376 research outputs found
The Problem of Time and Quantum Black Holes
We discuss the derivation of the so-called semi-classical equations for both
mini-superspace and dilaton gravity. We find that there is no systematic
derivation of a semi-classical theory in which quantum mechanics is formulated
in a space-time that is a solution of Einstein's equation, with the expectation
value of the matter stress tensor on the right-hand side. The issues involved
are related to the well-known problems associated with the interpretation of
the Wheeler-deWitt equation in quantum gravity, including the problem of time.
We explore the de Broglie-Bohm interpretation of quantum mechanics (and field
theory) as a way of spontaneously breaking general covariance, and thereby
giving meaning to the equations that many authors have been using to analyze
black hole evaporation. We comment on the implications for the ``information
loss" problem.Comment: 30 pages, COLO-HEP-33
Characterizing the Near-infrared Spectra of Flares from TRAPPIST-1 During JWST Transit Spectroscopy Observations
We present the first analysis of JWST near-infrared spectroscopy of stellar
flares from TRAPPIST-1 during transits of rocky exoplanets. Four flares were
observed from 0.6--2.8 m with NIRISS and 0.6--3.5 m with NIRSpec
during transits of TRAPPIST-1b, f, and g. We discover P and Br
line emission and characterize flare continuum at wavelengths from 1--3.5
m for the first time. Observed lines include H,
P-P, Br, He I 0.7062m, two Ca II
infrared triplet (IRT) lines, and the He I IRT. We observe a reversed Paschen
decrement from P-P alongside changes in the light curve shapes
of these lines. The continuum of all four flares is well-described by blackbody
emission with an effective temperature below 5300 K, lower than temperatures
typically observed at optical wavelengths. The 0.6--1 m spectra were
convolved with the TESS response, enabling us to measure the flare rate of
TRAPPIST-1 in the TESS bandpass. We find flares of 10 erg large enough
to impact transit spectra occur at a rate of 3.6 flare
d, 10 higher than previous predictions from K2. We measure
the amount of flare contamination at 2 m for the TRAPPIST-1b and f
transits to be 500450 and 2100400 ppm, respectively. We find up to
80% of flare contamination can be removed, with mitigation most effective from
1.0--2.4 m. These results suggest transits affected by flares may still be
useful for atmospheric characterization efforts.Comment: 29 pages, 17 figures, 3 tables, accepted to The Astrophysical Journa
Epigenetic change in e-cardherin and COX-2 to predict chronic periodontitis
<p>Abstract</p> <p>Background</p> <p>DNA methylation of certain genes frequently occurs in neoplastic cells. Although the cause remains unknown, many genes have been identified with such atypical methylation in neoplastic cells. The hypermethylation of E-Cadherin and Cyclooxygenase 2 (COX-2) in chronic inflammation such as chronic periodontitis may demonstrate mild lesion/mutation epigenetic level. This study compares the hypermethylation status of E-Cadherin and COX-2 genes which are often found in breast cancer patients with that in chronic periodontitis.</p> <p>Methods</p> <p>Total DNA was extracted from the blood samples of 108 systemically healthy non-periodontitis subjects, and the gingival tissues and blood samples of 110 chronic periodontitis patient as well as neoplastic tissues of 106 breast cancer patients. Methylation-specific PCR for E-Cadherin and COX-2 was performed on these samples and the PCR products were analyzed on 2% agarose gel.</p> <p>Results</p> <p>Hypermethylation of E-Cadherin and COX-2 was observed in 38% and 35% of the breast cancer samples, respectively. In chronic periodontitis patients the detection rate was 25% and 19% respectively, and none was found in the systemically healthy non-periodontitis control subjects. The hypermethylation status was shown to be correlated among the three groups with statistical significance (p < 0.0001). The methylation of CpG islands in E-Cadherin and COX-2 genes in periodontitis patients occurs more frequently in periodontitis patients than in the control subjects, but occurs less frequently than in the breast cancer patients.</p> <p>Conclusions</p> <p>This set of data shows that the epigenetic change in E-Cadherin and Cyclooxygenase-2 is associated with chronic periodontitis. The epigenetic changes presented in chronic inflammation patients might demonstrate an irreversible destruction in the tissues or organs similar to the effects of cancer. Chronic periodontitis to some extent might be associated with DNA hypermethylation which is related to cancer risk factors.</p
ARIA 2016:Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle
The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma and rhinitis and (3) to develop guidelines with all stakeholders that could be used globally for all countries and populations. ARIA-disseminated and implemented in over 70 countries globally-is now focusing on the implementation of emerging technologies for individualized and predictive medicine. MASK [MACVIA (Contre les Maladies Chroniques pour un Vieillissement Actif)-ARIA Sentinel NetworK] uses mobile technology to develop care pathways for the management of rhinitis and asthma by a multi-disciplinary group and by patients themselves. An app (Android and iOS) is available in 20 countries and 15 languages. It uses a visual analogue scale to assess symptom control and work productivity as well as a clinical decision support system. It is associated with an inter-operable tablet for physicians and other health care professionals. The scaling up strategy uses the recommendations of the European Innovation Partnership on Active and Healthy Ageing. The aim of the novel ARIA approach is to provide an active and healthy life to rhinitis sufferers, whatever their age, sex or socio-economic status, in order to reduce health and social inequalities incurred by the disease
Geolocation with respect to persona privacy for the Allergy Diary app - a MASK study
Background: Collecting data on the localization of users is a key issue for the MASK (Mobile Airways Sentinel network: the Allergy Diary) App. Data anonymization is a method of sanitization for privacy. The European Commission's Article 29 Working Party stated that geolocation information is personal data. To assess geolocation using the MASK method and to compare two anonymization methods in the MASK database to find an optimal privacy method. Methods: Geolocation was studied for all people who used the Allergy Diary App from December 2015 to November 2017 and who reported medical outcomes. Two different anonymization methods have been evaluated: Noise addition (randomization) and k-anonymity (generalization). Results: Ninety-three thousand one hundred and sixteen days of VAS were collected from 8535 users and 54,500 (58. 5%) were geolocalized, corresponding to 5428 users. Noise addition was found to be less accurate than k-anonymity using MASK data to protect the users' life privacy. Discussion: k-anonymity is an acceptable method for the anonymization of MASK data and results can be used for other databases.Peer reviewe
Is diet partly responsible for differences in COVID-19 death rates between and within countries?
Correction: Volume: 10 Issue: 1 Article Number: 44 DOI: 10.1186/s13601-020-00351-w Published: OCT 26 2020Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.Peer reviewe
Allergic Rhinitis and its Impact on Asthma (ARIA) Phase 4 (2018) : Change management in allergic rhinitis and asthma multimorbidity using mobile technology
Allergic Rhinitis and its Impact on Asthma (ARIA) has evolved from a guideline by using the best approach to integrated care pathways using mobile technology in patients with allergic rhinitis (AR) and asthma multimorbidity. The proposed next phase of ARIA is change management, with the aim of providing an active and healthy life to patients with rhinitis and to those with asthma multimorbidity across the lifecycle irrespective of their sex or socioeconomic status to reduce health and social inequities incurred by the disease. ARIA has followed the 8-step model of Kotter to assess and implement the effect of rhinitis on asthma multimorbidity and to propose multimorbid guidelines. A second change management strategy is proposed by ARIA Phase 4 to increase self-medication and shared decision making in rhinitis and asthma multimorbidity. An innovation of ARIA has been the development and validation of information technology evidence-based tools (Mobile Airways Sentinel Network [MASK]) that can inform patient decisions on the basis of a self-care plan proposed by the health care professional.Peer reviewe
- …