cssi/SciSciGPT-SciSciNet huggingface dataset:
Probing the Reaction Mechanism of Protocatechuate 3,4-Dioxygenase with X-Ray Crystallography

Protocatechuate 3,4-dioxygenase (3,4-PCD, E) catalyzes the oxidative ring cleavage of 3,4-dihydroxybenzoate (PCA) to produce β-carboxy-cis,cis-muconate. Previous results suggest that several short-lived intermediates and a conformational change are encountered during formation of the E • substrate complex followed by ternary E • PCA • O2 intermediates and product formation. In this review, the crystal structures of 3,4-PCD as isolated and complexed with 3-I,4-OH-benzoate (IHB), 3-F,4-OH-benzoate (FHB), PCA, or analogs of the ketonized PCA isomers [2-OH-isonicotinate N-oxide (INO) and 6-OH-nicotinate N-oxide (NNO)] plus CN− are compared as structural probes of the reaction pathway. The crystal structures of E • IHB and E • FHB appear to mimic the intermediate stages of PCA binding and suggest that the Fe3+-OH facilitates C4-OH proton abstraction. In contrast to the monodentate iron complexes of E • IHB and E • FHB, PCA asymmetrically chelates the iron in the anaerobic E • PCA complex. Concurrent dissociation of the axial tyrosinate (Tyr-447) generates an active site base (pK a ~ 10) capable of abstracting the PCA C3-OH proton to yield the dianionic Fe3+ • PCA complex. After its release from the iron, Tyr-447 forms the top of a small cavity adjacent to the C3-C4 bond of PCA. The ternary E • INO • CN complex mimics an E • PCA • O2 complex, and the structure shows that CN− binds to the Fe3+ in the adjacent cavity. This suggests that 3,4-PCD sequesters PCA and O2 as well as ensuing intermediates during catalysis.
An Ethically Justified Approach That Integrates Advance Directives Discussions With Care of the Patient With Cancer.

Although the frequency of advance directives discussions may be increasing, there is a need to improve the quality of these discussions. In a range of advanced medical illnesses, including cancer, ...
Women neurosurgeons around the world: a systematic review.

OBJECTIVE Gender disparities in neurosurgery have persisted even as the number of female medical students in many countries has risen. An understanding of the current gender distribution of neurosurgeons around the world and the possible factors contributing to country-specific gender disparities is an important step in improving gender equity in the field. METHODS The authors performed a systematic review of studies pertaining to women in neurosurgery. Papers listed in PubMed in the English language were collected. A modified grounded theory approach was utilized to systematically identify and code factors noted to contribute to gender disparities in neurosurgery. Statistical analysis was performed with IBM SPSS Statistics for Windows. RESULTS The authors identified 39 studies describing the density of women neurosurgeons in particular regions, 18 of which documented the proportion of practicing female neurosurgeons in a single or in multiple countries. The majority of these studies were published within the last 5 years. Eight factors contributing to gender disparity were identified, including conference representation, the proverbial glass ceiling, lifestyle, mentoring, discrimination, interest, salary, and physical burden. CONCLUSIONS The topic of women in neurosurgery has received considerable global scholarly attention. The worldwide proportion of female neurosurgeons varies by region and country. Mentorship was the most frequently cited factor contributing to noted gender differences, with lifestyle, the glass ceiling, and discrimination also frequently mentioned. Future studies are necessary to assess the influence of country-specific sociopolitical factors that push and pull individuals of all backgrounds to enter this field.
Qualified Plans and Tax Expenditures: A Reply to Professor Zelinsky

The tax treatment of qualified deferred compensation plans is generally reckoned to give rise to tax expenditures that can be justified only insofar as they contribute to our national retirement policy goals.' In an article in the North Carolina Law Review, Professor Zelinsky takes issue with this view, arguing that the present treatment of qualified plans, while imperfect, "fits comfortably into our conception of a normative income tax without appealing to expenditure-type considerations such as the encouragement of retirement savings." Professor Zelinksy terms his argument a classic defense of the status quo, but it is also an assault on the status quo, for if we need not turn to "expenditure type considerations" to justify the tax treatment of qualified plans, then we can, as he suggests, dispense with the many Internal Revenue Code provisions designed to ensure that such plans conform and contribute to our national retirement policy. I disagree with Professor Zelinsky. A tax system should not, except by design and for good reason, tax some types of income at lower effective tax rates than other types of income. Moreover, taxing retirement income at a reduced rate of tax reduces the degree of both horizontal and vertical equity in our system: horizontal equity because employees who participate in retirement plans are taxed at lower effective rates than employees who instead receive immediate cash compensation; vertical equity both because participants in such plans tend to be relatively better off economically than nonparticipants' and because the amount of benefit accruing to participants depends on their marginal tax rates. This Article will argue that Professor Zelinsky shortchanges these concerns and that we should be willing to tolerate some deficiencies (in terms of Professor Zelinsky's criteria) in a tax regime in exchange for greater neutrality between deferred and current compensation than we now have, unless we wish to use tax subsidies to encourage the formation of retirement plans that advance retirement policy goals and can design the law to do so.
Exploring Adaptive Agency I: Theory and Methods for Simulating the Evolution of Learning

Psychology construed as the scientific study of adaptive agency can include not only modelling of specific psychological adaptations in particular species, but general exploration of the adaptive processes (including evolution, learning, and computation) that build, modify, and instantiate those adaptations. Connectionist theory has concentrated on understanding the adaptive processes of learning and computation, and has assumed general-purpose learning principles as the prime constructors of psychological adaptations. But connectionism has thereby ignored the central lesson of a century of learning theory in psychology: learning mechanisms must be understood in terms of their specific adaptive functions, just like other psychological adaptations. This paper introduces the notion of psychology as the study of adaptive agency, outlines a hierarchy of adaptive processes underlying adaptive agency, and reviews the history of learning theory and the emergence of ecological and evolutionary approaches to learning. We then develop a taxonomy of adaptive functions that learning mechanisms might serve, and outline a general simulation framework for exploring those adaptive functions. Finally, we present empirical results concerning the simulated evolution of associative learning.
Status of the Chronopixel Project

Other the past few years we have developed a monolithic CMOS pixel detector design for the ILC in collaboration with the SARNOFF Corporation. The unique feature of this design is the recorded time tag for each hit, allowing assignment of the hit to a particular bunch crossing (thus the name Chronopixel). The prototype design was completed in 2007. The first set of prototype devices was fabricated in 2008. We have developed a detailed testing plan and have designed the test electronics in collaboration with SLAC. Testing is expected to start early in 2009.
Development of a burn-in time reduction algorithm using the principles of acceleration factors

To have fast EPROM manufacturing turnaround time and be cost-effective in a highly competitive market, a reduction in burn-in time is highly desirable. The author addresses this manufacturing issue. By using the principles of temperature and electric field acceleration factors and taking into consideration the prevailing device and burn-in equipment limitations, a new and simple algorithm for reducing the burn-in time has been developed. Experiments were performed on different nonvolatile memory products of various fabrication process technologies to prove the efficacy and manufacturability of this application. >
An Overview of Sarcopenic Obesity

Sarcopenic obesity (SO) refers to the copresence of sarcopenia and obesity. In this condition, a disproportion exists between the amount of lean mass relative to fat mass. Research on SO is important because the presence of both sarcopenia and obesity may have important health consequences. However, SO research has been hampered by the disparate number of definitions of SO. Various definitions of sarcopenia include ratios of appendicular mass to height(2) or body weight, measures of muscle strength, or physical function. More recent definitions incorporate all 3. Obesity is usually defined by high body mass index, but some studies have relied on percent body fat or visceral fat. Depending on the definition, the prevalence of SO ranges from 0% to 41% in older populations. The loss of lean mass and increase in fat mass with advancing age may share common etiologic pathways. Declines in physical activity can lead to poor muscle strength, lower muscle mass, and increased fat infiltration; all of which could lead to increases in fat mass. The increases in fat mass and accompanying increases in adipokines and inflammation may further adversely affect muscle quality. SO has been related to an increased risk of mobility disability, above and beyond sarcopenia, or obesity alone. Additional research is needed to further our understanding of the pathophysiology of SO and its consequences. Interventions aimed at reducing SO may improve physical function as well as reduce disability and death.
Simulation model for aircraft line maintenance planning

This paper reports results of research that developed a computerized simulation model for the aircraft line maintenance department in Continental Airlines. The original AUTOMOD model that was created duplicated the maintenance operations at Continental's major maintenance station at Newark. Modeling the day-to-day maintenance activities lead to the development of enhanced staffing models and a better understanding of resource requirements on a daily basis. This study had immediate and practical application as well as advancing an important frontier in operations research. Simulation modeling was effectively used in the estimation of technician requirements on a subshift basis. Simulation modeling generated performance measures, like technician utilization and work overflow, which could not be estimated earlier. The model gave objective justification for simple solutions like staggered shifts and part-time labor, which can meet resistance in a workforce. Simulation offers a viable tool for studying the impact of changing flight schedule on system parameters, like technician requirements. The optimization studies showed that changing the shift schedule could greatly enhance the efficiency of the existing system by spreading the workload more uniformly across shifts. Simulation, especially stochastic simulation, has advantages over mathematical modeling, especially in situations where flows have an apparent randomness in their character. Airline maintenance operations, and many maintenance operations in general, are plagued by planning difficulties because failures seem random at high levels of analysis, and/or because scheduling is tightly coupled with (and slaved to) other operations which are erstwhile irregular in their natures. Airline maintenance is one of the most important applications of maintenance in industry, as it has a profound impact on cost, customer satisfaction, and safety. This study applied stochastic modeling to flightline maintenance at an important airline, and illustrated the opportunity for improved maintenance management that only hints of its overall potential.
Innovation, Risk, and Patient Empowerment: The FDA-Mandated Withdrawal of 23andMe’s Personal Genome Service

On November 22, 2013, the US Food and Drug Administration (FDA) took the surprising step of ordering 23andMe, a genomics company, to cease marketing its flagship Personal Genome Service (PGS). The PGS is a DNA sequencing product marketed directly to consumers that claims to “help individuals and their doctors identify health areas that they need to keep an eye on.” By determining the presence of certain single-nucleotide polymorphisms, the PGS estimates risk for more than 250 diseases and health conditions by extrapolating from research studies. After initially continuing to sell its product, 23andMe heeded the FDA’s warning letter and stopped offering health-related genetic tests on December 6, 2013.
Valve proteoglycan content and glycosaminoglycan fine structure are unique to microstructure, mechanical load and age: Relevance to an age-specific tissue-engineered heart valve

This study characterized valve proteoglycan and glycosaminoglycan composition during development and aging. This knowledge is important for the development of age-specific tissue-engineered heart valves as well as treatments for age-specific valvulopathies. Aortic valves and mitral valves from first-third trimester, 6-week, 6-month and 6-year-old pigs were examined using immunohistochemistry for versican, biglycan, decorin and hyaluronan, as well as elastin and fibrillin. The fine structure of glycosaminoglycans was examined by fluorophore-assisted carbohydrate electrophoresis. Decorin expression was strongest in the 6-year-old valves, particularly in the aortic valve spongiosa. The quantity of iduronate was also highest in the 6-year-old valves. The central tensile-loading region of the anterior mitral leaflet demonstrated reduced glycosaminoglycan content, chain length and hydration and a larger fraction of 4-sulfated iduronate and lower fraction of 6-sulfation. With age, the anterior leaflet center showed a further increase in 4-sulfated iduronate and decrease in 6-sulfation. In contrast, the anterior leaflet free edge showed decreased iduronate and 4-sulfated glucuronate content with age. The young aortic valve was similar to the mitral valve free edge with a higher concentration of glycosaminoglycans and 6-rather than 4-sulfation, but aged to resemble the mitral anterior leaflet center, with an increase in 4-sulfated iduronate content and a decrease in the 6-sulfation fraction. Elastin and fibrillin often co-localized with the proteoglycans studied, but elastin co-localized most specifically with versican. In conclusion, composition and fine structure changes in valve proteoglycans and glycosaminoglycans with age are complex and distinct within valve type, histological layers and regions of different mechanical loading.
An Architecture of the Whole

This article offers a history and theory of “whole design” as it emerged through countercultural ecology, by offering a critical reading of the Whole Earth Catalog and its affiliate publications, a...
Selective ion-molecule reactions of biological lactones

The gas-phase reactions of seven biological lactones are examined in a quadrupole ion trap mass spectrometer and compared to the reactions of simple diols and lactones, which represent the active subunits of the title compounds. The evaluation of selective ion–molecule reactions of these biologically active lactones reveals structural information that is complementary to collisionally activated dissociation reactions. Depending on the nature of the substituents, the biolactones react with dimethyl ether ions by characteristic pathways. Some of the reaction products suggest that intramolecular dehydration occurs from loose proton-bound adducts due to specific functional group interactions.
Gas phase embrittlement and the nucleation of creep cavities

Etude experimentale dans des echantillons de nickel commercial revetu ou non d'un alliage metallique,recuit dans l'air ou dans de l'hydrogene soumis a des essais de rupture sous contrainte a 800 C dans l'air ou dans l'argon.Analyde des effets d'interaction possible entre les conditions de l'echantillon et l'environnement de l'essai.
On some claims related to Choquet integral risk measures

We examine two important claims by S.S. Wang and J. Treussard concerning the use of distortion functions as a universal tool in pricing financial and insurance risks, and the use of risk neutral probabilities in evaluating risks, respectively. Their claims seem reasonable only in the classical framework of Black–Scholes model, but not convincing in more extended and realistic models such as Levy processes.
Abdominal aortic aneurysm 18 years after apparent resolution of an umbilical catheter-associated aortic thrombosis

A young man was found to have an abdominal aortic aneurysm 18 years after the apparent resolution of an umbilical artery catheter-associated aortic thrombosis. This report underlines the need for long-term follow-up studies of infants with catheter-related vascular thrombosis.
Characterizing multivariate decoding models based on correlated EEG spectral features.

Objective Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated.
SU‐GG‐T‐449: Peripheral Dose Investigation of a Corpus Collosotomy by Gamma Knife, Model C

Purpose: Corpus collosotomy by Gamma Knife Radiotherapy is a treatment for medically refractoryepilepsy. Due to the long treatment duration (3–6 hours), the peripheral dose received by patients becomes a concern. In this study, peripheral doses for a posterior corpus collosotomy by Gamma Knife, Model C were investigated. Method and Materials: A Rando‐Phantom was used to measure the peripheral doses. Three types of dosimetry systems were used, which included ionization chambers,TLDs (TLD‐100 3×3×1mm chips), and OneDose™ MOSFETdosimeters. The dosimeters were placed on the surface of the Rando‐Phantom under 0.5 cm of build up at distances of 5.0, 17.5, 30.0, 42.5, 54.0, 70.0 and 84cm from the center of the treatment volume. Seven cylindrical ionization chambers with buildup caps were placed at the same distances, one chamber at each position. The leakage of the ionization chambers was measured before irradiation and recorded during treatment sessions. The phantom was irradiated using a clinical treatment plan for a posterior corpus collosotomy. The prescription dose was 130Gy (max dose), and the delivery dose was reduced to one third of the prescription dose for measurement purposes. The treatment time was 99.38 minutes. Results: The measured doses by TLD were 17.9, 9.9, 5.8, 2.9, 2.4, 1.5, and 1.1cGy for the seven positions respectively. The measured doses by ionization chambers were 16.9, 12.0, 5.2, 2.9, 2.8, 2.2, and 2.0cGy. The results obtained with the OneDose™ were not consistent due to the decay of the signal over the period of measurement. The doses measured by TLD and ionization chamber for the same position were averaged. The total doses to the measurement positions were 52.2, 33.0, 16.5, 8.7, 7.8, 5.7, and 4.8cGy, respectively, for the full prescription dose of 130Gy. Conclusion: The peripheral doses were significant, especially in the head and neck region.
Synthesis of hydroxyapatite-based powders by mechano-chemical method and their sintering

Abstract Ceramic hydroxyapatite (HA) is on the way to gaining credit as one of the most promising and diversified materials for employment in surgery, thanks to its good characteristics of biocompatibility and bioadaptability. The main and probably unique deficiency of these materials obtained by traditional methods consists in its weak mechanical resistance, that does not allow their use when even low loading is involved. To improve the mechanical properties of HA-based ceramic bodies additions are normally necessary. In this paper the authors propose a method to prepare powders and composite ceramic bodies with a matrix comprising HA. The powders are produced by the utilization of a simple and economic mechano-chemical method. The composite ceramic bodies are easily obtained by simple firing of the powders at a suitable temperature (1250 °C). The powders, after sintering, give products that show a flexural strength of more than 100 MPa in standard samples. This value is significantly higher than that usually attainable with present commercially available powders (60 MPa). The transformation in the components (HA and β-tricalcium phosphate) of the composite ceramic arises from the nature of the powders, consisting of highly defective HA. The mechano-chemical process is described together with the employed procedures specifically followed for reactive milling of starting powders. The preparation conditions of defective HA powders and properties acquired through such a method are reported. By this method an intimate mixing of β-tricalcium phosphate (β-TCP) inside the HA matrix is obtained that easily allows the preparation of ceramic bodies with reproducible properties, with no necessity for additions and mixing procedures, that could lead to inhomogeneity.
Reversal mechanisms of left ventricular remodeling: Lessons from left ventricular assist device experiments☆

The mechanical left ventricular assist device (LVAD) has become a reliable means of stabilizing the conditions of medically refractory patients with severe heart failure who are awaiting heart transplantation. At the same time, a substantial and growing body of evidence indicates that LVAD support triggers a multitude of adaptations within the failing human heart that seem to be triggered by hemodynamic unloading of the failing heart and changes in intracardiac and systemic neurohumoral activity. At the cell and tissue level, virtually every type of pathologic defect associated with failing human hearts demonstrates changes during LVAD support, and these adaptations are usually towards a less pathologic phenotype. This review summarizes the available literature concerning the phenomenology of so-called reverse remodeling. From this review it is clear that myocardial responses to LVAD support reveal the remarkable plasticity of even the most severely failing hearts. The composite literature on myocardial responses to LVAD support supports the thesis that mechanical overload is a primary factor sustaining the pathologic phenotype of the failing heart and suggests that the study of reverse remodeling provides a valuable opportunity to discover adaptive signaling pathways capable of mediating myocardial recovery.
Extensive binding of the bioflavonoid quercetin to human plasma proteins.

Although the bioflavonoids, a large group of polyphenolic natural products, exert chemopreventive effects in cardiovascular disease and cancer, there is little information about the disposition of these dietary components in man. The objective of this study was to investigate the plasma-protein binding of the most abundant bioflavonoid, quercetin, using 14C-labelled quercetin. An ultracentrifugation assay (170,000 g for 16 h at 20 degrees C) was shown to sediment plasma proteins. Binding of quercetin to normal plasma was extensive (99.1+/-0.5%, mean +/- s.d., n = 5). The unbound fraction varied as much as 6-fold, 0.3-1.8%, between subjects. This high binding was independent of quercetin concentration over the range 1.5-15 microM (0.5-5 microg mL(-1)). Human serum albumin was the primary protein responsible for the binding of quercetin in plasma (99.4+/-0.1%). Binding by alpha1-acid glycoprotein (39.2+/-0.5%) and very-low-density lipoproteins (<0.5% of total quercetin) did not make substantial contributions to overall plasma binding. The equilibrium association constant for the binding of quercetin to serum albumin was 267+/-33 x 10(3) M(-1) (n = 15). Thermodynamic data for the binding of quercetin to serum albumin indicated spontaneous, endothermic association. Displacement studies suggested that in man the 'IIA' subdomain binding site of human serum albumin was the primary binding site for quercetin. Association of quercetin with erythrocytes was significantly (P < 0.001) reduced by plasma protein binding. These data indicate poor cellular availability of quercetin because of its extensive binding to plasma proteins.
18O/16O ratios in cherts associated with the saline lake deposits of East Africa

Abstract The cherts formed from sodium silicate precursors in East African saline, alkaline lakes have δ 18 O values ranging from 31.1 to 44.1. The δ 18 O values correlate in general with lake salinities as inferred from geologic evidence, indicating that most chert was formed from its precursor in contact with lake water trapped at the time of deposition. A few of the analyzed cherts probably formed in contact with dilute meteoric water. From the widely varying δ 18 O values we conclude that precursors were transformed to chert in fluids of widely varying salinity and a Na + /a H + ratio.
Unraveling the Ubiquitome of the Human Malaria Parasite

Malaria is one of the deadliest infectious diseases worldwide. The most severe form is caused by the eukaryotic protozoan parasite Plasmodium falciparum. Recent studies have highlighted the importance of post-translational regulations for the parasite's progression throughout its life cycle, protein ubiquitylation being certainly one of the most abundant. The specificity of its components and the wide range of biological processes in which it is involved make the ubiquitylation pathway a promising source of suitable targets for anti-malarial drug development. Here, we combined immunofluorescent microscopy, biochemical assays, in silico prediction, and mass spectrometry analysis using the multidimensional protein identification technology, or MudPIT, to describe the P. falciparum ubiquitome. We found that ubiquitin conjugates are detected at every morphological stage of the parasite erythrocytic cycle. Furthermore, we detected that more than half of the parasite's proteome represents possible targets for ubiquitylation, especially proteins found to be present at the most replicative stage of the asexual cycle, the trophozoite stage. A large proportion of ubiquitin conjugates were also detected at the schizont stage, consistent with a cell activity slowdown to prepare for merozoite differentiation and invasion. Finally, for the first time in the human malaria parasite, our results strongly indicate the presence of heterologous mixed conjugations, SUMO/UB. This discovery suggests that sumoylated proteins may be regulated by ubiquitylation in P. falciparum. Altogether, our results present the first stepping stone toward a better understanding of ubiquitylation and its role(s) in the biology of the human malaria parasite.
Mega‐disasters: Is your IT battle‐ready

In the wake of the Japanese tsunami, nuclear catastrophe, and myriad other disasters, who can not be concerned about “the Big One”? Mega-disasters, once only the stuff of science fiction, now seem like a real threat. Is business prepared? Is your company really ready? A recent study suggests that companies are not even prepared for IT recovery from a small adverse event! So what steps must your company take now to become battle-ready? The authors of this article offer some answers and they examine the entire issue. © 2011 Wiley Periodicals, Inc.
Synchronous Control of a Static AC Induction Motor Drive

Conventional methods of controlling an induction motor utilize regulation of stator current and motor slip frequency in order to maintain system stability. This control strategy requires a shaft speed feedback and fast-response current regulation. An alternative method of controlling an induction motor is presented which achieves the necessary system stabilization by controlling only the motor frequency. The control inherently regulates the motor torque angle by properly adjusting the phase of the converter firing signals. By synchronizing the inverter firing pulses to the motor back electromotive force (EMF) possible adverse inverter operating modes are avoided. The concept of synchronous control eliminates the preprogrammed functional relations previously required and allows the control to adapt to any desired motor flux level. Any desired outer regulating loop can be incorporated to form a fast-response wide-range ac drive system.
A Method for Evaluating the Distribution of Power in a Committee System

In the following paper we offer a method for the a priori evaluation of the division of power among the various bodies and members of a legislature or committee system. The method is based on a technique of the mathematical theory of games, applied to what are known there as “simple games” and “weighted majority games.” We apply it here to a number of illustrative cases, including the United States Congress, and discuss some of its formal properties.The designing of the size and type of a legislative body is a process that may continue for many years, with frequent revisions and modifications aimed at reflecting changes in the social structure of the country; we may cite the role of the House of Lords in England as an example. The effect of a revision usually cannot be gauged in advance except in the roughest terms; it can easily happen that the mathematical structure of a voting system conceals a bias in power distribution unsuspected and unintended by the authors of the revision. How, for example, is one to predict the degree of protection which a proposed system affords to minority interests? Can a consistent criterion for “fair representation” be found? It is difficult even to describe the net effect of a double representation system such as is found in the U. S. Congress (i.e., by states and by population), without attempting to deduce it a priori. The method of measuring “power” which we present in this paper is intended as a first step in the attack on these problems.
Relationship of chloroquine-induced redistribution of a neutral aminopeptidase to hemoglobin accumulation in malaria parasites

To study the relationship between neutral aminopeptidase activity and hemoglobin accumulation in malaria parasites, we treated mice infected with Plasmodium berghei NYU-2 with chloroquine intraperitoneally in doses ranging from 0.3 to 3 micromol per 25 g mouse. Preparations of infected erythrocytes (normalized to represent 1000 parasites per 1000 erythrocytes) hydrolyzed 1200 nmol of leucine-p-nitroanilide per minute per milliliter of packed erythrocytes, which was 10x more than that of uninfected preparations. The activity in infected preparations was distinguished by resistance to ferriprotoporphyrin IX and puromycin and susceptibility to inhibition by ethanol and Tris. Chloroquine treatment caused the activity in unwashed membrane ghosts of infected preparations to decrease by 50% despite an increase in total activity. Concomitantly, hemoglobin in washed membrane ghosts increased. Electron microscopy revealed that the hemoglobin was retained in endocytic vesicles. Chloroquine-induced redistribution of a neutral aminopeptidase may be the cause of hemoglobin accumulation in endocytic vesicles of malaria parasites.
Direct measurements of heats of adsorption on platinum catalysts: III. Potential errors with differential scanning calorimeters

In a recent paper, the authors reported integral heats of adsorption for H/sub 2/ adsorbed on Pt dispersed on a variety of oxide supports. These values were obtained using a modified commercial differential scanning calorimeter (DSC) operated in the isothermal mode. Although the values obtained were very reproducible and fell within the wide spectrum of heats of adsorption reported in the literature, the authors served that the integral Q/sub ad/ values were higher than anticipated compared to the initial heats of adsorption measured in UHV systems. In a subsequent study of H/sub 2/ adsorption on Pd, relatively high apparent Q/sub ad/ values were again observed; however, in this system the authors had an internal calibration standard that could be utilized. When this apparent value was also found to be far too high when Ar was used as a carrier gas, it become apparent that an artifact existed which was producing erroneous energy change values. Further experiments showed that this problem was related to changes in the thermal conductivity of the gas in the sample cavity relative to the reference cavity, and it was especially severe with H/sub 2/ because of the large difference in thermal conductivity compared to Ar. Therefore,more » the authors undertook a study to clarify this problem so that others can avoid it in their studies and to develop a set of operating conditions which allow accurate heats of adsorption to be measured. In this paper the authors report corrected heats of adsorption for H/sub 2/ on the same family of Pt catalysts. 22 references.« less
Pedagogy in Common: Democratic education in the global era

In the context of the increasingly transnational organization of society, culture, and communication, this article develops a conceptualization of the global common as a basic condition of interrelation and shared experience, and describes contemporary political efforts to fully democratize this condition. The article demonstrates the implications for curriculum and teaching of this project, describing in particular the importance of fundamentally challenging the interpellation of students as subjects of the nation, and the necessity for new and radically collaborative forms of political and pedagogical authority that can more powerfully realize the imaginative potential of educators and students alike as global democratic actors. In this effort, familiar progressive educational ideas (e.g. the importance of the continuity of the curriculum, and the meaning and purpose of experimentalism) are interrogated and rearticulated. The article concludes with a discussion of the unique ways in which education can ...
Productive syntax abilities in Huntington's and Parkinson's diseases.

This study examined syntactic changes in the spoken discourse of patients with Huntington's (HD) or Parkinson's disease (PD) and explored possible relationships between their syntactic changes and concomitant cognitive and motoric symptoms. Patient and control groups participated in a conversational discourse activity and completed a battery of standardized speech and cognitive tests. The HD group used shorter and fewer grammatically complete utterances than their healthy, age-matched peers, whereas there were no significant syntactic differences between PD patients and their healthy, age-matched peers or between PD and HD patients. Productive syntax abilities in HD and PD were meaningfully related to both neuropsychological and motor speech changes. These findings indicate that patients with subcortical disease, at least those with HD, may present with language production deficits and that these deficits are most likely the product of not only motor speech limitations (i.e., dysarthria) but also underlying cognitive impairments.
Dietary chloride does not correlate with urinary thromboxane in deoxycorticosterone acetate–treated rats

Abstract Renal vascular resistance in deoxycorticosterone acetate (DOCA) salt–treated uninephrectomized rats is increased by high dietary chloride. Because DOCA salt–hypertensive rats exhibit an increased urinary excretion of thromboxane B2 (TXB2), a metabolite of thromboxane A2 (TXA2), the increased TXB2 excretion by DOCA salt–treated rats could relate to elevated dietary chloride, increased blood pressure, and/or the presence of intact renal tubules. We hypothesized that high NaCl intake, resulting in an elevated tubular chloride excretion, stimulates TXA2 production. A result of that production could be renal vasoconstriction. Baseline blood pressures were measured for 10 days, and then the rats were treated with DOCA (30 mg/kg) and fed (1) normal NaCl, (2) normal sodium with high chloride, or (3) high sodium chloride (NaCl) for 4.5 weeks. Next, the rats were uninephrectomized (1K) or unihydronephrectomized (1KHK) to yield one kidney without an intact tubular system and therefore no macula densa. Two and a half weeks later, urinary excretion of TXB2 was determined. DOCA-high NaCl-fed 1KHK or 1K rats had significant increases in systemic blood pressure to 172 ± 12 and 190 ± 5 mm Hg, respectively, compared with no significant increase in blood pressure among the other groups. Urinary TXB2 excretion was increased to 29 ± 4 pg per 24 hours per gram of body weight in all DOCA-treated 1KHK and 1K animals regardless of diet compared with DOCA-treated animals with two intact kidneys (13 ± 2 pg per 24 hours per gram of body weight). DOCA treatment in rats with one functional kidney results in the excretion of high levels of urinary TXB2 unrelated to dietary chloride load, blood pressure, or intact renal tubules. (J Lab Clin Med 2000;135:493-7)
Mineral‐Coated Polymer Microspheres for Controlled Protein Binding and Release

sized that protein-mineral interactions could be used as an alternative mechanism to create biodegradable micro-carriers for controlled protein binding and release. In particular, we employ the calcium phosphate mineral hydroxyapatite as a substrate for protein binding and release, as it has been used for over 50 years in chromatographic protein separations based on its ability to bind and release both acidic and basic proteins under particular solution conditions. Here we provide a demonstration that biodegradable polymer microspheres can be coated with an inorganic hydroxyapatite layer using biomimetic process by incubating microspheres in a modified simulated body fluid (mSBF), and that this biodegradable coating can be used as a substrate for binding and sustained release of acidic and basic proteins. Our approach involves nucleation and growth of inorganic calcium phosphate mineral coatings on the surface of organic, biodegradable polymer microspheres at near physiologic temperature and pH. This mineral growth process mimics natural biomineralization processes, [10] and results in a mineral coating that is similar in structure (platelike nanostructure) and composition (carbonated-substituted, calcium-deficient hydroxyapatitephase) tohuman bonemineral, asdetailed previouslyon macroscopic polymer films. [11,12] Specifically, protein-releasing,
Nanoindentation approach characterizing strain rate sensitivity of compressive response of asphalt concrete

This paper presents the results of a study on the use of nanoindentation test to characterize the strain rate-dependent compressive response of asphalt concrete. Nanoindentation is now widely used for characterization and testing of composite as well as single-phase materials. Using a small piece of sample, nanoindentation tests can evaluate material behavior and structure in terms of the elasticity, time-dependent response, yield strength, damage, crack advance, debonding, and fatigues. In this study, a mixture of asphalt and calcium carbonate filler powder filling the intergranular void space of the asphalt concrete was characterized in terms of strain rate sensitivity at room temperature. The indentation hardness is observed to continuously decrease during constant indentation strain rates, but the hardness response clearly indicates positive strain rate dependency when compared at the same indentation depths. Following the constant strain rate tests, indentation creep response of the asphalt–filler mixture was tested at constant load conditions. The strain rate sensitivity values characterized from double logarithmic relationships between indentation hardness and strain rate during constant strain rate and constant load tests are comparable with that determined from uniaxial compression test of cylindrical asphalt concrete samples. The observed indentation size effect on hardness value was analyzed based on an existing size effect model. The size effect in the asphalt–filler mixture, which is stronger than that defined by the model, could be attributed to a plastically graded surface of asphalt–filler sample.
Bending and Twisting of 60Sn40Pb Solder Interconnects With Creep

An exact analysis is presented for the creep deformation of a thin-walled circular solder cylinder under the actions of bending and twisting moments. Dimensionless interaction curves and charts which relate the variables, interconnect geometry, solder material properties, bending moment, twisting moment, curvature rate, and twist rate are also provided for engineering practice convenience.
A Simple Test to Determine the Efficiency of Mammary Artery Grafts during Operation

A simple test is presented to measure the efficiency of mammary artery-left anterior descending coronary artery anastomosis. While the aorta is still cross-clamped and a pronounced temperature gradient exists between the warm patient and the hypothermic heart, a thermoprobe is inserted into the apex of the heart and the flow through the mammary artery pedicle is released. Rapid warming of the cardiac apex indicates good function of the anastomosis.
GLOBAL SOLUTIONS OF NONCONCAVE HYPERBOLIC CONSERVATION LAWS WITH RELAXATION ARISING FROM TRAFFIC FLOW

Abstract We establish global solutions of nonconcave hyperbolic equations with relaxation arising from traffic flow. One of the characteristic fields of the system is neither linearly degenerate nor genuinely nonlinear. Furthermore, there is no dissipative mechanism in the relaxation system. Characteristics travel no faster than traffic. The global existence and uniqueness of the solution to the Cauchy problem are established by means of a finite difference approximation. To deal with the nonconcavity, we use a modified argument of Oleinik (Amer. Math. Soc. Translations 26 (1963) 95). It is also shown that the zero relaxation limit of the solutions exists and is the unique entropy solution of the equilibrium equation.
Localization of cysteine115 in subunit III of beef heart cytochrome c oxidase to the C side of the mitochrondrial inner membrane

Abstract Subunit III of beef heart cytochrome c oxidase (E.C.1.9.3.1) contains two cysteines, one of which, cysteine 115 , reacts with iodoacetamide and thionitrobenzoate-modified yeast cytochrome c. This cytochrome c derivative has been shown to interact with cytochrome c oxidase in the high affinity site for substrate on the C domain of the oxidase complex. This places cysteine 115 on the C side of the mitochrondrial inner membrane.
Recurrent gingival fibrous lesions: comparison of 2 cases and potential need for additional classification

Historically, the classification of localized gingival fibrous lesions has been inconsistent, leading to multiple naming schemes and confusion among pathologists. Currently, lesions are broadly grouped into localized hyperplastic lesions and true neoplasms. Although some cases are clearly defined histologically (i.e., peripheral ossifying fibroma, peripheral odontogenic fibroma), another set of "reactive" fibrous lesions exhibit overlapping histologic features including nondistinctive fibrosis and inflammation. This group can exhibit recurrence, classically related to a local stimulus. However, when local factors are absent, recurrence suggests inherent neoplastic potential. Herein, we describe 2 recurrent fibrous gingival masses, one of which reportedly recurred 3 times with no obvious inciting agent. The histologic appearance of both lesions was similarly distinctive but not well classifiable, while the immunohistochemical profile indicated divergent lesions. This highlights the need for further study of recurrent gingival fibrous lesions to better predict independent growth potential.
Vineyard's Theory of the Kinetics of Ordering and Lidiard's Consistency Conditions

Lidiard's consistency conditions are extended to the case of alloys of face centered cubic structure. By separating the jump rates into a part originating in the saddle point atoms and a part originating in the other neighbors it is shown that a Vineyard type of theory does not verify Lidiard's consistency conditions except in the limiting cases of complete order and complete disorder. Lidiards Ubereinstimmungsbedingungen werden auf den Fall von Legierungen mit kubisch-flachenzentrierter Struktur ausgedehnt. Durch Separation der Sprunggeschwindigkeiten in einen Anteil, der von Atomen in den Sattelpunkten herruhrt, und einen Anteil, der von den ubrigen Nachbarn stammt, wird gezeigt, das eine Theorie von der Vineyardschen Art nicht die Lidiardschen Ubereinstimmungsbedingungen bestatigt, auser in den Grenzfallen einer vollstandigen Ordnung und vollstandigen Nichtordnung.
Abnormal vaginal bleeding after epidural steroid injection: a paired observation cohort study

Objective The use of epidural steroid injections has increased dramatically, but knowledge of potential adverse effects is lacking. An association between steroid injection and subsequent abnormal vaginal bleeding has been suspected clinically, but evidence has been limited to anecdotal reports. Study Design Paired observational retrospective cohort study using electronic medical records from a large integrated health care system. Participants were all nonhysterectomized women who underwent epidural steroid injections in 2011. For each steroid injection, encounters for abnormal vaginal bleeding during the 60 days preceding and 60 days after the injection were compared as paired observations. For women found to have bleeding, medical records review was performed to examine menopausal status and bleeding evaluation outcomes. Results Among 8166 epidural steroid injection procedures performed on 6926 nonhysterectomized women, 201 (2.5%) procedures were followed by at least 1 outpatient visit for abnormal vaginal bleeding. Women were 2.8 times more likely to present with abnormal vaginal bleeding during the postinjection period compared with the preinjection period ( P Conclusion Epidural steroid injections are associated with subsequent abnormal vaginal bleeding for both premenopausal and postmenopausal women. Women undergoing epidural steroid injection should be advised of abnormal bleeding as a potential adverse effect and providers should be aware of this association when evaluating abnormal bleeding.
Flux flow resistivity in single crystal YBa2Cu3O7−δ

Abstract AC magnetoresistance measurements were performed on twinned single crystals of YBa2Cu3O7−δ to study the effect of dissipative flux flow motion due to Lorentz force. We report the first direct observation of Lorentz force induced flux flow resistivity in high-Tc superconductors which varies as sin2(θ) with respect to transport current-magnetic field orientation. However, the intrinsic broadening of the resistive transition in magnetic field exists even in the absence of Lorentz force and hence cannot be explained by flux flow dissipative resistivity.
Influence of Armillaria root rot on the foliar nutrients and growth of some coniferous species

Armillaria root rot induces a reduction in the concentrations of N, P, K, Mg and Na; an increase in the levels of Ca, Mn, Fe and Zn; and a decrease in the annual height growth of the diseased trees of four coniferous species. The data indicates that these changes are caused by interferences in the metabolism of the infected host.
Kinetics of Contact Catalysts and the Industrial Background

IT is a tragedy of the efforts of the student of chemical reactions at surfaces, in these closing decades of the two centuries of service to culture and civilization that the University of Pennsylvania is now celebrating, that the finest flowers of the effort should have synchronized with, and been made subservient to, the international tragedy of 1914—1918 and that which now burdens the human race. It was not mere accident that, in the decade preceding the first Great War, out of the fundamental researches of Sabatier on the capacity of nickel and other metals to induce the combination of hydrogen with unsaturated substances, there emerged the answer to the famous query of Napoleon to Frenchmen of science one hundred years earlier as to the possibility, in a blockaded country, of converting liquid fats into the solid fats necessary for the production of margarine and of soaps.