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Bare-throated spurfowl(Pternistis spp.)males across Africa impress females with bright throat colours during courtship

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Avian Research 2023年第3期14卷 416-424页

作者： johann H.van Niekerk Department of Environmental Sciences College of Agriculture and Environmental SciencesUniversity of South AfricaP.O.Box 392Pretoria0003South Africa

The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract *** the 23 Afrotropical spurfowl species,the bare-throated subgroup includes Yellow-necked Spurfowl(Pternistis leucosceptus),Rednecked Spurfowl(***),Grey-breasted Spurfowl(***) and Swainson’s Spurfowl(***).The rest of the species include fully feathered throated *** colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year’s *** throat(n=836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities,breeding cycles,and environmental *** for Swainson’s Spurfowl male saturation of throat colours correlated with monthly rainfall,which peaks one or two months before egg ***’s Spurfowl peaks during egg ***-necked Spurfowl has the largest bare ***-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat *** such displays occur in feather-throated *** with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated *** Red-necked Spurfowls have significantly larger bare throats than *** primary function of bare throats probably assists in thermoregulation,particularly in arid *** bare throat may have evolved a secondary role in ***-necked,Red-necked,and Greybreasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding *** female throat colours(unsaturated) may discourage male interlopers and predation during egg *** appears to be carotenoid-food *** different colours among the bare-throated species may serve as prezygotic mechani

关键词： Bare-throated spurfowls Breeding Colour saturation Ornaments Pternistis spp. Sexual size dimorphism

Vocal behavior of Crested Guineafowl(Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve,Kwa Zulu-Natal province,South Africa

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Chinese Birds 2015年第3期6卷 132-139页

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

Background:Generally speaking,playbacks were often ineffective to determine the group sizes of birds since mainly males from leks *** limitation has not been tested properly for flocking birds such as Crested Guineafowl(Guttera edouardi) with the view to use it as a counting *** aims of the study reported in this paper were(1) to describe the cal s of Crested Guineafowl in a social context;(2) to interpret cal s in an evolutionary context;and(3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in smal isolated ***:The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve(Kwa Zulu-Natal,South Africa) from November 2010 to June *** line observations and sound playback methods were ***:The behavioral context and structure of cal s were *** eight cal s described for Crested Guineafowl were produced mainly to unite flock members in the dense understory,where visibility was poor,and to repel *** not disturbed,Crested Guineafowl were quiet and only made soft contact ***:The high rate of call back and the fact that flocks invariably approach the source of the call en masse,shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a *** value of playbacks as a conservation tool is assessed.

关键词： Guttera edouardi Playback Calls Social behavior Flocking Transect surveys

Orange River Francolins(Scleroptila levaillantoides)persist in fragmented Highveld farming landscapes,South Africa

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Avian Research 2017年第2期8卷 83-90页

作者： johann H.van Niekerk Department of Environmental Sciences College of Agriculture and Environmental ScienceUniversity of South AfricaPO Box 392Pretoria 0003South Africa

Background:How do Orange River Francolins(Scleroptila levaillantoides) adapt to an intensive farming landscape with grass(grazing) camps and crop cultivation? To answer this question, a study was carried out in south-east of johannesburg in South Africa to clarify the interaction of francolins with a landscape consisting of land use ***:A transect-road of 45 km was traversed weekly during November 2015–October 2016 through flat maize(Zea mays) and cattle(Bos primigenius) grazing fields. Francolins were counted in three land use mosaic types along the transect-road(including the road):grass camps on both sides of the road(grass/grass edges); arable fields on both sides(arable/arable edges) and arable land on one side with grass camps on the opposite side of the road(arable/grass edges).Results:Francolins used all three mosaic types, but the arable/arable edges were least frequented. Nonetheless, the arable/arable edges played an important part:francolins, including females with chicks, moved along the arable/arable edges, which enabled contact between sub-populations, and the arable/arable edges provided temporary cover(e.g. stubble and maize plants) and ploughed firebreaks to forage(e.g. for bulbs).Conclusion:Cultivation of crop within grasslands does not constrain breeding, movement and habitat use by the Orange River Francolin. For conservation purposes it is critical that the fine-scale mosaic of grazing and cultivation areas remain intact.

关键词： Agriculture Edge habitat Management Mosaics Orange River Francolin Scleroptila levaillantoides

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

On the structure in the ΛN cross section at the ∑N threshold

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Chinese Physics C 2021年第9期45卷 157-166页

作者： johann Haidenbauer Uf-G.MeiBner Institute for Advanced Simulation Institut fur Kemphysik and Julich Center for Hadron PhysicsForschungszentrum JulichD-52425 JulichGermany Helmholtz-Institut fiir Strahlen-und Kemphysik and Bethe Center for Theoretical Physics Universitat Bonn53115 BonnGermany Tbilisi State University 0186 TbilisiGeorgia

The complexity of threshold phenomena is exemplified on a prominent and long-known case-the structure in theΛp cross section(invariant mass spectrum)at the opening of the∑N *** mass splitting between the∑baryons together with the angular momentum coupling in the^(3)S_(1)-^(3)D_(1)partial wave imply that,in principle,up to six channels are *** hyperon-nucleon potentials that provide an excellent description of the available low-energy Λp and∑N scattering data,the shape of the resulting Λp cross section is discussed and the poles near the ∑N threshold are *** for a strangeness S=-1 dibaryon is provided,in the form of a(unstable)∑N bound state in the vicinity of the ∑N *** for level shifts and widths of ∑^(-)p atomic states are given.

关键词： hyperon-nucleon interaction dibaryon threshold effects

Targeting leukemic fusion proteins with small interfering RNAs:recent advances and therapeutic potentials

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Acta Pharmacologica Sinica 2006年第3期27卷 273-281页

作者： Maria THOMAS johann GREIL Olaf HEIDENREICH Department of Molecular Biology Interfaculty Institute for Cell BiologyEberhard Karls University TuebingenAuf der Morgenstelle 1572076 TuebingenGermany Paediatric University Hospital Im Neuenheimer Feld 15369120 HeidelbergGermany

RNA interference has become an indispensable research tool to study gene func-tions in a wide variety of *** of their high efficacy and specificity,RNA interference-based approaches may also translate into new therapeutic stra-tegies to treat human *** particular,oncogenes such as leukemic fusionproteins,which arise from chromosomal translocations,are promising targets forsuch gene silencing approaches,because they are exclusively expressed in pre-cancerous and cancerous tissues,and because they are frequently indispensablefor maintaining the malignant *** review summarizes recent deve-lopments in targeting leukemia-specific genes and discusses problems andapproaches for possible clinical applications.

关键词： small interfering RNA small hairpin RNA RNA interference leukemic fusion genes leukemia

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

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

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