978 resultados para propagating in the slant path


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Mutualisms such as the figfig wasp mutualism are generally exploited by parasites. We demonstrate that amongst nonpollinating fig wasps (NPFWs) parasitic on Ficus citrifolia, a species of Idarnes galls flowers and another species feeds on galls induced by other wasps killing their larvae. The galling wasp inserts its ovipositor through the fig wall into the fig cavity. The ovipositor then follows a sinuous path and is introduced through the stigma and style of the flower. The egg is deposited between the integument and nucellus, in the exact location where the pollinating mutualistic wasp would have laid its egg. Gall induction is a complex process. In contrast, the path followed by the ovipositor of the other species is straightforward: attacking a larva within a developed gall poses different constraints. Shifts in feeding regime have occurred repeatedly in NPFWs. Monitoring traits associated with such repeated evolutionary shifts may help understand underlying functional constraints. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 114122.

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This study's purpose was to identify the therapeutic journey of families seeking health care for their children with respiratory diseases. This qualitative study had the participation of parents of children younger than five years old who were hospitalized with respiratory diseases. Path mapping was used as an instrument to collect data, which was analyzed through thematic analysis. The finding indicate that families sought the health services as soon as they perceived symptoms and had access to medical care, however such care was not decisive in resolving their health issues. Even though the families returned to the service at least another three times, the children had to be hospitalized. The attributes of primary health care were not observed in the public health services, while therapeutic encounters had no practical success.

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The photophysics of the 1-nitronaphthalene molecular system, after the absorption transition to the first singlet excited state, is theoretically studied for investigating the ultrafast multiplicity change to the triplet manifold. The consecutive transient absorption spectra experimentally observed in this molecular system are also studied. To identify the electronic states involved in the nonradiative decay, the minimum energy path of the first singlet excited state is obtained using the complete active space self-consistent field//configurational second-order perturbation approach. A near degeneracy region was found between the first singlet and the second triplet excited states with large spin-orbit coupling between them. The intersystem crossing rate was also evaluated. To support the proposed deactivation model the transient absorption spectra observed in the experiments were also considered. For this, computer simulations using sequential quantum mechanic-molecular mechanic methodology was used to consider the solvent effect in the ground and excited states for proper comparison with the experimental results. The absorption transitions from the second triplet excited state in the relaxed geometry permit to describe the transient absorption band experimentally observed around 200 fs after the absorption transition. This indicates that the T-2 electronic state is populated through the intersystem crossing presented here. The two transient absorption bands experimentally observed between 2 and 45 ps after the absorption transition are described here as the T-1 -> T-3 and T-1 -> T-5 transitions, supporting that the intermediate triplet state (T-2) decays by internal conversion to T-1. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4738757]

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We construct analytical and numerical vortex solutions for an extended Skyrme-Faddeev model in a (3 + 1) dimensional Minkowski space-time. The extension is obtained by adding to the Lagrangian a quartic term, which is the square of the kinetic term, and a potential which breaks the SO(3) symmetry down to SO(2). The construction makes use of an ansatz, invariant under the joint action of the internal SO(2) and three commuting U(1) subgroups of the Poincare group, and which reduces the equations of motion to an ordinary differential equation for a profile function depending on the distance to the x(3) axis. The vortices have finite energy per unit length, and have waves propagating along them with the speed of light. The analytical vortices are obtained for a special choice of potentials, and the numerical ones are constructed using the successive over relaxation method for more general potentials. The spectrum of solutions is analyzed in detail, especially its dependence upon special combinations of coupling constants.

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[EN] The need for stronger credentialing in the field of sports is recommended because of the complex issues modern sports face. A brief overview of the development of professional credentials/licensure is provided to set the rationale for the need for accreditation in the field of sports. The research reviewed supports the need for accreditation of both the individual professionals that serve sports and athletes and the schools and institutions as well. This research points to the similar developmental path that other licensed/credentialed professions have followed leading up to their regulation. Accreditation by the International association is offered as an answer to this need for certification.

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Abstract In this study structural and finite strain data are used to explore the tectonic evolution and the exhumation history of the Chilean accretionary wedge. The Chilean accretionary wedge is part of a Late Paleozoic subduction complex that developed during subduction of the Pacific plate underneath South America. The wedge is commonly subdivided into a structurally lower Western Series and an upper Eastern Series. This study shows the progressive development of structures and finite strain from the least deformed rocks in the eastern part of the Eastern Series of the accretionary wedge to higher grade schist of the Western Series at the Pacific coast. Furthermore, this study reports finite-strain data to quantify the contribution of vertical ductile shortening to exhumation. Vertical ductile shortening is, together with erosion and normal faulting, a process that can aid the exhumation of high-pressure rocks. In the east, structures are characterized by upright chevron folds of sedimentary layering which are associated with a penetrative axial-plane foliation, S1. As the F1 folds became slightly overturned to the west, S1 was folded about recumbent open F2 folds and an S2 axial-plane foliation developed. Near the contact between the Western and Eastern Series S2 represents a prominent subhorizontal transposition foliation. Towards the structural deepest units in the west the transposition foliation became progressively flat lying. Finite-strain data as obtained by Rf/Phi and PDS analysis in metagreywacke and X-ray texture goniometry in phyllosilicate-rich rocks show a smooth and gradual increase in strain magnitude from east to west. There are no evidences for normal faulting or significant structural breaks across the contact of Eastern and Western Series. The progressive structural and strain evolution between both series can be interpreted to reflect a continuous change in the mode of accretion in the subduction wedge. Before ~320-290 Ma the rocks of the Eastern Series were frontally accreted to the Andean margin. Frontal accretion caused horizontal shortening and upright folds and axial-plane foliations developed. At ~320-290 Ma the mode of accretion changed and the rocks of the Western Series were underplated below the Andean margin. This basal accretion caused a major change in the flow field within the wedge and gave rise to vertical shortening and the development of the penetrative subhorizontal transposition foliation. To estimate the amount that vertical ductile shortening contributed to the exhumation of both units finite strain is measured. The tensor average of absolute finite strain yield Sx=1.24, Sy=0.82 and Sz=0.57 implying an average vertical shortening of ca. 43%, which was compensated by volume loss. The finite strain data of the PDS measurements allow to calculate an average volume loss of 41%. A mass balance approximates that most of the solved material stays in the wedge and is precipitated in quartz veins. The average of relative finite strain is Sx=1.65, Sy=0.89 and Sz=0.59 indicating greater vertical shortening in the structurally deeper units. A simple model which integrates velocity gradients along a vertical flow path with a steady-state wedge is used to estimate the contribution of deformation to ductile thinning of the overburden during exhumation. The results show that vertical ductile shortening contributed 15-20% to exhumation. As no large-scale normal faults have been mapped the remaining 80-85% of exhumation must be due to erosion.

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The interaction between atmosphere–land–ocean–biosphere systems plays a prominent role on the atmospheric dynamics and on the convective rainfall distribution over the West Africa monsoon area during the boreal summer. In particular, the initialization of convective systems in the Sub – Sahelian region has been directly linked to soil moisture heterogeneities identified as the major triggering, development and propagation of convective systems. The present study aims at investigating African monsoon large scale convective dynamics and rainfall diurnal cycle through an exploration of the hypothesis behind the mechanisms of a monsoon phenomenon as an emergence of a collective dynamics of many propagating convective systems. Such hypothesis is based on the existence of an internal self – regulation mechanism among the various components. To achieve these results a multiple analysis was performed based on remote sensed rainfall dataset, and global and regional modelling data for a period of 5 seasons: 2004 - 2008. Satellite rainfall data and convective occurrence variability were studied for assessing typical spatio – temporal signatures and characteristics with an emphasis to the diurnal cycle footprint. A global model and regional model simulation datasets, specifically developed for this analysis and based on Regional Atmospheric Modelling System – RAMS, have been analysed. Results from numerical model datasets highlight the evidence of a synchronization between the destabilization of the convective boundary layer and rainfall occurrence due to the solar radiation forcing through the latent heat release. This supports the conclusion that the studied interacting systems are associated with a process of mutual adjustment of rhythms. Furthermore, this rainfall internal coherence was studied in relation to the West African Heat Low pressure system, which has a prominent role in the large scale summer variability over the Mediterranean area since it is acting as one of dynamic link between sub tropical and midlatitudes variability.

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The fall of the Berlin Wall opened the way for a reform paththe transition process – which accompanied ten former Socialist countries in Central and South Eastern Europe to knock at the EU doors. By the way, at the time of the EU membership several economic and structural weaknesses remained. A tendency towards convergence between the new Member States (NMS) and the EU average income level emerged, together with a spread of inequality at the sub-regional level, mainly driven by the backwardness of the agricultural and rural areas. Several progresses were made in evaluating the policies for rural areas, but a shared definition of rurality is still missing. Numerous indicators were calculated for assessing the effectiveness of the Common Agricultural Policy and Rural Development Policy. Previous analysis on the Central and Eastern European countries found that the characteristics of the most backward areas were insufficiently addressed by the policies enacted; the low data availability and accountability at a sub-regional level, and the deficiencies in institutional planning and implementation represented an obstacle for targeting policies and payments. The next pages aim at providing a basis for understanding the connections between the peculiarities of the transition process, the current development performance of NMS and the EU role, with particular attention to the agricultural and rural areas. Applying a mixed methodological approach (multivariate statistics, non-parametric methods, spatial econometrics), this study contributes to the identification of rural areas and to the analysis of the changes occurred during the EU membership in Hungary, assessing the effect of CAP introduction and its contribution to the convergence of the Hungarian agricultural and rural. The author believes that more targeted – and therefore efficient – policies for agricultural and rural areas require a deeper knowledge of their structural and dynamic characteristics.

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Information processing and storage in the brain may be presented by the oscillations and cell assemblies. Here we address the question of how individual neurons associate together to assemble neural networks and present spontaneous electrical activity. Therefore, we dissected the neonatal brain at three different levels: acute 1-mm thick brain slice, cultured organotypic 350-µm thick brain slice and dissociated neuronal cultures. The spatio-temporal properties of neural activity were investigated by using a 60-channel Micro-electrode arrays (MEA), and the cell assemblies were studied by using a template-matching method. We find local on-propagating as well as large- scale propagating spontaneous oscillatory activity in acute slices, spontaneous network activity characterized by synchronized burst discharges in organotypic cultured slices, and autonomous bursting behaviour in dissociated neuronal cultures. Furthermore, repetitive spike patterns emerge after one week of dissociated neuronal culture and dramatically increase their numbers as well as their complexity and occurrence in the second week. Our data indicate that neurons can self-organize themselves, assembly to a neural network, present spontaneous oscillations, and emerge spatio-temporal activation patterns. The spontaneous oscillations and repetitive spike patterns may serve fundamental functions for information processing and storage in the brain.

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Coordinated patterns of electrical activity are important for the early development of sensory systems. The spatiotemporal dynamics of these early activity patterns and the role of the peripheral sensory input for their generation are essentially unknown. There are two projects in this thesis. In project1, we performed extracellular multielectrode recordings in the somatosensory cortex of postnatal day 0 to 7 rats in vivo and observed three distinct patterns of synchronized oscillatory activity. (1) Spontaneous and periphery-driven spindle bursts of 1–2 s in duration and ~10 Hz in frequency occurred approximately every 10 s. (2) Spontaneous and sensory-driven gamma oscillations of 150–300 ms duration and 30–40 Hz in frequency occurred every 10–30 s. (3) Long oscillations appeared only every ~20 min and revealed the largest amplitude (250–750 µV) and longest duration (>40 s). These three distinct patterns of early oscillatory activity differently synchronized the neonatal cortical network. Whereas spindle bursts and gamma oscillations did not propagate and synchronized a local neuronal network of 200–400 µm in diameter, long oscillations propagated with 25–30 µm/s and synchronized 600-800 µm large ensembles. All three activity patterns were triggered by sensory activation. Single electrical stimulation of the whisker pad or tactile whisker activation elicited neocortical spindle bursts and gamma activity. Long oscillations could be only evoked by repetitive sensory stimulation. The neonatal oscillatory patterns in vivo depended on NMDAreceptor-mediated synaptic transmission and gap junctional coupling. Whereas spindle bursts and gamma oscillations may represent an early functional columnar-like pattern, long oscillations may serve as a propagating activation signal consolidating these immature neuronal networks. In project2, Using voltage-sensitive dye imaging and simultaneous multi-channel extracellular recordings in the barrel cortex and somatosensory thalamus of newborn rats in vivo, we found that spontaneous and whisker stimulation induced activity patterns were restricted to functional cortical columns already at the day of birth. Spontaneous and stimulus evoked cortical activity consisted of gamma oscillations followed by spindle bursts. Spontaneous events were mainly generated in the thalamus or by spontaneous whisker movements. Our findings indicate that during early developmental stages cortical networks self-organize in ontogenetic columns via spontaneous gamma oscillations triggered by the thalamus or sensory periphery.

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The Ivrea Zone in northern Italy has been the focus of numerous petrological, geochemical and structural studies. It is commonly inferred to represent an almost complete section through the mid to lower continental crust, in which metamorphism and partial melting of the abundant metapelites was the result of magmatic underplating by a large volume of mantle-derived magma. This study concerns amphibolite and granulite facies metamorphism in the Ivrea Zone with focus on metapelites and metapsammites/metagreywackes from Val Strona di Omegna and metapelites from Val Sesia and Val Strona di Postua, with the aim to better constrain their metamorphic evolution as well as their pressure and temperature conditions via phase equilibria modelling.rnrnIn Val Strona di Omegna, the metapelites show a structural and mineralogical change from mica-schists with the common assemblage bi-mu-sill-pl-q-ilm ± liq at the lowest grades, through metatexitic migmatites (g-sill-bi-ksp-pl-q-ilm-liq) at intermediate grades, to complex diatexitic migmatites (g-sill-ru-bi-ksp-pl-q-ilm-liq) at the highest grades. Within this section several mappable isograds occur, including the first appearance of K-feldspar in the metapelites, the first appearance of orthopyroxene in the metabasites and the disappearance of prograde biotite from the metapelites. The inferred onset of partial melting in the metapelites occurs around Massiola. The prograde suprasolidus evolution of the metapelites is consistent with melting via the breakdown of first muscovite then biotite. Maximum modelled melt fractions of 30–40 % are predicted at the highest grade. The regional metamorphic field gradient in Val Strona di Omegna is constrained to range from conditions of 3.5–6.5 kbar at T = 650–730 °C to P > 9 kbar at T > 900 °C. The peak P–T estimates, particularly for granulite facies conditions, are significantly higher (around 100 °C) than those of most previous studies. In Val Sesia and Val Strona di Postua to the south the exposure is more restricted. P–T estimates for the metapelites are 750–850 °C and 5–6.5 kbar in Val Sesia and approximately 800–900 °C and 5.5–7 kbar in Val Strona di Postua. These results show similar temperatures but lower pressure than metapelites in Val Strona di Omegna. Metapelites in Val Sesia in contact with the Mafic Complex exhibit a metatexitic structure, while in Val Strona di Postua diatexitic structures occur. Further, metapelites at the contact with the Mafic Complex contain cordierite (± spinel) that overprint the regional metamorphic assemblages and are interpreted to have formed during contact metamorphism related to intrusion of the Mafic Complex. The lower pressures in the high-grade rocks in Val Sesia and Val Strona di Postua are consistent with some decompression from the regional metamorphic peak prior to the intrusion of the Mafic Complex, suggesting the rocks followed a clockwise P–T path. In contrast, the metapelites in Val Strona di Omegna, especially in the granulite facies, do not contain any cordierite or any evidence for a contact metamorphic overprint. The extrapolated granulite facies mineral isograds are cut by the rocks of the Mafic Complex to the south. Therefore, the Mafic Complex cannot have caused the regional metamorphism and it is unlikely that the Mafic Complex occurs in Val Strona di Omegna.

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The collapse of the Soviet Union at the beginning of the 1990s also meant the end of the idea of a common soviet identity incarnated in the "soviet man" and the new "historic community of the soviet people". While this idea still lives on in the generations of the 1920s to 1940s, the younger generations tend to prefer identification with family, profession, ethnic group or religion. Ms. Alexakhina set out to investigate different interethnic interaction strategies in the multi-ethnic context of the Russian Federation, with an emphasis on analysing the role of cultural and ethno-demographic characteristics of minority ethnic groups. It aimed to identify those specific patterns of interaction dynamics that have emerged in response to the political and economic transformation at present under way. The basic supposition was that the size and growth of an ethnic population are defined not only by demographic features such as fertility, mortality and net migration, but are also dependent on processes interethnic interaction and ethnic transition. The central hypothesis of the project was that the multi-ethnic and multi-cultural composition of Russia is apparently manifesting itself in the ethnic minority groups in various forms, but particularly in the form of ethnic revival and/or assimilation. The results of these complex phenomena are manifested as changes in ethnic attachments (national re-identification and language behaviour (multi-lingualism, language transition and loss of the mother tongue). The stress of the political and economic crisis has stimulated significant changes in ethnographic, social and cultural characteristics of inter-ethnic dynamics such as the rate of national re-identification, language behaviour, migration activity and the spread of mixed marriages, among both those minorities with a long history of settlement in Russia and those that were annexed during the soviet period. Patterns of language behaviour and the spread of mixed marriages were taken as the main indicators of the directions of interethnic interaction described as assimilation, ethnic revival and cultural pluralism. The first stage of the research involved a statistical analysis of census data from 1959 to 1994 in order to analyse the changing demographic composition of the largest ethnic groups of the Russian Federation. Until 1989 interethnic interaction in soviet society was distinguished by the process of russification but the political and economic transformation has stimulated the process of ethnic revival, leading to an apparent fall in the size of the Russian population due to ethnic re-identification by members of other ethnic groups who had previously identified themselves as Russian. Cross-classification of nationalities by demographic, social and cultural indicators has shown that the most important determinants of the nature of interethnic interaction are cultural factors such as religion and language affiliation. The analysis of the dynamics of language shift through the study of bilingualism and the domains of language usage for different demographic groups revealed a strong correlation between recognition of Russian as a mother tongue among some non-Russian ethnic groups and the declining size of these groups. The main conclusion from this macro-analysis of census data was the hypothesis of the growing importance of social and political factors upon ethnic succession, that ethnic identity is no longer a stable characteristic but has become dynamic in nature. In order to verify this hypothesis Ms. Alexakhina conducted a survey in four regions showing different patterns of interethnic interaction: the Karelian Republic, Buryatiya, the Nenezkii Autonomous Region and Tatarstan. These represented the west, east, north and south of the Russian Federation. Samples for the survey were prepared on the basis of census lists so as to exclude mono-Russian families in favour of mixed and ethnic-minority families. The survey confirmed the significant growth in the importance of ethnic affiliation in the everyday lives of people in the Federation following the de-centralisation of the political and economic spheres. Language was shown to be a key symbol of the consciousness of national distinction, confirmed by the fact that the process of russification has been reversed by the active mastering of the languages of titular nationalities. The results also confirmed that individual ethnic identity has ceased to be a fixed personal characteristic of one's cultural and genetic belonging, and people's social adaptation to the current political, social and economic conditions is also demonstrated in changes in individual ethnic self-identification. In general terms, the dynamic nature of national identity means that ethnic identity is at present acquiring the special features of overall social identity, for which the frequent change of priorities is an inherent feature of a person's life cycle. These are mainly linked with a multi-ethnic environment and high individual social mobility. From her results Ms. Alexakhina concludes that the development of national languages and multi-lingualism, together with the preservation of Russian as a state language, seems to be the most promising path to peaceful coexistence and the development of the national cultures of different ethnic groups within the Russian Federation.

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Postmortem examinations and magnetic resonance imaging (MRI) studies suggest involvement of the entorhinal cortex (EC) in schizophrenic psychoses. However, the extent and nature of the possible pathogenetical process underlying the observed alterations of this limbic key region for processing of multimodal sensory information remains unclear. Three-dimensional high-resolution MRI volumetry and evaluation of the regional diffusional anisotropy based on diffusion tensor imaging (DTI) were performed on the EC of 15 paranoid schizophrenic patients and 15 closely matched control subjects. In schizophrenic patients, EC volumes showed a slight, but not significant, decrease. However, the anisotropy values, expressed as inter-voxel coherences (COH), were found to be significantly decreased by 17.9% (right side) and 12.5% (left side), respectively, in schizophrenics. Reduction of entorhinal diffusional anisotropy can be hypothesized to be functionally related to disturbances in the perforant path, the principal efferent EC fiber tract supplying the limbic system with neuronal input from multimodal association centers. Combinations of different MRI modalities are a promising approach for the detection and characterization of subtle brain tissue alterations.

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In previous studies, it was shown that there is a gunshot-related transport of skin particles and microorganisms from the entrance region into the depth of the bullet path. The present study deals with the question of whether gunshots may also cause a retrograde transport of skin particles and microorganisms from the bullet exit region back into the bullet path. For this purpose, we used a composite model consisting of rectangular gelatin blocks and pig skin. The skin pieces were firmly attached to the gelatin blocks on the side where the bullet was to exit. Prior to the test shots, the outer surface of the pig skin was contaminated with a thin layer of a defined bacterial suspension. After drying the skin, test shots were fired from a distance of 10 m using cartridges calibre .38 spec. with different bullet types. Subsequent analyses showed that in all shots with full penetration of the composite model, the bullet path contained displaced skin particles and microorganisms from the skin surface at the exit site. These could be regularly detected in the distal 6-8 cm of the track, occasionally up to a distance of 18 cm from the exit hole. The distribution of skin particles and microorganisms is presented and the possible mechanism of this retrograde transport is discussed.