bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating flash flood discharge in an ungauged mountain catchment with 2D hydraulic models and dendrogeomorphic palaeostage indicators
Authors: Ballesteros Cánovas J. A. , Eguibar M. , Bodoque J. M. , Díez‐Herrero A. , Stoffel M. , Gutiérrez‐Pérez I.
Published: November 2010

There is still wide uncertainty about past flash‐flood processes in mountain regions owing to the lack of systematic databases on former events. This paper presents a methodology to reconstruct peak discharge of flash floods and illustrates a case in an ungauged catchment in the Spanish Central System. The use of dendrogeomorphic evidence (i.e. scars on trees) together with the combined use of a two‐dimensional (2D) numerical hydraulic model and a terrestrial laser scan (TLS) has allowed estimation of peak discharge of a recent flash flood. The size and height distribution of scars observed in the field have been used to define three hypothetical scenarios (Smin or minimum scenario; Smed or medium scenario; and Smax or maximum scenario), thus illustrating the uncertainty involved in peak‐discharge estimation of flash floods in ungauged torrents.

All scars analysed with dendrogeomorphic techniques stem from a large flash flood which took place on 17 December 1997. On the basis of the scenarios, peak discharge is estimated to 79 ± 14 m3 s−1. The average deviation obtained between flood stage and expected scar height was − 0·09 ± 0·53 m. From the data, it becomes obvious that the geomorphic position of trees is the main factor controlling deviation rate. In this sense, scars with minimum deviation were located on trees growing in exposed locations, especially on unruffled bedrock where the model predicts higher specific kinetic energy. The approach used in this study demonstrates the potential of tree‐ring analysis in palaeohydrology and for flood‐risk assessment in catchments with vulnerable goods and infrastructure. Copyright © 2010 John Wiley & Sons, Ltd.
Preliminary design of combined sewer overflows and stormwater tanks in Southern Italy
Authors: De Martino Giuseppe , De Paola Francesco , Fontana Nicola , Marini Gustavo , Ranucci Antonio
Published: November 2010

Pollution induced by runoff on receivers is an environmental problem deserving of much attention, especially over the past few years. The structural facilities most commonly used for first flush pollution impact reduction include sewer overflows and stormwater tanks. Nevertheless, their efficiency is a current research topic and the design criteria are not completely consolidated.

Based on extensive numerical simulations from 45 rain gauges located in Campania (southern Italy), two recent studies show that the performance of sewer overflows and offline stormwater tanks in reducing stormwater pollution can be reliably estimated without referring to rainfall data. Although rainfall dependency is generally negligible, it is more marked for some rainfall patterns.

On the basis of that observation, this paper proposes a simplified approach to estimate pollution reduction when sewer overflows or stormwater tanks are used, correlating their efficiency to the average rainfall per wet day, which is usually easy to calculate.

Analysis shows good agreement between values estimated according to the proposed approach and results provided by means of continuous simulations with a maximum deviation of about 0.05. Copyright © 2010 John Wiley & Sons, Ltd.
Repair of calvarial defects in rats by prefabricated, degradable, long fibre composite implants
Authors: Scotchford C. A. , Shataheri M. , Chen P.‐S. , Evans M. , Parsons A. J. , Aitchison G. A. , Efeoglu C. , Burke J. L. , Vikram A. , Fisher S. E. , Rudd C. D.
Published: November 2010

We report results from an initial small animal study designed to provide information on the biocompatibility of a novel biodegradable composite designed for craniomaxillofacial reconstruction. Rat calvarium was chosen as a clinically analogous model, which allowed comparison between experimental groups (PCL alone, PCL/phosphate glass, or PCL/bioglass implants) and control groups (empty defects or bone grafted defects). All animals recovered well from surgery and no clinical complications were observed. Histological assessment indicated a lack of inflammatory response. The amount of new bone formation at the dural aspect of the implant was statistically significantly higher in the PCL/phosphate glass group than the other experimental groups. This study confirms, in a clinically analogous model, the promise of the novel PCL/phosphate glass composite material. Work is planned toward manufacturing scale up and clinical trials. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2010.
Extracellular matrix‐mimetic adhesive biomaterials for bone repair
Authors: Shekaran Asha , García Andrés J.
Published: November 2010

Limited osseointegration of current orthopedic biomaterials contributes to the failure of implants such as arthroplasties, bone screws, and bone grafts, which present a large socioeconomic cost within the United States. These implant failures underscore the need for biomimetic approaches that modulate host cell–implant material responses to enhance implant osseointegration and bone formation. Bioinspired strategies have included functionalizing implants with extracellular matrix (ECM) proteins or ECM‐derived peptides or protein fragments, which engage integrins and direct osteoblast adhesion and differentiation. This review discusses (1) bone ECM composition and key integrins implicated in osteogenic differentiation, (2) the use of implants functionalized with ECM–mimetic peptides/protein fragments, and (3) growth factor–derived peptides to promote the mechanical fixation of implants to bone and to enhance bone healing within large defects. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2010.
Furanodienone inhibits cell proliferation and survival by suppressing ERα signaling in human breast cancer MCF‐7 cells
Authors: Li Ying‐Wei , Zhu Guo‐Yuan , Shen Xiao‐Ling , Chu Jian‐Hong , Yu Zhi‐Ling , Fong Wang‐Fun
Published: November 2010

Estrogen receptor alpha (ERα) plays an important role in the development and progression of breast cancer and thus the attenuation of ERα activities is a promising treatment strategy. Furanodienone is one of the main bioactive chemical components of Rhizoma Curcumae which is commonly used in Chinese medicine for the treatment of cancer. In this study, we investigated the effects of furanodienone on human breast cancer MCF‐7, T47D, and MDA‐MB‐231 cells. Our results showed that furanodienone could inhibit MCF‐7, T47D, and MDA‐MB‐231 cells proliferation in a dose (10–160 µM) dependent manner. ERα‐negative MDA‐MB‐231 cells were less sensitive to furanodienone than ERα‐positive MCF‐7 and T47D cells. Furanodienone could effectively block 17β‐estradiol (E2)‐stimulated MCF‐7 cell proliferation and cell cycle progression and induce apoptosis evidenced by the flow cytometric detection of sub‐G1 DNA content and the appearance of apoptotic nuclei after DAPI staining. Furanodienone specifically down‐regulated ERα protein and mRNA expression levels without altering ERβ expression. Furanodienone treatment inhibited E2‐stimulation of estrogen response element (ERE)‐driven reporter plasmid activity and ablated E2‐targeted gene (e.g., c‐Myc, Bcl‐2, and cyclin D1) expression which resulted in the inhibition of cell cycle progression and cell proliferation, and in the induction of apoptosis. Knockdown of ERα in MCF‐7 cells by ERα‐specific siRNA decreased the cell growth inhibitory effect of furanodienone. These findings suggest that effects of furanodienone on MCF‐7 cells are mediated, at least in part, by inhibiting ERα signaling. J. Cell. Biochem. 112: 217–224, 2011. © 2010 Wiley‐Liss, Inc.
A reoptimized GROMOS force field for hexopyranose‐based carbohydrates accounting for the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers
Authors: Hansen Halvor S. , Hünenberger Philippe H.
Published: November 2010

This article presents a reoptimization of the GROMOS 53A6 force field for hexopyranose‐based carbohydrates (nearly equivalent to 45A4 for pure carbohydrate systems) into a new version 56ACARBO (nearly equivalent to 53A6 for non‐carbohydrate systems). This reoptimization was found necessary to repair a number of shortcomings of the 53A6 (45A4) parameter set and to extend the scope of the force field to properties that had not been included previously into the parameterization procedure. The new 56ACARBO force field is characterized by: (i) the formulation of systematic build‐up rules for the automatic generation of force‐field topologies over a large class of compounds including (but not restricted to) unfunctionalized polyhexopyranoses with arbritrary connectivities; (ii) the systematic use of enhanced sampling methods for inclusion of experimental thermodynamic data concerning slow or unphysical processes into the parameterization procedure; and (iii) an extensive validation against available experimental data in solution and, to a limited extent, theoretical (quantum‐mechanical) data in the gas phase. At present, the 56ACARBO force field is restricted to compounds of the elements C, O, and H presenting single bonds only, no oxygen functions other than alcohol, ether, hemiacetal, or acetal, and no cyclic segments other than six‐membered rings (separated by at least one intermediate atom). After calibration, this force field is shown to reproduce well the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers. As a result, the 56ACARBO force field should be suitable for: (i) the characterization of the dynamics of pyranose ring conformational transitions (in simulations on the microsecond timescale); (ii) the investigation of systems where alternative ring conformations become significantly populated; (iii) the investigation of anomerization or epimerization in terms of free‐energy differences; and (iv) the design of simulation approaches accelerating the anomerization process along an unphysical pathway. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
TRPM8 in mouse sperm detects temperature changes and may influence the acrosome reaction
Authors: Martínez‐López Pablo , Treviño Claudia L. , de la Vega‐Beltrán José Luis , De Blas Gerardo , Monroy Esteban , Beltrán Carmen , Orta Gerardo , Gibbs Gerard M. , O'Bryan Moira K. , Darszon Alberto
Published: November 2010

Changes in the concentration of intracellular Ca2+ ([Ca2+]i) trigger and/or regulate principal sperm functions during fertilization, such as motility, capacitation, and the acrosome reaction (AR). Members of the large TRP channel family participate in a variety of Ca2+‐dependent cell signaling processes. The eight TRPM channel members constitute one of the seven groups belonging to this family. Here we document using RT‐PCR experiments the presence of Trpm2, 4, 7, and 8 in mouse spermatogenic cells. Trpm8 transcription is up‐regulated after day 30. The localization of TRPM8 protein in mouse sperm was confirmed by immunocytochemistry and Western blots. Patch clamp recordings in testicular mouse sperm revealed TRPM8 agonist (menthol and icilin) activated currents sensitive to TRPM8 inhibitors N‐(4‐t‐Butylphenyl)‐4‐(3‐Chloropyridin‐2‐yl)tetrahydropyrazine‐1(2H)‐carboxamide (BCTC) and capsazepine. These findings are consistent with the presence of functional TRPM8 in mouse sperm. Furthermore, menthol induced a [Ca2+]i increase and the AR in these cells, that were inhibited by capsazepine (20 µM) and BCTC (1.6 µM). Notably, the progesterone and zona pellucida‐induced AR was significantly (>40%) inhibited by BCTC and capsazepine, suggesting the possible participation of TRPM8 channels in this reaction. TRPM family members present in sperm could be involved in other important signaling events, such as thermotaxis, chemotaxis, and mechanosensory transduction. J. Cell. Physiol. 226: 1620–1631, 2011. © 2010 Wiley‐Liss, Inc.
The number of CAG repeats within the normal allele does not influence the age of onset in Huntington's disease
Authors: Klempíř Jiří , Židovská Jana , Štochl Jan , Ing Věra Kebrdlová , Uhrová Tereza , Roth Jan
Published: November 2010

Huntington's disease (HD) is caused by the expansion of the number of CAG repeats on the chromosome 4p16.3, which results in elongated glutamine tract of huntingtin. The purpose of this work was to examine the interaction between the normal and mutant alleles of this gene and their effect on the clinical onset of HD. We hypothesized that in patients with identical number of CAG repeats within the mutant allele, the age of onset of HD is influenced by the number of CAG repeats within the normal allele. We analyzed the relations between the number of CAG repeats within the normal and mutant alleles, the age at HD onset, and the character of initial symptoms in 468 patients with clinically expressed HD. Although the Cox regression coefficient of 0.15 was significant (P < 0.0001), the regression model explained only 28% of the variance of the age at onset related to the effect of the number of CAG repeats within normal allele. Within the groups of patients with the same number of CAG repeats of the mutant allele, number of CAG repeats of the normal allele was found uncorrelated to the age at onset. Furthermore, when analyzing subgroups of patients with the same allelic composition on both alleles, we failed to observe any correlation with the age at the onset. Our analysis gives no corroboration to the idea of a normal allele having a share in the modification of the age at HD onset. We believe that with the current state of knowledge it is not possible to devise a mathematical model for HD onset prediction because too many entirely unknown modifying factors are still involved. © 2010 Movement Disorder Society
Infinite elements in a poroelastodynamic FEM
Authors: Nenning M. , Schanz M.
Published: November 2010

An infinite element is presented to treat wave propagation problems in unbounded saturated porous media. The porous media is modeled by Biot's theory. Conventional finite elements are used to model the near field, whereas infinite elements are used to represent the behavior of the far field. They are constructed in such a way that the Sommerfeld radiation condition is fulfilled, i.e. the waves decay with distance and are not reflected at infinity. To provide the wave information the infinite elements are formulated in Laplace domain. The time domain solution is obtained by using the convolution quadrature method as the inverse Laplace transformation. The temporal behavior of the near field is calculated using standard time integration schemes, e.g. the Newmark method. Finally, the near and far field are combined using a substructure technique for any time step. The accuracy as well as the necessity of the proposed infinite elements, when unbounded domains are considered, is demonstrated by different examples. Copyright © 2010 John Wiley & Sons, Ltd.
An elasto‐viscoplastic model for diatomaceous mudstone and numerical simulation of compaction bands
Authors: Oka F. , Kimoto S. , Higo Y. , Ohta H. , Sanagawa T. , Kodaka T.
Published: November 2010

It is well known that highly porous rocks under relatively high confining pressure succumb to volumetric compression with the emergence of the so‐called compaction bands. These normally occur as perpendicular or very slightly inclined deformation bands with respect to the direction of the most compressive principal stress. An experimental study of diatomaceous mudstone, a highly structured and porous soft rock, was conducted to demonstrate the existence of compaction bands in laboratory tests. In these tests, the local strain field on the specimen's face is determined by means of image analysis. The main objective of this paper is the numerical simulation of compaction bands in diatomaceous mudstone. First, an elasto‐viscoplastic model considering microstructural degradation is used to simulate the behavior of diatomaceous mudstone at the element test level. It has been found that such a model can accurately reproduce the stress–strain and dilatancy responses of diatomaceous mudstone. Then, a numerical analysis of a series of triaxial compression tests under drained conditions was carried out using the elasto‐viscoplastic model within the framework of Biot's theory for a two‐phase mixture. As a boundary problem, the triaxial tests were analyzed via finite elements with an updated Lagrangian formulation to simulate strain localization behavior under large deformations. The present study demonstrates that it is indeed possible to successfully simulate the experimentally observed compaction bands in diatomaceous mudstone. Copyright © 2010 John Wiley & Sons, Ltd.
The dual role of HLXB9 in leukemia
Authors: Ferguson Stuart , Gautrey Hannah E. , Strathdee Gordon
Published: November 2010

Background

The HLXB9 gene encodes a homeodomain containing transcription factor which has been implicated in the development of both solid and hematological malignancies. In leukemia it is one of the two fused genes, along with ETV6, in a recurrent translocation frequently observed in infant AML.

Procedure

Here we investigate the role of epigenetic inactivation of the HLXB9 gene in leukemia. Quantitative DNA methylation analysis was performed using the COBRA assay, and qRT‐PCR was used to assess the effects of methylation on expression in hematological cell lines and primary ALL samples.

Results

Hypermethylation of the HLXB9 gene was found to be a frequent event in childhood ALL, occurring in 33% of cases. However, it was rarely or never observed in other types of leukemia, including AML, CML, and CLL, with the exception of adult ALL, in which 39% of cases were hypermethylated. Furthermore, hypermethylation of HLXB9 results in loss of expression in hematological cell lines and primary ALL samples.

Conclusion

These results suggest that HLXB9 may have a dual role in childhood leukemia, as an oncogene in infant AML but as a tumor suppressor in childhood ALL. Pediatr Blood Cancer 2011;56:349–352. © 2010 Wiley‐Liss, Inc.
Room temperature degenerate four‐wave mixing in CuCl thin films
Authors: Ichimiya Masayoshi , Mochizuki Keita , Ashida Masaaki , Yasuda Hideki , Ishihara Hajime , Itoh Tadashi
Published: November 2010

We report observation of anomalous temperature dependences of degenerate four‐wave mixing (DFWM) spectra in CuCl thin films with high crystalline quality and thicknesses in the order of 10–100 nm. The behavior of temperature dependence can be explained by the change in the relative intensities among component spectra. The excitonic state with large radiative width can be observed at high temperatures due to the superradiance faster than the nonradiative decay process. We succeeded in observing the DFWM signal up to room temperature based on the extremely large radiative width peculiar to the size region beyond the long‐wavelength approximation regime.
Simulator‐supported descriptions of complex dynamic problems: experimental results on task performance and system understanding
Authors: Kopainsky Birgit , Sawicka Agata
Published: November 2010

Research shows that people have great difficulty in understanding dynamics. Even when problem descriptions contain all the necessary information, people tend to mismanage dynamic systems. Given the increasing complexity of our modern societies, effective ways to communicate dynamics need to be identified. In this paper we explore the effectiveness of simulator‐supported problem descriptions. We add an interactive simulation tool to the textual instructions of a well‐tested natural‐resource management task. With this tool, the dynamic aspects of the problem can be explored. In laboratory experiments, we find that simulator‐supported problem presentations improve both the subjects' performance and their understanding. The analysis of mental effort data reveals that the simulator facilitates effective cognitive processing and thus allows the subjects to acquire more adequate mental representations of the task. Building on these results, we derive implications for the design of interactive learning environments and for the more general presentation of complex dynamic problems. Copyright © 2010 System Dynamics Society.
U.S. Healthcare Reform, 2009–2010: Implications for African Americans
Authors: Leigh Wilhelmina A. , Wheatley Anna L.
Published: November 2010

This paper describes issues that need to be addressed to reform the U.S. healthcare delivery system, the solutions to some of these issues that are part of the Patient Protection and Affordable Care Act (as amended), and the implications for African Americans of some of the recently enacted reforms. These reforms take the first steps toward eliminating the insurance coverage gap that keeps many from receiving needed care. The necessary and simultaneous emphasis on cost containment of this legislation, however, may limit access to health care for African Americans.
N‐methyl‐d‐aspartate receptor‐mediated modulations of the anti‐allodynic effects of 5‐HT1B/1Dreceptor stimulation in a rat model of trigeminal neuropathic pain
Authors: Kayserl Valérie , Latrémolièrel Alban , Hamonl Michel , Bourgoinl Sylvie
Published: November 2010

Previous studies showed that triptans and other 5‐HT1B/1D‐receptor agonists attenuate hyper‐responsiveness to mechanical stimulation of the face in a rat model of trigeminal neuropathic pain, probably by activating 5‐HT1B/1D‐receptors on primary afferent nociceptive fibers. We now tested whether blockade of post‐synaptic receptors for the excitatory amino acid glutamate released by these fibers would increase this action. We thus evaluated whether (±)1‐hydroxy‐3‐aminopyrrolidine‐2‐one (HA‐966), an antagonist at the glycine/d‐serine site of N‐methyl‐d‐aspartate (NMDA)‐receptors, would potentiate the anti‐allodynic action of dihydroergotamine and zolmitriptan in rats with chronic constriction injury to the infraorbital nerve (CCI‐ION). Complementary studies were performed with other NMDA‐receptor ligands and in rats with chronic constriction injury to the sciatic nerve (CCI‐SN) for comparison.

Injury was produced by loose ligatures of the nerves. Responsiveness to mechanical stimulation (vibrissae or hindpaw territories) with von Frey filaments was used to evaluate allodynia 2 weeks after nerve ligature. Rats received NMDA‐receptor ligands or saline 20 min before dihydroergotamine (25–100μg/kg, i.v.) or zolmitriptan (25–100μg/kg, s.c.).

HA‐966 (2.5 mg/kg, s.c.), inactive on its own, enhanced the anti‐allodynic effects of dihydroergotamine (eightfold increase) and zolmitriptan (threefold increase) in CCI‐ION rats, but these drugs exerted no effects in allodynic CCI‐SN rats. NMDA‐receptor blockade by memantine (5 mg/kg, i.p.) also enhanced, whereas activation at glycine/NMDA site byd‐cycloserine (3 mg/kg, i.p.) reduced the anti‐allodynic properties of zolmitriptan in CCI‐ION rats. Combined administration of NMDA‐receptor antagonist and 5‐HT1B/1D‐receptor agonist may be a promising approach for alleviating trigeminal neuropathic pain.
Review Article: ‘Major Combat Operations Have Ended’? Arguing about Rational Choice
Authors: Hindmoor Andrew
Published: November 2010

Arguing about rational choice theory remains a popular pastime. Following the publication of Green and Shapiro’sPathologies of Rational Choice Theory,a backlash against the use of rational choice theory within political science gained momentum. This article shows how, since 1994, sceptics have refined and extended the critique of rational choice and how practitioners have defended their approach, and a more general argument has emerged. In the 1990s, attitudes towards rational choice theory constituted a fundamental fault-line within the discipline, but changes to the way in which rational choice is practised and defended, together with some broader changes in the social sciences, have created more areas of common ground and taken some of the urgency out of this debate.
Religious Resurgence in Contemporary Asia: Southeast Asian Perspectives on Capitalism, the State, and the New Piety
Authors: Hefner Robert W.
Published: November 2010

Large portions of East and Southeast Asia are in the throes of a historically unprecedented upsurge in religious observance and association. Many of the new varieties of religiosity are more popular, voluntary, and laity based than the religions of yesteryear. Many are also marked by the heightened participation of women, and an emphasis on inner-worldly well-being as well as otherworldly transcendence. Focusing on Southeast Asia, but with references to developments in China, this article examines the social and moral genealogy of eastern Asia's religious vitalization. Many analysts have emphasized the influence of postcolonial secularisms, neoliberal disciplines, and ascendant civil societies in the religious resurgence. Although these factors have indeed played a role, the macro-narratives of the state, capital, and democratization often give insufficient attention to the micro- and meso-passions of self, family, and neighborhood, all of which have contributed to the popularization and proximatization of once restricted spiritual disciplines.
Mole Architects: thinking and making
Authors: Walker Stephen
Published: November 2010

Mole Architects was set up by Meredith Bowles in 1997, and has become known for well-crafted, contextually responsive and ecologically sensitive projects. One of the claims that Mole make in their practice brochure is that their work is identified by a consistency of attitude rather than a ‘house style’. This claim emphasises thinking, analysis and process but this is balanced by the evidence presented in their realised work, which demonstrates an undeniable interest and delight in the materiality and making of buildings. Reflecting on the enduring influence of his architectural education, Bowles acknowledges this balance: ‘What I think these formative experiences refer to is a belief in the importance of things rather than ideas, or rather that ideas reside in the thing itself’.
Island identities: the Pier Arts Centre, Orkney
Authors: Hanks Laura Hourston
Published: November 2010

In the context of the maturation of traditional concepts of identity into ‘new forms of plurality and spatiality’, this paper aims to explore the role of genius loci, memory, and ultimately identity in a particular gallery: the Pier Arts Centre in Stromness, Orkney.

Initially, it considers ways in which regional and vernacular identities have informed and enriched the architectural project, instilling it with tangible and intangible traces of place, and the past and present people of that place. Formal and material influences from the abstract but poetic idea of north, the local topography and town, and the existent buildings on site, are revealed.
Not a locked box: the everyday art of the Aalto atelier
Authors: Charrington Harry
Published: November 2010

The schism between our admiration of the artefacts of the great architectural practices of the twentieth century, and our lack of knowledge as to how those achievements were manifest, is one of the most enduring characteristics of modern architecture. Modern architectural practice and its sustaining historiography has typically focused on the image of the designed object at the expense of the skills and conditions that shaped it; a focus on reputation rather than comprehension. Indeed those constituting contingencies of design are more often seen as obstructing the architectural vision and true reality of experience; hence the fixation on a singular (and possibly post-rationalised) first ‘spark’ of conception and the photogenic qualities of the realised, and usually uninhabited, object. Dalibor Veseley is right to state that ‘instrumentality (techne) must always be subordinated to symbolic representation (poiesis), because techne refers only to a small segment of reality, while poiesis refers to reality as a whole'. Nevertheless, in the current climate the statement is likely to be understood as further legitimising the continuing neglect of what architects actually do.
Architecture at A-level
Authors: Atkinson Robert
Published: November 2010

This paper describes an A-level course (a two-year course for 16–19 year old students) which concentrates entirely on architecture using an art studies syllabus as its basis. The course has run since 2001, during which time it has grown considerably in popularity. The first year concentrates on the history of architecture and on how different histories are perceived from different viewpoints using a comparative analysis of several buildings. In the second year the emphasis is on how architecture emerges from and affects social interaction, through a close study of a single building. The paper goes on to discuss the value of the course and qualification, especially in relation to further architectural study at university.
Nonlinear estimation of El Niño impact on the North Atlantic winter
Authors: OrtizBeviá M. J. , Pérez‐González I. , Alvarez‐García F. J. , Gershunov A.
Published: November 2010

The differences in the teleconnections forced by different El Niño events (Niños) can be partly explained by the intrinsic nonlinearity of the atmospheric response. In the present study, we segregate the responses of the North Atlantic to strong from those to moderate Niños and compare nonlinear and linear estimates. El Niño forcing is represented by the tropical Pacific sea surface temperature anomalies, and the North Atlantic atmospheric response is represented by sea level pressure anomalies in the region. To gain insight into the evolution of El Niño teleconnections in a future climate, linear and nonlinear analyses are carried out on the corresponding data fields in the control and scenario simulations of a climate model experiment. This experiment presents, in its control version, realistic teleconnections. In the observational analysis, the nonlinear method performs only slightly better than the linear one. However, in the analysis of the interannual variability by a long control experiment of a realistic climate simulation, the nonlinear estimate improves significantly with respect to the linear one. The analysis of the corresponding scenario experiment points to an intensification of the (negative) surface pressure anomalies associated with the Niños in the west European sector in a future climate. This feature is related to the important stratospheric anomalies in the same region, revealed by previous studies.
Radial anisotropy in the crust of SE Tibet and SW China from ambient noise interferometry
Authors: Huang Hui , Yao Huajian , van der Hilst Robert D.
Published: November 2010

We use Rayleigh and Love wave Green's functions estimated from ambient seismic noise to study crustal structure and radial anisotropy in the tectonically complex and seismically active region west of the Sichuan Basin and around the Eastern Himalaya Syntaxis. In agreement with previous studies, low velocity zones are ubiquitous in the mid‐lower crust, with substantial variations both laterally and vertically. Discrepancies between 3‐D shear velocity from either Rayleigh (VSV) or Love (VSH) waves are examined both in view of non‐uniqueness of tomographic solutions and radial anisotropy. Low shear wave speed and radial anisotropy with VSH > VSV are most prominent in mid‐lower crust in area northwest to the Lijiang‐Muli fault and around the Red River and Xiaojiang faults. This anisotropy could be caused by sub‐horizontal mica fabric and its association with low velocity zones suggests mica alignment due to flow in deep crustal zones of relatively low mechanical strength.
Vegetation colonization of permafrost‐related landslides, Ellesmere Island, Canadian High Arctic
Authors: Cannone Nicoletta , Lewkowicz Antoni G. , Guglielmin Mauro
Published: November 2010

Relationships between vegetation colonization and landslide disturbance are analyzed for 12 active‐layer detachments of differing ages located in three areas of the Fosheim Peninsula, Ellesmere Island (80°N). We discuss vegetation as an age index for landslides and a way to assess the time needed for complete recolonization of the surfaces since landslide detachment. Vegetation on undisturbed terrain is similar in the three areas but is more highly developed and complex inland due to a warmer summer climate. On a regional scale, the location of the area is as important as the effect of landslide age on vegetation colonization because of the influence of mesoclimatic conditions on vegetation development. On a landscape scale, there is a positive relationship between landslide age and vegetation development, as represented by total vegetation cover, floristic composition, and successional stage. Consequently, vegetation can be used at this scale as an indicator of landslide age. Fifty years are required to restore vegetation patches to a floristic composition similar to communities occurring in undisturbed conditions, but with lower floristic richness and a discontinuous cover and without well‐developed layering. The shorter time needed for landslide recovery in the area with the warmest summer climate confirms the sensitivity of arctic vegetation to small differences in air temperature. This could trigger a set of interlinked feedbacks that would amplify future rates of climate warming.
Polycentric networks and resilience in urban systems: A comparison of Baltimore and Seattle
Authors: Romolini Michele , Grove Morgan
Published: November 2010

Numerous studies have demonstrated that successful resource management requires collaboration among many groups. While most research has been conducted on rural resource management, collaborative management is now recognized as an important strategy in densely settled urban areas. Cities generally consist of many fragmented land parcels under different types of use and ownership, which produces a large and diverse group of stakeholders with an interest in resource management decisions. Past research has shown that 1) natural resource stewardship organizations play an important role in both managing natural resources and building social capital; 2) successful outcomes often rely on effective collaborations through organizational networks; 3) there are different types of network structures; and 4) the effectiveness of a network can depend on its structure. However, missing from the field is empirical research analyzing how natural resource stewardship networks impact social and ecological outcomes, both spatially and temporally.Building on pioneering work on urban environmental groups in New York City and developing efforts in Chicago, this research will assess the stewardship networks in Seattle and Baltimore. More specifically, it will examine whether the network structure affects social and ecological outcomes; and conversely, whether variation in social and ecological conditions affects the resulting social network. Through a mixed methodological approach employing interviews, organizational surveys, spatial mapping, and social network analysis, this research examines:• What network relationships exist between environmental stewardship groups in Baltimore? In Seattle?• What is the spatial structure of these stewardship networks?• Does network structure affect social and ecological outcomes?• Does variation in social and ecological conditions predict the resulting network?• How do the stewardship networks in Baltimore and Seattle compare?Results from this study will contribute to the growing body of research on polycentric governance networks. The need for longitudinal and comparative studies in this area is evident, as many cities are looking to adaptive management strategies to respond to the needs of an rapidly changing population and landscape. In Baltimore, this data can be compared to organizational network data collected 10 years ago. In Seattle, the study will establish baseline network data, which provides a foundation for future studies. Similarities and differences between cities may provide implications for whether environmental stewardship programs and other sustainability initiatives can be applied from one city to another.
Comparative study on the gas to solution phase solvation free energies of model combustion flue gas compounds (N~2~, O~2~, CO~2~, H~2~O, SO~2~, and CO) in 178 organic solvents using the IEFPCM-UFF, CPCM, and SMD implicit solvent models at the Gaussian-4 (G4) level of theory
Authors: Rayne Sierra , Forest Kaya
Published: November 2010

Gas to solution phase Gibbs free energies of solvation at 298.15 K for transfer of six representative combustion flue gas compounds (N~2~, O~2~, CO~2~, H~2~O, SO~2~, and CO) were calculated at the Gaussian-4 (G4) level of theory using the IEFPCM-UFF, CPCM, and SMD implicit solvent models for 178 organic solvents. The IEFPCM-UFF and CPCM models yield similar free energies of solvation for all six compounds in each of the solvents considered, having maximum absolute intra-solvent deviations <1.6 kJ mol^-1^. Substantial free energy of solvation differences were observed between the IEFPCM-UFF/CPCM and SMD models, with maximum absolute intra-solvent deviations up to 45.5 kJ mol^-1^. The IEFPCM-UFF and CPCM models displayed strong free energy of solvation correlations with the solvent dielectric constant for each compound, whereas the SMD model exhibits a significantly more variable free energy of solvation relationship with the solvent dielectric constant.
The influence of pipe length on turbulence statistics computed from direct numerical simulation data
Authors: Chin C. , Ooi A. S. H. , Marusic I. , Blackburn H. M.
Published: November 2010

In this paper, direct numerical simulation of fully developed turbulent pipe flow is carried out at Reτ≈170 and 500 to investigate the effect of the streamwise periodic length on the convergence of turbulence statistics. Mean flow, turbulence intensities, correlations, and energy spectra were computed. The findings show that in the near-wall region (below the buffer region, r+≤30), the required pipe length for all turbulence statistics to converge needs to be at least a viscous length of O(6300) wall units and should not be scaled with the pipe radius (δ). It was also found for convergence of turbulence statistics at the outer region that the pipe length has to be scaled with pipe radius and a proposed pipe length of 8πδ seems sufficient for the Reynolds numbers considered in this study.
Singlet and triplet potential surfaces for the O2+C2H4 reaction
Authors: Park Kyoyeon , West Aaron , Raheja Erica , Sellner Bernhard , Lischka Hans , Windus Theresa L. , Hase William L.
Published: November 2010

Electronic structure calculations at the CASSCF and UB3LYP levels of theory with the aug-cc-pVDZ basis set were used to characterize structures, vibrational frequencies, and energies for stationary points on the ground state triplet and singlet O2+C2H4 potential energy surfaces (PESs). Spin-orbit couplings between the PESs were calculated using state averaged CASSCF wave functions. More accurate energies were obtained for the CASSCF structures with the MRMP2/aug-cc-pVDZ method. An important and necessary aspect of the calculations was the need to use different CASSCF active spaces for the different reaction paths on the investigated PESs. The CASSCF calculations focused on O2+C2H4 addition to form the C2H4O2 biradical on the triplet and singlet surfaces, and isomerization reaction paths ensuing from this biradical. The triplet and singlet C2H4O2 biradicals are very similar in structure, primarily differing in their C-C-O-O dihedral angles. The MRMP2 values for the O2+C2H4→C2H4O2 barrier to form the biradical are 33.8 and 6.1 kcal/mol, respectively, for the triplet and singlet surfaces. On the singlet surface, C2H4O2 isomerizes to dioxetane and ethane-peroxide with MRMP2 barriers of 7.8 and 21.3 kcal/mol. A more exhaustive search of reaction paths was made for the singlet surface using the UB3LYP/aug-cc-pVDZ theory. The triplet and singlet surfaces cross between the structures for the O2+C2H4 addition transition states and the biradical intermediates. Trapping in the triplet biradical intermediate, following O32+C2H4 addition, is expected to enhance triplet→singlet intersystem crossing.
On the role of frustration in excitable systems
Authors: Kaluza Pablo , Meyer-Ortmanns Hildegard
Published: November 2010

We study the role of frustration in excitable systems that allow for oscillations either by construction or in an induced way. We first generalize the notion of frustration to systems whose dynamical equations do not derive from a Hamiltonian. Their couplings can be directed or undirected; they should come in pairs of opposing effects like attractive and repulsive, or activating and repressive, ferromagnetic and antiferromagnetic. As examples we then consider bistable frustrated units as elementary building blocks of our motifs of coupled units. Frustration can be implemented in these systems in various ways: on the level of a single unit via the coupling of a self-loop of positive feedback to a negative feedback loop, on the level of coupled units via the topology or via the type of coupling which may be repressive or activating. In comparison to systems without frustration, we analyze the impact of frustration on the type and number of attractors and observe a considerable enrichment of phase space, ranging from stable fixed-point behavior over different patterns of coexisting options for phase-locked motion to chaotic behavior. In particular we find multistable behavior even for the smallest motifs as long as they are frustrated. Therefore we confirm an enrichment of phase space here for excitable systems with their many applications in biological systems, a phenomenon that is familiar from frustrated spin systems and less known from frustrated phase oscillators. So the enrichment of phase space seems to be a generic effect of frustration in dynamical systems. For a certain range of parameters our systems may be realized in cell tissues. Our results point therefore on a possible generic origin for dynamical behavior that is flexible and functionally stable at the same time, since frustrated systems provide alternative paths for the same set of parameters and at the same “energy costs.”
Transient infrared spectra of CH3SOO and CH3SO observed with a step-scan Fourier-transform spectrometer
Authors: Chu Li-Kang , Lee Yuan-Pern
Published: November 2010

A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to monitor time-resolved infrared absorption of transient species produced upon irradiation at 248 nm of a flowing mixture of CH3SSCH3 and O2 at 260 K. Two transient bands observed with origins at 1397±1 and 1110±3 cm−1 are tentatively assigned to the antisymmetric CH3-deformation and OO stretching modes of syn-CH3SOO, respectively; the observed band contour indicates that the less stable anti-CH3SOO conformer likely contributes to these absorption bands. A band with an origin at 1071±1 cm−1, observed at a slightly later period, is assigned to the SO stretching mode of CH3SO, likely produced via secondary reactions of CH3SOO. These bands fit satisfactorily with vibrational wavenumbers and rotational contours simulated based on rotational parameters of syn-CH3SOO, anti-CH3SOO, and CH3SO predicted with density-functional theories B3LYP/aug-cc-pVTZ and B3P86/aug-cc-pVTZ. Two additional bands near 1170 and 1120 cm−1 observed at a later period are tentatively assigned to CH3S(O)OSCH3 and CH3S(O)S(O)CH3, respectively; both species are likely produced from self-reaction of CH3SOO. The production of SO2 via secondary reactions was also observed and possible reaction mechanism is discussed.
Correlation reflectometry at TEXTOR
Authors: Krämer-Flecken A. , Soldatov S. , Vowinkel B. , Müller P.
Published: November 2010

In high temperature fusion plasmas the transport of energy and particles is commonly believed to be driven by turbulence. Turbulence quantities as correlation length and decorrelation time are important for the confinement properties of a plasma. Besides other diagnostics, correlation reflectometry has proven to be a suitable tool for the measurement of turbulence properties. At the medium sized Toroidal EXperiment for Technical Oriented Research (TEXTOR) the existing correlation reflectometry has been recently upgraded. A new reflectometer based on a microwave synthesizer has been developed and installed for the investigation of turbulence properties in a fusion plasma. Together with the existing reflectometer the measurement of radial correlation length and decorrelation time becomes available. Both reflectometers are computer controlled and allow to program individual frequency sequences and the duration of each frequency step. With the existing poloidal antenna array at θ=0° and on top of the vacuum vessel, the system allows the measurement of radial correlation and poloidal correlations at the same time. First experiments have been performed and the results on the radial correlation length of density fluctuations in a fusion plasma are presented.
Optical boundary reconstruction of tokamak plasmas for feedback control of plasma position and shape
Authors: Hommen G. , de Baar M. , Nuij P. , McArdle G. , Akers R. , Steinbuch M.
Published: November 2010

A new diagnostic is developed to reconstruct the plasma boundary using visible wavelength images. Exploiting the plasma’s edge localized and toroidally symmetric emission profile, a new coordinate transform is presented to reconstruct the plasma boundary from a poloidal view image. The plasma boundary reconstruction is implemented in MATLAB and applied to camera images of Mega-Ampere Spherical Tokamak discharges. The optically reconstructed plasma boundaries are compared to magnetic reconstructions from the offline reconstruction code EFIT, showing very good qualitative and quantitative agreement. Average errors are within 2 cm and correlation is high. In the current software implementation, plasma boundary reconstruction from a single image takes 3 ms. The applicability and system requirements of the new optical boundary reconstruction, called OFIT, for use in both feedback control of plasma position and shape and in offline reconstruction tools are discussed.
Cylindrical Hall thrusters with permanent magnets
Authors: Raitses Yevgeny , Merino Enrique , Fisch Nathaniel J.
Published: November 2010

The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction in both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50–300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT.