bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethics and E-Business
Authors: Waddell Dianne
Published: April 2011

This chapter attempts to give an outline of some of the contemporary ethical issues related to technological innovation associated with e-business, in particular the notion that e-business and ethics is an oxymoron (‘a figure of speech … seeming self-contradiction’). The question is, has innovation in e-business resulted in unethical behaviour because of the new media and technology and the fact that businesses are embarking on something new therefore the old rules do not apply? Is it easier to behave unethically over the net? The author reviews the various methods used for dealing with on-line security and investigates the notion of trust which is implied in on-line transactions and business dealings. Also typical e-business ethical dilemmas are proffered as a catalyst for further debate. The author concludes that as e-businesses deal with intangible products and services over the Internet, the potential for ethical dilemmas and shonky practices to develop is far higher than a bricks-and-mortar business. The challenge is for e-businesses to establish trust based on consistent good ethical practice and an industry approach to abusers of the system. Ethics and innovation are not mutually exclusive and will continue to challenge e-businesses.
Factors Influencing E-Commerce Adoption in Small to Medium Businesses
Authors: Lertwongsatien Chalermsak , Wongpinunwatana Nitaya , Achakulwisut Angsana
Published: April 2011

This study examines the factors influencing the variations of e-commerce adoption decisions in small and medium businesses in Thailand. Based on the literature review, three groups of factors are identified, including organizational, technology, and environmental factors. Firms are classified into three main groups based on the extent to which an organization is relatively earlier to adopt e-commerce than others, namely adopters, prospectors, and laggards. Data was collected through a national survey in several provinces in Thailand. The statistical analysis results strongly support the hypotheses. The results are interpreted and the implications of this study are subsequently discussed.
Mapping the Diffusion of the Internet Technology Cluster
Authors: Griffin James
Published: April 2011

This chapter adopts a ‘technology cluster’ perspective in examining Internet usage within SMEs, analyzing Internet usage in terms of three distinct Internet technology groupings. Specific attention is paid to identifying and categorizing the diffusion pattern of website development among the SME sector on the basis of the theory of mimetic IT adoption patterns. Two potential hybrid diffusion patterns are identified, and their implications for policy makers and development agencies in the SME sector are discussed.
Mass Customization and Product Models
Authors: Svensson Carsten , Malis Martin
Published: April 2011

When dealing with complex product models, efficient knowledge distribution is essential to obtain success. This chapter describes how product models can be applied to support the knowledge distribution. The change toward individualization will radically affect the knowledge application in relation to the product. Through the application of a mass customization strategy, companies have a unique opportunity to create increased customer satisfaction. In a customized production, knowledge and information have to be easily accessible since every product is a unique combination of information. If the dream of a customized alternative instead of a uniform mass-produced product shall become a reality, then the cross-organizational efficiency must be kept at a competitive level. This is the real challenge for mass customization. A radical restructuring of both the internal and the external knowledge management systems is needed. Management of variety and closer integration with suppliers is necessary when the companies are working in a network.
E-Transformation of Austrain SMEs
Authors: Auer Christoph
Published: April 2011

This chapter highlights the differences that exist between the e-commerce (EC) perspective of SMEs and the EC perspective from the researchers’ point of view. First the main aspects of SME EC found in a literature review are pointed out and then the results of a SME survey are presented. The findings of this survey, conducted with Austrian SMEs in the automotive industry sector, show for example that EC adoption is slower than expected. Consequently, we introduce a concept that was developed to minimize the identified gap between the two EC perspectives, by connecting university research and regional SME networks more efficiently. This action research-based approach enables SMEs to evaluate the impact of EC on their business model.
Moyamoya syndrome in an adult with essential thrombocythemia
Authors: Lazzaro Marc , Cochran Elizabeth J. , Lopes Demetrius K. , Prabhakaran Shyam
Published: April 2011

Moyamoya syndrome is a rare cerebrovascular disorder characterized by progressive occlusion of the supraclinoid internal carotid artery and proximal portions of the anterior and middle cerebral arteries resulting in an extensive network of collateralized blood vessels and producing a characteristic angiographic appearance. Although the pathophysiology is unclear, hematologic disorders have been associated with development of the moyamoya syndrome. A case report is presented. A 29 year-old female with a history of essential thrombocythemia developed progressive ischemic strokes. Angiography revealed characteristic moyamoya changes and pathologic examination showed intimal hyperplasia with scant collagen fibers and myxoid change. This is the first reported case of moyamoya syndrome in an adult patient with essential thrombocythemia demonstrating histological findings that suggest a shared pathophysiology with moyamoya syndrome in sickle cell anemia.
Anal Cancer debuting as Cancer of Unknown Primary
Authors: Sveistrup Joen , Loft Annika , Engelholm Svend Aage
Published: April 2011

Anal cancer usually presents with a visible or palpable tumour. In this case we describe a 54-year old man diagnosed with Cancer of Unknown Primary (CUP) with a single inguinal node as the only finding. Thorough examination failed to identify any primary tumour. The patient was treated with lymph node dissection and not until nearly two years after initial diagnosis, was the primary tumour found, and the patient was diagnosed with anal cancer. The patient was treated with chemoradiotherapy and 45 months after initial diagnosis there is still no sign of relapse. This case illustrates, that anal cancer can metastasise before the primary tumour is detectable. Furthermore, it demonstrates the necessity of thorough clinical follow-up after treatment of CUP since the primary tumour was found later. Finally this is a case of a long-term survivor following treatment for metastatic inguinal lymph nodes from an initially unknown primary cancer.
Modeling Magma Dynamics with a Mixed Fourier Collocation — Discontinuous Galerkin Method
Authors: Schiemenz Alan R. , Hesse Marc A. , Hesthaven Jan S.
Published: April 2011

A high-order discretization consisting of a tensor product of the Fourier collocation and discontinuous Galerkin methods is presented for numerical modeling of magma dynamics. The physical model is an advection-reaction type system consisting of two hyperbolic equations and one elliptic equation. The high-order solution basis allows for accurate and efficient representation of compaction-dissolution waves that are predicted from linear theory. The discontinuous Galerkin method provides a robust and efficient solution to the eigenvalue problem formed by linear stability analysis of the physical system. New insights into the processes of melt generation and segregation, such as melt channel bifurcation, are revealed from two-dimensional time-dependent simulations.
Semiclassical Lattice Boltzmann Simulations of Rarefied Circular Pipe Flows
Authors: Yang Jaw-Yen , Hung Li-Hsin , Kuo Yao-Tien
Published: April 2011

Computations of microscopic circular pipe flow in a rarefied quantum gas are presented using a semiclassical axisymmetric lattice Boltzmann method. The method is first derived by directly projecting the Uehling-Uhlenbeck Boltzmann-BGK equations in two-dimensional rectangular coordinates onto the tensor Hermite polynomials using moment expansion method and then the forcing strategy of Halliday et al. [Phys. Rev. E., 64 (2001), 011208] is adopted by adding forcing terms into the resulting microdynamic evolution equation. The determination of the forcing terms is dictated by yielding the emergent macroscopic equations toward a particular target form. The correct macroscopic equations of the incompressible axisymmetric viscous flows are recovered through the Chapman-Enskog expansion. The velocity profiles and the mass flow rates of pipe flows with several Knudsen numbers covering different flow regimes are presented. It is found the Knudsen minimum can be captured in all three statistics studied. The results also indicate distinct characteristics of the effects of quantum statistics.
Finite Volume Evolution Galerkin Methods for the Shallow Water Equations with Dry Beds
Authors: Bollermann Andreas , Noelle Sebastian , Lukáčová-Medvid’ová Maria
Published: April 2011

We present a new Finite Volume Evolution Galerkin (FVEG) scheme for the solution of the shallow water equations (SWE) with the bottom topography as a source term. Our new scheme will be based on the FVEG methods presented in (Noelle and Kraft, J. Comp. Phys., 221 (2007)), but adds the possibility to handle dry boundaries. The most important aspect is to preserve the positivity of the water height. We present a general approach to ensure this for arbitrary finite volume schemes. The main idea is to limit the outgoing fluxes of a cell whenever they would create negative water height. Physically, this corresponds to the absence of fluxes in the presence of vacuum. Wellbalancing is then re-established by splitting gravitational and gravity driven parts of the flux. Moreover, a new entropy fix is introduced that improves the reproduction of sonic rarefaction waves.
Cosmic rays, aerosol formation and cloud-condensation nuclei: sensitivities to model uncertainties
Authors: Snow-Kropla E. J. , Pierce J. R. , Westervelt D. M. , Trivitayanurak W.
Published: April 2011

Abstract. The flux of cosmic rays to the atmosphere has been reported to correlate with cloud and aerosol properties. One proposed mechanism for these correlations is the "ion-aerosol clear-air" mechanism where the cosmic rays modulate atmospheric ion concentrations, ion-induced nucleation of aerosols and cloud condensation nuclei (CCN) concentrations. We use a global chemical transport model with online aerosol microphysics to explore the dependence of CCN concentrations on the cosmic-ray flux. Expanding upon previous work, we test the sensitivity of the cosmic-ray/CCN connection to several uncertain parameters in the model including primary emissions, Secondary Organic Aerosol (SOA) condensation and charge-enhanced condensational growth. The sensitivity of CCN to cosmic rays increases when simulations are run with decreased primary emissions, but show location-dependent behavior from increased amounts of secondary organic aerosol and charge-enhanced growth. For all test cases, the change in the concentration of particles larger than 80 nm between solar minimum (high cosmic ray flux) and solar maximum (low cosmic ray flux) simulations is less than 0.2 %. The change in the total number of particles larger than 10 nm was larger, but always less than 1 %. The simulated change in the column-integrated Ångström exponent was negligible for all test cases. Additionally, we test the predicted aerosol sensitivity to week-long Forbush decreases of cosmic rays and find that the maximum change in aerosol properties for these cases is similar to steady-state aerosol differences between the solar maximum and solar minimum. These results provide evidence that the effect of cosmic rays on CCN and clouds through the ion-aerosol clear-sky mechanism is limited by dampening from aerosol processes.
Characteristics of immersion freezing nuclei at the South Pole station in Antarctica
Authors: Ardon-Dryer K. , Levin Z. , Lawson R. P.
Published: April 2011

Abstract. The effectiveness of aerosols as immersion freezing nuclei at the South Pole station was investigated during January and February 2009 using the FRIDGE-TAU. The analysis consisted of testing the freezing temperature of about 100–130 drops per sample containing aerosols collected at ground level and on a balloon lifted to different heights. All the drops froze between −18 °C and −27 °C. The temperature in which 50 % of the drops froze occurred at −24 °C, while nuclei concentration of 1 L−1 at −23 °C was calculated. Meteorological conditions such as wind speed, ice precipitation as well as the trajectories of the air masses affected the ice nuclei concentrations. Higher concentrations were observed on days when the winds were stronger or when the air mass originated from the sea.
EVAPORATION: a new vapor pressure estimation method for organic molecules including non-additivity and intramolecular interactions
Authors: Compernolle S. , Ceulemans K. , Müller J.-F.
Published: April 2011

Abstract. We present EVAPORATION (Estimation of VApour Pressure of ORganics, Accounting for Temperature, Intramolecular, and Non-additivity effects), a method to predict vapour pressure p0 of organic molecules needing only molecular structure as input. The method is applicable to zero-, mono- and polyfunctional molecules. A simple formula to describe log10p0(T) is employed, that takes into account both a wide temperature dependence and the non-additivity of functional groups. In order to match the recent data on functionalised diacids an empirical modification to the method was introduced. Contributions due to carbon skeleton, functional groups, and intramolecular interaction between groups are included. Molecules typically originating from oxidation of biogenic molecules are within the scope of this method: carbonyls, alcohols, ethers, esters, nitrates, acids, peroxides, hydroperoxides, peroxy acyl nitrates and peracids. Therefore the method is especially suited to describe compounds forming secondary organic aerosol (SOA).
A global analysis of satellite derived and DGVM surface soil moisture products
Authors: Rebel K. T. , de Jeu R. A. M. , Ciais P. , Viovy N. , Piao S. L. , Kiely G. , Dolman A. J.
Published: April 2011

Abstract. Soil moisture availability is important in regulating photosynthesis and controlling land surface-climate feedbacks at both the local and global scale. Recently, global remote-sensing datasets for soil moisture have become available. In this paper we assess the possibility of using remotely sensed soil moisture (AMSR-E) to evaluate the results of the process-based vegetation model ORCHIDEE during the period 2003–2004. We find that the soil moisture products of AMSR-E and ORCHIDEE correlate well, in particular when considering the root zone soil moisture of ORCHIDEE. However, the root zone soil moisture in ORCHIDEE consistently overestimated the temporal autocorrelation relative to AMSR-E and in situ measurements. This may be due to the different vertical depth of the two products, to the uncertainty in precipitation forcing in ORCHIDEE, and to the fact that the structure of ORCHIDEE consisting of a single-layer deep soil, does not allow simulation of the proper cascade of time scales that characterize soil drying after each rain event. We conclude that assimilating soil moisture in ORCHIDEE using AMSR-E with the current hydrological model may significantly improve the soil moisture dynamics in ORCHIDEE.
Characterizing temporary hydrological regimes at a European scale
Authors: Kirkby M. J. , Gallart F. , Kjeldsen T. R. , Irvine B. J. , Froebrich J. , Lo Porto A. ,   the MIRAGE team
Published: April 2011

Abstract. Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios.
Future storm surge impacts on insurable losses for the North Sea region
Authors: Gaslikova L. , Schwerzmann A. , Raible C. C. , Stocker T. F.
Published: April 2011

Abstract. The influence of climate change on storm surges including increased mean sea level change and the associated insurable losses are assessed for the North Sea basin. In doing so, the newly developed approach couples a dynamical storm surge model with a loss model. The key element of the approach is the generation of a probabilistic storm surge event set. Together with parametrizations of the inland propagation and the coastal protection failure probability this enables the estimation of annual expected losses. The sensitivity to the parametrizations is rather weak except when the assumption of high level of increased mean sea level change is made. Applying this approach to future scenarios shows a substantial increase of insurable losses with respect to the present day. Superimposing different mean sea level changes shows a nonlinear behavior at the country level, as the future storm surge changes are higher for Germany and Denmark. Thus, the study exhibits the necessity to assess the socio-economic impacts of coastal floods by combining the expected sea level rise with storm surge projections.
Biomaterials that Regulate Growth Factor Activity via Bioinspired Interactions
Authors: Hudalla Gregory A. , Murphy William L.
Published: April 2011

Growth factor activity is localized within the natural extracellular matrix (ECM) by specific noncovalent interactions with core ECM biomolecules, such as proteins and proteoglycans. Recently, these interactions inspired the development of synthetic biomaterials that can noncovalently regulate growth factor activity for tissue‐engineering applications. For example, biomaterials covalently or noncovalently modified with heparin glycosaminoglycans can augment growth factor‐release strategies. In addition, recent studies demonstrate that biomaterials modified with heparin‐binding peptides can sequester cell‐secreted heparin proteoglycans and, in turn, sequester growth factors and regulate stem cell behavior. Another set of studies shows that modular versions of growth factor molecules can be designed to interact with specific components of natural and synthetic ECMs, including collagen and hydroxyapatite. In addition, layer‐by‐layer assemblies of GAGs and other natural polyelectrolytes retain growth factors at a cell/material interface via specific noncovalent interactions. This Feature Article provides a detailed overview of the various bioinspired strategies that are used to noncovalently localize growth factor activity within biomaterials, and will highlight in vivo examples of the efficacy of these materials to promote tissue regeneration.
Circadian activity rhythms and risk of incident dementia and mild cognitive impairment in older women
Authors: Tranah Gregory J. , Blackwell Terri , Stone Katie L. , Ancoli‐Israel Sonia , Paudel Misti L. , Ensrud Kristine E. , Cauley Jane A. , Redline Susan , Hillier Teresa A. , Cummings Steven R. , Yaffe Kristine ,   for the SOF Research Group
Published: April 2011

Objective:

Previous cross‐sectional studies have observed alterations in activity rhythms in dementia patients but the direction of causation is unclear. We determined whether circadian activity rhythms measured in community‐dwelling older women are prospectively associated with incident dementia or mild cognitive impairment (MCI).

Methods:

Activity rhythm data were collected from 1,282 healthy community‐dwelling women from the Study of Osteoporotic Fractures (SOF) cohort (mean age 83 years) with wrist actigraphy for a minimum of three 24‐hour periods. Each participant completed a neuropsychological test battery and had clinical cognitive status (dementia, MCI, normal) adjudicated by an expert panel approximately 5 years later. All analyses were adjusted for demographics, body mass index (BMI), functional status, depression, medications, alcohol, caffeine, smoking, health status, and comorbidities.

Results:

After 4.9 years of follow‐up, 195 (15%) women had developed dementia and 302 (24%) had developed MCI. Older women with decreased activity rhythms had a higher likelihood of developing dementia or MCI when comparing those in the lowest quartiles of amplitude (odds ratio [OR] = 1.57; 95% CI, 1.09–2.25) or rhythm robustness (OR = 1.57; 95% CI, 1.10–2.26) to women in the highest quartiles. An increased risk of dementia or MCI (OR = 1.83; 95% CI, 1.29–2.61) was found for women whose timing of peak activity occurred later in the day (after 3:51 PM) when compared to those with average timing (1:34 PM–3:51 PM).

Interpretation:

Older, healthy women with decreased circadian activity rhythm amplitude and robustness, and delayed rhythms have increased odds of developing dementia and MCI. If confirmed, future studies should examine whether interventions (physical activity, bright light exposure) that influence activity rhythms will reduce the risk of cognitive deterioration in the elderly. ANN NEUROL 2011
Von der Fläche ins Volumen – Materialkonzepte für optisch‐holographische Datenspeicher der Zukunft
Authors: Bruder Friedrich‐Karl , Hagen Rainer , Rölle Thomas , Weiser Marc‐Stephan , Fäcke Thomas
Published: April 2011

Die optische Datenspeicherung hat seit Ihrer Markteinführung 1982 das tägliche Leben geprägt. Compact Disk (CD), Digital Versatile Disk (DVD) und Blu‐ray Disk (BD) sind universelle Datenträgerformate mit den Vorteilen des kontaktfreien und damit abnutzungslosen Lesens und Schreibens der digitalen Daten. Sie ermöglichen einen schnellen Datenzugriff, hohe Transferraten und eine stromfreie Datenspeicherung bei sehr günstigen gesamten Archivierungskosten. Der stete Wunsch nach der Erhöhung der Datenspeicherkapazitäten und ‐transferraten treibt die Entwicklung an. Für optische Datenspeicher ist die Nutzung holographischer Prinzipien ein eleganter Weg, diese Parameter weiter zu erhöhen, da hier im Inneren (also im Volumen) des Speichermaterials Daten abgelegt werden und zudem optisch parallel verarbeitet werden können. Dieser Aufsatz beschreibt die grundlegenden Materialanforderungen für holographische Speicher und vergleicht generelle Materialkonzepte. Ein Überblick über aktuelle Demonstrationen von Lese‐Schreib‐Geräten zeigt auf, wie weit die holographische Datenspeicherung schon entwickelt wurde.
Anatomical Boundary of the Tympanic Membrane Pars Flaccida of the Meriones unguiculatus (Mongolian Gerbil)
Authors: Von Unge Magnus , Buytaert Jan A.N. , Dirckx Joris J.J.
Published: April 2011

The pars flaccida of the Meriones unguiculatus (Mongolian gerbil) was in previous studies shown to bulge almost spherically when pressurized, a behavior suggesting that it is suspended by a fixed circular boundary. The question arises whether this “functional” boundary is based on an underlying circular anatomical boundary, an important issue for modeling the middle‐ear mechanics. In this article, the boundaries of the Mongolian gerbil pars flaccida were visualized in situ with otomicroscopy and in slides with light microscopy and by micro‐CT radiology. For the major part of its circumference, the pars flaccida was found to be suspended by rigid bone, that is, the tympanic legs. The remaining boundary is made up of the terminal portion of the handle of the malleus and the soft tissue of the terminal arches. The attachment to these structures is simple and uncomplicated, and the geometry is regular and symmetric: deviating by only 3.5% from a perfect circular shape. The findings justify the use of a fixed circular boundary as a good approximation for the modeling of pars flaccida deformation in the Mongolian gerbil. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Asset allocation under threshold autoregressive models
Authors: Song Na , Siu Tak Kuen , Ching Wa‐Ki , Tong Howell , Yang Hailiang
Published: April 2011

We discuss the asset allocation problem in the important class of parametric non‐linear time series models called the threshold autoregressive model in (J. Roy. Statist. Soc. Ser. A 1977; 140:34–35; Patten Recognition and Signal Processing. Sijthoff and Noordhoff: Netherlands, 1978; and J. Roy. Statist. Soc. Ser. B 1980; 42:245–292). We consider two specific forms, one self‐exciting (i.e. the SETAR model) and the other smooth (i.e. the STAR) model developed by Chan and Tong (J. Time Ser. Anal. 1986; 7:179–190). The problem of maximizing the expected utility of wealth over a planning horizon is considered using a discrete‐time dynamic programming approach. This optimization approach is flexible enough to deal with the optimal asset allocation problem under a general stochastic dynamical system, which includes the SETAR model and the STAR model as particular cases. Numerical studies are conducted to demonstrate the practical implementation of the proposed model. We also investigate the impacts of non‐linearity in the SETAR and STAR models on the optimal portfolio strategies. Copyright © 2011 John Wiley & Sons, Ltd.
MAOA, DBH, and SLC6A4 variants in CHARGE: a case–control study of autism spectrum disorders
Authors: Tassone Flora , Qi Lihong , Zhang Wenting , Hansen Robin L. , Pessah Isaac N. , Hertz‐Picciotto Irva
Published: April 2011

Genetic factors are established to contribute to the development of autism. We examined three loci, serotonin transporter (SLC6A4), dopamine β‐hydroxylase (DBH), and the variable number of tandem repeat promoter of the monoamine oxidase A (MAOA) for association with autism in participants from the Childhood Autism Risks from Genetics and the Environment (CHARGE ) Study, the first large‐scale population‐based case–control investigation of both environmental and genetic contributions to autism risk. Among male children enrolled in the CHARGE study we tested associations between each of the three polymorphisms and autism (AU) (n = 119), or a combined group of autism and other autism spectrum disorders (AU+ASD, which includes an additional n = 53) as compared with typically developing controls (TD, n = 137). The case–control association analysis showed neither SLC6A4 nor DBH to be statistically significantly associated with AU or ASD. However, the male children carrying 4 tandem repeats in the promoter region of the MAOA gene showed a two‐fold higher risk of AU (or AU+ASD) than those carrying allele 3, adjusted for confounders (OR = 2.02, 95% CI = 1.12, 3.65, P = 0.02 for AU vs. TD, and OR = 2.05, 95% CI = 1.19, 3.53, P = 0.01 for ASD vs. TD). In addition, children of mothers homozygous for the 4 tandem repeat allele showed at least a three‐fold higher risk of AU (or AU+ASD) than those with mothers homozygous for allele 3 (OR = 3.07, 95% CI = 1.19, 7.91, P = 0.02 for AU vs. TD, and OR = 3.26, 95% CI = 1.35, 7.89, P = 0.009 for AU+ASD vs. TD). These results suggest a potential role of the functional MAOA promoter alleles in the male child, the mother, or both in ASD. Autism Res 2011,4:250–261. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Adaptation of the “Dynamic Method” for measuring the specific respiration rate in oxygen transfer systems through diffusion membrane
Authors: Pamboukian Marilena Martins , Pereira Carlos Augusto , Augusto Elisabeth de Fatima Pires , Tonso Aldo
Published: April 2011

Monitoring the specific respiration rate
(QO2) is a valuable tool to evaluate cell growth and
physiology. However, for low QO2 values the accuracy may depend on
the measurement methodology, as it is the case in animal cell culture. The widely used “Dynamic Method” imposes serious difficulties concerning oxygen transfer cancellation, especially through membrane oxygenation. This paper presents an improved procedure to this method, through an automated control of the gas inlet composition that can minimize the residual oxygen transfer driving force during the QO2 measurement phase. The improved technique was applied to animal cell cultivation, particularly three recombinant S2 (Drosophila melanogaster) insect cell lines grown in a membrane aeration bioreactor. The average measurements of the proposed method reached 98% of stationary liquid phase balance method, taken as a reference, compared to 21% when the traditional method was used. Furthermore, this methodology does not require knowledge of the volumetric transfer coefficient kLa, which may vary during growth.
Prediction of the aggregation propensity of proteins from the primary sequence: Aggregation properties of proteomes
Authors: Castillo Virginia , Graña‐Montes Ricardo , Sabate Raimon , Ventura Salvador
Published: April 2011

In the cell, protein folding into stable globular conformations is in competition with aggregation into non‐functional and usually toxic structures, since the biophysical properties that promote folding also tend to favor intermolecular contacts, leading to the formation of β‐sheet‐enriched insoluble assemblies. The formation of protein deposits is linked to at least 20 different human disorders, ranging from dementia to diabetes. Furthermore, protein deposition inside cells represents a major obstacle for the biotechnological production of polypeptides. Importantly, the aggregation behavior of polypeptides appears to be strongly influenced by the intrinsic properties encoded in their sequences and specifically by the presence of selective short regions with high aggregation propensity. This allows computational methods to be used to analyze the aggregation properties of proteins without the previous requirement for structural information. Applications range from the identification of individual amyloidogenic regions in disease‐linked polypeptides to the analysis of the aggregation properties of complete proteomes. Herein, we review these theoretical approaches and illustrate how they have become important and useful tools in understanding the molecular mechanisms underlying protein aggregation.
‘The effect of micronutrients on superoxide dismutase in senescent fibroblasts’
Authors: Al‐Sheikh Yazeed A. , Ghneim Hazem K.
Published: April 2011

The specific activities of zinc/copper (Zn/Cu)‐superoxide dismutase (SOD‐1) and manganese (Mn)‐superoxide dismutase (SOD‐2) were assayed in young passage 5 fibroblasts and in serially subcultured cells that were characterized as senescent at passages 15–35. SOD‐1 and SOD‐2 activities did not significantly change in senescent and young cells cultured in either routine medium [minimum essential medium 1 (MEM1)], or in Zn, Cu and Mn supplemented medium (MEM2) containing normal human plasma levels of the cations. SOD‐1 and SOD‐2 activities, however, underwent parallel progressive significant activity increases in senescent passage 20 and 25 cells, which peaked in value in passage 30 and 35 cells subcultured in supplemented medium (MEM3) containing triple human plasma levels of the cations. Concurrently, superoxide radical generation rates underwent progressive significant increases in senescent passage 15–25 cells, which peaked in value in passage 30 and 35 cells subcultured in MEM1 or MEM2. These rates, however, were significantly lowered in senescent cells subcultured in MEM3. We infer that it was only possible to significantly stimulate SOD‐1 and SOD‐2 activities in senescent MEM3 cultured cells enabling them to combat oxidative stress. Copyright © 2011 John Wiley & Sons, Ltd.
Molecular Structures of THF‐Solvated Alkali‐Metal 2,2,6,6‐Tetramethylpiperidides Finally Revealed: X‐ray Crystallographic, DFT, and NMR (including DOSY) Spectroscopic Studies
Authors: Armstrong David R. , García‐Álvarez Pablo , Kennedy Alan R. , Mulvey Robert E. , Robertson Stuart D.
Published: April 2011

The often studied THF solvates of the utility alkali‐metal amides lithium and sodium 2,2,6,6‐tetramethylpiperidide are shown to exist in the solid state as asymmetric cyclic dimers containing a central M2N2 ring and one molecule of donor per metal to give a distorted trigonal planar metal coordination. DFT studies support these structures and confirm the asymmetry in the ring. In C6D12 solution, the lithium amide displays a concentration‐dependent equilibrium between a solvated and unsolvated species which have been shown by diffusion‐ordered NMR spectroscopy (DOSY) to be a dimer and larger oligomer, respectively. A third species, a solvated monomer, is also present in very low concentration, as proven by spiking the NMR sample with THF. In contrast, the sodium amide displays a far simpler C6D12 solution chemistry, consistent with the solid‐state dimeric arrangement but with labile THF ligands.
Sizing of Safety Valves for Multi‐Purpose Plants according to ISO 4126‐10
Authors: Schmidt Jürgen
Published: April 2011

Mehrzweckanlagen werden oft mit Sicherheitsventilen oder Berstscheiben abgesichert. Bei Produktwechseln muss regelmäßig überprüft werden, ob die Sicherheitseinrichtung für neue Produkte ausreichend groß bemessen ist. Die Auslegung kann jedoch sehr aufwendig sein. Deshalb werden energiespezifische Entlastungsflächen für ca. 60 typische Lösungsmittel bestimmt. Bei der Berechnung mit der HNE‐DS‐Methode, wie in ISO 4126‐10 empfohlen, wurde die Entlastung von Dampf/Flüssigkeits‐Gemischen berücksichtigt. Die Ergebnisse erlauben eine schnelle Bestimmung der erforderlichen Entlastungsfläche, wenn der Energieeintrag in den Reaktor bekannt ist. Es ergeben sich signifikant kleinere Entlastungsflächen als nach dem amerikanischem Regelwerk API 520.
Refractive index dispersion of spinel Zn2TiO4 single crystal
Authors: Li Liang , Fan Ya , Wang Dejun , Feng Guanlin , Xu Dapeng
Published: April 2011

The transmittance and absorption spectra of a high‐quality Zn2TiO4 single crystal have been measured along the a‐axes at room‐temperature in the range of 200‐1000 nm. The wavelength dependent refractive index, extinction coefficient, real and imaginary parts of the complex dielectric constant of the Zn2TiO4 crystal have been derived from the measured T and α spectra. By fitting the refractive index spectrum, the Sellmeier dispersion equation of the Zn2TiO4 crystal has been obtained. The validity of Cauchy‐Sellmeier equation has been evaluated in the energy range of 2.90–3.20 eV representing the Urbach tail. Applying the single‐effective oscillator model, the dispersion energy Ed and the oscillator energy E0 have been determined as 18.76 and 5.05 eV, respectively. The obtained dispersion energy Ed takes on ionic crystal value. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cellometer Vision as an alternative to flow cytometry for cell cycle analysis, mitochondrial potential, and immunophenotyping
Authors: Chan Leo L. , Zhong Xuemei , Qiu Jean , Li Peter Y. , Lin Bo
Published: April 2011

Cell phenotyping and cell cycle analysis are two commonly used assays in both clinical diagnosis and biomedical research. Cell phenotyping by identifying different biomarkers is essential for the diagnosis of hematologic malignancy, sub‐classifying diseases, monitoring response to treatment, predicting prognosis, detecting rare cell populations and residual malignant cells. Cell cycle analysis distinguishes cells in different phases of cell cycle and is often used to determine the cellular response to drugs and biological stimulations. These assays have been traditionally carried out by sensitive fluorescence detection methods such as flow cytometry and laser scanning cytometry for fluorescence‐based cell population analysis. However, these instruments remain relatively expensive, large in size, and require a considerable amount of maintenance, which may not be feasible for smaller research groups that do not have access to these equipments or field clinics that require quick diagnostic results on site. Recently, a small portable imaging cytometry system (Cellometer Vision) has been developed by Nexcelom Bioscience LLC (Lawrence, MA) for automated cell concentration and viability measurement using bright‐field and fluorescent imaging methods. Here we report new applications of the Cellometer imaging cytometry for fluorescence‐based cell population analysis and compared them with conventional flow cytometry. Cell population analysis assays such as immunophenotyping, cell cycle, and mitochondrial membrane potential detection methods have not yet been reported for the Cellometer Vision system. Using this imaging cytometry method for fluorescence‐based assays that are typically done by flow cytometry offers a quick, simple, and inexpensive alternative method for biomedical research, which may be beneficial for smaller research laboratories and clinics. © 2011 International Society for Advancement of Cytometry
Uncoupling of retinoic acid signaling from tailbud development before termination of body axis extension
Authors: Cunningham Thomas J. , Zhao Xianling , Duester Gregg
Published: April 2011

During the early stages of body axis extension, retinoic acid (RA) synthesized in somites by Raldh2 represses caudal fibroblast growth factor (FGF) signaling to limit the tailbud progenitor zone. Excessive RA down‐regulates Fgf8 and triggers premature termination of body axis extension, suggesting that endogenous RA may function in normal termination of body axis extension. Here, we demonstrate that Raldh2−/− mouse embryos undergo normal down‐regulation of tailbud Fgf8 expression and termination of body axis extension in the absence of RA. Interestingly, Raldh2 expression in wild‐type tail somites and tailbud from E10.5 onwards does not result in RA activity monitored by retinoic acid response element (RARE)‐lacZ. Treatment of wild‐type tailbuds with physiological levels of RA or retinaldehyde induces RARE‐lacZ activity, validating the sensitivity of RARE‐lacZ and demonstrating that deficient RA synthesis in wild‐type tail somites and tailbud is due to a lack of retinaldehyde synthesis. These studies demonstrate an early uncoupling of RA signaling from mouse tailbud development and show that termination of body axis extension occurs in the absence of RA signaling. genesis 49:776–783, 2011. © 2011 Wiley‐Liss, Inc.
An inducible transgenic Cre mouse line for the study of hippocampal development and adult neurogenesis
Authors: Li Yiping , Tian Chuanxi , Yang Ying , Yan Yan , Ni Yang , Wei Yiquan , Pleasure Samuel J. , Zhao Chunjie
Published: April 2011

The hippocampus is crucial for higher brain functions, such as learning, memory, and emotion. Many diseases like epilepsy and Down's syndrome are associated with abnormalities in early hippocampal development. In addition, adult dentate neurogenesis is thought to be defective in several classes of psychiatric disorders. However, the mechanisms regulating hippocampal development and adult neurogenesis remain unclear. One of the limitations to studying these processes is the scarcity of available specific mouse tools. Here, we report an inducible transgenic Cre mouse line, Frizzled 9‐CreER™, in which tamoxifen administration induces Cre recombinant. Our data show that Cre is expressed in the developing hippocampal primordium, confined to the granule cell layer at P20 and further limited to the subgranular zone in the adult dentate gyrus. Cre recombinase shows very high activity in all of these regions. Thus, this transgenic line will be a powerful tool in understanding the mechanisms of hippocampal development, adult neurogenesis, and associated diseases. genesis 49:919–926, 2011. © 2011 Wiley Periodicals, Inc.
In Vivo labeling of zebrafish motor neurons using an mnx1 enhancer and Gal4/UAS
Authors: Zelenchuk Taras A. , Brusés Juan L.
Published: April 2011

The zebrafish spinal cord primary motor neurons are commonly used as an experimental model to study the molecular mechanisms that regulate axonal pathfinding and neuromuscular junction formation, and for the modeling of human neurodegenerative disorders. This study characterized a 125‐bp mnx1 enhancer to direct gene expression in spinal cord motor neurons. A promoter containing three copies of the 125‐bp mnx1 enhancer was generated in a Tol2 vector and used to drive enhanced green fluorescent protein (EGFP) expression either directly or in combination with the Gal4/UAS transcriptional activation system. Both methods induced protein expression for up to 5 days after fertilization, allowing the observation of the dendritic tree and axonal arborization of single motor neurons within a somitic segment in fixed and live animals. The use of the 125‐bp mnx1 promoter for transient transgenic expression or for the generation of stable transgenic fish lines will facilitate the study of motor neuron development and neurodegenerative processes. genesis 49:543–554, 2011. © 2011 Wiley‐Liss, Inc.
The adjuvant effect of TLR agonists on CD4+ effector T cells is under the indirect control of regulatory T cells
Authors: Olivier Aurélie , Sainz‐Perez Alexander , Dong Hui , Sparwasser Tim , Majlessi Laleh , Leclerc Claude
Published: April 2011

TLR agonists have been suggested to directly impact Tregs, thereby enhancing or reversing their suppressive function. Here, in order to select TLR agonists leading to potent effector T‐cell responses, while minimizing Treg inhibitory function, we used a model antigen, covalently linked to an inert delivery system, combined with a large panel of TLR agonists, for the immunization of mice with an attenuated/depleted or intact Treg subset. We observed that the negative modulation of effector CD4+ T cells exerted by Tregs cannot be circumvented, whatever the TLR agonist used as adjuvant. To better understand the impact of TLR agonists on Tregs, we investigated (i) the TLR expression profile of highly purified CD4+ Foxp3+ Tregs, at steady state or subsequent to in vivo activation by TLR agonists and (ii) the Treg phenotype after in vivo and in vitro activation by TLR agonists. Our results demonstrate that TLR agonists, as single signal inducers, are not able to directly activate Tregs. The phenotypic Treg activation observed in vivo, following TLR administration, does not result from cross‐talk with conventional T cells but is rather a consequence of the interaction with other immune cell type(s).
A Solid‐State Electrochemiluminescence Immunosensor Based on MWCNTs‐Nafion and Ru(bpy)32+/Nano‐Pt Nanocomposites for Detection of α‐Fetoprotein
Authors: Cao Yaling , Yuan Ruo , Chai Yaqin , Mao Li , Yang Xia , Yuan Shirong , Yuan Yali , Liao Yuhong
Published: April 2011

A approach was successfully employed for constructing a solid‐state electrochemiluminescence (ECL) immunosensor by layer‐by‐layer self‐assembly of multiwall carbon nanotubes (MWCNTs)‐Nafion composite film, Ru(bpy)32+/nano‐Pt aggregates (Ru‐PtNPs) and Pt nanoparticles (PtNPs). The influence of Pt nanoparticles on the ECL intensity was quantitatively evaluated by calculating the electroactive surface area of different electrodes with or without PtNPs to immobilize Ru(bpy)32+. The principle of ECL detection for target α‐fetoprotein antigen (AFP) was based on the increment of resistance after immunoreaction, which led to a decrease in ECL intensity. The linear response range was 0.01–10 ng mL−1 with the detection limit of 3.3 pg mL−1. The immunosensor exhibited advantages of simple preparation and operation, high sensitivity and good selectivity.
Modeling of RC columns strengthened with RC jackets
Authors: Lampropoulos A. P. , Dritsos S. E.
Published: April 2011

Constructing concrete jackets is a common technique when strengthening reinforced concrete (RC) columns, particularly in seismic regions. However, there are many uncertainties concerning the behavior of the composite specimen, particularly at the interface between the old and new concrete. In this paper, monotonic finite element (FE) analyses are performed to examine the behavior of strengthened columns under monotonic and cyclic loading. Through investigating two independent series of experimental results, it is demonstrated that monotonic FE analysis with appropriate assumptions can simulate both monotonic and cyclic loading conditions to a reasonable degree of accuracy. According to the results of this study, it is found that a simulation of the interface between the old and the new concrete is vital and cannot be ignored by simply considering a perfect bond at the interface. In the case of strengthened RC columns subjected to cyclic loading, strength degradation at the interface has to be included and can be effectively modeled by reducing the coefficients of friction and adhesion by using a proposed formula. Finally, the effect of jacket concrete shrinkage is simulated that leads to a reduced maximum load and stiffness of strengthened columns. Copyright © 2011 John Wiley & Sons, Ltd.
Assessment of indirect pesticide effects on worm-eating warbler populations in a managed forest ecosystem
Authors: Awkerman Jill A , Marshall Matthew R , Williams Alan B , Gale George A , Cooper Robert J , Raimondo Sandy
Published: April 2011

Ecological risk assessments rarely evaluate indirect pesticide effects. Pesticides causing no direct mortality in wildlife can still reduce prey availability, resulting in a lower reproductive rate or poor juvenile condition. Few studies have examined these consequences at the population level. We use a four-year data set from a forest ecosystem in which Bacillus thuringiensis kurstaki (Btk) was applied to control gypsy moths (Lymantria dispar L.). Lower worm-eating warbler (Helmitheros vermivorus) productivity on Btk plots contributed to an intrinsic growth rate <1. Altered provisioning behavior by adults led to lower nestling mass in Btk-treated plots, and simulations of reduced juvenile survival expected as a result further reduced population growth rate. The present study explored different spatial representations of treated areas, using a two-patch matrix model incorporating dispersal. Minimal migration from areas with increasing subpopulations could compensate for detrimental reductions in reproductive success and juvenile survival within treated subpopulations. We also simulated population dynamics with different proportions of treated areas to inform management strategies in similar systems. Nontoxic insecticides are capable of impacting nontarget populations with consistent, long-term use and should be evaluated based on the spatial connectivity representative of habitat availability and the time period appropriate for risk assessment of pesticide effects in wildlife populations. Environ. Toxicol. Chem. © 2011 SETAC