69 research outputs found
Geochemistry of groundwater from Graciosa Island (Azores): A contribution to the hydrothermal system conceptual model
Graciosa island is located in the Azores Archipelago,
along the so-called Terceira Rift, a major tectonic structure
that makes the NE boundary of the Azores Plateau. In general
terms, it includes a basaltic plataform on the NW and a silicic
poligenetic volcano with caldera on the SE, the Graciosa
Caldera Volcano. This volcano has produced significant
tephra falls, pyroclastic flows, lahars, and lava flows, both of
basaltic s.l. and trachitic s.l. composition.
The hydrothermal system shows fumarolic emissions
inside the volcano caldera and thermal springs located along
the shoreline. This system is exploitated in a thermal building
through shallow and deep (110 m) boreholes, near the coast.
In Graciosa two types of Na-Cl groundwater systems can
be identified: 1) a cold one emerging at springs and exploited
by wells for public water supply, and 2) a hydrothermal
system with temperatures around 40-44 °C. The cold
groundwaters have pH higher than 7 and different degree of
mineralization, according to the proximity to the sea. The
thermal waters show mixing with seawater, pH varying
between 6.20 and 6.94, 166 mg/L of SiO2, and significant
concentration of metals, such as Mn, Fe, Co, Ni, Cu and Zn.
The thermal water mineralization varies strongly, showing EC
from 8.87 mS/cm (shallow water) to 47.4 mS/cm (deeper
water). The higher mineralized water is rich in CO2(g), with
2130 mg/L of total dissolved CO2. Geothermometers
application reveals aquifer temperature around 167 °C and
immature/mixed waters, not reaching complete equilibrium
with reservoir rock.
The geochemistry of the thermal waters indicates the
occurrence of seawater/host rock interaction processes at high
temperature and slightly acid conditions, favored by CO2(g)
input, and a different degrees of mixing with cold and shallow
groundwaters
Helium isotopes distribution in NW Iberian peninsula: evidences of a local neotectonic activity
In this work we report new data on He abundances and isotope ratios
(3He/4He) from gas associated to some thermal and CO2-rich mineral waters in
N-Portugal. Collected gas samples are mainly CO2-dominant except two sites
where gas is N2-rich. All the sampling sites are characterized by exceptionally
high helium contents with 3He/4He ratios, corrected for air contamination,
varying considerably from 0.09 to 2.68 Ra. In all sites, the 3He/4He ratios are
higher than that typical for stable continental areas thus indicating a variable but
not-negligible (up to 30%) contribution of mantle-derived primordial He. In all
the CO2-rich waters, CO2/3He ratios and 13CCO2 are comparable with mantle
values, thus suggesting a magmatic origin also for CO2. On the contrary, in the
N2-rich waters He is mainly radiogenic, and CO2 is organic in origin. Since no
recent volcanic activity is observed in NW Iberia, high 3He/4He values could be
due, at least, to three processes:
a) releasing of gas from the local upper mantle through deep extensional fault
systems; b) releasing of magmatic volatiles from crustal reservoir(s) formed
during past volcanic activity; c) degassing of a subsurface emplaced magma body.
Mantle He flux in N-Portugal has been estimated to be up to 3 orders of
magnitude higher than that typical for stable continental areas, thus suggesting,
in this area, the presence of a tensional tectonic regime. This implies that mantle
gases could migrate upward probably through inherited tectonic structures
reactivated by neotectonic activity. The third possible scenario seems to be less
plausible since seismic surveys carried out in NW Iberian did not find any
significant evidence of mantle intrusion in the crust. The observed spatial
variability in mantle-derived contribution could reflect the geometry of the
granitic plutons in this area, thus supporting the hypotheses of an upper mantle
degassing. Alternatively, it could be the result of a lateral migration of magmatic
volatiles stored in a crustal reservoir
Contaminação de água subterrânea por substâncias de limpeza da neve em estradas: o caso do sector de Nave de Santo António – Covão do Curral (Serra da Estrela, Centro de Portugal)
Num momento em que a gestão sustentável dos recursos hídricos se assume como uma das maiores preocupações à escala mundial, as regiões de montanha têm vindo a ser reconhecidas como Reservatórios de Água (PROGRAMA UNESCO IHP-VI). O facto de muitas destas áreas se localizarem a altitudes elevadas e serem recortadas por rodovias obriga a frequentes operações de limpeza de neve, especialmente no inverno. A aplicação de substâncias químicas como cloreto de sódio e cloreto de cálcio na promoção da fusão do gelo e na limpeza da neve das estradas constitui um problema ambiental de elevado interesse científico, social e económico. Devido às suas características geológicas, geomorfológicas e climáticas, a Serra da Estrela é considerada estratégica para a gestão da água em Portugal. No presente trabalho apresentam-se alguns resultados hidrogeoquímicos que indicam que a utilização dos referidos sais na limpeza do gelo e da neve das rodovias contribui para a contaminação dos recursos hídricos
Obesity and asthma: an association modified by age
[Abstract] Background. Some studies indicate some causal relationship between obesity and asthma, while others show inconsistent results. Our objective was to evaluate the prevalence of asthma according to obesity in children.
Methods. A cross-sectional study, following the ISAAC study methodology, was conducted on two randomly selected groups consisting of 6–7 year-old children (n = 7485) and 13–14 year-old adolescents (n = 8496).
The asthma symptoms and potential risk factors were determined from the questionnaire. Overweight and obesity were defined based on the body mass index.
Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals.
Results. Obesity was associated with an increase in wheezing ever (OR: 1.35) and exercise-induced asthma (OR: 1.62) in the 6–7 year-old group. No significant relationship was observed in the adolescent population.
Conclusion. Obesity was associated with a higher prevalence of asthma in young children, but not in adolescents
Exposure to paracetamol and asthma symptoms
Multicenter study[Abstract] Background: Paracetamol is one of the factors that have been associated with the observed increase in asthma prevalence in the last few years. The influence of environmental or genetic factors in this disease may be different in some countries than in others. The purpose of this study was to analyse the relationship between the paracetamol consumption and asthma prevalence in our community.
Methods: A cross-sectional study was conducted on more than 20,000 children and adolescents in Galicia, Spain. The International Study of Asthma and Allergies in Childhood methodology was used to collect the information on asthma symptoms in children, paracetamol consumption, body mass index (BMI), pets in the home, education level of the mother and parental asthma and smoking habits. The influence of paracetamol consumption on the prevalence of asthma symptoms was calculated using logistic regression, adjusted for the other parameters included in the study.
Results: After adjusting for gender, BMI, having a cat or dog, maternal education, parental asthma and smoking, in 6- to 7-year-old children, the consumption of paracetamol during the first year of life is associated with asthma [odds ratio (OR) 2.04 (1.79-2.31) for wheezing at some time]. Paracetamol consumption in the previous year leads to a significant increase in the probability of wheezing at some time [OR 3.32 (2.51-4.41)] in young children and adolescents [OR 2.12 (1.68-2.67)].
Conclusions: Paracetamol consumption is associated with a significant increase in asthma symptoms. The effect is greater the more often the drug is taken
Impact of parental smoking on childhood asthma
[Abstract] Objective: To evaluate the exposure to environmental tobacco smoke (ETS) of the childhood population in this community and its relationship with asthma symptoms.
Methods: A cross-sectional study was conducted using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire on children and adolescents in this community. The symptoms "wheezing ever", "current asthma", "severe asthma", and "exercise-induced asthma" were defined by this questionnaire. Parental smoking was classified into four mutually exclusive categories: 1) no parent smokes; 2) only the mother smokes; 3) only the father smokes; and 4) both parents smoke. The odds ratio of the prevalence of asthma symptoms according to ETS exposure was calculated using logistic regression.
Results: A total of 10,314 children and 10,453 adolescents were included. Over 51% of the children and adolescents were exposed to ETS at home. ETS is associated with a higher prevalence of asthma symptoms, particularly if the mother or both parents smoke.
Conclusion: The prevalence of ETS is still high in this community, although there has been a decreasing tendency in the last 15 years. ETS is associated with higher prevalence of asthma
KCNA5 gene is not confirmed as a systemic sclerosis-related pulmonary arterial hypertension genetic susceptibility factor
<p>Introduction: Potassium voltage-gated channel shaker-related subfamily member 5 (KCNA5) is implicated in vascular tone regulation, and its inhibition during hypoxia produces pulmonary vasoconstriction. Recently, a protective association of the KCNA5 locus with systemic sclerosis (SSc) patients with pulmonary arterial hypertension (PAH) was reported. Hence, the aim of this study was to replicate these findings in an independent multicenter Caucasian SSc cohort.</p>
<p>Methods: The 2,343 SSc cases (179 PAH positive, confirmed by right-heart catheterization) and 2,690 matched healthy controls from five European countries were included in this study. Rs10744676 single-nucleotide polymorphism (SNP) was genotyped by using a TaqMan SNP genotyping assay.</p>
<p>Results: Individual population analyses of the selected KCNA5 genetic variant did not show significant association with SSc or any of the defined subsets (for example, limited cutaneous SSc, diffuse cutaneous SSc, anti-centromere autoantibody positive and anti-topoisomerase autoantibody positive). Furthermore, pooled analyses revealed no significant evidence of association with the disease or any of the subsets, not even the PAH-positive group. The comparison of PAH-positive patients with PAH-negative patients showed no significant differences among patients.</p>
<p>Conclusions: Our data do not support an important role of KCNA5 as an SSc-susceptibility factor or as a PAH-development genetic marker for SSc patients.</p>
Retrotransposon instability dominates the acquired mutation landscape of mouse induced pluripotent stem cells.
Induced pluripotent stem cells (iPSCs) can in principle differentiate into any cell of the body, and have revolutionized biomedical research and regenerative medicine. Unlike their human counterparts, mouse iPSCs (miPSCs) are reported to silence transposable elements and prevent transposable element-mediated mutagenesis. Here we apply short-read or Oxford Nanopore Technologies long-read genome sequencing to 38 bulk miPSC lines reprogrammed from 10 parental cell types, and 18 single-cell miPSC clones. While single nucleotide variants and structural variants restricted to miPSCs are rare, we find 83 de novo transposable element insertions, including examples intronic to Brca1 and Dmd. LINE-1 retrotransposons are profoundly hypomethylated in miPSCs, beyond other transposable elements and the genome overall, and harbor alternative protein-coding gene promoters. We show that treatment with the LINE-1 inhibitor lamivudine does not hinder reprogramming and efficiently blocks endogenous retrotransposition, as detected by long-read genome sequencing. These experiments reveal the complete spectrum and potential significance of mutations acquired by miPSCs.Patricia Gerdes, SueMei Lim, AdamD. Ewing, Michael R. Larcombe, Dorothy Chan, Francisco J. Sanchez-Luque, Lucinda Walker, Alexander L. Carleton, Cini James, Anja S. Knaupp, Patricia E. Carreira, Christian M. Nefzger, Ryan Lister, Sandra R. Richardson, Jose M. Polo, Geoffrey J. Faulkne
Differential pulse voltammetric determination of diclofenac in pharmaceutical preparations and human serum
Update of EULAR recommendations for the treatment of systemic sclerosis
The aim was to update the 2009 European League against Rheumatism (EULAR) recommendations for the treatment of systemic sclerosis (SSc), with attention to new therapeutic questions. Update of the previous treatment recommendations was performed according to EULAR standard operating procedures. The task force consisted of 32 SSc clinical experts from Europe and the USA, 2 patients nominated by the pan-European patient association for SSc (Federation of European Scleroderma Associations (FESCA)), a clinical epidemiologist and 2 research fellows. All centres from the EULAR Scleroderma Trials and Research group were invited to submit and select clinical questions concerning SSc treatment using a Delphi approach. Accordingly, 46 clinical questions addressing 26 different interventions were selected for systematic literature review. The new recommendations were based on the available evidence and developed in a consensus meeting with clinical experts and patients. The procedure resulted in 16 recommendations being developed (instead of 14 in 2009) that address treatment of several SSc-related organ complications: Raynaud's phenomenon (RP), digital ulcers (DUs), pulmonary arterial hypertension (PAH), skin and lung disease, scleroderma renal crisis and gastrointestinal involvement. Compared with the 2009 recommendations, the 2016 recommendations include phosphodiesterase type 5 (PDE-5) inhibitors for the treatment of SSc-related RP and DUs, riociguat, new aspects for endothelin receptor antagonists, prostacyclin analogues and PDE-5 inhibitors for SSc-related PAH. New recommendations regarding the use of fluoxetine for SSc-related RP and haematopoietic stem cell transplantation for selected patients with rapidly progressive SSc were also added. In addition, several comments regarding other treatments addressed in clinical questions and suggestions for the SSc research agenda were formulated. These updated data-derived and consensus-derived recommendations will help rheumatologists to manage patients with SSc in an evidence-based way. These recommendations also give directions for future clinical research in SSc
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