904 resultados para SENSORY ORGANIZATION
Resumo:
The time is ripe for a comprehensive mission to explore and document Earth's species. This calls for a campaign to educate and inspire the next generation of professional and citizen species explorers, investments in cyber-infrastructure and collections to meet the unique needs of the producers and consumers of taxonomic information, and the formation and coordination of a multi-institutional, international, transdisciplinary community of researchers, scholars and engineers with the shared objective of creating a comprehensive inventory of species and detailed map of the biosphere. We conclude that an ambitious goal to describe 10 million species in less than 50 years is attainable based on the strength of 250 years of progress, worldwide collections, existing experts, technological innovation and collaborative teamwork. Existing digitization projects are overcoming obstacles of the past, facilitating collaboration and mobilizing literature, data, images and specimens through cyber technologies. Charting the biosphere is enormously complex, yet necessary expertise can be found through partnerships with engineers, information scientists, sociologists, ecologists, climate scientists, conservation biologists, industrial project managers and taxon specialists, from agrostologists to zoophytologists. Benefits to society of the proposed mission would be profound, immediate and enduring, from detection of early responses of flora and fauna to climate change to opening access to evolutionary designs for solutions to countless practical problems. The impacts on the biodiversity, environmental and evolutionary sciences would be transformative, from ecosystem models calibrated in detail to comprehensive understanding of the origin and evolution of life over its 3.8 billion year history. The resultant cyber-enabled taxonomy, or cybertaxonomy, would open access to biodiversity data to developing nations, assure access to reliable data about species, and change how scientists and citizens alike access, use and think about biological diversity information.
Resumo:
This paper is intended as a proposition of a new concept in the field of chronobiology, External Temporal Organization, a notion complementary to that of the Internal Temporal Organization. We will try to explain the possibility that a set of external elements, that occur in a particular order, can act together as a single synchronizing element of the circadian system. We will see that this is not a zeitgeber, in the classic sense, but a much more complex factor, consisting of several elements that appear in the real environment at different times ( phases), constituting as a whole a powerful temporal frame, closer to the way the stimuli occur in the natural environment, in which the entrainment does not take place just in a specific time of the day.
Resumo:
Trypanosoma cruzi, the agent of Chagas disease, is a complex of genetically diverse isolates highly phylogenetically related to T. cruzi-like species, Trypanosoma cruzi marinkellei and Trypanosoma dionisii, all sharing morphology of blood and culture forms and development within cells. However, they differ in hosts, vectors and pathogenicity: T. cruzi is a human pathogen infective to virtually all mammals whilst the other two species are non-pathogenic and bat restricted. Previous studies suggest that variations in expression levels and genetic diversity of cruzipain, the major isoform of cathepsin L-like (CATL) enzymes of T. cruzi, correlate with levels of cellular invasion, differentiation, virulence and pathogenicity of distinct strains. In this study, we compared 80 sequences of genes encoding cruzipain from 25 T. cruzi isolates representative of all discrete typing units (DTUs TcI-TcVI) and the new genotype Tcbat and 10 sequences of homologous genes from other species. The catalytic domain repertoires diverged according to DTUs and trypanosome species. Relatively homogeneous sequences are found within and among isolates of the same DTU except TcV and TcVI, which displayed sequences unique or identical to those of TcII and TcIII, supporting their origin from the hybridization between these two DTUs. In network genealogies, sequences from T. cruzi clustered tightly together and closer to T. c. marinkellei than to T. dionisii and largely differed from homologues of T. rangeli and T. b. brucei. Here, analysis of isolates representative of the overall biological and genetic diversity of T. cruzi and closest T. cruzi-like species evidenced DTU- and species-specific polymorphisms corroborating phylogenetic relationships inferred with other genes. Comparison of both phylogenetically close and distant trypanosomes is valuable to understand host-parasite interactions, virulence and pathogenicity. Our findings corroborate cruzipain as valuable target for drugs, vaccine, diagnostic and genotyping approaches.
Resumo:
Case fatality rate is considered a main determinant of stroke mortality trends. We applied the World Health Organization's Stroke STEPS to identify case fatality rates in a community hospital in Brazil. We evaluated all patients with first-ever stroke seeking acute care at the hospital's emergency ward between April 2006 and December 2008 to verify early and late case fatality according to stroke subtype. We used years of formal education as a surrogate for socioeconomic status. Of 430 first-ever stroke events, 365 (84.9%) were ischemic and 65 (15.1%) were intracerebral hemorrhage. After 1 year, we adjudicated 108 deaths (86 ischemic; 22 hemorrhagic). Age-adjusted case fatality rates for ischemic stroke and intracerebral hemorrhage were 6.0% v 19.8% at 10 days, 10.6% v 22.1% at 28 days, 17.6% v 29.1% at 6 months, and 21.0% v 31.5% at 1 year. Illiteracy or no formal education was a predictor of death at 6 months (odds ratio [OR], 4.31; 95% confidence interval [CI] 1.34-13.91) and 1 year (OR, 4.21; 95% CI, 1.45-12.28) in patients with ischemic stroke, as well as at 6 months (OR, 3.19; 95% CI, 1.17-8.70) and 1 year (OR, 3.30; 95% CI, 1.30-8.45) for all stroke patients. Other variables, including previous cardiovascular risk factors and acute medical care, did not change this association to a statistically significant degree. In conclusion, case fatality, particularly up to 6 months, was higher in hemorrhagic stroke, and lack of formal education was associated with increased stroke mortality.