ActiGraph-Measured Breaks in Sedentary Behavior; Are They Real Transitions From Sitting to Standing?

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Spectrum of Charged Black Holes - The Big Fix Mechanism Revisited

Following an earlier suggestion of the authors(gr-qc/9607030), we use some basic properties of Euclidean black hole thermodynamics and the quantum mechanics of systems with periodic phase space coordinate to derive the discrete two-parameter area spectrum of generic charged spherically symmetric black holes in any dimension. For the Reissner-Nordstrom black hole we get $A/4G\hbar=\pi(2n+p+1)$, where the integer p=0,1,2,.. gives the charge spectrum, with $Q=\pm\sqrt{\hbar p}$. The quantity $\pi(2n+1)$, n=0,1,... gives a measure of the excess of the mass/energy over the critical minimum (i.e. extremal) value allowed for a given fixed charge Q. The classical critical bound cannot be saturated due to vacuum fluctuations of the horizon, so that generically extremal black holes do not appear in the physical spectrum. Consistency also requires the black hole charge to be an integer multiple of any fundamental elementary particle charge: $Q= \pm me$, m=0,1,2,.... As a by-product this yields a relation between the fine structure constant and integer parameters of the black hole -- a kind of the Coleman big fix mechanism induced by black holes. In four dimensions, this relationship is $e^2/\hbar=p/m^2$ and requires the fine structure constant to be a rational number. Finally, we prove that the horizon area is an adiabatic invariant, as has been conjectured previously.Comment: 21 pages, Latex. 1 Section, 1 Figure added. To appear in Class. and Quant. Gravit

Generalised dimensions of measures on almost self-affine sets

We establish a generic formula for the generalised q-dimensions of measures supported by almost self-affine sets, for all q>1. These q-dimensions may exhibit phase transitions as q varies. We first consider general measures and then specialise to Bernoulli and Gibbs measures. Our method involves estimating expectations of moment expressions in terms of `multienergy' integrals which we then bound using induction on families of trees

Resposta fenotípica a baixa umidade e estresse hídrico do mutante de milho PAN-1.

RESUMO - A proteína Pangloss 1 (PAN1) participa da formação de estômatos em milho. Plantas mutantes em PAN1 formam estômatos anormais e muito provavelmente têm os processos de fotossíntese e respiração celular comprometidos, o que poderia acarretar em um desenvolvimento anormal das plantas, principalmente quando crescidas em condições de estresse. Nesse trabalho, o objetivo foi estudar o efeito da baixa umidade relativa do ar (UR) e do estresse hídrico no crescimento e desenvolvimento de plantas de milho selvagem e mutante PAN1. A hipótese do trabalho era que as plantas teriam o crescimento e desenvolvimento comprometidos em função da baixa UR e ausência de água. O experimento foi conduzido em uma câmara de crescimento (CC) sob ambiente controlado e foram utilizadas 16 plantas de cada genótipo, seguindo o delineamento inteiramente casualizado. As plantas foram cultivadas em condições ótimas de crescimento até o estádio V4, com exceção da umidade relativa que foi sempre mantida a 20%. Após atingirem V4, as plantas foram submetidas a 4 ciclos de estresse e recuperação, onde a irrigação foi suspensa, sem alteração nas demais variáveis ambientais, até surgimento de sintomas visuais de estresse hídrico. Após esse período, a irrigação foi restabelecida por dois dias, até recuperação. Foram avaliados o estádio de desenvolvimento, número de folhas, altura de planta, comprimento e largura de folha e peso seco. As plantas mutantes apresentaram reduções significativas em várias características mensuradas. Como esperado, a mutação na proteína PAN1 comprometeu o desenvolvimento e crescimento de plantas de milho quando crescidas em condições de estresse.CIIC 2018. Nº 17605. Na publicação: Juliana Yassitepe

The descriptive epidemiology of sitting among US adults, NHANES 2009/2010

Objectives: Using NHANES 2009/2010, to describe the amount of time a representative sample of the U.S. population spends sitting by age, sex, ethnicity, education, and body mass index. Design: Cross-sectional analysis. Methods: Participants (n= 5911, ≥20 years) self-reported demographic variables and the amount of time they spend sitting on a typical day. Body mass index was calculated from measured height and weight. Results: Mean self-reported sitting time was 285. min/day for males and 281. min/day for females. Mexican-Americans reported sitting less than both non-Hispanic Whites and non-Hispanic Blacks (all p <0.0001). Non-Hispanic White males reported sitting more than non-Hispanic Black males, while Non-Hispanic White females reported sitting more than Other Hispanic females (both p <0.0001). No significant differences were found between sexes in any age group. There was a trend for increased sitting time with increasing age for females (p for trend = 0.0045), for all Mexican-American and Hispanic participants and non-Hispanic Black males (all p ≤ 0.006) and with increasing education (p for trend <0.0001). At the College Graduate level, females reported sitting less than males (p < 0.0001). Obese females reported sitting more than normal weight and overweight females (p = 0.0008). There were no significant differences in sitting time by body mass index for males. Conclusions: Self-reported sitting time differed by ethnicity, age group, education and body mass index but there was no overall difference by sex. These results represent the most up to date prevalence of self-reported sitting for the US adult population. Certain groups should be targeted to reduce sitting time, for example those with higher educational attainment and obese females

Stem cell-containing hyaluronic acid-based spongy hydrogels for integrated diabetic wound healing

The detailed pathophysiology of diabetic foot ulcers is yet to be established and improved treatments are still required. We propose a strategy that directs inflammation, neovascularization, and neoinnervation of diabetic wounds. Aiming to potentiate a relevant secretome for nerve regeneration, stem cells were precultured in hyaluronic acid-based spongy hydrogels under neurogenic/standard media before transplantation into diabetic mice full-thickness wounds. Acellular spongy hydrogels and empty wounds were used as controls. Reepithelialization was attained 4 weeks after transplantation independently of the test groups, whereas a thicker and more differentiated epidermis was observed for the cellular spongy hydrogels. A switch from the inflammatory to the proliferative phase of wound healing was revealed for all the experimental groups 2 weeks after injury, but a significantly higher M2(CD163 þ )/M1(CD86 þ ) subtype ratio was observed in the neurogenic preconditioned group that also failed to promote neoinnervation. A higher number of intraepidermal nerve fibers were observed for the unconditioned group probably due to a more controlled transition from the inflammatory to the proliferative phase. Overall, stem cell-containing spongy hydrogels represent a promising approach to enhance diabetic wound healing by positively impacting re-epithelialization and by modulating the inflammatory response to promote a successful neoinnervation.The authors would like to acknowledge Gene2Skin Project (H2020-TWINN2015-692221) and Fundac¸a˜o para a Cieˆncia e Tecnologia for SFRH/BD/ 78025/2011 (LPdS), SFRH/BPD/96611/2013 (MTC), SFRH/BPD/101886/2014 (RPP), SFRH/BPD/101952/2014 (TCS) grants. Moreover, the authors would also like to acknowledge Teresa Oliveira for histology support, Andreia Carvalho for hASCs supply, Luca Gasperini for cell profiler analysis, and Manuela E. L. Lago and Carla M. Abreu for intraepidermal nerve fiber quantification.info:eu-repo/semantics/publishedVersio

Depressive Symptomology Predicts Nighttime Central Systolic Blood Pressure Dipping in Adults

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Area spectrum of the Schwarzschild black hole

We consider a Hamiltonian theory of spherically symmetric vacuum Einstein gravity under Kruskal-like boundary conditions in variables associated with the Einstein-Rosen wormhole throat. The configuration variable in the reduced classical theory is the radius of the throat, in a foliation that is frozen at the left hand side infinity but asymptotically Minkowski at the right hand side infinity, and such that the proper time at the throat agrees with the right hand side Minkowski time. The classical Hamiltonian is numerically equal to the Schwarzschild mass. Within a class of Hamiltonian quantizations, we show that the spectrum of the Hamiltonian operator is discrete and bounded below, and can be made positive definite. The large eigenvalues behave asymptotically as~$\sqrt{2k}$, where $k$ is an integer. The resulting area spectrum agrees with that proposed by Bekenstein and others. Analogous results hold in the presence of a negative cosmological constant and electric charge. The classical input that led to the quantum results is discussed.Comment: 30 pages, REVTeX v3.0. (Minor additions, several added references.

The fermionic contribution to the spectrum of the area operator in nonperturbative quantum gravity

The role of fermionic matter in the spectrum of the area operator is analyzed using the Baez--Krasnov framework for quantum fermions and gravity. The result is that the fermionic contribution to the area of a surface $S$ is equivalent to the contribution of purely gravitational spin network's edges tangent to $S$. Therefore, the spectrum of the area operator is the same as in the pure gravity case.Comment: 10 pages, revtex file. Revised versio

Statistical and dynamical properties of covariant lyapunov vectors in a coupled atmosphere-ocean model—multiscale effects, geometric degeneracy, and error dynamics

We study a simplified coupled atmosphere-ocean model using the formalism of covariant Lyapunov vectors (CLVs), which link physically-based directions of perturbations to growth/decay rates. The model is obtained via a severe truncation of quasi-geostrophic equations for the two fluids, and includes a simple yet physically meaningful representation of their dynamical/thermodynamical coupling. The model has 36 degrees of freedom, and the parameters are chosen so that a chaotic behaviour is observed. There are two positive Lyapunov exponents (LEs), sixteen negative LEs, and eighteen near-zero LEs. The presence of many near-zero LEs results from the vast time-scale separation between the characteristic time scales of the two fluids, and leads to nontrivial error growth properties in the tangent space spanned by the corresponding CLVs, which are geometrically very degenerate. Such CLVs correspond to two different classes of ocean/atmosphere coupled modes. The tangent space spanned by the CLVs corresponding to the positive and negative LEs has, instead, a non-pathological behaviour, and one can construct robust large deviations laws for the finite time LEs, thus providing a universal model for assessing predictability on long to ultra-long scales along such directions. Interestingly, the tangent space of the unstable manifold has substantial projection on both atmospheric and oceanic components. The results show the difficulties in using hyperbolicity as a conceptual framework for multiscale chaotic dynamical systems, whereas the framework of partial hyperbolicity seems better suited, possibly indicating an alternative definition for the chaotic hypothesis. They also suggest the need for an accurate analysis of error dynamics on different time scales and domains and for a careful set-up of assimilation schemes when looking at coupled atmosphere-ocean models