438 research outputs found
Microbial responses to elevated temperature: Evaluating bentonite mineralogy and copper canister corrosion within the long-term stability of Deep Geological Repositories of nuclear waste
Deep Geological Repositories (DGRs) consist of radioactive waste contained in corrosion-resistant canisters, surrounded by compacted bentonite clay, and buried few hundred meters in a stable geological formation. The effects of bentonite microbial communities on the long-term stability of the repository should be assessed. This study explores the impact of harsh conditions (60 ºC, highly-compacted bentonite, low water activity), and acetate:lactate:sulfate addition, on the evolution of microbial communities, and their effect on the bentonite mineralogy, and corrosion of copper material under anoxic conditions. No bentonite illitization was observed in the treatments, confirming its mineralogical stability as an effective barrier for future DGR. Anoxic incubation at 60 ºC reduced the microbial diversity, with Pseudomonas as the dominant genus. Culture-dependent methods showed survival and viability at 60 ºC of moderate-thermophilic aerobic bacterial isolates (e.g., Aeribacillus). Despite the low presence of sulfate-reducing bacteria in the bentonite blocks, we proved their survival at 30 ºC but not at 60 ºC. Copper disk´s surface remained visually unaltered. However, in the acetate:lactate:sulfate-treated samples, sulfide/sulfate signals were detected, along with microbial-related compounds. These findings offer new insights into the impact of high temperatures (60ºC) on the biogeochemical processes at the compacted bentonite/Cu canister interface post-repository closure
How many invariant polynomials are needed to decide local unitary equivalence of qubit states?
Given L-qubit states with the fixed spectra of reduced one-qubit density
matrices, we find a formula for the minimal number of invariant polynomials
needed for solving local unitary (LU) equivalence problem, that is, problem of
deciding if two states can be connected by local unitary operations.
Interestingly, this number is not the same for every collection of the spectra.
Some spectra require less polynomials to solve LU equivalence problem than
others. The result is obtained using geometric methods, i.e. by calculating the
dimensions of reduced spaces, stemming from the symplectic reduction procedure.Comment: 22 page
Impact of compacted bentonite microbial community on the clay mineralogy and copper canister corrosion: a multidisciplinary approach in view of a safe Deep Geological Repository of nuclear wastes
The Deep Geological Repository (DGR) is the preferred option for the final disposal of high-level radioactive waste. Microorganisms could affect the safety of the DGR by altering the mineralogical properties of the compacted bentonite or inducing the corrosion of the metal canisters. In this work, the impact of physicochemical parameters (bentonite dry density, heat shock, electron donors/acceptors) on the microbial activity, stability of compacted bentonite and corrosion of copper (Cu) discs was investigated after one-year anoxic incubation at 30 ºC. No-illitization in the bentonite was detected confirming its structural stability over 1 year under the experimental conditions. The microbial diversity analysis based on 16S rRNA Next Generation Sequencing showed slight changes between the treatments with an increase of aerobic bacteria belonging to Micrococcaceae and Nocardioides in heat-shock tyndallized bentonites. The survival of sulfate-reducing bacteria (the main source of Cu anoxic corrosion) was demonstrated by the most probable number method. The detection of CuxS precipitates on the surface of Cu metal in the bentonite/Cu metal samples amended with acetate/lactate and sulfate, indicate an early stage of Cu corrosion. Altogether, the outputs of this study help to better understand the predominant biogeochemical processes at the bentonite/Cu canister interface upon DGR closure
Acquired Factor X Deficiency in Light Chain Amyloidosis: A Report of 2 Korean Cases
Amyloidosis is a heterogeneous group of diseases in which misfolding of extracellular proteins is the pathogenic factor. Light chain amyloidosis (AL) is the most common form of amyloidosis, and the causative proteins in AL are the immunoglobulin light chains produced by clonal plasma cells. Hemorrhagic events, ranging from mild subcutaneous hemorrhage to life-threatening bleeding, account for a significant proportion of morbidities and mortality in AL patients. Deficiency of factor X from deposition into amyloid fibrils has been reported to be the most common acquired factor deficiency in AL. We herein report 2 patients with acquired factor X deficiency in AL. A 55-yr-old woman with AL had a prolonged prothrombin time (PT) and an activated partial thromboplastin time (aPTT) of 2.51 International Normalized Ratio (INR) and 75.1 sec, respectively, which were corrected on mixing with normal plasma. Factor X activity was markedly decreased at 5%. The other patient was a 67-yr-old man with AL with a PT of 1.63 INR and an aPTT of 50.3 sec, which were corrected on mixing with normal plasma. Factor X activity was decreased at 17%. Neither of the patients had apparent hemorrhagic manifestations. Identification of acquired factor deficiency and timely coagulation tests are needed in the diagnostic workup and management in AL
Peripheral Innate Immune Activation Correlates With Disease Severity in GRN Haploinsufficiency.
Objective: To investigate associations between peripheral innate immune activation and frontotemporal lobar degeneration (FTLD) in progranulin gene (GRN) haploinsufficiency. Methods: In this cross-sectional study, ELISA was used to measure six markers of innate immunity (sCD163, CCL18, LBP, sCD14, IL-18, and CRP) in plasma from 30 GRN mutation carriers (17 asymptomatic, 13 symptomatic) and 29 controls. Voxel based morphometry was used to model associations between marker levels and brain atrophy in mutation carriers relative to controls. Linear regression was used to model relationships between plasma marker levels with mean frontal white matter integrity [fractional anisotropy (FA)] and the FTLD modified Clinical Dementia Rating Scale sum of boxes score (FTLD-CDR SB). Results: Plasma sCD163 was higher in symptomatic GRN carriers [mean 321 ng/ml (SD 125)] compared to controls [mean 248 ng/ml (SD 58); p < 0.05]. Plasma CCL18 was higher in symptomatic GRN carriers [mean 56.9 pg/ml (SD 19)] compared to controls [mean 40.5 pg/ml (SD 14); p < 0.05]. Elevation of plasma LBP was associated with white matter atrophy in the right frontal pole and left inferior frontal gyrus (p FWE corrected <0.05) in all mutation carriers relative to controls. Plasma LBP levels inversely correlated with bilateral frontal white matter FA (R2 = 0.59, p = 0.009) in mutation carriers. Elevation in plasma was positively correlated with CDR-FTLD SB (b = 2.27 CDR units/μg LBP/ml plasma, R2 = 0.76, p = 0.003) in symptomatic carriers. Conclusion: FTLD-GRN is associated with elevations in peripheral biomarkers of macrophage-mediated innate immunity, including sCD163 and CCL18. Clinical disease severity and white matter integrity are correlated with blood LBP, suggesting a role for peripheral immune activation in FTLD-GRN
Impact of compacted bentonite microbial community on the clay mineralogy and copper canister corrosion: a multidisciplinary approach in view of a safe Deep Geological Repository of nuclear wastes
Deep Geological Repository (DGR) is the preferred option for the final disposal of high-level radioactive waste. Microorganisms could affect the safety of the DGR by altering the mineralogical properties of the compacted bentonite or inducing the corrosion of the metal canisters. In this work, the impact of physicochemical parameters (bentonite dry density, heat shock, electron donors/acceptors) on the microbial activity, stability of compacted bentonite and corrosion of copper (Cu) discs was investigated after one-year anoxic incubation at 30 ºC. No-illitization in the bentonite was detected confirming its structural stability over 1 year under the experimental conditions. The microbial diversity analysis based on 16 S rRNA gene Next Generation Sequencing showed slight changes between the treatments with an increase of aerobic bacteria belonging to Micrococcaceae and Nocardioides in heat-shock tyndallized bentonites. The survival of sulfate-reducing bacteria (the main source of Cu anoxic corrosion) was demonstrated by the most probable number method. The detection of CuxS precipitates on the surface of Cu metal in the bentonite/Cu metal samples amended with acetate/lactate and sulfate, indicated an early stage of Cu corrosion. Overall, the outputs of this study help to better understand the predominant biogeochemical processes at the bentonite/Cu canister interface upon DGR closure
Torsion, topology and CPT anomaly in two-dimensional chiral U(1) gauge theory
We consider the CPT anomaly of two-dimensional chiral U(1) gauge theory on a
torus with topologically nontrivial zweibeins corresponding to the presence of
spacetime torsion. The resulting chiral determinant can be expressed in terms
of the standard chiral determinant without torsion, but with modified spinor
boundary conditions. This implies that the two-dimensional CPT anomaly can be
moved from one spin structure to another by choosing appropriate zweibeins.
Similar results apply to higher-dimensional chiral gauge theories.Comment: LaTeX with elsart.cls, 20 pages, v3: to appear in Nucl. Phys.
The B-quadrilateral lattice, its transformations and the algebro-geometric construction
The B-quadrilateral lattice (BQL) provides geometric interpretation of Miwa's
discrete BKP equation within the quadrialteral lattice (QL) theory. After
discussing the projective-geometric properties of the lattice we give the
algebro-geometric construction of the BQL ephasizing the role of Prym varieties
and the corresponding theta functions. We also present the reduction of the
vectorial fundamental transformation of the QL to the BQL case.Comment: 23 pages, 3 figures; presentation improved, some typos correcte
Convexity of momentum map, Morse index, and quantum entanglement
We analyze form the topological perspective the space of all SLOCC
(Stochastic Local Operations with Classical Communication) classes of pure
states for composite quantum systems. We do it for both distinguishable and
indistinguishable particles. In general, the topology of this space is rather
complicated as it is a non-Hausdorff space. Using geometric invariant theory
(GIT) and momentum map geometry we propose a way to divide the space of all
SLOCC classes into mathematically and physically meaningful families. Each
family consists of possibly many `asymptotically' equivalent SLOCC classes.
Moreover, each contains exactly one distinguished SLOCC class on which the
total variance (a well defined measure of entanglement) of the state Var[v]
attains maximum. We provide an algorithm for finding critical sets of Var[v],
which makes use of the convexity of the momentum map and allows classification
of such defined families of SLOCC classes. The number of families is in general
infinite. We introduce an additional refinement into finitely many groups of
families using the recent developments in the momentum map geometry known as
Ness stratification. We also discuss how to define it equivalently using the
convexity of the momentum map applied to SLOCC classes. Moreover, we note that
the Morse index at the critical set of the total variance of state has an
interpretation of number of non-SLOCC directions in which entanglement
increases and calculate it for several exemplary systems. Finally, we introduce
the SLOCC-invariant measure of entanglement as a square root of the total
variance of state at the critical point and explain its geometric meaning.Comment: 37 pages, 2 figures, changes in the manuscript structur
Finite Temperature Schwinger Model with Chirality Breaking Boundary Conditions
The -flavour Schwinger Model on a finite space and
subject to bag-type boundary-conditions at und is solved at
finite temperature . The boundary conditions depend on a real
parameter and break the axial flavour symmetry. We argue that this
approach is more appropriate to study the broken phases than introducing small
quark masses, since all calculations can be performed analytically. In the
imaginary time formalism we determine the thermal correlators for the
fermion-fields and the determinant of the Dirac-operator in arbitrary
background gauge-fields. We show that the boundary conditions induce a CP-odd
-term in the effective action. The chiral condensate, and in particular
its T- and L- dependence, is calculated for fermions. It is seen to
depend on the order in which the two lengths and are sent to
infinity.Comment: One reference added plus one corrected, final version as to be
published in Annals of Physic
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