3,629 research outputs found
Moduli spaces for finite-order jets of Riemannian metrics
We construct the moduli space of r-jets at a point of Riemannian metrics on a
smooth manifold. The construction is closely related to the problem of
classification of jet metrics via differential invariants. The moduli space is
proved to be a differentiable space which admits a finite canonical
stratification into smooth manifolds. A complete study on the stratification of
moduli spaces is carried out for metrics in dimension n=2.Comment: 25 pages, corrected typos, partially changed content with an appendix
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Occupant-Centred Control strategies for Adaptive Facades: A preliminary study of the impact of shortwave solar radiation on thermal comfort
Adaptive facades have the potential to shape resource-efficient and occupant-centred spaces only when their control strategies are tailored to meet transient, local and personal demands. State-of-the-art control algorithms are currently failing to provide occupant thermal satisfaction because the data on occupant response to the thermal environment is not sufficiently granular. This paper presents a preliminary assessment of the use of the adjusted operative temperature, which accounts also for the additional effect of shortwave radiation on occupants, to dynamically devise learning control strategies that meet individual occupant comfort requirements. Shortwave effects of solar radiation on occupant comfort and operative temperature are compared to those considering only longwave radiation and two alternative occupant-centred control strategies are devised and assessed. Lastly, a combined occupant-centred control strategy is also proposed for an open space office
Validation of a Questionnaire to Assess the Perception of Women with Atopic Dermatitis in Family Planning
Introduction: Atopic dermatitis (AD) is a highly frequent chronic inflammatory skin
disease. It is important to know how women with AD approach family planning together with
their disease. The aim of the present research is to develop and validate a questionnaire for women
diagnosed with AD in order to measure their level of desire and gestational information. Materials
and Methods: A multicenter cross-sectional study was conducted. Women between 18 and 45 years
old with mild, moderate, and severe forms of the disease were included and disease-free controls. An
exploratory factorial analysis of the primary components and varimax rotation was used to measure
the validity of the construct. Cronbach’s α was used to measure the reliability of the individual
scales and the global questionnaire. Results: In total, 150 valid questionnaires were included. The
final questionnaire consisted of 23 items that converged on six factors. The six scales had adequate
reliability: “Pregnancy” (Cronbach’s alpha = 0.95), “Conception” (Cronbach’s alpha = 0.93), “Concern-
information” (Cronbach’s alpha = 0.82), “Breastfeeding” (Cronbach’s alpha = 0.81), “Sexual life”
(Cronbach’s alpha = 0.79), and “Family planning” (Cronbach’s alpha = 0.67). The total Cronbach’s
alpha of the questionnaire was 0.94. Discussion: This questionnaire is the first specific measurement
instrument developed for women with AD of childbearing age that has demonstrated adequate levels
of reliability and construct validity. We consider it useful and valuable to study aspects such as family
planning in this patient profile, and that can influence their decision to have offsprin
Clinical Data, Comorbidities, and Mortality of COVID-19 in the State of Guanajuato, Mexico until May 20, 2020
Introduction: In December 2019, cases of pneumonia of unknown cause arose in Wuhan, China. The causative agent was subsequently identified as 2019-nCoV and later called SARS-CoV-2. In Mexico, since January 2020 when the first cases were reported, the spread of the infection has occurred throughout the country. The state of Guanajuato, which is located in the center of the country, has taken isolation measures and closed public places in March 2020. The objective of this study was to analyze the evolution, symptoms, co-morbidities and deaths due to confirmed cases of COVID-19.Methods: An ecological study was designed from the database of confirmed cases of COVID-19 in the state of Guanajuato. Odds ratios and 95% confidence intervals were calculated for symptoms and co-morbidities in deaths of confirmed cases. Logistic regression models were generated adjusting for age group and gender.Results: Among the 838 confirmed cases in the state, cases with dyspnea and cyanosis showed more significant effect on death. Age group and gender had little involvement as confounders. For practically all comorbidities (including diabetes, hypertension, cardiovascular disease, chronic kidney disease, and immunosuppression), there was a significant effect (odds ratio greater than 2) on mortality from COVID-19. Age group showed a confounding effect on comorbidities and death, but not gender.Conclusion: The confirmed cases had more than twice the possibility of having comorbidities, compared with those who did not die
Evidence for dark matter in the inner Milky Way
The ubiquitous presence of dark matter in the universe is today a central
tenet in modern cosmology and astrophysics. Ranging from the smallest galaxies
to the observable universe, the evidence for dark matter is compelling in
dwarfs, spiral galaxies, galaxy clusters as well as at cosmological scales.
However, it has been historically difficult to pin down the dark matter
contribution to the total mass density in the Milky Way, particularly in the
innermost regions of the Galaxy and in the solar neighbourhood. Here we present
an up-to-date compilation of Milky Way rotation curve measurements, and compare
it with state-of-the-art baryonic mass distribution models. We show that
current data strongly disfavour baryons as the sole contribution to the
galactic mass budget, even inside the solar circle. Our findings demonstrate
the existence of dark matter in the inner Galaxy while making no assumptions on
its distribution. We anticipate that this result will compel new
model-independent constraints on the dark matter local density and profile,
thus reducing uncertainties on direct and indirect dark matter searches, and
will shed new light on the structure and evolution of the Galaxy.Comment: First submitted version of letter published in Nature Physics on
Febuary 9, 2015:
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3237.htm
Brain Sci
Mild cognitive impairment (MCI) (amnestic or non-amnestic) has different clinical and neuropsychological characteristics, and its evolution is heterogeneous. Cardiovascular risk factors (CVRF), such as hypertension, diabetes, or dyslipidemia, and the presence of the Apolipoprotein E epsilon4 (ApoE epsilon4) polymorphism have been associated with an increased risk of developing Alzheimer's disease (AD) and other dementias but the relationship is inconsistent worldwide. We aimed to establish the association between the ApoE epsilon4 carrier status and CVRF on MCI subtypes (amnestic and non-amnestic) in Mexican older adults. Cross-sectional study including 137 older adults (n = 63 with normal cognition (NC), n = 24 with amnesic, and n = 50 with non-amnesic MCI). Multinomial logistic regression models were performed in order to determine the association between ApoE epsilon4 polymorphism carrier and CVRF on amnestic and non-amnestic-MCI. ApoE epsilon4 carrier status was present in 28.8% participants. The models showed that ApoE epsilon4 carrier status was not associated neither aMCI nor naMCI condition. The interaction term ApoE epsilon4 x CVRF was not statistically significant for both types of MCI. However, CVRF were associated with both types of MCI and the association remained statistically significant after adjustment by sex, age, and education level. The carrier status of the ApoE genotype does not contribute to this risk
Hypertriglyceridemia Influences the Degree of Postprandial Lipemic Response in Patients with Metabolic Syndrome and Coronary Artery Disease: From the Cordioprev Study
Objective
To determine whether metabolic syndrome traits influence the postprandial lipemia response of coronary patients, and whether this influence depends on the number of MetS criteria.
Materials and Methods
1002 coronary artery disease patients from the CORDIOPREV study were submitted to an oral fat load test meal with 0.7 g fat/kg body weight (12% saturated fatty acids, 10% polyunsaturated fatty acids, 43% monounsaturated fatty acids), 10% protein and 25% carbohydrates. Serial blood test analyzing lipid fractions were drawn at 0, 1, 2, 3 and 4 hours during the postprandial state. Total and incremental area under the curves of the different postprandial parameters were calculated following the trapezoid rule to assess the magnitude of change during the postprandial state
Results
Postprandial lipemia response was directly related to the presence of metabolic syndrome. We found a positive association between the number of metabolic syndrome criteria and the response of postprandial plasma triglycerides (p<0.001), area under the curve of triglycerides (p<0.001) and incremental area under the curve of triglycerides (p<0.001). However, the influence of them on postprandial triglycerides remained statistically significant only in those patients without basal hypertriglyceridemia. Interestingly, in stepwise multiple linear regression analysis with the AUC of triglycerides as the dependent variable, only fasting triglycerides, fasting glucose and waist circumference appeared as significant independent (P<0.05) contributors. The multiple lineal regression (R) was 0.77, and fasting triglycerides showed the greatest effect on AUC of triglycerides with a standardized coefficient of 0.75.
Conclusions
Fasting triglycerides are the major contributors to the postprandial triglycerides levels. MetS influences the postprandial response of lipids in patients with coronary heart disease, particularly in non-hypertriglyceridemic patients
ICTV Virus Taxonomy Profile: Ophioviridae
[EN] The Ophioviridae is a family of filamentous plant viruses, with single-stranded negative, and possibly ambisense, RNA genomes of 11.3-12.5 kb divided into 3-4 segments, each encapsidated separately. Virions are naked filamentous nucleocapsids, forming kinked circles of at least two different contour lengths. The sole genus, Ophiovirus, includes seven species. Four ophioviruses are soil-transmitted and their natural hosts include trees, shrubs, vegetables and bulbous or corm-forming ornamentals, both monocots and dicots. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Ophioviridae, which is available at http://www.ictv.global/report/ophioviridae.Production of this summary, the online chapter and associated resources was funded by a grant from the Wellcome Trust (WT108418AIA).Garcia, M.; Dal Bo, E.; Da Graca, JV.; Gago Zachert, SP.; Hammond, J.; Moreno, P.; Natsuaki, T.... (2017). ICTV Virus Taxonomy Profile: Ophioviridae. Journal of General Virology. 98(6):1161-1162. doi:10.1099/jgv.0.000836S1161116298
Observation of the Baryonic Flavor-Changing Neutral Current Decay Lambda_b -> Lambda mu+ mu-
We report the first observation of the baryonic flavor-changing neutral
current decay Lambda_b -> Lambda mu+ mu- with 24 signal events and a
statistical significance of 5.8 Gaussian standard deviations. This measurement
uses ppbar collisions data sample corresponding to 6.8fb-1 at sqrt{s}=1.96TeV
collected by the CDF II detector at the Tevatron collider. The total and
differential branching ratios for Lambda_b -> Lambda mu+ mu- are measured. We
find B(Lambda_b -> Lambda mu+ mu-) = [1.73+-0.42(stat)+-0.55(syst)] x 10^{-6}.
We also report the first measurement of the differential branching ratio of B_s
-> phi mu+ mu- using 49 signal events. In addition, we report branching ratios
for B+ -> K+ mu+ mu-, B0 -> K0 mu+ mu-, and B -> K*(892) mu+ mu- decays.Comment: 8 pages, 2 figures, 4 tables. Submitted to Phys. Rev. Let
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