bluuebunny/crossref_metadata_2025 huggingface dataset:
From Chimpanzees to the Human Mind
Authors: Matsuzawa Tetsuro
Published: June 2003

Original Intelligence
Unlocking the Mystery of Who We Are. David Premack and Ann Premack. McGraw-Hill, New York, 2003. 287 pp. $24.95, £18.99, C$34.95. ISBN 0-07-138142-2.

The authors present a theory of mind developed through their critical appraisal of findings from cognitive and comparative psychology and primatology, and they discuss its implications for understanding animal intelligence and educating children.
SCALABLE AND OPTIMAL SPEED-UP PARALLEL ALGORITHMS FOR TEMPLATE MATCHING ON ARRAYS WITH RECONFIGURABLE OPTICAL BUSES
Authors: WU CHIN-HSIUNG , HORNG SHI-JINN
Published: June 2003

The computational model on which the algorithms are developed is the array with reconfigurable optical buses (AROB). It integrates the advantages of both optical transmission and electronic computation. The main contributions of this paper are in designing several optimal and/or optimal speed-up template matching algorithms with varying degrees of parallelism on the AROB model. For an N × N digitized image and an M × M template, when the domains of the image and the template are O( log N)-bit integers, we first design several basic operations for window broadcasting and rotation. Then based on these basic operations, three efficient and scalable algorithms for template matching are derived using various numbers of processors on a two-dimensional (2-D) or 3-D AROB. For 1 ≤ r ≤ N, 1 ≤ p ≤ M ≤ q ≤ N, one runs in [Formula: see text] time using r × r processors, another runs in [Formula: see text], (resp. [Formula: see text]) time using pN × pN/ log M (resp. pN × pN × log N) processors, and the other runs in [Formula: see text] (resp. [Formula: see text]) time using pq × pq/ log M (or pq × pqN × log N) processors, respectively. The latter two algorithms can be tuned to run in O(1) time on a 2-D AROB. To the best of our knowledge, there are no algorithms which can reach this time complexity for this problem on a 2-D array architecture.
BINDING ENERGIES OF HYDROGEN-LIKE IMPURITIES IN A SEMICONDUCTOR IN INTENSE TERAHERTZ LASER FIELDS
Authors: NIE J. L. , XU W. , LIN L. B.
Published: June 2003

We present a detailed theoretical study of the influence of linearly polarized intense terahertz (THz) laser radiation on energy states of hydrogen-like impurities in semiconductors. The dependence of the binding energy for ground (1s) and first excited (2s) states, E1s and E2s, on the intensity and the frequency of the THz radiation has been examined for a GaAs-based system. It is found that E1s, E2s and E2s-E1s decrease with increasing radiation intensity or with decreasing radiation frequency, which implies that an intense THz field can enhance ionization of dopants in semiconductors. Our analytical and numerical results show that one of the most important results obtained by A. L. A. Fonseca et al. [Phys. Stat. Sol. (b)186, K57 (1994)] is incorrect.
ON THE SIGNIFICANCE OF THE TENT MAP
Authors: GÓRA PAWEŁ , BOYARSKY ABRAHAM
Published: June 2003

Discrete time dynamical systems generated by the iteration of nonlinear maps provide simple and interesting examples of chaotic systems. But what is the physical principle behind the emergence of these maps? In this note we present an approach to this problem by considering a class, Y, of 2–1 chaotic maps on [0, 1] that are symmetric and have symmetric invariant densities. We prove that such maps are conjugate to the tent map. In Y we search for maps that minimizes a functional that depends on y ∈ Y and fy, the probability density function invariant under y. We define a simple functional whose extremal value is achieved by the tent map.
NEWTONIAN LIMIT OF STRING-DILATON GRAVITY
Authors: CAPOZZIELLO S. , LAMBIASE G.
Published: June 2003

We study the weak-field limit of string-dilaton gravity and derive corrections to the Newtonian potential having strength directly depends on the self interaction potential and the nonminimal coupling of the dilaton scalar field. We discuss also possible astrophysical applications of the results, in particular the flat rotation curves of spiral galaxies.
THE IMPRESSIVE COMPLEXITY IN THENAUTILUS POMPILIUSSHELL
Authors: CASTREJÓN PITA A. A. , CASTREJÓN PITA J. R. , SARMIENTO GALÁN A. , CASTREJÓN GARCÍA R.
Published: June 2003

The complexity of the Nautilus pompilius shell is analyzed in terms of its fractal dimension and its equiangular spiral form. Our findings assert that the shell is fractal from its birth and that its growth is dictated by a self-similar criterion (we obtain the fractal dimension of the shell as a function of time). The variables that have been used for the analysis show an exponential dependence on the number of chambers/age of the cephalopod, a property inherited from its form.
FRACTAL IMAGES OF GENERALIZED MANDELBROT SETS
Authors: SHIAH AICHYUN , ONG KIM-KHOON , MUSIELAK ZDZISLAW E.
Published: June 2003

The transformation function z ← zα+βi+c, with both α and β being either positive or negative integers or real numbers, is used to generate families of mostly new fractal images in the complex plane [Formula: see text]. The calculations are restricted to the principal value of zα+βi and the obtained fractal images are called the generalized Mandelbrot sets, ℳ (α, β). Three general classes of ℳ (α, β) are considered: (1) α ≠ 0 and β = 0; (2) α ≠ 0 and β ≠ 0; and (3) α = 0 and β ≠ 0. Our results demonstrate that the shapes of fractal images representing ℳ (α, 0) are usually significantly deformed when β ≠ 0, and that the size of either stable (α > 0) or unstable (α < 0) regions in the complex plane may increase as a result of non-zero β. It is also shown that fractal images of the generalized Mandelbrot sets ℳ (0, β) are significantly different than those obtained with a non-zero α.
A Review of the History of Traumatic Stress Studies in Japan
Authors: Goto Toyomi , Wilson John P.
Published: June 2003

Based on available literature, this review article investigates traumatic stress studies in Japan from the late 19th century to the present for English speaking audiences. First, traumatic neuroses of war victims, A-bomb survivors, and victims of work-related accidents are discussed. Second, traumatic stress studies of victims of other manmade disasters, such as the sarin gas attacks in Tokyo, domestic violence, and burn injuries. Third, psychological outcomes of natural disaster studies are discussed in relation to social support and help-seeking tendencies of Japan disaster victims.
Noninvasive mechanical ventilation improves the immediate and long-term outcome of COPD patients with acute respiratory failure
Authors: Confalonieri M , Parigi P , Scartabellati A , Aiolfi S , Scorsetti S , Nava S , Gandola L
Published: June 2003

Noninvasive positive pressure ventilation (NPPV) has been proposed in COPD patients with acute on chronic respiratory failure (ACRF) in order to avoid endotracheal intubation and to improve immediate outcome, but long-term outcome of this therapeutic approach is still undefined. We evaluated short- and long-term (1 year) outcome of early administration of NPPV in 24 patients with ACRF due to exacerbated COPD (Group A) in comparison with 24 matched historical-control patients treated conventionally (Group B). Patients of Group A were initially treated with NPPV via nasal mask in the presence of pH < or = 7.32, and/or Pa,O2 < 7.98 kPa, and/or Pa,CO2 > 7.18 kPa, plus signs of respiratory distress. In-hospital survival rate was not significantly different in Group A vs Group B, but the patients treated with NPPV showed an earlier improvement in blood gases and a better pH and respiratory rate at discharge. Only 2 patients of Group A needed endotracheal intubation as compared with 9 of Group B. Hospital stay was significantly reduced in survivors of Group A vs Group B. Further severe relapses of ACRF in Group A were treated using NPPV. The number and length of further hospitalizations for pulmonary exacerbations were significantly higher in Group B compared with Group A. The survival rate at 12 months was significantly lower in Group B than in Group A (50% vs 71%). In conclusion, NPPV administration in patients with ACRF due to exacerbated COPD improves not only immediate but also long-term outcome.
Effect of salmeterol compared with beclomethasone on allergen-induced asthmatic and inflammatory responses
Authors: Pizzichini MM , Kidney JC , Wong BJ , Morris MM , Efthimiadis A , Dolovich J , Hargreave FE
Published: June 2003

Salmeterol is a selective long-acting beta 2-agonist bronchodilator considered to have added anti-inflammatory effects, but this is controversial. We investigated the effects of a single dose of salmeterol, 100 micrograms, on the physiological and inflammatory responses to inhaled allergen and compared these with the effects of a single dose of beclomethasone, 500 micrograms, and of placebo. Eight atopic adults with mild stable asthma, treated only with inhaled short-acting beta 2-agonist when needed, attended the laboratory sequentially for screening tests, two single-blind control inhalation tests preceded 30 min by placebo or salmeterol and three allergen inhalation tests preceded by placebo, salmeterol or beclomethasone double-blind in random order. Airway responsiveness to methacholine (assessed as the provocative concentration of methacholine producing 20% fall in forced expiratory volume in one second (PC20)), induced sputum eosinophils, blood eosinophils and serum eosinophil cationic protein (ECP) were examined before and 7-48 h after treatment. The statistical power to detect twofold changes in blood and sputum parameters was > or = 90%. Salmeterol inhaled before allergen challenge completely prevented the early asthmatic response, late asthmatic response and fall in methacholine PC20 at 24 h, and produced additional bronchodilatation. These effects were similar to those obtained by the inhalation of a single dose of salmeterol before the control inhalation test, and significantly better than those observed after a single dose of beclomethasone inhaled before the allergen test. Beclomethasone had no effect on the early asthmatic response or on the fall in methacholine PC20 at 24 h but partially inhibited the late asthmatic response. Neither salmeterol nor beclomethasone had any significant effect on sputum or blood inflammatory changes 7-48 h after allergen inhalation. In conclusion, whilst salmeterol had no demonstrable anti-inflammatory action in sputum after allergen challenge in asthma, neither did a single dose of the positive anti-inflammatory control, beclomethasone. The latter result excludes a more positive judgement on the possible anti-inflammatory action of salmeterol. However, the results do indicate that potent functional effects of a single dose of salmeterol can mask the airway inflammatory cell influx caused by inhaled allergen.
Nucleotide-induced mucin release from primary hamster tracheal surface epithelial cells involves the P2u purinoceptor
Authors: Kim KC , Park HR , Shin CY , Akiyama T , Ko KH
Published: June 2003

Mucin release by airway surface epithelial cells is regulated by extracellular adenosine triphosphate (ATP) via a P2 purinoceptor-mediated mechanism. The objective of the present experiment was to examine the possible involvement of uridine triphosphate (UTP) in this purinergic signal transduction pathway. Using primary hamster tracheal surface epithelial cells, ATP and UTP were compared in their abilities: 1) to displace ATP gamma S35-binding to intact cells; 2) to accumulate inositol phosphates; and 3) to stimulate mucin release. Finally, the presence of a P2u receptor message was examined. Our results showed that: 1) UTP was much less effective than ATP in displacing ATP gamma S35-binding (median inhibitory concentrations (IC50S) 240 vs 2.9 microM); 2) UTP was more potent than ATP in accumulating inositol phosphates (100 vs 43% increase at 2mM); 3) UTP was equipotent with ATP in stimulating mucin release; 4) Northern blot analysis of messenger ribonucleic acids (mRNAs) with a mouse P2u receptor complementary deoxyribonucleic acid (cDNA) probe revealed a single specific band (2.8 kb), partial sequencing of which showed a great homology with those of human or mouse P2u receptors. We conclude that, although both ATP and UTP are equipotent in stimulating mucin release, their binding kinetics to the cell surface are quite different, suggesting the presence of a common binding domain which may be responsible for the mucin release by these nucleotides. We suggest that the P2u purinoceptor is likely to be responsible for mucin release by these nucleotides, probably via activation of phospholipase C.
The European WHO mental health programme and the World Health Report 2001: input and implications
Authors: Rutz Wolfgang
Published: June 2003

When the mental health programme of the World Health Organization (WHO) Regional Office for Europe was ‘resurrected’ in 1999, a review of the situation in the European Region of the WHO provided a surprisingly diverse picture. In this Region, which stretches from Greenland to Malta, from Ireland to Kamchatka, dramatic differences were noted in life expectancy and suicidality, income, housing, employment and social cohesion, as well as services, social support, human rights and the accessibility of basic care. In many societies, stigma and discrimination effectively excluded the mentally vulnerable from society and its basic services. Stigmatisation also hindered early intervention, rehabilitation and reintegration into society (WHO Regional Office for Europe, 1999, 2001).
vhnf1and Fgf signals synergize to specify rhombomere identity in the zebrafish hindbrain
Authors: Wiellette Elizabeth L. , Sive Hazel
Published: June 2003

Vertebrate hindbrain segmentation is a highly conserved process but the mechanism of rhombomere determination is not well understood. Recent work in the zebrafish has shown a requirement for fibroblast growth factor (Fgf)signaling and for the transcription factor variant hepatocyte nuclear factor 1 (vhnf1) in specification of rhombomeres 5 and 6(r5+r6). We show here that vhnf1 functions in two ways to subdivide the zebrafish caudal hindbrain domain (r4-r7) into individual rhombomeres. First, vhnf1 promotes r5+r6 identity through an obligate synergy with Fgf signals to activate valentino and krox20 expression. Second, vhnf1 functions independently of Fgf signals to repress hoxb1a expression. Although vhnf1 is expressed in a broad posterior domain during gastrulation, it promotes the specification of individual rhombomeres. This is achieved in part because vhnf1 gives cellular competence to respond to Fgf signals in a caudal hindbrain-specific manner.
Competing supplies of olive oil in the German market: An application of multinomial logit models
Authors: Ward Ronald W. , Briz Julian , de Felipe Isabel
Published: June 2003

Germany consumers are shown to differentiate their use of olive oil by country‐of‐origin, with Spain, Italy, and Greece being important competing suppliers. Effects of demographics, product characteristics, and information sources impact the probability of buying olive oil by origin. Multinomial logit models are estimated and used to show the gains (or loses), and point to the important role of promotions to Spain's olive oil. The importance of these variables are ranked for each country and Odds Ratios are used to compare the relatives gains among the major suppliers. [EconLit citations: Q130, Q180]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 393–406, 2003.
Mechanical, hygroscopic, and thermal properties of ultrathin polymeric substrates for magnetic tapes
Authors: Ma Tiejun , Bhushan Bharat
Published: June 2003

Mechanical, hygroscopic, and thermal properties of improved ultrathin polymeric films for magnetic tapes are presented. These films include poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and aromatic polyamide (ARAMID). PET films are currently the most commonly used polymeric substrate material for magnetic tapes, followed by PEN and ARAMID. The thickness of the films ranges from 6.2 to 4.8 μm. Tensile tests were run to obtain the Young's modulus, F5 value, strain at yield, breaking strength, and strain at break. The storage modulus, E′, and the loss tangent, tan δ, were measured using a dynamic mechanical analyzer (DMA) at temperature ranges of −50 to 150°C (for PET) and −50 to 210°C (for PEN and ARAMID) and at a frequency range of 0.016–28 Hz. Frequency–temperature superposition was used to predict the dynamic mechanical behavior of the films over a 28‐decade frequency range. Short‐term longitudinal creep behavior of the films during 10, 30, 60, and 300 s, 7 MPa, were measured at 25 and 55°C. Long‐term longitudinal creep measurements were performed at 25, 40, and 55°C for 100 h. The Poisson's ratio and 50‐h long‐term lateral creep were measured at 25°C/15% RH, 25°C/50% RH, 25°C/80% RH, and 40°C/50% RH. The in‐plane coefficient of hygroscopic expansion (CHE) at 25°C/20–80% RH and the coefficient of thermal expansion (CTE) at 30–70°C were measured for all the samples. The properties for all films are summarized. The relationship between the polymeric structure and the mechanical and physical properties are discussed, based on the molecular structure, crystallinity, and molecular orientation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3052–3080, 2003
Nanofiber‐reinforced polymers prepared by fused deposition modeling
Authors: Shofner M. L. , Lozano K. , Rodríguez‐Macías F. J. , Barrera E. V.
Published: June 2003

Vapor‐grown carbon fibers (VGCFs), a practical model nanofiber for single‐walled carbon nanotubes, were combined with an acrylonitrile–butadiene–styrene (ABS) copolymer to create a composite material for use with fused deposition modeling (FDM). Continuous filament feedstock materials were extruded from Banbury mixed composites with a maximum composition of 10 wt % nanofibers. Issues of dispersion, porosity, and fiber alignment were studied. SEM images indicated that the VGCFs were well dispersed and evenly distributed in the matrix and that no porosity existed in the composite material following FDM processing. VGCFs aligned both in the filament feedstock and in the FDM traces suggested that nanofibers, in general, can be aligned through extrusion/shear processing. The feedstock materials were processed into test specimens for mechanical property comparisons with unfilled ABS. The VGCF‐filled ABS swelled less than did the plain ABS at similar processing conditions due to the increased stiffness. The tensile strength and modulus of the VGCF‐filled ABS increased an average of 39 and 60%, respectively, over the unfilled ABS. Storage modulus measurements from dynamic mechanical analysis indicated that the stiffness increased 68%. The fracture behavior of the composite material indicated that the VGCFs act as restrictions to the chain mobility of the polymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3081–3090, 2003
Easy approach to chiral Michael adducts by Eu+3‐catalyzed conjugate addition
Authors: De Rosa Margherita , Palombi Laura , Acocella Maria Rosaria , Fruilo Marina , Villano Rosaria , Soriente Annunziata , Scettri Arrigo
Published: June 2003

Michael addition of enantiopure N‐acetoacetyl‐oxazolidin‐2‐ones is shown to take place in the presence of catalytic amounts of Eu+3 salts and complexes in high yields, very reduced reaction times, and moderate diastereoselectivity. The level of diastereoselectivity can be significantly enhanced by the suitable exploitation of the easy epimerization of the adducts in the presence of silica gel. Chirality 15:579–583, 2003. © 2003 Wiley‐Liss, Inc.
Iron chelation promoted by desazadesferrithiocin analogs: An enantioselective barrier
Authors: Bergeron Raymond J. , Wiegand Jan , Weimar William R. , McManis James S. , Smith Richard E. , Abboud Khalil A.
Published: June 2003

For patients who require lifelong blood transfusions, there is no efficient means, unless chelation therapy is employed, for elimination of excess iron. Alternatives to desferrioxamine, the currently accepted treatment for transfusional iron overload, are being investigated. The current article focuses on an enantiomeric pair of analogs of desferrithiocin, (+)‐(S)‐ and (−)‐(R)‐2‐(2,4‐dihydroxyphenyl)‐4,5‐dihydro‐4‐methyl‐4‐thiazolecarboxylic acid (4′‐hydroxydesazadesferrithiocin). The crystal structure corroborated the absolute configuration of the two compounds, (+) and (−) for the (S)‐ and (R)‐enantiomers, respectively. Job's plots established the tridentate nature of both analogs and circular dichroism spectra confirmed the ligands' antipodal relationship. (+)‐(S)‐4′‐Hydroxydesazadesferrithiocin is a more efficient deferration agent than is the (−)‐(R)‐enantiomer in a Cebus apella model of iron overload. Pharmacokinetic analyses and IC50 measurements in L1210 murine leukemia cells were undertaken in an effort to account for the contrast in efficacy between the two enantiomers. Some differences exist in the plasma pharmacokinetic parameters between the two analogs. However, a more plausible explanation may be the apparent differences in transport across the cell membrane; the IC50 value in L1210 cells of the (+)‐(S)‐enantiomer was at least 5‐fold lower than that of the (−)‐(R)‐compound. Chirality 15:593–599, 2003. © 2003 Wiley‐Liss, Inc.
Exciton coupling effects and conformational change of perhexyloligosilanes with optically active methyl(1‐naphthyl)phenylsilyl terminals
Authors: Oh Hyun‐Shik , Park Lee‐Soon , Kawakami Yusuke
Published: June 2003

Perhexyloligosilanes (R,R)‐(+)‐MeNpPhSi*(Hex2Si)nSi*PhNpMe (n = 2; (R,R)‐(+)‐4a, n = 4; (R,R)‐(+)‐6a, n = 6; (R,R)‐(+)‐8a) with chiral methyl(1‐naphthyl)phenylsilyl terminals were synthesized and characterized. The absorption wavelengths λmax by 1La,Ph transition of phenyl chromophore conjugated with oligosilane units in (R,R)‐(+)‐4a – (R,R)‐(+)‐8a show bathochromic shift of about 3–4 nm compared with those of the α,ω‐phenyl substituted perhexyloligosilanes Ph(Hex2Si)mPh (m = 4; 4b, m = 6; 6b, m = 8; 8b) having the same silicon chain length. Longer chain length induces the separated λmax of 1La,Ph from 1Bb,Np of naphthyl chromophore with positive exciton chiralities. In (R,R)‐(+)‐8a, although the extremum wavelengths λext of exciton coupling between 1Bb,Np and 1La,Ph are separated by about 80 nm, the compound retains the positive exciton chirality, which provides definite information on the absolute configuration of terminal chiral silicon atoms. Bulky terminal substituents and lowering the temperature affect the conformation of the main chain, inducing extended silicon backbone structure. Chirality 15:646–653, 2003. © 2003 Wiley‐Liss, Inc.
Surface charge analysis in eddy current problems
Authors: Fujishima Yasushi , Wakao Shinji
Published: June 2003

To estimate the characteristics of electric machines that have conductors of complicated shape, it is effective to analyze the surface charge related to eddy current phenomena. However, the eddy current field is generally treated as a quasi‐static field in which the displacement current is neglected and the electric field is not defined in the nonconductive region in the calculation process. Therefore, when we use only the A–ϕ finite element method (FEM) as a field analysis method, it is difficult to calculate the surface charge directly at the interface between conductive and nonconductive regions. In this paper, with this background, we propose a novel method of analysis of the surface charge based on both the A–ϕ FEM with edge elements and the integral equation. This approach enables us to precisely calculate the surface charge. Some numerical results that demonstrate the validity of the proposed method are also presented, such as the surface charge analysis of linear induction motors for evaluating the relationships among the surface charge, eddy current, and conductor shape. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(1): 59–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10173
A novel technique to implement frequency hopping planar antennas with a computer interface
Authors: Majumder A. , Chakravarty T. , Saran S. , Sanyal S. K.
Published: June 2003

In this paper, a novel configuration for a computer‐controlled frequency hopping microstrip antenna is presented. A circular microstrip antenna, loaded with a series LC tuned circuit in the form of a varactor diode with a metallic pin, is electronically tuned by sending digital words using the asynchronous serial communication facility of a computer. An analytical formulation, useful for the design of such an antenna, is presented. A computer interface circuit has been developed which, unlike embedded systems, offers flexibility in the choice of hopping sequence and facilitates remote operation. Design details and measured results are given. The results illustrate the feasibility of the proposed scheme to convert a low‐profile antenna into an adaptive antenna system. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 270–274, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11035
Verilog‐A implementation of a 2D spatiotemporal VCSEL model for system‐oriented simulations of optical links
Authors: Christen T. , Odermatt S. , Jungo M. , Erni D. , Baechtold W.
Published: June 2003

An implementation of a highly efficient spatiotemporal vertical‐cavity surface‐emitting laser (VCSEL) model in the circuit simulation environment of Cadence is presented. The VCSEL model, based on a set of modified rate equations, is written in Verilog‐A. It enables the association of the VCSEL model with transistor‐level models of the driver and detector circuits. Furthermore, the spatiotemporal nature of the model allows the generation of multimode responses and corresponding far‐field intensity profiles, which can be used to investigate fibre coupling and propagation mechanisms. An optimization of the VCSEL drive signal performed using the built‐in optimizer of Cadence is presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 304–308, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11044
An improved compact 2D full‐wave FDFD method for general guided wave structures
Authors: Pereda José A. , Vegas Angel , Prieto Andrés
Published: June 2003

Recently a finite‐difference frequency‐domain (FDFD) formulation has been reported for the dispersion analysis of uniform waveguides loaded with anisotropic dielectrics characterized by a diagonal tensor [4]. This formulation, which leads to an eigenvalue problem for the propagation constant γ, involves four field components. This paper shows that this formulation can be improved by taking advantage of the fact that the structures considered are strictly bidirectional waveguides and thus the dispersion analysis problem can be formulated as an eigenvalue problem for γ2, involving only two field components. This improved formulation is applied to several waveguiding structures and a comparison of the results with those obtained by the commercial simulator Agilent‐HFSS 5.6 show good agreement. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 331–335, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11052
Single‐mode four‐branch power divider with coupled wide‐angle waveguides
Authors: Huang Chia‐Chih , Chang Chin‐Yu , Wang Way‐Seen
Published: June 2003

A novel four‐branch single‐mode wide‐angle power divider, consisting of a symmetric Y‐branch waveguide with a phase front retarder around the junction and a central V‐shaped two‐branch waveguide located a coupling gap apart, is proposed. Low loss, large angle, and uniform output power distribution can be achieved by adjusting the gap between Y‐branch and V‐shaped two‐branch waveguides. Moreover, the proposed power divider can be used in wide‐bandwidth wavelength‐division‐multiplexing (WDM) systems. Also, the effect on the power‐dividing ratio is insensitive to fabrication tolerance. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 337–341, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11054
In vivo electroporation of the testis versus transgenic mice model in functional studies of spermatocyte‐specific hst70 gene promoter: A comparative study
Authors: Widlłak Wiesława , Ścieglińska Dorota , Vydra Natalia , Małusecka Ewa , Krawczyk Zdzisław
Published: June 2003

To determine whether DNA transfer to mouse testes by in vivo electroporation could be useful method for studying regulatory elements of genes specifically active in spermatocytes first we compared the expression pattern of a construct containing the EGFP reporter gene ligated to a fragment of the heat shock testis‐specific hst70 gene promoter, both in testis of transgenic mice and in testis electroporated in vivo. While in transgenic mice the EGFP was expressed in all seminiferous tubules in a cell‐ and stage‐specific manner, in the testes electroporated in vivo only small fraction of cells expressed this marker protein. In order to make a quantitative comparison between the specificity of these two experimental systems we used several vectors containing the CAT gene ligated to fragments of the hst70 gene 5′ upstream of DNA sequences which either promoted or did not activate expression of the reporter gene in the testes of transgenic mice. Also, as a reference opposite to spermatogenic cells we examined the expression pattern of the same set of vectors in the rat hepatoma FTO 2B cells. Although electroporated testes retain some spermatocyte‐specific features such as the ability to repress promoters which do not contain regulatory elements responsible for testis‐specific transcription, several important drawbacks of the method are evident. They include basal activity of constructs which are not transcribed in testes of transgenic mice and low overall transfection efficiency. This may hamper studies in which subtle changes in the expression pattern are under investigation. However, the in vivo electroporation of the testis can be useful for preliminary screening of constructs aimed to study in transgenic mice. Mol. Reprod. Dev. 65: 382–388, 2003. © 2003 Wiley‐Liss, Inc.
In vitro development and mitochondrial fate of macaca–rabbit cloned embryos
Authors: Yang Cai‐Xia , Han Zhi‐Ming , Wen Duan‐Cheng , Sun Qing‐Yuan , Zhang Ke‐Ying , Zhang Li‐Sheng , Wu Yu‐Qi , Kou Zhao‐Hui , Chen Da‐Yuan
Published: June 2003

Interspecies cloning may be used as an effective method to conserve highly endangered species and to support the development of non‐human primate animal models for studying therapeutic cloning and nuclear–cytoplasm interaction. The use of the monkey model for biomedical research can avoid legal, ethical, and experimental limitations encountered in a clinical situation. We describe in this study the in vitro development of macaca–rabbit embryos produced by fusing macaca fibroblasts with enucleated rabbit oocytes and examine the fate of mitochondrial DNA in these embryos. We show that macaca–rabbit cloned embryos can develop to the blastocyst stage when cultured in vitro in HECM10 +10% FBS and that mitochondrial DNA derived from donor somatic cells was detectable in cloned embryos throughout preimplantation development. These results suggest that (1) macaca fibroblast nuclei can dedifferentiate in enucleated metaphase II rabbit oocytes; (2) HECM10 +10% FBS can break through the development block and support the development of macaca–rabbit cloned embryos to blastocysts; and (3) donor‐cell‐derived mitochondrial DNA is not eliminated until blastocyst stage. Mol. Reprod. Dev. 65: 396–401, 2003. © 2003 Wiley‐Liss, Inc.
Effects of meiosis‐inhibiting agents and equine chorionic gonadotropin on nuclear maturation of canine oocytes
Authors: Songsasen N. , Yu I. , Gomez M. , Leibo S.P.
Published: June 2003

Experiments were conducted to determine the effects of meiosis‐inhibiting‐agents and gonadotropins on nuclear maturation of canine oocytes. The culture medium was TCM199 + 10 ng/ml epidermal growth factor supplemented with 25 μM β‐mercaptoethanol, 0.25 mM pyruvate, and 1.0 mM L‐glutamine (Basal TCM). Initially, oocytes were cultured in Basal TCM alone or in Basal TCM + dibutylryl cyclic adenosine monophosphate (0.5, 1, 5, or 10 mM dbcAMP) for 24 hr. Dibutylryl cAMP inhibited resumption of meiosis in a dose‐dependent manner; 60% of oocytes remained at the germinal vesicle (GV) stage after being cultured for 24 hr in 5 mM dbcAMP. The meiosis‐inhibitory effect of dbcAMP appeared to be reversible, as the oocytes resumed meiosis and completed nuclear maturation after being cultured for an additional 48 hr in its absence. Oocytes were then cultured in Basal TCM alone or in Basal TCM + roscovitine (12.5, 25, or 50 μM) for 24 hr. Although ∼60% of oocytes cultured in 25 μM roscovitine remained at the GV stage, this percentage was not significantly different from the 48% that also remained at the GV stage when cultured in its absence. Oocytes were cultured in Basal TCM + 25 μM roscovitine for 17 hr, exposed briefly to equine chorionic gonadotropin (eCG), and then cultured in Basal TCM for 48 hr. Short exposure of oocytes to eCG was beneficial, as it significantly increased the proportion of oocytes developing beyond germinal vesicle breakdown (P < 0.05) with ∼20–30% of these were metaphase I (MI) oocytes. Study of the kinetics of nuclear maturation demonstrated that large numbers of oocytes remained at MI even after being cultured for 52 hr following brief exposure to eCG. This study showed that in vitro maturation of canine oocytes can be somewhat improved by short exposure of oocytes to eCG. However, further studies are still required to derive effective methods to mature canine oocytes in vitro. Mol. Reprod. Dev. 65: 435–445, 2003. © 2003 Wiley‐Liss, Inc.
Solution of solute transport in unsaturated porous media by the method of characteristics
Authors: Kačur Jozef , Mahmood Mohammed Shuker
Published: June 2003

A degenerate convection‐diffusion problem is approximated using the scheme that is based on the relaxation method and also the method of characteristics. A mathematical model for solute transport in unsaturated porous media is included. Moreover, multiple site adsorption is considered. Convergence of the scheme is proved and numerical experiments in 1D and 2D are presented. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 732–761, 2003.
Multipole fast algorithm for the least‐squares approach of the method of fundamental solutions for three‐dimensional harmonic problems
Authors: Saavedra I. , Power H.
Published: June 2003

In this article we describe an improvement in the speed of computation for the least‐squares method of fundamental solutions (MFS) by means of Greengard and Rokhlin's FMA. Iterative solution of the linear system of equations is performed for the equations given by the least‐squares formulation of the MFS. The results of applying the method to test problems from potential theory with a number of boundary points in the order of 80,000 show that the method can achieve fast solutions for the potential and its directional derivatives. The results show little loss of accuracy and a major reduction in the memory requirements compared to the direct solution method of the least squares problem with storage of the full MFS matrix. The method can be extended to the solution of overdetermined systems of equations arising from boundary integral methods with a large number of boundary integration points. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 828–845, 2003.
Energy transfer in a single self‐aggregated photosynthetic unit
Authors: Hofmann Clemens , Francia Francesco , Venturoli Giovanni , Oesterhelt Dieter , Köhler Jürgen
Published: June 2003

The primary events of bacterial photosynthesis rely on the interplay of various specialized protein complexes organized in a supramolecular structure commonly termed the photosynthetic unit (PSU), which consists of the photochemical reaction center and of an associated antenna network. Employing single‐molecule spectroscopic techniques we have been able to observe the excitation‐energy transfer within a single PSU. From these findings we conclude that the building blocks of the PSU spontaneously form stable, functional aggregates in a non‐membrane environment.
Lef/Tcf‐dependent Wnt/β‐catenin signaling during Xenopus axis specification
Authors: Geng Xin , Xiao Lei , Lin Gu Fa , Hu Ruiying , Wang Jin Hu , Rupp Ralph A.W , Ding Xiaoyan
Published: June 2003

Though the Wnt/β‐catenin signaling pathway is known to play key roles during Xenopus axis specification, whether it signals exclusively through Lef/Tcf transcription factors in this process remains unclear. To investigate this issue, we generated transgenic frog embryos expressing green fluorescent protein (GFP) driven by a Lef/Tcf‐dependent and Wnt/β‐catenin‐responsive promoter. This promoter is highly sensitive and even detects maternal β‐catenin activity prior to the large‐scale transcription of zygotic genes. Unexpectedly, GFP expression was observed only in some, but not all, known Wnt/β‐catenin‐positive territories in Xenopus early development. Furthermore, ubiquitous expression of dominant Lef‐1 protein variants from transgenes revealed that zygotic Lef/Tcf activity is required for the ventroposterior development of Xenopus embryos. In summary, our results suggest that endogenous Wnt/β‐catenin activity does not result in obligatory Lef/Tcf‐dependent gene activation, and that the ventroposteriorizing activity of zygotic Wnt‐8 signaling is mediated by Lef/Tcf proteins.
Measurement of cytoplasmic copper, silver, and gold with a lux biosensor shows copper and silver, but not gold, efflux by the CopA ATPase of Escherichia coli
Authors: Stoyanov Jivko V , Magnani David , Solioz Marc
Published: June 2003

Copper, silver, gold and other heavy metals are potentially toxic to cells. Copper is also essential and cellular levels must be carefully controlled. In contrast, there is no known biological role for silver or gold and they have not been recognized as metals that are under homeostatic control. Using a luminescent biosensor based of the Vibrio fischeri lux gene cluster under the control of the Escherichia coli copA promoter/CueR metal‐responsive regulator, we could show that in E. coli, cytoplasmic copper and silver, but not gold, are regulated by the CopA ATPase, the major copper efflux pump.
Molecular mechanism for the enhancement of arbekacin resistance in a methicillin‐resistant Staphylococcus aureus
Authors: Matsuo Hiroaki , Kobayashi Miho , Kumagai Takanori , Kuwabara Masao , Sugiyama Masanori
Published: June 2003

We have clinically isolated a methicillin‐resistant Staphylococcus aureus (MRSA) K‐1 which exhibits enhanced arbekacin (Abk) resistance. In this study, we investigated a molecular mechanism for the overproduction of a bifunctional enzyme catalyzing both 2″‐O‐phosphorylation and 6′‐N‐acetylation of aminoglycoside antibiotics that is encoded by aacA‐aphD and designated [AAC(6′)/APH(2″)] and is expressed in MRSA K‐1. The sequence analysis of the 5′‐adjacent region of the aacA‐aphD structural gene in MRSA K‐1 showed that 12 bp are deleted from the aacA‐aphD promoter region when compared with that in MRSA B‐26, which exhibits lower resistance to Abk than K‐1. By artificially deleting the 12 bp from the corresponding region in MRSA B‐26, we confirmed that the strain increases Abk resistance to the same level as seen in MRSA K‐1, which suggests that the 12 bp deletion from the 5′‐adjacent region of the aacA‐aphD structural gene created a strong promoter to overexpress the bifunctional enzyme.
Unraveling thioredoxin‐linked metabolic processes of cereal starchy endosperm using proteomics
Authors: Wong Joshua H , Balmer Yves , Cai Nick , Tanaka Charlene K , Vensel William H , Hurkman William J , Buchanan Bob B
Published: June 2003

Application of a thiol‐specific probe, monobromobimane, with proteomics and enzyme assays led to the identification of 23 thioredoxin targets in the starchy endosperm of mature wheat seeds (Triticum aestivum cv. Butte), almost all containing at least two conserved cysteines. The identified targets, 12 not known to be thioredoxin‐linked, function in a spectrum of processes: metabolism (12 targets), protein storage (three), oxidative stress (three), protein degradation (two), protein assembly/folding (one) and unknown reactions (two). In addition to formulating metabolic pathways functional in the endosperm, the results suggest that thioredoxin acts in redox regulation throughout the life cycle of the seed.
Characterization of Pellino2, a substrate of IRAK1 and IRAK4
Authors: Strelow Astrid , Kollewe Christian , Wesche Holger
Published: June 2003

Interleukin‐1 (IL‐1) receptor‐associated kinases (IRAKs) are central components of Toll/IL‐1 receptor (TIR) signaling pathways. In an attempt to discover novel signal transducers in TIR signaling, we identified human Pellino2 as an interaction partner of IRAK4. Pellino2 interacts with kinase‐active as well as kinase‐inactive IRAK1 and IRAK4. Furthermore, Pellino2 is one of the first substrates identified for IRAK1 and IRAK4. Functional studies using overexpression or RNAi knock‐down of Pellino2 suggest a role of Pellino2 as a scaffolding protein similar to Pellino1. However, unlike Pellino1, Pellino2 does not seem to activate a specific transcription factor, but links TIR signaling to basic cellular processes.
Association of Caldendrin splice isoforms with secretory vesicles in neurohypophyseal axons and the pituitary
Authors: Landwehr Marco , Redecker Peter , Dieterich Daniela C. , Richter Karin , Böckers Tobias M. , Gundelfinger Eckart D. , Kreutz Michael R.
Published: June 2003

Caldendrin is a neuronal calcium‐binding protein, which is highly enriched in the postsynaptic density fraction and exhibits a prominent somato‐dendritic distribution in brain. Two additional splice variants derive from the caldendrin gene, which have unrelated N‐termini and were previously only detected in the retina. We now show that these isoforms are present in neurohypophyseal axons and on secretory granules of endocrine cells. In light of the described interaction of the Caldendrin C‐terminus with Q‐type Cav2.1 calcium channels these data suggest that this interaction takes place in neurohypophyseal axons and pituitary cells indicating functions of the short splice variants in triggering Ca2+ transients to a vesicular target interaction.
Substrate‐induced conformational changes in Escherichia coli arginyl–tRNA synthetase observed by 19F NMR spectroscopy
Authors: Yao Yong-Neng , Zhang Qing-Shuo , Yan Xian-Zhong , Zhu Guang , Wang En-Duo
Published: June 2003

The 19F nuclear magnetic resonance (NMR) spectra of 4‐fluorotryptophan (4‐F‐Trp)‐labeled Escherichia coli arginyl–tRNA synthetase (ArgRS) show that there are distinct conformational changes in the catalytic core and tRNA anticodon stem and loop‐binding domain of the enzyme, when arginine and tRNAArg are added to the unliganded enzyme. We have assigned five fluorine resonances of 4‐F‐Trp residues (162, 172, 228, 349 and 446) in the spectrum of the fluorinated enzyme by site‐directed mutagenesis. The local conformational changes of E. coli ArgRS induced by its substrates observed herein by 19F NMR are similar to those of crystalline yeast homologous enzyme.
Quality of care in institutionalized deliveries: the paradox of the Dominican Republic
Authors: Miller S. , Cordero M. , Coleman A.L. , Figueroa J. , Brito‐Anderson S. , Dabagh R. , Calderon V. , Cáceres F. , Fernandez A.J. , Nunez M.
Published: June 2003

Objectives: To better understand the paradox in the Dominican Republic of a relatively high maternal mortality ratio despite nearly universal institutionalized deliveries with trained attendants, a rapid assessment using an adaptation of the strategic assessment method was conducted. Methods: A multi‐disciplinary team reviewed national statistics and hospital records, inventoried facilities, and observed peripartum client–provider interactions at 14 facilities. Results: The major referral hospitals, where more than 40% of births in the country occur, were overcrowded and understaffed, with inexperienced residents overseeing care provided by medical students, interns and nurses. Uncomplicated labor and deliveries were overmedicalized, while complicated ones were not managed appropriately; emergencies were not dealt with in a timely fashion. In the peripheral hospitals physicians were seldom present and clients were either turned away or delivered by unprepared nursing staff. Providers in the busiest facilities suffered from compassion fatigue, and were demoralized and overworked. In all facilities, quality of care was lacking and the delivery and birthing process was dehumanized. Conclusions: Access and availability of institutional delivery alone is not enough to decrease MMR, it is also the quality of emergency obstetric care that saves lives.
Homoclinic bifurcations and uniform hyperbolicity for three-dimensional flows
Authors: Rodriguez Hertz Federico , Arroyo Aubin
Published: June 2003

In this paper we prove that any

C^1

vector field defined on a three-dimensional manifold can be approximated by one that is uniformly hyperbolic, or that exhibits either a homoclinic tangency or a singular cycle. This proves an analogous statement of a conjecture of Palis for diffeomorphisms in the context of

C^1

-flows on three manifolds. For that, we rely on the notion of dominated splitting for the associated linear Poincaré flow.

On prouve que tout champ de vecteurs

C^1

défini sur une variété de dimension trois peut être approché par un qui est uniformément hyperbolique ou bien par un qui présente soit une tangence homocline soit un cycle singulier. Ceci prouve, dans le contexte des flots 

C^1

sur les variétés de dimension trois, l’analogue d’une conjecture de Palis concernant les difféomorphismes. On s’appuie sur la notion de décomposition dominée pour le flot linéaire de Poincaré associé.
A quantitative analysis of valgus torque on the ACL: A human cadaveric study
Authors: Fukuda Yukihisa , Woo Savio L.‐Y. , Loh John C. , Tsuda Eiichi , Tang Peter , McMahon Patrick J. , Debski Richard E.
Published: June 2003

The loads needed to elicit a positive pivot shift test in a knee with an anterior cruciate ligament (ACL) rupture have not been quantified. The coupled anteriol tibial translation (ATT), coupled internal tibial rotation (ITR), and the in situ force in the ACL in response to a valgus torque, an inherent component of the pivot shift test, were measured in 10 human cadaveric knee specimens. Using a robotic/universal force–moment sensor testing system, valgus torques ranging from 0.0 to 10.0 N m were applied in nine increments on the intact and ACL‐deficient knee in flexion ranging from 0° to 90°. At 15° of knee flexion, the coupled ATT and ITR were significantly increased in the ACL‐deficient knee when compared to the intact knee. Coupled ATT increased a maximum of 291% (6.7 mm, p < 0.05), while coupled ITR increased a maximum of 85% (5.1°, p < 0.05). At 30°, the increases in coupled ATT and ITR were significant at valgus loads of 3.3 N m and greater with a maximum increase in coupled ATT of 137% (6.3 mm, p < 0.05) and a maximum increase in coupled ITR of 38% (3.6°, p < 0.05). At 45°, coupled ATT increased significantly (maximum of 69%, 4.4 mm, p < 0.05), but only at torques ⩾ 6.7 N m. The in situ force in the ACL was less than 20 N for all flexion angles when a torque between 3.3 and 5.0 N m was applied. Low valgus torque elicited tibial subluxation in the ACL‐deficient knee with low in situ ACL forces, similar to a positive pivot shift test. Thus, application of a valgus torque may be suitable to evaluate ACL‐deficient and ACL‐reconstructed knees, since subluxation can be achieved with minimal harm to the ACL graft. This work is important in understanding one load component needed for the pivot shift examination; further studies quantifying other load components are essential for better comprehension of the in vivo pivot shift examination. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.