943 resultados para Stephen Gray


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Development of adequate diving capabilities is crucial for survival of seal pups and may depend on age and body size. We tracked the diving behavior of 20 gray seal pups during their first 3 mo at sea using satellite relay data loggers. We employed quantile analysis to track upper limits of dive duration and percentage time spent diving, and lower limits of surface intervals. When pups first left the breeding colony, extreme (ninety-fifth percentile) dive duration and percentage time spent diving were positively correlated with age, but not mass, at departure. Extreme dive durations and percentage time spent diving peaked at [Formula: see text] d of age at values comparable with those of adults, but were not sustained. Greater peaks in extreme percentage time spent diving occurred in pups that had higher initial values, were older at their peak, and were heavier at departure. Pups that were smaller and less capable divers when they left the colony improved extreme dive durations and percentage time spent diving more rapidly, once they were at sea. Minimum survival time correlated positively with departure mass. Pups that were heavier at weaning thus benefitted from being both larger and older at departure, but smaller pups faced a trade-off. While age at departure had a positive effect on early dive performance, departure mass impacted on peak percentage time spent diving and longer-term survival. We speculate that once small pups have attained a minimum degree of physiological development to support diving, they would benefit by leaving the colony when younger but larger to maximize limited fuel reserves, rather than undergoing further maturation on land away from potential food resources, because poor divers may be able to "catch up" once at sea.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Leptin is a multifunctional hormone, produced predominantly in adipocytes. It regulates energy balance through its impact on appetite and fat metabolism, and its concentration indicates the size of body fat reserves. Leptin also plays a vital role in stretch-induced surfactant production during alveolar development in the fetus. The structure, expression pattern, and role of leptin have not previously been explored in marine mammals. Phocid seals undergo cyclical changes in body composition as a result of prolonged fasting and intensive foraging bouts and experience rapid, dramatic, and repeated changes in lung volume during diving. Here, we report the tissue-specific expression pattern of leptin in these animals. This is the first demonstration of leptin expression in the lung tissue of a mature mammal, in addition to its expression in the blubber and bone marrow, in common with other animals. We propose a role for leptin in seal pulmonary surfactant production, in addition to its likely role in long-term energy balance. We identify substitutions in the phocine leptin sequence in regions normally highly conserved between widely distinct vertebrate groups, and, using a purified seal leptin antiserum, we confirm the presence of the leptin protein in gray seal lung and serum fractions. Finally, we report the substantial inadequacies of using heterologous antibodies to measure leptin in unextracted gray seal serum.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research aims to study wall paitings created by artists Newton Navarro and Dorian Gray, installed in public buildings of modern architecture, in Natal/RN from 1950 to 1970. The subject is seen by focusing on its concepts and characterization, linked to the ideia of integration of the arts and the meaning of modern mural painting in Brasil. The study presents an analyses of those paitings considering themes, techiniques and dimensions, comparing the solutions of local artists with brasilian muralist painters, particularly the work of Cândido Portinari. Registers of artistic works show a view of the inclusion of arts in modern architecture in the city

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Maapallon pohjoinen arktinen alue on monien muutoksien äärellä. Ilmaston lämpenemisestä johtuvat muutokset alueen ympäristöön luovat myös kansainvälisoikeudellisia ja -poliittisia haasteita alueen valtioille. Jäämeren rantavaltiot ovat näiden haasteiden keskipisteessä. Tämä pro gradu -tutkielma tarkastelee nimenomaan Kanadan arktisen alueen politiikkaa pääministeri Stephen Harperin aikakaudella 2006-2015. Tarkoituksena oli selvittää Kanadan arktisen politiikan lähtökohtia, painotuksia ja sitä, miksi Kanada käyttäytyy, miten se käyttäytyy arktisella alueellaan. Kanada on yksi vaikutusvaltaisimpia valtioita pohjoisella pallonpiirillä, jonka vuoksi sen politiikalla ja intresseillä alueen suhteen on suurta merkitystä. Tutkimusaineisto koostui pääministerin arktisesta alueesta pitämistä puheista vuosilta 2006-2015 eli koko pääministerikauden ajalta ja Kanadan hallinnon virallisista arktisista strategioista. Tutkimus toteutettiin tarkastelemalla pääministeri Harperin puheiden ja strategioiden diskurssikehyksiä. Diskurssikehys tarkoittaa tässä tutkimuksessa pohjimmiltaan vallankäyttöä, jolla voidaan määritellä, mihin diskurssi kytketään. Diskurssin kehystäminen luo potentiaalin tulevalle toiminnalle diskurssissa tapahtuneen asiakysymyksen määrittelyn ja kytkemisen avulla. Näin ollen diskurssikehyksiä tutkimalla pystyttiin tarkastelemaan Kanadan hallinnon poliittisia lähtökohtia ja painotuksia. Aineistosta havaittiin kuusi vuorovaikutteista diskurssikehystä. Lisäksi huomattiin selkeä ristiriita Harperin puheiden ja Kanadan virallisten arktisten asiakirjojen kehystämisen välillä. Harper painottaa puheissaan erityisesti suvereniteetin puolustusta, arktisen alueen kanadalaista läsnäoloa, arktisten luonnonvarojen hyödyntämistä taloudellisen kehityksen aikaansaamiseksi, arktisen alueen yleistä kehitystä ja Kanadan pohjoista identiteettiä. Sen sijaan Kanadan viralliset arktiset strategiat korostavat kansainvälisen yhteistyön tärkeyttä ensisijaisesti. Tutkimuksen avulla selvisi, että Kanada pyrkii lisäämään läsnäoloa arktisella alueella ja painottaa kansallisen suvereniteetin varjelemista, pyrkii kehittämään alueen hallintoa ja infrastruktuuria sekä pyrkii mahdollistamaan talouskasvua arktiselle alueelle erityisesti alueen luonnonvaroja hyödyntämällä. Samalla erityisesti Harper pyrkii tietoisesti rakentamaan kanadalaista pohjoista identiteettiä arktisen alueen politiikan perustaksi.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rezension von: Stephen Frank: E-Learning und Kompetenzentwicklung. Ein unterrichtsorientiertes didaktisches Modell. Bad Heilbrunn: Klinkhardt 2012 (220 S.; ISBN 978-3-7815-1861-2)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Uno de los aspectos más documentados a la hora de estudiar las obras de Óscar Wilde en profundidad ha sido el concepto de máscara u ocultación. Este concepto fue tratado a su vez por el propio escritor en su ensayo titulado The Truth of Masks (1891), donde analiza, entre otras cosas, la puesta en escena y los objetos que aparecen a la hora de llevar a cabo la representación de las obras de teatro de Shakespeare. Por otra parte, no es necesario señalar que Wilde es harto reconocido por su gusto por la filosofía del arte y la estética, o mejor dicho, por su afinidad y apología al arte por el arte, así como también se le asocia con la figura del dandy decandente y esteta. Precisamente ambos aspectos, tanto el de la ocultación como el de la filosofía del arte y la estética, nos servirán como ineludible punto de partida para este estudio, que, mediante el análisis cultural de sus obras más representativas, completarán la recepción actual existente de Wilde. Se verá en este estudio que una faceta indispensable del escritor recae principalmente en la aportación que realiza el artesano, en estrecha comunión con el artista, tal y como él mismo defendió en numerosos de sus ensayos-conferencias, en los que propugnaba el individualismo mediante la realización del ser, en el plano artístico. Se ha llevado a cabo por tanto, un exhaustivo análisis para profundizar aún más en la conexión que existe entre estos conceptos, y ahondando por ende en la visión del artista artesano, que justificará ese nuevo perfil consumado del escritor, a través del análisis de los objetos en sus obras, escritos e, incluso, en su propia persona, entendida ésta como creación artística. No en vano, Wilde es el escritor que nos permite retomar el sentido etimológico de la palabra ‘persona’, para descubrir que, en su origen, ésta significaba ‘máscara’, y que consiguientemente, entronca directamente con la persona del escritor, y nos hace volver a plantearnos dónde empieza o acaba la máscara y dónde su propia persona artística...

Relevância:

20.00% 20.00%

Publicador:

Resumo:

El presente estudio refleja los argumentos teóricos y propuestas en el campo de la investigación artística, que resultaron de la autoreflexión en torno a la tesis Art Realities y el proyecto artístico visual The Cloudwalkers, que el autor realizó para la obtención del grado MFA in New Media en la Danube Universität (Austria), en colaboración con el Transart Institute (E.U.A.). Es un análisis autocrítico de caso que abarca tanto la parte escrita como práctica del proyecto de titulación, del que se deriva un estudio teórico que expone posibles instrumentos y estrategias de investigación para las artes visuales.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research aims to study wall paitings created by artists Newton Navarro and Dorian Gray, installed in public buildings of modern architecture, in Natal/RN from 1950 to 1970. The subject is seen by focusing on its concepts and characterization, linked to the ideia of integration of the arts and the meaning of modern mural painting in Brasil. The study presents an analyses of those paitings considering themes, techiniques and dimensions, comparing the solutions of local artists with brasilian muralist painters, particularly the work of Cândido Portinari. Registers of artistic works show a view of the inclusion of arts in modern architecture in the city

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of my research was to explore the interplay between religion and art in James Joyce’s novel, A PORTRAIT OF THE ARTIST AS A YOUNG MAN. My aim was to trace the development of the protagonist, Stephen Dedalus by analyzing how Catholicsim is an institution that forms him, yet must reject to realize his artistic potential. I researched Joyce’s background to gain an understanding of the exilic experience on the literature. Through the exilic lens, I realized that Catholicism was the predominant influence on Stephen’s need to embark on a self-imposed exile at the end of the novel. Complicating his decision is the fact that he does not stop believing in religious constructs such as heaven and hell. In conclusion I found by following his artistic longing, and turning away from the church he is committing a sin and, as a result, damning his soul.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In questo elaborato viene proposta la traduzione di un capitolo di "The Plant", libro inedito di Stephen King. Vengono illustrati il procedimento, l'approccio alla traduzione e le sfide maggiori riscontrate nel testo originale con relativi esempi. All'inizio è presente anche un capitolo introduttivo sull'autore, con biografia, storia e trama del libro preso in questione, nonché una breve parentesi sui suoi traduttori italiani più famosi.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Snakebite is a neglected disease and serious health problem in Brazil, with most bites being caused by snakes of the genus Bothrops. Although serum therapy is the primary treatment for systemic envenomation, it is generally ineffective in neutralizing the local effects of these venoms. In this work, we examined the ability of 7,8,3'-trihydroxy-4'-methoxyisoflavone (TM), an isoflavone from Dipteryx alata, to neutralize the neurotoxicity (in mouse phrenic nerve-diaphragm preparations) and myotoxicity (assessed by light microscopy) of Bothrops jararacussu snake venom in vitro. The toxicity of TM was assessed using the Salmonella microsome assay (Ames test). Incubation with TM alone (200 μg/mL) did not alter the muscle twitch tension whereas incubation with venom (40 μg/mL) caused irreversible paralysis. Preincubation of TM (200 μg/mL) with venom attenuated the venom-induced neuromuscular blockade by 84% ± 5% (mean ± SEM; n = 4). The neuromuscular blockade caused by bothropstoxin-I (BthTX-I), the major myotoxic PLA2 of this venom, was also attenuated by TM. Histological analysis of diaphragm muscle incubated with TM showed that most fibers were preserved (only 9.2% ± 1.7% were damaged; n = 4) compared to venom alone (50.3% ± 5.4% of fibers damaged; n = 3), and preincubation of TM with venom significantly attenuated the venom-induced damage (only 17% ± 3.4% of fibers damaged; n = 3; p < 0.05 compared to venom alone). TM showed no mutagenicity in the Ames test using Salmonella strains TA98 and TA97a with (+S9) and without (-S9) metabolic activation. These findings indicate that TM is a potentially useful compound for antagonizing the neuromuscular effects (neurotoxicity and myotoxicity) of B. jararacussu venom.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Envenoming by the pitviper Bothrops jararacussu produces cardiovascular alterations, including coagulopathy, systemic hemorrhage, hypotension, circulatory shock and renal failure. In this work, we examined the activity of this venom in rat isolated right atria. Incubation with venom (0.025, 0.05, 0.1 and 0.2mg/ml) caused concentration-dependent muscle contracture that was not reversed by washing. Muscle damage was seen histologically and confirmed by quantification of creatine kinase-MB (CK-MB) release. Heating and preincubation of venom with p-bromophenacyl bromide (a phospholipase A2 inhibitor) abolished the venom-induced contracture and muscle damage. In contrast, indomethacin, a non-selective inhibitor of cyclooxygenase, and verapamil, a voltage-gated Ca(2+) channel blocker, did not affect the responses to venom. Preincubation of venom with Bothrops or Bothrops/Crotalus antivenom or the addition of antivenom soon after venom attenuated the venom-induced changes in atrial function and tissue damage. These results indicate that B. jararacussu venom adversely affected rat atrial contractile activity and muscle organization through the action of venom PLA2; these venom-induced alterations were attenuated by antivenom.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Scorpion stings account for most envenomations by venomous animals in Brazil. A retrospective study (1994-2011) of the clinical consequences of Tityus scorpion stings in 1327 patients treated at a university hospital in Campinas, southeastern Brazil, is reported. The clinical classification, based on outcome, was: dry sting (no envenoming), class I (only local manifestations), class II (systemic manifestations), class III (life-threatening manifestations, such as shock and/or cardiac failure requiring inotropic/vasopressor agents, and/or respiratory failure), and fatal. The median patient age was 27 years (interquartile interval = 15-42 years). Scorpions were brought for identification in 47.2% of cases (Tityus bahiensis 27.7%; Tityus serrulatus 19.5%). Sting severity was classified and each accounted for the following percentage of cases: dry stings - 3.4%, class I - 79.6%, class II - 15.1%, class III - 1.8% and fatal - 0.1%. Pain was the primary local manifestation (95.5%). Systemic manifestations such as vomiting, agitation, sweating, dyspnea, bradycardia, tachycardia, tachypnea, somnolence/lethargy, cutaneous paleness, hypothermia and hypotension were detected in class II or class III + fatal groups, but were significantly more frequent in the latter group. Class III and fatal cases occurred only in children <15 years old, with scorpions being identified in 13/25 cases (T. serrulatus, n = 12; T. bahiensis, n = 1). Laboratory blood abnormalities (hyperglycemia, hypokalemia, leukocytosis, elevations in serum total CK, CK-MB and troponin T, bicarbonate consumption and an increase in base deficit and blood lactate), electrocardiographic changes (ST segment) and echocardiographic alterations (ventricular ejected fraction <54%) were frequently detected in class III patients. Seventeen patients developed pulmonary edema, 16 had cardiac failure and seven had cardiogenic shock. These results indicate that most scorpion stings involved only local manifestations, mainly pain; the greatest severity was associated with stings by T. serrulatus and in children <15 years old.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Rhinella schneideri, previously known as Bufo paracnemis, is a common toad in many regions of Brazil. Its venom exerts important cardiovascular effects on humans and other animals. Although this toad venom has been the subject of intense investigations, little is known about its neuromuscular activity. The neurotoxicity of a methanolic extract of R. schneideri venom was tested on mouse phrenic nerve-diaphragm (PND) preparations mounted for conventional twitch tension recording - in response to indirect stimulation - and for electrophysiological measurements. Venom extract (50 μg/mL) increased the muscle twitch tension in PND preparations but did not significantly alter the resting membrane potential values. Electrophysiological evaluations showed that the extract (50 μg/mL) significantly augmented the frequency of miniature end-plate potential (from 38 ± 3.5 to 88 ± 15 after 60 minutes; n = 5; p < 0.05) and quantal content (from 128 ± 13 to 272 ± 34 after five minutes; n = 5; p < 0.05). Pretreatment with ouabain (1 μg/mL) for five minutes prevented the increase in quantal content (117 ± 18 and 154 ± 33 after five and 60 minutes, respectively). These results indicate that the methanolic extract of R. schneideri venom acts primarily presynaptically to enhance neurotransmitter release in mouse phrenic-diaphragm preparations.