cssi/SciSciGPT-SciSciNet huggingface dataset:
Nucleotide sequence of an Escherichia coli tRNA (Leu 1) operon and identification of the transcription promoter signal

Fourteen different DNA fragments containing Escherichia coli tRNA genes have been cloned using the vector pBR322. We report the methods of cloning, the identification of specific tRNA genes, and the presence or absence of rRNA genes on these cloned DNA fragments. In particular, one chimeric plasmid contains a 17.0 kilobase pair EcoRI fragment bearing tRNA(Leu 1) sequences. Using nucleotide sequence analysis we have identified a cluster of three tandem tRNA(Leu 1) genes separated by intergenic spacers of 27 and 34 base pairs, respectively. The nucleotide sequence upstream of the first gene contains a transcription promoter site. A G-C rich sequence (5'-CGCCTCC-3') found between the Pribnow box and initiation site is very similar to the corresponding sequence found in other genes which are under stringent control.
The crystal structure of Ca3Cu3(PO4)4

Abstract Single crystals of Ca3Cu3(PO4)4 synthesized hydrothermally at 420°C and 55 kpsi (3.8 kbar) were found to occur in the space group P2 1 a (No. 14) with a = = 17.619(2), b = 4.8995(4), c = 8.917(1)A, β = 124.08(1)°, and Z = 2. Full-matrix least-squares refinement of the structure using diffractometer data converged to a final anisotropic R = 0.037 (Rw = 0.046). The two calcium atoms are in six- and nine-coordination and the two copper-containing polyhedra (four- and five-coordinated) are similar to those previously found in Cu3(PO4)2.
A Survey and Analysis of Techniques for Player Behavior Prediction in Massively Multiplayer Online Role-Playing Games

While there has been much research done on player modeling in single-player games, player modeling in massively multiplayer online role-playing games (MMORPGs) has remained relatively unstudied. In this paper, we survey and evaluate three classes of player modeling techniques: 1) manual tagging; 2) collaborative filtering; and 3) goal recognition. We discuss the strengths and weaknesses that each technique provides in the MMORPG environment using desiderata that outline the traits an algorithm should posses in an MMORPG. We hope that this discussion as well as the desiderata help future research done in this area. We also discuss how each of these classes of techniques could be applied to the MMORPG genre. In order to demonstrate the value of our analysis, we present a case study from our own work that uses a model-based collaborative filtering algorithm to predict achievements in World of Warcraft. We analyze our results in light of the particular challenges faced by MMORPGs and show how our desiderata can be used to evaluate our technique.
Economic analysis of medical practice variation between 1991 and 2000: the impact of patient outcomes research teams (PORTs).

Objectives: The aim of this study was to examine the impact of the multi-hundred million dollar investment by the federal government in the developing Patient Outcomes Research Teams (PORTs) in over a dozen major academic medical centers in the United States throughout the 1990s. The objective of the PORTs was to reduce unnecessary clinical variation in medical treatment. Methods: Using an economic derivation of welfare loss attributable to medical practice variation and hospital admission claims data for 2 million elderly patients generalizable to the nation, we estimate the change in welfare between 1991 and 2000, the period within which the PORTs were designed and executed and their results disseminated. Results: Our results show inpatient admission types targeted by the PORTs did have less welfare loss relative to their total expenditure by 2000, but that there was not a net decrease in the welfare loss for all hospital admissions affected by the PORT. Conclusions: We conclude that PORTs may have had favorable effects on welfare, most likely by reducing variation in clinical care, but that causality cannot be proved, and the effects were not equal across all conditions targeted by PORTs. This research provides a methodological template that may be used to evaluate the impact of patient safety research on welfare loss and on variation in medical treatment in both hospital and ambulatory settings.
Synthesis and Characterization of Acetone-Terephthalaldehyde Polymer and its Oligomers

Abstract We report the synthesis of several oligomers of defined structure and the polymer arising from the base-catalyzed condensation of acetone and terephthalaldehyde. We have characterized these materials by IR, NMR, and elemental analysis. The preparation of oligomer ATA requires an acetone/ terephthalaldehyde ratio ∼ 50:1; otherwise, only polymer results. We explain this observation on the basis of enolate equilibria. The interaction of these compounds with Lewis acids produces oxonium ions.
Inherited neuropathies: from gene to disease.

Abstract Inherited disorders of peripheral nerves represent a common group of neurologic diseases. Charcot-Marie-Tooth neuropathy type 1 (CMT1) is a genetically heterogeneous group of chronic demyelinating polyneuropathies with loci mapping to chromosome 17 (CMT1A), chromosome 1 (CMT1B) and to another unknown autosome (CMT1C). CMT1A is most often associated with a tandem 1.5-megabase (Mb) duplication in chromosome 17p11.2-12, or in rare patients may result from a point mutation in the peripheral myelin protein-22 (PMP22) gene. CMT1B is associated with point mutations in the myelin protein zero (P0 or MPZ) gene. The molecular defect in CMT1C is unknown. X-linked Charcot-Marie-Tooth neuropathy (CMTX), which has clinical features similar to CMT1, is associated with mutations in the connexin32 gene. Charcot-Marie-Tooth neuropathy type 2 (CMT2) is an axonal neuropathy, also of undetermined cause. One form of CMT2 maps to chromosome 1p36 (CMT2A), another to chromosome 3p (CMT2B) and another to 7p (CMT2D). Dejerine-Sottas disease (DSD), also called hereditary motor and sensory neuropathy type III (HMSNIII), is a severe, infantile-onset demyelinating polyneuropathy syndrome that may be associated with point mutations in either the PMP22 gene or the P0 gene and shares considerable clinical and pathological features with CMT1. Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder that results in a recurrent, episodic demyelinating neuropathy. HNPP is associated with a 1.5-Mb deletion in chromosome 17p11.2-12 and results from reduced expression of the PMP22 gene. CMT1A and HNPP are reciprocal duplication/deletion syndromes originating from unequal crossover during germ cell meiosis. Other rare forms of demyelinating peripheral neuropathies map to chromosome 8q, 10q and 11q. Hereditary neuralgic amyotrophy (familial brachial plexus neuropathy) is an autosomal dominant disorder causing painful, recurrent brachial plexopathies and maps to chromosome 17q25.
Prevalence of Spindle Cell Sarcomas among Wild Canada Geese from Southern Illinois

Over a 6-yr period, two cases of neoplastic disease were diagnosed among 1,272 wild Canada geese (Branta canadensis interior) collected in Illinois (USA), Wisconsin (USA), and Ontario, Canada. One juvenile goose of each sex was involved. In both cases >35 discrete masses were observed subdermally, intramuscularly, and within the body cavity. The tumors, diagnosed as spindle cell sarcomas, are among the most commonly observed neoplasms in free-living North American waterfowl. Based on our data, we suggest that these neoplasms occur with extremely low prevalence (0.002%) in free-living Canada geese.
The implementation and evaluation of the use of CORBA in an engineering design application

Many computer applications today require some form of distributed computing to allow different software components to communicate. Several different commercial products now exist based on the Common Object Request Broker Architecture (CORBA) of the Object Management Group. The use of such tools, however, often requires the modification of existing systems, rather than the development of new applications. The objective of this research has been to integrate the use of a CORBA tool into an existing engineering design application for the purpose of (1) evaluating the amount of re-engineering that is involved to effectively integrate distributed object computing into an existing application, and (2) evaluating the use and performance of distributed object computing in an engineering domain, which often requires the transfer of large amounts of information. The results of this work demonstrate that CORBA technology can be easily integrated into existing applications. The ease of the integration as well as the efficiency of the resulting system, however, depends upon the degree of modification that developers are willing to consider in the re-engineering process. The most transparent approach to the use of CORBA requires less modification and generally produces less efficient performance. The less transparent approach to the use of CORBA can potentially require significant system modification but produce greater performance gains. This work outlines issues that must be considered for the partitioning of functionality between the client and the server, development of an IDL interface, development of client and server-side wrappers, and support for concurrent, multi-user access. In addition, this work also provides performance and implementation comparisons of different techniques for the use of wrappers and for the transfer of large data files between the client and the server. Performance comparisons for the incorporation of concurrent access are also presented. Copyright © 1999 John Wiley & Sons, Ltd.
A New Tool for Studying the in Situ Growth Processes for Self-Assembled Monolayers under Ambient Conditions

A new tool for studying self-assembled monolayer (SAM) nucleation and growth processes on faceted inorganic substrates under ambient conditions is reported herein. The methodology involves coating an atomic force microscope tip with molecules of interest and raster scanning across a substrate of interest with the modified tip. Large scale images of the deposition process provide kinetic information about the nucleation and growth of SAMs. The water meniscus, which is the transport medium in these experiments, is proposed to strongly influence the growth process for 1-octadecanethiol and 16-mercaptohexadecanoic acid. The former involves an island formation and subsequent growth behavior while the latter shows evidence of more random growth. Lattice-resolved images of both SAM structures have been obtained at the end of film growth, and in the case of the 1-octadecanethiol SAM, lattice-resolved images were obtained for the SAM islands. The virtues of this novel technique are its simplicity, adsorbate genera...
Optical tearing in spatiotemporal boundary formation: when do local element motions produce boundaries, form, and global motion?

—Perception of continuous boundaries, shape, and global motion can be produced by transformations in local elements separated in both space and time, a process here called spatiotemporal boundary formation (SBF). Prior research has shown that a broad class of element transformations gives rise to SBF. The present work used the transformation of local element displacement to explore the initiating conditions for SBF. Three experiments assessed SBF using a 10-alternative, forced-choice, shape identification task. Experiment la showed that large element displacements, but not small ones, produced high accuracy in shape identification. Experiment Ib tested the detectability of the small and large element displacements in an unrelated task, indicating that the results of Experiment 1a were not due to poor detectability for small displacements. Experiment 2 found no variation in SBF performance with changes in viewing distance. Experiment 3 provided evidence that initiating SBF depends on a ratio of element displacement to element separation. These results support an interpretation of SBF as a process geared to detection of object boundaries from spatiotemporal change. Initiating SBF requires transformations in local elements that are classified as spatiotemporal discontinuities (STDs). Small element displacements in a display of a given density do not register as STDs because they are classified as local deformations in an intact, implicit surface connecting visible elements. Complementarity is suggested between element changes which preserve continuity with their neighbors (optic flow) and those comprising spatiotemporal discontinuities (optic tearing). Classification of element transformations as optic flow or tearing may determine whether they provide information about surface form (e.g., through structure-from-motion) or about object boundaries, through SBF.
Lysophosphatidic acid increases phosphatidic acid formation, phospholipase D activity and degranulation by human neutrophils.

1-Oleoyl-sn-glycero-3-phosphate, a lysophosphatidic acid (LPA), in serum is a biologically active lipid and has multiple functions depending on the cell types. Several studies have shown that LPA stimulates phospholipase D (PLD) activity in fibroblasts and prostate cancer cells in culture. PLD plays a central role in regulating neutrophil functions. One of the functions of the lipid product, phosphatidic acid (PA), of PLD action in neutrophils is to promote degranulation. In the present study, we examined the effect of LPA on PLD activity and degranulation by human neutrophils. The results show that exogenous LPA increased PA formation, PLD activity and degranulation by human neutrophils in a time and concentration dependent manner. These findings suggest that LPA released from activated platelets during blood clotting may participate in bacterial killing and wound healing process. On the other hand, augmented LPA production might be involved in inflammation, causing damage of the host tissues.
THE SYSTEMIC AND CORONARY HEMODYNAMIC EFFECTS OF DIAZOXIDE.

Abstract 1. 1. Hemodynamic studies, including the determination of cardiac output and coronary blood flow, have been made before and after the intravenous administration of diazoxide to anesthetized intact dogs and unanesthetized man. The response was essentially the same in the dog and in man. 2. 2. Administration of this agent intravenously was accompanied by an acute reduction in peripheral, total pulmonary, and coronary resistances, with a decrease in systemic and pulmonary arterial pressures and an increase in cardiac output and coronary blood flow. 3. 3. Coronary sinus oxygen content increased, with the per cent increase in coronary blood flow significantly greater than the change in cardiac rate, left ventricular work, and left ventricular oxygen consumption. 4. 4. The acute hemodynamic effects of diazoxide in control animals are not significantly different from the effects in animals pretreated with chlorothiazide or small doses of reserpine. 5. 5. Although both diazoxide and chlorothiazide are benzothiadiazine derivatives, their acute hemodynamic effects differ greatly.
Phenotyping of type II and IV hyperlipoproteinemias by a simple, quantitative agarose gel lipoprotein electrophoresis

Abstract From the statistical analysis of the densitometric percentage counts derived from 97 lipoprotein electrophoreses from patients with Type II or Type IV hyperlipoproteinemia, we developed a simple sequential screening approach. The method is highly accurate in assigning patients to their proper diagnostic classification. Also, the method is nonparametric, i.e., distribution-free, and considers one variable at a time for discrimination. This method, apart from sampling errors, does not give misclassified patients, but may give some undecided cases.
A graph theoretic approach to the analysis of alliance structure and local grouping in highland New Guinea

Abstract This paper focuses on a set of structural properties which characterize the Gahuku‐Gama, a social and cultural unit in the Eastern Central Highlands of New Guinea. Gahuku‐Gama “society” has been described as a finite network, the members of which are social groups connected by bonds of traditional warfare and alliance. The aims of the paper are (1) to formalize some ordinary English terms which have been applied to this system; (2) to elucidate these properties through the application of graph theoretic concepts and theorems; (3) to use certain of these theorems in the prediction of empirical facts of local grouping; and (4) to suggest that this approach could usefully be adopted in relation to similar sociocultural systems in Highland New Guinea and elsewhere.
Repair of potentially mutagenic damage, sensitive to anisotonic treatment, in actively growing Chinese hamster cells.

SummaryUsing exponentially growing Chinese hamster V79 cells we studied the effect of anisotonic phosphate-buffered saline (PBS) treatment on the frequency of mutation following X-irradiation. Induction of mutants was studied at the hypoxanthine-guanine phosphoribosyl transferase locus (HGPRT). When cells were X-irradiated and immediately followed by 0·5 m NaCl/PBS treatment for 20 min at 37°C, cell survival was significantly decreased and a concomitant increase in the number of mutants was observed, indicating that postirradiation treatment with anisotonic salt solution caused conversions of potentially lethal damage and potentially mutagenic damage to lethal and mutagenic damage, respectively. The repair kinetics of potentially mutagenic damage expressible by 0·5 m NaCl/PBS after 5·86 Gy of X-rays were similar to those of potentially lethal damage. The repair of both types of damage was essentially complete within 40 min after X-irradiation.
Advances in comparative protein-structure modelling

Comparative modelling of protein 3D structure can now be applied with reasonable accuracy to ten times more protein sequences than the number of experimentally determined protein structures. A protein sequence that has at least 40% identity to a known structure can be modelled automatically with an accuracy approaching that of a low resolution X-ray structure or a medium resolution NMR structure. Currently, the errors in comparative models include mistakes in the packing of sidechains, in the conformation and shifts of the core segments and loops, and, most importantly, in an incorrect alignment of the modelled sequence with related known structures. Nevertheless, the number of applications in which comparative modelling has been proven to be useful has grown rapidly.
Composition and origin of material in pre-columbian pottery, San Salvador Island, Bahamas

Thin-section analysis and X-ray diffraction analysis indicates that pre-Columbian Indian pottery of San Salvador Island, Bahamas is composed of angular fragments of invertebrate shells bound by clay and quartz. The source of the clay and quartz apparently was soil formed from dust accumulating over thousands of years by atmospheric deposition of material transported from North Africa. No evidence of biogenic siliceous material is found in pottery sherds native to the island. An atmospheric origin for the clay and quartz is supported strongly by clay/quartz ratios and quartz particle sizes in atmospheric dust presently being transported from North Africa compared to a soil (paleosol?) sample from Pigeon Creek Indian Site, San Salvador Island.
A Comparison of global and local probabilistic approximations in mining data with many missing attribute values

We present results of a novel experimental comparison of global and local probabilistic approximations. Global approximations are unions of characteristic sets while local approximations are constructed from blocks of attributevalue pairs. Two interpretations of missing attribute values are discussed: lost values and “do not care” conditions. Our main objective was to compare global and local probabilistic approximations in terms of the error rate. For our experiments we used six incomplete data sets with many missing attribute values. The best results were accomplished by global approximations (for two data sets), by local approximations (for one data set), and for the remaining three data sets the experiments ended with ties. Our next objective was to check the quality of non-standard probabilistic approximations, i.e., probabilistic approximations that were neither lower nor upper approximations. For four data sets the smallest error rate was accomplished by non-standard probabilistic approximations, for the remaining two data sets the smallest error rate was accomplished by upper approximations. Our final objective was to compare two interpretations of missing attribute values. For three data sets the best interpretation was the lost value, for one data set it was the “do not care” condition, for the remaining two cases there was a tie.
The Development and Validation of a Test Battery Measuring Specific Cognitive Abilities in Four-Year-Old Children:

A battery of nine specific cognitive abilities tests to assess verbal, spatial, perceptual speed, and memory abilities in children at age 4 was constructed and administered to a sample of 267 children participating in the Colorado Adoption Project. Exploratory and confirmatory factor analyses revealed four correlated factors that adequately describe the covariation among the tests. Specific cognitive ability composites showed test-retest correlations ranging from .56 to .81. The reliable measurement of these specific cognitive abilities in preschool children facilitates analyses of familial resemblance and longitudinal comparisons.
A Model Study of Zonal Forcing in the Equatorial Stratosphere by Convectively Induced Gravity Waves

A two-dimensional cloud-resolving model is used to examine the possible role of gravity waves generated by a simulated tropical squall line in forcing the quasi-biennial oscillation (QBO) of the zonal winds in the equatorial stratosphere. A simulation with constant background stratospheric winds is compared to simulations with background winds characteristic of the westerly and easterly QBO phases, respectively. In all three cases a broad spectrum of both eastward and westward propagating gravity waves is excited. In the constant background wind case the vertical momentum flux is nearly constant with height in the stratosphere, after correction for waves leaving the model domain. In the easterly and westerly shear cases, however, westward and eastward propagating waves, respectively, are strongly damped as they approach their critical levels, owing to the strongly scale-dependent vertical diffusion in the model. The profiles of zonal forcing induced by this wave damping are similar to profiles given by critical level absorption, but displaced slightly downward. The magnitude of the zonal forcing is of order 5 m s21 day21. It is estimated that if 2% of the area of the Tropics were occupied by storms of similar magnitude, mesoscale gravity waves could provide nearly 1/4 of the zonal forcing required for the QBO.
Cardio-pulmonary function in preascitic (hypoxemic) or normal broilers inhaling ambient air or 100% oxygen

Abstract We evaluated the influence of the percentage saturation of hemoglobin with oxygen (HbO2) on the pulmonary arterial pressure in normal and preascitic (hypoxemic) broilers breathing ambient air or 100% O2. In Experiment 1, unanesthetized preascitic broilers (right:total ventricular weight ratios [RV:TV] = 0.32±0.02) breathing ambient air had initial values of 67% for HbO2 and 32 mm Hg for pulmonary arterial pressure. The HbO2 increased to > or =96.6% during inhalation of 100% O2; however, pulmonary arterial pressure was not reduced. In Experiment 2, anesthetized normal (RV:TV = 0.23; HbO2 = 88%) and preascitic broilers (RV:TV = 0.28; HbO2 = 76%) were compared. The groups did not differ in body weight or respiratory rate, but preascitic broilers had lower values for mean arterial pressure, total peripheral resistance, and partial pressure of O2 in arterial blood and had higher values for pulmonary arterial pressure. Inhaling 100% O2 increased HbO2 to 99.9% in both groups; however, pulmonary arterial pressure remained higher in preascitic than in normal broilers, and the pulmonary vascular resistance was not reduced during 100% O2 inhalation. Cardiac output was higher in preascitic than in normal broilers before and after, but not during, 100% O2 inhalation. Mean arterial pressure and total peripheral resistance increased in the preascitic but not in the normal group during 100% O2 inhalation. Low coefficients of determination R2 were obtained for linear regression comparisons of HbO2 vs. pulmonary arterial pressure in both experiments. Overall, acute reversal of the systemic hypoxemia in preascitic broilers had little direct impact on pulmonary hypertension, providing no evidence of hypoxemic or hypoxic pulmonary vasoconstriction. Instead, acute reversal of the systemic hypoxemia primarily increased the total peripheral resistance and normalized the mean arterial pressure and cardiac output. A sustained reduction in cardiac output theoretically should attenuate pulmonary hypertension, but this was not observed because of the overriding influence of sustained pulmonary vascular resistance.
Predicting Thermal Characteristics of Particle Laden Thermal Interface Materials

Particle laden Thermal Interface Materials (TIMs) are used extensively in thermal packaging of electronic components to enhance the heat transfer between heat dissipating components and the thermal management layers. In this paper, the thermal performance of particle laden TIMs is studied numerically, using the Lattice Boltzmann method. The effect of particle volume fraction, particle size and the thermal conductivity ratio on the thermal performance of particle laden TIMs are examined. The results for the effective thermal conductivity of particle laden greases are in agreement with the existing analytical and experimental results reported in the literature.Copyright © 2009 by ASME
High-throughput fluorescence polarization assay to identify small molecule inhibitors of BRCT domains of breast cancer gene 1.

Abstract The C-terminus region of the 1863 residue early onset of breast cancer gene 1 (BRCA1) nuclear protein contains a tandem globular carboxy terminus domain termed BRCT. The BRCT repeats in BRCA1 are phosphoserine- and/or phosphothreonine-specific binding modules. The interaction of the BRCT(BRCA1) domains with phosphorylated BRCA1-associated carboxyl terminal helicase (BACH1) is cell cycle regulated and is essential for DNA damage-induced checkpoint control during the transition from the G 2 phase to the M phase of the cell cycle. Development of a competitive, homogeneous, high-throughput fluorescence polarization (FP) assay to identify small molecule inhibitors of BRCT(BRCA1)–BACH1 interaction is reported here. The FP assay was used for measuring binding affinities and inhibition constants of BACH1 peptides and small molecule inhibitors of BRCT(BRCA1) domains, respectively. A fluorescently labeled wild-type BACH1 decapeptide ( BDP1 ) containing the critical phosphoserine, a phenylalanine at (P + 3), and a GST–BRCT fusion protein were used to establish the FP assay. BDP1 has a dissociation constant ( K d ) of 1.58 ± 0.01 μM and a dynamic range (ΔmP) of 164.9 ± 1.9. The assay tolerates 20% dimethyl sulfoxide, which enables screening poorly soluble compounds. Under optimized conditions, a Z ′ factor of 0.87 was achieved in a 384-well format for high-throughput screening.
Aft Fan Duct Acoustic Radiation

A finite element code has been developed for the prediction of the radiated acoustic field from the aft fan duct of a turbofan engine. The acoustic field is modelled based on the assumption that the steady flow in and around the nacelle is irrotational as is the acoustic perturbation. The geometry of the nacelle is axisymmetric and the acoustic source is harmonic and decomposed into its angular harmonics. The steady flow is computed on the acoustic mesh and provides data for the acoustic calculations. The jet is included in the steady flow potential flow model by separating the interior and exterior flow outside the aft fan duct with a thin barrier created by disconnecting the computational domain. The jet and exterior flow are allowed to merge at a defined distance downstream. In the acoustic radiation model continuity of acoustic particle velocity is implicitly satisfied across the shear layer by careful treatment of the surface integral which appears in the finite element method (FEM) formulation. Pressure continuity is enforced by using a penalty constraint on the shear layer. A model for locally reacting acoustic treatment provides a boundary condition on the duct walls. An attempt has been made to limit reflections on the artificial baffle introduced to limit the computational domain, but this is only moderately successful. An old, but reliable frontal solution routine has been updated with considerable impact on computational time. Example calculations are given which show the success achieved in satisfying the complicated interface conditions on the shear layer and the characteristics of the solutions at relatively high frequencies where the refinement of the mesh becomes a limiting consideration for practical computations.
Patch dynamics of a foraging assemblage of bees.

The composition and dynamics of foraging assemblages of bees were examined from the standpoint of species-level arrival and departure processes in patches of flowers. Experiments with bees visiting 4 different species of flowers in subalpine meadows in Colorado gave the following results: 1) In enriched patches the rates of departure of bees were reduced, resulting in increases in both the number of bees per species and the average number of species present. 2) The reduction in bee departure rates from enriched patches was due to mechanical factors-increased flower handling time, and to behavioral factors-an increase in the number of flowers visited per inflorescence and in the number of inflorescences visited per patch. Bees foraging in enriched patches could collect nectar 30–45% faster than those foraging in control patches. 3) The quantitative changes in foraging assemblages due to enrichment, in terms of means and variances of species population sizes, fraction of time a species was present in a patch, and in mean and variance of the number of species present, were in reasonable agreement with predictions drawn from queuing theory and studies in island biogeography. 4) Experiments performed with 2 species of flowers with different corolla tube lengths demonstrated that manipulation of resources of differing availability had unequal effects on particular subsets of the larger foraging community.
Transitioning to professional practice: A deweyan view of five analyses of problem‐based learning

The collection of five articles analyzing an episode of problem‐based learning (PBL) in a medical school is rich with conversation, mediating objects, and layered intentions of the participants. Video proves itself to be a medium that can provide common ground to a thoroughly encompassing set of perspectives in discourse analysis, ranging from Vygotskian to cognitive theories, linguistic to sociotechnical orientations, and concerns both local to PBL and fundamental to the social sciences. Beyond merely exploring methodological possibilities, the five articles can be seen to take an important first step toward resolving a critical issue of learning theory, which was first articulated by John Dewey: How do we understand the boundary between commonsense and technical forms of reasoning, action, and discourse? By what means do students grow from everyday to specialized forms of practices? This collection suggests a possible resolution to this issue through multidisciplinary, layered, and nuanced discourse ana...
Immune complexes in the rheumatic diseases.

The serum sickness model of immune complex disease developed by Germuth’ and Dixon and associate? some 2.5 years ago remains the prototype for the study of human diseases in which immune complexes are suspected of playing a role. Fig. 1 shows some of the most important criteria for implicating immune complexes in the pathogenesis of inflammatory lesions. An increase in the rate of clearance of intravenously administered ‘311-labeled antigen at day 10, a fall in the level of serum complement, the appearance of antigen complexed to antibody in the blood, and, in addition, the presence of antigen, antibody, and complement components in the lesions demonstrable by fluorescein-labeled antibodies provide convincing evidence for this cause-and-effect relationship. Although systemic lupus erythematosus (SLE) is a relatively rare disease (prevalence, 14 to 48 per 100,000 population),” nonetheless, because of the large number of immunologic abnormalities associated with it, it has become the subject of intense investigation over the past 20 years. Low serum complement levels have been recognized as characteristic of this disease since 195 1’ and a clear relationship with the presence and severity of renal disease has been documented.” Deposits of immunoglobulins and complement components in a location between the endothelial cell layer and the basement membrane in a lumpy, bumpy pattern mimicking that of experimental serum sickness is characteristic of lupus nephritis.6 Immune complex-like material has been detected in the plasma of lupus patients by a number of techniques, most of which depend on binding of IgG aggregates to Clq7 or to receptors for IgG and complement components on cells.x For some as yet unexplained reason these aggregates in lupus sera cannot be detected with monoclonal rheumatoid factors
Viral pancreatitis: ultrastructural pathological effects of Coxsackievirus B3 infection in newborn mouse pancreas.

Abstract An electron microscopic study of Coxsackievirus B3-infected newborn mice revealed pathological changes in both the endocrine and exocrine portions of the pancreas. Damage ranged from a focal degeneration in which small areas of individual cells were affected to a widespread necrosis and inflammation in which entire acini and islets were so changed that identification of individual cell types was difficult. Compound membrane-vesicle complexes typical of picornavirus infection and virus particles in various arrays were observed in the acinar cells and macrophages. Fibrosis of the islets and a thickening of the basal laminae of associated capillaries were noted also. Comparisons were made to the pancreatitis caused by this and other group B Coxsackieviruses in both human and experimental animals.
Alumina as a Desilicohalogenating Agent in the Stereoselective Synthesis of Vinyl Halides

Abstract Recently we reported a stereoselective synthesis of vinyl halides using vinylsilanes as precursors (see Scheme I).1 In the desilicohalogenation step an oxygen base (NaOMe) was used, necessitating a strongly basic media in a polar solvent.
Awareness, different learning conditions, and second language development

This study investigated the role of awareness in different learning conditions in relation to second language (L2) development. Adult learners of Spanish were exposed to past conditional sentences in one of five versions of a computerized problem-solving task that vary in their degree of explicitness. By employing both on-line and off-line data elicitation procedures, two main issues were addressed: whether exposure to L2 input under different conditions had a differential impact on learners' awareness and whether different levels of awareness influenced learners' ability to recognize and produce new exemplars of the target structure immediately after exposure to the input and over time. Results indicated that higher levels of awareness were not only associated with more explicit conditions but were also substantially more effective than lower levels.
Mode of Operation of Ampullae of Lorenzini of the Skate, Raja

Ampullae of Lorenzini are sensitive electroreceptors. Applied potentials affect receptor cells which transmit synaptically to afferent fibers. Cathodal stimuli in the ampullary lumen sometimes evoke all-or-none "receptor spikes," which are negative-going recorded in the lumen, but more frequently they evoke graded damped oscillations. Cathodal stimuli evoke nerve discharge, usually at stimulus strengths subthreshold for obvious receptor oscillations or spikes. Anodal stimuli decrease any ongoing spontaneous nerve activity. Cathodal stimuli evoke long-lasting depolarizations (generator or postsynaptic potentials) in afferent fibers. Superimposed antidromic spikes are reduced in amplitude, suggesting that the postsynaptic potentials are generated similarly to other excitatory postsynaptic potentials. Anodal stimuli evoke hyperpolarizations of nerves in preparations with tonic activity and in occasional silent preparations; presumably tonic release of excitatory transmitter is decreased. These data are explicable as follows: lumenal faces of receptor cells are tonically (but asynchronously) active generating depolarizing responses. Cathodal stimuli increase this activity, thereby leading to increased depolarization of and increased release of transmitter from serosal faces, which are inexcitable. Anodal stimuli act oppositely. Receptor spikes result from synchronized receptor cell activity. Since cathodal stimuli act directly to hyperpolarize serosal faces, strong cathodal stimuli overcome depolarizing effects of lumenal face activity and are inhibitory. Conversely, strong anodal stimuli depolarize serosal faces, thereby causing release of transmitter, and are excitatory. These properties explain several anomalous features of responses of ampullae of Lorenzini.
A Review of: “Medicare Prospective Payment and the Shaping of U.S. Health Care by Rick Mayes and Robert A. Berenson”

Medicare Prospective Payment and the Shaping of U.S. Health Care. Rick Mayes and Robert A. Berenson. Baltimore, MD: Johns Hopkins University Press, 2006. 245 pages. ISBN: 9780801884542 Contemporary...
Where Have All the Towers Gone? the Dismantling of Public Housing in U.S. Cities

ABSTRACT:Public housing authorities (PHAs) across the country are demolishing and selling off public housing units. Although some of the units are being replaced in mixed-income developments, most are not; the subsidies instead are being shifted into household-based vouchers. Thus, in most cases the loss of these units is a permanent reduction in the nation’s public housing stock. Demolition efforts are more extensive in some cities than in others. This paper analyzes public housing removal in the largest cities of the United States to explain the pattern of demolitions taking place. The analysis reveals that public housing removal is most prevalent in cities facing gentrification pressures, and in cities in which the management of public housing by the local housing authorities was subpar. Public housing removals are also associated with higher levels of racial segregation and violent crime.
New technologies to support teaching for understanding

Abstract In this era of rapid change, educators increasingly recognize that students must learn how to develop and apply knowledge creatively, not simply remember what they have been told. To meet these demands, teachers need professional development opportunities that support them in a transformational process. New technologies appear to hold promise in overcoming the traditional limitations of professional development. In this chapter, we describe and analyze a program designed to provide such professional development. We begin by summarizing recurrent challenges and promising approaches to professional development organized around a set of qualities that characterize effective learning. Next, we use these qualities to describe a program that explicitly incorporates a model of teaching for understanding into the design of an online learning environment and professional development activities for educators. Finally, our analysis of this program emphasizes the Internet's unique advantages, as well as some remaining issues to resolve in online professional development for educators. In this era of rapid change, educators increasingly recognize that students must learn how to develop and apply knowledge creatively, not simply remember what they have been told. This goal requires shifting from traditional lessons based on transmitting information toward approaches that help learners build robust and flexible understanding. Such transformation of curriculum and pedagogy is a complex process for teachers who must develop new knowledge, skills and beliefs. To meet these demands, teachers need professional development opportunities that support them in a transformational process. Unfortunately, most learning opportunities for teachers fall short. They tend to be short-term workshops, focused on general topics rather than deep knowledge of subject matter and pedagogy, inattentive to teachers’ individual interests, disconnected from specific classroom practices, and isolated from ongoing support by coaches and colleagues. Formal professional development activities are often the antithesis of what is known to promote effective learning. New technologies appear to hold promise in overcoming the traditional limitations of professional development. The World Wide Web, with its rich trove of multimedia resources, interactive tools, and telecommunication facilities, accessible from anywhere on the planet, seems full of potential as a facilitator of teacher learning. Yet we know that mere access to technical resources is not sufficient to generate learning or to change practice. How might the Internet be used to support communities of reflective practitioners committed to teaching for understanding?
A novel dynamic Vt circuit configuration

Summary form only given. It is a well known dilemma that as supply voltages are scaled lower, CMOS threshold voltages must also be scaled lower to maintain performance, leading to increased subthreshold leakage. One solution to mitigate the trade-off between high performance and low standby current is to modulate the threshold voltage by control of the well or body voltage, lowering the Vt in active mode and raising the Vt in standby. SOI is particularly suited for this because of the relatively low body capacitance, and the wider practical range of body vs well voltage. Developing circuit techniques to leverage this advantage may be critical to the successful commercialization of SOI technology. In this work, we propose a modification of the drain-to-body configuration that significantly reduces gate delay and is particularly appropriate for large drivers where a series of inverters is used. The basic configuration is to tie the drain of the transistor to the body of the transistor when the transistor is turned on, disconnecting it when the transistor is off. To evaluate the circuit design technique, simulations were run for a variety of configurations for three inverters in series.
Mean‐strain eight‐node hexahedron with stabilization by energy sampling

Summary A method for stabilizing the mean-strain hexahedron is described that differs from the currently known approaches. For simplicity, the developments are limited to linear elasticity but with an arbitrarily anisotropic elasticity matrix. The technique relies on a sampling of the stabilization energy using two quadrature rules, the mean-strain quadrature and the full Gaussian integration rule. The use of two quadrature rules is shown to guarantee consistency and stability. The stabilization energy is assumed to be generated by a modified constitutive matrix based on the spectral decomposition. The spectral decomposition of the constitutive matrix identifies the stiff and flexible modes of deformation. The stiff modes of deformation are only sampled by the mean-strain integration, which eliminates volumetric locking for isotropic materials as well as locking due to strongly anisotropic material properties. The accuracy and convergence characteristics of the present formulations compare favorably with the capabilities of mean-strain and other high-performance hexahedral elements as implemented in ABAQUS. Copyright © 2014 John Wiley & Sons, Ltd.
369 Tflop/s molecular dynamics simulations on the Roadrunner general-purpose heterogeneous supercomputer

We present timing and performance numbers for a short-range parallel molecular dynamics (MD) code, SPaSM, that has been rewritten for the heterogeneous Roadrunner supercomputer. Each Roadrunner compute node consists of two AMD Opteron dualcore microprocessors and four PowerXCell 8i enhanced Cell microprocessors, so that there are four MPI ranks per node, each with one Opteron and one Cell. The interatomic forces are computed on the Cells (each with one PPU and eight SPU cores), while the Opterons are used to direct inter-rank communication and perform I/O-heavy periodic analysis, visualization, and checkpointing tasks. The performance measured for our initial implementation of a standard Lennard-Jones pair potential benchmark reached a peak of 369 Tflop/s double-precision floating-point performance on the full Roadrunner system (27.7% of peak), corresponding to 124 MFlop/Watt/s at a price of approximately 3.69 MFlops/dollar. We demonstrate an initial target application, the jetting and ejection of material from a shocked surface.
OPTICAL CHARACTERISTICS OF THE CANINE PROSTATE AT 665 NM SENSITIZED WITH TIN ETIOPURPURIN DICHLORIDE: NEED FOR REAL-TIME MONITORING OF PHOTODYNAMIC THERAPY

ABSTRACT Purpose: Photodynamic therapy (PDT) is an emerging, minimally invasive therapy for prostate cancer that depends on the sequestration of a photosensitizing drug within targeted tissue. The photosensitizer is subsequently activated by light of a specific wavelength, resulting in destruction of the targeted tissue. Successful treatment requires knowledge of the optical properties of the target tissue, a critical element for therapy. Materials and Methods: Adult canines were injected with tin etiopurpurin dichloride (1.0 mg/kg) as a liposome emulsion vehicle in saline 24 hours prior to light treatment. Laser light was delivered to the prostate via a 400 μm optical fiber fitted with a 2.0 cm cylindrical diffuser and optical properties of the prostate were measured. Results: In this study we determined the attenuation coefficient and critical fluence in the canine prostate. Our studies shown that the attenuation coefficient is not uniform but higher at the base (average for all animals 2.59 to 2.79 cm −1 ) than in the mid section or apex of the prostate (1.71 to 1.90 cm −1 ). Significant differences among dogs (0.11 to 12.70 cm −1 ) were found. In some cases we observed a fluctuation of the attenuation coefficient during treatment. We also established experimentally the minimum energy (1449 mJ/cm 2 ) needed (critical fluence) to produce necrosis. Experimentally establishing the values of effective attenuation and critical fluence is necessary to predict the area of ablation during PDT and protect surrounding organs from over treatment. Conclusions: Based on our results it is evident that for PDT of the prostate to be successful the optical parameters of the prostate must be measured and monitored during treatment. We suggest that the optimum way of doing this is real-time computerized monitoring combined with simulation PDT.
Multiple Tendon Ruptures of Unknown Etiology

Tendon ruptures are common findings in foot and ankle practice. The etiology of tendon ruptures tends to be multifactorial-usually due to a combination of trauma, effects of systemic diseases, adverse effects of medications, and obesity. We present an unusual case of right Achilles tendinitis, left Achilles tendon rupture, bilateral peroneus longus tendon rupture, and left peroneus brevis tendon rupture of unknown etiology. This case report highlights the need for research for other possible, lesser known etiologies of tendon pathology. Level of evidence Therapeutic, Level IV, Case Study.