HortiBot: A System Design of a Robotic Tool Carrier for High-tech Plant Nursing

Danish organic outdoor gardeners today use 50-300 hours per hectare for manual weeding. Through automatic controlling of an existing commercial machine this often heavy and costconsuming weeding will be eliminated. At the same time, a fully-automatic registration of field activities will contribute to the efficient implementation of EU directive 178/2002 concerning traceability in the primary production and thereby enhance the food-safety in the production chain. A radio controlled slope mower is equipped with a new robotic accessory kit. This transforms it into a tool carrier (HortiBot) for high-tech plant nursing for e.g. organic grown vegetables. The HortiBot is capable of passing over several parcels with visible rows autonomously based on a new commercial row detection system from Eco-Dan a/s, Denmark. This paper presents the solutions chosen for the HortiBot with regard to hardware, mechanicalelectrical interfaces and software. Further, the principles from a Quality Function Deployment (QFD) analysis was used to carry out the solicitation, evaluation and selection of most qualified design parameters and specifications attained to a horticultural robotic tool carrier. The QFD analysis provided a specific measure to evaluate each selected parameter in terms of satisfying user requirements and operational performance aspects. Based on a combination of importance rating and competitive priority ratings important user requirements include easy adaptation to field conditions in terms of row distance and parcel size, profitability, minimum crop damage during operation, and reliability. Lesser importance was attributed to affection value, attractive look, the possibility of out of season usage, and the use of renewable energy

Childhood body mass index and height and risk of histologic subtypes of endometrial cancer

BACKGROUND: Endometrial cancer risk factors include adult obesity and taller stature, but the influence of size earlier in life is incompletely understood. We examined whether childhood body mass index (BMI; kg m(−2)) and height were associated with histologic subtypes of endometrial cancer. METHODS: From the Copenhagen School Health Records Register, 155 505 girls born 1930–1989 with measured weights and heights from 7 to 13 years were linked to health registers. BMI and height were transformed to age-specific z-scores. Hazard ratios (HRs) and 95% confidence intervals were estimated by Cox regressions. RESULTS: A total of 1020 endometrial cancers were recorded. BMI was non-linearly associated with all endometrial cancers, oestrogen-dependent cancers and the subtype of endometrioid adenocarcinomas; associations were statistically significant and positive above a z-score=0 and non-significant below zero. Compared with a 7-year-old girl with a BMI z-score=0, an equally tall girl who was 3.6 kg heavier (BMI z-score=1.5) had a hazard ratio=1.53 (95% confidence interval: 1.29–1.82) for endometrioid adenocarcinoma. BMI was not associated with non-oestrogen-dependent cancers, except at the oldest childhood ages. Height at all ages was statistically significant and positively associated with all endometrial cancers, except non-oestrogen-dependent cancers. At 7 years, per ~5.2 cm (1 z-score), the risk of endometrioid adenocarcinoma was 1.18 (95% confidence interval: 1.09–1.28). Among non-users of unopposed oestrogens, associations between BMI and endometrioid adenocarcinoma strengthened, but no effects on height associations were observed. CONCLUSIONS: Endometrial carcinogenesis is linked to early-life body size, suggesting that childhood BMI and height may be useful indicators for the risk of later development of endometrial cancer and might aid in the early prevention of obesity-related endometrial cancers

Neonatal Vitamin D Levels in Relation to Risk of Overweight at 7 Years in the Danish D-Tect Case-Cohort Study

Background: Vitamin D level in pregnancy may be associated with risk of overweight in the offspring later in life. Methods: In a case-cohort study based on Danish biobanks and registers we examined the association between 25-hydroxy-vitamin D (25(OH)D) level at birth and overweight at 7 years. Cases of overweight (n = 871) were randomly selected among 7-year-old children from the Copenhagen School Health Records Register (CSHRR) with a BMI above the 90th percentile. The cohort (n = 1,311) was a random sample selected among all Danish children born during the same period. Neonatal 25(OH)D was measured in dried blood spots. Results: 25(OH)D3 exhibited the expected seasonal variation. Median level of 25(OH)D3 was 20.6 (11.9-33.3) nmol/l in the overweight group and 23.4 (13.5-34.3) nmol/l in the cohort. We found no association between neonatal 25(OH)D3 level and risk of overweight at age 7 years, neither in the crude model (OR (CI) 1.00 (0.99; 1.00)) nor in a model adjusted for maternal ethnicity, educational level, civil status, parity, season and year of birth, and offspring ponderal index (OR (CI) 1.00 (0.99; 1.01)). Conclusion: Risk of overweight at 7 years of age was not associated with vitamin D level at birth

S=1/2S=1/2 Chain-Boundary Excitations in the Haldane Phase of 1D S=1S=1 Systems

The $s=1/2$ chain-boundary excitations occurring in the Haldane phaseof $s=1$ antiferromagnetic spin chains are investigated. The bilinear-biquadratic hamiltonian is used to study these excitations as a function of the strength of the biquadratic term, $\beta$, between $-1\le\beta\le1$. At the AKLT point, $\beta=-1/3$, we show explicitly that these excitations are localized at the boundaries of the chain on a length scale equal to the correlation length $\xi=1/\ln 3$, and that the on-site magnetization for the first site is $=2/3$. Applying the density matrixrenormalization group we show that the chain-boundaryexcitations remain localized at the boundaries for $-1\le\beta\le1$. As the two critical points $\beta=\pm1$ are approached the size of the $s=1/2$ objects diverges and their amplitude vanishes.Comment: 4 Pages, 4 eps figures. Uses RevTeX 3.0. Submitted to PR

The Ground State Energy of Heavy Atoms According to Brown and Ravenhall: Absence of Relativistic Effects in Leading Order

It is shown that the ground state energy of heavy atoms is, to leading order, given by the non-relativistic Thomas-Fermi energy. The proof is based on the relativistic Hamiltonian of Brown and Ravenhall which is derived from quantum electrodynamics yielding energy levels correctly up to order $\alpha^2$Ry

Prevalence of lifestyle characteristics in glucocorticoid users and non-users: a Danish population-based cross-sectional study

OBJECTIVES Lifestyle may affect observed associations between glucocorticoid use and adverse events. This study aimed to investigate whether lifestyle differ according to use of systemic glucocorticoids. DESIGN Population-based cross-sectional study. SETTING The Central Denmark Region. PARTICIPANTS 30 245 adults (≥25 years of age) who participated in a questionnaire-based public health survey in 2010. OUTCOME MEASURES Systemic glucocorticoid use was categorised as never use, current use (prescription redemption ≤90 days before completing the questionnaire), recent use (prescription redemption 91–365 days before completing the questionnaire), former use (prescription redemption >365 days before completing the questionnaire) and according to cumulative dose expressed in prednisolone equivalents (<100, 100–499, 500–999, 1000–1999, 2000–4999, ≥5000 mg). We computed the prevalence of lifestyle factors (body mass index, smoking, alcohol intake, physical activity and dietary habits) according to glucocorticoid use. We then estimated age-adjusted prevalence ratios (aPRs) and 95% CIs, comparing the categories of glucocorticoid users versus never users. All analyses were stratified by sex. RESULTS Of the 30 245 participants (53% women, median age 53 years), 563 (1.9%) were current users, 885 (2.9%) were recent users, 3054 (10%) were former users and 25 743 (85%) were never users. Ever users of glucocorticoids had a slightly higher prevalence of obesity than never users (18% vs 14%, aPR=1.4, 95% CI 1.2 to 1.5 in women and 17% vs 15%, aPR=1.2, 95% CI 1.1 to 1.4 in men). In women, ever users of glucocorticoids had a slightly lower prevalence of high-risk alcohol consumption compared with never users (17% vs 20%, aPR=0.8, 95% CI 0.7 to 1.0). Smoking, diet and physical activity did not differ substantially according to use of glucocorticoids. CONCLUSION Our study provides a framework for quantifying potential uncontrolled confounding by lifestyle factors in studies of systemic glucocorticoids

Comparison of birth weight between school health records and medical birth records in Denmark:determinants of discrepancies

OBJECTIVE: To compare reported birth weight (BW) information in school health records with BW from medical birth records, and to investigate if maternal and offspring characteristics were associated with any discrepancies. DESIGN: Register-based cohort study. SETTING: Denmark, 1973–1991. PARTICIPANTS: The study was based on BW recorded in the Copenhagen School Health Records Register (CSHRR) and in The Medical Birth Register (MBR). The registers were linked via the Danish personal identification number. PRIMARY AND SECONDARY OUTCOME MEASURES: Statistical comparisons of BW in the registers were performed using t tests, Pearson's correlation coefficients, Bland-Altman plots and κ coefficients. Odds of BW discrepancies >100 g were examined by logistic regressions. RESULTS: The study population included 47 534 children. From 1973 to 1979 when BW was grouped in 500 g intervals in the MBR, mean BW differed significantly between the registers. During 1979–1991 when BW was recorded in 10 and 1 g intervals, mean BW did not significantly differ between the two registers. BW from both registers was highly correlated (0.93–0.97). Odds of a BW discrepancy significantly increased with parity, the child's age at recall and by marital status (children of married women had the highest odds). CONCLUSIONS: Overall, BW information in school health records agreed very well with BW from medical birth records, suggesting that reports of BWs in school health records in Copenhagen, Denmark generally are valid