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202 result(s) for "Demos, Terrence C."
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Molecular phylogenetics of the African horseshoe bats (Chiroptera: Rhinolophidae): expanded geographic and taxonomic sampling of the Afrotropics
Background The Old World insectivorous bat genus Rhinolophus is highly speciose. Over the last 15 years, the number of its recognized species has grown from 77 to 106, but knowledge of their interrelationships has not kept pace. Species limits and phylogenetic relationships of this morphologically conservative group remain problematic due both to poor sampling across the Afrotropics and to repeated instances of mitochondrial-nuclear discordance. Recent intensive surveys in East Africa and neighboring regions, coupled with parallel studies by others in West Africa and in Southern Africa, offer a new basis for understanding its evolutionary history. Results We investigated phylogenetic relationships and intraspecific genetic variation in the Afro-Palearctic clade of Rhinolophidae using broad sampling. We sequenced mitochondrial cytochrome- b (1140 bp) and four independent and informative nuclear introns (2611 bp) for 213 individuals and incorporated sequence data from 210 additional individuals on GenBank that together represent 24 of the 33 currently recognized Afrotropical Rhinolophus species. We addressed the widespread occurrence of mito-nuclear discordance in Rhinolophus by inferring concatenated and species tree phylogenies using only the nuclear data. Well resolved mitochondrial, concatenated nuclear, and species trees revealed phylogenetic relationships and population structure of the Afrotropical species and species groups. Conclusions Multiple well-supported and deeply divergent lineages were resolved in each of the six African Rhinolophus species groups analyzed, suggesting as many as 12 undescribed cryptic species; these include several instances of sympatry among close relatives. Coalescent lineage delimitation offered support for new undescribed lineages in four of the six African groups in this study. On the other hand, two to five currently recognized species may be invalid based on combined mitochondrial and/or nuclear phylogenetic analyses. Validation of these cryptic lineages as species and formal relegation of current names to synonymy will require integrative taxonomic assessments involving morphology, ecology, acoustics, distribution, and behavior. The resulting phylogenetic framework offers a powerful basis for addressing questions regarding their ecology and evolution.
Ecology and Host Identity Outweigh Evolutionary History in Shaping the Bat Microbiome
This study is the first to provide a comprehensive survey of bacterial symbionts from multiple anatomical sites across a broad taxonomic range of Afrotropical bats, demonstrating significant associations between the bat microbiome and anatomical site, geographic locality, and host identity—but not evolutionary history. This study provides a framework for future systems biology approaches to examine host-symbiont relationships across broad taxonomic scales, emphasizing the need to elucidate the interplay between host ecology and evolutionary history in shaping the microbiome of different anatomical sites. Recent studies of mammalian microbiomes have identified strong phylogenetic effects on bacterial community composition. Bats (Mammalia: Chiroptera) are among the most speciose mammals on the planet and the only mammal capable of true flight. We examined 1,236 16S rRNA amplicon libraries of the gut, oral, and skin microbiota from 497 Afrotropical bats (representing 9 families, 20 genera, and 31 species) to assess the extent to which host ecology and phylogeny predict microbial community similarity in bats. In contrast to recent studies of host-microbe associations in other mammals, we found no correlation between chiropteran phylogeny and bacterial community dissimilarity across the three anatomical sites sampled. For all anatomical sites, we found host species identity and geographic locality to be strong predictors of microbial community composition and observed a positive correlation between elevation and bacterial richness. Last, we identified significantly different bacterial associations within the gut microbiota of insectivorous and frugivorous bats. We conclude that the gut, oral, and skin microbiota of bats are shaped predominantly by ecological factors and do not exhibit the same degree of phylosymbiosis observed in other mammals. IMPORTANCE This study is the first to provide a comprehensive survey of bacterial symbionts from multiple anatomical sites across a broad taxonomic range of Afrotropical bats, demonstrating significant associations between the bat microbiome and anatomical site, geographic locality, and host identity—but not evolutionary history. This study provides a framework for future systems biology approaches to examine host-symbiont relationships across broad taxonomic scales, emphasizing the need to elucidate the interplay between host ecology and evolutionary history in shaping the microbiome of different anatomical sites.
Morphological Stasis in Wing Traits Despite Species Diversification in African and Malagasy Miniopterus Bats
Islands often give rise to adaptive radiations, owing to the absence of mainland competitors and predators. The long‐fingered bats ( Miniopterus spp.) provide an opportunity to examine this pattern, as the genus includes sister radiations on Madagascar and on the African mainland. We measured wing elements related to flight in these two Miniopterus sister clades: one with 12 species from Madagascar and the other with nine species from Kenya, representing a comparable area of continental Africa. Principal component analysis revealed that Miniopterus species cluster within a narrow region of morphospace, with PC1 representing a size gradient that explains 93.6% of the variance in seven wing measurements. A phylomorphospace analysis integrating a resolved species phylogeny demonstrated that closely related species often occupy similar regions of morphospace, particularly among the smaller Malagasy taxa. Euclidean distance matrices showed similar nearest, average, and farthest neighbor values between Kenya and Madagascar, indicating strong morphological resemblance. Multivariate dispersion analysis yielded an observed mean dispersion of 1.8137, which did not significantly differ from a randomized expectation ( p = 0.08819), suggesting that species are not more regularly or unevenly distributed than expected by chance. These findings indicate limited shape divergence in wing morphology between these two Miniopterus radiations. This work highlights the complexity of detecting adaptive patterns and suggests the need to incorporate broader ecological and behavioral data when studying diversification in bats.
Comparative Population Genomics of African Montane Forest Mammals Support Population Persistence across a Climatic Gradient and Quaternary Climatic Cycles
The Eastern Afromontane biodiversity hotspot (EABH) has the highest concentration of biodiversity in tropical Africa, yet few studies have investigated recent historical diversification processes in EABH lineages. Herein, we analyze restriction-site associated DNA-sequences (RAD-Seq) to study recent historical processes in co-distributed mouse (Hylomyscus) and shrew (Sylvisorex) species complexes, with an aim to better determine how historical paleoenvironmental processes might have contributed to the EABH's high diversity. We analyzed complete SNP matrices of > 50,000 RAD loci to delineate populations, reconstruct the history of isolation and admixture, and discover geographic patterns of genetic partitioning. These analyses demonstrate that persistently unsuitable habitat may have isolated multiple populations distributed across montane habitat islands in the Itombwe Massif and Albertine Rift to the west as well as Mt Elgon and Kenyan Highlands to the east. We detected low genetic diversity in Kenyan Highland populations of both genera, consistent with smaller historical population sizes in this region. We additionally tested predictions that Albertine Rift populations are older and more persistently isolated compared to the Kenyan Highlands. Phylogenetic analyses support greater historical isolation among Albertine Rift populations of both shrews and mice compared to the Kenyan Highlands and suggest that there are genetically isolated populations from both focal genera in the Itombwe Massif, Democratic Republic of Congo. The Albertine Rift ecoregion has the highest mammalian tropical forest species richness per unit area on earth. Our results clearly support accelerating efforts to conserve this diversity.
Historical biogeography, systematics, and integrative taxonomy of the non-Ethiopian speckled pelage brush-furred rats (Lophuromys flavopunctatus group)
Background The speckled-pelage brush-furred rats ( Lophuromys flavopunctatus group) have been difficult to define given conflicting genetic, morphological, and distributional records that combine to obscure meaningful accounts of its taxonomic diversity and evolution. In this study, we inferred the systematics, phylogeography, and evolutionary history of the L. flavopunctatus group using maximum likelihood and Bayesian phylogenetic inference, divergence times, historical biogeographic reconstruction, and morphometric discriminant tests. We compiled comprehensive datasets of three loci (two mitochondrial [mtDNA] and one nuclear) and two morphometric datasets (linear and geometric) from across the known range of the genus Lophuromys . Results The mtDNA phylogeny supported the division of the genus Lophuromys into three primary groups with nearly equidistant pairwise differentiation: one group corresponding to the subgenus Kivumys ( Kivumys group) and two groups corresponding to the subgenus Lophuromys ( L. sikapusi group and L. flavopunctatus group). The L. flavopunctatus group comprised the speckled-pelage brush-furred Lophuromys endemic to Ethiopia (Ethiopian L. flavopunctatus members [ETHFLAVO]) and the non-Ethiopian ones (non-Ethiopian L. flavopunctatus members [NONETHFLAVO]) in deeply nested relationships. There were distinctly geographically structured mtDNA clades among the NONETHFLAVO, which were incongruous with the nuclear tree where several clades were unresolved. The morphometric datasets did not systematically assign samples to meaningful taxonomic units or agree with the mtDNA clades. The divergence dating and ancestral range reconstructions showed the NONETHFLAVO colonized the current ranges over two independent dispersal events out of Ethiopia in the early Pleistocene. Conclusion The phylogenetic associations and divergence times of the L. flavopunctatus group support the hypothesis that paleoclimatic impacts and ecosystem refugia during the Pleistocene impacted the evolutionary radiation of these rodents. The overlap in craniodental variation between distinct mtDNA clades among the NONETHFLAVO suggests unraveling underlying ecomorphological drivers is key to reconciling taxonomically informative morphological characters. The genus Lophuromys requires a taxonomic reassessment based on extensive genomic evidence to elucidate the patterns and impacts of genetic isolation at clade contact zones.
On the taxonomic status and distribution of African species of Otomops (Chiroptera: Molossidae)
Free-tailed bats of the genus are poorly known, and most species are documented from a handful of widely scattered localities. Recently, two allopatric species of were recognized in continental Africa: (Matschie, 1897) in southern, central and western Africa, and the new species Ralph et al., 2015 in the northeast and in Yemen. We collected additional samples of in Kenya and Rwanda where the ranges of these taxa approach one another to clarify their geographic ranges and taxonomic status. Mitochondrial and nuclear intron sequences served to identify and delimit species; we also documented their echolocation call variation and ectoparasite complements. , the southern African species, was documented in northern Kenya in Marsabit National Park. , the northeastern African-Arabian species, was documented in southern Kenya and in a cave in Musanze District, Rwanda. Moreover, individuals of both species were found together at the Musanze cave, establishing them in precise spatial and temporal sympatry. Analyses of mitochondrial and nuclear loci identify no evidence of admixture between these forms, although available samples limit the power of this analysis. Echolocation call differences are also apparent among the three localities we analyzed. Three orders of insects and two families of mites are newly reported as ectoparasites of Our results corroborate species rank for and establish a zone of potential geographic overlap with spanning at least 800 km of latitude. The new records establish the species in sympatry in northern Rwanda and add an additional species to the bat faunas of both Kenya and Rwanda. Future studies are needed to understand roosting requirements and movements, thereby explaining the paucity of known colonies and yielding better estimates of their conservation status. The discovery of mixed roosting associations in Rwanda invites further investigation.
Bowing Fracture With Literature Review
A 5-year-old boy was brought to the emergency department after a fall from a jungle gym. He had persistent pain and swelling of his left forearm.
Polyostotic Fibrous Dysplasia
An 18-year-old man was referred to the authors' institution's thoracic cancer specialists for further consultation after abnormal findings were seen on chest radiograph.An 18-year-old man was referred to the authors' institution's thoracic cancer specialists for further consultation after abnormal findings were seen on chest radiograph.
Genetic variation and relationships among Afrotropical species of Myotis (Chiroptera: Vespertilionidae)
The genus Myotis is nearly cosmopolitan and the second-most speciose genus of mammals, but its Afrotropical members are few and poorly known. We analyzed phylogenetic and phylogeographic relationships of six of the eight known Afrotropical species using Cytb and sequences from four nuclear introns. Using Bayesian and maximum-likelihood approaches to generate single-locus, concatenated, and species trees, we confirmed prior evidence that the clade containing Afrotropical Myotis also contains both Palearctic and Indomalayan members. Additionally, we demonstrate that M. bocagii is sister to the Indian Ocean species M. anjouanensis, that this group is sister to M. tricolor and the Palearctic M. emarginatus, and find evidence suggesting that M. welwitschii is the earliest-diverging Afrotropical species and sister to the remainder. Although M. tricolor and M. welwitschii are both currently regarded as monotypic, both mitochondrial and nuclear data sets document significant, largely concordant geographic structure in each. Evidence for the distinction of two lineages within M. tricolor is particularly strong. On the other hand, geographic structure is lacking in M. bocagii, despite the current recognition of two subspecies in that species. Additional geographic sampling (especially at or near type localities), finer-scale sampling (especially in zones of sympatry), and integrative taxonomic assessments will be needed to better document this radiation and refine its nomenclature.
Acute Fibular Sesamoid Fracture: One Part of the Spectrum of Sesamoid Pathologies
A 35-year-old male athlete presented with acute pain plantar to the hallux metatarsophalangeal joint following jumping to catch a basketball. The authors are from the Department of Radiology (TP, AJS, LML, TCD) and the Department of Orthopaedics (SD), Loyola University Medical Center, Maywood, Illinois. The authors have no relevant financial relationships to disclose. Correspondence should be addressed to: Laurie M. Lomasney, MD, Department of Radiology, Loyola University Medical Center, 2160 S First Ave, Maywood, IL 60153 ( llomasn@lumc.edu). [PUBLICATION ABSTRACT]