210Po and 238U isotope concentrations in commercial bottled mineral water samples in Spain and their dose contribution

(210)Po is a naturally occurring radionuclide, belonging to the uranium series, which is present in minute amounts in the different environmental compartments (water, soil, biota). Through its route along the trophic chain, it can be incorporated in the human body via ingestion of waters and/or food. This radionuclide is highly radiotoxic, being one of the main contributors to the committed effective dose via ingestion by the general population. In this work, the contribution of this radionuclide to the committed effective dose received by the Spanish population via consumption of bottled mineral waters is evaluated. With this end, the (210)Po activity concentrations in a total of 32 different commercial bottled mineral waters have been determined by alpha-particle spectrometry. The determined contribution is also compared with the contributions of other natural radionuclides such as (234)U and (238)U.

Forensic paleoradiology: identification of a public figure murdered in 1837

Two unidentified graves were found during construction of a new crypt at the Metropolitan Cathedral in Santiago, Chile. One of the bodies was sent to the Teaching Hospital of the University of Chile for forensic identification. The fully mummified corpse was suspected to be that of Diego Portales, a prominent Chilean politician who was assassinated in 1837. The condition of the corpse determined that the best way to establish a positive identification was by means of a multislice CT scan, since the body had been autopsied and embalmed using unknown substances. This paper presents the results of the virtual autopsy of the remains and compares these results with the original autopsy report of 1837. The embalming method is also discussed, based on chemical analysis using inductively coupled mass spectroscopy (ICP-MS) and cold vapour atomic absorption spectrometry (HG-CVAAS).

High sensitivity cardiac troponin T and interleukin-6 predict adverse cardiovascular events and mortality in anticoagulated patients with atrial fibrillation

There are limited data on the prognostic role of biomarkers in anticoagulated patients with atrial fibrillation (AF). We evaluated the prognostic value of high sensitivity TnT (hsTnT) and high-sensitivity interleukin-6 (hsIL6) in a large cohort of AF patients taking oral anticoagulant therapy (OAC) as both biomarkers have been associated with adverse cardiovascular events.

METHODS

We studied 930 patients (51% male; median age 76) with permanent/ paroxysmal AF who were stabilized (for at least 6 months) on OAC (INRs 2.0-3.0). Plasma hsTnT and hsIL6 levels were quantified by electrochemiluminescense immunoassay at baseline. Patients were followed-up for up to 2 years, and adverse events (thrombotic and vascular events, mortality and major bleeding) were recorded.

RESULTS

At follow-up, 96 patients (3.97%/year) died whilst 107 had an adverse cardiovascular event (3.14%/year). On multivariate analysis, high hsTnT and high hsIL6 remained significantly associated with prognosis even after adjusting for CHADS2 score: HR 2.21 (1.46-3.35, P<0.001) for high hsTnT and 1.97 (1.29-3.02, P=0.002) for high hsIL6, for adverse cardiovascular events. For all-cause mortality, the HRs were 1.79 (1.13-2.83, P=0.013) and 2.48 (1.60-3.85, P<0.001), respectively. The integrated discrimination index (IDI) values of clinical scores (CHADS2 and CHA2 DS2-VASc) were improved by the addition of hsTnT and/or hsIL6 (all P<0.05).

CONCLUSION

In a large 'real world' cohort of anticoagulated AF patients, both hsTnT and hsIL6 levels provided prognostic information that was complementary to clinical risk scores for prediction of long-term cardiovascular events and death, suggesting that these biomarkers may potentially be used to refine clinical risk stratification in AF.

Consistency of the auditory evoked response: the presence of aberrant responses and their effect on N100 localization

The structure and distribution of the sources underlying the generation of evoked potentials (EPs) is often very complex. In an effort to improve localization accuracy of the auditory N100 (negative response occurring around 100ms poststimulus) component, we analyzed 13 datasets of single-trial EPs obtained from normal subjects using an iterative independent component analysis procedure which allowed us to detect a clear N100 component in each single trial and to study gross changes in component morphology across trials. We found that single-trial N100 amplitude was most often negative in polarity, as expected, but occasionally exhibited a marked reversal to become positive. The average N100, however, showed the typical negative polarity, in all subjects. Based on this observation, we separated the processed single trials in two groups of typical and aberrant responses, and from each group, we computed a partial EP that was used to localize the underlying intracranial sources. Additionally, we localized the classical ensemble average EP. Before processing, the N100 sources were identified correctly in the primary auditory cortex in only four datasets, while after processing, all 13 datasets yielded correct localizations, and the confidence volume of the sources improved by about 80%. Further analysis demonstrated that in nine datasets the improvement was mostly due to the typical responses, while the aberrant responses had an antagonistic effect. Our results suggest that aberrant responses should not be included in source localizations, especially when EEG-based brain mapping is intended as a clinical tool.

Influence of local factors in the relationship between mortality and heat waves: Castile-La Mancha (1975-2003)

INTRODUCTION

All the climate-change studies undertaken to date agree that one of the principal consequences of this phenomenon is the increase in heat waves, which, without exception, are linked to marked rises in mortality. The characteristics that modulate and determine the relationship between high temperatures and health must therefore be ascertained in the greatest possible detail, so that really effective prevention plans can be designed to address temperature extremes.

METHODS

We examined the effect of heat waves on daily non-accidental-cause mortality across all age groups in the Castile-La Mancha region (Spain) from 1975 to 2003. Quantitative analyses were performed using autoregressive integrated moving average (ARIMA) models, with other covariates, such as pressure trends, relative humidity, and duration and chronological number of heat waves.

RESULTS

Mortality increased significantly with respect to the mean, when temperatures exceeded the designated provincial thresholds in Castile-La Mancha. For each degree centigrade that temperatures exceeded these thresholds, the percentage increase in mortality amounted to increases of approximately 12% over the daily mean, albeit with clear provincial variations. The longest heat waves were associated with daily mortality, with those at the end of summer causing the lowest mortality. Meteorological situations most closely associated with increases in mortality were cyclonic conditions accompanied by low humidity.

CONCLUSIONS

Spatio-temporal variability in the temperature-mortality relationship must be studied in order to enable really effective heat-wave prevention plans to be drawn up. The influence of variables, such as heat-wave duration or time of appearance, is important in the total increase in mortality during temperature extremes. Since parameters, such as humidity or pressure trends, can play very different roles in different geographical settings, they should be analysed separately from temperature.

[Children hospitalized with influenza pneumonia AH1N1/2009 pandemic in the INSN]

OBJECTIVE

To determine the clinical and demographic characteristics of pneumonia with influenza virus AH1N1/2009 pandemic at the National Institute of Child.

METHODS

Retrospective case series in children hospitalized for influenza pneumonia pandemic AH1N1/2009 in a pediatric hospital. Reviewed the medical records between the months of June to September 2009. All cases had virological confirmation, we describe the clinical characteristics and conditions of severity.

RESULTS

A total of 74 children of pneumonia with influenza virus AH1N1/2009 pandemic (NVIp), of those 50 were community acquire pneumonia viral (NACv) and 24 pneumonia nosocomial viral (NNv), 16 required mechanical ventilation. 12 died, all had preexisting factors. NN cases showed statistical association with mortality. The most frequent factors were malnutrition, respiratory infections, congenital heart disease and neurological deficits In NACv cases the children under 6 years accounted for 72% (36/50). The median disease duration was 5 days. The most frequent symptoms were fever, cough, runny nose. Received oseltamivir 82%. The chest radiograph 48% of cases showed patchy infiltrates and 44% interstitial infiltrate on chest radiograph. Protein c reactive (CRP) more than 10mg / L was significantly associated with respiratory failure (p <0.05).

CONCLUSIONS

Cases of NN found who had more mortality, even those who had the highest PCR and those with preexisting condition.

[Regional pilot study to evaluate the laboratory turnaround time according to the client source]

PURPOSE

To show turnaround time to client source in eight laboratories covering eight Health Areas (2,014,475 inhabitants) of the Valencian Community (Spain).

MATERIAL AND METHODS

Internal Laboratory Information System (LIS) registers (test register and verification date and time), and daily LIS registers were used to design the indicators, These indicators showed the percentage of key tests requested (full blood count and serum glucose and thyrotropin) that were validated on the same day the blood was taken (inpatients and Primary Care and/or at 12 a.m. (inpatients). Urgent (stat) tests were also registered as key tests (serum troponin and potassium) and were recorded in minutes. Registers were collected and indicators calculated automatically through a Data Warehouse application and OLAP cube software.

RESULTS

Long turnaround time differences were observed at 12 a.m. in inpatients, and in the day of sample extraction in primary care patients. The variability in turnaround of stat tests is related to hospital size, activity and validation by the laboratory physician.

CONCLUSIONS

The study results show the large turnaround time disparity in eight Health Care Areas of Valencian Community. The various requesting sources covered by the laboratories create the need for continuous mapping processes redesign and benchmarking studies to achieve customer satisfaction.

Molecular evolution, mutation size and gene pleiotropy: a geometric reexamination

The influence of phenotypic effects of genetic mutations on molecular evolution is not well understood. Neutral and nearly neutral theories of molecular evolution predict a negative relationship between the evolutionary rate of proteins and their functional importance; nevertheless empirical studies seeking relationships between evolutionary rate and the phenotypic role of proteins have not produced conclusive results. In particular, previous studies have not found the expected negative correlation between evolutionary rate and gene pleiotropy. Here, we studied the effect of gene pleiotropy and the phenotypic size of mutations on the evolutionary rate of genes in a geometrical model, in which gene pleiotropy was characterized by n molecular phenotypes that affect organismal fitness. For a nearly neutral process, we found a negative relationship between evolutionary rate and mutation size but pleiotropy did not affect the evolutionary rate. Further, for a selection model, where most of the substitutions were fixed by natural selection in a randomly fluctuating environment, we also found a negative relationship between evolutionary rate and mutation size, but interestingly, gene pleiotropy increased the evolutionary rate as √n. These findings may explain part of the disagreement between empirical data and traditional expectations.

Role of Saharan dust in the relationship between particulate matter and short-term daily mortality among the elderly in Madrid (Spain)

BACKGROUND

Saharan dust outbreaks are a common phenomenon in the Madrid atmosphere. The current Directive 2008/50 CE governing air quality in European cities, draws no distinction between which particulate matter (PM(10), PM(2.5) or PM(10-2.5)) would be the best indicator on days with/without Saharan dust intrusions. This study sought to identify the role played by Saharan dust in the relationship between particulate matter (PM(10), PM(2.5) and PM(10-2.5)) concentrations and daily mortality among the elderly in the city of Madrid.

METHODS

We conducted an ecological longitudinal time-series study on daily mortality among the over-75 age group, from 2003 to 2005. Poisson regression models were constructed for days with and without Saharan dust intrusions. The following causes of daily mortality were analysed: total organic causes except accidents (International Classification of Diseases-10th revision (ICD-10): A00-R99); circulatory causes (ICD-10: I00-I99); and respiratory causes (ICD-10: J00-J99). Daily mean PM(10), PM(2.5) and PM(10-2.5) levels were used as independent variables. Control variables were: other ambient pollutants (chemical, biotic and acoustic); trend; seasonalities; influenza epidemics; and autocorrelations between mortality series.

RESULTS

While daily mean PM(2.5) concentrations in Madrid displayed a significant statistical association with daily mortality for all the above causes on days without Saharan dust intrusions, this association was not in evidence for PM(10) or PM(10-2.5) in the multivariate models. The relative risks (RRs) obtained for an increase of 10 μg/m(3) in PM(2.5) concentrations were: 1.023 (1.010-1.036) for total organic causes; 1.033 (1.031-1.035) for circulatory causes; and 1.032 (1.004-1.059) for respiratory causes. On Saharan dust days, a significant statistical association was detected between PM(10) (though not PM(2.5) or PM(10-2.5)) and mortality for all 3 causes analysed, with RRs statistically similar to those reported for PM(2.5).

CONCLUSIONS

The best air quality indicators for evaluating the short-term health effects of particulate matter in Madrid are therefore PM(10) concentrations on days with, and PM(2.5) concentrations on days without Saharan dust outbreaks. This fact should be taken into account in a European Directive regulating ambient air quality in almost all countries in the Mediterranean area.

Short-term effect of fine particulate matter (PM 2.5) on daily mortality due to diseases of the circulatory system in Madrid (Spain)

INTRODUCTION

Owing to their small size, fine particles, i.e., those having a diameter ≤ 2.5 μm (PM(2.5)), have a high alveolar penetration capacity, thereby triggering a local inflammatory process with circulatory repercussion. Despite being linked to respiratory and cardiovascular morbidities, there is limited evidence of an association between this type of particulate matter and short-term increases in mortality.

OBJECTIVE

The aim of this study was to analyse and quantify the short-term impact of PM(2.5) on daily mortality due to diseases of the circulatory system, registered in Madrid from 1 January 2003 to 31 December 2005.

METHODS

An ecological longitudinal time-series study was conducted, with risks being quantified by means of Poisson regression models. As a dependent variable, we took daily mortality registered in Madrid from 1 January 2003 to 31 December 2005, attributed to all diseases of the circulatory system as classified under heads I00-I99 of the International Classification of Diseases-10th revision (ICD-10) and broken down as follows: I21, acute myocardial infarction (AMI); I20, I22-I25, other ischemic heart diseases; and I60-I69, cerebrovascular diseases. The independent variable was daily mean PM(2.5) concentration. The other variables controlled for were: chemical pollution (PM(10), O(3), SO(2), NO(2) and NO(x)); acoustic and biotic pollution; influenza; minimum and maximum temperatures; seasonalities; trend; and autocorrelation of the series.

RESULTS

A linear relationship was observed between PM(2.5) levels and mortality due to diseases of the circulatory system. For every increase of 10 μg/m(3) in daily mean PM(2.5) concentration, the relative risks (RR) were as follows: for overall circulatory mortality, associations were established at lags 2 and 6, with RR of 1.022 (1.005-1.039) and 1.025 (1.007-1.043) respectively; and for AMI mortality, there was an association at lag 6, with an RR of 1.066 (1.032-1.100). The corresponding attributable risks percent (AR%) were 2.16%, 2.47% and 6.21% respectively. No statistically significant association was found with other ischemic heart diseases or with cerebrovascular diseases.

CONCLUSION

PM(2.5) concentrations are an important risk factor for daily circulatory-cause mortality in Madrid. From a public health point of view, the planning and implementation of specific measures targeted at reducing these levels constitute a pressing need.

Mortality from cold waves in Castile--La Mancha, Spain

INTRODUCTION

As is known, the effects of extreme temperatures on mortality are characterised by an annual periodicity, with a rise centred in the winter months. The most recent epidemiological studies show that mortality caused by cold waves is, in many cases, comparable to that caused by the severest heat waves. This study sought to quantify the rise in mortality due to extreme cold and the factors that determine the relationship between these variables in Castile-La Mancha (Spain).

METHODS

We examined the effect of extreme winter temperature on daily non accidental cause mortality in Castile - La Mancha from 1975 to 2003, for all ages. Quantitative analyses were performed using ARIMA models, with other covariates, such as influenza, pressure trends, relative humidity, and cold wave duration and chronological number.

RESULTS

There were two mortality peaks: a short-term peak (with a lag of 3 to 7 days); and a longer term peak (of under two weeks). Excess mortality during cold waves was around 10% per degree centigrade below the threshold temperature for all the provinces except Guadalajara, where an increase of only 4.61% was detected. Mortality increased in response to rises in cold-wave duration and relative humidity. Cold waves occurring at the end of the "winter" season caused the greatest mortality.

CONCLUSIONS

This study confirms that daily mortality in Castile - La Mancha increases during cold waves. Efficient cold-wave prevention plans must therefore be implemented. Such plans should be based on in-depth knowledge of the causes that underlie and modulate the relationship between low temperatures and health effects.

Comparison between two methods of defining heat waves: a retrospective study in Castile-La Mancha (Spain)

INTRODUCTION

Following the 2003 heat wave, many European countries implemented heat-wave prevention plans. A number of aspects can prove fundamental in determining the effectiveness of such plans, and of these we sought to analyse the criteria used to define threshold temperatures and trigger a higher level of intervention.

METHOD

Retrospective study of the days on which heat-wave thresholds were exceeded during the period 1974-2003 was conducted. We compared when and at what level the heat-wave prevention plan would have been activated using a statistical-meteorological criterion (as applied by the Spanish Ministry of Health & Consumer Affairs) versus a temperature-mortality criterion.

RESULTS

The number of days on which the threshold was exceeded was far higher when the temperature-mortality criterion was applied. The temperature percentile at which a heat wave occurred was different for each province analysed and was inversely proportional to its respective ageing index. Using both criteria, there was an increase in heat-wave days per decade.

CONCLUSION

The establishment of a heat-wave threshold temperature must be based on knowledge of the cause-effect relationship between temperature and the health of a given population. Mortality is an appropriate indicator of population health. The future effects of climate change render it essential for this relationship to be studied on a local scale, so as to enable truly efficient prevention plans to be drawn up.

A versatile optoelectronic aid for low vision patients

The purpose of this work is to describe a versatile optoelectronic aid for low vision rehabilitation based on reconfigurable hardware. This aid is easily adaptable to diverse pathologies (with different associated processing tasks) and to the progression of the visual impairment. This platform has a mobile configuration that uses a see-through head-mounted display (Nomad). We have implemented different types of vision enhancement on this versatile platform, and briefly summarize here their computational costs (in terms of hardware resource requirements). We have evaluated two representative capabilities of this aid (Augmented View and digital zoom) with measurements of visual acuity, contrast sensitivity and visual field. We have tested the Nomad head-mounted display and the Augmented View modality, in eight subjects with retinitis pigmentosa: the digital zoom was tested in six low vision subjects and nine normally-sighted subjects. We show that the Nomad display with Augmented View configuration does not impair the residual vision; and that there is an increase in visual acuity (VA) with the digital zoom configuration. The major advantage of this platform is that it can easily embed different image processing tasks and since it is based on a FPGA device, it can be specifically configured to tasks requiring real-time processing.

Short-term effect of concentrations of fine particulate matter on hospital admissions due to cardiovascular and respiratory causes among the over-75 age group in Madrid, Spain

OBJECTIVES

This study sought to analyse the effect of daily mean concentrations of fine particulate matter (diameter <2.5 microm; PM(2.5)) on hospital admissions due to circulatory and respiratory causes among an elderly population (>75 years) in Madrid between 2003 and 2005.

STUDY DESIGN

Ecological longitudinal time-series study.

METHODS

The dependent variable used was the daily number of emergency hospital admissions registered at the Gregorio Marañón University Teaching Hospital. The following causes were analysed: all causes [International Classification of Diseases 9th Version (ICD-9:1-799)], respiratory causes (ICD-9: 460-519) and circulatory causes (ICD-9: 390-459). Analysis focused on subjects over 75 years of age. Daily records of mean concentrations of PM(2.5), PM(10), NO(2), NO(x), SO(2) and O(3) in Madrid were used as independent variables. The control variables were seasonalities, trend, influenza epidemics, noise and pollen concentrations. Poisson regression models were constructed to calculate the relative risk (RR) and attributable risk (AR). Analyses were performed for the entire year and for the winter and summer.

RESULTS

PM(2.5) was the single primary pollutant that proved statistically significant in all models. The functional relationship with hospital admissions was linear and had no threshold. Taking the year as a whole, the RRs among people over 75 years of age for an increase of 10 microg/m(3) in PM(2.5) concentrations were: 1.038 [95% confidence interval (CI) 1.022-1.053] for all causes at lag 0; 1.062 (95% CI 1.036-1.089) for circulatory causes at lag 0; and 1.049 (95% CI 1.019-1.078) for respiratory causes at lag 3. The ARs were 3.6%, 5.9% and 4.6%, respectively. These risks increased in winter and no statistically significant associations were observed in summer. PM(2.5) was the only primary pollutant that showed a statistically significant association with hospital admissions among people over 75 years of age in Madrid across the study period.

CONCLUSION

Measures should be implemented to reduce PM(2.5) concentrations in Madrid.

Short-term impact of particulate matter (PM2.5) on daily mortality among the over-75 age group in Madrid (Spain)

BACKGROUND

The 2006 World Health Organization Air Quality Guidelines recommend using particulate matter having a diameter of under 2.5 micra (PM(2.5)) rather than PM(10) as an indicator of air particle concentration, a pattern followed by new European directives. Nevertheless, few studies have analysed this new indicator's impact at a European level on daily mortality among a high-risk group, such as persons aged over 75 years.

OBJECTIVE

This study sought to analyse and quantify the effect of PM(2.5) on daily cause-specific mortality among the over-75 age group in the city of Madrid.

METHODS

Using Poisson regression with Generalized Additive Models (GAM), a longitudinal, ecological time-series study examined the following causes of death: all causes except accidents (International Classification of Diseases-9th revision (ICD 9): 1-799); circulatory causes (ICD 9: 390-459); and respiratory causes (ICD 9: 460-519). These were adjusted for other chemical, biotic and acoustic pollutants. Further control variables considered were: trend; seasonality; influenza epidemics; and autocorrelation between mortality series.

RESULTS

A significant statistical association was detected between daily mean PM(2.5) particle concentrations and all-cause mortality in the city of Madrid. This association was not in evidence for PM(10) concentrations. The Relative Risks found for an increase of 25 microg/m(3) in PM(2.5) concentrations were as follows: all-cause mortality, 1.057 (1.025-1.088); circulatory-cause mortality, 1.088 (1.041-1.135); and respiratory-cause mortality, 1.122 (1.056-1.189). The Attributable Risks were 5.41%, 8.12% and 10.90% respectively. This effect was observed in the short term (lags 1-2).

CONCLUSION

Our results indicate a strong impact of PM(2.5) concentrations on daily mortality among the over-75 age group in Madrid, and underscore the need for measures aimed at lowering the concentration levels of this primary air pollutant in large cities, particularly by reducing motor vehicle traffic, the main source of such pollutant emission in urban atmospheres.

Deep subthreshold Xi;{-} production in Ar + KCl reactions at 1.76A GeV

We report first results on a deep subthreshold production of the doubly strange hyperon Xi;{-} in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar + KCl was studied with the High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample was collected, allowing for the investigation of the decay channel Xi;{-} --> Lambdapi;{-}. The deduced Xi;{-}/(Lambda + Sigma;{0}) production ratio of (5.6 +/- 1.2_{-1.7};{+1.8}) x 10;{-3} is significantly larger than available model predictions.

Visual system based on artificial retina for motion detection

We present a bioinspired model for detecting spatiotemporal features based on artificial retina response models. Event-driven processing is implemented using four kinds of cells encoding image contrast and temporal information. We have evaluated how the accuracy of motion processing depends on local contrast by using a multiscale and rank-order coding scheme to select the most important cues from retinal inputs. We have also developed some alternatives by integrating temporal feature results and obtained a new improved bioinspired matching algorithm with high stability, low error and low cost. Finally, we define a dynamic and versatile multimodal attention operator with which the system is driven to focus on different target features such as motion, colors, and textures.

Imposex and gender-independent butyltin accumulation in the gastropod Nassarius reticulatus from the Cantabrian coast (N Atlantic Spain)

The gastropod Nassarius reticulatus has been used as a tributyltin (TBT) biomonitor over the last two decades, and it is now endorsed by Atlantic Europe environmental agencies. However, there is one important question debated by the earliest studies still unresolved, namely whether butyltin accumulation in tissues is sex-dependent or not. Thus, a field survey was conducted along the Cantabrian coast: samples were subject to both customary imposex and modern chemical analyses. No significant bioaccumulation differences between sexes were found for any of the three butyltin species examined (i.e. TBT plus derivatives di- and mono-butyltin). In addition, both lower-than-expected absolute butyltins and minor relative TBT proportions in tissues conform with decreasing pollution in nearby areas. Imposex, though, is generally still considerable due to a lesser responsiveness of population indexes. Finally, one sample showed no sign of imposex but quantifiable butyltins; these are good news indicating that TBT is getting back down to levels around the induction threshold of this specific biological effect.

On-line analysis of biosignals for the automation of total and specific sleep deprivation in the rat

A computer-based system that automates sleep studies, including sleep deprivation paradigms, is described. The system allows for total or REM-specific sleep deprivation and is based on a reliable, fast-responding, on-line state detection algorithm linked to a dependable intervention device. Behavioral state detection is achieved by dimension reduction of short-term EEG power spectrum. Interventions are made by serial outputs to servomotors that move a cage with different patterns and variable intensity. The system can adapt itself to individual characteristics and to changes in recording conditions. Customized protocols can be designed by defining the states or stages to be deprived, including scheduling temporal patterns. A detailed analysis of the relevant signals during and after deprivation is readily available. Data is presented from two experimental designs in rats. One consisted of specific REM-sleep short-term deprivation and the other of 10-hour total sleep deprivation. An outline of conceptual and practical considerations involved in the automation of laboratory set-ups oriented to biosignal analysis is provided. Careful monitoring of sleep EEG variables during sleep deprivation suggests peculiarities of brain functioning in that condition. A corollary is that sleep deprivation should not be considered to be merely a forced prolonged wakefulness.

Enhancement of antiferromagnetic coupling in magnetic multilayers by low energy ion beam substrate nanopatterning

Ion beam irradiation has been shown to be an interesting tool for tailoring the magnetic properties of thin films and multilayers. The modified properties include magnetic anisotropy, interlayer exchange coupling, exchange bias, magnetic domain structure and magnetization reversal. In this work, new results are shown concerning the enhancement, by one order of magnitude, of the antiferromagnetic coupling strength in amorphous CoSi/Si multilayers by irradiating Si(100) substrates with 1 keV Ar(+) ions. The ion beam exposure induces an increase of the substrate roughness, from 0.07 to 0.88 nm, which enhances antiferromagnetic coupling in the magnetic multilayers grown on top. One possible mechanism governing this enhancement is discussed, related to the formation of magnetic/non-magnetic regions where dipolar interactions could stabilize the antiferromagnetic alignment. The presence of non-magnetic regions is suggested by the observed trend to superparamagnetism, and is expected since the Curie temperature of the amorphous CoSi alloy used is slightly above but very close to room temperature. Accordingly, small fluctuations in the local composition, leading to an enrichment of Si, would produce non-magnetic regions enabling dipolar interactions to take place. Furthermore, the ion beam induced increase of roughness makes surface diffusion of the atoms arriving at the sample difficult, favoring the formation of local non-magnetic inhomogeneities. Finally, the role of other possible mechanisms to enhance antiferromagnetic coupling is also briefly discussed.

Resistance in pepper plants induced by Fusarium oxysporum f. sp. lycopersici involves different defence-related genes

Inoculation with Fusarium oxysporum f. sp. lycopersici (FOL) protects pepper plants from subsequent infection with Phytophthora capsici. In the present paper, the level of local and systemic protection achieved by plants induced with FOL was evaluated by quantifying the pathogen biomass and using real-time PCR. Differences in the amount of pathogen were found in stems and roots between FOL-treated and untreated plants, while pathogen biomass could not be detected in leaves of induced plants. Five defence-related genes coding for a PR-1 protein, a beta-1,3-glucanase, a chitinase, a peroxidase and a sesquiterpene cyclase were up-regulated 48 h after treatment in all the tissues studied, and maximal mRNAs levels were found in leaves.

HIV-related stigma, service utilization, and status disclosure among truck drivers crossing the Southern borders in Brazil

HIV-related stigma and discrimination (S&D) have been shown to impede prevention, care and treatment. Yet, few quantitative studies have tested the associations between stigma, service utilization and status disclosure, especially in countries with concentrated HIV epidemics. Surveys, administered to a random sample of 1,775 truck drivers crossing Southern borders in Brazil, included items on multiple conceptual domains of S&D, such as fear of casual contact and blame towards people living with HIV/AIDS. Pearson's chi-square tests and logistic regression were used to examine correlations. Less stigma (both individual items and grouped as a scale) was significantly correlated with VCT use (p<or=0.001), knowing where to get tested (p<or=0.001) and willingness to disclose HIV-positive test results (p=0.013). Findings indicate that stigma is an important barrier to HIV testing and disclosure among truck drivers in Southern Brazil. Learning more about stigma is important given the growing assertions that testing is a 'critical gateway' to HIV prevention and treatment. As access to HIV testing and treatment improves, providers increasingly need to understand and address how stigma acts as a barrier to services.

Parasite contamination of soil in households of a Mexican rural community endemic for neurocysticercosis

High neurocysticercosis (NC) prevalence was recently determined by a computed tomography (CT) scan study in the community of Tepetzitzintla, State of Puebla, Mexico. The aim of the present work was to evaluate the magnitude of fecal and parasite contamination by Taenia spp. in the soil of households of this community during the four seasons of the year. The toilet, backyard, kitchen, washboard, water containers and corrals of 14 to 26 households were sampled during each season. High Taenia spp. egg intensity was found in 24.2% of the sampled areas. The highest percentage was detected in Spring and the lowest in Summer. Significantly higher levels of Taenia spp. eggs were present in kitchen soil samples. A significant correlation was found between the presence of Taenia spp. eggs in household soil during the Summer, and NC diagnoses of the inhabitants by CT scan. Coproparasitological examinations and anti-cysticercal antibodies were determined in a cohort of inhabitants of the sampled households. Antibody levels and coproparasitological results were not associated with NC. Overall, these results illustrate the high degree of fecal contamination of potential risk to human health in rural communities and could be of use for control programmes.

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells

alpha(1H) T-type channels recruited by beta(1)-adrenergic stimulation in rat chromaffin cells (RCCs) are coupled to fast exocytosis with the same Ca(2+) dependence of high-threshold Ca(2+) channels. Here we show that RCCs exposed to chronic hypoxia (CH) for 12-18 h in 3% O(2) express comparable densities of functional T-type channels that depolarize the resting cells and contribute to low-voltage exocytosis. Following chronic hypoxia, most RCCs exhibited T-type Ca(2+) channels already available at -50 mV with the same gating, pharmacological and molecular features as the alpha(1H) isoform. Chronic hypoxia had no effects on cell size and high-threshold Ca(2+) current density and was mimicked by overnight incubation with the iron-chelating agent desferrioxamine (DFX), suggesting the involvement of hypoxia-inducible factors (HIFs). T-type channel recruitment occurred independently of PKA activation and the presence of extracellular Ca(2+). Hypoxia-recruited T-type channels were partially open at rest (T-type 'window-current') and contributed to raising the resting potential to more positive values. Their block by 50 microm Ni(2+) caused a 5-8 mV hyperpolarization. The secretory response associated with T-type channels could be detected following mild cell depolarizations, either by capacitance increases induced by step depolarizations or by amperometric current spikes induced by increased [KCl]. In the latter case, exocytotic bursts could be evoked even with 2-4 mm KCl and spike frequency was drastically reduced by 50 microm Ni(2+). Chronic hypoxia did not alter the shape of spikes, suggesting that hypoxia-recruited T-type channels increase the number of secreted vesicles at low voltages, without altering the mechanism of catecholamine release and the quantal content of released molecules.

Amplitude modulation patterns of local field potentials reveal asynchronous neuronal populations

Neural oscillations, which appear in several areas of the nervous system and cover a wide frequency range, are a prominent issue in current neuroscience. Extracellularly recorded oscillations are generally thought to be a manifestation of a neural population with synchronized electrical activity resulting from coupling mechanisms. The vertebrate olfactory neuroepithelium exhibits beta-band oscillations, termed peripheral waves (PWs), in their population response to odor stimulation. Here, we examine PWs in the channel catfish and propose that their properties could be explained as the superposition of asynchronous oscillators. Our model shows that the intriguing random pattern of amplitude-modulated PWs could be explained by Rayleigh fading, an interference phenomenon well known in physics and recognizable using statistical methods and signal analysis. We are proposing a mathematical fingerprint to characterize neural signals generated by the addition of random phase oscillators. Our interpretation of PWs as arising from asynchronous oscillators could be generalized to other neuronal populations, because it suggests that neural oscillations, detected in local field potential recordings within a narrow frequency band, do not necessarily originate from synchronization events.

[Choroidal detachment associated with delayed spontaneous ocular hypotony]

CASE REPORTS

We report two cases of delayed spontaneous hypotony associated with choroidal detachment and hypotony maculopathy. Both patients had undergone uneventful cataract extractions 10 and 6 years prior to the occurrence of apparently spontaneous hypotony. Trabeculectomy was combined with phacoemulsification in one of them. Both had been receiving timolol at the time of presentation.

DISCUSSION

Delayed spontaneous hypotony, without recent ocular surgery or trauma, represented a challenge in both the diagnosis and management processes in these patients. We have analysed the main causes.

[Prevalence of vascular risk factors among Spanish populations aged 70 years and over, as reported in door-to-door studies on neurological diseases]

INTRODUCTION

The aim of this study was to re-analyze door-to-door studies on neurological diseases among the elderly, in which vascular risk factors (VRF) were studied, describing methodological characteristics and prevalence of VRF.

METHODS

The surveys were identified in two phases. They were aimed at ascertaining prevalence of stroke, dementias or Parkinsonisms and, at the time of individual screening, had collected data on at least three of the following VRF: arterial hypertension (AHT), smoking habit, diabetes mellitus and hypercholesterolemia. A questionnaire was drawn up to collect the data reported in each study, and a database was constructed. VRF prevalences were quantified and analyzed using logistic regression.

RESULTS

The total of the re-analyzed population was 12,510 persons aged 70 years and over, residents in seven geographic areas during the period 1994-2002. Information available on VRF was essentially self-reported. The prevalence of self-reported AHT was 25.7 % in men and 44.2 % in women, and that of measured AHT was 61 % and 71.9 %, respectively. Populations with arterial pressure obtained by direct measurement registered 138 higher risks (OR: 1.74; 95 % CI: 1.51-2.01, and OR: 1.48; 95% CI: 1.33-1.64). Reported prevalence of diabetes, hypercholesterolemia and smoking habit were 14.3 %, 23.3% and 8.5 %, respectively.

CONCLUSIONS

There was a high prevalence of VRF among the Spanish elderly population. However, its relationship with dementia, Parkinsonisms and cerebrovascular disease could not be studied due to the poor quality of the VRF data. The differences between measured and self-reported arterial pressure suggest the existence of undetected AHT and wide scope for prevention.

Distribution of butyltin and derivatives in oyster shells and trapped sediments of two estuaries in Cantabria (Northern Spain)

Distribution of butyltin compounds (BTs) and derivatives (monobutyltin, MBT; dibutyltin, DBT and tributyltin, TBT) was analysed in Crassostrea gigas oyster shells and the sediments trapped in the shell chambers, from two different estuaries in Cantabria (Northern Spain), with very different environmental conditions, where previous data have not been reported. Inorganic tin analysis in oyster shells was performed in order to study the degradation of BTs. Shell thickening and losses in biological growth are related with the presence of TBT, and were determined using three morphological indexes. Total BTs concentrations, expressed as Sn, ranged from 18.0 ng g(-1) to 176.7 ng g(-1) in sediments, and from 2.4 ng g(-1) to 11.1 ng g(-1) in oyster shells. Total inorganic tin concentrations ranged from 1775.0 ng g(-1) to 4781.3 ng g(-1) in oyster shells. The amount of BTs in oyster shells has been associated with the concentrations in the sediments trapped in the shell chambers. Partition coefficients between oyster sediments and oyster shells show the affinity of BTs by the sediments and the higher inorganic tin in oyster shells does not seem to be related to the BTs pollution.

Dielectron production in 12C+12C collisions at 2A GeV with the HADES spectrometer

The invariant-mass spectrum of e+e- pairs produced in 12C+12C collisions at an incident energy of 2 GeV per nucleon has been measured for the first time. The measured pair production probabilities span over 5 orders of magnitude from the pi(0)-Dalitz to the rho/omega invariant-mass region. Dalitz decays of pi(0) and eta account for all the yield up to 0.15 GeV/c(2), but for only about 50% above this mass. A comparison with model calculations shows that the excess pair yield is likely due to baryon-resonance and vector-meson decays. Transport calculations based on vacuum spectral functions fail, however, to describe the entire mass region.

Regulation of autophagy by the inositol trisphosphate receptor

The reduction of intracellular 1,4,5-inositol trisphosphate (IP(3)) levels stimulates autophagy, whereas the enhancement of IP(3) levels inhibits autophagy induced by nutrient depletion. Here, we show that knockdown of the IP(3) receptor (IP(3)R) with small interfering RNAs and pharmacological IP(3)R blockade is a strong stimulus for the induction of autophagy. The IP(3)R is known to reside in the membranes of the endoplasmic reticulum (ER) as well as within ER-mitochondrial contact sites, and IP(3)R blockade triggered the autophagy of both ER and mitochondria, as exactly observed in starvation-induced autophagy. ER stressors such as tunicamycin and thapsigargin also induced autophagy of ER and, to less extent, of mitochondria. Autophagy triggered by starvation or IP(3)R blockade was inhibited by Bcl-2 and Bcl-X(L) specifically targeted to ER but not Bcl-2 or Bcl-X(L) proteins targeted to mitochondria. In contrast, ER stress-induced autophagy was not inhibited by Bcl-2 and Bcl-X(L). Autophagy promoted by IP(3)R inhibition could not be attributed to a modulation of steady-state Ca(2+) levels in the ER or in the cytosol, yet involved the obligate contribution of Beclin-1, autophagy-related gene (Atg)5, Atg10, Atg12 and hVps34. Altogether, these results strongly suggest that IP(3)R exerts a major role in the physiological control of autophagy.

Results of the regional intercomparison exercise for the determination of operational quantity HP(10) in Latin America

Several intercomparison exercises were organised by the International Atomic Energy Agency (IAEA) on the determination of operational quantities at the regional or interregional basis. In the Latin American region an intercomparison for the determination of the operational quantity Hp(10) was completed mid-2004, as a follow-up to previous exercises carried out during the 1990s. Eighteen individual external monitoring services from nineteen Member States participated in the first phase. The second phase grouped 15 services that had participated in the first phase. Dosemeter irradiations in photon beams were done by four Secondary Standard Dosimetry Laboratories (SSDLs) of the region. The preparation of this exercises involved an audit by the IAEA SSDL, where reference irradiations were provided to all participants for verification of their systems. During the first phase (2002-2003) only 9 out of 18 services met the performance requirements for such monitoring services. Necessary corrective actions and procedure verification were implemented. During the second phase (2004) 11 out of 15 services fulfilled the performance criteria. This intercomparison shows that there has been improvement in the second phase and most participants demonstrated a satisfactory performance of the quantity tested.

Real-time system for high-image resolution disparity estimation

We present the hardware implementation of a simple, fast technique for depth estimation based on phase measurement. This technique avoids the problem of phase warping and is much less susceptible to camera noise and distortion than standard block-matching stereo systems. The architecture exploits the parallel computing resources of FPGA devices to achieve a computation speed of 65 megapixels per second. For this purpose, we have designed a fine-grain pipeline structure that can be arranged with a customized frame-grabber module to process 52 frames per second at a resolution of 1280 x 960 pixels. We have measured the system's degradation due to bit quantization errors and compared its performance with other previous approaches. We have also used different Gabor-scale circuits, which can be selected by the user according to the application addressed and typical image structure in the target scenario.

A phase-based stereo vision system-on-a-chip

A simple and fast technique for depth estimation based on phase measurement has been adopted for the implementation of a real-time stereo system with sub-pixel resolution on an FPGA device. The technique avoids the attendant problem of phase warping. The designed system takes full advantage of the inherent processing parallelism and segmentation capabilities of FPGA devices to achieve a computation speed of 65megapixels/s, which can be arranged with a customized frame-grabber module to process 211frames/s at a size of 640x480 pixels. The processing speed achieved is higher than conventional camera frame rates, thus allowing the system to extract multiple estimations and be used as a platform to evaluate integration schemes of a population of neurons without increasing hardware resource demands.

[Degree of public awareness regarding intensive care units (ICUs) and intensive care physicians in Castilla y León]

AIM

To determine degree of public awareness regarding the activities and health care professionals that comprise intensive care units (ICUs) in the autonomous community of Castilla y León.

DESIGN

Questionaire in the form of a true-false test dealing with a) description of an ICU; b) description of ICU patients, and c) degrees and qualifications held by ICU physicians.

LOCATION

Waiting rooms of outpatient clinics and ICUs of 9 hospitals in Castilla y León.

SUBJECTS AND METHODS

During the period from 1 October 2003 to 29 February 2004, there were surveyed a group of those persons accompanying outpatients arriving for appointments (OP, n = 2,293), and a group comprised of relatives of ICU patients (ICU, n = 727) upon discharge from the ICU.

RESULTS

The average age of those subjects surveyed was 45.6 years old. 62.1% were women and 52.8% had received education through secondary level or higher. Of the 1,354 analyzed OP questionnaires, 27.7%, 25.5% and 48.4% responded correctly to questions A, B and C, respectively. Of the 284 analyzed ICU questionnaires, 38.6%, 41.0%, and 63.5% responded correctly to questions A, B and C, respectively. Differences between results from the two surveyed groups were statistically significant, and the best results from the ICU group were found among those subjects whose family members had remained in ICU for 2 days or more.

CONCLUSIONS

In the described scope, of the citizens of Castilla y León, 27.7% know as it is a ICU, 25.5% know what type of patients usually is entered there, and 48.4% recognize their doctors like ICU specialists specifically. These knowledge improve significantly after having some relative entered in ICU for more than 2 days.