A Subpath-based Logit Model to Capture the Correlation of Routes

A subpath-based methodology is proposed to capture the travellers’ route choice behaviours and their perceptual correlation of routes, because the original link-based style may not be suitable in application: (1) travellers do not process road network information and construct the chosen route by a link-by-link style; (2) observations from questionnaires and GPS data, however, are not always link-specific. Subpaths are defined as important portions of the route, such as major roads and landmarks. The cross-nested Logit (CNL) structure is used for its tractable closed-form and its capability to explicitly capture the routes correlation. Nests represent subpaths other than links so that the number of nests is significantly reduced. Moreover, the proposed method simplifies the original link-based CNL model; therefore, it alleviates the estimation and computation difficulties. The estimation and forecast validation with real data are presented, and the results suggest that the new method is practical

A Subpath-based Logit Model to Capture the Correlation of Routes

A subpath-based methodology is proposed to capture the travellers’ route choice behaviours and their perceptual correlation of routes, because the original link-based style may not be suitable in application: (1) travellers do not process road network information and construct the chosen route by a link-by-link style; (2) observations from questionnaires and GPS data, however, are not always link-specific. Subpaths are defined as important portions of the route, such as major roads and landmarks. The cross-nested Logit (CNL) structure is used for its tractable closed-form and its capability to explicitly capture the routes correlation. Nests represent subpaths other than links so that the number of nests is significantly reduced. Moreover, the proposed method simplifies the original link-based CNL model; therefore, it alleviates the estimation and computation difficulties. The estimation and forecast validation with real data are presented, and the results suggest that the new method is practical

Risks of small-for-gestational-age births in immigrants: A nationwide epidemiological study in Sweden.

Aim: To examine if there is an association between country of birth in parents and small-for-gestational-age (defined as a birthweight of more than two standard deviations (SDs) below the mean) in first singletons births. Methods: In this follow-up study, national population and healthcare registers were used to identify small-for-gestational-age births in all first singleton births in Sweden between 1 January 1982 and 31 December 2006. Odds ratios, standardised with regard to maternal age at birth, period of birth, marital status, family income, geographical region, employment, maternal height, and smoking history, were estimated by maternal and paternal country of birth. Singletons with both parents born in Sweden were used as reference group. Results: There were 1,060,467 records for first singletons births over the study period, of whom 3.5% were small-for-gestational-age. The rate was higher in newborns with non-Swedish born than in those with Swedish born mothers (4.1 and 3.3%, respectively). Immigrants from Southern European countries, Africa, and Asia had higher risks of small-for-gestational-age in than those in the reference group, and the risks were even higher in compatriot parents. CONCLUSIONS: Country of birth affected the risk of small-for-gestational-age. Maternity care should pay a special attention to pregnancies in certain population groups

Immigrants and Preterm Births: A Nationwide Epidemiological Study in Sweden.

To examine, nationwide, if there is an association between country of birth in mothers and preterm birth and to study whether any such association remains in second-generation immigrant women. In this follow-up study, a nationwide research database located at Lund University, Sweden, was used to identify all preterm born singletons in Sweden between January 1, 1982, and December 31, 2006. Incidence ratios were standardized with regard to maternal age at birth, marital status, geographical region, body height, and smoking history as well as period of birth, family income, and gender of the infant. Singletons of mothers born in Sweden were used as the reference group. There were 2,192,843 records for singletons over the study period, of whom 4.9 % were preterm births and 0.8 % were very preterm births. Increased risk of preterm birth was observed for mothers from Austria, Yugoslavia, Romania, Central Europe, and Asia. Increased risk of very preterm birth was observed for mothers from Eastern Europe, Central Europe, Africa, and Asia; these increased risk disappeared, however, in the second-generation female immigrants. Country of birth in mothers affected the risk of preterm birth; maternity care should pay special attention to women from certain population groups

Research on the Application of Computational Materials Science in Undergraduate Teaching

In this paper, by taking first-principles software as examples, we apply computational materials science to the teaching process of undergraduates majoring in physics, chemistry and materials. We pay attention to the connection between theoretical research and experimental models, makes the abstract principle intuitive and dynamic, and facilitates students’ understanding of knowledge, a deep understanding of the structure of materials and the relationship between theoretical properties and macro properties, which can greatly enhance students’ initiative and creativity in participating in teaching activities. To a great extent, this has played a role of computational simulation as a bridge between theoretical teaching and experimental teaching to continue to explore the complementary relationship between computational simulation, theoretical teaching and experimental teaching, build a teaching model for the application and design ability training of materials and chemistry talents

Subsequent Risks of Parkinson Disease in Patients with Autoimmune and Related Disorders: A Nationwide Epidemiological Study from Sweden.

Objectives: To investigate associations between autoimmune disorders and Parkinson disease (PD), and to study whether the risk is associated with follow-up time and age. Methods: Standardized incidence ratios (SIRs) were calculated for PD in patients with autoimmune disorders by comparing them to subjects without autoimmune disorders. Results: Among 310,522 patients with a total of 33 conditions of autoimmune disorders, 932 patients developed subsequent PD, giving an overall SIR of 1.33 and 1.19 for PD diagnosed later than 1 year after follow-up. Six types of autoimmune disorders showed an increased risk. These conditions included: amyotrophic lateral sclerosis, Graves's disease/hyperthyroidism, Hashimoto's disease/hypothyroidism, multiple sclerosis, pernicious anemia, and polymyalgia rheumatica. The risks depended on the age at hospitalization for PD. Conclusions: A 33% overall excess risk of PD was noted among patients with an autoimmune disorder; the risk was increased during the first 10 years of follow-up after hospitalization of autoimmune disorders

Parental poverty and occupation as risk factors for pediatric sleep-disordered breathing.

Previous studies have found associations between pediatric sleep-disordered breathing (SDB) and socioeconomic status (SES), as well as a neighborhood-related disadvantage. This study analyzes the association among familial SES, parental occupation, and SDB in Swedish offspring