Cirrus cloud optical and microphysical property retrievals from eMAS during SEAC4RS using bi-spectral reflectance measurements within the 1.88 µm water vapor absorption band.

Previous bi-spectral imager retrievals of cloud optical thickness (COT) and effective particle radius (CER) based on the Nakajima and King (1990) approach, such as those of the operational MODIS cloud optical property retrieval product (MOD06), have typically paired a non-absorbing visible or near-infrared wavelength, sensitive to COT, with an absorbing shortwave or midwave infrared wavelength sensitive to CER. However, in practice it is only necessary to select two spectral channels that exhibit a strong contrast in cloud particle absorption. Here it is shown, using eMAS observations obtained during NASA's SEAC4RS field campaign, that selecting two absorbing wavelength channels within the broader 1.88 µm water vapor absorption band, namely the 1.83 and 1.93 µm channels that have sufficient differences in ice crystal single scattering albedo, can yield COT and CER retrievals for thin to moderately thick single-layer cirrus that are reasonably consistent with other solar and IR imager-based and lidar-based retrievals. A distinct advantage of this channel selection for cirrus cloud retrievals is that the below-cloud water vapor absorption minimizes the surface contribution to measured cloudy TOA reflectance, in particular compared to the solar window channels used in heritage retrievals such as MOD06. This reduces retrieval uncertainty resulting from errors in the surface reflectance assumption, as well as reduces the frequency of retrieval failures for thin cirrus clouds.

Systemic absorption of insulin and glucagon applied topically to the eyes of rats and a diabetic dog.

Nondiabetic rats were anesthetized with xylazine/ketamine to induce hyperglycemia and systemic insulin absorption from eyedrops formulated with dodecylmaltoside was quantitated by both a decrease in serum levels of D-glucose and an increase in immunoreactive insulin levels. When insulin eyedrop administration was delayed until 60 minutes after the administration of eyedrops containing 0.25% dodecylmaltoside, the enhanced systemic absorption of insulin was maintained, suggesting that dodecylmaltoside had an effect directly on the permeability of the nasal sinus epithelium. When glucagon was formulated in eyedrops or nosedrops containing dodecylmaltoside, systemic absorption of glucagon could be measured in the form of an increase in the serum D-glucose concentration following nasal application, but not after ocular application. Eyedrops containing insulin plus 0.125% dodecylmaltoside were administered to a diabetic dog; a dose of 20 units of regular insulin caused a modest decrease in serum D-glucose concentration and a concomitant increase in serum immunoreactive insulin content. These results provide evidence that peptide drugs such as insulin can be formulated in eyedrops with low concentrations of dodecylmaltoside, a mild nonionic surfactant.