1,511 research outputs found

    High-Stakes Testing and Student Achievement: Problems for the No Child Left Behind Act

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    Under the federal No Child Left Behind Act of 2001 (NCLB), standardized test scores are the indicator used to hold schools and school districts accountable for student achievement. Each state is responsible for constructing an accountability system, attaching consequences -- or stakes -- for student performance. The theory of action implied by this accountability program is that the pressure of high-stakes testing will increase student achievement. But this study finds that pressure created by high-stakes testing has had almost no important influence on student academic performance

    U.S. v. Microsoft: Did Consumers Win?

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    U.S. v. Microsoft and the related state suit filed in 1998 appear finally to have concluded. In a unanimous en banc decision issued in late June 2004, the D.C. Circuit Court of Appeals rejected challenges to the remedies approved by the District Court in November 2002. The wave of follow-on private antitrust suits filed against Microsoft also appears to be subsiding. In this paper we review the remedies imposed in the United States, in terms of both their relationship to the violations found and their impact on consumer welfare. We conclude that the remedies addressed the violations ultimately found by the Court of Appeals (which were a subset of those found by the original district court and an even smaller subset of the violations alleged, both in court and in public discourse) and went beyond them in important ways. Thus, for those who believe that the courts were right in finding that some of Microsoft's actions harmed competition, the constraints placed on its behavior and the active, ongoing oversight by the Court and the plaintiffs provide useful protection against a recurrence of such harm. For those who believe that Microsoft should not have been found liable because of insufficient evidence of harm to consumers, the remedies may be unnecessary, but they avoided the serious potential damage to consumer welfare that was likely to accompany the main alternative proposals. The remedies actually imposed appear to have struck a reasonable balance between protecting consumers against the types of actions found illegal and harming consumers by unnecessarily restricting Microsoft's ability to compete.

    Changes In Femoral Neck Bone Mineral Density: A Comparison Of NHANES 2005-2006, 2007-2008, And 2009-2010

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    Bone mass is an important component of quality of life and can be influenced by lifestyle factors, such as physical activity and diet. However the US surgeon general found a growing portion of Americans are not engaging in adequate amounts of physical activity and/or consuming less calcium and vitamin D. The purpose of this study was to compare bone mineral density (BMD) of American adults of different ethnicities and time periods to detect any differences. It was hypothesized that BMD would be lower in participants from more recent years, and African Americans would have the highest BMD. Measurements were taken at the femoral neck of volunteers between 18 and 35 years of age (n = 3578) from 2005-2006 (n = 1160), 2007-2008, (n = 1135), and 2009-2010 (n = 1283) by the National Center for Health Statistics. The data was analyzed using a three-way independent ANOVA with an alpha level of .05. Femoral neck BMD was used as the dependent variable; and year, age, and race were independent variables. The study found Hispanic women to have a significantly higher BMD from 2005-2006 (p \u3c.05) when compared to participants from later years. In addition, the study found significant differences based on age and ethnicity (p \u3c .001). African-American men (p \u3c .001) and women (p \u3c.001) had a higher BMD than any other ethnicity. Moreover, Hispanic men had a higher BMD (p \u3c.001) than Caucasian men. In men, BMD significantly decreased in each age group (p \u3c.001); whereas in women a significant decrease was detected in every other age group (p \u3c .05). However, in contradiction to literature, the results found peak BMD to occur between 18 and 19 years of age as opposed to mid-to-late twenties

    A Unified Approach to Attractor Reconstruction

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    In the analysis of complex, nonlinear time series, scientists in a variety of disciplines have relied on a time delayed embedding of their data, i.e. attractor reconstruction. The process has focused primarily on heuristic and empirical arguments for selection of the key embedding parameters, delay and embedding dimension. This approach has left several long-standing, but common problems unresolved in which the standard approaches produce inferior results or give no guidance at all. We view the current reconstruction process as unnecessarily broken into separate problems. We propose an alternative approach that views the problem of choosing all embedding parameters as being one and the same problem addressable using a single statistical test formulated directly from the reconstruction theorems. This allows for varying time delays appropriate to the data and simultaneously helps decide on embedding dimension. A second new statistic, undersampling, acts as a check against overly long time delays and overly large embedding dimension. Our approach is more flexible than those currently used, but is more directly connected with the mathematical requirements of embedding. In addition, the statistics developed guide the user by allowing optimization and warning when embedding parameters are chosen beyond what the data can support. We demonstrate our approach on uni- and multivariate data, data possessing multiple time scales, and chaotic data. This unified approach resolves all the main issues in attractor reconstruction.Comment: 22 pages, revised version as submitted to CHAOS. Manuscript is currently under review. 4 Figures, 31 reference

    Aerobic Energy Expenditure Comparisons Between One Traditional and CrossFit-Based Exercise Session

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    This study sought to compare aerobic energy expenditure, recovery VO2, peak heart rate, and peak VO2 achieved across 45 min of exercise and 15 min of recovery performing both traditional and CrossFit®-based exercise. Thirty healthy, physically active participants of both genders (15 men, 15 women) performed a workout following the guidelines of the American College of Sports Medicine (traditional) and a workout following the CrossFit® method. Each workout consisted of a 5 min warm-up (light aerobic exercise and stretching), resistance exercise (both focused on leg exercises), cardiorespiratory exercise (a treadmill run for the traditional exercise and circuit training for the CrossFit®-based exercise) and 5 min cool-down (walking). The cool-down was followed by 10 min of sitting to record recovery values. During each workout the participants wore a K4b2 Cosmed unit to measure energy expenditure and VO2, and a Polar heart rate monitor to measure heart rate. Each measure was compared using a Dependent t-Test. Energy expenditure (468 ± 116 vs. 431 ± 96 kcal, p\u3c0.001), peak heart rate (189 ± 8 vs. 172 ± 8 bpm, p\u3c0.001), peak VO2 (3.22 ± 0.73 vs. 2.81 ± 0.63 L/min, p\u3c0.001) and average 15 min recovery VO2 (0.89 ± 0.24 vs. 0.78 ± 0.18 L/min, p\u3c0.001) were significantly greater in the CrossFit®-based workout. The present study suggests that CrossFit®-based exercise may result in greater aerobic energy expenditure than traditional exercise

    U.S. vs. Microsoft: Did Consumers Win?

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    U.S. v. Microsoft and the related state suit filed in 1998 appear to have concluded. In a unanimous en banc decision issued in late June 2004, the D.C. Circuit Court of Appeals rejected challenges to the remedies specified in a settlement reached in late 2001 and approved by the District Court in November 2002. The wave of dozens of follow-on private antitrust suits filed against Microsoft also appears to be subsiding, following many settlements and some dismissals. Related issues, however, continue to be the focus of competition agencies outside the United States, including the European Union and Korea. In this paper we review the remedies imposed in the United States, in terms of both their relationship to the violations found and their impact on consumer welfare. We conclude that the remedies addressed the violations ultimately found by the Court of Appeals (which were a subset of those found by the original district court and an even smaller subset of the violations alleged, both in court and in public discourse) and went beyond them in important ways. Thus, for those who believe that the courts were right in finding that some of Microsoft's actions harmed competition, the constraints placed on its behavior and the active, ongoing oversight by the Court and the plaintiffs provide useful protection against a recurrence of such harm. For those who believe that Microsoft should not have been found liable, because of insufficient evidence of harm to consumers, the remedies may be unnecessary, but they avoided the serious potential damage to consumer welfare that was likely to accompany the structural remedy imposed by the original district court and the more extreme restrictions on conduct later proposed by some of the state plaintiffs. The remedies imposed appear to have struck a reasonable balance between protecting consumers against the types of actions found illegal, on the one hand, and, on the other hand, avoiding excessive restrictions that would harm consumers by restricting Microsoft's ability to compete in pro-competitive ways.Technology and Industry

    High-Stakes Testing and Student Achievement: Does Accountability Pressure Increase Student Learning?

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    This study examined the relationship between high-stakes testing pressure and student achievement across 25 states. Standardized portfolios were created for each study state. Each portfolio contained a range of documents that told the “story” of accountability implementation and impact in that state. Using the “law of comparative judgments,” over 300 graduate-level education students reviewed one pair of portfolios and made independent evaluations as to which of the two states’ portfolios reflected a greater degree of accountability pressure. Participants’ judgments yielded a matrix that was converted into a single rating system that arranged all 25 states on a continuum of accountability “pressure” from high to low. Using this accountability pressure rating we conducted a series of regression and correlation analyses. We found no relationship between earlier pressure and later cohort achievement for math at the fourth- and eighth-grade levels on the National Assessment of Educational Progress tests. Further, no relationship was found between testing pressure and reading achievement on the National Assessment of Education Progress tests at any grade level or for any ethnic student subgroup. Data do suggest, however, that a case could be made for a causal relationship between high-stakes testing pressure and subsequent achievement on the national assessment tests—but only for fourth grade, non-cohort achievement and for some ethnic subgroups. Implications and directions for future studies are discussed

    Effects of various fat sources on growth performance of finishing pigs

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    One hundred and twenty-eight finishing pigs averaging 124 lb were utilized to evaluate the effects of different fat sources on growth performance. Pigs were fed one of four diets containing either no added fat (control) or 4% added fat from soybean oil, coconut oil, or choice white grease. The control diet was formulated to contain 14.5 % crude protein and .66 % lysine. All fat-added diets were formulated with the same calorie:lysine ratio as the control diet. There were no differences in average daily gain between pigs fed either the control diet or diets containing added fat. Daily feed intake was reduced for pigs fed added fat from 4 to 7% compared to pigs fed no added fat, with pigs fed choice white grease having the lowest feed intake. This resulted in pigs fed choice white grease having 11% better feed efficiency compared to pigs fed no added fat. Pigs fed soybean oil exhibited a 4% improvement in feed efficiency, and those fed coconut oil were intermediate, with an 8% improvement in feed efficiency. These results indicate that 4% added fat reduces feed intake and improves feed efficiency of finishing pigs. In addition, it appears that choice white grease may be a superior fat source in finishing pig diets.; Swine Day, Manhattan, KS, November 16, 198

    The Relationship of Physiological and Fitness Variables to Performance in CrossFit®-based Exercise: Preliminary Findings

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    CrossFit® is a rapidly expanding exercise program as well as an emerging competitive sport. Little is known regarding the correlation of physical fitness measures and performance in CrossFit®-based events. PURPOSE: The purpose of this study was to determine the relationship between various physiological and fitness variables and performance in a typical CrossFit®-based workout. METHODS: Nine male participants (age = 32.2 ± 3.6 yrs; height = 173.1 ± 9.8 cm; weight = 86.1 ± 11.6 kg; BMI = 28.6 ± 1.2 kg/m2) who had performed CrossFit® as their primary exercise program at least 3 days/week for the past 12 months were recruited. Participants performed a test of maximal aerobic fitness (VO2max), a Wingate test, a DEXA scan, a 1RM Clean and Jerk, and a series of exercises that would typically be included in a CrossFit®-based workout. More specifically, participants performed 15 Wall Ball exercises (20 lbs.), 15 Box Jumps (24 in.), 10 Burpees over a barbell, and 10 Kipping Pullups. If all exercises were completed, the participants repeated the exercises in the same order. The participants were asked to stop after 12 min, and the total number of repetitions completed was recorded. Questions regarding the participants’ exercise history and dietary habits were asked. Spearman’s correlation was used to identify relationships between the variables and performance (number of repetitions completed) during the CrossFit®-based workout. Participants were also grouped into “high” (≥ median) or “low” (\u3c median) groups, and independent samples t-tests were used to compare how each group performed during the CrossFit®-based workout. Statistical significance was set at .05. RESULTS: Performance during the CrossFit®-based workout had strong, positive relationships with strength-to-body weight ratio (r = .686; p = .041), 1RM Clean and Jerk (r = .915; p = .001), and years of experience (r = .869; p = .002). Participants with higher strength-to-body weight ratios (p = .036), lower fatigue index (p = .022), lower body fat percentage (p = .022), higher weight lifted during the 1RM Clean and Jerk (p = .017), and more years of experience (p = .027) completed more repetitions during the CrossFit®-based workout. Significance was not found with any other variable. CONCLUSION: Based on these early findings, anaerobic fatigue resistance, body fat percentage, muscular power, and exercise history appear to be significant predictors of performance in CrossFit®-based workouts
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