Exercise interventions for older adults: A systematic review of meta-analyses

Background:The evidence concerning which physical exercise characteristics are most effective for older adults is fragmented.We aimed to characterize the extent of this diversity and inconsistency and identify future directions for research by undertaking a systematic review of metaanalyses of exercise interventions in older adults.Methods:We searched the Cochrane Database of Systematic Reviews,PsycInfo,MEDLINE,Embase,CINAHL,AMED,SPORTDiscus,and Web of Science for articles that met the following criteria:(1)meta-analyses that synthesized measures of improvement(e.g.,effect sizes)on any outcome identified in studies of exercise interventions;(2)participants in the studies meta-analyzed were adults aged 65+or had a mean age of 70+;(3)meta-analyses that included studies of any type of exercise,including its duration,frequency,intensity,and mode of delivery;(4)interventions that included multiple components(e.g.,exercise and cognitive stimulation),with effect sizes that were computed separately for the exercise component;and(5)meta-analyses that were published in any year or language.The characteristics of the reviews,of the interventions,and of the parameters improved through exercise were reported through narrative synthesis.Identification of the interventions linked to the largest improvements was carried out by identifying the highest values for improvement recorded across the reviews.The study included 56 meta-analyses that were heterogeneous in relation to population,sample size,settings,outcomes,and intervention characteristics.Results:The largest effect sizes for improvement were found for resistance training,meditative movement interventions,and exercise-based active videogames.Conclusion:The review identified important gaps in research,including a lack of studies investigating the benefits of group interventions,the characteristics of professionals delivering the interventions associated with better outcomes,and the impact of motivational strategies and of significant others(e.g.,carers)on intervention delivery and outcomes.     

Evaluative Conditioning and the Development of Attitudes in Early Childhood

Many attitudes are acquired in early childhood. However, due to a lack of experimental research, little is known about the processes of how they are acquired. Two experiments were therefore conducted with 153 German kindergarten children aged 3–6 years that provide first evidence for childhood attitude formation in terms of evaluative conditioning. Specifically, it was found that children preferred novel stimuli previously paired with liked stimuli over novel stimuli previously paired with disliked stimuli. This effect occurred independently of age, generalized toward similar novel stimuli, and did not depend on children's recollection of how stimuli were paired. The findings are discussed in terms of the processes underlying childhood attitude formation, and implications for related research areas are highlighted.     

Circulating but not immobilized N-deglycosylated von Willebrand factor increases platelet adhesion under flow conditions

The role of von Willebrand factor (VWF) as a shear stress activated platelet adhesive has been related to a coiled-elongated shape conformation. The forces dominating this transition have been suggested to be controlled by the proteins polymeric architecture. However, the fact that 20% of VWF molecular weight originates from glycan moieties has so far been neglected in these calculations. In this study, we present a systematic experimental investigation on the role of N-glycosylation for VWF mediated platelet adhesion under flow. A microfluidic flow chamber with a stenotic compartment that allows one to mimic various physiological flow conditions was designed for the efficient analysis of the adhesion spectrum. Surprisingly, we found an increase in platelet adhesion with elevated shear rate, both qualitatively and quantitatively fully conserved when N-deglycosylated VWF (N-deg-VWF) instead of VWF was immobilized in the microfluidic channel. This has been demonstrated consistently over four orders of magnitude in shear rate. In contrast, when N-deg-VWF was added to the supernatant, an increase in adhesion rate by a factor of two was detected compared to the addition of wild-type VWF. It appears that once immobilized, the role of glycans is at least modified if not—as found here for the case of adhesion—negated. These findings strengthen the physical impact of the circulating polymer on shear dependent platelet adhesion events. At present, there is no theoretical explanation for an increase in platelet adhesion to VWF in the absence of its N-glycans. However, our data indicate that the effective solubility of the protein and hence its shape or conformation may be altered by the degree of glycosylation and is therefore a good candidate for modifying the forces required to uncoil this biopolymer.     

Hematocrit and flow rate regulate the adhesion of platelets to von Willebrand factor

Primary hemostasis and blood clotting is known to be influenced by the red blood cell volume fraction (hematocrit) in blood. Depressed or elevated levels of red blood cells can lead to vascular perfusion problems ranging from bleeding to thrombus formation. The early stage of hemostasis and thus blood clotting in all vessel sections from the arterial to the venous system involves the adhesion of platelets to von Willebrand factor. Here we present experimental and theoretical results showing that the adhesion probability of platelets to von Willebrand factor is strongly and nonlinearly dependent on hematocrit and flow rate. Interestingly, the actual binding forces are not markedly different, which suggest that the origin of such behavior is in the distribution of platelets. Using hydrodynamic simulations of a simple model, we explicitly show that the higher the hematocrit and the flow rate, the larger the amount of platelets residing close to the wall. Our simulation results, which are in excellent agreement with the experimental observations, explain why such phenomena occur. We believe that the nonhomogeneous red blood cell distribution as well as the shear dependent hydrodynamic interaction is key for the accumulation of platelets on the vessel wall. The work we present here is an important step forward from our earlier work on single molecules and extends into the collective cellular behavior of whole blood. It sheds new light on the correlation between hematocrit and the initial steps in hemostasis and thrombosis, and outlines advances for the treatment of vascular diseases associated with high levels of red blood cells. These results are not only highly relevant for the field of hemostasis and the physics of blood clotting but are also of powerful impact in applied science most obviously in drug delivery and colloidal science.     

Predicting Children's Friendship Status from Their Dyadic Interaction in Structured Situations of Potential Conflict

Dyads of 8-year-old friends identified by sociometric friendship nominations were followed through the end of the school year to determine if they remained friends. These dyads as well as a control group of nonfriends were observed while participating in two structured tasks designed to simulate real life social situations of potential conflict. When negotiating the sharing of an object, friends made more proposals than nonfriends, spent more time negotiating, and compromised more in making their counterproposals. Compared with dyads in which the friendship did not continue through the end of the school year, dyads of continuing friends exhibited greater sensitivity in their negotiations. During a fast-paced, competitive game, friends engaged in more competitive behavior and followed the rules more closely than did nonfriends. However, behavior in this game was unrelated to the continuation of friendship.     

Testing one premise of scientific inquiry in science classrooms: Examining students' scientific explanations and student learning

In this study, we analyzed the quality of students' written scientific explanations found in notebooks and explored the link between the quality of the explanations and students' learning. We propose an approach to systematically analyzing and scoring the quality of students' explanations based on three components: claim, evidence to support it, and a reasoning that justifies the link between the claim and the evidence. We collected students' science notebooks from eight science inquiry‐based middle‐school classrooms in five states. All classrooms implemented the same scientific‐inquiry based curriculum. The study focuses on one of the implemented investigations and the students' explanations that resulted from it. Nine students' notebooks were selected within each classroom. Therefore, a total of 72 students' notebooks were analyzed and scored using the proposed approach. Quality of students' explanations was linked with students' performance in different types of assessments administered as the end‐of‐unit test: multiple‐choice test, predict‐observe‐explain, performance assessment, and a short open‐ended question. Results indicated that: (a) Students' written explanations can be reliably scored with the proposed approach. (b) Constructing explanations were not widely implemented in the classrooms studied despite its significance in the context of inquiry‐based science instruction. (c) Overall, a low percentage of students (18%) provided explanations with the three expected components. The majority of the sample (40%) provided only claims without any supporting data or reasoning. And (d) the magnitude of the correlations between students' quality of explanations and their performance, were all positive but varied in magnitude according to the type of assessment. We concluded that engaging students in the construction of high quality explanations may be related to higher levels of student performance. The opportunities to construct explanations in science‐inquiry based classrooms, however, seem to be limited. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 583–608, 2010     

Hospital library foreign language labs: the experiences of two hospital libraries

Increasingly, hospital-based physicians, residents, and medical students are welcoming into their care foreign-born patients, who do not speak English. Most hospitals today have an Interpretive Services Department, but many of the physicians, residents, and medical students want to become more proficient in the most frequently spoken foreign languages in their respective locales. To help recruit and retain a diverse workforce, some hospitals sponsor English programs for staff. The Treadwell Library at Massachusetts General Hospital in Boston, Massachusetts, and the Grady Branch Library at Grady Memorial Hospital in Atlanta, Georgia, have developed a special collection and hospital library-based language laboratories in order to meet this need.     

German Book Publishers’ Barriers to Disruptive Innovations: The Case of E-Book Adoption

To succeed in a period of change, German book publishers need to adopt innovations, e.g., implement e-books into their product portfolio. Yet, in the book industry, the adoption of new technologies is not commonplace: Despite being the second biggest book market worldwide, only 1.2 % of all published books in Germany are available as e-books. This problem leads us to investigate the factors that determine whether publishing companies decide in favor or against entering the e-book market. Based on a standardized survey of more than 240 German publishing houses, barriers to innovation adoption are examined from a micro, meso and macro perspective. Our main findings show that individual characteristics of management and the company’s corporate culture strongly predict adoption. Also, organizational communication seems to be critical. Taking this into account, the key resource to enable innovation seems to be information underlining the necessity of communities of practice.