Correlation network analysis shows divergent effects of a long-term,high-fat diet and exercise on early stage osteoarthritis phenotypes in mice

Background:Obesity increases knee osteoarthritis(OA) risk through metabolic,inflammatory,and biomechanical factors,but how these systemic and local mediators interact to drive OA pathology is not well understood.We tested the effect of voluntary running exercise after chronic diet-induced obesity on knee OA-related cartilage and bone pathology in mice.We then used a correlation-based network analysis to identify systemic and local factors associated with early-stage knee OA phenotypes among the different diet and exercise groups.Methods:Male C57 BL/6 J mice were fed a defined control(10% kcal fat) or high fat(HF)(60% kcal fat) diet from 6 to 37 weeks of age.At 25 weeks,one-half of the mice from each diet group were housed in cages with running wheels for the remainder of the study.Histology,micro computed tomography,and magnetic resonance imaging were used to evaluate changes in joint tissue structure and OA pathology.These local variables were then compared to systemic metabolic(body mass,body fat,and glucose tolerance),inflammatory(serum adipokines and inflammatory mediators),and functional(mechanical tactile sensitivity and grip strength) outcomes using a correlation-based network analysis.Diet and exercise effects were evaluated by two-way analysis of variance.Results:An HF diet increased the infrapatellar fat pad size and posterior joint osteophytes,and wheel running primarily altered the subchondral cortical and trabecular bone.Neither HF diet nor exercise altered average knee cartilage OA scores compared to control groups.However,the coefficient of variation was≥25% for many outcomes,and some mice in both diet groups developed moderate OA(>33% maximum score).This supported using correlation-based network analyses to identify systemic and local factors associated with early-stage knee OA phenotypes.In wheel-running cohorts,an HF diet reduced the network size compared to the control diet group despite similar running distances,suggesting that diet-induced obesity dampens the effects of exercise on systemic and local OA-related factors.Each of the 4 diet and activity groups showed mostly unique networks of local and systemic factors correlated with early-stage knee OA.Conclusion:Despite minimal group-level effects of chronic diet-induced obesity and voluntary wheel running on knee OA pathology under the current test durations,diet and exercise substantially altered the relationships among systemic and local variables associated with early-stage knee OA.These results suggest that distinct pre-OA phenotypes may exist prior to the development of disease.     

Cognitive controls: A test of their modifiability and structural arrangement

This study focused on two concepts basic to the cognitive control approach—the modifiability of cognitive control structures, and their proposed hierarchical, structural arrangement. Eighty children designated as deficient in cognitive functioning beginning at either two levels of deficiency (field articulation or leveling-sharpening) were provided one of four types of intervention. The hypotheses tested were: (a) that intervention provided directly at the level of the first deficiency would be significantly more effective than either intervention provided a level below or a level above the area of first deficiency, or of a control condition; and (b) that cognitive control structures form a hierarchical, structural arrangement. Training effects were indexed by cognitive performance measures at both pretest and pos est. The results were consistent with the initial hypothesis that cognitive control deficiencies can be remediated beer by structure-based types of intervention than by the types of skill training normally provided in the classroom. In contrast, the second hypothesis—that cognitive controls form a hierarchical, structural arrangement—was only partially confirmed. Additional systematic research into the modifiability and structural arrangement of cognitive controls was strongly recommended.     

Improving Mathematics Instruction and Learning in the Junior High School: An Israeli Example

Abstract

A 4‐year project is described which was designed to improve mathematics instruction and achievements in two Israeli junior high schools. Project activities focused on the individual teachers, the mathematics staff, and the organization of instruction at the school level, under the assumption that more efficient teaching would lead to greater pupil learning.

Evaluation data gathered from classroom observation, questionnaires and tests indicated a general positive impact: many teachers improved their teaching strategies, more curricular material was being covered in class, a school‐wide program for mathematics instruction was established, teamwork among teachers was formalized, and pupil achievements improved.     

The impact of core and infrastructure business activities on information systems planning and effectiveness

Core and infrastructure business activities are vital to the organization, and are growing more and more dependent on information systems. Theory suggests that more core and infrastructure business activities would inspire more strategic information systems planning which in turn would result in greater planning effectiveness. One hundred thirty chief information officers in manufacturing companies completed a questionnaire about the extent that their organization performed core and infrastructure business activities, and carried out technical, personnel, and procedures planning. The findings showed that infrastructure activities lead to all three types of planning whereas core activities lead only to procedures planning. Moreover, they showed that technical planning leads to planning effectiveness whereas personnel and procedures planning do not. The findings suggest that future researchers might try to uncover the reasons that core activities do not lead to more information systems planning. For practitioners, the findings suggest that managers reconsider how their organizations respond to core and infrastructure needs, and whether they should adjust their information systems planning.     

CURRICULUM LEADERSHIP,INNOVATION, AND CHANGE

Anticipated changes in the population that will be served in the 1990s have implications for the curriculum that will be needed in postsecondary educational programs. These changes will require consideration of the leadership needed to guide institutions seeking innovation and change in the curriculum for the future. The major themes of this article focus on (a) leadership skills essential for curriculum planners, (b) needed innovation in curriculum planning, and (c) planning for curriculum change.     

High-throughput size-based rare cell enrichment using microscale vortices

Cell isolation in designated regions or from heterogeneous samples is often required for many microfluidic cell-based assays. However, current techniques have either limited throughput or are incapable of viable off-chip collection. We present an innovative approach, allowing high-throughput and label-free cell isolation and enrichment from heterogeneous solution using cell size as a biomarker. The approach utilizes the irreversible migration of particles into microscale vortices, developed in parallel expansion-contraction trapping reservoirs, as the cell isolation mechanism. We empirically determined the critical particle∕cell diameter D(crt) and the operational flow rate above which trapping of cells∕particles in microvortices is initiated. Using this approach we successfully separated larger cancer cells spiked in blood from the smaller blood cells with processing rates as high as 7.5×10(6) cells∕s. Viable long-term culture was established using cells collected off-chip, suggesting that the proposed technique would be useful for clinical and research applications in which in vitro culture is often desired. The presented technology improves on current technology by enriching cells based on size without clogging mechanical filters, employing only a simple single-layered microfluidic device and processing cell solutions at the ml∕min scale.     

Accuracy of an infrared LED device to measure heart rate and energy expenditure during rest and exercise

The purpose of this study was to examine the accuracy of the ePulse Personal Fitness Assistant, a forearm-worn device that provides measures of heart rate and estimates energy expenditure. Forty-six participants engaged in 4-minute periods of standing, 2.0 mph walking, 3.5 mph walking, 4.5 mph jogging, and 6.0 mph running. Heart rate and energy expenditure were simultaneously recorded at 60-second intervals using the ePulse, an electrocardiogram (EKG), and indirect calorimetry. The heart rates obtained from the ePulse were highly correlated (intraclass correlation coefficients [ICCs] ≥0.85) with those from the EKG during all conditions. The typical errors progressively increased with increasing exercise intensity but were <5 bpm only during rest and 2.0 mph. Energy expenditure from the ePulse was poorly correlated with indirect calorimetry (ICCs: 0.01-0.36) and the typical errors for energy expenditure ranged from 0.69-2.97 kcal · min(-1), progressively increasing with exercise intensity. These data suggest that the ePulse Personal Fitness Assistant is a valid device for monitoring heart rate at rest and low-intensity exercise, but becomes less accurate as exercise intensity increases. However, it does not appear to be a valid device to estimate energy expenditure during exercise.     

High bar swing performance in novice adults: effects of practice and talent

An individual's a priori talent can affect movement performance during learning. Also, task requirements and motor-perceptual factors are critical to the learning process. This study describes changes in high bar swing performance after a 2-month practice period. Twenty-five novice participants were divided by a priori talent level (spontaneous-talented [ST] and nonspontaneous-talented [NST]) and compared to experienced gymnasts. Additionally, we assessed their perception of their performance level before and after practice. We defined three events independently for hip (H) and shoulder (S) angle joints and for the lag between consecutive events (phases [P]): the smallest angle during downswing (P1H, P1S), the largest angle after P1 (P2H, P2S), and the smaller angle during upswing (P3H, P3S). Movement performance variables were the maximum elevation on the downswing (Pi) and the upswing (Pf), and the total path between both (swing amplitude). Data were collected during pre- and postpractice sessions by two video cameras. At the end of both sessions, participants drew a sketch to represent their perception of their performance level relative to the Pi, Pf and the hip events. Results showed a similar practice effect in the swing amplitude in both novice groups. However the ST group 's performance and perception variables on the downswing improved more than the NST group due to practice. This study suggests that (a) downswing improvements were easier than in the upswing, possibly due to familiarity of the visual reference in combination with proprioceptive feedback; and (b) being ST may involve a better orfaster gain in perception of self-action compared to NST.