19672 research outputs found
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A Case of Persistent Urogenital Sinus: Pitfalls and challenges in diagnosis
Get PDFPersistent urogenital sinus (PUGS) is a rare anomaly whereby the urinary and genital tracts fail to separate during embryonic development. We report a three-year-old female child who was referred to the Sabah Women & Children Hospital, Sabah, Malaysia, in 2016 with a pelvic mass. She had been born prematurely at 36 gestational weeks via spontaneous vaginal delivery in 2013 and initially misdiagnosed with neurogenic bladder dysfunction. The external genitalia appeared normal and an initial sonogram and repeat micturating cystourethrograms did not indicate any urogenital anomalies. She therefore underwent clean intermittent catheterisation. Three years later, the diagnosis was corrected following the investigation of a persistent cystic mass posterior to the bladder. At this time, a clinical examination of the perineum showed a single opening into the introitus. Magnetic resonance imaging of the pelvis revealed gross hydrocolpos and a genitogram confirmed a diagnosis of PUGS, for which the patient underwent surgical separation of the urinary and genital tracts
A review on modeling and control of olefin polymerization in fluidized-bed reactors
No full textThis is a detailed review on olefin polymerization models, and the most recent process control approaches used to control these nonlinear systems are presented. Great focus has been given to the various approaches of fluidized-bed reactor (FBR) modeling. Currently, there has yet to be a single model that blends these modeling aspects together into one single formulation. In this article, the classification of models works by looking at their assumption in considering the phases inside the system. Researchers have been unraveling vast information to narrate in detail the relations between various variables that can be found in FBRs. Although it is not difficult to understand about the basics of modeling polymer properties, a gap exists for future researchers to justify in detail the phenomena and reduce the gap between model predictions and the actual data. The various controlling approaches to control these FBRs have also been reviewed and categorized depending on the method they used to control significant parameters of this nonlinear system. The progress that can be expected in this field leads to the creation of more efficient reactors and minimizing waste
Inverse Identification of Composite Material Properties by using a Two-Stage Fourier Method
No full textThis study presents a feasible identification method for composite materials that adopts the combined use of the Fourier method, a weighted least squares method and the mode shape error function. The deflection shape function of the plate structure is defined in terms of 2D Fourier cosine series which is supplemented with several one-dimensional additional terms to accommodate general boundary conditions. The derivatives of mode shape with respect to the flexural rigidity are derived and computed from the model’s displacement function. A difference exists in the means of obtaining the mode shape derivatives between the present approach and the commonly used finite element model updating method. This research proposes a two-stage identification approach, in which the natural frequency error function is utilised in stage 1. In stage 2, the mode shape error function is used, which is proven vital in improving the accuracy of the in-plane shear modulus and Poisson’s ratio by at most 13%
A New Species of the Simulium (Simulium) argentipes Species-Group (Diptera: Simuliidae) From Taiwan, and Its Phylogenetic Relationships With Four Related Species
No full textA new black fly species, Simulium haiduanense Takaoka, Low & Huang (Diptera: Simuliidae), is described on the basis of females, males, pupae, and mature larvae from Taiwan. This new species is placed in the Simulium argentipes species-group of the subgenus Simulium (Diptera: Simuliidae) and is characterized by the yellowish female legs, ovipositor valves rounded apically and with its inner margin concave, claw with a small subbasal tooth, male style without a basal protuberance, pupal gill with eight flaments, corbicular cocoon, and larval abdomen lacking paired protuberances. It represents the first record of the S. argentipes species-group from Taiwan. Taxonomic notes are given to separate this new species from all eight species in the same species-group. The phylogenetic relationships of this new species with four related species are presented
Five new species of the Simulium decuplum subgroup of the Simulium ( Gomphostilbia ) batoense species-group (Diptera: Simuliidae) from Thailand and their phylogenetic relationships
No full textFive new species of black flies, Simulium (Gomphostilbia) chiangraiense, S. (G.) huaikaeoense, S. (G.) khaokhoense, S. (G.) maeklangense, and S. (G.) pamiangense, are described based on adults, pupae and mature larvae from Thailand. These five species are similar to one another and are placed in the S. decuplum subgroup of the S. batoense species-group by having the male fore coxae darkened, ventral plate flat and transverse; pupal gill with 10 short filaments; and larval postgenal cleft deep approaching or reaching the posterior margin of the hypostoma. Simulium (G.) chiangraiense sp. nov. and S. (G.) pamiangense sp. nov. differ from the three other new species by the much longer pupal gill filaments and darkened dorsal surface of abdominal segments 1 and 2. Taxonomic notes are provided to distinguish these five new species from five other related species. The phylogenetic positions of these new species in the S. decuplum subgroup are presented based on the mitochondrial COI gene. Simulium (G.) pamiangense sp. nov. and S. (G.) huaikaeoense sp. nov. are highly similar to each other genetically, showing a sister relationship, though they are clearly different morphologically. On the contrary, S. (G.) khaokhoense sp. nov. is distantly positioned from S. (G.) huaikaeoense nov., though it is almost indistinguishable morphologically from the latter
Cost Effective Network Flow Measurement for Software Defined Networks: A Distributed Controller Scenario
No full textSoftware-defined networking (SDN) has emerged as an evolutionary paradigm in datacenter networks by separating data from control plane and centralizing network decision making. Traffic flow measurement in SDN is relatively lightweight in comparison to the traditional methods. It enables flow measurement system to overcome the issues of traditional measurement systems, such as cost and accuracy by employing a centralized controller. Nevertheless, a full physically centralized controller introduces negative impacts on the network as well as the measurement system (i.e., introducing extra overhead or accuracy issues). However, few efforts have been devoted to measurement techniques in SDN distributed controller architecture, where every controller pulls its corresponding flow statistics, and these statistics are required to expose by only one single expression as if they are collected by one controller. Moreover, the imposed costs of flow measurement in distributed controller architecture are still an issue that remains unsolved. In this paper, we attempt to fill in this gap and present a novel and a practical solution for a cost-effective measurement system in SDN distributed controller deployment. We also propose a synchronization mechanism for aggregating traffic statistics in the multiple controller model. We evaluate our method through extensive emulations in a datacenter topology and present our findings to demonstrate the impact of multiple controllers on overhead and accuracy
Transient Expression of an Immunogenic Envelope Attachment Glycoprotein of Nipah Virus in Nicotiana benthamiana
No full textThe Nipah virus is highly virulent to swine and humans. The envelope attachment glycoprotein (G) of Nipah virus plays a key role in viral entry and induction of neutralizing antibody in mammalian hosts, thus is considered a good candidate for vaccine development. Plant transient expression systems are gaining recognition as a viable alternative for the production of vaccine antigens. In this study, we expressed the Nipah virus G protein heterologously in Nicotiana benthamiana using an agroinfiltration approach. The highest expression of recombinant G protein in N. benthamiana at RNA and protein levels was detected on day 9 post-infiltration. Western blot analysis demonstrated that the purified G protein reacted specifically with rabbit anti-Nipah Virus serum, indicating its potential for vaccine use
Computational prediction of changes in brain metabolic fluxes during Parkinson’s disease from mRNA expression
No full textBackground Parkinson’s disease is a widespread neurodegenerative disorder which affects brain metabolism. Although changes in gene expression during disease are often measured, it is difficult to predict metabolic fluxes from gene expression data. Here we explore the hypothesis that changes in gene expression for enzymes tend to parallel flux changes in biochemical reaction pathways in the brain metabolic network. This hypothesis is the basis of a computational method to predict metabolic flux changes from post-mortem gene expression measurements in Parkinson’s disease (PD) brain. Results We use a network model of central metabolism and optimize the correspondence between relative changes in fluxes and in gene expression. To this end we apply the Least-squares with Equalities and Inequalities algorithm integrated with Flux Balance Analysis (Lsei-FBA). We predict for PD (1) decreases in glycolytic rate and oxygen consumption and an increase in lactate production in brain cortex that correspond with measurements (2) relative flux decreases in ATP synthesis, in the malate-aspartate shuttle and midway in the TCA cycle that are substantially larger than relative changes in glucose uptake in the substantia nigra, dopaminergic neurons and most other brain regions (3) shifts in redox shuttles between cytosol and mitochondria (4) in contrast to Alzheimer’s disease: little activation of the gamma-aminobutyric acid shunt pathway in compensation for decreased alpha-ketoglutarate dehydrogenase activity (5) in the globus pallidus internus, metabolic fluxes are increased, reflecting increased functional activity. Conclusion Our method predicts metabolic changes from gene expression data that correspond in direction and order of magnitude with presently available experimental observations during Parkinson’s disease, indicating that the hypothesis may be useful for some biochemical pathways. Lsei-FBA generates predictions of flux distributions in neurons and small brain regions for which accurate metabolic flux measurements are not yet possible
Pahangine A and B, two new oxetane containing neolignans from the barks of Beilschmiedia glabra Kosterm (Lauraceae)
No full textPhytochemical investigation on the barks of Beilschmiedia glabra Kosterm led to the isolation of two new oxetane containing neolignans, Pahangine A (1) and Pahangine B (2) together with eight known compounds. The structures of isolated compounds were elucidated by extensive spectroscopic analysis including 1D and 2D NMR (1H–1H COSY, HSQC, and HMBC), DEPT-Q NMR, and by comparing with the published data. A possible biosynthetic pathway for the formation of 1 and 2 was proposed
Influence of personality traits on Facebook engagement and their effects on socialization behavior and satisfaction with university life
No full textSeveral factors influence Facebook users’ engagement. This study investigates the correlations between Facebook engagement and users’ personality traits. This study also analyses the impact of Facebook engagement on students’ socialization behavior and their satisfaction with their university life. A dataset of 994 Malaysian students was collected and used for analysis. The outcome of the analysis illustrates that students’ personality traits have a positive influence on Facebook engagement. Subsequently, Facebook engagement was found to have an influence over students’ socialization behavior and their satisfaction with university life. The results can be used by educators as a guide for their curriculum development, i.e., consideration of wider usage of Facebook in conducting courses