bluuebunny/crossref_metadata_2025 huggingface dataset:
Douglasien-Provenienzversuch von 1961 in Nordwestdeutschland: Ergebnisse nach 38 Jahren
Authors: Weller Andreas
Published: March 2012

Douglas-fir provenance trials established 1961 in northwestern Germany: findings at the age of 38 years

The Douglas-fir provenance trials established on 14 sites in northwestern Germany in 1961 are the basis for a comparison of 26 North American Douglas-fir provenances. The following assessment criteria were formulated: (1) How do the provenances differ with respect to total volume growth after 38 years? (2) Can climate-induced variations be observed in provenance values? (3) Do provenances differ in regard to branchiness? Because of non-orthogonal trial set-ups and plot-related influences, overall trial sites analysis called for a standardisation of interval-scaled primary data. Relative rank classes were calculated on the basis of a mean plot value. With respect to total volume growth, the provenances Tenas Creek (D47) as well as Molalla (D74) and Timber (D41/59) proved provenances with stable and outstanding productivity. Among the tested local climate elements “long-term annual mean temperature”, “mean annual precipitation” and “height above sea level” only the influence of long-term annual mean temperature is statistically relevant for productivity. Beside hardy ecotypes, which adapt to a wide spectrum of differing plot climates (e.g., Molalla [D74]), there are provenances with poor adaptive capabilities that react sensitively to local climatic conditions (e.g., Salmon Arm II [D46]). For the criterion “fine-branchiness”, the provenances Conrad Creek (D43), Ashford (D67) and Gold Hill (D83) show the best, the provenances Detroit (D76), Carson (D87) and Salmon Arm II (D46) the poorest results.
Iceberg signatures and detection in SAR images in two test regions of the Weddell Sea, Antarctica
Authors: Wesche Christine , Dierking Wolfgang
Published: March 2012

A pixel-based methodology has been established for automatic identification of icebergs in satellite synthetic aperture radar (SAR) images acquired during different seasons and for different sea- ice conditions. This includes, in particular, smaller icebergs (longitudinal axis 100 m to 18.5 km). Investigations were carried out for two test regions located in the Weddell Sea, Antarctica, using images of the Envisat Advanced SAR (ASAR) at HH polarization and of the European Remote-sensing Satellite-2 (ERS-2) SAR (VV-polarized). From the former, a sequence of Image Mode and Wide Swath Mode data are available for the whole of 2006. The ERS data were acquired around the tip of the Antarctic Peninsula in spring and summer months of the years 2000-03. The minimum size of icebergs that could be identified in the IM images was <0.02 km2. Radar backscattering coefficients of icebergs, sea ice and open water were determined separately. We demonstrate that the error in separating icebergs from their surroundings (sea ice or open water) depends on meteorological, oceanographic and sea-ice conditions. Also the pre-processing of the SAR images (e.g. speckle reduction) influences iceberg recognition. Differences in detection accuracy as a function of season could not be substantiated for our test sites, but have in general to be taken into account, as results of other investigations indicate.
Scaling Law for Photon Transmission through Optically Turbid Slabs Based on Random Walk Theory
Authors: Li Xuesong , Ma Lin
Published: March 2012

Past work has demonstrated the value of a random walk theory (RWT) to solve multiple-scattering problems arising in numerous contexts. This paper’s goal is to investigate the application range of the RWT using Monte Carlo simulations and extending it to anisotropic media using scaling laws. Meanwhile, this paper also reiterates rules for converting RWT formulas to real physical dimensions, and corrects some errors which appear in an earlier publication. The RWT theory, validated by the Monte Carlo simulations and combined with the scaling law, is expected to be useful to study multiple scattering and to greatly reduce the computation cost.
Diagnostic Value of 11C-Methionine (MET) and 18F-Fluorothymidine (FLT) Positron Emission Tomography in Recurrent High-Grade Gliomas; Differentiation from Treatment-Induced Tissue Necrosis
Authors: Shishido Hajime , Kawai Nobuyuki , Miyake Keisuke , Yamamoto Yuka , Nishiyama Yoshihiro , Tamiya Takashi
Published: March 2012

We retrospectively evaluated the usefulness of combined measurement of L-methyl-[11C]methionine (MET) and 3'-deoxy-3'-[18F]fluorothymidine (FLT) positron emission tomography (PET) in the differential diagnosis between recurrent gliomas and necrotic lesions. Twenty-one patients with high-grade glioma, previously treated with surgery and radiotherapy with chemotherapy and first radiological suspicion of recurrence were enrolled. The uptake was assessed by the maximum standardized uptake value (SUVmax) and lesion-to-normal tissue count density ratio (L/N ratio). Of the 21 lesions, 15 were diagnosed recurrent gliomas and six were necrotic lesions. The average SUVmax was not significantly different between recurrent gliomas and necrotic lesions on either MET-PET or FLT-PET. The average L/N ratio of recurrent gliomas (3.36 ± 1.06) was significantly higher than that of necrotic lesions (2.18 ± 0.66) on MET-PET (p < 0.01) and the average L/N ratio of recurrent gliomas (7.01 ± 2.26) was also significantly higher than that of necrotic lesions (4.60 ± 1.23) on FLT-PET (p < 0.01). ROC curve analysis showed that the areas under the curves were high but not different between MET- and FLT-PET. PET studies using MET and FLT are useful in the differentiation of recurrent glioma from treatment-induced necrotic lesion. However, there is no complementary information in the differentiation with simultaneous measurements of MET- and FLT-PET.
Short-Circuit Power Reduction by Using High-Threshold Transistors
Authors: Morgenshtein Arkadiy
Published: March 2012

In this brief paper, the dependency of short-circuit power on threshold voltage is analyzed and utilized for short circuit (SC) power reduction in multi-threshold (MTCMOS) processes. Analytical expressions are developed for estimation of the change of ratio between short-circuit power and dynamic power (PSC/Pdyn) while changing the design process. The analysis shows that the PSC/Pdyn ratio can increase significantly if the VT/Vdd ratio in new process decreases. An analytical expression is also derived for estimation of potential SC power reduction in MTCMOS processes by replacing low-VT transistors by high-VT devices in the same process. The proposed technique allows significant reduction of SC power without the need for process shift. The simulation results show good correlation with the analytical estimation at cell level, while demonstrating an average SC power saving of 36%. The performance impact is also validated, showing that timing degradation is minor and controllable. The proposed optimization technique is applicable to any multi-threshold process. The technique is simple for implementation, and can be easily integrated in the existing optimization tools.
THE ANALYSIS OF SEPTIC TANK PERFORMANCE IN REGARD TO SUSPENDED SOLIDS AND ORGANIC MATTER REMOVAL / SEPTIKO VEIKIMO ŠALINANT SKENDINČIĄSIAS IR ORGANINES MEDŽIAGAS ANALIZĖ
Authors: Kirjanova Ala , Rimeika Mindaugas , Dauknys Regimantas
Published: March 2012

The aim of this work was to evaluate the removal of suspended solids (SS) and 7-day biochemical oxygen demand (BOD7) in a three chamber septic tank depending on theoretical wastewater retention time and the degree of septic tank cleanliness. It was found out that the performance of the septic tank depended on the degree of its cleanliness: when the septic tank was clean and retention time was three days, SS and BOS7 removal efficiency was 77±10% and 67±14% respectively, whereas two months later, after septic tank desludging, SS removal efficiency decreased to 53±22% and BOD7 to 32±31%. The performance of the septic tank also depended on theoretical wastewater retention time: when some amount of solids was accumulated at the bottom of the septic tank and wastewater retention time was one day, SS and BOS7 removal efficiency was 45±40% and 33±16% respectively; when retention time was three days, SS removal efficiency increased to 53±22% but BOD7removal efficiency remained similar to one day retention time, i.e. 32±31%.

Santrauka

Bandymų metu buvo įvertintas organinių ir skendinčiųjų medžiagų šalinimas trijų kamerų septike esant vienos ir trijų parų teorinėms nuotekų išbuvimo septike trukmėms bei skirtingam septiko švarumo laipsniui – iš karto po septiko išvalymo, kai jis dar yra švarus, ir praėjus tam tikram laiko tarpui, kai ant septiko dugno yra susikaupęs tam tikras nuosėdų kiekis. Tyrimais nustatyta, kad septiko veikimas priklauso nuo septiko švarumo laipsnio: esant trijų parų nuotekų išbuvimo septike trukmei, vidutinis skendinčiųjų medžiagų (SM) šalinimo efektyvumas buvo 77±10 %, o septynių parų biocheminio deguonies suvartojimo (BDS7) – net 67±14 %, kai septikas buvo švarus, tačiau praėjus dviem mėnesiams nuo septiko išvalymo jo veikimas pablogėjo ir vidutinis SM šalinimo efektyvumas po septiko išvalymo buvo 53±22 %, o BDS7 – 32±31 %. Taip pat nustatyta, kad šalinant teršalus didelę reikšmę turi nuotekų išbuvimo septike trukmė: kai septikas buvo švarus, o nuotekų išbuvimo trukmė trys paros, vidutinis SM šalinimo efektyvumas – 77±10 %, o BDS7 – 67±14 %; sumažinus nuotekų išbuvimo trukmę iki vienos paros, SM šalinimo efektyvumas sumažėjo iki 31±38 %, o BDS7 šalinimo efektyvumas buvo neigiamas.
Arqueología de la Arquitectura y Urbanismo de la ciudad de Oviedo (Asturias, España) entre la Edad Media y el siglo XVIII: el arrabal del Carpio
Authors: Muñiz López Iván
Published: March 2012

La cartografía urbana alcanzó un período de esplendor durante los siglos XVI-XVIII. Esta fuente ha sido empleada en análisis urbanísticos y artísticos a gran escala, pero puede ser también un importante recurso en arqueología de la arquitectura, planteando, además, una reflexión sobre la representación iconográfica de la construcción. El método ha sido aplicado al arrabal del Carpio de la ciudad de Oviedo a partir de un enfoque diacrónico de tiempo largo y un trabajo dividido en tres fases: análisis de fuentes gráficas, escritas y arqueológicas, prospección urbanística y síntesis final. El resultado permite apreciar la evolución del urbanismo y de la arquitectura doméstica entre los siglos XII y XVIII, proponiendo una secuenciación de los ciclos constructivos y su interpretación a partir de los distintos contextos históricos. En este sentido, se resaltan las causas estructurales y sociales por encima de acontecimientos como las catástrofes (incendios, asedios). Las fases de crecimiento económico y consolidación de los grupos de poder tienen gran importancia. Estas jerarquías poseían, además, fuertes intereses especulativos como máximos propietarios de solares e inmuebles e influyeron en la política municipal.
Estudio histórico-estratigráfico de los muros de la nave central de la catedral de Teruel y su encuentro con la techumbre
Authors: De Miguel Alcalá Berta , Pardo Redondo Gabriel
Published: March 2012

Datada entre finales del siglo XII y comienzos del XIII, la Catedral de Teruel es un edificio complejo cuyo destacado tesoro es la techumbre mudéjar que cubre la nave central, declarada Patrimonio Mundial en 1986 por la UNESCO1. De esta magnífica obra de madera policromada se desconocen aspectos tan elementales como quién la construyó, cuándo, cómo y qué representa. Son muchas las teorías que pretenden dilucidar tales incertidumbres y poca la documentación histórica de que se dispone. Durante los años 2008 y 2009, se acometió una restauración que dejó al descubierto parte de la armadura de la cubierta y de los muros que la sustentan. Aprovechando la eliminación temporal de los revestimientos exteriores, se desarrolló un extenso trabajo de análisis estratigráfico y constructivo de los muros de la nave central y de su encuentro con la armadura. Dicho trabajo arroja resultados en torno a las intervenciones llevadas a cabo durante la vida del templo. Del mismo modo, se aportan evidencias que suponen un importante avance en el conocimiento de la fisonomía de la iglesia en sus primeras etapas.
Dal castrum altomedievale al restauro settecentesco: storia e archeologia del castello di Sorrivoli (Roncofreddo - FC)
Authors: Fiorini Andrea
Published: March 2012

No disponible
Materiales y técnicas constructivas en la Murcia andalusí (siglos X-XIII)
Authors: Navarro Palazón Julio , Jiménez Castillo Pedro
Published: March 2012

En el presente trabajo estudiamos la evolución de los materiales y técnicas constructivas en la Murcia andalusí, durante un periodo de tiempo que se extiende entre los siglos X y XIII, para lo que nos basaremos especialmente en la rica información extraída de las numerosas excavaciones efectuadas en dicha ciudad, que se refiere sobre todo a arquitectura residencial. Tras su exhaustivo análisis hemos identificado algunas diferencias entre las fábricas de los siglos X y XI y las posteriores de los siglos XII y XIII, por lo que consideramos importante describirlas, señalando a la vez los elementos que las caracterizan. También trataremos los problemas que plantea la datación absoluta de estos aparejos, señalando los datos seguros de que disponemos al respecto. Con el fin de analizar hasta qué punto son generales estas observaciones o si por el contrario responden más bien a fenómenos de regionalización del registro material andalusí, cotejaremos los datos conseguidos en Murcia con los procedentes de otros yacimientos andalusíes alejados del área de estudio. Finalmente, comprobaremos si existen o no diferencias entre el medio rural y el urbano, y para ello compararemos los materiales y técnicas constructivas presentes en dos yacimientos murcianos coetáneos, distantes 40 kilómetros y situados junto al mismo rio Segura: la ciudad de Murcia (una gran medina) y el despoblado de Siyâsa (un hisn).
«Aqvedvctivm» Una lectura tridimensional en la Forma Urbis Marmorea
Authors: Monterroso Checa Antonio
Published: March 2012

Proponemos seguidamente una lectura volumétrica en la Forma Urbis Marmorea a partir de la descodificación gráfica del dibujo perteneciente a los Arcus Neroniani del Monte Celio; aquí mostrados en los fragmentos 4 ab bajo el nombre «aqvedvctivm». A través de un análisis constructivo y arqueológico detenido, entendemos que es posible restituir aproximativamente su alzado arquitectónico y orografía originaria. Desechamos así la tradicional propuesta que entendía este acueducto cegado por estructuras a él adosadas, teóricamente simbolizadas por las líneas que a derecha del cauce se muestran en este fragmento marmóreo.
Evolución del color en el alero de la fachada del rey D. Pedro I, Real Alcázar de Sevilla. Aportaciones del estudio de materiales a la identificación de las intervenciones de restauración a lo largo de su historia
Authors: López Cruz Olimpia , García Bueno Ana , Medina Flórez Víctor J.
Published: March 2012

Se presenta la investigación realizada en la policromía de la fachada del Palacio de Pedro I, edificio construido en los Reales Alcázares de Sevilla, entre 1356 y 1366, que constituye una de las obras más importantes de la arquitectura andalusí en la Península Ibérica. En esta fachada se han efectuado un gran número de intervenciones en su policromía a lo largo de su historia, pero su aspecto general ha permanecido similar, aunque con variaciones en el detalle. El acabado predominante siempre ha sido el dorado, sobre los colores rojos, azules y verdes. Tras un detallado trabajo de campo y de muestreo, se han combinado diversas técnicas de laboratorio (microscopía óptica con luz reflejada y transmitida, difracción de rayos X, microscopía electrónica de barrido con microanálisis EDX y cromatografías de gases y líquida de alta presión) para la identificación y estudio de las fases inorgánicas y orgánicas que constituyen los pigmentos. Se ha podido confirmar la existencia de, al menos, ocho policromías que definen niveles realizados en épocas diferentes. Cada policromía suele presentar varias capas: de preparación, base y pictórica o lámina de oro, siendo éste último el material más representado como capa de terminación. Las policromías incluyen una amplia variedad de pigmentos: rojo de plomo, cinabrio/bermellón, blanco de plomo, azurita natural y sintética, azul ultramar sintético, malaquita, verde esmeralda, verde de As y Cu, amarillo de plomo y estaño, amarillo de cromo, litargirio y negro orgánico. El estudio textural detallado y la precisa caracterización de los pigmentos ha permitido la datación y la correlación espacial de las sucesivas intervenciones sobre la policromía de la fachada.
Con respecto a los pigmentos originales, se han hallado restos de rojo de plomo y cinabrio seguidos por capas de cinabrio/ bermellón, azurita y malaquita de origen natural. En policromías de etapas intermedias, situadas entre los siglos XVI y XVIII, se ha detectado que el cinabrio es sustituido por bermellón y la azurita natural por sintética. En intervenciones más recientes el pigmento más utilizado es el verde esmeralda (sintetizado en 1814) que constituye un nivel de referencia. A partir de finales del siglo XIX, algunos verdes esmeraldas y azules de azurita sintética son sustituidos por azul ultramar sintético.
Arquitectura defensiva en el Castro de Castromaior (Lugo). Análisis de las técnicas constructivas en el acceso al recinto central del poblado
Authors: López Marcos Miguel Ángel , Álvarez González Yolanda , López González Luis Francisco
Published: March 2012

Se presenta un análisis de técnicas constructivas en el castro prerromano de Castromaior (Lugo), donde se utiliza la metodología arqueológica desde un punto de vista analítico, a través de la excavación sistemática, para llegar a una reconstrucción hipotética de uno de los accesos al poblado. La lectura estratigráfica y la excavación han proporcionado suficientes datos para poder diferenciar fases constructivas. Tras una breve presentación del yacimiento se analizarán los resultados a nivel arqueológico, centrando el estudio en la arquitectura de las estructuras de delimitación. Una vez analizados los resultados, se proyecta una reconstrucción de la zona de entrada. Este pequeño estudio presenta una nueva visión de la edilicia castreña en el noroeste peninsular enfocada desde el punto de vista de la arquitectura de delimitación.
Datando argamasas: tres ejemplos de arquitectura medieval hispana
Authors: Quirós Castillo Juan Antonio , Marzaioli Fabio , Lubritto Carmine
Published: March 2012

Una de las principales problemáticas a las que se enfrenta la arqueología de la arquitectura es datar los elementos y las estructuras. Las argamasas son un tipo de material constituido por una mezcla de diferentes elementos (agregados, agua) y empleadas en muchos tipos de construcciones. Los estudios realizados hasta la actualidad en torno a la posibilidad de realizar dataciones radiocarbónicas precisas han proporcionado resultados contradictorios.
El objetivo de este artículo es el de presentar un nuevo protocolo para datar la arquitectura histórica desarrollado por el Centre for Isotopic Research on Cultural and Enviromental Heritage (CIRCE), basado en la realización de dataciones radiocarbónicas de argamasas a partir del análisis de tres arquitecturas medievales del norte del España, dos iglesias y la muralla de un castillo. Los resultados obtenidos han sido confrontados y comparados con otros indicadores cronológicos independientes (dataciones radiocarbónicas realizadas en los mismos yacimientos, materiales y análisis arqueológicos) con el fin de analizar estos valores desde un enfoque multidisciplinar.
Complications After Cardiovascular Surgery in a Case of Undiagnosed Spinal-Bulbar Muscular Atrophy (Kennedy Disease)
Authors: Skoretz Stacey A. , Yee May-Sann , Martino Rosemary
Published: March 2012

Neurodegenerative diseases are often associated with life-threatening declines in respiratory and swallowing mechanisms. We report the case of a 70-year-old man who had postoperative dysphagia and respiratory failure that required reintubation after coronary artery bypass surgery. Impairment of the patient’s speech, swallowing, and respiratory mechanisms identified during postoperative clinical and instrumental examinations was suggestive of a neurodegenerative disease. Genetic testing confirmed a diagnosis of spinal-bulbar muscular atrophy (Kennedy disease). This case report aims toLhighlight increased morbidity in patients with undiagnosed neuromuscular disorders in the critical care setting and the benefits of vigilant postoperative monitoring and multidisciplinary involvement throughout the care of complex patients.
Hypothesized Cambrian medusae from Saint John, New Brunswick, reinterpreted as sedimentary structures
Authors: Hagadorn James W. , Miller Randall F.
Published: March 2012

More than a hundred radial and discoidal structures occur on bed tops of shales and very fine sandstones of the Cambrian (Series 3) King Square Formation in New Brunswick, Canada. These structures typically contain a central sediment plug, radial lineations that extend outward from the central plug, concentric rings, and a broad trough surrounding or underlying ring margins. Originally interpreted as fossils of scyphozoan medusae, these structures could represent one of only a half-dozen mass strandings documented from the fossil record. Instead, re-evaluation of their sedimentology and morphology suggests that they are likely sedimentary structures known as Astropolithon. These sand-volcano-like structures formed by subsurface blistering, cracking, and failure of a near-surface or surface bed, triggered by the upward movement of gases or other fluids from underlying beds.

RÉSUMÉ

Plus d’une centaine de structures radiales et discoïdes apparaissent au sommet des couches de schiste et de grès très fins de la formation King Square du Cambrien (Série 3), du Nouveau-Brunswick, au Canada. Ces structures contiennent généralement un culot sédimentaire central, des linéaments radiaux qui se déploient vers l’extérieur à partir du culot central, des anneaux concentriques, et une vaste cuvette qui ceinture le bord des anneaux ou qui se trouve en dessous. On estimait initialement qu’il s’agissait de méduses scyphozoaires, mais ces structures pourraient correspondre à l’une de la demi-douzaine d’échouages massifs de l’ichnofaune dont les vestiges fossiles ont été retrouvés. La réévaluation de leur contexte de sédimentation et de leur morphologie porte plutôt à croire que ce sont vraisemblablement des structures sédimentaires connues sous le nom d’astropolithon. Ces structures apparentées à un volcan de sable ont été formées par l’apparition d’alvéoles souterraines, le fendillement et la rupture d’une couche près de la surface ou à la surface, et qu’aurait provoquée le déplacement vers la surface de gaz ou d’autres fluides provenant des couches inférieures.

[Traduit par la redaction]
The Joggins Fossil Cliffs UNESCO World Heritage site: a review of recent research
Authors: Grey Melissa , Finkel Zoe V
Published: March 2012

The Joggins Fossil Cliffs UNESCO World Heritage Site is a Carboniferous coastal section along the shores of the Cumberland Basin, an extension of Chignecto Bay, itself an arm of the Bay of Fundy, with excellent preservation of biota preserved in their environmental context. The Cliffs provide insight into the Late Carboniferous (Pennsylvanian) world, the most important interval in Earth’s past for the formation of coal. The site has had a long history of scientific research and, while there have been well over 100 publications in over 150 years of research at the Cliffs, discoveries continue and critical questions remain. Recent research (post-1950) falls under one of three categories: general geology; paleobiology; paleoecology. It provides a context for future work at the site. While recent research has made large strides in our understanding of the Late Carboniferous, many questions remain to be studied and resolved, and interest in addressing these issues is clearly not waning. Within the World Heritage Site, we suggest that the uppermost formations (Springhill Mines and Ragged Reef), paleosols, floral and trace fossil taxonomy, and microevolutionary patterns are among the most promising areas for future study.

RÉSUMÉ

Le site du patrimoine mondial de l’UNESCO des falaises fossilifères de Joggins est situé sur une partie du littoral qui date du Carbonifère, sur les rives du bassin de Cumberland, qui est une prolongation de la baie de Chignecto, elle-même un bras de la baie de Fundy. L’endroit offre un excellent milieu de préservation de la faune et de la flore dans leur environnement. Les falaises donnent un aperçu du monde du Carbonifère tardif (Pennsylvanien), soit la période de l’histoire de la terre la plus importante pour la formation du charbon. Ces falaises ont fait depuis longtemps l’objet de travaux de recherche scientifique et plus de 100 publications y ont été consacrées au cours de 150 années de recherche. L’endroit suscite encore des découvertes et il soulève toujours des questions essentielles. Les travaux de recherche récents (depuis les années 1950) se répartissent en trois catégories: géologie générale; paléobiologie; et reconstitution des paléomilieux, en plus d’offrir des avenues pour les futurs travaux qui devraient s’y dérouler. Même si la recherche récente a largement contribué à une meilleure compréhension du Carbonifère tardif, de nombreuses questions demeurent sans réponse et commandent qu’on les étudie et les résolve et il est manifeste que l’intérêt pour ces questions est bien loin de s’amenuiser. Sur ce site du patrimoine mondial, nous soutenons que les futurs sujets d’étude les plus prometteurs seraient les formations supérieures (Springhill Mines et Ragged Reef), les paléosols, la taxonomie florale et des ichnofossiles, ainsi que les paramètres de microévolution.

[Traduit par la redaction]
Implications of the O + OH reaction in hydroxyl nightglow modeling
Authors: Caridade P. J. S. B. , Horta J.-Z. J. , Varandas A. J. C.
Published: March 2012

Abstract. The hydroxyl nightglow has been examined anew using more realistic estimates of the rate constants for the key reactive and inelastic OH(v') + O quenching processes, which have been obtained from quasiclassical trajectories run on the adiabatic ab initio-based realistic DMBE-IV potential energy surface for the ground state of the hydroperoxil radical. Significant differences in the vertical profiles of vibrationally excited hydroxyl radicals are obtained relative to the ones predicted by Adler-Golden (1997) when employing an OH(v') + O effective rate constant fixed at twice the experimental value for v' = 1. Other limiting cases reported in the literature are also discussed. Additionally, the validity of the steady-state hypothesis is analysed by comparing with the results obtained via numerical integration of the master equations.
Study of the diurnal variability of atmospheric chemistry with respect to boundary layer dynamics during DOMINO
Authors: van Stratum B. J. H. , Vilà-Guerau de Arellano J. , Ouwersloot H. G. , van den Dries K. , van Laar T. W. , Martinez M. , Lelieveld J. , Diesch J.-M. , Drewnick F. , Fischer H. , Hosaynali Beygi Z. , Harder H. , Regelin E. , Sinha V. , Adame J. A. , Sörgel M. , Sander R. , Bozem H. , Song W. , Williams J. , Yassaa N.
Published: March 2012

Abstract. We study the interactions between atmospheric boundary layer (ABL) dynamics and atmospheric chemistry using a mixed-layer model (MXLCH) coupled to chemical reaction schemes. Guided by both atmospheric and chemical measurements obtained during the DOMINO campaign (2008), numerical experiments are performed to study the role of ABL dynamics and the accuracy of chemical schemes with different complexity: MOZART-4 and a reduced mechanism of this chemical system. Both schemes produce satisfactory results, indicating that the reduced scheme is capable of reproducing the O3-NOx-VOC-HOx diurnal cycle during conditions characterised by a low NOx regime and small O3 tendencies (less than 1 ppb per hour). By focussing on the budget equations of chemical species in the mixed-layer model, we show that for species like O3, NO and NO2, the influence of entrainment and boundary layer growth is of the same order as chemical production/loss. This indicates that an accurate representation of ABL processes is crucial in understanding the daily cycle of chemical species. By comparing the time scales of chemical reactive species with the mixing time scale of turbulence, we propose a classification based on the Damköhler number to further determine the importance of dynamics on chemistry during field campaigns. Our findings advocate an integrated approach, simultaneously solving the ABL dynamics and chemical reactions, in order to obtain a better understanding of chemical pathways and processes and the interpretation of the results obtained during measurement campaigns.
Aspect sensitivity of polar mesosphere summer echoes based on ESRAD MST radar measurements in Kiruna, Sweden in 1997–2010
Authors: Smirnova M. , Belova E. , Kirkwood S.
Published: March 2012

Abstract. Aspect sensitivities of polar mesosphere summer echoes (PMSE) measured with the ESRAD 50 MHz radar in 1997–2010 are studied using the full correlation analysis technique. Half of PMSE detected each year are found to be highly aspect sensitive. Yearly median values of the aspect sensitivity parameter θs, characterising the half-width of the scatterers' polar diagram, are 2.9–3.7° depending on the year. The other half of the PMSE have θs values larger than 9–11° and cannot be evaluated using the ESRAD vertical beam only. PMSE aspect sensitivity reveals an altitude dependence, namely, the scatter becomes more isotropic with increasing height. This result is consistent with that reported in other studies. No dependence of PMSE aspect sensitivity on backscattered power for any year was identified. In the paper the limitations of the in-beam and off-vertical beam methods for estimation of PMSE aspect sensitivity are discussed. We conclude that both methods should be combined in order to get complete information about PMSE aspect sensitivity and to estimate correctly PMSE absolute strength.
The imprint of surface fluxes and transport on variations in total column carbon dioxide
Authors: Keppel-Aleks G. , Wennberg P. O. , Washenfelder R. A. , Wunch D. , Schneider T. , Toon G. C. , Andres R. J. , Blavier J.-F. , Connor B. , Davis K. J. , Desai A. R. , Messerschmidt J. , Notholt J. , Roehl C. M. , Sherlock V. , Stephens B. B. , Vay S. A. , Wofsy S. C.
Published: March 2012

Abstract. New observations of the vertically integrated CO2 mixing ratio, ⟨CO2⟩, from ground-based remote sensing show that variations in CO2⟩ are primarily determined by large-scale flux patterns. They therefore provide fundamentally different information than observations made within the boundary layer, which reflect the combined influence of large-scale and local fluxes. Observations of both ⟨CO2⟩ and CO2 concentrations in the free troposphere show that large-scale spatial gradients induce synoptic-scale temporal variations in ⟨CO2⟩ in the Northern Hemisphere midlatitudes through horizontal advection. Rather than obscure the signature of surface fluxes on atmospheric CO2, these synoptic-scale variations provide useful information that can be used to reveal the meridional flux distribution. We estimate the meridional gradient in ⟨CO2⟩ from covariations in ⟨CO2⟩ and potential temperature, θ, a dynamical tracer, on synoptic timescales to evaluate surface flux estimates commonly used in carbon cycle models. We find that simulations using Carnegie Ames Stanford Approach (CASA) biospheric fluxes underestimate both the ⟨CO2⟩ seasonal cycle amplitude throughout the Northern Hemisphere midlatitudes and the meridional gradient during the growing season. Simulations using CASA net ecosystem exchange (NEE) with increased and phase-shifted boreal fluxes better fit the observations. Our simulations suggest that climatological mean CASA fluxes underestimate boreal growing season NEE (between 45–65° N) by ~40%. We describe the implications for this large seasonal exchange on inference of the net Northern Hemisphere terrestrial carbon sink.
Stochastic analysis of field-scale heat advection in heterogeneous aquifers
Authors: Chang C.-M. , Yeh H.-D.
Published: March 2012

Abstract. Owing to the analogy between the solute and heat transport processes, it can be expected that the rate of growth of the spatial second moments of the heat flux in a heterogeneous aquifer over relatively large space scales is greater than that predicted by applying the classical heat transport model. The motivation of stochastic analysis of heat transport at the field scale is therefore to quantify the enhanced growth of the field-scale second moments caused by the spatially varying specific discharge field. Within the framework of stochastic theory, an effective advection-dispersion equation containing effective parameters (namely, the macrodispersion coefficients) is developed to model the mean temperature field. The rate of growth of the field-scale spatial second moments of the mean temperature field in the principal coordinate directions is described by the macrodispersion coefficient. The variance of the temperature field is also developed to characterize the reliability to be anticipated in applying the mean heat transport model. It is found that the heterogeneity of the medium and the correlation length of the log hydraulic conductivity are important in enhancing the field-scale heat advection, while the effective thermal conductivity plays the role in reducing the field-scale heat advection.
Numerical models of trench migration in continental collision zones
Authors: Magni V. , van Hunen J. , Funiciello F. , Faccenna C.
Published: March 2012

Abstract. Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. We perform a parametric study of the geometrical and rheological influence on subduction dynamics during the subduction of continental lithosphere. In 2-D numerical models of a free subduction system with temperature and stress-dependent rheology, the trench and the overriding plate move self-consistently as a function of the dynamics of the system (i.e. no external forces are imposed). This setup enables to study how continental subduction influences the trench migration. We found that in all models the trench starts to advance once the continent enters the subduction zone and continues to migrate until few million years after the ultimate slab detachment. Our results support the idea that the trench advancing is favoured and, in part provided by, the intrinsic force balance of continental collision. We suggest that the trench advance is first induced by the locking of the subduction zone and the subsequent steepening of the slab, and next by the sinking of the deepest oceanic part of the slab, during stretching and break-off of the slab. The amount of trench advancing ranges from 40 to 220 km and depends on the dip angle of the slab before the onset of collision.
Hunger Games: What Are the Chances?
Authors: Bush Sarah B. , Karp Karen S.
Published: March 2012

The mathematics found in the popular adolescent book and movie gives students another way to view probability.
Expanding the scope of anatomical sciences: The case of “Human evolution: The fossil evidence” course at the Sackler School of Medicine, Tel‐Aviv University
Authors: Notzer Netta , Abramovitz Ruth
Published: March 2012

The Anatomy Department at Tel‐Aviv University Medical School offers its students an elective course of 26 didactic hours on human evolution. The course is open to students from all faculties, who must fulfill all academic requirements, without a prerequisite of a background in anatomy. Approximately 120 students attend annually, a third of them are nonmedical students who major in philosophy, archeology, and sociology. This article discusses the course's contributions to students' understanding of a scientific concept that a scientific theory can be contradicted by new evidence, because facts govern science. Also, research methods of applying scientific principles establish the understanding of the human body, which evidently contributes to health and medicine. In the classes, the students are divided into mini‐groups of 2–3 students, while the lecturer moves among students to examine fossils. In addition, analogies, open‐discussions, and explanations accompany the tangible experiences. The lecturer of the course is an experienced anthropologist–anatomist researcher. He is a role‐model and a mentor, sharing with the students his belief that a scientist should be persistent in his research to overcome difficult circumstances. Students, regardless of their backgrounds, express high appreciation of the course in their feedback questionnaires. The message conveyed by this course is that not only knowledge counts but also its integration with scientific principles. This course teaches us that science can bring students from different areas to study together and share ideas. In conclusion, this is a unique course in the eyes of the faculty and students alike. Anat Sci Educ. © 2012 American Association of Anatomists.
Anatomical Sciences Education Vol. 5, Issue 2, 2012 Cover Image
Authors: Samalia Latika , Stringer Mark D.
Published: March 2012

The dissecting competition in progress at the Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand. In this issue of ASE, Drs. Samalia and Stringer describe a dissecting competition for third year medical students. Working alone, students undertake a detailed dissection during a single weekend day and present an appropriately labeled prosection, together with a 300 word abstract emphasizing the clinical relevance of their work. Dissections are judged on presentation, accuracy of labeling, and relevance to the clinical abstract.
A multi‐class mean‐excess traffic equilibrium model with elastic demand
Authors: Xu Xiangdong , Chen Anthony , Zhou Zhong , Cheng Lin
Published: March 2012

Recent empirical studies have revealed that travel time variability plays an important role in travelers' route choice decisions. To simultaneously account for both reliability and unreliability aspects of travel time variability, the concept of mean‐excess travel time (METT) was recently proposed as a new risk‐averse route choice criterion. In this paper, we extend the mean‐excess traffic equilibrium model to include heterogeneous risk‐aversion attitudes and elastic demand. Specifically, this model explicitly considers (1) multiple user classes with different risk‐aversions toward travel time variability when making route choice decisions under uncertainty and (2) the elasticity of travel demand as a function of METT when making travel choice decisions under uncertainty. This model is thus capable of modeling travelers' heterogeneous risk‐averse behaviors with both travel choice and route choice considerations. The proposed model is formulated as a variational inequality problem and solved via a route‐based algorithm using the modified alternating direction method. Numerical analyses are also provided to illustrate the features of the proposed model and the applicability of the solution algorithm. Copyright © 2012 John Wiley & Sons, Ltd.
Cyclohexane Ring as a Tool to Select the Presentation of the Carbohydrate Moiety in Glycosyl Amino Acids
Authors: Rodríguez Fernando , Somovilla Víctor J. , Corzana Francisco , Busto Jesús H. , Avenoza Alberto , Peregrina Prof Jesús M.
Published: March 2012

The design of mimic molecules that resemble natural products can be a useful tool to help understand the key aspects in molecular recognition processes that are difficult to access by using natural derivatives. We present the synthesis and the conformational analysis of different glucosylated diamide amino acids that simulate glycopeptides with β‐O‐linked glucose and contain the nonnatural β‐hydroxycyclohexane‐α‐amino acid. The study, using NMR experiments, X‐ray spectroscopy, and molecular dynamics simulations, reveals that the cyclohexane ring allows some naturally occurring ways of presentation of the carbohydrate to be fixed, or to stabilize some novel conformations. In addition, different chair conformations for the cyclohexane‐α‐amino acid moiety can be set, in particular, those with high population of conformers in which the bulky groups are located at axial positions. Moreover, to increase the scope of these cyclohexane derivatives, two dipeptides incorporating the glycomimics have been synthesized and further glycosylated to obtain the corresponding α‐O‐glycopeptides. These features can have important implications for the design of new drugs and for understanding the complex molecular processes that take place between glycopeptides and their biological targets.
ChemInform Abstract: BH3 under Pressure: Leaving the Molecular Diborane Motif
Authors: Yao Yansun , Hoffmann Roald
Published: March 2012

theoretic study using MP2 and DFT methods
ChemInform Abstract: ReO2Cl(S2O7), a Molecular Disulfate.
Authors: Betke Ulf , Dononelli Wilke , Kluener Thorsten , Wickleder Mathias S.
Published: March 2012

The title compound is synthesized from a solution of ReCl5 in oleum containing 65% SO3 (150 °C, 48 h).
ChemInform Abstract: Cr6+‐Containing Phases in the System CaO—Al2O3—CrO42‐—H2O at 23 °C.
Authors: Poellman Herbert , Auer Stephan
Published: March 2012

The new phases 3CaO·Al2O3·1/2CaCrO4 ·1/2Ca(OH)2·nH2O, 3CaO·Al2O3·CaCrO4 ·nH2O, and 3CaO·Al2O3·1/6CaCrO4 ·5/6Ca(OH)2·nH2O are identified in the title system.
ChemInform Abstract: Mn(I) in an Extended Oxide: The Synthesis and Characterization of La1‐xCaxMnO2+δ (0.6 ≤ x ≤ 1).
Authors: Dixon Edward , Hadermann Joke , Ramos Silvia , Goodwin Andrew L. , Hayward Michael A.
Published: March 2012

The title materials are prepared by solid state reduction of La1‐xCaxMnO3 with NaH (210 °C, 168 h).
ChemInform Abstract: Synthesis, Crystal Chemistry and Magnetism of the Metal‐Rich Borides MxRh7‐xB3 (M: Cr, Mn, Ni; x = 0.39—1) with Th7Fe3‐Type Structure.
Authors: Misse Patrick R. N. , Dronskowski Richard , Fokwa Boniface P. T.
Published: March 2012

The title compounds are synthesized by arc‐melting of the elements and characterized by powder XRD and single crystal XRD of Cr0.78Rh6.22B3 and Mn0.39Rh6.61B3.
ChemInform Abstract: Selective Catalytic Hydrogenation of Nitro Groups in the Presence of Activated Heteroaryl Halides.
Authors: Kasparian Annie J. , Savarin Cecile , Allgeier Alan M. , Walker Shawn D.
Published: March 2012

An efficient and widely applicable method is presented
ChemInform Abstract: Friedel—Crafts‐Type Alkylation with Bromodifluoro(phenylsulfanyl)methane Through α‐Fluorocarbocations: Syntheses of Thioesters, Benzophenones and Xanthones.
Authors: Kuhakarn Chutima , Surapanich Nakin , Kamtonwong Siriporn , Pohmakotr Manat , Reutrakul Vichai
Published: March 2012

Thioether (II) is applied as synthetic equivalent of thioester cation PhS‐CO+ and geminal carbonyl dication CO2+ in the Friedel—Crafts alkylation of a variety of activated aromatic compounds (12 examples).
ChemInform Abstract: Conjugate Addition of Arylboronic Acids to α,β‐Unsaturated Carbonyl compounds in Aqueous Medium Using Pd(II) Complexes with Dihydroxy‐2,2′‐bipyridine Ligands: Homogeneous or Heterogeneous Nano‐Catalysis?
Authors: Tomas‐Mendivil Eder , Diez Josefina , Cadierno Victorio
Published: March 2012

A new green palladium catalytic system (I) for the conjugate addition of aryl boronic acids to α,β‐unsaturated carbonyl compounds in water under air is developed.
ChemInform Abstract: Asymmetric Synthesis of Highly Functionalized Cyclopentanes by a Rhodium‐ and Scandium‐Catalyzed Five‐Step Domino Sequence.
Authors: Parr Brendan T. , Li Zhanjie , Davies Huw M. L.
Published: March 2012

Highly functionalized cyclopentanes with four new stereogenic centers are synthesized and obtained as single diastereomers by the present new method involving five distinct steps.
ChemInform Abstract: Transition Metal‐Free TEMPO‐Catalyzed Oxidative Cross‐Coupling of Nitrones with Alkynyl‐Grignard Reagents.
Authors: Murarka Sandip , Studer Armido
Published: March 2012

Treatment of nitrones with alkynyl Grignard reagent in the presence of stoichiometric or catalytic amounts of TEMPO allows an efficient access to alkynylated nitrones.
ChemInform Abstract: Carbohydrate‐Based Pseudo‐Dipeptides: New Ligands for the Highly Enantioselective Ru‐Catalyzed Transfer Hydrogenation Reaction.
Authors: Coll Mercedes , Pamies Oscar , Adolfsson Hans , Dieguez Montserrat
Published: March 2012

Ruthenium‐complexes of novel carbohydrate based pseudo‐dipeptide ligands selectively catalyze the reduction of aryl‐alkyl ketones (I) under transfer‐hydrogenation conditions.
ChemInform Abstract: HClO4—SiO2 as an Efficient and Recyclable Catalyst for the Synthesis of Amide Derivatives.
Authors: Song Weibin , Ma Lei , Hu Lihong
Published: March 2012

Silica‐supported perchloric acid is shown to be an efficient catalyst for the alkylation of amides and sulfonamides.
ChemInform Abstract: Palladium‐Catalyzed C—H Acetoxylation of 2‐Methoxyimino‐2‐aryl‐acetates and Acetamides.
Authors: Wang Liang , Xia Xu‐Dong , Guo Wei , Chen Jia‐Rong , Xiao Wen‐Jing
Published: March 2012

The direct C—H acetoxylation of the title compounds affords the oxidative coupling products in moderate to good yields.
ChemInform Abstract: Room‐Temperature Synthesis of Tetra‐ortho‐Substituted Biaryls by NHC‐Catalyzed Suzuki—Miyaura Couplings.
Authors: Wu Linglin , Drinkel Emma , Gaggia Fiona , Capolicchio Samanta , Linden Anthony , Falivene Laura , Cavallo Luigi , Dorta Reto
Published: March 2012

The new NHC ligand with appropriately substituted naphthyl side chains is able to perform the Suzuki—Miyaura coupling to form bulky tetra‐ortho‐substituted biaryls from aryl bromides and chlorides.
ChemInform Abstract: Enantioselective Rhodium‐Catalyzed Arylation of Electron‐Deficient Alkenylarenes.
Authors: Saxena Aakarsh , Lam Hon Wai
Published: March 2012

A novel dibenzylamide‐containing chiral diene ligand is used in enantioselective arylation reactions of several β‐substituted nitroarenes with arylboronic acids (II).
ChemInform Abstract: A Convergent Approach to Polycyclic Aromatic Hydrocarbons.
Authors: Guignard Raphael F. , Zard Samir Z.
Published: March 2012

Radical addition and cyclization of xanthates (II) and (XII) affords ketones (III) and (XIII), respectively.
ChemInform Abstract: Synthesis of Rare Earth Catalysts and Their Applications for Enantioselective Synthesis of Heterocyclic β‐Amino Alcohols.
Authors: Martin Myriam , El Hellani Ahmad , Yang Jing , Collin Jacqueline , Bezzenine‐Lafollee Sophie
Published: March 2012

The new complexes are efficient catalysts for the asymmetric aminolysis of heterocyclic epoxides.
ChemInform Abstract: Bicyclization of Isocyanides: A Synthetic Strategy for Fused Pyrroles.
Authors: Zhang Lingjuan , Xu Xianxiu , Xia Wenming , Liu Qun
Published: March 2012

Treatment of ketene dithioacetals of type (I) and (IV) with tosylmethyl isocyanides allows a simple, new, and mild access to cyclopentapyrroles like (III) and (V).
ChemInform Abstract: Organocatalyzed Cycloaddition of Carbon Dioxide to Aziridines.
Authors: Wu Yichen , Liu Guosheng
Published: March 2012

DBN is reported to be an efficient catalyst for the process.
ChemInform Abstract: Organocatalytic Synthesis of 1,2,3‐Triazoles from Unactivated Ketones and Arylazides.
Authors: Belkheira Mokhtaria , El Abed Douniazad , Pons Jean‐Marc , Bressy Cyril
Published: March 2012

An organocatalytic version to Huisgen′s metal‐catalyzed triazole synthesis is described using unactivated ketones and arylazides as the substrates and proline as an organocatalyst.
ChemInform Abstract: A Chiral Pool Strategy for the Synthesis of Enantiopure Hydroxymethyl‐Substituted Pyridine Derivatives.
Authors: Eidamshaus Christian , Reissig Hans‐Ulrich
Published: March 2012

The method is based on the TmsOTf‐promoted cyclocondensation of β‐ketoenamides.