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Population structure and mating system of the Red-crested Korhaan(Lophotis ruficrista) in South Africa

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Chinese Birds 2015年第1期5卷 43-51页

作者： johann H van Niekerk Department of Environmental Sciences College of Agriculture and Environmental Sciences University of South Africa

Background: The mating system of the korhaans and bustards in southern Africa is either based on polygyny or monogamy. The Red-crested Korhaan(Lophotis ruficrista) has been described as polygynous but otherwise very little is known about its breeding biology. The aims were to describe the population structure and male behavior during ***: The data collected for this paper was mainly based on field transect surveys carried out in 2009, 2010 and 2011. The population structure of the Red-crested Korhaan in the temperate Borakalalo Game Reserve(BGR)was compared with that in the arid Molopo Nature Reserve(MNR)(both situated in the North West province of South Africa). The study was mainly conducted in the BGR but additional work was conducted in the MNR for ***: The difference in mean group sizes between MNR(1.03) and BGR(1.07) was statistically not *** sizes were not affected by climate despite the fact that the BGR received about 650 mm precipitation per annum and the MNR about 200 mm. In both reserves the apparent sex ratios were skewed in favor of males(1:0.29 in the BGR and 1:0.1 in the MNR). The population was dispersed in a clumped manner which is ascribed to the formation of leks. Leks were positioned in open habitat while females invariably concealed themselves under ***: The leks formed the pivot of the mating system of the Red-crested Korhaan and are identifiable social structures that field ecologists can use to monitor population stability.

关键词： Lophotis ruficrista Leks Mating system Dispersion Group size

Chemoinformatics-an important scientific discipline

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计算机与应用化学 2005年第10期22卷 827-831页

作者： johann Gasteiger Computer-Chemie-Centrum and Institute of Organic Chemistry University Erlangen-Nuremberg 91052 Erlangen Germany

Chemoinformatics is the application of informatics methods to solve chemical problems. Although this term was introduced only a few years ago, this field has a long history with its roots going back more than 40 years. These different origins have now merged into a discipline of its own that is full of activities. All areas of chemistry from analytical chemistry to drug design can benefit from chemoinformatics methods. And there are still many challenging chemical problems waiting for solutions through the further development of chemoinformatics.

关键词：化学信息学科建设分析化学信息技术素质教育

Oxidative stress: the lowest common denominator of multiple diseases

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Neural Regeneration Research 2019年第2期14卷 238-241页

作者： Veronika Matschke Carsten Theiss johann Matschke Institute of Anatomy Department of Cytology Ruhr University Bochum Institute of Cell Biology (Cancer Research) University of Duisburg-Essen University Hospital Essen

Oxygen is essential to the human life and life of all aerobic organisms. The complete oxidation of nutrients for the biological energy supply is one of the most important prerequisites for the formation of higher life forms. However, cells that benefit from oxidative respiration also suffer from reactive oxygen species because they adapted to oxygen as an energy source. Healthy cells balance the formation and elimination of reactive oxygen species thereby creating and keeping reactive oxygen species-homeostasis. When the concentration of free radicals exceeds a critical level and homeostasis is disturbed, oxidative stress occurs leading to damage of multiple cellular molecules and compartments. Therefore, oxidative stress plays an important role in the physiology and pathology of various diseases. Often, the antioxidant protection system becomes pathologically unbalanced in the genesis of several diseases, leading to functional losses of the organism, as in the case of amyotrophic lateral sclerosis, or cells develop metabolic mechanisms to use this system as protection against external influences, such as in the case of glioblastoma cells. Either way, understanding the underlying deregulated mechanisms of the oxidative protection system would allow the development of novel treatment strategies for various diseases. Thus, regardless of the direction in which the reactive oxygen species-homeostasis disequilibrate, the focus should be on the oxidative protection system.

关键词： neurodegenerative disease amyotrophic lateral sclerosis cancer glioblastoma reactive oxygen species metabolism antioxidant protection system

Neutron-antineutron oscillations in the deuteron studied with NN and ■N interactions based on chiral effective field theory

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Chinese Physics C 2020年第3期44卷 28-32页

作者： johann Haidenbauer Ulf-G.Meiβner Institute for Advanced Simulation Institut für Kernphysik and Jülich Center for Hadron PhysicsForschungszentrum JülichD-52425 JülichGermany Helmholtz-Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics Universität Bonn53115 BonnGermany Tbilisi State University 0186 TbilisiGeorgia

Neutron-antineutron(n−n)oscillations in the deuteron are ***,the deuteron lifetime is calculated in terms of the free-space n−n oscillation time τn−n based on NN and NN interactions derived within chiral effective field theory(EFT).This results in(2.6±0.1)×10^22τ2^n−n s,which is close to the value obtained by Dover and collaborators more than three decades ago,but disagrees with recent EFT calculations that were performed within the perturbative scheme proposed by Kaplan,Savage,and *** reasons for the difference are discussed.

关键词： neutron-antineutron oscillations chiral effective field theory NN interaction antinucleon-nucleon interaction

Measurement and significance of sperm morphology

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Asian Journal of Andrology 2011年第1期13卷 59-68页

作者： Roelof Menkveld Cas AG Holleboom johann PT Rhemrev Andrology Laboratory Department of Obstetrics and Gynaecology Tygerberg Academic Hospital and University of Stellenbosch Tygerberg 7505 South Africa Department of Obstetrics and Gynecology Bronovo Hospital The Hague 2597AX The Netherlands

The measurement or evaluation and clinical significance of human sperm morphology has always been and still is a controversial aspect of the semen analysis for the determination of a male＇s fertility potential. In this review the background of the development of the evaluation criteria for sperm morphology will be discussed. Aspects of criticism on the strict criteria definition and use of the criteria for sperm morphology evaluation will be discussed as well as possible reasons for the decline in normal sperm morphology values and how we can compromise for this phenomenon resulting in the very low normal reference value as published in the 2010 WHO manual for the Examination and Processing of Human Semen. One of the possible solutions may be to give more attention to a limited number of abnormal sperm morphology categories and the inclusion of sperm morphology patterns. It is concluded in this review that if done correctly and with care and with strict application of existing guidelines as outlined in the 2010 WHO manual, sperm morphology measurement still has a very important role to play in the clinical evaluation of male fertility potential.

关键词： human sperm morphology male fertility potential strict criteria traditional or liberal criteria WHO manual for semen analysis

Interpreting Morphologically Homogeneous(Paleo-)Populations as Ecological Species Enables Comparison of Living and Fossil Organism Groups,Exemplified by Nummulitid Foraminifera

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Journal of Earth Science 2022年第6期33卷 1362-1377页

作者： johann Hohenegger Ana Ivis Torres-Silva Wolfgang Eder Institute for Paleontology University of Vienna1090ViennaAustria

Morphologically homogeneous groups,either living populations or fossil paleo-populations,must be regarded as ecological species,independent of their molecular genetic resemblance in living *** is always expressed during development by structure genes initiated from a network of regulator genes acting at different times and intensities,additionally being subjected to epigenetic ***,homogeneous populations influenced by the environment represent species better than the reproduction(biological species)or molecular-genetic approach using ancestral sequences like *** and fossil representatives of nummulitid foraminifera were chosen to demonstrate complete reconstruction of morphology using metrical growth-invariant and growth-independent *** these characters,6 models were established to define ecological species in living and fossil ***,a distinction between evolutionary and environmental effects in fossil forms was possible using discriminant analysis showing characters that are responsible for differentiating between evolutionary and environmental trends.

关键词： ecological species growth-invariant metrical characters morphology homogeneity nummulitids

Single photon emission and recombination dynamics in self-assembled GaN/AlN quantum dots

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Light(Science & Applications) 2022年第5期11卷 751-765页

作者： johann Stachurski Sebastian Tamariz Gordon Callsen Raphaël Butté Nicolas Grandjean Institute of Physics École Polytechnique Fédérale de LausanneEPFLCH-1015 LausanneSwitzerland Present address:UniversitéCôte d’Azur CNRSCRHEAF-06560 ValbonneFrance Present address:Institut für Festkörperphysik Universität Bremen28359 BremenGermany

Ⅲ-nitride quantum dots(QDs)are a promising system actively studied for their ability to maintain single photon emission up to room ***,we report on the evolution of the emission properties of self-assembled GaN/AlN QDs for temperatures ranging from 5 to 300 *** carefully track the photoluminescence of a single QD and measure an optimum single photon purity of g^((2))(0)=0.05±0.02 at 5 K and 0.17±0.08 at 300 *** complement this study with temperature dependent time-resolved photoluminescence measurements(TRPL)performed on a QD ensemble to further investigate the exciton recombination dynamics of such polar zero-dimensional *** comparing our results to past reports,we emphasize the complexity of recombination processes in this *** of the more conventional mono-exponential decay typical of exciton recombination,TRPL transients display a bi-exponential feature with short-and long-lived components that persist in the low excitation *** the temperature insensitivity of the long-lived excitonic component,we first discard the interplay of dark-to-bright state refilling in the exciton recombination ***,this temperature-invariance also highlights the absence of nonradiative exciton recombinations,a likely direct consequence of the strong carrier confinement observed in GaN/AlN QDs up to 300 ***,our results support the viability of these dots as a potential single-photon source for quantum applications at room temperature.

关键词： temperature. process. quantum

Low-complexity online correction and calibration of pedestrian dead reckoning using map matching and GPS

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Geo-Spatial Information Science 2019年第2期22卷 114-127,I0004页

作者： Fabian Hölzke johann-P.Wolff Frank Golatowski Christian Haubelt Institute of Applied Microelectronics and CE University of RostockRostockGermany

Dead Reckoning is a relative positioning scheme that is used to infer the change of position relative to a point of origin by measuring the traveled distance and orientation *** Dead Reckoning(PDR)applies this concept to walking *** method can be used to track someone's movement in a building after a known landmark like the building's entrance is ***,the movement of a foot and the corresponding direction change is measured and summed up,to infer the current *** and integrating the corresponding physical parameters,*** inertial sensors,introduces small errors that accumulate quickly into large distance *** of a buildings geography may reduce these errors as it can be used to keep the estimated position from moving through walls and onto likely *** this paper,we use building maps to improve localization based on a single foot-mounted inertial *** describe our localization method using zero velocity updates to accurately compute the length of individual steps and a Madgwick filter to determine the step *** though the computation of individual steps is quite accurate,small errors still accumulate in the long *** show how correction algorithms using likely and unlikely paths can rectify errors intrinsic to pedestrian dead reckoning tasks,such as orientation and displacement drift,and discuss restrictions and disadvantages of these *** also present a method of deriving the initial position and orientation from GPS *** verify our PDR correction methods analyzing the corrected and raw trajectories of six participants walking four routes of varying length and complexity through an office building,walking each route three *** quantitative results show an endpoint accuracy improvement of up to 60%when using likely paths and 23%when using unlikely ***,both approaches can also decrease accuracy in certain *** identify those scenarios and

关键词： Indoor localization Pedestrian Dead Reckoning(PDR) Inertial Navigation System(INS) map matching Zero Velocity Update(ZUPT)

A vestigial pathway for sex differences in immune regulation

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Cellular & Molecular Immunology 2017年第7期14卷 578-580页

作者： Yun Liang J Michelle Kahlenberg johann E Gudjonsson Department of Dermatology University of MichiganAnn ArborMI 48109USA Division of Rheumatology Department of Internal MedicineUniversity of MichiganAnn ArborMI 48109USA

Autoimmune diseases have a strikingly higher prevalence in women compared to men,with approximately 80%of individuals affected with autoimmune diseases being *** nature of this sex-bias has remained unclear,but sex hormones have previously been implicated as the leading underlying *** this research highlight,we discuss a recently identified transcription factor。

关键词： diseases autoimmune prevalence