圆周上的范德瓦尔登数

The big upper bound of typical van der Waerden number was investigated through calculating the van der Waerden number on a circle. And the van der Waerden number Wh (3,3) = 9, Wh (3,3,3)≥25 on a circle was calculated by computer.     

Perception of sign language and its application to visual communications for deaf people

Video communication systems for deaf people are limited in terms of quality and performance. Analysis of visual attention mechanisms for sign language may enable optimization of video coding systems for deaf users. Eye-movement tracking experiments were conducted with profoundly deaf volunteers while watching sign language video clips. Deaf people are found to fixate mostly on the facial region of the signer to pick up small detailed movements associated with facial expression and mouth shapes. Lower resolution, peripheral vision is used to process information from larger, rapid movements of the signer in the video clips. A coding scheme that gives priority to the face of the signer may be applied to improve perception of video quality for sign language communication.     

Curriculum Design of a Flipped Classroom to Enhance Haematology Learning

A common trend in higher education is the “flipped” classroom, which facilitates active learning during class. The flipped approach to teaching was instituted in a haematology ‘major’ class and the students’ attitudes and preferences for the teaching materials were surveyed. The curriculum design was explicit and involved four major components (1) the preparation of the students; (2) the weekly pre-class work; (3) the in-class active learning strategies and (4) closing the learning loop using formative quizzes. Each of these components is discussed in detail and was informed by sound pedagogical strategies. Several different sources of information and several freely available software tools to engage the students are discussed. Two iterations are reported here, with improved pass rate for the final examination from 47 to 48 % in the traditional class to 56–65 % in the flipped classroom approach. The majority of students (93 and 89 %) came to the class prepared, after viewing the screencasts and engaged fully with the activities within the face-to-face time. The students perceived that solving case studies (93 %) was the most beneficial activity for their learning and this was closely followed by the production of essay plans (71 %). The majority of students recommended that this approach be repeated the following year (69 and 75 %).     

A Methylome‐Wide Association Study of Trajectories of Oppositional Defiant Behaviors and Biological Overlap With Attention Deficit Hyperactivity Disorder

In 671 mother–child (49% male) pairs from an epidemiological birth cohort, we investigated (a) prospective associations between DNA methylation (at birth) and trajectories (ages 7–13) of oppositional defiant disorder (ODD), and the ODD subdimensions of irritable and headstrong; (b) common biological pathways, indexed by DNA methylation, between ODD trajectories and attention deficit hyperactivity disorder (ADHD); (c) genetic influence on DNA methylation; and (d) prenatal risk exposure associations. Methylome‐wide significant associations were identified for the ODD and headstrong, but not for irritable. Overlap analysis indicated biological correlates between ODD, headstrong, and ADHD. DNA methylation in ODD and headstrong was (to a degree) genetically influenced. DNA methylation associated with prenatal risk exposures of maternal anxiety (headstrong) and cigarette smoking (ODD and headstrong).     

Child Development and the Social Demography of Childhood

This article provides background information and a practical guide for including demographic information in developmental research. First, it portrays historic demographic trends reflecting critical ways in which the family and economic environments of children have been, and continue to be, transformed in the United States. Second, it presents current demographic statistics to provide a basis for researchers to compare their special study population to the general population of children and to formulate specific hypotheses about ways in which their result might differ for children in various demographic situations. Third, it offers an Appendix with standardized wording for a minimum set of questions needed to measure the demographic characteristics and environments of children. The Appendix provides researchers the technical capacity to collect such data, so they can develop and test hypotheses about how family and econmic environments shape child development processes and outcomes.     

Correlates of Work-Life Balance for Faculty Across Racial/Ethnic Groups

Very few studies have examined issues of work-life balance among faculty of different racial/ethnic backgrounds. Utilizing data from Harvard University’s Collaborative on Academic Careers in Higher Education project, this study examined predictors of work-life balance for 2953 faculty members from 69 institutions. The final sample consisted of 1059 (36%) Asian American faculty, 512 (17%) African American faculty, 359 (12%) Latina/o faculty, and 1023 (35%) White/Caucasian faculty. There were 1184 (40%) women faculty and 1769 (60%) men faculty. The predictors of worklife balance included faculty characteristics, departmental/institutional characteristics and support, and faculty satisfaction with work. While African American women faculty reported less work-life balance than African American men, the reverse was true for Latina/o faculty. In addition, White faculty who were single with no children were significantly less likely to report having work-life balance than their married counterparts with children. Faculty rank was a significant positive predictor of work-life balance for all faculty. Notably, the findings highlight the importance of department and institutional support for making personal/family obligations and an academic career compatible. Institutional support for making personal/family obligations and an academic career compatible was consistently the strongest positive predictor of perceived work-life balance for all faculty. In addition, satisfaction with time spent on research had positive associations with work-life balance for all faculty, highlighting how faculty from all racial/ethnic backgrounds value being able to spend enough time on their own research.     

On mathematical understanding: perspectives of experienced Chinese mathematics teachers

Researchers have long debated the meaning of mathematical understanding and ways to achieve mathematical understanding. This study investigated experienced Chinese mathematics teachers’ views about mathematical understanding. It was found that these mathematics teachers embrace the view that understanding is a web of connections, which is a result of continuous connection making. However, in contrast to the popular view which separates understanding into conceptual and procedural, Chinese teachers prefer to view understanding in terms of concepts and procedures. They place more stress on the process of concept development, which is viewed as a source of students’ failures in transfer. To achieve mathematical understanding, the Chinese teachers emphasize strategies such as reinventing a concept, verbalizing a concept, and using examples and comparisons for analogical reasoning. These findings draw on the perspective of classroom practitioners to inform the long-debated issue of the meaning of mathematical understanding and ways to achieve mathematical understanding.     

Redefining the ResponsibiIities of Teachers and the Social Position of the Technical Communicator

As we increasingly recognize the social nature of technical communication, our responsibilities as teachers need to be redefined. Three levels of responsibility are suggested: at the theoretical level, we should study technical communication as a historically emergent social practice; at the pedagogical level, we need to incorporate social and historical perspectives into technical communication courses and curricula; at the level of social action, we should participate in defining and creating new sites of practice for technical communicators. Several suggestions are offered for helping students locate or develop alternative sites of technical communication practice.     

Perceived and Measured Needs Levels of Counselor Education Students

Because the counseling profession places high value on counselors possessing accurate self-awareness, this study investigated the differences and relationships between counselor education students' self-perceived and measured needs levels. A sample of 107 counselor students estimated their needs levels and then completed the Personality Research Form (PRF). Significant differences between their perceived and measured needs levels were found for 10 of the 14 PRF scales. Wide variations were evident in both perceived and measured needs levels. Significant correlations between perceived and measured needs levels percentiles for all 14 scales indicated consistency in over or under estimation of needs levels. Age and number of quarter hours completed were generally unrelated to accuracy of needs level estimation.     

Teacher capacity for and beliefs about data-driven decision making: A literature review of international research

Data-driven decision making continues to be a growing educational reform initiative across the globe. The effective use of data requires that teachers develop the knowledge and skills to analyze and use data to improve instruction. The purpose of this article is to examine teachers’ capacity for and beliefs about data use. These issues are examined through a review of research in the past decade. We find that teachers’ beliefs about and capacity for data use are often not connected within the literature or in practice, but we argue they are the heart of the connection between data and instructional change. Teachers’ capacity to use data and their beliefs about data use are shaped within their professional communities, in training sessions, and in their interactions with coaches, consultants, and principals. However, efforts to develop teachers’ capacity for data use often fall short of their goals. Correspondingly, teachers have varied beliefs about data use, and some feel they lack the ability to use data to inform instruction. In order to be more successful, capacity building should directly address teachers’ beliefs, and data use must be decoupled from external accountability demands and involve a variety of information on student learning.