Stochastic inflation in general relativity

\ua9 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article\u27s title, journal citation, and DOI. We provide a formulation of stochastic inflation in full general relativity that goes beyond the slow-roll and separate universe approximations. We show how gauge-invariant Langevin source terms can be obtained for the complete set of Einstein equations in their Arnowitt-Deser-Misner formulation by providing a recipe for coarse-graining the spacetime in any small gauge. These stochastic source terms are defined in terms of the only dynamical scalar degree of freedom in single-field inflation and all depend simply on the first two time derivatives of the coarse-graining window function, on the gauge-invariant mode functions that satisfy the Mukhanov-Sasaki evolution equation, and on the slow-roll parameters. It is shown that this reasoning can also be applied to include gravitons as stochastic sources, thus enabling the study of all relevant degrees of freedom of general relativity for inflation. We validate the efficacy of these Langevin dynamics directly using an example in uniform field gauge, obtaining the stochastic e-fold number in the long wavelength limit without the need for a first-passage-time analysis. As well as investigating the most commonly used gauges in cosmological perturbation theory, we also derive stochastic source terms for the coarse-grained Baumgarte-Shapiro-Shibata-Nakamura formulation of Einstein\u27s equations, which enables a well-posed implementation for 3+1 numerical relativity simulations

Effect of a Glp-1 Mimetic on the Insulin Response to Oral Sugar Testing in Horses

BACKGROUND: Insulin dysregulation (ID) is the most important risk factor for the development of laminitis in horses and therapies to control it are needed. HYPOTHESIS/OBJECTIVES: To assess the effects of a single dose of the synthetic GLP-1 analog exenatide on postprandial insulin dynamics. We hypothesized that exenatide would improve insulin sensitivity and lower postprandial blood insulin concentrations. STUDY DESIGN: Randomized, crossover, experimental study. ANIMALS: Six horses (3 mares, 3 geldings; 2 with normal insulin regulation [NIR] and 4 with mild ID). METHODS: Horses completed both study arms: subcutaneous administration of exenatide (or no treatment) 30 min before an oral sugar test (0.15 ml/kg of Karo Syrup). Blood samples obtained over 240 min were assayed for glucose, insulin, lactate, c-peptide and total GLP-1. The area under the curve (AUC) was calculated using the trapezoidal rule. Insulin sensitivity (S RESULTS: Exenatide resulted in a postprandial decrease of 20% (effect size: 2673 µU·min/ml; 95% CI: 900 - 4446 µU·min/ml; P = 0.003) in AUC of plasma insulin (control; mean AUC insulin: 11,989 µU·min/ml; 95% CI: 9673 - 14,305 µU·min/ml, exenatide; mean AUC insulin: 9316 µU·min/ml; 95% CI: 7430 - 11,202 µU·min/ml). Exenatide resulted in an approximately threefold increase (effect size: 5.56 10 CONCLUSIONS: The decrease in insulin response to carbohydrates was due to an increase in whole-body insulin sensitivity. GLP-1 agonists may have therapeutic potential for ID in horses

Gi- and Gs-coupled GPCRs show different modes of G-protein binding.

More than two decades ago, the activation mechanism for the membrane-bound photoreceptor and prototypical G protein-coupled receptor (GPCR) rhodopsin was uncovered. Upon light-induced changes in ligand-receptor interaction, movement of specific transmembrane helices within the receptor opens a crevice at the cytoplasmic surface, allowing for coupling of heterotrimeric guanine nucleotide-binding proteins (G proteins). The general features of this activation mechanism are conserved across the GPCR superfamily. Nevertheless, GPCRs have selectivity for distinct G-protein family members, but the mechanism of selectivity remains elusive. Structures of GPCRs in complex with the stimulatory G protein, Gs, and an accessory nanobody to stabilize the complex have been reported, providing information on the intermolecular interactions. However, to reveal the structural selectivity filters, it will be necessary to determine GPCR-G protein structures involving other G-protein subtypes. In addition, it is important to obtain structures in the absence of a nanobody that may influence the structure. Here, we present a model for a rhodopsin-G protein complex derived from intermolecular distance constraints between the activated receptor and the inhibitory G protein, Gi, using electron paramagnetic resonance spectroscopy and spin-labeling methodologies. Molecular dynamics simulations demonstrated the overall stability of the modeled complex. In the rhodopsin-Gi complex, Gi engages rhodopsin in a manner distinct from previous GPCR-Gs structures, providing insight into specificity determinants

Separable projection integrals for higher-order correlators of the cosmic microwave sky: Acceleration by factors exceeding 100

© 2016. We present a case study describing efforts to optimise and modernise "Modal", the simulation and analysis pipeline used by the Planck satellite experiment for constraining general non-Gaussian models of the early universe via the bispectrum (or three-point correlator) of the cosmic microwave background radiation. We focus on one particular element of the code: the projection of bispectra from the end of inflation to the spherical shell at decoupling, which defines the CMB we observe today. This code involves a three-dimensional inner product between two functions, one of which requires an integral, on a non-rectangular domain containing a sparse grid. We show that by employing separable methods this calculation can be reduced to a one-dimensional summation plus two integrations, reducing the overall dimensionality from four to three. The introduction of separable functions also solves the issue of the non-rectangular sparse grid. This separable method can become unstable in certain scenarios and so the slower non-separable integral must be calculated instead. We present a discussion of the optimisation of both approaches.We demonstrate significant speed-ups of ≈100×, arising from a combination of algorithmic improvements and architecture-aware optimisations targeted at improving thread and vectorisation behaviour. The resulting MPI/OpenMP hybrid code is capable of executing on clusters containing processors and/or coprocessors, with strong-scaling efficiency of 98.6% on up to 16 nodes. We find that a single coprocessor outperforms two processor sockets by a factor of 1.3× and that running the same code across a combination of both microarchitectures improves performance-per-node by a factor of 3.38×. By making bispectrum calculations competitive with those for the power spectrum (or two-point correlator) we are now able to consider joint analysis for cosmological science exploitation of new data.This research is supported by an STFC consolidated grant ST/L000636/1, and funded in part by the Intel R Parallel Computing Centre program. This work was undertaken on the COSMOS Shared Memory system at DAMTP, University of Cambridge operated on behalf of the STFC DiRAC HPC Facility. This equipment is funded by BIS National E-infrastructure capital grant ST/J005673/1 and STFC grants ST/H008586/1, ST/K00333X/1

Probing inflation with precision bispectra

Calculating the primordial bispectrum predicted by a model of inflation and comparing it to what we see in the sky is very computationally intensive, necessitating layers of approximations and limiting the models which can be constrained. Exploiting the inherent separability of the tree level in-in formalism using expansions in separable basis functions provides a means by which to obviate some of these difficulties. Here, we develop this approach further into a practical and efficient numerical methodology which can be applied to a much wider and more complicated range of bispectrum phenomenology, making an important step forward towards observational pipelines which can directly confront specific models of inflation. We describe a simple augmented Legendre polynomial basis and its advantages, then test the method on single-field inflation models with non-trivial phenomenology, showing that our calculation of these coefficients is fast and accurate to high orders

Vascular photodynamic therapy : a multifactorial approach to inhibit intimal hyperplasia

The Wellman Laboratories of Photomedicine at the Massachusetts General Hospital in Boston is an internationally known institute for the development and application of laser in medicinco Besides fundamental research which investigates the interaction of light with cells and molecules, a great deal of studies arc performed towards clinical application to treat human diseases. For this reason, all known medical specialties are involved in research programmes examining the use of laser for their purposes: from ophtalmologists, using photodynamic therapy to treat choroidal neovascularization, oncologists to photochemically target and remove breast cancer cells from bone marrow, urologist to detect bladder cancer with fluorescence, gastroenterologists to treat Barret's oesophagus to dermatologists removing latloes and treating multiple skin diseases with the laser. The application of laser to treat vascular diseases was started decades ago, but more recently the concept of photodynamic therapy was introduced by the research group of Dr. LaMuraglia to prevent restenosis. As a research fellow in surgery I joined this group in 1994 and our research goal was to better understand how photodynamic therapy affects the vascular wall. The results from these investigations are presented in tllis thesis. The first part gives an outline of the problem of restenosis, the concept of photodynamic therapy and aims of the study. The following chapters describe how photodynamic therapy interacts with biological factors that regulate the vascular healing process. Finally, considerations for possible clinical use are discussed

La responsabilidad civil derivada de las actuaciones de los funcionarios del Registro Público.

El sistema registral panameño tiene como finalidad primordial el dotar de la seguridad jurídica necesaria al tráfico inmobiliario, ofreciendo garantías a quien se proponga a invertir en el mercado de los inmuebles mediante el suministro de información confiable y exacta. Pero el sistema puede fallar, ocasionando daños a los titulares de derechos inscritos o a los terceros que se atienen a las constancias registrales. Para compensar los daños así producidos por una entidad creada precisamente para ofrecer seguridad, el Código Civil panameño establece - inspirándose en este aspecto como en muchos otros concernientes a nuestro sistema registral- en la legislación española, la responsabilidad personal del Registrador, fundada principalmente en la independencia de éste al ejercer su función. No obstante, entre el régimen jurídico a que se encuentra sometido , en términos generales, el Registrador español y el nuestro existen significativas diferencias - aunque en el fondo su labor sea muy similar- que han tornado discutible esa solución, que por otra parte, en la práctica nunca ha funcionado. Además, nuestra más reciente jurisprudencia hace responsable al Estado por la deficiente prestación de servicios públicos, incluso en el caso de los funcionarios judiciales. En un mundo cuya economía se encuentra en un proceso de creciente integración y donde se acentúa la competencia por el capital, es necesario establecer efectivas garantías en el aspecto que nos ocupa. El definir claramente cuáles son las que nuestro país ofrece en este aspecto y cuáles son las que debe ofrecer, constituye el objetivo central del presente trabajo. Para ello analizamos el objetivo, naturaleza jurídica de la función registral y reglamentos operativos del Registro Público panameño, los errores registrales y las normas sobre existentes sobre la responsabilidad civil de los funcionarios registrales frente a las teorías sobre responsabilidad civil estatal, además de los elementos que conforman la responsabilidad civil en el caso específico que nos ocupa. Utilizamos el método deductivo, recurriendo asimismo al histórico y al Derecho Comparado

MEKANISME MENABUNG PADA PRODUK TABUNGAN BERENCANA DI PT. BANK SYARIAH MANDIRI CABANG JAMBI

Laporan akhir ini bertujuan untuk menganalisa Mekanisme Menabung Pada Produk Tabungan Berencana di PT.Bank Syariah Mandiri Cabang Jambi. Yang bertujuan untuk mengetahui bagaimana mekanisme menabung pada produk tabungan berencana yang ada di Bank Syariah Jambi. Laporan akhir ini menggunakan analisis deskriptif dengan metode pengumpulan data melalui observasi, wawancara, dan studi pustaka. Berdasarkan hasil penelitian tentang mekanisme menabung pada produk tabungan berencana di PT. bank syariah mandiri cabang Jambi yang telah penulis lakukan maka, dapat disimpulkan bahwa tabungan berencana ini merupakan tabungan yang diperuntukan untuk semua kalangan. Setiap orang yang memiliki perencanaan keuangan masa depan dapat memanfaatkan produk tabungan berencana ini. Selain itu, tabungan berencana ini juga dapat dijadikan sarana investasi bagi nasabah. Tabungan berencana ini berdasarkan prinsip syariah mudharabah muthlaqah