Towards optimal simulations of formulas by bounded-width programs

We show that, over an arbitrary ring, for any fixed >0, all balanced algebraic formulas of sizes are computed by algebraic straight-line programs that employ a constant number of registers and have lengthO (s ¹⁺). In particular, in the special case where the ring isGF(2), we obtain a technique for simulating balanced Boolean formulas of sizes by bounded-width branching programs of lengthO(s ¹⁺), for any fixed >0. This is an asymptotic improvement in efficiency over previous simulations in both the Boolean and algebraic settings.     

Identification and Optimization of the First Highly Selective GLUT1 Inhibitor BAY‐876

Despite the long‐known fact that the facilitative glucose transporter GLUT1 is one of the key players safeguarding the increase in glucose consumption of many tumor entities even under conditions of normal oxygen supply (known as the Warburg effect), only few endeavors have been undertaken to find a GLUT1‐selective small‐molecule inhibitor. Because other transporters of the GLUT1 family are involved in crucial processes, these transporters should not be addressed by such an inhibitor. A high‐throughput screen against a library of ～3 million compounds was performed to find a small molecule with this challenging potency and selectivity profile. The N‐(1H‐pyrazol‐4‐yl)quinoline‐4‐carboxamides were identified as an excellent starting point for further compound optimization. After extensive structure–activity relationship explorations, single‐digit nanomolar inhibitors with a selectivity factor of >100 against GLUT2, GLUT3, and GLUT4 were obtained. The most promising compound, BAY‐876 [N⁴‐[1‐(4‐cyanobenzyl)‐5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐4‐yl]‐7‐fluoroquinoline‐2,4‐dicarboxamide], showed good metabolic stability in vitro and high oral bioavailability in vivo.     

Universal intervention effects on substance use among young adults mediated by delayed adolescent substance initiation.

In this article, the authors examine whether delayed substance initiation during adolescence, achieved through universal family-focused interventions conducted in middle school, can reduce problematic substance use during young adulthood. Sixth-grade students enrolled in 33 rural midwestern schools and their families were randomly assigned to 3 experimental conditions. Self-report questionnaires provided data at 7 time points for the Iowa Strengthening Families Program (ISFP), Preparing for the Drug Free Years (PDFY), and control groups through young adulthood. Five young adult substance frequency measures (drunkenness, alcohol-related problems, cigarettes, illicit drugs, and polysubstance use) were modeled as distal outcomes affected by the average level and rate of increase in substance initiation across the adolescent years in latent growth curve analyses. Results show that the models fit the data and that they were robust across outcomes and interventions, with more robust effects found for ISFP. The addition of direct intervention effects on young adult outcomes was not supported, suggesting long-term effects were primarily indirect. Relative reduction rates were calculated to quantify intervention-control differences on the estimated proportion of young adults indicating problematic substance use; they ranged from 19% to 31% for ISFP and from 9% to 16% for PDFY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Helium Adsorption on Lithium Substrates

We have developed a cryogenic pulsed laser deposition (PLD) system to deposit lithium films onto a quartz crystal microbalance (QCM) at 4 K. Adsorption isotherms of ⁴He on lithium were measured in the temperature range between 1.42 K and 2.5 K. The isotherms are qualitatively different from isotherms on strong substrates such as gold and weak substrates such as cesium. There is no evidence of the formation of solid-like layers of helium, and the helium coverage is approximately linear in the pressure over a wide range. By measuring the low coverage slope of the isotherms, the binding energy of helium to lithium was found to be approximately −13.6 K. For lithium substrates less than approximately 100 layers thick, the chemical potential at which the superfluid transition was observed was surprisingly sensitive to the details of lithium deposition. This work was supported by NSF grant DMR 0509685.     

Assessing a public health approach to delay onset and progression of adolescent substance use: Latent transition and log-linear analyses of longitudinal family preventive intervention outcomes.

This study examined the effects of the Iowa Strengthening Families Program (ISFP) and the Preparing for the Drug-Free Years program (PDFY) on young adolescent transitions from nonuse of substances to initiation and progression of substance use. Analyses incorporated 3 waves of data collected over a 2.5-year period from 329 rural young adolescents. Outcomes were analyzed by using log-linear models that incorporated substance use status frequencies derived from latent transition analyses. Effects on delayed substance use initiation were shown for both the ISFP and the PDFY at a 2-year follow-up. Also at this follow-up, the PDFY showed effects on delayed progression of use among those previously reporting initiation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

超临界流体染色技术的过去、现在和将来(一)

介绍了超临界CO2染色技术在世界范围的发展过程及其优于水染色的特点。阐述了超临界CO2对纤维性能的影响，诸如润滑效果CO2吸附、结晶、收缩和热机械性能，超临界CO2对纤维的玻璃化温度和有效温度以及对纤维损伤的影响。另一重要问题是在超临界CO2中纤维与染料之间的平衡分布和影响染料溶解性的参数。文中给出了涤纶纤维的染色步骤、设备和最佳工艺参数，然而天然纤维的染色仍是一个问题。通过浸渍溶胀剂和交联剂，或在染色前对纤维改性、添加极性共溶剂，可以提高分散染料的染色性，所有这些方法增加了工艺步骤和设备清洗，若使用有机溶剂则将大大提高机器成本，采用活性分散染料可以避免这种情况。含乙烯砜基团的染料主要适宜于羊毛和聚酰胺纤维的超临界CO2染色，而对于纤维素纤维迄今尚未开发可行的解决方法。预计在不久的将来建造工业化规模的染色设备，努力实现超临界CO2染色技术的经济效益。     

The Dyeing of Polyolefin Fibers in Supercritical Carbon Dioxide. Part I: Thermo-mechanical Properties of Polyolefin Fibers after Treatment in CO2 under Dyeing Conditions

The viscoelastic properties of gel-spun polyethylene (PE) and polypropylene (PP) fibers after treatment in supercritical CO₂, at 280 bar were examined to determine the optimum conditions for dyeing without causing fiber damage. Above 100°C, a greater amount of shrinkage, mainly of PP fiber, is observed in CO₂, than in air at 1 bar. Under isothermal conditions at 100°C, pressure-dependent on-line measurements of a PP-fiber monofli up to 280 bar show that shrinkage becomes very considerable at low pressures of only 10 bar. In comparison with isobaric conditions at 280 bar, shrinkage starts at temperatures above 60°C and is greatest between 90 and 100°C. In both cases, the degree of shrinkage is 11–12%. The value of F._max on the stress—strain diagrams of all fibers tested is not influenced by the treatment in CO₂, up to 120°C. However, the elongation increases only for polyolefins with a lower degree of crystallinity to the extent of about 15% for the PP monofil and 13% for the LM-PE fiber. Furthermore, CO₂, is able to penetrate into the hydrophobic PE and PP fibers and acts as a quasi-impurity, reducing the melting point (mp) of LM-PE fibers by between 5 and 7^°C and that of PP monofli by 9 and 22°C at 50 and 280 bar, respectively. This was observed by differential-dynamic-heat-flow calorimetric measurements in CO₂. The decrease in mp of the highly crystalline HM-PE fiber is only 2°C because the diffusion of CO₂ into the fiber is extremely slow.     

Direct and indirect latent-variable parenting outcomes of two universal family-focused preventive interventions: Extending a public health-oriented research base.

Recent literature underscores the need for studies of family-based preventive interventions oriented toward public health objectives. This article illustrates a program evaluation approach for the study of family intervention outcomes in general populations. Thirty-three rural schools were randomly assigned to 1 of 3 conditions: the Preparing for the Drug-Free Years Program (PDFY), the Iowa Strengthening Families Program (ISFP), and a minimal-contact control group. Self-report and observational data collected from 523 families were used to develop measurement models of 3 latent parenting constructs that included measurement method effects. Analyses were conducted to ensure initial and attrition-related group equivalencies and to assess school effects. Structural equation models of the hypothesized sequence of direct and indirect effects for both PDFY and ISFP were then fit to the data. All hypothesized effects were significant for both interventions. The discussion addresses the potential public health benefits of evaluation research on universal preventive interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Model‐Based Visualization of Temporal Abstractions

We describe a new conceptual methodology and related computational architecture called Knowledge‐based Navigation of Abstractions for Visualization and Explanation (KNAVE). KNAVE is a domain‐independent framework specific to the task of interpretation, summarization, visualization, explanation, and interactive exploration, in a context‐sensitive manner, of time‐oriented raw data and the multiple levels of higher level, interval‐based concepts that can be abstracted from these data. The KNAVE domain‐independent exploration operators are based on the relations defined in the knowledge‐based temporal‐abstraction problem‐solving method, which is used to abstract the data, and thus can directly use the domain‐specific knowledge base on which that method relies. Thus, the domain‐specific semantics are driving the domain‐independent visualization and exploration processes, and the data are viewed through a filter of domain‐specific knowledge. By accessing the domain‐specific temporal‐abstraction knowledge base and the domain‐specific time‐oriented database, the KNAVE modules enable users to query for domain‐specific temporal abstractions and to change the focus of the visualization, thus reusing for a different task (visualization and exploration) the same domain model acquired for abstraction purposes. We focus here on the methodology, but also describe a preliminary evaluation of the KNAVE prototype in a medical domain. Our experiment incorporated seven users, a large medical patient record, and three complex temporal queries, typical of guideline‐based care, that the users were required to answer and/or explore. The results of the preliminary experiment have been encouraging. The new methodology has potentially broad implications for planning, monitoring, explaining, and interactive data mining of time‐oriented data.