bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel variable‐length sliding window blockwise least‐squares algorithm for on‐line estimation of time‐varying parameters
Authors: Jiang Jin , Zhang Youmin 
Published: June 2004

AbstractMotivated by the advances in computer technology and the fact that the batch/block least‐squares (LS) produces more accurate parameter estimates than its recursive counterparts, several important issues associated with the block LS have been re‐examined in the framework of on‐line identification of systems with abrupt/gradual change parameters in this paper. It is no surprise that the standard block LS performs unsatisfactorily in such a situation. To overcome this deficiency, a novel variable‐length sliding window‐based LS algorithm, known as variable‐length sliding window blockwise least squares, is developed. The algorithm consists of a change detection scheme and a data window with adjustable length. The window length adjustment is triggered by the change detection scheme. Whenever a change in system parameters is detected, the window is shortened to discount ‘old’ data and place more weight on the latest measurements. Several strategies for window length adjustment have been considered. The performance of the proposed algorithm has been evaluated through numerical studies. In comparison with the recursive least squares (RLS) with forgetting factors, superior results have been obtained consistently for the proposed algorithm. Robustness analysis of the algorithm to measurement noise have also been carried out. The significance of the work reported herein is that this algorithm offers a viable alternative to traditional RLS for on‐line parameter estimation by trading off the computational complexity of block LS for improved performance over RLS, because the computational complexity becomes less and less an issue with the rapid advance in computer technologies. Copyright © 2004 John Wiley & Sons, Ltd.
Internal Field Screening in Polymer Light‐Emitting Diodes
Authors: Brewer P. J. , Lane P. A. , deMello A. J. , Bradley D. D. C. , deMello J. C. 
Published: June 2004

AbstractWe use electromodulation spectroscopy and modeling studies to probe the electric‐field distribution in polyfluorene‐based polymer light‐emitting diodes containing poly(3,4‐ethylenedioxythiophene) poly(styrene sulfonate). The bulk internal field is shown to be zero under ordinary operating conditions, with trapped electrons close to the anode fully screening the bulk semiconductor from the external field. The effect has far‐reaching implications for the understanding and optimization of organic devices.
Dispersal ghosts in Oceania
Authors: Cann Rebecca L. , Lum J. Koji 
Published: June 2004

AbstractAnthropological genetics helps expand our understanding of human phenotypes in the Pacific, in part because of its focus on gene genealogies to infer past episodes of dispersal and to differentiate these events from adaptations due to long‐duration directional selection. Sewall Wright's 1949 seminal paper on population structure emphasized that there were two strong forces that exerted systematic and therefore determinant pressure on the gene pool: recurrent immigration and gene flow. These are important topics to all discussions of human dispersal in any region of the world. Furthermore, Wright listed five unique kinds of events that produced indeterminate or unpredictable changes that could lead to phenotypic and genotypic effects. In this category, he placed unique selective incidents, unique hybridization events, unique reductions in number, swamping by mass immigration, and mutational drive due to an allele always being favored since its origin or introduction. This discussion of human dispersal in the Pacific will touch on these topics, since they provide a second level of complexity in knowing who moved about a region of the world found already settled when rediscovered by colonial explorers during the 16–18th centuries. Am. J. Hum. Biol. 16:440–451, 2004. © 2004 Wiley‐Liss, Inc.
Mitochondrial DNA and Y chromosome diversity and the peopling of the Americas: Evolutionary and demographic evidence
Authors: Schurr Theodore G. , Sherry Stephen T. 
Published: June 2004

AbstractA number of important insights into the peopling of the New World have been gained through molecular genetic studies of Siberian and Native American populations. While there is no complete agreement on the interpretation of the mitochondrial DNA (mtDNA) and Y chromosome (NRY) data from these groups, several generalizations can be made. To begin with, the primary migration of ancestral Asians expanded from south‐central Siberia into the New World and gave rise to ancestral Amerindians. The initial migration seems to have occurred between 20,000–15,000 calendar years before present (cal BP), i.e., before the emergence of Clovis lithic sites (13,350–12,895 cal BP) in North America. Because an interior route through northern North America was unavailable for human passage until 12,550 cal BP, after the last glacial maximum (LGM), these ancestral groups must have used a coastal route to reach South America by 14,675 cal BP, the date of the Monte Verde site in southern Chile. The initial migration appears to have brought mtDNA haplogroups A‐D and NRY haplogroups P‐M45a and Q‐242/Q‐M3 to the New World, with these genetic lineages becoming widespread in the Americas. A second expansion that perhaps coincided with the opening of the ice‐free corridor probably brought mtDNA haplogroup X and NRY haplogroups P‐M45b, C‐M130, and R1a1‐M17 to North and Central America. Finally, populations that formerly inhabited Beringia expanded into northern North America after the LGM, and gave rise to Eskimo‐Aleuts and Na‐Dené Indians. Am. J. Hum. Biol. 16:420–439, 2004. © 2004 Wiley‐Liss, Inc.
Rural‐to‐urban migration in Latin America: An update and thoughts on the model
Authors: Dufour D.L. , Piperata B.A. 
Published: June 2004

AbstractUrbanization is an important demographic phenomenon, and in Latin America it transformed the settlement pattern from rural to predominantly urban in less than 50 years. Understanding the biological consequences of this change in settlement pattern is an important challenge for human biologists. One approach to understanding the effects of urban environments on human biology has been to study rural‐to‐urban migrants. In Latin America this research has shown that 1) the fertility of migrants tends to be intermediate between that of rural and urban populations, and 2) migrants tend to suffer higher rates of mortality and morbidity, at least initially, than long‐term urban residents. There is some indication that the actual physical conditions under which migrants live in urban areas—and these tend to be among the most impoverished—are more important variables than migrant status per se. Studying rural‐to‐urban migrants requires careful attention to a number of conceptual issues. One issue is the definition of rural and urban. These two types of settlements are no longer as distinct as they once were, and “urban” can mean very different things in different places. Another issue is the complexity of current migration patterns. The classic case of people moving from a distinctly rural setting to a distinctly urban one and staying there for the remainder of their lives is not the norm. Third, the urban environments of large cities are extraordinarily heterogeneous environments with enormous socioeconomic differentials in health. Hence, it matters where in the urban environment the migrants live. Am. J. Hum. Biol. 16:395–404, 2004. © 2004 Wiley‐Liss, Inc.
Fluctuating asymmetry predicts human reactive aggression
Authors: Benderlioglu Zeynep , Sciulli Paul W. , Nelson Randy J. 
Published: June 2004

AbstractFluctuating asymmetry (FA) represents non‐directional deviations from perfect symmetry in morphological characters. Prenatal stressors contribute to the imprecise expression of symmetrical phenotypes and display of agonistic behavior in children and adults. Because prenatal stress affects neurological function and overt behavior, and FA is often used as a marker for prenatal stress, we hypothesized that high FA would be associated with elevated levels of human reactive aggression. Data were collected from 100 males and females (average age = 20.1) on FA of 11 bilateral traits (second, third, fourth, and fifth digit length, palm height, wrist diameter, elbow width, ear height, ear width, foot breadth, and ankle circumference). Additional relationships were also investigated among FA, testosterone (T), and type of provocation to test a comprehensive aggression model. Experimental participants solicited donations for a fictitious charity organization via telephone and selected follow‐up letters after the calls. High FA and T values were independently associated with elevated reactive aggression (force of terminating the call) under low provocation in males, and under high provocation in females. In the absence of phenotypical markers, i.e., FA and T, sex differences in response to provocation disappeared and a “passive‐aggressive” response emerged. Both males and females selected hostile follow‐up letters, but showed low reactive aggression when terminating the call under high provocation. This pattern was reversed under low provocation. Taken together, these data suggest that individuals' phenotype and intensity of provocation are important determinants of individual and sex differences in aggression. Am. J. Hum. Biol. 16:458–469, 2004. © 2004 Wiley‐Liss, Inc.
Modeling of methyl isothiocyanate air concentrations associated with community illnesses following a metam‐sodium sprinkler application
Authors: O'Malley Michael , Barry Terrell , Verder‐Carlos Marylou , Rubin Andrew 
Published: June 2004

AbstractBackgroundA series of illnesses occurred in Earlimart, CA on November 13, 1999 following a metam‐sodium sprinkler application to a potato field on the southern edge of the town.MethodsCase information was obtained from direct interviews, from illness complaints filed with state or county agencies, or from illness reports filed by community physicians for 173 subjects. Air concentrations of the by‐product methyl isothiocyanate (MITC) during the episode were estimated based upon the Industrial Source Complex Short‐Term (ISC3) air dispersion model, estimates from prior metam‐sodium monitoring studies, and data from weather stations in two adjoining communities.ResultsWeather station data indicated that the November 13th incident corresponded with a temperature inversion at approximately 5:00 p.m. and a shift in the direction of prevailing wind from northwest to southeast. On the edge of Earlimart, 1‐hr time weighted average (TWA) MITC concentration estimates ranged from 0.5 to 1 ppm. Of the 173 subjects, 170 had MITC‐compatible symptoms, including eye or upper respiratory irritation (77.6%), non‐specific systemic symptoms (64.7%), and lower respiratory symptoms (20.0%). 78.2% were exposed within 0.5 miles of the northern edge of the treated field where average 1 hr MITC concentrations exceeded the 800 ppb ocular irritation threshold.ConclusionsISC3 modeling is a useful means of evaluating MITC concentrations for illness episodes when industrial hygiene assessment is not possible. Am. J. Ind. Med. 46:1–15, 2004. © 2004 Wiley‐Liss, Inc.
Blower Door‐Messungen: trotz Normen noch vieles unklar
Authors: Tanner Christoph , Mühlebach Hans 
Published: June 2004

AbstractEs ist unbestritten, daß eine möglichst luftdichte Gebäudehülle ein Qualitätsfaktor ist, der viele Vorteile bringt. Wird eine Luftdurchlässigkeits‐Messung durchgeführt, werden die Beurteilungen und Vergleiche von Luftwechselzahlen schwierig. Einerseits werden länderspezifisch unterschiedliche Kennwerte ermittelt, andererseits fehlen in den Normen meist detaillierte Ausführungsbestimmungen für die Gebäudepräparation. So besteht z. B. Spielraum beim Festlegen der Meßzone und es entstehen — je nach Abdichtungsort bei der Lüftungsanlage — große Unterschiede im Ergebnis. Wesentlichen Einfluß hat auch der Meßzeitpunkt: Eine Messung mit Leckagenortung in der Bauphase ist sinnvoll und erwünscht, gilt aber nicht als Abnahme, da das Gebäude durch die Fertigstellung noch verändert wird. Das hinterläßt Fragen über den Stellenwert von Luftdurchlässigkeits‐Messungen. Bei der Beurteilung von Niedrigenergiebauten kommt hinzu, daß die z. T. extrem niedrigen Grenzwerte nur aus energetischen Gründen gefordert werden, obwohl bekanntermaßen zwischen der Luftwechselzahl n50 und den energetisch relevanten Lüftungswärmeverlusten (durch Infiltration/Exfiltration) nur ein indirekter Zusammenhang besteht. Lösungsvorschläge für eine einheitliche Gebäudepräparierung und Datenauswertung werden z. Zt. diskutiert. Ziel ist es, für die wesentlichen Probleme der komplexen Meßmethode einfache, pragmatische Lösungen zu finden und die Möglichkeiten und Grenzen der Meßmethode besser bekannt zu machen.
Teil 3: Anwendung von Laborergebnissen in der Baupraxis, Ausführungsfehler
Authors: Sälzer Elmar , Eßer Georg , Sahl Markus , Kühn Herbert 
Published: June 2004

AbstractMit dem vorliegenden dritten Teil der dreiteiligen Serie „Schallschutz mit Hohlraumböden”︁ wird der Übergang von der Untersuchung und Erforschung der schalltechnischen Parameter von Hohlräumböden im Labor zur Baupraxis ermöglicht. Während in Teil 1 [1] über die geschichtliche Entwicklung der Hohlraumböden seit Beginn der 1980er sowie über die wesentlichen Parameter der Luftschalldämmung — nämlich die Normflankenpegeldifferenz (Luftschalldämmung bei horizontaler Übertragung, Schallängsdämmung) und die Schalldämmung von Massivdecken mit Hohlräumböden im vertikalen Durchgang berichtet wurde, sind in Teil 2 der Aufsatzreihe [2] die Parameter der Trittschalldämmung — nämlich die bewertete Trittschallminderung (Trittschallverbesserung) und der bewertete Norm‐Flankentrittschallpegel (bewerteter Normtrittschallpegel bei horizontaler Übertragung) dargestellt. Nachfolgend werden Vorschläge unterbreitet, wie in der Planung der am Bau erforderliche Schallschutz — entweder durch bauaufsichtliche Mindestanforderungen oder durch zivilrechtliche Vereinbarungen zwischen Nutzer und Investor — eingehalten werden kann, soweit dies die Hohlraumböden betrifft.
Monitoring and control of an anaerobic upflow fixed‐bed reactor for high‐loading‐rate operation and rejection of disturbances
Authors: Liu Jing , Olsson Gustaf , Mattiasson Bo 
Published: June 2004

AbstractA new control strategy has been introduced for operating anaerobic digestion processes efficiently at high load. The control system includes a cascade controller embedded into a rule‐based supervisory system based on extremum‐seeking control. Three process parameters, considered to be the most realistic variables for monitoring of the bioprocess, were selected (pH, biogas production rate, and the difference between the actual biogas flow and its setpoint). The control system examines these variables and varies the organic load by manipulating the influent flow. Good control performance was achieved during the start‐up, during steady‐state running operations, and during rejection of disturbances. The main advantages of this control approach can be attributed to its ability to adjust control parameters automatically, both for high‐load operation and for rejection of disturbances. Furthermore, the influent flow can be tuned automatically according to variations in organic matter in the feed without the characteristics of the influent being considered. © 2004 Wiley Periodicals, Inc.
High‐activity biocatalysts in organic media: solid‐state buffers as the immobilisation matrix for protein‐coated microcrystals
Authors: Kreiner Michaela , Parker Marie Claire 
Published: June 2004

AbstractRecently, we reported a new high‐activity biocatalyst for use in organic media termed protein‐coated microcrystals (PCMC) (Kreiner et al. [2001] Chem Commun 12:1096–1097). These novel particles consist of water‐soluble micron‐sized crystalline particles coated with the given biocatalyst(s) and are prepared in a one‐step rapid dehydration process. In this study we extended the choice of immobilisation matrix from a simple inorganic salt, K2SO4, to other compounds, both inorganic and zwitterionic, that act as solid‐state buffers for biocatalysis in organic media. The catalytic activity of serine proteases subtilisin Carlsberg (SC) and α‐chymotrypsin (CT) were significantly increased when coated onto the surface of solid‐state buffers, as measured in acetonitrile/1wt% H2O. SC‐PCMC with both organic and inorganic buffer carriers (Na‐AMPSO, Na2CO3, and NaHCO3) showed a 3‐fold greater activity than that observed when using the unbuffered system (PCMC‐SC/K2SO4). In comparison with freeze‐dried preparations, this represents an ∼3,000‐fold increase in catalytic activity. Importantly, there is no improvement in catalytic activity upon external addition of any of the solid‐state buffers to the reaction mixture. When acting in a solid‐state buffer capacity, good buffering capacity was observed with SC‐PCMC (3 wt% protein loading) prepared from a 1:1 mixture of AMPSO and AMPSO‐Na. Alternatively, increasing the amount of solid‐state buffer in the system allows improvement of the buffering. This can be achieved either by decreasing the protein loading of the SC/Na‐AMPSO‐PCMC or by addition of further external solid‐state buffer to the reaction mixture. The catalytic activity of lipase‐PCMC prepared from solid‐state buffers was found less responsive to immobilisation. © 2004 Wiley Periodicals, Inc.
Molecular stool screening for colorectal cancer
Authors: Mak T , Lalloo F , Evans D G R , Hill J 
Published: June 2004

Abstract

Background
Mass screening for colorectal cancer reduces mortality and, with recent advances in molecular genetics, molecular stool-based tests have produced promising results. This article reviews this innovation and discusses its clinical significance.

Methods
Medline searches were used to identify recent key articles relating to stool-based testing. Further articles were obtained by manual scanning of the reference lists of identified papers.

Results
Current screening methods are based on endoscopic, radiological and stool-based testing. Recent recognition of the adenoma–carcinoma sequence and pathophysiological studies of colonic epithelium have enabled tumour markers to be used in the screening setting. Non-invasive molecular stool testing has now been shown to have a high sensitivity and specificity.

Conclusion
Recent studies on molecular stool-based testing have shown higher sensitivity and specificity than earlier studies, but larger clinical trials are required. Laboratory methods are still undergoing research, with the aim of improving sensitivity to allow large-scale testing.
Letter 1: Safety lessons taken from the airlines (Br J Surg 2004; 91: 393–394)
Authors: Huang A 
Published: June 2004

Abstract
The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses can be sent electronically via the BJS website (www.bjs.co.uk) or by post. All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length. Letters submitted by post should be typed on A4-sized paper in double spacing and should be accompanied by a disk.
Vom Silberspiegel zum kratzfesten Autolack: Optimierte Oberflächen
Authors: Fröba Michael , Scheld Wilfried , Gath Carina , Hoffmann Frank 
Published: June 2004

AbstractIm Rahmen einer anorganisch‐chemischen Experimentalvorlesung werden verschiedene Verfahren vorgestellt, um besondere Oberflächeneigenschaften, wie Reflektivität, Korrosionsbeständigkeit, Selbstreinigung oder Kratzfestigkeit, gezielt auf chemischem Weg zu erhalten.
Architektur einer Lichtantenne
Authors: Harrer Roswitha 
Published: June 2004

AbstractMembranproteine sind „harte Nüsse”︁, wenn man sie kristallisieren und so ihre Struktur bestimmen will. Jüngstes Beispiel ist der pflanzliche Lichtsammelkomplex des Spinats, von dem erst heute, 10 Jahre nach einer ersten Kristallstruktur, eine hochauflösende Struktur vorgestellt werden kann. Diese besticht durch ihre faszinierende Architektur von Protein, Pigmenten und Lipid und gibt eine Vorstellung davon, wie Lichtenergie innerhalb des Moleküls verteilt wird.
Damit der Lack dran bleibt
Authors: Borchard‐Tuch Claudia 
Published: June 2004

AbstractDie Automobilindustrie stellt höchste Ansprüche an den Lack: Autos werden für einen weltweiten Markt produziert und müssen unterschiedlichsten klimatischen Bedingungen standhalten können. Erst das Zusammenspiel von mehreren maßgeschneiderten Schichten erfüllt die vielen Anforderungen.
Naturwissenschaftliche Museen und „Science Center”︁ im Netz — Appetithäppchen für Besuche?
Authors: Hildebrandt Henry 
Published: June 2004

AbstractDie Vielfalt der naturwissenschaftlich orientierten Museen in Deutschland ist kaum überschaubar. Die recht unterschiedlichen Selbstdarstellungen im Netz bieten methodisch interessante Möglichkeiten, Besuche vor Ort vorzubereiten. Eigene Wege könnten so eigene Interessen wecken — und nicht vorgedachte Pfade weiter austreten.
Study on the degeneration of quadrilateral element to triangular element
Authors: Li L.‐X. , Han X.‐P. , Xu S.‐Q. 
Published: June 2004

AbstractIn this paper, the problems involved in the process of degeneration of quadrilateral element into triangular element are thoroughly analysed. The contents include the formulation of the geometry mapping induced by collapsing one side of the quadrilateral element and the construction of the shape functions. The study focuses first on a 4‐node bilinear quadrilateral (Q4) element to 3‐node constant strain triangular (CST) element, and then on a 8‐node serendipity (Q8) element to 6‐node triangular element (T6). In the analysis, the quadrilateral element and degenerate triangular element are assumed to be enclosed by straight edges. The theoretical results show that there is another better approach to realize the degeneration, and that even for conventional approach of degeneration we can give more reasonable explanation to the unclear problems like the CST property in degenerate CST element and the necessity of the additional terms in degenerate T6 element. Copyright © 2004 John Wiley & Sons, Ltd.
PID congestion control in ATM with propagation delay
Authors: Kubo Seiji , Ushio Toshimitsu , Murata Masayuki , Ohsaki Hiroyuki 
Published: June 2004

AbstractRecently there have been many methods for rate control methods as applications of control theory. This paper considers congestion control in an ER system of ABR class in ATM as an example, and proposes a PID‐type control rule under the existence of propagation delay. In the ATM switch, we predict the buffer level after time which equals the propagation delay elapsed. Based on the difference between the predicted and target values, a QoS value is calculated. It is stored in the ER field of an RM cell, and sent to each source. The connection sets the transfer rate corresponding to the extent of satisfaction and the QoS service class. We show conditions for the control parameters in order to stabilize the buffer level. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(12): 90–99, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10071