15,575 research outputs found
Glassy Dielectric Response in Tb_2NiMnO_6 Double Perovskite with Similarities to a Griffiths Phase
Frequency-dependent and temperature-dependent dielectric measurements are
performed on double perovskite TbNiMnO. The real () and
imaginary () parts of dielectric permittivity show three plateaus
suggesting dielectric relaxation originating from bulk, grain boundaries and
the sample-electrode interfaces respectively. The temperature and frequency
variation of and are successfully simulated by a
circuit model. The complex plane of impedance, -, is simulated using a
series network with a resistor and a constant phase element. Through the
analysis of frequency-dependent dielectric constant using modified-Debye model,
different relaxation regimes are identified. Temperature dependence of dc
conductivity also presents a clear change in slope at, . Interestingly,
compares with the temperature at which an anomaly occurs in the phonon
modes and the Griffiths temperature for this compound. The components and
corresponding to the bulk and the parameter from modified-Debye
fit tend support to this hypothesis. Though these results cannot be interpreted
as magnetoelectric coupling, the relationship between lattice and magnetism is
marked.Comment: Accepted in Europhysics Letter
Oblivion: Mitigating Privacy Leaks by Controlling the Discoverability of Online Information
Search engines are the prevalently used tools to collect information about
individuals on the Internet. Search results typically comprise a variety of
sources that contain personal information -- either intentionally released by
the person herself, or unintentionally leaked or published by third parties,
often with detrimental effects on the individual's privacy. To grant
individuals the ability to regain control over their disseminated personal
information, the European Court of Justice recently ruled that EU citizens have
a right to be forgotten in the sense that indexing systems, must offer them
technical means to request removal of links from search results that point to
sources violating their data protection rights. As of now, these technical
means consist of a web form that requires a user to manually identify all
relevant links upfront and to insert them into the web form, followed by a
manual evaluation by employees of the indexing system to assess if the request
is eligible and lawful.
We propose a universal framework Oblivion to support the automation of the
right to be forgotten in a scalable, provable and privacy-preserving manner.
First, Oblivion enables a user to automatically find and tag her disseminated
personal information using natural language processing and image recognition
techniques and file a request in a privacy-preserving manner. Second, Oblivion
provides indexing systems with an automated and provable eligibility mechanism,
asserting that the author of a request is indeed affected by an online
resource. The automated ligibility proof ensures censorship-resistance so that
only legitimately affected individuals can request the removal of corresponding
links from search results. We have conducted comprehensive evaluations, showing
that Oblivion is capable of handling 278 removal requests per second, and is
hence suitable for large-scale deployment
Magnetotransport in the CeIrIn system: The influence of antiferromagnetic fluctuations
We present an overview of magnetotransport measurements on the heavy-fermion
superconductor CeIrIn. Sensitive measurements of the Hall effect and
magnetoresistance (MR) are used to elucidate the low temperature phase diagram
of this system. The normal-state magnetotransport is highly anomalous, and
experimental signatures of a pseudogap-like precursor state to
superconductivity as well as evidence for two distinct scattering times
governing the Hall effect and the MR are observed. Our observations point out
the influence of antiferromagnetic fluctuations on the magnetotransport in this
class of materials. The implications of these findings, both in the context of
unconventional superconductivity in heavy-fermion systems as well as in
relation to the high temperature superconducting cuprates are discussed
Drug resistance in Plasmodium falciparum from the Chittagong Hill Tracts, Bangladesh.
OBJECTIVE: To assess the efficacy of antimalarial treatment and molecular markers of Plasmodium falciparum resistance in the Chittagong Hill Tracts of Bangladesh. METHODS: A total of 203 patients infected with P. falciparum were treated with quinine 3 days plus sulphadoxine/pyrimethamine (SP) combination therapy, and followed up during a 4-week period. Blood samples collected before treatment were genotyped for parasite mutations related to chloroquine (pfcrt and pfmdr1 genes) or SP resistance (dhfr and dhps). RESULTS: Of 186 patients who completed follow-up, 32 patients (17.2%) failed to clear parasitaemia or became positive again within 28 days after treatment. Recurring parasitaemia was related to age (chi(2) = 4.8, P < 0.05) and parasite rates on admission (t = 3.1, P < 0.01). PCR analysis showed that some of these cases were novel infections. The adjusted recrudescence rate was 12.9% (95% CI 8.1-17.7) overall, and 16.6% (95% CI 3.5-29.7), 15.5% (95% CI 8.3-22.7) and 6.9% (95% CI 0.4-13.4) in three age groups (<5 years, 5-14, > or =15). The majority of infections carried mutations associated with chloroquine resistance: 94% at pfcrt and 70% at pfmdr. Sp-resistant genotypes were also frequent: 99% and 73% of parasites carried two or more mutations at dhfr and dhps, respectively. The frequency of alleles at dhfr, dhps and pfmdr was similar in cases that were successfully treated and those that recrudesced. CONCLUSIONS: The clinical trial showed that quinine 3-days combined to SP is still relatively effective in the Chittagong Hill Tracts. However, if this regimen is continued to be widely used, further development of SP resistance and reduced quinine sensitivity are to be expected. The genotyping results suggest that neither chloroquine nor SP can be considered a reliable treatment for P. falciparum malaria any longer in this area of Bangladesh
Histopathological evaluation of endometrial sampling in perimenopausal women with abnormal uterine bleeding
Background: Abnormal uterine bleeding (AUB) is one of the common symptoms in the gynaecology outpatient department. About one third of women are affected at some time in their lives. The perimenopausal women show significant number of underlying organic pathology. The evaluation of endometrium and/or organ histopathology has the dual advantage of finding the cause of AUB and to rule out endometrial cancer or the potential for cancer in future like endometrial hyperplasia with atypia. The aim of the study was to determine the histopathological pattern of endometrial sampling in perimenopausal women with AUB and to follow them up for a period of six months after the procedure.Methods: The prospective observational study was conducted at the department of obstetrics and gynaecology at Sree Gokulam Medical College and Research Foundation, Venjaramood, Thiruvananthapuram, Kerala, for a period of one year from December 2019 to December 2020. The study was conducted on 116 perimenopausal women 41-52 years who presented with AUB and had undergone endometrial sampling. These ladies were subsequently followed up for six months post procedure to assess the response to medical treatment or the need for any surgical intervention like hysterectomy.Results: A total 39.65% patients had heavy and prolonged menstrual bleeding and 18.16% patients had irregular bleeding. 14.65% patients had prolonged flow, 8.6% had heavy flow, 6.8% had infrequent with prolonged flow, 6% had prolonged, infrequent with heavy bleeding. Non-structural (COEIN) causes contributed to about 60.4% of AUB in perimenopausal women and 39.6% had structural (PALM) causes. 49% cases were secretory endometrium. 29.3% had disordered proliferative endometrium, 4.3% had proliferative endometrium, 5.2% each had polyp or hyperplasia without atypia. 18 (15.5%) cases underwent hysterectomy, 3 patients who had adenocarcinoma underwent staging laparotomy, 2 patients had LNG IUS insertion and 40 patients were on follow up requiring either no treatment and 53 (45.68%) patients were given antifibrinolytics or hormonal therapy.Conclusions: Heavy and prolonged menstrual bleeding was the most common presenting symptom. COEIN contributed to about 60.4% of cases. Evaluation of the endometrium showed that, secretory endometrium was commonest (49%) followed by disordered proliferative endometrium (29.3%). On follow up for six months, 15.5% patients underwent hysterectomy, 2 patients had insertion of levonorgestrel IUD, 45.68% patients had medical management with antifibrinolytics or hormones and were on follow up. The responsibility of gynaecologist in the management of AUB in perimenopausal women is to exclude hyperplasia of endometrium and endometrial cancer
The number of privately treated tuberculosis cases in India: an estimation from drug sales data
Background Understanding the amount of tuberculosis managed by the private sector in India is crucial to understanding the true burden of the disease in the country, and thus globally. In the absence of quality surveillance data on privately treated patients, commercial drug sales data offer an empirical foundation for disease burden estimation. Methods We used a large, nationally representative commercial dataset on sales of 189 anti-tuberculosis products available in India to calculate the amount of anti-tuberculosis treatment in the private sector in 2013–14. We corrected estimates using validation studies that audited prescriptions against tuberculosis diagnosis, and estimated uncertainty using Monte Carlo simulation. To address implications for numbers of patients with tuberculosis, we explored varying assumptions for average duration of tuberculosis treatment and accuracy of private diagnosis. Findings There were 17·793 million patient-months (95% credible interval 16·709 million to 19·841 million) of anti-tuberculosis treatment in the private sector in 2014, twice as many as the public sector. If 40–60% of private-sector tuberculosis diagnoses are correct, and if private-sector tuberculosis treatment lasts on average 2–6 months, this implies that 1·19–5·34 million tuberculosis cases were treated in the private sector in 2014 alone. The midpoint of these ranges yields an estimate of 2·2 million cases, two to three times higher than currently assumed. Interpretation India's private sector is treating an enormous number of patients for tuberculosis, appreciably higher than has been previously recognised. Accordingly, there is a re-doubled need to address this burden and to strengthen surveillance. Tuberculosis burden estimates in India and worldwide require revision
Non-Commutative Corrections to the MIC-Kepler Hamiltonian
Non-commutative corrections to the MIC-Kepler System (i.e. hydrogen atom in
the presence of a magnetic monopole) are computed in Cartesian and parabolic
coordinates. Despite the fact that there is no simple analytic expression for
non-commutative perturbative corrections to the MIC-Kepler spectrum, there is a
term that gives rise to the linear Stark effect which didn't exist in the
standard hydrogen model.Comment: 5 page
Isotropic representation of noncommutative 2D harmonic oscillator
We show that 2D noncommutative harmonic oscillator has an isotropic
representation in terms of commutative coordinates. The noncommutativity in the
new mode, induces energy level splitting, and is equivalent to an external
magnetic field effect. The equivalence of the spectra of the isotropic and
anisotropic representation is traced back to the existence of SU(2) invariance
of the noncommutative model.Comment: 15 pages, RevTex4, no figures; article format, improved version of
the previous paper; new references and aknowledgements adde
Geochemical and isotopic signatures for the identification of seawater intrusion in an alluvial aquifer
Seawater intrusion is one of the alarming processes that reduces the water
quality and imperils the supply of freshwater in coastal aquifers. The region,
north of the Chennai city, India is one such site affected by seawater
intrusion. The objective of this study is to identify the extent of seawater
intruded area by major geochemical and isotopic signatures. A total of 102
groundwater samples were collected and analysed for major and minor ions.
Groundwater samples with electrical conductivity (EC) greater than 5000 μS/cm
and a river mouth sample were analyzed for Oxygen-18 (δ 18O) and Deuterium (δ
2H) isotopes to study their importance in monitoring seawater intrusion. The
molar ratio of geochemical indicators and isotopic signatures suggests an
intrusion up to a distance of 13 km from the sea as on March 2012 and up to
14.7 km during May 2012
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