bluuebunny/crossref_metadata_2025_split huggingface dataset:
A binary‐based on‐chip CNN solution for pixel‐level snakes
Authors: Brea V. M. , Laiho M. , Vilariño D. L. , Paasio A. , Cabello D. 
Published: June 2006

AbstractThis paper introduces a binary‐based on‐chip cellular neural network (CNN) solution for pixel‐level snakes. Every cell in the array comprises circuitry for B/W and grey‐scale processing. The B/W processing is performed with a positive range high‐gain discrete‐time (DT)CNN model with 1‐bit of programmability. The grey‐scale processing is executed on a dedicated sub‐cell. The design efforts are mainly focused on area consumption and processing speed. The result is a chip with a resolution of 9 × 9 cells in a 0.18 µm CMOS technology process and a density of more than 700cells/mm2. Simulations at schematic level lead to a time of less than 100ns for every DTCNN step. The peak power dissipation is kept at a few watts in a hypothetical chip of 128 × 128 cells. Copyright © 2006 John Wiley & Sons, Ltd.
Digital implementation of cellular sensor‐computers
Authors: Földesy Péter , Zarándy Ákos , Rekeczky Csaba , Roska Tamás 
Published: June 2006

AbstractA bit‐sliced digital implementation method of the cellular sensor‐computer is proposed. The proposed sensor‐computer architecture is analysed, and an implementation example is introduced. The analogue and the digital implementation methods are compared. It is found that on or below 0.18 µm technology the digital implementation of the cellular sensor‐computer is a viable alternative to the analogue versions in general‐purpose designs. Copyright © 2006 John Wiley & Sons, Ltd.
Cellular non‐linear networks for microcirculation applications
Authors: Sapuppo F. , Bucolo M. , Intaglietta M. , Fortuna L. , Arena P. 
Published: June 2006

AbstractCellular nonlinear network methodology and related technology was used for the implementation of a real‐time image processing system for the study of structural and functional parameters in the microcirculation. The observation of these parameters is basic in the description and characterization of the physiological phenomena occurring in the peripheral vascular network at a micrometric scale. They contribute to the understanding of the global cardiovascular regulatory system for both experimental and clinical applications. The aim of this new CNN‐based approach is to implement a real‐time system that is based on automated image processing algorithms that overcome the limits of the conventional invasive, manual, and operator dependant methods. It would also allow an objective protocol in thein vivoexperiments. These conditions are necessary in biological studies in order to make the experimental results reproducible and comparable. An algorithm was implemented, by exploiting the CNN structure potentiality, in order to characterize the morphology of the capillary maps, to determine the red blood cells density in blood (Hematocrit), and to calculate red blood cells velocity (RBCV) in capillaries from image sequences captured duringin vivoexperiments by intravital microscopy. The algorithm was designed and tested using a CNN simulator and then optimized and implemented via hardware on the ACE16k CNN chip. The final results of the image processing were furthermore compared with measurements obtained with conventional, manual methods used in microvascular studies. Copyright © 2006 John Wiley & Sons, Ltd.
Formation of three‐dimensional fetal myocardial tissue cultures from rat for long‐term cultivation
Authors: Just Lothar , Kürsten Anne , Borth‐Bruhns Thomas , Lindenmaier Werner , Rohde Manfred , Dittmar Kurt , Bader Augustinus 
Published: June 2006

AbstractThree‐dimensional cardiomyocyte cultures offer new possibilities for the analysis of cardiac cell differentiation, spatial cellular arrangement, and time‐specific gene expression in a tissue‐like environment. We present a new method for generating homogenous and robust cardiomyocyte tissue cultures with good long‐term viability. Ventricular heart cells prepared from fetal rats at embryonic day 13 were cultured in a scaffold‐free two‐step process. To optimize the cell culture model, several digestion protocols and culture conditions were tested. After digestion of fetal cardiac ventricles, the resultant cell suspension of isolated cardiocytes was shaken to initialize cell aggregate formation. In the second step, these three‐dimensional cell aggregates were transferred onto a microporous membrane to allow further microstructure formation. Autonomously beating cultures possessed more than 25 cell layers and a homogenous distribution of cardiomyocytes without central necrosis after 8 weeks in vitro. The cardiomyocytes showed contractile elements, desmosomes, and gap junctions analyzed by immunohistochemistry and electron microscopy. The beat frequency could be modulated by adrenergic agonist and antagonist. Adenoviral green fluorescent protein transfer into cardiomyocytes was possible and highly effective. This three‐dimensional tissue model proved to be useful for studying cell–cell interactions and cell differentiation processes in a three‐dimensional cell arrangement. Developmental Dynamics 235:2200–2209, 2006. © 2006 Wiley‐Liss, Inc.
Isolation of essential oil and supercritical carbon dioxide extract of Juniperus communis L. fruits from Montenegro
Authors: Damjanović Biljana , Skala Dejan , Baras Josip , Petrović‐Djakov Dušanka 
Published: June 2006

AbstractRipe fruits (berries) of common juniper (Juniperus communis L.) from northern Montenegro were extracted by hydrodistillation and by supercritical carbon dioxide (SC‐CO2) in a single‐stage separation system. The composition of the extracts was evaluated by GC‐FID and GC‐MS. A total of 38 different compounds were identified and significant differences (qualitative and quantitative) were observed between the hydrodistilled oil and the SC‐CO2 extracts. In the hydrodistilled oil, major compounds were: α‐pinene (28.6–38.2%), sabinene (15.7–20.5%) and myrcene (7.2–18.2%). In the SC‐CO2 extracts, major compounds were: α‐pinene (7.7–30.3%), myrcene (4.5–20.5%) and germacrene B and D (∼6%). The analysis of the results has shown that the grinding process has a significant influence on the yield and chemical composition of essential oil. In SC‐CO2 extraction different pressures were applied and the best process performance regarding chemical composition of the extract and its organoleptic quality was obtained at 90 bar and 40 C in the extraction vessel. Copyright © 2006 John Wiley & Sons, Ltd.
The reaction mechanism of iron and manganese superoxide dismutases studied by theoretical calculations
Authors: Rulíšek Lubomír , Jensen Kasper P. , Lundgren Kristoffer , Ryde Ulf 
Published: June 2006

AbstractWe have studied the detailed reaction mechanism of iron and manganese superoxide dismutase with density functional calculations on realistic active‐site models, with large basis sets and including solvation, zero‐point, and thermal effects. The results indicate that the conversion of O to O2 follows an associative mechanism, with O directly binding to the metal, followed by the protonation of the metal‐bound hydroxide ion, and the dissociation of 3O2. All these reaction steps are exergonic. Likewise, we suggest that the conversion of O to H2O2 follows an at least a partly second‐sphere pathway. There are small differences in the preferred oxidation and spin states, as well as in the geometries, of Fe and Mn, but these differences have little influence on the energetics, and therefore on the reaction mechanism of the two types of superoxide dismutases. For example, the two metals have very similar reduction potentials in the active‐site models, although they differ by 0.7 V in water solution. The reaction mechanisms and spin states seem to have been designed to avoid spin conversions or to facilitate them by employing nearly degenerate spin states. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1398–1414, 2006
Optimisation of anaerobic/anoxic/oxic process to improve performance and reduce operating costs
Authors: Peng Yongzhen , Wang Xiaolian , Wu Weimin , Li Jun , Fan Jie 
Published: June 2006

AbstractA laboratory‐scale anaerobic/anoxic/oxic reactor system was used to treat synthetic brewery wastewater for 1 year. The objectives were to enhance denitrifying phosphorus removal, improve biological nutrient removal and reduce operating costs. Three operational strategies were tested: (1) controlling nitrate recirculation to stimulate the growth of denitrifying phosphate‐accumulating organisms; (2) adjusting the volume ratio of the anaerobic/anoxic/oxic zones to enhance anoxic P uptake; (3) bypassing a part of the influent flow into the anoxic zone to maximise anoxic P uptake and denitrification. The results showed that not only was anoxic P uptake enhanced but also energy consumption for aeration could be reduced when the anoxic effluent NO3−‐N concentration was controlled between 1 and 3 mg L−1. The optimal volume ratio of the anaerobic/anoxic/aerobic zones in this system was found to be 1:1:2. The optimal bypass flow ratio was 0.32. The results indicated that the optimal strategies could improve treatment performance and reduce operational costs, but there was still a challenge to treat wastewater with low C/N ratio. Copyright © 2006 Society of Chemical Industry
Apomorphine protects against 6‐hydroxydopamine‐induced neuronal cell death through activation of the Nrf2‐ARE pathway
Authors: Hara Hirokazu , Ohta Mitsuhiro , Adachi Tetsuo 
Published: June 2006

AbstractNF‐E2‐related factor‐2 (Nrf2), a basic leucine zipper transcription factor, is involved in the expression of numerous detoxifying and antioxidant genes via the antioxidant response element (ARE). Apomorphine (Apo), a dopamine D1/D2 receptor agonist, is used for clinical therapy of Parkinson's disease. On the other hand, Apo is a potent radical scavenger and has protective effects on oxidative stress‐induced cell death. Previously, we have reported that pretreatment of human neuroblastoma SH‐SY5Y cells with Apo enhances protection against 6‐hydroxydopamine (6‐OHDA)‐induced cell death. In this study, we investigated whether the Nrf2‐ARE system is involved in the protection by Apo. Pretreatment of SH‐SY5Y cells with Apo suppressed 6‐OHDA‐induced cell death in a dose‐dependent manner. However, neither SCH23390, a dopamine D1 receptor antagonist, nor sulpiride, a dopamine D2 receptor antagonist, prevented the protective effect of Apo. Apo stimulated the translocation of Nrf2 into the nucleus and the transactivation of the ARE. The expression of heme oxygenase‐1 (HO‐1) was dose dependently induced by Apo. Moreover, we found that the activation of the ARE and the induction of HO‐1 mRNA caused by Apo were suppressed in the presence of the antioxidant N‐acetylcysteine and also that Apo produced intracellular reactive oxygen species (ROS), indicating that the low level of ROS produced by Apo may play a critical role in this phenomenon. Taken together, our findings suggest that not only the function as a radical scavenger but also the function as an Nrf2‐ARE pathway activator may be involved in the neuroprotective effects of Apo. © 2006 Wiley‐Liss, Inc.
Enhanced activation of Ca2+/Calmodulin‐dependent protein kinase II upon downregulation of cyclin‐dependent kinase 5‐p35
Authors: Hosokawa Tomohisa , Saito Taro , Asada Akiko , Ohshima Toshio , Itakura Makoto , Takahashi Masami , Fukunaga Kohji , Hisanaga Shin‐ichi 
Published: June 2006

AbstractCyclin‐dependent kinase 5 (Cdk5)‐p35 is downregulated in cultured neurons by N‐methyl‐d‐aspartate (NMDA) via the proteasomal degradation of p35. However, it is not known where in neurons this downregulation occurs or the physiologic meaning of the reaction. We show the enrichment of Cdk5 and p35 in the postsynaptic density and the NMDA‐induced degradation of postsynaptic p35 using brain slices and cultured neurons. To evaluate the role of this downregulation, we examined the relationship between Ca2+/calmodulin‐dependent protein kinase II (CaMKII) activation and Cdk5 downregulation, as events downstream from NMDA stimulation. Glutamate or NMDA stimulation induced CaMKII autophosphorylation over a time course that mirrored the time course of p35 degradation. To simulate the downregulation of postsynaptic Cdk5 in invitro experiments, we used the Cdk5 inhibitor roscovitine. The inhibition of Cdk5 activity by roscovitine enhanced CaMKII autophosphorylation and activation in cultured neurons, and in an isolated postsynaptic‐density‐enriched fraction. These results suggest that Cdk5 activity suppresses CaMKII activation, and that the downregulation of Cdk5 activity after treatment withNMDA facilitates CaMKII activation, leading to the easier induction of long‐term potentiation. © 2006 Wiley‐Liss, Inc.
Differentiation of a human neuroblastoma into neuron‐like cells increases their susceptibility to transduction by herpesviral vectors
Authors: Gimenez‐Cassina Alfredo , Lim Filip , Diaz‐Nido Javier 
Published: June 2006

AbstractGene transfer is a powerful tool for functional gene analysis in human cells. In this respect, there is a need to develop experimental models that involve homogeneous cultures of human neuron‐like cells susceptible to gene transduction and that are easy to handle. Here we describe an optimized and reproducible procedure to differentiate human SH‐SY5Y neuroblastoma cells into a homogeneous population of neuron‐like cells. The fully differentiated cells are postmitotic and resemble primary cultured neurons in terms of their cytoskeletal polarity. Notably, differentiated SH‐SY5Y cells are far more susceptible to transduction by herpes simplex virus (HSV‐1)‐based vectors than proliferating SH‐SY5Y cells. This increase in transduction efficiency after neuronal differentiation may be due to the up‐regulation of cell surface receptors for herpesvirus entry. In summary, we propose that fully differentiated human neuron‐like cells obtained from the SH‐SY5Y neuroblastoma may constitute an excellent and versatile experimental tool for gene transfer and functional genomic studies with HSV‐1 vectors. © 2006 Wiley‐Liss, Inc.
Neurovascular and neuronal protection by E64d after focal cerebral ischemia in rats
Authors: Tsubokawa Tamiji , Yamaguchi‐Okada Mitsuo , Calvert John W. , Solaroglu Ihsan , Shimamura Norihito , Yata Kenichiro , Zhang John H. 
Published: June 2006

AbstractCalpains and cathepsins are two families of proteases that play an important role in ischemic cell death. In this study, we investigated the effect of E64d, a μ‐calpain and cathepsin B inhibitor, in the prevention of neuronal and endothelial apoptotic cell death after focal cerebral ischemia in rats. Rats underwent 2 hr of transient focal ischemia from middle cerebral artery occlusion (MCAO) and were sacrificed 24 hr later. E64d (5 mg/ kg intraperitoneally) was administered 30 min before MCAO. Assessment included neurological function, infarction volume, brain water content, blood–brain barrier permeability, histology, and immunohistochemistry. The E64d‐treated rats had significant brain protection against ischemic damage. We observed a reduction of infarction volume, brain edema, and improved neurological scores in E64d‐treated rats compared with the nontreated control. Furthermore, there was a remarkable reduction in both proteases and caspase‐3 activation and apoptotic changes in both neurons and endothelial cells in E64d‐treated rats. These results suggest that E64d protects the brain against ischemic/reperfusion injury by attenuating neuronal and endothelial apoptosis. © 2006 Wiley‐Liss, Inc.
Effect of valine on the efficiency and precision at S4 cleavage of the Notch‐1 transmembrane domain
Authors: Tanii Hisashi , Jiang Jingwei , Fukumori Akio , Tagami Shinji , Okazaki Yuji , Okochi Masayasu , Takeda Masatoshi 
Published: June 2006

AbstractPresenilin‐dependent intramembranous proteolysis mediates the dual cleavage of the Notch‐1 protein (S4 and S3) as well as the β amyloid precursor protein (βAPP) (γ40 and ϵ‐site). βAPP has a valine residue just before the γ40 (amyloid β [Aβ] numbering) site and after the ϵ‐site. Both γ40 and ϵ have multiple cleavage sites, and the varieties of γ40 cleavage are associated with Alzheimer's disease (AD). These lines of evidence suggest that valine plays a role in the intramembranous proteolysis. S4 cleavage in the middle of the Notch‐1 transmembrane domain (TMD) corresponds to the γ40 cleavage of βAPP. The cleavage site is in the center of four sequential alanine residues between Ala1731 and Ala1732, neither of which has a valine residue. To investigate the effects of valine on presenilin‐dependent intramembranous proteolysis, we replaced the transmembrane domain residue of Notch‐1 with valine and analyzed the efficiency and precision at S4 and S3. We observed that all valine‐mutated Notch‐1 proteins have a dominant cleavage site (S4) between Ala1731 and Ala1732 with some variations of cleavage precision, suggesting that valine is not indispensable for determining the cleavage site of the Notch‐1 transmembrane domain, but affects the efficiency and precision at S4 cleavage of the Notch‐1 transmembrane domain. © 2006 Wiley‐Liss, Inc.
Spatial and temporal daily rainfall regime in Catalonia (NE Spain) derived from four precipitation indices, years 1950–2000
Authors: Martínez M. D. , Lana X. , Burgueño A. , Serra C. 
Published: June 2006

AbstractAnnual rainfall amount, P, number of rainy days per year, N, average daily intensity in a year, I, and relevance, R, of the contribution of a rainfall class interval to the annual amount are used as pluviometric indices to deeply analyse the description of the complex behaviour of the daily rainfall regime of Catalonia (NE Spain). For this analysis, daily amounts of rainfall from 75 rain gauges for the period 1950–2000 have been considered. Indices N and I are analysed by distinguishing five percentiles (25th, 50th, 75th, 90th and 95th) of the daily rainfall amounts. Index R is evaluated taking into account <25%, 25–50%, 50–75%, 75–90%, ≥90% and ≥95% class intervals. All these indices are described by their mean annual values, standard deviations and consecutive temporal irregularities. Besides the complex orography of the country, effects of the influence of the Mediterranean regime and remoteness of the Iberian Peninsula to the Atlantic coast are detected in the diversity of spatial patterns of the indices. The influence of the Atlantic regime is also found at some places in the Pyrenees, especially those that faced north. All these features are described through a Principal Component Analysis (PCA), which is applied to average annual values of the pluviometric indices, and the subsequent clustering process. Additionally, time trends of the annual indices are analysed for a selected set of 39 rain gauges with an optimum recording continuity. Trends are derived from linear regression, and local statistical significances at the 95% confidence level are established using the Mann–Kendall test. Field significant trends are investigated by means of Monte Carlo simulations. It is worthy of mention that field significant trends have been detected in the number of rainy days for percentiles up to the 75th, all local trends being negative. Field significant trends are also detected in daily intensity, whatever the threshold level, with positive and negative local trends. The relevance index R depicts field significant trends for the first three class intervals, with a predominance of positive local trends in the first two, thus indicating an increasing contribution of light and moderate daily episodes to the annual amounts. Copyright © 2006 Royal Meteorological Society
Volume‐Resolved Nanostructure Survey of a Polymer Part by Means of SAXS Microtomography
Authors: Stribeck Norbert , Camarillo Armando Almendarez , Nöchel Ulrich , Schroer Christian , Kuhlmann Marion , Roth Stephan V. , Gehrke Rainer , Bayer Rüdiger K. 
Published: June 2006

AbstractSummary: Small‐angle X‐ray scattering (SAXS) microto‐ mography (micro‐CT) resolves structure variation in an anisotropic polyethylene (PE) gradient material with fiber symmetry. 4 900 reconstructed SAXS patterns describe the nanostructure as a function of volume element position in the scanned fiber cross‐section. Reconstruction errors were observed. Their first‐order effect was eliminated by transformation of the SAXS into a multidimensional chord distribution function (CDF). Its analysis shows oriented lamellae stacks in a shell layer and extended chains in the central core of the fiber. We document zones of uni‐ and bimodal structure, variation of long periods, stack heights, and lateral domain extension.Original SAXS patterns (pseudocolor and 3D plot) from different voxels obtained by micro‐CT reconstruction from measured SAXS projection patterns of a PE rod.imageOriginal SAXS patterns (pseudocolor and 3D plot) from different voxels obtained by micro‐CT reconstruction from measured SAXS projection patterns of a PE rod.
Apparent diffusion coefficients from high angular resolution diffusion imaging: Estimation and applications
Authors: Descoteaux Maxime , Angelino Elaine , Fitzgibbons Shaun , Deriche Rachid 
Published: June 2006

AbstractHigh angular resolution diffusion imaging has recently been of great interest in characterizing non‐Gaussian diffusion processes. One important goal is to obtain more accurate fits of the apparent diffusion processes in these non‐Gaussian regions, thus overcoming the limitations of classical diffusion tensor imaging. This paper presents an extensive study of high‐order models for apparent diffusion coefficient estimation and illustrates some of their applications. Using a meaningful modified spherical harmonics basis to capture the physical constraints of the problem, a new regularization algorithm is proposed. The new smoothing term is based on the Laplace–Beltrami operator and its closed form implementation is used in the fitting procedure. Next, the linear transformation between the coefficients of a spherical harmonic series of order ℓ and independent elements of a rank‐ℓ high‐order diffusion tensor is explicitly derived. This relation allows comparison of the state‐of‐the‐art anisotropy measures computed from spherical harmonics and tensor coefficients. Published results are reproduced accurately and it is also possible to recover voxels with isotropic, single fiber anisotropic, and multiple fiber anisotropic diffusion. Validation is performed on apparent diffusion coefficients from synthetic data, from a biological phantom, and from a human brain dataset. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Rapid cardiac‐output measurement with ungated spiral phase contrast
Authors: Park Jong B. , Hu Bob S. , Conolly Steven M. , Nayak Krishna S. , Nishimura Dwight G. 
Published: June 2006

AbstractAn ungated spiral phase‐contrast (USPC) method was used to measure cardiac output (CO) rapidly and conveniently. The USPC method, which was originally designed for small peripheral vessels, was modified to assess CO by measuring flow in the ascending aorta (AA). The modified USPC used a 12‐interleaf spiral trajectory to acquire full‐image data every 283 ms with 2‐mm spatial resolution. The total scan time was 5 s. For comparison, a triggered real‐time (TRT) method was used to indirectly calculate CO by measuring left‐ventricular (LV) volume. The USPC and TRT measurements from all normal volunteers agreed. In a patient with patent ductus arteriosus (PDA), high CO was measured with USPC, which agreed well with the invasive cardiac‐catheterized measurement. In normal volunteers, CO dropped about 20–30% with Valsalva maneuvering, and increased about 100% after exercise. Continuous 28‐s cycling between Valsalva maneuvering and free‐breathing showed that USPC can temporally resolve physiological CO changes. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.