1,757 research outputs found
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
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
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
Contextual reasons for emigrants’ electoral participation in home country elections: The Portuguese case
Although emigrants represent an increasing share of the electoral population in many democracies not much is known about their participation in home country elections. Aiming at contributing to fulfil this gap, this article longitudinally and exploratory analyses the contextual factors of Portuguese emigrants’ participation in national elections (1976-2015), a country with one of the highest emigration rates of EU today. First, it presents a longitudinal analysis of the electoral participation of Portuguese emigrants, and then analyses the conditions underlying levels of participation. By using aggregate data covering the main fifteen destination countries, this study compares institutional, socio-economic and political contextual factors for voting. Findings indicate that the lack of political participation of emigrants is first demonstrated by the very low registration rates, although it varies according to the country, and that voting methods and socio-economic factors in the destination country are the most relevant to explain voting in home country elections.info:eu-repo/semantics/acceptedVersio
Biodistribuição do 18FDG em ratos nude balb-c nu/nu normaiS
Resumo do poster apresentado ao XII Congresso Nacional de Medicina Nuclear, 12-14 Novembro 2009, Mealhad
Improving cost-efficiency for MPs density separation by zinc chloride reuse
The methodology used to extract and quantify microplastics (MPs) in aquatic systems are still not standardized. Salt saturated solutions, such as sodium chloride (NaCl), zinc chloride (ZnCl2) and/or sodium iodide (NaI), are normally added to separate dense plastics from aquatic samples. However, the most effective reagents are also the most expensive (e.g. ZnCl2 and NaI). To decrease this cost, a reuse process of the salt solutions should be applied. The reuse process has been widely investigated for the NaI solution neglecting the ZnCl2. Hence, the aim of this study was to present a simple methodology to reuse the ZnCl2 solution ensuring the efficiency of the product. Results of the present study showed that ZnCl2 solution could be reused at least five times maintaining an efficiency above 95 %. •The ZnCl2 reuse decreases the cost of the methodology.•The efficiency of ZnCl2 solution after five filtrations remains above 95 % (all polymers are detected and recovered).•The use of this salt solution is the most cost-effective methodology to isolate MPs from aquatic samples.publishe
Procedimento para otimização do material propagativo de batata com alta sanidade pelo uso de brotações e minitubérculos obtidos sob condições de câmara fria.
PROCEDIMENTO PARA OTIMIZAÇÃO DO MATERIAL PROPAGATIVO DE BATATA COM ALTA SANIDADE PELO USO DE BROTAÇÕES E MINITUBÉRCULOS OBTIDOS SOB CONDIÇÕES DE CÂMARA FRIA-O desenvolvimento de tecnologias modenas para a produção de sementes básicas, registradas e certificadas, a obtenção de tubérculos livres de doença a partir de técnicas de cultura de tecidos e o desenvolvimento de testes para diagnose de doenças que interferem na produtividade, vêm permitindo a melhoria da qualidade eprodutividade da batata produzida no Brasil, refletindo-se, consequentemente, na redução progressiva das importações de batata-semene.O procedimento desenvolvido visa a otimização do material propagativode batata com sanidade, atualmente produzido com o custo relativamente elevado, permitindo a multiplicação da batata semente pré-básica durante três gerações ,sem que ocorra a contaminação pr patógenos em condições de campo.A metodologia básica consiste na utilização de brotações e minitubérculos desenvolvidos sob condições de câmara fria.Os resultados obtidos com a doação desse processo estão ligados á sustentabilidade dos agricultores, redução de custos para aquisição de material básico e melhoria da produtividade das lavouras de batata da região sul do Brasil.bitstream/item/33960/1/documento-212.pd
- …