bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical and chemical properties of the regional mixed layer of Mexico's Megapolis Part II: evaluation of measured and modeled trace gases and particle size distributions
Authors: Ochoa C. , Baumgardner D. , Grutter M. , Allan J. , Fast J. , Rappenglueck B.
Published: November 2012

Abstract. This study extends the work of Baumgardner et al. (2009) in which measurements of trace gases and particles, at a remote, high altitude mountain site, 60 km from Mexico City were analyzed with respect to the origin of the air masses. In the current evaluation, the temperature, water vapor mixing ratio (WMR), ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2) and acyl peroxy nitrate (APN) are simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. Comparisons between the model and measurements are also evaluated for particle size distributions (PSDs) of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM). The model predictions of the diurnal trends in temperature, WMR and trace gases were generally well correlated; 13 of the 18 correlations were significant at a confidence level of <0.01. Less satisfactory were the average hourly differences between model and measurements that showed predicted values within expected, natural variation for only 10 of the 18 comparisons. The model performed best when comparing with the measurements during periods when the air originated from the east. In that case all six of the parameters being compared had average differences between the model and measurements less than the expected standard deviation. For the cases when the air masses are from the southwest or west northwest, only two of the comparisons from each case showed differences less than the expected standard deviation. The differences appear to be a result of an overly rapid growth of the boundary layer predicted by the model and too much dilution. There also is more O3 being produced, most likely by photochemical production, downwind of the emission sources than is predicted by the model. The measured and modeled PSD compare very well with respect to their general shape and the diameter of the peak concentrations. The spectra are log normally distributed with most of the mass in the accumulation mode centered at 200 ± 20 nm and little observed or predicted changes with respect to the time when the RML is above the Altzomoni research station. Only the total mass changes with time and air mass origin. The invariability of average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation after six hours of aging downwind of the major sources of anthropogenic emissions in Mexico's Megapolis. This could greatly simplify parameterization in climate models although it is not known at this time if this invariance can be extended to other megacity regions.
Quantifying the uncertainty in simulating global tropospheric composition due to the variability in global emission estimates of Biogenic Volatile Organic Compounds
Authors: Williams J. E. , van Velthoven P. F. J. , Brenninkmeijer C. A. M.
Published: November 2012

Abstract. The emission of organic compounds from biogenic processes acts as an important source of trace gases in remote regions away from urban conurbations, and is likely to become more important in future decades due to the further mitigation of anthropogenic emissions that affect air quality and climate forcing. In this study we examine the contribution of biogenic volatile organic compounds (BVOCs) towards global tropospheric composition using the global 3-D chemistry transport model TM5 and the recently developed modified CB05 chemical mechanism. By comparing regional BVOC emission estimates we show that biogenic processes act as dominant sources for many regions and exhibit a large variability in the annually and seasonally integrated emission fluxes. By performing sensitivity studies we find that the contribution of BVOC species containing between 1 to 3 carbon atoms has an impact on the resident mixing ratios of tropospheric O3 and CO, accounting for ~3% and ~11% of the simulated global distribution, respectively. This is approximately a third of the cumulative effect introduced by isoprene and the monoterpenes. By examining an ensemble of 3-D global chemistry-transport simulations which adopt different global BVOC emission inventories we determine the associated uncertainty introduced towards simulating the composition of the troposphere for the year 2000. By comparing the model ensemble values against a~composite of atmospheric measurements we show that the effects on tropospheric O3 are limited to the lower troposphere (with an uncertainty between −2% to 10%), whereas that for tropospheric CO extends up to the upper troposphere (with an uncertainty of between 10 to 45%). Comparing the mixing ratios for low molecular weight alkenes in TM5 against surface measurements taken in Europe implies that the cumulative emission estimates are too low, regardless of the chosen BVOC inventory. This variability in the global distribution of CO due to BVOC emissions introduces an associated uncertainty in the tropospheric CO burden of ~11%, which impacts strongly on the oxidative capacity of the troposphere, introducing an uncertainty in the atmospheric lifetime of the greenhouse gas CH4 of ~3%. This study thus identifies the necessity of placing further constraints on non-CH4 global biogenic emission estimates in large-scale global atmospheric chemistry models.
Simulated oxygen isotopes in cave drip water and speleothem calcite in European caves
Authors: Wackerbarth A. , Langebroek P. M. , Werner M. , Lohmann G. , Riechelmann S. , Borsato A. , Mangini A.
Published: November 2012

Abstract. Interpreting stable oxygen isotope (δ18O) records from stalagmites is still one of the complex tasks in speleothem research. Here, we present a novel model-based approach, where we force a model describing the processes and modifications of δ18O from rain water to speleothem calcite (Oxygen isotope Drip water and Stalagmite Model – ODSM) with the results of a state-of-the-art atmospheric general circulation model enhanced by explicit isotope diagnostics (ECHAM5-wiso). The approach is neither climate nor cave-specific and allows an integrated assessment of the influence of different varying climate variables, e.g. temperature and precipitation amount, on the isotopic composition of drip water and speleothem calcite. First, we apply and evaluate this new approach under present-day climate conditions using observational data from seven caves from different geographical regions in Europe. Each of these caves provides measured δ18O values of drip water and speleothem calcite to which we compare our simulated isotope values. For six of the seven caves modeled δ18O values of drip water and speleothem calcite are in good agreement with observed values. The mismatch of the remaining caves might be caused by the complexity of the cave system, beyond the parameterizations included in our cave model. We then examine the response of the cave system to mid-Holocene (6000 yr before present, 6 ka) climate conditions by forcing the ODSM with ECHAM5-wiso results from 6 ka simulations. For a set of twelve European caves, we compare the modeled mid-Holocene-to-modern difference in speleothem calcite δ18O to available measurements. We show that the general European changes are simulated well. However, local discrepancies are found, and might be explained either by a too low model resolution, complex local soil-atmosphere interactions affecting evapotranspiration or by cave specific factors such as non-equilibrium fractionation processes. The mid-Holocene experiment pronounces the potential of the presented approach to analyse δ18O variations on a spatially large (regional to global) scale. Modelled as well as measured European δ18O values of stalagmite samples suggest the presence of a strong, positive mode of the North Atlantic Oscillation at 6 ka before present, which is supported by the respective modelled climate parameters.
The implications of climate change scenario selection for future streamflow projection in the Upper Colorado River Basin
Authors: Harding B. L. , Wood A. W. , Prairie J. R.
Published: November 2012

Abstract. The impact of projected 21st century climate conditions on streamflow in the Upper Colorado River Basin was estimated using a multi-model ensemble approach wherein the downscaled outputs of 112 future climate projections from 16 global climate models (GCMs) were used to drive a macroscale hydrology model. By the middle of the century, the impacts on streamflow range, over the entire ensemble, from a decrease of approximately 30% to an increase of approximately the same magnitude. Although prior studies and associated media coverage have focused heavily on the likelihood of a drier future for the Colorado River Basin, approximately 25 to 35% of the ensemble of runs, by 2099 and 2039, respectively, result in no change or increases in streamflow. The broad range of projected impacts is primarily the result of uncertainty in projections of future precipitation, and a relatively small part of the variability of precipitation across the projections can be attributed to the effect of emissions pathways. The simulated evolution of future temperature is strongly influenced by emissions, but temperature has a smaller influence than precipitation on flow. Period change statistics (i.e., the change in flow from one 30-yr period to another) vary as much within a model ensemble as between models and emissions pathways. Even by the end of the current century, the variability across the projections is much greater than changes in the ensemble mean. The relatively large ensemble analysis described herein provides perspective on earlier studies that have used fewer scenarios, and suggests that impact analyses relying on one or a few climate scenarios are unacceptably influenced by the choice of projections.
Multi-offset ground-penetrating radar imaging of a lab-scale infiltration test
Authors: Mangel A. R. , Moysey S. M. J. , Ryan J. C. , Tarbutton J. A.
Published: November 2012

Abstract. A lab scale infiltration experiment was conducted in a sand tank to evaluate the use of time-lapse multi-offset ground-penetrating radar (GPR) data for monitoring dynamic hydrologic events in the vadose zone. Sets of 21 GPR traces at offsets between 0.44–0.9 m were recorded every 30 s during a 3 h infiltration experiment to produce a data cube that can be viewed as multi-offset gathers at unique times or common offset images, tracking changes in arrivals through time. Specifically, we investigated whether this data can be used to estimate changes in average soil water content during wetting and drying and to track the migration of the wetting front during an infiltration event. For the first problem we found that normal-moveout (NMO) analysis of the GPR reflection from the bottom of the sand layer provided water content estimates ranging between 0.10–0.30 volumetric water content, which underestimated the value determined by depth averaging a vertical array of six moisture probes by 0.03–0.05 volumetric water content. Relative errors in the estimated depth to the bottom of the 0.6 m thick sand layer were typically on the order of 2%, though increased as high as 25% as the wetting front approached the bottom of the tank. NMO analysis of the wetting front reflection during the infiltration event generally underestimated the depth of the front with discrepancies between GPR and moisture probe estimates approaching 0.15 m. The analysis also resulted in underestimates of water content in the wetted zone on the order of 0.06 volumetric water content and a wetting front velocity equal to about half the rate inferred from the probe measurements. In a parallel modeling effort we found that HYDRUS-1D also underestimates the observed average tank water content determined from the probes by approximately 0.01–0.03 volumetric water content, despite the fact that the model was calibrated to the probe data. This error suggests that the assumed conceptual model of laterally uniform, one-dimensional vertical flow in a homogenous material may not be fully appropriate for the experiment. Full-waveform modeling and subsequent NMO analysis of the simulated GPR response resulted in water content errors on the order of 0.01–0.03 volumetric water content, which are roughly 30–50% of the discrepancy between GPR and probe results observed in the experiment. The model shows that interference between wave arrivals affects data interpretation and the estimation of traveltimes. This is an important source of error in the NMO analysis, but it does not fully account for the discrepancies between GPR and the moisture probes observed in the experiment. The remaining discrepancy may be related to conceptual errors underlying the GPR analysis, such as the assumption of uniform one-dimensional flow, a lack of a sharply defined wetting front in the experiment, and errors in the petrophysical model used to convert dielectric constant to water content.
Survey of KRAS, BRAF and PIK3CA mutational status in 209 consecutive Italian colorectal cancer patients
Authors: Bozzao Cristina , Varvara Dora , Piglionica Marilidia , Bagnulo Rosanna , Forte Giovanna , Patruno Margherita , Russo Silvana , Piscitelli Domenico , Stella Alessandro , Resta Nicoletta
Published: November 2012

Molecular testing for KRAS and BRAF mutations in tumor tissue is a fundamental tool to identify patients with metastatic colorectal cancer (CRC) who are eligible for anti-EGFR monoclonal antibody therapy. We here report a molecular analysis by high-resolution melting analysis and direct sequencing of KRAS, BRAF and PIK3CA hot spot mutations in 209 Italian CRC patients. One hundred and ten patients (51%) were identified who were potentially nonresponders to anti-EGFR therapy: 90/209 patients (43%) harboring KRAS mutations, 13/117 (11.1%) with the V600E BRAF mutation, and 7/209 (3.3%) with mutations in PIK3CA exon 20. The prevalence of BRAF and PIK3CA mutations was significantly higher in patients older than 65 years (p=0.014 and p=0.018), while patients with triple-negative tumors were significantly younger than mutation carriers (p=0.000011). Patients with gene mutations also showed a trend towards preferential tumor location in the colon (p=0.026). Moreover, although involving a relatively small number of samples, we report the presence of a discordant mutational profile between primary tumors and secondary lesions (3/9 patients), suggesting that it is worthwhile to test other available tissues in order to better define the efficacy of targeted therapy. Further correlations of specific clinical features with tumor mutational profile could be helpful to predict the response of CRC patients to monoclonal antibody therapy.
MicroPET/CT Imaging of [18F]-FEPPA in the Nonhuman Primate: A Potential Biomarker of Pathogenic Processes Associated with Anesthetic-Induced Neurotoxicity
Authors: Zhang Xuan , Paule Merle G. , Newport Glenn D. , Liu Fang , Callicott Ralph , Liu Shuliang , Berridge Marc S. , Apana Scott M. , Slikker William , Wang Cheng
Published: November 2012

Background. The inhalation anesthetics nitrous oxide (N2O) and isoflurane (ISO) are used in surgical procedures for human infants. Injury to the central nervous system is often accompanied by localization of activated microglia or astrocytosis at the site of injury. The tracer that targets to the peripheral benzodiazepine receptor (PBR), [18F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]-FEPPA), has been reported as a sensitive biomarker for the detection of neuronal damage/inflammation. Methods. On postnatal day (PND) 5 or 6 rhesus monkey neonates were exposed to a mixture of N2O/oxygen and ISO for 8 hours and control monkeys were exposed to room air. MicroPET/CT images with [18F]-FEPPA were obtained for each monkey 1 day, one week, three weeks, and 6 months after the anesthetic exposure. Results. The radiotracer quickly distributed into the brains of both treated and control monkeys on all scan days. One day after anesthetic exposure, the uptake of [18F]-FEPPA was significantly increased in the temporal lobe. One week after exposure, the uptake of [18F]-FEPPA in the frontal lobe of treated animals was significantly greater than that in controls. Conclusions. These findings suggest that microPET imaging is capable of dynamic detection of inhaled anesthetic-induced brain damage in different brain regions of the nonhuman primate.
Wagner's Law in Sri Lanka: An Econometric Analysis
Authors: Kesavarajah Mayandy
Published: November 2012

This study examines whether there is empirical evidence that Wagner's law holds in the Sri Lankan economy using time series annual data over the period from 1960 to 2010 for Sri Lanka, applying cointegration and error correction modeling (ECM) techniques. In particular, this study keeps a special focus to examine the validity of six versions of Wagner's hypothesis, which support the existence of long-run relationship between public expenditure and economic growth. The empirical evidence of this study indicates that while there prevail is a short-run relationship between public expenditure and economic growth, the long-run results showed no strong evidence in support of the validity of the Wagner’s law for Sri Lankan economy. Granger causality analysis also confirms this result. Therefore, the findings of this study pave to broaden this study further for a deeper understanding about the relationship between public expenditure and economic growth by giving more attention on individual items of public expenditure and by including more macroeconomic variables in the econometric model using different methodology in future.
Mango Modulates Blood Glucose Similar to Rosiglitazone without Compromising Bone Parameters in Mice Fed High Fat Diet
Authors: Edralin A. Lucas  , Angela Brown  , Wenjia Li  , Sandra K. Peterson  , Yan Wang  , Penny Perkins-Veazie  , Stephen L. Clarke  , Brenda J. Smith
Published: November 2012

Both consumption of high-fat diet and one of the commonly used pharmacological therapies for modulating blood glucose, rosiglitazone, are associated with negative effects on bone. Previously, we reported that a diet supplemented with freeze-dried mango modulated blood glucose similar to rosiglitazone in mice fed a high-fat (HF) diet. This study examined the effects of the addition of freeze-dried mango pulp or rosiglitazone to a HF diet on bone parameters in mice. Six week old male C57BL/6J mice were randomly assigned into one of five dietary treatment groups (n=8-9 mice/group): control (9.5% calories from fat), HF (58.9% calories from fat), HF+1% or 10% mango (w/w), and HF+rosiglitazone (50 mg/kg diet) for eight weeks. Bone parameters were assessed via dual energy x-ray absorptiometry and micro-computed tomography. Both the HF and HF+rosiglitazone groups had lower whole body, tibial, and vertebral bone mineral density compared to the HF+1% mango group. Trabecular bone volume, number, and separation as well as bone strength were also compromised by HF+rosiglitazone while the mango diets maintained these bone microarchitecture parameters to that observed in the control group. These results suggests that addition of mango to the diet may provide an alternative approach to modulating blood glucose without negatively affecting skeletal health, though human studies are needed to confirm these findings. Additionally, the bioactive component(s) in mango and the mechanisms by which it modulates blood glucose and exerts potentially osteoprotective benefits warrants further investigation.
Assessment of Anti-Oxidant Potency of Small Chain Glycopeptides Using DPPH Free Radical Scavenging Assay
Authors: Kandasamy Nagarajan  , Sneha Singh  ,  Taleuzzaman  , Sadaf J. Gilani  , A. Mazumder
Published: November 2012

1,1-Diphenyl-2-picryl-hydrazyl (DPPH) in-vitro assay was employed to determine the antioxidant potency of test compounds I to VII [Arg-Thr-Starch (RTStr); Ser-Arg-Lac (SRLac); Asn-Arg-Mannose (NRMs); Arg-Asn-Lac (RNLac); Arg-Thr-Lac (RTLac); His-Asn-Mannose (HNMs); Asn-His-Lac (NHLac)] using ascorbic acid as the standard drug. The percentage scavenging activity of the test drugs were determined at different concentrations and the IC50 value of the test compounds were subsequently compared with that of ascorbic acid. Among the compounds tested, compound II (SRLac) showed highest antioxidant activity with an IC50value of 14.2 mg/ml whereas compounds I (RTS), VII (NHLac) and IV (RNLac) revealed the IC50 value of 14.3 mg/ml, 14.5 mg/ml and 15.7 mg/ml, respectively when compared with ascorbic acid (IC50 = 15.8 mg/ml). All the synthesized glycopeptides were further characterized by TLC, Melting point, IR, NMR and Mass spectral datas. Based on the above results, Ser-Arg-Lac could be considered as a lead compound for the development of new antioxidant drug for prevention of human diseases.
Determination of Artepillin-C in Brazilian Propolis by HPLC with Photodiode Array Detector
Authors: Yasuhito Nobushi  , Naoki Oikawa  , Yuzo Okazaki  , Shigetoshi Tsutsumi  , Yong Kun Park  , Masahiko Kurokawa  , Ken Yasukawa
Published: November 2012

A method for the determination of artepillin-C using HPLC coupled with photodiode array (PDA) detector was developed. Artepillin-C is abundantly present in Brazilian propolis of Baccharis species origin. The chromatographic separation was performed on a Mightysil RP-18 GP II column (150 mm × 4.6 mm, 5.0 ?m; Kanto Chemical Company Limited), and column temperature was maintained at 40°C. The mobile phase was a linear gradient elution of 0.5% aqueous acetic acid (A) and acetonitrile (B) at a flow rate of 1.0 ml/min. The chromatogram was monitored at 320 nm. The calibration range of artepillin-C was 0.75-2500 ?g/ml (r2 = 0.9991). The limit of detection (LOD) and limit of quantification (LOQ) were 0.50 ?g/ml and 0.75 ?g/ml, respectively. The intra-day and inter-day precision of the assay (RSD) were in the range 1.28-5.60% and 1.45-6.75%, respectively. The artepillin-C content in Brazilian propolis is an important factor in ensuring the quality of Brazilian propolisof Baccharis species origin. This method was used to determine artepillin-C content in Brazilian propolis.
Control of information originating from Aboriginal communities: Legal and ethical contexts
Authors: Bell Catherine , Shier Caeleigh
Published: November 2012

Access to and control over data and products of research originating from, or about, Aboriginal peoples in Canada arises in multiple legal, ethical, and political contexts. This article addresses three areas frequently implicated in Canada: intellectual property, access to information, and tribunal law and policy. A review of each area demonstrates that effective responses to concerns of Aboriginal peoples in Canada require examination of a wide range of laws implicating Inuit, First Nation, and Métis intangible and tangible cultural heritage. It also underscores the present importance of contracted confidentiality and negotiated ethical and policy frameworks to secure more meaningful control over information.
Limnological Analysis of Laguna de Bay Lake at Binangonan Freshwater Station: Its Implication to Plankton Diversity
Authors: Delima Precila C. , Baldia Susan P.
Published: November 2012

Geographically located southeast of Manila, Laguna Lake is used for multiple resources such as fishery, irrigation, power generation and navigation. Recently, the lake has been considered as a source of potable water for Metro Manila. A Limnological study of the Lake was conducted to assess its present status and potential. Three sampling sites were considered in the identification of the plankton community. Plankton samples were examined at the University of Santo Tomas Biological laboratory. Plankton species were identified using the taxonomic key of Needham and Needham. The physicochemical characteristics of the water at the different sites were assessed. Temperature and pH were measured using an analytical radiometer, dissolved oxygen (DO) was computed, transparency was determined sing the secchi disc with a diameter of 26 cm; chemical oxygen demand (COD) was computed using the standard method. The results showed that sampling site 2 had the highest DO and COD. The phytoplankton Cyanobacteria like Spirullina major and Lyngbya limnetica dominated the lake. The green algae Chlorella vulgaris and Pediastrum spp. Were found to be distinct in the lake. Copepods (Copepoda spp.) are the zooplanktons observed. Laguna Lake (Binangonan Freshwater Station) has slightly basic water still suitable for aquaculture, recreation and industrial use. The lake is eutrophic.   Keywords - algae, copepods, Laguna lake, limnological study, Physicochemical analysis, phytoplanktons, zooplanktons
The Relationship of Handwriting Speed, Working Memory, Language Comprehension and Outlines to Lecture Note‐taking and Test‐taking among College Students
Authors: Peverly Stephen T. , Vekaria Pooja C. , Reddington Lindsay A. , Sumowski James F. , Johnson Kamauru R. , Ramsay Crystal M.
Published: November 2012

A previous investigation of the cognitive processes underlying note‐taking found that handwriting speed was the only significant predictor of notes, and notes were the only significant predictor of test performance. This investigation sought to extend these results by evaluating the effects of handwriting speed, language comprehension, two measures of working memory (complex span and executive attention) and an outline on note‐taking and test performance (written summary). Participants were randomly assigned to an outline or not no‐outline group (Group) to determine the effect of an outline on handwriting speed. Results from a path analysis indicated that handwriting speed, language comprehension and Group were significantly related to notes. The relationship between the independent variables and the written summary was not completely mediated by notes as in the previous investigation. Notes, Group and language comprehension were related to the written summary. The implications of the findings are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
State estimation and simultaneous unknown input and measurement noise reconstruction based on associated observers
Authors: Yang Junqi , Zhu Fanglai , Sun Xiaojie
Published: November 2012

This paper considers the problems of the state estimation and the simultaneous unknown input and measurement noise reconstruction when the observer matching condition is not satisfied. A new augmented system is constructed by introducing a new augmented state vector. An auxiliary output vector is proposed to deal with the observer matching condition issues, and a high‐order sliding mode observer is considered to get the exact estimates of both the auxiliary outputs and their derivatives in a finite time. A reduced‐order observer is developed to asymptotically estimate the system states, and a kind of reconstruction method of the new system's unknown inputs is proposed to reach the goal of reconstructing the original system's unknown input and measurement noise. Finally, a numerical simulation example is given to illustrate the effectiveness of the proposed methods. Copyright © 2012 John Wiley & Sons, Ltd.
Active fault‐tolerant attitude control for flexible spacecraft with loss of actuator effectiveness
Authors: Xiao Bing , Hu Qinglei , Friswell Michael I.
Published: November 2012

A theoretical framework for active fault‐tolerant attitude stabilization control is developed and applied to flexible spacecraft. The proposed scheme solves a difficult problem of fault‐tolerant controller design in the presence of severe partial loss of actuator effectiveness faults and external disturbances. This is accomplished by developing an observer‐based fault detection and diagnosis mechanism to reconstruct the actuator faults. Accordingly, a backstepping‐based fault‐tolerant control law is reconfigured using the reconstructed fault information. It is shown that the proposed design approach guarantees that all of the signals of the closed‐loop system are uniformly ultimately bounded. The closed‐loop performance of the proposed control strategy is evaluated extensively through numerical simulations. Copyright © 2012 John Wiley & Sons, Ltd.
Appropriating, Reclaiming and Inventing Identity Through Architecture
Authors: Derakhshani Farrokh
Published: November 2012

Local received knowledge once ensured buildings had a strong connection with their environment and the surrounding community. With rapid urbanisation and the professionalisation of design and construction, architects working internationally with a finely attuned sensibility to place and context have been able to take up the baton and take the opportunity to develop notions of locality and identity. For the last two decades, the Aga Khan Award for Architecture has been recognising the contribution of design teams that have been responsible for producing exceptional architecture for Islamic communities worldwide. Here, the award scheme's director, Farrokh Derakshani, defines some key treatments of identity in architecture.
A Reflexive Conversation: Bridge School and Liyuan Library
Authors: Xiaodong Li
Published: November 2012

Through his description of two projects in two very different regions of China, architect Li Xiaodong demonstrates how a reflexive approach that is responsive to local conditions results in buildings with contrasting personalities: the Bridge School in Fujian Province being dynamic and the Liyuan Library in Huairou County, on the outskirts of Beijing, being tranquil.
Earthworks
Authors: Mateo Josep Lluís
Published: November 2012

In historic towns and villages, topography layered by the detritus of previous structures mark out and continue to inform the identity and design of new buildings and streets. Spanish architect Josep Lluís Mateo describes two projects in his native Catalonia – one from the early 1980s for the redevelopment the medieval town of Ullastret, near Girona, and another from 2011 for a film theatre in Barcelona – that were influenced from the bottom up by the earth beneath his feet.
School in Gando, Burkina Faso
Authors: Kéré Diébédo Francis
Published: November 2012

In 2001, architect Diébédo Francis Kéré completed the design and construction of a primary school for his home village of Gando in Burkina Faso. Raising funds through an organisation in Berlin, he applied the knowledge gained through his architectural education and associates in Germany to design the school in local sustainable materials. For its realisation, he drew on valuable village resources, with the on‐site labour being undertaken by the hands of the men, women and children of Gando.
Peripatetic Infrastructure
Authors: Kirschenfeld Jonathan
Published: November 2012

Creating public works of quality and delight in the current economic climate requires unstinting commitment and astuteness on the part of the architect. Jonathan Kirschenfeld describes how he landed the project of designing a floating public swimming baths for New York City through serendipity and then hauled it in through pure determination. Likewise, it was only through immersing himself in ‘the murky world of real estate’ and collecting vacant sites from brokers, while performing zoning analyses and schematic designs, that he put his practice in line for supportive housing commissions.
Common Artefacts
Authors: Lee Christopher CM
Published: November 2012

With offices in Beijing, Mumbai and London, Serie Architects is an international practice that spans Asia. Here, co‐founder and principal Christopher CM Lee looks beyond the superficial ‘exotic’ stereotypical image of ‘orientalism’ that was traditionally imposed on Asia by the West. With particular reference to Serie Architects' Tote, Mumbai, and Yan Zhenqing Museum in Linyi, China, he shifts the question of identity to what is common within the context of architectural production: what might imbue architecture with social and cultural validity? How might it be possible to attempt to create ‘common artefacts’ through the most typical elements – the ‘dominant types’.
The Problem of Scale
Authors: Godsell Sean
Published: November 2012

Sean Godsell has built an international reputation on designing finely crafted houses in southeast Australia for which he draws all the details by hand. Here he explains how landing the commission for the Design Hub, a new postgraduate design research centre for RMIT in Melbourne, required a shift in scale and also a change in working conditions as he encountered new production processes and levels of regulation. Maintaining the character of the building as something ‘made’ rather than produced was a sustained battle.
A Pivotal Point: On the Edge of History
Authors: Buchanan Peter
Published: November 2012

Architecture critic Peter Buchanan places the current impoverishment of the built environment squarely at the feet of modernity – the modernising impulse that has characterised the last half millennium. Where, however, does this leave globalism, as a culmination of the commercial drive of the modern era, with its roots in voracious colonialism? The relevant choice is not between local tradition and global modernity. Rather, today's pressing need is for an architecture that supports a sustainable planetary culture yet to come, which transcends and supersedes modernity.
A Nonvolatile Spintronic Memory Element with a Continuum of Resistance States
Authors: Fang Yeyu , Dumas R. K. , Nguyen T. N. Anh , Mohseni S. M. , Chung S. , Miller C. W. , Åkerman Johan
Published: November 2012

A continuum of stable remanent resistance states is reported in perpendicularly magnetized pseudo spin valves with a graded anisotropy free layer. The resistance states can be systematically set by an externally applied magnetic field. The gradual reversal of the free layer with applied field and the field‐independent fixed layer leads to a range of stable and reproducible remanent resistance values, as determined by the giant magnetoresistance of the device. An analysis of first‐order reversal curves combined with magnetic force microscopy shows that the origin of the effect is the field‐dependent population of up and down domains in the free layer.
An Esterase with Superior Activity and Enantioselectivity towards 1,2‐O‐Isopropylideneglycerol Esters Obtained by Protein Design
Authors: Godinho Luis F. , Reis Carlos R. , van Merkerk Ronald , Poelarends Gerrit J. , Quax Wim J.
Published: November 2012

The Escherichia coli esterase YbfF displays high activity towards 1,2‐O‐isopropylideneglycerol (IPG) butyrate and IPG caprylate, and prefers the R‐enantiomer of these substrates, producing the S‐enantiomer of the IPG product in excess. To improve the potential of the enzyme for the kinetic resolution of racemic esters of IPG, an enhancement of the activity and enantioselectivity would be highly desirable. Molecular docking of the R‐enantiomer of both IPG esters into the active site of YbfF allowed the identification of proximal YbfF active site residues. Four residues (25, 124, 185 and 235) were selected as targets for mutagenesis, in order to enhance YbfF activity and enantioselectivity towards IPG esters. Random mutagenesis at positions 25, 124, 185 and 235 yielded several best YbfF variants with enhanced activity and enantioselectivity towards IPG esters. The best YbfF mutant, W235I, exhibited a 2‐fold higher enantioselectivity than wild‐type YbfF, with an E=38 for IPG butyrate and an E=77 for IPG caprylate. Molecular docking experiments further support the enhanced enantioselectivity shown experimentally and the structural effects of this amino acid substitution on the active site of YbfF are provided. The engineered W235I mutant is an attractive catalyst for practical applications in the kinetic resolution of IPG esters.
Transition Metal‐Free α‐C(sp3)H Bond Functionalization of Amines by Oxidative Cross Dehydrogenative Coupling Reaction: Simple and Direct Access to C‐4‐Alkylated 3,4‐Dihydroquinazoline Derivatives
Authors: Kumar R. Arun , Saidulu G. , Prasad K. Rajendra , Kumar G. Sathish , Sridhar B. , Reddy K. Rajender
Published: November 2012

A transition metal‐free catalytic system has been developed for the cross dehydrogenative coupling of amines with nitroalkanes under mild condition employing potassium iodide/tert‐butyl hydrogen peroxide catalytic system. This methodology was further extended for the construction of biologically important N‐heterocycles, namely, 3,4‐dihydroquinazoline derivatives. This novel strategy provides a simple, efficient, and direct access to 4‐alkyl‐3,4‐dihydroquinazoline derivatives.
Economic plantwide control of the ethyl benzene process
Authors: Jagtap Rahul , Pathak Ashok S , Kaistha Nitin
Published: November 2012

Systematic plantwide control system design for economically optimal operation of the ethyl benzene process over a large throughput range is studied. As throughput is increased, constraints progressively become active with the highest number of active constraints at maximum throughput. An economic plantwide control system (CS1) is designed for operation at this most constrained operating point using a novel “top‐down” pairing approach with higher prioritization to the economic objectives over regulatory objectives. This structure is adapted for near optimal low throughput operation with constraints that go inactive taking up additional economic variable control. For comparison, a conventional plantwide control structure (CS2) with the throughput manipulator at a fresh feed and “bottom‐up” pairing for the control objectives is also synthesized. Four overrides are needed in CS2 to handle the hard equipment capacity constraints at maximum throughput. Rigorous dynamic simulations show that CS1 is dynamically and economically significantly superior to CS2. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1996–2014, 2013
TCF4 (e2‐2; ITF2): A schizophrenia‐associated gene with pleiotropic effects on human disease
Authors: Navarrete Katherinne , Pedroso Inti , De Jong Simone , Stefansson Hreinn , Steinberg Stacy , Stefansson Kari , Ophoff Roel A. , Schalkwyk Leonard C. , Collier David A.
Published: November 2012

Common SNPs in the transcription factor 4 (TCF4; ITF2, E2‐2, SEF‐2) gene, which encodes a basic Helix‐Loop‐Helix (bHLH) transcription factor, are associated with schizophrenia, conferring a small increase in risk. Other common SNPs in the gene are associated with the common eye disorder Fuch's corneal dystrophy, while rare, mostly de novo inactivating mutations cause Pitt‐Hopkins syndrome. In this review, we present a systematic bioinformatics and literature review of the genomics, biological function and interactome of TCF4 in the context of schizophrenia. The TCF4 gene is present in all vertebrates, and although protein length varies, there is high conservation of primary sequence, including the DNA binding domain. Humans have a unique leucine‐rich nuclear export signal. There are two main isoforms (A and B), as well as complex splicing generating many possible N‐terminal amino acid sequences. TCF4 is highly expressed in the brain, where plays a role in neurodevelopment, interacting with class II bHLH transcription factors Math1, HASH1, and neuroD2. The Ca2+ sensor protein calmodulin interacts with the DNA binding domain of TCF4, inhibiting transcriptional activation. It is also the target of microRNAs, including mir137, which is implicated in schizophrenia. The schizophrenia‐associated SNPs are in linkage disequilibrium with common variants within putative DNA regulatory elements, suggesting that regulation of expression may underlie association with schizophrenia. Combined gene co‐expression analyses and curated protein–protein interaction data provide a network involving TCF4 and other putative schizophrenia susceptibility genes. These findings suggest new opportunities for understanding the molecular basis of schizophrenia and other mental disorders. © 2012 Wiley Periodicals, Inc.
Beyond the “central sinus”: radiographic findings in patients undergoing revision functional endoscopic sinus surgery
Authors: Gore Mitchell R. , Ebert Charles S. , Zanation Adam M. , Senior Brent A.
Published: November 2012

Background

Functional endoscopic sinus surgery (FESS) is widely used by otolaryngologists to treat chronic rhinosinusitis (CRS). The sinonasal anatomy and pathology found in patients with CRS varies widely, as does the FESS technique practiced by otolaryngologists. Variations in the completeness of cell group dissection, combined with the technical challenge of angled endoscopy, result in a wide variation of the post‐FESS cavities harboring persistent disease. The purpose of this study was to identify previously incompletely dissected anatomic structures associated with mucosal thickening found in patients undergoing revision FESS for persistent or recurrent CRS.

Methods

Retrospective review of axial, coronal, and sagittal computed tomography (CT) scans of patients undergoing revision FESS by 3 fellowship‐trained rhinologists at a tertiary referral center.

Results

The CT scans of 55 patients undergoing revision FESS were reviewed. The most frequent radiographic findings were residual anterior and posterior ethmoid cells or septations, found in 65% of sides and 75% of patients. In addition, residual anterior ethmoid agger nasi cells, unopened sphenoid, and residual uncinates were found in 52%, 51%, and 46% of sides, respectively. A large percentage of the patients demonstrated residual ethmoid cells present on the lamina papyracea and skull base, with a lower number found posterior to the middle turbinate basal lamella. A greater number of residual right‐sided vs left‐sided ethmoid cells was noted, with the difference being significant (p < 0.05) at the skull base.

Conclusion

Analysis of CT scans of patients undergoing revision FESS for persistent or recurrent CRS frequently reveals persistent anatomical structures or incompletely resected cells associated with persistent mucosal thickening. Meticulous, complete cell group dissection combined with use of angled endoscopy along with identification of possible predisposing structures may aid in the reduction of need for revision surgery.
Dynamic rheological behavior and mechanical properties of PVC/CPE/MAP–POSS nanocomposites
Authors: Du Yonggang , Gao Jungang , Yang Jianbo , Liu Xiaoqian
Published: November 2012

Poly(vinyl chloride)/chlorinated polyethylene (PVC/CPE)/methylacryloylpropyl‐containing polyhedral oligomeric silsesquioxane (MAP–POSS) nanocomposites are prepared. The plastic behavior and dynamic rheological behavior of PVC/CPE/MAP–POSS are investigated. The influences of composition on dynamic storage modulus G′, loss modulus G″, and complex viscosity η* of PVC/CPE/MAP–POSS melts are discussed. The dynamic mechanical properties, mechanical properties, and morphology are determined. The results show that both plastic time and balance torque of the nanocomposites decrease, but the G′, G″, and η* all increase with increasing MAP–POSS content. The maximum value of the dynamic mechanical loss tan δ decreases and elasticity increases when MAP–POSS is added. The impact strength of the nanocomposites increases with increasing MAP–POSS content and has the best value at 10% content of MAP–POSS, which is 5.38 kJ/m2 higher than that of the blend without MAP–POSS. The MAP–POSS can be used as an efficient process aid and impact aid for the PVC/CPE blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and characterization of flavonoid laurate esters by transesterification
Authors: Bridson James H. , Grigsby Warren J. , Main Lyndsay
Published: November 2012

Laurate esters of catechin and condensed tannins were synthesized by both transesterification and conventional acylation techniques. Transesterification was developed as an alternative route to prepare flavonoid fatty acid esters as a prerequisite to advancing potential applications. Resorcinol, catechin, and two condensed tannins were transesterified with vinyl esters, and the resulting products were compared to those formed with lauroyl chloride. The esterified products, including catechin pentalaurate, were characterized both chemically and thermally. Transesterification produced partially substituted derivatives, with a preference for substitution at the catechol ring. Melt features were identified at or below 50°C, which were dependent upon the level of substitution. In addition, the tannin laurates showed thermal stability to at least 100°C and moderate retention of antioxidant properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of low viscosity, fast UV curing solder resist based on epoxy resin for ink‐jet printing
Authors: Yang Chao , Yang Zhen‐Guo
Published: November 2012

A novel photosensitive low viscosity epoxy resin was synthesized by polyethylene glycol (PEG)‐modified bisphenol‐A epoxy resin (E51). The resin was modified by ethylene glycol, diethylene glycol, and different molecule weights (200,300,400) PEGs to optimize the minimum viscosity. FTIR was used to determine molecule structure. Cationic photoinitiator (UVI‐6976) mixed with modified resin (10 wt %), was utilized to boost the resin curing under UV light. The curing degree was beyond 90% within 40 s and the whole process was monitored by photo‐DSC. The modified resin diluted with ethylene glycol diglycidyl ether, was screen printed onto polyimide and polyethylene terephthalate substrate, and the properties of solder mask were up to China printed circuit association standard. The solder resist also meet all requirements under ink‐jet printing technology as the viscosity is under 60 mPa·s and the curing duration is <1 min. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Insight into the Origin of the Positive Effects of Imidazolium Salt on Electrocatalytic Activity: Ionic Carbon Nanotubes as Metal‐Free Electrocatalysts for Oxygen Reduction Reaction
Authors: Kim Youn Soo , Shin Ju Yeon , Jeon Hyun Ji , Cha Areum , Lee Chongmok , Lee Sang‐gi
Published: November 2012

We report remarkable metal‐free electrocatalytic activities of the imidazolium salt‐functionalized ionic multi‐walled carbon nanotubes (IM‐f‐MWCNTs) in the oxygen reduction reaction (ORR). The electrocatalytic activity can be attributed to the induced polarization of the π‐electrons of CNTs, thus accelerating interfacial electron transfer. The zwitterionic MWCNTs functionalized with poly(vinylimidazolium sulfonate) have a more positive surface charge and exhibit a better electrocatalytic activity than the poly(vinylbutylimidazolium chloride)‐functionalized MWCNTs. The IM‐f‐MWCNTs showed better fuel selectivity than the commercial Pt/C electrocatalyst.
Chemical Synthesis and Enzymatic Testing of CMP‐Sialic Acid Derivatives
Authors: Wolf Saskia , Warnecke Svenja , Ehrit Jörg , Freiberger Friedrich , Gerardy‐Schahn Rita , Meier Chris
Published: November 2012

The cycloSal approach has been used in the past for the synthesis of a range of phosphorylated bioconjugates. In those reports, cycloSal nucleotides were allowed to react with different phosphate nucleophiles. With glycopyranosyl phosphates as nucleophiles, diphosphate‐linked sugar nucleotides were formed. Here, cycloSal‐nucleotides were used to prepare monophosphate‐linked sugar nucleotides successfully in high anomeric purity and high chemical yield. The method was successfully used for the synthesis of three nucleotide glycopyranoses as model compounds. The method was then applied to the syntheses of CMP‐N‐acetyl‐neuraminic acids (CMP‐Neu5NAc) and of four derivatives with different modifications at their amino functions (N‐propanoyl, N‐butanoyl, N‐pentanoyl and N‐cyclopropylcarbonyl). The compounds were used for initial enzymatic studies with a bacterial polysialyltransferase (polyST). Surprisingly, the enzyme showed marked differences in terms of utilisation of the four derivatives. The N‐propanoyl, N‐butanoyl, and N‐pentanoyl derivatives were efficiently used in a first transfer with a fluorescently labelled trisialo‐acceptor. However, elongation of the resulting tetrasialo‐acceptors worsened progressively with the size of the N‐acyl chain. The N‐pentanoyl derivative allowed a single transfer, leading to a capped tetramer. The N‐cyclopropylcarbonyl derivative was not transferred.