cssi/SciSciGPT-SciSciNet huggingface dataset:
Bacterial Exposure Induces and Activates Matrilysin in Mucosal Epithelial Cells

Matrilysin, a matrix metalloproteinase, is expressed and secreted lumenally by intact mucosal and glandular epithelia throughout the body, suggesting that its regulation and function are shared among tissues. Because matrilysin is produced in Paneth cells of the murine small intestine, where it participates in innate host defense by activation of prodefensins, we speculated that its expression would be influenced by bacterial exposure. Indeed, acute infection (10-90 min) of human colon, bladder, and lung carcinoma cells, primary human tracheal epithelial cells, and human tracheal explants with type 1-piliated Escherichia coli mediated a marked (25-50-fold) and sustained (>24 h) induction of matrilysin production. In addition, bacterial infection resulted in activation of the zymogen form of the enzyme, which was selectively released at the apical surface. Induction of matrilysin was mediated by a soluble, non-LPS bacterial factor and correlated with the release of defensin-like bacteriocidal activity. Bacteria did not induce matrilysin in other cell types, and expression of other metalloproteinases by epithelial cells was not affected by bacteria. Matrilysin was not detected in germ-free mice, but the enzyme was induced after colonization with Bacteroides thetaiotaomicron. These findings indicate that bacterial exposure is a potent and physiologically relevant signal regulating matrilysin expression in epithelial cells.
Hybrid silicon photonic integrated circuits for optical networking

We describe the design and results of several hybrid silicon devices that combine benefits of III-V semiconductors with silicon-based platforms. Presented work includes a silicon-on-insulator evanescent phase modulator and a recirculating buffer using silica waveguides.
The Porphyrias: Characteristics and Laboratory Tests [corrected title]

Abstract The term porphyria represents seven neuropathic and/or dermopathic diseases caused by disturbances of the heme-forming system. Accumulation of the heme precursor, δ-aminolevulinic acid (δALA), is associated with the neurologic manifestations, and accumulation of photoreactive by-products, the porphyrins, causes cutaneous photosensitivity and dermopathic manifestations. The degrees of expression range from mild to severe, and acute episodes of neuropathic porphyrias can progress to paralysis and life-threatening respiratory failure. Diagnostic laboratory tests include quantitation of δALA, porphobilinogen, and porphyrins in blood, urine, and feces and analysis of activities of enzymes of the heme-forming system. Both inheritable and noninheritable forms of porphyria can be induced by toxic chemicals, and, therefore, tests for porphyria are becoming included increasingly in examinations of persons who have experienced problematic chemical exposures.
Synthesis and properties of substituted rhodicinium salts

Abstract Rhodicinium salts with the following substituents; H, CH3, 1,1′-(CH3)2, CO2H, 1,1′-(CO2H)2, 1,1′-(COCl)2, 1,1′-(CO2CH3)2 and 1,1′-(NH2)2 have been prepared as their hexafluorophosphate salts by the procedure previously employed for synthesis of the corresponding cobalticinium salts. The rhodicinium salts are paler in color but similar in stability and physical and chemical properties to the corresponding cobalticinium salts. IR, UV and 1H and 13C NMR spectra of the rhodicinium salts and their cobalticinium and ferrocene analogs are discussed. The basicity of 1,1′-diaminorhodicinium in aqueous acid, pk1 = 13.36 ± 0.06, pk2 = 17.04 ± 0.06, was determined spectrophotometrically. The values for the corresponding 1,1′-diaminocobalticinium salt are pk1 = 13.5 ± 0.1 and pk2 = 18.1 ± 0.1. The slightly greater basicity of the 1,1′-diaminorhodicinium is attributed to the greater separation of the cyclopentadienyl rings which moves the amino groups farther from the positively charged metal atom and from each other.
Effects of protracted cadmium exposure on gametes of the purple sea urchin, Arbacia punctulata.

Gametes and larvae of sea urchins and more specifically Arbacia punctulata have been used extensively in embryological studies and toxicity bioassay testing. Most of the experiments and bioassays have used the fertilized eggs of different sea urchin species and measured abnormal growth, malformations, or changes in the rates of growth as a function of contaminant exposure. Guida demonstrated that cupric ion activities of <10{sup -10.5} M caused reductions in the rates of growth of Arbacia Punctulata larvae and caused incomplete or malformed pluteal skeletons. These effects occurred at cupric ion concentrations that were in the same ranges as some measured in the more contaminated estuaries in the northeastern U.S. Sunda and coworkers also used sea urchin embryonic development to test potential trace metal toxicity in water samples collected from those same estuaries, and demonstrated toxicity potentially attributable to dissolved trace metals in the water column. The purpose of these experiments was to determine if protracted sublethal exposure of sexually mature sea urchins to dissolved cadmium in sea water would affect the viability of eggs and sperm, and whether it would affect fertilization and embryonic development and ultimately the larvae. The results of the experiments support the hypothesis that spermatogenesis andmore » oogenesis were affected by cadmium exposure.« less
Electronic structure and band lineups at the diamond/boron nitride and diamond/nickel interfaces

Abstract Using both Gaussian local-orbital and linearized augmented plane wave basis sets, we have carried out self-consistent local-density-functional calculations of the electronic structure and bonding characteristics of an ideal unrelaxed diamond/BN (110) interface, and of a series of ideal diamond/Ni (100) and (111) interfaces. Our results include predictions of the band line-ups across the interfaces (the valence and conduction band discontinuities) in the former case, and the Schottky barrier height in the latter case. The diamond/BN system is predicted to be a type-II system, while the calculated diamond/Ni Schottky barrier heights depend strongly on the coordination of Ni atoms at the interface.
Highly Divergent Methyltransferases Catalyze a Conserved Reaction in Tocopherol and Plastoquinone Synthesis in Cyanobacteria and Photosynthetic Eukaryotes

Tocopherols are lipid-soluble compounds synthesized only by photosynthetic eukaryotes and oxygenic cyanobacteria. The pathway and enzymes for tocopherol synthesis are homologous in cyanobacteria and plants except for 2-methyl-6-phytyl-1,4-benzoquinone/2-methyl-6-solanyl-1,4-benzoquinone methyltransferase (MPBQ/MSBQ MT), which catalyzes a key methylation step in both tocopherol and plastoquinone (PQ) synthesis. Using a combined genomic, genetic, and biochemical approach, we isolated and characterized the VTE3 (vitamin E defective) locus, which encodes MPBQ/MSBQ MT in Arabidopsis. The phenotypes of vte3 mutants are consistent with the disruption of MPBQ/MSBQ MT activity to varying extents. The ethyl methanesulfonate–derived vte3-1 allele alters tocopherol composition but has little impact on PQ levels, whereas the null vte3-2 allele is deficient in PQ and α- and γ-tocopherols. In vitro enzyme assays confirmed that VTE3 is the plant functional equivalent of the previously characterized MPBQ/MSBQ MT (Sll0418) from Synechocystis sp PCC6803, although the two proteins are highly divergent in primary sequence. Sll0418 orthologs are present in all fully sequenced cyanobacterial genomes, Chlamydomonas reinhardtii, and the diatom Thalassiosira pseudonana but absent from vascular and nonvascular plant databases. VTE3 orthologs are present in all vascular and nonvascular plant databases and in C. reinhardtii but absent from cyanobacterial genomes. Intriguingly, the only prokaryotic genomes that contain VTE3-like sequences are those of two species of archea, suggesting that, in contrast to all other enzymes of the plant tocopherol pathway, the evolutionary origin of VTE3 may have been archeal rather than cyanobacterial. In vivo analyses of vte3 mutants and the corresponding homozygous Synechocystis sp PCC6803 sll0418::aphII mutant revealed important differences in enzyme redundancy, the regulation of tocopherol synthesis, and the integration of tocopherol and PQ biosynthesis in cyanobacteria and plants.
Dopability, intrinsic conductivity, and nonstoichiometry of transparent conducting oxides.

Existing defect models for ${\mathrm{In}}_{2}{\mathrm{O}}_{3}$ and ZnO are inconclusive about the origin of conductivity, nonstoichiometry, and coloration. We apply systematic corrections to first-principles calculated formation energies $\ensuremath{\Delta}H$, and validate our theoretical defect model against measured defect and carrier densities. We find that (i) intrinsic acceptors (``electron killers'') have a high $\ensuremath{\Delta}H$ explaining high $n$-dopability, (ii) intrinsic donors (``electron producers'') have either a high $\ensuremath{\Delta}H$ or deep levels, and do not cause equilibrium-stable conductivity, (iii) the O vacancy ${V}_{\mathrm{O}}$ has a low $\ensuremath{\Delta}H$ leading to O deficiency, and (iv) ${V}_{\mathrm{O}}$ has a metastable shallow state, explaining the paradoxical coexistence of coloration and conductivity.
The determinants of fertility: A theoretical forecasting model

The conceptual framework of a fertility model for forecasting population changes is presented. Beginning with the individual state of a fecund woman in a given year, the model considers the impact of three factors on her decision-making process with respect to fertility in the following year. The model uses a four state Markov chain, with transitional probabilities based upon the decision process of each woman aged 14–45 as it is affected by the annual rate of change in real per capita income, in level of education and in rural-urban employment. From the Markov chain, the number of live births that can be expected in a future time period given the size of the female population of childbearing age and the impact of economic development can be estimated. Thus, the model attempts to develop a theory of fertility that conceptually interrelates significant socioeconomic factors, individual behavior and the process of economic development, thereby providing a tool for predicting future births. Provisions to refine the model by incorporating additional socioeconomic factors are suggested.
Attitudes, Opinions, and Characteristics: Creating a Profile of Sales Students

This study was conducted with the objective of identifying and assessing factors that influence students to have a disposition toward a sales career as well as positive attitudes toward salespeople. Two studies were conducted to measure the impact of different treatments. Data were collected from 263 undergraduate students in marketing and/or sales-related classes, in order to empirically test two experiments. The results of ordinary least-squares regression analysis indicate that students enrolled in sales-related classes are much more likely to have a disposition toward a sales career and to have a positive attitude toward salespeople, while simply reading a passage describing the sales profession and how it is likely for many college graduates to have a career in sales had little impact. The implications include the development of a sales students’ profile, which describes students who are likely to pursue sales as a career and to have a positive attitude toward salespeople. This profile can be important in identifying potentially successful members of professional sales forces while they are still in our universities and by doing so, enable sales educators to properly prepare them for their careers.
Self-forcing of a chemostat with self-sustained oscillations for productivity enhancement

The effects of self-forcing simple limit-cycle type self-sustained oscillations (SSO) on a single chemostat with the aim to enhance its productivity was investigated using four different microbial systems with increasing complexities. It was demonstrated via simulation that for a chemostat with monod-type growth and with substrate-and-product-inhibited growth and product formation, it is possible to increase its productivity several fold by self-forcing the chemostat with SSO without incurring extra costs normally associated with external periodic forcing. Despite significant difference in the models used to simulate the chemostats, all four systems show a similar pattern of behavior in their productivity-vs.-mean residence time plots.
External and material damped three dimensional rotor system

Abstract This paper extends and improves previous work by the authors on the motion of a whirling elastic shaft-disc system. Using an energy technique the effects of external damping, linear and non-linear internal damping, linear and non-linear elastic restoring forces and non-linear inertia forces are isolated and investigated. The results are summarized in the form of stability theorems. In addition, using techniques previously developed by the authors, solutions to the linear damped system, for both the homogeneous and non-homogeneous cases, are presented. Apart from being of interest in their own right use is made of them in the non-linear analysis.
Electrochemical charging of a fullerene-functionalized self-assembled monolayer on au(111).

A fullerene derivative 10 with a terminal thiol group dissolves easily in common organic solvents and forms a densely packed self-assembled monolayer on gold surfaces. The functionalization of C60 is based on the 1,3-dipolar cycloaddition of the azomethine ylide generated in situ from the corresponding aldehyde and N-methylglycine. The monolayers were characterized by grazing angle reflectance FTIR spectroscopy, scan tunneling microscopy, and cyclic voltammetry. The cyclic voltammogram of a SAM of 10 showed two well-resolved reversible cathodic waves corresponding to the first two one-electron reductions of the fullerene fragment.
An experimental model of hemothorax autotransfusion: Impact on coagulation

Abstract Background Traumatic hemothorax (HTX) has been demonstrated to predictably contain low fibrinogen, low hematocrit, and low platelet counts. When analyzed on its own, shed HTX demonstrates coagulopathy. However, when mixed with normal pooled plasma (NPP) at physiologically relevant dilutions, HTX demonstrates accelerated coagulation. We hypothesize that when HTX is mixed with a patient's own plasma, the mixture will demonstrate hypercoagulability. The accelerated coagulation of this mixture would have important implications for the autotransfusion of HTX as a method of resuscitating a trauma patient. Methods Adult trauma patients from whom greater than 140 mL of HTX was evacuated within 1 hour of tube thoracostomy were included. HTX was sampled at 1 hour after evacuation, and a portion of the sample was centrifuged and stored as frozen plasma for later analysis. The remainder of the sample was analyzed (coagulation, hematology, electrolytes), and values were compared with concurrent venous values extracted via chart review. A citrate tube containing the patient's venous blood was additionally spun down and frozen for subsequent mixing study analysis. Coagulation was further evaluated by mixing serial dilutions of the previously frozen HTX with NPP. Additionally, the previously frozen HTX was mixed in serial dilutions with the previously frozen sample of patient plasma (PTP). Results Subjects (10) were enrolled based on inclusion criteria and collection of a discarded venous sample. In HTX samples analyzed alone, no thrombus was formed in any coagulation test (activated partial thromboplastin time [aPTT] > 180). The median aPTT value of PTP alone was 25.5. In 1-hour specimens mixed at a clinically relevant dilution of 1:4, HTX mixed with NPP had a mediana PTT value of 26.0, whereas HTX mixed with PTP had a median aPTT value of 21.7. Thus, the mixture of HTX + PTP demonstrated a statistically significantly lower aPTT than the mixture of HTX + NPP (P = 0.01). Additionally, the mixture of HTX and PTP shows a statistically significantly lower aPTT value than PTP alone (P = 0.03), indicating a hypercoagulable state. Conclusions HTX demonstrates coagulopathy when analyzed independently, but is hypercoagulable when mixed with NPP or PTP. Furthermore, mixing studies show a statistically significantly lower aPTT when HTX is mixed with PTP versus HTX mixed with NPP. Thus, autotransfusion of HTX would likely produce a hypercoagulable state in vivo, and should not be used in place of other blood products to resuscitate a trauma patient. The autotransfusion of HTX may, however, be of use in a resource-limited environment where other blood products are not available.
Scavenger receptor A1 is required for sensing HCMV by endosomal TLR-3/-9 in monocytic THP-1 cells.

Abstract Monocytes provide initial surveillance for pathogenic glycopeptides via scavenger receptors (SRs) and for viruses via Toll-like receptors (TLRs) which trigger pro-inflammatory response. However, specific interactions between SR-A1 and TLRs have not yet been assessed in human cytomegalovirus (HCMV)-exposed monocytes. Our results showed two patterns of gene expression upon HCMV exposure: genes that were induced within 10 min include SR-A1, Lyn, TLR-2, and IL-12p35, whereas those induced at 1 h are TLR-3, TLR-9, TRIF, IRF-3, and IFN-β. NF-κB p65 and TNF-α were elevated at both 10 min and 1 h post exposure. Further, inhibitory studies using neutralizing antibodies and morpholino antisense oligonucleotides suggested that within 10 min of HCMV exposure, transcription of TNF-α and IL-12 genes is TLR-2-dependent fashion. However, induction of both TLR-3-mediated IFN-β and TLR-9-mediated TNF-α at 1 h was dependent on SR-A1. These findings reveal a novel mechanistic insight into an interrelationship between SR-A1 and TLR-3/-9 signaling in HCMV-exposed monocytes.
Review of the effects of dietary fat on experimental mammary gland tumorigenesis: Role of lipid peroxidation

The purpose of this communication is threefold, that is, (1) to review and critique the studies designed to examine the interrelationship between dietary fat and experimental rodent mammary gland tumorigenesis, (2) to assess the influence of dietary fat on growth of human breast carcinoma transplants in immunodeficient mice, and (3) to examine and discuss the role of products of lipid peroxidation in these tumorigenic processes. It is concluded from this review and critique that the amount and type of dietary fat can significantly influence the development and/or growth of rodent mammary gland tumors and growth of human breast carcinomas in immune deficient mice. Dietary fat can be either stimulatory or inhibitory to these tumorigenic processes, phenomena that could be a function, at least in part, of the generation of products of lipid peroxidation.
Synthesis of Robust Nonlinear Autopilots Using Differential Game Theory

Synthesis of full authority flight vehicle autopilots using feedback linearisation has been previously discussed in the literature. The main concern expressed regarding the use of feedback linearization theory for flight control system design has been the issue of the controller stability and performance under modeling inaccuracies and disturbances. This paper advances a method based on differential game theory for non-linear autopilot synthesis under these conditions. The proposed approach closely parallels the linear theory.
Eighth grade students’ representations of linear equations based on a cups and tiles model

This study examines eighth grade students’ use of a representational metaphor (cups and tiles) for writing and solving equations in one unknown. Within this study, we focused on the obstacles and difficulties that students experienced when using this metaphor, with particular emphasis on the operations that can be meaningfully represented through this metaphor. We base our analysis within a framework of referential relationships of meanings (Kaput 1991; Kaput, Blanton, and Moreno, et al. 2008). Our data consist of videotaped classroom lessons, student interviews, and teacher interviews. Ongoing analyses of these data were conducted during the teaching sequence. A retrospective analysis, using constant comparison methodology, was then undertaken in order to generate a thematic analysis. Our results indicate that addition and (implied) multiplication operations only are the most meaningful with these representational models. Students also very naturally came up with a notation of their own in making sense of equations involving multiplication and addition. However, only one student was able to construct a “family of meanings” when negative quantities were involved. We conclude that quantitative unit coordination and conservation are necessary constructs for overcoming the cognitive dissonance (between the two representations—drawn pictures and the algebraic equation) experienced by students and teacher.
Computerization of a patient management problems examination to prevent ‘retracing’1

During 1973, a 10-patient, linear PMP examination was administered in both written and computerized form to 104 candidates for certification by the American Board of Pediatrics and to 122 individuals in their first month of graduate training in paediatrics. Both groups made significantly more errors of omission (failure to select appropriate actions) and fewer correct diagnoses on the computerized version of the test than on the written version. These results suggest that examinees 'retrace' (use clues from problems near the end of the case to make additional correct decisions on earlier problems) when the test is presented in written form and that computerization prevents this phenomenon. Additional analyses indicated that the reliability of the PMP examination was essentially the same for the written and computerized versions, that both forms distinguished about equally well between first-year residents and candidates, and that both forms had about the same magnitude of correlation with the American Board of Pediatrics oral examination. Finally, correlation between both PMP forms and the American Board of Pediatrics multiple-choice examination suggested that the PMP, in either mode of presentation, measures characteristics that are not tapped by the multiple-choice test. Thus, computerization of the PMP provides a means for controlling a variable (retracing) which may be considered extraneous to the desired measurement, but it does not appear to alter the reliability of the test or to modify its relations with other measures.
A spatio-temporal speech enhancement scheme for robust speech recognition in noisy environments

Abstract A new speech enhancement scheme is presented integrating spatial and temporal signal processing methods for robust speech recognition in noisy environments. The scheme first separates spatially localized point sources from noisy speech signals recorded by two microphones. Blind source separation algorithms assuming no a priori knowledge about the sources involved are applied in this spatial processing stage. Then denoising of distributed background noise is achieved in a combined spatial/temporal processing approach. The desired speaker signal is first processed along with an artificially constructed noise signal in a supplementary blind source separation step. It is further denoised by exploiting differences in temporal speech and noise statistics in a wavelet filterbank. The scheme’s performance is illustrated by speech recognition experiments on real recordings in a noisy car environment. In comparison to a common multi-microphone technique like beamforming with spectral subtraction, the scheme is shown to enable more accurate speech recognition in the presence of a highly interfering point source and strong background noise.
Lung Abscess as Seen in a Municipal Hospital

SUMMARY AND CONCLUSIONS 1.An analysis of 95 cases of lung abscess observed in a large municipal hospital revealed the disease to be one of insidious onset of a symptom complex which included cough, purulent sputum, chest pain, and hemoptysis that often occurs in a hospitalized patient who is suffering from another disease. 2.Sixty-one of the 95 patients died due either to the lung abscess or associated disease. 3.The best therapeutic results were obtained with multiple antibiotics selected on the basis of the in vitro sensitivity of pathogenic bacteria isolated from the sputum. 4.It is thought that better therapeutic results might be obtained by a higher index of suspicion regarding his disease, more vigorous attempts at isolation of the causative bacteria by bronchoscopy, and treatment by a combined medical-surgical team with multiple antibiotics selected on the basis of specific sensitivity tests.
Seeing the Forest or the Trees: Implications of Construal Level Theory for Consumer Choice

Like many important theories that were originally tested in one domain, construal level theory has broadened the notion of temporal distance to psychological distance and examined the wide ranging implications of this construct on evaluation and behavior. This commentary seeks to take a step back to admire the “forest” that has been created and suggest additional extensions and implications along the different stages of consumer decision making: goal pursuit, evaluation by way of consideration-set formation and receptivity, and finally choice influenced by context, comparability of options, and post-choice happiness and regret.
Regulatory focus and anxiety: A self-regulatory model of GAD-depression comorbidity ☆

The etiology of generalized anxiety disorder (GAD), including its high degree of comorbidity with major depressive disorder (MDD), remains a conceptual and clinical challenge. In this article, we discuss the relevance of regulatory focus theory, an influential theory of self-regulation, for understanding vulnerability to GAD as well as GAD/MDD comorbidity. The theory postulates two systems for pursuing desired end states: the promotion and prevention systems. Drawing upon studies documenting the affective and motivational consequences of failing to attain promotion versus prevention goals, as well as the literature linking promotion failure with depression, we propose how dysfunction within the prevention system could lead to GAD - with, as well as without, MDD.
Success of endovenous saphenous and perforator ablation in patients with symptomatic venous insufficiency receiving long-term warfarin therapy

Background Endovenous ablation of great (GSV) and short saphenous vein (SSV) reflux has become the initial procedure for most patients with symptomatic venous insufficiency, and perforator ablation is increasingly used to assist in healing venous ulceration. Many patients have comorbid conditions, which require long-term anticoagulation with warfarin; however, the impact of a long-term anticoagulation therapy on endovenous ablation procedures is not understood. This study aims to determine the effects of chronic anticoagulation on the outcomes of endovenous ablation procedures in patients with chronic venous insufficiency (CVI). Methods Consecutive patients undergoing endovenous ablation for to Clinical severity (CEAP) class 2 through 6 CVI between January 1, 2005 and May 1, 2011 were evaluated; 781 patients with chronic venous reflux underwent 1,180 endovenous ablation procedures. We identified 45 patients receiving long-term anticoagulation therapy who underwent 71 endovenous ablation procedures, including 37 GSVs, 12 SSVs, and 22 perforator vein procedures. All patients underwent wound examination and duplex ultrasonography within 48 to 72 hours. Outcomes evaluated included closure rate and postoperative complications. Results The mean age of the patients was 69.7 ± 13 years. Most patients treated presented with active venous ulceration (59% CEAP 6). Indications for anticoagulation included atrial fibrillation (n = 9, 20%), previous deep venous thrombosis (n = 16, 36%), hypercoagulable state (n = 9, 20%), prosthetic valve (n = 2, 4%), and others (n = 9, 20%). All patients receiving warfarin therapy (100%) underwent a postprocedure ultrasonography, which confirmed the successful closure of the GSVs and SSVs; successful initial perforator closure was achieved in 59% of patients (13/22). Repeat perforator ablation yielded a closure rate of 77%. Compared with a matched cohort group of 35 patients (61 perforators) undergoing perforator ablation without anticoagulation, treated during the same period, there was no significant difference in the rates of successful closure between the groups. No patients developed postoperative deep venous thrombosis or pulmonary embolus. No additional thrombotic complications were noted. Three patients (4.2%) developed a small hematoma after the procedure, which resolved with conservative treatment. No patients required postoperative hospital admission, and no postprocedure deaths occurred. Conclusions Based on our protocol, patients with severe CVI who were receiving long-term warfarin therapy can be treated safely and effectively with endovenous radiofrequency ablation for incompetent GSVs, SSVs, and perforator veins. Long-term warfarin therapy did not have a significant effect on perforator closure rates compared with no anticoagulation.
NUMERICAL SIMULATION OF THE BUOYANCY-INDUCED FLOW IN A PARTIALLY OPEN ENCLOSURE

A numerical study of a buoyancy-induced flow generated by a finite-size heat source located on a vertical wall of an enclosure with a single opening is carried out. A two-dimensional laminar flow is assumed. Employing a stream function vorticity formulation within the framework of the Boussinesq approximations, the temperature and the flow fields are computed. The effect of the opening on the induced flow is investigated in terms of the size and the location of the opening. Numerical results are obtained for a wide range of governing parameters, particularly the Rayleigh number. The Prandtl number is taken as that corresponding to air at normal con ditions, Pr = 0.72, and the aspect ratio of the enclosure is varied. Of particular interest were the flow generated in the vicinity of the opening, the flow adjacent to the heated surface, and any stratification that might arise in the enclosure. All these and several other relevant aspects are considered in this study. The numerical formulation for the boundar...
The hypoxia-inducible factor α pathway couples angiogenesis to osteogenesis during skeletal development

Skeletal development and turnover occur in close spatial and temporal association with angiogenesis. Osteoblasts are ideally situated in bone to sense oxygen tension and respond to hypoxia by activating the hypoxia-inducible factor alpha (HIF alpha) pathway. Here we provide evidence that HIF alpha promotes angiogenesis and osteogenesis by elevating VEGF levels in osteoblasts. Mice overexpressing HIF alpha in osteoblasts through selective deletion of the von Hippel-Lindau gene (Vhl) expressed high levels of Vegf and developed extremely dense, heavily vascularized long bones. By contrast, mice lacking Hif1a in osteoblasts had the reverse skeletal phenotype of that of the Vhl mutants: long bones were significantly thinner and less vascularized than those of controls. Loss of Vhl in osteoblasts increased endothelial sprouting from the embryonic metatarsals in vitro but had little effect on osteoblast function in the absence of blood vessels. Mice lacking both Vhl and Hif1a had a bone phenotype intermediate between those of the single mutants, suggesting overlapping functions of HIFs in bone. These studies suggest that activation of the HIF alpha pathway in developing bone increases bone modeling events through cell-nonautonomous mechanisms to coordinate the timing, direction, and degree of new blood vessel formation in bone.
Intelligent robot trends and predictions for the first year of the new millennium

An intelligent robot is a remarkably useful combination of a manipulator, sensors and controls. The current use of these machines in outer space, medicine, hazardous materials, defense applications and industry is being pursued with vigor. In factory automation, industrial robots can improve productivity, increase product quality and improve competitiveness. The computer and the robot have both been developed during recent times. The intelligent robot combines both technologies and requires a thorough understanding and knowledge of mechatronics. Today's robotic machines are faster, cheaper, more repeatable, more reliable and safer than ever. The knowledge base of inverse kinematic and dynamic solutions and intelligent controls is increasing. More attention is being given by industry to robots, vision and motion controls. New areas of usage are emerging for service robots, remote manipulators and automated guided vehicles. Economically, the robotics industry now has more than a billion-dollar market in the U.S. and is growing. Feasibility studies show decreasing costs for robots and unaudited healthy rates of return for a variety of robotic applications. However, the road from inspiration to successful application can be long and difficult, often taking decades to achieve a new product. A greater emphasis on mechatronics is needed in our universities. Certainly, more cooperation between government, industry and universities is needed to speed the development of intelligent robots that will benefit industry and society. The fearful robot stories may help us prevent future disaster. The inspirational robot ideas may inspire the scientists of tomorrow. However, the intelligent robot ideas, which can be reduced to practice, will change the world.
Glassy thermal anomalies due to dipolar reorientations? Specific heat of N2-Ar-CO alloys.

It has been previously proposed that the excess low-temperature specific heat of the orientational glass KCN-KBr is due to dipolar (\ensuremath{\pi}) reorientations. To test this assertion, we have prepared related orientational glasses ${\mathrm{N}}_{2}$-Ar-CO in which the relative concentrations of asymmetric CO and symmetric ${\mathrm{N}}_{2}$ may be varied. The low-temperature specific-heat measurements on ${\mathrm{N}}_{2}$-Ar-CO reported here for temperatures between 0.15 and 4 K demonstrate that the asymmetric CO molecules are not important to the excess heat capacity.
Understanding regression versus variance tests for social interactions

This article considers the relationship between the use of regressions and the use of variance contrast methods to uncover social interactions. We illustrate how these methods employ different identifying assumptions and are therefore complementary approaches. We also provide formal identification results that extend existing ones for the two methods. (JEL C12, C21, C23, Z13) This article is designed to understand the relationshipbetweentwoapproachestotheempirical analysis of social interactions. The first approach is the use of linear regressions to uncover social interactions. This approach estimates social interaction effects through changes in the conditional (linear) expectation of individual outcomes when group-level variables are included in the conditioning set. In econometrics, this method was first analyzed by Manski (1993), who dubbed it the linearin-means model since the group-level variables are typically averages of individual variables within the group. This model is also studied by Brock and Durlauf (2001a, 2001b), CohenCole (2006) and Graham and Hahn (2005), among others. Durlauf (2004) surveyed empirical studiesof social interactionsbasedonsuch regressions. The second approach, originally proposed by Glaeser, Sacerdote, and Scheinkman (1996) and developed into a full inferential procedure by Graham (2005), who refers to this approachasvariancecontrasts,usesintragroup variation in behavior to infer social interactions. The idea in this approach is that social interactions willinduceintragroupdependences in behavior that affect sample variances for intragroup outcomes. There has been relatively little work evaluating social interactions using variance contrasts. One reason is that with the exception of Graham’s work, there is little formal statistical theory for the approach. The purpose of this article was to clarify the relationship between regression and variance contrast tests. Weclarify how these tests employ different informational assumptions to achieve identification of social interaction. Specifically, we argue that regression and variance contrast approaches correspond to identification via exclusion restrictions in the one case and covariance restrictions on errors in the other. As such, the two approaches replicate the classes of identification strategies that appear in the classical simultaneous equations literature (see Fisher (1966), for a classic treatment). The remainder of the article is organized as
Thickness changes in polythiophene gas sensors exposed to vapor

Abstract While gas sensors made from organic semiconductors such as polythiophene are attractive devices, little work has been made to understand or monitor the interaction of these sensors with the gas analyte molecules. In this work, we report in situ thickness changes in polythiophene films by monitoring the film thickness using X-ray reflectivity during exposure to gas vapors. This is the first time that the sensor–analyte interaction has been corroborated with physical changes in the film. We find the thickness change to be relatively small and to not depend strongly on the analyte concentration. We discuss the implications of these measurements, which advance the understanding of polymer based gas sensors.
Do investors perceive the going‐concern opinion as useful for pricing stocks?

Purpose – The purpose of this paper is to conduct an experiment to examine whether investors view the going‐concern opinion as providing information that is useful in valuing companies' stocks. Prior research on this issue using archival data has produced mixed results.Design/methodology/approach – An experiment is conducted with financial analysts in which the auditor's opinion and the opinion of industry specialists (proxy for market expectations) are manipulated. Participants estimated the stock price of a fictional company both before and after the issuance of an auditor's opinion.Findings – The results strongly support the hypothesis that investors perceive the going‐concern opinion as relevant for valuing a company's common stock. Furthermore, the participants viewed the going‐concern opinion as relevant even when the report confirmed prior market expectations.Practical implications – Using a controlled setting, the paper finds that investors believe that the auditor's going‐concern opinion contains...
Macrophage release of tumor necrosis factor‐α by Mycobacterium avium antigens

Mycobacterium avium complex (MAC) infection is the most common disseminated opportunistic infection encountered in patients with AIDS. We have studied the ability of specific Mycobacterium avium (MA) antigens to stimulate human monocyte-derived macrophages (MDM) to produce tumor necrosis factor-α (TNF-α). MDM stimulated with MA sonicate, MA 68 kDa and MA 48–52 kDa antigens were found to produce TNF-α in a dose-dependent manner. Reverse transcriptase-polymerase chain reaction analysis of mRNA extracts from antigen-stimulated MDM indicated that TNF-α mRNA expression was of brief duration and the time point of peak TNF-α mRNA levels was found to be antigen-specific. A significant difference in TNF-α production in response to MA 48–52 kDa antigen and M. bovis 65 kDa antigen was observed between MDM from normal and HIV positive individuals.
Liquid chromatographic determination of indecainide, a new antiarrhythmic drug, and its major metabolite, desisopropyl indecainide, in biological samples.

Abstract A simple, sensitive, and selective method for the determination of indecainide and its metabolite, desisopropyl indecainide, in human plasma (or serum) and urine is described. The compounds are extracted from alkalinized plasma or urine samples with ethyl acetate—hexane (9:1); the solvent is evaporated under nitrogen and the residue is reconstituted in the mobile phase. The compounds are chromatographed on a Zorbax C8 column, using 0.25 M ammonium acetate—acetonitrile—methanol—tetrahydrofuran (60:20:16:4) as the eluent at 1.5 ml/min. The effluent is monitored at 270 nm or by using a fluorescence detector (λexc 270 nm, λem 315 nm).
Modeling Systems with π-π Interactions Using the Hartree-Fock Method with an Empirical Dispersion Correction

The accuracy of the Hartree–Fock method with an empirical dispersion correction, HF-D3, to model interaction energies and locate constrained minimum geometries is tested against more conventional correlation methods, such as second-order perturbation theory and coupled cluster theory, and against the sophisticated effective fragment potential model. HF-D3 was applied to substituted-benzene dimers in both sandwich and T-shaped configurations and to DNA base pair complexes in both hydrogen bonded and stacked geometries. Overall, HF-D3 is found to be a plausible and cost efficient substitute for higher levels of electronic structure theory, such as MP2, in systems with π–π interactions.
Collaborating for Performance: Or Can There Exist Such a Thing as CollaborationStat?

ABSTRACT To produce better results, a number of public agencies and governmental jurisdictions have created their own PerformanceStat leadership strategies. The New York City Police Department created the original CompStat; then Baltimore adapted the concept to create CitiStat, the strategy's first application to an entire governmental jurisdiction. As implemented by these and other agencies and jurisdictions, PerformanceStat is primarily a top-down, hierarchical effort to improve the results produced by individual public agencies. Often, however, important results can only be produced through a collaboration of public agencies. This raises the question: Can a PerformanceStat leadership strategy be adapted to situations in which improving performance requires cross-agency or even cross-jurisdiction collaboration? And if so, how? This article identifies the core concepts underlying PerformanceStat, suggests how they need to be modified to create a CollaborationStat strategy, reviews the public-management l...
Behavioral assessment of speech anxiety

The development and evaluation of an instrument for the behavioral assessment of speech anxiety is described. The BASA consists of eighteen behavioral variables which are separately rated on a ten‐point scale for degree of severity manifested during discrete speech segments. Testing of the BASA on videotape‐recorded classroom speeches of male college students provided evidence supporting its reliability and validity. Four orthogonal BASA factors resulted from varimax rotation: Rigidity, Inhibition, Disfluency, and Agitation.
Sensitivity Analysis of Discrete Structural Systems

Methods for calculating sensitivity derivatives for discrete structural systems are surveyed, primarily covering literature published during the past two decades. Methods are described for calculating derivatives of static displacements and stresses, eigenvalues and eigenvectors, transient structural response, and derivatives of optimum structural designs with respect to problem parameters. The survey is focused on publications developed in nonstructural fields such as electronics, controls, and physical chemistry which are directly applicable to structural problems. Most notable among the nonstructural-based methods are the adjoint variable technique from control theory, and the Green's function and FAST methods from physical chemistry.
Optical Second-Harmonic Generation with Surface Plasmons in Silver Films

We report the first experimental and theoretical investigation of the coupling of second-harmonic generation of light to surface plasmons in thin silver films. A model of second-harmonic generation due to polarization sources at the silver-air interface correctly predicts the observed harmonic enhancement of one and a half orders of magnitude because of excitation of the surface plasmon.
Perspective on “Equation of state calculations by fast computing machines”

An overview is given of the paper by Metropolis et al. that has formed the basis for Monte Carlo statistical mechanics simulations of atomic and molecular systems.
Infratemporal fossa approaches to the jugular foramen

The infratemporal fossa provides access to lesions of the lateral skull base, including the jugular foramen. Variants of the infratemporal fossa approaches are classified as types A, B, C, and D. The Fisch type A approach is most commonly used for glomus jugulare tumors that invade the infralabyrinthine and apical components of the temporal bone or tumors that extend intradurally. Lesions of the jugular foramen, including glomus tumors, meningiomas, and schwannomas, can be resected through this approach. The infratemporal fossa, a cavity with incomplete walls, contains the pterygoid venous plexus, the pterygoid muscles, the maxillary artery, and the mandibular division of the trigeminal nerve. Involvement of the internal carotid artery, combined with preoperative intolerance to balloon occlusion or significant intraoperative blood loss, may preclude complete resection of a glomus jugulare tumor. However, complete resection can be achieved in most cases. Injuries to the lower cranial nerves from tumor resection typically result in transient dysfunction but are expected to improve gradually.
What Is Technology? Investigating Student Conceptions about the Nature of Technology.

The science education literature clearly shows that knowledge of the nature of technology is an educational goal; however there is a lack of research on student conceptions about the nature of technology. To address this gap in the literature, this research began with a thorough review of the literature on scientific and technological literacy, the philosophy of technology, and the history of technology to develop a conceptual framework for the nature of technology. This review of the literature led to the identification of five dimensions of knowledge that completely characterise the nature of technology. Then, the conceptual framework was used to analyse data collected from an exploratory survey distributed to a small group of middle school students. All of the student responses were able to be coded using the conceptual framework; however, the results suggest that the students sampled possess some naive understandings of the nature of technology.
Conflict Reduction in Hardware Transactions Using Advisory Locks

Preliminary experience with hardware transactional memory suggests that aborts due to data conflicts are one of the principal obstacles to scale-up. To reduce the incidence of conflict, we propose an automatic, high-level mechanism that uses advisory locks to serialize (just) the portions of the transactions in which conflicting accesses occur. We demonstrate the feasibility of this mechanism, which we refer to as staggered transactions, with fully developed compiler and runtime support,running on simulated hardware. Our compiler identifies and instruments a small subset of the accesses in each transaction, which it determines, statically, are likely to constitute initial accesses to shared locations. At run time, the instrumentation acquires an advisory lock on the accessed datum, if (and only if) prior execution history suggests that the datum---or locations``downstream'' of it---are indeed a likely source of conflict. Policy to drive the decision requires one hardware feature not generally found in current commercial offerings: nontransactional loads and stores within transactions. It can also benefit from a mechanism to record the program counter at which a cache line was first accessed in a transaction. Simulation results show that staggered transactions can significantly reduce the frequency of conflict aborts and increase program performance.