This paper describes the compositional and morphological features of the crater lakes found in the volcanoes of Rincón de La Vieja, Poás, Irazú, Congo and Tenorio volcanoes (Costa Rica). As evidenced by the distribution of the water and dissolved gas chemistry along vertical profiles, the different fluid sources feeding the lakes reflect the present status of each of the volcanic systems. The chemical features of the Caliente (Poás volcano) and Rincón crater (Rincón de la Vieja volcano) lakes are mainly dependent on i) inputs of magmatic fluids from sub-lacustrine fumaroles and ii) water-rock interaction processes. Conversely, the Irazú lake is mainly affected by the presence of CO2(H2S)-rich fluids discharged from a hydrothermal system, which masked possible magmatic fluid contributions. Rainfall and organic activity are the main factors responsible for the chemical composition of Hule, Botos, Congo and Tenorio lakes. The chemical and isotopic water composition of Botos, Irazú and Hule lakes have displayed no significant variations along the vertical profiles. In contrast, Caliente lake shows a distinctive chemical stratification, mainly involving F-, Cl- and SO4 2-. The behaviour of these compounds seems to be governed by both dissolution of highly acidic species, i.e. HF, HCl and SO2 released from the magmatic environment, and microbial activity. Despite the significant increases with depth of dissolved CO2 at Caliente and Irazú lakes, the hazard for Nyos-type gas eruptions can be considered negligible, since i) the water volumes are too small and ii) the convective heat transfer limits the CO2 recharge rate. The relatively high concentrations of dissolved CO2 measured at the maximum depth of the Hule lake are likely produced by both degradation of organic material and degassing from a deep source. The sporadic episodes of fish deaths recently observed in this lake can be associated with lake overturn processes that have favoured the rise up to the lake surface of deep, oxygen-depleted waters
We report the results of a geochemical survey of fumaroles, thermal springs, and gas discharges from areas in and around the active crater lake of Pofis volcano (Costa Rica) fi'om February 1998 to February 2001. The springs are highly acidic-sulphate waters with temperatures approaching boiling point, whereas gas chemistry is characterized by typical magmatic species, such as 802, HF, HC1, H2, and CO. From February 1998 new fumarolic fields formed inside the southern part of the crater. They moved anticlockwise from the S to the NE inner walls of the crater, while those located in the southern part of the crater and close to the pyroclastic cone south of the crater lake diminished or disappeared altogether, during 1999 and 2000. This shift was also characterized by chemical variation of the maganatic gas species. In spite of the chemical changes of fumaroles, the composition of the lake changed little during this time. This fact, together with the chemical profile with depth of the lake, suggests that the lake is a very efficient condenser of magmatic fluids. An apparent chemical stratification of the lake suggests that dilution with meteoric water is not complete, due to the presence of liquid sulphur at the lake bottom and/or due to the continuous influx of new magmatic components.
Background: In the Lombardy Region, Italy, HPV vaccination is recommended and offered free of charge to 12-years-old males since 2017. The expected vaccination thresholds are still far to be reached. Methods: A cross-sectional survey to investigate parents’ attitudes towards the HPV vaccine and knowledge about HPV was administered to parents of boys aged 6 to 18 years attending a large pediatric hospital for outpatient specialistic evaluations. Two parallel multiple logistic regression analyses were conducted to estimate the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for attitude towards HPV vaccination and perceived need for more information about HPV vaccination. Results: A positive attitude towards HPV vaccination was found in 74% of interviewed parents. Knowledge of HPV, having a generally positive attitude toward vaccination, and mothers filling in the survey were positively associated with a positive attitude to the HPV vaccine. Parents’ perceived need for more information about HPV vaccination was positively associated with the child’s age, general positive attitude toward vaccination, Christian religion, and positive attitude toward HPV vaccination; knowing that HPV vaccination is free of charge significantly reduced the risk of asking for more information on HPV vaccination. Conclusions: The majority of parents of male children and adolescents in our study have a positive attitude toward HPV vaccination. Attitude toward HPV vaccination and perceived need for more information on HPV vaccination were directly related to a positive attitude toward vaccines in general. In addition, knowledge of HPV and related pathologies favors a positive attitude toward HPV vaccination. Future health programs should target an even wider diffusion of evidence-based information on vaccines in general and on the HPV vaccine in young males, to support a positive attitude toward vaccines in the general population.
Trends of several applications like down-hole drilling, commercial aviation (e.g. jet engines), heavy industrial and automotive are challenging the capabilities of capacitors and other electronic components. The growing harsh-environment conditions for these applications are: high temperature, high voltage and high current. At the capacitor component level, required features are: very high reliability under mechanical shock, rapid changes in temperature, low leakage current (high insulation resistance), small dimensions, good stability with time and humidity, and high peak withstanding voltage. Capacitors for power-conversion circuitry must maintain a low AC loss and DC leakage at high temperatures. KEMET has recently designed film capacitor series using PEN to address the needs of the above mentioned circuits, in particular regarding the working temperature, voltage and current. This paper will cover technological advances in film capacitor technology to address harsh environment conditions needs, providing test results on temperature, voltage and thermal shock acceleration factor.
Acanthosis nigricans (AN) is associated with obesity and type 2 diabetes, where insulin resistance (IR) is considered a predisposing factor. IR can also affect patients with type 1 diabetes (T1D). We evaluated the prevalence of AN in patients with T1D compared to subjects with obesity in order to define the interplay between IR and excess weight. We considered 138 pediatric patients who presented with T1D and 162 with obesity. As controls, 100 healthy normal-weight subjects were included. A physical examination with the detection of AN and biochemical assessments was performed. IR was calculated by using the homeostasis model assessment for IR in patients with obesity and the estimated glucose disposal rate in T1D. The AN prevalence was higher in T1D and obese subjects compared with controls in whom AN was not detected (p = 0.02 and p < 0.001, respectively). A greater number of AN cases were observed in subjects with obesity compared with T1D (p < 0.001). Patients with AN were older than subjects without AN (p = 0.005), and they had higher body mass index (BMI) values, waist circumference (WC), fasting triglycerides and blood pressure (all p < 0.001). Thirty-five patients with AN exhibited IR with an association between AN presence and IR in patients with obesity (p < 0.001). In T1D, there was an association between AN and being overweight/obese (p = 0.02), independently of IR. AN is a dermatological condition associated with obesity. In T1D, the presence of AN was significantly associated with overweight status or obesity but not IR. The presence of AN in the absence of IR supports the interplay role between impaired insulin signaling, IR and excess weight in the pathogenic mechanism.
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