bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping soil erosion using magnetic susceptibility. A case study in Ukraine
Authors: Nazarok P. , Kruglov O. , Menshov O. , Kutsenko M. , Sukhorada A.
Published: March 2014

Abstract. The intrinsic element grouping of the magnetic susceptibility (MS) values is conducted. The relation between MS values and erosion index is shown. The objective of the investigation is study of the information about magnetic susceptibility of soils as a diagnostic criterion to erodibility. The investigations were conducted in the limits of Tcherkascy Tishki territory, Kharkiv district. The soils of the territory are presented by catenary row of chernozems. The study area was used in the field crop rotation. The soil conservation technologies have not been applied. The data analyze confirmed high correlation of the MS, erosive index and humus content. The possibility of MS cartogram using at the soil erodibility map is presented. The magnetic methods can be extensively used at the soil erosion investigations thanks to the speed and low cost.
Occupy Oakland and #oo: Uses of Twitter within the Occupy movement
Authors: Croeser Sky , Highfield Tim
Published: March 2014

Social media have become crucial tools for political activists and protest movements, providing another channel for promoting messages and garnering support. Twitter, in particular, has been identified as a noteworthy medium for protests in countries including Iran and Egypt to receive global attention. The Occupy movement, originating with protests in, and the physical occupation of, Wall Street, and inspiring similar demonstrations in other U.S. cities and around the world, has been intrinsically linked with social media through location–specific hashtags: #ows for Occupy Wall Street, #occupysf for San Francisco, and so on. While the individual protests have a specific geographical focus–highlighted by the physical occupation of parks, buildings, and other urban areas — Twitter provides a means for these different movements to be linked and promoted through tweets containing multiple hashtags. It also serves as a channel for tactical communications during actions and as a space in which movement debates take place.This paper examines Twitter’s use within the Occupy Oakland movement. We use a mixture of ethnographic research through interviews with activists and participant observation of the movements’ activities, and a dataset of public tweets containing the #oo hashtag from early 2012. This research methodology allows us to develop a more accurate and nuanced understanding of how movement activists use Twitter by cross–checking trends in the online data with observations and activists’ own reported use of Twitter. We also study the connections between a geographically focused movement such as Occupy Oakland and related, but physically distant, protests taking place concurrently in other cities. This study forms part of a wider research project, Mapping Movements, exploring the politics of place, investigating how social movements are composed and sustained, and the uses of online communication within these movements.
The behavior of tillage tools with acute and obtuse lift angles
Authors: Abbaspour-Fard Mohammad Hossein , Hoseini Sayed Ali , Aghkhani Mohammad Hossein , Sharifi Ahmad
Published: March 2014

An experimental investigation was conducted to study the trend of draft force against forward speed and working depth for a range of lift angles beyond acute angles for a simple plane tillage tool. The experiments were performed in an indoor soil bin facility equipped with a tool carriage and a soil preparation unit propelled by an integrated hydraulic power system. The system was also equipped with electronic instrumentation including an Extended Octagonal Ring Transducer (EORT) and a data logger. The factorial experiment (4×3×3) with three replications was used based on Randomized Complete Block Design (RCBD). The independent variables were lift angle of the blade (45, 70, 90 and 120°), forward speed (2, 4 and 6 km h-1) and working depth (10, 25 and 40 cm). The variance analysis for the draft force shows that all independent variables affect the draft force at 1% level of significance. The trend of the draft force against working depth and forward speed had almost a linear increase. However, the trend of the draft force against the lift angle is reversed for lift angles >90. This finding, conflicts with the results of analytical and numerical studies which extrapolate the results achieved for acute lift angles to obtuse lift angles and have not been reported experimentally.
The extent of increase in first calving age as a result of implementing various sexed semen breeding strategies
Authors: Joezy-Shekalgorabi Sahereh , Shadparvar Abdol Ahad , De Vries Albert , Gay Keegan Douglas
Published: March 2014

A deterministic simulation was conducted to assess the effects of sexed semen utilization strategies on age at first calving (AFC). Four different strategies were implemented on dairy heifers: continuous use of conventional semen only (CC), continuous use of sexed semen only (SS), utilization of sexed semen for both the first and second services with conventional semen afterwards (S2), and utilization of sexed semen for the first service with conventional semen afterwards (S1). Results indicated that continuous utilization of sexed semen led to the greatest AFC; however at high conception rates, strategies displayed negligible differences on AFC. Increases in estrus detection rate had the greatest effects on decreasing AFC of the SS scenarios. Negative effect of sexed semen on AFC increased when the effect of low estrus detection rate was combined with low conception rate of sexed semen. Results indicated that in the case of access to sexed semen conception rate, prediction of AFC is possible by quadratic polynomial or exponential equations, depending to the applied breeding strategy. Simultaneous utilization of sexed and conventional semen in a herd did not make a substantial change in AFC when a low percentage of sexed semen was employed. Increasing the contribution of different sexed semen strategies led to higher AFC variation, especially for the SS strategy. AFC of strategies that utilize sexed semen is highly dependent on the conception rate, estrus detection rate and the contribution of sex sorted semen in the total number of inseminations of the heifer herd.
Pyrenean meadows in Natura 2000 network: grass production and plant biodiversity conservation
Authors: Reiné Ramón , Barrantes Olivia , Chocarro Cristina , Juárez Alejandro , Broca Alfonso , Maestro Melchor , Carlos Ferrer
Published: March 2014

In semi-natural mountain meadows, yield and forage quality must be reconciled with plant biodiversity conservation. This study was performed to analyze the relationships between these three parameters. To quantify plant biodiversity and pastoral value (PV), phytosociological inventories were performed in 104 semi-natural meadows in the Central Spanish Pyrenees included in the Natura 2000 network. Forage yields were calculated and forage samples were analyzed for relative feed value (RFV). We identified two main types of meadows: (i) those that had “more intensive management,” relatively close to farm buildings, with little or no slope, dominated by grasses, with low plant biodiversity, high PV and yield, but low forage quality and (ii) those that had “less intensive management,” distant from farm buildings, on slopes, richer in “other forbs”, with high plant biodiversity and forage quality, but low PV and yield. Conservation policies should emphasize less intensive management practices to maintain plant diversity in the semi-natural meadows in the Pyrenees. The widespread view that “other forbs” have low nutritional value should be revised in future research. These species often are undervalued by the PV method, because their nutritional quality, digestibility and intake are poorly understood.
Modelling infiltration and geostatistical analysis of spatial variability of sorptivity and transmissivity in a flood spreading area
Authors: Haghighi Fashi Fereshte , Sharifi Forood , Kamali Koorosh
Published: March 2014

Knowledge of infiltration characteristics is useful in hydrological studies of agricultural soils. Soil hydraulic parameters such as steady infiltration rate, sorptivity, and transmissivity can exhibit appreciable spatial variability. The main objectives of this study were to examine several mathematical models of infiltration and to analyze the spatial variability of observed final infiltration rate, estimated sorptivity and estimated transmissivity in flood spreading and control areas in Ilam province, Iran. The suitability of geostatistics to describe such spatial variability was assessed using data from 30 infiltration measurements sampled along three lines. The Horton model provided the most accurate simulation of infiltration considering all measurements and the Philip’s two-term model provided less accurate simulation. A comparison of the measured values and the estimated final infiltration rates showed that the Kostiakov-Lewis, Kostiakov, and SCS models could not estimate the final infiltration rate as well as Horton model. Estimated sorptivity and transmissivity parameters of the Philip’s two-term model and final infiltration rate had spatial structure, and were considered to be structural variables over the transect pattern. The Gaussian model provided the best-fit theoretical variogram for these three parameters. Variogram values ranged from 99 and 88 m for sorptivity and final infiltration rate to 686 (spherical) and 384 m (Gaussian) for transmissivity. Sorptivity, transmissivity and final infiltration attributes showed a high degree of spatial dependence, being 0.99, 0.81 and 1, respectively. Results showed that kriging could be used to predict the studied parameters in the study area.
Influence of farming system and production purpose on the morphostructure of Spanish goat breeds
Authors: Gonzalez-Martinez Ana , Herrera Mariano , Luque Manuel , Rodero Evangelina
Published: March 2014

The aim of this study was to examine the possible influence of farming systems, based on the morphostructure of 1,571 female goats drawn from 40 flocks containing seven Spanish breeds (Blanca Andaluza, Blanca Celtiberica, Negra Serrana, Pirenaica, Payoya, Murciano-Granadina and Malagueña) raised under four different farming systems. Analysis of morphometric variables showed that the morphostructure of native Spanish goat breeds was linked to the farming system used and thus to the production purpose. The morphostructure of grazing breeds may be more influenced by natural selection within the physical environment and less by human selection. That of stall-fed breeds, by contrast, reflects intense artificial selection aimed at achieving a highly-productive dairy type. For this reason, morphological evaluation systems used in breeding programmes for meat or dual-purpose goat breeds farmed extensively or semi-extensively should be specific, and should reflect the influence of the environment in which these goats are farmed.
Estimation of genetic parameters for morphological and functional traits in a Menorca horse population
Authors: Solé Marina , Cervantes Isabel , Gutiérrez Juan Pablo , Gómez Maria Dolores , Valera Mercedes
Published: March 2014

Functional conformation and performance in Classic and Menorca Dressage are the main selection criteria in the Menorca Horse breeding program. Menorca Dressage is an alternative Classical Dressage discipline which is exclusive of the Menorca Island, but including a series of movements that the animals perform in the traditional festivities called “Jaleo Menorquín”. One of these movements involves the horse raising its forelimbs and standing or walking on its hindlimbs, which is called “el bot”. To make the Menorca horse breed more competitive in the equestrian market, it is necessary to understand the genetic background that characterizes the aptitude for Menorca Dressage and its relationship with conformation traits. The analysed data consisted of 15 conformation traits from 347 Menorca horses (200 males and 147 females), with 1,550 performance records in Menorca Dressage competitions. Genetic parameters were estimated using linear and threshold animal models. The heritabilities for heights and lengths were high (0.45-0.76), those for angulations and binary conformation traits were low to moderate (0.10-0.36) as were the scores for dressage performance (0.13-0.21). The results suggest that the analyzed traits could be used as an efficient tool for selecting breeding horses.
Global change and viticulture in the Mediterranean region: a case of study in north-eastern Spain
Authors: Lopez-Bustins Joan-Albert , Pla Eduard , Nadal Montserrat , De Herralde Felicidad , Savé Robert
Published: March 2014

Viticulture in the Mediterranean region has been improved by agronomic methods based on ecophysiological and genetic knowledge of the species and varieties cultivated. Plant growth, yield and quality are highly dependent on climate. Grape sugar content and wine alcohol content are considered as important quality parameters. The objective of our study is to analyse the effects of the current global change on the percentage of alcohol by volume (ABV) in red wines from vineyards located in the Montsant Designation of Origin (DO) (Priorat County, north-eastern Spain). We present an annual series of percentage of ABV in red wines over the 1984-2008 period (25 years), which is one of the longest series of this viticultural variable in Spain. We do not detect any significant trend of alcohol levels in red wines from the Montsant DO along the 1984-2004 subperiod, but a sharp increase about 1% (by volume) is observed after 2004; we statistically checked that the last four years constitute an outlier period in the series. We consider climate evolution over the 1984-2004 period in the study area in order to find some relation with alcohol levels in red wines. Agronomic practices and land cover changes are also taken into account. Results show that the interannual variability of the alcohol levels in red wines are partially explained by temperature and precipitation conditions few days before the vintage. The high percentages of ABV since 2005 may be associated with new trends in viticulture techniques rather than with climate change.
Displacement of Aphytis chrysomphali by Aphytis melinus, parasitoids of the California red scale, in the Iberian Peninsula
Authors: Boyero Juan Ramon , Vela Jose Miguel , Wong Eva , Garcia Ripoll Carlos , Verdú Maria Jesús , Urbaneja Alberto , Vanaclocha Pilar
Published: March 2014

Parasitoids are the main natural enemies of the California red scale, Aonidiella aurantii (Maskell) and on occasion can regulate their populations. To increase their effectiveness, inoculative or augmentative releases of parasitoids are promoted. Previous to the implementation of any release strategy an important and necessary step is to acquire knowledge on the parasitoid fauna associated with this key phytophagous pest. Parasitoids were surveyed and quantified in Spanish citrus orchards between 2005 and 2009. Aphytis melinus DeBach (87.1%) resulted as the dominant species, followed by Aphytis chrysomphali (Mercet) (15.9%), Encarsia perniciosi (Tower) (2.4%) and Aphycus hederaceus (Westwood) (0.004%). Overall, higher levels of parasitism were recorded in fruit than in twigs. Scales in fruit were parasitized at similar levels by the different parasitoid species whereas E. perniciosi was more active in twigs. Data eventually reveal the recent displacement of A. chrysomphali by A. melinus. The implications of these results on the biological control of A. aurantii are discussed and this information will be useful in the decision of IPM strategies for this pest.
Příklad výzkumu žákovských představ v české syntaxi
Authors: Štěpáník S.
Published: March 2014

Cílem empirické studie je popsat výzkum představ žáka střední školy ve vybrané partii syntaktického učiva, konkrétně vztahů v souřadném souvětí, a reflektovat její současné didaktické zpracování v učebnicích i vyučovacím procesu. Jako výzkumný analytický rámec byl zvolen model didaktické rekonstrukce, jak jej popisuje Jelemenská, Sander a Kattmann (2003). Nejprve je představen výzkumný problém v obecné rovině, následuje bližší seznámení s problematikou z pohledu školní praxe. Dále je popsána metodologie výzkumu a jeho výsledky. Závěr tvoří shrnutí a diskuze výsledků a doporučení pro vyučování. Z výsledků výzkumu vyplývá, že tradiční postup při výuce zmíněné problematiky nedostatečně odráží komunikační zkušenosti žáků a jejich dosavadní poznání, neusiluje o její skutečné pochopení a rovněž neodpovídá požadavkům moderní didaktiky českého jazyka, neboť opomíjí komunikační cíl. Rozpory, které panují v této oblasti v akademickém diskurzu, nicméně jsou pro potřeby školské praxe zpřehledněny, se projevily také v myšlení zkoumaného subjektu. Výzkum ukazuje, že zásady fungování češtiny, o jejichž osvojení žáky škola usiluje, jsou snáze uchopitelné za podmínky, že vyučování pracuje s jazykovou výbavou žáků jako rodilých mluvčích a podporuje skutečné pochopení probíraného učiva na základě hluboké kognitivní činnosti.
Užívání nových učebnicových materiálů učiteli 1. stupně ZŠ
Authors: Stará J. , Krčmářová T.
Published: March 2014

Cílem empirické studie je prezentovat výsledky výzkumu výuky nového přírodovědného tématu učiteli 1. stupně ZŠ podle shodných učebnicových materiálů. Nejprve jsou popsána teoretická východiska a stav řešení problematiky užívání učebnicových materiálů učiteli se zřetelem na transformaci netradičního učiva a na zavádění netradičních metodických postupů. V další části je prezentována metodologie výzkumu. Výzkumná data byla získána analýzou učebnicových materiálů, prostřednictvím rozhovorů s třemi učitelkami a pozorováním jejich výuky. Následující části jsou věnovány výsledkům výzkumu a diskusi. Zkoumané učitelky při plánování výuky vycházely z návrhu postupu v příručce pro učitele, přičemž hloubka jeho promýšlení u nich byla různá a projevila se ve výuce. Jedna návrhy rozvíjela, druhá je vesměs přejala, ale realizovala neefektivně. Třetí vybírala učivo i postupy, které preferuje. Zvláště u učiva, které je koncipováno nově či netradičně, hrozí nebezpečí horší orientace učitelů ve struktuře učiva, vzdělávacích cílech a návrzích na didaktické zpracování učiva. Pro některé mohou být učebnicové materiály zdrojem znalostí obsahu a didaktických znalostí obsahu, pro jiné jsou pouze zdrojem didaktických námětů, jejichž záměry si učitelé mohou vysvětlovat i v rozporu se záměrem autorů učebnicových materiálů. Porozumění problémům učitelů při zavádění inovací ve výuce je předpokladem uvažování o účinných formách jejich profesní podpory.
The Effectiveness of “Emolabeling” to Promote Healthy Food Choices in Children Preschool Through 5th Grade
Authors: Privitera Gregory J. , Phillips Taylor E. , Misenheimer Melissa , Paque Robert
Published: March 2014

Obesity has become a growing global concern. Evidence indicates that ecological factors are most predictive of obesity among children, and that a new strategy, referred to as emolabeling, may effectively address ecological factors, although the extent to which it can influence food choice is not yet known, but tested here. Specifically, we tested the hypothesis that children aged 3 to 11 years will use emolabels, or emotional correlates of health (i.e. healthy-happy, unhealthy-sad), to make healthy food choices. A cross-sectional design was used with two phases. In Phase 1, children were taught how to use emolabels with a “faces of health” lesson. In Phase 2, children made choices between containers that were laid out on a large table in pairs and varied by taste (tastes good, no information), social norms (popular, not popular), branding (image of a minion, no image), or preference (told what food was in each container). A control pair was labeled with only emoticons. The order and presentation of the containers were counterbalanced for each variation. Results showed that a significant proportion of children in the pre-literacy and the early literacy grades used emoticons to specifically make healthy food choices in each variation (p < .05 for all tests), except when children were told what foods were in the containers. In all, emolabeling effectively influenced food choices for healthy foods among children aged 3 to 11 years, more so than labeling for taste, social norms, and branding, but not preference.
Tout contre la télévision
Authors: Sermon Julie
Published: March 2014

Dans Vu d’ici, Mathieu Arsenault se livre à un violent réquisitoire contre
la télévision, dont il dénonce, à la suite d’un certain nombre d’intellectuels (Guy Debord,
Pier Paolo Pasolini, Noam Chomsky, Pierre Bourdieu…), les fonctionnements et les effets
idéologiques. Après s’être attaché aux réseaux métaphoriques que déploie l’auteur pour
alerter les consciences quant au fait que la télévision, symbole et vitrine de la société de
consommation, est aussi — voire surtout — l’étai du conformisme et de l’attentisme
politiques, cet article analyse la façon dont elle devient, aussi bien dans le texte que sur
scène, une forme de supra-identité venant infiltrer la voix et le corps du locuteur. À côté
des manières de voir qu’elle institue, la télévision engage aussi des manières de dire et de
faire, des énoncés et des gestes, que l’écriture poétique et scénique de Vu d’ici
s’attache à explorer et critiquer sur un mode tour à tour insidieux, offensif ou
parodique.
Claude Gauvreau et la critique théâtrale
Authors: Racine Noële
Published: March 2014

Cet article propose un examen (en trois temps) des rapports complexes s’établissant
entre les essais sur le théâtre, les chroniques dramatiques (1949-1970) et la dernière pièce
de Claude Gauvreau — liens qui, sauf erreur, n’ont pas encore fait l’objet d’une étude
approfondie. D’abord, on montrera que les références esthétiques et les prises de position
de l’auteur à l’égard du monde théâtral, dans sa prose journalistique, traduisent à la fois
un savoir critique et une (con)science poétique. Ensuite, on verra que cette science n’a
d’égale que la (pre)science d’une pratique scénique à venir, et ce, tant pour le théâtre
québécois que pour la dramaturgie gauvréenne. Enfin, il sera démontré que les conceptions
théâtrales du chroniqueur se transposent dans Les oranges sont vertes par
l’intermédiaire d’une représentation (incarnée) de la critique.
Establishing Sound
Authors: Altman Rick
Published: March 2014

The history of film sound has usually been configured as a series of technological
upheavals. In every case, the story has been told through technological innovations, as if
changes in technology were alone responsible for the development of new sound strategies.
The approach offered here differs markedly from these previous treatments of sound. Instead
of concentrating on technological shifts, this article stresses technical decisions made by
the soundmen and directors responsible for developing Hollywood’s standard approach to
sound. Through succinct analysis of two key films, The First
Auto (Warner, 1927) and It Happened One
Night (Columbia, 1934), along with briefer treatment of The Big Trail (Fox, 1930), a distinction is made between
“shot-by-shot” treatment of sound and “scene-by-scene” treatment of sound. The systematic
use of sound in It Happened One Night to establish
and maintain a coherent sense of place gives rise to recognition of the increasingly common
use of what the article terms “establishing sound.” Parallel to Hollywood’s familiar
technique of introducing each scene with an “establishing shot,” the use of establishing
sound offers filmmakers an additional method of locating auditors and maintaining their
relationship to the film.
Sound Synthesis, Representation and Narrative Cinema in the Transition to Sound
(1926-1935)
Authors: Corbella Maurizio , Windisch Anna Katharina
Published: March 2014

Since the beginnings of western media culture, sound synthesis has played a major role
in articulating cultural notions of the fantastic and the uncanny. As a counterpart to sound
reproduction, sound synthesis operated in the interstices of the original/copy
correspondence and prefigured the construction of a virtual reality through the generation
of novel sounds apparently lacking any equivalent with the acoustic world. Experiments on
synthetic sound crucially intersected cinema’s transition to synchronous sound in the late
1920s, thus configuring a particularly fertile scenario for the redefinition of narrative
paradigms and the establishment of conventions for sound film production. Sound synthesis
can thus be viewed as a structuring device of such film genres as horror and science
fiction, whose codification depended on the constitution of synchronized sound film. More
broadly, sound synthesis challenged the basic implications of realism based on the rendering
of speech and the construction of cinematic soundscapes.
Re-irradiation with Radiosurgery for Recurrent Glioblastoma Multiforme
Authors: Torok J. A. , Wegner R. E. , Mintz A. H. , Heron D. E. , Burton S. A.
Published: March 2014

Local tumor control remains a significant challenge in patients with glioblastoma multiforme (GBM). Despite aggressive radiation therapy approaches, most recurrences are within the high-dose field, limiting the ability to safely re-irradiate recurrence using conventional techniques. Fractionated stereotactic radiosurgery (fSRS) is a technique whose properties make it useful for re-irradiation. We retrospectively reviewed the charts of 14 patients with recurrent GBM treated with salvage radiosurgery. Seven patients were male and seven were female with a median age of 58 (range: 39–76). All patients had prior cranial radiation therapy to a median dose of 60 Gy (58–69). There were 18 lesions treated with a median tumor volume of 6.97 cm3 (0.54–50.0 cm3). fSRS was delivered in 1–3 fractions to a median dose of 24 Gy (18–30 Gy). Median follow-up for the cohort was 8 months (3–22 months). On follow-up MRI, 8 of 18 lesions had a radiographic response. The median time-to-progression following primary irradiation was 8 months (1-28 months) while the median time-to-progression (TTP) following fSRS was 5 months (1–16 months). Median local control following re-irradiation was 5 months and actuarial local control was 21% at 1-year. Overall survival following primary irradiation was 79% at 12 months and 46% at 2 years. Overall survival following re-irradiation was 79% at 6 months and 30% at 1 year. No significant treatment-related toxicity was seen in follow-up. These results indicate that re-irradiation for recurrent GBM using fSRS is well-tolerated and can offer a benefit in terms of progression-free survival (PFS).
Wave‐particle interactions during a dipolarization front event
Authors: Hwang K.‐J. , Goldstein M. L. , F.‐Viñas A. , Schriver D. , Ashour‐Abdalla M.
Published: March 2014

We present Cluster observations of wave‐particle interactions during an earthward propagating dipolarization front (DF) and associated fast plasma bulk flows detected at the central current sheet in Earth's magnetotail. During this period, flux tubes behind the DF frequently contain more energetic or hotter ions than did the preexisting flux tubes ahead of the DF. On the other hand, electrons within the DF flux tubes heat less, or are even colder, than were the preexisting populations and are often accompanied by superposed isolated beams. At the same time, electrostatic emissions are strongly enhanced over a wide range of frequencies (up to several times the electron cyclotron frequency) behind the DFs. This low‐frequency electrostatic wave power is well correlated with ion energization. From linear theory, we find two wave modes: a high‐frequency beam mode and a low‐frequency whistler mode that are associated with the electron beam component. We attribute the generation of whistlers to electron beams that persist for a while before undergoing rapid thermalization. The existence of isolated beam components behind DFs detected during the 4 s Cluster spin period indicates that DFs either provide a continuous source of electron beams or facilitate a physical process that maintains the beams against rapid thermalization. Our analysis suggests that the earthward motion of the DF flux tube, via Fermi acceleration as the magnetic field lines behind the DF shorten, can lead to the persistent electron beams that generate whistler mode waves, which in turn can heat ions. This scenario, by which free energy in electron beams generates waves that then heat ions, accounts for the Cluster observations of different energization behaviors between electrons and ions behind DFs.
Auroral ionospheric F region density cavity formation and evolution: MICA campaign results
Authors: Zettergren M. , Lynch K. , Hampton D. , Nicolls M. , Wright B. , Conde M. , Moen J. , Lessard M. , Miceli R. , Powell S.
Published: March 2014

Auroral ionospheric F region density depletions observed by PFISR (Poker Flat Incoherent Scatter Radar) during the MICA (Magnetosphere‐Ionosphere Coupling in the Alfvén Resonator) sounding rocket campaign are critically examined alongside complementary numerical simulations. Particular processes of interest include cavity formation due to intense frictional heating and Pedersen drifts, evolution in the presence of structured precipitation, and refilling due to impact ionization and downflows. Our analysis uses an ionospheric fluid model which solves conservation of mass, momentum, and energy equations for all major ionospheric species. These fluid equations are coupled to an electrostatic current continuity equation to self‐consistently describe auroral electric fields. Energetic electron precipitation inputs for the model are specified by inverting optical data, and electric field boundary conditions are obtained from direct PFISR measurements. Thus, the model is driven in as realistic a manner as possible. Both incoherent scatter radar (ISR) data and simulations indicate that the conversion of the F region plasma to molecular ions and subsequent recombination is the dominant process contributing to the formation of the observed cavities, all of which occur in conjunction with electric fields exceeding ∼90 mV/m. Furthermore, the cavities often persist several minutes past the point when the frictional heating stops. Impact ionization and field‐aligned plasma flows modulate the cavity depth in a significant way but are of secondary importance to the molecular generation process. Informal comparisons of the ISR density and temperature fits to the model verify that the simulations reproduce most of the observed cavity features to a reasonable level of detail.
High time and height resolution neutral wind profile measurements across the mesosphere/lower thermosphere region using the Arecibo incoherent scatter radar
Authors: Hysell D. L. , Larsen M. F. , Sulzer M. P.
Published: March 2014

A method for estimating the vector neutral wind profiles in the mesosphere and lower thermosphere (MALT) region of the upper atmosphere from Arecibo dual‐beam incoherent scatter radar data is presented. The method yields continuous estimates of both the altitude‐averaged F region plasma drifts and all three components of the altitude‐resolved neutral wind profiles in the MALT using data taken while the Arecibo feed system swings in azimuth. The problem is mixed determined, and its solution is not inherently unique. Second‐order Tikhonov regularization is used to find solutions consistent with the available data while being minimally structured, additional structure being unsupported by the data. The solution is found using the method of conjugate gradient least squares and sparse matrix mathematics. Example data acquired during an interval of midlatitude spread F are used to illustrate the method. The estimated wind profiles exhibit characteristics broadly consistent with gravity waves but are impulsive, with features that generally persist for less than one and a half wave periods.
Statistical characteristics of particle injections throughout the equatorial magnetotail
Authors: Gabrielse C. , Angelopoulos V. , Runov A. , Turner D. L.
Published: March 2014

Energetic particle injections are critical for supplying particles and energy to the inner magnetosphere. Recent case studies have demonstrated a good correlation between injections and transient, narrow, fast flow channels as well as earthward reconnection (dipolarization) fronts in the magnetotail, but statistical observations beyond geosynchronous orbit (GEO) to verify the findings were lacking. By surveying trans‐geosynchronous injections using Time History of Events and Macroscale Interactions during Substorms (THEMIS), we show that their likely origin is the earthward traveling, dipolarizing flux bundles following near‐Earth reconnection. The good correlation between injections and fast flows, reconnection fronts and impulsive, dawn‐dusk electric field increases is not limited to within 12 RE but extends out to 30 RE. Like near‐Earth reconnection, both ion and electron injections are most probable in the premidnight sector. Similar to bursty bulk flows (BBFs), injection‐time flow speeds are faster farther from Earth. With faster flows, injection intensity generally increases and extends to higher energy channels. With increased geomagnetic activity, injection occurrence rate increases (akin to that of BBFs) and spectral hardening occurs (κ decreases). The occurrence rate increase within the inner magnetosphere suggests that injections populate the radiation belts more effectively under enhanced activity. Our results are inconsistent with the classical concept of an azimuthally wide injection boundary moving earthward from ~9 to 12 RE to GEO under an enhanced cross‐tail electric field. Rather, particle injection and transport occur along a large range of radial distances due to effects from earthward penetrating, azimuthally localized, transient, strong electric fields of recently reconnected, dipolarizing flux bundles.
An efficient numerical method for earthquake cycles in heterogeneous media: Alternating subbasin and surface‐rupturing events on faults crossing a sedimentary basin
Authors: Erickson Brittany A. , Dunham Eric M.
Published: March 2014

We present an efficient numerical method for earthquake cycle simulations that employs a finite difference discretization of the off‐fault material to accommodate spatially variable elastic properties. The method is developed for the two‐dimensional antiplane shear problem of a vertical strike‐slip fault with rate‐and‐state friction. We compare earthquake cycles in a homogeneous half‐space with those in which the upper portion of the fault cuts through a sedimentary basin. In both cases, we assume velocity‐weakening behavior over the full seismogenic depth, even in the basin, to isolate the influence of elastic heterogeneity. In a homogeneous half‐space, events rupturing the full seismogenic depth occur periodically. Event sequences are more complex in basin models, with one or several subbasin events confined to the lower section of the fault followed by a much larger, surface‐rupturing event that breaks through the basin. This phenomenology emerges only for sufficiently compliant and deep basins. Predicted surface velocities are essentially identical before subbasin events and surface‐rupturing events, suggesting that geodetic observations would not be useful in predicting the rupture mode. The alternating sequence of subbasin and surface‐rupturing events would complicate interpretation of paleoseismic data. Our results also offer one potential explanation for the shallow slip deficit observed in many recent earthquakes, namely, that these events, which lack appreciable surface slip, are simply one style of rupture. Subsequent events on these faults might be larger, with slip extending all the way to the surface. The 1940 Mw 7.0 and 1979 Mw 6.5 Imperial Valley events might be considered as examples of these two rupture styles.
Potential of a low‐cost sensor network to understand the spatial and temporal dynamics of a mountain snow cover
Authors: Pohl Stefan , Garvelmann Jakob , Wawerla Jens , Weiler Markus
Published: March 2014

The spatial and temporal dynamics of seasonal snow covers play a critical role for many hydrological, ecological, and climatic processes. This paper presents a new, innovative approach to continuously monitor these dynamics using numerous low‐cost, standalone snow monitoring stations (SnoMoS). These stations provide snow and related meteorological data with a high temporal and spatial resolution. Data collected by SnoMoS include: snow depth, surface temperature, air temperature and humidity, total precipitation, global radiation, wind speed, and barometric pressure. A total of 99 sensors were placed over the winters 2010/2011 and 2011/2012 at multiple locations within three 40–180 km2 basins in the Black Forest region of Southern Germany. The locations were chosen to cover a wide range of slopes, elevations, and expositions in a stratified sampling design. Furthermore, “paired stations” located in close proximity to each other, one in the open and one underneath various forest canopies, were set up to investigate the influence of vegetation on snow dynamics. The results showed that considerable differences in snow depth and, therefore, snow water equivalent (SWE) are present within the study area despite its moderate temperatures and medium elevation range (400–1500 m). The relative impact of topographical factors like elevation, aspect, and of different types of forest vegetation were quantified continuously and were found to change considerably over the winter period. The recorded differences in SWE and snow cover duration were large enough that they should be considered in hydrologic and climate models.
Exploring the link between meteorological drought and streamflow: Effects of climate‐catchment interaction
Authors: Haslinger Klaus , Koffler Daniel , Schöner Wolfgang , Laaha Gregor
Published: March 2014

In this paper, we perform a detailed regional analysis of the link between meteorological drought indices and streamflow for a comprehensive Austrian data set of 47 small to medium‐size catchments in humid‐temperate climate. Four drought indices considering different components of the catchment water balance are tested. We assess the quality of the link using rank correlation analysis, and the probability of detecting low‐flow events by hit‐scores. Overall, correlations range between 0.4 and 0.8 and differ significantly between regions. A stratified analysis shows that the link is much stronger (i) for summer low flows and droughts than for anomalies in general, and (ii) for more humid than more arid conditions. Under more humid conditions streamflow droughts of small to medium‐size catchments are to a large extent generated by climate forcing and therefore well represented by a simple meteorological index. Under increasingly dry conditions, the climate signal gets less predictive, and storage properties of the underground become more important. A simple soil moisture accounting scheme (such as those of the Palmer index) can considerably improve the correlations. Overall, we conclude there is a significant link between meteorological drought and streamflow drought, except for catchments where groundwater storage and snow processes are important. The results are encouraging and provide a wealth of information which can profitably be used to set up statistical prediction models to estimate low flows from meteorological time series.
Copper(II)‐Catalyzed Aerobic Oxidative Coupling between Chalcone and 2‐Aminopyridine via CH Amination: An Expedient Synthesis of 3‐Aroylimidazo[1,2‐a]pyridines
Authors: Monir Kamarul , Kumar Bagdi Avik , Mishra Subhajit , Majee Adinath , Hajra Alakananda
Published: March 2014

A simple and efficient protocol has been developed for the synthesis of 3‐aroylimidazopyridines via copper(II) acetate‐catalyzed aerobic oxidative amination. A library of 3‐aroylimidazopyridines was synthesized from readily accessible chalcones and 2‐aminopyridines with high yields and regioselectivity. The reaction proceeds through a tandem Michael addition followed by an intramolecular oxidative amination. The successful application of this methodology for a gram‐scale reaction indicates its potential for bulk synthesis.

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Assembly of Indeno[1,2‐c]chromenes via a Palladium‐Catalyzed Reaction of 1‐Bromo‐2‐(cyclopropylidenemethyl)benzene with 2‐Alkynylphenol
Authors: Pan Xiaolin , Luo Yong , Ding Yechun , Fan Xiaona , Wu Jie
Published: March 2014

1‐Bromo‐2‐(cyclopropylidenemethyl)benzenes react with 2‐alkynylphenols under palladium catalysis, leading to indeno[1,2‐c]chromenes in moderate to good yields. The molecular complexity and diversity can be introduced efficiently from easily available starting materials.

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One‐Pot Synthesis of Spirooxazino Derivatives via Enzyme‐ Initiated Multicomponent Reactions
Authors: Wang Jun‐Liang , Chen Xiao‐Yang , Wu Qi , Lin Xian‐Fu
Published: March 2014

A novel enzyme‐initiated multicomponent reaction from readily available aldehyde, nitrostyrene, cyclohexanone and acetamide substrates was discovered, enabling the facile construction of six new CC/N bonds and two rings in single step, one‐pot operation, for the synthesis of spirooxazino derivatives in moderate to high yields. Several methods such as isotope labelling and enzyme mutation were used to probe the possible mechanism of this complex synthesis.

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Palladium‐Catalyzed Desulfitative Cross‐Coupling Reaction of Sodium Arylsulfinates with H‐Phosphonate Diesters
Authors: Miao Tao , Wang Lei
Published: March 2014

A novel and convenient palladium‐catalyzed cross‐coupling reaction of H‐phosphonate diesters with sodium arylsulfinates was developed via desulfitation in the presence of silver carbonate and tetra‐butylammonium chloride. This method is highly efficient and provides a rapid access to a broad spectrum of arylphosphonate diesters in good to excellent yields.

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Heck–Matsuda Arylation of Olefins Through a Bicatalytic Approach: Improved Procedures and Rationalization
Authors: Oger Nicolas , Le Callonnec François , Jacquemin Denis , Fouquet Eric , Le Grognec Erwan , Felpin François‐Xavier
Published: March 2014

The scope of the palladium‐catalyzed Heck–Matsuda reaction, proceeding through the catalytic activation of anilines into the corresponding diazonium salts, has been considerably extended and is now working with deactivated electrophiles. Two different procedures, using catalytic amounts of both palladium and acid, have been optimized allowing the concept of bicatalysis to cover the complete electronic range of anilines. These environmentally friendly procedures proceed under very mild conditions, at room temperature in methanol, and only generate tert‐butyl alcohol, water and nitrogen as by‐products. Rationalization of reaction outcomes encountered in this work has been discussed with the support of computational studies.

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The interaction effect between BDNF val66met polymorphism and obesity on executive functions and frontal structure
Authors: Marqués‐Iturria Idoia , Garolera Maite , Pueyo Roser , Segura Bàrbara , Hernan Imma , García‐García Isabel , Sánchez‐Garre Consuelo , Vernet‐Vernet María , Sender‐Palacios María José , Narberhaus Ana , Ariza Mar , Junqué Carme , Jurado María Ángeles
Published: March 2014

The prevalence of obesity is increasing worldwide. Previous research has shown a relationship between obesity and both executive functioning alterations and frontal cortex volume reductions. The Brain Derived Neurotrophic Factor val66met polymorphism, involved in eating behavior, has also been associated with executive functions and prefrontal cortex volume, but to date it has not been studied in relation to obesity. Our aim is to elucidate whether the interaction between the Brain Derived Neurotrophic Factor val66met polymorphism and obesity status influences executive performance and frontal‐subcortical brain structure. Sixty‐one volunteers, 34 obese and 27 controls, age range 12–40, participated in the study. Participants were assigned to one of two genotype groups (met allele carriers, n = 16, or non‐carriers, n = 45). Neuropsychological assessment comprised the Trail Making Test, the Stroop Test and the Wisconsin Card Sorting Test, all tasks that require response inhibition and cognitive flexibility. Subjects underwent magnetic resonance imaging in a Siemens TIM TRIO 3T scanner and images were analyzed using the FreeSurfer software. Analyses of covariance controlling for age and intelligence showed an effect of the obesity‐by‐genotype interaction on perseverative responses on the Wisconsin Card Sorting Test as well as on precentral and caudal middle frontal cortical thickness: obese met allele carriers showed more perseverations on the Wisconsin Card Sorting Test and lower frontal thickness than obese non‐carriers and controls. In conclusion, the Brain Derived Neurotrophic Factor may play an important role in executive functioning and frontal brain structure in obesity. © 2014 Wiley Periodicals, Inc.
Oxidative Coupling of Organoboron Compounds
Authors: Dhital Raghu Nath , Sakurai Hidehiro
Published: March 2014

An increasing number of boron‐mediated reactions have become leading synthetic tools in organic chemistry. The transition‐metal‐catalyzed oxidative coupling reactions of aryl‐ and alkylboron compounds have been intensively studied over recent decades. Palladium‐based catalysts are often used in the presence of an appropriate oxidant, and the reaction mechanism has been fully elucidated. Efficient homocoupling reactions that are catalyzed by nanosized (<2 nm) gold particles were introduced in 2004, which allow the use of oxygen as a sustainable oxidant. Besides palladium and gold, other transition metals and bimetallic combinations can also serve as excellent catalysts. This review summarizes both the seminal early work and recent developments in the area of transition‐metal‐catalyzed oxidative homocoupling reactions of organoboron compounds and discusses the mechanistic details.
Alkynes in Organocatalysis
Authors: Salvio Riccardo , Moliterno Mauro , Bella Marco
Published: March 2014

In this Focus Review, a selection of organocatalyzed reactions in which alkynes have been used are presented. Catalysis by tertiary and secondary amines, by phase‐transfer catalysis, by phosphines and carbenes, as well as bifunctional and multiple catalysis are discussed. Alkynes are versatile intermediates which can open novel synthetic opportunities as their reactivity is enhanced with respect to the corresponding alkenes and further elaboration to develop domino processes is possible.
A Redox Switchable Dihydrobenzo[b]pyrazine Push‐Pull System
Authors: Maniam Subashani , Higginbotham Heather F. , Guo Si‐Xuan , Bell Toby D. M. , Izgorodina Ekaterina I. , Langford Steven J.
Published: March 2014

The synthesis and spectroscopic properties of a dissymmetrically core‐extended naphthalene diimides derived from o‐phenylenediamine and cyanoethene dithiolate were explored. The push‐pull nature of the peripheral substituents allows these naphthalene diimide dyes and their progenitors to display interesting photophysical and electrochemical properties, with the target system acting as a highly reversible and quantitative molecular switch with clear absorption and emission readouts based on chemical oxidation and reduction processes.