Oxidation reactions of derivatives of cis-octalins promoted by thallium trinitrate (TTN)

The reaction of ten cis-octalins and cis-octalones with thallium trinitrate (TTN) leads to different products, depending mainly on the substitution pattern of the substrate. Functionalized cis-hydrindanes were obtained from the reaction of 1,2,3,4,4a,5,8,8a-octahydro-4a-methylnaphthalene and of 1,2,3,4,4a,5,8,8a-octahydro-4a,7-dimethylnaphthalene with TTN in acetonitrile, whereas a cyclic ether was formed treating 1,2,3,4,4a,5,8,8a-octahydro-6,8a-dimethylnaphthalen-1-ol with TTN in trimethylorthoformate (TMOF).FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Clinical Characteristics and Outcomes of Chagas Disease in the United States: A Multicenter Retrospective Analysis

Chagas disease affects approximately 300,000 patients in the United States. We evaluated a multicenter U.S.-based network to obtain clinical characteristics and outcomes of chronic Chagas disease by disease forms. This was a U.S.-based, multicenter, population-based, retrospective cohort study. We queried TriNetX, a global research network, to identify patients with dual-positive IgG serology for Trypanosoma cruzi. We captured outcomes of interest for up to 5 years. We found 429 patients with evidence of dual-positive T. cruzi IgG out of 19,831 patients with an available test result from 31 U.S. medical centers. The positive proportion for those tested was 2.2%, up to 4.6% among Hispanics. We found a prevalence of a positive Chagas serology of 0.02% among Hispanics. Cardiomyopathy risk reached an annual rate of 1.3% during the initial 5 years of follow-up among patients with the indeterminate form. We found no new events for pulmonary embolism, sudden death, or left ventricular aneurysms at 5 years. Annual risks for arrhythmias and stroke for chronic Chagas cardiomyopathy (CCC) were 1.6% and 0.8%, respectively. The yearly mortality and hospitalization rates for CCC were 2.7% and 17.1%, respectively. Only 13 patients had a documented antitrypanosomal therapy course within 6 months after diagnosis. Of those receiving treatment, 10 patients received benznidazole and three nifurtimox. Chagas disease screening in patients from endemic areas living in the United States remains crucial. Chronic Chagas cardiomyopathy carries a considerable disease burden, translating into increased morbidity and mortality and an enlarging medical health service utilization

Oxidation of tertiary homoallylic alcohols by thallium trinitrate: fragmentation vs. ring contraction

The oxidation of tertiary homoallylic alcohols with thallium trinitrate (TTN) was investigated. The alcohols bearing an allylic methyl group lose a molecule of acetone via a fragmentation reaction that leads to isomeric secondary allylic alcohols as major products, together with their corresponding acetylated derivatives. On the other hand, treating analogous tertiary alcohols without the allylic methyl group with TTN gives indans, through a ring contraction reaction.A oxidação de álcoois homoalílicos terciários com trinitrato de tálio (TTN) foi investigada. Os álcoois que possuem uma metila na posição alílica perdem uma molécula de acetona via uma reação de fragmentação, levando a uma mistura de álcoois alílicos isoméricos como principais produtos, juntamente com os correspondentes derivados acetilados. Por outro lado, o tratamento com TTN de álcoois terciários análogos, sem a metila na posição alílica, fornece indanos, através de uma reação de contração de anel.981988Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Management Effect on Rainfall Use Efficiency and Growth Rate of Spineless Cactus \u3cem\u3ecv.\u3c/em\u3e Miúda in Northeast Brazil

Spineless cactus has a high rainfall use efficiency. Under water deficit, they open their stomata during the night to capture atmospheric carbon dioxide when the air temperature is lower and relative humidity higher (Taiz and Zeiger, 2009), losing less water to the atmosphere. The rainfall use efficiency (RUE) can be expressed as the amount of water used by the crop to produce dry matter (Han and Felker, 1997). The RUE showed by spineless cactus, a CAM plant, is three to five times greater than the one observed in C3 and C4 plants (Felker and Russel, 1988; Nobel, 1991). Therefore, spineless cacti (Nopaleae opuntia) are important forage resource in northeast Brazil. Management practices, however, can affect the RUE and growth of spineless cactus, especially organic and mineral fertilization. Thus, the objective of this research was to evaluate the effect of organic and nitrogen fertilization and harvest frequency on rainfall use efficiency and growth rate of spineless cactus cv. Miúda (Nopalea cochenillifera Salm Dyck)

Widespread forest vertebrate extinctions induced by a mega hydroelectric dam in lowland Amazonia

Mega hydropower projects in tropical forests pose a major emergent threat to terrestrial and freshwater biodiversity worldwide. Despite the unprecedented number of existing, underconstruction and planned hydroelectric dams in lowland tropical forests, long-term effects on biodiversity have yet to be evaluated. We examine how medium and large-bodied assemblages of terrestrial and arboreal vertebrates (including 35 mammal, bird and tortoise species) responded to the drastic 26-year post-isolation history of archipelagic alteration in landscape structure and habitat quality in a major hydroelectric reservoir of Central Amazonia. The Balbina Hydroelectric Dam inundated 3,129 km2 of primary forests, simultaneously isolating 3,546 land-bridge islands. We conducted intensive biodiversity surveys at 37 of those islands and three adjacent continuous forests using a combination of four survey techniques, and detected strong forest habitat area effects in explaining patterns of vertebrate extinction. Beyond clear area effects, edge-mediated surface fire disturbance was the most important additional driver of species loss, particularly in islands smaller than 10 ha. Based on species-area models, we predict that only 0.7% of all islands now harbor a species-rich vertebrate assemblage consisting of ≥80% of all species. We highlight the colossal erosion in vertebrate diversity driven by a man-made dam and show that the biodiversity impacts of mega dams in lowland tropical forest regions have been severely overlooked. The geopolitical strategy to deploy many more large hydropower infrastructure projects in regions like lowland Amazonia should be urgently reassessed, and we strongly advise that long-term biodiversity impacts should be explicitly included in pre-approval environmental impact assessments

Fine mapping of genomic regions associated with female fertility in Nellore beef cattle based on sequence variants from segregating sires

Impaired fertility in cattle limits the efficiency of livestock production systems. Unraveling the genetic architecture of fertility traits would facilitate their improvement by selection. In this study, we characterized SNP chip haplotypes at QTL blocks then used whole-genome sequencing to fine map genomic regions associated with reproduction in a population of Nellore (Bos indicus) heifers.https://doi.org/10.1186/s40104-019-0403-

Numerical Approaches to Spacetime Singularities

This Living Review updates a previous version which its itself an update of a review article. Numerical exploration of the properties of singularities could, in principle, yield detailed understanding of their nature in physically realistic cases. Examples of numerical investigations into the formation of naked singularities, critical behavior in collapse, passage through the Cauchy horizon, chaos of the Mixmaster singularity, and singularities in spatially inhomogeneous cosmologies are discussed.Comment: 51 pages, 6 figures may be found in online version: Living Rev. Relativity 2002-1 at www.livingreviews.or

Modeling Disease Vector Occurrence when Detection Is Imperfect: Infestation of Amazonian Palm Trees by Triatomine Bugs at Three Spatial Scales

Blood-sucking bugs of the genus Rhodnius are major vectors of Chagas disease. Control and surveillance of Chagas disease transmission critically depend on ascertaining whether households and nearby ecotopes (such as palm trees) are infested by these vectors. However, no bug detection technique works perfectly. Because more sensitive methods are more costly, vector searches face a trade-off between technical prowess and sample size. We compromise by using relatively inexpensive sampling techniques that can be applied multiple times to a large number of palms. With these replicated results, we estimate the probability of failing to detect bugs in a palm that is actually infested. We incorporate this information into our analyses to derive an unbiased estimate of palm infestation, and find it to be about 50% – twice the observed proportion of infested palms. We are then able to model the effects of regional, landscape, and local environmental variables on palm infestation. Individual palm attributes contribute overwhelmingly more than landscape or regional covariates to explaining infestation, suggesting that palm tree management can help mitigate risk locally. Our results illustrate how explicitly accounting for vector, pathogen, or host detection failures can substantially improve epidemiological parameter estimation when perfect detection techniques are unavailable