bluuebunny/crossref_metadata_2025 huggingface dataset:
Planetary gear set and automatic transmission simulation for machine design courses
Authors: Dennis Scott T. , Jensen Daniel D.
Published: December 2003

Due to their unique ability to provide a variety of gear ratios in a very compact space, planetary gear systems are seen in many applications from small powered screw drivers to automobile automatic transmissions. The versatile planetary gear device is often studied as part of an undergraduate mechanical engineering program. Textbook presentations typically illustrate how the different planetary gear components are connected. Understanding of the operation of the planetary gear set can be enhanced using actual hardware or simulations that show how the components move relative to each other. The Department of Engineering Mechanics at the United States Air Force Academy has developed a computer simulation of the planetary gear set and the Chrysler 42LE automatic transmission. Called “PG‐Sim,” the dynamic simulations complement a static textbook presentation. PG‐Sim is used in several of our courses and assessment data clearly indicates students' appreciation of its visual and interactive features. In this paper, we present an overview of PG‐Sim and then describe how the simulation courseware facilitates understanding of the planetary gear system. © 2003 Wiley Periodicals, Inc. Comput Appl Eng Educ 11: 144–155, 2003; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.10045
Antibiotic and Hemolytic Activity of a β2/β3 Peptide Capable of Folding into a 12/10‐Helical Secondary Structure
Authors: Arvidsson Per I. , Ryder Neil S. , Weiss H. Markus , Gross Gerhard , Kretz Olivier , Woessner Ralph , Seebach Dieter
Published: December 2003

Active peptide helices: The β‐nonapeptide H‐β3HPhe‐β2HVal‐β3HPhe‐β2HLeu‐β3HLys‐β2HLeu‐β3HLys‐β2HLeu‐β3HPhe‐OH with alternating β2‐ and β3‐amino‐acid residues has been tested for antibiotic and hemolytic activities. This represents the first case of biomimetic activity of a “mixed” β3/β2‐peptide.
Influence of Particles on Fluid Turbulence in Pipe and Diffuser Gas‐Solids Flow
Authors: Bohnet M. , Triesch O.
Published: December 2003

The influence of glass particles with different Reynolds numbers ReP = |u–uP|dPρ/η on axial and radial gas fluctuations as well as on Reynolds stresses was investigated for pipe and diffuser (continuous pipe expansion) gas‐solids flow. Measurements were carried out using phase‐Doppler anemometry distinguishing between velocity signals of the solid and fluid phase due to particle or tracer size. In fully developed pipe flow small particles (ReP = 60) damp turbulence but with increasing ReP vortex shedding behind the particles reduces attenuation and finally leads to turbulence enhancement. Behind the diffuser particles are decelerated and cause a steeper velocity gradient and, thus, an increase in turbulence. The measured data are compared to CFD calculations investigating Reynolds stress model and k‐ϵ model for the description of turbulence. Using small particles good agreement is achieved considering the momentum transfer between the phases. For larger particles the modeling of vortex shedding by turbulent particle source terms is needed for a satisfactory prediction.
Characterization of the Mixing Quality in Micromixers
Authors: Aubin J. , Fletcher D.F. , Bertrand J. , Xuereb C.
Published: December 2003

The laminar flow patterns and mixing performance of two different micromixers have been investigated and quantified using CFD. The micromixer geometries consist of a channel with either diagonal or asymmetric herringbone grooves on the channel floor. The numerical results show that a single helical flow is produced for the diagonal mixer, whereas the herringbone mixer creates a double helical flow, composed of an alternating large and small vortex. Particle tracking of a tracer shows that very little convective mixing occurs in the diagonal mixer. However, in the herringbone mixer, very good mixing occurs. Quantitative analysis methods that are traditionally used for characterizing macro‐scale static mixers have been employed. Calculation of the variance of tracer dispersion and the stretching has shown to be well adapted for quantifying the mixing in the micromixers. However, methods based on the deformation rate appear to be less suitable. The results are in excellent agreement with previous experimental findings.
Image Analysis: A Useful Tool for Porous Media Characterization
Authors: Montillet A. , Le Coq L.
Published: December 2003

Porous media are frequently encountered in chemical engineering processes. A prime requirement for an optimized design of these processes is a careful characterization of the porous medium structure. Among the few experimental techniques that can be used to this end, image analysis of consolidated samples proves to be an efficient but seldom used tool. It is currently applied in the fields of geology and materials science. The aim of this paper is to enlighten different examples of diagnostic applications of image analysis in the field of chemical engineering.
Organization of axonal projections from the anterolateral area of the bed nuclei of the stria terminalis
Authors: Dong Hong‐Wei , Swanson Larry W.
Published: December 2003

The anterolateral group of the bed nuclei of the stria terminalis (BSTalg) contains four distinct cell groups embedded within an undifferentiated anterolateral area (BSTal) that architectonically resembles a subjacent subcommissural zone (BSTsc). The overall distributions of axonal projections from various regions of the BSTal and from the BSTsc were determined with the Phaseolus vulgaris–leucoagglutinin (PHAL) anterograde tracer method and found to be identical. The BSTal and BSTsc share dense bidirectional connections, and also project heavily within the BST to the rhomboid and fusiform nuclei and the anteroventral and anterodorsal areas. They project less densely to the juxtacapsular, oval, magnocellular, ventral, and interfascicular BST nuclei. Outside the BST, brain areas receiving strong to moderate inputs from the BSTal and BSTsc fall into several functional groups: somatomotor system (nucleus accumbens, substantia innominata, ventral tegmental area, and retrorubral area and adjacent midbrain reticular nucleus), central autonomic control system (central amygdalar nucleus, dorsal lateral hypothalamic area, ventrolateral periaqueductal gray, parabrachial nucleus, and nucleus of the solitary tract), neuroendocrine system (paraventricular and supraoptic nuclei, hypothalamic visceromotor pattern generator network), and thalamocortical feedback loops (midline, medial, and intralaminar nuclei). The results indicate that the BSTal and BSTsc are parts of the same cell group (dorsal and ventral to the anterior commissure), which plays a role in coordinating visceral and somatic motor responses (during ingestive behaviors, for example), especially in response to noxious stimuli (learned anorexia associated with noxious stimuli). BSTal projections are distinct from those of the adjacent juxtacapsular, oval, fusiform, and rhomboid nuclei. J. Comp. Neurol. 468:277–298, 2004. © 2003 Wiley‐Liss, Inc.
Calcyon transcript expression in macaque brain
Authors: Oakman Scott A. , Meador‐Woodruff James H.
Published: December 2003

The anatomical distribution of the transcript encoding calcyon, a 24 kDa membrane protein associated with coupling D1‐like dopamine receptor activation to potentiated intracellular calcium release, was examined using in situ hybridization in the macaque brain. Calcyon mRNA is found to be abundantly distributed throughout the primate brain. In neocortex, moderately dense, diffuse signal is found in all areas, with increased intensity present in a superficial isodense band corresponding generally to cortical layers II and III. Increased intensity of signal is also seen in the pyramidal cell layers of medial prefrontal and anterior cingulate cortex. Calcyon mRNA is present abundantly in subcortical limbic areas such as the nucleus accumbens, septum, hypothalamus, amygdala, and hippocampus. Moderate calcyon transcript expression is seen in caudate and putamen, with lower levels in globus pallidus. Thalamic nuclei, including the reticular nucleus, express low to moderate levels. Very dense expression is noted in the substantia nigra pars compacta. Numerous brainstem regions express this transcript, notably monoaminergic nuclei including the locus coeruleus and dorsal raphe. The cerebellum has detectable levels of expression in both cortex and deep nuclei. Although calcyon is hypothesized as a means for D1‐like receptors to modulate “cross‐talk” with other neurotransmitter receptor systems, it is notable that abundant calcyon transcript is detected in brain regions not associated with D1‐like neurotransmission, particularly the substantia nigra pars compacta and other dopamine‐synthesizing cell groups. A substantial proportion of this may relate to the reported association of calcyon with the D5 receptor, or in addition, may suggest that calcyon has a wider role as a regulator of intracellular signal transduction. J. Comp. Neurol. 468:264–276, 2004. © 2003 Wiley‐Liss, Inc.
Performance evaluation of serial‐search strategies for the acquisition of DS/CDMA signals
Authors: Jibrail Waseem , Van Der Meer Andrew , Liyana‐Pathirana Ranjith
Published: December 2003

Search strategies for initial synchronization of direct sequence (DS) spread spectrum communication systems are compared, modelled and implemented using MATLAB then tested in the presence of additive white Gaussian noise (AWGN) and narrowband interference. The performance of these search strategies, namely, offset‐z‐search strategies and expanding alternate search strategies, in terms of the mean value of the search length is evaluated for different probabilities of detection. A truncated Gaussian probability phase distribution is assumed (asa prioriinformation about the correct phase) and the performance of these search strategies is tested for different standard deviations (σ) of the phase.

A novel search strategy, namely the offset‐z3, based on the offset z‐search strategy is introduced. Among all search strategies investigated the non‐uniform expanding alternate (NUEA) search strategy is found to perform best at high probability of detection. However, for a more peaked phase distribution, the offset‐z3‐search strategy is shown to offer better performance at low probability of detection. Outcomes of the simulated system support trends predicted by theory for the performance of different search strategies. Copyright © 2003 John Wiley & Sons, Ltd.
Implementation solutions for the interworking between MMS and streaming
Authors: Miraj‐E‐Mostafa
Published: December 2003

Multimedia messaging service (MMS) and streaming are forerunner multimedia applications in mobile communication. Use of streaming in the retrieval of continuous multimedia content of MMS is the identified optimum scope (extent) of interworking between MMS and streaming. The optimum interworking can remove a limitation visible in MMS—retrieving content requiring more storage space than available in a mobile terminal. This paper presents two different solutions for implementing the interworking. The implementation solutions are consistent with the existing mobile frameworks and the working principles and procedures of both MMS and streaming. Consistency is very important here not only to avoid creating isolated solution, but also to preserve user experience. This paper describes in detail how each of the solutions operates, including the process of using streaming in the MMS retrieval. Pros and cons of both the solutions are also analysed to compare those. Other important factors tackled in the analysis are implementation flexibility, complexity, terminal capability indication, and content adaptation. Copyright © 2003 John Wiley & Sons, Ltd.
Study of the reliability of a binary symmetric channel under non‐Gaussian disturbances
Authors: Al‐Smadi Adnan , Smadi Mahmoud M.
Published: December 2003

The field of digital and data communications is becoming increasingly dominant because digital transmission offers data processing options and flexibilities not available with analog transmission. The main feature of a digital communication system is that during a finite interval of time, it sends a waveform from a finite set of possible waveform. One of the most important and fundamental models of communications channels is the binary symmetric channel (BSC). An important measure of system performance in a digital communication system is the probability of error. In this paper, the probability of error, the reliability, the entropy and the channel capacity of a BSC model are studied under non‐Gaussian noise disturbances. Namely, Cauchy, Laplace and logistic distributions are considered. It is found that the reliability of the signaling system is low under non‐Gaussian noise distributions compared to the Gaussian noise distribution. Several methods were used to reduce the error probability. The amount of improvement in reliability using the reduction methods is higher in the case of Gaussian noise. In order to achieve high reliability under non‐Gaussian noise distribution, it is required to increase signal‐to‐noise ratio (SNR) and increase number of repetitions when sending the same signal different times. Finally, it is observed that increasing the reliability for Cauchy distribution noise has totally failed based on sending the same signal different times and summing the received signals. Copyright © 2003 John Wiley & Sons, Ltd.
Two algorithms for multi‐constrained optimal multicast routing
Authors: Tsai Kun‐Cheng , Chen Chyouhwa
Published: December 2003

Multimedia applications, such as video‐conferencing and video‐on‐demand, often require quality of service (QoS) guarantees from the network, typically in the form of minimum bandwidth, maximum delay, jitter and packet loss constraints, among others. The problem of multicast routing subject to various forms of QoS constraints has been studied extensively. However, most previous efforts have focused on special situations where a single or a pair of constraints is considered. In general, routing under multiple constraints, even in the unicast case is an NP‐complete problem. We present in this paper two practical and efficient algorithms, called multi‐constrained QoS dependent multicast routing (M_QDMR) and (multicasting routing with multi‐constrained optimal path selection (M_MCOP)), for QoS‐based multicast routing under multiple constraints with cost optimization. We provide proof in the paper that our algorithms are correct. Furthermore, through extensive simulations, we illustrate the effectiveness and efficiency of our proposals and demonstrate their significant performance improvement in creating multicast trees with lower cost and higher success probability. Copyright © 2003 John Wiley & Sons, Ltd.
Aggressive papillary male breast carcinoma on fine‐needle cytology sample
Authors: Zeppa Pio , Mascolo Massimo , Zabatta Assunta , Finelli Luigi , Vetrani Antonio , Palombini Lucio
Published: December 2003

Papillary carcinoma (PC) is a histological variant of breast carcinoma that is more frequently observed in males than in females, showing the same cytological features in both sexes. PC is characterized by a low grade of malignancy and a generally favorable course. We describe a case of male breast PC (MPC) diagnosed by fine‐needle cytology (FNC) in which some aggressive morphologically detectable features were associated with bland cytologic features of the tumor. FNC was performed on a 3 cm palpable mass of the left breast of a 55‐yr‐old male. FNC yielded abundant bloody material. Two smears were Diff‐Quik and Papanicolaou stained, others were used for immunocytochemical assessment of estrogen, progesterone, c‐erbB‐2, and Ki‐67; another was Feulgen stained for DNA ploidy. Smears were highly cellular, showing isolated cells and papillary structures. Cells showed tall and well‐defined cytoplasm with a columnar aspect, light anisonucleosis, coarse chromatin, and small nucleoli. Immunoperoxidase staining demonstrated positivity for estrogen (50%), negativity for progesterone, intense positivity for c‐erbB‐2, with specific membrane staining and positivity for Ki‐67 in more than 20% of the cells. DNA‐ploidy showed an aneuploid histogram with 5c exceeding rate (5cER) of 59% and 2c deviation index (2cDI) of 29%. Subsequent surgical pathology examination confirmed the cytological diagnosis of papillary carcinoma; moreover, it revealed neoplastic endolymphatic thrombi and infiltrative border of the tumor that reached the thoracic wall. Cytological features can suggest diagnosis of MPC on FNC samples. Immunocytochemical evaluation of c‐erbB‐2 and Ki‐67 and DNA ploidy evaluation on cytological smears might reveal a biological aggressiveness of PC despite the bland microscopic features of the tumor and this should influence the therapeutic procedure. Diagn. Cytopathol. 2003;29:360–363. © 2003 Wiley‐Liss, Inc.
Effects of redundant and nonredundant bimodal sensory stimulation on heart rate in bobwhite quail embryos
Authors: Reynolds Greg D. , Lickliter Robert
Published: December 2003

Research with both animal embryos and human infants has provided evidence that information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) can guide selective attention, perceptual learning, and memory during early development. How this facilitation is achieved remains relatively unexamined. This study examined the effects of redundant versus nonredundant bimodal stimulation on a measure of physiological arousal (heart rate) in bobwhite quail embryos. Results show that quail embryos exposed to concurrent but nonredundant auditory and visual stimulation during the late stages of incubation exhibit significantly elevated heart rates following stimulus exposure and during stimulus reexposure when compared to embryos exposed to redundant and synchronous audiovisual stimulation, unimodal auditory stimulation, or no supplemental prenatal sensory stimulation. These findings indicate a functional distinction between redundant and nonredundant bimodal stimulation during early development and suggest that nonredundant bimodal stimulation during the prenatal period can raise arousal levels, thereby potentially interfering with the attentional capacities and perceptual learning of bobwhite quail. In contrast, intersensory redundancy appears to foster arousal levels that facilitate selective attention and perceptual learning during prenatal development. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 304–310, 2003.
Peer rejection, temperament, and cortisol activity in preschoolers
Authors: Gunnar Megan R. , Sebanc Anne M. , Tout Kathryn , Donzella Bonny , van Dulmen Manfred M. H.
Published: December 2003

In this study, we examined a model that describes both direct and indirect pathways between children's temperament and activity of the hypothalamic–pituitary–adrenal (HPA) axis when children are in peer‐group settings. We hypothesize that in peer‐group settings both shy, inhibited and exuberant, undercontrolled children would exhibit higher cortisol levels, but these associations would operate through different pathways. Sociometric measures of peer rejection, salivary cortisol, and teacher reports of temperament were collected on 82 preschoolers. Children who were rejected by classmates had higher cortisol levels than the other children. The combination of Surgency and Poor Effortful Control (Effortful Control, reverse scored) was associated with elevated cortisol through a pathway mediated by aggressive interactions with peers and peer rejection. With the indirect path explained, the combination of Surgency and Poor Effortful Control also was directly and negatively associated with classroom cortisol levels. These results help explain why temperament associations with HPA activity have been variable and difficult to discern when children are assessed in peer‐group contexts. In these contexts, both direct and indirect pathways between temperament and cortisol need to be examined. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 343–358, 2003.
Effects of Atorvastatin on LDL sub‐fractions and peroxidation in type 1 diabetic patients: a randomised double‐blind placebo‐controlled study
Authors: Manuel‐y‐Keenoy Begoña , Van Campenhout Christel , Vertommen Jan , De Leeuw Ivo
Published: December 2003

Background

Patients with diabetes have an increased risk of both developing and dying from cardiovascular disease, and, currently, more aggressive lipid‐lowering targets are being recommended for these patients. Statins are widely and successfully used to correct dyslipidemia and prevent acute coronary episodes, but their effects on lipoprotein composition and peroxidation have not been fully investigated. We aimed to address this issue in type 1 diabetes mellitus.

Methods

T1DM patients with atherogenic index (total/HDL‐cholesterol > 4) were randomised double‐blindly to group A (n = 12) that received Atorvastatin 40 mg/day and group P (n = 12) that received placebo. They were monitored for blood biochemistry, LDL sub‐fractions and lipid peroxidation at inclusion, after 6 and after 12 weeks.

Results

In group A, the 40% decrease in serum total and LDL cholesterol and 20% decrease in triglycerides was accompanied by a decrease in serum α‐tocopherol from 46.4 ± 16.3 (mean ± SD) at inclusion to 32.2 ± 11.8 and 32.6 ± 14.0 µmol/L after 6 and 12 weeks respectively (p < 0.001 compared to group P by repeated‐measures ANOVA). Relative to LDL + VLDL cholesterol, α‐tocopherol increased by 40% (p < 0.001). Copper‐induced LDL + VLDL peroxidation increased from 4891 ± 1325 at inclusion to 6821 ± 2291 and 7040 ± 1712 nmol TBARS/mg LDL + VLDL cholesterol produced in 3 h (p = 0.004). LDL sub‐fractions shifted towards the less dense regions (p = 0.03).

Conclusions

These results suggest that Atorvastatin lowers the antioxidant capacity of LDL and VLDL in T1DM. The mechanisms underlying these changes merit further investigation and should be taken into account when planning long‐term primary prevention of CHD in diabetes. Copyright © 2003 John Wiley & Sons, Ltd.
Cadherin‐1, ‐2, and ‐11 expression and cadherin‐2 function in the pectoral limb bud and fin of the developing zebrafish
Authors: Liu Q. , Kerstetter A.E. , Azodi E. , Marrs J.A.
Published: December 2003

Cadherins are cell adhesion molecules that play important roles in development of a variety of organs, including the vertebrate limb. In this study, we analyze cadherin expression patterns in the embryonic zebrafish pectoral limb buds and larval pectoral fins by using both in situ hybridization and immunocytochemical methods. cadherin‐1 is detected in the epidermis of the embryonic limb buds and the larval pectoral fins. Cadherin‐2 is expressed in the pectoral limb bud mesenchyme and chondrogenic condensation. As development proceeds, cadherin‐2 expression is detected in newly differentiated pectoral fin endoskeleton, but its expression is greatly down‐regulated in the fin endoskeleton of larval zebrafish. cadherin‐11 is found in the basal region of the embryonic limb buds and in the proximal endoskeleton of the larval pectoral fins. Interfering with cadherin‐2 function using two specific antisense morpholino oligonucleotides disrupts formation of the chondrogenic condensation/endoskeleton, suggesting that cadherin‐2 is crucial for the normal development of the zebrafish pectoral fins. Developmental Dynamics 228:734–739, 2003. © 2003 Wiley‐Liss, Inc.
Thrombospondin‐1–deficient mice exhibit increased vascular density during retinal vascular development and are less sensitive to hyperoxia‐mediated vessel obliteration
Authors: Wang Shoujian , Wu Zhifeng , Sorenson Christine M. , Lawler Jack , Sheibani Nader
Published: December 2003

Thrombospondin‐1 (TSP1) is a natural inhibitor of angiogenesis. Its expression is most prominent during the late stages of vascular development and in the adult vasculature. Our previous studies have shown that TSP1 expression promotes a quiescent, differentiated phenotype of vascular endothelial cells. However, the physiological role TSP1 plays during vascular development and neovascularization requires further delineation. Here, we investigated the role of TSP1 during development of retinal vasculature and retinal neovascularization during oxygen‐induced ischemic retinopathy. The retinal vascular density was increased in TSP1‐deficient (TSP1‐/‐) mice compared with wild‐type mice. This finding was mainly attributed to increased number of retinal endothelial cells in TSP1‐/‐ mice. During oxygen‐induced ischemic retinopathy, the developing retinal vasculature of TSP1‐/‐ mice was less sensitive to vessel obliteration induced by hyperoxia but exhibited a similar level of neovascularization induced by normoxia compared with wild‐type mice. This finding is consistent with the similar pattern of VEGF expression detected in wild‐type and TSP1‐/‐ mice. Furthermore, the increased expression of TSP1 during development of retinal vasculature was not affected by oxygen‐induced ischemic retinopathy. In addition, the regression of ocular embryonic (hyaloid) vessels, as well as the newly formed retinal vessels during oxygen‐induced ischemic retinopathy, was delayed in TSP1‐/‐ mice. Therefore, TSP1 is a modulator of vascular homeostasis and its expression is essential for appropriate remodeling and maturation of retinal vasculature. Developmental Dynamics 228:630–642, 2003. © 2003 Wiley‐Liss, Inc.
Expression of a novel homeobox gene Ehox in trophoblast stem cells and pharyngeal pouch endoderm
Authors: Jackson Melany , Baird Janet W. , Nichols Jennifer , Wilkie Ron , Ansell John D. , Graham Gerry , Forrester Lesley M.
Published: December 2003

Ehox is an X‐linked paired like homeobox gene identified from a differentiating embryonic stem (ES) cell cDNA library and is expressed at low levels in the preimplantation blastocyst and in ES cells in vitro. In embryos at 6.5 days post coitum (dpc), Ehox expression was restricted to the extraembryonic ectoderm which correlates with high‐level expression in cultures of trophoblast stem cells. Extraembryonic expression becomes further restricted to the chorion and by 15.5 dpc Ehox is expressed in chorionic trophoblast of the labyrinth and spongiotrophoblast layers of the placenta. Ehox expression in the embryo proper first appears at 8.5 dpc in the anterior foregut endoderm and by 9.5 dpc is visible in pharyngeal pouches 2–4. By 10.5 dpc, Ehox expression becomes restricted to the ventral end of pouches 2 and 3. The data presented here is the first description of Ehox expression during embryogenesis and suggests a dual role for Ehox: (1) in trophoblast stem cells and compartments of the developing placenta, and (2) during development of the pharyngeal pouches, possibly delineating the area to become thymus. Development Dynamics 228:740–744, 2003. © 2003 Wiley‐Liss, Inc.
Alk8 is required for neural crest cell formation and development of pharyngeal arch cartilages
Authors: Payne‐Ferreira T.L. , Yelick P.C.
Published: December 2003

The type I TGFβ family member receptor alk8 acts in bone morphogenetic protein (BMP) signaling pathways to establish dorsoventral patterning in the early zebrafish embryo. Here, we present evidence that alk8 is required for neural crest cell (NCC) formation and that alk8 signaling gradients direct the proper patterning of premigratory NCCs. We extend our previous functional studies of alk8 to demonstrate that ectopic expression of constitutively active and dominant negative Alk8, consistently results in more medially or laterally positioned premigratory NCCs, respectively. We also demonstrate that patterning defects in premigratory NCCs, induced by alk8 misexpression, correlate with subsequent defects in NCC‐derived pharyngeal arch cartilages. Furthermore, an anteroposterior effect is revealed, where overexpression of Alk8 more severely affects anterior arch cartilages and decreased Alk8 activity more severely affects posterior arch cartilage formation. Ectopic expression studies of alk8 are supported by analyses of zygotic and maternal‐zygotic laf/alk8 mutants and of several BMP pathway mutants. Pharyngeal mesodermal and endodermal defects in laf/alk8 mutants suggest additional roles for alk8 in patterning of these tissues. Our results provide insight into alk8‐mediated BMP signaling gradients and the establishment of premigratory NCC mediolateral positioning, and extend the model for BMP patterning of the neural crest to include that of NCC‐derived pharyngeal arch cartilages. Developmental Dynamics 228:683–696, 2003. © 2003 Wiley‐Liss, Inc.
Syntheses, Characterizations, and Crystal Structures of Three New Metal Phosphonocarboxylates with a Layered and a Microporous Structure
Authors: Yang Bing‐Ping , Mao Jiang‐Gao , Sun Yan‐Qiong , Zhao Han‐Hua , Clearfield Abraham
Published: December 2003

Hydrothermal reactions of N‐(phosphonomethyl)proline (H3L) with MII (M = Cd, Pb, and Zn) chlorides resulted in three new metal amino‐phosphono‐carboxylates, namely, [Cd2LCl(H2O)] (1) and [Pb2Cl2(HL)] (2) with a layered structure, and [Zn7L6][Zn(H2O)6]2·16H2O (3) featuring a microporous structure built from centered octahedral Zn6(Zn) cluster anions. The cadmium(II) ions in complex 1 are octahedrally coordinated [Cd(1)O5Cl, Cd(2)O4NCl]. These cadmium octahedra form a 1D zigzag chain along the b‐axis through edge sharing, and such chains are further interconnected via phosphonate tetrahedra to form a <002> layer. The organic rings of the ligands are orientated to the interlayer space. Complex 2 also has a layered structure, in which Pb(1) is six‐coordinated by four phosphonate oxygen atoms and two carboxylate oxygen atoms from four ligands in a distorted octahedral geometry, three Pb−O distances are relatively longer than those of the remaining ones, whereas Pb(2) is six coordinated by three phosphonate oxygen atoms and one carboxylate oxygen from four ligands as well as two chloride anions in a distorted octahedral geometry, one Pb−O bond is much longer than the remaining ones. These two different types of PbII ions are further interconnected through bridging carboxylate and phosphonate groups to form a <200> layer. Complex 3 contains a novel heptanuclear zinc phosphonate cluster anion [Zn7L6]4− and two hexahydrated zinc(II) cations as well as 16 lattice water molecules. The seven ZnII cations in an anion form an unusual centered Zn6(Zn) octahedron, packing of such cluster anions creates micropores that are occupied by the hexahydrated zinc(II) cations and lattice water molecules. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reaction of Methyl Radicals with Metal Powders Immersed in Aqueous Solutions
Authors: Rusonik Irena , Polat Hurriyet , Cohen Haim , Meyerstein Dan
Published: December 2003

Methyl radicals radiolytically produced in aqueous solutions react efficiently with Cr0, Mn0, Fe0, Ni0, Cu0 and Zn0 powders immersed in the solution. The Cr0, Mn0, Fe0, Ni0 and Zn0 powders reduce the radicals to form methane. On the other hand the Cu0 powder seems to oxidize the radicals. Surprisingly a part of the energy absorbed by the Cr0, Fe0, Ni0 and Zn0 powders is transferred to the aqueous solution, thus increasing the radical yield. CH4, C2H4, C2H6, C3H6 and C3H8 are formed when an aqueous deaerated buffer solution, pH 4−5, is added to powders of analytical iron, zinc, manganese and chromium. The source of these gases is carbon traces present, as atoms or atom clusters, in the “analytical” metal powders. These carbon atoms, when present on the surface of the metals, are reduced by the metal particles in aqueous solutions. This mechanism might be the source of light alkanes and alkenes in the prebiotic era. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Modulation of the Communication between Redox Centers in a Tris(ferrocene)‐tren Ligand by Complexation of Lanthanide Ions
Authors: Heitzmann Marie , Moutet Jean‐Claude , Pécaut Jacques , Reynes Olivier , Royal Guy , Saint‐Aman Eric , Serratrice Guy
Published: December 2003

The tripodal ligand L built on the tren platform and bearing three chemically equivalent ferrocene units was prepared and characterized. Electrochemical investigations indicate that electrostatic communication occurs between the three ferrocene groups in L, which leads to the observation of two distinct voltammetric waves. The electrochemical communication between the three ferrocene moieties is disrupted in 1:1 (L:M3+) type complexes formed between L and Y3+ or Eu3+ metal cations and their electrochemical response tends towards that of a single three‐independent‐electrons oxidation wave. Modulation of the electrochemical properties of L in the presence of lanthanide ions might be exploited with a view to their electrochemical sensing in organic and aqueous media. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Advances in capillary electrophoretically mediated microanalysis
Authors: Van Dyck Sigrid , Kaale Eliangiringa , Nováková Soňa , Glatz Zdeněk , Hoogmartens Jos , Van Schepdael Ann
Published: December 2003

Recent developments in the use of capillary electrophoretic techniques for the in‐line study of enzyme reactions and derivatization protocols are reviewed. The article is divided into two parts: (i) in‐line enzyme reactions and (ii) in‐line derivatization. The first part introduces electrophoretically mediated microanalysis (EMMA) and discusses and illustrates the different modes of EMMA. A literature overview is provided, starting from 1996, and the investigated enzymes are classified into two tables based on the mode of engagement (i.e., continuous or transient) of the developed EMMA‐based assay. The second part starts with an introduction of the procedures and the nomenclature used in the area of in‐line derivatization protocols based on EMMA. Reported derivatization procedures are discussed and classified in tables, according to the functional group that is derivatized.
Silica‐based monoliths for capillary electrochromatography: Methods of fabrication and their applications in analytical separations
Authors: Allen Darin , El Rassi Ziad
Published: December 2003

This review article is intended to provide the reader with the recent advances made in the fabrication of silica‐based monolithic capillary columns for use in capillary electrochromatography (CEC). The silica‐based monoliths can be produced by three different approaches, namely (i) fusion of silica particles by thermal sintering, (ii) cross‐linking/entrapping silica particles in a packed bed using the sol‐gel process, and (iii) polymerization of silicon alkoxide precursors using the sol‐gel process. Thus far, approach (iii) is the most widely used for fabricating silica monoliths. After providing a thorough description of each of the three approaches used for the production of silica‐based monolithic capillary columns, the analytical separations performed by CEC on each kind of monolith are discussed.
Formation and Degradation Pathways of Intermediate Products Formed during the Hydropyrolysis of Glucose as a Model Substance for Wet Biomass in a Tubular Reactor
Authors: Sinag A. , Kruse A. , Schwarzkopf V.
Published: December 2003

In this study, glucose as a model substance for cellulose is pyrolyzed in supercritical water. The experiments are conducted in a continuously operated tubular reactor. From the usage of model substances, key information on the degradation pathway of biomass in supercritical water can be obtained. With this knowledge, it is tried to optimize a new method for gasification of wet biomass considering high yields of hydrogen and methane and also the suppressing of tar and char formation. The gaseous products mainly contain hydrogen, carbon dioxide, methane and a small amount of carbon monoxide. The effect of experimental conditions, such as pressure, temperature and reaction time, on the degradation of glucose is investigated in the experiments. The qualitative and quantitative composition of the gas and liquid phases formed are determined. The results show that only the amount of phenols increases with increasing temperature in the liquid phase. No complete gasification of glucose is achieved in the studied temperature range between 400 °C and 500 °C. The addition of alkali salts leads to a higher gas generation and to a decrease in carbon monoxide concentration via water‐gas‐shift reaction. A lower furfural concentration is obtained in the presence of KHCO3. Furthermore, this study shows that there is a wide conformity between the results of real and model biomass. A simplified scheme for glucose degradation is also presented with the help of the results found.
Combined Waste Air and Wastewater Treatment Plant for the Wood Panel Industry
Authors: Portenkirchner K. , Draxler J. , Somitsch W. , Stassen O.
Published: December 2003

In the last few years there has been a dramatic worldwide growth in the production of wood panels and especially of MDF (medium density fiberboard). The environmental aspects of this development have just recently reached the focus of industrial interest due to increasing environmental requirements by the authorities. The development of a new process which should completely close all production site water cycles and minimize the exhaust of air pollutants is reported.
Signaling, solidarity, and the sacred: The evolution of religious behavior
Authors: Sosis Richard , Alcorta Candace
Published: December 2003

Anthropologists have repeatedly noted that there has been little theoretical progress in the anthropology of religion over the past fifty years.1–7By the 1960s, Geertz2had pronounced the field dead. Recently, however, evolutionary researchers have turned their attention toward understanding the selective pressures that have shaped the human capacity for religious thoughts and behaviors, and appear to be resurrecting this long‐dormant but important area of research.8–19This work, which focuses on ultimate evolutionary explanations, is being complemented by advances in neuropsychology and a growing interest among neuroscientists in how ritual, trance, meditation, and other altered states affect brain functioning and development.20–26This latter research is providing critical insights into the evolution of the proximate mechanisms responsible for religious behavior. Here we review these literatures and examine both the proximate mechanisms and ultimate evolutionary processes essential for developing a comprehensive evolutionary explanation of religion.
Comparison of flammability measurements in vertical and horizontal exhaust duct in the ASTM E‐2058 fire propagation apparatus
Authors: Khan Mohammed M. , Bill Robert G.
Published: December 2003

The ASTM E‐2058 fire propagation apparatus (FPA) is capable of measuring time to ignition, chemical and convective heat release rates, mass loss rate, smoke generation rate, generation rates of CO, CO2 and O2 consumption rate, effective (chemical) heat of combustion and vertical fire propagation of materials. The original design of the FPA incorporated a vertical exhaust system with the measurement section finishing about 3.5 m from the floor. The exhaust measuring duct of the new FPA is horizontally oriented to enable its use in a wider range of laboratory environments. In this paper, the functionality of the new FPA was compared with the original FPA. The measurements and results indicate that the performance of the new FPA is equivalent to the original FPA. Copyright © 2003 John Wiley & Sons, Ltd.
Meshless numerical simulation of (full) potential flows in a nozzle by genetic algorithms
Authors: Winter G. , Abderramán J. C. , Jiménez J. A. , González B. , Benitez E. , Cuesta P.
Published: December 2003

A new procedure to solve some fluid problems formulated in elliptical partial differential equations is presented. A Genetic Algorithm with a dynamical encoding and a partial grid sampling is proposed for it as the advantages of solving the problem without using all grid nodes at the same time, and of adjusting step grid, without increasing the complexity. The designed method has immediate applications some self‐contained and some in combination with other traditional methods. Also, it provides a method alternative to the existing ones and uses simpler operations. Theoretical mathematical foundations of the problem are easily incorporated and that as a powerful characteristic of the method. In practice, our focus is to obtain an acceptable approximated solution. The method makes it possible to solveproblems with vague boundary conditions since no algebraic equation system is involved in the process. From the solution reached we have good information available to make an appropriate mesh to solve the problem through a traditional method. Comparative results for both linear and non‐linear potential flow problems inside a nozzle are given. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of paracasein degradation on sensory properties of Gouda cheese
Authors: Cichosz Grażyna , Zalecka Anna , Kornacki Mariusz
Published: December 2003

The relation between the sensory quality of Gouda cheese and the extent of paracasein degradation, i. e., the content of soluble N, peptide N, amino acid N and amine N, was studied. The above‐mentioned parameters of paracasein degradation differently determined the sensory properties of Gouda cheese. The flavour of cheese after 6‐week ripening depended to the largest extent on the content of amine N and soluble N. The effect of the content of peptide N on cheese flavour was smaller but statistically significant. Also the smell of Gouda cheese was to the largest extent correlated to the content of amine N. A dependence between smell and the content of peptide N was found only in the cheeses after 4‐week ripening. None of the sensory quality parameters of the examined cheeses depended on the content of amino acid N.
In vitro influence of spices and spice‐active principles on digestive enzymes of rat pancreas and small intestine
Authors: Ramakrishna Rao R. , Platel Kalpana , Srinivasan K.
Published: December 2003

In vitro influence of 14 individual spices (curcumin, capsaicin, piperine, garlic, onion, ginger, mint, coriander, cumin, ajowan, fennel, fenugreek, mustard, and asafoetida) on the activities of digestive enzymes of rat pancreas and small intestine was examined by including them in the reaction mixture at two different concentrations. A majority of spices enhanced the activity of pancreatic lipase and amylase when they are directly in contact with the enzyme. It is inferred that this positive influence on the activity of enzymes may have a supplementary role in the overall digestive stimulant action of spices, besides causing an enhancement of the titres of digestive enzymes in pancreatic tissue.
Determination of glutathione peroxidase activity in human milk
Authors: Torres Angeles , Farré Rosaura , Lagarda María Jesús , Monleón Javier
Published: December 2003

An analytical method for determining glutathione peroxidase (GPx) (EC 1.11.1.9) activity in whole blood has been adapted to human milk samples. The values obtained for precision (relative standard deviation: 8.4%), linearity and accuracy (recovery: 90.4%) indicate the adequacy of the method for the mentioned purpose. The method was applied to 11 human milk samples obtained in the range from 6 to 135 days post partum. The resulting GPx activities (83.3 ± 23.6 U/L) did not correlate to the selenium content of the samples, though a reciprocal correlation was found between the duration of lactation and milk GPx activity.
A dynamic principal components analysis based on multivariate matrix normal dynamic linear models
Authors: Salvador Manuel , Gallizo Jose Luis , Gargallo Pilar
Published: December 2003

In this paper, we propose a multivariate dynamic linear model (MDLM) that allows us to carry out a dynamic principal components analysis in a set of multivariate time series and to analyse the similarity in their evolution once the influence of non‐stationarity in each of them has been removed. In order to illustrate the methodology, we consider the distribution of value added of the firms operating in the Spanish Transport Material Manufacturing sector. Copyright © 2003 John Wiley & Sons, Ltd.
Inference for some multivariate ARCH and GARCH models
Authors: Vrontos I. D. , Dellaportas P. , Politis D. N.
Published: December 2003

Multivariate time‐varying volatility models have attracted a lot of attention in modern finance theory. We provide an empirical study of some multivariate ARCH and GARCH models that already exist in the literature and have attracted a lot of practical interest. Bayesian and classical techniques are used for the estimation of the parameters of the models and model comparisons are addressed via predictive distributions. We provide implementation details and illustrations using daily exchange rates of the Athens exchange market. Copyright © 2003 John Wiley & Sons, Ltd.
Progressive telomere shortening occurs in cultured rat microglia, but not astrocytes
Authors: Flanary Barry E. , Streit Wolfgang J.
Published: December 2003

Normal somatic cells have a finite replicative capacity. With each cell division, telomeres shorten progressively until they reach a critical length, at which point the cells enter replicative senescence. Some cells maintain their telomeres by the action of the telomerase enzyme. Glia, particularly microglia, are the only adult cell types in the central nervous system (CNS) that exhibit a significant mitotic potential, and are thus susceptible to telomere shortening. In this study, we show that telomere shortening accompanied by low to moderate telomerase activity, and ultimately senescence, occurs in rat microglia in vitro. When microglia are stimulated to divide with the mitogen granulocyte macrophage‐colony stimulating factor (GM‐CSF), longer telomeres are allowed to shorten, while shorter telomeres are lengthened. Telomerase activity is nearly 3‐fold higher in GM‐CSF‐stimulated microglia initially, relative to unstimulated controls, and then declines to levels below those seen in controls before increasing again. Telomere attrition is also more rapid when microglia are grown in culture dishes of increasing size. Fluorescence in situ hybridization (FISH) analysis indicates that a nearly 3‐fold variation in both inter‐ and intra‐chromosomal telomere length exists in microglia. In contrast to microglia, cultured astrocytes exhibit a cyclical pattern of telomere lengthening and shortening over time, corresponding to a similar cycle of higher and lower telomerase activity. When astrocytes are passaged, mean telomere length increases initially from passage 1–2, remaining constant until passage 5, while the shortest telomeres are continually lengthened. In conclusion, the telomere shortening evident in microglia is accompanied by their progression to senescence by 32 days in vitro. In contrast, astrocytes, perhaps due to greater telomerase activity, have longer life spans and may be passaged repeatedly before entering senescence. Our findings provide an impetus to investigate the possibility that microglial telomere shortening may occur in vivo. © 2003 Wiley‐Liss, Inc.
Chemo‐ and Enzyme‐Catalyzed Reactions Revealing a Common Temperature‐Dependent Dynamic Solvent Effect on Enantioselectivity
Authors: Cainelli Gianfranco , Galletti Paola , Giacomini Daria , Gualandi Andrea , Quintavalla Arianna
Published: December 2003

The enantiomeric ratio E of enzyme‐catalyzed (Candida antarctica lipase and lipase PS) and chemo‐catalyzed (L‐proline‐based diamines) acylation reactions of 1‐(naphthalen‐2‐yl)ethanol, 2‐phenylpropanol, and 2‐benzylpropane‐1,3‐diol is dependent on solvent and temperature. Plots of ln E vs. 1/T showed the presence of inversion temperatures (Tinv). The Tinv values for the bio‐catalyzed and the chemo‐catalyzed reactions are fairly in agreement, and correspond as well to the TNMR values obtained by variable‐temperature 13C‐NMR experiments on the substrates in the same solvent of the resolution. This result demonstrates that clustering effects in the substrate solvation manage the chemical and the enzymatic enantioselectivity, and, moreover, that the solutesolvent cluster is always the real reacting species in solution for chemical as well as for enzymatic reactions.