Global economy dynamics? Panel data approach to spillover effects

Over the past year, there has been considerable debate about how the slowing of the United States and other major developed economies affects output growth across the world. The main purpose of this paper is to establish relevant conclusions on how the U.S., Euro Area and Japan gross domestic product growth affect international business cycle fluctuations, with the objective of identifying the main factors that influence spillovers into other countries. Using panel data regression, we conclude that output growth in the U.S. and Euro area are significant in explaining output growth across countries. Depending on the specifications, trade linkages play a significant role while financial linkages with respect to the three regions does not (except in one particular specification). There are signs of potential omitted variable bias in some regression indicating that some relevant variables have not been taken into account. There is also clear evidence of a structural change in the transmission mechanism of shocks after 1985 – since when shocks have become more country-specific.Output Growth, Trade and Financial Linkages, Structural Break, Cross- Section Panel Data.

Stressed-Oxidation Lifetime of Different SiC Fiber, CVI Matrix SiC Minicomposites in Air

The stressed-oxidation lifetime properties of several minicomposites composed of single fiber tows with a CVI SiC matrix were compared. The minicomposites were made up of Nicalon(Tm) and Hi-Nicalon(Tm) SiC fibers with carbon or BN interphases. Constant load stress-rupture tests were performed between 600 and 13000 C in air for all of the minicomposite systems. Cyclic load testing was performed on the Hi-Nicalon minicomposite systems. The factors controlling the different lifetime behaviors: fiber rupture properties, interphase oxidation, fiber degradation, and fiber-matrix bonding, are discussed in light of different minicomposite constituents. All of the systems were subject to intermediate temperature embrittlement. The Hi-Nicalon fiber, BN interphase system, performed the best for constant load conditions. For cyclic load conditions, both the BN- interphase and C-interphase minicomposites displayed poor, but different failure behavior

Accurate masses for dispersion-supported galaxies

We derive an accurate mass estimator for dispersion-supported stellar systems and demonstrate its validity by analyzing resolved line-of-sight velocity data for globular clusters, dwarf galaxies, and elliptical galaxies. Specifically, by manipulating the spherical Jeans equation we show that the dynamical mass enclosed within the 3D deprojected half-light radius r_1/2 can be determined with only mild assumptions about the spatial variation of the stellar velocity dispersion anisotropy. We find M_1/2 = 3 \sigma_los^2 r_1/2 / G ~ 4 \sigma_los^2 R_eff / G, where \sigma_los^2 is the luminosity-weighted square of the line-of-sight velocity dispersion and R_eff is the 2D projected half-light radius. While deceptively familiar in form, this formula is not the virial theorem, which cannot be used to determine accurate masses unless the radial profile of the total mass is known a priori. We utilize this finding to show that all of the Milky Way dwarf spheroidal galaxies (MW dSphs) are consistent with having formed within a halo of mass approximately 3 x 10^9 M_sun in Lambda CDM cosmology. The faintest MW dSphs seem to have formed in dark matter halos that are at least as massive as those of the brightest MW dSphs, despite the almost five orders of magnitude spread in luminosity. We expand our analysis to the full range of observed dispersion-supported stellar systems and examine their I-band mass-to-light ratios (M/L). The M/L vs. M_1/2 relation for dispersion-supported galaxies follows a U-shape, with a broad minimum near M/L ~ 3 that spans dwarf elliptical galaxies to normal ellipticals, a steep rise to M/L ~ 3,200 for ultra-faint dSphs, and a more shallow rise to M/L ~ 800 for galaxy cluster spheroids.Comment: 20 pages, 13 figures. Accepted to MNRAS on March 27th, 201

Amateur Astronomy Research Telescope

The ERAU Amateur Astronomy Club Research Team is designing and building an amateur research telescope. The primary goal is high portability and compactness, with no compromise of optical quality. The team began with a set of mirrors pre-owned by the Amateur Astronomy Club, and will be constructing the telescope frame from medium density particle board. In the traditional style of John Dobson, the secondary mirror will be mounted on a truss system. This will reduce the weight and size of the telescope during transportation, as it can be disassembled and transported in a very small area. The primary purpose of the telescope is to observe and catalog messier objects in the night sky. After completion of the Messier Catalog, it shall be presented before physics faculty of ERAU

Two-Dimensional Reduced Theory and General Static Solution for Uncharged Black p-Branes

We derive a two-dimensional effective dilaton - gravity - matter action that describes the dynamics of an uncharged black p-brane in N dimensions. We show that this effective theory is completely integrable in the static sector and establish its general static solution. The solution includes, as a particular case, the boost symmetric p-brane solution investigated in hep-th/9510202 .Comment: 11 pages, plain LaTex, accepted for publication in Phys. Lett.

Augmenting Control over Exploration Space in Molecular Dynamics Simulators to Streamline De Novo Analysis through Generative Control Policies

This study introduces the P5 model - a foundational method that utilizes reinforcement learning (RL) to augment control, effectiveness, and scalability in molecular dynamics simulations (MD). Our innovative strategy optimizes the sampling of target polymer chain conformations, marking an efficiency improvement of over 37.1%. The RL-induced control policies function as an inductive bias, modulating Brownian forces to steer the system towards the preferred state, thereby expanding the exploration of the configuration space beyond what traditional MD allows. This broadened exploration generates a more varied set of conformations and targets specific properties, a feature pivotal for progress in polymer development, drug discovery, and material design. Our technique offers significant advantages when investigating new systems with limited prior knowledge, opening up new methodologies for tackling complex simulation problems with generative techniques.Comment: ICML 2023 Workshop on Structured Probabilistic Inference (SPIGM) and Generative Modeling, of the International Conference of Machine Learning (ICML

Obscure Overt Gastrointestinal Bleeding Due To Isolated Small Bowel Angiomatosis

Isolated small bowel angiomatosis is a rare entity with a distinctive endoscopic appearance. A multidisciplinary approach is often required to diagnose and treat these complex lesions. We present 2 cases of isolated small bowel angiomatosis, and illustrate the endoscopic findings that may guide similar diagnoses

Trim71 cooperates with microRNAs to repress Cdkn1a expression and promote embryonic stem cell proliferation

Pluripotent embryonic stem cells (ESCs) have a shortened cell cycle that enables their rapid proliferation. The ESC-specific miR-290 and miR-302 microRNA families promote proliferation whereas let-7 microRNAs inhibit self-renewal and promote cell differentiation. Lin28 suppresses let-7 expression in ESCs. Here, to gain further insight into mechanisms controlling ESC self-renewal we explore the molecular and cellular role of the let-7 target Trim71 (mLin41). We show that Trim71 associates with Argonaute2 (Ago2) and microRNAs and represses expression of Cdkn1a, a cyclin-dependent kinase inhibitor that negatively regulates the G1–S transition. We identify protein domains required for Trim71 association with Ago2, localization to P-bodies, and for repression of reporter mRNAs. Trim71 knockdown prolongs the G1 phase of the cell cycle and slows ESC proliferation, a phenotype that was rescued by depletion of Cdkn1a. Thus, we demonstrate Trim71 is a factor that facilitates the G1–S transition to promote rapid ESC self-renewal