bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter and state estimation in nonlinear stochastic continuous‐time dynamic models with unknown disturbance intensity
Authors: Varziri M. S. , McAuley K. B. , McLellan P. J. 
Published: September 2008

AbstractApproximate Maximum Likelihood Estimation (AMLE) is an algorithm for estimating the states and parameters of models described by stochastic differential equations (SDEs). In previous work (Varziri et al., Ind. Eng. Chem. Res.,47(2), 380‐393, (2008); Varziri et al., Comp. Chem. Eng., in press), AMLE was developed for SDE systems in which process‐disturbance intensities and measurement‐noise variances were assumed to be known. In the current article, a new formulation of the AMLE objective function is proposed for the case in which measurement‐noise variance is available but the process‐disturbance intensity is not known a priori. The revised formulation provides estimates of the model parameters and disturbance intensities, as demonstrated using a nonlinear CSTR simulation study. Parameter confidence intervals are computed using theoretical linearization‐based expressions. The proposed method compares favourably with a Kalman‐filter‐based maximum likelihood method. The resulting parameter estimates and information about model mismatch will be useful to chemical engineers who use fundamental models for process monitoring and control.
Extremum‐seeking control of retention for a microparticulate system
Authors: Favache Audrey , Dochain Denis , Perrier Michel , Guay Martin 
Published: September 2008

AbstractThe operation of a paper machine relies on the close monitoring and control of several integrated units to ensure a high quality paper with the required specifications. In this paper, the retention control system in the wet‐end of a paper machine is considered. The control objective is to maximize the retention of fines and fibres in the paper sheet to prevent the accumulation of micro particles in the water system. We present an adaptive extremum‐seeking scheme for the optimization and control of retention in the wet‐end of a paper machine. An adaptive learning technique is introduced to construct an algorithm that drives the system to the optimal retention value. Lyapunov's stability theory is used in the design of the extremum‐seeking controller structure and the development of the parameter learning laws. The performance of the technique is illustrated via simulations based on a first‐principles dynamic model developed previously for a micro‐particulate system.
Papillary thyroid carcinoma: Evidence for intracytoplasmic formation of precursor substance for calcification and its release from well‐preserved neoplastic cells
Authors: Das Dilip K. , Sheikh Zaffar A. , George Sara S. , Al‐Baquer Tahani , Francis Issam M. 
Published: October 2008

AbstractPsammoma bodies (PBs) are believed to represent a process of dystrophic calcification over nonviable and dying tissues. Light microscopic and ultrastructural observations suggest that PB formation follows the intracellular assembly of precursor substances and their calcification leading to death of tumor cells and their release. It may also be the result of local secretion of precursor substances like collagen by tumor cells into extracellular space and their calcification. In an earlier reported study, we demonstrated the extracellular localization of various precursor forms of PBs and of irregular calcification in fine‐needle aspiration (FNA) smears of papillary thyroid carcinoma (PTC). In this report, we describe a PTC case with intracellular formation precursor substances for calcification and their release from the well‐preserved neoplastic cells before undergoing calcification. Ultrasound‐guided FNA smears from a small nodule in the left lobe of thyroid in a 40‐year‐old woman revealed a PTC with numerous intracytoplasmic targetoid bodies, which were magenta colored in MGG stain. On their release from the neoplastic cells, these targetoid precursor bodies were found to be forming pools of matrix material, some of which showed evidence of calcification. The cytologic findings were confirmed by histopathology of the tumor in the thyroidectomy specimen. For the first time, we demonstrate through cytomorpholgy the intracytoplasmic formation of targetoid bodies as precursor substances for calcification and their release from well‐preserved cells in PTC. We suggest that the calcification in PTC may not necessarily be taking place over nonviable and dying cells. Diagn. Cytopathol. 2008;36:809–812. © 2008 Wiley‐Liss, Inc.
Cytomorphological diagnosis of malignant eccrine tumors: Report of two cases
Authors: Gangane Nitin , Joshi Deepti , Sharma S. M. 
Published: October 2008

AbstractThough FNAC has been successfully used in diagnosing various neoplastic and nonneoplastic cutaneous lesions, there is a paucity of case reports describing the cytomorphological features of adnexal tumors. We hereby describe the cytological features of two histologically confirmed cases of malignant eccrine tumors. Case number 1 presented with an ulcerated infraclavicular swelling whereas case number 2 presented with a cystic swelling over left foot. FNA and histological examination of the resected specimens was performed using standard techniques. A cytological diagnosis of low grade papillary adenocarcinoma arising from skin adnexal structures was given in case number 1. Aspirate from case number 2 was reported as positive for malignant cells, and histological examination was advised. Histological examination revealed the presence of malignant eccrine acrospiroma in case number 1 and papillary digital adenocarcinoma in case number 2. Careful cytological examination displayed the characteristic of two cell population seen in eccrine tumors in both the cases. Diagnosis of malignant eccrine tumors cannot be made with certainity on cytology alone, hence the need to document the cytological features of these entities is emphasized. Diagn. Cytopathol. 2008;36:801–804. © 2008 Wiley‐Liss, Inc.
Simultaneous cytological diagnosis of herpes simplex virus infection and primary lung cancer: Report of two cases
Authors: Maounis Nicoletta , Blana Aikaterini , Ellina Eleni , Chorti Maria , Lekkakou Agathi , Mermigkis Dimitri , Spanakis Nick , Emmanouilidou Aphrodite 
Published: October 2008

AbstractHerpes simplex is an uncommon cause of lower respiratory tract infection that requires prompt diagnosis and treatment to prevent late complications. We report two cases with simultaneous herpes simplex virus infection of the lower respiratory tract and lung carcinoma. Cytology of bronchial brushing and washing fluids and postbronchoscopic sputum established the diagnosis, which was further corroborated by real‐time polymerase chain reaction. Diagn. Cytopathol. 2008;36:818–822. © 2008 Wiley‐Liss, Inc.
Dichtkonstruktionen in der Landwirtschaft
Authors: Strathmann Brigitte , Westphal‐Kay Brigitte 
Published: October 2008

AbstractDer Artikel stellt dar, welche bauaufsichtlichen Verwendbarkeitsnachweise für Bauprodukte und Bauarten für Anlagen zum Lagern und Abfüllen von Jauche, Gülle und Silagesickersäften (JGS‐Anlagen) erforderlich sind. Hierbei wird auch der Zusammenhang zwischen den bauaufsichtlichen Verwendbarkeitsnachweisen für diese Bauprodukte und Bauarten sowie den Anforderungen gemäß § 19 g Wasserhaushaltsgesetz (WHG) beschrieben.Des Weiteren wird auf die Anforderungen eingegangen, die im Rahmen der Erteilung allgemeiner bauaufsichtlicher Zulassungen für Bauprodukte und Bauarten für JGS‐Anlagen – insbesondere von mit Dichtungsbahnen ausgekleideten Erdbecken zur Lagerung von JGS – zu erbringen sind. Das DIBt erteilt schon seit längerem allgemeine bauaufsichtliche Zulassungen für Bauprodukte und Bauarten für Anlagen zum Lagern, Abfüllen und Umschlagen wassergefährdender Stoffe. Jauche, Gülle und Silagesickersäfte nehmen aber im Rahmen der wassergefährdenden Stoffe eine Sonderstellung ein, die in diesem Artikel erläutert wird. Ferner soll der Beitrag eine Hilfestellung zur Suche von technischen Regeln geben, die für Bauprodukte und Bauarten für JGS‐Anlagen gelten.
Regioselective Acylation of Nucleosides Catalyzed by Candida Antarctica Lipase B: Enzyme Substrate Recognition
Authors: Li Ning , Zong Min‐Hua , Ma Ding 
Published: October 2008

AbstractThe substrate recognition of Candida antarctica lipase B (CAL‐B) in the acylation of nucleosides was revealed through rational substrate engineering for the first time. CAL‐B displayed lower activities and excellent 5′‐regioselectivities (94 to >99 %) in the acylation of ribonucleosides 1f–1j as compared to those in the acylation of 2′‐deoxynucleosides 1a–1e. The excellent regioselectivities might be attributed to the favorable steric hindrance of the 2′‐hydroxy group present in ribonucleosides 1f–1j, which destabilizes the conformation of the 3′‐acylation transition state in the acylation of 1f–1j and thus reduces the amount of the minor regioisomer. The study of the acyl chain‐length specificity showed that CAL‐B was more specific toward short‐chain fatty acid vinyl esters, especially vinyl butyrate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Preparation of the First Bench‐Stable Phenyl Selenolate: an Interesting “On Water” Nucleophilic Reagent
Authors: Santi Claudio , Santoro Stefano , Battistelli Benedetta , Testaferri Lorenzo , Tiecco Marcello 
Published: October 2008

AbstractIn this communication we report the synthesis and the characterization of the first solid and air‐stable selenolates, starting from commercially available phenylselenenyl halides and elemental zinc. These reagents were efficiently employed in the ring opening of epoxides as well as in other nucleophilic substitution and addition reactions showing an unexpected rate acceleration in water suspension at room temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
EEG alpha oscillations in the preparation for global and local processing predict behavioral performance
Authors: Volberg Gregor , Kliegl Katrin , Hanslmayr Simon , Greenlee Mark W. 
Published: October 2008

AbstractVisual attention can be directed either to the global features of a display or to the local elements that make up the display. We investigated whether oscillatory brain responses to globally or locally directed cue stimuli predict behavioral performance in subsequent target processing. Induced alpha band (8–12 Hz) amplitudes in the pre‐stimulus interval were measured separately for the global and the local level, where individual trials were assigned to one of three groups according to the response speed towards incongruent stimuli. Fast responses to local features were associated with high alpha amplitudes in the right centro‐parietal cortex, whereas fast responses to global forms were associated with high alpha in left centro‐parietal cortex. For trials with slower responses, the pattern of hemispheric differences was diminished or even reversed. It is interpreted that the left and the right parietal cortex exert top–down control over hierarchical processing by inhibiting stimulus representations in one hemisphere. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Analyzing brain networks with PCA and conditional Granger causality
Authors: Zhou Zhenyu , Chen Yonghong , Ding Mingzhou , Wright Paul , Lu Zuhong , Liu Yijun 
Published: October 2008

AbstractIdentifying directional influences in anatomical and functional circuits presents one of the greatest challenges for understanding neural computations in the brain. Granger causality mapping (GCM) derived from vector autoregressive models of data has been employed for this purpose, revealing complex temporal and spatial dynamics underlying cognitive processes. However, the traditional GCM methods are computationally expensive, as signals from thousands of voxels within selected regions of interest (ROIs) are individually processed, and being based on pairwise Granger causality, they lack the ability to distinguish direct from indirect connectivity among brain regions. In this work a new algorithm called PCA based conditional GCM is proposed to overcome these problems. The algorithm implements the following two procedures: (i) dimensionality reduction in ROIs of interest with principle component analysis (PCA), and (ii) estimation of the direct causal influences in local brain networks, using conditional Granger causality. Our results show that the proposed method achieves greater accuracy in detecting network connectivity than the commonly used pairwise Granger causality method. Furthermore, the use of PCA components in conjunction with conditional GCM greatly reduces the computational cost relative to the use of individual voxel time series. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Hierarchical functional modularity in the resting‐state human brain
Authors: Ferrarini Luca , Veer Ilya M. , Baerends Evelinda , van Tol Marie‐José , Renken Remco J. , van der Wee Nic J.A. , Veltman Dirk. J. , Aleman André , Zitman Frans G. , Penninx Brenda W.J.H. , van Buchem Mark A. , Reiber Johan H.C. , Rombouts Serge A.R.B. , Milles Julien 
Published: October 2008

AbstractFunctional magnetic resonance imaging (fMRI) studies have shown that anatomically distinct brain regions are functionally connected during the resting state. Basic topological properties in the brain functional connectivity (BFC) map have highlighted the BFC's small‐world topology. Modularity, a more advanced topological property, has been hypothesized to be evolutionary advantageous, contributing to adaptive aspects of anatomical and functional brain connectivity. However, current definitions of modularity for complex networks focus on nonoverlapping clusters, and are seriously limited by disregarding inclusive relationships. Therefore, BFC's modularity has been mainly qualitatively investigated. Here, we introduce a new definition of modularity, based on a recently improved clustering measurement, which overcomes limitations of previous definitions, and apply it to the study of BFC in resting state fMRI of 53 healthy subjects. Results show hierarchical functional modularity in the brain. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Inhibition dominates in shaping spontaneous CA3 hippocampal network activities in vitro
Authors: Ho Ernest C.Y. , Zhang Liang , Skinner Frances K. 
Published: October 2008

AbstractWe have assessed the balance of excitation and inhibition in in vitro rodent hippocampal slices exhibiting spontaneous, basal sharp waves (bSPWs). A defining signature of a network exhibiting bSPWs is the rise and fall in local field activities with frequencies ranging from 0.5 to 4.5 Hz. This variation of extracellular local field activities manifests at the intracellular level as postsynaptic potentials (PSPs). In correspondence with the local field bSPWs, we consider “sparse” and “synchronous” parts of bSPWs at the intracellular level. We have used intracellular data of bSPW‐associated PSPs together with mathematical extraction techniques to quantify the mean and variance of synaptic conductances that a neuron experiences during bSPW episodes. We find that inhibitory conductances dominate in pyramidal cells and in a putative interneuron, and that inhibitory variances are much greater than excitatory ones during synchronous parts of bSPWs. Specifically, we find that there is at least a twofold increase in inhibitory conductance dominance from “sparse” to “synchronous” bSPW states and that this transition is associated with inhibitory fluctuations of greater than 10% of the change in mean inhibitory conductance. On the basis of our findings, we suggest that such inhibitory fluctuations during transition may be a physiological feature of systems expressing such population activities. In summary, our results provide a quantified basis for understanding the interaction of excitatory and inhibitory neuronal subpopulations in bSPW activities. © 2008 Wiley‐Liss, Inc.
Quantitative transcriptional neuroanatomy of the rat hippocampus: Evidence for wide‐ranging, pathway‐specific heterogeneity among three principal cell layers
Authors: Greene James G. , Borges Karin , Dingledine Raymond 
Published: October 2008

AbstractWe have used laser‐capture microdissection and microarray hybridization to characterize gene expression in the three principal neuron layers of rat hippocampus. Correlative and clustering analyses revealed all three layers to be easily differentiated from one another based on gene expression profile alone. A greater disparity in gene expression exists between dentate granule and pyramidal cell layers, reflecting phenotypic and ontological differences between those cell populations. Remarkably, the level of more than 45% of expressed transcripts was significantly different among the three neuron populations, with more than a third of those (>1,000 transcripts) being at least twofold different between layers. Even CA1 and CA3 pyramidal cell layers were dramatically different on a transcriptional level with a separate analysis indicating that nearly 20% of transcripts are differentially expressed between them. Only a small number of transcripts were specific for a given hippocampal cell layer, suggesting that functional differences are more likely secondary to wide‐ranging expression differences of modest magnitude rather than very large disparities in a few genes. Categorical analysis of transcript abundance revealed concerted differences in gene expression among the three cell layers referable to specific cellular pathways. For instance, transcripts encoding proteins involved in glucose metabolism are most highly expressed in the CA3 pyramidal layer, which may reflect an underlying greater metabolic rate of these neurons and partially explain their exquisite vulnerability to seizure‐induced damage. Conversely, transcripts related to MAP kinase signaling pathways and transcriptional regulator activity are prominent in the dentate granule cell layer, which could contribute to its resistance to damage following seizure activity by positioning these neurons to respond to external stimuli by altering transcription. Taken together, these data suggest that unique physiological characteristics of major cell layers, such as neuronal activity, neuronal plasticity, and vulnerability to neurodegeneration, are reflected in substantial transcriptional heterogeneity within the hippocampus. © 2008 Wiley‐Liss, Inc.
Influence of presence of tannic acid on removal of sodium dodecylbenzenesulphonate by O3 and advanced oxidation processes
Authors: Sánchez‐Polo M. , Méndez‐Díaz J.D. , Rivera‐Utrilla J. , Bautista‐Toledo M.I. , Ferro‐Garcia M.A. 
Published: October 2008

AbstractBACKGROUND: The objective of the present investigation was to determine the role of the tannic acid (TAN) component of organic matter dissolved in water, in the removal of sodium dodecylbenzenesulphonate (SDBS) by ozone and by O3/H2O2, O3/granular activated carbon (GAC) and O3/powdered activated carbon (PAC) advanced oxidation processes.RESULTS: Low doses of TAN (1 mg L−1) during SDBS ozonation cause (i) an increased ozone decomposition rate and (ii) an increased SDBS removal rate. The SDBS removal rate with ozone in the presence of TAN was reduced when HCO3− ions were added. A rise in TAN concentration increased the SDBS removal rate, with a linear relationship between added TAN and the removal rate. SDBS was removed more effectively by O3/GAC, O3/PAC and O3/H2O2 systems in the presence of TAN.CONCLUSIONS: Results obtained indicated two mechanisms involved in the generation of HO· radicals by the O3/TAN interaction: (i) direct generation of HO· radicals from the reaction between ozone and TAN, and (ii) increased generation of O2−· radicals in the medium, enhancing the transformation of ozone into HO· radicals by different radical reactions. In O3/GAC and O3/PAC systems, HO· radicals are mainly generated in the O3/TAN interaction, which is a homogeneous reaction with fast kinetics, whereas the O3/GAC and O3/PAC interactions are in a heterogeneous phase with much slower kinetics, and are therefore not competitive in the generation of HO· radicals. Copyright © 2008 Society of Chemical Industry
Mitochondrial DNA phylogeography of Caiman crocodilus in Mesoamerica and South America
Authors: Venegas‐Anaya Miryam , Crawford Andrew J. , Escobedo Galván Armando H. , Sanjur Oris I. , Densmore Llewellyn D. , Bermingham Eldredge 
Published: October 2008

AbstractThe Neotropical crocodylian species, Caiman crocodilus, is widely distributed through Mesoamerica, northern South America, and the Amazon basin. Four subspecies are recognized within C. crocodilus, suggesting some geographic variation in morphology. In this study, we utilized mitochondrial DNA (mtDNA) sequence data from 45 individuals of C. crocodilus throughout its range to infer its evolutionary history and population structure, as well as to evaluate genealogical support for subspecies and their geographic distributions. Our molecular phylogenetic results identified five mtDNA haplotype clades with a mean sequence divergence of 3.4%, indicating considerable evolutionary independence among phylogeographic lineages. Our results were also broadly consistent with current subspecific taxonomy, with some important additional findings. First, we found substantial genetic structuring within C. c. fuscus from southern Mesoamerica. Second, though we confirmed the existence of a widespread Amazonian clade, we also discovered a cryptic and divergent mtDNA lineage that was indistinguishable from C. c. crocodilus based on external morphology. Third, we confirm the status of C. c. chiapasius as a distinct evolutionary lineage, and provide evidence that C. c. fuscus may be moving northward and hybridizing with C. c. chiapasius in northern Mesoamerica. Finally, our results parallel previous phylogeographic studies of other organisms that have demonstrated significant genetic structure over shorter geographic distances in Mesoamerica compared with Amazonia. We support conservation efforts for all five independent lineages within C. crocodilus, and highlight the subspecies C. c. chiapasius as a unit of particular conservation concern. J. Exp. Zool. 309A:614–627, 2008. © 2008 Wiley‐Liss, Inc.
The less than sweet solution to Fiji's sugar industry problems
Authors: Mahadevan Renuka 
Published: October 2008

AbstractThe loss of EU sugar preferences at the end of 2007 has made the push for reform more urgent than ever in the African, Caribbean and Pacific (ACP) countries. Fiji as a case study is useful to understand the difficulties faced in being competitive in the global market without the sugar subsidy. Using farm level survey, it was found that on average, technical efficiency (TE) was only about 72%, and that farm size should be expanded to gain from returns to scale. Empirical investigation and discussion shows that low efficiency is caused by lack of land tenure, poor infrastructural support, inefficiency in sugar institutions and the inadequate adoption of best farm practices. It is evident that the tight vertical integration of the industry necessitates an integrated and holistic approach to policy implementation. Copyright © 2008 John Wiley & Sons, Ltd.
Putting leakage in its place: The significance of retained tourism revenue in the local context in Rural Uganda
Authors: Sandbrook Chris G. 
Published: October 2008

AbstractIt is often argued that leakage of tourism revenue results in minimal economic benefits for host communities, particularly in rural areas of developing countries. However, leakage studies often employ flawed methods, and rarely compare retained revenue with other sources of income to such areas, which can be limited. This paper estimates these values for gorilla tracking tourism at Bwindi Impenetrable National Park, Uganda. Leakage was over 75%, but retained revenue was nevertheless greater than all other sources of revenue to the area combined. It is therefore argued that tourism can be highly significant in the local context despite considerable leakage. Copyright © 2008 John Wiley & Sons, Ltd.