SeaWiFS long-term solar diffuser reflectance and sensor noise analyses

The NASA Ocean Biology Processing Group's Calibration and Validation (Cal/Val) team has undertaken an analysis of the mission-long Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) solar calibration time series to assess the long-term degradation of the solar diffuser reflectance over 9 years on orbit. The SeaWiFS diffuser is an aluminum plate coated with YB71 paint. The bidirectional reflectance distribution function of the diffuser was not fully characterized before launch, so the Cal/Val team has implemented a regression of the solar incidence angles and the drift in the node of the satellite's orbit against the diffuser time series to correct for solar incidence angle effects. An exponential function with a time constant of 200 days yields the best fit to the diffuser time series. The decrease in diffuser reflectance over the mission is wavelength dependent, ranging from 9% in the blue (412 nm) to 5% in the red and near infrared (670-865 nm). The Cal/Val team has developed a methodology for computing the signal-to-noise ratio (SNR) for SeaWiFS on orbit from the diffuser time series corrected for both the varying solar incidence angles and the diffuser reflectance degradation. A sensor noise model is used to compare on-orbit SNRs computed for radiances reflected from the diffuser with prelaunch SNRs measured at typical radiances specified for the instrument. To within the uncertainties in the measurements, the SNRs for SeaWiFS have not changed over the mission. The on-orbit performance of the SeaWiFS solar diffuser should offer insight into the long-term on-orbit performance of solar diffusers on other instruments, such as the Moderate-Resolution Imaging Spectrometer [currently flying on the Earth Observing System (EOS) Terra and Aqua satellites], the Visible and Infrared Radiometer Suite [scheduled to fly on the NASA National Polar-orbiting Operational Environmental Satellite System (NPOESS) and NPOESS Preparatory Project (NPP) satellites] and the Advanced Baseline Imager [scheduled to fly on the National Oceanic and Atmospheric Administration Geostationary Environmental Operational Satellite Series R (GOES-R) satellites].     

A fourier-transforming coded aperture

A Fourier-transforming coded aperture can be synthesized with a pair of two-dimensional detector arrays, each preceded by a properly designed sequence of two Gabor-zone plates. The coded image falling on one of the arrays corresponds to the cosine transform of the object. The coded image falling on the other array corresponds to the sine transform. Thus the Fourier transform of the object can be formed by using the first coded image as the real part, and the second coded image as the imaginary part, of the Fourier transform. Fourier-transforming coded apertures of this type are capable of producing better resolution than spatial-domain apertures. Although the system described in this article is specifically applied to a gamma-ray camera, such a system is generally applicable to a wide varioty of noncoherent imagers.©1993 John Wiley & Sons Inc     

Restholzhackschnitzel für die Herstellung von TMP und Zellstoff

Wood chips from industrial residues were produced using drum, disc and profile chippers, and dimension-fractionated using a slot and slit sieve. The different fractions F3, F4 and F5 were used either singly or in combination for the production of TMP and magnesium bisulfite pulp under laboratory conditions. The development of technological properties varied depending on the fraction-dimensions, with the F3-fraction yielding the best results. Technological properties of pulps from wood chips milled in profile chippers were generally better than those from disc and drum chippers. Micromorphological studies of the different wood chips demonstrated the extent of mechanical damage in tracheids, which occurred more frequently in smaller-dimensioned fractions. The fine structural morphology of TMP, pulp and control paper was correlated with important criteria for bonding properties during paper formation.     

Some investigations on ASAM pulping and chlorine free bleaching of eucalyptus from spain

In ASAM pulping of eucalyptus important process variables, such as methanol content of the cooking liquor kind of additional alkali source and alkali ratio were investigated. The pulping results were compared to those of kraft cooks carried out with identical raw material. In the bleaching trials the attention was focused on chlorine free sequences. The most meaningful advantage of ASAM pulping in comparison to the kraft process is the easy bleachability of the pulps. The good bleaching response allows the application of an absolutely chlorine free bleaching sequence, without excessively impairing pulp strength.     

Using the First-Level Caches as Filters to Reduce the Pollution Caused by Speculative Memory References

High-performance processors employ aggressive branch prediction and prefetching techniques to increase performance. Speculative memory references caused by these techniques sometimes bring data into the caches that are not needed by correct execution. This paper proposes the use of the first-level caches as filters that predict the usefulness of speculative memory references. With the proposed technique, speculative memory references bring data only into the first-level caches rather than all levels in the cache hierarchy. The processor monitors the use of the cache blocks in the first-level caches and decides which blocks to keep in the cache hierarchy based on the usefulness of cache blocks. It is shown that a simple implementation of this technique usually outperforms inclusive and exclusive baseline cache hierarchies commonly used by today’s processors and results in IPC performance improvements of up to 10% on the SPEC CPU2000 integer benchmarks.     

Behavioral tolerance to and withdrawal from multiple fluoxetine administration

The objective of this study was to characterize the lasting effects of fluoxetine on the locomotor behavior of rats using a computerized activity-monitoring system. Challenge dosages (8, 16, and 24 mg/kg i.p.) of fluoxetine 2 h into the dark phase resulted in dose-dependent suppression of locomotor activity for 4 h following injection. Escalating (10-30 mg/kg i.p.) semidaily fluoxetine administration for the next five days resulted in decreasing locomotor activity during the multiple-administration period relative to saline control. Circadian activity patterns at the conclusion of the regimen were unchanged in shape, but featured uniform decreases in locomotor activity at every hour which were more significant during the phase. Upon discontinuation, fluoxetine-treated rats showed a significant increase in activity during the first 4 h following the first "missed" dose which was not seen in subsequent washout. Ninety-six h after the final maintenance dose, the initial three dosages were readministered, and the locomotor activity suppression in response to the rechallenge dose of fluoxetine was significantly lessened compared to initial challenge. These findings suggest that tolerance and withdrawal were obtained.     

The role of endothelin-1 as a mediator of the pressure response after air embolism in blood perfused lungs

BACKGROUND: Irritable bowel syndrome is a common cause of abdominal pain and discomfort and may be related to disordered gastrointestinal motility. Our aim was to assess the effects of long-term treatment with a prokinetic agent, cisapride, on postprandial jejunal motility and symptoms in the irritable bowel syndrome (IBS). METHODS: Thirty-eight patients with IBS (constipation-predominant, n = 17; diarrhoea-predominant, n = 21) underwent 24-h ambulatory jejunal manometry before and after 12 week's treatment [cisapride, 5 mg three times daily (n = 19) or placebo (n = 19)]. RESULTS: In diarrhoea-predominant patients significant differences in contraction characteristics were observed between the cisapride and placebo groups. In cisapride-treated diarrhoea-predominant patients the mean contraction amplitude was higher (29.3 +/- 3.2 versus 24.9 +/- 2.6 mm Hg, cisapride versus placebo (P < 0.001); pretreatment, 25.7 +/- 6.0 mm Hg), the mean contraction duration longer (3.4 +/- 0.2 versus 3.0 +/- 0.2 sec, cisapride versus placebo (P < 0.001); pretreatment, 3.1 +/- 0.5 sec), and the mean contraction frequency lower (2.0 +/- 0.2 versus 2.5 +/- 0.4 cont./min, cisapride versus placebo (P < 0.001); pretreatment, 2.5 +/- 1.1 cont./min] than patients treated with placebo. No significant differences in jejunal motility were found in the constipation-predominant IBS group. Symptoms were assessed by using a visual analogue scale before and after treatment. Symptom scores relating to the severity of constipation were lower in cisapride-treated constipation-predominant IBS patients [score, 54 +/- 5 versus 67 +/- 14 mm, cisapride versus placebo (P < 0.05); pretreatment, 62 +/- 19 mm]. Diarrhoea-predominant IBS patients had a higher pain score after cisapride therapy [score, 55 +/- 15 versus 34 +/- 12 mm, cisapride versus placebo (P < 0.05); pretreatment, 67 +/- 19 mm]. CONCLUSION: Cisapride affects jejunal contraction characteristics and some symptoms in IBS.     

Increasing the Instruction Fetch Rate via Block-Structured Instruction Set Architectures

To exploit larger amounts of instruction level parallelism, processors are being built with wider issue widths and larger numbers of functional units. Instruction fetch rate must also be increased in order to effectively exploit the performance potential of such processors. Block-structured ISAs provide an effective means of increasing the instruction fetch rate. We define an optimization, called block enlargement, that can be applied to a block-structured ISA to increase the instruction fetch rate of a processor that implements that ISA. We have constructed a compiler that generates block-structured ISA code, and a simulator that models the execution of that code on a block-structured ISA processor. We show that for the SPECint95 benchmarks, the block-structured ISA improves the performance of an aggressive wide issue, dynamically scheduled processor by 15% while using simpler microarchitectural mechanisms to support wide issue and dynamic scheduling.     

Moderate-resolution imaging spectroradiometer ocean color polarization correction

The polarization correction for the Moderate-Resolution Imaging Spectroradiometer (MODIS) instruments on the Terra and Aqua satellites is described. The focus is on the prelaunch polarization characterization and on the derivation of polarization correction coefficients for the processing of ocean color data. The effect of the polarization correction is demonstrated. The radiances at the top of the atmosphere need to be corrected by as much as 3.2% in the 412 nm band. The effect on the water-leaving radiances can exceed 50%. The polarization correction produces good agreement of the MODIS Aqua water-leaving radiance time series with data from another, independent satellite-based ocean color sensor, the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS).     

Image and video disclosure of substance use on social media websites

The present study examines young adults’ use of social media websites, such as MySpace, Facebook, and YouTube, to post public images and videos of themselves depicting alcohol consumption, inebriated behavior, or recreational marijuana use. A content analysis revealed that the majority of image and video representations of alcohol consumption depicted females in social gatherings while images and videos depicting marijuana use depicted solitary males. Videos typically were viewed frequently and gained positive ratings. Among a sample of college students, one-third of participants reported having posted a picture depicting substance use on a social networking site, with 97% aware that others engage in this phenomenon. Students’ perceptions of alcohol-related postings were generally positive or seen as a matter of individual choice while marijuana-related postings were generally viewed more negatively.