bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure broadening and fine-structure-dependent predissociation in oxygen BΣu−3, v=
Authors: Hannemann Sandro , Wu GuoRong , van Duijn Eric-Jan , Ubachs Wim , Cosby Philip C.
Published: November 2005

Both laser-induced fluorescence and cavity ring-down spectral observations were made in the Schumann-Runge band system of oxygen, using a novel-type ultranarrow deep-UV pulsed laser source. From measurements on the very weak (0,0) band pressure broadening, pressure shift, and predissociation line-broadening parameters were determined for the BΣu−3, v=0,Fi fine-structure components for various rotational levels in O2. The information content from these studies was combined with that of entirely independent measurements probing the much stronger (0,10), (0,19), and (0,20) Schumann-Runge bands involving preparation of vibrationally excited O2 molecules via photolysis of ozone. The investigations result in a consistent set of predissociation widths for the BΣu−3, v=0 state of oxygen.
Ab initioelectron propagator theory of molecular wires: I. Formalism
Authors: Dahnovsky Yu. , Zakrzewski V. G. , Kletsov A. , Ortiz J. V.
Published: November 2005

Ab initio electron propagator methodology may be applied to the calculation of electrical current through a molecular wire. A new theoretical approach is developed for the calculation of the retarded and advanced Green functions in terms of the electron propagator matrix for the bridge molecule. The calculation of the current requires integration in a complex half plane for a trace that involves terminal and Green’s-function matrices. Because the Green’s-function matrices have complex poles represented by matrices, a special scheme is developed to express these “matrix poles” in terms of ordinary poles. An expression for the current is derived for a terminal matrix of arbitrary rank. For a single terminal orbital, the analytical expression for the current is given in terms of pole strengths, poles, and terminal matrix elements of the electron propagator. It is shown that Dyson orbitals with high pole strengths and overlaps with terminal orbitals are most responsible for the conduction of electrical current.
Thermal inequilibrium of atmospheric helium microwave plasma produced by an axial injection torch
Authors: Álvarez R. , Rodero A. , Quintero M. C. , Sola A. , Gamero A. , Ortega D.
Published: November 2005

The population density of several excited states has been obtained spectroscopically in a helium plasma sustained by a torch device at atmospheric pressure as a function of the radius in the plasma for different conditions of microwave power and plasma gas flow. The ground-state atom density is determined from the gas temperature, which is deduced from the rotational temperature of the molecular nitrogen ions. The population distribution is fitted to the theoretical results of a collisional-radiative model that includes particle transport. A large deviation of the measured populations is found from the theoretical populations for local thermodynamic equilibrium. The plasma at any radial position is far from local thermodynamic equilibrium; the equilibrium deviation parameter of the ground state is larger than 10 000. The equilibrium deviation parameters of the measured excited-state populations obey the theoretical pk−6 exponential law.
Effect of wall reflection on the determination of electron temperature by the line-ratio method in inductively coupled plasmas
Authors: Pu Yi-Kang , Yu Zhen-Dong , Guo Zhi-Gang
Published: November 2005

The light collected from inductively coupled CH4∕N2 and N2 plasmas is strongly affected by wall reflection. Since wall reflectivity varies with wavelength, the effect can lead to a significant error in the electron temperature determined by the line-ratio method.
Local effects of St∼O(1) on small particle motion in a linear flow field
Authors: Mograbi E. , Bar-Ziv E.
Published: November 2005

Small particle motion in a linearized flow field is investigated analytically. The aim is to study the effects of relatively large Stokes numbers (St). It is assumed that the only dominant hydrodynamic force is the quasisteady Stokes drag where all other effects are neglected. An exact solution for a general, three-dimensional, unsteady flow field, including gravity, is obtained. Emphasis is placed on the role taken by the spatially varying flow field and the particle inertia. Although an immediate consequence of the linearization is that the long-term particle velocity is insensitive to initial conditions, no matter the value of St, the short-term behavior is quite intriguing. This behavior is found to be highly sensitive to the initial particle velocity when St exceeds critical values depending on the flow; this happens, for example, in shear flows. The exponential approach of the particle velocity to the fluid velocity, predicted by the asymptotic solution for St∼o(1), may under certain flow conditions transform into damped oscillations for critical values of the St number. An explanation is provided by showing the equivalence of the particle equation to that of a damped pendulum.
Biosilicified structures for cooling plant leaves: A mechanism of highly efficient midinfrared thermal emission
Authors: Wang Lijun , Nie Qing , Li Min , Zhang Fusuo , Zhuang Jiaqi , Yang Wensheng , Li Tiejin , Wang Yunhua
Published: November 2005

Biosilicified structures fulfill a variety of crucial functions in biological systems. Here, we present a detailed study of leaf temperatures of silicified leaves of creeping bentgrass (Agrostis palustris) by thermal infrared imaging, and show that biosilicified structures deposited in epidermal cells of plant leaves reduce the heat load of leaves and are remarkably effective in cooling leaves by virtue of highly efficient midinfrared thermal emission (8–12μm) of plant silica. We conclude that biosilicified structures have potential as an environmentally benign practical approach for improving plant tolerance of high temperature.
Direct electron- and hole-spin relaxation measurements in undoped piezoelectric CdTe quantum wells
Authors: Soleimani H. Rahimpour , Cronenberger S. , Gallart M. , Gilliot P. , Cibert J. , Crégut O. , Hönerlage B. , Likforman J.-P.
Published: November 2005

Two heavy-hole exciton transitions sharing a common electronic energy level in the conduction band are used in a pump-probe transmission experiment to determine the spin relaxation time of both electrons and holes. In contrast with previous studies, we find that the hole spin relaxes more slowly than the electron spin.
Photocurrent spectroscopy under depletion mode of transparent polymer field-effect transistors
Authors: Dutta S. , Narayan K. S.
Published: November 2005

The unique combination of voltage and light as the controlling parameters for charge transport in polymer-based field-effect transistors (PFETs) offers interesting strategies for light detection. Results of gate-voltage (Vg)-controlled intensity-modulated spectral response of the drain current in optically transparent PFETs are reported. The measurement and analysis of the results, obtained from light incident from the top and bottom side of the device, provide spatial information of the Vg-dependent photocarrier generation region. These measurements serve as a direct measure of the extent of the depletion.
Sample holder for neutron scattering in high magnetic fields
Authors: Rotter M. , Rotter K. P. , Doerr M. , Schedler R. , Loewenhaupt M. , Schneidewind A. , Enderle M. , Schmidt W. , Svoboda P. , Vejpravova J.
Published: November 2005

A type of sample holder for neutron scattering experiments in high magnetic fields has been developed and tested, which is based on the fixation of the sample by a compressed powder of the cryostat material, in our case aluminum. It has been tested up to a field of 13 T in a measurement of the transversal magnetostriction of a PrCu2 single crystal.
Prolonged electron emission as a method to fabricate a stable and bright dual ion/electron point source
Authors: Hsieh Wen-Pin , Wang Y. L.
Published: November 2005

A method based on prolonged (few hundreds of hours) electron emission has been developed to fabricate a stable dual ion/electron source with an electron emission current as high as 5μA, which is ∼100 times higher than that of any dual source reported previously. Once fabricated, the dual emitter can be switched interchangeably between ion and electron emission mode within a few minutes after changing the polarity of the extraction electrode. The achievement of such a stable and bright dual ion/electron point emitter is an important step towards the further development of single-column focused ion/electron beam systems.
Activation of Na+ channels in cell membrane by capacitive stimulation with silicon chip
Authors: Schoen Ingmar , Fromherz Peter
Published: November 2005

Sodium channels are the crucial electrical elements of neuronal excitation. As a step toward hybrid neuron-semiconductor devices, we studied the activation of recombinant NaV1.4 sodium channels in human embryonic kidney (HEK293) cells by stimulation from an electrolyte/oxide/silicon (EOS) capacitor. HfO2 was used as an insulator to attain a high capacitance. An effective activation was achieved by decaying voltage ramps at constant intracellular voltage at a depleted NaCl concentration in the bath to enhance the resistance of the cell-chip contact. We were also able to open sodium channels at a NaCl concentration close to physiological conditions. This experiment provides a basis for noninvasive capacitive stimulation of nerve cells with semiconductor chips.
Near-field magneto-optical microscopy using surface-plasmon waves and the transverse magneto-optical Kerr effect
Authors: Wei Pei-Kuen , Chou Hsieh-Li , Cheng You-Ren , Yao Yung-Der
Published: November 2005

This research investigates the propagation behavior of the optical near field between gold-coated tapered fiber tips and magnetic thin films. From three-dimensional finite-difference time-domain calculations, we verified that p-polarized incident light generated a strong longitudinal electric field in the fiber tip. This longitudinal electric field can propagate in the nanogap with the aid of surface-plasmon waves. The surface-plasmon wave and the transverse magneto-optical Kerr effect were used in near-field microscopy to measure the magnetic images of submicron Ni–Fe dot arrays. Changes of magnetic domains under different external magnetic fields were experimentally verified by near-field magneto-optical microscopy.
Four-parameter equation of state of solids
Authors: Li J. H. , Liang S. H. , Guo H. B. , Liu B. X.
Published: November 2005

A four-parameter equation of state (EOS), expressed in terms of the equilibrium volume V0, cohesion energy EC, isothermal bulk modulus B0, and its first pressure derivative B0′, is proposed and successfully applied to 40 selected metals. From the proposed EOS, the thermal expansions α, melting points TM, ultimate strengths PC, and critical volume VC of the selected metals are calculated and are in good agreement with the experimental observations. Besides, a strong correlation between PC∕B0 and (VC−V0)∕V0 is found to be (PC∕B0)∕[(VC−V0)∕V0]≈0.31.
Magnetic and electrochemical studies on Ni2+-substituted Li–Mn spinel oxides
Authors: Nakamura Tatsuya , Yamada Yoshihiro , Tabuchi Mitsuharu
Published: November 2005

Li Mn 2 − x Ni x O 4 ( x < 0.5 ) cubic spinel oxide was synthesized by the sol-gel technique using Li-nitrate, Mn-acetate, and Ni-acetate salts. The gel precursors were decomposed at 300°C in air and then annealed at temperatures ranging from 500to850°C in an oxygen flow. For a fixed annealing temperature of 700°C, the lattice constant linearly decreased with an increase in the substitution degree x. As x increased, the low-temperature magnetization increased and the asymptotic Curie temperature moved in the positive direction and changed its sign from negative to positive around x=0.2. Additionally, the redox capacity of 4.7V plateau was increased at the expense of the capacity around 4.0V. When the x value was fixed at 0.5, all the specimens showed ferromagnetic magnetization. The minimum lattice parameter, the maximum Curie temperature, and the maximum magnetization were attained simultaneously for the specimen annealed at 700°C, which exhibited only a plateau around 4.7V. It was possible to explain these variations by considering the magnetic interactions between transition-metal ions.
Magnetic read-only memory with removable medium
Authors: Op’t Root W. P. E. M. , Swagten H. J. M. , Jedema F. J. , Kuiper A. E. T.
Published: November 2005

A solid-state memory concept is discussed, featuring a removable data carrier on which information is stored in a pattern of magnetic bits. The information is read out with a sensor array of magnetic tunnel junctions. The calculated readout signals of the sensors are compared with the measured values for a magnetic card with a data density of 0.5Mbyte∕cm2. The card-sensor separation is identified to determine the ultimate achievable data density.
H enhancement of N vacancy migration in GaN
Authors: Wixom R. R. , Wright A. F.
Published: November 2005

We have used density functional theory to investigate diffusion of VN+ in the presence of H+. Optimal migration pathways were determined using the climbing image nudged elastic band and directed dimer methods. Our calculations indicate that the rate-limiting barrier for VN+ migration will be reduced by 0.58 eV by interplay with H+, which will enhance migration by more than an order of magnitude at typical GaN growth temperatures.
Thermoelectric properties and figure of merit of a Te-doped InSb bulk single crystal
Authors: Yamaguchi Shigeo , Matsumoto Takayuki , Yamazaki Jun , Kaiwa Nakaba , Yamamoto Atsushi
Published: November 2005

We studied the temperature dependence of the thermoelectric properties of a Te-doped InSb bulk single crystal. The temperature was in the range from 10 to 723 K. We analyzed the scattering mechanisms throughout the whole temperature range and found that above 50 K, scattering by polar optical phonons was dominant. The maximum value of the dimensionless figure of merit was 0.6 at 673 K. The load characteristics of the sample were an open output voltage of 28 mV and a maximum output power of 216μW at a temperature difference of 195 K.
Room temperature continuous-wave operation of InAsSb quantum-dot distributed feedback lasers
Authors: Qiu Yueming , Yang Rui Q.
Published: November 2005

InAsSb self-assembled quantum-dot (QD) distributed feedback (DFB) lasers based on (001) InP substrate have been grown by metalorganic vapor-phase epitaxy. A highly tensile-strained InGaAs was used as the barrier layer for InAsSb QDs. Single-mode emissions near 1.87μm have been demonstrated from narrow ridge waveguide DFB lasers in continuous-wave operation at temperatures up to 320K (47°C), with a characteristics temperature of 55K up to temperature of 310K.
Contactless electroreflectance and photoreflectance studies of n- and p-type-doped GaN with Ga and N face
Authors: Chang C. H. , Wang D. P. , Wu C. C. , Hsiao C. L. , Tu L. W.
Published: November 2005

GaN films with Ga or N face and of n- or p-type doping were grown by plasma-assisted molecular-beam epitaxy. The wurtzite GaN exhibits a large polarization, with spontaneous and piezoelectric components. The direction of polarization, and thus polarization-induced electric fields, Fp is determined by the polarity of the sample. Contactless electroreflectance (CER) has already been employed to study the nature of band bending in GaAs samples. In this work, CER is used to study the band bending of the GaN samples. It was found that the phase of CER is determined by the type of doping, rather than by the polarity of the surface. Additionally, the photoreflectance (PR) spectra were also measured. Comparing CER with PR determines the type of doping.
Lattice location and thermal evolution of small B complexes in crystalline Si
Authors: Romano L. , Piro A. M. , Mirabella S. , Grimaldi M. G. , Rimini E.
Published: November 2005

The lattice location of B in Si has been investigated by channelling analyses using nuclear reactions (650keV proton beam, B11(p,α)Be8). The formation at room temperature of a specific, small B complex in presence of an excess of point defects has been inferred. In particular, B implanted in Si or B substitutional dissolved in Si and irradiated with proton beam form a unique B complex with B atoms not randomly located. The angular scans along the ⟨100⟩ and ⟨110⟩ axes are compatible with B–B pairs aligned along the ⟨100⟩ axis. The thermal annealing in the 200–950°C range of the B complexes, analyzed by lattice location and carrier concentration measurements, depends on the residual defect density in the lattice. The B complexes dissolve at low temperature if no excess of Si self-interstitials (Is) exists or they evolve into large B clusters and then dissolve at high temperature if Is supersaturation holds.
Simple procedure to extract speed distributions from ion images with a large background contribution
Authors: Braun Andreas , Drabbels Marcel
Published: November 2005

We present a simple and robust procedure that allows extracting with high fidelity speed distributions from ion images that contain a large background contribution. The procedure requires no detailed knowledge about the background and is conveniently applied after performing the inverse Abel transform that reconstructs the three-dimensional velocity distribution from a recorded image.
Mechanisms regulating tissue-specific polarity of monocarboxylate transporters and their chaperone CD147 in kidney and retinal epithelia
Authors: Deora Ami A. , Philp Nancy , Hu Jane , Bok Dean , Rodriguez-Boulan Enrique
Published: November 2005

Proton-coupled monocarboxylate transporters (MCT) MCT1, MCT3, and MCT4 form heterodimeric complexes with the cell surface glycoprotein CD147 and exhibit tissue-specific polarized distributions that are essential for maintaining lactate and pH homeostasis. In the parenchymal epithelia of kidney, thyroid, and liver, MCT/CD147 heterocomplexes are localized in the basolateral membrane where they transport lactate out of or into the cell depending on metabolic conditions. A unique distribution of lactate transporters is found in the retinal pigment epithelium (RPE), which regulates lactate levels of the outer retina. In RPE, MCT1/CD147 is polarized to the apical membrane and MCT3/CD147 to the basolateral membrane. The mechanisms responsible for tissue-specific polarized distribution of MCTs are unknown. Here, we demonstrate that CD147 carries sorting information for polarized targeting of the MCT1/CD147 hetero-complexes in kidney and RPE cells. In contrast, MCT3 and MCT4 harbor dominant sorting information that cotargets CD147 to the basolateral membrane in both epithelia. RNA interference experiments show that MCT1 promotes CD147 maturation. Our results open a unique paradigm to study the molecular basis of tissue-specific polarity.
Electrocatalytic hydrogen oxidation by an enzyme at high carbon monoxide or oxygen levels
Authors: Vincent Kylie A. , Cracknell James A. , Lenz Oliver , Zebger Ingo , Friedrich Bärbel , Armstrong Fraser A.
Published: November 2005

Use of hydrogen in fuel cells requires catalysts that are tolerant to oxygen and are able to function in the presence of poisons such as carbon monoxide. Hydrogen-cycling catalysts are widespread in the bacterial world in the form of hydrogenases, enzymes with unusual active sites composed of iron, or nickel and iron, that are buried within the protein. We have established that the membrane-bound hydrogenase from the β-proteobacterium
Ralstonia eutropha
H16, when adsorbed at a graphite electrode, exhibits rapid electrocatalytic oxidation of hydrogen that is completely unaffected by carbon monoxide [at 0.9 bar (1 bar = 100 kPa), a 9-fold excess] and is inhibited only partially by oxygen. The practical significance of this discovery is illustrated with a simple fuel cell device, thus demonstrating the feasibility of future hydrogen-cycle technologies based on biological or biologically inspired electrocatalysts having high selectivity for hydrogen.
Brain lactate kinetics: Modeling evidence for neuronal lactate uptake upon activation
Authors: Aubert Agnès , Costalat Robert , Magistretti Pierre J. , Pellerin Luc
Published: November 2005

A critical issue in brain energy metabolism is whether lactate produced within the brain by astrocytes is taken up and metabolized by neurons upon activation. Although there is ample evidence that neurons can efficiently use lactate as an energy substrate, at leastin vitro, few experimental data exist to indicate that it is indeed the casein vivo. To address this question, we used a modeling approach to determine which mechanisms are necessary to explain typical brain lactate kinetics observed upon activation. On the basis of a previously validated model that takes into account the compartmentalization of energy metabolism, we developed a mathematical model of brain lactate kinetics, which was applied to published data describing the changes in extracellular lactate levels upon activation. Results show that the initial dip in the extracellular lactate concentration observed at the onset of stimulation can only be satisfactorily explained by a rapid uptake within an intraparenchymal cellular compartment. In contrast, neither blood flow increase, nor extracellular pH variation can be major causes of the lactate initial dip, whereas tissue lactate diffusion only tends to reduce its amplitude. The kinetic properties of monocarboxylate transporter isoforms strongly suggest that neurons represent the most likely compartment for activation-induced lactate uptake and that neuronal lactate utilization occurring early after activation onset is responsible for the initial dip in brain lactate levels observed in both animals and humans.
Measles virus replication in lymphatic cells and organs of CD150 (SLAM) transgenic mice
Authors: Welstead G. Grant , Iorio Caterina , Draker Ryan , Bayani Jane , Squire Jeremy , Vongpunsawad Sompong , Cattaneo Roberto , Richardson Christopher D.
Published: November 2005

A transgenic mouse containing the complete human SLAM (hSLAM/CD150) gene, including its endogenous promoter for transcription, was generated by using human genomic DNA cloned into a bacterial artificial chromosome. hSLAM, the primary receptor for measles viruses (MV), was expressed on activated B, T, and dendritic cells with an expression profile equivalent to that of humans. We demonstrated that hSLAM
+
cells obtained from the transgenic mouse, including activated B, T, and dendritic cells, were susceptible to MV infection in a receptor-dependent manner. Evidence was provided for transient infection in the nasal lymph nodes of hSLAM
+
mice after intranasal inoculation. Virus was rapidly cleared without signs of secondary replication. To improve the efficiency of MV production, the hSLAM
+
mice were bred with mice having a
Stat1
-deficient background. These mice were more susceptible to MV infection and produced more virus particles. After intranasal and intraperitoneal inoculation of these mice with MV, infections of the thymus, spleen, nasal, mesenteric, and leg lymph nodes were detected. Upon necropsy, enlarged lymph nodes and spleen were apparent. Flow cytometric analysis showed that abnormally large numbers of mature neutrophils and natural killer cells caused the splenomegaly. The hSLAM transgenic mouse constitutes an improved rodent model for studying the interaction of MV with immune cells that more accurately reflects the infection pattern found in humans.
Rapid perceptual integration of facial expression and emotional body language
Authors: Meeren Hanneke K. M. , van Heijnsbergen Corné C. R. J. , de Gelder Beatrice
Published: November 2005

In our natural world, a face is usually encountered not as an isolated object but as an integrated part of a whole body. The face and the body both normally contribute in conveying the emotional state of the individual. Here we show that observers judging a facial expression are strongly influenced by emotional body language. Photographs of fearful and angry faces and bodies were used to create face-body compound images, with either matched or mismatched emotional expressions. When face and body convey conflicting emotional information, judgment of facial expression is hampered and becomes biased toward the emotion expressed by the body. Electrical brain activity was recorded from the scalp while subjects attended to the face and judged its emotional expression. An enhancement of the occipital P1 component as early as 115 ms after presentation onset points to the existence of a rapid neural mechanism sensitive to the degree of agreement between simultaneously presented facial and bodily emotional expressions, even when the latter are unattended.
Long-range protein electron transfer observed at the single-molecule level:
In situ
mapping of redox-gated tunneling resonance
Authors: Chi Qijin , Farver Ole , Ulstrup Jens
Published: November 2005

A biomimetic long-range electron transfer (ET) system consisting of the blue copper protein azurin, a tunneling barrier bridge, and a gold single-crystal electrode was designed on the basis of molecular wiring self-assembly principles. This system is sufficiently stable and sensitive in a quasi-biological environment, suitable for detailed observations of long-range protein interfacial ET at the nanoscale and single-molecule levels. Because azurin is located at clearly identifiable fixed sites in well controlled orientation, the ET configuration parallels biological ET. The ET is nonadiabatic, and the rate constants display tunneling features with distance-decay factors of 0.83 and 0.91 Å
–1
in H
2
O and D
2
O, respectively. Redox-gated tunneling resonance is observed
in situ
at the single-molecule level by using electrochemical scanning tunneling microscopy, exhibiting an asymmetric dependence on the redox potential. Maximum resonance appears around the equilibrium redox potential of azurin with an on/off current ratio of ≈9. Simulation analyses, based on a two-step interfacial ET model for the scanning tunneling microscopy redox process, were performed and provide quantitative information for rational understanding of the ET mechanism.
Mullerian Inhibiting Substance acts as a motor neuron survival factor
in vitro
Authors: Wang Pei-Yu , Koishi Kyoko , McGeachie Andrew B. , Kimber Michael , MacLaughlin David T. , Donahoe Patricia K. , McLennan Ian S.
Published: November 2005

The survival of motor neurons is controlled by multiple factors that regulate different aspects of their physiology. The identification of these factors is important because of their relationship to motor neuron disease. We investigate here whether Mullerian Inhibiting Substance (MIS) is a motor neuron survival factor. We find that motor neurons from adult mice synthesize MIS and express its receptors, suggesting that mature motor neurons use MIS in an autocrine fashion or as a way to communicate with each other. MIS was observed to support the survival and differentiation of embryonic motor neurons
in vitro
. During development, male-specific MIS may have a hormone effect because the blood-brain barrier has yet to form, raising the possibility that MIS participates in generating sex-specific differences in motor neurons.
An immune-responsive serpin, SRPN6, mediates mosquito defense against malaria parasites
Authors: Abraham Eappen G. , Pinto Sofia B. , Ghosh Anil , Vanlandingham Dana L. , Budd Aidan , Higgs Stephen , Kafatos Fotis C. , Jacobs-Lorena Marcelo , Michel Kristin
Published: November 2005

We have functionally analyzed the orthologous
SRPN6
genes from
Anopheles stephensi
and
Anopheles gambiae
using phylogenetic, molecular, reverse genetic, and cell biological tools. The results strongly implicate
SRPN6
in the innate immune response against
Plasmodium
. This gene belongs to a mosquito-specific gene cluster including three additional
Anopheles
serpins.
SRPN6
expression is induced by
Escherichia coli
and both rodent and human malaria parasites. The gene is specifically expressed in midgut cells invaded by
Plasmodium
ookinetes and in circulating and attached hemocytes. Knockdown of
SRPN6
expression by RNA interference in susceptible
An. stephensi
leads to substantially increased parasite numbers, whereas depletion in susceptible
An. gambiae
delays progression of parasite lysis without affecting the number of developing parasites. However, the
An. gambiae SRPN6
knockdown increases the number of melanized parasites in the L3-5 refractory strain and in susceptible G3 mosquitoes depleted of
CTL4
. These results indicate that
AsSRPN6
is involved in the parasite-killing process, whereas
AgSRPN6
acts on parasite clearance by inhibiting melanization and/or promoting parasite lysis. We propose that these observed phenotypic differences are due to changed roles of the respective target serine proteases in the two mosquito species.
Generation of tissue-specific transgenic birds with lentiviral vectors
Authors: Scott Benjamin B. , Lois Carlos
Published: November 2005

Birds are of great interest for a variety of research purposes, and effective methods for manipulating the avian genome would greatly accelerate progress in fields that rely on birds as model systems for biological research, such as developmental biology and behavioral neurobiology. Here, we describe a simple and effective method for producing transgenic birds. We used lentiviral vectors to produce transgenic quails that express GFP driven by the human synapsin gene I promoter. Expression of GFP was specific to neurons and consistent across multiple generations. Expression was sufficient to allow visualization of individual axons and dendrites of neurons
in vivo
by intrinsic GFP fluorescence. Tissue-specific transgene expression at high levels provides a powerful tool for biological research and opens new avenues for genetic manipulation in birds.
Strain gauge measurement of rein tension during riding: a pilot study
Authors: Clayton Hilary M , Singleton Wesley H , Lanovaz Joel L , Cloud Gary L
Published: November 2005

A pilot study was performed using a strain gauge transducer intercalated between the bit and the left rein to measure rein tension dynamically during riding. The strain patterns consisted of a series of spikes with frequencies corresponding to two per stride in walk and trot and one per stride in canter. The highest tension recorded in each gait was 43 N at walk, 51 N at trot and 104 N in canter. Based on the results of this study, it is recommended that the methodology should be adapted so that both reins are instrumented simultaneously, data are transmitted telemetrically to eliminate the need for a tether connecting the horse to the computer, and kinematic data are synchronized with the rein tension recordings.
Cyclical plasma electrolyte and acid–base responses to meal feeding in horses over a 24-h period
Authors: Waller Amanda , Smithurst Kerri Jo , Ecker Gayle L , Geor Ray , Lindinger Michael I
Published: November 2005

The present study used the physicochemical approach to characterize the changes in plasma electrolyte and acid–base states that occur in horses in response to feeding. Jugular venous blood was sampled every 0.5–2 h over a 24-h period from two groups (n = 4 and n = 5) of Standardbreds fed a mixed hay and grain ration at 8 am and 7 pm. One group of horses was studied in October, and one in December. The time course and magnitude of feeding responses differed between groups, and between the morning and evening meals. Feeding-induced changes in plasma electrolyte and acid–base variables occurred rapidly, within the first 1–3 h of meal consumption. The plasma acidosis associated with eating the meal was marked by increased plasma [H+] and decreased TCO2. The primary contributors to the increases in plasma [H+] were the decrease in the plasma concentration of strong ions ([SID]) and the pCO2. The increase in plasma total weak acid (protein) concentration ([Atot]) post-feeding had only a minor effect on the acid–base state. The feeding-induced acidosis abated 3–6 h after the meal, showing cyclical recovery of physicochemical variables that contributed to the acid–base disturbance. It is concluded that several key plasma electrolyte and acid–base parameters undergo significant, cyclical fluctuations in response to feeding in horses.
Comparison of oxidative stress and antioxidant status in endurance horses in three 80-km races
Authors: Williams CA , Kronfeld DS , Hess TM , Saker KE , Waldron JE , Crandell KM , Harris PA
Published: November 2005

This study tested our hypothesis that during an 80-kmResearch Ridein 2002 (R2) horses that did not finish (NF) the ride would have elevated muscle enzyme activities in the blood and changes in biomarkers of oxidative stress as compared to horses that finished (F) the ride. These results were then compared to previous rides –Old Dominion(OD) and theResearch Ride 2001(R1). For R2, 40 mostly Arabian horses competed and had blood samples collected before, at 27, 48 and 80 km, and 170 to 190 min after the 80-km race. Blood was collected similarly in R1 and OD. Blood was analysed for plasma lipid hydroperoxides (LPO), α-tocopherol (TOC), creatine kinase (CK), aspartate aminotransferase (AST), red and white blood cell total glutathione (GSH-T) and glutathione peroxidase (GPx). Data were analysed using a repeated measure ANOVA in SAS. Associations between muscle enzymes and antioxidant status were determined using Pearson's or Spearman's correlations. Activities of CK and AST were higher (P<0.05) before, during and after the ride in NF than in F; however, TOC, LPO, GSH-T and GPx were not different. In R2, negative correlations were found with GPx and CK (r= −0.21;P= 0.005), GPx and AST (r= −0.15;P= 0.05), and a positive correlation was found with GSH-T and CK (r= 0.18;P= 0.02). Values of CK, LPO, GPx and GSH-T were higher (P<0.05) in R2 than in R1 or OD. The overall comparison of 80-km endurance races suggests the importance of considering the horse's fitness, terrain, ambient conditions and calibre of race when interpreting results from markers of oxidative stress and muscle enzyme leakage.
Vitamin E intake and systemic antioxidant status in competitive endurance horses
Authors: Williams CA , Kronfeld DS , Hess TM , Saker KE , Waldron JE , Harris PA
Published: November 2005

The objective was to compare vitamin E content in the total diet of Arabian horses competing in the 80 km Research Ride 2002 to the oxidative stress and antioxidant measures throughout the race. Prior to the race, riders completed a detailed nutritional survey, which was used to calculate vitamin E intake. Blood samples, temperature and heart rate were taken the day before the race, at 27 and 48 km during the race, at race completion or elimination and 3 h after race completion. Plasma lipid hydroperoxides, α-tocopherol (TOC), creatine kinase (CK), aspartate aminotransferase (AST), albumin, red and white blood cell total glutathione and glutathione peroxidase were measured. Data were analyzed by Pearson's correlation in SAS. From the survey, it was estimated that horses consumed 2265±114 IU day−1 of vitamin E. A negative correlation was found between the vitamin E intake and CK (r = −0.23; P = 0.002), and AST (r = −0.22; P = 0.003). A positive correlation was found between the vitamin E intake and plasma TOC (r = 0.15; P = 0.005) at all sample times. This suggests that intensely exercising horses supplemented with vitamin E may not have an improved welfare and performance if they are supplemented vitamin E versus what is naturally found in forages and commercial feeds.
Localization of MMR proteins on meiotic chromosomes in mice indicates distinct functions during prophase I
Authors: Kolas Nadine K. , Svetlanov Anton , Lenzi Michelle L. , Macaluso Frank P. , Lipkin Steven M. , Liskay R. Michael , Greally John , Edelmann Winfried , Cohen Paula E.
Published: November 2005

Mammalian MutL homologues function in DNA mismatch repair (MMR) after replication errors and in meiotic recombination. Both functions are initiated by a heterodimer of MutS homologues specific to either MMR (MSH2–MSH3 or MSH2–MSH6) or crossing over (MSH4–MSH5). Mutations of three of the four MutL homologues (Mlh1, Mlh3, and Pms2) result in meiotic defects. We show herein that two distinct complexes involving MLH3 are formed during murine meiosis. The first is a stable association between MLH3 and MLH1 and is involved in promoting crossing over in conjunction with MSH4–MSH5. The second complex involves MLH3 together with MSH2–MSH3 and localizes to repetitive sequences at centromeres and the Y chromosome. This complex is up-regulated in Pms2−/− males, but not females, providing an explanation for the sexual dimorphism seen in Pms2−/− mice. The association of MLH3 with repetitive DNA sequences is coincident with MSH2–MSH3 and is decreased in Msh2−/− and Msh3−/− mice, suggesting a novel role for the MMR family in the maintenance of repeat unit integrity during mammalian meiosis.
Protection from Alzheimer's-like disease in the mouse by genetic ablation of inducible nitric oxide synthase
Authors: Nathan Carl , Calingasan Noel , Nezezon Jon , Ding Aihao , Lucia M. Scott , La Perle Krista , Fuortes Michele , Lin Michael , Ehrt Sabine , Kwon Nyoun Soo , Chen Junyu , Vodovotz Yoram , Kipiani Khatuna , Beal M. Flint
Published: November 2005

Brains from subjects who have Alzheimer's disease (AD) express inducible nitric oxide synthase (iNOS). We tested the hypothesis that iNOS contributes to AD pathogenesis. Immunoreactive iNOS was detected in brains of mice with AD-like disease resulting from transgenic expression of mutant human β-amyloid precursor protein (hAPP) and presenilin-1 (hPS1). We bred hAPP-, hPS1-double transgenic mice to be iNOS+/+ or iNOS−/−, and compared them with a congenic WT strain. Deficiency of iNOS substantially protected the AD-like mice from premature mortality, cerebral plaque formation, increased β-amyloid levels, protein tyrosine nitration, astrocytosis, and microgliosis. Thus, iNOS seems to be a major instigator of β-amyloid deposition and disease progression. Inhibition of iNOS may be a therapeutic option in AD.
A Spatiotemporal White Noise Analysis of Photoreceptor Responses to UV and Green Light in the Dragonfly Median Ocellus
Authors: van Kleef Joshua , James Andrew Charles , Stange Gert
Published: November 2005

Adult dragonflies augment their compound eyes with three simple eyes known as the dorsal ocelli. While the ocellar system is known to mediate stabilizing head reflexes during flight, the ability of the ocellar retina to dynamically resolve the environment is unknown. For the first time, we directly measured the angular sensitivities of the photoreceptors of the dragonfly median (middle) ocellus. We performed a second-order Wiener Kernel analysis of intracellular recordings of light-adapted photoreceptors. These were stimulated with one-dimensional horizontal or vertical patterns of concurrent UV and green light with different contrast levels and at different ambient temperatures. The photoreceptors were found to have anisotropic receptive fields with vertical and horizontal acceptance angles of 15° and 28°, respectively. The first-order (linear) temporal kernels contained significant undershoots whose amplitudes are invariant under changes in the contrast of the stimulus but significantly reduced at higher temperatures. The second-order kernels showed evidence of two distinct nonlinear components: a fast acting self-facilitation, which is dominant in the UV, followed by delayed self- and cross-inhibition of UV and green light responses. No facilitatory interactions between the UV and green light were found, indicating that facilitation of the green and UV responses occurs in isolated compartments. Inhibition between UV and green stimuli was present, indicating that inhibition occurs at a common point in the UV and green response pathways. We present a nonlinear cascade model (NLN) with initial stages consisting of separate UV and green pathways. Each pathway contains a fast facilitating nonlinearity coupled to a linear response. The linear response is described by an extended log-normal model, accounting for the phasic component. The final nonlinearity is composed of self-inhibition in the UV and green pathways and inhibition between these pathways. The model can largely predict the response of the photoreceptors to UV and green light.
Status of the Intracellular Gate in the Activated-not-open State of Shaker K+ Channels
Authors: del Camino Donato , Kanevsky Max , Yellen Gary
Published: November 2005

Voltage-dependent K+ channels like Shaker use an intracellular gate to control ion flow through the pore. When the membrane voltage becomes more positive, these channels traverse a series of closed conformations before the final opening transition. Does the intracellular gate undergo conformational changes before channel opening? To answer this question we introduced cysteines into the intracellular end of the pore and studied their chemical modification in conditions favoring each of three distinct states, the open state, the resting closed state, and the activated-not-open state (the closed state adjacent to the open state). We used two independent ways to isolate the channels in the activated-not-open state. First, we used mutations in S4 (ILT; Smith-Maxwell, C.J., J.L. Ledwell, and R.W. Aldrich. 1998. J. Gen. Physiol. 111:421–439; Ledwell, J.L., and R.W. Aldrich. 1999. J. Gen. Physiol. 113:389–414) that separate the final opening step from earlier charge-movement steps. Second, we used the open channel blocker 4-aminopyridine (4-AP), which has been proposed to promote closure of the intracellular gate and thus specifically to stabilize the activated-not-open state of the channels. Supporting this proposed mechanism, we found that 4-AP enters channels only after opening, remaining trapped in closed channels, and that in the open state it competes with tetraethylammonium for binding. Using these tools, we found that in the activated-not-open state, a cysteine located at a position considered to form part of the gate (Shaker 478) showed higher reactivity than in either the open or the resting closed states. Additionally, we have found that in this activated state the intracellular gate continued to prevent access to the pore by molecules as small as Cd2+ ions. Our results suggest that the intracellular opening to the pore undergoes some rearrangements in the transition from the resting closed state to the activated-not-open state, but throughout this process the intracellular gate remains an effective barrier to the movement of potassium ions through the pore.
A Critical Analysis of Chromotherapy and Its Scientific Evolution
Authors: Azeemi Samina T. Yousuf , Raza Mohsin
Published: November 2005

Chromotherapy is a method of treatment that uses the visible spectrum (colors) of electromagnetic radiation to cure diseases. It is a centuries‐old concept used successfully over the years to cure various diseases. We have undertaken a critical analysis of chromotherapy and documented its scientific evolution to date. A few researchers have tried to discover the underlying scientific principles, but without quantitative study. Sufficient published material can be found about the subject that provides a complete system of treatment focused on the treatment methodologies and healing characteristics of colors. A number of studies have elaborated the relationship between the human body and colors. We also show the possibility of carrying out diverse research into chromotherapy that is pertinent to deciphering the quantum mechanical dipole moment of water molecules. The quantum mechanical dipole moment as a result of the absorption of different colors, we conjecture, produces charge quantization phenomena. This review illustrates that the development of science in the field of electromagnetic radiation/energy can be very helpful in discovering new dimensions of this old theory.
Proust, a Fountain and some Pink Marble
Authors: Baldwin Thomas
Published: November 2005

This article is in two parts. The first concerns a description of the ‘Hubert Robert fountain’ that occurs towards the beginning of
Sodome et Gomorrhe.
The second concerns the narrator's description in
Le Temps retrouvé
of the ‘matière’ of his work as ‘distincte, nouvelle, d'une transparence, d'une sonorité spéciales, compacte, fraîchissante et rose’.

1

The two parts are connected by a transformatory effect. In the first, an object that enters the world of the text as a ‘real’ fountain, mimetically described, is transformed into a fountain depicted in a painting that the text describes ekphrastically. This painting then changes from a naturalistic depiction into a Cubist-type composition (a painting that stresses the literalness of its surface), only to turn back into an actual fountain. Proust's internal description of the novel undergoes a similar transformation. Having filled the novel with descriptions of depicted and actual things, he menaces the reader with the possibility that the virtual world is about to vanish, that the novel is a piece of marble or flesh, pink, compact and transparent — a real and tangible object.
Quand les Antillais relisent Aristote: un tragique de la latence
Authors: Douaire Anne
Published: November 2005

Dans le second
xx
ème
siècle, les littératures de Martinique et de Guadeloupe (F. W. I.), cherchant à exprimer le dit ‘malaise antillais’ fondé sur la non-histoire, s'emparent d'une catégorie esthétique occidentale: le tragique. Confronté aux particularités de ces sociétés, et à la volonté des auteurs de ne pas s'inscrire sans dispute dans le canon littéraire européen, le tragique subit une série de transformations. Celles-ci naissent d'abord du contexte historique, qui empêche une pensée sereine de la fondation sociale, puisque les écrivants sont pour la plupart des membres du peuple vaincu et colonisé et à ce titre ne peuvent idéologiquement se faire les thuriféraires d'un ordre établi et honni. Cette situation a des conséquences littéraires, l'opposition de deux forces légitimes se muant en l'écrasement toujours-déjà achevé d'une collectivité. Plus d'engrenage fatal donc, qui mènerait un héros solaire au sacrifice, mais une latence dysphorique engluant tout un peuple dans sa ‘toile de néant’ (Glissant). Les œuvres de Glissant, de Césaire, mais aussi de Chamoiseau ou Boukman servent de fondement à une discussion sur la valeur canonique du tragique: si l'on peut, modifiant les prétendus impératifs génériques (exemplarité du héros, abstraction universalisante, engrenage dramaturgique), créer par les textes une émotion tragique (que l'on caractérise comme un tragique de la latence), c'est qu'un détour par le corpus antillais, loin de dénaturer une catégorie esthétique, enrichit sa compréhension.
Classical computation with quantum systems
Authors: Delaney P , Greer J.C
Published: November 2005

As semiconductor electronic devices scale to the nanometer range and quantum structures (molecules, fullerenes, quantum dots, nanotubes) are investigated for use in information processing and storage, it becomes useful to explore the limits imposed by quantum mechanics on classical computing. To formulate the problem of a quantum mechanical description of classical computing, electronic device and logic gates are described as quantum sub-systems with inputs treated as boundary conditions, outputs expressed as operator expectation values, and transfer characteristics and logic operations expressed through the sub-system Hamiltonian, with constraints appropriate to the boundary conditions. This approach, naturally, leads to a description of the sub-systems in terms of density matrices. Application of the maximum entropy principle subject to the boundary conditions (inputs) allows for the determination of the density matrix (logic operation), and for calculation of expectation values of operators over a finite region (outputs). The method allows for an analysis of the static properties of quantum sub-systems.