950 resultados para Hudson, Damián


Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Our aim was to develop an age-appropriate measure of early manifestations of aggression. We constructed a questionnaire about normative developmental milestones into which a set of items measuring infants’ use of physical force against people and expressed anger were included. These items comprise the Cardiff Infant Contentiousness Scale (CICS). Evidence for the reliability and validity of the CICS is provided from analyses of a sample of N5310 British infants, assessed at a mean age of 6 months as part of a larger longitudinal study of the development of aggression. The informants’ CICS ratings demonstrated reasonable levels of internal consistency and interrater agreement. Informants’ ratings were validated by observations of infants’ distress in response to restraint in a car seat. Longitudinal analyses revealed that contentiousness was stable over time and that contentiousness at 6 months predicted infants’ later use of force with peers. When used in the company of other methods, the simple four-item CICS scale could serve as a useful screen for early manifestations of aggressiveness in human infants.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Standard English need not be a matter of prescriptivism or any attempt to ‘create’ a particular standard, but, rather, can be a matter of observation of actual linguistic behaviour. For Hudson (2000), standard English is the kind of English which is written in published work, which is spoken in situations where published writing is most influential – especially in university level education and so in post-university professions – and which is spoken ‘natively’ at home by the ‘professional class’, i.e. people who are most influenced by published writing. In the papers in Bex and Watts (eds, 1999), it is recurrently claimed that, when speaking English, what the ‘social group with highest degree of power, wealth or prestige’ or more neutrally ‘educated people’ or ‘socially admired people’ speak is the variety known as ‘standard English’. However, ‘standard English’ may also mean that shared aspect of English which makes global communication possible. This latter perspective allows for two meanings of ‘standard’: it may refer both to an idealised set of shared features, and also to different sets of national features, reflecting different demographic and political histories and language influences. The methodology adopted in the International Corpus of English (henceforth ICE – cf. Greenbaum, 1996) enables us to observe and investigate each set of features, showing what everybody shares and also what makes each national variety of English different.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Responses evoked in muscle sympathetic nerve activity (MSNA) by systemic hypoxia have received relatively little attention. Moreover, MSNA is generally identified from firing characteristics in fibres supplying whole limbs: their actual destination is not determined. We aimed to address these limitations by using a novel preparation of spinotrapezius muscle in anaesthetised rats. By using focal recording electrodes, multi-unit and discriminated single unit activity were recorded from the surface of arterial vessels. This had cardiac- and respiratory-related activities expected of MSNA, and was increased by baroreceptor unloading, decreased by baroreceptor stimulation and abolished by autonomic ganglion blockade. Progressive, graded hypoxia (breathing sequentially 12, 10, 8% O2 for 2 min each) evoked graded increases in MSNA. In single units, mean firing frequency increased from 0.2 ± 0.04 in 21% O2 to 0.62 ± 0.14 Hz in 8% O2, while instantaneous frequencies ranged from 0.04–6 Hz in 21% O2 to 0.09–20 Hz in 8% O2. Concomitantly, arterial pressure (ABP), fell and heart rate (HR) and respiratory frequency (RF) increased progressively, while spinotrapezius vascular resistance (SVR) decreased (Spinotrapezius blood flow/ABP), indicating muscle vasodilatation. During 8% O2 for 10 min, the falls in ABP and SVR were maintained, but RF, HR and MSNA waned towards baselines from the second to the tenth minute. Thus, we directly show that MSNA increases during systemic hypoxia to an extent that is mainly determined by the increases in peripheral chemoreceptor stimulation and respiratory drive, but its vasoconstrictor effects on muscle vasculature are largely blunted by local dilator influences, despite high instantaneous frequencies in single fibres.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The quality of life of the person confronting the end stages of their life may be severely compromised without the support of family caregivers. Indeed, most people requiring palliative care would not be able to fulfill their preferences, such as care at home, without significant family caregiver input. As a consequence, health services are mandated to support the family alongside the person diagnosed with a life-threatening illness. In short, palliative care is supposed to be family centred. However, the quality and type of support made available to family caregivers has been questioned. The purpose of this review is to outline a succinct and empirically informed account of family caregiving within the context of palliative care and to propose an agenda for the future. The appraisal is underpinned by several systematic reviews, and other seminal publications from the last decade.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Observations of extreme ultraviolet (EUV) emission from an X-class solar flare that occurred on 2011 February 15 at 01: 44 UT are presented, obtained using the EUV Variability Experiment (EVE) on board the Solar Dynamics Observatory. The complete EVE spectral range covers the free-bound continua of H I (Lyman continuum), He I, and He II, with recombination edges at 91.2, 50.4, and 22.8 nm, respectively. By fitting the wavelength ranges blueward of each recombination edge with an exponential function, light curves of each of the integrated continua were generated over the course of the flare, as was emission from the free-free continuum (6.5-37 nm). The He II 30.4 nm and Ly alpha 121.6 nm lines, and soft X-ray (SXR; 0.1-0.8 nm) emission from GOES are also included for comparison. Each free-bound continuum was found to have a rapid rise phase at the flare onset similar to that seen in the 25-50 keV light curves from RHESSI, suggesting that they were formed by recombination with free electrons in the chromosphere. However, the free-free emission exhibited a slower rise phase seen also in the SXR emission from GOES, implying a predominantly coronal origin. By integrating over the entire flare the total energy emitted via each process was determined. We find that the flare energy in the EVE spectral range amounts to at most a few percent of the total flare energy, but EVE gives us a first comprehensive look at these diagnostically important continuum components.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Two species of Osmundea Stackhouse (Rhodomelaceae, Rhodophyta) that occur in Atlantic Europe have been confused under the names Osmundea ramosissima (Oeder) Athanasiadis and Osmundea truncata (Kutzing) Nam et Maggs, regarded until now as a synonym of O. ramosissima, An epitype from its type locality (Stavanger, Norway) is selected for Osmundea ramosissima Athanasiadis, recognized here as a valid name for Fucus ramosissimus Oeder, nom. illeg. Details of vegetative and reproductive morphology of O. ramosissima are reported, based on material from France, the British Isles, and Helgoland. Osmundea ramosissima resembles other species of Osmundea in its vegetative axial segments with two pericentral cells and one trichoblast, spermatangial development from apical and epidermal cells (filament type), the formation of five pericentral cells in the procarp-bearing segment of the female trichoblast, and tetrasporangial production from random epidermal cells. Among the species of Osmundea, O. ramosissima is most similar to O. truncata. Both species have discoid holdfasts, secondary pit connections between epidermal cells, and cup-shaped spermatangial pits. They differ in that: (a) O. ramosissima lacks lenticular wail thickenings and refractive needle-like inclusions in medullary cells, both of which are present in O. truncata; (b) O. ramosissima has branched spermatangial filaments that terminate in a cluster of several cells, whereas in O. truncata the unbranched spermatangial filaments have a single large terminal sterile cell; and (c) cystocarps of O. ramosissima lack protuberant ostioles but ostioles are remarkably protuberant in o. truncata. Phylogenetic analyses of rbcL sequences of Laurencia obtusa (Hudson) Lamouroux and all five Atlantic European species of Osmundea, including the type species, strongly support the generic status of Osmundea. Osmundea ramosissima and O. truncata are closely related (5.2% sequence divergence) and form a well-supported clade sister to a clade consisting of O. pinnatifida (Hudson) Stack-house, O. osmunda Stackhouse and O. hybrida (A. P. de Candolle) Nam. The formation of secondary pit connections between epidermal cells is a synapomorphy for the O. ramosissima + O. truncata clade. The close relationship between species with cup-shaped spermatangial pits (Osmundea hybrida) and urn-shaped pits (Osmundea pinnatifida and Osmundea osmunda) shows that spermatangial pit shape is not an important phylogenetic character. Parsimony analysis of a morphological data set also supports the genus Osmundea but conflicts with the molecular trees in infrageneric relationships, placing O. hybrida basal within the Osmundea clade and grouping O. osmunda and O. pinnatifida but not O. truncata and O. ramosissima. A key to Osmundea species is presented.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Vegetative and reproductive development of some European and Californian species of Laurencia Lamouroux (Ceramiales, Rhodophyta), L. obtusa (Hudson) Lamouroux, L. spectabilis Postels et Ruprecht, L. crispa Hollenberg, L. osmunda (S.G. Gmelin) Maggs et Hommersand, L. pinnatifida (Hudson) Lamouroux and L. truncata Kutzing, is investigated on the basis of liquid-preserved and herbarium specimens. The latter five species share several features, but they differ distinctly from L. obtusa, the lectotype of the genus, in essential anatomical characters of vegetative and male reproductive structures and tetrasporangial development. In these five species each vegetative axial segment produces two rather than four pericentral cells, and spermatangial branches (filaments) are produced in apical pits of branchlets from apical and epidermal cells rather than from trichoblasts arising from axial cells. The spermatangial branches are usually branched alternately and usually terminate in a cluster of several large sterile vesicular cells, rather than being branched dichotomously and terminating in a single, or occasionally a row of two, large sterile vesicular cells as in L. obtusa. Apical spermatangial pits of fertile male branchlets (except for those in L. truncata) are pocket- (or urn)-shaped, with an ostiole-like upper opening, rather than cup- (or bowl)-shaped. In these five species tetrasporangia are produced laterally from random epidermal cells rather than abaxially from particular pericentral cells (the third and fourth ones) as in L. obtusa, and the two presporangial cover cells are aligned parallel rather than transverse to the stichidial axis in surface view. These important differences strongly suggest that L. spectabilis, L. crispa, L. osmunda, L. pinnatifida and L. truncata occupy a phylogenetically different position from L. obtusa, and lead to the conclusion that the genus Osmundea Stackhouse, which was based on 0. expansa Stackhouse, nom. illeg. (= Laurencia osmunda) and which has been a nomen rejiciendum as an earlier facultative synonym of Laurencia, should be resurrected. Emendations of the generic criteria of Laurencia and Osmundea are proposed here, and relevant nomenclatural changes for several Laurencia species are also included.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The chromosome number of Gracilaria verrucosa (Hudson) Papenfuss was estimated in numerous individuals from different populations of the Cape Gris-Nez area of Northern France. To optimize estimates and to minimize counting errors, several counts were made on the same nucleus and in different nuclei of the same individual. The haploid chromosome number was estimated in vegetative gametophytic cells and tetrasporocytic cells; the diploid number was estimated from tetrasporophytic vegetative cells. The basic haploid number was n = 17 +/- 1, whereas all other Gracilaria species for which chromosome numbers are available are reported to have n = 24. These include populations of G. verrucosa from Norway and Wales that have previously been shown to be conspecific with the Cape Gris-Nez populations by comparison of plastid DNA data. G. verrucosa is therefore one of the few red algae for which populations with different chromosome numbers are known.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We have carried out a 29-state R-matrix calculation in order to calculate collision strengths and effective collision strengths for the electron impact excitation of S III. The recently developed parallel RMATRX II suite of codes have been used, which perform the calculation in intermediate coupling. Collision strengths have been generated over an electron energy range of 0-12 Ryd, and effective collision strength data have been calculated from these at electron temperatures in the range 1000-100,000 K. Results are here presented for the fine-structure transitions between the ground-state configurations of 3s(2)3p(2) P-3(0,1,2), D-1(2), and S-1(0), and the values given resolve a discrepancy between two previous R-matrix calculations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

When it is difficult to develop selective ligands within a family of related G-protein-coupled receptors (GPCRs), chemically engineered receptors activated solely by synthetic ligands (RASSLs) are useful alternatives for probing receptor function. In the present work, we explored whether a RASSL of the free fatty acid receptor 2 (FFA2) could be developed on the basis of pharmacological variation between species orthologs. For this, bovine FFA2 was characterized, revealing distinct ligand selectivity compared with human FFA2. Homology modeling and mutational analysis demonstrated a single mutation in human FFA2 of C4.57G resulted in a human FFA2 receptor with ligand selectivity similar to the bovine receptor. This was exploited to generate human FFA2-RASSL by the addition of a second mutation at a known orthosteric ligand interaction site, H6.55Q. The resulting FFA2-RASSL displayed a >100-fold loss of activity to endogenous ligands, while responding to the distinct ligand sorbic acid with pEC(50) values for inhibition of cAMP, 5.83 ± 0.11; Ca(2+) mobilization, 4.63 ± 0.05; ERK phosphorylation, 5.61 ± 0.06; and dynamic mass redistribution, 5.35 ± 0.06. This FFA2-RASSL will be useful in future studies on this receptor and demonstrates that exploitation of pharmacological variation between species orthologs is a powerful method to generate novel chemically engineered GPCRs.-Hudson, B. D., Christiansen, E., Tikhonova, I. G., Grundmann, M., Kostenis, E., Adams, D. R., Ulven, T., Milligan, G. Chemically engineering ligand selectivity at the free fatty acid receptor 2 based on pharmacological variation between species orthologs.