cssi/SciSciGPT-SciSciNet huggingface dataset:
129 CARDIAC OUTPUT CHANGES SECONDARY TO THEOPHYLLINE THERAPY IN PRETERM INFANTS

The action of theophylline on the neonatal heart was studied in 11 clinically stable preterm infants. Mean (±SE) birth weight was 1230±390 g and the gestational age 30.7±2.8 wks. Median postnatal age was 12 days. Indications for theophylline therapy were BPD in 3, extubation in 7, and apnea in 1 neonate. Theophylline was given as IV aminophylline using a loading dose of 6.8 mg/kg and a maintenance dose of 2 mg/kg q 8 h. Cardiac output, stroke volume; and heart rate were measured using a combination of pulsed Doppler ultrasound and M-mode echocardiography before the start, on days 1, 2, 3 and 7, and after discontinuation of the drug. Arterial blood pressure was obtained by Dinamap. An increase in cardiac output (p<0.01) was found on days 1, 2, 3, and 7. Stroke volume was significantly higher (p<0.02) on days 1, 2, 3, but comparable to pretreatment values by day 7. Heart rate was augmented significantly (p<0.01) throughout the treatment period. Mean arterial blood pressure did not change. All but one of the neonates had theophylline levels between 6 and 13 mg/1. We conclude that during the first days of theophylline therapy both inotropic and chronotropic effects prevail. At 7 days the inotropic effect has disappeared, whereas the chronotropic effect persists. The metabolic cost of the increased cardiac output during theophylline therapy in the preterm infant deserves further attention.
A model current system for the magnetospheric substorm

A model three dimensional current system for the magnetospheric substorm is proposed to account for the distribution of geomagnetic disturbance field vectors on the earth’s surface and for the distribution of auroral electrons and protons at the ionospheric level and in the equatorial plane. It is suggested that the asymmetric ring current completes its circuit by accelerating auroral particles and by driving the auroral electrojet.
Patterns and predictors of short-term death after emergency department discharge.

Study objective The emergency department (ED) is an inherently high-risk setting. Early death after an ED evaluation is a rare and devastating outcome; understanding it can potentially help improve patient care and outcomes. Using administrative data from an integrated health system, we describe characteristics and predictors of patients who experienced 7-day death after ED discharge. Methods Administrative data from 12 hospitals were used to identify death after discharge in adults aged 18 year or older within 7 days of ED presentation from January 1, 2007, to December 31, 2008. Patients who were nonmembers of the health system, in hospice care, or treated at out-of-network EDs were excluded. Predictors of 7-day postdischarge death were identified with multivariable logistic regression. Results The study cohort contained a total of 475,829 members, with 728,312 discharges from Kaiser Permanente Southern California EDs in 2007 and 2008. Death within 7 days of discharge occurred in 357 cases (0.05%). Increasing age, male sex, and number of preexisting comorbidities were associated with increased risk of death. The top 3 primary discharge diagnoses predictive of 7-day death after discharge included noninfectious lung disease (odds ratio [OR] 7.1; 95% confidence interval [CI] 2.9 to 17.4), renal disease (OR 5.6; 95% CI 2.2 to 14.2), and ischemic heart disease (OR 3.8; 95% CI 1.0 to 13.6). Conclusion Our study suggests that 50 in 100,000 patients in the United States die within 7 days of discharge from an ED. To our knowledge, our study is the first to identify potentially "high-risk" discharge diagnoses in patients who experience a short-term death after discharge.
Stress resistance and aging: Influence of genes and nutrition

Previous studies have shown that dermal fibroblast cell lines derived from young adult mice of the long-lived Snell dwarf (dw/dw), Ames dwarf (df/df) and growth hormone receptor knockout (GHR-KO) mouse stocks are resistant, in vitro, to the cytotoxic effects of hydrogen peroxide, cadmium, ultraviolet light, paraquat, and heat. Here we show that, in contrast, fibroblasts from mice on low-calorie (CR) or low methionine (Meth-R) diets are not stress resistant in culture, despite the longevity induced by both dietary regimes. A second approach, involving induction of liver cell death in live animals using acetaminophen (APAP), documented hepatotoxin resistance in the CR and Meth-R mice, but dw/dw and GHR-KO mutant mice were not resistant to this agent, and were in fact more susceptible than littermate controls to the toxic effects of APAP. These data thus suggest that while resistance to stress is a common characteristic of experimental life span extension in mice, the cell types showing resistance may differ among the various models of delayed or decelerated aging.
Colocalization of D1 and D2 dopamine receptor mRNAs in striatal neurons

There is evidence that D1 and D2 dopamine receptor subtypes coexist at the cellular level in the striatum and act synergistically to mediate the effects of dopamine. Other data suggest that these receptor subtypes are largely segregated in different striatal projection pathways. We used in situ hybridization in serial adjacent 4 microns sections to determine the extent of colocalization of D1 and D2 receptor mRNAs in rat striatal neurons. Cellular localization of D1 and D2 receptor mRNA was performed on section pairs that were hybridized with 35S-labeled cDNA or oligonucleotide probes directed against non-homologous regions of D1 and D2 receptor mRNAs. We found that 26-27% of striatal cells containing one receptor subtype also contained the other subtype. Thus, although D1 and D2 receptors are segregated in the majority of striatal neurons, a substantial number of striatal neurons coexpress both dopamine receptor mRNA subtypes. Our findings provide anatomic support for many of the functional interactions that have been described for D1 and D2 receptors.
Fiber optic components and systems at Oregon State University

Research efforts in our department include work on novel GaAs/AlGaAs laser structures and photodetectors which could be used in fiber optic sensor applications. Brief descriptions are given of three such components: a HEMT- compatible, very low threshold diode laser; a high-gain traveling-wave amplifier or high-power, broad linewidth LED; and a MODFET photoconductor. A senior/graduate level course is also taught on guided wave optics. In this lecture/laboratory course, students do design projects on either fiber optic sensors or fiber communication systems. Two examples of student fiber sensor projects will be given: a pressure sensor and an interferometric temperature sensor.
Dynamic fracture of a tapered idealized fiber-reinforced cantilever

Abstract A kinematically simple model for dynamic fracture of a tapered fiber-reinforced double cantilever beam is discussed. The model requires the solution of the wave equation with a variable coefficient on a time-dependent domain. The case of parabolic tapering is treated in closed form, for a time interval after fracture begins from a pre-existing crack. The crack speed is found under two fracture criteria; the first of these is the usual energy criterion while the second is based on the fact that certain fibers in the model can carry concentrated forces.
Cuba’s “Yes, I Can” mass adult literacy campaign model in Timor-Leste and Aboriginal Australia: A comparative study

In the field of international adult education, mass literacy campaigns enjoyed wide support in the 20th century, when they were seen as a way to increase the participation of previously marginalised and excluded populations in national development. Cuba’s 1961 campaign achieved iconic status, but was only one of many successful campaigns in Latin America, Africa and Asia. In the 1990s, while mass literacy campaigns continued in many countries, scholarly interest in them declined under the influence of World Bank empirical critiques of their effectiveness and increasing postmodern scepticism towards the socialist “grand narrative” of liberation which underpinned some of the more famous examples. Recently, the mass campaign model has gained new impetus through Cuba’s international literacy missions, which use an approach known by its Spanish name, Yo, Si Puedo [Yes, I Can]. This paper reports on the deployment of this model in two very different settings, one being a national literacy campaign in Timor-Leste, a newly-independent island nation in the Asia–Pacific; and the other a pilot campaign in an Aboriginal community in Australia. The authors have utilised participatory action research methods to evaluate the model in both countries, and locate their comparative analysis in the theoretical tradition of popular education.
Theoretical study of the regioselectivity of the cycloaddition reaction between cyclopentadiene and methyleneketene

Three possible reaction schemes for the cycloaddition reaction between methyleneketene and cyclopentadiene were studied by DFT (density functional theory) and ab initio calculations. All of these cycloaddition reactions are exothermic, concerted but nonsynchronous processes. The computed activation energies indicate that the norbornene product yielded from a 1,2-addition of methyleneketene with cyclopentadiene (reaction (1)) is the primary product. The performance of various computational methodologies, MP2, MP4, and CCSD(T), in conjunction with a wide array of basis sets, 6-31G(d), 6-311+G(d,p), aug-cc-pVDZ, and aug-cc-pVTZ, in obtaining reliable activation and reaction energies of the reactions under investigation has been critically analyzed.
Emergence of division of labour in halictine bees: contributions of social interactions and behavioural variance

A central question in the study of insect societies concerns the emergence of division of labour. Among the different models of division of labour, the threshold model postulates that it can emerge from initial interindividual differences in the propensity to perform a task. The requirements of this variance-based model are likely to be present at the origins of sociality and may thus contribute to the emergence of division of labour in early social evolution. However, social interactions among members of the incipient groups are also likely to shape the genesis of division of labour. In this study, we compared task performance and social interactions during nest construction in forced associations of the solitary halictine bee, Lasioglossum (Ctenonomia) NDA-1, and of the communal Lasioglossum (Chilalictus) hemichalceum. We recorded and compared individual behaviours during nest construction for pairs of solitary or communal bees. These data were compared, in turn, to the excavation behaviours of the same bees while alone to determine how the presence of a social group influenced task performance. We additionally measured social interactions of pairs outside the context of nest construction. Pairs of solitary bees displayed higher levels of division of labour than communal pairs. A numerical model implementing behavioural rules derived from experiments suggests that in communal bees, division of labour can be primarily explained by differences in task propensity. In solitary bees, both behavioural asymmetry and social interactions contribute significantly to division of labour. These results are discussed in the framework of social transitions in halictine bees.
The Effects of Language Laboratory Type Upon Cultural Orientation Scores of Foreign Language Students

I N THE search for better understanding of the processes involved in the learning and teaching of foreign languages, we recognize the relevance of the field of psycholinguistics. A considerable amount of research effort has been directed toward this area.' The Associated Colleges of the Midwest (ACM)2 conducted a program of research in the field of foreign language instruction at the college level. The research program was undertaken to examine and test various proposals for improvement which would provide assistance to the individual colleges in their search for ways to strengthen foreign language courses. The research of this program took place in what we might call a "field" setting. By a field setting we mean the actual educational situation in foreign language instruction as it existed in the colleges. The situation for this research was relatively broad since it cut across the ten colleges. Not all colleges participated in all experiments, but every college was involved in at least one. This then was not a maximumly controlled experiment as in the study by Scherer and Wertheimer.' The writers recognize that several uncontrolled factors, such as the teacher, existed in this research. However, because of the broad setting, the results pertain directly to foreign language instruction in colleges similar to those of the ACM. One of the experiments involved the use of two types of language laboratories. These types are described in detail below. The types of laboratories were then examined to ascertain the effects, if any, upon various student measures. Specifically, the problem reported here dealt with effect of type of laboratory upon the cultural orientation scores of the students. The scores of the two laboratory groups were also compared to scores of a pre-college control group. These were beginning freshmen who had not had foreign language instruction at the college level.
Reliability degradation of ultra-thin oxynitride and Al2O3 gate dielectric films owing to heavy-ion irradiation

The charge-to-breakdown of 3.3 nm oxynitride films shows significant degradation after irradiation with 342 MeV An ions. In contrast, 5.4 rim Al/sub 2/O/sub 3/ films exhibit much less degradation for similar heavy-ion stress.
Syncope secondary to ventricular asystole in an endurance athlete

Vasovagal syncope occurred in an endurance athlete prior to exercise as the result of a 22-second episode of complete heart block with ventricular asystole and subsequent sinoatrial arrest. The subject suffered a head injury but recovered without sequelae. Noninvasive cardiac testing was unrevealing. Although lesser disturbances of cardiac rhythm and conduction in athletes are not uncommon, extreme changes as illustrated by this case are rare. Close supervision of athletes undergoing exercise testing is advised.
Using the Absolute Weapon: Early Ideas of Bernard Brodie on Atomic Strategy

(1984). Using the absolute weapon: Early ideas of Bernard Brodie on atomic strategy. Journal of Strategic Studies: Vol. 7, No. 4, pp. 365-393.
The observed fingerprint of 1980–1997 ENSO evolution in the NCAR CSM equilibrium simulation

General circulation models (GCMs) are capable of simulating certain statistical characteristics of the composite El Nino-Southern Oscillation (ENSO) cycle. Here we demonstrate that the NCAR Climate System Model (CSM), in absence of external forcing and data assimilation, simulates both temporal variations and spatial patterns associated with the observed ENSO cycles during 1980s. The model also produces a distinct decadal change of ENSO variations that resembles the observed shift from 1980s (strong and well-defined cycles) to the early 1990s (weak and short-lived warm phases) followed by the strong 1997 El Nino. The study thus suggests that the ENSO evolution during 1980s and the decadal shift in 1990s might be a result of natural variability intrinsic to the interactive climate system. Given the perceived capability to simulate natural variations, the CSM can be used to supplement observational data to better understand climate variability on interannual-to-decadal timescales.
Electrochemical properties of atomic-scale metal wires

We have fabricated atomic-scale metal wires with quantized conductance in electrolytes and studied double layer charging, anionic adsorption and surface stress effects on the quantum transport in the wires. In the double layer charging regime, the conductance changes linearly with the potential, which can be attributed to a change in the amount of electron spill-out of the wire. A large change in the potential results in a substantial stress in the wires, causing atoms in the wires to rearrange. Upon anionic adsorption, the conductance decreases due to the scattering of conduction electrons by the adsorbed anions. # 2003 Elsevier Ltd. All rights reserved.
Practical Considerations for Fixed Wing Helmet-Mounted Display Symbology Design

Abstract : Helmet-mounted displays (HMDs) may become a primary source of head-up information in future tactical aircraft. In evaluations, HMDs have produced improved situation awareness and mission performance. To realize this improved performance, HMD equipped pilots spend significantly more time looking off-axis, away from traditional displays. Accordingly, it is important that HMD information be designed so targeting and ownship status symbology is effective and safe. The U. S. Air Force Research Laboratory is working to develop an optimized HMD symbology set. Toward this end, symbol designs must accommodate the conditions of intended use, technology limitations, and integration with other displays. This paper discusses efforts to design target tracking/location and ownship status symbologies for the day/night all weather fixed-wing tactical aircraft application. Design principles derived from both laboratory and flight test are presented. These principles relate to symbology frame of reference, orientation, compression, and line of sight mechanization. Evaluation methodologies are also discussed.
The effects of retinol on in vitro immunoglobulin synthesis by cord blood and adult peripheral blood mononuclear cells

In this study we examined the effects of retinol (ROH), a metabolic precursor of retinoic acid (RA), on Staphylococcus aureus Cowan I (SAC)-induced immunoglobulin synthesis of cord blood mononuclear cells (CBMC) and adult peripheral blood mononuclear cells (PBMC). ROH augmented SAC-induced IgM synthesis of CBMC by 5.9 +/- 1.5-fold (n = 7, mean +/- s.d.), and IgG synthesis of adult PBMC by 16.3 +/- 5.1-fold (n = 3) at optimal concentrations of 10(-6) M and 10(-11) M, respectively. No augmenting effects could be demonstrated for the other immunoglobulin isotypes. Time-course studies showed that the synthesis of IgM by CBMC was accelerated with detectable immunoglobulin in supernatant fluids starting on day 3. ROH augmented immunoglobulin synthesis of CBMC stimulated by Epstein-Barr virus (EBV), a T cell-independent polyclonal activator, and of EBV-transformed B cell clones (2.5 +/- 0.2 and 4.1 +/- 1.5-fold increase, respectively), which suggests that ROH can act directly on B cells to enhance immunoglobulin synthesis. In contrast, when ROH was preincubated with cord blood T cells, washed and added to the B cell-enriched fraction with SAC, no increase (0.9-1.8-fold) in IgM synthesis was obtained. Thus, the principal mechanism(s) by which ROH augments immunoglobulin synthesis is by acting on B cells. This is in contrast to the immunoglobulin-enhancing effects of RA which is mediated by T cells, or T cell products, e.g. cytokine. Our studies suggest that RA and ROH may have different pathways of immunoglobulin-enhancing effects, perhaps mediated by different retinoid binding proteins resulting in gene activation and immunoglobulin synthesis.
A theoretical study of lithium ion and aromatic organic cation graphite intercalates

A theoretical study was performed to design a method for predicting the intercalation behavior of lithium ion and aromatic organic cations into a graphite lattice. The purpose of these predictive capabilities is to provide fundamental information on the molecular interactions in graphite intercalates for optimization of electrodes in rechargeable batteries. The graphite sheet system was modeled on a workstation using MOPAC 93 to observe possible structural changes in the graphite following an intercalation process as well as any molecular orbital interactions between the graphite and the cation. Initial modeling of the graphite sheets used lithium intercalated graphite (LIG) as a benchmark. The results indicate that a complex graphite system can be modeled simply and effectively using semiempirical methods for the study of the intercalation–deintercalation behavior of ions. © 1995 John Wiley & Sons, Inc.
SALT TOLERANCE AND SALT ACCUMULATION OF LANDSCAPE PLANTS IRRIGATED BY SPRINKLER AND DRIP IRRIGATION SYSTEMS

Field trials were conducted to evaluate salt tolerance of landscape plants for recycled-water irrigation. Ten selected landscape plant species exhibited substantial differences in salt tolerance. Plants with more tolerance to salt tend to accumulate less salt than less salt tolerant plants. Plants were more susceptible to salt stress under sprinkler irrigation than under drip irrigation, because leaf direct contact with salt. No apparent salt stress symptom was detected when plants were irrigated by drip irrigation either with 500 mg L−1 or 1500 mg L−1 salt (NaCl). Therefore, drip irrigation using recycled water may be accept-able for many landscape plants in California landscape. There was a positive relationship between the salt tolerance revealed by sprinkler irrigation and the salt tolerance revealed by drip irrigation. This positive relationship is a potentially useful character to screen for salt tolerant landscape plants. Selection for salt tolerant landscape plants for recycled water irrigation is...
Simplified technique for estimating navigational accuracy of interplanetary spacecraft

Navigational accuracy of two way Doppler tracking of interplanetary spacecraft during heliocentric and planetary encounter trajectory phases
Pharmacology of lorcainide.

Abstract Lorcainide is a new type 1 antiarrhythmic drug that is well absorbed orally, with bioavailability increasing with both dose and continued administration. It is metabolized through the liver, and patients with significant liver disease will require dosage reduction. The drug has an active metabolite, norlorcainide, whose activity is similar to that of lorcalnide but whose half-life Is 26 hours instead of 8 for the parent compound. The levels of this metabolite are nearly twice those of lorcalnide at steady state. The long half-life of the metabolite and the changing bioavailability of lorcalnide require that a given dose be administered for 1 week for the maximum effect to be demonstrated.
Probing Ligand Dynamics in Membrane-Bound Cytochrome P450 3A4 to Characterize Substrate Access and Product Egress Pathways

Cytochrome P450 3A4 (CYP3A4) is the most abundant P450 isoform in the human body, and is responsible for the metabolism of more than 50% of clinically used drugs. Recently, we developed a model for the membrane-bound form of CYP3A4, employing a concerted simulation/experimental approach. From the simulations, we observed that the interaction of CYP3A4 with the membrane favors the opening of pathways leading to the active site, which might play a role in the recruitment of lipophilic ligands from the membrane.Using this membrane-bound model, we performed a microsecond-long MD simulation, providing extended conformational sampling for the protein in the presence of the membrane. From this simulation, 850 frames were then used to perform molecular docking to identify potential access/egress pathways for progesterone, representing a substrate of CYP3A4, and its 6b-hydroxy- form, representing an oxidation product. The combination of the long-time scale MD simulation with molecular docking resulted in 8500 docking poses for each ligand.The results indicate that membrane-bound CYP3A4 can accommodate both ligands in regions connecting the active site to peripheral binding sites close to the membrane, suggesting two putative access pathways from the membrane for progesterone. A series of MD simulations, performed on the most representative docking poses for both ligands, revealed that progesterone is more mobile than the product in the peripheral binding sites, and can reach the active site through the suggested pathways. Once in the active site, progesterone freely rotates and adopts different orientations, which might account for the ability of CYP3A4 to oxidize progesterone at different sites. Finally, the results of the MD simulations of 6b-hydroxy-progesterone suggest a putative egress pathway connecting the active site to the aqueous phase.
Left Atrial Appendage Devices for Stroke Prevention in Atrial Fibrillation

Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia, and stroke prevention remains an integral part of management of AF. Long-term therapy with oral anticoagulants, though effective, has many limitations, and these limitations have encouraged the search for device-based alternatives. In patients with non-valvular AF, approximately 90% of thrombi are thought to arise from the left atrial appendage (LAA). The LAA can be obliterated surgically or percutaneously, and this should reduce the incidence of systemic thromboembolic events in AF, ideally without the need for further anticoagulation. We explore the currently available LAA occlusion devices and the evidence behind these devices. Although additional evidence from randomized trials is required to fully characterize the safety and efficacy of all of these devices, LAA occlusion has the potential to offer an attractive alternative for those at high stroke risk but are under-protected because of contraindications to anticoagulant therapy.
Zero offset in computer-recorded analog data in measuring aerosol scattering coefficient: a “threshold” or a “blank”?

Abstract When measuring the aerosol scattering coefficient (ASC) with an integrating nephelometer, the instrumental “zero” value is established by passing filtered, particle-free air (zero air) through the instrument and setting the instrumental analog signal to zero. Ideally, the computer logged analog value of the zero air should also be zero. However, more commonly a non-zero analog value (zero offset) is obtained. This zero offset is normally regarded as a “blank” and the value is subtracted from the data values. During a one-month field experiment where we measured ASC, we consistently obtained a zero offset that ranged from 4 to 25 mV (equivalent to ASC values of 0.8 to 5×10-6 m-1). In this paper, we demonstrate that the zero offset we observed is in reality a threshold to the recorded analog data and that it should not be subtracted from the data record. Treating the zero offset as a blank could lead to an error in ASC data of as high as 21%. The zero offset observed in our experiment was not produced by the nephelometer. Rather, it was generated during the transmission of the analog signal from the instrument to an analog-to-digital converter. Thus, our results should serve as a caution for those who perform ASC or other measurements using analog data transmission.
The effect of a field-independent polarization discontinuity on heterojunction characteristics

A new utilization of the basic semiconductor heterojunction is proposed which is based on the mechanism of a field-independent polarization discontinuity P at the interface of a p-n heterojunction. Variations in P yield changes in the space-charge regions and the associated barrier voltages at the interface. By proper choice of the heterojunction parameters, the barrier voltage change can be made approximately linear with P over a finite range. The barrier voltage variation modulates the I-V characteristic of the heterojunction for the case of a positive reverse interface barrier, and modifies the C-V relation in all cases. Typical values are calculated for the properties of the general polarization discontinuity heterojunction, and of a strain-sensitive unit which utilizes a piezo-electric interaction. For the latter, the calculated differential sensitivities are 102to 103and 104to 105volts per unit strain for the barrier voltage and device output voltage, respectively. This output voltage sensitivity is 1 to 2 orders of magnitude larger than that available in piezoresistive strain gages. This device concept has potential in a variety of technically important areas ranging from mechanical instrumentation to sequentially excited light-emitting arrays. The heterojunction configuration is compatible with both evaporated and epitaxial semiconductor technology, and materials with the necessary combination of physical properties are represented among the well-known II-VI and III-V compounds.
New York State’s Approach to Asset Management: A Case Study:

The New York State Department of Transportation (NYSDOT) has undertaken an effort to design and implement an asset management system for overseeing the state's diverse and complex transportation system. The department has built an appropriate organizational and business foundation for the effective use of sound, integrated databases and technical modeling tools. For more than a decade, well before asset management attracted interest from the transportation community, NYSDOT has advanced this concept on four fronts: developing well-defined organizational roles within a highly decentralized department; designing and implementing a formal and disciplined core business procedure (the program update process) to cover both program development and performance monitoring; developing key transportation management systems (pavement, bridge, congestion and mobility, and public transportation), even without a federal mandate; and designing and implementing a state-of-the-art automated program and project management system that serves, in part, to integrate the department's use of the individual management systems and maintains all essential data for developing and managing the program. New York's experience strongly suggests that despite the difficulty and time required to carry out the key processes, these four elements represent the heart of an asset management system. When identifying and developing additional technical elements, state departments of transportation should heed the importance of building and maintaining an effective organizational and business foundation.
Cooking Camp Provides Hands-On Nutrition Education Opportunity

Making healthy food choices requires far more than nutrition knowledge. Food preparation skills are essential in order to prepare healthful, palatable meals that meet dietary recommendations for ch...
Transmission photoelasticity of centrally loaded generally and specially orthotropic beams

Transmission photoelastic patterns for generally and specially orthotropic beams and an isotropic beam are presented. Theoretical isochromatic and isoclinic results for these beams, calculated from classical elasticity stress equations and stress-optic laws, are also presented and compared with experiment. The agreement between the theory and experiment is excellent. For the orthotropic beams, a stressoptic law which accounts for the effects of residual birefringence was used. The residual birefringence observed for the composite used in this study is greater than one fringe order and results from a matrix residual tension which is about one fourth of the resin's ultimate tensile strength. Finally, the influence of such a large residual birefringence on beam and calibration photoelastic data is discussed in detail.
Human vs model observers in anatomic backgrounds

Model observers have been compared to human performance detecting low contrast signals in a variety of computer generated backgrounds including white noise, correlated noise, lumpy backgrounds, and two component noise. The purpose of the present paper is to extend this work by comparing a number of previously proposed model observers (non-prewhitening matched filter, non-prewhitening matched fitler model with an eye filter, Hotelling observer and channelized-Gabor Hotelling observer model) to human visual detection performance in real anatomic backgrounds (x-ray coronary angiograms). Human and model observer performance are compared as a function of increasing added white noise. Our results show that three of the four models (the non-prewhitening matched filter, the Hotelling and channelized-Gabor Hotelling) are good predictors of human performance.
Settings of a Professional Lifetime

I was born in Iowa in 1903. My forbearers came from Western Europe in the seventeenth century and were pioneers in the westward movement. At the time of my birth, they were businessmen and government officials in the small communities of Western Iowa. The first 7 years of my life were spent in one of these small towns where my father ran the general store. I had a happy early childhood in our family of five children.
Genetic recombination in bacteriophage f1: Transfer of parental DNA to the recombinant

Abstract We have analyzed the relationship between the parental and the recombinant DNA in crosses performed with bacteriophage f 1 . To label the parental DNA, we used the modification imparted to the DNA of f 1 by a host of the B restriction-modification type, lysogenic for P 1 . The parents used had an amber mutation in gene II; their genomes were expected to be unable to multiply in the host prior to a recombination event. The results obtained show that a considerable fraction of the cells, in which a recombination event occurs release a recombinant whose genome consists at least in part of parental DNA. They also confirm that f 1 genomes having an amber mutation in gene II are totally or almost totally unable to multiply in a nonpermissive host.
NOx catalytic ozone destruction: Sensitivity to rate coefficients

Model sensitivity experiments were conducted by using correlated ensemble variations of reaction rate coefficients. For all the simulation experiments tested, the theoretically derived concentration profiles of trace species were in comparable agreement with stratospheric observations. Thus current stratospheric measurements seem to be inadequate to assist in reducing the current uncertainties in kinetic rate data. Given this current range of uncertainties in rate coefficients, it is found that by varying as few as three rate coefficients within the estimated (Hampson and Garvin, 1975) uncertainty range the effect on ozone of lower stratospheric injection of NOx can be reversed. Consequently, it is clear that as a first step toward further progress more precise laboratory measurements of certain reaction rate coefficients are needed.
Response of multiple collimator systems to extended sources

Abstract We found straightforward relationships for determining the geometrical response of a collimated detector to an extended source; the results are applicable to multiple collimator systems, as well as to nonisotropic sources. The formulae are given in the form of integrals that must be numerically evaluated.
Suppression of postpartum fertility in pairs of female rats sharing the same nesting environment

The probability that a successful pregnancy will follow postpartum estrus in the rat is significantly reduced when the postpartum female is housed with another female that is both pregnant and lactating. We studied 16 pairs of females, each pair maintained in a separate nesting environment containing a sexually active male. In 12 of the pairs, the female that gave birth in the presence of a lactating-pregnant partner either did not mate, mated but failed to implant, resorbed her fetuses or delivered non-viable young. Several mechanisms that might underlie this evident suppression of fertility are discussed.
Inhibition of radical adduct reduction and reoxidation of the corresponding hydroxylamines in in vivo spin trapping of carbon tetrachloride-derived radicals.

Abstract In vivo spin trapping of radical metabolites has become a promising tool in understanding and predicting toxicities caused by different xenobiotics. However, in biological systems radical adducts can be reduced to electron paramagnetic resonance (EPR)-silent hydroxylamines. To overcome this difficulty, different procedures for reoxidation of the reduced radical adducts were systematically investigated and some metabolic inhibitors of nitroxide reduction were tested. As a test system, carbon tetrachloride (CCl4), a known hepatotoxic substance, was used. CCl4 is metabolized by liver to .CCl3 and, in the presence of the spin trap phenyl N-t-butylnitrone (PBN), forms the PBN/.CCl3 and PBN/.CO2− radical adducts. These radical adducts were measured in the bile using electron paramagnetic resonance after administration of CCl4 and PBN to the rat. We have shown that these radical adducts were reduced to the corresponding hydroxylamines in vivo, since immediately after the collection of bile only traces of the radical adducts could be detected, but after oxidation by different procedures such as bubbling with oxygen, addition of mild oxidant potassium ferricyanide or autoxidation the EPR spectra intensity increases, indicating that the hydroxylamines had been re-oxidized back to nitroxides. The collection of bile into plastic Eppendorf tubes containing the sulfhydryl reagent N-ethylmaleimide (NEM) or the enzyme ascorbate oxidase did not increase the intensity of the spectra significantly, demonstrating that neither reduction by reduced glutathione (GSH) nor ascorbic acid occurred ex vivo. However in the presence of NEM faster re-oxidation was observed. A new radical adduct that was not observed previoulsy in any in vivo experiment and which exhibited 13C hyperfine coupling was detected when the rats were injected with 13CCl4. We have proven that this is the same adduct detected previously in vitro in microsomal incubations of CCl4, PBN, GSH, and reduced nicotinamide adenine dinucleotide phosphate (NADPH). As a general rule, we have shown that a variety of oxidation procedures should be tried to detect the different radical adducts which are otherwise not observable due to the in vivo reduction of radical adducts.
A closed‐loop proposal for hydrogen generation using steel waste and a prototype solar concentrator

An economically viable and environmental-friendly method of generating PEM grade hydrogen has been proposed and is by the reaction of certain metals with steam, appropriately called ‘metal–steam reforming’—MSR. The drawbacks of conventional processes (hydrogen and carbothermic reduction schemes) are overcome by resorting to solution-based reduction schemes and are made economically feasible using iron oxides from steel industry's mill-scale waste. A novel aqueous-based room temperature technique using sodium borohydride (NaBH4) as the reducing agent has been developed that produces highly active nanoscale iron particles (∼40 nm). By using hydrazine as an inexpensive and, compared with NaBH4, more stable reductant, body centered cubic iron particles with ∼5 nm edges were obtained via solvothermal process under mild conditions from acid digested mill-scale waste. The nanoscale zerovalent iron (nZVI) powder showed improved kinetics and greater propensity for hydrogen generation than the coarser microscale iron. The rate constants for the MSR were obtained for all the reduction schemes employed in this work and are given by khydrogen=0.0158 min−1kcarbon=0.0248 min−1ksodiumborohydride=0.0521 min−1 and khydrazine=0.1454 min−1, assuming first order kinetics. Another innovative effort converted the magnetite waste directly into nZVI under solvothermal conditions, thus obviating the sluggish and time-consuming acid dissolution step. This particular aspect has significant ramification in terms of time and cost of making the iron precursor. To initiate and sustain the somewhat endothermic MSR process, a solar concentrator consisting of a convex polyacrylic bowl with reflective aluminum coating was fabricated and evaluated. This unique combination of mill-scale waste as iron source, hydrazine as reductant, mild process conditions and solar energy as the MSR actuator obviates several drawbacks plaguing the grand scheme of producing and delivering pure and humidified H2 to a PEMFC stack. Copyright © 2008 John Wiley & Sons, Ltd.
Trade-offs between mitigation costs and temperature change.

This paper uses the MERGE integrated assessment model to identify the least-cost mitigation strategy for achieving a range of climate policies. Mitigation is measured in terms of GDP foregone. This is not a benefit-cost analysis. No attempt is made to calculate the reduction in damages brought about by a particular policy. Assumptions are varied regarding the availability of energy-producing and energy-using technologies. We find pathways with substantial reductions in temperature change, with the cost of reductions varying significantly, depending on policy and technology assumptions. The set of scenarios elucidates the potential energy system transformation demands that could be placed on society. We find that policy that allows for “overshoot” of a radiative forcing target during the century results in lower costs, but also a higher temperature at the end of the century. We explore the implications of the costs and availability of key mitigation technologies, including carbon capture and storage (CCS), bioenergy, and their combination, known as BECS, as well as nuclear and energy efficiency. The role of “negative emissions” via BECS in particular is examined. Finally, we demonstrate the implications of nationally adopted emissions timetables based on articulated goals as a counterpoint to a global stabilization approach.
Kernel Approach for Modeling Interaction Effects in Genetic Association Studies of Complex Quantitative Traits

The etiology of complex traits likely involves the effects of genetic and environmental factors, along with complicated interaction effects between them. Consequently, there has been interest in applying genetic association tests of complex traits that account for potential modification of the genetic effect in the presence of an environmental factor. One can perform such an analysis using a joint test of gene and gene-environment interaction. An optimal joint test would be one that remains powerful under a variety of models ranging from those of strong gene-environment interaction effect to those of little or no gene-environment interaction effect. To fill this demand, we have extended a kernel machine based approach for association mapping of multiple SNPs to consider joint tests of gene and gene-environment interaction. The kernel-based approach for joint testing is promising, because it incorporates linkage disequilibrium information from multiple SNPs simultaneously in analysis and permits flexible modeling of interaction effects. Using simulated data, we show that our kernel machine approach typically outperforms the traditional joint test under strong gene-environment interaction models and further outperforms the traditional main-effect association test under models of weak or no gene-environment interaction effects. We illustrate our test using genome-wide association data from the Grady Trauma Project, a cohort of highly traumatized, at-risk individuals, which has previously been investigated for interaction effects.
Influence of acetaldehyde, dietary protein, carbon tetrachloride and butylatedhydroxytoluene on the toxicity of methylmercury in rats.

The influence of environmental or dietary factors on the toxicity of methylmercury (MeHg) was investigated due to possibilities that humans exposed to methylmercury may have been sensitized. Groups of 8 rats were exposed to 0, 20 or 40 ppm MeHg in a semisynthetic diet and fed 0.5% BHT, 5% protein (instead of 15%), or injected with 250 mg/kg CCl4, or acetaldehyde. In control rats neurotoxicity occurred at 4 weeks and 9 weeks with 40 and 20 ppm MeHg, respectively. Mortality was observed at 6 weeks with 40 ppm and 1 rat died in week 9 with 20 ppm MeHg. Acetaldehyde injected rats died at week 4 and 6 when fed 40 or 20 ppm MeHg. Neurotoxicity was observed in week 3 and 5 in these groups, respectively. Treating rats with the low protein or BHT accelerated neurotoxicity and mortality by 1 week with 40 ppm MeHg. These agents had killed all test animals within 7 weeks at 20 ppm MeHg. Neither acetaldehyde nor BHT influenced 0 ppm MeHg controls while 5% protein induced precipitous weight loss. In the case of CCl4, the rats lived longer in combination experiments than one would have expected from the individual treatments.
A survey of the systematic use of macros in systems building

Assemblers with macro capabilities have been available for over ten years. There has been a limited number of mainly unpublished systematic uses of such capabilities in the construction of a variety of systems. This paper will cover a number of these cases. We will examine the features of the macro systems which allowed their usage as well as the method used in the system implementation. We will comment on the effect on efficiency and flexibility that the use of this facility has produced.
Re-conceptualizing Validity within the Context of a New Measure of Mathematical Knowledge for Teaching

The authors of the focus articles have provided a suite of very stimulating and thoughtful articles. The overarching purpose of this research is to explore the application of principles derived fro...
Dynamics of a Materially Closed Model Ecosystem

Abstract This paper deals with model ecosystem consisting of biotic and abiotic components. The biotic component was represented as populations of organisms with particular eco-physiological traits and individual properties. Interspecific relationships consisted of exploitation competition and prey-predator interactions. The system was composed of populations that consume energy, represented as amount of matter for life activities, and was closed materially. The system was studied for the conditions under which populations coexist. Results showed that the total amount of substances, represented as the summation of standing stocks of organisms and inorganic materials, was important for the coexistence of the populations. Also, if the length of the food chain were less than four, and the traits were closer to real values, the system was stable in a state of competition for the same food, regardless of the differences in the traits between the populations competing.
Technical Analysis of the Slosson Phonics and Structural Analysis Test

Technical characteristics of Slosson Phonics and Structural Analysis Test (SP-SAT) scores were studied using three independent samples of boys and girls aged 6 years, 6 months, through 9 years, 11 months. A decision efficiency study (n = 100) resulted in a total predictive value of .86 (sensitivity = .95, specificity = .77, positive predictive power = .80, negative predictive power = .94). Item difficulty was .65 (median), and item discrimination was .52 (median). Interitem consistency was r = .93, .93, and .96 for scores on the Phonics Index, Structural Analysis Index, and SP-SAT total standard score, respectively (n = 375), whereas 2-week test-retest reliability was r = .90, .88, and .90 for scores on the same scales, respectively (n = 165). The SP-SAT yielded moderate to high concurrent validity coefficients when compared with the Wide-Range Achievement Test-Third Edition Reading subtest; Woodcock-Johnson: Tests of Achievement-Third Edition Letter-Word Identification, Word Attack, Passage Comprehension...