1,365 research outputs found

    Exploring elite soccer teams’ performances during different match-status periods of close matches’ comebacks

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    The aim of the present study was to examine winning and losing teams’ performances during the four different match-status periods that occur in close soccer matches’ comebacks (1° drawing; 2° winning/losing; 3° drawing; and 4° losing/winning). The variables (i.e., shots, passing effectiveness and ball possession) were gathered from 17 matches of the Spanish professional soccer league. Relative-phase analysis of ball possession between teams revealed a shift from anti-phase to in-phase relations from period 1 to 4. Pass efficacy revealed a particular trend of anti-phase relations in period 2 and the analysis of shots revealed similar phase relations between periods. Statistically significant differences were observed between winning and losing teams in Period 3 for ball possession and passing effectiveness. Also, statistically significant differences among periods were observed for winning teams in ball possession with period 4 as the most differentiated from the other periods. Besides, winning teams also showed significant differences between periods in passing effectiveness (period 4 vs 3), and in shots (period 3 vs periods 1, 2 and 4). On the other hand, ball possession showed significant differences for losing teams with periods 3 and 4 different than periods 1 and 2. The current findings can be used when controlling match-status scenarios and key performance indicators along the match

    Si-to-Si wafer bonding using evaporated glass

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    Where the linearized Poisson-Boltzmann cell model fails: (I) spurious phase separation in charged colloidal suspensions

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    We perform a linearization of the Poisson-Boltzmann (PB) density functional for spherical Wigner-Seitz cells that yields Debye-H\"uckel-like equations agreeing asymptotically with the PB results in the weak-coupling (high-temperature) limit. Both the canonical (fixed number of microions) as well as the semi-grand-canonical (in contact with an infinite salt reservoir) cases are considered and discussed in a unified linearized framework. In the canonical case, for sufficiently large colloidal charges the linearized theory predicts the occurrence of a thermodynamical instability with an associated phase separation of the homogeneous suspension into dilute (gas) and dense (liquid) phases. In the semi-grand-canonical case it is predicted that the isothermal compressibility and the osmotic-pressure difference between the colloidal suspension and the salt reservoir become negative in the low-temperature, high-surface charge or infinite-dilution (of polyions) limits. As already pointed out in the literature for the latter case, these features are in disagreement with the exact nonlinear PB solution inside a Wigner-Seitz cell and are thus artifacts of the linearization. By using explicitly gauge-invariant forms of the electrostatic potential we show that these artifacts, although thermodynamically consistent with quadratic expansions of the nonlinear functional and osmotic pressure, may be traced back to the non-fulfillment of the underlying assumptions of the linearization.Comment: 32 pages, 3 PostScript figures, submitted to J. Chem. Phy

    Spatial and temporal distribution of atmospheric aerosols in the lowermost troposphere over the Amazonian tropical rainforest

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    International audienceWe present measurements of aerosol physico-chemical properties below 5 km altitude over the tropical rain forest and the marine boundary layer (MBL) obtained during the LBA-CLAIRE 1998 project. The MBL aerosol size distribution some 50-100km of the coast of French Guyana and Suriname showed a bi-modal shape typical of aged and cloud processed aerosol. The average particle number density in the MBL was 383cm-3. The daytime mixed layer height over the rain forest for undisturbed conditions was estimated to be between 1200-1500m. During the morning hours the height of the mixed layer increased by 144-180mh-1. The median daytime aerosol number density in the mixed layer increased from 450cm-3 in the morning to almost 800cm-3 in the late afternoon. The evolution of the aerosol size distribution in the daytime mixed layer over the rain forest showed two distinct patterns. Between dawn and midday, the Aitken mode particle concentrations increased, whereas later during the day, a sharp increase of the accumulation mode aerosol number densities was observed, resulting in a doubling of the morning accumulation mode concentrations from 150cm-3 to 300cm-3. Potential sources of the Aitken mode particles are discussed here including the rapid growth of ultrafine aerosol particles formed aloft and subsequently entrained into the mixed layer, as well as the contribution of emissions from the tropical vegetation to Aitken mode number densities. The observed increase of the accumulation mode aerosol number densities is attributed to the combined effect of: the direct emissions of primary biogenic particles from the rain forest and aerosol in-cloud processing by shallow convective clouds. Based on the similarities among the number densities, the size distributions and the composition of the aerosol in the MBL and the nocturnal residual layer we propose that the air originating in the MBL is transported above the nocturnal mixed layer up to 300-400km inland over the rain forest by night without significant processing

    Effects of Culture on Preferred Individual Learning Systems: Consequences for Knowledge Management System Use

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    Global enterprises increasingly deploy Knowledge Management Systems (KMSs) to raise productivity and remain competitive. KMSs, by prescribing ways of capturing and disseminating information, mediate the learning processes in organizations. Because of this mediating effect, individuals from distinct national cultures may react differently to KMSs. This research examines how cultural characteristics (e.g., those identified by Hofstede, Trompenaars, and Hall and Hall) may be related to the individual use of KMSs for learning. The first phase of the study examines individual cultural characteristics and learning preferences (degree of structure and extent of direct social interactions). The second phase examines the relationships between cultural measures and actual KMS use

    Single particle analysis of the accumulation mode aerosol over the northeast Amazonian tropical rain forest, Surinam, South America

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    International audienceSingle particle analysis of aerosols particles larger than 0.2 ?m diameter was performed on 24 samples collected over Surinam tropical rain forest and in the adjacent marine boundary layer (MBL) during the LBA-CLAIRE 98 campaign in March 1998. Elemental composition and morphology of 2308 particles was determined using SEM-EDX. The aerosol particles were divided into seven groups according to their chemical composition: organic particles, mineral dust, aged mineral dust, sea salt, aged sea salt, Ca-rich, and biogenic aerosol. However the organic material in aerosol particles cannot be identified directly by SEM-EDX, we present indirect method of detection of organic material using this technique. Samples were further divided with respect to the distinct atmospheric layers present in the tropical troposphere including MBL, continental mixed layer, cloud convective layer, free troposphere and region of deep convection outflow. The organic and mineral dust particles are two major groups observed over the rainforest. In the MBL also sea salt particles represented a large fraction between 15 and 27%. The organic particles control much of the chemical characteristic of the aerosol in the continental tropical troposphere. Their abundance ranged from less than 20% in the MBL to more than 90% in the free troposphere between 4.5- and 12.6-km altitude. During the transport of the air masses from the MBL over the rain forest, fraction of organic aerosol particles more than doubled, reaching 40?60% in the continental boundary layer. This increase was attributed to direct emissions of biogenic aerosols from the tropical vegetation. The high fraction of the organic accumulation mode particles in the upper tropical troposphere could be a good indicator for the air masses originated over the tropical rain forest

    Of sound mind and body: depression, disease, and accelerated aging

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    Major depressive disorder (MDD) is associated with a high rate of developing serious medical comorbidities such as cardiovascular disease, stroke, dementia, osteoporosis, diabetes, and the metabolic syndrome. These are conditions that typically occur late in life, and it has been suggested that MDD may be associated with “accelerated aging.” We review several moderators and mediators that may accompany MDD and that may give rise to these comorbid medical conditions. We first review the moderating effects of psychological styles of coping, genetic predisposition, and epigenetic modifications (eg, secondary to childhood adversity). We then focus on several interlinked mediators occurring in MDD (or at least in subtypes of MDD) that may contribute to the medical comorbidity burden and to accelerated aging: limbic-hypothalamic-pituitary-adrenal axis alterations, diminution in glucocorticoid receptor function, altered glucose tolerance and insulin sensitivity, excitotoxicity, increases in intracellular calcium, oxidative stress, a proinflammatory milieu, lowered levels of “counter-regulatory” neurosteroids (such as allopregnanolone and dehydroepiandrosterone), diminished neurotrophic activity, and accelerated cell aging, manifest as alterations in telomerase activity and as shortening of telomeres, which can lead to apoptosis and cell death. In this model, MDD is characterized by a surfeit of potentially destructive mediators and an insufficiency of protective or restorative ones. These factors interact in increasing the likelihood of physical disease and of accelerated aging at the cellular level. We conclude with suggestions for novel mechanism-based therapeutics based on these mediators

    Uma nova diposição fundamental: Heidegger e as Contribuições à filosofia

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    Este artigo expõe algumas das características da nova disposição fundamental (Grundstimmung) que emerge na obra Contribuições à Filosofia (Beiträge zur Philosophie), de Martin Heidegger. Neste livro, Heidegger iniciou a transição de uma filosofia centrada na análise do ser-aí para outra que visa escutar ou lembrar os modos como o Seer (Seyn) se manifestou ao longo da História. Ele mesmo admite ressonâncias do primeiro modo de filosofar no segundo. Destarte, faz-se breve apresentação de como o tema das disposições é ventilado em Ser e Tempo, a fim de se entender a disposição fundamental, a angústia; e em seguida, delineando ligeiramente o horizonte filosófico das Contribuições, analisa-se o tratamento dispensado à nova disposição, a retenção. A conclusão geral é de que Heidegger mantém compreensão similar das disposições em ambas as obras, apesar das diferenças específicas que subsistem entre cada uma dessas tonalidades afetivas.      
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