34 research outputs found
The Accuracy and Efficiency of the Consensus Forecasts: A Further Application and Extension of the Pooled Approach
In this paper we analyze the macroeconomic forecasts of the Consensus Forecasts for 12 countries over the period from 1996 to 2006 regarding bias and information efficiency. A pooled approach is employed which permits the evaluation of all forecasts for each target variable over 24 horizons simultaneously. It is shown how the pooled approach needs to be adjusted in order to accommodate the forecasting scheme of the Consensus Forecasts. Furthermore, the pooled approach is extended by a sequential test with the purpose of detecting the critical horizon after which the forecast should be regarded as biased. Moreover, heteroscedasticity in the form of year-specific variances of macroeconomic shocks is taken into account. The results show that in the analyzed period which was characterized by pronounced macroeconomic shocks, several countries show biased forecasts, especially with forecasts covering more than 12 months. In addition, information efficiency has to be rejected in almost all cases. --business cycle forecasting,forecast evaluation,Consensus Forecasts
The accuracy and efficiency of the consensus forecasts : a further application and extension of the pooled approach
In this paper we analyze the macroeconomic forecasts of the Consensus Forecasts for 12 countries over the period from 1996 to 2006 regarding bias and information efficiency. A pooled approach is employed which permits the evaluation of all forecasts for each target variable over 24 horizons simultaneously. It is shown how the pooled approach needs to be adjusted in order to accommodate the forecasting scheme of the Consensus Forecasts. Furthermore, the pooled approach is extended by a sequential test with the purpose of detecting the critical horizon after which the forecast should be regarded as biased. Moreover, heteroscedasticity in the form of year-specific variances of macroeconomic shocks is taken into account. The results show that in the analyzed period which was characterized by pronounced macroeconomic shocks, several countries show biased forecasts, especially with forecasts covering more than 12 months. In addition, information efficiency has to be rejected in almost all cases
The PAX Toolkit and its Applications at Tevatron and LHC
At the CHEP03 conference we launched the Physics Analysis eXpert (PAX), a C++
toolkit released for the use in advanced high energy physics (HEP) analyses.
This toolkit allows to define a level of abstraction beyond detector
reconstruction by providing a general, persistent container model for HEP
events. Physics objects such as particles, vertices and collisions can easily
be stored, accessed and manipulated. Bookkeeping of relations between these
objects (like decay trees, vertex and collision separation, etc.) including
deep copies is fully provided by the relation management. Event container and
associated objects represent a uniform interface for algorithms and facilitate
the parallel development and evaluation of different physics interpretations of
individual events. So-called analysis factories, which actively identify and
distinguish different physics processes and study systematic uncertainties, can
easily be realized with the PAX toolkit.
PAX is officially released to experiments at Tevatron and LHC. Being explored
by a growing user community, it is applied in a number of complex physics
analyses, two of which are presented here. We report the successful application
in studies of t-tbar production at the Tevatron and Higgs searches in the
channel t-tbar-Higgs at the LHC and give a short outlook on further
developments
Charge carrier transfer in the gas electron multiplier at low gas gains
Connected to the Linear Collider project TESLA at DESY, studies
on the readout of TPCs based on the GEM-technology are ongoing.
For particle identication via dE/dx - measurement, a good
energy resolution is indispensable, and therefore losses of
primary electrons have to be avoided. It turned out, that in the
GEM transverse diffusion inside or close to the holes is a not
negligible reason for these losses. For Ar-CH4 90:10 and
TPC-like field configurations it was found, that when operated
in normal amplification mode, the Standard Geometry GEM should
not lose primaries, whereas for low gains, also when operated in
magnetic fields up to 5T, a GEM with larger pitch and hole
diameter would be necessary
Expression of survivin detected by immunohistochemistry in the cytoplasm and in the nucleus is associated with prognosis of leiomyosarcoma and synovial sarcoma patients
<p>Abstract</p> <p>Background</p> <p>Survivin, a member of the inhibitor of apoptosis-protein family suppresses apoptosis and regulates cell division. It is strongly overexpressed in the vast majority of cancers. We were interested if survivin detected by immunohistochemistry has prognostic relevance especially for patients of the two soft tissue sarcoma entities leiomyosarcoma and synovial sarcoma.</p> <p>Methods</p> <p>Tumors of leiomyosarcoma (n = 24) and synovial sarcoma patients (n = 26) were investigated for their expression of survivin by immunohistochemistry. Survivin expression was assessed in the cytoplasm and the nucleus of tumor cells using an immunoreactive scoring system (IRS).</p> <p>Results</p> <p>We detected a survivin expression (IRS > 2) in the cytoplasm of 20 leiomyosarcomas and 22 synovial sarcomas and in the nucleus of 12 leiomyosarcomas and 9 synovial sarcomas, respectively. There was no significant difference between leiomyosarcoma and synovial sarcoma samples in their cytoplasmic or nuclear expression of survivin. Next, all sarcoma patients were separated in four groups according to their survivin expression in the cytoplasm and in the nucleus: group 1: negative (IRS 0 to 2); group 2: weak (IRS 3 to 4); group 3: moderate (IRS 6 to 8); group 4: strong (IRS 9 to 12). In a multivariate Cox's regression hazard analysis survivin expression detected in the cytoplasm or in the nucleus was significantly associated with overall survival of patients in group 3 (RR = 5.7; P = 0.004 and RR = 5.7; P = 0.022, respectively) compared to group 2 (reference). Patients whose tumors showed both a moderate/strong expression of survivin in the cytoplasm and a moderate expression of survivin in the nucleus (in both compartments IRS ≥ 6) possessed a 24.8-fold increased risk of tumor-related death (P = 0.003) compared to patients with a weak expression of survivin both in the cytoplasm and in the nucleus.</p> <p>Conclusion</p> <p>Survivin protein expression in the cytoplasma and in the nucleus detected by immunohistochemistry is significantly associated with prognosis of leiomyosarcoma and synovial sarcoma patients.</p