Deficits in visual recognition in low birth weight infant pigtailed monkeys (Macaca nemestrina)

15 low birth weight and 15 normal birth weight pigtailed monkey infants were administered an adaptation of a standardized test of visual recognition memory, originally developed for human infants. Animals were given a series of problems in which 2 identical black-and-white patterns were presented for a familiarization period. The previously exposed pattern was then paired with a novel one, and looking time to each pattern was recorded. The normal birth weight animals directed a significant amount of their visual attention to the novel stimuli, thus demonstrating recognition abilities. As a group, the performance of the low birth weight infants remained at chance. These findings have important implications for an animal model to examine factors contributing to poor cognitive outcome in low birth weight human infants.     

The evidence base for the cues program for mothers of very low birth weight infants: an innovative approach to reduce anxiety and support sensitive interaction

Very low birth weight (VLBW) infants, born weighing less than 1,500 g, are at risk for several developmental problems. Consequently, there has been interest in developing intervention programs to prevent such problems. This article describes the empirical evidence that guided the development of an innovative, multicomponent intervention program for mothers of VLBW infants, as well as the program content and features. Based on the evidence, the program was designed to include six sessions and commence shortly after birth to reduce maternal psychological distress during the infant's hospitalization in the neonatal intensive care unit and to promote sensitive mother-infant interaction. The program incorporates various learning activities, including written materials, observational exercises, discussion, and video feedback.     

The effects of experience of early intervention on low birth weight,premature children: The infant health and development program

This study explores individuals' experience of early intervention in two settings (the home and the child development center) and the effect of that experience on child and parental outcomes in the Infant Health and Development Program (IHDP). The IHDP was a randomized clinical trial designed to test the efficacy of educational and family support services on reducing developmental delays in low birth weight (LEW), premature infants (N = 985) during the first 3 years of life. This study focused on children in the intervention group who received at least one home visit and one day at the center each year (n = 296). Three approaches to measuring participants' experience of intervention were defined—number of contacts in the home and at the child care center (i.e., Exposure), number of activities presented per visit to the parent in the home or per day to the child at the center (i.e., Rate); and a combination of the parent's interest in the intervention activities in the home and the child's mastery of the intervention tasks taught at the center (i.e., Active Experience). More substantial contributions to both child IQ and the HOME scores at age 3 were found with the Active Experience approach than with the Exposure or the Rate approach, after controlling for initial background variables, family socioeconomic status, children's initial IQ, and parental cognitive ability. Further, a high level of Active Experience from both the parent and the child was associated with higher IQ scores at ages 1, 2, and 3 and higher HOME scores at age 3 than was found when only a high level of Active Experience from only the parent or the child, or neither, was involved. Implications for future intervention programs are discussed.     

The medium term schooling and health effects of low birth weight: Evidence from siblings

Research has shown that low birth weight is linked to infant mortality as well as longer term outcomes. This paper examines the medium term outcomes that may link low birth weight to adult disadvantage using a national longitudinal sample with a large sample of siblings (Add Health). Results show strong effects on several educational outcomes, including early grade repetition, receipt of special education services, and reports of a learning disability. Results for longer term outcomes are suggestive, though less robust and small in magnitude. Overall, the results suggest that medium term educational disadvantages associated with low birth weight are not driven by family level unobservables and do not accumulate into large long-term disadvantage.     

低分子质量聚醋酸乙烯酯的合成与亲二氧化碳性能研究

为了提高碳氢类聚合物在二氧化碳中的溶解性能,通过合成2-丙酸甲酯基乙基黄原酸酯作为链转移剂,采用可逆加成断裂链转移(RAFT)聚合制备了低分子质量(Mn<8 000g/mol)、窄分子质量分布(Mw/Mn<1.6)的聚醋酸乙烯酯(PVAc)。该聚合过程具有明显的可控/活性特征,并以异丙醇作为氢原子供体有效去除PVAc末端的双硫酯基团。采用核磁共振(1 HNMR)、凝胶渗透色谱(GPC)表征PVAc的结构与分子质量,得到的结果与理论计算的目标分子质量一致。浊点测试结果表明:PVAc在二氧化碳中的溶解度随着分子质量的增大和溶解温度的升高而降低;PVAc分子链末端的双硫酯基团不利于聚合物溶解在二氧化碳中,且分子质量越低,影响越显著。     

Adult mental health outcomes of child sexual abuse survivors born at extremely low birth weight

The high prevalence of child sexual abuse (CSA) is concerning, particularly as survivors are at increased risk for multiple adverse outcomes, including poor mental health across the lifespan. Children born at an extremely low birth weight (ELBW; <1000 g) and who experience CSA may be a group that is especially vulnerable to psychopathology later in life. However, no research has considered the mental health risks associated with being born at ELBW and experiencing CSA. In this study, we investigated the mental health of 179 ELBW survivors and 145 matched normal birth weight (NBW; >2500 g) participants at ages 22–26 and 29–36. At age 22–26, CSA was associated with increased odds of clinically significant internalizing (OR = 7.32, 95% CI: 2.31–23.23) and externalizing (OR = 4.65, 95% CI: 1.11–19.51) problems among ELBW participants exposed to CSA compared to those who did not, though confidence intervals were wide. At age 29–36, CSA was linked to increased odds of any current (OR = 3.43, 95% CI: 1.08–10.87) and lifetime (OR = 7.09, 95% CI: 2.00–25.03) non-substance use psychiatric disorders, however, this did not hold after adjustment for covariates. Statistically significant differences in mental health outcomes were not observed in NBW participants exposed to CSA compared to NBW participants who were not exposed. Survivors of significant perinatal adversity who are also exposed to CSA may be at higher risk for psychopathology through the fourth decade of life.     

Joint attention and infant toy exploration: effects of Down syndrome and prematurity

12-month-old infants with Down syndrome (n = 14) and mental and motor age-matched high-risk preterm infants (n = 14) were studied with respect to their ability to attend to and explore their environment in interactions with their mothers. The effectiveness of particular maternal attention-directing techniques in modifying infant responses to toys was expected to vary across the 2 infant groups. In general, higher-level responses to toys were expected to be associated with mother's attempts to maintain rather than redirect the child's attention and the mother's use of structured verbal and nonverbal attention-directing techniques. Results indicated that mothers of the 2 groups of infants used different attention-directing strategies, and their use of particular strategies was differentially related to the attentional capacity of the 2 groups. Differences in the infants' responses to particular maternal strategies were related to the amount of structure provided and to the demands placed on their capacity to shift attention between objects. Fewer specific maternal techniques for directing attention elicited higher-level play behavior from the Down syndrome infants, compared to the preterm group.     

Influences on, and the consequences of, low achievement

The paper examines the influences on, and consequences of, low achievement defined as scores within the lowest achievement quartile. Low achievement is moderately associated with socioeconomic background and Indigenous status and the relationships with gender, ethnicity, region, family type, state and region differ for reading and mathematics. Low achievement substantially reduces the chances of school completion and university entrance. It has much less impact on other forms of post-secondary education and training. There are stronger differences in labour market outcomes between low and higher achievers for young women than for young men. This study suggests the policies promoting the securing of full-time work soon after completing full-time education should reduce the detrimental effects of low achievement on labour market outcomes.     

Dynamic assessment and its potential for the assessment of reading competence

This article describes the approach of dynamic assessment, focusing on general approaches as well as specific constraints for the assessment of reading competence. Starting with an overview of the literature on dynamic assessments within educational research, the framework of dynamic assessment in which the current level of competence and (domain-specific) learning ability are assessed, is discussed with regards to its methodological and diagnostic implications.Reading competence is introduced as a domain in which interventions prove successful, and as a domain principally suitable for the assessment of learning ability. Furthermore, it is discussed whether elaborated feedback given within the procedure of reading competence assessment does uncover a learning ability which is specific to the domain of reading competence or not.     

纹影特性测速算法修正及权重系数取值研究

针对流场的纹影图像测速算法,提出数据守恒项的修正形式,讨论了由于权重系数取值不当产生的2种错误,并分析了其表现形式和产生的原因。对修正前后的算法进行了比较,计算结果表明修正后的算法局部残差减小、计算收敛性增强、更不容易发生过度平滑。基于修正的算法,统计了不同权重系数取值对应计算结果的分布区间。将修正的算法应用于不同强度纵向声波扰动下的预混火焰流场纹影图像的速度场计算,发现火焰流场速度周期性波动的幅值随着扰动强度的增加而增加。     

Effects of pre-pregnancy body mass index and gestational weight gain on neonatal birth weight

To evaluate the effects of maternal pre-pregnancy body mass index (pre-BMI) and gestational weight gain (GWG) on neonatal birth weight (NBW) in the population of Chinese healthy pregnant women, attempting to guide weight control in pregnancy. A retrospective cohort study of 3772 Chinese women was conducted. The population was stratified by maternal pre-BMI categories as underweight (<18.5 kg/m²), normal weight (18.5–23.9 kg/m²), overweight (24.0–27.9 kg/m²), and obesity (≥28.0 kg/m²). The NBW differences were tested among the four groups, and then deeper associations among maternal pre-BMI, GWG, and NBW were investigated by multivariate analysis. NBW increased significantly with the increase of maternal pre-BMI level (P<0.05), except overweight to obesity (P>0.05). The multivariate analysis showed that both pre-BMI and GWG were positively correlated with NBW (P<0.05). Compared with normal pre-BMI, underweight predicted an increased odds ratio of small-for-gestational-age (SGA) and decreased odds ratio for macrosomia and large-for-gestational-age (LGA), and the results were opposite for overweight. With the increase of GWG, the risk of SGA decreased and the risks of macrosomia and LGA increased. In addition, in different pre-BMI categories, the effects of weight gain in the first trimester on NBW were different (P<0.05). NBW is positively affected by both maternal pre-BMI and GWG, extreme pre-BMI and GWG are both associated with increased risks of abnormal birth weight, and maternal pre-BMI may modify the effect of weight gain in each trimester on NBW. A valid GWG guideline for Chinese women is an urgent requirement, whereas existing recommendations seem to be not very suitable for the Chinese.     

Extended households and the life course of young mothers: understanding the associations using a sample of mothers with premature, low birth weight babies

This paper examined whether the greater average schooling and employment, and lower parenting competence, of young mothers who reside with adult relatives reflect preexisting differences versus potential causal mechanisms. The sample included 554 young mothers (ages 13 to 25; nearly two thirds African American) from the Infant Health and Development Program (IHDP) a random-assignment intervention study of premature, low birth weight babies followed 8 times from birth to age 3. Ordinary least squares, fixed-effects, and random-effects models indicated that young mothers of low birth weight babies sorted into extended households based on preexisting characteristics that were correlated with their lower parenting skills and knowledge. In contrast, coresidence predicted greater schooling or employment across models, with some variations for different subgroups.     

Assessment of student learning: Evolution of objectives in engineering education and the consequences for assessment

The focus of objectives of engineering education has evolved from knowledge to skills. This is a logical consequence of the changing demands of employers of graduated engineers. This change is referred to as a paradigm shift in engineering education. It is therefore not surprising that the views on assessment of student learning are changing as well. In this paper the relation between the demands and the educational objectives are reviewed. Consequently, the implications for assessment are discussed. Assessment is introduced as a feedback procedure. It is discussed that in fact four different feedback pathways can be identified. Finally, the relation between educational methods and their relation to assessment is discussed in detail. As an example, the problems in assessment of group work are discussed.     

Fetal cardiac responding: a correlate of birth weight and neonatal behavior

Certain intrapartum fetal heart-rate (FHR) patterns are associated with low Apgar scores and other neonatal risks. Intrapartum FHR has been the subject of extensive clinical investigation, but only occasional reference is made to the possible behavioral correlates of this phenomenon. The current investigation found that neonates classified as FHR decelerators had lower birth weights and shorter gestational ages than FHR accelerators. Decelerators exhibited higher baseline heart rate and experienced more frequent uterine contractions than accelerators. Neurobehavioral assessment of these neonates indicated that decelerators had more abnormal reflex ratings and were less behaviorally organized than heart-rate accelerators. The results indicate that FHR responses are associated with prenatal growth, maturity, and possibly stress tolerance, and that intrapartum FHR responses be related to nonoptimal neonatal behavior.     

低分子质量淀粉的制备及其结构研究

采用盐酸酸解法制备低分子质量淀粉,通过控制淀粉水解反应时间制备不同分子质量的淀粉产物。淀粉分子质量(Mv)随酸水解时间的延长不断降低,且与水解反应时间(t)呈乘幂关系,即Mv=4.43×10~5×t~(-1.41)。傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)、热重分析(thermal gravity analysis,TGA)和X射线衍射(X-Ray Diffraction,XRD)的研究结果表明,随着淀粉分子质量的降低,淀粉特征基团的数目逐渐增加,热稳定性逐渐降低。淀粉酸解后,其结晶结构发生变化,结晶度下降,且随着淀粉分子质量的降低,其结晶度由原淀粉的38.5%逐渐下降,直至结晶结构消失,变为无定形结构。所得结果为低分子质量淀粉结构性质的研究提供了一定的参考。     

低分子质量淀粉的制备及其结构研究

采用盐酸酸解法制备低分子质量淀粉,通过控制淀粉水解反应时间制备不同分子质量的淀粉产物。淀粉分子质量(M_v)随酸水解时间的延长不断降低,且与水解反应时间(t)呈乘幂关系,即M_v=4.43×10~5×t~(-1.41)。傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)、热重分析(thermal gravity analysis,TGA)和X射线衍射(X-Ray Diffraction,XRD)的研究结果表明,随着淀粉分子质量的降低,淀粉特征基团的数目逐渐增加,热稳定性逐渐降低。淀粉酸解后,其结晶结构发生变化,结晶度下降,且随着淀粉分子质量的降低,其结晶度由原淀粉的38.5%逐渐下降直至结晶结构消失,变为无定形结构。所得结果为低分子质量淀粉结构性质的研究提供了一定的参考。