Change in the North Atlantic circulation associated with the mid-Pleistocene transition

The southwestern Iberian margin is highly sensitive to changes in the distribution of North Atlantic currents and to the position of oceanic fronts. In this work, the evolution of oceanographic parameters from 812 to 530 ka (MIS20-MIS14) is studied based on the analysis of planktonic foraminifer assemblages from site IODP-U1385 (37 degrees 34.285' N, 10 degrees 7.562' W; 2585m b.s.l.). By comparing the obtained results with published records from other North Atlantic sites between 41 and 55 degrees N, basin-wide paleoceano-graphic conditions are reconstructed. Variations of assemblages dwelling in different water masses indicate a major change in the general North Atlantic circulation during MIS16, coinciding with the definite establishment of the 100 ky cyclicity associated with the mid-Pleistocene transition. At the surface, this change consisted in the redistribution of water masses, with the subsequent thermal variation, and occurred linked to the northwestward migration of the Arctic Front (AF), and the increase in the North Atlantic Deep Water (NADW) formation with respect to previous glacials. During glacials prior to MIS16, the NADW formation was very weak, which drastically slowed down the surface circulation; the AF was at a southerly position and the North Atlantic Current (NAC) diverted southeastwards, developing steep south-north, and east-west, thermal gradients and blocking the arrival of warm water, with associated moisture, to high latitudes. During MIS16, the increase in the meridional overturning circulation, in combination with the northwestward AF shift, allowed the arrival of the NAC to subpolar latitudes, multiplying the moisture availability for ice-sheet growth, which could have worked as a positive feedback to prolong the glacials towards 100 ky cycles.info:eu-repo/semantics/publishedVersio

THE DYNAMIC SUPPORT STRUCTURE AND THE FOOT STABILITY RELATED TO RUNNING SPEED

Introduction - The alterations of the dynamic support structure in running, related to the horizontal speed increase, has been studied by several authors; Cavanagh (1989)studies the displacement of the support center and the pressure distributions; Nigg et all (1981) analyses the active and passive loader Bates (1983) study the critical variables defining the support dynamic. Simultaneously, the study of the rearfoot mobility around the horizontal axes of the subtalar joint during ground contact has been gaining in importance (Nigg et all, 1978). The above mentioned subjects are integrated in the present study for a more complete knowledge of the foot contact. Relations between the increase of running speed and respectively the variables defining the rearfoot mobility and the critical variable6 of the ground reaction forces are establish. Methods - Six sprinter of Portuguese national level carried out each of them 6 performances, barefoot, at three different speeds (Vl=3.3 7 me-I+/-0.56 ; V2=4. 37me"+/-0.37 e V,55 -44 me-I+/-0.31). The kinetic data were obtained on a force platform (Kistler 9281B, sampling frequency 1000 Hz) connected t6 the computer via A/D card (DT 2801A Data Translation). The runners speed was controlled by means of photoelectric censors that synchronized the collection of the kinetic and video images. The kinematic data was processed according to the methodology proposed by Nigg et all (1978). Results and Discussion - The obtained kinetic results are similar to those contained in the corresponding bibliographic references , in form patterns as well as in quantitative results (Cavanagh,1989 ; Nigg et a11,1981; Batee et all, 1983). Regarding the rearfoot mobility the displacement/time curves are similar to the ones presented by Nigg et all (1978) as far as barefoot runners are concerned. Significant statistical correlations (correlation coefficient, Bravais-Pearson) were ascertained showing that the running speed increase ie related to : (1) decrease of ground contact time (r=-0.96, P-ZO.01) , (2) increase of anteriorposterior speed variation (aVy) (r50.77,

Força e arquitetura muscular em sujeitos com doença arterial periférica dos membros inferiores

Introdução: São conhecidas as alterações da funcionalidade, nomeadamente na marcha e da função da bomba muscular da perna do indivíduo com doença arterial periférica (DAP), pelo que importa aos profissionais de saúde conhecer as alterações funcionais e estruturais associadas a esta condição. Objetivos: Avaliar a relação entre a arquitetura muscular (AM) do gémeo interno (GI), a produção de força dos músculos flexores plantares (MFP) e o índice de oclusão arterial, num grupo com DAP, comparativamente a um grupo controlo (sem DAP). Metodologia: Foram incluídos 25 sujeitos, 13 controlo e 12 com DAP, totalizando 15 pernas avaliadas por grupo, numa única sessão. A força dos MFP e amplitude de movimento da tibiotársica foram avaliadas por dinamometria isocinética (60º/s e 120º/s); a AM do GI por ultrassonografia e o índice tornozelo braço (ITB) por doppler. Foram avaliadas as diferenças entre os grupos com e sem DAP; No grupo com DAP, foram avaliadas as diferenças entre subgrupo com maior e menor severidade de oclusão (ITB<0,7 e ITB≥0,7); e foram estabelecidas correlações entre os dados de dinamometria isocinética com os da AM no grupo com DAP. Resultados: Comparado com o grupo controlo, os MFP do grupo DAP, apresentaram menores valores de momento de força máxima, momento de força máxima por unidade de peso corporal, trabalho total e potência média a 60º/s e 120º/s (P<0,05). Identificou-se, no grupo DAP ITB<0,7 menor momento de força máximo por unidade de peso corporal a 60º/s e 120º/s, comparativamente ao grupo DAP ITB≥0,7. Não se observaram diferenças entre grupo DAP e controlo na AM do GI, nem esta se relacionou com a força dos MFP ou alterada em função da gravidade da DAP. Conclusões: Sujeitos com DAP apresentam menor força dos MFP, que sujeitos sem DAP, que agrava com a severidade da obstrução arterial. Contudo, a AM do GI parece semelhante nos dois grupos, sem ter relação com a força muscular.Abstract: Introduction: The changes in functionality, namely gait and calf muscle pump function of the individual with peripheral arterial disease (PAD) are known, so it is important for health professionals to know the functional and structural changes associated with this condition. Objectives: To evaluate the relationship between gastrocnemius medialis (GM) muscle architecture, isokinetic plantar flexion strength and the lower-extremity arterial occlusion (ABI), in a group with PAD compared to a control group (without PAD). Methods: 25 individuals were included, 13 control and 12 with PAD, comprising 15 legs evaluated in each group, in a single session. Plantar flexion strength and ankle range of motion were evaluated by isokinetic dinamometry (60º/s e 120º/s); GM muscle architecture by ultrassonography and ABI by doppler. Diferences between groups with and without PAD were assessed; In PAD group, the diferences between subgroup with greater and lesser occlusion severity (ABI <0.7 and ABI≥0.7) were evaluated; and correlations were established between isokinetic dynamometry data with muscle architecture in the PAD group. Results: Compared with control group, plantar flexion muscles in PAD group presented a lower peak torque, peak torque to body weight, total work and average power at 60º/s and 120º/s (p<0,05). In a presence of a ABI<0,7, PAD group showed a lower plantar flexion peak torque to body weight for both 60º/s and 120º/s, compared with PAD group with a ABI>0,7. No associations between PAD patients and controls were found for GM architecture and these were not associated with plantar flexion isokinetic strength, or either with lower-extremity arterial haemodynamics. Conclusions: PAD subjects show lower plantar flexion muscle strength than control subjects, aggravated in the most severe cases of arterial obstruction. Nevertheless GM muscle architecture appears to be similar in both groups, with no association for plantar flexion strength or ABI.info:eu-repo/semantics/publishedVersio

Programa de Qualidade de Vida no Trabalho da Embrapa Florestas: documento orientador.

1 CD-ROM

The pinewood nematode, Bursaphelenchus xylophilus, in Madeira Island

The environmental conditions in Madeira Island are favorable for the presence and dissemination of the pinewood nematode (PWN), Bursaphelenchus xylophilus. Five hundred Pinus pinaster wood samples were collected in several forest areas and PWN was detected in 22.8 % of the samples. Bursaphelenchus xylophilus isolates from Madeira Island displayed the species-specific diagnostic characters. A morphological variation in the female tail terminus was detected. In most females, the tail presented a broadly rounded terminus and, occasionally, a digitate terminus with a terminal nipple-like extension resembling a mucro. PCR ITS-RFLP analysis revealed that Madeira Island isolates exhibited patterns specific to the species B. xylophilus and similar to virulent isolates. Amplified ITS regions were further sequenced and no genetic diversity was found for this genomic region among 17 Portuguese isolates (Madeira Island and Continental Portugal). Phylogenetic analysis revealed that Portuguese isolates grouped with isolates from China, Korea and one isolate from Japa

KINEMATIC ANALYSIS OF BASKETBALL SHOOTING. PRELIMINARY RESULTS

INTRODUCTION-Basketball shooting is the most important skill of the game Its teaching methodology is based on permanent adjustment of theoretical sentences of performance and individual characteristics. Development of basketball players needs talent but also technical qualities which is the reason why youngsters must know the basic principles of technique However, ball size, basket height and court dimensions are three variables which can affect the learning process of basketball shooting (Skleryk , 1985). The purpose of the present study is to analyse the effect of ball size on some mechanical parameters of free throw shooting, as performed by eight fourteen-year-old basketball players Two ball sizes were used regular size ball (613 gr weight, 74 cm perimeter) and adapted size ball (608 gr weight, 76.5 cm perimeter). Two video cameras were utilized to recover the videographic material on frontal and lateral views of shooters Three free throws of each player were digitalized and analysed with BIOSIST Based on Satern (1989), six mechanical parameters related to shooter segment were analysed on ball release (shoulder angle, elbow angle, wrist angle, hand height, linear hand velocity and hand angle) The determination of maximum elbow flexion occurring during shooting was another goal. Also, displacement of the centre of gravity and its relationship with support surface was investigated RESULTS-Mean and standard deviation of each parameter per trial digitalized were selected. Higher values of height and angle release were obtained with adapted size ball. It appears that the regular ball needs an increase of linear hand velocity in shooting Differences between intersegmental angles reveal a general tendency for the shooter to employ more force in regular-ball than in adapted-size-ball. Results show a higher flexion of elbow and a higher release elbow angle when the player shoots with a larger ball. Release angle wrist appears less with regular ball which indicates that more work is produced by the shooting hand with adapted-size-ball. Displacement of centre of gravity on the vertical plan was the most significant difference. The difference between initial instant of shooting and the ball release instant is 0.16 (+/-0 12) m with smaller ball and only 0.07 (+/-0.03) m with a larger ball. CONCLUSIONS-Despite the small differences in the quantitative results, this probably indicates that young players transfer lesser energy on regular-ball than on adapted-size-ball. This leads up to the hypothesis that the adaptation of ball size to particular characteristics of each age scale will create better conditions for young players to learn the correct principles of shooting technique REFERENCES Satern,M.;et al. (1989); The Effect of Ball Size and Basket Height on the Mechanics of Free Throw; J. Mov. SI.; 16; 123-137

KINEMATICS IN BASKETBALL SHOOTING - THE INFLUENCES OF BASKET HEIGHT AND BALL SIZE

INTRODUCTION The majority of coaches identify shooting as the most important skill of basketball. This does not preclude the importance of other skills - dribbling, passing or footwork - but only assume that all offensive actions have shooting as their final objective. Coaches have many preocupations about the direction of team's development. Some of them revolve around the effort of teaching and developing the basic skills of offence. At the same time young players must, from an early age, practice their skills in a regular context, in similar conditions to the adult basketball game. In these more demanding conditions the successful execution of basic skills of offence actions, have the tendency to become more difficult for young players. The purpose of the present study was to analyse the effects of basket height and ball size on some mechanical parameters of shooting technique. METHODS Ten thirteen years old right-handed basketball players were the subjects in this study. A total of 11 3 shoots were digitised and analysed in a bidimensional software program named BIOSIST. Two kind of kinematics parameters were considered: instant kinematics parameters, determinate on the instant of ball release, and behaviour kinematics parameters, which are relative to shooting time. Two heights of basket and two sizes of ball were used. RESULTS Results point to significant differences in linear velocity of shooting hand and height of same segment on ball release, when regular and adapted conditions of basket height were compared. Ball size seemed to have more influence on displacement of centre of mass, particularly on its horizontal path during shooting time. Despite the small differences obtained on intersegmental angles, for both conditions of basket and ball, the adapted form of these variables promotes a better quality of execution for the players. CONCLUSION More significant than ball size, the tendency of results reveals that the adaptation of basket height could create an execution in which its characteristics are similar to theoretical models used by coaches. REFERENCES Ferreira, A.P.; Fernandes, 0.; Abrantes, J. (1996); Kinematic Analysis of Basketball Shooting. Prellimhar Results; in, 14th International Symposium on Biomechanics in Sports. Ed. by Joiio M.C.S. Abrantes; Edi~dies F.M.H., Universidade Tdcnica de Lisboa; pp. 47 1-474

Tenure matters for team cohesion and performance: The moderating role of trust in the coach

Research question: This study examines team performance as a function of team tenure, cohesion and trust in the coach. Specifically, we propose a moderated-mediation model to explain whether it translates into an objective measure of future team performance. Research methods: The study sample consists of 668 players from 73 professional and top amateur basketball league teams in Catalonia, Spain. Data collection consisted of a survey performed during a regular training session held at the beginning of the second part of the season as well as objective and subjective team performance indicators. Results and findings: Our findings suggest that the indirect effect of team tenure on performance through team cohesion is only significant for high and medium levels of cognitive trust in the coach and low levels of affective trust in the coach. Implications: These findings provide evidence that explains trust’s contribution to fostering team dynamics and how team tenure translates into future team performance. The practical implications of this study suggest that simply promoting team cohesion without taking into account the cognitive trust in the coach will not necessarily increase performance. Therefore, coaches and managers must invest in the amount of work they do with team members and their skills in order to ensure team members have high cognitive trust in them.info:eu-repo/semantics/acceptedVersio

Transformational leadership and team performance in sports teams: A conditional indirect model

This study tests how transformational leadership fosters team performance through team cohesion and how that relationship is moderated by previous team performance and leadership consensus. We computed a moderated-mediation model based on a sample of 690 professional players in 59 top professional teams in interactive team sports leagues (basketball, handball, roller hockey, and indoor football/soccer) in Spain. Our findings suggest that transformational leadership indirectly influences objective team performance through the mediation role of team cohesion and that this indirect effect is more prominent when the level of previous performance is higher. We also found that the indirect effect of transformational leadership on team performance via cohesion is stronger in teams with higher consensus regarding their coaches' leadership. Overall, our results demonstrate the importance of integrating dispersion and contextual variables into research models, in particular, previous performance and leadership consensus.info:eu-repo/semantics/publishedVersio