cssi/SciSciGPT-SciSciNet huggingface dataset:
A hidden Markov model approach for prediction of genomic alterations from gene expression profiling

The mRNA transcript changes detected by Gene Expression Profiling(GEP) have been found to be correlated with corresponding DNA copy numbervariations detected by Comparative Genomic Hybridization (CGH). This correlation,together with the availability of genome-wide, high-density GEP arrays,supports that it is possible to predict genomic alterations from GEP data in tumors.In this paper, we proposed a hidden Markov model-based CGH predictor,HMM_CGH, which was trained in the light of the paired experimental GEP andCGH data on a sufficient number of cases, and then applied to new cases for theprediction of chromosomal gains and losses from their GEP data. TheHMM_CGH predictor, taking advantage of the rich GEP data already availableto derive genomic alterations, could enhance the detection of genetic abnormalitiesin tumors. The results from the analysis of lymphoid malignancies validatedthe model with 80% sensitivity, 90% specificity and 90% accuracy in predictingboth gains and losses.
Basin-scale patterns in the abundance of SAR11 subclades, marine Actinobacteria (OM1), members of the Roseobacter clade and OCS116 in the South Atlantic.

Summary Bacterioplankton are major biogeochemical agents responsible for mediating the flux of dissolved organic matter (DOM) and subsequent cycling of nutrients in the oceans. Most information about the composition of bacterioplankton communities has come from studies along well-defined biogeochemical gradients in the northern hemisphere. This study extends observations of spatial and temporal dynamics for SAR11, Actinobacteria and OCS116 in the North Atlantic by demonstrating distinct spatial variability in the abundance and distribution of these and other lineages across the South Atlantic gyre and in the Benguela upwelling system. We identified shifts in SAR11, Actinobacteria, OCS116, SAR86, SAR116 and members of the Roseobacter clade along basin-scale gradients in nutrients, chlorophyll and dissolved organic carbon (DOC). Distinct SAR11 subclades dominated the western and eastern regions of the gyre, and Actinobacteria, OCS116 and members of the Roseobacter lineages were most abundant at the deep chlorophyll maxima. SAR86 and SAR116 accounted for a significant fraction of coastal and open ocean communities, respectively, and members of the gamma sulfur oxidizer (GSO) clade persisted in the Benguela upwelling system. These data suggest that distinct communities are partitioned along basin-scale biogeochemical gradients, that SAR11 community structure varies across the gyre and that Actinobacteria, OCS116, and members of the Roseobacter clade are closely associated with phytoplankton in the gyre.
Analyzing Dynamic Pendulum Motion in an Interactive Online Environment Using Flash

A pendulum ‘engine’ with dynamic parameters can be created and pendulum functions manipulated and analyzed using interactive elements in Flash. The effects of changing the damping (convergence) properties, initial release angle and initial velocity conditions can be explored. The motions then can be digitized using the Flash Digitizer 1.1, exported and graphed. The powerful properties of actionscripting, coupled with the flexible interactivity of the Flash environment, allows for attractive and mathematically driven Flash movies. Along with the accessibility and interactive nature of the Web, and by contextualizing the history and mathematical applications of pendulum motions, this lesson becomes teacher and student-friendly for physics and mathematics classrooms.
A mannose family phosphotransferase system permease and associated enzymes are required for utilization of fructoselysine and glucoselysine in Salmonella enterica serovar Typhimurium

ABSTRACT Salmonella enteric serovar Typhimurium, a major cause of food-borne illness, is capable of using a variety of carbon and nitrogen sources. Fructoselysine and glucoselysine are Maillard reaction products formed by the reaction of glucose or fructose, respectively, with the e-amine group of lysine. We report here that S . Typhimurium utilizes fructoselysine and glucoselysine as carbon and nitrogen sources via a mannose family phosphotransferase (PTS) encoded by gfrABCD (glucoselysine/fructoselysine PTS components EIIA, EIIB, EIIC, and EIID; locus numbers STM14_5449 to STM14_5454 in S . Typhimurium 14028s). Genes coding for two predicted deglycases within the gfr operon, gfrE and gfrF , were required for growth with glucoselysine and fructoselysine, respectively. GfrF demonstrated fructoselysine-6-phosphate deglycase activity in a coupled enzyme assay. The biochemical and genetic analyses were consistent with a pathway in which fructoselysine and glucoselysine are phosphorylated at the C-6 position of the sugar by the GfrABCD PTS as they are transported across the membrane. The resulting fructoselysine-6-phosphate and glucoselysine-6-phosphate subsequently are cleaved by GfrF and GfrE to form lysine and glucose-6-phosphate or fructose-6-phosphate. Interestingly, although S . Typhimurium can use lysine derived from fructoselysine or glucoselysine as a sole nitrogen source, it cannot use exogenous lysine as a nitrogen source to support growth. Expression of gfrABCDEF was dependent on the alternative sigma factor RpoN (σ 54 ) and an RpoN-dependent LevR-like activator, which we designated GfrR. IMPORTANCE Salmonella physiology has been studied intensively, but there is much we do not know regarding the repertoire of nutrients these bacteria are able to use for growth. This study shows that a previously uncharacterized PTS and associated enzymes function together to transport and catabolize fructoselysine and glucoselysine. Knowledge of the range of nutrients that Salmonella utilizes is important, as it could lead to the development of new strategies for reducing the load of Salmonella in food animals, thereby mitigating its entry into the human food supply.
Terminal cretaceous extinction scenario for a catastrophe.

All the biotic changes that occurred at the end of Cretaceous time, including the extinction of the dinosaurs, may be the result of a single terrestrial catastrophe. The Arctic spillover model, first proposed to explain the marine extinctions, would have caused a rapid and intense change in the earth9s climate including a lowering of temperature and of precipitation. This change in climate may have triggered a series of ecological disasters that included the radical change in the distribution of vegetation on the earth as well as the extinction of the dinosaurs.
The averaged Bernoulli equation and macroscopic equations of motion for the potential flow of a two-phase dispersion

Abstract A description of a uniform two-phase dispersion in a potential flow is developed in terms of a macroscopic (averaged) potential and the average velocity of each phase. Using analogues to electromagnetic theory, the constitutive laws are expressed in terms of either an effective conductivity of the matrix or its polarization (average dipole moment). Bernoulli's equation for the fluid is expressed in averaged form. The results are applied to three example problems. The equations of motion for the “two-fluid model” are derived using the hypothesis that the averaged Bernoulli equation is differentiable. The continuous phase is incompressible but the dispersed phase may be compressible. The results are compatible with Geurst's equations which were derived using variational methods.
Attempts at prevention or treatment of intracranial arterial spasm: an update.

Numerous approaches to the prevention and treatment of intracranial arterial spasm have been made during the past three decades. In the present article, the author has assembled data about such attempts that were not included in a similar compilation published in 1980. Since 1980, there has been som
U.S.‐Mexico Economic Integration: Labor Relations and the Organization of Work in California and Baja California Agriculture*

Through a case study of tomato production in Baja California and California, this paper examines the impact of U.S.-Mexico economic integration on the organization of work and on wage trends and labor costs. In contrast to most previous scholarship, which is based on aggregate economic modeling, this paper provides an institutional approach to the study of NAFTA and longer-term U.S.- Mexico economic integration. I explore the impact of cross-border links in capital, product, and especially labor markets on labor costs, worker income, regional com- petitiveness, and the location of production. The paper demonstrates that in response to differing economic conditions and institutions in California and north- west Mexico, employers choose different labor management strategies, even though they use similar production technologies. In California, growers extract much higher productivity from workers by paying piece rates and are able to exter- nalize the costs of recruiting, transporting, housing, and retaining their seasonal labor force. As a consequence, the binational differential in wages is much greater than the differential in per unit labor costs, Baja's competitiveness is constrained by low productivity, and downward convergence in workers' net income is occurring.
Incidence of Agrobacterium tumefaciens Biovar 1 in and on 'Paradox' (Juglans hindsii × Juglans regia) Walnut Seed Collected from Commercial Nurseries.

Abstract The walnut rootstock ‘Paradox’ (Juglans hindsii × J. regia) is susceptible to Agrobacterium tumefaciens, which often results in a high incidence of crown gall in nursery or walnut production orchards. Though A. tumefaciens is susceptible to the commonly used preplant soil fumigants, crown gall incidence can rise above acceptable levels. We examined the ability of Paradox seed to acquire A. tumefaciens as a function of harvest method used prior to planting. Over a 2-year period at two participating commercial nurseries, Paradox seed were collected directly from the mother tree without contacting the soil or gathered after sitting on the orchard floor for up to 28 days. A. tumefaciens was never detected in or on the 2,650 seeds collected directly from the mother tree. Both virulent and avirulent A. tumefaciens strains were detected in and on the husk of nuts incubated on the orchard floor at a frequency directly proportional to the time spent on the orchard floor. Regardless of A. tumefaciens conta...
Pharmacotherapy for Heart Failure with Left Ventricular Dysfunction: Beyond Angiotensin‐Converting Enzyme Inhibitors and β‐Blockers

Angiotensin-converting enzyme (ACE) inhibitors and beta-blockers make up the cornerstone of therapy for patients with heart failure involving left ventricular dysfunction. These drug classes have been proven to decrease morbidity and mortality in patients with heart failure. Unfortunately, many patients remain symptomatic and experience disease progression despite taking both an ACE inhibitor and a beta-blocker. Others may be unable to tolerate one or both of these agents. In recent years, several other drug classes have been shown to provide additional morbidity and mortality benefits in patients with heart failure. These include angiotensin II receptor blockers (ARBs), aldosterone antagonists, and the combination of isosorbide dinitrate plus hydralazine. To select the most appropriate drug therapy for patients with heart failure, clinicians should consider results from clinical trials in specific patient populations, adverse-event profiles, tolerability, cost, and dosing regimens.
A Small Misconception

Regarding “Carbon sink: A clue from Biosphere 2?” (R. L. Walford, Science 's Compass, 15 Jan. p. [330][1]), I want to clear up a small misconception that has been widely repeated in the press (and also in the Perspective by J. E. Cohen and D. Tilman, 15 Nov. 1996, p. [1150][2]), namely that “carbon dioxide [CO2] was combining with the cement of the structure, carrying oxygen along with it to form calcium carbonate… hence the fall in oxygen concentration.” The cement in Biosphere 2 did not cause the oxygen loss. It is true that the CO2 reacted with the cement and that CO2 contains oxygen atoms. But it is molecular oxygen (O2) rather than oxygen atoms that was being lost from the air in Biosphere 2. The amount of oxygen atoms present in the water in Biosphere 2 is about 200 times more than the amount of oxygen atoms present as O2, so the loss of oxygen atoms to the cement was insignificant. Rather, what caused the O2 loss was the excess of organic matter in the soil, which supported an imbalance of O2-consuming respiration over O2-producing photosynthesis. The reaction of CO2 with the cement only made it a little harder for us to find the true cause of O2 loss, by scrubbing from the air the telltale product of respiration, CO2. Walford correctly points out that concrete absorbs CO2, but he does not point out that the Ca(OH)2 responsible for this uptake was obtained by driving CO2 off of limestone. Because some of the CaO2 becomes silicate-bound and some remains unreacted, concrete manufacture is a net source rather than a net sink for CO2. Further, the contribution of concrete manufacture to global CO2 production is only about 0.2 gigaton of carbon (GiC), compared with 6.5 or so GiC produced by fossil fuel burning and to a continental sink of about 1.7 GiC (S. Fan et al. , Reports, 16 Oct. p. [442][3]). Hence, even if limestone were slaked at one region and the concrete were used in another, the impact on the distribution of CO2 in the global atmosphere would be negligible. [1]: /lookup/doi/10.1126/science.283.5400.327g [2]: /lookup/doi/10.1126/science.283.5405.1150 [3]: /lookup/doi/10.1126/science.282.5388.442
Numerical simulation of unsteady fluid flow and propagation of a circular hydraulic fracture

A computational procedure is developed for solving the problem of a circular hydraulic fracture propagating under the action of frac-0fluid being pumped in at a central wellbore. The crack is modelled as continuous distributions of ring dislocations and the resulting elasticity singular integral equation is solved numerically. The fluid flow equations are approximated by local and global interpolation finite difference schemes. The coupling between elasticity and fluid flow is handled numerically, by, two different algorithms: one iterates on crack tip velocity whereas the other varies the time step size until it agrees with the chosen increment in crack length. Sample results are given; it is found that the velocity algorithm is computationally more, efficient and more stable. The model allows detailed tracing of pressure distribution and fluid flow in the fracture, even under complex conditions of cyclic injection and fluid rheology. It may serve as a stand-alone model of (horizontal) hydrafracs–especially at shallow depths–or it may be used as a reference frame to test the various numerical formulation/algorithms required for the ongoing development of a fully 3-D hydrafrac simulator.
Movies of filaments and plasma

Using a streak camera, and combining over 1,000 synchronized frames, 4D (2 D space, time in ps and wavelength) movies of the light and plasma emission in the wake of filaments are produced.
The Role of Nursing in the Management of Unintended Pregnancy

This article explores the role of nurses in the prevention, management, and treatment of unintended pregnancy. All nurses have a responsibility to understand the importance of reproductive health care in the primary care of women and their families, and to be prepared to respond to patients' needs for the prevention and management of unintended pregnancy. A public health framework provides an opportunity to identify the role of the nurse in primary, secondary, and tertiary prevention strategies that can contribute to the management of unintended pregnancy for the health of women and their families. Nursing education and the role of nurses in advocacy for reproductive health concerns are also addressed.
Enzymatic resolution of a key stereochemical intermediate for the synthesis of (−)-taxol

Abstract The taxol intermediate, racemic 3, was subjected to two consecutive kinetic resolutions with recombinant Candida antarctica lipase B in isopropenyl acetate/hexane. The absolute stereochemistry of the resulting acetate (+)-5 of > 99% enantiopurity, was assigned based on NMR and CD methods.
Spacecraft Formation Orbit Estimation Using WLPS-Based Localization

This paper studies the implementation of a novel wireless local positioning system (WLPS) for spacecraft formation flying to maintain high-performance spacecraft relative and absolute position estimation. A WLPS equipped with antenna arrays allows each spacecraft to measure the relative range and coordinate angle(s) of other spacecraft located in its coverage area. The dynamic base station and the transponder of WLPS enable spacecraft to localize each other in the formation. Because the signal travels roundtrip in WLPS, and due to the high spacecraft velocities, the signal transmission time delay reduces the localization performance. This work studies spacecraft formation positions estimation performance assuming that only WLPS is available onboard. The feasibility of estimating the spacecraft absolute position using only one-dimensional antenna array is also investigated. The effect of including GPS measurements in addition to WLPS is studied and compared to a GPS standalone system.
Cerebrospinal Fluid Phospholipid Changes Following Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality, with approximately 1.4 million people suffering a TBI each year. With TBI, a cascade of events is initiated including the activation of phospholipases, which leads to the disruption of the lipid bilayer of the membrane of neurons and neuroglia. The purpose of this study is to describe phospholipid changes following TBI. A total of 39 cerebrospinal fluid samples were obtained from the ventricular catheter system of 10 participants who received a TBI as a result of a motor vehicle crash, being struck by a vehicle as a pedestrian, or a fall. Phospholipids were extracted from samples and measured by normal-phase high-performance liquid chromatography with ultraviolet detector at a wavelength of 206 nm. The highest mean concentration of lysophosphatidylcholine occurred on Day 1 after injury. The concentration of phosphatidylserine was variable, with the highest mean concentration occurring on Day 2 after injury. The highest mean concentrations of phosphatidylethanolamine, phosphatidylcholine, and sphingomyelin occurred on Day 4 after injury. Findings provide preliminary evidence for disruption of central nervous system membrane phospholipids following TBI.
Contribution of the reaction pathways involved in the isomerization of monosaccharides by alkali

Abstract The isomerization of eight hexoses and four pentoses, in aqueous KOH at pH 11.5 under nitrogen, was monitored by l.c. on cation (Pb 2+ )-exchange and reverse-phase columns. The primary epimerization reaction of pentoses and hexoses accounts for ∼90% of the saccharides found in solution after one week. The remaining saccharides were formed in part by fragmentation and recombination. This is indicated by the formation of hexoses (glucose and sorbose) during the isomerization of pentoses, and by the simultaneous formation of 3- and 4-epimeric hexuloses from hexoses. The aldol reaction responsible for the formation of hexoses (glucose, fructose, and sorbose) from glyceraldehyde at pH 11.5 was found to be fast ( t 1/2 = 2 h), which accounts for the rapid fragmentation and recombination observed.
Teletherapy beam characteristics: The first second

The beam characteristics of radiotherapytreatment units are measured and recorded under circumstances in which transient effects are eliminated. Output measurements are done by averaging several readings. Isodose curves are obtained during a period of irradiation which is large compared with that used in patient treatment. When treatments are given, the therapy unit is assumed to deliver radiation beams that match the data acquired during calibration. We have looked at the energy, field uniformity, and output constancy typical of a number of these machines in their initial stages of operation. Although most can provide their ‘‘reference’’ beam characteristics in a short time, there are exceptions. The implications for patient treatment, port filming, and film dosimetry are discussed.
Synthesis and biological evaluation of thiazolidine-2,4-dione and 2,4-thione derivatives as inhibitors of translation initiation

Abstract In an effort to generate novel translation initiation inhibitors for cancer therapy, a series of 2′-benzyloxy-5′-substituted-5-benzylidene-thiazolidine-2,4-thione and dione derivatives was synthesized and evaluated for activity in translation initiation specific assays. Several candidates of the 5-benzylidene-thiazolidine-2,4-diones (3c, 3d, and 3f) and -thiones (2b, 2e, and 2j), inhibit cell growth with low μM GI50 mediated by inhibition of translation initiation, which involves partial depletion of intracellular Ca2+ stores and strong phosphorylation of eIF2α.
The performance of organic and conventional cropping systems in an extreme climate year

The 1999 severe crop season drought in the northeastern US was followed by hurricane-driven torrential rains in September, offering a unique opportunity to observe how managed and natural systems respond to climate-related stress. The Rodale Institute Farming Systems Trial has been operating since 1981 and consists of three replicated cropping systems, one organic manure based (MNR), one organic legume based (LEG) and a conventional system (CNV). The MNR system consists of a 5-year maize–soybean–wheat–clover/hay rotation, the LEG of a 3-year maize–soybean–wheat–green manure, and the CNV of a 5-year maize-soybean rotation. Subsoil lysimeters allowed quantification of percolated water in each system. Average maize and soybean yields were similar in all three systems over the post-transition years (1985–1998). Five drought years occurred between 1984 and 1998 and in four of them the organic maize outyielded the CNV by significant margins. In 1999 all crop systems suffered severe yield depressions; however, there were substantial yield differences between systems. Organic maize yielded 38% and 137% relative to CNV in the LEG and MNR treatments, respectively, and 196% and 152% relative to CNV in the soybean plots. The primary mechanism of the higher yield of the MNR and LEG is proposed to be the higher water-holding capacity of the soils in those treatments, while the lower yield of the LEG maize was due to weed competition in that particular year and treatment. Soils in the organic plots captured more water and retained more of it in the crop root zone than in the CNV treatment. Water capture in the organic plots was approximately 100% higher than in CNV plots during September's torrential rains.
The purity of aflatoxin G1 and use of antioxidant and chelating agent on the purification of the toxin by thin-layer chromatography.

Abstract During purification of aflatoxin G 1 by TLC procedures, about ten additional modified toxins are separated as fluorescent bands. G 2 produces only one or two modified toxin bands under similar conditions. Use of BHT in developing and eluting solvents and EDTA in preparation of TLC plates and operation of the entire procedure in a dark room effectively prevent such undesirable changes of the toxin. Crude G 1 is usually yellow in visible light and emits a green fluorescence by ultraviolet irradiation. Upon further purifications it becomes colorless in visible light and a light blue fluorescent compound under ultraviolet light. During purification, the ratio of absorbance at 360 mμ or 366 mμ to that at 264 mμ changes from about 2 to 0.5. The high absorbance in the region of 360 mμ for the crude toxin is apparently due to an unknown yellow impurity. A similar change of the ratio is also observed during purification of G 2 .
Gravitational instability and shear stabilization in a dusty plasma layer

We examine the behavior of a diffuse layer of metallic dust particles under the combined influence of gravity and magnetic fields. Such a configuration has recently been proposed as a means of promoting passive removal of orbital space debris by artificially enhancing the drag on the debris, thereby decelerating it and hastening its reentry into the thermosphere. We assume that the metallic dust particles become charged in the earth's ionosphere so that the particles in the layer can be treated collectively as a plasma continuum. Using two- and three-dimensional magnetohydrodynamic simulations, we consider the long-time nonlinear evolution of several such ideal dusty plasma layers. Simulations confirm that the well-known Rayleigh-Taylor instability that arises when a heavy fluid is placed on top of a lighter fluid is present in these systems. We show that a quiescent, uniform layer is unstable to very small perturbations and rapidly breaks up. Layer breakup is complete within 15 minutes after particle deposition, which is much too short a time to provide any meaningful reduction in debris velocity. We consider a possible method for stabilizing the layer by imposing a tailored shear flow, a technique that has shown promise for stabilizing plasmas in magnetic fusion applications. We discuss the long-time evolution of dusty plasma layers subjected to this shearing motion and show how layer stability is affected for a range of flow conditions. We also highlight other practical aspects of layer initialization, orientation, and morphology and discuss how these properties impact layer stability. The results of the full nonlinear numerical simulations are compared to results obtained using a linear theory.
A hydrodynamic model for bubble—particle attachment

Abstract The process of bubble—particle attachment has been modeled by simulating the trajectory of a small particle as it approaches a bubble. The particle trajectory has been determined using a dynamic force balance between the force pressing the particle against the bubble and the force resisting the viscous film thinning. From the simulated trajectories, the closest approach distance between the particle and the bubble has been determined. The model assumes that bubble—particle adhesion occurs when the approach distance becomes smaller than the critical thickness at which the disjoining liquid film ruptures spontaneously. The model predictions have been verified experimentally using different sizes of bubbles and particles.
Method of controlling wafer surface polarity to reduce spacer particle contamination

In general process, there is a polymer removal step by CR-SPM (Caros' acid clean) or STD clean (Standard Clean) after spacer etching. Sometimes the particles are found by KLA scan right after CR/STD clean, but not found after spacer etching. After studying the characteristics of particles, the formation of particles is due to the polarity of OD area (active area) surface changed from hydrophilic to hydrophobic and hydrophobic particles that contained in CR/STD tank are attached on OD area surface. In this report, a whole new in-situ polarity modification concept that changing hydrophobic Si surface to hydrophilic SiO surface by adding a very short O2 plasma treatment right after spacer etch is presented. The concept is evaluated in bare silicon and TEOS control wafers, and the results reveal that O2 plasma treatment can avoid particle attachment not only effectively but also efficiently. By the experiment, in-situ five seconds' O2 plasma is implanted in spacer etching recipe and two products are split to test. The WAT (Wafer Acceptance Test) and yield of split are comparable with standard condition.
Pathology in essential tremor

The pathology of essential tremor (ET) is increasingly being studied. The main findings include a reduction in cerebellar Purkinje cells, other pathological changes of cerebellar degeneration and restricted Lewy bodies in the locus ceruleus. This paper will review those findings and put them into context with clinical studies in ET and findings in neurodegenerative disorders such as Parkinson's disease.
A non-equilibrium cycle approach for optimization of successive nuclear fuel reloads in PWR's

Abstract A non-equilibrium cycle approach for PWR fuel management has been developed based on fuel cycle and plant operation experience. This approach is incorporated into a computer code. MISER. The methods employed give emphasis to the accuracy of physics modeling and realistic reactor operating constraints. The non-equilibrium approach provides a flexible and practical method of evaluating cost-optimal short- and long-term fuel policies in the current situation of changing fuel economics and reactor operating conditions. In particular, it is being applied to fuel cycle optimization for San Onofre Unit 1, and, in general has the capability of performing fuel management on larger commercial PWR's (see Lew, 1976; Lew and Fenech, 1976). For San Onofre Unit 1, a non-equilibrium policy was found to have a potential 4% lower levelized fuel cycle costs and a potential 15% lower initial capital costs than the current equilibrium fuel management policy. This represents a potential fuel cycle cost saving on the order of nearly a half million dollars and potential initial capital cost savings of a million dollars per yr. This minimum cost policy was found to be sensitive to the assumptions of fuel salvage value. For the policies and operating constraints considered, the minimum costs policy was found to be insensitive to the range of U 3 O 8 and enrichment costs considered. In addition, this policy was also found to be insensitive to variations in the adjustable physics power and burn-up parameters and to reductions in the maximum radial peaking factor constraint.
Time-Dependent Monte Carlo Deposition Rate from Flash X-Ray Sources

We present a scheme for obtaining a continuous and explicit time-dependent description of the transport of all generations of particles in the cascade produced by state-of-the-art coupled electron/photon Monte Carlo codes that employ a macroscopic random walk to describe electron trajectories. The model is applied to the prediction of the time-dependent energy deposition rate in air exposed to the flash x-ray environment generated by a high-intensity pulsed relativistic electron source with energies up to 10.0 MeV. Results obtained for an instantaneous pulse demonstrate the time dispersion, or transport broadening, of the deposition rate due to the scattered x rays. The magnitude of the delayed contribution from this scattered radiation is predicted for a source based on synchronized half-sine-wave voltage and current pulses. The spatially dependent time-integrated deposition is verified through comparison with the volume-averaged deposition predicted by a time-independent model.
Sub-picowatt resolution calorimetry with niobium nitride thin-film thermometer

High-resolution calorimetry has many important applications such as probing nanoscale thermal transport and studying the thermodynamics of biological and chemical systems. In this work, we demonstrated a calorimeter with an unprecedentedly high resolution at room temperature using a high-performance resistive thermometry material, niobium nitride (NbNx). Based on a theoretical analysis, we first showed that the heat flux resolution of a resistive-thermometry based calorimeter depends on the parasitic thermal conductance of the device and the temperature coefficient of resistance (TCR) of the thermometer, when the noise is limited by the Johnson noise. Based on this analysis, we then developed a calorimeter using NbNx as the thermometry material because it possesses both high TCR (∼0.67%/K) and a low thermal conductivity (k ∼ 1.1 W/m K). This calorimeter, when used with the modulated heating scheme, demonstrated an unprecedentedly high power resolution of 0.26 pW at room temperature. In addition, NbNx based resistive thermometry can also be extended to cryogenic temperature, where the TCR is shown to be significantly higher.
Lipidomic analysis of N-acylphosphatidylethanolamine molecular species in Arabidopsis suggests feedback regulation by N-acylethanolamines.

N-Acylphosphatidylethanolamine (NAPE) and its hydrolysis product, N-acylethanolamine (NAE), are minor but ubiquitous lipids in multicellular eukaryotes. Various physiological processes are severely affected by altering the expression of fatty acid amide hydrolase (FAAH), an NAE-hydrolyzing enzyme. To determine the effect of altered FAAH activity on NAPE molecular species composition, NAE metabolism, and general membrane lipid metabolism, quantitative profiles of NAPEs, NAEs, galactolipids, and major and minor phospholipids for FAAH mutants of Arabidopsis were determined. The NAPE molecular species content was dramatically affected by reduced FAAH activity and elevated NAE content in faah knockouts, increasing by as much as 36-fold, far more than the NAE content, suggesting negative feedback regulation of phospholipase D-mediated NAPE hydrolysis by NAE. The N-acyl composition of NAPE remained similar to that of NAE, suggesting that the NAPE precursor pool largely determines NAE composition. Exogenous NAE 12:0 treatment elevated endogenous polyunsaturated NAE and NAPE levels in seedlings; NAE levels were increased more in faah knockouts than in wild-type or FAAH overexpressors. Treated seedlings with elevated NAE and NAPE levels showed impaired growth and reduced galactolipid synthesis by the “prokaryotic” (i.e., plastidic), but not the “eukaryotic” (i.e., extraplastidic), pathway. Overall, our data provide new insights into the regulation of NAPE–NAE metabolism and coordination of membrane lipid metabolism and seedling development.
Limitations in the Synthesis of High Molecular Weight Polymers via Nitroxide-Mediated Controlled Radical Polymerization: Experimental Studies

Limitations associated with preparing high molecular weight polystyrene (PS) by nitroxide-mediated controlled radical polymerization have been tested by considering the role of unimolecular initiator concentration on active polymer radical concentration and thus degree of polymerization. Recent theories ignoring autopolymerization effects lead to the conclusion that, at low monomer conversion, the number-average molecular weight, Mn, scales with the −2/3 power of unimolecular initiator concentration. Bulk polymerizations were done using either α-methylstyryl di-tert-butyl nitroxide (A−T) as unimolecular initiator or PS macroinitiator made from A−T. These initiators allow relatively low reaction temperature (77, 87, or 97 °C) and moderate, but not eliminate, the contribution of autopolymerization or thermal initiation of polymerization. By varying unimolecular initiator concentration over nearly 4 orders of magnitude, well-controlled PS, with polydispersity index ≤ 1.4, can be made with Mn values in the ra...
Experimental Kwashiorkor and Marasmus

DURING the past two decades, there has been a growing scientific interest in the diseases kwashiorkor and marasmus. Their study could add considerably to our understanding of the regulation of metabolic processes in mammals and of the interrelation of nutrition to mental development and infection. Progress in these studies has so far been greatly handicapped by the failure, in spite of numerous attempts, to produce these conditions completely in experimental animals.
Weekly telephone contact does not enhance the compliance of home apnea monitoring.

Objective To evaluate the effect of weekly telephone contact with families in enhancing the use of home apnea monitors. Study design This was a prospective, randomized, single-blinded study of 65 infants who were prescribed home apnea monitoring at the time of initial discharge from the hospital. Exclusion criteria included participation in any other study involving home monitoring or nonavailability of home telephone. Infants were randomized either to the "standard" or "telephone" group by a stratified balanced block technique. All families were instructed to use the monitor during the first 4-week period at all times except during bathing and during the second 4-week period at all unattended times and at night. The families in the telephone group were contacted weekly for 8 weeks. The telephone interview reviewed the events of the previous week but did not include specific encouragement to use the monitor. Both groups received routine pediatric care and follow-up at our high-risk premature clinic. The primary outcome measure was compliance measured as the percentage of time as well as the hours per day that the infant spent on the monitor as recorded by the documented monitor. Results The telephone (n = 30) and standard (n = 32) groups were similar (p > 0.10) with respect to birth weight (1567 +/- 778 versus 1710 +/- 777 gm), gestational age (30.9 +/- 4.2 versus 31.1 +/- 4.6 weeks), maternal age (24.9 +/- 6.0 versus 25.3 +/- 5.4 years), and commercial insurance (46.7% versus 46.9%), a marker of higher socioeconomic status. Compliance of the telephone versus the standard group was similar during the first 4-week period (74.7 +/- 24.9 versus 75 +/- 27.8%, p = 0.85) (17.9 +/- 5.9 versus 18.2 +/- 6.6 hours/day), the second 4 week period (63.4 +/- 29.1 versus 58.9 +/- 30.9%, p = 0.59) (15.2 +/- 7.0 versus 14.1 +/- 7.4 hours/day) and the entire 8-week period (69.3 +/- 24.7 versus 67.7 +/- 26.2%, p = 0.82, Mann-Whitney U-test) (16.7 +/- 6.0 versus 16.1 +/- 6.5 hours/day), respectively. An abnormal pneumocardiogram at the time of discharge was the only identified factor that improved the compliance for the entire 8-week period (73.1 +/- 22 versus 52.1 +/- 28.5%, p = 0.02) (17.5 +/- 5.2 versus 12.5 +/- 6.8 hours/day) and the first 4-week period of monitoring (81.7 +/- 22.9 versus 59.5 +/- 31.3%, p = 0.01) (19.6 +/- 5.5 versus 14.2 +/- 7.5 hours/day). Conclusion Weekly telephone contact, without specific encouragement to use the monitor, did not improve compliance. Compliance was greater in subjects who had abnormal pneumocardiogram results at the time of discharge from hospital regardless of their telephone/standard group assignment. We speculate that in this already compliant population, more targeted advice is necessary to increase compliance.
Design and simulation of PZT-based MEMS piezoelectric sensors

Devices with increased sensitivities are needed for various applications including the detection of chemical and biological agents. This paper presents the design of microelectromechanical systems (MEMS) devices that incorporate lead zirconate titanate (PZT) films in order to realize highly sensitive sensors. In this work, the piezoelectric properties of the PZT are exploited to produce sensors that perform optimally for mass sensing applications. The sensor is designed to operate as a thin-film bulk acoustic resonator (TFBAR) whereas a piezoelectric is sandwiched between electrodes and senses a change in mass by measuring a change in resonance frequency. Modeling of the TFBAR sensor, using finite element analysis software COMSOL, was performed to examine optimal device design parameters and is presented in this paper. The effect of the PZT thickness on device resonance is also presented. The piezoelectric properties of the PZT is based on its crystal structure, therefore, optimization of the PZT film growth parameters is also described in this work. A detailed description of the fabrication process flow developed based on the optimization of the device design and film growth is also given. The TFBAR sensor consists of 150 nm of PZT, 150nm of silicon dioxide, silicon substrate, titanium/platinum bottom electrodes, and aluminum top electrodes. The top electrodes are segmented to increase the sensitivity of the sensor. The resonance frequency of the device is 3.2 GHz.
Observations on electric railway practise

The development of rail transportation since the day of stage-coaches and horsedrawn tram cars, has been a process of evolution in which some reminders of the past are still noticeable.
Solid-phase clean-up and thin-layer chromatographic detection of veterinary aminoglycosides

Chemical methods are needed to confirm the presence of antibiotics detected by microbial inhibition assays in fluids and tissues of farm animals. We have optimized the conditions for the isolation of hygromycin B with a copolymeric bonded solid-phase silica column followed by thin-layer chromatography (TLC) separation and detection of its fluorescence derivative after reaction with fluorescamine. The detection limit of the drug was 50 ng. Serum and plasma samples fortified with hygromycin B were acidified and passed through the copolymerized solid-phase columns previously conditioned with phosphate buffer. Hygromycin B was trapped in the columns and eluted with diethylamine-methanol and analyzed by TLC using acetone-ethanol-ammonium hydroxide as the developing solvent. Hygromycin B bands were derivatized at acidic pH with fluorescamine and visualized under ultraviolet light. Hygromycin B added to bovine plasma was detectable at 25, 50, 100, 250 and 500 ng/ml (ppb). Hygromycin B added to swine serum was detected at 50 ng/ml. However, the serum had to be deproteinized with trichloroacetic acid or acetonitrile prior to solid-phase extraction to gain accurate values. Neomycin and gentamicin (100 ng/ml aqueous solutions) could also be isolated with copolymeric solid-phase columns at a level of 50 ng. Gentamicin, neomycin, gentamicin, spectinomycin, hygromycin B and streptomycin could be separated by TLC, allowing multiresidue detection of these aminoglycosides. The respective RF values of 0.64, 0.56, 0.52, 0.33 and 0.20 indicate the separation of these five compounds. This procedure provides a rapid and sensitive method for the semi-quantitative estimation of aminoglycosides.
Reactions of chlorine with Si(100) and Si(111): adsorption and desorption kinetics

Abstract Adsorption of atomic and molecular chlorine on the Si(100) and Si(111) surfaces, and the desorption kinetics of the formed chlorosilicon species have been investigated. The saturation coverage after Cl2 exposure is 1.0 ± 0.1 ML on Si(100) and 1.4 ± 0.1 ML on Si(111), while in atomic chlorine exposure the uptake slows down considerably above ≈ 1.5 ML on both surfaces. The desorption kinetics of the major chlorosilicon products, SiCl2 and SiCl4, is first order in chlorine coverage under 850 K. Above 900 K the SiCl2 desorption kinetics is different on Si(111) and Si(100). Desorption of SiCl2 above 900 K from Si(111) is second order in chlorine coverage. From the Si(100) surface above 900 K the SiCl2 desorption rate is first order at 0.1 ML ν d = 2000 cm 2 s and E d = 83 kcal mol . When empty surface sites are available, desorption of SiCln ( n > 1 ) is accompanied by dissociation of some of the SiCln on the surface to form SiCl(ads).
Best bounds for expected financial payoffs I: algorithmic evaluation

A systematic approach to the evaluation of best bounds for expected financial payoffs, in case the mean, variance and range of the distribution are known, is presented. It is based on the majorant/minorant mathematical technique, which consists to bound a payoff by some quadratic polynomial. For the class of piecewise linear payoff functions, a classification of the global triatomic extrema is given, and a general algorithm for evaluation is formulated.
Differential ozone susceptibility of Centennial Russet and White Rose potato as demonstrated by fumigation and antioxidant treatments

Because quantitative field estimates of potato (Solarium tuberosum L.) yield losses attributable to ozone (O3) air pollution damage in California need to be assessed, the antioxidant compound N-[-2-(2-oxo-l-imidazolidiny l)ethyl]-N′-phenylurea (EDU or DPX-4891) was evaluated for suitability in estimating these yield losses and in differentiating O3-susceptible from O3-resistant cultivars.
Thermochemistry of the new silica polymorph moganite

Samples of microcrystalline silica varieties containing variable amounts of the new silica polymorph moganite (up to R~82 wt.%) have been studied by a combination of high temperature solution calorimetry using lead borate (2 PbO · B2O3) solvent and transposed temperature drop calorimetry near 977 K, in order to investigate the thermochemical stability of this new silica mineral. The enthalpy of solution at 977 K and the heat content (H977 — H298) of “pure” moganite phase were estimated to be -7.16 ± 0.35 kJ/mol and 43.62 ± 0.50 kJ/mol, respectively. The standard molar enthalpy of formation is-907.3 ± 1.2 kJ/mol. Thus, calorimetry strongly supports results of previous X-ray and Raman spectroscopic studies that moganite is a distinct silica polymorph. Its thermochemical instability relative to quartz at 298 K of 3.4 ± 0.7 kJ/mol is marginally higher than those of cristobalite and tridymite. Structurally, this instability may be related to the presence of distorted 4-membered rings of SiO4 tetrahedra, which are not found in the quartz structure. The metastability relative to quartz may also explain the apparent scarcity of moganite in altered rocks and in rocks that are older than 130 my.
Effect of variable stiffness colonoscopes on cecal intubation times for routine colonoscopy by an experienced examiner in sedated patients.

Background and Study Aims: Variable-stiffness colonoscopes allow passage of the rectosigmoid colon in a flexible mode, followed by stiffening to prevent looping. This feature might allow faster cecal intubation. Patients and Methods: Consecutive patients without previous colonic or rectal resection, inflammatory bowel disease, or anticipated need for either a pediatric or standard insertion tube were evaluated. Four Olympus colonoscopes, including a standard adult insertion-tube diameter variable-stiffness colonoscope (VSA), a pediatric variable-stiffness colonoscope (VSP), a standard adult colonoscope (CF-140) (SA), and a standard pediatric colonoscope (PCF-140) (SP) were used in rotation. Results: Among 358 consecutive patients, 99.2 % of exams were complete to the cecum. The stiffening device was activated in 61 % and 80 % of the adult and pediatric variable-stiffness examinations, respectively. The examiner judged the device to be very useful, somewhat useful, and of no help in 46%, 44%, and 10% of VSA colonoscope examinations and 55 %, 33 %, and 12 % of VSP colonoscope examinations. However, the mean cecal insertion time was 4.04 minutes, with no difference between the four colonoscopes (P=0.98). The percentage of intubations in 5 minutes 23.7 %, with no significant difference between the colonoscopes. Conclusions: Variable-stiffness colonoscopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times in sedated patients. Additional studies by other experienced and inexperienced examiners, as well as evaluation of additional technical improvements and evaluation in unsedated patients, are needed.
A cobalt-lysine study of primary olfactory projections in king salmon fry (Oncorhynchus tshawytscha Walbaum)

Primary olfactory projections in king salmon fry, Oncorhynchus tshawytscha, were studied with the cobaltlysine technique and after sectioning the entire head in a frozen state. The labeled axons can be traced from the olfactory epithelium, where cobalt was applied, into the olfactory bulb and to the ventral and lateral regions of the ventral telencephalon. The latter projection has not previously been reported, and may in actuality represent a transneuronal transport of cobalt. The terminations in the glomerular layer and in the external cellular layer of the bulb appear to be distributed differently in different parts of the bulb, suggesting regional specializations. A few neurons in the bulb were also always labeled suggesting that they may project to the olfactory epithelium.