cssi/SciSciGPT-SciSciNet huggingface dataset:
Promoting computational thinking through project-based learning

This paper introduces project-based learning (PBL) features for developing technological, curricular, and pedagogical supports to engage students in computational thinking (CT) through modeling. CT is recognized as the collection of approaches that involve people in computational problem solving. CT supports students in deconstructing and reformulating a phenomenon such that it can be resolved using an information-processing agent (human or machine) to reach a scientifically appropriate explanation of a phenomenon. PBL allows students to learn by doing, to apply ideas, figure out how phenomena occur and solve challenging, compelling and complex problems. In doing so, students take part in authentic science practices similar to those of professionals in science or engineering, such as computational thinking. This paper includes 1) CT and its associated aspects, 2) The foundation of PBL, 3) PBL design features to support CT through modeling, and 4) a curriculum example and associated student models to illustrate how particular design features can be used for developing high school physical science materials, such as an evaporative cooling unit to promote the teaching and learning of CT.
The End of Socialism

Dr. Jim Otteson's presentation will be based on his recently released book The End of Socialism, which explores socialism as a system of political economy – that is, from the perspectives of both moral philosophy and economic theory. His book examines the exact nature of the practical difficulties socialism faces, which turn out to be greater than one might initially suppose, and then asks whether the moral ideals it champions – equality, fairness, and community – are important enough to warrant attempts to overcome these difficulties nonetheless, especially in light of the alleged moral failings of capitalism. The result is an examination of the "end of socialism," both in the sense of the moral goals it proposes and in the results of its unfolding logic. Dr. Otteson joined the Wake Forest University School of Business in the Fall of 2013 as Executive Director of the BB&T Center for the Study of Capitalism and Teaching Professor of Political Economy.
The Impact of Traffic Congestion on Accessibility

Accessibility is a widely used term. In transportation, it can refer to a traveler’s physical or economic ability in using a given travel mode; it can refer to describe a traveler’s access to one or more destination opportunities available within a specific distance, travel time, or travel cost from the traveler’s origin; or it can be used by the marketing department of a retail store chain to describe/quantify the number potential customers within a 20 min travel time to a store.
APC determines histone deacetylases inhibitor-induced apoptosis in colon cancer cells

Proc Amer Assoc Cancer Res, Volume 47, 2006 4638 Inhibitors of histone deacetylases (HDAC) are promising new drugs for various types of cancers. These agents inhibit malignant cell growth and induce apoptosis through unknown mechanisms. Here we report that the expression status of adenomatous polyposis coli (APC) protein determines whether colon cancer cells undergo apoptosis when treated with HDAC inhibitor Valproic acid (VPA). We used three colon cancer cell lines, LS174-T (expressing wild-type APC and β-catenin), SW620 and HT-29 (both expressing mutant APC), to investigate the role of APC in cell death induced by VPA. VPA induced apoptosis in LS174-T cells but not in SW620 or HT-29 cells. When wild-type APC protein was expressed using an inducible expression system, HT-29 cells underwent apoptosis in response to VPA. Conversely, knocking-down of APC protein by siRNA rendered LS174-T cells resistant to VPA-induced apoptosis. APC mediated VPA-induced apoptosis through down-regulation of Survivin. The level of Survivin protein decreased after VPA treatment in LS174-T and HT-29/APC cells, but not in SW620 and HT-29/β-Gal cells. While knocking-down of Survivin by siRNA sensitized SW620 cells to VPA-induced apoptosis, overexpression of Survivin blocked VPA-induced apoptosis in LS174-T cells. The data suggest that APC is a critical determinant of VPA-induced apoptosis in colon cancer cells and Survivin is a potential target to enhance cell death induced by VPA. As APC is frequently mutated in human colon cancers, these results have clear clinical indications.
The differential diagnosis of ritual abuse allegations

Objective: Because psychiatrics do not have a consistent way to classify and define the forms of child abuse that may be mistaken for ritual abuse, the objective of this paper is to create a comprehensive differential diagnosis of allegations of ritual abuse. Method: The authors reviewed 60 articles, chapters, and books that contained allegations of ritual abuse or behaviors that might be mistaken for ritual abuse, that were made by patients or caretakers. Results: This paper clarifies the behaviors that represent or may be mistaken for ritual abuse: Cult-based ritual abuse, pseudoritualistic abuse, activities by organized satanic groups, repetitive psychopathological abuse, sexual abuse by pedophiles, child pornography portraying ritual abuse, distorted memory, false memory, false report due to a severe mental disorder, pseudologia phantastica, adolescent behavior simulating ritual abuse, epidemic hysteria, deliberate lying, and hoaxes. Conclusions: The differential diagnosis of allegations of ritual abuse is important in both clinical and forensic psychiatry. In some cases, it will not be possible to tell whether a particular allegation is factual or what the underlying mental processes are. It is important to separate the role of the mental health professional as therapist from the role as an expert witness in court.
Prize-Collecting Survivable Network Design in Node-Weighted Graphs

We consider node-weighted network design problems, in particular the survivable network design problem (SNDP) and its prize-collecting version (PC-SNDP). The input consists of a node-weighted undirected graph G = (V,E) and integral connectivity requirements r(st) for each pair of nodes st. The goal is to find a minimum node-weighted subgraph H of G such that, for each pair st, H contains r(st) edge-disjoint paths between s and t. PC-SNDP is a generalization in which the input also includes a penalty π(st) for each pair, and the goal is to find a subgraph H to minimize the sum of the weight of H and the sum of the penalties for all pairs whose connectivity requirements are not fully satisfied by H. Let k = max st r(st) be the maximum requirement. There has been no non-trivial approximation for node-weighted PC-SNDP for k > 1, the main reason being the lack of an LP relaxation based approach for node-weighted SNDP. In this paper we describe multiroute-flow based relaxations for the two problems and obtain approximation algorithms for PC-SNDP through them. The approximation ratios we obtain for PC-SNDP are similar to those that were previously known for SNDP via combinatorial algorithms. Specifically, we obtain an O(k 2 logn)-approximation in general graphs and an O(k 2)-approximation in graphs that exclude a fixed minor. The approximation ratios can be improved by a factor of k but the running times of the algorithms depend polynomially on n k .
Syntagmatic and paradigmatic dimensions of causee encodings

There have been essentially two types of theoretical approaches to account for the grammatical relations associated with the causee argument of causative constructions. Ignoring the specifics of particular theories, there are transitivity based approaches in which the causee is a direct object when the embedded clause is intransitive, and an indirect object or oblique when the embedded clause is transitive. This pattern finds considerable cross-linguistic support. On the other hand, there are languages in which the causee exhibits alternative grammatical relations irrespective of transitivity: the causee direct object correlates with direct causation, while indirect object or oblique causees are associated with indirect causation. Such phenomena have motivated a semantic approach.
A Model for Location of Capacitated Alternative-Fuel Stations

Increased interest in alternative fuels is attributable, in part, to rising oil prices and increasing concern about global warming. A lack of a refueling infrastructure, however, has inhibited the adoption of alternative-fuel vehicles. Little economic incentive exists to mass-produce alternative-fuel vehicles until a network of stations exists that can refuel a reasonable number of trips. The flow refueling location model (FRLM) was developed to minimize the investment necessary to create a refueling infrastructure by optimizing the location of fueling stations. The original uncapacitated FRLM assumes that the presence of a refueling station is sufficient to serve all flows passing through a node, regardless of their volume. This article introduces the capacitated flow refueling location model that limits the number of vehicles refueled at each station. It also introduces a modified objective function maximizing vehicle-miles traveled instead of trips, applies both models to an intercity network for Arizona, and formulates several other extensions. El creciente interes por combustibles alternativos es atribuible en parte al incremento del precio del petroleo y a la preocupacion por el calentamiento global. La insuficiente infraestructura de estaciones de servicio de dichos combustibles ha inhibido la adopcion de vehiculos que los usan. Por otro lado, hay pocos incentivos economicos para producir estos vehiculos, por lo menos hasta que se establezca una red de estaciones que permita el reabastecimiento de combustibles alternativos y a la vez minimice el numero de viajes. El modelo de localizacion de flujo y reabastecimiento (FRLM) fue desarrollado por los autores para minimizar la inversion necesaria para crear una infraestructura de reabastecimiento por medio de la optimizacion de la ubicacion de las estaciones. En su version original, el FRLM asume que la presencia de una estacion es suficiente para (re)abastecer la demanda de todos los flujos (vehiculos) que atraviesan dicho nodo de la red sin importar el volumen del flujo en si. El presente articulo propone el uso de nuevo modelo: el CFRLM, el cual pone un limite al numero de vehiculos que pueden ser abastecidos por cada estacion. Asimismo, el modelo sugerido presenta una modificacion a la funcion objetivo que maximiza el numero de millas recorridas en lugar del numero de viajes. Ambos modelos son aplicados a la red vial que conecta varias ciudades del estado de Arizona (EEUU). Adicionalmente se presentan diversas variaciones y extensiones a los modelos que permiten y sugieren futuras aplicaciones. 石油价格的上涨和对全球变暖问题愈来愈多的关注，某种程度上导致了人们对可替代性燃料的重视。然而，替代燃料供给基础设施的缺乏，制约了使用替代燃料的交通工具的推广。除非建立合理的替代燃料供给站网络，否则对替代燃料车辆的大规模生产的经济推动作用甚微。流量加油选址模型(FRLM) 通过对燃料供给站选址的优化，使得建造燃料供给基础设施的投资最小。原来的FRLM模型没有容量限制，即假定不论行经车辆的实际需求量有多大，任何一个加油点均能提供足够多的燃料以满足其需求。本文引入了一种具有容量限制的流量加油选址模型（CFRLM）,能够对每个加油站的加油车辆数目进行限制。此外，本文还提出了一种改进的目标函数对车辆行驶里程而非行程求最大值，并将这两种模型应用于亚利桑那州城市间的加油站网络分析。作者还阐述了在其它一些方面的推广应用。
Independent effects of error magnification and field of view on compensatory tracking performance.

This experiment evaluated the independent effects of error magnification and field of view on compensatory tracking performance. Both display and optical magnification were investigated. In general, the results demonstrated that: (1) the facilitative effect on performance of display magnification was primarily due to the concomitant field of view reduction and not magnification per se; (2) optical magnification facilitated performance but subsequent display gain increases had no further affect; (3) regardless of visual mode employed, optimum performance levels on a complex trajectory converged at approximately the same field of view. In was suggested that increasing the optical gain or decreasing the field of view resulted in subjects reducing their reaction times to target movements. No evidence was found which indicated that magnification facilitated visual perception.
Flow cytometric analysis of heterogeneity in blood group-related antigen expression in a human urinary bladder carcinoma cell line, 647V.

Abstract Previous immunohistological studies showed a relationship between expression of blood group-related antigens (BG-Ag) and invasive potential in human urinary bladder carcinoma, but the marked variability of antigen staining within many individual tumors has obscured the biological basis of this finding. We studied the expression of the A, H, and T (Thomsen-Friedenreich) BG-Ag by flow cytometry in a human bladder carcinoma cell line (647V) using fluoresceinated BG-Ag-specific lectins (Dolichos bifloris, Ulex europaeus, and Arachis hypogaea). Cell cycle compartments were quantitated by flow cytometry using propidium iodide staining. Expression of all three antigens was highly variable, but staining for each antigen produced a distinct profile. T antigen expression appeared independent of A or H antigen expression. Cell populations sorted by T antigen expression showed heritable antigenic differences persistent over many weeks in culture. However, much of the T antigen variability was nonheritable, since the stable staining profiles of the sorted cells were intermediate between the parental and the profiles obtained immediately after sorting. The nonheritable antigenic variation did not appear entirely explainable by cell size or cell cycle fluctuation. These results were confirmed by isolating 64 clones from the dim part of the T antigen staining profile, 19 of which had a persistently dim phenotype. The variability of BG-Ag expression by human bladder carcinoma cells in vitro may explain the staining patterns observed in the study of antigen expression in resected human bladder carcinomas.
A hybrid feature selection approach for microarray gene expression data

Due to the huge number of genes and comparatively small number of samples from microarray gene expression data, accurate classification of diseases becomes challenging. Feature selection techniques can improve the classification accuracy by removing irrelevant and redundant genes. However, the performance of different feature selection algorithms based on different theoretic arguments varies even when they are applied to the same data set. In this paper, we propose a hybrid approach to combine useful outcomes from different feature selection methods through a genetic algorithm. The experimental results demonstrate that our approach can achieve better classification accuracy with a smaller gene subset than each individual feature selection algorithm does.
Crystal Structure of the Putidaredoxin Reductase·Putidaredoxin Electron Transfer Complex

In the camphor monooxygenase system from Pseudomonas putida, the [2Fe-2S]-containing putidaredoxin (Pdx) shuttles electrons between the NADH-dependent putidaredoxin reductase (Pdr) and cytochrome P450cam. The mechanism of the Pdr·Pdx redox couple has been investigated by a variety of techniques. One of the exceptions is x-ray crystallography as the native partners associate weakly and resist co-crystallization. Here, we present the 2.6-Å x-ray structure of a catalytically active complex between Pdr and Pdx C73S/C85S chemically cross-linked via the Lys409Pdr-Glu72Pdx pair. The 365 Å2 Pdr-Pdx interface is predominantly hydrophobic with one central Arg310Pdr-Asp38Pdx salt bridge, likely assisting docking and orienting the partners optimally for electron transfer, and a few peripheral hydrogen bonds. A predicted 12-Å-long electron transfer route between FAD and [2Fe-2S] includes flavin flanking Trp330Pdr and the iron ligand Cys39Pdx. The x-ray model agrees well with the experimental and theoretical results and suggests that the linked Pdx must undergo complex movements during turnover to accommodate P450cam, which could limit the Pdx-to-P450cam electron transfer reaction.
Optical storage: technology and applications

Summary form only given. Optical-storage technology makes use of laser light for recording digital data on rotating-disk media. It is characterized by the combination of high storage density, high data rate, fast access time, high reliability, and media removability. The author considers optical storage technology and its application. >
Dual Enrollment in a Rural Environment: A Descriptive Quantitative Study.

Dual enrollment is a federally funded program that offers high school students the opportunity to earn both high school and postsecondary credits for the same course. While the phenomenon of concurrent enrollment in postsecondary and college educational programs is not new, political support and public funding has drawn focus to the policies of dual enrollment as an initiative of the No Child Left Behind (NCLB) Federal Act of 2001. This descriptive, quantitative study observed courses taken by dual enrollment students from a program seated in rural western Pennsylvania near the Allegheny foothills. Course registrations for 164 students between spring 2006 through spring 2008 semesters were examined. Implementation of NCLB guidelines for course selection and examples of how such courses have been researched were discussed. Concerns about course selection observed in other states were raised.
The topological properties of magnetic helicity

The relation of magnetic helicity to the topological structure of field lines is discussed. If space is divided into a collection of flux tubes, magnetic helicity arises from internal structure within a flux tube, such as twist and kinking, and external relations between flux tubes, i.e. linking and knotting. The concepts of twist number and writhing number are introduced from the mathematical-biology literature to describe the contributions to helicity from twist about the axis of a flux tube, and from the structure of the axes themselves.There exists no absolute measure of the helicity within a subvolume of space if that subvolume is not bounded by a magnetic surface. However, a topologically meaningful and gauge-invariant relative measure of helicity for such volumes is presented here. The time derivative of this relative measure is calculated, which leads to an expression for the flow of topological structure across boundaries.
Cactis: a self-adaptive, concurrent implementation of an object-oriented database management system

Cactis is an object-oriented, multiuser DBMS developed at the University of Colorado. The system supports functionally-defined data and uses techniques based on attributed graphs to optimize the maintenance of functionally-defined data. The implementation is self-adaptive in that the physical organization and the update algorithms dynamically change in order to reduce disk access. The system is also concurrent. At any given time there are some number of computations that must be performed to bring the database up to date; these computations are scheduled independently and are performed when the expected cost to do so is minimal. The DBMS runs in the Unix/C Sun workstation environment. Cactis is designed to support applications that require rich data modeling capabilities and the ability to specify functionally-defined data, but that also demand good performance. Specifically, Cactis is intended for use in the support of such applications as VLSI and PCB design, and software environments.
Duty to Treat or Right to Refuse

By entering the medical profession, physicians have consented to accept a standard level of risk of infection. In most instances, the risk of contracting HIV does not exceed this level.
Effect of Δ9-tetrahydrocannabinol on hypothalamic thermosensitive units

Abstract Thermosensitive anterior hypothalamic neurons (pre-optic region) were studied in urethane and chloralose anesthetized cats in an attempt to characterize the hypothermic action of Δ 9 -THC at the neuronal level. One hundred and seventy-eight single neurons were isolated and subjected to thermal challenge, 66 were found to reproducibly alter firing frequency at a significant level (thermosensitivity (T.S.) > 0.75). Twenty-one of these units met the criteria for primary thermodetectors, 34 were heat-sensitive interneurons, and 11 were cold-sensitive interneurons. Administration of Δ 9 -THC (1.0–2.0 mg/kg i.v.) decreased the spontaneous firing and increased the T.S. of the primary thermodetector units. Δ 9 -THC also increased the spontaneous firing frequency as well as the T.S. of heat-sensitive interneurons, while decreasing both the T.S. and spontaneous firing of cold-sensitive interneurons. The decreased spontaneous firing of primary thermodetectors could result from altered facilitory or inhibitory influences converging on these cells. The increased thermosensitivity is consistent with the hypothesis that the pre-optic region modulates cannabinoid-induced hypothermia.
Information accessibility reconsidered

Abstract What makes information accessible in an organization? Although the conventional wisdom is that information accessibility is of primary importance in explaining information acquisition and use, the determinants and components of such accessibility are not, as yet, well understood. The present paper explores this question and attempts to break through our conventional conceptions. Information accessibility is appraised not only in terms of its obvious virtues, but in terms of its oft-hidden costs. Such costs are typically borne by the provider of information, whose interest in the exchange is likely to be one of organizational influence. Reflecting the need to influence, information will be accessible in an organization in large part because of information-push, not simply in response to information-pull. New digital computer and communications technologies tend to intensify the process, raising the information waters in the organization. Coping with the new information surfeit places a premium on organizational intelligence and good sense making.
Effect of cobalt on microsomal cytochrome P-450: differences between liver and intestinal mucosa.

Summary Parenteral administration of cobalt to rats stimulated hepatic microsomal heme oxygenase (MHO) activity, depressed cytochrome P-450 content and reduced benzpyrene hydroxylase (BPH) activity, confirming previous reports. By contrast, in the intestinal mucosa, cobalt treatment not only stimulated MHO but in addition increased both cytochrome P-450 and BPH. This differential effect between liver and intestine suggests that the mechanism of the cobalt-mediated stimulation of MHO in the two tissues either differs and/or is unrelated to the turnover of cytochrome P-450.
Toward a synthesis of cognitive biases: How noisy information processing can bias human decision making.

A single coherent framework is proposed to synthesize long-standing research on 8 seemingly unrelated cognitive decision-making biases. During the past 6 decades, hundreds of empirical studies have resulted in a variety of rules of thumb that specify how humans systematically deviate from what is normatively expected from their decisions. Several complementary generative mechanisms have been proposed to explain those cognitive biases. Here it is suggested that (at least) 8 of these empirically detected decision-making biases can be produced by simply assuming noisy deviations in the memory-based information processes that convert objective evidence (observations) into subjective estimates (decisions). An integrative framework is presented to show how similar noise-based mechanisms can lead to conservatism, the Bayesian likelihood bias, illusory correlations, biased self-other placement, subadditivity, exaggerated expectation, the confidence bias, and the hard-easy effect. Analytical tools from information theory are used to explore the nature and limitations that characterize such information processes for binary and multiary decision-making exercises. The ensuing synthesis offers formal mathematical definitions of the biases and their underlying generative mechanism, which permits a consolidated analysis of how they are related. This synthesis contributes to the larger goal of creating a coherent picture that explains the relations among the myriad of seemingly unrelated biases and their potential psychological generative mechanisms. Limitations and research questions are discussed.
Rare Copy Number Variation in Treatment-Resistant Major Depressive Disorder

Background While antidepressant treatment response appears to be partially heritable, no consistent genetic associations have been identified. Large, rare copy number variants (CNVs) play a role in other neuropsychiatric diseases, so we assessed their association with treatment-resistant depression (TRD). Methods We analyzed data from two genome-wide association studies comprising 1263 Caucasian patients with major depressive disorder. One was drawn from a large health system by applying natural language processing to electronic health records (i2b2 cohort). The second consisted of a multicenter study of sequential antidepressant treatments, Sequenced Treatment Alternatives to Relieve Depression. The Birdsuite package was used to identify rare deletions and duplications. Individuals without symptomatic remission, despite two antidepressant treatment trials, were contrasted with those who remitted with a first treatment trial. Results CNV data were derived for 778 subjects in the i2b2 cohort, including 300 subjects (37%) with TRD, and 485 subjects in Sequenced Treatment Alternatives to Relieve Depression cohort, including 152 (31%) with TRD. CNV burden analyses identified modest enrichment of duplications in cases (empirical p = .04 for duplications of 100–200 kilobase) and a particular deletion region spanning gene PABPC4L (empirical p = .02, 6 cases: 0 controls). Pathway analysis suggested enrichment of CNVs intersecting genes regulating actin cytoskeleton. However, none of these associations survived genome-wide correction. Conclusions Contribution of rare CNVs to TRD appears to be modest, individually or in aggregate. The electronic health record-based methodology demonstrated here should facilitate collection of larger TRD cohorts necessary to further characterize these effects.
Corrected QT interval changes with atypical antipsychotics.

n this issue of the Journal, the meta-regression analyses by Jensen et al. aim to quantify the effects of antipsychotic I drugs on cardiac QT prolongation in the setting of pediatric randomized or open clinical trials. The common prescription of atypical antipsychotic medication, the known metabolic burden of these agents, and the theoretical potential for related cardiovascular compromise have prompted significant clinical and public concerns regarding the safety of their use in children and adolescents. Of particular concern to prescribing clinicians is the potential effect that antipsychotic drugs have on prolonging the cardiac QT interval, which in turn is associated with torsade de pointes, a rare but potentially fatal cardiac arrhythmia. Repolarization reserve is a term used to describe the existence in normal ventricles and conducting systems of protective redundancy in the components of cardiac repolarization. Congenital (e.g., long QT syndrome) and acquired (e.g., atypical antipsychotic drugs) factors can affect and lessen a given patient’s repolarization reserve, resulting in QT prolongation. Additional acquired factors include overdose, medical conditions that result in hypokalemia, and concomitant therapy with agents that lengthen the QT interval. Risk of serious arrhythmias has been related to the heart rate-corrected QT (QTc) interval, with 480 ms a relatively accepted upper safety limit for most medications and longer than 500 ms a critical value. Lack of marked QTc prolongation alone does not preclude serious arrhythmias. The meta-analysis involved 5,423 medically screened, healthy participants with a mean age of 12.8 years. Participants were primarily boys treated for disruptive behavioral, psychotic, and bipolar spectrum disorders, with an average medication exposure of 16 weeks. Most patients were treated with risperidone (n 1⁄4 2,234; mean dose 2.1 mg/day) and aripiprazole (n 1⁄4 814; mean dose 14.0 mg/day). Restingstate electrocardiograms in the context of clinical trial participation provided the basis for the QT data, with only 4 studies explicitly examining cardiac conduction. Most studies did not report specific methods for correcting the QT interval according to heart rate. In this analysis, 1% to 3% of the sample developed a QTc interval longer than 440 to 470 ms during the course of antipsychotic treatment, whereas only 1 patient (on ziprasidone) had a QTc interval longer than 500 ms. Although the mean increase in QTc interval for the entire sample was modest at 1 to 2 ms, the mean increase for ziprasidone alone was 8.74 ms (CI þ5.19 to þ12.30 ms), which was significant compared with placebo. Of the antipsychotic drugs examined, only risperidone (þ1.68 ms) and ziprasidone were associated with a QTc change significantly different than 0.
Molecular dynamics simulations of the effects of ring-saturated thymine lesions on DNA structure.

The effect of thymine lesions produced by radiation or oxidative damage on DNA structure was studied by molecular dynamics simulations of native and damaged DNA. Thymine in position 7 of native dodecamer d(CGCGAATTCGCG)2 was replaced by one of the four thymine lesions 5-hydroxy-5,6-dihydrothymine, 6-hydroxy-5,6-dihydrothymine (thymine photohydrate), 5,6-dihydmxy-5,6-dihydro-thymine (thymine glycol), and 5,6-dihydmthymine. Simulations were performed with Assisted Model Building with Energy Refinement force field. Solvent was represented by a rectangular box of water with periodic boundary conditions applied. A constant temperature and constant volume protocol was used, the observed level of distortions of DNA structure depends on the specific nature of the lesion. The 5,6-dihydrothymine does not cause distinguishable perturbations to DNA. Other lesions produce a dramatic increase in the rise parameter between the lesion and the 5′ adjacent adenine. These changes are accompanied by weakening of Watson–Crick hydrogen bonds in the A6-T19 base pair on the 5′ side of the lesion. The lesioned bases also show negative values of inclination relative to the helical axis. No changes in the pattern of backbone torsional angles are observed with any of the lesions incorporated into DNA. The structural distortions in DNA correlate well with known biological effects of 5,6-dihydrothymine and thymine glycol on such processes as polymerase action or recognition by repair enzymes. © 1995 John Wiley & Sons, Inc.
Kinase Control of Latent HIV-1 Infection: PIM-1 Kinase as a Major Contributor to HIV-1 Reactivation

Despite the clinical relevance of latent HIV-1 infection as a block to HIV-1 eradication, the molecular biology of HIV-1 latency remains incompletely understood. We recently demonstrated the presence of a gatekeeper kinase function that controls latent HIV-1 infection. Using kinase array analysis, we here expand on this finding and demonstrate that the kinase activity profile of latently HIV-1-infected T cells is altered relative to that of uninfected T cells. A ranking of altered kinases generated from these kinome profile data predicted PIM-1 kinase as a key switch involved in HIV-1 latency control. Using genetic and pharmacologic perturbation strategies, we demonstrate that PIM-1 activity is indeed required for HIV-1 reactivation in T cell lines and primary CD4 T cells. The presented results thus confirm that kinases are key contributors to HIV-1 latency control. In addition, through mutational studies we link the inhibitory effect of PIM-1 inhibitor IV (PIMi IV) on HIV-1 reactivation to an AP-1 motif in the CD28-responsive element of the HIV-1 long terminal repeat (LTR). The results expand our conceptual understanding of the dynamic interactions of the host cell and the latent HIV-1 integration event and position kinome profiling as a research tool to reveal novel molecular mechanisms that can eventually be targeted to therapeutically trigger HIV-1 reactivation.
Pharmacological modification of the Ca2+-pump ATPase activity of human erythrocytes.

Summary The Ca2+-pump ATPase of human RBC membranes appears to be exquisitely sensitive to a variety of amphipathic molecules. The acidic protein calmodulin (CaM) activates the enzyme some three- to fivefold with an apparent Kd of approximately 1–5 nM. A variety of other amphipathic anions, such as acidic phospholipids, free fatty acids, and anionic detergents, are less potent and in some cases less efficacious than CaM, but also activate the enzyme. Similar results have been observed for other CaM-dependent enzymes, and it is suggested that these agents mimic CaM in a general, but rather nonspecific, fashion. Activation of the human RBC Ca2+-pump ATPase by CaM or other amphipathic anions can be selectively antagonized by a wide variety (structurally and pharmacologically) of amphipathic cations. There is no simple relationship between antagonism of CaM in vitro and the general systemic pharmacology of these drugs. The only common feature of such drugs is that they are amphipathic cations. Neutral molecules such as saponin exerted neither CaM-like activity nor CaM antagonism. Great caution is urged in the inferential use of presumed anti-CaM drugs to study biological systems.
Analysis of Resource Allocation in Final Stage Sugarcane Clonal Selection

Superior genotypes of sugarcane (interspecific hybrids of Saccharum spp.) must continue to be developed with current resources as selection criteria evolve and expand. Developing future cultivars of sugarcane for the Everglades Agricultural Area (EAA) of South Florida with high water table tolerance and increased P-uptake efficiency could be an integral part of Everglades restoration. The objective of this study was to assess the current allocation of resources in the final selection phase of cultivar (clonal) development of the Canal Point, FL, sugarcane breeding program. Variance component analyses were conducted on elite genotypes from 7 yr of trials. Variance components were used to compare relative magnitudes of sources of variation and to explore more efficient use of resources. Variation attributable to crop x location interaction was nearly always the largest relative source of variation next to the residual term. The contributions to variance due to genotype × crop and genotype x location interactions were low, though these interactions cannot be discounted in cultivar release decisions. Variance due to replications was extremely low. Four statistics were used as metrics of experimental precision when reducing the number of replications. Reducing replications from eight to four did not compromise experimental precision. Removing the second-year planting sequence compromised little, if any, useful information for effective cultivar release decisions. Better allocation of resources could be achieved by alternative experimental design scenarios. Testing for high water table tolerance or P-uptake efficiency could also be included, improving ecological compatibility of agriculture in the EAA.
A technique for phase speed measurements in turbulent flow

A technique is described for measuring the local phase speed in a turbulent flow. The technique has been used to measure the phase speed of the Fourier components of the longitudinal velocity fluctuations in grid turbulence. These measurements are unique in that the probe spacing is only twice the Kolmogoroff length scale. The velocity fluctuations were measured with linearized constant-temperature hot-wire anemometers, the outputs of which were digitally sampled and recorded in real time. Digital Fourier analysis techniques were then used to calculate the cross-spectral density of the two velocity measurements. From this, the phase, phase speed, and coherence were calculated. The coherence has been used to estimate the variance of these measurements.
The effects of different types of acidosis and extracellular calcium on the mechanical activity of turtle atria

The effects of acidosis and extracellular calcium were examined at 20°C in the isolated spontaneously contracting atria of the freshwater turtle (Chrysemys picta bellii). The atria were subjected to treatments of lactic acidosis, hypercapnic acidosis or chloride acidosis in the presence of both normal (2.0 mM) and high (10.0 mM) calcium, which simulated levels of acidosis and calcium observed in vivo. In all cases of acidosis, pH was reduced to 6.80 from a control pH of 7.80.
Transforming projectile system

The objective of this research was to develop a framework to design a transforming projectile system that has the ability to convert from a simple projectile into a guided projectile that can perform multiple tasks depending on its payload and guiding keyboard. This projectile would be launched from existing standard platforms. Our objective is to determine which design alternative potentially provides the greatest value relative to cost. The end result will be a tool kit that can be used to model transforming projectile alternatives. With this tool, we will be able to assess multiple alternatives and determine which best suites stakeholders' needs, foremost being the soldier.
Men, Militarism & UN Peacekeeping: A Gendered Analysis

Men, Militarism & UN Peacekeeping: A Gendered Analysis. By Sandra Whitworth. Boulder and London: Lynne Rienner. 2004. 225 pp. $49.95.Armed conflict, torture, murder, sexual assault, sexual enslavement, human trafficking and HIV/AIDS—United Nations peacekeepers are sent into conflict-torn countries to help prevent the further spread of these horrors. UN Secretary-General Kofi Annan often highlights these brutalities when he publicly calls upon member states to send troops and resources to protect and assist vulnerable populations in conflict zones. In her most recent book, Men, Militarism & UN Peacekeeping, Sandra Whitworth provides a critical feminist analysis of a UN peacekeeping system that not only is failing to protect civilian populations but is also implicated in the spread of HIV/AIDS and in the torture, murder, sexual assault and enslavement, and human trafficking of the very populations the mission was purportedly sent to assist. Throughout, Whitworth uses sharp critical feminist analyses to help us understand why UN peacekeeping missions have too often become sites of violence and abuse.
Malignant juxtadrenal schwannoma.

Abstract We believe we report the first case of malignant juxtadrenalschwannoma. This rare tumor was discovered incidentally in a patient who presented with fever, mental confusion, weight loss, leukocytosis, and elevated erythrocyte sedimentation rate. Preoperative radiographic and endocrine evaluations were suggestive of a nonfunctioning adrenal tumor. Its suprarenal location was unequivocally demonstrated by CT scan, sonography, angiography, and magnetic resonance imaging studies. Angiography revealed that the tumor derived its blood supply from the adrenal and renal vessels. The final diagnosis and its juxtadrenal origin was confirmed by histologic and immunohistochemical studies. A review of the literature on retroperitoneal schwannoma is included.
Lu-hf total-rock isochron for the eucrite meteorites

The isotope Lu-176 (2.6% of natural lutetium) decays by beta(-) to Hf-176, with a long half life. The first Lu-Hf isochron is presented. The eucrite meteorites, a suite of planetary igneous rocks of known age, 4,550 Myr, define a 10-point total-rock isochron with a slope of 0.0934 + or - 40, leading to a value of 3.53 + or - 0.14 x 10 to the 10th yr for the beta(-) decay half life of Lu-176. The isochron intercept of 0.27973 + or - 12 gives the initial Hf-176/Hf-177 for the inner solar system at the time of accretion.
Trends and Controversies

This issue includes two articles with additional research examples from distinguished experts in social science and computer science. In the first article, "Secondary Avatars and Semiautonomous Agents" presents semiautonomous agent assistants that have been incorporated into recent MMOGs. In the second article, a group of people constructed combat, mentoring, and trust networks based on data from Sony's popular MMOG Everquest II. They also provide an excellent summary of their ongoing research in performance and learning, player churn analysis, and identifying undesirable behavior in MMOGs. The authors argue that the close collaboration between social scientists and computer scientists is creating an emerging area called "computational social science," where computation is used as an integral mechanism in social science research.
Effect of the displacement current on the alternating current admittance of a double injection diode

Abstract The effect of the displacement current on the a.c. admittance of a double injection diode in the ohmic relaxation regime is evaluated and it is shown that at high frequencies this admittance can be represented by the device capacitance C and the conductance4/3 ( J 0 /V a ) in parallel.
Response rate and varied reinforcement: Reinforcers of different strengths

Twelve rats were trained to lever press on a multiple schedule with the delivery of pellets, sucrose, or pellets or sucrose correlated with the three legs of the schedule. The “pellet-or-sucrose” condition, i.e., varied reinforcement, produced the highest response rates. These results replicate, in a within-Ss design, the previous findings of a between-group experiment.
Modeling risk of gastrointestinal events among Medicaid NSAID users using propensity scores.

The purpose of the study is to evaluate the gastrointestinal risk of nonsteroidal anti-inflammatory drugs compared with cyclooxygenase-2 inhibitors in a Medicaid managed care population. Medical and prescription claims were analyzed for all Medicaid-enrollees aged 18 years and older, who received a cyclooxygenase-2 or other prescription nonsteroidal anti-inflammatory drug between January 6, 2000 and January 6, 2002, and who did not use these drugs for at least 6 months prior. A logistic model was developed of the propensity for either treatment and stratified patients by quintiles of their propensity score, adjusting for demographics, indications for nonsteroidal anti-inflammatory drugs and gastrointestinal risks. The rates of gastrointestinal event (ICD-9 codes 531–534,578) among nonsteroidal anti-inflammatory drug and cyclooxygenase-2 users were compared. The model was adjusted for drug exposure which was calculated using the medication possession ratio. Of the total sample, 73% were female, 43% were Ca...
What is the “Cognitive” in Cognitive Neuroscience?

This paper argues that the cognitive neuroscientific use of ordinary mental terms to report research results and draw implications can contribute to public confusion and misunderstanding regarding neuroscience results. This concern is raised at a time when cognitive neuroscientists are increasingly required by funding agencies to link their research to specific results of public benefit, and when neuroethicists have called for greater attention to public communication of neuroscience. The paper identifies an ethical dimension to the problem and presses for greater sensitivity and responsibility among neuroscientists regarding their use of such terms.
Observations of Shear Localization in Liquid Lubricants Under Pressure

A High Pressure Flow Visualization Cell has been designed and constructed to perform a fundamental investigation of the deformation behavior of liquid lubricants under lubricated concentrated contact conditions. A pressure of 0.3 GPa and a shear stress between parallel plates of about 25 MPa has been demonstrated. Time averaged velocity profiles show no continuous slip either in the bulk or at walls. Localized slip at shear bands inclined to the walls was demonstrated to occur during nonlinear shear response. The number of shear bands increases with shear rate (and shear stress) from as few as one at the onset of non-Newtonian flow until the shear region is essentially filled with bands with a spatial periodicity of 7 μm
Sinus Node Dysfunction in Atrial Fibrillation: Cause or Effect?

Atrial fibrillation (AF) and sick sinus syndrome (SSS) are two conditions that frequently coexist. Despite a wealth of available knowledge, the link between these two entities is poorly understood. Whether AF is a harbinger of SSS or whether SSS predisposes to AF has been the subject of much debate. AF results in sinus node remodeling on a cellular and molecular basis that may promote SSS. However, not all patients with atrial fibrillation have SSS. Though “AF begets AF”, AF may also beget SSS; and SSS may also beget AF. Multiple studies have demonstrated that sinus node dysfunction may precede the onset of AF. This review will focus on alterations to sinus node structure and function, overdrive suppression, ion channel remodeling, and transient myocardial ischemia as possible mechanisms associated with AF induced SSS. In addition, we will review evidence suggesting that SSS, characterized by a combination of atrial extrasystoles, dispersion of excitability recovery and sinus node ischemia, may lead to AF. Additional factors common to both conditions such as aging and interstitial atrial fibrosis, may explain their coexistence. All this raises many therapeutic challenges associated with the interplay of AF and SSS.
Nematode Tracks in the Study of Movement of Meloidogyne Incognita Incognita 1)

Tracks of the plant-parasitic nematode, Meloidogyne incognita incognita, were obtained on a nutrient 2% agar medium from which free surface water had been allowed to evaporate. Under the experimental conditions used there was no apparent polarity of the tracks toward actively growing tomato roots or seedlings. The larvae apparently made contact with the roots by random and constant movement. Larvae moving forward were unaffected by their own or other nematode tracks; in moving backward for short distances they followed the original tracks made when moving forward. The track of an adult male was also obtained.
Risk stratification in patients with remote prior myocardial infarction using rest-stress myocardial perfusion SPECT: prognostic value and impact on referral to early catheterization.

Background. Little is known about the prognostic value of myocardial perfusion single photon emission computed tomography (SPECT) in patients with remote prior myocardial infarction (MI). Methods and Results. We identified 1413 consecutive patients with remote prior MI who underwent rest-stress myocardial perfusion SPECT. Semiquantitative visual analysis of 20 SPECT segments was used to define the summed stress, rest, and difference scores. The number of non-reversible segments was used as an index of infarct size. During follow-up (≥1 year), 118 hard events occurred: 64 cardiac deaths (CDs) and 54 recurrent MIs. Annual CD and hard event rates increased significantly as a function of SPECT abnormality. For summed stress scores less than 4, 4 to 8, 9 to 13, and more than 13, the annual CD rates were 0.4%, 0.9%, 1.7%, and 3.5%, respectively (P = .002). Patients with small MI (<4 non-reversible segments) and no or mild ischemia (summed difference score ≤6) had an annual CD rate of 0.6%. Patients with small MI and moderate or severe ischemia had an annual CD rate of 1.6%, and those with large MI (≥4 non-reversible segments) had moderate to high annual CD rates (3.7%-6.6%) regardless of the extent of ischemia. Nuclear testing added incremental prognostic information to pre-scan information. Compared with a strategy in which all patients are referred to catheterization, a strategy that referred only those patients with a risk for CD of greater than 1% by myocardial perfusion SPECT resulted in a 41.6% cost savings. Conclusions. Myocardial perfusion SPECT adds incremental value to pre-scan information and is highly predictive and cost-efficient in the risk stratification of patients with remote prior MI. Patients with normal or mildly abnormal scan results or small MI in combination with absent or mild ischemia have a low risk for CD. (J Nucl Cardiol 2002;9:23-32.)