Single stratum

In an influential paper in Biometrika, Rosenbaum and Rubin discussed the possibility of using what they called the propensity score for adjusting for confounders (Rosenbaum and Rubin, 1983). The idea is that a stratification be made on the probability of assignment to treatment or control as a function of covariates. In a classic randomized clinical trial, of course, the probability of assignment to either group is 1 /2 irrespective of any covariate. The philosophy of the propensity score would then be that there is but a single stratum, that with score 1/2, and so no adjustment is necessary. This is, of course, equivalent to the familiar argument that for a classic randomized trial no adjustment is necessary. 

The epithelial layer is a single stratum of epithelial cells which is adjacent to the anmiotic flnid. These cells contain microvilli attachments that regulate the amni-otic fluid, much like a synovial lining. These epithelial cells contain growth factors, prostaglandins, vasoactive peptides, cytokines, and extracellular proteins. This layer serves as a covering epithelium, active secretory function, and intercellular transport. 

Drilled well in shell and auger borehole with standpipe covering single stratum... 

The value of S0 decreases with increasing elevation. Zao, the interface between air and the LNAPL phase, may or may not coincide with Zu, the upper boundary of the aquifer. Typically, the saturation of the LNAPL phase extends over two distinct regions (see Figure 5.10). These are (1) water and LNAPL phase zone, and (2) water, LNAPL phase, and air zone. When a single homogeneous stratum is considered, O can be assumed constant. In a stratified medium, however, saturation discontinuities generally exist due to the variation in soil characteristics, and the determination of LNAPL volume based on Equation 6.22 may become much more involved. 

Of particular interest are membranes prepared of an inert porous support carrying natural or artificial lipids. These coatings may comprise a single component, such as isopropylmyristate or dodecanol [99, 106], or mixtures of comparable composition as the stratum corneum intercellular bilayer [107, 108], Usually, synthetic lipids are used, due to an elaborate isolation procedure for stratum corneum lipids, with limited yield and the necessity of separation of triglycerides, originating from subcutaneous fatty tissue or skin care products [109],... 

Drug levels within the stratum corneum can be assessed by sampling single corneocyte layers with adhesive film. The drug is then extracted from the tape-strips and quantified by a suitable analytical method. Usually, scintillation counting (for radioactive compounds) or high performance liquid... 

The success of the Potts-Guy equation led many authors to advocate a single mechanism as the rate determining step for permeation through the skin barrier for all or at least a wide range of solutes diffusion was assumed to occur primarily via the interkeratinocyte lipids of the stratum corneum, a mixture of ceramides, fatty acids, and sterols. While from a macroscopic point of view these lipids may be modeled as a bulk solvent, on a microscopic scale they... 

For parallel permeation pathways within a single layer of such a laminate, the total permeability may be calculated as the sum of the permeabilities [49], For example, when assuming that permeation may occur through both a lipid fraction and a protein fraction of the stratum corneum, the total permeability is calculated according to Eq. 34 ... 

While Heisig et al. solved the diffusion equation numerically using a finite volume method and thus from a macroscopic point of view, Frasch took a mesoscopic approach the diffusion of single molecules was simulated using a random walk [69], A limited number of molecules were allowed moving in a two-dimensional biphasic representation of the stratum corneum. The positions of the molecules were changed with each time step by adding a random number to each of the molecule s coordinates. The displacement was related... 

Hippocampal slices (400-500 frm) were quickly prepared from male Wistar rats (8- to 9-weeks-old) and maintained in a chamber at 35 °C, where they were continuously perfused with artificial cerebrospinal fluid as described in our previous paper [11]. A bipolar tungsten electrode was placed in the stratum radiatum to stimulate Schaffer collateral and commissural afferents. The evoked potential was extracellularly recorded from the pyramidal cell layer of the CA1 subfield with a glass capillary microelectrode. A single test stimulation (0.05 msec duration) was applied at intervals of 30 sec. Drugs were delivered by perfusion. To induce potentiation of the evoked potentials, tetanic stimulation was applied at the same intensity through the same stimulating electrode as used for the test stimulation. The magnitude of LTP was evaluated by the population spike amplitude 30 min after tetanic stimulation. 

The innermost layer of the epidermis, the stratum basale, consists of a single layer of columnar-shaped, undifferentiated stem cells. Mitosis of these cells constantly renews the epidermis and this proliferation compensates for the loss of dead stratum corneum cells (corneocytes) from the skin surface. As the cells produced by the basal layer move upward, they alter morphologically as well as histochemically to form the outermost layer, the stratum corneum. Over a 4- to 5-week period the entire epidermis is renewed [5]. 

Stratum basale is a single layer composed of stem cells and their derivative cells. It is attached to the basement membrane by hemidesmo-somes.48 The cells in this layer are columnar or cuboidal in shape and characterized by large nuclei (high nuclear-cytoplasmic ratio) and keratin filaments (tonofilaments). The basal layer contains keratins K14 and K15, melanocytes (which are pigment-forming cells), Langerhans... 

Figure 10 Stratum corneum sections after ruthenium tetroxide fixation confirmed these results (see Figure 9(d) for dodecyl-azone [A] and Figure 9(f) for oleyl-azone [B]). Bar represents 100 nm. C, corneocyte D, desmosome SL, single lamellae. 

Norlen, L., Does the single gel phase exist in stratum corneum Reply. To the editor, J. Invest. Dermatol., 118, 899, 2002. 

Lipid Organization of the Stratum Comeum Intercellular Space — A Single and... 

The Zn content of the uninvolved psoriatic skin is increased in the stratum spinosum especially, except in one single section where the Zn follows suit with Fe distribution. Such variations are likely to occur as a function of the cell cycle position of a particular cell. 

Kretzoi (1956) concludes that this fauna represents the youngest stratum of Villany, with a single Allophaiomys in its cover. He did not consider that the yellowish colour of the sediment was accompanied by a change in fauna due to climatic factors. However, as we have seen already with locality no. 3 of Osztramos, considerable changes in climate have to be taken into account. 

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