cssi/SciSciGPT-SciSciNet huggingface dataset:
The neuromessenger platelet-activating factor in plasticity and neurodegeneration.

Synaptic activation leads to the formation of arachidonic acid, platelet-activating factor (PAF, 1-O-alkyl-2-acyl-sn-3-phosphocholine) and other lipid messengers. PAF is a potent bioactive phospholipid in synaptic plasticity. PAF enhances presynaptic glutamate release, is a retrograde messenger in long-term potentiation and enhances memory formation. PAF also couples synaptic events with gene expression by stimulating a FOS/JUN/AP-1 transcriptional signaling system, as well as transcription of COX-2 (inducible prostaglandin synthase). Since the COX-2 gene is also involved in synaptic plasticity, the PAF-COX-2 pathway may have physiological significance. Seizures, ischemia and other forms of brain injury promote phospholipase A2 (PLA2) overactivation, resulting in the accumulation of bioactive lipids at the synapse. PAF, under these pathological conditions, behaves as a neuronal injury messenger by at least two mechanisms: (a) enhancing glutamate release; and, (b) by sustained augmentation of COX-2 transcription. These events link PAF with neurodegeneration. The upstream intracellular pathways of signal transduction involved in neuronal or photoreceptor cell apoptosis are not well understood and involve stress sensitive kinases. PAF is a transcriptional activator of the COX-2 gene. BN 50730, a potent intracellular PAF antagonist, blocks COX-2 induction. COX-2 transcription and protein expression are upregulated in the hippocampus in kainic acid induced epileptogenesis. There is a selectively elevated induction of COX-2 (72-fold) by kainic acid preceding neuronal cell death. BN 50730 administered by i.c.v. injection blocks seizure-induced COX-2 induction. Overall, PAF is a dual modulator of neural function and becomes an endogenous neurotoxin when over produced.
Silicon carbide, a high temperature semiconductor

Electronic applications are described that would benefit from the availability of high temperature semiconductor devices. Comparisons are made among potential materials for these devices and the problems of each are discussed. Recent progress in developing silicon carbide as a high temperature semiconductor is described.
Isolation and characterization of PEP5, a gene essential for vacuolar biogenesis in Saccharomyces cerevisiae

pep5 mutants of Saccharomyces cerevisiae accumulate inactive precursors to the vacuolar hydrolases. The PEP5 gene was isolated from a genomic DNA library by complementation of the pep5-8 mutation. Deletion analysis localized the complementing activity to a 3.3-kb DNA fragment. DNA sequence analysis of the PEP5 gene revealed an open reading frame of 1029 codons with a calculated molecular mass for the encoded protein of 117,403 D. Deletion/disruption of the PEP5 gene did not kill the cells. The resulting strains grow very slowly at 37 degrees. The disruption mutant showed greatly decreased activities of all vacuolar hydrolases examined, including PrA, PrB, CpY, and the repressible alkaline phosphatase. Apparently normal precursors forms of the proteases accumulated in pep5 mutants, as did novel forms of PrB antigen. Antibodies raised to a fusion protein that contained almost half of the PEP5 open reading frame allowed detection by immunoblot of a protein of relative molecular mass 107 kD in extracts prepared from wild-type cells. Cell fractionation showed the PEP5 gene product is enriched in the vacuolar fraction and appears to be a peripheral vacuolar membrane protein.
Ischemic Enterocolitis in Pheochromocytoma

The gastrointestinal complications of pheochromocytoma are reviewed in a patient who presented with hypertension, chronic constipation, and distended bowel. It is postulated that excessive levels of blood catecholamines liberated from the pheochromocytoma produced persistent vasoconstriction and resulted in widespread hemorrhagic necrosis of the gut.
Stressors perceived by cardiac surgical patients in the intensive care unit

BACKGROUND Few studies have documented stressors experienced by patients recovering from cardiac surgery in the intensive care unit. Furthermore, research has indicated that nurses' predictions of stressors often are not accurate. Stressors frequently experienced by cardiac surgical patients in the intensive care unit must be clearly identified to enable nurses to predict them, plan interventions to minimize them, and help patients cope. OBJECTIVE To determine what stressors are perceived by cardiac surgical patients while in the intensive care unit. METHODS A descriptive survey design, employing the Intensive Care Unit Environmental Stressor Scale, was used. Patients completed the instrument while on a telemetry unit after transfer from the cardiac intensive care unit at a large regional hospital in the northwestern United States. A nonprobability convenience sample of 43 postoperative first-time cardiac surgical patients was used. RESULTS Presence of oral and nasal tubes was rated as the primary stressor. Loss of control and missing one's spouse were the highest-rated psychological stressors. Overall mean scores for stressor items were low. CONCLUSIONS Our results suggest that interventions reducing stressors enhance the recovery process for cardiac surgical patients.
A calibration procedure for reverberation chambers

This paper documents a calibration procedure for reverberation chambers. The method described was developed as part of an ongoing effort to introduce reverberation chambers into military and commercial standards. This work was conducted in cooperation with both industry and standards organizations. The effort described herein is intended to provide an accurate and economic methodology for calibrating reverberation chambers. The methodology was initially developed and evaluated at the Naval Surface Warfare Center, Dahlgren Division. Follow-on evaluations were conducted at facilities owned and operated commercially.
Tribological Sensitivity of PTFE/Alumina Nanocomposites to a Range of Traditional Surface Finishes

Wear tests were performed with polytetrafluoroethylene (PTFE) + Al 2 O 3 nanocomposites on various manufactured surfaces to determine whether or not the wear resistance of these nanocomposites is a strong function of surface preparation. Four different surface finishes of grade 304 stainless steel counterfaces were used: electropolished (R q = 88 nm), lapped (R q = 161 nm), wet-sanded (R q = 390 nm), and dry-sanded (R q = 578 nm). PTFE + Al 2 O 3 nanocomposites made from powders of roughly 2-20 μm PTFE (matrix) and ∼44 nm Al 2 O 3 (filler) were prepared at filler weight percentages of 0, 1, 5, and 10% and tested on each surface finish. Additionally, 5 wt% 44-nm nanocomposites were compared to identically prepared 5 wt% 80- and 500-nm Al 2 O 3 filled PTFE composites on each surface. Friction coefficients were between 0.12 and 0.19 and wear rates decreased from K = 810 × 10− 6 mm 3 /(Nm) for the 5 wt% 500-nm alumina-filled PTFE on the dry-sanded surface to K = 0.8 × 10− 6 mm 3 /(Nm) for the 5 wt% 80-nm fill...
Grocery Store Beverage Choices by Participants in Federal Food Assistance and Nutrition Programs

Background Sugar-sweetened beverages are a target for reduction in the 2010 Dietary Guidelines for Americans. Concerns have been raised about sugar-sweetened beverages purchased with Supplemental Nutrition Assistance Program (SNAP) benefits. Purpose This paper describes purchases of non-alcoholic refreshment beverages among participants in the U.S. Department of Agriculture's Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and SNAP. Methods Grocery store scanner data from a regional supermarket chain were used to assess refreshment beverage purchases of 39,172 households in January–June 2011. The sample consisted of families with a history of WIC participation in 2009–2011; about half also participated in SNAP. Beverage spending and volume purchased were compared for WIC sampled households either using SNAP benefits (SNAP) or not (WIC-only). Analyses were completed in 2012. Results Refreshment beverages were a significant contributor to expenditure on groceries by SNAP and WIC households. Sugar-sweetened beverages accounted for 58% of refreshment beverage purchases made by SNAP households and 48% of purchases by WIC-only households. Soft drinks were purchased most by all households. Fruit-based beverages were mainly 100% juice for WIC-only households and sugary fruit drinks for SNAP households. SNAP benefits paid for 72% of the sugar-sweetened beverage purchases made by SNAP households. Nationwide, SNAP was estimated to pay at least $1.7 to $2.1 billion annually for sugar-sweetened beverages purchased in grocery stores. Conclusions Considerable amounts of sugar-sweetened beverages are purchased by households participating in WIC and SNAP. The SNAP program pays for most of the sugar-sweetened beverage purchases among SNAP households. The upcoming SNAP reauthorization could be a good time to reconsider the program priorities to align public funds with public health.
Action spectra and quantum yields for nicotinamide--adenine dinucleotide phosphate reduction by chloroplasts.

Abstract The photoreduction of NADP by chloroplasts is observed to occur with a requirement of 2–4 quanta per electron transferred to NADP at wavelengths from 550 to 730 mμ in a 3-(3,4-dichlorophenyl)-1,1-dimethylurea-poisoned system when reduced 2,6-dichlorophenolindophenol is present as electron donor. In the normal reaction, with water as donor, a similar quantum requirement is observed from 550 to 680 mμ, but this rises to approx. 14 quanta per electron at wavelengths longer than 700 mμ. The results are interpreted as reflecting the participation of two pigment systems. Some characteristics of the absorption spectra of the two systems are discussed. The quantum requirements at nearly all wavelengths studied were found to increase linearly with increasing incident light intensity for both reactions. We propose that an activated intermediate of the photosynthetic unit, with an estimated lifetime of 0.05 sec in the normal reduction of NADP by chloroplasts and 0.15 sec in the 3-(3,4-dichlorophenyl)-1,1-dimethylurea-poisoned system, is responsible for this intensity dependence. Small quantasome aggregates prepared from spinach chloroplasts are shown to be nearly half as efficient as intact chloroplasts in the photoreduction of NADP using reduced 2,6-dichlorophenolindophenol. A method is described whereby the absorption spectrum of these quantasome suspensions can be used to determine the true absorption spectrum of chloroplasts at wavelengths where light scattering is predominant.
Molecular Dynamics Free-Energy Simulations of the Binding Contribution to the Fidelity of T7 DNA Polymerase

The relative stability of Watson−Crick and mismatched dNTP·template base pairs in the active site of T7 DNA polymerase (pol T7) was examined using linear-response (LRA) molecular dynamics simulations. The LRA method approximates the relative binding free energies by evaluating average electrostatic and van der Waals energies. The results of these computer simulations and the previous simulations of the human DNA polymerase β (pol β) ternary complex (Florian, J.; Goodman, M. F.; Warshel, A. J. Phys. Chem. B, 2002, 106, 5739) carried out at the same theoretical level were compared. It was found that pol T7 provides a larger binding contribution to the replication fidelity than pol β by discriminating more effectively against mismatches that are most probable to occur in the neutral anti−anti configurations. The selectivity of the pol T7 in the binding step is largely determined by the template−dNTP interactions. These interactions are strengthened by the preorganized protein active site and the contribution...
Exploring Alternative Visions in Media

Alternative media offerings play an important role in any society given that they provide alternative information and representational approaches that are not typically encountered in the majority ...
Turbulent flame propagation in a homogeneous gas mixture

Abstract This paper predicts turbulent flame velocities theoretically and compares the results with experimental data. The turbulent flame model is a one-dimensional inviscid flame propagating in a tube at constant velocity and pressure through a premixed combustible gas. The chemical kinetics is taken to be a direct one-step, first-order irreversible exothermic reaction subject to an Arrhenius thermal dependence. The time-mean average concept is used to describe the turbulent flow. Isotropic turbulence of low intensity of turbulence and small scale of turbulence is also adopted. The conservation of species and energy equations are solved by two different numerical integration schemes; both methods are shown to yield similar results. The following information can be obtained from the equations: the laminar or turbulent flame velocity, and the temperature and species profile. Three specific cases were computed: (1) laminar flame propagation, (2) turbulent flame of five per cent intensity, and (3) turbulent flame of eight per cent intensity. The dimensionless integral scale of turbulence was assumed to be 0·85 and 0·64 respectively, for cases (2) and (3). In all cases a stoichiometric methane-air mixture was assumed. The results of the study can be summarized by the following equation: UT/UL = c + d(u′/UL)(Ly/b) where UT and UL are the turbulent and laminar flame propagation, respectively: c and d are constants depending upon the fuel, fuel air ratio and fluid flow conditions: u′ is the root-mean-square value of the fluctuating velocity; Ly is the integral scale of turbulence; and b is a characteristic length. It can be shown that turbulent flame propagation increases with an increase in intensity of turbulence u′ if the scale of turbulence, Ly laminar flame propagation, and fuel/air ratio are held constant. Also, turbulent flame propagation increases with a decrease in scale of turbulence Ly if the intensity of turbulence u′, laminar flame propagation, and fuel/air ratio are held constant. The theoretical and experimental data are in close agreement.
Serial changes in left and right ventricular systolic and diastolic dynamics during the first year after an index left ventricular Q wave myocardial infarction.

Objectives. This study quantified serially biventricular emptying and filling after infarction and related these to changes in volume, muscle mass, wall stress and contractility. Background. There are limited data on serial changes in ventricular dynamics after infarction. Methods. Forty patients had serial electron beam computed tomographic examinations during the first year after index Q wave infarction (21 anterior, 19 inferior), and global biventricular volumes, peak rates of emptying and filling and left ventricular muscle masses were quantified. Mean mid-left ventricular end-systolic wall stresses, rate-corrected velocities of circumferential shortening and two indexes of left ventricular contractility—the end-systolic wall stress/volume ratio and the end-systolic wall stress/rate-corrected velocity of circumferential shortening relation—were estimated in each instance. Results. Patients with anterior infarction had an increase in biventricular chamber volume of 15% to 35% by 1 year. Global biventricular peak rates of emptying and filling were decreased by 20% to 30% from hospital discharge to 6 weeks but thereafter remained unchanged. Despite a significant increase in mean wall stresses, the end-systolic wall stress/volume ratio remained unchanged during the year. The rate-corrected velocities of circumferential shortening declined serially after anterior infarction but did so in proportion to the increase in mean wall stresses, consistent with no net change in left ventricular contractility. Patients with inferior infarction showed a trend toward similar changes, but the magnitudes did not reach significance. Conclusions. Left (and right) ventricular global peak rates of emptying and filling during the first year after infarction can be altered in the absence of additional ischemic injury but are more consistent with responses to changes in left ventricular afterload than changes in intrinsic ventricular performance or contractility. Serial changes in left ventricular afterload after infarction are largely due to progressive chamber enlargement and limited development of compensatory hypertrophy during the first year. Intrinsic global left ventricular contractile performance was not altered by postinfarction cardiac remodeling in the patients examined.
1001 Greater degree of left ventricular scar is associated with increased mortality in patients with severe ischemic cardiomyopathy

Methods 349 patients with severe ICM >/= 70% coronary artery disease in >/= 1 epicardial vessel on angiography, mean LV ejection fraction (EF) of 24%] that underwent DHE-MRI (Siemens 1.5 T scanner, Erlangen, Germany) from 2003– 6 were studied. (Siemens, Erlangen, Germany) from 2005–6. DHE-MR images were obtained in standard long and short axis orientations (covering the entire LV), after injection of Gadolinium dimenglumine using an inversion recovery spoiled gradient echo sequence: TE 4 msec, TR 8 msec, flip angle 300, bandwidth 140 Hz/pixel, 23 kspace lines acquired every other RR-interval, field of view (varied from 228–330 in the x-direction and 260–330 in the y-direction) and matrix size (varied from 140–180 in the x-direction and 256 in the y-direction). For DHE-MRI analysis, a custom analysis package (VPT software, Siemens, Erlangen, Germany) was used to manually delineate endocardial and epicardial myocardial edges. Scar was defined (as % of myocardium in a 17-segment model on custom software, Siemens Research) on DHE-MR images, as intensity > 2 standard deviation above viable myocardium. Transmurality score was recorded in all segments as follows: 0 = no scar, 1 = 1–25% scar, 2 = 26–50%, 3 = 51– 75% and 4 = > 75%. Total scar score was calculated as transmurality score for all segments/17. LV volumes, EF, demographics, risk factors, need for cardiac transplantation (CTx) and all-cause mortality were recorded. Figure 1.
Lipolysis and cyclic AMP accumulation in isolated fat cells from chicks.

Abstract The effects of glucagon on lipolysis and cyclic AMP accumulation were studied in isolated chick adipocytes. Lipolysis increased at concentrations of glucagon as low as 100 ng/ml, but detectable elevations in cyclic AMP were not seen at this concentration of glucagon. Higher concentrations of glucagon (250 ng/ml) elevated cyclic AMP to high levels as early as 1 min after its addition, and these increases were maintained for at least an hour of incubation. N 6 (phenylisopropyl)adenosine inhibited glucagon-stimulated increases in cyclic AMP, but it inhibited lipolysis weakly and only in the absence of theophylline. Adenosine deaminase had no apparent effect on lipolysis or cyclic AMP accumulation. The results suggest that while cyclic AMP is involved in the regulation of chick adipocyte lipolysis, there is no simple relationship between total cyclic AMP content and lipolysis.
Temperature-dependent water structure: Ab initio and empirical model predictions

Structural correlations in liquid water are systematically examined using increasingly realistic theoretical models, including empirical rigid, empirical polarizable, empirical flexible with classical and quantum nuclei, and ab initio with classical nuclei at 300 and 353 K and quantum nuclei at 300 K. All models predict a significantly greater percentage of water molecules accepting two hydrogen bonds and a weaker temperature dependence of the hydrogen-bond angle than recent experimental reports suggest.
Animal Abuse in Childhood and Later Support for Interpersonal Violence in Families

A survey of university students tested whether committing animal abuse during childhood was related to approval of interpersonal violence against children and women in families. Respondents who had abused an animal as children or adolescents were significantly more likely to support corporal punishment, even after controlling for frequency of childhood spanking, race, biblical literalism, and gender. Those who had perpetrated animal abuse were also more likely to approve of a husband slapping his wife. Engaging in childhood violence against less powerful beings — animals — may generalize to the acceptance of violence against less powerful members of families and society — women and children. This paper discusses the implications of this process.
Language functioning and speech development of six children receiving tracheotomy in infancy

Language functioning and speech development were assessed in six preschool boys who had undergone tracheotomy during infancy and had tracheal tubes in place for varying periods of time (from 11 to 44 mo). Results indicated that neonatal tracheotomy did not produce long-term effects on language development. Children with subnormal intelligence showed aberrant language functioning, characteristic of language-disordered children who had not had tracheotomies. Children with average intelligence exhibited grossly normal expressive language and verbal comprehension. All children learned to produce some verbalizations, if only through pops, lip movements, and breath sounds; or through esophageal speech. One child who did not vocalize until his cannula was removed at 21 mo was able to develop age-appropriate expressive language, despite lack of previous opportunity to produce speech sounds.
Heating curves of solids obtained by a solar furnace

Abstract By the use of a heliostat type solar furnace, materials having high melting points can be fused and their freezing points measured with the brightness pyrometer by the specular reflection method in the previous paper. ∗ The heating curves of a specimen are measured with the brightness pyrometer in the same way, and the melting point of the solid fused with a solar furnace is obtained. The time required to fuse the specimen as a function of irradiance is also calculated from the curve. Experimental data on ZrO2 and Y2O3 are presented.
Daily functioning and quality of life in children with sickle cell disease pain: relationship with family and neighborhood socioeconomic distress.

Abstract The aim of this study was to examine the relationship between individual/family and neighborhood socioeconomic distress, pain, and functional outcomes in children with sickle cell disease (SCD). We hypothesized that both individual economic distress as well as residence in neighborhoods of severe economic distress would predict children's level of pain-related functional disability and health-related quality of life (HRQOL). Participants (mean age, 12.14 years; 57% male, n = 56) were recruited from an outpatient hematology clinic at a Midwestern tertiary referral hospital. Questionnaires assessing pain, depression, functional disability, and HRQOL were completed by children and their caregivers. Individual socioeconomic data including parental education and family income were reported by caregivers. Neighborhood socioeconomic distress was identified using publicly available census tract data and was based on neighborhood poverty, female head of household, male unemployment, and high school dropout levels. Multivariate regression analyses revealed that individual/family socioeconomic distress was a significant predictor of children's functional disability and physical and psychosocial HRQOL. Neighborhood socioeconomic distress emerged as a significant independent predictor of physical HRQOL only, where living in a distressed neighborhood predicted diminished physical HRQOL. Findings suggest that individual socioeconomic status and neighborhood economic distress play similar but independent roles in predicting children's functional outcomes related to SCD pain. Perspective Little is known about the influence of either individual/family or neighborhood socioeconomic factors on pain and functioning in children with SCD. Our findings suggest that socioeconomic distress defined at both the individual level and at the neighborhood/community level are significant independent predictors of pain-related disability and HRQOL in children with SCD.
Modeling the gas flux from a Jupiter-family comet nucleus

Abstract Mixing ratios of sublimating gases from ices in porous bodies in the solar system are important, observable phenomena. Surface erosion and dust build-up on a comet nucleus and coma formation are processes attributable to the flux of sublimating gases. Our computer simulations focus on the gas flux from volatile, icy components in the surface layer of a porous, Jupiter-family comet in order to relate quantitatively the observed relative molecular abundances in the coma with those in the nucleus. We assume a porous body containing dust and up to four components of chemically different ices (e.g. H2O, CO, CO2, CH4) and solve the mass and energy equations for the different volatiles simultaneously. The model includes inflowing and outflowing gas within the body, dust mantle build-up, depletion of the most volatile ices in outer layers, and recondensation of gases in deeper layers. The model calculations start with a homogeneously mixed body at a constant temperature and a constant mass density at aphelion of an orbit. Due to insolation and conduction the internal heat of the body increases, and as a result of sublimation of the minor, more volatile components, the initially homogeneous body differentiates into a multi-layered body. For example a dust, H2O, CO2, and CO ice body differentiates into a four-layer body in which the deepest layer has the original composition and the higher layers are successively more depleted of volatiles. The boundaries between the layers are sublimation fronts of the corresponding volatile phases. The depths of the sublimation fronts change with time and are on the order of tens of meters. From the calculations we obtain temperature, relative chemical abundance, porosity, and pore size distributions as a function of depth, and the gas flux into the interior and into the coma for each of the volatiles at various positions of the comet in its orbit. In this paper we explore some early steps on the way to a more comprehensive model for comet nuclei. In order to understand the consequences of processes better we have made some simplifying assumptions. To investigate the effects of dust, we have modeled the nucleus with and without dust. We find that a dust layer at the surface of the nucleus drastically reduces the sublimation flux of H2O at heliocentric distances, r
Ozone, acidic precipitation, and soil Mg effects on growth and nutrition of loblolly pine seedlings

Abstract Height, diameter, biomass, and nutrient concentration and content were determined for loblolly pine (Pinus taeda L.) seedlings growth at two levels of soil Mg and exposed to chronic levels of O3 and simulated acidic precipitation. Nutrient contents in precipitation and throughfall were also determined. Seedlings were planted in a sandy loam soil (Lilly series) having approximately 15 or 35 mg/kg Mg and were exposed to subambient, ambient, or twice ambient concentrations of O3 in open-top chambers from May through to October of 1987 and April through to October of 1988. Seedlings also received simulated rainfall at pH 3.8 or 5.2 in volumes equivalent to ambient rainfall. After two growing seasons, height and diameter were significantly greater for seedlings exposed to subambient and twice ambient O3 than for seedlings exposed to ambient O3. Biomass of all seedling components was progressively reduced with increasing O3 concentrations. Net throughfall nutrient contents and foliar nutrient contents were not significantly affected by precipitation pH treatments, indicating that foliar leaching was not accelerated by increasing the acidity of precipitation from pH 5.2 to 3.8. Throughfall and foliar nutrient contents were not significantly affected by O3 treatments, and no significant O3 × precipitation pH interactions occurred, indicating that after two growing seasons O3 did not act to exacerbate foliar leaching. Seedlings grown in soil having 15 mg/kg Mg exhibited significantly reduced Mg concentrations and contents in all comonents, but seedling growth was not significantly affected by this treatment.
Flexible Manufacturing Organizations: Implications for Strategy Formulation and Organization Design

Recently developed flexible manufacturing technologies (FMT) offer managers new strategic opportunities. After summarizing the literature on organization level technology and manufacturing strategy, FMT organization is described and compared to mass production organization on several key dimensions. Propositions are offered to guide future research and management practice.
A giant omphalocele in a preterm infant: the conservative approach

A routine antenatal ultrasound scan in the first trimester revealed a large omphalocele mainly occupied by liver in a female infant. Owing to preterm labour she was delivered by caesarean section at 29+4 weeks of gestation with a birth weight of 1450 g. No other malformations were present and her karyotype was normal. The neonatal period was complicated by severe respiratory distress with pulmonary hypertension requiring prolonged high-frequency ventilation and inhaled nitric oxide. The infant developed bilateral grade 2 intraventricular haemorrhages. A haemodynamically significant ductus arteriosus was closed surgically. Owing to these complications, primary closure of the 4×4 cm large omphalocele (figure 1) was initially not feasible. Palliative care was considered, but was not …
Origin of the disturbed magnetic zone between the Murray and Molokai fracture zones

Abstract Two different hypotheses have been advanced to explain the disturbed magnetic zone between the Murray and Molokai fracture zones, and the change in offset of the magnetic anomalies across the eastern and western portions of the Murray fracture zone. The first calls for an abrupt jump of the spreading center 530 km eastwards at 51 mybp (between anomaly 21 and anomaly 20). The second calls for a secondary spreading center starting just to the west of the primary center and moving away from it. The secondary center was active between 38 mybp (anomaly 15) and 27 mybp (anomaly 7). A third hypothesis, advanced in this paper, is that the ridge crest jumped eastwards 530 km, as in the first hypothesis, but at a much later time, 40 mybp. The postulated ages of the various portions of the sea floor between the Murray and Molokai fracture zones are radically different for the three models. An empirical relationship has been shown to exist between elevation and age of oceanic crust. Topographic profiles based on this relationship are compared with the observed bathymetry between the two fracture zones. The second and third hypotheses fit the observed topography much better than the first. If the second hypothesis is correct, the Murray and Molokai fracture zones were active across the whole of the western Pacific between 50 mybp and 27 mybp, with sense of motion on the fracture zones changing direction at 38 mybp. The third hypothesis does not involve such long active transform faults but rather explains the offset of the magnetic lineations by a minor reorganization of the ridge crest. As it is simpler and also because JOIDES site 172 at 31°32.2′N and 133°22.4′W gave a possibly early Oligocene age for the oldest sediments the third model is preferred. None of the three hypotheses match the observed magnetic anomaly patterns convincingly and more profiles west of 135°W are needed before the second and third hypotheses can be distinguished.
First results from CLEO-c

I present the first results from the CLEO-c experiment which has completed an initial run at charm threshold.
Simultaneous generation of multiple aqueous droplets in a microfluidic device

This paper describes a microfluidic platform for the on-demand generation of multiple aqueous droplets, with varying chemical contents or chemical concentrations, for use in droplet based experiments. This generation technique was developed as a complement to existing techniques of continuous-flow (streaming) and discrete-droplet generation by enabling the formation of multiple discrete droplets simultaneously. Here sets of droplets with varying chemical contents can be generated without running the risk of cross-contamination due to the isolated nature of each supply inlet. The use of pressure pulses to generate droplets in parallel is described, and the effect of droplet size is examined in the context of flow rates and surfactant concentrations. To illustrate this technique, an array of different dye-containing droplets was generated, as well as a set of droplets that displayed a concentration gradient of a fluorescent dye.
A Critical Primer on Postmodernism: Lessons from Educational Scholarship for Librarianship

Abstract Postmodernism is still the subject of vigorous ongoing debate in a variety of fields like education and anthropology and has now arrived in the literature of librarianship. Prior conflicts generated over postmodernism remain—including academic areas where it has been declared passe. This paper summarizes postmodernism and its intellectual contributions, and then highlights its shortcomings via critical educational scholarship utilizing that field as a framework of analysis for librarianship. This is undertaken to relate both strengths of and problems with postmodernist theories for current work among scholars in librarianship. We do so to learn from the course of debate in another field and to challenge postmodern research trends in librarianship that do not account for the cultural and economic effects of capitalism.
Excimer Laser-Assisted Deposition And Etching Of II-VI Materials

Results on laser-assisted deposition and surface modification of II-VI semiconductors and real-time optical diagnostics of laser-assisted reactions are reported. Excimer laser-assisted metal-organic vapor phase epitaxy has been used to deposit epitaxial layers of CdTe on GaAs(100) and HgTe and [HgCd]Te layers on CdTe/GaAs(100) at 165°C. KrF excimer laser radiation (248 nm) was used to photodissociate divinylmercury, dimethylcadmium and diethyltellurium source materials in the gas phase in a substrate-parallel irradiation geometry. Laser-induced fluorescence and multi-photon ionization spectroscopy was used to probe Te alkyl photodissociation dynamics. Single photon excitation at 248 nm results in the formation of ground state (5p3P2) Te atoms and alkyl photofragments. These results are consistent with a mechanism in which 248 nm excitation results in destabilization and cleavage of both Te-C bonds in the metal alkyl. Controllable surface layer removal and reproducible fluence-dependent composition changes were produced in CdTe thin films by KrF excimer laser irradiation. Time-of-flight mass spectrometric measurements of the velocity distribution of photoejected species are consistent with a thermal mechanism for the laser ablation process.
A relative-flux-correction scheme for analyzing three dimensional data of a tile-drained agricultural plot

Abstract The use of simple geostatistical tools is often constrained by data trend (nonstationarity) to characterize the spatial variability of soil properties in the subsurface environment influenced by any site-specific feature(s). Adaptive approaches, such as site-specific robust-resistant schemes, median polishing, trend analysis, etc., are thus used to preprocess the spatial data before analyzing for their spatial structures. Soil water nitrate–nitrogen (NO 3 –N) concentration (mg l −1 ) and soil moisture content (cm) data collected jointly from 175 sites arranged on a 5×7×5 three-dimensional (3-D) grid network of 7.6 m×7.6 m×0.3 m spacings in a tile-drained agricultural plot were analyzed for their three-dimensional spatial distribution and for possible coregionalization. We propose a physical process-based correction scheme to preprocess the nonstationary spatial data of soil NO 3 –N concentration and soil moisture content. Using the subsurface-drain flow phenomenon, we developed a relative-Darcy-flux-based correction scheme to remove any tile drainage-induced nonstationarity in the spatial data of soil NO 3 –N concentration and soil moisture content prior to conducting the spatial analysis in the 3-D soil volume. 3-D composite semivariograms of relative-flux-corrected NO 3 –N concentration and relative-flux-corrected moisture content showed anisotropic linear structures in three principal directions. Linear models characterized by steep slopes were found in the directions perpendicular to tile line as opposed to nugget models found in the direction parallel to the tile line. Good spatial correlation between the relative-flux-corrected NO 3 –N concentration and relative-flux-corrected soil moisture content and their anisotropic linear semivariograms produced anisotropic linear cross semivariograms in 3-D. The 3-D composite cross semivariogram will be useful in predicting the more expensive variable, (relative-flux-corrected) soil water NO 3 –N concentration, at unsampled locations in the soil profile with a cheaper surrogate, the measured (relative-flux-corrected) soil moisture content.
A Light Scattering Study of the Interaction of Fibroblast Growth Factor (FGF) with its Receptor

Light scattering technique has been used to study the interaction between fibroblast growth factor (FGF) and its receptor. In this study, a general mathematical model has been developed where the concentration of product formed by the interaction of two proteins and its dependence on the initial concentration of interacting proteins have been determined using laser light scattering. Calculated hydrodynamic diameters reveal that both human fibroblast growth factor (hFGF-1) and its receptor domain (D2 domain) exist as monomers in solution. Titration of hFGF-1 and the D2 domain of FGFR show that they interact in a 1:1 stoichiometry in solution. The binding stoichiometry does not depend on the concentrations of the interacting proteins. The results of this study, for the first time to our knowledge, provide an unambiguous evidence that the 2:2 binary complex of FGF and FGFR observed in the crystal structures of the FGF-FGFR complex (in the absence of heparin) is possibly a crystallization artifact.
Maternal interaction and language development in children with and without speech-related anomalies.

Abstract This study explores relationships among maternal behavior, child language, and location of congenital structural anomaly in three groups of 24-month-old children: 21 with speech- related anomalies (SRA), 13 with non-speech-related anomalies (NSRA), and 45 normal controls. In addition to standardized assessment of intelligence and language, children and mothers were observed in a half-hour videotaped play session, later coded for maternal and child interactive behavior. SRA children showed significantly poorer performance than controls on standardized tests. Mothers of SRA children showed significantly more Physical Teaching and Initiating relative to controls. Mothers of both SRA and NSRA children used significantly more Attention Management than did controls. The patterns of poorer child performance and maternal interactive compensations is largely confined to children whose structural disabilities are speech-related. Maternal interactive behavior is not global in its response to child disability; rather, it varies with the particular pattern of child disabilities found.
The best tax strategies for M&A

Companies are taking a new look at the best tax strategies for M&A because a proposed FASB rule could make mergers a lot more expensive. © 2000 John Wiley & Sons, Inc.
A method of aligning peak lists generated by gas chromatography high-resolution mass spectrometry

We report a method for the peak list alignment of gas chromatography high resolution time-of-flight mass spectrometry data. The alignment is performed in a z-score transformed retention time domain to standardize chromatographic peak distribution across samples. A mixture score is developed to assess the similarity between two peaks by simultaneously evaluating the mass spectral similarity and the closeness of retention time. An analysis of experimental data acquired under three different flow rates indicates that the proposed method is able to correctly align the heterogeneous data. The effectiveness of method is further validated by analyzing experimental data of multiple mixtures of metabolite extract from mouse liver with 28 spiked-in acids. All of the detected spiked-in acids were correctly aligned. A statistical test correctly detected the concentration differences of the spiked-in compounds between sample groups using the alignment table. The area under curve (AUC) value in the receiver operating characteristic (ROC) curve is larger than 0.85 in all three of the compared sample groups, indicating a high accuracy of peak alignment and supporting the potential application of the proposed method for metabolomics projects such as biomarker discovery.
Laser induced fluorescence measurements of radical concentrations in hydrogen–hydrocarbon hybrid gas fuel flames

Abstract Laser Induced Fluorescence (LIF) measurements of OH, CH and CN radical concentrations in hydrogen–natural gas hybrid fuel diffusion flames at Re=150 are presented. Radial concentration profiles of these radicals in the near-burner region (7 mm above the burner) for different mixtures of hydrogen–natural gas are reported. The OH radical concentration profile shows a peak on the stoichiometric contour for all three mixtures (100%, 80–20% and 65–35% by volume of hydrogen–natural gas). The OH radical concentration decreases with the increase of natural gas content in the mixture. The peaks of relative CH radical concentration-profiles do not coincide with the temperature maxima, but appear on the fuel side of the stoichiometric contour. As expected, CH concentration also increases with the increase of natural gas concentration in the mixture. The CN radical concentration profile has a peak close to the flame edge on the air side of the stoichiometric contour. Similar to the CH radical, CN radical concentration also increases with the increase of natural gas content in the hybrid fuel.
Effects of H2-receptor antagonists on gastric alcohol dehydrogenase activity

Inhibition of gastric alcohol dehydrogenase (ADH) activity by cimetidine results in elevated blood levels of ethanol after moderate consumption. To search for alternative H2-blockers lacking such an effect, we compared cimetidine, ranitidine, nizatidine, and famotidine. They inhibited rat gastric ADH noncompetitively, with aKi for ethanol oxidation of 0.68 mM for cimetidine, 0.5 mM for ranitidine, 1 mM for nizatidine, and 4.5 mM for famotidine. These concentrations are higher than therapeutic plasma levels, but intracellular concentrations in the gastric mucosa (assessed with [3H] cimetidine and [14C]famotidine) were at least 10- and 2-fold greater than in the blood, respectively. These results suggests that, given at therapeutic dosesin vivo, the degree of inhibition by cimetidine and ranitidine should be significant and comparable, that by nizatidine should be smaller, and that by famotidine should be negligible. These drugs also exerted either mixed or competitive inhibition of rat hepatic ADH, but the effects of cimetidine and famotidine were observed at concentrations unlikely to occurin vivo. Thus, in alcoholics and in social drinkers who require treatment with H2-receptor antagonists, famotidine might be preferable to the other H2 blockers tested.
Supercritical fluid extraction of selected pesticides from fortified soils and determination by gas chromatography with electron capture detection

Abstract Supercritical carbon dioxide mixed with 3% methanol was used to extract real‐world soil samples fortified with 12 selected organophosphate and organochlorine pesticides. Comparison of replicate supercritical fluid extractions (N=3) to classical sonication extractions (N=3) showed equivalent recoveries of the pesticides from four soil samples. The precisions for sonication extraction and SFE were also demonstrated to be identical.
Modulating atherosclerosis through inhibition or blockade of angiotensin.

Angiotensin-converting enzyme (ACE) inhibitors are well recognized for their benefits in treating hypertension and congestive heart failure and preventing postmyocardial infarction heart failure or left ventricular (LV) dysfunction. Recently, blockade of the angiotensin II type I (AT 1 ) receptor was shown to reduce cardiovascular events in hypertensive subjects with LV hypertrophy. Several lines of evidence are now converging to show that ACE inhibitors may affect the atherosclerotic process itself. Emerging clinical data indicate that angiotensin-receptor blockers (ARBs) may possibly modulate atherosclerosis as well. The antiatherogenic properties of ACE inhibitors and ARBs may derive from inhibition or blockade of angiotensin II, now recognized as an agent that increases oxidative stress. Angiotensin-converting enzyme inhibition and angiotensin-receptor blockade also increase endothelial nitric oxide formation, which improves endothelial function. In contrast to the effects of ARBs, the vascular effects of ACE inhibitors may, in part, be mediated by an increase in bradykinin. This article reviews some of the biologic mechanisms whereby ACE inhibitors and ARBs may modulate atherosclerosis.
Variations in development of the caudal neural tube in human embryos (Horizons XIV-XXI).

Eight human embryos of Streeter's Horizons XIV to XXI were examined with respect to variations in caudal neural tube development after closure of the posterior neuropore in Horizon XII. A major aspect of this development appears to be a process of “canalization” (accessory lumens coalescing from the differentiating caudal neural cell mass), which corresponds to such occurrences in the chick and rat. Some degree of obliteration of the central canal was found in four embryos. The relation of these observations to clinical entities is discussed. There is suggestive evidence that open lesions of the spine may be associated with failure of closure of the posterior neuropore. In contrast, normal-skin covered lesions probably arise from neural tube formed from the differentiating caudal cell mass after Horizon XII. This hypothesis could explain the distribution of lesions seen in newborn children.
The type 1 interleukin‐1 receptor is essential for multiple aspects of brain inflammation

Interleukin-1 (IL-1) is induced immediately after brain imjury and elevated levels of IL-1 have been strongly implicated in the neurodegeneration that accompanies stroke, Alzheimer's disease and Multiple Sclerosis. Antagonizing IL-1 reduces cell death; however, the basis for this protection has not been elucidated. Here we analyzed the response to penetrating brain injury in mice lacking the type 1 interleukin receptor (IL-1R1) to determine which cellular and molecular mediators of tissue damage require IL-1 signaling. At the cellular level fewer amoeboid microglia/macrophages appeared adjacent to the injured brain tissue in IL-1R1 null mice, and those microglia present at early postinjury intervals retained their resting morphology. Astrogliosis also was mildly abrogated. At the molecular level, cyclooxygenase 2 and IL-6 expression were depressed and delayed. Interestingly, basal levels of cyclooxygenase 2, IL-1 and IL-6 were significantly lower in the IL-1R1 null mice. Additionally, stimulation of VCAM-1 mRNA was depressed in the IL-1R1 null mice, and correspondingly, there was reduced migration of peripheral macrophages into the IL-1R1 null brain after injury. This observation correlated with a reduced number of cyclooxygenase 2+ amoeboid phagocytes adjacent to the injury. By contrast, the production of nerve growth factor was only mildly affected. Since antagonizing IL-1 protects neural cells in experimental models of stroke and multiple sclerosis, our data suggest that cell preservation is achieved by abrogating microglial/macrophage activation and the subsequent self-propagating cycle of inflammation. Acknowledgements: Supported by NMSS Award #RG 3837.
Factors predicting the ocular surface response to desiccating environmental stress.

Purpose. To identify factors predicting the ocular surface response to experimental desiccating stress.