318 research outputs found
Possible Micrometeorological Anomalies Induced by Volcanic Activity Recorded at Stromboli Island (Aeolian Archipelago, Italy)
Hourly values of atmospheric pressure and air temperature have been acquired at the top of two volcanic islands, Stromboli and
Salina in the Aeolian Archipelago (Italy), very similar in height and morphology but completely different with regard to their
volcanic activity state: the former is permanently active, whereas the latter is extinguished. During the last four years Stromboli
experienced normal activity, volcanic unrests, and an effusive eruption (August–November 2014).The comparative analysis of the
recorded data, both in the time and frequency domains, evidenced a peculiar micrometeorological regime at Stromboli, more
turbulent during unrests with respect to the quieter periods, but showing an apparent paradox during eruptions, characterized
by a lower atmospheric turbulence. These observations suggest that the studied volcanic-micrometeorological system is chaotic,
due to contemporary opposite transients generated in the atmosphere by volcanic activity changes, and that micrometeorological
conditions in volcanic areas are controlled both by exogenous processes and volcanic activity
Decoupling of ground level pressures observed in Italian volcanoes: are they driven by space weather geo-effectiveness?
Investigations on correlation drops between near-ground atmospheric
pressures measured at sea level and at higher altitudes on Italian volcanoes
have been carried out. We looked for perturbations of the atmospheric
pressure field driven by volcanic activity, but not excluding possible
external triggers for the observed anomalies. Decorrelations between atmospheric
pressures measured at Stromboli Island in stations located at
different altitudes (years 2002-10) have been analysed and compared with
data from other volcanic (Vesuvius) and non volcanic (Mt. Soro) orographic
structures. We investigated as their possible triggers volcanic, meteorological
and space weather parameters, with particular attention to
Total Solar Irradiance (TSI), Kp index and Forbush decreases. Pressure
decorrelations seems to be driven by astronomic cycles, with maxima in
summer and minima in winter. A further contribution was found, seemingly
assignable to TSI anomalies, with correlation minima occurring 12
hours after these but only during phases of high Sun activity. Moreover,
during the same phases a main periodicity of about 27 days in pressure
decorrelations was revealed by FFT analysis. This period is the same of
the Sun Carrington rotation, expressing the periodic reappearance of
sunspot groups on Sun’s surface. The strong similarity between recurrences
of sunspot number and atmospheric pressure anomalies further
supports the role of the former as a possible trigger for the latter
The Role of High School Physical Activity Experience in College Students’ Physical Activity Motivation
International Journal of Exercise Science 7(2) : 98-109, 2014. This study tested the role of past physical activity mode in predicting physical activity motivation of first year college students. Consistent with self-determination theory, perceived competence and autonomy were expected to mediate the relationships of specific types of physical activity engaged in during high school to autonomous motivation for physical activity in college. College students (N = 124; Mage= 18.42, SD = 0.51) completed an online questionnaire that assessed frequency of engagement in different modes of physical activity during their final year of high school (i.e., competitive sport, recreational sport, aerobic exercise, resistance exercise, organized activities and recreational activities) and current perceptions of competence and autonomy and autonomous motivation for physical activity in college. Path analysis results showed that feelings of competence and autonomy mediated the relationships of past engagement in competitive sport and resistance exercise to current autonomous motivation for physical activity. Competitive sport involvement positively predicted both perceived competence and autonomy, whereas resistance exercise positively predicted perceived competence. Results supported self-determination theory and suggest that creating more opportunities for students to stay involved in competitive sport and engage in resistance exercise may be important for sustaining physical activity behaviours in college
Relationship between surface temperatures and seismic activity at Vulcano, Aeolian Island (Italy)
Time-series acquired during last years by surface monitoring parameters are compared, and the results are discussed, following a theoretical approach. Surface parameters are fluid temperature, soil temperatures and seismic activity at La Fossa of Vulcano. Discussed periods are 1998 and from 2004 to 2007, when time relationship between changes of the heat flow from the ground and seismic activity, resulted worth noting. Earthquakes originating in the area of Vulcano are associated with both fracturing and degassing mechanisms. The formers are related to the activity of tectonic structures; while the latter are connected to fluid dynamics within the interior of the volcanic apparatus. In November 1998 seismic activity at La Fossa sharply increased: Five events were registered, with seismic signals of typical faulting earthquakes, triggered by mechanism of shear fracturing and focal depths ranging 1-4 km. Fumaroles temperatures, recorded by continuous monitoring system of INGV - Palermo, showed a growing trend since October to November 1998, highlighting a big increase of heat transfer during the period, and also the soil temperature, out of the fumaroles field showed a marked increase. Fumaroles temperatures heralded the increase of heat and energy flow during a pre-seismic period of about 1 month. The transient variation of surface release reflect an excited state of the system and may have many different causes, not directly related to the magma. Indeed, stress drops generated by small fracturing earthquakes, introduce a significant perturbation in the system resulting in a relevant production of mass and energy flow. Until these flows counteract every stress gradient, they support stationary state of the system. The observed time relationships only allow a qualitative discussion about cause and effects, but doesn’t allow any quantitative evaluation. Pressure transients generate anomalies (flows of matter, differential in heat flows, chemical reaction rates) whose time frame is specific, depending on many possible processes and path-ways. Fluid phases, along fumarolic conduits, reach the surface faster than the co-genetic earthquake, as the earthquake is embedded in a strain transient that broadly exceeds the time-space frame of the seismic transient (Lomnitz, 1994). On the other hand, in a volcano-tectonic context, different energy flows can either be a cause, either an effect of perturbation, depending on depth of their primary source. Thus, in some instances the strain transient related to local earthquakes produces anomalous chemical flows, while, in other instances the local seismic activity may be produced by chemical flows from the magmatic source. Following a period of lower energy release, other 3 anomalous periods were observed from November 2004, either in the seismic release and in the surface heat flow, even out from fumaroles. So far, the monitored sites resulted very sensitive to minor perturbations of the system. The comparative analysis of different time-series supplies information related to perturbations of the state variables, useful to verify conceptual framework and to better define “classical” and “new” monitoring techniques for volcanic, as well as seismic surveillance
Groundwater geochemistry of the Mt. Vesuvius area: implications for volcano surveillance and relationship with hydrological and seismic signals
Geochemical data obtained between 1998 and 2011 at the Mt. Vesuvius
aquifer are discussed, focusing on the effects of both the hydrological
regime and the temporal pattern of local seismicity. Water samples were
collected in a permanent network of wells and springs located in the areas
that are mostly affected by the ascent of magmatic volatiles, and their
chemical composition and dissolved gas content were analyzed. As well as
the geochemical parameters that describe the behavior of groundwater at
Mt. Vesuvius, we discuss the temporal distribution of volcano-tectonic
earthquakes. The seismological data set was collected by the stations
forming the permanent and mobile network of the Istituto Nazionale
di Geofisica e Vulcanologia - Osservatorio Vesuviano (INGV-OV). Our
analysis of seismic data collected during 1998-2011 identified statistically
significant variations in the seismicity rate, marked by phases of decreasing
activity from October 1999 to May 2001 and increasing activity
from August 2004 to mid-2006. The water chemistry shows peculiar patterns,
characterized by a changeable input of CO2-rich and saline water,
which must be related to either a changing stress field or an increased
input of CO2-rich vapor. The water chemistry data from 1999 to 2003 account
for both higher fluid pressure (which induced the seismic crisis of
1999 that peaked with a 3.6-magnitude earthquake in October 1999) and
the increased input of CO2-rich fluids. The highest emission of CO2 from
the crater fumaroles and the corresponding increase in dissolved carbon
in groundwater characterize the phase of low seismicity. The termination
of the phase of intense deep degassing is associated with a change in
water chemistry and a peculiar seismic event that was recorded in July
2003. All these seismic and geochemical patterns are interpreted according
to temporal variations in the regional and local stress field
Seismic activity and thermal regime of low temperature fumaroles at Mt. Vesuvius in 2004-2011: distinguishing among seismic, volcanic and hydrological signals
Seismological, soil temperature and hydrological data from Mt. Vesuvius are collected to characterize the present-day activity of the volcanic/hydrothermal system and to detect possible unrest-related phenomena. We present patterns of seismicity and soil temperature in the crater area during the period February 2004-December 2011. The temporal distribution of number and depth of Volcano-Tectonic earthquakes and the energy release are considered. Hourly data of soil temperature have been acquired since January 2004 in different locations along the rim and within the crater. The observed changes of temperature are studied to establish a temporal-based correlation with the volcanic activity and/or with external forcing, as variations of the regional and local stress field acting on the volcano or meteorological phenomena. The comparison between seismic activity and temperature data highlights significant variations possibly related to changes in fluid circulation in the hydrothermal system of the volcano. The common continuous observations start just before a very shallow earthquake occurred in August 2005, which was preceded by a thermal anomaly. This coincidence has been interpreted as related to fluid-driven rock fracturing, as observed in other volcanoes. For the successive temporal patterns, the seismicity rate and energy release are characterized by slight variations accompanied by changes in temperature. This evidence of reactivity of the fumarole thermal field to seismic strain can be used to discriminate between tectonic and volcanic signals at Mt. Vesuvius
Benefici e svantaggi delle eparine a basso peso molecolare
Premesse e Scopo dello studio: Le eparine a basso peso molecolare vengono utilizzate per la prevenzione e il trattamento della coagula- zione del sangue, l’obiettivo è quello di ridurre al minimo gli effetti collaterali in seguito alla somministrazione delle varie molecole. Metodi e Risultati: L’analisi stata effettuata presso il Dipartimento di Chirurgia Generale e di Urgenza dell’A.O. Ospedali riuniti Villa Sofia - Cervello, su un campione di circa 80 pazienti con età compresa tra i 35-80 anni, 50 sono di sesso femminile e 30 sono di sesso maschile, sono stati riscontrati dall'osservazione effettuata i seguenti effetti collaterali: per quanto riguarda la Parnaparina e la Bemiparina sanguinamento delle gengive durante il lavaggio dei denti maggiormente in soggetti anziani (3 donne); mestruazioni particolarmente abbondanti (7 donne); eccessiva perdita di sangue per tagli o piccole ferite (5 donne e 5 uomini); ematomi in sede d'inezione (in tutti i pazienti osservati). Conclusioni: Dalle analisi finali possiamo dedurre che la Parnaparina e la Bemiparina svolgono un’intensa e rapida dissoluzione di trombi che possono essersi formati nelle arterie o nelle vene mentre con la Nadroparina e con l’Enoxaparina non abbiamo mai osservato variazioni dell'A.P. E della P.T.T
Total CO2 output from Vulcano island (Aeolian Islands, Italy)
Total CO2 output from fumaroles, soil gas, bubbling gas discharges and water dissolved gases discharged
from the island, was estimated for Vulcano island, Italy. The CO2 emission from fumaroles from the La
Fossa summit crater was estimated from the SO2 crater output, while CO2 discharged through diffuse soil
emission was quantified on the basis of 730 measurements of CO2 fluxes from the soil of the island, performed
by using the accumulation chamber method. The results indicate an overall output of ≅500 t day 1
of CO2 from the island. The main contribution to the total CO2 output comes from the summit area of
the La Fossa cone (453 t day 1), with 362 t day 1 from crater fumaroles and 91 t day 1 from crater soil
degassing. The release of CO2 from peripheral areas is ≅20 t day 1 by soil degassing (Palizzi and Istmo areas
mainly), an amount comparable to both the contribution of water dissolved CO2 (6 t day 1), as well as to
seawater bubbling CO2 (4 t day 1 measured in the Istmo area). Presented data (September 2007) refer to a
period of moderate solphataric activity, when the fumaroles temperature were 450°C and gas/water
molar ratio of fumaroles was up to 0.16. The calculated total CO2 emission allows the estimation of the mass release and related thermal energy from the volcanic-hydrothermal system
- …