The Mesozoic and Cenozoic motion of Adria (central Mediterranean): a review of constraints and limitations

This paper presents kinematic analysis on the motion of Adria, which is the continental mass that bridges Africa and Europe in the central Mediterranean. Palaeomagnetic data show a general coherence between the motion of Adria and Africa since the Late Paleozoic. This mutual motion, for the period from 120 Ma and the present, is verified by comparing inferred palaeolatitudes from relatively stable parts of Adria (Apulia, Gargano, Istria, and the Southern Alps) and the Hyblean Plateau, with latitudinal changes that are calculated from the motion of Africa with respect to hotspots. Additional constraints on the motion of Adria are provided from the Late Paleozoic-Early Mesozoic passive margin of Adria in the Ionian Sea. The seismic structure of the floor of the Ionian Sea resembles the structure of the oceanic crust in marginal back-arc basins, suggesting that it formed as a small ocean basin. Furthermore, the Ionian lithosphere in the Calabrian arc has been subjected to rapid rollback, which commonly occurs only when the subducting slab is made of oceanic lithosphere. This oceanic domain marks the Pennian-Triassic to Jurassic plate boundary between Adria and Africa, suggesting that a small amount of independent motion between Adria and Africa took place at that time. Since the Jurassic, Adria and Africa have shared a relatively coherent motion path. (C) 2004 Lavoisier SAS. All rights reserved.

Effect of sodium dodecylbenzene sulfonate on the motion of three-phase contact lines on the Wilhelmy plate surface

The combined approach of the molecular-kinetic and hydrodynamic theories for description of the motion of three-phase gas-liquid-solid contact lines has been examined using the Wilhelmy plate method. The whole dynamic meniscus has been divided into molecular, hydrodynamic, and static-like regions. The Young-Laplace equation and the molecular-kinetic and hydrodynamic dewetting theories have been applied to describe the meniscus profiles and contact angle. The dissipative forces accompanying the dynamic dewetting have also been investigated. The experiments with a Wilhelmy plate made from an acrylic polymer sheet were carried out using a computerized apparatus for contact angle analysis (OCA 20, DataPhysics, Germany). The extrapolated dynamic contact angle versus velocity of the three-phase contact line for Milli-Q water and 5 x 10(-4) M SDBS solution was experimentally obtained and compared with the combined MHD models with low and moderate Reynolds numbers. The models predict similar results for the extrapolated contact angle. SDBS decreases the equilibrium contact angle and increases the molecular jumping length but does not affect the molecular frequency significantly. The hydrodynamic deformation of the meniscus, viscous dissipation, and friction were also influenced by the SDBS surfactant. (c) 2005 Elsevier Inc. All rights reserved.

Prediction of impact forces in a vibratory ball mill using an inverse technique

To understand the dynamic mechanisms of the mechanical milling process in a vibratory mill, it is necessary to determine the characteristics of the impact forces associated with the collision events. However, it is difficult to directly measure the impact force in an operating mill. This paper describes an inverse technique for the prediction of impact forces from acceleration measurements on a vibratory ball mill. The characteristics of the vibratory mill have been investigated by the modal testing technique, and its system modes have been identified. In the modelling of the system vibration response to the impact forces, two modal equations have been used to describe the modal responses. The superposition of the modal responses gives rise to the total response of the system. A method based on an optimisation approach has been developed to predict the impact forces by minimising the difference between the measured acceleration of the vibratory ball mill and the predicted acceleration from the solution of the modal equations. The predicted and measured impact forces are in good agreement. Copyright (C) 1996 Elsevier Science Ltd.

Supersaturated solutions evaluated with an in vitro stratum corneum tape stripping technique

The flux of a compound across a membrane from any formulation, whether it contains penetration enhancers or not, is limited by its saturated solubility in the vehicle. Under such conditions the concentration of the permeant in the outer layers of the stratum corneum is also saturated. Consequently, when the permeation of a drug from a supersaturated solution leads to enhanced penetration, the concentration of the drug in the outer layers of the membrane is also supersaturated. Therefore, the stratum corneum may possess antinucleant properties which inhibit or retard the crystallisation process. In this study, the enhanced in vitro permeation of supersaturated solutions of piroxicam across human skin in diffusion cells was demonstrated. The amount of permeant in the stratum corneum was determined using a tape stripping technique. Supersaturated solutions up to four degrees of saturation were investigated which produced a linear relationship between the degree of saturation and the amount of piroxicam in the stratum corneum (R-2 = 0.970). Furthermore, the amount of piroxicam in the viable layers of the skin also increased with increasing degree of saturation. An analysis of the results suggested that enhanced penetration across human skin from supersaturated solutions of piroxicam may occur as a result of the antinucleating ability of the intercellular lipids of the stratum corneum. (C) 1997 Elsevier Science B.V.

Molecular motion in miscible polymer blends .1. Motion in blends of PEO and PVPh studied by solid-state C-13 T-1 rho measurements

Changes in molecular motion in blends of PEO-PVPh have been studied using measurements of C-13 T-1 rho relaxation times. C-13 T-1 rho relaxation has been confirmed as arising from spin-lattice interactions by observation of the variation in T-1 rho with rf field strength and temperature. In the pure homopolymers a minimum in T-1 rho is observed at ca. 50 K above the glass transition temperatures detected by DSC. After blending, the temperature of the minimum in T-1 rho for PEO increased, while that for PVPh decreased, however, the minima, which correspond to the temperatures where the average correlation times for reorientation are close to 3.1 mu s, are separated by 45 K (in a 45% PEO-PVPh blend). These phenomena are explained in terms of the local nature of T-1 rho measurements. The motions of the individual homopolymer chains are only partially coupled in the blend. A short T-1 rho has been observed for protonated aromatic carbons, and assigned to phenyl rings undergoing large-angle oscillatory motion, The effects of blending, and temperature, on the proportion of rings undergoing oscillatory motion are analyzed.

Non-expression of insulin-like growth factor-I receptor is associated with apoptosis: an ultrastructural study on rat ameloblasts

Insulin-like growth factor-I (IGF-I) is a preiotrophic polypeptide which appears to have roles both as a circulating endocrine hormone and as a locally synthesized paracrine or autocrine tissue factor. IGF-I plays a major role in regulating the growth of cells in vivo and in vitro and initiates metabolic and mitogenic processes in a wide variety of cell types by binding to specific type I receptors in the plasma membrane, In this study, we report the distribution of IGF-I receptors in odontogenic cells at the ultrastructural level using the high resolution protein A-gold technique, In the pre-secretory stage, very little gold label was visible over the ameloblasts and odontoblasts, During the secretory stage the label was mostly seen in association with the cell membranes and endoplasmic reticulum of the ameloblasts. Lysosome-like elements in the post-secretory stage were labelled as well as multivesicular dense bodies, Very little labelling was encountered in the ameloblasts in the transitional stage, where apoptotic bodies were clearly visible, The maturation stage also exhibited labelling of the secretory-like granules in the distal surface. The presence of gold particles over the plasma membrane is an indication that IGF-I receptor is a membrane-bound receptor. Furthermore, the intracellular distribution of the label over the endoplasmic reticulum supports the local synthesis of the IGF-I receptor. The absence of labelling over the transitional ameloblasts suggests that the transitional stage may require the non-expression of IGF-I as a prerequiste or even a trigger for apoptosis.

Cervical range of motion discriminates between asymptomatic persons and those with whiplash

Study Design. A comparative study of cervical range of motion in asymptomatic persons and those with whiplash. Objectives. To compare the primary and conjunct ranges of motion of the cervical spine in asymptomatic persons and those with persistent whiplash-associated disorders, and to investigate the ability of these measures of range of motion to discriminate between the groups. Summary of Background. Evidence that range of motion is an effective indicator of physical impairment in the cervical spine is not conclusive. Few studies have evaluated the ability to discriminate between asymptomatic persons and those with whiplash on the basis of range of motion or compared three-dimensional in vivo measures of range of motion in asymptomatic persons and those with whiplash-associated disorders. Methods. The study participants were 89 asymptomatic volunteers (41 men, 48 women; mean age 39.2 years) and 114 patients with persistent whiplash-associated disorders (22 men, 93 women; mean age 37.2 years) referred to a whiplash research unit for assessment of their cervical region. Range of cervical motion was measured in three dimensions with a computerized, electromagnetic, motion-tracking device. The movements assessed were flexion, extension, left and right lateral flexion, and left and right rotation. Results. Range of motion was reduced in all primary movements in patients with persistent whiplash-associated disorder. Sagittal plane movements were proportionally the most affected. On the basis of primary and conjunct range of motion, age, and gender, 90.3% of study participants could be correctly categorized as asymptomatic or as having whiplash (sensitivity 86.2%, specificity 95.3%). Conclusions. Range of motion was capable of discriminating between asymptomatic persons and those with persistent whiplash-associated disorders.

A technique for preserving pigmentation in some capsalid monogeneans for taxonomic purposes

A technique is described to preserve the pigment found in the bodies and the intestine of some brightly coloured and darkly pigmented benedeniine capsalid monogeneans. Previous studies of these pigmented capsalids have proven difficult because the pigmentation usually disappears when the worms are fixed using preservatives containing concentrations of formalin over 5% and/or ethanol, acetic acid, chromic acid, picric acid and mercuric chloride. The technique developed here uses a fixative comprising glycerol, acetone and formalin (GAF). After fixation under light coverslip compression for three minutes, specimens are transferred to absolute acetone for three minutes and cleared in a mixture of nine parts cedar wood oil and one part absolute acetone before mounting in Canada balsam. Processing must be carried out quickly, as these chemicals will cause the pigments to fade if the specimens are exposed to them for too long. Pigmented benedeniines processed using this technique retain the distribution, intensity and colour observed in live worms. The colour and distribution of pigmentation in monogeneans may be of taxonomic importance and this technique aids preparation of whole-mounts suitable for registration as type-material.

Automated edge-detection technique for measurement of brachial artery reactivity: A comparison of concordance with manual measurements

Concerns have been raised about the reproducibility of brachial artery reactivity (BAR), because subjective decisions regarding the location of interfaces may influence the measurement of very small changes in lumen diameter. We studied 120 consecutive patients with BAR to address if an automated technique could be applied, and if experience influenced reproducibility between two observers, one experienced and one inexperienced. Digital cineloops were measured automatically, using software that measures the leading edge of the endothelium and tracks this in sequential frames and also manually, where a set of three point-to-point measurements were averaged. There was a high correlation between automated and manual techniques for both observers, although less variability was present with expert readers. The limits of agreement overall for interobserver concordance were 0.13 +/-0.65 mm for the manual and 0.03 +/-0.74 mm for the automated measurement. For intraobserver concordance, the limits of agreement were -0.07 +/-0.38 mm for observer 1 and -0.16 +/-0.55 mm for observer 2. We concluded that BAR measurements were highly concordant between observers, although more concordant using the automated method, and that experience does affect concordance. Care must be taken to ensure that the same segments are measured between observers and serially.

Effect of tissue Doppler on the accuracy of novice and expert interpreters of Dobutamine echocardiography

The subjective interpretation of dobutamine echocardiography (DBE) makes the accuracy of this technique dependent on the experience of the observer, and also poses problems of concordance between observers. Myocardial tissue Doppler velocity (MDV) may offer a quantitative technique for identification of coronary artery disease, but it is unclear whether this parameter could improve the results of less expert readers and in segments with low interobserver concordance. The aim of this study was to find whether MDV improved the accuracy of wall motion scoring in novice readers, experienced echocardiographers, and experts in stress echocardiography, and to identify the optimal means of integrating these tissue Doppler data in 77 patients who underwent DBE and angiography. New or worsening abnormalities were identified as ischemia and abnormalities seen at rest as scarring. Segmental MDV was measured independently and previously derived cutoffs were applied to categorize segments as normal or ab normal. Five strategies were used to combine MDV and wall motion score, and the results of each reader using each strategy were compared with quantitative coronary angiography. The accuracy of wall motion scoring by novice (68 +/- 3%) and experienced echocardiographers (71 +/- 3%) was less than experts in stress echocardiography (88 +/- 3%, p < 0.001). Various strategies for integration with MDV significantly improved the accuracy of wall motion scoring by novices from 75 +/- 2% to 77 +/- 5% (p < 0.01). Among the experienced group, accuracy improved from 74 +/- 2% to 77 +/- 5% (p < 0.05), but in the experts, no improvement was seen from their baseline accuracy. Integration with MDV also improved discordance related to the basal segments. Thus, use of MDV in all segments or MDV in all segments with wall motion scoring in the apex offers an improvement in sensitivity and accuracy with minimal compromise in specificity. (C) 2001 by Excerpta Medica, Inc.