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1.
In order to investigate possible contamination of saliva samples with formula or breast milk obtained from young infants for cortisol assays, we measured cortisol concentrations in 3 common infant milk formulas and in breast milk before and after defatting and extraction using a commercial radioimmunoassay kit. Cortisol concentrations obtained prior to defatting and extraction were equal to or higher than (1.64-82.80 micrograms/dL) levels reported for salivary cortisol levels reported in newborn infants (0.09-2.08 micrograms/dL). Cortisol concentrations obtained after the defatting and extraction were lower (0.02-0.15 micrograms/dL), indicating that values obtained prior to defatting and extraction were due to cross-reacting substances as well as cortisol. As saliva samples are not routinely defatted or extracted prior to being assayed, high cortisol levels and interfering substances in formula and breast milk could contaminate salivary cortisol measurements in young infants. The present study suggests that appropriate controls should be taken when making salivary cortisol measurements in young infants to help ensure accurate results.  相似文献   

2.
3 studies of adrenocortical activity in healthy 9-month-old infants were conducted to examine unanticipated results obtained in previous research. In the first study, morning naps were examined and found to be associated with significant decreases in salivary cortisol. These decreases were followed by a significant return to prenap cortisol concentrations. In the second study, riding for 40 min in the car was also shown to significantly lower salivary cortisol concentrations. This effect was obtained both for infants who did and who did not sleep during the car trip. In the third study, the effect of 30 min of maternal separation in the laboratory on salivary cortisol was compared to the effect of 30 min of play with mother present. Separation resulted in significantly higher salivary cortisol concentrations as compared to play with mother present. In general, correlations between cortisol and behavior were found to be nonsignificant under conditions that did not produce stress elevations in cortisol, while less positive, more distressed behaviour was significantly correlated with cortisol under separation or stress conditions.  相似文献   

3.
The following project aimed at promoting integrated and long-lasting learning is described for an Immunology course, but it may be adapted to other disciplines. Students were asked to develop and carry out a research project to examine the relationship between immune function and stress. The experiments were required to include the assessment of salivary cortisol and salivary IgA (sIgA) with enzyme immunoassays. All other aspects of the experiments were developed by student groups with appropriate guidance from the instructor. Data are presented for one group project that assessed the effect of music on cortisol and sIgA. Overall levels of sIgA and cortisol were consistent with reported values. Students found a significant decrease in cortisol over time. Additionally, there was a trend that supported the overall student hypothesis regarding the effect of stress and immune function. Compared with the same Immunology course that included an instructor-designed experiment using enzyme immunoassays for cortisol and sIgA, several assessments (e.g., final grades and comments on student evaluations) show that overall learning seemed to be much better in the course with the student-directed research project.  相似文献   

4.
Salivary cortisol levels were assessed in 19-month-old infants following the Ainsworth Strange Situation procedure. 38 infants participating in Project Steep at the University of Minnesota served as subjects. Project Steep is a longitudinal intervention program designed to promote healthy parent-child relationships and to prevent emotional problems among children born to mothers who are at high risk for parenting problems. Following the Strange Situation, saliva samples were collected and assayed for cortisol, a steroid hormone frequently examined in studies of stress. Behavior during the Strange Situation was coded by trained coders, and attachment classifications were determined for each infant. Cortisol concentrations did not differ between the 6 Avoidant/Resistant (A/C) and 17 Securely Attached (B) toddlers. Toddlers ( n = 11) who were classified as having Disorganized/Disoriented (Type D) attachments exhibited higher cortisol concentrations than toddlers in the traditional (ABC) classifications. Results of this study were consistent with a model of stress reactivity that conceptualizes the organization of coping behaviors as a factor that mediates physiological stress responses.  相似文献   

5.
Cortisol Release in Infants in Response to Inoculation   总被引：1，自引：0，他引：1  
Using a cross-sectional design, salivary cortisol was obtained from infants aged 2, 4, and 6 months, prior to and 15 min following an inoculation. Cortisol rose significantly following inoculation. Behavioral responses to inoculation were consistent with the observed patterns of cortisol release. Cortisol base level was significantly and negatively related to the cortisol change score. At 6 months the basal levels also were influenced by an adult-like circadian rhythm; infants tested shortly after awakening had higher basal levels than those tested later in the day. These data provide strong evidence that studies of stress and cortisol release in infants must be sensitive to basal level, circadian rhythm, and behavioral effects, and that appropriate statistical procedures should be employed.  相似文献   

6.
The data combine objectively measured sleep and thrice‐daily salivary cortisol collected from a 4‐day diary study in a large Midwestern city with location data on all violent crimes recorded during the same time period for N = 82 children (Mage = 14.90, range = 11.27–18.11). The primary empirical strategy uses a within‐person design to measure the change in sleep and cortisol from the person's typical pattern on the night/day immediately following a local violent crime. On the night following a violent crime, children have later bedtimes. Children also have disrupted cortisol patterns the following morning. Supplementary analyses using varying distances of the crime to the child's home address confirm more proximate crimes correspond to later bedtimes.  相似文献   

7.
Self-regulation ability is an important component of children's academic success. Physiological reactivity may relate to brain activity governing attention and behavioral regulation. Saliva samples collected from 186 preschool children (101 boys, mean age = 53 months, 34% minority) before and after a series of mildly challenging games and again 30 min following the challenges were used to assess hypothalamic–pituitary–adrenal (HPA) (cortisol) and sympathetic nervous system (SNS; alpha-amylase) activity. Behavioral regulation was measured in delay of gratification and slow-down motor activities included in the challenge task. Cortisol and alpha-amylase were related differentially to aspects of behavioral regulation. Low cortisol was related to classroom regulation difficulties. Children with greater cortisol elevations following the challenge task had poorer performance on the slow-down motor task. Children with greater increases in salivary alpha-amylase following challenge were less able to delay gratification. Results suggest that HPA axis and SNS arousal may contribute differentially to behavioral regulation ability.  相似文献   

8.
Previous research has demonstrated that the development and communication of explicit marking criteria have resulted in improved grades for students. This improvement in performance has only been reported for coursework assignments. Therefore, it was the purpose of this study to investigate the impact of providing explicit marking criteria, alongside practice with the criteria, on student examination grades. Two cohorts attending their second year on a sport science degree were used. The first cohort served as a control group and the second cohort as an experimental group. The control group sat the examination without any prior knowledge of the marking criteria, and the experimental group was given a marksheet before the examination that contained the marking criteria. There was a significant difference (p < 0.001) between the examination grades of the experimental and control group. The mean examination grades achieved were 55.4% and 36.9% for the experimental and control group, respectively. Subsequent focus groups revealed that the experimental group considered that they were much better prepared and equipped to revise for the examination, and the marksheet encouraged self‐reflection on their progress. The experimental group reported that they felt they had more control over preparation for the examination and higher levels of confidence in taking the examination.  相似文献   

9.
Research on the benefits of visual learning has relied primarily on lecture‐based pedagogy, but the potential benefits of combining active learning strategies with visual and verbal materials on learning anatomy has not yet been explored. In this study, the differential effects of text‐based and image‐based active learning exercises on examination performance were investigated in a functional anatomy course. Each class session was punctuated with an average of 12 text‐based and image‐based active learning exercises. Participation data from 231 students were compared with their examination performance on 262 questions associated with the in‐class exercises. Students also rated the helpfulness and difficulty of the in‐class exercises on a survey. Participation in the active learning exercises was positively correlated with examination performance (r = 0.63, P < 0.001). When controlling for other key demographics (gender, underrepresented minority status) and prior grade point average, participation in the image‐based exercises was significantly correlated with performance on examination questions associated with image‐based exercises (P < 0.001) and text‐based exercises (P < 0.01), while participation in text‐based exercises was not. Additionally, students reported that the active learning exercises were helpful for seeing images of key ideas (94%) and clarifying key course concepts (80%), and that the image‐based exercises were significantly less demanding, less hard and required less effort than text‐based exercises (P < 0.05). The findings confirm the positive effect of using images and active learning strategies on student learning, and suggest that integrating them may be especially beneficial for learning anatomy. Anat Sci Educ 10: 444–455. © 2017 American Association of Anatomists.  相似文献   

10.
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11.
The purpose of this research is to explore the dynamics of cortisol regulation in the context of center-based child care by examining the impact of social context (large classroom vs. small group) and relationship quality with caregivers (conflict with mothers and teachers). We extend the research on children's physiologic stress system functioning in center-based child care by focusing on morning cortisol levels among young children living in poverty. While in high-quality center-based child care, children's cortisol levels decreased over the course of the morning—a result that contrasts with findings in previous research with middle-class children, for whom cortisol typically increased over the course of the day while attending center-based child care. Cortisol levels were further reduced when children were moved from a large classroom environment to a small group context. Relationship conflict with mothers and teachers moderated these effects. Children who had high conflict with their mother exhibited cortisol levels that remained higher (decreased less) over the course of the morning, and children who had high conflict with their teacher exhibited cortisol levels that remained higher (decreased less) in response to the small group context. These results indicate that high-quality child care has the potential to support reduced stress among children living in poverty, at least as indicated by adrenocortical activity.  相似文献   

12.
The present study sought to evaluate the effects of a reading strategy instructional program on the reading competence of third‐grade students. Students were instructed in fluent and strategic reading by trained research assistants in whole class settings and subsequently worked on expository text material together with peers. Their reading competence was assessed continuously: in the baseline phase prior to the intervention (4 times), while the intervention was in place (8 times), and after the end of the intervention (4 times). Additionally, reading competence in the wait list control students was assessed 8 times during the same time period. Accordingly, within‐ and between‐group comparisons of students’ test scores were conducted on the data, with both resulting in significant positive effects on the reading competence of intervention students. This research provides an example of how to strengthen the validity of quasiexperimental intervention research through the addition of design features like multiple measurement points.  相似文献   

13.
Children chronically exposed to stress early in life are at increased risk for maladaptive outcomes, though the physiological mechanisms driving these effects are unknown. Cortisol reactivity was tested as a mediator of the relation between prenatal substance exposure and/or early adversity on adaptive and maladaptive outcomes. Data were drawn from a prospective longitudinal study of prenatal substance exposure (N = 860). Cortisol reactivity was assessed at age 11. Among African Americans, prenatal substance exposure exerted an indirect effect through early adversity and cortisol reactivity to predict externalizing behavior, delinquency, and a positive student–teacher relationship at age 11. Decreased cortisol reactivity was related to maladaptive outcomes, and increased cortisol reactivity predicted better executive functioning and a more positive student–teacher relationship.  相似文献   

14.
The association between child temperament characteristics and total diurnal saliva cortisol in 84 children (M = 2.3 years, SD = 0.6) attending out-of-home, center-based child care and 79 children (M = 2.0 years, SD = 0.5) attending at-home parental care was examined. Saliva samples were collected during two consecutive days, that is, Sunday and Monday, with four samples taken per day. While children higher in surgency had higher total diurnal cortisol production, we did not find evidence that temperament moderated the associations between child-care context and total diurnal cortisol. Negative affectivity and effortful control were not related to cortisol output. Our findings suggest that temperamental surgency may be associated with higher total cortisol production in early childhood across child-care settings.  相似文献   

15.
Abstract Previous studies have shown that prior discussion, or the provision of context, both decrease oral reading errors and increase self‐correction amongst low‐progress and mentally retarded readers. This study investigated the effects of prior provision of context upon the reading behaviour of an above average reader. The results indicate that discussion of context (through examination of the relevant illustrations, asking and answering questions, and the verbal introduction of some new words in the text) both significantly decreased errors, and slightly increased the amount of self‐correction for this subject.  相似文献   

16.
高考预选考试是指对参加高考的考生预先进行的筛选考试,只有通过预选才能报名参加高考,是考生参加高考的资格考试,最初出现时间是1977年。高考预选可以减少参加高考的人数、减轻组织和实施高考的工作量。实行预选的省份通常按高考计划录取数的三至五倍确定预选数,指标分配问题和考试组织问题是高考预选面临的两大问题。预选制度的推行是20世纪80年代高考报名人数下降和录取率波动的主要原因。随着招生人数的扩大、报考人数的稳定、毕业会考的推行和招生条件的改善,预选制度逐渐失去了存在的必要,并最终退出了历史舞台。作为一种应急的权宜措施,高考预选考试制度的出现有其特定的历史背景,也曾起过积极的作用。办人民满意的高考和选拔拔尖创新人才是当前高考改革面临的两难问题,高考预选的过往能够为兼顾二者提供一些启示。  相似文献   

17.
High stakes examinations have been identified as a significant source of stress for secondary school students; however, there is little data accounting for, and explaining, the experiences of examination stress. This study aimed to further the understanding of examination stress in secondary school students by conducting interviews with 34 students in their final two years of compulsory schooling in England, following a programme of study towards their school leaving qualification, the General Certificate of Secondary Education. Findings suggested that the appraisal of examinations as stressful was idiosyncratic, differing from one student to another. Eight distinct but related elements of examination stress were identified, which included the anticipation of failure, poor competence beliefs and the extent to which academic credentials are valued. Examination stress was also gendered, both in its subject‐specific nature and in the way the experience was described by students.  相似文献   

18.
辽宁2010年新课程高考具有稳定性和导向性,试题稳中求变具有创新性。建议2011年应做到一轮复习有宽度,二轮复习有方向,三轮复习有高度;复习中教师做到精读考纲,研究高考试题,反思总结,培养能力。  相似文献   

19.
Previous studies have shown that anatomy students who complete oral laboratory presentations believe they understand the material better and retain it longer than they otherwise would if they only took examinations on the material; however, we have found no studies that empirically test such outcomes. The purpose of this study was to assess the effectiveness of oral presentations through comparisons with other methods of assessment, most notably, examination performance. Specifically, we tested whether students (n = 256) performed better on examination questions on topics covered by their oral presentations than on other topics. Each student completed two graded, 12‐minute laboratory presentations on two different assigned topics during the course and took three examinations, each of which covered a third of the course material. Examination questions were characterized by type (memorization, pathway, analytical, spatial). A two‐way repeated measures analysis of variance revealed that students performed better on topics covered by their presentations than on topics not covered by their presentations (P < 0.005), regardless of presentation grade (P > 0.05) and question type (P > 0.05). These results demonstrate empirically that oral presentations are an effective learning tool. Anat Sci Educ 2: 260–264, 2009. © 2009 American Association of Anatomists.  相似文献   

20.
A multiple baseline research design across subjects (pairs) was used to examine the effectiveness of peer tutoring in reading using the Pause, Prompt and Praise tutoring procedure. Twelve 11 year‐old, Year 6 students of varying reading ability were trained in the systematic use of delayed attention, prompting and praise to tutor 12 Year 6 students of a similar age and similar reading ability. Individual trends in tutor behaviours were examined using a statistical programme specifically designed for analysing data from interrupted time series research designs. A one‐tailed t‐test was also computed to test for significant differences in pre‐ and post‐test means in reading achievement. Continuous data collection throughout the programme indicated that all peers were effective in increasing their use of the tutoring behaviours; not all tutors experienced statistically significant increases, however. Both peer tutors and tutees made statistically significant gains in reading accuracy and comprehension over the course of the intervention.  相似文献   

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