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On the Contribution of Wu Wen-Tsün to Algebraic Topology

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Journal of Systems Science & Complexity 2019年第1期32卷 3-36页

作者： BRASSELET jean-paul I2M (CNRS)-Aix-Marseille University

The aim of this article is to present the contribution of Wu Wen-Tsün to Algebraic Topology and more precisely to the theory of characteristic classes. Several papers provide complete and welldocumented biography and academic career of Wu Wen-Tsün, in particular, Hudecek, 2014; O'Connor and Robertson, 2006; Wen-Tsün Wu's Academic Career, 2006; Selected works of Wen-Tsun Wu, *** author does not repeat the details provided in these papers concerning the Wu Wen-Tsün's bibliography, we will just mention people involved in the Wu Wen-Tsün's period in *** addition to Wu Wen-Tsün's papers, the Dieudonné's book(Dieudonné, 1960) provides an excellent presentation of main results of Wu Wen-Tsün in Algebraic and Differential Topology. The author will use and abuse of this book(and refer to) when *** the introduction, the author recalls mainly historical facts concerning the contribution of Wu Wen-Tsün to Algebraic Topology. The second section shows speci?cally the contribution of Wu WenTsün to the Stiefel-Whitney classes and introduces the third section, dealing with the(real) Wu *** author provides de?nition, properties as well as further developments and generalizations of the Wu classes. The fourth and ?fth sections are devoted to recent applications: In Cobordism theory and in Mathematical Physics. The author notices that Wu classes have been used as well in other domains,in particular surgery theory(Madsen and Milgram, 1979). The last section concerns the complex Wu classes and shows that the more recent Mather classes coincide with the previously de?ned complex Wu classes, that is a result from Zhou(1994)(see also Liu, 1996).This article is devoted to the contribution of Wu Wen-Tsün to the theory of Characteristic Classes,which coincides with his "French period"(1947–1951). However, speaking of Algebraic Topology, it is worthwhile to mention the important contribution of Wu Wen-Tsün to the Theory of realization of complexes or manifolds in Eucl

关键词： Algebraic topology characteristic class cobordism theory mathematical physics Wu Class

Geochemical characterization of the metasedimentary rocks of the Yaounde Group within the southernmost North Equatorial tectonic belt:insights into geodynamic evolution

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Acta Geochimica 2023年第6期42卷 1017-1034页

作者： Simon Pierre Mbola Ndzana Moise Christian Balla Ateba Germain Marie Monespérance Mboudou Moussa Nsangou Ngapna jean paul Sep Nlongang Solange Ipan Moise Bessong jean Bosco Olinga Joseph Mvondo Ondoa Sébastien Owona paul Bilong Department of Earth Sciences Faculty of ScienceUniversity of YaoundéIP.O.Box:812Yaounde´Cameroon Institute for Geological and Mining Research P.O.Box:4110NlongkakYaounde´Cameroon Department of Earth Sciences Faculty of ScienceUniversity of DoualaP.O.Box:24157DoualaCameroon Department of Geology Faculty of ScienceThe University of BueaP.O.Box:67BueaCameroon

The Proterozoic metasedimentary rocks of the Yaounde Group on the northern edge of the Congo Shield in Central Africa were investigated to understand their provenance and depositional ***,geochemistry,and field evidence helped to subdivide the metasediments into paragneiss,mica schist,chlorite schist,and quartzite which were derived from greywacke,shale,quartz arenite,litharenite *** are immature with some mature samples,moderately weathered and reworked Neo-and Post-Archean *** earth element signatures(Chondrite Eu/Eu^(*)≤1),enrichment of light rare earth elements over the heavy ones,and the La/Sc ratio(>0.7)are compatible with those of the intermediate and felsic sources from the upper continental *** metasediments were deposited in the continental arc setting and have evolved during Proterozoic times according to the Wilson cycle to form the West Gondwana including NE Brazil.

关键词： West Gondwana North Equatorial orogenic belt Yaounde Group Neoproterozoic basin Geochemistry of metasedimentary rocks Geodynamic evolution

Association between the Different Phenotypes of Polycystic Ovary Syndrome and the Outcome in in Vitro Fertilization at Human Reproductive Center paul et Chantal Biya-Yaoundé

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Open Journal of Obstetrics and Gynecology 2024年第1期14卷 18-28页

作者： Ngono Akam Vanina Ngah Minala Belinga Etienne Belinga Etienne Mpono Pascale Nyada Serges Onana Y. Kasia Cho Joselyne Kasia Florence Adjessa Abega Kasia jean Marie Gynaecological Endoscopic Surgery and Human Reproductive Teaching Hospital Yaoundé Cameroon Department of Gynecology and Obstetrics Faculty of Medicine and Biomedical Sciences University of Yaoundé 1 Yaoundé Cameroon

Background: In Vitro Fertilization/Intracytoplasmic Sperm Injection (IVF/ICSI) represents the final step in the management of Polycystic Ovarian Syndrome (PCOS). Our objective was to study the association between PCOS phenotypes and IVF/ICSI results in women admitted to Gynaecological Endoscopic Surgery and Human Reproductive Teaching Hospital (CHRACERH). Material and Method: We carried out a cohort study with historical-prospective data collection over a period of seven years (January 2016 to March 2023) at Chracerh. PCOS patients were subdivided into 4 subgroups A, B, C and D. Results: We recruited 128 patients including 64 PCOS patients divided into four phenotypes and 64 non-PCOS patients constituting the control group. Phenotype D without hyperandrogenism had used the lowest dose of gonadotropins, i.e. 1939.7 ± 454.3 IU, and had produced a greater quantity of estradiol on the day ovulation was triggered (6529.8 ± 4324.8 ng/ml). The average number of punctured follicles and mature oocytes were higher in the phenotype D group. Ovarian hyperstimulation syndrome (OHSS) occurred mainly in phenotype D (3/35), with an estimated prevalence of 2.3%. The fertilization rate seemed lower in the hyperandrogenic phenotypes A, B, C compared to the group without hyperandrogenism without significant difference (p = 0.461). The biological pregnancy rate and live birth rate were comparable between the different groups. Conclusion: Phenotype D used less dose of gonadotropins. Biological pregnancy and live birth rates were comparable between the different phenotypes.

关键词： Phenotype Polycystic Ovarian Syndrome IVF/ICSI Prognosis CHRACERH

Petrogenesis, LA-ICP-MS zircon U-Pb geochronology and geodynamic implications of the Kribi metavolcanic rocks,Nyong Group, Congo craton

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Acta Geochimica 2022年第3期41卷 470-495页

作者： Hermine Mvodo Sylvestre Ganno Gus Djibril Kouankap Nono Donald Hermann Fossi Philomene Estelle Nga Essomba Marvine Nzepang Tankwa jean paul Nzenti Department of Earth Sciences University of YaoundéIP.O.Box 812YaoundeCameroon Department of Geology HTTCUniversity of BamendaP.O.Box 39BambiliBamendaCameroon Institute for Geological and Mining Research P.O.Box 4110YaoundéCameroon Faculty of Mines and Petroleum Industries University of MarouaKaélé08MarouaCameroon

Metavolcanic rocks are well-exposed in the Kribi area within the Nyong Group, Congo craton, but their origin, age, and tectonic significance are poorly *** we report integrated field mapping and petrography,geochemistry, and LA-ICP-MS zircon U-Pb ages of these metavolcanic rocks to constrain their petrogenesis and geodynamic implications. The studied rocks consist of mafic granulite, garnet-amphibole gneiss, and garnet-biotite gneiss, and occur interbanded with sharp contact and intruded by syenite dyke. These metavolcanic rocks are classified as MORB-like tholeiitic to calc-alkaline basalts,basaltic andesite, and rhyodacite rocks with within-plate setting geochemical signatures. The metabasite rocks(basalt to basaltic andesite protolith) are likely the equivalent of a spinel peridotite product representing ~ 2–5 %partial melting of metasomatized mantle source, while the metarhyodacite rocks are derived from the fractional crystallization of the same parental magma. Zircon U-Pb data revealed that the rhyodacite rocks initially formed at2671 ± 51 Ma and underwent later metamorphism at2065 ± 55 Ma. The Neoarchean protolith age is comparable to the ca. 2628 Ma tholeiitic magmatism and ca.2666 Ma high-K granites, suggesting bimodal Neoarchean magmatic event within the Ntem Complex, while the metamorphic ages fall within the ca. 2100–2000 Ma highgrade tectono-metamorphic event attributed to Eburnean/Trans-Amazonian orogeny. At the regional scale,metavolcanic rocks with similar origins and ages are documented in the Sa o Francisco Craton in Brazil, suggesting comparable geodynamic evolution on both sides of the south Atlantic during the Paleoproterozoic.

关键词： Metavolcanic rocks MORB Within plate volcanic zone Mantle source Fractional crystallization Congo craton Cameroon

Microbiota-host interplay at the gut epithelial level,health and nutrition

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Journal of Animal Science and Biotechnology 2017年第2期8卷 327-334页

作者： jean-paul Lallès Division of Human Nutrition Division INRA Clermont-Ferrand France Human Nutrition Research Center-West Nantes France

Growing evidence suggests the implication of the gut microbiota in various facets of health and disease. In this review, the focus is put on microbiota-host molecular cross-talk at the gut epithelial level with special emphasis on two defense systems： intestinal alkaline phosphatase（IAP） and inducible heat shock proteins（iHSPs）. Both IAP and iHSPs are induced by various microbial structural components（e.g. lipopolysaccharide, flagellin, CpG DNA motifs）,metabolites（e.g. n-butyrate） or secreted signal molecules（e.g., toxins, various peptides, polyphosphate）. IAP is produced in the small intestine and secreted into the lumen and in the interior milieu. It detoxifies microbial components by dephosphorylation and, therefore, down-regulates microbe-induced inflammation mainly by inhibiting NF-κB pro-inflammatory pathway in enterocytes. IAP gene expression and enzyme activity are influenced by the gut microbiota. Conversely, IAP controls gut microbiota composition both directly, and indirectly though the detoxification of pro-inflammatory free luminal adenosine triphosphate and inflammation inhibition. Inducible HSPs are expressed by gut epithelial cells in proportion to the microbial load along the gastro-intestinal tract. They are also induced by various microbial components, metabolites and secreted molecules. Whether iHSPs contribute to shape the gut microbiota is presently unknown. Both systems display strong anti-inflammatory and anti-oxidant properties that are protective to the gut and the host. Importantly, epithelial gene expressions and protein concentrations of IAP and iHSPs can be stimulated by probiotics, prebiotics and a large variety of dietary components, including macronutrients（protein and amino acids, especially L-glutamine, fat, fiber）, and specific minerals（e.g. calcium）and vitamins（e.g. vitamins K1 and K2）. Some food components（e.g. lectins, soybean proteins, various polyphenols） may inhibit or disturb these systems. The general cel ular and molecula

关键词： Diet Gut Inducible heat shock protein Inflammation Intestinal alkaline phosphatase Microbiota

Single-particle cryo-EM: beyond the resolution

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National Science Review 2019年第5期6卷 864-866页

作者： jean-paul Armache Yifan Cheng Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences Pennsylvania State University Howard Hughes Medical Institute University of California San Francisco Department of Biochemistry and Biophysics University of California San Francisco

Structural biology aims to provide structural insights into our understandings of biological processes at the atomic *** structures of biological macromolecules are often determinedby one of the three major methods:Xr... 详细信息

关键词： Single-particle cryo-EM beyond the resolution

Expert group syndrome at high altitude

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Sports Medicine and Health Science 2022年第3期4卷 215-218页

作者： jean-paul Richalet Marie-Anne Magnan Alice Gavet Pierre Lafère UniversitéSorbonne Paris Nord Laboratoire Hypoxie et PoumonUMR INSERM U1272BobignyFrance Institut National des Sports de l’Expertise et de la PerformancePôle médicalParisFrance Hôpitaux universitaires de Genève Département de médecine aiguëUnitéde médecine subaquatique et hyperbareGenevaSwitzerland Hôpitaux du Mont-Blanc Soins de suite et réadaptationChamonixFrance Universitéde Bretagne Occidentale Laboratoire ORPHYEA 44324BrestFrance HauteÉcole Bruxelles-Brabant(HE2B) EnvironmentalOccupationalAgeing(Integrative)Physiology LaboratoryBrusselsBelgium

During a training session for the university diploma of Mountain medicine delivered by University Sorbonne Paris Nord for medical doctors,one of the participants developed signs of maladaptation to high altitude at 3600 m,the severity of which was incorrectly *** was sparingly given by the patient(an anesthetist)to several of his colleagues and no one was in charge to collect clinical data,take a history,and provide appropriate *** combination of the absence of designation of a supervising doctor and the difficulty of communicating with the patient led to a lack of coordinated management and to an evolution of the symptoms towards severe acute mountain ***,the very rapid management of the patient and a rapid helicopter evacuation,as soon as the symptoms worsened towards the onset of a suspected high altitude cerebral and/or pulmonary edema,allowed rapid resolution without ***,medical,psychological,and managerial factors led to this Expert Group Syndrome.

关键词： Acute mountain sickness High altitude cerebral edema Psychology Group management

Gn filling orbicular N-sided holes using periodic B-spline surfaces

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Science China(Information Sciences) 2011年第7期54卷 1383-1394页

作者： paul jean-Claude Tsinghua National Laboratory for Information Science and Technology Institute National de Recherche en Informatique et en Automatique School of Software Tsinghua University Key Laboratory for Information System Security Ministry of Education of China

The orbicular N -sided hole filling problem is usually introduced by filleting an end-point of a part with large *** existing methods based on quadrilateral partition or constrained-optimization can rarely generate high-order continuous blending surfaces under these *** paper first reparameterizes the boundary of the specified orbicular N -sided hole to ensure the compatibility of neighboring cross-boundary derivatives on the connecting points,preserving their G n *** we compute the control points of the periodic B-spline surface using the sufficient G n continuity condition on the pole and the algorithm of extending parametric *** method generates single blending surface,which can be converted into standard Bspline surface by adding knots without introducing *** only elevates the degree of the boundary by *** construction method is simple and efficient,without iteration nor large-scale matrix *** achieves G n continuity under compatible *** blending examples underline its feasibility and practicability.

关键词： CAD periodic B-spline surface polar coordinates N -sided hole filling G n continuity

Geochemistry and zircon U–Pb ages of the Paleoproterozoic ultramafic rocks of the Mbi Valley, Boali area, Central African Republic

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Acta Geochimica 2022年第3期41卷 515-535页

作者： Evine Laure Njiosseu Tanko Prince Emilien Danguene Philomene Nga Essomba Tsoungui Sylvestre Ganno Jonas Didero Takodjou Wambo Bertin Guy Takam Tchoupe Gus Djibril Kouankap Nono Timoleon Ngnotue Boniface Kankeu jean Biandja jean paul Nzenti Department of Earth Sciences University of DschangP.O.Box 67DschangCameroon Department of Earth Sciences University of BanguiP.O.Box 908BanguiCentral African Republic Department of Mining Engineering and Mineral Processing School of Mines and Petroleum IndustriesUniversity of MarouaP.O.Box 08Kaélé-MarouaCameroon Department of Earth Sciences University of YaoundéIP.O.Box 812YaoundéCameroon Department of Geology HTTCUniversity of BamendaP.O.Box 39BambiliBamendaCameroon Institute for Geological and Mining Researches(IGMR) P.O.Box 4110YaoundéCameroon

This paper investigates the geochemistry of bulk rock and infers the petrogenesis of ultramafic rocks in the Boali Precambrian terrane in Mbi Valley,in the North of the Central African Republic(CAR).The studied rocks comprise coarse primary olivine and orthopyroxene relics(dominant phase),magnesio-hornblende,magnetite,and ***-rock analysis indicates low SiO_(2)(average of 43.14 wt%)and high MgO(19.84–26.98 wt%)contents and their Mg number(Mg#)ranges from 74 to ***(526–865 ppm),Cr(1500–3680 ppm)***(Na_(2)O-K_(2)O)-FeO-MgO)and ACM(Al_(2)O_(3)-CaO-MgO)ternary diagrams have revealed that the studied samples correspond to arc-related ultramafic ***-normalized REE plots display an increasing trend from La to Sm(CeN/SmN:0.74–1.81),weak negative to no Eu(Eu/Eu*=0.72–1.05)and strong negative Ce(Ce/Ce*=0.33–0.98)*** mantle normalized of multi-element diagrams exhibit LREE enrichment and large ion lithophile elements(LILE)relative to high field strength elements(HFSE),and notable negative anomalies in *** suggests the generation of the parent melt by slab dehydration and wedge melting *** addition,incompatible trace element composition and ratios assumed that the source magma had an enhanced mantle source associated with a prominent influence of continental *** of mantle wedge by plate-dehydrated,LILE-rich fluids and the incorporation of sediments derived from subduction explain the enhancement of the *** major and trace element compositions jointly with the tectonic reconstruction of this region and LA-ICP-MS U–Pb data on zircon constrain the emplacement age at ca.2099 Ma in a continental margin arc setting involving subduction of an oceanic plate beneath the continental lithosphere,dehydration of the slab and mantle wedge *** result intimate that the remnants of Paleoproterozoic oceanic crust or subduction event and subsequent basins closure extended from

关键词： Atlantic supercontinent Central African Republic Ultramafic cumulate LILE-enriched fluids Arc setting