Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 85
Filter
1.
Parasitol Res ; 122(7): 1499-1507, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37093300

ABSTRACT

The helminth fauna present in the gut contents of Iberian adders, Vipera seoanei (Squamata: Viperidae), were characterised and analysed in respect to biological and eco-geographic factors that may affect the occurrence and diversity of helminths in this species. A total of 317 samples of preserved stomachs and intestines, covering the distributional range of V. seoanei, were examined. Similar to other Vipera species from the Iberian Peninsula, the helminth fauna was also impoverished in V. seoanei, but unlike other Vipera species from Central and East Europe, helminths were mostly found in adult vipers, and occurred in vipers located at the periphery of the species range, characterised by low elevation, high temperature and precipitation levels, and abundant pastures.


Subject(s)
Helminths , Viperidae , Animals , Viperidae/parasitology , Helminths/isolation & purification
2.
Appl Radiat Isot ; 185: 110221, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35427836

ABSTRACT

The possible damaging effects on human health of inhaled radon and its decay products are of interest to workers and the public. In particular, radon in thermal environments often occurs in high concentrations. Therefore, investigations and remedial actions are important to reduce activity concentration values and associated risk. This work concerns the analysis of two surveys of radon gas activity concentration carried out in 2006/2007 and 2019/2020 at twenty thermal spas on the island of Ischia (Italy). Annual measurements were carried out in workplaces located in the basement and ground floor using passive CR-39 detectors. In the spas involved in both surveys, the effectiveness of the remedial actions, implemented by the owners, was assessed obtaining an average percentage reduction of 74%. Considerations were made about the annual effective dose, and the location of the spas taking into account the geological setting of the volcanic nature of the island.


Subject(s)
Air Pollutants, Radioactive , Air Pollution, Indoor , Occupational Exposure , Radiation Monitoring , Radon , Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Humans , Italy , Occupational Exposure/analysis , Radiation Monitoring/methods , Radon/analysis
3.
Radiat Prot Dosimetry ; 191(2): 154-159, 2020 Nov 27.
Article in English | MEDLINE | ID: mdl-33125480

ABSTRACT

The most used passive detectors for Radon measurement are the CR39s, both for the good stability of the material and for the practicality of use. But, commercial reading systems are expensive and not always fast. The aim of the present work was the development of a method for a rapid, efficient and economic evaluation of the result of the indoor Radon measurement performed with CR39 detectors. The analysis and acquisition of detector images were performed using a photo scanner and the free ImageJ software. Several groups of CR-39 detectors were exposed, developed and analysed. Calibration curve was obtained in a wide range of exposure values (200-12 000 kBq·h·m -3) to allow the procedure to be applied in all possible measurement environments. Furthermore, a statistical study was carried out on the shape and size of nuclear tracks after chemical development. The dependence of the track size on Radon exposure was effective in showing the trace saturation effect as well.


Subject(s)
Air Pollutants, Radioactive , Air Pollution, Indoor , Radiation Monitoring , Radon , Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Alpha Particles , Polyethylene Glycols , Radon/analysis
4.
Appl Radiat Isot ; 166: 109385, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32979758

ABSTRACT

Studies concerning 222Rn emission from soils are growing interest in the Earth Sciences, due to the gas potential as a tracer of natural phenomena. This paper presents a study of radon monitoring in two sites of Campi Flegrei caldera (Neaples, Italy) during the period July 1, 2011-December 31, 2017. This area was characterized by several phases of volcanic unrest. A hybrid method based on Multiple Linear Regression + Remote Radon Estimation method + Singular Spectrum Analysis (MLR + RRE + SSA) is developed for the trend extraction and the identification of anomalies in the time series of 222Rn. The results are compared with several routinely used geo-indicators of the caldera unrest. The comparisons show strong correlation among the signals. The present study proves the 222Rn is a potential indicator of the evolution of a volcanic crisis.

5.
Appl Radiat Isot ; 166: 109310, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32814306

ABSTRACT

The interest in the measurement of thoron (220Rn) activity concentration in air has recently increased, with the attention for the development of standards useful for the calibration of measuring instruments. Due to its short half-life (55.8 s), consolidated techniques for the realization and the use of controlled atmospheres of radon (222Rn) are not effective in the case of thoron. New adequate methodology are required. A method for the measurement of the thoron reference activity based on the direct detection of the alpha particles produced by the decay of 220Rn, from natural samples containing 232Th, is here proposed. The possibility of observing an acceptable spectrum is entrusted to the realization of measurement chambers small enough to reduce as much as possible the energy loss of the alpha particles before they reach the Silicon detector. Such a chamber was realized and used with a known thoron atmosphere in a controlled environment. The experimental results are compared with those obtained from the simulation with the Monte Carlo method: (i) the alpha spectra coming directly from thoron atoms exhibit similar shape with a linear trend plus an exponential trend on the left side of the 220Rn peak, depending from the distance between source and detector; (ii) the corresponding 220Rn detection efficiency values are compatible considering the uncertainties. An investigation was conducted to study the shape of the 220Rn spectra vs the different volume of chambers, through Monte Carlo simulations. The results show: (i) the linear part of the spectra shape goes to reduce with the increasing of the height of the chamber; (ii) the 220Rn detection efficiency decreases with the increasing of the height of the chamber.

6.
Appl Radiat Isot ; 163: 109239, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32561065

ABSTRACT

This paper reports the analysis of soil 222Rn data recorded over 7-years in the volcanic caldera of Campi Flegrei (Naples-Italy). The relationship between Radon activity concentration and several geophysical, geochemical and meteorological parameters, influencing the gas emissions, is estimated by the Artificial Neural Network (ANN) method. The analysis goals are: the estimation (replication) of the Radon time series from influencing parameters, the forecasting of an unknown part of it, and the search for anomalies. Results prove: (i) the effectiveness of the ANN method; (ii) Radon follow the periods of agitation of the caldera, demonstrated by the comparison with previous works using different methods.

7.
Sci Rep ; 10(1): 9551, 2020 06 12.
Article in English | MEDLINE | ID: mdl-32533027

ABSTRACT

This is a seven-year study (1/7/2011-31/12/2017) of radon monitoring at two sites of Campi Flegrei caldera (Neaples, Southern Italy) that in the last 70 years experienced repeated phases of volcanic unrest. The sites are equipped with devices for radon detection, based on the spectrometry analysis of the α-particles of radon daughters. A hybrid method, as combination of three known methods, is applied for the identification of residuals (anomalies) and trends of the time series of Radon. The results are compared with the following indicators of current caldera unrest: the tremor caused by the major fumarolic vent registered by a seismic station; the cumulative of background seismicity; the maximum vertical deformation acquired by GPS networks during the current phase of uplift; the temperature-pressure of the hydrothermal system estimated based on gas geo-indicators. The comparisons show strong correlation among independent signals and suggest that the extension of the area affected by current Campi Flegrei crisis is larger than the area of seismicity and of intense hydrothermal activity from which the radon stations are 1-4 km away. These results represent an absolute novelty in the study of a such calderic area and mark a significant step forward in the use and interpretation of the radon signal.

8.
Appl Radiat Isot ; 160: 109140, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32351231

ABSTRACT

The present work concerns a detailed analysis of Radon time series to differentiate endogenous from exogenous phenomena which provide anomalous signals. Two-year data from two sites in Czech Republic and in Italy are analyzed in order to contribute to the prevention of natural hazards. A new hybrid forecasting method is implemented and tuned for the identification of Radon anomalies in the time series. It is based on the combination of Multiple Linear Regressions, Empirical Mode Decomposition and Support Vector Regression methods that decompose the signal and analyze the components to distinguish the variations due to Radon originated in depths from those due to environmental parameters. The possible correlations with fumarolic tremors in the Italian site and the faults microdisplacements in the Czech site have been studied, as well as with the earthquakes that have influence on two studied areas. Results show that: (i) the used method is very effective considering the calculated statistical uncertainties; (ii) the outer temperature is the main influencing Radon driving force; (iii) the extracted Radon anomalies due to endogenous phenomena are well correlated with fault displacements, fumarolic tremors, and with earthquakes under a characteristic delay time for each area; (iv) significant correlations among earthquake magnitude and depth with fault displacement and fumarolic tremor are found.

9.
J Helminthol ; 93(5): 616-628, 2019 Sep.
Article in English | MEDLINE | ID: mdl-30231945

ABSTRACT

Despite the advances of molecular tools, new nematode species are still described mainly based on morphological characters. Parapharyngodon and Thelandros are two genera of oxyurids with unclear related taxonomic histories. Here we use morphological characters (linear measurements and categorical variables) and genetic information (18S rRNA, 28S rRNA and COI partial gene sequences) to confirm the relationships between representatives of these two genera and to determine whether they can be discriminated morphologically. Genetic results confirm the existence of two main clades, mostly congruent with Parapharyngodon and Thelandros genera but with several discordances. Thelandros is polyphyletic, with two of the species analysed (T. filiformis and T. tinerfensis) being part of the Thelandros clade, but with a third one (T. galloti) falling within the Parapharyngodon clade. Regarding the Parapharyngodon clade, P. cubensis, P. scleratus and Parapharyngodon sp. from Mexico form congruent lineages, while most P. echinatus samples cluster in another group, with one exception. Interestingly, P. micipsae samples are scattered across the Parapharyngodon clade, suggesting that they were misidentified or rather represent alternative morphotypes of other species. Morphological analysis identified the length of the tail, number of caudal papillae, position of the nerve ring, presence of caudal alae and length of the lateral alae as reliable characters to distinguish between Parapharyngodon and Thelandros genetic clades. Our study highlights the current taxonomic inconsistency in these groups, mainly derived from the exclusive use of morphological data. As such, we advocate for the routine implementation of molecular data in nematode taxonomic studies.


Subject(s)
Oxyuroidea/classification , Phylogeny , Animals , DNA, Helminth , Female , Lizards/parasitology , Male , Mexico , Oxyuriasis/parasitology , Oxyuroidea/anatomy & histology , RNA, Ribosomal, 18S/genetics , RNA, Ribosomal, 28S/genetics , Sequence Analysis, DNA
10.
Rev Esp Quimioter ; 2018 Dec 04.
Article in Spanish | MEDLINE | ID: mdl-30512080

ABSTRACT

OBJECTIVE: Bacteremia caused by Klebsiella pneumoniae carbapenemase-producing strains (Kp-KPC) is associated with high mortality. The hypothesis of our work is that there was an increase in the levels of resistance to different antimicrobials in Kp-KPC isolated from bacteremia. METHODS: Retrospective and descriptive study in two periods: Period 1 (P1) 2010-2014 and period 2 (P2) 2015-2016. We included patients ≥18 years old with bacteremia caused by Kp-KPC in a General Hospital. We defined active drug (AD) if it was in vitro susceptible and in the case of meropenem if it had a MIC ≤ 8 mg/L in combination treatment. RESULTS: Fifty episodes of bacteremia caused by Kp-KPC were analyzed in 45 patients. (P1: 21 and P2: 29). The following variables were similar in both periods: median age (53 vs. 52 years); male sex (45 vs. 62%); site of infection: primary bacteremia (52 vs.45%), bacteremia associated with catheter (24 vs.17%), and other (24 vs. 38%). During P2 there was a significant increase in colistin resistance (28 vs. 69%) (p <0.01), an increase in MIC to meropenem ≥ 16 mg/L (74 and 97%) (p = 0.02), and decrease in tigecycline resistance (29 vs. 4%) (p = 0.02). The overall mortality was 40 in P1 and 32% in P2 (p=0.7). There was not difference in mortality when the definitive treatment was with an active antimicrobial vs. two active antimicrobials, as well as between the different antimicrobials used. CONCLUSIONS: There was a significant increase in bacteremia caused by Kp-KPC and the level of colistin resistance and MIC to meropenem. Overall mortality was high in both periods.

11.
Rev. int. med. cienc. act. fis. deporte ; 18(72): 737-752, dic. 2018. tab
Article in Spanish | IBECS | ID: ibc-180242

ABSTRACT

Se evalúa las relaciones entre el perfil sociodemográfico, la accidentabilidad y la propensión al accidente de los participantes en tres eventos deportivos: Zurich Marató de Barcelona, Cros de Muntanya Can Caralleu, y Marató Borredà-Xtrail. Una adaptación del cuestionario de propensión al accidente deportivo (PAD-22) de Latorre y Pantoja (2013) fue administrado a un total de 237 corredores. Los principales resultados muestran que: los corredores tienden a ser mayoritariamente varones, de entre 30 y 46 años, asalariados, con estudios postobligatorios, con experiencia previa en eventos de larga distancia, entrenan una media de 4 veces y un total de 7 horas a la semana; y los corredores de la maratón por asfalto tienen una sobreestimación de la Competencia Percibida y grados de Competitividad mayores a los corredores por montaña


This study evaluates relations between sociodemographic profile, accident rate and accident's propensity of three sport events participants: Zurich Marató de Barcelona, Cros de Muntanya Can Caralleu & Marató Borredà-Xtrail. The used method was an adaptation of the sports accident prone scale (PAD-22) from Latorre y Pantoja (2013), to 237 runners. The main results show that: runners tend to be mostly men, aged of 30-46 years, are salaried, have post-compulsory studies, have some experience in long distance events, train a mean of 4 times and more than 7 hours per week; and marathon asphalt runners have a overestimation of Perceived Competence and elevated degrees of Competitiveness, more than trail runners


Subject(s)
Humans , Adolescent , Young Adult , Adult , Middle Aged , Running , Accident Proneness , Athletic Injuries/epidemiology , Athletic Injuries/prevention & control , Self Efficacy , Surveys and Questionnaires , Analysis of Variance
12.
Radiat Prot Dosimetry ; 177(1-2): 202-206, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29036347

ABSTRACT

This work concerns continuous monitoring of radon and thoron specific activity in soil gas within the framework of identifying possible anomalies. It is based on the analysis of a medium-term data record obtained from soil gas in an area of geophysical interest. The RaMonA spectrometric system is also used to measure the climatic parameters and a specific analysis of the alpha spectra is performed to better determine the alpha lines intensity. Since radon emission is also influenced by meteorological parameters, it is mandatory to differentiate the changes due to the deep phenomena. Different procedures are utilized to reach the above objective: statistical analysis using the Empirical Mode Decomposition technique, the Multiple Linear Regression method and the Remote Radon Estimation by using of the thoron trend to eliminate the locally produced radon fraction. The results of such methods are compared to recognize and to highlight radon anomalies.


Subject(s)
Radiation Monitoring/methods , Radon/analysis , Soil Pollutants, Radioactive/analysis , Interrupted Time Series Analysis , Italy , Radiation Monitoring/instrumentation , Seasons , Weather
13.
J Environ Radioact ; 172: 201-206, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28390309

ABSTRACT

It has been widely shown that nuclear fallout includes substances, which accumulate in organisms such as crustaceans, fish, mushrooms and lichens, helping to evaluate the activity concentration of contaminants accumulated on a long time. In this context, radiocaesium deposited in soil following the Chernobyl accident on 26 April 1986 is known to have remained persistently available for plant uptake in many areas of Europe. Studies on the lichen Stereocaulon vesuvianum show the plant's high capacity to retain radionuclides from the substrate and the air. After the Chernobyl accident, starting from September 1986, at the Radioactivity Laboratory (LaRa) of the University of Naples Federico II, four monitoring campaigns to evaluate the activity concentration of four isotopes of the two elements caesium and ruthenium (134Cs, 137Cs, 103Ru and 106Ru) were carried out until 1999. This study allowed the effective half-life of 134Cs and 137Cs to be estimated. Twenty-eight years after the accident, in December 2014, a further sampling was carried out; only 137Cs was revealed beyond the detection limits, measuring activity concentrations ranging from 20 to 40 Bq/kg, while the other radionuclides were no longer observed due to their shorter half-life. The last sampling allowed more precise determination of the effective half-life of 137Cs (6.2 ± 0.1 year), due to the larger dataset on a large time period.


Subject(s)
Air Pollutants, Radioactive/analysis , Cesium Radioisotopes/analysis , Chernobyl Nuclear Accident , Lichens/chemistry , Radiation Monitoring , Radioactive Fallout/analysis , Radioactivity
14.
Appl Radiat Isot ; 122: 180-185, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28161651

ABSTRACT

A complete and detailed analysis of alpha spectra from the 222Rn and 220Rn progenies was performed by newly developed software. The software identifies the alpha peaks, performs appropriate fits and calculates the net area and its uncertainty, considering the entire background. The deconvolution of the overlapped peaks of 218Po and 212Bi allows us also to evaluate their minimum detectable area. The efficiency of the electrostatic detection method was recalculated and new useful considerations on the collected alpha emitters were made.

15.
J Helminthol ; 90(2): 144-51, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26821706

ABSTRACT

Populations of the lizard Darevskia rudis (Bedriaga, 1886) from northern Anatolia were examined for intestinal parasites in adult specimens. One cestode, Nematotaenia tarentolae López-Neyra, 1944 and four nematode species, Spauligodon saxicolae Sharpilo, 1962, Skrjabinelazia hoffmanni Li, 1934, Oswaldocruzia filiformis (Goeze, 1782) and Strongyloides darevskyi Sharpilo, 1976, were found. Three of these nematodes, S. saxicolae, S. hoffmanni and S. darevskyi are suggested to be part of a module in the network of Darevskia spp. and their parasites. Only one, S. darevskyi, was identified as a Darevskia spp. specialist. The very low infection and diversity parameters are indicative of the depauperate helminth communities found in this lacertid lizard, falling among the lowest within the Palaearctic saurians. Nevertheless these values are higher than those found in parthenogenetic Darevskia spp. Interpopulation variation in the intensity of S. saxicolae and N. tarentolae is attributable to local changes in ecological conditions. On the other hand, parasite abundance and richness increased in the warmer localities, while the effect of lizard sex and size on infection was negligible. The structure of these helminth communities in D. rudis are compared with those observed in other European lacertid lizards.


Subject(s)
Helminthiasis, Animal/parasitology , Helminths/classification , Intestinal Diseases, Parasitic/veterinary , Lizards/parasitology , Animals , Female , Helminthiasis/epidemiology , Helminthiasis/parasitology , Helminthiasis, Animal/epidemiology , Intestinal Diseases, Parasitic/epidemiology , Intestinal Diseases, Parasitic/parasitology , Male , Turkey/epidemiology
16.
Phys Chem Chem Phys ; 18(11): 7632-40, 2016 Mar 21.
Article in English | MEDLINE | ID: mdl-26376836

ABSTRACT

A comprehensive Raman resonance scattering study of ZnSxSe1-x (ZnSSe) solid solutions over the whole compositional range (0 ≤ x ≤ 1) has been carried out using 325 and 455 nm excitation wavelengths. The Raman scattering intensities of LO ZnS-like and ZnSe-like phonon modes, corresponding to pure S and Se vibrations, respectively, are revealed to be significantly enhanced when excited with 325 nm excitation in the case of S vibrations, and with 455 nm in the case of Se vibrations. This behavior is explained by the interaction of the excitation photons with the corresponding S or Se electronic states in the conduction band, and further confirmed by first principles simulations. These findings advance the fundamental understanding of the coupling between the electronic transitions and photons in the case of Raman resonance effects, and provide inputs for further studies of lattice dynamics, especially in the case of chalcogenide materials. Additionally, the coexistence of modes corresponding to only S vibrations and only Se vibrations in the ZnSSe alloys makes these results applicable for the compositional assessment of ZnSSe compounds.

17.
J Evol Biol ; 27(8): 1631-43, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24890975

ABSTRACT

Male dimorphism has been reported across different taxa and is usually expressed as the coexistence of a larger morph with exaggerated male traits and a smaller one with reduced traits. The evolution and maintenance of male dimorphism are still poorly understood for several of the species in which it has been observed. Here, we analyse male dimorphism in several species of reptile parasitic nematodes of the genus Spauligodon, in which a major male morph (exaggerated morph), which presents the traditional male morphological traits reported for this taxon, coexists with a minor morph with reduced morphological traits (i.e. reduced genital papillae) resembling more closely the males of the sister genus Skrjabinodon than Spauligodon major males. Because of the level of uncertainty in the results of ancestral state reconstruction, it is unclear if the existence of male dimorphism in this group represents independent instances of convergent evolution or an ancestral trait lost multiple times. Also, although the number of major males per host was positively correlated with the number of females, the same did not hold true for minor males, whose presence was not associated with any other ecological factor. Nevertheless, the existence of male dimorphism in Spauligodon nematodes is tentatively interpreted as resulting from alternative reproductive tactics, with differences in presence and number of individuals as indicators of differences in fitness, with the lower numbers of minor males per host likely maintained by negative frequency-dependent selection.


Subject(s)
Adaptation, Biological/genetics , Biological Evolution , Nematoda/anatomy & histology , Phylogeny , Reptiles/parasitology , Animals , Base Sequence , Genetic Fitness , Likelihood Functions , Male , Models, Genetic , Molecular Sequence Data , Nematoda/genetics , Selection, Genetic , Sequence Analysis, DNA , Species Specificity
18.
Radiat Prot Dosimetry ; 160(1-3): 173-6, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24723194

ABSTRACT

Controlled 222Rn+220Rn mixed atmospheres have been realised introducing calibrated sources in a stainless steel chamber. An electrostatic alpha monitor internal to the chamber has been used for an accurate discrimination of alpha peaks due to the products of the two isotopes. In the chamber, different specific activities are achieved in order to test the response of the internal reference instrument and to evaluate the possible interferences due to contemporary presence of both radon isotopes. Results show that: (i) the atmospheres are very stable, (ii) the monitor is adequate for their control because the various alpha lines are well evaluated and (iii) using Tyvek® filter, the efficiency of monitor is stable and constant vs. activity.


Subject(s)
Air Pollutants, Radioactive/analysis , Radiation Monitoring/instrumentation , Radiation Monitoring/methods , Radon Daughters/analysis , Spectrum Analysis/methods , Humans
19.
Radiat Prot Dosimetry ; 162(3): 388-93, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24327752

ABSTRACT

An original optical method for track counting and film thickness determination of etched LR115 radon detectors was developed. The method offers several advantages compared with standard techniques. In particular, it is non-destructive, very simple and rather inexpensive, since it uses a commercial scanner and a free software. The complete analysis and the calibration procedure carried out for the determination of radon specific activity are reported. A comparison with the results of spark counting defines the accuracy and the precision of the new technique.


Subject(s)
Air Pollutants, Radioactive/analysis , Image Processing, Computer-Assisted/methods , Radiation Monitoring/instrumentation , Radon/analysis , Calibration , Radiation Monitoring/methods
20.
Radiat Prot Dosimetry ; 158(4): 442-6, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24146066

ABSTRACT

In this study, the indoor radon activity concentrations have been measured in the Neapolitan catacombs using LR115 detectors. The detectors were exposed for two quarters, one in the warm season and the other in the cold. This has allowed one to evaluate the seasonal variations of concentrations, while the diurnal variations were evaluated performing continuous measurements by a Radim 5 monitor. The authors found that radon concentrations were lower in winter than in summer. Based on their values, taking into consideration the working hours in the catacombs and the equilibrium factor of 0.4, the effective dose to workers was estimated.


Subject(s)
Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Radiation Monitoring/methods , Radon/analysis , Administration, Inhalation , Confined Spaces , Humans , Italy , Radiation Dosage , Seasons
SELECTION OF CITATIONS
SEARCH DETAIL
...