2,563 research outputs found
Monetary Policy vs. Foreign Exchange Rate: A Statistical Analysis
The purpose of this paper is to examine the economic impact of the Fed’s rate cuts on foreign exchange movements. Using secondary data, the paper estimates the lagged effects of the changes in money supply due to the rate cuts on the foreign exchange rates between the US dollar and the Japanese Yen (/£), and the euro ($/€), respectively. Since the impact of monetary policy tends to have a time lag, as suggested by Hall and Taylor, the study segments the measurements in six months intervals (6 months form the cut, 12 months from the cut, 18 months from the cut and 24 months from the cut). The relationship between the changes in money supply and potential impact on foreign exchange rate movements will be investigated using the Pearson Product-Moment Correlation coefficients (PPMCC) as well as Spearman’s Rank Correlation coefficients (SRCC, the nonparametric alternative to the PPMCC). Then, a hypothesis test will be conducted to determine whether the correlation between the Federal Reserve’s stimulating monetary policy and foreign exchange rate movements is significant
The Effect of North American Free Trade Agreement (NAFTA): Ten Years Later
This paper examines the economic impact of the North American Free Trade Agreement (NAFTA) on international trade among the three member countries – Canada, Mexico and the United States, in the past ten years. Through regression techniques, estimated volume and the predicted trend for exports among the countries are compared with the actual observations. The empirical results indicate that NAFTA did achieve the desired goal of increasing trade among their member countries. The actual trade volume is greater than what the estimated trade volume would have been without NAFTA. Although all the member countries have seen their exports increased, the volumes vary among the three, with Mexico being the largest beneficiary
Multivariate Analysis Of Foreign Direct Investment In China
The purpose of this paper is to empirically examine the foreign direct investment (FDI) in China. China has become an increasingly important hosting economy for FDI and this trend is expected to continue with the country’s entry to the World Trade organization. In this paper, we will review the current literature related to FDI, and use secondary data to employ regression to estimate the trend line of FDI in China. This is followed by factor analysis to examine the variables and factors influencing the FDI in China. We will then perform clustering analysis to look at the regional distribution of FDI in China and finally draw conclusions. 
Team Approach Or Individual Approach: A Statistical Analysis Of The Impact Of Socioeconomic Heterogeneity On Students Preference In Writing Term Papers In Management Courses
The purpose of this paper is to examine students preference in writing term papers in management courses. Specifically, students attitudes and preferences toward the choices, i.e., whether it is written as an individual effort, or as a team effort, are examined. These choices (individual approach, team approach, freedom of choice and indifferent) are then tested against a set of socioeconomic factors to see if there are significant relationships among the variables. The paper reports the empirical findings of the study
Universal expansion of vortex clusters in a dissipative two-dimensional superfluid
A large ensemble of quantum vortices in a superfluid may itself be treated as
a novel kind of fluid that exhibits anomalous hydrodynamics. Here we consider
the dynamics of vortex clusters with thermal friction, and present an analytic
solution that uncovers a new universality class in the out-of-equilibrium
dynamics of dissipative superfluids. We find that the long-time dynamics of the
vorticity distribution is an expanding Rankine vortex (i.e.~top-hat
distribution) independent of initial conditions. This highlights a
fundamentally different decay process to classical fluids, where the Rankine
vortex is forbidden by viscous diffusion. Numerical simulations of large
ensembles of point vortices confirm the universal expansion dynamics, and
further reveal the emergence of a frustrated lattice structure marked by strong
correlations. We present experimental results in a quasi-two-dimensional
Bose-Einstein condensate that are in excellent agreement with the vortex fluid
theory predictions, demonstrating that the signatures of vortex fluid theory
can be observed with as few as vortices. Our theoretical, numerical,
and experimental results establish the validity of the vortex fluid theory for
superfluid systems.Comment: V1: 6 pages, 3 figures in main text. 5 pages, 5 figures in
supplemental material. V2: Updated in response to reviewer comments: Improved
introduction and discussion, additional simulation data provided in
supplemental material
Emergence of off-axis equilibria in a quantum vortex gas
We experimentally study the emergence of high-energy equilibrium states in a
chiral vortex gas of like-circulation vortices realized within a disk-shaped
atomic Bose-Einstein condensate. In contrast to the familiar triangular
Abrikosov lattice, the lowest-energy state of the superfluid in a rotating
frame, we observe the formation of rotating vortex equilibria that are highly
disordered and have significant energy per vortex. Experimental stirring
protocols realize equilibrium states at both positive and negative absolute
temperatures of the vortex gas. At sufficiently high energies the system
exhibits a symmetry breaking transition, resulting in an off-axis equilibrium
phase that no longer shares the symmetry of the container. By initializing
vortices in a non-equilibrium distribution with sufficient energy, relaxation
to equilibrium is observed within experimental timescales and an off-axis
equilibrium state emerges at negative absolute temperature. The observed
equilibria are in close agreement with mean field theory of the microcanonical
ensemble of the vortex gas.Comment: V1: 13 pages, 6 figures, 5 in main tex
Using Interpolation to Estimate System Uncertainty in Gene Expression Experiments
The widespread use of high-throughput experimental assays designed to measure the entire complement of a cell's genes or gene products has led to vast stores of data that are extremely plentiful in terms of the number of items they can measure in a single sample, yet often sparse in the number of samples per experiment due to their high cost. This often leads to datasets where the number of treatment levels or time points sampled is limited, or where there are very small numbers of technical and/or biological replicates. Here we introduce a novel algorithm to quantify the uncertainty in the unmeasured intervals between biological measurements taken across a set of quantitative treatments. The algorithm provides a probabilistic distribution of possible gene expression values within unmeasured intervals, based on a plausible biological constraint. We show how quantification of this uncertainty can be used to guide researchers in further data collection by identifying which samples would likely add the most information to the system under study. Although the context for developing the algorithm was gene expression measurements taken over a time series, the approach can be readily applied to any set of quantitative systems biology measurements taken following quantitative (i.e. non-categorical) treatments. In principle, the method could also be applied to combinations of treatments, in which case it could greatly simplify the task of exploring the large combinatorial space of future possible measurements
Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.
Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form
Androgen Receptor Inhibition Suppresses Anti-Tumor Neutrophil Response Against Bone Metastatic Prostate Cancer via Regulation of TβRI Expression
Bone metastatic disease of prostate cancer (PCa) is incurable and progression in bone is largely dictated by tumor-stromal interactions in the bone microenvironment. We showed previously that bone neutrophils initially inhibit bone metastatic PCa growth yet metastatic PCa becomes resistant to neutrophil response. Further, neutrophils isolated from tumor-bone lost their ability to suppress tumor growth through unknown mechanisms. With this study, our goal was to define the impact of metastatic PCa on neutrophil function throughout tumor progression and to determine the potential of neutrophils as predictive biomarkers of metastatic disease. Using patient peripheral blood polymorphonuclear neutrophils (PMNs), we identified that PCa progression dictates PMN cell surface markers and gene expression, but not cytotoxicity against PCa. Importantly, we also identified a novel phenomenon in which second generation androgen deprivation therapy (ADT) suppresses PMN cytotoxicity via increased transforming growth factor beta receptor I (TβRI). High dose testosterone and genetic or pharmacologic TβRI inhibition rescued androgen receptor-mediated neutrophil suppression and restored neutrophil anti-tumor immune response. These studies highlight the ability to leverage standard-care ADT to generate neutrophil anti-tumor responses against bone metastatic PCa
Transport properties of strongly correlated metals:a dynamical mean-field approach
The temperature dependence of the transport properties of the metallic phase
of a frustrated Hubbard model on the hypercubic lattice at half-filling are
calculated. Dynamical mean-field theory, which maps the Hubbard model onto a
single impurity Anderson model that is solved self-consistently, and becomes
exact in the limit of large dimensionality, is used. As the temperature
increases there is a smooth crossover from coherent Fermi liquid excitations at
low temperatures to incoherent excitations at high temperatures. This crossover
leads to a non-monotonic temperature dependence for the resistance,
thermopower, and Hall coefficient, unlike in conventional metals. The
resistance smoothly increases from a quadratic temperature dependence at low
temperatures to large values which can exceed the Mott-Ioffe-Regel value, hbar
a/e^2 (where "a" is a lattice constant) associated with mean-free paths less
than a lattice constant. Further signatures of the thermal destruction of
quasiparticle excitations are a peak in the thermopower and the absence of a
Drude peak in the optical conductivity. The results presented here are relevant
to a wide range of strongly correlated metals, including transition metal
oxides, strontium ruthenates, and organic metals.Comment: 19 pages, 9 eps figure
- …