Development of Lower Extremity Kinetics for Balance Control in Infants and Young Children

Developmental changes in the kinematics and kinetics underlying balance control were studied in 61 children, 9 months to 10 years of age. The children were classified according to developmental milestones as standers; new, intermediate, and advanced walkers; runners-jumpers; hoppers; gallopers; and skippers. The children experienced support-surface translations of varying size and speed. Children with greater locomotor experience withstood larger balance threats without collapsing or stepping. Analyses of scaled trials (perturbations normalized in size to foot length and center of gravity height) revealed that improvement in balance was not related to initial configuration parameters surrounding the task (degree of crouch or lean). Children with advanced locomotor skills had faster recovery times and relatively larger muscle torques than children with less experience. Relative torque-time histories of the more experienced children began to match the adult response to similar perturbations. With increased experience and changing muscle torque regulatory abilities, balance skills became more robust.     

从神经可塑性的视角看压力与疾病的关系

压力致病是一个复杂的过程,涉及到与多种致病因素的相互作用、多个器官系统的激活和反馈、不同发育阶段对疾病的易感性等。这个过程中,神经可塑性起着重要的调节作用。本文以神经可塑性为切入点,阐述了压力、发育阶段、个人发展、疾病发生之间的关系。     

Interaction Between the Development of Postural Control and the Executive Function of Attention

The authors examined the interaction between the development of postural control and the development of the executive function of attention in 13 children and 6 adults in dual-task conditions. Participants performed an attentionally demanding cognitive task and a postural task simultaneously. The authors equalized the attentional load of the cognitive task across age groups. Comparative changes in the center of pressure in dual- and single-task conditions indicated that dual tasks interfered with postural performance in the wide stance (WS) and the modified Romberg stance (RS). Children at 4-6 years of age (but not children at ages 7-12 years of age or adults) experienced postural control interference in both stance positions, but interference was greater in the RS (p = .018). For all participants, cognitive task performance in RS was unchanged from that in WS. The knowledge gained from the results of this study will contribute to the design and implementation of academic and preacademic programming for young children. Their performance of an intentionally demanding cognitive task would be enhanced by the provision of appropriately sized desks and chairs or their use of an alternate, less demanding position.     

In Search of a Reconciliation Between Semiotics,Thermodynamics and Metasystem Transition Theory

The disciplines of cybernetics, semiotics and thermodynamics investigate evolutionary processes quite independently from each other. The aim of this paper is to draw the parallels and point out the possibility and necessity of a reconciliation between these disciplines. The concept of metasystem transition has been proposed by Turchin as a quantum of evolution from a cybernetic point of view. Semiotic processes are of prime importance for the realisation of metasystem transitions in the course of evolution. From a thermodynamic point of view, the emergence of more complex, self-producing agents depends on the emergence of more advanced forms of semiosis. As an evolutionary consequence, more symbolic forms of semiosis that allow higher competence for abstraction and anticipation emerge.     

血管外科治疗进展与科技发展的关系

血管外科在近几十年日益发展成熟,并逐渐从普外科分离出来成为单独发展的学科。在科技发展日新月异的新世纪,新技术新材料的应用也推动着血管外科诊疗手段的突飞猛进。这就要求从事血管外科的医务工作者在临床工作中要树立科技发展观的意识,及时了解科技前沿的发展动态,用新技术新方法改善治疗效果,最大程度地减少患者的痛苦和提高患者的生活质量,促进人类健康生存和发展。     

From Ages 27 to 72: Career and Personal Development of a Productive Counselor Over the Life Span

Interviews of productive counselors usually do not capture their adult life span in depth. This article examines the life of a prolific counselor over 5 decades in context and through the theories of personal and career development formulated by Erikson ( 1994 ) and Super ( 1980 ). It looks biographically at his life and its challenges as well as resolutions to difficulties he faced in the process. Lessons that have universal application are highlighted.     

不同强度的痛觉刺激对内、外倾者心率、T波幅度影响的初步研究

本文旨在探讨内、外倾者在三种不同强度痛觉刺激下心率、T波幅度的变化。通过艾森克个性问卷筛选出15名内倾者和15名外倾者,以8mA、12mA、16mA的电流引起痛觉。实验结果表明,刺激后30秒内．在12mA、16mA痛觉刺激下．内倾组心率反应值与基础值差异显著．外倾组差异不显著;在12mA刺激下．内、外倾组心率变化差异显著。从心率变化上看。两组被试对痛觉刺激均表现出适应,内倾组的适应速度比外倾组慢。在各强度痛觉刺激条件下．二组T波幅度均未随刺激量增大发生显著变化。本实验表明,心脏T波幅度对痛刺激不敏感。     

Development of Postural Adjustment During Gait Initiation: Kinematic and EMG Analysis

The authors studied the development of postural adjustments associated with the initiation of gait in children by using kinematic and electromyographic (EMG) analysis. Participants (N = 28) included infants with 1-4 and 9-17 months of walking experience, children 4-5 years of age, and adults. Anticipatory postural adjustments (APA) were present in the youngest age groups, including a clear anticipatory lateral tilt of the pelvis and the stance leg, which enabled the child to unload the opposite leg shortly before its swing phase. An anticipatory activation of the hip abductor of the leg in stance phase prior to heel-off was found, suggesting pelvis stabilization. APA did not appear consistently until 4-5 years of age. A decrease in segmental oscillations occurred across the ages, indicating better control of intersegmental coordination in the frontal and sagittal planes during the postural phase of gait initiation. Young walkers presented APA involving movements of both the upper and the lower parts of the body, whereas, like adults, 4- to 5-year-olds were able to laterally shift only the pelvis and the stance leg. The oldest children and the adults also showed lower activation levels of hip and knee muscles but higher activation at the ankle level. Those kinematic and EMG results taken together suggest a clear developmental sequence from an en bloc operation of the body through an articulated operation with maturation, walking experience, or both.     

The Dialectic Relationship Between the Shared Values of Humanity and a Human Community with a Shared Future

General Secretary Xi Jinping deeply grasps the overall strategic situation of the great rejuvenation of the Chinese nation and great changes in the world unseen in a hundred years, and forms the important thought of carrying forward the shared values of humanity of peace, development, fairness, justice, democracy, and freedom and promoting the building of a human community with a shared future. The shared values of humanity provide value basis for the community, confirm the morality of the community, and lay the foundation of value recognition for building the community. A human community with a shared future is the practice area for the shared values of humanity, providing it with a real subject and delimiting the boundaries of the times. The shared values of humanity and a human community with a shared future complement each other, and are dialectically unified in the planning and grasp of the “two overall situations,” i.e., the overall strategic situation of the great rejuvenation of the Chinese nation and great changes in the world unseen in a century．     

Balance of blood pressure equivalents as a new quantitative scale for identifying cardiac versus vascular reactor: Comparisons with Gregg, Matyas and James' (2002) hemodynamic profile scale

Abstract:  A quantitative scale for identifying cardiac versus vascular reactor, balance of blood pressure equivalents ( BE ), was newly advocated and compared with a very recently advocated one, hemodynamic profile ( HP ), by Gregg, Matyas and James (2002). BE was defined as " (Δ Q/Q ₀) P ₀'  − ( Δ R/R ₀ )P ₀." Here, P ₀ , Q ₀, and R ₀ were mean blood pressure ( P ), cardiac output ( Q ), and total peripheral resistance ( R ) during baseline, and Δ Q and Δ R were the difference scores of Q and R from baseline to stress, respectively. This was named as BE because the two terms in the formula indicated changes in Q and R in their blood pressure equivalents. Comparisons of the BE and HP scales were carried out, theoretically, in a newly introduced pressor space, on orthogonality with the extent of elevation of P (Δ P ); and then, practically, by using hypothetical data. In summary, it was shown that data points in the neighborhood in the pressor space can be judged as having not so different hemodynamic balance whether the BE or HP scale was used. As a merit, the BE scale seemed helpful to an intuitive understanding of the hemodynamics during stress. As a demerit, it cannot maintain the quasi-orthogonal relationship with Δ P when Q or R changes profoundly in the face of stress.     

Time and Its Relationship to Development in the Life Course: Some Reflections from a Study of HIV-Positive Adults

Although adult development is commonly understood as change over time, the relationship between time and development is rarely highlighted in research in the field. This paper first reviews 3 dimensions of time that interact in the study of developmental processes in the life course. The 3 dimensions are historical time; chronological age or life time; and social time, the culturally-specific, systematic ordering of life events. Second, the paper utilizes data from a follow-up study of HIV-positive men and women to illustrate the importance of time in development. In the original study, an HIV-positive diagnosis was viewed as a death sentence and had the effect of suspending the normal developmental patterns of adult life. Two years later, with the advent of protease inhibitors—an event in historical time—participants had reengaged with life time, once again making social time a relevant factor in their development. These data demonstrate how a better understanding of adult development can be achieved when historical time, life time, and social time are moved center stage in the study of developmental processes.     

Exploring the Relationship between Adolescent Activities and Choice of Graduate School Discipline: Implications for Creativity Development

The relationship between adolescent extra‐curricular activities and choice of graduate‐education field was examined among students from three fields of study, science (n = 12), art (n = 12), and education (n = 14), using qualitative and quantitative methods. Results of profile analysis indicated that the different majors participated in stereotypically varying activities when they were adolescents. Science majors generally participated in mathematics and science activities during adolescence. Art majors generally participated in theater and music activities, and education majors tended to have participated in social leadership and educational activities. Interviews with the participants supported these findings and provided a more comprehensive discussion of these tendencies. While in high school, the participants had many influences when determining a field of study. Using personal happiness as a guide, the participants chose activities and ultimately graduate‐level majors that reflected their interests. It was concluded that adolescent extra‐curricular activities are important in the development of interest in creatively talented individuals and may lead to graduate field selection.     

中国家庭中的亲子互动行为与儿童行为抑制性的发展

本研究采用家庭录像的方法对53名中国4岁儿童在家庭自由游戏和拼图游戏小与父母的交往行为进行了观察,并在这些儿童7岁时任实验室里的行为抑制性进行了录像观察,从而考察了在家庭自然环境中的亲子互动行为与儿童行为抑制性发展之间的关系。结果发现：在以上家庭录像的两个情境中,随着年龄的变化,母亲的控制行为越多,儿童抑制倾向的发展速度越快,作抑制倾向发展得越慢;儿童顺从行为越多,儿童的非抑制倾向发展得越慢,抑制倾向发展得越快。父母之间的情感表达越亲密,父亲在身体上对儿童的积极情感越多,儿童的非抑制倾向发展得越快。     

The Development of Symbolic Uses of Objects in Infants in a Triadic Context: A Pragmatic and Semiotic Perspective

In this study, we address the construction of the first symbolic uses of objects in contexts of triadic interaction (adult–child–object). We assume that symbolic productions are based on public rules of the use of objects previously agreed by the community. The first symbols are not rooted in any literal, evident reality, but in shared rules of uses about the material world. We observed six dyads communicating and interacting together with 10 objects in a semi‐structured situation longitudinally from 9 to 15 months of age. We found that the infants gradually constructed symbolic meanings, and we identified five symbolic levels and sublevels. At 9 months, the infants attended and engaged in the symbolic uses produced by an adult even though they themselves were not yet able to produce them. At 12 months, infants began to use objects symbolically to communicate with adults. The highest percentage of these first symbolic uses was of level 1, that is, with a close relation to the conventional use of the object used to perform the symbol. At 15 months, children increased their symbolic uses and performed symbolic uses at all levels, whereas adults reduced such practices. Adult semiotic mediation and the social meanings of objects can be considered important factors in children's symbolic productions. Copyright © 2014 John Wiley & Sons, Ltd.