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Chemical-Abrasion U-Pb zircon geochronology reveals 150 Myr of partial melting events in the Archean crust of the São Francisco Craton

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Geoscience Frontiers 2022年第5期13卷 169-189页

作者： Lorena Martins Cristiano Lana Ariela Mazoz Tiago Novo Applied Isotope Research Group Departamento de GeologiaEscola de MinasUniversidade Federal de Ouro PretoMorro do CruzeiroOuro PretoMG35400-000Brazil Universidade Federal de minas Gerais Programa de Pós-Graduação em GeologiaIGC-CPMTCCampus PampulhaAv.Antônio Carlos 6627Belo HorizonteMG31270-901Brazil

Field observations and CA-LA-ICP-MS U–Pb zircon ages and Hf isotope compositions obtained from migmatitic orthogneisses and granitoids from the Belo Horizonte Complex,southern São Francisco Craton,indicate a major period of partial melting and production of felsic rocks in the *** observations show that the complex is an important site for studying partial melting processes of Archean crystalline *** of the complex exposes fine-grained stromatic migmatites that are intruded by multiple leucogranitic veins and sheeted *** migmatites and leucogranite sheets are crosscut by several phases of granitoid batholiths and small granitic bodies;both of which are closely associated with the host banded *** abrasion followed by detailed cathodoluminescence imaging revealed a wide variety of zircon textures that are consistent with a long-lived period of partial melting and crustal *** of U-Pb and Hf isotopes disclose the complex as part of a much wider crustal segment,encompassing the entire southern part of the São Francisco *** of available U-Pb ages suggests that this crustal segment was consolidated sometime between 3000 Ma and 2900 Ma and that it experienced three main episodes of partial melting before stabilization at 2600 *** partial melting episodes took place between 2750 Ma and 2600 Ma as a result of tectonic accretion and peeling off the lithospheric mantle and lower *** process is likely responsible for the emplacement of voluminous potassic granitoids across the entire São Francisco *** believe that the partial melting of Meso-Archean crystalline crust and production of potassic granitoids are linked to a fundamental shift in the tectonics of the craton,which was also responsible for the widespread intrusion of large syenitic bodies in the northern part of the craton,and the construction of layered mafic–ultramafic intrusions to the south of the BHC.

关键词： Archean São Francisco Craton Crustal reworking U-Pb geochronology Lu-Hf isotopes

Buzz-pollination in Neotropical bees:genus-dependent frequencies and lack of optimal frequency for pollen release

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Insect Science 2020年第1期27卷 133-142页

作者： Conrado Augusto Rosi-denadai Priscila Cassia Souza Araujo Lucio Antonio de Oliveira Campos Lirio Cosme Jr. Raul Narciso Carvalho Guedes departamento de Entomologia Universidade Federal de VigosaVigosaMinas GeraisBrazil departamento de Biologia Geral Universidade Federal de VigosaVigosaMinas GeraisBrazil

Over 50 genera of bees release pollen from flower anthers using thoracic vibrations,a phenomenon known as *** efficiency of this process is directly affected by the mechanical properties of the buzzes,namely the duration,amplitude,and ***,although the effects of the former two properties are well described,the role of buzz frequency on pollen release remains ***,nearly all of the existing studies describing vibrational properties of natural buzz-pollination are limited to bumblebees(Bombus)and carpenter bees(Xvlocopa)constraining our current understanding of this behavior and its ***,we attempted to minimize this shortcoming by testing whether flower anthers exhibit optimal frequency for pollen release and whether bees tune their buzzes to match these(optimal)*** true,certain frequencies will trigger more pollen release and lighter bees will reach buzz frequencies closer to this optimum to compensate their smaller buzz *** strategies were used to test these hypotheses:(i)the use of(artificial)vibrational playbacks in a broad range of buzz frequencies and amplitudes to assess pollen release by tomato plants(Solarium Ivcopersicum L.)and(ii)the recording of natural buzzes of Neotropical bees visiting tomato plants during *** playback experiment indicates that although buzz frequency does affect pollen release,no optimal frequency exists for *** addition,the recorded results of natural buzz-pollination reveal that buzz frequencies vary with bee genera and are not correlated with body ***,neither bees nor plants are tuned to optimal pollen release *** frequency of buzz-pollination is a likely consequence of the insect flight machinery adapted to reach higher accelerations,while flower plant response to buzz-pollination is the likely result of its pollen granular properties.

关键词： buzz amplitude buzz frequency floral sonication pollination stingless bees vibration

Proto-Adamastor ocean crust(920 Ma)described in Brasiliano Orogen from coetaneous zircon and tourmaline

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Geoscience Frontiers 2019年第4期10卷 1623-1633页

作者： Léo A.Hartmann Mariana Werle Cassiana R.L. Michelin Cristiano Lana Gláucia N. Queiroga Marco P. Castro Karine R. Arena Instituto de Geociências Universidade Federal do Rio Grande do SulAvenida Bento Goncalves950091501-970Porto AlegreRio Grande do SulBrazil departamento de geologia Escola de MinasUniversidade Federal de Ouro PretoMorro do Cruzeiro35400-000Ouro PretoMinas GeraisBrazil

Proto-Adamastor ocean bathed Rodinia and successor continental fragments from 1.0-0.9 Ga up to0.75 Ga,and evolved into world Adamastor Ocean at 0.75-0.60 *** oceanic crust is poorly preserved on continents,only indirect evidence registered in Brasiliano *** report first evidence of ophiolite originated in *** use multi-technique U-Pb-Hf zircon andδ^11B tourmaline isotopic and elemental *** host tourmalinite is enclosed in metaserpentinite,both belonging to the Bossoroca *** is 920 Ma-old,εHf(920 Ma)=+12,HfTDM=1.0 Ga and has’oceanic’composition(e.g.,U/Yb<0.1).Tourmaline is dravite withδ^11B=+1.8‰(Tur 1),0‰(Tur 2),-8.5‰(Tur 3).These characteristics are a novel contribution to Rodinia and associated world ocean,because a fragment of proto-Adamastor oceanic crust and mantle evolved at the beginning of the Brasiliano Orogen.

关键词： Coeval zircon and tourmaline Bossoroca ophiolite Early Brasiliano Orogen Zircon U-Pb-Hf isotopes Zircon trace elements Tourmaline boron isotopes

An exotic Cretaceous kimberlite linked to metasomatized lithospheric mantle beneath the southwestern margin of the S?o Francisco Craton,Brazil

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Geoscience Frontiers 2022年第1期13卷 182-203页

作者： Luísa D.V.Carvalho Tiago Jalowitzki Ricardo Scholz Guilherme O.Gonçalves Marcelo Peres Rocha Rogério Silvestre Pereira Cristiano Lana Marco Paulo de Castro Gláucia Queiroga Reinhardt A.Fuck Universidade Federal de Ouro Preto(UFOP) Escola de MinasDepartamento de GeologiaCampus Morro do Cruzeiro35400-000 Ouro PretoMGBrazil Universidade de Brasília(UnB) Instituto de GeociênciasCampus Universitário Darcy Ribeiro70910-900 BrasíliaDFBrazil Independent Geologist Consultant

We present major and trace element compositions of mineral concentrates comprising garnet xenocrysts,ilmenite,phlogopite,spinel,zircon,and uncommon minerals(titanite,calzirtite,anatase,baddeleyite and pyrochlore)of a newly discovered Late Cretaceous kimberlite(U-Pb zircon age 90.0±1.3 Ma;2σ)named Osvaldo Franca 1,located in the Alto Paranaíba Igneous Province(APIP),southeastern *** grains are lherzolitic(Lherz-1,Lherz-2 and Lherz-3),harzburgitic(Harz-3)and wehrlitic(Wehr-2).The pyrope xenocrysts cover a wide mantle column in the subcratonic lithosphere(66–143 km;20–43 kbar)at relatively low temperatures(811–875°C).The shallowest part of this mantle is represented by Lherz-1 pyropes(20–32 kbar),which have low-Cr(Cr_(2)O_(3)=1.74–6.89 wt.%)and fractionated middle to heavy rare earth elements(MREE-HREE)*** deepest samples are represented by Lherz-2,Lherz-3,Harz-3,and Wehr-2 pyropes(36–43 kbar).They contain high-Cr contents(Cr_(2)O_(3)=7.36–11.19 wt.%)and are characterized by sinusoidal(Lherz-2 and Wehr-2)and spoon-like(Lherz-3 and Harz-3)REE *** to their REE and trace elements,pyrope xenocrysts have enriched nature(e.g.,Ce and Yb ***_(2)O_(3)),indicating that the cratonic lithosphere has been affected by a silicate melt with subalkaline/tholeiite composition due to their low Zr,Ti and Y *** minerals with typical kimberlitic signatures,such as ilmenite and zircon,the exotic compositions of phlogopite and ulvöspinel suggest an enriched component in the magma *** formation of rare mineral phases with strong enrichment of light-REE(LREE)and high field strength elements(HFSE)is attributed to the late-stage kimberlitic *** propose a tectonic model where a thermal anomaly,represented by the low-velocity seismic anomaly observed in P-wave seismic tomography images,supplied heat to activate the alkaline magmatism from a metasomatized cratonic mantle source during the late-stages of Gondwana fragmentation and conse

关键词： Osvaldo França 1 kimberlite Alto Paranaíba Igneous Province Metasomatized cratonic lithosphere Zircon U-Pb geochronology

Natural Mg silicates with different structures and morphologies: Reaction with K to produce K2MgSiO4 catalyst for biodiesel production

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International Journal of Minerals,Metallurgy and Materials 2020年第1期27卷 46-54页

作者： Fabiane Carvalho Ballotin Mayra Nascimento Sara Silveira Vieira Alexandre Carvalho Bertoli Ottávio Carmignano Ana Paula de Carvalho Teixeira Rochel Montero Lago departamento de Química Universidade Federal de Minas GeraisBelo HorizonteBrasil Doutorado Inovação/Mineradora Pedras Congonhas Universidade Federal de Minas Gerais31270-901 Belo Horizonte-MGBrazil

In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile(which have the same general formula Mg3Si2O5(OH)4), and talc(Mg3Si4O10(OH)2) were reacted with KOH to prepare catalysts for biodiesel production. Simple impregnation with 20 wt% K and treatment at 700–900°C led to a solid-state reaction to mainly form the K2MgSiO4 phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K2MgSiO4 formation. All the materials showed catalytic activity for the transesterification of soybean oil(1:6 of oil : methanol molar ratio, 5 wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K2MgSiO4.

关键词： silicate serpentinite lizardite antigorite talc chrysotile biodiesel

cAMP:A second messenger involved in the mechanism of midgut alkalinization in Lutzomyia longipalpis

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Insect Science 2022年第4期29卷 1059-1070页

作者： denise Barguil Nepomuceno Grasielle Caldas D’Ávila Pessoa Leonardo Barbosa Koerich Marcos Horácio Pereira Mauricio Roberto Viana Sant'Anna Ricardo Nascimento Araújo Nelder Figueiredo Gontijo Laboratório de Fisiologia de Insetos Hematófagos Departamento de Parasitologia/ICBUniversidade Federal de Minas GeraisBelo HorizonteMGBrazil

The sand fly Lutzomyia longipalpis is the main vector of Leishmania infantum in the *** sand flies ingest sugar-rich solutions and blood,which are digested in the *** of nutrients is an essential function performed by digestive enzymes,which require appropriate physiological *** of the main aspects that influence enzymatic activity is the gut pH,which must be tightly *** second messengers are frequently involved in the coordination of tightly regulated physiological events,we investigated if the second messenger cAMP would participate in the process of alkalinization in the abdominal midgut of female *** midguts containing the indicator dye bromothymol-blue,cAMP stimulated the alkalinization of the midgut *** another technique based on the use of fluorescein as a pH indicator,we propose that cAMP is involved in the alkalinization of the midgut by activating HCO3-transport from the enterocyte's cytoplasm to the *** results strongly suggested that the carrier responsible for this process would be a HCO3−/Cl−antiporter located in the enterocytes’apical *** promotes the release of alkalinizing hormones in the hemolymph;however,when the enzyme adenylyl cyclase,responsible for cAMP production,was inhibited,we observed that the hemolymph from blood-fed ***’females did not stimulate midgut *** result indicated that hormone-stimulated alkalinization is mediated by *** the present study,we provide evidences that cAMP has a key role in the control of intestinal pH.

关键词： abdominal midgut alkalinization cAMP HCO_(3)^(-)/Cl^(-)antiport hormone Lulcomyia longipalpis

Using dung beetles to evaluate the effects of urbanization on Atlantic Forest biodiversity

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Insect Science 2013年第3期20卷 393-406页

作者： Vanesca Korasaki Jose Lopes George Gardner Brown Julio Louzada departamento de Agronomia departamento de Biologia Animal e Vegetal Universidade Estadual de Londrina Londrina-PR Empresa Brasileira de Pesquisa Agropecu~ria Embrapa Florestas Colombo-PR departamento de Biologia Setor de Ecologia Universidade Federal de Lavras Lavras Minas Gerais Brazil

We used dung beetles to evaluate the impact of urbanization on insect biodi- versity in three Atlantic Forest fragments in Londrina, Parana, Brazil. This study provides the first empirical evidence of the impact of urbanization on richness, abundance, compo- sition and guild structure of dung beetle communities from the Brazilian Atlantic Forest. We evaluated the community aspects （abundance, richness, composition and food guilds） of dung beetles in fragments with different degrees of immersion in the urban matrix using pitfall traps with four alternative baits （rotten meat, rotten fish, pig dung and decaying ba- nana）. A total of 1 719 individuals were collected, belonging to 29 species from 11 genera and six Scarabaeinae tribes. The most urban-immersed fragment showed a higher species dominance and the beetle community captured on dung presented the greatest evenness. The beetle communities were distinct with respect to the fragments and feeding habits. Except for the dung beetle assemblage in the most urbanized forest fragment, all others exhibited contrasting differences in species composition attracted to each bait type. Our results clearly show that the degree of urbanization affects Atlantic Forest dung beetle communities and that the preservation of forest fragments inside the cities, even small ones, can provide refuges for Scarabaeinae.

关键词： bioindicator coprophagous beetles food preference fragmentation habitat loss urban matrix

Diversity of the endophytic filamentous fungal leaf community at different development stages of eucalyptus

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Journal of Forestry Research 2019年第3期30卷 1093-1103页

作者： Paulo Sergio Balbino Miguel Fabio Balbino Miguel Bruno Coutinho Moreira Marcelo Nagem Valerio de Oliveira Julio Cesar delvaux Fernanda de Souza Freitas Arnaldo Chaer Borges Maurcio Dutra Costa departamento de Medicina e Enfermagem Universidade Federal de VicosaVicosaMinas Gerais 36570-000Brazil departamento de Quimica Universidade Federal de Juiz de ForaJuiz de ForaMinas Gerais 36036-300Brazil Colegiado de Engenharia Agronomica Universidade Federal do Vale do Sao FranciscoPetrolinaPernambuco 56300-990 Brazil departamento de Ciencias Basicas da Vida Campus Governador Valadares Universidade Federal de Juiz de Fora Governador ValadaresMinas Gerais 35012-140Brazil Coordenacao Geral de Ensino Pesquisa e Extensao Instituto Federal do Triangulo MineiroItuiutabaMinas Gerais 38035-200Brazil departamento de Microbiologia Instituto de Biotecnologia Aplicada aAgropecuariaUniversidade Federal de Vicosa VicosaMinas Gerais 36570-000Brazil

Fungal endophytic species inhabiting the leaves of eucalypts are capable of utilising leaf sugars and can influence both plant growth and health. Endophytic fungal symbionts can use simple soluble sugars in leaves as their main carbon source. This study set out to determine the diversity and distribution of the endophytic filamentous fungal leaf community in the hybrid Eucalyptus urograndis due to its economic importance. The fungal leaf community was characterised using denaturing gradient electrophoresis (DGGE) and correlated with levels of leaf nutrients and sugars throughout plant development. Sequencing of DGGE bands revealed the presence of Basidiomycota and Ascomycota phyla. Fourteen species and three genera of filamentous fungi were identified, and the population structure was affected by the plant developmental stage. Levels of K, Cu, N and Mn influenced communities from the clonal garden, whereas leaves in the field had higher glucose, fructose and sucrose. Many fungi were found to be specific to a certain development stages: Diplomitoporus crustulinus, Podosphaera tridactyla and Aspergillus restrictus to the clonal garden stage;Chaetomella acutiseta and Ascotricha chartarum to the shading stage;Erratomyces patelii and Saxomyces sp. to the shading output stage;Lepidostroma sp. and Saxomyces sp. to the dispatch stage;and Mycosphaerella populicola to the field stage. Teratosphaeria toledana and Teratosphaeria acidotherma were found at more than one developmental stage. Cladosporium sp. and Rhodosporidium fluviale colonized and persisted in plants at the dispatch and field stages. This is the first report of P. tridactyla, A. restrictus, E. patelii, Saxomyces and Lepidostroma sp. as endophytes in eucalipt.

关键词： Diversity 18S rRNA denaturing gradient electrophoresis(DGGE) Sequencing

High-pressure metamorphic rocks in the Borborema Province, Northeast Brazil: Reworking of Archean oceanic crust during proterozoic orogenies

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Geoscience Frontiers 2020年第6期11卷 2221-2242页

作者： Alanielson da Câmara Dantas Ferreira Elton Luiz Dantas Ticiano JoséSaraiva dos Santos Reinhardt A.Fuck Mahyra Tedeschi Instituto de Geociências Universidade de Brasília(UnB)70910-900Brasília-DFBrazil Instituto de Geociências Universidade Estadual de Campinas(UNICAMP)Departamento de Geologia e Recursos Naturais13083-970Campinas-SPBrazil Instituto de Geoci^encias Universidade Federal de Minas Gerais(UFMG)31270-901Belo HorizonteMGBrazil

We present the first evidence of Archean oceanic crust submitted to Proterozoic high-pressure(HP)metamorphism in the South American ***-Nd and Lu-Hf isotopic data combined with U-Pb geochronological data from the Campo Grande area,Rio Grande do Norte domain,in the Northern Borborema Province,reflect a complex Archean(2.9 Ga and 2.6 Ga)and Paleoproterozoic(2.0 Ga)evolution,culminating in the Neoproterozoic Brasiliano/Pan-African orogeny(ca.600 Ma).The preserved mafic rocks contain massive poikiloblastic garnet and granoblastic amphibole with variable proportions of plagioclase+diopside in symplectitic texture,typical of high-pressure *** clinopyroxene-garnet amphibolites and the more common garnet amphibolites from the Campo Grande area are exposed as rare lenses within an Archean migmatite *** amphibolite lenses represent 2.65 Ga juvenile tholeiitic magmatism derived from depleted mantle sources(positive values of+3.81 to+30.66)later enriched by mantle metasomatism(negative εNd(t)values of-7.97).Chondrite and Primitive Mantle-normalized REE of analyzed samples and discriminant diagrams define two different oceanic affinities,with E-MORB and OIB *** Eu anomalies(Eu/Eu*=0.75-0.95)indicate depletion of plagioclase in the *** zircon cores of 3.0-2.9 Ga in analyzed samples indicate that the Neoarchean tholeiitic magmatism was emplaced into 2923±14 Ma old Mesoarchean crust(εNd(t)--2.58 and Nd TDM=3.2 Ga)of the Rio Grande do Norte *** age of retro-eclogite facies metamorphism is not yet completely *** suggest that two high-grade metamorphic events are recognized in the mafic rocks:the first at 2.0 Ga,recorded in some samples,and the second,at ca.600 Ma,stronger and more pervasive and recorded in several of the mafic rock *** Neoproterozoic zircon grains are found in symplectite texture as inclusions in the garnet grains and represent the age of HP conditions in the *** zircon grains show a

关键词： Archean oceanic crust Proterozoic orogens Borborema province