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

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 & 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 & 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

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

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

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

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

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

Physical performance in high school students: effect of chronotype

Morningness-Eveningness (M-E) is an individual characteristic, defined as chronotype. People are typically categorized in 3 different chronotypes: Morning, Evening and Neither types (M, E and N-types), which differ in the circadian rhythm of many 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. The chronotype is influenced by both individual and environmental factors and gradually changes during human development. Many studies have demonstrated a trend beginning with a tendency toward morningness in children that gradually evolves into a shift toward eveningness. Approximately at the age of 20 years, this shift reaches its maximum and starts to decline, leading to a growing tendency toward morningness from midadulthood on. This more pronounced eveningness has been found to negatively affect adolescents’ sleep and daytime functioning; even physical performance of adolescents can vary throughout the day because sleep pressure increases, the input from the circadian timing system is optimal or non-optimal to perform the task or both of them. In this study participated 216 students, 124 males and 92 females, attending the first two high school classes (mean age 14-15 years). For the assessment of chronotype, all students compiled the Morningness-Eveningness Questionaire (MEQ), validated by Horne and Ostberg in 1976. For all subjects we collected anthropometric data (weight, height, BMI). All the subjects were categorized as M (n=22), N (n=165), and E-types (n=29). To assess the relationship between chronotype and physical performance, from the sample we recruited 51 subjects, 22 M-type (14 males and 8 females) and 29 E-types (18 males and 11 females), who carried out three Eurofit tests (SHR, Shuttle Run; SBJ, Standing Broad Jump; Cooper endurance test). Preliminary results, although showing some differences in physical performance between E and M chronotype, have not detected statistically significant differences between the two groups

Escalating CO2 degassing at the Pisciarelli fumarolic system, and implications for the ongoing Campi Flegrei unrest

This short communication aims at providing an updated report on degassing activity and ground deformation variations observed during the ongoing (2012–2019) Campi Flegrei caldera unrest, with a particular focus on Pisciarelli, currently its most active fumarolic field. We show that the CO2 flux from the main Pisciarelli fumarolic vent (referred as “Soffione”) has increased by a factor > 3 since 2012, reaching in 2018–2019 levels (>600 tons/day) that are comparable to those typical of a medium-sized erupting arc volcano. A substantial widening of the degassing vents and bubbling pools, and a further increase in CO2 concentrations in ambient air (up to 6000 ppm), have also been detected since mid-2018. We interpret this escalating CO2 degassing activity using a multidisciplinary dataset that includes thermodynamically estimated pressures for the source hydrothermal system, seismic and ground deformation data. From this analysis, we show that degassing, deformation and seismicity have all reached in 2018–2019 levels never observed since the onset of the unrest in 2005, with an overall uplift of ~57 cm and ~448 seismic events in the last year. The calculated pressure of the Campi Flegrei hydrothermal system has reached ~44 bar and is rapidly increasing. Our results raise concern on the possible evolution of the Campi Flegrei unrest and reinforce the need for careful monitoring of the degassing activity at Pisciarelli, hopefully with the deployment of additional permanent gas monitoring units

The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka

This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe

Self-piercing riveting-a review

© The Author(s) 2017. This article is published with open access at Springerlink.com.Self-piercing riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR is currently the main joining method for aluminium and mixed-material lightweight automotive structures. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requirement of joining lightweight materials, such as aluminium alloy structures, aluminium-steel structures and other mixed-material structures, from the automotive industry. Compared with other conventional joining methods, SPR has many advantages including no pre-drilled holes required, no fume, no spark and low noise, no surface treatment required, ability to join multi-layer materials and mixed materials and ability to produce joints with high static and fatigue strengths. In this paper, research investigations that have been conducted on self-piercing riveting will be extensively reviewed. The current state and development of SPR process is reviewed and the influence of the key process parameters on joint quality is discussed. The mechanical properties of SPR joints, the corrosion behaviour of SPR joints, the distortion of SPR joints and the simulation of SPR process and joint performance are reviewed. Developing reliable simulation methods for SPR process and joint performance to reduce the need of physical testing has been identified as one of the main challenges.Peer reviewe

A design of experiment approach as applied to the analysis of diffuser-augmented wind turbines

Since the 1930s ducted-wind-turbines have received considerable attention due to the possibility of obtaining a significant increase in the extracted power compared to an open turbine with the same rotor swept area. The incomplete knowledge of the flow phenomena occurring in these devices and the large design-space to be explored generally hampers the development of an effective and robust design-procedure. This work investigates the performance of ducted wind turbines through a fully automated analysis procedure based on a Computational-Fluid-Dynamics-Actuator-Disk approach. The method duly takes into account the effects of the design parameters, the rotor-duct coupling, the wake rotation and expansion, and the spanwise variability of the rotor load. A Design-of-Experiment analysis is carried out to quantify the impact of the change of all geometric parameters and their mutual interactions. The latter explicitly account for the simultaneous variation of all design parameters. As such, it is a powerful pre-design tool that allows to reduce and confine the design space. It is found that the chord and stagger angle of the duct contribute more than 85% to the improvements of the turbine performance, while the effects of the thickness are negligible. Finally, the sensitiveness of the performance to the variation of the operating conditions is also analysed revealing that the optimal configuration is also the most robust