267 research outputs found
Search for Drell Yan in squareroot s = 41.6 GeV p-N Collisions at HERA-b
In this thesis, the data taken with the HERA-b detector in the running period 2002/2003 is used to measure the cross section of the Drell Yan process, where quark and antiquark annihilate and produce a lepton pair. HERA-b, a fixed target spectrometer, is one of the four experiments at the storage ring HERA at DESY. It uses the proton beam to produce collisions with wire targets of different materials. The main challenge of the thesis is to extract a Drell Yan signal from the dataset without loosing too many events and to find a suitable background simulation which can be subtracted from the kinematical distributions. For this purpose, a Single Track Monte Carlo is generated to calculate event weights, which are applied to the likesign dataset. This procedure is necessary since the detector acceptance of HERA-b is dependant on the charges of the leptons. After background subtraction and acceptance and luminosity corrections, differential cross sections of the Drell Yan process are plotted, for the first time in the negative xf regime. These are compared to results from E772 and NA50. Also, the dependance of the Drell Yan cross section on the mass number of the target material is calculated
05101 Abstracts Collection -- Scheduling for Parallel Architectures: Theory, Applications, Challenges
From 06.03.05 to 11.03.05, the Dagstuhl Seminar 05101 ``Scheduling for Parallel Architectures: Theory, Applications, Challenges\u27\u27 was held
in the International Conference and Research Center (IBFI), Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general
Effects of vibroacoustic stimulation in music therapy for palliative care patients: a feasibility study
Background: The present study aimed at examining whether methodological strategies from a previously implemented study design could be transferred to the evaluation of the psychological and physiological effects of a music therapy intervention working with vibroacoustic stimulation in palliative care. Method: Nine participants suffering from advanced cancer took part in single-sessions of music therapy, lasting for 30Â min. The live music therapy intervention utilized singing chair sounds and vocal improvisation. Visual analogue scales (VAS) were used to assess self-ratings of pain, relaxation, and well-being before and after each session. During the intervention, we continuously recorded heart rate variability (HRV) as a measure of autonomic functioning. Data collection was complemented by a semi-structured interview to explore subjective experiences in more detail. Feasibility was defined as the ability to complete 80Â % of the sessions in accordance with the study protocol. Results: In 5 out of 9 sessions (55Â %) it was possible to deliver the intervention and obtain all data as intended. VAS assessment was feasible, although graphical and statistical examination revealed only marginal mean changes between pre and post. HRV recordings were subject to artifacts. While HRV parameters differed between individuals, mean changes over time remained relatively constant. Interview data confirmed that the individual perception was very heterogeneous, ranging from âcalmingâ to âoverwhelmingâ. Conclusion: The criterion of feasibility was not met in this study. Physiological data showed high attrition rates, most likely due to movement artifacts and reduced peripheral blood flow in some participantsâ extremities. Examination of individual-level trajectories revealed that vibroacoustic stimulation may have an impact on the autonomic response. However, the direction and mechanisms of effects needs to be further explored in future studies. Trial registration: German Clinical Trials Register â DRKS00006137 (July 4th, 2014)
Approaching a person in a socially acceptable manner using expanding random trees
In real world scenarios for mobile robots, socially acceptable navigation is a key component to interact naturally with other persons. On the one hand this enables a robot to behave more human-like, and on the other hand it increases the acceptance of the user towards the robot as an interaction partner. As part of this research field, we present in this paper a strategy of approaching a person in a socially acceptable manner. Therefore, we use the theory of âpersonal spaceâ and present a method of modeling this space to enable a mobile robot to approach a person from the front. We use a standard Dynamic Window Approach to control the robot motion and, since the personal space model could not be used directly, a graph planner in configuration space, to plan an optimal path by expanding the graph with the use of the DWAâs update rule. Additionally, we give a proof of concept with first preliminary experiments
Music Therapy in the Psychosocial Treatment of Adult Cancer Patients:A Systematic Review and Meta-Analysis
What Can We Learn about Neighborhood Effects from the Moving to Opportunity Experiment?
Experimental estimates from Moving to Opportunity (MTO) show no significant impacts of moves to lowerâpoverty neighborhoods on adult economic selfâsufficiency four to seven years after random assignment. The authors disagree with ClampetâLundquist and Massey's claim that MTO was a weak intervention and therefore uninformative about neighborhood effects. MTO produced large changes in neighborhood environments that improved adult mental health and many outcomes for young females. ClampetâLundquist and Massey's claim that MTO experimental estimates are plagued by selection bias is erroneous. Their new nonexperimental estimates are uninformative because they add back the selection problems that MTO's experimental design was intended to overcome.Economic
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Long-Term Neighborhood Effects on Low-Income Families: Evidence from Moving to Opportunity
We examine long-term neighborhood effects on low-income families using data from the Moving to Opportunity (MTO) randomized housing-mobility experiment. This experiment offered to some public-housing families but not to others the chance to move to less-disadvantaged neighborhoods. We show that ten to 15 years after baseline, MTO: (i) improves adult physical and mental health; (ii) has no detectable effect on economic outcomes or youth schooling or physical health; and (iii) has mixed results by gender on other youth outcomes, with girls doing better on some measures and boys doing worse. Despite the somewhat mixed pattern of impacts on traditional behavioral outcomes, MTO moves substantially improve adult subjective well-being.Economic
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Neighborhood Effects on the Long-Term Well-Being of Low-Income Adults
Nearly 9 million Americans live in extreme-poverty neighborhoods, places that also tend to be racially segregated and dangerous. Yet, the effects on the well-being of residents of moving out of such communities into less distressed areas remain uncertain. Using data from Moving to Opportunity, a unique randomized housing mobility experiment, we found that moving from a high-poverty to lower-poverty neighborhood leads to long-term (10- to 15-year) improvements in adult physical and mental health and subjective well-being, despite not affecting economic self-sufficiency. A 1âstandard deviation decline in neighborhood poverty (13 percentage points) increases subjective well-being by an amount equal to the gap in subjective well-being between people whose annual incomes differ by 20,000. Subjective well-being is more strongly affected by changes in neighborhood economic disadvantage than racial segregation, which is important because racial segregation has been declining since 1970, but income segregation has been increasing.Economic
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