171 research outputs found
Fracturing ranked surfaces
Discretized landscapes can be mapped onto ranked surfaces, where every
element (site or bond) has a unique rank associated with its corresponding
relative height. By sequentially allocating these elements according to their
ranks and systematically preventing the occupation of bridges, namely elements
that, if occupied, would provide global connectivity, we disclose that bridges
hide a new tricritical point at an occupation fraction , where
is the percolation threshold of random percolation. For any value of in the
interval , our results show that the set of bridges has a
fractal dimension in two dimensions. In the limit , a self-similar fracture is revealed as a singly connected line
that divides the system in two domains. We then unveil how several seemingly
unrelated physical models tumble into the same universality class and also
present results for higher dimensions
Anyonic interferometry and protected memories in atomic spin lattices
Strongly correlated quantum systems can exhibit exotic behavior called
topological order which is characterized by non-local correlations that depend
on the system topology. Such systems can exhibit remarkable phenomena such as
quasi-particles with anyonic statistics and have been proposed as candidates
for naturally fault-tolerant quantum computation. Despite these remarkable
properties, anyons have never been observed in nature directly. Here we
describe how to unambiguously detect and characterize such states in recently
proposed spin lattice realizations using ultra-cold atoms or molecules trapped
in an optical lattice. We propose an experimentally feasible technique to
access non-local degrees of freedom by performing global operations on trapped
spins mediated by an optical cavity mode. We show how to reliably read and
write topologically protected quantum memory using an atomic or photonic qubit.
Furthermore, our technique can be used to probe statistics and dynamics of
anyonic excitations.Comment: 14 pages, 6 figure
Life experiences of patients who have completed tuberculosis treatment: a qualitative investigation in southeast Brazil
f(R) theories
Over the past decade, f(R) theories have been extensively studied as one of
the simplest modifications to General Relativity. In this article we review
various applications of f(R) theories to cosmology and gravity - such as
inflation, dark energy, local gravity constraints, cosmological perturbations,
and spherically symmetric solutions in weak and strong gravitational
backgrounds. We present a number of ways to distinguish those theories from
General Relativity observationally and experimentally. We also discuss the
extension to other modified gravity theories such as Brans-Dicke theory and
Gauss-Bonnet gravity, and address models that can satisfy both cosmological and
local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in
Relativity, Published version, Comments are welcom
Factors associated with delayed diagnosis of tuberculosis in hospitalized patients in a high TB and HIV burden setting: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>The most essential components of TB control are early diagnosis and adequate treatment. Delay in the diagnosis and treatment of tuberculosis may result in more extensive disease and more complications, increase severity of the disease and is associated with higher risk of mortality. The purpose of this study was to identify factors associated with delayed diagnosis of TB in hospitalized patients.</p> <p>Methods</p> <p>We conducted a cross-sectional study in a general, tertiary care, university-affiliated hospital. Adult patients with TB that were hospitalized were identified retrospectively, and risk factors for delayed diagnosis were collected.</p> <p>Results</p> <p>The median delay until diagnosis was 6 days (IQR: 2-12 days). One hundred and sixty six (54.4%) patients were diagnosed ≤ 6 days, and 139 (45.6%) > 6 days after admission. The main factors associated with diagnostic delay (> 6 days) were extra-pulmonary TB and negative sputum smear.</p> <p>Conclusions</p> <p>Although hospitalization permits a rapid management of the patient and favors a faster diagnosis, we found an unacceptable time delay before the diagnosis of pulmonary TB was made. Future studies should focus on attempt to explain the reasons of diagnostic retard in the patients with the characteristics related to delay in this study.</p
HFE C282Y and H63D in adults with malignancies in a community medical oncology practice
BACKGROUND: We sought to compare frequencies of HFE C282Y and H63D alleles and associated odds ratios (OR) in 100 consecutive unrelated white adults with malignancy to those in 318 controls. METHODS: Data from patients with more than one malignancy were analyzed according to each primary malignancy. For the present study, OR ≥2.0 or ≤0.5 was defined to be increased or decreased, respectively. RESULTS: There were 110 primary malignancies (52 hematologic neoplasms, 58 carcinomas) in the 100 adult patients. Allele frequencies were similar in patients and controls (C282Y: 0.0850 vs. 0.0896, respectively (OR = 0.9); H63D: 0.1400 vs. 0.1447, respectively (OR = 0.9)). Two patients had hemochromatosis and C282Y homozygosity. With C282Y, increased OR occurred in non-Hodgkin lymphoma, myeloproliferative disorders, and adenocarcinoma of prostate (2.0, 2.8, and 3.4, respectively); OR was decreased in myelodysplasia (0.4). With H63D, increased OR occurred in myeloproliferative disorders and adenocarcinomas of breast and prostate (2.4, 2.0, and 2.0, respectively); OR was decreased in non-Hodgkin lymphoma and B-chronic lymphocytic leukemia (0.5 and 0.4, respectively). CONCLUSIONS: In 100 consecutive adults with malignancy evaluated in a community medical oncology practice, frequencies of HFE C282Y or H63D were similar to those in the general population. This suggests that C282Y or H63D is not associated with an overall increase in cancer risk. However, odds ratios computed in the present study suggest that increased (or decreased) risk for developing specific types of malignancy may be associated with the inheritance of HFE C282Y or H63D. Study of more patients with these specific types of malignancies is needed to determine if trends described herein would remain and yield significant differences
Developing agreement on never events in primary care dentistry:an international eDelphi study
Introduction:
Never events (NEs) are a subset of serious patient safety incidents that should not occur if appropriate preventive measures are implemented. Although there is a consensus in medicine, there is no agreement on NEs in dentistry.
Aim:
To identify NEs in primary care dentistry.
Method:
We undertook an electronic Delphi exercise to develop an international agreement on NEs for primary care dentistry.
Results:
We initially identified candidate NEs through a scoping review of the literature and then analysed dentistry-related reports in a national incident reporting system. Next, we invited an international panel of 41 experts to complete two rounds of questionnaires; 32 agreed to participate (78%) and completed the first round and 29/41 (71%) members completed the second round. We provided anonymised controlled feedback between rounds and used a cut-off of 80% agreement to define consensus. Consensus was achieved for 23 out of 42 candidate NEs. These related to routine assessment, and pre-operative, intra-operative and post-operative stages of dental procedures.
Discussion and conclusion:
To our knowledge, this is the first international expert consensus-based approach that has identified NEs for primary care dentistry. We suggest that dental regulators consider these to support quality assessment and governance activities
Bioactivity of plant extracts on the larval and pupal stages of Aedes aegypti (Diptera, Culicidea)
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