Overestimation of self-reported driving exposure: Results from the SHRP2 Naturalistic Driving Study

Objectives: The accuracy of self-reported driving exposure has questioned the validity of using self-reported mileage to inform research questions. Studies examining the accuracy of self-reported driving exposure compared to objective measures find low validity, with drivers overestimating and underestimating driving distance. The aims of the current study were to (1) examine the discrepancy between self-reported annual mileage and driving exposure the following year and (2) investigate whether these differences depended on age and annual mileage.

Methods: Two estimates of drivers’ self-reported annual mileage collected during vehicle installation (obtained via prestudy questionnaires) and approximated annual mileage driven (based upon Global Positioning System data) were acquired from 3,323 participants who participated in the Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study.

Results: A Wilcoxon signed rank test showed that there was a significant difference between self-reported and annual driving exposure during participation in SHRP 2, with the majority of self-reported responses overestimating annual mileage the following year, irrespective of whether an ordinal or ratio variable was examined. Over 15% of participants provided self-reported responses with over 100% deviation, which were exclusive to participants underestimating annual mileage. Further, deviations in reporting differed between participants who had low, medium, and high exposure, as well as between participants in different age groups.

Conclusions: These findings indicate that although self-reported annual mileage is heavily relied on for research, such estimates of driving distance may be an overestimate of current or future mileage and can influence the validity of prior research that has utilized estimates of driving exposure.     

Coat color polymorphism in populations of the northern mole vole in the Ural Region

Collections made in the course of long-term field studies on ecology of the northern mole vole Ellobius talpinus Pall. in the Ural Region and neighboring areas (more than 2000 individuals from 24 points of the species range) were used to analyze geographic variation in its coat color (color morphs). On the basis of long-term observations (1985–1999) on marked animals from a polymorphic population (Kurtamyshskii raion, Kurgan oblast), the life spans of males and females and the dependence of life span on population density and structure were estimated in animals of different color morphs. Each color morph of E. talpinus was shown to have specific features of the seasonal dynamics of age structure and migrations.     

Fluctuations of Population Size and Structure in the Northern Mole Vole: Preliminary Analysis

Long-term stationary studies on the ecology of the northern mole vole (Ellobius talpinus Pall.), performed by the mark–recapture method from 1985 to 1997, have provided original data on population dynamics and structure. The analysis shows that, to reveal cyclic fluctuations of population size in this species, the period of three years should be taken as a unit of time for estimating the duration of one phase. The 12-year population cycle in E. talpinus has four distinct phases: an increase, a peak, a decline, and a minimum. At each phase, the population is characterized by certain features of family structure, age composition, birth and death rates, and the composition of migrants.     

铜陵石炭纪威宁期沉积相及与黄铁矿矿床的关系

铜陵地区石炭纪威宁期存在潮坪相,泻湖相和浅海陆棚相。白云岩有两种,准同生白云岩分布于潮坪,成岩白云岩分布于泻湖内,本区以成岩白云岩为主。白云岩中赋存了层位稳定的黄铁矿矿床,黄铁矿在泻湖相最易富集,成岩作用是黄铁矿矿床形成的一个重要因素。     

湖北黄梅乱泥滩花岗岩体的同位素年龄及成因初析

黄梅乱泥滩花岗岩侵入年龄为124.1Ma,完全冷却暴露地表年龄为80Ma,据岩石化学、稀土元素地球化学、~(87)Sr/~(86)Sr初始比值、∈Nd值、δ~(18)0值等综合分析,均显示该岩体具有“S”型花岗岩类的特征,其原始物质来自地壳。岩浆侵位深度为4.8km,结晶温度为798℃,氧逸度fO_2=1×10~(-11)a,压力P=6.57×10~8Pa岩体侵位时处于张性构造环境的陆内碰撞带。     

Maternal age specific rates for chromosome aberrations and factors influencing them: Report of a collaborative european study on 52 965 amniocenteses

Maternal age specific rates for all major chromosome aberrations have been determined in 52 965 pregnancies in mothers 35 years of age and over at the time of amniocentesis. Rates increase exponentially with advancing maternal age for trisomies 21, 18 and 13, and for the XXX and XXY syndromes, but in the autosomal trisomies this rise appears to be followed by a levelling off at the upper end of the age range. A significant inverse relationship with maternal age is found for 45,X cases. It is postulated that these various patterns are the result of the interaction of three principal factors: a maternal age effect acting particularly on first meiotic nondisjunction: a higher spontaneous abortion rate with advancing maternal age for aneuploid as compared to euploid conceptions; and an increased probability of spontaneous abortion before the time of amniocentesis for conceptions with more extensive chromosome imbalance. A stepwise logistic regression analysis of 13 299 pregnancies in which both parental ages are known shows that the father's age does not influence these maternal age specific rates, with the possible exception of the 47,XXY syndrome.     

Reproductive behaviour and prenatal diagnosis following genetic termination of pregnancy in women of advanced maternal age

One hundred and fifty-one women of advanced maternal age who underwent genetic termination of pregnancy (TOP) were studied for their reproductive behaviour and the type of procedure for prenatal diagnosis in a subsequent pregnancy. A total of 59 women (39 per cent) had a further pregnancy. In all continuing pregnancies prenatal diagnosis was performed, of which 75 per cent consisted of chorionic villus sampling (CVS). Reproductive behaviour following a genetic termination was negatively correlated with maternal age and parity. Both reproductive behaviour and the choice to undergo a diagnostic procedure in the next pregnancy were independent of the type of diagnostic procedure in the previous affected pregnancy.     

序批式反应器的水力停留时间的理论探讨

根据液龄分布函数是二元函数的观点．推导出了当进、出水流量是时间的函数时，反应器的水力停留时间的通用积分式和离散式；然后得出了序批式反应器(SBR）的水力停留时间(HRT)具体表达式，并分析了用现有方法计算其水力停留时间所产生的误差．结果表明，最大相对误差rmax仅与充水比λ有关．且呈正相关关系．取典型值λ=0．4时，rmax高达25％。     

Estimating the risk of a fetal autosomal trisomy at mid-trimester using maternal serum alpha fetoprotein and age: A retrospective study of 142 pregnancies

Risks appropriate for mid-trimester prenatal screening for autosomal trisomies have been estimated from a combination of maternal age and maternal serum (MS) alpha-fetoprotein (AFP) levels at 16–20 weeks gestation. Published data on the frequency of Down's syndrome births relative to maternal age were modified to include the additional age-related frequency of trisomy 18 and trisomy 13 cases to provide an overall risk for an autosomal trisomy at midtrimester. MSAFP results from a retrospective study of 142 affected (114 trisomy 21, 19 trisomy 18, and 9 trisomy 13)and 113 000 unaffected pregnancies were converted to multiples of the appropriate gestational median (MOM). The AFP levels in the autosomal trisomy pregnancies were found to be significantly reduced at 0.72 MOM of the unaffected pregnancies. Risks (likelihood ratios) were derived from the overlapping log Gaussian distributions for affected and unaffected pregnancies and combined with maternal age risks to give the overall odds of an affected pregnancy. A mid-trimester cut-off risk of 1:280 gave an estimated 37 per cent detection rate for autosomal trisomies in the west of Scotland population for a follow-up (false-positive) rate of 6.6 per cent. These figures compare with a 30 per cent detection and 6.7 per cent false-positive rate if age 35 years and over is used as the sole criterion for selection of at-risk pregnancies.