On-the-Job Training: Prescriptions and Practice

This article discusses the status of workplace training in the United States, describes a model of how to conduct effective on-the-job training, and presents the results of a questionnaire based on a model designed to assess on-the-job training practices aboard Navy ships. The model views the on-the-job trainer as a coach who guides the trainee through a task using three steps: 1) assessment, 2) training, and 3) evaluation. The questionnaire was sent to over 5,000 shipboard supervisors; 2,321 responded. Results indicate that nearly 50% of the Navy supervisors who responded are not as effective as they could be. The implications of these findings for the civilian workplace are discussed.     

Teaching Instructional Design: An Apprenticeship Model

Several cognitive psychologists have written about the importance of placing instruction within “authentic” contexts that mirror real-life situations. They argue that knowledge learned in academic settings does not necessarily transfer to non-academic settings. Whether preparing performance technologists or instructional designers, educators must strive to create meaningful problem-solving contexts that enable students to define, and subsequently solve, real-world problems. In an attempt to address this issue we have modified the way we teach instructional design. This paper discusses a cognitive apprenticeship approach to teaching design, which incorporates elements of modeling, coaching, reflection, articulation, and exploration. We describe how these features are embedded within three phases (orientation, situated training/learning, and exploration) of an introductory instructional design course designed to move our novice designers along a continuum of expertise as they develop and refine their own professional design skills. Although the apprenticeship model described here specifically addresses concerns within the context of preparing instructional designers, we believe that this model can be adapted to address similar issues in the education of performance technologists.     

Wanted: An Effective Director

The role of museum director is increasingly discussed and reported inside and outside the museum community. Turnover grows as museum missions expand and funding sources and amounts decrease. Finding a new director who will be effective when confronted by these pressures requires a realistic assessment by the searching institution of the job to be done. That realistic assessment requires recognition — not necessarily agreement — by both staff and trustees of what the problems and priorities are. There is no perfect director. But there are effective directors. This essay addresses some of the issues facing boards, staffs, search firms, and candidates — as seen from the limited perspective of one person.     

一种在轨海上多运动舰船目标检测和跟踪方法

传统遥感卫星图像处理采用在地面进行目标检测和跟踪处理的模式,卫星将拍摄到的图像数据下传至地面数据处理中心,由地面数据处理系统对接收到的遥感图像数据进行目标检测和跟踪。然而,随着遥感图像分辨率的不断提高,需要下传的数据量增大,导致星地数据传输的时间大大增加,最终造成目标检测和跟踪的时效性降低。针对上述问题,提出一种基于多特征量判别的Canny边缘检测和联合概率数据关联的在轨海上多运动舰船目标检测和跟踪方法。将该方法利用中国科学院微小卫星创新研究院的高分微纳卫星实测数据在模拟星载的嵌入式开发平台上进行验证,结果表明该方法能够在轨对海上多运动舰船目标进行快速、准确的检测和跟踪。     

超高含水原油混合流动及初始沉积特性

使用自行设计的实验装置,对超高含水原油的流动特性和初始沉积过程进行探究。系统研究实验温度、混合流速和体积含水率对超高含水原油初始沉积过程的影响,分析不同温度下原油的运动形态和初始沉积方式。初始沉积过程可分为蔓延沉积过程和粘连沉积过程,根据沉积特点和压降曲线的变化趋势将初始沉积过程分为3个阶段：沉积诱导期、快速沉积期和沉积动态平衡期。通过对沉积物碳数分布的分析,得知超高含水原油初始沉积过程中,同时存在剪切剥离作用、胶凝作用和分子扩散作用。实验温度和体积含水率主要通过改变胶凝作用和分子扩散来影响初始沉积过程,混合流速通过改变剪切剥离强度来影响初始沉积过程。     

Gut microbiota and obesity:Impact of antibiotics and prebiotics and potential for musculoskeletal health

Obesity is a complex disease with multiple contributing factors.One of the most intensely studied factors during the past decade has been the gut microbiota,which is the community of all microbes in the intestinal tract.The gut microbiota,via energy extraction,inflammation,and other actions,is now recognized as an important player in the pathogenesis of obesity.Dysbiosis,or an imbalance in the microbial community,can initiate a cascade of metabolic disturbances in the host.Early life is a particularly important period for the development of the gut microbiota,and perturbations such as with antibiotic exposure can have long-lasting consequences for host health.In early life and throughout the life span,diet is one of the most important factors that shape the gut microbiota.Although diets high in fat and sugar have been shown to contribute to dysbiosis and disease,dietary fiber is recognized as an important fermentative fuel for the gut microbiota and results in the production of short-chain fatty acids that can act as signaling molecules in the host.One particular type of fiber,prebiotic fiber,contributes to changes in the gut microbiota,the most notable of which is an increase in the abundance of Bifidobacterium.This review highlights our current understanding of the role of gut microbiota in obesity development and the ways in which manipulating the microbiota through dietary means,specifically prebiotics,could contribute to improved health in the host,including musculo skeletal health.     

Impact of age on host responses to diet-induced obesity:Development of joint damage and metabolic set points

Background:Osteoarthritis is one of the leading causes of pain and disability worldwide,and a large percentage of patients with osteoarthritis are individuals who are also obese.In recent years,a series of animal models have demonstrated that obesity-inducing diets can result in synovial joint damage(both with and without the superimposition of trauma),which may be related to changes in percentage of body fat and a series of low-level systemic inflammatory mediators.Of note,there is a disparity between whether the dietary challenges commence at weaning,representing a weanling onset,or at skeletal maturity,representing an adult onset of obesity.We wished to evaluate the effect ofthe dietary exposure time and the age at which animals are exposed to a high-fat and high-sucrose(HFS) diet to determine whether these factors may result in disparate outcomes,as there is evidence suggesting that these factors result in differential metabolic disturbances.Based on dietary exposure time,we hypothesized that rats fed an HFS diet for 14 weeks from weaning(HFS Weanling) would demonstrate an increase in knee joint damage scores,whereas rats exposed to the HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult) and rats exposed to a standard chow diet(Chow)would not display an increase in knee joint damage scores.Methods:Male Sprague-Dawley rats were fed either an HFS diet for 14 weeks from weaning(HFS Weanling) or an HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult).At sacrifice,joints were scored using the modified Mankin Criteria,and serum was analyzed for a defined subset of inflammatory markers(Interleukin-6,leptin,monocyte chemoattractant protein-1,and tumor necrosis factorα).Results:When the HFS Weanling and HFS Adult groups were compared,both groups had a similar percent of body fat,although the HFS Weanling group had a significantly greater body mass than the HFS Adult group.The HFS Weanling and HFS Adult animals had a significant increase in body mass and percentage of body fat when compared to the Chow group.Although knee joint damage scores were low in all 3 groups,we found,contrary to our hypothesis,that the HFS Adult group had statistically significant greater knee joint damage scores than the Chow and HFS Weanling groups.Furthermore,we observed that the HFS Weanling group did not have significant differences in knee joint damage scores relative to the Chow group.Conclusion:These findings indicate that the HFS Weanling animals were better able to cope with the dietary challenge of an HFS diet than the HFS Adult group.Interestingly,when assessing various serum proinflammatory markers,no significant differences were detected between the HTS Adult and HFS Weanling groups.Although details regarding the mechanisms underlying an increase in knee joint damage scores in the HFS Adult group remain to be elucidated,these findings indicate that dietary exposure time maybe less important than the age at which an HFS diet is introduced.Moreover,increases in serum proinflammatory mediators do not appear to be directly linked to knee joint damage scores in the HFS Weanling group animals but may be partially responsible for the observed knee joint damage in the adults over the very short time of exposure to the HFS diet.     

Health-related fitness knowledge growth in middle school years: Individual- and school-level correlates

BackgroundHealth-related fitness knowledge (HRFK) has been an essential concept for many health and physical education programs. There has been limited understanding and longitudinal investigation on HRFK growth. This longitudinal study examined HRFK growth and its individual- and school-level correlates in middle school years under 1 curriculum condition: Five for Life.MethodsParticipants were 12,044 students from 47 middle schools. Data were collected at both individual/participant and school/institution levels. Individual-level variables included gender, grade, and HRFK test scores. School-level variables included percentage of students receiving free and reduced meals (FARM), student-to-faculty ratio for physical education, and school academic performance (SAP). We used hierarchical linear modeling to examine HRFK 3-year growth in relation to individual- and school-level correlates.ResultsThe average HRFK score at 6th grade for females was 42.81% ± 1.32%. The predicted HRFK growth was 17.06% ± 1.02% per year, holding other factors constant. A 1-standard deviation increase in FARM correlated with a 14.68%-point decrease in predicted test score (p = 0.02). A 1-standard deviation increase in SAP was associated with an 11.90%-point increase in HRFK score. Males had a significantly lower growth rate than females during the middle school years (0.78%/year, p = 0.02).ConclusionThe result showed that both individual- and school-level variables such as gender, FARM, and SAP influenced HRFK growth. Educators should heed gender differences in growth curves and recognize the correlates of school-level variables.