[1] Solar radiation assessment by satellite is constrained by physical limitations of imagery and by the accuracy of instantaneous local atmospheric parameters, suggesting that one should use simplified but physically consistent models for operational work. Such a model is presented for use with GOES 8 imagery applied to atmospheres with low aerosol optical depth. Fundamental satellite-derived parameters are reflectance and cloud cover. A classification method applied to a set of images shows that reflectance, usually defined as upper-threshold R max in algorithms assessing cloud cover, would amount $0.465, corresponding to the transition between a cumuliform and a stratiform cloud field. Ozone absorption is limited to the stratosphere. The model considers two spectral broadband intervals for tropospheric radiative transfer: ultraviolet and visible intervals are essentially nonabsorbing and can be processed as a single interval, while near-infrared intervals have negligible atmospheric scattering and very low cloud transmittance. Typical values of CO 2 and O 3 content and of precipitable water are considered. A comparison of daily values of modeled mean irradiance with data of three sites (in rural, urban industrial, and urban coastal environments), September-October 2002, exhibits a bias of +5 W m À2 and a standard deviation of $15 W m À2 (0.4 and 1.3 MJ m À2 for daily irradiation). A comparison with monthly means from about 80 automatic weather stations (covering a large area throughout the Brazilian territory) still shows a bias generally within ±10 W m À2 and a low standard deviation (<20 W m À2 ), but the bias has a trend in September-December 2002, suggesting an annual cycle of local R max values. Systematic (mean) errors in partial cloud cover and in nearly clear-sky situations may be enhanced using regional values for atmospheric and surface parameters, such as precipitable water, R max , and ground reflectance. The larger errors are observed in situations of high aerosol load (especially in regions with industrial activity or forest or agricultural fires). The last case is evident when sites in the Amazonian region or São Paulo city are selected. When considering daily values averaged within 2.5°Â 2.5°cells, the standard error is lower than 20 W m À2 ; present results suggest an annual cycle of mean bias ranging from +10 to À10 W m À2 , with an amplitude of $10 W m À2 . These values are close to the proposed requirements of 10 W m À2 for the mean deviation and 25 W m À2 for the standard deviation. It is expected that the introduction of a reference grid containing mean values of parameters within a cell could induce a decrease in the standard deviation of mean errors and the correction of their annual cycle. A model adaptation for assessing the effect of high aerosol loads is needed in order to extend improvements to the whole Brazilian area.

We are concerned with the initial-boundary problem associated to the Korteweg de Vries Kawahara perturbed by a dispersive term which appears in several fluids dynamics problems. We obtain local smoothing effects that are uniform with respect to the size of the interval. We also propose a simple finite different scheme for the problem and prove its unconditional stability. Finally we give some numerical examples.

The regional Eta workstation (WS) model with horizontal resolution of 40 km has been integrated over South America for January 2003. The NCEP-DOE Reanalysis II was used for initial and lateral boundary conditions. The comparison of the model-simulated and satellite-derived values of monthly mean incident solar radiation at the surface demonstrates that the former values are larger by 20%-30% over the entire region. To improve the surface flux representation in the model, a new solar radiation scheme has been implemented in it. An offline comparison of the original and the new radiation schemes with the detailed line-by-line method demonstrates a higher accuracy for the new scheme. With the new scheme, the modelsimulated incident solar radiation at the surface is in a better agreement with the satellite-derived data. Nevertheless, a noticeable systematic difference of 10%-20% still remains, probably because of the incorrect description of cloud parameters in the model. The lower incident solar radiation in the new version of the model causes a decrease of near-surface air temperature by 0.1°-1°C and a decrease of precipitation rate by up to 20%-30% over most of the continent. The increase in the simulated incident solar radiation and temperature is found in the region of the South Atlantic convergence zone, which is responsible for the enhanced cloudiness and precipitation in the central and southeastern parts of Brazil during summer. The model results are compared with observational data of meteorological stations, the Global Precipitation Climatology Project (GPCP), and the South American Low-Level Jet Experiment (SALLJEX) and are discussed.

ABSTRACT. This work describes ultraviolet-B albedo measurements performed over several surfaces and different atmospheric conditions. These results provide a complement to previous studies as Blumthaler & Ambach (1988), widely used as albedo reference for the main UV radiative transfer models. A custom-built albedometer composed of a pair of Solarlight UVB501 biometer was used to measure the albedo over the following surfaces: green and yellowish grass, sand, wood (natural and painted), formica (synthetic plate), and iron. Influence of clouds and the sensor's response to temperature variations are also discussed. Presence of clouds on surface albedo measurement seems negligible, but a thermo-regulated instrument is indispensable to an accurate analysis. Comparison with previous works shows the need for studies on the detailed characterization of the type of surface.Keywords: surface albedo, ultraviolet radiation, radiative transfer models. RESUMO.Este trabalho apresenta medidas de albedo UVB realizadas sobre diferentes tipos de superfície e condições atmosféricas. Tais resultados fornecem uma contribuição a trabalhos prévios, tais como Blumthaler & Ambach (1988) amplamente utilizado em modelos de transferência radiativa. Para tanto, um albedômetro foi construído a partir de dois biômetros Solarlight UVB501 e as medidas foram realizadas sobre as seguintes superfícies: grama verde e amarelada, areia, madeira (natural e pintada), fórmica e metal. Ao contrário de outras publicações sobre o assunto, a influência de nuvens e a resposta do sensoràs variações de temperatura foram discutidas com maior profundidade. Verificou-se, que as nuvens não exercem influência significativa sobre a determinação do albedo, enquanto o uso de sensores termo reguladosé imprescindível para a obtenção de medidas precisas. Além disso, o trabalho demonstra a necessidade da realização de estudos que detalhem as superfícies estudadas de maneira mais aprofundada.Palavras-chave: albedo de superfície, radiação ultravioleta, modelos de transferência de radiação.

No abstract

To evaluate the safety and efficacy of lotilaner ophthalmic solution, 0.25% for the treatment of blepharitis due to Demodex infestation compared to vehicle control. Methods: In this phase II, randomized, controlled, double-masked clinical trial, 60 eligible participants with Demodex blepharitis were randomly assigned in a 1:1 ratio to receive either topical lotilaner ophthalmic solution, 0.25% (Tarsus Pharmaceuticals, Inc., Irvine, CA) (study group) or the vehicle without lotilaner (control group) bilaterally twice a day for 28 days. Participants were followed at Days 7, 14, 28, 60 and 90. The efficacy parameters were change in collarette grade and Demodex density at Day 28. Safety parameters were adverse events, changes in corrected distance visual acuity (CDVA), intraocular pressure (IOP) and slit-lamp biomicroscopy.Results: The study group showed a statistically significant decrease in collarette grade compared to the control group beginning at Day 14 (p = 0.003) in the upper eyelid and at Day 28 (p = 0.003) in the lower eyelid. Decreases in both lids were maintained through Day 90 (p < 0.001). At Day 28, mite eradication was achieved in 66.7% and 25.9% of eyes in the study and control group (p = 0.005); at Day 90, these proportions were 68.2% and 18.5% (p = 0.001), respectively. No serious adverse events or clinically significant changes in CDVA and IOP were observed. Conclusion: For Demodex blepharitis, treatment with lotilaner ophthalmic solution, 0.25% for 4 weeks is safe and effective. The improvement in collarette grade and mite density observed during the treatment period persisted for at least two months following treatment cessation.

Purpose: To evaluate the efficacy of topical lotilaner ophthalmic solution, 0.25%, in patients with Demodex blepharitis. Methods: Eighteen adults with Demodex blepharitis, defined as >10 collarettes on the upper lid and/or mite density of ‡1.5 mites per lash (upper and lower), were treated bid for 42 days with the topical lotilaner ophthalmic solution, 0.25%. Contact lens wear, artificial eyelashes, and lid structural abnormalities were among the exclusion criteria. No other antibacterial, antiparasitic, or anti-inflammatory treatment or lid hygiene products were permitted. One eye of each patient was selected for analysis and assessed on day 7, 14, 28, and 42. Collarettes were graded at each visit, and mite density was evaluated by microscopy at each visit except day 7. Outcome measures were collarette elimination (£2 lashes with collarettes) and mite eradication (0 mites). Drop tolerability, adverse events, visual acuity, and slit-lamp biomicroscopy were assessed. Results: Collarette elimination was achieved in 13/18 participants (72.2%) by day 42. Mean collarette grade (upper lid) declined from 3.56 -0.17 to 0.28 -0.11. Mite eradication was achieved in 14/18 participants (77.8%) by day 42. Mean mite density decreased from 2.63 -0.39 to 0.12 -0.08 mites/lash. Participants reported good tolerability. Adverse events were mild and transient and did not result in treatment discontinuation. Conclusion: Six weeks of at-home topical therapy with the lotilaner ophthalmic solution, 0.25%, was effective in eliminating the most common objective signs of Demodex blepharitis, with a collarette elimination rate of 72% and mite eradication in 78% of eyes by day 42. ISRCTN registration #: 24398865

Purpose. Evaluate safety and efficacy of topical lotilaner ophthalmic solution, 0.25% for the treatment of Demodex blepharitis. Patients and Methods. 15 patients with Demodex blepharitis, defined as >10 collarettes on the upper lid, lid margin erythema, and Demodex density of ≥1.5 mites/lash on microscopy, were treated bid for 28 days with lotilaner ophthalmic solution, 0.25%. Contact lens wear, artificial eyelashes, and lid structural abnormalities were among the exclusion criteria. No other antibacterial, antiparasitic, or anti-inflammatory treatment or lid hygiene products were permitted. Patients were assessed on Days 7, 14, 28, 60, and 90. Outcome measures were changes in collarette grade and mite density on Day 28. Adverse events and changes in intraocular pressure (IOP), corrected distance visual acuity (CDVA), and slit-lamp biomicroscopy were assessed. Results. Mean collarette grade (upper lids) improved from 3.07 ± 0.21 to 0.79 ± 0.19 on Day 28; the change was statistically significant for both upper and lower lids from Day 14 on. Mean mite density per lash decreased from 2.28 ± 0.16 at baseline to 0.14 ± 0.05 at Day 28 p < 0.0001 . Mite eradication (0 mites) was documented in 57.1% of eyes. The effects were durable through Day 90. There were no adverse events and little to no change in CDVA or IOP. The drop was well tolerated, with no discontinuations due to ocular irritation. Conclusion. Topical lotilaner ophthalmic solution, 0.25% for 4 weeks, showed promising efficacy for the treatment of Demodex blepharitis. This novel treatment appears to be safe and well tolerated. Randomized controlled studies are needed to confirm the results.