968 resultados para Muscles extenseurs du tronc


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A rich uppermost Miocene selachian fauna from the Alvalade Basin (represented by more than 10.000 teeth) is accounted for. It is the most modern miocene fauna of neritic habit under warm-temperate to subtropical conditions, known in the european Miocene.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Similarly to other organisms, Vertebrates changed during the Cenozoic Era. Mammals are the only ones to change quickly; their well mineralised bones and teeth are often fossilised. They are highly diverse and even isolated teeth can be identified. They are thus a good tool for establishing a biochronological framewoork. Among Mammals, Rodents with a short lifetime evolve more quickly than the large Mammals. In Europe, the first elaborated zonation was investigated by the Regional Committee on Neogene Stratigraphy and issued as the MN Zonation (Mammals Neogene) by Mein, 1976. During the following years, progress in knowledge lead to new charts. The latest one resulted from collective work (de Bruijn et al., 1992). Bîochronology gives relative data; if we desire to have numerical age estimates, we must correlate these results with radiometrie data, marine biostratigraphîcal units or the Geomagnetic Polarity Time Scale. For Europe, these results are summarised by Steininger et al. (1989-1996) and Steininger (1999). After some recents developments on MN Zonation, here is discussed the succession of Neogene small mammals Portuguese localities. Fortunately these localities are in majority inbedded in marine context. Their assigment to MN Zones is proposed and correlations with the spanish Aragonian Scale (Daams el al., 1999) are also suggested. In fact, some differences appear between Portugal and Aragonian assemblages, probably for ecological reasons. Therefore, the MN zonation is always useful for short and long distance biochronological correlations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

New data led us to revise Miocene Perissodactyla from Lisbon. Equids (Anchitherium) have been decribed by Alberdi & González (1999); we fully agree with their conclusions. On the other hand, the only Chalicotheriid cannot be clearly reported to any genus. It therefore will be left in open nomenclature Schizorheriinae ind.). The Rhinocerotids have been described in detail (1983). We could recognize now that: Protaceratherium sagicum is a synonym of P. minutum; Plesiaceratherium platyodon and Plesiaceratherium lumiarense should be ascribed to the genus Plesiaceratherium and not to Aceratherium; there are no reasons for name changes as far as the forms previously referred as Diaceratherium aurelianensis, Prosantorhinus germanicus and Hispanotherium matritensis are concerned; as the genera Dicerorhinus and Lartetotherium are distinct, Dicerorhinus (Lartetotherium) sansaniensis has to be named Lartetotherium sansaniensis; as Gaindatherium (Ïberotherium) rexmanueli cannot be reported to Gaindatherium, we therefore upgrade the subgenus Iberotherium to the genus'rank - hence the names of the concerned taxa become Iberotherium rexmanueli rexmanueli and I. rexmanueli zbyszewski; Chilotherium ibericus is but a dental variation of I. rexmanueli zbyszewski. The stratigraphic distribution and age of the Miocene Perissodactyla so far known in the Lower Tagus basin / Lisbon region are presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Discovery of a fifth metapodial of the Creodont Hyaenodontidae Hyainailouros sulzeri at Quinta da Farinheira (Chelas), near Lisbon (Portugal) in the beginning of the Middle Miocene.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Domerian sections from the Lusitanian Basin of São Pedro de Muel, Rabaçal and Tomar have provided us with more than 1100 Ostracods belonging from 18 genus and about 48 species. The faunal diversity and density of the associations decrease in space (from Tomar to Rabaçal and São Pedro de Muel) and time, with favourable environments for the proliferation of Ostracods at the lower part of the sections (Stokesi subzone) and more hostile at the upper part (Ragazzonii subzone). The Monestieri and Nitescens horizons and the Subnodosus subzone are characterized by a typical assemblage of Ostracods. The palaeoecological Ostracod indexes reveal the fluctuations of the oxygenation, temperature, depth and hydrodynamism of the water, on the different sections and on the whole platform. They display a diachronous cooling in the Lower Domerian series. In the upper part of the Middle and in the Upper Domerian, the deeper, less oxygenated and cooler waters prevent the development of the Ostracod faunas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fragmentary skeletal remains of Percoid fishes (Teleostei, Percoidei) are described from the Upper Paleocene? or Lowermost Eocene(MN7) from Silveirinha. It is suggested that they belong to some primitive Percoids which are already known in the Iberian peninsula. They bear witness of an ancient westwards extension of the geographical distribution of Percoid fishes that are common in the lower levels of the Eocene in the Douro Basin in Spain.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Several Lower and Middle Miocene localities in the Lower Tagus basin near Lisbon yielded Latidae fragmentary remnants. No really decisive character has been recognized that would allow us to state these remnants could surely be ascribed to the genus Lates Cuv. & Val., although we regard this as nearly certain. There are some differences between the Miocene latidae under study and the type species Lates niloticus L. this suggests us to report the concerned remnants to a Lates (?) sp. that could belong to a new, hitherto undescribed species. The occurrence of Lates in fluviatile or lagoonal beds in the Lower Tagus basin Miocene series is not at all surprising under a paleoeciological view point. Even less if account is taken of the presence in the same levels of Siluriforms remnants belonging to Bagridae and Ariidae, two families that are well represented in Africa. Bagrid spines have been found at Quinta das Pedreiras in association with Lates (?) sp. remnants. The Lates (?) sp. discovery in the Lower and Middle Miocene from the Lower Tagus basin results in extending to the West this genus' biogeographic distribution. It is indeed the first discovery of this genus on Europe's Atlantic coasts. No matter which was the geographic origin of these fishes, they had to migrate several hundreds of kilometers through marine waters before entering the Tagus' estuary. The association of Lates (?) sp. remnants with Siluriform ones that have an extant, broad repartition in Africa south of the Sahara points out to an African origin. These thermophyll fishes imigration along the Atlantic coasts from lberian Peninsula probably has been possible owing to a warm climatic event that allowed them to migrate ca. 5 degrees (in latitude) northwards in Burdigalian times.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A distal part of tibiotarsus from Charneca do Lumiar (Langhian, MN5) is identified as Palaeoperdix media, formerly known as Miophasianus medius. This species is thus known on a large area of the Palearctic province, from Portugal to Poland, and from the beginning of the Middle Miocene (MN 5) to the beginning of the Upper Miocene (MN9). An indeterminate, Gruid from Quinta das Pedreiras (Lower Langhian, MN4) and a few marine birds' remnants from Penedo Norte (Burdigalian) have been recognized.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This fascicle, dedicated to the Domerian (Late Pliensbachian) ammonites faunas, is the third part of the “Atlas des fossiles caractéristiques du Lias portugais“. It follows two previous publications about the Hettangian-Sinemurian and the Carixian (Lower fifty species are concisely described and illustrated. The other groups (nautilids, belemnites, brachiopods, bivalvia...) will be published afterwards. The principal objective of the “Atlas des fossiles caractéristiques du Lias portugais“ is to make the main liassic lusitanian fossils known to a wide public. It also aims to support field studies by giving a rich iconography dedicated to the lusitanian invertebrate macrofaunas. In the case of the ammonites, all the species are described and the “Atlas” can be used as an exhaustive database for biostratigraphic and paleobiogeographic studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Terminologia

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of the article is to evaluate the impact of the friction force mouse-pad in the contraction level of the forearm muscles M. extensor carpi ulnaris, M. extensor digitorum and M. extensor carpi radialis longus. A standard protocol of mouse movements was performed involving horizontal, vertical and diagonal mouse displacements drag-and-drop type. The operators were instructed to execute the protocol with their normal working speed. The movements protocol were performed by each subject (n=17) with three selected pairs mouse-pad, classified as low, medium and high friction force pairs. The mean time to execute the protocol with each mouse was ~138s. Mean values of ~13%MVE and ~17%MVE were found in the M. extensor carpi ulnaris and in the M. extensor digitorum respectively when performing the movements’ protocol. A 8.1% increase in %MVE was observed in the M. extensor digitorum and a 9.4% increase in %MVE was observed in the M. extensor carpi ulnaris when the high friction force pair was operated, relatively to the low friction force pair (p<0.05). The main preliminary conclusions of this study is that operating a high friction force mouse-pad may increase the risk to symptoms or disorders in the wrist due to an increase in the forearm muscles contraction levels, particularly during work with drawing application

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ergonomic interventions such as increased scheduled breaks or job rotation have been proposed to reduce upper limb muscle fatigue in repetitive low-load work. This review was performed to summarize and analyze the studies investigating the effect of job rotation and work-rest schemes, as well as, work pace, cycle time and duty cycle, on upper limb muscle fatigue. The effects of these work organization factors on subjective fatigue or discomfort were also analyzed. This review was based on relevant articles published in PubMed, Scopus and Web of Science. The studies included in this review were performed in humans and assessed muscle fatigue in upper limbs. 14 articles were included in the systematic review. Few studies were performed in a real work environment and the most common methods used to assess muscle fatigue were surface electromyography (EMG). No consistent results were found related to the effects of job rotation on muscle activity and subjective measurements of fatigue. Rest breaks had some positive effects, particularly in perceived discomfort. The increase in work pace reveals a higher muscular load in specific muscles. The duration of experiments and characteristics of participants appear to be the factors that most have influenced the results. Future research should be focused on the improvement of the experimental protocols and instrumentation, in order to the outcomes represent adequately the actual working conditions. Relevance to industry: Introducing more physical workload variation in low-load repetitive work is considered an effective ergonomic intervention against muscle fatigue and musculoskeletal disorders in industry. Results will be useful to identify the need of future research, which will eventually lead to the adoption of best industrial work practices according to the workers capabilities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to analyze the influence of position and pauses on muscle activity and fatigue during the task of ironing. Ten female participants performed the task of ironing in two different positions (standing and sitting) for 10 min each with a 1-min pause at the end of each task. Muscle activity and fatigue from the upper trapezium, anterior deltoid, and pectoralis major were analyzed using surface electromyography. The results showed that the positions had no significant influence on muscle activity; nevertheless, they had significant influence on muscular fatigue. In addition, the pauses were possibly beneficial in decreasing the muscle fatigue, but the results were not conclusive.