cssi/SciSciGPT-SciSciNet huggingface dataset:
Development Concepts for Mars Ascent Vehicle (MAV) Solid and Hybrid Vehicle Systems

The Advanced Concepts Office (ACO) at Marshall Space Flight Center (MSFC) has conducted ongoing studies and trades into options for both hybrid and solid vehicle systems for potential Mars Ascent Vehicle (MAV) concepts for the Jet Propulsion Laboratory (JPL). Two MAV propulsion options are being studied for use in a potential Mars Sample Retrieval (MSR) campaign. The following paper describes the current concepts for hybrid and solid propulsion vehicles for MAV as part of a potential MSR campaign, and provides an overview of the ongoing studies and trades for both hybrid and solid vehicle system concepts. Concepts and options under consideration for vehicle subsystems include reaction control system (RCS), separation, and structures will be described in terms of technology readiness level (TRL), benefit to the vehicle design, and associated risk. A hybrid propulsion system, which uses a solid fuel core and liquid oxidizer, is currently being developed by JPL with support from MSFC. This type of hybrid propulsion vehicle would allow the MAV to be more flexible at the cost of higher complexity, in contrast to the solid propulsion vehicle that is simpler, but allows less flexibility. The solid propulsion vehicle study performed by MSFC in 2018 further refined the solid propulsion system sizing as well as added definition to vehicle subsystem concepts, including the RCS, structures and configuration, interstage and separation, aerodynamics, and power/avionics. The studies were performed using an iterative concept design methodology, engaging subject matter experts from across MSFC's propulsion and vehicle systems disciplines as well as seeking trajectory feedback from analysts at JPL.
Comparative analysis of television tutorial and CAI for the teaching of typing skills to radio-teletypewriter operators

The Army is constantly assessing new technology for the purpose of increasing the effectiveness and/or the efficiency of instruction. The study presented is an evaluation of the use of a microcomputer network for the teaching of basic typing skills to teletypewriter operators. Individualized instruction delivered via the microcomputer was compared to a television tutorial method where the students practiced on real teletypewriters.
Progress and the people: histories of mass education and conceptions of Britishness, 1870–1914

This article argues that the history of mass education as it was written in Great Britain between 1870 and 1914 became an important site for debating what it meant to be British and the nature of p...
Confronting the opioid crisis with consumer health information: a look at East Tennessee

Background: Starting in the 1990s, health care providers began prescribing opioids to patients as pain relievers, believing they were safe. However, many patients became addicted to these pills. In 2017, the US Department of Health and Human Services declared a public health emergency to fight the opioid epidemic. This crisis was prevalent in East Tennessee, where many residents were prescribed opioids. Case Presentation: Librarians at an academic medical center library in East Tennessee analyzed the health information requests related to pain, mental health, and addiction over the last fifteen years. We reviewed the pattern of requests related to these topics, the counties requesting this information, and the impact that these hospital policies had on these requests. Conclusions: From 2005 to 2014, there were few requests about mental health, pain, and substance abuse. However, once the library moved into the hospital and there was an increase in awareness of opioid addiction, requests on those topics increased. Most of the requests were about pain, with the height occurring in 2017, during which year the public health emergency to fight the epidemic was declared. Additionally, 2017 was the year the hospital implemented visitor limitations for patients with infections associated with intravenous drug use, which might explain the drastic drop in substance abuse information requests in 2018. Future outreach will target counties that have a high opioid prescription rate.
A Waveform Independent Approach to Detecting Targets in Clutter with Coherent Nonidentical Pulses

This paper presents novel signal processing that enables detection of targets in clutter with waveforms that may change pulse-to-pulse. The waveform changes are unconstrained as long as they are coherent. Nonidentical pulse (NP) processing, a component of waveform diversity, has been the subject of much research due to its potentially transformative impact on technologies such as radar-embedded communications, electronic protection, MIMO radar, multi-mission radar and many others. It is well known that standard processing (i.e., matched filtering followed by moving target detector (MTD)) is not suitable for NP processing due to the loss of clutter coherence caused by Range Sidelobe Modulation (RSM). Much of the research in this area has focused on reducing the range sidelobe levels compared to the mainlobe so that the effect of RSM is less deleterious, or constructing unique filters for each pulse which result in nearly identical sidelobe behavior (thus restoring coherence). In a companion paper, the Neyman-Pearson optimum detector (OD) for range-migrating targets in the presence of clutter is derived. The current work asserts that the framework presented in the companion paper is also capable of optimally processing nonidentical pulses. A simulation of the optimum detector with nonidentical pulses (ODNP) is explored and its performance is compared with that of both standard processing with nonidentical pulses (SPNP) and the optimum detector with identical pulses (ODIP). As expected the ODNP dramatically outperforms the SPNP. Also, the performance of the OD when clutter parameters are not perfectly known is examined. It is found that the OD experiences only marginal losses due to clutter parameter estimation errors of nontrivial magnitude. Furthermore, it is shown that as the size of the processing window increases, the ODNP performance approaches that of IP processing, becoming effectively waveform independent when the interference is dominated by clutter.
The Individual Mandate Tax Penalty

In 2010, President Obama signed legislation that significantly altered the healthcare and health insurance markets in the United States. An integral part of that reform is the individual mandate, a provision that requires individuals to purchase and maintain healthcare insurance. Failure to maintain such coverage subjects an individual to a tax penalty. The Supreme Court upheld the constitutionality of that provision under Congress’s taxing power. Despite the Supreme Court upholding the individual mandate, fundamental questions remain. This Article addresses the question of whether the use of a tax penalty to encourage taxpayers to do something that the government desires is normatively a bad policy. Many commentators have contended that a tax penalty is economically equivalent to the current tax system’s use of deductions and credits to encourage behavior. This Article argues that despite some similarity, there are major differences between the two that should lead Congress to reconsider the desirability of using a tax penalty approach in the future. This Article also considers whether the use of the Internal Revenue Service to administer and enforce a penalty that has little to do with the correct baseline of income will have an adverse effect on general tax compliance. This Article explores the individual mandate tax penalty in detail. It explains the mechanics of the tax penalty provision and points out several ambiguities in the provision that will likely require clarification. It also explores whether the extent of some of the problems in the healthcare system at which the mandate is aimed have been exaggerated. The Article concludes that Congress should reexamine the pros and cons and unintended consequences of using a tax penalty to induce behavior before going down a similar road.
Advanced CT techniques for hepatic microwave ablation zone monitoring and follow-up

To evaluate utility of advanced CT techniques including HighlY constrained back-projection and dual-energy CT for intra- and post-procedure hepatic microwave ablation zone monitoring. 8 hepatic microwave ablations were performed in 4 adult swine (5 min/65 W). Low-dose routine CECT and dual-energy CT images were obtained every 1 min during ablation. Images were reconstructed ± HYPR. Image quality and dose metrics were collected. 21 MWA were performed in 4 adult swine. Immediate post-procedure CECT was performed in the arterial, portal venous, and delayed phases using both routine and DECT imaging with full-dose weight-based IV contrast dosing. An additional 16 MWA were subsequently performed in 2 adult swine. Immediate post-procedure CT was performed with half-dose IV contrast using routine and DECT. 12 patients (10 M/2F, mean age 62.4 yrs) with 14 hepatic tumors (4 HCC, 10 metastatic lesions) treated with MWA were prospectively imaged with DECT 1 month post-procedure. 120 kV equivalent images were compared to DECT [51 keV, iodine material density]. Image quality and dose metrics were collected. Gas created during MWA led to high CNR in all intraprocedural CT datasets. Optimal CNRs were noted at 4 min with CNR 6.7, 15.5,15.9, and 21.5 on LD-CECT, LD-CECT + HYPR, DECT, and DECT + HYPR, respectively (p < 0.001). Image quality scores at 4 min were 1.8, 2.8, 2.4, and 3, respectively (p < 0.001). Mean radiation dose (CTDIvol) was eightfold higher for the DECT series. For swine, post-procedural DECT images (IMD/51 keV) showed improved CNR compared to routine CT at all time points with full and with reduced dose contrast (CNR 4.6, 3.2, and 1.5, respectively, at half-contrast dose, p < 0.001). For human subjects, the 51 keV and IMD images showed higher CNRs (5.8, 4.8 vs 4.0, p < 0.001) and SNRs (3.7, 5.9 vs 2.8). Ablation zone sharpness was improved with DECT (routine 3.0 ± 0.7, DECT 3.5 ± 0.5). Diagnostic confidence was higher with DECT (routine 2.3 ± 0.9, DECT 2.6 ± 0.8). Mean DLP for DECT was 905.7 ± 606 mGy-cm, CTDIvol 37.5 ± 21.2 mGy, and effective dose 13.6 ± 9.1 mSv, slightly higher than conventional CT series. Advanced CT techniques can improve CT image quality in peri-procedural hepatic microwave ablation zone evaluation.
Sensitivity of Shear Process in Metal Cutting to the Development of Residual Stress

Machining processes are widely used for producing a component by material removal. Material is removed in the form of chips through the action of the wedge-shaped cutting tool. As the tool proceeds, the material is first elastically deformed, and then plastically deformed. The mechanism of plastic deformation in metal is dislocation movement Typical machining processes include turning, milling, drilling, shaping and grinding. It is known that the chip formation process in metal cutting is quite unique in many ways [1]. First, the process is a localized, asymmetric deformation that takes place at very large strains and exceptionally high strain rates in a small deformation zone. Typical values for strains and strain rates range 2 to 5 and 104 to 109 per second, respectively. Second, it is relatively unconstrained in that the only external constraint is the length of contact between tool and chip on the rake face of the tool. On the rake face there may be seizure as well as sliding friction. Machining introduces a large amount of plastic deformation in the workpiece material and chip. This plastic strain is nonuniform, and therefore residual stresses are induced in the workpiece surface and subsurface throughout, and slight below, the depth of plastic deformation. Thus, residual stresses are often an undesirable but unavoidable by-product of machining.
Counter inhibition between leukotoxins attenuates Staphylococcus aureus virulence

Staphylococcus aureus subverts host defences by producing a collection of virulence factors including bi-component pore-forming leukotoxins. Despite extensive sequence conservation, each leukotoxin has unique properties, including disparate cellular receptors and species specificities. How these toxins collectively influence S. aureus pathogenesis is unknown. Here we demonstrate that the leukotoxins LukSF-PV and LukED antagonize each other's cytolytic activities on leukocytes and erythrocytes by forming inactive hybrid complexes. Remarkably, LukSF-PV inhibition of LukED haemolytic activity on both human and murine erythrocytes prevents the release of nutrients required for in vitro bacterial growth. Using in vivo murine models of infection, we show that LukSF-PV negatively influences S. aureus virulence and colonization by inhibiting LukED. Thus, while S. aureus leukotoxins can certainly injure immune cells, the discovery of leukotoxin antagonism suggests that they may also play a role in reducing S. aureus virulence and maintaining infection without killing the host.
Challenges of high supply currents during VLSI test

Very high power supply currents required during test of advanced VLSI parts pose problems for both the ATE power supply and the interconnect to the DUT. Power supply design, inductance, resistance, filter capacitance and sense points all become critical. Design of the DUT interface board requires careful attention to detail.
Maternal behavior following rehabilitation of rats with intergenerational malnutrition. 1. Persistent changes in lactation-related behaviors.

Department of Child Psychiatry, Boston UniversityMedical Center, Boston, MA 02118ABSTRACT Female rats rehabilitated for one or two generations on anadequate level of dietary protein following a history of intergenerational malnutrition were studied during the postnatal suckling period. Norecovery occurredafter two generations of dietary rehabilitation for most measures of maternal behavior including active nursing, passive nursing, pup-oriented behavior, timespent in the nest or time spent in contact with the young. In contrast, nest'qualityimproved to normal levels after rehabilitation. In addition, growth ofpups born tofemales rehabilitated for one generation was similar to growth ofcontrol pups, andin the case of mothers rehabilitated for two generations, growth of offspringexceeded that of the control pups. These results demonstrate variable sensitivityof different maternal behaviors to rehabilitation following a history of inter-generational malnutrition, with lack of normalization ofa considerable number ofmaternal behaviors. Consequently, some of these abnormalities in maternal behavior may result in persistent abnormalities in the behavior of offspring overseveral generations. J. Nutr. Ill: 1330-1336, 1981.INDEXING KEY WORDSgrowth â€¢nursing behaviormalnutrition maternal behaviorWe have recently demonstrated persistent behavioral deficits produced byintergenerational malnutrition which arenot fully reversed after several generations of rehabilitation with an adequate protein diet. Nursling pups rehabilitated for up to three generationshad significant performance deficits on atest of home-orienting behavior, despitecomplete physical recovery (1). This testdemonstrated a reduction in the pups'ability to return to the nest, similar tothe reduction in performance present inmalnourished pups who had not been rehabilitated. This finding was not an expression of impaired activity, which returned to normal levels within one generation of rehabilitation. Furthermore, aftertwo generations of rehabilitation, thesame animals only partially recoveredperformance on a test of visual discrimination learning administered at 3 months ofage (2).The quality of behavioral performancelater in life is known to be associated withearly litter conditions (3). Consequently,deficits observed in these animals may bedue to deficits in the mother-pup relationship, as well as to the direct effects ofnutritional status on brain growth anddevelopment. Maternal behavior as a factor receives support from the fact thatlactating females malnourished at thetime of observation show behavioral abnormalities regardless of the method bywhich malnutrition is produced (4, 5).There is, however, no published evidenceon the degree of success of rehabilitation after malnutrition in restoring normalmaternal behavior. In the current study,
Silicate regulation of new production in the equatorial Pacific upwelling

Surface waters of the eastern equatorial Pacific Ocean present the enigma of apparently high plant-nutrient concentrations but low phytoplankton biomass and productivity1. One explanation for this ‘high-nitrate, low-chlorophyll’ (HNLC) phenomenon has been that growth is limited by iron availability2,3. Here we use field data and a simple silicon-cycle model4 to investigate the HNLC condition for the upwelling zone of this ocean region. Measured silicate concentrations in surface waters are low and largely invariant with time, and set the upper limit on the total possible biological utilization of dissolved inorganic carbon. Chemical and biological data from surface waters indicate that diatoms—silica-shelled phytoplankton—carry out all the ‘new production’ (nitrate uptake)5. Smaller phytoplankton (picoplankton) accomplish most of the total primary production, largely fuelled by nitrogen regenerated in reduced forms as a result of grazing by zooplankton. The model predicts values of new and export production (the production exported to below the euphotic zone) that compare well with measured values6. New and export production are in balance for biogenic silica, whereas new production exceeds export for nitrogen. The HNLC condition in the upwelling zone can therefore be understood to be due to a chemostat-like regulation of nitrate uptake by upwelled silicate supply to diatoms: ‘low-silicate HNLC’. These results are not inconsistent with observations of iron-fertilized diatom growth during in situ experiments in ‘low-iron HNLC’ waters outside this upwelling zone2,3, but reflect the role of different supply rates of iron and silicate in determining the nature of the HNLC condition.
Nutrition in Public Health: Principles, Policies, and Practice

Nutrition in Public Health Preventing Disease or Promoting Health? Nutritional Epidemiology Diet-Related Chronic Disease: Disparities and Programs to Reduce Them Weight Control: Challenges and Solutions Special Populations Cultural Competency Food and Nutrition Policies Food and Nutrition Guidance Food and Nutrition Assessment of the Community Promoting Food Security Social Marketing and Other Mass Communication Techniques Food Safety and Defense Grants to Support Initiatives in Public Health Nutrition
Sex on the Brain

The Mating Mind . How Sexual Choice Shaped the Evolution of Human Nature. Geoffrey F. Miller. Doubleday, New York, 2000. 509 pp. $27.50, C$42.95. ISBN 0-385-49516-1. Heinemann, London, 2000. 528 pp. £20.00. ISBN 0-434-00741-2. Miller argues that the evolution of the human brain was driven by the same factor responsible for the peacock's tail: the need to attract and win sexual partners
Use of genetic models of idiopathic hypogonadotrophic hypogonadism in mice and men to understand the mechanisms of disease

Mutations in the genes encoding the neuropeptides kisspeptin and neurokinin B, as well as their receptors, are associated with gonadotrophin-releasing hormone (GnRH) deficiency and a failure to initiate and/or progress through puberty. Although the total number of patients studied to date is small, mutations in the kisspeptin pathway appear to result in lifelong GnRH deficiency. Mice with mutations in kisspeptin and the kisspeptin receptor, Kiss1(-/-) and Kiss1r(-/-), respectively, appear to be phenocopies of the human with abnormal sexual maturation and infertility. In contrast, mutations in the neurokinin B pathway lead to a more variable adult reproductive phenotype, with a subset of hypogonadotrophic individuals demonstrating paradoxical recovery of reproductive function later in life. While 'reversal' remains poorly understood, the ability to recover reproductive function indicates that neurokinin B may play different roles in the initiation of sexual maturation compared with the maintenance of adult reproductive function. Mice with mutations in the gene encoding the neurokinin B receptor, Tacr3, have abnormal oestrous cycles and subfertility but, similar to their human counterparts, appear less severely affected than mice with kisspeptin deficiency. Further investigations into the interaction between the kisspeptin and neurokinin B pathways will reveal key insights into how GnRH neuronal modulation occurs at puberty and throughout reproductive life.
Human feet tracking guided by locomotion model

Following a person is a fundamental requirement for human-robot interaction. In this paper we propose a novel tracking approach for robust human feet tracking which integrates human locomotion into tracking algorithms. The vertical displacement between the two feet is analyzed and we observe that this displacement during the walking cycle is close to a modulated cosine waveform. Based on this, we propose an adaptive model for the human walking pattern. We divide the motion of the human feet into local motion and global motion. The local motion is modeled by a modified cosine wave that updates along time. Global motion is estimated by the continuity between successive frames. This model is combined with particle filtering to guide the searching of the feet. A 2D Gaussian mask is generated according to the predicted position estimated by the motion model and used to modify the weight of the particles. Experiments are implemented in several human walking videos and the algorithm is evaluated against the generic particle filtering method. Results show that the feet can be tracked successfully with significant improvements compared to the generic particle filtering method.
Freud, the Reluctant Philosopher

Freud, the Reluctant Philosopher by Alfred I. Tauber Princeton University Press , Princeton, NJ , 2010 ; 318 pp; $24.95 Many commentators offer a passing nod to Freud’s interest in philosophy, duti...
Synthesis and characterization of a high spin d6 Fe(II) complex with the tridentate ligand dipyrido(2,3-a:3′,2′-j)phenazine (dpop′)

Abstract A new bis -( N -tridentate) Fe(II) complex [Fe(dpop ′ ) 2 ](PF 6 ) 2 (dpop ′ =dipyrido(2,3- a :3 ′ ,2 ′ - j )phenazine) was prepared and studied. The magnetic moment of the solid was determined as μ =5.2–4.9 BM and in CH 3 CN solution as μ =4.9 BM and indicate the high spin Fe(II) state. The electronic absorption spectrum displays a broad weak absorption MLCT transition at 602 nm ( e =3.8×10 3 M −1 cm −1 ), consistent with CT absorptions of other Fe(II) HS complexes. The cyclic voltammogram of the complex shows an irreversible Fe 2+/3+ oxidation at +1.55 V and two dpop ′0/−1 centered reductions at −0.20 and −0.59 V versus Ag/AgCl.
A Special Multi-Pulse Converter with Small Active Power Filter

The article presents the principle of operation and results of laboratory and simulation tests of a multi-pulse power network converter systems with direct-current voltage output, mating with shunt active power filter (APF). The discussed systems allow for significant reduction of undesirable higher harmonics in the power network current, including the elimination of harmonics of an order of 23 and 25, especially in the local power network supply conditions. The multi-pulse nature of operation of the system is obtained using set of coupled three-phase power network reactors (CTR).
An analysis of particle track effects on solid mammalian tissues

Relative biological effectiveness (RBE) and quality factor (Q) at extreme values of linear energy transfer (LET) have been determined on the basis of experiments with single-cell systems and specific tissue responses. In typical single-cell systems, each heavy particle (Ar or Fe) passes through a single cell or no cell. In experiments on animal tissues, however, each heavy particle passes through several cells, and the LET can exceed 200 keV micrometers-1 in every cell. In most laboratory animal tissue systems, however, only a small portion of the hit cells are capable of expressing the end-point being measured, such as cell killing, mutation or carcinogenesis. The following question was therefore addressed: do RBEs and Q factors derived from single-cell experiments properly account for the damage at high LET when multiple cells are hit by HZE tracks? A review is offered in which measured radiation effects and known tissue properties are combined to estimate on the one hand, the number of cells at risk, p3n, per track, where n is the number of cells per track based on tissue and organ geometry, and p3 is the probability that a cell in the track is capable of expressing the experimental end-point. On the other hand, the tissue and single-cell responses are compared by determining the ratio RBE in tissue/RBE in corresponding single cells. Experimental data from the literature indicate that tissue RBEs at very high LET (Fe and Ar ions) are higher than corresponding single-cell RBEs, especially in tissues in which p3n is high.
The Attentional Costs of Interrupting Task Performance at Various Stages

The visual occlusion technique has received considerable attention in recent years as a method for measuring the interruptible aspects of in-vehicle information system (IVIS) task performance. Beca...
Standardization of ground and flight data interfaces for spaceflight instrument support

Instrument Ground Support Equipment (IGSE) will be used for instrument support on both the ground and flight phases of the Gamma-Ray Observatory (GRO) program. These mission phases include instrument development, observatory integration and test, prelaunch processing at the Kennedy Space Center (KSC) end-to-end testing, and in-orbit operations. The data interfaces between each of the IGSE's and the ground and flight systems have been evaluated to determine whether they should be standardized, and, if so, to what standard and why? Standardization, in this concept, provides for the capability to use the same IGSE without change as these systems are used throughout the various phases of the mission listed above. This evaluation has shown that there is a cost savings associated with standardization. In addition, several other intrinsic benefits have been identified. Based on this evaluation, the international standard protocol X.25 was selected to interface each of the IGSE's to the ground and flight systems.
Development of a 3D QSPR model for adsorption of aromatic compounds by carbon nanotubes: comparison of multiple linear regression, artificial neural network and support vector machine

Adsorption coefficients of 39 aromatic compounds onto multi-walled carbon nanotubes have been compiled. To understand the relationship between adsorption coefficients and physicochemical properties of aromatic compounds, a 3D quantitative structure–property relationship (QSPR) model was developed by the utilization of 3D molecular structures of 39 aromatic compounds. A Monte Carlo computational algorithm was utilized to generate 3D molecular descriptors and physicochemical properties for the QSPR model. Of the physicochemical descriptors: log Kow, number of nitrogen and oxygen atoms and number of atoms in rings present positive correlation. However, the dipole moment of the molecule and number of hydrogen bonds accepted by the solute present negative correlations. In the model development process, three different learning approaches, multiple linear regression (MLR), artificial neural network (ANN) and support vector machine (SVM), were used. The validation results showed that SVM- and ANN-based models resulted in a better agreement between predicted and measured values, with the coefficient of determination (R2) of 0.8317 and 0.7829, than the MLR-based model with R2 of 0.5093.
Dynamics of Transport Processes in the Upper Troposphere

A number of key problems in atmospheric chemistry are shaped by the strength and character of the various mechanisms acting to move and mix air in the upper troposphere. These transport processes are examined from a mechanistic perspective, with primary emphasis on the tropopause and middle-troposphere regions in the extratropics. The roles of vertical and horizontal transport “barriers” are explored, including the processes by which such barriers are created and are overcome. These transport considerations lead to a hypothesis concerning the processes that shape the tropopause itself. Some perspectives are offered on the still immature subject of transport in the upper troposphere of the tropics.
Copper and zinc abundances in chondritic meteorites.

Copper and zinc abundances in carbonaceous, enstatite and ordinary chondrite determined by neutron activation techniques
Consequences of unlocking the cardiac myosin molecule in human myocarditis and cardiomyopathies

Myocarditis, often initiated by viral infection, may progress to autoimmune inflammatory heart disease, dilated cardiomyopathy and heart failure. Although cardiac myosin is a dominant autoantigen in animal models of myocarditis and is released from the heart during viral myocarditis, the characterization, role and significance of anti-cardiac myosin autoantibodies is poorly defined. In our study, we define the human cardiac myosin epitopes in human myocarditis and cardiomyopathies and establish a mechanism to explain how anti-cardiac myosin autoantibodies may contribute to heart disease. We show that autoantibodies to cardiac myosin in sera from myocarditis and dilated cardiomyopathies in humans targeted primarily epitopes in the S2 hinge region of cardiac myosin. In addition, anti-cardiac myosin antibodies in sera or purified IgG from myocarditis and cardiomyopathy targeted the beta-adrenergic receptor and induced antibody-mediated cAMP-dependent protein kinase A (PKA) cell signaling activity in heart ce...
High efficiency polyethylene glycol diacrylate monoliths for reversed-phase capillary liquid chromatography of small molecules.

Abstract Highly cross-linked monolithic networks (i.e., polyethylene glycol diacrylate, PEGDA) synthesized from monomers containing varying ethylene oxide chain lengths were fabricated inside fused silica capillary columns for use in liquid chromatography (LC) of small molecules. Tergitol was used as a surfactant porogen in combination with other typical organic liquid porogens. Column performance was correlated with quantitative descriptors of the physical/chemical properties of the monomers and porogens using a statistical model. Solubility and viscosity values of the components were identified as important predictors of monolith morphology and efficiency. The chromatographic retention mechanism was determined to be principally reversed-phase (RP) with additional hydrogen bonding between the polar groups of the analytes and the ethylene oxide groups embedded in the monolith structure. The fabricated monolithic columns were evaluated under RPLC conditions using phenols, hydroxy benzoic acids, and alkyl parabens as test compounds. Isocratic elution of hydroxy benzoic acids at a linear velocity of 0.04 cm/s using a PEGDA-700 monolith gave chromatographic peaks with little tailing (i.e., tailing factor
Forces on a large cylindrical bubble in an unsteady rotational flow

The full Navier–Stokes equations were employed with a single-fluid model and a front tracking scheme to study a large cylindrical bubble in a free shear layer. A general formulation based on work by Auton et al. of the hydrodynamic forces on a finite Reynolds number large bubble in an unsteady, nonuniform and rotational flow was then used to investigate the effects of nonlinear spatial and temporal gradients on dispersion. The resulting bubble dispersion in the full Navier–Stokes solution significantly differ from that by a conventional bubble dynamic equation based on linear spatial gradients and quasi-steady flow. This was due to the adjunct forces not accounted for by such a formulation, which are related to regions of high nonuniformity and unsteadiness. These adjunct forces in the drag/lift direction were correlated with rapid variations of relative bubble velocity and high gradients of the liquid velocity.
An Expected-Utility Model of Electoral Competition

The idea that candidates are interested not solely in the attainment of office, but also care about the policy to which they pledge themselves, is natural and appealing. Indeed, it was not until such works as Davis, Hinich and Ordeshook's "An expository development of a mathematical model of the electoral process" (Davis et al., 1970) and Mayhew's Congress: The Electoral Connection (Mayhew, 1974) employed the assumption that Congressmen were "single-minded seekers of re-election" that the usefulness of an approach which ignored the personal policy preferences of Congressmen became apparent. Now, of course, the assumption of policy-indifferent candidates is used widely in formal models of the electoral process. While the specific behavior of candidates may vary from maximizing votes (e.g., Kramer, 1977), to maximizing plurality (e.g., Hinich and Ordeshook, 1970), to choosing according to a uniform distribution from amongst the winning strategies (Ferejohn et al., 1981), and so on, the basic assumption that candidates care chiefly about winning elections is generally retained. There have, however, been a few attempts to reinstate policy motivations for candidates (Wittman, 1973, 1977; Petry, 1982). Indeed, these attempts do more than reinstate an element of policy concern; they posit that candidates care not at all about which candidate wins but only about which policy wins (i.e., is advocated by the winning candidate). In the models both of Wittman and of Petry, a candidate chooses a position x (when his opponent is at y) which will maximize his expected utility--the probability of his winning times the utility of x plus the probability of his opponent winning times the utility of y. Since both use the traditional assumption that voters have ideal points and vote with certainty for the candidate closer to this ideal point, maximizing expected utility given y is equivalent to maximizing utility by choice of x subject to the constraint that x be in the set of points which defeat y by majority vote. Unfortunately, this maximization problem does not necessarily have a solution, since the set of points defeating a given point
Comparative Bacterial Proteomics: Analysis of the Core Genome Concept

While comparative bacterial genomic studies commonly predict a set of genes indicative of common ancestry, experimental validation of the existence of this core genome requires extensive measurement and is typically not undertaken. Enabled by an extensive proteome database developed over six years, we have experimentally verified the expression of proteins predicted from genomic ortholog comparisons among 17 environmental and pathogenic bacteria. More exclusive relationships were observed among the expressed protein content of phenotypically related bacteria, which is indicative of the specific lifestyles associated with these organisms. Although genomic studies can establish relative orthologous relationships among a set of bacteria and propose a set of ancestral genes, our proteomics study establishes expressed lifestyle differences among conserved genes and proposes a set of expressed ancestral traits.
Spectroscopic characterization of surface formates produced via reaction of HCOOH and HCOOCH3 on the (0001) surface of zinc oxide

Abstract The formation and decomposition of surface formate species formed via reactions of HCOOH and HCOOCH3 on the (0001)-Zn polar surface of ZnO were studied using temperature programmed desorption and X-ray and ultraviolet photoelectron spectroscopies. Methyl formate underwent nucleophilic attack by lattice oxygen on the (0001)-Zn polar surface which resulted in the formation of surface formate and methoxy species. The surface methoxy species were subsequently oxidized to surface formate. Adsorbed formate species decomposed during TPD experiments at 575 K producing CO, CO2, and H2. Ultraviolet photoelectron spectra of adsorbed formate species on the (0001)-Zn surface showed greater perturbation of the low-lying valence energy levels than formates adsorbed on noble metal surfaces. This result is consistent with previous studies of the electronic structure of adsorbed species on ZnO surfaces.
Monovision in LASIK.

Purpose To evaluate the preoperative characteristics and postoperative outcomes of presbyopic and prepresbyopic patients selecting monovision correction by LASIK. Design Retrospective observational case series. Participants One hundred seventy-two sequentially treated myopic and hyperopic patients, 45 years or older, who sought LASIK vision correction with the goal of monovision. Methods Patients treated with monovision correction by LASIK were measured and categorized. All treatments were conducted using conventional (nonwavefront) technology. Main Outcome Measures Acuity, refractive and functional success of monovision correction based on postoperative manifest refraction relative to target correction, and patient enhancement rate. Results Of 284 consecutively treated LASIK patients 45 years or older, 188 (67%) chose to be corrected for monovision and 96 (34%) chose bilateral distance correction. Of the patients seeking laser vision correction, women (60%) outnumbered men (40%), and women selected monovision slightly more often than men (66.9% vs. 60.5%, P = 0.14). A majority of patients (85%) chose their dominant eye to be corrected for distance. Patients who selected their dominant eye for near vision correction had similar acceptance and refractive success rates. Hyperopic patients achieved results comparable to those of myopic patients. Of the 172 patients treated with monovision correction, only 7% chose to forego monovision and subsequently enhance the near eye to distance vision. However, 27.9% of monovision patients underwent subsequent enhancement of their distance vision eye. Conclusions LASIK monovision correction represents a viable and increasingly popular method of correcting presbyopic and prepresbyopic patients considering refractive surgery. Crossed monovision may be applied successfully to appropriately chosen patients. The distance vision eye in the monovision patient may have a lower tolerance for residual refractive error and require a higher rate of enhancements than a standard laser vision correction patient.
Pathophysiological role of calpain in experimental demyelination.

Calcium-activated neutral proteinase (calpain) has been extensively studied over the past three decades such that many enzymatic and structural properties of this enzyme are well understood. However, the pathophysiological roles of calpain remain poorly defined. In addition to recent studies delineating a role for calpain in various pathological conditions, this proteinase has been implicated in the degradation of myelin proteins in autoimmune demyelinating diseases such as multiple sclerosis and experimental allergic encephalomyelitis (EAE). In EAE, calpain translational expression is significantly increased in activated glial/inflammatory cells that participate in myelinolysis while calpain substrates (axonal and myelin proteins) are lost. Thus, since all major myelin proteins are calpain substrates, early studies suggest calpain may play an important role in demyelination of the central nervous system. J. Neurosci. Res. 55:533–541, 1999. © 1999 Wiley-Liss, Inc.
WISC-IV Profile in High-Functioning Autism Spectrum Disorders: Impaired Processing Speed is Associated with Increased Autism Communication Symptoms and Decreased Adaptive Communication Abilities

Changes in the Wechsler Intelligence Scales for Children-IV (WISC-IV) may affect the IQ profile characteristic of autism spectrum disorders (ASD). Moreover, the association of particular component cognitive abilities (unlike overall IQ) with symptomatology and adaptive functioning in ASD remains unclear. This archival study characterizes the WISC-IV IQ profile among 56 high-functioning (IQ > 70) children with ASD and correlates WISC-IV performance with ASD and ADHD symptomatology and adaptive functioning. The ASD WISC-IV profile included strengths on Matrix Reasoning and Similarities, weaknesses on Comprehension (which correlated negatively with social symptoms) and the subtests comprising the Processing Speed Index (Coding, Symbol Search). Processing speed task performance correlated negatively with communication symptoms and positively with communication abilities, indicating its importance to functional outcomes in ASD.
Exponential order statistic models of software reliability growth

Failure times of a software reliability growth process are modeled as order statistics of independent, nonidentically distributed exponential random variables. The Jelinsky-Moranda, Goel-Okumoto, Littlewood, Musa-Okumoto logarithmic, and power law models are all special cases of exponential order statistic models, but there are many additional examples as well. Various characterizations, properties, and examples of this class of models are developed and presented.
The chemistry of methyl iodide on Mo(100) : formation and reaction of adsorbed methyl species

The adsorption of methyl iodide is studied on Mo(100) where ultraviolet photoelectron spectroscopy shows that the methyl iodide thermally decomposes to form methyl species on warming to ∼ 200 K. This self-hydrogenates to yield methane which desorbs at ∼ 230 K and predosing the surface with deuterium forms essentially only CH3D indicating that the methyl species reacts with adsorbed hydrogen and that there is little HD exchange. This methane desorption temperature is identical to that found when methylene species are grafted on the surface by adsorbing methylene iodide indicating that methyl hydrogenation to methane is the rate-limiting step. This temperature is substantially lower than that at which methyl and methylene species yield methane from clean and oxygen-covered Mo(100) when formed by other routes. It is proposed that this is due to the effect of relatively large iodine atoms adsorbed in the four-fold hollow site affecting neighboring (either atop or bridge) sites.
Glycocalyx of Bacteroides and Staphylococcus. Role in mixed infections

Resume Le glycocalyx de la cellule bacterienne est compose d'exopolysaccharides et comprend la capsule bacterienne et le slime produit en dehors de la capsule. Le slime peut rester attache a la cellule bacterienne ou se detacher dans le tissu environnant. Le glycocalyx est important par l'attachement des bacteries aux tissus et aux corps etrangers. La croissance des bacteries dans la nature produit des glycocalyx extensifs qui interposent leur attachement aux surfaces et la formation de microcolonies et, eventuellement, les biofilms epais. Les biofilms sont composes d'un grand nombre de cellules bacteriennes et du glycocalyx visqueux qui est produit par les bacteries. Les biofilms s'attachent aux surfaces plastiques, aux tissus tels que les surfaces osseuses et aux appareils de prothese.
On the Mechanism of Multiple Lysine Methylation by the Human Mixed Lineage Leukemia Protein-1 (MLL1) Core Complex

Transcription in eukaryotic genomes depends on enzymes that regulate the degree of histone H3 lysine 4 (H3K4) methylation. The mixed lineage leukemia protein-1 (MLL1) is a member of the SET1 family of H3K4 methyltransferases and is frequently rearranged in acute leukemias. Despite sequence comparisons that predict that SET1 family enzymes should only monomethylate their substrates, mono-, di-, and trimethylation of H3K4 has been attributed to SET1 family complexes in vivo and in vitro. To better understand this paradox, we have biochemically reconstituted and characterized a five-component 200-kDa MLL1 core complex containing human MLL1, WDR5, RbBP5, Ash2L, and DPY-30. We demonstrate that the isolated MLL1 SET domain is a slow monomethyltransferase and that tyrosine 3942 of MLL1 prevents di- and trimethylation of H3K4. In contrast, a complex containing the MLL1 SET domain, WDR5, RbBP5, Ash2L, and DPY-30, displays a marked ∼600-fold increase in enzymatic activity but only to the dimethyl form of H3K4. Single turnover kinetic experiments reveal that the reaction leading to H3K4 dimethylation involves the transient accumulation of a monomethylated species, suggesting that the MLL1 core complex uses a non-processive mechanism to catalyze multiple lysine methylation. We have also discovered that the non-SET domain components of the MLL1 core complex possess a previously unrecognized methyltransferase activity that catalyzes H3K4 dimethylation within the MLL1 core complex. Our results suggest that the mechanism of multiple lysine methylation by the MLL1 core complex involves the sequential addition of two methyl groups at two distinct active sites within the complex.
First-Order Discrete Phase-Locked Loop with Applications to Demodulation of Angle-Modulated Carrier

In this paper, a first-order discrete phase-locked loop that tracks the phase of an incoming analog signal at discrete instants of time occurring once per cycle of the carrier is developed. The functional loop components and the operation of the loop are described in detail. The loop model is developed for both the deterministic and noisy case by a nonlinear coupled difference equation with perturbed (or deviating) arguments. The tracking performance for the inputs of the phase step, the phase ramp, and the sinusoidally modulated carrier is determined and the locking conditions for these input transients are derived. Conceptual designs using this first-order digital loop have been given for the demodulation of phase- and frequency-modulated signals.
Single molecule tracking on supported membranes with arrays of optical nanoantennas.

Coupling of the localized surface plasmons between two closely apposed gold nanoparticles (nanoantenna) can cause strong enhancements of fluorescence or Raman signal intensity from molecules in the plasmonic “hot-spot”. Harnessing these properties for practical applications is challenging due to the need to fabricate gold particle arrays with well-defined nanometer spacing and a means of delivering functional molecules to the hot-spot. We report fabrication of billions of plasmon-coupled nanostructures on a single substrate by a combination of colloid lithography and plasma processing. Controlled spacing of the nanoantenna gaps is achieved by taking advantage of the fact that polystyrene particles melt together at their contact point during plasma processing. The resulting polymer thread shadows a gap of well-defined spacing between each pair of gold triangles in the final array. Confocal surface-enhanced Raman spectroscopy imaging confirms the array is functionally uniform. Furthermore, a fully intact su...
More than Just an Internet Hype: Added Value with Spatial-Enabled Enterprise Applications

Just a few years ago spatial data was only relevant for surveying and mapping authorities (land registries). In the meantime the situation is a completely different one. Navigation systems or services like Google Earth and Google Maps lead to broad awareness of spatial data. Using the Oracle technology as an example the session gives an overview about combining spatial with business data (converting postal addresses into coordinates, spatial queries, visualization and more) and how such an integration could leverage existing or new business applications.
Case Report: Hemosiderotic Fibrohistiocytic Lipomatous Lesion: A Clinicopathologic Characterization

Background A hemosiderotic fibrohistiocytic lipomatous lesion, also called hemosiderotic fibrolipomatous tumor, is a rare and recently described fibrolipomatous entity. Initially considered the result of a reactive inflammatory process from trauma or vascular disease, newer evidence suggests it may be neoplastic in origin.