cssi/SciSciGPT-SciSciNet huggingface dataset:
Generalized imitation and the discrimination hypothesis

Abstract Generalized imitation is characterized by the continued imitation of nonreinforced responses even after many sessions of differential reinforcement. Recently it has been suggested that this generalized imitation effect is due to the child's inability to discriminate reinforced from nonreinforced occasions. The results of the three experiments described in the present article indicate that the “discrimination explanation” may be only partially correct. Although children imitated a nonreinforced response when no reinforced alternative was available, they reliably imitated the reinforced response when it was presented in a choice procedure. Similarly, S s immediately stopped imitating nonreinforced responses when simply instructed to stop. It was suggested that the generalized imitation effect is largely a function of instructional and other social variables operating within typical generalized imitation procedures.
Effect of chronic hyperserotoninemia on platelet monoamine oxidase activity and serotonin uptake

Abstract Rabbits are unique in having markedly elevated concentrations of platelet serotonin as well as very high activity of type A monoamine oxidase (MAO). Because type A MAO preferentially metabolizes serotonin, it is possible that serotonin induces the formation of type A MAO. We evaluated the platelet MAO activity of patients with chronic hyperserotoninemia from the carcinoid syndrome as well as platelet MAO in patients with non-serotonin-producing carcinoid tumors. Both groups had normal platelet MAO activity. The in vitro platelet equilibrium accumulation of serotonin in patients with the carcinoid syndrome is much lower than that of normal subjects. The platelet serotonin accumulation of rabbits does not differ from the platelet serotonin uptake of normal subjects. The platelet serotonin accumulation of patients with cancer (without the carcinoid syndrome) is also markedly decreased and comparable to that of patients with the carcinoid syndrome. Further studies will be needed to elucidate the nature of this defect in platelet serotonin uptake in patients with non-serotonin-producing malignancies.
Effects of cat exposure and cat odors on subsequent amphetamine-induced stereotypy.

Abstract The effect of exposure to a cat, as a predatory stressor, was examined in male and female rats during subsequent tests or amphetamine-induced stereotypy in which cat odors were present or absent. Rats in Group C/O were given a 15-min exposure session to a male cat while they were protected in a wire cage. They were then given an IP injection of d-amphetamine (1 mg/kg) and tested 30 min later for stereotypy in the presence of cat odors (soiled cat litter). Rats in Group NC/O were given a no-cat-exposure control session, and amphetamine tested with cat odors. Groups C/NO and NC/NO were both tested without cat odors (fresh litter), with the former group having previously exposed to a cat. During the 90-min test sessions, female rats showed significantly more stereotypy than males. More importantly, the male subjects in group C/O exhibited significantly more stereotypy than the males in the other groups, and group NC/NO males showed the least amount of stereotypy. These findings clearly indicate that amphetamine reactivity is influenced by prior exposure to a predator, the presence of predatory odors during testing, and the subject's sex.
A multiple sector search method for extracting viewing strategy from fundus images obtained through a scanning laser ophthalmoscope

The scanning laser ophthalmoscope (SLO) is an instrument of great value for observing viewing behaviour and characteristics of fixation in macula disorders; it also may have potential in assessing visual rehabilitation in affected individuals. It is important to understand the viewing strategies used by individuals with a central scotoma and eccentric fixation and to determine whether these strategies have changed as a result of any eccentric viewing training. We describe a method based on searching for multiple sectors in relative correspondence in consecutive SLO fundus images. In this method, successive fixation positions, and consequently viewing strategy, during the reading of isolated words and text passages can be extracted from SLO images. We found the maximum cumulative error in determining fixation position over 1000 consecutive frames to be 5 pixels (approximately 15 min arc) using fundus images from an individual with a macular lesion and clearly visible retinal features. The reconstruction of...
Design and implementation of a campus computer ethics policy

As the set of people using computers becomes larger and less cohesive, it is becoming important to educate users about their ethical responsibilities. Design of an effective campus computer ethics policy requires awareness of numerous cultural, technical and legal issues. Especially important are the cultural splits between power users and utilitarian users, and between “old world” and “new world” philosophies of computer ethics. Discusses those issues and presents the University of Georgia’s ethics policy as a model to aid those developing similar policies at other institutions.
Within-modal and cross-modal reliabilities of two laterality tests.

Abstract Sixteen right handers were given four tests of a dichotic listening recall task (concrete words) and a visual half-field recall task (letters). There was a significant right ear and right visual half-field superiority for the four test sessions, with improvement in recall scores over sessions. Pearson correlations for each ear on the four dichotic tests ranged from .74 to .90. Correlations on the visual half-field scores, however, were significant only after the first session. Analysis of stability in lateral preferences across modalities revealed stable and reliable performance, particularly in the last two testings, where 81.3% of the subjects had a right-sided asymmetry. Cross-modal correlations, however, were not significant. Implications regarding predictions of speech laterality are discussed in the light of these findings.
Thermal strain recovery of anelastic monodomain liquid crystalline networks: Mechanically induced strains ratios

A series of smectic liquid crystalline network polymer was subjected to a large uniaxial stress at temperatures far below the clearing temperature. Their dimensional recovery is anelastic showing substantial retained strain. This process produced a temporally stable monodomain state. Upon heating this monodomain from room temperature, recovery of the original film dimensions occurs. The strain recovery (length) curves show a pronounced curvature as the temperature approaches the smectic-isotropic temperature. It is proposed that nanosegregation of netpoints in the smectic structure is responsible for the anelasticity and that the temperature dependence of the shape recovery is consistent with a balance between enthalpic and entropic forces with temperature. An interesting mechanically induced strains ratio (MISR) was observed on heating these prestressed films. Loss of the monodomain structure near the isotropization temperature is postulated to rationalize the shape of the MISR curves.
Factors predicting readmission of older general medicine patients.

Objectives:1) Identify demographic, clinical, social support, functional, and psychological factors about which data are available within 24 hours of hospital admission associated with emergent unscheduled readmission for a group of older general medicine patients; 2) develop a model to predict emergent readmission. Design:Interview- and cbart-based study of emergent admissions that occurred within 60 days of discharge. Setting:General medicine wards of the Memphis Veterans Affairs Medical Center, an 862-bed university-affiliated tertiary care facility. Patients/participants:General medicine patients ≥ 65 years old (n=173). Inclusion criteria were willingness to participate, written consent (patient or family member), and patient interview within 36 hours of admission. Measurements and main results:The dependent variable was emergent readmission within 60 days of discharge from the hospital. Independent variables included demographic (age, race, income, education), social support (marital status, living arrangements), psychological (cognition, depression), activities of daily living functioning, and clinical (diagnoses, type and source of admission, length of stay, numbers of hospitalizations and days of hospitalizations in the past year, illness severity) parameters. Readmitted patients were emergently admitted and more severely ill, had more diagnoses of chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF), less ischemic heart disease, and more hospitalizations and hospital days in the past year (all p<0.05). Logistic regression identified diagnostic group (COPD or CHF), emergent admission, and admission severity of illness as predictive of readmission. The likelihood of being readmitted was 5.4. Accuracy of the three-variable model was 76%, predicted value positive, 73%, and predictive value negative, 77%. Conclusions:Chronically ill patients who are severely ill at index admission and who have had several hospitalizations in the past year tend to be readmitted. Using this model, high-risk patients may be prospectively targeted to reduce readmissions.
Tools for distributed collaborative environments: a research agenda

Argues that future computing environments will be collaboration-oriented, globally distributed and computation/information-rich. These environments will be accessed via multiple interface devices. As we move from a desktop-centric computing model to a network-centric model, new approaches in the way software and data are handled will need to be developed. In this article, we outline the requirements for enabling the technological infrastructure, describe some first steps that we have taken toward building this infrastructure, and sketch directions for future development.
Salt and fluid homeostasis in protein energy malnutrition.

Protein energy malnutrition (PEM) during early childhood is very often associated with edema. In fact, the well-known Wellcome classification of PEM from 1970 is based upon the reduction in weight in relation to age and whether edema is present or absent. In this presentation our knowledge of the disturbance in fluid and electrolyte homeostasis as seen in PEM will be reviewed. The implication of this disturbance for the treatment of acute dehydration in children with PEM will also be discussed. A balanced fluid and salt homeostasis is the prerequisite of physiological compartment volumes and efficient nutritional supply. Under physiological conditions water requirement is related to the requirement of salt at the same time as water balance is regulated by antidiuretic hormone.
From Serving in the Military to Serving Loved Ones: Unique Experiences of Older Veteran Caregivers

Objective We examined whether older caregiving veterans differ from noncaregiving veterans in terms of health and psychosocial factors and how these factors and caregiving aspects (i.e., hours, relationship type) relate to caregiving strain and reward. We also evaluated two hypotheses: (1) combat exposure provides protection from emotional caregiving strain, and (2) grandparenting is particularly rewarding. Methods We used a cross-sectional web survey of a nationally representative sample of older veterans in the United States. Data were drawn from the National Health and Resilience in Veterans Study, and participants were 2,025 U.S. veterans aged 60 or older (mean: 71.0; SD: 7.1; range: 60–96). Participants completed measures of caregiving status, sociodemographic characteristics, combat exposure, physical and mental health, cognitive status, and psychosocial characteristics. Caregivers reported caregiving hours, caregiving type, emotional and physical strain, and reward. Results A total of 20.4% of U.S. older veterans are caregivers. As predicted, among the veteran caregivers, (1) combat exposure was associated with less emotional caregiving strain (odds ratio [OR]: 0.57), and (2) grandparenting was associated with increased perception of caregiving reward (OR: 5.28). Resilience was negatively associated with physical strain, whereas depressive symptoms were associated with greater emotional strain; gratitude, happiness, and social support were additionally associated with greater reward. Caregivers were more likely to be married and highly educated than noncaregivers but did not differ with respect to health or psychosocial characteristics. Conclusion One in five older U.S. veterans is a caregiver. Older veterans' combat exposure may decrease the emotional demands of caregiving, and grandparenting is perceived as particularly rewarding. Results suggest that older veterans are an important caregiving resource that deserves tailored resources.
Inelastic electron tunneling spectroscopic study of the silane coupling agents II. γ-aminopropyltriethoxysilane adsorbed from vapor on aluminum oxide surface and effects of high humidity

Abstract Effects of high humidity on γ-aminopropyltriethoxysilane adsorbed from vapor on a plasma grown Al 2 O 3 surface were studied by measuring inelastic electron tunneling spectra of the sample exposed to 75% relative humidity for various lengths of time. The majority of the initially adsorbed silane is desorbed by the exposure to high humidity and the remaining silane undergoes hydrolysis. Ethanol produced by hydrolysis is probably oxidized to acetaldehyde on the Al 2 O 3 surface. Interaction between the vapor deposited silane and the surface OH groups is inferred from the frequency shifts of the stretching mode of the surface OH groups. Reorientation of the adsorbed silane molecules in the tunneling barrier caused by the initial exposure to high humidity is observed.
Epstein-Barr viral load as a marker of lymphoma in AIDS patients

Epstein-Barr virus (EBV) is implicated in the pathogenesis of acquired immunodeficiency syndrome (AIDS) lymphoma, and viral DNA is present within the malignant cells in about half of affected patients. We examined the extent to which EBV viral load is elevated in the plasma of AIDS lymphoma patients compared to AIDS patients with opportunistic infections. Sixty-one AIDS patients were studied including 35 with lymphoma (24 non-Hodgkin, six Hodgkin, and five brain lymphoma) and 26 with various opportunistic infections. In situ hybridization revealed EBV encoded RNA (EBER) expression in the malignant cells of 17/28 AIDS lymphomas (61%). In 232 serial plasma samples from 35 lymphoma patients and in 128 samples from AIDS controls, EBV viral load was assayed by quantitative-polymerase chain reaction (Q-PCR) using a TaqMan probe targeting the BamH1W sequence. EBV was detected in plasma from all 17 EBER-positive AIDS lymphoma patients, with viral loads ranging from 34 to 1,500,000 copies per ml (median 3,210). Viral load usually fell rapidly upon initiation of lymphoma therapy and remained undetectable except in two patients with persistent tumor. In 11 AIDS patients, whose lymphoma lacked EBER expression, and in 26 control patients without lymphoma, levels of EBV in plasma were usually low or undetectable (range 0-1,995 and 0-2,409, median 0 and 0, respectively). There was no association between EBV viral load and human immunodeficiency virus (HIV) load or CD4 count. In conclusion, EBV viral load shows promise as a tool to assist in diagnosis and management of EBV-related lymphoma patients.
Antioxidant and prooxidant roles for β-carotene, α-tocopherol and ascorbic acid in human lung cells

Abstract Experiments were conducted to determine the antioxidant and prooxidant effects of β-carotene, α-tocopherol and ascorbic acid on human lung cells at different oxygen (O 2 ) tensions. Free radical initiator, 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH), was used to induce the cellular damage associated with lipid peroxidation, protein oxidation and DNA breaks. Under hypoxic conditions (0 torr O 2 tension) all compounds produced a concentration-dependent antioxidant effect. Mixtures of the three compounds exhibited greater protective affects than any individual compound. At 143 torr O 2 tension, all compounds exhibited concentration-dependent protective effects against AAPH-induced cellular lipid, protein and DNA damage. At 722 torr O 2 tension, cells exhibited a consistent increase in lipid peroxidation (isoprostane formation), protein oxidation (carbonyl formation) and DNA damage (p53 protein accumulation). β-Carotene (1.5 μ m ) produced a prooxidant effect by promoting 12% isoprostane formation. Protein oxidation and DNA damage at 722 torr O 2 tension was not increased by β-carotene; however, the antioxidant effect of β-carotene was attenuated. The antioxidant effects of α-tocopherol, ascorbic acid, and mixtures of the three antioxidant compounds also were reduced by the high O 2 conditions. These results partially substantiate the hypothesis that the antioxidant and prooxidant effects of β-carotene are dependent on O 2 tension and concentration of β-carotene. Such findings may partially explain why selected populations, such as smokers, respond adversely when supplemented with β-carotene.
Characterization of herpes simplex virus clinical isolate Y3369 as a glycoprotein G variant and its bearing on virus typing

Background Herpes simplex viruses exist as two major serotypes, type 1 (HSV-1) and type 2 (HSV-2). Determination of type, either HSV-1 or HSV-2, is important in accurate diagnosis and clinical control of transmission. Several tests are available for typing HSV, including a monoclonal antibody specific for glycoprotein G and several PCR assays.
Reduction of RF power for magnetization transfer with optimized application of RF pulses in k-space

More efficient use of RF power for RF-intensive applications such as magnetization transfer (MT) is necessary at high field strength (3.0 T or greater) to keep the specific absorption rate (SAR) within regulatory limits. It has been demonstrated that RF power deposition can be reduced with minimal impact on image quality by preferential application of MT pulses to the central phase-encoding views. This work extends that approach to both phase-encoding directions in a 3D acquisition (i.e., phase and slice) and further improves it by modulating the flip angle of the MT pulse according to the phase-encoded view's distance to the center of k-space. This technique is implemented for 3D time-of-flight (TOF) MR angiography (MRA) and the parameters for MT pulse are optimized based on phantom studies at 3.0 T. MT applied with this method at 3.0 T is shown to improve the blood vessel detectability in high-resolution intracranial 3D TOF MRA exams of 11 patients.
The Notch targets Esr1 and Esr10 are differentially regulated in Xenopus neural precursors.

The HES family of bHLH repressors plays a key role in regulating the differentiation of neural precursors in the vertebrate embryo. Members of the HES gene family are expressed in neural precursors as targets of the Notch signaling pathway, but how this occurs in the context of neurogenesis is not known. Here, we address this issue by identifying enhancers driving Notch-dependent gene expression of two Hes5 -like genes expressed in Xenopus called Esr1 and Esr10 . Using frog transgenesis, we identify enhancer elements driving expression of Esr1 and Esr10 in neural precursors or in response to ectopic expression of the proneural protein, Xngnr1. Using deletion and mutation analysis, we define motifs required for enhancer activity of both genes, namely Notch-responsive elements and, in the case of Esr10, E-box motifs. We find that Esr1 and Esr10 are differentially regulated both in terms of Notch input and its interaction with heterologous factors. These studies reveal inputs required for proneural expression of genes encoding bHLH repressors in the developing vertebrate nervous system.
Rats' preference for the more effortful of two responses as a function of prior experience.

Three groups of rats were each given 14 days of lever-press training under different conditions. One group was allowed to press only on a FR3 schedule, a second only on a CRF schedule, and a third received alternate-day training on CRF and FR3 schedules. Following training, 4 days of choice tests were given during which animals were allowed to choose between the two schedules of responding. Rats trained on the FR3 schedule both preferred to respond and obtained more rewards on that schedule, while rats in the other 2 groups preferred the CRF schedules. Results indicated that the degree of rats' preference for effortful responding is a function of the conditions of prior training.
Banding in entangled polymer fluids under oscillatory shearing

We report a flow phenomenon in entangled polymer solutions that has never been described in the literature. A large-amplitude oscillatory shear was imposed on the polymer sample at a frequency higher than the overall chain relaxation rate. The resulting chain orientation led to a new environment in which the initially well-entangled chains managed to disentangle inhomogeneously in space. A layer lacking chain entanglement developed to take the load of the imposed strain. As a result of this nonlinearity, the rest of the sample avoided significant deformation and its chain entanglement remained intact.
α-Substituted Phosphonate Analogues of Lysophosphatidic Acid (LPA) Selectively Inhibit Production and Action of LPA

Isoform-selective agonists and antagonists of the lysophosphatidic acid (LPA) G-protein-coupled receptors (GPCRs) have important potential applications in cell biology and therapy. LPA GPCRs regulate cancer cell proliferation, invasion, angiogenesis, and biochemical resistance to chemotherapy- and radiotherapy-induced apoptosis. LPA and its analogues are also feedback inhibitors of the enzyme lysophospholipase D (lysoPLD, also known as autotaxin), a central regulator of invasion and metastasis. For cancer therapy, the ideal therapeutic profile would be a metabolically stabilized pan-LPA receptor antagonist that also inhibits lysoPLD. Herein we describe the synthesis of a series of novel alpha-substituted methylene phosphonate analogues of LPA. Each of these analogues contains a hydrolysis-resistant phosphonate mimic of the labile monophosphate of natural LPA. The pharmacological properties of these phosphono-LPA analogues were characterized in terms of LPA receptor subtype-specific agonist and antagonist activity using Ca(2+) mobilization assays in RH7777 and CHO cells expressing the individual LPA GPCRs. In particular, the methylene phosphonate LPA analogue is a selective LPA(2) agonist, whereas the corresponding alpha-hydroxymethylene phosphonate is a selective LPA(3) agonist. Most importantly, the alpha-bromomethylene and alpha-chloromethylene phosphonates show pan-LPA receptor subtype antagonist activity. The alpha-bromomethylene phosphonates are the first reported antagonists for the LPA(4) GPCR. Each of the alpha-substituted methylene phosphonates inhibits lysoPLD, with the unsubstituted methylene phosphonate showing the most potent inhibition. Finally, unlike many LPA analogues, none of these compounds activate the intracellular LPA receptor PPARgamma.
Cumulative lead dose and cognitive function in adults: a review of studies that measured both blood lead and bone lead.

ObjectiveWe review empirical evidence for the relations of recent and cumulative lead dose with cognitive function in adults.Data SourcesA systematic search of electronic databases resulted in 21 e...
Side effects of three antihistaminic drugs.

Abstract 1.1. A comparison of Benadryl, Pyribenzamine, and Hydryllin was made on the basis of their effect in therapeutic dosage on mental ability, reaction time, two point discrimination distance, pulse rate, blood pressure, and respiratory rate. 2.2. Mental ability, reaction time, and minimum distance of two point discrimination were appreciably altered by these drugs in over one-half the subjects tested. 3.3. Pyribenzamine caused a greater number of individuals to show a decrease in efficiency than did Benadryl, but the latter occasionally caused decreases of considerably greater magnitude. 4.4. Hydryllin caused an increased efficiency in a majority of the subjects but adversely affected a few. 5.5. It is suggested that patients begun on therapy with these antihistaminic drugs be at first kept under strict observation.
Strengthening the Foundation for Information Literacy in an Academic Library

The relationship between the library and the information literacy movement is acknowledged, and a further delineation of responsibility at the academic reference service level is examined. Reference librarians' perspective enables them to serve as "information advisors," fostering students' development of information storage and retrieval, this role becomes increasingly important. The need for students to emerge as independent learners is crucial at this stage in their lives. Information literacy abilities are discussed as a by-product of general reference functions. Reference librarians are urged to encourage the growth of these abilities by stimulating students' understanding of critical thinking.
A study on carbon dioxide cycle architectures for light-commercial refrigeration systems

Abstract In this study four refrigeration cycles were experimentally investigated in an attempt to enhance the thermodynamic performance of CO 2 -based transcritical refrigeration systems under high ambient temperatures. The cycle architectures studied were: i) capillary tube, ii) expansion valve, iii) dual-stage expansion and iv) flash gas chamber. It was found that the coefficient of performance values of the first three cycle designs were almost the same in the temperature range studied. Additionally, performance improvements of around 20% and 28% in the cooling capacity and coefficient of performance were found when an internal heat exchanger was added to the baseline cycle. Performance gains of 10% and 15% in the cooling capacity and coefficient of performance were also found with the flash gas chamber cycle design, without compromising the discharge line temperature.
A computational study on power-law rheology of soft glassy materials with application to cell mechanics

Response of the cytoskeleton to mechanical stimulus, which involves coordinated assembly and disassembly of cytoskeletal polymers and their coupling to motor proteins, has been shown to be governed by a ubiquitous mechanical behavior called power-law rheology. Various experimental techniques in cell mechanics have yielded similar qualitative observations and quantitative behavior indicating that the power-law rheology is an intrinsic feature of the cell structure. In this study, a biomechanical model of the cell in microbead twisting experiments is developed which incorporates the material law associated with power-law rheology using the finite element method. Such a biomechanical model can help elucidating the mechanics of cytoskeletal responses and relate the microrheology of the cytoskeleton to its overall behavior under mechanical stimulus. This biomechanical model is employed to explore the role of material constants associated with power-law rheology on the overall response of a cell in magnetic twisting cytometry. Furthermore, the computational approach is employed to mimic the experimental observations of [B. Fabry, G.N. Maksym, J.P. Butler, M. Glogauer, D. Navajas, J.J. Fredberg, Scaling the microrheology of living cells, Phys. Rev. Lett. 87 (2001) 148102; B. Fabry, G.N. Maksym, J.P. Butler, M. Glogauer, D. Navajas, N.A. Taback, E.J. Millet, J.J. Fredberg, Time scale and other invariants of integrative mechanical behavior in living cell, Phys. Rev. E, 68(4) (2003) 041914] on living cells.
Association of XK and Kell Blood Group Proteins

A disulfide bond links Kell and XK red cell membrane proteins. Kell, a type II membrane glycoprotein, carries over 20 blood group antigens, and XK, which spans the membrane 10 times, is lacking in rare individuals with the McLeod syndrome. Kell is classified in the neprilysin family of zinc endopeptidases, and XK has structural features that suggest it is a transport protein. Kell has 15 extracellular cysteines, and XK has one in its fifth extracellular loop. Five of the extracellular cysteine residues in Kell are not conserved in the other members of the neprilysin family, and based on the hypothesis that one of the nonconserved cysteines is linked to XK, cysteines 72 and 319 were mutated to serine. The single extracellular cysteine 347 of XK was also mutated. Co-expression of combinations of wild-type and mutant proteins in transfected COS-1 cells showed that Kell C72S did not form a Kell-XK complex with wild-type XK, while wild-type Kell and Kell C319S did. XK C347S was also unable to form a complex with wild-type Kell, indicating that Kell cysteine 72 is linked to XK cysteine 347. Kell C72S was transported to the cell surface, indicating that linkage to XK is not required. In addition, chemical cross-linking of red cell membranes with dithiobispropionimidate indicated that glyceraldehyde-3-phosphate dehydrogenase is a near neighbor of Kell.
Benzoic acid inhibition of the α, β, and γ isozymes of Agaricus bisporus tyrosinase

Inhibition of the catecholase and cresolase reactions of the alpha, beta, and gamma isozymes of Agaricus bisporus tyrosinase by benzoic acid was investigated at 25.0 and 8.0 degrees C at pH 5.60 in air-saturated solutions. Benzoic acid is a simple competitive inhibitor of the cresolase reaction of all three isozymes. In the catecholase reaction, however, benzoic acid is a partial uncompetitive inhibitor of the alpha and beta isozymes and a simple competitive inhibitor of gamma-tyrosinase. Equilibrium dialysis experiments, conducted under identical conditions to the kinetic studies, indicate that benzoic acid can bind to the alpha and gamma isozymes in the absence of organic substrate. The dissociation constants obtained by equilibrium dialysis are in good agreement with the kinetic Ki values determined from inhibition studies. Maximum binding of benzoic acid to alpha and gamma tyrosinase, however, is significantly less than one mole per mole of active sites. A scheme in which benzoic acid binds to the oxy-form of tyrosinase is proposed to account for the kinetic and equilibrium results.
The effect of proof-testing on the Weibull distribution

The statistical aspects of proof-testing as they relate to the Weibull cumulative distribution function (cdf) are described. Properties of the truncated Weibull cdf which arise from proof testing are presented. The need for accurate parameter estimation techniques is discussed, and the maximum likelihood (ML) method is developed for this application. Two examples are given which demonstrate the applicability and usefulness of the truncated Weibull cdf. One example, developed from proof-testing single filaments, illustrates the results for ungrouped data. The other, taken from an application of optical image analysis of creep cavities in stain less steel, is an example of the analysis for grouped data.
Anomalous Mitral Arcade A Type of Congenital Mitral Insufficiency

Described in three infants is an anomaly of the mitral valvular mechanism which has the following characteristic: connection of the left ventricular papillary muscles to the anterior mitral leaflet, either directly or through the interposition of unusually short chordae. The condition has been named "anomalous mitral arcade." The anatomic aberration appears to cause incompetence of the mitral valve.
Structural integrity of an ablating rocket subjected to axial acceleration

One of the important design conditions for solid propellant rocket motors is that of inertia loading due to long term storage at 1 g, or acceleration in short time to high g. This paper investigates the structural integrity for inertia loading of a long, bonded, thick-walled cylinder, and includes the parametric considerations of rocket diameter 26, web fraction X, inertia g-level n, and reduced burnout time t//ar, as well as employing typical propellant properties and allowing for various burning rates of the eroding boundary. Finite end effect correction factors can be included from references already in the literature. By assuming a maximum shear strain failure criterion, a design envelope is obtained of pgnob vs t//ar, which expresses the interaction among the various parameters.
Building Natural Science Communities.

By giving concerted attention to each of the junctures at which students were being lost to the study of science and mathematics, a community of K–16 educators realizes greater success and persistence for its students.
Synthesis and Characterization of Bis(2,2‘:6‘,2‘ ‘-terpyridine)ruthenium(II)-Connected Diblock Polymers via RAFT Polymerization

We report the synthesis and uses of a novel terpyridine-functionalized chain transfer agent (CTA) that produces well-controlled macromolecular architectures with terpyridine functionalities at one chain end via reversible addition−fragmentation chain transfer (RAFT) polymerization. The terpyridine-terminated macromolecules with well-defined structures were further used for preparation of supramolecular diblock metallomacromolecules by bis(2,2‘:6‘,2‘ ‘-terpyridine)ruthenium(II) complex connectivity. The successful connectivity between two macromolecular blocks via the metallocomplex was confirmed by UV−vis, size exclusion chromatography (SEC), and differential scanning calorimetry (DSC) as well as atomic force microscopy (AFM) techniques.
The Sunward Tail of Comet Arend-Roland

COMET AREND-ROLAND (1956h) displayed in late April a remarkable spike-like tail directed roughly towards the Sun. This tail developed from a diffuse fan-shape on April 22 to a long and narrow spike attaining its maximum reported length of 15° on April 25.9 U.T., according to the observation of Fogelquist1. By April 29 the sunward tail had essentially disappeared. Van Biesbroeck2 reported it as being a “slender jet 4° long” on April 24.1 and estimated a length of some 13° on April 25. No observations of length on April 26 are yet available to me, so it appears that the maximum extension of the sunward tail took place some time during April 25–26.
Chemical reduction of ligated nitrosyl in Fe2(NO)4(μ-SR)2

Abstract Reduction of Fe 2 (NO) 4 (μ-SR) 2 ( 1 ,R  Me or Et) with two equivalents of sodium dispersion, KH, LiBEt 3 H or Li- or KB( s -Bu) 3 H in THF affords [Fe 2 (NO) 4 (μ-SR) 2 ] 2− ; treatment of product solutions with an excess of R′I (R′  Me or Et) yields 1 , Fe 2 (NO) 4 (μ-I) 2 and Fe 2 (NO) 4 (μ-SR)(μ-NHR′) or Fe 2 (NO) 4 (μ-SR)(μ-NHEt) (when the reductant is LiBEt 3 H).
Diode laser spectra of the C-O stretch band of gaseous methyl alcohol

Abstract High-resolution diode laser spectra of the P and R branches of the C-O fundamental stretch band of gaseous methyl alcohol are presented. Spectral line assignments are made over the range 1027 through 1068 cm −1 . The relationship to other types of spectroscopy is discussed.
Turkey Leucocytozoon Infection: 1. A Rapid Diagnostic Staining Method

Abstract A staining method is described for the rapid detection and identification, even at low densities, of turkey leucocytozoon parasites in peripheral blood films. The method is based on the high staining contrast of leucocytozoon parasites in films stained with brilliant cresyl blue. This contrast allows the use of low magnification and permits rapid scanning of large areas.
Contribution of fat metabolism to 'glucoprivic' feeding produced by fourth ventricular 5-thio-D-glucose.

Abstract We examined whether manipulations of fat metabolism influence the feeding response to periheral or central administration of 5-thio- d -glucose (5-TG), a potent inhibitor of glucose utilization. The increase in food intake produced by peritoneal (50 mg/kg) or fourth ventricular (50, 100, 150 μg) 5-TG was potentiated by administration of the fatty acid oxidation inhibitor, methyl palmoxirate (10 mg/kg, p.o.). In addition, rats maintained on a high-fat diet ate less in response to fourth ventricular 5-TG (150 μg) than did rats maintained on an equicaloric low-fat diet. These results suggest that the feeding response to ‘glucoprivation’ is determined by the interaction of glucose and fat oxidation.
1998 equivalence of sensory responses to single and mixed volatile organic compounds at equimolar concentrations.

Exposure to low levels of chemicals indoors is often to a mixture of volatile organic compounds (VOCs). It is of interest to determine if the symptomatic and sensory responses can be attributed to ...
A generalized corresponding states theory for the surface tension of liquids and liquid mixtures

The principle of corresponding states can be generalized to include substances that depart from conformality by introducing state dependent shape factors. This principle has been applied to the surface tension of pure liquids and their mixtures. Extensive comparisons with experimental data yield an average deviation of 3 percent for pure nonpolar liquids and 4 percent for mixtures.
EXACT AND APPROXIMATE DISTRIBUTIONS FOR THE LINEAR COMBINATION OF INVERTED DIRICHLET COMPONENTS

It is well known that X + Y has the F distribution when X and Y follow the inverted Dirichlet distribution. In this paper, we derive the exact distribution of the general form αX + βY (involving the Gauss hypergeometric function)and the corresponding moment properties. We also propose approximations and discuss evidence of their robustness based on the powerful Kolmogorov-Smirnov test. The work is motivated by real-life examples in quality and reliability engineering.
Catalysis with ceria nanocrystals: Bio-oil model compound ketonization

Abstract The problems associated with the high content of organic acids present in bio-oil can potentially be alleviated through the use of the ketonization reaction. While there have been previous reports that ketonization reactions are sensitive to the surface morphology of the respective catalyst, these studies have largely been performed in idealized conditions. Here, shape selective ceria nanocatalysts were synthesized and examined in both condensed and vapor phase ketonization reactions with the model bio-oil compound, acetic acid. It was found that in lower temperature (503 K) condensed-phase conditions the morphology of the catalyst was of less importance due to crystal disruption from metal carboxylate formation. However, the bulk structure was maintained to a greater extent in the higher temperature (623 K) vapor phase conditions. This work demonstrated that surface morphology of the ceria catalyst did not play a significant role in the ketonization reaction.
Home visitation programs: Critical Issues and Future Directions

Abstract As support for intervening early in the lives of vulnerable children has risen in the United States in recent years, so has interest in home-visitation programs. Home visitation is increasingly recognized for its potential to foster early child development and competent parenting, as well as to reduce risk for child abuse and neglect and other poor outcomes for vulnerable families. This paper provides a discussion of several aspects of home-visitation programs that warrant further development and evaluation, including the powerful role of context in determining program outcomes, as well as the impact of other factors, including service dosage, levels of family engagement, and characteristics of home visitors. The importance of more accurately understanding and measuring risk and engaging family members beyond the mother–child dyad is also discussed. Recommendations are made for making improvements in all of these areas, in order to strengthen home-visitation programs and produce better outcomes for the children and families they serve. Aspects of Nurse Family Partnership and Early Head Start, two widely replicated and rigorously evaluated programs, are highlighted to demonstrate how the issues discussed here are likely to affect service delivery and program outcomes. The multiple challenges inherent in replicating and evaluating home-visitation programs that are truly responsive to the needs of a wide array of families with young children are examined. This discussion concludes with a call to expand and improve methods for evaluating these programs, and to view home visitation as a component of a comprehensive system of child and family supports, rather than as a stand-alone model of intervention.
Exact solutions and the adiabatic heuristic for quantum Hall states

Abstract An operator formalism is developed for an exactly soluble model of fractional statistics, and used to show that a heuristic principle suggested earlier is rigorously valid in one particular case. For a class of model hamiltonians, Laughlin's Jastrow-type wave functions are obtained explicity from a filled Landau level by smooth extrapolation in quantum statistics. The gap is shown not to close, which allows us to infer the incompressibility of the final states. The analysis is further extended to paired Hall states at even-denominator fillings, which arise adiabatically from an exact but unnormalizable model of superconductivity. Finally, we generalize the model to the torus geometry, and show that theorems restricting the possibilities of quantum statistics on closed surfaces are circumvented in the presence of a magnetic field.
Phase-slip dissipation in crystalline La1.8Sr0.2NiO4-δ

Abstract Using a contact-less microwave technique, we have identified a phase transition in small crystals of La 1.8 Sr 0.2 NiO 4-δ . This transition is coincident with a weak diamagnetic response, most likely to a superconducting state. The transition region is very broad, with a width ∼ K. The temperature-dependent shape of the transition is accurately described by a model which describes a network of a small superconducting regions connected by weak links.
Some thoughts on stochastic adaptive control

Some recent concepts and results on asymptotically optimal control rules in several classical stochastic adaptive control problems are reviewed and discussed. In particular, ways to resolve the apparent dilemma between the need for information and the objective of efficient control in these problems are presented. Asymptotic lower bounds on the minimal amount of information needed and a general heuristic principle are also given.
Local Melting during Electromigration in Cu Conductor Lines

We have observed abrupt, reversible resistance changes during electromigration (EM) testing of damascene Cu conductor lines. The tests were conducted at temperatures of 300°C or 350°C and with current densities from 0.6 × 106 A/cm2 to 1.6 × 106 A/cm2. In most cases, an incubation period with negligible resistance increase was followed by a period of continuous, gradual resistance increase, attributed to formation and growth of voids in the conductor line. If the direction of current was reversed, the resistances of the Cu lines decreased, due to the refilling of voids by the back flowing atoms. With further EM, the resistance curves showed spikelike features, with a sudden resistance increase followed by a resistance decrease, often to values close to those before the start of EM. In other cases, no resistance decrease occurred, and the line failed. We present resistance data, microstructural observations, and thermal calculations that suggest that the resistance decrease results from sudden, local Joule heating and melting of conductor line segments, and from voids being partially filled by the back-flowing liquid Cu, which then solidifies. In some cases, line failure results from liquid Cu erupting through the top surface passivation layer, rather than flowing back to the voids.
Somatostatin- and Substance P-Like Immunoreactivity in Rat Neostriatal Cultures

In the normal adult neostriatum, somatostatin immunoreactive interneurons constitute a few percent of the total neuronal population whereas substance P immunoreactive neurons, which project to the substantia nigra, constitute nearly half of the total. Primary monolayer neostriatal cultures derived from E17 rat brains displayed both somatostatin-like and substance P-like immunoreactivity (SOM-IR and SP-IR). However, the proportions of SOM-IR and SP-IR neurons in vitro were significantly different from those in vivo. At 4 days in vitro (DIV), SOM-IR neurons comprised 19% of all neurons and this percentage increased to 30% at 25 DIV. In contrast, SP-IR neurons were less common than expected at 4 DIV (20%) and declined in percentage to 13% at 27 DIV. These results suggest that survival in target-deprived neostriatal cultures is favored for SOM-IR interneurons.
Multitargeted Effects of Statin-Enhanced Thrombolytic Therapy for Stroke With Recombinant Human Tissue-Type Plasminogen Activator in the Rat

Background— Microvascular dysfunction posttreatment of stroke with recombinant human tissue-type plasminogen activator (rht-PA) constrains the therapeutic window to 3 hours. Statins (3-hydroxy-3-me...
Relative performance of preemption-safe locking and non-blocking synchronization on multiprogrammed shared memory multiprocessors

Most multiprocessors are multiprogrammed to achieve acceptable response time. Unfortunately inopportune preemption may significantly degrade the performance of synchronized parallel applications. To address this problem, researchers have developed two principal strategies for concurrent, atomic update of shared data structures: (1) preemption safe locking and (2) non blocking (lock free) algorithms. Preemption safe locking requires kernel support. Non blocking algorithms generally require a universal atomic primitive, and are widely regarded as inefficient. We present a comparison of the two alternative strategies, focusing on four simple but important concurrent data structures-stacks, FIFO queues, priority queues and counters-in microbenchmarks and real applications on a 12 processor SGI Challenge multiprocessor. Our results indicate that data structure specific non blocking algorithms, which exist for stacks, FIFO queues and counters, can work extremely well: not only do they outperform preemption safe lock based algorithms on multiprogrammed machines, they also out perform ordinary locks on dedicated machines. At the same time, since general purpose nonblocking techniques do not yet appear to be practical, preemption safe locks remain the preferred alternative for complex data structures: they outperform conventional locks by significant margins on multiprogrammed systems.
The potential of the cell processor for scientific computing

The slowing pace of commodity microprocessor performance improvements combined with ever-increasing chip power demands has become of utmost concern to computational scientists. As a result, the high performance computing community is examining alternative architectures that address the limitations of modern cache-based designs. In this work, we examine the potential of using the forthcoming STI Cell processor as a building block for future high-end computing systems. Our work contains several novel contributions. First, we introduce a performance model for Cell and apply it to several key scientific computing kernels: dense matrix multiply, sparse matrix vector multiply, stencil computations, and 1D/2D FFTs. The difficulty of programming Cell, which requires assembly level intrinsics for the best performance, makes this model useful as an initial step in algorithm design and evaluation. Next, we validate the accuracy of our model by comparing results against published hardware results, as well as our own implementations on the Cell full system simulator. Additionally, we compare Cell performance to benchmarks run on leading superscalar (AMD Opteron), VLIW (Intel Itanium2), and vector (Cray X1E) architectures. Our work also explores several different mappings of the kernels and demonstrates a simple and effective programming model for Cell's unique architecture. Finally, we propose modest microarchitectural modifications that could significantly increase the efficiency of double-precision calculations. Overall results demonstrate the tremendous potential of the Cell architecture for scientific computations in terms of both raw performance and power efficiency.