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81.
Hau Duc Tran Izumi Kinoshita Kensaku Azuma Tomoaki Iseki Yuta Yagi Jun-ichi Nunobe Thuy Thi Ta 《Environmental Biology of Fishes》2014,97(12):1387-1396
To examine regional specific diversity in development and growth of Ayu (Plecoglossus altivelis) larvae, we collected and compared collections from the Kalong estuary in Vietnam, and the Shimanto and Muko estuary, and the Niigata coast in Japan. Among the four areas, most of the morphometrics through ontogeny were similar except that the snout tended to be shorter and the anus hardly migrated in Kalong larvae. The snout length increased gradually with growth in the Vietnamese larvae, while this value increased significantly until ca. 10 mm BL, subsequently being constant up to 30 mm body length (BL) in the Japanese larvae. The water temperature when the larvae were collected was higher in the Kalong than in most of the Japan sites. Growth-rates estimated from otolith increments were from highest to lowest, Niigata (mean?=?0.54 mm/day), Kalong (0.47), Shimanto (0.38) and Muko (0.34). The higher growth-rates were obtained not in Niigata of highest latitudinal region, but in Kalong of lowest latitudinal region. This indicates that Ayu could experience their early developmental stages from the cool temperate to tropical regions, implying the potential biodiversity of this fish species in the world. 相似文献
82.
Zhifan Gao Wei Guo Xin Liu Wenhua Huang Heye Zhang Ning Tan William Kongto Hau Yuan-Ting Zhang Huafeng Liu 《PloS one》2014,9(11)
Intravascular Ultrasound (IVUS) is one ultrasonic imaging technology to acquire vascular cross-sectional images for the visualization of the inner vessel structure. This technique has been widely used for the diagnosis and treatment of coronary artery diseases. The detection of the calcified plaque with acoustic shadowing in IVUS images plays a vital role in the quantitative analysis of atheromatous plaques. The conventional method of the calcium detection is manual drawing by the doctors. However, it is very time-consuming, and with high inter-observer and intra-observer variability between different doctors. Therefore, the computer-aided detection of the calcified plaque is highly desired. In this paper, an automated method is proposed to detect the calcified plaque with acoustic shadowing in IVUS images by the Rayleigh mixture model, the Markov random field, the graph searching method and the prior knowledge about the calcified plaque. The performance of our method was evaluated over 996 in-vivo IVUS images acquired from eight patients, and the detected calcified plaques are compared with manually detected calcified plaques by one cardiology doctor. The experimental results are quantitatively analyzed separately by three evaluation methods, the test of the sensitivity and specificity, the linear regression and the Bland-Altman analysis. The first method is used to evaluate the ability to distinguish between IVUS images with and without the calcified plaque, and the latter two methods can respectively measure the correlation and the agreement between our results and manual drawing results for locating the calcified plaque in the IVUS image. High sensitivity (94.68%) and specificity (95.82%), good correlation and agreement (>96.82% results fall within the 95% confidence interval in the Student t-test) demonstrate the effectiveness of the proposed method in the detection of the calcified plaque with acoustic shadowing in IVUS images. 相似文献
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The Kosi coastal lake system, a chain of four interconnected basins, is located in the subtropical north-eastern corner of South Africa. Little information is available on zooplankton of the system and the main aim of this study is to report on zooplankton samples collected during 2002 and 2003. The set of samples consists of seasonal, subsurface mesozooplankton samples that were collected during nighttime in each of the lakes. A well-developed salinity gradient was evident along the interconnected lakes in the subsurface water during all seasons, ranging from freshwater in the upper lake Amanzamnyama to a maximum of 22 recorded in Lake Makhawulani. The zooplankton community structures of the lakes reflected the salinity gradient of the system, with some coastal marine taxa recorded in the lakes closer to the mouth and only freshwater taxa recorded in Lake Amanzamnyama. Mesozooplankton diversity and abundance were relatively low compared to other estuarine systems along the eastern coast of South Africa. The dominant taxa were calanoid copepods Acartiella natalensis and Pseudodiaptomus stuhlmanni and the mysid Mesopodopsis africana in the lower lakes, whereas cyclopoids Mesocyclops sp. and Thermocyclops sp. dominated the freshwater lake Amanzamnyama. 相似文献
85.
Modelling the effects of temperature and wetness on the polycyclic phase of Stemphylium vesicarium,the pathogen causing purple spot on asparagus (Asparagus officinalis L.)
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Henrik Bohlen‐Janssen Paolo Racca Bernhard Hau Alexandra Wichura 《Journal of Phytopathology》2018,166(5):333-345
The polycyclic phase of Stemphylium vesicarium is the key factor for the forecast and integrated control of purple spot on asparagus. The annual dynamics of airborne conidia were determined under field conditions by conidia traps. From 2013 to 2015, conidia became airborne at the earliest at mid‐July, but the number trapped was considerably enhanced only after mid‐August, early September. The cumulative percentage of trapped conidia was best described using a logistic function depending on the daily temperature sum (base 0°C) accumulated only on days with >0.2 mm of rainfall (R2 = .81). The germination of conidia was modelled by a generalized beta‐modified Chapman Richards function, and the germ tube length was modelled by a generalized beta‐power function. Conidia germinated in a wide temperature range, with an optimum at 23.3°C, whereas germ tube length had a narrow nearly optimum temperature range around 28.7°C, which indicates that infection by conidia is more restricted by germ tube growth than by germination. The effect of temperature on the number of lesions produced by two strains on green asparagus spears had the narrowest optimum range (optimum at 21.9°C) of all parts of the polycyclic phase. In plant tissue, the spread of the fungus depends on the mycelium growth. The mycelium growth of the four strains, which was modelled with data from a petri dish experiment, had an optimum temperature at 24.7°C. 相似文献
86.
Xin Liu Zhifan Gao Huahua Xiong Dhanjoo Ghista Lijie Ren Heye Zhang Wanqing Wu Wenhua Huang William Kongto Hau 《Biomechanics and modeling in mechanobiology》2016,15(6):1439-1456
The hemodynamic alteration in the cerebral circulation caused by the geometric variations in the cerebral circulation arterial network of the circle of Wills (CoW) can lead to fatal ischemic attacks in the brain. The geometric variations due to impairment in the arterial network result in incomplete cerebral arterial structure of CoW and inadequate blood supply to the brain. Therefore, it is of great importance to understand the hemodynamics of the CoW, for efficiently and precisely evaluating the status of blood supply to the brain. In this paper, three-dimensional computational fluid dynamics of the main CoW vasculature coupled with zero-dimensional lumped parameter model boundary condition for the CoW outflow boundaries is developed for analysis of the blood flow distribution in the incomplete CoW cerebral arterial structures. The geometric models in our study cover the arterial segments from the aorta to the cerebral arteries, which can allow us to take into account the innate patient-specific resistance of the arterial trees. Numerical simulations of the governing fluid mechanics are performed to determine the CoW arterial structural hemodynamics, for illustrating the redistribution of the blood flow in CoW due to the structural variations. We have evaluated our coupling methodology in five patient-specific cases that were diagnosed with the absence of efferent vessels or impairment in the connective arteries in their CoWs. The velocity profiles calculated by our approach in the segments of the patient-specific arterial structures are found to be very close to the Doppler ultrasound measurements. The accuracy and consistency of our hemodynamic results have been improved (to \(16.1 \pm 18.5\) %) compared to that of the pure-resistance boundary conditions (of 43.5 \(\pm \) 28 %). Based on our grouping of the five cases according to the occurrence of unilateral occlusion in vertebral arteries, the inter-comparison has shown that (i) the flow reduction in posterior cerebral arteries is the consequence of the unilateral vertebral arterial occlusion, and (ii) the flow rate in the anterior cerebral arteries is correlated with the posterior structural variations. This study shows that our coupling approach is capable of providing comprehensive information of the hemodynamic alterations in the pathological CoW arterial structures. The information generated by our methodology can enable evaluation of both the functional and structural status of the clinically significant symptoms, for assisting the treatment decision-making. 相似文献
87.
Outbred Bom:NMRI mice were weighed daily for 18 days from observation of a vaginal plug. In a separate experiment, fetuses and placentae were weighed on each day of pregnancy. Pregnancy can be determined with 99% certainty on day 12 of gestation by the maternal body weight increase from day 1. The pregnancy-specific proteins alpha-fetoprotein (m-AFP) and pregnancy-associated murine protein-2 (PAMP-2), of fetal and placental origin respectively, were detectable on days 8 and 10 in the maternal circulation. Significant correlations were observed between m-AFP and fetal weight and PAMP-2 and placental weight. These markers may therefore be useful in the monitoring of fetal growth and placental growth respectively. 相似文献
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90.
Koch HJ Klinkhammer-Schalke M Hofstädter F Bogdahn U Hau P 《Chronobiology international》2006,23(5):1047-1052
Seasonal distribution of birth rates was only recently described in patients with high-grade gliomas. We analyzed 501 cases from the database of a Regional Cancer Center in Bavaria to assess annual periodicity in the birth dates of glioma patients. Prior to analysis, the number of births per month was normalized [number of births×100,000/total number of births in Germany] to obtain birth rates per month. The approximation of the time series data by a one-year cosine model found that the glioblastoma birth rate exhibits a statistically significant annual variation, with the peak rate in January. Vitamin intake, infections, and other as-yet-unknown factors and exposures during pre- and perinatal early life may contribute to the seasonality of birth rate in patients with brain tumors. 相似文献