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1.
Maturitas ; 184: 107959, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38430617

ABSTRACT

OBJECTIVE: To examine the association between menopause hormone therapy (MHT) and physical performance among women from the Canadian Longitudinal Study on Aging. STUDY DESIGN: Cross-sectional study of 12,506 postmenopausal Canadian women. MAIN OUTCOME MEASURES: Grip strength (kg), gait speed (m/s), timed up and go (s), chair rise (s), and balance (s) were assessed following standard procedures. The association between MHT and physical performance was evaluated using linear regression models adjusted for age, education, study site, smoking, alcohol consumption, body mass index, diabetes, hypertension, and hysterectomy. Sensitivity analyses were conducted according to age at study visit (<65 vs. ≥65 years), body mass index (<25 kg/m2 vs. ≥25 kg/m2), physical activity level (less vs. more active), duration and type of MHT, and time of starting MHT after menopause. RESULTS: Compared with those who never used MHT, prior or current use was associated with better performance on the timed up and go test (ß: -0.19; 95%CI: -0.28; -0.11) and faster gait speed (ß = 0.01, 95%CI = 0.00; 0.02). No association was found for grip strength, balance, and chair rise. Results did not change by body mass index, physical activity, or duration of MHT use. When stratified by age at study visit, the effect remained significant only in among those aged 65 years or more. Starting MHT <5 years after menopause was associated with better physical performance. CONCLUSIONS: MHT was associated with better physical performance in gait speed and timed up and go tests. The cross-sectional design of the study limits causal interpretation. Prospective studies are needed to confirm our results.


Subject(s)
Hand Strength , Physical Functional Performance , Walking Speed , Humans , Female , Cross-Sectional Studies , Middle Aged , Longitudinal Studies , Canada , Aged , Aging/physiology , Menopause , Estrogen Replacement Therapy , Postural Balance , Body Mass Index , Exercise , Postmenopause/physiology
2.
Menopause ; 30(3): 254-259, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36729434

ABSTRACT

OBJECTIVE: To study the association between menopause hormone therapy (MHT) and sarcodynapenia in women from the Canadian Longitudinal Study on Aging. METHODS: We conducted a cross-sectional study of 10,834 eligible postmenopausal women. The exposure was prior or current use of MHT (never, ever). Sarcopenia was defined as an appendicular lean mass less than 5.72 kg/m 2 using dual-energy X-ray absorptiometry, and dynapenia as a grip strength less than 20.4 kg. Sarcodynapenia was defined as the concomitant presence of sarcopenia and dynapenia. Poisson regression analysis produced prevalence ratios (PR) for the associations between MHT use and sarcodynapenia adjusted for age at interview, education, study site, smoking, diabetes, hypertension, and body mass index. Additional analyses were conducted according to duration of MHT (5 years or less, more than 5 years), age categories (45-64 years, 65 years or older), and physical activity level as per the Physical Activity Scale for the Elderly score (less active, more active). RESULTS: Menopause hormone therapy was not associated with sarcodynapenia (PR, 1.10; 95% CI, 0.89-1.35). When subdivided by years of use and physical activity, relative to no MHT use, MHT use for 5 years or less was associated with a higher prevalence of sarcodynapenia among less active women (PR, 1.57; 95% CI, 1.11-2.21) and with a lower prevalence among those more active (PR, 0.60; 95% CI, 0.39-0.92). The use of MHT for more than 5 years was not associated with sarcodynapenia. CONCLUSIONS: Menopause hormone therapy for 5 years or less is associated with a lower prevalence of sarcodynapenia among physically active women and with a higher prevalence of sarcodynapenia in those less active. Strategies to promote an active lifestyle in all postmenopausal women, including MHT users, are needed to attain benefits for musculoskeletal health.


Subject(s)
Menopause , Sarcopenia , Female , Humans , Aged , Middle Aged , Sarcopenia/epidemiology , Longitudinal Studies , Cross-Sectional Studies , Canada , Aging , Hormones , Estrogen Replacement Therapy , Hormone Replacement Therapy
3.
Phys Rev E ; 104(3-1): 034131, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34654147

ABSTRACT

We study a system involving a single quantum degree of freedom per site of the lattice interacting with a few neighbors (up to second neighbors), with the interactions chosen so as to produce frustration. At zero temperature, this system undergoes several quantum phase transitions from both gapped to gapless and gapless to gapless phases, providing a very rich phase structure with disordered, homogeneous, and modulated ordered phases meeting in a quantum Lifshitz point. The gapless phases spontaneously break spatial lattice translations as well as internal symmetries of the form U(1)^{N_{c}}, where N_{c} is the number of independent pitch vectors that arise in the homogeneous and modulated ordered phases. We carry out a detailed analysis of the quantum critical behavior, discussing the mechanism leading to the phase transitions. We also discuss a proper characterization of all the gapless phases as well as the nature of the Goldstone excitations. We study the behavior of the correlation functions and identify regions in the phase diagram where the system exhibits generalized symmetries such as polynomial shift symmetry. This type of symmetry plays an important role in the so-called fractonic phase, which is an exotic form of matter recently discovered.

4.
Sci Rep ; 9(1): 10896, 2019 07 26.
Article in English | MEDLINE | ID: mdl-31350437

ABSTRACT

Genetic analysis of admixed populations raises special concerns with regard to study design and data processing, particularly to avoid population stratification biases. The point mutation responsible for sickle cell anaemia codes for a variant hemoglobin, sickle hemoglobin or HbS, whose presence drives the pathophysiology of disease. Here we propose to explore ancestry and population structure in a genome-wide study with particular emphasis on chromosome 11 in two SCA admixed cohorts obtained from urban populations of Brazil (Pernambuco and São Paulo) and the United States (Pennsylvania). Ancestry inference showed different proportions of European, African and American backgrounds in the composition of our samples. Brazilians were more admixed, had a lower African background (43% vs. 78% on the genomic level and 44% vs. 76% on chromosome 11) and presented a signature of positive selection and Iberian introgression in the HbS region, driving a high differentiation of this locus between the two cohorts. The genetic structures of the SCA cohorts from Brazil and US differ considerably on the genome-wide, chromosome 11 and HbS mutation locus levels.


Subject(s)
Anemia, Sickle Cell/genetics , Chromosomes, Human, Pair 11/genetics , Genetics, Population/methods , Genotype , Hemoglobin, Sickle/genetics , Population Groups , Racial Groups/genetics , Brazil , Cohort Studies , Gene Frequency , Genome , Genome-Wide Association Study , Haplotypes , Humans , United States
5.
Phys Rev Lett ; 121(4): 041601, 2018 Jul 27.
Article in English | MEDLINE | ID: mdl-30095947

ABSTRACT

Bosonization techniques are important nonperturbative tools in quantum field theory. In three dimensions they possess interesting connections to topologically ordered systems and ultimately have driven the observation of an impressive web of dualities. In this work, we use the quantum wires formalism to show how the fermion-boson mapping relating the low-energy regime of the massive Thirring model in three spacetime dimensions with the Maxwell-Chern-Simons model can be obtained from the exact bosonization in two dimensions.

6.
J Clin Pharm Ther ; 42(6): 750-757, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28612497

ABSTRACT

WHAT IS KNOWN AND OBJECTIVE: Malaria is a potentially severe disease, widespread in tropical and subtropical areas. Apart from parasite drug resistance, which receives the largest share of attention, several factors directly influence the response to antimalarial treatment such as incorrect doses, adverse drug events, lack of adherence to treatment, drug quality and drug-drug interactions. Pharmacotherapy follow-up can be used to monitor and improve the effectiveness of treatment, prevent drug-related problems and ensure patient safety. The aim of this study was to describe the results of the implementation of pharmacotherapy follow-up of patients with malaria seen at a reference centre for malaria diagnosis and treatment (CPD-Mal) located in the city of Rio de Janeiro, an area without malaria transmission. METHODS: A descriptive study was conducted from January 2009 to September 2013 at the Instituto Nacional de Infectologia Evandro Chagas (INI) of the Fundação Oswaldo Cruz (Fiocruz). All malaria patients enrolled in the study were treated according to the Brazilian Malaria Therapy Guidelines. Data collected during pharmacotherapy follow-up were recorded in a standardized form. The variables included were age, gender, comorbidities, antimalarials and concomitant medications used, adverse drug reactions (ADR), clinical and parasitological cure times, and treatment outcomes classified as success, recurrence (recrudescence or relapse); and lost to follow-up. The ADR were classified by severity (DAIDS-NIH), organ system affected (WHO-ART) and likelihood to be caused by drugs (Naranjo scale). RESULTS AND DISCUSSION: One hundred thirteen cases of malaria were included. Patients were aged between 13 and 66 years and the majority of them (75.2%) were male. Ninety-four ADR were observed, most classified as mild (85.1%), related to disorders of the gastrointestinal system (63.8%), such as nausea and vomiting, and assessed as "possibly" caused by the antimalarial drugs (91.5%). The majority of clinical (90.9%) and parasitological (87.1%) cure occurred less than 72 hours after treatment initiation. Pharmacotherapy follow-up of malaria treatment by surveillance activities is therefore important regarding information about treatment outcomes as well as patient safety, resulting in better patient care and reducing the chance of relapses. The results underscore its use as a tool for monitoring adherence and drug resistance outside an endemic area. WHAT IS NEW AND CONCLUSION: Pharmacotherapy follow-up should be considered a useful malaria surveillance tool that can be developed by reference centres for comprehensive health care assistance and monitoring of therapeutic resistance.


Subject(s)
Antimalarials/therapeutic use , Malaria/drug therapy , Adolescent , Adult , Antimalarials/adverse effects , Brazil , Child , Drug Resistance , Drug-Related Side Effects and Adverse Reactions/etiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Recurrence , Travel Medicine/methods , Treatment Outcome , Young Adult
7.
Article in English | MEDLINE | ID: mdl-25768473

ABSTRACT

We construct a quantum system of spherical spins with a continuous local symmetry. The model is exactly soluble in the thermodynamic limit and exhibits a number of interesting properties. We show that the local symmetry is spontaneously broken at finite as well as zero temperatures, implying the existence of classical and quantum phase transitions with a nontrivial critical behavior. The dynamical generation of gauge fields and the equivalence with the CP((N-1)) model in the limit N→∞ are investigated. The dynamical generation of gauge fields is a consequence of the restoration of the local symmetry.

8.
J Mech Behav Biomed Mater ; 14: 19-28, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22963743

ABSTRACT

We considered various stability issues related to biomechanical models of the spine, taking as our point of departure the scalar quantities proposed in Howarth et al. (2004). We discussed their significance and applicability by considering some mechanical toy models. In particular, we analysed the relevance of the behaviour of some of these measurements, namely, the determinant of the Hessian matrix and other quantities containing information of a similar spectral nature, and the role they may play in this type of studies. We showed that although in some cases these markers contain information about the load acting on the subject, this information may also be masked and not be detectable from these indexes. These models also allowed us to see how a system with these characteristics may become highly sensitive even to small load changes, and prompted us to put forward the hypothesis that trying to preserve stability at all costs might, under some circumstances, be an actual cause for system damage.


Subject(s)
Mechanical Phenomena , Models, Statistical , Spine/physiology , Biomechanical Phenomena , Models, Biological
9.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(6 Pt 1): 061109, 2012 Jun.
Article in English | MEDLINE | ID: mdl-23005053

ABSTRACT

In this work, we present a supersymmetric extension of the quantum spherical model, both in components and also in the superspace formalisms. We find the solution for short- and long-range interactions through the imaginary time formalism path integral approach. The existence of critical points (classical and quantum) is analyzed and the corresponding critical dimensions are determined.


Subject(s)
Models, Chemical , Quantum Theory , Computer Simulation
10.
An Acad Bras Cienc ; 82(4): 1085-94, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21152778

ABSTRACT

The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55% of Brazilian beef production. Previous investigations have shown that about 70-80% of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1) a surface horizon (0.0-0.2 m) in order to evaluate its fertility and acidity status for pasture, and (2) a subsurface horizon (0.6-0.8 m), used for classification. Most of soils had levels of nutrients below the reference values for adequate pasture development. Whatever the texture, about 90% of soils had low or very low availability of phosphorus. Only 7 to 14% of soils had low pH, high exchangeable aluminum, and aluminum saturation above the critical acidity level. Except for nitrogen, no significant difference was found between Latossolos Vermelhos and Latossolos Vermelho-Amarelos.


Subject(s)
Agriculture , Chemical Phenomena , Environmental Monitoring/methods , Soil/chemistry , Animals , Brazil , Cattle , Fertilizers
11.
An. acad. bras. ciênc ; 82(4): 1085-1094, Dec. 2010. graf, mapas, tab
Article in English | LILACS | ID: lil-567814

ABSTRACT

The Cerrado region, with over 50 million hectares of cultivated pasture, provides 55 percent of Brazilian beef production. Previous investigations have shown that about 70-80 percent of this pasture is affected by some kind of degradation, leading to low productivity. However, until now, few surveys have been carried out on a regional scale. The aim of the present work is both to assess the fertility and acidity levels of Cerrado soils under pasture and compare the variability of the soils characteristics on a regional scale. Two soil depths were sampled in different places within the studied area: (1) a surface horizon (0.0-0.2 m) in order to evaluate its fertility and acidity status for pasture, and (2) a subsurface horizon (0.6-0.8 m), used for classification. Most of soils had levels of nutrients below the reference values for adequate pasture development. Whatever the texture, about 90 percent of soils had low or very low availability of phosphorus. Only 7 to 14 percent of soils had low pH, high exchangeable aluminum, and aluminum saturation above the critical acidity level. Except for nitrogen, no significant difference was found between Latossolos Vermelhos and Latossolos Vermelho-Amarelos.


A região do Cerrado, com 50 milhões de hectares de pastagens cultivadas, responde por 55 por cento da carne bovina produzida no Brasil. Há estimativas indicando que entre 70 e 80 por cento destas pastagens apresentam algum grau de degradação, o que leva a baixa produtividade. No entanto, até o presente, poucos trabalhos foram desenvolvidos em escala regional. O objetivo deste trabalho foi avaliar a fertilidade e a acidez de Latossolos sob pastagens na região do Cerrado e comparar a variabilidade das características dos solos em escala regional. A amostragem foi realizada em duas profundidades, superficial (0,0-0,2 m) para avaliação da fertilidade e acidez e subsuperficial (0,60,8 m), utilizada para classificar os solos. A maioria dos solos apresentou teores de nutrientes abaixo do recomendado para o adequado desenvolviento das pastagens. Independentemente da textura, aproximadamente 90 por cento dos solos apresentaram baixa ou muito baixa disponibilidade de P. Apenas 7-14 por cento dos solos apresentaram baixo pH, alta saturação por Al e acidez acima do nível crítico. Exceto para o N, não houve diferença significativa nos níveis de fertilidade e acidez entre os Latossolos Vermelhos e os Latossolos Vermelho-Amarelos.


Subject(s)
Animals , Cattle , Agriculture , Chemical Phenomena , Environmental Monitoring/methods , Soil/chemistry , Brazil , Fertilizers
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