Charges and fluxes in Maxwell theory on compact manifolds with boundary

We investigate the charges and fluxes that can occur in higher-order Abelian gauge theories defined on compact space-time manifolds with boundary. The boundary is necessary to supply a destination to the electric lines of force emanating from brane sources, thus allowing non-zero net electric charges, but it also introduces new types of electric and magnetic flux. The resulting structure of currents, charges, and fluxes is studied and expressed in the language of relative homology and de Rham cohomology and the corresponding abelian groups. These can be organised in terms of a pair of exact sequences related by the Poincar\'e-Lefschetz isomorphism and by a weaker flip symmetry exchanging the ends of the sequences. It is shown how all this structure is brought into play by the imposition of the appropriately generalised Maxwell's equations. The requirement that these equations be integrable restricts the world-volume of a permitted brane (assumed closed) to be homologous to a cycle on the boundary of space-time. All electric charges and magnetic fluxes are quantised and satisfy the Dirac quantisation condition. But through some boundary cycles there may be unquantised electric fluxes associated with quantised magnetic fluxes and so dyonic in nature.Comment: 28 pages, plain Te

Brane-world Quantum Gravity

The Arnowitt-Deser-Misner canonical formulation of general relativity is extended to the covariant brane-world theory in arbitrary dimensions. The exclusive probing of the extra dimensions makes a substantial difference, allowing for the construction of a non-constrained canonical theory. The quantum states of the brane-world geometry are defined by the Tomonaga-Schwinger equation, whose integrability conditions are determined by the classical perturbations of submanifolds contained in the Nash's differentiable embedding theorem. In principle, quantum brane-world theory can be tested by current experiments in astrophysics and by near future laboratory experiments at Tev energy. The implications to the black-hole information loss problem, to the accelerating cosmology, and to a quantum mathematical theory of four-sub manifolds are briefly commented.Comment: 14 pages, no figures, JHEP format, to appear in JHEP April 200

Differences between Portuguese and Brazilian Patients with Fibromyalgia Syndrome: Exploring the Associations across Age, Time of Diagnosis, and Fatigue-Related Symptoms

The aim of the study was to explore the differences between Brazilian and Portuguese patients with fibromyalgia (FM) syndrome in their experience of fatigue, and to measure differences in the perception of fatigue as a function of age and duration of the diagnosis. In total, 209 Portuguese women aged between 21 and 75 years (M = 47.44; SD = 10.73) and 429 Brazilian women aged between 18 and 77 years (M = 46.51; SD = 9.24) were recruited to participate in the present study. Participants completed the Multidimensional Daily Diary of Fatigue-Fibromyalgia-17 items (MDF-Fibro-17), a specific tool to measure the level of five components of FM-related fatigue. Results showed greater perception of all the components of fatigue in the Brazilian sample. No significant differences were found related to age and duration of FM diagnosis. The multifaceted nature of FM and cultural differences suggests that individualized treatment programs may be necessary to reduce fatigue-related symptoms in patients with this syndrome.info:eu-repo/semantics/publishedVersio

Diffusion Tensor Imaging in Alzheimer's disease

Attentional control and Information processing speed are central concepts in cognitive psychology and neuropsychology. Functional neuroimaging and neuropsychological assessment have depicted theoretical models considering attention as a complex and non-unitary process. One of its component processes, Attentional set-shifting ability, is commonly assessed using the Trail Making Test (TMT). Performance in the TMT decreases with increasing age in adults, Mild Cognitive Impairment (MCI) and Alzheimer’s Disease (AD). Besides, speed of information processing (SIP) seems to modulate attentional performance. While neural correlates of attentional control have been widely studied, there are few evidences about the neural substrates of SIP in these groups of patients. Different authors have suggested that it could be a property of cerebral white matter, thus, deterioration of the white matter tracts that connect brain regions related to set-shifting may underlie the age-related, MCI and AD decrease in performance. The aim of this study was to study the anatomical dissociation of attentional and speed mechanisms. Diffusion tensor imaging (DTI) provides a unique insight into the cellular integrity of the brain, offering an in vivo view into the microarchitecture of cerebral white matter. At the same time, the study of ageing, characterized by white matter decline, provides the opportunity to study the anatomical substrates speeded or slowed information processing. We hypothesized that FA values would be inversely correlated with time to completion on Parts A and B of the TMT, but not the derived scores B/A and B-A

Understanding the Associations across Fibromyalgia-Related Fatigue, Depression, Anxiety, Self-Esteem Satisfaction with Life and Physical Activity in Portuguese and Brazilian Patients: A Structural Equation Modeling Analysis

Background and Objectives: Fibromyalgia are heterogeneous and differ from patient to patient; however, the most reported are general myalgia and at specific points associated with fatigue and certain psychological adversities. Physical activity can mitigate the effects of the symptoms. However, the associations between fibromyalgia-related fatigue, self-esteem, anxiety, depression, satisfaction with life and physical activity are unclear. Therefore, the aim of the present study was to understand the associations between these symptoms and whether there are differences between these associations across two distinct cultures. Materials and Methods: A total of 473 women aged between 28 and 75 years (M = 49.27; SD ± 8.28) completed five questionnaires about fibromyalgia-related fatigue, physical activity, anxiety, depression, self-esteem, and satisfaction with life. Results: Fibromyalgia-related fatigue was positively associated with depression and anxiety, depression and anxiety were negatively associated with self-esteem, self-esteem was positively associated with satisfaction with life, satisfaction with life was positively associated with physical activity and there were no differences in terms of the perceptions and associations of these variables between Portuguese and Brazilian patients. Conclusions: Our results showed the significant role of associations between these variables and a similarity in the perception and relationship of the variables between the two cultures.info:eu-repo/semantics/publishedVersio

Exploring the Relationship between Fibromyalgia-Related Fatigue, Physical Activity, and Quality of Life

The symptoms of fibromyalgia are varied, including general muscle pain and pain at specific points (also called tender points), excessive fatigue, anxiety, depression, and some psychological problems that can have a negative impact on quality of life. Physical activity is a widely used option by health professionals to alleviate the effects of this syndrome. However, there is no clear information on the possible mediating role of physical activity in the relationship between fibromyalgia-related fatigue and quality of life. Therefore, this study aims to evaluate the relationship between fibromyalgia-related fatigue and quality of life, and to investigate the mediating role of physical activity in patients with this syndrome. Methods: In a cross-sectional study, 237 Portuguese women aged 28 to 75 years (M = 49.12; SD ± 8.87) and 117 Brazilian women aged 20 to 69 years (M = 46.72; SD ± 8.38) were recruited to participate in this study. These patients completed three valid and reliable questionnaires related to the assessment of fibromyalgia-related fatigue (MDF-Fibro-17), physical activity (IPAQ), and quality of life (SF-36). Results: Both samples had scores above the midpoint for all dimensions of fibromyalgia-related fatigue and scores below the midpoint for quality of life. Physical activity had no mediating effect in either sample, as the total indirect effect was not significant. Conclusions: Physical activity does not mediate the relationship between fatigue and quality of life. However, the results also show that the fatigue dimensions associated with fibromyalgia had a negative and significant association with physical and mental health indicators in both samples. Thus, patients with FM with higher scores on fatigue-related symptoms might suffer more from physical and mental health, both of which are related to quality of lifeinfo:eu-repo/semantics/publishedVersio

Seasons and Other Factors Affecting the Quality of Life of Asthmatic Children

[email protected]: To study the effect of seasons on the health-related quality of life (HRQL) of asthmatic children. Methods: Four groups of asthmatic children 7 to 14 years old were recruited by pediatricians during each season of the year. Their HRQL was assessed by means of the Paediatric Asthma Quality of Life Questionnaire (PAQLQ). Other factors surveyed were asthma severity, atopy, medical treatment, immunotherapy, obesity, parental smoking, and anti-allergic measures. Results: The mean (SD) overall PAQLQ score was highest in summer at 6.2 (1.0) and lowest in autumn at 5.5 (1.2). The same trend was found for domains in summer and autumn, respectively: symptoms, 6.2 (1.0) vs 5.4 (1.4); emotions, 6.5 (0.8) vs 6.0 (1.0); and activities, 5.9 (1.4) vs 5.0 (1.5). Factors such as male gender (odds ratio [OR], 0.60; 95% confi dence interval [CI], 0.41–0.87), being on immunotherapy (OR, 0.59; 95% CI, 0.38–0.92), living in an urban environment (OR, 0.56; 0.33–0.93), and residing on the northern coast of Spain along the Bay of Biscay (OR, 0.56; 0.36-0.89) were independent protective factors against having a total PAQLQ score in the lower tertile. Conversely, being recruited in a primary care setting (OR, 1.55; 1.01–2.38) and having more severe asthma were risks for being in the lower tertile. Conclusions: Irrespective of the severity of the disease, season has a significant influence on the HRQL of asthmatic [email protected]

Encuesta seroepidemiológica de pian en la Costa Pacífica colombiana

Yaws has been endemic in the Pacific Coast of Colombia, but the actual prevalence is not known. For this reason we carried out a survey in the communities of this part of the countty where cases had been observed. The active search for cases was based on clinical observations of patients with dermatological disorders, to whom VDRL and FA-ABS tests were administered. The epidemiological survey included 4 intradomiciliary cases for each of the clinical patients detected and also 42 extradomiciliary cases. From a total of 1,830 persons examined, only 6 presented positive results for the VDRL and FTA-ABS tests, which represents a treponema infection prevalence of 0.3%. None of the clinically suspected yaw cases reacted positively to the mentioned tests. These findings permit us to conclude that yaws is not a public health problem in the Pacific Coast of Colombia, and that the sole use of clinical parameters induces to mistaken diagnosis.El pian ha sido endémico en la Costa Pacífica colombiana, pero actualmente su frecuencia real es desconocida, razón por la cual se realizó un estudio en las comunidades de esta zona del país donde se habían conocido casos de pian. Se hizo búsqueda activa de casos clínicos sospechosos a través de examen físico de personas con problemas dermatológicos; a todos ellos se les practicaron exámenes serológicos de VDRL y FTA-ABS. Por cada caso clínico sospechoso de pian, se estudiaron - por clínica y serologia - 4 contactos intradomiciliarios y 42 contactos extradomiciliarios. De las 1.830 personas examinadas, sólo 6 fueron reactivas a las pruebas de VDRL y FTA-ABS, lo cual representa una prevalencia de treponematosis de 0,3%. Ninguna de las pruebas serológicas fue reactiva en los casos clínicos sospechosos de pian. Esto nos lleva a concluir que, en la Costa Pacífica colombiana, el pian no es un problema de salud pública y que se registran como pian otras enfermedades cuando el diagnóstico tiene sólo bases clínicas

Predictive Criteria to Study the Pathogenesis of Malaria-Associated ALI/ARDS in Mice

Malaria-associated acute lung injury/acute respiratory distress syndrome (ALI/ARDS) often results in morbidity and mortality. Murine models to study malaria-associated ALI/ARDS have been described; we still lack a method of distinguishing which mice will develop ALI/ARDS before death. This work aimed to characterize malaria-associated ALI/ARDS in a murine model and to demonstrate the first method to predict whether mice are suffering from ALI/ARDS before death. DBA/2 mice infected with Plasmodium berghei ANKA developing ALI/ARDS or hyperparasitemia (HP) were compared using histopathology, PaO2 measurement, pulmonary X-ray, breathing capacity, lung permeability, and serum vascular endothelial growth factor (VEGF) levels according to either the day of death or the suggested predictive criteria. We proposed a model to predict malaria-associated ALI/ARDS using breathing patterns (enhanced pause and frequency respiration) and parasitemia as predictive criteria from mice whose cause of death was known to retrospectively diagnose the sacrificed mice as likely to die of ALI/ARDS as early as 7 days after infection. Using this method, we showed increased VEGF levels and increased lung permeability in mice predicted to die of ALI/ARDS. This proposed method for accurately identifying mice suffering from ALI/ARDS before death will enable the use of this model to study the pathogenesis of this disease.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Inst Ciencias Biomed, Dept Imunol, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, BR-09972270 Diadema, SP, BrazilUniv São Paulo, Inst Med Trop São Paulo, BR-05403000 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Parasitol, BR-05508000 São Paulo, BrazilUniv São Paulo, Fac Med Vet & Zootecn, Dept Cirurgia, BR-05508270 São Paulo, BrazilUniv São Paulo, Fac Med Vet & Zootecn, Dept Med Vet Prevent & Saude Anim, BR-05508270 São Paulo, BrazilUniv São Paulo, Fac Ciencias Farmaceut, Dept Anal Clin & Toxicol, BR-05508000 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilFAPESP: 2009/53256-7FAPESP: 2009/53889-0CNPq: 306668/2012-2CNPq: 470590/2009-2Web of Scienc

Two interlinked bistable switches govern mitotic control in mammalian cells

Distinct protein phosphorylation levels in interphase and M phase require tight regulation of Cdk1 activity [1, 2]. A bistable switch, based on positive feedback in the Cdk1 activation loop, has been proposed to generate different thresholds for transitions between these cell-cycle states [3, 4, 5]. Recently, the activity of the major Cdk1-counteracting phosphatase, PP2A:B55, has also been found to be bistable due to Greatwall kinase-dependent regulation [6]. However, the interplay of the regulation of Cdk1 and PP2A:B55 in vivo remains unexplored. Here, we combine quantitative cell biology assays with mathematical modeling to explore the interplay of mitotic kinase activation and phosphatase inactivation in human cells. By measuring mitotic entry and exit thresholds using ATP-analog-sensitive Cdk1 mutants, we find evidence that the mitotic switch displays hysteresis and bistability, responding differentially to Cdk1 inhibition in the mitotic and interphase states. Cdk1 activation by Wee1/Cdc25 feedback loops and PP2A:B55 inactivation by Greatwall independently contributes to this hysteretic switch system. However, elimination of both Cdk1 and PP2A:B55 inactivation fully abrogates bistability, suggesting that hysteresis is an emergent property of mutual inhibition between the Cdk1 and PP2A:B55 feedback loops. Our model of the two interlinked feedback systems predicts an intermediate but hidden steady state between interphase and M phase. This could be verified experimentally by Cdk1 inhibition during mitotic entry, supporting the predictive value of our model. Furthermore, we demonstrate that dual inhibition of Wee1 and Gwl kinases causes loss of cell-cycle memory and synthetic lethality, which could be further exploited therapeutically