cssi/SciSciGPT-SciSciNet huggingface dataset:
Adhesion of cells to random copolypeptide films.

The kinetics of attachment of NIL B and SV-NIL cells to glass, siliconized glass, and surfaces coated with random copolypeptides have been studied. It was found that in the absence of serum proteins, neither the rate nor the extent of attachment of cells is affected by the nature of the surface. In the presence of bovine serum albumin, the total uptake and rate of attachment of both NIL B and SV-NIL cells to the neutral, hydrophobic, and negatively charged copolymers is decreased compared with attachment to the same surfaces in the absence of protein. In contrast, the attachment of NIL B and SV-NIL cells to the positively charged (lysyl) copolymers was not decreased in the presence of protein. It was shown that the effect of protein resulted from its adsorption to the surface rather than to the cells. It was also concluded that both the NIL B and SV-NIL cells consist of a single cell population with respect to adhesiveness, and that both cell lines reach a kinetic equilibrium with the surfaces. This work represents one of the first studies to vary copolypeptide compositions systematically from negatively to neutral to positively charged surface and to examine these substrates without any mediating effects from various serum proteins. The results of this study support the concept that while cells bind to an adsorbed layer of protein rather than directly to the surface, the underlying surface can modify the attachment process by its effect on the protein adsorbed.
Simple Technique for Sequential Q-Switching of Molecular Lasers

A simple technique for sequentially Q-switching molecular lasers (e.g., CO(2), CO, HF) is discussed in which an optical scanner is used as an optical folding element in a laser cavity consisting of a stationary diffraction grating and partially reflecting mirror. Sequential Q-swtiching of a conventional CO(2) laser is demonstrated in which over sixty-two transitions between 9.2 micro and 10.8 micro are observed. Rapid repetition rates (200 Hz) and narrow laser pulses (<5 microsec) allow conventional signal processing techniques to be used with this multi-wavelength laser source which is a versatile tool for laser propagation studies, absorption spectroscopy, and gain measurements. Results of a preliminary experiment demonstrating the utility of measuring selective absorption of CO(2) laser wavelengths by C(2)H(4) is shown, but selective absorption by atmospheric CO(2), NH(3), and O(3) can also be studied. With appropriate optical sca ners and diffraction gratings, sequential Q-switching of CO and HF lasers is possible.
Control of a climbing robot using real-time convex optimization

This dissertation describes a controller and a control framework to enable a robot to rock climb. The specific application that motivated this research is the exploration of cliff sites on Mars. These steep slopes are of particular interest to researchers because it is believed that they are the most likely location to find evidence of water on Mars. In order to climb these surfaces without disturbing them, a robot will need to carefully pick its way across irregular terrain while utilizing the frictional properties of the surface and being careful not to fall. A robot climbing in such a scenario is heavily constrained. It has limited torque capabilities, needs to monitor the force conditions in each hand to be sure it's not about to slip off its holds, and must deal with uncertainties in both the state of the robot itself and of the environment its climbing in. A climbing robot also has more actuators than positional degrees of freedom, meaning the motors can be used to accomplish many tasks. For example, they can maintain the robot's position, adjust the forces at each hand to make sure they don't slip, and balance the forces among all the arms. With these constraints and advantages in mind, a controller is proposed here that calculates motor inputs which satisfy the constraints, follow a planned path, and use the extra degrees of freedom to improve the robot's robustness. This controller is set in a framework that includes a number of different parts. First, a time is associated with a set of statically stable waypoints that define a route up a wall in order to determine how quickly the robot can feasibly climb. The desired route is then compared with the actual robot body position, which is estimated via a Non-Linear Least Squares (NLLS) technique. A Cartesian controller computes a desired body force and then this force is checked to see if is allowable (i.e., it won't make the robot jump). The body force is then converted to joint torques by using a Linear Program convex optimization technique. This optimization includes all the constraints and objectives of the robot phrased as linear constraints with a linear objective function designed to make the robot more robust. The Cartesian controller, dynamic feasibility check and LP together are called Cartesian Force Convex (CFC) control. Also included as part of this control technique is a Finite State Machine (FSM) to switch between modes of control when hands become free of their holds or are making and breaking contact. Furthermore, since command of joint torques is a key part of this control, techniques for estimating the torque in each joint are described for both direct drive motors and geared motors with tip force sensors. This control framework is demonstrated on three robotic platforms. These are JPL's LEMUR robot, the Free-flyer robot, and the Capuchin robot. The experiments and simulations on these platforms demonstrate the controller's ability to operate in real time and to make a robot climb relatively quickly through irregularly placed, difficult, and uncertain terrain.
Fine particulate air pollution and its components in association with cause-specific emergency admissions

Although the association between exposure to particulate matter and health is well established, there remains uncertainty as to whether certain chemical components are more harmful than others. We explored whether the association between cause-specific hospital admissions and PM2.5 was modified by PM2.5 chemical composition. We estimated the association between daily PM2.5 and emergency hospital admissions for cardiac causes (CVD), myocardial infarction (MI), congestive heart failure (CHF), respiratory disease, and diabetes in 26 US communities, for the years 2000-2003. Using meta-regression, we examined how this association was modified by season- and community-specific PM2.5 composition, controlling for seasonal temperature as a surrogate for ventilation. For a 10 μg/m3 increase in 2-day averaged PM2.5 concentration we found an increase of 1.89% (95% CI: 1.34- 2.45) in CVD, 2.25% (95% CI: 1.10- 3.42) in MI, 1.85% (95% CI: 1.19- 2.51) in CHF, 2.74% (95% CI: 1.30- 4.2) in diabetes, and 2.07% (95% CI: 1.20- 2.95) in respiratory admissions. The association between PM2.5 and CVD admissions was significantly modified when the mass was high in Br, Cr, Ni, and Na+, while mass high in As, Cr, Mn, OC, Ni, and Na+ modified MI, and mass high in As, OC, and SO4 2- modified diabetes admissions. For these species, an interquartile range increase in their relative proportion was associated with a 1-2% additional increase in daily admissions per 10 μg/m3 increase in mass. We found that PM2.5 mass higher in Ni, As, and Cr, as well as Br and OC significantly increased its effect on hospital admissions. This result suggests that particles from industrial combustion sources and traffic may, on average, have greater toxicity.
Fibonacci and binomial properties of weighted compositions

Abstract A general formula for summation over weighted compositions is developed. From this a number of particular results involving the Fibonacci numbers and binomial coefficients are deduced.
A neural architecture applied to the enhancement of noisy binary images

Abstract Neural networks represent a new dimension in computing, both in concept and in implementation. Their applications are varied with many significant and exciting developments which have been developed in the field of image processing, among others. This paper presents the formulation of one improved architecture, a modified Adaptive Resonance Theory (ART), for the enhancement of noisy binary images. The operation and performance of the traditional ART1 in classifying binary input patterns are first investigated. Based upon the ART1, a noise-filtering architecture is devised, whereby pre-established recognition categories are used as edge-detection exemplars. Experimental results of applying the architecture to perform edge detection and region enhancement are also provided.
Thyrotropin-Releasing Hormone-Stimulated Pituitary and Thyroid Gland Responsiveness and 3,5,3′-Triiodothyronine Suppression in Fetal and Neonatal Lambs*

To evaluate the development of the pituitary thyroid axis and negative feedback control of TSH secretion, ovine TSH (oTSH) and T4 were measured by RIA in plasma samples obtained before and 15, 30, 60,120, and 240 min after an iv bolus injection of TRH in fetal lambs between 105-113 days gestation (group I) and between 125–129 days gestation (group II); newborn lambs also were injected between 7–12 days of age (group III). In each group, the TRH injection and plasmasampling protocols were repeated 14–18 h after an iv injection of T3. Plasma oTSH concentrations increased in all animals in response to TRH injection. Neither the difference between the peak and baseline plasma concentrations (ΔTSH) nor the integrated area under the plasma concentration-response curves (∫TSH) correlated with gestational age. Both responses, however, correlated with baseline oTSH concentrations (r = 0.72 and r = 0.73, respectively; P < 0.02 for both) and both (ΔTSH and ∫TSH) were significantly decreased in group III newborn anim...
The redox state of the mitochondrial NAD system in cirrhosis of the liver and in chronic quantitative undernutrition in the rat

1. 1. To determine the redox state of the mitochondrial NAD system in cirrhosis of the liver and in chronic quantitative undernutrition, the substrates of the l-glutamate dehydrogenase (EC 1.4.1.2) and d-β-hydroxybutyrate dehydrogenase (EC 1.1.1.30) reactions were measured. The livers of animals fed ad libitum served as controls. 2. 2. Assuming these substrates to be in equilibrium, the NAD+/NADH ratio calculated from the substrates of the l-glutamate dehydrogenase reaction was lower in all three groups of animals than that calculated from the d-β-hydroxybutyrate dehydrogenase reaction. On the other hand, the ratio ([β-hydroxybutyrate] × [α-ketoglutarate] × [NH4+])([acetoacetate] × [glutamate]) was similar in all three groups of animals. 3. 3. These data suggest that in these animals the mitochondrial NAD+-NADH system is in equilibrium provided a H+ concentration gradient can be postulated between the sites of d-β-hydroxybutyrate dehydrogenase and l-glutamate dehydrogenase.
Grain boundary structure and energetics

The subject of grain boundary structure and energetics is reviewed, with the progress over forty years measured in terms of describing boundaries with greater misorientation and with greater crystallographic complexity. Approaches based on continuum and lattice geometric concepts are discussed, with the emphasis placed on delineating the limitations inherent in each approach. Grain boundary energy measurements of relative and absolute energies are then described briefly. Experimental techniques stressed are those which provide accurate and incisive information on energy as a function of misorientation. The theory of heterophase dislocations is then discussed in terms of predicting equilibrium states at grain boundaries. New variational formulations of constrained and unconstrained equilibrium are presented, which yield differential equations for microscopic equilibrium in terms of the chemical and elastic energy density distributions along a grain boundary. The precise equilibrium form of the strain accommodation centers periodically distributed along a boundary is shown to be a unique eigenfunction of the constrained equilibrium equation. The influence of a second component on heterophase grain boundaries is presented along the lines first shown by Voronkov. Both the grain boundary " surface excess " and the stress-modified diffusion of the solute are considered. Finally, the influence of boundary structure on the segregation, Gibbs absorption, and diffusion of solutes is shown to be significant even in the case of relatively simple boundaries of modest (<15 deg) misorientation.
Organization of the striate-recipient zone of the cat's lateralis posterior-pulvinar complex and its relations with the geniculostriate system

Abstract The extrageniculate visual thalamus of the cat is divisible into several major subdivisions but only one receives dense fiber projections from the striate cortex. In the present study, modern axon transport techniques and acetylcholinesterase histochemistry were used to examine the internal organization of this striate-recipient zone and some of its afferent and efferent connections. A detailed study of the corticothalamic fiber projections of the striate cortex clarified the topographic organization and boundaries of the striate-recipient zone. The nature and course of “projection lines” within the zone were defined and the subdivision was shown to correspond closely to a region of relatively weak acetylcholinesterase staining. Corticothalamic projections from two regions of the extrastriate visual cortex, area 19 and the medial division of the Clare-Bishop complex, converge with those from area 17 in the striate-recipient zone, but these extrastriate areas have more widespread projections to the extrageniculate thalamus than does the striate cortex. A weak subcortical projection to the striate-recipient zone was demonstrated, apparently originating in the superior colliculus. Retrograde tracing experiments indicated that the corticothalamic inputs of the striate-recipient zone are precisely reciprocated by thalamocortical projections. Extrageniculate thalamic projections to area 17 arise exclusively from this thalamic subdivision and are highly topographically ordered. The striaterecipient zone projects massively and apparently retinotopically to area 19 and to the medial division of the Clare-Bishop area, as well as area 21(a), but these extrastriate areas receive additional afferents from other subdivisions of the extrageniculate thalamus. These findings appear to rule out a “non-specific” functional role for the striate-recipient zone. In its topographic organization, its reciprocal connections with areas of the visual cortex, and its sheer volume, the zone seems comparable to the dorsal lateral geniculate nucleus and may be fairly considered a satellite of the geniculocortical system. Certain of the zone's organizational and connectional features may be clues to its functional role and its possible homologues in other mammalian forms.
An energy-gap correlation of internal conversion rates

Abstract Experimental internal conversion data have been analyzed separately for alternant polyacenes and substituted azulenes with the formalism derived by Siebrand. In each case a good correlation of internal conversion rate with a scaled electronic energy gap is found.
Human naive and memory T cells: reinterpretation of helper-inducer and suppressor-inducer subsets

Abstract The subsets of human peripheral blood T cells identified by CD45R antibodies (such as 2H4) and by CDw29 antibodies (such as 4B4) are assuming increasing importance in studies of both basic immunology and clinical medicine. Here, Martin Sanders and colleagues propose that these subsets represent naive and memory (previously activated) T cells, respectively, and discuss the current understanding of these subsets in the light of this reinterpretation.
Medicine and the Movies: Lorenzo's Oil at Century's End.

Augusto and Michaela Odone (Nick Nolte and Susan Sarandon) resolve to learn all they can about their son's illness. Lorenzo's Oil provides a case worth examining not only for its own story but also...
Staff Perceptions of Same-Gender Sexual Contacts in Long-Term Care Facilities

An ongoing fear in the gay and lesbian community is that long-term care (LTC) facilities may not be sensitive to their needs. In the present study, 218 LTC staff members responded to one of three vignettes in which resident sexual contact was observed, with only the gender of the characters changing, to create different gender pairings. Results suggested that staff rated male-male and female-female pairings more negatively than heterosexual intimacy. Knowledge about older adult sexuality made little difference in staff ratings. However, staff attitudes were directly related to ratings of negative reaction and level of acceptability of same-gender sexuality.
Arsenic content of small mammals indigenous to old orchard soils

Small mammals such as mice and voles which inhabit the immediate surface of old orchard soils typically consume plant parts, insects, organic debris and necessarily adhering soil particles containing accumulated arsenic residues. In an earlier study it was shown that lead accumulated to concentrations up to 400 ppm dry weight in bone of pine voles inhabiting such orchard soils. High concentrations of lead were also found in liver and kidney of these mammals (ELFVING et al. 1978). Individual tissue samples were too small to permit analysis of arsenic. In the work reported, small mammals were trapped in a number of orchards in New York which had received multiple applications of inorganic arsenic compounds annually for many years. The entire body burden of arsenic was then determined in the animals.
Uncovering potential 'herbal probiotics' in Juzen-taiho-to through the study of associated bacterial populations

Juzen-taiho-to (JTT) is an immune-boosting formulation of ten medicinal herbs. It is used clinically in East Asia to boost the human immune functions. The active factors in JTT have not been clarified. But, existing evidence suggests that lipopolysaccharide (LPS)-like factors contribute to the activity. To examine this possibility, JTT was subjected to a series of analyses, including high resolution mass spectrometry, which suggested the presence of structural variants of LPS. This finding opened a possibility that JTT contains immune-boosting bacteria. As the first step to characterize the bacteria in JTT, 16S ribosomal RNA sequencing was carried out for Angelica sinensis (dried root), one of the most potent immunostimulatory herbs in JTT. The sequencing revealed a total of 519 bacteria genera in A. sinensis. The most abundant genus was Rahnella, which is widely distributed in water and plants. The abundance of Rahnella appeared to correlate with the immunostimulatory activity of A. sinensis. In conclusion, the current study provided new pieces of evidence supporting the emerging theory of bacterial contribution in immune-boosting herbs.
Comparison of Transcatheter Closure of Secundum Atrial Septal Defect Using the Amplatzer Septal Occluder Associated With Deficient Versus Sufficient Rims

To evaluate the feasibility of transcatheter closure of secundum atrial septal defects (ASDs) associated with deficient rims ( 5 mm) who underwent closure served as controls. There were no differences between the 2 groups in ASD stretched diameter and device size (p >0.05). Of 23 patients with deficient rims, 17 (74%) had immediate complete closure compared with 44 of 48 patients (92%) with sufficient rims (p <0.05). At 24-hour and 6-month follow-up, the complete closure rates were not significantly different between the 2 groups (91% for patients with deficient rims vs 94% for patients with sufficient rims at 24 hours and 100% vs 93% at 6 months, respectively). The fluoroscopic time and procedure time were longer in patients with deficient rims (13 ± 7 and 72 ± 26 minutes, respectively) compared with those with sufficient rims (10 ± 4 and 61 ± 22 minutes, respectively). No major complications were encountered either during or after the closure procedure in both groups. Thus, transcatheter closure of ASDs associated with small anterior, inferior, or posterior rims is feasible using an ASO. Long-term follow-up data are still needed to assess long-term safety and efficacy.
Acetylator genotype-dependent N-acetylation of arylamines in vivo and in vitro by hepatic and extrahepatic organ cytosols of Syrian hamsters congenic at the polymorphic acetyltransferase locus

Our laboratory recently reported the successful construction of homozygous rapid (Bio. 82.73/H-Pat r) and homozygous slow (Bio. 82.73/H-Pat s) acetylator congenic Syrian hamsters. These hamsters are isogenic except for the polymorphic acetylator gene locus (Pat) and perhaps other closely linked loci. The purpose of the present investigation was to assess the expression of acetylator genotype both in vivo and in vitro in a variety of hepatic and extrahepatic organ cytosols. Levels of arylamine N-acetyltransferase were generally high and in the relative order: liver > colon > kidney > pancreas > prostate, urinary bladder, and lung. However, an acetylator gene dose-response was clearly expressed in each tissue, with highest levels in homozygousPat r acetylators, intermediate levels in heterozygousPat r/Pat s acetylators, and lowest levels in homozygousPat s acetylators. The magnitude of the acetylator genotype-dependent differences in N-acetyltransferase activity were substrate specific, whereinp-aminobenzoic acid showed the largest differences andp-aminophenol the smallest. The N-acetylation ofp-aminobenzoic acid in vivo also reflected acetylator genotype in the congenic hamsters. These results further document the successful construction of rapid and slow acetylator congenic hamsters which should prove very valuable in future studies to assess the role of acetylator genotype in the toxicity and carcinogenicity of arylamine chemicals.
Coarse-Grained and Atomistic Modeling of Anisotropic Atomic Fluctuations in Protein Crystal Structures

Protein atomic fluctuations can be probed by x-ray crystallography in the form of Anisotropic Displacement Parameters (ADP). In this study, we assess the accuracy of different coarse-grained and atomistic models that include protein-environment interactions in a protein crystal in comparison with experimental ADPs. We use a coarse-grained Elastic Network Model (ENM) with three different boundary conditions (see figure) to model protein-environment interactions, and an atomistic model using a CHARMM force-field. For a large list of high-resolution protein crystal structures, we find that optimal ADP modeling is achieved by weak protein-environment interactions as compared to internal interactions within a protein structure. Therefore, the internal dynamics of a protein is only weakly perturbed by crystal packing. We also find no improvement in the accuracy of ADP modeling by using the atomistic model over the coarse-grained ENM.View Large Image | View Hi-Res Image | Download PowerPoint SlideFigure. A protein-environment system constructed from a protein crystal of oxy-myoglobin (PDB code: 1a6m) with the main protein in red, the nearest neighbors in green, and the next nearest neighbors in blue. The main protein and the nearest neighbors are unconstrained while the next nearest neighbors are fixed.
Design of integrated hybrid silicon waveguide optical gyroscope

We propose and analyze a novel highly integrated optical gyroscope using low loss silicon nitride waveguides. By integrating the active optical components on chip, we show the possibility of reaching a detection limit on the order of 19°/hr/√Hz in an area smaller than 10 cm2. This study examines a number of parameters, including the dependence of sensitivity on sensor area.
The January Global Climate Simulated by a Two-Level General Circulation Model: A Comparison with Observation.

Abstract The mean global distributions of pressure, temperature, wind, moisture, cloudiness, precipitation, evaporation, and surface heat balance simulated for January by the two-level Mintz-Arakawa atmospheric general circulation model are compared with the corresponding observed fields. Although there are a number of shortcomings, in general the large-scale distribution of global climate is reasonably well portrayed by the model, in spite of its limited vertical resolution. The model simulates the semi-permanent cyclones and anticyclones of both the tropics and higher latitudes in approximately their correct positions, together with the associated large-scale temperature and circulation fields of the middle and lower troposphere. In comparison with models of greater resolution, these results suggest that with further selective improvements in the physical parameterizations, relatively coarse global models (of correspondingly lower computational demands) are useful tools in the study of many aspects of c...
Foundations of digital libraries: Organizational & management issues. Sponsored by SIG DL, SIG MGT.

Digital libraries are at a point in their progression where many have been well established. Furthermore, groups in the field have begun to develop best practices in areas such as digitization and metadata architecture. However, other areas have been less discussed, namely the organizational and management issues that digital libraries must address. These issues include staffing, collaboration among departments or institutions, budgeting, and the strategies that digital libraries use to ensure long-term sustainability for projects. Panelists in this session will discuss the strategies that they have used to meet the organizational and management needs of their digital library projects.
Photovoltaic-module encapsulation design and materials selection: Volume 1

Tests for chemical structure, material properties, water absorption, aging and curing agent of Ethylene Vinyl Acetate (EVA) and UV absorption studies are carried out. A computer model was developed for thermal optical modeling, to investigate dependence between module operating temperature and solar insolation, and heat dissapation behavior. Structural analyses were performed in order to determine the stress distribution under wind and heat conditions. Curves are shown for thermal loading conditions. An electrical isolation was carried out to investigate electrical stress aging of non-metallic encapsulation materials and limiting material flaws, and to develop a computer model of electrical fields and stresses in encapsulation materials. In addition, a mathematical model was developed and tests were conducted to predict hygroscopic and thermal expansion and contraction on a plastic coated wooden substrate. Thermal cycle and humidity freezing cycle tests, partial discharge tests, and hail impact tests were also carried out. Finally, the effects of soiling on the surface of photovoltaic modules were investigated. Two antisoiling coatings, a fluorinated silane and perflourodecanoic acid were considered.
Contrasting twitch and latency relaxation in skeletal muscle.

Abstract 1. 1. Twitch and latency relaxation (LR) in excised frog sartorii were compared in muscles exposed to Ringer solution, calcium-free Ringer solution with and without a chelating agent added, caffeine-Ringer solution, increased resting tension, repetitive stimuli and increased temperature. 2. 2. In all muscles except those bathed in caffeine-Ringer solution, LR amplitude either decreased more slowly than twitch amplitude or increased as twitch decreased. In the presence of caffeine twitch amplitude increased as LR decreased. 3. 3. No LR was recorded from toadfish swimbladder muscles. 4. 4. The results suggest that a larger portion of the existing LR may be recorded when the onset of twitch tension is delayed or the rate of tension development slowed.
Detection of colorectal disease by stool defensin assay: an exploratory study.

Background & Aims: Alpha-defensins 1-3 (human neutrophil peptides [HNP]1-3), reported to be elevated in tumor tissue and serum of patients with colorectal cancer (CRC), have not been studied in stool. We evaluated the neoplasm specificity of HPN1-3 and their discriminant value as stool markers for CRC. Methods: Protein and mRNA expression of HPN1-3 were assayed in CRC cell lines, microdissected CRC and normal epithelium, and white blood cells. HNP1-3 proteins in stools were quantified in blinded fashion from 30 normal subjects, 20 patients with CRC, 10 with a large colorectal adenoma, 10 with upper gastrointestinal cancer, and 10 with IBD. Stool lactoferrin was also quantified. Results: HPN1-3 proteins were not detected in CRC cell lines but were high (>4000 ng/mL) in white blood cells. mRNA levels of HPN1-3 were comparably low in CRC cell lines, microdissected CRC, and normal colon epithelium, but they were >1000-fold and >30,000-fold higher in white blood cells and neutrophils, respectively. Mean stool HPN1-3 levels were 17 ng/mL with normals, 125 ng/mL with CRC, 62 ng/mL with adenoma, 63 ng/mL with upper gastrointestinal cancer, and 231 ng/mL with IBD ( P P = .04). At 90% specificity, sensitivity of stool defensins was 35% for CRC, 40% for adenoma, 40% for upper gastrointestinal cancers, and 80% for IBD. Stool defensins and lactoferrin levels correlated ( R 2 = 0.70, P Conclusions: Alpha-defensins 1-3 levels are nonspecifically elevated in stools from patients with colorectal neoplasia and likely originate from white blood cells. Alpha-defensins 1-3 in stool might serve as markers of inflammatory bowel conditions.
4He adsorption isotherms on Na-plated Pyrex glass

We present4He volumetric adsorption isotherm measurements on small area cells made out of Pyrex glass, and the same cells coated with partial platings of evaporated sodium. Isotherms at 4.2K and 3.99K are used to obtain quanititative results for the isosteric heat of adsorption (qst) on bare glass and qualitative results for qst on the Na-plated portion of the cells.
Evaluating cognitive explanations of communicative phenomena

The rise of cognitive approaches to the study of human communication demands an analysis of standards for evaluating such accounts. Three sets of standards are detailed in this essay: necessary requirements, aspects of an explanation needed to advance falsifiable predictions concerning cognitive structures and processes; sufficiency requirements, principles for assessing an explanation with respect to its relationship to relevant data; and aesthetic requirements, matters of quality which concern the intuitive power and appeal of explanations.
Sequential proton NMR resonance assignments, circular dichroism, and structural properties of a 50-residue substrate-binding peptide from DNA polymerase I.

Peptide I, a 50-amino acid synthetic peptide based on residues 728 to 777 of DNA polymerase I, binds dNTP substrates and duplex DNA (G. Mullen, P. Shenbagamurthi, and A.S. Mildvan, J. Biol. Chem. 264, 19637-19647, 1988). The structural properties of peptide I at pH 3.9 have been studied by CD spectroscopy and by 2D proton NMR at 600 MHz. The CD spectra are fit by assuming that peptide I contains 17% helix, 17% beta-structure, and 66% coil. The substrate dATP binds tightly to peptide I under these conditions (KD = 0.5 microM) as determined by fluorescence quenching but induces no change in peptide conformation, as detected by CD spectroscopy. Proton resonances of peptide I have been assigned by double quantum filtered correlated spectroscopy, total correlated spectroscopy, and nuclear Overhauser effect spectroscopy. As found with other peptides, peptide I is best characterized by both extended and partially folded secondary structures which equilibrate rapidly on the NMR time scale. A region from residues 3 through 10 displays nuclear Overhauser effects (NOEs) consistent with the rapid equilibration of a nascent helix with a random extended structure. Alternatively this segment of residues is consistent with a series of three opened-out turns. A nonclassical turn is found between residues 14 and 17 and from residues 44 to 47, the latter closing irregular antiparallel strands from residues 42 to 48. The remainder of the peptide is a coil. A residue-by-residue comparison of the best-fit solution structure of the peptide with that of the corresponding sequence in the X-ray structure of the complete enzyme reveals that 36% of the amino acids are found to be in a conformation similar to that in the enzyme. Such partial and transient folding of the peptide indicates that the major role of the remainder of the protein is to provide structural support for the active site region of the enzyme. As detected by interresidue NOEs and NOEs to water protons, the homologous sequence Leu-37-Ile-38-Tyr-39-Gly-40, together with Phe-15 of the peptide, provides an exposed hydrophobic cluster of residues which may constitute the substrate binding site. An exposed cluster of cationic residues consisting of Arg-27, Arg-28, Lys-31, and possibly Arg-48 may provide the binding site for duplex DNA.
Inventory of computer software designed for use in the accounting curriculum: Student materials and test banks

Abstract This article reports the results of a survey of accounting textbook publishers identifying software designed for use in the accounting curriculum. Software products are classified into two groups: CAI (computer-assisted instructional) materials and test banks. The survey indicates that most CAI materials are designed for the introductory accounting course and operate on microcomputers. Practice sets are available in greater supply than computerized problems, programmed learning materials, and games. Microcomputer-based products can be used by instructors or students with little or no computer expertise and are designed for ease of implementation. Test banks are available for both mainframe and microcomputers. The tables to this article provide detailed information concerning each of the software products identified in the survey.
Associations of urinary phthalates with body mass index, waist circumference and serum lipids among females: National Health and Nutrition Examination Survey 1999-2004.

Exposure to environmental chemicals could be one of the contributors to the increasing obesity epidemic. Very little is known about the association of phthalates, ubiquitous chemicals widely used in consumer products, with obesity and lipid metabolism. This study investigated the association of urinary phthalate metabolites and, for the first time, the ratios of the major metabolites of the most common phthalate, di-2-ethylhexyl phthalate, with body mass index (BMI), waist circumference and serum lipid levels in the US female population. This cross-sectional study used the data from the National Health and Nutrition Examination Survey, 1999–2004 and was restricted to women aged ⩾18 years, who were not pregnant and had no history of diabetes. Using multivariate ordered logistic regression, we examined associations of seven urinary phthalate metabolites and their metabolic ratios with the BMI, waist circumferences, total cholesterol, triglycerides and high- and low-density lipoprotein cholesterol. BMI was positively associated with monobutyl phthalate (MBP) and mono-2-ethylhexyl phthalate (MEHP) (odds ratio (OR)=1.13; 95% confidence interval (CI), 1.03–1.23 and OR=1.12; 95% CI, 1.03–1.23, respectively). Waist circumference was positively associated with MBP (OR=1.13; 95% CI, 1.03–1.24). A higher ratio of MEHP to mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was positively associated with both BMI (OR=1.21; 95% CI, 1.09–1.34) and waist circumference (OR=1.20; 95% CI, 1.10–1.31). There were no other significant associations. A higher metabolic ratio of MEHP to MEHHP, reflective of slower oxidative conversion of MEHP, is associated with greater BMI and waist circumference.
Test of a probe used to sense altitude through measurement of pressure

A STATIC pressure probe was tested to determine the feasibility of using the probe as an integral part of a missile nose to sense missile altitude. Experiments were conducted at Mach 2.0 and at Mach 1.51. At Mach 2.0, the static pressure probe will perform within altitude specifications of 7600 m ± 600 m at angles of attack ranging from -8 to +8 deg. At Mach 2.0, within an angle of attack ranging from 0 to 6 deg, the probe will measure freestream static pressure within 4%; a 4% error in measurement is equivalent to an altitude error of 275 m. The missile nose shock will remain downstream of the probe pressure ports for flight Mach numbers above 1.5.
Hindered internal rotation in S1 meta-chlorotoluene and D0 meta-chlorotoluene+

Abstract Resonant two-photon ionization and pulsed field ionization (PFI) were used to measure the S1-S0 and D0-S1 spectra of internally cold meta-chlorotoluene. Here D0 denotes the (doublet) ground electronic state of the cation. We report the adiabatic ionization potential of meta-chlorotoluene as 71333 ± 5 cm−1 ± 8.8442 ± 0.0006 eV. Low lying torsional levels in both S1 (A1a1) meta-chlorotoluene and D0 (X2A1) meta-chlorotoluene+ are assigned. In both S1 and D0, we extract parameters for a one-dimensional hindered rotor model. In S1 these parameters are F′ = 5.0 ± 0.3 cm−1, V3′ = 110 ± 5 cm−1, and V6′ = - 20 ± 3 cm−1. The parameters in D0 are F+ 5.4 ± 0.2 cm−1, V3+ = − 285 ± 5 cm−1, and V6+ = − 20 ± 3 cm−1. Ab initio calculations from earlier work permit unambiguous assignment of the minimum energy conformation in D0 as pseudo-cis, having one CH bond of the rotor in the plane of the ring on the same side as the chlorine substituent. The PFI intensity patterns then fix the minimum in S1 as pseudo-trans, with one CH bond on the opposite side from chlorine. The strong effects of π* ← π electronic excitation and of π ionization on conformation and barrier height are very similar to those observed earlier in meta-fluorotoluene by Ito and co-workers. The cation conformation can be understood simply in terms of ionization from a particular Huckel π molecular orbital which is oriented to have pseudo-C2v symmetry with respect to the axis bisecting the methyl and halogen substituents. This places the methyl rotor between two ring CC bonds of unequal bond order, which in turn causes the strong conformational preference in D0, analogous to that in 2-methylpropene. Evidently fluorine and chlorine act equivalently as weak π donors for purposes of orienting the Huckel orbitals of the cation.
Mechanism of Action of Retinyl Compounds on Wound Healing II: Effect of Active Retinyl Derivatives on Granuloma Formation

Abstract The naturally occurring retinyl derivatives that promote wound healing as measured by their effects on tensile strength of healing wounds also stimulate granuloma formation induced by cotton pellets.The hexosamine and hydroxyproline contents in the granuloma affected by retinyl derivatives are also increased.The mechanisms of action of retinyl derivation on wound healing are discussed.
Does Organizational Form Impact Pricing Asymmetry? Evidence from Nonprofit Financial Institutions

Why output prices tend to rise faster in response to input cost increases than they fall in response to input cost decreases is a hotly debated issue in modern economics. In this article, I contribute to this asymmetric pricing debate by expanding the domain of organizational forms where this question has been investigated. More specifically, previous research has focused on for-profit firms. I expand the investigation by focusing on nonprofit organizations. Credit unions are the nonprofit organization used in my analysis. Credit unions provide essentially identical types of consumer financial services and products as commercial banks but do so from a very different not-for-profit orientation. However, in this study, I document similar asymmetric rate-setting behavior by credit unions. This suggests that pricing asymmetry is likely to be much more widespread, as it relates to nonprofit institutions as well as those in the for-profit sector.
Digital optical logic using optically switched directional couplers

A novel optical logic gate with all-optical data signals is described. Control circuitry converts 100 MHz, −25dBm square-wave optical pulses at λ = 1.3/rai into electrical signals sufficient to switch the exchange state of LiNbO3 2 × 2 directional couplers in order to route similar optical pulses. Such optically-controlled directional couplers function as three-input, two-output logically complete gates for digital optical logic. Several digital optical circuits using these gates have been constructed and demonstrated.
Lead and strontium isotopes in rocks of the Absaroka volcanic field, Wyoming

The Absaroka volcanic field is comprised of predominant andesitic volcaniclastic rocks and less abundant potassium-rich mafic lavas (shoshonites and absarokites). Strontium and lead isotopic variations preclude a simple derivation from an isotopically uniform source: Sr87/Sr86, 0.7042 to 0.7090; Pb206/Pb204, 16.31 to 17.30; Pb208/Pb204, 36.82 to 37.64. We postulate that these rocks were derived from a lower crust or upper mantle which underwent a preferential loss of uranium relative to lead approximately 2800±200 m.y. ago. Variations in lead and strontium isotopic compositions are thought to reflect small inhomogeneities in U/Pb and Rb/Sr ratios in the source.
Comparison of problem families in the clinic and at home

In daily practice, clinicians often behave as if what they see and hear in their offices is representative of behavior occurring in other environments. Yet, research on the generalizability of clinic observations to the home and other natural environments has been limited, and much of this research suffers from potentially serious methodological problems. Fifteen families with conduct problem children participated in a study comparing parent and child behaviors in both the clinic and the home. Spearman correlation coefficients indicated that there were high correlations for three of the four behavior categories tested, though, as expected, a repeated measures ANOVA indicated that there were significant differences in actual rate of behavior between settings. These significant correlations were obtained on parent's rate of reinforcement, parent's rate of punishment, and child's rate of compliance. Child's rate of deviant behavior was the only category in which a low correlation was obtained.
Algorithm for quantifying advanced carotid artery atherosclerosis in humans using MRI and active contours

A new algorithm for measuring carotid artery volumes and estimating atherosclerotic plaque volumes from MRI images has been developed and validated using pressure-perfusion-fixed cadaveric carotid arteries. Our method uses an active contour algorithm with the generalized gradient vector field force as the external force to localize the boundaries of the artery on each MRI cross-section. Plaque volume is estimated by an automated algorithm based on estimating the normal wall thickness for each branch of the carotid. Triplicate volume measurements were performed by a single observer on thirty-eight pairs of cadaveric carotid arteries. The coefficient of variance (COV) was used to quantify measurement reproducibility. Aggregate volumes were computed for nine contiguous slices bounding the carotid bifurcation. The median (mean +/- SD) COV for the 76 aggregate arterial volumes was 0.93% (1.47% +/- 1.52%) for the lumen volume, 0.95% (1.06% +/- 0.67%) for the total artery volume, and 4.69% (5.39% +/- 3.97%) for the plaque volume. These results indicate that our algorithm provides repeatable measures of arterial volumes and a repeatable estimate of plaque volume of cadaveric carotid specimens through analysis of MRI images. The algorithm also significantly decreases the amount of time necessary to generate these measurements.
A Case Study in Effectively Bridging the Business Skills Gap for the Information Technology Professional

A longitudinal study of information technology (IT) managers at a Fortune 200 company in the Southwest United States was conducted to assess the effectiveness of a training program at bridging the perceived business skills gap for IT employees. A needs assessment was carried out, resulting in a 4-module training program. The program was evaluated for its ability to meet specific business skills deficiencies. Student perceptions were measured both at the time each skill module was delivered and at the conclusion of the training program with an online survey of all participants. Based on these results, the authors propose business training for skills often lacking in technology professionals to bridge the gap between technical skills training and leadership training.
House fly breeding and associated parasitoids in decaying melon fields.

Cull cantaloupes and watermelons were a major breeding habitat for Musca domestica L. in the Palo Verde Valley, California. By mid-July the average pupal density on decayed watermelons ranged 13.2-79.4/melon over three years. Parasitization never exceeded three percent through the combined action of Spalangia endius Walker, S. cameroni Perkins and S. nigroaenea Curtis. These species and S. drosophilae Ashmead were reported for the first time from an otitid, Euxesta notata (Wiedemann), also in decaying melons. Destruction of breeding habitat by mechanically breaking cull melons appears to be the only practical solution to the house fly problem.
Invited: Millimeter wave integrated circuits

Recent applications of millimeter waves will be described. These include high data rate communications, low altitude radar, obstacle avoidance, imaging and fog penetration, radiometry and radiometric imaging. The state-of-the-art of solid-state devices from 10-300 GHz will also be discussed. To reduce costs, which are a significant problem, several approaches to millimeter wave ICs are presently being pursued and will be compared.
Expanding the scientific role of the Hubble Space Telescope Fine Guidance Sensors

Abstract The Fine Guidance Sensors of the Hubble Space Telescope were originally designed as the ultimate guidance component of the spacecraft's Pointing Control System. Partly because of these capabilities, their role was enlarged to serve as the principal astrometric instrument of the observatory. This paper discusses extensions of the scientific use of the Fine Guidance System beyond traditional positional and double star astronomy (position and brightness to include color temperature, angular size, and limb darkening for single stars; magnitude difference, total brightness, separation, and position angle to also include color temperatures and angular diameters for double stars) to analogous attributes for non-stellar sources such as active galactic nuclei, quasars, supernovae remnants, multiple nuclei galaxies, and so on.
Gastric emptying of combined liquid-solid meals in healed duodenal ulcer

The gastric emptying rates of combined liquid and solid radioisotopically labeled meals in 47 healed duodenal ulcer subjects and 17 healthy control subjects are compared. No significant differences were found between the groups in emptying slopes and the emptying half-times or in the percent retention values at any of the counting intervals for either the liquid or solid meals. These results are compatible with the observation that the rapid gastric emptying in many patients with duodenal ulcer is associated with the disease and that healing results in a return to normal gastric emptying rates. However, since gastric emptying rates during active ulceration were not determined in our patients, a more definitive interpretation awaits a study comparing emptying rates obtained during and after healing of active ulceration in the same patient.
Textiles in Transition: Technology, Wages, and Industry Relocation in the U.S. Textile Industry, 1880-1930

Introduction Theories About the Relocation of the Textile Industry Description of Textile Production by Region Spindle Choice Mill Survival Probability of Mill Survival Evaluation of the Theories About Relocation Textile Wage Differentials and Equalization The Modern Textile Industry Conclusion Appendix A: Data Collection and Special Problems Appendix B: Overview of Textile Production Since 1800 Bibliography Index