cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential Effects of 1,4-Dihydropyridine Calcium Channel Blockers: Therapeutic Implications

Increasing recognition of the importance of calcium in the pathogenesis of cardiovascular disease has stimulated research into the use of calcium channel blocking agents for treatment of a variety of cardiovascular diseases. The favorable efficacy and tolerability profiles of these agents make them attractive therapeutic modalities. Clinical applications of calcium channel blockers parallel their tissue selectivity. In contrast to verapamil and diltiazem, which are roughly equipotent in their actions on the heart and vascular smooth muscle, the dihydropyridine calcium channel blockers are a group of potent peripheral vasodilator agents that exert minimal electrophysiologic effects on cardiac nodal or conduction tissue. As the first dihydropyridine available for use in the United States, nifedipine controls angina and hypertension with minimal depression of cardiac function. Additional members of this group of calcium channel blockers have been studied for a variety of indications for which they may offer advantages over current therapy. Once or twice daily dosage possible with nitrendipine and nisoldipine offers a convenient administration schedule, which encourages patient compliance in long-term therapy of hypertension. The coronary vasodilating properties of nisoldipine have led to the investigation of this agent for use in angina. Selectivity for the cerebrovascular bed makes nimodipine potentially useful in the treatment of subarachnoid hemorrhage, migraine headache, dementia, and stroke. In general, the dihydropyridine calcium channel blockers are usually well tolerated, with headache, facial flushing, palpitations, edema, nausea, anorexia, and dizziness being the more common adverse effects.
The matric computor

Abstract The Matric Computor is an analytic machine for the solution of matric problems, including differential and algebraic systems. The theoretical basis of the machine is the synthesis of an electronic admittance network whose adjustable parameters are in 1-to-1 reciprocal correspondence with matric mathematical equations. Matric entries are represented through digitally-adjusted admittances permanently interconnected through a system of entry and trace amplifiers. The prescribed mathematical functions are represented by current sources, and the dynamical voltage responses automatically generated by the network yields the solution-vector of the mathematical matric problem.
Embryonic stem cell cardiogenesis applications for cardiovascular research.

Abstract Mouse embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of the preimplantation blastocyst. These cells can be maintained in culture in an undifferentiated state, or they can be induced to differentiate in vitro into multiple cell types, including spontaneously beating cardiac myocytes. The ability to engineer these ES cells genetically, together with their noted rapid differentiation into cardiac myocytes in vitro, makes this a useful tool for the study of cardiac gene expression and function. This in vitro cardiogenesis system may be particularly advantageous for pharmacological studies focusing on discovery of cardioactive drugs and for specifying the functional alterations associated with ablated or mutated cardiac genes that result in a lethal phenotype in vivo . (Trends Cardiovasc Med 1997;7:63–68). © 1997, Elsevier Science Inc .
The symmetry of the Ion formed by stepwise loss of CO molecules in the mass spectra of p-benzoquinones

Contrary to previous suppositions, it appears that the produced by the loss of 2 CO from para-benzoquinones passes through the symmetry of not a substituted cyclobutadiene, but rather a substituted tetrahedrane, at least for inert R. The p-fluoro labeling technique is used to obtain this result.
Picosecond electron and phonon phenomena in amorphous Ge and As2Te3

Abstract Picosecond optical measurements of photoinduced absorption are used to determine hot carrier thermalization rates in a-Ge and a-Si. In a-As 2 Te 3 phonon generation and propagation has been observed and applied to determine the temperature dependence of velocity and attenuation of 30 GHz phonons in this material.
A simulation/experimental study of the thermodynamic properties of carbon dioxide on graphite

Abstract Monte Carlo (MC) computer simulations are reported for a realistic model of carbon dioxide adsorbed on the exposed graphite basal plane. Isotherms were calculated using the grand canonical MC algorithm, and energies and densities were evaluated using the canonical MC algorithm. New experimental data for this system are also presented and, together with previous data, compared with the simulations. Excellent agreement is obtained. Auxiliary properties such as the coverage dependence of the average tilt angle (relative to the surface plane) for the molecules in the monolayer were evaluated. In addition, the temperature dependence of the monolayer capacity for this system is obtained directly from the simulations. The molecular areas in the completed monolayer that were obtained from these monolayer capacities are compared with other estimates including those obtained from a BET analysis of the isotherms. It is noted that the observed change in average tilt angle with increasing coverage produces a coverage-dependent molecular area that is not taken into account in the BET or any other known theory of multilayer adsorption.
It's not what you think: A theory for understanding the lack of interest among domestic students in the engineering PhD

We live in a fast-paced world surrounded by technological advances. Engineers with advanced skills perform important functions in our society. However we know very little about how engineers consider obtaining advanced education and skills. The purpose of this study is to understand and develop a theory explaining the process domestic engineers undergo in developing an interest in obtaining a PhD in engineering. Our research was guided by the following central research question: What is the theory that explains the process of developing interest in doctoral-level engineering education for engineers? We used qualitative, grounded theory methods, to investigate the process of advanced engineering education interest. Interview data were collected from undergraduate engineering students, doctoral engineering students, engineering faculty, and engineers in industry with PhD degrees from seven institutional sites. Our theory explains that misperceptions, personal characteristics, and environmental elements are part of engineers' interest in advanced education. Engineers must be exposed to these factors and must also actively process this information to develop interest. This theory provides a framework for understanding and promoting doctoral education for engineers. Implications for educators are offered.
A Rho-dependent signaling pathway operating through myosin localizes β-actin mRNA in fibroblasts

Abstract Background: The sorting of mRNA is a determinant of cell asymmetry. The cellular signals that direct specific RNA sequences to a particular cellular compartment are unknown. In fibroblasts, β-actin mRNA has been shown to be localized toward the leading edge, where it plays a role in cell motility and asymmetry. Results: We demonstrate that a signaling pathway initiated by extracellular receptors acting through Rho GTPase and Rho-kinase regulates this spatial aspect of gene expression in fibroblasts by localizing β-actin mRNA via actomyosin interactions. Consistent with the role of Rho as an activator of myosin, we found that inhibition of myosin ATPase, myosin light chain kinase (MLCK), and the knockout of myosin II-B in mouse embryonic fibroblasts all inhibited β-actin mRNA from localizing in response to growth factors. Conclusions: We therefore conclude that the sorting of β-actin mRNA in fibroblasts requires a Rho mediated pathway operating through a myosin II-B-dependent step and postulate that polarized actin bundles direct the mRNA to the leading edge of the cell.
When Whren Won't Work: The Effects of a Diminished Capacity to Initiate a Pretextual Stop on Police Officer Behavior

The diversity of statutes regulating vehicular traffic and the near certainty that motorists will commit a violation provide police officers with abundant opportunities to establish probable cause ...
Purification and properties of acyl phosphatase from human erythrocytes

Abstract A specific acyl phosphatase was purified 900-fold from human erythrocytes by utilizing ion-exchange cellulose-column chromatography. The retention of the enzyme on a carboxymethyl-cellulose column at pH 7.5, and on a diethylaminoethyl-cellulose column at pH 9.4, indicates a basic protein. The enzyme hydrolyzes acetyl phosphate and 1,3-diphosphoglycerate, but does not act on carbamyl phosphate, nor on a variety of phosphate esters. Maximal activity of the enzyme, with acetyl phosphate as substrate, is noted at pH 5. The K m of erythrocyte acyl phosphatase is 10.3 m m , with acetyl phosphate as substrate, and 117 μ m , with 1,3-diphosphoglycerate as substrate (pH 7.50 at 37 °). Adenosine triphosphate, carbamyl phosphate, and inorganic phosphate all inhibit the enzyme competitively, with K i values of 4.4, 6.9, and 3.4 m m respectively (with acetyl phosphate as substrate). Iodoacetate and p -chloromercuri-benzoate are not inhibitory. In contrast to acyl phosphatases purified from muscle and brain, the erythrocyte acyl phosphatase is thermolabile. The possible role of erythrocyte acyl phosphatase in the regulation of metabolism is discussed.
Using video to teach future teachers to learn from teaching

Video is commonly used in teacher preparation programs. Teacher educators use video for various purposes. In this study, we describe the Learning to Learn from Mathematics Teaching project. In this project, video is used to develop pre-service teachers’ (PSTs) orientations, knowledge and skills for analyzing and reflecting on mathematics teaching in ways that generate knowledge for improvement. We discuss the ways we have used video in a course aimed at developing elementary PSTs’ abilities to learn from teaching. In addition, we report on a study that investigated PSTs’ changes in lesson analysis abilities as a result of participating in the course.
The rotating frame nuclear Overhauser effect spectroscopy experiment as an aid to determining solution structures of DNA oligomers.

Important intrinsic characteristics of the rotating frame nuclear Overhauser effect spectroscopy (ROESY) experiment were found to be advantageous in DNA solution structure determination. In a ROESY experiment, the different mechanisms of relaxation result in different signs of cross peaks, enabling a clear distinction between H2' resonances and H2" resonances of the DNA sugar backbone. This method is of particular importance in crowded spectra, for purine resonances whose H2', H2" protons typically resonate closely, as well as in conditions where line broadening makes coupling constants in a correlated spectroscopy experiment impossible to determine. By observing the signs of cross peaks in the base proton to H2', H2" sugar proton region, the ROESY spectrum can be used to distinguish A-form, B-form, and Z-form DNA.
The mutagenic footprint of low-fidelity Pol I ColE1 plasmid replication in E. coli reveals an extensive interplay between Pol I and Pol III

ColE1 plasmid replication is unidirectional and requires two DNA polymerases: DNA polymerase I (Pol I) and DNA polymerase III (Pol III). Pol I initiates leading-strand synthesis by extending an RNA primer, allowing the Pol III holoenzyme to assemble and finish replication of both strands. The goal of the present work is to study the interplay between Pol I and Pol III during ColE1 plasmid replication, to gain new insights into Pol I function in vivo. Our approach consists of using mutations generated by a low-fidelity mutant of Pol I (LF-Pol I) during replication of a ColE1 plasmid as a footprint for Pol I replication. This approach allowed mapping areas of Pol I replication on the plasmid with high resolution. In addition, we were able to approximate the strandedness of Pol I mutations throughout the plasmid, allowing us to estimate the spectrum of the LF-Pol I in vivo. Our study produced the following three mechanistic insights: (1) we identified the likely location of the polymerase switch at ~200 bp downstream of replication initiation; (2) we found evidence suggesting that Pol I can replicate both strands, supporting earlier studies indicating a functional redundancy between Pol I and Pol III (3) we found evidence pointing to a specific role of Pol I during termination of lagging-strand replication. In addition, we illustrate how our strand-specific footprinting approach can be used to dissect factors modulating Pol I fidelity in vivo.
A randomized, prospective study to evaluate the efficacy and acceptance of three bowel preparations for colonoscopy in children

A randomized, prospective study to evaluate the efficacy and acceptance of three bowel preparations for colonoscopy in children
Failure of L-carnitine to protect mice against hyperammonemia induced by ammonium acetate or urease injection.

ABSTRACT: Reports indicate that L-carnitine administration before 100% lethal dose of ammonium acetate suppresses the symptoms of ammonia toxicity and prevents death in mice. However, we have been unable to confirm this observation. The cause of discrepancy between our results and the results of others was investigated with two models of hyperammonemia in mice: 1) that induced by intraperitoneal injection of urease and 2) that induced by intraperitoneal injection of ammonium acetate. L-Carnitine administration failed to protect mice against ammonia toxicity induced by intraperitoneal injection of urease. Mortality in mice treated with L-carnitine 30 min before injection of ammonium acetate was similar to that of controls pretreated with saline. Ammonia and urea levels in plasma, liver, and brain were also similar in both groups. However, the values were significantly lower than those in mice denied either pretreatment before the ammonium acetate challenge. These results indicate that pretreatment acts to reduce blood and tissue ammonia simply by diminishing the rate of absorption of the challenge, owing to the dilution of ammonium acetate upon mixing with the contents of the peritoneal cavity. Thus, any protocol that does not compare results of a putative protective agent with those obtained with an equal volume of solvents or saline runs the risk of ascribing protective property to the agent when the protection may, in fact, have been afforded by the solvent.
A new jackknife test for homogeneity of variances

A new jackknife test is proposed to test the equality of variances in several populations. The new test is based on jackknifing one group of observations at a time, instead of one observation in each group as recommended by Miller for a two sample case, and by Layard for several samples. The proposed test is examined, and compared with other tests, in terms of power and robustness with respect to a wide variety of non-normal distributions. It is found that the new test is robust and has reasonably high power for normal as well as for non-normal observations, irrespective of the sample size. Furthermore, the proposed test is certainly superior to all other tests considered here in small to moderate size samples, and is as good as or better than the other tests in large samples, irrespective of the distribution of sampling observations.
Improving the Utility of Laryngeal Adductor Reflex Testing: A Translational Tale of Mice and Men

ObjectivesEvaluation of the laryngeal adductor reflex (LAR) entails delivering air through an endoscope positioned 1 to 2 mm from the arytenoid mucosa to elicit bilateral vocal fold (VF) closure. This short working distance limits visualization to only the ipsilateral arytenoid and results in quantification of a single LAR metric: threshold pressure that evokes the LAR. Our goal was to evolve the LAR procedure to optimize its utility in clinical practice and translational research.Study DesignProspective translational experiment.SettingAcademic institution.SubjectsYoung healthy human adults (n = 13) and 3 groups of mice: healthy, primary aging mice (n = 5), a transgenic mouse model of amyotrophic lateral sclerosis (ALS; n = 4), and young healthy controls (n = 10).MethodsThe VFs were visualized bilaterally during supramaximal air stimulation through an endoscope. Responses were analyzed to quantify 4 novel metrics: VF adduction phase duration, complete glottic closure duration, VF abduction phase duration,...
Functional significance of alternate phosphorylation in Sendai virus P protein.

Phosphorylation of the negative-sense RNA virus phosphoproteins is highly conserved, implying functional significance. Sendai virus (SV) phosphoprotein (P) is constitutively phosphorylated at S249. Abrogation of the SV P primary phosphorylation causes phosphorylation of P at alternate sites, creating a problem in determining the function of phosphorylation. We have now identified the alternate phosphorylation sites using two-dimensional phosphopeptide analysis of several deletion and point mutants of the P protein. The alternate phosphorylation sites were mutagenized to create P with (S249combo) or without (combo) primary phosphorylation. The combo protein has less than 10% phosphorylation compared with the wild-type P or S249combo. Functional analysis of the mutant proteins using a Sendai virus minigenome replication system showed that the combo P protein was as proficient in supporting minigenome replication as the wild-type P in cell cultures. These studies suggest that like the primary, the alternate phosphorylation of the P protein is also dispensable for virus replication in cell cultures. Interestingly, the ability of the multiple site mutant of P (combo mutant has eight serine residues changed to alanine residues) to support efficient virus RNA synthesis suggests that the P protein has a high flexibility at least in its sequence and perhaps also in structure.
A random intercepts-functional slopes model for flexible assessment of susceptibility in longitudinal designs.

In many biomedical investigations, a primary goal is the identification of subjects that are susceptible to a given exposure or treatment of interest. We focus on methods for addressing this question in longitudinal studies when interest focuses on relating susceptibility to a subject’s baseline or mean outcome level. In this context, we propose a random intercepts – functional slopes model that relaxes the assumption of linear association between random coefficients in existing mixed models and yields an estimate of the functional form of this relationship. We propose a penalized spline formulation for the nonparametric function that represents this relationship, and implement a fully Bayesian approach to model fitting. We investigate the frequentist performance of our method via simulation, and apply the model to data on the effects of particulate matter on coronary blood flow from an animal toxicology study. The general principles introduced here apply more broadly to settings in which interest focuses on the relationship between baseline and change over time.
A Procedure for Plotting the Sun-Path Diagram, and Shading Mask Protector

The well-known versions of sun-path diagrams and shading mask protractors that appear in the AIA`s Architectural Graphic Standards (Ramsey and Sleeper, 1970) are based on the equi-distant projections and use the shading mask protractor developed by Olgyay and Olgyay (1957). A designer using the AIA`s Graphics Standards book, or other versions of the sun-path diagram (LOF, 1974; Mazria, 1979) must select the nearest latitude, make photocopies of the appropriate sun-path diagram and shading mask protractor, and then overlay the shading mask protractor upon the diagram in the proper orientation. The outline of the shading device is then transcribed upon the shading mask, aligned at the proper orientation for the facade in which the window is being analyzed, and placed on top of the sun-path diagram to determine if a point at the base and center of a window is exposed to direct sunlight. This technical note describes the basic equations that can be used to develop a computerized construction of the shading mask protractor and sun-path diagram, and demonstrates their use with an example shading device at a northern latitude. A brief historical review of the sunpath diagrams and additional information regarding the computerization of the diagrams is provided inmore » McWatters and Haberl (1994a,b).« less
Reactive nonsexually related acute genital ulcers: review of cases evaluated at Mayo Clinic.

Background Reactive nonsexually related acute genital ulcers (RNSRAGU) occur in pubertal girls after an acute systemic infection. Objective We sought to characterize RNSRAGU by reviewing the medical records of patients with this disorder. Methods We searched our medical index database from 1997 to 2007 for RNSRAGU cases. Questionnaires were mailed to identified patients. Results The study included 10 patients; 5 responded to the questionnaire. The mean age at onset was 11.5 years. Vulvar ulcers were preceded by viral gastroenteritis (n = 3), viral upper respiratory tract infection (n = 3), streptococcal pharyngitis (n = 1), influenza (n = 1), and other nonspecific febrile illnesses (n = 2). Seven patients had oral involvement also; 6 had at least one recurrence; and 3 were hospitalized for pain control. Analgesics and topical corticosteroids were the most common treatments. Ulcerations resolved within several weeks in all patients. Limitations Retrospective study design, small study size, and 50% questionnaire response rate are limitations. Conclusions Although rare, RNSRAGU should be considered when genital ulceration follows an acute systemic illness.
Frustrated β-chloride elimination. Selective arene alkylation by α-chloronorbornene catalyzed by electrophilic metallocenium ion pairs

Single-site polymerization catalysts generated in situ via activation of Cp*MMe3 (Cp* = C5Me5; M = Ti, Zr), (CGC)MMe2 (CGC = C5Me4SiMe2NBut; M = Ti, Zr), and Cp2ZrMe2 with Ph3C+B(C6F5)4- catalyze alkylation of aromatic molecules (benzene, toluene) with α-chloronorbornene at room temperature, to regioselectively afford the 1:1 addition products exo-1-chloro-2-arylnorbornane (aryl = C6H5 (1a), C6H4CH3 (1b)) in good yields. Analogous deuterium-labeled products exo-1-chloro-2-aryl-dn-norbornane-7-d1 (aryl-dn = C6D5 (1a-d6), C6D4CD3 (1b-d8)) are obtained via catalytic arylation of α-chloronorbornene in either benzene-d6 or toluene-d8. Isolated ion-pair complexes such as (CGC)ZrMe(toluene)+B(C6F5)4- and Cp*2ThMe+B(C6F5)4- also catalyze the reaction of α-chloronorbornene in toluene-d8 to give 1b-d8 in good yields, respectively. Small quantities of the corresponding bis(1-chloronorbornyl)aromatics 2 are also obtained from preparative-scale reactions. These reactions exhibit turnover frequencies exceeding 120 h-1 ...
Consistent Dynamical Formulation of Current-Current Theories and the Validity of Current Algebra

It is shown that the usual formulations of current-current theories are not dynamically consistent, because of the occurrence of Schwinger terms. On the basis of the Poincar\'e-group algebra, an alternative and consistent formulation is constructed and generalized to allow for parity and isospin violation. It is found that, with the appropriate normalization of currents and the corresponding definitions of coupling constants, the chiral algebra of currents for time components is always satisfied in four-dimensional theories of the current-current type. In the two-dimensional case, this statement needs modification, but it is essentially valid there as well. The algebra involving spatial components is highly sensitive to the dynamics, and consequently is not identical to the free-quark-field case. In certain cases of parity violation, the usual currents which couple in the field equations do not transform as four-vectors even though the theory itself is covariant. This is somewhat analogous to radiation-gauge electrodynamics. It is found, however, that it is possible to construct new covariant currents as linear combinations of the components of the old currents which have the property that they couple covariantly into the field equation. Because of these complications, the spatial components of the covariant currents do not have a definite parity and do not transform as vectors in isospin.
Conference simulation in an English composition course

This article discusses the use of a conference format in teaching a required English composition course. The focus of the course is student research and presentation; thus, simulating a conference was a natural fit for the course's overall goals. Students worked in one of four committees: the Call for Proposals Committee, the Proposal Evaluation Committee, the Program Committee, and the Conference Facilitation Committee. The students chaired or cochaired one of these committees. Although none of the students had presented at a conference or submitted a proposal for presentation, they quickly grasped the professionalism associated with these tasks. Debriefing revealed overwhelming support for the simulated conference approach to teaching research and presentation skills.
Regionally Selective Metabolic Effects of Hypoglycemia in Brain

: Regional CNS levels of glucose reserves, glycolytic intermediates, and high-energy phosphate reserves were measured in insulin-treated, hypoglycemic rats and correlated with EEG activity. Intravenous administration of insulin to paralyzed, ventilated animals causes concomitant reduction of blood glucose levels and progressive abnormality and eventual loss of EEG activity. In all regions of brain examined, glucose and glycogen levels decrease until they are essentially depleted, and glucose-6-phosphate and fructose-1,6-biphosphate fall approximately 80%. Pyruvate levels decrease 50% in cerebral cortex and brain stem and a lesser amount in striatum, hippocampus, thalamus, and cerebellum. Lactate levels fall 50–60% in all regions except cerebellum, where no change is observed. ATP and phosphocreatine levels remain normal until the EEG is isoelectric, and then decrease in all regions except cerebellum. These results demonstrate that hypoglycemia does not have a uniform effect on brain glucose and energy metabolism, and cerebellum seems to be relatively protected.
Modeling and Experimental Diagnostics in Polymer Electrolyte Fuel Cells

This paper presents a fit between model and experiment for well-humidified polymer electrolyte fuel cells operated to maximum current density with a range of cathode gas compositions. The model considers, in detail, losses caused by: (1) interfacial kinetics at the Pt/ionomer interface, (2) gas-transport and ionic-conductivity limitations in the catalyst layer and (3) gas-transport limitations in the cathode backing. The authors` experimental data were collected with cells that utilized thin-film catalyst layers bonded directly to the membrane, and a separate catalyst-free hydrophobic backing layer. This structure allows a clearer resolution of the processes taking place in each of these distinguishable parts of the cathode. In their final comparison of model predictions with the experimental data, they stress the simultaneous fit of a family of complete polarization curves obtained for gas compositions ranging from 5 atm O{sub 2} to a mixture of 5% O{sub 2} in N{sub 2}, employing in each case the same model parameters for interfacial kinetics, catalyst-layer transport, and backing-layer transport. This approach allowed them to evaluate losses in the cathode backing and in the cathode catalyst layer, and thus identify the improvements required to enhance the performance of air cathodes in polymer electrolyte fuel cells. Finally, theymore » show that effects of graded depletion in oxygen along the gas flow channel can be accurately modeled using a uniform effective oxygen concentration in the flow channel, equal to the average of inlet and exit concentrations. This approach has enabled simplified and accurate consideration of oxygen utilization effects.« less
Cytokines and Their STATs in Cutaneous and Visceral Leishmaniasis

Cytokines play a critical role in shaping the host immune response to Leishmania infection and directing the development of protective and non-protective immunities during infection. Cytokines exert their biological activities through the activation and translocation of transcription factors into the nucleus whether they drive the expression of specific cytokine-responsive genes. Signal transducer and activator of transcription (STATs) are transcription factors which play a critical role in mediating signaling downstream of cytokine receptors and are important for shaping the host immune response during Leishmania infection. Here we discuss the signature cytokines and their associated STATs involved in the host immune response during cutaneous and visceral leishmaniasis.
Summary of discussion group onSaguinus oedipus colitis

The issue of comparison between tamarin and human colitis should not be overemphasized, as this animal model is an excellent resource for learning about the occurrence of colitis as well as carcinoma in a primate species. If one learns about husbandry problems, genetic or environmental factors, immunologic or biochemical alterations that contribute to the pathophysiology of colitis in the cotton-top tamarin, these findings will be of value in enhancing the possibility of the survival of this species. Although at initial glance there appear to be some similarities as well as differences between the human and tamarin colitis, learning about factors which cause colitis and carcinoma in this primate species may well give us important clues about factors which are related to the human disease.
Comparison of nucleotide interactions in water, proteins, and vacuum: Model for DNA polymerase fidelity

We propose a model for DNA polymerase fidelity in which free energy differences, delta delta G, between matched and mismatched nucleotides are magnified at the enzyme's active site. Both hydrogen bonding and stacking components of the interaction energy are amplified, with the most profound effect being on the magnitude of hydrogen-bonding interactions. Magnification in delta delta G values follows from the exclusion of water around base pairs in the active site cleft of the enzyme. After showing that base-pair dissociation energies calculated from hydrogen-bonding and base-stacking interactions in vacuo are greatly reduced by water, it is proposed that water removal results in a proportional restoration of these contributions to base pairing. Assuming approximately equal to 40% exclusion of surrounding water, one predicts magnified values of delta delta G sufficient to account for polymerase insertion and proofreading fidelity, thereby avoiding the need to postulate additional active site constraints in order to select or reject nucleotides.
A Relationship between Interface Trap Density and Transconductance in 6H-SiC Enhancement Mode Field Effect Transistors

An explicit analytical expression relating the interface trap densities and transconductance is derived for enhancement mode field effect transistors without any simplifying assumptions regarding the energy distribution of traps. Using this relationship, the interface trap densities were calculated from transconductance data and compared to experimental data and that provided in the literature. Our expression provides a simple and convenient method to reliably estimate interface traps densities from the readily available transconductance data provided in the pertinent literature.
Viruses and cancer causal associations

This review first considered some general problems in establishing causal links between a virus and a human cancer and offered some guidelines in the pursuit of this objective. Second, it reviewed the current causal associations for several candidate oncogenic viruses in relation to the tumors with which they are associated. These include Epstein-Barr virus in relation to Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's disease, and non-Hodgkin's lymphoma; hepatitis B and C viruses in relation to hepatocellular carcinoma; human T-cell leukemia/lymphoma virus type 1 and atypical leukemia/lymphoma; and human papilloma viruses in relation to cervical carcinoma. For some, the causal relationship is strong: hepatitis B virus with hepatocellular carcinoma, and human T-cell leukemia/lymphoma virus with adult T-cell leukemia/lymphoma. For one, the causal relationship is moderate: Epstein-Barr virus with African Burkitt's lymphoma. For others it is incomplete or inconclusive: Epstein-Barr virus with Hodgkin's disease and non-Hodgkin's lymphoma, and hepatitis C virus with hepatocellular carcinoma. Current techniques do not permit an answer for some: human papilloma virus with cervical carcinoma.
Measurement of coherent drift-wave ion-fluid velocity field when ion dynamics are stochastic.

In order to test the validity of the fluid drift approximation when ion dynamics are stochastic, the time-dependent ion-fluid velocity field in a coherent, drift-Alfven wave has been measured in Caltech’s Encore tokamak using plasma planar laser induced fluorescence. Many measured parameters of the wave are well described by the drift approximation above a threshold for stochastic ion dynamics, including the flow pattern in the single measured component of the ion-fluid velocity field. Surprisingly, the theory fails at a fundamental level by predicting flow speeds 10 times larger than those measured (‖umax‖≊10^5 cm/s).
The Continued Fraction Expansion of An Algebraic Power Series Satisfying A Quartic Equation

Abstract Some time ago Mills and Robbins (1986, J. Number Theory 23, No. 3, 388-404) conjectured a simple closed form for the continued fraction expansion of the power series solution ƒ = a 1 x −1 + a 2 x −2 + · · · to the equation ƒ 4 + ƒ 2 − x ƒ + 1 = 0 when the base field is GF(3). In this paper we prove this conjecture. Mills and Robbins also conjectured some properties of the continued fraction expansion when the base field was GF(13). We extend this conjecture by giving the continued fraction expansion in the GF(13) case explicitly.
Annotating and sketching on 3D web models

This paper reports on our progress and findings in building a Web annotation system for non-immersive 3D virtual environments. Over the last two years, we developed and tested two systems for collaborating designers to comment on virtual 3D models. Our first system, Redliner [12] lets design team members browse and leave text annotations on surfaces in three-dimensional models. Experience with Redliner, including two user evaluations in different settings, led us to develop Space Pen [13], a second annotation system with improved interaction capabilities. It goes beyond the post-it note metaphor, allowing users to draw in and on the virtual environment.
1-Aminocyclopropane Carboxylic Acid: A Potent and Selective Ligand for the Glycine Modulatory Site of the N-Methyl-d-Aspartate Receptor Complex

1-Aminocyclopropane carboxylic acid (ACPC) competitively inhibited (IC50, 38 +/- 7 nM) [3H]glycine binding to rat forebrain membranes but did not affect [3H]strychnine binding to rat brainstem/spinal cord membranes. Like glycine, ACPC enhanced 3H-labelled (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate ([3H]MK-801) binding to N-methyl-D-aspartate receptor-coupled cation channels (EC50, 135 +/- 76 nM and 206 +/- 78 nM for ACPC and glycine, respectively) but was approximately 40% less efficacious in this regard. The maximum increase in [3H]MK-801 binding produced by a combination of ACPC and glycine was not different from that elicited by glycine, but both compounds potentiated glutamate-stimulated [3H]MK-801 binding. These findings indicate that ACPC is a potent and selective ligand at the glycine modulatory site associated with the N-methyl-D-aspartate receptor complex.
Besifloxacin: A topical fluoroquinolone for the treatment of bacterial conjunctivitis

Background: Besifloxacin is a topical ophthalmic fluoroquinolone that was approved by the US Food and Drug Administration (FDA) in May 2009 for the treatment of bacterial conjunctivitis caused by susceptible bacterial strains. Objective: This article provides an overview of the pharmacology, clinical efficacy, and tolerability of ophthalmic besifloxacin when used for the treatment of bacterial conjunctivitis. Methods: Relevant reports pertaining to the pharmacology, efficacy, and tolerability of besifloxacin were identified through a search of MEDLINE (1985–December 2009) and International Pharmaceutical Abstracts (1985–December 2009) using the terms besifloxacin, BOL-303224-A, ophthalmic fluoroquinolones, and bacterial conjunctivitis. Additional publications were identified by reviewing the reference lists of identified articles and searching the FDA Web site. Results: Besifloxacin has potent in vitro inhibitory activity against most common ocular bacterial pathogens (MIC90 values generally ≤4 μg/mL), including Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae. In an ocular pharmacokinetic study in 64 healthy volunteers, the Cmax in tears (mean [SD], 610 [540] μg/mL) was reached 10 minutes after a single ocular instillation of besifloxacin; concentrations ≥1.6 μg/g of tear were sustained for at least 24 hours; and the elimination t1/2 was ~3.4 hours. In a study in 24 patients with a clinical diagnosis of bilateral bacterial conjunctivitis, systemic exposure (Cmax) after administration of besifloxacin ophthalmic suspension 3 times daily for 5 days was <0.5 ng/mL. In 2 randomized, double-masked, vehicle-controlled clinical trials, besifloxacin ophthalmic suspension was well tolerated and significantly more efficacious than vehicle in achieving clinical resolution (73.3% vs 43.1%, respectively, in one of the studies [P < 0.001]; 45.2% vs 33.0% in the other [P = 0.008]) and microbial eradication (88.3% vs 60.3% [P < 0.001] and 91.5% vs 59.7% [P < 0.001], respectively). In a randomized, double-masked, parallel-group, noninferiority trial comparing besifloxacin ophthalmic suspension 0.6% with moxifloxacin ophthalmic solution 0.5%, besifloxacin was found to be noninferior to moxifloxacin (predefined cutoff for noninferiority = −15), with no significant differences in rates of clinical resolution (58.3% and 59.4%, respectively; 95% CI, −9.48 to 7.29) or microbial eradication (93.3% and 91.1%; 95% CI, −2.44 to 6.74). Besifloxacin was generally well tolerated in these clinical trials, with the most common (≥1.5%) ocular adverse events being nonspecific conjunctivitis (2.6%), blurred vision (2.1%), bacterial conjunctivitis (1.8%), and eye pain (1.5%). The recommended dose of besifloxacin is 1 drop in the affected eye(s) 3 times daily (4–12 hours apart) for 7 days. Conclusion: Besifloxacin ophthalmic suspension 0.6% appeared to be well tolerated in the populations studied and was efficacious in the treatment of bacterial conjunctivitis caused by susceptible isolates.
Life-cycle economic analysis of distributed manufacturing with open-source 3-D printers

Abstract The recent development of open-source 3-D printers makes scaling of distributed additive-based manufacturing of high-value objects technically feasible and offers the potential for widespread proliferation of mechatronics education and participation. These self-replicating rapid prototypers (RepRaps) can manufacture approximately half of their own parts from sequential fused deposition of polymer feedstocks. RepRaps have been demonstrated for conventional prototyping and engineering, customizing scientific equipment, and appropriate technology-related manufacturing for sustainable development. However, in order for this technology to proliferate like 2-D electronic printers have, it must be economically viable for a typical household. This study reports on the life-cycle economic analysis (LCEA) of RepRap technology for an average US household. A new low-cost RepRap is described and the costs of materials and time to construct it are quantified. The economic costs of a selection of 20 open-source printable designs (representing less than 0.02% of those available), are typical of products that a household might purchase, are quantified for print time, energy, and filament consumption and compared to low and high Internet market prices for similar products without shipping costs. The results show that even making the extremely conservative assumption that the household would only use the printer to make the selected 20 products a year the avoided purchase cost savings would range from about $300 to $2000/year. Assuming the 25 h of necessary printing for the selected products is evenly distributed throughout the year these savings provide a simple payback time for the RepRap in 4 months to 2 years and provide an ROI between >200% and >40%. As both upgrades and the components that are most likely to wear out in the RepRap can be printed and thus the lifetime of the distributing manufacturing can be substantially increased the unavoidable conclusion from this study is that the RepRap is an economically attractive investment for the average US household already. It appears clear that as RepRaps improve in reliability, continue to decline in cost and both the number and assumed utility of open-source designs continues growing exponentially, open-source 3-D printers will become a mass-market mechatronic device.
Duodenal perforation following esophagogastroduodenoscopy (EGD) with cautery and epinephrine injection for peptic ulcer disease: An interesting case of nonoperative management in the medical intensive care unit (MICU)

Introduction The utilization of esophagogastroduodenoscopy (EGD) and related procedures continues to rise. Due to this increase in utilization is an inevitable rise in serious complications such as hemorrhage and perforation. One understudied and dreaded complication of EGD causing significant morbidity and mortality is duodenal perforation.
Increasing global agricultural production by reducing ozone damages via methane emission controls and ozone-resistant cultivar selection.

Meeting the projected 50% increase in global grain demand by 2030 without further environmental degradation poses a major challenge for agricultural production. Because surface ozone (O3) has a significant negative impact on crop yields, one way to increase future production is to reduce O3-induced agricultural losses. We present two strategies whereby O3 damage to crops may be reduced. We first examine the potential benefits of an O3 mitigation strategy motivated by climate change goals: gradual emission reductions of methane (CH4), an important greenhouse gas and tropospheric O3 precursor that has not yet been targeted for O3 pollution abatement. Our second strategy focuses on adapting crops to O3 exposure by selecting cultivars with demonstrated O3 resistance. We find that the CH4 reductions considered would increase global production of soybean, maize, and wheat by 23–102 Mt in 2030 – the equivalent of a ~2–8% increase in year 2000 production worth $3.5–15 billion worldwide (USD2000), increasing the cost effectiveness of this CH4 mitigation policy. Choosing crop varieties with O3 resistance (relative to median-sensitivity cultivars) could improve global agricultural production in 2030 by over 140 Mt, the equivalent of a 12% increase in 2000 production worth ~$22 billion. Benefits are dominated by improvements for wheat in South Asia, where O3-induced crop losses would otherwise be severe. Combining the two strategies generates benefits that are less than fully additive, given the nature of O3 effects on crops. Our results demonstrate the significant potential to sustainably improve global agricultural production by decreasing O3-induced reductions in crop yields.
Developmental stability across the breeding distribution of the scissor-tailed flycatcher (Tyrannus forficatus)

A central question in ecology is how individual fitness interacts with the spatial variation in population density and habitat characteristics across species’ ranges. We used fluctuating asymmetry (FA) as a measure of developmental stability (DS) in individuals of Tyrannus forficatus to estimate the suitability of sites of varying abundance and position within the species’ range. FA in the inner-tail feathers of males and females is not spatially correlated across the species’ range. FA in males increases towards the centre of the range and is not correlated with abundance. FA in females is not correlated with position in the range or abundance. Our results suggest that optimal sites are found throughout the range of the species, whereas suboptimal sites are mainly found towards the centre of the range. Additionally, our results suggest that abundance may not reflect the suitability of sites across species’ ranges.
Invited Commentary: The Epicenter of Translational Science

Epidemiology is at the center of translational science. Uniquely among biomedical disciplines, the methods and perspective of epidemiology span research from discovery to effective interventions and ultimately to their dissemination and implementation. However, shorthand designations for various phases of translational science, such as "T1, T2, T3, and T4," may be proliferating past the level of their usefulness. It is worthwhile to reflect on the actual nature of the science undertaken by epidemiologists along the continuum of discovery to application. The new challenge for epidemiology is the integration of knowledge and effective interventions into various societal settings working with allied disciplines not necessarily in the biomedical domain to ensure that these interventions have their intended effects on individual and public health.
Cuerpos in/a-propiados: carte-de-visite y las nuevas ciudadanías en la pardocracia venezolana postindependentista

During the process of the construction of the Republic, in the 19th Century, non-white sectors of Venezuelan society attempted to legitimise themselves through photographs in their cart-de-visite, with the object of ratifying their position in this ‘coffee and milk’ society. The use of such technology, as well as the introduction and acceptance of urbanity handbooks, were part of a process in which these sectors tried to ‘modernise’, reflecting related social tensions, for example, the urban-rural dichotomy or the need for ‘whitening’ themselves in the eyes of their fellow citizens. The purpose of this paper is to study the way in which photographic portraits and urbanity handbooks act in a society in which social and economic differences and distances have undergone a great upheaval since the independence process.
Reduced Uterine Perfusion Pressure During Pregnancy in the Rat Is Associated With Increases in Arterial Pressure and Changes in Renal Nitric Oxide

Abstract—A reduction in nitric oxide (NO) synthesis has been suggested to play a role in pregnancy-induced hypertension. We have recently reported that normal pregnancy in the rat is associated wit...