cssi/SciSciGPT-SciSciNet huggingface dataset:
Intellectual activities and influences of Belver C. Griffith: A citation perspective

Based on an analysis of the 377 documents that cited Griffith's publications in the ISI citation databases, it has been found that Griffith made pioneer and significant contributions with his collaborators to the fields of bibliometrics and scholarly communication among scientists. His research work has also greatly influenced people from all over the world conducting research in psychology, bibliometric information science, and social studies of science in the past several decades.
Formation and stability of vincristine-tubulin complex in kidney cytosols. Role of GTP and GTP hydrolysis

Abstract Vincristine-tubulin complex formed in the 100,000 g fraction of mouse kidney dissociated rapidly at 37° in the absence of guanosine-5′-triphosphate (GTP). In the presence of 2 mM GTP, there was a substantial (2.8-fold) increase in complex stability; NaF (100 mM) but not β-glycerophosphate (1 mM) also reduced the rate of dissociation. Further, complex was stabilized by other ribonucleuside-5′-triphosphates (but not their respective 5′-monophosphates), and a nonhydrolyzable of GTP. Stability of the VCR-tubulin complex formed in cytosol from kidney and separated from unbound VCR and GTP by gel filtration was influenced by the concentration of GTP. These results appear not to be a consequence of denaturation of tubulin during incubation, as VCR binding activity remained constant under experimental conditions both in the presence and after the removal of GTP. Further, the rate of formation of the VCR-tubulin complex in kidney was also influenced by the concentration of GTP and was increased by the addition of NaF. In the absence of added GTP, virtually no complex was isolated. ATP, CTP, or ITP has little effect on complex formation, suggesting that the effect may be GTP specific. These data suggest that the destabilizing activity in cytosols prepared from the mouse kidney, and the failure to form a stable VCR-tubulin complex in kidney, are in part the consequence of rapid hydrolysis of GTP by a pyrophosphohydrolase. Direct measurement of the hydrolysis of GTP showed that the activity in kidney (9.26 nmol/min/mg protein) was 9.3-fold greater than in tumor extracts.
CRSL: A language for classificatory problem solving and uncertainty handling

In this article, we present a programming language for expressing classificatory problem solvers. CSRL (Conceptual Structures Representation Language) provides structures for representing classification trees, for navigating within those trees, and for encoding uncertainly judgments about the presence of hypotheses. We discuss the motivations, theory, and assumptions that underlie CRSL. Also, some expert systems constructed with CSRL are briefly described.
The Preparation, Characterization, and X-Ray Structural Analysis of Dichlorobis[1-methyl-3-(2-propyl)-2(3H)-imidazolethione]mercury(II)

A new compound of mercury(II) chloride complexed to 1-methyl-3-(2-propyl) -2(3H)-imidazolethione (mipit) has been prepared and characterized via standard methods and X-ray crystallography. The structural significance of this study is that it shows one of the few monomeric examples of a mercury(II) chloride thione complex reported to date. The compound crystallizes in space group P21/c with a = 17.143(6) A, b = 17.047(6) A, c = 14.759(5) A, β = 105.899(5)°, V = 4148(2) A3, Z = 8. The coordination sphere is distorted tetrahedral with Hg–S bonds and Hg–Cl bond distances falling within the normally expected ranges. Bond angles ranged from 108.11(4)° to 115.51(4)° with the widest angle being observed for the S–Hg–S linkage. Ligand bond distances and angles including the C=S distance are within the normally expected values observed for this compound.
Being uninformed on informed consent: a pilot survey of medical education faculty

Background This paper describes a pilot survey of faculty involved in medical education. The questionnaire focuses on their understanding of IRB policies at their institution, specifically in relation to the use of student assessment and curriculum evaluation information for scholarship.
Drugs and Security in the Caribbean: Sovereignty Under Siege

Drugs and Security in the Caribbean: Sovereignty Under Siege. Ivelaw L. Griffith. University Park, PA: Pennsylvania State University Press, 1997. 320 pp. (Cloth US$35, Paper US$16.95)
Immunophenotyping Combined with Laser Capture Microdissection (Immuno-LCM)

The collection of homogeneous or pure cell populations for molecular analyses has been a difficult challenge for many years. Many different approaches have been tried unsuccessfully to obtain pure populations of pituitarycells. Recent developments in laser capture microdissection have facilitated the process of acquiring homogeneous cell populations. Some investigators have combined LCM with immunophenotyping before performance of the LCM procedure. With this combined approach, immunophenotypically homogeneous cell population can be readily collected for molecular analyses. We will review the general approaches to immuno-LCM and show how these methods have been applied recently for the analysis of folliculostellate cells in the pituitary gland.
The connectionist framework for gene regulation

I show that gene regulation networks are qualitatively consistent and therefore sufficiently similar to linearly seperable connectionist networks to warrant that the connectionist framework be applied to gene regulation. On this view, natural selection designs gene regulation networks to overcome the difficulty of development. I offer some general lessons about their evolvability that can be learned by examining the generic features of connectionist networks.
Deformational dynamics and NMR relaxation of supercoiled DNAs.

The conformation and internal dynamics of supercoiled pUC 8 DNA (2717 bp) are examined by dynamic light scattering, and the magnitude and uniformity of its torsional rigidity are determined using time-resolved fluorescence polarization anisotropy of intercalated ethidium dye. Neither measurement gives any indication of an appreciably reduced bending or twisting rigidity, or anomalously rapid internal motions. For 31P, in supercoiled pUC 8, we measure T2 = (2.0 ± 0.5) × 10−3 s. This lies within the range of present theoretical estimates obtained using normal rigidities. The proton linewidths observed for pUC 8 and pBR322 (4363 bp) DNAs are within a factor of 2–3 of those similarly estimated assuming ordinary rigidities. According to Bendel, Laub and James [(1982) J. Am. Chem. Soc.104, 6748–6754], supercoiled pIns36 DNA (7200 bp) exhibits an astonishingly long T2 = 1.17 s for 31P, a slowest rotational relaxation time, τ = 5 × 10−9 s, and an enormously reduced bending rigidity. Serious questions raised by these findings are examined here. The 5 × 10−9 s slowest rotational relaxation time is shown to be physically inadmissible. The nmr relaxation theory developed previously by Allison, Shibata, Wilcoxon, and Schurr [(1982) Biopolymers21, 729–762], is modified to incorporate new results for deformable filaments, which directly introduce the highly nonexponential tumbling correlation function for reorientation of the local helix axis. Essential requirements for a complete calculation of R2, including estimation of the tumbling correlation function and evaluation of the still unknown DIP/CSA cross-term, are described in detail. Slow coil-deformation modes analogous to the Rouse-Zimm modes of linear DNAs are shown to make an important, if not dominant, contribution to the R2 relaxation rate. Geometrical parameters in the theory are chosen to provide good agreement with literature data for 600-bp linear DNA. Using this theory and an informed guess for the tumbling correlation function, we find that the 31P-nmr relaxation data of Bendel et al., if correct, necessarily impose on their DNA one or more extreme properties, such as enormously reduced bending or twisting rigidities. In contrast, the same theory yields reasonable agreement with the T2 reported here for 31P in supercoiled pUC 8 DNA when its rigidities are assumed to be quite ordinary.
A note on relative motion in the general three-body problem

It is shown that the equations of the general three-body problem take on a very symmetric form when one considers only their relative positions, rather than position vectors relative to some given coordinate system. From these equations one quickly surmises some well known classical properties of the three-body problem, such as the first integrals and the equilateral triangle solutions. Some new Lagrangians with relative coordinates are also obtained. Numerical integration of the new equations of motion is about 10% faster than with barycentric or heliocentric coordinates.
Generation and nonlinear self-trapping of optical propelling beams

We generate optical beams with rotating intensity blades by employing the moire technique. We show that the number of the blades and the speed and direction of rotation can be controlled at ease with a spatial light modulator, while no mechanical movement or phase-sensitive interference is involved. By applying a noninstantaneous self-focusing nonlinearity, we demonstrate both theoretically and experimentally self-trapping of such optical propelling beams.
Somatostatin inhibition of epinephrine-induced glucagon secretion.

Synthetic linear somatostatin at a concentration of 100 ng/ml has been shown to markedly inhibit glucagon release from the isolated perfused rat pancreas with perfusate glucose concentration at 80 mg/100 ml. In addition, stimulation of glucagon release by epinephrine (50 ng/ml) was blocked by somatostatin (100 ng/ml). (Endocrinology 95: 1744,1974)
Lower limits of organic reactions. III

Spectrofluorometry was used to confirm completeness of the reaction of carbonyls in 5.0 · 10−4 to 5.0 · 10−7 molar solutions. This procedure of estimation is 1000 times more sensitive than spectrophotometric methods.
The Use of Tandem Mass Spectrometry for the Structure Determination of Adducts Formed Between DNA and Dibenzo[a,l]pyrene

Abstract Tandem mass spectrometry was used in the structure determinations of adducts formed between nucleosides and the potent carcinogen dibenzo[a,l]pyrene. Adducts expected to arise from both the one-electron oxidation mechanism and by the diol epoxide mechanism were studied. Structural isomers of the adducts can be distinguished by the fragment ions observed in their respective collisionally activated decomposition (CAD) spectra.
Iron Salts Perturb Biofilm Formation and Disrupt Existing Biofilms of Pseudomonas aeruginosa

Bacterial biofilms are thought to aid in the survivability of a variety of intractable infections in humans. Specifically, biofilm production in Pseudomonas aeruginosa has been shown to play a significant role in chronic infection of cystic fibrosis (CF) patients. Unfortunately, no clinically effective inhibitors of biofilm formation are available. A rapid screen of 4509 compounds for nonantibiotic biofilm inhibitors in Pseudomonas aeruginosa PA14 was executed in 384-well plates. Among those compounds, ferric ammonium citrate inhibited biofilm formation in a dose-dependent manner; other iron salts functioned similarly. In addition to biofilm inhibition in static culture, pregrown biofilms could be disrupted and cleared by switching to iron-rich media in flow-chamber experiments. Furthermore, P. aeruginosa strains taken from the sputum of 20 CF patients showed a similar response to elevated iron levels. Previous expression-profiling analyses demonstrated that high levels of iron repress the expression of genes whose products are essential for scavenging iron and that expression of these genes is critical for virulence. Our results, combined with existing transcriptional-profiling data, now indicate that elevated iron concentrations repress the expression of certain genes essential for biofilm production in P. aeruginosa.
Protein kinase C-linked inactivation of the interleukin-1 receptor in a human transformed B-cell line.

Abstract The effect of tumor-promoting phorbol ester treatment on the binding of interleukin-1β (IL-1β) to specific cell surface receptors was investigated. A 1 h exposure of Raji human B lymphoma cells with the protein kinase C-activating phorbol ester, phorbol dibutyrate (PDBu), reduced IL-1β binding by up to 90% of control cells. This effect was dose-dependent and was not observed with 4-α-phorbol, an inactive tumor promoter. Analysis of 125I-labeled IL-1β binding to intact cells revealed that PDBu caused a 91% decrease in high-affinity cell-surface receptor number without an effect on receptor affinity. The phorbol ester response was rapid (30 min), observed both at 4 and 37°C, and was preceded by the rapid translocation ( t ⋘ 6 min ) of protein kinase C (PKC) from the cytosol to the cell membrane. The PDBu-induced decrease in IL-1β receptor number was inhibited by prior incubation of cells for 30 min with the PKC inhibitor 1-(5-Isoquinoline sulfonyl)-2-methylpiperazine (H7). The decrease in receptor binding was not due to enhanced IL-1β receptor internalization or shedding into the extracellular medium, since a similar effect was observed with solubilized IL-1β receptor. The most likely explanation for the phorbol ester effect appears to be cell surface inactivation of IL-1 receptors. These data suggest that modulation of PKC activity could play a role in the regulation of the IL-1β receptor.
Incidence and Risk Factors for Multiple Antibiotic-Resistant Pseudomonas aeruginosa in Cystic Fibrosis

Background Infection with multiple antibiotic-resistant Pseudomonas aeruginosa (MARPA) in individuals with cystic fibrosis (CF) has caused much concern among caregivers, yet little is known about the risks associated with acquiring resistance. The main objective of the study was to estimate the incidence and identify risk factors for the acquisition of MARPA among individuals with CF. Methods Five-year cohort study of individuals followed in the Cystic Fibrosis Foundation Registry from 1998 through 2002. Results Demographics, anthropometrics, spirometry, respiratory culture results, comorbidities, antibiotic usage, and hospitalizations were collected. Of the 4,293 patients with P aeruginosa infection during the study period, MARPA developed in 341. The overall incidence of MARPA was 1.8%/yr. Independent risk factors for MARPA included CF-related diabetes mellitus (hazard ratio [HR], 1.64; 95% confidence interval [CI], 1.11 to 2.43), long-term inhaled tobramycin usage (HR, 2.08; 95% CI, 1.56 to 2.77), and care at a CF center with a baseline MARPA prevalence in the top quartile (HR, 2.00; 95% CI, 1.31 to 3.04). Frequent courses of IV antibiotics and repeated hospitalizations were also found to independently increase the risk for MARPA. Conclusions Infection with MARPA is common among patients with CF. Diabetes, long-term inhaled tobramycin usage, and frequent acute pulmonary exacerbations requiring hospitalization or IV antibiotics increase the risk for MARPA. Receiving CF care at a center with a high prevalence of resistant Pseudomonas also increases the risk for MARPA in patients with CF. Further study is needed to investigate the mechanisms of acquiring resistant strains and the clinical impact of MARPA on CF outcomes.
Dialectical Contradictions Experienced When Placing a Spouse With Dementia in a Residential Care Facility

Placing a spouse with dementia in a care facility can be a devastating decision, and the placement process can be disruptive and difficult for all involved. This case study explores dialectical contradictions experienced during the placement decision-making process, on the day of placement, and in the weeks following placement. Ways in which findings could be applied to support spouses at this difficult time are also discussed.
AlGaN-based ultraviolet light-emitting diodes grown on AlN epilayers

AlGaN-based deep-ultraviolet light-emitting diode (LED) structures, which radiate light at 305 and 290nm, have been grown on sapphire substrates using an AlN epilayer template. The fabricated devices have a circular geometry to enhance current spreading and light extraction. Circular UV LEDs of different sizes have been characterized. It was found that smaller disk LEDs had higher saturation optical power densities but lower optical powers than the larger devices. This trade-off between power and power density is a result of a compromise between electrical and thermal resistance, as well as the current crowding effect (which is due to the low electrical conductivity of high aluminum composition n- and p‐AlGaN layers). Disk UV LEDs should thus have a moderate size to best utilize both total optical power and power density. For 0.85mm×0.85mm interdigitated LEDs, a saturation optical power of 2.9mW (1.8mW) at 305nm (290nm) was also obtained under dc operation.
Wear of some cemented tungsten carbide tools in machining oak

Abstract An examination of several cemented tungsten carbide tools that were used in cutting oak containing a high moisture content (green) is described in this paper. It is shown that wear occurs through the process of continuous tool nose rounding. It is proposed that the wear mechanism involves the preferential removal of the binder (cobalt) through chemical reaction with extractives present in the oak (tannins), followed by mechanical loss of tungsten carbide grains when the strength of the remaining bond between them and the binder is insufficient to resist the action of the shear forces generated by motion of the chip and the freshly machined workpiece surface over the faces of the tool. It is also proposed that there is an absence of adhesive and abrasive wear but that some wear could occur through tool edge chipping.
Distinct and long-lived activity states of single enzyme molecules.

Individual enzyme molecules have been observed to possess discrete and different turnover rates due to the presence of long-lived activity states. These stable activity states are thought to result from different molecular conformations or post-translational modifications. The distributions in kinetic activity observed in previous studies were obtained from small numbers of single enzyme molecules. Due to this limitation, it has not been possible to fully characterize the different kinetic and equilibrium binding parameters of single enzyme molecules. In this paper, we analyze hundreds of single β-galactosidase molecules simultaneously; using a high-density array of 50 000 fL-reaction chambers, we confirm the presence of long-lived kinetic states within a population of enzyme molecules. Our analysis has isolated the source of kinetic variability to kcat. The results explain the kinetic variability within enzyme molecule populations and offer a deeper understanding of the unique properties of single enzyme...
STRENGTH, ABRASIVE WEAR, AND DURABILITY PROPERTIES OF DENTAL COMPOSITES CONTAINING A FLUORINATED DIMETHACRYLATE REACTIVE DILUENT

The effects of the fluorinated triethyleneglycol dimethacrylate (F-TEGDMA) on the mechanical properties of composites made with this monomer, under both dry and aged conditions, was investigated. Photo-polymerizable formulations of 50/50, 30/70 and 10/90 mol:mol% F-TEGDMA/BisEMA (F5E5, F3E7 and F1E9), and 50/50 mol/mol% TEGDMA/BisEMA (T5E5) and TEGDMA/BisGMA (T5G5) were mixed with 76 wt% of silanated BaSiO2 filler to form the experimental composite formulations. The experimental T5E5 and T5G5 formulations and a commercial composite HXR (Herculite XR, Kerr), having a similar formulation to the T5G5 group, served as the controls. The compressive strength (CS), diametral tensile strength (DTS), flexural strength (FS) and abrasive wear rate (WR) were determined and compared. Scanning electron microscopy (SEM) techniques were used to evaluate the fracture surfaces. ANOVA and Tukey-Kramer tests were used to determine between group differences. The study shows that replacing TEGDMA with F-TEGDMA does not signifi...
The Aalpha6 locus: its relation to mating-type regulation of sexual development in Schizophyllum commune.

We have isolated and examined the Aα6 mating-type locus of Schizophyllum commune as a first step toward resolving a functional difference between this locus and the Aα loci previously studied. Our analyses show Aα6 to be remarkably similar to the Aα loci of known structure. The locus is composed of two, divergently transcribed genes similar in size to known Z and Y genes of the Aα loci. We have termed the two genes, Z6 and Y6, on the basis of their demonstrated mating activities and encoded protein motifs. The Z6 gene encodes a homeodomain-related sequence, two acidic regions and a predicted coiled-coil motif. The Y6 gene encodes a homeodomain, predicted coiled-coil motif, two regions with homology to the Aβ locus gene V6, a basic region encoding a putative nuclear localization sequence and a serine-rich region. The Z6 and Y6 proteins share these features with the other known Z and Y proteins, respectively. One of the two amino acid sequences with homology to the AβV6 protein has not previously been reported.
Unresolved Issues in the Forensic Use of DNA Profiling

The enormous amount of genetic diversity in humans allows for a powerful form of individual identification. This “DNA profiling”; is based on the fact that sites within the human genome have variable numbers of tandem repeats (VNTRs) and has been hailed in forensic sciences as the greatest discovery since fingerprinting. The techniques involved are virtually the same as those used in all molecular biology laboratories. A major difference however is that in forensic science DNA samples can be less than ideal in both quality and quantity. Furthermore, in basic molecular biology the origin of the sample is known while in forensic testing it is not. Thus, the challenge is to reconcile a “match”; between a crime scene DNA sample and one from a suspect(s). Presently, a debate exists regarding the use of the unmodified product rule versus a more conservative ceiling principle approach to calculate the probability of a coincidentally matching DNA profiles. The latter was endorsed in a recently published report by...
Measures of hostility as predictors of facial affect during social interaction: Evidence for construct validity

We assessed the construct validity of several self-report measures and an interview-based measure of hostility (Interpersonal Hostility Assessment Technique [IHAT]) by evaluating their associations with a behavioral indicator of hostile emotions (facial expressions during social interaction). Participants in the study were 123 volunteers (44% males and 56% females) who were recruited from local community organizations. Self-report measures (Cook-Medley Hostility Scale, Rotter Interpersonal Trust Scale, Buss-Durkee Hostility Inventory, and Spielberger Anger Expression Scale) were represented by factor scores reflecting Overt Hostility, Covert Hostility, and Hostile Beliefs. A canonical correlation analysis identified significant associations between a set of facial affect scores reflecting animosity and various measures of hostility. Specifically, increases in anger and disgust expressions and decreases in happy facial expressions were associated with high IHAT scores and high scores on self-report measures of Hostile Beliefs and Covert Hostility. Women were more expressive than men, especially concerning positive affect, and women had lower scores on self-report measures of Hostile Beliefs and Overt Hostility. IHAT scores were uncorrelated with any of the self-report factors which suggests the two assessment techniques are tapping different aspects of the hostility construct.
Resident education does not correlate with the degree of emergency department crowding

Study objectives: We study the effect of emergency department (ED) crowding on medical student and emergency medicine resident perception of educational interaction with attending physicians. Our hypothesis is that the perceived quality of clinical teaching is decreased when crowding conditions exist in the ED. Methods: An emergency medicine residency program (postgraduate years [PGYs] 1 to 3) with an annual census of 92,000 patient visits and 64 hours of attending physician coverage at the primary hospital served as the study site. A 1-page survey was completed by study participants at the close of their shift and was used to quantify perception of the quality of teaching received, as well as crowding in the ED. The surveys used a 10-cm visual analog scale evaluating whether the attending physician was effective at didactic/bedside teaching, available/accessible, efficient in patient management, approachable, and professional and provided adequate supervision. Participants were asked to rate the value of the learning experience, whether the ED seemed busy, and whether there was adequate time to spend with patients. The data were analyzed using regression analysis. Results: A total of 184 surveys were completed during a 3-month period, representing a 42% return rate. The degree of actual and perceived ED crowding did not correlate with effectiveness of didactic and bedside teaching, attending availability, efficiency in patient management, approachability, professionalism, and adequacy of supervision. Correlation coefficients ranged from r =−0.06 to 0.19. Furthermore, study participants' perceptions of ED crowding and actual daily ED census did not correlate ( r =0.06). Conclusion: Medical students' and emergency medicine residents' perception of teaching does not correlate with the degree of actual or perceived ED crowding. Study participants could not consistently identify when ED crowding existed. Educational interactions with attending physicians appear to be minimally affected by fluctuations in patient care demands.
Fundamental and special: The dilemma of psychiatric-mental health nursing

This article explores the tension between defining psychiatric-mental health nursing as fundamental to the discipline yet also special, an historic dilemma that continues to influence efforts to establish a secure place for the specialty. Analysis focuses on the formative work of three pioneers in this field, using primary and secondary documents in the archives of the Center for The Study of The History of Nursing. The findings of this research indicate that early reliance on interpersonal theory provided an uncertain basis for differentiating psychiatric-mental health nursing from other areas of nursing practice.
Calcium Release and Subsequent Development Induced by Modification of Sulfhydryl Groups in Porcine Oocytes

The mechanism of Ca2+ release induced by modification of sulfhydryl groups and the subsequent activation of porcine oocytes were investigated. Thimerosal, a sulfhydryl-oxidizing compound, induced Ca2+ oscillation in matured oocytes. In thimerosal-preincubated oocytes, the amount of Ca2+ released after microinjection of inositol 1,4,5-trisphosphate (InsP3) or ryanodine increased strikingly, indicating that thimerosal potentiated both InsP3- and ryanodine-sensitive Ca2+ release pathways. Thimerosal also enhanced the sensitivity of oocytes to microinjected Ca2+ so that in pretreated oocytes a Ca2+ injection triggered a larger transient. Heparin at concentrations that normally block the InsP3-induced Ca2+ release were without effect; higher doses significantly increased the time leading up to the first spike. The thimerosal-induced Ca2+ release could not be blocked by procaine, and it did not require the formation of InsP3 since preinjection with neomycin did not prevent the oscillation. Immunocytochemistry revealed that thimerosal treatment destroyed the meiotic spindle, preventing further development, an effect that could be reversed by dithiothreitol. The combined thimerosal/dithiothreitol treatment triggered second polar body extrusion in 50% of the oocytes, and as a result of this activation scheme approximately 15% of the in vitro- and approximately 60% of the in vivo-matured oocytes developed to blastocyst during a 7-day culture in vitro.
Japanese and American Identities: Values and Their Transmission in the Family

In this paper, we are studying social identities within a cross-national framework as they are reflected in values regarding social institutions. We compare value items to infer similarities and differences between Japan and the US, but more importantly we analyze value configurations, using factor analysis, as an expression of underlying cultural expectations. We also argue that the way values are transmitted further defines the distinctive cultural basis of social identities. Using a unique data set, The Generations Survey, we propose to contribute theoretically and methodologically to understanding the role of culture in postmodern societies. Our research, based on identical national surveys collected in 1995, provides a systematic way to compare values in two countries. The research builds on and specifies existing ethnographic case studies and in-depth interviews around a variety of themes that shape social identities such as the link between family and work expectations, the role of ethical values in business, the importance of national identification, and the meaning of community involvement. The paper concludes by suggesting that despite homogenizing trends and surface similarities, cultural distinctiveness persists in the ways values cluster and is transmitted in the family, shaping the social identities of Japanese and US respondents.
Thermal requirements for development and simulation of the seasonal phenology of Encarsia perniciosi (Hymenoptera : aphelinidae), a parasitoid of the San Jose scale (Homoptera : diaspididae) in North Carolina orchards

Developmental rates from egg to adult for a uniparental race of Encarsia perniciosi (Tower), an endoparasitoid of the San Jose scale Quadraspidiotus perniciosus (Comstock), were determined using first instar hosts at 20°C, and using second instar hosts at 15, 20, 25, 28, 29.5, and 31°C under a regime of 16:8 (L:D) photoperiod. Parasitoids developed in male and female San Jose scale. Development rate was highest in male second instars, intermediate in females second instars, and lowest in first instar nymphs. Temperature versus development rate data were used to estimate parameters for both linear and nonlinear models of parasitoid development in male, female, and male and female hosts combined. Simulated adult flight peaks, based on linear and nonlinear models, were compared with peaks of adult parasitoid activity in three orchards during 1986 and 1987, and adult activity was measured using San Jose scale pheromone-baited and colored sticky traps. Modeled peaks agreed well with the spring flight peaks (F2 and F3), but were generally earlier than peaks occurring during the summer generations (F4 and F5) and later than those of autumn generations (F6 and F7). The linear model for parasitoids developing in male and female hosts combined simulated 8 of 13 parasitoid peaks within ±7 d, whereas the nonlinear model was accurate for 7 of 13 peaks. Up to seven parasitoid flight periods per season were detected.
Is α‐lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity

The chemical reduction and oxidation (redox) properties of α-lipoic acid (LA) suggest that it may have potent antioxidant potential. A significant number of studies now show that LA and its reduced form, dihydrolipoic acid (DHLA), directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of insults where oxidative stress is part of the underlying etiology. However, owing to its limited and transient accumulation in tissues following oral intake, the efficacy of nonprotein-bound LA to function as a physiological antioxidant has been questioned. Herein, we review the evidence that the micronutrient functions of LA may be more as an effector of important cellular stress response pathways that ultimately influence endogenous cellular antioxidant levels and reduce proinflammatory mechanisms. This would promote a sustained improvement in cellular resistance to pathologies where oxidative stress is involved, which would not be forthcoming if LA solely acted as a transient ROS scavenger. © 2008 IUBMB IUBMB Life, 60(6): 362–367, 2008
New experimental developments for in situ XAFS studies of chemical reactions under hydrothermal conditions

Abstract New experimental developments for in situ X-ray absorption fine structure spectroscopy (XAFS) studies of hydrothermal systems are described. Improvements in materials of construction and the design of spectroscopic cells have allowed application of XAFS as a powerful method to derive the molecular structures of reacting species. Two different spectroscopic cells are described that are suitable for in situ XAFS studies of aqueous solutions under hydrothermal conditions. One cell consists of a titanium alloy body with a corrosion-resistant platinum–iridium insert and diamond windows for X-ray transmission. Using this cell, XAFS spectra were acquired on aqueous tungstate solutions up to 400°C. The results demonstrate how XAFS can be used to study the speciation of isopolytungstates and their equilibria at high temperatures. Results from model calculations using the FEFF ab initio code are used to explain the observed spectral changes with changes in pH and temperature. The second XAFS cell consists of a simple fused-silica capillary having a 180 μm inner diameter. High-quality spectra of a 0.2 molal nickel bromide solution were collected in these small capillaries demonstrating the feasibility of the approach to the study of a wide range of geochemical systems. Further, the XAFS spectra show that the nickel bromide solution irreversibly reacts with the fused-silica capillary at 425°C. Based upon these observations, a potential use of the fused-silica capillary is suggested for in situ studies of silicate formation, or, in general, for studies of chemical interactions of hydrothermal brine solutions with quartz.
Argiotoxin-636 blocks effects of N-methyl-D-aspartate on lateral line of Xenopus laevis at concentrations which do not alter spontaneous or evoked neural activity.

Abstract Activity of primary afferent neurons in acousticolateralis organs can be modulated by excitatory amino acids (EAA) and their antagonists, and EAA are among the better candidates for the transmitter(s) between hair cells and afferent neurons. Argiotoxin-636 (ATX) is a spider venom toxin that is a selective antagonist of the N -methyl- D -aspartate (NMDA) subtype of excitatory amino acid receptors in vertebrates. In the present study, the effects of NMDA alone and in combination with ATX on resting firing rate (spontaneous activity) and mechanically stimulated activity of lateral line afferent neurons of post-metamorphic Xenopus laevis were compared. Perfusion of NMDA (100 or 200 μM) typically produced a biphasic effect on spontaneous activity consisting of a transient increase followed by a decrease in firing rate. Mechanical stimulation applied after the initial response to NMDA produced an increase in firing activity that was not significantly different from the increase in firing activity evoked in the absence of NMDA. ATX at 1–2 μM did not alter either spontaneous or evoked activity, but blocked in a reversible manner both the excitatory and inhibitory actions of NMDA on spontaneous activity. These results suggest the presence of an NMDA receptor in the lateral line but do not support the hypothesis that the generation of action potentials by the afferent transmitter is solely dependent on activation of postsynaptic NMDA receptor-ion channels.
The influence of Mo2C morphology and distribution on the fatigue crack initiation and propagation behavior of Fe-C-Mo dual-phase steels

Dual-phase microstructures consisting of ferrite with carbides (Mo2C) surrounding equiaxed martensite packets have been developed in two alloys, Fe-O. 2C-4Mo and Fe-O. 2C-2Mo. These alloys were chosen because of the presence of two distinct carbide morphologies: (1) a needle-shaped interphase carbide structure, and (2) a fibrous carbide structure. Isothermal transformations were used to control the carbide morphology and distribution in the ferritic regions of the dual-phase microstructures. In the present research the effects of changes in carbide structure on low cycle fatigue (LCF) and fatigue crack growth (FCG) behavior were studied. Crack initiation was observed at prior austenite grain boundaries in the fibrous microstructure, and along intrusion/extrusion defects in the interphase needle microstructures for LCF tests. TEM studies revealed a carbide free region at prior austenite grain boundaries where initiation occurs for the fibrous case. The cyclic stress/strain response of the ferritic portions of the microstructure is determined by the ability of the carbides to homogenize the strain found there. This affects the stress/strain distribution in the composite ferrite-martensite microstructure by changing the hardness ratio of the two phases and subsequently alters the fatigue crack growth behavior and the macroscopic cyclic stress/strain response. Strain localization was also found to affect the roughness induced closure found for fatigue crack growth tests for low R tests (R = 0.1).
Analysis of an autonomous clutter background characterization method for hyperspectral imagery

ABSTRACT Hyperspectral ground to ground viewing perspective presents major challenges for autonomous window based detection. One of these challenges has to do with object scales uncertainty that occur when using a window-based detection approach. In a previous paper, we introduced a fully autonomous parallel approach to address the scale uncertainty problem. The proposed approach featured a compact test statis tic for anomaly detection, whic h is based on a principle of indirect comparison; a random sampling stage, which does no t require secondary informati on (range or size) about the targets; a parallel process to mitigate the inclusion by chance of target samples into clutter background classes during random sampling; and a fusion of results at the end. In this paper, we demonstrate the effectiveness and robustness of this approach on different scenarios using hyperspectral imagery, where for most of these scenarios, the parameter settings were fixed. We also investigated the performance of this suite over different times of the day, where the spectral signatures of materials varied with relation to diurnal changes during the course of the day. Both visible to near infrared and longwave imagery are used in this study. KEYWORDS: Parallel anomaly detection, hyperspect ral imagery, and random sampling
Application of Ground-Penetrating-Radar Methods in Hydrogeologie Studies

A ground-penetrating-radar system was used to study selected stratified-drift deposits in Connecticut. Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. Traverse locations on land included a well field in the town of Mansfield, a sand and gravel pit and a farm overlying a potential aquifer in the town of Coventry, and Haddam Meadows State Park in the town of Haddam. Traverse locations on water included the Willimantic River in Coventry and Mansfield Hollow Lake in Mansfield. The penetration depth of the radar signal ranged from about 20 feet in fine-grained glaciolacustrine sediments to about 70 feet in coarse sand and gravel. Some land records in coarse-grained sediments show a distinct, continuous reflection from the water table about 5 to 11 feet below land surface. Parallel reflectors on the records are interpreted as fine-grained sediments. Hummocky or chaotic reflectors are interpreted as cross-bedded or coarse-grained sediments. Other features observed on some of the radar records include the till and bedrock surface. Records collected on water had distinct water-bottom multiples (more than one reflection) and diffraction patterns from boulders. The interpretation of the radar records, which required little or no processing, was verified by using lithologie logs from test holes located along some of the land traverses and near the water traverses.
Long-term followup of anterior cruciate ligament reconstruction using the quadriceps tendon substitution for chronic anterior cruciate ligament insufficiency

At The Hospital for Special Surgery, the quadriceps tendon substitution (QTS), as described by Marshall, was performed for ACL insufficiency from 1973 to 1980. A review of the initial 60 patients with a minimum of 4 years followup (average, 5.5 years) has been concluded. Thirty-eight patients returned for examina tions, and 11 returned questionnaires. Associated me dial procedures were performed in 29 of the 38 exam ined patients. Medial meniscus surgery was performed in 86% and lateral meniscus surgery in 28.9%. At followup, giving way, which was the main preoperative complaint, was eliminated in 30/38 examined and 9/11 questionnaire patients (79%). In the examined group, three patients were clear failures and five had mild transient instability. The pivot shift was present in 17 of 38 (45%) patients examined: 21 patients were neg ative, 9 were 1 + or a grind, 8 were 2+, and none were 3+.We have concluded that the QTS procedure will eliminate symptomatic instability in 79% of our patients, but the high r...
Application of the transverse acoustoelectric effect to studying silicon surface charging upon water adsorption

Water adsorption on a silicon surface in a layered Si-LiNbO3 structure with an air gap is studied using the transverse acoustoelectric effect on surface acoustic waves. A generalized analysis of measurements of the transverse acoustoelectric effect makes it possible to determine the initial band bending of the Si surface, its changes during gas cycles, hence, the sign and charging kinetics of Si upon H2O adsorption. Depending on the properties of the semiconductor surface defects, both the donor and acceptor nature of the interaction of H2O with Si are observed. For samples with a thermal oxide, the donor-type interaction occurs; for samples with a natural oxide, both interaction types take place. Based on the used physical model of oxide charging upon exposure to an adsorbate, a comprehensive methodical approach is proposed, which allows the targeted development of acoustoelectronic structures for sensor applications.
Heat generation associated with synaptic transmission in the mammalian superior cervical ganglion

By use of a thermal detector constructed with a thin polyvinylidene fluoride film (PVDF), heat production in the superior cervical ganglion (SCG) of the guinea pig was examined. A single electric shock applied to the preganglionic nerve evokes a temperature rise of approximately 1.5 x 10(-6) deg. The thermal responses summate when the preganglionic nerve is stimulated repetitively. The amplitude of the thermal response is increased when the preparation is treated with a high Ca2+ medium. Treatment with agents that block ganglionic transmission (high Mg2+, d-tubocurarine, hexamethonium, TTX) reversibly suppresses thermal response. It is thus concluded that the thermal responses described in this paper are generated by the physico-chemical events underlying postsynaptic electrogenesis in the SCG cells.
BeeSim: leveraging wearable computers in participatory simulations with young children

New technologies have enabled students to become active participants in computational simulations of dynamic and complex systems (called Participatory Simulations), providing a "first-person" perspective on complex systems. However, most existing Participatory Simulations have targeted older children, teens, and adults assuming that such concepts are too challenging for younger age groups. This paper, by contrast, presents a design for a Participatory Simulation, called BeeSim, which makes use of wearable computers and targets young children (7-8 years old) to model the behaviors of honeybee nectar collection. In our preliminary user studies, we found that BeeSim contributed to systems understanding and more easily managed group dynamics.
Analog Sensor Based Testing of Phase-Locked Loop Dynamic Performance Parameters

Phase-locked loops are used to synthesize frequency sources for RF conversion and IO clocks for data synchronization, and serve as core building blocks for communication systems. Consequently, testing of PLL loop performance is critical for guaranteeing the reliability of the underlying communication systems. In this paper, a testing method based on loop triggering and use of low-cost built-in analog sensors (small number of transistors) to accurately predict phase-locked loop dynamic parameters is proposed. The sensors are designed in such a way that the sensor responses show strong statistical correlation with the PLL parameters being tested. Accordingly, supervised learners are "trained" to predict the required PLL parameters from the observed sensor response. A PLL is designed and simulated in closed loop over PVT corners in order to validate the testing mechanism. Parameters including charge pump current, VCO gain, bandwidth, phase margin, and locking time are predicted accurately and concurrently over these PVT corners to prove the viability of the proposed test method.
Calculation of Couplings and Energy-Transfer Pathways between the Pigments of LH2 by the ab Initio Transition Density Cube Method

A practical method for accurate evaluation of the Coulombic contribution to the electronic coupling for energy transfer at any donor−acceptor separation is reported. The method involves the exact interaction between transition densities of each chromophore which are calculated ab initio and may include electron correlation. The method is used to calculate coupling strengths between the pigments of the bacterial light-harvesting complex, LH2, and to compare with results using the ideal dipole approximation (IDA). The results suggest that the relatively symmetric transitions of bacteriochlorophyll a (Bchla) pigments are reasonably well described by the IDA for separations >15 A, although deviations are significant at smaller separations. The less symmetric transition of the twisted carotenoid pigment is rather poorly described by the IDA and shows significant deviation even at separations of well over 20 A. The calculated coupling strengths are combined with estimates of the spectral overlap integral to est...
Nucleation reactions in undercooled liquids

Abstract The amount of liquid undercooling is an important factor in determining solidification microstructure development by exposing nucleation reactions that yield an initial phase selection and by controlling morphological evolution during rapid crystal growth. At high undercooling the nucleation of an equilibrium phase may be superseded by metastable product structures to produce a transition in solidification kinetics that is often controlled by heterogeneous nucleation. In this case the use of metastable phase diagrams is important for the interpretation and predicted of nucleation reaction structures and pathways for phase formation. While the study of homogeneous nucleation requires a sample free from all external nucleants, the study of heterogeneous nucleation requires a sample which contains only well-known and characterized nucleants. With alloys samples and in melts with dispersed particles, droplet experiments may be designed to expose known nucleant surfaces to the undercooled liquid. Even with known catalysts a multiplicity of nucleant sites is observed indicating a hierarchy of potency which is influenced by kinetic effects. A model analysis of the atomistic events controlling the heterogeneous nucleation reactions and a relative ranking of potency provides some insight into the dynamics of catalysis mechanisms operating at high undercooling. These features can be highlighted by examples of several types of reaction paths to provide a perspective on nucleation reactions and microstructure control.
Art, Optics and History: New Light on the Hockney Thesis

David Hockney's recent book Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters argues that 15th century painters employed optical devices to achieve realistic portraiture. A reexamination of the history of optical projection techniques raises problems for Hockney's provocative hypothesis.