49 research outputs found
Total correlations and mutual information
In quantum information theory it is generally accepted that quantum mutual
information is an information-theoretic measure of total correlations of a
bipartite quantum state. We argue that there exist quantum states for which
quantum mutual information cannot be considered as a measure of total
correlations. Moreover, for these states we propose a different way of
quantifying total correlations.Comment: 6 pages, 3 figures, published versio
Quantum Dissension: Generalizing Quantum Discord for Three-Qubit States
We introduce the notion of quantum dissension for a three-qubit system as a
measure of quantum correlations. We use three equivalent expressions of
three-variable mutual information. Their differences can be zero classically
but not so in quantum domain. It generalizes the notion of quantum discord to a
multipartite system. There can be multiple definitions of the dissension
depending on the nature of projective measurements done on the subsystems. As
an illustration, we explore the consequences of these multiple definitions and
compare them for three-qubit pure and mixed GHZ and W states. We find that
unlike discord, dissension can be negative. This is because measurement on a
subsystem may enhance the correlations in the rest of the system. This approach
can pave a way to generalize the notion of quantum correlations in the
multiparticle setting.Comment: 9 pages 6 figures typo fixed and some arguments adde
Chemically stabilized epitaxial wurtzite-BN thin film
We report on the chemically stabilized epitaxial w-BN thin film grown on
c-plane sapphire by pulsed laser deposition under slow kinetic condition.
Traces of no other allotropes such as cubic (c) or hexagonal (h) BN phases are
present. Sapphire substrate plays a significant role in stabilizing the
metastable w-BN from h-BN target under unusual PLD growth condition involving
low temperature and pressure and is explained based on density functional
theory calculation. The hardness and the elastic modulus of the w-BN film are
37 & 339 GPa, respectively measured by indentation along direction. The
results are extremely promising in advancing the microelectronic and mechanical
tooling industry
Association of adult attachment with delays in accessing specialist care in women with ovarian cancer
OBJECTIVE: Advanced stage at diagnosis and delayed presentation are common in ovarian cancer (OC). The objective of the current study was to explore the association of adult attachment pattern with delays in accessing specialist oncology care in patients with OC. METHODS: A cross-sectional structured interview study of patients with OC presenting to an Indian cancer center was undertaken. Consenting patients completed Experiences of Close Relationships-Relationship Style questionnaire (ECR-RS) and Medical Outcome Survey-Social Support Survey (MOS-SSS). Multivariate linear regression with "time to presentation to cancer specialist" as the dependent variable was undertaken. RESULTS: In all, 132 of 155 (85%) patients with OC who were invited were interviewed. An increased ECR-RS attachment anxiety score (P = .01) and being part of a multigenerational extended household (P = .04) were both independently associated with delay in presentation to a cancer specialist. There was no association between delay in presentation and social support. CONCLUSIONS: Among patients with OC, adult attachment may contribute to delays in presentation. It may be important for the cancer symptom awareness efforts in primary care to include educating physicians on recognizing and interacting with patients with insecure attachment styles. The association of delays in presentation for women with OC living in multigenerational extended households needs more indepth exploration. Supplemental data for this article is available online at https://doi.org/10.1080/07347332.2022.2025510
Immune responses in patients with HIV infection after vaccination with recombinant Hepatitis B virus vaccine
BACKGROUND: Patients with HIV infection are at risk of co-infection with HBV, as the routes of transmission are shared and thus immunization with HBV vaccine could be protective in them. The aim of the present study was to assess the efficacy of recombinant vaccine in treatment-naive HIV positive patients and healthy controls, and to dissect out differences if any, in different limbs of immune response. METHODS: Forty HIV positive patients and 20 HIV negative controls, negative for HBsAg, HBsAbs and HBcAbs were vaccinated with three doses of 40μg and 20μg of vaccine respectively. Patients were divided into high CD4 and low CD4 group based on CD4+ lymphocytes of 200 and < 200/mm3 respectively. Group II consisted of healthy controls. Detection of phenotypic markers was done by flowcytometry. Cytokine estimation was done by sandwich ELISA. HBsAbs were estimated in serum by ELISA. RESULTS: After vaccination, CD(4)+, CD(8)+ and CD(3)+ cells increased significantly in all the groups. There was no increase in NK cell activity in patients with high CD(4)+ lymphocytes and only a marginal increase in patients with low CD(4)+ lymphocytes (170 to 293/mm3) whereas a marked increase was observed in controls (252 to 490/mm3). After vaccination, although an increase in memory cells was observed in HIV positive patients, yet HBsAb levels were significantly lower than controls (P < 0.05) indicating a functional defect of memory cells in HIV/AIDS patients. Basal IFN-γ levels were also significantly lower in HIV/AIDS patients (P < 0.01). Although the levels increased after vaccination, the peak level remained lower than in controls. HBsAb titers were much lower in HIV positive patients compared to controls. (High CD(4)+ group: 8834 mIU/ml, low CD(4)+ group: 462 mIU/ml Vs. Controls: 16,906 mIU/ml). IL-4 and IL-10 were low in patients. CONCLUSION: Despite a double dose in patients, IL-4 and IL-10, which regulate antibody response, were also lower in patients, and this together with low CD(4)+ counts and lack of T help, accounted for low HBsAb levels. Vaccination in patients with CD(4)+ lymphocytes < 50/mm(3) was ineffective. Thus early immunization is advocated in all HIV positive patients at a stage when they are still capable of mounting an adequate immune respons
Quantum discord evolution of three-qubit states under noisy channels
We investigated the dissipative dynamics of quantum discord for correlated
qubits under Markovian environments.
The basic idea in the present scheme is that quantum discord is more general,
and possibly more robust and fundamental, than entanglement. We provide three
initially correlated qubits in pure Greenberger-Horne-Zeilinger (GHZ) or W
state and analyse the time evolution of the quantum discord under various
dissipative channels such as:
Pauli channels , , and , as well as
depolarising channels. Surprisingly, we find that under the action of Pauli
channel , the quantum discord of GHZ state is not affected by
decoherence. For the remaining dissipative channels, the W state is more robust
than the GHZ state against decoherence. Moreover, we compare the dynamics of
entanglement with that of the quantum discord under the conditions in which
disentanglement occurs and show that quantum discord is more robust than
entanglement except for phase flip coupling of the three qubits system to the
environment.Comment: 17 pages, 4 figures, accepted for publication in EPJ
Comparative study of peroxidases from the thyroid and the submaxiliary gland of goat (Capra hiscus)
1. 1. A comparative study of two homogeneous peroxides, isolated previously, from the thyroid and submaxillary gland of the goat has been made. 2. 2. The submaxillary peroxidase has a higher specific activitu and RZ value. Their pH optima differ slightly, but their behavior towards some common inhibitors, molecular weights and Kmappapp for H2O2 are comparable.3. 3. Both the enzymes are identical serologically and behave similarly on a CM-cellulose column. 4. 4. However, on polyacrylamide gel electrophoresis the thyroid peroxidase shows a greater mobility towards the anode at pH 8.3. 5. 5. The enzymes show close similarity in their amino acid composition and can be broken down into approximately similar subunits by SDS gel electrophoresis