Policy issues and data communications for NASA earth observation missions until 1985

The series of LANDSAT sensors with the highest potential data rates of the missions were examined. An examination of LANDSAT imagery uses shows that relatively few require transmission of the full resolution data on a repetitive quasi real time basis. Accuracy of global crop size forecasting can possibly be improved through information derived from LANDSAT imagery. A current forecasting experiment uses the imagery for crop area estimation only, yield being derived from other data sources

The use of ultrasound in clinical setting for children affected by NAFLD. is it safe and accurate?

Non-alcoholic fatty liver disease (NAFLD) has become over the last decade the most common form of chronic liver disease in children and adults. Thus, establishing the diagnosis of NAFLD is of utmost importance and represents a major challenge as the disease is generally silent and the current gold standard for diagnosis is an invasive liver biopsy, a procedure that is not suitable for screening purposes. Many non-invasive diagnostic tools have been evaluated so far. Recently the utility of ultrasonography for non-invasive diagnosis and estimation of hepatic steatosis has been demonstrated in a large prospective pediatric study

Cephalometric studies of the mandible, its masticatory muscles and vasculature of growing Göttingen Minipigs — A comparative anatomical study to refine experimental mandibular surgery

Over many decades, the Göttingen Minipig has been used as a large animal model in experimental surgical research of the mandible. Recently several authors have raised concerns over the use of the Göttingen Minipig in this research area, observing problems with post-operative wound healing and loosening implants. To reduce these complications during and after surgery and to improve animal welfare in mandibular surgery research, the present study elucidated how comparable the mandible of minipigs is to that of humans and whether these complications could be caused by specific anatomical characteristics of the minipigs’ mandible, its masticatory muscles and associated vasculature. Twenty-two mandibular cephalometric parameters were measured on CT scans of Göttingen Minipigs aged between 12 and 21 months. Ultimately, we compared this data with human data reported in the scientific literature. In addition, image segmentation was used to determine the masticatory muscle morphology and the configuration of the mandibular blood vessels. Compared to data of humans, significant differences in the mandibular anatomy of minipigs were found. Of the 22 parameters measured only four were found to be highly comparable, whilst the others were not. The 3D examinations of the minipigs vasculature showed a very prominent deep facial vein directly medial to the mandibular ramus and potentially interfering with the sectional plane of mandibular distraction osteogenesis. Damage to this vessel could result in inaccessible bleeding. The findings of this study suggest that Göttingen Minipigs are not ideal animal models for experimental mandibular surgery research. Nevertheless if these minipigs are used the authors recommend that radiographic techniques, such as computed tomography, be used in the specific planning procedures for the mandibular surgical experiments. In addition, it is advisable to choose suitable age groups and customize implants based on the mandibular dimensions reported in this study

Low-loss amorphous silicon waveguides grown by PECVD on indium tin oxide

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All-optical modulation in a CMOS-compatible amorphous silicon-based device

Active silicon photonic devices, which dynamically control the flow of light, have received significant attention for their use in on-chip optical networks. High-speed active silicon photonic modulators and switches rely on the plasma dispersion effect, where a change in carrier concentration causes a variation in the refractive index. The necessary electron and hole concentration change can be introduced either by optical pumping, or by direct electrical injection and depletion. We demonstrate a fast photoinduced absorption effect in low loss hydrogenated amorphous silicon (a-Si:H) waveguides deposited at a temperature as low as 190°C. Significant modulation (M% ~90%) occurs with a 1 mm-long device. We attribute the enhanced modulation to the significantly larger free-carrier absorption effect of a-Si:H. The complementary metal-oxide semiconductor (CMOS) compatible technology of a-Si:H could be considered as a promising candidate to enable an easy back-end integration with standard microelectronics processes

Adubação de cobertura na batata-doce com doses combinadas de nitrogênio e potássio.

Resumo: A adubação balanceada de N e K frequentemente aumenta o desempenho das lavouras, contudo, a falta de um desses nutrientes em solos deficientes pode levar a decréscimos na resposta ao outro. O objetivo deste trabalho foi avaliar a produtividade de batata-doce comercializável, a quantidade de raízes tuberosas para descarte e a diagnose foliar de lavoura de batata-doce adubada com N e K. O experimento foi realizado em lavoura comercial, em Presidente Prudente-SP, de fevereiro a junho de 2007, em um Argissolo Vermelho distroférrico de textura média. O delineamento experimental foi em blocos completos casualizados, com quatro repetições, no esquema fatorial 4 x 4, com 0, 30, 60 e 120 kg há de N (uréia), em interação com 0, 30, 60 e 120 kg há de KO (KCl), aplicados em cobertura aos 39 dias após o plantio. A cultura da batata-doce é responsiva à adubação nitrogenada e potássica de cobertura, porém, os maiores incrementos de produtividade são alcançados com as doses de N e K combinadas. A adubação de cobertura com N e K não acarreta em aumento da quantidade de raízes tuberosas impróprias para a comercialização. O maior incremento de produtividade da batata-doce é alcançado com a adubação de cobertura combinada com 100 kg de N ha mais 120 kg de K. Abstract: Balanced fertilizations with N and K often increase the performance of crops, however, when there is absence of one of these nutrients in poor soils, can reduce crop response to fertilization with the other. The objective of this work was to evaluate the productivity of sweet-potato, the amount of sweetpotato without quality, and leaf nutrients analysis, of sweet-potato crop fertilized with N and K. The trial was conducted in farming for commercial production, in Presidente Prudente, São Paulo State, during February-June 2007, in a dystrophic Ultisol of medium texture. The experimental design was a randomized complete block design, with four replications, on factorial 4 x 4: levels of 0, 30, 60 and 120 kg N ha (urea source) combined with levels of 0, 30, 60 and 120 kg KO ha (KCl source), applied to 39 days after planting of the crop. The sweet-potato is responsive to topdressing application with nitrogen and potassium, however, the greatest increases in productivity occur when doses of N and K are combined. Fertilization with N and K not increase the amount of sweet-potato without quality marketing. The highest increase in productivity of sweet-potato is reached with topdressing combined with 100 kg N ha plus 120 kg KO ha

Exchange Rates and Sovereign Risk

We empirically investigate the relation between currency excess returns and sovereign risk, as measured by credit default swap (CDS) spreads. An increase in a country’s CDS spread is accompanied by a contemporaneous depreciation of its exchange rate as well as an increase of its currency volatility and crash risk. The link between currency excess returns and sovereign risk is mainly driven by exposure to global sovereign risk shocks and also emerges in a predictive setting for currency risk premia. Sovereign risk forecasts excess returns to trading exchange rates, volatility and skewness, and is strongly priced in the cross-section of currencies. Moreover, we find that sovereign risk accounts for a large share of carry trade returns, and that carry and momentum strategies generate high (low) returns across countries with high (low) sovereign risk

Photometry of the Oort Cloud comet C/2009 P1(Garradd): pre-perihelion observations at 5.7 and 2.5 AU

The aim of this paper is to contribute to the characterization of the general properties of the Long Period Comets (LPCs) family, and in particular to report on the dust environment of comet C/2009 P1 (Garradd). The comet was observed at two epochs pre-perihelion, at ~6 AU and at ~2.5 AU: broad-band images have been used to investigate its coma morphology and properties and to model the dust production rate. Comet C/2009 P1 (Garradd) is one of the most active and “dust producing” LPCs ever observed, even at the large heliocentric distance rh~6 AU. Its coma presents a complex morphology, with subtle structures underlying the classical fan-shaped tail, and, at rh~2.5 AU, also jet-like structures and spiralling outflows. In the reference aperture of radius ρ=5°×104 km, the R-Afρ is 3693±156 cm and 6368±412 cm, in August 2010 (rh~6 AU) and July 2011 (rh~2.5 AU), respectively. The application of a first order photometric model, under realistic assumptions on grain geometric albedo, power-law dust size distribution, phase darkening function and grain dust outflow velocity, yielded a measure of the dust production rate for the two epochs of observation of Qd=7.27×102 kg/s and Qd=1.37×103 kg/s, respectively, for a reference outflow dust velocity of vsmall=25 m/s for small (0.1–10 µm) grains and vlarge=1 m/s for large (10 µm–1 cm) grains. These results suggest that comet Garradd is one of the most active minor bodies observed in recent years, highly contributing to the continuous replenishment of the Interplanetary Dust Complex also in the outer Solar System, and pose important constraints on the mechanism(s) driving the cometary activity at large heliocentric distances