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Biomedical subjects

C Real

Publications and source records attributed to C Real.

11 recordsLinked to original sources
PubMed2005

Mapping the results of extensive surveys: the case of atmospheric biomonitoring and terrestrial mosses.

In this paper we discuss some difficulties associated with the process of constructing maps of pollution from data obtained in surveys covering extensive areas. As we show here, these problems may be wide-ranging but are seldom recognized by investigators. The origin of the problems is the existence of multiple sources of pollution in the study area, each of different intensity and affecting areas of different extent. The particular spatial structure of the pollution sources interacts with the spatial layout of the samples, resulting in data sets with distributions that are very different from the usually assumed normal distribution, and characterized by heavy tails and gross outliers. These distributions arise because of incomplete sampling of small-scale pollution processes (i.e. those occurring on a spatial scale smaller than the spatial scale of the sampling grid). After discussion of the potential problems and appropriate techniques for analyzing this kind of data, we applied the proposed techniques to a real data set of heavy metal contents in terrestrial mosses. From the exercise we concluded that a) the first step in analysis of this kind of data must be to check for the presence of spatial structure on scales larger than the sampling grid, to avoid mapping noise, and b) the map generated must not contain information about pollution sources with a spatial scale smaller than the spatial scale of the sampling grid. We present and discuss the performance of robust statistical methods of testing for spatial structure (based on robust variograms and randomization testing) and of filtering the small-scale spatial processes (using median-polishing) prior to mapping.

Atmosphere↗
PubMed2005

The effect of sampling design on extensive bryomonitoring surveys of air pollution.

In this study, we investigated if the different sampling designs normally used in extensive bryomonitoring surveys of air pollution allow compliance with the objectives proposed in the 'Heavy Metals in European Moss' project. For this, we have used data on concentrations of As, Cu, Se and Zn from five moss sampling surveys carried out in Galicia (NW Spain), using three types of sampling design: regular grid, sampling sites inside squares and the strategy recommended in the guidelines for European surveys. To study the effect of the interaction between the sampling design and the spatial pattern of the presence of contaminants, we have used a simulated and a real pattern onto which we superimposed the three sampling designs considered. We found that only random sampling and grid sampling allow compliance with the proposed objectives, and we discuss the advantages of the latter over the former. The data corresponding to studies using different sampling designs are not comparable, and in future large-scale surveys, the same design must be used if the results are to be compared and if valid conclusions are to be reached. The scale of the grid determines the scale to which the objectives are complied with, so that for correct standardization of the technique, and taking into account the most commonly used grid sizes, we recommend a grid size of 30 x 30 or 32 x 32 km. When additional samplings are required, the size of the grid size should be 30/2(n) or 32/2(n) km.

Air Pollution↗
PubMed2004

The emerging role of the emergency care practitioner.

OBJECTIVES: To examine the emerging role of the emergency care practitioner (ECP) with comparisons to paramedic practice. Key activities were identified of newly appointed ECPs using qualitative methodology and a qualitative and quantitative comparison of patient treatment was made. METHOD: A constructivist methodology taking account of stakeholder input and drawing upon the constant comparisons of different group's construction of reality. Four practitioners completed reflective patient case studies and adapted patient report forms, which were compared with a second case group of 11 paramedics. In addition individual and focus groups interviews were performed with key stakeholders. RESULTS: In the comparison between ECP and paramedic roles, 331 paramedic incidents were compared with 170 ECP reports. ECPs treated 28% of patients on scene compared with 18% by paramedics (p = 0.007). Fifty per cent of ECPs patients were conveyed compared with 64% of paramedics (p = 0.000). Analysis of the 269 reflective reports and 14 stakeholder interviews revealed four key themes. Firstly, ECPs had a beneficial impact on the deployment of resources, especially relating to non-conveyance. Secondly, their training and education improved their decision making repertoire and developed their confidence for a leadership role. Thirdly, inter-agency collaboration and cooperation was improved, and finally, care benefits were increased especially relating to immediacy of treatment and referral mechanisms. CONCLUSIONS: The results indicate that an investment in the ECP role could be beneficial, however, more work is required to evaluate the development of practice, the quality of care, and cost benefits.

Adolescent↗
PubMed2001

The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3.

How the considerable diversity of neural crest (NC)-derived cell types arises in the vertebrate embryo has long been a key question in developmental biology. The pluripotency and plasticity of differentiation of the NC cell population has been fully documented and it is well-established that environmental cues play an important role in patterning the NC derivatives throughout the body. Over the past decade, in vivo and in vitro cellular approaches have unravelled the differentiation potentialities of single NC cells and led to the discovery of NC stem cells. Although it is clear that the final fate of individual cells is in agreement with their final position within the embryo, it has to be stressed that the NC cells that reach target sites are pluripotent and further restrictions occur only late in development. It is therefore a heterogenous collection of cells that is submitted to local environmental signals in the various NC-derived structures. Several factors were thus identified which favor the development of subsets of NC-derived cells in vitro. Moreover, the strategy of gene targeting in mouse has led at identifying new molecules able to control one or several aspects of NC cell differentiation in vivo. Endothelin peptides (and endothelin receptors) are among those. The conjunction of recent data obtained in mouse and avian embryos and reviewed here contributes to a better understanding of the action of the endothelin signaling pathway in the emergence and stability of NC-derived cell phenotypes.

Animals↗
PubMed1999

[Interstitial cystitis: medical treatment].

Interstitial cystitis is a chronic disease of the bladder and its etiology is still unknown. In this article we treat the different approaches to this disease, supported by the fact that a clear therapeutic protocol doesn't exist.

Algorithms↗
PubMed1995

A method for testing denture adhesives.

An in vitro test is described that simulates the in vivo fate of a denture adhesive, namely destruction, dilution, and dissolution of the adhesive, by repeated measurement of tensile bond strength for the adhesive in isotonic saline over time. The bond strengths were measured under two different settings of the testing machine. The main compositions of three denture adhesive pastes, Fittydent, Fixodent, and Super Poli-Grip and one powder adhesive, Super Wernet's, were determined by infrared spectroscopy. The tensile bond strengths of these adhesives and those of pure tragacanth gum were subjected to a three-way analysis of variance. The Fittydent and Super Poli-Grip adhesives exhibited the best results over time. The most appropriate of the described methods for testing denture adhesives seem useful; however, when seen in relation to the results of a published clinical study where the patients were asked to evaluate the retention and the duration of some of these adhesives, there are indications that the clinical validity of the method might be improved if paste adhesives are tested at temperatures above 35 degrees C.

Adhesives↗
PubMed1994

[Malignant tumors of the small intestine. Clinical and therapeutic considerations on 23 observed cases].

Small bowel tumours observed by the Authors at the IInd Surgical pathology of Pavia University between 1974 and 1992 were reviewed. There were found 23 cases; istopathologic findings, clinical presentation, diagnostic aspects and therapeutic options are discussed. The primary role of surgery in the treatment of these cancers is emphasized, but this can be curative only if diagnosis has been timely.

Adenocarcinoma↗
PubMed1983

Acyl pattern of adipose tissue triglycerides, plasma free fatty acids, and diet of a group of men participating in a primary coronary prevention program (the Oslo Study).

The acyl pattern of adipose tissue triglycerides and of plasma free fatty acids were determined after 7 yr of diet intervention on elevated plasma cholesterol in 42 men taking part in the smoking-lipid trial of the Oslo Study. Twenty-two of the men were advised to change dietary habits (mainly reduce saturated fat) whereas the remaining 20 were controls. The adipose tissue from men in the intervention group contained relatively more linoleic and linolenic acids and relatively less saturated and monounsaturated fatty acids compared to men in the control group. There were strong correlations between the relative content of several fatty acids in adipose tissue triglycerides and plasma free fatty acid. Furthermore, there was a close correlation between the intake of polyunsaturated fatty acids found in a dietary survey done 2 to 3 yr before this study and the relative content of polyunsaturated fatty acids in adipose tissue.

Adipose Tissue↗