cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis of the constancy of DNA sequences during development and evolution of the nematode Caenorhabditis elegans.

Abstract In order to test for the occurrence of rearrangements in DNA during development and to assess the rate of DNA divergence during evolution, we have compared restriction fragments derived from DNA from four sources: sperm cells and somatic tissues of one strain of the nematode Caenorhabditis elegans, somatic tissues of a second strain of the same species, and whole animals of a closely related species. Restriction fragments were detected by hybridizing radioactive cloned fragments to restriction digests that had been fractionated by size on agarose gels and transferred to nitrocellulose sheets. In this way, approximately 50 BamHI restriction fragments were visualized and compared. Fragments from sperm and somatic DNAs were found to be identical; 15% differed in size between the two strains. Little cross homology was found between the two species. We conclude that, if rearrangements occur in C. elegans DNA during development, they must affect fewer than a few percent of the restriction fragments or restriction sites. The difference found between the two strains and the two species is surprisingly great.
The effect of walking speed on muscle function and mechanical energetics

Modulating speed over a large range is important in walking, yet understanding how the neuromotor patterns adapt to the changing energetic demands of different speeds is not well understood. The purpose of this study was to identify functional and energetic adaptations in individual muscles in response to walking at faster steady-state speeds using muscle-actuated forward dynamics simulations. The simulation data were invariant with speed as to whether muscles contributed to trunk support, forward propulsion or leg swing. Trunk support (vertical acceleration) was provided primarily by the hip and knee extensors in early stance and the plantar flexors in late stance, while trunk propulsion (horizontal acceleration) was provided primarily by the soleus and rectus femoris in late stance, and these muscle contributions all systematically increased with speed. The results also highlighted the importance of initiating and controlling leg swing as there was a dramatic increase at the higher walking speeds in iliopsoas muscle work to accelerate the leg in pre- and early swing, and an increase in the biarticular hamstring muscle work to decelerate the leg in late swing. In addition, walking near self-selected speeds (1.2 m/s) improves the utilization of elastic energy storage and recovery in the uniarticular ankle plantar flexors and reduces negative fiber work, when compared to faster or slower speeds. These results provide important insight into the neuromotor mechanisms underlying speed regulation in walking and provide the foundation on which to investigate the influence of walking speed on various neuromotor measures of interest in pathological populations.
Star studded advertising: Is it worth the effort?

Demand for stars and celebrities to endorse products has increased so much that celebrity brokering has emerged. All types of products and services are vying for the use of stars. How effective are these stars? Is it worth the efforts? Is it worth the cost? There are opinions on both sides of the argument. To ascertain the effectiveness of star advertising, 1972 respondents were queried at random, and 411 were returned and analyzed. Celebrities were grouped by categories— entertainers, athletes, and invented product characters. Products were classified by durables, semi-durables, and consumables. Items such as celebrity-product associations for buyers and non-buyers, effectiveness of celebrity type, product type importance, credibility, and trustworthiness were studied.
Lyman-α Radiation Resulting From Ion Collisions with Molecular Gases

Cross sections for the emission of Lyman-$\ensuremath{\alpha}$ radiation resulting from ion---target-gas collisions have been measured for projectile energies between 1 and 25 keV. All combinations of ${\mathrm{H}}^{+}$, ${\mathrm{D}}^{+}$, $\mathrm{H}_{2}^{+}$, $\mathrm{D}_{2}^{+}$, and ${\mathrm{He}}^{+}$ projectiles on ${\mathrm{H}}_{2}$ and ${\mathrm{D}}_{2}$ targets as well as ${\mathrm{H}}^{+}$ and $\mathrm{H}_{2}^{+}$ on ${\mathrm{N}}_{2}$ have been studied. Although product excited H or D atoms which decay via the $2p\ensuremath{-}1s$ Lyman-$\ensuremath{\alpha}$-emitting transition may result from a variety of collision mechanisms, some interpretation has been possible using data from earlier experiments.
Ray Scattering by an Arbitrarily Oriented Spheroid .II. Transmission and Cross-Polarization Effects

Transmission of an arbitrarily polarized plane wave by an arbitrarily oriented spheroid in the short-wavelength limit is considered in the context of ray theory. The transmitted electric field is added to the diffracted plus reflected ray-theory electric field that was previously derived to obtain an approximation to the far-zone scattered intensity in the forward hemisphere. Two different types of cross-polarization effects are found. These are (a) a rotation of the polarization state of the transmitted rays from when they are referenced with respect to their entrance into the spheroid to when they are referenced with respect to their exit from it and (b) a rotation of the polarization state of the transmitted rays when they are referenced with respect to the polarization state of the diffracted plus reflected rays.
Rapid recurrence and malignant transformation of pilocytic astrocytoma in adult patients.

Pilocytic astrocytoma is a slow-growing, circumscribed glioma that most frequently occurs within the pediatric population. In general, surgical resection for pilocytic astrocytoma is thought to be curative with tumor recurrence or malignant transformation being relatively rare. However, there have been very few studies specifically looking at the prognosis for adult patients diagnosed with pilocytic astrocytoma. To evaluate the frequency of recurrence and malignant transformation of pilocytic astrocytoma in adults, we performed a retrospective analysis of all adult patients who underwent surgical resection for this tumor at our institution over a period of 10 years. In our cohort of 20 patients, there were 6 (30%) recurrences with four patients requiring repeat surgery due to symptomatic progression. Relatively rapid recurrences were noted with the median time to recurrence being 16.5 months. All recurrences occurred within 4 years of initial surgery while patients requiring repeat surgery presented within 17 months of initial surgery. Based on this study estimated rates of freedom from recurrence (FFR) at 12 and 24 months after initial surgery are 94 ± 5% and 76 ± 10%, respectively. A high rate of malignant transformation was observed in the patients that underwent repeat surgery with 75% (3/4) progressing to anaplastic astrocytoma on pathological examination. This study provides further evidence that the clinical course of a subset of adult patients with pilocytic astrocytoma will not be benign. The potential for rapid tumor recurrence and malignant transformation necessitates careful post-operative follow-up for adult patients with this tumor.
The Adam Smith Award Address, 2004

Much of what Adam Smith said in 1776 remains fresh today—particularly on the trade-off between “guns and butter.” It is safe to say, however, that he did not anticipate macroeconometric modeling for forecasting and policy analysis. From its beginnings in the 1940s, the standards and the needs of users of forecasts are becoming ever more demanding as the information flow becomes more bountiful. We have evolved from reliance on annual data to the availability of high-frequency data and the challenges of integrating the two into reliable, timely forecasting models. In extending modeling efforts to transition and newly developing countries, I have been pleasantly surprised at the availability of important data, making possible not only models for individual countries but for linking them to understand the impacts of global phenomena such as oil shocks and financial crises. In many of these countries, however, time series are short—making efficient use of high-frequency data even more important. Another promising area of investigation is integration of input-output and flow-of-funds analysis with income and product accounts for more realistic treatment of such issues as technological change and interest rates.
Left atrial volume measurement with magnetic resonance imaging: a comparison of biplane, short axis and long axis methods

Left atrial (LA) dilation is an important index in cardiovascular disease. The CMR volumetric short axis method is the reference imaging standard but has limited ability to define the mitral valve plane accurately. The biplane method is simpler and frequently employed in clinical settings. We hypothesized that long axis two chamber (2ch) imaging might better define left atrial boundaries.
Modulation of melanosome ultrastructure in cultured embryonic pigment cells

Melanosomes synthesized by embryonic chick retinal pigment cells in vitro are of a different size and shape than those made in ovo and in vivo. Ultrastructurally, the melanosomes made by cultured cells are small, spherical, contain an irregular internal matrix, and appear similar to the pheomelanosomes found in red hair and feathers. This modulation in melanosome ultrastructure in cultured retinal pigment cells does not appear to be caused by an irreversible change in differentiated capability but to a response of cells to the culture environment. Cells grown in embryo extract-free and serum-free defined media were found to synthesize melanosomes of normal size and shape in vitro, although at a much reduced number. The predominant melanosome type found was still the smaller, spherical variety. It appears that some still unknown factors in the culture environment have produced a shift to a different type of melanogenesis.
A New Method of Doping Pyrolytic Graphite Utilizing Laser Heating in the Presence of Organic Heteroatomic Vapors

When pyrolytic graphite is heated with a high-energy pulsed Nd:YAG laser in the presence of pyrrole or 3-methylthiophene vapors, the surface becomes doped with nitrogen or sulfur, respectively. The time frame of the intense heating is such that the lattice does not undergo any extensive rearrangement, and the methodology results in modification of the properties of the graphite by introducing donor or acceptor atoms into the array. The doped graphites are analyzed by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), X-ray diffraction (XRD), X-ray fluorescence microscopy (XFM), and/or scanning electron microscopy (SEM). XPS indicates chemical shifts in the carbon 1s energies for the nitrogen and sulfur doped samples. AES shows changes in the carbon KLL emission energies upon doping. Correlation of these shifts with the XRD allows definition of the chemical bonding present. Nitrogen is covalently bound to carbon at the domain edges and at trigonal sites, breaking the local aromatici...
Linking Angiotensin II to Nuclear Factor-κ Light Chain Enhancer of Activated B Cells–Induced Cardiovascular Damage: Bad CARMAs

See related article, pp 1032–1039 The capacity of agents that inhibit the renin–angiotensin system (RAS) to lower blood pressure and limit cardiac damage indicates that inappropriate RAS stimulation underlies the pathogenesis of hypertension and its associated complications. Although a key effector of the RAS, angiotensin II (Ang II), instigates hemodynamic injury to the heart by promoting blood pressure elevation, Ang II can also exacerbate end-organ damage independently of blood pressure by stimulating immune and inflammatory signaling cascades.1 One prominent inflammatory pathway responsive to angiotensin receptor ligation culminates in the translocation of nuclear factor-κ light chain enhancer of activated B cells (NF-κB) to the nucleus where it drives transcription of a broad array of inflammatory mediators.2 Accordingly, the activation of NF-κB signaling pathway by Ang II potentiates target-organ damage in hypertension.3 Nevertheless, the upstream mechanisms through which Ang II stimulates NF-κB in hypertension have awaited further investigation. In one paradigm of NF-κB activation, the CBM signalosome promotes ubiquitination of an IκB subunit that would otherwise sequester the rest of the NF-κB complex in the cytoplasm, allowing a heterodimer composed of NF-κB’s p50 and p65 subunits to translocate to the nucleus and direct transcription of inflammatory cytokines.4 In lymphocytes, the CBM signalosome includes caspase recruitment domain 11 (CARMA1), B cell lymphoma/leukemia 10 (Bcl10), and mucosa-associated lymphoid tissue lymphoma translocation protein 1. In nonimmune cells, CARMA3 substitutes for CARMA1 in the CBM signalosome, but either of these CARMAs must complex with Bcl10 to trigger the NF-κB inflammatory signaling cascade.5 Therefore, as …
Plasma electric microfields for differing electron and ion temperatures

Abstract A formalism is presented for the calculation of the low frequency electric microfield at a charged point in a plasma with differing electron- and ion-temperatures. The theory is based on the APEX approximation and reproduces the results of weak coupling theories but is also expected to be valid into the strong coupling regime. This formalism is computationally much simpler than previous two temperature microfield theories. The validity of the two temperature plasma model is also discussed along with the effect of this microfield on the first three members of the Lyman emission line series of hydrogenic aluminum.
Relationship Between Information Privacy Concerns and Computer Self-Efficacy

Individuals have two types of focus involving privacy and technology: a personâ€™s concerns with organizational practices towards the privacy of personal information (management focus), and the personâ€™s self-efficacy of computers (technology focus). People view management of personal information and information technology as unrelated issues. The authors hypothesize that there is no relationship between a personâ€™s concerns for information privacy (management focus) and his/her self-efficacy towards computers (technology focus). The purpose of this study was to investigate the relationship between computer self-efficacy, and concerns for personal information privacy.
A Highly Stable Porphyrinic Zirconium Metal–Organic Framework with shp-a Topology

Through a kinetically controlled synthetic process, we synthesized PCN-223, a new porphyrinic Zr-MOF constructed from the newly reported hexagonal prismatic 12-connected Zr6 cluster through an unusual disordered arrangement, giving rise to the first example of the shp-a network in MOFs. With its extremely high connectivity, PCN-223 shows high stability in aqueous solutions with a wide range of pH. Cationic PCN-223(Fe) formed by postsynthetic treatment is an excellent recyclable heterogeneous catalyst for the hetero-Diels–Alder reaction.
Implementations, comparisons, and an investigation of heuristic techniques for cone-beam tomography

A novel cone-beam reconstruction method was proposed in 1985. The first objective of the work reported here is to implement this reconstruction method. The second objective is to compare it with the method developed by Feldkamp et al. (1984). Although the resulting reconstruction was not perfect, the proposed method did eliminate the axial distortion associated with Feldkamp's method. A second cone-beam reconstruction method was proposed in 1987. Two major challenges arise when this method is implemented. One is to minimize the error that results from violating an assumed condition on the distribution of the cones. The second is to minimize the error that results from the convolution of a discontinuous function which is introduced to compensate for the redundancy in the data set. The third objective of the work reported here was to investigate several heuristic techniques to minimize these errors. Techniques were found that did mitigate these errors and using these techniques resulted in images that are more accurate than those resulting from the 1985 method.
Genetic Variation in the Texas Mouse, Peromyscus attwateri

Populations of Peromyscus attwateri from 12 sites in Arkansas were examined for patterns of genetic variation. Of 36 presumptive loci examined, 15 were polymorphic based on a 95% criterion. Individuals from localities in the Ozark Plateau physiographic region were more heterozygous than those from the Ouachita Mountains region. A high fixation-index ( F ST ) value indicated that populations have diverged approximately 14%; most of the genetic variation resided within sample localities, with slight differentiation (1%) between physiographic regions. However, there was greater differentiation within the Ouachita Mountains region than within the Ozark Plateau region. Overall, genetic differentiation primarily appears to be the result of drift, mutation, and founder effects in isolated populations.
Factors influencing densities of non‐indigenous species in the ballast water of ships arriving at ports in Puget Sound, Washington, United States

1. Oceanographic characteristics and the presence of international shipping in Puget Sound, Washington, USA contribute to its vulnerability to non-indigenous species (NIS) invasions. To evaluate NIS arriving in ballast water, zooplankton was sampled in 380 ballast tanks of ships after they entered Puget Sound. 2. Taxa were classified into a higher risk group of coastal organisms (including known NIS), and a lower risk group of largely oceanic species. Most ships reported conducting mid-ocean ballast water exchange (BWE). However, despite state regulations requiring BWE, and apparent compliance by ship operators, most sampled tanks from both transpacific and coastal routes had coastal zooplankton densities exceeding internationally proposed discharge standards. 3. BWE efficiency models and controlled before-and-after BWE experiments indicate that BWE consistently removes most coastal zooplankton. However, this study found that although the empty–refill method of BWE significantly reduced coastal plankton compared with un-exchanged tanks, the flow-through method did not, and in either case remaining coastal plankton densities presented appreciable risks of introducing NIS. 4. Densities of high risk taxa were consistently and significantly higher from US domestic trips dominated by tank ships carrying ballast water from California, and lower in samples from trans-Pacific trips dominated by container ships and bulk carriers with ballast from Asia. These findings are probably a result of the dense and diverse NIS assemblages present in California and other US west coast estuaries and the comparatively short transit times between them and Puget Sound. 5. While it appears that BWE can effectively replace NIS with less risky ocean species, new reporting, verification, and operational procedures may be necessary to enhance BWE efficacy. In the long-term, the introduction of ballast water treatment technologies may be required to significantly reduce the discharge of risky organisms from commercial ships if BWE practices do not become more effective. Copyright © 2008 John Wiley & Sons, Ltd.
Optimal structural synthesis, modeling, and control of micro-mechatronic systems

Abstract New advances in micro-machining, micro- and nano-scale motion structures and analog/digital ICs, provide enabling benefits and capabilities to design and manufacture micro-mechatronic systems (MMS). Critical issues are to improve power and thermal management, circuitry and actuator/sensor integration, and embedded electronically controlled micro-actuator/sensor assemblies. Very large-scale ICs and micromachining silicon, germanium, and gallium arsenic technologies have been developed and used to manufacture ICs and motion microstructures (actuators and sensors). While enabling technologies have been deployed, a spectrum of challenging problems remains. Micro-mechatronic systems have been widely used, and a worldwide market for MMS will be drastically increased in the near future. Analog, discrete, and hybrid MMS have been manufactured using the surface micro-machining technology (process used to fabricate ICs applying CMOS technologies). To deploy and commercialize MMS, a spectrum of problems must be solved, and a portfolio of analytical, numerical, and software design tools needs to be developed using multidisciplinary concepts. Electromagnetics and fluid dynamic, electro–thermo-mechanics and optics, biophysics and biochemistry, mechanical and structural design, analysis and optimization, simulation and virtual prototyping, among other important problems, must be thoroughly researched. There are several key focus areas studied in this paper. In particular, classification, structural synthesis and optimization, modeling and analysis, closed-loop system design and verification, as well as other long-standing problems are addressed and researched.
An Expert System for the Selection of Input Devices

This research effort consisted of the development and implementation of a user interface model in an expert system. The model, User-Input Device Model (UIDM), was composed of three parts: user, device, and task components. The expert system, Input Device Selection Assistant (IDSA), applied primary and secondary measures of ergonomic criteria on combinations of the UIDM components to develop a knowledge base for the selection of an input device. Personal Consultant Plus provided the inference engine to determine the most appropriate device. Results of experimentation and experience taken from human factors literature composed the expertise.
Conditional BMP inhibition in Xenopus reveals stage-specific roles for BMPs in neural and neural crest induction

Bone morphogenetic protein (BMP) inhibition has been proposed as the primary determinant of neural cell fate in the developing Xenopus ectoderm. The evidence supporting this hypothesis comes from experiments in explanted "animal cap" ectoderm and in intact embryos using BMP antagonists that are unregulated and active well before gastrulation. While informative, these experiments cannot answer questions regarding the timing of signals and the behavior of cells in the more complex environment of the embryo. To examine the effects of BMP antagonism at defined times in intact embryos, we have generated a novel, two-component system for conditional BMP inhibition. We find that while blocking BMP signals induces ectopic neural tissue both in animal caps and in vivo, in intact embryos, it can only do so prior to late blastula stage (stage 9), well before the onset of gastrulation. Later inhibition does not induce neural identity, but does induce ectopic neural crest, suggesting that BMP antagonists play temporally distinct roles in establishing neural and neural crest identity. By combining BMP inhibition with fibroblast growth factor (FGF) activation, the neural inductive response in whole embryos is greatly enhanced and is no longer limited to pre-gastrula ectoderm. Thus, BMP inhibition during gastrulation is insufficient for neural induction in intact embryos, arguing against a BMP gradient as the sole determinant of ectodermal cell fate in the frog.
Status of glutathione and glutathione-metabolizing enzymes in menadione-resistant human cancer cells.

Abstract Cloned menadione (MD)-resistant human breast cancer cell lines have been developed and characterized with respect to glutathione (GSH) content and GSH-metabolizing enzymes. Increases in the activities of γ-glutamyltranspeptidase and glutathione-S-transferase were demonstrated in the absence of alterations in the GSH content of two cloned MD-resistant cell lines. The MD-resistant cells also displayed alterations in their growth kinetics, possessing longer doubling times and increased fractions in the G1/O phase of the cell cycle as compared to parental MD-sensitive cells. The possible mechanisms for the resistance to MD, including an increase in repair of MD-induced DNA damage, are discussed.
Design of a high power S-band metamaterial backward-wave oscillator

This paper presents the design of a novel backward-wave oscillator (BWO) that uses a negative index mode in a waveguide filled with a metamaterial (MTM). The MTMBWO is designed to operate at 2.6 GHz with electromagnetic simulations using the HFSS code. CST PIC simulations were performed of the device and predict a saturated output power of 5.75 MW using a 500 keV, 80 A electron beam (14% efficiency). In addition, a brass cold test structure of the proposed MTMBWO was built and tested with a vector network analyzer and showed very good agreement with simulation.
Exceptional total and functional yields of the human adenosine (A2a) receptor expressed in the yeast Saccharomyces cerevisiae.

The yeast Saccharomyces cerevisiae was used to express a medically relevant G-protein coupled receptor (GPCR), the human adenosine (A2a) receptor, with a C-terminal green fluorescent protein (GFP) fusion tag. In prior studies, we established an expression system for A2a-GFP. Here, we quantified the total A2a-GFP expression levels by correlating GFP levels as detected by fluorescence and densitometry to A2a-GFP molecules overexpressed in the system. We also quantified A2a-GFP functional levels by classical radioligand binding assays. Approximately, 120,000 functional A2a-GFP molecules per cell were present on the plasma membrane as determined by radioligand binding. Using whole cell GFP fluorescence, 340,000 A2a-GFP molecules per cell were detected; approximately 70% of those molecules were plasma membrane localized, as determined by using confocal microscopy analysis. These results show that a significant portion of the total expressed protein is functional. In addition, the quick and inexpensive whole cell fluorescence appears to provide a good approximation of functional receptor numbers for this case. Importantly, the amount of functionally expressed A2a-GFP per culture (∼4 mg/L) is among the highest reported for any GPCR in any expression system.
Laminar Flow and Heat Transfer in Spiral Ducts of Rectangular Cross Section

Laminar flow and heat transfer in three-dimensional spiral ducts of rectangular cross section with aspect ratios of 1, 4, and 8 were determined with the aide of the FLUENT computational fluid dynamics program. Peripherally-averaged coefficients of friction and Nusselt numbers are presented as a function of distance from the inlet and of the Dean number. Fully-developed values of friction coefficient and Nusselt number for a constant-radius-of-curvature duct, either toroidal or helical with small pitch, can be used to predict those quantities for the spiral duct in post-entry regions. These results are applicable to spiral-plate heat exchangers.Copyright © 2004 by ASME
Ethical Issues in Dialysis, Series Editor: Aaron Spital,: Profit‐Making in the Treatment of Chronic Kidney Disease: Truth and Consequences

Many have speculated that the quality of dialysis care differs for patients treated in for-profit and not-for-profit facilities. In 1999 we published a study that demonstrated poorer survival and lower rates of listing for renal transplant for patients in for-profit rather than not-for-profit, freestanding centers. While these findings generated substantial discussion, few have commented on their implications. In this article we first discuss potential sources of bias that could impact on the study's results and place the findings in context. We conclude that these disparities are likely to be real, as they are consistent with theorized differences between for-profit and not-for-profit health care organizations and with other evaluations of dialysis facility ownership. We then discuss several policy options for addressing the quality differences we identified. Reducing the outcome discrepancies will not be easy. Upon considering several policy alternatives, we conclude that a widespread effort to link processes of dialysis care to patient outcomes is best suited to reduce the quality differences between for-profit and not-for-profit dialysis units and improve outcomes in both types of facilities.
Using a Galactose Library for Exploration of a Novel Hydrophobic Pocket in the Receptor Binding Site of the Escherichia coliHeat-labile Enterotoxin

The binding of the B subunits ofEscherichia coli heat-labile enterotoxin (LT) to epithelial cells lining the intestines is a critical step for the toxin to invade the host. This mechanism suggests that molecules which possess high affinity to the receptor binding site of the toxin would be good leads for the development of therapeutics against LT. The natural receptor for LT is the complex ganglioside GM1, which has galactose as its terminal sugar. A chemical library targeting a novel hydrophobic pocket in the receptor binding site of LT was constructed based on galactose derivatives and screened for high affinity to the receptor binding site of LT. This screening identified compounds that have 2–3 orders of magnitude higher affinity toward the receptor binding site of LT than the parent compound, galactose. The present findings will pave the way for developing simple and easily synthesizable molecules, instead of complex oligosaccharides, as drugs and/or prophylactics against LT-caused disease.
Rate of delivery of hyperbaric oxygen treatments does not affect response in soft tissue radionecrosis.

Background Soft tissue radiation necrosis (STRN) is effectively treated with hyperbaric oxygen (HBO,), believed to result from stimulation ofangiogenesis in radiation-injured tissue. Thirty to forty HBO2 treatments are usually recommended for STRN. For various reasons, different hyperbaric facilities offer these treatments once or twice daily and from 5-7 days weekly. It is not known whether the clinical response differs as a result of the rate of administration of HBO2 treatments. Methods Details of hyperbaric treatment courses of patients treated for radiation enteritis/proctitis (n = 65) and cystitis (n = 94) at a single institution were reviewed. Outcomes were compared with the total number of HBO2 treatments administered and also rate of treatment administration. Results Responses were similar for both forms of STRN whether the patient averaged fewer or greater than 5 treatments per week, or even or = 7 treatments weekly. Outcome did differ, however, dependant on the total number of treatments administered. Response was better in patients receiving 30 or more total treatments, as compared with fewer. Conclusions Soft tissue radionecrosis of the gastrointestinal tract or bladder is (1) effectively treated with hyperbaric oxygen, (2) has a higher response rate if at least 30 treatments are administered, and (3) is equally responsive to rates of hyperbaric treatment ranging from 3 or fewer to 7 or more treatments per week.
Nonnegativity constrained spectral factorization for image reconstruction from autocorrelation data

The authors consider the factorization of the 1-D and 2-D spectral density functions (z-transforms of real-valued autocorrelation sequences), S(z) and S(z/sub 1/, z/sub 2/) in the forms Sz=F(z)F(z/sup -1/) and S(z/sub 1/, z/sub 2/)=F(z/sub 1/, z/sub 2/) F(z/sub 1//sup -1/, z/sub 2//sup -1/), respectively where the coefficient of polynomials F(z) and F(z/sub 1/, z/sub 2/) are constrained to be nonnegative. The problem is solved only in special cases. In the general situation, the scopes for adapting and generalizing the iterative techniques available for the classical 1-D spectral factorization problem to tackle the nonnegativity constrained spectral factorization problem under study have been analyzed. >
Enhancements of an Adaptive Neighborhood Speckle Filtering Algorithm to Improve Analysis of Polarimetric SAR Imagery

Image noise often hinders the analysis and understanding of most remote sensing imagery. Synthetic aperture radar (SAR) images, in particular, suffer from a phenomenon known as speckle. Speckle is the result of the coherent sum of scattering mechanisms within a resolution cell and is typically modeled as multiplicative noise. Numerous approaches have been taken to reduce speckle, the most promising of which are adaptive and statistically based. These algorithms typically take advantage of the statistics of speckle or the multi-scale image structure to detect regions of similarity. Several of these algorithms also take advantage of the multi-channel nature of polarimetric SAR to improve the region detection. This work presents two enhancements to such an algorithm with an application toward polarimetric parameter estimation and change detection and presents results using the Japanese satellite-based Phased Array L-band Synthetic Aperture Radar (PALSAR) system.
The pH dependence of hydrogen-deuterium exchange in trp repressor: The exchange rate of amide protons in proteins reflects tertiary interactions, not only secondary structure

The pH dependence of amide proton exchange rates have been measured for trp-repressor. One class of protons exchanges too fast to be measured in these experiments. Among the protons that have measurable hydrogen-deuterium exchange rates, two additional classes may be distinguished. The second class of protons are in elements of secondary structure that are mostly on the surface of the protein, and exchange linearly with increasing base concentration (log kex versus pH). The third class of amide protons is characterized by much higher protection against exchange at higher pH. These protons are located in the core of the protein, in helices B and C. The exchange rate in the core region does not increase linearly with pH, but rather goes through a minimum around pH 6. The mechanism of exchange for the slowly exchanging core protons is interpreted in terms of the two-process model of Hilton and Woodward (1979, Biochemistry 18:5834-5841), i.e., exchange through both a local mechanism that does not require unfolding of the protein, and a mechanism involving global unfolding of the protein. The increase in exchange rates at low pH is attributed to a partial unfolding of the repressor. It is concluded that the formation of secondary structure alone is insufficient to account for the high protection factors seen in the core of native proteins at higher pH, and that tertiary interactions are essential to stabilize the structure.
A DSP based real time power quality measurement system

A digital signal processor (DSP) based real-time power supply quality measurement systems is described. The proposed system is centered around a Texas Instruments 32-b floating point TMS320C30 DSP evaluation board. The system is interfaced to an IBM-compatible computer. Voltage and current signals are continuously sampled, and harmonics, power factor, real power, reactive power, distortion factor, etc., are evaluated in real time. The proposed system is flexible and can be altered to perform various other functions. Experimental evaluation of the system shows excellent accuracy in the computed parameters. >
Roundup® and amphibians: The importance of concentration, application time, and stratification

The widespread use of pesticides raises the possibility that non-target organisms might also be affected. To assess this, the traditional approach has been to conduct short-term laboratory experiments spanning a range of lethal concentrations and some longer-duration experiments at sublethal concentrations. While this approach has been very useful, less attention has been paid to the timing of exposure and the impacts of multiple, small exposures versus single, large exposures. We examined the role of application amount, timing, and frequency using outdoor mesocosm communities containing larval amphibians (Rana sylvatica and Bufo americanus) and using a commercial formulation of the herbicide glyphosate (Roundup Original MAX(R)). Consistent with past studies, exposures of up to 3 mg acid equivalent (a.e.)/L caused substantial amphibian death. However, the amount of death was considerably higher when the herbicide was applied earlier in the experiment than later in the experiment. Single, large applications (at different times) had larger effects on tadpole mortality and growth than multiple, small applications (of the same total amount). The results may reflect an acclimation to the herbicide over time. In treatments with high tadpole mortality, there was no resulting increase in periphyton, suggesting that the reduction in tadpole herbivory might have been offset by direct negative impacts of the herbicide. We also discovered that temperature stratification caused herbicide stratification, with higher concentrations near the surface. Such stratification has important implications to the habitat choices of ectotherms that might prefer surface waters for thermoregulation or prefer deeper waters to avoid predators. Collectively, the present study demonstrates the importance of examining multiple applications times and frequencies to understand the impacts of pesticides on organisms.
Going 'on-line' in the environmental scanning process

Online computerized databases (OCDBs) are increasingly being used within organizations for assessing large volumes of information. their use in the environmental scanning process remains relatively limited, however. A test of an OCDBs usefulness in tracking eight issues over a two-and-a-half-year period is reported. The test was part of a trade and economic development project focused on the Caribbean basin. While some methodological and operational questions remain, results suggest that OCDBs can be a powerful addition to the repertoire of information technologies available to researchers and organizations in understanding and managing the impact of issues. >
Do market information processes improve new venture performance

Abstract Does market information improve new venture performance? While some researchers argue that entrepreneurs do not need formal processes to collect and use market information, others suggest that the use of formal market information processes is positively related to firm performance. In this paper, we hypothesize that new venture performance is an increasing function of (1) the firm's level of customer interaction and (2) the use of formal processes for collecting and utilizing market information. We also hypothesize that these linkages will be stronger among new ventures serving emerging markets (i.e., markets in which customer needs and segments are evolving). We test these hypotheses using data collected from 224 new ventures located in the United States. Our findings indicate that, regardless of market condition, formal processes for the collection of market information are positively associated with the use of formal processes for market information utilization and this relationship is stronger among firms serving established markets. In addition, new venture performance is positively associated with the use of formal processes for utilizing market information and this relationship is also stronger in established markets. We also find that, in emerging markets, new venture performance is a positive function of the use of formal processes for collecting market information. Contrary to expectations, we find that, regardless of market condition, the level of customer interaction has a negative relationship with the use of formal processes for market information utilization and no significant relationship with performance.
Endocervical Curettage at Conization to Predict Residual Cervical Adenocarcinoma in Situ

Abstract Objective. To determine if performing an endocervical curettage (ECC) at the time of conization is a useful diagnostic tool for predicting residual cervical adenocarcinoma in situ (AIS) among women who might wish to preserve their fertility. Methods. All patients diagnosed with AIS from 1995 to 2000 at four institutions were identified. Data were retrospectively extracted from clinical records. Women included in the statistical analysis were (1) younger than 40 years, (2) had an ECC performed at the time of the initial cone biopsy, (3) had a clearly demarcated surgical margin pathologically, and (4) underwent a second surgical procedure. Results. Twenty-nine (24%) of 123 AIS patients met criteria for inclusion. The median age was 33 years (range, 17 to 39) and 13 (46%) were nulliparous. Initial surgery was a cold-knife conization ( n = 17) or loop electrosurgical excision procedure ( n = 12). Twelve (41%) ECCs and 15 (52%) cone margins were histologically positive. Sixteen patients underwent a repeat conization; 13 underwent hysterectomy. Thirteen (45%) patients had residual AIS at the time of their second surgical procedure. ECC had a superior positive predictive value (100% vs 47%; P P = 0.01) compared to cone margin in predicting residual AIS. None of the women undergoing fertility-sparing surgery developed recurrent AIS or adenocarcinoma. Conclusion. ECC performed at the time of conization may be a useful tool for predicting residual AIS in women considering fertility preservation.
Feed intake and digestion by Holstein steers fed warm or cool season grass hays with corn, dried molasses, or wheat middlings.

This study determined the effects of adding a small amount of dried molasses to supplemental corn and of supplementing with corn, wheat middlings, or corn-wheat middlings mixture on intake and digestion by Holstein steers fed warn or cool season grass hays. Eight steers (175 kg BW), in two simultaneous Latin squares, were fed, once daily, bermuda-grass (72% NDF) or ryegrass-wheat (58% NDF) hay ad libitum, alone or with approximately .05% BW of dried molasses (with 31% roughage), 5% BW of ground corn, or both. Adding dried molasses to corn decreased feed intake but did not affect digestible OM intake. Total tract digestion of fiber from bermudagrass tended to be enhanced by adding dried molasses to corn. Eight steers (193 kg BW) were used in an experiment with the same design in which similar forages were fed alone or with corn (.5% BW), wheat middlings (.63% BW), or .25% BW of corn plus .31% BW of middlings. Feed intake for both grasses was similar among supplements. Wheat middlings depressed total tract fiber digestion more than corn with both forages. Supplementation with corn depressed fiber digestion slightly more with ryegrass-wheat than with bermudagrass, but wheat middlings had a slightly greater depressing effect on fiber digestion with bermudagrass. Associative effects of mixing corn and wheat middlings in OM digestion and digestible OM intake were negative for bermudagrass and positive for ryegrass-wheat. Interaction among characteristics of basal forage and concentrate modulated feed intake and digestion by ruminants.
Automatic deployment of autonomous cars in a Robotic Urban-Like Environment (RULE)

We present a computational framework and experimental setup for deployment of autonomous cars in a miniature Robotic Urban-Like Environment (RULE). The specifications are given in rich, human-like language as temporal logic statements about roads, intersections, and parking spaces. We use transition systems to model the motion and sensing capabilities of the robots and the topology of the environment and use tools resembling model checking to generate robot control strategies and to verify the correctness of the solution. The experimental setup is based on Khepera III robots, which move autonomously on streets while observing traffic rules.
Influence of “Alternative” C-terminal amino acids on the formation of [b3 + 17 + Cat]+ products from metal cationized synthetic tetrapeptides

The aim of this study was to investigate the dissociation patterns, and in particular the relative abundance of [b(3) + 17 + Cat](+), for peptides with C-termini designed to allow transfer of the -OH required to generate the product ion, but not necessarily as the most favored pathway. Working with the hypothesis that formation of a five-membered ring intermediate, including intramolecular nucleophilic attack by a carbonyl oxygen atom, is an important mechanistic step, several model peptides with general sequence AcFGGX were synthesized, metal cationized by electrospray ionization and subjected to collision-induced dissociation (CID). The amino acid at position X was one that either required a larger ring intermediate (beta-alanine, gamma-aminobutyric acid and epsilon-amino-n-caproic acid to generate six-, seven- or nine- membered rings, respectively) to transfer -OH, lacked a structural element required for nucleophilic attack (aminoethanol) or prohibited cyclization because of the inclusion of a rigid ring (p- and m-aminobenzoic acid). For Ag(+), Li(+) and Na(+) cationized peptides, our results show that amino acids requiring the adoption of larger ring intermediates suppressed the formation of [b(3) + 17 + Cat](+), while amino acids that prohibit cyclization eliminated the reaction pathway completely. Formation of [b(3) - 1 + Cat](+) from the alkali metal cationized versions was not a favorable process upon suppression or elimination of the [b(3) + 17 + Cat](+) pathway: the loss of H(2)O to form [M - H(2)O + Cat](+) was instead the dominant dissociation reaction observed. Multiple-stage dissociation experiments suggest that [M - H(2)O + Cat](+) is not [b(4) - 1 + Cat](+) arising from the loss of H(2)O from the C-terminus, but may instead be a species that forms via a mechanism involving the elimination of an oxygen atom from an amide group.
Ophthalmic fundus imaging: today and beyond.

Abstract Purpose To review and update techniques of posterior segment ophthalmic fundus imaging. Design Literature review and collective experience of the authors. Methods This perspective includes sections on digital imaging, fundus autofluorescence, ultrasonography, angiography, and optical coherence tomography (OCT) -ophthalmoscopy written by leading clinicians and researchers in these areas. Results Digital angiography has become the new standard in the ophthalmic community based upon improved technology which has enhanced resolution, processing time, and ease of image duplication, manipulation, and transmission. A relatively new imaging technique, fundus autofluorescence, highlights lipofuscin deposits and improves our understanding of the metabolic status of the retinal pigment epithelium. Diagnostic ultrasonography continues to be a major adjunct to ocular evaluation where advances now allow for exceptional versatility and portability. High speed angiographic techniques provide detailed visualization of choroidal perfusion which improves our understanding of both normal and pathologic vascular phenomenon. Advances in high-resolution OCT currently under development promise an even more detailed fundus representation. The integration of the scanning laser ophthalmoscope and OCT has produced a dynamic new instrument, the OCT ophthalmoscope, which simultaneously images the fundus in numerous ways with point to point correlation. Conclusions Ophthalmic imaging technology has revolutionized fundus examination. Currently available systems have contributed significantly to our understanding of the pathophysiology and treatment of various retinal diseases. Future advances promise near histologic resolution of retinal structures as well as real-time image manipulation and instantaneous transmission world-wide.