447 research outputs found
News-driven business cycles in small open economies
The focus of this paper is on news-driven business cycles in small open economies.
We make two significant contributions. First, we develop a small open economy
model where the presence of financial frictions permits the replication of business
cycle co-movements in response to news shocks. Second, we use VAR analysis to
identify news shocks using data on four advanced small open economies. We find
that expected shocks about the future Total Factor Productivity generate business
cycle co-movements in output, hours, consumption and investment. We also find
that news shocks are associated with countercyclical current account dynamics.
Our findings are robust across a number of alternative identification schemes
Origin of ocean island basalts: A new model based on lead and helium isotope systematics
Free to read at publisher's site. Current models of ocean island basalt (OIB) Pb isotope systematics based on longterm isolation of recycled oceanic crust (with pr without sediment) are not supported by solutions to both terrestrial Pb paradoxes. St follows that the linear arrays of OIB data in Pb isotope diagrams are mixing lines and have no age significance. A new model is presented that takes into account current solutions to both terrestrial Pb paradoxes and that explains combined Pb and He isotope evidence in terms of binary mixing. The key feature of this model is a two-stage evolution: first, long-term separation of depleted mantle from undepleted lowermost lower mantle. Mixing between these two reservoirs results in the wide spread in Pb-207/(204)Pbti` and generally high (but variable) He-3/He-4 ratios that typify enriched mantle 1 (EM1) OIBs. The second stage involves metasomatism of depleted upper mantle by EM1 type, lowermost mantle-derived melts. Evolution in the metasomatized environment is characterized by variable but generally high (Th+U)/(Pb+He) ratio that leads to a rapid increase in Pb-208/Pb-204 and Pb-206/Pb-204 ratios and decrease in He-3/He-4. Mixing between depleted mantle and melts from metasomatized mantle portions reproduces the characteristics of high mu (HIMU) OIBs. The Sr versus Nd isotope array is compatible with binary mixing between depleted mantle and near-chondritic lowermost mantle because of the large variation in Sr/Nd ratios observed in EMI and HIMU OIBs. OIBs contaminated by subcontinental lithospheric mantle (EM2) exhibit more complex isotope systematics that mask their primary geochemical evolution
News-driven business cycles in small open economies
The focus of this paper is on news-driven business cycles in small open economies. We make two significant contributions. First, we develop a small open economy model where the presence of financial frictions permits the replication of business cycle co-movements in response to news shocks. Second, we use VAR analysis to identify news shocks using data on four advanced small open economies. We find that expected shocks about the future Total Factor Productivity generate business cycle co-movements in output, hours, consumption and investment. We also find that news shocks are associated with countercyclical current account dynamics. Our findings are robust across a number of alternative identification schemes
Reconstructing annual inflows to the headwater catchments of the Murray River, Australia, using the Pacific Decadal Oscillation
The Pacific Decadal Oscillation (PDO) is a major forcing of inter-decadal to quasi-centennial variability of the hydroclimatology of the Pacific Basin. Its effects are most pronounced in the extra-tropical regions, while it modulates the El Nino Southern Oscillation (ENSO), the largest forcing of global inter-annual climate variability. PalaeoPDO indices are now available for at least the past 500 years. Here we show that the \u3e500 year PDO index of Shen et al. (2006) is highly correlated with inflows to the headwaters of Australia\u27s longest river system, the Murray-Darling. We then use the PDO to reconstruct annual inflows to the Murray River back to A.D. 1474. These show penta-decadal and quasi-centennial cycles of low inflows and a possible 500 year cycle of much greater inflow variability. Superimposed on this is the likely influence of recent anthropogenic global warming. We believe this may explain the exceptionally low inflows of the past decade, the lowest of the previous 529 years
Modified differentials and basic cohomology for Riemannian foliations
We define a new version of the exterior derivative on the basic forms of a
Riemannian foliation to obtain a new form of basic cohomology that satisfies
Poincar\'e duality in the transversally orientable case. We use this twisted
basic cohomology to show relationships between curvature, tautness, and
vanishing of the basic Euler characteristic and basic signature.Comment: 20 pages, references added, minor corrections mad
An ALMA Survey of HâCO in Protoplanetary Disks
HâCO is one of the most abundant organic molecules in protoplanetary disks and can serve as a precursor to more complex organic chemistry. We present an Atacama Large Millimeter/submillimeter Array survey of HâCO toward 15 disks covering a range of stellar spectral types, stellar ages, and dust continuum morphologies. HâCO is detected toward 13 disks and tentatively detected toward a fourteenth. We find both centrally peaked and centrally depressed emission morphologies, and half of the disks show ring-like structures at or beyond expected CO snowline locations. Together these morphologies suggest that HâCO in disks is commonly produced through both gas-phase and CO-ice-regulated grain-surface chemistry. We extract disk-averaged and azimuthally-averaged HâCO excitation temperatures and column densities for four disks with multiple HâCO line detections. The temperatures are between 20â50 K, with the exception of colder temperatures in the DM Tau disk. These temperatures suggest that HâCO emission in disks generally emerges from the warm molecular layer, with some contributions from the colder midplane. Applying the same HâCO excitation temperatures to all disks in the survey, we find that HâCO column densities span almost three orders of magnitude (~5 Ă 10ÂčÂčâ5 Ă 10Âč⎠cmâ»ÂČ). The column densities appear uncorrelated with disk size and stellar age, but Herbig Ae disks may have less HâCO compared to T Tauri disks, possibly because of less CO freeze-out. More HâCO observations toward Herbig Ae disks are needed to confirm this tentative trend, and to better constrain under which disk conditions HâCO and other oxygen-bearing organics efficiently form during planet formation
Quantum value indefiniteness
The indeterministic outcome of a measurement of an individual quantum is
certified by the impossibility of the simultaneous, definite, deterministic
pre-existence of all conceivable observables from physical conditions of that
quantum alone. We discuss possible interpretations and consequences for quantum
oracles.Comment: 19 pages, 2 tables, 2 figures; contribution to PC0
Hypogammaglobulinemia: A contributing factor to multiple sclerosis fatigue?
OBJECTIVE
Fatigue is one of the most disabling and difficult to treat symptoms of autoimmune diseases and frequently presents in people with multiple sclerosis (PwMS). Hypogammaglobulinemia for immunoglobulin G (IgG) affects approximately 8-25% of PwMS. We performed a retrospective analysis to investigate the association of MS-fatigue and IgG hypogammaglobulinemia.
METHODS
PwMS, treated at Eginition University Hospital Athens or at the University Hospital Bern, were included (n = 134 patients (Bern n = 99; Athens n = 35)). Mann Whitney U-test (MWT), ANOVA test, Chi2 test and multivariable linear regression models were run.
RESULTS
97/134 (72.4%) PwMS reported fatigue. In the multivariable linear regression analysis, IgG serum concentration (-1.6, 95%CI -2.7 - -0.5, p = 0.006), daytime sleepiness (0.8, 95%CI 0.2-1.4, p = 0.009), and a depressive mood (1.1, 95%CI 0.8-1.4, p < 0.001) were significantly associated with fatigue. The impact of IgG serum concentration (-2.9 95%CI -4.7 - -1.1, p = 0.002) remained significant also in the subcohort of PwMS without depressive symptoms or daytime sleepiness.
CONCLUSIONS
We found an association between IgG hypogammaglobulinemia and fatigue in PwMS (Level of Evidence IV), which might be translated to other autoimmune diseases. It bears a potential therapeutic consequence considering IgG supplementation strategies, if our finding can be validated prospectively
Results from the CLIC Test Facility
In order to study the principle of the Compact Linear Collider (CLIC) based on the Two Beam Acceleration (TBA) scheme at high frequency, a CLIC Test Facility (CTF) has been set-up at CERN. After four years of successful running, the experimental programme is now fully completed and all its objectives reached, particularly the generation of a high intensity drive beam with short bunches by a photo-injector, the production of 30 GHz RF power and the acceleration of a probe beam by 30 GHz structures. A summary of the CTF results and their impact on linear collider design is given. This covers 30 GHz high power testing, study of intense, short single bunches; as well as RF-Gun, photocathode and beam diagnostic developments. A second phase of the test facility (CTF2) is presently being installed to demonstrate the feasibility of the TBA scheme by constructing a fully engineered, 10 m long, test section very similar to the CLIC drive and main linacs, producing up to 480 MW of peak RF power at 30 GHz and accelerating the beam up to 320 MeV. The present status of CTF2 is reported
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