bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological and Endocrine Study of the Ovarian Interstitial Tissue of Viscacha (Lagostomus maximus maximus)
Authors: Gil Esteban , FORNERIS Myriam , Domínguez Susana , Penissi Alicia , Fogal Teresa , Piezzi Ramón S. , Scardapane Luis
Published: June 2007

The morphological and endocrine aspects of the ovarian interstitial tissue of adult female viscachas were investigated to establish the probable function and the biological significance of this compartment in this rodent. Pregnant and nonpregnant adult female viscachas were used. The histological characteristics, histochemical properties, and ultrastructural features of the interstitial tissue were studied. A morphometric study was carried out to measure the relative area of lipid droplets. The progesterone and androstenedione levels in ovarian tissue as well as in serum were determined by radioimmunoassay. In this species, the histological observations showed an abundant interstitial tissue that contained a large amount of lipids. The cholesterol and its esters were present in nonpregnant females and were scarce in pregnant animals. The most ultrastructural differences were observed at mid‐pregnancy. At this stage, the interstitial cells showed features that suggested higher steroidogenic activity. Furthermore, during mid‐pregnancy, the relative area of lipid droplets was smaller. Both progesterone and androstenedione levels in ovarian tissue and serum were higher during pregnancy. Our results suggest that the interstitial tissue may be storage of precursor substances for the steroidogenesis via. These precursors are probably used when the endocrine requirements are high, that is, during the pregnancy. Thus, this compartment may contribute to the normal gestation of Lagostomus. However, the relation between the interstitial tissue and the pregnancy is complex, and further studies are needed to clearly establish it. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.
Statistical Shape Analysis of Differences in the Shape of the Corpus Callosum Between Genders
Authors: Ozdemir Senem Turan , Ercan Ilker , Sevinc Ozdemir , Guney Ibrahim , Ocakoglu Gokhan , Aslan Elif , Barut Cagatay
Published: June 2007

Sexual dimorphic characteristics, which play an important role in human evolution studies and biological research, can be studied morphologically and metrically. Geometric morphometrics allows a better assessment of morphological characteristics. Statistical shape analysis has a long history in neuroanatomical and other research. The aim of this study was to identify shape differences of the corpus callosum between genders. Landmark coordinate data were collected from two‐dimensional magnetic resonance imaging scans of 93 homogeneously aged patients, 45 men and 48 women. These data were analyzed using Euclidean distance matrix analysis and thin plate spline analysis. The general shape variability of the corpus callosum of men was greater than that of women (men, 0.134; women, 0.097). We found no significant difference between sexes in the general shape of the corpus callosum, but we did find significant differences in the distances between some landmarks. Deformation of the corpus callosum between men to women was mainly detected in the posterior of the corpus callosum. These results serve as a reference for future studies on shape alterations of the corpus callosum associated with certain conditions. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis of New (N α‐Dipicolinoyl)‐bis‐L‐valyl‐L‐phenylalanyl Linear and Macrocyclic Bridged Peptides as Anti‐Inflammatory Agents
Authors: Amr Abd El‐Galil E. , Abo‐Ghalia Mohamed H. , Abdalah Mohamed M.
Published: June 2007

In continuation to our search for new chiral macrocyclic peptide‐based anti‐inflammatories, the suggestion, synthesis, structure elucidation of some Nα‐bis‐dipicolinoyl amino acids, linear, tetra and cyclic (penta and octa)‐bridged peptides 3–10, were realized herein. The newly synthesized compounds showed potent anti‐inflammatory activity with low toxicity (LD50) comparable to indomethacin and diclofenac as reference anti‐inflammatory drugs.
New 4‐[(1‐Benzyl‐1H‐indol‐3‐yl)carbonyl]‐3‐hydroxyfuran‐2(5H)‐ones, β‐Diketo Acid Analogs as HIV‐1 Integrase Inhibitors
Authors: Ferro Stefania , Barreca Maria Letizia , De Luca Laura , Rao Angela , Monforte Anna Maria , Debyser Zeger , Witvrouw Myriam , Chimirri Alba
Published: June 2007

In addition to our recent report on a series of rationally designed benzylindolyldiketo acids acting as potent HIV‐1 integrase strand transfer inhibitors, we disclose the results obtained with novel compounds chemically modified on the diketo acid moiety in order to investigate its influence on the biological activity and cytotoxicity. The activity of designed and synthesized 4‐[(1‐benzyl‐1H‐indol‐3‐yl)carbonyl]‐3‐hydroxyfuran‐2(5H)‐one derivatives lies in the micromolar range with regard to HIV IN enzymatic activity. The microwave‐assisted synthesis was employed in some steps of the chemical procedures.
Modelling the independent insurance agent's product evaluation strategy: An application of conjoint analysis
Authors: Kling Nathan D. , Browne Lorne , Robinson Earl J.
Published: June 2007

A major property‐casualty insurance company had streamlined underwriting procedures and hoped to design a new commercial insurance package which would appeal to its independent agents. They hoped to do this by improving service times, premium and/or commission, but making these improvements would require the agents to fill out a new underwriting form. The research used conjoint analysis to determine for management the optimum levels of each of the factors to be employed in the new programme and the possible negative impact of the new underwriting form. Also discussed are issues relating to the use of conjoint analysis; in particular, the handling of large factorial designs and the aggregation of individual results.
Non‐parametric estimation for renewal processes from event count data
Authors: Dattero Ronald
Published: June 2007

A procedure is developed for estimating the interevent time distribution of a stationary renewal process that uses only data in the form of counts (the number of events occurring in each of several adjacent disjoint intervals) that are predominantly zeros and ones. Some properties of the procedure are derived, and the procedure's performance is assessed via Monte Carlo simulation.
Testing for the stability of automatic stabilizers
Authors: Uri Noel D.
Published: June 2007

This paper examines the question of the stability of automatic stabilizers in the United States. Using a test suggested by Brown, Durbin and Evans, the analysis suggests that the magnitude of automatic stabilization of economic activity afforded by personal tax receipts has remained virtually invariant over the period 1939–1985. The automatic stabilization effectiveness of transfer payments, however, has increased, especially since 1964. This is attributed to the implementaton of various Great Society Programs beginning in 1964.
Generalized linear models for the analysis of taguchi‐type experiments
Authors: Nelder J. A. , Lee Y.
Published: June 2007

Recent interest in Taguchi's methods have led to developments in joint analysis of the mean and dispersion from designed experiments. A commonly used method is the analysis of variance of the transformed data. However, a single transformation cannot necessarily produce the Normality, constancy of variance and linearity of systematic effects for the mean and dispersion models. We describe the use of generalized linear models for the analysis of such experiments and illustrate the methods with a data set.
Threshold dose—response model—RIP: 1911 to 2006
Authors: Calabrese Edward J.
Published: June 2007

This essay represents a serious but fictional obituary of a scientific concept called the Threshold Dose–Response Model, which has long dominated the fields of toxicology and the broader biomedical sciences. Recent evidence indicates that the Threshold Dose–Response Model has long outlived its utility to predict low‐dose effects. In fact, so poorly does this model predict low‐dose responses that the idea arose that it should receive a symbolic burial recounting its achievements and failings, hence this obituary. BioEssays 29:686–688, 2007. © 2007 Wiley Periodicals, Inc.
The echinoderm collagen fibril: a hero in the connective tissue research of the 1990s
Authors: Szulgit Greg
Published: June 2007

Collagen fibrils are some of the most‐abundant and important extracellular structures in our bodies, yet we are unsure of their shape and size. This is largely due to an inherent difficulty in isolating them from their surrounding tissues. Echinoderms have collagenous tissues that are similar to ours in many ways, yet they can be manipulated to easily relinquish their collagen fibrils, providing an excellent opportunity to study native fibrillar structure. In the early 1990s, they were found to defy the commonly accepted fibrillar model of the time in that they were much shorter, they were shaped like double‐ended spindles, and their centers exhibited a reversal in molecular polarity. Realization of these features helped to reform the questions that were being asked about vertebrate fibrils, shifting the focus toward shape and size. Since then, researchers working with both groups (echinoderms and vertebrates) have worked together to find the structure of native fibrils. This information will be fundamental in understanding what holds collagenous tissues together at the fibrillar level, and could have important implications for people with Ehlers‐Danlos syndrome. BioEssays 29:645–653, 2007. © 2007 Wiley Periodicals, Inc.
DNA microarrays in the clinic: how soon, how extensively?
Authors: Jordan Bertrand R.
Published: June 2007

Although DNA microarrays are now widely used in research settings, they have been slow to penetrate clinical practice in spite of their apparent advantages. This is due to the very different requirements for a clinical test in contrast to a research tool, and to a strict necessity for demonstrated clinical utility. There is a clear differentiation between two types of DNA array tests: “genomic” diagnostics, developed to ascertain the presence or absence of mutations, deletions or duplications, and for which clinical evidence is already established, and tests using expression profiling for prognosis or predictive purposes, in which case the clinical correlate must be proven. Most array diagnostics currently used belong, understandably, to the “genomic” variety. It is to be expected that future improvements in tailored technology, as well as a logical trend towards measuring an ever‐increasing number of parameters, will ensure an important diagnostic role for DNA arrays in the coming decade. BioEssays 29:699–705, 2007. © 2007 Wiley Periodicals, Inc.
Evolution of size and pattern in the social amoebas
Authors: Schaap Pauline
Published: June 2007

A fundamental goal of biology is to understand how novel phenotypes evolved through changes in existing genes. The Dictyostelia or social amoebas represent a simple form of multicellularity, where starving cells aggregate to build fruiting structures. This review summarizes efforts to provide a framework for investigating the genetic changes that generated novel morphologies in the Dictyostelia. The foundation is a recently constructed molecular phylogeny of the Dictyostelia, which was used to examine trends in the evolution of novel forms and in the divergence of genes that shape these forms. There is a major trend towards the formation of large unbranched fruiting bodies, which is correlated with the use of cyclic AMP (cAMP) as a secreted signal to coordinate cell aggregation. The role of cAMP in aggregation arose through co‐option of a pathway that originally acted to coordinate fruiting body formation. The genotypic changes that caused this innovation and the role of dynamic cAMP signaling in defining fruiting body size and pattern throughout social amoeba evolution are discussed. BioEssays 29:635–644, 2007. © 2007 Wiley Periodicals, Inc.
The two faces of short‐range evolutionary dynamics of regulatory modes in bacterial transcriptional regulatory networks
Authors: Balaji S. , Aravind L.
Published: June 2007

Studies on the conservation of the inferred transcriptional regulatory network of prokaryotes have suggested that specific transcription factors are less‐widely conserved in comparison to their target genes. This observation implied that, at large evolutionary distances, the turnover of specific transcription factors through loss and non‐orthologous displacement might be a major factor in the adaptive radiation of prokaryotes. However, the recent work of Hershberg and Margalit1 suggests that, at shorter phylogenetic scales, the evolutionary dynamics of the bacterial transcriptional regulatory network might exhibit distinct patterns. The authors find previously unnoticed relationships between the regulatory mode (activation or repression), the number of regulatory interactions and their conservation patterns in γ‐proteobacteria. These relationships might be shaped by the differences in the adaptive value and mode of operation of different regulatory interactions. BioEssays 29:625–629, 2007. © 2007 Wiley Periodicals, Inc.
Extracellular nucleic acids
Authors: Vlassov Valentin V. , Laktionov Pavel P. , Rykova Elena Y.
Published: June 2007

Extracellular nucleic acids are found in different biological fluids in the organism and in the environment: DNA is a ubiquitous component of the organic matter pool in the soil and in all marine and freshwater habitats. Data from recent studies strongly suggest that extracellular DNA and RNA play important biological roles in microbial communities and in higher organisms. DNA is an important component of bacterial biofilms and is involved in horizontal gene transfer. In recent years, the circulating extracellular nucleic acids were shown to be associated with some diseases. Attempts are being made to develop noninvasive methods of early tumor diagnostics based on analysis of circulating DNA and RNA. Recent observations demonstrated the possibility of nucleic acids exchange between eukaryotic cells and extracellular space suggesting their participation in so far unidentified biological processes. BioEssays 29:654–667, 2007. © 2007 Wiley Periodicals, Inc.
Granny, (don't) get your gun: competency issues in gun ownership by older adults
Authors: Greene Edith , Bornstein Brian H. , Dietrich Hannah
Published: June 2007

This article explores the possible risks associated with gun ownership by older adults. We summarize existing regulations on who may own firearms, especially with respect to age. We then present data on older gun owners and violence committed by older adults in general, followed by a discussion of gun violence perpetrated by gun owners whose functional and cognitive abilities have declined, perhaps as a result of dementia. For comparison purposes, we review regulations on driving among older adults, drawing parallels to gun ownership. The paper concludes with recommendations for ensuring the safety of older gun owners and others, balanced against citizens' right to bear arms, and with some directions for research. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of cardiac ischemic preconditioning on rat left ventricular gene expression profile
Authors: Canatan Halit
Published: June 2007

Ischemic preconditioning (IPC) is a phenomenon where heart is rendered more resistant to subsequent ischemia‐reperfusion (I‐R)‐induced injury by one or more brief episodes of I‐R. The mechanisms responsible for cardio‐protective effects of IPC are not well characterized. The objective of the study was to characterize gene expression profiles in the left ventricle of male Wistar rat hearts exposed to I‐R or IPC followed by I‐R. Group 1 included hearts that were only perfused for 30 min. Group 2 included hearts that underwent 30 min perfusion followed by 40 min I and 30 min R. Group 3 comprised 30 min perfused hearts that were subjected to IPC (5 min I + 10 min R + 5 min I + 10 min R) followed by I‐R. Total RNAs were isolated from left ventricular tissues. Codelink gene expression system (GE Healthcare) was used for cRNA target preparation, hybridization of microarrays (Rat UniSet 10 K CodeLink bioarrays, GE Healthcare) and detection. Microarrays were scanned with Affymetrix 428 Array scanner. Data analyses were carried out with GeneSifter microarray data analysis software. We determined a total of 140 transcripts (≥2‐fold change) whose expressions were changed (44 up‐regulated and 96 down‐regulated) accompanying to I‐R injury compared to perfused only hearts. Twenty‐three transcripts including Ryr3, Crk, Dio1, Npy1r, Ptpra, Cyp51 that were down‐regulated by I‐R injury, were up‐regulated by cardiac IPC. IPC down‐regulated the expression of several transcripts including Atf3 (activating transcription factor 3), carboxypeptidase A1 (Cpa1), Slc38a4, Blk which were up‐regulated by I‐R. In conclusion, evaluation of global gene expression profiling via microarray‐based technologies provides a molecular portrait of cardiac IPC of the left ventricular tissue of rat heart. Copyright © 2007 John Wiley & Sons, Ltd.
A Programmable Biomolecular Computing Machine with Bacterial Phenotype Output
Authors: Kossoy Elizaveta , Lavid Noa , Soreni‐Harari Michal , Shoham Yuval , Keinan Ehud
Published: June 2007

The main advantage of autonomous biomolecular computing devices over electronic computers is their ability to interact directly with biological systems. No interface is required since all components of molecular computers, including hardware, software, input, and output are molecules that interact in solution along a cascade of programmable chemical events. Here, we demonstrate for the first time that the output of a computation preduced by a molecular finite automaton can be a visible bacterial phenotype. Our 2‐symbol‐2‐state finite automaton utilized linear double‐stranded DNA inputs that were prepared by inserting a string of six base pair symbols into the lacZ gene on the pUC18 plasmid. The computation resulted in a circular plasmid that differed from the original pUC18 by either a 9 base pair (accepting state) or 11 base pair insert (unaccepting state) within the lacZ α region gene. Upon transformation and expression of the resultant plasmids in E. coli, the accepting state was represented by production of functional β‐galactosidase and formation of blue colonies on X‐gal medium. In contrast, the unaccepting state was represented by white colonies due to a shift in the open reading frame of lacZ.
Percutaneous left ventricular assist device complicated by a patent foramen ovale: Importance of identification and management
Authors: Loyalka Pranav , Idelchik Gary M. , Kar Biswajit
Published: June 2007

Recently, the TandemHeart® percutaneous left ventricular assist device (pVAD) has become available as a means to both resuscitate and support patients in cardiogenic shock pending myocardial recovery or definitive surgical or percutaneous intervention. Hypoxia during pVAD support may arise from multiple pulmonary etiologies, including pulmonary edema and mechanisms resulting in right‐to‐left shunting. We report two cases of patients supported by pVADs in who patent foramen ovale (PFO) present as right‐to‐left shunts following initiation of TandemHeart® support. A review of the mechanisms and hemodynamics resulting in PFO patency during pVAD support as well as suggestions for management are presented. © 2007 Wiley‐Liss, Inc.
Device fracture and severe tricuspid regurgitation after percutaneous closure of perimembranous ventricular septal defect: A case report
Authors: Mertens Luc , Meyns Bart , Gewillig Marc
Published: June 2007

We report a case in which fracture of an Amplatzer perimembranous ventricular septal defect (VSD) device occurred within 1 month after placement. This was associated with severe tricuspid regurgitation. Surgical removal of the device and repair of the tricuspid valve was performed with reasonable outcome. We propose a hypothesis on how this complication might have occurred and how it could be prevented. © 2007 Wiley‐Liss, Inc.
A new simplified method for calculating mean mitral pressure gradient
Authors: Cui Wei , Dai Ruping , Zhang Gejun
Published: June 2007

Background:

Mean mitral valve pressure gradient (MVPG) is one of the key measures of the severity of mitral stenosis. The method for calculating MVPG, however, is complex and time consuming. The purpose of this study is to establish a new simple method for calculating MVPG.

Methods:

Hemodynamic data were analyzed in 105 patients who underwent percutaneous balloon mitral valvuloplasty (PBMV). A new simplified method for calculating mitral pressure gradient was proposed, i.e., mean MVPG = MLAP – LVEDP/2, where MLAP is mean left atrial pressure, and LVEDP is left ventricular end‐diastolic pressure.

Results:

MVPGs derived from the standard and the new method were 13.28 ± 7.42 mm Hg and 13.50 ± 7.93 mm Hg, respectively, and there was no significant difference between the values of these two methods (P = 0.065). The MVPG derived from the new simplified method correlated closely with that calculated by the standard approach (r = 0.975, P < 0.001). Moreover, there was no significant difference between mitral valve areas (MVA) derived from the standard and the new approach either before or after PBMV in the 38 patients in whom cardiac output was measured.

Conclusion:

We conclude that mitral pressure gradient can be calculated reliably with our new simplified method. © 2007 Wiley‐Liss, Inc.
Paradoxical emboli through the patent foramen ovale as the suspected cause of myocardial and renal infarction in a 48‐year‐old woman
Authors: Garachemani Ali , Eshtehardi Parham , Meier Bernhard
Published: June 2007

We review the case of a 48‐year‐old woman who underwent elective percutaneous patent foramen ovale closure following successive renal and myocardial infarction with normal renal and coronary arteries, probably as a consequence of paradoxical emboli. © 2007 Wiley‐Liss, Inc.
Chemie in Wolken, Nebel und Niederschlag
Authors: Herrmann Hartmut , Jaeschke Wolfgang , Möller Detlev
Published: June 2007

Die wesentlichen Züge der Chemie in Wolken, Nebel und Niederschlag inklusive der Rolle der Eisphase werden dargestellt. Die physikalischen Systeme und die wichtigsten chemischen Umsetzungen werden beschrieben. Experimente im Feld und Laborexperimente werden dargestellt und wichtige Forschungsthemen benannt.
Organische Verbindungen und der Photosmog
Authors: Barnes Ian , Becker Karl‐Heinz , Wiesen Peter
Published: June 2007

In der Troposphäre werden infolge des stofflichen Eintrags aus natürlichen und anthropogenen Quellen mannigfaltige photochemische Reaktionen ausgelöst. Insbesondere wird die Bildung von Photooxidantien, verursacht durch die Emission reaktiver organischer Gase und Stickoxide als Vorkäufersubstanzen für Ozon, verändert. Einige grundlegende Reaktionsmechanismen für den Abbau verschiedener Gruppen organischer Verbindungen werden diskutiert. Der wichtigste Oxidationsmechanismus verläuft über OH‐Reaktionen in einer Radikalkette, die sich vor allem tagsüber in der belasteten Luft bei Sonneneinstrahlung ausbildet. Da über den Oxidationsmechanismus aromatischer Kohlenwasserstoffe die größten Wissenslücken bestehen, werden die dafür verantwortlichen bekannten und vorgeschlagenen Reaktionsmechanismen ausführlich erläutert. Schließlich wird das Problem der steigenden NO2‐Konzentrationen in urbaner Luft angesprochen.
Transportprozesse in der Atmosphäre
Authors: Schultz Martin , Stohl Andreas , Vogel Bernhard
Published: June 2007

Transportvorgänge in der Atmosphäre bestimmen, wie Spurenstoffe verteilt werden und wohin sich Schadstoffwolken ausbreiten. In diesem Aufsatz werden einige Grundlagen zu atmosphärischen Transportvorgängen erörtert und die Zusammenhänge zwischen Luftchemie und Winden aufgezeigt. Anhand einiger Beispiele aus der aktuellen Forschung wird verdeutlicht, welche Bedeutung Transportprozesse auf der lokalen bis interkontinentalen Skala für die Belastung der Luft mit Schadstoffen haben können.
POPs – schwer abbaubare Chemikalien
Authors: Lammel Gerhard , Zetsch Cornelius
Published: June 2007

POPs, persistent organic pollutants, sind in der Umwelt schwer abbaubare, gleichzeitig bioakkumulative und toxische Stoffe. Die meisten sind mittelflüchtig und lipophil. Sie werden in der Atmosphäre zu einem erheblichen Teil an Aerosolpartikel sorbiert und nach Ablagerung am Boden oder Deposition in den Ozean in die Atmosphäre zurück verflüchtigt und können so mehrere Emissions‐Transport‐Depositions‐Zyklen durchlaufen. Die Transport‐ und Verteilungsmuster und das Ferntransport‐Potenzial sind damit ganz anders als bei herkömmlichen Luftschadstoffen, deren Transport nach Ablagerung aus der Atmosphäre endet. Dass weite Strecken durch mehrere, jeweils kürzere Wege überwunden werden können, wird als Grashüpfer‐Effekt bezeichnet. Eine wichtige Hypothese der Umweltchemie besagt, dass die beobachtete Anreicherung von vielen persistenten und bioakkumulativen Schadstoffen in den Polargebieten, fernab der Anwendungsgebiete eine Konsequenz des Grashüpfer‐Effekts sei in Verbindung mit stärkerer Kondensation in kalten Gebieten. Die Lipophilie ist die Voraussetzung für die Bioakkumulation und beeinflusst die Verteilung der Stoffe über mehrere Umweltmedien. Weil es sich bei den POPs im Allgemeinen um teilhalogenierte Stoffe handelt, ist der atmosphärische Abbau zumeist langsamer als für andere Luftschadstoffe, aber schneller als in den anderen Umweltkompartimenten, in denen erst bei Verweildauern von Monaten von Persistenz gesprochen wird. Ferntransport‐Potenzial und Persistenz eines Stoffes sind wichtig für die Einschätzung der Gefährdung, die von ihm ausgeht. Sie sind das Ergebnis des Zusammenwirkens physikalisch‐chemischer Stoffeigenschaften mit den in Raum und Zeit variablen Umweltbedingungen. Sie variieren deswegen in Raum und Zeit.
Experimente in großen Simulationskammern
Authors: Brauers Theo , Wiesen Peter
Published: June 2007

Große Simulationskammern bieten die Möglichkeit, auch komplexe Systeme der atmosphärischen Chemie unter vorgegebenen und gut kontrollierten Bedingungen zu untersuchen. In großen Kammern kann bei niedrigen Konzentrationen gearbeitet werden, was die Übertragbarkeit auf die reale Atmosphäre verbessert. Darüber hinaus lassen sich feldtaugliche Instrumente an der Kammer einzusetzen. In den vergangen 30 Jahren wurden wichtige Erkenntnisse zu Spurengasen und Aerosolen in Simulationskammern gewonnen. Heute werden Simulationskammern immer wichtiger bei der Entwicklung neuer Verfahren zur Untersuchung atmosphärischer Spurenstoffe sowie für den direkten Vergleich verschiedener Messverfahren.
Die Atmosphäre als photochemischer Reaktor
Authors: Wahner Andreas , Moortgat Geert
Published: June 2007

Die Troposphäre ist ein sehr großer photochemischer Reaktor, der enorme Mengen Spurengase und Aerosole verarbeitet. Zukünftige Zunahmen der anthropogenen und natürlichen Emissionen und Aerosolbildung werden den Zustand der Troposphäre und das Klima weiter verändern. Dabei hat die “Selbstreinigungsfähigkeit” der Troposphäre eine entscheidende Bedeutung. Troposphärische Oxidation wird durch eine Reihe von Oxidationsmitteln, vor allem durch das Hydroxylradikal, OH, aber auch durch Ozon, O3, das Nitratradikal, NO3, eingeleitet. Reagieren OH‐Radikale mit Spurengasmoleküle werden sie nicht verbraucht, sondern in katalytischen Zyklen regeneriert, wobei die Konzentration der Stickoxide eine entscheidende Rolle spielt. Dieses, an einfachen Beispielen dargestellte, photochemische Reaktionssystem der Troposphäre ist generell zutreffend: nahezu alle Reaktionen von OH mit atmosphärischen Spurengasen (wie z. B. Methan, anthropogen oder biogen emittierten organischen Spurenstoffen) führen zu Kettenreaktionen, die OH‐Rradikale regenerieren. Es veranschaulicht, dass in einer NO enthaltenden Atmosphäre der Spurengasabbau unabänderlich mit der Produktion von O3 verbunden ist, die Selbstreinigungsfähigkeit und damit die Luftqualität und Klimawirkung der Troposphäre entscheidend von der troposphärischen Photochemie und den Emissionen beeinflusst wird.
Introduction of a Generally Applicable Method to Estimate Retrieval of Active Molecules for Similarity Searching using Fingerprints
Authors: Vogt Martin , Bajorath Jürgen
Published: June 2007

Fingerprints are bit string representations of molecular structure and properties and are among the most widely used computational tools for similarity searching and database screening. Various fingerprint designs are available and their search performance is in general strongly dependent on the compound classes under study and the chemical characteristics of screening databases. Currently, it is not possible to predict the probability of identifying novel hits through fingerprint searching. However, for practical applications, such estimations would be very useful because one might be able, for example, to prioritize fingerprints and compound selection strategies or decide whether or not a similarity search campaign with subsequent experimental evaluation of candidate compounds would be promising at all. We have developed a method that makes it possible to predict the outcome of similarity search calculations using any type of keyed fingerprint. The methodology incorporates bit frequency distributions of reference molecules and the screening database into an information‐theoretic function and determines the principally possible recall of active compounds within selection sets of varying size. We calibrate the function on diverse compound classes and accurately predict compound recovery in retrospective virtual screening trials. Furthermore, we correctly predict fingerprint search performance on two experimental high‐throughput screening data sets (HTS). Our findings indicate that given a set of reference molecules, a fingerprint, and a screening database, we can readily estimate how likely it will be to retrieve active compounds, without knowledge about the distribution of potential hits in the database.
Parallel Delaunay triangulation for particle finite element methods
Authors: Fragakis Yannis , Oñate Eugenio
Published: June 2007

Delaunay triangulation is a geometric problem that is relatively difficult to parallelize. Parallel algorithms are usually characterized by considerable interprocessor communication or important serialized parts. In this paper, we propose a method that achieves high speed‐ups, but needs information regarding locally maximum element circumspheres prior to the beginning of the algorithm. Such information is directly available in iterative methods, like the particle finite element methods. The developed parallel Delaunay triangulation method, has minimum communication requirements, is quite simple and achieves high parallel efficiency. Copyright © 2007 John Wiley & Sons, Ltd.
Probing for electrical inclusions with complex spherical waves
Authors: Ide Takanori , Isozaki Hiroshi , Nakata Susumu , Siltanen Samuli , Uhlmann Gunther
Published: June 2007

Let a physical body Ω in ℝ2or ℝ3be given. Assume that the electric conductivity distribution inside Ω consists of conductive inclusions in a known smooth background. Further, assume that a subset Γ ⊂ ∂Ω is available for boundary measurements. It is proved using hyperbolic geometry that certain information about the location of the inclusions can be exactly recovered from static electric measurements on Γ. More precisely: given a ballBwith center outside the convex hull of Ω and satisfying (B̄ ∩ ∂Ω) ⊂ Γ, boundary measurements on Γ with explicitly given Dirichlet data are enough to determine whetherBintersects the inclusion. An approximate detection algorithm is introduced based on the theory. Numerical experiments in dimension two with simulated noisy data suggest that the algorithm finds the inclusion‐free domain near Γ and is robust against measurement noise. © 2007 Wiley Periodicals, Inc.
Roles of Drosophila Kruppel‐homolog 1 in neuronal morphogenesis
Authors: Shi Lei , Lin Suewei , Grinberg Yelena , Beck Yannick , Grozinger Christina M. , Robinson Gene E. , Lee Tzumin
Published: June 2007

The molecular mechanisms underlying remodeling of neural networks remain largely unknown. In Drosophila, widespread neural remodeling occurs during metamorphosis, and is regulated by ecdysone. Kruppel‐homolog 1 (Kr‐h1) is a zinc finger transcription factor known to play a role in orchestrating ecdysone‐regulated transcriptional pathways and, furthermore, implicated in governing axon morphogenesis. Interestingly, in honey bee workers, neural expression of the Apis mellifera homolog of Kr‐h1 is enhanced during their transition to foraging behavior when there is increased neurite outgrowth, branching, and synapse formation. Here, we assessed the role(s) of KR‐H1 in Drosophila neuronal remodeling and morphology. We characterized the effect of Kr‐h1 expression on neuronal morphology through Drosophila larval, pupal, and adult stages. Increased expression of Kr‐h1 led to reduced branching in individual neurons and gross morphological changes in the mushroom bodies (MBs), while knocking down Kr‐h1 did not produce any obvious changes in neural morphology. Drosophila Kr‐h1 is normally expressed when MB neurons do not undergo active morphogenesis, suggesting that it may play a role in inhibiting morphogenesis. Further, loss of endogenous KR‐H1 enhanced the neuronal morphogenesis that is otherwise delayed due to defective TGF‐β signaling. However, loss of KR‐H1 alone did not affect neuronal morphogenesis. In addition, Kr‐h1 expression remains strongly linked to ecdysone‐regulated pathways: Kr‐h1 expression is regulated by usp, which dimerizes to the ecdysone receptor, and Kr‐h1 expression is essential for proper patterning of the ecdysone receptor isoforms in the late larval central nervous system. Thus, although KR‐H1 has a potential for modulating neuronal morphogenesis, it appears physiologically involved in coordinating general ecdysone signaling. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
House dust mite allergen activates human eosinophilsviaformyl peptide receptor and formyl peptide receptor‐like 1
Authors: Svensson Lena , Redvall Elin , Björn Camilla , Karlsson Jennie , Bergin Ann‐Marie , Rabiet Marie‐Josèphe , Dahlgren Claes , Wennerås Christine
Published: June 2007

The objective was to evaluate which receptors house dust mite (HDM) and birch pollen extracts engage to activate human eosinophils. Chemotaxis and degranulation were studied in eosinophils pretreated with pertussis toxin and other antagonists of G protein‐coupled receptors,e.g.the formyl peptide receptor (FPR), CC chemokine receptor 3 (CCR3) and leukotriene receptor B4 (LTB4R). Inhibition of the FPR as well as desensitization of the receptor rendered eosinophils anergic to activation by the allergens. Blockade of CCR3 or LTB4R did not affect eosinophilic reactivity. It was determined by PCR that human eosinophils express the FPR family members FPR and FPR‐like 1 (FPRL1). HDM, unlike birch pollen, evoked calcium fluxes in HL‐60 cells transfected with FPR or FPRL1. Although both allergens gave rise to calcium transients in neutrophils, which also express FPR and FPRL1, only the HDM response was decreased by the FPR antagonist. Moreover, neutrophils migrated toward HDM but not to birch pollen. Eosinophils pretreated with inhibitors of MAPK p38, ERK1/2 or protein kinase C exhibited diminished responsiveness to the aeroallergens. This study indicates that FPR and FPRL1 mediate the activation of eosinophils by HDM, whereas birch pollen employs other pathways shared with FPR to activate human eosinophils.
A Reagentless Amperometric Immunosensor for Alpha‐Fetoprotein Based on Gold Nanoparticles/TiO2 Colloids/Prussian Blue Modified Platinum Electrode
Authors: Yuan Yanru , Yuan Ruo , Chai Yaqin , Zhuo Ying , Shi Yintao , He Xiulan , Miao Xiangmin
Published: June 2007

A novel reagentless amperometric immunosensor for the determination of alpha‐fetoprotein (AFP) was prepared by immobilizing TiO2 colloids on Prussian blue (PB) modified platinum electrode, which yielded a positively charged interface with strong adsorption to deposit gold nanoparticles for immobilization of alpha‐fetoprotein antibody (anti‐AFP). The factors influencing the performance of the proposed immunosensors were studied in detail. Under the optimized conditions, cyclic voltammograms determination of AFP showed a specific response in two concentration ranges from 3.0 to 30.0 ng/mL and from 30.0 to 300.0 ng/mL with a detection limit of 1.0 ng/mL at a signal‐to‐noise ratio of 3. The proposed immunosensor exhibited high selectivity, good reproducibility, long‐term stability (>2 months) and good repeatability.
Preparation, Characterization and Electrocatalytic Studies on Copper Complex Dye Film Modified Electrodes
Authors: Chen Shen‐Ming , Liu Jun‐Wei , Thangamuthu R.
Published: June 2007

Copper complex dye (C.I. Direct Blue 200) film modified electrodes have been prepared by multiple scan cyclic voltammetry. The effect of solution pH and nature of electrode material on film formation was investigated. The optimum pH for copper complex film formation on glassy carbon was found to be 1.5. The mechanism of film formation on ITO seems to be similar to that on GC surface but completely different mechanism followed with gold electrode. Cyclic voltammetric features of our modified electrodes are in consistent with a surface‐confined redox process. The voltammetric response of modified electrode was found to be depending on pH of the contacting solution. UV‐visible spectra show that the nature of copper complex dye is identical in both solution phase and after forming film on electrode. The electrocatalytic behavior of copper complex dye film modified electrode towards oxidation of dopamine, ascorbic acid and reduction of SO52− was investigated. The oxidation of dopamine and ascorbic acid occurred at less positive potential on film electrode compared to bare glassy carbon electrode. Feasibility of utilizing our modified electrode in analytical estimation of dopamine, ascorbic acid was also demonstrated.
Development of an Amperometric Immunosensor for the Quantification of Staphylococcus aureus Using Self‐Assembled Monolayer‐Modified Electrodes as Immobilization Platforms
Authors: Escamilla‐Gómez Vanessa , Campuzano Susana , Pedrero María , Pingarrón José M.
Published: June 2007

Amperometric immunosensors for the detection and quantification of S. aureus using MPA self‐assembled monolayer modified electrodes for the immobilization of the immunoreagents are reported. Two different immunosensor configurations were compared. A competitive mode, in which protein A‐bearing S. aureus cells and antiRbIgG labeled with horseradish peroxidase (HRP) compete for the binding sites of RbIgG immobilized onto the 3‐mercaptopropionic acid (MPA) modified electrode, was evaluated. Moreover, a sandwich configuration in which S. aureus cells were immobilized onto the MPA SAM, and RbIgG and antiRbIgG labeled with HRP were further linked to the electrode surface, was also tested. In both cases, TTF was used as the redox mediator of the HRP reaction with H2O2, and it was co‐immobilized onto the MPA‐modified gold electrode. After optimization of the working variables for both configurations, the analytical performance of the amperometric measurements carried out at 0.00 V (vs. Ag/AgCl) showed that the competitive immunosensor exhibited a lower limit of detection (1.6×105 S. aureus cells mL−1), as well as a better repeatability and reproducibility of the measurements.
Early Pragian conodont‐based correlations between the Barrandian area and the Spanish Central Pyrenees
Authors: Slavík Ladislav , Valenzuela‐Ríos José Ignacio , Hladil Jindřich , Carls Peter
Published: June 2007

Occurrences and distribution of extremely scarce eognathodontids do not facilitate reliable correlation across the European regions. The correlation of the traditional early Pragian of the Prague Synform (a part of the classical Barrandian area) and the Spanish Central Pyrenees (section Segre 1) is based on conodont taxa of the Icriodus steinachensis and the Pelekysgnathus serratus stocks. This correlation has the potential to be extended to other peri‐Gondwanan regions where this scarcity of eognathodontid faunas exists as well. Application of the morphotype subdivision in I. steinachensis enables approximation of the beginning of the Pragian in the Pyrenees. It is based on the entry of I. steinachensis beta morphotype; it enters together with early eognathodontid taxa in the Barrandian sections. These correlations show that routine application of certain zonal concepts can lead to misleading conclusions. Copyright © 2007 John Wiley & Sons, Ltd.
Risk factors of cognitive decline in residential care in Hungary
Authors: Vincze Gábor , Álmos Péter , Boda Krisztina , Döme Péter , Bódi Nikoletta , Szlávik Győző , Maglóczki Erzsébet , Pákáski Magdolna , Janka Zoltán , Kálmán János
Published: June 2007

Objective

The incidence of dementia is known to vary between nations due to population specific interactions of genetic and epigenetic risk factors. Since this type of data was missing from the Central‐Eastern part of Europe, especially from Hungary, an ongoing prospective multicentre study was initiated 3 years ago to determine the impact of some well‐known social and biological dementia risk factors and the prevalences and conversion rates of dementia and depression syndromes.

Methods

As part of this work, the effects of age, gender, education, smoking and alcohol consumption were investigated in residental homes‐based cohort of more than 2,100 elderly.

Results

Forty‐eight percent of the entire population showed clinical signs of cognitive decline. Eighteen percent, 22%, 16% and 10% were classified as mild cognitive impairment, mild, moderate and severe stages of cognitive decline, respectively. Considered individually, all the examined dementia risk factors were significantly related to the presence of the cognitive decline. Age, female gender and regular drinking increased the risk, while smoking, higher level of education and occasional or former history of alcohol consumption were protective factors. The male gender associated regular alcohol consumption represented the strongest risk, especially with low education levels. When the different severity subgroups were compared, similar risk tendencies have been observed, but the most robust effects were associated with the most severe stages.

Conclusions

The well‐known dementia risk and protective factors are confirmed in our study. Taking these variables into consideration, the Hungarian cohort is similar to other ethnic groups in Europe. Copyright © 2007 John Wiley & Sons, Ltd.
An evaluation of a specialist multiagency home support service for older people with dementia using qualitative methods
Authors: Rothera Ian , Jones Rob , Harwood Rowan , Avery Anthony J. , Fisher Kate , James Veronica , Shaw Ian , Waite Jonathan
Published: June 2007

Background

Standard home care support for people with dementia has been criticised in statutory inspection reports, and may lead to unnecessary crises, hospital or care home admissions.

Objective

To establish whether a specialist multiagency home care service for older people with dementia delivered better quality care than standard services, and how any improvements were achieved.

Design

Qualitative study, using semi‐structured interviews, focus groups and small group interviews.

Setting

Two demographically similar areas in Nottingham, one served by a specialist home care team, the other by standard services.

Participants

Twenty‐seven service users, 18 family carers, 17 home care workers, 20 health/social care professionals, across both services.

Results

The specialist service demonstrated greater flexibility and responsiveness to the particular needs and circumstances of service users and family carers, who were encouraged to participate in routine decision‐making and activities. By sharing responsibilities, the specialist service helped reduce carer stress and prevent crises. These outcomes depended on the configuration of the service, including multidisciplinary health and social services input, careworker autonomy and independence, continuous reassessment of clients' circumstances and preferences and the capacity to develop long‐term relationships, through careworker continuity. The standard service, which used a task‐orientated approach, lacked these characteristics.

Conclusions

This study provides evidence of the benefits of a specialist multiagency home support service over standard home care, in the opinion of service users, carers and careworkers, and defines the operational model that achieves this. Findings confirm best practice recommendations, based on models of dementia care which emphasise respect for ‘personhood’. Copyright © 2007 John Wiley & Sons, Ltd.
Contaminant transport in one‐dimensional single fractured media: semi‐analytical solution for three‐member decay chain with pulse and Heaviside input sources
Authors: Shih David Ching‐Fang
Published: June 2007

A semi‐analytical solution of the one‐dimensional transport for considering a three‐member decay chain in a single fracture with pulse and Heaviside input sources has been studied using the Laplace transform and its numerical inversion. The results reveal that breakthrough curves of dimensionless concentration for the decay chain of Np‐237, U‐233, and Th‐229 in the fracture can be well demonstrated in the temporal and spatial domains. The conditions with and without retardation effects are also compared. During the preliminary screening phase the solutions are suitable for performance assessment on radioactive waste disposal sites under a one‐dimensional single fracture condition. Copyright © 2007 John Wiley & Sons, Ltd.
A cellular automata model of surface water flow
Authors: Parsons Jay A. , Fonstad Mark A.
Published: June 2007

Previous cellular automata models of surface water flow have been constructed to reflect steady, gradually‐varied flow conditions. While these models are extremely important in showing the near‐equilibrium forms that result from the interactions of water and boundary material, highly dynamic forms and processes require models that represent unsteady flow conditions. In order to simulate unsteady flow in a cellular model of surface water flow, the conservation of mass and the Manning's equations are coupled with an algorithm to delay the movement of water from one pixel to the next until the correct timing is reached. This approach yields highly realistic flood wave hydrographs when compared with flood observations in the Walnut Gulch Experiment Watershed. Coupling this unsteady flow model with simple laws of sediment erosion, transport, and deposition should allow event‐based simulations of watershed and river channel geomorphologic change. Copyright © 2007 John Wiley & Sons, Ltd.