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1.
There is very little data in world literature concerning the peculiarities of physical development of children in the high-latitude regions. In the meantime, such kinds of research is both of scientific and humanitarian interest. It is important to realize the specifics of growth of children living in the Arctic and sharp continental climate in view of the need to understand the biology of populations of extreme and sub-extreme regions. Such material would be of practical use for evaluation of fitness among children belonging to various ethnic groups of the north. The present paper is a sort of review of the data obtained by us in the course of research of growth and development of children in the northern regions of Russia undertaken since 1986. The whole bulk of material is too big and diverse to be presented in one single article. Part of the material is presented in the publication by A. Kozlov & G. Vershubsky (1999). Right now we shall talk only about age dynamics of body mass and mass-height index for children and teenagers from age 6 through 17.  相似文献   

2.

Objective

The aims of this study were to develop and assess a method to map language networks in children with two auditory fMRI protocols in combination with a dichotic listening task (DL). The method is intended for pediatric patients prior to epilepsy surgery. To evaluate the potential clinical usefulness of the method we first wanted to assess data from a group of healthy children.

Methods

In a first step language test materials were developed, intended for subsequent implementation in fMRI protocols. An evaluation of this material was done in 30 children with typical development, 10 from the 1st, 4th and the 7th grade, respectively. The language test material was then adapted and implemented in two fMRI protocols intended to target frontal and posterior language networks. In a second step language lateralization was assessed in 17 typical 10–11 year olds with fMRI and DL. To reach a conclusion about language lateralization, firstly, quantitative analyses of the index data from the two fMRI tasks and the index data from the DL task were done separately. In a second step a set of criteria were applied to these results to reach a conclusion about language lateralization. The steps of these analyses are described in detail.

Results

The behavioral assessment of the language test material showed that it was well suited for typical children. The results of the language lateralization assessments, based on fMRI data and DL data, showed that for 15 of the 17 subjects (88%) a conclusion could be reached about hemispheric language dominance. In 2 cases (12%) DL provided critical data.

Conclusions

The employment of DL combined with language mapping using fMRI for assessing hemispheric language dominance is novel and it was deemed valuable since it provided additional information compared to the results gained from each method individually.  相似文献   

3.
The purpose of this study was to explore how Dutch-speaking children acquire deverbal compounds, particularly in ordering verbs and nouns. English-speaking children form compounds like bottle breaker around 5–6 years of age and make noun-verb reversal errors at younger ages. These errors have been attributed to clausal ordering. Dutch allows more variations in clausal ordering, so Dutch-speaking children might acquire deverbal compounds differently from English-speaking children. In Study 1, we examined the input to a Dutch-speaking child between 4;8 and 5;2 and her compound acquisition. She heard a variety of clausal orderings, mostly with verbs before objects, and her deverbal compounds were already well acquired. In Study 2, we tested 24 Dutch-speaking preschool children’s production and comprehension of novel compounds. They produced many of the same forms as have been reported for English-speaking children, making reversal errors at around the same age. In Study 3, we compared a subset of the Dutch-speaking children with age-matched English monolingual children. We found a slight advantage for the Dutch-speaking children on production but no difference on comprehension. We argue that children’s ordering errors with OV-er compounds are not due to clausal word order but to ordering of other complex word forms.  相似文献   

4.
目的:探讨7-9岁高功能自闭症儿童面孔加工时事件相关电位(Electrical event-relateds,ERP)的变化及其意义。方法:选择7-9岁自闭症儿童(实验组)与普通儿童(对照组)各15名,以中国人中性面孔及常见物件为刺激材料,记录和比较两类儿童在面孔刺激下的脑电成分。结果:剔除无效数据后,有效被试:实验组12人、对照组14人,两组年龄和性别组成无显著性差异(P0.05)。而,自闭症组按键反应时间、面孔反应时间显著长于对照组(按键反应F=9.26,P0.05;面孔反应t=5.32,P0.05)。在面孔刺激因素下,自闭症组平均波峰明显小于对照组(t=4.62,P0.05)。在物件刺激因素下,两组平均波峰无显著差异(t=0.21,P0.05)。而两组的潜伏期组别主效应不显著(F=1.63,P0.05)。结论:自闭症儿童面孔结构编码过程异常,对面孔的关注度比普通儿童低。本文证实了自闭症儿童知觉/认知缺陷的存在,为更进一步研究提供了理论依据。  相似文献   

5.
Chan S  Quigley M 《Bioethics》2007,21(8):439-448
Recent ethical and legal challenges have arisen concerning the rights of individuals over their IVF embryos, leading to questions about how, when the wishes of parents regarding their embryos conflict, such situations ought to be resolved. A notion commonly invoked in relation to frozen embryo disputes is that of reproductive rights: a right to have (or not to have) children. This has sometimes been interpreted to mean a right to have, or not to have, one's own genetic children. But can such rights legitimately be asserted to give rise to claims over embryos? We examine the question of property in genetic material as applied to gametes and embryos, and whether rights over genetic information extend to grant control over IVF embryos. In particular we consider the purported right not to have one's own genetically related children from a property‐based perspective. We argue that even if we concede that such (property) rights do exist, those rights become limited in scope and application upon engaging in reproduction. We want to show that once an IVF embryo is created for the purpose of reproduction, any right not to have genetically‐related children that may be based in property rights over genetic information is ceded. There is thus no right to prevent one's IVF embryos from being brought to birth on the basis of a right to avoid having one's own genetic children. Although there may be reproductive rights over gametes and embryos, these are not grounded in genetic information.  相似文献   

6.
In this contribution, we address a major puzzle in the evolution of human material culture: If maturing individuals just learn their parental generation's material culture, then what is the origin of key innovations as documented in the archeological record? We approach this question by coupling a life‐history model of the costs and benefits of experimentation with a niche‐construction perspective. Niche‐construction theory suggests that the behavior of organisms and their modification of the world around them have important evolutionary ramifications by altering developmental settings and selection pressures. Part of Homo sapiens' niche is the active provisioning of children with play objects — sometimes functional miniatures of adult tools — and the encouragement of object play, such as playful knapping with stones. Our model suggests that salient material culture innovation may occur or be primed in a late childhood or adolescence sweet spot when cognitive and physical abilities are sufficiently mature but before the full onset of the concerns and costs associated with reproduction. We evaluate the model against a series of archeological cases and make suggestions for future research.  相似文献   

7.
Using a sample of men living in Albuquerque, NM, we examined the relationship between paternity confidence and men's investment in children. In humans, men may reduce their investment in a child in two ways: indirectly, by ending their relationship with the child's mother and ceasing to cohabit with the child (e.g., divorce), and directly, by allocating less time and fewer resources to the child. In this article, we tested two hypotheses regarding the effect of paternity confidence on investment in children: (1) men will be more likely to divorce women if they suspect or are sure that they are not the father of their wife's child, and (2) controlling for divorce, men will reduce direct investments in low paternity confidence children relative to high paternity confidence children. The first hypothesis was supported by the data. The second hypothesis was supported for two out of three measures of paternal investment we examined; low paternity confidence reduces the time men spend with a child in a group with other children or adults, and it reduces extensive involvement with the child's educational progress; there was no effect of paternity confidence on the amount of time men spend with children in one-on-one interactions. We also examined the effects of unstated paternity confidence (e.g., when men decline to answer the question) on divorce and paternal investment. Overall, the results suggested that paternity confidence plays an important role in shaping men's relationships with women and with their putative genetic children.  相似文献   

8.
Research indicates that in experimental settings, young children of 3–7 years old are unlikely to devise a simple tool to solve a problem. This series of exploratory studies done in museums in the US and UK explores how environment and ownership of materials may improve children''s ability and inclination for (i) tool material selection and (ii) innovation. The first study takes place in a children''s museum, an environment where children can use tools and materials freely. We replicated a tool innovation task in this environment and found that while 3–4 year olds showed the predicted low levels of innovation rates, 4–7 year olds showed higher rates of innovation than the younger children and than reported in prior studies. The second study explores the effect of whether the experimental materials are owned by the experimenter or the child on tool selection and innovation. Results showed that 5–6 year olds and 6–7 year olds were more likely to select tool material they owned compared to tool material owned by the experimenter, although ownership had no effect on tool innovation. We argue that learning environments supporting tool exploration and invention and conveying ownership over materials may encourage successful tool innovation at earlier ages.  相似文献   

9.
Chalcogenide and chalcopyrite photovoltaic (PV) technologies are highly suitable for solar energy conversion because of their high efficiency, long‐term stable performance, and low‐cost production. However, the absorber materials that are used, such as indium, gallium, and tellurium, are regarded as critical, and their limited availability can hinder market expansion. Therefore, we assess how material efficiency measures along the PV module's life cycle can reduce the net material demand of the absorber materials and thus the material costs. In order to estimate the material flows, we developed a closed‐loop model for the life cycle representing the phases module production, module collection, module recycling, and refinement. In order to reflect the variety and uncertainty in each phase, we compose three different efficiency scenarios by varying material efficiency measures on process and product levels. For each scenario, we compute the life cycle material costs based on the computed material flows. The results show that, in the long term, the material demand can be reduced down to one fourth of the required feedstock for module manufacturing; that is, three fourths of the absorber material stays in the life cycle in a very efficient scenario. Thus, total material costs along the life cycle could be significantly reduced, because the costs for material recycling are lower than the costs for “new” technical‐grade material. This reduction in life cycle material costs means that cadmium telluride– and copper indium gallium diselenide–PV can still be financially viable even if the price of the absorber materials increases significantly. Hence those technologies will still be competitive against crystalline silicon PV in the mid to long term.  相似文献   

10.
Summary The ABO blood group distribution among 1284 first-born children is compared with the frequency of the blood groups among 2388 later-born children. Among the later-born children the blood group O is more frequent, whereas the blood groups B and AB are rarer. From the fifth child on both the increase of the blood group O and the decrease of the groups B and AB become more evident. The total frequency of boys is practically the same both in the different blood groups and in the sum of all first and later-born children. Within the blood group O, however, boys are predominating among the first-born children, but are less numerous among the later-born children. Within the blood group AB on the contrary there is a lack of boys among the first-born children and an excess of boys among the later-born children. The same distribution but to a smaller extent might be found within the blood group B among a not selected material. In the same way the change of the sexual distribution seems to rise with the increasing number of children, as it appears from the rate from the fifth child onward.

(Ärztl. Leiter: Prim. Dr. W. Kircher)  相似文献   

11.
In very young children, immature control of posture and gait results in unsteady locomotion. In children of approximately 3 yr of age, gait appears relatively mature; however, it is unknown whether the dynamics of walking change beyond this age. Because stride dynamics depend on neural control, we hypothesized that motor control would continue to develop beyond age 3. To test this hypothesis, we measured the gait cycle duration on a stride-by-stride basis in 50 healthy 3- to 14-yr-old children (25 girls). Measurements of stride-to-stride variability were significantly larger both in the 3- and 4-yr-old children, compared with the 6- and 7-yr-old children, and in the 6- and 7-yr-old children, compared with the 11- to 14-yr-old children. Measurements of the temporal organization of gait also revealed significant age-dependent changes. The effects of age persisted even after adjusting for height. These findings indicate that mature stride dynamics may not be completely developed even in healthy 7-yr-old children and that different aspects of stride dynamics mature at different ages.  相似文献   

12.
Children respond positively to individuals who favor them and also to individuals who are fair. The present studies examine the interaction between these two preferences by presenting children with two distributors who share resources with the child participant and another recipient. Children are asked whom they like better: the distributor who was unfair but favored the child participant or the distributor who was fair and showed no (or reduced) favoritism. In Study 1, we find that when fairness and favoritism are in conflict, children are split on whom they prefer. In Study 2, we find that placing children in a competitive context leads to a stronger preference for the distributor who favored the child participant. In Study 3, we examine whether children's preference for favoritism persists when both distributors gave the child the same number of rewards, but one distributor gave the child participant relatively more than the other recipient. In this situation, we find that children prefer the fair distributor. However, we again find that creating a competitive context reduces children's preference for the fair distributor. Finally we find that in a third-party context, children value fairness over generosity. Taken together, these results show how children balance competing concerns for fairness and favoritism.  相似文献   

13.
目的:探讨7-9岁高功能自闭症儿童面孔加工时事件相关电位(Electrical event-relateds,ERP)的变化及其意义。方法:选择7-9岁自闭症儿童(实验组)与普通儿童(对照组)各15名,以中国人中性面孔及常见物件为刺激材料,记录和比较两类儿童在面孔刺激下的脑电成分。结果:剔除无效数据后,有效被试:实验组12人、对照组14人,两组年龄和性别组成无显著性差异(P〉0.05)。而,自闭症组按键反应时间、面孔反应时间显著长于对照组(按键反应F=9.26,P〈0.05;面孔反应t=5.32,P〈0.05)。在面孔刺激因素下,自闭症组平均波峰明显小于对照组(t=4.62,P〈0.05)。在物件刺激因素下,两组平均波峰无显著差异(t=0.21,P〉0.05)。而两组的潜伏期组别主效应不显著(F=1.63,P〉0.05)。结论:自闭症儿童面孔结构编码过程异常,对面孔的关注度比普通儿童低。本文证实了自闭症儿童知觉/认知缺陷的存在,为更进一步研究提供了理论依据。  相似文献   

14.
In studies on the psychology of memory, it has long been established that the principal segments, in terms of content, of logically coherent material are recalled best [3, 7, 8, 18]. This phenomenon was first described by A. Binet & V. Henri in a study published in 1895. On the basis of experiments with children 9-12 years old, they concluded that "The essential parts of a story were remembered much better than the rest" [19. P. 36].  相似文献   

15.
In adults, sleep is necessary for the offline improvement of certain skills, such as sequential finger tapping, but whether children show a similar effect is still debatable. Here, we tested whether sleep is associated with offline performance improvement in children. Nine- and 11-year-old children trained on an explicit sequential finger tapping task. On the night following training, their parents observed and recorded the duration of each child’s sleep. The following day, all children performed a surprise retest session on the previously trained sequence. In both 9- and 11-year-old children, skill performance was significantly improved during the first retest session relative to the end of training on the previous day, confirming the offline improvement in performance. There was a significant correlation between the degree of improvement and sleep duration the night after training, suggesting that in children, as in adults, sleep is associated with offline skill enhancement.  相似文献   

16.
The practice of using children''s human figure drawings (HFDs) to assess their intellectual ability is pervasive among psychologists and therapists in many countries. Since the first systematic scoring system for HFDs was published in 1926, their continued popularity has led to the development of several revised versions of the test. Most recently, the Draw-A-Person Intellectual Ability Test for children, adolescents, and adults (DAP:IQ) was published. It is the most up-to-date form of HFD test designed to assess intellectual functioning across a wide age range. In the present study, we assessed the validity of the DAP:IQ as a screening measure of intelligence in both children and adults. In Experiment 1, 100 4- to 5-year-old children completed the DAP:IQ and the Wechsler Preschool and Primary Scale of Intelligence-Third Edition. In Experiment 2, 100 adults completed the DAP:IQ and the Wechsler Abbreviated Scale of Intelligence. In both experiments, we found only weak to modest correlations between scores on the DAP:IQ and the Wechsler tests. Furthermore, when we compared individual''s scores on the two tests, the DAP:IQ yielded high false positive and false negative rates when screening for borderline and superior intellectual functioning. Based on these findings, and based on the lack of validity of previous HFD tests, we conclude that practitioners should not rely on HFD tests as a projective measure of intelligence.  相似文献   

17.
Background. The aims of our study were twofold. First, we sought to evaluate in symptomatic children the influence of the Helicobacter pylori genotype on gastritis, abdominal pain, and circulating anti– H. pylori IgG antibodies (anti– H. pylori IgG) or pepsinogen A (PGA) and C (PGC). Additionally, we sought to assess anti– H. pylori IgG, PGA, and PGC patterns in a large cohort (N = 921) of asymptomatic children.
Materials and Methods. In 183 symptomatic children, H. pylori infection and the presence of gastritis were evaluated by histology. In a subgroup of 20 H. pylori –positive children, the H. pylori genotype was evaluated also by polymerase chain reaction. Nine hundred and twenty-one asymptomatic children, aged 11 to 14 years, were studied by anti– H. pylori IgG, PGA, and PGC serum determination.
Results. The infection was found in 33 of 183 symptomatic children; among the 20 H. pylori –positive children for which the H. pylori genotype was available, cag A was present or absent in equal percentages. H. pylori infection was associated with more severe gastritis and higher serum levels of anti– H. pylori IgG and PGC but not with abdominal pain. In infected children, higher levels of anti– H. pylori IgG and the presence of abdominal pain were associated with infections caused by cag A-positive strains. In the cohort of 921 asymptomatic children, raised levels of anti– H. pylori IgG, PGA, and PGC were found in approximately 5% of the cases.
Conclusions. Infection with cag A-positive H. pylori strains can be associated with increased frequency of reported abdominal pain and higher circulating levels of anti– H. pylori IgG. The serological assessment of H. pylori IgG using H. pylori antigens containing significant amounts of cagA protein may, therefore, underestimate the true prevalence of infection.  相似文献   

18.
We describe a computer-based method for the special education of deaf children in their stage of expanding an initial vocabulary; the method uses a symbolic keyboard to facilitate real-time communication between the deaf child and the machine. The lack of auditory feedback is partially compensated by using visual and propioceptive sensorial modalities as alternative representations of words and concepts. To illustrate the use of the computer with display and symbolic keyboard we comment on a program for the teaching of spatial relationships. The same method is used in teaching the structure of sentences and other conventional educational material such as Geography and Physics.  相似文献   

19.
This study investigates the incidence of periodontitis in a Mycenaean population unearthed at the cemetery of Aghia Triada (West Peloponnese, Greece) during the 1989–1997 field season. The material consists of 172 dry skulls. Demographic parameters of sex and age were difficult to be assigned due to the bad state of preservation of the skeletal material. The ratio was 50 males, 48 females, 65 unidentified and 9 children, and we estimated an average age of 38 years. In this work we used traditional and modern methods to determine the incidence of periodontitis in the archeological human dental bone. We also recorded other dental diseases, such as ante mortem tooth loss, caries and attrition. The results showed that periodontitis has affected 35% of the jaws. A notable percentage of the individuals — 24% — lost three or more teeth during their lifetime and a total 53% of the population had extracted teeth before death. This paper points out that the ancient jaws present a high proportion of ante-mortem tooth loss, attrition and deep caries, whereas the frequency of periodontitis does not seem to differ from that of other prehistoric samples.  相似文献   

20.
The dimensions of the living and working space and buildings, the types of material and different riggings should be designed to conform to the users' anthropometric measures. The first requirement to design on ergonomic system is to measure the human being who will work and live in that system. Because of this, anthropometric measures are the most frequently used ergonomic data during the design process. In this research paper, we attempt to organize a new data base of anthropometric data to use in the design of children's equipment and furniture used in crèches. A starting point for research on the proper dimensions of creche furniture is to investigate how the dimensions of furniture reflect the body dimensions and the functional needs of the children using furniture. The anthropometric data of 3, 4 and 5 year-old-children in crèches was used. We report the results of the measurements of 18 anthropometric characteristics of children which constitute a set of basic data for the design of functional spaces and furniture.  相似文献   

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