Indoor radon risk mapping of the Canary Islands using a methodology for volcanic islands combining geological information and terrestrial gamma radiation data

Within the framework of the recent approval of the National Plan Against Radon by the Council of Ministers of the Spanish Government, one of its five axes focuses on the delimitation of priority action areas. In line with this objective, this paper presents the indoor radon risk maps of the Canary Islands. Due to the volcanic origin of the Canary Islands, there is a great deal of geological heterogeneity in the soils on which buildings settle, making it very difficult to delimit radon-risk areas in the process of creating maps. Following a methodology developed in previous works for a study area formed of a set of representative municipalities, this paper presents radon risk maps of the Canary Islands based on lithostratigraphic information and high-resolution terrestrial gamma radiation maps. The goodness of fit of these maps is verified based on a statistical analysis of indoor radon concentration measurements carried out at representative building enclosures. In order to analyse the level of risk to the population, these maps were combined with built up areas (urban fabric) maps and estimations of the annual effective doses due to radon was obtained by applying a dosimetric model. This methodology improves the capability to delimit indoor radon risk areas, with a greater margin of safety. In this respect, it is estimated that areas classified as low risk have indoor radon concentrations 41 % below the current reference level of 300 Bq/m3 established by national regulations in compliance with the precepts laid down in the European EURATOM Directive.

Food web of the oceanic region of the archipelago of Madeira: The role of marine megafauna in the subtropical northeast Atlantic ecosystem

Many oceanic areas are still in need of baseline information on their structure and functioning. This is particularly important due to the ever-increasing impacts of global changes, which have led to the decline of marine life, and top predators in particular. The study of the structure and functioning of food webs can help understand the consequences of the disappearance of this group in marine ecosystems. Here, we develop a mass-balanced model for the marine Exclusive Economic Zone of the archipelago of Madeira, with emphasis on the role of marine megafauna in this ecosystem. A total of 50 functional groups were defined, representing coastal and open ocean areas, and epipelagic and deep-sea levels. The total biomass of the Madeira system was calculated at 52.68 t km-2, with lower trophic level organisms comprising 89.9 % of its biomass. Marine megafauna, namely pelagic sharks and coastal birds had the highest impacts across other trophic levels and were classified as keystone species, together with monk seals. The food web was characterized by a linear-like food chain, with a large proportion of specialized organisms, including dolphins, shearwaters, and large pelagic fish. The low mean trophic level of the system was 2.03, much lower than that of fisheries (4.3) targeting mainly tunas and Black scabbardfish. Considering the importance of marine megafauna in this food web and the threats they are facing; monitoring studies of key species in the region should be a priority. This study can now be used to build a needed ecosystem-based fisheries management and integrate conservation measures to declining species.

Farmland practices are driving bird population decline across Europe

Declines in European bird populations are reported for decades but the direct effect of major anthropogenic pressures on such declines remains unquantified. Causal relationships between pressures and bird population responses are difficult to identify as pressures interact at different spatial scales and responses vary among species. Here, we uncover direct relationships between population time-series of 170 common bird species, monitored at more than 20,000 sites in 28 European countries, over 37 y, and four widespread anthropogenic pressures: agricultural intensification, change in forest cover, urbanisation and temperature change over the last decades. We quantify the influence of each pressure on population time-series and its importance relative to other pressures, and we identify traits of most affected species. We find that agricultural intensification, in particular pesticides and fertiliser use, is the main pressure for most bird population declines, especially for invertebrate feeders. Responses to changes in forest cover, urbanisation and temperature are more species-specific. Specifically, forest cover is associated with a positive effect and growing urbanisation with a negative effect on population dynamics, while temperature change has an effect on the dynamics of a large number of bird populations, the magnitude and direction of which depend on species' thermal preferences. Our results not only confirm the pervasive and strong effects of anthropogenic pressures on common breeding birds, but quantify the relative strength of these effects stressing the urgent need for transformative changes in the way of inhabiting the world in European countries, if bird populations shall have a chance of recovering.

Multiparametric analysis for the determination of radon potential areas in buildings on different soils of volcanic origin

The transposition of the European EURATOM directive into the regulations of the different member states of the European Union involved governments making great efforts to define priority action maps against indoor radon exposure in buildings over a short time period. In Spain, the Technical Building Code established 300 Bq/m³ as a reference level and set up a classification of municipalities in which remediation measures should be adopted for radon exposure in buildings. Oceanic volcanic islands, such as the Canary Islands, present high geological heterogeneity in a small space due to their volcanic origin. This variability poses a challenge to the elaboration of radiological risk maps, which makes it necessary to have a high density of data to collect local variations. This paper presents a methodology to obtain accurate radon risk maps based on geological criteria and terrestrial gamma radiation. The predictive efficiency of these maps is statistically verified using indoor radon concentration data measured in buildings. Other radiological variables, which are commonly used as criteria for radon risk prediction found in the literature, were also applied, such as the geogenic radon potential and the activity concentration of natural radioisotopes in soils. The higher resolution of the maps obtained allows for a more detailed classification of radon risk zones in the study area than the current risk maps published in the Spanish building regulations.

Methodology for determination of radon prone areas combining the definition of a representative building enclosure and measurements of terrestrial gamma radiation

The recommendations of the European Atomic Energy Community (EURATOM) have recently been incorporated into Spanish regulations in the Basic Document of Health Standards of the Technical Building Code (CTE), section HS6, on protection against radon exposure. This further accentuates the need to delimit radon prone areas as a strategy to address measures which minimise the effects of this gas on the population. In this research, measurements of terrestrial gamma radiation and indoor radon of dwellings have been carried out in the same location to delimit these risk areas. A new methodology has been developed including a definition of a Representative Building Enclosure (RBE) and it is proposed a Building Storey Index (I_BS) which allows normalizing measurements of indoor radon activity concentration taken in different levels from the ground to the RBE. The results show the need to consider the type of contact that exists between the building and the ground as a determining factor of radon risk. Terrestrial gamma radiation is used as a proxy for radioisotopic composition of soils to characterise the indoor radon risk at different geological formation.

Long-term and large-scale multispecies dataset tracking population changes of common European breeding birds

Around fifteen thousand fieldworkers annually count breeding birds using standardized protocols in 28 European countries. The observations are collected by using country-specific and standardized protocols, validated, summarized and finally used for the production of continent-wide annual and long-term indices of population size changes of 170 species. Here, we present the database and provide a detailed summary of the methodology used for fieldwork and calculation of the relative population size change estimates. We also provide a brief overview of how the data are used in research, conservation and policy. We believe this unique database, based on decades of bird monitoring alongside the comprehensive summary of its methodology, will facilitate and encourage further use of the Pan-European Common Bird Monitoring Scheme results.

Seabird diet analysis suggests sudden shift in the pelagic communities of the subtropical Northeast Atlantic

The dynamics of the subtropical pelagic ecosystems of the Northeast Atlantic are still poorly known due to the high costs associated with sampling large oceanic areas. Top predators can be used as alternative low-cost samplers and indicators of the temporal variability of such systems. To study the variation in the composition of pelagic species through time in the broad Canary current region, we analysed foraging trips and regurgitations of Cory's shearwaters Calonectris borealis nesting on Selvagens islands, in 2008-2011 and 2016-2018. Fisheries data, oceanographic variables and the North Atlantic Oscillation were explored as possible explanatory variables for trends in behaviour and diet. Cory's shearwaters' diet, complemented by fisheries data, revealed marked changes in the composition of the pelagic fish communities. In 2016 there was a peak in the abundance of the Atlantic chub mackerel Scomber colias, followed by an explosive increase in the abundance of the Longspine snipefish Macroramphosus scolopax in 2017 and 2018, as deduced from the diet composition of the Cory's shearwater, and supported by fisheries data, in the broad oceanic area surrounding the Selvagens islands. Oceanographic variables did not show fluctuations correlated with these marked shifts in pelagic fish availability, the causes of which remain largely unknown. This study highlights the importance of the Atlantic chub mackerel and of the Longspine snipefish in the Madeira/Canary region and exemplifies the efficiency of avian predators in revealing rapid changes in pelagic communities of oceanic domains. Such trends and variations need to be better monitored and understood to measure the impact of ongoing global changes and to sustainably manage the marine environment and resources.

Regional variation in the impacts of the COVID-19 pandemic on the quantity and quality of data collected by the project eBird

The COVID-19 pandemic has likely affected natural systems around the world; the curtailment of human activity has also affected the collection of data needed to identify the indirect effects of this pandemic on natural systems. We describe how the outbreak of COVID-19 disease, and associated stay-at-home orders in four political regions, have affected the quantity and quality of data collected by participants in one volunteer-based bird monitoring project, eBird. The four regions were selected both for their early and prolonged periods of mandated changes to human activity, and because of the high densities of observations collected. We compared the months of April 2020 with April in previous years. The most notable change was in the landscapes in which observations were made: in all but one region human-dominated landscapes were proportionally more common in the data in April 2020, and observations made near the rarer wetland habitat were less prevalent. We also found subtler changes in quantity of data collected, as well as in observer effort within observation periods. Finally, we found that these effects of COVID-19 disease varied across the political units, and thus we conclude that any analyses of eBird data will require region-specific examination of whether there have been any changes to the data collection process during the COVID-19 pandemic that would need to be taken into account.

Frequency, profile and results of patients with acute heart failure transferred directly to home hospitalisation from emergency departments

OBJECTIVE

To describe the frequency, clinical characteristics and outcomes of patients with acute heart failure (AHF) transferred directly from emergency departments to home hospitalisation (HH) and to compare them with those hospitalised in internal medicine (IM) or short-stay units (SSU).

METHOD

We included patients with AHF transferred to HH by hospitals that considered this option during the Epidemiology of Acute Heart Failure in Spanish Emergency Departments (EAHFE) 4-5-6 Registries and compared them with patients admitted to IM or SSU in these centres. We compared the adjusted all-cause mortality at 1 year and adverse events 30 days after discharge.

RESULTS

The study included 1473 patients (HH/IM/SSU: 68/979/384). The HH rate was 4.7% (95% CI, 3.8-6.0%). The patients in HH had few differences compared with those hospitalised in IM and SSUs. The HH mortality was 1.5%, and the HH median stay was 7.5 days (IQR, 4.5-12), similar to that of IM (median stay, 8 days; IQR, 5-13; p=.106) and longer than that of SSU (median stay, 4 days; IQR, 3-7; p<.001). The all-cause mortality at 1 year for HH did not differ from that of IM (HR, 0.91; 95% CI, 0.73-1.14) or SSU (HR, 0.77; 95% CI, 0.46-1.27); however, the emergency department readmission rate during the 30 days postdischarge was lower than that of IM (HR, 0.50; 95% CI, 0.25-0.97) and SSU (HR, 0.37; 95% CI, 0.19-0.74). There were no differences in the need for new hospitalisations or in the 30-day mortality rate.

CONCLUSIONS

Direct transfer from the emergency department to HH is infrequent despite being a safe option for a certain patient profile with AHF.

Frequency, profile, and outcomes of patients with acute heart failure transferred directly to home hospitalization from emergency departments

OBJECTIVE

To describe the frequency, clinical characteristics and outcomes of patients with acute heart failure (AHF) transferred directly from emergency departments to home hospitalisation (HH) and to compare them with those hospitalised in internal medicine (IM) or short-stay units (SSU).

METHOD

We included patients with AHF transferred to HH by hospitals that considered this option during the Epidemiology of Acute Heart Failure in Spanish Emergency Departments (EAHFE) 4-5-6 Registries and compared them with patients admitted to IM or SSU in these centres. We compared the adjusted all-cause mortality at 1 year and adverse events 30 days after discharge.

RESULTS

The study included 1473 patients (HH/IM/SSU:68/979/384). The HH rate was 4.7% (95% CI 3.8-6.0%). The patients in HH had few differences compared with those hospitalised in IM and SSUs. The HH mortality was 1.5%, and the HH median stay was 7.5 days (IQR, 4.5-12), similar to that of IM (median stay, 8 days; IQR, 5-13; p = .106) and longer than that of SSU (median stay, 4 days; IQR, 3-7; p < .001). The all-cause mortality at 1 year for HH did not differ from that of IM (HR, 0.91; 95% CI 0.73-1.14) or SSU (HR, 0.77; 95% CI 0.46-1.27); however, the emergency department readmission rate during the 30 days postdischarge was lower than that of IM (HR, 0.50; 95% CI 0.25-0.97) and SSU (HR, 0.37; 95% CI 0.19-0.74). There were no differences in the need for new hospitalisations or in the 30-day mortality rate.

CONCLUSIONS

Direct transfer from the emergency department to HH is infrequent despite being a safe option for a certain patient profile with AHF.

Assessment of radon risk areas in the Eastern Canary Islands using soil radon gas concentration and gas permeability of soils

The Basic Safety Standard (BSS) Directive 2013/59/EURATOM of the European Union (EU) has stated the need for member states to establish national action plans to mitigate their general population's long-term risks of exposure to radon gas. Maps of radon-prone areas provide a useful tool for the development of such plans. This paper presents the maps of radon-prone areas in the Eastern Canary Islands (Gran Canaria, Fuerteventura and Lanzarote) obtained from assessment of Geogenic Radon Potential (GRP) distribution in the territory. GRP constitutes a magnitude that is contingent on both radon activity concentration and gas permeability of soils. An extensive campaign covering all geological formations of the Eastern Canary Islands was undertaken to locally sample these parameters. Geostatistical analysis of the spatial distribution of radon concentration in soils, permeability and GRP was performed on each of the islands, and the relationship between these magnitudes and the characteristic geological formations of the volcanic islands was investigated. Areas dominated by basic volcanic and plutonic rocks (originated by both recent and ancient volcanism) exhibit relatively low levels of radon in soils, and with the exception of specific cases of very high permeability, these areas are not classified as prone to radon risk according to international criteria. Areas in which intermediate or acidic volcanic and plutonic rocks predominate are characterised by greater radon activity concentration in soils, rendering them radon-prone. Given these results, Lanzarote is classified as an island with low radon risk all over its surface; Fuerteventura presents low-medium risk; and Gran Canaria contains extensive areas in the centre and north where the risk is medium or high. This classification is consistent with the risk maps obtained by National and European agencies from indoor radon measurements conducted on these islands.

Natural radioactivity in algae arrivals on the Canary coast and dosimetry assessment

Nowadays, the use of wild and culture harvest seaweed in food industry is a booming productive sector. In this context, a radiological characterization of five globally common seaweed species that were collected in arrival on Gran Canaria coast was carried out. The studied algae species were Cymopolia barbata, Lobophora variegata, Sargassum vulgare, Dictyota dichotoma and Haliptilon virgatum. Radionuclides analysed by alpha and gamma spectrometry were ²³⁸U, ²³⁴U, ²³⁵U, ²¹⁰Po, ²³⁴Th, ²²⁶Ra, ²¹⁰Pb, ²²⁸Th, ²²⁴Ra, ⁴⁰K and ⁷Be. Activity concentrations, ratios, and concentration factors (CF) were determined for all samples collected. The CF in algae was higher for reactive-particle radionuclides (²¹⁰Po, ²³⁴Th, ²²⁸Th and ²¹⁰Pb) than for conservative ones (⁴⁰K and the uranium isotopes). ²¹⁰Po, ²²⁸Th and ²³⁴Th CF were one or two orders of magnitude higher than those recommended by the IAEA. L. variegata, C. barbata and S. vulgare showed a clear preference for ²¹⁰Pb and ²¹⁰Po, for uranium radioisotopes, and for ⁴⁰K and ²³⁴Th, respectively. A dosimetry assessment due to seaweed ingestion showed considerable values of annual committed effective dose for H. virgatum (605 ± 19 μSv/y), L. variegata (574 ± 17 μSv/y) and D. dichotoma (540 ± 30 μSv/y). Hence, this study suggests that an algae radiological characterization is recommended as part of the product valorising process.

EU protected area network did not prevent a country wide population decline in a threatened grassland bird

Background

Few studies have assessed the effectiveness of the Protected Area networks on the conservation status of target species. Here, we assess the effectiveness of the Portuguese Natura 2000 (the European Union network of protected areas) in maintaining a species included in the Annex I of the Bird Directive, namely the population of a priority farmland bird, the little bustard Tetrax tetrax.

Methods

We measured the effectiveness of the Natura 2000 by comparing population trends across time (2003–2006 and 2016) in 51 areas, 21 of which within 12 Special Protection Areas (SPA) that were mostly designated for farmland bird conservation and another 30 areas without EU protection.

Results

Overall, the national population is estimated to have declined 49% over the last 10–14 years. This loss was found to be proportionally larger outside SPA (64% decline) compared to losses within SPA (25% decline). However, the absolute male density decline was significantly larger within SPA .

Discussion

In spite of holding higher population densities and having prevented habitat loss, we conclude that Natura 2000 was not effective in buffering against the overall bustard population decline. Results show that the mere designation of SPA in farmland is not enough to secure species populations and has to be combined with agricultural policies and investment to maintain not only habitat availability but also habitat quality.

Mapping natural radioactivity of soils in the eastern Canary Islands

The Canary Islands archipielago (Spain) comprises seven main volcanic islands and several islets that form a chain extending for around 500 km across the eastern Atlantic, between latitudes 27°N and 30°N, with its eastern edge only 100 km from the NW African coast. The administrative province of Las Palmas comprises the three eastern Canary Islands (Lanzarote, Fuerteventura and Gran Canaria). An extensive study of terrestrial gamma dose rates in surface soils has been carried out to cover the entire territory of the province (4093 km²). The average outdoor gamma dose rate in air at 1 m above ground is 73 nGyh^-1 at Gran Canaria, 32 nGyh^-1 at Fuerteventura, and 25 nGyh^-1 at Lanzarote. To complete the radiological characterization of this volcanic area, 350 soil samples at 0-5 cm depth were collected to cover all the geologic typologies of the islands. These samples were measured using high resolution gamma spectrometry to determine the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K. The average values obtained were 25.2 Bq/kg, 28.9 Bq/kg, and 384.4 Bq/kg, respectively. Maps of terrestrial gamma activity, effective dose, and activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K for the region have been developed through the use of geostatistical interpolation techniques. These maps are in accord with the geology of the islands.

A simple methodology for characterization of germanium coaxial detectors by using Monte Carlo simulation and evolutionary algorithms

The determination in a sample of the activity concentration of a specific radionuclide by gamma spectrometry needs to know the full energy peak efficiency (FEPE) for the energy of interest. The difficulties related to the experimental calibration make it advisable to have alternative methods for FEPE determination, such as the simulation of the transport of photons in the crystal by the Monte Carlo method, which requires an accurate knowledge of the characteristics and geometry of the detector. The characterization process is mainly carried out by Canberra Industries Inc. using proprietary techniques and methodologies developed by that company. It is a costly procedure (due to shipping and to the cost of the process itself) and for some research laboratories an alternative in situ procedure can be very useful. The main goal of this paper is to find an alternative to this costly characterization process, by establishing a method for optimizing the parameters of characterizing the detector, through a computational procedure which could be reproduced at a standard research lab. This method consists in the determination of the detector geometric parameters by using Monte Carlo simulation in parallel with an optimization process, based on evolutionary algorithms, starting from a set of reference FEPEs determined experimentally or computationally. The proposed method has proven to be effective and simple to implement. It provides a set of characterization parameters which it has been successfully validated for different source-detector geometries, and also for a wide range of environmental samples and certified materials.

Thyroid stimulating hormone directly modulates cardiac electrical activity

BACKGROUND

The electrocardiogram of hypothyroid patients shows a series of abnormalities of cardiac repolarization due to a reduction of some repolarizing K(+) currents and an increase of the L-type calcium current. Experimental and clinical works call into question the unique role of T3 and T4 in these mechanisms and correlate increased serum TSH levels with the repolarization abnormalities in patients with both subclinical and overt hypothyroidism. In this context, the aim of the present study was to investigate the direct effects of TSH upon cardiac electrical properties.

METHODS

The action potential recording and the ion channel subunits mRNA expression were obtained from left ventricle of adult rats. Additionally, the repolarizing K(+) currents and the L-type Ca(2+) current (ICa-L) were recorded in isolated rat adult ventricular myocytes by the patch-clamp technique.

RESULTS

24h exposure to TSH lengthened the action potential and slightly depolarized the resting membrane potential. TSH- receptor activation causes a reduction of the amplitude of Ito and IK1 currents caused by a reduction in channels expression. However, TSH had no effect on ICa-L, IK or IKur.

CONCLUSION

These results support the idea that some of the electrical disturbances seen in hypothyroid hearts, such as the Ito and IK1 current reduction, could be caused not by low T3 but by the elevation of circulating TSH.

An holistic ecological analysis of the diet of Cory's shearwaters using prey morphological characters and DNA barcoding

Knowledge of the dietary choices and trophic niches of organisms is the key to understanding their roles in ecosystems. In seabird diet studies, prey identification is a difficult challenge, often yielding results with technique-specific biases. Additionally, sampling efforts are often not extensive enough to reveal intrapopulational variation. Immature animals, which may constitute up to 50% of a population, may occupy a significantly different trophic niche to more experienced birds, but this remains largely unexplored. We investigated the diet of Cory's shearwater (Calonectris diomedea) from Selvagem Grande, an island located off the northwest African coast, collecting a total of 698 regurgitate samples over three consecutive breeding seasons. The diet was assessed using two complementary approaches for prey identification: conventional morphological analysis (using fish vertebrae, otoliths and cephalopod beaks) and DNA barcoding of the 16S rRNA mitochondrial gene, in cases where a positive identification could not be retrieved. Species assignments employed BLAST and distance-based methods, as well as direct optimization of the tree length based on unaligned sequences in POY. This method resulted in robust tree estimates and species assignments, showing its potential for DNA barcoding of stomach contents using hypervariable markers such as the 16S. The molecular approach increased taxonomic resolution and revealed an additional 17 taxa. Diet differed significantly according to breeding status, sex, breeding phase (prelaying and chick rearing) and year. Such direct evidence of trophic segregation within the same population has rarely been shown in seabirds and highlights the importance of including such variables in ecosystem-based management approaches.

Natural radioactivity measurements of beach sands in Gran Canaria, Canary Islands (Spain)

Concentrations of natural radionuclides (226)Ra, (232)Th, (40)K and man-made (137)Cs in most important tourist Gran Canaria beaches have been determined using a high-purity Germanium detector to analyse their radiological hazard. Average values of the activity concentrations of (226)Ra, (232)Th and (40)K were 17.6±1.4, 21.3±1.8 and 480±22 Bq kg(-1), respectively. Observed activity concentration values of (137)Cs were practically negligible from a radiological protection point of view. The results of this paper were compared with others published in the bibliography for beaches and coastal sediments of different countries. The mean external air absorbed dose rate was 43.9±2.8 nGyh(-1), which resulted in an outdoor annual effective dose below the world average. Also, the radium equivalent and the external hazard index were calculated. Results from Gran Canaria beaches showed the low levels of radioactivity, indicating no significant radiological risk related to human activities in the area.

Differential clinical characteristics and outcome predictors of acute heart failure in elderly patients

OBJECTIVE

We determined the clinical-epidemiological characteristics and prognostic factors of early mortality and re-consultation in an elderly population attending the hospital emergency department (HED) for acute heart failure (AHF).

PATIENTS AND METHODS

A prospective, observational, non interventional study including all the patients with AHF attended in the Spanish's HED. Two groups were defined: elderly (≥ 80 years) and controls (< 80 years).

VARIABLES

demographic characteristics, comorbidity, degree of cardiac involvement, previous treatment, symptoms and signs of the AHF episode, precipitating factors, treatment in the HED and outcome.

OUTCOME VARIABLES

mortality and re-consultation within 30 days.

RESULTS

Of the 942 patients included, 455 of whom were elderly (48.3%). In this elderly population female sex, auricular fibrillation and a history of ictus and a poor functional status predominated. The type of ventricular dysfunction was unknown in 70%. No main differences in the presentation of AHF were found between the two groups. Mortality and re-consultation to the HED within 30 days were similar in both groups. While several factors were identified to be related to mortality or re-consultation in control group, in the elderly group it was more difficult to identify patients who will die or re-consult to the HED within the following 30 days. Only respiratory insufficiency on arrival to the HED was found to predict a greater probability of death (OR 3.55; CI95% 1.39-9.11).

CONCLUSIONS

AHF in elderly patients presents some differential characteristics and, most importantly, it is more difficult to identify which of these patients will die or re-consult in the short-term.

Breaking the routine: individual Cory's shearwaters shift winter destinations between hemispheres and across ocean basins

There is growing evidence that migratory species are particularly vulnerable to rapid environmental changes arising from human activity. Species are expected to vary in their capacity to respond to these changes: long-distance migrants and those lacking variability in migratory traits are probably at considerable disadvantage. The few studies that have assessed the degree of plasticity in behaviour of marine animals suggest that fidelity to non-breeding destinations is usually high. In the present study, we evaluated individual flexibility in migration strategy of a highly pelagic seabird, the Cory's shearwater Calonectris diomedea. Geolocation data from 72 different migrations, including 14 birds that were tracked for more than one non-breeding season, showed a remarkable capacity to change winter destinations between years. Although some birds exhibited high site fidelity, others shifted from the South to North Atlantic, from the western to eastern South Atlantic, and from the Atlantic to Indian Ocean. Individuals also showed flexibility in stopover behaviour and migratory schedule. Although their K-selected life-history strategy has the disadvantage that the chances of microevolution are slight if circumstances alter rapidly, these results suggest that Cory's shearwaters may be in a better position than many other long-distance migrants to face the consequences of a changing environment.

A target control Infusion method for neuromuscular blockade based on hybrid parameter estimation

The paper presents a new method for target control infusion (TCI) for neuromuscular blockade (NMB) level control of patients subject to general anaesthesia. The method combines an inversion of the pharmacokinetic/pharmacodynamic (PK/PD) model with a hybrid parameter estimation method that uses on-line data from the initial bolus response to estimate the model parameters. Although atracurium is considered as relaxant, the newly proposed method may be applied to other drugs for which the PK/PD model is available. Simulation results on a bank of 100 patient models are presented to demonstrate the achievable performance.

Tau protein concentrations in cerebrospinal fluid of patients with amyotrophic lateral sclerosis

OBJECTIVE

To elucidate whether cerebrospinal fluid (CSF) concentrations of the microtubule-associated tau protein are related to the risk for sporadic amyotrophic lateral sclerosis (SALS).

PATIENTS/METHODS

We measured tau concentrations in the CSF of 18 patients with SALS and 75 age- and sex-matched controls, using a specific ELISA method.

RESULTS

The mean CSF concentrations of tau protein did not differ significantly between SALS patient and control groups, were not influenced by the clinical form (spinal vs bulbar) of ALS, and were not correlated with age, age at onset, and duration of the disease.

CONCLUSIONS

CSF tau concentrations are not a biochemical marker of ALS.

[Huntington's disease mimicking Tourette syndrome]

AIM

To report a patient with Huntington's disease, confirmed by a molecular genetic study, presenting with clinical features suggesting Tourette's syndrome.

CASE REPORT

A thirty-years male with personal antecedents of perinatal hypoxia, but normal development; and family history (paternal grandfather) of 'abnormal repetitive movements of the upper limbs' of adult onset. He had multiple motor tics since teenage, and associated vocal tics, bruxism, and compulsions with auto-and heteroaggresivity. Neurological examination showed motor tics in the orolingual area and occasional vocal tics. Neuropsychological examination showed a mild impairment of short-term memory and language. Analytical studies including blood smears to see acanthocytes and copper metabolism studies were normal, as it was a MRI imaging. The molecular genetic study of the patient showed 46 repeats of CAG triplets in the exon 1 of the IT-15 genes, while his father (who was asymptomatic) showed 40 repeats. It was not possible to study the paternal grandfather.

CONCLUSIONS

The clinical onset of Huntington's disease mimicking Tourette's syndrome is infrequent. This diagnosis should be taken in mind in patients with possible Tourette's syndrome and atypical neuropsychiatric features.

Risk-specific nosocomial infection rates

Because nosocomial infection rates vary by hospital area and service, most infection control programs calculate area-specific rates to augment the reporting of their hospital-wide data. Rate development is often limited by the availability of appropriate specific denominator data to support important comparisons. Our university hospital reports a 20 month experience in which numerator data was collected as per the National Nosocomial Infections Surveillance System criteria for hospital-wide, high-risk nursery and ICU surveillance. These data were then combined with data in our hospital's patient-specific denominator file. This has enabled the development of risk-specific infection rates based on the analytic control of important variables available in both the numerator and denominator files. We found rate differences that were length of stay cohort specific, hospital day specific, age specific, birthweight specific, and survival cohort specific when examining our data by both the cumulative incidence and incidence density methods.