bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Molecular Adsorption on the Electrical Conductance of Single Au Nanowires Fabricated by Electron‐Beam Lithography and Focused Ion Beam Etching
Authors: Shi Ping , Zhang Jingying , Lin Hsin‐Yu , Bohn Paul W.
Published: October 2010

Metal nanowires are one of the potential candidates for nanostructured sensing elements used in future portable devices for chemical detection; however, the optimal methods for fabrication have yet to be fully explored. Two routes to nanowire fabrication, electron‐beam lithography (EBL) and focused ion beam (FIB) etching, are studied, and their electrical and chemical sensing properties are compared. Although nanowires fabricated by both techniques exhibit ohmic conductance, I–V characterization indicates that nanowires fabricated by FIB etching exhibit abnormally high resistivity. In addition, the resistivity of nanowires fabricated by FIB etching shows very low sensitivity toward molecular adsorption, while those fabricated by EBL exhibit sensitive resistance change upon exposure to solution‐phase adsorbates. The mean grain sizes of nanowires prepared by FIB etching are much smaller than those fabricated by EBL, so their resistance is dominated by grain‐boundary scattering. As a result, these nanowires are much less sensitive to molecular adsorption, which mediates nanowire conduction through surface scattering. The much reduced mean grain sizes of these nanowires correlate with Ga ion damage caused during the ion milling process. Thus, even though the nanowires prepared by FIB etching can be smaller than their EBL counterparts, their reduced sensitivity to adsorption suggests that nanowires produced by EBL are preferred for chemical and biochemical sensing applications.
Applying evolutionary perspective to analyse the TFT‐LCD industry development in Taiwan
Authors: Hsiao Chih‐Tung , Chang Pao‐Long , Ho Shu‐Ping
Published: October 2010

After developing thin film transistor liquid crystal display (TFT‐LCD) technology for the past 30 years, Taiwan has become the largest LCD manufacturer globally. Even under the global financial crisis in 2008, the production value of 10‐inch or larger TFT‐LCD panels in Taiwan was still up to US$28.8 billion. The development of the LCD industry is dynamic and sophisticated, and the development trajectories are influenced by the strategies of internationally based parent factories supplying technology, the industry policies of the government and the interactions of TFT‐LCD companies with both their technology providers and upstream and downstream companies. Based on their interactions, these factors generate a unique evolutionary pathway, manifested in both ‘incidental’ and ‘inevitable’ results. This study adopts a holistic and evolutionary perspective to present the structure of industrial development systems and the evolutionary model in Newly Industrialized Countries (NICs). The structure of industrial development systems and the evolutionary model are applied to explore the development process and structure of the Taiwanese TFT‐LCD industry, and to interpret the behaviour of the self‐conscious evolution. The study suggests that the Taiwanese TFT‐LCD industry has experienced three stages of evolution, namely the adaptive evolution in the first two stages and changes into the still continuous self‐conscious evolution stage at present to respond to the possible change of the environment in the future and to obtain the greatest competition chance. Copyright © 2010 John Wiley & Sons, Ltd.
Dietary Monounsaturated Fatty Acids but not Saturated Fatty Acids Preserve the Insulin Signaling Pathway via IRS‐1/PI3K in Rat Skeletal Muscle
Authors: Moon Jae Hoon , Lee Ji Young , Kang Saet Byol , Park Jong Suk , Lee Byung Wan , Kang Eun Seok , Ahn Chul Woo , Lee Hyun Chul , Cha Bong Soo
Published: October 2010

Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) show different effects on the development of insulin resistance. In this study, we compared the effect of dietary SFA and MUFA on the insulin signaling pathway in the skeletal muscle of a type 2 diabetic animal model. Twenty‐nine‐week‐old male Otsuka Long‐Evans Tokushima fatty (OLETF) rats were randomly divided into three groups and fed one of the following diets for 3 weeks; a normal chow diet, an SFA (lard oil) enriched or a MUFA (olive oil) enriched high‐fat diet. The vastus lateralis muscle was used for analyses. Insulin tolerance test showed improved insulin sensitivity in rats fed the MUFA diet, as compared to those fed the SFA diet (p < 0.001). The SFA diet reduced IRS‐1 expression and phosphorylated PI3K levels in skeletal muscle, as compared with a chow diet (p < 0.001, respectively). On the contrary, muscle IRS‐2 expression and phosphorylated ERK1/2 was significantly increased in rats fed the SFA diet (p < 0.001, respectively). Membrane translocation of glucose transporter type 4 decreased in the skeletal muscle of rats fed the SFA diet, as compared to those fed a chow diet (p < 0.001). These changes in insulin signaling pathway in skeletal muscle were not observed in rats fed the MUFA diet. In conclusion, the beneficial effect of dietary MUFA on insulin sensitivity is associated with a conserved IRS‐1/PI3K insulin signaling pathway which was altered by dietary SFA.
Camelina sativaOil Deodorization: Balance Between Free Fatty Acids and Color Reduction and Isomerized Byproducts Formation
Authors: Hrastar Robert , Cheong Ling‐Zhi , Xu Xuebing , Miller Rasmus Leth , Košir Iztok Jože
Published: October 2010

Camelina sativaoil is characterized by its high content (up to 40 wt%) of α‐linolenic acid and its unique flavor. It is considered to have beneficial health properties and is suitable for food and cosmetic uses. In the present study, response surface methodology was used to optimize processing parameters for bench‐scale deodorization of camelina oil. The mathematical models generated described the effects of process parameters (temperature, steam flow, time) on several deodorization quality indicators: free fatty acids (FFA),transfatty acids (TFA), color, and polymerized triglycerides (PTG). These newly established models can be used as a tool to identify optimum deodorization process conditions within chosen constraints. Based on the optimization of minimum retained FFA with the constraint of a maximum allowable TFA, deodorization parameters can be defined. At a constant steam flow rate of 42 ml/h, a temperature range of 210–220 °C, and deodorization time of 70–120 min were defined. 220 °C appears to be a critical upper temperature limit; above this temperature, isomerization rates significantly increase.
Enzyme Treatments to Enhance Oil Recovery from Condensed Corn Distillers Solubles
Authors: Majoni Sandra , Wang Tong , Johnson Lawrence A.
Published: October 2010

The objective of this study was to determine the effect of enzyme hydrolysis of various corn components on oil recovery from condensed corn distillers solubles (CCDS). Hydrolysis with a commercial protease significantly increased oil recovery as the enzyme concentration increased, with the greatest oil recovery being 70% at 10% v/w (dry weight basis) enzyme concentration. Increasing centrifugal force from 8,500 to 12,240×g was only slightly effective for the non‐enzyme treated samples. Reducing CCDS particle size by grinding with a mortar and pestle increased oil recovery to 83% when an enzyme combination of a commercial cellulase mixture and a protease was used. Particle size reduction of CCDS by high‐speed blending resulted in low oil recovery, but the oil recovery was significantly improved after enzyme treatment. Zein‐lipid interaction was very strong when tested in a model system, with only 10% of the oil being freed by centrifugation alone. Following enzyme hydrolysis of the zein‐oil complex with a protease, oil recovery was increased to 97%. Overall, enzyme hydrolysis and further particle size reduction showed a small, albeit statistically significant, effect in increasing oil recovery from CCDS. These small increases may not justify the use of enzymes or processing modifications to reduce particle size in the ethanol industry, nonetheless, these data may provide a reference or insight to design more effective treatments for oil recovery.
Regionale Bildungsdisparitäten und Beschäftigungsentwicklung
Authors: Tarazona Mareike
Published: October 2010

Education plays a major role for an economy’s growth in economic analysis and theory. However, international studies about the relation between education and economic growth lack valid and comparable data. In studies about regional development, education has received only limited attention. This study analyses the relation between education and employment growth in Germany, and compares various education variables. A regression across 97 German planning regions reveals that the development of several education variables, the capital stock and the working age population demonstrate highly significant coefficients for explaining the development of employment. In particular, a human capital index that includes formal qualification levels of all employees makes a strong explanatory contribution. Furthermore, the study reveals that regional educational disparities increase significantly over time and therefore contribute to a divergent employment development.
Children playing branded video games: The impact of interactivity on product placement effectiveness
Authors: Hang Haiming , Auty Susan
Published: October 2010

This study extends product placement research by testing the impact of interactivity on product placement effectiveness. The results suggest that when children cannot interact with the placements in video games, perceptual fluency is the underlying mechanism leading to positive affect. Therefore, the effects are only evident in a stimulus‐based choice where the same stimulus is provided as a cue. However, when children have the opportunity to interact with the placements in video games, they may be influenced by conceptual fluency. Thus, placements are still effective in a memory‐based choice where no stimulus is provided as a cue.
Quasi-two-dimensional properties of a single shallow-water vortex with high initial Reynolds numbers
Authors: SEOL D.-G. , JIRKA G. H.
Published: October 2010

The evolution and dynamics of a shallow-water vortex system with high initial Reynolds numbers are investigated experimentally without background rotation. A single vortex is generated by rotating a water mass at the centre of an experimental tank using a bottomless cylinder with internal sectors. The surface velocity field is observed via particle image velocimetry. The experimentally observed vorticity fields indicate that strong shallowness (the ratio of the cylinder diameter to the water depth) and high Reynolds number contribute to the formation of large-scale coherent structures in the form of a tripolar vortex system. The shallow-water vortices with high initial Reynolds numbers experience the transition from turbulent to laminar regimes in their decay process. The proposed first-order vortex decay model predicts that a shallow-water vortex decays as t−1 in the initial turbulent stage and as e−t in the later laminar stage due to horizontal diffusion and bottom friction. The estimated transition time scale from the turbulent to laminar stage increases with initial vortex Reynolds number and with shallowness. By taking the vortex expansion into consideration, the second-order vortex decay model is also presented. The azimuthally ensemble-averaged data elucidate effects of the vortex instabilities and of turbulent energy transfer on the formation of large-scale coherent flow structures. Normal mode analysis of the vortex systems is conducted to study the effect of shallowness and Reynolds number on the generation of two-dimensional large-scale coherent structures. The results show that the perturbation wavenumber of mode 2 is the fastest-growing instability in shallow-water conditions, and its effect depends on initial Reynolds number and shallowness.
DNS study of decaying homogeneous isotropic turbulence with polymer additives
Authors: CAI W.-H. , LI F.-C. , ZHANG H.-N.
Published: October 2010

In order to investigate the turbulent drag reduction phenomenon and understand its mechanism, direct numerical simulation (DNS) was carried out on decaying homogeneous isotropic turbulence (DHIT) with and without polymer additives. We explored the polymer effect on DHIT from the energetic viewpoint, i.e. the decay of the total turbulent kinetic energy and energy distribution at each scale in Fourier space and from the phenomenological viewpoint, i.e. the alterations of vortex structures, the enstrophy and the strain. It was obtained that in DHIT with polymer additives the decay of the turbulent kinetic energy is faster than that in the Newtonian fluid case and a modification of the turbulent kinetic energy transfer process for the Newtonian fluid flow is observed due to the release of the polymer elastic energy into flow structures at certain small scales. Besides, we deduced the transport equations of the enstrophy and the strain, respectively, for DHIT with polymer additives. Based on the analyses of these transport equations, it was found that polymer additives depress both the enstrophy and the strain in DHIT as compared to the Newtonian fluid case, indicating the inhibition effect on small-scale vortex structures and turbulence intensity by polymers.
Comparison of vestibular evoked myogenic potentials elicited by click and short duration tone burst stimuli
Authors: Kumar K , Sinha S Kumar , Bharti A Kumar , Barman A
Published: October 2010

Introduction:

Vestibular evoked myogenic potentials are short latency electrical impulses that are produced in response to higher level acoustic stimuli. They are used clinically to diagnose sacculocollic pathway dysfunction.

Aim:

This study aimed to compare the vestibular evoked myogenic potential responses elicited by click stimuli and short duration tone burst stimuli, in normal hearing individuals.

Method:

Seventeen subjects participated. In all subjects, we assessed vestibular evoked myogenic potentials elicited by click and short duration tone burst stimuli.

Results and conclusion:

The latency of the vestibular evoked myogenic potential responses (i.e. the p13 and n23 peaks) was longer for tone burst stimuli compared with click stimuli. The amplitude of the p13–n23 waveform was greater for tone burst stimuli than click stimuli. Thus, the click stimulus may be preferable for clinical assessment and identification of abnormalities as this stimulus has less variability, while a low frequency tone burst stimulus may be preferable when assessing the presence or absence of vestibular evoked myogenic potential responses.
Independent Transversals in Sparse Partite Hypergraphs
Authors: Erdős Paul , Gyárfás András , Łuczak Tomasz
Published: October 2010

An [n, k, r]-hypergraph is a hypergraph = (V, E) whose vertex set V is partitioned into n k-element sets V1, V2,…, Vn and for which, for each choice of r indices, 1 ≤ i1 < i2 < … < ir ≤ n, there is exactly one edge e ∈ E such that |e∩Vi| = 1 if i ∈ {i1, i2.…, ir} and otherwise |e ∩ Vi| = 0. An independent transversal of an [n, k, r]-hypergraph is a set T = {a1, a2,…, an} ⊆ V such that ai ∈ Vi for i = 1, 2, …, n and e ⊈ T for all e ∈ E. The purpose of this note is to estimate fr(k), defined as the largest n for which any [n, k, r]-hypergraph has an independent transversal. The sharpest results are for r = 2 and for the case when k is small compared to r.
Ks-Free Graphs Without Large Kr-Free Subgraphs
Authors: Krivelevich Michael
Published: October 2010

The main result of this paper is that for every 2 ≤ r < s, and n sufficiently large, there exist graphs of order n, not containing a complete graph on s vertices, in which every relatively not too small subset of vertices spans a complete graph on r vertices. Our results improve on previous results of Bollobás and Hind.
Obstructions for the Disk and the Cylinder Embedding Extension Problems
Authors: Mohar Bojan
Published: October 2010

LetSbe a closed surface with boundary ∂Sand letGbe a graph. LetK⊆Gbe a subgraph embedded inSsuch that ∂S⊆K. Anembedding extensionofKtoGis an embedding ofGinSthat coincides onKwith the given embedding ofK. Minimal obstructions for the existence of embedding extensions are classified in cases whenSis the disk or the cylinder. Linear time algorithms are presented that either find an embedding extension, or return an obstruction to the existence of extensions. These results are to be used as the corner stones in the design of linear time algorithms for the embeddability of graphs in an arbitrary surface and for solving more general embedding extension problems.
Propofol as a bridge to extubation for high-risk children with congenital cardiac disease
Authors: Teng Sarena N. , Kaufman Jon , Czaja Angela S. , Friesen Robert H. , da Cruz Eduardo M.
Published: October 2010

Background

Children with congenital cardiac defects may have associated chromosomal anomalies, airway compromise, and/or pulmonary hypertension, which can pose challenges to adequate sedation, weaning from mechanical ventilation, and successful extubation. Propofol, with its unique properties, may be used as a bridge to extubation in certain cardiac populations.

Materials and methods

We retrospectively reviewed 0–17-year-old patients admitted to the Cardiac Intensive Care Unit between January, 2007 and September, 2008, who required mechanical ventilation and received a continuous infusion of propofol as a bridge to extubation. Medical charts were reviewed for demographics, associated comorbidities, as well as additional sedation medications and haemodynamic trends including vital signs and vasopressor support during the peri-infusion period. Successful extubation was defined as no re-intubation required for respiratory failure within 48 hours. Outcomes measured were successful extubation, evidence for propofol infusion syndrome, haemodynamic stability, and fluid and inotropic requirements.

Results

We included 11 patients for a total of 12 episodes. Propofol dose ranged from 0.4 to 5.6 milligram per kilogram per hour with an average infusion duration of 7 hours. All patients were successfully extubated, and none demonstrated worsening metabolic acidosis suggestive of the propofol infusion syndrome. All patients remained haemodynamically stable during the infusion with average heart rates and blood pressures remaining within age-appropriate ranges. One patient received additional fluid but no increase in vasopressors was needed.

Conclusions

This study suggests that propofol infusions may allow for successful extubation in a certain population of children with congenital cardiac disease. Further studies are required to confirm whether propofol is an efficient and safe alternative in this setting.
Concrete Review as Indirect Constitutional Complaint in French Constitutional Law: A Comparative Perspective
Authors: Pfersmann Otto
Published: October 2010

1958: a priori review of parliamentary legislation to keep Parliament within its limited legislative competences – 2008: a posteriori review to protect citizens' rights and freedoms – Varieties of concrete review – Originality of the new French procedure – An indirect constitutional complaint: raised by a litigating party, transmitted by an ordinary court and decided by the Constitutional Council – Obstacle to transmission: declaration of conformity in the motives of an earlier decision by Constitutional Council – Conceptual, logical and legal reasons for a strict distinction between normative content and justificatory discourse in judgments – Setting on par of motives and operative part transforms French legal system into a specific form of common law and weakens the Rule of Law
Irish Music and Musicians in the United States: An Introduction
Authors: WELLS PAUL F. , SOMMERS SMITH SALLY K.
Published: October 2010

“The Irish came early and often to America,” quipped musicologist Charles Hamm in his landmark book Yesterdays: Popular Song in America. Although the largest waves of immigration occurred during the years of the potato famines in the 1840s and 1850s, the process began long before then and continues to the present day, albeit with many ebbs and flows in the stream. Today nearly 36.5 million people in the United States claim Irish ancestry.
'Tis Like They Never Left: Locating “Home” in the Music of Sliabh Aughty's Diaspora
Authors: COLLINS TIM
Published: October 2010

This article, which builds on research in the fields of Irish traditional music, place, and diaspora, focuses on a community of diasporic musicians from Sliabh Aughty, an upland region of approximately 250 square miles that encompasses the musical storehouses of east Clare and southeast Galway in the West of Ireland. It examines the importance of home for these musicians, who have been resident in the United States for many decades. Their personal music geographies are explored to ascertain how traditional Irish music plays a critical role in transcending their sense of dislocation and reconnecting them with “home.”
Mantle transition zone topography and structure beneath the central Tien Shan orogenic belt
Authors: Tian Xiaobo , Zhao Dapeng , Zhang Hongshuang , Tian You , Zhang Zhongjie
Published: October 2010

In this study we calculated receiver functions (RFs) from teleseismic P waveforms recorded by stations of four seismic networks to determine the topography of the mantle transition zone (MTZ) beneath the central Tien Shan. We converted the RFs from the time domain to the depth domain and selected the depths of 410 and 660 km discontinuities after stacking the RFs in narrow raypath bins. To better determine the MTZ topography, we applied an updated RF method to invert the depth differences between the 410 and 660 km discontinuities in each RF for lateral depth variations of the two discontinuities. Using this approach, we detected several anomalies in the 410 and 660 km discontinuity depths beneath the central Tien Shan region. Extensive synthetic tests were carried out to confirm the main features of the result. Beneath the south and east of Lake Issyk‐Kul, the 410 km discontinuity becomes shallower while the 660 km discontinuity becomes deeper, leading to a thicker MTZ with a lower temperature, possibly caused by pieces of thickened lithosphere dropping down to at least the bottom of the MTZ. Beneath the northwest of Lake Issyk‐Kul, the 410 km discontinuity becomes deeper while the 660 km discontinuity becomes shallower, resulting in a thinner MTZ with a higher temperature, which may reflect a small‐scale hot upwelling from the lower mantle.
Seasonal variation of the concentrations of nitrogenous species and their nitrogen isotopic ratios in aerosols at Gosan, Jeju Island: Implications for atmospheric processing and source changes of aerosols
Authors: Kundu Shuvashish , Kawamura Kimitaka , Lee Meehye
Published: October 2010

Atmospheric aerosol samples (n = 84) were collected at Gosan site, Jeju Island, South Korea between April 2003 and April 2004 for the measurements of total nitrogen (TN) and its isotopic ratio (δ15N) as well as nitrogen species (NH4+ and NO3−). Measurements were also conducted for remained nitrogen (remained N) and removed nitrogen (removed N) on HCl fume treatment. A pronounced seasonal variation was found in the δ15N of TN, remained N (mostly NH4+), and removed N (mostly NO3−). The highest mean δ15N values of TN (+16.9‰ ± 4.5‰) and remained N (+20.2‰ ± 5.2‰) are detected in summer (June–August) whereas the lowest mean δ15N values (+12.9‰ ± 3.4‰ and +11.3‰ ± 5.1‰, respectively) are in winter (December–February). These trends can partly be explained by an enhanced contribution of 15N‐enriched emissions from agricultural straw burning in China in a harvest season (summer and autumn). The mean δ15N of removed N showed an opposite trend: the lowest (+8.9‰ ± 3.7‰) in warm season (March–August) and the highest (+14.1‰ ± 3.7‰) in cold season (September–February). These results can be explained by changes in source regions and emission strengths of nitrogenous species, as well as difference in secondary aerosol nitrogen formation between warm and cold seasons. Higher ratios of Ca2+/Na+ and the lowest ratios of Na+/(Cl− + NO3−) are associated with lower δ15N values of removed N as a result of less isotopic enrichment (ɛproduct‐reactant) during the reaction between HNO3 and dust particles. This study proposes that 15N/14N ratio can be regarded as process tracer of nitrogenous species in the atmosphere.
Landslide‐generated tsunamis at Réunion Island
Authors: Kelfoun Karim , Giachetti Thomas , Labazuy Philippe
Published: October 2010

Landslides that occur on oceanic volcanoes can reach the sea and trigger catastrophic tsunamis. Réunion Island has been the location of numerous huge landslides involving tens to hundreds of cubic kilometers of material. We use a new two‐fluid (seawater and landslide) numerical model to estimate the wave amplitudes and the propagation of tsunamis associated with landslide events on Réunion Island. A 10 km3 landslide from the eastern flank of Piton de la Fournaise volcano would lift the water surface by about 150 m where it entered the sea. The wave thus generated would reach Saint‐Denis, the capital of Réunion Island (population of about 150,000 people), in only 12 min, with an amplitude of more than 10 m, and would reach Mauritius Island in 18 min. Although Mauritius is located about 175 km from the impact, waves reaching its coast would be greater than those for Réunion Island. This is due to the initial shape of the wave, and its propagation normal to the coast at Mauritius but generally coast‐parallel at Réunion Island. A submarine landslide of the coastal shelf of 2 km3, would trigger a ∼40 m high wave that would severely affect the proximal coast in the western part of Réunion Island. For a landslide of the shelf of only 0.5 km3, waves of about 2 m in amplitude would affect the proximal coast.
A model for the simulation of coupled flow‐bed form evolution in turbulent flows
Authors: Chou Yi‐Ju , Fringer Oliver B.
Published: October 2010

We develop a three‐dimensional numerical model to simulate bed form dynamics in a turbulent boundary layer. In the numerical model, hydrodynamics is solved in a moving generalized boundary‐fitted curvilinear coordinate system, such that the domain boundary exactly follows complex time‐dependent bed form geometry. The resolved turbulent features are computed via large‐eddy simulation, while the subgrid scale turbulent motions are modeled with a dynamic mixed model. A second‐order accurate arbitrary Lagrangian‐Eulerian method is used to guarantee conservation of sediment mass, while the grid moves arbitrarily due to the motion of the bed. Transport of suspended load is modeled using the Eulerian approach with a pickup function as the bottom boundary condition for sediment entrainment at the bed. Transport of bed load and suspended load are combined in a mass balance equation for the bed, which evolves due to the spatiotemporally varying bed stress induced by the turbulent flow field above the bed and gravity (gravity‐induced avalanche flow). Motion of the bed in turn affects the flow field in a coupled hydrodynamic moving bed simulation, in which bed features evolve due to resolved details of the turbulent flow. We compare different bed elevation models and demonstrate the capability of the present model through simulation of sand ripple formation and evolution induced by turbulence in an oscillatory flow. A resolution study demonstrates the need for fine grid resolution to resolve a bulk of the near‐wall turbulence, which is essential for bed form initiation.
A study of Asian dust plumes using satellite, surface, and aircraft measurements during the INTEX‐B field experiment
Authors: Logan Timothy , Xi Baike , Dong Xiquan , Obrecht Rebecca , Li Zhanqing , Cribb Maureen
Published: October 2010

Asian dust events occur frequently during the boreal spring season. Their optical properties have been analyzed by using a combination of source region (ground‐based and satellite) and remote Pacific Ocean (aircraft) measurements during the Intercontinental Chemical Transport Experiment‐Phase B (INTEX‐B) field campaign which lasted from 7 April to 15 May 2006. A strong dust event originating from the Gobi Desert and passing over the Xianghe surface site on 17 April 2006 has been extensively analyzed. The surface averaged aerosol optical depth (AOD) values increased from 0.17 (clear sky) to 4.0 (strong dust), and the Angström exponent (α) dropped from 1.26 (clear sky) to below 0.1. Its total downwelling SW flux over the Xianghe site (thousands of kilometers away from the dust source region) is only 46% of the clear‐sky value with almost no direct transmission and nearly double the diffuse SW clear‐sky value. This event was also captured 6 days later by satellite observations as well as the UND/NASA DC‐8 aircraft over the eastern Pacific Ocean. The DC‐8 measurements in the remote Pacific region further classified the plumes into dust dominant, pollution dominant, and a mixture of dust and pollution events. HYSPLIT backward trajectories not only verified the origins of each case we selected but also showed (1) two possible origins for the dust: the Gobi and Taklimakan deserts; and (2) pollution: urban areas in eastern China, Japan, and other industrialized cities east of the two deserts. Based on the averaged satellite retrieved AOD data (0.5° × 0.5° grid box), declining AOD values with respect to longitude demonstrated the evolution of the transpacific transport pathway of Asian dust and pollution over the period of the field campaign.
Antigen‐driven T‐cell repertoire selection during adaptive immune responses
Authors: Baumgartner Christina K , Malherbe Laurent P
Published: October 2010

Protective immunity against a variety of infections depends on the amplification and differentiation of rare naïve antigen‐specific CD4 and CD8 T cells. Recent evidence indicates that the clonotypic composition of the responding T‐cell compartment has a critical role in the immune defense against pathogens. The present review compares and contrasts how naive CD4 and CD8 T cells recognize their cognate antigen, and discusses the factors that regulate the genesis and maintenance of the CD4 and CD8 T‐cell receptor repertoire diversity.
Molecular and genetic parameters defining T‐cell clonal selection
Authors: Labrecque Nathalie , Baldwin Troy , Lesage Sylvie
Published: October 2010

Clonal selection of T cells occurs in the thymus and is responsible for generating a useful and functional repertoire of T cells. Aberrations in clonal selection result in altered T‐cell homeostasis in the secondary lymphoid organs ranging from an absence of T cells to an overabundance of autoreactive T cells. The advent of new technologies facilitating the manipulation of the mouse genome has helped refine our understanding of the molecular and genetic pathways involved in clonal selection and has also revealed a high degree of complexity. Herein, we attempt to review recent advances in thymic selection processes, achieved mostly through genetic manipulations.
Epistatic relationships reveal the functional organization of yeast transcription factors
Authors: Zheng Jiashun , Benschop Joris J , Shales Michael , Kemmeren Patrick , Greenblatt Jack , Cagney Gerard , Holstege Frank , Li Hao , Krogan Nevan J
Published: October 2010

The regulation of gene expression is, in large part, mediated by interplay between the general transcription factors (GTFs) that function to bring about the expression of many genes and site‐specific DNA‐binding transcription factors (STFs). Here, quantitative genetic profiling using the epistatic miniarray profile (E‐MAP) approach allowed us to measure 48 391 pairwise genetic interactions, both negative (aggravating) and positive (alleviating), between and among genes encoding STFs and GTFs in Saccharomyces cerevisiae. This allowed us to both reconstruct regulatory models for specific subsets of transcription factors and identify global epistatic patterns. Overall, there was a much stronger preference for negative relative to positive genetic interactions among STFs than there was among GTFs. Negative genetic interactions, which often identify factors working in non‐essential, redundant pathways, were also enriched for pairs of STFs that co‐regulate similar sets of genes. Microarray analysis demonstrated that pairs of STFs that display negative genetic interactions regulate gene expression in an independent rather than coordinated manner. Collectively, these data suggest that parallel/compensating relationships between regulators, rather than linear pathways, often characterize transcriptional circuits.
Impact of translational error‐induced and error‐free misfolding on the rate of protein evolution
Authors: Yang Jian‐Rong , Zhuang Shi‐Mei , Zhang Jianzhi
Published: October 2010

What determines the rate of protein evolution is a fundamental question in biology. Recent genomic studies revealed a surprisingly strong anticorrelation between the expression level of a protein and its rate of sequence evolution. This observation is currently explained by the translational robustness hypothesis in which the toxicity of translational error‐induced protein misfolding selects for higher translational robustness of more abundant proteins, which constrains sequence evolution. However, the impact of error‐free protein misfolding has not been evaluated. We estimate that a non‐negligible fraction of misfolded proteins are error free and demonstrate by a molecular‐level evolutionary simulation that selection against protein misfolding results in a greater reduction of error‐free misfolding than error‐induced misfolding. Thus, an overarching protein‐misfolding‐avoidance hypothesis that includes both sources of misfolding is superior to the translational robustness hypothesis. We show that misfolding‐minimizing amino acids are preferentially used in highly abundant yeast proteins and that these residues are evolutionarily more conserved than other residues of the same proteins. These findings provide unambiguous support to the role of protein‐misfolding‐avoidance in determining the rate of protein sequence evolution.
Exchanging Experimental Kinetic Data via SabioML
Authors: Golebiewski Martin
Published: October 2010

The simulation of quantitative biochemical models not only requires qualitative information about the stoichiometry of the described networks, but also kinetic data describing their dynamics. Such kinetic data have to be experimentally measured, collected, systematically structured and stored to finally make them accessible. However, the dataflow from the experiment to the model is still a bottleneck, calling for systems that capture the data directly from the instrument, process and normalize it to agreed standards and finally transfer the data to publicly available databases.SABIO-RK (http://sabio.h-its.org) is a curated database system which we have developed for bundling data referring to biochemical reactions and their kinetics. It offers data for metabolic pathways and as a novelty also for signalling reactions. Until recently, the database solely has been compiled through manual data mining of published papers and merging the kinetic data excerpt with information collected from other databases. We have designed the novel XML-based schema SabioML for exchanging experimentally derived kinetic data and corresponding metadata between programs or databases. The schema is tailored to SABIO-RK, however also could serve for transferring data between other resources. It comprises the description of kinetic laws with their parameters and relevant metadata in a structured and standardised format applying controlled vocabulary, as well as the possibility to assign annotations complying with the MIRIAM standard (Minimum Information Required In the Annotation of Models). Based on this data description format we have developed a submission interface that allows transfer of reaction kinetics data directly from the experimental instrument to the SABIO-RK database. The data can be accessed by the submitting researcher and, after release by the submitter and curation to ensure completeness of the data, also by the public, either manually via a web-based user interface or automated via web-services, both supporting the export of the data together with its annotations in SBML (Systems Biology Mark-up Language).The system introduced here considerably facilitates the exchange of kinetic data between experimentalists and modelers. We are convinced that in systems biology it will become quite useful for the integration of the results of high throughput assays into biochemical computer models for simulation.

References:

Swainston N, Golebiewski M, et al., FEBS Journal 277(18): 3769-3779 (September 2010)Rojas I, Golebiewski M, et al., In Silico Biology 7(2 Suppl): S37-44 (2007)
Progress report: SBML Level 3 package FBA
Authors: Olivier Brett , Bergmann Frank
Published: October 2010

The SBML Level 3 "FBA" package is a proposal for an extension to the current Level 3 Core specification that allows for the description and annotation of constraint based models.This allows one to e.g. store information related to flux balance analysis in SBML Level 3 models.
Potential of Multilayer Ceramics for Micro Fuel Cells
Authors: Stelter Michael
Published: October 2010

Multilayer ceramics are a promising new material class that allows the integration of complex micro fuel cells in highly robust, monolithic, functionalised ceramic blocks. In this article, the material properties, manufacturing technologies and selected application examples are described.
Large Auxiliary Power Units for Vessels and Airplanes
Authors: Peters Ralf , Westenberger Andreas
Published: October 2010

Electricity requirements in mobile applications are increasing in nearly all forecasts for the future by electric devices for more comfort and a guaranteed energy supply during idling mode. Today combustion engines and turbo jet engines were applied as auxiliary power units (APU) on-board of air planes and ocean-going vessels. Fuel cells are envisaged as an environmental friendly and high efficient energy conversion system for future systems. The ideal energy carrier for fuel cells is hydrogen. The availability of hydrogen is a prerequisite for the use of fuel cells in mobile and stationary applications. However, an infrastructure for hydrogen as a future energy carrier does not yet exist. It is therefore essential that hydrogen be produced from readily available energy carriers. Usually for logistical reasons, APUs should use the same fuel as the main engine. This will be kerosene or JET A-1 for air planes and diesel or marine gas oil for vessels.

This contribution will show the requirements of for aeronautic and maritime applications and will give an overview about today's developments in fuel cell technology and fuel processing. The targeted power class of large APUs for these applications is higher than 400 – 500 kWe. Especially for aeronautic applications two system concepts were compared for long and short range missions with hydrogen and JET A-1 as fuel. The application of kerosene-based fuel cell APUs for long-range missions could be preferable due to the lower volume required for the complete multifunctional system, the usage of the existing infrastructure, a short- to medium-term CO2 reduction and a gradual switch to biofuels. Short-range missions require a low system mass which lead to the preference of hydrogen-based HT-PEFCs.
Going Beyond Hydrogen: Non-hydrogen Fuels, Re-oxidation and Impurity Effects on Solid Oxide Fuel Cell Anodes
Authors: Cassidy Mark , Ouweltjes Jan Pieter , Dekker NiCo
Published: October 2010

Solid Oxide Fuel Cells allow for relatively easy integration of fuel processing with existing hydrocarbon fuels. This opens the possibility that this technology could offer the bridge between the existing fuel supply structure and new energy frameworks based on alternative sources of fuel. Based on an extensive literature review, issues and possible solutions related to the use of complex fuels in SOFCs are discussed. The first part of this book chapter provides insight in the conversion of lighter hydrocarbons, as well as more complex higher hydrocarbons, and solid fuel sources such as coal. Then, the impact of many of the involved fuel contaminants on the fuel cell performance are discussed, and possible solutions are provided to improve the lifetime of the fuel cell. Finally, the use of other alternative fuels are discussed, i.e. ammonia and hydrogen sulphide.
Hydrogen Production by Internal Reforming Fuel Cells
Authors: Hemmes Kas
Published: October 2010

Internal reforming fuel cells have been developed based on the Molten Carbonate Fuel Cell as well as on the Solid Oxide Fuel Cell. In these concepts effective use is made of the high temperature of the fuel cell and the surplus of heat produced by the fuel cell. The high temperature allows the reforming of hydrocarbons to hydrogen by a reaction with steam. This is an endothermic reaction consuming part of the (waste) heat produced in the fuel cell, which thereby increases the fuel cell's efficiency. The capability of internal reforming fuel cells to reform hydrocarbons can be exploited further by producing more hydrogen than necessary for their own consumption.This can be done by decreasing electric power output or by increasing the input of hydrocarbons. By producing hydrogen the Nernst loss of the fuel cell decreases since also the area near the fuel exit still contains a high partial pressure of hydrogen contrary to standard operation. Total efficiency in terms of hydrogen and power output can reach 95% as was shown by flowsheet calculations. Furthermore since waste heat can be converted into hydrogen the fuel cell can be operated in higher power density compared to standard operation and still obtain relatively high efficiencies in terms of hydrogen and power production. Overall a very flexible system is obtained in which operation can be optimized depending on (local) demand and market prices for power, hydrogen and heat.

A very interesting but more exotic form of hydrogen production using fuel cells is a concept in which carbon is electrochemically converted into carbon monoxide and subsequently reacted with steam to form carbon dioxide and hydrogen in the well known shift reaction. The electrochemical reaction takes place in a Direct Carbon Fuel Cell operated at high temperature to promote the formation of CO above CO2 following the temperature dependance of the Boudouard equilibrium.

The reaction is characterized by a negative enthalpy change and a positive entropy change. Therefor the reversible electrochemical reaction is endothermic and next to chemical energy also heat is converted into electric power. The conversion process can be called ‘electrochemical gasification’ and is a true Multi Source Multi Product conversion system in which chemical energy and heat are converted into electric power and CO (to hydrogen).
Products, Not Technology: Some Thoughts on Market Introduction Processes
Authors: Steinberger-Wilckens Robert
Published: October 2010

Fuel cells today are on the verge of market entry. Tremendous technological progress has been made in the past years and the general focus in fuel cell development has been on testing fuel cell components and systems, proving their technology readiness level and adjusting the performance to the requirements of first (niche) markets. Nevertheless, in a consumer market, technology is rarely bought as such, but in the form of a consumer product or appliance. The article therefore looks into the ways new technologies enter the market and what factors influence success and failure of market entry. The fixation on technological progress is acceptable in the early phases of technology development, but general market introduction needs more than this, especially when the main benefit of a new technology concerns environmental aspects. Fuel cells have to be increasingly seen from the point of view of the consumer and offer attractive and intriguing properties in their applications.
Organocatalytic Enantioselective Conjugate Addition Reactions
Authors: Vicario Jose L , Badia Dolores , Carrillo Luisa , Reyes Efraim
Published: October 2010

This book, unique in its field, is a comprehensive description of all the methodologies reported for carrying out conjugate addition reactions in a stereoselective way, using small chiral organic molecules as catalysts (organocatalysts). In the last 3-4 years, this has been a rapidly growing field in organic chemistry, and many papers have appeared reporting excellent protocols for carrying out these highly efficient transformations that compete well with other classical approaches using transition metal catalysts. A particularly attractive feature of this transformation relies upon the fact that the conjugate addition (Michael and Hetero-Michael reactions) is an extraordinarily effective means to initiate cascade processes which result in the formation of complex molecules from very small and simple starting blocks. The book, written by noted experts, covers all recent advances in this hot topic, and provides a good state-of-the-art review for organic chemists working in this field and all those who wish to start projects in this area.
The Central Dogma in Molecular Biology
Authors: Mahmoudian Laili
Published: October 2010

The central dogma tells that the genetic information coded by DNA molecules, first transferred to RNA molecules as intermediated molecules, is then transferred to protein molecules. In other words it says that the genetic information is saved as sequences of nucleic acids but the function has to be expressed in the form of proteins. There are three steps in the conversion of the genetic information to the proteins: replication, transcription and translation. Figure 2.1 shows the principals of central dogma.
From Unicellular to Multicellular Organisms∶ Tells from Evolution and from Development
Authors: Vitalis Tania
Published: October 2010

Both evolution from unicellular to multicellular organisms and development of complex organisms from one cell to the final body plan require specific cellular features. Unicellular organisms or fertilized eggs are virtually pluripotent. As body plans complexify and pluricellularity emerges cells will become specified and more and more differentiated and they will have to realise specific tasks. Therefore, organisms will have to develop means of cell–cell communication, cells will have to maintain cohesion and adhesion between each other, organisms will have to find ways to reproduce and to repair or regenerate specific cells or tissues. We will review points that characterise this passage from unicellular to pluricellular organisms using specific examples taken from evolution and development.
Application to Cancerogenesis: Towards Targeted Cancer Therapies?
Authors: Polzer Bernhard , Klein Christoph A.
Published: October 2010

Although molecular diagnosis in cancer has advanced over the last decades translation into successful therapies of solid cancers is lagging behind. In this chapter we will provide insights into the molecular analysis of single disseminated tumour cells (DTCs) – a cell population that comprises the founder cells of lethal metastasis. Here, recent data challenge the traditional approach of using the primary tumour as the surrogate marker for the selection of adjuvant therapies and emphasize the need to understand the biology of systemic cancer progression for personalized targeted therapies.