cssi/SciSciGPT-SciSciNet huggingface dataset:
Hemoglobin and Myoglobin Stabilization by Heme-Fluoride Complexes

Under physiological conditions, hemoglobin (Hb) and myoglobin (Mb) are subject to autoxidation, leading to the formation of ferric heme proteins with weakened globular structures and resulting in the loss of the heme cofactor. To gain further insights into the role of the heme pocket in the stabilization of the heme-containing proteins (holo-Mb and holo-Hb), the relative stabilities of heme-bound fluoride complexes (Mb-F and Hb-F) were examined under denaturing conditions. The electronic spectra of the heme proteins were followed upon addition of guanidine hydrochloride (GuHCl) and under denaturation-induced acidification. In the presence of ~2M GuHCl, the heme-bound fluoride complexes are 27 – 46% more stable than ferric Hb and Mb. In addition, the affinity for fluoride under these denaturing conditions were determined. The dissociation constants ( K d ) for fluoride binding in Hb and Mb under 1.5 M GuHCl are slightly greater than the measured K d without GuHCl, which we attribute to the presence of molten-globular holo protein intermediates that are not favorable for fluoride binding. Under acidic denaturation, the acid-induced denaturing curves of Mb-F and Hb-F are -0.3 and -0.5 pH units shifted relative to ferric Hb and Mb, which show that the heme-bound fluoride proteins are more resistant to acid denaturation. This study shows that the measured fluoride affinities in the presence of GuHCl at various temperatures and the effects of pH on the K d can provide additional thermodynamic properties of Hb and Mb denaturation processes at low pH, where interactions between the heme pocket and the heme-bound fluoride are much stronger.
Flächengleiche Parallelogramme. Achsengleichung

Durch einen beliebigen Punkt P zwischen zwei Geraden g und l (Abb. 88), die sich unter einem Winkel 2 α im Punkte O schneiden, ziehen wir zwei Parallele PR und PQ zu g und l, wodurch ein Parallelogramm ORPQ entsteht. Wir fragen nun: auf welcher Kurve mus sich der Punkt P in diesem Winkelraume oder in dem seines Scheitelwinkels bewegen, damit er mit den beiden Geraden g und l und den dazu Parallelen, die durch ihn gezogen werden, Parallelogramme von konstantem Flacheninhalte bestimmt? Die zu bestimmende Kurve nennen wir Hyperbel. Um ihre Gleichung zu erhalten, wahlen wir O als Nullpunkt und die Halbierungslinie des Winkels 2 α als X-Achse. Der Punkt P habe in irgendeiner Stellung die Koordinaten x = OE und y = EP. Wir verlangern EP bis zum Punkte F auf g; dann ist das Dreieck PQF gleichschenklig und es ist $$PQ = QF = OR$$ . Open image in new window Abb. 88.
Fault tolerant shipboard MVDC architectures

Medium Voltage DC (MVDC) architectures are identified from the literature search that are suitable for a highly survivable 20kVdc shipboard Integrated Power System (IPS). “Breaker-based” architectures enable fast fault isolation through the use of Solid State Protective Device (SSPD) technology. “Breaker-less” architectures require based generator power converter and Solid State Transformer (SST) interfaces that can fold back outputs and coordinate with no load switches to isolate faults. Estimated size/weights and survivability of various “breaker-based” and “breaker-less topologies are compared. “Breaker-Less”, Current Source Converter (CSC) based architectures have the highest power density but at the cost of lower survivability. Expanding the role of galvanically isolating converters within the system (i.e. SSTs) increases power density and survivability.
Transfer Ribonucleic Acid Nucleotidyl-transferase Plays an Essential Role in the Normal Growth of Escherichia coli and in the Biosynthesis of Some Bacteriophage T4 Transfer Ribonucleic Acids

A series of cca mutants, deficient in the enzyme tRNA nucleotidyltransferase, have been used to show that this activity is essential for the normal growth of Escherichia coli and for the biosynthesis of some tRNAs. In some genetic backgrounds cca mutants grew at slow rates, and their generation time was related to the amount of residual tRNA nucleotidyltransferase remaining in the cells. Mutants with greater than 15 % of activity grew normally, indicating that the enzyme was usually present in large excess. One cca mutant, containing less than 5 % of normal activity, was used to select fast growing revertants. All revertants to normal growth simultaneously regained tRNA nucleotidyltransferase activity. Genetic studies indicated that the reversion occurred at the cca locus at a rate of 10-8 to 10-9. The importance of tRNA nucleotidyltransferase for tRNA biosynthesis was demonstrated in studies measuring the expression of bacteriophage T4 psu1+ and psu2+ tRNAs in the various cca mutants. Bacteriophage T4 psu1+- and psu2+-amber double mutants plated with very low efficiencies on cca mutants with low enzyme activity, and the plating efficiency increased with increasing levels of enzyme in the mutant cells.
Data-Flow and Multithreaded Architectures

The sections in this article are 1 Programming Languages for Data-Driven Execution 2 Data-Flow Architectures 3 Multithreaded Architectures 4 Summary
A barren landscape?—Metastable de Sitter vacua are nongeneric in string theory

We consider the generation of a nonperturbative superpotential in F-theory compactifications with flux. We derive a necessary condition for the generation of such a superpotential in F theory. For models with a single volume modulus, we show that the volume modulus is never stabilized by either Abelian instantons or gaugino condensation. We then comment on how our analysis extends to a larger class of compactifications. From our results, it appears that among large volume string compactifications, metastable de Sitter vacua (should any exist) are nongeneric.
Exchange Rates of Creatine Kinase Metabolites: Feasibility of Imaging Creatine by Chemical Exchange Saturation Transfer MRI

Creatine (Cr), phosphocreatine (PCr) and adenosine-5-triphosphate (ATP) are major metabolites of the enzyme creatine kinase (CK). The exchange rate of amine protons of CK metabolites at physiological conditions has been limited. In the current study, the exchange rate and logarithmic dissociation constant (pKa) of amine protons of CK metabolites were calculated. Further, the chemical exchange saturation transfer effect (CEST) of amine protons of CK metabolites with bulk water was explored. At physiological temperature and pH, the exchange rate of amine protons in Cr was found to be 7-8 times higher than PCr and ATP. A higher exchange rate in Cr was associated with lower pKa value, suggesting faster dissociation of its amine protons compared to PCr and ATP. CEST MR imaging of these metabolites in vitro in phantoms displayed predominant CEST contrast from Cr and negligible contribution from PCr and ATP with the saturation pulse parameters used in the current study. These results provide a new method to perform high-resolution proton imaging of Cr without contamination from PCr. Potential applications of these finding are discussed.
Management of hyperglycemia with the administration of intravenous exenatide to patients in the cardiac intensive care unit.

Objective: To evaluate the feasibility, effectiveness, and safety of intravenous exenatide to control hyperglycemia in the cardiac intensive care unit (CICU).Methods: A prospective, single-center, ...
Electroporation-mediated gene transfer in cardiac tissue

Delivery of genes or macromolecules to cardiovascular tissues provides new therapeutic opportunities for the treatment of many acquired and inherited diseases. To investigate electroporation as a delivery method in cardiac tissue, embryonic chick hearts were studied for uptake of propidium iodide (PI) or DNA encoding either green fluorescent protein (GFP) or luciferase following electrical shock. PI uptake increased monotonically from 6% of heart tissue after 3 shocks to 77% with 12 shocks. GFP and luciferase expression varied in proportion to shock number, with detectable levels in all electrically treated hearts. Thus, electroporation promotes uptake of PI and DNA in cardiac tissue, suggesting further application of this method for therapeutic genes.
Elastic constants of B-A1 composites by ultrasonic velocity measurements

The complete orthotropic elastic-stiffness matrix of unidirectional, Borsic-filament-reinforced aluminum composites was experimentally evaluated for three different volume fractions by ultrasonic velocity measurements on thin plates. Longitudinal- and shear-velocity measurements were made in appropriate symmetry directions by direct contact or liquid-immersion techniques. The elastic constants determined by this pulsed through-transmission method were in agreement with micromechanical theories based on the properties of the constituent materials. Agreement was also found between engineering constants determined by mechanical testing and those calculated from the ultrasonic data. Finally, measurement of the ultrasonic-wave velocity has also been shown to be a rapid nondestructive-test method for determining filament-volume fraction in a fabricated part.
Architecture of the γδ Resolvase Synaptosome

Abstract γδ resolvase catalyzes recombination within a complex nucleoprotein structure containing at least 12 resolvase subunits bound to two 114 bp res sites. The 2,3′ interaction between resolvase dimers is essential for synapsis and recombination. Using oriented resolvase heterodimers, we have identified half sites of res that must be occupied by a 2,3′-proficient protomer. For synapsis, only four of the eight subunits bound to sites II and III, those at II-L and III-L, require a 2,3′-proficient interface. This 2,3′ interaction, apparently between protomers bound to adjacent sites, may nucleate assembly of the core synaptic complex. For recombination, 2,3′-proficient subunits are also required at sites I-R and III-R, suggesting an important communication between the crossover site and the core of the synapse.
Characterization of humic acid size fractions by SEC and MALS

Latahco silt-loam humic acid was separated on a preparatory scale by size exclusion chromatography (SEC) on a gravity-fed Sepharose column. Four fractions from this separation were collected and further analyzed, along with whole humic acid, by high-performance SEC coupled with a multi-angle light scattering (MALS) detector. A detailed characterization of the radius of gyration across the elution profile of each fraction by MALS demonstrated that the preparative column generally separated the humic acid according to differences in molecular size. Furthermore, a comparison of elution profiles obtained on the whole humic acid with UV and refractive index detectors revealed the presence of a non-aromatic low molecular weight component.
Radiation Incident on Tilted Collectors

Abstract For solar energy system design purposes, observations of solar radiation on a horizontal surface must be converted to values on a tilted energy collector. An empirical conversion relationship, introduced by Liu and Jordan (1960) and based on short-term data for a single station, has been widely adopted throughout the nation. The spatial variations of the coefficients of this relationship and their stability with record length are investigated using the SOLMET radiation data for four stations in the southeast United States centered on North Carolina. Minor variations in coefficients result from changes in record length, but the differences have little impact on the design or performance of a solar energy system. Similarly, minor variations occur between coastal and inland sites but are insufficient to alter system designs. Hence a single relationship is appropriate for the area investigated. These SOLMET results indicate a greater proportion of direct radiation for a given total horizontal radiati...
Automated analysis of Fourier images for semiconductor wafer monitoring

A method for automating the analysis of images generated from the Fourier imaging (FI) process is described. Fourier imaging is used to observe the evolving topography of wafers as they are being etched in a reactive ion etcher. The focus of the research described in this paper is the segmentation and analysis of images generated from FI. A brief overview of the theory of FI is presented. Segmentation of a Fourier image is done in three steps; local maxima detection, Fourier component extent identification, and boundary tracking. Quantification descriptions for each component are then generated from the segmented image. The algorithm presented demonstrates how it is possible to obtain subpixel resolution automatically in image analysis to collect data that may be used to compute critical dimensions of the microtopography of the wafer substrate.
RETINOIDS AND IMMUNOMODULATION SUCCEED AGAINST HUMAN PAPILLOMA VIRUS INDUCED NEOPLASIA....AT LEAST FOR NOW. 949

RETINOIDS AND IMMUNOMODULATION SUCCEED AGAINST HUMAN PAPILLOMA VIRUS INDUCED NEOPLASIA....AT LEAST FOR NOW. 949
Polymer-polymer interactions: An extension of maron's theory of nonelectrolytes

Abstract The Maron theory of nonelectrolytes has been extended to include ternary (polymer-polymer-solvent) systems. The effective volume correction term, e/e0, prominent in the original theory, is eliminated. The equations obtained, with this exception, are identical in form to those found in Maron's original theory.
Nylon Colored with Large Vat Dye Particles

The presence of relatively large particles of a vat dye in nylon has been found to give outstanding lightfastness. Nylon colored with large particles of "Ponsol" Red BN required exposures in the Fade-Ometer of more than 200 hrs. in order to obtain perceptible change in color. Ordinary dyeing procedures, in which extremely small particles of dye are deposited in the nylon fiber, lead to Fade-Ometer-fastness for this color of less than 10 hrs. There are indications that this phenomenon is characteristic of many members of the vat color class.
A comparison of short-term outcomes between laparoscopic supracervical and total hysterectomy.

Objective The purpose of this study was to compare perioperative outcome measures of laparoscopic supracervical (LSH) and total hysterectomies (TLH). Study Design This is a retrospective analysis of 1016 LSHs and TLHs at a tertiary medical center between November 1999 and August 2008 in a multivariate logistic regression model. Results Overall, the groups were similar. Most of the perioperative outcome measures did not differ statistically between the groups. However, the risk of serious complications was higher for TLH (5.8% vs 2.5%; odds ratio [OR], 2.72; 95% confidence interval [CI], 1.35–5.49). Specifically, urinary tract injury occurred more frequently in TLH (2.2% vs 0.5%; OR, 4.75; 95% CI, 1.21–18.56). Conversion to laparotomy was significantly more common in TLH (5.8% vs 4.1%; OR, 2.25; 95% CI, 1.20–4.22). Conclusion In this largest comparison, short-term morbidity of TLH and LSH is overall similar. TLH presents a clinically small, but statistically significant, increased risk of urinary tract injury and conversion to laparotomy.
Increase in intracellular free calcium concentration of Limulus photoreceptors caused by a metabolic inhibitor.

Using a calcium indicator dye (arsenazo III), we detected a reversible rise in [Ca2−]i to about 2 mM in Limulus ventral photoreceptors when the cells were poisoned with the metabolic inhibitor DNP. Our results provide direct evidence for the hypothesis linking the action of metabolic inhibitors to an increase in [Ca2−]i in invertebrate photoreceptors.
INFLUENCE OF THERAPIST SKILLS ON CLIENT PERCEPTIONS OF MARRIAGE AND FAMILY THERAPY OUTCOME: IMPLICATIONS FOR SUPERVISION

Clients seen in two marriage and family therapy training clinics were surveyed regarding treatment outcome. They rated their therapist's skill level on several therapist variables including “experience,”“confident,”“concerned,” how well the treatment used seemed to “fit” their view of the problem and if the therapist seemed to “know how to deal” with their concerns. The variable of “fit” of treatment accounted for 35% of the variance in the client's perception of treatment outcome. “Concerned,”“fit,“ and “knew how to deal” accounted for 36% of the variance in overall rating of the therapist. Suggestions for using these results in supervision of beginning therapists are given.
Functional evaluation following microvascular oromandibular reconstruction of the oral cancer patient: A comparative study of reconstructed and nonreconstructed patients

Over the past decade, the use of free flap transfers in head and neck surgery has led to remarkable advances in the reliability and the ultimate results of oromandibular reconstruction. Stable and retentive dental restorations have been achieved using enosseous implants placed directly into the vascularized bone flaps. However, the functional assessment of patients who underwent primary mandibular reconstruction with these techniques has not been previously reported. A group of 10 reconstructed and 10 nonreconstructed segmental hemimandibulectomy patients were compared using a battery of tests to assess their overall well-being, cosmesis, deglutition, oral competence, speech, length of hospitalization, and dental rehabilitation. In addition, objective measures of the masticatory apparatus (interincisal opening, bite force, chewing performance, and chewing stroke) were used to compare these two groups as well as normal healthy subjects and edentulous patients restored with conventional and implant-borne dentures. The results show a clear advantage for the reconstructed patients in almost all categories. Persistent problems and future directions in oromandibular reconstruction are discussed.
In search of polar warming

Greenhouse warming, although predicted to become especially pronounced in the polar regions, will be obscured there by the short-lived anomalies that are characteristic of polar climates. To detect a warming it then becomes necessary to examine and compare statistical parameters of such quasi-steady interludes. A new “change index (CI)” is proposed and used to demonstrate that a warming at four Alaskan airfields, reported by Bowling (1991), represented a distinct change from the temperature mean and/or variance of the preceding few years, and was followed by a slightly cooler regime that has persisted through 1994.
Raman Spectrum of Crystalline Benzil

The Raman spectrum of the optically active organic crystal benzil, ${\mathrm{C}}_{6}$${\mathrm{H}}_{5}$COCO${\mathrm{C}}_{6}$${\mathrm{H}}_{5}$, belonging to the point group ${D}_{3}$, is studied with the 6328 \AA{} radiation from a He-Ne laser as the exciting radiation. From the correlation of the observed spectrum, consisting of 18 lines, with that of the melt and of benzene, it is concluded that most of the prominent lines with shifts g 100 ${\mathrm{cm}}^{\ensuremath{-}1}$ originate from the internal vibrations of the benzil molecule. The polarization of the Raman lines is studied to classify the normal modes which give rise to them into either the totally symmetric (${A}_{1}$) or the doubly degenerate ($E$) Raman-active vibrations of the ${D}_{3}$ point group. The intensity variation of several Raman lines for right-angle scattering and plane-polarized radiation incident along the optic axis is studied as a function of the angle $\ensuremath{\theta}$ between the electric vector of the incident light and the normal to the scattering plane. The intensity of the ${A}_{1}$ vibrations exhibits oscillations as $\ensuremath{\theta}$ is varied externally, whereas the intensity of the $E$ vibrations remains constant as a function of $\ensuremath{\theta}$. The relative intensities of the various Raman-active lines originating from the coupling of specific benzene-ring vibrations in the molecule and the crystal are calculated in terms of the orientation of the benzil molecules in the crystal, and are compared with the experimentally observed polarization characteristics of such lines.
High strength low carbon sheet steel by thermomechanical treatment:II. Microstructure

In a previous paper, the thermomechanical treatment concept for producing high strength stamped parts from a thermal-mechanically treated low carbon steel was described. In this paper, the microstructural changes occurring during both the processing and forming operations are detailed and the relation between properties and microstructure is discussed.
Patellofemoral instability in athletes: treatment via modified Fulkerson osteotomy and lateral release.

BackgroundSurgical treatment of patellofemoral instability can successfully diminish episodes of subluxation and dislocation, as well as symptoms of pain and instability.HypothesisSurgical treatment of lateral patellar instability in a strictly athletic population will facilitate return to sports.Study DesignCase series; Level of evidence, 4.MethodsFrom 1999 to 2004, 41 Fulkerson osteotomies combined with an arthroscopic lateral release were performed in 34 athletes for patellofemoral instability. Three patients were lost to follow-up. All patients participated in sports at least 3 times per week in at least one sport for 4 months of the year. There were 4 male and 30 female patients; 7 patients underwent bilateral, staged procedures. There were 14 high school, 12 collegiate, and 8 recreational athletes. Results were obtained by an independent examiner.ResultsThe mean age was 20.05 years (range, 14-54 years) with a mean follow-up of 46 months (range, 22-71 months). Patients averaged 1.3 dislocations befor...
The Significance of the Aesthetic in Postmodern Architectural Theory

Recent postmodern suspicion of truth, objectivity, and rationality has radically transformed our understanding of architecture and its relationship to politics. In this paper, I draw upon Hilary Putnam (1981), Nelson Goodman (1968), and Satya Mohanty (1997), who propose a sophisticated account of objectivity by reexamining the “hard” sciences, and by interpreting them as complex social practices. Building upon these writers, I argue that our subjective experiences of architecture are rational. As an alternative to both modern essentialism and postmodern skepticism, this paper defends a theory of objectivity that explains the relationship of architecture to political power without abandoning rational thought.
The Effects of Syntactic Complexity on Advertising Persuasiveness

Three experiments investigated the effects of syntactic complexity on the persuasiveness of advertising. Experiment 1 showed that, in a broadcast advertising context, syntactic complexity affects recall and recognition but not the persuasiveness of the advertising. However, Experiment 2 indicated that, in a print context, persuasiveness of an advertisement is affected by syntactic complexity. Finally, Experiment 3 demonstrated that motivation to process information interacts with syntactic complexity to determine the persuasiveness of print advertising. These results imply that the impact of syntactic complexity on advertising effectiveness is more complicated than previously thought.
Hydrodynamic mobility of chiral colloidal aggregates.

A recent advance in colloidal technology [Zerrouki et al., Nature (London) 455, 380 (2008)] uses magnetic aggregation to enable the formation of micron-scale particle clusters with helical symmetry. The basic building blocks of these aggregates are doublets composed of two micron-scale beads of different radii bonded together by a magnetic cement. Such self-assembled structures offer potential for controllable transport and separation in a low Reynolds number environment using externally applied magnetic or electric fields. Establishing the hydrodynamic properties of the aggregates, in particular the coupling between rotation and translation afforded by the cluster geometry, is an essential initial step toward the design of microfluidic devices employing these aggregates. To quantify this coupling, we first determine parametrized expressions that describe the positions of the beads in an aggregate as a function of size ratio of the two beads composing the doublets. With the geometry of the structure known, we perform hydrodynamic calculations to ascertain entries of the mobility matrix for the aggregate and establish the relationship between the applied torque about the helical axis and translations parallel to this direction. We find that for larger values of the particle radius ratio the coupling between rotations and translations changes sign as the number of doublets in the aggregate increases. This feature indicates that the clusters possess a more complex superhelical structure.
The impact of office neck ultrasonography on reducing unnecessary thyroid surgery in patients undergoing parathyroidectomy

Background: Some have suggested that thyroid disease is even more prevalent among patients with hyperparathyroidism (HPT) than in the general population. We sought to define the incidence and optim...
Merger policy greatly simplified: Building on keyes

This comment urges a recognition of the fact that the main goal of antitrust, as revealed in a century of consequences, is not economic efficiency or consumer protection but the dispersion of power and decision-making in the business world. Building on Lucile S. Keyes' proposal for improving merger guidelines, it argues that the “true” aims of merger policy can be more efficiently pursued by disallowing all mergers involving very large firms that cannot be justified on efficiency grounds and ignoring mergers involving all other firms.
Lipids and lipoprotein ratios: Contribution to carotid intima media thickness in adolescents and young adults with type 2 diabetes mellitus

Background Dyslipidemia is common among adolescents with type 2 diabetes (T2D). Objective To assess whether the lipoprotein ratios of low-density lipoprotein (LDL) cholesterol/high-density lipoprotein (HDL) cholesterol or triglycerides/HDL or non-HDL cholesterol are more useful than the traditional lipid panel to predict increased arterial thickness in adolescents and young adults with T2D. Methods We evaluated 244 adolescents and young adults with T2D in a cross-sectional study (mean age 18 years; 56% African American; 65% female). Demographics, anthropometrics, and laboratory data were collected. Arterial thickness was assessed with carotid intima media thickness (IMT). Bivariate correlations and general linear models were used to determine the independent contributions of the various lipid parameters to carotid IMT. Results Bivariate correlations showed LDL/HDL ratio was the strongest predictor of carotid IMT ( P z score, and hemoglobin A 1c . Together these cardiovascular risk factors explained Conclusions HDL cholesterol is the only lipid to independently associate with carotid IMT. Lipoprotein ratios and non-HDL did not provide additional information. The low variance in carotid IMT explained by traditional risk factors suggests nontraditional risk factors may be important to assess to better understand the contributors to early-stage atherosclerosis in adolescents and young adults with T2D.
Late Quaternary paleoecology and paleoclimatology of the Ross Sea: The diatom record

Abstract Factor analysis of marine-diatom census data from five Ross Sea piston cores resolved four floral assemblages similar to floral assemblages in Ross Sea core-top samples. All cores examined have three distinct lithologic units. The lowermost, Unit B, is interpreted as till deposited under grounded ice during the last expansion of the West Antarctic Ice Sheet. Unit B is characterized by a diatom flora of reworked species with widely differing stratigraphic ranges. A Transition Zone between Unit B and Unit A consists of well-sorted, sandy sediments with a diatom flora dominated by Eucampia balaustium . This Transition Zone was probably deposited under a regime of strong bottom currents immediately following retreat of the grounding line past each core location. The uppermost sediment, Unit A, represents a return to marine conditions. In core EL32-8, from the northwestern Ross Sea, Unit A is 152 cm thick and probably contains a record of Holocene climatic fluctuations. Diatom floras in this core indicate that, immediately following retreat of the grounded ice sheet, the sea surface was somewhat warmer than today during summers. Diatom floras in the uppermost 72 cm of Unit A in EL32-8 and in Unit A in all of the remaining cores indicate conditions similar to those of today. This paleoclimatic reconstruction appears to support the contention of some glacial geologists that grounded ice extended to the continental shelf margin at the last glacial maximum.
Complexly zoned chromium‐aluminum spinel found in situ in the Allende meteorite

— In addition to the Mg-, Al-, 16O-rich spinels that are known to occur in refractory inclusions, the Murchison meteorite contains Cr-rich, 16O-poor spinels, most of whose sources are unknown because they are rarely found in situ. Here we report the in situ occurrence in Allende of Cr-rich spinels, found in 13 chondrules and 4 “olivine-rich objects”. The Allende spinels exhibit major and minor element contents, isotopic compositions, and zoning of Cr2O3 contents like those of the Cr-spinels from Murchison. Some chondrules contain patchy-zoned spinel (Simon et al., 1994), which suggests that such grains did not form by sintering but perhaps by formation of overgrowths on relic grains. Unlike the olivine-rich objects, phases in all three chondrules that were analyzed by ion microprobe have uniform, near-normal O-isotopic compositions. One olivine-rich object, ALSP1, has a huge (1 mm) fragment of chevron-zoned spinel. This spinel has near-normal O-isotopic compositions that are quite distinct from those of adjacent forsteritic olivine, which are relatively 16O-rich and plot on the calcium-aluminum-inclusion (CAI) line, like some isolated forsterite grains found in Allende. The spinel and olivine in this object are therefore not genetically related to each other. Another olivine-rich object, ALSP11A, contains a rectangular, 150 ×s 100 μm, homogeneous spinel grain with 50 wt% Cr2O3 and 23 wt% FeO in a vuggy aggregate of finer-grained (5–90 μm), FeO-rich (Fo47–55) olivine. The magnesian core of one olivine grain has a somewhat 16O-rich isotopic composition like that of the large spinel, whereas the FeO-rich olivine is relatively 16O-poor. The composition of the spinel in ALSP11A plots on the CAI line, the first Cr-rich spinel found to do so. Chevron-zoned spinel has not been observed in chondrules, and it is unlikely that either ALSP1 or ALSP11A were ever molten. Calculations show that a spinel with the composition of that in ALSP1 can condense at 1780 K at a Ptot of 10−3 atm and a dust/gas ratio of 100 relative to solar. The Cr-rich spinel in ALSP11A could condense at ∼1420 K, but this would require a dust/gas enrichment of 1000 relative to solar. The data presented here confirm that, as in Murchison, the coarse Cr-rich spinels in Allende are relatively 16O-depleted and are isotopically distinct from the 16O-enriched MgAl2O4 from CAIs. Sample ALSP11A may represent a third population, one that is Cr-rich and plots on the CAI line. That the O-isotopic composition of ALSP1 is like those of Cr-rich spinels from chondrules indicates that O-isotopic compositions cannot be used to distinguish whether grains from such unequilibrated objects are condensates or are fragments from a previous generation of chondrules.
Pretreatment and midtreatment measurement of oxygen tension levels in head and neck cancers.

Objective: Considerable evidence exists to suggest that tumor hypoxia results in radioresistance. Historically, it has been difficult to assess tumor oxygen tension levels reliably. These levels can now be assessed in head and neck malignancies using the Eppendorf pO 2 histograph, which uses a fine-needle electrode and a computerized micromanipulator. This technology was used to compare the pretreatment tumor oxygen tension level in lymph node metastases of patients with head and neck cancer to measurements taken during nonsurgical treatment after a partial response had been achieved. Study Design: Prospective study. Methods: Oxygen tension levels were measured in the cervical lymph nodes of 10 patients with biopsy-proven head and neck squamous cell carcinoma and cervical metastases who were being treated with nonsurgical management. These levels were obtained using the Eppendorf pO 2 histograph system. Measurements were taken before the start of treatment and were repeated when the size of the cervical metastatic node had decreased by 50%. Normal subcutaneous tissue was measured during the same session. The mean and median pO 2 levels, as well as the percentage of measurements with pO 2 less than 5 mm Hg were determined. Results: A mean of 72.6 measurements per session was taken from each lymph node. The median tumor pO 2 measurement fell from a mean (±SD) of 13.9 ± 8.0 mm Hg to 7.3 ± 9.9 mm Hg. Even more dramatic, however, was the substantial increase in the percentage of values less than 5 mm Hg, a rise from 29% to 52%. Conclusions: While there is variability both in the pretreatment oxygenation of head and neck cervical metastases and in the change in tumor oxygen tension during treatment, there appears to be a decrease in the overall oxygenation of the tumors. The dramatic increase in very low oxygen measurements may reflect selective survival of radioresistant or chemoresistant hypoxic tumor cells. Cells at the very low level would be expected to be radiobiologically hypoxic (resistant to radiation-induced cell kill).
A sensitive spectrophotometric method for detection of l-fucose

Small amounts of free l-fucose were estimated by incubating it with purified pig liver fucose dehydrogenase at pH 8.1 in the presence of NAD+ and measuring the formation of NADH spectrophotometrically at 340 nm. The reaction was linear over the range 0.01–0.10 μmol of l-fucose. The method was used to compare the ability of both highly purified α-l-fucosidase and crude tissue homogenates to hydrolyze fuco-oligosaccharides of known structure. The inability of tissue extracts from patients with fucosidosis (Type I) to hydrolyze a wide variety of fuco-oligosaccharides was clearly demonstrated.
On the effects of the radial basis function scale parameter on the numerical solution of partial differential equations

Radial Basis Functions have received significant attention in the scientific literature over the past several years. Specifically, they have been investigated extensively in the field of neural networks. They have been shown to have very good interpolation qualities and this property has led to the research presented in this letter. In this letter, radial basis functions are used in a meshless method using collocation to solve a simple electromagnetics problem; the main intent of this letter is to investigate the effects of the variation of the scale parameter present in the radial basis function. In particular, we will see its effects upon both the condition number of the resulting matrix and the solution accuracy. Some of the advantages and disadvantages of the proposed method will be discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1520–1524, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24347
Postoperative respiratory failure secondary to Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) occurs frequently in individuals infected with the HIV virus. Malignancy, immunosuppressive drugs, and congenital immune deficiency may be associated with PCP. We describe a patient with stage 1 testicular carcinoma who developed hypoxemic respiratory failure two days after retroperitoneal lymph node dissection. Pneumocystis carinii organisms were demonstrated by catheter lavage samples and confirmed on bronchoalveolar lavage. Testing for HIV antibody by ELISA and the Western blot test was negative; HIV viral culture and polymerase chain reaction were also negative. Pneumocystis carinii pneumonia is unusual in localized surgically cured malignancies without obvious immunodeficiency and, to our knowledge, has not been described as a cause of postoperative respiratory failure.
Implementation and incorporation of liver 3D surface renderings into interactive image-guided hepatic surgery

ABSTRACT In interactive, image-guided surgery, current physical space position in the operating room is displayed on various sets ofmedical images used for surgical navigation. One useful image display format for image-guided hepatic surgery is liversurface renderings. Deep-seated tumors within the liver can be projected onto the surface of these renderings and providepertinent information concerning the location and size of metastatic liver tumors. Techniques have been developed by ourgroup to create hepatic surface renderings. An independently implemented variation ofthe marching cubes algorithm is usedon segmented livers to create a triangulated surface, which is displayed using OpenGL, a 3-D graphics and modelingsoftware library. Tumors are segmented separately from the liver so that their colors differ from that of the liver surface.The liver is then rendered slightly transparent so that tumors can be seen within liver and aid surgeons in preoperativeplanning. The graphical software is also bundled into a dynamic linked library (DLL) and slaved with ORION, our WindowsNT based image-guided surgical system. We have tested our graphics DLL on a liver phantom embedded with "tumors". Asurface-based registration algorithm was used to map current surgical position onto a transparent phantom rendering thatindicates tumor location. The rendering view is updated as surgical position is changed. For minimally invasive procedures,we will use the direct linear transformation and the same surface-based registration technique to map rendered tumorsdirectly onto an endoscopic image. This will be especially useful in localizing deep-seated tumors for ablation and resectionprocedures.Keywords: surface renderings, image-guided surgery, OpenGL, liver surgery
Equilibrium and Nonequilibrium Statistical Thermodynamical Approaches to Modeling Spatial Interaction Dynamics

Spatial interaction modeling can be embedded in the framework of statistical thermodynamics. This has been shown in part by Wilson and by Erlander, in particular. However, to complete the embedding, it is necessary to ask the dynamic question of how a migratory population evolves over time from one (observed) distribution at time t0 to another (observed) distribution at time t1, rather than just the question of how many people who started in one area at t0 ended in another at t1—with no regard to the intermediate locations of the migrants. The manner in which such evolutionary processes are addressed in the context of equilibrium and nonequilibrium thermodynamics serves as a basis for extending the spatial interaction model of human movement.
The flight mechanism of the pigeon Columbia livia during take-off

High-speed film analysis of the mechanism of take-off of a pigeon ascending nearly vertically reveals the pattern of movements of the wing segments and the bones within them during each of the five phases of the wingbeat cycle. Differences in the type and extent of wing movements between the upstroke and downstroke portions of the first and successive wingbeat cycles are explained with reference to the upward vertical jump made during the first wingbeat cycle. The presence during pigeon take-off of a non-steady state pattern of airfoil action similar to that seen in some insects at the beginning of the downstroke was verified.
Drug Interactions I: Detection of Inorganic Nitrite in Organic Nitrate Esters Under Acidic Conditions Simulating the Human Stomach

Both unformulated (bulk) and formulated (drugs) organic nitrate esters (isosorbide dinitrate, nitroglycerin, and pentaerythritol tetranitrate) were studied in the presence and absence of hydrochloric acid to determine if they could be sources of nitrite (and therefore lead to nitrosamine formation) under acidic conditions similar to those found in the stomach. The presence and generation of nitrite ion was detected by a modification of the Griess reaction. Bulk isosorbide dinitrate and nitroglycerin were found to be contaminated with 13.8-121.4 mumoles of inorganic nitrite per mole of nitrate ester. In addition, in the presence of hydrochloric acid, these preparations generated 0.52-1.18 mumoles of inorganic nitrite/mole of nitrate ester/min. Unformulated nitroglycerin generated nitrite at a rate roughly twice that of isosorbide dinitrate. In contrast, no evidence for nitrite contamination or generation by pentaerythritol tetranitrate was found. Tablets and capsules of isosorbide dinitrate contained approximately 27-216 mumoles of nitrite/mole of nitrate ester and, in the presence of hydrochloric acid, generated an average of 0.55 mumole nitrite/min. For isosorbide dinitrate, this rate was similar for bulk and formulated drug. In comparison to isosorbide dinitrate, the amount of nitrite initially present in tablets and capsules of nitroglycerin varied more widely (approximately 25-2290 mumoles nitrite/mole of nitrate ester), and in this case nitrite was generated at higher rates than unformulated drug averaging approximately 4.7 mumoles nitrite/mole of nitrate ester/min. Contrary to a literature report, we found that nitrate ion is not reduced to nitrite by hydrochloric acid (pH 1-3).(ABSTRACT TRUNCATED AT 250 WORDS)
Aposematic coloration enhances chemosensory recognition of noxious prey in the garter snakeThamnophis radix

Abstract Considerable recent research has suggested that predators learn to avoid noxious or unpalatable prey more rapidly if those prey have conspicuous (aposematic) colour patterns. However, the precise psychological mechanisms by which predators associate conspicuous coloration with unpalatability remain poorly understood. In this study, the relative importance of visual and chemosensory information in learned aversions to noxious prey was examined by offering garter snakes two different types of prey (fish and earthworms) on forceps with varying colour patterns. Experimental subjects received injections of LiCl to induce illness immediately following the consumption of fish offered on either aposematic (yellow-and-black) or non-aposematic (green) forceps. Following their induced illness, snakes within both the aposematic and non-aposematic treatment groups showed significant aversions to fish, and avoided fish regardless of the colour of the forceps with which fish were offered. However, the aversion to fish was markedly stronger among snakes in the aposematic treatment group than in the non-aposematic group. These results indicate that aposematic coloration enhances chemosensory learning; aversions to unpalatable prey are formed more readily if the prey is conspicuously coloured, even though recognition of unpalatable prey depends on the prey's chemosensory characteristics rather than its coloration. Future responses to unpalatable prey are therefore influenced by an unexpectedly complex interaction of visual and chemosensory information acquired during the initial encounter.
The geography of nonemployment income

Abstract Income from sources not related to current employment accounted for 31.6% of total personal income in the United States during 1986. Areas where non-employment income makes up a disproportionally large share of personal income include amenity-laden retirement regions such as peninsular Florida and the Texas hill country; regions where farmland leasing is common, such as the Great Plains; and such places as Appalachia where low income occasions various forms of income subsidies. The variables most strongly associated with concentrations of nonemployment income are the percentage of older population, per capita income and percent rural farm population. Results have both theoretical and practical implications for economic base studies and migration.
A new approach for studying fast biological reactions involving nitric oxide: generation of NO using photolabile ruthenium and manganese NO donors

Nitric oxide (NO) is recognized as one of the major players in various biochemical processes, including blood pressure, neurotransmission and immune responses. However, experimental studies involving NO are often limited by difficulties associated with the use of NO gas, including its toxicity and precise control over NO concentration. Moreover, the reactions of NO with biological molecules, which frequently occur on time scales of microseconds or faster, are limited by the millisecond time scale of conventional stopped-flow techniques. Here we present a new approach for studying rapid biological reactions involving NO. The method is based on designed ruthenium and manganese nitrosyls, [Ru(PaPy3)(NO)](BF4)2 and [Mn(PaPy3)(NO)](ClO4) (PaPy3H = N,N-bis(2-pyridylmethyl)amine-N-ethyl-2-pyridine-2-carboxamide), which upon photolysis produce NO on a fast time scale. The kinetics of the binding of the photogenerated NO to reduced cytochrome c oxidase (CcO) and myoglobin (Mb) was investigated using time-resolved optical absorption spectroscopy. The NO was found to bind to reduced CcO with an apparent lifetime of 77 micros using the [Mn(PaPy3)(NO)]+ complex; the corresponding rate is 10-20 times faster than can be detected by conventional stopped-flow methods. Second-order rate constants of approximately 1 x 10(8) M(-1) s(-1) and approximately 3 x 10(7) M(-1) s(-1) were determined for NO binding to reduced CcO and Mb, respectively. The generation of NO by photolysis of these complexes circumvents the rate limitation of stopped-flow techniques and offers a novel alternative to study other fast biological reactions involving NO.
Globular cluster evolution in M87 and fundamental plane ellipticals

The globular cluster population in M87 has decreased measurably through dynamical evolution caused by relaxation, binary heating and time-dependent tidal perturbation. For fundamental plane ellipticals in general, cluster populations evolve more rapidly in smaller galaxies because of the higher mass density. A simple evolutionary model reproduces the observed trend in specific frequency with luminosity for an initially constant relationship. Fits of theoretically evolved populations to M87 cluster data from McLaughlin et al. (1994) show the following: 1) dynamical effects drive evolution in the initial mass and space distributions and can account for the large core in the spatial profile as well as producing radial-dependence in the mass spectrum; 2) evolution reduces S_N by 50% within 16 kpc and 35% within 50 kpc, implying that S_N was initially 26 in this region. We estimate that 15% of the `missing' clusters lie below the detection threshold with mass less than 10^5 M_sun.
Scaling planar silicon devices

The generation-over-generation scaling of critical CMOS technology parameters is ultimately bound by nonscalable limitations, such as the thermal voltage and the elementary electronic charge. Sustained improvement in performance and density has required the introduction of new device structures and materials. Partially depleted SOI, a most recent MOSFET innovation, has extended VLSI performance while introducing unique idiosyncrasies. Fully depleted SOI is one logical extension of this device design direction. Gate dielectric tunneling, device self-heating, and single-event upsets present developers of these next-generation devices with new challenges. Strained silicon and high-permittivity gate dielectric are examples of new materials that will enable CMOS developers to continue to deliver device performance enhancements in the sub-100 nm regime.