The effects of skin-to-skin contact during acute pain in preterm newborns

Background and purpose: Several promising non-pharmacological interventions have been developed to reduce acute pain in preterm infants including skin-to-skin contact between a mother and her infant. However, variability in physiological outcomes of existing studies on skin-to-skin makes it difficult to determine treatment effects of this naturalistic approach for the preterm infant. The aim of this study was to test the efficacy of mother and infant skin-to-skin contact during heel prick in premature infants. Method: Fifty nine stable preterm infants (born at least 30 weeks gestational age) who were undergoing routine heel lance were randomly assigned to either 15 min of skin-to-skin contact before, during and following heel prick (n = 31, treatment group), or to regular care (n = 28, control group). Throughout the heel lance procedure, all infants were assessed for change in facial action (NFCS), behavioral state, crying, and heart rate. Results: Statistically significant differences were noted between the treatment and control groups during the puncture, heel squeeze and the post phases of heel prick. Infants who received skin-to-skin contact were more likely to show lower NFCS scores throughout the procedure. Both groups of infants cried and showed increased heart rate during puncture and heel squeeze although changes in these measures were less for the treated infants. Conclusions: Skin-to-skin contact promoted reduction in behavioral measures and less physiological increase during procedure. It is recommended that skin-to-skin contact be used as a non-pharmacologic intervention to relieve acute pain in stable premature infants born 30 weeks gestational age or older. (C) 2007 European Federation of Chapters of the International Association for the Study of Pain. Published by Elsevier Ltd. All rights reserved.

Non-linear boundary element formulation applied to contact analysis using tangent operator

This work presents a non-linear boundary element formulation applied to analysis of contact problems. The boundary element method (BEM) is known as a robust and accurate numerical technique to handle this type of problem, because the contact among the solids occurs along their boundaries. The proposed non-linear formulation is based on the use of singular or hyper-singular integral equations by BEM, for multi-region contact. When the contact occurs between crack surfaces, the formulation adopted is the dual version of BEM, in which singular and hyper-singular integral equations are defined along the opposite sides of the contact boundaries. The structural non-linear behaviour on the contact is considered using Coulomb`s friction law. The non-linear formulation is based on the tangent operator in which one uses the derivate of the set of algebraic equations to construct the corrections for the non-linear process. This implicit formulation has shown accurate as the classical approach, however, it is faster to compute the solution. Examples of simple and multi-region contact problems are shown to illustrate the applicability of the proposed scheme. (C) 2011 Elsevier Ltd. All rights reserved.

Characterization of micro-bubble size distribution and flow configuration in DAF contact zone by a non-intrusive image analysis system and tracer tests

This paper aims to investigate the influence of some dissolved air flotation (DAF) process variables (specifically: the hydraulic detention time in the contact zone and the supplied dissolved air concentration) and the pH values, as pretreatment chemical variables, on the micro-bubble size distribution (BSD) in a DAF contact zone. This work was carried out in a pilot plant where bubbles were measured by an appropriate non-intrusive image acquisition system. The results show that the obtained diameter ranges were in agreement with values reported in the literature (10-100mm), quite independently of the investigated conditions. The linear average diameter varied from 20 to 30mm, or equivalently, the Sauter (d(3,2)) diameter varied from 40 to 50mm. In all investigated conditions, D(50) was between 75% and 95%. The BSD might present different profile (with a bimodal curve trend), however, when analyzing the volumetric frequency distribution (in some cases with the appearance of peaks in diameters ranging from 90-100mm). Regarding volumetric frequency analysis, all the investigated parameters can modify the BSD in DAF contact zone after the release point, thus potentially causing changes in DAF kinetics. This finding prompts further research in order to verify the effect of these BSD changes on solid particle removal efficiency by DAF.

Backside contact effect on the morphological and optical features of porous silicon photonic crystals

The present work reports on the effect of the type of backside contact used in the electrochemical process and their relation with the structural features and optical responses of the one-dimensional photonic crystal (PC) anodized in simple and double electrochemical cell. The PC, obtained in the single cell, showed to have thicker layers than of the PC obtained in double electrochemical cell. Additionally, the PC obtained in double cell showed highest reflectance in the band gap region than of the PCs obtained in single cell. These results suggest that the interface roughness between adjacent layers in the PC devices obtained in double electrochemical cell is minimized. (C) 2008 Elsevier Ltd. All rights reserved.

Who should wear mask against airborne infections? Altering the contact network for controlling the spread of contagious diseases

There are several ways of controlling the propagation of a contagious disease. For instance, to reduce the spreading of an airborne infection, individuals can be encouraged to remain in their homes and/or to wear face masks outside their domiciles. However, when a limited amount of masks is available, who should use them: the susceptible subjects, the infective persons or both populations? Here we employ susceptible-infective-recovered (SIR) models described in terms of ordinary differential equations and probabilistic cellular automata in order to investigate how the deletion of links in the random complex network representing the social contacts among individuals affects the dynamics of a contagious disease. The inspiration for this study comes from recent discussions about the impact of measures usually recommended by health public organizations for preventing the propagation of the swine influenza A (H1N1) virus. Our answer to this question can be valid for other eco-epidemiological systems. (C) 2010 Elsevier BM. All rights reserved.

On the basic reproduction number and the topological properties of the contact network: An epidemiological study in mainly locally connected cellular automata

We study the spreading of contagious diseases in a population of constant size using susceptible-infective-recovered (SIR) models described in terms of ordinary differential equations (ODEs) and probabilistic cellular automata (PCA). In the PCA model, each individual (represented by a cell in the lattice) is mainly locally connected to others. We investigate how the topological properties of the random network representing contacts among individuals influence the transient behavior and the permanent regime of the epidemiological system described by ODE and PCA. Our main conclusions are: (1) the basic reproduction number (commonly called R(0)) related to a disease propagation in a population cannot be uniquely determined from some features of transient behavior of the infective group; (2) R(0) cannot be associated to a unique combination of clustering coefficient and average shortest path length characterizing the contact network. We discuss how these results can embarrass the specification of control strategies for combating disease propagations. (C) 2009 Elsevier B.V. All rights reserved.

Antioxidant enzyme activity in Acidithiobacillus ferrooxidans LR maintained in contact with chalcopyrite

The total protein content and activity of the enzymes glutathione reductase (GR), superoxide dismutase (SOD) and thioredoxin reductase (TrxR) were evaluated in Acidithiobacillus ferrooxidans LR cells maintained in contact with the metal sulfide chalcopyrite for 1 and 10 days. A significant decrease in total protein content was observed in cells maintained for 10 days in the presence of chalcopyrite, suggesting proteolytic breakdown clue to exposure to the metal sulfide. Following 10 clays of contact with chalcopyrite, increases in GR, SOD and TrxR activities were detected, suggesting the formation of reactive oxygen species. After ten clays, there was a fivefold increase in GR activity, of which, isoenzyme IV represented approximately 82% of the total. An increase in Fe-SOD activity following ten days exposure to chalcopyrite was also determined, as measured on non-denaturing polyacrylamide gels. Also, after 10 days. an approximately 31-fold increase was observed for TrxR activity. The presence of oxidative stress when A. ferrooxidans is in the presence of chalcopyrite could have a negative impact on bioleaching. (C) 2010 Elsevier Ltd. All rights reserved.

Review of Contact and Dynamic Phenomena in Cold Roll Forming

This review reflects the state of the art in study of contact and dynamic phenomena occurring in cold roll forming. The importance of taking these phenomena into account is determined by significant machine time and tooling costs spent on worn out forming rolls replacement and equipment adjustment in cold roll forming. Predictive modelling of the tool wear caused by contact and dynamic phenomena can reduce the production losses in this technological process.

Diseño hidráulico de vertedores escalonados con pendientes moderadas: Metodología basada en un estudio experimental

Durante las últimas tres décadas el interés y diversidad en el uso de canales escalonados han aumentado debido al desarrollo de nuevas técnicas y materiales que permiten su construcción de manera rápida y económica (Concreto compactado con rodillo CCR, Gaviones, etc.). Actualmente, los canales escalonados se usan como vertedores y/o canales para peces en presas y diques, como disipadores de energía en canales y ríos, o como aireadores en plantas de tratamiento y torrentes contaminados. Diversos investigadores han estudiado el flujo en vertedores escalonados, enfocándose en estructuras de gran pendiente (  45o) por lo que a la fecha, el comportamiento del flujo sobre vertedores con pendientes moderadas (  15 a 30o) no ha sido totalmente comprendido. El presente artículo comprende un estudio experimental de las propiedades físicas del flujo aire-agua sobre canales escalonados con pendientes moderadas, típicas en presas de materiales sueltos. Un extenso rango de gastos en condiciones de flujo rasante se investigó en dos modelos experimentales a gran escala (Le = 3 a 6): Un canal con pendiente 3.5H:1V (  16o) y dos alturas de escalón distintas (h = 0.1 y 0.05 m) y un canal con pendiente 2.5H:1V (  22o) y una altura de escalón de h = 0.1 m. Los resultados incluyen un análisis detallado de las propiedades del flujo en vertedores escalonados con pendientes moderadas y un nuevo criterio de diseño hidráulico, el cual está basado en los resultados experimentales obtenidos. English abstract: Stepped chutes have been used as hydraulic structures since antiquity, they can be found acting as spillways and fish ladders in dams and weirs, as energy dissipators in artificial channels, gutters and rivers, and as aeration enhancers in water treatment plants and polluted streams. In recent years, new construction techniques and materials (Roller Compacted Concrete RCC, rip-rap gabions, etc.) together with the development of the abovementioned new applications have allowed cheaper construction methods, increasing the interest in stepped chute design. During the last three decades, research in stepped spillways has been very active. However, studies prior to 1993 neglected the effect of free-surface aeration. A number of studies have focused since on steep stepped chutes (  45o) but the hydraulic performance of moderate-slope stepped channels is not yet totally understood. This study details an experimental investigation of physical air-water flow properties down moderate slope stepped spillways conducted in two laboratory models: the first model was a 3.15 m long stepped chute with a 15.9o slope comprising two interchangeable step heights (h = 0.1 m and h = 0.05 m); the second model was a 3.3 m long, stepped channel with a 21.8o slope (h = 0.1 m). A broad range of discharges within transition and skimming flow regimes was investigated. Measurements were conducted using a double tip conductivity probe. The study provides new, original insights into air-water stepped chute flows not foreseen in prior studies and presents a new design criterion for chutes with moderate slopes based on the experimental results.

Concussion in contact sports: Reliable change indices of impairment and recovery

This paper reports a follow-up study to an article on the sensitivity of three tests of speed of information processing to impairment after concussion (Hinton-Bayre, Geffen, BL McFarland, 1997). Group analyses showed that practice effects can obscure the effects of concussion on information processing, thereby making the assessment of functional impairment and recovery after injury unreliable. A Reliable Change Index (RCI) was used to assess individual variations following concussion. It was found that 16 of the 20 concussed professional rugby league players were impaired 1-3 days following injury. It was also demonstrated that 7 players still displayed cognitive deficits at 1-2 weeks, before returning to preseason levels at 3-5 weeks. The RCI permits comparisons between different tests, players, and repeated assessments, thereby providing a quantitative basis for decisions regarding return to play.

A survey of contact with offspring and assistance with child care among parents with psychotic disorders

To help improve services for parents with psychotic disorders, patients with such disorders in three treatment agencies in Queensland, Australia, were surveyed about whether they were parents, how much contact they had with their offspring, and who provided assistance with child care. Of the 342 individuals with psychotic disorders mho participated in the study, 124 were parents. Forty-eight parents in the study had children under age 16, and 20 of these parents (42 percent) had their children living with them. Most parents relied on relatives or friends for assistance with child care. Barriers to child care services identified by parents were inability to pay, lack of local services, and fear of losing custody of children.