bluuebunny/crossref_metadata_2025 huggingface dataset:
CD4+CD25+Regulatory T Cells Suppress CD4+T-Cell Function and Inhibit the Development ofPlasmodium berghei-Specific TH1 Responses Involved in Cerebral Malaria Pathogenesis
Authors: Nie Catherine Q. , Bernard Nicholas J. , Schofield Louis , Hansen Diana S.
Published: February 2007

The infection of mice withPlasmodium bergheiANKA constitutes the best available mouse model for humanPlasmodium falciparum-mediated cerebral malaria, a devastating neurological syndrome that kills nearly 2.5 million people every year. Experimental data suggest that cerebral disease results from the sequestration of parasitized erythrocytes within brain blood vessels, which is exacerbated by host proinflammatory responses mediated by cytokines and effector cells including T lymphocytes. Here, T cell responses toP. bergheiANKA were analyzed in cerebral malaria-resistant and -susceptible mouse strains. CD4+T-cell proliferation and interleukin-2 (IL-2) production in response to parasite-specific and polyclonal stimuli were strongly inhibited in cerebral malaria-resistant mice. In vitro and in vivo depletion of CD4+CD25+regulatory T (Treg) cells significantly reversed the inhibition of CD4+T-cell proliferation and IL-2 production, indicating that this cell population contributes to the suppression of T-cell function during malaria. Moreover, in vivo depletion of Tregcells prevented the development of parasite-specific TH1 cells involved in the induction of cerebral malaria during a secondary parasitic challenge, demonstrating a regulatory role for this cell population in the control of pathogenic responses leading to fatal disease.
ON THE BÊTA-ELLIPTIC MODEL FOR THE CONTROL OF THE HUMAN ARM MOVEMENT
Authors: BEZINE HALA , KEFI MEHDI , ALIMI ADEL M.
Published: February 2007

This article describes a kinematic theory, called the Bêta-elliptic model, for generating handwriting movements. The model consists of a sequential controller producing a curvilinear velocity approximated by Bêta profiles. This earlier interacts with a trajectory generator to provide elliptic strokes. As an application to our model, we consider a redundant seven degrees of freedom manipulator having a kinematic structure similar to that of a human arm. We treat to demonstrate how the Bêta-elliptic theory enables a simple motor program to generate complex curvilinear movements that have many of the properties that humans exhibit when they produce cursive script.

Bêta-elliptic properties enable a simple control strategy to generate complex handwritten script if the hand model contains redundant degrees of freedom. Here, we restrict our analysis to a total of seven degrees of freedom from the shoulder to the wrist. The proposed controller launches transient commands to independent hand synergies at times when the hand begins to move. The Bêta-elliptic model transforms these synergy commands into smooth curvilinear velocity fitted by Bêta profiles among temporally overlapping synergetic units of trajectory approximated by elliptic strokes. In experiments, and at first sight, good phenomenological agreement with natural movement trajectories is found.
AUTOMATIC ALLOGRAPH MATCHING IN FORENSIC WRITER IDENTIFICATION
Authors: NIELS RALPH , VUURPIJL LOUIS , SCHOMAKER LAMBERT
Published: February 2007

A well-established task in forensic writer identification focuses on the comparison of prototypical character shapes (allographs) present in handwriting. In order for a computer to perform this task convincingly, it should yield results that are plausible and understandable to the human expert. Trajectory matching is a well-known method to compare two allographs. This paper assesses a promising technique for so-called human-congruous trajectory matching, called Dynamic Time Warping (DTW). In the first part of the paper, an experiment is described that shows that DTW yields results that correspond to the expectations of human users. Since DTW requires the dynamics of the handwritten trace, the "online" dynamic allograph trajectories need to be extracted from the "offline" scanned documents. In the second part of the paper, an automatic procedure to perform this task is described. Images were generated from a large online dataset that provides the true trajectories. This allows for a quantitative assessment of the trajectory extraction techniques rather than a qualitative discussion of a small number of examples. Our results show that DTW can significantly improve the results from trajectory extraction when compared to traditional techniques.
HANDWRITING RECOGNITION OF WHITEBOARD NOTES — STUDYING THE INFLUENCE OF TRAINING SET SIZE AND TYPE
Authors: LIWICKI MARCUS , BUNKE HORST
Published: February 2007

This paper presents a system for the recognition of online whiteboard notes. Notes written on a whiteboard is a new modality in handwriting recognition research that has received relatively little attention in the past. For the recognition we use an offline HMM-recognizer, which is supplemented with methods for processing the online data and generating offline images. The system consists of six main modules: online preprocessing, transformation of online to offline data, offline preprocessing, feature extraction, classification and post-processing. The recognition rate of our basic recognizer in a writer independent experiment is 59.5%. By applying state-of-the-art methods, such as optimizing the number of states and Gaussian components, and by including a language model we could achieve a statistically significant increase of the recognition rate to 64.3%. To further improve the system performance we increased the size of the training set. For that we investigated two different strategies. First, we used another existing database of offline handwritten text. Second, we used a recently collected whiteboard database, called the IAM-OnDB. By means of these strategies the recognition rate could be further increased up to 68.5%.
HANDWRITTEN CHARACTER RECOGNITION USING NONSYMMETRICAL PERCEPTUAL ZONING
Authors: FREITAS CINTHIA O. A. , OLIVEIRA LUIZ S. , BORTOLOZZI FLÁVIO , AIRES SIMONE B. K.
Published: February 2007

In this paper we present an alternative strategy to define zoning for handwriting recognition, which is based on nonsymmetrical perceptual zoning. The idea is to extract some knowledge from the confusion matrices in order to make the zoning process less empirical. The feature set considered in this work is based on concavities/convexities deficiencies, which are obtained by labeling the background pixels of the input image. To better assess the nonsymmetrical zoning we carried out experiments using four different zonings strategies. Experiments show that the nonsymmetrical zoning could be considered as a tool to build more reliable handwriting recognition systems.
PARTICLE-PARTICLE HOLE-HOLE TDA – AND BEYOND – FOR THE NUCLEAR PAIRING HAMILTONIAN
Authors: MOLIQUE HERVÉ , DUDEK JERZY
Published: February 2007

A comparison of different seniority zero solutions to the picket-fence model for the nuclear pairing hamiltonian problem is performed. These solutions are calculated, in the normal regime, within the self-consistent Random Phase Approximation (SCRPA) and various simplifications of this formalism, and also with the Tamm-Dancoff approach in the particle-particle-hole-hole channel (pphh-TDA). The latter formalism represents a first approximation to the earlier developped so-called P-Symmetric Many-Body method (PSY-MB). In the superfluid regime, the solutions are compared with the BCS results. By comparing the results with the exact ones, obtained by the Richardson method, it is shown that the PSY-MB method provides a powerful tool in solving the problem with good accuracy both in the normal and the superfluid regime, for single-particle space sizes adapted to typical nuclear structure calculations.
PAIRING PROPERTIES OF SUPERHEAVY NUCLEI
Authors: STASZCZAK A. , DOBACZEWSKI J. , NAZAREWICZ W.
Published: February 2007

Pairing properties of even-even superheavy N = 184 isotones are studied within the Skyrme-Hartree-Fock+BCS approach. In the particle-hole channel we take the Skyrme energy density functional SLy4, while in the particle-particle channel we employ the seniority pairing force and zero-range δ-interactions with different forms of density dependence. We conclude that the calculated static fission trajectories weakly depend on the specific form of the δ-pairing interaction. We also investigate the impact of triaxiality on the inner fission barrier and find a rather strong Z dependence of the effect.
ANGULAR-MOMENTUM PROJECTION OF CRANKED SYMMETRY-UNRESTRICTED SLATER DETERMINANTS
Authors: ZDUŃCZUK H. , DOBACZEWSKI J. , SATUŁA W.
Published: February 2007

We report on development of a new feature of the code HFODD, allowing for the angular-momentum projection of cranked symmetry-unrestricted Slater determinants. After a brief overview of the main theoretical building blocks and formalism, we present several preliminary applications. In particular, we discuss the case of a well-deformed rotational band in 156 Gd , and we show the emergence of uncompensated poles in the overlap kernels calculated in an odd-A nucleus 155 Eu .
ANGULAR MOMENTA OF NEAR-SPHERICAL FISSION FRAGMENTS
Authors: GÖNNENWEIN F. , TSEKHANOVICH I. , RUBCHENYA V.
Published: February 2007

Angular momenta of fission fragments are sometimes exceeding 10 ℏ for thermal neutron induced and spontaneous fission. This is surprising since in the latter case the mother nucleus may have zero spin (e.g. 252Cf). In theory fragment spins are explained as a quantum mechanical effect. It is argued that they are due to zero-point oscillations of fragments being deformed at scission. In contrast to current theory it is shown that, for the specific case of near-magic 132Te, a large spin is generated by thermal excitation of single-particle states.
TOROIDAL STRUCTURE OF SUPER-HEAVY NUCLEI IN THE HFB THEORY
Authors: WARDA M.
Published: February 2007

Toroidal structure of super-heavy nuclei has been analyzed within the Hartree-Fock-Bogoliubov theory with the Gogny D1S force. The global minimum of the potential energy of systems with Z > 130 has been found for nuclei in the shape of a torus. The binding energy of toroidal super-heavy nuclei is lower than the energy of the spherical nuclei by 180 MeV.
TERNARY REACTIONS IN 197AU + 197AU COLLISIONS REVISITED
Authors: SKWIRA-CHALOT I. , SIWEK-WILCZYŃSKA K. , WILCZYŃSKI J. , AMORINI F. , ANZALONE A. , AUDITORE L. , BARAN V. , BRZYCHCZYK J. , CARDELLA G. , CAVALLARO S. , CHATTERJEE M. B. , COLONNA M. , DE FILIPPO E. , DI TORO M. , GAWLIKOWICZ W. , GRZESZCZUK A. , GUAZZONI P. , KOWALSKI S. , LA GUIDARA E. , LANZANÒ G. , LANZALONE G. , MAIOLINO C. , MAJKA Z. , NICOLIS N. G. , PAGANO A. , PAPA M. , PIASECKI E. , PIRRONE S. , PŁANETA R. , POLITI G. , PORTO F. , RIZZO F. , RUSSOTTO P. , SCHMIDT K. , SOCHOCKA A. , ŚWIDERSKI Ł. , TRIFIRÒ A. , TRIMARCHI M. , WIELECZKO J. P. , ZETTA L. , ZIPPER W.
Published: February 2007

Ternary events originating from the 197 Au + 197 Au reaction at 15 MeV/nucleon, studied by using the multidetector array CHIMERA at LNS Catania, have been collected in almost complete 2π range of the forward hemisphere of CHIMERA thus extending the angular range of our previously reported preliminary data. Energy- and time calibrations for heavy fragments at large angles were supplemented with an analysis of coincidence events of binary strongly damped reactions. Contrary to the previous preliminary results, the new complete data clearly show presence of sequential fission processes in which one of Au -like nuclei undergoes fission after re-separation of the primary binary system. Mechanism of these two types of reactions observed in our data, sequential fission reactions and prompt ternary processes, are presently studied using comparisons with predictions of the stochastic BNV model of Baran, Colonna and Di Toro and the QMD model of Łukasik.
ββ DECAY AND NUCLEAR STRUCTURE
Authors: CAURIER E. , NOWACKI F. , POVES A.
Published: February 2007

The determination of accurate nuclear matrix elements for ββ decay processes is a challenge for nuclear theory and can have a strong impact in neutrino physics.

Large Scale Shell Model (LSSM) calculations are among the best tools for such determination and recent developments have allowed to extend its application domains. In particular, systematic studies of nuclear matrix elements calculations have been now undertaken in this framework for most of the ββ emitters. These calculations are crucial in the determination of the most favorable emitters in the forthcoming generation of ββ experiments. The present paper focuses on the recent advances and remaining difficulties of shell model calculations for the neutrinoless mode. Stability and predictive power of the results will be discussed.
SUPPRESSION OF 0ν2β DECAY FROM CP VIOLATION
Authors: GÓŹDŹ MAREK , KAMIŃSKI WIESŁAW A.
Published: February 2007

The observed phenomenon of neutrino oscillations is interpreted as the proof that neutrinos must have mass. As this is true for the neutrinos in the mass basis, the mass matrix in the flavor (weak) basis may still contain zeros. This can happen if the CP violating phases, usually neglected, come into play and result in suppression of processes which half-life depends on the masses of νe, νμ, or ντ. In the present paper we investigate the possibility of such suppression of the neutrinoless double beta decay (0ν2β).
VIBRATIONAL STATE CONTRIBUTION TO NUCLEAR LEVEL DENSITY
Authors: PLUJKO V. A. , GORBACHENKO O. M. , KADENKO I. M.
Published: February 2007

The different simple methods for evaluation of vibrational enhancement factor of nuclear level density with allowance for collective state damping are considered and compared. A practical method for calculation of nuclear level density is recommended taking into account quadrupole and octupole vibrational states.
PROTON EMISSION, γ–LASERS AND TIME INTERFERENCE
Authors: DȨBICKI M. , GÓŹDŹ A. , STEFAŃSKA K.
Published: February 2007

The hypothetic very short, strong γ–laser pulses can lead to sub–threshold emission of protons. The energy spectra of emitted protons can give information on temporal structure of the process. One should observe the time interference phenomenon changing structure of the proton energy spectra. The description is done within the projection evolution approach to quantum mechanics.
STRUCTURE OF WOBBLING EXCITATIONS IN 163Lu
Authors: CARLSSON B. GILLIS
Published: February 2007

Using a many-particles plus rotor model, wobbling excitations built on top of a triaxial superdeformed band in 163 Lu are investigated. By extracting all parameters for the rotor from a mean field calculation a good correspondence with calculations based on the random-phase approximation is achieved.
SUGENO INTEGRAL AND GEOMETRIC INEQUALITIES
Authors: ROMAN-FLORES HERIBERTO , CHALCO-CANO YURILEV
Published: February 2007

In this work, we prove a Prékopa-Leindler type inequality for the Sugeno integral. More precisely, if 0 < λ < 1 and h((1-λ)x+λy) ≥ f(x)1-λg(y)λ, ∀ x,y ∈ ℝn, where h, f and g are nonnegative μ-measurable functions on ℝn, then [Formula: see text], for any concave fuzzy measure μ. Also, we derive a general Brunn-Minkowski inequality (standard form) for any homogeneous quasiconcave fuzzy measure μ on ℝn.
ON THE OBSERVABILITY OF CONTINUOUS-TIME DYNAMIC FUZZY CONTROL SYSTEMS
Authors: FENG YUHU , CHEN MIN , HU LIANGJIAN
Published: February 2007

This paper studies the observability of the initial value of continuous-time dynamic fuzzy control systems. The sufficient and necessary conditions for the initial value of fuzzy control system to be observable are given. A concept called strong observability is introduced and a sufficient condition for the initial value of system to be strongly observable is discussed. The fuzzy logic description of input-output relations using IF-THEN rule base is presented.
In-Situ Characterization of Si Surface Oxidation by High-Sensitivity Infrared Reflection Spectroscopic Method
Authors: Nishida Masahiro , Matsui Yuichi , Masanori Okuyama Masanori Okuyama , Yoshihiro Hamakawa Yoshihiro Hamakawa
Published: February 2007

Adsorption and oxidation on Si surface in a vacuum chamber for chemical vapor deposition (CVD) have been characterized in-situ by means of high-sensitivity infrared reflection spectroscopy. Oxidation time dependence of the Si-O absorption peak intensity shows step like increase and is attributed to layer-by-layer oxidation. The steplike increase in oxidation on a Si(111) surface etched by buffered HF (BHF) is clearer than that brought about by 5%HF; therefore, the surface etched by BHF is atomically flatter than that etched by 5%HF. Moreover, vacuum-ultra-violet (VUV) light irradiation from a D2 lamp promotes oxidation on the Si surface.
Critical Parameters for Obtaining Low Particle Densities on a Si Surface in an HF-Last Process
Authors: Alay Josep-Lluís , Verhaverbeke Steven , Vandervorst Wilfried , Heyns Marc
Published: February 2007

A study was made on the relation between particle densities and the (remaining) degree of oxidation of a cleaned (100) Si surface following different HF-treatments (HF, HF/IPA, DI-rinse). A detailed comparison between (X-ray photoelectron spectroscopy) XPS and contact angle measurements of a water droplet with the Si surface shows that the latter method is sensitive to less than 1/10 of a SiO2 monolayer on the (100)Si surface. The results obtained with XPS point out that minute amounts of suboxides (a few percentage of a monolayer) are the dominant cause for particles. On the other hand, HF-dipping time and HF bath temperature are found to be the determinant parameters in an HF-last process. In addition the quality of the rinsing water as well as the initial roughness (Si vs polysilicon) play a major role.
Effect of Gate Materials on Generation of Interface State by Hot-Carrier Injection
Authors: Hideaki Matsuhashi Hideaki Matsuhashi , Satoshi Nishikawa Satoshi Nishikawa
Published: February 2007

The effect of gate materials on hot-carrier degradation, especially on the generation of the interface state, is investigated. The generation of the interface state in n-channel metal-oxide-semiconductor field-effect transistors (NMOSFET's) by drain avalanche hot-carrier (DAHC) injection is independent of the gate material. On the other hand, the generation of the interface state in p-channel MOSFET's (PMOSFET's) by DAHC injection is greatly dependent on the gate material but almost independent of the channel doping profile, in other words, a surface- or buried-channel device. The increase in interface state density (ΔD
it) in tungsten (W)-gate PMOSFET's is much larger than that of polycide-gate devices. In order to verify the effect of carrier species injected into SiO2, electrons were injected from the substrate into the gate electrode by two methods: Fowler-Nordheim injection and hot-electron injection from the forward biased p-n junction injector. The large ΔD
it in W-gate devices is observed in both methods. It is confirmed that the large ΔD
it in W-gate PMOSFET's stressed by DAHC injection is caused by the injection of electrons into SiO2. These phenomena are considered to occur due to the difference of hole injection from the gate into SiO2, excited at the gate by electron injection, between gate materials.
Polycrystalline Carbon: A Novel Material for Gate Electrodes in MOS Technology
Authors: Raghavan G. , J. L. Hoyt J. L. Hoyt , J. F. Gibbons J. F. Gibbons
Published: February 2007

Polycrystalline carbon is proposed as a potential candidate for the gate material for submicron VLSI devices. Fine grained polycarbon films with significantly lower resistivity than polysilicon have been deposited on silicon dioxide. Well behaved capacitance-voltage and oxide breakdown characteristics are observed. Tunneling current measurements on these films indicate lower depletion effects in polycarbon compared to polysilicon. PMOSFETs have been fabricated with carbon gates in a conventional silicon process line to demonstrate the compatibility of polycrystalline carbon with existing silicon processes.
Electronic Structures of Si-Based Manmade Crystals
Authors: Sugahara Satoshi , Osamu Sugiura Osamu Sugiura , Masakiyo Matsumura Masakiyo Matsumura
Published: February 2007

Electronic structures have been calculated for Si-based manmade crystals with homogeneous strain using a tight-binding sp3s* model. Interesting properties, such as direct transition and pseudonarrow bandgap, appear especially in crystals where two monolayers of non-Si atoms are stacked in many layers of Si atoms along the (111) orientation.
Low Resistance and Thermally Stable Ti-Silicided Shallow Junction Formed by Advanced 2-Step Rapid Thermal Processing and Its Application to Deep Submicron Contact
Authors: Kotaki Hiroshi , Mitsuhashi Katsunori , Takagi Junkou , Akagi Yoshiro , Koba Masayoshi
Published: February 2007

A low-resistivity thermally stable TiSi2 shallow junction applicable to a deep submicron contact has been developed. This was achieved through the use of an advanced 2-step rapid thermal silicidation called the “AAS” process and the use of an Al-based metal/TiN/Ti/TiSi2 contact technique. The low sheet resistance and high thermal stability of TiSi2 film on n+-Si reached the same levels as those on undoped Si, though the silicidation on n+-Si is more difficult than that on p+ or undoped Si. The film and contact resistivities were about 11.5 µΩ cm and 1∼2×10-8 Ω cm2, respectively. Ring oscillators utilizing these processes exhibited a 15% improvement in speed as compared with conventional cases [without self-aligned silicide (SALICIDE)].
Control of GaAs Schottky Barrier Height by Ultrathin Molecular beam epitaxy si interface control layer
Authors: koyanagi ken-ichi , Kasai Seiya , Hasegawa Hideki
Published: February 2007

An attempt is made to control the Schottky barrier height (SBH) of Al/GaAs(100) Schottky barrier diodes by inserting an ultrathin Molecular beam epitaxy (MBE) Si interface control layer (Si ICL). A theory for SBH control including an ideal case and a relaxed case is presented based on the disorder-induced gap state (DIGS) model. The Schottky barrier height (SBH) is measured by the X-ray photoelectron spectroscopy (XPS), current-voltage (I-V) and capacitance-voltage (C-V) techniques. Theory and experiment show that the SBH can be varied precisely over a wide range of about 400 meV by the use of pseudomorphic Si ICL with suitable As doping. When the Si ICL is above the critical thickness of 10 Å, SBH control becomes more difficult due to competition between the ionized dopant atoms and the ionized interface states at the Si ICL-GaAs interface.
Nonvolatile Memory Based on Phase Transition in Chalcogenide Thin Film
Authors: Nakayama Kazuya , Kitagawa Toshiya , Masashi Ohmura Masashi Ohmura , Masakuni Suzuki Masakuni Suzuki
Published: February 2007

Electrically erasable nonvolatile memories based on the reversible amorphous-crystalline phase transition were studied. In the appropriate set- and reset-conditions, more than 105 repetition cycles of write/erase were attained in the memory devices composed of As-Sb-Te films. Deterioration of memory devices was caused by the phase separation due to the segregation of crystallites in the active region in the memory cells and in the peripheral area around the active region. The phase separation in the peripheral area around the active region still occurred even in the memory devices using well-designed materials. Deterioration phenomena can be greatly suppressed by the reduction of the device geometry.
Wavelength Selective Metal-Semiconductor-Metal Photodetector with Integrated Fabry-Perot Resonator for High Bandwidth Receivers
Authors: Ulrich Prank Ulrich Prank , Wolfgang Kowalsky Wolfgang Kowalsky
Published: February 2007

Surface operating metal-semiconductor-metal photodetectors with monolithically integrated asymmetrical Fabry-Perot resonator are presented. Because of the low capacitance of the planar electrode configuration frequency limits exceeding 35 GHz easily can be obtained. Wavelength demultiplexing of closely spaced channels is achieved by an integrated Fabry-Perot resonator. An optical bandwidth of 1.0 nm and a contrast ratio exceeding 10:1 are demonstrated.
Pixels Consisting of Double Vertical-Cavity Detector and Single Vertical-Cavity Laser Sections for 2-D Bidirectional Optical Interconnections
Authors: Kosaka Hideo , Ogura Ichiro , Sugimoto Mitsunori , Saito Hideaki , Takahiro Numai Takahiro Numai , Kenichi Kasahara Kenichi Kasahara
Published: February 2007

We have proposed a structure for optical pixels consisting of a double vertical-cavity detector and single vertical-cavity laser section. This pixel can be formed by simple fabrication processes because the structures of the detector and laser section are almost the same, and the characteristics of the laser and detector sections can be independently optimized by choosing the pair number of each distributed Bragg reflector. We have achieved a spectral bandwidth and peak absorptivity of the double vertical-cavity detector section about five times those of the single vertical-cavity laser section.
Threading Dislocation Reduction in InP on GaAs by Thin Strained Interlayer and its Application to the Fabrication of 1.3-µm-Wavelength Laser on GaAs
Authors: Okuno Yae , Kawano Toshihiro , Tomonobu Tsuchiya Tomonobu Tsuchiya , Tsuyoshi Taniwatari Tsuyoshi Taniwatari
Published: February 2007

This paper examines the reduction of threading dislocation by a thin strained interlayer (SIL), and a long-wavelength laser fabricated on a GaAs substrate with SILs. A cross-sectional transmission electron microscope is used to observe the dislocation blocking ability of an SIL made of InGaP, which is inserted in an InP layer grown on a GaAs substrate. The characteristics of the BH laser emitting at 1.3 µm on GaAs are investigated. Most of them are improved by SIL insertion. In particular, threshold current is reduced to 70% on average and is also distributed more uniformly.
CdZnSe-ZnSe Multilayers by Metalorganic Vapour Phase Epitaxy Using Dimethylselenide
Authors: Parbrook Peter J. , Atsushi Kamata Atsushi Kamata , Tsutomu Uemoto Tsutomu Uemoto
Published: February 2007

The growth of CdZnSe-ZnSe multilayers using (CH3)2Se at 475°C is reported. Despite the occurrence of thermally induced diffusion, observed by secondary ion mass spectrometry, quantum wells of the desired alloy composition have been successfully grown for a well width of 20 nm. The uniform layers which can be obtained using dimethylselenide as the group VI precursor allow stimulated emission to be observed at 77 K from a multiple quantum well structure consisting of three, 30 nm wells under nitrogen laser excitation.
What is the ultimate goal in acid-base regulation?
Authors: Balakrishnan Selvakumar , Gopalakrishnan Maya , Alagesan Murali , Prakash E. Sankaranarayanan
Published: February 2007

It is common to see chapters on acid-base physiology state that the goal of acid-base regulatory mechanisms is to maintain the pH of arterial plasma and not arterial Pco2 (PaCO2) or plasma HCO3. A hypothetical situation in which the PaCO2 of arterial plasma is 80 mmHg and the plasma HCO3 concentration is 48 mM is presented and analyzed to get over this misconception. As per the modified Henderson equation, the pH of arterial plasma would be 7.4; however, we explain that this may be associated with intracellular acidosis due to intracellular hypercapnia and that derangement of homeostasis is evident from the occurrence of respiratory depression and, eventually, coma in the patient described. This suggests that the ultimate goal of acid-base regulatory mechanisms is not just the maintenance of the pH of arterial plasma but the maintenance of the steady-state pH of intracellular fluid as well.
Design guidelines for the development of digital nutrigenomics learning material for heterogeneous target groups
Authors: Busstra Maria C. , Hartog Rob , Kersten Sander , Müller Michael
Published: February 2007

Nutritional genomics, or nutrigenomics, can be considered as the combination of molecular nutrition and genomics. Students who attend courses in nutrigenomics differ with respect to their prior knowledge. This study describes digital nutrigenomics learning material suitable for students from various backgrounds and provides design guidelines for the development of the learning material. These design guidelines, derived from theories on cognitive science and instructional design, describe the selection of interaction types for learning tasks and the timing of information presentation. The learning material supports two learning goals: 1) the formulation of meaningful research questions in the field of nutrigenomics and 2) the development of feasible experiments to answer these questions. The learning material consists of two cases built around important nutrigenomics topics: 1) personalized diets and 2) the role of free fatty acids in the regulation of hepatic gene transcription. Each case consists of several activities to promote active learning by the student. Evaluation of the cases in a realistic academic educational setting indicates that the cases were useful.
Transcription factor CHF1/Hey2 regulates the global transcriptional response to platelet-derived growth factor in vascular smooth muscle cells
Authors: Shirvani Shervin M. , Mookanamparambil Linette , Ramoni Marco F. , Chin Michael T.
Published: February 2007

The cardiovascular restricted transcription factor CHF1/Hey2 has been previously shown to regulate the smooth muscle response to growth factors. To determine how CHF1/Hey2 affects the smooth muscle response to growth factors, we performed a genomic screen for transcripts that are differentially expressed in wild-type and knockout smooth muscle cells after stimulation with platelet-derived growth factor. We screened 45,101 probes representing >39,000 transcripts derived from at least 34,000 genes, at eight different time points. We analyzed the expression data utilizing an algorithm based on Bayesian statistics to derive the best polynomial clustering model to fit the expression data. We found that in a total of 9,827 transcripts the normalized ratio of knockout to wild-type expression diverged more than threefold from baseline in at least one time point, and these transcripts separated into 17 distinct clusters. Further analysis of each cluster revealed distinct alterations in gene expression patterns for immediate early genes, transcription factors, matrix metalloproteinases, signaling molecules, and other molecules important in vascular biology. Our findings demonstrate that CHF1/Hey2 profoundly affects vascular smooth muscle phenotype by altering both the absolute expression level of a variety of genes and the kinetics of growth factor-induced gene expression.
The Identification of (ETV6)/RUNX1-Regulated Genes in Lymphopoiesis Using Histone Deacetylase Inhibitors in ETV6/RUNX1-Positive Lymphoid Leukemic Cells
Authors: Starkova Julia , Madzo Jozef , Cario Gunnar , Kalina Tomas , Ford Anthony , Zaliova Marketa , Hrusak Ondrej , Trka Jan
Published: February 2007

Purpose: Chimeric transcription factor ETV6/RUNX1 (TEL/AML1) is believed to cause pathologic block in lymphoid cell development via interaction with corepressor complex and histone deacetylase. We wanted to show the regulatory effect of ETV6/RUNX1 and its reversibility by histone deacetylase inhibitors (HDACi), as well as to identify potential ETV6/RUNX1-regulated genes.

Experimental Design: We used luciferase assay to show the interaction of ETV6/RUNX1 protein, ETV6/RUNX1-regulated gene, and HDACi. To identify ETV6/RUNX1-regulated genes, we used expression profiling and HDACi in lymphoid cells. Next, using the flow cytometry and quantitative reverse transcription-PCR, we measured differentiation changes in gene and protein expression after HDACi treatment.

Results: Luciferase assay showed repression of granzyme B expression by ETV6/RUNX1 protein and the reversibility of this effect by HDACi. Proving this regulatory role of ETV6/RUNX1, we identified, using complex statistical analysis, 25 genes that are potentially regulated by ETV6/RUNX1 protein. In four selected genes with known role in the cell cycle regulation (JunD, ACK1, PDGFRB, and TCF4), we confirmed expression changes after HDACi by quantitative analysis. After HDACi treatment, ETV6/RUNX1-positive cells showed immunophenotype changes resembling differentiation process compared with other leukemic cells (BCR/ABL, ETV6/PDGFRB positive). Moreover, ETV6/RUNX1-positive leukemic cells accumulated in G1-G0 phase after HDACi whereas other B-lineage leukemic cell lines showed rather unspecific changes including induction of apoptosis and decreased proliferation.

Conclusions: Presented data support the hypothesis that HDACi affect ETV6/RUNX1-positive cells via direct interaction with ETV6/RUNX1 protein and that treatment with HDACi may release aberrant transcription activity caused by ETV6/RUNX1 chimeric transcription factor.
Genome-Wide Scan for Blood Pressure in Australian and Dutch Subjects Suggests Linkage at 5P, 14Q, and 17P
Authors: Hottenga Jouke-Jan , Whitfield John B. , Posthuma Danielle , Willemsen Gonneke , de Geus Eco J.C. , Martin Nicholas G. , Boomsma Dorret I.
Published: February 2007

Large-scale studies estimate the heritability of blood pressure at ≈50%. We carried out a genome-wide linkage analysis to search for chromosomal loci that might explain this heritability using longitudinal, multiple measures of systolic and diastolic blood pressure obtained in sibling pairs and dizygotic twin pairs from 2 countries (a total of 286 pairs from Australia and 636 pairs from the Netherlands). These pairs and a large number of their parents were genotyped with microsatellite markers. Multivariate linkage analysis of the combined data of both countries, using a variance components approach, showed suggestive linkage for diastolic blood pressure on chromosomes 5p13.1 (logarithm of odds score: 2.48), 14q12 (logarithm of odds score: 2.40) and 17q24.3 (logarithm of odds score: 2.36). The highest logarithm of odds score of 1.21 for systolic blood pressure was observed on chromosome 13q34. These results replicate earlier findings and add to a slowly emerging picture of multiple loci contributing to quantitative blood pressure variation.
Prevalence of Desmin Mutations in Dilated Cardiomyopathy
Authors: Taylor Matthew R.G. , Slavov Dobromir , Ku Lisa , Di Lenarda Andrea , Sinagra Gianfranco , Carniel Elisa , Haubold Kurt , Boucek Mark M. , Ferguson Debra , Graw Sharon L. , Zhu Xiao , Cavanaugh Jean , Sucharov Carmen C. , Long Carlin S. , Bristow Michael R. , Lavori Philip , Mestroni Luisa
Published: February 2007

Background—

Desmin-related myofibrillar myopathy (DRM) is a cardiac and skeletal muscle disease caused by mutations in the desmin (
DES
) gene. Mutations in the central 2B domain of
DES
cause skeletal muscle disease that typically precedes cardiac involvement. However, the prevalence of
DES
mutations in dilated cardiomyopathy (DCM) without skeletal muscle disease is not known.

Methods and Results—

Denaturing high-performance liquid chromatography was used to screen
DES
for mutations in 116 DCM families from the Familial Dilated Cardiomyopathy Registry and in 309 subjects with DCM from the Beta-Blocker Evaluation of Survival Trial (BEST).
DES
mutations were transfected into SW13 and human smooth muscle cells and neonatal rat cardiac myocytes, and the effects on cytoskeletal desmin network architecture were analyzed with confocal microscopy. Five novel missense
DES
mutations, including the first localized to the highly conserved 1A domain, were detected in 6 subjects (1.4%). Transfection of
DES
mutations in the 2B domain severely disrupted the fine intracytoplasmic staining of desmin, causing clumping of the desmin protein. A tail domain mutation (Val459Ile) showed milder effects on desmin cytoplasmic network formation and appears to be a low-penetrant mutation restricted to black subjects.

Conclusions—

The prevalence of
DES
mutations in DCM is between 1% and 2%, and mutations in the 1A helical domain, as well as the 2B rod domain, are capable of causing a DCM phenotype. The lack of severe disruption of cytoskeletal desmin network formation seen with mutations in the 1A and tail domains suggests that dysfunction of seemingly intact desmin networks is sufficient to cause DCM.
Identification of a Novel Polymorphism in the 3′UTR of the
l
-Arginine Transporter Gene
SLC7A1
Authors: Yang Zhiyong , Venardos Kylie , Jones Emma , Morris Brian J. , Chin-Dusting Jaye , Kaye David M.
Published: February 2007

Background—

Endothelial dysfunction because of reduced nitric oxide bioavailability is a key feature of essential hypertension. We have found that normotensive siblings of subjects with essential hypertension have impaired endothelial function accompanied by altered arginine metabolism.

Methods and Results—

We have identified a novel C/T polymorphism in the 3′UTR of the principal arginine transporter, solute carrier family 7 (cationic amino acid transporter, y+ system), member 1 gene (
SLC7A1
). The minor
T
allele significantly attenuates reporter gene expression (
P
<0.01) and is impaired in its capacity to form DNA-protein complexes (
P
<0.05). In 278 hypertensive subjects the frequency of the
T
allele was 13.3% compared with 7.6% in 498 normotensive subjects (
P
<0.001). Moreover, the overall genotype distribution observed in hypertensives differed significantly from that in normotensives (
P
<0.001). To complement these studies, we generated an endothelial-specific transgenic mouse overexpressing
l
-arginine transporter
SLC7A1
. The
Slc7A1
transgenic mice exhibited significantly enhanced responses to the endothelium-dependent vasodilator acetylcholine (−log EC
50
for wild-type versus
Slc7A1
transgenic: 6.87±0.10 versus 7.56±0.13;
P
<0.001). This was accompanied by elevated production of nitric oxide by isolated aortic endothelial cells.

Conclusions—

The present study identifies a key, functionally active polymorphism in the 3′UTR of
SLC7A1
. As such, this polymorphism may account for the apparent link between altered endothelial function,
l
-arginine, and nitric oxide metabolism and predisposition to essential hypertension.
An Introduction to “Early College”
Authors: Brewer Dominic J. , Stern Stefanie , Ahn June
Published: February 2007

Several national and international assessments have demonstrated that there has been little improvement in the performance of American high school students in recent decades. High school students are increasingly underprepared for transition into college-level course-work. One new approach to high school redesign, “early college,” seeks to address these issues. The model features a rigorous academic course of study that engages students in college-level work in grades nine through fourteen. Early college is a subset of dual enrollment programs providing opportunities for students to complete high school and college credits with the same courses. The goal is to prepare students academically for college-level coursework while easing the transition to higher education. Early college offers promise in directly addressing student academic performance, attrition rates, and readiness for college, but further research is needed to determine its efficacy and scalability.
A Novel Method for Quantifying Value in Spaceborne Soil Moisture Retrievals
Authors: Crow Wade T.
Published: February 2007

A novel methodology is introduced for quantifying the added value of remotely sensed soil moisture products for global land surface modeling applications. The approach is based on the assimilation of soil moisture retrievals into a simple surface water balance model driven by satellite-based precipitation products. Filter increments (i.e., discrete additions or subtractions of water suggested by the filter) are then compared to antecedent precipitation errors determined using higher-quality rain gauge observations. A synthetic twin experiment demonstrates that the correlation coefficient between antecedent precipitation errors and filter increments provides an effective proxy for the accuracy of the soil moisture retrievals themselves. Given the inherent difficulty of directly validating remotely sensed soil moisture products using ground-based observations, this assimilation-based proxy provides a valuable tool for efforts to improve soil moisture retrieval strategies and quantify the novel information content of remotely sensed soil moisture retrievals for land surface modeling applications. Using real spaceborne data, the approach is demonstrated for four different remotely sensed soil moisture datasets along two separate transects in the southern United States. Results suggest that the relative superiority of various retrieval strategies varies geographically.
Numerical Studies of Wet versus Dry Soil Regimes in the West African Sahel
Authors: Alonge Charles J. , Mohr Karen I. , Tao Wei-Kuo
Published: February 2007

The West African Sahel lies between the wet, humid equatorial zone of Africa to the south and the Sahara Desert to the north. This topography results in a strong north–south precipitation gradient. A coupled land–atmosphere (cloud resolving) model and observed data from the Hydrological Atmospheric Pilot Experiment in the Sahel were used to simulate both wet and dry soil moisture regimes. There are two case studies—one characterized by convective precipitation, the other by fair weather. In both of the case studies, evapotranspiration from the tiger bush land cover was noticeably larger in the wet soil moisture regime. The increase in latent heat flux was the key factor in creating a boundary layer that was more favorable to late-afternoon deep convection in the wet regime. Differences in boundary layer growth and development between the case studies suggested a more important role for the land surface in fair weather environments versus convective precipitation environments.
The Intersection of Age and Gender
Authors: Krekula Clary
Published: February 2007

This article discusses the position of older women in gender theory and in social gerontology. It shows how older women are made invisible in gender theory through the selection of arenas and themes, by model monopoly and by a lack of problematization of age. In the social gerontological field, older women have frequently been objects of research. However, double jeopardy assumptions have resulted in a perspective that foregrounds misery. Results from focus group interviews with women aged 75 and over, shed light on ageing as a process of development and on twofold bodily meanings, such as on-stage-body and off-stage-body. Thus, based on an approach of age and gender as intertwining systems, the article argues for a more complex understanding of the intersection of age and gender.
Gender and the Devolution of Pension Risks in the US
Authors: O’Rand Angela M. , Shuey Kim M.
Published: February 2007

This article uses data from multiple waves of the Panel Study of Income Dynamics to examine inequality in the accumulation of pension balances in private accounts for two cohorts of workers in the US. The new occupational pension environment is characterized by the rise of defined contribution plans and the devolution of risk and responsibility for retirement saving. While men and women in this environment face new pension risks, women continue to bear greater risks associated with lower workplace earnings and family position. Unmarried women consistently have the greatest risk of low pension balances in defined contribution plans (DC) and individual retirement accounts (IRAs). Divorce, unstable employment histories and lower levels of education and income decrease pension savings. The authors conclude that although recent changes have increased women’s access to occupational pensions, these changes have preserved, and perhaps increased, familiar disadvantages associated with gender, marital status and labor market position.
‘The Eye is the Lamp of the Body’: Its Meaning in the Sermon on the Mount
Authors: Whitters Mark F.
Published: February 2007

How does the eye serve as ‘the lamp of the body’ in the Sermon on the Mount? A comparison with other ‘eye’ biblical texts and the immediate context of the passage do not provide an unequivocal answer. This article finds clues for its meaning in the literary world of sapiential literature of the Bible and in the Sermon on the Mount. The interpretation derived from such an approach finds support in a comparison of this passage to its parallel in the Gospel of Thomas.
Evolution of Player Skill in the America's Army Game
Authors: Moon Il-Chul , Schneider Mike , Carley Kathleen M.
Published: February 2007

Many disciplines utilize computer games as interactive training simulations.However, their use is often limited to training mechanical skills, and they are not viewed as a sophisticated training tool with which to teach human interactions within organizations and social/organizational skills. Therefore, in this paper we examine how the players of the game America's Army changed their performance, play styles and social positions after one year of game play experience. For the initial investigation, we compare performance measures and play style at the beginning and the end of our survey period.Also, we calculate social network measures, such as centrality measures and clustering measures, to see how the social positions of the players change.After the comparison, we observe that players with one year of experience are more sensitive to communication and have tighter and denser communication networks around them.
Simulation Technologies for Health Sciences Curriculum
Authors: Kurkovsky Anatoly
Published: February 2007

In this paper we discuss the main elements of an approach to teach simulation discipline in a small university with an interdisciplinary specialization in pharmaceutics, biology, health sciences, and computer science which are combined into a health sciences curriculum. We analyze existing ways to teach simulation courses and identify the specificity and goals within our approach. We propose the content of a simulation course sequence for the mentioned type of university. It includes three units: general simulation methodology, case studies, and building of real simulation models. The proposed new approach reinforces the problem-solving skills of students and their opportunities to conduct applied research. We implemented the proposed approach in a simulation course sequence and we successfully conducted student research projects.
Teaching Negotiation Skills through Practice and Reflection with Virtual Humans
Authors: Core Mark , Traum David , Lane H. Chad , Swartout William , Gratch Jonathan , van Lent Michael , Marsella Stacy
Published: February 2007

Although the representation of physical environments and behaviors will continue to play an important role in simulation-based training, an emerging challenge is the representation of virtual humans with rich mental models (e.g., including emotions, trust) that interact through conversational as well as physical behaviors. The motivation for such simulations is training soft skills such as leadership, cultural awareness, and negotiation, where the majority of actions are conversational, and the problem solving involves consideration of the emotions, attitudes, and desires of others.The educational power of such simulations can be enhanced by the integration of an intelligent tutoring system to support learners' understanding of the effect of their actions on virtual humans and how they might improve their performance. In this paper, we discuss our efforts to build such virtual humans, along with an accompanying intelligent tutor, for the domain of negotiation and cultural awareness.