bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Affecting Daily Nest Survival of Burrowing Owls Within Black‐Tailed Prairie Dog Colonies
Authors: LANTZ SARAH J. , CONWAY COURTNEY J.
Published: January 2009

ABSTRACT Identifying environmental parameters that influence probability of nest predation is important for developing and implementing effective management strategies for species of conservation concern. We estimated daily nest survival for a migratory population of burrowing owls (Athene cunicularia) breeding in black‐tailed prairie dog (Cynomys ludovicianus) colonies in Wyoming, USA. We compared estimates based on 3 common approaches: apparent nesting success, Mayfield estimates, and a model‐based logistic‐exposure approach. We also examined whether 8 intrinsic and extrinsic factors affected daily nest survival in burrowing owls. Positive biases in apparent nest survival were low (3–6%), probably because prior knowledge of nest locations and colonial behavior among nesting pairs facilitated discovery of most nests early in the nesting cycle. Daily nest survival increased as the breeding season progressed, was negatively correlated with ambient temperature, was positively correlated with nest‐burrow tunnel length, and decreased as the nesting cycle progressed. Environmental features were similar between failed and successful nests based on 95% confidence intervals, but the seasonal midpoint was earlier for failed nests (31 May) compared to successful nests (15 Jun). The large annual variation in nest survival (a 15.3% increase between 2003 and 2004) accentuates the importance of multiyear studies when estimating reproductive parameters and when examining the factors that affect those parameters. Failure to locate and monitor nests throughout the breeding season may yield biased estimates of nesting success in burrowing owls (and possibly other species), and some of the variation in nesting success among years and across study sites may be explained by annual and spatial variation in ambient temperature. Any management actions that result in fewer prairie dogs, shorter burrow lengths, or earlier nesting may adversely affect reproductive success of burrowing owls.
Do Sharp‐Tailed Grouse Select Loafing Sites to Avoid Visual or Olfactory Predators?
Authors: CONOVER MICHAEL R. , BORGO JENNIFER S.
Published: January 2009

ABSTRACT  Grouse should seek loafing sites hidden from predators; however, good hiding sites from predators that use vision to locate prey differ from good hiding sites from predators that use odor to locate prey. We compared characteristics of control sites to sites used for loafing by sharp‐tailed grouse (Tympanuchus phasianellus) to determine whether selection of loafing sites was more influenced by the need to hide from visual or olfactory predators. Sites used for loafing were similar to control sites in characteristics that would help hide a grouse from visual predators (i.e., visual obstruction, lateral visibility, visual obstruction, cover ht, and surface roughness), but loafing sites differed from control sites in characteristics that would help hide a grouse from olfactory predators (i.e., greater updrafts, wind velocities, and atmospheric turbulence).
Utility of Expert‐Based Knowledge for Predicting Wildlife‐Vehicle Collisions
Authors: HURLEY MICHAEL V. , RAPAPORT ERIC K. , JOHNSON CHRIS J.
Published: January 2009

ABSTRACT  Wildlife‐vehicle collisions have important ecological, economic, and social effects. In North America and across northern Europe, moose (Alces alces) are one of the largest ungulates hit by motor vehicles. The force and increasing frequency of these collisions has resulted in a commitment by wildlife and transportation agencies to limit or reduce causal factors. In an effort to improve these mitigation strategies, we used the most readily available source of knowledge of collision factors, expert opinion, to develop a series of models that explained and predicted location of moose‐vehicle collisions (MVC). We developed expert‐based models using the Analytical Hierarchy Process (AHP) and we used a structured survey approach where experts could assess criteria relevancy, weight criteria, and review weights for consistency. We hypothesized that collisions were the product of habitat‐ or driver‐related factors and we formulated the survey accordingly. We used the receiver operating characteristic to validate the resulting models and the Kappa index of agreement to quantify differences among spatial predictions originating from the experts. Local and nonlocal experts weighted the moose habitat classification as the most important criterion for identifying MVC. Among driver‐related criteria, speed limit was weighted as the most important factor. Overall, habitat‐based models were more proficient than driver‐based models in predicting MVC within Mount Revelstoke and Glacier National Parks, Canada. Both local and nonlocal expert models were excellent predictors of MVC, with local experts slightly outperforming nonlocal experts. Considering that habitat‐related criteria were more powerful for predicting MVC, and that habitat can vary considerably across study areas, we suggest that local experts be used when possible. The AHP is a valuable tool for wildlife, highway, and park managers to better understand why and where wildlife‐vehicle collisions occur. Adopting this process, our data suggested that MVC were most strongly correlated with highway attractants associated with habitat. Vegetation management or alternative routing could minimize spatial juxtaposition of moose and motor vehicles.
Letter: Is Delong Having his Cake and Eating it Too?
Authors: Schreiner Brian
Published: January 2009

The recent article, "Stocks for the Long Run" by J. Bradford Delong, left Brian Schreiner scratching his head.
Temperature Effects in Up-Conversion Processes of Erbium - Ytterbium Doped Oxyfluoride Silicate Glass
Authors: Grube J. , Sarakovskis A. , Dimitrocenko L. , Springis M.
Published: January 2009

Temperature Effects in Up-Conversion Processes of Erbium - Ytterbium Doped Oxyfluoride Silicate Glass

Er3+- Yb3+doped oxyfluoride glass has been synthesized and investigated. It was found that the up-conversion spectrum of the sample excited by a 980 nm laser diode is highly dependent on the temperature of the sample. Using fluorescence intensity ratio technique the green up-conversion emissions at 525 nm and 550 nm were studied in detail in the temperature range 120-600 K. The potential applicability of the obtained results in the field of the temperature sensing is discussed.
Sulfonated Poly(Ether-Ether-Ketone) Polymer Membranes for Fuel Cells
Authors: Hodakovska J. , Kleperis J.
Published: January 2009

Sulfonated Poly(Ether-Ether-Ketone) Polymer Membranes for Fuel Cells

In the work, sulfonated poly(ether-ether-ketone) (SPEEK) ionomers were synthesized using an original (submitted for patent) and simple method. The resulting membranes were tested to determine parameters that are important for the use of this material in fuel cells (water absorption, sulfonation degree, conductivity, etc.). The thermo-gravimetric analysis has shown a good thermal stability in the range from RT to 200-220 °C, and two characteristic regions of weight loss - 7.4% at ~140 °C (reversible water loss) and 10.3% at 200-220 °C (due to polymer degradation when cross-linked polymer chains permanently break down and their SO3H-groups are lost). The conductivity values obtained by the through-plane measurements of SPEEK membranes were 12 mS/cm at RT and 23 mS/cm at 80 °C.
Breeding and Demographic Parameters and Range Expansion of the Common Rosefinch (Carpodacus erythrinus)
Authors: Payevsky Vladimir
Published: January 2009

Breeding and Demographic Parameters and Range Expansion of the Common Rosefinch (Carpodacus erythrinus)

Breeding biology, age structure and other population parameters of the Common Rosefinch, collected on the Courish Spit of the Baltic Sea, are presented. The results are compared with similar population characteristic in different parts of the range. All materials, especially the proportion of breeding yearling males, are discussed in connection with the process of range expansion of the species. The expectation of greater proportion of yearling males in new areas did not proved.
Time for Municipal Elder Rights Law: An Anglo-Canadian Perspective
Authors: Doron Israel
Published: January 2009

En cette ère de mondialisation et de privatisation, les gouvernements locaux et les municipalités cherchent à définir leur rôle et leur place dans la société. Dans une société vieillissante comme le Canada, faire valoir que les droits juridiques des aînés devraient faire partie du fondement juridique des obligations municipales n'est pas simple. Il est moins compliqué de soutenir que sans une machine centralisée efficace les problèmes sociaux et environnementaux demeureront insolubles ou non traités.

Le présent article propose une idée différente de la place de l'administration municipale au Canada. L'article vise à présenter un argument original en politique juridique: il est temps que les communautés locales et les gouvernements locaux au Canada utilisent leur droits fondamentaux pour adopter des règlements locaux qui définissent et établissent les droits des citoyens âgés. L'oargument maintient que les municipalités locales détiennent le pouvoir légal et le potentiel social leur permettant d'oapporter une contribution importante à la promotion des droits des aînés dans la sphère politique, et que ce pouvoir a été jusqu'oà maintenant négligé.

L'oarticle soutient l'oargument de trois façons: 1) une analyse empirique des règlements existants dans diverses municipalités du Canada; 2) une analyse socio-légale des avantages de la loi municipale comme outil de changement social; et 3) une analyse par cas d'oune récente réforme des lois municipales dans la province de la Colombie-Britannique.
Pushed Output, Noticing, and Development of Past Tense Morphology in Content-Based Instruction
Authors: Leeser Michael J.
Published: January 2009

This study examines the effects of learners' production (i.e., pushed output) during a multi-stage reconstruction task on learners' noticing of Spanish past tense morphology, aural text comprehension, and development of preterite/imperfect usage in writing. Participants included 47 intermediate L2 Spanish learners in a content-based course at the university level. One group of learners (+output) listened to a series of passages and engaged in text reconstruction tasks. The other group (−output) listened to the same texts but answered multiple-choice comprehension questions instead of reconstructing the texts. Learners' notes during the listening phase of the tasks served as a noticing measure, and writing tasks were used as pre- and post-treatment measures. Results reveal that the +output group (a) reported more noticing of words overall, but not of past tense forms; (b) comprehended more information from the text; and (c) showed evidence of past tense development in their writing.
Towards a Better Understanding of Academic Acculturation: Second Language Students in Canadian Universities
Authors: Cheng Liying , Fox Janna
Published: January 2009

The aggressive internationalization of Canadian universities and increased immigration to Canada over the past 20 years have resulted in a dramatic increase in the number of second language (L2) students in Canadian universities. However, little is known about the factors that influence academic acculturation of L2 students or about the role of English for academic purposes (EAP) instruction in their acculturation process. This study examined L2 university students' perceptions of academic acculturation and the role of EAP instruction by means of interviews conducted with 56 L2 students at three Canadian universities. Findings suggest that the students who characterized their academic engagement as successful had typically developed more strategic learning and social skills as part of their acculturation process. Implications are drawn for the importance of aligning students' agendas for learning (i.e., their perceptions of needs) with EAP programs.
Minnesota's Proposal for Urban Partnership Agreement
Authors: Munnich Lee W.
Published: January 2009

In 2007 Minnesota was one of five finalists for an Urban Partnership Agreement (UPA) grant through a unique competition initiated by the U.S. Department of Transportation (USDOT). Minnesota was awarded a $133-million UPA grant by the USDOT to use congestion pricing in combination with other strategies to reduce congestion in a major transportation corridor. In 2005 Minnesota had previously adapted a high-occupancy vehicle lane to a high-occupancy toll (HOT) lane on I-394 west of downtown Minneapolis. These HOT lanes are known as MnPASS lanes. The UPA project will extend the MnPASS lanes to I-35W south of Minneapolis, the most heavily traveled stretch of urban Interstate in the Minneapolis–St. Paul metropolitan area. The proposal includes the use of priced dynamic shoulder lanes to make more efficient use of existing capacity as well as improved transit, telecommuting, and technology support in the corridor and in downtown Minneapolis. The significant federal dollar commitment to funding UPA projects, particularly through transit funding, has played a key role in generating political and institutional dialogue and support, especially among local government elected officials and legislators in the I-35W corridor. Stakeholder workshops have been an important outreach and education mechanism to inform and engage elected officials and other key constituents during the UPA application process.
Toward the Evaluation of Value Pricing
Authors: Lee Douglass B.
Published: January 2009

Value pricing—a form of multiclass service in which the user has the choice of an unpriced standard service or a faster service that is priced—has often been evaluated by comparison with high-occupancy vehicle lanes and also by inclusion of additional capacity as part of the project alternative. From the standpoint of benefit–cost analysis, this is not the right comparison. The question of whether to invest in additional capacity should be kept separate from the best way to operate it. Value pricing should be judged against other ways of using the same physical capacity, specifically, a single-class service either priced or unpriced. In addition, two factors not explicitly included in previous evaluations—partitioning a single facility into separate services diminishes total capacity, and capacity may be further reduced if the traffic flow goes from saturated to oversaturated (hypercongestion)—give multiclass service a significant disadvantage to overcome relative to single-class service. The net benefits of value pricing thus depend on whether the heterogeneity of vehicle time values (through occupancy or individual time values) is great enough to overcome the disadvantages of creating separate facilities for each service. The points are illustrated via a simplified numerical example that concentrates on only operational considerations and assumes a given total hourly traffic flow, so the results are no more than suggestive.
A Novel Block-based Watermarking Scheme Using the SVD Transform
Authors: Basso Alessandro , Bergadano Francesco , Cavagnino Davide , Pomponiu Victor , Vernone Annamaria
Published: January 2009

In this paper, a block-based watermarking scheme based on the Singular Value Decomposition (SVD) is proposed. Our watermark, a pseudo-random Gaussian sequence, is embedded by modifying the angles formed by the right singular vectors of each block of the original image. The orthogonality property of the right singular vector matrix is preserved during the embedding process. Several experiments have been carried out to test the performance of the proposed scheme against different attack scenarios. We conclude that the proposed scheme is resistant against common signal processing operations and attacks, while it preserves the quality of the original image.
Relative Validity and Reproducibility of a Food-Frequency Questionnaire for Estimating Food Intakes among Flemish Preschoolers
Authors: Huybrechts Inge , De Backer Guy , De Bacquer Dirk , Maes Lea , De Henauw Stefaan
Published: January 2009

The aims of this study were to assess the relative validity and reproducibility of a semi-quantitative food-frequency questionnaire (FFQ) applied in a large region-wide survey among 2.5-6.5 year-old children for estimating food group intakes. Parents/guardians were used as a proxy. Estimated diet records (3d) were used as reference method and reproducibility was measured by repeated FFQ administrations five weeks apart. In total 650 children were included in the validity analyses and 124 in the reproducibility analyses. Comparing median FFQ1 to FFQ2 intakes, almost all evaluated food groups showed median differences within a range of ± 15%. However, for median vegetables, fruit and cheese intake, FFQ1 was > 20% higher than FFQ2. For most foods a moderate correlation (0.5-0.7) was obtained between FFQ1 and FFQ2. For cheese, sugared drinks and fruit juice intakes correlations were even > 0.7. For median differences between the 3d EDR and the FFQ, six food groups (potatoes & grains; vegetables Fruit; cheese; meat, game, poultry and fish; and sugared drinks) gave a difference > 20%. The largest corrected correlations (>0.6) were found for the intake of potatoes and grains, fruit, milk products, cheese, sugared drinks, and fruit juice, while the lowest correlations (
Antimicrobial Activity of Some Thiourea Derivatives and Their Nickel and Copper Complexes
Authors: Arslan Hakan , Duran Nizami , Borekci Gulay , Koray Ozer Cemal , Akbay Cevdet
Published: January 2009

Five thiourea derivative ligands and their Ni2+ and Cu2+ complexes have been synthesized. The compounds were screened for their in vitro anti-bacterial activity using Gram-positive bacteria (two different standard strains of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes, Bacillus cereus) and Gram-negative bacteria (Esherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, Proteus vulgaris, Enterobacter aerogenes) and in vitro anti-yeast activity (Candida albicans, Candida krusei, Candida glabrata, Candida tropicalis, Candida parapsilosis). The minimum inhibitory concentration was determined for all ligands and their complexes. In vitro anti-yeast activity of both ligands and their metal complexes is greater than their in vitro anti-bacterial activity. The effect of the structure of the investigated compounds on the antimicrobial activity is discussed.
Reversible Storage of Lithium in a Rambutan‐Like Tin–Carbon Electrode
Authors: Deng Da , Lee Jim Yang
Published: January 2009

„Fruchtige“ Elektroden: Eine einfache Bottom‐up‐Methode wurde zum Aufbau von Rambutan‐förmigen Zinn‐Kohlenstoff(Sn@C)‐Nanoarchitekturen verwendet (siehe Schema; grün Sn), um die reversible Speicherung von Lithium in Zinnmaterialien zu verbessern. Der Wachstumsmechanismus der birnenförmigen Härchen wird untersucht.

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Proteomic Analysis of Plasma Membrane Vesicles
Authors: Bauer Brigitte , Davidson Max , Orwar Owe
Published: January 2009

Eine einfache und skalierbare Methode, die das Sammeln, die Reinigung und das Prozessieren auf einem Chip von Säuger‐Plasmamembranvesikeln (PMVs) vorsieht, wurde für die Proteomanalyse optimiert. Nach der Immobilisierung von PMVs auf einer Mikrofluidikzelle werden die eingebetteten Membranproteine proteolytisch abgebaut, und die erhaltenen Peptide konnten durch LC‐MS/MS analysiert werden. Über 93 % der detektierten Proteine stammten aus der Plasmamembran.

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Protein‐Functionalized Synthetic Antiferromagnetic Nanoparticles for Biomolecule Detection and Magnetic Manipulation
Authors: Fu Aihua , Hu Wei , Xu Liang , Wilson Robert J. , Yu Heng , Osterfeld Sebastian J. , Gambhir Sanjiv S. , Wang Shan X.
Published: January 2009

Die direkte Proteinfunktionalisierung ergibt synthetische antiferromagnetische Nanopartikel mit hoher chemischer Spezifität und vielfältigen Funktionen. Diese Nanopartikel‐Protein‐Konjugate wirken als verbesserte magnetische Markierungen für biologische Analysen und reagieren in einstellbarer Weise auf kleine äußere Magnetfeldgradienten, sodass sich die Bewegung einzelner Nanopartikel verfolgen lässt.

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Electronic Absorption Spectra and Redox Properties of C Type Cytochromes in Living Microbes
Authors: Nakamura Ryuhei , Ishii Kazuyuki , Hashimoto Kazuhito
Published: January 2009

Shewanella ist eine elektrogene Mikrobe, die beträchtliche Mengen an c‐Cytochromen enthält (ca. 0.5 mM). Durch diese Eigenschaft gelingt es, die optischen Absorptionsspektren der zellmembranassoziierten Proteine während extrazellulärer respiratorischer Elektronentransferreaktionen in vivo zu verfolgen. Es ergeben sich signifikante Unterschiede zu Resultaten, die mit gereinigten Proteinen in vitro erhalten wurden.

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A Pyrrolysine Analogue for Protein Click Chemistry
Authors: Fekner Tomasz , Li Xin , Lee Marianne M. , Chan Michael K.
Published: January 2009

Mithilfe des UAG‐Codons wurde ein Pyrrolysin‐Analogon mit terminaler Alkinfunktion ortsspezifisch in rekombinantes Calmodulin (CaM) eingebaut. Das resultierende Protein wurde über eine Kupfer(I)‐katalysierte Klick‐Reaktion mit der Azidgruppe eines Farbstoffs verknüpft. Die anschließende Anwendung einer orthogonalen Cystein‐Markierungsmethode ergab mit zwei unterschiedlichen Fluorophoren markiertes CaM für FRET‐Studien.

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A Palladium(II)‐Catalyzed Synthesis of Spiroacetals through a One‐Pot Multicomponent Cascade Reaction
Authors: Barluenga José , Mendoza Abraham , Rodríguez Félix , Fañanás Francisco J.
Published: January 2009

Funktionalisierte Spiroacetale sind durch eine Dreikomponentenkupplung von Pentinolderivaten, Salicylaldehyden und Aminen in Gegenwart katalytischer Mengen eines Palladium(II)‐Komplexes zugänglich (siehe Schema). Alternativ können Spiroacetale mit Sauerstoffsubstituenten erhalten werden, wenn man Orthoester als dritte Komponente einsetzt.

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Receptor‐Mediated Targeting of Cathepsins in Professional Antigen Presenting Cells
Authors: Hillaert Ulrik , Verdoes Martijn , Florea Bogdan I. , Saragliadis Anastasios , Habets Kim L. L. , Kuiper Johan , Van Calenbergh Serge , Ossendorp Ferry , van der Marel Gijsbert A. , Driessen Christoph , Overkleeft Hermen S.
Published: January 2009

Speziell für professionelle Zellen: Ein Mannosid‐DCG‐04‐Analog mit Fluoreszenzmarkierung (siehe Struktur) wurde nach einem modularen Verfahren entworfen und synthetisiert. Die Aufnahme der Sonde in professionelle antigenpräsentierende Zellen und die anschließende Markierung von Cathepsinen waren vom Mannoserezeptor abhängig.

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Enantiomerically Pure Chiral {Fe28} Wheels
Authors: Zhang Zhi‐Ming , Li Yang‐Guang , Yao Shuang , Wang En‐Bo , Wang Yong‐Hui , Clérac Rodolphe
Published: January 2009

Eisenräder kommen groß raus: Zwei enantiomerenreine radförmige {Fe28}‐Aggregate wurden in einer Acetatpufferlösung aus Eisen(III)‐Ionen und chiralen Tartratliganden hergestellt (siehe Bild). Die Verbindungen sind die größten bisher isolierten chiralen Eisen(III)‐Aggregate.

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Protein‐Functionalized Synthetic Antiferromagnetic Nanoparticles for Biomolecule Detection and Magnetic Manipulation
Authors: Fu Aihua , Hu Wei , Xu Liang , Wilson Robert J. , Yu Heng , Osterfeld Sebastian J. , Gambhir Sanjiv S. , Wang Shan X.
Published: January 2009

Direct protein functionalization provides synthetic antiferromagnetic nanoparticles with high chemical specificity and multifunctionality. These nanoparticle–protein conjugates function as improved magnetic labels for biological detection experiments, and exhibit tunable responses to a small external magnetic field gradient, thus allowing the observation of distinctive single nanoparticle motion.

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Size‐Dependent Ordering of Liquid Crystals Observed in Polymeric Capsules with Micrometer and Smaller Diameters
Authors: Gupta Jugal K. , Sivakumar Sri , Caruso Frank , Abbott Nicholas L.
Published: January 2009

Made to order: Aqueous dispersions of polymer‐encapsulated liquid crystal (LC) droplets were synthesized with precise interfacial chemistry and sizes in the micrometer‐to‐sub‐micrometer range. Size‐dependent changes in LC ordering could be observed. Study of the competition between size and interfacial chemistry on LC ordering enables size‐dependent properties of LC droplets to be exploited in applications such as photonics and sensing.

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Supramolecular “Double‐Propeller” Dimers of Hexanuclear CuII/LnIII Complexes: A {Cu3Dy3}2 Single‐Molecule Magnet
Authors: Novitchi Ghenadie , Wernsdorfer Wolfgang , Chibotaru Liviu F. , Costes Jean‐Pierre , Anson Christopher E. , Powell Annie K.
Published: January 2009

Propelling magnetism: Supramolecular organization leads to a remarkable dodecanuclear {Cu3Dy3}2 cluster with a “double–propeller” shape (see picture). The linkages of the CuDy units, both intramolecular and supramolecular, appear to be responsible for a drastic change in the single molecule magnetic behavior.

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Artificial Ribozyme Switches Containing Natural Riboswitch Aptamer Domains
Authors: Wieland Markus , Benz Armin , Klauser Benedikt , Hartig Jörg S.
Published: January 2009

RNA Lego: The use of natural riboswitch aptamers in synthetic RNA switches (see picture) should broaden the scope of artificial RNA regulators dramatically. It is shown that thiamine pyrophosphate (TPP) aptamers can be used in engineered devices as very sensitive switches of gene expression in unmodified organisms. The approach demonstrates that intrinsic metabolites can be utilized as external effectors of cellular functions.

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A Chiral Concave‐Bound Cyclopentadienyl Iron Complex of Sumanene
Authors: Sakane Hiroyuki , Amaya Toru , Moriuchi Toshiyuki , Hirao Toshikazu
Published: January 2009

Great bowls of fire: The rotation of the cyclopentadienyl (Cp) ring is restricted in two concave‐bound monoalkyl‐substituted [CpFe(η6‐sumanene)]+ “π‐bowl” complexes (see picture). The asymmetric stacking of atropisomers was observed with a MeCpFe complex in the solid state and the chiral (S)‐sBuCpFe complex showed magnetic and optical desymmetrization of the sumanene ligand, which is the first example of a chiral complex of a π‐bowl ligand.

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Enantiomerically Pure Chiral {Fe28} Wheels
Authors: Zhang Zhi‐Ming , Li Yang‐Guang , Yao Shuang , Wang En‐Bo , Wang Yong‐Hui , Clérac Rodolphe
Published: January 2009

Wheels of steel: Two enantiomerically pure chiral {Fe28} wheel‐like aggregates have been synthesized from the acetate buffer solution containing ferric ions and chiral tartrate ligands (see picture). These compounds are the largest chiral ferric aggregates isolated to date.

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Pharmacodynamics of glucose regulation by methylprednisolone. II. normal rats
Authors: Jin Jin Y. , Jusko William J.
Published: January 2009

A physiologic pharmacodynamic model was developed to jointly describe the effects of methylprednisolone (MPL) on adrenal suppression and glycemic control in normal rats. Six groups of animals were given MPL intravenously at 0, 10 and 50 mg/kg, or by subcutaneous 7 day infusion at rates of 0, 0.1 and 0.3 mg/kg/h. Plasma concentrations of MPL, corticosterone (CST), glucose and insulin were determined at various times up to 72 h after injection and 336 h after infusion. The pharmacokinetics of MPL was described by a two‐compartment model. A circadian rhythm for CST was found in untreated rats with a stress‐altered baseline caused by handling, which was captured by a circadian harmonic secretion rate with an increasing mesor. All drug treatments caused CST suppression. Injection of MPL caused temporary increases in glucose over 4 h. Insulin secretion was thereby stimulated yielding a later peak around 6 h. In turn, insulin can normalize glucose. However, long‐term dosing caused continuous hyperglycemia during and after infusion. Hyperinsulinemia was achieved during infusion, but diminished immediately after dosing despite the high glucose concentration. The effects of CST and MPL on glucose production were described with a competitive stimulation function. A disease progression model incorporating reduced endogenous glucose uptake/utilization was used to describe glucose metabolism under different treatments. The results exemplify the roles of endogenous and exogenous hormones in mediating glucose dynamics. The pharmacokinetic/pharmacodynamic model is valuable for quantitating diabetogenic effects of corticosteroid treatments and provides mechanistic insights into the hormonal control of the metabolic system. Copyright © 2009 John Wiley & Sons, Ltd.
The Homoscleromorph sponge Oscarellalobularis, a promising sponge model in evolutionary and developmental biology
Authors: Ereskovsky Alexander V. , Borchiellini Carole , Gazave Eve , Ivanisevic Julijana , Lapébie Pascal , Perez Thierry , Renard Emmanuelle , Vacelet Jean
Published: January 2009

Sponges branch basally in the metazoan phylogenetic tree and are believed to be composed of four distinct lineages with still uncertain relationships. Indeed, some molecular studies propose that Homoscleromorpha may be a fourth Sponge lineage, distinct from Demospongiae in which they were traditionally classified. They harbour many features that distinguish them from other sponges and are more evocative of those of the eumetazoans. They are notably the only sponges to possess a basement membrane with collagen IV and specialized cell‐junctions, thus possessing true epithelia. Among Homoscleromorphs, we have chosen Oscarella lobularis as a model species. This common and easily accessible sponge is characterized by relatively simple histology and cell composition, absence of skeleton, and strongly pronounced epithelial structure. In this review, we explore the specific features that make O. lobularis a promising homoscleromorph sponge model for evolutionary and developmental researches.
Microsatellite repeat instability and neurological disease
Authors: Brouwer Judith R. , Willemsen Rob , Oostra Ben A.
Published: January 2009

Over 20 unstable microsatellite repeats have been identified as the cause of neurological disease in humans. The repeat nucleotide sequences, their location within the genes, the ranges of normal and disease‐causing repeat length and the clinical outcomes differ. Unstable repeats can be located in the coding or the non‐coding region of a gene. Different pathogenic mechanisms that are hypothesised to underlie the diseases are discussed. Evidence is given both from studies in simple model systems and from studies on human material and in animal models. Since somatic instability might affect the clinical outcome, this is briefly touched on. Available data and theories on the timing and mechanisms of the repeat instability itself are discussed, along with factors that have been observed to affect instability. Finally, the question of why the often harmful unstable repeats have been maintained throughout evolution is addressed.
Citrate transport and metabolism in mammalian cells
Authors: Mycielska Maria E. , Patel Ameet , Rizaner Nahit , Mazurek Maciej P. , Keun Hector , Patel Anup , Ganapathy Vadivel , Djamgoz Mustafa B. A.
Published: January 2009

Citrate, an organic trivalent anion, is a major substrate for generation of energy in most cells. It is produced in mitochondria and used either in the Krebs' cycle or released into cytoplasm through a specific mitochondrial carriers. Citrate can also be taken up from blood through different plasma membrane transporters. In the cytoplasm, citrate can be used ultimately for fatty acid synthesis, which is increased in cancer cells. Here, we review the ways in which citrate can be transported and discuss the changes in transport and metabolism that occur in cancer cells. The primary focus is on the prostate gland, which is known to produce and release large amounts of citrate during its normal secretory function. The significant changes that occur in citrate‐related metabolism and transport in prostate cancer are the second focus. This review strives to relate these mechanisms to molecular biology on the one hand and to clinical applications on the other.
MicroRNA expression profiling in bone marrow: Implications in hematological malignancies
Authors: Costa Ana , Osório Catarina , Dias Sérgio
Published: January 2009

MicroRNA (miRNA) have been recently attributed a crucial role in the control of gene expression in numerous physiological and pathological processes including growth, differentiation and even oncogenesis. Besides detailed mechanistic studies on their generation and function, there has been a great deal of interest in the study of miRNA as surrogate markers of disease. Numerous studies have attempted to define miRNA profiles as predictors of disease outcome, or for the classification/diagnosis of different pathologies. In the present review, we summarize the main studies describing the involvement of miRNA in bone marrow (BM) diseases and in normal BM function during hematopoiesis.
Site‐specific modification of the bovine genome using Cre recombinase‐mediated gene targeting.
Authors: Graham Catriona , Cole Sally , Laible Götz
Published: January 2009

Cre recombinase (Cre)‐mediated targeted insertion of a transgene is a powerful technique that can be used to tailor genomes. When combined with somatic cell nuclear transfer it could offer an efficient way to generate transgenic livestock with site‐specific genetic modifications that are free of antibiotic selection markers. We have engineered primary bovine fibroblasts to contain a chromosomal acceptor site with incompatible loxP/lox2272 sites for Cre‐mediated cassette exchange and show for the first time that Cre‐mediated targeting can be applied in these acceptor cells. Molecular characterization of the resulting cell clones revealed Cre‐mediated transgene insertion efficiencies of up to 98% when antibiotic selection was used to identify transgene containing cell clones. Most clonal lines also contained random insertions of the targeting and Cre expression plasmids with only about 10% of the clones being exclusively modified by the intended targeted insertion. This targeting efficiency was sufficient to enable the isolation of correctly targeted clones without the help of antibiotic selection. Therefore, this recombinase‐mediated insertion strategy has the potential to produce transgenic cattle from antibiotic selection marker‐free somatic cells with transgenes inserted into proven genomic loci ensuring reliable expression levels.
Electrospray‐ionization mass spectrometry as a tool for fast screening of protein structural properties
Authors: Grandori Rita , Santambrogio Carlo , Brocca Stefania , Invernizzi Gaetano , Lotti Marina
Published: January 2009

Since the early 1990s, electrospray‐ionization mass spectrometry (ESI‐MS) has encountered growing interest as a complementary tool to established biochemical and biophysical methods for investigating protein structure and conformation. Nowadays, applications of ESI‐MS to protein investigation span from the area of analytical biochemistry to that of structural biology. This review focuses on applications of this technique to the analysis of protein conformational properties and molecular interactions, underscoring their possible relevance for molecular biotechnology, although representing a still very young field. An introductive section presents the major issues related to theoretical and technical aspects of ESI‐MS under non‐denaturing conditions. Examples from our work and from the literature illustrate which kind of information can be obtained concerning key issues in biotechnology such as stability and aggregation of proteins under both near‐native and challenging conditions, and interactions with other proteins, ligands and cofactors.
Biphasic mini‐reactor for characterization of biocatalyst performance
Authors: van den Wittenboer Anne , Schmidt Thomas , Müller Pia , Ansorge‐Schumacher Marion B. , Greiner Lasse
Published: January 2009

Biphasic reaction media are extending the scope of technical biocatalysis. Thorough investigation of the factors affecting catalyst performance under these conditions is of key importance for the successful implementation of catalytic processes. Here, we present a reactor setup suitable for comprehensive systematic characterization and optimization of biocatalyzed reactions in biphasic systems with distinct phases. It is distinguished by small volumes allowing reproducible experimentation with minimum amounts of solvent and catalyst. The interfacial area is kept constant and independent stirring of both phases is allowed in order to minimize superimposing effects. Evaporation of low‐volatile organic solvents is prevented by use of airtight construction. The broad applicability of this mini‐reactor is demonstrated with regard to determination of mass transfer, enzyme productivity, and enzyme stability in both batch and continuous mode.
Political orientation and perceptions of adolescent autonomy and judicial culpability
Authors: Reppucci N. Dickon , Scott Elizabeth , Antonishak Jill
Published: January 2009

This study probed general attitudes about processing youths in adult criminal court across a range of offenses, explored attitudes about age of autonomous decision‐making for several activities outside the criminal justice context, and examined the interaction between these two realms. The major finding was that adults favor adult punishment of adolescent offenders at younger ages than they favor autonomy in other decision‐making contexts; the gap is widest for those who identify themselves as conservatives. Copyright © 2009 John Wiley & Sons, Ltd.
Modular hardware design for distant‐internet embedded systems engineering laboratory
Authors: Yue Xicai , Drakakis E. M. , Harkin J. , Callaghan M. J. , McGinnity T. M. , Maguire L. P.
Published: January 2009

A novel hardware system providing remote accessible embedded system experiments of microcontroller, digital signal processor (DSP), and field‐programmable gate array (FPGA) via Internet is presented. Three newly developed hardware modules for integrating experimental boards, experimental instrumentation, and a PC workstation in the distant embedded laboratory are fully described. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 17: 389–397, 2009; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20259
Separation, optimization, miniaturization and signal space. Optimum measurability factors in process analytical chromatography
Authors: Smit Henri C.
Published: January 2009

The theory concerning optimum separation conditions with respect to the precision and minimum peak estimation error is extended with the derivation of the conditions for optimum measurability in case of chemical process control, resulting in extremely short columns to be used. High‐speed correlation chromatography (CC) with a special input device is suggested as a solution for the practical problems of these required columns. An example of a one‐second correlogram with a spark modulation input device is shown. An alternative is monitoring chemical processes by multiple input chromatography, applying a polynomial fit procedure. Copyright © 2009 John Wiley & Sons, Ltd.
Distinct Hydroxy‐Radical‐Induced Damage of 3′‐Uridine Monophosphate in RNA: A Theoretical Study
Authors: Zhang Ru bo , Eriksson Leif A.
Published: January 2009

Cutting ties: Strand scission and base release in hydroxy‐radical adducts of 3′‐uridine monophosphate (UMP) have been explored by using density functional theory. The presence of the ribose 2′‐OH group and the resultant formation of low‐barrier hydrogen bonds with oxygen atoms of the 3′‐phosphate linkage are highly important for hydrogen transfer and the subsequent bond‐breakage reactions (see picture).

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RNA strand scission and base release in 3′‐uridine monophosphate (UMP), induced by OH radical addition to uracil, is studied at the DFT B3LYP/6‐31+G(d,p) level in the gas phase and in solution. In particular, the mechanism of hydrogen‐atom transfer subsequent to radical formation, from C2′ on the sugar to the C6 site on the base, is explored. The barriers of (C2′‐)H2′a abstraction by the C6 radical site range from 11.2 to 20.0 kcal mol−1 in the gas phase and 14.1 to 21.0 kcal mol−1 in aqueous solution, indicating that the local surrounding governs the hydrogen‐abstraction reaction in a stereoselective way. The calculated N1C1′ (N1–glycosidic bond) and β‐phosphate bond strengths show that homolytic and heterolytic bond‐breaking processes are largely favored in each case, respectively. The barrier for β‐phosphate bond rupture is approximately 3.2–4.0 kcal mol−1 and is preferred by 8–12 kcal mol−1 over N1–glycosidic bond cleavage in both the gas phase and solution. The β‐phosphate bond‐rupture reactions are exothermal in the gas phase and solution, whereas N1C1′ bond‐rupture reactions require both solvation and thermal corrections at 298 K to be energetically favored. The presence of the ribose 2′‐OH group and its formation of low‐barrier hydrogen bonds with oxygen atoms of the 3′‐phosphate linkage are highly important for hydrogen transfer and the subsequent bond‐breakage reactions.
Proton Pump for O2 Reduction Catalyzed by 5,10,15,20‐Tetraphenylporphyrinatocobalt(II)
Authors: Partovi‐Nia Raheleh , Su Bin , Li Fei , Gros Claude P. , Barbe Jean‐Michel , Samec Zdenek , Girault Hubert H.
Published: January 2009

Oxygen reduction: A polarized water|1,2‐dichloroethane (DCE) interface acts as a proton pump for the [Co(tpp)] (TPP=5,10,15,20‐tetraphenylporphyrinato) catalyzed O2 reduction by ferrocene (Fc) compounds to produce H2O2 (see figure; IT=ion transfer, ET=electron transfer). This system favours the collection of H2O2 by extraction immediately after its formation in DCE to the adjacent water phase.

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The role of 5,10,15,20‐tetraphenylporphyrinatocobalt(II) ([Co(tpp)]) as a catalyst on molecular oxygen (O2) reduction by ferrocene (Fc) and its two derivatives, 1,1′‐dimethylferrocene (DFc) and decamethylferrocene (DMFc) at a polarized water|1,2‐dichloroethane (DCE) interface has been studied. The water|DCE interface essentially acts as a proton pump controlled by the Galvani potential difference across the interface, driving the proton transfer from water to DCE. [Co(tpp)] catalyzed O2 reduction by Fc, DFc and DMFc is then followed to produce hydrogen peroxide (H2O2). The catalytic mechanism is similar to that proposed by Fukuzumi et al. for bulk reactions. This interfacial system provides a platform for a very efficient collection of H2O2, by extraction immediately after its formation in DCE to the adjacent water phase, thus decreasing the possibility of degradation and further reaction with ferrocene derivatives.
Spectroscopy Probing of the Formation, Recognition, and Conversion of a G‐Quadruplex in the Promoter Region of the bcl‐2 Oncogene
Authors: Li Huihui , Liu Yiquan , Lin Sen , Yuan Gu
Published: January 2009

Which form to take? The interconversion between the G‐quadruplex and duplex DNA forms in the bcl‐2 promoter could be induced by fluctuations in the pH value or DNA and NH4+ concentrations, by adding CH3OH, and by introducing small molecules (cationic porphyrin and dehydrocorydaline; see scheme).

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This study has demonstrated the formation of the G‐quadruplex structure from the G‐rich sequence in the promoter region of the bcl‐2 oncogene; the formation could be induced by addition of NH4+ or K+ ions. The binding affinity and stoichiometry of seven small molecules with the G‐quadruplex were examined by using ESI‐MS, as well as CD and UV spectroscopy. The binding‐affinity order was determined to be P1≈P5>P2>P3≈P4>P7>P6. In particular, the small‐molecule induction of the structural transition between the G‐quadruplex and duplex DNA forms in this promoter region was investigated by ESI‐MS. We directly observed specific binding of dehydrocorydaline (P7) and cationic porphyrin (P5) in one system consisting of the G‐quadruplex and the duplex DNA, respectively. The results indicate that P7 selectively stabilizes the G‐quadruplex and shifts the equilibrium toward G‐quadruplex formation of the bcl‐2 promoter, whereas P5 converts the G‐quadruplex into the duplex DNA, which results in strong and selective binding to the duplex form. Therefore, P5 and P7 with their attractive binding specificities could be considered as precursors for pathway‐specific drug design for regulation of bcl‐2 oncogene transcription.
Influence of the Charge State on the Structures and Interactions of Vancomycin Antibiotics with Cell‐Wall Analogue Peptides: Experimental and Theoretical Studies
Authors: Yang Zhibo , Vorpagel Erich R. , Laskin Julia
Published: January 2009

Charge matters! The charge state significantly influences the conformation and the binding energy between vancomycin antibiotic and bacterial cell‐wall analogue peptides (see figure). Surface‐induced dissociation (SID) studies provide a quantitative comparison between the stabilities of different charge states of the complex.

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In this study we examined the effect of the charge state on the energetics and dynamics of dissociation of the noncovalent complex between the vancomycin and the cell‐wall peptide analogue Nα,Nε‐diacetyl‐L‐Lys‐D‐Ala‐D‐Ala (V–Ac2LKdAdA). The binding energies between the vancomycin and the peptide were obtained from the RRKM (Rice, Ramsperger, Kassel, Marcus) modeling of the time‐ and energy‐resolved surface‐induced dissociation (SID) experiments. Our results demonstrate that the stability of the complex towards fragmentation increases in the order: doubly protonated<singly protonated<deprotonated. Dissociation of the singly protonated and singly deprotonated complex is characterized by very large entropy effects, which indicate a substantial increase in the conformational flexibility of the resulting products. The experimental threshold energies of (1.75±0.08) eV ((40.3±1.8) kcal mol−1) and (1.34±0.08) eV ((30.9±1.8) kcal mol−1) obtained for the deprotonated and singly protonated complexes, respectively, are in excellent agreement with the results of density functional theory calculations. The increased stability of the deprotonated complex observed experimentally is attributed to the presence of three charged sites in the deprotonated complex, as compared with only one charged site in the singly protonated complex. The low binding energy of (0.93±0.04) eV ((21.4±0.9) kcal mol−1) obtained for the doubly protonated complex suggests that this ion is destabilized by Coulomb repulsion between the singly protonated vancomycin and the singly protonated peptide comprising the complex.
A Ratiometric Fluorescent Probe for Hypochlorite Based on a Deoximation Reaction
Authors: Lin Weiying , Long Lingliang , Chen Bingbing , Tan Wen
Published: January 2009

The first ratiometric fluorescent probe for hypochlorite has been developed through regulation of the electron‐withdrawing ability of the electron acceptor in an intramolecular charge‐transfer (ICT) system by a deoximation reaction (see figure; EWG=electron‐withdrawing group).

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In this work, we have successfully provided a novel strategy for the rational design and synthesis of a ratiometric fluorescent probe for hypochlorite. The strategy is based on the deoximation reaction, which has not yet been used in the fluorescent hypochlorite probe design. Interestingly, the probe showed a ratiometric fluorescent response to hypochlorite with the emission intensities ratio (I509/I439) increasing from 0.28 to 2.74. Furthermore, the probe displayed high selectivity for hypochlorite over other species due to the distinct deoximation conditions. The probe developed herein represents the first ratiometric fluorescent probe for hypochlorite.