cssi/SciSciGPT-SciSciNet huggingface dataset:
Vasoconstrictor-induced endocytic recycling regulates focal adhesion protein localization and function in vascular smooth muscle

Turnover of focal adhesions (FAs) is known to be critical for cell migration and adhesion of proliferative vascular smooth muscle (VSM) cells. However, it is often assumed that FAs in nonmigratory, differentiated VSM (dVSM) cells embedded in the wall of healthy blood vessels are stable structures. Recent work has demonstrated agonist-induced actin polymerization and Src-dependent FA phosphorylation in dVSM cells, suggesting that agonist-induced FA remodeling occurs. However, the mechanisms and extent of FA remodeling are largely unknown in dVSM. Here we show, for the first time, that a distinct subpopulation of dVSM FA proteins, but not the entire FA, remodels in response to the α-agonist phenylephrine. Vasodilator-stimulated phosphoprotein and zyxin displayed the largest redistributions, while β-integrin and FA kinase showed undetectable redistribution. Vinculin, metavinculin, Src, Crk-associated substrate, and paxillin displayed intermediate degrees of redistribution. Redistributions into membrane fractions were especially prominent, suggesting endosomal mechanisms. Deconvolution microscopy, quantitative colocalization analysis, and Duolink proximity ligation assays revealed that phenylephrine increases the association of FA proteins with early endosomal markers Rab5 and early endosomal antigen 1. Endosomal disruption with the small-molecule inhibitor primaquine inhibits agonist-induced redistribution of FA proteins, confirming endosomal recycling. FA recycling was also inhibited by cytochalasin D, latrunculin B, and colchicine, indicating that the redistribution is actin- and microtubule-dependent. Furthermore, inhibition of endosomal recycling causes a significant inhibition of the rate of development of agonist-induced dVSM contractions. Thus these studies are consistent with the concept that FAs in dVSM cells, embedded in the wall of the aorta, remodel during the action of a vasoconstrictor.
Mechanism of activation of Xenopus CFTR by stimulation of PKC

PKA-mediated phosphorylation of the regulatory (R) domain plays a major role in the activation of the human cystic fibrosis transmembrane conductance regulator (hCFTR). In contrast, the effect of P...
PEGylated Nanoceria as Radical Scavenger with Tunable Redox Chemistry

We report the direct synthesis of cerium oxide nanoparticles (CNPs) in polyethylene glycol (PEG) based solutions with efficient radical scavenging properties. Synthesis of CNPs in PEG demonstrated a concentration dependent (of PEG) redox activity characterized by UV−visible spectroscopy. PEGylated CNPs acted as efficient radical scavengers, and superoxide dismutase (SOD) activity of CNPs synthesized in various concentration of PEG did not reduce compared to bare nanoceria. In addition to superoxide, PEGylated nanoceria demonstrated quenching of peroxide radicals as well. It was observed that the reaction with hydrogen peroxide leads to the formation of a charge transfer complex governed by the concentration of PEG. The stability of the charge transfer complex provides the tunable oxidation state of CNPs. The stability of this complex influences the regenerative capacity of the active 3+ oxidation state of CNPs. The cell viability as well as SOD activity of PEGylated CNPs is compared to those of bare CNPs,...
Automatic optimization of MEEF-driven defect disposition for contamination inspection challenges

Ever-tightened design rules and ensuing aggressive OPC features pose significant challenges for wafer fabs in the pursuit of compelling yield and productivity. The introduction of advanced reticles considerably augments the mask error enhancement factor (MEEF) where progressive defects or haze, induced by repeated laser exposure, continue to be a source of reticle degradation threatening device yield. High resolution reticle inspection now emerges as a rescue venue for wafer fabs to assure their photomask integrity during intensive deep UV exposure. Integrated in the high resolution reticle inspection, a MEEF-driven lithographic detector "Litho3" can be used run-time to group critical defects into a single bin. Previous investigations evinced that critical defects identified by such detector were directly correlated with defects printed on wafer, upon which fab users can make cogent decisions towards reticle disposition and cleaning therefore reduce cycle time. One of the challenges of implementing such detector resides in the lengthy set up of user-defined parameters, from practitioner standpoint, can considerably extend reticle inspection time and inevitably delay production. To overcome this, an automatic simulation program has been written to optimize Litho3 settings based off a pre-inspection in which only default Litho3 values are needed. Upon completion of the pre-inspection, the images are then scanned and processed to extract the optimal Litho3 parameters that are largely dependent upon the feature size characteristics and local MEEF. Thus optimized Litho3 parameters can then be input into the recipe set up to enable a real-time inspection, as such fab user can timely access the defect criticality information for subsequent defect disposition. In the interest of printability validation, such defect information and associated coordinates can be passed onto defect review via XLINK for further analysis. Corresponding MEEF values are also available for all identified critical defects. Through this automatic program the set up time for Litho3 can be reduced by up to 90%. For high capacity production fabs running a pre-inspection is deemed infeasible; this automatic optimization program can also serve as a direct interpretation of any regular reticle inspection even without invoking Litho3 set up, yet in the end provide output in the context of defect criticality. Results acquired from this program were found in good accordance with those from the real-time Litho3 inspection, for both critical and non-critical layers of 90 nm design node. Such capability allows detailed study of defect criticality in relation to its size, defect optical transmittance, residing surface, its proximity to a printing pattern as well as lithography parameters such as NA and sigma. Furthermore, coupling this automatic program with high resolution inspection also assists in determining lithography process window and an indepth comprehension of defect progression mechanism.
A micromechanical model for ductile fracture prediction in ASTM A992 steels

Abstract This paper presents a new micromechanics based ductile fracture initiation criterion for ASTM A992 steels. The proposed criterion is developed using micromechanical study of microvoid growth using computational cell simulations. Parametric study is performed on cylindrical computational cells with an embedded spherical microvoid to describe the effects of stress state, matrix hardening properties and initial void volume fraction on microvoid growth. A micromechanical void growth model and a ductile fracture initiation criterion is proposed for ASTM A992 structural steels based on the parametric study. The model is calibrated and validated using experimental testing on eight notched ASTM A992 steel specimens. It is shown that the predicted ductile fracture initiation strains and fracture initiation locations from the proposed model matched fairly well with the experimental results.
Two-Dimensional Analysis of an Elastic Layer Coupled to a Viscous Fluid

A two-dimensional elastohydrodynamic analysis is performed on a system consisting of a viscous fluid flowing between a sliding soft layer of finity thickness and a tilted flat plate. The behavior of a soft layer subject to a distributed contact pressure is described in detail. Green's unctions are obtained for each Fourier coefficient of the distributed applied pressure, utilizing the additive property of linear elasticity theory The resulting equations are numerically evaluated for some typical cases. As a function of the contact dimension, calculations are performed for the critical thickness of the layer beyond which the deformed shape essentially resembles that of the layer having an infinite thickness, in the case of uniformly applied pressure. We also investigate the effect of layer thickness on the hydrodynamics, which illustrates that conditions in which the infinite half-space assumptions can be justified are highly limited. The findings of this paper have direct application to the modeling of chemical mechanical planarization (CMP).
Phylogenetic Characterization of the MIP Family of Transmembrane Channel Proteins

The ubiquitous major intrinsic protein (MIP) family includes several transmembrane channel proteins known to exhibit specificity for water and/or neutral solutes. We have identified 84 fully or partially sequenced members of this family, have multiply aligned over 50 representative, divergent, fully sequenced members, have used the resultant multiple alignment to derive current MIP family-specific signature sequences, and have constructed a phylogenetic tree. The tree reveals novel features relevant to the evolutionary history of this protein family. These features plus an evaluation of functional studies lead to the postulates: (i) that all current MIP family proteins derived from two divergent bacterial paralogues, one a glycerol facilitator, the other an aquaporin, and (ii) that most or all current members of the family have retained these or closely related physiological functions.
Indian Hedgehog Gene Is a Target of the Bone Morphogenetic Protein Signaling Pathway

Bone morphogenetic proteins (BMPs), a large subgroup of the transforming growth factor-beta family of growth factors, are key mediators of many fundamental processes in embryonic development. The BMP target genes mediating these effects and the mechanism of their selective regulation are poorly characterized. In this study, we used a chromatin immunoprecipitation-based gene cloning method to identify BMP target genes in a mouse embryonic carcinoma cell line. We identified the Indian hedgehog (Ihh) gene as a target of BMP signaling. Both reporter and reverses transcription-PCR assays revealed that Ihh is up-regulated in embryonic cells upon BMP treatment. The BMP response element of the Ihh promoter contains multiple GC-rich motifs known as the "Mad/Medea binding box" found in the Drosophila tinman gene and in the mouse Id1 gene. DNA binding studies revealed that Smad4 binds to these GC-rich motifs. These findings indicate that BMP stimulates Ihh expression. We also suggest expression of the Ihh gene, which contains multiple Smad binding sites, might be finely regulated by a gradient of BMP concentrations.
Growth of high-aspect ratio horizontally-aligned ZnO nanowire arrays

A method of fabricating horizontally-aligned zinc-oxide (ZnO) nanowire (NW) arrays with full control over the width and length is demonstrated. SEM images reveal the hexagonal structure typical of zinc oxide NWs. Arrays of high-aspect ratio horizontal ZnO NWs are fabricated by making use of the lateral overgrowth from dot patterns created by electron beam lithography (EBL). An array of patterned wires are lifted off and transferred to a flexible PDMS substrate with possible applications in several key nanotechnology areas.
GROWTH FACTOR REQUIREMENTS OF TWO STRAINS OF SPHAEROTILUS DISCOPHORUS.

The relatively complex growth-factor requirements of two strains ofSphaerotilus discophorus, strains 31 and 32, have been elucidated. In addition to thiamin and biotin which are required by other strains ofS. discophorus, the two strains must be supplied also with adenine or guanine and with cyanocobalamin for growth in a glucose — Casamino Acids — mineral salts medium. The cyanocobalamin can be replaced by methionine but only if relatively large amounts of this amino acid, 100 µg or more per ml, are added to the medium. The methionine requirement of the two strains is approximately 3 times greater than that of otherS. discophorus strains.
Arnold-Chiari malformation. Report of four cases with contamination of the central nervous system by amniotic contents

Four patients with the Arnold-Chiari malformation had massive prenatal contamination of the spinal cord and brainstem (and also of the cerebral ventricles in one case) by amniotic squamous cells and lanugo hair, which had entered through open meningomyeloceles. Amniotic contents were present in the subarachnoid space, central canal, fourth ventricle, and aqueduct and were also embedded in neural tissue, causing severe gliosis, fibrosis, and blockage. The mechanism of the complication and its implications in the prognosis of patients with the Arnold-Chiari malformation are discussed.
The positive Ions from hot metals

It is well known that when a metal wire or strip is heated for the first time there is a large emission of positive ions from it at a comparatively low temperature. This emission takes place even if the wire is carefully cleaned and the heating is carried out in a good vacuum. It decays to a small value under continuous heating in a vacuum, and can be revived to a varying extent by a number of different modes of treatment, such as heating in air, or in a bunsen flame, or by subjection to high pressure. Very different conclusions as to the nature of these ions have been reached by different experimenters. One view, which has, perhaps, had more advocates than any other, is that the ions consist of positively charged atoms or molecules of various gases evolved by the hot substances. For several years I have suspected that these ions would turn out to be atoms or molecules of the commoner alkali metals which are present in the heated metals as impurities. The experiments to be described were undertaken in the hope of deciding the question in a definite manner. The direct and obvious way of attacking the problem is to determine the specific charge ( e / m ) of the carriers. Since the value of the corresponding quantity for the standard chemical element in electrolysis is known, this is equivalent to measuring the electric atomic (or equivalent) weight ( m /H). I have already made experiments with a large number of metallic substances in this way, partly in collaboration with Mr. Hulbirt. The results showed that the electric atomic weight of the ions was of the order of 30 for the 14 different substances tested, but the measurements were not sufficiently exact to determine with certainty whether the ions were atoms of sodium and potassium or molecules of some of the commoner gases, such as carbon monoxide. The electric equivalent weight of CO+ is 28, and is thus intermediate between Na+ (23·05) and K+ (39·1). There are a number of other alternative constituents which suggest themselves.
Poly(ethylene glycol) Amphiphiles: Surface Behavior of Biotechnical Significance§

The interfacial behavior of surface localized, poly(ethylene glycol) (PEG) esterified fatty acid amphiphiles was comparatively studied at microparticle surfaces via phase partition and at flat surfaces via in situ null ellipsometry. Ellipsometry was performed on methylsilane (MeSi), phosphatidic acid (PA), and phosphatidylcholine (PC) coated silica slides, while human erythrocyte and PC liposomes were subjected to partition in aqueous PEG, dextran two-phase systems. Analogous results from both methods suggest that PEG−amphiphile adsorption can be relatively independent of the underlying surface. Ellipsometry indicated that members of a series of PEG-fatty acid esters of the type Ci:j−EO151 (16 ≤ i ≤ 18, 0 ≤ j ≤ 2) adsorb similarly at MeSi-, PC-, and PA-coated surfaces, reaching a plateau (≈0.1 PEG chains·nm-2) independent of micelle formation. When normalized for acyl tail hydrophobicity, PEG−amphiphile adsorption is relatively noncooperative and independent of the acyl tail; saturation is largely determi...
On the initiation of discontinuous precipitation

Abstract It is proposed that a general criterion for distinguishing between alloys in which discontinuous precipitation can occur and those in which it does not, is the degree to which the solute elements tend to segregate at grain boundaries. By considering the tendency for a boundary segment to bulge it has been demonstrated that for CuSb alloys the criterion is fulfilled and that the general trends in other alloys are consistent with it. The necessary information is presently unavailable for more quantitative tests.
Simulation tools for future interferometers

For the design and commissioning of the LIGO interferometer, simulation tools have been used explicitly and implicitly. The requirement of the advanced LIGO interferometer is much more demanding than the first generation interferometer. Development of revised simulation tools for future interferometers are underway in the LIGO Laboratory. The outline of those simulation tools and applications are discussed.
Phosphorus Fractions in Soil and Water of Aquaculture Ponds Built on Clayey Ultisols at Auburn, Alabama

Phosphorus fractions in soil and water were determined for a 22-year-old, 400m2 fish pond constructed on clayey Ultisols at Auburn, Alabama. This pond had been used in pond fertilization and fish feeding experiments each year. Total phosphorus concenlrations in bottom soil were greater in deep water than in shallow water areas. Highest concentrations of phosphorus occurred in the 5–10 cm soil layer, but phosphorus had accumulated above its original concentration to depths of 20 to 45 cm (x= 36.8 cm). The soil phosphorus accumulation rate was 2.68 g/m2 per year. Less than 1% of the total phosphorus in soils from three ponds was extractable in distilled water or 0.5 M NaHCO3. Sequential extraction with 1 M NH4Cl, 0.5 N HCl, and 0.1 N NaOH removed less than 25% of the total phosphorus. The loosely-bound phosphorus fraction (1 M NH4Cl extractable) was 0.4 to 5.2% of the extractable phosphorus. The ability to adsorb phosphorus decreased and the capacity to release phosphorus increased in pond soils as total phosphorus concentration increased. After 22 years of aquacultural production, phosphorus adsorption sites in a pond soil were only about half-saturated. Although soluble phosphorus accounted for 37% of the phosphorus in pond water, only 7% of the total phosphorus in pond water was soluble reactive phosphorus. The phosphorus pool in pond soil was over 500 times greater than that of pond water, but most of the soil phosphorus was strongly adsorbed and unavailable.
THE LS-ANTIGEN OF VACCINIA IV. CHEMICAL ANALYSIS OF LS AND THE EFFECT OF CHYMOTRYPSIN ON LS

Pure LS-antigen of vaccinia contains 15.8 per cent N and 50.6 per cent C. These analytical data together with the absence of lipids, phosphorus, nucleic acid, and glucosamine in preparations of the antigen confirm the protein nature of the substance. The action of proteolytic enzymes on LS offers further confirmation of the protein character of the antigen. Both the L- and S-activities of the antigen are destroyed by digestion with papain. The effects of crystalline chymotrypsin on LS-antigen are particularly interesting for, under proper conditions, this enzyme destroys the serological activity of the S-portion of the molecule without affecting the L-portion. This newly prepared degradation product of LS, called LS'', contains the same amount of N as the native substance but unlike LS, it forms needle-shaped crystalloids.
Coupled-cluster studies of singlet propynylidene

The equilibrium geometry of singlet propynylidene is studied with high level coupled-cluster methods and moderate size to large basis sets. The calculations uniformly predict that the equilibrium structure is distorted from the C2v 1,3 biradical picture, with CC bond lengths that differ by approximately 0.1 A. Despite this, the barrier calculated for automerization between the two equivalent Cs minima on the potential surface is less than 1 kcal mol-1. Hence, it is likely that experimental studies of singlet propynylidene will be consistent with the dynamically averaged C2v symmetry of the molecule.
Nanostructured TiO2 Films with Controlled Morphology Synthesized in a Single Step Process: Performance of Dye-Sensitized Solar Cells and Photo Watersplitting

Nanostructured titanium dioxide (TiO2) films were synthesized with controlled morphology and thickness in an ambient pressure single-step flame aerosol reactor (FLAR) for use in water splitting photocells and dye-sensitized solar cells. Two different morphologies were studied: a granular morphology and a highly crystalline columnar morphology. The granular morphology consisted of nanoparticles, approximately 10 nm in diameter, aggregated into fractal structures on the substrate. The granular morphology contained a large number of grain boundaries and other interfacial defects. The columnar morphology consisted of single-crystal structures, approximately 85 nm in width, oriented normal to the substrate. The well controlled deposition process was used to deposit films with thicknesses in the range from 98 nm to 12 μm to establish the relationship to water splitting and dye-sensitized solar cell performance. It was found that for watersplitting there was an optimum thickness (∼1.5 μm), which was a tradeoff ...
Nepal Mandala: A Cultural Study of the Kathmandu Valley.

The Description for this book, Nepal Mandala: A Cultural Study of the Kathmandu Valley. (2 Vols.), will be forthcoming.
CELLULAR RESPONSES TO NITRIC OXIDE : ROLE OF PROTEIN S-THIOLATION/DETHIOLATION

Nitrosothiols, the product of the reaction of nitric oxide-derived species (NOx) with thiols, participate in both cell signaling and cytotoxic events. Glutathione has recently been shown to modulate nitrosothiol-mediated signal transduction and to protect against NOx-mediated cytotoxicity. We have investigated the role of protein S-thiolation/dethiolation as a potential mechanism by which glutathione regulates nitrosothiol signaling and toxicity. Our data show that exogenous sources of NOx decreased both free protein thiol and total glutathione levels in endothelial cells. The decrease in glutathione levels could not be accounted for by formation of S-nitrosoglutathione (GSNO) since borohydride treatment of the nonprotein fraction of cell extracts did not restore glutathione levels, whereas borohydride treatment of protein-containing cell extracts led to recovery of glutathione levels. The NOx-mediated decrease in glutathione and protein thiol content was correlated with an increase in protein mixed disulfide formation, as measured by the incorporation of [35S]glutathione into cellular proteins. [35S]glutathione was incorporated into proteins via a covalent disulfide bond since dithiothreitol removed the radiolabel from cellular proteins. The withdrawal of the exogenous NOx source led to recovery of free protein thiol and cellular glutathione levels, which correlated with the dethiolation of proteins. Dethiolation required the action of the glutathione redox system since 1, 3-bis(2-chloroethyl)-1-nitrosourea, an inhibitor of glutathione reductase, blocked both the recovery of glutathione levels and the dethiolation of proteins. These results suggest that exposure of cells to NOx does not lead to accumulation of GSNO but rather stimulates protein S-thiolation, a mechanism which may have important implications with respect to nitrosothiol signaling and toxicity.
Cynomolgus Monkey Model for Experimental Q Fever Infection

A subhuman primate model was developed for study of the pathogenesis of infection with Coxiella burnetii. Cynomolgus monkeys (Macaca fascicularis) that were exposed to 10(5) mouse median infectious intraperitoneal doses of C. burnetii in a small-particle aerosol developed clinical signs of illness and pathologic changes characteristic of Q fever infection in humans. All monkeys had radiologic evidence of pneumonia by day 9. Antibodies to C. burnetii were detectable by the indirect fluorescent antibody test by day 7. These data indicate that the cynomolgus monkey is a suitable model for study of the pathogenesis of Q fever infection and may prove valuable in the evaluation of C. burnetii vaccines.
Quantification of volatile organics in soil aging experiments using fourier transform infrared spectroscopy.

On-line Fourier transform infrared (FT-IR) spectroscopy was applied to monitor the concentration of halogenated volatile organic compounds in a sample-preparation process that simulates long-term, slow accumulation of contaminants in soils (i.e., aging). Artificial aging is conducted by circulating a supercritical fluid solution containing the contaminant(s) of interest through a packed soil column. Mid-infrared spectra of several volatile halocarbons were measured in supercritical Xe and CO2 to evaluate possible interferences from the strong absorption of CO2. Although some of the C–X bands were partially masked in supercritical CO2, all of the compounds studied had distinct spectral features in the region 1400–700 cm−1 and could be monitored in either solvent. Quantitative measurements of halogenated volatile organics in supercritical CO2 were demonstrated with CCl4. Excellent results were obtained over the range 7–280 mM. Representative artificial aging experiments were conducted on two test soils using CCl4 as the contaminant. On-line (FT-IR) estimates of the aged soil concentrations were 1.3–4.4 times higher than off-line concentrations obtained by gas chromatography/mass spectrometry. The discrepancies were primarily ascribed to post-aging losses that occurred during depressurization and subsequent sample handling. FT-IR spectroscopy is shown to be a powerful tool for monitoring soil loading behavior and for developing artificial aging protocols.
Assessing internal epicormic dynamics in Quercus alba L. using CT scanning: the strong effects of shoot development and tree growth relative to progeny level genetic variation

Epicormic branches can be a serious silvicultural problem in many Quercus species because of the potential reduction in log value associated with their occurrence. The phenomenon is also problematic for tree improvement since the genetic component of epicormic branching has not been well quantified. The strong influence of ontogeny on epicormic development in Quercus is well established; however, the long-standing assumption that genetic variation also influences epicormics has not been rigorously tested. With trees from two, 25-year-old Quercus alba L. progeny tests in IN, USA, we used computed tomography scanning to characterize internal epicormic development. We sampled trees from upper and lower crown classes of families that had been classified as having low, medium and high numbers of epicormic sprouts. We also measured an array of variables related to growth and competition with the objective of assessing the relative impacts of genetics and vigor on epicormic development. Using generalized linear and linear mixed models, we found that ontogenetic and vigor variables were strongly associated with epicormic structure and development, and that the genetic effect was negligible. The total number of epicormics was most significantly influenced by the number of sequential branches that bore epicormics (p < 0.001) and the proportion of undeveloped epicormics was most significantly influenced by diameter increment (p < 0.001). We propose that a strong focus on individual tree vigor and form in tree improvement could minimize the impact of epicormic branching in Q. alba trees.
The influence of the liquid-to-solid transitions on the changes of macromolecules from disorder to order

When crystallizing macromolecules, one needs to recognize that they are sufficiently long to connect neighboring phases. This coupling between the phases is the reason that on ordering, practically all polymers develop a globally metastable, semicrystalline structure, consisting of multiple phases with different degrees of mobility. The ordered and amorphous phases are separated by nanophases of strained segments of molecule of nanometer dimensions, consisting of rigid-amorphous fractions, RAFs, which soften, above, within, or below the often very broad melting range of the ordered phases. Thus, ordering of a melt of macromolecules causes significant changes in the remaining amorphous phases. A summary of the various phases is given in terms of their structures, molecular vibrations, and large-amplitude motion as they influence the glass and order-disorder transitions. This is followed by a description of the limits of the classical nucleation theory of crystals when applied to macromolecules. Discussed in detail are the problems in primary and secondary nucleation which arise from the presence of RAFs. Special macromolecular nucleation processes that needed to be considered are the self-nucleation on cooling from above the melting temperature or on heating from above the glass transition temperature, and the molecular nucleation causing molar mass segregation on ordering. Finally, the glass transitions of the phases of various sizes and degree of order are discussed on hand of selected, pertinent examples.
Exploring burnout among university faculty: incidence, performance, and demographic issues

Abstract This study examines burnout and related issues among 265 university faculty members. The study estimates the percentage of incidence of highest levels of burnout is at half the rate of the general workforce. Female faculty members have significantly higher mean scores on emotional exhaustion than males, while male faculty have higher scores on depersonalization. Significant differences were not found across race/ethnicity groups but age is inversely correlated to emotional exhaustion. Burnout shows significant correlations with numbers of students taught, time invested in various activities, and numerical student evaluations. Suggestions are given to administrators for using a preventive strategy to anticipate burnout, rather than relying on reactive techniques, once it has occurred.
Transport of Particulate Organic Carbon by the Mississippi River and Its Fate in the Gulf of Mexico

This study was designed to determine the amount of particulate organic carbon (POC) introduced to the Gulf of Mexico by the Mississippi River and assess the influence of POC inputs on the development of hypoxia and burial of organic carbon on the Louisiana continental shelf. Samples of suspended sediment and supporting hydrographic data were collected from the river and >50 sites on the adjacent shelf. Suspended particles collected in the river averaged 1.8±0.3% organic carbon. Because of this uniformity, POC values (in μmol l−1) correlated well with concentrations of total suspended matter. Net transport of total organic carbon by the Mississippi-Atchafalaya River system averaged 0.48×1012 moles y−1 with 66% of the total organic carbon carried as POC. Concentrations of POC decreased from as high as 600 μmol l−1 in the river to 35% along the shelf at ≥10 km from the river mouth. River flow was a dominant factor in controlling particle and POC distributions; however, time-series data showed that tides and weather fronts can influence particle movement and POC concentrations. Values for apparent oxygen utilization (AOU) increased from ∼60 μmol l−1 to >200 μmol l−1 along the shelf on approach to the region of chronic hypoxia. Short-term increases in AOU were related to transport of more particle-rich waters. Sediments buried on the shelf contained less organic carbon than incoming river particles. Orgamic carbon and δ13C values for shelf sediments indicated 3 that large amounts of both terrigenous and marine organic carbon are being decomposed in shelf waters and sediments to fuel observed hypoxia.
A numerical study of the fluctuating flowfield of a uniformly loadedpropeller.

A simple method has been developed for calculating the flowfield of a finite-bladed propeller in the forward flight regime. This method is based upon classical propeller vortex theory and the Fourier analysis of the resulting induced velocities. A numerical study of the harmonic content of the flowfield has been carried out for a uniformly loaded propeller for representative blade numbers and operating advance ratios. The results indicate that the fluctuating part of the velocity components is appreciable as compared to the steady, or timeindependent, part for low blade numbers and/or high advance ratios. The total inflow at the propeller blades has also been calculated and correlated with the known analytical results for the steady inflow at the propeller plane.
Structure and tension of the boundary line between amphiphilic layers

Abstract The structure and tension of the region of contact where an oil phase, a water phase and a microemulsion phase meet, is theoretically investigated. The analysis has as a starting point a Landau-theory-like expression for the free energy in which, besides the usual gradient of the density squared term, a term proportional to the second derivative of the density squared is present. The coefficient of the squared gradient term is taken to be negative in the microemulsion phase (cf. G. Gompper and M. Schick, Phys. Rev. Lett. 65 (1990) 1116). In a closely related model, we show that a first order wetting transition exists at which point infinitely many (n = 0, 1, 2,…) surface phases can coexist, each described by the presence of a different thickness (ln = (2n + 1)l0) of the microemulsion phase between the oil and water phase. This situation physically describes the coexistence of layers of amphiphilic molecules with different thicknesses between a water and an oil bulk phase, the thickness of one amphiphilic layer being equal to l0. We present the calculation of the density profile and the boundary tension of the contact region of a coexisting n = 0 and n = 1 surface phase, e.g. between the oil-water interface with a single amphiphilic layer present and the oil-water interface where three amphiphilic layers are present. Also, an approximate analysis is made for the calculation of the boundary tension between surface phases consisting of three or more amphiphilic layers.
Kinetic mixing as the origin of a light dark-gauge-group scale

We propose a model in which supersymmetric weak scale dark matter is charged under a $U(1{)}_{d}$ dark gauge symmetry. Kinetic mixing between $U(1{)}_{d}$ and hypercharge generates the appropriate hierarchy of scales needed to explain PAMELA and ATIC with a GeV scale force carrier and DAMA (or INTEGRAL) using the proposals of inelastic (or, respectively, exciting) dark matter. Because of the extreme simplicity of this setup, observational constraints lead to unambiguous determination of the model parameters. In particular, the DAMA scattering cross section is directly related to the size of the hypercharge D-term vacuum expectation value. The known relic abundance of dark matter can be used to fix the ratio of the dark sector coupling to the dark matter mass. Finally, the recent observation of cosmic ray positron and electron excesses can be used to fix the mass of the dark matter through the observation of a shoulder in the spectrum and the size of the kinetic mixing by fitting to the rate. These parameters can be used to make further predictions, which can be checked at future direct detection, indirect detection, as well as collider experiments.
Mesoderm induction in Xenopus is a zygotic event regulated by maternal VegT via TGFbeta growth factors

The maternal transcription factor VegT is important for establishing the primary germ layers in Xenopus. In previous work, we showed that the vegetal masses of embryos lacking maternal VegT do not produce mesoderm-inducing signals and that mesoderm formation in these embryos occurred ectopically, from the vegetal area rather than the equatorial zone of the blastula. Here we have increased the efficiency of the depletion of maternal VegT mRNA and have studied the effects on mesoderm formation. We find that maternal VegT is required for the formation of 90% of mesodermal tissue, as measured by the expression of mesodermal markers MyoD, cardiac actin, Xbra, Xwnt8 and alphaT4 globin. Furthermore, the transcription of FGFs and TGFbetas, Xnr1, Xnr2, Xnr4 and derriere does not occur in VegT-depleted embryos. We test whether these growth factors may be endogenous factors in mesoderm induction, by studying their ability to rescue the phenotype of VegT-depleted embryos, when their expression is restricted to the vegetal mass. We find that Xnr1, Xnr2, Xnr4 and derriere mRNA all rescue mesoderm formation, as well as the formation of blastopores and the wild-type body axis. Derriere rescues trunk and tail while nr1, nr2 and nr4 rescue head, trunk and tail. We conclude that mesoderm induction in Xenopus depends on a maternal transcription factor regulating these zygotic growth factors.
The impact of a vortex ring on a wall

The flow induced by a vortex ring approaching a plane wall on a trajectory normal to the wall is investigated for an incompressible fluid which is otherwise stagnant. The detailed characteristics of the interaction of the ring with the flow near the surface have been observed experimentally for a wide variety of laminar rings, using dye in water to visualize the flow in the ring as well as near the plane surface. Numerical solutions are obtained for the trajectory of the ring as well as for the unsteady boundary-layer flow that develops on the wall. The experimental and theoretical results show that an unsteady separation develops in the boundary-layer flow, in the form of a secondary ring attached to the wall. A period of explosive boundary-layer growth then ensues and a strong viscous-inviscid interaction occurs in the form of the ejection of the secondary vortex ring from the boundary layer. The primary ring then interacts with the secondary ring and in some cases was observed to induce the formation of a third, tertiary, ring near the wall. The details of this process are investigated over a wide Reynolds number range. The results clearly show how one vortex ring can produce another, through an unsteady interaction with a viscous flow near the wall.
Medical Robotics in Surgery

This article provides an overview of medical robotic systems and technologies. After introduction of the basic concepts of medical robotics, and introducing a classification of medical robotic systems based on the operator interaction modality, the article discusses the general application areas of robotics technology in medical applications. The presentation is concluded with a discussion on the major research challenges in the area. Keywords: robotics; medical robotics; human-computer interaction; telesurgery; image-guided surgery; mimimally invasive surgery; medical devices; teleoperation; telerobotics; supervisory control; shared control
Persistence of a drug-personality interaction in psychiatric outpatients.

CLINICAL drug trials with psychiatric outpatients usually span brief time periods. Investigators rarely follow up such trials. Apparently only one previous study reported an objective and comprehensive follow-up of a clinical trial of mild tranquilizers.1 Unfortunately it used different measures during the clinical trial and at follow-up, and psychiatric status for the two periods could not be compared. This paper reports a follow-up four months after the end of a double-blind trial of diazepam (Valium).a-4-t The 2-week trial indicated that a personality characteristic (Acquiescence) and medication had significant joint, or interactive, effects upon outcome. Patients had been classified as High or Low Acquiescers by their frequency of agreement with 35 glib generalizations from the Bass Social Acquiescence Scale.5$ After twa weeks of treatment Low Acquiescers had improved more on drug than on placebo, while High Acquiescers had improved more on placebo than on drug. Figure 1 depicts the interaction pattern on a typical criterion. The research questions in the follow-up phase concerned: (1) the persistence of the medication-personality interaction; (2) the effects of the clinical trial upon subsequent treatment and clinical progress.
Rheological characterization and full 3D mold flow simulation in multi-die stack CSP of chip array packaging

According as high density packaging options such as 2 or more die stacking or package stacking technologies are developed, the major mold process related quality concerns such as incomplete mold, exposed wires and wire sweeping are increased because of their narrow spaces between die top and mold surface and increased wiring density. So, to verify those concerns, full 3D rheokinetic simulation of mold flow has been investigated for 3 die stacking structure of 4 /spl times/ 4 mold array, 294LD case. The rheological parameters of commercial epoxy molding compound (EMC) were acquired through the slit-die rheometer and DSC (differential scanning calorie-meter) analysis. It is found that the severe void problem is one of the challenging factors in the thin and multi-die stack packaging to determine its manufacturability. To investigate the effect of different gate types, the molding options with four different gates were evaluated. The center gate showed most severe voids but corner gate showed relatively better void performance. But in case of the wire sweeping experiment and prediction results, the center gate type had less wire sweeping than the corner gate type. In the rheological simulation results, the corner gate case indicated increased velocity, shear stress and mold pressure near to the gate inlet and final filling zone. The experimental case study and the mold filling simulation showed good match on the mold external void and wire sweeping related prediction.
Reconstruction of false spring occurrences over the southeastern United States, 1901-2007: an increasing risk of spring freeze damage?

Near-record warmth over much of the United States during March 2007 promoted early growth of crops and vegetation. A widespread arctic air outbreak followed in early April, resulting in extensive agricultural losses over much of the south-central and southeastern US. This 'false spring' event also resulted in widespread damage to newly grown tissues of native deciduous forest species, shown by previous researchers to have had measurable effects on the terrestrial carbon cycle. The current study reconstructed the historical occurrence of false springs over most of the southeastern quarter of the conterminous US (32–39°N; 75–98°W) from 1901 to 2007 using daily maximum and minimum temperature records from 176 stations in the Global Historical Climatology Network database, and enhanced vegetation index (EVI) data derived from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations. A false spring index was derived that examined the timing of the start of the growing season (SGS), or leaf emergence, relative to the timing of a potentially damaging last hard freeze (minimum temperature ≤ − 2.2 °C). SGS was modeled for the domain by combining EVI data with ground-based temperature 'degree day' calculations reflecting the rate of springtime warming. No significant area-wide, long-term SGS trend was found; however, over much of a contiguous region stretching from Mississippi eastward to the Carolinas, the timing of the last hard freeze was found to occur significantly later, this change occurring along with increased frequency of false springs. Earlier last hard freeze dates and decreased frequency of false springs were found over much of the northwestern part of the study region, including Arkansas and southern Missouri.
Glitch Control with Dynamic Receiver Threshold Adjustment

A novel method to treat crosstalk induced glitches on local interconnects is presented. Design irregularities and manufacturing defects in system-on-chip interconnects may result in spurious electrical events that impact the reliability of the interconnect infrastructure. Conventional repeater insertion methods prove to be space and power demanding. The proposed method acts by dynamically adjusting the threshold voltage of the receiving gate without breaking the line in multiple segments. A comparative study is presented that supports the applicability of the approach
Considerations of community noise impact on hearing health

Potential contributors to hearing impairment due to community noise sources are discussed. These include: (a) the predisposing effect of moderately intense (70 dBA) average background sound levels; (b) the "effective quiet" concept that identifies sound levels that neither cause a temporary threshold shift (TTS) nor impede recovery from TTS; (c) community noise source stress reaction as a further predisposing influence during dangerously high level noise exposures; and (d) attitudinal factors involved in noise experience discussed in terms of a "pleasure principle."
New transfer methods for client-server traffic in ATM networks

This paper presents new transfer schemes for client-server traffic over ATM networks, with the objective of achieving a bounded transmission time of about one second for as many connection requests as possible. We evaluate via simulations the performance of these new schemes in terms of network utilization, cell loss ratio, and transmission time. The simulation results show that these schemes provide effective means of supporting client-server traffic with quasi-real time requirements.
Racial Lessons: Parental Narratives and Secondary Schooling Experiences Among Second- and Third-Generation Mexican Americans

Research on Mexican American educational incorporation has consistently shown educational stagnation between the second and third generations. Whether educational stagnation is attributable to generational differences in parental narratives that affect the academic motivation between members of the second and third generation, or negative school conditions that lead to their low educational attainment regardless of generational status, remains in question. Utilizing 41 interviews, I examine how the parental narratives and high school experiences of Mexican Americans differ by generational status, that is, for the second and third generation. My findings demonstrate that both second- and third-generation participants received encouraging parental messages to pursue higher education, regardless of parents’ nativity. Consequently, generational differences in parental narratives inadequately account for educational stagnation among Mexican Americans. Furthermore, my findings substantiate the role of educator messages in shaping Mexican Americans’ educational trajectories. I find no generational differences in how Mexican Americans perceived and responded to the racialized treatment in high school, whether they attended a diverse or majority-Latino institution. Specifically, the racialized content of educator messages directed toward Mexican Americans negatively affected their academic engagement and whether they enrolled in college-preparatory classes. In all, I argue that educator messages are equally or more important than parental narratives in shaping Mexican American educational incorporation. My findings support a longer line of research calling attention to the importance of educators and their significant influence over students’ educational trajectories.
Next generation power amplifiers for wireless communications - squeezing more bits out of fewer joules

This paper covers the limitations of current handset power amplifier design. The specific limitations on efficiency and linearity are addressed, and several of the most promising techniques for improvements are discussed.