cssi/SciSciGPT-SciSciNet huggingface dataset:
Determination of Extractant Solubility in Ionic Liquids by Thermogravimetric Analysis

ABSTRACTThe high thermal stability typical of many room temperature ionic liquids (RTILs) is exploited as the basis of a method employing thermogravimetric analysis (TGA) for the determination of the solubility of various metal ion extractants in these solvents. The approach is simple, applicable to extractants lacking functional groups that would permit their ready quantification by other methods, and requires only small (mg) quantities of sample. These features of the method, along with its limitations, are illustrated by the determination of the solubility of representative examples of several common extractant families, including bis(2-ethylhexyl)phosphoric acid (HDEHP) and di-tert-butylcyclohexano-18-crown-6 (DtBuCH18C6), in a series of 1,3-dialkylimidazolium (Cnmim+)-based ionic liquids.
Ca2+ and Myosin Cycle States Work as Allosteric Effectors of Troponin Activation.

Abstract In cardiac muscle, troponin (Tn) and tropomyosin inhibit actin and myosin interactions through the steric blocking of myosin binding to F-actin. Ca2+ binding to Tn C modulates this inhibition. Thin filaments become activated upon Ca2+ binding, which enables strong binding of myosin with a concomitant release of ATP hydrolysis products and level arm swinging responsible for force generation. Despite this level of description, the current cross-bridge cycle model does not fully define the structural events that take place within Tn during combinatorial myosin and Ca2+ interventions. Here, we studied conformational changes within Tn bound to F-actin and tropomyosin by fluorescence lifetime imaging combined with Forster resonance energy transfer. Fluorescent dye molecules covalently bound to the Tn C C-lobe and Tn I C-terminal domain report Ca2+- and myosin-induced activation of Tn. Reconstituted thin filaments were deposited on a myosin-coated surface similar to an in vitro motility assay setup without filament sliding involved. Under all the tested conditions, Ca2+ was responsible for the most significant changes in Tn activation. Rigor myosin activated Tn at subsaturated Ca2+ conditions but not to the degree seen in thin filaments with Ca2+. ATP-γ-S did not affect Tn activation significantly; however, blebbistatin induced significant activation at subsaturating Ca2+ levels. The relation between the extent of Tn activation and its conformational flexibility suggests that active/inactive Tn states coexist in different proportions that depend on the combination of effectors. These results satisfy an allosteric activation model of the thin filament as a function of Ca2+ and the myosin catalytic cycle state.
Conformal Defect Solutions in $N=2,D=4$ Gauged Supergravity

Author(s): Gutperle, Michael; Vicino, Matteo | Abstract: We consider conformal defect solutions in four dimensional $N=2$ gauged supergravity. These solutions are constructed as a warped product of $AdS_2\times S^1$ over an interval with non-trivial electric and magnetic fields. We show for minimal gauged supergravity and for gauged supergravity with vector multiplets and abelian gauging that supersymmetric defect solutions are only possible when the geometry has a conical defect in either the bulk or the boundary metric.
The Story of Industrial Engineering: The Rise from Shop-Floor Management to Modern Digital Engineering

Recipient of the 2020 IISE Institute of Industrial and Systems Engineers Joint Publishers Book-of-the-Year Award Industrial engineering is the profession dedicated to making collective systems function better with less waste, better quality, and fewer resources, to serve the needs of society more efficiently and more effectively. This book uses a story-telling approach to advocate and elaborate the fundamental principles of industrial engineering in a simple, interesting, and engaging format. It will stimulate interest in industrial engineering by exploring how the tools and techniques of the discipline can be relevant to a broad spectrum of applications in business, industry, engineering, education, government, and the military. Features Covers the origin of industrial engineering Discusses the early pioneers and profiles the evolution of the profession Presents offshoot branches of industrial engineering Illustrates specific areas of performance measurement and human factors Links industrial engineering to the emergence of digital engineering Uses the author’s personal experience to illustrate his advocacy and interest in the profession
Chapter 1 – Historical Antecedents

The study of traumatic brain injury has exploded over the last 25 years. Within this chapter we will introduce the current terminology, general history, and current research trends of traumatic brain injury. First, we will describe the types of brain injuries to be discussed in this book. Next, we will examine the historical antecedents in the study and treatment of traumatic brain injury, from antiquity to now. Finally, we will close with a brief overview of the current treatment options following traumatic brain injury including sex differences in traumatic brain injury and the use of steroid hormones including estrogens as a treatment option.
Will Deep Learning Change How Teams Execute Big Data Projects

As data continues to be produced in ever increasing quantities, and technologies such as high performance computing continue to be enhanced, the number of big data projects using advanced neural network machine learning, often referred to as deep learning, continues to increase. Unfortunately, while much has been written on the use of deep learning algorithms in terms of generating insightful analysis, much less has been written about the project management process methodologies that could enable teams to more effectively and efficiently "do" big data deep learning projects. Specifically, the rapid growth in the use of deep learning techniques might introduce new challenges with respect to how to execute a big data deep learning project, due to how deep learning models can learn features automatically. For example, feature engineering and model evaluation phases of big data projects might grow in importance, while other areas, such as model selection, might decrease in importance. Hence, this paper discusses the key research questions relating the potential impact of the use of deep learning on how teams should execute big data projects.
Studies in Enterprise, 1960 A Selected Bibliography

This third annual bibliography has essentially the same coverage as that of last year. It includes selected histories of industries, histories of specific corporate functions, episodes in the history of companies, and histories of trade associations, as well as over-all histories of companies and biographies of businessmen. Although still limited geographically to the United States and Canada, several bibliographies of British, German, and Japanese company histories are included under the heading “Business History, Foreign — Bibliography.”
Metamorphic Belts of North America

There is a wide Precambrian craton in the northern and central parts of North America. Precambrian granitic and metamorphic rocks are exposed in the northern part, which is called the Canadian Shield, whereas these rocks are covered by relatively thin, undisturbed, unmetamorphosed Phanerozoic sediments in the central part, which is usually called the Interior Lowlands (fig. 13–1).
Basic Research Means Challenging the Unknown: Study, work, frustration, and success add up to basic research

The concept of what constitutes basic (or fundamental) research seems to depend upon the person involved, whether he be industrial executive, research director, legislator, director of a government bureau or agency, or the research scientist himself. Indeed, it varies greatly among scientists. A university professor may have one idea, a young scientist beginning his industrial career another, and the seasoned industrial scientist still another. To learn whether a career in basic research holds promise for the kind of life a man wants for himself and his family, he should inquire what this term connotes in each major kind of establishment in which he might be employed. It is also important to consider the avenues for advancement as well as the opportunities to transfer to other types of work in the event that he should desire to do so. A few people assume that basic research can be taken to mean work done by a research ...
Abstract P235: Racial/ethnic and Geographic Disparities in Cardiovascular Health Among Pregnant Women in The United States

Life’s Simple 7 (LS7) developed by the American Heart Association (AHA) reframes cardiovascular disease (CVD) into terms of cardiovascular health (CVH). Large disparities in CVH exist in the genera...
Interaction of a solitary wave with an array of macro-roughness elements in the presence of steady currents

Abstract The present study focuses on the effects of following and opposing steady currents on the interactions of a solitary wave with an array of macro-roughness elements, placed on a berm beach. A series of laboratory experiments and high-fidelity numerical simulations are conducted. The large eddy simulations are carried out using the open source computational fluid dynamics package, OpenFOAM. Wave breaking conditions on the berm are found to be controlled by the intensity of the currents. The opposing currents influence the layer of water rushing up the macro-roughness elements, leading to asymmetric runup patterns. Furthermore, the vortices forming around the elements' sharp edges, resulting from the interactions of the wave with the elements, are modified to a large extent due to the combined wave and current effect. The elliptical vortex tubes become up to ~ 20% wider under the effect of the following current flow, whereas their size is reduced by up to ~ 90% when the opposing currents are present. The following currents enhance the bed shear velocity, leading to intensified bed shear stress zones throughout the macro-roughness environment. On the other hand, the intensification of the bed shear velocity and corresponding stress occurs on the seaside in the presence of opposing currents. Overall, the results indicate that the currents entirely change the hydrodynamics of the interactions between the solitary wave and macro-roughness environment.
Particles on AdS4/7 and primary operators on M2/5 brane worldvolumes

I identify a correspondence between the various spherical harmonic modes of massless 11 dimensional fields propagating on the AdS4/7 in an AdS4/7 × S7/4 compactification of M theory, and the corresponding operators, primary under the conformal group, on the world volume of the M2,M5 branes. This is achieved by matching representations of the superconformal algebra on the two sides of the correspondence.
Impact of hospital transfer on testicular torsion outcomes: A systematic review and meta-analysis.

Summary Introduction Testicular torsion is an emergent condition requiring prompt treatment. Previous studies have suggested transfer of pediatric testicular torsion cases may be detrimental to patient outcomes. Findings have not reached statistical significance. No study has quantitatively analyzed all literature reporting outcomes for transferred torsion patients. The aim of this study was to elucidate the impact of hospital transfer on pediatric testicular torsion outcomes through a systematic review and meta-analysis. Methods A predefined study protocol registered with PROSPERO was developed according to PRISMA. A comprehensive literature review of articles investigating outcomes for pediatric testicular torsion for transferred and non-transferred (treated “directly” at presentation institution) patients with orchiectomy as the primary outcome was conducted by systematically searching PubMed and Embase. Potential studies were screened against a predefined study protocol. Meta-analysis using a random effects model with transferred status as the “intervention” was performed using Review Manager 5.3. Results Of 18 eligible studies, 9 retrospective studies comprised of 2564 patients (532 transferred and 2032 direct) were suitable for quantitative analysis. Main analysis showed transfer status does not have a significant effect on torsion outcomes (RR 0.96 [95% CI 0.78–1.17]; I2 = 44%). Subgroup analysis for torsion patients presenting within 24 h of symptom onset shows patients who are transferred to another facility for management are more likely to undergo orchiectomy than those treated at their presenting institution (RR 0.35 [95% CI 0.24–0.51]; I2 = 4%). Conclusions In this meta-analysis, hospital transfer does not affect orchiectomy rate in pediatric patients with testicular torsion when pooling data from all presentation timeframes. Subgroup analysis of patients presenting with testicular torsion in an acute setting (
The Role of Dynamic Capabilities in Firm-Level Technology Adoption Processes: A Qualitative Investigation

Increasingly, marketers rely on advances in technology to maintain competitive parity or gain competitive advantage. Yet, often, the adoption of technology is met with suboptimal results and even outright failure. Qualitative field research based on depth interviews with business managers responsible for technology adoption decisions within their respective firms is used to develop a theoretical framework explaining the technology adoption process within firms, how expectations are formed for the innovation’s performance and factors that can further influence those perceptions. Result suggest a firm’s dynamic capabilities play a central role in informing the firm’s perceptions of a technological innovation’s characteristics that drive the adoption decision. Findings also suggest that a firm’s expectations are influenced by perception of risk, internal micro-political actions, and the opportunity to observe or trial use of the technological innovation.
Applying Machine Learning to Classify the Origins of Gene Duplications

Nearly all lineages of land plants have experienced at least one whole genome duplication (WGD) in their history. The legacy of these ancient WGDs is still observable in the diploidized genomes of extant plants. Genes originating from WGD--paleologs--can be maintained in diploidized genomes for millions of years. These paleologs have the potential to shape plant evolution through sub- and neofunctionalization, increased genetic diversity, and reciprocal gene loss among lineages. Current methods for classifying paleologs often rely on only a subset of potential genomic features, have varying levels of accuracy, and often require significant data and/or computational time. Here we developed a supervised machine learning approach to classify paleologs from a target WGD in diploidized genomes across a broad range of different duplication histories. We collected empirical data on syntenic block sizes and other genomic features from 27 plant species each with a different history of paleopolyploidy. Features from these genomes were used to develop simulations of syntenic blocks and paleologs to train a gradient boosted decision tree. Using this approach, Frackify (Fractionation Classify), we were able to accurately identify and classify paleologs across a broad range of parameter space, including cases with multiple overlapping WGDs. We then compared Frackify with other paleolog inference approaches in six species with paleotetraploid and paleohexaploid ancestries. Frackify provides a way to combine multiple genomic features to quickly classify paleologs while providing a high degree of consistency with existing approaches.
Prostatic Ductal Adenocarcinoma Controlled for Tumor Grade, Stage, and Margin Status Does Not Independently Influence the Likelihood of Biochemical Recurrence in Localized Prostate Cancer After Radical Prostatectomy

Context.— Prostatic ductal adenocarcinoma (PDA) has historically been considered to be an aggressive subtype of prostate cancer. Objective.— To investigate if PDA is independently associated with worse biochemical recurrence (BCR)-free survival after radical prostatectomy. Design.— A review of 1584 radical prostatectomies was performed to grade, stage, and assess margin status in each tumor nodule. Radical prostatectomies with localized PDA (ie, those lacking metastasis) in the tumor nodule with the highest grade and stage and worst margin status were matched with prostatic acinar adenocarcinoma according to grade, stage, and margin status. The effect of PDA on BCR was assessed by multivariable Cox regression and Kaplan-Meier analyses. Results.— Prostatic ductal adenocarcinoma was present in 171 cases. We excluded 24 cases because of lymph node metastasis (n = 13), PDA not in the highest-grade tumor nodule (n = 9), and positive surgical margin in a lower-grade tumor nodule (n = 2). The remaining 147 cases included 26 Grade Group (GG) 2, 44 GG3, 6 GG4, and 71 GG5 cancers. Seventy-six cases had extraprostatic extension, 33 had seminal vesicle invasion, and 65 had positive margins. Follow-up was available for 113 PDA and 109 prostatic acinar adenocarcinoma cases. Prostate-specific antigen density (odds ratio, 3.7; P = .001), cancer grade (odds ratio, 3.3-4.3; P = .02), positive surgical margin (odds ratio, 1.7; P = .02), and tumor volume (odds ratio, 1.3; P = .02) were associated with BCR in multivariable analysis. Prostatic ductal adenocarcinoma, its percentage, intraductal carcinoma, and cribriform Gleason pattern 4 were not significant independent predictors of BCR. Conclusions.— Advanced locoregional stage, higher tumor grade, and positive surgical margin status rather than the mere presence of PDA are more predictive of worse BCR-free survival outcomes following radical prostatectomy in men with a component of PDA.
For and against equal access to health care.

There is a fairly widespread consensus among empirical analysts that access to health care in this country has become more equal in the last quarter century. Agreement tends to end here, and debate ensues as to whether this trend will or should persist. But before debating these questions, we ought to have a clear idea of what equal access to health care means. Since we cannot define equality of access to health care in a morally neutral way, we must choose a definition that is morally loaded with a set of values.1 The definition offered here is by no means the only one possible. It has, however, the advantage not only of clarity but also of embedding within it strong and commonly accepted liberal egalitarian values. The debate is better focused upon arguments for and against a strong principle of equal access than on disputes over definitions, which tend to hide fundamental value disagreements instead of making them explicit.
Computer Implementation of the Absolute Nodal Coordinate Formulation for Flexible Multibody Dynamics

Deformable components in multibody systems are subject to kinematic constraints that represent mechanical joints and specified motion trajectories. These constraints can, in general, be described using a set of nonlinear algebraic equations that depend on the system generalized coordinates and time. When the kinematic constraints are augmented to the differential equations of motion of the system, it is desirable to have a formulation that leads to a minimum number of non-zero coefficients for the unknown accelerations and constraint forces in order to be able to exploit efficient sparse matrix algorithms. This paper describes procedures for the computer implementation of the absolute nodal coordinate formulation' for flexible multibody applications. In the absolute nodal coordinate formulation, no infinitesimal or finite rotations are used as nodal coordinates. The configuration of the finite element is defined using global displacement coordinates and slopes. By using this mixed set of coordinates, beam and plate elements can be treated as isoparametric elements. As a consequence, the dynamic formulation of these widely used elements using the absolute nodal coordinate formulation leads to a constant mass matrix. It is the objective of this study to develop computational procedures that exploit this feature. In one of these procedures, an optimum sparse matrix structure is obtained for the deformable bodies using the QR decomposition. Using the fact that the element mass matrix is constant, a QR decomposition of a modified constant connectivity Jacobian matrix is obtained for the deformable body. A constant velocity transformation is used to obtain an identity generalized inertia matrix associated with the second derivatives of the generalized coordinates, thereby minimizing the number of non-zero entries of the coefficient matrix that appears in the augmented Lagrangian formulation of the equations of motion of the flexible multibody systems. An alternate computational procedure based on Cholesky decomposition is also presented in this paper. This alternate procedure, which has the same computational advantages as the one based on the QR decomposition, leads to a square velocity transformation matrix. The computational procedures proposed in this investigation can be used for the treatment of large deformation problems in flexible multibody systems. They have also the advantages of the algorithms based on the floating frame of reference formulations since they allow for easy addition of general nonlinear constraint and force functions.
PML regulates PER2 nuclear localization and circadian function.

Studies have suggested that the clock regulator PER2 is a tumour suppressor. A cancer network involving PER2 raises the possibility that some tumour suppressors are directly involved in the mammalian clock. Here, we show that the tumour suppressor promyelocytic leukaemia (PML) protein is a circadian clock regulator and can physically interact with PER2. In the suprachiasmatic nucleus (SCN), PML expression and PML–PER2 interaction are under clock control. Loss of PML disrupts and dampens the expression of clock regulators Per2, Per1, Cry1, Bmal1 and Npas2. In the presence of PML and PER2, BMAL1/CLOCK-mediated transcription is enhanced. In Pml−/− SCN and mouse embryo fibroblast cells, the cellular distribution of PER2 is primarily perinuclear/cytoplasmic. PML is acetylated at K487 and its deacetylation by SIRT1 promotes PML control of PER2 nuclear localization. The circadian period of Pml−/− mice displays reduced precision and stability consistent with PML having a role in the mammalian clock mechanism.
Simulated nitrogen deposition affects community structure of arbuscular mycorrhizal fungi in northern hardwood forests

Our previous investigation found elevated nitrogen deposition caused declines in abundance of arbuscular mycorrhizal fungi (AMF) associated with forest trees, but little is known about how nitrogen affects the AMF community composition and structure within forest ecosystems. We hypothesized that N deposition would lead to significant changes in the AMF community structure. We studied the diversity and community structure of AMF in northern hardwood forests after more than 12 years of simulated nitrogen deposition. We performed molecular analyses on maple (Acer spp.) roots targeting the 18S rDNA region using the fungal-specific primers AM1 and NS31. PCR products were cloned and identified using restriction fragment length polymorphism (RFLP) and sequencing. N addition significantly altered the AMF community structure, and Glomus group A dominated the AMF community. Some Glomus operational taxonomic units (OTUs) responded negatively to N inputs, whereas other Glomus OTUs and an Acaulospora OTU responded positively to N inputs. The observed effect on community structure implies that AMF species associated with maples differ in their response to elevated nitrogen. Given that functional diversity exists among AMF species and that N deposition has been shown to select less beneficial fungi in some ecosystems, this change in community structure could have implications for the functioning of this type of ecosystem.
Fundamental asymmetry in interfacial electronic reconstruction between insulating oxides: An ab initio study

We present an ab initio study of the (001) interfaces between two insulating perovskites, the polar ${\text{LaAlO}}_{3}$ and the nonpolar ${\text{SrTiO}}_{3}$. We observe an insulating-to-metallic transition above a critical ${\text{LaAlO}}_{3}$ thickness. We explain that the high conductivity observed at the ${\text{TiO}}_{2}/\text{LaO}$ interface and the lack of similar conductivity at the $\text{SrO}/{\text{AlO}}_{2}$ interface are inherent in the atomic geometry of the system. A large interfacial hopping matrix element between cations causes the formation of a bound electron state at the ${\text{TiO}}_{2}/\text{LaO}$ interface. This mechanism for the formation of interfacial bound states suggests a robust means for tuning conductivities at various oxide heterointerfaces.
Estradiol in the male rat amygdala facilitates mounting but not ejaculation.

Mating activates estrogen sensitive neurons in several regions of male rat brain, including the medial amygdala (MEA). Infusion of the aromatase inhibitor, Fadrozole, into the MEA reduced mating, presumably by inhibiting conversion of testosterone (T) to estradiol (E2). We investigated whether administering E2 locally into the amygdala (AMG) would maintain sexual behavior in male rats given systemic Fadrozole to eliminate E2 elsewhere in the brain. Gonadally intact male rats were divided into two matched groups, based on ejaculatory performance in weekly tests with receptive females. All males received 0.29 mg/kg/day sc Fadrozole and bilateral implants to AMG. E2-in-AMG males (N=6 experimentals) received implants tipped with a cured mixture of E2 in Silastic Medical Adhesive, whereas Vehicle-in-AMG males (N=6 controls) received implants tipped with cured adhesive alone (without E2). In E2-in-AMG males, postoperative mount and intromission frequency did not differ significantly from pretreatment baseline levels, but ejaculation frequency declined significantly (P<.01). Conversely, in Vehicle-in-AMG males, postoperative mounts and intromissions (P<.01) and ejaculations (P<.01) declined significantly. Postoperative mount and intromission frequency of Vehicle-in-AMG males was significantly lower than that of E2-in-AMG males (P<.01), but ejaculation frequency did not differ significantly between groups. This suggests that E2-sensitive AMG neurons are important for sexual arousal but not ejaculatory performance.
Myxomas of the head and neck.

Purpose: Myxomas are rare, locally infiltrative, benign, connective tissue tumors that are found in bone and somatic soft tissues. This article reports our experience with head and neck myxomas and provides a comprehensive literature review. Materials and Methods: Retrospective record review of head and neck myxoma cases seen at 2 tertiary referral centers in Houston, Texas, from 1970 to 1994. Comprehensive literature review and compilation of all myxomas reported in the head and neck. Results: We identified 7 cases of true head and neck myxoma treated in our centers and identified 169 cases reported in the literature. Most often, myxomas originated in bone (mandible or maxilla) and were most commonly found in adults. All tumors except 1 were treated surgically. Recurrence rates were 6% for local or wide excision and 28% for more conservative surgery such as enucleation or curretage. Conclusions: Myxomas of the head and neck should be treated with complete excision of the tumor with clear margins.
On the motion of a second grade fluid due to longitudinal and torsional oscillations of a cylinder : A numerical study

Unsteady problems involving the second grade fluids have received considerable attention in recent years. The present study is an attempt to look at the motion of an oscillating rod in a second grade fluid. Specifically, we solve numerically for the flow of a second grade fluid surrounding a solid cylindrical rod that is suddenly set into longitudinal and torsional motion. The equations are made dimensionless. The results are presented for the shear stresses at the wall, related to the drag force; these are physical quantities of interest, especially in oil-drilling applications.
Optimal Scheduling of Automatic Flushing Devices in Water Distribution System

AbstractMaintaining sufficient chlorine residual in a water distribution system is important for water quality and system integrity. Discharging stagnant water from the pipeline through automatic flushing device (AFD) is a feasible method to maintain water quality. This paper presents a simulation-based optimization method to minimize total AFD discharge volume during a 24-h horizon. EPANET 2.0 is used as a hydraulics and water quality simulator. This is formulated as a single-objective optimization problem. The decision variables are the AFD operation patterns. The methodology has three phases. In the first phase, AFD discharge capacities are calculated to evaluate whether the existing AFDs are able to maintain chlorine residuals in the water network. In the second phase, the decision variables are converted to AFD discharge rates. A reduced gradient algorithm is used to quickly explore and narrow down the solution space. At the end of this phase, decision variables are switched back to the AFD operation...
Activation of CD8+ T cells by allogeneic class II-deficient B-cell lines derived from patients with bare lymphocyte syndrome.

: The major histocompatibility complex (MHC) class II antigens (Ags) are known to carry the major stimulating determinants of the primary mixed lymphocyte reactions (MLR). We investigated the mechanism of generating HLA class I-directed alloreactive T-cells in primary MLR. With the use of class II-deficient EBV-transformed B-lymphoblastoid cell lines (B-LCLs) derived from patients with bare lymphocyte syndrome (BLS), we have demonstrated in the present study that class I disparity alone can trigger primary MLR in the absence of exogenous IL-2. The CD8+ T cells were primary MLR-responsive cells, and the CD4+ T cells seem to play no role in primary MLR when class II alloantigens are not involved in stimulation. Addition of autologous macrophages did not influence the primary MLR response. The primary MLR was completely blocked by anti-class I or anti-CD8 antibodies but not by anti-class II or anti-CD4 antibodies. The MLC-generated CD8+ T cells exhibited cytolytic activity as well as proliferative responses. The proliferative response of the CD8+ T cells was specifically directed against class I antigens, demonstrated by proliferatlire assays; and the helper-independent CD8+. T cells were generated only when the activation of CD4+ T cells did not occur. This observation suggests that functional recruitment of T-cell receptor (TCR) repertoire is under active regulation, and the suppression of CD8+ T-cell helper recruitment appears to be dictated by the CD4+ T-cell subset. Further analysis of the primed T-cell specificities showed that alloreactivity of the CD8+ T cells was mostly accounted for by the HLA-B Ags. The higher alloreactivity against the HLA-B Ags may probably be due to the high frequency of HLA-B-directed T-cell clones, and the high frequency is probably due to their higher sequence variability in HLA-B than in the HLA-A and HLA-C Ags.
The Scientist as Adult

S'inscrivant dans le cadre de la theorie de la theorie developpee par A. Gopnik dans le domaine de la psychologie developpementale, l'A. etudie la question empirique du role des theories dans la vie des scientifiques et dans la vie des enfants. Soulevant le probleme de 1492, c'est-a-dire le probleme du passage des capacites cognitives de l'enfant de 1492 a la science moderne, l'A. montre que l'analogie entre le developpement cognitif et le changement de theorie a peu de consequences pour l'etude de la science en tant qu'activite humaine d'adultes normaux
Functional magnetic stimulation of the respiratory muscles in dogs.

This study assessed the ability of functional magnetic stimulation (FMS) to activate the respiratory muscles in dogs. With the animal supine, FMS of the phrenic nerves using a high-speed magnetic stimulator was performed by placing a round magnetic coil (MC) at the carotid triangle. Following hyperventilation-induced apnea, changes in volume (ΔV) and airway pressure (ΔP) against an occluded airway were determined. FMS of the phrenic nerves produced substantial inspired function (ΔV = 373 ± 20.5 mL and ΔP = −20 ± 2.0 cm H2O). After bilateral phrenectomies, maximal inspired ΔV (219 ± 12.2 mL) and ΔP (−10 ± 1.0 cm H2O) were produced when the MC was placed near the C6–C7 spinous processes, while maximal expired ΔV (−199 ± 22.5 mL) and ΔP (11 ± 2.3 cm H2O) were produced following stimulation near the T9–T10 spinous processes. We conclude: (1) FMS of either the phrenic or upper intercostal nerves results in inspired volume production; (2) FMS of the lower intercostal nerves generates expired volume production; and (3) FMS of the respiratory muscles may be a useful noninvasive tool for artificial ventilation and assisted cough in patients with spinal cord injuries or other neurological disorders. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:1048–1057, 1998.
Determination of Wear Metals in Used Motor Oil by Flame Atomic Absorption Spectroscopy

For decades, railways, trucking companies, and commercial airlines have utilized oil analysis as a diagnostic tool to prevent engine-component failures. This interesting application was developed into an undergraduate lab experiment to introduce chemistry and environmental science majors in their second to fourth year to metal analysis using flame atomic absorption spectroscopy with a non-aqueous sample matrix. Copper, lead, iron, chromium, and silver were quantified by the method of standard additions or by external calibration curves with matrix matching. Students in both environmental analysis and analytical chemistry courses used their data to assess the health of a vehicle’s engine.
Hormones are in the air.

Phytohormones act to control many aspects of plant growth, development, and responses to the environment. Genetic and biochemical studies have identified many of the factors that mediate hormonal control of cell division, expansion, differentiation, and, ultimately, death. However, despite major advances in our understanding of how individual hormones act, we know relatively little about how hormonal signals are integrated into overall responses. For example, the hormones indole-3-acetic acid (IAA), gibberellin (GA), brassinolide, and, in some circumstances, ethylene all promote stem elongation. But what is the role of each hormone, and how do they interact to mediate growth? An abundance of hormone-related mutants, particularly in Arabidopsis , has provided some insights into the mechanisms of cooperative hormone action. Note that the term “cross-talk” is frequently used in this context. However, classically, this term defines phenomena in which there is an unwanted transfer of signals from one circuit, channel, etc., to another (Oxford English Dictionary). These interactions are most certainly not “unwanted.” In a narrower context, crosstalk is generally limited to common elements within a signal transduction scheme. Such a definition clearly ignores a major source of phytohormone interactions: effects of one input signal on accumulation of other input signals. For example, genetic analyses have defined a complex relationship among sugars, abscisic acid (ABA), and ethylene (1, 2) that controls aspects of growth and development. This interaction is regulated at the level of both hormone synthesis and signal transduction. However, the molecular details of this and other interactions are far from understood. Some of the best characterized examples of the complex interactions between phytohormones involve responses to biotic stress. For example, wound responses, such as those induced by chewing insects, integrate jasmonic acid (JA), ethylene, and systemin signaling pathways in a manner yet to be fully established (3, 4). Similarly, …
The formation and molecular structure of acetylcyclopentadienylsodium-tetrahydrofuranate

Abstract Acetylcyclopentadienylsodium has been isolated in crystalline form as a THF adduct from a reaction between cyclopentadienylsodium and methyl acetate in THF solution. The product has been characterized by means of a single-crystal X-ray diffraction study. {[C5H4CMeO]Na·THF}n crystallizes in the monoclinic space group P21/c with unit cell parameters a 6.698(3), b 16.095(4), c 10.661(3) A, β 92.93(3)° and Dc 1.17 g cm−3 for Z = 4. Least-squares refinement led to a final R value of 0.080 based on 661 independent observed reflections. The coordination sphere around each sodium atom consists of the oxygen atoms from two C5H4CMeO ligands, the oxygen atom of the THF molecule, and an ion contact pair between the sodium and the five ring carbon atoms of the C5H4CMeO ligand.
Symplectic structures on locally compact abelian groups and polarizations

LetX be a locally compact abelian group and ω(.,.) a symplectic structure on it. A polarization for (X, ω) is a pair of totally isotropic closed subgroupsG, G* ofX such thatX =G.G* and ω(.,.) defines a dual pairing ofG andG*. In this paper we describe a class of such groups which always admit a polarization and also discuss their structure.
The use of transcranial magnetic stimulation for monitoring descending spinal cord motor function.

This report describes our initial clinical experience using transcranial magnetic stimulation for monitoring spinal cord motor function during surgical procedures. Motor evoked potentials were elic...
Does node stability underlie the verbal transformation effect? A test of node structure theory

Continuous repetition of a word causes listeners to hear the word transform into other utterances, an illusion known as the verbal transformation effect. Node structure theory (MacKay, 1987) provides a useful framework for understanding the illusion, positing that the transformations listeners report are a function of the stability of the node that represents the repeating stimulus. In Experiment 1, the accuracy of this account was investigated, using stimuli that varied from words to phonotactically illegal pseudowords. Experiments 2 and 3 replicated and generalized the findings of Experiment 1, which support a conceptualization of node stability slightly different from that embodied in node structure theory. A new method of measuring lexical influences in the verbal transformation effect is also introduced.
Alternative empirical distributions based on weighted linear combinations of order statistics

A class of empirical distributions is introduced which are based on various weighted linear combinations of order statistics, and which have convergence properties the classical empirical distribution does not, or which stochastically or convexly dominate the classical empirical distribution
Predictability of foot shock differentially affects the phasic blood pressure of SHR, BHR, and WKY rats

Because animals prefer predictable over unpredictable shock, it was hypothesized that rats receiving unpredictable foot shock would show greater phasic blood pressure responses. Furthermore, because some studies utilizing human subjects suggest that blood pressure responses to stress are greater in those with a positive family history of hypertension, the current study examined the phasic blood pressure response to alterations in foot shock predictability in rats with either zero, one, or two hypertensive parents. Predictability was manipulated by altering the percentage of trials during which foot shock was associated with a tone, while at the same time keeping the total number of foot shocks equal in all groups. During the first few trials, the most unpredictable foot shock was associated with higher blood pressure, a trend that was significant for the borderline hypertensive rat (BHR) and marginal for the spontaneously hypertensive rat (SHR). It was also noted that, over the 28 foot-shock trials comprising the stress session, habituation of the blood pressure response was obtained for the most unpredictable shock group. Again, this occurred in those rats with a genetic history of hypertension (SHR and BHR). The results are discussed in relation to studies of stress and blood pressure reactivity in humans with a positive family history of hypertension.
Clinical and Biological Relevance of Genomic Heterogeneity in Chronic Lymphocytic Leukemia

Background Chronic lymphocytic leukemia (CLL) is typically regarded as an indolent B-cell malignancy. However, there is wide variability with regards to need for therapy, time to progressive disease, and treatment response. This clinical variability is due, in part, to biological heterogeneity between individual patients’ leukemias. While much has been learned about this biological variation using genomic approaches, it is unclear whether such efforts have sufficiently evaluated biological and clinical heterogeneity in CLL.
Neural networks for halftoning of color images

This paper illustrates the use of Hopfield neural networks to halftone color images. We define an error function which is the weighted sum of squared errors of the Fourier components of the original and halftoned images. The weights can be chosen to match the human visual system or other input/output transfer functions. The error function is minimized by using a neural network and solving its dynamical equation iteratively. FFTs are used to perform the necessary convolutions so that the computational requirements are reasonable even for large images.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
R-type calcium channels in myenteric neurons of guinea pig small intestine

Currents carried by L-, N-, and P/Q-type calcium channels do not account for the total calcium current in myenteric neurons. This study identified all calcium channels expressed by guinea pig small...
High-performance liquid chromatographic separation of ring-oxidized metabolites of nitro-polycyclic aromatic hydrocarbons☆

Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are widespread genotoxic environmental pollutants, which require metabolic activation to exert their biological activities. Metabolism of nitro-PAHs generates ring-oxidized metabolites including epoxides, phenols, dihydrodiols and tetrahydrotetrols. Separation of the oxidized metabolites and related compounds of a series of isomeric nitro compounds derived from anthracene, benz[a]anthracene, benzo[a]pyrene and benzo[e]pyrene was studied by high-performance liquid chromatography (HPLC) of different types of columns (monomeric and polymeric; reversed-phase and normal-phase). In the reversed-phase HPLC system, the general elution order of these compounds is: parent nitro-PAHs greater than phenolic derivatives greater than epoxides greater than dihydrodiols greater than tetrahydrotetrols. Among the geometric isomers, trans-dihydrodiols with both hydroxyl groups at the quasiaxial positions were eluted earlier than those with the hydroxyl groups at the quasiequatorial positions. Orientation of the nitro substituent has also been found to be an important structural feature for determining the relative retention order. Among the geometric isomers of nitro-PAHs and trans-dihydrodiols, the isomers with their nitro groups perpendicular or nearly perpendicular to the aromatic rings were eluted faster than the analogues with their nitro groups parallel or nearly parallel to the aromatic rings. Normal-phase HPLC gave opposite retention order, but with different separability among some of the compounds. Therefore, combination of both reversed- and normal-phase HPLC provides efficient separation of the ring-oxidized derivatives of nitro-PAHs. Results are also presented to compare the separation efficiency among different types of columns used. The results suggest that the polarity of solutes is the principal factor for determining their HPLC retention time.
Characteristics of partial pressure analyzers

Partial pressure or residual gas analyzers are often invaluable for materials and contamination studies. However, some instrument design features and combination of operating parameters can cause performance features quite different from what many users expect. These unexpected performance characteristics can include pressure-dependent sensitivities, the sensitivity for one gas depending on the pressures of other gases, and time-dependent sensitivities after operation with gases such as oxygen or water. These characteristics can greatly complicate instrument calibration and can cause errors as large as two orders of magnitude. This paper discusses measured performance characteristics for different partial pressure analyzers that illustrate a wide range of performances from the different instruments, as well as several features that seem to be common to most instruments.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Two-dimensional evaporation and substrate heterogeneity effects in submonolayer helium films

A model calculation is used to argue that the low-temperature, low-coverage specific heat of submonolayer4 He films is evidence for the evaporation of a two-dimensional, liquid ground state. The smearing effect of small substrate inhomogeneities is demonstrated, and the effects of the thermal excitation of the liquid state are estimated. Arguments as to why these effects are not present in3 He films are given.
Interstitial thermoradiotherapy for recurrent or persistent tumours

Between 1984 and 1986, 31 sites in 27 patients with biopsy proven tumours were treated with a combination of interstitial microwave hyperthermia (HT) and iridium 192 implants (RT). The 31 sites treated included fifteen (48 per cent) head and neck, six (20 per cent) breast, four (13 per cent) vagina and cervix, and six (20 per cent) others. All patients had prior surgery, RT, or chemotherapy. Of the 31 sites treated, 19 (61 per cent) had complete response (CR) with no recurrence in the volume treated. Additionally, eight patients remained free of tumour from 3 to 24 months. Partial response (PR) was seen in 11 (36 per cent) sites while one (3 per cent) had lesser degree tumour regression. Tumour control rate correlated well with the dose of radiation, p = 0.02, and tumour volume, p = 0.02, but not with thermal dose. Treatment complications of significance occurred in one (3 per cent) site, which developed soft tissue necrosis. This study again has demonstrated the effectiveness of RT-HT combination in treatment of recurrent tumours.