bluuebunny/crossref_metadata_2025 huggingface dataset:
Tax Reporting Aggressiveness and Its Relation to Aggressive Financial Reporting
Authors: Frank Mary Margaret , Lynch Luann J. , Rego Sonja Olhoft
Published: March 2009

ABSTRACT: We investigate the association between aggressive tax and financial reporting and find a strong, positive relation. Our results suggest that insufficient costs exist to offset financial and tax reporting incentives, such that nonconformity between financial accounting standards and tax law allows firms to manage book income upward and taxable income downward in the same reporting period. To examine the relation between these aggressive reporting behaviors, we develop a measure of tax reporting aggressiveness that statistically detects tax shelter activity at least as well as, and often better than, other measures. In supplemental stock returns analyses, we confirm that the market overprices financial reporting aggressiveness. We also find that the market overprices tax reporting aggressiveness, but only for firms with the most aggressive financial reporting.
The Association between Management Earnings Forecast Errors and Accruals
Authors: Gong Guojin , Li Laura Yue , Xie Hong
Published: March 2009

ABSTRACT: We investigate the association between errors in management forecasts of subsequent year earnings and current year accruals. In an uncertain operating environment, managers' assessments of their firms' business prospects are imperfect. Since managers' imperfect business assessments influence both accruals generation and earnings projection, we hypothesize that management earnings forecasts exhibit greater optimism (pessimism) when accruals are relatively high (low). Consistent with this hypothesis, we find a positive association between management earnings forecast errors and accruals. This positive association is stronger for firms operating in a more uncertain business environment and for firms in industries exhibiting greater covariation between accruals and growth-related activities. Moreover, this positive association is significant when accruals likely reflect managers' true beliefs about firms' business prospects, but is nonexistent when accruals are likely manipulated to boost managers' trading gains. Supplementary analysis reveals that the presence of management earnings forecasts does not significantly reduce accrual mispricing.
Auditor Switches in the Pre- and Post-Enron Eras: Risk or Realignment?
Authors: Landsman Wayne R. , Nelson Karen K. , Rountree Brian R.
Published: March 2009

ABSTRACT: Using a comprehensive sample of switches to and from the largest auditors (i.e., the Big N), we examine empirically whether the sensitivity of Big N auditor switches to client risk and misalignment changed between the pre- and post-Enron periods. Although we find an increase in the sensitivity to client misalignment, the sensitivity to client risk generally decreases. The results are consistent with Big N auditors rebalancing their audit client portfolios in response to post-Enron capacity constraints arising from the supply of former Arthur Andersen clients and the audit demands imposed by Sarbanes-Oxley rather than increasing their sensitivity to client risk. Additional evidence indicates that the Sarbanes-Oxley demand shock did not affect Big N auditor switching behavior incremental to the initial Andersen supply shock.
Employee Discretion and Performance Pay
Authors: Ortega Jaime
Published: March 2009

ABSTRACT: This study examines the relationship between performance pay and the decision to delegate the choice of work methods and scheduling. I compare two theoretical approaches, based on specific knowledge and measurement costs, respectively. Both perspectives suggest a complementarity between discretion and performance pay, but the former predicts a positive effect of job complexity on discretion and performance pay, and the latter implies a negative effect. Results suggest that group and firm-wide incentives are used to decentralize decisions and to take advantage of employees' specific knowledge, whereas piece rates are driven by performance measurement considerations and are not associated with more discretion.
In Vivo Evaluation of DIAGNOdent for the Quantification of Occlusal Dental Caries
Authors: Khalife M. A. , Boynton J. R. , Dennison J. B. , Yaman P. , Hamilton J. C.
Published: March 2009

Clinical Relevance

There is a weak correlation between DIAGNOdent readings and carious lesion depth and volume. Based on the current study, the appropriate DIAGNOdent cut-off point to detect carious lesions reaching the DEJ or beyond is between 35 and 40.
Effect of Fiber Nets, Application Techniques and Flowable Composites on Microleakage and the Effect of Fiber Nets on Polymerization Shrinkage in Class II MOD Cavities
Authors: Ozel E. , Soyman M.
Published: March 2009

Clinical Relevance

Fiber nets applied to Class II composite restorations resulted in a significant reduction in microleakage. Fiber nets also decreased polymerization shrinkage. Therefore, these materials may be acceptable for clinical applications. Incremental placement remains the preferred restorative technique for posterior composite restorations.
Durability of Enamel Bonding Using One-step Self-etch Systems on Ground and Unground Enamel
Authors: Reis A. , Moura S. K. , Pellizzaro A. , Dal-Bianco K. , Andrade A. M. , Grande R. H. M. , Loguercio A. D.
Published: March 2009

Clinical Relevance

The improvement of resin-enamel bond strengths after using Si-C paper and diamond burs for enamel preparation is material dependent. No degradation of enamel bond strength could be observed for any one-step self-etch adhesive system after 12 months of water storage.
Effect of Acid Neutralization and Mechanical Cycling on the Microtensile Bond Strength of Glass-ceramic Inlays
Authors: Saavedra G. , Ariki E. K. , Federico C. D. , Galhano G. , Zamboni S. , Baldissara P. , Bottino M. A. , Valandro L. F.
Published: March 2009

Clinical Relevance

Acid neutralization of the ceramic surface etched with hydrofluoric acid appears to be unnecessary.
Effect of Enamel Etching Time on Roughness and Bond Strength
Authors: Barkmeier W. W. , Erickson R. L. , Kimmes N. S. , Latta M. A. , Wilwerding T. M.
Published: March 2009

Clinical Relevance

Traditionally, etch-and-rinse adhesive systems have used phosphoric acid to condition enamel surfaces and successfully create a strong, durable bond to resin-based materials. Newer adhesive systems now use acid monomers to bond resin materials to both enamel and dentin. These newer adhesives do not provide the same degree of bonding to enamel as etch-and-rinse systems, and extending the application time does not improve their performance.
Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite
Authors: Spazzin A. O. , Galafassi D. , de Meira-Júnior A. D. , Braz R. , Garbin C. A.
Published: March 2009

Clinical Relevance

According to finite element analysis, the zirconia ceramic post created higher stress levels in the post and slightly less in dentin compared with glass fiber posts. Resin cement with a high elastic modulus created higher stress levels in the cement layer. The different film thicknesses of cement did not create significant changes in stress levels.
Review of the Effectiveness of Various Tooth Whitening Systems
Authors: Matis B. A. , Cochran M. A. , Eckert G.
Published: March 2009

Clinical Relevance

Tooth whitening is observable with all methods of bleaching. Dentist-prescribed overnight bleaching was shown to be the most effective method of bleaching.
Vehicle Suspension Measurements: Evaluation of the Benefits of Dynamic over Quasistatic Kinematics and Compliance Testing
Authors: Wei T. E. , Dorfi H. R.
Published: March 2009

Vehicle dynamics packages can be used to simulate handling or braking maneuvers that would otherwise need to be performed outdoors. Many of the parameters for these types of vehicle models are determined through kinematics and compliance (K&C) measurements. Machines that perform these measurements apply various forces or moments and measure the response of the vehicle. The rate that these forces or moments are applied can be quasistatic or dynamic. Machines that are capable of performing dynamic tests are more expensive due to the need for inertia compensation, sensors that can acquire data at higher rates, and larger actuators or hydraulic power supplies. However, it is possible that measurements of dynamic vehicle response may increase the fidelity of parameter identification, compared to the sole use of quasistatic tests. One reason that parameter identification may be more accurate is the rate of force and moment application in dynamic tests is more like those in the actual maneuvers that are desirable to simulate.

A study was performed to determine where the advantages of performing dynamic K&C testing lie. Quasistatic K&C tests, along with dynamic tests performed at several frequencies up to 3.0 Hz, were performed on the front axle of a front-wheel drive compact sedan, using an MTS Systems High-Rate K&C Machine. Assessment of any advantages of dynamic K&C testing has been made through correlations of the vehicle response between dynamic and quasistatic tests.
Examination of the Structure and Micro-Hardness of a Laser-Constituted Surface Layer Deposited on the Constructional Steel
Authors: Kłysz Sylwester , Bień Anna
Published: March 2009

Examination of the Structure and Micro-Hardness of a Laser-Constituted Surface Layer Deposited on the Constructional Steel

The paper has been intended to present results of the micro- and macroscopic examination of the structure, as well as measurements of micro-hardness of surface layers of specimens made from the toughening (heat-treatable) constructional steel 50H subjected to laser hardening. Basing on X-ray examination with the DRON-4 and the Seifert XRD 3003 diffractometers, parameters of crystalline lattice and quantitative contents of particular phases have been found.
A Method to Estimate Operational Fatigue Life of Aeronautical Structural Components and Experimental Verification Thereof - An Outline
Authors: Tomaszek Henryk , Żurek Józef , Kłysz Sylwester
Published: March 2009

A Method to Estimate Operational Fatigue Life of Aeronautical Structural Components and Experimental Verification Thereof - An Outline

The study presents an attempt to estimate fatigue life of structural components with further verification of the applied method by means of testing the specimens taken. Therefore, it has been assumed that a specimen subjected to tests is a structural component of a real system, and operational loads have been simulated in the form of a predefined loading scheme. All parameters necessary for the method have been derived from the analyses of both the specimens subjected to tests and properties of the preset load spectrum.

The applied method of fatigue life estimation represents a probabilistic approach based on the Paris formula for the crack growth rate, and on difference equations that after some transformation result in an equation of the Fokker-Planck type. A probability density function of a crack length is a solution to this equation and depends on either the total time of operating the component in question or the number of load cycles applied.

The probability density function of a crack length has been used to find out a formula for the probability of not exceeding the permissible crack length against the number of load cycles. The derived relationship has been applied after normalization to estimate fatigue life as based on results of experimental examination of specimens made from titanium alloy.

The nomenclature of the aeronautical engineering is used throughout the paper due to the assumption that the component exposed to tests represents a part of an aircraft. This, in turn, has been intended to show some specific application(s) of the formulated model.
Właściwości Dynamiczne Linii Hydraulicznych Lotniczych Napędów Hydraulicznych
Authors: Ułanowicz Leszek
Published: March 2009

Właściwości Dynamiczne Linii Hydraulicznych Lotniczych Napędów Hydraulicznych

W artykule zaprezentowano wyniki analiz własności dynamicznych linii hydraulicznej uwzględniających efekt bezwładności cieczy płynącej w przewodzie sztywnym, jak i giętkim, efekt ściśliwości tej cieczy i efekt tarcia lepkiego. W rozważaniach potraktowano linię hydrauliczną jako czwórnik o dwóch wejściach i dwóch wyjściach, charakteryzujący się określoną macierzą transmitancji. Główne rozważania przeprowadzono dla modelu o zmiennej rezystancji. Podano rozwiązanie ogólne w funkcji operatora Laplace'a oraz adaptację modelu linii hydraulicznej dla przepływu turbulentnego i przepływu przez przewód o sprężystych ściankach. Wprowadzając odpowiednie uproszczenia do modelu o zmiennej rezystancji otrzymano kolejno model o stałej rezystancji i model linii bez strat.
Dynamic Properties of Hydraulic Lines for Fluid Power Transmission
Authors: Ułanowicz Leszek
Published: March 2009

Dynamic Properties of Hydraulic Lines for Fluid Power Transmission

This paper presents the results of a hydraulic line dynamic properties analysis taking into account inertia of the fluid flowing in rigid and flexible lines, the compressibility effect for this fluid and the viscous friction effect. The following are described and analyzed: solution of the wave equation in the form binding four variables: pressure and flow rate at the line input, and pressure and flow rate and the line output; two of the above-mentioned variables should be regarded as independent (input) and the other two as dependent (output), the accuracy comparison of distributed parameters model to lumped parameters model with regard to applicability range in hydraulic systems analysis, pressure value at given installation points as a response to rapid valve closing (transient response) or to valve opening (fluid hammer effect). In these considerations the hydraulic line is regarded as a two-port with two inputs and two outputs with a definite transmittance matrix. Main considerations concern the variable resistance model. A general solution is given as a function of the Laplace operator. Adaptation of the hydraulic line model to the turbulent flow and to the flow through a line with elastic boundaries is given. Introducing appropriate simplifications into the variable resistance model, the constant resistance model and lossless line model is obtained.

Also, general solutions for three different lump parameter models are presented. Accuracy of individual methods are compared with examples for selected systems.
Model Neuronowy Ekstraktora Obrazów Sygnałów Radiolokacyjnych
Authors: Krukar Wojciech , Niedziela Tadeusz
Published: March 2009

Model Neuronowy Ekstraktora Obrazów Sygnałów Radiolokacyjnych

Przeprowadzono badania symulacyjne programowego modelu ekstraktora neuronowego, który realizuje detekcję obiektu oraz określa jego położenie na tle szumu. Do symulacji sygnału radiolokacyjnego użyty został model sygnału, który jest sumą dwóch niezależnych procesów: sygnału odbitego od obiektu oraz szumu. Model ten uwzględnia impulsowe sondowanie, charakterystykę promieniowania obracającej się anteny, fluktuację powierzchni skutecznej obiektu oraz dopplerowskie przesunięcie częstotliwości nośnej. Do badań porównawczych przyjęto model ekstraktora powierzchniowego oraz powierzchniowo-amplitudowego. W wyniku zebranych doświadczeń podczas pracy projektowej do zadań postawionych ekstraktorowi neuronowemu najlepszą strukturą sieci okazała się trójwarstwowa sieć uczona metodą wstecznej propagacji błędu, posiadająca dwie warstwy ukryte, z tangensoidalną funkcją aktywacji oraz ruchomym progiem.
Actual Pathogen Detection: Sensors and Algorithms - a Review
Authors: Hahn Federico
Published: March 2009

Pathogens feed on fruits and vegetables causing great food losses or at least reduction of their shelf life. These pathogens can cause losses of the final product or in the farms were the products are grown, attacking leaves, stems and trees. This review analyses disease detection sensors and algorithms for both the farm and postharvest management of fruit and vegetable quality. Mango, avocado, apple, tomato, potato, citrus and grapes were selected as the fruits and vegetables for study due to their world-wide consumption. Disease warning systems for predicting pathogens and insects on farms during fruit and vegetable production are commonly used for all the crops and are available where meteorological stations are present. It can be seen that these disease risk systems are being slowly replaced by remote sensing monitoring in developed countries. Satellite images have reduced their temporal resolution, but are expensive and must become cheaper for their use world-wide. In the last 30 years, a lot of research has been carried out in non-destructive sensors for food quality. Actually, non-destructive technology has been applied for sorting high quality fruit which is desired by the consumer. The sensors require algorithms to work properly; the most used being discriminant analysis and training neural networks. New algorithms will be required due to the high quantity of data acquired and its processing, and for disease warning strategies for disease detection.
Antioxidant Activity and Phenolic Content of Paederia foetida and Syzygium aqueum
Authors: Osman Hasnah , Rahim Afidah  A. , Isa Norhafizah  M. , Bakhir Nornaemah  M.
Published: March 2009

The antioxidant activity of fresh and dried plant extracts of Paederia foetida and Syzygium aqueum were studied using β-carotene bleaching and the 2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The percentage of antioxidant activity for all extract samples using both assays was between 58 and 80%. The fresh samples of both plants had higher antioxidant activity than the dried samples. The results of the β-carotene bleaching assay were correlated (R2 = 0.9849) with those of the ABTS assay.
Brominated Thiophenes as Precursors in the Preparation of Brominated and Arylated Anthraquinones
Authors: Thiemann Thies , Tanaka Yasuko , Iniesta Jesus
Published: March 2009

Brominated anthraquinones can be synthesized directly from bromothiophenes when these are reacted with 1,4-naphthoquinones in the presence of meta-chloroperoxybenzoic acid. The bromoanthraquinones are versatile building blocks in the preparation of arylated anthraquinones and of extended π-systems with interspersed anthraquinone units.
Sink-oriented Dynamic Location Service Protocol for Mobile Sinks with an Energy Efficient Grid-Based Approach
Authors: Jeon Hyeonjae , Park Kwangjin , Hwang Dae-Joon , Choo Hyunseung
Published: March 2009

Sensor nodes transmit the sensed information to the sink through wireless sensor networks (WSNs). They have limited power, computational capacities and memory. Portable wireless devices are increasing in popularity. Mechanisms that allow information to be efficiently obtained through mobile WSNs are of significant interest. However, a mobile sink introduces many challenges to data dissemination in large WSNs. For example, it is important to efficiently identify the locations of mobile sinks and disseminate information from multi-source nodes to the multi-mobile sinks. In particular, a stationary dissemination path may no longer be effective in mobile sink applications, due to sink mobility. In this paper, we propose a Sink-oriented Dynamic Location Service (SDLS) approach to handle sink mobility. In SDLS, we propose an Eight-Direction Anchor (EDA) system that acts as a location service server. EDA prevents intensive energy consumption at the border sensor nodes and thus provides energy balancing to all the sensor nodes. Then we propose a Location-based Shortest Relay (LSR) that efficiently forwards (or relays) data from a source node to a sink with minimal delay path. Our results demonstrate that SDLS not only provides an efficient and scalable location service, but also reduces the average data communication overhead in scenarios with multiple and moving sinks and sources.
Waveform Analysis of UWB GPR Antennas
Authors: Rial Fernando I. , Lorenzo Henrique , Pereira Manuel , Armesto Julia
Published: March 2009

Ground Penetrating Radar (GPR) systems fall into the category of ultra-wideband (UWB) devices. Most GPR equipment covers a frequency range between an octave and a decade by using short-time pulses. Each signal recorded by a GPR gathers a temporal log of attenuated and distorted versions of these pulses (due to the effect of the propagation medium) plus possible electromagnetic interferences and noise. In order to make a good interpretation of this data and extract the most possible information during processing, a deep knowledge of the wavelet emitted by the antennas is essential. Moreover, some advanced processing techniques require specific knowledge of this signal to obtain satisfactory results. In this work, we carried out a series of tests in order to determine the source wavelet emitted by a ground-coupled antenna with a 500 MHz central frequency.
Identification of Earthquake Induced Damage Areas Using Fourier Transform and SPOT HRVIR Pan Images
Authors: Sertel Elif
Published: March 2009

A devastating earthquake with a magnitude of Mw 7.4 occurred on the North Anatolian Fault Zone (NAFZ) of Turkey on August 17, 1999 at 00:01:39 UTC (3:01 a.m. local time). The aim of this study is to propose a new approach to automatically identify earthquake induced damage areas which can provide valuable information to support emergency response and recovery assessment procedures. This research was conducted in the Adapazari inner city, covering a 3 × 3 km area, where 11,373 buildings collapsed as a result of the earthquake. SPOT high resolution visible infrared (HRVIR) Pan images obtained before (25 June 1999) and after (4 October 1999) the earthquake were used in the study. Five steps were employed to conduct the research and these are: (i) geometric and radiometric correction of satellite images, (ii) Fast Fourier Transform (FFT) of pre- and post-earthquake images and filtering the images in frequency domain, (iii) generating difference image using Inverse Fast Fourier Transform (IFFT) pre- and post- earthquake images, (iv) application of level slicing to difference image to identify the earthquake-induced damages, (v) accuracy assessment of the method using ground truth obtained from a 1/5,000 scale damage map. The total accuracy obtained in the research is 80.19 %, illustrating that the proposed method can be successfully used to automatically identify earthquake-induced damage areas.
Detection of Activities by Wireless Sensors for Daily Life Surveillance: Eating and Drinking
Authors: Zhang Sen , Ang Marcelo H. , Xiao Wendong , Tham Chen Khong
Published: March 2009

This paper introduces a two-stage approach to the detection of people eating and/or drinking for the purposes of surveillance of daily life. With the sole use of wearable accelerometer sensor attached to somebody’s (man or a woman) wrists, this two-stage approach consists of feature extraction followed by classification. At the first stage, based on the limb’s three dimensional kinematics movement model and the Extended Kalman Filter (EKF), the realtime arm movement features described by Euler angles are extracted from the raw accelerometer measurement data. In the latter stage, the Hierarchical Temporal Memory (HTM) network is adopted to classify the extracted features of the eating/drinking activities based on the space and time varying property of the features, by making use of the powerful modelling capability of HTM network on dynamic signals which is varying with both space and time. The proposed approach is tested through the real eating and drinking activities using the three dimensional accelerometers. Experimental results show that the EKF and HTM based two-stage approach can perform the activity detection successfully with very high accuracy.
Sustainability: A Crucial Quest for Humanity - Welcome to a New Open Access Journal for a Growing Multidisciplinary Community
Authors: Rosen Marc A.
Published: March 2009

Sustainability, although often hard to define precisely, is a rapidly growing area of study that is becoming increasingly applied in diverse areas. The definition put forth in 1983 by the World Commission on Environment and Development, informally known as the Brundtland Commission, captures many aspects of the topic. That commission defined sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Other attempts have been made to define what we mean when we refer to sustainability or strive to achieve it as an objective. Despite the differences in definitions, a key theme that emerges is that sustainability is a concept that needs to be incorporated in many if not all of the activities that people undertake. [...]
Semiconducting Thienothiophene Copolymers: Design, Synthesis, Morphology, and Performance in Thin‐Film Organic Transistors
Authors: McCulloch Iain , Heeney Martin , Chabinyc Michael L. , DeLongchamp Dean , Kline R. Joseph , Cölle Michael , Duffy Warren , Fischer Daniel , Gundlach David , Hamadani Behrang , Hamilton Rick , Richter Lee , Salleo Alberto , Shkunov Maxim , Sparrowe David , Tierney Steven , Zhang Weimin
Published: March 2009

Organic semiconductors are emerging as a viable alternative to amorphous silicon in a range of thin‐film transistor devices. With the possibility to formulate these p‐type materials as inks and subsequently print into patterned devices, organic‐based transistors offer significant commercial advantages for manufacture, with initial applications such as low performance displays and simple logic being envisaged. Previous limitations of both air stability and electrical performance are now being overcome with a range of both small molecule and polymer‐based solution‐processable materials, which achieve charge carrier mobilities in excess of 0.5 cm2 V−1 s−1, a benchmark value for amorphous silicon semiconductors. Polymer semiconductors based on thienothiophene copolymers have achieved amongst the highest charge carrier mobilities in solution‐processed transistor devices. In this Progress Report, we evaluate the advances and limitations of this class of polymer in transistor devices.
Nanostructured Organic–Inorganic Composite Materials by Twin Polymerization of Hybrid Monomers
Authors: Spange Stefan , Grund Silke
Published: March 2009

Forming two structurally different but associated polymer structures in a single step is a possible route for the production of nanostructured materials. By means of twin polymerization of specially constructed monomers consisting of two different covalently bonded building blocks (hybrid monomers), this route is realized. What is important is that two different macromolecular structures are formed from one monomer in a single process. The two polymers formed can be linear, branched, or cross‐linked structures. The molecular composition of the hybrid monomer defines the degree of cross‐linking of the corresponding macromolecular structures that is theoretically possible.
Enantioselective Reduction of Diaryl Ketones Catalyzed by a Carbonyl Reductase from Sporobolomyces salmonicolor and its Mutant Enzymes
Authors: Li Hongmei , Zhu Dunming , Hua Ling , Biehl Edward R.
Published: March 2009

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The carbonyl reductase from red yeast Sporobolomyces salmonicolor AKU4429 (SSCR) and its mutant enzymes effectively catalyzed the enantioselective reduction of diaryl ketones to give the corresponding chiral alcohols. Both conversion and enantioselectivity were dependent on the co‐solvent in the reaction medium. Diaryl ketones with a para‐substituent on one of the phenyl groups were reduced with high enantioselectivity (up to 99% ee), which is difficult to achieve using chemical methods such as chiral borane reduction, asymmetric hydrogenation or hydrosilylation. Mutation of SSCR at Q245 resulted in a higher amount of (S)‐enantiomer in the products, and in the case of mutant Q245P with para‐substituted diaryl ketones as substrate, this effect was so remarkable that the reduction enantiopreference was switched from (R) to (S). The present study provides valuable information about the catalytic properties of the carbonyl reductase SSCR toward the reduction of diaryl ketones, serving as basis for further engineering of this enzyme to develop efficient biocatalysts for highly enantiospecific reduction of diaryl ketones without high electronic dissymmetry or an ortho‐substituent on one of the aryl groups.
Interfacing Glycosylated Carbon‐Nanotube‐Network Devices with Living Cells to Detect Dynamic Secretion of Biomolecules
Authors: Sudibya Herry Gunadi , Ma Jimei , Dong Xiaochen , Ng Simon , Li Lain‐Jong , Liu Xue‐Wei , Chen Peng
Published: March 2009

Sanfte Zellanalytik: Zum Einsatz als Biosensoren wurden einwandige Kohlenstoffnanoröhren (SWNTs) mit bioaktiven Monosacchariden funktionalisiert. Ein bioverträgliches glycosyliertes Netzwerk aus Nanoröhren kann lebende Zellen anlagern (siehe Schema) und die Ausschüttung von Biomolekülen auf elektronischem Weg mit hoher zeitlicher Präzision und Empfindlichkeit wiedergeben.

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Symmetry versus Minimal Pentagonal Adjacencies in Uranium‐Based Polyoxometalate Fullerene Topologies
Authors: Sigmon Ginger E. , Unruh Daniel K. , Ling Jie , Weaver Brittany , Ward Matthew , Pressprich Laura , Simonetti Antonio , Burns Peter C.
Published: March 2009

Wahl der Nachbarn: Cluster mit 60, 44 und 36 Uranylperoxidhydroxid‐Polyedern (siehe Bild) nehmen Fullerentopologien von maximaler Symmetrie an. Der größte Cluster, U60, ist topologisch identisch mit C60 (keine benachbarten Fünfecke, höchstmögliche Symmetrie). U44 hat eine Topologie mit maximaler Symmetrie anstelle einer Topologie mit der niedrigsten Zahl benachbarter Fünfecke.

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Presence of Galanin‐Like Immunoreactivity in Mesenchymal and Neural Crest Origin Tissues During Embryonic Development in the Mouse
Authors: Jones Melissa , Perumal Paul , Vrontakis Maria
Published: March 2009

Galanin is a highly conserved neuropeptide with a wide range of biological effects. Recently, through transcriptome analysis, galanin was identified in undifferentiated mouse embryonic stem cells as one of the most abundant transcripts. We have examined the developmental expression of galanin‐like immunoreactivity in mice from embryonic day 10 (E10) to embryonic day 15 (E15). At E10, galanin was readily detected in the undifferentiated head and trunk mesenchyme of both mesodermal and neural crest origin. There was also strong immunoreactivity in the mesenchymal spiral ridges of the outflow tract of the heart and the endocardial cushions. The highest level of galanin detected was at E13 in the craniofacial mesenchyme and proliferating chondrocytes in bones of both neural crest and mesoderm origin. Dorsal root ganglia and trigeminal ganglia contained galanin immunoreactive cells as well. These data indicate the presence of galanin peptide during periods of morphogenesis and thus a developmental role for the peptide in mesenchymal and neural crest origin tissues in the mouse embryo. Whether galanin has a growth and/or differentiating role, still remains to be demonstrated. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Protein feeds coproduction in biomass conversion to fuels and chemicals
Authors: Dale Bruce E. , Allen Michael S. , Laser Mark , Lynd Lee R.
Published: March 2009

Agriculture has changed greatly in the past in response to changing human needs. Now agriculture is being called on to provide raw materials for very large‐scale fuel and chemical production. Agriculture will change again in response to this demand and all producers and users of agricultural feedstocks will be affected by this change. For example, livestock feeding practices have already changed in response to the availability of distillers' grains from corn ethanol production. A fuels industry based on herbaceous biomass energy crops will be many‐fold larger than the existing corn ethanol industry and will produce its own set of impacts on livestock feeding. We explore here one of these impacts: the availability of large new sources of feed protein from biomass energy crops.

In addition to structural carbohydrates, such as cellulose and hemicellulose, herbaceous biomass energy crops can easily be produced with approximately 10% protein, called ‘leaf protein’. This leaf protein, as exemplified by alfalfa leaf protein, is superior to soybean meal (SBM) protein in its biological value. Leaf protein recovery and processing fit well into many process flow diagrams for biomass fuels. When leaf protein is properly processed to concentrate it and remove antinutritional factors, as we have learned over the years to do with soybean meal protein, protein in leaf protein concentrate (LPC) will probably be at least as valuable in livestock diets as SBM protein.

If LPC is used to meet 20% of total animal protein requirements (i.e., market penetration of 20%) then the potential utilization of leaf protein concentrate could reach as much as 24 million metric tons annually. This leaf protein will replace protein from SBM and other sources. This much leaf protein will reduce by approximately 16 million hectares the amount of land required to provide protein for livestock. Likewise the amount of land required to meet fuel needs will effectively be reduced by 8 million hectares because this land will effectively do ‘double duty’ by producing needed animal protein as well as feedstocks for fuel production. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
Coproduction of ethanol and power from switchgrass
Authors: Laser Mark , Jin Haiming , Jayawardhana Kemantha , Lynd Lee R.
Published: March 2009

Three process designs for producing ethanol and electricity from switchgrass are evaluated: a base‐case technology scenario involving dilute acid pre‐treatment and simultaneous saccharification and fermentation, and two mature technology scenarios incorporating ammonia fiber expansion pre‐treatment and consolidated bioprocessing – one with conventional Rankine power coproduction, and one coproducing power via a gas turbine combined cycle. Material and energy balances – resulting from detailed Aspen Plus models – are reported and used to estimate processing costs and perform discounted cash flow analysis to assess plant profitability. The mature technology —designs significantly improve both process efficiency and cost relative to base‐case cellulosic ethanol technology, with the resulting fossil fuel displacement being decidedly positive and production costs competitive with gasoline, even at relatively low prices. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
Comparison of the structural and functional properties of RNase A and BS‐RNase: A stepwise mutagenesis approach
Authors: Ercole Carmine , Colamarino Rosa Angela , Pizzo Elio , Fogolari Federico , Spadaccini Roberta , Picone Delia
Published: March 2009

The original structure of bovine seminal ribonuclease (BS‐RNase), solved in 1993, represents a milestone in the story of protein structure, because it represented the first X‐ray structure showing two polypeptide chains entangled through their terminal regions. It is generally assumed that this structural feature is the basis of several special biological activities, including a potent antitumor activity, but this has not been yet definitely proved. To assess this hypothesis, in this article we have analyzed the effects of the N‐terminal hinge region and/or of Arg80 on the swapping propensity and cytotoxicity in newly designed proteins, using a covalent dimeric variant of bovine pancreatic ribonuclease (RNase A) as scaffold. All the proteins have a very poor cytotoxic activity, independently on the swapping propensity, that can even reach the same value of native BS‐RNase. Overall our data suggest that the swapping represents still an essential requisite for the cytotoxic activity, because it keeps the dimeric structure stable even in the reducing cytosolic environment, but other features are essential to design dimeric antitumor ribonucleases, including a strong positive potential at the N‐terminal face and a quaternary structure able to evade the cytosolic ribonuclease inhibitor, with or without the interchain disulfide bridges. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1009–1017, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Terminal sidechain packing of a designed β‐hairpin influences conformation and stability
Authors: Eidenschink Lisa , Crabbe Edward , Andersen Niels H.
Published: March 2009

While end capping in α‐helices is well understood, the concept of capping a β‐hairpin is a relatively recent development; to date, favorable Coulombic interactions are the only example of sidechains at the termini influencing the overall stability of a β‐hairpin. While cross‐strand hydrophobic residues generally provide hairpin stabilization, particular when flanking the turn region, those remote from this location appear to provide little stabilization. While probing for an optimal residue at a hydrogen bond position near the terminus of a designed β‐hairpin a conservative, hydrophobic, V → I mutation was observed to not only result in a significant change in fold population but also effected major changes in the structuring shifts at numerous sites in the peptide. Mutational studies reveal that there is an interaction between the sidechain at this H‐bonded site and the sidechain at the C‐terminal non‐H‐bonded site of the hairpin. This interaction, which appears to be hydrophobic in character, requires a highly twisted hairpin structure. Modifications at the C‐terminal site, for example an E → A mutation (ΔΔGU = 6 kJ/mol), have profound affects on fold structure and stability. The data suggests that this may be a case of hairpin end capping by the formation of a hydrophobic cluster. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 557–564, 2009.

This article was originally published online as an accepted preprint. The “Published Online”date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Electrochemical and Conformational Consequences of Copper (CuI and CuII) Binding to β‐Amyloid(1–40)
Authors: Brzyska Maria , Trzesniewska Katarzyna , Wieckowska Agnieszka , Szczepankiewicz Andrzej , Elbaum Danek
Published: March 2009

Copper‐induced structural rearrangements of Aβ40 structure and its redox properties are described in this study. Electrochemical and fluorescent methods are used to characterise the behaviour of Aβ–Cu species. The data suggest that time‐dependent folding of Aβ–Cu species may cause changes in the redox potentials.

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Extracellular deposits of β‐amyloid (Aβ) into senile plaques are the major features observed in brains of Alzheimer's disease (AD) patients. A high concentration of copper has been associated with insoluble amyloid plaques. It is known that Aβ(1–40) can bind copper with high affinity, but electrochemical properties of Aβ(1–40)–Cu complexes are not well‐characterised. In this study we demonstrate that complexation of copper (both as CuI and CuII) by Aβ(1–40) reduces the metal electrochemical activity. Formation of copper‐Aβ(1–40) complexes is associated with alteration of the redox potential. The data reveal significant redox activity of fresh Aβ–copper solutions. However, copper‐induced structural rearrangements of the peptide, documented by CD, correspond with time‐dependent changes of formal reduction potentials (E0′) of the complex. Fluorescent and electrochemical (cyclic voltammetry and differential pulse voltammetry) techniques suggest that reduction of the redox activity by Aβ–Cu complexes could be attributed to conformational changes that diminished copper accessibility to the external environment. According to our evidence, conformational rearrangements, induced by copper binding to amyloid, elongate the time necessary to attain the same β‐sheet content as for the metal‐free peptide. Although the redox activity of Aβ–Cu complexes diminishes in a time‐dependent manner, they are not completely devoid of toxicity as they destabilize red blood cells osmotic fragility, even after prolonged incubation.
Enantioselective Synthesis of 2‐Isoxazolines by a One‐Flask Conjugate Addition/Oxime‐Transfer Process
Authors: Pohjakallio Antti , Pihko Petri M.
Published: March 2009

Enantioselective isoxazoline synthesis: A combination of 1) a catalytic enantioselective conjugate addition of oximes to α,β‐unsaturated aldehydes and 2) an acid‐catalyzed intramolecular oxime‐transfer reaction lead to the first asymmetric synthesis of 3‐unsubstituted 2‐isoxazolines (see scheme).

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Cellular expression of Midkine‐a and Midkine‐b during retinal development and photoreceptor regeneration in zebrafish
Authors: Calinescu Anda‐Alexandra , Vihtelic Thomas S. , Hyde David R. , Hitchcock Peter F.
Published: March 2009

In the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult Müller glia. Recently, Müller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine‐b (mdkb). Midkine is a highly conserved heparin‐binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors, and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are coexpressed in horizontal cells and proliferating Müller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration. J. Comp. Neurol. 514:1–10, 2009. © 2009 Wiley‐Liss, Inc.
One‐Pot, Selective Hydroformylation, Condensation, and Hydrogenation Processes by a Sol–Gel Entrapped Rhodium Complex, an Immobilized Base, and an Ionic Liquid
Authors: Hamza Khalil , Schumann Herbert , Blum Jochanan
Published: March 2009

We report on a one‐pot, multistep process in which styrene derivatives are selectively hydroformylated to give branched aldehydes, which in turn, are condensed with reactive methylene compounds (malononitrile, ethyl cyanoacetate), and then hydrogenated. The process takes place at 80 °C under 20.7 bar H2 and 20.7 bar CO in the presence of [Rh(cod)Cl]2 and Na[Ph2P‐3‐(C6H4SO3)], which have been co‐entrapped within ionic liquid confined silica sol–gel together with a separately encaged base. The catalyst can be reused at least four times, but the base has to be renewed after each run. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Prejudice in the police: On the processes underlying the effects of selection and group socialisation
Authors: Gatto Juliette , Dambrun Michaël , Kerbrat Christian , De Oliveira Pierre
Published: March 2009

The principal aim of this study is to determine why police officers are generally found to be more prejudiced towards disadvantaged groups than are the standard population. Two independent processes were expected to account for this effect: Selection and group socialisation. Using a cross‐sectional design (N = 170), firstly, we compared, newly recruited police officers with a control population (selection effect), and secondly, police officers with 1 year of training with the newly recruited ones (group socialisation effect). Results reveal a significant effect of both selection and group socialisation, the two being underlined by distinct processes; right‐wing authoritarianism (RWA) in the case of the former and internalisation of a prejudice norm in the case of the latter. Finally, the results show that group identification moderates the change in internalisation of the prejudice norm. Copyright © 2009 John Wiley & Sons, Ltd.
Adjustments in channel form, sediment calibre and vegetation around check‐dams in the headwater reaches of mountain torrents, Calabria, Italy
Authors: Bombino G. , Gurnell A. M. , Tamburino V. , Zema D. A. , Zimbone S. M.
Published: March 2009

The structure and dynamics of vegetation in valley bottoms are both strongly associated with fluvial processes and landform dynamics. All of these associations are disrupted by the installation of engineering control works. We use survey and analysis methods developed previously to investigate the impact of the installation of check‐dams within the confined headwaters of steep seasonally‐flowing streams (fiumaras) in Calabria, southern Italy, on active channel form, sediment calibre, and the richness, cover and development of riparian vegetation. Based on detailed field measurements along transects across the active channel, estimates of indices of vegetation extent (GCC), development (WCH) and their cross‐sectional variability (coefficients of variation of both indices at each survey site CVGCC, CVWCH), the number of species present (Ns), channel shape (w/d – the width/depth ratio), cross‐sectional area (CSA), downstream gradient (slope), surface bed sediment calibre (D50) and subsurface fine sediment content (percentage less than 250 µm by weight) were obtained for 60 transects located immediately upstream (U), downstream (D) and at intermediate sites (I) around 20 check‐dams located in four different headwater catchments. Analysis of this data set suggests that statistically significant changes in channel form and sediment calibre upstream of check‐dams are associated with more consistent vegetation development across the active channel, including an increase in species richness relative to other transects, but notable increases in vegetation cover and development only arise where the physical characteristics of the channel are notably different from intermediate and downstream channels. Because of the naturally steep profile of the study torrents, intermediate sections between check‐dams tend to be more similar in form to channels located immediately downstream of check‐dams than those located upstream, leading to similar structural properties in the riparian vegetation. The intermediate transects support considerably more species than downstream reaches, but the conditions upstream of the check‐dams appear to be so favourable for riparian vegetation development that species richness exceeds that found in intermediate reaches. Despite the confined headwater locations, these contrasts in form, sediment and vegetation development around check‐dams are strong and consistent across the study catchments, over‐riding more subtle contrasts in species richness and sediment calibre between catchments. Copyright © 2009 John Wiley & Sons, Ltd.
Novel terpenyl esters from Australian finger lime (Citrus australasica) peel extract
Authors: Delort Estelle , Jaquier Alain
Published: March 2009

The volatile constituents of the peel solvent extract of the Australian finger lime Citrus australasica were analysed by GC–MS. Besides limonene, isomenthone was a major component, which is rare in Citrus species. Six new terpenyl esters were also identified and confirmed by chemical synthesis: citronellyl 2‐methylbutanoate; 1,8(10)‐p‐menthadien‐9‐yl propanoate; 1,8(10)‐p‐menthadien‐9‐yl 2‐methylbutanoate; 1,8(10)‐p‐menthadien‐9‐yl 3‐methylbutanoate; 1‐p‐menthen‐9‐yl 2‐methylbutanoate; and 1‐p‐menthen‐9‐yl 3‐methylbutanoate. To the best of our knowledge, the last four compounds have never before been identified in a natural product extract. Copyright © 2009 John Wiley & Sons, Ltd.