Evaluating the collaborative strategic reading intervention: An overview of randomized controlled trial options

When attempting to determine if an intervention has a causal impact, the ‘gold standard’ of program evaluation.is the randomized controlled trial (RCT). In education studies random assignment is rarely feasible at the.student level, making RCTs harder to conduct. School-level assignment is more common but this often.requires considerable resources compared to designs where classrooms can be assigned within a school. This.article describes the costs and benefits of testing the effects of a classroom based instructional intervention.using the multi-site cluster RCT. Topics covered include a discussion of various design options, statistical.power, contamination, prior evidence, generalizability of results, ease of recruitment and need for data.collection. The purpose of the article is to inform practice by providing program evaluators with an in-depth.look at various RCT design options that were considered when searching for a way to efficiently evaluate a.school-based intervention. Accessed 15,611 times on https://pareonline.net from January 28, 2009 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Universal fluctuations in subdiffusive transport

Subdiffusive transport in tilted washboard potentials is studied within the fractional Fokker-Planck equation approach, using the associated continuous time random walk (CTRW) framework. The scaled subvelocity is shown to obey a universal law, assuming the form of a stationary Levy-stable distribution. The latter is defined by the index of subdiffusion alpha and the mean subvelocity only, but interestingly depends neither on the bias strength nor on the specific form of the potential. These scaled, universal subvelocity fluctuations emerge due to the weak ergodicity breaking and are vanishing in the limit of normal diffusion. The results of the analytical heuristic theory are corroborated by Monte Carlo simulations of the underlying CTRW

Nasal intermittent positive pressure ventilation in acute exacerbations of chronic obstructive pulmonary disease — a preliminary study

AbstractTen patients (two male) suffering from acute exacerbations of long-standing chronic obstructive pulmonary disease and admitted in hypoxic, hypercapnic respiratory failure were treated with Nasal Intermittent Positive Pressure Ventilation (NIPPV) plus supplemental oxygen, on a general medical ward. The median (range) pH on admission was 7·30 (7·20–7·35), the median age was 67 years (47–77) with an FEV1 (percent of predicted) of 30 (17–39). On admission the median arterial oxygen tension (PaO2) was 4·71 kPa (3·45–6·26) on air, and the carbon dioxide tension (PaCO2) was 7·68 kPa (6·85–9·83). With controlled oxygen therapy there was no significant improvement in PaO2, but the median PaCO2 increased significantly to 9·75 kPa (7·04–11·70) (P < 0·05). By using NIPPV with supplemental oxygen it was possible to significantly improve the median PaO2 to 11·25 kPa (6·70–26·90) (P < 0·01) without worsening PaCO2 levels (8·96 kPa; 6·85–13·10). NIPPV was applied by a senior, respiratory physiotherapist and used intermittently depending on patient tolerance and clinical response. The median total time on NIPPV was 27 h, delivered over 1–5 days. One patient found the mask difficult to tolerate beyond a short period of time. NIPPV was well accepted on a general ward by nursing staff. Three patients later died with progressive hypercapnia, despite an initial response; with one of these patients also receiving intubation and mechanical ventilation. A further patient also received intubation and mechanical ventilation and was eventually discharged.NIPPV plus supplemental oxygen offers a method to correct hypoxaemia on a general medical ward without worsening hypercapnia for acute on chronic, hypoxic, hypercapnic respiratory failure, and warrants further investigation

Errors in Computational Complexity Proofs for Protocols

Proofs are invaluable tools in assuring protocol implementers about the security properties of protocols. However, several instances of undetected flaws in the proofs of protocols (resulting in flawed protocols) undermine the credibility of provably-secure protocols. In this work, we examine several protocols with claimed proofs of security by Boyd &amp; Gonzalez-Nieto (2003), Jakobsson &amp; Pointcheval (2001), and Wong &amp; Chan (2001), and an authenticator by Bellare, Canetti, &amp; Krawczyk (1998). Using these protocols as case studies, we reveal previously unpublished flaws in these protocols and their proofs. We hope our analysis will enable similar mistakes to be avoided in the future

Online Learning and Resource-Bounded Dimension: Winnow Yields New Lower Bounds for Hard Sets

We establish a relationship between the online mistake-bound model of learning and resource-bounded dimension. This connection is combined with the Winnow algorithm to obtain new results about the density of hard sets under adaptive reductions. This improves previous work of Fu (1995) and Lutz and Zhao (2000), and solves one of Lutz and Mayordomo&apos;s &quot;Twelve Problems in Resource-Bounded Measure&quot; (1999)

Dimension is compression

Effective fractal dimension was defined by Lutz (2003) in order to quantitatively analyze the structure of complexity classes. Interesting connections of effective dimension with information theory were also found, in fact the cases of polynomial-space and constructive dimension can be precisely characterized in terms of Kolmogorov complexity, while analogous results for polynomial-time dimension haven’t been found. In this paper we remedy the situation by using the natural concept of reversible time-bounded compression for finite strings. We completely characterize polynomial-time dimension in terms of polynomial-time compressors.

Dimension characterizations of complexity classes

We use derandomization to show that sequences of positive pspace-dimension – in fact, even positive ∆ p k-dimension for suitable k – have, for many purposes, the full power of random oracles. For example, we show that, if S is any binary sequence whose ∆ p 3-dimension is positive, then BPP ⊆ PS and, moreover, every BPP promise problem is PS-separable. We prove analogous results at higher levels of the polynomial-time hierarchy. The dimension-almost-class of a complexity class C, denoted by dimalmost-C, is the class consisting of all problems A such that A ∈ CS for all but a Hausdorff dimension 0 set of oracles S. Our results yield several characterizations of complexity classes, such as BPP = dimalmost-P, Promise-BPP = dimalmost-P-Sep, and AM = dimalmost-NP, that refine previously known results on almost-classes.