Timing and localization of ionospheric signatures associated with substorm expansion phase onset

In this paper, we present case studies of the optical and magnetic signatures of the characteristics of the first minute of substorm expansion phase onset observed in the ionosphere. We find that for two isolated substorms, the onset of magnetic pulsations in the 24–96 s period wavelet band are colocated in time and space with the formation and development of small-scale optical undulations along the most equatorward preexisting auroral arc prior to auroral breakup. These undulations undergo an inverse spatial cascade into vortices prior to the release of the westward traveling surge. We also present a case study of a multiple activation substorm, whereby discrete onsets of ULF wave power above a predetermined quiet time threshold are shown to be associated with specific optical intensifications and brightenings. Moreover, in the multiple activation substorm event, we show that neither the formation of the small-scale undulations nor the formation of similar structures along a north–south aligned arc is sufficient to produce auroral breakup associated with expansion phase onset. It is only ∼10 min after these two disparate activation regions initiate that auroral breakup and the subsequent formation of a westward traveling surge occur. We discuss the implications of these results in terms of the triggering mechanisms likely to be occurring during these specific events.

Atmospheric cosmic rays in the South Atlantic anomaly region

To study the production and propagation of fast secondaries particles in the atmosphere, data collected during eleven quiet-time balloon flights are analysed. Comparisons of these data with those obtained in different geomagnetic rigidity regions permit to estimate the contributions of the proton and electron components in the measured intensities. Derivations of this last component in the «upward» and «downward» moving electrons fluxes indicate that in the anomaly region a fraction of these particles, produced by the primary protons, are leaving the atmosphere and will not return to the Earth. © 1991 Società Italiana di Fisica.

Abnormal evening vertical plasma drift and effects on ESF and EIA over Brazil-South Atlantic sector during the 30 October 2003 superstorm

Equatorial F region vertical plasma drifts, spread F and anomaly responses, in the south American longitude sector during the superstorm of 30 October 2003, are analyzed using data from an array of instruments consisting of Digisondes, a VHF radar, GPS TEC and scintillation receivers in Brazil, and a Digisonde and a magnetometer in Jicamarca, Peru. Prompt penetrating eastward electric field of abnormally large intensity drove the F layer plasma up at a velocity ∼1200 ms -1 during post dusk hours in the eastern sector over Brazil. The equatorial anomaly was intensified and expanded poleward while the development of spread F/plasma bubble irregularities and GPS signal scintillations were weaker than their quiet time intensity. Significantly weaker F region response over Jicamarca presented a striking difference in the intensity of prompt penetration electric field between Peru and eastern longitudes of Brazil. The enhanced post dusk sector vertical drift over Brazil is attributed to electro-dynamics effects arising energetic particle precipitation in the South Atlantic Magnetic Anomaly (SAMA). These extraordinary results and their longitudinal differences are presented and discussed in this paper. Copyright 2008 by the American Geophysical Union.

Developing Smooth, Quiet, Safe Portland Cement Concrete Pavements, March 2004

The concrete paving industry has spent large amounts of time working to provide safe, quiet, and smooth pavements for the traveling public as their needs and driving habits have changed since the advent of the automobile. During that time, the efforts of research, design, and construction were directed at one of the problems at a time. Current public surveys indicate that the traveling public wishes to have safe, quiet, and smooth pavements. This report identifies the problems remaining in the areas of developing smooth, quiet, and safe portland cement concrete pavement in each pavement we build. It develops the research framework that can be used to bring the existing information together with additional research in each area. The resulting answers can be used in each pavement design for a quiet, safe, and smooth pavement that is also long lasting.

The quiet eye and tasks demands: Do tougher shots need a quieter eye?

The Quiet Eye (QE; Vickers 1996) has been shown to underpin successful performance, differentiating both expertise (inter-individual) and proficiency (intra-individual), with experts and successful attempts characterised by longer QE durations. The QE is proposed to reflect the time needed to organise and fine tune the parameters of movement (e.g. force and direction). In order to examine this prediction and build upon previous research we experimentally manipulated the difficulty of a golf putting task; we hypothesised that if the QE is related to motor programming then a more difficult task should be associated with longer QE durations. 33 golfers (M age= 21.16, SD= 3.98) with an average handicap of 6.5 (SD= 6.02) performed putts in 4 conditions of increasing difficulty. We manipulated the length of the golf putt (short-4ft, long-8ft) and the contact point of the putter head (large-1.7cm, small-0.5cm,) giving increasingly difficult putting conditions of short-large [1], short-small [2], long-large [3] and long-small [4]. We measured performance (radial error from hole in cm) and QE (in ms) for 10 putts in each condition. A repeated measures ANOVA was performed on the performance and QE data. The performance data suggest that we were successful in increasing the difficulty of the task (F (3,93) = 26.46. p = .000), with the best performance in condition [1] (8.57cm), followed by [2] (9.10cm) followed by [3] (16.11cm) and finally the worst performance was in condition [4] (23.40cm). The QE data suggest that, in keeping with our hypothesis, the QE was lengthened as task difficulty increased (F (3,87) = 11.91, p = .043). The QE was shortest in condition [1] (1787.85ms) and increased to condition [2] (1939.78ms) and condition [3] (2076.51ms), with the longest QE in condition [4] (2164.08ms). More detailed analysis of the QE reveal that it was the proportion of the QE that occurred before movement initiation (pre-QE) which increased with shot difficulty, rather than the proportion that occurred during the swing (Online-QE; see Vine et al., 2013). Results support the notion that more complex tasks are associated with a longer QE duration, specifically participants appear to spend longer fixating the target prior to movement. This likely reflects the time needed to process visual information gathered in a pre-performance routine, to inhibit external distraction, and to pre-programme the increasingly difficult parameters of the movement. Vickers, J.N. (1996). Visual control when aiming at a far target. Journal of Experimental Psychology: Human Perception and Performance, 22, 342-354. Vine, S.J. et al. (2013). Quiet eye and choking: Online control breaks down at the point of performance failure. Medicine and Science in Sports and Exercise, 45, 1988-1994.

The quiet eye without a target: The primacy of visual information processing

Motor-performance-enhancing effects of long final fixations before movement initiation – a phenomenon called Quiet Eye (QE) – have repeatedly been demonstrated. Drawing on the information-processing framework, it is assumed that the QE supports information processing revealed by the close link between QE duration and task demands concerning, in particular, response selection and movement parameterisation. However, the question remains whether the suggested mechanism also holds for processes referring to stimulus identification. Thus, in a series of two experiments, performance in a targeting task was tested as a function of experimentally manipulated visual processing demands as well as experimentally manipulated QE durations. The results support the suggested link because a performance-enhancing QE effect was found under increased visual processing demands only: Whereas QE duration did not affect performance as long as positional information was preserved (Experiment 1), in the full vs. no target visibility comparison, QE efficiency turned out to depend on information processing time as soon as the interval falls below a certain threshold (Experiment 2). Thus, the results rather contradict alternative, e.g., posture-based explanations of QE effects and support the assumption that the crucial mechanism behind the QE phenomenon is rooted in the cognitive domain.

Build-up and resetting of auditory stream segregation in quiet and in complex-tone backgrounds

Thirteen experiments investigated the dynamics of stream segregation. Experiments 1-6b used a similar method, where a same-frequency induction sequence (usually 10 repetitions of an identical pure tone) promoted segregation in a subsequent, briefer test sequence (of alternating low- and high-frequency tones). Experiments 1-2 measured streaming using a direct report of perception and a temporal-discrimination task, respectively. Creating a single deviant by altering the final inducer (e.g. in level or replacement with silence) reduced segregation, often substantially. As the prior inducers remained unaltered, it is proposed that the single change actively reset build-up. The extent of resetting varied gradually with the size of a frequency change, once noticeable (experiments 3a-3b). By manipulating the serial position of a change, experiments 4a-4b demonstrated that resetting only occurred when the final inducer was replaced with silence, as build-up is very rapid during a same-frequency induction sequence. Therefore, the observed resetting cannot be explained by fewer inducers being presented. Experiment 5 showed that resetting caused by a single deviant did not increase when prior inducers were made unpredictable in frequency (four-semitone range). Experiments 6a-6b demonstrated that actual and perceived continuity have a similar effect on subsequent streaming judgements promoting either integration or segregation, depending on listening context. Experiment 7 found that same-frequency inducers were considerably more effective at promoting segregation than an alternating-frequency inducer, and that a trend for deviant-tone resetting was only apparent for the same-frequency case. Using temporal-order judgments, experiments 8-9 demonstrated the stream segregation of pure-tone-like percepts, evoked by sudden changes in amplitude or interaural time difference for individual components of a complex tone, Active resetting was observed when a deviant was inserted into a sequence of these percepts (Experiment 10). Overall, these experiments offer new insight into the segregation-promotIng effect of induction sequences, and the factors which can reset this effect.

Participatory filmmaking with Qur’anic students in Kano, Nigeria: ‘speak good about us or keep quiet!’

‘Participatory’ research is often presented as a means to ‘empower’ stigmatised groups by addressing shame and by promoting attitude changes. Drawing on experiences producing a ‘participatory’ docudrama with traditional Qur’anic students (almajirai) in Kano, northern Nigeria, I reflect on the limits of ‘participatory’ research as a tool for ‘empowerment’. I describe the risks stigmatised groups may incur by participating, and consider to what extent, if at all, it can foster social change. The almajirai have attracted negative attention as presumed victims of child neglect and as ‘cannon fodder’ for Islamic radicalisation. Their participation in the filmmaking gave them an opportunity to voice their concerns and to rebuke those treating them heedlessly. At the same time, they became vulnerable to accusations and suspicions within their communities. To escape the negative connotations of poverty, they deemphasised its role for almajiri enrolment, thus concealing structural inequalities.

The storage and dissipation of magnetic energy in the quiet sun corona determined from SDO/HMI magnetograms

In recent years, higher cadence, higher resolution observations have revealed the quiet-Sun photosphere to be complex and rapidly evolving. Since magnetic fields anchored in the photosphere extend up into the solar corona, it is expected that the small-scale coronal magnetic field exhibits similar complexity. For the first time, the quiet-Sun coronal magnetic field is continuously evolved through a series of non-potential, quasi-static equilibria, deduced from magnetograms observed by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, where the photospheric boundary condition which drives the coronal evolution exactly reproduces the observed magnetograms. The build-up, storage, and dissipation of magnetic energy within the simulations is studied. We find that the free magnetic energy built up and stored within the field is sufficient to explain small-scale, impulsive events such as nanoflares. On comparing with coronal images of the same region, the energy storage and dissipation visually reproduces many of the observed features. The results indicate that the complex small-scale magnetic evolution of a large number of magnetic features is a key element in explaining the nature of the solar corona.

Identification Of Corynebacterium Spp. Isolated From Bovine Intramammary Infections By Matrix-assisted Laser Desorption Ionization-time Of Flight Mass Spectrometry.

Corynebacterium species (spp.) are among the most frequently isolated pathogens associated with subclinical mastitis in dairy cows. However, simple, fast, and reliable methods for the identification of species of the genus Corynebacterium are not currently available. This study aimed to evaluate the usefulness of matrix-assisted laser desorption ionization/mass spectrometry (MALDI-TOF MS) for identifying Corynebacterium spp. isolated from the mammary glands of dairy cows. Corynebacterium spp. were isolated from milk samples via microbiological culture (n=180) and were analyzed by MALDI-TOF MS and 16S rRNA gene sequencing. Using MALDI-TOF MS methodology, 161 Corynebacterium spp. isolates (89.4%) were correctly identified at the species level, whereas 12 isolates (6.7%) were identified at the genus level. Most isolates that were identified at the species level with 16 S rRNA gene sequencing were identified as Corynebacterium bovis (n=156; 86.7%) were also identified as C. bovis with MALDI-TOF MS. Five Corynebacterium spp. isolates (2.8%) were not correctly identified at the species level with MALDI-TOF MS and 2 isolates (1.1%) were considered unidentified because despite having MALDI-TOF MS scores >2, only the genus level was correctly identified. Therefore, MALDI-TOF MS could serve as an alternative method for species-level diagnoses of bovine intramammary infections caused by Corynebacterium spp.

A Metabolomic Protocol For Plant Systematics By Matrix-assisted Laser-desorption/ionization Time-of Flight Mass Spectrometry.

Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS) has been widely used for the identification and classification of microorganisms based on their proteomic fingerprints. However, the use of MALDI-TOF MS in plant research has been very limited. In the present study, a first protocol is proposed for metabolic fingerprinting by MALDI-TOF MS using three different MALDI matrices with subsequent multivariate data analysis by in-house algorithms implemented in the R environment for the taxonomic classification of plants from different genera, families and orders. By merging the data acquired with different matrices, different ionization modes and using careful algorithms and parameter selection, we demonstrate that a close taxonomic classification can be achieved based on plant metabolic fingerprints, with 92% similarity to the taxonomic classifications found in literature. The present work therefore highlights the great potential of applying MALDI-TOF MS for the taxonomic classification of plants and, furthermore, provides a preliminary foundation for future research.

Profile Of Phenolic Compounds Of Brazilian Virgin Olive Oils By Rapid Resolution Liquid Chromatography Coupled To Electrospray Ionisation Time-of-flight Mass Spectrometry (rrlc-esi-tof-ms).

In recent years, agronomical researchers began to cultivate several olive varieties in different regions of Brazil to produce virgin olive oil (VOO). Because there has been no reported data regarding the phenolic profile of the first Brazilian VOO, the aim of this work was to determine phenolic contents of these samples using rapid-resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry. 25 VOO samples from Arbequina, Koroneiki, Arbosana, Grappolo, Manzanilla, Coratina, Frantoio and MGS Mariense varieties from three different Brazilian states and two crops were analysed. It was possible to quantify 19 phenolic compounds belonging to different classes. The results indicated that Brazilian VOOs have high total phenolic content because the values were comparable with those from high-quality VOOs produced in other countries. VOOs from Coratina, Arbosana and Grappolo presented the highest total phenolic content. These data will be useful in the development and improvement of Brazilian VOO.

Análise do jogo de goalball : modelação e interpretação dos padrões de jogo da Paralimpíada de Pequim 2008

Universidade Estadual de Campinas . Faculdade de Educação Física

Effect of cement type and water storage time on the push-out bond strength of a glass fiber post

This study investigated the effects of the cement type and the water storage time on the push-out bond strength of a glass fiber post. Glass fiber posts (Fibrekor, Jeneric Pentron) were luted to post spaces using a self-cured resin cement (C&B Cement [CB]), a glass ionomer cement (Ketac Cem [KC]) or a resin-modified glass ionomer cement (GC FujiCEM [FC]) according to the manufacturers’ instructions. For each luting agent, the specimens were exposed to one of the following water storage times (n=5): 1 day (T1), 7 days (T7), 90 days (T90) and 180 days (T180). Push-out tests were performed after the storage times. Control specimens were not exposed to water storage, but subjected to the push-out test 10 min after post cementation. Data (in MPa) were analyzed by Kruskal-Wallis and Dunn`s test (α=0.05). Cement type and water storage time had a significant effect (p<0.05) on the push-out bond strength. CB showed significantly higher values of retention (p<0.05) than KC and FC, irrespective of the water storage time. Water storage increased significantly the push-out bond strength in T7 and T90, regardless of the cement type (p<0.05). The results showed that fiber posts luted to post spaces with the self-cured resin cement exhibited the best bonding performance throughout the 180-day water storage period. All cements exhibited a tendency to increase the bond strength after 7 and 90 days of water storage, decreasing thereafter.

Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

This in vitro study evaluated the cytotoxicity of an experimental restorative composite resin subjected to different light-curing regimens. METHODS: Forty round-shaped specimens were prepared and randomly assigned to four experimental groups (n=10), as follows: in Group 1, no light-curing; in Groups 2, 3 and 4, the composite resin specimens were light-cured for 20, 40 or 60 s, respectively. In Group 5, filter paper discs soaked in 5 µL PBS were used as negative controls. The resin specimens and paper discs were placed in wells of 24-well plates in which the odontoblast-like cells MDPC-23 (30,000 cells/cm²) were plated and incubated in a humidified incubator with 5% CO2 and 95% air at 37ºC for 72 h. The cytotoxicity was evaluated by the cell metabolism (MTT assay) and cell morphology (SEM). The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: In G1, cell metabolism decreased by 86.2%, indicating a severe cytotoxicity of the non-light-cured composite resin. On the other hand, cell metabolism decreased by only 13.3% and 13.5% in G2 and G3, respectively. No cytotoxic effects were observed in G4 and G5. In G1, only a few round-shaped cells with short processes on their cytoplasmic membrane were observed. In the other experimental groups as well as in control group, a number of spindle-shaped cells with long cytoplasmic processes were found. CONCLUSION: Regardless of the photoactivation time used in the present investigation, the experimental composite resin presented mild to no toxic effects to the odontoblast-like MDPC-23 cells. However, intense cytotoxic effects occurred when no light-curing was performed.