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Talent identification (TID) and development (TDE) are large fields in professional soccer and in science. However, TID and TDE processes in youth academies have not been assessed in detail. As such, our aim was to survey professional clubs from around the world about their youth academy TID and TDE processes, with 29 clubs responding to the survey. TID and TDE processes changed as a function of player age. TID processes involved finding the best players locally and regionally, but for older players the search widened to nationally and internationally for the needs of the first team. Clubs used a multidisciplinary approach to TID, but more so with older players. Median number of academy players was 80, 100, and 66 players at 8–11 years, 12–16 years, and 17–21 years, respectively. Annual player turnover in the most recent season (selections/de-selections) was 29% across all age groups, with competition from other clubs cited as a limitation to TID. TDE processes involved weekly matches and 3–5 training sessions per week led by experienced, well-qualified coaches, with most clubs providing players with academic education, residency and transportation services. Our findings extend previous research assessing professional soccer youth academy TID and TDE processes by quantifying worldwide practices. [ABSTRACT FROM AUTHOR]

Designing discrete time variable structure control with sliding mode (SM) schemes implies finding an asymptotically stable sliding surface with a control policy which assures the existence of a SM. Based on a recently innovative approach, where the authors developed a flexible design of sliding surfaces applied to discrete time linear multi-input multi-output (MIMO) systems, a novelty controller design strategy is proposed, where a switching surface parameter is used for the adjustment of the control signal limitations and for the improvement of the controlled system dynamics against model uncertainties. It is the first time that these drawbacks are solved modifying the switching surface values because it has been always resolved via control law adjustment. Moreover, a new chattering elimination method using adjustable sigmoid functions is also implemented in the controller. The main advantages of the proposed methodology are: firstly, it can be easily applied to high-order linear MIMO systems; secondly, system dynamics coordinates representation transformations are not needed and thirdly, the non-ideal SM dynamics is considered in the design procedure. Both the sliding surface and the control law specification are included in the proposed methodology. An illustrative example is included. [ABSTRACT FROM AUTHOR]

Designing discrete time variable structure control with sliding mode (SM) schemes implies finding an asymptotically stable sliding surface with a control policy which assures the existence of a SM. Based on a recently innovative approach, where the authors developed a flexible design of sliding surfaces applied to discrete time linear multi‐input multi‐output (MIMO) systems, a novelty controller design strategy is proposed, where a switching surface parameter is used for the adjustment of the control signal limitations and for the improvement of the controlled system dynamics against model uncertainties. It is the first time that these drawbacks are solved modifying the switching surface values because it has been always resolved via control law adjustment. Moreover, a new chattering elimination method using adjustable sigmoid functions is also implemented in the controller. The main advantages of the proposed methodology are: firstly, it can be easily applied to high‐order linear MIMO systems; secondly, system dynamics coordinates representation transformations are not needed and thirdly, the non‐ideal SM dynamics is considered in the design procedure. Both the sliding surface and the control law specification are included in the proposed methodology. An illustrative example is included. [ABSTRACT FROM AUTHOR]

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Summary: As regards to variable structure control with sliding mode (VSC‐SM), it is known that designing sliding surface is a critical task because sliding surfaces must guarantee that the steady state of the controlled system achieves some desired performance including global (or global asymptotic) stability. This problem has been extensively analyzed for a wide class of systems: scalar, multivariable, linear, nonlinear, time‐variant, discrete‐time system, etc. The main purpose of this paper is to present a thorough survey about the main approaches related to the design of discrete‐time switching surfaces applied to VSC‐SM. Research works covering the design of sliding surfaces for the aforementioned systems are considered and some illustrative examples are also included to explain some of the design methodologies. [ABSTRACT FROM AUTHOR]

Designing variable structure control with sliding mode (VSC-SM) control schemes needs a switching function or a sliding surface which guarantees the global stability of the closed-loop system. Despite the fact that a wide range of design approaches has been proposed for solving this mathematical problem, the number of proposed methodologies for nonlinear systems is not very extensive, especially for discrete time nonlinear MIMO systems, and most of them require some coordinate system transformation. Therefore, it is not an easy task to find a design scheme that can be applied to discrete time nonlinear MIMO systems. The proposed methodology introduces a mathematical tool: a switching surface equation for a class of MIMO nonlinear systems through an explicit equation without any coordinate transformation. This equation makes use of an implicit linearizing process via the Taylor expansion that allows the use of linear procedures for the design of switching surfaces and the forward Euler method to obtain a discrete time dynamics representation. An illustrative example is included to show the advantages of the proposed design methodology. [ABSTRACT FROM AUTHOR]

The design of sliding switching surfaces consist in finding a manifold where the controlled system dynamics are asymptotically stable. This problem has been studied for a long time, during which a wide range of designing approaches has been proposed, which can be classified into two research methodologies; the first one corresponding to eigenvalues designing approaches and the second one is based on optimal approaches. In addition, some research approaches only can be applied to specific type of systems, e.g. single-input single-output systems or continuous time systems. Finally, the performance or the level of the achieved accuracy among the different approaches varies significantly. The proposed approach facilitates the task of designing sliding surfaces applied to multi-input multi-output (MIMO) linear systems. The presented methodology introduces a switching surface for MIMO linear systems through a simple equation that allows both eigenvalues placement design or optimal methods without any coordinate system representation transformation. In addition, a design parameter is also included for the adjustment of the non-ideal dynamics. Moreover, this approach guarantees high accuracy of the system dynamics, either for arbitrary eigenvalues assignment or for optimal switching surface definitions. In addition, these benefits are attained using a single switching surface equation. An illustrative example is included to show the advantages of the proposed design methodology. [ABSTRACT FROM AUTHOR]

The design of sliding switching surfaces consist in finding a manifold where the controlled system dynamics are asymptotically stable. This problem has been studied for a long time, during which a wide range of designing approaches has been proposed, which can be classified into two research methodologies; the first one corresponding to eigenvalues designing approaches and the second one is based on optimal approaches. In addition, some research approaches only can be applied to specific type of systems, e.g. single‐input single‐output systems or continuous time systems. Finally, the performance or the level of the achieved accuracy among the different approaches varies significantly. The proposed approach facilitates the task of designing sliding surfaces applied to multi‐input multi‐output (MIMO) linear systems. The presented methodology introduces a switching surface for MIMO linear systems through a simple equation that allows both eigenvalues placement design or optimal methods without any coordinate system representation transformation. In addition, a design parameter is also included for the adjustment of the non‐ideal dynamics. Moreover, this approach guarantees high accuracy of the system dynamics, either for arbitrary eigenvalues assignment or for optimal switching surface definitions. In addition, these benefits are attained using a single switching surface equation. An illustrative example is included to show the advantages of the proposed design methodology. [ABSTRACT FROM AUTHOR]

A dialkylamino-subtituted oligophenylenevinylene (OPV) derivative bearing a fullerene subunit (F–D) has been prepared. The electrochemical properties of F–Dhave been investigated by cyclic voltammetry. Whereas the first reduction is centered on the C60unit, the oxidation is centered on the dialkylamino subunit of the OPV rod. In F–D, both the OPV and the fullerene-centered fluorescence bands are quenched and this suggests the presence of photoinduced electron transfer from the amino-substituted OPV to the carbon sphere. By means of bimolecular quenching experiments, transient absorption spectral fingerprints of the radical cationic species have been detected in the VIS (670 nm) and NIR (1300–1500 nm) regions, along with the much weaker fullerene anion band at λmax= 1030 nm. Intramolecular photoinduced electron transfer occurs in the investigated dyad and a relatively long-lived charge-separated state has been detected, with a lifetime of 135 and 85 ns in toluene and benzonitrile, respectively. The longer lifetime in the less polar solvent suggests a Marcus inverted region behavior for the charge recombination process. [ABSTRACT FROM AUTHOR]

A case of fungal keratitis is presented in which corneal scrapings were obtained for microbiological studies, including morphological identification and molecular characterization of the etiologic agent. Comparative sequence analyses of the Internal Transcribed Spacer domain of 5.8S and 26S regions of nuclear rDNA showed 100% identity with different species of Alternaria and PCR-RFLP analysis of Intergenic Spacer regions revealed intraspecific variation. The combination of morphological and molecular characters resulted in the unambiguous identification of the causal agent as Alternaria alternata. Treatment with antifungals contributed to the improvement in the patient's lesions. [ABSTRACT FROM AUTHOR]

Since the discovery of C60 fullerene, carbon-based nanostructures have become one of the hottest research topics in science. During the past decade research efforts have mainly been devoted to the investigation of C60 and carbon nanotubes, although the ability of carbon to exist in different allotropic forms has provided a variety of nanoscale size shapes with fascinating properties. In this article we highlight some of the most representative examples that document the scientific progress accomplished in this field which, surprisingly, started with a serendipitous discovery. [ABSTRACT FROM AUTHOR]

Fullerene derivatives bearing a pyridine sub-unit have been prepared. Their ability to form self-assembled supramolecular structures with mono- and polytopic Zn(ii)–porphyrin receptors has been first evidenced by UV-vis studies. These supramolecular complexes are multi-component photoactive devices, in which the emission of the porphyrinic receptor is dramatically quenched by the fullerene units. This new property, resulting from the association of the different molecular sub-units, also allowed us to investigate in detail the self-assembly process using fluorescence titrations. The binding studies revealed positive cooperative effects for the assembly of the C60–pyridine derivatives with polytopic receptors as a result of intramolecular C60–C60 interactions between the different guests assembled onto the multi-Zn(ii)–porphyrin hosts. [ABSTRACT FROM AUTHOR]

A 2-pyrazolino[60]fullerene-based triad, possessing two TTF units connected with flexible long linkages, has been prepared. Fluorescence quenching was observed in polar and non-polar solvents, suggesting the existence of a through-space photoinduced charge separation process with rates faster than 3.8 × 109 s−1 and with high efficiency (>0.85). The charge separated states were confirmed by transient absorption spectra in the visible and near-IR regions. The longest lifetime of the charge separated state was found to be 230 ns in CH2Cl2 solvent. [ABSTRACT FROM AUTHOR]

ΔFosB, a stable splice variant of FosB, has been proposed to mediate persistent brain adaptation in response to several chronic perturbations, but it has not yet been considered in the context of sustained pain. Inflammatory pain induces neuronal plasticity that can result in persistent alteration of nociceptive pathways. This neuronal plasticity can partly result from changes in gene expression controlled by transcription factors. In the present study, we analyse the capacity of carrageenan-mediated inflammation to induce ΔFosB in the spinal cord. We found that hind-paw inflammation increases FosB-like immunoreactivity in the superficial layers of rat lumbar spinal cord for at least 7 days. This induction parallels mechanical hyperalgesia and is maximal in the dorsal horn of segment L4 of the spinal cord which corresponds to the primary nociceptive afferent regions from the hind paw. We identified this FosB-like signal as ΔFosB by comparing data obtained with antibodies raised against either an epitope present in both FosB and ΔFosB, or the FosB C-terminal region that is deleted in ΔFosB. The week-lasting changes in ΔFosB highlight the interest in this protein as a molecular marker of sustained pain, and suggest a role of this transcription factor in pain-related plasticity within the spinal cord. [ABSTRACT FROM AUTHOR]

Inhibitory synaptic transmission in the dorsal horn (DH) of the spinal cord plays an important role in the modulation of nociceptive messages because pharmacological blockade of spinal GABAA receptors leads to thermal and mechanical pain symptoms. Here, we show that during the development of thermal hyperalgesia and mechanical allodynia associated with inflammatory pain, synaptic inhibition mediated by GABAA receptors in lamina II of the DH was in fact markedly increased. This phenomenon was accompanied by an upregulation of the endogenous production of 5α-reduced neurosteroids, which, at the spinal level, led to a prolongation of GABAA receptor-mediated synaptic currents and to the appearance of a mixed GABA/glycine cotransmission. This increased inhibition was correlated with a selective limitation of the inflammation-induced thermal hyperalgesia, whereas mechanical allodynia remained unaffected. Our results show that peripheral inflammation activates an endogenous neurosteroid-based antinociceptive control, which discriminates between thermal and mechanical hyperalgesia. [ABSTRACT FROM AUTHOR]

The article presents an automatic system and algorithms for the classification of marble slabs into different groups in real time in production line, according to slabs quality. The system consists of a mechatronic prototype that houses all the required physical components for the acquisition of visual images of marble slabs, and computational algorithms that perform texture analysis, feature extraction, and classification of the marble surfaces. In the automated system described here, the marble slabs in the production line pass under a change-coupled device color video camera, located perpendicularly to the slab plane, which obtains the color image for the entire slab.

Purpose – This paper aims to present the results of a research project that the Institute for Prospective Technology Studies commissioned to research the possible effects of information and communication technologies (ICT) on a set of environmental indicators in 2020.Design/methodology/approach – The project adopted an innovative methodology combining qualitative scenario-building and quantitative modelling.Findings – The general conclusion was that the impact of ICT is roughly between -20 and +30 percent. Therefore there are significant opportunities for improving environmental sustainability through ICTs, which can rationalise energy management in housing (or facilities), make passenger and freight transport more efficient, and enable a product-to-service shift across the economy.Originality/value – The impact of ICT should accordingly be taken into account by environmental policies in order to ensure that ICT applications make a positive contribution to environmental outcomes, and, at the same time, to suppress rebound effects. [ABSTRACT FROM AUTHOR]

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), also known as Apo-2 ligand (Apo2L), is a member of the TNF cytokine superfamily. TRAIL has been widely studied as a novel strategy for tumor elimination, as cancer cells overexpress TRAIL death receptors, inducing apoptosis and inhibiting blood vessel formation. However, cancer stem cells (CSCs), which are the main culprits responsible for therapy resistance and cancer remission, can easily develop evasion mechanisms for TRAIL apoptosis. By further modifying their properties, they take advantage of this molecule to improve survival and angiogenesis. The molecular mechanisms that CSCs use for TRAIL resistance and angiogenesis development are not well elucidated. Recent research has shown that proteins and transcription factors from the cell cycle, survival, and invasion pathways are involved. This review summarizes the main mechanism of cell adaption by TRAIL to promote response angiogenic or pro-angiogenic intermediates that facilitate TRAIL resistance regulation and cancer progression by CSCs and novel strategies to induce apoptosis. [ABSTRACT FROM AUTHOR]

No abstract available Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Mixtures of an appropriate carboxylic acid and n-butylstannoic acid constitute modular gelation systems, in which the formation of a well-defined ‘tin-drum’ nanocluster subsequently underpins the hierarchical assembly of nanostructured fibres, which form self-supporting gel-phase networks in organic solvents. [ABSTRACT FROM AUTHOR]

A new methodology for the classification of images of marble surfaces is described according to visual quality parameters based on multiresolution decomposition with wavelets. Experimental results show that the three marble categories considered can be easily separated with the proposed method. [ABSTRACT FROM AUTHOR]