Ambiente tectônico e controles estruturais do magmatismo kimberlítico no Brasil

Orientador: Elson Paiva de OliveiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de GeociênciasResumo: Em escala global o alojamento de kimberlitos é controlado por estruturas translitosféricas pré-existentes ou recém formadas por tectonica de placas conhecidas como Lineamentos continentais. Esses lineamentos são formados durante a reorganização de placas antes da formação de riftes oceânicos e estendem-se para o rifte oceânico e falhas transformantes em desenvolvimento antes da deriva. Finalmente as placas derivam. Deste modo, há uma ligação genética entre lineamentos continentais translitosféricos, seus equivalentes em falhas transformantes oceânicas e o alojamento de kimberlitos. O Corredor 125 no Brasil é um desses lineamentos continentais translitosféricos que hospedam kimberlitos e outras rochas máfico-ultramáficas. O alinhamento de rochas máficas e ultramáficas nas partes amazônica e extra-amazônica do Corredor 125 é apenas uma coincidência. A parte extra-amazônica do corredor foi formada inicialmente há 1.8 Ga e foi reativada várias vezes desde então como evidenciado por diferentes grupos de idades de diques máficos, agrupamentos de kimberlitos e de outras rochas máficas ao longo de todo o seu comprimento e largura. A ativação estrutural mais antiga na parte amazônica do corredor ocorreu há 1.8 Ga. Os kimberlitos ao longo do Corredor 125 formam picos de idades entre 226 e 268 Ma, 120 e 122 Ma, 80 e 94 Ma e em 74 Ma. A reconstrução tectônica da placa sul-americana revela que a trajetórica da trilha do hotspot Trindade-Martim Vaz não coincide com o Corredor 125 e que não há nenhuma progressão aparente na idade de kimberlitos ao longo do corredor. Diferente de sugestões anteriores, a trilha do hotspot Trindade-Martim Vaz como possível fonte de alojamento do magma kimberlítico é descartada. Ao contrário, o alojamento de kimberlitos esteve relacionado provavelmente à reorganização do supercontinente Pangea (kimberlitos de 226-268 Ma), incipiente abertura do Oceâno Atlantico de 120 a 122 Ma quando o movimento da placa sul-americana foi caracterizado por zig-zags, e a última fase de intrusão de kimberlitos entre 80 e 94 Ma e há aproximadamente 74 Ma quando houve o segundo aumento na velocidade da placa. Os períodos de tempo desprovidos de kimberlitos são estágios quando a placa sul-americana esteve estável ou experimentando velocidade e direção de movimento regularAbstract: On a global scale kimberlite emplacement is controlled by pre-existing/newly formed translithospheric structures known as Continental Lineaments due to plate tectonics. These translithospheric continental lineaments are formed during plate-reorganisation prior to oceanic rift formation. Further these lineaments extend onto the newly developing oceanic rift and transform fractures prior to the drift. Finally the plates drift apart. Hence, there is a genetic link between continental translithospheric lineaments, its oceanic transform fracture counterparts and associated kimberlite emplacement. Corridor-125 in Brazil is one such continental translithospheric lineaments, which host kimberlites and other mafic/ultramafic rocks. This Amazonian part and Extra-Amazonian part of the corridor is a coincidental alignment along with its associated mafic and ultramafic magmatism. The Extra-Amazonian part of this corridor was formed initially about 1.8 Ga and has been reactivated several times as evidenced by different age group of mafic dyke swarm, kimberlite clusters and other mafic rocks along its entire length and width. The oldest known structural activation on the Amazonian part of the corridor is 1.8 Ga. The kimberlite age along Corridor-125 is found to peak at 226 to 268 Ma, 120 to 122 Ma, 80 to 94 Ma and 74 Ma. Plate tectonic reconstruction of South American plate reveals the path of Trinidad-Martin Vaz (TMV) hotspot trail does not coincide with the Corridor and there is no apparent kimberlite age progression along Corridor-125. Unlike previous suggestions, the role of TMV as possible source for kimberlite emplacement is ruled out. The kimberlite emplacement is rather related to Pangea supercontinent plate re-organization (226-268 Ma kimberlites); incipient South Atlantic rifting from 120 to 122 Ma when the South American plate movement was characterized by cusps and jogs; and the last phase of kimberlite emplacement from 80 to 94 and 74 Ma is due to the second phase of increased plate velocity. The quiescent periods devoid of kimberlites are stages when the South American plate was stable or experiencing a smooth plate velocity and directionDoutoradoGeologia e Recursos NaturaisDoutora em Geociências190304/2010-3CNP

Mitochondrial fusion and Bid-mediated mitochondrial apoptosis are perturbed by alcohol with distinct dependence on its metabolism

Environmental stressors like ethanol (EtOH) commonly target mitochondria to influence the cell’s fate. Recent literature supports that chronic EtOH exposure suppresses mitochondrial dynamics, central to quality control, and sensitizes mitochondrial permeability transition pore opening to promote cell death. EtOH-induced tissue injury is primarily attributed to its toxic metabolic products but alcoholism also impairs tissues that poorly metabolize EtOH. We embarked on studies to determine the respective roles of EtOH and its metabolites in mitochondrial fusion and tBid-induced mitochondrial apoptosis. We used HepG2 cells that do not metabolize EtOH and its engineered clone that expresses EtOH-metabolizing Cytochrome P450 E2 and alcohol dehydrogenase (VL-17A cells). We found that fusion impairment by prolonged EtOH exposure was prominent in VL-17A cells, probably owing to reactive oxygen species increase in the mitochondrial matrix. There was no change in fusion protein abundance, mitochondrial membrane potential or Ca2+ uptake. By contrast, prolonged EtOH exposure promoted tBid-induced outer mitochondrial membrane permeabilization and cell death only in HepG2 cells, owing to enhanced Bak oligomerization. Thus, mitochondrial fusion inhibition by EtOH is dependent on its metabolites, whereas sensitization to tBid-induced death is mediated by EtOH itself. This difference is of pathophysiological relevance because of the tissue-specific differences in EtOH metabolism. © 2018, The Author(s)

Gamma Ray Induced Meiotic Abnormalities in S13 Mulberry

S13is a drought tolerant mulberry variety cultivated under rainfed condition. In order to increase the leaf yield and toimprove the quality the hard wood stem cuttings of this taxon were irradiated with Gamma-rays (4kR, 5kR, 6kR, 7kR,8kR, 9kR and 10kR). Comparable controls were also maintained. It is observed that the lower dosages of gamma-rays i.e.,4kR and 5kR were less effective in inducing variability. At higher dosages viz., 8kR, 9kR and 10kR deformity and inhibition of growth leading to semi lethality to complete lethality was observed. Like delayed sprouting, poor rooting,weathering of inflorescence, stunted growth, plants with weak and feeble branches, plants bearing small leaves withwrinkled and coriacious texture were observed. On the other hand, the moderate dosage like 6kR was found to be fruitful in the induction of beneficial variability in S13 mulberry variety. Some of these variants also displayed cytological abnormalities such as anaphase -I with laggard, precocious movement of chromosomes, univalents and bivalents atmetaphase-I, disturbed prophase-II and metaphase-II

Thamodaran. P

Not AvailableUsually, most of the genes are biallelically expressed but imprinted gene exhibit monoallelic expression based on their parental origin. Genomic imprinting exhibit differences in control between flowering plants and mammals, for instance, imprinted gene are specifically activated by demethylation, rather than targeted for silencing in plants and imprinted gene expression in plant which occur in endosperm. It also displays sexual dimorphism like differential timing in imprint establishment and RNA based silencing mechanism in paternally repressed imprinted gene. Within imprinted regions, the unusual occurrence and distribution of various types of repetitive elements may act as genomic imprinting signatures. Imprinting regulation probably at many loci involves insulator protein dependent and higher-order chromatin interaction, and/or non-coding RNAs mediated mechanisms. However, placentaspecific imprinting involves repressive histone modifications and non-coding RNAs. The higher-order chromatin interaction involves differentially methylated domains (DMDs) exhibiting sex-specific methylation that act as scaffold for imprinting, regulate allelic-specific imprinted gene expression. The paternally methylated differentially methylated regions (DMRs) contain less CpGs than the maternally methylated DMRs. The non-coding RNAs mediated mechanisms include C/D RNA and microRNA, which are invovled in RNA-guided post-transcriptional RNA modifications and RNA-mediated gene silencing, respectively. The maintenance and reprogramming of imprinting are not significantly affected by reduced expression of Dicer1 and the evolution of imprinting might be related to acquisition of DNMT3L (de novo methyltransferase 3L) by a common ancestor of eutherians and marsupials. The common feature among diverse imprinting control elements and evolutionary significance of imprinting need to be identified.Not Availabl

VDAC-dependent permeabilization of the outer mitochondrial membrane by superoxide induces rapid and massive cytochrome c release

Enhanced formation of reactive oxygen species (ROS), superoxide (O2·−), and hydrogen peroxide (H2O2) may result in either apoptosis or other forms of cell death. Here, we studied the mechanisms underlying activation of the apoptotic machinery by ROS. Exposure of permeabilized HepG2 cells to O2·− elicited rapid and massive cytochrome c release (CCR), whereas H2O2 failed to induce any release. Both O2·− and H2O2 promoted activation of the mitochondrial permeability transition pore by Ca2+, but Ca2+-dependent pore opening was not required for O2·−-induced CCR. Furthermore, O2·− alone evoked CCR without damage of the inner mitochondrial membrane barrier, as mitochondrial membrane potential was sustained in the presence of extramitochondrial ATP. Strikingly, pretreatment of the cells with drugs or an antibody, which block the voltage-dependent anion channel (VDAC), prevented O2·−-induced CCR. Furthermore, VDAC-reconstituted liposomes permeated cytochrome c after O2·− exposure, and this release was prevented by VDAC blocker. The proapoptotic protein, Bak, was not detected in HepG2 cells and O2·−-induced CCR did not depend on Bax translocation to mitochondria. O2·−-induced CCR was followed by caspase activation and execution of apoptosis. Thus, O2·− triggers apoptosis via VDAC-dependent permeabilization of the mitochondrial outer membrane without apparent contribution of proapoptotic Bcl-2 family proteins

Mogućnost hepatotoksičnoga djelovanja malationa u slatkovodnoga teleosta Labeo rohita (Hamilton)

Freshwater edible fi sh, Labeo rohita, were exposed to a sublethal concentration (0.9 μl/L) of commercial grade malathion (50% Emulsifi ed Concentration) for 5, 15 and 25 d. After each exposure period, the liver was taken, to study biochemical alterations. An increase in free amino acid, protease activity and ACh levels, in contrast to decrement in total, structural and soluble proteins and AChE activity, were observed after 5 and l5 d exposure, but on 25 d exposure all the values came nearer to normal. Restoration of protein fractions, free amino acid, protease activity, ACh levels and AChE activity to normal implies that after 15 d of exposure there seems to exist an oscillatory phase in protein turnover towards a more synthetic phase, leading to the establishment of recuperation and adaptation phenomena.Slatkovodna jestiva riba Labeo rohita bila je izložena subletalnoj koncentraciji (0,9 μL/L) komercijalnoga pripravka malationa (50% emulzija) tijekom 5, 15 i 25 dana. Nakon razdoblja izloženosti jetra je bila uzeta za istraživanje biokemijskih poremećaja. Pet i 15 dana nakon izloženosti ustanovljena je povećana koncentracija slobodnih masnih kiselina, pojačana aktivnost proteaza i povećana razina acetilkolina, dok se smanjila ukupna količina proteina i aktivnost acetilkolinesteraze. Nakon 25 dana izloženosti za sve su pokazatelje ustanovljene gotovo normalne vrijednosti. Uspostava normalnih vrijednosti proteinskih frakcija, slobodnih masnih kiselina, aktivnosti proteaza, razine acetilkolina i aktivnosti acetilkolinesteraze nagovješćuje da se nakon 15 dana izloženosti javlja kolebajuća faza u metabolizmu s pojačanom sintezom proteina što dovodi do oporavka i prilagodbe novim uvjetima

Istraživanje oksidativnog stresa i genotoksičnosti slatkovodnih riba Cyprinus Carpio nakon izloženosti subletalnoj dozi triazofosa

Triazophos (TAP), an organophosphorus insecticide, is widely used in agricultural practice for controlling various insect pests. The present research work aimed to elucidate the impact of TAP on the antioxidant status and DNA content of the freshwater fish Cyprinus carpio. The fish were grouped into batches (n=6) and received a sublethal dose of 0.3mg/L for a duration of 1 (E1), 10 (E2), 20 (E3) and 30 days (E4). Another group, devoid of any toxicant, was maintained as the control (C). Changes in the enzymatic threshold of the selected antioxidants and malondialdehyde (MDA) levels suggested the conformation of oxidative stress in the livers of the freshwater fish C. carpio due to TAP exposure. Additionally, comet assays and micronucleus tests performed on the peripheral blood of the fish suggested increased damage in the form of the percentage of tail DNA formation and a high frequency of micronucleus as compared to the control. A positive correlation was seen between the decline in antioxidant activity, the elevation in MDA and the comet length and micronucleus frequency. The study thus highlights the impact of TAP on antioxidant levels in the livers and genotoxicity in the blood of the freshwater fish C. carpio. The findings of the study confirm that the antioxidant status, along with the comet assay and micronucleus tests could be used as tools in determining the potential genotoxicity due to the TAP impact. It is therefore suggested that extensive use of TAP should be avoided as it may contribute to the decline in the C. carpio population in its natural habitats.Triazofos (TAP) je organofosforni insekticid koji se široko koristi u poljoprivrednoj praksi za suzbijanje raznih štetnih insekata. Cilj ovog istraživanja bio je procjeniti utjecaj TAP-a na antioksidativni status i DNK slatkovodne ribe Cyprinus carpio. Ribe su razvrstane u skupine (n = 6) u kojima su primale subletalnu dozu TAP-a 0.3mg/L u trajanju od 1 (E1), 10 (E2), 20 (E3) i 30 dana (E4). Druga skupina, koja nije izložena TAP-u, smatrana je kontrolnom (C). Promjene enzimskog praga odabranih antioksidansa i razina malondialdehida (MDA) potvrdile su da izloženost TAP-u izaziva oksidativni stres u jetrama slatkovodne ribe C. carpio. Osim toga, komet analize i mikronukleusni testovi provedeni na perifernoj krvi riba ukazali su da u eksperimentalnih skupina u odnosu na kontrolu postoji povećani postotak oštećenja u obliku DNK repa i povećane učestalosti mikronukleusa. Uočena je pozitivna korelacija između pada antioksidativne aktivnosti, porasta MDA, duljine kometa i učestalosti mikronukleusa. Uzevši u obzir navedeno, istraživanje naglašava utjecaj TAP-a na razine antioksidansa u jetrama i genotoksičnost u krvi slatkovodne ribe C. carpio. Rezultati potvrđuju da se antioksidativni status, zajedno s kometnim testom i mikronukleusnim testovima, može koristiti kao alat za određivanje potencijalne genotoksičnosti TAP-a. Stoga se predlaže izbjegavanje široke uporaba TAP-a koja bi mogla doprinijeti smanjenju populacije C. carpio u njezinim prirodnim staništima

Implications of hybrid vigour, combining ability and per se performance in pigeonpea [Cajanus cajan (L.) Millsp.]

Three CGMS lines were crossed with 17 testers in a line × tester design during Kharif 2013 and sufficient number of hand pollinated seeds was produced. The resultant 51 hybrids along with their 20 parents and standard check variety (Maruti) were evaluated in RBD design with two replications. Combining ability analysis evinced predominance of non-additive gene effects for 7 characters indicating relevance of heterosis breeding for improving yield attributes. The gca effects of parents revealed that ICPA-2043, GRG-2009, GRG-2009-2, LAXMI, LRG-41 and JKM-197 were good general combiners for seed yield and it’s direct components. The estimates of sca effects revealed that 11 experimental hybrids had significant, desirable and positive sca effects for seed yield/plant. Among these, three best crosses were selected on the basis of per se performance for ascertaining their association with sca effects of seed yield per plant and its attributes. The investigation identified the good general combiners (ICPA -2043, GRG-2009, GRG-2009-2, LAXMI, LRG-41 and JKM-197) and promising crosses (ICPA-2043 X GRG-2009-2, ICPA-2047 X GRG-2OO9 and ICPA-2043 X ICPL-288) showing high mean and significant positive sca effects involved high × high gca effects of parents. These parental combinations may be used in breeding program for exploitation of hybrid vigour

Interpretation of genotype x environment interaction and stability analysis for grain yield of pigeon pea (Cajanus cajan L.)

Fourteen pigeon pea (Cajanus cajan L.) genotypes were evaluated for their yield performance at two locations during kharif season of 2009-10 and 2010-11. A significant genotypic difference for yield character was observed. Highly significant genotype–environment interaction indicated differential response of the genotypes to the environmental changes. The stability analysis showed significance of linear component of variation for grain yield. The genotypes TJT-501 (1728.667Kg/Ha) and GRG-2009-3 (1570.000 Kg/Ha) exhibited low meanperformance along with regression value nearer to unity (bi=1) and non significant deviation from regression (S2 di=0) indicating, the high stability and wider adaptability across the different environments. The genotype ICPH-2671 (3134.833 Kg/Ha) exhibited highest mean value and regression value (bi>1) and non significant deviation (S2 di < 0). But genotypes JKM-197 (3072.667 Kg/ha), GRG-2009 (29993.167 Kg/ha), TS-3R (2823.333 Kg / Ha) and ICP-8863 (2740.417 Kg/Ha) exhibited high mean performance but higher regression value (bi>1) and significant deviation (S2 di < 0) value indicating adapted for high performance environments showing these genotypes are sensitive to environments and give maximum yield when inputs are not limited