cssi/SciSciGPT-SciSciNet huggingface dataset:
Thalamic activation during an attention-to-prepulse startle modification paradigm: a functional MRI study.

Abstract Background: Prepulse inhibition (PPI) of the startle reflex reflects early stages of information processing and is modulated by selective attention. Animal models indicate medial frontal-thalamic circuitry is important in PPI modulation. We report data from the first functional magnetic resonance imaging (fMRI) study examining whether attending to or ignoring a prepulse differentially activates brain areas within this circuitry. Methods: Ten healthy subjects received structural and functional MRI. During fMRI acquisition, subjects heard intermixed attended and ignored tones serving as prepulses to the startle stimulus. Regions of interest were traced on structural MRI and coregistered to fMRI images. Results: Greater amplitude fMRI blood-oxygen-level-dependent response to attended than ignored PPI conditions occurred in the right thalamus, and bilaterally in the anterior and mediodorsal thalamic nuclei, whereas the startle-alone condition showed deactivation. In transitional medial cortex (Brodmann Area 32), which is involved in affective processing of noxious stimuli, the startle-alone condition elicited the greatest response, the attended-PPI condition showed the smallest response, and the ignored-PPI condition was intermediate. Conclusions: These findings extend animal models to humans by indicating thalamic involvement in the modulation of PPI. Further fMRI investigations may elucidate other key structures in the circuitry underlying normal and disordered modulation of PPI.
Target detection in color imagery: on the path to a color target acquisition model

Existing target acquisition models are effective in the prediction of Target Acquisition (TA) performance for monochrome or single band imagers (visible or infrared). There is currently no performance model for color imagers or fused imagery rendered on color displays. This study is a first step in extending the intensity contrast-based TA models to a three-dimensional color space. The monochrome TA model was developed with a variable, perceived signal to noise ratio threshold (SNRT), in contrast space, to determine target detection probability. In this research, we determined the noise-limited SNRT in the chroma direction for three equally spaced hue angles of CIELAB (Commission Internationale Eclairage L* A* B*) color space. The comparison of the chroma SNRT in these three hues of L*, a*, b* space that may allow an extension of the noise-limited sensor model to this three-dimensional space for color display modeling. Such a model improvement would result in a sensor performance model for both color imagers and for fused imaging color displays. This study investigates the target detection signal to noise threshold of single targets in a noisy color background. Noise is described in terms of signals of both target and noise at three different hues. Target images are presented to observers who are required to locate the target and select it with a mouse. The format of each experiment is that of a "forced choice" human detection perceptual experiment. The images are 64 pixel square with targets of one or four pixels. The results are the signal to noise thresholds in the chroma direction for the three different hues.
A subdomain of MEKK1 that is critical for binding to MKK4.

Abstract Mitogen-activated protein kinase (MAPK) cascades are central components of signal transduction pathways induced by mitogens and stresses. They consist of a three-kinase module in which a mitogen-activated protein kinase kinase kinase (MAP3K) activates a mitogen-activated protein kinase kinase (MAP2K), which in turn activates MAPK. The molecular determinants that underlie specific MAP3K–MAP2K interactions are poorly understood. In this study, we examined the interaction between the MAP3K MEKK1 and MKK4, a MAP2K of the JNK pathway. Select point mutations in subdomain X of the catalytic domain of MEKK1 (MEKK1Δ) were found to impair the ability of MEKK1Δ to bind to and activate MKK4. Such mutations were also found to impair MEKK1Δ-induced activation of an AP1 reporter gene. These studies point to a critical role for subdomain X in the interaction of MEKK1 with MKK4.
Synergistic toxic effects of citrinin, ochratoxin A and penicillic acid in mice

Abstract G. A. Sansing , E. B. Lillehoj , R. W. Detroy and M. A. Miller . Synergistic toxic effects of citrinin, ochratoxin A and penicillic acid in mice. Toxicon14, 213–220, 1976.—The ld 50's in mice of citrinin, ochratoxin A, and penicillic acid injected intraperitoneally were 89, 22, and 100 mg per kg of body weight, respectively. Paired combinations of the mycotoxins, citrinin: ochratoxin A (CI:OA), ochratoxin A:penicillic acid (OA:PA), and penicillic acid:citrinin (PA:CI) elicited synergistic lethal responses. After administration of citrinin, 14C-orotic acid incorporation into both liver and kidney increased significantly by 27 hr with a return to control levels at 51 hr. Treatment with penicillic acid also increased orotic acid incorporation into liver ribonucleic acid (RNA) at 27 hr and at 4 hr in the kidney. Ochratoxin A inhibited orotic acid incorporation into both liver and kidney RNA 6 hr after toxin injection with a subsequent return to control levels at 27 hr. Orotic acid incorporation was inhibited in both kidney and liver 6 hr after treatment with the toxin combination CI:OA, PA:CI stimulated precursor incorporation into kidney RNA at 27 hr and inhibited the function in liver. The OA:PA combination inhibited orotic acid incorporation in both organs 15–27 hr after toxin treatment.
Contribution to the formulation of the theory of groundwater flow through an elastic deformable aquifer

The equation of motion (generalized Darcy's law) of a slightly compressible viscous liquid in an elastic porous medium is derived by means of the theory of interacting continua. The motion is expressed in terms of the macroscopic velocity of the fluid relative to the porous solid. The constitutive equation for the force due to interaction between the solids and the fluid is formulated and discussed. It is suggested that only the tangential (frictional) portion of this force is important in describing the flow of groundwater through a confined aquifer. The tangential part of the interacting force contributes mostly to distortion of the solid whereas the normal portion contributes mostly to the elastic volumetric deformation. In the formulation of the motion of the solid component, it is suggested that only the normal portion of the interacting force is important in defining the storage in an aquifer due to the deformation of the medium. The system of equations, composed of the equation of motion of each component, must be solved simultaneously because fluid pressure and aquifer dilatation are coupled. Uncoupling may be accomplished in several simplified cases: deformation of a porous medium in the vertical direction only; deformation in the radial (or horizontal) direction only, uniform over the thickness of the aquifer; leaky aquifer with bB < 0.3 (b, the thickness of the aquifer; B, the leakage factor). The specific storage may be defined only in the cases where a simple relationship between fluid pressure and dilatation exists. Since this relationship is not unique, there is no unique definition of the specific storage. If the local fluid inertia is not negligible, the governing differential equation is the telegrapher's equation. The solution to a typical boundary-value problem yielded the following conclusion. The pressure disturbance travels through an elastic porous medium with a finite velocity. The more compressible the aquifer the slower the change in pressure that travels through the porous medium and the higher time lag that appears.
1998 Warkany lecture: signaling pathways in development.

Cell-cell signaling pervades all aspects of development, not just in vertebrates, but in all animals (metazoa). It is a typifying characteristic of the major multicellular life forms, animals, plants, and fungi, which diverged about 1.2 billion years ago from a common ancestor descended from a lineage of unicellular life forms. In metazoa, at least 17 kinds of signal transduction pathways operate, each distinguished by its transduction intermediates. Five kinds predominate in early embryonic development, namely, the Wnt, TGF-β, Hedgehog, RTK, and Notch pathways. Five more are used in late development, and seven more in the functions of differentiated cells. The pathways must have evolved and become conserved in pre-Cambrian times before the divergence of basal members of most of the modern phyla. In metazoan development and physiology, the responses of cells to intercellular signals include cell proliferation, secretion, motility, and transcription. These responses tend to be conserved among metazoa and shared with unicellular eukaryotes and in some cases even with unicellular prokaryotes. Protein components of the responses date back 2 billion years to ancestral eukaryotes or 3 billion to ancestral prokaryotes. Each metazoan developmental process consists of a network of signals and responses, and many of these networks are conserved among metazoa, for example, by insects and mammals. The study of model organisms, even of nonvertebrate groups, is expected to continue to contribute greatly to the understanding of mammalian development and to offer opportunities to analyze the effects of toxicants on development, as well as opportunities to devise incisive assays for toxicants. Teratology 60:226–239, 1999. © 1999 Wiley-Liss, Inc.
A note on stable flow-equivalent aggregation in closed networks

We introduce the Conditional Mean Value Analysis (CMVA) algorithm, an exact solution method for product-form load-dependent closed queueing networks that provides a numerically stable solution of models where the load-dependent Mean Value Analysis (MVA) is numerically unstable. Similarly to the MVA algorithm for constant-rate queues, CMVA performs operations in terms of mean quantities only, i.e., queue-lengths, throughput, response times. Numerical stability derives from a new version of the MVA arrival theorem for load-dependent models which is expressed in terms of mean queue-lengths instead of marginal probabilities. The formula is obtained by the analysis of the conditional state spaces which describe network equilibrium as seen by jobs during their residence times at queues. We also provide a generalization of CMVA to multiclass models that preserves the numerical stability property.
Increased Stiffness of Bioresorbable Plates Following Heating and Three-Dimensional Contouring

A wide copolymer bioresorable plate offers increased structural stiffness following heated contouring of the plate to various diameters which increases its resisting moment of inertia. The increase in bending and torsional stiffness of this design is measured as a function of cross-sectional radius of curvature achieved. Its structural stiffness is compared to three other standard fixation methods used for metacarpal fracture. Substantial increases in stiffness are found after contouring of the wide bioresorbable plate to fit diameters similar to those found in metacarpal bones.Copyright © 2004 by ASME
A one-megapixel reflective spatial light modulator system for holographic storage

A prototype reflective spatial light modulator (SLM) system has been developed for writing megabit pages of data into a holographic medium at a rate of 12 pages per minute. The SLM is based upon a crystalline-silicon reflective active-matrix array with integrated data drivers, using liquid crystal (LC) electrooptics and a personal computer system with an interface to provide data. The LC has been optimized for high contrast and efficiency with coherent illumination. The resolution-limited contrast was measured at 4:1, which was high enough to provide bit-error-free charge-coupled-device images using modulation and error-correction codes.
Soybean Yield as Affected by Biomass and Nitrogen Uptake of Cereal Rye in Winter Cover Crop Rotations

The inclusion of cereal rye (Secale cereale L.) as winter cover crop (WCC) following corn (Zea mays L.) has been suggested as a valuable nutrient management tool in the typical corn-soybean [Glycine max (L.) Merr.] rotation of the U.S. Midwest. However, little information is available on the effects of rye WCC on the soybean crop. The objectives of this study were to quantify biomass and nitrogen (N) uptake of rye WCC and to evaluate the effect of rye WCC on soybean yield. The effects of four rotations (corn/soybean, hairy vetch-corn/ryesoybean, rye-corn/rye-soybean, and hairy vetch + rye biculture-oral rye-soybean) on soil residual NO 3 -N content, rye biomass, N content, and C/N ratio, soil residue cover, soybean light interception, and grain yield were investigated at Urbana and Brownstown, IL. Rye N content was highly correlated with soil residual NO 3 -N content (r = 0.64, p < 0.0001). Rotations that only included hairy vetch (Vicia villosa L.) reached maximum N content at lower corn N rates compared with rotations with rye. Soybean light interception at R1, R4, and R6 growth stages and grain yield were not affected by the treatments. Rye WCC planted after corn appears to take up a significant proportion of residual NO 3 -N without affecting soybean grain yield, providing an environmental service to the agroecosystem.
Interaction of amphotericin B with membrane lipids as viewed by 2H-NMR

The effects of amphotericin B upon the organization and dynamics of multibilayer membranes of dimyristoylphosphatidylcholine (DMPC) were investigated by means of 2H-NMR. At high amphotericin B concentrations (30 mol% with respect to the lipid) and at temperatures above 25 degrees C, DMPC experiences two different environments which are in slow exchange on the 2H-NMR time scale. In one of these, the lipid is immobilized by the antibiotic, in a molar ratio of approximately 1:1, whereas the lipid unsequestered by amphotericin B is more ordered than in its pure state. This ordering effect is perceived at relatively low antibiotic doses (4%). The local lipid order, and the relative percentage, of sequestered DMPC, are temperature-independent (up to 65 degrees C), whereas the ordering of the unsequestered lipid domain is not. The perturbation induced by amphotericin B is manifest similarly at the edges as well as in the center of the bilayer. Antibiotic addition leads to large decreases in the transverse relaxation time, T2, of the labelled lipid, but not in the spin-lattice relaxation time, T1. This indicates an increased density of slow motional modes and little change in rapid motions.
Fatal spontaneous left main coronary artery thrombosis as a rare complication of noncardiac surgery.

A 72-year-old man with a history of anterior wall myocardial infarction, who had stenting to his left anterior descending artery, developed an acute episode of dyspnea, hypoxemia and anginal chest pain three days after above-the-knee amputation for dry gangrene of the left leg. A physical examination revealed bilateral lung rales and a soft ejection systolic murmur at the left sternal border. Transient new lateral ST segment elevation associated with reciprocal inferior ST segment depression and prior anterior-septal infarct were evident on his electrocardiogram. Cardiac catheterization showed a filling defect in the middle segment of the left main coronary artery (Figure 1). During the procedure, the patient became more dyspneic and developed fatal cardiopulmonary arrest; he did not respond to resuscitative measures (1). Figure 1) Coronary angiogram showing a filling defect (arrow) in the middle segment of the left main coronary artery, representing a thrombus. Also noted was severe in-stent stenosis of the proximal left anterior descending artery
Current and future trends in demographics of veterinary medicine in California.

Objective To evaluate the present and future supply of veterinarians in California, in light of changing trends in animal ownership. Design Database analysis. Sample population Human and animal populations, including populations of veterinarians, throughout the United States. Procedures Data on animal and human populations were compiled from a number of sources, including the US Census Bureau, American Veterinary Medical Association, State of California Department of Finance, and State of California Veterinary Medical Board. The distribution of veterinarians in California was contrasted with other health professionals in California and with that of veterinarians in other states. Recent changes in veterinary medical demographics in California were quantified and used to develop in-state projections about the supply of veterinarians for the next 20 years. Results Although California is the most populous of the 50 states, only 7 states had fewer veterinarians per capita. Furthermore, California ranked next to last among states in increase of number of veterinarians between 1990 and 1995. Los Angeles County had the smallest per-capita number of veterinarians among 9 populous California counties. During that period, California had a net gain of only 6 veterinarians who were exclusively or predominantly large-animal or mixed-animal practitioners. Conclusions and clinical relevance If current trends continue, the per-capita number of veterinarians will continue to decrease in California. To maintain the current ratio of 17.8 veterinarians/100,000 people in California in the future, we estimate that an additional 50 veterinarians above the currently predicted increase will be required annually.
Nosocomial transmission of disease caused by nontypeable strains of Haemophilus influenzae

Abstract purpose: The authors evaluated a geographic and temporal cluster of lower respiratory tract infections due to unencapsulated (serologically nontypeable) Haemophilus influenzae to determine whether this event represented the transmission of a single clone. methods and materials: H influenzae was recovered from eight patients at a nursing home and from three patients in an adjacent acute care hospital. Serotypes, biotypes, outer membrane protein profiles, and multilocus enzyme genotypes were determined to characterize bacterial isolates. Patient records were retrospectively examined to determine clinical and epidemiologic characteristics. results: During a 10-day period in September 1991, lower respiratory tract infections caused by H influenzae were diagnosed in four patients residing in a single nursing home unit. Oropharyngeal cultures from four of seven asymptomatic roommates of these patients also grew H influenzae . During the month before and after the nursing home cluster of cases, four other individuals in acute care areas of the hospital had positive sputum cultures for H influenzae . Three of these latter specimens were also available for analysis. All H influenzae isolates were unencapsulated and β-lactamase-negative. Eight of the nine isolates from the nursing home patients (two morphologically distinct colony types of H influenzae were isolated from one case) had a single outer membrane protein profile arbitrarily designated as X and a single multilocus enzyme genotype arbitrarily designated as A. In contrast, none of the isolates from the acute care cases had this profile ( P H influenzae was not recovered from follow-up oropharyngeal cultures obtained 1 week after the completion of therapy. No β -lactamase-negative H influenzae were identified in this unit during the subsequent 9 months. conclusion: This study furnishes strong evidence for the nosocomial transmission of a clone of unencapsulated H influenzae in a nursing home unit. Epidemiologic data showed temporal and geographic clustering of respiratory tract infections and colonization by H influenzae . Outer membrane protein profiles and multilocus enzyme genotype analysis indicated that seven of eight patients at the nursing home carried a single clone of unencapsulated H influenzae . Laboratory and epidemiologic data also demonstrated the presence, and possible nosocomial transmission, of a second clone of unencapsulated H influenzae in a physically separate area of the hospital. Finally, although a causal relationship is not proven, the outbreak ended following the administration of rifampin prophylaxis of asymptomatic carriers.
Relation of birth weight to lean and fat thigh tissue in young men.

BACKGROUND: Birth weight is positively associated with body mass index (BMI, kg/m2) in later life, but is inversely associated with cardiovascular risk. To understand this paradox, we examined the relationships between birth weight, adult BMI, and estimations of lean and fat tissue in young men. METHODS: From 192 applicants for military service (ages 17–22 y, mean BMI 23.2 kg/m2) with known birth weights we measured the circumference and anterior skinfold thickness at midthigh to estimate thigh muscle+bone area and subcutaneous fat area. Linear regression models including birth weight as the independent variable were adjusted for race and adult height. RESULTS: BMI was linearly associated with birth weight (standardized regression coefficient, [SRC]=+0.27; P=0.0004), as was the thigh muscle+bone area (SRC=+0.22; P=0.0029), but not the thigh subcutaneous fat area (SRC=+0.13; P=0.086). The BMI–birth weight association was reduced by 68% when the regression model was further adjusted for thigh muscle+bone area. Separate adjustment for thigh subcutaneous fat, however, reduced the BMI–birth weight association by only 30%. Waist circumference was also associated with birth weight (SRC=+0.24; P=0.0014), sagittal abdominal diameter was weakly associated (SRC=+0.17; P=0.028), but waist/thigh ratio and abdominal diameter index were not associated with birth weight. INTERPRETATION: The larger BMI associated with higher birth weight may reflect increments in lean tissue more than increments in fat. Birth weight's influence on lean tissue is observed in the thigh and, among fit young men, perhaps at the waist. Increased muscularity in young men may partly explain the cardiovascular benefit in middle age ascribed to higher birth weight.
Weight suppression as a predictor variable in treatment trials of bulimia nervosa and binge eating disorder.

Objective: The purpose of this study was to examine weight suppression (WS) as a predictor of treatment outcome among individuals with binge eating disorder (BED) and bulimia nervosa (BN). Method: Participants were diagnosed with BED or BN and took part in separate treatment studies. The current study examined WS as a predictor of treatment completion, weight change during treatment, and symptomatic abstinence, as well as percent reduction in binge eating and purging frequency. Results: WS did not significantly predict treatment completion or treatment outcome in either group. Discussion: Contrary to some previous findings, these results failed to demonstrate that WS was predictive of outcome at the end of treatment in BN. In addition, WS was not predictive of treatment outcome or dropout status in BED.
A distributed control model for the air-righting reflex of a cat

A multisegment, multijoint model of a falling animal is presented to examine the effectiveness of a two-stage control scheme in a zero-momentum self-righting maneuver. The model contains a much larger number of degrees of freedom than is required to execute a self-righting maneuver and is thus capable of providing multiple solutions for the same task. The decentralized control scheme is designed to achieve gross turning in minimum time and to maintain a steady orientation relative to gravity after the turn has been achieved. The scheme is able to determine the sequence of steps necessary to execute the motor task and also incorporates learning features. Results from various simulations are presented and their implications discussed.
An assessment of costa Rica's coastal management program

Abstract Costa Rica has a long customary and legal history of reserving its Pacific Coast and Caribbean Sea for public benefit. The most important law for the management of the coast, enacted in 1977, focuses on the zona maritimo‐terrestre (the marine and terrestrial zone). It has been actively implemented by national and local government. Costa Rica thus has the distinction of possessing the longest history (now 12 years) of coastal program implementation among developing nations. A review of the literature on environmental management in developing countries indicates that there are few other success stories. The analysis of Costa Rica's program demonstrates that it has achieved many of its objectives. The public has more access to the beaches, the aesthetic quality of coastal development has improved, and important coastal habitats have more protection. Seven factors are selected to explain why the program is succeeding. Although the program is 12 years old, there is still much work to be done. The inst...
Ultralow Detection Limit of a Near-Infrared Dye by Diode-Laser-Induced Fluorescence in a Flowing Stream

Diode lasers are compact, highly efficient, temperature-tunable, long-lived, low-noise, simple-to-operate, and relatively inexpensive solid-state lasers that are rapidly becoming more useful in spectrochemical studies. Recently, Imasaka and Ishibashi reviewed the uses of diode lasers in trace chemical analyses. Due to the virtual elimination of background fluorescence from sample impurities, and the large wavelength shift of the Raman scatter from the solvent at red and near-infrared excitation wavelengths, the rather powerful diode lasers are very useful in laser-induced fluorescence (LIF) detection of very small amounts of red and near-infrared fluorophors. To our knowledge, the lowest detection limit obtained of a fluorescent species with the use of diode laser excitation is 46,000 molecules in a 56-nL volume of the laser dye IR-140 flowing in a liquid jet emanating from a capillary. With some simple improvements upon that system, the detection limit has been lowered to 3000 molecules of IR-140 in a 250-pL volume.
The gecko visual pigment: its photosensitivity and the effects of chloride and nitrate ions

By use of the method of photometric curves, the photosensitivity of the major and ion-sensitive pigment of Gekko gekko has been determined and compared with that of rhodopsins of the frog (Rana pipiens) and of the fish (Porichthys notatus). In the presence of Cl$^{-}$ (or Br$^{-}$) the gecko pigment has the same photosensitivity as the other A$_{1}$ rod pigments, but unlike these, the addition of NH$_{2}$OH does not lead to a Dartnall effect, i.e. an enhancement in the measured rate of photic bleaching. This is because the gecko pigment has no meta-III intermediate. In the Cl$^{-}$-deficient state the gecko pigment has a photosensitivity 0.8 times that of the Cl$^{-}$-provided system. The increase in photosensitivity brought on by Cl$^{-}$ is quantitatively accounted for by the Cl$^{-}$-induced hyperchromic effect. The addition of NH$_{2}$OH to the system without added Cl$^{-}$ leads to a small increase in measured rate of photic bleaching with an apparent 13% increment in photosensitivity. This is not a classical Dartnall effect for here again no meta-III is involved. The possibility is raised of an additional, yet undiscovered, action of NH$_{2}$OH on the opsin moiety. Nitrate ions (NO$_{3}^{-}$) are known to produce an increase in extinction coefficient similar to that of Cl$^{-}$ and a hypsochromic shift in the spectral absorbance. Despite the hyperchromic action, NO$_{3}^{-}$ produces a reduction in the measured rate of photic bleaching, an effect explained by the appearance of a meta-III type intermediate absorbing at about 470 nm. While Cl$^{-}$ is able to antagonize the NO$_{3}^{-}$-induced hypsochromic shift, it is unable to reverse the NO$_{3}^{-}$-induction of meta-III. This, along with other differences in responses of the gecko pigment to these two ions, suggests that Cl$^{-}$ and NO$_{3}^{-}$ act at two different sites and produce unique conformational changes in the protein molecule.
Histone acetyltransferase (HAT) activity of p300 modulates human T lymphotropic virus type 1 p30II-mediated repression of LTR transcriptional activity.

Human T-lymphotropic virus type-1 (HTLV-1) is a deltaretrovirus that causes adult T cell leukemia/lymphoma, and is implicated in a variety of lymphocyte-mediated inflammatory disorders. HTLV-1 provirus has regulatory and accessory genes in four pX open reading frames. HTLV-1 pX ORF-II encodes two proteins, p13II and p30II, which are incompletely defined in virus replication or pathogenesis. We have demonstrated that pX ORF-II mutations block virus replication in vivo and that ORF-II encoded p30II, a nuclear-localizing protein that binds with CREB-binding protein (CBP)/p300, represses CREB and Tax responsive element (TRE)-mediated transcription. Herein, we have identified p30II motifs important for p300 binding and in regulating TRE-mediated transcription in the absence and presence of HTLV-1 provirus. Within amino acids 100–179 of p30II, a region important for repression of LTR-mediated transcription, we identified a single lysine residue at amino acid 106 (K3) that significantly modulates the ability of p30II to repress TRE-mediated transcription. Exogenous p300, in a dose-responsive manner, reverses p30II-dependent repression of TRE-mediated transcription, in the absence or presence of the provirus, In contrast to wild type p300, p300 HAT mutants (defective in histone acetyltransferase activity) only partially rescued p30II-mediated LTR repression. Deacetylation by histone deacetylase-1 (HDAC-1) enhanced p30II-mediated LTR repression, while inhibition of deacetylation by trichostatin A decreases p30II-mediated LTR repression. Collectively, our data indicate that HTLV-1 p30II modulates viral gene expression in a cooperative manner with p300-mediated acetylation.
Effects of thermal exposure on the properties of two γ alloys

Abstract TiAl alloys with various alloying additions show promise as high temperature materials because of their high temperature strength and modulus. Recent strides in processing and microstructural control produced alloys which exhibit an acceptable balance of properties for aerospace applications. However, little is known about the influence of the high temperature exposures, which these materials will experience in service, on the mechanical properties. Therefore, a study was undertaken to examine the effects of thermal exposure on the tensile properties of two wrought alloys: Ti-47Al-2Mn-2Nb and Ti-47Al-1.6Cr-0.9V-2.4Nb. The effects of microstructure and exposure at temperatures spanning the anticipated use range were investigated.
Elementary discontinuity formulas and mueller's regge hypothesis

We propose to interpret Mueller's recent work on inclusive cross sections in terms of the elementary discontinuity equations for multiparticle scattering amplitudes. The paths of continuations for obtaining these discontinuities are given. We find that, in order to make our identification meaningful, the emergence of anomalous thresholds is necessary to "shield" the effects of box-diagram Landau singularities. We also discuss how Mueller's Regge hypothesis can be derived from the multi-Regge model, provided singularities other than normal thresholds are absent in the asymptotic expansion.
Preemptive Distal Revascularization—Interval Ligation to Prevent Ischemic Steal After Hemodialysis Access Surgery

ialysis access steal syndrome (DASS) occurs in 2% to 8% of atients after hemodialysis access surgery and affects thouands of people in the United States each year. Dialysis ccess steal syndrome occurs when blood that normally suplies a distal arterial bed reverses flow and is redirected hrough the AV fistula. Factors such as high fistula flow rates, ative vessel stenosis or occlusions, and poor collateral flow ct synergistically to cause DASS. Diabetics are particularly rone to developing a steal because of their diffuse calcific icrovascular disease. Fistulas that originate from the brachial rtery are the most at risk for DASS because they lack the ollateral flow found in radial-based fistulas. Autogenous vein rafts dilate slowly and typically result in DASS symptoms that evelop gradually over time while exogenous (PTFE) grafts evelop early ( 24 h) symptoms because of their immediate igh flow rate. Studies of tapered PTFE grafts designed to ncrease resistance, and hypothetically to reduce DASS, have hown little benefit. The symptoms of DASS range from mild, intermittent ain or numbness to tissue loss, motor dysfunction, and ontracture. Frequently, a patient’s symptoms are worse on emodialysis because dialysis lowers the mean arterial presure exacerbating the steal. It is difficult to determine which atients will benefit from early revascularization because ild symptoms often resolve over time and there are no eliable predictors of progression. Valintine et al prospecively performed preoperative finger pressures on 72 patients n an effort to classify patients at risk for DASS. They found n increased incidence of DASS in patients with lower preperative finger pressures but no absolute pressure below hich a steal was inevitable. Digital photoplethysmography, ressure indices, and nerve conduction studies are good ethods to quantitatively follow patients with DASS in the
The interleukin-3 receptor alpha chain is a unique marker for human acute myelogenous leukemia stem cells

Recent studies suggest that the population of malignant cells found in human acute myelogenous leukemia (AML) arises from a rare population of leukemic stem cells (LSCs). LSCs have been documented for nearly all AML subtypes and have been phenotypically described as CD34+/CD38- or CD34+/HLA-DR-. Given the potentially critical role of these primitive cells in perpetuating leukemic disease, we sought to further investigate their molecular and cellular characteristics. Flow cytometric studies using primary AML tissue showed that the interleukin-3 receptor alpha chain (IL-3Ralpha or CD123) was strongly expressed in CD34+/CD38- cells (98 +/- 2% positive) from 16 of 18 primary specimens. Conversely, normal bone marrow derived CD34+/CD38- cells showed virtually no detectable expression of the CD123 antigen. To assess the functional role of IL-3Ralpha positive cells, purified CD34+/CD123+ leukemia cells were transplanted into immune deficient NOD/SCID mice. These experiments showed that CD123+ cells were competent to establish and maintain leukemic populations in vivo. To begin to elucidate a biological role for CD123 in leukemia, primary AML samples were analyzed with respect to signal transduction activity in the MAPK, Akt, and Stat5 pathways. Phosphorylation was not detected in response to IL-3 stimulation, thereby suggesting CD123 is not active in conventional IL-3-mediated signaling. Collectively, these data indicate that CD123 represents a unique marker for primitive leukemic stem cells. Given the strong expression of this receptor on LSCs, we propose that targeting of CD123 may be a promising strategy for the preferential ablation of AML cells.
Cypha™ [Propionic acid, 2-(4-methoxyphenol) salt] inhibits sweet taste in humans, but not in rats

Cypha, propionic acid, 2-(4-methoxyphenol) salt, is a commercially available sweet taste inhibitor used in food products. The present study examined whether or not Cypha blocked the sweet taste response of rats. This was accomplished by measuring the consummatory response of rats to sucrose solutions during short-term taste tests. Nondeprived female rats were given 2-bottle choice tests (10 min) with different sucrose solutions. When given the choice between 10% sucrose and 10% sucrose containing Cypha at concentrations of 0.0125% to 0.10%, the rats showed no reliable preference for one or the other solution. In other tests, they reliably preferred 10% sucrose to 8%, 6%, and 4% sucrose, demonstrating the sensitivity of the behavioral test. To confirm the activity of the Cypha sample, a second experiment was conducted with human subjects. Using a visual analogue scale, the subjects rated the sweetness of various sucrose solutions (0% to 10%) and 10% sucrose solutions containing Cypha at concentrations of 0.0125% or 0.025%. Cypha reliably reduced the sweetness ratings of the sucrose solution. The 10% sucrose + 0.0125% Cypha solution was judged isosweet to 2.3-2.9% sucrose, and the 10% sucrose + 0.025% Cypha solution was rated as isosweet to a 1.2% sucrose solution. Taken together, these data confirm prior reports on the sweetness-inhibitory effect of Cypha in humans and demonstrate its ineffectiveness in rats. These findings are consistent with other reported differences between rats and humans in their response to other sweetness inhibitors, as well as to artificial sweeteners.
Stiffness and heterogeneity of the pulmonary endothelial glycocalyx measured by atomic force microscopy

The mechanical properties of endothelial glycocalyx were studied using atomic force microscopy with a silica bead (diameter ∼18 μm) serving as an indenter. Even at indentations of several hundred nanometers, the bead exerted very low compressive pressures on the bovine lung microvascular endothelial cell (BLMVEC) glycocalyx and allowed for an averaging of stiffness in the bead-cell contact area. The elastic modulus of BLMVEC glycocalyx was determined as a pointwise function of the indentation depth before and after enzymatic degradation of specific glycocalyx components. The modulus-indentation depth profiles showed the cells becoming progressively stiffer with increased indentation. Three different enzymes were used: heparinases III and I and hyaluronidase. The main effects of heparinase III and hyaluronidase enzymes were that the elastic modulus in the cell junction regions increased more rapidly with the indentation than in BLMVEC controls, and that the effective thickness of glycocalyx was reduced. Cytochalasin D abolished the modulus increase with the indentation. The confocal profiling of heparan sulfate and hyaluronan with atomic force microscopy indentation data demonstrated marked heterogeneity of the glycocalyx composition between cell junctions and nuclear regions.
Boston Bowel Preparation Scale scores provide a standardized definition of “adequate” for describing bowel cleanliness

Background Establishing a threshold of bowel cleanliness below which colonoscopies should be repeated at accelerated intervals is important, yet there are no standardized definitions for an adequate preparation. Objective To determine whether Boston Bowel Preparation Scale (BBPS) scores could serve as a standard definition of adequacy. Design Cross-sectional observational analysis of colonoscopy data from 36 adult GI endoscopy practices and prospective survey showing 4 standardized colonoscopy videos with varying degrees of bowel cleanliness. Setting The Clinical Outcomes Research Initiative. Patients Average-risk patients attending screening colonoscopy. Interventions Colonoscopy. Main Outcome Measurements Recommended follow-up intervals among average-risk, screening colonoscopies without polyps stratified by BBPS scores. Results We evaluated 2516 negative screening colonoscopies performed by 74 endoscopists. If the BBPS score was ≥2 in all 3 segments (N = 2295), follow-up was recommended in 10 years in 90% of cases. Examinations with total BBPS scores of 3 to 5 (N = 167) had variable recommendations. Follow-up within 1 year was recommended for 96% of examinations with total BBPS scores of 0 to 2 (N = 26). Similar results were noted among 167 participants in a video survey with pre-established BBPS scores. Limitations Retrospective study. Conclusion BBPS scores correlate with endoscopist behavior regarding follow-up intervals for colonoscopy. A total BBPS score ≥6 and/or all segment scores ≥2 provides a standardized definition of adequate for 10-year follow-up, whereas total scores ≤2 indicate that a procedure should be repeated within 1 year. Future work should focus on finding consensus for management of examinations with total scores of 3 to 5.
Information ethics in a responsibility vacuum

The authors start with the premise that the field of information technology is not a "profession," because it is missing some of the defining characteristics of a profession. In particular, the authors claim the field is impotent in terms of certification and meaningful sanctions for unprofessional behavior. Furthermore, unlike "true" professions, leadership (with the frequent exception of IT in academia) is more often than not in hands of someone who has not come "up through the ranks" and therefore does not enjoy peer status.Handicapped by lack of credentialing, the inability to deal effectively with unprofessional behavior, and non-peer leadership, the resulting power vacuum has led to a responsibility vacuum, which in turn complicates issues of information ethics.The authors then argue that the IT field, whatever it considers itself to be, or is perceived by society to be, has a responsibility to society to disclose its position on ethical issues: to proclaim or disclaim such positions if there is consensus or acknowledge disagreement within the field in the absence of consensus. Specifically, there arises as societal obligation to "own up" to the realities of our not being a profession and such implications as our inability to deal with unprofessional behavior.The authors conclude that information ethicists must not only assist the field in identifying ethical issues and formulating appropriate positions, but they must also lobby the field regarding the importance of keeping society informed on the existence, non-existence, or evolution of such positions; and directly alert society, on behalf of the field, to the existence, non-existence, or evolution of such positions. In particular, the authors assert that any progress the field can make in resolving ethical jurisdiction---who gets to have say in matters of information ethics---will have an immense positive impact on the future of information ethics, contribute significantly to progress in matters of legal jurisdiction, and may even assist the field in resolving its identity.
Concerning the chemical synthesis of 3β-hydroxy-5α-cholest-8(14)-en-15-one, a novel regulator of cholesterol metabolism

A four-step synthesis of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (I) from 7-dehydrocholesterol is described. This synthesis, which is efficient and suitable for kilogram scale work, was carried out in a 33% overall average yield (39% overall best yield). A major byproduct of the hydrolysis of 3 beta-benzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene to I was found to be the ring C aromatic sterol 12-methyl-18-nor-5 alpha-cholesta-8,11,13-trien-3 beta-ol. Several other intermediates and byproducts of these reactions were also identified. All new sterols were characterized by 1H- and 13C-NMR.
Optimal binary prefix-condition codes with ordinal probabilities

Probability estimates for letters in a finite alphabet are derived in order to apply the Huffman algorithm to determine an optimal binary prefix-condition code. The estimates maximize the entropy subject to constraints specifying second-level orderings of the letters' likelihoods. These are compared to estimates obtained from another probability estimation technique described in the decision theory literature using the English alphabet as an example. © 1990 John Wiley & Sons, Inc.
Another path to ERK activation.

In this issue of Blood , Kumkhaek et al demonstrate a role for the Ras-like protein MASL1 in erythroid development. MASL1 acts at least in part by stimulating the Raf mitogen-activated protein kinase kinase (MEK) extracellular signal-regulated kinase (ERK) pathway.[1][1] Ras proteins are molecular
Direct two-dimensional electrostatic potential cross-sectional mapping of sub-30-nm MOSFET under operation mode using electron holography

Electron holography (EH) cross-sectional observations were used to delineate terminal-voltage induced changes in an electrostatic potential distribution in a MOSFET under operating conditions. Gate and drain voltages were applied to a 25-nm-gate-length MOSFET during EH observations to investigate how the terminal-voltage application changed the potential. Combined with a precise device simulation, this EH observation enables us to understand short-channel device behavior, such as drain-induced barrier-height lowering, under actual operation conditions that lead to more comprehensive and reliable device design.
Bauschinger effect during cyclic straining of two ductile phase alloys

Abstract The Bauschinger effect has been examined for monotonie and cyclic straining conditions in a series of binary α, α + β and β Ti-Mn alloys, heat treated to produce constant composition of phases with different morphologies and sizes. For monotonic straining the average Bauschinger strain (ABS) was found to increase with strain over the range of plastic strains used, up to 2%, to be maximum at about 26 vol.% β and to be higher for equiaxed E(α) than for Widmanstatten plus grain boundary (W + GB)α structures. Over the range of particle sizes (either α or β) studied (1–12 μm), the ABS decreased with increasing particle size. After a number of constant strain cycles, the ABS increased and the reverse stress, at which flow began, decreased in the β alloy, when the cyclic flow stress was the same as the monotonic flow stress. In a number of instances permanent softening, as illustrated by parallelism of forward and reverse curves, was not observed. Plastic flow commences in the softer phase, α. The maximum ABS in 26 vol.% β was attributed to interface effects, which restrict flow in α, and to strain concentration in α, which occurs because the β generally begins to deform plastically at much higher stresses. The lower ABS in W + GBα structure was attributed to the greater ease of slip transfer from α to β because of the Burgers orientation relationship between the two phases [29]. The greater ABS in β and the decreased reverse flow stress under cyclic straining conditions is ascribed to an increase in mobile dislocation density or to decreased flow resistance because of possible metallurgical changes and to an increased back stress. The form of the reverse stress-strain curve and conditions for the absence of permanent softening are considered.
Treating cutaneous T-cell lymphoma with highly irregular surfaces with photon irradiation using rice as tissue compensator.

Purpose: Cutaneous T-cell lymphoma (CTCL) is known to have an excellent response to radiotherapy, an important treatment modality for this disease. In patients with extremity and digit involvement, the irregular surface and depth variations create difficulty in delivering a homogenous dose using electrons. We sought to evaluate photon irradiation with rice packing as tissue equivalence and determine clinical tolerance and response. Materials and Methods: Three consecutive CTCL patients with extensive lower extremity involvement including the digits were treated using external beam photon therapy with rice packing for tissue compensation. The entire foot was treated to 30-40 Gy in 2-3 Gy per fraction using 6 MV photons prescribed to the mid-plane of an indexed box filled with rice in which the foot was placed. Optically stimulated luminescence dosimeter (OSLD) was used for dose measurement to determine the dose deposition to the skin surface. Treatment tolerance and response were monitored with clinical evaluation. Results: All patients tolerated the treatment without treatment breaks. Toxicities included grade 3 erythema and desquamation with resolution within 4 weeks. No late toxicities were observed. All four treated sites had partial response (PR) by the end of the treatment course. All patients reported improved functionality after treatment, with less pain, drainage, or swelling. No local recurrence has been observed in these patients with a median follow-up time of 14 months. Conclusion: Tissue compensation with rice packing offers a convenient, inexpensive and reproducible method for the treatment of CTCL with highly irregular surfaces.