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A Two-Step Growth Curve: Approach to the von Bertalanffy and Gompertz Equations

Advances in Pure Mathematics 2016年第5期6卷 321-330页

作者： Laura Rogers-Bennett Donald W. Rogers California Department of Fish and Wildlife and Karen C. Drayer Wildlife Health Center UC Davis CA USA Bodega Marine Laboratory Bodega Bay CA USA Chemistry Department Long Island University Brooklyn NY USA friday harbor laboratories Whiteley Center University of Washington Friday Harbor WA USA

Many curves have been proposed and debated to model individual growth of marine invertebrates. Broadly, they fall into two classes, first order (e.g. von Bertalanffy) and sigmoidal (e.g. Gompertz). We provide an innovative approach which demonstrates that the growth curves are not mutually exclusive but that either may arise from a simple three-stage growth model with two steps (k1 and k2) depending on the ratio of the growth parameters . The new approach predicts sigmoidal growth when is close to 1, but if either growth from stage A to stage B or B to C is fast relative to the other, the slower of the two steps becomes the growth limiting step and the model reduces to first order growth. The resulting curves indicate that there is a substantial difference in the estimated size at time t during the period of active growth. This novel two-step rate model generates a growth surface that allows for changes in the rate parameters over time as reflected in the new parameter n(t) = k1(t) - k2(t). The added degree of freedom brings about individual growth trajectories across the growth surface that is not easily mapped using conventional growth modeling techniques. This two (or more) stage growth model yields a growth surface that allows for a wide range of growth trajectories, accommodating staged growth, growth lags, as well as indeterminate growth and can help resolve debates as to which growth curves should be used to model animal growth. This flexibility can improve estimates of growth parameters used in population models influencing model outcomes and ultimately management decisions.=

关键词： Growth Model Growth Surface Rate Equation Staged Growth Population Models

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Low Electrical Resistance Properties of Acupoints:Roles of NOergic Signaling Molecules and Neuropeptides in Skin Electrical Conductance

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Chinese Journal of Integrative Medicine 2021年第8期27卷 563-569页

作者： MA Sheng-xing Lundquist Institute for Biomedical Innovation at harbor University of California at Los Angeles(UCLA)Medical Center and Department of Obstetrics and Gynecology David Geffen School of Medicine at UCLA and Harbor-UCLA Medical CenterTorranceCA 90502United States

Early studies from several independent laboratories demonstrated that acupoints possess the characteristics of low electrical *** devices are developing to increase the reliability of electrical skin impedance measurements for counteracting the factors including skin dryness,skin thickness,size of the sensing electrode,pressure applied on the electrode,interelectrode distance,room temperature,and *** studies have identified that blood vessels,hair follicles,and nervous components are enhanced in the meridians/acupoints,which represent areas of potentially high neuronal *** evidence shows that nitric oxide(NO)concentrations are enhanced in skin acupoints/meridians.L-arginine-derived NO synthesis modifies skin norepinephrine(NE)synthesis/release in acupoints/meridians,and NO-NE activations play an important role in mediating the skin conductance responses to electrical *** signaling molecules interact with gap junction and transient receptor potential vanilloid *** studies reported that the high conductance at acupoints is a result of the release of the neuropeptides substance P and calcitonin gene-related peptide during neurogenic inflammation in the referred pain *** body conditions caused considerable changes in skin conductance or impedance at *** systematic research with an improved equipment and research design to avoid the influencing factors are requested for a definite answer in this field,the results from anatomical and biochemical studies consistently show that acupoints exist higher levels of nervous components,and NOergic signaling molecules and neuropeptides involved in the skin low resistance at *** increased interest in the acupoints/meridians has led to an open-minded attitude towards understanding this system,which is fundamental important to establish the valid aspects of scientific basis of Chinese medicine mechanisms and therapies.

关键词： acupuncture points skin electric resistance nitric oxide norepinephrine transient receptor potential vanilloid type-1 neuropeptides

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A Note on the Derivation of Wave Action Balance Equation in Frequency Space

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China Ocean Engineering 2011年第1期25卷 133-138页

作者： Tai-Wen HSU Jian-Ming LIAU Shin-Jye LIANG Shan-Hwei OU Yi-Ting LI Department of Hydraulic and Ocean Engineering National Cheng Kung University Taiwan Ocean Research Institute National Applied Research Laboratories Department of Marine Environmental Informatics National Taiwan Ocean University Department of harbor and River Engineering National Taiwan Ocean University Institute of Ocean Technology and Marine Affairs National Cheng Kung University

In this paper the wave action balance equation in terms of frequency-direction spectrum is derived. A theoretical formulation is presented to generate an invariant frequency space to replace the varying wavenumber space through a Jacobian transformation in the wave action balance equation. The physical properties of the Jacobian incorporating the effects of water depths are discussed. The results provide a theoretical basis of wave action balance equations and ensure that the wave balance equations used in the SWAN or other numerical models are correct. It should be noted that the Jacobian is omitted in the wave action balance equations which are identical to a conventional action balance equation.

关键词： wave action balance equation wavenumber-spectrum frequency-spectrum Jacobian

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Amplification of chromosome 21q22.3 harboring trefoil factor family genes in liver fluke related cholangiocarcinoma is associated with poor prognosis

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World Journal of Gastroenterology 2006年第26期12卷 4143-4148页

作者： Kanuengnuch Muenphon Temduang Limpaiboon Patcharee Jearanaikoon Chawalit Pairojkul Banchob Sripa Vajarabhongsa Bhudhisawasdi Department of Clinical Chemistry Center for Research and Development of Medical Diagnostic laboratories Faculty of Associated Medical SciencesKhon Kaen UniversityKhon Kaen 40002Thailand Department of Pathology Liver Fluke and Cholangiocarcinoma Research Center Faculty of MedicineKhon Kaen UniversityKhon Kaen 40002Thailand Department of Surgery Liver Fluke and Cholangiocarcinoma Research Center Faculty of MedicineKhon Kaen UniversityKhon Kaen 40002Thailand

AIM： To determine allelic imbalance on chromosomal region 21q22-qter including trefoil factor family genes （TFF） in cholangiocarcinoma （CCA） patients and analyze the correlation between allelic imbalances and clinicopathological parameters. METHODS： Quantitative PCR amplification was performed on four microsatellite markers and trefoil factor family genes （TFF1, TFF2, and TFF3） using a standard curve and SYBR Green I dye method. The relative copy number was determined by DNA copy number of tested locus to reference locus. The relative copy number was interpreted as deletion or amplification by comparison with normal reference range. Associations between allelic imbalance and clinicopathological parameters of CCA patients were evaluated by χ^2-tests. Kaplan-Meier method was used to analyze survival. RESULTS： The frequencies of amplification at D21S1890, D21S1893, and TFF3 were 32.5%, 30.0%, and 28.7%, respectively. Patients who had amplification at regions covering D21S1893, D21S1890, and TFF showed poor prognosis, whereas patients who had deletion showed favorable prognosis （mean： 51.7 wk vs 124.82 wk, P = 0.012）. Multivariate Cox regression analysis revealed that amplification of D21S1893, D21S1890 and TFF, blood vessel invasion, and staging were associated with poor prognosis. CONCLUSION： D21S1893-D21S1890 region may harbor candidate genes especially TFF and serine protease family, which might be involved in tumor invasion and metastasis contributing to poor survival. The amplification in this region may be used as a prognostic marker in the treatment of CCA patients.

关键词： Cholangiocarcinoma Amplification on chromosome 21 Trefoil factor family Quantitative PCR Liver fluke

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Lead isotope and trace metal characteristics of particulates accumulated on vehicular tunnel ceilings in Hong Kong and Guangzhou, SE China

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Chinese Journal Of Geochemistry 2006年第B8期25卷 75-75页

作者： Nurdan S. Duzgoren-Aydin Zhiguang SONG Adnan Aydin Coby C.S. Wong Minggang YOU Xiangdong LI Department of Earth Sciences The University of Hong Kong Pokfulam Road Hong Kong SAR China State Key laboratories of Organic Geochemistry Guangzhou Institute of Geochemistry Guangzhou 510640 China Department of Civil and Structural Engineering The Hong Kong Polytechnic University Hong Kong SAR China

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