cssi/SciSciGPT-SciSciNet huggingface dataset:
Using optical reflectance to measure GaN nucleation layer decomposition kinetics

Abstract GaN nucleation layers (NLs) that are used in the two-step GaN growth process on sapphire partially decompose during the ramp from low to high temperature, T . In this paper, we show how the extent of this decomposition can be measured during each growth run using optical reflectance. Using reflectance, the NL decomposition rates were observed to increase with increasing P and T , and decreasing NH 3 flow. Also, the NL decomposition rate did not change as the NL growth T was varied, but did increase as the NL thickness increased. The NL decomposition has an activation energy, E A , of 2.7 ± 0.2 eV for all annealing conditions studied, while the pre-exponential factor, A 0 , depends strongly on the annealing conditions and initial NL thickness. Using the measured NL decomposition kinetics, an analytical model is used to fit the reflectance waveforms which also includes the T dependence of indices of refraction. The model was applied to several sets of reflectance waveforms where the annealing conditions were intentionally varied and the values of A 0 measured and compared. In addition to directly fitting the reflectance waveforms, we introduce another way to quantify decomposition rates measured under constant or varying T . This approach requires a constant E A for the reaction kinetics throughout the entire T range of interest, which is the case for the GaN NL decomposition. For this approach, time is scaled by an integrated form of the Arrhenius exponential (i.e. exp ( - E A / k B T ) ). We have called this transformation of the time scale the “kinetic advancement,” because it allows kinetic processes at constant or varying T to be compared directly. If the reflectance waveform or NL thickness is plotted vs. the kinetic advancement, a straight line results with the slope equal to A 0 . The usefulness of both reflectance waveform fitting procedures is discussed, specifically how the reflectance waveform can be compared and quantified during every growth run in order to verify NL evolution repeatability.
π-α scattering and the pionic form factor

Theoretical calculations are carried out on π--α. and π+-α elastic scattering processes. Results are presented at a typical incident pion energy of 100 MeV. The results are sensitive to the pion’s electromagnetic form factor since the form factor of the a-particle may be taken from electron scattering experiments. If the pion size is large the burden on the theoretical calculations is not great. However if the pion size is small the calculations must be refined. In any case the comparison ofK a andn a scattering is quite worth while and suggestions are made on how to carry it out.
Phototherapeutic keratectomy versus diamond burr polishing of Bowman's membrane in the treatment of recurrent corneal erosions associated with anterior basement membrane dystrophy.

Abstract Purpose To compare the efficacy of phototherapeutic keratectomy (PTK) to epithelial debridement and polishing of Bowman's membrane using a diamond burr (DB) in the treatment of recurrent corneal erosions associated with anterior basement membrane (ABM) dystrophy. Design Retrospective nonrandomized comparative trial. Methods Medical records of 39 patients (42 eyes) who underwent a PTK or DB procedure for recurrent corneal erosions associated with ABM dystrophy between March 1992 and June 2000 were reviewed. History of injury, prior treatment received, and the corneal slit-lamp findings were noted in all patients. In both procedures, all loose epithelium was completely removed. In PTK patients, 5 μm of Bowman's membrane was ablated with the excimer laser. In patients who underwent DB treatment, a hand-held battery-driven diamond dusted burr was used to gently and uniformly polish Bowman's membrane in the area of the epithelial defect. Main outcome measures Symptomatic improvement, recurrence of painful erosions, development of haze, and change in the visual acuity. Statistical analysis was performed for comparison of data between the two groups. Results Fifteen eyes of 14 patients underwent PTK, and 27 eyes of 25 patients underwent epithelial debridement and DB treatment. In the PTK group, mild haze was seen in five (35.7%) eyes. Recurrence of painful erosions was seen in four eyes (26.7%). The mean follow-up was 17.6 ± 5.7 months (range, 0.7–81.9 months). Best-corrected visual acuity was better in five eyes (35.7%) after the procedure and the same in nine eyes (64.3%). In the DB group, mild haze was seen in seven eyes (25.9%). Recurrence of painful erosions was seen in three eyes (11.1%). The mean duration of follow-up was 6.7 months (range, 1–24.2 months). Best-corrected visual acuity was better in 3 eyes (14.3%), the same in 17 eyes (81%), and worse in 1 eye (4.8%) after the procedure. Final visual acuity was not available for one eye in the PTK group and 6 eyes in the DB group. There was no statistically significant difference in haze (Fisher's exact test, P = 0.38), recurrence of erosions (Kaplan-Meier analysis with log rank, P = 0.73), and vision being better or the same (Fisher's exact test, P = 0.6) between the PTK and DB groups. Conclusions Both PTK and DB treatment are effective methods of treating recurrent corneal erosions associated with ABM dystrophy. Diamond burr treatment, being a simpler, less expensive office procedure with a tendency toward lesser incidence of haze and recurrence in this study, seems to have advantages over PTK in the treatment of recurrent corneal erosions. Further prospective studies are required to confirm the long-term efficacy of DB treatment in the management of recurrent corneal erosions associated with ABM dystrophy.
Inhibition of macromolecular synthesis in L1210 mouse leukemia ascites cells by hycanthone

Hycanthone inhibits macromolecular synthesis in L1210 cells. At the same concentrations of hycanthone, DNA synthesis is inhibited to a greater extent than the synthesis of RNA. There is an inhibition by the drug of the synthesis of ribosomal precursor RNA; the synthesis of other types of RNA including heterogeneous and small-molecular-weight, also appears to be inhibited. Maturation of 45-S RNA does not seem to be affected, and there is a partial reversal of inhibition of both DNA and RNA synthesis by washing the cells free of hycanthone.
Christoffel functions and Fourier series for multivariate orthogonal polynomials

Abstract The Christoffel functions Λ n ( d μ) associated with a general nonnegative measure μ on R d are studied. The asymptotics of Λ n ( d μ) are derived for μ supported on [− 1,1] d . The estimates of Λ n ( d μ) are used to study the summability of the multivariate orthogonal polynomials associated with μ. The pointwise convergence of the partial sums of the orthogonal expansion, and their ( C , 1) and de la Vallee Poussin means are considered.
Coincidence avoidance principle in surface haptic interpretation

When multiple fingertips experience force sensations, how does the brain interpret the combined sensation? In particular, under what conditions are the sensations perceived as separate or, alternatively, as an integrated whole? In this work, we used a custom force-feedback device to display force signals to two fingertips (index finger and thumb) as they traveled along collinear paths. Each finger experienced a pattern of forces that, taken individually, produced illusory virtual bumps, and subjects reported whether they felt zero, one, or two bumps. We varied the spatial separation between these bump-like force-feedback regions, from being much greater than the finger span to nearly exactly the finger span. When the bump spacing was the same as the finger span, subjects tended to report only one bump. We found that the results are consistent with a quantitative model of perception in which the brain selects a structural interpretation of force signals that relies on minimizing coincidence stemming from accidental alignments between fingertips and inferred surface structures.
Statistically weighted non-local method of iterative digital image processing

A direct non-local iterative deconvolution method (NLM) employing the algorithm has been developed and successfully applied to tomographic radioisotopic tissue concentration imaging: PSRF are the point source response functions of the measurement system, (x,y,z) are the coordinates of the tissue element, and D(X,Y,Z) are the data elements corresponding to the measurement system indexing coordinates (X,Y,Z). High resolution determination of radioisotopic tissue concentrations on a scale aproximating the pixel spacing are routinely achieved even with relatively broad PSRF's and even though the individual data elements necessarily reflect a significant degree of radioisotopic statistical fluctuation. NLM converges to the correct high resolution source distributions with ideal and/or randomized data over a much wider range of conditions than the Gauss-Seidel method of iterative deconvolution. Comparative results will be presented.© (1984) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
SAR distributions for 915 MHz interstitial microwave antennas used in hyperthermia for cancer therapy

Theoretical and experimental specific absorption rate (SAR) distributions are presented for single insulated antennas operating at 915 MHz in muscle phantom; the SAR is deduced from measured temperature rise. Results show that dipoles with lengths much shorter than their resonant length have a characteristically large reactive input impedance component and a substantially smaller absolute SAR magnitude than resonant dipoles. All cases investigated demonstrate that the maximum SAR occurs near the junction, regardless of insertion depth. Experimental results show that an antenna with the tip section equal to a quarter-wavelength and the insertion depth equal to a half-wavelength achieves a substantial increase in the longitudinal power distribution compared to other antenna designs that were evaluated. >
Effect of feedback contingencies on the control of occipital alpha.

Ten color transparencies were presented 30 times each to ten normal adults in response to changes in their occipital-parietal EEG's. By means of a feedback paradigm, detected alphas caused each slide to flash and stay on as long as alpha persisted, and then to turn off when alpha attenuated, according to four different contingency conditions. For half of the feedback trials, stimulus presentation depended on alpha detection in only one hemisphere and was not influenced by changes in the simultaneously recorded contralateral EEG. For the other feedback trials, stimulus presentation was bilaterally contingent. These contingency configurations were compared with sham feedback, a noncontingent condition during which slide presentation was controlled by a prerecorded tape. For both alpha and no-alpha, the ratio of mean duration over standard error\(({{\bar X} \mathord{\left/ {\vphantom {{\bar X} {SE}}} \right. \kern-\nulldelimiterspace} {SE}})\) was used as a quantification of the EEG response to visual stimulation. It was assumed that larger ratios indicated increased control of the EEG. Compared with the sham condition, all feedback contingencies produced greater\({{\bar X} \mathord{\left/ {\vphantom {{\bar X} {SE}}} \right. \kern-\nulldelimiterspace} {SE}}\) ratios, and hence, improved control of the EEG. The highest ratios were obtained during unilateral feedback from the EEG in which the occurrence of alpha elicited the visual stimulus. The results show that contingency between a visual stimulus and the EEG is an important parameter with regard to experimental control of the EEG.
Surface Analytical Observations During Construction and Initial Operation of TCSU

To minimize radiation-loss effects, preparation and in-situ conditioning of plasma-facing surfaces in the Translation Confinement and Sustainment Upgrade experiment (TSCU) was carried out with utmost attention. To assess the condition of the TCSU first walls during the construction and operation, chemical and morphological surface analysis techniques such as X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) were utilized. Here we present a summary of the preliminary and ongoing work performed for TCSU wall-conditioning, including preparation of UHV compatible surfaces, glow discharge cleaning (GDC), and siliconization. Effective techniques were developed for cleaning various plasma-facing components, including Al flux rings, stainless steel chambers and components, and quartz surfaces, prior to their installation. Helium-GDC was tested and proved to be useful in reducing the plasma impurities; however, extended periods of GDC resulted in the coating of quartz surfaces due to the sputtering of neighboring stainless steel walls by energetic glow particles. In addition, as a wall conditioning technique, siliconization has been examined in a separate system dedicated for detailed analysis of the process.
Ducks: the "Trojan horses" of H5N1 influenza.

Abstract Wild ducks are the main reservoir of influenza A viruses that can be transmitted to domestic poultry and mammals, including humans. Of the 16 hemagglutinin (HA) subtypes of influenza A viruses, only the H5 and H7 subtypes cause highly pathogenic (HP) influenza in the natural hosts. Several duck species are naturally resistant to HP Asian H5N1 influenza viruses. These duck species can shed and spread virus from both the respiratory and intestinal tracts while showing few or no disease signs. While the HP Asian H5N1 viruses are 100% lethal for chickens and other gallinaceous poultry, the absence of disease signs in some duck species has led to the concept that ducks are the “Trojan horses” of H5N1 in their surreptitious spread of virus. An important unresolved issue is whether the HP H5N1 viruses are maintained in the wild duck population of the world. Here, we review the ecology and pathobiology of ducks infected with influenza A viruses and ducks’ role in the maintenance and spread of HP H5N1 viruses. We also identify the key questions about the role of ducks that must be resolved in order to understand the emergence and control of pandemic influenza. It is generally accepted that wild duck species can spread HP H5N1 viruses, but there is insufficient evidence to show that ducks maintain these viruses and transfer them from one generation to the next.
Effect of platelet activating factor on leukocyte-endothelial cell interactions

The proinflammatory effects of platelet activating factor (PAF) that impact upon tissue inflammation were studied in vitro using the adherence of human neutrophils to endothelium and the increase in macromolecule permeability of endothelial monolayers. PAF produced both a time- and dose-dependent increase in neutrophil-endothelial cell adhesion. The adhesion promoting properties observed were primarily due to an effect of PAF on endothelium and not on neutrophils and was independent of endothelial cell cyclooxygenase products. The PAF receptor antagonist kadsurenone inhibited the adhesion response suggesting endothelial surface PAF receptors are involved in these responses. Whereas PAF alone did not alter endothelial cell barrier properties, leukocyte activation (neutrophil and platelets) with PAF produced significant increases in 125I-albumin clearance across endothelial monolayers. These studies suggest that PAF has potent proinflammatory effects and that it can play a significant role in the endothelial response to injury.
Gaining ground: the impact of Medicaid and WIC on infant mortality.

This research provides a statistical estimation of the impact of the Medicaid and WIC programs on the infant mortality rate in the United States. These programs are designed to improve the health o...
Quasi-associative operations in the combination of evidence

Quasi‐associative operators are defined and suggested as a general structure useful for representing a class of operators used to combine various pieces of evidence. We show that both averaging operators and Dempster‐Shafer combining operators can be represented in this new framework.
Measurement of inertial particle clustering and relative velocity statistics in isotropic turbulence using holographic imaging

We present the first measurements of relative velocity statistics of inertial particles in a homogeneous isotropic turbulent flow with three-dimensional holographic particle image velocimetry (holographic PIV). From the measurements we are able to obtain the radial relative velocity probability density function (PDF) conditioned on the interparticle separation distance, for distances on the order of the Kolmogorov length scale. Together with measurements of the three-dimensional radial distribution function (RDF) in our turbulence chamber, these statistics, in principle, can be used to determine interparticle collision rates via the formula derived by Sundaram and Collins (1997). In addition, we show temporal development of the RDF, which reveals the existence of an extended quasi-steady-state regime in our facility. Over this regime the measured two-particle statistics are compared to direct numerical simulations (DNS) with encouraging qualitative agreement. Statistics at the same Reynolds number but different Stokes numbers demonstrate the ability of the experiment to correctly capture the trends associated with particles of different inertia. Our results further indicate that even at moderate Stokes numbers turbulence may enhance collision rates significantly. Such experimental investigations may prove valuable in validating, guiding and refining numerical models of particle dynamics in turbulent flows.
Peer and family group history: Implications for treatment

Peer and family group history of the patient and group leader have a powerful impact on the treatment process. An overview of the literature supports the influence of both the peer and family systems on personality development. A model is presented to help the clinician to integrate how family and peer group experiences may impact the patients' response to group psychotherapy.
DoE Method for Operating Parameter Optimization of a Dual-Fuel BioEthanol/Diesel Light Duty Engine

In recent years, alcoholic fuels have been considered as an alternative transportation biofuel even in compression ignition engines either as blended in diesel or as premixed fuel in the case of dual-fuel configuration. Within this framework, the authors investigated the possibility to improve the combustion efficiency when ethanol is used in a dual-fuel light duty diesel engine. In particular, the study was focused on reducing the HC and CO emissions at low load conditions, acting on the most influential engine calibration parameters. Since this kind of investigation would require a significant number of runs, the statistical design of experiment methodology was adopted to reduce significantly its number. As required by the DoE approach, a set of factors (injection parameters, etc.) were selected. For each of them, two levels “high” and “low” were defined in a range of reasonable values. Combining the levels of all the factors, it was possible to evaluate the effects and the weight of each factor and of their combination on the outputs. The results identified the rail pressure, the pilot, and post-injection as the most influential emission parameters. Significant reductions of unburnt were found acting on those parameters without substantial penalties on the global engine performances.
A New Start for Protein Synthesis

Recent technical advances have led to the accumulation of vast amounts of DNA sequences, highlighting the importance of understanding how the information in DNA is translated into amino acids and proteins. To decipher this information, the cell first transcribes a “coding” segment of DNA into messenger RNA (mRNA). Next, the ribosome decodes the mRNA in blocks of three consecutive nucleotides, or codons, that each specify an amino acid. But, how does the ribosome know where to start reading on the mRNA? To ensure faithful translation, and thereby yield a functional protein, cells restrict translation initiation to AUG codons that specify the amino acid methionine (Met). In mammals and other eukaryotic cells, translation typically initiates at the AUG codon closest to the beginning of the mRNA. But on page 1719 of this issue, Starck et al. ( 1 ) show that in addition to the canonical AUG-methionine initiation pathway, CUG-leucine can also be used to initiate protein synthesis.
Flow Measurements in a First Stage Nozzle Cascade Having Leakage and Assembly Features: Effects of Endwall Steps and Leakage on Aerodynamic Losses

This work supports new gas turbine designs for improved performance by evaluating endwall leakage and assembly features in a cascade that is representative of a first stage stator passage. The present paper documents component misalignment and leakage flow effects on the aerodynamic losses within a passage having one contoured and one straight endwall. Steps on the endwall and leakage flows through the endwall can lead to thicker endwall boundary layers, stronger secondary flows and possibly additional vortex structures in the passage. The paper compares losses with steps of various geometries and leakage of various flow rates to assess their importance on aerodynamic losses in this contoured passage. In particular, features associated with the combustor-to-turbine transition piece and the slash-face gap, a gap between two vane segments on the vane platform, are addressed.Copyright © 2005 by ASME
A pulse radiolysis study of the oxidation of methyl substituted ascorbates

The oxidations of 1-O-methyl-L-ascorbic acid, 2-O-methyl-L-ascorbic acid, 3-O-methyl-L-ascorbic acid, and 2,3-di-O-methyl-L-ascorbic acid byṡOH radicals and Br2⨪ were studied by pulse radiolysis. All three mono-substituted ascorbates react with Br2⨪ to form the corresponding ascorbate free radicals; 1-O-MeAṡ, 2-O-MeAṡ and 3-O-MeAṡ. In reactions with ṡOH radicals these compounds first form adducts, some of which subsequently yield the aforementioned free radicals while others yield unidentified transients and/or products. Proposed reaction mechanisms for these systems are supported by HPLC studies.
Contemporary Research on Social Movements and Protest in Latin America: Promoting Democracy, Resisting Neoliberalism, and Many Themes in between

This essay outlines how research on Latin American social movements has evolved since the late 1980s. Emphasis is given to two topics. First, the essay examines how Latin American social movement research has historically been oriented toward social movement theories that emerged out of the study of European movements and, to a lesser extent, movements in the United States. At the same time, it discusses how the unique historical and contextual factors of Latin American societies have repeatedly been found to defy adequate explanation by these theories. Second, the essay outlines five major themes that characterize the Latin American social movement literature: the dynamics of movements in relation to transitions to democracy, and to neo-liberal economic reforms, as well as transnational movement dynamics, indigenous movements, and women's movements.
Can trauma surgeons manage mild traumatic brain injuries

Abstract Background Current practices suggest that patients with mild traumatic brain injuries (MTBI) receive neurosurgical consultations, while less than 1% require neurosurgical intervention. We implemented a policy of selective neurosurgical consultation with the hypothesis that trauma surgeons alone may manage such patients with no impact on patient outcomes. Methods Data from a level I trauma registry were analyzed. Patients with MTBI resulting in an intracranial hemorrhage of 1 cm or less and a Glasgow Coma Score of 13 or greater were included. Patients with additional intracranial injuries were excluded. Multivariate regression was used to determine the relationship between neurosurgical management and good neurologic outcomes, while controlling for injury severity, demographics, and comorbidities. Results Implementation of the neurosurgical policy significantly reduced the number of such consults (94% before vs 65% after, P Conclusions Implementation of a selective neurosurgical consultation policy for patients with MTBI reduced neurosurgical consultations without any impact on patient outcomes, suggesting that trauma surgeons can effectively manage these patients.
Experimental Investigation of the Multiple Scattering of a Polarized Laser Beam

In this paper the forward-scattered diffuse radiation produced by a circularly polarized laser beam impinging on a e nite plane-parallel scattering medium is studied experimentally. The radial variation of the forward-scattered Stokes vector is analyzed. Values of the degree of circular and linear polarization of the scattered radiation computed using experimental data are compared with values obtained using a Monte Carlo code. Trends with respect to the size parameters of the scatterers and the optical thickness are also presented. It was observed that the diffuse radiation is strongly polarized, even at large optical radii. This is true for all the size parameters and optical depths of the medium studied.
A REVIEW OF THE STATE-OF-THE-ART OF OIL SPILL FATE/BEHAVIOR MODELS

ABSTRACT The fate and behavior of spilled oil can be affected by nine physical, chemical, and biological processes: advection, spreading, evaporation, dissolution, emulsification, dispersion, auto-...
Determination of the substance P receptor antagonist CP-122, 721 in plasma by narrow-bore high-performance liquid chromatography-ionspray tandem mass spectrometry

A simple, highly sensitive and specific LC-MS-MS assay was developed for the determination of CP-122,721 (I) in rat and human plasma. I and a structural analog, CP-129,943 (II, internal standard), were extracted from plasma with methyl tert.-butyl ether (MTBE). The dried MTBE extracts were reconstituted and analyzed using a narrow-bore (2.1 mm I.D.) YMC basic HPLC column and a mobile phase of acetonitrile-20 mM ammonium acetate, pH 5 (50:50, v/v). Column effluents were monitored by ionspray tandem mass spectrometry. Multiple reaction monitoring (MRM) using the parent to product ion combinations of m/z 381 → 205 and 395 → 219 was used to quantitate I and II, respectively. The assay exhibited a linear dynamic range of 0.2–100 ng/ml. Absolute recoveries from plasma were above 80% for both I and II. The precision and accuracy values for the method were within ±3 and ±9%, respectively. Sample analysis times were less than 5 min from one injection to the next. The assay has proved to be applicable to the pharmacokinetic study of I in rats.
Elite and Participatory Policymaking: Finding Balance in a Case of National Forest Planning

In recent years many theorists and practitioners have called for more public involvement in policymaking and for greater citizen input in decisions. The move toward participatory and community-based approaches in policymaking can be seen as a backlash against more elitist technocratic, top-down models of decisionmaking. Using a case study of a successful National Forest planning exercise, this research investigated whether a participatory or elite model characterized the decisionmaking process. The findings indicated that neither an elite nor participatory model of decisionmaking dominated in the planning process; rather, both forms of aecisionmaking contributed to important elements in formulating this successful National Forest plan.
A computer technique for the solution of laue back reflection patterns of cubic crystals. Part I

A computer algorithm has been developed for the rapid solution of Laue back reflection patterns of cubic structures. Reflections of planes having indices (333) and lower are indexed directly without the use of special charts, nets or tables. The computational scheme compares the angles associated with reflections from the X-ray patterns and the true interplanar angles which are calculated by the program. Any film-to-specimen distance may be used and the systematic errors associated with measurement of this distance are minimized to determine the best value.
Columbus, kentucky, moves to a new location

After years of struggle with Mississippi floods a complete town moves to high ground nearly a mile away. Citizens exchange old sites for new
How to extract heavy quark and heavy lepton signals in neutrino-induced dilepton events

Abstract Several key tests for neutrino-produced dilepton events are presented which allow one to identify rather clearly new signals arising from heavy quarks or heavy leptons in the presence of a substantial charm background.
Toward the three-dimensional structure and lysophosphatidic acid binding characteristics of the LPA4/p2y9/GPR23 receptor: A homology modeling study

Abstract Lysophosphatidic acid (LPA) is a naturally occurring phospholipid that initiates a broad array of biological processes, including those involved in cell proliferation, survival and migration via activation of specific G protein-coupled receptors located on the cell surface. To date, at least five receptor subtypes (LPA 1–5 ) have been identified. The LPA 1–3 receptors are members of the endothelial cell differentiation gene (Edg) family. LPA 4 , a member of the purinergic receptor family, and the recently identified LPA 5 are structurally distant from the canonical Edg LPA 1–3 receptors. LPA 4 and LPA 5 are linked to G q , G 12/13 and G s but not G i , while LPA 1–3 all couple to G i in addition to G q and G 12/13 . There is also evidence that LPA 4 and LPA 5 are functionally different from the Edg LPA receptors. Computational modeling has provided useful information on the structure–activity relationship (SAR) of the Edg LPA receptors. In this work, we focus on the initial analysis of the structural and ligand-binding properties of LPA 4 , a prototype non-Edg LPA receptor. Three homology models of the LPA 4 receptor were developed based on the X-ray crystal structures of the ground state and photoactivated bovine rhodopsin and the recently determined human β 2 -adrenergic receptor. Docking studies of LPA in the homology models were then conducted, and plausible LPA binding loci were explored. Based on these analyses, LPA is predicted to bind to LPA 4 in an orientation similar to that reported for LPA 1–3 , but through a different network of hydrogen bonds. In LPA 1–3 , the ligand polar head group is reported to interact with residues at positions 3.28, 3.29 and 7.36, whereas three non-conserved amino acid residues, S114(3.28), T187(EL2) and Y265(6.51), are predicted to interact with the polar head group in the LPA 4 receptor models.
Organizational and Educational Considerations in Creating an Environment to Promote Optimal Development of High-Risk Neonates

Neonatology is a specialized area of pediatric practice for the physical or occupational therapist. The organization of a program for developmental services in a special care nursery, therefore, requires specialized knowledge and skills in neonatal medicine, assessment of development in early infancy, early intervention, parent education, and interdisciplinary interaction in the specialized setting of the intensive care nursery. This paper provides guidelines and a list of helpful resources for organizing developmental services in the special care nursery with the overall goal of creating an environment to promote optimal development of high-risk newborn infants. Topics included in the paper are: (1) the ecology of the intensive care nursery, (2) administrative considerations in organizing a developmental therapy program, and (3) educational needs of professionals and parents.
Surface modification of porous alumina membranes by collagen layers: Performance and characterization

Abstract In this study, surface properties of alumina microfiltration membranes were modified by spin coating the surface with thin layers of collagen while controlling other critical surface properties such as pore size and surface charge. Collagen was spin deposited in layers of 1, 3, 6 or 9 onto an alumina membrane surface and IR spectra confirmed the presence of collagen protein on the substrate layer. The surface topography and pore morphology were studied using atomic force microscopy and scanning electron microscopy and revealed that the alumina surfaces were covered with collagen even for the single layer modification. The contact angle values for alumina membrane surfaces were measured to be 38 ± 6°, whereas the contact angle increased to 78 ± 6° when six layers of collagen were spun onto the membranes. The zeta potential of alumina membranes at a pH of 5.5 was 27 mV, whereas it decreased to 8 mV when 9 layers were spun onto the surface. The average pure water permeability was 7 × 10 −6 m/(s kPa) for the sulfuric acid-etched alumina membrane, and decreased after collagen was deposited. The pure water flux at 207 kPa for sulfonated alumina was 14 × 10 −4 m/s, but the flux dropped by nearly 50% for 3 layer membranes to 7 × 10 −4 m/s, and by roughly 95% (to 0.7 × 10 −4 m/s)) for 6 and 9 spun-on layers. The molecular weight cut off of the 3-layer modified membranes was 270 kDa and decreased to 80 kDa (6 layers) and 50 kDa (9 layers) as collagen layers increased. Permeability, flux and MWCO values for the collagen-coated membranes are comparable to ultrafiltration and loose nanofiltration membranes, and are expected to be suitable for biomolecular separations.
Cognitive impairment in congestive heart failure?: Embolism vs hypoperfusion.

Congestive cardiac failure ranks second after atrial fibrillation in cardiogenic stroke risk, with a two- to threefold relative risk.1 This relative risk is over fourfold among those 50 to 59 years of age, diminishing to about 1.5 by age 80 to 89 years. As in atrial fibrillation, stroke in cardiac failure is predominantly cardioembolic and, in the case of multiple emboli, may lead to dementia.2 The cause of these emboli is likely systolic dysfunction of the left ventricle causing an increased end diastolic volume and stasis, predisposing to thrombus formation (12% of patients with cardiomyopathy have left ventricular thrombi3). In patients with heart failure, ejection fraction is the most important predictor of risk: low ejection fraction is a risk factor for cerebral infarction4,5⇓ and ventricular thrombus formation.3 In addition to multiple cerebral emboli, another possible cause of cognitive impairment in heart failure is decreased cerebral perfusion. Systolic dysfunction of the left ventricle reduces …
Collaborative study to establish a proficiency panel of hepatitis B surface antigens for evaluating in vitro diagnostics

Hepatitis B virus (HBV) infection is a critical health issue. In hospitals, in vitro diagnostic devices (IVDs) are used to detect HBV infections. The Taiwan Food and Drug Administration has prepared a candidate hepatitis B surface antigen (HBsAg) proficiency panel as an analytical standard to evaluate the sensitivity of the postmarketing surveillance of HBV IVDs. The sensitivity and stability of the proficiency panel, which comprises 5 HBsAg positive sera (SN-A to E) and 1 negative serum, was determined by a collaborative study involving 8 collaboratories. The potency of the candidate proficiency panel was consistent among all collaboratories. The potencies of sera SN-A to E in semiquantitative and quantitative analyses were 2.823-0.011 and 2.229-0.009 IU/mL, respectively. The mean coefficients of variation (CV) of intra and interday precision among the collaboratories were <7%. Accelerated degradation and long-term storage tests were used as stability assays. The candidate HBsAg proficiency panel exhibited good stability under different storage conditions, while all CVs were <6%. In conclusion, this candidate HBsAg proficiency panel is credible and reliable. Therefore, it can be used for postmarketing surveillance of HBV IVDs and quality assessment by clinical researchers and IVD manufacturers.
Note on eigenvalue bounds for the Orr-Sommerfeld equation

Bounds for the complex wave velocity c , determined by the Orr-Sommerfeld equation and the boundary conditions for channel flow, have been given by Joseph (1968 a,b ). In these notes it is shown how two of Joseph's theorems can be uniformly improved.
Trust-region based solver for nonlinear transport in heterogeneous porous media

We describe a new nonlinear solver for immiscible two-phase transport in porous media, where viscous, buoyancy, and capillary forces are significant. The flux (fractional flow) function, F, is a nonlinear function of saturation and typically has inflection points and can be non-monotonic. The non-convexity and non-monotonicity of F are major sources of difficulty for nonlinear solvers of coupled multiphase flow and transport in natural porous media. We describe a modified Newton algorithm that employs trust regions of the flux function to guide the Newton iterations. The flux function is divided into saturation trust regions delineated by the inflection, unit-flux, and end points. The updates are performed such that two successive iterations cannot cross any trust-region boundary. If a crossing is detected, the saturation value is chopped back to the appropriate trust-region boundary. The proposed trust-region Newton solver, which is demonstrated across the parameter space of viscous, buoyancy and capillary effects, is a significant extension of the inflection-point strategy of Jenny et al. (JCP, 2009) [5] for viscous dominated flows. We analyze the discrete nonlinear transport equation obtained using finite-volume discretization with phase-based upstream weighting. Then, we prove convergence of the trust-region Newton method irrespective of the timestep size for single-cell problems. Numerical results across the full range of the parameter space of viscous, gravity and capillary forces indicate that our trust-region scheme is unconditionally convergent for 1D transport. That is, for a given choice of timestep size, the unique discrete solution is found independently of the initial guess. For problems dominated by buoyancy and capillarity, the trust-region Newton solver overcomes the often severe limits on timestep size associated with existing methods. To validate the effectiveness of the new nonlinear solver for large reservoir models with strong heterogeneity, we compare it with state-of-the-art nonlinear solvers for two-phase flow and transport using the SPE 10 model. Compared with existing nonlinear solvers, our trust-region solver results in superior convergence performance and achieves reduction in the total Newton iterations by more than an order of magnitude together with a corresponding reduction in the overall computational cost.
Flexible Demand Systems with Serially Correlated Errors: Fat and Oil Consumption in the United States

A flexible demand system proposed by Lewbel is used to estimate U.S. fat and oil demand from 1950 to 1986. Results suggest that the Lewbel model outperforms the Translog and AIDS and that correction for serial correlation is important. Findings also suggest that price and income effects, together with increasing public health concerns, primarily determine U.S. fat and oil demand.
Synthesis of Cinacalcet congeners

Abstract Two racemic isomeric dihydronaphthalenes 1 and 2 were prepared from commercially available 5-hydroxytetralone in five linear steps. A key palladium-catalyzed double bond migration led to the synthesis of both isomers from the same starting material. Preparative chiral HPLC separation provided the enantiomerically pure materials. An asymmetric synthesis employing CBS reduction to furnish 1 was also developed.
Ground-state properties of simple elements from GW calculations

A self-consistent implementation of Hedin's GW perturbation theory is introduced. This finite-temperature method uses Hartree-Fock wave functions obtained with full potential linear augmented plane-wave method to represent Green's function. With our approach we are able to calculate total energy as a function of the lattice parameter. Ground-state properties calculated for Na, Al, and Si compare well with experimental data.
On dynamic response of prestressed cylindrical shells—Green's tensor technique

Abstract The integral solution for the displacement vector of the mid-surface of a finite, simply supported thin circular cylindrical shell with initial biaxial stress subjected to arbitrary three dimensional time-dependent surface loadings has been derived in terms of the associated Green's tensor kernel based upon Flugge's equations. As direct applications, this paper presents theoretical analyses for (a) the dynamic response of a prestressed cylindrical shell due to a cyclic traveling axially-symmetric ring load and (b) the transient and steady-state response of a prestressed shell subjected to a cyclic moving point force. It is found that in both problems there exists theoretically an infinite number of load movement frequencies to resonantly excite each mode of vibration of the shell, either with or without initial stress. The general dynamic solution of prestressed shells together with the Green's tensor representation and the analytic solutions for the specific problems are also valid for Donnell's equations, if definition of some coefficients is properly adjusted.
Amino acid sequence of the signal peptide of mitochondrial nicotinamide nucleotide transhydrogenase as determined from the sequence of its messenger RNA.

The amino acid sequence of the bovine mitochondrial nicotinamide nucleotide transhydrogenase was recently deduced from isolated cDNAs and reported [Yamaguchi, M., Hatefi, Y., Trach, K., and Hoch, J.A. (1988) J. Biol. Chem. 263, 2761-2767]. The cDNAs lacked the N-terminal coding region, however, and the 8 N-terminal residues were determined by protein sequencing. In the present study, the nucleotide sequence of the 5' upstream region was determined by dideoxynucleotide sequencing of the transhydrogenase messenger RNA, and amino acid sequences of the N-terminal region and the signal peptide of the enzyme were deduced from the nucleotide sequence. The N-terminal sequence of the enzyme as deduced from the mRNA sequence is the same as that determined by protein sequencing, with one difference. Protein sequencing showed Ser as the N-terminal residue. The mRNA sequence indicated that Ser is the second N-terminal residue, and the first is Cys. That preparations of the enzyme are mixtures of two polypeptides, one polypeptide being one residue shorter at the N terminus than the other, has been pointed out in the above reference. The signal peptide consists of 43 residues, is rich in basic (4 Lys, 2 Arg) and hydroxylated (4 Thr, 3 Ser) amino acids, and lacks acidic residues.
On the instability of a three-layer atmosphere with an isentropic stratosphere

The linearized stability problem for a three-layer model, with an isentropic stratosphere as the uppermost layer, is studied. The model consists of soft tropopause and mid-tropospheric front. By making the tropopause rigid or by shrinking the depth of the stratosphere to zero one obtains the symmetric two-layer model. By eliminating the tropopause one obtains an asymmetric two-layer model. Both cases ? = 0 and ? ? 0 are considered for three-layer model. The structure of a growing wave and its physical interpretation are given for a three-layer model ? = 0 case. DOI: 10.1111/j.2153-3490.1972.tb01557.x
Acute Toxicity of the Insecticide Sevin® and Its Hydrolytic Product 1-Naphthol to Some Marine Organisms

Abstract The acute toxicity of Sevin® (1-naphthyl N-methylcarbamate) and its hydrolytic product 1-naphthol to 10 species of marine animals was determined. Sevin was more toxic to larval and adult crustaceans (Upogebia pugettensis, Callianassa californiensis, Hemigrapsus oregonensis, Cancer magister) than to larval and adult mollusks (Mytilus edulis, Crassostrea gigas, Clinocardium nuttallii) and juvenile fishes (Cymatogaster aggregata, Parophrys vetulus, Gasterosteus aculeatus). Sevin was 30 to 300 times more toxic than 1-naphthol to the crustaceans but less toxic than 1-naphthol to the mollusks and fishes.
Offshoring: what can go wrong?

Offshoring has sustained much criticism, mainly over the issue of whether shipping IT work abroad is good for the US as a whole. Does it benefit a US firm to offshore its IT work - specifically software development and maintenance? This paper discusses several reasons for firms to be wary of this practice. For some managers, these considerations might tip the balance against offshoring. For those who wish to offshore anyway, this article can serve as a map of the pitfalls to try to avoid.
Melanopsin retinal ganglion cells receive bipolar and amacrine cell synapses

Melanopsin is a novel opsin synthesized in a small subset of retinal ganglion cells. Ganglion cells expressing melanopsin are capable of depolarizing in response to light in the absence of rod or cone input and are thus intrinsically light sensitive. Melanopsin ganglion cells convey information regarding general levels of environmental illumination to the suprachiasmatic nucleus, the intergeniculate leaflet, and the pretectum. Typically, retinal ganglion cells communicate information to central visual structures by receiving input from retinal photoreceptors via bipolar and amacrine cells. Because melanopsin ganglion cells do not require synaptic input to generate light-induced signals, these cells need not receive synapses from other neurons in the retina. In this study, we examined the ultrastructure of melanopsin ganglion cells in the mouse retina to determine the type (if any) of synaptic input these cells receive. Melanopsin immunoreaction product was associated primarily with the plasma membrane of (1) perikarya in the ganglion cell layer, (2) dendritic processes in the inner plexiform layer (IPL), and (3) axons in the optic fiber layer. Melanopsin-immunoreactive dendrites in the inner (ON) region of the IPL were postsynaptic to bipolar and amacrine terminals, whereas melanopsin dendrites stratifying in the outer (OFF) region of the IPL received only amacrine terminals. These observations suggested that rod and/or cone signals may be capable of modifying the intrinsic light response in melanopsin-expressing retinal ganglion cells.
Delirium in liver transplantation candidates: discriminant analysis of multiple test variables.

We report the results of electroencephalograms, Mini-Mental State exam, Trailmaking Tests A and B, and serum albumin levels in 108 consecutive liver transplantation candidates. We compared test results to a clinical DSM-III diagnosis of delirium. Although each variable could differentiate between the two groups (delirium n = 18; nondelirium n = 90) at a statistically significant level, a discriminant analysis involving either all variables or only three particular variables (Trailmaking B, EEG code, and albumin) resulted in the highest specificity (97.8%) and sensitivity (83.3%), with a correct classification of 95.4% of subjects. The analysis also generates an equation that can be applied to clinical situations to enhance the accurate recognition of delirium. In addition, to explain abnormal Trailmaking B scores and/or EEGs in subjects who did not otherwise meet DSM-III criteria for delirium, we suggest the presence of a "subclinical delirium."