879 research outputs found
Real-time prediction with U.K. monetary aggregates in the presence of model uncertainty
A popular account for the demise of the U.K.âs monetary targeting regime in the 1980s blames the fluctuating predictive relationships between broad money and inflation and real output growth. Yet ex post policy analysis based on heavily revised data suggests no fluctuations in the predictive content of money. In this paper, we investigate the predictive relationships for inflation and output growth using both real-time and heavily revised data. We consider a large set of recursively estimated vector autoregressive (VAR) and vector error correction models (VECM). These models differ in terms of lag length and the number of cointegrating relationships. We use Bayesian model averaging (BMA) to demonstrate that real-time monetary policymakers faced considerable model uncertainty. The in-sample predictive content of money fluctuated during the 1980s as a result of data revisions in the presence of model uncertainty. This feature is only apparent with real-time data as heavily revised data obscure these fluctuations. Out-of-sample predictive evaluations rarely suggest that money matters for either inflation or real output. We conclude that both data revisions and model uncertainty contributed to the demise of the U.K.âs monetary targeting regime
A Chiral N=1 Type I Vacuum in Four Dimensions and Its Heterotic Dual
In this paper we consider Type I string theory compactified on a Z_7
orbifold. The model has N=1 supersymmetry, a U(4) \otimes U(4) \otimes U(4)
\otimes SO(8) gauge group, and chiral matter. There are only D9-branes (for
which we discuss tadpole cancellation conditions) in this model corresponding
to a perturbative heterotic description in a certain region of the moduli
space. We construct the heterotic dual, match the perturbative type I and
heterotic tree-level massless spectra via giving certain scalars appropriate
vevs, and point out the crucial role of the perturbative superpotential (on the
heterotic side) for this matching. The relevant couplings in this
superpotential turn out to be non-renormalizable (unlike the Z-orbifold case
discussed in Ref [1], where Yukawa couplings sufficed for duality matching). We
also discuss the role of the anomalous U(1) gauge symmetry present in both type
I and heterotic models. In the perturbative regime we match the (tree-level)
moduli spaces of these models. We point out possible generalizations of the Z_3
and Z_7 cases to include D5-branes which would help in understanding
non-perturbative five-brane dynamics on the heterotic side.Comment: Revtex 3.0, 23 pages, 1 eps figure (to appear in Phys. Rev. D
A Unified Account of the Moral Standing to Blame
Recently, philosophers have turned their attention to the question, not when a given agent is blameworthy for what she does, but when a further agent has the moral standing to blame her for what she does. Philosophers have proposed at least four conditions on having âmoral standingâ:
1. Oneâs blame would not be âhypocriticalâ.
2. One is not oneself âinvolved inâ the target agentâs wrongdoing.
3. One must be warranted in believing that the target is indeed blameworthy for the wrongdoing.
4. The targetâs wrongdoing must some of âoneâs businessâ.
These conditions are often proposed as both conditions on one and the same thing, and as marking fundamentally different ways of âlosing standing.â Here I call these claims into question. First, I claim that conditions (3) and (4) are simply conditions on different things than are conditions (1) and (2). Second, I argue that condition (2) reduces to condition (1): when âinvolvementâ removes someoneâs standing to blame, it does so only by indicating something further about that agent, viz., that he or she lacks commitment to the values that condemn the wrongdoerâs action. The result: after we clarify the nature of the non-hypocrisy condition, we will have a unified account of moral standing to blame. Issues also discussed: whether standing can ever be regained, the relationship between standing and our "moral fragility", the difference between mere inconsistency and hypocrisy, and whether a condition of standing might be derived from deeper facts about the "equality of persons"
Point of View: Whatâs in a name?
Numerous concerns have been raised about the sustainability of the biomedical research enterprise in the United States. Improving the postdoctoral training experience is seen as a priority in addressing these concerns, but even identifying who the postdocs are is made difficult by the multitude of different job titles they can carry. Here, we summarize the detrimental effects that current employment structures have on training, compensation and benefits for postdocs, and argue that academic research institutions should standardize the categorization and treatment of postdocs. We also present brief case studies of two institutions that have addressed these challenges and can provide models for other institutions attempting to enhance their postdoctoral workforces and improve the sustainability of the biomedical research enterprise
tofacitinib treatment is associated with modest and reversible increases in serum lipids in patients with ulcerative colitis
Background & Aims Tofacitinib is an oral, small-molecule Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We analyzed inflammation, lipid concentrations, and incidence rates of major adverse cardiovascular (CV) events (MACEs) in patients who received tofacitinib in worldwide studies. Methods We collected data from 1157 patients who participated in 3 8-week induction studies (1 phase-2 study and 2 phase-3 studies; patients received tofacitinib 10 mg twice daily or placebo), a 52-week phase-3 maintenance study of responders (patients received tofacitinib 5 or 10 mg twice daily or placebo), and an ongoing long-term extension study of patients who did and did not respond to induction or maintenance therapy (patients received tofacitinib 5 or 10 mg twice daily). Lipid concentrations were assessed from induction baseline to week 61 (week 52 of maintenance therapy). We calculated MACE incidence rates (patients with â„1 event per 100 patient-years of exposure) and Reynolds risk score (RRS; a composite score used to determine CV risk) for patients given tofacitinib vs placebo. Results The mean RRS was P Conclusions In an analysis of data from 5 trials of patients with UC who received tofacitinib, we found reversible increases in lipids with treatment and inverse correlations with reduced levels of high-sensitivity C-reactive protein. We did not find clinically meaningful changes in lipid ratios or RRS. MACEs were infrequent and not dose-related. Clinical trial registration Clinicaltrials.gov : A3921063 ( NCT00787202 ); OCTAVE Induction 1 ( NCT01465763 ); OCTAVE Induction 2 ( NCT01458951 ); OCTAVE Sustain ( NCT01458574 ); OCTAVE Open ( NCT01470612
Topology and Signature Changes in Braneworlds
It has been believed that topology and signature change of the universe can
only happen accompanied by singularities, in classical, or instantons, in
quantum, gravity. In this note, we point out however that in the braneworld
context, such an event can be understood as a classical, smooth event. We
supply some explicit examples of such cases, starting from the
Dirac-Born-Infeld action. Topology change of the brane universe can be realised
by allowing self-intersecting branes. Signature change in a braneworld is made
possible in an everywhere Lorentzian bulk spacetime. In our examples, the
boundary of the signature change is a curvature singularity from the brane
point of view, but nevertheless that event can be described in a completely
smooth manner from the bulk point of view.Comment: 26 pages, 8 figures, references and comments are added, minor
revisions and a number of additional footnotes added, error corrected, minor
corrections, to appear in Class. Quant. Gra
Improving the efficacy of cellular therapy by magnetic cell targeting
Poster presented at Biomedical Technology Showcase 2006, Philadelphia, PA. Retrieved 18 Aug 2006 from http://www.biomed.drexel.edu/new04/Content/Biomed_Tech_Showcase/Poster_Presentations/Barbee.pdf.The hot topic of stem cell research has raised hopes for new treatments for a breadth of ailments. As the expectations continue to mount, most related engineering research has been focused around new tools for isolation and propagation of cell lines, with inadequate attention to effective delivery strategies. Invasive or systemic injections come with increased risk and poor efficiency, often wasting a vast majority of the total cellular dosage. We present a method for magnetic targeting of cells in the body with the use of a two-source method of magnetic drug delivery proposed previously in the literature
Floating electrode dielectric barrier discharge plasma in air promoting apoptotic behavior in Melanoma skin cancer cell lines
Plasma Chemistry and Plasma Processing, 27(2): pp. 163-176.Initiation of apoptosis, or programmed cell death, is an important issue in cancer treatment as cancer cells frequently have acquired the ability to block apoptosis and thus are more resistant to chemotherapeutic drugs. Targeted and perhaps selective destruction of cancerous tissue is desirable for many reasons, ranging from the enhancement of or aid to current medical methods to problems currently lacking a solution, i.e. lung cancer. Demonstrated in this publication is the inactivation (killing) of human Melanoma skin cancer cell lines, in vitro, by Floating Electrode Dielectric Barrier Discharge plasma. Not only are these cells shown to be killed immediately by high doses of plasma treatment,but low doses are shown to promote apoptotic behavior as detected by TUNEL staining and subsequent flow cytometry. It is shown that plasma acts on the cells directly and not by âpoisoningâ the solution surrounding the cells, even through a layer of such solution. Potential mechanisms of interaction of plasma with cells are discussed and further steps are proposed to develop an understanding of such systems
- âŠ