bluuebunny/crossref_metadata_2025 huggingface dataset:
Global Distribution of Cloud Top Height as Retrieved from SCIAMACHY Onboard ENVISAT Spaceborne Observations
Authors: Kokhanovsky Alexander , Vountas Marco , Burrows John P.
Published: April 2011

The spatial and temporal analysis of the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) onboard ENVISAT global cloud top height data for 2003–2006 is presented. The cloud top height is derived using a semi-analytical cloud top height retrieval algorithm based on an asymptotic solution of the radiative transfer equation in the oxygen A-band. The analysis is valid for thick clouds only. As expected, clouds are higher in the equatorial region. The cloud altitudes decrease towards the Poles due to the general decrease of the troposphere height. The global average cloud top height as derived from SCIAMACHY measurements is 7.3 km. We also studied the planetary reflectivity R at 443 nm and found that the annual average is R = 0.49 ± 0.08 for the years analyzed.
The Evolution of Technology Innovation at Dakin Farms
Authors: Ratnasingam Pauline
Published: April 2011

The evolution of technology innovation by businesses using the Internet is transforming and reshaping the nature of inter-organizational commerce and relationships. This case proposes the evolution of technology innovation by a popular family-owned business situated in Vermont. It investigates the technology innovation at Dakin Farms applying the systems development life cycle methodology. The case analyzes phases of IT implementation and its influence on inter-organizational systems and relationships that in turn affects employees’ morale and culture. The case contributes to research, practice, and education.
E-Commerce and SMEs
Authors: Poon Simpson , Huang Xueli (Charlie)
Published: April 2011

Since the middle of the 1990s when e-commerce1 promised to transform the way business is done, curiosity about what impact it has on small to medium-sized enterprises (SMEs) was raised. Throughout the 1990s till this chapter was written, academia, industry, and governments around the world have carried out much research in this area. The efforts range from studying adoption of e-commerce to understanding what contributed to the success of e-commerce. Some focused on the technical issues while other looked at organizational and management concerns. Despite this wealth of added knowledge, there is only a fragmented understanding of how SMEs have benefited from e-commerce. In this chapter, we attempt to provide a reflection, based on the research published, on how SMEs have fared in the era of e-commerce. We conclude that further consolidation of the understanding will be developed by systematically refining research so far carried out.
Multiple, correlated covariates associated with differential item functioning (DIF): Accounting for language DIF when education levels differ across languages
Authors: Gibbons Laura , Crane Paul K. , Mehta Kala M. , Pedraza Otto , Tang Yuxiao , Manly Jennifer J. , Narasimhalu Kaavya , Teresi Jeanne , Jones Richard N. , Mungas Dan
Published: April 2011

Differential item functioning (DIF) occurs when a test item has different statistical properties in subgroups, controlling for the underlying ability measured by the test. DIF assessment is necessary when evaluating measurement bias in tests used across different language groups. However, other factors such as educational attainment can differ across language groups, and DIF due to these other factors may also exist. How to conduct DIF analyses in the presence of multiple, correlated factors remains largely unexplored. This study assessed DIF related to Spanish versus English language in a 44-item object naming test. Data come from a community-based sample of 1,755 Spanish- and English-speaking older adults. We compared simultaneous accounting, a new strategy for handling differences in educational attainment across language groups, with existing methods. Compared to other methods, simultaneously accounting for language- and education-related DIF yielded salient differences in some object naming scores, particularly for Spanish speakers with at least 9 years of education. Accounting for factors that vary across language groups can be important when assessing language DIF. The use of simultaneous accounting will be relevant to other cross-cultural studies in cognition and in other fields, including health-related quality of life.
The impact of temperature changes on summer time ozone and its precursors in the Eastern Mediterranean
Authors: Im U. , Markakis K. , Poupkou A. , Melas D. , Unal A. , Gerasopoulos E. , Daskalakis N. , Kindap T. , Kanakidou M.
Published: April 2011

Abstract. Changes in temperature due to variability in meteorology and climate change are expected to significantly impact atmospheric composition. The Mediterranean is a climate sensitive region and includes megacities like Istanbul and large urban agglomerations such as Athens. The effect of temperature changes on gaseous air pollutant levels and the atmospheric processes that are controlling them in the Eastern Mediterranean are here investigated. The WRF/CMAQ mesoscale modeling system is used, coupled with the MEGAN model for the processing of biogenic volatile organic compound emissions. A set of temperature perturbations (spanning from 1 to 5 K) is applied on a base case simulation corresponding to July 2004. The results indicate that the Eastern Mediterranean basin acts as a reservoir of pollutants and their precursor emissions from large urban agglomerations. During summer, chemistry is a major sink at these urban areas near the surface, and a minor contributor at downwind areas. On average, the atmospheric processes are more effective within the first 1000 m above ground. Temperature increases lead to increases in biogenic emissions by 9±3% K−1. Ozone mixing ratios increase almost linearly with the increases in ambient temperatures by 1±0.1 ppb O3 K−1 for all studied urban and receptor stations except for Istanbul, where a 0.4±0.1 ppb O3 K−1 increase is calculated, which is about half of the domain-averaged increase of 0.9±0.1 ppb O3 K−1. The computed changes in atmospheric processes are also linearly related with temperature changes.
Impact of a large wildfire on water-soluble organic aerosol in a major urban area: the 2009 Station Fire in Los Angeles County
Authors: Wonaschütz A. , Hersey S. P. , Sorooshian A. , Craven J. S. , Metcalf A. R. , Flagan R. C. , Seinfeld J. H.
Published: April 2011

Abstract. Water-soluble organic carbon is a major component of aerosol particles globally. This study examines a field dataset of water-soluble organic aerosol in the Los Angeles Basin, a classic urban setting, under typical conditions and under the influence of a large wildfire (the 2009 Station Fire). The measurements took place between July and September in Pasadena as part of the 2009 Pasadena Aerosol Characterization Observatory (PACO) field campaign. Large differences in the nature of water-soluble organic carbon (WSOC) were observed between periods with and without the influence of the fire. During non-fire periods, WSOC variability was driven most likely by a combination of photochemical production processes and subsequent sea breeze transport, resulting in an average diurnal cycle with a maximum at 15:00 LT (up to 4.9 μg C m−3). During the Station Fire, smoke plumes advected to the site in the morning hours were characterized by high concentrations of WSOC (up to 41 μg C m−3) in tight correlation with nitrate and chloride, and with Aerodyne Aerosol Mass Spectrometer (AMS) organic metrics such as the biomass burning tracer m/z 60, and total non-refractory organic mass. These concentrations and correlations and the proximity of the measurement site to the fire suggest that primary production was a key formation mechanism for WSOC. During the afternoons, the sea breeze transported urban pollution and processed residual smoke back to the measurement site, leading to higher afternoon WSOC levels than on non-fire days. Parameters representing higher degrees of oxidation of organics, including the ratios m/z 44 : m/z 57 and m/z 44 : m/z 43, were increased in those air masses. Intercomparisons of relative amounts of WSOC, AMS organic, m/z 44, and m/z 43 are used to examine how the relative abundance of different classes of WSOC species changed as a result of photochemical aging. The fraction of WSOC comprised of acid-oxygenates increased as a of photochemical aging owing to the conversion of aliphatic and non-acid oxygenated organics to more acid-like organics. Assuming a factor of 1.8 to convert WSOC concentrations to organic mass-equivalent concentrations, the contribution of water-soluble organic species to the organic mass budget (10th–90th percentile values) ranged between 27–72% and 27–68% during fire and non-fire periods, respectively. Therefore, WSOC is a significant contributor to the organic aerosol budget in this urban area. The influence of fires in this basin greatly enhances the importance of this class of organics, which has implications for the radiative and hygroscopic properties of the regional aerosol.
New particle formation infrequently observed in Himalayan foothills – why?
Authors: Neitola K. , Asmi E. , Komppula M. , Hyvärinen A.-P. , Raatikainen T. , Panwar T. S. , Sharma V. P. , Lihavainen H.
Published: April 2011

Abstract. A fraction of the Himalayan aerosols originate from secondary sources, which are currently poorly quantified. To clarify the climatic importance of regional secondary particle formation at Himalayas, data from 2005 to 2010 of continuous aerosol measurements at a high-altitude (2180 m) Indian Himalayan site, Mukteshwar, were analyzed. For this period, the days were classified, and the particle formation and growth rates were calculated for clear new particle formation (NPF) event days. The NPF events showed a pronounced seasonal cycle. The frequency of the events peaked in spring, when the ratio between event and non-event days was 53 %, whereas the events were truly sporadic on any other seasons. The annual mean particle formation and growth rates were 0.40 cm−3 s−1 and 2.43 nm h−1, respectively. The clear annual cycle was found to be mainly controlled by the seasonal evolution of the Planetary Boundary Layer (PBL) height together with local meteorological conditions. Spring NPF events were connected with increased PBL height, and therefore characterised as boundary layer events, while the rare events in other seasons represented lower free tropospheric particle formation.
Short term changes in methanol emission and pectin methylesterase activity are not directly affected by light in Lycopersicon esculentum
Authors: Oikawa P. Y. , Li L. , Timko M. P. , Mak J. E. , Lerdau M. T.
Published: April 2011

Abstract. Plants are an important source of atmospheric methanol (MeOH), the second most abundant organic gas after methane. Factors regulating phytogenic MeOH production are not well constrained in current MeOH emission models. Previous studies have indicated that light may have a direct influence on MeOH production. As light is known to regulate cell wall expansion, it was predicted that light would stimulate MeOH production through the pectin methylesterase (PME) pathway. MeOH emissions normalized for stomatal conductance (gs) did not, however, increase with light over short time scales (20–30 min). After experimentally controlling for gs and temperature, no light activation of PME activity or MeOH emission was observed. The results clearly demonstrate that light does not directly influence short-term changes in MeOH production and emission. Our data suggest that substrate limitation may be important in regulating MeOH production over short time scales. Future investigation of the long-term impacts of light on MeOH production may increase understanding of MeOH emission dynamics at the seasonal time scale.
Labile Fe(II) concentrations in the Atlantic sector of the Southern Ocean along a transect from the subtropical domain to the Weddell Sea Gyre
Authors: Sarthou G. , Bucciarelli E. , Chever F. , Hansard S. P. , Gonzalez-Davila M. , Santana-Casiano J. M. , Planchon F. , Speich S.
Published: April 2011

Abstract. Labile Fe(II) distributions were investigated in the Sub-Tropical South Atlantic and the Southern Ocean during the BONUS-GoodHope cruise from 34 to 57° S (February–March 2008). Concentrations ranged from below the detection limit (0.009 nM) to values as high as 0.125 nM. In the surface mixed layer, labile Fe(II) concentrations were always higher than the detection limit, with values higher than 0.060 nM south of 47° S, representing between 39% and 63% of dissolved Fe (DFe). Biological production was evidenced. At intermediate depth, local maxima were observed, with the highest values in the Sub-Tropical domain at around 200 m, and represented more than 70% of DFe. Remineralization processes were likely responsible for those sub-surface maxima. Below 1500 m, concentrations were close to or below the detection limit, except at two stations (at the vicinity of the Agulhas ridge and in the north of the Weddell Sea Gyre) where values remained as high as ~0.030–0.050 nM. Hydrothermal or sediment inputs may provide Fe(II) to these deep waters. Fe(II) half life times (t1/2) at 4 °C were measured in the upper and deep waters and ranged from 2.9 to 11.3 min, and from 10.0 to 72.3 min, respectively. Measured values compared quite well in the upper waters with theoretical values from two published models, but not in the deep waters. This may be due to the lack of knowledge for some parameters in the models and/or to organic complexation of Fe(II) that impact its oxidation rates. This study helped to considerably increase the Fe(II) data set in the Ocean and to better understand the Fe redox cycle.
Multi-objective automatic calibration of hydrodynamic models utilizing inundation maps and gauge data
Authors: Dung N. V. , Merz B. , Bárdossy A. , Thang T. D. , Apel H.
Published: April 2011

Abstract. Automatic and multi-objective calibration of hydrodynamic models is – compared to other disciplines like e.g. hydrology – still underdeveloped. This has mainly two reasons: the lack of appropriate data and the large computational demand in terms of CPU-time. Both aspects are aggravated in large-scale applications. However, there are recent developments that improve the situation on both the data and computing side. Remote sensing, especially radar-based techniques proved to provide highly valuable information on flood extents, and in case high precision DEMs are present, also on spatially distributed inundation depths. On the computing side the use of parallelization techniques brought significant performance gains. In the presented study we build on these developments by calibrating a large-scale 1-dimensional hydrodynamic model of the whole Mekong Delta downstream of Kratie in Cambodia: we combined in-situ data from a network of river gauging stations, i.e. data with high temporal but low spatial resolution, with a series of inundation maps derived from ENVISAT Advanced Synthetic Aperture Radar (ASAR) satellite images, i.e. data with low temporal but high spatial resolution, in an multi-objective automatic calibration process. It is shown that an automatic, multi-objective calibration of hydrodynamic models, even of such complexity and on a large scale and complex as a model for the Mekong Delta, is possible. Furthermore, the calibration process revealed model deficiencies in the model structure, i.e. the representation of the dike system in Vietnam, which would have been difficult to detect by a standard manual calibration procedure.
Tailoring seasonal climate forecasts for hydropower operations
Authors: Block P.
Published: April 2011

Abstract. Integration of seasonal precipitation forecasts into water resources operations and planning is practically nonexistent, even in regions of scarcity. This is often attributable to water manager's tendency to act in a risk averse manner, preferring to avoid consequences of poor forecasts, at the expense of unrealized benefits. Convincing demonstrations of forecast value are therefore desirable to support assimilation into practice. A dynamically linked system, including forecast, rainfall-runoff, and hydropower models, is applied to the upper Blue Nile basin in Ethiopia to compare benefits and reliability generated by actual forecasts against a climatology-based approach, commonly practiced in most water resources systems. Processing one hundred decadal sequences demonstrates superior forecast-based benefits in 68 cases, a respectable advancement, however benefits in a few forecast-based sequences are noticeably low, likely to dissuade manager's adoption. A hydropower sensitivity test reveals a propensity toward poor-decision making when forecasts over-predict wet conditions. Tailoring the precipitation forecast to highlight critical dry forecasts minimizes this inclination, resulting in 97% of the sequences favoring the forecast-based approach. Considering managerial risk preferences for the system, even risk-averse actions, if coupled with forecasts, exhibit superior benefits and reliability compared with risk-taking tendencies conditioned on climatology.
Subsurface lateral flow from hillslope and its contribution to nitrate loading in the streams during typical storm events in an agricultural catchment
Authors: Tang J. , Zhang B. , Gao C. , Zepp H.
Published: April 2011

Abstract. Compared with overland flow from agricultural hillslopes, subsurface lateral flow is often overlooked partly due to monitoring difficulties and the lack of quantitative identification its role in nutrient delivery to surface water. The objectives of this study were to examine how subsurface lateral flow generates from hillslopes to streams and to quantify its contribution to nutrient loading in streams. Hillslope hydrology and stream hydrology were simultaneously monitored during two typical storms and subsurface flow was separated by chemical mixing model. Positive soil water potential at the soil depths from 0.60 to 1.50 m was observed at the middle course of the storm events, suggesting soil water was saturated following the storms and the drained after the end of the storms. The hydro-chemographs in the stream in a trench below a hillslope showed that suspended sediment, particulate N and P were dominant in the stream during the storms, while after the end of the rainstorms the nitrate concentration and electricity conductivity (EC) in the stream increased with time on the recession limbs of the hydrographs. Meanwhile, a rebound or delayed curve appeared on the recession limbs for several hours immediately after the end of rainstorms. All the synchronous data confirmed nitrate was delivered from the hillslope through subsurface lateral flow to the streams even after the end of rainstorms. A chemical mixing model based on EC and pH showed that the subsurface lateral flow during the rainstorm events accounted for 29% to 45% of the stream flow and about 86% of total NO3−-N loss (or 26% of total N loss) from the peanut hillslope and for 5.7% to 7.3% of the stream flow about 69% of total NO3−-N loss (or 28% of total N loss) from the catchment outlet. The results suggest that subsurface lateral flow generated within a shallow soil profile have to be paid more attention for controlling non-point source surface water pollution from intensive agricultural catchment.
“Il Corpo Ritrovato”: Dermocosmetological Skin Care Project for the Oncologic Patient
Authors: Fabbrocini G. , Romano M. C. , Cameli N. , Mariano M. , Pastore F. , Annunziata M. C. , Mazzella C. , De Vita Valerio , Mauriello Maria Chiara , Monfrecola G.
Published: April 2011

Neoplastic disease and its therapeutic options have a huge impact on the patient's quality of life from both the emotional and the working point of view. The project “Il Corpo Ritrovato” aims at creating an interdisciplinary network of physicians to improve the quality of life of the oncologic patient, focusing on such important aspects as dermocosmetological skin care but also on the evaluation of new therapeutic and diagnostic algorithms in order to make further progress in the field of prevention.
Improved Pulmonary Inflammation and Fibrosis Progression after Influenza A (H1N1) Infection by Chinese Herbal Medicine: A Case Report
Authors: Huang Yao-Zhang , Hsieh Mao-Wei , Hung Chien-Hui , Hsu Chung-Hua
Published: April 2011

Influenza A (H1N1) virus was the most common cause of human influenza (flu) in 2009. We report a patient infected with influenza A virus who showed improvement in his pulmonary inflammation and fibrosis progression after switching to Chinese herbal medicine (CHM) therapy. Although antiviral drug and corticosteroids were administered, some disturbing respiratory illness and immune imbalance attributed to corticosteroids taken prompted him to seek for CHM therapy. After CHM treatment for three months, significant recovery in chest radiograph was noted, and the result of subsequent pulmonary function test showed improvement.
Computational Study of Coordinated Ni(II) Complex with High Nitrogen Content Ligands
Authors: Tang Bo , Ye Jia-Hai , Ju Xue-Hai
Published: April 2011

Density functional computations were performed on two tetracoordinated Ni(II) complexes as high nitrogen content energetic materials (1: dinickel bishydrazine ter[(1H-Tetrazol-3-yl)methan-3yl]-1H-tetrazole and 2: dinickel tetraazide ter[(1H-Tetrazol-3-yl)methan-3yl]-1H-tetrazolate). The geometrical structures, relative stabilities and sensitivities, and thermodynamic properties of the complexes were investigated. The energy gaps of frontier molecular orbital (HOMO and LUMO) and vibrational spectroscopies were also examined. There are minor Jahn-Teller distortions in both complexes 1 and 2, with two long Ni–N bond lengths and two short ones. The enthalpies of combustion for both complexes are over 3600 kJ/mol. The N–N bond lengths in the moieties of hydrazine and azide ligands increase in the coordination process compared to those of the isolated molecules.
Carbon Fiber–Bismaleimide Composites Filled with Nickel‐Coated Single‐Walled Carbon Nanotubes for Lightning‐Strike Protection
Authors: Chakravarthi Divya K. , Khabashesku Valery N. , Vaidyanathan Ranji , Blaine Jeanette , Yarlagadda Shridhar , Roseman David , Zeng Qiang , Barrera Enrique V.
Published: April 2011

Multifunctional carbon fiber composites are imperative for next‐generation lightweight aircraft structures. However, lightning‐strike protection is a feature that is lacking in many modern carbon fiber high‐temperature polymer systems, due to their high electrical resistivity. This work presents a study on processing, materials optimization, and property development of high‐temperature bismaleimide (BMI)–carbon fiber composites filled with nickel‐coated single‐walled carbon nanotubes (Ni‐SWNTs) based on three key factors: i) dispersion of Ni‐SWNTs, ii) their surface coverage on the carbon plies and, iii) the composite surface resistivity. Atomic force microscopy analysis revealed that coating purified SWNTs with nickel enabled improved dispersion which resulted in uniform surface coverage on the carbon plies. The electrical resistivity of the baseline composite system was reduced by ten orders of magnitude by the addition of 4 wt% Ni‐SWNTs (calculated with respect to the weight of a single carbon ply). Ni‐SWNT–filled composites showed a reduced amount of damage to simulated lightning strike compared to their unfilled counterparts, as indicated by the minimal carbon fiber pull‐out.
Complete remission in nonsyndromic childhood‐onset epilepsy
Authors: Berg Anne T. , Testa Francine M. , Levy Susan R.
Published: April 2011

Objective:

Determine the probability of attaining complete remission in children with nonsyndromic epilepsy (NSE) over the course of ≥10 years from initial diagnosis; identify early predictors of complete remission; and assess the risk of relapse after achieving complete remission.

Methods:

In a prospective community‐based cohort, complete remission was defined as 5 years seizure‐free and medication‐free. Any subsequent seizure for any reason was a relapse. Univariate and bivariate analyses were conducted with standard methods including the Kaplan‐Meier approach. Proportional hazards modeling was used for multivariable analysis.

Results:

Of 613 cohort members, 347 had NSEs, of whom 294 (85%) were followed ≥10 years (maximum = 17.9). A total of 170 in 294 (58%) achieved complete remission, 10 of whom (6%) relapsed. Seizure outcome at 2 years (remission, pharmacoresistant, unclear) (p < 0.0001) and underlying cause (p < 0.0001) distinguished groups with complete remission ranging from ∼20% to ∼75%. Older age at onset was independently associated with a poorer chance of complete remission. Relapses occurred up to 7.5 years after attaining complete remission and were marginally associated with underlying cause (p = 0.06).

Interpretation:

Complete remission occurs in over one‐half of young people with NSE and generally persists. Meaningful but imperfect predication is possible based on underlying cause and early seizure control. The finding of age effects may play a role in meaningful identification of phenotypes, which could become fruitful targets for genetic and imaging investigations in these otherwise poorly differentiated epilepsies. ANN NEUROL 2011;
Contrast gain control abnormalities in idiopathic generalized epilepsy
Authors: Tsai Jeffrey J. , Norcia Anthony M. , Ales Justin M. , Wade Alex R.
Published: April 2011

Objective:

The origin of neural hyperexcitability underlying idiopathic generalized epilepsy (IGE) is not known. The objective of this study is to identify evidence of hyperexcitability in precisely measured visual evoked responses and to understand the nature of changes in excitation and inhibition that lead to altered responses in human patients with IGE.

Methods:

Steady‐state visual‐evoked potentials (VEPs) to contrast reversing gratings were recorded over a wide range of stimulus contrast. VEPs were analyzed at the pattern reversal rate using spectral analysis. Ten patients with IGE and 13 healthy subjects participated. All subjects had normal visual acuity and had no history of photic‐induced seizures or photoparoxysmal electroencephalograph (EEG) activity.

Results:

At a group level, the amplitude of visual responses did not saturate at high stimulus contrast in patients, as it did in the control subjects. This reflects an abnormality in neuronal gain control. The VEPs did not have sufficient power to reliably distinguish patients from controls at an individual level. Parametric modeling using a standard gain control framework showed that the abnormality lay in reduced inhibition from neighboring neurons rather than increased excitatory response to the stimulus.

Interpretation:

Visual evoked responses reveal changes in a fundamental mechanism regulating neuronal sensitivity. These changes may give rise to hyperexcitability underlying generalized epilepsy. ANN NEUROL 2011;
From the Surface to Volume: Concepts for the Next Generation of Optical–Holographic Data‐Storage Materials
Authors: Bruder Friedrich‐Karl , Hagen Rainer , Rölle Thomas , Weiser Marc‐Stephan , Fäcke Thomas
Published: April 2011

Optical data storage has had a major impact on daily life since its introduction to the market in 1982. Compact discs (CDs), digital versatile discs (DVDs), and Blu‐ray discs (BDs) are universal data‐storage formats with the advantage that the reading and writing of the digital data does not require contact and is therefore wear‐free. These formats allow convenient and fast data access, high transfer rates, and electricity‐free data storage with low overall archiving costs. The driving force for development in this area is the constant need for increased data‐storage capacity and transfer rate. The use of holographic principles for optical data storage is an elegant way to increase the storage capacity and the transfer rate, because by this technique the data can be stored in the volume of the storage material and, moreover, it can be optically processed in parallel. This Review describes the fundamental requirements for holographic data‐storage materials and compares the general concepts for the materials used. An overview of the performance of current read–write devices shows how far holographic data storage has already been developed.
Epithelial Membrane Protein 1 Inhibits Human Spinal Chondrocyte Differentiation
Authors: Li Zhi‐Yong , Xiong Shao‐Hu , Hu Ming , Zhang Chuan‐Sen
Published: April 2011

The molecular mechanisms underlying human spinal chondrocyte differentiation remain unclear. We recently demonstrated that epithelial membrane protein 1 (EMP1) is highly expressed in degenerative intervertebral discs. EMP1 is involved in the differentiation of multiple cell types, including progenitor/pre‐B cells, neurons, and podocytes. Therefore, we hypothesize that EMP1 may participate in the differentiation of spinal chondrocytes. We cultured chondrocytes from human nucleus pulposus. Through lentivirus‐mediated knockdown and overexpression of EMP1, we find that EMP1 promotes cell proliferation and survival, alters cell morphology and cell cycle, reduces cell condensation, and inhibits cell hypertrophy and the expression of chondrocyte maturation markers such as collagen X, aggrecan, sex‐determining region Y (SRY)‐box 9, and runt‐related transcription factor 2. We also show that EMP1 is not expressed in the ossification center of vertebrae but is highly expressed in the nucleus pulposus and growth plate, where chondrocytes are immature and endochondral ossification has not occurred. These results suggest that EMP1 inhibits human spinal chondrocyte differentiation. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Mutation probability of cytochrome P450 based on a genetic algorithm and support vector machine
Authors: Yao Yu , Zhang Tao , Xiong Yi , Li Li , Huo Juan , Wei Dong‐Qing
Published: April 2011

The support vector machine (SVM), an effective statistical learning method, has been widely used in mutation prediction. Two factors, i.e., feature selection and parameter setting, have shown great influence on the efficiency and accuracy of SVM classification. In this study, according to the principles of a genetic algorithm (GA) and SVM, we developed a GA‐SVM program and applied it to human cytochrome P450s (CYP450s), which are important monooxygenases in phase I drug metabolism. The program optimizes features and parameters simultaneously, and hence fewer features are used and the overall prediction accuracy is improved. We focus on the mutation of non‐synonymous single nucleotide polymorphisms (nsSNPs) in protein sequences that appear to exhibit significant influences on drug metabolism. The final predictive model has a quite satisfactory performance, with the prediction accuracy of 61% and cross‐validation accuracy of 73%. The results indicate that the GA‐SVM program is a powerful tool in optimizing mutation predictive models of nsSNPs of human CYP450s.
The aggregation properties of Escherichia coli proteins associated with their cellular abundance
Authors: Castillo Virginia , Graña‐Montes Ricardo , Ventura Salvador
Published: April 2011

Proteins are key players in most cellular processes. Therefore, their abundances are thought to be tightly regulated at the gene‐expression level. Recent studies indicate, however, that steady‐state cellular‐protein concentrations correlate better across species than the levels of the corresponding mRNAs; this supports the existence of selective forces to maintain precise cellular‐protein concentrations and homeostasis, even if gene‐expression levels diverge. One of these forces might be the avoidance of protein aggregation because, in the cell, the folding of proteins into functional conformations might be in competition with anomalous aggregation into non‐functional and usually toxic structures in a concentration‐dependent manner. The data in the present work provide support for this hypothesis because, in E. coli, the experimental solubility of proteins correlates better with the cellular abundance than with the gene‐expression levels. We found that the divergence between protein and mRNAs levels is low for high‐abundance proteins. This suggests that because abundant proteins are at higher risk of aggregation, cellular concentrations need to be stringently regulated by gene expression.
Evaluation of polysaccharide‐based chiral stationary phases in quality control of (S)‐mirtazapine
Authors: Rao R. Nageswara , Maurya Pawan K. , Guruprasad K.
Published: April 2011

High‐performance liquid chromatographic methods were developed for separation of the enantiomers of mirtazapine and its four process‐related substances. The direct separations were achieved on chiral stationary phases containing amylose tris(3,5‐dimethylphenylcarbamate) (Chiralpak® AD‐H), cellulose tris(3,5‐dimethylphenylcarbamate) (Chiralcel® OD‐H) and cellulose tris(4‐methylbenzoate) (Chiralcel® OJ‐H ). The experimental data were utilized to discuss the effects of the mobile phase composition, the nature of the alcoholic modifier and the specific structural features of the analytes on retention and separation. The elution sequence was determined under the optimized separation conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Multiblock redundancy analysis: interpretation tools and application in epidemiology
Authors: Bougeard Stéphanie , Qannari El Mostafa , Rose Nicolas
Published: April 2011

For the purpose of exploring and modeling the relationships between a dataset Y and several datasets () measured on the same individuals, multiblock Partial Least Squares is a regression technique which is widely used, particularly in process monitoring, chemometrics and sensometrics. In the same vein, a new multiblock method, called multiblock Redundancy Analysis, is proposed. It is introduced by maximizing a criterion that reflects the objectives to be addressed. The solution of this maximization problem is directly derived from the eigenanalysis of a matrix. In addition, this method is related to other multiblock methods. Multiblock modeling methods provide to the user a large spectrum of interpretation indices for the investigation of the relationships among variables and among datasets. They are related to the criterion to maximize and therefore directly derived from the maximization problem under consideration. The interest of multiblock Redundancy Analysis and the associated interpretation tools are illustrated using a dataset in the field of veterinary epidemiology. Copyright © 2011 John Wiley & Sons, Ltd.
Dissimilarity representation on functional spectral data for classification
Authors: Porro‐Muñoz Diana , Talavera Isneri , Duin Robert P. W. , Hernández Noslen , Orozco‐Alzate Mauricio
Published: April 2011

In chemometrics, spectral data are typically represented by vectors of features in spite of the fact that they are usually plotted as functions of e.g. wavelengths and concentrations. In the representation, this functional information is thereby not reflected. Consequently, some characteristics of the data that can be essential for discrimination between samples of different classes or any other analysis are ignored. Examples are the continuity between measured points and the shape of curves. In the Functional Data Analysis (FDA) approach, the functional characteristics of spectra are taken into account by approximating the data by real valued functions, e.g. splines. Another solution is the Dissimilarity Representation (DR), in which classifiers are trained in a space built by dissimilarities with training examples or prototypes of each class. Functional information may be incorporated in the definition of the dissimilarity measure. In this paper we compare the feature‐based representation of chemical spectral data with three other representations: FDA, DR defined on raw data and DR defined on FDA descriptions. We analyze the classification results of these four representations for five data sets of different types, by using different classifiers. We demonstrate the importance of reflecting the functional characteristics of chemical spectral data in their representation, and we show when the presented approaches are more suitable. Copyright © 2011 John Wiley & Sons, Ltd.
Drop‐Population Balances as Basis for the Design of Extraction Columns
Authors: Adinata Donni , Ayesterán José , Buchbender Florian , Kalem Murat , Kopriwa Nicole , Pfennig Andreas
Published: April 2011

Durch die Auslegung von Extraktionskolonnen basierend auf Experimenten im Labormaßstab und Simulationen lassen sich Zeit und Kosten sparen, da die heute üblichen, teuren Technikumsexperimente entfallen. Das Verhalten einzelner Tropfen bzw. Tropfenschwärme wird im Labormaßstab untersucht. Systemspezifische Parameter geeigneter Modelle werden an die Experimente angepasst und fließen dann in Simulationen ein, die mittels Tropfenpopulationsbilanzen den Extraktionsprozess beschreiben. Es wird eine Übersicht über die historische Entwicklung dieser Methode für die Extraktion und die heute relevanten Lösungsansätze gegeben. Das Simulationstool ReDrop kann erfolgreich das Verhalten von pulsierten Extraktionskolonnen vorhersagen und wurde mit mehreren, auch industriellen Stoffsystemen validiert. Eine Perspektive für die zukünftige Entwicklung wird aufgezeigt.
Distributed self‐organizing bandwidth allocation for priority‐based bus communication
Authors: Ziermann Tobias , Wildermann Stefan , Mühleis Nina , Teich Jürgen
Published: April 2011

The raising complexity in distributed embedded systems makes it necessary that the communication of such systems organizes itself automatically. In this paper, we tackle the problem of sharing bandwidth on priority‐based buses. Based on a game theoretic model, reinforcement learning algorithms are proposed that use simple local rules to establish bandwidth sharing. The algorithms require little computational effort and no additional communication. Extensive experiments show that the proposed algorithms establish the desired properties without global knowledge ortextita priori information. It is proven that communication nodes using these algorithms can co‐exist with nodes using other scheduling techniques. Finally, we propose a procedure that helps to set the learning parameters according to the desired behavior. Copyright © 2011 John Wiley & Sons, Ltd.
Continuous reaction crystallization of struvite from phosphate(V) solutions containing calcium ions
Authors: Hutnik N. , Piotrowski K. , Wierzbowska B. , Matynia A.
Published: April 2011

Continuous reaction crystallization of struvite from water solutions containing phosphate(V) (1.0 mass%) and calcium ions (from 0.01 to 0.20 mass%) was investigated. Process was carried out in temperature 298 K in continuous DT MSMPR type crystallizer with internal circulation of suspension. Influence of pH (from 9 to 11) and mean residence time of suspension in crystallizer (from 900 to 3600 s) on product crystal size distribution, mean size, population homogeneity and shape of crystals, as well as chemical composition of solid phase was tested. Within the investigated process parameter ranges struvite crystals of mean size from 18 to ca. 50 μm were produced. With the increase in calcium ions concentration in a feed mean crystal size decreased from 34.2 to 18.4 μm (pH 9, τ 900 s). Coexistence of struvite and hydroxyapatite crystals in the solid product was confirmed analytically (Ca content in solid product from 0.3 to 8.4 mass%). Presence of calcium ions favoured crystallization of struvite in a form of tubular crystals, characterized by lengthwise cracks and irregular edges. Co–precipitated hydroxyapatite particles showed relatively small sizes, even below 1 μm, forming agglomerates on the surface of larger struvite crystals and individual agglomerates. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generation of a tamoxifen inducible SMN mouse for temporal SMN replacement
Authors: Bebee Thomas W. , Gladman Jordan T. , Chandler Dawn S.
Published: April 2011

Proximal spinal muscular atrophy (SMA) is caused by low levels of the SMN protein, encoded by the Survival Motor Neuron genes (SMN1 and SMN2). Mouse models of SMA can be rescued by increased SMN expression, but the timing of SMN replacement for complete rescue is unknown. Studies in zebrafish predict restoration of SMN function during embryogenesis may be important for axonal pathfinding, while the mouse models and normal human disease progression suggest that post‐natal treatment may be sufficient for amelioration of disease. To evaluate the timing for SMN replacement, we have generated a stably integrated Cre‐inducible SMN mouse in which expression of full‐length SMN2 occurs after tamoxifen administration. Our temporally inducible SMN transgene is able to express SMN in embryonic, neonatal, and weanling mice and as such can be utilized in severe and mild SMA mouse models to identify the therapeutic window for SMN replacement. genesis 49:927–934, 2011. © 2011 Wiley Periodicals, Inc.
Subsets of human CD4+ regulatory T cells express the peripheral homing receptor CXCR3
Authors: Hoerning André , Koss Kerith , Datta Dipak , Boneschansker Leonard , Jones Caroline N. , Wong Ian Y. , Irimia Daniel , Calzadilla Katiana , Benitez Fanny , Hoyer Peter F. , Harmon William E. , Briscoe David M.
Published: April 2011

Regulatory T cells (Tregs) migrate into peripheral sites of inflammation such as allografts undergoing rejection, where they serve to suppress the immune response. In this study, we find that ∼30–40% of human CD25hi FOXP3+ CD4+ Tregs express the peripheral CXC chemokine receptor 3 (CXCR3) and that this subset has potent immunoregulatory properties. Consistently, we observed that proliferative responses as well as IFN‐γ production were significantly higher using CXCR3‐depleted versus undepleted responders in the mixed lymphocyte reaction, as well as following mitogen‐dependent activation of T cells. Using microfluidics, we also found that CXCR3 was functional on CXCR3pos Tregs, in as much as chemotaxis and directional persistence towards interferon‐γ‐inducible protein of 10 kDa (IP‐10) was significantly greater for CXCR3pos than CXCR3neg Tregs. Following activation, CXCR3‐expressing CD4+ Tregs were maintained in vitro in cell culture in the presence of the mammalian target of rapamycin (mTOR) inhibitor rapamycin, and we detected higher numbers of circulating CXCR3+ FOXP3+ T cells in adult and pediatric recipients of renal transplants who were treated with mTOR‐inhibitor immunosuppressive therapy. Collectively, these results demonstrate that the peripheral homing receptor CXCR3 is expressed on subset(s) of circulating human Tregs and suggest a role for CXCR3 in their recruitment into peripheral sites of inflammation.
Square Wave Stripping Voltammetry of Unlabeled Single‐ and Double‐Stranded DNAs
Authors: Bartošík Martin , Paleček Emil
Published: April 2011

We show that, in difference to previously applied electrochemical methods working with stationary electrodes, square wave voltammetry produces well‐developed peaks IISW (specific for dsDNA) and IIISW yielded by ssDNA at hanging mercury drop electrode (HMDE) and solid amalgam electrodes (SAEs). Using these peaks various kinds of DNA structural transitions can be studied, including unwinding of dsDNA at negatively charged electrode surfaces. The sensitivity of the DNA analysis is much better than that obtained with guanine oxidation signals at carbon electrodes. Both carbon electrodes and SAEs appear attractive as transducers in label‐free RNA and DNA sensors.
Understanding solution-state noncovalent interactions between xenobiotics and natural organic matter using 19F/1H heteronuclear saturation transfer difference nuclear magnetic resonance spectroscopy
Authors: Longstaffe James G , Simpson André J
Published: April 2011

A combination of forward and reverse heteronuclear (19F/1H) saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopic techniques were applied to characterize the noncovalent interactions between perfluorinated aromatic xenobiotics and dissolved humic acid. These NMR techniques produce detailed molecular-level descriptions of weak noncovalent associations between components in complex environmental mixtures, allowing the mechanisms underlying these interactions to be explored; 19F observed heteronuclear STD (H-STD) is used to describe the average molecular orientation of the xenobiotics during their interactions with humic acid, whereas 1H observed reverse-heteronuclear STD (RH-STD) is used to both identify and quantify preferences exhibited by xenobiotics for interactions at different types of humic acid moieties. First, by using H-STD, it is shown that selected aromatic organofluorides orient with their nonfluorine functional groups (OH, NH2, and COOH) directed away from humic acid during the interactions, suggesting that these functional groups are not specifically involved. Second, the RH-STD experiment is shown to be sensitive to subtle differences in preferred interaction sites in humic acid and is used here to demonstrate preferential interactions at aromatic humic acid sites for selected aromatic xenobiotics, C10F7OH, and C6F4X2, (where X = F, OH, NH2, NO2, or COOH), that can be predicted from the electrostatic potential density maps of the xenobiotic. Environ. Toxicol. Chem. 2011; 30:1745–1753. © 2011 SETAC
Investigation and application of point implicit Runge–Kutta methods to inviscid flow problems
Authors: Langer Stefan
Published: April 2011

We derive and investigate point implicit Runge–Kutta methods to significantly improve the convergence rate to approximate steady‐state solutions of inviscid flows. It turns out that the point implicit Runge–Kutta can be interpreted as a preconditioned explicit Runge–Kutta method, where the preconditioner arises naturally as local derivative of the residual function. Moreover, many preconditioners suggested in the literature so far are identified as special case of our general ansatz. Conditions will be formulated such that explicit Runge–Kutta methods with local time stepping are equivalent to point implicit methods. In numerical examples, we will demonstrate the improved convergence rates. Copyright © 2011 John Wiley & Sons, Ltd.
The modulatory influence of a predictive cue on the auditory steady‐state response
Authors: Weisz Nathan , Lecaignard Françoise , Müller Nadia , Bertrand Olivier
Published: April 2011

Whether attention exerts its impact already on primary sensory levels is still a matter of debate. Particularly in the auditory domain the amount of empirical evidence is scarce. Recently noninvasive and invasive studies have shown attentional modulations of the auditory Steady‐State Response (aSSR). This evoked oscillatory brain response is of importance to the issue, because the main generators have been shown to be located in primary auditory cortex. So far, the issue whether the aSSR is sensitive to the predictive value of a cue preceding a target has not been investigated. Participants in the present study had to indicate on which ear the faster amplitude modulated (AM) sound of a compound sound (42 and 19 Hz AM frequencies) was presented. A preceding auditory cue was either informative (75%) or uninformative (50%) with regards to the location of the target. Behaviorally we could confirm that typical attentional modulations of performance were present in case of a preceding informative cue. With regards to the aSSR we found differences between the informative and uninformative condition only when the cue/target combination was presented to the right ear. Source analysis indicated this difference to be generated by a reduced 42 Hz aSSR in right primary auditory cortex. Our and previous data by others show a default tendency of “40 Hz” AM sounds to be processed by the right auditory cortex. We interpret our results as active suppression of this automatic response pattern, when attention needs to be allocated to right ear input. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.