1,643 research outputs found
The role of syn-eruptive vesiculation on explosive basaltic activity at Mt. Etna, Italy
We investigated the dynamics of explosive activity at Mt. Etna between 31 August and 15 December 2006 by combining vesicle studies in the erupted products with measurements of the gas composition at the active, summit crater. The analysed scoria clasts present large, connected vesicles with complex shapes and smaller, isolated, spherical vesicles, the content of which increases in scoriae from the most explosive events. Gas geochemistry reports CO2/SO2 and SO2/HCl ratios supporting a deep-derived gas phase for fire-fountain activity. By integrating results from scoria vesiculation and gas analysis we find that the highest energy episodes of Mt. Etna activity in 2006 were driven by a previously accumulated CO2-rich gas phase but we highlight the lesser role of syn-eruptive vesicle nucleation driven by water exsolution during ascent. We conclude that syn-eruptive vesiculation is a common process in Etnean magmas that may promote a deeper conduit magma fragmentation and increase ash formation
Detection of microplastic contamination in comercial insect meals.
Background: Escalating global plastic production, expected to reach 34,000 million tons
by 2050, poses a significant threat to human and environmental well-being, particularly in aquatic
ecosystems. Microplastics (MP) and nanoplastics (NP), which originate from the degradation of plastics, are of concern due to their potential bioaccumulation and uptake of pollutants. This study addresses identification methods and focuses on insect meal, a raw material for aquaculture feed.
Methods: By using different techniques, the study was able to detect MP and NP in insect meal
samples. Chemical digestion with KOH at 60 ◦C efficiently removed organic matter without affecting the synthetic polymer polyethylene (PE). Filtration, confocal Raman microscopy, SEM, and TEM
were used for comprehensive analysis, and integrity tests on PE films were performed using Ramanand FTIR spectroscopy. The results showed the presence of PE microplastic particles in the insect meal, which was confirmed by correlative Raman and SEM mapping on a positively charged surface.
In addition, the increased resolution of the Raman microscope identified submicrometric PE NP (800 nm). Transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX) confirmed plastic-like structures in the insect meal, highlighting the presence of PE plastics characterized by irregular shapes and some agglomeration. The higher carbon concentration in the EDX analysis supported the plastic nature, which was also confirmed by Raman spectroscopy.
Conclusions: The study provides a robust method for the detection of MP and NP in insect meal and provides valuable insight into the possible presence of plastics in insect-based aquafeeds. The combination of different analytical methods increases the reliability of the results and sets the for future investigations that could focus on the quantification of NP and the assessment of their potential environmental impact
The role of syn-eruptive vesiculation on explosive basaltic activity at Mt. Etna, Italy
We investigated the dynamics of explosive activity at Mt. Etna between 31 August and 14 December 2006 by combining vesicle studies in the erupted products with measurements of the gas composition at the active, summit crater. The analysed scoria clasts present large, connected vesicles with complex shapes and smaller, isolated, spherical vesicles, the content of which increases in scoriae from the most explosive events. Gas geochemistry reports CO2/SO2 and SO2/HCl ratios supporting a deep-derived gas phase for fire-fountain activity. By integrating results from scoria vesiculation and gas analysis we find that the highest energy episodes of Mt. Etna activity in 2006 were driven by a previously accumulated CO2-rich gas phase but we highlight the lesser role of syn-eruptive vesicle nucleation driven by water exsolution during ascent. We conclude that syn-eruptive vesiculation is a common process in Etnean magmas that may promote a deeper conduit magma fragmentation and increase ash formatio
Infrared spectral characterisation of some volcanic rocks on Mt. Etna with in-situ instruments, June 2007
Toxicological Findings of Self-Poisoning Suicidal Deaths: A Systematic Review by Countries
The use of illicit and non-illicit substances is widespread in suicides. The toxicological data may help in understanding the mechanism of death. This systematic review aimed to analyze autopsies related to suicides by consuming poison, focusing on the correlation between substance use and the country of origin to create an alarm bell to indicate that suicide maybe attempted and prevent it. The systematic review was conducted according to the PRISMA guidelines, with the primary objective of identifying autopsies conducted in cases of suicide by consuming poison in specific
geographic areas. Significant differences in substances were observed between low-income and Western countries that confirm previous literature data. In rural areas and Asian countries, most suicides by consuming poison involve the use of pesticides, such as organophosphates and carbamates. In Western countries, illicit drugs and medically prescribed drugs are the leading cause of suicide by self-poisoning. Future research should shed light on the correlation between social, medical, and demographic characteristics and the autopsy findings in suicides by self-poisoning to highlight the risk factors and implement tailored prevention programs worldwide. Performing a complete autopsy on a suspected suicide by self-poisoning could be essential in supporting worldwide public health measures and policy makers. Therefore, complete autopsies in such cases must be vigorously promoted
Investigation about the presence of 20-hydroxyecdysone and flavonoids in several plant species and in a terrestrial isopod target species, Armadillo officinalis (Dumeril, 1816) (Crustacea, Isopoda, Oniscidea)
Degassing behavior of Mt. Etna volcano (Italy) during 2007-2008, inferred
Studies on volcanic degassing have recently shown the important role of volatile release from active volcanoes
in understanding magmatic processes prior to eruptions. Here we present and discuss the evolution of magmatic
degassing that preceded and accompanied the 2008 Mt. Etna eruption. We tracked the ascent of magma bodies
by high-temporal resolution measurements of SO2 emission rates and discrete sampling of SO2/HCl and SO2/HF
molar ratios in the crater plume, as well as by periodic measurement of soil CO2 emission rates. Our data suggest
that the first signs of upward migration of gas-rich magma before the 2008 eruption were observed in June 2007,
indicated by a strong increase in soil CO2 efflux followed by a slow declining trend in SO2 flux and halogens. This
degassing behavior preceded the mid-August 2007 summit activity culminated with the September 4th paroxysmal
event. Five months later, a new increase in both soil CO2 and SO2 emission rates occurred before the November
23rd paroxysm, to drop down in late December. In the following months, geochemical parameters showed high
variability, characterized by isolated sudden increases occurred in early December 2007 and late March 2008. In
early May soil CO2, SO2 emission rates and S/Cl molar ratio gradually increased. Crater degassing peaked on
May 13th marking the onset of the eruption. Eruptive activity was accompanied by a general steady-state of SO2
flux characterized by two main degassing cycles. These cycles preceded explosive activity at the eruptive vents,
indicating terminal new-arrival of deep gas-rich magma bodies in the shallow plumbing system of Mt Etna. Conversely,
halogens described a slight increasing trend till the end of 2008. These observations suggest an impulsive
syn-eruptive dynamics of magma transfer from depth to the surface. Differently from the SO2 emission rates, the
S/Cl ratio and the soil CO2 efflux values showed an increasing trend from mid-April to mid-July 2008, indicating
steady-increasing input of deeper, gas-rich magma. Since August, geochemical parameters decreased, suggesting
that new magma has not arrived from depth. According to our interpretation, both the CO2 efflux and the S/Cl ratio
increases observed in early November may indicate a new input of fresh magma form depth. Finally, the estimated
volume of degassing magma showed substantial equilibrium between degassed and erupted magma suggesting an
“eruptive” steady-state of the volcano
Psychological and personality assessment in patients candidates for Uterus Transplantation from deceased donor: preliminary results
n/
New findings on asteroid spin-vector distributions
Abstract The number of known spin vectors of main belt and near-Earth asteroids is regularly growing, including new objects, and updating the estimates concerning known cases, with the aid of new observations and of improved observational techniques. A reliable statistical analysis of the spin vectors is now possible. In general the poles (both for MB bodies and for NEAs) are not isotropically distributed, as some general theoretical considerations may predict. Main belt asteroids show a lack of poles close to the ecliptic plane. There is a marginally significant excess of prograde spinners in the 100-150 km size range, but interestingly there is not a statistically significant excess in the larger size range. Among NEAs, there is an excess of retrograde rotations. The distributions of longitudes of poles of both groups do not show statistically significant deviations from random. We discuss the possible physical implications of the various resulting pole anisotropies in terms of dynamical-mainly non-gravitational-effects, and point out the importance of new observational campaigns, mainly devoted to compute the poles of small bodies and of the members of asteroid dynamical families
An unloading foam model to constrain Etna’s 11–13 January 2011 lava fountaining episode
The 11–13 January 2011 eruptive episode at Etna volcano occurred after several months
of increasing ash emissions from the summit craters, and was heralded by increasing
SO2 output, which peaked at ∼5000 megagrams/day several hours before the start of the
eruptive activity. The eruptive episode began with a phase of Strombolian activity from a pit
crater on the eastern flank of the SE‐Crater. Explosions became more intense with time
and eventually became transitional between Strombolian and fountaining, before moving
into a lava fountaining phase. Fountaining was accompanied by lava output from the lower
rim of the pit crater. Emplacement of the resulting lava flow field, as well as associated lava
fountain‐ and Strombolian‐phases, was tracked using a remote sensing network comprising
both thermal and visible cameras. Thermal surveys completed once the eruptive episode
had ended also allowed us to reconstruct the emplacement of the lava flow field. Using a high
temporal resolution geostationary satellite data we were also able to construct a detailed
record of the heat flux during the fountain‐fed flow phase and its subsequent cooling. The
dense rock volume of erupted lava obtained from the satellite data was 1.2 × 106 m3; this
was emplaced over a period of about 6 h to give a mean output rate of ∼55 m3 s−1. By
comparison, geologic data allowed us to estimate dense rock volumes of ∼0.85 × 106 m3
for the pyroclastics erupted during the lava fountain phase, and 0.84–1.7 × 106 m3 for
lavas erupted during the effusive phase, resulting in a total erupted dense rock volume of
1.7–2.5 × 106 m3 and a mean output rate of 78–117 m3 s−1. The sequence of events and
quantitative results presented here shed light on the shallow feeding system of the volcano
- …