2,406 research outputs found
The late Pliocene palaeoenvironments and palaeoclimates of the western Iberian Atlantic margin from the Rio Maior flora
Using a revised chronology, a new palynological study on the late Pliocene (Piacenzian and earliest Gelasian) Rio Maior site of the Tagus Basin in western Portugal has been undertaken from the F98 core. Combining light microscopy and scanning electron microscopy, a total of 127 different pollen and spore taxa have been identified from the Piacenzian Lake and indicate the presence of a subtropical to warm-temperate mixed forest during the majority of the Piacenzian (3.6–2.8 Ma). It is only in the latest Piacenzian (after 2.8 Ma) that progressive ex- tinctions of climate sensitive taxa and a drop in diversity indicate a cooling and drying climate trend that has also been recorded from high-latitude localities. By the earliest Gelasian (2.58 Ma), a low diversity Ericaceae and Pinus dominated vegetation remained. The Piacenzian flora of Rio Maior also shows fluctuations in the presence of climate sensitive taxa and pollen-spore diversity that may be related to Piacenzian glaciations.This research work was part of the PhD project supported by the Portuguese
Foundation for Science and Technology (Ref. SFRH/BD/18754/2004).
The work of Diamantino I. Pereira was partially co-funded by the
European Union through the European Regional Development Fund,
based on COMPETE 2020 (Programa Operacional da Competitividade e
Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Fundação para a Ciência e Tecnologia
Satellite DNA as a target for TaqMan real-time PCR detection of the pinewood nematode, Bursaphelenchus xylophilus
The pinewood nematode (PWN),
Bursaphelenchus xylophilus
, is
a major pathogen of conifers, which impacts on forest health,
natural ecosystem stability and international trade. As a
consequence, it has been listed as a quarantine organism in
Europe. A real-time PCR approach based on TaqMan chemistry
was developed to detect this organism. Specific probe and
primers were designed based on the sequence of the
Msp
I
satellite DNA family previously characterized in the genome of
the nematode. The method proved to be specific in tests with
target DNA from PWN isolates from worldwide origin. From a
practical point of view, detection limit was 1 pg of target DNA
or one individual nematode. In addition, PWN genomic DNA or
single individuals were positively detected in mixed samples in
which
B. xylophilius
was associated with the closely related
non-pathogenic species
B. mucronatus
, up to the limit of 0.01%
or 1% of the mixture, respectively. The real-time PCR assay was
also used in conjunction with a simple DNA extraction method to
detect PWN directly in artificially infested wood samples. These
results demonstrate the potential of this assay to provide rapid,
accurate and sensitive molecular identification of the PWN in
relation to pest risk assessment in the field and quarantine
regulation
Categoria Profissionais 1° Lugar: Os microfundamentos da corrupção: por que e como as medidas anti-oportunistas devem gerenciar os riscos da corrupção?
A corrupção no Brasil – como em qualquer outro paÃs - decorre da inabilidade em oferecer resistência aos riscos de oportunismo, inerente as transações humanas, mediadas por instituições. Por isso, este ensaio qualitativo, de cunho metodológico, trata de analisar porque e como as medidas antioportunistas, de prevenção e combate à corrupção, devem aperfeiçoar suas capacidades de gerenciar os riscos de corrupção. O principal objetivo do estudo é demonstrar a premência dos esforços de construção e manutenção das capacidades institucionais de resistência à corrupção, que exigem uma transformação fundamental: a substituição das tentativas, metodologicamente, controversas de mensuração, direta ou indireta, da ocorrência de corrupção, em favor de métodos capazes de mensurar e aperfeiçoar a gerência dos riscos de corrupção. Uma proposta inovadora, ainda não incorporada à s estratégias anti-oportunistas de órgãos como a Controladoria Geral da União (CGU), responsável pela elaboração destas medidas, no âmbito da administração pública federal do Brasil. Com o objetivo de evidenciar, metodologicamente, a relevância destas mudanças, o estudo: (i) avalia a maneira pela qual a corrupção é analisada hoje, problematizando seus desafios metodológicos (conceituais e de mensuração); (ii) propõe, com base neste diagnóstico, a transformação fundamental da analise da corrupção (apresentando um novo modelo heurÃstico e explicitando seus microfundamentos); e, (iii) descreve as implicações desta transformação sobre a análise e a avaliação dos riscos de corrupção (discutindo as soluções encontradas na Austrália, por uma agência correlata a CGU).77 páginasÉtica, Cidadania e DiversidadeTexto publicado no III Concurso de monografias da Controladoria Geral da União - 200
Reactive strength index-modified : reliability, between group comparison, and relationship between its associated variables
To investigate and compare the reliability of reactive strength index-modified (RSImod) and its associated variables (jump height [JH] and [time to take-off]) 20 combat fighters and 18 physically active men participated in this study. They visited the laboratory three times; firstly, for jump familiarization and two sessions for test-retest (2–7 days apart). For both groups, the between-day changes in performance were trivial to small (≤ 1.1%). The coefficient of variation (CV) comparisons (i.e. CV ratio) demonstrated that combat athletes had a lower test-retest variation for RSImod (0.87) and JH (0.80) than non-athletes. Combat athletes demonstrated a greater JH than physically active men (0.43 vs 0.37; p = 0.03, g = 0.73), but small and non-significant differences were observed for RSImod (0.60 vs 0.55; p = 0.24, g = 0.38) and TTT (0.70 vs 0.72; p = 0.32, g = 0.33). RSImod was more positively correlated with JH (r = 0.75–0.87; p < 0.001) than negatively correlated with TTT (r = 0.45–0.54; p < 0.001). This study suggests that RSImod is a reliable variable obtained during CMJ testing in combat athletes and physically active men, with scores being slightly better for combat athletes. In terms of performance, combat athletes jumped higher than physically active men, but no differences in RSImod or TTT were observed. Lastly, RSImod was more strongly related to JH than TTT, and this was more evident in athletes than nonathletes. This indicates that the combat athletes were able to better utilize their (equal) time spent jumping (higher), possibly via greater utilization of the stretch shortening cycle, faster or more optimal motor unit recruitment, or an array of other factors
Validity and Test-retest Reliability of the Jumpo App for Jump Performance Measurement
International Journal of Exercise Science 14(7): 677-686, 2021. The vertical jump test is one of the simplest and most prevalent physical tests used in practice and research. This study investigated the validity and reliability of a new mobile application (Jumpo) for measuring jump performance on Android devices. University-aged students (n = 10; 20 ± 3 years; 176 ± 6 cm; 68 ± 9 kg) reported to the laboratory on three occasions (2-7 days apart): to be familiarized with the jump performance measurements and then for test-retest reliability assessments. Participants performed countermovement jumps (CMJ), squat jumps (SJ), and right and left single-legged jumps in random order on a force platform while being recorded by a smartphone’s slow-motion camera. Flight time was selected as the criterion variable. Strong positive correlations between the Jumpo and force platform were observed for each jump type tested (r ≥ 0.93), although the flight times obtained with the Jumpo App were systematically shorter than those provided by the force platform by 3-6% (p \u3c 0.001). The Jumpo App demonstrated a high test-retest reliability (ICC ≥ 0.94, CV ≤ 3.7%) with no differences between the coefficients of variation obtained from the Jumpo App and force platform (p ≥ 0.25). With respect to jump type, data from double-legged jumps (CMJ and SJ) were more accurately measured than data from single-legged jumps. The Jumpo App provides a valid and reliable measurement of jump performance, but the following equation should be used to calibrate its flight time results, allowing comparisons to be made to force platform data: Force platformflight time = 0.948 × Jumpoflight time + 41.515. Future studies should cross-validate the calibration equation in a different sample of individuals
The place of models and modelling in Digital Humanities: some reflections from a Research Software Engineering perspective
Il presente contributo illustra una posizione sul ruolo dei modelli e della modellizzazione nel contesto del Research Software Engineering (RSE) nelle Digital
Humanities (DH). La nostra ipotesi è che all'interno del contesto nel quale opera
il King’s Digital Lab, influenzato da fattori storici e di gestione manageriale, la
produzione di modelli è di fatto il contributo essenziale dell'RSE all'epistemologia di DH. Tuttavia, riteniamo che quando considerate da una prospettiva di RSE
olistica, che include - pur non essendo ad essa limitata – la modellizzazione empirica e predittiva, queste attività di modellizzazione non siano state studiate in
modo abbastanza sistematico da supportare a pieno questa posizione. Il nostro
contributo può soltanto indicare qualche idea e abbozzare un approccio che meriterebbero ricerche più approfonditeThis paper1 offers a position on the role of models and modelling in the context
of Research Software Engineering (RSE) in Digital Humanities (DH). Our hypothesis is that within the context that King’s Digital Lab operates, shaped by historical and management factors, the production of models is arguably the core contribution of RSE to the epistemology of DH. However, we argue that, when analysed from a holistic RSE perspective, encompassing but not limited to empirical and predictive modelling, these modelling activities have not been studied systematically enough to support such a claim in straight-forward ways. Our contribution can only gesture at some ideas and sketch a framework that would need further research
Neuronal deletion of GSK3beta increases microtubule speed in the growth cone and enhances axon regeneration via CRMP-2 and independently of MAP1B and CLASP2
BACKGROUND: In the adult central nervous system, axonal regeneration is abortive. Regulators of microtubule dynamics have emerged as attractive targets to promote axonal growth following injury as microtubule organization is pivotal for growth cone formation. In this study, we used conditioned neurons with high regenerative capacity to further dissect cytoskeletal mechanisms that might be involved in the gain of intrinsic axon growth capacity. RESULTS: Following a phospho-site broad signaling pathway screen, we found that in conditioned neurons with high regenerative capacity, decreased glycogen synthase kinase 3β (GSK3β) activity and increased microtubule growth speed in the growth cone were present. To investigate the importance of GSK3β regulation during axonal regeneration in vivo, we used three genetic mouse models with high, intermediate or no GSK3β activity in neurons. Following spinal cord injury, reduced GSK3β levels or complete neuronal deletion of GSK3β led to increased growth cone microtubule growth speed and promoted axon regeneration. While several microtubule-interacting proteins are GSK3β substrates, phospho-mimetic collapsin response mediator protein 2 (T/D-CRMP-2) was sufficient to decrease microtubule growth speed and neurite outgrowth of conditioned neurons and of GSK3β-depleted neurons, prevailing over the effect of decreased levels of phosphorylated microtubule-associated protein 1B (MAP1B) and through a mechanism unrelated to decreased levels of phosphorylated cytoplasmic linker associated protein 2 (CLASP2). In addition, phospho-resistant T/A-CRMP-2 counteracted the inhibitory myelin effect on neurite growth, further supporting the GSK3β-CRMP-2 relevance during axon regeneration. CONCLUSIONS: Our work shows that increased microtubule growth speed in the growth cone is present in conditions of increased axonal growth, and is achieved following inactivation of the GSK3β-CRMP-2 pathway, enhancing axon regeneration through the glial scar. In this context, our results support that a precise control of microtubule dynamics, specifically in the growth cone, is required to optimize axon regrowth
A complete view of galaxy evolution: panchromatic luminosity functions and the generation of metals
When and how did galaxies form and their metals accumulate? Over the last
decade, this has moved from an archeological question to a live investigation:
there is now a broad picture of the evolution of galaxies in dark matter halos:
their masses, stars, metals and supermassive blackholes. Galaxies have been
found and studied in which these formation processes are taking place most
vigorously, all the way back in cosmic time to when the intergalactic medium
(IGM) was still largely neutral. However, the details of how and why the
interstellar medium (ISM) in distant galaxies cools, is processed, recycled and
enriched in metals by stars, and fuels active galactic nuclei (AGNs) remain
uncertain. In particular, the cooling of gas to fuel star formation, and the
chemistry and physics of the most intensely active regions is hidden from view
at optical wavelengths, but can be seen and diagnosed at mid- & far-infrared
(IR) wavelengths. Rest-frame IR observations are important first to identify
the most luminous, interesting and important galaxies, secondly to quantify
accurately their total luminosity, and finally to use spectroscopy to trace the
conditions in the molecular and atomic gas out of which stars form. In order to
map out these processes over the full range of environments and large-scale
structures found in the universe - from the densest clusters of galaxies to the
emptiest voids - we require tools for deep, large area surveys, of millions of
galaxies out to z~5, and for detailed follow-up spectroscopy. The necessary
tools can be realized technically. Here, we outline the requirements for
gathering the crucial information to build, validate and challenge models of
galaxy evolution.Comment: A whitepaper submitted on 15th February 2009 in response to the call
from the Astro2010 panel: astro2010.org; uploaded as an 8-page pdf fil
Magnetic domain-wall velocity enhancement induced by a transverse magnetic field
Spin dynamics of field-driven domain walls (DWs) guided by Permalloy
nanowires are studied by high-speed magneto-optic polarimetry and numerical
simulations. DW velocities and spin configurations are determined as functions
of longitudinal drive field, transverse bias field, and nanowire width.
Nanowires having cross-sectional dimensions large enough to support vortex wall
structures exhibit regions of drive-field strength (at zero bias field) that
have enhanced DW velocity resulting from coupled vortex structures that
suppress oscillatory motion. Factor of ten enhancements of the DW velocity are
observed above the critical longitudinal drive-field (that marks the onset of
oscillatory DW motion) when a transverse bias field is applied. Nanowires
having smaller cross-sectional dimensions that support transverse wall
structures also exhibit a region of higher mobility above the critical field,
and similar transverse-field induced velocity enhancement but with a smaller
enhancement factor. The bias-field enhancement of DW velocity is explained by
numerical simulations of the spin distribution and dynamics within the
propagating DW that reveal dynamic stabilization of coupled vortex structures
and suppression of oscillatory motion in the nanowire conduit resulting in
uniform DW motion at high speed.Comment: 8 pages, 5 figure
Portal Nacional de Contratações Públicas: uma nova lógica jurÃdica, gerencial e econômica para a Lei de Licitações e Contratos
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