On the line geometry of rigid-body inertia

© 2014, Springer-Verlag Wien. In this work, several classical ideas concerning the geometry of the inertia of a rigid body are revisited. This is done using a modern approach to screw theory. A screw, or more precisely a twist, is viewed as an element of the Lie algebra to the group of proper rigid-body displacements. Various moments of inertia, about lines, planes and points are considered as geometrical objects resulting from least-squares problems. This allows relations between the various inertias to be found quite simply. A brief review of classical line geometry is given; this includes an outline of the theory of the linear line complex and a brief introduction to quadratic line complexes. These are related to the geometry of the inertia of an arbitrary rigid body. Several classical problems concerning the mechanics of rigid bodies subject to impulsive wrenches are reviewed. We are able to correct a small error in Ball’s seminal treatise. The notion of spatial percussion axes is introduced, and these are used to solve a problem concerning the diagonalisation of the mass matrix of a two-joint robot

Temporality in Schizophrenia

Introdução: A temporalidade é um elemento essencial e organizador da vivência do ser. É um elemento fundamental na coerência do self. Apesar da sua importância, é um tema relativamente pouco investigado, particularmente na esquizofrenia, onde tem sido sugerido que alterações da vivência do tempo podem ser fenómenos nucleares da psicopatologia na esquizofrenia. Objetivo: Com este trabalho pretende-se compreender de que forma as alterações na temporalidade podem estar relacionadas com a psicopatologia na esquizofrenia. Métodos: Foi efetuada uma revisão seletiva da literatura a partir da base de dados PubMed a partir do ano 2000, e posteriormente em textos clássicos de psicopatologia. Resultados e Conclusões: São distinguidos os constructos de tempo, tempo vivido e temporalidade. São descritas evidências e formuladas hipóteses da forma como as alterações da vivência do tempo poderão afetar os indivíduos com esquizofrenia. É apresentado o processo de síntese constitutiva de protensão-impressão-retenção, essencial à vivência do tempo implícito. Por fim, é demonstrado como uma falha neste processo pode afetar a vivência temporal da pessoa com esquizofrenia.info:eu-repo/semantics/publishedVersio

Efeitos de Anestésico Local no Tempo Entre Bólus e na Duração do Trabalho de Parto em Patient-Controlled Epidural Analgesia: Estudo Prospectivo de Dois Regimes de Doses Ultra-Baixas com Ropivacaina e Sufentanil

BACKGROUND: Patient-controlled epidural analgesia with low concentrations of anesthetics is effective in reducing labor pain. The aim of this study was to assess and compare two ultra-low dose regimens of ropivacaine and sufentanil (0.1% ropivacaine plus 0.5 μg.ml-1 sufentanil vs. 0.06% ropivacaine plus 0.5 μg.ml-1 sufentanil) on the intervals between boluses and the duration of labor. MATERIAL AND METHODS: In this non-randomized prospective study, conducted between January and July 2010, two groups of parturients received patient-controlled epidural analgesia: Group I (n = 58; 1 mg.ml-1 ropivacaine + 0.5 μg.ml-1 sufentanil) and Group II (n = 57; 0.6 mg.ml-1 ropivacaine + 0.5 μg.ml-1 sufentanil). Rescue doses of ropivacaine at the concentration of the assigned group without sufentanil were administered as necessary. Pain, local anesthetic requirements, neuraxial blockade characteristics, labor and neonatal outcomes, and maternal satisfaction were recorded. RESULTS: The ropivacaine dose was greater in Group I (9.5 [7.7-12.7] mg.h-1 vs. 6.1 [5.1-9.8 mg.h-1], p < 0.001). A time increase between each bolus was observed in Group I (beta = 32.61 min, 95% CI [25.39; 39.82], p < 0.001), whereas a time decrease was observed in Group II (beta = -1.40 min, 95% CI [-2.44; -0.36], p = 0.009). The duration of the second stage of labor in Group I was significantly longer than that in Group II (78 min vs. 65 min, p < 0.001). CONCLUSIONS: Parturients receiving 0.06% ropivacaine exhibited less evidence of cumulative effects and exhibited faster second stage progression than those who received 0.1% ropivacaine

Abdominal Pain as the First Manifestation of a Systemic Disease

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Vinculação da Mulher como Preditor da Dor Durante o Parto e Após o Nascimento: um Estudo Observacional Prospectivo

INTRODUCTION: Labour is considered to be one of the most painful and significant experiences in a woman's life. The aim of this study was to examine whether women's attachment style is a predictor of the pain experienced throughout labour and post-delivery. MATERIAL AND METHODS:Thirty-two pregnant women were assessed during the third trimester of pregnancy and during labour. Adult attachment was assessed with the Adult Attachment Scale ' Revised. The perceived intensity of labour pain was measured using a visual analogue scale for pain in the early stage of labour, throughout labour and post-delivery. RESULTS:Women with an insecure attachment style reported more pain at 3 cm of cervical dilatation (p < 0.05), before the administration of analgesia (p < 0.01) and post-delivery (p < 0.05) than those securely attached. In multivariate models, attachment style was a significant predictor of labour pain at 3 cm of cervical dilatation and before the first administration of analgesia but not of the perceived pain post-delivery. DISCUSSION: These findings confirm that labour pain is influenced by relevant psychological factors and suggest that a woman's attachment style may be a risk factor for greater pain during labour. CONCLUSION:Future studies in the context of obstetric pain may consider the attachment style as an indicator of individual differences in the pain response during labour. This may have important implications in anaesthesiology and to promote a relevant shift in institutional practices and therapeutic procedures

Genetic diversity of Alentejano and Iberian breeds assessed by polymorphisms of major genes

Alentejano and Iberian breeds are biogeographically located in the southwest of the Iberian Peninsula. These breeds shared a set of common characteristics. Both are phenotypically very similar showing a low growth rate and a high intramuscular fat content and are reared under extensive systems in open range fields. The aim of the current study, carried out within the framework of the TREASURE project, intends to characterize of the genetic diversity of Alentejano and Iberian breeds using the genotyping data of 32 polymorphisms located on 26 major genes. These polymorphisms were genotyped in a total of 950 animals belonging to Alentejano, Iberian and 18 additional European breeds. The low mean values of observed (Ho) and expected (Hs) heterozygosity and FIS point out a low genetic diversity in the analyzed breeds. The genetic distances estimated using Ds and FST revealed values were close to 0 (0.005 and 0.030, respectively), suggesting that these breeds are genetically similar. The population structure analyzed with multivariate methods such as Discriminant Analysis of Principal Component and admixture analyses showed that both breeds were grouped within the same cluster. These results are supported by other authors based on mitochondrial sequences who reported short genetic distances between these breeds. Although complementary analyses using a larger number of markers should be performed, the results of the current analyses support the hypothesis of Alentejano and Iberian could be different strains of the same breed

Renal Artery Angioplasty

Efectuámos angioplastia transiuminal percutânea (ATP) da artéria renal em 59 doentes hipertensos e houve benefício inicial na tensão arterial em 91,5% e tardio em 79,6%. Obtivemos melhores resultados nas lesões unilaterais (81,4%) do que nas bilaterais (72,7%); nas lesões fora do ostium (82,5%) do que nas do ostium (7 1,4%); nas lesões de origem fibromuscular (88,9%) do que nas de origem aterosclerótica(75%); e nos doentes com idade igual ou inferior a 55 anos (84,8%) do que em doentes com idade superior (71,4%). Estas diferenças não foram contudo significativas. Os bons resultados da ATP da artéria renal na hipertensão renovascular levam-nos a considerar esta forma de intervenção como uma alternativa do seu tratamento

Horizontal patterns of water temperature and salinity in an estuarine tidal channel: Ria de Aveiro

This work presents results from two complementary and interconnected approaches to study water temperature and salinity patterns in an estuarine tidal channel. This channel is one of the four main branches of the Ria de Aveiro, a shallow lagoon located in the Northwest coast of the Iberian Peninsula. Longitudinal and cross-sectional fields of water temperature and salinity were determined by spatial interpolation of field measurements. A numerical model (Mohid) was used in a 2D depth-integrated mode in order to compute water temperature and salinity patterns. The main purpose of this work was to determine the horizontal patterns of water temperature and salinity in the study area, evaluating the effects of the main forcing factors. The field results were depth-integrated and compared to numerical model results. These results obtained using extreme tidal and river runoff forcing, are also presented. The field results reveal that, when the river flow is weak, the tidal intrusion is the main forcing mechanism, generating saline and thermal fronts which migrate with the neap/spring tidal cycle. When the river flow increases, the influence of the freshwater extends almost as far as the mouth of the lagoon and vertical stratification is established. Results of numerical modelling reveal that the implemented model reproduces quite well the observed horizontal patterns. The model was also used to study the hydrology of the study area under extreme forcing conditions. When the model is forced with a low river flow (1 m3 s−1) the results confirm that the hydrology is tidally dominated. When the model is forced with a high river flow (1,000 m3 s−1) the hydrology is dominated by freshwater, as would be expected in such an area

Component digestibility of lupin (Lupinus angustifolius) and pea (Pisum sativum) seeds and effects on the small intestine and body organs in anastomosed and intact growing pigs.

Thirty-six male growing pigs were used to compare the component digestibility of legume seeds and the impact of diets and ileo-rectal anastomosis (IRA) on the morphology and enzyme activities of intestinal mucosa. The pigs were fed a control (C) diet based on casein or a diet in which 60% of crude protein (CP) was supplied by blue lupin (Lupinus angustifolius) (L) or pea (Pisum sativum) (P) seeds. Coefficient of total tract apparent digestibility (CTTAD) of organic matter (OM), CP and gross energy (GE) was lower in the L diet compared to the control diet. The pea-based diet presented intermediate CTTAD values of OM and GE. Coefficient of ileal apparent digestibility (CIAD) of OM and GE was lower in the legume-containing diets than with C. No significant differences were found for the CIAD of CP There was a significant interaction between diet and IRA for villus height in the jejunum and crypt width in the ileum. Duodenal and jejunal crypt width was lower in the pigs fed the legume-containing diets compared to controls. The diet influenced the specific activity of most intestinal enzymes at various sites along the small intestine. Anastomosed pigs had higher spleen and small intestine weights and lower large intestine weights as compared to intact pigs. IRA influenced intestinal villus and crypt architecture but it had no significant effect on the activities of intestinal enzymes. (Résumé d'auteur

The influence of muscles activation on the dynamical behaviour of the tympano-ossicular system of the middle ear

The human ear is a complex biomechanical system and is divided into three parts: outer, middle and inner ear. The middle ear is formed by ossicles (malleus, incus and stapes), ligaments, muscles and tendons, which transfers sound vibrations from the eardrum to the inner ear, linking with mastoid and Eustachian tube. In this work, a finite element modelling of the tympano-ossicular system of the middle ear was developed. A dynamic study based on a structural response to harmonic vibrations, for a sound pressure level (SPL) of 110, 120 and 130 dB SPL applied in the eardrum, is presented. The connection between the ossicles is made using a contact formulation. The model includes the different ligaments considering its hyperelastic behaviour. The activation of the muscles is based on the constitutive model proposed by previous work. The harmonic responses of displacement and pressure obtained on the stapes footplate, for a frequency range between 100 Hz and 10 kHz, are obtained simulating the muscle activation. The results are compared considering the passive and active states. The results are discussed and they are in accordance with audiological data published with reference to the effects of the middle ear muscles contraction