Parametrização de um modelo para estimativa da produtividade de soja para as regiões sul e centro-oeste do Brasil.

A produtividade de qualquer cultivo agrícola é resultado da interação genótipo e ambiente. No Brasil, cerca de 95% das indenizações pagas pelos instrumentos públicos de seguridade agrícola do Brasil estão relacionados à seca ou aos eventos de à chuva em excesso, mostrando sua importância. Na cultura de soja há dois períodos críticos no caso de déficit hídrico: da semeadura à emergência e no enchimento dos grãos. Em se tratando de um país como o Brasil cuja dimensão é continental e o cultivo de soja é nacional, a utilização de modelos que permitam obter estimativas confiáveis, rápidas e que necessitem de poucos dados operacionais são essenciais para seu gerenciamento. Usando o Modelo da Zona Agroecológica (MZA) foi feita a estimativa da produtividade de soja, a fim de se utilizar dados de fácil obtenção e que permitissem sua utilização em diversas localidades. O modelo foi avaliado para as condições das regiões Sul e Centro-Oeste entre as safras entre 2002 a 2006. Comparou-se as estimativas com os dados experimentais, verificando-se o bom desempenho do método para as regiões estudadas, com R²=0,54 numa análise global, mas com R²=0,97 para Dourados (MS) e R²=0,70 para Londrina (PR).CBA 2009

Seabird colonies as relevant sources of pollutants in Antarctic ecosystems: Part 2 - Persistent Organic Pollutants

International audienceDespite typically not being taken into account (usually in favour of the "Global Distillation" process), the input of Persistent Organic Pollutants (POPs) via biological activity can be indeed relevant at the local scale in terrestrial Polar environments when seabird colonies are considered. The fact that seabirds bioaccumulate and biomagnify those POPs, gather in large numbers and excrete on land during their reproductive season can act locally as relevant secondary source of the same contaminants. The first part of this study indicated that these colonies act as so for several essential and non-essential trace elements and this second part tests the same hypothesis concerning POPs using the very same samples. Lichens (n=55), mosses (n=58) and soil (n=37) were collected in 13 locations within the South Shetlands Archipelago during the austral summers of 2013-14 and 2014-15. They were divided in colony (within the colony itself for soil and bordering it for vegetation) and control (at least 150m away from any colony interference), analysed for POPs: organochlorine pesticides, polychlorinated byphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs); and stable isotopes (C and N). Results showed that colonies act clearly as a secondary source for PCBs and likely for HCB. As in the first part, probable local sources other than the colonies themselves are hypothesised due to high concentrations found in control sites. Again, soil seemed the most adequate matrix for the intended purposes especially because of some particularities in the absorption of animal derived organic matter by vegetation, pointed out by stable isotope analyses

Why early tactile speech aids may have failed: no perceptual integration of tactile and auditory signals

Tactile speech aids, though extensively studied in the 1980s and 90s, never became a commercial success. A hypothesis to explain this failure might be that it is difficult to obtain true perceptual integration of a tactile signal with information from auditory speech: exploitation of tactile cues from a tactile aid might require cognitive effort and so prevent speech understanding at the high rates typical of everyday speech. To test this hypothesis, we attempted to create true perceptual integration of tactile with auditory information in what might be considered the simplest situation encountered by a hearing-impaired listener. We created an auditory continuum between the syllables BA and VA, and trained participants to associate BA to one tactile stimulus VA to another tactile stimulus. After training, we tested if auditory discrimination along the continuum between the two syllables could be biased by incongruent tactile stimulation. We found that such a bias occurred only when the tactile stimulus was above its previously measured tactile discrimination threshold. Such a pattern is compatible with the idea that the effect is due to a cognitive or decisional strategy, rather than to truly perceptual integration. We therefore ran a further study, where we created a tactile version of the McGurk effect. We extensively trained two Subjects over six days to associate four recorded auditory syllables with four corresponding apparent motion tactile patterns. In a subsequent test, we presented stimulation that was either congruent or incongruent with the learnt association, and asked Subjects to report the syllable they perceived. We found no analog to the McGurk effect. These findings strengthen our hypothesis according to which tactile aids failed because integration of tactile cues with auditory speech occurred at a cognitive or decisional level, rather than truly at a perceptual leve

Surface Rupture of the November 2002 M7.9 Denali Fault Earthquake, Alaska, and Comparison to Other Strike-Slip Ruptures

On November 3, 2002, a moment-magnitude (Mw) 7.9 earthquake produced 340 km of surface rupture on the Denali fault and two related faults in central Alaska. The rupture, which proceeded from west to east, began with a 40-km-long break on a previously unknown thrust fault. Estimates of surface slip on this thrust were 3-6 m. Next came the principal surface break, along 220 km of the Denali fault. There, right-lateral offset averaged almost 5 m and increased eastward to a maximum of nearly 9 m. Finally, slip turned southeastward onto the Totschunda fault, where dextral offsets up to 3 m continued for another 70 km. This three-part rupture ranks among the longest documented strike-slip events of the past two centuries. The surface-slip distribution supports and clarifies models of seismological and geodetic data that indicated initial thrusting followed by rightlateral strike slip, with the largest moment release near the east end of the Denali fault. The Denali fault ruptured beneath the Trans-Alaska oil pipeline. The pipeline withstood almost 6 m of lateral offset, because engineers designed it to survive such offsets based on pre-construction geological studies. The Denali fault earthquake was typical of large-magnitude earthquakes on major intracontinental strike-slip faults, in the length of the rupture, the multiple fault strands that ruptured, and the variable slip along strike

Surface Rupture and Slip Distribution of the Denali and Totschunda Faults

The 3 November 2002 Denali fault, Alaska, earthquake resulted in 341 km of surface rupture on the Susitna Glacier, Denali, and Totschunda faults. The rupture proceeded from west to east and began with a 48-km-long break on the previously unknown Susitna Glacier thrust fault. Slip on this thrust averaged about 4 m (Crone et al., 2004). Next came the principal surface break, along 226 km of the Denali fault, with average right-lateral offsets of 4.5–5.1 m and a maximum offset of 8.8 m near its eastern end. The Denali fault trace is commonly left stepping and north side up. About 99 km of the fault ruptured through glacier ice, where the trace orientation was commonly influenced by local ice fabric. Finally, slip transferred southeastward onto the Totschunda fault and continued for another 66 km where dextral offsets average 1.6–1.8 m. The transition from the Denali fault to the Totschunda fault occurs over a complex 25-km-long transfer zone of right-slip and normal fault traces. Three methods of calculating average surface slip all yield a moment magnitude of Mw 7.8, in very good agreement with the seismologically determined magnitude of M 7.9. A comparison of strong-motion inversions for moment release with our slip distribution shows they have a similar pattern. The locations of the two largest pulses of moment release correlate with the locations of increasing steps in the average values of observed slip. This suggests that slipdistribution data can be used to infer moment release along other active fault traces.PublishedS23–S52reserve