This journal article reports a study originally intended to examine the microbial composition of Octopus Spring and nearby vent biofilms. The article compares the lipid profiles of several genera within the Aquificales as well as measurements of the isotopic carbon fractionation associated with autotrophic and heterotrophic growth of Thermocrinis ruber. Results of the study have led to improved understanding of population structure in the Octopus Spring pink streamer community, a hyperthermophilic chemolithotrophic ecosystem in Yellowstone National Park.
The results of a time-resolved study of the avalanche and streamer formation phases leading to breakdown in atmospheric nitrogen and dry air. Results of experiments and two-dimensional simulations are presented. It is shown what processes are responsible for the formation of a streamer. The trends of externally measured quantities correspond with those predicted by our model. 3 figs., 5 refs.
In general, macroscopic material failure is a manifestation of irreversible changes at the microscopic level. Many tissues, which may appear to be macroscopically homogeneous, are, at a fundamental microscopic level, a composite material. For example, cornea is composed of a hyaluronic acid matrix in which layers of collagen fibers are overlaid in a crossing pattern. The points where the collagen fibers intersect are potential nucleation sites for microscopic defects, which under the action of tensile stress, nucleate, grow and coalesce to form macroscopic failure planes, or spall planes. Using a model based on microstructural evolution, this paper examines the failure process during photoablation. Specifically, the paper describes a physically motivated, micromechanical model based on the nucleation and growth of spherical voids. This model is then used to simulate photoablation of cornea. Potential ...
The ozone production process in a pulsed positive dielectric barrier discharge (DBD) is studied by measuring the spatial distribution of ozone density using a two-dimensional laser absorption method. DBD occurs in a 6 mm point-to-plane gap with a 1 mm-thick glass plate placed on the plane electrode. First, the propagation of DBD is observed using a short-gated ICCD camera. It is shown that DBD develops in three phases: primary streamer, secondary streamer and surface discharge phases. Next, the spatial distribution of ozone density is measured. It is shown that ozone is mostly produced in the secondary streamer and surface discharge, while only a small amount of ozone is produced in the primary streamer. The rate coefficient of the ozone production reaction, O + O_2 + M #-># O_3 + M, is estimated to be 2.5 x 10"-"3"4 cm"6 s"-"1.
This work deals with a time-resolved optical study of the avalanche and streamer formation phases leading to breakdown in atmospheric nitrogen. The authors present the results obtained for nitrogen, from experiments and two-dimensional model simulations. This model is used to obtain a better insight in the relevant mechanisms and processes by a comparison of measurements and simulation data. The trends of externally measured quantities correspond with those predicted by the model.
A total of 10 samples disks of 2024-T3 aluminum and 4130 ferrous steel were exposed to rocket-triggered lightning currents at the Kennedy Space Center test site in Florida during the summer of 1990. The experimental configuration was arranged so that the samples were not exposed to the preliminary streamer, wire-burn, or following currents that are associated with an upward-initiated rocket-triggered flash but which are a typical of naturally initiated lightning. Return-stroke currents and continuing currents actually attaching to the sample were measured, augmented by close-up video recordings of approximately 3 feet of the channel above the sample and by 16-mm movies with 5-ms resolution. From these data it was possible to correlate individual damage spots with streamer, return-stroke, and continuing currents that produced them. Substantial penetration of 80-mil aluminum was produced by a continuing current of submedian amplitude and ...
The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons...Full Text Available
The macroscopic behavior of magnetostrictive materials results from domain evolutions occurring at a microscopic scale. The author shows how to compute magnetization and magnetostriction curves by appraising the behavior of the underlying microstructures. The method hinges on an averaging device (Young measures), which allows one to pass from the microscopic to the macroscopic scale. He takes into account the kinematical constraints on the accommodation of elastic effects, and he highlights the role of material symmetry in the selection of energetically optimal microstructures.
In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NOx removal under suitable conditions is obtained in our experiments.
In the present study Balb/c mice were exposed to 3,4-benzopyrene, painted on the skin every 2nd day for a total of 6 months, and simultaneously irradiated with athermal (5 mW/cm/sup 2/) or subthermal (15 mW/cm/sup 2/) doses of 2,450 MHz microwaves. The other group of animals was preirradiated with microwaves at 10 mW/cm/sup 2/ power level for 1, 2, or 3 months and then treated with benzopyrene, as above. Control mice were exposed for 6 months to benzopyrene, resulting in the development of baso- or spinocellular skin carcinoma within approximately 9 months, and sham-irradiated with microwaves. The growth of the tumour was assessed according to a self-designed 7-range macroscopic scale, supported by microscopical examinations of skin sections. All protocols of microwave irradiations resulted in a significant acceleration of the development of benzopyrene-induced skin cancer and in shortening of life span of the tumour-bearing hosts. This effect ...
Secreted human bronchial mucins, directly collected from macroscopically healthy bronchial mucosa, were prepared in the presence of six proteinase inhibitors, and analysed by electron microscopy. These...Full Text Available
The macroscopic stress distribution across an annealed Zircaloy-4 gas tungsten arc weld was measured by neutron time-of-flight diffraction at the SMARTS diffractometer at Los Alamos National Laboratory. The stresses after annealing are about 40% lower than those in the same weld prior to heat treatment. The intergranular strains in the reference coupons, which give the macroscopic stress free lattice spacings, are consistent with the difference in cooling the strongly textured plate and the weakly textured weld.
Abstract Simon Saunders and David Wallace have proposed an attractive semantics for interpreting linguistic communities embedded in an Everettian multiverse. It provides a charitable interpretation of our ordinary talk about the future, and allows us to retain a principle of bivalence for propositions and to retain the law of excluded middle in the logic of propositions about the future. But difficulties arise when it comes to providing an appropriate account of the metaphysics of macroscopic objects and events. I evaluate various metaphysical frameworks which might be combined with the Saunders-Wallace semantics. I conclude that the most appropriate metaphysics to underwrite the semantics renders Everettian quantum mechanics a theory of non-overlapping worlds.
We examine the star clusters in the irregular galaxy NGC 4449. We use a near-infrared spectrum and broad-band images taken with the HST to place a limit of 8--15 Myrs on the age of the bright central ojbect in NGC 4449. Its luminosity and size suggest that it is comparable to young super star clusters. However, there is a peculiar nucleated-bar structure at the center of this star cluster, and we suggest that this structure is debris from the interaction that has produced the counter-rotating gas systems and extended gas streamers in the galaxy. From the images we identify 60 other candidate compact star clusters in NGC 4449. Fourteen of these could be background elliptical galaxies or old globular star clusters. Of the star clusters, three, in addition to the central object, are potentially super star clusters, and many others are comparable to the populous clusters found in the LMC. The star clusters span a large range in ages with no obvious peak in cluster ...
Production of ozone and OH radical is required to advance the plasma chemical reactions in the NOx removal processes for combustion gas treatment. The corona discharge to the water surface is expected to induce the good conditions for the proceeding of the NO oxidation and the NO_2 dissolution removal into water. In order to get the fundamental data of the corona discharge over the water surface, the positive and negative V-I characteristics and the ozone production were measured with the multi needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both the DC and the pulse corona to the water surface showed a stable and almost the same V-I characteristics as to plate electrodes though the surface of water was waved by corona wind. The positive streamer corona showed ...
The Alice experiment is one of the four main LHC (Large Hadron Collider) experiments. It is dedicated to the study of a new state of matter: the quark gluon plasma, where quarks and gluons are no longer confined within hadrons. In this document, the physics issues that led to the construction of Alice dimuon spectrometer, are described. Then, the research and development on the dimuon spectrometer is presented. The different absorbers are described and experimental tests used to determine their dimensions are presented. The dimuon trigger built using the RPC (Resistive Plate Chamber) streamer mode is then described along with the associated beam and cosmic tests and results. Finally, the tracking system is described in detail and more particularly all its electronics and the first station. The physics constraints on the expected performances of all these systems are clearly defined. (author)
Favorable reaction channels are searched for in order to obtain the superheavy element "2"9"8114. The interaction energy is supposed to comply with the adiabatic hypothesis. Concerning the deformation energy, a very complete binary macroscopic-microscopic energy method is used to perform calculations. Deformed two-center shell model provides the energy level schemes for shell effects. Yukawa-plus-exponential model gives the macroscopic (liquid drop) part of the total energy. The mass tensor is obtained by the Werner-Wheeler irrotational flow hypothesis. Finally the minimization of the multidimensional action integral produces the highest penetrability values. Kr-projectile reactions provide the best pairs, although generally the presentabilities are very low. (author)
We have constructed a mathematical model that describes the coherent spontaneous radiation of a macroscopically filled exciton mode. We have demonstrated qualitatively ways in which a coherent subsystem of excitons can be formed. When this occurs under the influence of an external coherent source, exciton free induction occurs, while in the case of a spontaneous transition of the excitons to a coherent state through freezing of the reservoir of intermolecular interactions superradiance occurs. We have concluded that superradiance in the system of Frenkel excitons is possible under the influence of the non-Dicke mechanisms of self-induction of correlations, when the dipole transition moments of the individual atoms are coupled into a single macroscopic effective spin through their electrostatic interaction, this being analogous to the ordering of magnetic dipole moments in a ferromagnet.
The emergence of nanoscience has increased the importance of experiments able to probe the very local structure of materials, especially for disordered and heterogeneous systems. This is technologically important; for example, the nanoscale structure of glassy polymers has a direct correlation with their macroscopic physical properties. We have discovered how a local, high frequency dynamic process can be used to monitor and even predict macroscopic behavior in glassy polymers. Polyvinylethylenes vitrified by different chemical and thermodynamic pathways exhibit different densities in the glassy state. We find that the rate and amplitude of a high frequency relaxation mode (the Johari-Goldstein process involving local motion of segments of the chain backbone) can either correlate or anti-correlate with the density. This implies that neither the unoccupied (free) volume nor the configurational entropy governs the local dynamics in any general ...
Properties of the multi-species electromagnetic Weibel and electrostatic two-stream instabilities are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters.
The relativistic motion of an electron is numerically analyzed in a tokamak having macroscopic magnetic turbulence. Stochasticity induced by the relativistic motion overwhelms the phase averaging effect, which provides a tokamak with an effective loss mechanism for the avoidance/suppression of runaway electron generation at a major disruption. On the other hand, electrons in the KAM (Kolmogorov-Arnold-Moser) region will be observed as a runaway snake. (author)
Abstract A diacrylate polysulfone oligomer is synthesized and used as the acrylic oligomer for the in situ synthesis of noble metal/PSU nanocomposites through UV-induced simultaneous radical polymerization of acrylic functionalities and NP formation by reduction of their precursors. Thus, silver or gold NPs are formed in situ during polymer network formation. FESEM analysis of the morphology of the cured systems demonstrates that the nanoparticles of the noble metals are homogeneously distributed in the network without macroscopic agglomeration.
The paper presents results of studies on the effect of heat treatment on strength and pattern of 40Kh steel impact failure. Loading levels corresponding to macroscopic spalling microdamage initiation in the material are determined for three initial states. Metallographic study on the spalling failure pattern for 40Kh steel in different initial states and data on microhardness measurement are presented.
This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic steam induced by ultrasonics is a major contribution to heat transfer augmentation. (author).
This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic stream induced by ultrasonics is a major contribution to heat transfer augmentation. (author).
A simplified stormwater management model has been developed to provide an inexpensive, flexible tool for planning and preliminary sizing of stormwater facilities. The model was developed to be part of a methodology for use in the management of stormwater that utilizes both simple...
Progress in four research areas on this project are summarized under the following topics: (1) Geminate charge pair recombination in hexane; (2) Fast current measurements resulting from excitation of charge transfer (CT) states; (3) Measurement of the dipole moment of excited states by DC conductivity; and (4) Charge separation at macroscopic interfaces between electron donor and acceptor solids. In a final section, personnel who have contributed to the project during the past budget period are described.
The extracellular domain of human fibroblast growth factor receptor (XC-FGF-R) was expressed in Escherichia coli. The protein was purified to homogeneity and the interaction with basic fibroblast growth...Full Text Available
In this article, we describe an approach to model the electromechanical behavior of the skeletal muscle based on the Huxley formulation. We propose a model that complies with a well established macroscopic behavior of striated muscles where force-length, force-velocity, and Mirsky-Parmley properties are taken into account. These properties are introduced at the microscopic scale and related to a tentative explanation of the phenomena. The method used integrates behavior ranging from the microscopic to the macroscopic scale, and allows the computation of the dynamics of the output force and stiffness controlled by EMG or stimulation parameters. The model can thus be used to simulate and carry out research to develop control strategies using electrical stimulation in the context of rehabilitation. Finally, through animal experiments, we estimated model parameters using a Sigma Point Kalman Filtering technique and dedicated experimental protocols ...
We consider a Bose-Einstein condensate (BEC) of N atoms of repulsive interaction #approx# U_0, in an elliptical trap, axially pierced by a Gaussian-intensity laser beam, forming an effective (quasi-2D) toroidal trap with minimum at radial distance #rho# = #rho#_p. The macroscopic angular momentum states #PSI#_l(#rho#,#theta#) #approx# #sq root#N#PHI#_l(#rho#)e"i"l"#theta# for integer l spread up to #rho# > #rho#_p. The spreading lowers rotational energies, so estimated low metastability barriers can support large l < or approx. l_m_a_x #approx# (NU_0)"1"/"4, < or approx. 10 for typical parameters. The l-dependent density profile module #PHI#_l(#rho#)"2 -#PHI#_0(#rho#)"2 is a signature of BEC rotation. Results are insensitive to off-axis laser displacements #rho#_0, for #rho#_0 #rho#_m_a_x << 1. (author).
A fractographic and numerical approach is presented to analyze hydrogen-plasticity interactions in pearlitic steel and to elucidate the main hydrogen transport mechanism in this material under triaxial stress states produced by notches. Fractographic analysis showed that the microdamage produced by the hydrogen was clearly detectable by scanning electron microscopy (SEM), through a specific microscopic topography associated with hydrogen effects (tearing topography surface or TTS). Numerical computations obtained by using an elastic-plastic finite element program gave the progressive spreading of the plastic zone, closely associated with the movement of dislocations. In the majority of cases, the plastic zone (PZ) clearly exceeds the hydrogen affected region (TTS) and has no relation with it. In some tests, however, the hydrogen-induced micro-damage surpasses the only region in which there is dislocation movement, and in this case the net macroscopic transport of ...
Kerf geometry, kerf wall features, and cutting front characteristics of an Abrasive Waterjet (AWJ) machined Graphite/Epoxy (Gr/Ep) laminate were studied. A macroscopic analyses suggests that geometrical features associated with AWJ machining of Gr/Ep laminates are influenced by three macro regions along the cutting depth. The presence of these regions, including initial damage at jet entry, smooth cutting, and rough cutting near the jet exit, depends on the operating conditions. Design of experiments and analysis of variance were used to determine the effect of cutting parameters on kerf characteristics and to develop empirical models for kerf profile and features of the three distinct macroscopic regions. Cutting front analysis revealed that the mechanisms of material removal in AWJ machining of Gr/Ep do not change over the jet penetration depth. In general, high quality uniform cuts may be obtained by minimizing initial damage at the jet ...
Violation of correspondence principle may occur for very macroscopic byt isolated quantum systems on rather short timescales as illustrated by the case of Hyperion, the chaotically tumbling moon of Saturn, for which quantum and classical predictions are expected to diverge on a timescale of approximately 20 years. Motivated by Hyperion, we review salient features of ``quantum chaos`` and show that decoherence is the essential ingredient of the classical limit, as it enables one to solve the apparent paradox caused by the breakdown of the correspondence principle for classically chaotic systems.
We study quantum Darwinism -- the redundant recording of information about a decohering system by its environment -- in zero-temperature quantum Brownian motion. An initially nonlocal quantum state leaves a record whose redundancy increases rapidly with its spatial extent. Significant delocalization (e.g., a Schroedinger's Cat state) causes high redundancy: many observers can measure the system's position without perturbing it. This explains the objective (i.e. classical) existence of einselected, decoherence-resistant pointer states of macroscopic objects.
Periosteal Ewing's sarcoma is an uncommon, but well documented origin of this malignant condition with radiography signs, different from intramedullary growing tumours. Imaging modalities like CT or MRI supply proof of macroscopically intact endosteal cortical surface and free medullary cavity in long bones affected by this periosteal type of malignancy. Definite confirmation is valid after a careful microscopic investigation of the resected specimen. The prognosis of this type of Ewing's sarcoma may be favourable than that of the central type. Early diagnosis and therapy are thus essential. A clinical survey of six observations is given. (orig.).
This paper presents fundamental researches based on the electronic structure calculations and X absorption spectroscopy, allowing the knowledge on nuclear fuels at an atomic scale. They bring a better understanding of these material behavior to accurate the macroscopic simulation. The calculation methods, the experimental techniques of validation and the ab initio calculations results are detailed. (A.L.B.)
Nuclear forensics aims at identifying origin and intended use of nuclear material using information inherent to the nuclear material.The information gathered in nuclear forensics include isotopic composition, elemental composition, impurities and age of the material, macroscopic appearance and microstructure. The information so collected helps to solve criminal cases and put the individuals involved in nuclear trafficking in jails. The information also helps to improve safeguards and physical protection measures at place of theft or diversion to prevent future thefts or diversions.
The production of many important commercial materials involves the evolution of a complex fluid through a cooling phase into a hardened product. Textile fibers, high-strength fibers(KEVLAR, VECTRAN), plastics, chopped-fiber compounds, and fiber optical cable are such materials. Industry desires to replace experiments with on-line, real time models of these processes. Solutions to the problems are not just a matter of technology transfer, but require a fundamental description and simulation of the processes. Goals of the project are to develop models that can be used to optimize macroscopic properties of the solid product, to identify sources of undesirable defects, and to seek boundary-temperature and flow-and-material controls to optimize desired properties.
Carbon nano tubes are easily produced in macroscopic quantities, however their characterisation and possible applications are still rather limited. We have developed a new method to make aligned nano tube films which open new opportunities, not only for basic research but also for eventual applications. With this method the tubes can be aligned either parallel or perpendicular to the surface. We give a short review of the microscopic properties of single tubes and the bulk properties of the aligned films. (author). 24 refs., 6 figs.
This work presents results of investigations on d.c. glow discharge nitriding of #alpha#+#beta# Ti-6Al-4V titanium alloy. The treatment was performed at 843 K in nitrogen-hydrogen atmosphere, pressure 300 Pa. Special attention was paid to nitriding mechanism and determination of the role of ion bombarding in nitriding process of titanium alloys. Produced as a result of d.c. plasma nitriding surface layers were subjected to macroscopic observations, microstructure studies, microhardness testing and X-ray analysis. (author)
Growth hormone (GH) has an important role in the regulation of hepatic LDL receptor expression and plasma lipoprotein levels. This investigation was undertaken to evaluate if these effects of GH on...Full Text Available
Target of rapamycin (TOR) kinases control cell growth through two functionally distinct multiprotein complexes. TOR complex 1 (TORC1) controls temporal cell growth and is sensitive to rapamycin, whereas...Full Text Available
Growth of the malolactic bacterium Leuconostoc oenos was improved with respect to both the specific growth rate and the biomass yield during the fermentation of glucose-malate mixtures as compared with...Full Text Available
Mice homozygous for the recessive gene achondroplasia (cn) aged 16 and 17 days and some homozygotes aged 22-34 days have disruptions in the growth of the proximal tibial growth plate which are due solely...Full Text Available
Background and AimsSecondary growth via successive cambia has been intriguing researchers for decades. Insight into the mechanism of growth layer formation is, however, limited to...Full Text Available
The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte...Full Text Available
To express growth-related changes in physiologic or other functions in forms usable for kinetic modeling, we are interested in identifying regular relationships that take the form of simple mathematical...Full Text Available
Insect growth regulators (IGRs) are a class of new chemicals that interfere with maturation and reproduction in insects. Proposed hypotheses on the biochemical mechanism of action are presented herein....Full Text Available
6-Mercaptopurine (6-MP) inhibits the growth of. Escherichia coli B. Growth inhibition is ... reversed by subculture of the cells in 6-mercaptopurine- ...
There is conflicting evidence about the effect of parental consanguinity on fetal growth. Previous studies have not always allowed for other factors that are known to affect birth weight, in particular,...Full Text Available
Transforming growth factor (TGF)-beta isoforms (TGF-beta 1, -beta 2, and -beta 3) regulate cell growth and differentiation and have critical regulatory roles in the process of tissue repair and remodeling....Full Text Available
Single crystal cubic boron nitride (cBN) was heteroepitaxially grown on a seed crystal of diamond under static high pressure and high temperature at 5.5GPa and 1,600--1,700 C, respectively, for 10--100 hour. A temperature gradient method was employed for the crystal growth by using lithium boron nitride as a solvent. Initial growth feature of cBN crystal was found on the diamond seed surface after the growing time of 10 minutes. The nucleation sites of the crystals seem to be near the etch pits on the diamond surface which were introduced by the surface dissolution by the solvent for cBN growth. Two types of growth features, island and step growth were typically shown on the surface. It can be seen that grown crystal appearing as a (111) nitrogen face was exhibited with the step growth feature, while the (11n) face exhibited the island ...
Full text of publication follows: General simulation objectives of any fire analysis are macroscopic in nature and deals with the grass data in respect of fire/smoke spread, structural behaviour, environmental conditions etc. However, the accuracy of predicting such macroscopic parameters is a strong function of several other microscopic parameters which govern the overall macroscopic behaviour. Some of the microscopic parameters of interesting such analysis could be buoyancy induced stable/unstable flows, relative flame behaviour, baroclinic velocity distribution etc. Only the field based fire modelling approach is capable of calculating several of these by way of detailed CFD based field modelling. One of the best known tool that could be employed for such studies is the Fire Dynamics simulator (FDS) from NIST with its popular LES based fire modelling approach. Advanced LES based fire modelling scores over the ...
Liquid-liquid wetting failure is investigated in a two-dimensional Couette system with two immiscible fluids of arbitrary viscosity. The problem is solved exactly using a sharp interface treatment of hydrodynamics (lubrication theory) as a function of the capillary number, viscous ratio and separation of scale, i.e. slip length versus macroscopic scale of the system. The existence of critical velocities, above which no stationary solutions are found, is analyzed in detail in terms of the relevant parameters of the system. Comparisons with existing analysis for other geometries are also carried out. A numerical method of analysis is also presented, based on diffuse interface models obtained from multiphase extensions of the lattice Boltzmann equation (LBE). Sharp interface and diffuse interface models are quantitatively compared face to face indicating the correct limit of applicability of the diffuse interface models.
A new method for kinetic experiments with neutrons is described. This method combines the conventional triple-axis neutron spectroscopy with relaxation-type experiments. Whereas the former method yields information about the microscopic dynamics of solids, the latter provides macroscopic relaxation times. The combination of both methods allows to determine the microscopic mechanism of relaxation processes. The time-resolved triple-axis spectroscopy is limited to reversible processes and to time scales from 10"-"3 to 10"4 s. Typical applications are the kinetics of phase transformations (structural and dynamical changes), kinetics of domain distributions, kinetics of (spinodal) decomposition, reversible solid state reactions, time-dependent occupation of phonon states or phonon lifetimes. (orig.).
Upcoming high-intensity laser systems will be able to probe the quantum-induced nonlinear regime of electrodynamics. So far unobserved QED phenomena such as the discovery of a nonlinear response of the quantum vacuum to macroscopic electromagnetic fields can become accessible. In addition, such laser systems provide for a flexible tool for investigating fundamental physics. Primary goals consist in verifying so far unobserved QED phenomena. Moreover, strong-field experiments can search for new light but weakly interacting degrees of freedom and are thus complementary to accelerator-driven experiments. I review recent developments in this field, focusing on photon experiments in strong electromagnetic fields. The interaction of particle-physics candidates with photons and external fields can be parameterized by low-energy effective actions and typically predict characteristic optical signatures. I perform first estimates of the accessible new-physics parameter space ...
The phase diagram of Gdsub(x)Ysub(1-x)Th_4B_4 between the paramagnetic, superconducting and ferromagnetic state is reported. Low temperature dc-magnetization measurements reveal that macroscopic electro-magnetic effects are of minor importance for the suppression of Hsub(2c), which shows a smooth bell-shaped behavior for x >= 0.15 with no indication of an anomaly near Tsub(c2). At low temperature in samples with x >= 0.20 a transition from type II to type I superconductivity seems to occur. The low temperature normal state susceptibility follows a Curie-Weiss law indicating reentrant behavior for x >= 0.10. (orig.).
A macroscopic realization of the strange virtual particles is presented. The classical Helmholtz and the quantum mechanical Schr\\"odinger equations are analogous differential equations. Their imaginary solutions are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary solutions of this differential equation point to strange consequences: They are non local, they are not observable, and they described as virtual particles. During the last two decades QED calculations of the imaginary solutions have been experimentally confirmed for phonons, photons, and for electrons. The experimental proofs of the predictions of the non-relativistic quantum mechanics and of the Wigner phase time approach for the elastic, the electromagnetic and the Schr\\"odinger fields will be presented in this article. The results are zero tunneling time and an ...
It is suggested that the model of a neutrino ball described in terms of the standard model extended by adding right-handed neutrinos and the Majorana scalar field can be presented in order to explain a body of weak interacting neutrinos. Neutrino interaction with the scalar Majorana field violates the lepton number and produces the mass splitting of neutrino due to the sea-saw mechanism. In this model a neutrino ball is an object which appears as a result of a first order cosmological phase transition. It can be regarded as a ball filled with Dirac neutrinos and can be treated as a remnant of the phase transition with unbroken global lepton symmetry. In this paper we study the macroscopic parameters of such a configuration. In the result the mass-radius curve M(R) for this object is obtained. (orig.).
High-energy synchrotron x-ray diffraction (XRD) has been used to quantify load transfer in bovine plexiform bone. By using both wide-angle and small-angle XRD, strains in the mineral as well as the collagen phase of bone were measured as a function of applied compressive stress. We suggest that a greater proportion of the load is borne by the more mineralized woven bone than the lamellar bone as the applied stress increases. With a further increase in stress, load is shed back to the lamellar regions until macroscopic failure occurs. The reported data fit well with reported mechanisms of microdamage accumulation in bovine plexiform bone.
The determination of ratio of neutron over proton matrix elements by inelastic proton scattering, for 0{sup +}{yields}2{sup +} transitions, is investigated via the comparison between experimental data and theoretical calculations. Calculations into the context of a macroscopic and a microscopic description are performed for a wide mass range nuclei: {sup 18}O, {sup 30}Si, {sup 32,34}S, {sup 48}Ca, {sup 88}Sr, for which these ratios were determined previously with an independent technique. At that point the choice of the theoretical model may be very critical. It is thus the purpose of this investigation to point out the most suitable model. It is found that in general both theoretical models can be employed for the reliable determination of neutron over proton matrix element ratios.
The determination of ratio of neutron over proton matrix elements by inelastic proton scattering, for 0"+#->#2"+ transitions, is investigated via the comparison between experimental data and theoretical calculations. Calculations into the context of a macroscopic and a microscopic description are performed for a wide mass range nuclei: "1"8O, "3"0Si, "3"2","3"4S, "4"8Ca, "8"8Sr, for which these ratios were determined previously with an independent technique. At that point the choice of the theoretical model may be very critical. It is thus the purpose of this investigation to point out the most suitable model. It is found that in general both theoretical models can be employed for the reliable determination of neutron over proton matrix element ratios.
Data and functions of the cell burnup calculation of the SRAC system were revised to improve mainly the accuracy of the burnup calculation of high conversion light water reactors (HCLWRs). New burnup chain models were developed in order to treat fission products (FPs) and actinide nuclides in detail. Group cross section library, SRACLIB-JENDL2, was generated based on JENDL-2 nuclear data file. In generating this library, emphasis was placed on FPs and actinides. Also revised were the data such as the average energy release per fission for various actinides. These improved data were verified by performing the burnup analysis of PWR spent fuels. Some new functions were added to the SRAC system for the convenience to yield macroscopic cross sections used in the core burnup process. (author).
Abstract Introduction: Laparoscopic subtotal adrenalectomy (LSA) has emerged as a treatment option in the management of certain adrenal pathologies. After LSA, a satisfactory blood supply to the adrenal remnant is vital to preserve steroid function. The aim of this study was to review the adrenal blood supply with relevance to LSA. Materials and Methods: The adrenal blood supply was examined in three ways: 1) a review of six previous cadaver studies looking at adrenal blood supply; 2) a review of our 164 consecutive laparoscopic adrenalectomies (LAs) (January 1999?January 2009); the details of the main adrenal veins and variants had been prospectively recorded; and 3) dissection of 4 cadaver specimens (macroscopic and histologic examination was performed). Results: The six cadaver studies ...
Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi{sub 2}-based materials, which are borderline ceramic-intermetallic compounds. MoSi{sub 2} single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi{sub 2} possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi{sub 2}-Si{sub 3}N{sub 4} composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi{sub 2}-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing.
Objective: : Evaluate expression of inducible negative regulators of JAK/STAT pathway and their target proteins during the course of ligature-induced experimental periodontal disease in rats. Design: : Rats were sacrificed 07, 15 and 30days after disease induction for histological evaluation of periodontal inflammation and macroscopic analysis of alveolar bone loss. SOCS expression and the activation status of STAT1 and STAT3 were evaluated in gingival biopsies by real time PCR and Western blot. Results: : Ligature-induced model presented significant progressive bone loss from 7 to 30days. Inflammation was evident and similar for 07 and 15days; however, a decrease on severity at the end of the experimental period was observed. There was a significant (p<0.05) increase on SOCS1 and SOCS3 ge...
Shadow effect was used for investigating damage of uranium dioxide monocrystal. The dependence of shadow minimum parameters on fluence of "2"2Ne ions with 172 MeV energy was followed when detecting fission fragments. Ion dose responsible for sufficient microdamage of lattice structure, included into the classification of heavy ion damage effect on monocrystals was determined. The problem of radiation intensity effect on the character of occurred damages was studied. It was established that macroscopic sample failure, caused by generation of considerable mechanical stresses in monocrystal under beam effect could be observed along with microdamages of lattice structure at ion flux density >10"1"2 cm"-"2Xs"-"1.
Reduction of the metallic impurity concentration in the TCA plasma has enabled us to correlate the observed heating with the calculated position where the rf energy is deposited. In modelling the measured antenna loading due to the presence of Alfven resonance surfaces, and hence inferring the energy deposition profile, both ion cyclotron effects and the toroidal geometry must be considered. In particular, toroidicity couples energy to resonance surfaces that would not be excited in cylindrical geometry. The increase in electron density during a rf pulse changes the positions of these surfaces so that spectrum-related effects may be observed. The appearance of a new surface at the centre of the plasma is seen as a sharp discontinuity on many of the macroscopic parameters, accompanied by evidence of changes in the current density profile. These results, and the predictions of numerical codes, have imposed new constraints on the optimisation of our antenna system.
We develop a large scale parallel viscous-elastic analysis program incorporating a mesoscopic self-consistent model developed by Laws. In the model, macroscopic elastic constants are treated as variables depending on the shape and statistical properties of pre-existing microscopic pores and change due to neutron irradiation. We apply this program to the visco-elastic analysis of nuclear graphite structures under neutron irradiation environment in High Temperature Gas-cooled Reactor (HTGR), as an example problem. Furthermore the calculated results by this parallel computational program are compared with those by one of commercial finite element analysis codes, FINAS, for validating elastic and thermal stress analysis function. (author)
Background Photopolymerizable poly(ethylene glycol) (PEG) hydrogels offer a platform to deliver cells in vivo and support three-dimensional cell culture but should be designed to degrade in sync with neotissue development and endure the physiologic environment. Questions/purposes We asked whether (1) incorporation of degradation into PEG hydrogels facilitates tissue development comprised of essential cartilage macromolecules; (2) with early loading before pericellular matrix formation, the duration of load affects matrix production; and (3) dynamic loading in general influences macroscopic tissue development. Methods Primary bovine chondrocytes were encapsulated in hydrogels (n?=?3 for each condition). The independent variables were hydrogel degradation (nondegrading PEG and degrading olig...
Contrast agent-enhanced CT scans in nine male patients with histologically proved benign lymphoepithelial lesions of the perotid gland were reviewed. All scans showed cystic-appearing masses with peripheral rim enhancement corresponding to the macroscopic appearance of the lesion. Five patients were seropositive for human immunodeficiency virus (HIV) infection or had infections seen in acquired immunodeficiency syndrome. Three patients were members of high-risk groups. Only one patient had symptoms of the SICCA syndrome. Once a rare cause of parotid gland enlargement, benign lymphoepithelial lesions have recently been seen with increasing frequency in patients with HIV infection. Although the CT appearance is not pathognomic, correlation results of aspiration cytology and with clinical history can lead to a preoperative diagnosis of a benign lymphoepithelial lesion.
We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process.
Precipitation-hardened single crystals of a beta (bcc) Ti--40 at. percent V--1.0 at. percent Si alloy were deformed in compression at 77 and 298"0K. The dependence of the yield stress upon aging time at 843"0K for solution-treated crystals shows two maxima which are caused by silicide precipitates. The orientation dependence of the yield stress and of the active macroscopic slip plane were determined as a function of aging time. The solution-treated as well as aged crystals exhibit an asymmetry of both the yield stress and the plane of slip, the degree of asymmetry being larger at 77 than at 298"0K. The asymmetry of slip and yielding is not affected by the presence of precipitation hardening. Results indicate that the effect of the dislocation core structure on dislocation motion is independent of the presence of precipitates. (auth).
The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.
Magnesium fructose-1,6-diphosphate is a novel agent of antimyocardial ischaemia. In the present study, the subchronic toxicity of magnesium fructose-1,6-diphosphate was investigated after 13-week repeated intravenous administration in beagle dogs. The animals received doses of 0, 75, 150 and 300 mg/kg/day (three males and three females for each dose). During the study period, clinical signs, mortality, body weights, food consumption, electrocardiogram, urinalysis, haematology, clinical biochemistry, macroscopic findings, organ weights and histopathology were examined. The administration of magnesium fructose-1,6-diphosphate resulted in increased incidence of clinical signs, including salivation and emesis. These effects were transient and were noted in almost all dogs given 300 mg/kg/day a...
Various chemical, physical, and mechanical methods to prevent unwanted deposition of mineral scale are described. The suitability of the different methods, which largely depends on the specific features and requirements of the system involved, is discussed. Special emphasis is placed upon the threshold treatment, where the growth process is retarded by the addition of trace amounts of growth inhibitors. Growth experiments have been performed on barium sulfate and calcium sulfate dihydrate seed crystals, suspended in a supersaturated solution with and without organic bisphosphonates as inhibitors. Two methods are selected for the analysis of the growth data. A degree of inhibition is defined to obtain a quantitative description of the influence of a growth inhibitor on the growth rate of the crystals. In addition the influence of the molecular structure of ...
Fatigue crack growth tests of three ferrite-pearlite steels with different size and spacing of pearlite particles, which were uniformly distributed in the ferrite matrix, were carried out to investigate the effect of microstructure on fatigue crack growth behavior in the Paris regime. The fatigue crack growth rates for the three materials did not coincide with each other, even when the crack growth curves were arranged by the effective stress intensity factor range. From in situ observations, crack tip stress shielding phenomena, such as interlocking and branching, were found on the crack wake, which enhanced fatigue crack growth resistance. A small size and spacing of pearlite particle seemed to induce small but frequent crack deflections, which resulted in crack closure phenomena. On the...
Research highlights: {yields} The use of resonant photoemission in its 'core-hole clock' expression for the study of the dynamical charge transfer across hybrid organic-inorganic interfaces and for the intermolecular charge transfer in the bulk of organic thin films is reviewed. {yields} The electronic coupling to the substrate and the efficiency of charge transport across hybrid interfaces is different for individual electronic subsystems of the molecular adsorbate. {yields} The intermolecular charge transfer in the bulk of discotic liquid crystals occurs on the order of a few femtoseconds and is faster than expected from the macroscopic charge transport characteristics of the material. -- Abstract: The focus of this brief review is the use of resonant photoemission in its 'core-hole clock' expression for the study of two important problems relevant for the field of organic electronics: the dynamical charge transfer across ...
Non-uniform radionuclide distribution in tumours will lead to a non-uniform absorbed dose. The aim of this study was to investigate how tumour control probability (TCP) depends on the radionuclide distribution in the tumour, both macroscopically and at the subcellular level. The absorbed dose in the cell nuclei of tumours was calculated for {sup 90}Y, {sup 177}Lu, {sup 103m}Rh and {sup 211}At. The radionuclides were uniformly distributed within the subcellular compartment and they were uniformly, normally or log-normally distributed among the cells in the tumour. When all cells contain the same amount of activity, the cumulated activities required for TCP = 0.99 (A-tilde{sub TCP=0.99}) were 1.5-2 and 2-3 times higher when the activity was distributed on the cell membrane compared to in the cell nucleus for {sup 103m}Rh and {sup 211}At, respectively. TCP for {sup 90}Y was not affected by different radionuclide distributions, whereas for {sup 177}Lu, it was slightly ...
A numerical study has been performed to investigate the hydrodynamic aspects of the pool boiling on horizontal-, vertical- and downward-facing surfaces. The FlowLab code, which is based on a Lattice-Boltzmann (LB) model of two-phase flows, is employed. Macroscopic properties, such as surface tension ({sigma}) and contact angle ({beta}), are implemented through the fluid-fluid (G{sub {sigma}}) and fluid-solid (G{sub t}) interaction potentials. The model is found to express a linear relation between the macroscopic properties ({sigma}, {beta}) and microscopic parameters (G{sub {sigma}}, G{sub t}). The simulation results on bubble departure diameter appear to have the same parametric dependence as the empirical correlation. Hydrodynamic aspects of two-phase flow regime transition mechanism are investigated for different surface-coolant configurations. Results of the LB simulation clearly demonstrate that not only the bubble nucleation site density ...
This study addresses the modeling of transdermal diffusion of drugs, to better understand the permeation of molecules through the skin, and especially the stratum corneum, which forms the main permeation barrier of the skin. In transdermal delivery of systemic drugs, the drugs diffuse from a patch placed on the skin through the epidermis to the underlying blood vessels. The epidermis is the outermost layer of the skin and can be further divided into the stratum corneum (SC) and the viable epidermis layers. The SC consists of keratinous cells (corneocytes) embedded in the lipid multi-bilayers of the intercellular space. It is widely accepted that the barrier properties of the skin mostly arises from the ordered structure of the lipid bilayers. The diffusion path, at least for lipophilic molecules, seems to be mainly through the lipid bilayers. Despite the advantages of transdermal drug delivery compared to other drug delivery routes such as oral dosing and injections, the low ...
We have developed a kinetic Monte Carlo (kMC) simulator that links atomic migration and binding energies determined primarily from first principles calculations to macroscopic phenomena and laboratory time scales. Input for the kMC simulation is obtained from a combination of ab initio planewave pseudopotential calculations, molecular dynamics simulations, and experimental data. The simulator is validated against an extensive series of experimental studies of the diffusion of B spikes in self-implanted Si. The implant energy, dose, and dose rate, as well as the detailed thermal history of the sample, are included. Good agreement is obtained with the experimental data for temperatures between 750 and 950 C and times from 15 to 255 s. At 1050o C we predict too little diffusion after 105 s compared to experiment: apparently, some mechanism which is not adequately represented by our model becomes important at this temperature. Below 1050o C, the kMC simulation produces ...
AIM: To investigate the effects of transforming growth factor β1 (TGF-β1) on the differentiation of colonic lamina propria fibroblasts (CLPF) into myofibroblasts in vitro.METHODS:...Full Text Available
Background and AimsIn spatially heterogeneous environments, a trade-off between seedling survival and relative growth rate may promote the coexistence of plant species. In temperate...Full Text Available
Fetal growth restriction (FGR) is an adverse pregnancy outcome associated with significant perinatal and paediatric morbidity and mortality, and an increased risk of chronic disease later in adult life....Full Text Available
The growth regulating factor CTGF/CCN-2 is an integral factor in growth and development, connective tissue maintenance, wound repair and cell cycle regulation. It has recently been reported that CTGF/CCN-2...Full Text Available
Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI...Full Text Available
Objective. To determine relative influences of intrauterine growth restriction (IUGR) and preterm birth on risks of cardiovascular, renal, or metabolic dysfunction in adolescent...Full Text Available
SummaryThe Hippo tumor-suppressor pathway controls tissue growth in Drosophila and mammals by regulating cell proliferation and apoptosis. The Hippo pathway includes...Full Text Available
Epidermal growth factor receptor (EGFR)-specific monoclonal antibodies predominantly inhibit colorectal cancer (CRC) growth by interfering with receptor signaling. Recent analyses have shown that patients...Full Text Available
If bone strength was the only requirement of skeleton, it could be achieved with bulk, but bone must also be light. During growth, bone modelling and remodelling optimize strength, by depositing bone...Full Text Available
Staphylococcus aureus preferentially catabolizes glucose, generating pyruvate, which is subsequently oxidized to acetate under aerobic growth conditions. Catabolite repression of the...Full Text Available
During embryonic development, cells are instructed which position to occupy, they interpret these cues as differentiation programmes, and expand these patterns by growth. Sonic hedgehog...Full Text Available
Recent histological studies suggest relatively rapid growth in dinosaurs. However, the timing of reproductive maturity (RM) in dinosaurs is poorly known because unambiguous indicators of RM are rare....Full Text Available
Many growth factors and hormones modulate the reproductive status in mammals. Among these, insulin and insulin-like growth factor I (IGF-I) regulate the development of gonadal tissues. SH2-B has been...Full Text Available
Epidermal growth factor receptor (EGFR) kinase domain mutations hyperactivate the kinase and confer kinase addiction of the non-small-cell lung cancer (NSCLC) tumor...Full Text Available
Binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) initiates signal transduction, ultimately leading to altered gene expression. Ligand-activated EGFR is also rapidly internalized...Full Text Available
Minoxidil induces hair growth in male pattern baldness and prolongs the anagen phase. All-trans retinoic acid (ATRA) has been reported to act synergistically with minoxidil in vivo:...Full Text Available
Rat somatotropin (growth hormone) was labelled biosynthetically by incubating anterior pituitary lobes with radioactive amino acids for 24 h in a simple buffered salts medium containing glucose. The...Full Text Available
Epidermal growth factor receptor (EGFR) related therapies – mainly tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib, but also monoclonal antibodies targeting EGFR, for example,...Full Text Available
BackgroundAlthough some previous studies have suggested that posttraumatic growth (PTG) is comprised of several factors with different properties, few have examined both the association...Full Text Available
BackgroundPolymorphisms in Epidermal Growth Factor Receptor (EGFR) gene may influence EGFR production and/or activity, thereby modulating susceptibility to lung...Full Text Available
Platelet-derived growth factor (PDGF) is a potent moderator of soft tissue repair through induction of the inflammatory phase of repair and subsequent enhanced collagen deposition. We examined the effect...Full Text Available
Up-flow anaerobic attached-growth bioreactors filled with pre-treated coir fibres ...coir-fibre arranged in bottle-brush configuration bounded by a novel plastic binding technique ...-three anaerobic filter reactors in series -coir fibre as the bacteria growth media a sedimentation
The receptors for IGF-I (IGF-IR) and insulin (IR) have been implicated in physiological cardiac growth, but it is unknown whether IGF-IR or IR signaling are critically required. We generated mice with...Full Text Available
Insect growth regulators (IGRs) of the juvenile hormone type alter physiological processes essential to insect development and appear to act specifically on insects. Three natural juvenile hormones...Full Text Available
OBJECTIVE: We studied 22 dogs to examine the effect of basic fibroblast growth factor (bFGF) alone, in comparison with omental or muscular wrapping on airway healing in a tracheal autotransplantation...Full Text Available
The effect of growth phase on expression of virulence-associated factors was studied by Northern hybridization in an M1T1 clinical isolate of Streptococcus pyogenes. Expression of M...Full Text Available
Bacteria have the ability to adapt to different growth conditions and to survive in various environments. They have also the capacity to enter into dormant states and some bacteria form spores when...Full Text Available
Growth of Lactococcus lactis subsp. lactis biovar diacetylactis was observed on media with citrate as the only energy source. At pH 5.6, steady state was achieved in...Full Text Available
Various factors affecting the aggregation of Actinomyces naeslundii strain 12104 were studied. When the pH of glucose-supplemented growth medium fell below 5.5, the cells aggregated and formed microbial...Full Text Available
This study explored posttraumatic growth (PTG), positive change resulting from struggling with trauma, among 7- to 10-year-olds impacted by Hurricane Katrina. Analyses focused on child self-system...Full Text Available
In the CNS, there are widespread and diverse interactions between growth factors and estrogen. Here we examine the interactions of estrogen and brain-derived neurotrophic factor (BDNF), two...Full Text Available
Both deficiency and excess of growth hormone (GH) are associated with increased mortality and morbidity. GH replacement in otherwise healthy subjects leads to complications, whereas individuals with...Full Text Available
The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays...Full Text Available
... Gastrointestinal Tract On the Growth and Development of Hymenolepis DiminutaKerry L. Dwinell, Paul Bass, Gordon L. Telford, ... central (CNS) nervous systems in the development of Hymenolepis diminuta usi...
We studied the dynamics of microbial communities attached to model aggregates (4-mm-diameter agar spheres) and the component processes of colonization, detachment, growth, and grazing mortality. Agar...Full Text Available
To determine the relative importance of different metabolites of vitamin D in bone growth and development, weanling male rat pups suckled by vitamin D-deficient mothers were given either calcitriol...Full Text Available
Vascular endothelial growth factor (VEGF) plays a critical role in normal development as well as retinal vasculature disease. During retinal vascularization, VEGF is most strongly expressed by not yet...Full Text Available
This paper will discuss initial studies of thin-film GaAs grown by molecular-beam epitaxy for use in developing a thin-film GaAs solar cell. Photocurrent and photoluminescence intensity are related to the material morphology as a function of growth conditions. Growth temperature and V/III ratio have a dramatic effect on the photocurrent. However, it seems likely that even after optimizing such growth parameters, it will be necessary to provide substrates that can provide templates to enhance grain size from the start of thin-film growth. {copyright} {ital 1997 American Institute of Physics.}
DescriptionAbstract of Research Proposal The root environment has a major effect on crop growth, both directly through the supply of water and nutrients to the shoot, and indirectly through root to shoot signalling. Better management of crop root systems through agronomic and genetic means has the potential to improve the efficiency of water and nutrient uptake, and limit root restrictions to crop growth. However, progress in this area is currently limited by the lack of sensors for in situ estimates of [continued...
We study the growth of colonies of the yeast Pichia membranaefaciens on agarose film. The growth conditions are controlled in a setup where nutrients are supplied through an agarose film suspended over a solution of nutrients. As the thickness of the agarose film is varied, the morphology of the front of the colony changes. The growth of the front is modeled by coupling it to a diffusive field of inhibitory metabolites. Qualitative agreement with experiments suggests that such a coupling is responsible for the observed instability of the front.
Roots of maize (Zea mays L.) seedlings continue to grow at low water potentials that cause complete inhibition of shoot growth. In this study, we have investigated the role of abscisic...Full Text Available
In order to better understand the molecular mechanisms of human hair growth control and to test hair growth-modulatory drugs, appropriate in vitro models are required. Here, we report the long-term...Full Text Available
Growth differentiation factor-9 (GDF-9), an oocyte-secreted member of the transforming growth factor β superfamily, progesterone receptor, cyclooxygenase 2 (Cox2; Ptgs2), and the EP2 prostaglandin...Full Text Available
Whether the lusitropic potential of short-term exercise in aged rats is linked to an augmentation in the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and an alteration in the...Full Text Available
The effect of WC particle size with the addition of VC as a grain growth inhibitor was investigated during the liquid phase sintering of WC-Co system. With increasing WC particle size at the same VC content, the effect of grain growth inhibition was increased. Also, with increasing the VC content, the grain shape of WC was changed from the faceted shape to the distorted shape, and the step density of the WC grain was increased. (orig.)
An interface-marker technique has been used to investigate the relative rates of diffusion of Si and of metal atoms during the growth of metal silicide films. The technique enables recognition of a reference plane in thin film diffusion using Rutherford backscattering, while minimizing any perturbation of the diffusion process. Examples are drawn from studies of the growth of silicides of W, Mo, Ta, Nb, Pd and Pt. (orig.).
Vermicompost preparations are increasingly used in agricultural practice. There is a possibility, that crop plants are sensitive to negative effect of vermicompost at early stages of development. The aim of the present study was to test the effects of vermicompost on seed germination and seedling growth of different vegetable crop species. Vermicompost substitution inhibited seed germination and seedling growth with almost linear decrease of growth with increasing concentration of vermicopost in the substrate. However, both leaf chlorophyll content and photochemical activity of photosynthesis increased in all crop species with the exception of pea seedlings. Vermicompost extract as a watering solution showed positive effect on growth of bean and pea seedlings. Germination response of vermi...
Serum growth hormone (GH) was suppressed in female rats bearing mammary tumors induced by 7, 12, dimethylbenz(a)anthracene (DMBA) or N-nitrosomethylurea(NMU). Serum GH was suppressed due to treatment with a human GH analog produced by the plerocercoid stage of the tapeworm Spirometra mansonoides. Rats treated with plerocercoid growth factor (PGF) via plerocercoid infection had accelerated growth rates despite marked reductions in GH levels. Approximately two-thirds of the mammary tumors induced by either DMBA or NMU regressed during three weeks of exposure to PGF while most of the control tumors continued to grow. The data support an important regulatory role for GH in growth of mammary tumors in rats. PMID:3019224
Young rats were given a single irradiation dose (0.5, 2, 5 or 8 Gy) to the left knee-joint. The right unexposed knee-joint served as control. The animals were decapitated 1.5, 3, 7, 14 or 30 days after the irradiation. Longitudinal bone growth in the tibial epiphysis was established using tetracycline as an intravital marker. During the first 1.5 days after irradiation with 5 and 8 Gy, the growth was slightly inhibited (6-7%). Maximum growth retardation (20%) was found 7 to 14 days after irradiation with 5 and 8 Gy. No consistent effect occurred after 0.5 and 2 Gy. Between 14 to 30 days following irradiation growth was normalized.
The power?time curves of mice splenic lymphocytes growth at 37??C affected by ginsenoside Rh2 were determined by microcalorimetry using a 3114/3236 TAM air bioactivity monitor with ampoule mode. Then, the minimal inhibitory concentration (MIC) of Rh2 on splenic lymphocytes growth was determined by serial dilution method. From factor analysis (FA) on six quantitative thermokinetic parameters from the power?time curves, the activity of Rh2 on splenic lymphocytes could be quickly evaluated by analyzing the changes in the two main parameters: growth rate constant k, and maximum heat-output power, P m. The results showed that Rh2 had strong inhibitory activity on splenic lymphocytes growth, and this inhibitory activity was strengthened with increasing concentration of Rh2 in the concentration r...
A novel technique is proposed for the growth of an InN film on a GaN/Al2O3(0001) template by radio-frequency plasma-excited molecular beam epitaxy (RF-MBE). The method involves 1) InN growth under an In-rich condition and 2) additional nitrogen radical irradiation after the InN growth under an In-rich condition. Excess In that appeared on the InN surface in the InN growth under an In-rich condition is transformed to InN by the additional nitrogen radical irradiation. The effective V/III ratio is easily controlled by monitoring the intensity in a reflection high-energy electron diffraction (RHEED) pattern. The growth of the InN film by repeating the InN growth under an In-rich condition and the additional nitrogen radical irradiation is also demonstrated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
The thiazolidinedione (TZD) or glitazone class of peroxisome proliferator-activated-#gamma# (PPAR-#gamma#) ligands not only induce adipocyte differentiation and increase insulin sensitivity, but also exert growth inhibitory effects on several carcinoma cell lines in vitro as well as in vivo. In the current study the in vitro effect of four PPAR-#gamma# agonists (ciglitazone, pioglitazone, troglitazone, rosiglitazone) on the cell growth of seven human neuroblastoma cell lines (Kelly, LAN-1, LAN-5, LS, IMR-32, SK-N-SH, SH-SY5Y) was investigated. Growth rates were assessed by a colorimetric XTT-based assay kit. Expression of PPAR-#gamma# protein was examined by immunohistochemistry and Western blot analysis. All glitazones inhibited in vitro growth and viability of the human neuroblastoma cell lines in a dose-dependent manner showing considerable effects only at high concentrations (10 #mu#M and 100 ...
Postresection villus hyperplasia is a major compensatory mechanism in the short-bowel patient. Substances capable of augmenting postresection mucosal hyperplasia could have therapeutic implications. Human growth hormone (hGH) and human growth hormone releasing factor (hGHRF) stimulate growth of the gastrointestinal tract; however, the diabetogenic actions of growth hormone limit its usefulness in clinical practice. Plerocercoid larvae of the tapeworm Spirometra mansonoides produce an analog of hGH void of diabetogenic side effects. We assessed effects of plerocercoid growth factor (PGF) on mucosal adaptation following 70% proximal jejunoileal resection in young rats. Mucosal weight, DNA, protein, and total sucrase activity per centimeter of bowel were increased in resected PGF-treated animals compared to resected controls. We conclude PGF augments intrinsic postresection mucosal ...
In the framework of nuclear waste transmutation studies, the Mini-INCA project has been initiated at CEA/DSM with objectives to determine optimal conditions for transmutation and incineration of minor actinides (MA) in high intensity neutron fluxes. Our experimental tools based on alpha- and gamma-spectroscopy of the samples and the development of micro fission chambers could gather either microscopic information on nuclear reactions (total or partial cross sections for neutron capture and/or fission reactions) or macroscopic information on transmutation and incineration potentials. Neutron capture cross sections of selected actinides ({sup 241}Am, {sup 242}Am, {sup 242}Pu, {sup 237}Np) have already been measured at ILL, showing some discrepancies when compared to evaluated data libraries but in overall good agreement with recent data. The studies and possibilities offer by the MEGAPIE project to assess neutronic performances of a 1 MW spallation target and the ...
In the framework of nuclear waste transmutation studies, the Mini-INCA project has been initiated at CEA/DSM with objectives to determine optimal conditions for transmutation and incineration of minor actinides (MA) in high intensity neutron fluxes. Our experimental tools based on alpha- and gamma-spectroscopy of the samples and the development of micro fission chambers could gather either microscopic information on nuclear reactions (total or partial cross sections for neutron capture and/or fission reactions) or macroscopic information on transmutation and incineration potentials. Neutron capture cross sections of selected actinides ("2"4"1Am, "2"4"2Am, "2"4"2Pu, "2"3"7Np) have already been measured at ILL, showing some discrepancies when compared to evaluated data libraries but in overall good agreement with recent data. The studies and possibilities offer by the MEGAPIE project to assess neutronic performances of a 1 MW spallation target and the incineration of ...
The electromagnetic properties that present hydrogen and other nucleus of agro-alimentary products, have allowed widely use of magnetic resonance (MR) to study the composition and internal structure of these biological materials in a micro and macroscopic scale, in a nondestructive way. In this paper the physical principles, basic equipment to measure the MR signals and the MR imaging of any biological sample, are explained. It is also shown a review of the main agro-alimentary applications, emphasizing in the use of this principle to examine the internal quality of fruits and vegetables. In these products, the MR has been used to detect and follow the evolution of different factors that determine the internal quality after harvesting, during storage and after post harvesting processes. The main studies that have been conducted with MR in harvested products are about physiological disorders that take place during storage and conservation of fruits in controlled and ...
In this work, a comprehensive model including heat transfer, fluid flow and solidification was used to evaluate the performance of a novel delivery system for a single-belt steel casting process. This near-net-shape casting, although still in development, is one of the most promising routes for casting of low-carbon steel in large scale. This paper focuses on the performance of a low-Re {kappa}-{epsilon} model that was employed to simulate the three-dimensional turbulent flows fully-coupled with heat transfer and macroscopic solidification. Simulations were run for the intended conditions of caster operation, and the results obtained with the {kappa}-{epsilon} were compared with the results obtained with an ad hoc viscosity model, where the molecular viscosity was boosted 100 times, uniformly throughout the computational domain. A semi-analytical solution was employed for validating the models and the results showed that the ad hoc viscosity model overestimated the ...
Our work deals with accumulative roll bonding (ARB) of pure Mg sheet (0.9mm thickness) and of Al5052 sheet (0.5mm). A stacking of Al-Mg-Al was firstly rolled to 50% reduction at 400"0C and secondly ARB has been processed up to 3 cycles. In such multilayers as well as highly mixed composites of two-phased system texture development, phase reactions and strain accumulation are of basic interest, which needs a combination of different experimental methods for characterization. The present paper deals with the global texture evolution measured by thermal neutrons to average always over the whole sample thickness, SEM and optical microscopy indicates the macroscopic development of Mg and Al layers. The initial materials show typical and strong basal plane texture of hexagonal Mg (17.9mrd) and a recrystallization texture of cubic Al (8.5mrd). Co-deformation of Al/Mg/Al leads to strong decrease of both textures, whereas Mg has always a much stronger texture than Al5052. ...
Silicon nitride-based ceramics behavior is strongly influenced by microstructural parameters, which, in turn are determined by chosen densification method. Highly covalent Si-N bond hind are the silicon nitride densification. Therefore, metal oxides are used in order to get high density. However, such oxides must be carefully selected, because they affect the general macroscopic properties of sintered bodies. In the present work, the viability of rare earth concentrate use to produce #beta#--Si_6_-_xAl_xO_xN_8_-_x and its effect on mechanical properties of the sintering ceramics are studied. Additive composition, heating rate, soaking time and sintering temperature were took as variables. Hardness, fracture toughness, Young's modulus and flexural strength were investigated. Lattice parameter compositional dependence and secondary phases crystallized after past-sintering heat treatment were also determined. The results show that rare earth concentrate works very ...
When a highly collimated beam of particles is aimed along the atomic rows of an aligned single crystal, the averaging effect of high speed motion results, to the lowest order of approximation, in crystal electric fields which are transverse to the atomic rows. The enormous magnitude of the crystal transverse electric fields is unsurpassed by any other known earth-bound macroscopic sources. For example, the field strengths along the <100> axis of tungsten at 77 K approach 9{center dot}10{sup 13}V/m. Thus quantum electrodynamic (QED) processes in strong fields which are thought to occur only in the extra-terrestrial environment can now be investigated in the laboratory. Here we review the results of measurements performed at the SPS facility in CERN using highly collimated beams of electrons, positrons and photons in the 20-200 GeV range, and germanium crystals cooled to 77 K with thicknesses ranging from 0.07 mm to 1.40 mm. The focus is on the simplest ...
A calculation program (URA 6.F4) was elaborated on FORTRAN IV language, that through finite differences solves the unidimensional scalar Helmholtz equation, assuming only one energy group, in spherical cylindrical or plane geometry. The purpose is the determination of the flow distribution in a reactor of spherical cylindrical or plane geometry and the critical dimensions. Feeding as entrance datas to the program the geometry, diffusion coefficients and macroscopic transversals cross sections of absorption and fission for each region. The differential diffusion equation is converted with its boundary conditions, to one system of homogeneous algebraic linear equations using the box integration technique. The investigation on criticality is converted then in a succession of eigenvalue problems for the critical eigenvalue. In general, only is necessary to solve the first eigenvalue and its corresponding eigenvector, employing the power method. The obtained results by ...
This report of progress and future objectives timetable is based on an included schematic of goals and objectives and the project abstract which is included as Appendix 1. Five matters are summarized in the order of (1) novel methods of calcified bone confocal microscopy and reconstruction image analysis of decalcified beagle and human cortical bone serial sections, (2) macroscopic cross-correlation of beagle and human cortical and cancellous bone fractions with CT analysis, (3) guidance to the most radiobiologically important skeletal regions of interest with the just completed {sup 90}Sr bone tumor map from life time beagle studies, (4) deposition patterns of radioactive agents that participate in apatite crystal nucleation processes in bone and leave radiation-excited electrons trapped in bone mineral, and (5) the budget period timetable. The discovery that beta particles from {sup 166}Ho (T{sub {1/2}} =26 hr, {beta}{sub max} = 1.8 MeV) phosphonic acid bone ...
This introductory text treats thermodynamics as an incomplete description of quantum systems with many degrees of freedom. Its main goal is to show that the approach to equilibrium -with equilibrium characterized by maximum ignorance about the open system of interest- neither requires that many particles nor is the precise way of partitioning, relevant for the salient features of equilibrium and equilibration. Furthermore, the text depicts that it is indeed quantum effects that are at work in bringing about thermodynamic behavior of modest-sized open systems, thus making Von Neumann's concept of entropy appear much more widely useful than sometimes feared, far beyond truly macroscopic systems in equilibrium. This significantly revised and expanded second edition pays more attention to the growing number of applications, especially non-equilibrium phenomena and thermodynamic processes of the nano-domain. In addition, to improve readability and reduce unneeded ...
The plastic flow behavior of a #beta#-titanium alloy (Ti-15% Mo) was investigated over a wide range of temperatures and strain rates covering those conditions where the #omega#-phase forms dynamically. Portevin-Le Chatelier (PLC) effect was observed in this alloy at temperatures between 575 and 775 K at a strain rate of 1.31 x 10"-"4 s"-"1. The serrated flow behavior of this alloy could be suppressed by rendering the matrix #beta#-phase more stable against the #beta# to #omega# transformation. PLC bands formed in this alloy, studied at different levels of magnification using light, scanning electron and transmission electron microscopy, showed a high density of deformation bands within the macroscopic PLC band. The following mechanism of serrated flow is proposed; the load drop is ascribed to the sudden flow associated with the formation of deformation bands within which #omega#-particles were destroyed while the subsequent load rise results from pinning of ...
The macroscopic rotation of plasma in a toroidal containment device is an important feature of the equilibrium. Toroidal and polidal rotation in the high-beta tokamak Torus II is measured experimentally by examining the Doppler shift of the 4685.75 A He II line emitted from the plasma. The toroidal flow at an average velocity of 1.6 x 10/sup 6/ cm/sec, a small fraction of the ion thermal speed, moves in the same direction as the toroidal-plasma current. The poloidal flow follows the ion diamagnetic current direction, also at an average speed of 1.6 x 10/sup 6/ cm/sec. In view of certain ordering parameters, the toroidal flow is compared with predictions from neoclassical theory in the collisional, Pfirsch-Schluter regime. The poloidal motion, however, results from an E x B drift in a positive radial electric field, approaching a stable ambipolar state. This radial electric field is determined from theory by using the measured poloidal velocity. Mechanisms for the ...
The macroscopic rotation of plasma in a toroidal containment device is an important feature of the equilibrium. Toroidal and poloidal rotation in the high beta tokamak Torus II is measured experimentally by examining the Doppler shift of the 4685.75 A He II line emitted from the plasma. The toroidal flow at an average velocity of 1.6 x 10/sup 6/ cm/sec, a small fraction of the ion thermal speed, moves in the same direction as the toroidal plasma current. The poloidal flow follows the ion diamagnetic current direction, also at an average speed of 1.6 x 10/sup 6/ cm/sec. In view of certain ordering parameters, the toroidal flow is compared with predictions from neoclassical theory in the collosional, Pfirsch-Schluter regime. The poloidal motion, however results from an E x B drift in a positive radial electric field, approaching a stable ambipolar state. This radial electric field is determined from theory by using the measured poloidal velocity. Mechanisms for the ...
Differential cross sections for 201.5 MeV proton scattering form /sup 88/Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') data. In general a good description is obtained for states with ...
Differential cross sections for 201.5 MeV proton scattering form "8"8Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') data. In general a good description is obtained for states with spins ranging ...
An axisymmetric unit cell model based on a regular array of second-phase particles arranged on a BCC lattice is used to study deformation mechanisms of ferrite-pearlite structural steels. Microstructural characteristics of the steels were parameterized by the pearlite volume fraction, the aspect ratio of the pearlite particles, and the neighboring factor, which represents the ratio of interparticle spacing in the longitudinal direction to that in the transverse direction. FE analyses were carried out to investigate the macroscopic and microscopic response of unit cells with morphological features based on idealizations of the microstructures of the actual steels. Tensile properties of each constituent phase were obtained experimentally and used in the analyses. As compared to traditional axisymmetric models, the BCC tell model appears to be able to capture more realistically the behavior of the materials, and it accurately estimates the tensile behavior of the ...
Magnetic resonance imaging (MRI) has rapidly attained a major position among the examinations used in the diagnostic approach of multiple sclerosis because it is highly sensitive in demonstrating lesions. However, these lesional images may have several meanings, and there is the problem of distinguishing between oedema, which is said to reflect recent lesions, and gliosis which is thought to betray old lesions. The intrinsic MRI parameters studied (i.e. relaxation times) are unable to make this distinction, whereas it is provided by paramagnetic contrast media such as gadolinium. There is no correlation between the changes observed at MRI and the severity of the disease. Another problem is the accuracy of lesion localization, since visualization is predominantly macroscopic. This raises several questions about the demonstration of correlations between clinical signs and site of the lesion(s). At the moment, several teams of neuroradiologists are trying to find the ...
Calcium (Ca) plays an important role in regulating various cellular processes. In a variety of cell types, Ca signaling occurs within microdomains where channels deliver localized pulses of Ca which activate a nearby collection of Ca-sensitive receptors. The small number of channels involved ensures that the signaling process is stochastic. The aggregate response of several thousand of these microdomains yields a whole-cell response which dictates the cell behavior. Here, we study analytically the statistical properties of a population of these microdomains in response to a trigger signal. We apply these results to understand the relationship between Ca influx and Ca release in cardiac cells. In this context, we use a first passage time approach to show analytically how Ca release in the whole cell depends on the single channel kinetics of Ca channels and the properties of microdomains. Using these results, we explain the underlying mechanism for the graded relationship between Ca ...
There are few studies on coke's micro-pore structure in recent years, however, micro-pore structure of foundry coke determines its macroscopically quality index and reactivity in cupola furnace. Effect of such factors on micro-pore structure were investigated under different carbonization conditions with certain ratio of raw materials and material forming process in this article as charging temperature (A); braised furnace time (B); heating rate of the first stage (C)and the second stage (D) and holding time of ultimate temperature (E). Research showed that charging temperature was the most influential factor on the coke porosity, pore volume, pore size and specific surface area. It is suggested that formation of plastic mass and releasing rate of volatile during carbonization period are two main factors on microstructure of foundry coke while charging temperature contributes most to the above factors. 6 refs., 4 figs., 9 tabs.
Under severe operating conditions, such as starved lubrication, performance, service life, and reliability of rolling element bearings depend on the chemical and physical interactions between the contacting surfaces, the lubricant components, and the atmosphere. The IMKT{sup 1}, PI{sup 2}, and the imt{sup 3} have been cooperating on systematic investigations of interfacial interactions in high speed grease lubricated ball bearings. These include long time tests with complete bearings lubricated with greases of different composition under defined operating conditions, conducted at the IMKT, and chemical and physical characterizations of the running surfaces at the PI and imt. At the PI, in particular the chemical nature of the boundary layers has been investigated with time of flight secondary ion mass spectrometry (TOF-SIMS). The imt has been involved in the investigations by measuring the physical/mechanical properties of interacting surfaces at the micro/nano-scale after the removal ...
Pressureless-sintered AlN and hot-pressed, pressureless-sintered and reaction-bonded SiC were neutron irradiated at temperatures between 100 and 785degC up to a fluence of 5.2 x 10"2"4 n/m"2. The hardness was increased by up to 51% in AlN and 84% in SiC. The hardness decreased after annealing at temperatures around the irradiation temperature. At the same temperatures, the macroscopic length, which was increased by irradiation, also began to decrease. The hardness and length were almost recovered after 1,200 #approx# 1,400degC annealing. Thus, hardening in irradiated AlN and SiC is controlled by the number of point defects, or, more precisely, by the strain caused by small point defect clusters which pin down dislocation movement. Dislocation loops were still observed in some samples after 1,400degC annealing while the hardness was almost recovered to that in the unirradiated state. Thus, the existence of dislocation loops is not grounds for hardening in irradiated ...
n an early approach, we proposed a kinetic model with multiple translational temperature [K. Xu, H. Liu and J. Jiang, Phys. Fluids {\\bf 19}, 016101 (2007)], to simulate non-equilibrium flows. In this paper, instead of using three temperatures in $x-$, $y-$, and $z$-directions, we are going to further define the translational temperature as a second-order symmetric tensor. Based on a multiple stage BGK-type collision model and the Chapman-Enskog expansion, the corresponding macroscopic gas dynamics equations in three-dimensional space will be derived. The zeroth-order expansion gives the 10 moment closure equations of Levermore [C.D. Levermore, J. Stat. Phys {\\bf 83}, pp.1021 (1996)]. To the 1st-order expansion, the derived gas dynamic equations can be considered as a regularization of Levermore's 10 moments equations. The new gas dynamic equations have the same structure as the Navier-Stokes equations, but the stress strain relationship in the Navier-Stokes ...
In this paper, an investigation was performed on a failure pressure vessel, which was as an anti-freezing heater for General Gas Storage and Distribution (SGZ) system. Evident and serious deformation was observed on the body of the vessel. A metallurgical investigation was conducted to establish the mechanism and cause of deformation of the anti-freezing heater at Daya Bay PWR station in China. The investigation, which was performed on specimens cut from the most serious area deformed of the vessel, included macroscopic examination and microscopy examination. The results of the examinations showed that some lamellar pearlite in the microstructure were already spheroidized. It was confirmed that the vessel was operated at high temperature. Stress analysis for the vessel was conducted. And it was confirmed that, in ideal conditions, the vessel would be deformed at around 420 C. The overall results of the investigation showed that the failure of the protected ...
Soil contamination by liquid organic pollutants represents a serious threat to phreatic ground water. These organic liquids get into the ground and migrate through the porous medium until they finally reach the aquifer. After a critical study of the literature, we listed various existing multiple displacements under three-phase conditions of a disconnected polluting phase that may or not spread over water. The aim of this thesis is to model (at pore scale level) and integrate in the pore network model the various flows that occur when three phases (gas, pollutant and air) are present in a porous medium. The porous medium is supposed completely water-wet. The polluting phase may be connected or not, and the spreading coefficient of the pollutant over water may either be positive or negative. The goal of our study is to obtain macroscopic parameters such as relative permeabilities and capillary pressure. These parameters can be then incorporated in a larger-scale ...
A press formability of magnesium alloy sheet cannot be evaluated by only general characteristics in tensile test; tensile strength, elongation n-value and r-value. For example, AZ31-alloy elongates about 20% in room temperature but breaks easily at shallow stage in deep drawing, which is caused by little local elongation (local necking). Crystallographic restriction of slip deformation in this alloy produces high strength, which almost equal to macroscopic fracture strength. In press forming, the bending under high tension requires a large deformability. A great difference in the deformability between AZ31 magnesium alloy and a strain hardened A1100 Aluminum (only 5% in elongation) is shown by static bending test with V-notch. In a rolled plate of AZ31, a crack is produced by stress concentration and propagates with reduced load at all testing temperature up to 453 K. In contrast, the point of notch in A1100 is dulled by local plastic deformation with held load in ...
Neutron radiography has been put to practical use in foreign countries as one of nondestructive inspection technologies, but in Japan, its application to other scientific fields is mainly researched. The reason is, the neutron radiography apparatuses installed in Japan are hard to be industrially utilized for a number of reasons, but also the characteristics of neutron radiography are not clearly established, and it is not standardized. The part from a collimator through an object to a detector is called ``upstream``, the part of an image detector is called ``midstream``, and the part of image processing is called ``downstream``. The nonparallel property of beam, image distortion and the lack of sharpness, beam quality and the interaction of neutron beam with an object are discussed about the upstream. The intensity of neutron beam, the energy spectra, the effective total macroscopic cross section, the effective energy, the evaluation of scattered beam and ...
The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I model with a scalar massless field has been constructed. In this paper, its effective dynamics is studied in two improved strategies for implementing the LQC discreteness corrections. Both schemes show that the big bang is replaced by the big bounces, which take place up to three times, once in each diagonal direction, when the area or volume scale factor approaches the critical values in the Planck regime measured by the reference of the scalar field momentum. These two strategies give different evolutions: In one scheme, the effective dynamics is independent of the choice of the finite sized cell prescribed to make Hamiltonian finite; in the other, the effective dynamics reacts to the macroscopic scales introduced by the boundary conditions. Both schemes reveal interesting symmetries of scaling, which are reminiscent of the relational interpretation of quantum mechanics and also suggest ...
Deformation mechanisms of Mg-Al-Zn (AZ31) alloys were investigated by performing tensile test at room temperature. In fine grain Mg alloys deformed at room temperature, nonbasal slip systems were found to be active as well as basal slip systems because of grain-boundary compatibility effect. Slip-induced grain-boundary sliding occurred as a complementary deformation mechanism to give rise to c-axis component of strain. With increasing grain size, the activation of the nonbasal slip systems was limited near grain boundaries. Instead of grain-boundary sliding, twinning occurred as a complementary deformation mechanism in large grained samples. Orientation analysis of twins indicated that twinning is induced by stress concentration due to the pile up of basal dislocations. The grain-size dependence on deformation mechanism was found to affect yielding behavior both microscopically and macroscopically which can influence various mechanical properties such as fatigue ...
Various phenomenological theories of wave-type heat transport, which can be interpreted as the models of an isotropic rigid heat conductor with an internal vector state variable, have been proposed in the literature with the objective to describe the second sound propagation in dielectric crystals. The aim of this paper is to analyze the relation between these phenomenological approaches and the phonon gas hydrodynamics. The four-moment phonon gas hydrodynamics based on the maximum entropy closure of the moment equations with nonlinear isotropic phonon dispersion relation is considered for this purpose. We reformulate the equations of this hydrodynamics in terms of energy and quasi-momentum as the primitive fields and subsequently demonstrate that, from the macroscopic point of view, they can be understood as describing the reference model of an isotropic rigid heat conductor with quasi-momentum playing the role of the internal vector state variable. This model is ...
From a macroscopic point of view, corrosion of Zn alloy coated steel sheet occurs by the coating preceding corrosion mechanism; microscopically, however, the coated layer corrosion velocity in the tip of corrosion is different. In order to find the main factors of under-film corrosion of Zn and Zn-Fe alloy coatings in the salt water spray atmospheric exposure test, the correlation between point inflation-exfoliation width and chlorine penetration behavior, point adhesion, and the difference in chlorine penetration behavior due to alloy coating components were investigated. Consequently, the following results were obtained: 1. The better correlation was observed between chlorine penetration distance and point inflation-point exfoliation width. 2. The durability of coating against chlorine penetration improved by increase in point adhesion and Zn content in the coating layer. 3. Zn-Fe (10-20%) alloy coating showed better durability against chlorine penetration than ...
A comprehensive attenuation data of dose equivalent for point isotropic monoenergetic neutron sources up to 400MeV in infinite shields of water, ordinary concrete and iron has been calculated using the ANISN-JR code and a neutron-photon multigroup macroscopic cross section HIL086R. The attenuation factors were fitted to a 4th order polynomial exponent formula, making possible to use easily for point kernel codes. Additional data in finite shielding geometry was also calculated to correct the effect due to infinite medium, giving the maximum correction of 0.23 in the region for more 400 cm distance from neutron source of 400 MeV in iron shield. Effective attenuation length for monoenergetic neutrons have been studied in detail. Subsequently, it was shown that the attenuation length was strongly dependent upon the penetration length and the Moyer`s formula using a single attenuation length brought large error into the dose estimation behind thick shields for the ...
The possibility of improving the cold formability of wrought magnesium alloys is considered in light of their good hot forming characteristics. Magnesium alloy AZ31B sheet is selected as a model system. Parameters affecting formability, such as strain hardening rate, strain rate sensitivity, and the degree of anisotropy are examined systematically by conducting tensile tests over a range of temperatures (room temperature to 250 C) and strain rates (1 x 10{sup -5} to 0.1 s{sup -1}). The plastic anisotropy and deformation texture evolution are examined in samples aligned with the sheet rolling and transverse directions. Polycrystal plasticity simulations using a viscoplastic self-consistent (VPSC) formulation are used to model the observed anisotropy and texture evolution. The adjustable parameters in the model are the relative critical resolved shear stresses of the dislocation mechanisms known to operate within magnesium. The experimental results suggest that an increased strain rate ...
Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriostasis by serum is primarily due to the iron-withholding capacity of transferrin, we considered the possibility that norepinephrine can overcome this effect by supplying transferrin-bound iron for growth. Incubation with concentrations of norepinephrine that stimulated bacterial growth in serum-SAPI medium resulted in loss of bound iron from iron-saturated transferrin, as indicated by the appearance of monoferric and apo- isoforms upon electrophoresis in denaturing gels. Norepinephrine also caused the loss of iron from lactoferrin. The pharmacologically inactive metabolite norepinephrine ...
A factor produced by plerocercoids of the tapeworm Spirometra mansonoides is similar to human growth hormone (hGH) in that it stimulates body growth, binds to hGH receptors, cross-reacts with anti-hGH antibodies, and has lactogenic and insulin-like activities. The purpose of this study was to determine whether plerocercoid growth factor (PGF) is similar to hGH in expressing diabetogenic activity in the genetically obese (ob/ob) mouse. To determine an effective dose for use in the obese mice, the ability of daily injections of PGF to stimulate growth of phenotypically normal mice of the same strain was assessed in a 10-day weight gain assay. Injections of PGF stimulated a dose-dependent weight gain (r = 0.83) and 25 ng eq/day of PGF stimulated a response not significantly different from that produced by 100 micrograms of bovine growth hormone/day. Diabetogenicity was assessed using ...
Macrocephaly was defined as a head measuring larger than 98th percentile. We have evaluated CT findings and head growth curves in 25 infants with large heads. Ten (40%) of 25 infants with large heads were normal developmentally and neurologically. Five (20%) of those were mentally retarded. The other 10 infants (40%) included hydrocephalus (4 cases), malformation syndrome (3 cases), brain tumor (1 case), metabolic disorder (1 case) and degenerative disorder (1 case). Their head growth curves were typed as (I), (II) and (III): Type (I) (excessive head growth curve to 2 SDs above normal); Type (II) (head growth curve gradually approached to 2 SDs above normal); Type (III) (head growth curve parallel to 2 SDs above normal). Ten of macrocephaly with normal psychomotor development were studied clinically and radiologically in details. They were all male. CT pictures of those showed ...
Abstract. Objective: Lapatinib (Tykerb, GW572016), a potent inhibitor of the catalytic activities of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (ErbB2), inhibits population growth of selected EGFR and HER2 overexpressing cell lines. Previous studies with a small number of cell lines suggest a correlation between overexpression of EGFR and/or HER2 and sensitivity to growth inhibition by lapatinib; however, the precise determinants of lapatinib selectivity for tumour and/or other cells remain unclear. Materials and methods: To clarify the determinants of its selectivity in cultured cells, lapatinib-induced cell population growth inhibition and relative EGFR and HER2 protein expression were quantified in 61 different human tumour cell lines fro...
This work is concentrated on growth, spectroscopy and laser performance of thulium-doped vanadate crystals. At the beginning the growth techniques are analyzed and then the matrix of vanadates crystal, its structure and physicochemical properties are explained together with the rare earth activators influence. Detailed spectroscopy of the thulium-doped vanadate crystals then follows. On the background of this theoretical analysis and state of the art of the subject the description of thulium vanadate lasers (especially Tm:YVO"4, Tm:GdVO"4, and Tm:LuVO"4) together with their generated output radiation characteristics are presented.
The solar energy industry experienced unprecedented growth in the eight years from 2000 to 2007, with explosive growth occurring in the latter half of this period. From 2004 to 2007, global private sector investment in solar energy increased by almost twenty-fold, marking a dramatic increase in the short span of four years. This paper examines the timing, magnitude, focus and location of various forms of investment in the solar energy sector. It analyzes their trends to provide an understanding of the growth of the solar industry during the past eight years and to identify emerging themes in this rapidly evolving industry.
The crack growth behavior and fracture toughness of two laminated metal composites (6090/SiC/25p laminated with 5182 and ultrahigh-carbon steel laminated with brass) have been studied in both ``crack arrester`` and ``crack divider`` orientations. The mechanisms of crack growth were analyzed and extrinsic toughening mechanisms were found to contribute significantly to the toughness. The influence of laminate architecture (layer thickness and component volume function), component material properties and residual stress on these mechanisms and the resulting crack growth resistance are discussed.
The inelastic scattering of the beam and the residual gas molecules in RHIC could represent one of the limitations on the beam life time and emittance growth. This report covers the dominant central nuclear collisions influence on the beam lifetime and transverse emittance growth. The cross sections for the beam-gas electron radiative captures are an order of magnitude smaller. The capture cross sections include the radiative and non-radiative capture, and the capture from the electron-positron pair creation from the 'vacuum capture'.
BACKGROUNDHirsutism is the presence of excess body or facial terminal (coarse) hair growth in females in a male-like pattern, affects 5–15% of women, and is an important...Full Text Available
Triacontanol (TRIA) has been realized as a potent plant growth promoting substance for a number of agricultural and horticultural crops. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternative systems of medicine. The mint plant has marvelous medicinal properties. In view of enhancing growth, yield and quality of this medicinally important plant, a pot experiment was conducted according to simple randomized block design. The experiment was aimed at studying the effect of four concentrations of TRIA (10?0, 10?7, 10?6 and 10?5?M) on the performance of mint with regard to growth and other physiological attributes, crop yield and quality attributes and the yield and contents of active c...
The growth power-time curves of a strain of petroleum bacteria, B-2, in various kinds of cultures containing different kinds of carbon sources, glucose, n-tetradecane, n-hexadecane and n-octadecane, and different kinds of microemulsions have been determined by using a 2277 Thermal Activity Monitor. The curves showed a single peak for cultures containing a single carbon source, glucose, and two peaks for cultures containing two kinds of carbon sources, glucose and one of the n-alkanes. The first peak indicated that bacteria grew by consuming glucose and the second peak indicated that bacteria grew by consuming n-alkane. The curves were complex when the bacterium grows in a microemulsion culture. According to a kinetic equation of bacterial growth under limited conditions, the rate constants of bacterial growth were obtained. The results showed that the microemulsion culture was more appropriate to bacteria to grow on ...
The author reviews the growth of the insecticide-resistance problem throughout the world during the period between July 1956 and November 1957, and the developments in research on the subject during...Full Text Available
We report the influence of a small quantity of Cl[sub 2], which enhanced the selectivity of silicon-selective epitaxial growth (Si-SEG) in UHV-CVD using Si[sub 2]H[sub 6], on both the epitaxial growth rate and the B-doping properties for each Si and Si[sub 1-x]Ge[sub x] film. The small quantity of Cl[sub 2] inhibited the Si, Ge and B incorporation, while the selectivity was enhanced. However, it was found, in the case of Si[sub 1-x]Ge[sub x]-SEG using Cl[sub 2], that the reduction ratio of both the growth rate and the B incorporation were smaller than those of Si-SEG with the selectivity still more enhanced. (orig.)
In this study, the thermodynamic stability of the grain boundaries and the grain growth of nanocrystalline Palladium (Pd) at various temperatures were investigated. For this purpose, the Gibbs free energy curves of grain boundaries were plotted in terms of the excess volume by the use of the equation of state (EOS) and Song's thermodynamic models. The results showed that, according to the prediction of these models, the nanocrystalline growth in metals was stopped at the grain sizes less than the critical grain size. Also, the results of the temperature variations and its effect on the Gibbs free energy curves showed that by the increase of the temperature, the possibility for the stoppage of grain growth is facilitated and the critical grain size is increased. To investigate the validity ...
Axon outgrowth and guidance to the proper target requires the coordination of filamentous (F)-actin and microtubules (MTs), the dynamic cytoskeletal polymers that promote shape change and locomotion....Full Text Available
... After formation of the monolayer (usually in 48 hours), the growth medium was poured off, and the cells washed twice with a Henkes solution and ...
The ras oncogenes function by indirectly controlling expression of a subset of yet-undefined genes that are crucial for cell growth and differentiation. In a differential display strategy, numerous...Full Text Available
The effect of different media and pH on the formation of amylase by Aspergillus oryzae EI 212 is described. Depending upon the composition of the medium and growth...Full Text Available
... growth hormone-like factor from plerocercoids of the tapeworm Spirometra mansonoides is a multifunctional protein. In Parasites and pathogens: ... ...
In the formation of A-15 superconducting compounds by solid state diffusion, the time exponent in the growth law under different experimental conditions varies widely from about 0.25 to 1.0. Specific models of growth for different operative rate-controlling conditions are proposed. When the diffusion of B atoms in the matrix is rate-controlling, the thickness of the reacted compound layer increases as tsup(1/2) or tsup(2/3). When the diffusion of B atoms through the compound layer is rate controlling, a tsup(1/2) dependence both for bulk diffusion and grain-boundary diffusion is predicted. When substantial grain growth occurs in the reacted layer during the diffusion anneal, the time exponent observed could be as low as 1/4. Experimental data in support of the predictions of the proposed models are presented. (author).
Photoautotrophic and mixotrophic growth of Lemna paucicostata Hegelm. 6746 (formerly Lemna perpusilla Torr. 6746) was investigated to establish standardized conditions...Full Text Available
This final report for the Swiss Federal Office of Energy (SFOE) presents the results of studies made on the regulation of the growth of Legionella Pneumophila bacteria in biofilms and amoebae. In a first project, the formation of biofilms by Legionella Pneumophila bacteria was analysed in static and dynamic systems using a complex growth medium. Under static and dynamic clinical and environmental conditions, the adherence of the biofilms on polystyrene tissue was studied. This was also examined under dynamic flow conditions. In a second part of the project, the regulation of growth of Legionella Pneumophila in amoebae was examined in that changes were made to the genome of the bacteria. The importance of the work for the de-activation of Legionella Pneumophila bacteria in biofilms is noted in the conclusions of the report.
The trifluoroacetate metal-organic decomposition route to YBa_2Cu_3O_7 film growth was investigated in order to bring new insights in the growth mechanism and its dependence on processing conditions and critical current density. Precursor films were processed on LaAlO_3 substrates at different total pressure, oxygen partial pressure, water vapor partial pressure, and volume gas flow rate keeping the growth temperature at 740 "0C. The influence of these various experimental parameters on the film growth rate, which was evaluated by in situ electrical resistance measurements, was studied thoroughly. It was found that the growth rate is nearly independent of the oxygen pressure and proportional to the square root of the water pressure. Additionally, the growth rate increases with a decrease of the total pressure or an increase of the gas flow rate. An empirical ...
Single crystals of ytterbium tartrate trihydrate have been grown by gel method using silica and agar-agar gels as media of growth. The medium of growth influences the morphology of grown crystals, silica gel yielding single and polycrystalline in the form of spherulites whereas agar-agar gel leading to growth of single and twinned crystals. Materials grown as single crystals have been characterized by using optical and scanning electron microscopy (SEM), EDAX, XRD, FT-IR, CHN and thermogravimetric techniques. The stoichiometry of the grown single crystals is suggested to be Yb(C4H4O6) (C4H5O6).3H2O. The FT-IR spectrum shows the presence of singly as well as doubly ionized tartrate ligands. Results of thermal analysis indicate that the material is thermally stable up to a temperature of 200...
Growth mechanisms and thermal stability of ion-beam-induced epitaxial Pd/sub 2/Si films are investigated using Rutherford backscattering and channelling techniques. Epitaxial growth of Pd/sub 2/Si films was observed at room temperature by argon ion implantation into as-deposited Pd/Si(111) structures and furnace-annealed Pd/sub 2/Si(polycrystalline)/Pd/sub 2/Si(epitaxial)/Si(111) structures. Some additional experiments to check the growth mechanisms are also presented, in which the implantation energies, substrate orientations and dose rates were changed. Finally, the stability of the ion-beam-induced epitaxial Pd/sub 2/Si films on subsequent furnace annealing is studied.
Growth mechanisms and thermal stability of ion-beam-induced epitaxial Pd/sub 2/Si films are investigated using Rutherford backscattering and channelling techniques. Epitaxial growth of Pd/sub 2/Si films was observed at room temperature by argon ion implantation into as-deposited Pd/Si(111) structures and furnace-annealed Pd/sub 2/Si(polycrystalline)/Pd/sub 2/Si(epitaxial)/Si(111) structures. Some additional experiments to check the growth mechanisms are also presented, in which the implantation energies, substrate orientations and dose rates were changed. Finally, the stability of the ion-beam-induced epitaxial Pd/sub 2/Si films on subsequent furnace annealing is studied.
Nanoscale islands of Cu2O have been synthesized on single-crystal SrTiO3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (OPA-MBE). Island growth location has been controlled by using an ex-situ Ga+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. Analysis of Cu2O dot growth on unmodified substrate regions revealed an evolution of dot size and array density. Atomic force microscopy studies show that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of islands. Islands initially formed in the FIB-generated surface topography and filled those features before nucleating on neighboring unmodified surface regions.
Nanoscale islands of Cu_2O have been synthesized on single-crystal SrTiO_3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (MBE). Island growth location has been controlled by using an ex situ Ga"+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex situ atomic force microscopy study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.
Nanoscale islands of Cu?O have been synthesized on single crystal SrTiO? (100) substrates using oxygen plasma assisted molecular beam epitaxy (MBE). Island growth location has been controlled by using an ex-situ Ga? focused ion beam (FIB) to modify the growth surface in discrete locations prior to island sythesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex-situ AFM study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.
Regular fuel reduction burning is an important management strategy for reducing the scale and intensity of wildfires in south-west Australian native forests, but the long term effects of this on tree and stand growth are not well understood. Five fire treatments, including application of frequent and infrequent low intensity burns, and 25?years of fire exclusion, were applied to small (4?ha) experimental plots in a low rainfall mixed jarrah (Eucalyptus marginata) and marri (Corymbia calophylla) forest to investigate the effects of these treatments on tree stem diameter growth, stand basal area increment and tree mortality. Mean tree stem growth measured over 20?years was lowest in the long unburnt treatment compared with the burn treatments, although surface soil nutrient levels were gener...
Cell cultures were prepared from lung tumors occurring in beagles following exposure to inhaled plutonium. Morphologic and growth characteristics of two of these cell lines are described.
The phytochrome photoreceptors and the circadian clock control many of the same developmental processes, in all organs and throughout the growth of Arabidopsis plants. Phytochrome A (phyA) provides...Full Text Available
Changes in soil properties and vegetable growth were quantified on a low-fertility tropical soil. Four treatments (two composts, urea, and control) were applied to an Oxisol (Rhodic Haplustox, Wahiawa series) in a field on Oahu, Hawaii. Chinese cabbage (Brassica rapa, Chinensis group) and eggplant (Solanum melongena) were grown sequentially as test crops. Soil quality as measured by hot-water-soluble carbon, dehydrogenase activity, and cation exchange capacity (CEC) increased by compost amendments. Total organic carbon or carbon dioxide (CO2) respiration rate did not correlate with the soil amendments. Nitrogen (N) nutrition was the main factor that improved growth and carotenoid content in cabbage. The urea treatment promoted better growth in cabbage, whereas good-quality compost, made of...
The authors present an investigation of structural changes occurring in bilayer stacks with crystalline columnar growth when one of the layers is substituted by layers known to grow amorphous. In Co/Cu multilayers the Co layers were substituted by CoZr layers of varying Zr content and layer thickness. Structural characterization was performed by transmission electron microscopy (TEM). They show that the amorphization of the CoZr layers leading to a destruction of the columnar growth depends both on the Zr content and on the thickness of the CoZr layers. Additionally a change to textured growth with a normal to the substrate occurs with increasing Zr content. They explain their observations by a simple picture based on the hard sphere model.
Root growth is a highly dynamic process influenced by genetic background and environment. This paper reports the development of R scripts that enable root growth kinematic analysis that complements a new motion analysis tool: PlantVis. Root growth of Arabidopsis thaliana expressing a plasma membrane targeted GFP (C24 and Columbia 35S:LTI6b-EGFP) was imaged using time-lapse confocal laser scanning microscopy. Displacement of individual pixels in the time-lapse sequences was estimated automatically by PlantVis, producing dense motion vector fields. R scripts were developed to extract kinematic growth parameters and report displacement to ?0.1 pixel. In contrast to other currently available tools, Plantvis-R delivered root velocity profiles without interpolation or averaging across the root s...
From the beginning of the 90s the analysis of the relationships between economic growth and environmental pressures has been influenced by the Environmental Kuznets Curve hypothesis or inverted-U shaped relationship between environmental pressure and per capita income. Following this hypothesis, once achieved certain income level, more economic growth is followed by environmental quality improvement. In this paper, we analyse and discuss the theories that support this hypothesis as well as the empirical evidence on this subject. Further on we analyse the relationship between per capita income and the main environmental pollutants for the case does not support the hypothesis. The empirical evidence shows that economic growth, by itself, does not entail a pollution reduction. (Author) 35 refs.
Sep 1, 2011 ... Title: Application of chloropicrin to Douglas-fir stumps to control laminated root rot does not affect infection or growth of regeneration 16 growing ...
The growth of the Pd{sub 2}Si thin fllms on Si(111) substrates has been monitored by an {ital in} {ital situ} x-ray diffraction technique in vacuum and in helium atmosphere from 160 to 250 {degree}C. A familiar parabolic growth rate was found, confirming the diffusion-controlled film growth process. The activation energies were found to be 1.34 and 1.37 eV for the measurements performed in vacuum and helium environment, respectively. Stress relaxation in the growing Pd{sub 2}Si fllm was observed when the reaction temperature exceeds 200 {degree}C. The relaxed films showed a higher degree of texture as evidenced by the rocking curve measurements.
The growth of the Pd{sub 2}Si thin fllms on Si(111) substrates has been monitored by an {ital in} {ital situ} x-ray diffraction technique in vacuum and in helium atmosphere from 160 to 250 {degree}C. A familiar parabolic growth rate was found, confirming the diffusion-controlled film growth process. The activation energies were found to be 1.34 and 1.37 eV for the measurements performed in vacuum and helium environment, respectively. Stress relaxation in the growing Pd{sub 2}Si fllm was observed when the reaction temperature exceeds 200 {degree}C. The relaxed films showed a higher degree of texture as evidenced by the rocking curve measurements.
Mycoplasma ovipneumoniae is considered an emerging veterinary pathogen causing pneumonia in sheep and goats worldwide. Currently it has not been possible to define a growth medium that yields the maximum growth of M. ovipneumoniae within a short incubation period. Growth yields of M. ovipneumoniae in Eatons medium are variable and not as consistently high as those seen with other Mycoplasma spp. This study investigated the ability of different M. ovipneumoniae field strains to grow in various media formulations, where PPLO broth was replaced by a vegetable protein source, and comparisons were made in terms of strain viability in Eatons medium. Studies were also conducted to determine the optimal carbohydrate source for use in the M. ovipneumoniae medium. Generally, it was found that differ...
Large scale production of monoclonal antibodies has been accomplished using bioreactors with different length to diameter ratios, and diverse impeller and sparger designs. The differences in these physical attributes often result in dissimilar mass transfer, mechanical stresses due to turbulence and mixing inside the bioreactor that may lead to disparities in cell growth and antibody production. A rational analysis of impeller design parameters on cell growth, protein expression levels and subsequent antibody production is needed to understand such differences. The purpose of this study was to examine the impact of Rushton turbine and marine impeller designs on Chinese hamster ovary (CHO) cell growth and metabolism, and antibody production and quality. Experiments to evaluate mass transfer...
Gaseous Nitrogen Dewar apparatus developed by Dr. Alex McPherson of the University of California, Irvine for use aboard Mir and the International Space ...
Hypoxia causes abnormal neonatal pulmonary artery remodeling (PAR) and inhibition of alveolar development (IAD). Transforming growth factor (TGF)-β is an important regulator of lung development...Full Text Available
The Myc oncoprotein is a potent inducer of cell growth, cell cycle progression, and apoptosis. While many direct Myc target genes have been identified, the molecular determinants of Myc’s transcriptional...Full Text Available
The present study is aiming at the visualization of the boiling structures for various pool boiling and flow boiling conditions by applying multiple visualization techniques simultaneously. The bubble growth rate and microlayer behavior were simultaneously visualized for an isolated boiling regime of a water by using a shadow graph and a total reflection technique, respectively
Spatial distributions of turgor and longitudinal growth were compared in primary roots of maize (Zea mays L. cv FR27 × FRMo 17) growing in vermiculite at high (−0.02...Full Text Available
Interchangeable technology from Flexicon Liquid Filling, a business division of Watson-Marlow Pumps Group, has helped family-run diagnostic reagent manufacturer, Hart Biologicals Ltd, to accommodate business growth with the recent upgrade to a tabletop bottle filling and capping machine. A peristaltic dispensing pump is crucial for succes
Smooth muscle cell (SMC) proliferation and migration are key processes that occur in the pathogenesis of atherosclerosis and post-angioplasty restenosis. In the present study, we designed locked nucleic...Full Text Available
An Escherichia coli B strain, B834 galU56, has been isolated which supports growth of bacteriophage T4 with cytosine in its DNA while restricting growth of T4 with hydroxymethylcytosine. This host is...Full Text Available
The discovery of a specific high-affinity growth hormone (GH) binding protein (GH-BP) in plasma adds complexity to the dynamics of GH secretion and clearance. Intuitive predictions are that such a protein...Full Text Available
This paper reports the results of in situ observation of fatigue crack growth in a ferrite?pearlite steel. Stress intensity factor range (?K) decreasing/increasing and constant-?K fatigue tests have been carried out. In banded pearlite orientation, intense crack branching was observed which leads to fatigue crack retardation. Crack closure during the test was monitored to understand the fatigue crack growth behaviour.
A growth model of pitting corrosion of carbon steel in cooling water systems was developed on microscopic observations of pits and electrochemical studies. Results of pitting corrosion measurements in laboratory and field conditions with the model, using a newly developed electrochemical device, are discussed. For an actual heat exchanger up to a year operation, the values of pitting depth estimated were in good agreement with the measured values.
C14, C15, and C16 alkyl nitriles, and C16 and C18 alkyl acetylenes at 10 to 105 micromolar concentrations promote the growth of stem sections from...Full Text Available
Tow experiments were carried out in 1981 and 1982 growth seasons at the greenhouse of the department of agriculture for soils and water researches, atomic energy authority, at inshas, to investigate the responses of two mutation derived lines of sesame and the local cultivar giza 25 to the application of micro nutrients. The possible effect of radiation on germination and growth of sesame seed was also studied in a separate experiment conducted in 1985 season, at inshas.
The three mammalian transforming growth factor (TGF)-β isoforms (TGF-β1, TGF-β2, and TGF-β3) differ in their putative roles in radiation-induced fibrosis in intestine...Full Text Available
BackgroundThe ability of catecholamines to stimulate bacterial growth was first demonstrated just over a decade ago. Little is still known however, concerning the nature of the putative...Full Text Available
Clostridium thermoaceticum ATCC 39073 converted vanillate to catechol. Although carboxylated aromatic compounds which did not contain methoxyl groups were not by themselves growth supportive, protocatechuate...Full Text Available
The objective of the present study was to test the hypothesis that circulating levels of insulin-like growth factor-I (IGF-I) are inversely associated with inflammatory processes in an elderly background population.
Epidermal growth factor (EGF) stimulates adenylyl cyclase in the heart via activation of the stimulatory GTP-binding protein Gs. Therefore, employing peptides corresponding to regions in the cytosolic...Full Text Available
It is now known that various growth factors may also act in the central nervous system. Among them, it has recently been shown that epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) may possess trophic effects in the mammalian brain. We report here on the respective autoradiographic distribution of ["1"2"5I]EGF and ["1"2"5I]IGF-I receptor binding sites in the rat brain, both during ontogeny and in adulthood. It appears that ["1"2"5I]EGF sites are mostly found in the rat forebrain during brain development. On the other hand, ["1"2"5I]IGF-I sites are more widely distributed both during ontogeny and in adulthood. These results reveal the plasticity of the expression of EGF and IGF-I receptor sites in the mammalian brain. This could be relevant for the respective role of these two growth factors in the development and maintenance of neuronal function.
The influence of high temperature thermal ageing treatments on the development of intercrystalline creep damage in two variants of Alloy 800 has been investigated. Ageing up to 3000 h and creep testing were carried out at 800 and 900 C. The high temperature behaviour of the 800HT variant is discussed with reference to the effect of heat treatments on the microstructure. The metallographic methods by which the creep damage was quantitatively determined are described. The growth rate of intercrystalline microcracks was described using a statistical model and the dependence of crack growth rate on the thermal history for both 800HT and 800H was determined. The carbide precipitation and growth processes were determined as functions of the exposure temperature and duration. The results showed the three characteristic stages, precipitation, growth and coarsening (Ostwald ripening). The largest increase in the ...
Plerocercoids of the tapeworm Spirometra mansonoides produce a substance that stimulates growth of experimental hosts. We report purification of plerocercoid growth factor (PGF) to homogeneity by a process involving isolation and solubilization of plerocercoid membranes, isoelectric point selection by chromatofocusing chromatography or preparative isoelectric focusing, and anion-exchange chromatography. A radioreceptor assay (RRA) for human growth hormone (hGH) was used to detect PGF and purity of the 27.5-kDa protein was judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Proteolytic activity was detected in the 27.5-kDa protein by gelatin substrate PAGE. Characterization of PGF as a neutral cysteine proteinase was based on substrate and inhibitor specificities and dependence on pH and thiol-containing reagents. The association of hGH agonist and proteinase activities was shown by comparing RRA ...
Standard Leadframes used in surface mount technology are finished with a layer of eutectic SnPb for passivation and for enhancing solder wetting during reflow. When eutectic SnPb is replaced by Pb-free solder, especially the eutectic SnCu, a large number of Sn whiskers are found on the Pb-free finish. Some of the whiskers are long enough to become shorts between the neighboring legs of the leadframe. How to suppress their growth and how to perform accelerated test of Sn whisker growth are crucial reliability issues in the electronic packaging industry. In this paper, we report the study of spontaneous Sn whisker growth at room temperature on eutectic SnCu and pure Sn finishes. Both compressive stress and surface oxide on Sn are necessary conditions for whisker growth. Structure and stress analyses by using the micro-diffraction in synchrotron radiation are reported. Cross-sectional electron microscopy, ...
The papers contained in this volume provide an overview of recent theoretical and experimental research related to the fracture toughness and fatigue crack growth characteristics of titanium alloys. Topics discussed include room temperature fatigue crack propagation in beta-titanium alloys, fatigue crack growth rate acceleration in alpha+beta Ti alloys, influence of transformed beta microstructures on fatigue crack growth rates in Ti-6Al-4V, and the role of inclusion and pore content on the fracture toughness of powder processed blended elemental Ti-10V-2Fe-3Al. Papers are also presented on fatigue crack growth measurements in an alpha-beta titanium alloy, the effects of thermal processing variation on the properties of Ti-6Al-4V, and the effect of microstructure on ductility and fracture toughness of alpha+beta titanium alloys.
Rhodopseudomonas viridis was grown in liquid culture at 30 degrees C anaerobically in light (generation time, 13 h) and under microaerophilic growth conditions in the dark (generation time, 24 h). The bacterium could be cloned at the same temperature anaerobically in light (1 week) and aerobically in the dark (3 to 4 weeks) if oxygen was limited to 0.1%. Oxygen could not be replaced by dimethyl sulfoxide, potassium nitrate, or sodium nitrite as a terminal electron acceptor. No growth was observed anaerobically in darkness or in the light when air was present. A variety of additional carbon sources were used to supplement the standard succinate medium, but enhanced stationary-phase cell density was observed only with glucose. Conditions for induction of the photosynthetic reaction center upon the change from microaerophilic to phototrophic growth conditions were investigated and optimized for a mutant functionally defective ...
Estimates of annual rates of change of fuel switching are constructed using logistic curve models fitted to often sparse historical data on fuel use in the USA. The estimated annual rate of loss of market share of an old fuel is then shown to be correlated with five-year averages of declines in the rate of growth of affected vehicle numbers. Other statistical tests show a positive correlation between five-year average changes in the rate of growth of the vehicle numbers and of macroeconomic activity when the affected vehicles are directly responsible for a large share of that activity. The vehicle types shown to have this effect are locomotives from 1885-1915 and automobiles thereafter. The third set of tests supports an interpretation that the indirect effects of fuel switches are significant and consistent with GNP throughout the 1880-1980 period. It is shown that a pronounced drop in GNP growth occurs at the time when ...
This paper presents a study on the crystallization and growth mechanism of selenium nanowires induced by silver nanoparticles at ambient conditions with special reference to the effects of factors such as the shapes and size of silver nanoparticles, the induced reaction time, and the molar ratio of Ag{sup 0} to SeO{sub 3}{sup 2-} ions. The synthesis approach is conducted with no need of any stabilizers, and with no sonochemical process and/or templates. It is found that whether silver spherical particles or colloids can lead to the formation of nanowires with average diameter of 25 nm and lengths up to a few micrometers, and silver nanoplates lead to the formation of flat Se nanostructures. In particular, Au, Cu, Pt, and Pd particles cannot induce the growth of selenium nanowires in aqueous solution at room temperature. The results indicate that silver particles play a critical role in determining the growth of selenium ...
A knowledge of surface film growth kinetics can be quite useful in the production of materials for uses ranging from protective coatings to microelectronic devices. A technique for determining the kinetics of film growth is presented which should prove to be a valuable alternative to the array of spectroscopies (AES, RBS, etc.) currently favored for these measurements. Some of the virtues of this X-ray diffraction approach are its non-destructive nature, thickness resolution better than 50 {angstrom} and conventional equipment requirements. Results obtained for the growth of Pd{sub 2}Si films during thermal annealing of Pd coatings on Si, indicate parabolic growth over a temperature range of 160-222 C. The rate constant was found to be k{prime} = 7 {times} 10{sup {minus}4} exp ({minus}1.06 eV/kT) cm{sup 2}/sec, where (film thickness){sup 2} = k{prime} x time. This activation energy is in agreement with ...
An analysis on landscape level was performed to investigate the growth of Scots pine stands (Pinus sylvestris L.) in the research area of 'Duebener Heide' under the impact of rapidly changing pollution loads and to evaluate their further development. Central to the work was a spatial database, installed using a geographic information system (GIS). This database enabled the statistical analysis of relationships and correlations between the growth of the pine stands, the influence of pollution impacts and the natural site characteristics. The results of emission and immission modelling gave detailed evaluation of the pollution load over the investigated area. The spatial information database was linked with a process-based growth model called FORSANA. The resulting regional model was used to simulate forest growth on stand level for variable time periods. The plausibility of the ...
A common evaluation is given for creep crack growth and fatigue crack growth experiments which have been performed at the companies ABB, Siemens-KWU and KFA. The materials under investigation were X10NiCrAlTi32 20 (Alloy 800) and NiCr22Col2Mo (Alloy 617). Several production lots and semi-finished materials as well as welded materials have been tested. Testing techniques differed at the different labs. In order to eliminate the influence of individual testing techniques, material from some production lots was investigated at different labs. The given data cover fatigue crack growth (the materials were tested between room temperature and 1050[sup o]C; the influence of temperature, R-ratio, and frequency was investigated) and creep crack growth (Alloy 800 was tested between 550sup(o)C and 900sup(o)C, Inconel 617 between 800sup(o)C and 1000sup(o)C; the evaluation was done on the basis of the fracture ...
A common evaluation is given for creep crack growth and fatigue crack growth experiments which have been performed at the companies ABB, Siemens-KWU and KFA. The materials under investigation were X10NiCrAlTi32 20 (Alloy 800) and NiCr22Col2Mo (Alloy 617). Several production lots and semi-finished materials as well as welded materials have been tested. Testing techniques differed at the different labs. In order to eliminate the influence of individual testing techniques, material from some production lots was investigated at different labs. The given data cover fatigue crack growth (the materials were tested between room temperature and 1050"oC; the influence of temperature, R-ratio, and frequency was investigated) and creep crack growth (Alloy 800 was tested between 550sup(o)C and 900sup(o)C, Inconel 617 between 800sup(o)C and 1000sup(o)C; the evaluation was done on the basis of the fracture mechanics ...
The effects of temperature and different forms of nutrients on Chattonella marina growth have been investigated in strains isolated from the Daya Bay, the South China Sea. The strain of C. marina preferred high temperatures, with an optimal temperature of 25?C, and 18?C was the minimum for its survival. Higher cell number and growth rate were obtained in high nitrogen and phosphorus concentrations (500 ?g/L, 74 ?g/L) than under nutrient limitation. Nitrogen influenced the growth most, as the specific growth rate and maximum cell density were lower in nitrogenlimited cultures than noted under phosphorus limitation or under limitation from both. C. marina was capable of using many kinds of organic nitrogen sources including L-serine (L-Ser), glycine (Gly), alanine (Ala), L-threonine (L-Thr),...
Maintenance energy expenditures were mesured for five rumen bacteria, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Bacteroides ruminicola, Megasphaera elsdenii, and Streptococcus bovis, by using a complex medium with glucose as the carbon source. Large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. The suggestion is made that maintenance requirements could be a significant determinant of bacterial competition in the rumen. Theoretical maximum growth yields, calculated from double reciprocal plots of yield versus dilution rate, were compared to theoretical Y(ATP) values in order to estimate minimum molar adenosine 5'-triphosphate yields from glucose for each bacterium. Results showed that relative yield among the bacteria was growth rate dependent. At high dilution rates, both S. ruminantium and S. bovis produced lactate as their principal fermentation product. At lower dilution rates ...
Hot-torsion testing was used to establish the cavitation behavior of a typical alpha/beta titanium alloy, Ti-6Al-4V, with a colony microstructure, during simple-shear deformation. For this purpose, sections of deformed specimens were examined by optical metallography, and by scanning and orientation-imaging microscopy (OIM). It was found that cavity nucleation occurred along prior beta boundaries as well as at triple points; in particular, most cavities nucleated along boundaries perpendicular to the axial direction of the specimen. Extensive growth was observed for cavities surrounded by both hard and soft orientations, with the soft colonies accommodating more of the imposed strain. At high degrees of deformation, dynamic globularization of the colony microstructure adjacent to the cavities was also observed. In addition, the metallographic observations revealed that the cavities did not grow in an equiaxed mode, but in an elliptical manner. A tensor describing ...
Systemic sclerosis is an autoimmune connective tissue disorder characterized by a widespread microangiopathy, autoimmunity and fibrosis of the skin and of various internal organs. Microangiopathy is characterized by a reduced capillary density and an irregular chaotic architecture that lead to chronic tissue hypoxia. Despite the hypoxic conditions, there is no evidence for a sufficient compensative angiogenesis in SSc. Furthermore, vasculogenesis is also impaired. An imbalance between angiogenic and angiostatic factors might explain the pathogenetic mechanisms of SSc vasculopathy. As far as angiogenic factors are concerned, within the most important are vascular endothelial growth factor (VEGF) and its receptors, platelet derived growth factor (PDGF), transforming growth factor beta (TGF-?), fibroblast growth factor -2 (FGF-2), angiopoietin 1 (Ang-1), stromal cell-derived factor 1 (SDF-1/CXCL12), ...
A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) in pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition ...
The principle aim of the program was to produce a novel, non-leaching antimicrobial surface for commercial development and future use in the liquid food packaging industry. Antimicrobial surfaces which exist presently have been produced to combat the growth of prokaryotic organisms and usually function as slow release systems. A system which could inhibit eukaryotic growth without contaminating the surrounding 'environment' with the inhibitor was considered of great commercial importance. The remit of this study was concerned with creating a surface which could control the growth of eukaryotic organisms found in fruit juice with particular interest in the yeast, Saccharomyces cerevisiae. Putative antimicrobial surfaces were created by the chemical modification of the test substrate polymers; nylon and ethylvinyl alcohol (EVOH). Surfaces were chemically modified by the covalent coupling of antimicrobial ...
The aim of this work is to simulate the reduction by hydrogen of the tri-uranium octo-oxide U{sub 3}O{sub 8} (obtained by uranium trioxide calcination) into uranium dioxide. The kinetics curves have been obtained by thermal gravimetric analysis, the hydrogen and steam pressures being defined. The geometrical modeling which has allowed to explain the trend of the kinetics curves and of the velocity curves is an anisotropic germination-growth modeling. The powder is supposed to be formed of spherical grains with the same radius. The germs of the new UO{sub 2} phase appear at the surface of the U{sub 3}O{sub 8} grains with a specific germination frequency. The growth reactivity is anisotropic and is very large in the tangential direction to the grains surface. Then, the uranium dioxide growths inside the grain and the limiting step is the grain surface. The variations of the growth reactivity and of the ...
The toxicities of 21 different herbicides to algae (Selenastrum capricornutum and Chlorella vulgaris) and to terrestrial plants (radishes, barley, and bush beans or soybeans) were compared to order to determine the feasibility of using a short-term (96-h) algal growth inhibition test for identifying chemicals having potential toxicity in a 4-week terrestrial plant bioassay. The toxicity of each test chemical, usually in combination with a commercial formulation, was evaluated at six nominal concentrations, between 0 and 100 mg/L growth medium in the algal bioassay or between 0 and 100 mg/kg substate in the terrestrial plant bioassay, in terms of both (1) the no-observed-effect concentration (NOEC), i.e., the highest concentration tested at which no significant (P < 0.05, one-sided test) reduction in algal growth rate or in terrestrial plant yield, relative to controls, was observed; and (2) the concentration at which ...
The major effect of immobilization during growth is a smaller bone mass induced by either an increased bone resorption or a decreased bone formation. Using a method of analyzing radioisotopic loss of (/sup 3/H)tetracycline and (/sup 3/H)collagen from bone prelabeled in vivo, we compared the amount of bone resorption due to immobilization with bone resorption induced by growth. One hind limb was denervated in growing male rats, 6 weeks of age, that had been chronically prelabeled with (/sup 3/H)tetracycline, /sup 45/calcium, and (/sup 3/H)proline. The total radioactivity of the whole femur and tibia/fibula from the denervated limb was compared with that from bones of the control limb at 0, 1, 2, 4, and 8 weeks after denervation. The effect of growth on bone formation was measured by net increases in bone length, volume, and mass of matrix and mineral. Experimental bones had a significantly smaller volume and mass. Bone ...
Alexandria is the second largest urban governorate in Egypt and has seen significant urban growth in its modern and contemporary history. This study investigates the urban growth phenomenon in Alexandria, Egypt, using the integration of remote sensing and GIS. The urban physical expansion and change were detected using Landsat satellite images. The satellite images of years 1984 and 1993 were first geo referenced, achieving a very small RMSE that provided high accuracy data for satellite image analysis. Then, the images were classified using a tailored classification scheme with accuracy of 93.82% and 95.27% for 1984 and 1993 images respectively. This high accuracy enabled detecting land use/land cover changes with high confidence using a post-classification comparison method. One of the most important findings here is the loss of cultivated land in favour of urban expansion. If the current loss rates continued, 75% of green lands would be lost ...
Coal exploitation inevitably damages the natural ecological environment through large scale underground exploitation which exhausts the surrounding areas and is the cause of surface subsidence and cracks. These types of damage seriously lower the underground water table. Deterioration of the environment has certainly an impact on and limits growth of vegetation, which is a very important indicator of a healthy ecological system. Dynamically monitoring vegetation growth under coal exploitation stress by remote sensing technology provides advantages such as large scale coverage, high accuracy and abundant information. A scatter plot was built by a TM (Thematic Mapper) infrared and red bands. A detailed analysis of the distributional characteristics of vegetation pixels has been carried out. ...
According to the environmental Kuznets curve hypothesis, environmental degradation increases in the early stages of growth, but it eventually decreases as income exceeds a threshold level. It is thus often argued that if international trade increases incomes then it can also have a positive impact on environmental quality. So far, these hypotheses have been widely empirically tested for the developed countries. However, it is still uncertain whether positive effects of international trade on growth and on the environment may also hold in developing countries. One of the major difficulties in testing these relations in developing countries is the poor quality of environment related data. In this analysis this problem is reduced by constructing a structural equation model (SEM) with three la...
The economic development of eastern Europe was associated during the last 15 years with the following average annual increases in energy consumption: Approximately 1% in the sectors industry, building and transport, almost 7% in the farming sector, approximately 3% in households, and nearly 4% in the municipal sector. This trend will not continue. As the economic system shifts from centrally planned to free economy and as the previously secluded economy is forced to face world market conditions as well as changed pars of exchange and conditions of payment, it not only experiences a transitory, sharp dip of economic growth in general but, in particular, drastic structural changes. - While there is to be expected, on the whole a slump in national economic growth, in tradiational branches of industry (e.g., metallurgy, the chemicals and textile industry) as well as in farming, such sectors as the service industry and small trade are expanding. ...
The thermal spike model has been successfully applied to track formation by swift heavy ions in insulators. Arguments are given supporting the assumption that the thermal spike mechanism is also valid for the anisotropic growth. The glass transition temperature is used as the main thermal parameter of the amorphous solids. Experimental results on the track formation in {alpha}-quartz and in crystalline Ni{sub 3}B and also on the anisotropic growth in Pyrex and Synsil glasses, in amorphous Pd{sub 80}Si{sub 20}, Ni{sub 3}B and Fe{sub 85}B{sub 15} are discussed. Good agreement is found with the predictions of the thermal spike model. (orig.).
Many human diseases are associated with protein aggregation and fibrillation. We present experiments on in vitro glucagon fibrillation using total internal reflection fluorescence microscopy, providing real-time measurements of single-fibril growth. We find that amyloid fibrils grow in an intermittent fashion, with periods of growth followed by long pauses. The observed exponential distributions of stop and growth times support a Markovian model, in which fibrils shift between the two states with specific rates. Remarkably, the probability of being in the growing (stopping) state is very close to 1/4 (3/4) in all experiments, even if the rates vary considerably. This finding suggests the presence of 4 independent conformations of the fibril tip; we discuss this possibility in terms of the existing structural knowledge.
Backgrounds and Aims The stem growth habit, determinate or indeterminate, of soybean, Glycine max, varieties affects various plant morphological and developmental traits. The objective of this study is to identify the effect of stem growth habit in soybean on the stomatal conductance of single leaves in relation to their leaf morphology in order to better understand the ecological and agronomic significance of this plant trait. Methods The stomatal conductance of leaves on the main stem was measured periodically under favourable field conditions to evaluate gmax, defined as the maximum stomatal conductance at full leaf expansion, for four varieties of soybean and their respective determinate or indeterminate near isogenic lines (NILs). Leaf morphological traits including stomatal density, ...
Mentha pulegium L. is a medicinal and aromatic plant belonging to the Labiatae family present in the humid to the arid bioclimatic regions of Tunisia. We studied the effect of different salt concentrations on plant growth, mineral composition and antioxidant responses. Physiological and biochemical parameters were assessed in the plant organs after 2?weeks of salt treatment with 25, 50, 75 and 100?mM NaCl. Results showed that, growth was reduced even by 25?mM, and salt effect was more pronounced in shoots (leaves and stems) than in roots. This growth decrease was accompanied by a restriction in tissue hydration and K+ uptake, as well as an increase in Na+ levels in all organs. Considering the response of antioxidant enzymes to salt, leaves and roots reacted differently to saline conditions...
Inert markers (evaporated tungsten and silver) were used in growth studies of silicides formed both by thermal annealing and by ion mixing in the Ni/Si, Pd/Si, and Cr/Si systems. The markers were initially imbedded inside silicides and backscattering spectrometry was used to determine the marker displacement after different processing conditions. The results obtained in thermal annealing are quite consistent with that found in previous investigations. Ni is the dominant diffusing species in Ni_2Si, while Si is the diffusing species in CrSi_2. In Pd_2Si, both Pd and Si are moving species with Pd the faster of the two. In contrast, in growth of silicides by ion irradiation Si is the faster diffusing species in all three systems.
Inert markers (evaporated tungsten and silver) were used in growth studies of silicides formed both by thermal annealing and by ion mixing in the Ni/Si, Pd/Si, and Cr/Si systems. The markers were initially imbedded inside silicides and backscattering spectrometry was used to determine the marker displacement after different processing conditions. The results obtained in thermal annealing are quite consistent with that found in previous investigations. Ni is the dominant diffusing species in Ni/sub 2/Si, while Si is the diffusing species in CrSi/sub 2/. In Pd/sub 2/Si, both Pd and Si are moving species with Pd the faster of the two. In contrast, in growth of silicides by ion irradiation Si is the faster diffusing species in all three systems.
Proteins aggregated into spherulite structures of amyloid fibrils have been observed in patients with certain brain diseases such as Alzheimers and Parkinsons. The conditions under which these protein spherulites form and grow are not currently known. In order to illuminate the role of environmental factors on protein spherulites, this research aims to explore the kinetics and mechanisms of spherulite formation and growth, as monitored by optical microscopy, in a range of salt concentrations, and initial protein concentrations for two model proteins: bovine b-lactoglobulin and insulin. These two proteins are significantly different in their size and fibril growth rate, but both of these proteins have been shown previously to form amyloid fibrils and spherulites under low pH conditions. The...
The development of calcium sulfate dihydrate (gypsum) mineral scale in reverse osmosis (RO) membrane desalting was investigated by direct real-time observation of crystal growth. Gypsum scaling studies were conducted in a specially modified plate-and-frame reverse osmosis cell fitted with an optical window, with dark-field membrane lighting arrangement within the membrane cell to enhance crystal boundaries and allow recording of digital surface images magnified through an optical microscope. The evolution of the surface number density (SND) of gypsum crystals resembled a sigmoidal population growth process with an increasing rate of crystal formation at higher solution supersaturation (with respect to gypsum) at the membrane surface. The rate of formation of new crystals declined as the su...
Plutonium oxide fuel pellets for powering radioisotopic thermoelectric generators for NASA space vehicles are encapsulated in iridium which has been grain-boundary-stabilized with thorium and aluminum. After aging for 6 months at 1310/sup 0/C under vacuum, enhanced grain growth is observed in the near-surface grains of the iridium next to the PuO/sub 2/. Examination of the grain boundaries by AES and SIMS shows a depletion of thorium and aluminum. Iron, chromium, and nickel from the fuel were found to diffuse into the iridium along the grain boundaries. Enhanced grain growth appears to result from thorium depletion in the grain boundaries of the near-surface grains next to the fuel. However, in one instance grain growth was slowed by the formation of thorium oxide by oxygen diffusing up the grain boundaries.
Abstract A Pseudomonas sp. isolate MSB1 efficiently inhibited the growth of Flavobacterium psychrophilum of different serotypes on agar medium. A significant difference in the inhibition was observed between isolates of the less virulent FpT serotype compared to the Fd and Th serotypes. In broth coculture experiments, a low number of cells of MSB1 inhibited and outcompeted the F.psychrophilum cells. Also cell-free culture supernatant of MSB1 clearly repressed the growth of F.psychrophilum. A chromoazurol S assay suggested that MSB1 produced efficient siderophores, which most probably were responsible for the iron deficiency in the supernatant. The limited growth of F.psychrophilum in the supernatant was found to be partly because of the lack of available iron, but the results also indicate...
Increased levels of epidermal growth factor receptor have been reported in a variety of tumors, including pulmonary squamous cell carcinomas in man. The purpose of this study was to determine if increased levels of epidermal growth factor (EGFR) were present in lung tumors from Beagle dogs that had been exposed to "2"3"9PuO_2- Using immunohistochemical techniques, sections from 17 lung tumors were examined for the presence of EGFR. Seven of the tumors were strongly positive for EGFR; the remainder of the tumors and the normal lung sections were negative. The positive immunostaining could not be correlated with the histologic phenotype of the tumors. Work is in progress to determine the level of EGFR in preneoplastic, proliferative epithelial foci in the Iung. (author)
The thermodynamic aspects of indium-face InN growth by radio frequency plasma-assisted molecular-beam epitaxy (rf-MBE) and the nucleation of InN on gallium-face GaN (0001) surface were investigated. The rates of InN decomposition and indium desorption from the surface were measured in situ using reflected high-energy electron diffraction and the rf-MBE 'growth window' of In-face InN (0001) was identified. It is shown that sustainable growth can be achieved only when the arrival rate of active nitrogen species on the surface is higher than the arrival rate of indium atoms. The maximum substrate temperature permitting InN growth as a function of the active nitrogen flux was determined. The growth mode of InN on Ga-face GaN (0001) surface was investigated by reflected high-energy electron diffraction and atomic force microscopy. It was found to be of the Volmer-Weber-type for substrate ...
In tomato crop, the induction of resistance emerges as an important alternative for achieving the reduction of chemicals in disease control. This study aimed to evaluate the ability of 28 Trichoderma isolates to promote the growth of tomato seedlings and to induce systemic resistance (ISR) against Xanthomonas euvesicatoria and Alternaria solani, the causal agents of bacterial spot and early blight, respectively. Twelve isolates promoted the increase of plant dry matter mass (DMM) above 100%, showing the great potential of these strains. All isolates were able to colonize the root system of tomato plants. The plant growth-promoting isolates were further evaluated for potential elicitation of ISR. Treatment of the soil with all Trichoderma isolates provided protection in tomato plants from 2...
Pots used for experiments conducted on plants grown in them create rooting environments that are affected by limited soil volume, which can affect various physiological processes, including transpiration, and plant growth. However, the applicability of results from pot experiments to the field has received limited attention. The objective of this study was to compare the growth and transpiration of maize (Zea mays L.) and winter wheat (Triticum aestivum L.) when grown in pots and field plots under various constant water deficits. The experiments were conducted under similar environmental conditions for both pots and plots. Transpirational responses at both transient (RTTr) and daily (RDTr) time scales to a decreasing fraction of available soil water (FASW) were analyzed. For a comparable F...
The effect of water shortage on growth and gas exchange of maize grown on sandy soil (SS) and clay soil was studied. The lower soil water content in the SS during vegetative growth stages did not affect plant height, above-ground biomass, and leaf area index (LAI). LAI reduction was observed on the SS during the reproductive stage due to early leaf senescence. Canopy and leaf gas exchanges, measured by eddy correlation technique and by a portable photosynthetic system, respectively, were affected by water stress and a greater reduction in net photosynthetic rate (A N) and stomatal conductance (g s) was observed on SS. Chlorophyll and carotenoids content was not affected by water shortage in either condition. Results support two main conclusions: (1) leaf photosynthetic capacity was unaffec...
Keratinocyte growth factor receptor (KGFR) and fibroblast growth factor receptor (FGFR) 2c share identical amino acid sequences, except for a 46-amino acid domain in the extracellular region. Monoclonal antibodies (MAbs) specific to KGFR have not been reported nor are commercially available. In this study, we generated murine MAbs specific to KGFR in non-obese diabetic (NOD) mice using a modified Repeated Immunizations at Multiple Sites (RIMMS) technology. Stable cell lines expressing the full-length human KGFR or FGFR2c were produced to facilitate the identification of KGFR-specific MAbs. Following the initial screening of hybridoma clones with a fluorescence-based, confocal cell detection method and ELISA, KGFR-specific MAbs were selected and confirmed by flow cytometry and Western blot ...
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis.This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of "hot air" which is significant to the implementation of the Kyoto Protocol. In addition, through the ...
The grain morphology developed during solidification of an Al-4.5% Cu alloy is represented generally by columnar or equiaxed dendrites. Twinned feathery grains are found in the structure formed under certain heat and flow conditions during solidification. In this work, these conditions were achieved during solidification in a cavity under forced flow. Feathery grain formation is studied by means of fluid dynamics simulations with solidification included and by experiments. In order to determine the crystallographic orientation of feathery grains, electron backscattered diffraction measurements were performed. The growth features of feathery grains were analyzed by observations made normal and parallel to the growth direction. Some correlations between twinned feathery morphology, flow and ...
This book is mainly a comparison of the cost of pollution with the cost of environmental protection. As to the causes of pollution, a difference is made between pollutants that accumulate and pollutants that do not accumulate. Because of pollutant accumulation it is necessary to carry out both subsequent pollution abatement measures and to take preventive action which helps to avoid pollutant emission. Growth models serve to substantiate why such preventive action is both ecologically and economically useful as a rule. Finally the study makes a comparison between some tools of environmental protection. It stresses in particular that, if a duty on emissions is levied, the polluter has to bear all the cost of the pollution, while at the same time the quality of the environment can be more successfully improved than by emission standards alone.
Abstract Mammalian teeth exhibit incremental structures representing successive forming fronts of enamel at varying time scales, including a short daily increment called a cross striation and a long period called a stria of Retzius, the latter of which, in humans, occurs on average every 8-9 days. The number of daily increments between striae is called the repeat interval, which is the same period as that required to form one increment of bone, i.e. the lamella, the fundamental - if not archetypal - unit of bone. Lamellae of known formation time nevertheless vary in width, and thus their measures provide time-calibrated growth rate variability. We measured growth rate variability for as many as 6 years of continuously forming primary incremental lamellar bone from midshaft femur histologic...
The kinetics of passive film formation on iron in borate buffer solution has been studied at different anodic potentials. The process of film growth has been found to occur in four distinct stages. About 80-90% of the total film thickness formed in 1h grows during the initial two stages which last for only 1-3s (depending upon potential). The electric field strength across the film is not constant but decreases with progressing film growth. The thickness of the film determined ellipsometrically is less than that calculated from the electric charge consumed. The process of anodic film formation is accompanied by the dissolution of iron which occurs over the whole range of potentials.
Rare earth elements (REEs) are widely used to increase crop production in China. However, little attention has been paid to their impacts on aquatic ecology. Batch cultivation was used here to study the effects of lanthanum (La) and EDTA on the growth and competition of the cyanobacterium Microcystis aeruginosa and the green alga Scenedesmus quadricauda. When EDTA was present at a very low concentration (0.269mmolL-1), low lanthanum concentrations (7.2mmolL-1) had little stimulative effect on the growth of M. aeruginosa and S. quadricauda, whereas a high lanthanum concentration (72mmolL-1) had significant inhibitory effect on both of them. The results of cultivation experiments suggested that the inhibitory effect on M. aeruginosa was higher than that on S. quadricauda and S. quadricauda c...
The growth response, total hemocyte count (THC), respiratory burst (release of superoxide anion), phenoloxidase (PO) activity, superoxide dismutase (SOD) activity, nitric oxide synthase (NOS) activity as well as resistance to the pathogen Vibrio alginolyticus were measured in Litopenaeus vannamei, which had been fed diets supplemented with glycyrrhizin (the aqueous extract of licorice, Glycyrrhiza glabra, roots) at 0, 50, 100, 150, and 200 mg/kg of feed for 8 wk. In the feeding trial, there was no significant difference in survival rate (P > 0.05). Significant higher specific growth rate was observed in treatments with dietary glycyrrhizin than that in the control group (P < 0.05). Shrimp fed a diet with 200 mg/kg of glycyrrhizin had significant higher THC, PO activity, respiratory burst a...
An Fe-15Cr-20Ni ternary model alloy and a Type 316 stainless steel were irradiated by dual-ions at 1 to 50 appm of He/dpa ratios, to investigate the helium effects on microstructural development in austenitic alloys under irradiation. Quantitative analysis on resultant microstructures revealed that the Frank loop nucleation rate and the network dislocation density positively correlate and Frank loop growth rate negatively correlate with the He/dpa ratio, while the cavity growth rate has its peak at an intermediate helium injection rate. Although He/dpa dependence of various microstructural features were similar for the model alloy and the 316SS, the rates of their development and the mechanism which had assisted cavity growth were significantly different in these two materials. (orig.).
In order to replace copper fungicides in organic potato production, 53 copper-free preparations (CFPs) based on natural compounds, including plant extracts and microorganisms, and five copper preparations were evaluated for their potential to control Phytophthora infestans, the pathogen that causes late blight of potatoes. In in vitro assays, 30% of the CFPs inhibited indirect germination of sporangia, 26% mycelial growth and in growth chamber experiments, 21% efficiently reduced foliar blight of tomato plants. In micro-plot field trials with applications twice a week, the copper preparations were the most effective and reduced foliar blight by 99%. Of the CFPs tested, Oekofluid P, Mycosin and other sulphuric clays, and C-2000 reduced late blight the most, from 63% to 37%. In small-plot tr...
Atrazine is one of the most commonly used herbicides in the United States. While effective on target plants, it has been associated with harmful health effects in non-target organisms such as fish, amphibians and mammals. In this study, growth effects on human liver cells were determined after exposure to increasing concentrations of this herbicide. Growth of immortalized human hepatoma HepG2 cells was inhibited by atrazine concentrations of 625 ppb after 72 h exposure and flow cytometry analysis demonstrated HepG2 cells exposed to 100 ppb atrazine accumulated in S phase after 48 h compared to untreated cells. Expression of cell cycle specific cyclin proteins was altered after atrazine exposure with cyclin E levels significantly decreased after a 24 h exposure and cyclin B levels decreased...
Goldstein SL, Mattoo TK, Morgenstern B, Martz K, Stablein D, Talley L. Anemia and growth status in pediatric patients receiving maintenance dialysis after a failed renal transplant course: An NAPRTCS report.Pediatr Transplantation 2006. Copyright 2006 Blackwell Munksgaard Abstract: We conducted a retrospective review of the North American Renal Transplant Cooperative Study (NAPRTCS) Registry transplant and dialysis arms to assess anemia and growth patterns in children who returned to dialysis after a failed renal transplant from January 1, 1992 to February 3, 2004. Of the 1807 potential study subjects, 1451 had transplant removal data (TxIn vs. TxOut) available for analysis. Four hundred and twenty-one of 1451 patients (29%) had a transplant nephrectomy at the time of entry into the NAPRTC...
We carried out theoretical analyses based on ab initio calculations that incorporate free energy of the vapor phase in order to determine the initial growth process of cubic GaN on GaN (001)-(4x1). The results suggest that a N-adsorbed structure appears at the initial growth stage and then Ga adsorbs on the N-adsorbed GaN (001)-(4x1) surface. Considering this process, we performed Monte Carlo simulations. The results suggest that the maximum point of Ga coverage after supplying a Formula Not Shown monolayer of atoms shifted toward a Ga-rich condition from V/III=1.0.
We briefly reviewed and summarized the experimental study on {beta}-delayed proton decays published by our group over the last 8 years, namely the experimental observation of {beta}-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N{approx}Z by utilizing the p-{gamma} coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for {sup 85}Mo, {sup 92}Rh, as well as the predicted 'waiting point' nuclei {sup 89}Ru and {sup 93}Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moeller et al. [At. Data Nucl. Data Tables 66,131(1997)]. These data considerably influenced the predictions ...
The work in the past year has primarily involved four areas of magnetic thin films: amorphous rare earth-transition metal alloys, epitaxial CoPt{sub 3} and Ni-Pt alloy thin films, amorphous rare earth doped Si (a new class of dilute magnetic semiconductor with large negative magnetoresistance which the authors have discovered), and exchange-coupled antiferromagnetic insulators. In the amorphous alloys, they made a systematic study of the effects of local anisotropy, macroscopic (perpendicular) anisotropy, and exchange constant on the fundamental (and practical) properties of these magnetic alloys, as originally described in the grant proposal. The work on the epitaxial Co-Pt (and more recently Ni-Pt) alloys was originally undertaken as a comparison study to the amorphous alloys. Crystalline Co-Pt alloys have many striking similarities to the amorphous rare earth-transition metal alloys: perpendicular magnetic anisotropy, magneto-optic activity, and a {Tc} (for ...
Assessment of the immune system's capability to respond to antigens with the generation of specific antibodies, whilst under the influence of a test article, is required in toxicity tests according to the European guideline for repeated dose toxicity testing of medicinal products. The purpose of this study in rats was to validate methodology for the determination of Keyhole Limpet Haemocyanin (KLH)-specific antibodies under the influence of an immunologically active compound. The immunosuppressant FK506, commercially available as Prograf, was administered orally (gavage) to five rats per sex per group at dosages of 0.5mg/kg per day or 3mg/kg per day, for a period of 4 weeks. On days 14 and 22, KLH was administered subcutaneously, with an adjuvant (AluGel), to the two treated groups and a control (i.e. without FK506 treatment) approximately 1h following administration of FK506. Terminal investigations included haematology parameters, titration of KLH-specific antibodies in serum ...
Seasonal traffic on intercity corridors often creates severe congestion at various bottlenecks, such as land-drops and drawbridges. A Traffic Simulation And Optimization model (TSAO) has been developed in order to 1) evaluate traffic impacts (including travel time, vehicle operating costs, accidents, air pollution and fuel consumption) of a given routing pattern on a network, and 2) determine the optimal flow pattern. In its latest version, the TSAO model uses: 1) a macroscopic simulation approach to trace vehicle platoons through a network; 2) Greenshield's equation to represent volume-speed relationship on freeways and multi-lane highways, and Highway Capacity Manual method for two-lane rural highways; 3) Lighthill's shockwave function to simulate queue propagation; 4) event-scan time management for simulation; 5) variable link capacity for two-lane rural highways or to stimulate incidents; 6) AASHTO Guideline for determining vehicle operating ...
The symmetrical complexes [{sup 99m}Tc][TcN(R{sub 2}PS{sub 2}){sub 2}] [R = CH{sub 3}, CH{sub 2}CH{sub 3}, CH{sub 2}CH{sub 2}CH{sub 3}, CH{sub 2}(CH{sub 3}){sub 2}], and the unsymmetrical complex [{sup 99m}Tc][TcN(Me{sub 2}PS{sub 2})(Et{sub 2}PS{sub 2})] have been prepared, at tracer level, through a two-step procedure involving the preliminary formation of a prereduced technetium nitrido intermediate followed by substitution reaction onto this species by the appropriate dithiophosphinate ligand [R{sub 2}PS{sub 2}]Na. The chemical identity of the resulting complexes have been established by comparison with the corresponding {sup 99}Tc-analogs prepared, at macroscopic level, by reacting the complex [{sup 99}TcNCl{sub 4}] [n-Bu{sub 4}N] (n-Bu = n-butyl) with an excess of ligand in methanol, and characterized by elemental analyses and spectroscopic techniques. The complexes are neutral and lipophilic, and possess a square pyramidal geometry, with an apical Tc N group ...
The symmetrical complexes ["9"9"mTc][TcN(R_2PS_2)_2] [R = CH_3, CH_2CH_3, CH_2CH_2CH_3, CH_2(CH_3)_2], and the unsymmetrical complex ["9"9"mTc][TcN(Me_2PS_2)(Et_2PS_2)] have been prepared, at tracer level, through a two-step procedure involving the preliminary formation of a prereduced technetium nitrido intermediate followed by substitution reaction onto this species by the appropriate dithiophosphinate ligand [R_2PS_2]Na. The chemical identity of the resulting complexes have been established by comparison with the corresponding "9"9Tc-analogs prepared, at macroscopic level, by reacting the complex ["9"9TcNCl_4] [n-Bu_4N] (n-Bu = n-butyl) with an excess of ligand in methanol, and characterized by elemental analyses and spectroscopic techniques. The complexes are neutral and lipophilic, and possess a square pyramidal geometry, with an apical Tc N group and two dithiophosphinate ligands spanning the four positions on the basal plane through the four sulfur atoms of ...
The synthesis, characterization of M"vO([CH_3CH_2N(CH_2CH_2S)_2](p-S-Ph-COOCH_2-CH_3)) (M:"9"9"mTc: I, Re: II) is presented in this work, where a pendant ester function is attached to the monothiolate ligand. Chemical structure of I is established after chromatographic comparison with II, synthesized in macroscopic amounts. Complex II is fully characterized by classical methods of analysis showing that the compound adopts a distorted trigonal bipyramidal configuration around the metal. The two sulfur atoms of the tridentate ligand and the oxo group form the basal plane, while the remaining nitrogen atom of the tridentate ligand and the sulfur atom of the monothiolate ligand occupy the apices of the bipyramid. In vitro challenge experiments with glutathione (GSH) in neutral aqueous medium demonstrate, that I suffers nucleophilic attack by GSH and thereby transformation to a more hydrophilic daughter metal compound. Formation of the latter depends on time and GSH ...
Radiation hardening in austenitic stainless steels is shown to modify deformation characteristics and correlate well with an increased susceptibility to intergranular stress corrosion cracking (IGSCC). Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 to 2.5 x10"2"1 n/cm"2) for IGSCC are documented. In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlates better to yield strength than to fluence for most heats suggesting a possible role of radiation-induced hardening and microstructure on cracking. Microstructural evolution during proton and heavy-ion irradiation has been characterized in low-carbon 304SSs. Hardening results from a dispersion of dislocation loops in the matrix which increase in density and size with ...
Background: Malformations of cortical development vary in neuronal maturity and level of functioning. Purpose: To characterize regional relative cerebral blood volume (rCBV) and difference in first moment transit time (TTfm) in polymicrogyria and cortical tubers using magnetic resonance (MR) perfusion imaging. Material and Methods: MR imaging and dynamic T2*-weighted MR perfusion imaging were performed in 13 patients with tuberous sclerosis complex, 10 with polymicrogyria, and 18 controls with developmental delay but no macroscopic brain abnormality. Regions of interest were placed in cortical tubers or polymicrogyric cortex and in the contralateral normal-appearing side in patients with malformations. In 'control' subjects, regions of interest were placed in the frontal and parietal lobes in both hemispheres. The rCBV and TTfm of the tuber/contralateral side (rCBVRTSC and TTFMTSC) as well as those of the polymicrogyria/contralateral side (rCBVRPMG and TTFMPMG) ...
11-MeV neutrons were elastically and inelastically scattered from eight single-closed-shell nuclei: three proton-vibrational nuclei with N = 50 ("8"8Sr, "9"0Zr, "9"2Mo) and five even-even neutron-vibrational nuclei ("1"1"6"-"1"2"4Sn) with Z = 50. Detection methods involving electronic discrimination against #gamma# rays, and time-of-flight techniques were used to measure the energy of the scattered neutrons. Data were taken from 15"0 to 150"0 in 5"0 intervals. Measured differential cross sections were normalized to the zero-degree neutron flux and corrected. An optical model (OM) analysis was used to fit the elastic data with the code GENOA, and potential parameters were obtained for each nucleus. The observed low-lying electric quadrupole (2"+) and octupole (3"-) states were collective in nature; the macroscopic or collective model for inelastic scattering was used to generate the differential cross-section angular distributions with the distorted wave method. The ...
Breakdowns occurring in rf accelerating structures will limit the ultimate performance of future linear colliders such as the Compact Linear Collider (CLIC). Because of the similarity of many aspects of dc and rf breakdown, a dc breakdown study is underway at CERN to better understand the vacuum breakdown mechanism in a simple setup. Measurements of the field enhancement factor ? show that the local breakdown field is constant and depends only on the electrode material. With copper electrodes, the local breakdown field is around 10.8GV/m, independent of the gap distance. The ? value characterizes the electrode surface state, and the next macroscopic breakdown field can be well predicted. In breakdown rate experiments, where a constant field is applied to the electrodes, clusters of consecutive breakdowns alternate with quiet periods. The occurrence and lengths of these clusters and quiet periods depend on the evolution of ?. The application of a high field can even ...
Nuclear material is either a product of technological processing of natural source material or it is entirely of anthropogenic origin. Consequently, nuclear material carries 'tool-marks' or 'fingerprints' of the process it was subjected to. Uranium fuels are examples of the first category, while plutonium belongs to the second category. The nature of these production processes is reflected in the elemental and isotopic composition of the material as well as in its microscopic and macroscopic appearance. All of these parameters can be determined using appropriate analytical techniques and they may result in important conclusions on the history and on the origin of the material. Therefore, they provide the most essential contribution to the prevention of future diversions of nuclear material from the same source. So far, essentially metallic impurities or light elements have been investigated for their potential in providing clues either on the type of process they ...
Modern high-resolution electron microscopy (HREM) instruments, which are capable of a point-to-point resolution of better than 0.2 nm, have allowed atomic-scale observations of a variety of internal interfaces. The application of the HREM technique to fcc model systems for the purpose of addressing a number of interface issues will be examined in this paper. Atomic structure observations for heterophase interfaces of metal/metal and metal/metal-oxide systems as well as HREM studies of grain boundaries in NiO and Au will be discussed with emphasis on generic structural features and the role of the interface plane. Comparisons between observed interface structures and atomistic computer modeling results have shown agreements for some interfaces, as well as certain differences in others. A number of structural features are common to both metal and oxide grain boundaries, as well as certain heterophase boundaries. Of particular importance in close-packed solids appears to be the tendency ...
We investigate the dynamics of an 11-dimensional homogeneous cosmological model. We assume that the t = const hypersurfaces are products of a 3-dimensional Bianchi type-IX space and a 7-dimensional torus. Most results of our investigation hold when the 7-dimensional torus is replaced by an m-dimensional torus T/sup m/. We show that for a large class of vacuum solutions the physical space expands while the microspace contracts providing a natural mechanism of dimensional reduction. Matter satisfying a simple barotropic equation of state always breaks the process of dynamical dimensional reduction. With special attention we study the behavior of our model close to the initial singularity. In contrast with the 4-dimensional Bianchi type-IX cosmological model the Kasner solution always describes an approach to the initial singularity. We study the transition from the Kasner regime to the oscillatory regime. We show that matter does not significantly change this property. We have found some ...
We investigate the dynamics of an 11-dimensional homogeneous cosmological model. We assume that the t = const hypersurfaces are products of a 3-dimensional Bianchi type-IX space and a 7-dimensional torus. Most results of our investigation hold when the 7-dimensional torus is replaced by an m-dimensional torus T/sup m/. We show that for a large class of vacuum solutions the physical space expands while the microspace contracts providing a natural mechanism of dimensional reduction. Matter satisfying a simple barotropic equation of state always breaks the process of dynamical dimensional reduction. With special attention we study the behavior of our model close to the initial singularity. In contrast with the 4-dimensional Bianchi type-IX cosmological model the Kasner solution always describes an approach to the initial singularity. We study the transition from the Kasner regime to the oscillatory regime. We show that matter does not significantly change this property. We have found some ...
Objective: To assess dynamic MRI with Gd-DTPA enhancement for evaluating inflammatory changes in the subacromial bursa. Design and patients: We detected the signal intensity changes in dynamic MRI of the subacromial bursa, and confirmed these macroscopically by arthroscopy and histologically. The signal intensity was measured using built-in software, and the enhancement ratio (E ratio) was calculated from dynamic MR images. In addition, as a parameter of the rate of the increase in the signal intensity from 0 to 80 s, the mean increase per second in the E ratio was obtained as the coefficient of enhancement (CE). The correlation was studied of the E ratio and CE with the arthroscopic findings (redness, villous formation, thickening and adhesion), and of the E ratio and CE with the histological findings (capillary proliferation, papillary hyperplasia, fibrosis and inflammatory cell infiltration) of the subacromial bursa. Of patients with shoulder pain, this study ...
A 12 m.y. record of large rhyolitic eruptions from the Coromandel (CVZ) and Taupo (TVZ) volcanic zones of New Zealand is contained in cores retrieved by Leg 181 of the Ocean Drilling Program. Site 1124, located 670 km from the TVZ, has a maximum of 134 macroscopic tephra layers with a total thickness of 13.18 m. These units, along with between 7 and 63 tephras from 3 other sites, were dated by a combination of magnetostratigraphy, biostratigraphy, isothermal plateau fission track determinations, and geochemical correlation with onshore tephra deposits. Additional time control for the last 3 m.y. came from an orbitally tuned, benthic, oxygen isotope profile for Site 1123. Results extend the incomplete terrestrial record of volcanism by placing the first major rhyolitic eruption in the CVZ at c. 12 Ma, c. 1.6-1 m.y. earlier than previously known. Tephras became thicker and more frequent from the late Miocene into the Quaternary - a trend that probably reflected (1) ...
The environment - external or internal degrees of freedom coupled to the object of interest - can, in effect, monitor some of its observables. As a result, the eigenstates of these observables decohere and behave like classical states. Continuous destruction of superpositions leads to the effective environment-induced superselection (einselection), which is beginning to be recognized as a key step in the transition from quantum to classical. We investigate it here in the context of quantum chaos. I show that the evolution of a chaotic macroscopic system is not just difficult to predict (requiring accuracy exponentially increasing with time) but quickly ceases to be deterministic in principle as a result of the Heisenberg uncertainty (which limits the available resolution). This happens after a time t{sub {Dirac_h}} which is only logarithmic in the Planck constant. For example, various components of the solar system are chaotic, with the Lyapunov timescales ranging ...
Nuclear Forensics is a key element in the response process which is initiated after detection of illicit nuclear or other radioactive material. Credible nuclear forensics relies on appropriate sampling procedures, on validated analytical methods and on thorough data analysis and interpretation. Nuclear forensics aims at providing clues on the history and the potential origin of the material. Elemental and isotopic composition of the material, as well as its macroscopic and microscopic appearance reflect the technological processes used for the fabrication of the material. The nuclear forensic analysis first of all results in measurement data. Through appropriate processing of these data information on the nature and the history of the material can be obtained. A number of data evaluation techniques serving this purpose are conceivable and have been applied. On the one side, statistical methods like principal component analysis (PCA) or classification and regression ...
Studies are made in this program to enhance our understanding of the role of 5f electrons in chemical bonding. Most of our studies on the macroscopic scale emphasize certain isotopes available from the National Transplutonium Production Program centered at HFIR/TRU -namely, _9_6"2"4"8Cm, _9_7"2"4"9Bk, _9_8"2"4"9Cf, _9_9"2"5"3Es, and _9_9"2"5"4Es. Particular classes of compounds, such as hydrides, chalcogenides, and pnictides are often selected for study on the basis of their utility in bringing out significant chemical differences between the lanthanides and the actinides. High temperature/high pressure experiments on actinide metals and compounds reveal characteristics about the degree of 5f electron localization as a function of atomic number in the series. Magnetic properties of metals and compounds are investigated using ultra-sensitive methods and hydration numbers of ions in solution are investigated by neutron scattering at HFIR. As a result of a recently ...
Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were planned to theoretically ...
In the fields of medical imaging, geophysical well logging, and industrial radiography, it is often of interest to characterize the spatially distributed sensitivities of neutron and gamma-ray measurement devices to the physical properties of the materials being examined. For instance, one may wish to know how the count rate in a detector varies in response to small changes in the local density of the irradiated object as a function of position. Experimental determination of such sensitivity functions is often impractical. Consequently, we have developed a general three-dimensional Monte Carlo numerical technique that allows us to directly compute the differential sensitivity of an arbitrary integral response parameter, such as a time- or energy-discriminated count rate, with respect to the spatial distribution of macroscopic cross sections and sources in the irradiated medium. Sensitivities to object density, porosity, etc., can easily be derived from these ...
The antiviral drug combination consisting of arbidol and acetaminophen was investigated for its 4-week repeated oral administration in Sprague-Dawley rats. Groups of rats (10/sex in low-dose group, 15/sex in other three groups) were given at doses of 0, 200, 400, and 800 mg/kg/day. Clinical signs, mortality, body weight, food consumption, hematology, clinical biochemistry, macroscopic findings, organ weights, and histopathology were examined. The administration resulted in increased incidence of piloerection in most of the high-dose females and in some of the high-dose males and mid-dose females. Histopathological examinations revealed minor treatment-related change in the stomach of the high-dose animals. A decrease in body-weight gains and an increase in liver weight were observed in the mid- and high-dose groups. These treatment-related effects were reversible at the 2-week recovery period. A number of other clinical and pathological findings were not considered ...
The experimental study on #beta#-delayed proton decays near the proton drip line published by our group over the last 8 years were reviewed and summarized briefly, including first observation of 9 precursors in the rare-earth region and new measurements of 5 nuclei in the mass-90 region near N-Z line with the aid of the 'p-#gamma#' coincidence in combination with a He-jet tape transport system. Systematically comparing the experimental data with the current nuclear-model predictions, following points were represented. (1) the experimental half-lives for "8"5Mo and "9"2Rh as well as the predicted 'waiting point' nuclei "8"9Ru and "9"3Pd are 5-10 times longer than the macroscopic-microscopic model predictions given by Moeller et al. It considerably influences the prediction of mass abundances of the nuclides produced in rp-process. (2) The current-model predictions are not consistent with the experimental spin-parity assignments of the proton drip-line nuclei ...
We briefly reviewed and summarized the experimental study on #beta#-delayed proton decays published by our group over the last 8 years, namely the experimental observation of #beta#-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N#approx#Z by utilizing the p-#gamma# coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for "8"5Mo, "9"2Rh, as well as the predicted 'waiting point' nuclei "8"9Ru and "9"3Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moeller et al. [At. Data Nucl. Data Tables 66,131(1997)]. These data considerably influenced the predictions of the mass abundances of the ...
BackgroundSelection programs for growth and stress traits in cultured fish are fundamental to the improvement of aquaculture production. The gilthead sea bream (Sparus aurata)...Full Text Available
BackgroundDiabetic macular edema (DME) is one of the manifestations of diabetic retinopathy leading to loss of central vision and visual acuity. It manifests itself with swelling...Full Text Available
During organogenesis, net growth of tissues is determined by a balance between proliferation, hypertrophy, and apoptotic death. Human fetal bladder outflow obstruction is a major cause of end-stage...Full Text Available
Vascular permeability factor (VPF) is an Mr 40-kD protein that has been purified from the conditioned medium of guinea pig line 10 tumor cells grown in vitro, and increases fluid permeability from blood...Full Text Available
During germination and early growth of castor bean (Ricinus communis), all cellular constituents of the endosperm are eventually transferred to the growing embryo. The present results...Full Text Available
Thoracic aortic aneurysms (TAAs) are potentially devastating, and due to their asymptomatic behavior, pose a serious health risk characterized by the lack of medical treatment options and high...Full Text Available
Nerve growth factor (NGF), a survival factor for neurons enforces pain by sensitizing nociceptors. Also in the pancreas, NGF was associated with pain and it can stimulate the proliferation of pancreatic cancer cells. Hepatic stellate cells (HSC) respond to NGF with apoptosis. Transforming growth factor (TGF)-b, one of the strongest pro-fibrogenic activators of pancreatic stellate cells (PSC) induced NGF and its two receptors in an immortalized human cell line (ihPSC) and primary rat PSC (prPSC) as determined by RT-PCR, western blot, and immunofluorescence. In contrast to HSC, PSC expressed both NGF receptors, although p75NTR expression was weak in prPSC. In contrast to ihPSC TGF-b activated both Smad signaling cascades in prPSC. NGF secretion was diminished by the activin-like kinase (ALK)...
BackgroundPerichondrium is recognized as a tissue with chondrogenic potential yielding cells which can be used for osteochondral repair. Factors which influence the proliferative...Full Text Available
Strong inhibitory effects of the anionic surfactant linear alkylbenzene sulfonate (LAS) on four strains of autotrophic ammonia-oxidizing bacteria (AOB) are reported. Two Nitrosospira...Full Text Available
We carried out theoretical analyses based on ab initio calculations incorporates in which free energy of the vapor phase is incorporated in order to determine the initial growth kinetics of c-GaN on GaN(001)-(4x1). The feasibility of the theoretical approach had been confirmed by calculations of Ga adsorption-desorption transition temperature and transition beam equivalent pressures on the GaAs(001)-(4x2)b2 surface in our previous work [Y. Kangawa, T. Ito, A. Taguchi, K. Shiraishi, T. Ohachi, Surf. Sci. 493 (2001) 178]. The results of calculations suggest that no Ga adsorption occurs on the initial surface under typical growth conditions but that a Ga adsorption site appears after N adsorption on GaN(001)-(4x1). That is, in the initial growth stage of c-GaN on GaN(001)-(4x1), a N-adsorbed ...
The kinetics of calcium sulfate crystal growth is of importance in various fields, such as geochemistry, desalination technology, petroleum industry, and water and wastewater treatment. The seeded crystal growth rate of calcium sulfate dihydrate was measured as a function of supersaturation in NaCl electrolyte solutions from 0 to 6 m at temperatures of 25, 50, 70, and 90 C. The growth followed a second-order parabolic rate law with activation energies greater than 53 kJ/mol which suggested the surface reaction as the rate-limiting step. It was observed that the rate constant and the activation energy are solution composition dependent. The rate constant increases with NaCl concentration up to 3 molal and then begins to fall slightly. The activation energy dropped from 61 kJ/mol in the pure Ca-SO[sub 4]H[sub 2]O system to 53 kJ/mol in 3.0 m NaCl solutions. The electrolyte effect was similar to the crystal solubility behavior ...
DNA double-strand breaks (DSBs) and other lesions occur frequently during cell growth and in meiosis. These are often repaired by homologous recombination (HR). HR may result in the formation of DNA...Full Text Available
The rolB gene of Agrobacterium rhizogenes, whose expression stimulates the formation of roots by transformed plant tissues and other growth alterations in transgenic plants, codes for a beta-glucosidase...Full Text Available
The rolC gene of Agrobacterium rhizogenes, which drastically affects growth and development of transgenic plants, codes for a cytokinin-beta-glucosidase. Indeed, rolC protein expressed in Escherichia...Full Text Available
Strategies to combine aspirated marrow cells with scaffolds to treat connective tissue defects are gaining increasing clinical attention and use. In situations such as large defects where initial...Full Text Available
The target of rapamycin (TOR) pathway regulates cell growth and aging in various organisms. In Saccharomyces cerevisiae, silent information regulator 2 (Sir2) modulates cellular senescence. Moreover,...Full Text Available
Thyroid hormone is a critical regulator of growth, development and metabolism in virtually all tissues, and altered thyroid status affects many organs and systems. Although for many years testis...Full Text Available
During reproduction in flowering plants, pollen grains form a tube that grows in a polarized fashion through the female tissues to eventually fertilize the egg cell. These highly polarized pollen tubes...Full Text Available
The RNA-binding protein Hfq is recognized as an important regulatory factor in a variety of cellular processes, including stress resistance and pathogenesis. Hfq has been shown in several bacteria to...Full Text Available
Cellular polarity is a fundamental property of every cell. Due to their extremely fast growth rate (≥1 μm/s) and their highly elongated form, filamentous fungi represent a prime example...Full Text Available
Previous studies have shown that salicylates and protein-calorie malnutrition independently compromise maturation and growth of infants. In the present study, pregnant rats were fed normal-and low-protein...Full Text Available
Allen's Rule documents a century-old biological observation that strong positive correlations exist among latitude, ambient temperature, and limb length in mammals. Although genetic selection for thermoregulatory...Full Text Available
The role of IGF-I in the negative regulation of GH expression and release is demonstrated by in vitro and in vivo models; however, the targets and mechanisms of IGF-I...Full Text Available
ObjectivesObjectives Not AvailableDescriptionA collaborative study of the anaerobic treatment of wastes containing recalcitrant and inhibitory compounds using the SERC Anaerobic facility, in particular biomass structure, monitoring and control, catabolism and toxicity, pre-acidification and microbial growth and mesophilic and thermophilic lignocellulose degradation.~%~
We have identified the nonreceptor tyrosine kinase syk as a marker of differentiation/tumor suppressor in pancreatic ductal adenocarcinoma (PDAC). Syk expression is lost in poorly differentiated PDAC...Full Text Available
... in Ti-6Al-4V has been studied quite thoroughly [5-7], much of the work resulting from the Air Force-sponsored High Cycle Fatigue initiative [8]. In ...
An overview is provided of an evolving atomistic and kinetic model of semiconductor growth that unifies the main features of strain relaxation in low and high lattice misfit heteroepitaxy. The model reveals a kinetic pathway for dislocation formation during growth with little or no energy cost at low misfits, thus providing a way out of the longstanding dilemma of too high dislocation nucleation energies predicted by classical theories of the equilibrium behavior of a fixed number of particles at low misfits. The essential kinetic process underlying the model are identified on the basis of comparison of the predictions of kinetic Monte-Carlo simulations of growth with real-time or in-situ data obtained in such experiments as reflection high-energy electron diffraction (RHEED) and scanning probe microscopy (SPM). Relative significance of these atomistic kinetic processes is shown to naturally lead to strain relaxation via ...
BackgroundEsophageal squamous cell carcinoma (ESCC) is one of the most aggressive carcinomas of the gastrointestinal tract. We assessed the relevance of Slug in measuring the invasive...Full Text Available
It has become increasing clear that alterations in cellular metabolism have a key role in the generation and maintenance of cancer. Some of the metabolic changes can be attributed to the activation...Full Text Available
Human epidermal growth factor receptor 2 (HER2) is one of the most important prognostic and predictive factors for breast cancer patients. Recently, serum HER2...Full Text Available
Senescence of Grand Rapids leaf lettuce was greatly reduced at 3 storage temperatures by post-harvest treatment with N,N-dimethylaminosuccinamic acid (Alar) and 2-chloroethyltrimethylammonium chloride...Full Text Available
BackgroundLarge population growth surveys of children and adolescents aged 6 to 18 y were undertaken in Hong Kong in 1963 and 1993. The global epidemic of obesity is a major public...Full Text Available
The ruminal selenomonad strain H18 grew rapidly (mu = 0.50 h-1) in a defined medium containing glucose, ammonia, purified amino acids, and sodium (95 mM); little if any ammonia was utilized as a nitrogen...Full Text Available
MicroRNAs (miRs) can regulate many cellular functions, but their roles in regulating responses of vascular endothelial cells (ECs) to mechanical stimuli remain unexplored. We hypothesize that the physiological...Full Text Available
The Neurofibromatosis-2 (NF2) tumor suppressor merlin negatively regulates cell proliferation in numerous cell types. We have previously shown that the NF2...Full Text Available
Most genetic changes that promote tumorigenesis involve dysregulation of G1 cell cycle progression. A key regulatory site in G1 is a growth factor–dependent restriction point (R) where cells...Full Text Available
Accumulation of certain nonmetabolizable sugar-phosphates (including α-methyl glucoside-6-phosphate) in Escherichia coli is growth inhibitory and elicits the glucose-phosphate...Full Text Available
Although myo-inositol is included in media for the successful growth of plant tissues, the actual requirement of most tissues, including soybean (Glycine max) callus in suspension culture, for myo-inositol...Full Text Available
We examined the changes in the levels of indoleacetic acid (IAA), IAA esters, and a 22-kilodalton subunit auxin-binding protein (ABP1) in apical mesocotyl tissue of maize (Zea mays...Full Text Available
We have examined the association between cytokine, chemokine and growth factor concentrations with bacterial vaginosis (BV) in pregnant white and black women. A nested case-control analysis...Full Text Available
Emphasis was put on the comparative quantitative structure-activity approaches to the exploration of action mechanisms of structurally different classes of compounds showing the same type of activity...Full Text Available
The two-compartment radioassay for microbial kinetics based on continuous measurement of the {sup 14}CO{sub 2} released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial {sup 14}CO{sub 2} liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and ...
BACKGROUNDProtocadherin-PC (PCDH-PC) expression is upregulated in apoptosis-resistant sublines of the LNCaP human prostate cancer (CaP) cell line. Here, we assess...Full Text Available
BackgroundThe lactogenic hormones prolactin (PRL) and placental lactogens (PL) play central roles in reproduction and mammary development. Their actions are mediated via binding...Full Text Available
Cervical cancer is known to metastasize primarily by the lymphatic system. Dissemination through lymphatic vessels represents an early step in regional tumor progression, and the presence of lymphatic...Full Text Available
A Monascus pilosus strain was selected for production of intracellular α-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Galactose...Full Text Available
Interleukin 2 (IL-2) and B-cell growth factors I and II (BCGF I and BCGF II) are lymphokines produced by T cells that play a major role in T- and B-cell cooperation. Peripheral blood lymphocytes from...Full Text Available
During a study of the health status of children in rural Nigerian communities a gross lack of fit was observed between the sample and the growth attainment standards derived from local longitudinal...Full Text Available
The acetogenic bacterium Clostridium thermoaceticum ATCC 39073 grew at the expense of the two-carbon substrates oxalate and glyoxylate. Other two-carbon substrates (acetaldehyde, acetate,...Full Text Available
Cells of oat coleoptiles (Avena sativa L. cv. “Garry”) have been osmotically shocked in order to observe the effect of alterations of the plasma membrane on some auxin...Full Text Available
DescriptionThe UK horticulture and agriculture industries rely on large inputs of mineral nitrogen (N), phosphorus (P) and potassium (K) fertilisers to maintain product yield and quality. Recovery of applied fertilisers by field crops is inefficient (routinely
BackgroundDysregulation of the insulin-like growth factor (IGF) system, a common consequence of adiposity-induced insulin resistance, may be a key underlying mechanism...Full Text Available
Increased oxidative stress is associated with perinatal asphyxia and respiratory distress in the newborn period. Induction of nuclear factor erythroid 2 p45-related factor (Nrf2) has been shown to decrease...Full Text Available
Nickel was established as an essential micronutrient for the growth of temperate cereal crops. Grain from barley (Hordeum vulgare L. cv `Onda'; containing 40 to 80 nanograms of Ni per...Full Text Available
Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate...Full Text Available
Male transgenic mice expressing the polyomavirus middle T (PyV-MT) gene exhibited growth and developmental abnormalities in prostatic and other urogenital epithelium. Expression of PyV-MT was directed...Full Text Available
BackgroundIn rats, alcohol exposure during the period of rapid brain growth produces long-term changes in the free-running period, photoentrainment and phase-shifting...Full Text Available
A film of GaSb grown epitaxially on a Si substrate is a direct transition semiconductor useful for application as a light source in Si photonics and channel material in next-generation field effect transistors because its energy bandgap is close to the optical fibre communication wavelength and it possesses high carrier mobility. Here, we report a novel method for heteroepitaxial growth of high-quality GaSb/Si films, despite having a lattice mismatch as large as ? 12%, using elastically strain-relaxed GaSb nanodots with ultrahigh density as seed crystals for film growth. The nanodot seed crystals were grown epitaxially by restricted contact with the Si substrate through nanowindows in an ultrathin SiO(2) film on the Si substrate. A light-emitting diode containing GaSb/Si films with a thickness of ? 90 nm fabricated by this method operated at room temperature. The growth method was also used to fabricate AlGaSb films of high ...
The production of Alternaria alternata f. sp. lycopersici host-specific toxins (AAL toxins) and epoxide hydrolase (EH) activity were studied during the growth of this...Full Text Available
Microorganisms in the environment can often adapt to use xenobiotic chemicals as novel growth and energy substrates. Specialized enzyme systems and metabolic pathways for the degradation of man-made...Full Text Available
Aluminium (Al) toxicity, affecting around half of the world¿s arable land, severely hinders the ability of crop plants to utilize moisture and nutrients by restricting root growth and function. Among the cultivated cereals, rye is the most Al-tolerant and represents an important potential source of ...
Bacterial processes in soil, including biodegradation, require contact between bacteria and substrates. Knowledge of the three-dimensional spatial distribution of bacteria at the microscale is necessary...Full Text Available
The hair follicle cycle successively goes through the anagen, catagen, telogen, and latency phases, which correspond, respectively, to hair growth, arrest, shedding, and absence before a new anagen...Full Text Available
When 2,2-dimethyl 3-(2'-naphthyl 6'-hydroxy) pentanoic acid, an artificial estrogen of the allenolic acid group, was added to an exponential-phase growth culture of Neurospora crassa (in Horowitz medium),...Full Text Available
BackgroundThe tumor microenvironment has been described as a critical milieu determining tumor growth and metastases. A pivotal role of metastasis-inducing S100A4 in the development...Full Text Available
The formation of mammalian secondary palate requires a series of developmental events such as growth, elevation and fusion. Despite recent advances in the field of palate development, the process...Full Text Available
There has been great interest in understanding the methods by which collagen-based load-bearing tissue is constructed, grown and maintained in vertebrate animals. To date, the responsibility for this...Full Text Available
End binding proteins (EBs) are highly conserved core components of microtubule plus-end tracking protein networks. Here we investigated the roles of the three mammalian EBs in controlling microtubule...Full Text Available
BackgroundThe epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand...Full Text Available
Mammals possess multiple insulin-like growth factor (IGF) binding proteins (IGFBPs), and related proteins, that modulate the activity of insulin/IGF signalling (IIS), a conserved neuroendocrine signalling...Full Text Available
ObjectivesThe main objective of this study is to address the following specific questions: 1. Are the delayed effects of poor early diet on whole organism performance and senescence contingent on, or exacerbated by, the subsequent occurrence of compensatory growth? 2. Does the rate of growth influence levels of resting metabolism and/or oxidative stress, and if so, for how long does this persist? 3. How are the levels of early nutrition, growth, resting metabolism and oxidative stress linked to the lev [continued...]DescriptionIt is now widely appreciated that, while animals may appear to recover from periods of poor food quality or quantity experienced in early development, adverse effects may occur later in adult life. Such effects can influence the performance of complete cohorts of animals, and have important consequences for population dynamics. The reasons why such delayed effects occur across the animals' lifetimes ...
Sibling Paenibacillus dendritiformis bacterial colonies grown on low-nutrient agar medium mutually inhibit growth through secretion of a lethal factor. Analysis of secretions reveals...Full Text Available
A Legionella-like organism (strain 1087-AZ-H) was isolated from a pleural-fluid specimen from a renal transplant patient undergoing immunosuppressive therapy. Growth characteristics and gas-liquid chromatography...Full Text Available
A Legionella-like organism, strain 1677-MI-H, was isolated from the bronchoscopy washings of a patient with pneumonia who had a 2-year history of progressive, chronic lymphocytic leukemia. The growth...Full Text Available
New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission...Full Text Available
Kin form important political groups, which change in size and relative inequality with demographic shifts. Increases in the rate of population growth increase the size of kin groups but decrease their...Full Text Available
Large population sizes, rapid growth and 3.8 billion years of evolution firmly establish microorganisms as a major source of the planet's biological and genetic diversity. However, up to 99% of the...Full Text Available
The inhibitory effects of indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) on elongation growth of pea (Pisum sativum L.) seedling roots were investigated...Full Text Available
African trypanosomes exert significant morbidity and mortality in man and livestock. Only a few drugs are available for the treatment of trypanosome infections and therefore, the development of new...Full Text Available
Auxin autonomous growth of most crown gall tumor cells requires the expression of two auxin biosynthesizing genes (tms 1 and tms 2) from the T-DNA of Agrobacterium...Full Text Available
Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype...Full Text Available
Purpose: Understanding the kinetics of tumor growth∕shrinkage represents a critical step in quantitative assessment of therapeutics and realization of adaptive radiation therapy....Full Text Available
Neuropilin-1 (NRP1) acts as a co-receptor for class 3 semaphorins and vascular endothelial growth factor and is an attractive angiogenesis target for cancer therapy. In addition to the transmembrane...Full Text Available
Skeletal formation is an essential and intricately regulated part of vertebrate development. Humans and mice deficient in Growth and Differentiation Factor 6 (Gdf6) have numerous...Full Text Available
Cellular hypertrophy is regulated by coordinated pro- and antigrowth machineries. Foxo transcription factors initiate an atrophy-related gene program to counter hypertrophic growth. This study was designed...Full Text Available
In chemostat culture, the virulence of two strains of Legionella pneumophila was shown to be significantly (P < 0.05) reduced when the culture temperature was lowered from 37 to 24 degrees C....Full Text Available
Increasing salinity has the potential to affect freshwater organisms. Yet sub-lethal effects of salinity on macroinvertebrates are poorly understood. Growth and development of Ischnura heterosticta (Odonata: Coenagrionidae) was experimentally shown to be faster in 5-20 mS/cm than 0.1-1 mS/cm, while in 35 mS/cm all individuals died. In 30 mS/cm about half died and growth was similar to the 0.1 mS/cm treatment. The salinity-growth relationship cannot be explained indirectly, that is salinity affecting the survival of their prey. Tissue content and concentration of Ca, Mg, Na and K in emerged adults showed no evidence of deficiencies at low salinity. Heart beat rate was similar across treatments, except at 35 mS/cm, where it was slower. Respiration and feeding were similar at 0.1, 10 and 30 mS/cm. While there are similarities in I. heterosticta and other species' salinity response, there are differences and studies on more ...
A Staphylococcus strain was inoculated on the top and cut surfaces of freshly baked Southern custard pies which were then packaged in a pasteboard carton and held at 30 C. Daily plate...Full Text Available
Our increasing capabilities for quantitative hormone analysis and automated high resolution growth studies have allowed a reassessment of the classical Cholodny-Went hypothesis of gravitropism. According...Full Text Available
Neonatal administration of the synthetic glucocorticoid, dexamethasone (DEX) retards brain growth, alters adult behaviors and induces cell death in the rat brain, thereby implicating glucocorticoids...Full Text Available
This article examines the effects of competition of geothermal energy production with other technologies. The topics of the article include near-term market growth, cause for cautious optimism, limits to development of geothermal energy production, economic arguments for development of geothermal power plants, the effects of a competitive market on industry survival.
Harmful algal blooms, caused by rapid growth and accumulation of certain microalgae in the ocean, pose considerable impacts on marine environments, aquatic industries and even public health. Here, we...Full Text Available
Zinc is an essential trace metal ion for growth, but an excess of Zn is toxic and microorganisms express diverse resistance mechanisms. To understand global bacterial responses to excess Zn, we conducted...Full Text Available
Francisella tularensis requires iron (Fe) for growth, but the biologic sources of Fe for this organism are largely unknown. We found that Francisella sp. growing in...Full Text Available
We report here a study of the mechanisms leading to loss of growth control in chicken embryo fibroblasts transformed by Rous sarcoma virus (RSV). We have been particularly concerned with the role of the src gene in this process, and have used RSV mutants temperature sensitive (ts) for transformation to investigate the nature of the growth regulatory lesion. The two principal findings were (1) the stationary phase of the cell cycle (G{sub 1}) in chick embryo fibroblasts seems to have two distinct regulatory compartments (using the terminology of Brooks et al. we refer to these as 'Q' and 'A' states). When rendered stationary at 41.5 C by serum deprivation, normal cells enter a Q state, but cells infected with the ts-mutant occupy an A state. (2) Whereas normal cells can occupy either state depending on culture conditions, the ts-infected cells, at 41.5 C, do not seem to enter Q even though a known src gene ...
The structural features required for xyloglucan oligosaccharides to inhibit 2,4-dichlorophenoxyacetic acid-stimulated elongation of pea stem segments have been investigated. A nonasaccharide (XG9)...Full Text Available
A monensin-sensitive ruminal peptostreptococcus was able to grow rapidly (growth rate of 0.5/h) on an enzymatic hydrolysate of casein, but less than 23% of the amino acid nitrogen was ever utilized....Full Text Available
Forest research on fast growing Eucalyptus hybrids in the Congo, using coppice shoots for propagation, is described. The hybrids can grow 20 ft in 15 months and it is suggested that the application of such methods in Britain may increase the growth rates of hardwoods such as oak or walnut.
All eukaryotes require mitochondria for survival and growth. The origin of mitochondria can be traced down to a single endosymbiotic event between two probably prokaryotic organisms. Subsequent evolution...Full Text Available
The dissimilatory iron-reducing bacterium Geobacter metallireducens was found to require iron at a concentration in excess of 50 μM for continuous cultivation on nitrate. Growth...Full Text Available
Zygotes of fucoid algae have long been studied as a paradigm for cell polarity. Polarity is established early in the first cell cycle and is then expressed as localized growth and invariant cell division....Full Text Available
Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate...Full Text Available
Enterococcus faecalis cells cannot synthesize porphyrins and do not rely on heme for growth but can take up heme and use it to synthesize heme proteins. We recently described a cytochrome...Full Text Available
Enrichment cultures were used to determine the conditions promoting fastest methanogenic propionate degradation and growth by adapting the cultures to various physical and chemical conditions and measuring...Full Text Available
One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infection (SSTI). Staphylococcus aureus, a common cause of SSTI, has generated increasing...Full Text Available
Intermetallic compound (IMC) growth at the interface between a Sn coating and a Cu substrate with or without a Ni underlayer and its related stress state was evaluated by real-time measurements using the flexure beam method. For the Sn coating without a Ni underlayer, pyramid-shaped IMC grains of Cu6Sn5 grew along the grain boundaries of Sn from the Cu substrate, especially at the triple grain boundary junctions and the IMC grains rapidly increased their volume during the initial 3?days, During this time, the IMC growth rate was 2.3??m3/day and the compressive stress in the Sn coating rapidly developed and became saturated at about ?11?MPa. In contrast, platelet IMC grains of Ni3Sn4 formed at the surface of the Ni underlayer and the IMCs grew at a rate of 1.0??m3/day for the Sn/Ni coating....
In support of a project on lifetime calculation experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K{sup Iscc}, and the crack growth rate were made to predict evolution of damage in tube walls. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that the material of SG tubes is sensitive to transgranular environmentally assisted cracking in the three basic concentrated environments used, alkaline, neutral and acid. The most corrosive medium was the acid ...
In support of a project on lifetime calculation experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K"I"s"c"c, and the crack growth rate were made to predict evolution of damage in tube walls. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that the material of SG tubes is sensitive to transgranular environmentally assisted cracking in the three basic concentrated environments used, alkaline, neutral and acid. The most corrosive medium was the acid ...
Background and AimsThe small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia,...Full Text Available
Methyl fluoride is frequently used to specifically inhibit acetoclastic methanogenesis, thus allowing determination of the relative contribution of acetate versus H2/CO2 to total...Full Text Available
Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, are responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. Because cortical bone exhibits rising crack-growth resistance with crack extension, unlike most previous studies the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the ex vivo crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; the initiation toughness decreases some 40% over six decades from 40 to 100 years, while the ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the causality results show that the relationship between income and ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO2) and sulfur dioxide (SO2) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO2 emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO2 emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to 1200 (constant 2000 prices) or to 3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the causality results show that the relationship between income and ...
Glioblastoma, the most common malignant brain tumor, is among the most lethal and difficult cancers to treat. Although epidermal growth factor receptor (EGFR) mutations are frequent in glioblastoma,...Full Text Available
Oocyte-cumulus cell bidirectional communication is essential for normal development of the oocyte and cumulus cells (CCs) within the follicle. We showed recently that addition of recombinant growth...Full Text Available
Genome endoreduplication during mammalian development is a rare event for which the mechanism is unknown. It first appears when fibroblast growth factor 4 (FGF4) deprivation induces differentiation...Full Text Available
Growth at increasing continuous irradiance (at high nutrient nitrate) and nutrient nitrate concentrations (at high continuous irradiance) furnished increases in the in vivo and in...Full Text Available
The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase in Drosophila melanogaster synthesizes mevalonate for the production of nonsterol isoprenoids, which are essential for growth and...Full Text Available
In rats, damage to neuronal populations in some brain regions occurs in response to neonatal alcohol exposure coinciding with the period of rapid brain growth. These alcohol-induced defects...Full Text Available
Transitions at 28-32°C in membranes of many kinds of seeds influence their germination and subsequent growth. Changes at 28-32°C in the rates of loss of endogenous amino acids from imbibed...Full Text Available
OBJECTIVEPhosphoinositide 3-kinase enhancer A (PIKE-A) is a proto-oncogene that promotes tumor growth and transformation by enhancing Akt activity. However, the physiological functions...Full Text Available
Proteins that metabolize or bind the nucleotide second messenger cyclic diguanylate regulate a wide variety of important processes in bacteria. These processes include motility, biofilm formation, cell...Full Text Available
The sale of consumer products over the Internet has grown rapidly, including the sale of drugs. While the growth in online drug sales by reputable pharmacies is a trend that may provide benefits to...Full Text Available
Activation of beta-adrenergic or muscarinic acetylcholine receptors expressed in transfected cells or epidermal growth factor receptors in human keratinocytes produces 15% to 200% changes in cellular...Full Text Available
A series of lab and greenhouse studies were undertaken to understand how Cu and Zn toxicity influences Bromus carinatus (Hook and Arn.) growth, to what degree an organic amendment (yard waste compost) may reduce Cu and Zn bioavailability in Cu-Zn minespoil and promote plant growth in combination with fertilizer, and how the vertical distribution of compost in the minespoil influences rooting depth. Root Cu and Zn toxicity thresholds were determined to be 1 mg L"-"1 and 10 mg L"-"1 in solution, respectively. The compost amendment had exceptionally high Cu and Zn binding capacities (0.17 and 0.08 g metal g C"-"1, for Cu and Zn, respectively) that were attributed to high compost humic and fulvic acid concentrations. Maximum plant biomass was achieved when minespoil was amended with compost and fertilizer in combination. Fertilizer alone had no effect on plant growth. Mixing compost into the minespoil was essential to promote ...
The overarching goal of medical training is to nurture the growth of knowledgeable, caring and insightful clinicians guided by the ideals of medical professionalism. Recent definitions of professional...Full Text Available
The opportunistic pathogenic yeast Candida albicans exhibits growth phase-dependent changes in cell surface hydrophobicity, which has been correlated with adhesion to host tissues....Full Text Available
The photosynthetic activity of the green alga Scenedesmus quadricauda was investigated during synchronous growth in light/dark cycles. The rate of O2 evolution increased...Full Text Available
BackgroundAchieving sustainable economic and social growth through advances in health is crucial in Latin America within the framework of the United Nations Millennium Development...Full Text Available
Excess caveolin-1 has been reported to play a role in age-dependent hyporesponsiveness to growth factors in vitro. Therefore, we hypothesized that caveolin-1–dependent hyporesponsiveness...Full Text Available
BackgroundComplementary feeding is currently recommended after six months of age, when the nutrients in breast milk alone are no longer adequate to support growth. Few studies have...Full Text Available
Brownfields redevelopment contributes to the revitalization of communities across the U.S. Reuse of these abandoned, contaminated sites spurs economic growth, builds community pride, protects public health, and helps maintain our nation's "greenfields," often at a relatively low ...
BackgroundCancer stem cells (CSCs) have increased resistance to cancer chemotherapy. They can be enriched as drug-surviving CSCs (D-CSCs) by growth with chemotherapeutic drugs, and/or...Full Text Available
The protein kinase CK2 (formerly casein kinase II) is thought to be involved in light-regulated gene expression in plants because...Full Text Available
Functionalizing of single molecules on surfaces has manifested great potential for bottom-up construction of complex devices on a molecular scale. We discuss the growth mechanism for the initial layers...Full Text Available
Aerobacter cloacae UW-C83 and Escherichia coli K-12 were grown under various anaerobic environments. Yatp values were calculated by determination...Full Text Available
Experimental data are reported on the micro-irregularities of resistivity in longitudinal and transverse specimens of germanium 0.5 to 0.8 mm in thickness and 25 to 40 mm in width. These data are correlated with the conditions of growth of the crystals. (16 refs).
BackgroundObtaining single parasite clones is required for many techniques in malaria research. Cloning by limiting dilution using microscopy-based assessment for parasite growth...Full Text Available
Forty children with the fetal alcohol syndrome were identified in the west of Scotland. All were growth retarded and had abnormal facial features, and all those who were tested were found to have neurological...Full Text Available
A p[sup +]-Al[sub 0.3]Ga[sub 0.7]As/n[sup +]-GaAs heterojunction tunnel diode was fabricated using Atomic Layer Epitaxy (ALE) growth technique. Background carbon doping of [similar to]10[sup 20] cm[sup [minus]3] was achieved in the p-side of the diode by optimizing growth conditions such as V/III ratio, exposure times to reactant gases, and growth temperature. In the n-side of the diode GaAs was doped with silane and doping concentrations as high as 7[times]10[sup 18] cm[sup [minus]3] were also achieved. The dopants are chosen to satisfy the high levels and low diffusion requirements. The diode can be used to interconnect the high and low band-gap cells in the AlGaAs/GaAs cascade solar cell structure. The reactor used in this investigation is a commercial MOCVD system which has been specially modified for dual operation of ALE and MOCVD growth modes.
The relationships between basic and applied agricultural R&D, developed and developing country R&D and between R&D, extension, technology and productivity growth are outlined....Full Text Available
Low concentrations of sugars altered the sensitivity of seed germination to inhibition by exogenous abscisic acid (ABA). Germination of wild-type and ABA-insensitive (abi) Arabidopsis...Full Text Available
BackgroundPregnancies complicated by abnormal umbilical artery Doppler blood flow patterns often result in the baby being born both preterm and growth-restricted. These babies are...Full Text Available
Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is...Full Text Available
A generalized Fisher equation (GFE) relates the time derivative of the average of the intrinsic rate of growth to its variance. The GFE is an exact mathematical result that has been widely used in population...Full Text Available
We show that the expression of an indole-3-acetic acid (IAA)-modified protein from bean seed, IAP1, is correlated to the developmental period of rapid growth during seed development. Moreover, this...Full Text Available
A comparative study has been carried out of the growth of two lines of Datura innoxia (Mill.) cells, designated DI-6 and NR1, their resistance to chlorate, and their ability to assimilate...Full Text Available