bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complexity, parallel computation and statistical physics
Authors: Machta J. 
Published: June 2006

AbstractThe intuition that a long history is required for the emergence of complexity in natural systems is formalized using the notion of depth. The depth of a system is defined in terms of the number of parallel computational steps needed to simulate it. Depth provides an objective, irreducible measure of history that is applicable to systems of the kind studied in statistical physics. It is argued that physical complexity cannot occur in the absence of substantial depth and that depth is a useful proxy for physical complexity. The ideas are illustrated for a variety of systems in statistical physics. © 2006 Wiley Periodicals, Inc. Complexity 11: 46–64, 2006
The evolution of technology within a simple computer model
Authors: Arthur W. Brian , Polak Wolfgang 
Published: June 2006

AbstractTechnology—the collection of devices and methods available to human society—evolves by constructing new devices and methods from ones that previously exist, and in turn offering these as possible components—building blocks—for the construction of further new devices and elements. The collective of technology in this way forms a network of elements where novel elements are created from existing ones and where more complicated elements evolve from simpler ones. We model this evolution within a simple artificial system on the computer. The elements in our system are logic circuits. New elements are formed by combination from simpler existing elements (circuits), and if a novel combination satisfies one of a set of needs, it is retained as a building block for further combination. We study the properties of the resulting build out. We find that our artificial system can create complicated technologies (circuits), but only by first creating simpler ones as building blocks. Our results mirror Lenski et al.'s: that complex features can be created in biological evolution only if simpler functions are first favored and act as stepping stones. We also find evidence that the resulting collection of technologies exists at self‐organized criticality. © 2006 Wiley Periodicals, Inc. Complexity 11: 23–31, 2006
Relationship between protective effects of rosiglitazone on endothelium and endogenous nitric oxide synthase inhibitor in streptozotocin‐induced diabetic rats and cultured endothelial cells
Authors: Wang Shan , Jiang Jun‐Lin , Hu Chang‐Ping , Zhang Xiao‐Jie , Yang Dong‐Liang , Li Yuan‐Jian 
Published: June 2006

AbstractBackgroundPrevious investigations have indicated that the level of asymmetric dimethylarginine (ADMA) is increased in diabetic patients and animals, and rosiglitazone has a protective effect on the endothelium. In the present study, we tested the relationship between protective effects of rosiglitazone and ADMA in streptozotocin (STZ)‐induced diabetic rats and cultured endothelial cells.MethodsBlood samples were collected from carotid artery. Vasodilator responses to acetylcholine (ACh) in the isolated aortic rings were measured, and serum concentrations of glucose, lipid, nitrite/nitrate, ADMA and tumour necrosis factor‐α (TNF‐α) were determined. Cultured endothelial cells were treated with ADMA, and the concentrations of intercellular adhesion molecule (ICAM‐1), TNF‐α, and the activity of nuclear factor‐κB (NF‐κB) were determined.ResultsVasodilator responses to ACh were decreased markedly and the serum concentrations of TNF‐α, nitrite/nitrate and ADMA were increased significantly in diabetic rats. Rosiglitazone (3, 10 or 30 mg/kg) produced a significant reduction of the inhibition of vasodilator responses to ACh, but had no effect on the serum concentrations of glucose, lipid, nitrite/nitrate and ADMA in diabetic rats. ADMA (30 µM) significantly increased the activity of NF‐κB and elevated the levels of ICAM‐1 and TNF‐α, and pre‐treatment with rosiglitazone (10 or 30 µM) markedly inhibited the increased activity of NF‐κB and reduced the elevated levels of TNF‐α and ICAM‐1 induced by ADMA in cultured endothelial cells.ConclusionsRosiglitazone improves endothelial function in diabetic rats, which is related to the reduction of the inflammatory response induced by ADMA. Copyright © 2006 John Wiley & Sons, Ltd.
Cell and molecular regulation of the mouse blastocyst
Authors: Yamanaka Yojiro , Ralston Amy , Stephenson Robert O. , Rossant Janet 
Published: June 2006

AbstractAnimals use diverse strategies to specify tissue lineages during development. A common strategy is to partition maternally supplied and localized lineage determinants into progenitor cells. The mouse embryo appears to use a different, more regulative strategy to specify the first three lineages: the epiblast (EPI: future embryo), the trophectoderm (TE: future placenta), and the primitive endoderm (PE: future yolk sac). These lineages are specified during two successive differentiation steps leading to formation of the blastocyst. Here, we review classic and contemporary models of early lineage specification in the mouse, and describe recent efforts to understand the molecular regulation of these events. We describe evidence that trophectoderm differentiation bears resemblance to the process of epithelialization and describe the importance of apical/basal protein complexes in regulating this process. Next, we present a revised model of PE specification, and describe evidence that PE cells in the inner cell mass sort out to occupy their ultimate position on the surface of the EPI. Finally, we describe factors that reinforce these lineages and three distinct stem cell types that can be isolated from them. Together, these mechanisms guide the differentiation of the first lineages of the mouse and thereby set up tissues that will be important for the first steps of embryonic body patterning. Developmental Dynamics 235:2301–2314, 2006. © 2006 Wiley‐Liss, Inc.
BMP induction of cardiogenesis in P19 cells requires prior cell–cell interaction(s)
Authors: Angello John C. , Kaestner Stefanie , Welikson Robert E. , Buskin Jean N. , Hauschka Stephen D. 
Published: June 2006

AbstractMouse P19 embryonal carcinoma cells undergo cardiogenesis in response to high density and DMSO. We have derived a clonal subline that undergoes cardiogenesis in response to high density, but without requiring exposure to DMSO. The new subline retains the capacity to differentiate into skeletal muscle and neuronal cells in response to DMSO and retinoic acid. However, upon aggregation, these Oct 4‐positive cells, termed P19‐SI because they “self‐induce” cardiac muscle, exhibit increased mRNAs encoding the mesodermal factor Brachyury, cardiac transcription factors Nkx 2.5 and GATA 4, the transcriptional repressor Msx‐1, and cytokines Wnt 3a, Noggin, and BMP 4. Exposure of aggregated P19‐SI cells to BMP 4, a known inducer of cardiogenesis, accelerates cardiogenesis, as determined by rhythmic beating and myosin staining. However, cardiogenesis is severely inhibited when P19‐SI cells are aggregated in the presence of BMP 4. These results demonstrate that cell–cell interaction is required before P19‐SI cells can undergo a cardiogenic response to BMP 4. A concurrent increase in the expression of Msx‐1 suggests one possible process underlying the inhibition of cardiogenesis. The phenotype of P19‐SI cells offers an opportunity to explore new aspects of cardiac induction. Developmental Dynamics 235:2122–2133, 2006. © 2006 Wiley‐Liss, Inc.
Meta‐analysis of the nonword reading deficit in specific reading disorder
Authors: Herrmann Julia A. , Matyas Tom , Pratt Chris 
Published: June 2006

AbstractA meta‐analysis was conducted to investigate whether specific reading disorder (SRD) groups demonstrate a deficit in using phonological recoding strategies. Thirty‐four studies were reviewed that had compared the nonword reading performances of SRD groups with reading‐level matched (RL) control groups. The average nonword reading difference between groups across the total number of studies was moderate (d=0.65, N=2865). Three predictors of the size of group differences in nonword reading ability were identified. Studies that used passage reading tests to match groups for reading level found significantly less evidence for nonword reading deficits than studies that used word‐level reading accuracy tests. Secondly, there was a significant positive relationship between group differences in intelligence level (SRD‐RL control group) and effect sizes. Finally, group differences in age showed a significant negative association with effect magnitudes. The mean age, reading level and intelligence level of groups did not significantly predict nonword reading outcomes. It was concluded that there was evidence for nonword reading deficits in SRD groups, consistent with the claim that deficient development of phonological recoding strategies is a leading cause of reading difficulties. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of Polyether Cyclophanes through Rhodium‐Catalyzed Cross‐Alkyne Cyclotrimerization
Authors: Tanaka Ken , Sagae Hiromi , Toyoda Kazuki , Noguchi Keiichi 
Published: June 2006

AbstractCross‐cyclotrimerizations of ether‐linked α,ω‐diynes and dimethyl acetylenedicarboxylate in the presence of a catalytic amount of cationic rhodium(I)/H8‐BINAP complex give [7]–[21]polyether cyclophanes in good yield. [8]–[9]Ester cyclophanes were also synthesized from the corresponding α,ω‐diynes. The ratio of para‐, meta‐, and orthocyclophanes depends on the length and the structure of the α,ω‐diyne tether chain, whilst the effect of concentration on the yield of polyether cyclophanes appears to be small. X‐ray analysis revealed that a single crystal of [15]metacyclophane 4g was the chiral form and that of [5.5]metacyclophane 4k the racemic form, due to an absence of ring flip in the crystals. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Observer‐independent analysis of high‐resolution MR images of the human cerebral cortex: In vivo delineation of cortical areas
Authors: Walters Nathan B. , Eickhoff Simon B. , Schleicher Axel , Zilles Karl , Amunts Katrin , Egan Gary F. , Watson John D.G. 
Published: June 2006

AbstractUsing high‐resolution MRI, it is now possible to examine the living human cortex down to a resolution of less than 300 μm. Thus, in vivo imaging is now approaching the resolution that has been successfully used in histological analysis of the cerebral cortex for many years, e.g., low‐magnification light microscopy. This allows unprecedented views of cortical microstructure that reflect defined histological features, specifically, individual cortical layers. As in histological brain mapping, it is possible to use the changes in the cortical lamination patterns to define individual cortical areas. This allows in vivo neuroanatomical maps to be generated for individual subjects and precise correlation of the results from functional imaging studies in these subjects with their own microanatomical information. To this end, we adapted the well‐established observer‐independent cytoarchitectonic mapping techniques for defining cortical borders based on changes in cortical lamination for in vivo parcellation of high‐resolution structural MR images. Hum. Brain Mapping, 2007. © 2006 Wiley‐Liss, Inc.
Dose‐dependent attenuation of auditory phantom perception (tinnitus) by PET‐guided repetitive transcranial magnetic stimulation
Authors: Plewnia Christian , Reimold Matthias , Najib Arif , Brehm Bernhard , Reischl Gerald , Plontke Stefan K. , Gerloff Christian 
Published: June 2006

AbstractRecent data suggest that chronic tinnitus is a “phantom auditory perception” caused by maladaptive neuroplasticity and subsequent hyperactivity in an extended neuronal network including the primary auditory cortex, higher‐order association areas, and parts of the limbic system. It was suggested that attenuation of this tinnitus‐associated hyperactivity may offer a rational option for lasting tinnitus reduction. Here, we tested the hypothesis that tinnitus loudness can be attenuated by low‐frequency repetitive transcranial magnetic stimulation (rTMS) individually navigated to cortical areas with excessive tinnitus‐related activity as assessed by [15O]H2O positron‐emission tomography (PET). Nine patients with chronic tinnitus underwent this combined functional imaging and rTMS‐study. Group analysis of the PET data showed tinnitus‐related increases of regional cerebral blood flow in the left middle and inferior temporal as well as right temporoparietal cortex and posterior cingulum. Repetitive TMS was performed at 1 Hz and 120% of the motor threshold for 5, 15, and 30 min, navigated to the individual maximum of tinnitus‐related cortical hyperactivity. A noncortical stimulation site with the same distance to the ear served as sham control. Tinnitus loudness was reduced after temporoparietal, PET‐guided low‐frequency rTMS. This reduction, lasting up to 30 min, was dependent on the number of stimuli applied, differed from sham stimulation, and was negatively correlated with the length of the medical history of tinnitus in our patients. These data show the feasibility and effectiveness of rTMS guided by individual functional imaging to induce a lasting, dose‐dependent attenuation of tinnitus. Of note, these effects were related to stimulation of cortical association areas, not primary auditory cortex, emphasizing the crucial role of higher‐order sensory processing in the pathophysiology of chronic tinnitus. Hum Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.
The influences of thermophysical properties of porous media on superadiabatic combustion with reciprocating flow
Authors: Du Liming , Xie Maozhao 
Published: June 2006

AbstractThe influences of thermophysical properties of porous media on superadiabatic combustion with reciprocating flow is numerically studied in order to improve the understanding of the complex heat transfer and optimum design of the combustor. The heat transfer performance of a porous media combustor strongly depends on the thermophysical properties of the porous material. In order to explore how the material properties influence reciprocating superadiabatic combustion of premixed gases in porous media (short for RSCP), a two‐dimensional mathematical model of a simplified RSCP combustor is developed based on the hypothesis of local thermal non‐equilibrium between the solid and the gas phases by solving separate energy equations for these two phases. The porous media is assumed to emit, absorb, and isotropically scatter radiation. The finite‐volume method is used for computing radiation heat transfer processes. The flow and temperature fields are calculated by solving the mass, moment, gas and solid energy, and species conservation equations with a finite difference/control volume approach. Since the mass fraction conservation equations are stiff, an operator splitting method is used to solve them. The results show that the volumetric convective heat transfer coefficient and extinction coefficient of the porous media obviously affect the temperature distributions of the combustion chamber and burning speed of the gases, but thermal conductivity does not have an obvious effect. It indicates that convective heat transfer and heat radiation are the dominating ways of heat transfer, while heat conduction is a little less important. The specific heat of the porous media also has a remarkable impact on temperature distribution of gases and heat release rate. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 336–350, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20120
Advanced 3‐D CPC solar collector for thermal electric system
Authors: Saitoh Takeo S. , Kato Jun , Yamada Noboru 
Published: June 2006

AbstractIn this paper, the authors propose an innovative non‐tracking three‐dimensional compound parabolic concentrator (3‐D CPC) solar collector, which has excellent thermal efficiency for a high‐temperature range (100–200°C). In the past studies, in order to improve the thermal efficiency of the solar collector in a high‐temperature range, very high concentration ratios and tracking systems have been adopted. However, conventional high concentration solar collectors are not cost‐effective and are inappropriate for small‐rating thermal electric generation systems for residential use. The proposed 3‐D CPC collector has a moderate concentration ratio and does not need tracking. Initially, the tentative 3‐D CPC collector was fabricated and its thermal performance was tested. Next, numerical simulations of the optical characteristics of the 3‐D CPC collector were carried out via the ray‐tracing method. Finally, the specification of the optimal 3‐D CPC collector was clarified. Applications of the thermal electric system will also be mentioned. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 323–335, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20121
Internal gravity wave resonance of thermal convection fields in a square cavity with heat‐flux vibration
Authors: Matsumura Shota , Ishida Hideshi , Kimoto Hideo 
Published: June 2006

AbstractIn this paper, the thermal convection field and its resonance phenomena in a square cavity with sinusoidal heat‐flux vibration were numerically investigated. As the angular velocity ω is changed, the thermal convection field at Pr = 0.71,Ra = 106 is found to be classified into 5 regions. In particular, the field has the local maximum relative amplitude of midplane Nusselt's number at ωc = 350, which corresponds to the angular velocity of internal gravity wave ωr estimated by a theoretical equation proposed by Thorpe. This shows that the local enhancement is induced by internal gravity wave resonance. Such correspondence is observed for Ra ≥ 105,Ra ≥ 106 for Pr = 0.71, 7.1, respectively. For these ranges of Ra we propose a correlation equation, a function of Pr and Gr only, to estimate the resonant angular velocity. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 309–322, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20122
Quetiapine versus olanzapine for the treatment of negative symptoms in patients with schizophrenia
Authors: Sirota Pinkhas , Pannet Irit , Koren Ady , Tchernichovsky Eleonora 
Published: June 2006

AbstractNegative symptoms are considered the most debilitating and refractory aspect of schizophrenia, being associated with poor social, occupational and global outcomes. Conventional antipsychotics have limited efficacy against these symptoms and poor tolerability profiles. Atypical antipsychotics are an alternative treatment, and this 12‐week, randomised, flexibly dosed study compared the efficacy, safety and tolerability of quetiapine and olanzapine in this regard. Of the 40 patients who entered the study (32 male; 8 female), 19 were randomised to quetiapine (mean dose 637 mg/day, mean treatment duration 80 days) and 21 to olanzapine (mean dose 16 mg/day, mean treatment duration 78 days). Quetiapine and olanzapine were similarly effective: in each treatment group significant improvements at Week 12 were observed for negative symptom scores on the SANS and the PANSS, and for subscale scores of affective flattening and alogia on the SANS. Both treatments were well tolerated in this patient population, with no worsening of extrapyramidal symptoms in either case. Anxiety and insomnia were the most common adverse events (≥7% of patients in each group), but were not drug‐related. Although this is a small study with limited power, the results support the effectiveness of quetiapine and olanzapine in treating the negative symptoms of schizophrenia. Copyright © 2006 John Wiley & Sons, Ltd.
Loss of proline‐rich tyrosine kinase 2 function induces spreading and motility of epithelial prostate cells
Authors: de Amicis Francesca , Lanzino Marilena , Kisslinger Annamaria , Calì Gaetano , Chieffi Paolo , Andò Sebastiano , Mancini Francesco Paolo , Tramontano Donatella 
Published: June 2006

AbstractAlthough prostate carcinoma is an aggressive cancer preferentially metastasizing to the bones, many prostate tumors remain localized and confined to the prostate indefinitely. Prediction of the behavior of anatomically localized and moderately differentiated prostate tumors remains difficult because of lack of prognostic markers. Cell motility is an important step in the progression of epithelial tumor toward invasive metastatic carcinomas and changes in the expression and function of adhesion molecules contribute to the acquisition of a more malignant phenotype. Proline‐rich tyrosine kinase 2 (Pyk2) is implicated in regulating the organization of actin cytoskeleton, a process critical for cell migration, mitosis, and tumor metastasis. In this report, we investigated whether Pyk2 played a role in the acquisition of an aggressive phenotype in prostate cell. Data reported here demonstrate that loss of Pyk2 kinase function results in induction of cell motility and migration in EPN cells, a line of non‐transformed epithelial cells derived from human normal prostate tissue. Changes in motility and migration of prostate cells were associated with changes in the expression of several proteins involved in cell adhesion and reorganization of actin cytoskeleton. Ablation of Pyk2 kinase activity caused a dramatic decrease of the expression of E‐cadherin and IRS1 and an increase of the expression of α5‐integrin. In addition, a massive reorganization of actin cytoskeleton was observed. Our data indicate that Pyk2 plays a central role in the mechanism that regulate cell–cell and cell–substrate interaction and lack of its kinase activity induces prostate cells to acquire a malignant, migrating phenotype. J. Cell. Physiol. 209: 74–80, 2006. © 2006 Wiley‐Liss, Inc.
Comparison of bovine and porcine β‐lactoglobulin: a mass spectrometric analysis
Authors: Invernizzi Gaetano , Šamalikova Maria , Brocca Stefania , Lotti Marina , Molinari Henriette , Grandori Rita 
Published: June 2006

AbstractNano‐electrospray‐ionization mass spectrometry (nano‐ESI‐MS) is applied to comparison of bovine and porcine β‐lactoglobulin (BLG and PLG). The conformational and oligomeric properties of the two proteins under different solvent and experimental conditions are analyzed. The pH‐dependence of dimerization is described for the pH range 2–11. The results indicate maximal dimer accumulation at pH 6 for BLG and pH 4 for PLG, as well as a lower stability of the PLG dimer at pH 4 compared to BLG at pH 6. Conformational stability appears to be higher for BLG at acidic pH, but higher for PLG at basic pH. The higher stability of BLG at low pH is revealed by means of either chemical or thermal denaturation. Equilibrium folding intermediates of both proteins are detected. Finally, conditions are found that promote dissociation of the BLG dimer at pH 6 into folded monomers. Copyright © 2006 John Wiley & Sons, Ltd.