401 research outputs found
Kinematics and Magnetic Properties of a Light Bridge in a Decaying Sunspot
We present the results obtained by analyzing high spatial and spectral
resolution data of the solar photosphere acquired by the CRisp Imaging
SpectroPolarimeter at the Swedish Solar Telescope on 6 August 2011, relevant to
a large sunspot with a light bridge (LB) observed in NOAA AR 11263. These data
are complemented by simultaneous Hinode Spectropolarimeter (SP) observation in
the Fe I 630.15 nm and 630.25 nm lines. The continuum intensity map shows a
discontinuity of the radial distribution of the penumbral filaments in
correspondence with the LB, which shows a dark lane (about 0.3" wide and about
8.0" long) along its main axis. The available data were inverted with the
Stokes Inversion based on Response functions (SIR) code and physical parameters
maps were obtained. The line-of-sight (LOS) velocity of the plasma along the LB
derived from the Doppler effect shows motions towards and away from the
observer up to 0.6 km/s, which are lower in value than the LOS velocities
observed in the neighbouring penumbral filaments. The noteworthy result is that
we find motions toward the observer up to 0.6 km/s in the dark lane where the
LB is located between two umbral cores, while the LOS velocity motion toward
the observer is strongly reduced where the LB is located between an umbral core
at one side and penumbral filaments on the other side. Statistically, the LOS
velocities correspond to upflows/downflows andcomparing these results with
Hinode/SP data, we conclude that the surrounding magnetic field configuration
(whether more or less inclined) could have a role in maintaining the conditions
for the process of plasma piling up along the dark lane. The results obtained
from our study support and confirm outcomes of recent magnetohydro-dynamic
simulations showing upflows along the main axis of a LBs
Mesenchymal stem cells derived from inflamed gingival tissue for in vivo bone tissue engineering: preliminary results.
Clastogenicity and aneuploidy in newborn and adult mice exposed to 50 Hz magnetic fields.
Purpose:?To detect possible clastogenic and aneugenic properties of a 50 Hz, 650 ?T magnetic field. Materials and methods:?The micronucleus test with CREST (Calcinosis, Raynaud's phenomenon, Esophageal dismotility, Sclerodactility, Telangectasia) antibody staining was performed on liver and peripheral blood sampled from newborn mice exposed to an ELF (Extremely Low Frequency) magnetic field during the whole intra-uterine life (21 days), and on bone marrow and peripheral blood sampled from adult mice exposed to the same magnetic field for the same period. Results:?Data obtained in newborn mice show a significant increase in micronuclei frequencies. In absolute terms, most of the induced micronuclei were CREST-negative (i.e., formed by a chromosome fragment). However, in relative terms, ELF exposure caused a two-fold increase in CREST-negative micronuclei and a four-fold increase in CREST-positive micronuclei (i.e., formed by a whole chromosome). No significant effect was recorded on exposed adults. Conclusions:?These findings suggest the need for investigation of aneugenic properties of ELF magnetic fields in order to establish a possible relationship to carcinogenesis
Leachate analyses of volcanic ashes from Stromboli volcano: A proxy for the volcanic gas plume composition?
Many volcanoes show a change in chemical composition of the gas phase prior to
periods of eruptive activity. Fineâgrained tephra erupted from active vents and transported
through volcanic plumes can adsorb, and therefore rapidly scavenge, volatile elements
such as sulfur, halogens, and metal species in the form of soluble salts adhering to ash
surfaces. Analysis of such waterâsoluble surface materials is a suitable supplement for
remote monitoring of volcanic gases at inaccessible volcanoes. In this work, ash samples
of the 2004 to 2009 eruptive activity of Stromboli volcano were sampled, leached, and
analyzed for major and trace elements. Data analysis and interpretation was focused
on determining the relationship between chemical composition of waterâsoluble
components adhering to volcanic ash and the volcanoâs activity state. First results show
significant temporal variations in ash leachate compositions, reflecting changes in the
eruptive style of the volcano. In particular, we reveal that ash leachates S/F and Mg/Na
ratios showed marked increases prior to a largeâscale explosion on 15 March 2007.PublishedD172041.2. TTC - Sorveglianza geochimica delle aree vulcaniche attiveJCR Journalreserve
A Bayesian approach for the assessment of shallow and deep aquifers susceptibility to point sources contamination in the Province of Milan, Italy
In densely populated areas, urban and industrial activities are responsible for groundwater quality deterioration due to point sources contamination (Kuroda and Fukushi, 2008). In the Province of Milan (Northern Italy), the available water-quality data indicate the occurrence of high PCE+TCE and chromium concentrations in the unconfined shallow as well as in the confined deep aquifers. To cope with this problem, statistical methods can represent reliable tools to provide key information for groundwater management and protection
The 2007 Stromboli eruption: Event chronology and effusion rates using thermal infrared data
Using thermal infrared images recorded by a permanent thermal camera network maintained on Stromboli volcano (Italy), together with satellite and helicopterâbased thermal image surveys, we have compiled a chronology of the events and processes occurring before and during Stromboliâs 2007 effusive eruption. These digital data also allow us to calculate the effusion rates and lava volumes erupted during the effusive episode.
At the onset of the 2007 eruption, two parallel eruptive fissures developed within the northeast crater, eventually breaching the NE flank of the summit cone and extending along the easternmargin of the Sciara del Fuoco. These fed amain effusive vent at 400m above sea level to feed lava flows that extended to the sea. The effusive eruption was punctuated,on 15 March, by a paroxysm with features similar to those of the 5 April paroxysm that occurred during the 2002â2003 effusive eruption. A total of between 3.2 Ă 106 and 11 Ă 106 m3
of lava was erupted during the 2007 eruption, over 34 days of effusive activity. More than half of this volume was emplaced during the first 5.5 days of the eruption. Although the 2007 effusive eruption had an erupted volume comparable to that of the previous (2002â2003) effusive eruption, it had a shorter duration and thus a mean output rate (=total volume divided by eruption duration) that was 1 order of magnitude higher than that of the 2002â
2003 event (âŒ2.4 versus 0.32 ± 0.28 m3
sâ1). In this paper, we discuss similarities and differences between these two effusive events and interpret the processes occurring in 2007 in terms of the recent dynamics witnessed at Stromboli
The 2007 Stromboli eruption: event chronology and effusion rates using thermal infrared data
Using thermal infrared images recorded by a permanent thermal camera network maintained on Stromboli volcano (Italy), together with satellite and helicopter-based thermal image surveys, we have compiled a chronology of the events and processes occurring before and during Stromboliâs 2007 effusive eruption. These digital data also allow us to calculate the effusion rates and lava volumes erupted during the effusive episode. At the onset of the 2007 eruption, two parallel eruptive fissures developed within the North East crater, eventually breaching the NE flank of the summit cone and extending along the eastern margin of the Sciara del Fuoco. These fed a main effusive vent at 400 m a.s.l. to feed lava flows that extended to the sea. The effusive eruption was punctuated, on 15 March, by a paroxysm with features similar to the 5 April paroxysm that occurred during the 2002-03 effusive eruption. A total of between 3.2 x 106 m3 and 11 x 106 m3 of lava was erupted during the 2007 eruption over 34 days of effusive activity. More than half of this volume was emplaced during the first 5.5 days of the eruption. Although the 2007 effusive eruption had a comparable erupted volume to the previous (2002-03) effusive eruption, it had a shorter duration and thus a mean output rate (= total volume divided by eruption duration) that was one order of magnitude greater than the 2002-03 event (~2.4 m3 s-1 compared with 0.32±0.28 m3 s-1). In this paper, we discuss similarities and differences between these two effusive events, and interpret the processes occurring in 2007 in terms of the recent dynamics witnessed at Stromboli
Automatic Classification of eruptive events by the VAMOS system
An automatic system named VAMOS (Volcanic Activity
MOnitoring System) for monitoring volcanic activity at Mt. Etna and
Stromboli volcanoes, is at the present under test at the data collection
center at IIV (Istituto Internazionale di Vulcanologia, CNR, Catania). This
system allows automatic recognition of volcanic activity by on-line
processing of images collected by the surveillance cameras positioned close
to the summit crater of two above mentioned volcanoes which are
worldwide known to be characterized by a persistent eruptive activity.
Based on this automatic system, a new software tool to extract quantitative
information from collected images is now under developing. Several tasks
have been planned to solve by using this tool such as the automatic
classification of recorded events and the computation of relaxed energy
based on stereo-vision and thermal images. One of the first result of the
undertaken research activity has been the automatic classification of the
type of volcanic events and the localization of the eruptive event
The signature of longevity in Sicily
Ageing is a natural and physiological condition that is the result of compromised stress response,
homeostatic imbalance and increased risk of developing diseases. However, if aging with good health
and functions (successful ageing) and aging with disease and disability (unsuccessful ageing) depends
on a combination of âpositive featuresâ, including genetic, epigenetic and phenotypic characteristics
in combination with favourable environment, economic status and social involvement. In our study,
we summarize some key points for the identification of a longevity signature, with a particular focus
on long-living Sicilian individuals and centenarians. Analysing three different Sicilian cohorts (young,
people with no centenarian parents and long-living individuals (LLI) aged >90) we found APOE e3e3
in our LLIs and no presence of e4. Regarding FOXO rs2802292 G-allele (G>T) we did not observe an
association with longevity, probably because of the small sample of centenarians studied. Regarding
haematological and anthropometric results, it is still difficult to point specific longevity features and so
far, we cannot specify a single one. On the other hand, we believe that the synergy among genetics and
environment might create successful interaction to achieve and obtain effective longevity
Dynamic properties along the neutral line of a delta spot inferred from high-resolution observations
Delta (ÎŽ) spots are complex magnetic configurations of sunspots characterized by umbrae of opposite polarity sharing a common penumbra. In order to investigate the fine structure of the region separating the two magnetic polarities of a ÎŽ spot, we studied the morphology, the magnetic configuration, and the velocity field in such a region using observations of active region (AR) NOAA 11267 obtained with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish Solar Telescope on 2011 August 6. The analysis of CRISP data shows upflows and downflows of ~ ± 3 km sâ1 in proximity of the ÎŽ spot polarity inversion line (PIL), and horizontal motions along the PIL of the order of ~1 km sâ1. The results obtained from the SIR inversion of CRISP data also indicate that the transverse magnetic field in the brighter region separating the two opposite magnetic polarities of the ÎŽ spot is tilted about ~45° with respect to the PIL. Solar Dynamics Observatory/Helioseismic and Magnetic Imager observations confirm the presence of motions of ~ ± 3 km sâ1 in proximity of the PIL, which were observed to last 15 hr. From the data analyzed, we conclude that the steady, persistent, and subsonic motions observed along the ÎŽ spot PIL can be interpreted as being due to Evershed flows occurring in the penumbral filaments that show a curved, wrapped configuration. The fluting of the penumbral filaments and their bending, continuously increased by the approaching motion of the negative umbra toward the positive one, give rise to the complex line-of-sight velocity maps that we observed.
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