cssi/SciSciGPT-SciSciNet huggingface dataset:
Distributed computing applied to a VLSI chip

The authors describes an adapter card that is designed to implement the distributed computing concepts in a very-large-scale-integrated (VLSI) chip. This design combines the advantages of both distributed computing implementation and VLSI technology for optimum speed and efficiency. The author also describes the state machines that are used in the VLSI chip to support the data rates required by the adapter card housing the VLSI chip. The adapter card is used to communicate with the NCP (network control program) to transfer data between the main store of a communication controller and the communication network. >
Nodal and other properties of the second eigenfunction of the Laplacian in the plane

Rules are established for the intersection of nodals at a boundary in the plane relevant to the second eigenfunction of the Laplacian. Employing these results together with regularity theorems related to odd reflection of solutions of the Helmholtz equation, as well as a variation of C.S. Lin's analysis, the following theorem is revisited: The nodal curve of the second eigenstate of the Laplacian for bounded convex domains in the plane, with Dirichlet boundary conditions, is a simple curve that intersects the boundary in two distinct points. Application is made to the regular convex polygons with C n , n ≥ 2, symmetry and to convex billiards with smooth boundaries.
Tinea capitis in aboriginal children at Maningrida, Northern Territory, Australia. A variant of Microsporum canis.

Summary A high incidence od endemic tinea capitis was found among children at the Aboriginal settlement of Maningrida, Arnhem Land, on the northern coast of Australia some 400 km east of Darwin. The cause was a variant of Microsporum canis which will be referred to as the‘Maningrida’type. It was isolated form 21 (25.3%) brush samples taken form the scalps of 83 Aboriginal Children. There were diffuse, or scattered fine white scaling lesions with minimal hair loss. Clinically these infections could not be distinguished from endothrix tinea capitis caused by Trichophyton tonsurans or Trichophyton violaceum which occur frequently in Aboriginal children in South Australia. No cases of endothrix tinea catitis were found in Aboriginal children in Darwin or in the other settlements which were visited in Arnhem Land. The‘Maningrida’type of M. canis developed as a small spidery colony with a central downy to powdery fuftm which in five to six days produced many typical macroconidia. Young cultures Produced little or no pigment, but later developed a buff or pale brownish pigment. Four cats and two dogs at maningrida were shown to be reservoirs of the variant of M. Canis. No Strains of the typical M. canis with its golden yellow pigment were isolated at maningrida.
Human kidney thiopurine methyltransferase. Photoaffinity labeling with S-adenosyl-L-methionine.

Abstract Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of heterocyclic and aromatic sulfhydryl compounds such as the thiopurine drug 6-mercaptopurine (6-MP). TPMT activity in human tissue is regulated by a common genetic polymorphism, and “pharmacogenetic” variation in TPMT activity is an important factor in individual differences in thiopurine drug metabolism, toxicity and therapeutic efficacy. Human renal tissue contains two isozymes of TPMT, Peak I and Peak II, that can be separated by ion exchange chromatography. Our experiments were performed to determine whether S- adenosyl- L -methionine (Ado-Met), the methyl donor for the TPMT reaction, could be used as a photoaffinity ligand for these isozymes as one step in the study of the molecular basis for the TPMT genetic polymorphism. When [3H-methyl]Ado-Met and partially purified preparations of either isozyme of human kidney TPMT were exposed to ultraviolet light at 254 nm, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a 35 kDa protein was the predominant species that was radioactively labeled. The same 35 kDa protein was photoaffinity labeled with [14C-carboxyl]Ado-Met, demonstrating that labeling involved covalent binding of Ado-Met rather than methylation of the protein. TPMT enzymatic activity co-eluted with the 35 kDa protein during sequential DEAE ion exchange, gel filtration and hydroxylapatite chromatography. Inhibitors of TPMT enzymatic activity including S- adenosyl- L -homocysteie , sinefungin, 6-methylmercaptopurine and 3,4-dimethoxy-5-hydroxybenzoic acid inhibited photoaffinity labeling of the 35 kDa protein in preparations of both TPMT Peak I and Peak II isozymes in a concentration-dependent fashion, as did 6-MP, the methyl acceptor substrate for the TPMT reaction. All of these results were compatible with the conclusion that the 35 kDa protein was TPMT. Photoaffinity labeling of TPMT with [3H]Ado-Met should make it possible to purify the enzyme to homogeneity and to study amino acid sequences at or near its active site.
Influences of Childhood Experiences on Early Childhood Education Students

This qualitative study examined whether or not childhood experiences of the early childhood education students affected their present personal beliefs and pedagogies. A digital survey was filled out by 58 students majoring in Early Childhood Education program. The participants were asked to identify and reflect on their impactful early experiences. The follow-up interviews with two participants were conducted to deepen the reflections on childhood experiences and explore their effects on the present lives of the early childhood educators. The theoretical framework for this study was based on the concept of the experiential continuum originated by one of the most influential American philosopher, John Dewey. The findings suggest that early childhood education students’ early childhood experiences are connected to personal and professional aspects of their lives. The results of this study suggest that despite the potentially changing interpretation of the past, childhood may continuously affect the lives of early childhood education students. These results support the importance of reflecting on students’ own childhoods in teacher preparation programs. Another result of this study was that e arly peer experiences affected teachers’ present lives. Based on the results, s uggestions for the teacher education programs are made. Such suggestions included promoting students to facilitate their reflections regarding childhood experiences via the following questions: “Why am I reflecting on this teaching experience/knowledge the way I am? What within myself, within my own past experiences may be driving me to see what I am seeing, to conclude what I am concluding?” Keywords: childhood experiences, pedagogy, early childhood education, experiential continuum
Evolving hypopituitarism in children with central nervous system lesions

At the time children with suspected hypopituitarism are seen with a subnormal growth rate, it is expected that testing will demonstrate growth hormone (hGH) deficiency. Seven patients with organic CNS lesions--three with histiocytosis X, one with septo-optic dysplasia, one with neonatal meningitis, one with an anterior encephalocele and meningitis, and one with neurofibromatosis who had normal growth hormone concentrations (greater than 7 ng/mL) despite a subnormal growth rate--were studied. Subsequent retesting 0.5 to 4.6 years later demonstrated the development of growth hormone deficiency. Four of the patients had evidence of other pituitary hormone deficiencies at the time of initial testing whereas two subsequently developed other deficiencies. The initial subnormal growth rate in these children may be secondary to their organic CNS lesion or an evolving hypopituitarism, perhaps with deficient somatomedin generation. These studies point out the need for continued observation and retesting in such patients.
Dsl1p, an essential protein required for membrane traffic at the endoplasmic reticulum/Golgi interface in yeast.

To identify novel factors required for ER to Golgi transport in yeast we performed a screen for genes that, when mutated, confer a dependence on a dominant mutant form of the ER to Golgi vesicle docking factor Sly1p, termed Sly1-20p. DSL1, a novel gene isolated in the screen, encodes an essential protein with a predicted molecular mass of 88 kDa. DSL1 is required for transport between the ER and the Golgi because strains bearing mutant alleles of this gene accumulate the pre-Golgi form of transported proteins at the restrictive temperature. Two strains bearing temperature-sensitive alleles of DSL1 display distinct phenotypes as observed by electron microscopy at the restrictive temperature; although both strains accumulate ER membrane, one also accumulates vesicles. Interestingly, the inviability of strains bearing several mutant alleles of DSL1 can be suppressed by expression of either Erv14p (a protein required for the movement of a specific protein from the ER to the Golgi), Sec21p (the γ-subunit of the COPI coat protein complex coatomer), or Sly1-20p. Because the strongest suppressor is SEC21, we proposed that Dsl1p functions primarily in retrograde Golgi to ER traffic, although it is possible that Dsl1p functions in anterograde traffic as well, perhaps at the docking stage, as suggested by the suppression by SLY1-20.
Subtoxic Hepatic Vitamin A Concentrations in Captive Rhesus Monkeys (Macaca mulatta)

Although the rhesus monkey (Macaca mulatta) is a widely used experimental animal, its exact vitamin A requirement is unknown. An amount of 430-3600 IU/d [129-1080 retinol equivalents (RE)] is recommended, largely on the basis of depletion studies. Normal hepatic vitamin A appears to be 1 micromol/g liver. Our goal was to determine hepatic vitamin A concentrations of captive monkeys. Liver autopsy samples from rhesus and marmoset (Callithrix jacchus) monkeys were obtained from the Wisconsin Regional Primate Research Center. The rhesus monkeys consumed a diet with 40 IU (12 RE) retinyl acetate/g. Male and female monkeys consumed an estimated 250 and 175 g diet/d, respectively. Marmosets were fed a powder-based diet consisting of 20 IU (6 RE) retinyl acetate/g. The marmosets consumed an estimated 25 g of the diet/d. Liver samples were extracted and analyzed by HPLC. The vitamin A concentration of the rhesus monkey livers was very high at 17.0 +/- 6.3 micromol/g. The hepatic vitamin A of the marmosets was 1.25 +/- 0.58 micromol/g liver. Histologic examination of the livers revealed Ito cell hypertrophy and hyperplasia in the rhesus monkeys compared with the marmosets. Considering that the natural diet of the rhesus monkey (fruits, seeds, roots and insects) is not high in preformed vitamin A, the vitamin A content of the diet appears excessive, supplying four times the NRC recommendation and resulting in high liver stores.
Use of Vacuum Blood Collection Tubes for Chickens

Abstract A technique for collecting blood samples from chickens utilizing the vacuum tube method presently used in human and large-animal blood collections is described. This procedure allows for repeated short-interval bleedings from the same vein or from the heart of an individual chicken.
Elastodynamic model for large-diameter end-bearing shafts

ABSTRACT The dynamic response of large-diameter end-bearing cylindrical shafts is studied. First, the popular plane-strain model of Novak is reviewed and its limitations are discussed. An improved model is then developed which, while retaining the simplicity of the original model, accounts for the third dimension by considering the normal and shear stresses acting on the upper and lower faces of a horizontal soil slice. These stresses are incorporated in the analysis by implementing a dynamic Vlasov-Leontiev approximation based on integrating the governing equations over the thickness of the soil layer. It is shown that this operation leads to a set of elastodynamic equations which are similar to those in the plane-strain model, yet properly incorporate the salient 3-D effects. Explicit closed-form solutions are obtained for: (i) the dynamic soil reaction along the shaft; (ii) the dynamic impedance of the shaft; (iii) the displacement field in the soil; and (iv) the dynamic interaction factors between neighboring shafts. Both vertical and lateral oscillations are analyzed for single and grouped shafts. Results are presented in terms of dimensionless graphs which highlight the importance of soil-foundation interaction on the response. It is shown that the proposed model avoids the limitations of the plane strain model.
N-Propionylated group B meningococcal polysaccharide glycoconjugate vaccine against group B meningococcal meningitis

Abstract Although group B Neisseria meningitidis is responsible for a significant amount of meningococcal meningitis, its capsular polysaccharide is precluded from the current vaccine because of its poor immunogenicity. This phenomenon is attributable to structural mimicry between the group B meningococcal polysaccharide (GBMP) and human tissue antigens. One simple way to avoid this problem is to use as a vaccine a synthetic N -propionylated (NPr) form of the GBMP, which when conjugated to tetanus toxoid (IT, induces, in mice, high titers of bactericidal antibodies against all group B meningococci. Fortuitously, the major population of NPr GBMP-specific antibodies, even though not cross-reactive with the GBMP, contains all the protective activity. Only a minor population of GBMP cross-reactive antibodies are produced, but even the level of these antibodies can be significantly reduced by adjuvant manipulation. Thus the NPr GBMP mimics a highly conserved capsule-associated epitope that could be the basis of a potential vaccine against group B meningitis. To further define this protective epitope, a series of GBMP-specific monoclonal antibodies of the IgG isotype were produced using an (NeuPr) ≈35 −35TT conjugate vaccine. Unlike GBMP-specific antibodies, which recognize epitopes found only on the extended helical form, some of those secreted by the NPr GBMP-specific clones were also able to recognize short (random coil) segments of the NPr GBMP However, only those antibodies specific for the extended helical epitopes were protective as defined by bactericidal assays or passive protection experiments.
Theoretical and Numerical Predictions of Burst Pressure of Pipelines

It is known that the Tresca yield theory predicts a lower bound of burst pressure, whereas the von Mises yield theory provides an upper bound of burst pressure of pipelines. To accurately predict the burst pressure, the present authors [1] recently developed a new multiaxial yield theory for isotropic hardening materials, based on an average shear stress criterion (ASSC). Extensive classic experiments showed that the ASSC criterion can well correlate the stress-strain relations for both initial yield and subsequent yield states. Based on the ASSC yield theory, a new theoretical solution of the burst pressure of pipelines at plastic collapse is developed as a function of pipe geometry, material hardening exponent, and ultimate tensile strength. This solution is then validated by experimental data for various pipeline steels. The ASSC yield theory is further applied to accurately determine actual burst pressure using available finite element software like ABAQUS, which currently adopts the von Mises yield criterion and the associate flow rule for isotropic elastic-plastic analysis. Four burst failure criteria: the Mises equivalent stress criterion, the maximum principal stress criterion, the Mises equivalent strain criterion and the maximum tensile strain criterion are developed as functions of the ultimate tensile stress and the strain hardening exponent. Application demonstrates that the proposed failure criteria in conjunction with ABAQUS numerical analysis can accurately determine burst pressure of pipelines.Copyright © 2006 by ASME
Strategies actually employed during response-focused emotion regulation research: Affective and physiological consequences

Addressing internal validity concerns in emotion regulation research, the present experiment was primarily designed to determine whether research participants are compliant when asked to use a response-focused strategy during emotional film viewing or whether these individuals incorporate the use of antecedent strategies. The influence of antecedent vs. response-focused strategy use on self-reported affect, physiological, and behavioural data were additionally investigated. A total of 82 healthy undergraduate participants were asked to use one of two response-focused emotion regulation techniques—suppression or exaggeration—while watching a 2 minute positive or negative movie. Following the movie, participants self-reported their affective response to the film, described how they tried to suppress or exaggerate their reaction (i.e., strategies used to regulate their response), and estimated the percentage of time they used each strategy. Representing “antecedent” and “response-focused” techniques, the str...
Diameter distribution of thermally evaporated indium metal islands on silicon substrates

Although many groups have studied the initial growth stages of various metals, including indium, there is little information in literature on diameter distributions of indium in relation to film thickness or annealing conditions. This paper reports island size distributions of thermally evaporated In islands on Si (100) and Si (111) substrates for nominal film thicknesses ranging from 5 to 50 nm. Because indium has a low melting temperature, and therefore a high homologous temperature at room temperature, 3-dimensional islands form during deposition with no subsequent heat treatments needed. Island diameters were calculated using commercial image analysis software in conjunction with SEM images of the samples. It is found that there is a bimodal island diameter distribution for nominal indium thicknesses greater than 5 nm. While the diameters of the larger islands increase exponentially with nominal thickness, those of the smaller islands increase linearly, and therefore more slowly, with nominal thickness. For nominal thickness of 50 nm, the average diameters of the small and large islands differ by almost an order of magnitude. Anneal conditions were studied in an attempt to narrow diameter distributions. Samples of each nominal thickness were annealed at temperatures ranging from 360°C to 550°C and the diameters again measured. The range of island diameters become narrower with 360°C anneal and volume average island diameter increases by ~30-50%. This narrowing of the distribution occurs due to smaller islands being absorbed by the larger in a process akin to Ostwald ripening, which is facilitated by higher surface diffusivities at higher homologous temperatures.
CONNECTION BETWEEN REGGE POLES AND ELEMENTARY PARTICLE POLES

It is shown that if in a field theory the proper vertex function $\ensuremath{\Gamma}(s)$ vanishes under a condition that the proper vertex-function poles are not the poles of scattering amplitudes, then the elementary particle lies smoothly on the Regge trajectory. [The condition $\ensuremath{\Gamma}(s)\ensuremath{\equiv}0$ does not always mean the vanishing of the coupling constant, when the vertex function poles exist.] The bootstrap equations are immediate consequences of the above condition. We formulate our problem using multichannel theory. Other related results are: (a) It is found that in the multichannel case as well as in the single-channel case, the proper vertex poles are not the poles of scattering amplitudes if the poles come up from the second Riemann sheet. (b) The finite self-mass condition of the composite particle, due to Gerstein and Deshpande, is not applicable when the proper vertex pole appears below the elementary-particle mass, i.e., the modified propagator needs one substraction. (c) Vanishing renormalization constants, ${Z}_{1}={Z}_{3}=0$, are not sufficient to Reggeize the elementary particle. (d) All our conclusions remain true even when additional bound-state poles are included. In the latter case, however, we can also use a different condition, due to Kaus and Zachariasen, that the form factor (improper vertex function) and ${Z}_{3}$ both vanish; then our main results again follow, that the elementary particle lies on the Regge trajectory and that the bootstrap equations are obtained. (The vanishing form factor does not always mean the vanishing of the coupling constant, when the bound-state poles exist.) But this last condition implies that the unsubtracted dispersion relations in weak interactions are not valid.
Investigating agricultural sustainability and strategies in northern Mesopotamia : results produced using a socio-ecological modeling approach

Some of the most politically and culturally significant cities in first millennium BC northern Mesopotamia were located in agriculturally marginal landscapes. In order to sustain these settlements, variant cultivation techniques were practiced by local populations. Understanding the dynamics and implications of crop management practices requires that socio-ecological variables be addressed over recurrent crop cycles. This paper employs a coupled socio-ecological modeling approach that enables interactions between a quantitative environmental model and an agent-based social model by using the ENKIMDU simulation tool. The reconstructed landscape near the ancient city of Assur is used as the example setting to test the effectiveness of simulated cultivation strategies. These methods include sole dependence on biennial fallow and rainfall, gravity flow irrigation, application of manure, and the integration of all these approaches. Results obtained within ENKIMDU attempt to delineate agricultural constraints and potential benefits of the specific anthropogenic processes and strategies addressed.
Ammonia-Water Complexes on the Surface of Aqueous Solutions Observed with Sum Frequency Generation

Sum frequency generation (SFG) is used to obtain the vibrational spectrum of aqueous ammonia solution. The SF spectrum of concentrated solutions is dominated by the N–H symmetric stretch (ν1) at 3312 cm−1 and a weaker deformation mode (2ν4) at 3200 cm−1. The free OH peak of water is suppressed, compared to pure water, and the hydrogen-bonded region (3000–3450 cm−1) has interference in the presence of ammonia molecules at the interface. In dilute solution, ν1 is less intense and the free OH peak of water appears. These observations confirm the existence of an ammonia–water complex at the liquid/vapor interface.
Lights, Camera, Action! Video Consent—Take Two!

To meet the needs of the 21st century, radiology nursing will rise to new levels. With the growth of technology, new creative strategies need to be developed to enhance physician/patient communication. In our Pediatric Radiology Department, we have instituted an innovative concept of video consenting for procedural sedations. Legality issues were investigated by our department radiologist through the Procedural Sedation Board and legal services. A survey was instituted. The purpose of our survey is to analyze parental satisfaction in using video vs. personal physician consent. Completed surveys have indicated that video consents have improved the quality of service for our pediatric patients and families.
Effects of divalent cations on the ultrasonic absorption coefficient of negatively charged liposomes (LUV) near their phase transition temperature

Abstract The ultrasonic absorption coefficient per wavelength (αλ), as a function of temperature and frequency, was determined for large unilamellar vesicles (LUV) in the vicinity of their phospholipid phase transition temperature, using a double crystal acoustic interferometer. (The vesicles were composed of a 4:1 (w/w) mixture of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG)). It has been found that αλ reaches a maximum ( αλ ) max at the phase transition temperature ( t m ) of the phospholipids in the bilayer, at an ultrasonic relaxation frequency of 2.1 MHz. Divalent cations (Ca 2+ and Mg 2+ ), added to LUV suspensions, shifted ( αλ ) max to higher temperatures, dependent upon the concentration of divalent cation. It was also found that the shape of the αλ versus t curve was significantly changed, representing changes in the Van't Hoff enthalpy of the transition, and therefore, the cooperative unit of the transition. This suggests that divalent cations interact individually with the negatively charged phospholipid headgroups of DPPG and with DPPC headgroups, thus decreasing the cooperative unit of the transition. The observed upward shift in t m suggests an interaction that increases the activation energy and, therefore, the temperature of the phase transition. However, αλ as a function of frequency did not change with the addition of divalent cations and, thus, the relaxation time of the event responsible for the absorption of ultrasound is not changed by the addition of divalent cations.
Inhalation toxicology: Starting with the environment

The theme of SETAC's Second Annual Meeting was Environmental Risk Assessment, with emphasis on the use of data in the risk assessment and overall decision making process for chemicals. Needs for specific types of data were emphasized by the theme of the meeting and in no area was the void more obvious than in inhalation toxicology. Sufficient information for decision making in this area simply is not available, and no better combination of expertise exists for making judgments of risk than that of the environmental and mammalian toxicologists. To foster further communication between the two, a symposium was held in which experienced mammalian-oriented toxicologists were asked to address the state-of-the-art of inhalation toxicology for the benefit of those more oriented toward the traditional environmental toxicology area. Papers for the symposium are published herein to encourage continued efforts by all toxicologists to share in the data development and decision making process essential for healthy humans to enjoy a quality environment. The present paper is introductory in nature but utilizes recent findings in the author's laboratory concerning inhalation exposure and retention of chemical vapors in rats to demonstrate the rationale for selecting other topics for presentation.
A critical review of the Energy Policy Act of 2005's treatment of hydrogen

The paper analyzes the Energy Policy Act's goals and proposed action in Title VIII, the section dedicated to hydrogen. It then assesses whether or not the resources dedicated to this cause are sufficient to overcome the obstacles facing the commercial use of hydrogen and fuel cells.
Matrix isolation and theoretical study of the reaction of substituted phosphines with CrCl2O2.

The reactions between CrO2Cl2 and a series of substituted phosphines have been investigated using matrix isolation infrared spectroscopy. For all of the phosphines except PF3, twin jet co-deposition of the two reagents into argon matrices at 14 K initially led to the formation of weak bands due to the corresponding phosphine oxide. For all of the phosphines, subsequent irradiation with light of λ > 300 nm led to the growth of a number of intense new bands that have been assigned to the phosphine oxide complexed to CrCl2O, following an oxygen atom transfer reaction. Gas-phase, merged jet reactions prior to matrix deposition led to a significant yield of the uncomplexed phosphine oxide. Theoretical calculations at the B3LYP/6-311++g(d,2p) level were carried out in support of the experimental work, to support product band assignments and clarify the nature of the molecular complexes.
Orthotopic Cardiac Transplantation for Univentricular Heart

The technical aspects of orthotopic cardiac transplantation for univentricular heart in a 22-year-old man are discussed. Abnormal pulmonary artery anatomy resulted in right ventricular failure, which was successfully treated.
Model simulations of the Gulf of Maine response to storm forcing

[1] The storm response of the Gulf of Maine/Georges Bank region was investigated using the Dartmouth three-dimensional, nonlinear, finite element coastal ocean circulation model called QUODDY, with uniform density and quadratic bottom stress. A suite of model hindcast experiments were conducted for the 4–8 February 1987 period that featured a strong nor'easter. The model was forced at the open ocean boundaries by the M2 semidiurnal tidal sea level and in the interior by realistic surface wind stresses and, in some cases, atmospheric pressure. The reference model run, with just tidal and wind stress forcing and a time-space constant bottom drag coefficient Cd of 0.005, captured 65% of the observed detided, low-pass filtered or “subtidal” sea level variance of a representative array of coastal and bottom pressure stations in the Gulf. However, there remained large unexplained model/observed sea level differences, particularly during the storm. Model sensitivity testing to a realistic range of constant Cd values did not improve model results significantly. However, results of a model run in which atmospheric pressure forcing, derived through linear interpolations of regional measurements, was added to wind stress forcing captured 82% of the observed subtidal sea level variance.
Determination of the Oxygen Deficiency in Vacuum‐Hot‐Pressed Ferroelectric Ceramics Using a Thermogravimetric Technique

An attempt to measure the oxygen deficiency in vacuum-hot-pressed ferroelectric target materials was made, using a thermogravimetric method. The approach was intended to measure the relative mass increase of oxygen-deficient sheet samples, with respect to an oxidized reference that was annealed in air. A saturation of mass change was achieved, which indicated a saturated oxidation state and provided a basis for further calculation of the oxygen deficiency in the samples. Results were obtained for barium strontium titanate and lead lanthanum zirconate titanate compositions, which shows the feasibility of applying the thermogravimetric method to ferroelectric materials.
Studies of the adsorption of acetaldehyde, methyl acetate, ethyl acetate, and methyl trifluoroacetate on silica

Abstract Microcalorimetric, infrared spectroscopic, and temperature-programmed-desorption studies are combined with quantum-chemical calculations based on density-functional theory (DFT) to study the adsorption of acetaldehyde, methyl acetate, ethyl acetate, and methyl trifluoroacetate on amorphous silica. Adsorption of these molecules on silica proceeds primarily through formation of two hydrogen bonds per adsorbate, involving the donation of electron density from the lone-pair orbital on the carbonyl oxygen to hydrogen atoms in surface hydroxyl groups. The formation of these hydrogen bonds causes shifts to lower wavenumbers of infrared bands associated with the stretching of CO and O–H bonds. On the basis of microcalorimetric and thermal-desorption measurements, hydrogen bonds are estimated to have an average energy of 34±4 kJ/mol for methyl or ethyl acetate adsorption, and an energy of 27±4 kJ/mol per bond for the adsorption of acetaldehyde or methyl trifluoroacetate. The initial heats of adsorption of methyl acetate, ethyl acetate, and methyl trifluoroacetate are 95, 96, and 92 (±5) kJ/mol, respectively. These high heats of adsorption at low coverages are assigned, based on DFT calculations and spectroscopic measurements, to the formation of more than two hydrogen bonds with the oxide surface, thereby involving the alkoxy oxygen of the esters. The high initial heat of acetaldehyde adsorption (86 kJ/mol) may be caused by oligomerization processes.
Galen and the Ontology of Powers

What, for Galen, are powers, and how are they to be properly individuated? The notion of a power or capacity (dunamis) does a great deal of work in Galen. As in Aristotle, the concept of a dunamis is tightly linked with that of an energeia, but these are not simply logical abstractions. Rather the natural energeiai are the basic functional activities of the animal body and its parts, and just as health consists in proper functioning, so disease is defined as ‘damage to one of the natural energeiai of the body’, and these activities are damaged when something interferes with its related dunamis. Here I try to make sense of the apparently very different things Galen says regarding dunameis. For example, he says that they do not inhabit our bodies as we do our houses; that is, presumably, they are not substantial or hypostasized; rather they are properties of us. Equally, he is perfectly clear that they are relational items: a power is a power for affecting something determinate in some determinate way. They...
Behavioral characterization and Particle Filter localization to improve temporal resolution and accuracy while tracking acoustically tagged fishes

Abstract Quantifying the fine-scale movement patterns and habitat use of active fishes has historically been challenging due to their scope of movement or the labor intensive nature of actively tracking potentially wide-ranging species. This project focuses on improving the localization accuracy and temporal resolution of an acoustically tagged fish by filtering the position measurements received from an acoustic receiver array. Using the k-means clustering algorithm, data sets are broken into groups which have similar fish speeds and yaw rates to yield a discrete number of movement behaviors characterized by the mean and standard deviation of speed and yaw. Next, a Particle Filter state estimator is proposed, in which position and speed state estimates of particles are used to calculate the most likely motion behavior, which in turn is used as a first order motion model to propagate the particle's fish state estimates forward in time. These predicted particle states are compared with the position measurements and then resampled as done with most Particle Filters. Offline processing of a shovelnose guitarfish (Rhinobatos productus) data set shows that the estimation of the fish's location is improved during periods of time when no measurements could be obtained when compared with two common filtering approaches.
A new dynamic beta-ratio circuit technique for strained-Si technology

In this paper, a new dynamic /spl beta/-ratio technique for strained Si technology where the strength of the pFET is enhanced during active operation. The viability and benefit of the technique are discussed and compared with alternative techniques.
Effect of size, shape, composition, and support film on localized surface plasmon resonance frequency: A single particle approach applied to silver bipyramids and gold and silver nanocubes

Localized surface plasmon resonances (LSPR), collective electron oscillations in nanoparticles, are being heavily scrutinized for applications in chemical and biological sensing, as well as in prototype nanophotonic devices. This phenomenon exhibits an acute dependence on the particle’s size, shape, composition, and environment. The detailed characterization of the structure-function relationship of nanoparticles is obscured by ensemble averaging. Consequently, single-particle data must be obtained to extract useful information from polydisperse reaction mixtures. Recently, a correlated high resolution transmission electron microscopy (HRTEM) LSPR technique has been developed and applied to silver nanocubes. We report here a second generation of experiments using this correlation technique, in which statistical analysis is performed on a large number of single particles. The LSPR dependence on size, shape, material, and environment was probed using silver right bipyramids, silver cubes, and gold cubes. It was found that the slope of the dependence of LSPR peak on size for silver bipyramids increases as the edges become sharper. Also, a plasmon shift of 96 nm was observed between similar silver and gold cubes, while a shift of 26 nm was observed, for gold cubes, between substrates of refractive index (RI) of 1.5 and 2.05.
Health monitoring during vibratory compaction of soil

Vibratory compaction is a proven and commonly adopted densification technique applicable for a wide variety of soil types and compositions. There is a clear need to develop performance-based intelligent vibratory soil compaction techniques wherein the state of the soil is determined during compaction (i.e., health monitoring, continuous quality control). The application of vibration-based structural health monitoring strategies utilized in damage detection applications to the problem of soil compaction appears promising. A vibratory compactor (plate or drum) operating on a soil mass constitutes a coupled dynamic system. As the soil densifies and its mechanical properties change, the dynamic response of the compactor will change. This paper examines the changes in dynamic response of a vibratory plate during compaction. The analysis of vibration data taken from sensors on the plate and embedded within the soil reveals clear changes in both amplitude and frequency components that provide insight into the evolving nonlinear response of the system.
Lattice spectrum and dielectric properties of EuF2

Abstract Measurements at room temperature of the infrared reflectivity, low frequency dielectric constant (ϵg = 7.7 ± 0.2) and optical index of refraction (n = 1.555 ± 0.005) have been carried out on EuF2. The data have been analyzed both by classical dispersion theory and Kramers-Kronig relations to obtain the frequency dependent dielectric dispersion from 50 cm−1 to 1400 cm−1. As has been found for other crystals of the fluorite type, a single strong resonant absorption is found. The optical mode frequencies are ωt0 = 194 cm−1; ωl0 = 347 cm−1. The best classical dispersion formula fit to the reflectivity yields the following parameters: ω0 = 195.2 cm−1, 4πρ = 5.15, \ gg = 25.2 cm−1. The (Szigeti) effective charge on the Eu+2 ion is 1.67 e. These results are used to discuss polarizabilities, covalency, and crystal chemistry of divalent europium compounds within the context of a ‘shell’ model.
Erythropoietin production rate in phlebotomy-induced acute anemia.

Objective. To estimate the rate of erythropoietin (EPO) production under physiological, conditions and to examine the regulatory mechanism of EPO production in response to acute phlebotomy-induced anemia. Methods. Six sheep each underwent two phlebotomies in which the hemoglobin (Hb) was reduced to 3–4 g/dl over 4–5 h. The EPO plasma level, reticulocytes, Hb and EPO clearance were followed by frequent blood sampling. The EPO production rate was determined by a semi-parametric method based on a disposition decomposition analysis that accounts for the nonlinear disposition kinetics of EPO and corrects for time-dependent changes in the clearance. Results. The controlled drop in hemoglobin resulted in an abrupt increase in the plasma EPO concentration (peak level 812 ± 40 mU/ml, mean ± CV%) that was followed by a rapid drop 2–4 days after the phlebotomy at a time when the sheep were still anemic (Hb = 4.3 ± 16 g/dl). The EPO production rate at baseline was 43 ± 52 U/day/kg and the amounts of EPO produced over an 8 day period resulting from the first and second phlebotomy were 2927 ± 40 U/kg and 3012 ± 31 U/kg, respectively. Conclusions. The rapid reduction in the EPO plasma level observed 2–4 days following the phlebotomy cannot be explained solely by the increase in EPO clearance but also by a reduction in EPO production. Copyright © 2004 John Wiley & Sons, Ltd.
Linear programming design of multivariable feedback controllers for the NERVA nuclear engine

The application of Linear Programming (LP) to the design of state variable feedback controllers for multivariable plants with known deterministic inputs is described. The design problem is solved in two steps. The first step consists of an open-loop optimization in which LP is used to determine the plant input vector profile which optimizes the plant response to a specified demand. The second step, also implemented by LP, produces the controller parameters (a matrix of constant gains) and consists of an optimum fitting, through the feedback controller, of the input and feedback error vector profiles determined in the first step. The performance criterion used is the minimum Integral Weighted Absolute Value (IWAV). The technique is illustrated with an application to the NERVA nuclear rocket engine controller design.
RAPID DETECTION OF SALMONELLA TYPHIMURIUM USING AN IMMUNOELECTROCHEMICAL METHOD COUPLED WITH IMMUNOMAGNETIC SEPARATION

An immunoelectrochemical method coupled with magnetic separation was developed for rapid detection of Salmonella typhimurium. Samples containing Salmonella were mixed with anti-Salmonella coated magnetic beads (ASCMB) and alkaline phosphatase labeled anti-Salmonella (APLAS) simultaneously to form ASCMB-Sdhaoaella-APLAS conjugates by antibody-antigen reaction. The conjugates were separated by a magnetic field and were incubated with phenyl phosphate substrate to produce phenol. The number of Salmonella was determined by measuring the phenol concentration using an amperometric tyrosinase biosensor. This method could be completed within two hours with a detection limit of 5 times 103 cells/mL under optimized conditions (with ***1 mM MgCl2, 0.2 μg/mL APLAS and ***l mM phenyl phosphate in pH 7.0 TBS). A linear response on semi-log scale was found for Salmonella pure culture between 5 times 103 and 1 times 106 cells/mL.
Ultrasensitive microfluidic solid-phase ELISA using an actuatable microwell-patterned PDMS chip

Quantitative detection of low abundance proteins is of significant interest for biological and clinical applications. Here we report an integrated microfluidic solid-phase ELISA platform for rapid and ultrasensitive detection of proteins with a wide dynamic range. Compared to the existing microfluidic devices that perform affinity capture and enzyme-based optical detection in a constant channel volume, the key novelty of our design is two-fold. First, our system integrates a microwell-patterned assay chamber that can be pneumatically actuated to significantly reduce the volume of chemifluorescent reaction, markedly improving the sensitivity and speed of ELISA. Second, monolithic integration of on-chip pumps and the actuatable assay chamber allow programmable fluid delivery and effective mixing for rapid and sensitive immunoassays. Ultrasensitive microfluidic ELISA was demonstrated for insulin-like growth factor 1 receptor (IGF-1R) across at least five orders of magnitude with an extremely low detection limit of 21.8 aM. The microwell-based solid-phase ELISA strategy provides an expandable platform for developing the next-generation microfluidic immunoassay systems that integrate and automate digital and analog measurements to further improve the sensitivity, dynamic ranges, and reproducibility of proteomic analysis.
Determining Intrinsic Healing Properties of Asphalt Binders: Role of Dynamic Shear Rheometer

A self-healing material has the inherent ability to partially reverse damage. There is consensus that the healing of damage has a substantial effect on the performance of asphalt pavements. It is important to understand the mechanisms responsible for healing in asphalt binders, to develop a model to predict healing on the basis of these mechanisms, and to develop test methods to determine the properties required for use with such a model. A healing model for asphalt materials comprises a convolution of wetting and intrinsic healing processes that occur across a crack interface. According to the proposed convolution process, intrinsic healing or strength gain across a crack surface occurs in two steps: an instantaneous strength gain resulting from the interfacial cohesion between the crack faces, and a time-dependent strength gain resulting from intermolecular diffusion and randomization across the crack interface. A modified form of the Avrami equation, which includes a parameter for instantaneous strength gain, is used to describe the intrinsic healing in asphalt binders. A test method is described that is based on the use of a dynamic shear rheometer for estimating the parameters of the intrinsic healing function. Five asphalt binders with considerably different compositions were studied. Limited validation of this test method and the intrinsic healing model are presented by comparing the parameter related to instantaneous healing with the thermodynamic work of cohesion for the selected binders.
Synthesis and elastic and mechanical properties of Cr2GeC

Herein we report on the synthesis and characterization of Cr2GeC, a member of the so-called Mn+1AXn (MAX) phase family of layered machinable carbides and nitrides. Polycrystalline samples were synthesized by hot pressing pure Cr, Ge, and C powders at 1350 °C at ∼45 MPa for 6 h. No peaks other than those associated with Cr2GeC and Cr2O3, in the form of eskolaite, were observed in the x-ray diffraction spectra. The samples were readily machinable and fully dense. The steady-state Vickers hardness was 2.5 ± 0.1 GPa. The Young’s moduli measured in compression and by ultrasound were 200 ± 10 and 245 ± 3 GPa, respectively; the shear modulus and Poisson’s ratio deduced from the ultrasound results were 80 GPa and 0.29, respectively. The ultimate compressive strength for a ∼20 μm grain size sample was 770 ± 30 MPa. Samples compressively loaded from 300 to ∼570 MPa exhibited nonlinear, fully reversible, reproducible, closed hysteretic loops that dissipated ∼20% of the mechanical energy, a characteristic of the MAX phases, in particular, and kinking nonlinear elastic solids, in general. The energy dissipated is presumably due to the formation and annihilation of incipient kink bands. The critical resolved shear stress of the basal plane dislocations—estimated from our microscale model—is ∼22 MPa. The incipient kink band and reversible dislocation densities, at the maximum stress of 568 MPa, are estimated to be 1.2 × 10−2 μm−3 and 1.0 × 1010 cm−2, respectively.
Comparison of RefSeq protein-coding regions in human and vertebrate genomes

Advances in high-throughput sequencing technology have yielded a large number of publicly available vertebrate genomes, many of which are selected for inclusion in NCBI’s RefSeq project and subsequently processed by NCBI’s eukaryotic annotation pipeline. Genome annotation results are affected by differences in available support evidence and may be impacted by annotation pipeline software changes over time. The RefSeq project has not previously assessed annotation trends across organisms or over time. To address this deficiency, we have developed a comparative protocol which integrates analysis of annotated protein-coding regions across a data set of vertebrate orthologs in genomic sequence coordinates, protein sequences, and protein features. We assessed an ortholog dataset that includes 34 annotated vertebrate RefSeq genomes including human. We confirm that RefSeq protein-coding gene annotations in mammals exhibit considerable similarity. Over 50% of the orthologous protein-coding genes in 20 organisms are supported at the level of splicing conservation with at least three selected reference genomes. Approximately 7,500 ortholog sets include at least half of the analyzed organisms, show highly similar sequence and conserved splicing, and may serve as a minimal set of mammalian “core proteins” for initial assessment of new mammalian genomes. Additionally, 80% of the proteins analyzed pass a suite of tests to detect proteins that lack splicing conservation and have unusual sequence or domain annotation. We use these tests to define an annotation quality metric that is based directly on the annotated proteins thus operates independently of other quality metrics such as availability of transcripts or assembly quality measures. Results are available on the RefSeq FTP site [ http://ftp.ncbi.nlm.nih.gov/refseq/supplemental/ProtCore/SM1.txt ]. Our multi-factored analysis demonstrates a high level of consistency in RefSeq protein representation among vertebrates. We find that the majority of the RefSeq vertebrate proteins for which we have calculated orthology are good as measured by these metrics. The process flow described provides specific information on the scope and degree of conservation for the analyzed protein sequences and annotations and will be used to enrich the quality of RefSeq records by identifying targets for further improvement in the computational annotation pipeline, and by flagging specific genes for manual curation.