64 research outputs found
Will the Antarctic tardigrade Acutuncus antarcticus be able to withstand environmental stresses related to global climate change?
Because conditions in continental Antarctica are highly selective and extremely hostile to life, its biota is depauperate, but well adapted to live in this region. Global climate change has the potential to impact continental Antarctic organisms because of increasing temperatures and ultraviolet radiation. This research evaluates how ongoing climate changes will affect Antarctic species, and whether Antarctic organisms will be able to adapt to the new environmental conditions. Tardigrades represent one of the main terrestrial components of Antarctic meiofauna; therefore, the pan-Antarctic tardigrade Acutuncus antarcticus was used as model to predict the fate of Antarctic meiofauna threatened by climate change. Acutuncus antarcticus individuals tolerate events of desiccation, increased emperature and UV radiation. Both hydrated and desiccated animals tolerate increases in UV radiation, even though the desiccated animals are more resistant. Nevertheless, the survivorship of hydrated and desiccated animals is negatively affected by the combination of temperature and UV radiation, with the hydrated animals being more tolerant than desiccated animals. Finally, UV radiation has a negative impact on the life history traits of successive generations of A. antarcticus, causing an increase in egg reabsorption and teratological events. In the long run, A. antarcticus could be at risk of population reductions or even extinction. Nevertheless, because the changes in global climate will proceed gradually and an overlapping of temperature and UV increase could be limited in time, A. antarcticus, as well as many other Antarctic organisms, could have the potential to overcome global warming stresses, and/or the time and capability to adapt to the new environmental conditions
VLBI Observations of a Complete Sample of Radio Galaxies. VII. Study of the FR I Sources 3C 31, 4C 35.03, and 3C 264
We present results from global VLBI and VLA observations of three FanaroU-Riley type I radio gal- axies, 3C 31, 4C 35.03, and 3C 264, at a frequency of 5 GHz. In all three cases, we observe asymmetric parsec-scale structures consisting of a compact core and a single jet pointing in the direction of the more prominent kiloparsec jet. We interpret such alignment as evidence for the relativistic nature of FR I radio jets at parsec scales. Comparing the VLBI and VLA images of these sources, we —nd a progressive deceleration of the plasma —ow from parsec to kiloparsec scales. We consider another —ve FR I radio galaxies studied previously by us and —nd that, in a set of eight FR I objects, the estimated jet bulk velocities and orientation angles with respect to the observer are consistent with the requirements of the uni—cation model for low-power radio sources. Subject headings: galaxies: individual (3C 31, 4C 35.03, 3C 264) ¨ galaxies: jetsgalaxies: structure ¨ radio continuum: galaxie
Resistance to Extreme Stresses by a Newly Discovered Japanese Tardigrade Species, Macrobiotus kyoukenus (Eutardigrada, Macrobiotidae)
Tardigrades are small micrometazoans able to resist several environmental stresses in any
stage of their life cycle. An integrated analysis of tardigrade specimens collected in Tsukuba (Japan)
revealed a peculiar morphology and a new sensory field in the cloaca. Molecular taxonomy and
phylogenetic analysis on different genes (COI, ITS2, 18S and 28S) confirmed that this population is
a new species, Macrobiotus kyoukenus sp. nov., belonging to the widespread Macrobiotus hufelandi
group. The stress resistance capabilities of M. kyoukenus sp. nov. have been tested by submitting
animals to extreme desiccation, rapid freezing, and high levels of ultraviolet radiations (UVB and
UVC). Animals were able to survive desiccation (survivorship 95.71 ± 7.07%) and freezing up to -80
°C (82.33 ± 17.11%). Both hydrated and desiccated animals showed a high tolerance to increasing
UV radiations: hydrated animals survived to doses up to 152.22 kJ m−2 (UVB) and up to 15.00 kJ m−2
(UVC), while desiccated specimens persisted to radiations up to 165.12 kJ m−2 (UVB) and up to 35.00
kJ m−2 (UVC). Present data contribute to the discovery of a larger tardigrade biodiversity in Japan,
and the tolerance capabilities of M
Antioxidant Response during the Kinetics of Anhydrobiosis in Two Eutardigrade Species
Anhydrobiosis, a peculiar adaptive strategy existing in nature, is a reversible capability of organisms to tolerate a severe loss of their body water when their surrounding habitat is drying out. In the anhydrobiotic state, an organism lacks all dynamic features of living beings since an ongoing metabolism is absent. The depletion of water in the anhydrobiotic state increases the ionic concentration and the production of reactive oxygen species (ROS). An imbalance between the increased production of ROS and the limited action of antioxidant defences is a source of biomolecular damage and can lead to oxidative stress. The deleterious effects of oxidative stress were demonstrated in anhydrobiotic unicellular and multicellular organisms, which counteract the effects using efficient antioxidant machinery, mainly represented by ROS scavenger enzymes. To gain insights into the dynamics of antioxidant patterns during the kinetics of the anhydrobiosis of two tardigrade species, Paramacrobiotus spatialis and Acutuncus antarcticus, we investigated the activity of enzymatic antioxidants (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase) and the amount of non-enzymatic antioxidants (glutathione) in the course of rehydration. In P. spatialis, the activity of catalase increases during dehydration and decreases during rehydration, whereas in A. antarcticus, the activity of superoxide dismutase decreases during desiccation and increases during rehydration. Genomic varieties, different habitats and geographical regions, different diets, and diverse evolutionary lineages may have led to the specialization of antioxidant strategies in the two specie
Early csf biomarkers and late functional outcomes in spinal cord injury. A pilot study
open9noThis research was funded by the Italian Ministry of Health—call “Ricerca Finalizzata 2010” (project code RF-2010-2315118).Although, biomarkers are regarded as an important tool for monitoring injury severity and treatment efficacy, and for predicting clinical evolution in many neurological diseases and disorders including spinal cord injury, there is still a lack of reliable biomarkers for the assessment of clinical course and patient outcome. In this study, a biological dataset of 60 cytokines/chemokines, growth factorsm and intracellular and extracellular matrix proteins, analyzed in CSF within 24 h of injury, was used for correlation analysis with the clinical dataset of the same patients. A heat map was generated of positive and negative correlations between biomarkers and clinical rating scale scores at discharge, and between biomarkers and changes in clinical scores during the observation period. Using very stringent statistical criteria, we found 10 molecules which correlated with clinical scores at discharge, and five molecules, which correlated with changes in clinical scores. The proposed methodology may be useful for generating hypotheses regarding “predictive” and “treatment effectiveness” biomarkers, thereby suggesting potential candidates for disease‐modifying therapies using a “bed‐to‐bench” approach.openCapirossi R.; Piunti B.; Fernandez M.; Maietti E.; Rucci P.; Negrini S.; Giovannini T.; Kiekens C.; Calza' L.Capirossi R.; Piunti B.; Fernandez M.; Maietti E.; Rucci P.; Negrini S.; Giovannini T.; Kiekens C.; Calza' L
The SKA view of cool-core clusters: evolution of radio mini-halos and AGN feedback
In about 70% of the population of relaxed, cool-core galaxy clusters, the
brightest cluster galaxy (BCG) is radio loud, showing non-thermal radio jets
and lobes ejected by the central active galactic nucleus (AGN). In recent years
such relativistic plasma has been unambiguously shown to interact with the
surrounding thermal intra-cluster medium (ICM) thanks to spectacular images
where the lobe radio emission is observed to fill the cavities in the
X-ray-emitting gas. This `radio feedback' phenomenon is widespread and is
critical to understand the physics of the inner regions of galaxy clusters and
the properties of the central BCG. At the same time, mechanically-powerful AGN
are likely to drive turbulence in the central ICM which may also play a role
for the origin of non-thermal emission on cluster-scales. Diffuse non-thermal
emission has been observed in a number of cool-core clusters in the form of a
radio mini-halo surrounding the radio-loud BCG on scales comparable to that of
the cooling region. Large mini-halo samples are necessary to establish their
origin and connection with the cluster thermal properties and dynamics,
especially in light of future X-ray characterization of the cluster cores as it
is expected by Athena-XIFU. We show that All-Sky reference survey at Band 2
with SKA1 at confusion limit (rms ~2 {\mu}Jy per beam) has the potential to
detect up to ~620 mini-halos at redshift z<0.6, whereas Deep Tier reference
surveys at Band 1/2 with SKA1 at sub-arcsec resolution (rms ~0.2 {\mu}Jy per
beam) will allow a complete census of the radio-loud BCGs at any redshift down
to a 1.4 GHz power of 10^{22} W/Hz. We further anticipate that SKA2 might
detect up to ~1900 new mini-halos at redshift z<0.6 and characterize the
radio-mode AGN feedback in every cluster and group up to redshift z ~1.7 (the
highest-z where virialized clusters are currently detected).Comment: 17 pages, 5 figures. To appear as part of 'Continuum Science' in
Proceedings of "Advancing Astrophysics with the SKA (AASKA14)",
PoS(AASKA14)07
In hepatocellular carcinoma miR-221 modulates sorafenib resistance through inhibition of caspase-3\u2013mediated apoptosis
Purpose: The aberrant expression of miR-221 is a hallmark of human cancers, including hepatocellular carcinoma (HCC), and its involvement in drug resistance, together with a proved in vivo efficacy of anti-miR-221 molecules, strengthen its role as an attractive target candidate in the oncologic field. The discovery of biomarkers predicting the response to treatments represents a clinical challenge in the personalized treatment era. This study aimed to investigate the possible role of miR-221 as a circulating biomarker in HCC patients undergoing sorafenib treatment as well as to evaluate its contribution to sorafenib resistance in advanced HCC. Experimental Design: A chemically induced HCC rat model and a xenograft mouse model, together with HCC-derived cell lines were employed to analyze miR-221 modulation by Sorafenib treatment. Data from the functional analysis were validated in tissue samples from surgically resected HCCs. The variation of circulating miR-221 levels in relation to Sorafenib treatment were assayed in the animal models and in two independent cohorts of patients with advanced HCC. Results: MiR-221 over-expression was associated with Sorafenib resistance in two HCC animal models and caspase-3 was identified as its target gene, driving miR-221 anti-apoptotic activity following Sorafenib administration. Lower pre-treatment miR-221 serum levels were found in patients subsequently experiencing response to Sorafenib and an increase of circulating miR-221 at the two months assessment was observed in responder patients. Conclusions: MiR-221 might represent a candidate biomarker of likelihood of response to Sorafenib in HCC patients to be tested in future studies. Caspase-3 modulation by miR-221 participates to Sorafenib resistance
A Giant Metrewave Radio Telescope/Chandra view of IRAS 09104+4109: A type 2 QSO in a cooling flow
IRAS 09104+4109 is a rare example of a dust enshrouded type 2 QSO in the
centre of a cool-core galaxy cluster. Previous observations of this z=0.44
system showed that as well as powering the hyper-luminous infrared emission of
the cluster-central galaxy, the QSO is associated with a double-lobed radio
source. However, the steep radio spectral index and misalignment between the
jets and ionised optical emission suggested that the orientation of the QSO had
recently changed. We use a combination of new, multi-band Giant Metrewave Radio
Telescope observations and archival radio data to confirm that the jets are no
longer powered by the QSO, and estimate their age to be 120-160 Myr. This is in
agreement with the ~70-200 Myr age previously estimated for star-formation in
the galaxy. Previously unpublished Very Long Baseline Array data reveal a 200
pc scale double radio source in the galaxy core which is more closely aligned
with the current QSO axis and may represent a more recent period of jet
activity. These results suggest that the realignment of the QSO, the cessation
of jet activity, and the onset of rapid star-formation may have been caused by
a gas-rich galaxy merger. A Chandra X-ray observation confirms the presence of
cavities associated with the radio jets, and we estimate the energy required to
inflate them to be ~7.7x10^60 erg. The mechanical power of the jets is
sufficient to balance radiative cooling in the cluster, provided they are
efficiently coupled to the intra-cluster medium (ICM). We find no evidence of
direct radiative heating and conclude that the QSO either lacks the radiative
luminosity to heat the ICM, or that it requires longer than 100-200 Myr to
significantly impact its environment. [Abridged]Comment: 23 pages, 18 figures and 7 tables. Accepted for publication in MNRA
The Italian open data meteorological portal: MISTRAL
AbstractAt the national level, in Italy, observational and forecast data are collected by various public bodies and are often kept in various small, heterogeneous and non‐interoperable repositories, released under different licenses, thus limiting the usability for external users. In this context, MISTRAL (the Meteo Italian SupercompuTing PoRtAL) was launched as the first Italian meteorological open data portal, with the aim of promoting the reuse of meteorological data sets available at national level coverage. The MISTRAL portal provides (and archives) meteorological data from various observation networks, both public and private, and forecast data that are generated and post‐processed within the Consortium for Small‐scale Modeling‐Limited Area Model Italia (COSMO‐LAMI) agreement using high performance computing (HPC) facilities. Also incorporated is the Italy Flash Flood use case, implemented with the collaboration of European Centre for Medium‐Range Weather Forecasts (ECMWF), which exploits cutting edge advances in HPC‐based post‐processing of ensemble precipitation forecasts, for different model resolutions, and applies those to deliver novel blended‐resolution forecasts specifically for Italy. Finally, in addition to providing architectures for the acquisition and display of observational data, MISTRAL also delivers an interactive system for visualizing forecast data of different resolutions as superimposed multi‐layer maps
A conservation roadmap for the subterranean biome
The 15th UN Convention on Biological Diversity (CBD) (COP15) will be held in Kunming, China in October 2021. Historically, CBDs and other multilateral treaties have either alluded to or entirely overlooked the subterranean biome. A multilateral effort to robustly examine, monitor, and incorporate the subterranean biome into future conservation targets will enable the CBD to further improve the ecological effectiveness of protected areas by including groundwater resources, subterranean ecosystem services, and the profoundly endemic subsurface biodiversity. To this end, we proffer a conservation roadmap that embodies five conceptual areas: (1) science gaps and data management needs; (2) anthropogenic stressors; (3) socioeconomic analysis and conflict resolution; (4) environmental education; and (5) national policies and multilateral agreements.Peer reviewe
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