cssi/SciSciGPT-SciSciNet huggingface dataset:
Competition between cutaneous active vasoconstriction and active vasodilation during exercise in humans

Cutaneous vasoconstriction occurs in response to the initiation of dynamic exercise in hyperthermia. To find whether this response was due to increased vasoconstrictor activity or to withdrawal of active vasodilator activity, blood flow monitoring with laser-Doppler flowmetry (LDF) was combined with the local iontophoresis of bretylium. Each of six male subjects had two forearm sites treated with bretylium for selective local blockade of noradrenergic vasoconstrictor nerves in skin. LDF was monitored at those sites and at two adjacent untreated sites. Mean arterial pressure (MAP) was measured, and cutaneous vascular conductance (CVC) was calculated as LDF/MAP. After iontophoresis, subjects underwent 3 min of cold stress (water-perfused suits) to verify vasoconstrictor blockade. CVC at untreated sites fell by 35.9 +/- 3.1% (P less than 0.01) and at bretylium-treated sites was not significantly changed (P greater than 0.10). During strenuous exercise in normothermia, CVC at untreated sites fell by 16.1 +/- 4.1% (P less than 0.05) and was unchanged at bretylium-treated sites (+12.7 +/- 6.6%, P greater than 0.05). Whole body heat stress was then applied. When exercise was repeated in hyperthermia, CVC at untreated sites fell by 11.6 +/- 3.8% (P less than 0.05) but was not significantly changed at bretylium-treated sites (+3.6 +/- 3.0%, P greater than 0.30). Following return to normothermia, cold stress verified the persistence of the blockade. We conclude that exercise initiation causes a cutaneous vasoconstriction largely or entirely due to enhanced active vasoconstrictor tone in both normothermia and hyperthermia. Little or no role in this response can be ascribed to reduced active vasodilator activity.
Ex post facto Monte Carlo variance reduction

The variance in Monte Carlo particle transport calculations is often dominated by a few particles whose importance increases manyfold on a single transport step. This paper describes a novel variance reduction method that uses a large importance change as a trigger to resample the offending transport step. That is, the method is employed only after (ex post facto) a random walk attempts a transport step that would otherwise introduce a large variance in the calculation. Improvements in two Monte Carlo transport calculations are demonstrated empirically using an ex post facto method. First, the method is shown to reduce the variance in a penetration problem with a cross-section window. Second, the method empirically appears to modify a point detector estimator from an infinite variance estimator to a finite variance estimator.
Ingested Fat Oxidation Contributes 8% of 24-h Total Energy Expenditure in Moderately Obese Subjects

The role of ingested fat in the etiology of obesity is controversial. The aims of this study were to determine the contributions of ingested fat oxidation to: 1) 24-h total energy expenditure (TEE), and 2) substrate oxidation during acute stationary cycle exercises in adult humans. Healthy, moderately obese (n = 18; BMI = 31 +/- 1 kg/m2) subjects (8 men; 10 women) were each studied in a whole-room calorimeter for 24 h. They were fed mixed meals (55, 30, and 15% as energy from carbohydrate, fat and protein, respectively) to maintain energy balance. Each subject performed 1255-kJ cycle exercises at 50% VO2max in the calorimeter. Study test meal fat was labeled with carbon-13 (13C). Ingested fat oxidation was estimated from breath 13CO2 excretion and the subject's chamber CO2 production. Total fat and carbohydrate oxidations were estimated from nonprotein respiratory quotient (NP-RQ) values. Endogenous fat oxidation was estimated as the difference between total fat and ingested fat oxidations. TEE was estimated from gas exchanges; 28 +/- 3% of ingested fat was oxidized and it provided 8 +/- 1% of 24-h TEE. During cycle exercises, ingested fat provided 50% of total fat oxidized and 13.0 +/- 2% of energy expended. Endogenous fat oxidation contributed 10.4 +/- 3% of energy expenditure during cycle exercises. This study extended to 24-h observations of previous studies that lasted 6-9 h on ingested fat oxidation in humans. Understanding the factors that promote ingested fat oxidation could lead to more effective obesity intervention programs.
Women in the Olympic Movement: Advancing Women's Roles through Education

Abstract The Olympics have a much needed educational role: to teach men and women about the roles and opportunities which women have had and will have as participants and administrators within the Olympic movement.
Vasopressin antagonism: A future treatment option in heart failure

Arginine vasopressin plays an important role in volume homeostasis. Patients with heart failure have chronically elevated plasma vasopressin concentrations which may contribute to their clinical syndrome of fluid retention. Recently, a number of agents have been developed to antagonize the effects of vasopressin by targeting its V1a and V2 receptors, which are involved in vascular tone and free water regulation, respectively. Two vasopressin antagonists, in particular, tolvaptan and conivaptan, have shown promise in animal studies and small-scale human trials. The following is a review of current experimental and clinical studies using vasopressin antagonists and their potential role in the treatment of heart failure.
Liquid chromatographic analysis of propafenone enantiomers in human plasma.

Abstract A convenient and sensitive high-performance liquid chromatographic method for analysis of the enantiomers of propafenone (PPF) in human plasma was developed. Racemic propafenone and (− )-ephedrine (internal standard) were first extracted from plasma samples into a mixture of hexane-2-propanol-heptafluorobutanol (95:5: 1.25, v/v). After evaporation of the organic layer, the samples were derivatized with R (− )-naphthylethyl isocyanate. The derivatization reached its maximum within 30 s at room temperature with an efficiency of 93.9 ± 2.8% (mean ± S.D.). The formed diastereomers were subsequently separated on a silica column with a mobile phase of hexane-2-propanol-isobutanol (96: 2: 2, v/v ) at a flow-rate of 1.5 ml/min. The ultraviolet detection wavelength was set at 220 nm. Using 1 ml plasma, the detection limit was 6.25 ng/ml for the propafenone enantiomers. The assay was successfully employed to measure propafenone enantiomers in plasma samples of a healthy subject after oral administration of a single 150-mg dose of the racemate.
Whither French Planning

I. Introduction, 537. — II. The "openness" of national economies, 538.— III. The foreign trade sector in French planning, 541. — IV. The implications of the uncertainty introduced by foreign trade into the planning process, 544. — V. The stabilization policy, 547. — VI. Problems of maintaining price stability and ensuring the financing of private investments, 550. — VII. Conclusion, 554.
Occasional Reinforced Responses During Extinction Can Slow the Rate of Reacquisition of an Operant Response.

Abstract Three experiments with rats examined reacquisition of an operant response after either extinction or a response-elimination procedure that included occasional reinforced responses during extinction. In each experiment, reacquisition was slower when response elimination had included occasional reinforced responses, although the effect was especially evident when responding was examined immediately following each response-reinforcer pairing during reacquisition (Experiments 2 and 3). An extinction procedure with added noncontingent reinforcers also slowed reacquisition (Experiment 3). The results are consistent with research in classical conditioning (Bouton, M. E., Woods, A. M., & Pineno, O. (2004). Occasional reinforced trials during extinction can slow the rate of rapid reacquisition. Learning & Motivation, 35 , 371–390) and suggest that rapid reacquisition after extinction is analogous to a renewal effect that occurs when reinforced responses signal a return to the conditioning context. Clinical implications are also discussed.
An immunization model for a heterogeneous population

A model for the spread of an infectious disease for which recovery gives temporary or permanent immunity is analysed. A heterogeneous population is divided into homogeneous groups in which immunization of newborns and of susceptibles of all ages is possible. Births and deaths occur at equal rates in each group and all newborns are susceptible. The threshold criterion obtained for the nonlinear differential equation model can be used to determine the immunization rates which will cause the disease to die out.
Board Design Influence on BGA Mechanical Reliability

With the technology trend moving towards faster, smaller, and cheaper products, the consumer electronics industry is using more and more high density fine pitch BGA components in a lead-free environment. This has created additional board-level solder joint mechanical reliability challenges. Current literature studies mostly focus on the impact of component design features on BGA solder joint reliability. Very little information is available on board design factor impact on BGA mechanical reliability. This paper highlights the results of our study on the sensitivity of three critical board assembly design factors on BGA solder joint interconnect reliability under mechanical shipping stresses. The results from this study showed high sensitivity to the component location on the board, board trace routing orientation under the component, component enabling heat sink retention mechanism design, and neighboring component heat sink mass. The data collection also showed multiple failure modes including BGA solder joint cracks, PCB pad craters, and PCB trace cracks. Finite element analysis (FEA) modeling results correlated well with empirical data collection and provided additional insight into the physics behind the failures. In conclusion, the paper provides design for reliability (DFR) recommendations to proactively identify high risk bend-line zones to prevent BGA and PCB failures through predictive modeling. This methodology enables board designers to optimize electrical and thermal design and build a mechanically reliable product.
Comparison of dose distribution with different techniques of total skin electron beam therapy

Dose distribution for multiple field and rotational technique total skin electron beam therapy was studied in a Rando-Alderson phantom. 6 MeV beam from a linear accelerator was degraded to 3.2 MeV and the depth dose measurements were made at 3 m similar to clinical set-up. Both thermoluminescence dosimeters and film dosimetry were used to estimate the dose distribution at various points in the phantom. The differences in the depth dose distribution with various techniques of total skin electron beam therapy are discussed.
Computer solution of gel–crosslink relations

Use of the Wesslau molecular weight distribution equation in the equations relating production of gel to total radiation dose leads to equations that can be solved only by means of computer techniques. This solution has been carried out for a number of initial values of the weight-average to number-average molecular weight ratios and for a number of ratios of chain degradation G values to crosslink G values. It is shown that the initial slope of the curve of s + s1/2 versus rg/r, where s is the soluble fraction after a dose r, and rg is the dose to the gel point, can be related to the type of initial molecular weight distribution in the polymer. For the first time definite evidence of an increase of the crosslinking rate with dose has been obtained.
A rapid method for mRNA detection in single-cell biopsies from preimplantation-stage bovine embryos

Abstract Major questions concerning the control of development and gene expression at the cellular level are still unanswered. Nowhere is this more evident than during the earliest stages of development and embryogenesis. This study describes the detection of specific gene transcripts in single cells derived from bovine embryos. Following in vitro fertilization (IVF) and in vitro culture (IVC) of bovine embryos, small groups of cells and even single blastomeres from 32 to 64-cell embryos were micromanipulated into individual tubes for analysis of cytoplasmic RNAs. Reverse transcriptase-PCR was applied to cell lysates for the amplification of β-actin mRNA transcripts. Primers were designed to flank an intron expected to be present within genomic DNA sequences, thus allowing for simple differentiation between DNA- and RNA-derived amplification products. Using a 50-cycle amplification profile, a 260 bp band could be seen as a PCR product derived from a single blastomere following electrophoresis in an ethidium bromide-stained agarose gel. The identity of the band was verified by DNA sequence determination and diagnostic restriction digestion. Lysates derived from single blastomeres in this way have been used for simultaneously phenotyping multiple RNA products. This capability allows the spatial analysis of gene expression and development within embryos from the earliest stages of cellular differentiation.
Thermodynamics and dissociation constants of carboxylic acids at high ionic strength and temperature

Abstract Dissociation constants (p K a ) of oxalic, iminodiacetic, citric, nitrilotriacetic, ethylenediaminetetraacetic, trans-1,2 diaminocyclohexanetetraacetic acid and diethylenetriaminepentaacetic acid have been determined potentiometrically using a glass electrode at an ionic strength of 6.60 m (NaClO 4 ) and temperatures of 0–60 °C. The constants of iminodiacetic, nitrilotriacetic and diethylenetriaminepentaacetic acid were measured at 25 °C at ionic strengths from 0.30 to 6.60 m (NaClO 4 ). The thermodynamic parameters for the dissociation of these carboxylic acids were derived from the temperature dependence of the dissociation constants. The Specific Ion Interaction Theory (SIT) and the Parabolic model successfully described the ionic strength dependencies of the p K a values. The variation of the p K a values at high ionic strengths as a function of the type and concentration of supporting electrolyte is discussed and compared with literature data.
Joint determination of 40K decay constants and 40Ar∗/40K for the Fish Canyon sanidine standard, and improved accuracy for 40Ar/39Ar geochronology

Abstract 40Ar/39Ar and K–Ar geochronology have long suffered from large systematic errors arising from imprecise K and Ar isotopic data for standards and imprecisely determined decay constants for the branched decay of 40K by electron capture and β− emission. This study presents a statistical optimization approach allowing constraints from 40K activity data, K–Ar isotopic data, and pairs of 238U–206Pb and 40Ar/39Ar data for rigorously selected rocks to be used as inputs for estimating the partial decay constants (λe and λβ) of 40K and the 40Ar∗/40K ratio (κFCs) of the widely used Fish Canyon sanidine (FCs) standard. This yields values of κFCs = (1.6418 ± 0.0045) × 10−3, λe = (0.5755 ± 0.0016) × 10−10 a−1 and λβ = (4.9737 ± 0.0093) × 10−10 a−1. These results improve uncertainties in the decay constants by a factor of >4 relative to values derived from activity data alone. Uncertainties in these variables determined by our approach are moderately to highly correlated (cov(κFCs, λe) = 7.1889 × 10−19, cov(κFCs, λβ) = −7.1390 × 10−19, cov(λe, λβ) = −3.4497 × 10−26) and one must take account of the covariances in error propagation by either linear or Monte Carlo methods. 40Ar/39Ar age errors estimated from these results are significantly reduced relative to previous calibrations. Also, age errors are smaller for a comparable level of isotopic measurement precision than those produced by the 238U/206Pb system, because the 40Ar/39Ar system is now jointly calibrated by both the 40K and 238U decay constants, and because λe(40K)
Structural analysis of author vector space in the field of information sciences

In this poster we analyze the structure of author relationships using structural equation modeling (SEM). A structural model of four research areas and associated authors was examined in the author vector space in information sciences. The SEM result confirmed that the selected authors were adequately explained by their specific research area in the vector space based on author publications. In addition, we found that the research areas of “Information retrieval” and “Webometrics & Search log analysis” were closely related to each other.
LINKED IN VIVO EXPRESSION OF SOLUBLE INTERLEUKIN-4 RECEPTOR AND INTERLEUKIN-4 IN MURINE SCHISTOSOMIASIS

Soluble interleukin-4 receptors (sIL-4R) are truncated IL-4R molecules that are secreted into biological fluids. To gain an insight into the mechanisms that control sIL-4R synthesis in vivo and their role in the regulation of immune responses, the expression and secretion of sIL-4R in mice infected with Schistosoma mansoni was studied. Splenocytes from infected animals responded to schistosomal antigen preparations with increased production of both IL-4 and sIL-4R. The synthesis of sIL-4R by spleen cells peaked at 8 weeks following infection and coincided with maximum levels of sIL-4R in serum and sIL-4R-specific mRNA in the liver of infected mice. The expression of IL-4-specific mRNA in the liver was different from that of IL-4R, reaching its peak approximately 2 weeks earlier. A relationship between sIL-4R production and the development and activation of Th2 cells was suggested by the findings that: (a) in vivo administration of anti-IL-4 antibodies (11B11) impaired the ability of splenic cells to secrete either IL-4 or sIL-4R; and (b) splenic cells from mice vaccinated with irradiated cercariae, which tend to develop much weaker Th2 responses than mice injected with live cercariae, expressed reduced levels of sIL-4R when challenged with schistosomal antigens. Moreover, a direct role for IL-4 in regulating the expression of sIL-4R was suggested by the ability of anti-IL-4 antibodies to inhibit sIL-4R synthesis in vitro. These data provide the first evidence demonstrating that the production of sIL-4R in vivo is up-regulated during immune responses, especially during those characterized by the development and activation of Th2 cells and IL-4 secretion. The association between sIL-4R and IL-4 syntheses is consistent with a potential role for sIL-4R in the regulation of IL-4 activity in vivo.
Blood adrenocorticotropin (ACTH) in children with rheumatic fever.

The concentration of adrenocorticotropic hormone (ACTH) in the circulating blood has been measured in normal human subjects and in individuals with a few disease entities. Paris et al. (1) recently reviewed the literature concerning ACTH in the blood of human subjects, as determined by adrenal ascorbic-acid depletion assay technics. They attribute most of the wide variations reported for ACTH concentration to differences in the blood extraction technics. The oxycellulose extraction method (2) yields results compatible with those found when plasma alone is assayed for its ACTH content (1). Neither of these procedures has sufficient sensitivity to detect the concentration of blood ACTH in most normal human subjects. However, they are capable of detecting the elevated concentrations which occur in patients with certain pathologic conditions.
CARBOHYDRATE METABOLISM IN PREGNANCY: THE DEGRADATION OF INSULIN BY EXTRACTS OF MATERNAL AND FETAL STRUCTURES IN THE PREGNANT RAT1

Cell-free extracts have been prepared from livers, placentas, and fetuses of pregnant rats on day 12, 15, 18 and 21 of gestation and from livers of nonpregnant control animals. With the use of I13l-insulin and nitrogen reference standards, the insulin-degrading capacities of these structures have been compared on the basis of activity per unit mass (specific activity) and activity per total tissue (total potential activity). It has been demonstrated that mechanisms for the proteolytic degradation of insulin are present within the conceptus throughout gestation. Placental specific activity remained constant and at all times equal to that of maternal and control liver. Thus, for pooled placentas, total potential activity paralleled the increase in placental mass to reach onethird the value of maternal liver at term. Fetal specific activity increased late in pregnancy to approximately twice the level found in the other tissues. In isolated fetal parts, activity was greatest in feta skin. At term, the total p...
Progressive changes in positive active material over the lifetime of a lead–acid battery

Abstract Time-of-flight neutron diffraction for a series of lead–acid battery positive plate samples has shown that β-PbO 2 is not stoichiometric, but has a deficiency of Pb relative to oxygen giving Pb 0.92 O 2 to Pb 0.96 O 2 . The Pb vacancies cause a charge deficiency that is balanced by crystallographic hydrogen on a disordered site. The position of hydrogen is typical of hydrogen bonding as has been previously proposed based on nuclear magnetic resonance spectra. With either rapid or conventional charging, the amount of hydrogen substitution decreases and the β-PbO 2 tends toward a stoichiometric composition at battery failure. High resolution SEM imaging of these and other battery samples shows a progressive change in the morphology of β-PbO 2 and these changes appear to be the same for both rapid or conventional charging. The morphology progresses from elongated, well-formed crystals to equidimensional crystals to dense clusters of crystals with a consequent reduction in surface area. Neither stoichiometry nor morphology changes necessarily contribute to battery failure, but both progressively change over the cycle life of the battery.
The Vermont oxford neonatal encephalopathy registry: rationale, methods, and initial results

In 2006, the Vermont Oxford Network (VON) established the Neonatal Encephalopathy Registry (NER) to characterize infants born with neonatal encephalopathy, describe evaluations and medical treatments, monitor hypothermic therapy (HT) dissemination, define clinical research questions, and identify opportunities for improved care. Eligible infants were ≥ 36 weeks with seizures, altered consciousness (stupor, coma) during the first 72 hours of life, a 5 minute Apgar score of ≤ 3, or receiving HT. Infants with central nervous system birth defects were excluded. From 2006–2010, 95 centers registered 4232 infants. Of those, 59% suffered a seizure, 50% had a 5 minute Apgar score of ≤ 3, 38% received HT, and 18% had stupor/coma documented on neurologic exam. Some infants experienced more than one eligibility criterion. Only 53% had a cord gas obtained and only 63% had a blood gas obtained within 24 hours of birth, important components for determining HT eligibility. Sixty-four percent received ventilator support, 65% received anticonvulsants, 66% had a head MRI, 23% had a cranial CT, 67% had a full channel encephalogram (EEG) and 33% amplitude integrated EEG. Of all infants, 87% survived. The VON NER describes the heterogeneous population of infants with NE, the subset that received HT, their patterns of care, and outcomes. The optimal routine care of infants with neonatal encephalopathy is unknown. The registry method is well suited to identify opportunities for improvement in the care of infants affected by NE and study interventions such as HT as they are implemented in clinical practice.
Hand-Assisted Laparoscopic Partial Nephrectomy Without Formal Collecting System Closure: Perioperative Outcomes in 104 Consecutive Patients

Abstract Background and Purpose: Laparoscopic partial nephrectomy (LPN) paralleling open techniques, particularly closure of the collecting system, can be technically challenging for the novice lap...
The composition of several commercial rapid tube and saline anti-D reagents.

The albumin concentration in five commercially available slide and rapid tube anti-D sera varied from 15.4 to 21.9 gm/dl and in saline anti-D reagents varied from 2.64 to 5.14 gm/dl. In both rapid tube and saline anti-D sera, the predominant immunoglobulin class was Ig-G. The anti-D activity of saline anti-D sera resided in both the Ig-G and Ig-M classes.
Type V Collagens of the Human Placenta: Trimer α-Chain Composition, Ultrastructural Morphology and Peptide Analysis

The alpha-chain trimer composition of type V collagen preparations from human placental membrane and villi was determined by two-dimensional electrophoresis on a non-denaturing polyacrylamide gel system followed by electrophoresis in the presence of sodium dodecylsulfate. In preparations isolated from placental membranes pure type V collagen was found with the alpha-chain composition [alpha 1(V)]2 alpha 2(V). In preparations from placental villi two different collagen trimers could be identified with alpha-chain compositions [alpha 1(V)]2 alpha 2(V) and [alpha 3(V)]3. Two-dimensional peptide maps after chymotryptic digestion of the various alpha-chain revealed distinct patterns for alpha 1(V), alpha 2(V) and alpha 3(V) suggesting unique structures for all three alpha-chains. Shadowing of the two collagen preparations with carbon-platinum by the rotary shadowing technique allowed the visualization of the individual molecules. In the placental membrane preparations, a uniform species of molecules was present while in placental villi preparations the same elongated form of collagen was found together with larger aggregates presumably containing molecules with the alpha 3-chain component. These data are interpreted to indicate that so-called type V collagen, at least in preparations from placental villi, contain two distinct collagen molecules.
Epitaxial growth of high-Tc superconducting Tl-Ca-Ba-Cu-O films by liquid phase epataxial process

Abstract Tl-Ca-Ba-Cu-O epitaxial films have been successfully grown on (001) MgO substrate by liquid phase epitaxial (LPE) process. The as-grown films showed an onset of superconductivity at about 140 K and zero resistance at 111 K. X-ray diffraction analysis suggests the films to be highly preferentially oriented with the c -axis perpendicular to the film surface. Observation from transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) revealed the presence of both Tl-Ca 2 Ba 2 Cu 3 O y and TlCa 2 Ba 3 Cu 4 O y phases.
Electron-blocking mechanisms at the hole transport layer-emissive layer interface in polymer light-emitting diodes. Enhanced device performance with a novel electron-blocking interlayer

The interface between the hole transport layer (HTL) and emissive layer (EML) in polymer light-emitting diodes (PLEDs) has attracted intense research attentioin since the initial discovery of PLEDs in 1989. In this contribution, we analyze the electron-blocking properties of various HTL at this interface and their effect on PLED device performance. We find that poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) - a conventional PLED HTL - does not possess optimum electron-blocking properties and that PLED device performance can be significantly enhanced by inserting a new type of electron-blocking layer (EBL) between the PEDOT-PSS HTL and EML. The new EBLs developed in this study consist of two major components: a siloxane-derivatized, crosslinkable, TPD-like triarylamine hole-transporting material, such as 4,4’-bis[(p-trichlorosilylpropylphenyl)phenylamino]biphenyl (TPDSi 2 ), and a hole-transporting polymer, such as poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl) diphenylamine) (TFB). TPDSi 2 undergoes crosslinking in air and rendering the TPDSi 2 + TFB blend insoluble. With the TPDSi 2 + TFB EBL inserted between PEDOT-PSS and BT layers, PLED device current density is reduced, device light output and current efficiency are dramatically increased (maximum current efficiency ~ 17 cd/A). Our result shows: 1) insufficient electron-blocking by PEDOT-PSS is another reason for the poor performance of PEDOT-PSS/BT based devices; 2) PLED device performance can be dramatically enhanced with a triarylamine siloxane-based EBLs.
Genetic Insights Into Pyralomicin Biosynthesis in Nonomuraea spiralis IMC A-0156

The biosynthetic gene cluster for the pyralomicin antibiotics has been cloned and sequenced from Nonomuraea spiralis IMC A-0156. The 41-kb gene cluster contains 27 ORFs predicted to encode all of the functions for pyralomicin biosynthesis. This includes non-ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) required for the formation of the benzopyranopyrrole core unit, as well as a suite of tailoring enzymes (e.g., four halogenases, an O-methyltransferase, and an N-glycosyltransferase) necessary for further modifications of the core structure. The N-glycosyltransferase is predicted to transfer either glucose or a pseudosugar (cyclitol) to the aglycone. A gene cassette encoding C7-cyclitol biosynthetic enzymes was identified upstream of the benzopyranopyrrole-specific ORFs. Targeted disruption of the gene encoding the N-glycosyltransferase, prlH, abolished pyralomicin production and recombinant expression of PrlA confirms the activity of this enzyme as a sugar phosphate cyclase (SPC) involved in the formation of the C7-cyclitol moiety.
Motivation-participation conflation: Investigating response bias in intra-semester longitudinal class surveys

Early analysis does not support a link between students' motivation levels and their survey participation rates, suggesting that repeated sampling throughout a semester may be more capable of documenting a representative cross-section of student experiences than we originally expected.
Frequency dependence of the electrical conductivity of MClO4 (M = K, Rb, Cs) compounds

The frequency dependence of the electrical conductivity of potassium perchlorate, rubidium perchlorate, and cesium perchlorate is discussed. Frequencies in the range 50 Hz to 1 kHz and temperatures from ambient to ≈ 620 K are included for this study. Similarities and differences in the temperature- and frequency-dependent electrical conductivity behavior of the above compounds and the effect of ionic radii on the activation energies for charge carrier transport are highlighted in the present study. Es wird die Frequenzabhangigkeit der elektrischen Leitfahigkeit von Kaliumperchlorat, Rubidium-perchlorat und Casiumperchlorat diskutiert. Dabei werden Frequenzen im Bereich von 50 Hz bis 1 kHz und Temperaturen von Zimmertemperatur bis ≈ 620 K benutzt. Ahnlichkeiten und Unterschiede der Temperatur- und Frequenzabhangigkeit der elektrischen Leitfahigkeit der erwahnten Verbindungen und der Einflus der Ionenradien auf die Aktivierungsenergien fur den Ladungs-tragertransport werden in der Untersuchung herausgestellt.
High-resolution mapping of rural poverty and famine vulnerability in the Sahel: a possible approach for the Republic of Niger

Conventional approaches to mapping poverty and vulnerability rely on statistical techniques for analyzing national census results in conjunction with much smaller auxiliary data sets. The resulting low-resolution maps offer only limited explanations for the causes of poverty/vulnerability, especially those related to the physical environment. Scientists have mapped land cover performance (or “land degradation” or “desertification”) on national scales using satellite remote sensing, but their efforts have rarely been incorporated into poverty/vulnerability mapping endeavors. This paper describes an alternative, comparatively low-cost approach that could make possible poverty/vulnerability mapping at high resolution across the inhabited territories of entire Sahelian countries. The new hybrid approach calls for close collaboration between a team of remote sensing scientists and a team of field workers engaged in social science, earth science, and biomedical research. Maps produced through this approach should help in targeting programs to alleviate poverty and could improve the efficacy of famine early warning and mitigation.
Dual energy imaging enhancement with fuzzy logic

In medical imaging applications, it is often necessary to enhance the bone-background contrast to improve the visibility of anatomical landmarks. Because of the low contrast nature of these images, many classical image enhancement techniques have met with limited success. In this paper, the image enhancement problem is treated as a natural extension to the image segmentation. We make specific use of the energy dependency of the x-ray attenuation characteristics to establish the basis for classification. The inherent ambiguity or vagueness in the bone-background classification is handled nicely with the fuzzy logic approach. The membership grade is generated with a generalized adaptive median filter to achieve the noise suppression and edge preservation. The final image is obtained by a non-linear gray scale mapping. Phantom and clinical studies have demonstrated the effectiveness of this approach. Some limitations of the approach are also discussed in the paper.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A new caprylic alcohol glycoside from Circaea lutetiana ssp. canadensis

A new alcohol glycoside, 1-octyl α-D-arabinofuranosyl-(1→6)-β-D-glucopyranoside (1), four known compounds including three phenolics, isovitexin, astragalin, and methyl gallate 3-O-β-D-(6'-O-galloyl)-glucopyranoside (2), and the terpene glucoside icariside B 2 (3) have been isolated from the aerial parts of Circaea lutetiana ssp. canadensis.
Elimination of Hemorrhage Following Right Atrial Catheter Removal: A Simple Technique

A simple technique to prevent postoperative bleeding following removal of a right atrial catheter is described. This technique involves reinforcing the catheter exit site with a Silastic Vesseloop.
Genetic Variation for Potato Tuber Micronutrient Content and Implications for Biofortification of Potatoes to Reduce Micronutrient Malnutrition

Micronutrients are crucial to healthy growth and development, yet a large proportion of the world’s population suffers from micronutrient deficiencies. Biofortification of staple foods has tremendous potential to alleviate these deficiencies. Potato production in developing countries is increasing rapidly, and therefore, biofortification of potatoes for essential micronutrients may be feasible. The purpose of this study was to determine the amount of genetic variation for micronutrient content in potato germplasm. Eighteen potato clones, consisting of ‘Atlantic’ and 17 4x-2x hybrids between S. tuberosum and diploid hybrids of S. phureja-S. stenotomum, were grown in three locations (NC, VA, NJ) 2 years (2001, 2002). Samples of tuber tissue were analyzed for copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). There were significant differences among clones for Cu, Fe, Mn and Zn. Clone x environment interactions were significant for Cu and Zn. Broad-sense heritability and its 95 % confidence interval for Cu was 0.65 (0.50–0.89); Fe was 0.49 (0.27–0.84); Mn was 0.84 (0.82–0.96); and Zn was 0.82 (0.73–0.94). Genetic variation for these four micronutrients is large, suggesting that the micronutrient content of potatoes can be improved through breeding.
Methadone treatment induces attenuation of cerebrovascular deficits associated with the prolonged abuse of cocaine and heroin.

Opiate replacement therapy has been useful in reducing heroin use and in keeping patients in treatment programs. However, neuropsychological and neurophysiological effects of this treatment regimen have not been evaluated systematically. To determine whether methadone treatment reduces the magnitude of cerebral blood flow alternations in polysubstance (heroin and cocaine) abusers, we compared blood flow parameters in control subjects (n=26), polysubstance abusers (n=28) maintained on methadone for 24 weeks, and polysubstance abusers (n=22) who were not seeking treatment. Blood flow velocity was recorded from the anterior and middle cerebral arteries using transcranial Doppler sonography on an outpatient visit. The pulsatility index, a measure of cerebrovascular resistance, was significantly (p<0.05) increased in both groups of polysubstance abusers compared to control subjects. Increased pulsatility in the two groups of substance abusers suggests constriction of the small cortical arteries. Nevertheless, the methadone-maintained polysubstance abusers had significantly lower pulsatility values than the nontreatment substance-abusing group. These findings suggest that maintenance on methadone might have significant beneficial neurovascular effects on this population of patients.
The Role of Central Bank Independence on Optimal Taxation and Seigniorage

Should inflation be thought of as "just another tax?" The theoretical basis for doing so dates back to Phelps (1973) and has been greatly refined ever since. Since optimal taxation minimizes the deadweight loss by equalizing the marginal distortions of all available taxes, including the inflation tax, a key distinctive theoretical implication obtained by these models is that inflation and tax rates have a positive relationship. While theoretically appealing, empirical studies and virtually no support for this key implication. We show that, considering the role of central bank independence (CBI), it is possible to reconcile the main theoretical implications of models of optimal taxation and seigniorage with the empirical evidence. Different degrees of CBI capture the extent to which monetary policy is effectively controlled by the fiscal authority. Our model generates three testable implications: i) if CBI is low, the optimal relationship between inflation and tax rates is positive, ii) such relationship is a decreasing function of the degree of CBI, and iii) it is negative for high levels of CBI. We show that these hypotheses hold for alternative measures of tax rates, groups of countries, and macroeconomic theories regarding the determination of the level of inflation.
Relationships Between Achievement and Selective Variables in a Chemistry Course for Nonmajors

The main purpose of this study was to investigate the relationships between students' approaches to studying, prior knowledge, logical thinking ability, and gender and their performance in a nonmajors' college freshman chemistry course. Subjects for this study were 220 students (128 females and 92 males) enrolled in the second semester of a freshman chemistry course for nonmajors at a private university in New York State. Instruments used in this study included seven subscales of the Approaches to Studying Inventory and the Test of Logical Thinking (TOLT). The students' grades on an hour-long exam early in the semester were used as measures of the students' prior knowledge, while the semester cumulative final examination scores were used as measures of achievement in chemistry. Students in this study had slightly higher scores on reproducing orientation than on meaning orientation, a pattern that confirms Entwistle and Ramsden's (1983) findings with a similar group of nonmajors. The results of a stepwise multiple regression showed that prior knowledge, TOLT scores, and meaning orientation accounted for 32% of the variance on the final examination scores.
Freezing tolerance of winter wheat plants frozen in saturated soil

Winter wheat is sown in the autumn and harvested the following summer, necessitating the ability to survive subfreezing temperatures for several months. Autumn months in wheat-growing regions typically experience significant rainfall. Hence, the wheat plants usually are exposed to freezing temperatures when they have high moisture content and are growing in very wet soil. Both of these conditions are conducive to freezing stresses different from those that occur under lower moisture conditions. This study was conducted to seek genetic variability among winter wheat lines and their progeny in the ability to tolerate freezing in saturated soil. Fully acclimated seedlings in saturated soil were frozen to a narrow range of temperature conditions that resulted in about 50% mortality of the most freezing tolerant lines studied. The temperature of the soil near the crowns of the plants was recorded every 2 min throughout each freezing episode. The following components were then determined for each freezing episode: the amount of time the plants remained in subfreezing temperature before all freezable water had been converted to ice; the rate of cooling from the freezing temperature to the minimum temperature; the minimum temperature; the length of time the plants remained at the minimum temperature; the rate of temperature increase from the minimum to 0 °C after freezing; and the total amount of time the plants were actually frozen. Partial regression analysis revealed the minimum temperature significantly influenced survival in all of the progeny populations, while the other five components significantly influenced survival in some, but not all of the populations, suggesting genotypic differences in the ability to tolerate variation in specific aspects of the freezing process. Evidence from progeny populations suggested that improved freezing tolerance was associated with decreased sensitivity to the length of time held at the minimum temperature and increased responsiveness to the post-freezing warming rate. Further analysis of this kind of variation may enable the genetic combining of sources of tolerance of the stresses imposed by specific components of the freezing process, leading to cultivars with improved tolerance of freezing in saturated soil.
Kinetic effects of a kairomone in moth scales of the European corn borer onTrichogramma nubilale Ertle & Davis (Hymenoptera: Trichogrammatidae)

Role des composants chimiques de l'hote de T.n. dans son comportement de recherche de son hote
An automated descending rate‐intensity self‐stimulation paradigm: Usefulness for distinguishing antidepressants from neuroleptics

Rats with medial forebrain bundle electrodes were trained to self-stimulate during successive no-cue periods in which the stimulating current remained constant for the first ten minutes and then decreased in small steps every two minutes for the next 30 minutes. Control response profiles generated in this manner were compared to drug dose-response profiles. Tricyclic anti-depressants (imipramine, amitriptyline) and neuroleptics (chlorpromazine, haloperidol) suppressed intracranial self-stimulation (ICSS) responding in the fixed (F) and descending (DES) current periods. However, in combination with amphetamine, antidepressants potentiated amphetamine's effect in the DES periods only, whereas neuroleptics blocked amphetamine's effect in the DES periods. Both classes of drugs blocked amphetamine's effect in the F period. On the basis of these results, it is suggested that the ICSS model presented in this report can distinguish between antidepressant and neuroleptic drugs.
Composition, diversity, and height of tree regeneration, 3 years after soil scarification in a mixed-oak shelterwood

Abstract This study reports the effects of soil scarification soon after dissemination of northern red oak (Quercus rubra L.) acorns on species composition, density, height, and diversity of regeneration in a mixed-oak shelterwood in central Pennsylvania, US. Prior to treatment, the understory of the stand had relatively few large stems of oak reproduction and was dominated by less desirable shade tolerant tree species. Three years after treatment, scarified plots had significantly higher density of northern red oak regeneration (34,262 ha−1) reflecting greater first-year germination and survival of acorns (28%) compared to undisturbed control plots (2447 ha−1 and 2%, respectively). Additionally, scarification resulted in 70% lower red maple (Acer rubrum L.) density (5751 ha−1) arising from mortality of advance regeneration and reduced recruitment from seed relative to unscarified control. The tallest reproduction (height class >122 cm) had density reduced by 62% in scarified plots compared to undisturbed controls; however, seedlings in this height class were mostly less desirable shade tolerant species present as advance reproduction before treatment. Scarification also tended to reduce densities of Vaccinium but increased Rubus densities four-fold. Shannon diversity (H′) of tree species decreased in scarified plots reflecting increased relative dominance of northern red oak. This decrease in H′ occurred despite increased species richness and greater seedling density for 14 of 17 species compared to pretreatment values. Soil scarification soon after acorn dissemination in a mixed-oak shelterwood served to inhibit successional momentum toward shade tolerant species through decreased density and height of red maple and increased density and competitive position of oak reproduction.
A comparative study of turbulence models for overset grids

The implementation of two different types of turbulence models for a flow solver using the Chimera overset grid method is examined. Various turbulence model characteristics, such as length scale determination and transition modeling, are found to have a significant impact on the computed pressure distribution for a multielement airfoil case. No inherent problem is found with using either algebraic or one-equation turbulence models with an overset grid scheme, but simulation of turbulence for multiple-body or complex geometry flows is very difficult regardless of the gridding method. For complex geometry flowfields, modification of the Baldwin-Lomax turbulence model is necessary to select the appropriate length scale in wall-bounded regions. The overset grid approach presents no obstacle to use of a one- or two-equation turbulence model. Both Baldwin-Lomax and Baldwin-Barth models have problems providing accurate eddy viscosity levels for complex multiple-body flowfields such as those involving the Space Shuttle.
CHLOROPLAST “DISAPPEARANCE” AS A TOOL FOR STUDYING SOME EFFECTS OF ULTRAVIOLET LIGHT ON PLANTS*

Summary With certain precautions the “disappearance” of guard cell chloroplasts may serve as a quantitative measure of ultraviolet light damage to leaves. Irradiated French bean leaves are still appreciably photoreactivable after 30–60 min in darkness, but eventually they cease to be. This critical time is the same as with irradiated viruses photoreactivated in their hosts. Guard cells seem much less susceptible than other epidermal cells to damage by ultraviolet light because ultraviolet light doses 15 times as great as those that cause collapse of ordinary epidermal cells do not abolish reversible osmotic closure of stomata.