张力为17.06 mN/m、黏性模量为6.42 mN/m、弹性模量为36.98 mN/m、扩张模量为37.61 mN/m。这些发现为页岩油组成与油水界面性质之间的复杂关系提供了有价值的见解,有助于开发更有效的提高采收率(EOR)技术和更好地理解非常规储层中的多相流动行为。

How many species of Apodemus and Rattus occur in China？ A survey based on mitochondrial cyt b and morphological analyses

Apodemus （mice） and Rattus （rats） are the top rodent reservoirs for zoonoses in China,yet little is known about their diversity.We reexamined the alpha diversity of these two genera based on a new collection of specimens from China and their cyt b sequences in GenBank.We also tested whether species could be identified using external and craniodental measurements exclusively.Measurements from 147 specimens of Apodemus and 233 specimens of Rattus were used for morphological comparisons.We analysed 74 cyt b sequences of Apodemus and 100 cyt b sequences of Rattus to facilitate phylogenetic estimations.Results demonstrated that nine species of Apodemus and seven species of Rattus,plus a new subspecies of Rattus nitidus,are distributed in China.Principal component analysis using external and craniodental measurements revealed that measurements alone could not separate the recognized species.The occurrence of Rattus pyctoris in China remains uncertain.

A new genus of Asiatic short-tailed shrew (Soricidae, Eulipotyphla) based on molecular and morphological comparisons

Blarinellini is a tribe of soricine shrews comprised of nine fossil genera and one extant genus. Blarinelline shrews were once widely distributed throughout Eurasia and North America, though only members of the Asiatic short-tailed shrew genus Blarinella currently persist （mostly in southwestern China and adjacent areas）. Only three forms of Blarinella have been recognized as either species or subspecies However, recent molecular studies indicated a strikingly deep divergence within the genus, implying the existence of a distinct genus-level lineage. We sequenced the complete mitochondrial genomes and one nuclear gene of three Asiatic short-tailed and two North American shrews and analyzed them morphometrically and morphologically. Our molecular analyses revealed that specimens ascribed to B. griselda formed two deeply diverged lineages, one a close relative to B. quadraticauda, whereas the other--comprised of topotype specimens from southern Gansu-iverged from other Blarinella in the middle Miocene （ca. 18.2 million years ago （Ma）, 95% confidence interval=13.4-23.6 Ma）. Although the skulls were similarly shaped in both lineages, we observed several diagnostic characteristics, including the shape of the upper p4. In consideration of the molecular and morphological evidence, we recognize B. griselda as the sole species of a new genus, namely, Pantherina gen. nov. Interestingly, some characteristics of Pantherina griselda are more similar to fossil genera, suggesting it represents an evolutionarily more primitive form than Blarinella.Recognition of this new genus sheds light on the systematics and evolutionary history of the tribe Blarinellini throughout Eurasia and North America.

In situ transmission electron microscopy and artificial intelligence enabled data analytics for energy materials

Energy materials are vital to energy conversion and storage devices that make renewable resources viable for electrification technologies. In situ transmission electron microscopy(TEM) is a powerful approach to characterize the dynamic evolution of material structure, morphology, and chemistry at the atomic scale in real time and in operando. In this review, recent advancements of in situ TEM techniques for studying energy materials, including catalysts, batteries, photovoltaics, and thermoelectrics, are systematically discussed and summarized. The topics include a broad range of material transformations that are in situ stimulated by heating, biasing, lighting, electron-beam illuminating, and cryocooling under vacuum, liquid, or gas environments within TEM, as well as the mechanistic understanding of the associated solid-solid, solid-liquid, and solid-gas reactions elucidated by in situ TEM examination and operando measurements. Special focus is also put on the emerging progress of artificial intelligence enabled microscopy data analytics, including machine learning enhanced tools for retrieving useful information from massive TEM imaging, diffraction, and spectroscopy datasets, highlighting its merits and potential for automated in situ TEM experimentation and analysis. Finally, the pressing challenges and future perspectives on in situ TEM study for energy-related materials are discussed.

Fast Adaptive Support-Weight Stereo Matching Algorithm

Adaptive support-weight (ASW) stereo matching algorithm is widely used in the field of three-dimensional (3D) reconstruction owing to its relatively high matching accuracy.However,since all the weight coefficients need to be calculated in the whole disparity range for each pixel,the algorithm is extremely time-consuming.To solve this problem,a fast ASW algorithm is proposed using twice aggregation.First,a novel weight coefficient which adapts cosine function to satisfy the weight distribution discipline is proposed to accomplish the first cost aggregation.Then,the disparity range is divided into several sub-ranges and local optimal disparities are selected from each of them.For each pixel,only the ASW at the location of local optimal disparities is calculated,and thus,the complexity of the algorithm is greatly reduced.Experimental results show that the proposed algorithm can reduce the amount of calculation by 70% and improve the matching accuracy by 6% for the 15 images on Middlebury Website on average.

高迁移率族蛋白A2与原发性肝细胞癌患者临床病理特征及其预后的关系

目的探讨高迁移率族蛋白A2(HMGA2)表达与原发性肝细胞癌患者临床病理特征及其预后的关系。方法选取2010年1月-2013年1月在西南医科大学附属医院肝胆外科行手术切除的肝细胞癌患者120例。以免疫组织化学法检测患者手术切除标本的癌组织、癌旁组织及正常肝组织中HMGA2的表达,记录患者临床病理特征并随访。统计分析HMGA2阳性表达与患者临床病理特征的关系,以及对患者预后的影响。结果免疫组织化学结果发现,HMGA2阳性表达呈棕黄色或棕褐色颗粒,主要定位于肿瘤细胞的细胞核。肝癌组织HMGA2阳性率比正常肝组织和癌旁组织高(P<0.05)。HMGA2阳性表达率在临床分期、有肝门淋巴结转移及肝内转移肝细胞癌患者中较高(P<0.05)。多因素Logistic回归模型结果显示,临床分期、肝门淋巴结转移及肝内转移均是影响HMGA2阳性表达的独立危险因素(P<0.05)。两组患者的3年生存率比较,差异有统计学意义(P<0.05)。结论HMGA2阳性患者预后明显较差,HMGA2可作为判断肝细胞癌患者预后的一个潜在指标。

基于深度学习的翼状胬肉自动分类系统研究

目的:评估基于深度学习的翼状胬肉自动分类诊断系统的应用价值。方法:在2020-05/2021-04期间,从南京医科大学附属眼科医院共收集750张翼状胬肉正常、观察期和手术期眼前节图片。在原始数据集和增强数据集上分别训练7个三分类模型。测试临床470张图片,比较数据增强前后模型的泛化能力,确定可用于翼状胬肉自动分类系统的最好模型。结果:在原始数据集上训练最好模型的灵敏度平均值为92.55%,特异度平均值为96.86%,AUC平均值为94.70%。数据增强后,不同模型灵敏度、特异度和AUC平均提升3.7%、1.9%和2.7%。在增强数据集上训练的EfficientNetB7模型灵敏度平均值为93.63%,特异度平均值为97.34%,AUC平均值为95.47%。结论:在增强数据集上训练的EfficientNetB7模型取得最好的分类效果,可用于翼状胬肉自动分类系统。该自动分类系统能较好地诊断翼状胬肉疾病,有望成为基层医疗的有效筛查工具,也为翼状胬肉的细化分级研究提供参考。

AGRICULTURAL GREEN DEVELOPMENT TO ACHIEVE FOOD SECURITY AND CARBON REDUCTION IN THE CONTEXT OF CHINA'S DUAL CARBON GOALS

The agricultural sector,a major source of greenhouse gas emissions,and emissions from agriculture must be reduced substantially to achieve carbon(C)neutrality.Based on a literature analysis and other research results,this study investigated the effects and prospects of C reduction in agricultural systems under different scenarios(i.e.,methods and approaches)in the context of China's dual C goals,as those working in the agricultural sector have yet to reach a consensus on how to move forward.Different views,standards,and countermeasures were analyzed to provide a reference for agricultural action supporting China's C neutrality goal.

Preparation of SiC coated graphite composite powders by nitriding combustion synthesis

Ceramic-coated graphite powders are considered as effective raw materials to fabricate three-dimensional continuous ceramic skeleton-reinforced graphite matrix composites which can overcome their inherent poor densification and improve their mechanical and antioxidation properties.However,the morphology and thickness regulation of ceramic coatings on graphite particles are still a great challenge.Herein,SiC-coated graphite(graphite@SiC)powders were prepared by nitriding combustion synthesis using Si and graphited mesocarbon microbead(MCMB)as raw powders with polytetrafluoroethylene(PTFE)as a promoter.The effects of the PTFE content and the Si/MCMB molar ratio on the phase composition and coating morphology were investigated.The phase transition and microstructure evolution of a combustion synthesis(CS)process were revealed by a gas-released quenching experiment.When the Si/MCMB molar ratio was 1:3 and the PTFE content was 10 wt%,the thickness of the SiC coating synthesized under 2 MPa N_(2)reached 1.14μm.The corresponding sintered graphite@SiC composite had relative density of 99.2%and flexural strength of 231 MPa,accompanied by a significant improvement in high-temperature antioxidation properties.The as-synthesized graphite@SiC powders with good sinterability and antioxidation properties show great promise for applications in the nuclear industry and other extreme fields.

Mitogenome and phylogenetic analyses support rapid diversification among species groups of small-eared shrews genus Cryptotis(Mammalia:Eulipotyphla:Soricidae)

The small-eared shrew genus Cryptotis is the third largest in the family Soricidae and occurs in North,Central,and northern South America.In Mexico and Central and South America,most species inhabit geographically isolated moist,montane habitats at middle and high elevations in a typical sky-island pattern.The 49 recognized species have been partitioned into as many as six species groups based on morphological and molecular phylogenetic studies.The relationships among these species groups are poorly resolved,and their evolutionary histories,including migration patterns and locomotor adaptations,remain unclear.Herein,we provide a new phylogeny incorporating complete mitochondrial genomes(mitogenomes)and supermatrix approach.We compared different evolutionary scenarios using approximately unbiased(AU),Kishino-Hasegawa(KH),and Shimodaira-Hasegawa(SH)statistical tests.The phylogenetic hypothesis based on mitogenomes revealed novel relationships supporting a basal position for the Cryptotis parvusgroup in the genus,and a close relationship between C.gracilis and one clade of the C.thomasi-group.The former relationship is consistent with the least derived humerus morphology and northern distribution of the species.The latter relationship i mplies multiple migrations between Central and South America.The lack of fine resolution for the species group relationships may be due partly to the lack of taxon sampling.In contrast,multi-approach analyses suggest that the unresolved relationships may be a result of rapid diversification during the early stages of Cryptotis evolution.