Occurrence of the freshwater heteronemertean Apatronemertes albimaculosa (Nemertea: Pilidiophora) in Taiwan

We report the freshwater heteronemertean Apatronemertes albimaculosa Wilfert & Gibson, 1974 for the first time from Taiwan based on specimens collected under stones and rocks on gravelly bottom near the shore of a brook in Nantun District, Taichung City. Species identification was corroborated by mitochondrial cytochrome c oxidase subunit I gene sequences. The species had been reported from aquaria with tropical freshwater plants in Germany, Austria, USA, Spain, and Japan, before it was discovered from wild environment in Panama. Our report represents the second instance of field-caught A. albimaculosa in the world

Molecular phylogenetic position of Minamitalitrus zoltani elucidates a further troglobisation pattern in cave-dwelling terrestrial amphipods (Crustacea: Talitridae)

Talitrids are a highly diverse group of amphipod crustaceans that have colonized various terrestrial habitats. Three genera have successfully adapted to cave habitats on islands in the Pacific and Atlantic Oceans. However, the evolutionary origin of the Pacific troglobitic talitrids has remained unknown. We estimate the phylogenetic position of the troglobitic Minamitalitrus zoltani, which inhabits limestone caves on Minamidaito Island in the Northwestern Pacific, on the basis of the traditional multi-locus dataset. For the analyzed talitrids, we also reconstruct ancestral states of the maxilliped palp and male gnathopod 2. Our results indicate that Minamitalitrus zoltani is sister to the epigean Nipponorchestia curvatus with a deep divergence. Nipponorchestia curvatus inhabits coastal habitats in Japan, but is not indigenous to Minamidaito Island. A previous study estimated that the Atlantic troglobitic species had invaded subterranean habitats multiple times, but we provide new insight into the troglobisation history in talitrids. We also recover secondary shifts of character states of the maxilliped palp and male gnathopod 2 within the lineage composed of Minamitalitrus and its phylogenetically close genera. Our findings highlight the need for the genus-level reclassification of these genera; we split Nipponorchestia into two genera, establishing a new genus for Nipponorchestia nudiramus

A shallow physics-informed neural network for solving partial differential equations on surfaces

In this paper, we introduce a shallow (one-hidden-layer) physics-informed neural network for solving partial differential equations on static and evolving surfaces. For the static surface case, with the aid of level set function, the surface normal and mean curvature used in the surface differential expressions can be computed easily. So instead of imposing the normal extension constraints used in literature, we write the surface differential operators in the form of traditional Cartesian differential operators and use them in the loss function directly. We perform a series of performance study for the present methodology by solving Laplace-Beltrami equation and surface diffusion equation on complex static surfaces. With just a moderate number of neurons used in the hidden layer, we are able to attain satisfactory prediction results. Then we extend the present methodology to solve the advection-diffusion equation on an evolving surface with given velocity. To track the surface, we additionally introduce a prescribed hidden layer to enforce the topological structure of the surface and use the network to learn the homeomorphism between the surface and the prescribed topology. The proposed network structure is designed to track the surface and solve the equation simultaneously. Again, the numerical results show comparable accuracy as the static cases. As an application, we simulate the surfactant transport on the droplet surface under shear flow and obtain some physically plausible results

Association analysis of monoamine oxidase A gene and bipolar affective disorder in Han Chinese

<p>Abstract</p> <p>Background</p> <p>Monoamine oxidase A (MAOA) is a mitochondrial enzyme involved in degrading several different biological amines, including serotonin. Although several pieces of evidence suggested that MAOA is important in the etiology of bipolar affective disorder (BPD), associations for markers of the MAOA gene with BPD were not conclusive and the association has not been investigated in Taiwanese population. This study was designed to illustrate the role of MAOA in the etiology of BPD in Han Chinese.</p> <p>Methods</p> <p>Two markers, a dinucleotide polymorphism in exon 2 and a functional uVNTR on the promoter of the <it>MAOA </it>gene, were used to study the genetic association in 108 unrelated patients with BPD and 103 healthy controls. Allelic distributions of two polymorphisms were analyzed and, caused the MAOA located at X chromosome, haplotype association was performed using haplotype unambiguously assigned in male participants.</p> <p>Results</p> <p>While no difference in allelic distributions of two MAOA polymorphisms was found, the risk haplotype 114S was associated with BPD in male patients (<it>P </it>= 0.03). The significance, however, was not found in female patients with 114S haplotype.</p> <p>Conclusion</p> <p>Results from this study suggest that MAOA may have a gender-specific and small effect on the etiology of BPD in Taiwan. Due to the limited sample size, results from this study need to be confirmed in replicates.</p

Quantification and recognition of parkinsonian gait from monocular video imaging using kernel-based principal component analysis

<p>Abstract</p> <p>Background</p> <p>The computer-aided identification of specific gait patterns is an important issue in the assessment of Parkinson's disease (PD). In this study, a computer vision-based gait analysis approach is developed to assist the clinical assessments of PD with kernel-based principal component analysis (KPCA).</p> <p>Method</p> <p>Twelve PD patients and twelve healthy adults with no neurological history or motor disorders within the past six months were recruited and separated according to their "Non-PD", "Drug-On", and "Drug-Off" states. The participants were asked to wear light-colored clothing and perform three walking trials through a corridor decorated with a navy curtain at their natural pace. The participants' gait performance during the steady-state walking period was captured by a digital camera for gait analysis. The collected walking image frames were then transformed into binary silhouettes for noise reduction and compression. Using the developed KPCA-based method, the features within the binary silhouettes can be extracted to quantitatively determine the gait cycle time, stride length, walking velocity, and cadence.</p> <p>Results and Discussion</p> <p>The KPCA-based method uses a feature-extraction approach, which was verified to be more effective than traditional image area and principal component analysis (PCA) approaches in classifying "Non-PD" controls and "Drug-Off/On" PD patients. Encouragingly, this method has a high accuracy rate, 80.51%, for recognizing different gaits. Quantitative gait parameters are obtained, and the power spectrums of the patients' gaits are analyzed. We show that that the slow and irregular actions of PD patients during walking tend to transfer some of the power from the main lobe frequency to a lower frequency band. Our results indicate the feasibility of using gait performance to evaluate the motor function of patients with PD.</p> <p>Conclusion</p> <p>This KPCA-based method requires only a digital camera and a decorated corridor setup. The ease of use and installation of the current method provides clinicians and researchers a low cost solution to monitor the progression of and the treatment to PD. In summary, the proposed method provides an alternative to perform gait analysis for patients with PD.</p

Aharonov-Bohm interference in topological insulator nanoribbons

Topological insulators represent novel phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport measurements. Recently, Bi2Se3 and related materials have been proposed as three-dimensional topological insulators with a single Dirac cone on the surface and verified by angle-resolved photoemission spectroscopy experiments. Here, we show unambiguous transport evidence of topological surface states through periodic quantum interference effects in layered single-crystalline Bi2Se3 nanoribbons. Pronounced Aharonov-Bohm oscillations in the magnetoresistance clearly demonstrate the coverage of two-dimensional electrons on the entire surface, as expected from the topological nature of the surface states. The dominance of the primary h/e oscillation and its temperature dependence demonstrate the robustness of these electronic states. Our results suggest that topological insulator nanoribbons afford novel promising materials for future spintronic devices at room temperature.Comment: 5 pages, 4 figures, RevTex forma

High yield expression in a recombinant E. coli of a codon optimized chicken anemia virus capsid protein VP1 useful for vaccine development

<p>Abstract</p> <p>Background</p> <p>Chicken anemia virus (CAV), the causative agent chicken anemia, is the only member of the genus <it>Gyrovirus </it>of the <it>Circoviridae </it>family. CAV is an immune suppressive virus and causes anemia, lymph organ atrophy and immunodeficiency. The production and biochemical characterization of VP1 protein and its use in a subunit vaccine or as part of a diagnostic kit would be useful to CAV infection prevention.</p> <p>Results</p> <p>Significantly increased expression of the recombinant full-length VP1 capsid protein from chicken anemia virus was demonstrated using an <it>E. coli </it>expression system. The VP1 gene was cloned into various different expression vectors and then these were expressed in a number of different <it>E. coli </it>strains. The expression of CAV VP1 in <it>E. coli </it>was significantly increased when VP1 was fused with GST protein rather than a His-tag. By optimizing the various rare amino acid codons within the N-terminus of the VP1 protein, the expression level of the VP1 protein in <it>E. coli </it>BL21(DE3)-pLysS was further increased significantly. The highest protein expression level obtained was 17.5 g/L per liter of bacterial culture after induction with 0.1 mM IPTG for 2 h. After purification by GST affinity chromatography, the purified full-length VP1 protein produced in this way was demonstrated to have good antigenicity and was able to be recognized by CAV-positive chicken serum in an ELISA assay.</p> <p>Conclusions</p> <p>Purified recombinant VP1 protein with the gene's codons optimized in the N-terminal region has potential as chimeric protein that, when expressed in <it>E. coli</it>, may be useful in the future for the development of subunit vaccines and diagnostic tests.</p

Tyrannobdella rex N. Gen. N. Sp. and the Evolutionary Origins of Mucosal Leech Infestations

BACKGROUND: Leeches have gained a fearsome reputation by feeding externally on blood, often from human hosts. Orificial hirudiniasis is a condition in which a leech enters a body orifice, most often the nasopharyngeal region, but there are many cases of leeches infesting the eyes, urethra, vagina, or rectum. Several leech species particularly in Africa and Asia are well-known for their propensity to afflict humans. Because there has not previously been any data suggesting a close relationship for such geographically disparate species, this unnerving tendency to be invasive has been regarded only as a loathsome oddity and not a unifying character for a group of related organisms. PRINCIPAL FINDINGS: A new genus and species of leech from Perú was found feeding from the nasopharynx of humans. Unlike any other leech previously described, this new taxon has but a single jaw with very large teeth. Phylogenetic analyses of nuclear and mitochondrial genes using parsimony and Bayesian inference demonstrate that the new species belongs among a larger, global clade of leeches, all of which feed from the mucosal surfaces of mammals. CONCLUSIONS: This new species, found feeding from the upper respiratory tract of humans in Perú, clarifies an expansion of the family Praobdellidae to include the new species Tyrannobdella rex n. gen. n. sp., along with others in the genera Dinobdella, Myxobdella, Praobdella and Pintobdella. Moreover, the results clarify a single evolutionary origin of a group of leeches that specializes on mucous membranes, thus, posing a distinct threat to human health