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Sand Waves Generation: A Numerical Investigation of the Infiernillo Channel in the Gulf of California

Open Journal of marine Science 2016年第3期6卷 412-422页

作者： Yovani montaño ley Noel Carbajal Instituto de Ciencias del mar y Limnología Universidad Nacional Autónoma de México Unidad Académica Mazatlán Mazatlán México Instituto Potosino de Investigación Científica y Tecnológica San Luis Potosí México

The effect of the coastal geometry on sand bed forms generation has been investigated for a tidal dominated area. Different hypothetical geometries of coastal channels with flat bottoms and unlimited sediment availability were exposed to strong oscillatory tidal currents to simulate the interaction of hydrodynamics and the bedload sediment transport. The hypothetical geometries stand for the idealization of the principal geographic features of the Infiernillo Channel, a coastal area of the Gulf of California where sandbanks and sand waves have been observed. A depth integrated hydrodynamic-numerical model and a parameterized formula to estimate the bedload sediment transport were applied coupled with a sediment conservation equation to determine the sea bottom morphodynamics. model predictions in the Infiernillo Channel were compared to available satellite imagery. This investigation demonstrates that a vertical integrated numerical model is able to reproduce the development of incipient sand waves that exist in the Infiernillo Channel. Incipient sandbanks and shoals were also simulated. Sand waves with wavelengths of about 200 m were calculated on the same locations where sand waves actually exist. A crucial finding of this research was to show that the geometry of a shallow water basin and the presence of tidal velocity gradients associated with abrupt changes in the coastline alignment were critical in determining the sand-bed pattern generation. We demonstrate that a vertical variation of tidal currents is not necessary to generate sand waves.

关键词： Sand Waves Tidal Hydrodynamics Bed Load Sediment Transport

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modelling tropical cyclone risks for present and future climate change scenarios using geospatial techniques

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International Journal of Digital Earth 2018年第3期11卷 246-263页

作者： muhammad Al-Amin Hoque Stuart Phinn chris Roelfsema Iraphne Childs Remote Sensing Research Centre School of Earth and Environmental SciencesThe University of QueenslandBrisbaneAustralia Department of Geography and Environment Jagannath UniversityDhakaBangladesh Queensland Centre for Population Research School of Earth and Environmental SciencesThe University of QueenslandBrisbaneAustralia

Tropical cyclones and their devastating impacts are of great concern to coastal communities *** appropriate approach integrating climate change scenarios at local scales is essential for producing detailed risk models to support cyclone mitigation *** study developed a simple cyclone risk-modelling approach under present and future climate change scenarios using geospatial techniques at local scales,and tested using a case study in Sarankhola Upazila from coastal *** storm-surge models were developed up to 100-year return periods.A local sea level rise scenario of 0.34 m for the year 2050 was integrated with surge models to assess the climate change *** resultant storm-surge models were used in the risk-modelling *** developed risk models successfully identified the spatial extent and levels of risk that match with actual extent and levels within an acceptable limit of *** result showed that cyclone risk areas increased with the increase of return *** study also revealed that climate change scenario intensified the cyclone risk area by 5–10%in every return *** findings indicate this approach has the potential to model cyclone risk in other similar coastal environments for developing mitigation plans and strategies.

关键词： Tropical cyclone geospatial techniques hazard risk climate change

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A Phase-Dependent Hypothesis for Locomotor Functions of Human Foot Complex

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Journal of Bionic Engineering 2008年第3期5卷 175-180页

作者： Lei Ren David Howard Lu-quan Ren chris Nester Li-mei Tian School of Physical Science and Engineering King＇s College of London University of London London WC2R 2LS UK Centre for Rehabilitation and Human Performance Research University of Salford Salford M5 4 WT UK Key Laboratory for Terrain-machine Bionics Engineering Jilin University Changchun 130022 P R. China

The human foot is a very complex structure comprising numerous bones, muscles, ligaments and synovial joints. As the only component in contact with the ground, the foot complex delivers a variety of biomechanical functions during human locomotion, e.g. body support and propulsion, stability maintenance and impact absorption. These need the human foot to be rigid and damped to transmit ground reaction forces to the upper body and maintain body stability, and also to be compliant and resilient to moderate risky impacts and save energy. How does the human foot achieve these apparent conflicting functions？ In this study, we propose a phase-dependent hypothesis for the overall locomotor functions of the human foot complex based on in-vivo measurements of human natural gait and simulation results of a mathematical foot model. We propse that foot functions are highly dependent on gait phase, which is a major characteristics of human locomotion. In early stance just after heel strike, the foot mainly works as a shock absorber by moderating high impacts using the viscouselastic heel pad in both vertical and horizontal directions. In mid-stance phase （-80% of stance phase）, the foot complex can be considered as a springy rocker, reserving external mechanical work using the foot arch whilst moving ground contact point forward along a curved path to maintain body stability. In late stance after heel off, the foot complex mainly serves as a force modulator like a gear box, modulating effective mechanical advantages of ankle plantiflexor muscles using metatarsal-phalangeal joints. A sound under- standing of how diverse functions are implemented in a simple foot segment during human locomotion might be useful to gain insight into the overall foot locomotor functions and hence to facilitate clinical diagnosis, rehabilitation product design and humanoid robot development.

关键词： biomechanics human foot locomotion rollover model shock absorber spring phase-dependent

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Effect of B vitamin supplementation on plasma homocysteine levels in celiac disease

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World Journal of Gastroenterology 2009年第8期15卷 955-960页

作者： muhammed Hadithi chris JJ mulder Frank Stam Joshan Azizi J Bart A Crusius Amado Salvador Pea Coen DA Stehouwer Yvo m Smulders Department of Gastroenterology VUmc University Medical Center Amsterdam PO Box 7057 Amsterdam 1007 MB The Netherlands Department of Internal medicine VUmc University Medical Center Amsterdam PO Box 7057 Amsterdam 1007 MB The Netherlands Laboratory of Immunogenetics Department of Pathology VUmc University Medical Center Amsterdam PO Box 7057 Amsterdam 1007 MB The Netherlands Department of Internal medicine Academic Hospital Maastricht P. Debyelaan 25 6229 HX Maastricht The Netherlands

AIm: To investigate the effect of vitamin supplements on homocysteine levels in patients with celiac disease. mETHODS: Vitamin B6, folate, vitamin B12, and fasting plasma homocysteine levels were measured in 51 consecutive adults with celiac disease [median (range) age 56 (18-63) years; 40% men, 26 (51%) had villous atrophy, and 25 (49%) used B-vitamin supplements] and 50 healthy control individuals matched for age and sex. Finally, the C677T polymorphism of 5,10-methylene tetrahydrofolate reductase (mTHFR) was evaluated in 46 patients with celiac disease and all control individuals. RESULTS: Patients with celiac disease and using vitamin supplements had higher serum vitamin B6 (P = 0.003),folate (P min B12 (P = 0.012) levels than patients who did not or healthy controls (P = 0.035, P min B6, folate, and vitamin B12, respectively). Lower plasma homocysteine levels were found in patients using vitamin supplements than in patients who did not (P = 0.001) or healthy controls (P = 0.003). However, vitamin B6 and folate, not vitamin B12, were significantly and independently associated with homocysteine levels. Twenty-four (48%) of 50 controls and 23 (50%) of 46 patients with celiac disease carried the mTHFR thermolabile variant T-allele (P = 0.89). CONCLUSION: Homocysteine levels are dependent on marsh classification and the regular use of B-vitamin supplements is effective in reduction of homocysteine levels in patients with celiac disease and should be considered in disease management.

关键词： Celiac disease Homocysteine Vitamin supplements

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Size distribution and diffuse pollution impacts of PAHs in street dust in urban streams in the Yangtze River Delta

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Journal of Environmental Sciences 2009年第2期21卷 162-167页

作者： ZHAO Hongtao YIN Chengqing CHEN meixue WANG Weidong Jefferies chris SHAN Baoqing State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Urban Water Technology Centre University of Abertay Dundee Bell Street Dundee Scotland DD1 1HG UK

Particles of dust washed off streets by stormwater are an important pathway of polyaromatic hydrocarbons （PAHs） into urban streams. This article presented a comprehensive assessment of the size distribution of PAHs in street dust particles, the potential risks of the particles in urban streams, and the sources and sinks of PAHs in the stream network. This assessment was based on measurements of 16 PAHs from the USEPA priority list in street dust particles and river sediments in Xincheng, China. The content of total PAHs ranged from 1629 to 8986 Dg/kg in street dust particles, where smaller particles have a higher concentrations. Approximately 55% of the total PAHs were associated with particles less than 250 μm which accounted for 40% of the total mass of street dust. The PAH quantities increased from 2.41 to 46.86 μg/m2 in the sequence of new residential, rising through main roads, old town residential, commercial and industrial areas. The sediments in stream reaches in town were found to be sinks for street dust particle PAHs. The research findings suggested that particle size, land use and the hydrological conditions in the stream network were the factors which most influenced the total loads of PAH in the receiving water bodies.

关键词： PAHs street dust particle size distribution land use pollutant load

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Human-altered soils–Signatures of Anthrosols and their potential for arable lands

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Soil Ecology Letters 2023年第3期5卷 109-121页

作者： michael O.Asare Wazi Apoh Jerry Owusu Afriyie Jiřina Száková Dinkayehu Alamnie Asrade Department of Agroenvironmental Chemistry and Plant Nutrition Faculty of Agrobiology Food and Natural ResourcesCzech University of Life SciencesKamýcká129CZ-16521 Prague 6Czech Republic Department of Archaeology and Heritage Studies University of GhanaP.O.Box L.G.3LegonGhana Department of Animal Science and Food Processing in the Tropics Faculty of Tropical AgriSciencesCzech University of Life SciencesPragueKamycka 129Prague 6–Suchdol CZ1651400Czech Republic

The fertility of human-altered soils,Anthrosols,developed from past settlement activities for crop production is scarcely *** study evaluated the fertility of Anthrosols developed from the 15th to mid-20th century AD settlement in Old Buipe,Savanna region,Ghana,to determine whether abandoned localities are suitable for arable *** activities enhanced the physical attributes of the Anthrosols:brown to dark brown intergrain fine soil,15%−35%organic matter,15%−30%potsherd,and 5%−15%charred *** Anthrosols were slightly acidic to neutral reactions(pH_([H_(2)O])5.67−6.83,pH_([cacl_(2)])5.83−6.95),high cation exchange capacity(CEC;18.77−45.31me/100 g),electric conductivity(EC=0.28−0.36 dS m^(−1)),accumulation,and distribution of organic C,total N,P,mn,Cu,Zn,K,and Fe,and available P,K,Ca,mg,S,mn,Fe,Cu,and ***-available nutrients were comparatively higher than concentrations in non-anthropogenic *** level of releasability(bioavailable fractions of total concentrations)of P,K,Ca,mn,Fe,Cu,and Zn partly compensates for low plant-available *** of chemical and physical properties of Anthrosols make them fertile for arable *** signatures of settlement activities are strong and can remain in soils for a long time,even under harsh environmental conditions.

关键词： arable field Anthrosols organic matter physical properties releasability settlement activities

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Environmental mercury exposure, semen quality and reproductive hormones in Greenlandic Inuit and European men： a cross-sectional study

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Asian Journal of Andrology 2013年第1期15卷 97-104页

作者： Emina mocevic ina O Specht Jacob L marott Aleksander Giwercman Bo AG Jonsson Gunnar Toft Thomas Lundh Jens Peter Bonde Department of Occupational and Environmental medicine Copenhagen University Hospital Bispebjerg Copenhagen NV DK-2400 Denmark Reproductive medicine Centre Sk~ne University Hospital Malm6 Lund University Malm6 SE-20502 Sweden Division of Occupational and Environmental medicine Department of Laboratory Medicine Lund University Lund SE-22185 Sweden Department of Occupational medicine Aarhus University Hospital Aarhus DK-8000 Denmark

Several animal studies indicate that mercury is a male reproductive toxicant, but human studies are few and contradictory. We examined semen characteristics and serum levels of reproductive hormones in relation to environmental exposure to mercury. Blood and semen samples were collected from 529 male partners of pregnant women living in Greenland, Poland and Ukraine between may 2002 and February 2004. The median concentration of the total content of mercury in whole blood was 9.2 ng ml-1 in Greenland （0.2- 385.8 ng ml-1）, 1.0 ng m1-1 in Poland （0.2-6.4 ng ml-z） and 1.0 ng ml-I in Ukraine （0.2-4.9 ng ml-1）. We found a significantly positive association between the blood levels of mercury and serum concentration of inhibin B in men from Greenland （p=0.074, 95% confidence interval （CI）=0.021 to 0.126） and in an analysis including men from all three regions （p=0.067, 95% C1=0.024 to O. 110）. The association may be due to beneficial effects of polyunsaturated fatty acids （PUFAs）, which are contained in seafood and fish. No significant association （P〉O.05） was found between blood concentrations of mercury and any of the other measured semen characteristics （semen volume, total sperm count, sperm concentration, morphology and motility） and reproductive hormones （free androgen index {FAI）, follicle-stimulating hormone （FSH）, luteinizing hormone （LH）, testosterone and LH xtestosterone） in any region. In conclusion, the findings do not provide evidence that environmental mercury exposure in Greenlandic and European men with median whole blood concentration up to 10 ng m1^-1 has adverse effects on biomarkers of male reproductive health.

关键词： blood mercury concentration environmental mercury exposure male fertility reproduction reproductive hormones semen characteristics semen quality

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Personalized precision radiotherapy and its evolving role for human papillomavirus-positive oropharyngeal cancer

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Journal of the National Cancer Center 2023年第1期3卷 72-82页

作者： Hayden Ansinelli chris Gay Steven Nguyen christopher m.morrison Jared R.Robbins University of Arizona College of medicine Department of Radiation OncologyTucsonUnited States

Human papilloma virus(HPV)-associated oropharyngeal cancer(OPC)is a unique entity with increased respon-siveness to treatment and excellent oncologic *** purpose of this narrative review is to highlight how an improved prognosis for HPV(+)tumors and an ever-increasing understanding of the risk factors,risk stratification,and areas of potential spread are shaping management ***,we aim to detail how advances in treatment technology on both the surgical and radiation fronts are facilitating the delivery of increas-ingly personalized and precise *** review will describe key aspects of recent and currently-ongoing trials investigating the de-escalation and individualization of treatment in this patient cohort,and how they are building a foundation for distinct treatment paradigms for HPV(+)*** studies into the integration of biomarker-guided treatments combined with clinical trial enrollment will help ensure a future of personalized treatments and improved outcomes,both in terms of oncologic outcomes and toxicity,for patients with HPV(+)OPC.

关键词： Radiotherapy De-escalation Human papillomavirus Oropharyngeal cancer

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Temporal and spatial distributions of dominant shrimp stocks and their relationship with the hydrological environment in the East China Sea

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Chinese Journal of Oceanology and Limnology 2007年第4期25卷 386-397页

作者：吕华庆宋海棠 chris BAYLY marine Science School of Zhejiang Ocean University marine Fisheries Res.Inst.of Zhejiang Province myalla Consultants 12 ArivruaichIsle of LewisScotlandHS2 9LEUK

To provide a scientific and technological base for fishery administration, holding a moratorium on fishing, and combating habitat degradation, a shrimp stock survey was carried out in may, August, and November 1998 and in February 1999. The study was conducted in the area between 26°00＇ N and 33°00＇ N and to the west of 127°00＇ E in the East China Sea using a multi-sac trawl-net, with 115 stations being sampled. Up to 2001, we had found 121 species, which belong to 63 genera under 22 families, and 41 species are of high economic value and in great abundance. Nine shrimp species were of great economic importance, whose stock accounted for 76.8% of the demersal total. They were Parapenaeus fissuroides, metapenaeopsis philippi, Palaemon gravieri, metapenaeopsis barbata, Solenocera koelbeli, Solenocera crassicornis, Trachypenaeus curvirostris, Solenocera melantho and Parapenaeopsis hardwickii （listed in stock order）. The nine species belong to the eurythermal and eurysaline community and high thermal and high saline community, had different migration patterns and stocks, and their distribution patterns could be generally classified into three types：（1） dominating in the north or the south; （2） dominating to the north of and in the coast to the south of 30000＇ N; and （3） dominating to the east of 60 m isobath, which were related to six water masses in the ECS near two lines, i.e., the 60 m isobath and 30°00＇N latitudinal lines. Densely habited shrimps were found in all four seasons due to temperature and salinity frontiers and upwelling. The general stock density index was relatively higher in spring, summer, and autumn, when it surpassed 10 kg/h, while in winter, it was only 6.8 kg/h which might be caused by overfishing. According to the spawning areas of the nine species and their distribution patterns, to attain sustainable development of the shrimp fishery in the ECS, it is imperative to protect fishing areas and to hold a moratorium on catching to the west of 60 m

关键词： shrimp stock survey conservation moratorium community water system

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Double balloon endoscopy associated pancreatitis:A description of six cases

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World Journal of Gastroenterology 2008年第5期14卷 720-724页

作者： Soeresh VA Jarbandhan Stijn JB van Weyenberg Willem m van der Veer Dimitri GN Heine chris JJ mulder maarten AJm Jacobs Small Bowel Unit Department of Gastroenterology VU University Medical Center Amsterdam The Netherlands

AIm:To perform a single-center analysis of all double balloon endoscopy (DBE) related cases of pancreatitis identified prospectively from a recorded DBE-complication database. mETHODS:From November 2003 until January 2007, 603 DBE procedures were performed on 412 patients, with data on complications recorded in a database. The setting was a tertiary care center offering DBE. DBE was performed from the antegrade or retrograde route. Out-come measurements included age, gender, medication, indication, DBE-endoscope type, insertion depth, proce-dure duration, findings, interventions, post-procedural abdominal pain, and post-procedural hospitalization. RESULTS:This is the largest single-center study report-ing on post-DBE pancreatitis prospectively. Six patients (1.0%) developed post-DBE pancreatitis, all after antegrade DBE. There was no association with gender, duration of the procedure or type of endoscope. The mean age was 51.9 years (range 25-78). Four patients had severe pancreatitis. Of these, two had inflammatory signs in the body-tail region, one had pancreatitis in the tail region, and the total pancreas was involved in one. CONCLUSION:The incidence of post-DBE pancreatitis in our series is higher than previously reported. We found no relation with DBE-endoscope type. The inflammatory changes occurred in the body-tail region of the pancreas, suggesting that post-DBE pancreatitis is caused by repetitive mechanical strain on the pancreas.

关键词： Double balloon endoscopy Small intestine Adverse events Complications Pancreatitis Enteroscopy

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