cssi/SciSciGPT-SciSciNet huggingface dataset:
Reactive Epoxy Nanofiltration Membranes with Disulfide Bonds for the Separation of Multicomponent Chemical Mixtures

This article reports the fabrication of organic solvent nanofiltration membranes containing a labile disulfide bond, which is broken by reaction with a chemical stimulus. These membranes are a new generation of smart membranes that have tailored selectivities and flux that can be altered by reacting with a chemical stimulus. The selectivity and flux of chemicals through the membranes was controlled by varying the concentration of disulfide bonds in the membrane. When the disulfide bonds were cleaved, the pores in the membrane became larger and yielded different separation properties. The membrane selectivity was changed by up to 70% and flux was increased up to 5×. The rapid change in selectivity of the membrane allowed for the separation of three-component mixtures. A three-component mixture of 33.3% m-dinitrobenzene, 33.3% triphenylmethane, and 33.3% 1,3,5-tris(diphenylamino)benzene (TDAB) was separated into three different fractions that were significantly enriched in one of the three molecules. The first fraction contained m-dinitrobenzene at 82% purity and 84% yield, the second fraction contained triphenylmethane at 67% purity and 49% yield, and the third fraction contained TDAB at 71% purity and 88% yield.
System advisor model (SAM) simulation modelling of a concentrating solar thermal power plant with comparison to actual performance data

This paper is focused on the modelling and simulation of a 50 kW concentrated solar power (CSP) plant located in Crowley, Louisiana. The model was developed using system advisor model (SAM). The ob...
Using CGI scripts to develop a generalized on-line timed examination and grading system

The revolutionary growth and rapid success of the Internet has provided enormous opportunities to people in all fields. One such opportunity for the faculty members is to administer examinations on-line. Not all faculty members are technically inclined. This may prohibit them from using the Internet to its potential. This paper is an improved version of the paper in [3]. This paper discusses a system, which helps faculty members to create and administer on-line multiple-choice examinations, which includes a time limit. To use the system, the faculty member need not be technically proficient but should know how to use a browser. Students take examinations on-line and the system grades them immediately, announces the grade to the student and creates a log file for the instructor. The examination is timed. Students are expected to complete the exam within the time specified by the instructor. The advantage of such a timed exam is that, even when the exam is open book or "take home", the instructor can place limitation. Out system uses several Common Gateway Interface, CGI scripts.
Recurrent glioblastoma: Does the timing of bevacizumab treatment impact survival?

2039 Background: Bevacizumab (Bev) is FDA approved for use in recurrent glioblastoma (rGBM). There is limited literature on outcomes in rGBM depending on the time of initiation of Bev therapy. We e...
An EXCMG accelerated multiscale multigrid computation for 3D Poisson equation

Abstract Multiscale multigrid (MSMG) method is an effective computational framework for efficiently computing high accuracy solutions for elliptic partial differential equations. In the current MSMG method, compared to the CPU cost on computing sixth-order solutions by applying extrapolation and other techniques on two fourth-order solutions from different scales grids, much more CPU time is spent on computing fourth-order solutions themselves on coarse and fine grids, particularly for high-dimensional problems. Here we propose to embed extrapolation cascadic multigrid (EXCMG) method into the MSMG framework to accelerate the whole process. Numerical results on 3D Poisson equations show that the new EXCMG–MSMG method is more efficient than the existing MSMG method and the EXCMG method for sixth-order solution computation.
Elucidating Branching Topology and Branch Lengths in Star-Branched Polymers by Tandem Mass Spectrometry

Tandem mass spectrometry (MS2) has been employed to elucidate the topology and branching architecture of star-branched polyethers. The polymers were ionized by matrix-assisted laser desorption/ionization (MALDI) to positive ions and dissociated after leaving the ion source via laser-induced fragmentation. The bond scissions caused under MALDI-MS2 conditions occur preferentially near the core-branch joining points due to energetically favorable homolytic and heterolytic bond cleavages near the core and release of steric strain and/or reduction of crowding. This unique fragmentation mode detaches complete arms from the core generating fragment ion series at the expected molecular weight of each branch. The number of fragment ion distributions observed combined with their mass-to-charge ratios permit conclusive determination of the degree of branching and the corresponding branch lengths, as demonstrated for differently branched homo- and mikto-arm polyether stars synthesized via azide-alkyne click chemistry. The results of this study underscore the utility of MS2 for the characterization of branching architecture and branch lengths of (co) polymers with two or more linear chains attached to a functionalized central core.
Efficacy data of halogenated phenazine and quinoline agents and an NH125 analogue to veterinary mycoplasmas

Mycoplasmas primarily cause respiratory or urogenital tract infections impacting avian, bovine, canine, caprine, murine, and reptilian hosts. In animal husbandry, mycoplasmas cause reduced feed-conversion, decreased egg production, arthritis, hypogalactia or agalactia, increased condemnations, culling, and mortality in some cases. Antibiotics reduce transmission and mitigate clinical signs; however, concerning levels of antibiotic resistance in Mycoplasma gallisepticum and M. capricolum isolates exist. To address these issues, we evaluated the minimum inhibitory concentrations (MICs) of halogenated phenazine and quinoline compounds, an N-arylated NH125 analogue, and triclosan against six representative veterinary mycoplasmas via microbroth or agar dilution methods. Thereafter, we evaluated the minimum bactericidal concentration (MBC) of efficacious drugs. We identified several compounds with MICs ≤25 μM against M. pulmonis (n = 5), M. capricolum (n = 4), M. gallisepticum (n = 3), M. alligatoris (n = 3), M. agassizii (n = 2), and M. canis (n = 1). An N-arylated NH125 analogue, compound 21, served as the most efficacious, having a MIC ≤25 μM against all mycoplasmas tested, followed by two quinolines, nitroxoline (compound 12) and compound 20, which were effective against four and three mycoplasma type strains, respectively. Nitroxoline exhibited bactericidal activity among all susceptible mycoplasmas, and compound 21 exhibited bactericidal activity when the MBC was able to be determined. These findings highlight a number of promising agents from novel drug classes with potential applications to treat veterinary mycoplasma infections and present the opportunity to evaluate preliminary pharmacokinetic indices using M. pulmonis in rodents as an animal model of human infection.
Myosin-driven actin-microtubule networks exhibit self-organized contractile dynamics

The cytoskeleton is a dynamic network of proteins, including actin, microtubules, and myosin, that enables essential cellular processes such as motility, division, mechanosensing, and growth. While actomyosin networks are extensively studied, how interactions between actin and microtubules, ubiquitous in the cytoskeleton, influence actomyosin activity remains an open question. Here, we create a network of co-entangled actin and microtubules driven by myosin II. We combine dynamic differential microscopy, particle image velocimetry and particle tracking to show that both actin and microtubules in the network undergo ballistic contraction with surprisingly indistinguishable characteristics. This controlled contractility is distinct from the faster turbulent motion and rupturing that active actin networks exhibit. Our results suggest that microtubules can enable self-organized myosin-driven contraction by providing flexural rigidity and enhanced connectivity to actin networks. These results provide important new insight into the diverse interactions cells can use to tune activity, and offer a powerful platform for designing multifunctional materials with well-regulated activity.
Theoretical Foundations of Hyperdimensional Computing.

Hyperdimensional (HD) computing is a set of neurally inspired methods for obtaining high-dimensional, low-precision, distributed representations of data. These representations can be combined with simple, neurally plausible algorithms to effect a variety of information processing tasks. HD computing has recently garnered significant interest from the computer hardware community as an energy-efficient, low-latency, and noise-robust tool for solving learning problems. In this review, we present a unified treatment of the theoretical foundations of HD computing with a focus on the suitability of representations for learning.
Disease Emergence in Multi-Patch Stochastic Epidemic Models with Demographic and Seasonal Variability

Factors such as seasonality and spatial connectivity affect the spread of an infectious disease. Accounting for these factors in infectious disease models provides useful information on the times and locations of greatest risk for disease outbreaks. In this investigation, stochastic multi-patch epidemic models are formulated with seasonal and demographic variability. The stochastic models are used to investigate the probability of a disease outbreak when infected individuals are introduced into one or more of the patches. Seasonal variation is included through periodic transmission and dispersal rates. Multi-type branching process approximation and application of the backward Kolmogorov differential equation lead to an estimate for the probability of a disease outbreak. This estimate is also periodic and depends on the time, the location, and the number of initial infected individuals introduced into the patch system as well as the magnitude of the transmission and dispersal rates and the connectivity between patches. Examples are given for seasonal transmission and dispersal in two and three patches.
Rural electrification, migration and structural transformation: Evidence from Ethiopia

Abstract To what extent does rural electrification induce structural change and alter migration patterns? This paper addresses this question using a simple multi-sector spatial model and evidence from a panel of rural Ethiopian villages during its recent expansion of electricity supply. We find that electrification raised irrigation rates, agricultural yields and non-agricultural business activity. Furthermore, electrified villages experienced higher rates of in-migration and lower rates of out-migration. Each of these predictions is qualitatively consistent with the predictions of our model. Our results suggest that rural electrification helped facilitate structural transformation of villages economies in Ethiopia and slowed out-migration from rural areas.
Transitions in "Privatized" Prison Health Systems: Emergency Department Visits and Hospitalizations Among Incarcerated People in Florida, 2011-2018.

Objectives. To examine rates of emergency department (ED) visits and hospitalizations among incarcerated people in Florida during a period when health care management in the state’s prisons underwe...
Cigarette Relighting: A Series of Pilot Studies Investigating a Common Yet Understudied Smoking Behavior.

Background: The act of extinguishing, saving, and later relighting unfinished cigarettes is a common yet understudied behavior that may have implications for tobacco treatment and health. Methods: This paper presents four pilot studies investigating various aspects of this topic: (1) the prevalence of relighting among NJ and NY Quitline callers (n = 20,984); (2) the prevalence and correlates of relighting in two national surveys (n = 1008, n = 1018); (3) a within-subject (n = 16) laboratory experiment comparing cigarettes smoked per day and exhaled carbon monoxide when relighting and not relighting cigarettes; and (4) a national survey of tobacco treatment providers’ (n = 150) perceptions of relighting. Results: Relighting was found to be common (approximately 45% of smokers), and associated with lower socioeconomic status, heavier smoking and nicotine dependence, greater smoking-related concerns, as well as high levels of exhaled carbon monoxide. Providers noted the potential importance of relighting but reported that they do not regularly incorporate it into their assessment or tobacco treatment planning. Conclusions: These findings address a major research gap in the emerging research on this common behavior. Future research is needed to better understand the potential implications of relighting for policies and clinical practices related to tobacco cessation and health.
The Significance of Utilizing A Corticotomy on Periodontal and Orthodontic Outcomes: A Systematic Review and Meta-Analysis.

Purpose: This systematic review compares the clinical and radiographic outcomes for patients who received only a corticotomy or periodontal accelerated osteogenic orthodontics (PAOO) with those who received a conventional orthodontic treatment. Methods: An electronic search of four databases and a hand search of peer-reviewed journals for relevant articles published in English between January 1980 and June 2021 were performed. Human clinical trials of ≥10 patients treated with a corticotomy or PAOO with radiographic and/or clinical outcomes were included. Meta-analyses were performed to analyze the weighted mean difference (WMD) and confidence interval (CI) for the recorded variables. Results: Twelve articles were included in the quantitative analysis. The meta-analysis revealed a localized corticotomy distal to the canine can significantly increase canine distalization (WMD = 1.15 mm, 95% CI = 0.18–2.12 mm, p = 0.02) compared to a conventional orthodontic treatment. In addition, PAOO also showed a significant gain of buccal bone thickness (WMD = 0.43 mm, 95% CI = 0.09–0.78 mm, p = 0.01) and an improvement of bone density (WMD = 32.86, 95% CI = 11.83–53.89, p = 0.002) compared to the corticotomy group. Conclusion: Based on the findings of the meta-analyses, the localized use of a corticotomy can significantly increase the amount of canine distalization during orthodontic treatment. Additionally, the use of a corticotomy as a part of a PAOO procedure significantly increases the rate of orthodontic tooth movement and it is accompanied by an increased buccal bone thickness and bone density compared to patients undergoing a conventional orthodontic treatment.
Increased expression and activity of Akt in primary ductal breast cancers and activation of the ErbB2/Akt/ER- α pathway

3575 Introduction: We have previously demonstrated that Akt1 is activated not only by epidermal growth factor (EGF), insulin-like growth factor I (IGF-I), and heregulin-β1 (HRG-β1), but also by estradiol. This cross-talk between growth factors and estrogen receptor-α (ER-α) signaling converges in the EGF receptor family member, ErbB2 / phosphatidylinositol 3-kinase PI 3-K/serine/threonine protein kinase Akt pathway in hormone-dependent MCF-7 breast cancer cells in vitro and xenografts grown in vivo. The aim of the present study was to investigate whether the current model of this tumorigenic pathway is active in clinical breast cancer. Methods: We analyzed the expression levels of Akt1 and phosphorylated Akt (pAkt) by immunohistochemistry and western blot analysis in pairs of frozen tumor samples and their corresponding matched normal adjacent lobular breast tissue from 58 breast cancer patients. These patients did not have a previous history of therapeutic intervention. The tumors were mostly invasive, high grade, ductal carcinomas, with an approximately equal distribution of ER-α, ErbB2, and lymph node positivity. Spearman’s rank correlations were calculated for Akt expression and phosphorylation, measured by either immunohistochemistry or western blot, and patient and clinical-pathological tumor classification. Results: Marked staining was observed for Akt1 in 98% of the tumors and pAkt was expressed in 83%. Akt1 was localized mostly in the cytoplasm, but also in the nucleus. Normal tissues revealed much less staining for Akt1 and pAkt than tumor tissue, also with more cytoplasmic localization and less nuclear staining. Nuclear Akt1 measured by immunohistochemistry was highly correlated with Akt1 expression measured by western blot analysis (Akt-WB) (p=0.04), cytoplasmic Akt1 (cyt Akt) (p=0.006), and nuclear pAkt (p=0.003). Additionally, nuclear pAkt was highly correlated with phosphorylated cytoplasmic Akt (cyt pAkt) (p=0.001). Akt1 and pAkt expression were not significantly correlated with age, tumor type, nuclear grade, lymph node positivity, progesterone receptor (PR), or the proliferation rate, Ki67. Nuclear Akt1 and cyt pAkt were each significantly correlated with tumor size (p=0.02). Cyt pAkt was positively correlated with histological grade (p=0.02) and inversely correlated with ER-α status (p=0.04) and with ErbB2 expression (p=0.05). Nuclear pAkt was also inversely correlated with ErbB2 (p=0.04). pAkt measured by western blot (pAkt-WB) was also associated with tumor size (p=0.03). Conclusion: Similar to our in vitro model and animal data, in invasive, high grade, ductal carcinomas, Akt expression and activity is high and correlates with ErbB2 and ER-α expression, histological grade, and tumor size.
Physico-Chemical Properties of Soils: A Symposium: Ion Exchange Phenomena

The origin of the various types of electrical charges carried by soil colloids are described and the influence of different species of exchangeable cations on the forces arising from the electrical...
Fluctuation Effects in Electron Systems: Their Role in Electron-Pairing Mechanisms

Electron-electron correlation effects are considered in a system in which the electrons are divisible into two broad classes, namely, quasilocalized and itinerant. In the former they are treated in terms of fluctuating multipole interactions and the resulting collective excitations, namely, extended polarization waves are shown to lead to attractive electron-electron interactions in the itinerant class. This mechanism is particularly effective if an overall energy gap exists above the occupied states in the single-particle spectrum. If the itinerant class is quite dilute, it is suggested that by going beyond RPA the direct Coulomb repulsive term is diminished.
Virus Vectors for use in the Central Nervous System: Problems in the Use of Herpes Simplex Virus as a Vector

Publisher Summary This chapter explains the general features of the lytic and latent phases of the viral life cycle and focuses on molecular aspects as they relate to either expression or toxicity. The molecular aspects of amplicons and how they work are presented. The molecular basis of long-term expression in neuronal latency is discussed. The chapter also discusses other aspects of herpes simplex virus (HSV) vectors such as applications to neuronal disease and applications to the use of HSV and the HSV viral thymidine kinase to target cancer cells for destruction. Substantial improvement in HSV as a vector has been obtained in reduction of the toxicity of the virus, either through deletion of genes or through the help-free amplicon approach. Expression of transgenes from the virus could be further improved, particularly in the central nervous system. Exactly how helpful HSV will be will depend on the system as well as on the ability to infect as many cells as possible without doing harm.
Characterisation and Performance of Short-channel Polysilicon Thin-film Transistors

The influence of a range of device parameters on short-channel threshold shifts in n- and p-channel polysilicon TFTs is reported. Reducing the gate dielectric thickness reduces the shifts at low drain bias, but is less effective at high drain bias where channel avalanche multiplication is significant. The polysilicon island thickness has little influence, but passivation of the grain boundaries by hydrogenation does improve the short channel performance.
The Amino Acid Sequence of the Tryptic Peptides from Cytochrome b5

Abstract Apocytochrome b5 was hydrolyzed with trypsin and the resulting peptides were resolved on Dowex 1 and Dowex 50 columns. The expected 11 peptides were isolated and fragmented further with papain and pepsin. The complete amino acid sequences of these peptides were determined by carboxypeptidase A and B and Edman degradation procedures.
Factors influencing isometric exercise training-induced reductions in resting blood pressure.

Hypertension is a major health concern, and current recommendations for blood pressure management (lifestyle modifications and pharmacological intervention) have not been universally successful. For two decades, isometric exercise training (IET) has become established as effective at reducing in resting BP (RBP) in a short period (4–10 weeks). The most common IET modes have comprised isometric handgrip (IHG) or isometric bilateral leg (IBL) training and 4 × 2-min contractions at ∼20–50% maximal voluntary contraction with 1–5-min rest between. Although this type of exercise training could have important implications, for hypertensive patients and in preventing hypertension development, little is known about the mechanisms responsible for IET-induced RBP reductions. This uncertainty derives from a lack of understanding concerning the most effective IET programs for specific populations. Possible influential factors and mechanisms include age, sex, pre-existing disease and medication, and IET-induced adaptations in the exercising muscle and nervous system, which are discussed in this review. Designing effective IET programs may involve manipulation of exercise intensity, frequency, duration and mode, as well as consideration of yet discovered mechanisms for RBP reductions. We call for additional research designed to understand more about the mechanisms involved in IET-induced RBP reductions for maximum effectiveness.
Treatment of the medial collateral ligament injury. II: Structure and function of canine knees in response to differing treatment regimens.

In order to assess the healing of the medial collateral ligament (MCL) and to detect the various effects of treatment regimens, in vivo animal experiments using a canine model were performed. Thirty-five canine MCLs were surgically transected and treated using three clinically popular regimens, e.g., no repair with cage and farm activities (Group 1), repair with 3 weeks immobilization (Group 2), and repair with 6 weeks im mobilization (Group 3). The varus-valgus laxity of the knee joint, structural properties of the femur-MCL-tibia (FMT) complex and the mechanical properties of the MCL substance (healing site) were quantitatively meas ured at 6, 12, and 48 weeks postoperatively. It was found that Group 1 animals had the best results. The varus-valgus laxity of the knee joint and the structural properties of the FMT complex returned to values comparable with the contralateral control by 12 weeks. The recovery of the mechanical properties of the MCL substance was slower and not complete, even at 48 weeks. I...
Impact wear testing machine

Abstract An impact testing machine has been built to aid in the study of wear occurring on surfaces of repetitively loaded solid bodies. In this testing machine, bullet-shaped projectiles are bounced against a metal surface which is either stationary or rotating about an axis parallel to the approach of the projectiles. Wear can occur on both the projectile and on the surface it strikes, and both may be measured; however, unless impacts are synchronized, observation of progressive wear must be restricted to the projectile surface. These measurements made on the bullet surfaces yield information on “one-body wear”. The rotation of the impacted medium is expected to facilitate a study of the relative importance of sliding when the relative approach of the two bodies has a tangential as well as a normal component. In this paper the testing machine is described, and some typical photographs of impacted specimens are shown at various stages of wear.
Electron-ion collisions by the R-matrix method with multichannel quantum-defect theory.

Collisions are treated by a method that has been very successful in calculating atomic spectra. Results of electron collisions with Be{sup +}, Mg{sup +}, and Ca{sup +} are presented, showing extensive series of double excitation resonances of the collision complex. Convergence of the results to the limit of peripheral collisions, where the Born approximation holds, is displayed. Cross sections of optically allowed and forbidden excitations are evaluated, including cascade effects and distributions in the scattering angle. The polarization of emissions from the excited target is calculated successfully.
Wikis to support the “collaborative” part of collaborative learning

Prior research has highlighted the value of using wikis to support learning. This paper makes the case that the wiki has several properties that are particularly amenable for constructing applications that support the “collaborative” part of a variety and range of different time/different place student collaborations. In support of the argument, the paper presents the WikiDesignPlatform (WDP). The WDP supplies a suite of awareness, navigation, communication, transcription, and analysis components that provide additional functionality beyond the standard wiki feature set. Two case studies are presented, which have different coordination, communication, and awareness requirements for the “collaborative” part of the students’ collaborative learning activities. The evidence shows that under both conditions, a prefabricated wiki provides a sufficiently rich intersubjective space that adequately supports the students’ collaborative work.
EFFECT OF HYPOPHYSECTOMY AT THE BEGINNING OF PROESTRUS ON MATURING FOLLICLES IN THE OVARY OF THE RAT1

DURING the past twenty years a large amount of information has accumulated concerning the relationship between the gonadotrophic hormones and various aspects of ovarian development and function, but there are still many questions which have not been fully answered. The increasing use of gonadotrophic hormone preparations to induce follicular maturation and ovulation in the human being and in domestic animals has reemphasized the need for more precise qualitiative and quantitative data concerning the hormonal factors necessary for the maintenance and development of maturing follicles just prior to ovulation. Hertz and Meyer (1946) have shown that removal of the pituitary gland in the rat at the beginning of proestrus will prevent ovulation from taking place during the subsequent 46 hour period. From this work it was concluded that a hypophyseal hormone (LH) is required for ovulation in the rat and the necessary quantity is secreted subsequent to early proestrus.
The Profits and the Perils of Partnership in the “Thrilling” Saga of William and Ellen Craft

In October 1937, the historian Carter Godwin Woodson (1875–1950) launched the inaugural issue of the Negro History Bulletin. A teacher of social science and language in the secondary schools of the District of Columbia, Woodson dedicated his career to disseminating knowledge, correcting myths, and presenting accurate analyses of the roles of African Americans in US history. In 1915, he founded the progenitor of today’s Association for the Study of Negro Life and History (ASALH), and in February 1926, he initiated Negro History Week, now a month-long celebration (Hine 405-8). His Negro History Bulletin, a monthly publication for students and educators, inserted the voices of black scholars and critics into Jim Crow America’s segregated African American classrooms (Goggin 1-65). The Bulletin debuted with a front page featuring “The Thrilling Escape of William and Ellen Craft,” about the couple’s journey from slavery in Georgia to freedom in New England, which is framed by a triptych of woodcuts by the African American artist Lois Mailou Jones (1905–1998) (“Thrilling” 1, 5). Almost ninety years had passed since the couple’s feisty 1848 flight from Macon, Georgia, when the light-skinned Ellen Craft (1826–1891) had attired herself as a white, Southern, slaveholding gentleman. She and her dark-skinned husband William (1824–1900), pretending to be her slave, had slipped out from under what they called captivity’s “iron heel of despotism” (Craft and Craft 10), hiding in plain sight among white, Southern, slaveholding travelers on trains, carriages, and steamers conveying them North. “Persons still living,” wrote this issue of the Bulletin, “speak of the benefits they received from coming under the influence of William and Ellen Craft” (“Thrilling” 5). Uncertain whether they would ever return to America, the Crafts spent almost twenty years in transatlantic exile—obtaining an education, making a living, nurturing five children, frantically fund-raising to purchase the freedom of still-enslaved family members—based mostly in their home and sometime boardinghouse at 12 Cambridge Court in Hammersmith, a suburb of London. Only a few months into their English asylum in 1851, William Craft admitted “he had himself a father, and a brother and sisters, and his wife had a mother and a grandmother, who were dragging out life in bondage” (American 17). Six years later, The Newcastle Courant reported that William had “by his ability” tracked down his mother and liberated her from slavery and was working on purchasing his sister’s freedom from her New Orleans owner
Strategies for Preventing Behavioral Incidents in the Nation's Secondary Schools

(1985). Strategies for Preventing Behavioral Incidents in the Nation's Secondary Schools. The Clearing House: A Journal of Educational Strategies, Issues and Ideas: Vol. 58, No. 8, pp. 349-353.
Driving dendrimers with light: Dendrimers with azobenzene central linkers

Several new classes of azobenzene-containing dendrimers have been prepared and characterized. Three central linker azobenzenes, p-(p-hydroxyphenylazo)phenol (A), aniline p-(p '-chlorocarbonylphenylazo)benzoy chloride (B), and p-(p'-aminophenylazo) (C) were reacted with the appropriate dendritic fragment ([Gn]Br for A and C; [Gn]OH for B) to yield dendrimers 1-3 of varying generational size. The photoresponsive characterization of these dendrimers illustrates the insensitivity of the photoresponsive behavior of the azobenzene with respect to the nature of the attached dendritic fragment.
Application of Latent Class Growth Model to Longitudinal Analysis of Traffic Crashes

One of the most important and meaningful tasks in traffic safety is to describe how traffic crash risk changes over time. Over the past 20 years, much work has been done about this task. The recent introduction of latent class models to analyze crash data has created a need to examine how these models could be used for longitudinal data analysis. Latent class models dictate that part of the heterogeneity be attributed by grouping distinct subpopulations into a common data set. Investigation of the commonalities of the subgroups can be useful for targeting specific safety interventions. This paper describes the application of the latent class growth model (LCGM), which is tailored to longitudinal data. Analysis was accomplished with the use of data collected between 1997 and 2007 on rural, two-lane highways in Texas. Trends for all crash severities and injury crashes were examined. It was determined that the crash data could be drawn from three population subgroups for which crash risks were low, medium, and high. The results of this study showed that average shoulder width and speed limit had stronger effects at sites classified as high crash risks, whereas traffic flow had a stronger influence at sites classified as low risks. As expected, higher speed limits increased crash risk, whereas a wider shoulder width reduced risk. In conclusion, the LCGM showed good potential for use in the analysis of longitudinal data, but further research is needed.
Use of data in a radiology information system for labeling computed radiographs: an interface to connect the two systems.

Computers have greatly facilitated the processing and storage of radiologic information. Manufacturers of radiology information systems (RISs) are gradually incorporating options for interfacing their products with other computers (e.g., hospital information systems). However, a growing need exists to also interface RISs with digital radiologic equipment so that images (e.g., computed radiographs of the chest and skeleton) are automatically labeled with identification data. Such connectivity would eliminate redundant work by technologists, decrease errors in the labeling of images, and increase the consistency of patients' data within a radiology department. Unfortunately, the rapid advances in digital technology, combined with the lack of a well-defined standard for the transfer of demographic information between dissimilar systems, have delayed development of these interfaces. We have developed a widely applicable method to automatically transfer patients' demographic data from an RIS to a commercially ...
Room temperature photopumped ZnSe lasers

Room-temperature laser oscillation at 469 nm observed in photopumped bulk ZnSe is discussed. The result was obtained by using a pump photon energy very close to the bandgap energy and by enhancing the resonator Q with high-reflectivity coatings. Threshold pump power densities as low as 370 kW/cm/sup 2/ were measured. >
Stress-induced hydrogen reorientation in a bcc Nb-50-at. %-V alloy.

A stress-induced reorientation relaxation due to interstitial hydrogen in a Nb--50-at. %-V alloy has been investigated by internal friction for H concentrations between 2.5 and 28 at. %. The peak is interpreted as a Snoek-type relaxation with a distribution of activation energies across the peak from 0.05 to 0.25 eV. This energy spectrum is due to differing environments of the interstitial hydrogen owing to a variation of the chemical short-range order in the alloy. The internal-friction maximum and the values for the modulus defect are roughly linear in concentration, indicating that H clustering is not involved. The reduction of the modulus with decreasing temperature at temperatures above the peak, but not below, is associated with the reorientation phenomenon. There is no evidence for hydride formation in this alloy for hydrogen concentrations to C/sub H/ = 0.28, down to temperatures of approx.6 K.
Drug-abuse prevention education: Scope, problems, and prospective

Abstract The initial practical decision that has to be made in developing a drug prevention program has to do with the type of drug abuse we are most concerned about, and the type and quality of individual and community functioning we wish to reinforce or inhibit. We must acknowledge that, to date, prevention of drug abuse through education has not been successful. But prevention, based on offering meaningful alternatives to the nonmedical use of drugs and effective education is still our best hope. Instead of reacting to our present inadequacies with despair, we must increase our efforts with carefully planned programs accompanied by long-term, impartial evaluation. If we are willing to adopt this approach, surely we can develop preventive educational programs that will be effective.
Association of the dispersion in red blood cell volume with mortality.

Background The red cell distribution width (RDW) predicts mortality among many populations. RDW is calculated as the standard deviation (SD) of the red blood cell (RBC) volume divided by mean corpuscular volume (MCV). Because higher MCV also predicts mortality, we hypothesized that the RDW numerator (one SD of RBC volume or 1SD-RDW) predicts mortality more strongly than the RDW. Material and methods Adult subjects hospitalized during a contemporary clinical era (10/2005-1/2014, N = 135 963) and a historical era (1/1999-9/2005, N = 119 530) were studied. The RDW was obtained from the complete blood count (CBC), while 1SD-RDW was calculated (RDW multiplied by MCV and divided by 100). Results In univariable Cox regression (2005–2014 cohort), 1SD-RDW (quintile 5 vs. 1: hazard ratio [HR] = 8·38, 95% confidence interval [CI] = 7·94, 8·85; P < 0·001) was a superior predictor of mortality compared to RDW (quintile 5 vs. 1: HR = 4·78, CI = 4·57, 5·00; P < 0·001). This superiority remained after adjustment for age, sex, basic metabolic profile components and other CBC factors excluding MCV (1SD-RDW: HR = 2·41, CI = 2·28, 2·55; RDW: HR = 2·01, CI = 1·92, 2·11). Further adjustment for MCV strengthened the RDW association (HR = 2·14, CI = 2·04, 2·24; P < 0·001), becoming indistinct from 1SD-RDW (HR = 2·20, CI = 2·08, 2·33; P < 0·001). Findings were similar for the 1999–2005 cohort. Conclusions The 1SD-RDW predicted mortality more strongly than RDW, suggesting that 1SD-RDW is superior to RDW as an individual risk predictor. Further, these results indicate that the dispersion of RBC volume and its mean are independent risk markers. Further research is required to understand the clinical value and mechanistic basis of these associations.
Adaptive timing, attention, and movement control

Examples of how LTP and LTD can control adaptively-timed learning that modulates attention and motor control are given. It is also suggested that LTP/LTD can play a role in storing memories. The distinction between match-based and mismatch-based learning may help to clarify the difference.
New breathing functions for the transverse breathing crack of the cracked rotor system: Approach for critical and subcritical harmonic analysis

The actual breathing mechanism of the transverse breathing crack in the cracked rotor system that appears due to the shaft weight is addressed here. As a result, the correct time-varying area moments of inertia for the cracked element cross-section during shaft rotation are also determined. Hence, two new breathing functions are identified to represent the actual breathing effect on the cracked element stiffness matrix. The new breathing functions are used in formulating the time-varying finite element stiffness matrix of the cracked element. The finite element equations of motion are then formulated for the cracked rotor system and solved via harmonic balance method for response, whirl orbits and the shift in the critical and subcritical speeds. The analytical results of this approach are compared with some previously published results obtained using approximate formulas for the breathing mechanism. The comparison shows that the previously used breathing function is a weak model for the breathing mechanism in the cracked rotor even for small crack depths. The new breathing functions give more accurate results for the dynamic behavior of the cracked rotor system for a wide range of the crack depths. The current approach is found to be efficient for crack detection since the critical and subcritical shaft speeds, the unique vibration signature in the neighborhood of the subcritical speeds and the sensitivity to the unbalance force direction all together can be utilized to detect the breathing crack before further damage occurs.
Preliminary crystallographic analysis of GpgS, a key glucosyltransferase involved in methylglucose lipopolysaccharide biosynthesis in Mycobacterium tuberculosis

Glucosyl-3-phosphoglycerate synthase (GpgS) is a key enzyme that catalyses the first glucosylation step in methylglucose lipopolysaccharide biosynthesis in mycobacteria. These important molecules are believed to be involved in the regulation of fatty-acid and mycolic acid synthesis. The enzyme belongs to the recently defined GT81 family of retaining glycosyltransferases (CAZy, Carbohydrate-Active Enzymes Database; see http://www.cazy.org). Here, the purification, crystallization and preliminary crystallographic analysis are reported of GpgS from Mycobacterium tuberculosis and of its complex with UDP. GpgS crystals belonged to space group I4, with unit-cell parameters a = 98.85, b = 98.85, c = 127.64 A, and diffracted to 2.6 A resolution. GpgS–UDP complex crystals belonged to space group I4, with unit-cell parameters a = 98.32, b = 98.32, c = 127.96 A, and diffracted to 3.0 A resolution.
Photochemistry of polymers and copolymers of phenyl vinyl ketone and o-tolyl vinyl ketone

Energy migration plays an important role in the photochemistry of polymers containing phenyl vinyl ketone (PPVK) and o-tolyl vinyl ketone (PTVK) units. The average residence time of the triplet excitation in any given chromophore is in the neighborhood of 30 ps. Triplet lifetimes are estimated as 55 ns for PPVK and 2 ns for PTVK and are intermediate for all the copolymers. Biradical lifetimes are 65 ns for PPVK and 200 ns for PTVK, reflecting the longer lifetime of the biradicals derived from the o-methylbenzoyl group. Photoenolization of the o-tolyl vinyl ketone moieties provides an energy sink, reducing the degree of photodegradation. For example, a copolymer of phenyl vinyl ketone and o-tolyl vinyl ketone containing 3% of the latter undergoes only 54% of the degradation undergone by PPVK.
Sonographic Diagnosis Of Posterior Interosseous Nerve Entrapment Syndrome

Posterior interosseous nerve entrapment is a potential cause of upper extremity muscle weakness and pain. The diagnosis may be difficult to make clinically, and electrodiagnostic tests may not identify the exact site of nerve compression. We report a case of posterior interosseous nerve entrapment in which electrodiagnostic studies suggested radial neuropathy at the level of the spiral groove, but the sonographic evaluation pinpointed the arcade of Frohse as the level of compression. The patient’s symptoms improved dramatically following surgical release of the nerve. Sonography may be a valuable, non-invasive diagnostic tool in evaluating patients with posterior interosseous nerve entrapment.
A case for space: physical and virtual location requirements in the CouchSurfing social network

This paper describes a Location Based Social Network (LBSN) built upon activities that combine virtual and physical location. While many modern social networks are based in the virtual world and strengthen pre-existing connections, the CouchSurfing social network is built upon creating new face-to-face connections between members across the world. The network has connected travelers to cost-free lodging for over 5 years with over 1 million current members. Now it provides a large user database where each user is tagged with a location. This is useful for spatial data mining and knowledge discovery as recommendations about locations are left in user reviews of one another. These are drawn upon to find interesting locations and discover new places, people and activities. Techniques from the field of time geography are used with LBSN information about individual member location to show how spatiotemporal constraints combine the virtual and physical worlds. Additionally, mobile devices afford flexible utility for the LBSN and applications are presented that take advantage of this.
Time-dependent interfacial failure in metallic alloys

Time-dependent intergranular brittle fracture has now been studied experimentally in a number of alloy systems, and the generic features are becoming clear. Mobile surface-adsorbed elements are caused to diffuse inward along grain boundaries under the influence of a tensile stress, and this can lead to sub-critical crack growth by decohesion. Oxygen is found to play this role in nickel-base superalloys and intermetallics, as well as in a precipitation-strengthened Cu–Be alloy. Crack-growth rates lie in the range 10−7–10−4 m sec−1. The same kind of cracking is found in steels treated so that free sulfur is able to segregate to the surface, as well as in Cu-Sn alloys, in which the embrittling element is surface-segregated Sn. The latter has been studied in bicrystals, and the importance of the variation in diffusivity with grain boundary structure has been documented. Hydrogen-induced cracking is a special case of an extremely mobile embrittling element and is responsible for much of the brittleness found in intermetallics. The effect of boron in retarding brittle behavior in Ni3Al has been shown to result partly from its interaction with hydrogen. This is a prime example of how segregated solutes can be used to ameliorate the tendency for diffusion-controlled brittle fracture.
Characterizing dataset dependence for sparse matrix-vector multiplication on GPUs

Sparse matrix-vector multiplication (SpMV) is a widely used kernel in scientific applications as well as data analytics. Many GPU implementations of SpMV have been proposed, proposing different sparse matrix representations. However, no sparse matrix representation is consistently superior, and the best representation varies for sparse matrices with different sparsity patterns. In this paper we study four popular sparse representations implemented in the NVIDIA cuSPARSE library: CSR, ELL, COO and a hybrid ELL-COO scheme. We analyze statistical features of a dataset of 27 matrices, covering a wide spectrum of sparsity features, and attempt to correlate SpMV performance with each representation with simple aggregate metrics of the matrices. We present some insights on the correlation between matrix features and the best choice for sparse matrix representation.
Learning to plan in continuous domains

Abstract In this paper, we propose an approach to planning in domains with continuous world features. We argue that current models of world change (including traditional planners, reactive systems, and many connectionist systems) implicitly adopt a discrete action assumption which precludes efficient reasoning about continuous world change. A formalism for continuous world change is outlined, and an ideal continuous domain planner is defined. An implemented computationally tractable approximation to the ideal planner is discussed and its behavior is described. Empirically, the implementation is shown to exhibit some of the important design features of the new planning approach. Learning plays a central role in this approach. With experience, accuracy is increased and planning time is reduced even though the system's background knowledge of the world is only approximate or “plausible”. The acquired planning concepts are most accurate in situations similar to the ones in which they are most exercised. Thus, the approach possesses a natural adaptation to systematic properties implicit in the observed distribution of problems.
THE IMPORTANCE OF SCALE IN MEASURING THE SECONDARY EFFECTS IN REGRESSION ANALYSIS

This study proposes a method of using ecological1 variables in regression analysis to identify the weak or secondary effects of independent variables without introducing spurious correlation due to aggregation.
Knowledge-based segmentation of pediatric kidneys in CT for measuring parenchymal volume

The purpose of this work was to develop an automated method for segmenting pediatric kidneys in contrast-enhanced helical CT images and measuring the volume of the renal parenchyma. An automated system was developed to segment the abdomen, spine, aorta and kidneys. The expected size, shape, topology an X-ray attenuation of anatomical structures are stored as features in an anatomical model. These features guide 3-D threshold-based segmentation and then matching of extracted image regions to anatomical structures in the model. Following segmentation, the kidney volumes are calculated by summing included voxels. To validate the system, the kidney volumes of 4 swine were calculated using our approach and compared to the 'true' volumes measured after harvesting the kidneys. Automated volume calculations were also performed retrospectively in a cohort of 10 children. The mean difference between the calculated and measured values in the swine kidneys was 1.38 (S.D. plus or minus 0.44) cc. For the pediatric cases, calculated volumes ranged from 41.7 - 252.1 cc/kidney, and the mean ratio of right to left kidney volume was 0.96 (S.D. plus or minus 0.07). These results demonstrate the accuracy of the volumetric technique that may in the future provide an objective assessment of renal damage.