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321.
通过化学分析证明,美栌木与九里香属内的九里香组植物较为接近,两者均含月橘烯碱     及8-戊烯化香豆精,而棕茎组植物则与黄皮属植物亲缘关系较近。  据此肯定了Tanaka的观     点,认为棕茎组比九里香组原始。黄皮族内的亲缘关系亦可作如下推断:  小芸木属→山小桔属→黄皮属→九里香属棕茎组→九里香属九里香组→美栌木属。  相似文献   
322.
Methylphenidate (MPH) often ameliorates attention-deficit/hyperactivity disorder (ADHD) behavioral dysfunction according to indirect informant reports and rating scales. The standard of care behavioral MPH titration approach seldom includes direct neuropsychological or academic assessment data to determine treatment efficacy. Documenting "cool" executive-working memory (EWM) and "hot" self-regulation (SR) neuropsychological impairments could aid in differential diagnosis of ADHD subtypes and determining cognitive and academic MPH response. In this study, children aged 6 to 16 with ADHD inattentive type (IT; n = 19) and combined type (n = 33)/hyperactive-impulsive type (n = 4) (CT) participated in double-blind placebo-controlled MPH trials with baseline and randomized placebo, low MPH dose, and high MPH dose conditions. EWM/ SR measures and behavior ratings/classroom observations were rank ordered separately across conditions, with nonparametric randomization tests conducted to determine individual MPH response. Participants were subsequently grouped according to their level of cool EWM and hot SR circuit dysfunction. Robust cognitive and behavioral MPH response was achieved for children with significant baseline EWM/SR impairment, yet response was poor for those with adequate EWM/ SR baseline performance. Even for strong MPH responders, the best dose for neuropsychological functioning was typically lower than the best dose for behavior. Findings offer one possible explanation for why long-term academic MPH treatment gains in ADHD have not been realized. Implications for academic achievement and medication titration practices for children with behaviorally diagnosed ADHD will be discussed.  相似文献   
323.

Objectives

To present a detailed confession from a perpetrator of Shaken Baby syndrome.

Methods

Case study.

Results

We present a confession of Shaken Baby syndrome describing how the perpetrator severely injured a 3 year old with repeated bursts of acceleration-deceleration (shaking). The child sustained retinal and intracranial hemorrhage. Details of the confession and circumstances by which it was obtained lead us to believe its accuracy.

Conclusions

Accurate perpetrator confessions offer useful windows into realities and pathophysiology of abusive head trauma.  相似文献   
324.
We report an investigation of the validity of teachers' ratings of children's progress in ‘phonics’ as a screener for dyslexia. Seventy‐three 6‐year‐olds from a whole school population were identified as ‘at risk’ of dyslexia according to teacher judgements of slow progression through phonic phases. Six months later, children's attainments in literacy and phonological skills were compared with those of their typically developing peers matched on age and gender. Teacher assessments of risk were related to individual differences in performance on a standardised test of reading ability. Teacher assessments overestimated ‘risk of dyslexia’, defined as below‐average reading performance. However, teacher judgements, supplemented by tests of phoneme awareness and rapid naming, allowed a sensitive and specific identification of children who subsequently experienced reading difficulties. These findings show teachers can identify risk of dyslexia; the accuracy of this process can be improved by administering two tests of phonological skills.  相似文献   
325.
This study investigated students’ activating positive affective experiences in mathematics lessons, their antecedents, their cognitive and motivational consequences, as well as their effect on achievement. The participants were 682 Grade 8 and 9 students from 37 classes from Germany and Switzerland who participated in a video study of lessons on the Pythagorean theorem. Control and value beliefs as well as autonomy support proved to be relevant predictors of positive affective experiences. Moreover, positive affective experiences were associated with more cognitive activity during the lessons, which for its part predicted achievement in the posttest. In a follow-up test, there was also an indirect effect of positive affective experiences on achievement, mediated by cognitive activity and expectancy of success.  相似文献   
326.
In early 2020, the Covid-19 crisis forced medical institutions worldwide to convert quickly to online platforms for content delivery. Although many components of medical education were adaptable to that format, anatomical dissection laboratory lost substantial content in that conversion, including features of active student participation, three-dimensional spatial relationships of structures, and the perception of texture, variation, and scale. The present study aimed to develop and assess online anatomy laboratory sessions that sought to preserve benefits of the dissection experience for first-year medical students. The online teaching package was based on a novel form of active videography that emulates eye movement patterns that occur during processes of visual identification, scene analysis, and learning. Using this video-image library of dissected materials, content was presented through asynchronous narrated laboratory demonstrations and synchronous/active video conference sessions and included a novel, video-based assessment tool. Data were obtained using summative assessments and a final course evaluation. Test scores for the online practical examination were significantly improved over those for previous in-person dissection-based examinations, as evidenced by several measures of performance (Mean: 2015–2019: 82.5%; 2020: 94.9%; P = 0.003). Concurrently, didactic test scores were slightly, but not significantly, improved (Mean: 2015–2019: 88.0%; 2020: 89.9%). Student evaluations of online sessions and overall course were highly positive. Results indicated that this innovative online teaching package can provide an effective alternative when in-person dissection laboratory is unavailable. Although this approach consumed considerable faculty time for video editing, further development will include video conference breakout rooms to emulate dissection small-group teamwork.  相似文献   
327.
成本已成为当今PCB生产中的首要问题,制造商正在不断寻求方法减少生产所需的工作人员.在过去十年中,自动化生产设备的不断发展对削减人工成本起了很大作用,然而劳动力成本在生产总成本中仍占相当比例.  相似文献   
328.
Most science educators advocate the importance of hands-on activities for learning in science. However, little research has been directed at understanding the students' orientations toward phenomena and the ways in which these orientations influence the learning experience. Through microanalyses of videotape data of a summer science camp for elementary school children, we characterize students' orientations when exploring natural phenomena as modes of engagement. The six frequently observed orientations toward phenomena include exploration mode (to find out about the object and study its basic properties), engineering mode (a focus on making something happen), pet care mode (a personal connection focused on nurturing), procedural mode (an imitation and step-following orientation), performance mode (soliciting attention using the phenomenon as a prop), and fantasy mode (an imaginative play activity which builds on some aspect of the phenomena). These modes of engagement helped provide personal contexts in which the students' interactions with phenomena took shape, and these modes were arguably as important an influence on personal contexts as other conceptual or contextual influences. © 1996 John Wiley & Sons, Inc.  相似文献   
329.
Brain dissection is typically an important part of teaching neuroscience in health professional programs. This results in the need to effectively remove brains, which is often performed in a gross anatomy laboratory in the same curriculum. The aim of this study was to determine the most effective method of brain removal based on the time required for removal, difficulty of removal, and preservation of key brain structures for educational purposes. Six different dissectors performed each of the three calvaria removal approaches and three different spinal cord transection methods rating them for difficulty and tracking the time required. The combination of calvaria and brainstem approaches and the order of completion was randomized to control for fatigue and previous individual experience. After all brains were removed, each was evaluated by neuroscience faculty for utility in education contexts. The study found little difference between the individual approaches for both calvaria removal and spinal cord transection in regards to quality of outcome. The use of a circumferential cut only proved to be the most time-effective method for calvaria removal while a posterior cut between C1 and C2 was the most time-effective and least difficult method for brainstem release. There was no one technique that proved to be most beneficial across all three measures. However, different approaches resulted in a different combination of benefits across the time, difficulty, and outcome ratings that should be considered in light of the individual needs of any program or researcher.  相似文献   
330.
Segmental sequencing of kinetic energy in a computer-simulated golf swing   总被引:1,自引:1,他引:0  
The concept of the transfer of kinetic energy (KE) sequentially through the human body from proximal to distal segments is an influential concept in biomechanics literature. The present study develops this area of research through investigation of segmental sequencing of the transfer of KE by means of computer simulation. Using a musculoskeletal computer model previously developed by the authors, driven using three-dimensional kinematic data from a single elite male golfer, combined inverse and forward dynamics analyses enabled derivation of KE. Rigid body segments of torso, hips, arms and clubhead were examined in line with previous literature. Using this method a driver swing was compared to a 7 iron swing. Findings showed a high level of correlation between driver and iron peak KE and timing of peak KE relative to impact. This seems to indicate equivalent trunk and arms linear velocity, thus force applied, for an iron shot and a driver shot. There were highly significant differences between KE output for body segments for both clubs. In addition, peak KE magnitudes increased sequentially from proximal to distal segments during swing simulations for both the driver and 7 iron. This supports the principle of the summation of speed. However, timing of peak KE was not sequential from proximal to distal segments, nor did segments peak simultaneously. Rather, arms peaked first, followed by hips, torso and club. This seems to indicate a subjective optimal coordination of sequencing.
Ian C. KennyEmail:
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