2,850 research outputs found

    The (1|1)-Centroid Problem on the Plane Concerning Distance Constraints

    Get PDF

    Examination of Existing DMT-Based Liquefaction Evaluation Methods by Side-by-Side DMT and CPT Tests

    Get PDF
    This study employed the field measurements of flat dilatometer test (DMT) and cone penetration test (CPT) presented by a recent study (Tsai et al. 2009) and additional DMT and CPT data conducted in this present study to examine the existing DMT-based liquefaction evaluation methods. Specifically, the DMT and CPT were conducted side-by-side at each of six in-situ sites and thus it is feasible to incorporate those test results into validating the existing DMT-based methods such as Grasso and Maugeri (2006), Monaco et al. (2005), and Rena and Chameau (1991). The DMT parameter, horizontal stress index (KD), is used as an indicator for assessing liquefaction resistance of soils. The analysis results revealed that the existing KD-based liquefaction evaluation methods would overestimate CRR of soils, which leads to overestimate the factor of safety against liquefaction. Also, the estimation of DMT-KD values by using the CPT-qc as well as the correlation between DMT-KD and CPT-qc proposed by the previous studies would be significantly less than field measurements of DMT-KD. However, it should be noted that it is desirable to incorporate more field measurements to further verify this finding

    Late onset of large benign ductus arteriosus aneurysm presented with increased nuchal translucency and cystic hygroma at first trimester Down syndrome screening

    Get PDF
    AbstractObjectiveFetal ductus arteriosus aneurysm (DAA) is a rare but potentially risky congenital heart disease. It is often not diagnosed until the third trimester because of its asymptomatic nature and late onset. In rare occasions, DAA may result in serious complications; therefore, prenatal diagnosis is helpful.Case ReportHerein, we report the case of a foetus with cystic hygroma and increased nuchal translucency in the first trimester (but regressed at 20-week anomalous scan). Karyotyping indicated a 46 XY genotype. A large vascular mass was noted at the apex of the left lung by Doppler ultrasound at 38 weeks of gestation, with a diameter of 12.5 mm. After birth, echocardiography showed a patent ductus arteriosus with aneurysmal dilatation (17 mm as the largest diameter); thus, DAA was impressed. Chest computed tomography and three-dimensional angiography confirmed the large aneurysmal dilatation of the ductus arteriosus with a closed end at the pulmonary arterial side.ConclusionThe male infant survived, but presented mild respiratory distress at birth. He was discharged at 24 days of age. At that time, DAA had regressed partially (diameter of 8.5 mm and much less blood flow), and it fully regressed at 40 days of age

    Molecular Line Profiles of Collapsing Gas Clouds

    Get PDF
    Emission line profiles of tracer molecule H2_2CO 140 GHz transition from gravitational core collapsing clouds in the dynamic process of forming protostars are calculated, using a simple ray-tracing radiative transfer model. Three self-similar dynamic inside-out core collapse models -- the conventional polytropic model, the empirical hybrid model and the isothermal model -- for star-forming molecular clouds are examined and compared. The isothermal model cannot produce observed asymmetric double-peak molecular line profiles. The conventional polytropic model, which gives flow velocity, mass density and temperature profiles self-consistently, can produce asymmetric double-peak line profiles for a core collapsing cloud. In particular, the blue peak is stronger than the red peak, consistent with a broad class of molecular line profile observations. The relative strengths of the blue and red peaks within a molecular line profile are determined by the cloud temperature gradient. The conventional polytropic model can be utilized to produce molecular line-profile templates, for extracting dynamical information from line spectra of molecular globules undergoing a gravitational core collapse. We show a sample fit using the 140 GHz H2_2CO emission line from the central region of the molecular globule B335 by our model with γ=1.2\gamma=1.2. The calculation of line profiles and fitting processes also offer a scenario to estimate the protostellar mass, the kernel mass accretion rate, and the evolution time scale of a core collapsing cloud. Our model can be readily adapted to other tracer molecules with more or less constant abundances in star-forming clouds.Comment: 12 pages, 10 figures, accepted for publication in MNRA

    Plantar fasciopathy: revisiting the risk factors

    Get PDF
    Background Plantar fasciopathy is the most common cause of acquired sub-calcaneal heel pain in adults. To-date, research of this condition has mainly focused on management rather than causal mechanisms. The aetiology of plantar fasciopathy is likely to be multifactorial, as both intrinsic and extrinsic risk factors have been reported. The purpose of this review is to critically reevaluate risk factors for plantar fasciopathy. Methods A detailed literature review was undertaken using English language medical databases. Results No clear consensus exists as to the relative strength of the risk factors reported. Conclusions To-date numerous studies have examined various intrinsic and extrinsic risk factors implicated in the aetiology of plantar fasciopathy. How these factors interact may provide useful data to establish an individuals’ risk profile for plantar fasciopathy and their potential for response to treatment. Further research is indicated to rank the relative significance of these risk factors

    Mean structure and fluctuations of the Kuroshio east of Taiwan from in situ and remote observations

    Get PDF
    Author Posting. © The Oceanography Society, 2015. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 28, no. 4 (2015): 74–83, doi:10.5670/oceanog.2015.83.The Kuroshio is important to climate, weather prediction, and fishery management along the northeast coast of Asia because it transports tremendous heat, salt, and energy from east of the Philippines to waters southeast of Japan. In the middle of its journey northward, the Kuroshio’s velocity mean and its variability east of Taiwan crucially affect its downstream variability. To improve understanding of the Kuroshio there, multiple platforms were used to collect intensive observations off Taiwan during the three-year Observations of the Kuroshio Transports and their Variability (OKTV) program (2012–2015). Mean Kuroshio velocity transects show two velocity maxima southeast of Taiwan, with the primary velocity core on the onshore side of the Kuroshio exhibiting a mean maximum velocity of ~1.2 m s–1. The two cores then merge and move at a single velocity maximum of ~1 m s–1 east of Taiwan. Standard deviations of both the directly measured poleward (v) and zonal (u) velocities are ~0.4 m s–1 in the Kuroshio main stream. Water mass exchange in the Kuroshio east of Taiwan was found to be complicated, as it includes water of Kuroshio origin, South China Sea Water, and West Philippine Sea Water, and it vitally affects heat, salt, and nutrient inputs to the East China Sea. Impinging eddies and typhoons are two of the principal causes of variability in the Kuroshio. This study’s models are more consistent with the observed Kuroshio than with high-frequency radar measurements.This study was sponsored by the Ministry of Science and Technology (MOST) of the ROC (Taiwan) under grants NSC 101-2611-M-002-018-MY3, NSC 101-2611- M-019-002, NSC 102-2611-M-002-017, NSC 102-2611- M-019-012, MOST 103-2611-M-002-014, and MOST 103-2611-M-002-018. MA was sponsored by the US Office of Naval Research under grant N00014- 12-1-0445. YHT was supported by NSF Earth System Model (EaSM) Grant 1419292

    State-of-the-Art CT Imaging Techniques for Congenital Heart Disease

    Get PDF
    CT is increasingly being used for evaluating the cardiovascular structures and airways in the patients with congenital heart disease. Multi-slice CT has traditionally been used for the evaluation of the extracardiac vascular and airway abnormalities because of its inherent high spatial resolution and excellent air-tissue contrast. Recent developments in CT technology primarily by reducing the cardiac motion and the radiation dose usage in congenital heart disease evaluation have helped expand the indications for CT usage. Tracheobronchomalacia associated with congenital heart disease can be evaluated with cine CT. Intravenous contrast injection should be tailored to unequivocally demonstrate cardiovascular abnormalities. Knowledge of the state-of-the-art CT imaging techniques that are used for evaluating congenital heart disease is helpful not only for planning and performing CT examinations, but also for interpreting and presenting the CT image findings that consequently guide the proper medical and surgical management

    Cancellous bone and theropod dinosaur locomotion. Part III—Inferring posture and locomotor biomechanics in extinct theropods, and its evolution on the line to birds

    Get PDF
    This paper is the last of a three-part series that investigates the architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs, and uses cancellous bone architectural patterns to infer locomotor biomechanics in extinct non-avian species. Cancellous bone is highly sensitive to its prevailing mechanical environment, and may therefore help further understanding of locomotor biomechanics in extinct tetrapod vertebrates such as dinosaurs. Here in Part III, the biomechanical modelling approach derived previously was applied to two species of extinct, non-avian theropods, Daspletosaurus torosus and Troodon formosus. Observed cancellous bone architectural patterns were linked with quasi-static, three-dimensional musculoskeletal and finite element models of the hindlimb of both species, and used to derive characteristic postures that best aligned continuum-level principal stresses with cancellous bone fabric. The posture identified for Daspletosaurus was largely upright, with a subvertical femoral orientation, whilst that identified for Troodon was more crouched, but not to the degree observed in extant birds. In addition to providing new insight on posture and limb articulation, this study also tested previous hypotheses of limb bone loading mechanics and muscular control strategies in non-avian theropods, and how these aspects evolved on the line to birds. The results support the hypothesis that an upright femoral posture is correlated with bending-dominant bone loading and abduction-based muscular support of the hip, whereas a crouched femoral posture is correlated with torsion-dominant bone loading and long-axis rotation-based muscular support. Moreover, the results of this study also support the inference that hindlimb posture, bone loading mechanics and muscular support strategies evolved in a gradual fashion along the line to extant birds

    Predictors of betel quid chewing behavior and cessation patterns in Taiwan aborigines

    Get PDF
    BACKGROUND: Betel quid, chewed by about 600 million people worldwide, is one of the most widely used addictive substances. Cessation factors in betel quid chewers are unknown. The present study explores prevalence and the quit rate of betel quid chewing in Taiwan aborigines. Our goal was to delineate potential predictors of chewing cessation. METHODS: A stratified random community-based survey was designed for the entire aborigines communities in Taiwan. A total of 7144 participants were included between June 2003 and May 2004 in this study. Information on sociodemographic characteristics, such as gender, age, obesity, education years, marital status, ethnicity, and habits of betel quid chewing, smoking and drinking was collected by trained interviewers. RESULTS: The prevalence of betel quid chewers was 46.1%. Betel quid chewing was closely associated with obesity (OR = 1.61; 95% CI: 1.40–1.85). Betel quid chewers were most likely to use alcohol and cigarettes together. Quit rate of betel quid chewers was 7.6%. Betel quid chewers who did not drink alcohol were more likely to quit (OR = 1.89; 95% CI: 1.43–2.50). Alcohol use is a significant factor related to cessation of betel quid chewing, but smoking is not. CONCLUSION: Taiwan aborigines have a high prevalence of betel quid chewers and a low quit rate. Alcohol use is strongly association with betel quid chewing. Efforts to reduce habitual alcohol consumption might be of benefit in cessation of betel quid chewing
    corecore