Biochemical Aspects of a Serine Protease from Caesalpinia echinata Lam. (Brazilwood) Seeds: A Potential Tool to Access the Mobilization of Seed Storage Proteins

Several proteins have been isolated from seeds of leguminous, but this is the first report that a protease was obtained from seeds of Caesalpinia echinata Lam., a tree belonging to the Fabaceae family. This enzyme was purified to homogeneity by hydrophobic interaction and anion exchange chromatographies and gel filtration. This 61-kDa serine protease (CeSP) hydrolyses H-D-prolyl-L-phenylalanyl-L-arginine-p-nitroanilide (Km 55.7 μM) in an optimum pH of 7.1, and this activity is effectively retained until 50°C. CeSP remained stable in the presence of kosmotropic anions (PO4 3−, SO4 2−, and CH3COO−) or chaotropic cations (K+ and Na+). It is strongly inhibited by TLCK, a serine protease inhibitor, but not by E-64, EDTA or pepstatin A. The characteristics of the purified enzyme allowed us to classify it as a serine protease. The role of CeSP in the seeds cannot be assigned yet but is possible to infer that it is involved in the mobilization of seed storage proteins

Paleoambiente Deposicional de Folhelhos da Formação Pimenteiras da Borda Oeste da Bacia do Parnaíba, NE - Brasil

Os folhelhos da Formação Pimenteiras depositados em ambiente marinho durante o Devoniano (Frasniano), são ricos em matéria orgânica e constituem a principal rocha geradora da Bacia do Parnaíba. Este trabalho tem como objetivo caracterizar o paleoambiente deposicional da Formação Pimenteiras com base no estudo de Geoquímica Orgânica e Palinofácies. Foram coletadas 21 amostras de rocha em um afloramento próximo ao município de Aparecida do Rio Negro, na borda Oeste da Bacia, no estado de Tocantins, onde havia aspecto estratigráfico do contato entre as Formações Cabeças (Fameniano) e Pimenteiras (Frasniano). Os teores de carbono orgânico total (COT) variaram de 0,21 a 2,43 % e os resultados da pirólise Rock Eval indicam querogênio predominantemente dos tipos II e III, potencial gerador de hidrocarbonetos (S2) variando de pobre a médio (0,41 - 6,13 mgHC/g rocha), baixa concentração de hidrocarbonetos livres (S1) e imaturidade térmica (Tmáx) para a geração de petróleo. O estudo de palinofácies permitiu identificar e quantificar os componentes particulados da matéria orgânica dos grupos dos palinomorfos, fitoclastos e matéria orgânica amorfa (MOA). Um número considerável de prasinófitas dos gêneros Pterospermella, Cymatiosphaera, Durvenaysphaera, Leiosphaeridia, Tasmanites, Hemiruptia e Maranhites foram identificadas, sugerindo as superfícies da inundação possivelmente da idade do Frasniano. Ao longo do afloramento as amostras apresentaram variação quantitativa de componentes orgânicos de origem terrestre, caracterizando regressões marinhas, e outras amostras, sugerindo transgressões marinhas, com o aumento de prasinófitas e acritarcas. A razão dos isótopos de carbono orgânico (δ13C: -25,9 a -29,5‰) e os biomarcadores saturados (esteranos regulares C27-C28-C29 e razão TPP/(TPP+DIA)), também sugerem uma alternância no “input” da matéria orgânica terrestre e marinha

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe