bluuebunny/crossref_metadata_2025 huggingface dataset:
Precise outdoor localization with a GPS–INS integration system
Authors: Seo Wonkyo , Hwang Seoyoung , Park Jaehyun , Lee Jang-Myung
Published: July 2012

This paper proposes a precise outdoor localization algorithm with the integration of Global Positioning System (GPS) and Inertial Navigation System (INS). To achieve precise outdoor localization, two schemes are recently proposed, which consist of de-noising the INS signals and fusing the GPS and INS data. To reduce the noise from the internal INS sensors, the discrete wavelet transform and variable threshold method are utilized, and to fuse the GPS and INS data while filtering out the noise caused by the acceleration, deceleration, and unexpected slips, the Unscented Particle Filter (UPF) is adopted. Conventional de-noising methods mainly employ a combination of low-pass and high-pass filters, which results in signal distortion. This newly proposed system also utilizes the vibration information of the actuator according to the fluctuations of the velocity to minimize the signal distortion. The UPF resolves the nonlinearities of the actuator and non-normal distributions of the noise more effectively than the conventional particle filter (PF) or Extended Kalman Filter–PF. The superiority of the proposed algorithm was verified through experiments, and the results are reported.
The abundance and distribution of echinoderms in nearshore hard-bottom habitats near Anvers Island, western Antarctic Peninsula
Authors: White Brittny A. , McClintock James , Amsler Charles D. , Mah Christopher L. , Amsler Margaret O. , White Stephanie , Quetin Langdon B. , Ross Robin M.
Published: July 2012

Echinoderms are well represented in nearshore hard-bottom (< 100 m depth) habitats along the Antarctic Peninsula where they are presumably important contributors to benthic production, carbon flow, and determinants of community structure. The present study assesses the densities of echinoderms at shallow depths (2–15 m) at five sampling sites within three kilometres of Anvers Island on the central western Antarctic Peninsula. The asteroids Odontaster validus, Granaster nutrix, Lysasterias perrieri and Adelasterias papillosa, two ophiuroids in the Amphiuridae, the holothuroids Psolicrux coatsi and Psolus carolineae and one representative of the Cucumaridae, and the regular echinoid Sterechinus neumayeri were enumerated. Mean total echinoderm densities were high (34.9 individuals m-2) and ranged from 21.9 individuals m-2 for asteroids to 2.7 individuals m-2 for holothuroids. With the exception of a positive relationship between the abundance of the regular echinoid Sterechinus neumayeri and the biomass of the brown alga Himanthothallus grandifolius, no significant relationships were found between the abundance of asteroids, ophiuroids, or holothuroids and two species of brown algae or three algal ecotypes. The present study indicates nearshore hard-bottom echinoderms are important in the carbon cycle and their inherent vulnerability to ocean acidification may have community-level impacts.
Breaking physical dormancy of Cassia leptophylla and Senna macranthera (Fabaceae: Caesalpinioideae) seeds: water absorption and alternating temperatures
Authors: de Paula Alexandre Souza , Delgado Carolina Maria Luzia , Paulilo Maria Terezinha Silveira , Santos Marisa
Published: July 2012

This study analysed the anatomical structure of the seed coats, identified the location of water uptake and evaluated the effects of alternating temperatures and heat treatment on the breaking of physical dormancy of two species of Fabaceae (Caesalpinioideae), Cassia leptophylla and Senna macranthera, from the Atlantic forest of Brazil. The seed coats of both species consisted of a cuticle (extra-hilar region) or remaining funicle region (hilar region), subcuticular layer, palisade layer with lignin, osteosclereids, sclerified parenchyma and white cells. The palisade layer was formed by elongated macrosclereids with a light line of callose. In thermally scarified seeds of C. leptophylla, water entered through the micropylar canal, and in S. macranthera the water entered through the lens. Alternating temperatures that ranged from 15 to 30°C did not break physical dormancy of either species; however, exposure to 50°C broke seed hardcoatedness, allowing the entrance of water in both species.
In the Line of Duty: A Study of Ambulance Drivers During the 2010 Conflict in Kashmir
Authors: Dhar Shabir Ahmed , Dar Tahir Ahmed , Wani Sharief Ahmed , Hussain Shahid , Dar Reyaz Ahmed , Wani Zaid Ahmed , Aazad Shah , Yaqoob Suhail , Mansoor Imtiyaz , Ali Murtaza Fazal , Ahmed Muzaffar , Mumtaz Imran , Azhar Idrees
Published: July 2012

Purpose

The purpose of this study was to identify the problems faced by ambulance drivers working in a conflict zone.

Methods

This study was conducted on ambulance drivers working for the four major hospitals in Kashmir, India. The drivers were interviewed and asked a series of 30 work-related questions. The individual interviews were conducted over a three-month period in the valley of Kashmir that was affected by continuous violence, strict curfew, and strikes.

Results

A total of 35 ambulance drivers were interviewed. Drivers worked an average of 60 h/wk, and they drove an average of 160 km/d. Twenty-nine (83%) of the drivers experienced >1 threat of physical harm; 18 (54%) experienced physical assaults; and 31 (89%) reported evidence of psychological morbidity associated with their jobs.

Conclusions

The atmosphere of conflict on the streets of Kashmir impacted the ambulance drivers adversely, both physically as well as mentally. The stress faced by these professionals in conflict zones during their duty hours should be recognized, and corrective measures must be put in place.

Dhar SA, Dar TA, Wani SA, Hussain S, Wani ZA, Aazad S, Yaqoob S, Mansoor I, Ali MF, Ahmed M, Mumtaz I, Azhar I. In the line of duty: a study of ambulance drivers during the 2010 conflict in Kashmir.Prehosp Disaster Med.2012;27(4):1-4.
From systems chemistry to systems astrobiology: life in the universe as an emergent phenomenon
Authors: Chela-Flores J.
Published: July 2012

Although astrobiology is a science midway between the life and physical sciences, it has surprisingly remained largely disconnected from recent trends in certain branches of both life and physical sciences. We discuss potential applications to astrobiology of approaches that aim at integrating rather than reducing. Aiming at discovering how systems properties emerge has proved valuable in chemistry and in biology. The systems approach should also yield insights into astrobiology, especially concerning the ongoing search for alternative abodes for life. This is feasible since new data banks in the case of astrobiology – considered as a branch of biology – are of a geophysical/astronomical kind, rather than the molecular biology data that are used for questions related firstly, to genetics in a systems context and secondly, to biochemistry for solving fundamental problems, such as protein or proteome folding. By focusing on how systems properties emerge in astrobiology we consider the question: can life in the universe be interpreted as an emergent phenomenon? In the search for potential habitable worlds in our galactic sector with current space missions, extensive data banks of geophysical parameters of exoplanets are rapidly emerging. We suggest that it is timely to consider life in the universe as an emergent phenomenon that can be approached with methods beyond the science of chemical evolution – the backbone of previous research in questions related to the origin of life. The application of systems biology to incorporate the emergence of life in the universe is illustrated with a diagram for the familiar case of our own planetary system, where three Earth-like planets are within the habitable zone (HZ) of a G2 V (the complete terminology for the Sun in the Morgan–Keenan system) star. We underline the advantage of plotting the age of Earth-like planets against large atmospheric fraction of a biogenic gas, whenever such anomalous atmospheres are discovered in these worlds. A prediction is made as to the nature of the atmospheres of the planets that lie in the stellar HZs.
Leistungsbeurteilungen von Schulkindern
Authors: Krolak-Schwerdt Sabine , Böhmer Matthias , Gräsel Cornelia
Published: July 2012

Zusammenfassung. Es wurde untersucht, inwieweit unterschiedliche Ziele bei der Verarbeitung von Informationen über einen Schüler (z.B. Ergebnis in Mathematikvergleichsarbeit) sowohl die Leistungsbeurteilung als auch Schlussfolgerungen über Verhalten und Leistungsvermögen des Schülers beeinflussen. Lehrkräfte als Expertinnen und Experten sowie Studierende der Naturwissenschaften als Laien erhielten eine Falldarstellung eines Schülers unter der Zielvorgabe, sich entweder einen Eindruck über seine Persönlichkeit und sein Leistungsvermögen zu bilden (Eindrucksbildungsziel) oder seine weitere Entwicklung vorherzusagen (Vorhersageziel). Anschließend waren die Falldarstellung mit eigenen Worten zusammenzufassen und das Leistungsvermögen des beschriebenen Schülers zu beurteilen. Expertinnen und Experten orientierten sich unter dem Vorhersageziel an den individuellen Schülermerkmalen, unter dem Ziel der Eindrucksbildung verwendeten sie eine vorgegebene soziale Kategorie. Bei Laien hingegen hatte das Ziel keinen Einfluss auf die Verarbeitung der Schülermerkmale.
Die Anfänge geschlechtsspezifischer Leistungsunterschiede in mathematischen und schriftsprachlichen Kompetenzen
Authors: Niklas Frank , Schneider Wolfgang
Published: July 2012

Zusammenfassung. Geschlechtsspezifische Leistungsunterschiede in mathematischen und schriftsprachlichen Kompetenzen sind ein viel diskutiertes Thema. Trotz umfangreicher Analysen herrscht nach wie vor Unklarheit darüber, zu welchem Zeitpunkt Leistungsunterschiede in spezifischen kognitiven Fähigkeiten auftreten und welche Ursachen hierfür verantwortlich sind. In der vorliegenden Längsschnittstudie wurde deshalb die mathematische und schriftsprachliche Kompetenz- und Selbstkonzeptentwicklung von über 900 Kindern im Verlauf der letzten anderthalb Vorschuljahre sowie in der 1. Klasse verfolgt. Es zeigten sich keine Geschlechtsunterschiede in einer Reihe von Kontrollvariablen. Auch in den schriftsprachlichen und mathematischen Vorläuferfertigkeiten fanden sich keine signifikanten Unterschiede. Hingegen konnten signifikante und bedeutsame Leistungs- und Selbstkonzeptunterschiede in der 1. Klasse festgestellt werden. So wiesen Jungen in der 1. Klasse bessere mathematische Leistungen und ein höheres mathematisches Selbstkonzept auf, und Mädchen erbrachten passend zu ihrer hier höheren Selbsteinschätzung bessere Leistungen im Lesen und Rechtschreiben. Die Kompetenzentwicklung wurde in zwei Strukturgleichungsmodellen abgebildet, die auch den Einfluss des Geschlechts und der fachspezifischen Selbstkonzepte verdeutlichen.
Differenzielle Benotungen von Mädchen und Jungen
Authors: Kuhl Poldi , Hannover Bettina
Published: July 2012

Zusammenfassung. Wir gehen der Frage nach, inwiefern Geschlechtsunterschiede in Noten darauf zurückgeführt werden können, dass Lehrkräfte bei Jungen eine geringere Selbststeuerung im Lernen wahrnehmen als bei Mädchen. Bei 1533 Mädchen und Jungen aus 78 vierten Grundschulklassen wurden Halbjahresnoten für Deutsch und Mathematik, standardisierte Testleistungen im Lesen und in Mathematik sowie Einschätzungen der Selbststeuerung im Lernen durch die Klassenlehrkraft erhoben. In Deutsch konnten die besseren Noten, die Mädchen auch nach Kontrolle ihrer Lesekompetenz-Testleistungen hatten, teilweise durch die stärkere von der Lehrkraft wahrgenommene Selbststeuerung im Lernen erklärt werden. Für Mathematik waren die Ergebnisse weniger klar interpretierbar. Nach Kontrolle des Einflusses der Testleistungen ergab sich keine Ungleichbenotung der Geschlechter. Wurden jedoch zusätzlich die Einschätzungen der Lehrkräfte zur Selbststeuerungsfähigkeit ihrer Schülerinnen und Schüler herauspartialisiert, so wurden Jungen in Mathematik relativ besser bewertet als Mädchen. Wir diskutieren, inwiefern diese Befunde auf tatsächliche Geschlechtsunterschiede in der Selbstregulationsfähigkeit oder aber auch auf Geschlechtsstereotype der Lehrkräfte zurückgehen.
Reliability and Validity of the German Version of the Young Schema Questionnaire – Short Form 3 (YSQ-S3)
Authors: Kriston Levente , Schäfer Janina , Jacob Gitta A. , Härter Martin , Hölzel Lars P.
Published: July 2012

To date, the psychometric properties of the German version of the Young Schema Questionnaire – Short Form 3 (YSQ-S3) have not yet been examined. We investigated the reliability and validity of the German version of the YSQ-S3. In a community sample of 1,150 participants and a clinical sample of 30 psychiatric inpatients, we performed reliability analysis, confirmatory factor analysis, and correlation analyses, and tested for group differences using analysis of variance. The YSQ-S3 proved to be reliable and corresponded to the theoretically proposed 18-dimensional structure. Schema scores were positively associated with measures of psychopathology and personality disorder, indicating convergent validity. Furthermore, the YSQ-S3 differentiated between participant subgroups defined by level of health-care utilization, supporting discriminant validity. We conclude that the YSQ-S3 is a psychometrically sound instrument that can be used in German-speaking countries in research on early maladaptive schemas. Further research is necessary particularly in larger clinical samples.
A Spanish Adaptation of the Emotion Regulation Questionnaire
Authors: Cabello Rosario , Salguero José M. , Fernández-Berrocal Pablo , Gross James J.
Published: July 2012

The Emotion Regulation Questionnaire (ERQ; Gross & John, 2003 ) is widely used to assess individual differences in reappraisal and suppression. The present study tests the psychometric properties, reliability, and validity of a Spanish adaptation of the ERQ on a broad sample of participants of Spanish nationality aged 18–80 years (38% males, 62% females). Results of the confirmatory factor analysis showed the expected two-factor structure. Results also indicated adequate internal consistency, test-retest reliability, and convergent and discriminant validity. In terms of affective functioning, reappraisal use was positively associated with positive emotion, whereas suppression use was negatively associated with positive emotion. In terms of social functioning, reappraisal use was positively associated with social functioning, whereas suppression use was negatively associated with social functioning. These findings suggest that the Spanish version of the ERQ is a valid instrument for evaluating strategies of emotion regulation in the Spanish-speaking population, and can be used for laboratory and applied studies.
Self-Efficacy in Regulating Positive and Negative Emotions
Authors: Gunzenhauser Catherine , Heikamp Tobias , Gerbino Maria , Alessandri Guido , von Suchodoletz Antje , Di Giunta Laura , Caprara Gian Vittorio , Trommsdorff Gisela
Published: July 2012

Perceived self-efficacy in emotion regulation facilitates various aspects of psychosocial adjustment. The Regulatory Emotional Self-Efficacy scale (RESE) by Caprara and Gerbino (2001) measures perceived capabilities to express positive emotions (POS) and to manage negative emotions, namely, despondency/distress (DES) and anger/irritation (ANG). The present research investigated the validity of the RESE scale in Germany. Study 1 investigated the factor structure and convergent validity of the scale in a sample of university students. In order to test the generalizability of findings from Study 1, in Study 2 we studied the factor structure, cross-gender invariance, and convergent validity of a slightly revised version of the scale in a sample of parents. The previously found factor structure was successfully replicated in both samples. Partial invariance on the scalar level was confirmed across gender. All self-efficacy subscales were positively correlated with life satisfaction and with reappraisal (a cognitive emotion regulation strategy). Suppression, a strategy of regulating emotional expression, was negatively related to POS. Findings suggest that the RESE scale is a valid instrument to assess emotion regulation self-efficacy in German-speaking samples.
Psychometric Properties of the Romanian Version of the Zuckerman-Kuhlman Personality Questionnaire
Authors: Sârbescu Paul , Neguţ Alexandra
Published: July 2012

This research investigated the psychometric properties and the convergent and divergent validity of the Romanian version of the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ) at the factor-level. The ZKPQ assesses the five basic factors of Zuckerman’s alternative five-factor model (AFFM). Study 1 (n = 449) assessed the psychometric properties of the Romanian version of the ZKPQ and verified its factorial structure. The factors reliability ranged from .69 to .88, and gender differences were similar to those found in the Spanish, French, and Chinese samples. Exploratory factor analysis supported the replicability of the original five-factor structure, and correlations between the scales showed that the five basic factors of the AFFM are relatively independent. Study 2 (n = 238) verified the convergent and divergent validity of the Romanian version of the ZKPQ, by testing its links with DECAS, a personality inventory based on the five-factor model, developed and well-validated on the Romanian population. The results showed good convergent and divergent validity, with all identified correlations supporting the correspondence between the two personality models. Overall, the present findings showed that the Romanian version of the ZKPQ is a valid tool for assessing personality traits according to the AFFM.
When Does Self-Promotion Work?
Authors: Proost Karin , Germeys Filip , Schreurs Bert
Published: July 2012

Based on temporal construal theory, this study examined how temporal distance (i.e., hiring someone for the near vs. distant future) influences the effectiveness of different types of self-promotion, applied by a fictive applicant in a personnel selection interview. Findings of two experiments were in line with our predictions that promoting oneself in a direct way (i.e., referring to one’s own achievements) or in concrete terms (i.e., focusing on situation-specific behaviors) is more successful when applying for immediate entry whereas promoting oneself in an indirect way (i.e., emphasizing connections with others) or in abstract terms (i.e., focusing on traits) is more successful when applying for a vacancy to be filled in the distant future.
Dual Goals for Speed and Accuracy on the Same Performance Task
Authors: Wetter Olive Emil , Wegge Jürgen , Jonas Klaus , Schmidt Klaus-Helmut
Published: July 2012

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.
GPS meteorology: An investigation of ocean‐based precipitable water estimates
Authors: Kealy John , Foster James , Businger Steven
Published: July 2012

A study of ship‐based precipitable water (PW) estimation using the global positioning system (GPS) is presented for a field experiment in the coastal waters of Hawai‘i. GPS precipitable water estimates, with a temporal resolution of 30 min, are shown to agree with radiosonde observations with an RMS error of 2.16 mm. The GPS PW time series is shown to possess significant value in identifying atmospheric features at both synoptic and mesoscale resolution throughout the experiment. Examples include influences from an upper level low‐pressure system, shear lines, island blocking, and zones of low level convergence. Given PW's high spatial and temporal variability and the fact that it is not dynamically tied to other variables such as pressure or temperature, future PW estimates from ships could provide an important constraint for numerical weather prediction (NWP) models over ocean regions.
Rhenium in Indian rivers: Sources, fluxes, and contribution to oceanic budget
Authors: Rahaman Waliur , Singh Sunil Kumar , Shukla Anil Dutt
Published: July 2012

The abundance and distribution of dissolved and particulate Rhenium (Re) has been measured in several rivers draining the Himalaya and Peninsular India, from their origin to outflow into the Bay of Bengal and the Arabian Sea. The large data set resulting from this study on rivers flowing through a variety of lithologies e.g., the crystallines and sediments of the Himalaya, Deccan basalts, Vindhyan sediments and the Indian shield significantly enhances our understanding of the aqueous geochemistry of Re and also constrains its sources to rivers and fluxes to the sea. The concentration of dissolved Re in rivers of the Himalaya and the Peninsular India shows wide range; 1.4 to 72.7 pmol/kg (mean 7.8 pmol/kg) and 0.5 to 122 pmol/kg (mean 15 pmol/kg) respectively. The discharge weighted average annual flux of dissolved Re transported by the rivers from these regions are ∼5800 and ∼15,700 mol/year respectively. The major source of dissolved Re, as determined from inter‐element associations, is black shales for the Himalayan rivers and pyrites in basalts for the east flowing Deccan rivers. In addition, there are evidences of considerable anthropogenic supply of Re to some of the rivers that have very high Re concentrations. Estimates of anthropogenic supply based on their Re/K ratios suggest that this source accounts for most of the Re in the Peninsular rivers, particularly the Godavari. The annual flux of anthropogenic Re transported by the Peninsular rivers is ∼14,600 mol, most of which is from the Godavari. This anthropogenic flux accounts for ∼70% of the total Re supply by the Indian rivers to the adjacent seas and 3.4% of the global riverine flux to the oceans. The global average, pre‐anthropogenic (natural) concentration of dissolved Re in rivers is estimated to be ∼3 pmol/kg based on Re−K correlation. This value is much lower than the contemporary average determined from the measured concentrations and earlier estimate of natural Re based on Re−SO4 link.
Variety and origin of magmas on Shatsky Rise, northwest Pacific Ocean
Authors: Sano Takashi , Shimizu Kenji , Ishikawa Akira , Senda Ryoko , Chang Qing , Kimura Jun‐Ichi , Widdowson Mike , Sager William W.
Published: July 2012

Shatsky Rise consists of thick (∼30 km maximum) basaltic crust with various geochemical compositions. Geochemistry data indicate that four magma types exist on the plateau; namely normal, low‐Ti, high‐Nb, and U1349 types. The normal type is the most abundant in volume and appears on all three large edifices of the plateau: Tamu, Ori, and Shirshov massifs. Composition of the normal type is similar to normal mid‐ocean ridge basalt (N‐MORB) composition, but with slight relative enrichment of the more incompatible elements. The low‐Ti type is distinguished from the normal type basalt by slightly lower Ti content at a given MgO. Composition of the high‐Nb type is characterized by distinctively high contents of incompatible trace elements. U1349 type basalts are composed of more primitive and depleted compositions compared with the others. The normal type basalts constitute ∼94% of the lava units of the oldest Tamu Massif and non‐normal types (i.e., the other three types) basalts comprise ∼57% on the younger Ori Massif, implying that geochemical compositions may have become heterogeneous with time. Petrological examination demonstrates that compositions of the normal‐, low‐Ti‐, and high‐Nb‐type basalts evolved through fractional crystallization of olivine, plagioclase, and augite in shallow magma chambers (<200 MPa). Model calculations of immobile trace elements estimate that the normal type basalt can be formed by ∼15% melting of a depleted mantle source in the presence of residual garnet. This degree of melting is similar to N‐MORB, but the larger effect of residual garnet during petrogenesis implies that a greater depth of melting.
Improving on mass flow rate estimates of volcanic eruptions
Authors: Degruyter W. , Bonadonna C.
Published: July 2012

We introduce a novel analytical expression that allows for fast assessment of mass flow rate of both vertically‐rising and bent‐over volcanic plumes as a function of their height, while first order physical insight is maintained. This relationship is compared with a one‐dimensional plume model to demonstrate its flexibility and then validated with observations of the 1980 Mount St. Helens and of the 2010 Eyjafjallajökull eruptions. The influence of wind on the dynamics of volcanic plumes is quantified by a new dimensionless parameter (Π) and it is shown how even vertically‐rising plumes, such as the one associated with the Mount St. Helens 1980 eruption, can be significantly affected by strong wind. Comparison between a one‐dimensional model and the analytical equation gives anR2‐value of 0.88, while existing expressions give negativeR2‐values due to their inability to adapt to different source and atmospheric conditions. Therefore, this new expression has important implications both for current strategies of real‐time forecasting of ash transport in the atmosphere and for the characterization of explosive eruptions based on the study of tephra deposits. In addition, this work provides a framework for the application of more complete three‐dimensional numerical models as it greatly reduces the parameter space that needs to be explored.
Strong longitudinal difference in ionospheric responses over Fortaleza (Brazil) and Jicamarca (Peru) during the January 2005 magnetic storm, dominated by northward IMF
Authors: Santos A. M. , Abdu M. A. , Sobral J. H. A. , Koga D. , Nogueira P. A. B. , Candido C. M. N.
Published: July 2012

In this study we investigate the response of the equatorial F layer to disturbance zonal electric field associated with IMF (interplanetary magnetic field) variations dominated by a strong northward Bz episode during the magnetic storm that occurred on 21 January, 2005. We compared the results obtained from Digisondes operated at Fortaleza, Brazil (Geogr. 3.9°S, 38.45°W; dip angle: −11.7°) and Jicamarca, Peru (Geogr. 12.0°S, 76.8°W; dip angle: 0.64°). A large auroral activity (AE) intensification that occurred at ∼1715 UT produced a large F‐layer peak height increase (from 300 km to 600 km) over Jicamarca with no noticeable simultaneous effect over Fortaleza. Then the Bz turning northward at ∼1940 UT with a rapid change in AE that was accompanied by a large decrease of F layer height and total suppression of the PRE over Fortaleza with no simultaneous effect over Jicamarca. Strong increase in the AE index (from ∼400 to 1000 nT) with superimposed oscillations, under Bz North, that soon followed was associated with increases in both the F layer height and the vertical drift velocity over Fortaleza (at 2130 UT), with no corresponding signatures over Jicamarca. These remarkable contrasting responses to prompt penetration electric field (PPEF) as well as to disturbance wind dynamo electric field (DDEF) and other effects observed at the two locations separated only by 2 h in LT in the South American sector are presented and discussed in this paper. Effects onspread‐F development and foF2 behavior during this storm event are also addressed in this work.
Dayside magnetic topology at the Earth's magnetopause for northward IMF
Authors: Fuselier S. A. , Trattner K. J. , Petrinec S. M. , Lavraud B.
Published: July 2012

When the Interplanetary Magnetic Field is northward, magnetic reconnection occurs at the Earth's high latitude magnetopause in regions poleward of the Earth's magnetospheric cusps. Observations at the high latitude magnetopause appear to support reconnection poleward of both northern and southern hemisphere cusps, forming closed field lines in the magnetosheath. However, observations at the dayside low latitude magnetopause and in the low altitude cusp do not support this reconnection scenario. Using plasma and magnetic field data from the Cluster spacecraft, signatures of reconnection poleward of both cusps were investigated as a function of latitude. It was found that reconnection in at least one hemisphere occurs essentially all the time for northward IMF. This investigation also confirmed the apparent discrepancy between high and low latitude observations. A scenario for reconnection in both cusps whereby the field line reconnected poleward of one cusp convects away from the dayside magnetopause before reconnecting in the opposite hemisphere is consistent with observations at all latitudes.
The 2010–2011 Canterbury, New Zealand, seismic sequence: Multiple source analysis from InSAR data and modeling
Authors: Atzori S. , Tolomei C. , Antonioli A. , Merryman Boncori J. P. , Bannister S. , Trasatti E. , Pasquali P. , Salvi S.
Published: July 2012

The 2010–2011 Canterbury sequence is a complex system of seismic events that started with a Mw7.1 earthquake and continued with large aftershocks with dramatic consequences, particularly for the city of Christchurch. We model the main earthquakes using InSAR data, providing displacement maps and the respective modeling for the September 4th, 2010, February 22nd, 2011 and June 13th, 2011 events. Relocated aftershocks, field and GPS surveys are used to constrain models obtained by inversion of InSAR data; the fault slip distribution is retrieved with a variable patch size approach aimed at maximizing the spatial resolution on the fault plane. For the September 2010 earthquake we estimated significant slip values below 10 km depth; the calamitous February 2011 event in Christchurch is modeled with a double fault source with slip values less than 2 m down to 7 km depth; for the second June 13th event in Christchurch we identified a NW‐SE striking fault as responsible for the earthquake. Last, we introduce the use of InSAR coherence maps to quickly detect the areas subject to soil liquefaction in Christchurch, as shown for the two main events.
Impact ionization mass spectra of anorthite cosmic dust analogue particles
Authors: Hillier J. K. , Postberg F. , Sestak S. , Srama R. , Kempf S. , Trieloff M. , Sternovsky Z. , Green S. F.
Published: July 2012

Anorthite, the Ca‐rich end‐member of plagioclase feldspar, is a dominant mineral component of the Lunar highlands. Plagioclase feldspar is also found in comets, meteorites and stony asteroids. It is therefore expected to contribute to the population of interplanetary (and circumplanetary) dust grains within the solar system. After coating micron‐ and submicron‐sized grains of Anorthite with a conductive layer of Platinum, the mineral was successfully accelerated to hypervelocity speeds in the Max Planck Institut für Kernphysik's Van de Graaff accelerator. We present impact ionization mass spectra generated following the impacts of anorthite grains with a prototype mass spectrometer (the Large Area Mass Analyser, LAMA) designed for use in space, and discuss the behavior of the spectra with increasing impact energy. Correlation analysis is used to identify the compositions and sources of cations present in the spectra, enabling the identification of several molecular cations (e.g., CaAlO2, CaSiO2, Ca2AlO3/CaAlSi2O2) which identify anorthite as the progenitor bulk grain material.
A probabilistic description of the bed load sediment flux: 4. Fickian diffusion at low transport rates
Authors: Furbish David Jon , Ball Ashley E. , Schmeeckle Mark W.
Published: July 2012

High‐speed imaging of coarse sand particles transported as bed load reveals how particle motions possess intrinsic periodicities associated with their start‐and‐stop behavior. The dominant harmonics in these motions have a primary influence on the rate at which the mean squared particle displacementR(τ) — a measure conventionally used to assess the possibility of anomalous diffusion — increases with the time interval τ. Over a timescale corresponding to the typical travel time of particles, calculations of R(τ) may ostensibly indicate non‐Fickian behavior while actually reflecting the effects of periodicities in particle motions, not anomalous diffusion. We provide the theoretical basis for this observed behavior, and we illustrate how the effective (Fickian) particle diffusivity obtains from G. I. Taylor's classic definition involving the particle velocity autocovariance, including its relation to the ensemble‐averaged particle velocity as articulated by O. M. Phillips. Cross‐stream diffusivities are an order of magnitude smaller than streamwise diffusivities.
Bayesian evaluation of groundwater age distribution using radioactive tracers and anthropogenic chemicals
Authors: Massoudieh Arash , Sharifi Soroosh , Solomon D. Kip
Published: July 2012

The development of a Bayesian modeling approach for estimation of the age distribution of groundwater using radioactive isotopes and anthropogenic chemicals is described. The model considers the uncertainties associated with the measured tracer concentrations as well as the parameters affecting the concentration of tracers in the groundwater, and it provides the posterior probability densities of the parameters defining the groundwater age distribution using a Markov chain Monte Carlo method. The model also incorporates the effect of dissolution of aquifer minerals on diluting the14C signature and the uncertainties associated with this process on the inferred age distribution parameters. Two demonstration modeling cases have been performed. First, the method was applied to simulated tracer concentrations at a discharge point of a hypothetical 2‐D vertical aquifer with two recharge zones, leading to a mixed groundwater age distribution under different presumed uncertainties. When the error variance of the observed tracer concentrations is considered unknown, the method can estimate the parameters of the fitted exponential‐lognormal distribution with a relatively narrow credible interval when five hypothetical samples are assumed to be collected at the discharge point. However, when a single sample is assumed, the credible intervals become wider, and credible estimations of the parameters are not obtained. Second, the method was applied to the data collected at La Selva Biological Station in Costa Rica. In this demonstration application, nine different forms of presumed groundwater age distributions have been considered, including four single forms and five mixed forms, assuming the groundwater consists of distinct young and old fractions. For the medium geometrical standard deviationδc,i = 1.41, the model estimates a young groundwater age of between 0 and 350 years, with the largest odds being given to a mean age of approximately 100 years, and a fraction of young groundwater of between 15% to roughly 60%, with the largest odds for 30%. However, the method cannot definitively rule out larger fractions of young groundwater. The model provides a much more uncertain estimation of the age of old groundwater, with a credible interval of between 20,000 to 200,000 years.
A generalized approach for estimation of in‐plane curvature in invasion percolation models for drainage in fractures
Authors: Yang Zhibing , Niemi Auli , Fagerlund Fritjof , Illangasekare Tissa
Published: July 2012

In‐plane interfacial curvature plays an important role in shaping the phase structure during quasi‐static immiscible displacement in horizontal rough‐walled fractures. Existing approaches used in percolation modeling require the use of a predefined globally representative length scale for calculating the in‐plane curvature. This length scale is typically estimated using the geostatistics of fracture aperture variability. However, there has not been any rigorous and general derivation on how to obtain this length scale in the literature. This paper presents a general method referred to as adaptive circle‐fitting (ACF) approach to estimate in‐plane curvature, recognizing that in some fractures the in‐plane curvature along the fluid‐fluid interface may exhibit various length scales due to the variability both in the locally averaged aperture and in the fracture wall roughness. The ACF involves nonlinear fitting of the interface to an osculating circle whose radius geometrically defines the inverse of the local curvature. This approach does not require predefining an empirical representative length scale. The influence length of the interface to which the circle is fitted is determined adaptively based on an acceptable threshold error. We have implemented the ACF approach to an invasion percolation model and have performed numerical simulations against experimental data on drainage processes in two horizontal rough‐walled fractures. The observed invasion phase structures can be well reproduced using this generalized approach. In comparison to the previous approaches, it also demonstrates better performance in matching the experimental results of invasion phase distributions and fractal dimensions of the invasion clusters.
Metaproteogenomic insights beyond bacterial response to naphthalene exposure and bio-stimulation
Authors: Guazzaroni María-Eugenia , Herbst Florian-Alexander , Lores Iván , Tamames Javier , Peláez Ana Isabel , López-Cortés Nieves , Alcaide María , Del Pozo Mercedes V , Vieites José María , von Bergen Martin , Gallego José Luis R , Bargiela Rafael , López-López Arantxa , Pieper Dietmar H , Rosselló-Móra Ramón , Sánchez Jesús , Seifert Jana , Ferrer Manuel
Published: July 2012

Microbial metabolism in aromatic-contaminated environments has important ecological implications, and obtaining a complete understanding of this process remains a relevant goal. To understand the roles of biodiversity and aromatic-mediated genetic and metabolic rearrangements, we conducted ‘OMIC’ investigations in an anthropogenically influenced and polyaromatic hydrocarbon (PAH)-contaminated soil with (Nbs) or without (N) bio-stimulation with calcium ammonia nitrate, NH4NO3 and KH2PO4 and the commercial surfactant Iveysol, plus two naphthalene-enriched communities derived from both soils (CN2 and CN1, respectively). Using a metagenomic approach, a total of 52, 53, 14 and 12 distinct species (according to operational phylogenetic units (OPU) in our work equivalent to taxonomic species) were identified in the N, Nbs, CN1 and CN2 communities, respectively. Approximately 10 out of 95 distinct species and 238 out of 3293 clusters of orthologous groups (COGs) protein families identified were clearly stimulated under the assayed conditions, whereas only two species and 1465 COGs conformed to the common set in all of the mesocosms. Results indicated distinct biodegradation capabilities for the utilisation of potential growth-supporting aromatics, which results in bio-stimulated communities being extremely fit to naphthalene utilisation and non-stimulated communities exhibiting a greater metabolic window than previously predicted. On the basis of comparing protein expression profiles and metagenome data sets, inter-alia interactions among members were hypothesised. The utilisation of curated databases is discussed and used for first time to reconstruct ‘presumptive’ degradation networks for complex microbial communities.
Increased Death of Adipose Cells, a Path to Release Cell‐Free DNA Into Systemic Circulation of Obese Women
Authors: Haghiac Maricela , Vora Neeta L. , Basu Subhabrata , Johnson Kirby L. , Presley Larraine , Bianchi Diana W. , De Mouzon Sylvie Hauguel
Published: July 2012

Remodeling of adipose tissue is required to support the expansion of adipose mass. In obesity, an increased death of adipocytes contributes to the accelerated cellular turnover. We have shown that obesity in pregnancy is associated with metabolic and immune alterations in the adipose tissue. In this study, we characterized the mechanisms responsible for increased death of adipose cells of pregnant obese women and its functional consequences. We postulated that a higher turnover of dead cells in white adipose tissue of obese women would translate into release of cell‐free DNA (cfDNA) into their systemic circulation. Increase in adipose mass of obese compared to lean women results from a lesser number of hypertrophic adipocytes and an accumulation of macrophages in the stromal vascular fraction (SVF). The adipocytes of obese displayed enhanced necrosis with a loss of perilipin staining at the plasma membrane. Apoptosis was prominent in SVF cells with an increased expression of caspase 9 and caspase 3 and a higher rate of terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate nick end‐labeling (TUNEL) positive CD68 macrophages in obese vs. lean. Whereas circulating fetal cfDNA concentrations were not changed, there was a twofold increase in circulating glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) cfDNA and adipose tissue GAPDH mRNA in obese women. The maternal systemic GAPDH cfDNA was positively correlated with BMI and gestational weight gain. These data suggest that the active remodeling of adipose tissue of obese pregnant women results in an increased release of cfDNA of maternal origin into the circulation.
Developing controlled environment screening for high-temperature tolerance in cotton that accurately reflects performance in the field
Authors: Cottee Nicola S. , Bange Michael P. , Wilson Iain W. , Tan Daniel K. Y.
Published: July 2012

In this study we investigated the heat tolerance of high yielding Australian cotton (Gossypium hirsutum L.) cultivars using a multi-level approach encompassing physiological assays and measurements of performance. Two cultivars with known field performance were evaluated for heat tolerance under optimal (32°C) and high (42°C) temperatures in a growth cabinet with a cell membrane integrity assay. Impacts of temperature on growth were evaluated with leaf level measurements of gas exchange and chlorophyll fluorescence. To extend the multi-level approach, the expression of a Rubisco activase regulating gene (GhRCAα2) was also determined. Consistent with previously determined differences in the field, cultivar Sicot 53 outperformed Sicala 45 for the cell membrane integrity assay; this finding was reflective of cultivar differences in gas exchange and chlorophyll fluorescence. Cultivar differences were also consistent for expression of GhRCAα2, which may also help explain differences in physiological performance, particularly photosynthesis. This study reaffirmed that physiological and molecular assays were sufficiently sensitive to resolve genotypic differences in heat tolerance and that these differences translate to physiological performance. By comparing performance under high temperatures in the growth cabinet and field, this approach validates the use of rapid screening tools in conjunction with a multi-level approach for heat tolerance detection.
Expression of a second receptor rescues self-specific T cells from thymic deletion and allows activation of autoreactive effector function.
Authors: Zal T , Weiss S , Mellor A , Stockinger B
Published: July 2012

Allelic exclusion at the T-cell receptor alpha chain locus is incomplete resulting in the generation of T cells that express two T-cell receptors. The potential involvement of such T cells in autoimmunity has been suggested [Padovan, E., Casorati, G., Dellabona, P., Meyer, S., Brockhaus, M. & Lanzavecchia, A. (1993) Science 262, 422-424; Heath, W. R. & Miller, J. F. A. P. (1993) J. Exp. Med. 178, 1807-1811]. Here we show that expression of a second T-cell receptor can rescue T cells with autospecific receptors from thymic deletion and allow their exit into the periphery. Dual receptor T cells, created by constitutive expression of two transgenic T-cell receptors on a Rag1-/- background, are tolerant to self by maintaining low levels of autospecific receptor, but selfreactive effector function (killing) can be induced through activation via the second receptor. This opens the possibility that T cells carrying two receptors in the periphery of normal individuals contain putatively autoreactive cells that could engage in autoimmune effector functions after recognition of an unrelated environmental antigen.
The structure of scientific collaboration networks
Authors: Newman M. E. J.
Published: July 2012

The structure of scientific collaboration networks is investigated.
Two scientists are considered connected if they have authored a paper
together and explicit networks of such connections are constructed by
using data drawn from a number of databases, including MEDLINE
(biomedical research), the Los Alamos e-Print Archive (physics), and
NCSTRL (computer science). I show that these collaboration networks
form “small worlds,” in which randomly chosen pairs of scientists
are typically separated by only a short path of intermediate
acquaintances. I further give results for mean and distribution of
numbers of collaborators of authors, demonstrate the presence of
clustering in the networks, and highlight a number of apparent
differences in the patterns of collaboration between the fields
studied.
Coupling of histone deacetylation to NAD breakdown by the yeast silencing protein Sir2: Evidence for acetyl transfer from substrate to an NAD breakdown product
Authors: Tanny Jason C. , Moazed Danesh
Published: July 2012

The
Saccharomyces cerevisiae
silencing protein Sir2
is the founding member of a universally conserved family of proteins
that have been shown to possess NAD-dependent histone deacetylation and
ADP-ribosylation activities. Here we show that histone deacetylation by
Sir2 is coupled to cleavage of the high-energy bond that links the
ADP-ribose moiety of NAD to nicotinamide. Analysis of the NAD cleavage
products revealed the presence of nicotinamide, ADP-ribose, and a third
product that appeared to be related to ADP-ribose. With the use of
label transfer experiments, we show that the acetyl group in the
histone substrate is transferred to this NAD breakdown product during
deacetylation, forming a product that we conclude to be
O
-acetyl-ADP-ribose. Detection of this species strongly
argues for obligate coupling of histone deacetylation to NAD breakdown
by Sir2. We propose reaction mechanisms that could account for this
coupling via acetyl-ADP-ribose formation. The unprecedented coupling of
amide bond cleavage to cleavage of a high-energy bond raises the
possibility that NAD breakdown by Sir2 plays an important role in
silencing that is independent of its requirement for deacetylation.
Catalytic mechanism of quinoprotein methanol dehydrogenase: A theoretical and x-ray crystallographic investigation
Authors: Zheng Ya-Jun , Xia Zong-xiang , Chen Zhi-wei , Mathews F. Scott , Bruice Thomas C.
Published: July 2012

The catalytic mechanism of the reductive half reaction of the
quinoprotein methanol dehydrogenase (MDH) is believed to proceed either
through a hemiketal intermediate or by direct transfer of a hydride ion
from the substrate methyl group to the cofactor, pyrroloquinoline
quinone (PQQ). A crystal structure of the enzyme-substrate complex of a
similar quinoprotein, glucose dehydrogenase, has recently been reported
that strongly favors the hydride transfer mechanism in that enzyme. A
theoretical analysis and an improved refinement of the 1.9-Å
resolution crystal structure of MDH from
Methylophilus
methylotrophus
W3A1 in the presence of methanol, reported
earlier, indicates that the observed tetrahedral configuration of the
C-5 atom of PQQ in that study represents the C-5-reduced form of the
cofactor and lends support for a hydride transfer mechanism for MDH.