196 research outputs found

    Groundwater flow process in the active volcanic system of Ischia Island (Italy)

    Get PDF
    The volcanic system of Ischia is characterized by an intense hydrothermal activity, documented since the early 16th century by the study of Iasolino (1588), which represents the first systematic analysis of the thermal springs of the island for therapeutic purposes. Later studies partially contributed to the enhancement of knowledge on the volcanic, hydrogeological and hydrothermal features of the island, highlighting the strong interaction between hydrothermal flowpaths and volcano- tectonic processes. The reconstruction of the interplay between hydrothermal and magmatic system becomes, therefore, a fundamental element for territorial planning, not only in terms of management of the huge water and geothermal resource, but also in a perspective of prevention and mitigation of volcanic risk. Thermal springs, fumaroles and mud deposits give beginning clues about deep hydrothermal conditions. Till now at Ischia, the local geochemical characterization of fluids and groundwater has been used for the definition of the origin and structure of the hydrothermal system as a whole, as the hydrogeological information is incomplete. However, volcanic hydrothermal systems, such as that characterizes the island of Ischia, are particularly difficult to analyze and outline, as the groundwater resources are the result of a complex and dynamic mixing among meteoric water, sea water and deep fluids. In such cases, the need for an interdisciplinary approach is evident, involving knowledge and research methods ranging from geology to volcanology, geophysics, geochemistry and hydrogeology. With particular reference to the functional and structural representation of the geothermal system of the Ischia island and the resulting correlations with the volcano-tectonic processes, the examination of previous information highlights the need to update and improve the knowledge on groundwater hydrodynamics and mineralization processes. Therefore, the present study aims at a strongly interdisciplinary action that, starting from the design and implementation of a database on the existing geological/volcanological and hydrogeological information, will contribute to highlight the critical issues, define an operating scheme of the hydro-geo-thermal system of the island of Ischia, and upgrade its hydrogeological, geochemical and volcanic monitoring system. The preliminary results improved the definition of the hydrogeological complexes and advanced knowledge of the groundwater flow conditions

    Groundwater flow characterization and reconstruction of the hydrothermal system of Ischia as a tool for volcanic risk mitigation

    Get PDF
    The volcanic system of Ischia is characterized by an intense hydrothermal activity, documented since the early 16th century by the study of Iasolino [1588], which represents the first systematic analysis of the thermal springs of the island for therapeutic purposes. Later studies partially contributed to the enhancement of knowledge on the volcanic, hydrogeological and hydrothermal features of the island, highlighting the strong interaction between hydrothermal flowpaths and volcanotectonic processes. The reconstruction of the hydrothermal system becomes, therefore, a fundamental element for territorial planning, not only in terms of management of the huge water and geothermal resource, but also and above all in a perspective of prevention and mitigation of volcanic risk. Thermal springs, fumaroles and clay deposits due to the hydrothermal alteration of volcanic products testifies for the existence of an active deep hydrothermal system. However at Ischia the geochemical characterization of fluids and groundwater, performed through sampling and analysis of a discrete number of scattered springs, wells and fumaroles, has been used for the definition of the origin and structure of hydrothermal systems as a whole, as the hydrogeological information is incomplete. Moreover, volcanic hydrothermal systems, such as that characterizes the island of Ischia, are particularly difficult to analyze and outline, as the groundwater resources are the result of an articulated and dynamic interaction among meteoric water, sea water and fluids of deep origin. In such cases, the need for an interdisciplinary approach is evident, involving knowledge and research methods ranging from geology to volcanology, geophysics, geochemistry, mineralogy and hydrogeology. With particular reference to the functional and structural representation of the geothermal system of the island of Ischia and the resulting correlations with the volcanotectonic processes, the examination of previous information highlights the need to update and improve the knowledge on groundwater hydrodynamics and mineralization processes. Therefore, the present work represents a strong interdisciplinary action that, starting from the design and implementation of a database on the existing geological/volcanological and hydrogeological information, contributes to highlight the critical issues, define an operating scheme of the hydrogeothermal system of the island of Ischia, and upgrade its hydrogeological, geochemical and volcanic monitoring system, in order to contribute to the mitigation of volcanic and related risks. The knowledge of groundwater dynamics and pathways, in fact, is of fundamental importance for understanding the water/magma interaction processes in case of realimentation of the shallow magmatic system, and the assessment of the possibility of phreatic explosions occurrence. Moreover, the knowledge of the thermal fluids’ circulation and the related rock alteration processes is of paramount importance in the definition of the mechanic characteristics of rock masses and their proneness to failure

    Circadian rhythm of activity levels: influence of chronotype.

    Get PDF
    Aim: The aim of this study is to investigate, by an actigraph monitoring, the differences in the circadian rhythm of activity level in relation to the chronotype for the sake of studying its influence on physical performance. Morning-type (M-type), Evening-type (E-types) and Neither-type (N-type) are the classified chronotypes; several studies showed the differences between M-types and E-types in the circadian rhythm of different physiological variables: M-types use to wake up and go to bed early and to have their best performances in the first part of the day, otherwise E-types go to bed and wake up late and they have the peak performances in the evening (Vitale et al., 2013). Method: The morningness\u2013eveningness questionnaire (MEQ) was administered to 502 college students to determine their chronotypes. Fifty subjects (16 M-types, 15 N-types and 19 E-types) were recruited to undergo a 7-days monitoring period with an actigraph (Actiwacth actometers, CNT, Cambridge, UK) to evaluate their sleep parameters and the circadian rhythm of their activity levels. To evaluate the circadian rhythmicity of activity levels we used the single cosinor method (Halberg et al., 1977) and we define three parameters characteristic of each statistically significant rhythm: M, MESOR (Midline Estimating Statistic Of Rhythm); A, Amplitude; \u3d5, acrophase. The population circadian characteristics were determined and then compared using the Hotelling test. Results: Rhythmometric analysis, with the single cosinor method, on the activity data collected by the actigraph revealed a statistically significant circadian rhythm (p<0.001) for all the 50 subjects. The population mean cosinors were calculated grouping the different chronotypes: M-types, E-types and N-types (p<0.001). No statistical differences about MESOR were showed for all group combinations (p>0.05) but a significant difference (p<0.05) was observed if considering the Amplitude-Acrophase test for all groups combinations, in particular M-types had an early acrophase of the circadian rhythm of the activity levels, at 14.37, while E-types showed an acrophase with more than 2 hours late, at 17.04 (p<0.001); the group of Ntypes showed an intermediate acrophase, at 15.45, between morning-types and evening-types. Conclusion: We can assume that there is a clear difference between \u201clarks\u201d and \u201cowls\u201d and this results are in line with other studies that showed the biological differences among chronotypes. We can conclude that M-types are more active in the early afternoon and that E-types have the peak of their activity in the late afternoon. Further studies are needed to better understand if and how the chronotype influence a physical performance. References 1. Halberg F., Carandente F., Cornelissen G., Katinas G.S. (1977). Glossary of chronobiology. Chronobiologia 4 (Suppl. 1):1-189. 2. Vitale J.A., Calogiuri G., Weydahl A. (2013). Percept. Mot. Skills. 116(3):1020-1028

    Actigraphy-based sleep behavior and high intensity interval training (HIIT): the chronotype effect

    Get PDF
    INTRODUCTION Physical activity can improve sleep quality through numerous mechanisms by creating a state of general well-being. It is difficult to understand exactly how exercise impacts on sleep and vice versa: different volumes, intensities and types of physical activity could have some positive or negative effects on sleep and sleep loss or restriction could influence both physical and cognitive performances (Souissi et al., 2008). It is largely demonstrated that M-types go to bed and wake up earlier than E-types and that E-types use to sleep less during the working days but more during the weekends (Vitale et al., 2015). The aim of this study was to evaluate the effects of sleep behavior following the 4x4 min of high-intensity interval training (HIIT) proposed by Helgerud (Helgerud et al., 2001), performed by subjects at 08:00 pm, also taking into account the influence of the chronotype variable. METHODS 15 male subjects (mean age: 20 \ub1 2), soccer players, enrolled in the School of Exercise Science, University of Milan, at baseline filled in the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) for the assessment of chronotype (Horne &amp; Ostberg, 1976). An actigraph monitoring was performed for one week to detect nocturnal sleep PRE-HIIT, and POST-HIIT taking into account the following actigraphy-based sleep parameters: Actual Sleep % (AS), Sleep Efficiency % (SE), Immobile Time % (IT) and Movement Fragmentation Index % (MFI). We compared sleep behavior from PRE to POST conditions between chronotypes. RESULTS 9 soccer players resulted E-types while 6 resulted M-types. E-types and M-types did not present any significant differences for sleep behavior from PRE to POST condition, nevertheless M-types showed a trend to worsen their sleep in the POST condition with a decrease in SE and an increase in MFI. DISCUSSION Our results suggest that HIIT performed at 08:00 pm did not affect the sleep behavior in E-types while M-types, who are more active in the first part of the day, showed a strong trend to worse their sleep quality therefore it seems that they are disadvantaged when performing a training task in the evening. REFERENCES \u2022 Helgerud J et al., Aerobic endurance training improves soccer performance, Med Sci Sports Exerc.2001 Nov; 33(11):1925-31 \u2022 Horne JA &amp; Ostberg O, A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms, International Journal of Chronobiology 1976; 4(2):97-110 \u2022 Souissi N et al., Effect of time of day and partial sleep deprivation on short-term, high-power output, Chronobiol. Int.2008; 25(6):1062-76 \u2022 Vitale JA, et al., Chronotype influences activity circadian rhythm and sleep: differences in sleep quality between weekdays and weekend, Chronobiol. Int.2015 Apr; 32(3):405-1

    Anthropometric indices of adiposity and fasting glucose metabolism in breast cancer survivors: effects of aerobic physical activity

    Get PDF
    Adiposity and hypersinsulinemia are factors involved in cancer mortality including BC (1). Physical activity (PA) has the potential to counterbalance these risk factors. In fact, PA has been shown to produce beneficial effects on adiposity and glucose metabolism (2). We thus designed a randomized controlled trial to test the effect of an aerobic PA program on anthropometric indices of adiposity and fasting glucose metabolism in BC women included in a dietary intervention trial for prevention of BC recurrences. 42 BC women, aged 35-70 years, were randomized into an intervention (IG=19) and control group (CG=23). The IG had to participate in a 3-month active PA program that included two sessions of one-hour brisk walking per week. At baseline and after 3-month, all women were requested to undergo an anthropometric visit and to collect a blood sample for determination of fasting insulin and glucose levels. At the end of the 3-month PA a significant reduction in waist circumference (p&lt;0.05) and percentage fat mass (p&lt;0.01) were observed in IG, but not in CG. In addition, only IG increased significantly their Metabolic Equivalent of Task (METs) (p&lt;0.05). Although fasting glucose and insulin levels don\u2019t show any significant change in either group, it is nevertheless encouraging that the two groups displayed an opposite trend as far as the changes in fasting insulin were concerned: fasting insulin shows a mean reduction (-0.9 \uf06dU//ml) in the IG group and a mean increment in the CG (+0.7 \uf06dU/ml). The results suggest that a standardized PA program in BC survivors reduces anthropometric indices of adiposity and may prove useful in preventing the development of hyperinsulinemic levels. References 1. Mann et al. (2014) Changes in insulin sensitivity in response to different modalities of exercise: a review of the evidence. Diabetes Metab Res Rev. 30(4): 257-268. 2. Pisani (2008) Hyper-insulinaemia and cancer, meta-analyses of epidemiological studies. Arch Physiol Biochem 114(1): 63\u201370

    Morning or evening training : effect on heart rate circadian rhythm

    Get PDF
    Twenty male endurance athletes (aged 20\u201325 years) carried out 2-hour daily training sessions, every day from Monday to Friday, for an overall period of 4 weeks. Four different weekly training time table (09.00-11.00; 11.00-13.00; 16.00-18.00; 18.00-20.00 hours) were followed, changing the time slot each week. Each athlete trained, in turn, in each period. The fifth day of each week, heart rate was monitored for 24-28 hours. Statistical analysis employed the single and mean cosinor methods. The heart rate (HR) circadian rhythm was statistically significant (p<0.05) in all 4 training session time. The HR acrophase is progressively postponed during the afternoon: the heart rate acrophase for training done between 18.00 and 20.00 is delayed by approximately 3 hours compared to that of the training done between 09.00 and 11.00. Training done at different daily times synchronizes the HR circadian rhythm. Temporal programming of physical activity is a tool capable of modifying the temporal structure of physiological variables. This approach can be of great interest for coaches who plan training programs and it may benefit athletes when time zone adjustment is an issue, such as transferring to a different continent for a competitive event

    Helix straminea Briganti, 1825 in Italy (Gastropoda: Pulmonata): taxonomic history, morphology, biology, distribution and phylogeny

    Get PDF
    The land snail taxon Helix straminea Briganti, 1825 has been reintroduced as a valid species in 2014. We provide here a comprehensive account of its taxonomy, distribution, anatomy, phylogeny and karyology in Italy. An overview of the historical views on the validity of the species is presented and faunistic data are reviewed and implemented with new records from Campania and Basilicata. A lectotype is fixed for H. straminea from the syntypes stored in the Muséum d’Histoire Naturelle of Genève, as well as for three other taxa (Helix straminiformis Bourguignat, 1876, Helix yleobia Bourguignat, 1883 and Helix straminea ssp. elongata Bourguignat, 1860). Genital system, radula and karyotype are described for the first time. Molecular analysis of two mitochondrial genes combining GenBank data and the new sequences presented in this paper showed no differentiation between the northern and southern Italian populations. The conservation status of the species and its possible threats are discussed

    Actigraphy-based activity levels and anthropometric measurements in breast cancer survivors: effects of aerobic physical activity

    Get PDF
    The research investments for the identification of modifiable factors associated with BC recurrences is increasing. Adiposity and other anthropometric indices have been acknowledged as factors involved in BC recurrences and mortality (1). Physical activity (PA) has the potential to counterbalance all of these risk factors (2). We designed a randomized controlled trial to test the effect of an aerobic PA program on anthropometric indices of adiposity and circadian rhythm activity level, evaluated by actigraphy, in BC women included in a dietary intervention trial for prevention of BC recurrences. 40 BC women, aged 35-70 years, were randomized into an intervention (IG=19) and a control group (CG=21). The IG participated in a 3-month active PA program that included two sessions of one-hour brisk walking per week. At baseline and after 3 months, both IG and CG were evaluated for the following parameters: height, weight, BMI, waist circumferences, % fat mass, % lean mass; energy expenditure and motion level (Total Energy Expenditure-TEE, number of steps, PA level, Metabolic Equivalents-METs) using a SenseWear Pro 3 Armband; and activity level circadian rhythm using the Actigraph Actiwatch. At the end of the 3-month PA program, IG showed a significant reduction in fat mass % while CG improved weight and BMI. The population mean cosinor applied to IG and CG at PRE and POST revealed the presence of a significant circadian rhythm in two groups (
    • …
    corecore