Dynamic characteristics of observed sudden warmings

The planetary wave dynamics of stratospheric sudden warmings in the Northern Hemisphere for a large number of observed events that occurred during winters from 1970 to 1975 and 1978 to 1981 are investigated. The analysis describes wave propagation and zonal flow interaction from the troposphere upwards to near 50 km, and in some years to near 80 km. Three primary topics are covered here: (1) the interaction of zonally propagating and quasi-stationary planetary waves during warming events; (2) planetary wave influence on zonal flow near the stratopause; and (3) planetary wave propagation to near 80 km as seen from Stratospheric and Mesospheric Sounder (SAMS) data

Periodic variations in stratospheric meridional wind from 20-65 km, at 80 deg N to 8 deg S

The variability of stratospheric meridional winds is examined in both space and time. Height-latitude sections for January along 70 deg E and 90 deg W show a divergence zone above 50 km near 60 deg N and an intense convergence zone 40 km near 50 deg N over North America. This latter structure, with southward winds in the Arctic and northward winds at mid-latitudes over North America, persists from October through April. Tidal winds dominate all other circulation features in summer at all latitudes, and throughout the year at low latitudes. To help understand the observed patterns of variability, long-term periodic features are analyzed. The quasi-biennial oscillation, annual wave, and four-month wave have amplitudes of about 10, 20, and 10 m/sec respectively in the Arctic near 45 km. The phase of the annual wave changes by nearly 180 deg in a narrow zone near 45 deg N. The semiannual wave has an amplitude of 10 m/sec. 50 deg N above 50 km equinoctial phase dates in the region of maximum amplitude. This polar semiannual wave corresponds closely to that previously found in the zonal wind

An investigation of the time series of visibility and precipitation intensity fluctuations

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1961.Includes bibliographical references (leaf 91).by Gilbert D. Brinckerhoff and Denis G. Dartt.M.S

Development of Conjunctival Goblet Cells and Their Neuroreceptor Subtype Expression

PURPOSE. To investigate expression of muscarinic, cholinergic, and adrenergic receptors on developing conjunctival goblet cells. METHODS. Eyes were removed from rats 9 to 60 days old, fixed, and used for microscopy. For glycoconjugate expression, sections were stained with Alcian blue/periodic acid-Schiff's reagent (AB/PAS) and with the lectins Ulex europeus agglutinin I (UEA-I) and Helix pomatia agglutinin (HPA). Goblet cell bodies were identified using anti-cytokeratin 7 (CK7). Nerve fibers were localized using anti-protein gene product 9.5. Location of muscarinic and adrenergic receptors was investigated using anti-muscarinic and ␤-adrenergic receptors. RESULTS. At days 9 and 13, single apical cells in conjunctival epithelium stained with AB/PAS, UEA-I, and CK7. At days 17 and 60, increasing numbers of goblet cells were identified by AB/PAS, UEA-I, HPA, and CK7. Nerve fibers were localized around stratified squamous cells and at the epithelial base at days 9 and 13, and around goblet cells and at the epithelial base at days 17 and 60. At days 9 and 13, M 2 -and M 3 -muscarinic and ␤ 2 -adrenergic receptors were found in stratified squamous cells, but M 1 -muscarinic and ␤ 1 -adrenergic receptors were not detected. At days 17 and 60, M 2 -and M 3 -muscarinic receptors were found in goblet cells, whereas M 1 -muscarinic receptors were in stratified squamous cells. ␤ 1 -and ␤ 2 -Adrenergic receptors were found on both cell types. ␤ 3 -Adrenergic receptors were not detected. CONCLUSIONS. In conjunctiva, nerves, M 2 -and M 3 -muscarinic, and ␤ 1 -and ␤ 2 -adrenergic receptors are present on developing goblet cells and could regulate secretion as eyelids open. (Invest Ophthalmol Vis Sci. 2000;41:2127-2137 T he tear film mucus layer consists of high molecular weight glycoconjugates including mucins, which are secreted mainly by conjunctival goblet cells. This layer plays an important role in protecting the ocular surface from exogenous agents (bacterial or chemical) and provides lubrication during all types of eye movements. 1 Goblet cells can release their secretory granules in a reflex response mediated by the activation of either parasympathetic or sympathetic nerves that surround them. 2,3 Previous reports from this laboratory showed the localization of nerve fibers adjacent to goblet cells in rat conjunctiva. 5 Use of immunofluorescence techniques demonstrated that M 2 -and M 3 -, but not M 1 -muscarinic acetylcholine receptors (MAchRs), are present on goblet cells and are located on membranes subjacent to secretory granules. VIP type 2 receptors (VIPR2s) are located in the basolateral membranes of goblet cells. 3 Although the role of the sympathetic agonists in stimulating goblet cell secretion is unknown, ␤ 1 -and ␤ 2 -adrenergic receptor (␤AR) subtypes appear to be present in goblet cells as well as in stratified squamous cells. Morphologic studies in developing conjunctiva suggest that based on changes in the acidity of glycoproteins in the secretory granules, goblet cells may differentiate from basal epithelial cells in the forniceal zone. 7 Watanabe et al

Immunolocalisation of P2Y receptors in the rat eye

Nucleotides present an important role in ocular physiology which has been demonstrated by recent works that indicate their involvement in many ocular processes. P2Y are important among P2 receptors since they can control tear production, corneal wound healing, aqueous humour dynamics and retinal physiology. Commercial antibodies have allowed us to investigate the distribution of P2Y receptors in the cornea, anterior and posterior chamber of the eye and retina. The P2Y1 receptor was present mainly in cornea, ciliary processes, and trabecular meshwork. The P2Y2 receptors were present in cornea, ciliary processes and retinal pigmented epithelium. P2Y4 was present in cornea, ciliary processes, photoreceptors, outer plexiform layer and ganglion cell layer. The P2Y6 presented almost an identical distribution as the P2Y4 receptor. The P2Y11 was also detectable in the retinal pigmented epithelium. The detailed distribution of the receptors clearly supports the recent findings indicating the relevant role of nucleotides in the ocular function

Pooling job physical exposure data from multiple independent studies in a consortium study of carpal tunnel syndrome

Pooling data from different epidemiological studies of musculoskeletal disorders (MSDs) is necessary to improve statistical power and to more precisely quantify exposure–response relationships for MSDs. The pooling process is difficult and time-consuming, and small methodological differences could lead to different exposure–response relationships. A subcommittee of a six-study research consortium studying carpal tunnel syndrome: (i) visited each study site, (ii) documented methods used to collect physical exposure data and (iii) determined compatibility of exposure variables across studies. Certain measures of force, frequency of exertion and duty cycle were collected by all studies and were largely compatible. A portion of studies had detailed data to investigate simultaneous combinations of force, frequency and duration of exertions. Limited compatibility was found for hand/wrist posture. Only two studies could calculate compatible Strain Index scores, but Threshold Limit Value for Hand Activity Level could be determined for all studies. Challenges of pooling data, resources required and recommendations for future researchers are discussed