bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory of electron-mobility degradation caused by roughness with long correlation length in strained-silicon devices
Authors: Kitagawa Isao , Maruizumi Takuya , Sugii Nobuyuki
Published: June 2003

To study the influence of surface roughness of a strained-Si/SiGe heterostructure on electron mobility, electron-transport properties were investigated with the ensemble Monte Carlo method. This investigation assumed an electron-motion-deviation model, in which the direction of momentum of electrons is deflected according to the roughness in the channel. It was found that (i) degradation of electron mobility appears even if the correlation length of the roughness is larger than 100 nm and (ii) significant degradation of drift velocity occurs when the direction of momentum of electrons is changed by increasing roughness amplitude. It is, therefore, concluded that decreasing the amplitude of the roughness with long correlation length is the appropriate way to increase electron mobility.
GaN nanotip pyramids formed by anisotropic etching
Authors: Ng Hock M. , Weimann Nils G. , Chowdhury Aref
Published: June 2003

We experimentally demonstrate the formation of GaN nanotip pyramids by selective and anisotropic etching of N-polar GaN in KOH solution. For samples grown with adjacent Ga- and N-polar regions on the same wafer, the KOH solution was found to selectively etch only the N-polar surface while leaving the Ga-polar surface intact. An aggregation of hexagonal pyramids with well defined {10 1̄ 1̄} facets and very sharp tips with diameters less than ∼20 nm were formed. The density of the pyramids can be controlled by varying the KOH concentration, solution temperature or the etch duration. The GaN etching activation energy is estimated to be Ea≈0.587 eV. Dense GaN pyramids with sharp tips have applications in both electronic and photonic devices.
Real-time in situ x-ray diffraction as a method to control epitaxial growth
Authors: Bader A. S. , Faschinger W. , Schumacher C. , Geurts J. , Molenkamp L. W. , Neder R. B. , Karczewski G.
Published: June 2003

We developed a real-time in situ x-ray Bragg diffraction technique for monitoring epitaxial growth. In our setup, the x-ray diffraction requirement of an extremely exact sample adjustment and an angular scan of sample and detector are circumvented by using a slightly divergent x-ray beam and observing an extremely asymmetric Bragg reflection with a multichannel detector. The angular range covered by the stationary multichannel detector corresponds nearly exactly to the qz interval of a conventional ω−2θ scan. The technique is demonstrated by monitoring the molecular-beam epitaxial growth of a ZnSe epilayer on (001)GaAs. The exposure time of each diffraction pattern is only a few seconds, which enables a real-time x-ray diffraction monitoring of the epitaxial growth process.
Synthesis of GaNxAs1−x thin films by pulsed laser melting and rapid thermal annealing of N+-implanted GaAs
Authors: Yu K. M. , Walukiewicz W. , Scarpulla M. A. , Dubon O. D. , Wu J. , Jasinski J. , Liliental-Weber Z. , Beeman J. W. , Pillai M. R. , Aziz M. J.
Published: June 2003

We present a systematic investigation on the formation of the highly mismatched alloy GaNxAs1−x using N+-implantation followed by a combination of pulsed laser melting and rapid thermal annealing. Thin films of GaNxAs1−x with x as high as 0.016 and an activation efficiency of the implanted N up to 50% have been synthesized with structural and optical properties comparable to films grown by epitaxial deposition techniques with similar substitutional N content. The effects of N+ implantation dose, laser energy fluence, and rapid thermal annealing temperature on the N incorporation as well as optical and structural properties of the GaNxAs1−x films are discussed.
Shear bands and cracking of metallic glass plates in bending
Authors: Conner R. D. , Johnson W. L. , Paton N. E. , Nix W. D.
Published: June 2003

The thickness dependence of yielding and fracture of metallic glass plates subjected to bending is considered in terms of the shear band processes responsible for these properties. We argue that the shear band spacing (and length) scales with the thickness of the plate because of strain relaxation in the vicinity of the shear band at the surface. This is consistent with recent measurements of shear band spacing versus sample size. We also argue that the shear displacements in the shear band scale with the shear band length and plate thickness, thus causing cracks to be initiated in thicker plates at smaller bending strains. This leads to fracture bending strains that decrease markedly with increasing plate thickness, consistent with recent experiments. These results suggest that amorphous metals in the form of foams might have superior ductility and toughness.
Charge-coupled device area detector for low energy electrons
Authors: Horáček Miroslav
Published: June 2003

A fast position-sensitive detector was designed for the angle- and energy-selective detection of signal electrons in the scanning low energy electron microscope (SLEEM), based on a thinned back-side directly electron-bombarded charged-coupled device (CCD) sensor (EBCCD). The principle of the SLEEM operation and the motivation for the development of the detector are explained. The electronics of the detector is described as well as the methods used for the measurement of the electron-bombarded gain and of the dark signal. The EBCCD gain of 565 for electron energy 5 keV and dynamic range 59 dB for short integration time up to 10 ms at room temperature were obtained. The energy dependence of EBCCD gain and the detection efficiency are presented for electron energy between 2 and 5 keV, and the integration time dependence of the output signals under dark conditions is given for integration time from 1 to 500 ms.
Construction of a laser scanning microscope for multiphoton excited optical fabrication
Authors: Sridhar Mallika , Basu Swarna , Scranton Victoria L. , Campagnola Paul J.
Published: June 2003

We present the construction and performance of a simple, programable, laser scanning nonlinear optical microscope for three-dimensional (3D) submicron fabrication. While the primary purpose of the microscope is for optical fabrication this instrument can also perform routine nonlinear optical imaging. The instrument consists of a commercial femtosecond laser system, an upright optical microscope, programable x–y scanning galvo mirrors, axial focus motor with an optical encoder, and single photon counting detection electronics. The mirror scanning and data acquisition are synchronous and are controlled by a single multipurpose I/O board and a graphical user interface written in a LabVIEW framework. The scanner is configured to scan a variety of geometrical patterns with user—controllable speeds, sizes, and aspect ratios, in either filled-in or perimeter patterns. Examples of 3D structures include channel-type structures for potential microfluidic applications and open boxes for encapsulation of cells for tissue engineering. Resolution in terms of imaging and fabrication are determined by fluorescence measurements of subresolution beads and scanning electron microscopy, respectively.
Extending the bandwidth of optical-tweezers interferometry
Authors: Peterman Erwin J. G. , van Dijk Meindert A. , Kapitein Lukas C. , Schmidt Christoph F.
Published: June 2003

High-resolution force and displacement measurements by laser interferometry, combined with optical tweezers in a light microscope, are frequently based on near-infrared lasers. With common silicon PN photodiodes the bandwidth of detection was found to be limited to about 5 kHz at 1064 nm laser wavelength. This is caused by the fact that silicon becomes increasingly transparent for wavelengths approaching the band gap energy, leading to the generation of charge carriers outside the depletion zone of the diode for wavelengths longer than about 850 nm. These charges have to diffuse before they can contribute to the photocurrent. In this technical note we demonstrate experimentally that the detection bandwidth can be extended to at least 100 kHz, either by using wavelengths below 850 nm, or by using different detectors at longer wavelengths: InGaAs PIN photodiodes or special-purpose fully depleted p-type silicon photodiodes. We measured the well-known power spectral density of the Brownian motion of micron-sized beads in optical tweezers and show that the optimized detectors do not cause attenuation within experimental noise. They are indeed linear enough to detect the weak inertial effects of the watery solvent on the power spectral density of the Brownian motion.
Vacuum bench for the characterization of thermoionization ion sources
Authors: Guillermier C. , Lechene C. P. , Hill J. , Hillion F.
Published: June 2003

We have designed a vacuum bench to study the parameters of thermoionization sources with the ultimate goal of obtaining high spatial resolution for biomedical applications of secondary ion mass spectrometry. In the bench, the source ionizer can be directly heated with an electron gun positioned perpendicular to the axis of the ion beam and focused with an optical system including slit lenses and a magnetic sector. The source cross over diameter is measured by forming the image of the source using an Einzel lens at a 1×magnification. The ion beam current is measured in a Faraday cup placed after a movable diaphragm. The temperature of the diverse elements of the ionizer assembly is measured through a mirror with a micropyrometer. Using the vacuum bench with a cesium carbonate source, we measured a 35 μm minimum cross over size, and we calculated a 400 A/cm2/sr maximum brightness. We obtained an intense cesium ion beam when heating the ionizer with the electron gun. The vacuum bench will be used to compare the effect of the heating mode of the ionizer (i.e., indirect by filament electron emission or direct by electron beam) on the brightness of the cesium source, and to develop a thermoionization iodine negative ion source.
Transition between two states of surface coverage and etch rate during Si etching in inductively coupled Cl2–Ar plasmas with changing mixtures
Authors: Fuller N. C. M. , Telesca Donald A. , Donnelly Vincent M. , Herman Irving P.
Published: June 2003

The etch rate and surface SiCl and SiCl2 concentrations abruptly increase and the surface Si concentration abruptly decreases as the chlorine fraction is increased above a threshold value during Si etching by an inductively coupled Cl2–Ar mixture plasma. The surface species are detected by laser desorption of the chlorinated adlayer using laser-induced fluorescence and plasma-induced emission of the desorbed species. This threshold chlorine fraction is 75% for 80 eV average ion energy, and increases with the average energy of ions incident on the surface. This unexpected observation is attributed to a phase transition between two states of surface chlorination and morphology.
Atomistic analysis of defect evolution and transient enhanced diffusion in silicon
Authors: Aboy Maria , Pelaz Lourdes , Marqués Luis A. , Enriquez L. , Barbolla Juan
Published: June 2003

Kinetic Monte Carlo simulations are used to analyze the ripening and dissolution of small Si interstitial clusters and {113} defects, and its influence on transient enhanced diffusion of dopants in silicon. The evolution of Si interstitial defects is studied in terms of the probabilities of emitted Si interstitials being recaptured by other defects or in turn being annihilated at the surface. These two probabilities are related to the average distance among defects and their distance to the surface, respectively. During the initial stages of the defect ripening, when the defect concentration is high enough and the distance among them is small, Si interstitials are mostly exchanged among defects with a minimal loss of them to the surface. Only when defects grow to large sizes and their concentration decreases, the loss of Si interstitials through diffusion to the surface prevails, causing their dissolution. The presence of large and stable defects near the surface is also possible when the implant energy is low—small distance to the surface—but the dose is high enough—even smaller distance among defects. The exchange of Si interstitials among defects sets a interstitial supersaturation responsible for the temporary enhancement of the diffusivity of interstitial diffusing dopants. The transitory feature of the enhancement is well correlated to the extinction of the Si interstitial defects.
Piezoelectric strain in lead zirconate titante ceramics as a function of electric field, frequency, and dc bias
Authors: Masys A. J. , Ren W. , Yang G. , Mukherjee B. K.
Published: June 2003

We have investigated the electromechanical response of piezoelectric ceramics as a function of the amplitude and frequency of large electric fields and studied the effects of dc bias fields. In order to characterize the materials under these conditions, a ZMI 2000 laser interferometer system from Zygo Corp. has been installed and modified to directly measure the strains of ferroelectric ceramics. This system uses a heterodyne detection technique and has the advantages of phase detection, wide bandwidth, high stability, and easy optical alignment. Our experiment has been used to determine the strain of lead zirconate titanate (PZT) ceramics as a function of electric fields and as a function of frequency in the low frequency range. From these measurements the piezoelectric coefficients d33, d31, and d15 have been determined as a function of applied field and frequency. In addition the dependence of the piezoelectric coefficients under an applied dc bias field has been studied under quasistatic and under resonance conditions. Some of our measurements have provided evidence of the time dependence of the piezoelectric response. Results on a range of soft and hard PZT ceramics manufactured by EDO Corp. are presented. These results are discussed within the context of extrinsic contributions to the piezoelectric response.
Enhanced electroluminescence in silicon-on-insulator metal–oxide–semiconductor transistors with thin silicon layer
Authors: Karsenty Avi , Sa’ar Amir , Ben-Yosef Nissim , Shappir Joseph
Published: June 2003

Silicon-on-insulator (SOI) and bulk metal–oxide–semiconductor (MOS) transistors were fabricated simultaneously and tested electrically and optically at room temperature. The electroluminescence (EL) spectrum has been measured in both types of devices. A visible emitted radiation was observed when both devices were operated in the avalanche breakdown mode. In the case of SOI device, five different peaks at a photon energy of 2.31, 2.06, 1.81, 1.63, and 1.50 eV were observed. The regular spacing between the measured peaks indicates cavity effects due to the various layers of the SOI MOS transistor structure. The thin silicon layer thickness of 400 Å seems to be responsible for the factor of about 16 in the EL intensity of the SOI device as compared to the bulk device.
Decoupling between rare-earth moment and transition metal moment in NdCo12−xVx compounds
Authors: Liu W. F. , Rao G. H. , Ouyang Z. W. , Yang H. F. , Liu G. Y. , Feng X. M. , Chang H. , Liang J. K.
Published: June 2003

Single-phase compounds NdCo12−xVx (x=2.2–2.6) crystallizing in the tetragonal ThMn12 structure with space group I4/mmm are synthesized. The lattice parameters a and c increase linearly with increasing V content. The Curie temperature of the compounds shows a linear decrease from 309 K for x=2.2 to 147 K for x=2.6. A domain-wall pinning phenomenon is observed in all of the compounds. It is intriguing that the Nd ions seem to make no contribution to the total moment of the compounds in an applied magnetic field up to 50 kOe. A further increase of the applied field induces a moment of a Nd sublattice that ferromagnetically couples with the moment of a Co sublattice. The instability of the Nd moment in NdCo12−xVx compounds can be well understood by the local environment effect.
IrO
2
Schottky contact on n-type 4H-SiC
Authors: Han Sang Youn , Jang Ho Won , Lee Jong-Lam
Published: June 2003

A thermally stable IrO2 Schottky contact on n-type 4H-SiC was achieved by annealing an Ir contact under O2 ambient. The IrO2 contact exhibited a high Schottky barrier height of 2.22 eV and low reverse leakage current. Little degradation in Schottky barrier height was observed even after annealing at 450 °C for 24 h under atmospheric air. The oxidation annealing transformed the Ir layer into IrO2, resulting in the increase in the work function of the contact layer. Simultaneously, Si atoms diffused out, leaving the Si vacancy below the contact. These played a role in forming a thermally stable Schottky contact with a high Schottky barrier height.
Acoustic properties of (Pb0.9La0.1)(Zr0.65Ti0.35)O3 relaxor ferroelectric ceramics studied by Brillouin scattering
Authors: Shabbir Ghulam , Ko Jae-Hyeon , Kojima Seiji , Yin Qing-Rui
Published: June 2003

Acoustic properties of PLZT 10/65/35 relaxor ferroelectric ceramic samples have been studied by high resolution Brillouin scattering technique in the temperature range from 90 to 800 K. The Brillouin frequency shift and the elastic moduli, related to the LA and TA phonon modes, show a broad softening on cooling towards the dielectric maximum temperature Tm. The hypersonic damping shows broad maxima at 328 K, which we attribute to order parameter fluctuations. The softening in the elastic moduli L, E, and G is maximum in the temperature range from 300 to 340 K. The temperature dependence of maximum relaxation time τmax reveals good correlation between dielectric and Brillouin scattering data.
The Store-operated Calcium Entry Pathways in Human Carcinoma A431 Cells
Authors: Gusev Konstantin , Glouchankova Lyuba , Zubov Alexander , Kaznacheyeva Elena , Wang Zhengnan , Bezprozvanny Ilya , Mozhayeva Galina N.
Published: June 2003

Activation of phospholipase C (PLC)-mediated signaling pathways in nonexcitable cells causes the release of Ca2+ from intracellular Ca2+ stores and activation of Ca2+ influx across the plasma membrane. Two types of Ca2+ channels, highly Ca2+–selective ICRAC and moderately Ca2+–selective ISOC, support store-operated Ca2+ entry process. In previous patch-clamp experiments with a human carcinoma A431 cell line we described store-operated Imin/ICRACL plasma membrane Ca2+ influx channels. In the present paper we use whole-cell and single-channel recordings to further characterize store-operated Ca2+ influx pathways in A431 cells. We discovered that (a) ICRAC and ISOC are present in A431 cells; (b) ICRAC currents are highly selective for divalent cations and fully activate within 150 s after initiation of Ca2+ store depletion; (c) ISOC currents are moderately selective for divalent cations (PBa/PCs = 14.5) and require at least 300 s for full activation; (d) ICRAC and ISOC currents are activated by PLC-coupled receptor agonists; (e) ISOC currents are supported by Imin/ICRACL channels that display 8.5–10 pS conductance for sodium; (f) ICRAC single channel conductance for sodium is estimated at 0.9 pS by the noise analysis; (g) Imin/ICRACL channels are activated in excised patches by an amino-terminal fragment of InsP3R1 (InsP3R1N); and (h) InsP3 binding to InsP3R1N is necessary for activation of Imin/ICRACL channels. Our findings provide novel information about store-operated Ca2+ influx pathways in A431 cells.
A survey of the Predictive Toxicology Challenge 2000–2001
Authors: Helma C. , Kramer S.
Published: June 2003

Motivation: The Predictive Toxicology Challenge (PTC) was initiated to stimulate the development of advanced techniques for predictive toxicology models. The goal of this challenge was to compare different approaches for the prediction of rodent carcinogenicity, based on the experimental results of the US National Toxicology Program (NTP).

Results: 111 sets of predictions for 185 compounds have been evaluated on quantitative and qualitative scales to select the most predictive models and those with the highest toxicological relevance. The accuracy of the submitted predictions was between 25 and 79 %. An evaluation of the most accurate models by toxicological experts showed, that it is still hard for domain experts to interpret the submitted models and to put them into relation with toxicological knowledge.

Availability: PTC details and data can be found at: http://www.predictive-toxicology.org/ptc/

Contact: helma@informatik.uni-freiburg.de

* To whom correspondence should be addressed.

† Present address: Institute for Computer Science, Technical University Munich, D-85748, Garching, Germany.
GeneComber: combining outputs of gene prediction programs for
improved results
Authors: Shah Sohrab P. , McVicker Graham P. , Mackworth Alan K. , Rogic Sanja , Ouellette B. F. Francis
Published: June 2003

Summary: We recently demonstrated that combining the output from Genscan and HMMgene can provide increased accuracy of gene predictions. We have created a robust software system that runs algorithms previously described on DNA sequences and provides a public web interface to the system for use by the biological community worldwide. The GeneComber system performs ab initio gene prediction by first taking a user inputted DNA sequence and running Genscan and HMMgene. The outputs of Genscan and HMMgene are then integrated using the EUI, GI and EUI_frame algorithms. All results are then stored into a relational database management system (RDBMS) and can then be retrieved through a web interface. The web interface provides a unified view of the GeneComber predictions by graphically overlaying outputs from Genscan, HMMgene, EUI, GI and EUI_frame. Outputs can also be retrieved in general feature format (GFF) or FASTA format. The software is written in the Perl programming language and is both dependent on and interoperable with the Bioperl toolkit. It includes high-level application programming interfaces (APIs) to run Genscan, HMMgene and a database API to insert prediction results into an RDBMS. The APIs are assembled into the genecomber script which is executed by the web interface or can be run directly from the Unix command line. The web interface is written in PHP and is structured so as to be easily modified for viewing data from any database that stores gene structures.

Availability: The GeneComber public web interface and supplementary information is located at http://bioinformatics.ubc.ca/genecomber The source code is released under the GNU General Public License and is available at ftp://ftp.bioinformatics.ubc.ca/pub/genecomber/software

Contact: francis@bioinformatics.ubc.ca

* To whom correspondence should be addressed.

† Present address: EMBL - European Bioinformatics Institute, Cambridge CB10 1SD, UK.
Archiving the Web – some legal aspects
Authors: Kavćić‐Ćolić Alenka
Published: June 2003

Technological developments have changed the concepts of publication, reproduction and distribution. However, legislation, and in particular the Legal Deposit Law has not adjusted to these changes – it is very restrictive in the sense of protecting the rights of authors of electronic publications. National libraries and national archival institutions, being aware of their important role in preserving the written and spoken cultural heritage, try to find different legal ways to live up to these responsibilities. This paper presents some legal aspects of archiving Web pages, examines the harvesting of Web pages, provision of public access to pages, and their long‐term preservation.
The origins of value‐for‐money auditing: the Baltimore and Ohio Railroad: 1827‐1830
Authors: Flesher Dale L. , Samson William D. , Previts Gary John
Published: June 2003

Evidence of audit committee activity in the formative years of the Baltimore & Ohio (B&O) Railroad indicates that control and reporting activity developed long before the existence of regulatory mandate or the external auditing function. This is the earliest example of such an organized and continuing activity in American business history. With no previous business experience to model this enterprise, the organizers of the corporation put in place an audit committee of directors as a control device to safeguard assets and ensure proper handling of cash receipts and disbursements. Research into primary materials establishes that the committee not only performed regular routine audits of the “treasurer’s report,” but also identified and addressed critical problems of control and payment weaknesses. The discovery of the function of value‐for‐money (VFM) auditing by a committee of directors establishes historical context for today’s audit process and audit committee. Because the B&O was such an important entity, it influenced other railroads; and the railroad industry, in turn, greatly influenced the development of modern American businesses during the Industrial Revolution.
Obtaining Fractals in a Fabry-Perot Interferometer
Authors: Gascón F. , Galván A.
Published: June 2003

The aim of this paper is to prove that, with a reflection coefficient of R<2-1/2, the series expressing the amplitude of the light beam transmitted by a Fabry-Perot interferometer, can be a fractal series. It is assumed as a starting point that the incident beam is maintained for an indefinite time and that its amplitude is constant.
Chaos in the Galactic Dynamics
Authors: Tomaschitz Roman
Published: June 2003

An elementary survey of cosmic chaos, its origins, and its physical impact in an open and multiply connected universe is given. A new type of cosmic evolution by global metrical deformations, unpredicted by Einstein's equations, is pointed out. The uniformity and the inhomogeneities of the galactic background are discussed in this context. There is a finite region in the open 3-space in which the galactic world-lines are chaotic, and the mixing taking place in this chaotic nucleus of the universe provides a mechanism to create the galactic equidistribution.

We review in a completely untechnical way how global metrical deformations of space-time cause particle creation in quantum fields, and induce angular fluctuations in the temperature of the cosmic microwave background radiation. They can generate topology changes without distorting the constant curvature of the 3-space. The micro-topology causes parity violation (i.e., a violation of the space-reflection symmetry) by self-interference.
Work-Related Tardiness: Lateness Incident Distribution and Long-Range Correlations
Authors: Dishon-Berkovits M. , Berkovits R.
Published: June 2003

The probability distribution of the length of time which is lost to an organization due to an employee being late arrival at work, as well as the correlation between the time lost in different incidents and on different dates is empirically studied. Computerized arrival records of the employees in the headquarters of a large industrial firm were used. It is shown that the probability of the time lost in a single late arrival follows a power law with an exponent α ~ 1 for lateness incidents longer than a few minutes but significantly shorter than the duration of a shift. It is also shown that the autocorrelations for time series composed of lateness incidents of different employees on different dates show a characteristic 1/fβ with β = 0.55 power spectrum. These results are a strong evidence for a kind of "critical dynamics" underlying the tardiness problem. On the other hand, the distribution of the total time lost in the organization due to late arrivals on a particular day is Gaussian.
What works in drug addiction?
Authors: Luty Jason
Published: June 2003

Treatment of illicit drug dependence typically involves a combination of pharmacotherapy and psychosocial interventions. Efficacy research supports methadone maintenance in opiate dependence. There is less evidence to support buprenorphine (an opiate receptor partial agonist), lofexidine (an α2-adrenoreceptor agonist) and naltrexone (an opiate receptor antagonist). Evidence for the effectiveness of detoxification, which one of the most widely used treatments, is poor. Of the psychosocial interventions, reasonable evidence exists for the effectiveness of motivational interviewing. Other psychosocial treatments have rarely been compared with no or minimal contact conditions in randomised trials, and their reported effectiveness is often weak. Residential treatments are not demonstrably more effective than community programmes.
Liaison psychiatry or psychological medicine?
Authors: Lloyd Geoffrey G. , Mayou Richard A.
Published: June 2003

Liaison psychiatry has been recognised in many countries as a special interest or sub-speciality of psychiatry concerned with the management of general hospital patients with psychological problems. However, despite increasing awareness of the emotional and behavioural aspects of illness, it has yet to achieve substantial influence within psychiatry and, more importantly, has had only modest effects on the delivery of medical care by physicians and other specialists. Recognition of its potential by planners and commissioners has been disappointing. Regrettably, in the UK and elsewhere, recent changes in the organisation of health care could hinder its development. This paper argues that in order to make substantial progress there is a compelling need to solve a fundamental obstacle – the separation between psychiatric and general medical care. This requires:

(a) convincing the psychiatric profession that consultation-liaison is a distinct sub-speciality;

(b) continuing efforts by liaison psychiatrists to define their special expertise and to demonstrate that their services are effective and acceptable to medical colleagues and to patients;

(c) persuading those who organise health care that liaison psychiatry services need to be provided and administered as an integral component of comprehensive medical care.
The politics of a new Mental Health Act
Authors: Moncrieff Joanna
Published: June 2003

Recent proposals for reforming the Mental Health Act show that the Government is keen to increase restrictions on current psychiatric patients and to extend the boundaries of psychiatric legislation. The proposals contained in the new Mental Health Bill (Department of Health, 2002) seem destined to make it easier to be subject to compulsory powers and more difficult to be rid of them.
Randomized, Placebo-Controlled Trial of Combined Pentoxifylline and Tocopherol for Regression of Superficial Radiation-Induced Fibrosis
Authors: Delanian Sylvie , Porcher Raphael , Balla-Mekias Saida , Lefaix Jean-Louis
Published: June 2003

Purpose: Radiation-induced fibrosis (RIF) is a rare morbid complication of radiotherapy, without an established method of management. RIF treatment with a combination of pentoxifylline (PTX) and alpha-tocopherol (vitamin E; Vit E) was recently prompted by the good results of a clinical trial and an animal study. The present double-blind, placebo-controlled, monocentric study was designed to assess the efficacy of this combination in treating RIF sequelae.

Patients and Methods: Twenty-four eligible women with 29 RIF areas involving the skin and underlying tissues were enrolled from December 1998 to April 2000. These patients, previously irradiated for breast cancer, were randomly assigned to four balanced treatment groups: (A) 800 mg/d of PTX and 1,000 U/d of Vit E; (B) PTX plus placebo; (C) placebo plus Vit E; and (D) placebo-placebo. The main end point measure was the relative regression of measurable RIF surface after 6 months of treatment. Assessment was completed by depth (with ultrasonography) and associated symptom measures.

Results: Twenty-two patients with 27 RIF areas were analyzed at 6 months. Mean RIF surface regression was significant with combined PTX/Vit E versus double placebo (60% ± 10% v 43% ± 17%; P = .038). The median slope for the speed of RIF surface area and volume regression was significantly higher for group A than groups B, C, and D. All treatments were well tolerated.

Conclusion: Six months’ treatment of combined PTX/Vit E can significantly reduce superficial RIF. Synergism between PTX and Vit E is likely, as treatment with each drug alone is ineffective, but these results require confirmation in larger series.
Survival and Neurologic Outcomes in a Randomized Trial of Motexafin Gadolinium and Whole-Brain Radiation Therapy in Brain Metastases
Authors: Mehta Minesh P. , Rodrigus Patrick , Terhaard C.H.J. , Rao Aroor , Suh John , Roa Wilson , Souhami Luis , Bezjak Andrea , Leibenhaut Mark , Komaki Ritsuko , Schultz Christopher , Timmerman Robert , Curran Walter , Smith Jennifer , Phan See-Chun , Miller Richard A. , Renschler Markus F.
Published: June 2003

Purpose: This phase III randomized trial evaluated survival as well as neurologic and neurocognitive function in patients with brain metastases from solid tumors receiving whole-brain radiation therapy (WBRT) with or without motexafin gadolinium (MGd).

Patients and Methods: Patients were randomly assigned to 30 Gy of WBRT ± 5 mg/kg/d MGd. Survival and time to neurologic progression determined by a blinded events review committee (ERC) were coprimary end points. Standardized investigator neurologic assessment and neurocognitive testing were evaluated.

Results: Four hundred one (251 non–small-cell lung cancer) patients were enrolled. There was no significant difference by treatment arm in survival (median, 5.2 months for MGd v 4.9 months for WBRT; P = .48) or time to neurologic progression (median, 9.5 months for MGd v 8.3 months for WBRT; P = .95). Treatment with MGd improved time to neurologic progression in patients with lung cancer (median, not reached for MGd v 7.4 months for WBRT; P = .048, unadjusted). By investigator, MGd improved time to neurologic progression in all patients (median, 4.3 months for MGd v 3.8 months for WBRT; P = .018) and in lung cancer patients (median, 5.5 months for MGd v 3.7 months for WBRT; P = .025). MGd improved neurocognitive function in lung cancer patients.

Conclusion: The overall results did not demonstrate significant differences by treatment arm for survival and ERC time to neurologic progression. Investigator neurologic assessments demonstrated an MGd treatment benefit in all patients. In lung cancer patients, ERC- and investigator-determined time to neurologic progression demonstrated an MGd treatment benefit. MGd may improve time to neurologic and neurocognitive progression in lung cancer.
TheCaenorhabditis elegans spalt-like genesem-4restricts touch cell fate by repressing the selector Hox geneegl-5and the effector genemec-3
Authors: Toker Anne S. , Teng Yingqi , Ferreira Henrique B. , Emmons Scott W. , Chalfie Martin
Published: June 2003

Members of the spalt (sal) gene family encode zinc-finger proteins that are putative tumor suppressors and regulate anteroposterior (AP) patterning,cellular identity, and, possibly, cell cycle progression. The mechanism through which sal genes carry out these functions is unclear. The Caenorhabditis elegans sal gene sem-4 controls the fate of several different cell types, including neurons, muscle and hypodermis. Mutation of sem-4 transforms particular tail neurons into touch-neuron-like cells. In wild-type C. elegans, six touch receptor neurons mediate the response of the worm to gentle touch. All six touch neurons normally express the LIM homeobox gene mec-3. A subset, the two PLM cells, also express the Hox gene egl-5, an Abdominal-B homolog, which we find is required for correct mec-3 expression in these cells. The abnormal touch-neuron-like-cells in sem-4 animals express mec-3; we show that a subset also express egl-5.

We report: (1) that ectopic expression of sem-4 in normal touch cells represses mec-3 expression and reduces touch cell function; (2)that egl-5 expression is required for both the fate of normal PLM touch neurons in wild-type animals and the fate of a subset of abnormal touch neurons in sem-4 animals, and (3) that SEM-4 specifically binds a shared motif in the mec-3 and egl-5 promoters that mediates repression of these genes in cells in the tail. We conclude that sem-4 represses egl-5 and mec-3 through direct interaction with regulatory sequences in the promoters of these genes, that sem-4 indirectly modulates mec-3 expression through its repression of egl-5 and that this negative regulation is required for proper determination of neuronal fates. We suggest that the mechanism and targets of regulation by sem-4 are conserved throughout the sal gene family: other sal genes might regulate patterning and cellular identity through direct repression of Hox selector genes and effector genes.
A retrospective clonal analysis of the myocardium reveals two phases of clonal growth in the developing mouse heart
Authors: Meilhac Sigolène M. , Kelly Robert G. , Rocancourt Didier , Eloy-Trinquet Sophie , Nicolas Jean-François , Buckingham Margaret E.
Published: June 2003

Key molecules which regulate the formation of the heart have been identified; however, the mechanism of cardiac morphogenesis remains poorly understood at the cellular level. We have adopted a genetic approach, which permits retrospective clonal analysis of myocardial cells in the mouse embryo,based on the targeting of an nlaacZ reporter to the α-cardiac actin gene. A rare intragenic recombination event leads to a clone ofβ-galactosidase-positive myocardial cells. Analysis of clones at different developmental stages demonstrates that myocardial cells and their precursors follow a proliferative mode of growth, rather than a stem cell mode, with an initial dispersive phase, followed by coherent cell growth. Clusters of cells are dispersed along the venous-arterial axis of the heart tube. Coherent growth is oriented locally, with a main axis, which corresponds to the elongation of the cluster, and rows of cells, which form secondary axes. The angle between the primary and secondary axes varies, indicating independent events of growth orientation. At later stages, as the ventricular wall thickens, wedge shaped clusters traverse the wall and contain rows of cells at a progressive angle to each other. The cellular organisation of the myocardium appears to prefigure myofibre architecture. We discuss how the characteristics of myocardial cell growth, which we describe, underlie the formation of the heart tube and its subsequent regionalised expansion.
The Upper Temperature Limit in Cooperative Assembly of Ordered Mesoporous Materials
Authors: Yuan Minjia , Tang Jiawei , Yu Chengzhong , Chen Yinghua , Tu Bo , Zhao Dongyuan
Published: June 2003

Several examples for high temperature (95 °C, higher than the cloud point of pure surfactant) synthesis of highly ordered hexagonal mesoporous silica structures by employing triblock copolymers such as P65 (EO20PO30EO20) as structure-directing agents have been presented. Such understanding may increase the range of surfactants and the temperature regime under which ordered mesoporous materials can be cooperatively assembled.
Distributional issues in check‐off funded programs
Authors: Alston Julian M. , Freebairn John W. , James Jennifer S.
Published: June 2003

Agricultural commodity taxes, called check‐offs, are used to finance promotion, research, and other activities that can be regarded as industry collective goods. The collection of the check‐offs and the programs they are used to fund have implications for the welfare of consumers, other producers, and taxpayers in addition to their effects on those producers who are allowed to vote in the procedures for authorizing the programs. As well as simple fairness or equity considerations, such shifting of the incidence of benefits and costs to others can lead to a divergence between producer and national optimal choices, and hence efficiency losses. From a public policy perspective, then, the implications for others ought to be considered in the design of the enabling legislation, in the evaluation of the specific programs, and in the rules governing the behavior of the agricultural producer groups engaged in commodity check‐off programs. [EconLit citations: Q180, Q130, H420]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 277–287, 2003.
Distributional effects of generic dairy advertising throughout the marketing channel
Authors: Kaiser Harry M. , Schmit Todd M.
Published: June 2003

If generic advertising is effective at increasing the demand for the advertised product, then there will not only be direct effects on the sponsors of the advertising, but also indirect effects on other market participants. This article addresses two such distributional issues using the U.S. dairy industry as a case study. First, how are fluid milk and cheese processors impacted by cheese and milk advertising conducted by farmers? We find that the welfare of both processor classes is improved due to the dairy farmer advertising program for fluid milk and cheese products. Second, how are fluid milk (or cheese) processors impacted by the other product's farmer‐funded advertising? As expected, own‐product advertising increased equilibrium output levels, while cross‐advertising impacts slightly reduced supply levels. Generic advertising, regardless of product, positively affected fluid milk processor gross margins, while increases in cheese advertising reduced the price margin for cheese processors. In general, own‐product advertising had larger price margin impacts for fluid milk processors, while cheese processors benefited more from larger supply gains. These larger supply effects translated further into larger increases in raw milk costs tightening cheese price margins. Because changes in cheese supplies affect both Class I and Class III prices, input prices to processors are affected relatively more by increases in cheese advertising, as opposed to fluid milk advertising. The relatively larger gains in output prices, combined with lower relative increases in input class prices contributed to higher producer welfare impacts for fluid milk processors than cheese processors when confronted with equivalent increases in their own‐product advertising. [EconLit citations: Q130, Q180]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 289–300, 2003.
Distribution of gains from research and promotion in the presence of market power
Authors: Wohlgenant Michael K. , Piggott Nicholas E.
Published: June 2003

This article evaluates how marginal returns to producers from promotion and research are affected when market intermediaries have market power in the retail market. Using an equilibrium displacement model, the relative importance of market power is evaluated for a “typical” food‐processing industry, and the empirical analysis focuses on how much profits from advertising, off‐farm research, and farm research are affected by a one dollar increase in check‐off funds, assuming equal efficiency in funds spent at each level of the marketing channel. The empirical analysis systematically considers alternative values of the underlying structural parameters of the model using Monte Carlo simulations to generate confidence intervals of marginal returns from each alternative use of the funds. Important findings are that the results with market power are indistinguishable from those obtained under pure competition and the results are most affected by input substitutability. [EconLit citations: L660]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 301–314, 2003.
Distributional effects of commodity promotion programs by type of producer
Authors: Chung Chanjin , Kaiser Harry M.
Published: June 2003

This study provides a theoretical background for the firm‐level analysis on the distributional effects of commodity promotion programs. The conceptual basis of this approach is that firms differ due to differences in possessing endowments of fixed factors, and net returns to firms can be viewed as rents accruing to these factors. Therefore, the marginal return from an increase in demand due to a successful generic promotion programs may not be the same across firms because firms do not have the same level of fixed factors. The result of our analysis indicates that producers may not equally benefit from the collectively funded programs. Our marginal profit analysis indicates that a producer‐financed promotion program may have greater benefits for producers with more endowed fixed factors than those with less endowed fixed factors.[EconLit citations: M370 and Q130]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 325–332, 2003.
Study on surface modification by surface‐modifying macromolecules and its applications in membrane‐separation processes
Authors: Khayet M. , Suk D. E. , Narbaitz R. M. , Santerre J. P. , Matsuura T.
Published: June 2003

Surface‐modifying macromolecules (SMMs) are oligomeric fluoropolymers synthesized by polyurethane chemistry and tailored with fluorinated end groups. In the literature, several formulations of SMMs have been developed and blended with base polymers of polyurethanes and polyethersulfone for surface modification. It has been shown that SMMs migrate to the surface and the fluorine end groups orient themselves toward the air–polymer interface, reducing the surface energy of the hydrophilic base polymer to values close to that of polytetrafluoroethylene (Teflon). Because only a small amount of SMMs was needed, the bulk properties of the base polymer remained relatively unchanged. The properties of the SMM polymers were characterized, including molecular weights, elemental analysis, and thermal transitions. The morphology and surface properties of the SMM‐modified and unmodified membranes were assessed. The use of SMMs has been tested for use in ultrafiltration, pervaporation, and biomedical applications. SMM‐modified membranes offer advantages over unmodified membranes and the use of SMMs will continue to be the focus of future studies. This study reviews the recent development of surface‐modifying macromolecules (SMMs) and SMM‐blended membranes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2902–2916, 2003
Preparation and characterization of benzylated sisal fibers
Authors: Ferreira Fábio C. , Curvelo Antonio A. S. , Mattoso Luiz H. C.
Published: June 2003

Sisal fibers were benzylated under different conditions and were characterized with infrared spectroscopy, X‐ray diffraction, thermal analysis, and scanning electron microscopy. The benzylation reaction was monitored by the mass gain as a function of the reaction time. In the first stage, there was a mass loss associated with the loss of lignin and polyoses from the raw fiber, which was accompanied by an increase in mass due to benzyl incorporation. When fiber delignification was carried out before benzylation, the mass gain curves of the benzylation reaction presented no initial mass loss and a much higher mass gain. Benzylation promoted several morphological changes: (1) the loss of the parenchyma cells, (2) the defibrillation of the technical fibers into ultimate fibers, (3) the microdefibrillation of the ultimate fibers, and (4) benzyl incorporation. The crystallinity of the fibers decreased with benzylation, as observed by X‐ray diffraction. The thermal stability of the fibers varied according to the treatment used. Other changes promoted in the fibers by chemical modification were examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2957–2965, 2003