149 research outputs found
Overconfidence in Investment Decisions: An Experimental Approach
We experimentally test overconfidence in investment decisions by offering participants the possibility to substitute their own for alternative investment choices. Overall, 149 subjects participated in two experiments, one with just one risky asset, the other with two risky assets. Overconfidence increases (i) with the absolute deviation from optimal choices, (ii) with task complexity, and (iii) decreases with uncertainty as indicated by the difference between willingness to pay and to accept.risky decision making, behavioral finance, portfolio choice, experimental economics
Inhibition of diacylglycerol–sensitive TRPC channels by synthetic and natural steroids
TRPC channels are a family of nonselective cation channels that regulate ion homeostasis and intracellular Ca2+ signaling in numerous cell types. Important physiological functions such as vasoregulation, neuronal growth, and pheromone recognition have been assigned to this class of ion channels. Despite their physiological relevance, few selective pharmacological tools are available to study TRPC channel function. We, therefore, screened a selection of pharmacologically active compounds for TRPC modulating activity. We found that the synthetic gestagen norgestimate inhibited diacylglycerol-sensitive TRPC3 and TRPC6 with IC50s of 3–5 µM, while half-maximal inhibition of TRPC5 required significantly higher compound concentrations (>10 µM). Norgestimate blocked TRPC-mediated vasopressin-induced cation currents in A7r5 smooth muscle cells and caused vasorelaxation of isolated rat aorta, indicating that norgestimate could be an interesting tool for the investigation of TRP channel function in native cells and tissues. The steroid hormone progesterone, which is structurally related to norgestimate, also inhibited TRPC channel activity with IC50s ranging from 6 to 18 µM but showed little subtype selectivity. Thus, TRPC channel inhibition by high gestational levels of progesterone may contribute to the physiological decrease of uterine contractility and immunosuppression during pregnancy
Chaos in a double driven dissipative nonlinear oscillator
We propose an anharmonic oscillator driven by two periodic forces of
different frequencies as a new time-dependent model for investigating quantum
dissipative chaos. Our analysis is done in the frame of statistical ensemble of
quantum trajectories in quantum state diffusion approach. Quantum dynamical
manifestation of chaotic behavior, including the emergence of chaos, properties
of strange attractors, and quantum entanglement are studied by numerical
simulation of ensemble averaged Wigner function and von Neumann entropy.Comment: 9 pages, 18 figure
Properties of a Time-Dependent Potassium Current in Pig Atrium: Evidence for a Role of K v
Complementary methods to investigate the development of clogging within a horizontal sub-surface flow tertiary treatment wetland
A combination of experimental methods was applied at a clogged, horizontal subsurface flow (HSSF) municipal wastewater tertiary treatment wetland (TW) in the UK, to quantify the extent of surface and subsurface clogging which had resulted in undesirable surface flow. The three dimensional hydraulic conductivity profile was determined, using a purpose made device which recreates the constant head permeameter test in-situ. The hydrodynamic pathways were investigated by performing dye tracing tests with Rhodamine WT and a novel multi-channel, data-logging, flow through Fluorimeter which allows synchronous measurements to be taken from a matrix of sampling points. Hydraulic conductivity varied in all planes, with the lowest measurement of 0.1 md1 corresponding to the surface layer at the inlet, and the maximum measurement of 1550 md1 located at a 0.4m depth at the outlet. According to dye tracing results, the region where the overland flow ceased received five times the average flow, which then vertically short-circuited below the rhizosphere. The tracer break-through curve obtained from the outlet showed that this preferential flow-path accounted for approximately 80% of the flow overall and arrived 8 h before a distinctly separate secondary flow-path. The overall volumetric efficiencyof the clogged system was 71% and the hydrology was simulated using a dual-path, dead-zone storage model. It is concluded that uneven inlet distribution, continuous surface loading and high rhizosphere resistance is responsible for the clog formation observed in this system. The average inlet hydraulic conductivity was 2 md1, suggesting that current European design guidelines, which predict that the system will reach an equilibrium hydraulic conductivity of 86 md1, do not adequately describe the hydrology of mature systems
Dyson-Schwinger Equations: Density, Temperature and Continuum Strong QCD
Continuum strong QCD is the application of models and continuum quantum field
theory to the study of phenomena in hadronic physics, which includes; e.g., the
spectrum of QCD bound states and their interactions; and the transition to, and
properties of, a quark gluon plasma. We provide a contemporary perspective,
couched primarily in terms of the Dyson-Schwinger equations but also making
comparisons with other approaches and models. Our discourse provides a
practitioners' guide to features of the Dyson-Schwinger equations [such as
confinement and dynamical chiral symmetry breaking] and canvasses
phenomenological applications to light meson and baryon properties in cold,
sparse QCD. These provide the foundation for an extension to hot, dense QCD,
which is probed via the introduction of the intensive thermodynamic variables:
chemical potential and temperature. We describe order parameters whose
evolution signals deconfinement and chiral symmetry restoration, and chronicle
their use in demarcating the quark gluon plasma phase boundary and
characterising the plasma's properties. Hadron traits change in an equilibrated
plasma. We exemplify this and discuss putative signals of the effects. Finally,
since plasma formation is not an equilibrium process, we discuss recent
developments in kinetic theory and its application to describing the evolution
from a relativistic heavy ion collision to an equilibrated quark gluon plasma.Comment: 103 Pages, LaTeX, epsfig. To appear in Progress in Particle and
Nuclear Physics, Vol. 4
Pulmonary Hypertension in Adults with Congenital Heart Disease: Real-World Data from the International COMPERA-CHD Registry
Introduction: Pulmonary hypertension (PH) is a common complication in patients with
congenital heart disease (CHD), aggravating the natural, post-operative, or post-interventional course
of the underlying anomaly. The various CHDs differ substantially in characteristics, functionality, and
clinical outcomes among each other and compared with other diseases with pulmonary hypertension.
Objective: To describe current management strategies and outcomes for adults with PH in relation to
different types of CHD based on real-world data. Methods and results: COMPERA (Comparative,
Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension) is a prospective,
international PH registry comprising, at the time of data analysis, >8200 patients with various forms of
PH. Here, we analyzed a subgroup of 680 patients with PH due to CHD, who were included between
2007 and 2018 in 49 specialized centers for PH and/or CHD located in 11 European countries. At
enrollment, the patients’ median age was 44 years (67% female), and patients had either pre-tricuspid
shunts, post-tricuspid shunts, complex CHD, congenital left heart or aortic disease, or miscellaneous
other types of CHD. Upon inclusion, targeted therapies for pulmonary arterial hypertension (PAH) included endothelin receptor antagonists, PDE-5 inhibitors, prostacyclin analogues, and soluble
guanylate cyclase stimulators. Eighty patients with Eisenmenger syndrome were treatment-naĂŻve.
While at inclusion the primary PAH treatment for the cohort was monotherapy (70% of patients),
with 30% of the patients on combination therapy, after a median observation time of 45.3 months,
the number of patients on combination therapy had increased significantly, to 50%. The use of oral
anticoagulants or antiplatelets was dependent on the underlying diagnosis or comorbidities. In the
entire COMPERA-CHD cohort, after follow-up and receiving targeted PAH therapy (n = 511), 91
patients died over the course of a 5-year follow up. The 5-year Kaplan–Meier survival estimate for
CHD associated PH was significantly better than that for idiopathic PAH (76% vs. 54%; p < 0.001).
Within the CHD associated PH group, survival estimates differed particularly depending on the
underlying diagnosis and treatment status. Conclusions: In COMPERA-CHD, the overall survival of
patients with CHD associated PH was dependent on the underlying diagnosis and treatment status,
but was significantly better as than that for idiopathic PAH. Nevertheless, overall survival of patients
with PAH due to CHD was still markedly reduced compared with survival of patients with other
types of CHD, despite an increasing number of patients on PAH-targeted combination therapy
A randomized multi-center phase II trial of the angiogenesis inhibitor Cilengitide (EMD 121974) and gemcitabine compared with gemcitabine alone in advanced unresectable pancreatic cancer
BACKGROUND: Anti-angiogenic treatment is believed to have at least cystostatic effects in highly vascularized tumours like pancreatic cancer. In this study, the treatment effects of the angiogenesis inhibitor Cilengitide and gemcitabine were compared with gemcitabine alone in patients with advanced unresectable pancreatic cancer. METHODS: A multi-national, open-label, controlled, randomized, parallel-group, phase II pilot study was conducted in 20 centers in 7 countries. Cilengitide was administered at 600 mg/m(2 )twice weekly for 4 weeks per cycle and gemcitabine at 1000 mg/m(2 )for 3 weeks followed by a week of rest per cycle. The planned treatment period was 6 four-week cycles. The primary endpoint of the study was overall survival and the secondary endpoints were progression-free survival (PFS), response rate, quality of life (QoL), effects on biological markers of disease (CA 19.9) and angiogenesis (vascular endothelial growth factor and basic fibroblast growth factor), and safety. An ancillary study investigated the pharmacokinetics of both drugs in a subset of patients. RESULTS: Eighty-nine patients were randomized. The median overall survival was 6.7 months for Cilengitide and gemcitabine and 7.7 months for gemcitabine alone. The median PFS times were 3.6 months and 3.8 months, respectively. The overall response rates were 17% and 14%, and the tumor growth control rates were 54% and 56%, respectively. Changes in the levels of CA 19.9 went in line with the clinical course of the disease, but no apparent relationships were seen with the biological markers of angiogenesis. QoL and safety evaluations were comparable between treatment groups. Pharmacokinetic studies showed no influence of gemcitabine on the pharmacokinetic parameters of Cilengitide and vice versa. CONCLUSION: There were no clinically important differences observed regarding efficacy, safety and QoL between the groups. The observations lay in the range of other clinical studies in this setting. The combination regimen was well tolerated with no adverse effects on the safety, tolerability and pharmacokinetics of either agent
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