309 research outputs found
Censored Quantile Regressions and the Length of Unemployment Periods in West Germany
In this paper, we estimate the effect of different macro and micro variables on thedistribution of unemployment duration in West Germany using censored quantile regressions. We analyze unemployment periods of more than 91,000 observations from the years 1981 to 1997 drawn from the IAB employment subsample. The latter is an administrative data set that is representative with respect to the socially insured workforce. Surprisingly, we find that the educational degree and variables indicating the macroeconomic environment such as the unemployment rate have a weak effect only. On the other hand, variables reflecting the (un-)employment history of an individual such as the length of tenure, recall to the same employer in the past, recent unemployment and the position in the population income distribution before unemployment have the strongest effects on unemployment duration. We conclude that work history variables are the ones most suitable in characterizing the unemployment duration of an individual. From a methodological point of view, it is interesting that some regression coefficients have a different sign depending on the quantiles of the unemployment duration distribution. This clearly is a violation of the classical proportional hazard assumption which is very common in unemployment duration analysis. --censored quantile regression,unemployment duration,administrative data
Censored Quantile Regressions and the Length of Unemployment Periods in West Germany
We apply censored quantile regressions to representative German register data with more than 91,000 observations in order to determine crucial factors that influence the distribution of unemployment duration in West Germany during the 1980s and 1990s. We find that the effect of some regressors varies and has different sign depending on the quantiles of the unemployment duration distribution â a violation of the classical proportional hazard assumption which is very popular in unemployment duration analysis. We also find that variables reflecting the (un-)employment history of an individual such as the length of tenure, recall to the same employer in the past, recent unemployment and the position in the population income distribution before unemployment have the strongest effects on unemployment duration. We conclude that work history variables are most suitable in characterizing the job search behavior of an individual. The macroeconomic environment and the educational degree seem to have a limited effect only. --censored quantile regression,unemployment duration,register data
Censored Quantile Regressions and the Length of Unemployment Periods in West Germany
We apply censored quantile regressions to representative German register data with more than 91,000 observations in order to determine crucial factors that influence the distribution of unemployment duration in West Germany during the 1980s and 1990s. We find that the effect of some regressors varies and has different sign depending on the quantiles of the unemployment duration distribution â a violation of the classical proportional hazard assumption which is very popular in unemployment duration analysis. We also find that variables reflecting the (un-)employment history of an individual such as the length of tenure, recall to the same employer in the past, recent unemployment and the position in the population income distribution before unemployment have the strongest effects on unemployment duration. We conclude that work history variables are most suitable in characterizing the job search behavior of an individual. The macroeconomic environment and the educational degree seem to have a limited effect only
EP-1362: Influence of the phantom material on the absorbed-dose energy dependence of the EBT3 radiochromic film
Sequential and direct two-photon double ionization of D2 at FLASH
ABSTRACT: Sequential and direct two-photon double ionization (DI) of D2 molecule is studied experimentally and theoretically at a photon energy of 38.8 eV. Experimental and theoretical kinetic energy releases of D++D+ fragments, consisting of the contributions of sequential DI via the D2+(1ssg) state and direct DI via a virtual state, agree well with each other
Bacterial activity in cystic fibrosis lung infections
BACKGROUND: Chronic lung infections are the primary cause of morbidity and mortality in Cystic Fibrosis (CF) patients. Recent molecular biological based studies have identified a surprisingly wide range of hitherto unreported bacterial species in the lungs of CF patients. The aim of this study was to determine whether the species present were active and, as such, worthy of further investigation as potential pathogens. METHODS: Terminal Restriction Fragment Length Polymorphism (T-RFLP) profiles were generated from PCR products amplified from 16S rDNA and Reverse Transcription Terminal Restriction Fragment Length Polymorphism (RT-T-RFLP) profiles, a marker of metabolic activity, were generated from PCR products amplified from 16S rRNA, both extracted from the same CF sputum sample. To test the level of activity of these bacteria, T-RFLP profiles were compared to RT-T-RFLP profiles. RESULTS: Samples from 17 individuals were studied. Parallel analyses identified a total of 706 individual T-RF and RT-T-RF bands in this sample set. 323 bands were detected by T-RFLP and 383 bands were detected by RT-T-RFLP (statistically significant; P †0.001). For the group as a whole, 145 bands were detected in a T-RFLP profile alone, suggesting metabolically inactive bacteria. 205 bands were detected in an RT-T-RFLP profile alone and 178 bands were detected in both, suggesting a significant degree of metabolic activity. Although Pseudomonas aeruginosa was present and active in many patients, a low occurrence of other species traditionally considered to be key CF pathogens was detected. T-RFLP profiles obtained for induced sputum samples provided by healthy individuals without CF formed a separate cluster indicating a low level of similarity to those from CF patients. CONCLUSION: These results indicate that a high proportion of the bacterial species detected in the sputum from all of the CF patients in the study are active. The widespread activity of bacterial species in these samples emphasizes the potential importance of these previously unrecognized species within the CF lung
Meta-analysis of genome-wide association studies from the CHARGE consortium identifies common variants associated with carotid intima media thickness and plaque
Carotid intima media thickness (cIMT) and plaque determined by ultrasonography are established measures of subclinical atherosclerosis that each predicts future cardiovascular disease events. We conducted a meta-analysis of genome-wide association data in 31,211 participants of European ancestry from nine large studies in the setting of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. We then sought additional evidence to support our findings among 11,273 individuals using data from seven additional studies. In the combined meta-analysis, we identified three genomic regions associated with common carotid intima media thickness and two different regions associated with the presence of carotid plaque (P < 5 Ă 10 -8). The associated SNPs mapped in or near genes related to cellular signaling, lipid metabolism and blood pressure homeostasis, and two of the regions were associated with coronary artery disease (P < 0.006) in the Coronary Artery Disease Genome-Wide Replication and Meta-Analysis (CARDIoGRAM) consortium. Our findings may provide new insight into pathways leading to subclinical atherosclerosis and subsequent cardiovascular events
A descriptive analysis of relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke
<p>Abstract</p> <p>Background</p> <p>The aims of the present study were to examine relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke, as assessed by urinary cotinine-to-creatinine ratio (CCR), and to describe the CCR over seven days among infants at home.</p> <p>Methods</p> <p>A convenience sample of 27 households was drawn. Each household had to have at least one daily tobacco smoker and one child up to three years of age. Over a seven-day period, urine samples were obtained from the child daily. To examine relations between parents' self-reported smoking and infants' daily CCR, generalized estimating equation (GEE) analysis was used.</p> <p>Results</p> <p>The data revealed that infants from households with indoor smoking had higher CCRs than infants in households with outdoor smoking. CCRs were higher in girls than in boys. Older infants had lower CCRs than younger infants. Smoking outside the home versus inside the home, infant's gender, and infants' age accounted for 68% of the variance in CCR in a GEE data analysis model. No increase or decrease of CCR over time was found.</p> <p>Conclusion</p> <p>The findings suggest that parents' self-reported smoking indoors at home versus outdoors is predictive of CCR among infants three and younger. Higher CCR concentrations in girls' urine need further examination. Furthermore, significant fluctuations in daily CCR were not apparent in infants over a seven-day time period.</p
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