cssi/SciSciGPT-SciSciNet huggingface dataset:
Understanding and Optimizing Group Dynamics in Case-Based Collaborative Learning

Teamwork skills are recognized as a core competency of physicians. To more effectively prepare trainees for the demands of their future work, medical educators are increasingly turning to group-based instructional formats. We employ case-based collaborative learning (CBCL) — a format which requires daily in-class discussion and collaboration in assigned small groups. While students overwhelmingly embraced CBCL as stimulating and thought-provoking, some students reported that social dynamics among group members adversely impacted their experience. Using mixed methods, we demonstrate that a short intervention that asked students to discuss how they can best learn together improved small group dynamics, and promoted psychological safety among peers. Importantly, no specific instruction in team work was required, students overall had a clear understanding how they could improve, but they did not know how to start this conversation with each other. To promote team learning, we propose that educators emphasize students’ accountability to their peers’ learning in addition to their own, and devote some time in class for teams to reflect and discuss how to improve learning with each other. Our observations are of interest to anyone frequently relying on group work without peer assessment or formal feedback on group performance.
Response to Diamant's “Conflict and Conflict Resolution in China”

In his colorful article "Conflict and Conflict Resolution in China: Beyond Mediation-Centered Approaches," Neil Diamant emphasizes that mediation is but one of several conflict resolution methods in China. Furthermore, he notes that there are differences among the Chinese about the preferred method of conflict resolution. Focusing principally on marriage disputes, Diamant interviewed various judges, mediators, and bureaucrats who were responsible for handling marital disputes in urban and rural areas of China. He also examined newspapers and archives in both areas. His first conclusion is that many disputants do not take their conflicts to mediation because the mediators lack legitimacy. The mediators, it is reported, are occasionally impatient, act blindly, wish to receive personal credit, seek status, and are petty and out of touch with the younger generation. When they do seek mediation, some disputants fail to receive this service. Some mediators, we are told, do not mediate because they lack confidence, are afraid of the hassle, or are incapable of handling marriage problems. Others are reluctant to mediate for fear of making enemies of one side or neglect mediation and kick the cases into the courts because they are not paid for their mediation services. Finally, some do not mediate extensively because they are overburdened. Diamant contends that class and gender are the principal factors responsible for the differences in conflict resolution preferences of the Chinese. With regard to class, he notes that peasants and workers make heavier use of the courts than do the more educated or elite. The latter groups tend to keep their problems to themselves or agree to some nonconfrontational methods of conflict resolution. Nobody seems to use mediation.
Telomeres and Transposable Elements

This chapter describes what is known about the two telomere-specific retrotransposons, HeT-A and TART. Although Drosophila is the only organism in which the telomerase-telomere is known to be completely replaced by retrotransposons, there are now a few examples of other retrotransposons that associate specifically with telomerase-telomeres. These telomere-associated retrotransposons are also discussed. Phylogenetic analysis of the reverse transcriptase (RT) and endonuclease domains of TART places it in the Jockey clade of arthropod non-LTR elements. In summary, studies of TART argue that HeT-A and TART are converging on their telomere specialization, rather than diverging from a common ancestor. Their primary shared characters are the gag coding sequence and the telomere targeting. This suggests that the gag protein may have a role in delivering the elements to chromosome ends, a hypothesis that is being actively investigated. Although Drosophila is the only organism known to have retrotransposon-telomeres instead of telomerase-telomeres, retrotransposons with a special relationship to telomerase-telomeres have been described for several organisms. Elements transposing as DNA have not been reported in terminal sequences, although DNA transposons are found in subtelomeric satellite regions. The amplified telomere sequences solve the problem of chromosome shortening. In most organisms, the length of telomeric arrays is much greater than needed to replace end erosion, and these sequences seem to have additional roles. The evidence suggesting relationships between telomeres and cell life span, tumorigenesis, and cell cycle checkpoints hints that these roles are important.
Newly Developed Time-Resolved EPR Techniques for the Study of Cytochrome C Oxidase

We present recent results from two new time-resolved EPR techniques used to probe structure and function of cytochrome c oxidase. The first of these, which we have used at cryogenic temperatures, is pulse field-sweep EPR. With this we can resolve hyperfine couplings of the CuA nucleus in cytochrome Oxidase, where such couplings are not directly resolved by straight EPR. This method is a technically simpler alternative to other double resonance techniques. The second technique is an ambient temperature technique to follow oxygen consumption by cytochrome oxidase. This technique uses an oxygen-sensitive spin probe to report the concentration of oxygen in solution. It is feasible to use this spin probe technique together with stopped flow. O2 kinetics have been followed both under aerobic conditions where O2 consumption is limited by cytochrome c reductant and under conditions where low oxygen concentration limits the rate of oxygen consumption.
Nucleotide sequence, transcriptional analysis, and expression of genes encoded within the form I CO2 fixation operon of Rhodobacter sphaeroides

In Rhodobacter sphaeroides, many of the structural genes encoding enzymes of the Calvin cycle are duplicated and grouped within two separate clusters. In this study, the nucleotide sequence of a 5627-base pair region of DNA that contains the form I Calvin cycle gene cluster has been determined. The five open reading frames are arranged in the order, fbpA prkA cfxA rbcL rbcS and are tightly linked and oriented in the same direction. The results of insertional mutagenesis studies suggest the genes are organized within an operon. Consistent with this proposal, the cfxA gene has been tentatively identified as a gene encoding the Calvin cycle enzyme, aldolase. Measurement of the activities of various Calvin cycle enzymes in the insertion mutants showed that inactivation of genes within one CO2 fixation cluster affected expression of genes within the second cluster, revealing a complex regulatory network.
Categories, Functors, and Natural Transformations

First we describe categories directly by means of axioms, without using any set theory, and calling them “metacategories”. Actually, we begin with a simpler notion, a (meta)graph.
Experimental Implementation of Sliding Controls on Automotive Engines

Previous research has shown that high performance engine controllers could be used in conjunction with electronic controls on automatic transmissions to improve shift quality. Due to the highly nonlinear nature of automotive engines and the need for robustness of the design, sliding control is a likely choice. However, a standard sliding derivation for an automotive engine results in an unpractical control law. Robustness is a major consideration especially in the harsh environment of an automobile. In our case, adaptive laws are derived for two slowly varying parameters. The derived adaptive multi-surface control laws are implemented on a microprocessor controlled automotive engine.
Effect of Copper Status on the Urinary Excretion of Tryptophan Metabolites and Amino Acids by the Rat

The effect of dietary copper on selected metabolic systems requiring pyridoxal phosphate was investigated by comparing certain urinary excretory products of pair-fed copper-deficient and copper-adequate rats. Kynurenic acid and xanthurenic acid, two tryptophan metabolites, were in lower concentrations in the urines of the copper-deficient animals in the pretryptophan-load period. Following a tryptophan load, these metabolites increased markedly in the urines of both groups, but the in crements were much larger for the copper-deficient animals. The increases in kynurenic acid were greater than those of xanthurenic acid in both groups, but the increase was disproportionately higher in the copper-deficient rats. The excretion of taurine and urea by the copper-deficient rats was significantly less. At the dilution used, several amino acids were found in significant amounts in the urines of the copper-deficient animals, whereas only taurine was detected in the urines of those fed copper. Several possible explanations of these findings are discussed. J. Nutr. 103: 1764-1771, 1973. INDEXING KEYWORDS urinary amino acids â€¢ure copper deficiency â€¢urinary tryptophan metabolites
Molecular cloning of a gene encoding a 45,000-dalton polypeptide associated with bile acid 7-dehydroxylation in Eubacterium sp. strain VPI 12708.

Eubacterium sp. strain VPI 12708 is an intestinal anaerobic bacterium which possesses an inducible bile acid 7-dehydroxylation activity. Two cholic acid-induced polypeptides with apparent molecular weights of 27,000 and 45,000, respectively, coeluted with bile acid 7-dehydroxylation activity upon anaerobic high-performance gel filtration chromatography of crude cellular protein extracts. The 45,000-dalton polypeptide was purified to greater than 95% homogeneity by high-performance liquid chromatography gel filtration and high-performance liquid-DEAE chromatography. The first 28 amino acid residues of the N terminus of this polypeptide were determined by gas-phase sequencing, and a corresponding mixed oligonucleotide (20-mer) was synthesized. Southern blot analysis of EcoRI total digests of chromosomal DNA showed a 2.6-kilobase fragment which hybridized to the 32P-labeled 20-mer. This fragment was enriched for by size fractionation of an EcoRI total digest of genomic DNA and ligated into bacteriophage lambda gt11. Recombinant phage containing the putative gene encoding the 45,000-dalton polypeptide were detected with the 32P-labeled 20-mer by plaque hybridization techniques. The insert was 2.6 kilobases in length and may contain the entire coding sequence for the 45,000-dalton polypeptide. The 2.6-kilobase insert was subcloned into pUC8 and transformed into Escherichia coli DH5 alpha. However, the 45,000-dalton polypeptide was not detected in cell extracts of this organism when specific antibody was used. Preliminary nucleic acid sequence data correlated exactly with the amino acid sequence. A cholic acid-induced mRNA species of greater than 6 kilobases in size was identified by Northern (RNA) blot analysis of total RNA, suggesting that the gene coding for this polypeptide is part of a larger operon. Images
Modeling Fine Grain Computation via the Fusion of Two Extended Petri Nets

We describe an. automated modeling system which uses extended Petri nets to model dataflow programs executing on a dataflow architecture. We independently model both a dataflow algorithm and a dataflow architecture, and describe how these two models are fused. The fused model allows the parallel programmer to maintain a logical connectivity between the dataflow graph and its execution on the machine. The fused net is executed by our software to generate statistics which enable parallel programmers to efficiently map algorithms onto parallel architectures.
The Work-Product Doctrine as a Means toward a Judicially Enforceable Duty of Confidentiality in International Commercial Arbitration

The private nature and presumptively confidential character of international commercial arbitration proceedings are two of its most attractive features. At the same time, the assumption that the confidentiality feature of arbitration provides a broader level of protection from disclosure when compared to public court proceedings can no longer be supported without qualification. In fact, a growing number of courts around the world seem to agree that disclosure of documents and materials produced during arbitration may be compelled regardless of any express confidentiality agreement entered into between the parties. It is argued in this article that by raising the burden of proof for disclosure of information and materials produced during arbitration, a fair balance may be struck between the essential private nature of arbitration proceedings and the duty of confidentiality. It is suggested that the U.S. work-product doctrine may function as a starting point for an international consensus on how to best and more predictably protect confidentiality in arbitration. The balancing approach of the work-product doctrine, including the standard of substantial need and undue hardship, is a well established principle in U.S. law and may aid in defining uniform limits for otherwise undefined or very broadly defined exceptions to confidentiality in international commercial arbitration.
Understanding the lingering consequences of what we treat and what we do

Granja and colleagues have helped us by showing that long-term follow-up is feasible and by trying to tease out whether select intensive care unit patient populations are at particular risk of adverse outcomes. This work gives us clues for future investigations which will hopefully interrogate further the potential mechanisms of action that underlie poor long-term outcomes. In the meantime, we can hope that this quality of follow-up will move from the research arena to become a part of routine clinical care.
Rational Analysis of Tension-Field Beams

The analysis in this paper is not based upon Wagner's fundamental assumption that the force in each flange of a tension-field beam is in the direction of the flange. The wing is considered as a whole, and the stresses in the tension-field shear web are determined by a method similar to that for finding the longitudinal shear stresses in a beam with a shear-resistant web. Approximate formulas are then developed which can be applied to beams of either constant or variable cross section.
Enhancing the efficacy of cisplatin in ovarian cancer treatment – could arsenic have a role

Ovarian cancer affects more than 200,000 women each year around the world. Most women are not diagnosed until the disease has already metastasized from the ovaries with a resultant poor prognosis. Ovarian cancer is associated with an overall 5 year survival of little more than 50%. The mainstay of front-line therapy is cytoreductive surgery followed by chemotherapy. Traditionally, this has been by the intravenous route only but there is more interest in the delivery of intraperitoneal chemotherapy utilizing the pharmaco-therapeutic advantage of the peritoneal barrier. Despite three large, randomized clinical trials comparing intravenous with intraperitoneal chemotherapy showing improved outcomes for those receiving at least part of their chemotherapy by the intraperitoneal route. Cisplatin has been the most active drug for the treatment of ovarian cancer for the last 4 decades and the prognosis for women with ovarian cancer can be defined by the tumor response to cisplatin. Those whose tumors are innately platinum-resistant at the time of initial treatment have a very poor prognosis. Although the majority of patients with ovarian cancer respond to front-line platinum combination chemotherapy the majority will develop disease that becomes resistant to cisplatin and will ultimately succumb to the disease. Improving the efficacy of cisplatin could have a major impact in the fight against this disease. Arsenite is an exciting agent that not only has inherent single-agent tumoricidal activity against ovarian cancer cell lines but also multiple biochemical interactions that may enhance the cytotoxicity of cisplatin including inhibition of deoxyribose nucleic acid (DNA) repair. In vitro studies suggest that arsenite may enhance the activity of cisplatin in other cell types. Arsenic trioxide is already used clinically to treat acute promyelocytic leukemia demonstrating its safety profile. Further research in ovarian cancer is warranted to define its possible role in this disease.
Studies on the Effects of Hydroxyurea and Other Anticancer Drugs upon Pyrimidine Metabolism

Summary The reversal of azauridine-induced oroticaciduria by hydroxyurea has been studied to further elucidate the control mechanisms involved in the de novo pathways of pyrimidine biosynthesis. No direct effect of hydroxyurea upon partially purified aspartate transcarbamylase and dihydroorotase was observed. Hydroxyurea selectively inhibited the incorporation of 14C-labeled aspartate, orotate, and formate into the DNA bases of human leukemic cells incubated in vitro. No effect of hydroxyurea was observed in the RNA bases isolated from these leukemic cells. Other chemotherapeutic agents, including 5-iododeoxyuridine, 5-fluorodeoxyuridine, Methotrexate, cytosine arabinoside, and cyclophosphamide, were administered to patients receiving 6-azauridine. Only Methotrexate and cyclophosphamide inhibited orotic acid excretion in a manner similar to hydroxyurea. These results suggest that the control of pyrimidine biosynthesis is linked to DNA synthesis or function in an as yet unexplained manner.
Neuroendocrine pharmacology of three serotonin releasers: 1-(1,3-benzodioxol-5-yl)-2-(methylamino)butane (MBDB), 5-methoxy-6-methyl-2-aminoindan (MMAi) and p-methylthioamphetamine (MTA).

Serotonin (5-hydroxytryptamine, 5-HT)-releasing drugs are important experimental tools to examine the role of serotonergic nerve terminals in the secretion of hormones. The drugs 1-(1,3-benzodioxol-5-yl)-2-(methylamino)butane (MBDB), 5-methoxy-6-methyl-2-aminoindan (MMAI) and p-methylthioamphetamine (MTA) have been suggested to be 5-HT releasers. The present study characterized MBDB, MMAI and MTA by using their effects on the secretion of the hormones adrenal corticotrophin (ACTH), corticosterone, prolactin, oxytocin and renin. The time course of the effect of MBDB, MMAI and MTA (5 mg/kg, i.p.) showed that the peak effect on plasma ACTH occurred 10 min after the injection, whereas the prolactin response did not reach a maximum until 30 min after injection. MBDB increased plasma renin concentration within 10 min, whereas the effect of MTA was significant only at 30 min after injection. All three 5-HT releasers decreased HR (within 5 min) and blood pressure (at 15 min after injection). MBDB, MMAI and MTA increased plasma ACTH, corticosterone, prolactin and renin levels in a dose-dependent manner, whereas no changes were observed in plasma vasopressin concentrations. MTA and MMAI, but not MBDB, significantly increased plasma oxytocin concentrations in a dose-dependent manner. Pretreatment of rats with fluoxetine blocked the ACTH response to MBDB and MMAI, but not to MTA. The prolactin response to all three 5-HT releasers was blocked by fluoxetine. The oxytocin response to MTA and MMAI was inhibited by fluoxetine. The renin responses to all three 5-HT releasers were not significantly inhibited by fluoxetine. The results suggest that MBDB, MMAI and MTA can increase the secretion of several hormones, at least in part, through stimulation of serotonergic neurotransmission. However, these three 5-HT releasers seem to have effects on other (and as yet uncharacterized) mechanisms that can stimulate the secretion of some hormones.
Transcriptional and Chromatin Regulation during Fasting – The Genomic Era

An elaborate metabolic response to fasting is orchestrated by the liver and is heavily reliant on transcriptional regulation. In response to hormones (glucagon, glucocorticoids) many transcription factors (TFs) are activated and regulate various genes involved in metabolic pathways aimed at restoring homeostasis: gluconeogenesis, fatty acid oxidation, ketogenesis, and amino acid shuttling. We summarize recent discoveries regarding fasting-related TFs with an emphasis on genome-wide binding patterns. Collectively, the findings we discuss reveal a large degree of cooperation between TFs during fasting that occurs at motif-rich DNA sites bound by a combination of TFs. These new findings implicate transcriptional and chromatin regulation as major determinants of the response to fasting and unravels the complex, multi-TF nature of this response.
A Carathe´odory-Hamilton-Jacobi theory for infinite-horizon optimal control problems

In this paper, we extend Caratheodory's concept of equivalent variational problems to infinite-horizon optimal control problems. In such a setting, the usual concept of a minimum need not exist, and we therefore consider a weaker definition of optimality, known as catching up optimality. The extension presented here leads us to a Hamilton-Jacobi theory for infinite-horizon optimal control problems that closely parallels the classical work of Caratheodory as well as providing sufficient conditions for optimality. Finally, we show that the results given here subsume several previously known results as a special case.
Comparison of transillumination and histologic slide measurements of choroidal melanoma.

Objective: To compare transillumination and histologic slide measurements of choroidal melanomas in 479 eyes randomized to enucleation in the Collaborative Ocular Melanoma Study. Design: Transillumination defects were measured during gross examination of enucleated eyes. Tumor basal diameter and height were measured on histologic slides and each tumor was assigned to 1 of 8 distinct shape categories. Comparison of the transillumination and histologic slide measurements revealed 3 categories of difference: underestimation (transillumination measurement more than 4 mm smaller than the histologic slide measurement), overestimation (transillumination measurement more than 4 mm larger than the histologic slide measurement), and agreement within 4 mm. Results: There was good correlation between transillumination and histologic slide estimates of largest basal diameter, particularly when the basal diameter was 16 mm or less. Measurement discrepancies were related to the shape of the tumors but not to the presence of subretinal fluid or fixation. Conclusion: Agreement was high between measurements of transillumination defect and histologic sections.
Early trimester anesthetic exposure: Incidence rates in an urban hospital population

A common medical belief is that prenatal exposure to local anesthetics is infrequent and of minor concern. This paper documents substantial prenatal dental anesthestic exposure in 229 consecutive births in an urban hospital. Exposure rate is related to potential neonatal behavioral changes reported in animals and humans following prenatal anesthetic exposure.
Toward A Process-Oriented Theory of Human Skilled Performance

Skilled perceptual-motor performance should be approached from a point of view of the processing operations performed by S in a skilled task. This perspective is emphasized in recent attempts to develop analytic or computer-simulation models of tracking tasks. These models are illustrated, and it is argued that a model that has a discrete correction compensatory path and a continuously programmed pursuit path may form one starting point for a more general representation. This representation needs to incorporate as yet undefined processing and storage units to handle coherence prediction, memorized movement patterns, and compensation for external system dynamics.
The preprojective partition for hereditary artin algebras

The purpose of this paper is to study the preprojective partition of a hereditary artin algebra. For a hereditary algebra of finite representation type, we give some numerical invariants in terms of the length of chains of irreducible maps, also in terms of the length of the maximal indecomposable module, and the orientation of the quiver of the algebra. Similar results are given for algebras stably equivalent to hereditary artin algebras.
Photo-assisted silicon micromachining: opportunities for chemical sensing

Abstract Micromachining methods allow for the fabrication of small, three-dimensional structures including membranes, micro-valves, and pumps, channels, etc., in materials such as silicon. When integrated with microcircuitry this provides for the opportunity of creating unique miniature ‘smart’ chemical sensing devices. We present a novel method of photo-assisted electrochemical silicon micromachining which allows for the fabrication of stress-free submicrometer thick beams, membranes, and high aspect ratio three-dimensional structures, whose complex surface topologies were previously inaccessible by conventional processing routes. We discuss a number of gas and chemical sensor structures which benefit from MEMS technology and would benefit further from the processing versatility provided by our new micromachining fabrication method.
NaI detector neutron activation spectra for PGNAA applications

Abstract When NaI detectors are used in prompt gamma-ray neutron activation analysis devices, they are activated by neutrons that penetrate the detector. While thermal neutron filters like boron or lithium can be used to reduce this activation, it can never be completely eliminated by this approach since high energy neutrons can penetrate the detector and thermalize inside it. This activation results in the emission of prompt gamma rays from both the I and Na and the production of the radioisotopes 128 I and 24 Na that subsequently decay and emit their characteristic beta particles and gamma rays. The resulting three spectra represent a background for this measurement. An experimental method for obtaining these three spectra is described and results are reported for 2″ × 2″, 5″ × 5″, 6″ × 6″, and 1″ × 6″ NaI detectors using the thermal neutron beam of the NCSU PULSTAR nuclear reactor. In addition, Monte Carlo simulation programs have been developed and used for simulating these spectra. Good results have been obtained by the Monte Carlo method for the two radioisotope spectra, and it is anticipated that good results will also be obtained for the prompt gamma-ray spectrum when the I and Na coincidence schemes are known.
Macrophage roles following myocardial infarction

Following myocardial infarction (MI), circulating blood monocytes respond to chemotactic factors, migrate into the infarcted myocardium, and differentiate into macrophages. At the injury site, macrophages remove necrotic cardiac myocytes and apoptotic neutrophils; secrete cytokines, chemokines, and growth factors; and modulate phases of the angiogenic response. As such, the macrophage is a primary responder cell type that is involved in the regulation of post-MI wound healing at multiple levels. This review summarizes what is currently known about macrophage functions post-MI and borrows literature from other injury and inflammatory models to speculate on additional roles. Basic science and clinical avenues that remain to be explored are also discussed.
The brain-machine disanalogy

The comparative study of information processing in brains and machines leads to a picture in which disanalogies are more fundamental than analogies. The major dichotomy is between evolvability and programmability. Brain models, to be tenable, must pass an extended Turing test in which the capacity to self organize through the Darwinian mechanism of variation and selection is a key element. Programmable machines that simulate the type of structure-function relations that allow evolution to occur are, however, too inefficient in their use of resources for problem solving to support cognitive abilities comparable to those of biological organisms. Furthermore, real evolutionary systems are open in that it is always possible for them to tap previously unexploited physical interactions for computing. Nevertheless, computer simulation provides a powerful tool for studying brain function; and non-programmable designs that exploit the high efficiency, high adaptability domain of computing are in principle possible.
Individual, temporal, and population-level variations in circulating 11-ketotestosterone and 17β-estradiol concentrations in the oyster toadfish Opsanus tau

Sex steroid hormones are important for reproduction in all vertebrates, but few studies examine inter-individual, temporal, and population-level variations, as well as environmental influences on circulating steroid levels within the same species. In this study we analyzed plasma 11-ketotoestosterone (11-KT) and 17beta-estradiol (E(2)) levels in the oyster toadfish to test for 1) individual and temporal variations by serially sampling the same individuals during the reproductive and post-reproductive period, 2) variations in steroid levels among toadfish obtained from different sources or maintained under different holding conditions, and 3) correlations with environmental parameters. Results from serial sampling showed marked inter-individual variations in male 11-KT levels in two separate groups of toadfish, but no temporal differences from June to September. Females also showed inter-individual variations in E(2) concentrations, but most had elevated levels late in the reproductive season coincident with oocyte growth prior to winter quiescence. E(2) concentration, but not 11-KT, was positively correlated with water temperature, and negatively correlated with daylength and lunar phase. Maricultured toadfish held under constant conditions had elevated levels of E(2) and 11-KT that should be considered when using these fish for experimentation. This study provides important comparative information on the relationship between individual variations in steroid levels, and how they relate to physiological and environmental correlates in a model marine teleost.
Neutron induced pion production on C, Al, Cu, and W at 200-600 MeV

Inclusive double differential neutron induced ${\mathrm{\ensuremath{\pi}}}^{+}$ and ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ production cross sections were measured as a function of neutron energy for four targets: C, Al, Cu, and W. The neutron energy range was 200\char21{}600 MeV and the pion angular range was 25\ifmmode^\circ\else\textdegree\fi{}\char21{}125\ifmmode^\circ\else\textdegree\fi{} (laboratory). The charge, scattering angle, and energy of the pions were measured. The measurements are compared with intranuclear cascade (INC) calculations and a previous experiment that measured the sum of the ${\mathrm{\ensuremath{\pi}}}^{+}$ and ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$ cross sections. Our data agree with the measured data, but the INC calculations give only moderate agreement both with the double differential cross sections as well as with angular distributions and total cross sections as a function of neutron energy. The ratio ${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$:${\mathrm{\ensuremath{\pi}}}^{+}$ was found to increase rapidly with decreasing neutron energy and the pion production was found to increase approximately as ${\mathit{A}}^{2/3}$ for the different targets.
Impact of Preoperative Symptoms on Survival After Surgical Correction of Organic Mitral Regurgitation Rationale for Optimizing Surgical Indications

Background—Surgical correction of mitral regurgitation in patients with no or mild symptoms remains controversial, particularly because the impact of preoperative symptoms on postoperative outcome is unknown. Methods and Results—The long-term outcome of 478 patients with organic mitral regurgitation (199 in NYHA functional class I/II and 279 in class III/IV before surgery) operated on between 1984 and 1991 was analyzed. In patients in NYHA class I/II before surgery compared with those in class III/IV, postoperative long-term survival was higher (at 10 years, 76±5% versus 48±4%, P<0.0001), with lower operative mortality (0.5% versus 5.4%, P=0.003) and better late survival (P<0.0001). Comparison of observed and expected survival showed identical curves in patients in class I/II before surgery (P=0.18), whereas excess mortality was observed in patients in class III/IV before surgery (P<0.0001). Excess mortality associated with severe symptoms was also confirmed in all subgroups (all P<0.003) and in multivari...
Heparin II domain of fibronectin mediates contractility through an α4β1 co-signaling pathway

In the trabecular meshwork (TM) of the eye, regulation of tissue contractility by the PPRARI sequence within the Heparin II (HepII) domain of fibronectin is believed to control the movement of aqueous humor and dictate the level of intraocular pressure. This study shows that the HepII domain utilizes activated alpha4beta1 integrin and collagen to mediate a co-signaling pathway that down-regulates contractility in TM cells. siRNA silencing of alpha4beta1 integrin blocked the actin disrupting effects of both PPRARI and the HepII domain. The down-regulation of the actin cytoskeleton and contractility did not involve syndecan-4 or other heparan sulfate proteoglycans (HSPGs) since siRNA silencing of syndecan-4 expression or heparitinase removal of cell surface HSPGs did not prevent the HepII-mediated disruption of the actin cytoskeleton. HepII-mediated disruption of the cytoskeleton depended upon the presence of collagen in the extracellular matrix, and cell binding studies indicated that HepII signaling involved cross-talk between alpha4beta1 and alpha1/alpha2beta1 integrins. This is the first time that the PPRARI sequence in the HepII domain has been shown to serve as a physiological alpha4beta1 ligand, suggesting that alpha4beta1 integrin may be a key regulator of tissue contractility.
Elucidating the domain architecture and functions of non-core RAG1: The capacity of a non-core zinc-binding domain to function in nuclear import and nucleic acid binding

The repertoire of the antigen-binding receptors originates from the rearrangement of immunoglobulin and T-cell receptor genetic loci in a process known as V(D)J recombination. The initial site-specific DNA cleavage steps of this process are catalyzed by the lymphoid specific proteins RAG1 and RAG2. The majority of studies on RAG1 and RAG2 have focused on the minimal, core regions required for catalytic activity. Though not absolutely required, non-core regions of RAG1 and RAG2 have been shown to influence the efficiency and fidelity of the recombination reaction. Using a partial proteolysis approach in combination with bioinformatics analyses, we identified the domain boundaries of a structural domain that is present in the 380-residue N-terminal non-core region of RAG1. We term this domain the Central Non-core Domain (CND; residues 87-217). We show how the CND alone, and in combination with other regions of non-core RAG1, functions in nuclear localization, zinc coordination, and interactions with nucleic acid. Together, these results demonstrate the multiple roles that the non-core region can play in the function of the full length protein.
Relation of apolipoprotein E phenotype to myocardial infarction and mortality from coronary artery disease

The apolipoprotein E polymorphism is a genetic determinant of low-density lipoprotein (LDL) cholesterol. Its status as a risk factor for coronary artery disease (CAD), either through a causal relation with LDL cholesterol level or independently, is less clearly established. Data from the Multiple Risk Factor Intervention Trial were used to examine the influence of apolipoprotein E phenotype on risk of coronary events. Of the 12,866 randomized participants, 619 were studied in a nested case-control design. CAD deaths (93) and nonfatal myocardial infarctions (113) were matched to 412 controls. The allele frequencies of apolipoprotein E in the white subset (epsilon 2 = 0.06, epsilon 3 = 0.79, and epsilon 4 = 0.15) were very similar to other nonselected white American populations, and the relation of apolipoprotein E on total and LDL cholesterol was generally similar to that seen in other studies, with the epsilon 2 allele being associated with lower and the epsilon 4 allele with higher total and LDL cholesterol. Allele frequencies were not the same for patients and control subjects. The presence of epsilon 4 was associated with an increased risk of CAD that was most evident for fatal cases. There was no relation between changes in LDL cholesterol over time during the trial and apolipoprotein E phenotypes.
Early activation events induced by the staphylococcal superantigen toxic shock syndrome toxin-1 in human peripheral blood monocytes.

Abstract Staphylococcal exotoxins (SE) bind to MHC class II molecules and induce the production of IL-1β and TNF-α in human monocytic cells. Here we show that stimulation of peripheral blood monocytes with toxic shock syndrome toxin-1 (TSST-1) induced rapid increase in tyrosine phosphorylation of cytosolic protein substrates, accumulation of inositol phosphates, and de novo tyrosine phosphorylation of the PLC-γ1 isozyme. Accumulation of inositol phosphates was inhibited by preincubation of cells with inhibitors of protein tyrosine kinases (PTK). Stimulation of monocytes with TSST-1 furthermore led to activation of protein kinase C (PKC). PTK and PKC activation plays a role in the induction of monokine gene transcription by SE because inhibitors of PTK and PKC reduced TSST-1-stimulated IL-1β and TNF-α gene expression. We therefore propose a model in which the induction of monokine gene transcription by TSST-1 in monocytes necessitates activation of tyrosine kinase(s) and of PKC, the latter probably by way of PLC-γ1.
Antiviral Therapy: Analysis of Long-term Efficacy and Safety

Despite the adoption of universal vaccination in many countries, chronic hepatitis B virus (HBV) infection continues to be a global problem. Morbidity and mortality from this infection, although possibly declining, remains significant. Fortunately, our treatment armamentarium has expanded exponentially in the past decade. Newer antiviral agents are not only effective against HBV infection, but they also confer a lower risk for virologic resistance than the first-generation oral nucleoside, lamivudine. In this article, the long-term efficacy and safety of available antiviral therapy in the treatment of chronic hepatitis B are reviewed, and differences in drug potencies, side-effect profiles, and risks of development of virologic resistance are discussed to provide guidance for optimal choices for long-term antiviral therapy.
Granule cell activity in the cerebellum during delay eyelid conditioning

Although granule cell activity is crucial in defining the information processing performed by the cerebellum, in vivo single unit recordings of granule cells are scarce. Granule cells, which make more than half of all neurons in the brain, are not currently amenable to in vivo recordings due to their small size. To compensate for this lack of experimental data we performed an optimization analysis that predicts the dynamics of granule cell activity during delay eyelid conditioning. We used a simplified version of a model developed by Mauk and Donegan to optimize granule cell activity given that we have available eyelid conditioned responses for interstimulus intervals ranging from 100 to 750 ms. The solutions found by the optimization algorithm converge on three important aspects of stimulus evoked activity of the granule cells: (a) during stimulus presentation different granule cells become active at different times, (b) for the majority of granule cells the duration of the stimulus evoked responses is not dependent on the duration of the stimulus and (c) peaks of granule cell activity are preceded and/or followed by inhibition. While the first feature has been suggested to be the byproduct of interactions between granule and Golgi cells, the latter two predictions are novel. The utility of these predictions is supported by tests in a detailed simulation of the cerebellum.
Toward Reconciling Equity Theory and Insufficient Justification

Equity theory and insufficient justification theory seem to make discrepant predictions about how a person will respond to being inequitably underpaid. The equity prediction is that underpaid subjects will be dissatisfied and work less hard than equitably paid subjects; the insufficient justification (or task enhancement) prediction is that underpaid subjects will enhance their attitudes toward the task to justify doing it and in turn work harder than equitably paid subjects. This study has shown that both responses occur, but in different situations. When there was some ambiguity about the inequity, subjects restored equity by enhancing their attitudes toward the task and inputs to the situation; whereas when there was no ambiguity, subjects restored equity by being less satisfied and working less hard.
Low-dimensional, morphologically accurate models of subthreshold membrane potential.

The accurate simulation of a neuron’s ability to integrate distributed synaptic input typically requires the simultaneous solution of tens of thousands of ordinary differential equations. For, in order to understand how a cell distinguishes between input patterns we apparently need a model that is biophysically accurate down to the space scale of a single spine, i.e., 1 μm. We argue here that one can retain this highly detailed input structure while dramatically reducing the overall system dimension if one is content to accurately reproduce the associated membrane potential at a small number of places, e.g., at the site of action potential initiation, under subthreshold stimulation. The latter hypothesis permits us to approximate the active cell model with an associated quasi-active model, which in turn we reduce by both time-domain (Balanced Truncation) and frequency-domain ( ${\cal H}_2$ approximation of the transfer function) methods. We apply and contrast these methods on a suite of typical cells, achieving up to four orders of magnitude in dimension reduction and an associated speed-up in the simulation of dendritic democratization and resonance. We also append a threshold mechanism and indicate that this reduction has the potential to deliver an accurate quasi-integrate and fire model.
Controlling the Gap Myocytes, Matrix, and Mechanics

See related article, pages 558–566 Effective myocardial contraction depends in part on the efficient propagation of electrical signals through the tissue. The principal structure allowing for such rapid myocardial depolarization is the gap junction plaque, a collection of intercellular pores located primarily at intercalated discs. There, at myocyte poles, gap junctions function in close proximity to the complexes responsible for cell–cell tethering—desmosomes and fascia adherens junctions. Thus, the intercalated disc is the site of both intercellular coupling and adhesion. Gap junctions are formed by clusters of paired hexamers, one from each cell, which bridge to form a low-resistance intercellular channel facilitating the transmission of ions and small molecules (<1000 kD). Each hexamer (or connexon) is comprised of six individual connexins, a diverse protein family found in vascular, neural, and cardiac tissue. In humans, ventricular gap junctions are formed primarily from connexin43 (Cx43), a 43-kD protein encoded by chromosome 6.1 Cx43 is a dynamic molecule, with rapid turnover (t1/2 roughly 1 hour)2 and responsiveness to a variety of mechanical and chemical stimuli. Myocyte connectivity, as mediated by gap junctions, depends not only on net expression of Cx43, but on effective translocation of Cx43 to the cell surface, the phosphorylation state of both Cx43 and associated proteins,3 and intracellular pH.4 Ventricular Cx43 net protein expression is downregulated in various cardiac disease conditions such as end-stage ischemic,5 idiopathic,5 hypertrophic,1,6 and tachycardia-induced induced cardiomyopathies,7 myocardial ischemia and hibernation,8 and allograft rejection.9 …
Multiple Approaches to Analyzing Count Data in Studies of Individual Differences: The Propensity for Type I Errors, Illustrated with the Case of Absenteeism Prediction

The present study compares eight models for analyzing count data: ordinary least squares (OLS), OLS with a transformed dependent variable, Tobit, Poisson, overdispersed Poisson, negative binomial, ordinal logistic, and ordinal probit regressions. Simulation reveals the extent that each model produces false positives. Results suggest that, despite methodological expectations, OLS regression does not produce more false positives than expected by chance. The Tobit and Poisson models yield too many false positives. The negative binomial models produce fewer than expected false positives.
Fee-for-data: a strategy to open the HMO black box

Abstract: This paper outlines a simple proposal to maintain utilization data in the face of managed care growth. Health maintenance organizations (HMOs) would be required to submit claims (encounter-level data) and in return would be paid a percentage of what Medicare would pay fee-for-service providers. The capitation payment rate would be lowered to maintain budget-neutrality. This proposal would enable the collection of key data that might not otherwise be captured in a Medicare program dominated by HMOs and other forms of managed care. The data are necessary to drive Medicare policies and to gauge the impact of changes to the program. The program would be well advised to make the small additional investment to make the data system complete. The key issue in implementing such a proposal will be HMOs' ability to generate those data at reasonable cost.
Modeling of a cracked metallic structure with bonded composite patch using the three layer technique

Abstract Due to the high computational cost of three-dimensional finite element analysis, the two-dimensional finite element analysis involving the three layer technique is introduced to investigate the repair of cracked metallic structures using an adhesively bonded composite patch. In the three layer technique, two-dimensional Mindlin plate elements with transverse shear deformation capability are used for all three layers; cracked plate, adhesive and composite patch. The accuracy of the three layer technique to compute the stress intensity factor for the metallic crack is demonstrated by a comparison with available two- and three-dimensional models. The strain energy release rates of the debond at the adhesive interfaces are also examined and compared with the previous studies. The three layer technique provides an efficient and accurate alternative model which is capable of investigating in depth the adhesive effects on the bonded patch repair of cracked metallic structures.
AN URBAN FRONTIER: Respatializing Government in Remote Northern Australia

This essay draws on ethnographic research with Aboriginal Australians living in the parks and bush spaces of a Northern Australian city to analyze some new governmental measures by which remoteness comes to irrupt within urban space and to adhere to particular categories of people who live in and move through this space. To address this question in contemporary Northern Australia is also to address the changing character of the Australian government of Aboriginal people as it moves away from issues of redress and justice toward a state of emergency ostensibly built on settler Australian compassion and humanitarian concern. It also means engaging with the mediatization of politics and its relation to the broader, discursive shaping of such spatial categories as remote and urban. I suggest that remoteness forms part of the armory of recent political efforts to reshape Aboriginal policy in Northern Australia. These efforts leverage remoteness to diagnose the ills of contemporary Aboriginal society, while producing remoteness itself as a constitutive feature of urban space.