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121.
Student difficulties in science learning are frequently attributed to misconceptions about scientific concepts. We argue that domain‐general perceptual processes may also influence students' ability to learn and demonstrate mastery of difficult science concepts. Using the concept of center of gravity (CoG), we show how student difficulty in applying CoG to an object such as a baseball bat can be accounted for, at least in part, by general principles of perception (i.e., not exclusively physics‐based) that make perceiving the CoG of some objects more difficult than others. In particular, it is perceptually difficult to locate the CoG of objects with asymmetric‐extended properties. The basic perceptual features of objects must be taken into account when assessing students' classroom performance and developing effective science, technology, engineering, and mathematics (STEM) teaching methods.  相似文献   
122.
Methods for assaying lysosomal diseases in dried blood samples are very useful today due to its several advantages related to the stability of samples, its transportation, handled and analysis, and its potential use for newborn screening compared to traditional methods in leucocytes samples. For this reason, it is important to validate these assays before being used in routine laboratory. Because of different in biological markers based on ethnicity, we aimed this study to validation a DBS-based fluorometric assay for measurement of α-l-Iduronidase activity for diagnosis of MPS I patients in Iran. DBS samples were collected from 15 MPS I patients and 60 healthy age matched subjects. Diagnostic value, biological variance and α-l-Iduronidase activity were determined. DBS α-l-Iduronidase activity was significantly higher in male subjects than in female group. Using a cut-off level of 1.08 µmol/spot 20 h, sensitivity and specificity were 100 and 98 %. The linearity of test was proved and we showed that within-run and between run precision were 5.6 and 14.66 %. Measurement of α-l-Iduronidase activity in DBS samples is an accurate test for diagnosis of MPS I and because of its rapid shipping and simplicity to keeping, DBS-based enzyme activity could be considered as a useful diagnostic tool in this disease.  相似文献   
123.

Introduction

Vaspin (visceral adipose tissue-derived serpin) was first described as an insulin-sensitizing adipose tissue hormone. Recently its anti-inflammatory function has been demonstrated. Since no appropriate data is available yet, we sought to investigate the plasma concentrations of vaspin in sepsis.

Materials and methods

57 patients in intensive care, fulfilling the ACCP/SCCM criteria for sepsis, were prospectively included in our exploratory study. The control group consisted of 48 critically ill patients, receiving intensive care after trauma or major surgery. Patients were matched by age, sex, weight and existence of diabetes before statistical analysis. Blood samples were collected on the day of diagnosis. Vaspin plasma concentrations were measured using a commercially available enzyme-linked immunosorbent assay.

Results

Vaspin concentrations were significantly higher in septic patients compared to the control group (0.3 (0.1-0.4) ng/mL vs. 0.1 (0.0-0.3) ng/mL, respectively; P < 0.001). Vaspin concentration showed weak positive correlation with concentration of C-reactive protein (CRP) (r = 0.31, P = 0.002) as well as with SAPS II (r = 0.34, P = 0.002) and maximum of SOFA (r = 0.39, P < 0.001) scoring systems, as tested for the overall study population.

Conclusion

In the sepsis group, vaspin plasma concentration was about three-fold as high as in the median surgical control group. We demonstrated a weak positive correlation between vaspin and CRP concentration, as well as with two scoring systems commonly used in intensive care settings. Although there seems to be some connection between vaspin and inflammation, its role in human sepsis needs to be evaluated further.Key words: adipocytokine, inflammation, vaspin, CRP, intensive care  相似文献   
124.
The aim was to test the influence of sex and specialty (3000, 5000 and 10000 m) on the validity of middle-distance running performance predictions obtained from the Mercier et al.’s nomogram. Consequently, we examined all official French track running rankings for the 3000-, 5000- and 10000-m events (men and women) from 2006 to 2012. A scoring table was used to determine the runners’ specialties. Only runners who performed in the three distance events within the same year were included (75 women and 400 men). The Mercier et al.’s nomogram was used to predict one running performance from the other two. The results showed no significant difference between actual and predicted running performances (= 0.77). Female runners had significantly lower performances than male runners (< 0.001). Specialty did not influence performances (= 0.11). Very high correlations were found between actual and predicted performances (0.91 < < 0.99), with the exception of women (= 0.85) in 5000 m. Moreover, low limits of agreement were obtained for male and female runners, whatever the specialty. These results support the validity of the nomogram to predict running performance in the 3000-, 5000- and 10000-m events for male and female runners, whatever the specialty. The predicted running performances may be used in training programmes (e.g., to prescribe tempo runs) and competitions (e.g., to establish split times).  相似文献   
125.
Using a non-linear approach, intentional dynamics of thoughts were examined during constant cycling performed until volitional exhaustion. Participants (= 12) completed two sessions at 80% Wmax. Their (1) intrinsic thought dynamics (i.e., no-imposed thoughts condition) and (2) intentional thought dynamics (i.e., imposed task-unrelated thoughts condition; TUT) were recorded and then classified into four categories: internal and external TUT (TUT-I, TUT-E) and external and internal task-related thoughts (TRT-E, TRT-I). The probability estimates for maintaining each thought category stable, the rate of switching from one category to another, and the entropy dynamics along the testing procedure were assessed and compared through time phase. Friedman ANOVA tests revealed a significant effect of effort increase on thought contents only in the imposed TUT test. While TUT-I probabilities decreased significantly (P < .001) as effort increased, TRT-I probabilities increased (< .05). Moreover, the entropy to the entire thought dynamics increased at the outset of task performance and decreased upon approaching volitional exhaustion (< .001). As time spent in constant effort increased, and volitional exhaustion approached, task relatedness (TUT, TRT), direction (internal, external), and entropy of thought contents changed unintentionally providing further evidence for a nonlinear dynamics of attention focus.  相似文献   
126.
The academic library, given its often privileged position on campus, is the information source that can include directional as well as general campus facts among the myriad of print and e-resources for reference. Also, an academic library's audiences can be quite varied and include prospective students or parents seeking more general knowledge of the building and the campus. Many times this need for information drives patrons to the library service desks. Sometimes, especially during the high-demand seasons of new student orientation and beginning of the fall semesters, the desk is so busy that many patrons will leave because they don't have the time to wait. To address this immediate need for information, Texas Tech University Libraries developed an interactive kiosk to provide general information for frequently asked questions in a more efficient, creative, and interactive way. The kiosk provides a fun method of satisfying a patron's information needs without the requirement of a staff member or the need to wait in line for help. The kiosk is available as long as the Library is open and provides a variety of useful answers to general questions, as well as facts about the Library.  相似文献   
127.
The Ontario Council of University Libraries (OCUL) is a consortium of the twenty-one university libraries in Ontario, Canada. Since 1967, OCUL member institutions have worked together to share costs and workload through collective purchasing and licensing of information resources and more recently through the establishment of a shared digital infrastructure known as Scholars Portal. Under the auspices of OCUL, Ontario's university map librarians formed the OCUL Map Group in 1973 to seek opportunities to communicate and collaborate to improve the collections and services they offer their users. The opportunities provided by collaboration have ensured a greater capacity to manage evolving collections of geospatial data. The group has served as a community of practice, which has provided educational opportunities and facilitated collaborative problem solving through a listserv, conference calls, and face-to-face meetings. This collegial environment has also led to the completion of a number of projects, which have resulted in the creation of new technical infrastructures and strategies for sharing the workload of data management tasks. This paper discusses the role of collaboration in OCUL projects and offers some suggestions for others considering embarking on collaborations of their own.  相似文献   
128.
ABSTRACT

Changes in information communication technology across the Asian region have altered our field substantively and methodologically. The rapid growth of digitized communications allows us to find new purchase in examining questions fundamental to our understanding of communication theories, norms, and practices across Asia. While methods such as text mining and user analytics are increasingly popular among computational scholars, here, we focus on online field experiments, an approach to studying communication that has the potential to overcome many existing obstacles to social scientific inquiry but one that has been used relatively rarely in Asia. In this paper, we discuss what online field experiments are and how they differ from traditional experiments as well as online lab and survey experiments. We show how researchers can go about designing and implementing online field experiments, focusing on issues where online field experiments differ from their traditional counterparts – legal and ethical considerations, construct validity, randomization and spillover, and statistical analyses. Finally we discuss how online field experiments can advance our understanding of communication in Asia by helping researchers to gain insight and make causal inferences on attitudes, behaviors, and interactions that were previously unobservable ?.  相似文献   
129.
130.
在秘鲁安第斯山脉的崇山峻岭中有一座神秘的古城。西班牙人在长达300年的殖民统治期间对它一无所知,秘鲁独立后的100年间也无人涉足。400多年的时光,只有翱翔的山鹰得以一睹古城的雄姿,它就是马丘比丘印加遗址。作为马丘比丘的"姐妹城",肖克奎拉奥可谓是寂寂无名,但却有着马丘比丘无可比拟的孤独与安静。本文作者向我们介绍了在肖克奎拉奥的徒步探险经历,巨石垒筑的残垣断壁正向我们讲述着当年的故事.我们还会感受到怀古的幽思、逝去的光华,以及领略这座古城记载着的印加人无与伦比的智慧。  相似文献   
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