Quality assurance for digital learning object repositories: issues for the metadata creation process

Metadata enables users to find the resources they require, therefore it is an important component of any digital learning object repository. Much work has already been done within the learning technology community to assure metadata quality, focused on the development of metadata standards, specifications and vocabularies and their implementation within repositories. The metadata creation process has thus far been largely overlooked. There has been an assumption that metadata creation will be straightforward and that where machines cannot generate metadata effectively, authors of learning materials will be the most appropriate metadata creators. However, repositories are reporting difficulties in obtaining good quality metadata from their contributors, and it is becoming apparent that the issue of metadata creation warrants attention. This paper surveys the growing body of evidence, including three UK-based case studies, scopes the issues surrounding human-generated metadata creation and identifies questions for further investigation. Collaborative creation of metadata by resource authors and metadata specialists, and the design of tools and processes, are emerging as key areas for deeper research. Research is also needed into how end users will search learning object repositories

Cracked Up Sentencing: The Establishment and Maintenance of Discrepancies in Federal Cocaine Sentencing Structures in the 1980s and 1990s

During his tenure in office, Ronald Reagan mounted a punitive war against drug use in the United States. This crusade included the vast sentencing discrepancy between powder and crack cocaine, which is the focus of this study. Despite their identical chemical makeup, it took 500 grams of powder cocaine to warrant a minimum five-year sentence and only five grams of crack cocaine to trigger the same sentence. Misconceived notions that crack cocaine was instantly additive, incited violence among its users, and preyed disproportionally on the young and poor drove politicians to set mandatory minimums for crack cocaine 100 times harsher than powder cocaine. Lawmakers assumed drug criminals contained an innate deviance or criminality, which drove them to their drug use, justifying these harsh penalties and the lack of empathy extended to these so-called criminals. However, an examination of psychological studies on drug use and abuse reveal that emotional deregulation and trauma are common predictors of drug abuse. Interviews with incarcerated women underscore these findings, as many of these women—convicted of non-violent drug crimes—identify their use of drugs as a coping mechanism rather than an exercise in social deviance. Using psychological and sociological studies in conjuncture with testimonies of incarcerated women, this study seeks to combat these notions held by lawmakers to demonstrate the inherent flaws of Reagan's drug war. Similarly, this study looks to rap lyrics of the 1980 and1990s as a cultural lens into the communities most negatively affected by the drug war. In tracing the cultural history of these communities, the necessity of this study is revealed as it exposes the human casualties of the drug war. The choice to highlight crack cocaine sentencing rather than examine the war on drugs writ large is done to examine the deliberations and choices of lawmakers in their policy decisions and attempt to locate culpability for the mass incarceration crisis. Doing so reveals that biased police practices more so than the laws the enforce are responsible for the disproportionate number of incarcerate Black Americans; law enforcement officials, however, cannot be held fully responsible as President Reagan, Clinton, and Congress all worked dutifully to ensure that individuals convicted of drug crimes remained in prison for years on end rather than enter into treatment programs

MS 204 Guide to Sara Ann Barton\u27s Lithium and Trace Metal Research Papers (Created April 4 - November 8, 2015)

The Sara Ann Barton\u27s Lithium and Trace Metal research papers includes research material, reprints, environmental reports, questionnaires, and notes from Barton’s research on lithium and trace metals. Some material is in Spanish. See more at MS 204

Pterodactyl: Control Architectures Development for Integrated Control Design of a Mechanically Deployed Entry Vehicle

The need to return high mass payloads is driving the development of a new class of vehicles, Deployable Entry Vehicles (DEV) for which feasible and optimized control architectures have not been developed. The Pterodactyl project, seeks to advance the current state-of-the-art for entry vehicles by developing a design, test, and build capability for DEVs that can be applied to various entry vehicle configurations. This paper details the efforts on the NASA-funded Pterodactyl project to investigate multiple control techniques for the Lifting Nano-ADEPT (LNA) DEV. We design and implement multiple control architectures on the LNA and evaluate their performance in achieving varying guidance commands during entry.First we present an overview of DEVs and the Lifting Nano-ADEPT (LNA), along with the physical LNA configuration that influences the different control designs. Existing state-of-the-art for entry vehicle control is primarily propulsive as reaction control systems (RCS) are widely employed. In this work, we analyze the feasibility of using both propulsive control systems such as RCS to generate moments, and non-propulsive control systems such as aerodynamic control surfaces and internal moving mass actuations to shift the LNA center of gravity and generate moments. For these diverse control systems, we design different multi-input multi-output (MIMO) state-feedback integral controllers based on linear quadratic regulator (LQR) optimal control methods. The control variables calculated by the controllers vary, depending on the control system being utilized and the outputs to track for the controller are either the (i) bank angle or the (ii) angle of attack and sideslip angle as determined by the desired guidance trajectory. The LQR control design technique allows the relative allocation of the control variables through the choice of the weighting matrices in the cost index. Thus, it is easy to (i) specify which and how much of a control variable to use, and (ii) utilize one control design for different control architectures by simply modifying the choice of the weighting matrices.By providing a comparative analysis of multiple control systems, configurations, and performance, this paper and the Pterodactyl project as a whole will help entry vehicle system designers and control systems engineers determine suitable control architectures for integration with DEVs and other entry vehicle types

Water and Climate Risks Facing U.S. Corn Production: How Companies and Investors Can Cultivate Sustainability

U.S. corn farmers are among the most productive in the world, generating a record harvest of nearly 14 billion bushels in 2013 -- enough corn to fill a freight train long enough to circle the Earth. This production supports a mammoth agricultural sector comprised not just of farmers, but also major food, meat and energy companies that have an enormous stake in the long-term productivity and resilience of American agriculture. However, in the face of this bounty, three major threats to U.S. corn production loom: climate change, unsustainable water use and inefficient and damaging fertilizer practices.Ceres' new report analyzes the risks facing U.S. corn production. The report provides recommendations for how corn-buying companies and their investors can catalyze more sustainable agricultural practices, while helping farmers preserve and enhance yields, and protect precious water resources. The research is accompanied by new data and interactive maps that highlight irrigation risks and fertilizer pollution hotspots

Pterodactyl: Development and Comparison of Control Architectures for a Mechanically Deployed Entry Vehicle

The Pterodactyl project, seeks to advance the current state-of-the-art for entry vehicles by developing novel guidance and control technologies for Deployable Entry Vehicles (DEVs) that can be applied to various entry vehicle configurations. This paper details the efforts on the NASA-funded Pterodactyl project to investigate and implement multiple control techniques for an asymmetric mechanical DEV. We design multiple control architectures for a Pterodactyl Baseline Vehicle (PBV) and evaluate their performance in achieving varying guidance commands during entry. The control architectures studied are (i) propulsive control systems such as reaction control systems and (ii) non-propulsive control systems such as aerodynamic control surfaces and internal moving masses. For each system, state-feedback integral controllers based on linear quadratic regulator (LQR) optimal control methods are designed to track guidance commands of either (i) bank angle or (ii) angle of attack and sideslip angle as determined by the desired guidance trajectory. All control systems are compared for a lunar return reference mission and by providing a comparative analysis of these systems, configurations, and performance, the efforts detailed in this paper and the Pterodactyl project as a whole will help entry vehicle system designers determine suitable control architectures for integration with DEVs and other entry vehicle types

Comparing clinical outcomes of piperacillin-tazobactam administration and dosage strategies in critically ill adult patients : a systematic review and meta-analysis

Abstract: Background: Recently, continuous administration of piperacillin-tazobactam has been proposed as a valuable alternative to traditional intermittent administration especially in critically ill patients. However, antibiotic dosing remains a challenge for clinicians as antibiotic dosing regimens are usually determined in non-critically ill hospitalized adult patients. The aim was to conduct a systematic review to identify and highlight studies comparing clinical outcomes of piperacillin tazobactam dosing regimens, continuous/prolonged infusion vs intermittent infusion in critically ill patients. Meta-analyses were performed to assess the overall effect of dosing regimen on clinical efficacy. Methods: Studies were identified systematically through searches of PubMed and Science Direct, in compliance with PRISMA guidelines. Following the systematic literature review, meta-analyses were performed using Review Manager. Results: Twenty-three studies were included in the analysis involving 3828 critically ill adult participants in total (continuous/prolonged infusion = 2197 and intermittent infusion = 1631) from geographically diverse regions. Continuous/prolonged resulted in significantly: higher clinical cure rates (Odds Ratio 1.56, 95% Confidence Interval 1.28–1.90, P = 0 .0001), lower mortality rates (Odds Ratio 0.68, 95% Confidence Interval 0.55–0.84, P = 0 .0003), higher microbiological success rates (Odds Ratio 1.52, 95% Confidence Interval 1.10–2.11, P = 0.01) and decreasing the length of hospital stay (Mean Difference − 1.27, 95% Confidence Interval − 2.45—0.08, P = 0.04) in critically ill patients. Conclusion: Results from this study show that there is a significant level of evidence that clinical outcome in critically ill patients is improved in patients receiving piperacillin-tazobactam via continuous/prolonged infusion. However, more rigorous scientific studies in critically ill patients are warranted to reach a sufficient level of evidence and promote further implementation of C/PI as a dosing strategy

Comparing clinical outcomes of piperacillin-tazobactam administration and dosage strategies in critically ill adult patients : a systematic review and meta-analysis

Abstract Background: Recently, continuous administration of piperacillin-tazobactam has been proposed as a valuable alternative to traditional intermittent administration especially in critically ill patients. However, antibiotic dosing remains a challenge for clinicians as antibiotic dosing regimens are usually determined in non-critically-ill hospitalized adult patients. The aim was to conduct a systematic review to identify and highlight studies comparing clinical outcomes of piperacillin tazobactam dosing regimens, continuous/prolonged infusion vs intermittent infusion in critically ill patients. Meta-analyses were performed to assess the overall effect of dosing regimen on clinical efficacy. Methods: Studies were identified systematically through searches of PubMed and Science Direct, in compliance with PRISMA guidelines. Following the systematic literature review, meta-analyses were performed using Review Manager. Results: Twenty-three studies were included in the analysis involving 3828 critically ill adult participants in total (continuous/prolonged infusion = 2197 and intermittent infusion = 1631) from geographically diverse regions. Continuous/prolonged resulted in significantly: higher clinical cure rates (OR 1.56, 95% C.I 1.28-1.90, P = 0 .0001), lower mortality rates (OR 0.68, 95% C.I 0.55-0.84, P = 0 .0003), higher microbiological success rates (OR 1.52, 95% C.I 1.10-2.11, P = 0.01) and decreasing the length of hospital stay (OR -1.27, 95% C.I -2.45—0.08, P = 0.04) in critically ill patients. Conclusion: There is a significant level of evidence that clinical outcome in critically ill patients is improved in patients receiving piperacillin-tazobactam via continuous/prolonged infusion. Therefore, this alternative infusion strategy could be recommended in clinical practice