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

Intrapreneurial dynamics: A case research at the insurance industry in Portugal

This research focusses on the firm endowments; focusing on the impact of an organizational structure and its managerial systems as the intrapreneurial conditions (IC) for constraining and/or leveraging behavioral patterns of intrapreneurial dynamics (ID). With a positivistic stance and deductive approach to theory development, the researcher attempts to test the phenomenon using a single case design with a holistic frame. The intrapreneurial assessment model of Hartman (2006) outlines the IC variables. Online questionnaires directed to the stakeholders of the partaking firm have originated a probabilistic and randomized sample of 9,70% of respondents of the target-population (670 employees). We argue that the firm´s environment has a direct impact on the intrapreneurial behavior at both, managerial and non-managerial levels, since data exhibits an interaction of variables IC-ID with a positive correlation in its mutation patterns. Herein, is not encompassed the subset of ID with roots upon corporate entrepreneurship (CE); however, it constitutes a clear gap for further statistical and analytical generalizations. This study illuminates the determinism of the organizational ecosystems on the formation of intrapreneurial ideas and ventures and shaping the new intraprises with regard to Entrepreneurial Employee Activity (EEA).info:eu-repo/semantics/publishedVersio

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

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

Comparative evolutionary analysis of IL6 in lagomorphs

Background and aims: Interleukin 6 (IL6), also known as interferon beta 2, is a class-I helical cytokine with a broad spectrum of biological activities in humoral and cellular defense. This class of cytokines has a gene structure conserved throughout vertebrates, with five coding exons. IL6 is involved in the immune response against rabbit hemorrhagic disease virus that causes a highly fatal disease in the European rabbit. Previously, IL6 from European rabbit samples belonging to the subspecies Oryctolagus cuniculus cuniculus, was shown to differ from the other mammals by extending for further 27 amino acids. This difference results from a mutation in the typical stop codon into a glutamate encoding codon. However, in other leporids (Sylvilagus spp. and Lepus spp.) that diverged from European rabbit approximately 12 million years ago this mutation was also not present. The purpose of this study was to confirm the mutation of the stop codon in other lagomorph specimens: Oryctolagus cuniculus algirus, Brachylagus idahoensis, Sylvilagus bachmanii, Lepus europaeus and Ochotona princeps. Methods: The IL6 gene was PCR-amplified and sequenced for the five lagomorph species. The obtained sequences were translated and compared with other mammalian IL6 sequences retrieved from public databases (GenBank, Ensembl and Uniprot). A maximum-likelihood (ML) tree was inferred in MEGA5 with the following options: HKY+G model, 500 bootstrap replicates and partial deletion to gaps/missing data treatment. Results: We confirmed the presence of the mutated stop codon in both O. c. cuniculus and O. c. algirus. In agreement with previous reports, we found that the stop codon is not mutated in S. bachmanii and L. europaeus. We further extended this observation to the leporid B. idahoensis and ochotonid O. princeps. In rabbits, sequence translation of IL6 continues into the exonic sequence and stops in the next STOP codon (81 nucleotides downstream). Typically, the IL6 protein has five cysteine residues that might be important to establish disulfide bonds. In rabbit, the 27 amino acid extension has four more cysteine residues. The inferred phylogeny for the IL6 gene is in agreement with what has been accepted for the mammals and lagomorphs.Conclusions: Our results indicate that in the ancestral of the Oryctolagusgenus, (approximately 2 million years ago), a single mutation at exon 5 occurred that made IL6 longer than for the other mammals. Biological implications of this extension remain to be assessed but the occurrence of the 4 extra cysteine residues might suggest some functional relevance

Electrochemical and STM Study of α,ω-alkanedithiols Self-assembled Monolayers

Self-assembled monolayers (SAMs), prepared by the immersion method, from ethanolic solutions containing α,ω-alkanedithiol, n-alkanethiol or mixed thiol/dithiol solutions, with 6, 9 and 10 carbon atoms in the alkyl chain, have been investigated. The amount of adsorbate and the SAM stability in alkaline medium is evaluated by reductive desorption of the prepared monolayers by cyclic voltammetry. An upright orientation of the dithiol self-assembled molecules and disulfide bonding at the SAM/solution interface are suggested by the higher reductive desorption charge of the dithiol monolayers (relative to thiol SAMs) for n = 6 and 9. The results show that an improvement on the stability of these dithiol SAMs is obtained by the presence of monothiols, resulting in mixed monolayers. Mixed SAMs prepared from longer alkane chain thiols, n = 10, allow to overcome the increased possibility of loop formation and therefore lower surface coverage is obtained for the 1,10-decanedithiol monolayers. Morphological characterisation of the modified electrodes is performed by scanning tunnelling microscopy (STM) ex situ, in air. Typical one atom deep thiol induced depressions are observed in the STM images of the dithiol and mixed SAMs

Spatial and temporal variability of suspended sediments concentration in Ria de Aveiro lagoon and fluxes between the lagoon and the ocean

The measurements of suspended sediment concentration in different parts of the Ria de Aveiro coastal lagoon during four tidal cycles show a significant spatial and temporal variability. Fluxes of water and suspended sediments between the lagoon and the coastal ocean were estimated for each tidal cycle applying a hydrodynamic two- dimensional numerical model and using the values measured at the lagoon mouth. The hydrodynamics of the lagoon are essentially dominated by tidal forcing. Tides are predominantly semidiurnal and are present in the entire lagoon The differences in suspended sediments concentration within the lagoon seem to be largely determined by the magnitude of the currents and by the bottom properties. As in other estuarine systems, the suspended sediments concentration fluctuated with tidal amplitude. In almost all stations, higher mean values occur during spring tides due to the strength of the tidal currents. Anomalous higher mean values observed in stations close to the tidal inlet during winter neap tide suggest that wind-induced resuspension and horizontal advection from the adjacent coastal area is taking place during that period of the year. Semidiurnal variations are explained, especially during the summer, by tidal-current velocity asymmetry (ebb dominance). Seasonal variability, with winter higher suspended sediments concentration, is probably related with wind climate, biological activity and coastal wave regime. In general, the fluxes of water and of suspended sediments between the lagoon and the coastal ocean showed a seaward flux that is consistent with the ebb dominance. Under winter neap tide conditions external factors allowed retention of suspended sediments in the lagoon

Influencia de la Laguna de Aveiro en los contenidos de metales pesados en la plataforma continental adyacente (Portugal)

A chemical analysis of Al, Ca, Fe, Mg, Cu, Pb, Zn, Cr, Co, Ni and Cd was carried out in 22 surface sediment samples of the continental shelf and upper slope between Espinho and Aveiro (Portugal). To reduce the disturbing effects of grain size, all samples were size-normalized by wet sieving (<63 µm). The fine fraction was digested with concentrated acids and analyzed by flame atomic absorption spectrometry. The Al and heavy metal concentrations displayed a similar distribution pattern, decreasing seaward. Exceptions to this general pattern are Ca, Mg and Pb distributions. The Ca contents are related to carbonated biogenic particles that are very abundant in the outer shelf. Multivariate statistical analysis was applied to all data to assess the behaviour and sources of each element analyzed. The results from factor analysis showed that terrigenous supply (from Aveiro Lagoon flow, coastal erosion and littoral drift), grain size (clay) sorting and anthropogenic influences from Aveiro Lagoon are the major factors controlling spatial variations of chemical elements in the continental shelf between Espinho and Aveiro. Unusually high contents of Pb were found in the middle shelf off Furadouro, but we could not determine the possible source of this contamination.Se realizaron análisis químicos de Al, Ca, Fe, Mg, Pb, Zn, Cr, Co, Ni y Cd en 22 muestras de sedimento superficial de la plataforma y vertiente continental entre Espinho y Aveiro (Portugal). Para reducir el efecto de la granulometría del sedimento, se normalizó el tamaño de las muestras mediante tamizado (<63 µm). Se procedió a la digestión de la fracción fina con ácidos concentrados y se analizó mediante espectrometría de absorción atómica con llama. Las concentraciones de Al y metales pesados muestran un patrón de distribución similar, disminuyendo hacia la vertiente. Las excepciones a este patrón general son las distribuciones de Ca, Mg y Pb. El contenido de Ca está relacionado con las partículas biogénicas carbonatadas que son muy abundantes en la plataforma externa. Con el objetivo de determinar el comportamiento y el origen de cada uno de los elementos analizados, se aplicaron técnicas de análisis estadístico multivariante. Los resultados obtenidos muestran que los principales factores que controlan las variaciones espaciales de los elementos químicos en la plataforma continental entre Espinho y Aveiro son los sedimentos terrígenos procedentes de la Laguna de Aveiro, de la erosión costera y de la deriva litoral; el tamaño de grano (tamaño arcillas); y la influencia antropogénica en la Laguna de Aveiro. En la plataforma media, a la altura de Furadouro, se encontraron valores elevados de Pb, aunque no hemos podido determinar la posible fuente de esta contaminación

KINEMATICAL AND DYNAMICAL ANALYSIS OF LONG JUMP TAKE-OFF: A FOUR CASES STUDY

INTRODUCTION-The take-off is one of. the most important phases of the long jump. Once there is no available knowledge on kinematic vs. dynamic relationships on the take-of, the purposes of this study were: (i) to analyse the biomechanical variations that occur at take-off; (ii) to establish relationships between kinematic and dynamic variables; (iii) to verify which of the moments of the take-off is more important to the production of the vertical velocity as well as the best result. METHODS~ Subjects for this 4-casesstudy research were well trained jumpers. Each athlete performed 6 trials, all videotaped (JVC-SVHS) in the sagitai plane for kinematical analysis (50 Hz). Simultaneously, dynamic analysis was performed through a Kistler 9218 B force plate (250 Hz). The kinematic parameters studied were: (i) resulting velocity of the center mass (VCM); (ii) horizontal velocity of the center mass (Vx); (iii) vertical velocity of the center mass (Vy); (iv) horizontal velocity of the lead leg knee (VeIK); (v) horizontal velocity of the touchdown foot (VeITd); (vi) loss of horizontal velocity (LVx); (vii) gain of vertical velocity (GVy); (viii) center mass / heel angle in the instants of touchdown and take-off (AngCM-he); (ix) knee angle (AngK); (x) support time (ST); (xi) touchdown distance (TdD); (xii) take-off angle (AngT). The described velocities and angles were determined in the following instants: (i) touchdown; (ii) maximum knee flexion and (iii) take off. The dynamical parameters studied were: fi) vertical impulse (Iz): (ii) maximum vertical force (Fzmax): (iii) time course to achieve maximum vertical force (lH/Fz max); (iv) passive impulse (lzPass}: (v) time course of the passive impulse (lHPass); (vi) active impulse (lzAct); (vii) time course of the active impulse (ßTAct); (viii) horizontal anterior posterior impulse (Iy); (ix) horizontal lateral impulse (Ix) RESULTS-The main results of this study showed that, in all cases, the major loss of the Vx and the major gain of the Vy were observed between the touchdown and the maximum knee flexion We also noticed that the knee of the lead leg has its maximum velocity at the moment of the maximum knee flexion for all subjects. This variables contribute significantly, in all cases, to the increase of the AngK in the take-off instant (psO.05), which is theoretically advantageous to the performance. One other finding was that when the values for AngCM-he in the touchdown and take-off instants were out of the theoretical limits defined by Fischer (1975), a reduced performance was observed. The observation of results also showed: (i) a increased Fzmax was always related with a higher jump length, with a higher % IZPass / IzAct, with a reduction both on ßTAct and ST, despite the correlation analysis did not always provide significant r values. CONCLUSIONS-Long jumpers should pay a special attention to the phase between the touchdown and the maximum knee flexion, where the main production of Vy occurs. There, a reduclion on ST during the take-off should be searched. Attention should also be paid to the values of the AngCM-he during the touchdown. REFERENCES Fischer, R. (1975). Weitsprung. Biomechanische untersuchungen am schweizerischen weitsprungkader mittels filmanalyse und messugen mir der mehrkomponenrenmessplattform. Diplamarbeil in biomechanik, ETH, Zurich