Ciomadul is the youngest volcano in the Carpathian‐Pannonian Region, Eastern‐Central Europe, which last erupted 30 ka. This volcano is considered to be inactive, however, combined evidence from ...petrologic and magnetotelluric data, as well as seismic tomography studies, suggests the existence of a subvolcanic crystal mush with variable melt content. The volcanic area is characterized by high CO2 gas output rate, with a minimum of 8.7 × 103 t/year. We investigated 31 gas emissions at Ciomadul to constrain the origin of the volatiles. The δ13C–CO2 and 3He/4He compositions suggest the outgassing of a significant component of mantle‐derived fluids. The He isotope signature in the outgassing fluids (up to 3.10 Ra) is lower than the values in the peridotite xenoliths of the nearby alkaline basalt volcanic field (R/Ra 5.95 Ra ± 0.01), which are representative of a continental lithospheric mantle and significantly lower than MORB values. Considering the chemical characteristics of the Ciomadul dacite, including trace element and Sr–Nd and O isotope compositions, an upper crustal contamination is less probable, whereas the primary magmas could have been derived from an enriched mantle source. The low He isotopic ratios could indicate a strongly metasomatized mantle lithosphere. This could be due to infiltration of subduction‐related fluids and postmetasomatic ingrowth of radiogenic He. The metasomatic fluids are inferred to have contained subducted carbonate material resulting in a heavier carbon isotope composition (δ13C is in the range of −1.4‰ to −4.6‰) and an increase of CO2/3He ratio. Our study shows the magmatic contribution to the emitted gases.
Plain Language Summary
Determining the fluxes and composition of gases in active and dormant volcanoes could help to constrain their origin. Ciomadul is the youngest volcano of the Carpathian‐Pannonian Region, Eastern‐Central Europe, where the last eruption occurred 30 ka. Its eruption chronology is punctuated by long quiescence periods (even >100 kyr) separating the active phases; therefore, the long dormancy since the last eruption (30 ka) does not unambiguously indicate inactivity. Knowing if melt‐bearing magma resides in the crust is fundamental to evaluate the nature of the volcano. Isotopic compositions of helium (3He/4He) and carbon (δ13CCO2) are important tools for the study of the origin of the gases. We show that the isotope variation of the emitted gases suggests a metasomatized lithospheric mantle origin for the primary magmas. This is consistent with a degassing deep magma body existing beneath Ciomadul, and this long‐dormant volcano cannot be considered as extinct.
Key Points
CO2 emissions at Ciomadul, Eastern‐Central Europe, suggest a still‐active plumbing system beneath the volcano in spite of long dormancy
The CO2 and He isotope compositions provide evidence for significant contribution of magma‐derived volatiles, up to 80%
Isotopic signatures of gases indicate that primary magmas could have derived from a mantle source modified by subduction‐related fluids
The diagnostic accuracy of the I
3M
to assess the legal age of 18 years has already been tested in several specific-population samples. The left lower third molar has been extensively used for ...discriminating between minors and adults. This research aimed to compare the usefulness of lower third molar maturity indexes, from both left and right side (I
3M
L and I
3M
R), in samples originating from four distinct continents in order to examine possible differences in their accuracy values. For this purpose, a sample of 10,181 orthopantomograms (OPGs), from Europe, Africa, Asia and America, was analysed and previously scored in other studies. The samples included healthy subjects with no systemic disorders with both third molars and clear depicted root apices. Wilcoxon Signed Rank test for left and right asymmetry did not show any significant differences. Data about sensitivity, specificity, predictive values, likelihood ratio and accuracy were pooled together and showed similar results for I
3M
L and I
3M
R, respectively. In addition, all these quantities were high when only the I
3M
R was considered to discriminate between adults and minors. The present referable database was the first to pool third molar measurements using panoramic radiographs of subjects coming from different continents. The results highlighted that both I
3M
L and I
3M
R are reliable indicators for assessing the legal age of 18 years old in those jurisdictions where this legal threshold has been set as the age of majority.
Tuberculosis causes nearly two million deaths per year world-wide. In addition multidrug-resistant mycobacterial strains rapidly emerge so novel therapeutic approaches are needed. Recently, several ...promising mycobacterial target molecules were identified, which are involved in bacterial or host cell signalling e.g. the serine/threonine protein kinases, PknB and PknG, NAD kinase and the NAD synthetase. Here we describe some early efforts in the development of novel signal transduction inhibitory anti-mycobacterial drugs using a multiple target approach, with special emphasis on the kinase inhibitory field. Initially, we are using the Nested Chemical Library™ (NCL) technology and pharmacophore modelling. A hit-finding library, consisting of ∼19000 small molecules with a bias for prototypic kinase inhibitors from our NCL library and commercial sources was virtually screened against these validated target molecules. Protein structures for the virtual screening were taken from the published three dimensional crystal structures of the enzymes. The hits from the virtual screening were subsequently tested in enzymatic assay systems. Potent hits were then tested for biological activity in macrophages, infected with mycobacteria. The final goal of this exercise is not only to identify potent antimycobacterial substances, but also a common pharmacophore for the mycobacterial target PknG in combination with PknB, NAD kinase and/or NAD synthetase. This common pharmacophore still needs to be a unique pharmacophore for the mycobacterial target proteins over human off-targets. Such a pharmacophore might then drive the optimization of a completely new profile of an antibiotic agent with activity against latent mycobacteria and resistance mycobacterial strains.
Oscillation modes of microtubules Kasas, S.; Cibert, C.; Kis, A. ...
Biology of the cell,
December 2004, Letnik:
96, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Microtubules are long, filamentous protein complexes which play a central role in several cellular physiological processes, such as cell division transport and locomotion. Their mechanical properties ...are extremely important since they determine the biological function. In a recently published experiment Phys. Rev. Lett. 89 (2002) 248101, microtubule’s Young’s and shear moduli were simultaneously measured, proving that they are highly anisotropic. Together with the known structure, this finding opens the way to better understand and predict their mechanical behavior under a particular set of conditions. In the present study, we modeled microtubules by using the finite elements method and analyzed their oscillation modes. The analysis revealed that oscillation modes involving a change in the diameter of the microtubules strongly depend on the shear modulus. In these modes, the correlation times of the movements are just slightly shorter than diffusion times of free molecules surrounding the microtubule. It could be therefore speculated that the matching of the two timescales could play a role in facilitating the interactions between microtubules and MT associated proteins, and between microtubules and tubulins themselves.
Recent studies have revealed the qualitative and quantitative importance of the free gas emanations from aqueous environments and from soil surfaces in Romania. Interesting mixing zones of different ...gases can be observed on the boundary between the Miocene sedimentary deposits and Late Miocene volcaniclastics. This study presents the results of investigations of free carbondioxide and methane made in Corund area (Harghita County), at Dealul Melcului geological reserve, where a presumed methane seepage was described in the past. Measurements were performed using a closed chamber method. Our observations and result show the lack of methane emanations, while the maximum value for carbon-dioxide emanation was 458 g/m2/day.
Carbon gas flux from the Dealul Melcului geological reserve (Corund, Romania). Recent studies have revealed the qualitative and quantitative importance of the free gas emanations from aqueous ...environments and from soil surfaces in Romania. Interesting mixing zones of different gases can be observed on the boundary between the Miocene sedimentary deposits and Late Miocene volcaniclastics. This study presents the results of investigations of free carbon-dioxide and methane made in Corund area (Harghita County), at Dealul Melcului geological reserve, where a presumed methane seepage was described in the past. Measurements were performed using a closed chamber method. Our observations and result show the lack of methane emanations, while the maximum value for carbon-dioxide emanation was 458 g/m2/day.
Directed and elliptic flows of neutrons and light charged particles were measured for the reaction 197Au+197Au at 400 MeV/nucleon incident energy within the ASY-EOS experimental campaign at the GSI ...laboratory. The detection system consisted of the Large Area Neutron Detector LAND, combined with parts of the CHIMERA multidetector, of the ALADIN Time-of-flight Wall, and of the Washington-University Microball detector. The latter three arrays were used for the event characterization and reaction-plane reconstruction. In addition, an array of triple telescopes, KRATTA, was used for complementary measurements of the isotopic composition and flows of light charged particles. From the comparison of the elliptic flow ratio of neutrons with respect to charged particles with UrQMD predictions, a value \gamma = 0.72 \pm 0.19 is obtained for the power-law coefficient describing the density dependence of the potential part in the parametrization of the symmetry energy. It represents a new and more stringent constraint for the regime of supra-saturation density and confirms, with a considerably smaller uncertainty, the moderately soft to linear density dependence deduced from the earlier FOPI-LAND data. The densities probed are shown to reach beyond twice saturation.
Attention-deficit hyperactivity disorder (ADHD) is associated with a range of cognitive deficits and social cognition impairments, which might be interpreted in the context of fronto-striatal ...dysfunction. So far only few studies have addressed the issue of social cognition deficits in ADHD.
Medline and Psyclit searches were performed for a 30-year period (1979–2009) using the words ‘ADHD’ and ‘social cognition’, ‘theory of mind’, ‘prosody’, ‘face perception’, ‘humour’ or ‘social information processing’. Inclusion criteria consisted of a diagnosis according to DSM as well as the inclusion of a control group or a follow-up assessment following the treatment with methylphenidate.
ADHD is clearly associated with social cognition impairments involving emotional face and prosody perception. Although the database is sparse so far, there is some evidence for theory of mind deficits and reduced empathy in ADHD.
In summary, the social cognition impairments are consistent with fronto-striatal dysfunction in ADHD, but other functional networks of brain areas also appear to be implicated.
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