cssi/SciSciGPT-SciSciNet huggingface dataset:
Arsenite oxidation by a poorly crystalline manganese-oxide. 2. Results from X-ray absorption spectroscopy and X-ray diffraction.

Arsenite (AsIII) oxidation by manganese oxides (Mn-oxides) serves to detoxify and, under many conditions, immobilize arsenic (As) by forming arsenate (AsV). AsIII oxidation by MnIV-oxides can be qu...
Effects of agents altering vascular calcium in experimental atherosclerosis.

Abstract Rabbits fed a 2 % by weight cholesterol diet developed fatty, intimal lesions in the aorta. When animals were given the same diet plus 0.1 mg reserpine/kg/day, 1.0 mg guanethidine/kg/day, 0.1 mg/kg/day of SU-7064, a reserpine analogue with hypotensive properties or 0.1 mg/kg/day of SU-9064 a reserpine analogue with no hypotensive properties, the intimal lesions were smaller and fat deposition was diminished. There was a gradual rise in the food consumption and at no time in the experiment was there any significant difference in the food intake of any of the groups. There was a gradual increase in body weights of all groups and as the experiment progressed. There was no significant difference in the weights of the rabbits of any experimental groups. Tissue calcium content of the aortae of the groups which received reserpine, the two reserpine analogues and 1.0 mg guanethidine/kg/day was significantly lower than that of normal rabbits or the 2 % cholesterol group. The effect of these drugs appears to be elicited by lowering the calcium content of the aortae.
First-line therapy of chronic myeloid leukemia – focus on dasatinib

Correspondence: Philip C Amrein Hematology-Oncology, Massachusetts General Hospital, 100 Blossom Street, Boston, MA 02114, USA Email pamrein@partners.org Abstract: Dasatinib is a broad spectrum, ATP-competitive, tyrosine kinase inhibitor with low nM activity against Bcr-Abl, Src, and other tyrosine kinases. This activity has allowed dasatinib to emerge as one of the most effective agents in the treatment of chronic myeloid leukemia (CML), and dasatinib has become the third drug over the past 10 years to be FDA approved for first line therapy in this setting. This review consists of papers and reports that recount the recent dramatic progress that has been made in the understanding of CML on a molecular basis leading up to the new targeted therapies, especially the use of dasatinib. As with any drug, treatment with dasatinib has risks and side effects, especially pleural effusions and anti-platelet effects, as outlined in recently published studies. Of interest are the reports of alternative doses and schedules that may be able to circumvent some of these side effects without compromising the effectiveness of this drug. This review outlines the mode of action, pharmacology, effectiveness, and safety of dasatinib in the treatment of CML, and by comparing dasatinib directly with the other tyrosine kinase inhibitors effective in CML, it describes the place in therapy that dasatinib currently holds.
On the Purported Synonymy of Piona reighardi (Wolcott, 1902) with Piona rotunda (Kramer, 1879) (Acarina: Pionidae)

Life-history studies based on material collected in Ohio indicate that these are two distinct species, so that their recent synonymization by Cook was unwarranted. Eggs laid by Piona rotunda in the laboratory yielded nymphs, rather than larvae, upon hatching. Larvae and nymphochrysalids infesting midges, Tendipes decorus (Joh.), upon hatching were correlated with Piona reighardi , and these nymphs were morphologically distinct from reared and field-collected nymphs of P. rotunda . Morphological distinctions in the adults are more evident in males than in females.
Implementation and Flight Test Results of MILP-based UAV Guidance

This paper discusses the implementation of a guidance system based on mixed integer linear programming (MILP) on a modified, autonomous T-33 aircraft equipped with Boeing's UCAV avionics package. A receding horizon MILP formulation is presented for safe, real-time trajectory generation in a partially-known, cluttered environment. Safety at all times is guaranteed by constraining the intermediate trajectories to terminate in a loiter pattern that does not intersect with any no-fly zones and can always be used as a safe backup plan. Details about the real-time software implementation using CPLEX and Boeing's OCP platform are given. A test scenario developed for the DARPA-sponsored software enabled control capstone demonstration is outlined, and simulation and flight test results are presented
Fostering Cross Cultural Competence in Preservice Teachers Through Multicultural Education Experiences

Diversity is increasing in our classrooms implying the need for teachers to be prepared to work effectively with students from different backgrounds, such as cultural, linguistic or national origin. Additionally, the focus on diversity education is important because of the need for students to develop, from an early age, the ability to communicate with and relate to others from diverse backgrounds. This article focuses on cross cultural experiences gained from cross cultural partnerships between preservice teachers and English Language Learners over the course of a semester at a medium size public university. Evidence from this project suggests the need for teacher educators to model and support appropriate cultural competencies that are critical in classrooms that are fast becoming more culturally as well as linguistically diverse.
Process dynamic models for heterogeneous chemical reactors - an application of dynamic singularity theory

Abstract By analyzing bifurcations from the marginal gain settings of a nonlinear reactor under PI-control, several characteristics of the closed-loop reactor dynamics are revealed via the center manifold projection and normal form techniques of dynamic singularity theory. Of particular practical interests are the effects of set-point error which can often destabilize a nonlinear reactor. It is shown that judicious choice of the set-point developed here can reduce such undesirable effects. The analysis also offers extremely low dimensional nonlinear models which faithfully reproduce all the closed-loop dynamics and are especially accurate near the marginal gains. These reduced models are hence ideal for the design and tuning of reactor controllers.
The role of renal scintigraphy in the evaluation of spinal cord injury patients with presumed urosepsis.

AbstractPurpose: We attempted to differentiate pyelonephritis, defined as upper urinary tract parenchymal infection, from fever due to other sources in patients with spinal cord injury by radioisotope renal scintigraphy.Materials and Methods: A total of 13 consecutive spinal cord injury patients 21 to 54 years old (level of injury C4 to cauda equina) was hospitalized with urosepsis. The diagnosis was based on medical history, physical examination and laboratory evaluation, including blood, urine, sputum and wound fluid culture and sensitivity, and a99m technetium glucoheptonate renal scan for pyelonephritis. Renal scan results were compared to 1 or more of several studies performed in each case, including ultrasonography, excretory urography and axial computerized tomography.Results: Glucoheptonate renal scintigraphy accurately diagnosed pyelonephritis in all 7 patients with a scintigraphic B lesion. In 2 patients with a C lesion on scintigraphy, representing a cortical scar, other sources of sepsis were ...
An independent component analysis approach for minimizing effects of recirculation in dynamic susceptibility contrast magnetic resonance imaging

In dynamic susceptibility contrast (DSC) perfusion-weighted imaging, effects of recirculation are normally minimized by a gamma-variate fitting procedure of the concentration curves before estimating hemodynamic parameters. The success of this method, however, hinges largely on the extent to which magnetic resonance signal is altered in the presence of a contrast agent and a temporal separation between the first and subsequent passages of the contrast agent. Moreover, important physiologic information might be compromised by imposing an analytic equation to all measured concentration curves. This investigation proposes to exploit independent component analysis to minimize effects of recirculation in DSC. Results obtained from simulation, normal healthy volunteers, and acute stroke patients show that such a technique can greatly minimize the effects of recirculation despite a substantial overlap between the first passage and recirculation. This in turn should improve estimation of cerebral hemodynamics particularly when an overlap between the first passage and recirculation is suspected as in an ischemic lesion.
Language Characteristics of Children with ADHD

Language characteristics of 11 children with attention-deficit/ hyperactivity disorder (ADHD) and 11 typically developing children ages 6 to 8 were compared in terms of semantic, syntactic, and pragmatic language skills. Children were tested on the Peabody Picture Vocabulary Test-Revised (PPVT-R), the Test of Language Development-2 Primary (TOLD-2), and the Test of Pragmatic Language (TOPL). Samples of children's language were collected during free play with an adult conversational partner using the Pragmatic Protocol. Results indicated that there was no difference between the two groups on receptive vocabulary as measured by the PPVT-R. Children with ADHD performed worse than typically developing children on the sentence imitation, word articulation, speaking quotient, and overall speech and language quotient subtests of the TOLD-2 Primary. Children with ADHD produced more inappropriate pragmatic behaviors in conversational interactions, although their pragmatic knowledge as measured by the TOPL did not ...
Molecular Model of the Opsin-G-Protein Complex

A recent highlight in the structural biology of G-protein-coupled receptors includes the structural elucidation of opsin in an active-state conformation (Ops∗). We modeled the complex of opsin with the heterotrimeric G-protein transducin (Ops∗-Gtαβγ, figure below), using the NMR structure of an 11-residues peptide from the C-terminus of the alpha-subunit of transducin (GtαCT) and the crystal structures of opsin in its G-protein interacting conformation (Ops∗-GtαCTK341L), of rhodopsin in an inactive state, and of transducin (Gtαβγ•GDP). We reconstructed the C-terminal α5 helix of Gtα and docked it to the open binding site in Ops∗. It has been proposed that a 40°-tilt of Gtαβγ relative to the α5 helix is necessary to avoid steric clashes between Gtβγ and the membrane. We propose an alternative model without these massive changes in α5 helix packing. With an alternative conformation of the intra-cellular loop connecting helix 5 and helix 6 in Ops∗ it is possible to obtain a model that maintains the Ops∗-induced αL-type C-capping conformation of GtαCT and its key interactions with Ops∗. The model will be used for detailed MD simulations of the complex in the membrane and to design cross-linking experiments for biochemical validation.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Chromatography of adrenocortical steroids on silicic acid columns.

Abstract The effect of variable parameters, such as water content and activation, on the separation of adrenocortical steroids on silicic acid columns was studied. Screening of nine commercial silicic acid samples, using a standard technique of partition chromatography, showed wide variations in chromatographic behavior. Data is presented on the effects of varying stationary phase (water) and activation on separation and recovery of eight adrenocortical steroids. A standardized technique for preparation of an efficient and reproducible partition column for the separation of steroid mixtures on one of the commercially available silicic acids is described.
Free-radical model for coal conversions. Effect of conversion level and concentration on thermolysis of bibenzyl☆

Abstract The product distributions from thermolysis of bibenzyl at 366 °C and 400 °C have been determined as a function of conversion level and of bibenzyl concentration from the dilute gas to the neat liquid. At very low (1–3%) conversion levels, five primary products have been detected: toluene ( 2 ), stilbene ( 3 ), 1,2,3-triphenylpropane ( 4 ), 1,2,3,4-tetraphenylbutane ( 5 ), and 1,1-diphenylethane ( 6 ). Increasing the concentration of bibenzyl decreases the ratio 4:5 and increases the amount of rearrangement to 6 . This product behaviour is interpreted by a multistep, nonchain, free-radical network involving initial formation of benzyl radicals by homolysis of bibenzyl, formation of 1,2-diphenylethyl radicals by hydrogen atom transfer, and subsequent coupling, disproportionation, and rearrangement of the radicals. At higher conversion levels, the primary product distribution is markedly perturbed because products 4 and 5 are inherently less stable than bibenzyl; additional, secondary products include diphenylmethane and phenanthrene.
Electrocardiographic indexes of dispersion of ventricular repolarization: An isolated heart validation study

Objectives. This study tested the correlation of QT and JT dispersion and other potentially useful electrocardiographic (ECG) indexes with dispersion of repolarization and recovery time. Background. Dispersion of ventricular repolarization is currently being assessed noninvasively from the surface ECG by means of QT and JT dispersion, although their correlation with dispersion of repolarization as measured directly from the myocardium is not well established. Methods. Multiple monophasic action potentials were recorded simultaneously with a 12-lead ECG from isolated Langendorff-perfused rabbit hearts. The QT and JT dispersion was compared with the dispersion of monophasic action potential duration at 90% repolarization (APD 90 ) and with dispersion of recovery time. As new ECG indexes, total T wave area, T wave area after the peak (late T wave area) and T peak to T end interval were also tested. Results. The QT and JT dispersion showed a significant correlation with the dispersion of APD 90 and the dispersion of recovery time (r values between 0.58 and 0.64, respectively, p 90 and recovery time (r = 0.79 and r = 0.82, p Conclusions. The JT and QT dispersion correlate significantly with dispersion of APD 90 and recovery time. The ECG assessment of dispersion of repolarization can be improved by three new ECG dispersion indexes: T peak to T end interval, total T wave area and late T wave area. These new indexes should be tested clinically.
Experimental Study of the Fatigue Resistance and Ultimate Capacity of a Hybrid FRP-Concrete Bridge Deck

The design and construction of bridge systems with long-term durability and low maintenance requirements is a significant challenge for bridge engineers. A possible solution to this challenge might exist through the use of new materials, i.e. fiber reinforced polymer (FRP) composites, combined with traditional materials that are arranged as an innovative hybrid structural system. An experimental investigation was conducted to gain an improved understanding of the long-term structural behavior and viability of a hybrid FRP-concrete (HFRPC) bridge deck system. This paper presents the results of fatigue and ultimate strength testing performed on a 3/4 scale bridge model consisting of a hybrid FRP-concrete bridge deck connected to supporting steel girders through shear stud clusters. The results of the fatigue and destructive testing suggest the hybrid FRP-concrete bridge deck might be a viable alternative to traditional cast-in-place reinforced concrete deck from a structural performance perspective. The specimen showed no degradation in stiffness or composite action between the deck and steel girders after 2 million cycles of dynamic loading with a peak load of 1.26 times the scaled tandem load and an ultimate capacity of 6 times the scaled tandem load.
Computer-aided design, Part 1 enhancing convergence properties by the choice of output variable assignments in the solution of Sparse equation sets

Abstract Techniques to guide one in choosing calculational schemes for sparse equation sets are being developed so a computer system can produce its own solution procedure—or subroutine—given a set of equations to be solved and the numbers occurring in the problem of interest. Previous work in this area has generally dealt only with the structural properties of the equation set. This paper presents a technique permitting the derived solution procedure to account directly for the problem numbers also. An algorithm results which also leads to a new method of obtaining structural information about the equation set.
The feasibility of measuring frailty to predict disability and mortality in older medical intensive care unit survivors

Abstract Purpose To determine whether frailty can be measured within 4 days prior to hospital discharge in older intensive care unit (ICU) survivors of respiratory failure and whether it is associated with post-discharge disability and mortality. Materials and Methods We performed a single-center prospective cohort study of 22 medical ICU survivors age 65 years or older who had received noninvasive or invasive mechanical ventilation for at least 24 hours. Frailty was defined as a score of ≥3 using Fried's 5-point scale. We measured disability with the Katz Activities of Daily Living. We estimated unadjusted associations between Fried's frailty score and incident disability at 1-month and 6-month mortality using Cox proportional hazard models. Results The mean (SD) age was 77 (9) years, mean Acute Physiology and Chronic Health Evaluation II score was 27 (9.7), mean frailty score was 3.4 (1.3), and 18 (82%) were frail. Nine subjects (41%) died within 6 months, and all were frail. Each 1-point increase in frailty score was associated with a 90% increased rate of incident disability at 1-month (rate ratio: 1.9, 95% CI 0.7-4.9) and a threefold increase in 6-month mortality (rate ratio: 3.0, 95% CI 1.4-6.3). Conclusions Frailty can be measured in older ICU survivors near hospital discharge and is associated with 6-month mortality in unadjusted analysis. Larger studies to determine if frailty independently predicts outcomes are warranted.
The counteradhesive protein SPARC regulates an endothelial paracellular pathway through protein tyrosine phosphorylation.

SPARC (Secreted Protein Acidic and Rich in Cysteine) regulates the transendothelial flux of macromolecules through a paracellular pathway. We now have demonstrated that SPARC-induced increments in albumin flux across postconfluent endothelial cell (EC) monolayers are mediated, in part, through protein tyrosine phosphorylation. SPARC increased tyrosine phosphorylation of EC proteins up to 12-fold within 1 h. The phosphotyrosine-containing proteins were immunolocalized to the intercellular boundaries. Two substrates for SPARC-induced tyrosine phosphorylation were identified as beta-catenin and paxillin. Inhibition of tyrosine kinases with herbimycin A or genistein reversed the barrier dysfunction induced by SPARC by 71% and 49%, respectively. Herbimycin A also protected against SPARC-induced intercellular gap formation. In contrast, inhibition of tyrosine phosphatases with sodium orthovanadate or phenylarsine oxide enhanced the loss of barrier function associated with SPARC treatment by 120% and 88%, respectively. These data indicate that SPARC influences EC-EC interactions through a tyrosine phosphorylation-dependent signaling pathway.
Dual ionic controls for the activation of protein synthesis at fertilization.

The general metabolic activation of the sea urchin egg at fertilization is dependent on a release of intracellular stores of calcium and the subsequent transient elevation of intracellular Ca2+ (refs 1–3). However, this elevation does not by itself lead to increased macromolecular synthesis and development but initiates steps which result in a long-term elevation of intracellular pH (refs 4–6). Among the developmental processes dependent on the elevation of intracellular pH is the large acceleration in the rate of protein synthesis at fertilization6. Weak penetrating bases such as ammonia can be used to mimic the processes resulting in an increase in intracellular pH and so show the corresponding increases in protein synthesis rate6–9. Conversely, it is possible to demonstrate a gradual but complete shut down of protein synthesis if the intracellular pH is reduced to the unfertilized level with penetrating weak acids6. However, the rate of protein synthesis in ammonia-activated eggs lags behind that of fertilized controls even though ammonia activation can result in an intracellular pH increase greater than occurs in the fertilized egg6,8,10. This result has led to the suggestion that factors other than intracellular pH may be regulating protein synthesis following fertilization6,10. To investigate the possibility that the Ca2+ transient may have such a role, we measured the rate of amino acid incorporation in eggs that were activated in various ionic conditions which enabled the effects of Ca2+ and pH changes to be studied separately. Our results, reported here, show that if intracellular pH is elevated, increases in intracellular Ca2+ play an additional part in the activation of protein synthesis at fertilization.
Uniqueness implies existence for three-point boundary value problems for second order differential equations

Abstract Shooting methods are employed to obtain solutions of the three-point boundary value problem for the second order equation, y ″ = f ( x , y , y ′ ) , y ( x 1 ) = y 1 , y ( x 2 ) − y ( x 3 ) = y 2 , where f : ( a , b ) × R 2 → R is continuous, a x 1 x 2 x 3 b , and y 1 , y 2 ∈ R , and it is assumed that solutions of such problems are unique, when they exist.
Coexpression of G-CSF with an Unglycosylated G-CSF Receptor Mutant Results in Secretion of a Stable Complex

Previously, we have shown that the entire extracellular domain of the granulocyte-colony stimulating factor receptor (sG-CSFr) produced in Chinese hamster ovary (CHO) cells forms a stable complex with its ligand G-CSF, at a stoichiometry of 2:2. A truncated receptor molecule consisting of the cytokine receptor homology domain and N-terminus Ig-like domain (Ig CRH) behaves quite similarly. Both of these forms of the receptor are highly glycosylated. To address the importance of glycosylation toward receptor activity and stability, and possibly obtain nonglycosylated receptor for crystallization, mutations were made to replace four Asn residues which are N-glycosylated in the truncated receptor. Virtually no receptor was recovered from conditioned media of CHO cells transfected with this mutant construct, although a high-level of mRNA coding for receptor was detected; this mRNA was translated as determined by Western blots of cell lysates. These results indicate that the translated product is apparently not secreted from these cells. Cells transfected with mutant receptor cDNA were cotransfected with a cDNA construct expressing G-CSF in which the single O-glycosylation site was eliminated by mutation. Upon fermentation of the cotransfectants, we observed a large amount of receptor-ligand complex in the conditioned media. The purified unglycosylated complex appeared to be of the same binding stoichiometry and approximate binding affinity as that of complex formed by addition of purified ligand and unmutated receptor. These results show that while glycosylation of sG-CSFr is not necessary for ligand binding, it appears to be crucial in folding and export from the cell.
New Partnerships in Global Environmental Policy: The Clean Development Mechanism:

Today’s fragmented world demands creative institutional arrangements to allow governments, international organizations, and civil society actors to join forces in addressing global environmental problems. This article discusses the Clean Development Mechanism (CDM) as foreseen under Article 12 of the Kyoto Protocol in the context of new models of governance. To do so, it depicts CDM’s history, institutional setting and participatory elements. The CDM serves as a concrete example of how new collaborative networks consisting of nation states and nonstate actors can help in implementing international treaties. The articles traces the history of the United Nations Framework Convention on Climate Change process to provide a sufficient background for a more detailed discussion of the CDM. On that basis, it provides an analysis of the CDM, and depict the Prototype Carbon Fund, administered by the World Bank, as an example for an innovative model of cooperation between the private and the public sectors.
Iterative natural orbitals for configuration interaction using perturbation theory

Approximate natural orbitals are determined iteratively from CI expansions constructed using first-order perturbation theory in order to investigate the possibility of eliminating the complete transformation of MO integrals on each iteration. Results on LiH and H2O are compared with fully variationally determined NO's to assess questions of convergence.
Microbial transport through porous media: The effects of hydraulic conductivity and injection velocity☆

Abstract The effects of hydraulic conductivity and injection velocity on microbial transport through porous media were investigated. Glass chromatography columns were packed separately with clean quartz sand of two diameters (0.368mm or 0.24O mm) and two hydraulic conductivities (1.37×10 −1 cm/s and 3.65×10 −2 cm/s respectively). Three injection velocities, 1.18×10 −3 , 2.35×10 −3 and 4.73×10 −3 cm/s were investigated. Microbial transport under the conditions tested was limited and could be predicted mathematically using a model for physicochemical filtration.
Integration of opto-fluidic microring resonator lasers for lab-on-a-chip development

In this work we present a method for creating an integrated optofluidic ring resonator (OFRR) laser system by embedding it in a low index polymer, polydimethylsiloxane (PDMS). Packaging the OFRR inside PDMS enhances portability, mechanical stability, and the ability to connect it to chip-based microfluidics. The OFRR retains high Q-factors even in the polymer (> 106) and exhibits a low lasing threshold (<1 μJ/mm2). Additionally, the laser emission can be efficiently and directionally coupled out through an optical fiber or fiber prism in touch with the ring resonator. At 2.2 μJ/mm2 pump intensity, the laser output from the fiber is 80 nW, corresponding to 50% power extraction efficiency. Our work will lead to novel design in lab-on-a-chip devices and micro total analysis systems for biological and chemical detection.
Development of a cell self-assembled 3-dimensional in vitro skeletal muscle tissue model

Skeletal muscle diseases such as Duchenne Muscular Dystrophy currently lack effective clinical treatments. Current research is focused on the development of in vitro model systems that mimic native muscle that can be used as a tool for high-throughput drug screening and diagnostics. Unfortunately, the current models fail to accurately mimic the morphological structure and functionality of native muscle. Our lab utilized a cell-seeding platform creating anchored skeletal muscle mimetic microtissues using nonadhesive micromolds that generate tissues containing native levels of cell density and viability. These tissues begin to express sarcomeric myosin during maturation but routinely fail as myosin production increases (~8-10 days postseeding). Future work includes optimizing culture conditions to further increase ECM and contractile protein production to near native levels along with incorporating mechanical conditioning using a custom-designed stimulation system to further strengthen and mature the tissue constructs.
Critical behavior of a KAM surface: I. Empirical results

Kolmogorov-Arnol'd-Moser (KAM) surfaces are studied in the context of a perturbed two-dimensional twist map. In particular, we ask how a KAM surface can disappear as the perturbation parameter is increased. Following Greene, we use cycles to numerically construct the KAM curve and discover that at the critical coupling it shows structure at all length scales. Aspects of this structure are fitted by a scaling analysis; critical indices and scaling functions are determined numerically. Some evidence is presented which suggests that the results are universal.
Temporal dynamics of airborne lead-210 in Missouri (USA): implications for geochronological methods

Lead-210 (210Pb) deposited from the atmosphere is used in the dating of certain geological materials such as glacial ice and lacustrine sediments, but its long-term atmospheric behavior has been little studied. The present investigation reports measurements of airborne 210Pb at 21 monitoring stations in Springfield, Missouri, during 1975–1995. Seasonal and diurnal patterns of atmospheric concentrations are established, and the mean annual concentrations of 210Pb in ground level air during the 20-year period are examined. Although airborne 210Pb concentrations are found to vary diurnally and seasonally, mean annual concentrations in southwest Missouri have remained relatively constant during this time period. This finding is important for geochronological methods that assume a constant 210Pb flux from the atmosphere.
The decay of a magnetohydrodynamic shock wave

On utilise l'analyse lineaire pour etudier les faibles perturbations non-isentropiques des equations relatives aux ecoulements unidimensionnels et non-stationnaires d'un fluide non visqueux ideal, parfaitement conducteur de l'electricite et compressible, soumis a l'action d'un champ magnetique transversal. On utilise la solution generale de la perturbation non-isentropique d'un ecoulement par ondes simples centrees pour determiner la perturbation qui se manifeste lorsqu'une onde de choc magnetohydrodynamique, tout d'abord uniforme et de force arbitraire, rencontre le regime d'onde simple.
Hydrologic trajectories in transient ground-penetrating-radar reflection data

A variable-rate infiltration experiment was conducted in a sandbox to demonstrate that distinctive patterns are produced in transient ground-penetrating-radar (GPR) data collected during wetting and drying events. The observed GPR response was found to be very consistent with the results of numerical simulations performed using finite-difference time-domain modeling of GPR coupled with a 1D unsaturated flow model (HYDRUS-1D) for which the sand hydraulic properties were determined independently using core samples. Despite this agreement, few methods are available that can efficiently analyze transient GPR data to make a quantitative link between observed responses and the hydraulic properties of soils. To address this problem, a computationally efficient method is proposed that is analogous to coherency analysis used in multioffset surveys. The new method isbased on the calculation of semblance along trajectories through transient GPR data. Each trajectory represents a specific GPR arrival, e.g., the ground wave and reflections from the wetting front and subsurface boundaries. The specific path of the trajectories is controlled by the hydraulic properties of the soil, just as the normal-moveout trajectories used to calculate semblance in multioffset data are controlled by wave velocity. Because the method is based on the output of 1D unsaturated flow models, it can be used for situations with complex hydrologic boundary conditions. Good agreement was found in this study between the calculated trajectories and the arrivals observed for both simulated and empirical GPR data. A sensitivity analysis performed in this study suggests that most parameters of the Mualem–van Genuchten soil model can be identified using this approach to coherency analysis of transient GPR data.
Hybrid integrated photonic components based on a polymer platform

We report on a polymer-on-silicon optical bench platform that enables the hybrid integration of elemental passive and active optical functions. Planar polymer circuits are produced photolithographically, and slots are formed in them for the insertion of chips and films of a variety of materials. The polymer circuits provide interconnects, static routing elements such as couplers, taps, and multi/demultiplexers, as well as thermo-optically dynamic elements such as switches, variable optical attenuators, and tunable notch filters. Crystal-ion-sliced thin films of lithium niobate are inserted in the polymer circuit for polarization control or for electro-optic modulation. Films of yttrium iron garnet and neodymium iron boron magnets are inserted in order to magneto-optically achieve non-reciprocal operation for isolation and circulation. Indium phosphide and gallium arsenide chips are inserted for light generation, amplification, and detection, as well as wavelength conversion. The functions enabled by this multi-material platform span the range of the building blocks needed in optical circuits, while using the highest-performance material system for each function. We demonstrated complex-functionality photonic components based on this technology, including a metro ring node module and a tunable optical transmitter. The metro ring node chip includes switches, variable optical attenuators, taps, and detectors; it enables optical add/drop multiplexing, power monitoring, and automatic load balancing, and it supports shared and dedicated protection protocols in two-fiber metro ring optical networks. The tunable optical transmitter chip includes a tunable external cavity laser, an isolator, and a high-speed modulator.
Docosahexaenoic acid elevates trans-18:1 isomers but is not directly converted into trans-18:1 isomers in ruminal batch cultures

Abstract Pathways of docosahexaenoic (DHA) biohydrogenation are not known; however, DHA is metabolized by ruminal microorganisms. The addition of DHA to the rumen alters the fatty acid profile of the rumen and milk and leads to increased trans -18:1 isomers, particularly trans -11 18:1. This study included 2 in vitro experiments to identify if the increase in trans -11 C18:1 was due to DHA being converted into trans -11 18:1 or if DHA stimulated trans -11 products from biohydrogenation of other fatty acids. In each experiment, ruminal microorganisms collected from a lactating Holstein cow were incubated in 10-mL batch cultures for 0, 6, 24, and 48h and a uniformly 13 C-labeled DHA was added to the cultures at 0h as a metabolic tracer. Experiment 1 tested 0.5% DHA supplementation and experiment 2 examined 1, 2, and 3% DHA supplementation to determine if the level of DHA effected its conversion into trans -11 18:1. In both experiments, any fatty acid that was enriched with the 13 C label was determined to arise from DHA. Palmitic (C16:0), stearic (C18:0), all trans -18:1, eicosanoic (C20:0), and docosanoic (C22:0) acids were examined for enrichment. In experiment 1, the amount of trans -18:1 isomers increased 0.415mg from 0 to 48h; however, no label was found in trans -18:1 at any time. Docosanoic acid was highly enriched at 24h and 48h to 20.2 and 16.3%. Low levels of enrichment were found in palmitic and stearic acids. In experiment 2, trans -18:1 isomers increased 185, 256, and 272% from 0 to 48h when DHA was supplemented at 1, 2, and 3%, respectively; however, as in experiment 1, no enrichment occurred of any trans -18:1 isomer. In experiment 2, low levels of label were found in palmitic and stearic acids. Enrichment of docosanoic acid decreased linearly with increased DHA supplementation. These studies showed that trans -18:1 fatty acids are not produced from DHA, supporting that DHA elevates trans -18:1 by modifying biohydrogenation pathways of other polyunsaturated fatty acids.
Scrub-Shrub Bird Habitat Associations at Multiple Spatial Scales in Beaver Meadows in Massachusetts

Abstract.— Most scrub-shrub bird species are declining in the northeastern United States, and these declines are largely attributed to regional declines in habitat availability. American Beaver (Castor canadensis; hereafter “beaver”) populations have been increasing in the Northeast in recent decades, and beavers create scrub-shrub habitat through their dam-building and foraging activities. Few systematic studies have been conducted on the value of beaver-modified habitats for scrub-shrub birds, and these data are important for understanding habitat selection of scrub-shrub birds as well as for assessing regional habitat availability for these species. We conducted surveys in 37 beaver meadows in a 2,800-km2 study area in western Massachusetts during 2005 and 2006 to determine the extent to which these beaver-modified habitats are used by scrub-shrub birds, as well as the characteristics of beaver meadows most closely related to bird use. We modeled bird abundance in relation to microhabitat-, patch-, and...
Thyroid function and related hepatic enzymes in the germfree rat.

Abstract The adult germfree rat has a low metabolic rate, and the activity of various hepatic enzymes differs substantially from values found in the conventional animal. To promote understanding of the shifts in intermediary metabolism apparent in the germfree rodent, parameters of thyroid function and the activity of three enzyme systems presumably influenced by thyroid function were determined in 40-, 60-, and 100-day-old male germfree and conventional Lobund rats of Wistar origin. Serum thyroxine concentrations generally increased with age. They were below normal levels in 40- and 60-day-old germfree rats but appeared normal in the 100-day-old germfree animal. Serum thyroxine-binding protein saturation levels were significantly reduced in germfree rats of all age groups, but the reduction was least in the 100-day-old group. Mitochondrial succinate oxidase and α-glycerophosphate dehydrogenase activities were lower in livers of germfree rats of all age groups, although the significance of the difference in succinic oxidase activity became less in older animals. Monoamine oxidase activity was similar in germfree and conventional animals. Although the data suggest a hypofunction of the thyroid in the immature germfree rat, no definite relation between thyroid function and the characteristic metabolic anomalies of the germfree rat could be established.
Increased inbreeding but not homozygosity in small populations of Sabatia angularis (Gentianaceae)

Understanding how the mating system varies with population size in plant populations is critical for understanding their genetic and demographic fates. We examined how the mating system, characterized by outcrossing rate, biparental inbreeding rate, and inbreeding coefficient, and genetic diversity varied with population size in natural populations of the biennial Sabatia angularis. We found a significant, positive relationship between outcrossing and population size. Selfing was as high as 40% in one small population but was only 7% in the largest population. Despite this pattern, observed heterozygosity did not vary with population size, and we suggest that selection against inbred individuals maintains observed heterozygosity in small populations. Consistent with this hypothesis, we found a trend of lower inbreeding coefficients in the maternal than progeny generation in all of the populations, and half of the populations exhibited significant excesses of adult heterozygosity. Moreover, genetic diversity was not related to population size and was similar across all populations examined. Our results suggest that the consequences of increased selfing for population fitness in S. angularis, a species that experiences significant inbreeding depression, will depend on the relative magnitude and consistency of inbreeding depression and the demographic cost of selection for outcrossed progeny in small populations.
Characterization and development of an inner ear type I fibrocyte cell culture

A method has been developed that allows successful maintenance of secondary cell cultures derived from explants of the cochlear lateral wall of young adult gerbils. The secondary cultures were characterized morphologically with light and transmission electron microscopy and immunocytochemically with protein markers specific to various lateral wall cell types. Structural studies revealed fusiform-shaped cells with a paucity of cytoplasm surrounding the nucleus and slender processes. The cells showed little evidence of intercellular contact even when confluent. The cultures were immunopositive for vimentin, carbonic anhydrase isozyme II, creatine kinase isozyme BB and smooth endoplasmic reticulum Ca-ATPase, but lacked reactivity for cytokeratins and Na,K-ATPase. The results indicate that the cultures are comprised of type I fibrocytes from the spiral ligament. These findings are the first to demonstrate that inner ear spiral ligament cells can be isolated and maintained in secondary culture while retaining many of their in vivo characteristics. Based upon their location and content of ion transport enzymes, type I fibrocytes are thought to be involved in the recycling of potassium from perilymph into the stria vascularis. The establishment of this cell line provides a means to analyze the role of spiral ligament fibrocytes in maintenance of inner ear homeostasis.
Components required for cytokinesis are important for bud site selection in yeast

Polarized cell division is a fundamental process that occurs in a variety of organisms; it is responsible for the proper positioning of daughter cells and the correct segregation of cytoplasmic components. The SPA2 gene of yeast encodes a nonessential protein that localizes to sites of cell growth and to the site of cytokinesis. spa2 mutants exhibit slightly altered budding patterns. In this report, a genetic screen was used to isolate a novel ochre allele of CDC10, cdc10-10; strains containing this mutation require the SPA2 gene for growth. CDC10 encodes a conserved potential GTP-binding protein that previously has been shown to localize to the bud neck and to be important for cytokinesis. The genetic interaction of cdc10-10 and spa2 suggests a role for SPA2 in cytokinesis. Most importantly, strains that contain a cdc10-10 mutation and those containing mutations affecting other putative neck filament proteins do not form buds at their normal proximal location. The finding that a component involved in cytokinesis is also important in bud site selection provides strong evidence for the cytokinesis tag model; i.e., critical components at the site of cytokinesis are involved in determining the next site of polarized growth and division.
Coordination Number Determinations of Gold Complexes by EXAFS Spectroscopy

Gold coordination number with sulfur and phosphorus ligands concerns us in an EXAFS study of metabolites containing gold. These form as products in drug therapy against rheumatoid arthritis. In a transferability test of amplitude and phase shift functions from the known, two-coordinate structure, [Au(PPh2CH3)2], to the known, four-coordinate structure, [Au(PPh2CH3)4], the calculated coordination is two rather than the expected four. Also the results of fitting EXAFS data from gold incorporated into metallothionein suggest a two-coordinate gold site whereas the zinc and cadmium atoms (which gold replaces) are thought to be four coordinate. In light of the difficulties in calculating gold coordination numbers, further tests of empirical curve fitting for several Au-S and Au-P type structures were carried out. Additionally, measurements of EXAFS spectra at −185°C were made to study the effect of reduced thermal motion on the calculated coordination numbers. The EXAFS analysis method in this study follows those developed by Hodgson and coworkers [1]. All experiments monitored the Au LIII X-ray absorption edge. Data were collected at the Stanford Synchrotron Radiation Laboratory.
A review of some recent work in magnetooptical recording

This paper will review recent progress in disk recording with GaAs laser transducers and magnetooptical media. Reading and writing experiments have been performed at frequencies up to 5 MHz with a cryogenic disk assembly using Fe-EuO as the storage media. Experiments have been done with other magnetooptical materials such as intermetallics for room temperature operation. The efficiency, polarization, and lifetime of batch fabricated GaAs lasers will be described.
Joint sensor localisation and target tracking in sensor networks

The authors propose a sequential quasi-Monte Carlo (SQMC)-based algorithm for joint estimation of sensor-node locations and target trajectory in a wireless sensor network. The sensor nodes are randomly deployed with no prior knowledge about their positions. A predictive entropy-based information utility is used to select the leader node at each stage, and all other nodes are kept in standby mode to save power. The Bayesian estimates required to track the systems's non-linear dynamics are computed using the powerful SQMC method, which naturally integrates sensor collaboration with optimal leader node selection. Extensions of the algorithm to other interesting scenarios such as missing observations and non-Gaussian noise are also presented, which are very relevant to the unreliable environments encountered in hostile territories. The authors demonstrate through simulations that even with a very small fraction of the total number of nodes acting as beacon nodes, the proposed method can not only track the moving target, but can also obtain fairly accurate estimates of the (unknown) locatp(z(t)|z(i(j))(t − 1))ions of the sensor nodes.
Highly Sensitive Real-Time In Vivo Imaging of an Influenza Reporter Virus Reveals Dynamics of Replication and Spread

The continual public health threat posed by the emergence of novel influenza viruses necessitates the ability to rapidly monitor infection and spread in experimental systems. To analyze real-time infection dynamics, we have created a replication-competent influenza reporter virus suitable for in vivo imaging. The reporter virus encodes the small and bright NanoLuc luciferase whose activity serves as an extremely sensitive readout of viral infection. This virus stably maintains the reporter construct and replicates in culture and in mice with near-native properties. Bioluminescent imaging of the reporter virus permits serial observations of viral load and dissemination in infected animals, even following clearance of a sublethal challenge. We further show that the reporter virus recapitulates known restrictions due to host range and antiviral treatment, suggesting that this technology can be applied to studying emerging influenza viruses and the impact of antiviral interventions on infections in vivo. These results describe a generalizable method to quickly determine the replication and pathogenicity potential of diverse influenza strains in animals.
Dynamic chemical characterization of montane clouds

Abstract Cloud water collections have been made on Mt. Mitchell using a nearly real-time cloud and rain acidity/conductivity (CRAC) analyzer. Results are reported for integrating times of approximately 5 min during several cloud events in the summer and fall of 1987. Both pH and ionic strength during cloud events were found to be much more variable than previously indicated by cloud collection. Maximum values of H + and SO 4 2− ion concentrations in 5-min samples were as much as 2.5 times greater than those measured in 1-h integrated collections. These results are not influenced by instrumental variability to any measurable extent. Results from repeated quality control samples were highly reproducible, and agreement between integrated collection data and the average values of 5-min sequential samples was also very good.