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1.
Mol Phylogenet Evol ; 193: 107999, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38160993

ABSTRACT

Traditional classification of many animals, including birds, has been highly dependent on external morphological characters like plumage coloration. However, both bioacoustics and genetic or genomic data have revolutionized our understanding of the relationships of certain lineages and led to sweeping taxonomic re-organizations. In this study, we present a case of erroneous delimitation of genus boundaries in the species-rich flycatcher subfamily Niltavinae. Genera within this subfamily have historically been delineated based on blue versus brown male body plumage until recent studies based on a few mitochondrial and nuclear loci unearthed several cases of generic misclassification. Here we use extensive bioacoustic data from 43 species and genomic data from 28 species for a fundamental reclassification of species in the Niltavinae. Our study reveals that song is an important trait to classify these birds even at the genus level, whereas plumage traits exhibit ample convergence and have led to numerous historic misattributions. Our taxonomic re-organization leads to new biogeographic limits of major genera, such that the genus Cyornis now only extends as far east as the islands of Sulawesi, Sula, and Banggai, whereas Eumyias is redefined to extend far beyond Wallace's Line to the islands of Seram and Timor. Our conclusions advise against an over-reliance on morphological traits and underscore the importance of integrative datasets.


Subject(s)
Passeriformes , Songbirds , Animals , Male , Songbirds/genetics , Phylogeny , Passeriformes/genetics , Genomics , Genome
2.
Curr Biol ; 32(23): R1302-R1303, 2022 12 05.
Article in English | MEDLINE | ID: mdl-36473437

ABSTRACT

Sugars are an important class of nutrients found in the flowers and fruits of angiosperms (flowering plants). Although T1R2-T1R3 has been identified as the mammalian sweet receptor, some birds rely on a repurposed T1R1-T1R3 savory receptor to sense sugars. Moreover, as the radiation of flowering plants occurred later than the last common ancestor of amniotes, sugar may not have been an important diet item for amniotes early in evolution, raising the question of whether T1R2-T1R3 is a universal sugar sensor or only a mammalian innovation. Here, using brief-access behavioral tests and functional characterization of taste receptors, we demonstrate that the nectar-taking Madagascar giant day gecko (Phelsuma grandis) can sense sugars through the T1R2-T1R3 receptor. These results reveal the existence of T1R2-based sweet taste in a non-avian reptile, which has important implications for our understanding of the evolutionary history of sugar detection in amniotes.


Subject(s)
Lizards , Animals , Sugars , Madagascar , Mammals
3.
Asian Spine J ; 15(1): 23-31, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32160727

ABSTRACT

STUDY DESIGN: Prospective radiographic comparative study. PURPOSE: To compare and understand the load-bearing properties of each functional spinal unit (FSU) using three commonly assumed, physiological, spinal postures, namely, the flexed (slump sitting), erect (standing) and extended (backward bending) postures. OVERVIEW OF LITERATURE: Sagittal spinal alignment is posture-dependent and influences the load-bearing properties of the spine. The routine placement of intervertebral cages "as anterior as possible" to correct deformity may compromise the load-bearing capabilities of the spine, leading to complications. METHODS: We recruited young patients with nonspecific low back pain for <3 months, who were otherwise healthy. Each patient had EOS images taken in the flexed, erect and extended positions, in random order, as well as magnetic resonance imaging to assess for disk degeneration. Angular and disk height measurements were performed and compared in all three postures using paired t-tests. Changes in disk height relative to the erect posture were caclulated to determine the alignment-specific load-bearing area of each FSU. RESULTS: Eighty-three patients (415 lumbar intervertebral disks) were studied. Significant alignment changes were found between all three postures at L1/2, and only between erect and flexion at the other FSUs. Disk height measurements showed that the neutral axis of the spine, marked by zones where disk heights did not change, varied between postures and was level specific. The load-bearing areas were also found to be more anterior in flexion and more posterior in extension, with the erect spine resembling the extended spine to a greater extent. CONCLUSIONS: Load-bearing areas of the lumbar spine are sagittal alignment-specific and level-specific. This may imply that, depending on the surgical realignment strategy, attention should be paid not just to placing an intervertebral cage "as anterior as possible" for generating lordosis, but also on optimizing load-bearing in the lumbar spine.

4.
Mol Ecol ; 29(14): 2692-2706, 2020 07.
Article in English | MEDLINE | ID: mdl-32542783

ABSTRACT

Quaternary climate oscillations are a well-known driver of animal diversification, but their effects are most well studied in areas where glaciations lead to habitat fragmentation. In large areas of the planet, however, glaciations have had the opposite effect, but here their impacts are much less well understood. This is especially true in Southeast Asia, where cyclical changes in land distribution have generated enormous land expansions during glacial periods. In this study, we selected a panel of five songbird species complexes covering a range of ecological specificities to investigate the effects Quaternary land bridges have had on the connectivity of Southeast Asian forest biota. Specifically, we combined morphological and bioacoustic analysis with an arsenal of population genomic and modelling approaches applied to thousands of genome-wide DNA markers across a total of more than 100 individuals. Our analyses show that species dependent on forest understorey exhibit deep differentiation between Borneo and western Sundaland, with no evidence of gene flow during the land bridges accompanying the last 1-2 ice ages. In contrast, dispersive canopy species and habitat generalists have experienced more recent gene flow. Our results argue that there remains much cryptic species-level diversity to be discovered in Southeast Asia even in well-known animal groups such as birds, especially in nondispersive forest understorey inhabitants. We also demonstrate that Quaternary land bridges have not been equally suitable conduits of gene flow for all species complexes and that life history is a major factor in predicting relative population divergence time across Quaternary climate fluctuations.


Subject(s)
Evolution, Molecular , Gene Flow , Genetics, Population , Songbirds , Animals , Asia, Southeastern , Borneo , Ecosystem , Phylogeny , Songbirds/classification , Songbirds/genetics
5.
Science ; 367(6474): 167-170, 2020 01 10.
Article in English | MEDLINE | ID: mdl-31919216

ABSTRACT

Birds are the best-known animal class, with only about five or six new species descriptions per year since 1999. Integrating genomic and phenotypic research with arduous fieldwork in remote regions, we describe five new songbird species and five new subspecies from a small area near Sulawesi, Indonesia, all collected in a single 6-week expedition. Two factors contributed to the description of this large number of species from such a small geographic area: (i) Knowledge of Quaternary Period land connections helped pinpoint isolated islands likely to harbor substantial endemism and (ii) studying accounts of historic collectors such as Alfred Wallace facilitated the identification of undercollected islands. Our findings suggest that humans' understanding of biogeographically complex regions such as Wallacea remains incomplete.


Subject(s)
Biodiversity , Songbirds/classification , Animals , Extinction, Biological , Indonesia , Islands , Phylogeography
6.
Dis Mon ; 65(12): 100851, 2019 Dec.
Article in English | MEDLINE | ID: mdl-30837080

ABSTRACT

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disorder of the colon that causes continuous mucosal inflammation extending from the rectum to the more proximal colon, with variable extents. UC is characterized by a relapsing and remitting course. UC was first described by Samuel Wilks in 1859 and it is more common than Crohn's disease worldwide. The overall incidence and prevalence of UC is reported to be 1.2-20.3 and 7.6-245 cases per 100,000 persons/year respectively. UC has a bimodal age distribution with an incidence peak in the 2nd or 3rd decades and followed by second peak between 50 and 80 years of age. The key risk factors for UC include genetics, environmental factors, autoimmunity and gut microbiota. The classic presentation of UC include bloody diarrhea with or without mucus, rectal urgency, tenesmus, and variable degrees of abdominal pain that is often relieved by defecation. UC is diagnosed based on the combination of clinical presentation, endoscopic findings, histology, and the absence of alternative diagnoses. In addition to confirming the diagnosis of UC, it is also important to define the extent and severity of inflammation, which aids in the selection of appropriate treatment and for predicting the patient's prognosis. Ileocolonoscopy with biopsy is the only way to make a definitive diagnosis of UC. A pathognomonic finding of UC is the presence of continuous colonic inflammation characterized by erythema, loss of normal vascular pattern, granularity, erosions, friability, bleeding, and ulcerations, with distinct demarcation between inflamed and non-inflamed bowel. Histopathology is the definitive tool in diagnosing UC, assessing the disease severity and identifying intraepithelial neoplasia (dysplasia) or cancer. The classical histological changes in UC include decreased crypt density, crypt architectural distortion, irregular mucosal surface and heavy diffuse transmucosal inflammation, in the absence of genuine granulomas. Abdominal computed tomographic (CT) scanning is the preferred initial radiographic imaging study in UC patients with acute abdominal symptoms. The hallmark CT finding of UC is mural thickening with a mean wall thickness of 8 mm, as opposed to a 2-3 mm mean wall thickness of the normal colon. The Mayo scoring system is a commonly used index to assess disease severity and monitor patients during therapy. The goals of treatment in UC are three fold-improve quality of life, achieve steroid free remission and minimize the risk of cancer. The choice of treatment depends on disease extent, severity and the course of the disease. For proctitis, topical 5-aminosalicylic acid (5-ASA) drugs are used as the first line agents. UC patients with more extensive or severe disease should be treated with a combination of oral and topical 5-ASA drugs +/- corticosteroids to induce remission. Patients with severe UC need to be hospitalized for treatment. The options in these patients include intravenous steroids and if refractory, calcineurin inhibitors (cyclosporine, tacrolimus) or tumor necrosis factor-α antibodies (infliximab) are utilized. Once remission is induced, patients are then continued on appropriate medications to maintain remission. Indications for emergency surgery include refractory toxic megacolon, colonic perforation, or severe colorectal bleeding.


Subject(s)
Colitis, Ulcerative/therapy , Intestinal Mucosa/pathology , Anti-Inflammatory Agents/therapeutic use , Colitis, Ulcerative/complications , Colitis, Ulcerative/diagnosis , Colitis, Ulcerative/pathology , Colon/pathology , Humans , Inflammation/diagnosis , Inflammation/therapy , Quality of Life , Rectum/pathology , Severity of Illness Index
7.
Sci Rep ; 8(1): 15646, 2018 10 23.
Article in English | MEDLINE | ID: mdl-30353148

ABSTRACT

Leaf warblers (Aves; Phylloscopidae) are a diverse clade of insectivorous, canopy-dwelling songbirds widespread across the Old World. The taxonomy of Australasian leaf warblers is particularly complex, with multiple species-level divergences between island taxa in the region requiring further scrutiny. We use a combination of morphology, bioacoustics, and analysis of thousands of genome-wide markers to investigate and describe a new species of Phylloscopus leaf warbler from the island of Rote in the Lesser Sundas, Indonesia. We show that this new Rote Leaf Warbler is morphologically and genomically highly distinct from its congenerics, but do not find vocal differentiation between different island taxa. We discuss the behaviour and ecology of this highly distinctive new species, and make recommendations about its conservation status. We believe this constitutes the first description of a novel bird species that is partly based on insights from massive amounts of genome-wide DNA markers.


Subject(s)
Genomics , Songbirds/anatomy & histology , Songbirds/genetics , Acoustics , Animals , Cytochromes b/genetics , Geography , Indonesia , Islands , Likelihood Functions , Mitochondria/genetics , Phylogeny , Principal Component Analysis , Sound Spectrography , Species Specificity
8.
Zootaxa ; 4358(2): 365-374, 2017 Nov 29.
Article in English | MEDLINE | ID: mdl-29245475

ABSTRACT

The taxonomic status of the geographically isolated population of Short-toed Snake-eagle Circaetus gallicus on the Lesser Sundas (=Nusa Tenggara) has been controversial. In the past they have been regarded as either a migrant population or a recently arrived resident population. Here we obtained DNA sequences from the mitochondrial cytochrome-b gene and combined genetic data with assessments of published and novel morphological data to clarify the taxonomic status of the Lesser Sundas population of C. gallicus. The cytochrome-b distance between the Lesser Sundas and Palearctic populations of C. gallicus is consistent with subspecific differentiation, indicating a possible divergence during one of the most recent Pleistocene glaciations. Although some of the morphological distinctions show overlap, the new subspecies can generally be diagnosed from nominate C. gallicus gallicus by being smaller and paler, and exhibiting less spotting and barring. Unlike nominate populations from mainland Eurasia, the new subspecies seems to lack pronounced sexual dimorphism. We here describe this new subspecies to science and discuss its biology and conservation status.


Subject(s)
Eagles , Animals , DNA, Mitochondrial , Genes, Mitochondrial , Phylogeny
10.
Mol Phylogenet Evol ; 114: 353-366, 2017 09.
Article in English | MEDLINE | ID: mdl-28501612

ABSTRACT

The role of Pleistocene Ice Age in tropical diversification is poorly understood, especially in archipelagos, in which glaciation-induced sea level fluctuations may lead to complicated changes in land distribution. To assess how Pleistocene land bridges may have facilitated gene flow in tropical archipelagos, we investigated patterns of diversification in the rarely-collected rusty-bellied fantail Rhipidura teysmanni (Passeriformes: Rhipiduridae) complex from Wallacea using a combination of bioacoustic traits and whole-genome sequencing methods (dd-RADSeq). We report a biogeographic leapfrog pattern in the vocalizations of these birds, and uncover deep genomic divergence among island populations despite the presence of intermittent land connections between some. We demonstrate how rare instances of genetic introgression have affected the evolution of this species complex, and document the presence of double introgressive mitochondrial sweeps, highlighting the dangers of using only mitochondrial DNA in evolutionary research. By applying different tree inference approaches, we demonstrate how concatenation methods can give inaccurate results when investigating divergence in closely-related taxa. Our study highlights high levels of cryptic avian diversity in poorly-explored Wallacea, elucidates complex patterns of Pleistocene climate-mediated diversification in an elusive montane songbird, and suggests that Pleistocene land bridges may have accounted for limited connectivity among montane Wallacean biota.


Subject(s)
Songbirds/classification , Animals , Bayes Theorem , Climate Change , DNA/chemistry , DNA/isolation & purification , DNA/metabolism , Genetic Variation , NADH Dehydrogenase/classification , NADH Dehydrogenase/genetics , Phylogeny , Polymorphism, Single Nucleotide , Principal Component Analysis , Sequence Analysis, DNA , Songbirds/genetics
11.
Semin Cell Dev Biol ; 61: 99-106, 2017 01.
Article in English | MEDLINE | ID: mdl-27381343

ABSTRACT

The genus Peromyscus has been used as a model system for understanding maternal behavior because of the diversity of reproductive strategies within this genus. This review will describe the ecological factors that determine litter size and litter quality in polygynous species such as Peromyscus leucopus and Peromyscus maniculatus. We will also outline the physiological and social factors regulating maternal care in Peromyscus californicus, a monogamous and biparental species. Because biparental care is relatively rare in mammals, most research in P. californicus has focused on understanding the biology of paternal care while less research has focused on understanding maternal care. As a result, the social, sensory, and hormonal cues used to coordinate parental care between male and female P. californicus have been relatively well-studied. However, less is known about the physiology of maternal care in P. californicus and in other Peromyscus species. The diversity of the genus Peromyscus provides the potential for future research to continue to examine how variation in social systems has shaped the mechanisms that underlie maternal care.


Subject(s)
Maternal Behavior/physiology , Models, Animal , Peromyscus/physiology , Animals , Ecosystem , Endocrine System/metabolism , Female
12.
Mol Phylogenet Evol ; 102: 97-103, 2016 09.
Article in English | MEDLINE | ID: mdl-27233436

ABSTRACT

Species identification has traditionally relied on morphology. However, morphological conservatism can lead to a high incidence of cryptic species, as characters other than morphological ones can be biologically important. In birds, the combined application of bioacoustic and molecular criteria has led to an avalanche of cryptic species discoveries over the last two decades in which findings of deep vocal differentiation have usually been corroborated by molecular data or vice versa. In this study, we use genome-wide DNA data to uncover an unusual case of cryptic speciation in two species within the South-east Asian Streak-eared Bulbul Pycnonotus blanfordi complex, in which both morphology and vocalizations have remained extremely similar. Despite a considerable pre-Pleistocene divergence of these two bulbul species, bioacoustic analysis failed to uncover differences in their main vocalization, but examination of live birds revealed important differences in eye color that had been overlooked in museum material. Our study demonstrates that genome-wide DNA data can be helpful in the detection of cryptic speciation, especially in species that have evolved limited morphological and behavioral differences.


Subject(s)
Genome , Passeriformes/anatomy & histology , Passeriformes/genetics , Phylogeny , Vocalization, Animal , Acoustics , Animals , DNA/genetics , Geography , Pigmentation , Principal Component Analysis , Sequence Analysis, DNA
13.
Nat Commun ; 7: 11069, 2016 Mar 30.
Article in English | MEDLINE | ID: mdl-27026263

ABSTRACT

The newt, a urodele amphibian, is able to repeatedly regenerate its limbs throughout its lifespan, whereas other amphibians deteriorate or lose their ability to regenerate limbs after metamorphosis. It remains to be determined whether such an exceptional ability of the newt is either attributed to a strategy, which controls regeneration in larvae, or on a novel one invented by the newt after metamorphosis. Here we report that the newt switches the cellular mechanism for limb regeneration from a stem/progenitor-based mechanism (larval mode) to a dedifferentiation-based one (adult mode) as it transits beyond metamorphosis. We demonstrate that larval newts use stem/progenitor cells such as satellite cells for new muscle in a regenerated limb, whereas metamorphosed newts recruit muscle fibre cells in the stump for the same purpose. We conclude that the newt has evolved novel strategies to secure its regenerative ability of the limbs after metamorphosis.


Subject(s)
Cell Dedifferentiation , Extremities/physiology , Muscles/physiology , Regeneration/physiology , Salamandridae/physiology , Stem Cells/cytology , Animals , Cell Lineage , Cell Tracking , Extremities/transplantation , Female , Larva/physiology , Luminescent Proteins/metabolism , Male , Metamorphosis, Biological , Muscle Fibers, Skeletal/cytology , Red Fluorescent Protein
14.
Am Surg ; 81(7): 714-9, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26140893

ABSTRACT

Ventral hernia recurrence rates have improved with advancements in technique. Open and laparoscopic fascial component separation techniques improve recurrence rates by allowing a tension free closure. This study examines laparoscopic component separation (LCS) and open component separation (OCS) techniques in the repair of complex ventral hernias and compares factors affecting patient outcomes. A retrospective chart review of patients who underwent ventral hernia repair with LCS and OCS was conducted between 2009 and 2013. Patient characteristics and outcomes were documented. Hernia recurrence was determined using physical exam and computed tomography if physical exam was equivocal. Univariate and multivariate analyses were performed. Ten patients underwent LCS and 38 underwent OCS. The rate of wound infection in the LCS group was 20 per cent versus 50 per cent in the OCS group. The overall rate of recurrence after LCS was 20 per cent, and 26 per cent in the OCS group. For body mass index > 30, the recurrence rate was 20 per cent in the LCS group and 29 per cent (P = 0.5) in the open group. The use of LCS demonstrates a trend in the reduction of hernia recurrence and wound infection overall and in patients with body mass index > 30 compared with OCS.


Subject(s)
Fasciotomy , Hernia, Ventral/surgery , Body Mass Index , Comorbidity , Hernia, Ventral/epidemiology , Humans , Laparoscopy , Logistic Models , Middle Aged , Multivariate Analysis , Recurrence , Retrospective Studies , Surgical Wound Infection/epidemiology , Treatment Outcome
15.
Int J Surg Case Rep ; 13: 99-102, 2015.
Article in English | MEDLINE | ID: mdl-26188978

ABSTRACT

INTRODUCTION: Severe traumatic liver hemorrhage quickly leads to exsanguination. Perihepatic packing is frequently used in damage control surgery. This method can be unsuccessful and accompanied by complications. Vicryl mesh wraps have been described in the treatment of liver hemorrhage. In this report, we describe an enhanced technique of hepatic wrapping in a case of hepatic bleeding after liver biopsy in a coagulopathic patient. The technique is called the hepatic "BOLSA" (Bag on Liver Supporting Anti-Hemorrhage). PRESENTATION OF CASE: A 59 year old male presented in the recovery room after liver biopsy of a mass, followed by angio-embolization of the hepatic mass 9h earlier. The patient was acidotic, coagulopathic, and demonstrated intra-abdominal hypertension. Computed tomography demonstrated perihepatic fluid. The patient continued hemorrhaging despite attempts to correct coagulopathy by transfusion. Multiple operating room visits were required where a combination of packing and hemostatic agents could not stop hepatic venous parenchymal hemorrhage. Mesh wrap consisting of Vicryl and PDS suture were used to create the "BOLSA" to achieve hemostasis. DISCUSSION: Perihepatic packing compromises pulmonary excursion, elevates intra-abdominal pressure, is a risk factor for sepsis, and requires an additional trip to the operating room for removal. The use of Vicryl mesh wrap obviates these complications. Previously described mesh wraps require anchoring. The self-supporting structure of the BOLSA simplifies construction and application. CONCLUSION: The BOLSA is an effective tool in treatment of severe liver hemorrhage in coagulopathic patients. It is the modern simplification of hepatic wrapping and the solution to the side effects of perihepatic packing.

17.
ACS Nano ; 5(2): 1067-72, 2011 Feb 22.
Article in English | MEDLINE | ID: mdl-21271737

ABSTRACT

Nanostructured piezoelectric and ferroelectric thin films are being increasingly used in sensing and actuating microdevices. In this work, we report the experimental discovery of localized electric field enhancement in nanocolumnar piezoelectric thin films and its significant impact on piezoresponse. The magnitude of electric field enhancement is associated with nonflat surface morphologies and is in agreement with theoretical and finite element models. The influence of this surface morphology induced enhancement on piezoresponse is demonstrated using phase field simulations, which also illustrates surface morphology induced strain enhancement. The observed enhancement can be effectively harnessed to improve the sensitivity of related piezoelectric thin film applications.


Subject(s)
Electricity , Nanostructures/chemistry , Finite Element Analysis , Surface Properties
18.
Nanotechnology ; 20(44): 445709, 2009 Nov 04.
Article in English | MEDLINE | ID: mdl-19809119

ABSTRACT

The effects of surface morphology on polarization switching in thin ferroelectric films are investigated using a real-space, time-dependent Ginzburg-Landau model that incorporates electrostatic interactions. We consider a two-dimensional uni-axial ferroelectric film with a thickness that varies sinusoidally. Polarization switching, starting from a single domain remnant state, is simulated for several surface modulation amplitudes and wavelengths. We demonstrate that surface heterogeneities produce inhomogeneities in the electric field within the film. These inhomogeneities become preferential sites for easy nucleation of reverse domains. This has a profound effect on the external field necessary to switch the polarization. Increasing the surface undulation amplitude significantly reduces the coercive field compared to the ideal flat film, even for very small amplitude modulations in the thickness. Although surface roughness decreases the field required to form reverse domains, it also hinders subsequent domain wall migration. In fact, for very high amplitude and small wavelength surface morphologies, complete switching to a single domain state becomes impossible. This is because the domain walls become trapped near the peaks in the modulated surface. The technological implications of the present results for utilization of surface roughness and for surface morphology design are discussed.

19.
J Phys Chem B ; 113(17): 5897-904, 2009 Apr 30.
Article in English | MEDLINE | ID: mdl-19351121

ABSTRACT

The line width dependence of zero-phonon lines and phonon sidebands on temperature, bath dissipation, and electron-phonon coupling is studied for an underdamped Brownian oscillator model with an Ohmic dissipative bath. Factors determining the line widths vary from the zero-phonon lines to the phonon sidebands. The control-parameter space of line broadening has been mapped out, revealing that the line widths of the zero-phonon lines and phonon sidebands are linearly dependent on both the temperature and the Huang-Rhys factor. It is also found that the dependence of the line widths on the bath damping factor is linear for the zero-phonon lines and quadratic for the phonon sidebands.

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