bluuebunny/crossref_metadata_2025 huggingface dataset:
Are oral cannabinoids safe and effective in refractory neuropathic pain?
Authors: Attal N. , Brasseur L. , Guirimand D. , Clermond‐Gnamien S. , Atlami S. , Bouhassira D.
Published: September 2003

Although cannabinoids have anti‐hyperalgesic effects in animal models of nerve injury, there are currently very few prospective trials of the efficacy of cannabinoids in neuropathic pain in humans. This open label prospective study investigated the safety, tolerability and analgesic benefit of oral Δ‐9‐tetrahydrocannabinol (THC) titrated to a maximal dosage of 25 mg/day in 8 consecutive patients with chronic refractory neuropathic pain. Spontaneous ongoing and paroxysmal pain, allodynia and paresthesias were assessed. The sensory and affective components of pain using the McGill pain questionnaire, quality of life, mood, anxiety and functionality were also evaluated. Seven patients suffered from side effects necessitating premature arrest of the drug in 5 of them. THC (mean dosage: 16.6 ± 6.5 mg/day) did not induce any significant effects on ongoing and paroxysmal pain, allodynia, quality of life, anxiety/depression scores and functional impact of pain. These results do not support an overall benefit of THC in pain and quality of life in patients with refractory neuropathic pain.
Recurrent vomiting and ethylmalonic aciduria associated with rare mutations of the short‐chain acyl‐CoA dehydrogenase gene
Authors: Seidel J. , Streck S. , Bellstedt K. , Vianey‐Saban C. , Pedersen C. B. , Vockley J. , Korall H. , Roskos M. , Deufel T. , Trefz K. F. , Sewell A. C. , Kauf K. , Zintl F. , Lehnert W. , Gregersen N.
Published: September 2003

Summary: We report identification of short‐chain acyl‐CoA dehydrogenase (SCAD) deficiency in a 12‐year‐old boy who suffered from recurrent attacks of vomiting once or twice a year from infancy. Growth and development were normal and there were no muscular symptoms. Metabolic screening was performed during a hospitalization at 8 years of age and revealed an increased excretion of ethylmalonic acid (EMA; 45–80 mmol/mol creatinine, normal 0.2–6.6), suggesting a degradation defect of short‐chain fatty acids. An increased n‐butyrylcarnitine was found in freshly collected serum (0.9 µmol/L; normal <0.4) but not in dry blood spots. Neither of the frequent SCAD gene variants 625G>A and 511C>T was present, but direct sequencing of the promoter and coding regions of the SCAD gene revealed that the patient had mutations on both alleles: 417G>C (Trp115Cys) and 1095G>T (Gln341His). Neither mutation has been described before in compound heterozygosity or homozygosity. Enzymatic investigations subsequently confirmed a defect of SCAD in both fibroblasts and muscle extracts. Furthermore, expression studies of both mutations demonstrated impaired enzyme function or structure. To our knowledge, this case is the first description of a patient with proven SCAD deficiency presenting with recurrent emesis but without other symptoms, and emphasizes the wide clinical phenotype of this disorder.
Two adult galactosaemia females with normal ovarian function and identical GALT mutations (Q188R/R333G)
Authors: Ng W. G. , Xu Y‐K. , Wong L‐J. , Kaufman F. R. , Buist N. R. M. , Donnell G. N.
Published: September 2003

Summary: We report two unrelated cases of adult galactosaemia females with normal ovarian function and Q188R/R333G mutations. Clinical history has been followed for 40 years. Biochemical finding in one patient are consistent with the presence of small amounts of galactose‐1‐phosphate uridyltransferase (GALT) activity, which differs from classical galactosaemia.
The budding yeast Rad9 checkpoint complex: chaperone proteins are required for its function
Authors: Gilbert Christopher S , van den Bosch Michael , Green Catherine M , Vialard Jorge E , Grenon Muriel , Erdjument‐Bromage Hediye , Tempst Paul , Lowndes Noel F
Published: September 2003

Rad9 functions in the DNA‐damage checkpoint pathway of Saccharomyces cerevisiae. In whole‐cell extracts, Rad9 is found in large, soluble complexes, which have functions in amplifying the checkpoint signal. The two main soluble forms of Rad9 complexes that are found in cells exposed to DNA‐damaging treatments were purified to homogeneity. Both of these Rad9 complexes contain the Ssa1 and/or Ssa2 chaperone proteins, suggesting a function for these proteins in checkpoint regula‐tion. Consistent with this possibility, genetic experiments indicate redundant functions for SSA1 and SSA2 in survival, G2/M‐checkpoint regulation, and phosphorylation of both Rad9 and Rad53 after irradiation with ultraviolet light. Ssa1 and Ssa2 can now be considered as novel checkpoint proteins that are likely to be required for remodelling Rad9 complexes during checkpoint‐pathway activation.
Helicobacter pylori eradication is beneficial in the treatment of functional dyspepsia
Authors: Malfertheiner P. , MÖssner J. , Fischbach W. , Layer P. , Leodolter A. , Stolte M. , Demleitner K. , Fuchs W.
Published: September 2003

Aim : To assess whether the eradication of Helicobacter pylori leads to long‐term relief of symptoms in functional dyspepsia.

Methods : Eight hundred patients with functional dyspepsia were randomized to receive double‐blind treatment with twice‐daily 30 mg lansoprazole, 1000 mg amoxicillin and 500 mg clarithromycin for 7 days (L30AC), twice‐daily 15 mg lansoprazole, 1000 mg amoxicillin and 500 mg clarithromycin for 7 days (L15AC), or once‐daily 15 mg lansoprazole for 14 days (LP). Dyspepsia and reflux symptoms were monitored for 12 months.

Results : In intention‐to‐treat analysis, the non‐ulcer dyspepsia sum score showed a statistically significant benefit in terms of symptom relief in the L30AC group (P = 0.0068) compared with the LP group, but there was no significant difference between the L15AC and LP groups (P = 0.2). When all patients in the two eradication therapy arms were considered together, successful eradication had a significant benefit with regard to the complete absence of symptoms (P < 0.04). H. pylori eradication did not lead to an increase in reflux symptoms.

Conclusion : This study suggests that H. pylori infection causes dyspeptic symptoms in a subset of patients with functional dyspepsia, and that these patients may obtain long‐term symptomatic benefit following H. pylori eradication.
Prevalence, clinical spectrum and health care utilization of gastro‐oesophageal reflux disease in a Chinese population: a population‐based study
Authors: Wong W. M. , Lai K. C. , Lam K. F. , Hui W. M. , Hu W. H. C. , Lam C. L. K. , Xia H. H. X. , Huang J. Q. , Chan C. K. , Lam S. K. , Wong B. C. Y.
Published: September 2003

Background : Population‐based data on gastro‐oesophageal reflux disease in Chinese are lacking. The prevalence, clinical spectrum and health care‐seeking behaviour of subjects with gastro‐oesophageal reflux disease were studied.

Methods : Ethnic Chinese (3605) were invited to participate in a telephone survey using a validated gastro‐oesophageal reflux disease questionnaire and the Hospital Anxiety and Depression Scale.

Results : A total of 2209 subjects (58% female; mean age, 40.3 years) completed the interview. The annual, monthly and weekly prevalence rates of gastro‐oesophageal reflux disease were 29.8%, 8.9% and 2.5%, respectively. Gastro‐oesophageal reflux disease symptoms were associated with non‐cardiac chest pain [odds ratio (OR), 2.3; 95% confidence interval (95% CI), 1.7–3.1], dyspepsia (OR, 1.9; 95% CI, 1.4–2.5), globus (OR, 1.8; 95% CI, 1.2–2.7), acid feeling in the stomach (OR, 5.8; 95% CI, 4.5–7.5) and the use of non‐steroidal anti‐inflammatory drugs (OR, 2.3; 95% CI, 1.5–3.6), but not with dysphagia, bronchitis, asthma, hoarseness and pneumonia. Patients with gastro‐oesophageal reflux disease had a significantly higher anxiety and depression score and required more days off work when compared with subjects without. The frequency of heartburn (P = 0.032), female gender (P < 0.001), degree of depression (P = 0.004) and social morbidity (P < 0.001) were independent factors associated with health care‐seeking behaviour.

Conclusion : The prevalence of gastro‐oesophageal reflux disease was lower than that in Western populations, but carried a significant socio‐economic burden in the studied Chinese population. The frequency of heartburn, female gender and psychosocial factors were associated with health care utilization in gastro‐oesophageal reflux disease.
No volume effect on retrograde colonic spread of rectally‐administered ropivacaine gel
Authors: Arlander E. , Cederlund T. , Måre K.
Published: September 2003

Background : Rectal administration of enemas, foams and suppositories is the most efficient way to deliver locally acting drugs to the distal colon. Ropivacaine, a long‐acting local anaesthetic, was chosen as a candidate for a new rectal treatment of ulcerative colitis.

Aim : To determine the colonic spread of a rectal ropivacaine formulation.

Methods : In this randomized, incomplete cross‐over study, 12 male volunteers were given 200 mg ropivacaine HCl rectally in 20, 40, 60 and 80 mL hydroxypropyl methylcellulose gel. The viscosity of the gel was 1.1 Pa s. The spread of the radiolabelled (99mTc‐labelled diethylenetriaminepenta‐acetic acid) formulations was assessed by gamma‐scintigraphy. Plasma was collected and analysed for ropivacaine base.

Results : The retrograde spread was limited to the descending colon and the difference between the studied volumes was not statistically significant. Only the 80‐mL volume tended to have a larger distribution, although the 20‐mL volume showed the same maximal distribution in two subjects. No distinct relationship between volume, retrograde colonic spread and plasma concentrations could be found. Ropivacaine was well tolerated.

Conclusions : Rectal ropivacaine gel in all volumes between 20 and 80 mL can spread up to the descending colon. There was no relationship between either retrograde colonic spread or the administered volume and the ropivacaine plasma concentrations.
Stability of liquid bridges between an elliptical and a circular supporting disk
Authors: Laverón-Simavilla A. , Meseguer J. , Espino J. L.
Published: September 2003

A numerical method has been developed to determine the stability limits for liquid bridges held between noncircular supporting disks, and the application to a configuration with a circular and an elliptical disk subjected to axial acceleration has been made. The numerical method led to results very different from the available analytical solution, which has been revisited and a better approximation has been obtained. It has been found that just retaining one more term in the asymptotic analysis the solution reproduces the real behavior of the configuration and the numerical results.
On three-dimensional linear stability of Poiseuille flow of Bingham fluids
Authors: Frigaard Ian , Nouar Cherif
Published: September 2003

Plane channel Poiseuille flow of a Bingham fluid is characterized by the Bingham number, B, which describes the ratio of yield and viscous stresses. Unlike purely viscous non-Newtonian fluids, which modify hydrodynamic stability studies only through the dissipation and the basic flow, inclusion of a yield stress additionally results in a modified domain and boundary conditions for the stability problem. We investigate the effects of increasing B on the stability of the flow, using eigenvalue bounds that incorporate these features. As B→∞ we show that three-dimensional linear stability can be achieved for a Reynolds number bound of form Re=O(B3/4), for all wavelengths. For long wavelengths this can be improved to Re=O(B), which compares well with computed linear stability results for two-dimensional disturbances [J. Fluid Mech. 263, 133 (1994)]. It is also possible to find bounds of form Re=O(B1/2), which derive from purely viscous dissipation acting over the reduced domain and are comparable with the nonlinear stability bounds in J. Non-Newt. Fluid Mech. 100, 127 (2001). We also show that a Squire-like result can be derived for the plane channel flow. Namely, if the equivalent eigenvalue bounds for a Newtonian fluid yield a stability criterion, then the same stability criterion is valid for the Bingham fluid flow, but with reduced wavenumbers and Reynolds numbers. An application of these results is to bound the regions of parameter space in which computational methods need to be used.
Polarization dependences of surface plasmon bands and surface-enhanced Raman bands of single Ag nanoparticles
Authors: Itoh Tamitake , Hashimoto Kazuhiro , Ozaki Yukihiro
Published: September 2003

Polarization dependences of Rayleigh and surface-enhanced Raman scattering (SERS) were measured for individual Ag nanoparticles on which Rhodamine 6G molecules were adsorbed. It was found that the polarization dependencies of surface plasmon bands generated by the aggregation of SERS active Ag particles are well synchronous to those of Raman bands. This result strongly supports the recent electromagnetic SERS model that amplified electric field at particle junctions localized in the aggregate gives rise to SERS.
Meniscus motion in a prewetted capillary
Authors: Egorov Andrei G. , Kornev Konstantin G. , Neimark Alexander V.
Published: September 2003

A conventional description of the effect of meniscus friction is based on the concept of the dynamic contact angle θ, which depends on the meniscus velocity V according to the Tanner law, θ∝V1/3. However, recent high-resolution experiments on spontaneous uptake of wetting fluids by capillaries have questioned the universality of the Tanner law. We analyze a mechanism underlying the phenomenological concept of meniscus friction, which finds experimental confirmation. As a case study system, we consider a forced flow of meniscus in a cylindrical capillary. It is assumed that the capillary is prewetted and the coating uniform film could coexist with the static meniscus. Numerical analysis is restricted to van der Waals fluids for which the disjoining pressure Π as a function of film thickness h has the form Π∝h−3. For these fluids, the equilibrium apparent contact angle is zero. Within the lubrication approximation of the film flow, we show that the nonzeroth dynamic contact angle first appears when the fluid velocity exceeds a certain characteristic value. For smaller velocities, there is no appreciable distortion of the meniscus shape, compared to the equilibrium static configuration. The deformations of the film profile are concentrated at the transition zone between the macroscopic meniscus and the submicron precursor. While the concept of dynamic contact angle seems to be inappropriate for slow flows, the concept of contact line friction serves as a practical alternative to it. We show that when the velocity is slow and there is no visible contact angle, the friction is Newtonian, i.e., the relation between the pressure drop ΔP and the meniscus velocity is linear. As the velocity increases, the linear relation transforms into a nonlinear asymptotic law ΔP∝(V ln V)2/3.
Large eddy simulation of turbulent channel flows by the rational large eddy simulation model
Authors: Iliescu Traian , Fischer Paul F.
Published: September 2003

The rational large eddy simulation (RLES) model is applied to turbulent channel flows. This approximate deconvolution model is based on a rational (subdiagonal Padé) approximation of the Fourier transform of the Gaussian filter and is proposed as an alternative to the gradient (also known as the nonlinear or tensor-diffusivity) model. We used a spectral element code to perform large eddy simulations of incompressible channel flows at Reynolds numbers based on the friction velocity and the channel half-width Reτ=180 and Reτ=395. We compared the RLES model with the gradient model and the Smagorinsky model with Van Driest damping. The RLES model was much more stable than the gradient model and yielded improved results. Both the RLES model and the gradient model predicted the off-diagonal Reynolds stresses better than the Smagorinsky model with Van Driest damping. The latter, however, yielded better results for the diagonal Reynolds stresses.
Axisymmetric thermal wake interaction of two drops in a gravity field at low Reynolds and high Peclet numbers
Authors: Lavrenteva O. M. , Nir A.
Published: September 2003

The axisymmetric motion of two drops in a viscous fluid under combined effect of gravity and thermocapillarity is considered. The ambient fluid is isothermal far from the drops and the temperature of the leading drop exceeds that of the continuous media. At large Peclet number, thermal boundary layers are present along the interfaces, and thermal wakes are formed downstream of the drops. The interaction of the thermal wake, shedded from the leading drop, with the boundary layer of the trailing one was shown to influence significantly the temperature distribution on the surface of the latter. The induced change in the speed of the trailing drop is comparable in magnitude with its speed when isolated even for large separation distance between the drops where the hydrodynamic interaction is negligible. In the extreme case of very large Marangoni effect the direction of the trailing drop motion can be reversed.
Synthesis of ternary SiGeSn semiconductors on Si(100) via SnxGe1−x buffer layers
Authors: Bauer Matthew , Ritter Cole , Crozier P. A. , Ren Jie , Menendez J. , Wolf G. , Kouvetakis J.
Published: September 2003

Single-phase Si1−x−yGexSny alloys with random diamond cubic structures are created on Si(100) via ultrahigh vacuum chemical vapor deposition reactions of SnD4 with SiH3GeH3 at 350 °C. Commensurate heteroepitaxy is facilitated by Ge1−xSnx buffer layers, which act as templates that can conform structurally and absorb the differential strain imposed by the more rigid Si and Si–Ge–Sn materials. The crystal structure, elemental distribution and morphological properties of the Si1−x−yGexSny/Ge1−xSnx heterostructures are characterized by high-resolution electron microscopy, including electron energy loss nanospectroscopy, x-ray diffraction (rocking curves) and atomic force microscopy. These techniques demonstrate growth of perfectly epitaxial, uniform and highly aligned layers with atomically smooth surfaces and monocrystalline structures that have lattice constants close to that of Ge. Rutherford backscattering ion channeling shows that the constituent elements occupy random substitutional sites in the same average diamond cubic lattice and the Raman shifts are consistent with the lattice expansion produced by the Sn incorporation into SiGe tetrahedral sites.
Ferroelectric switching of strontium–barium–niobate crystals in pulsed fields
Authors: Volk T. , Isakov D. , Ivleva L. , Wöhlecke M.
Published: September 2003

In strontium–barium–niobate (SBN) polarization and switching processes under pulsed field differ from those in model ferroelectrics. In most SBN crystals, the polarization changes smoothly with relaxation times up to seconds even under fields strongly exceeding the coercive field. The kinetics are described with a power law. In some samples of a variety of compositions faster changes have been observed, but their characteristics fundamentally differ from those in model ferroelectrics. The peculiarities are evidently caused by the relaxor properties of SBN.
Growth of shocked gaseous interfaces in a conical geometry
Authors: Kumar Sanjay , Hornung H. G. , Sturtevant B.
Published: September 2003

The results of experiments on Richtmyer–Meshkov instability growth of multimode initial perturbations on an air–sulfur hexafluoride (SF6) interface in a conical geometry are presented. The experiments are done in a relatively larger shock tube. A nominally planar interface is formed by sandwiching a polymeric membrane between wire-mesh frames. A single incident shock wave ruptures the membrane resulting in multimode perturbations. The instability develops from the action of baroclinically deposited vorticity at the interface. The visual thickness δ of the interface is measured from schlieren photographs obtained in each run. Data are presented for δ at times when the interface has become turbulent. The data are compared with the experiments of Vetter [Shock Waves 4, 247 (1995)] which were done in a straight test section geometry, to illustrate the effects of area convergence. It is found from schlieren images that the interface thickness grows about 40% to 50% more rapidly than in Vetter’s experiments. Laser induced scattering is used to capture the air–helium interface at late times. Image processing of pictures is also used to determine the interface thickness in cases where it was not clear from the pictures and to obtain the dominant eddy–blob sizes in the mixing zone. Some computational studies are also presented to show the global geometry changes of the interface when it implodes into a conical geometry in both light–heavy and heavy–light cases.
Shock wave induced interaction of microbubbles and boundaries
Authors: Wolfrum B. , Kurz T. , Mettin R. , Lauterborn W.
Published: September 2003

In the present study we experimentally investigate bubble dynamics after laser induced shock wave exposure in the vicinity of salt crystals suspended in water. High-speed microscopic images show aspherical collapse and rebound of single and multiple bubbles with initial radii between 5 and 150 μm. Radius time curves of bubbles close to one boundary are compared to the bubble dynamics of a spherical model. The bubble dynamics strongly depends on the position of neighboring bubbles and on the number of boundaries given by the surrounding salt grains. After excitation bubbles are drawn to the closest particles in their vicinity. Subsequent application of shock waves leads to jet formation against the rigid boundaries. The bubbles often tend to form in or migrate into cracks on the crystal surfaces and sometimes lead to the breakage of particles due to rapid bubble dynamics. Similar behavior may occur in other cases where material damage is induced by shock waves in liquids such as lithotripsy or shock wave cleaning applications.
Lubrication analysis of thermocapillary-induced nonwetting
Authors: Sumner Loren B. S. , Wood Andrea M. , Neitzel G. Paul
Published: September 2003

Recent interest in the phenomenon of thermocapillary-induced noncoalescence and nonwetting has produced experimental evidence of the existence of a film of lubricating gas that prevents the two surfaces in question (liquid–liquid for noncoalescence; liquid–solid for nonwetting) from coming into contact with one another. Measurements further indicate that the pressure distribution in this film creates a dimpled liquid free-surface. Lubrication theory is employed to investigate the coupled effects of liquid and gas flows for a two-dimensional nonwetting case of a hot droplet pressed toward a cold wall. The analysis focuses on the respective roles of viscous and inertial forces on droplet deformation. Resultant droplet shapes show an influence of gas viscosity maintaining nonwetting and of inertia contributing to a dimple. Previous analyses of thermocapillary-driven flow in liquid layers and droplets model the gas as purely passive which cannot be the case in the present application.
Emission properties of a dual ion/electron point emitter based on In–Bi alloy
Authors: Hsieh Wen-Pin , Sheu B. L. , Wang Y. L.
Published: September 2003

A stable dual ion/electron point emitter based on In–Bi alloy has been fabricated. Its performance as a liquid metal ion source (LMIS) at 70–100 °C, which is much lower than the operating temperature of the Au–In emitter reported previously, is comparable to a typical Ga–LMIS. By terminating the ion emission using a specific solidification process under the presence of an extraction voltage, the solidified tip is transformed into a sharp field electron emitter with decent emission characteristics. The In–Bi alloy source is not only a LMIS for conventional focused ion beam systems but also a potential candidate for single-column dual focused ion/electron beam systems.
Continuous-wave millimeter wave generation at 94 GHz in a lithium niobate nonlinear optical waveguide using modulated optical input
Authors: Hori Toshihiro , Park Ki-Hwan
Published: September 2003

Continuous-wave millimeter wave signals are generated at 94 GHz in a LiNbO3 nonlinear optical waveguide. Optical light with two frequency components is introduced into an optical waveguide, and the generated millimeter waves are obtained from a terminal connected to the metallic traveling waveguide. The configuration is made with a LiNbO3 commercial phase modulator. The generated signals have square-law characteristics between the output and the input power. Experimentally obtained results show that the probable candidate of this physical mechanism is difference frequency generation in nonlinear optical materials.
Room-temperature Si single-electron memory fabricated by nanoimprint lithography
Authors: Wu Wei , Gu Jian , Ge Haixiong , Keimel Christopher , Chou Stephen Y.
Published: September 2003

We report the design, fabrication, and characterization of room-temperature Si single-electron memories using nanoimprint lithography (NIL). The devices consist of a narrow channel metal–oxide–semiconductor field-effect transistor and a sub-10-nm storage dot, which is located between the channel and the gate. The memories operate at room temperature by charging and discharging one electron in or out of the dot. The charge retention time is up to two days. NIL is shown to be tailored for nanodevice fabrication. By using NIL as a nanolithography tool, the single-electron memory is more feasible for mass production.
Local thermometry technique based on proximity-coupled superconductor/normal-metal/superconductor devices
Authors: Jiang Z. , Lim H. , Chandrasekhar V. , Eom J.
Published: September 2003

In mesoscopic superconductor/normal-metal/superconductor heterostructures, it is known that the resistance of the normal metal between the superconductors has a strong temperature dependence. Based on this phenomenon, we have developed a type of thermometer, which dramatically enhances our ability to measure the local electron temperature Te at low temperatures. Using this technique, we have been able to measure small temperature gradients across a micron-size sample, opening up the possibility of quantitatively measuring the thermal properties of mesoscopic devices.
CsI: a high effective gamma coating for plasma display panels
Authors: Vink T. J. , Verbeek R. G. F. A. , van Elsbergen V. , Bachmann P. K.
Published: September 2003

Reduction of the breakdown voltage in plasma panel discharge cells calls for electrode coatings with a high secondary-electron emission yield. MgO is most widely used in this field because of its high secondary-electron yield, which is primarily governed by ion-induced emission processes. To overcome the limits of ion-induced emission, opening an additional channel via photon-induced emission is a possible option. The present study shows that this is indeed feasible, with a photosensitive material showing a substantially higher effective secondary-electron emission coefficient γeff when compared to state-of-the-art MgO electrode films.
Subfemtosecond pulse generation by nonadiabatic molecular modulation
Authors: Wu Jian , Zeng Heping
Published: September 2003

We suggest a technique to generate subfemtosecond pulse train in a Raman generator driven by three sufficiently intense single-mode laser beams whose carrier frequencies are tuned off the Raman resonance with two different two-photon detunings. The Raman interaction establishes a molecular modulation through a nonadiabatic process. The simulation based on the first fundamental vibrational Raman transition of solid hydrogen indicates that subfemtosecond pulse train can be generated when the signs of the two-photon detunings are opposite. This opens an experimentally feasible way to observe enhanced generation of broadband Raman sidebands as well as compression of the phase-locked Raman sidebands into subfemtosecond pulse trains in the same Raman media with above- and below-resonance Raman excitations.
Electrostatically Controlled Interactions of Mouse Paneth Cell α-Defensins with Phospholipid Membranes
Authors: Cummings Jason E. , Satchell Donald P. , Shirafuji Yoshinori , Ouellette Andre J. , Vanderlick T. Kyle
Published: September 2003

Antimicrobial peptides of the innate immune systems of many organisms are known to interact with lipid membranes, with electrostatic interactions playing an important role. We have studied the interactions of the mouse α-defensin, cryptdin-4, and its precursor, procryptdin-4, with phospholipid model membranes in the form of vesicles. Both peptides induce ‘graded’ leakage of vesicle contents, however procryptdin-4 exhibits only minimal membrane disruptive activity. Vesicles containing a higher fraction of anionic lipid are more susceptible to peptide-induced leakage. Electrophoretic mobility measurements at several vesicle compositions reveal a correlation between the surface potential of vesicles and the peptide-induced vesicle leakage.
Steric and Counterion Effects on Cationic Surfactant Self-Assembly into Micelles and Liquid Crystals
Authors: Cassidy Marta A. , Warr Gregory G.
Published: September 2003

The roles of head-group size and counterion association on aggregate morphology in solution and lyotropic phases of cationic surfactants (tetradecyl trimethyl-, tetradecyl triethyl-, and tetradecyl tripropylammonium) are examined, using salicylate as a strongly binding counterion. Larger head groups are found to inhibit the formation of low-curvature structures such as bilayers, and salicylate binding excludes spherical micelles, so that both effects tend to favour locally cylindrical aggregates. Interfacial probes and ion flotation show that the binding of salicylate is reduced by increasing head-group size. In addition, a novel demixing is observed with features similar to lower consolute behaviour of other cationic surfactant systems.
Catanionic Microcrystals: Organic Platelets, Gigadalton ‘Molecules’, or Ionic Solids?
Authors: Zemb Thomas , Dubois Monique
Published: September 2003

We review known properties of catanionic bilayers—complex fluids containing anionic and cationic surfactants together—including the case of ‘true’, salt-free catanionic solutions. The properties of our interest include phase diagrams, salt effects, and chain melting that occurs in liquid crystal, as well as micron-sized aggregates, from nanodiscs to icosahedra.
Atomic Force Microscopy Imaging of Glucose Oxidase using Chemically Modified Tips
Authors: Losic Dusan , Short Ken , Shapter Joe G. , Gooding Justin J.
Published: September 2003

Atomic force microscopy (AFM) tips have been chemically modified using a variety of approaches mostly based on self-assembled monolayers (SAMs). Tips with both a hydrophobic and hydrophilic nature have been prepared and used to image glucose oxidase covalently attached to a self-assembled monolayer.
Sensory organ development in cultured striped trumpeter larvae Latris lineata: implications for feeding behaviour
Authors: Cobcroft J. M. , Pankhurst P. M.
Published: September 2003

Teleost larvae are reliant on sensory organs for feeding, in particular for the detection and subsequent capture of prey. The present study describes the development of sensory organs in cultured striped trumpeter larvae, Latris lineata. In addition, a short-term feeding trial was conducted to examine the feeding response of larvae with different senses available; streptomycin sulfate was used to ablate the superficial neuromasts, and testing larvae in the dark prevented visually mediated feeding. Some non-visual senses are available to striped trumpeter larvae from an early age, as indicated by the presence of superficial neuromasts at hatching, and innervated olfactory organs and a developed inner ear from Day 3 post hatching. The neuromasts proliferated on the head and body with increasing larval age, and formation of the lateral line canal had commenced by Day 26 post hatching. Oral taste buds were not present in any of the larvae examined, up to Day 26 post hatching. At hatching, the retina was at an early stage in development, but differentiated rapidly and was presumed functional coincident with the onset of feeding on Day 7 post hatching. The ventro-temporal retina was the last to differentiate, and was distorted by the embryonic fissure, such that larval vision in the forward and upward visual field would be compromised. In contrast, the dorso-temporal retina was the first area to differentiate, and presumptive rod and double-cone development occurred in this area from Days 11 and 16, respectively, indicating that the forward and downward directed visual field is most suited for acute image formation. Larvae on Day 18 post hatching demonstrated increased feeding with an increase in the senses available, with 8 ± 3% of streptomycin-treated larvae feeding in the dark (chemoreception and inner ear mechanoreception only) and 27 ± 5% of untreated larvae feeding in the light (all senses available). It remains to be demonstrated whether there is an advantage to larval growth and survival by providing live feed during the dark phase in culture, facilitating feeding 24 hours per day.
Development of three commercial sea cucumbers, Holothuria scabra, H. fuscogilva and Actinopyga mauritiana: larval structure and growth
Authors: Ramofafia C. , Byrne M. , Battaglene S. C.
Published: September 2003

Development of the tropical sea cucumbers Holothuria scabra, H. fuscogilva and Actinopyga mauritiana was investigated. Holothuria scabra developed through the feeding auricularia, the non-feeding doliolaria and the pentactula larval stages in 14–17 days at 26–28�C. Holothuria fuscogilva and A. mauritiana were reared to the auricularia and doliolaria stages respectively. The auricularia stage was reached by 40–70 h and the larvae developed lateral processes and a prominent ciliated band. Transformation to the doliolaria stage took 10–12 h and occurred on Days 9–12 in H. scabra and Days 12–22 in A. mauritiana. During this transition the ciliated band fragmented into ciliary rings, the location of which coincided with the lateral processes in the auriculariae. In H. scabra, metamorphosis to pentactulae (13–15 days) was marked by development of five primary tentacles and a ventroposterior podium. This podium was used to attach to the substratum. Newly settled pentactulae of H. scabra used their tentacles to test, adhere and move across the substratum. Development of a second podium marked the development of juveniles (14–17 days). Hyaline spheres were conspicuous in late auriculariae of H. scabra and may be an indicator of larval competence. They disappeared in the doliolaria stage, which suggests that they may function as nutritive reserves to sustain H. scabra through the non-feeding perimetamorphic period. Absence of these spheres in H. fuscogilva, and their poor growth in A. mauritiana, suggests the feeding protocol used may not be sufficient to support complete development in these species. Determination of food and culture conditions that promote hyaline sphere formation and control bacteria may be essential for successful culture of H. fuscogilva and A.�mauritiana.
Field study of pesticide leaching in an allophanic soil in New Zealand. 1: Experimental results
Authors: Close M. E. , Magesan G. N. , Lee R. , Stewart M. K. , Hadfield J. C.
Published: September 2003

Seven pesticides, 2,4-D, atrazine, hexazinone, picloram, procymidone, terbuthylazine, and triclopyr, were applied to a Horotiu soil (allophanic loamy silt) located near Hamilton, New Zealand, along with 2 tracer compounds, bromide and deuterated water. Their movement and persistence was monitored for about 2�years using soil sampling down to a maximum of 1 m and 9 suction cups located between 0.2 and 2.5 m down the profile. There was rapid leaching of the tracers as well as hexazinone, picloram, and, to a lesser extent, triclopyr. Procymidone was much less mobile but was very persistent. Atrazine, terbuthylazine, and 2,4-D showed low mobility and persistence at the study site. Bromide and hexazinone were observed in the underlying groundwater following winter recharge and an intensive irrigation period at the end of the study. There was slight adsorption of bromide by the allophane in the soil. The combination of both soil sampling and suction cups gave a more complete description of the leaching process and the distribution of the compound through the profile than either technique by itself. This combination is worthwhile and gives complementary information providing the strengths and limitations of both techniques are appreciated.
Heat Sensitivity in a Bentgrass Variant. Failure to Accumulate a Chloroplast Heat Shock Protein Isoform Implicated in Heat Tolerance
Authors: Wang Dongfang , Luthe Dawn S.
Published: September 2003

Two variants of creeping bentgrass (Agrostis stolonifera cv palustris), developed using tissue culture, have been used to determine the roles of chloroplast-localized small heat shock proteins (CP-sHSPs) in heat tolerance. Results from previous research indicate that the heat-tolerant variant expressed two additional CP-sHSP isoforms not expressed in the heat-sensitive variant, that accumulation of the additional CP-sHSP isoforms was genetically linked to thermotolerance, and that the presence of the additional isoforms in the heat-tolerant variant provided greater protection to photosystem II during heat stress. To determine the basis of the differential expression, we isolated the genes encoding the CP-sHSPs from both variants and characterized their structure and expression. Two genes, ApHsp26.2 and ApHsp26.7a, were isolated from the heat-tolerant variant, and three genes, ApHsp26.2m, ApHsp26.8, and ApHsp26.7b, were isolated from the heat-sensitive variant. The sequence of ApHsp26.2m from the heat-sensitive variant was identical to ApHsp26.2, except for a point mutation that generated a premature stop codon. Therefore, the protein product of ApHsp26.2m did not accumulate in the heat-sensitive line. Mass spectrometry analysis confirmed that ApHsp26.2 encoded for the CP-sHSP isoforms unique to the heat-tolerant variant. An identical mutation was detected in one of the three parental lines used to develop the creeping bentgrass variants. This suggests that ApHsp26.2m was inherited from this parent and did not arise from a mutation that occurred during tissue culture. The presence of two isoforms encoded by the same gene might be due to differential processing of the N-terminal amino acids during or after import into the chloroplast.
Persistence of Unselected Transgenic DNA during a Plastid Transformation and Segregation Approach to Herbicide Resistance
Authors: Ye Guang-Ning , Colburn Susan M. , Xu Charles W. , Hajdukiewicz Peter T. J. , Staub Jeffrey M.
Published: September 2003

The use of a nonlethal selection scheme, most often using the aadA gene that confers resistance to spectinomycin and streptomycin, has been considered critical for recovery of plastid transformation events. In this study, the plastid-lethal markers, glyphosate or phosphinothricin herbicides, were used to develop a selection scheme for plastids that circumvents the need for integration of an antibiotic resistance marker. The effect of selective agents on tobacco (Nicotiana tabacum) mesophyll chloroplasts was first examined by transmission electron microscopy. We found that at concentrations typically used for selection of nuclear transformants, herbicides caused rapid disintegration of plastid membranes, whereas antibiotics had no apparent effect. To overcome this apparent herbicide lethality to plastids, a “transformation segregation” scheme was developed that used two independent transformation vectors for a cotransformation approach and two different selective agents in a phased selection scheme. One transformation vector carried an antibiotic resistance (aadA) marker used for early nonlethal selection, and the other transformation vector carried the herbicide (CP4 or bar) resistance marker for use in a subsequent lethal selection phase. Because the two markers were carried on separate plasmids and were targeted to different locations on the plastid genome, we reasoned that segregation of the two markers in some transplastomic lines could occur. We report here a plastid cotransformation frequency of 50% to 64%, with a high frequency (20%) of these giving rise to transformation segregants containing exclusively the initially nonselected herbicide resistance marker. Our studies indicate a high degree of persistence of unselected transforming DNA, providing useful insights into plastid chromosome dynamics.
Overexpression of a Gene Encoding Hydrogen Peroxide-Generating Oxalate Oxidase Evokes Defense Responses in Sunflower
Authors: Hu Xu , Bidney Dennis L. , Yalpani Nasser , Duvick Jonathan P. , Crasta Oswald , Folkerts Otto , Lu Guihua
Published: September 2003

Oxalate oxidase (OXO) converts oxalic acid (OA) and O2 to CO2 and hydrogen peroxide (H2O2), and acts as a source of H2O2 in certain plant-pathogen interactions. To determine if the H2O2 produced by OXO can function as a messenger for activation of defense genes and if OXO can confer resistance against an OA-producing pathogen, we analyzed transgenic sunflower (Helianthus annuus cv SMF3) plants constitutively expressing a wheat (Triticum aestivum) OXO gene. The transgenic leaf tissues could degrade exogenous OA and generate H2O2. Hypersensitive response-like lesion mimicry was observed in the transgenic leaves expressing a high level of OXO, and lesion development was closely associated with elevated levels of H2O2, salicylic acid, and defense gene expression. Activation of defense genes was also observed in the transgenic leaves that had a low level of OXO expression and had no visible lesions, indicating that defense gene activation may not be dependent on hypersensitive response-like cell death. To further understand the pathways that were associated with defense activation, we used GeneCalling, an RNA-profiling technology, to analyze the alteration of gene expression in the transgenic plants. Among the differentially expressed genes, full-length cDNAs encoding homologs of a PR5, a sunflower carbohydrate oxidase, and a defensin were isolated. RNA-blot analysis confirmed that expression of these three genes was significantly induced in the OXO transgenic sunflower leaves. Furthermore, treatment of untransformed sunflower leaves with jasmonic acid, salicylic acid, or H2O2 increased the steady-state levels of these mRNAs. Notably, the transgenic sunflower plants exhibited enhanced resistance against the OA-generating fungus Sclerotinia sclerotiorum.
Small firm Internet adoption: opportunities forgone, a journey not begun
Authors: Jones Colin , Hecker Rob , Holland Peter
Published: September 2003

This paper explores the endeavours of five small firms to develop Web‐based commerce capabilities within their existing operations. The focus is on the strategic acquisition and exploitation of knowledge which underpins new value creating activities related to Web‐based commerce. A normative Web‐based commerce adoption model developed from a review of the extant literature related to electronic marketing, entrepreneurship, and the diffusion of new innovations was empirically tested. A multiple case study design enabled the exploration of contemporary marketing and entrepreneurship issues within the real life context of five small firms. The model aimed to emphasis best‐practice adoption methods emphasizing the value of a firm’s market orientation and entrepreneurial capabilities. A preliminary test of the model’s theoretical contentions lent support to its overall focus, but found that the firm’s existing learning capabilities were diminished during the adoption of Web‐based commerce, and that a lack of vision and prior knowledge produced sub‐optimal adoption outcomes.
Studying the Effects of Early Child Care Experiences on the Development of Children of Color in the United States: Toward a More Inclusive Research Agenda
Authors: Johnson Deborah J. , Jaeger Elizabeth , Randolph Suzanne M. , Cauce Ana Mari , Ward Janie ,   and National Institute of Child Health and Human Development Early Child Care Research Network
Published: September 2003

Evidence is presented of the different cultural and ecological contexts affecting early child care for families of color. It is argued that improvements on previous research require a fundamental shift in how race, ethnicity, and culture as psychological variables are examined. Furthermore, to avoid the pitfalls and failures of previous research, new research must incorporate expanded models of child care and development in childhood. The integrative model of development for children of color proposed by Garcia Coll et al. (1996) is presented as a basis for developing more specific ecological models relevant to addressing child care issues in ethnic minority families. Finally, priority areas for future research are recommended to stimulate and enable child care researchers to adopt a more inclusive view of child care and its effects.
Theory of Mind and Relational Complexity
Authors: Andrews Glenda , Halford Graeme S. , Bunch Katie M. , Bowden Darryl , Jones Toni
Published: September 2003

Cognitive complexity and control theory and relational complexity theory attribute developmental changes in theory of mind (TOM) to complexity. In 3 studies, 3‐, 4‐, and 5‐year‐olds performed TOM tasks (false belief, appearance–reality), less complex connections (Level 1 perspective‐taking) tasks, and transformations tasks (understanding the effects of location changes and colored filters) with content similar to TOM. There were also predictor tasks at binary‐relational and ternary‐relational complexity levels, with different content. Consistent with complexity theories: (a) connections and transformations were easier and mastered earlier than TOM; (b) predictor tasks accounted for more than 80% of age‐related variance in TOM; and (c) ternary‐relational items accounted for TOM variance, before and after controlling for age and binary‐relational items. Prediction did not require hierarchically structured predictor tasks.
Effects of Earnings‐Supplement Policies on Adult Economic and Middle‐Childhood Outcomes Differ for the “Hardest to Employ”
Authors: Yoshikawa Hirokazu , Magnuson Katherine A. , Bos Johannes M. , Hsueh JoAnn
Published: September 2003

Data from the Minnesota Family Investment Program and the New Hope demonstration were used to determine whether experimental effects of antipoverty policies differ by parents' risk for nonemployment. Using propensity score analysis, increases in employment and income were largest in the harder‐to‐employ halves of both samples. However, only children in the moderately hard‐to‐employ quartiles (50th to 75th percentile) consistently showed improvements in school and behavior outcomes. The very‐hardest‐to‐employ 25% experienced decreases in school engagement, and increases in aggressive behaviors, despite substantial increases in parental employment and income. In this group, increases in maternal depression, reductions in regular family routines, and smaller increases in job stability and center‐based child care occurred. These factors may have counteracted the potential benefits of increased income on children.