cssi/SciSciGPT-SciSciNet huggingface dataset:
Crystallization and molecular-replacement studies of a recombinant antigen-binding fragment complexed with single-stranded DNA.

Anti-DNA antibodies have been implicated in autoimmune diseases and also serve as models for understanding protein–DNA recognition. Crystals of a recombinant antigen-binding fragment (Fab) complexed with dT5 have been obtained and initial phases have been determined using molecular replacement. The crystals diffract to 2.1 A resolution and occupy space group P6522, with unit-cell parameters a = 171.8, c = 144.6 A; there are two Fabs per asymmetric unit. X-PLORdirect rotation-function calculations followed by Patterson correlation filtering were successful when using a Fab search model; however, they failed when using the individual variable and conserved domains of the Fab as search models. AMoRe successfully identified the correct solution in cases where X-­PLOR failed.
Differential expression of vascular endothelial growth factor–A isoforms at different stages of melanoma progression

Abstract Background Vascular endothelial growth factor-A (VEGF-A) is an important mediator of angiogenesis in normal and neoplastic tissues. Total VEGF-A levels have been associated with melanoma progression, but the relative contributions of each isoform is unknown. To determine whether differences in the production of any or all of the major VEGF-A isoforms are related to stage of progression, we compared message levels for the three major isoforms of VEGF in melanoma specimens from different stages of progression. Study design Primary melanomas (N = 18), primary recurrences (N = 5), regional dermal metastases (N = 11), nodal metastases (N = 12), normal lymph nodes (N = 18), and distant metastases (N = 9) were prospectively collected. Samples from the horizontal and vertical growth phases of primary tumors were also collected from five additional patients. Message levels for the three major VEGF-A isoforms were measured using real-time quantitative reverse–transcriptase polymerase chain reaction and normalized to β-actin mRNA levels. Results There was a marked increase in the expression of all three VEGF-A isoforms from the vertical growth phase tissue as compared with the horizontal growth phase tissue. Primary tumors, local recurrences, regional dermal metastases, nodal metastases, and distant metastases all produced more VEGF 121 and VEGF 165 than negative nodes. Nodal metastases produced the highest level of these two isoforms, higher even than distant metastases. There was no significant difference in VEGF 189 message among the groups. Conclusions Melanomas in the vertical growth phase produce more VEGF-A (all isoforms) than in the horizontal growth phase. Nodal metastases produce the highest levels of VEGF 121 and VEGF 165 , but not VEGF 189 as compared with other stages of progression. These data suggest that the soluble forms of VEGF-A might be an important factor in melanoma metastasis to regional lymph nodes.
Effects of xenon and krypton on regional cerebral blood flow in the rat.

The effects of high inspired concentrations of xenon and krypton on regional CBF (rCBF) were assessed in the rat using [14C]iodoantipyrine and quantitative autoradiography. Inhalation of 80% xenon ...
Performance And Modeling Of The Gsfc Pointing Acquisition And Tracking System For Laser Communications

In this paper the NASA Goddard Space Flight Center (GSFC) laser communication pointing, acquisition, and tracking laboratory demonstration program is discussed. This program entails the construction of a flexible brass-board simulation tool, and a supporting computer simulation effort. The result of this program will be a viable test bed to support the design and specification of space-based laser communication terminals and, additionally, to address critical performance issues such as tracking robustness in the presence of background (e.g., stellar or earth) noise and/or internally generated thermal noise.
Gauged Kac-Moody algebras

We construct a non-Abelian field theory by gauging a Kac-Moody algebra. One obtains an infinite tower of interacting vector fields and associated ghosts obeying slightly modified Feynman rules.
7.6.1 Applying the Object Oriented Systems Engineering Method to A Simple Hardware System

The application of Object-Oriented Systems Engineering Method (OOSEM) to hardware systems has been controversial since it was initiated. This paper will explore its applicability and its effectiveness relative to traditional systems engineering approach. A simple Mouse Trap hardware system was used for the case study. The System Requirements can be derived from the System Diagram. The Activity Diagram can be used to visualize the workflow scenario. The Sequence Diagram can provide earlier interface identification between subsystems. The Collaboration Diagram shows the functional and physical data between subsystems. The Logical Architecture and allocation can generate logical components and develop the Class Diagram for subsystems. The design of this simple hardware system can be accomplished using the OOSEM. A definitive conclusion cannot be made as to which approach, between the traditional systems engineering and OOSEM, is better in assisting a simple hardware system design.
Preschoolers' contribution to their diagnosis of depression and anxiety: uses and limitations of young child self-report of symptoms.

The assessment of psychopathology in preschool aged children has traditionally relied exclusively on adult informants as children under 6 years-of-age have been widely regarded as developmentally unable to serve as valid reporters of their own mental state. Based on the finding of a valid preschool depressive syndrome, methods to obtain self-report of symptoms of depression and related anxiety directly from the child are now needed. The Berkeley Puppet Interview (BPI), a novel measure of psychopathology designed for the young child informant, was administered to N = 110 preschool study subjects aged 4.0–5.6 who participated in a comprehensive assessment of preschool depression. Parents filled out the Child Behavioral Checklists (CBCL) and the diagnosis was derived using parent report on the Diagnostic Interview Schedule for children, version IV (DISC-IV-YC) at baseline and 6 months later. Findings suggest that young children may serve as useful reporters of several core and basic symptoms of depression and anxiety based on significant correlations with a variety of parent report measures administered concurrently and 6 months later. However, no significant correlations were found between preschool reports of more complex or abstract symptoms. These findings taken together suggest that the young child can validly self-report on some key aspects of depression and anxiety and that self-report of young children should be sought in these domains. Findings also suggested that these self-reports are limited to the core and basic symptoms of these disorders and that direct age appropriate approaches may not be useful beyond that domain.
Mobile Capacitor Units for Emergency Loading of Transformers in Open Delta

Loading of closed delta banks of substation transformers to a point approaching safe thermal limit results in severe overloading of two transformers as well as decided unbalance in voltage and current when operated in open delta as a result of the failure of one transformer. By the use of mobile capacitor units with capacitors arranged in two unequal groups, the load on two transformers in open delta is reduced, regulation improved, voltage and current are balanced within operating limits, and with the aid of fans, the top oil temperatures — and consequently, the copper temperatures — are kept within safe limits. This permits proper loading of transformers in closed delta, a relatively short interruption to service or reduction in load upon failure of one transformer in a bank, and a reduction in number of transformers required for emergency use.
Comparison of Ca2+ and Mg2+ binding to calmodulin. An enthalpy, entropy, and gibbs free energy analysis

A consistent set of ΔG B , ΔH B , and ΔS B parameters have been determined from ion specific electrode, calorimetric, and spectrophotometric studies for the binding of Ca2+ and Mg2+ to bovine calmodulin at pH=7.0 and an ionic strength I of 0.113M. A non-linear least squares analysis of calcium specific ion electrode data yields, on a molar basis, four calcium dissociation constants: 10−7 for the first site, 10−5 for the fourth site, and two constants between these values. Both calorimetric experiments and an indicator method provide evidence that Mg2+ binds to calmodulin, probably at the same sites as Ca2+, but with affinities about 100 times smaller: 4×10−5 for the first site and 2×10−3 for the fourth. Calorimetric titrations on Ca2+ binding to calmodulin in three buffers are consistent with 0.46 protons released upon binding at all four sites and yield an average ΔH B per site of 5.6 and 7.9 kJ-mol−1 for Ca2+ and Mg2+, respectively. The entropy of the system increases by 524 and 361 J-K−1-mol−1 when Ca2+ and Mg2+, respectively, bind to four sites on calmodulin, i.e., the selectivity of calmodulin for Ca2+ is primarily derived from entropy effects. Further analysis based on elimination of the entropy term for the metal ions demonstrates that calmodulin bound to Ca2+ has a larger entropy than the unbound calmodulin; the opposite is true for calmodulin bound to Mg2+. These analyses are consistent with the hypothesis that Ca2+ forms tight complexes at all sites on calmodulin and that release of waters of hydration upon binding is the source of the increase of entropy in the system.
Clipping using homogeneous coordinates

Clipping is the process of determining how much of a given line segment lies within the boundaries of the display screen. Homogeneous coordinates are a convenient mathematical device for representing and transforming objects. The space represented by homogeneous coordinates is not, however, a simple Euclidean 3-space. It is, in fact, analagous to a topological shape called a “projective plane”. The clipping problem is usually solved without consideration for the differences between Euclidean space and the space represented by homogeneous coordinates. For some constructions, this leads to errors in picture generation which show up as lines marked invisible when they should be visible. This paper will examine these cases and present techniques for correctly clipping the line segments.
Pitfalls of contrast-enhanced imaging in the nervous system.

This brief review covers the evolving clinical role of paramagnetic contrast agents in magnetic resonance imaging of the central nervous system, with particular emphasis on potential pitfalls. The safety and efficacy of Gd-DTPA is now well-established. Approximately 35–40% of all scans performed in this country now utilize the agent. The major pitfalls center on overinterpretation of the characterization of disease by either enhancement or lack thereof in any particular process. © 1991 Academic Press, Inc.
Symmetries of Bernoulli polynomial series and Arakawa–Kaneko zeta functions

Abstract Text The Arakawa–Kaneko zeta functions interpolate the poly-Bernoulli numbers at the negative integers and their values at positive integers are connected to multiple zeta values. We give everywhere-convergent series expansions of these functions in terms of Bernoulli polynomials and Dirichlet series related to harmonic numbers, exhibiting their explicit analytic continuation. Differentiating the Barnes multiple zeta functions of order r with respect to their order produces Dirichlet series attached to Bernoulli polynomials. These series are invariant under an involution in which the order of the derivative is dual to the value of the first variable and the order of the zeta function is dual to the value of the second variable. This symmetry relation generalizes duality relations of Euler sums, and is featured in our series expansions of Arakawa–Kaneko zeta values. Video For a video summary of this paper, please visit http://youtu.be/0vQqfgrkX2k .
Spontaneous subdural haemorrhage in a child with bilateral middle cranial fossa arachnoid cysts

A 9-year-old previously healthy boy presented to the emergency room with a 3-week history of progressive headaches and intermittent vomiting without history of preceding trauma. The neurological examination was non-focal. A CT revealed a large, right-sided subdural haemorrhage of mixed signal intensity and a midline shift in the absence of superficial swelling or fracture (figure 1). Bilateral middle cranial fossa arachnoid …
Low sidelobe radar waveforms derived from orthogonal matrices

Novel waveforms are described that have low sidelobes when individual or multiple waveforms are approximately processed. They are related to orthogonal matrices that may be associated with complementary sequences and also with periodic waveforms having autocorrelation functions with constant zero-amplitude sidelobes. Also described are sets of sequences whose cross-correlation functions sum to zero everywhere. A potential application is the elimination of ambiguous range stationary clutter. >
Physiological aspects of vaginal contraception a review

Abstract Some aspects of vaginal contraception are briefly reviewed with particular reference to recent suggestions for new approaches to this method of conception control. Concepts pertinent to application for human use are stressed.
Evaluating Medical Students on Radiology Clerkships in a Filmless Environment

Abstract Rationale and Objectives The competency of medical students in radiology clerkships is traditionally evaluated with film images, projected slides of photographed films, or printed reproductions of films. As radiology departments switch to filmless imaging, it seemed appropriate to determine the feasibility of an electronic evaluation prepared directly from digital images. Materials and Methods The image-based portion of a multiple-choice final examination was prepared as a PowerPoint presentation that included images downloaded from the departmental picture archiving and communication system (PACS) or digital teaching collections. The images were downloaded as bitmap files, imported to Adobe Photoshop for image editing, converted to tagged image file format, and finally imported to PowerPoint, where they were combined with text to create 50 questions. A liquid crystal diode projector displayed the questions, with a timer set to advance them automatically. Results The examination was easy and inexpensive to prepare (no photography costs). In an initial survey of 25 students, 17 (71%) of 24 students rated the resolution of images as excellent and five (21%) as good. No student gave an image a poor rating. Students preferred that images cover at least 40%–50% of the slides, and most approved of a blue background. An original allowance of 30 seconds per slide was reported to be too fast; the interval was increased to 45 seconds. Conclusion An electronic final examination for medical students, prepared with images downloaded from PACS or digital teaching collections, is feasible, easy to prepare, and cost-effective, and it provides an excellent display of test images.
Extravasated erythrocytes, iron, and fibrin in atherosclerotic plaques of coronary arteries in fatal coronary heart disease and their relation to luminal thrombus: Frequency and significance in 57 necropsy patients and in 2958 five mm segments of 224 major epicardial coronary arteries

The presence of extravasated erythrocytes (EE), iron (I), and fibrin (F) within coronary atherosclerotic plaques and their relation to intraluminal coronary thrombus was determined in 2958 five-mm segments of 224 major epicardial coronary arteries in 57 patients with fatal coronary heart disease and in 1290 five-mm segments of 103 coronary arteries in 27 control (c) subjects. Intraplaque EE were present in 10% of the segments (controls [c] = 1%), in 35% of the arteries (c = 5%), and in 84% of the patients (c = 19%); I was present in 4% of the segments (c = less than 1%), in 14% of the arteries (c = 4%), and in 57% of the patients (c = 22%); intraplaque F was present in 2% of the segments (c = less than 1%), in 17% of the arteries (c = 3%), and in 63% of the patients (c = 7%). Intraluminal thrombus, present only in the patients with acute myocardial infarction and in none of the controls, occurred in 3% of the segments, in 8% of the arteries and in 26% of the patients. Intraplaque hemorrhage or EE occurred usually in the absence of intraluminal thrombus and conversely intraluminal thrombus occurred more frequently without than with underlying plaque hemorrhage. The frequency of intraplaque EE, I, and F was proportional to the amount of coronary atherosclerotic plaque present. Intraplaque I and F infrequently were observed in the absence of EE. The significance of extravasated erythrocytes, iron, and fibrin in atherosclerotic plaques remains unclear.
Developing a Quality and Safety Curriculum for Fellows: Lessons Learned From a Neonatology Fellowship Program

Formal training in health care quality and safety has become an important component of medical education at all levels, and quality and safety are core concepts within the practice-based learning and system-based practice medical education competencies. Residency and fellowship programs are rapidly attempting to incorporate quality and safety curriculum into their training programs but have encountered numerous challenges and barriers. Many program directors have questioned the feasibility and utility of quality and safety education during this stage of training. In 2010, we adopted a quality and safety educational module in our neonatal fellowship program that sought to provide a robust and practical introduction to quality improvement and patient safety through a combination of didactic and experiential activities. Our module has been successfully integrated into the fellowship program’s curriculum and has been beneficial to trainees, faculty, and our clinical services, and our experience suggests that fellowship may be particularly well suited to incorporation of quality and safety training. We describe our module and share tools and lessons learned during our experience; we believe these resources will be useful to other fellowship programs seeking to improve the quality and safety education of their trainees.
Nature of extra-atomic core-hole screening in ferromagnetic nickel.

Spin-resolved studies of Ni core-level photoemission are reported. The results indicate that the final-state Ni 3 $d$ electron configuration in not purely ${3d}^{10}$, in contradiction with early theories emphasizing complete $3d$-electron core-hole screening. A model is described in which extra-atomic screening involving unoccupied pure $3d$ states and unpolarized and hybridized $3d$- $4sp$ states leads qualitatively to a final-state $3d$ valence configuration of $\ensuremath{\sim}50%$ ${3d}^{9}$ and $\ensuremath{\sim}50%{3d}^{10}$. The relationship of these results to more recent theory employing the Anderson impurity model is discussed.
Crack-growth resistance of laminated hybrid SMC composites

The present work is aimed at characterizing the crack-growth behavior of hybrid composites having two different stacking sequences, namely; [C% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiaaigdadaWcba% WcbaGaaGymaaqaaiaaikdaaaaaaa!39AA!\[1\tfrac{1}{2}\]R/C/% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiaaigdadaWcba% WcbaGaaGymaaqaaiaaikdaaaaaaa!39AA!\[1\tfrac{1}{2}\]R/C] and [R/C/% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaamaaleaaleaaca% aIXaaabaGaaGOmaaaaaaa!38EF!\[\tfrac{1}{2}\]R/C/% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaamaaleaaleaaca% aIXaaabaGaaGOmaaaaaaa!38EF!\[\tfrac{1}{2}\]R/C/R]. The letter C in these hybrids represents a 50% weight fraction continuous fiber composite layer while the R represents a 50% weight fraction randomly oriented chopped fiber composite layer. The standard compact tension specimens having notches oriented along and perpendicular to the fiber direction of the C layers were chosen. The flexural strength is purported to be an adequate parameter for crack-growth characterization in the cases where the observed crack-growth was in the direction perpendicular to the notch direction. For the cases of self-similar crack-growth, the measured fracture resistance was found to be lower than that predicted by a proposed rule-of-mixture relationship based upon the crack-energy release rates of the C layers and R layers.
The effect of particle size on fourier-transform infrared photoacoustic spectra

Abstract The effect of particle size on infrared photoacoustic spectra has been investigated by use of naturally occurring quartz. It is observed that the PAS peak intensities increase with a decrease in particle diameter and that the peak intensity ratios are not constant for particles of different diameters. When the particle diameter becomes smaller than the thermal diffusion length for a specific peak, a more dramatic increase in peak intensity is observed. It is also found that the PAS peak shape deteriorates with an increase in particle diameter. The effect of optical velocity of the interferometer on PAS peak intensities is also reported.
The effect of locus of control on communication motivation, anxiety, and satisfaction

Uses and gratifications is a psychological communication perspective focusing on how individual differences mediate attitudes and behavior. Incorporated in the perspective is an implicit emphasis of the interface of personal and mediated communication. As a salient psychological trait, locus of control should affect communication motivation and tendencies. Based on internal vs. external locus of control, we expected differences in communication motivation in interpersonal and mass‐media contexts, and differences in one's communication anxiety and satisfaction. Multivariate analysis of variance supported our expectations. Externals found communication to be less rewarding and less satisfying, tended to avoid communication, and were motivated to communicate more ritualistically than internals. We discussed these findings.
Activation of the retinoblastoma tumor suppressor mediates cell cycle inhibition and cell death in specific cervical cancer cell lines

High-risk human papilloma virus (HPV) encodes two oncoproteins, E6 and E7, which are vital to viral replication and contribute to the development of cervical cancer. HPV16 E7 can target over 20 cellular proteins, but is best known for inactivating the retinoblastoma (RB) tumor suppressor. RB functions by restraining cells from entering S-phase of the cell cycle, thus preventing aberrant proliferation. While it is well established that HPV16 E7 facilitates the degradation of the RB protein, the ability of the RB pathway to overcome E7 action is less well understood. In this study the RB-pathway was activated via the overexpression of the p16ink4a tumor suppressor or ectopic expression of an active allele of RB (PSM-RB). While p16ink4a had no influence on cell cycle progression, PSM-RB expression was sufficient to induce a cell cycle arrest in both SiHa and HeLa cells, HPV positive cervical cancer cell lines. Strikingly, this arrest led to the downregulation of E2F target gene expression, which was antagonized via enhanced HPV-E7 expression. Since downmodulation of E7 function is associated with chronic growth arrest and senescence, the effect of PSM-RB on proliferation and survival was evaluated. Surprisingly, sustained PSM-RB expression impeded the proliferation of SiHa cells, resulting in both cell cycle inhibition and cell death. From these studies we conclude that active RB expression can sensitize specific cervical cancer cells to cell cycle inhibition and cell death. Thus, targeted therapies involving activation of RB function may be effective in inducing cell death in cervical cancer.
High-flux source of polarization-entangled photons from a periodically poled KTiOPO 4 parametric down-converter

We have demonstrated a high-flux source of polarization-entangled photons using a type-II phase-matched periodically poled ${\mathrm{KTiOPO}}_{4}$ parametric down-converter in a collinearly propagating configuration. We have observed quantum interference between the single-beam down-converted photons with a visibility of 99% together with a measured coincidence flux of $300{\mathrm{s}}^{\ensuremath{-}1}/\mathrm{mW}$ of pump. The Clauser-Horne-Shimony-Holt version of Bell's inequality was violated with a value of $2.711\ifmmode\pm\else\textpm\fi{}0.017.$
Caching and other disk access avoidance techniques on personal computers

CPU processing speed is rapidly increasing on PCs, resulting in a widening gap between disk access and CPU speed. The performance of three common disk caching systems are examined in an effort to determine a technique for reducing the gap.
Testing for imbalance of covariates in controlled experiments

Results of a controlled experiment are often adjusted for covariates found by a preliminary test to differ significantly between the treatment and control groups. The resulting test's true significance level is lower than the nominal level. Greater power can be achieved by always adjusting for a covariate that is highly correlated with the response regardless of its distribution between groups.
Bleomycin regulation of transforming growth factor-beta mRNA in rat lung fibroblasts.

Pulmonary fibrosis is a well-known toxic response to bleomycin treatment. Here we demonstrate the direct effects of bleomycin on lung fibroblasts that resulted in a marked increase of collagen synthesis as compared with total noncollagen protein synthesis. Bleomycin treatment of rat lung fibroblast cultures resulted in an increase of total cellular transforming growth factor-β (TGF-β) mRNA and increased secretion of TGF-β protein into the conditioned media. β2-Microglobulin was measured as an mRNA that did not increase with bleomycin treatment. The bleomycin-induced increase of TGF-β mRNA was decreased by cells cultured in the presence of either cycloheximide, an inhibitor of protein synthesis, or 2-mercapto-1-(β-4-pyridethyl) benzimidazole, an inhibitor of RNA synthesis. To assess the mechanism underlying increased steady-state mRNA levels, the nuclear fraction was isolated from bleomycin-treated cells and the TGF-β transcripts were determined. Transcription of TGF-β mRNA was increased 12 h after bleomyc...
Inate immunity: Turning off natural killers

Inhibitory receptors specific for class I molecules of the major histocompatibility complex regulate the cytolytic activity of natural killer cells. Recent studies suggest that recruitment of the protein tyrosine phosphatase SHP-1 enables these receptors to block natural killing.
Fluorescence quenching of methyl‐2‐aminobenzoate in the presence of beta‐cyclodextrin: A model for the dynamic quenching of chromophores in hydrophobic regions of biopolymers

The binding constant of methyl-2-aminobenzoate to beta-cyclodextrin was determined by fluorescence titration to be 92.1M−1 at 25°C in pH 7 buffer. Beta-cyclodextrin dramatically protects methyl-2-aminobenzoate against quenching by iodate and protects, though much less efficiently, against the smaller quencher, iodide. The observed decrease in fluorescence lifetime of the methyl-2-aminobenzoate-beta-cyclodextrin complex on addition of quencher indicates that the quenching mechanism is collisional (dynamic). The dependence of quenching rate on solvent viscosity is less than expected from simple theoretical considerations. However, the extent of beta-cyclodextrin protection is essentially viscosity-independent. These model studies show the usefulness of iodate as a quencher and encourage further attempts at quantitative interpretation of quenching studies on chromophores attached to biopolymers.
Hepatic progenitors and strategies for liver cell therapies

: Liver cell therapies, including liver cell transplantation and bioartificial livers, are being developed as alternatives to whole liver transplantation for some patients with severe liver dysfunction. Hepatic progenitors are proposed as ideal cells for use in these liver cell therapies given their ability to expand extensively, differentiate into all mature liver cells, have minimal immunogenicity, be cryopreservable, and reconstitute liver tissue when transplanted. We summarize our ongoing efforts to develop clinical programs of hepatic progenitor cell therapies with a focus on hepatic stem cell biology and strategies that have emerged in analyzing that biology.
An incremental brake force protocol for arm crank anaerobic testing of wheelchair athletes

The traditional Wingate anaerobic test (WAnT) paradigm of setting cycle brake resistance relative to body weight has limited value in a lower limb impaired population. The purpose of this investigation is to define a loading scheme that elicits optimal performance of a wheelchair athlete on a WAnT using the Monark 881 arm‐crank ergometer. Seventeen elite male wheelchair basketball athletes performed a randomized series of 30 second WAnTs at four absolute brake force loads (3.50, 4.25, 5.00, and 5.75 kg) and an additional single 10 second maximal velocity WAnT using a 3.00kg load. A repeated measures ANOVA identified a significant difference in peak power {p < .01, F(3,47) = 25.46} and in mean power output {p < .01, F(3, 47) = 30.39} attributable to the variation in load. Post hoc analysis indicated that the mean optimal load for this elite group was the highest load examined. The relationship of each individual's optimal load with peak performance (average revolutions/minute for the peak 3 seconds) on a. ...
Trading Blocs and the Capitalist World‐Economy: Insights and Evidence

The structure of the world-economy is a central issue in world-systems research. Empirical structural analysis, however, has generally focused on a single structural aspect of the world-system: delineation of the core, periphery, and semiperiphery. This study examines another important structural facet of the world-system-blocs within the world trading order. The existence of blocs within the world-economy, as well as their configuration, have implications for states at all structural positions of the world system. Analysis of blocs which exist among core states can provide insights into issues of hegemonic cycles and decline. Outside of the core, the character of clusters can provide evidence regarding peripheral mobility, fragmentation, or subimperialism. Employing two complementary network methods, asymmetric multidimensional scaling and clique detection, this study examines blocs within the world-economy at three points since World War II: 1955, 1975, and 1994. Results indicate a somewhat multipolar, though not necessarily antagonistic, core and a somewhat fragmented periphery.
Cascade of Transitions of Polyelectrolytes in Poor Solvents

We develop a scaling model for the dilute solution conformation of a uniformly charged polymer in a poor solvent. We find that there is a range of temperatures and charge densities for which the polymer has a necklace-like shape with compact beads joined by narrow strings. The free energy of a polyelectrolyte in this conformation is lower than in a cylindrical globule because the length of the necklace is larger than that of a cylinder and is proportional to the total charge on the chain. With changing charge on the chain or temperature, the polyelectrolyte undergoes a cascade of abrupt transitions between necklaces with different numbers of beads.
A Semiparametric Correction for Attenuation

Abstract A correction method is proposed for models including the generalized linear model when the covariate is measured with error. The method requires a separate validation data set that consists of the surrogate W and the true covariate X or an unbiased estimate X⊃ of X. We do not require the classical additive measurement error model in which the surrogate is unbiased for the true covariates. We first obtain an estimate of E(X|W) by using nonparametric kernel regression of X or X⊃ on W based on the validation data. Then we perform a standard analysis with the unknown X replaced by the estimate of E(X|W). The asymptotic distribution of the resulting regression parameter estimator is obtained. Generalizations to include components of X measured without error are also discussed.
Soil wetting agents from fatty nonionic tertiary amides: “Aromatic adducts without aminoester”

Tertiary amides RCONR'K, where K is a hydroxy function and R,R′ are aliphatic and/or aromatic groups, were oxyethylated to adducts containing 5, 10, 15, and 20 moles of ethylene oxide. The hydroxy function K was derived from CH2CHR″OH,-(CH2)yOH, or (CH2CH2O)zH, where R″ is methyl, ethyl, or octyl, y is 4 or 6 methylenes, and z is 2 or 3 ethoxy groups. Structural variations in R,R′ and K permitted the oxyethylation of aromatic amides with minimal aminoester formation. When K was diethoxy and R,R′ were linear aliphatic groups, no aminoester accompanied oxyethylation. Minimal aminoester formed when R,R′ were mixed aliphatic/ aromatic or when R was phenethyl and R′ aromatic. For aromatic amides where K was dior triethoxy, large aminoester concentrations accompanied oxyethylation. For aromatic amides where K was (CH2)4OH or (CH2)6OH smaller aminoester concentrations were observed. For branched alphatic amides where R″ is methyl, ethyl, or octyl, aminoester concentration remained at the level found where R″ is hydrogen. The increasing size of R″ decreased solubility and Draves wetting times. The adducts of this study were wetting agents for Idylwild hydrophobic soil and cotton skeins. The availability of aromatic substrates should permit formulation of soil wetting agents with greater stability to biodegradation than would be expected with aliphatic substrates.
Anthocyanins in Royalty Grapes

SUMMARY The anthocyanins of Royalty grapes were extracted with methanol containing 0.1% HCI and purified by adsorption on cation-exchange resin, and the individual pigments separated by paper chromatography. Acid hydrolysis and chromatographic characteristics provided information on the nature of the acyl and sugar moieties of the anthocyanins. The anthocyanins were identified by their Rf values, sugar moiety, alkaline-degradation products of the anthocyanidins, partial acid hydrolysis, and spectral characteristics in the visible and ultraviolet regions. The pigments, in decreasing order of concentration, were malvidin-3,5-diglucoside, malvidin-3,5-diglucoside acylated with p-coumaric acid, malvidin-3-monoglucoside acylated with p-coumaric acid, malvidin-3-monoglucoside, peonidin-3,5-diglucoside, malvidin-3,5-digluco-side acylated with caffeic acid, peonidin-3-monoglucoside, peonidin-3-monoglucoside acylated with i)-coumaric acid, and peonidin-3,5-diglucoside acylated with p-coumaric acid. The presence of 3-glucosides of cyanidin, delphinidin, and petunidin, and 3,5-diglucoside of petunidin is indicated.
Vaginal hygiene and douching: perspectives of Hispanic men

Vaginal douching is widely practised by women in the USA, particularly among minority ethnic groups, and is associated with increased risk of pelvic and vaginal infections. Douching practices are shaped by social and cultural norms regarding female hygiene, reproduction and sexuality. Little previous research has addressed the beliefs and practices of Latina women and none has included the perspective of men, though limited data suggests that women may douche to please male partners. The present study seeks to identify the socially and culturally shaped beliefs and attitudes that influence douching practices from the perspective of Latino men. We conducted in-depth qualitative interviews in English or Spanish with adult Latino men seeking primary care at a community health centre in New York City. Results indicate that these Latino men (mostly of Caribbean descent) are emphatic about the role of cleanliness in vaginal health, reporting that it substantially influences their choice of partner. Most are very supportive of douching, which they consider a necessary hygiene activity. Vaginal health is perceived as a state that must be attained and maintained through proactive hygiene measures that remove seminal residue, menstrual blood, sweat and bacteria that contaminate the vagina. The implications of these findings for interventions with Latina women are discussed.
Heavy metals in stream sediments: Effects of human activities

The content of 11 heavy metals in the sediments of a stream system was determined by atomic absorption analysis. Geochemical phases were investigated using a sequential extraction scheme, and bulk contents were assessed with a single HNO3 extraction. Certain heavy metals were associated with different geochemical phases. Co, Mn, and Ba concentrated primarily in the carbonate and Mn phases, while all the remaining metals concentrated in the Fe and remnant phases. Features located along the stream system influenced the content of heavy metals. Results from the geochemical phases indicated Cu, Pb, Zn, Cd and Ag were emitted by one landfill, while Cd, Ba, and Ag were emitted by a second landfill. A wastewater treatment facility appeared to emit Ni and Cu. A stream draining a reservoir and joining the study stream resulted in dilution of the heavy metals in the sediments. A populated area along the study stream appeared to emit Mn. The single HNO3 extraction procedure is quicker to perform than the sequential extraction but does not indicate the phase associations.
Preferential taxation and the control of urban sprawl: An analysis of the California Land Conservation Act

The premature conversion of agricultural lands to urban use has concerned many persons, especially when urban sprawl results. In an effort to reduce such premature conversion California offers reduced property taxation to landowners who sign a contract to give up development rights to their property for a specified period. The California program is described and the potential economic benefits, measured as the present value of the tax savings, are calculated. Using these values, the conditions under which acceptance of a contract is preferred to nonacceptance are analyzed. The implications of the results for program effectiveness and land use control policy are discussed.
Low concentrations of inorganic mercury inhibit Ras activation during T cell receptor-mediated signal transduction.

Mercury is widespread in the environment and consequently there are large populations that are currently exposed to low levels of mercury as a result of ubiquitous environmental factors. Whether these environmental levels of mercury are harmful is a matter of current debate, with epidemiological and animal studies suggesting detrimental effects on the immune and nervous systems. However, specific cellular effects of low concentrations of mercury have been hard to characterize. We now demonstrate that subtoxic concentrations of HgCl(2) can potently (maximal at 1 microM) increase Ras.GTP levels in Jurkat, a human T cell line. Remarkably, this activation of Ras occurs without a concomitant increase in MAP kinase activation, suggesting that mercury may direct Ras into a nonproductive state. In addition to its direct effect on Ras, concentrations of HgCl(2) as low as 0.6 microM inhibited the ability of the T cell receptor to activate Ras and MAP kinase. The inhibitory effect of mercury is selective, as activation of MAP kinase by phorbol diesters remain intact. Since the Ras/MAP kinase pathway is both highly conserved and central to signal transduction processes mediated by a myriad of diverse membrane receptor systems in a variety of cell types, these results suggest a mechanism for adverse health effects resulting from exposure to low levels of mercury. They also support a model for regulation of the Ras/MAP kinase pathway, whereby partial but unproductive activation of Ras can diminish signaling from cell surface receptors.
An investigation of the color-affect hypothesis in Exner's comprehensive system

The color-affect hypothesis states that color responses on the Rorschach provide information regarding an individual's emotional life. The present study explored the several color-affect interpretive hypotheses in Exner's popular Comprehensive System by using a theory-relevant measure of affective modulation inferred from 32 undergraduates' behavior in an emotionally salient dyadic interaction. Subjects designated as high affective modulators (n = 6) and low affective modulators (n = 10) according to Exner's theory were not significantly different on a discrepancy score measure of affective modulation. It is suggested that Rorschach color scores may be insensitive to the more subtle forms of affective modulation present in less emotionally disordered individuals. Further research is suggested and caution is advised for clinicians assessing affective modulation styles in less severely disturbed patients based on traditional color-affect interpretive theory.
A survey of Petri net applications in modeling controls for automated manufacturing systems

Abstract Recent literature on Petri net applications to model controls of automated manufacturing systems is discussed. Modeling controls is essential to prevent the incidence of system deadlock which could possibly occur due to the concurrent and asynchronous nature of activities. It is difficult to implement an efficient programmable logic controller program for a manufacturing plan without solving this problem. Research findings on control model generation and analysis are discussed in the light of the deadlock problem and performance evaluation. Past and present research in these areas is critically examined in an attempt to focus on the guidelines for on-going research in control modeling.
The Importance of the Transition Metal Volume in A15 Superconductors

It has been suggested1,2 that an essential feature of superconductors with a high transition temperature Tc is that the system be on the verge of a lattice instability. Testardi et al.3,4 have also argued that the high transition temperatures in some Al5 superconductors, notably V3Si, are related to their low-temperature lattice instabilities. We are currently investigating the superconducting properties under pressure of A15 superconductors of the type T1−y X y , where T is a transition metal atom and X is a simple metal exhibiting s—p bonding. In general, these systems form a single well-defined Al5 phase over a range of composition 0.2 0≲ y ≦ 0.25. For y > 0.25 the V—Si system has a two-phase region of (V3Si + V5Si3). The change in T c produced by the application of hydrostatic pressure can be of either sign in these systems. Likewise, the lattice parameter increases in some systems and decreases in others as one alloys away from the stoichiometric compound at y = 0.25 in the single-phase A 15 region. In investigating these systems, we have noted a strong correlation between the sign of dT c / dP and the sign of the lattice parameter change as one approaches the stoichiometric compound. For example, in V3Si the volume decreases with a decrease in the amount of excess V,5 and dT c / dP is positive.6 This behavior is contrary to that predicted by Testardi,4 who calculates a large quadratic strain dependence for T c This would give a rapid depression of T c with pressure. We do not believe that the correlation is coincidental and are currently investigating the changes in T c produced by changing the transition metal atom spacing. Smith6 has observed a particularly large increase in T c with pressure (1°K per 29 kbar) for the A15 compound V3Si. Since this compound is thought to be on the verge of a lattice instability, it is useful to determine if the occurrence of some phase transition in V3Si might limit the increase in T c attainable by the application of pressure. Hence we are studying the compressibility and phase stability of V3Si at pressures up to 300 kbar. Preliminary results of this study are reported here.
Dual potential of microalgae as a sustainable biofuel feedstock and animal feed

The rise in global population has led to explorations of alternative sources of energy and food. Because corn and soybean are staple food crops for humans, their common use as the main source of dietary energy and protein for food-producing animals directly competes with their allocation for human consumption. Alternatively, de-fatted marine microalgal biomass generated from the potential biofuel production may be a viable replacement of corn and soybean meal due to their high levels of protein, relatively well-balanced amino acid profiles, and rich contents of minerals and vitamins, along with unique bioactive compounds. Although the full-fatted (intact) microalgae represent the main source of omega-3 (n-3) polyunsaturated fatty acids including docohexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the de-fatted microalgal biomass may still contain good amounts of these components for enriching DHA/EPA in eggs, meats, and milk. This review is written to highlight the necessity and potential of using the de-fatted microalgal biomass as a new generation of animal feed in helping address the global energy, food, and environmental issues. Nutritional feasibility and limitation of the biomass as the new feed ingredient for simple-stomached species are elaborated. Potential applications of the biomass for generating value-added animal products are also explored.
Summer irrigation, grazing and seed addition differentially influence community composition in an invaded serpentine grassland

Community assembly theory predicts that resource availability, biotic interactions, and dispersal dynamics will determine community composition. Recent work has demonstrated that manipulating these processes or “filters” to exclude exotic species may assist in restoring invaded plant communities. In this study, we began by manipulating an abiotic filter, summer water availability, on the theory that irrigation prior to the growing season could trigger the germination of exotic species during unfavorable environmental conditions. First, we performed a greenhouse experiment to assess the germination traits of 23 native and exotic species at low (16°C, spring) and high (30°C, summer) temperatures. At summer temperatures, we found high emergence of many exotic and native grasses and low emergence of native forbs suggesting that summer irrigation may help deplete the exotic seed bank. In a second experiment, we established field plots to test the efficacy of summer irrigation and simultaneously manipulated a biotic and a dispersal filter, subjecting some plots to grazing and/or native seed addition. Summer irrigation and seed addition had no effect on percent cover or species richness while grazing reduced native cover but increased native species richness and soil nitrogen content. Our data suggest that manipulating grazing (a biotic filter) may be more effective than altering abiotic or dispersal filters when restoring invaded serpentine grassland. However, summer irrigation may also be effective, if applied at lower temperatures or for longer periods.