581 research outputs found
Photosynthetic characteristics of five high light and low light exposed microalgaea as measured with 14C-uptake and oxygen electrode techniques
#Tetraselmis suecica, #Thalassiosira pseudonana, #Chaetoceros calcitrans, #Isochrysis galbana et #Microcystis sp.$ ont été utilisées pour déterminer leurs capacités d'adaptation et pour tester les différences entre les deux méthodes de mesure. Les cultures avaient été exposées à un éclairement fort (HL) ou à un éclairement faible (LL) pendant deux jours avant l'expérience. L'efficacité de la conversion de la lumière (...) et l'activité photosynthétique spécifique maximale par unité de chlorophylle (...) ont été généralement plus élevées pour les cultures LL. Les divers paramètres photosynthétiques mesurés par la méthode de l'électrode à oxygène ont été différents de ceux obtenus par celle du 14C. Les importantes différences de quotient photosynthétique (O2/CO2), observées aussi bien entre cultures HL et LL d'une même espèce qu'entre espèces différentes, soulignent la difficulté de convertir les productions d'oxygène en assimilation de carbone. (D'après résumé d'auteur
The effect of crop type, crop rotation, and tillage practice on runoff and soil loss on a Vertisol in central Queensland
In 1982, a long-term project was established in central Queensland to study the effect of crop type, crop rotation, and tillage practice on runoff and soil loss. Runoff and soil loss were measured at the outlet of 9 large contour bay catchments (approximately 13 ha) where wheat, sorghum, and sunflower were grown in 3 crop sequences. Each crop sequence consisted of zero, reduced, and conventional tillage fallow practices. Monoculture cropping was practised from 1983 to 1985, then opportunity cropping from 1986 to 1993.
During the study, wheat cropping had lower average annual runoff and soil loss (P 50%) and had less soil loss (P < 0·05) than conventional tillage. Zero tillage wheat had the lowest average annual runoff and soil loss, and conventional sunflowers had the highest. The erosion risk associated with sunflowers was reduced by a wheat–sunflower crop rotation, particularly when zero-tilled. Monoculture sunflower must be avoided.
The region is susceptible to large episodic erosion when crops are not sown, there are long fallows, and soil cover falls below levels critical to control erosion (<30%). Opportunity cropping is the most appropriate system to maximise the regions variable rainfall and reduce runoff and soil loss
Neighborhood-Based social capital and life satisfaction
In this study, we examine the relationship between neighborhood-based social capital and residents’ life satisfaction by considering resident heterogeneity. Using a database of the city of Rotterdam, The Netherlands, we find a small but significant positive association between neighborhood-based social capital and individual life satisfaction. However, we also find considerable differences among residents because neighborhood-based social capital is important mainly for people who are more likely to spend considerable time in the neighborhood or who are more neighborhood dependent (i.e. less-educated people, people who live on welfare, people with poor health, retired people, and those who are divorced or widowed). Our results confirm the importance of neighborhood-based social capital for residents’ life satisfaction in terms of both actual social contacts with neighbors and the perceived social cohesion within a neighborhood. At the same time, the importance of neighborhood-based social capital varies among different groups of residents. These findings have important implications for policy-makers
Spatial structure and subjective well-being in North-West Europe
This study examines the relationship between regions’ spatial organization and subjective well-being in North-West
Europe. Combining data on life satisfaction with data on the spatial structure of regions, we find that the degree of
polycentricism is positively associated and dispersion is negatively associated with life satisfaction. At the same time,
the results indicate that in more dispersed regions, people experience more positive effects of polycentric structures
than in more centralized regions, while residents of more urbanized polycentric regions report lower levels of life
satisfaction compared with residents of less urbanized polycentric regions. Likewise, the findings suggest that urban
residents living in polycentric regions are less satisfied compared with their rural counterparts
Spatial structure and subjective well-being in North-West Europe
This study examines the relationship between regions’ spatial organization and subjective well-being in North-West Europe. Combining data on life satisfaction with data on the spatial structure of regions, we find that the degree of polycentricism is positively associated and dispersion is negatively associated with life satisfaction. At the same time, the results indicate that in more dispersed regions, people experience more positive effects of polycentric structures than in more centralized regions, while residents of more urbanized polycentric regions report lower levels of life satisfaction compared with residents of less urbanized polycentric regions. Likewise, the findings suggest that urban residents living in polycentric regions are less satisfied compared with their rural counterparts
Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
A limited sampling schedule to estimate individual pharmacokinetics of pemetrexed in patients with varying renal functions
Purpose: Pemetrexed is a widely used cytostatic agent with an established exposure–response relationship. Although dosing is based on body surface area (BSA), large interindividual variability in pemetrexed plasma concentrations is observed. Therapeutic drug monitoring (TDM) can be a feasible strategy to reduce variability in specific cases leading to potentially optimized pemetrexed treatment. The aim of this study was to develop a limited sampling schedule (LSS) for the assessment of pemetrexed pharmacokinetics. Methods: Based on two real-life datasets, several limited sampling designs were evaluated on predicting clearance, using NONMEM, based on mean prediction error (MPE %) and normalized root mean squared error (NRMSE %). The predefined criteria for an acceptable LSS were: a maximum of four sampling time points within 8 h with an MPE and NRMSE ≤ 20%. Results: For an accurate estimation of clearance, only four samples in a convenient window of 8 h were required for accurate and precise prediction (MPE and NRMSE of 3.6% and 5.7% for dataset 1 and of 15.5% and 16.5% for dataset 2). A single sample at t = 24 h performed also within the criteria with MPE and NRMSE of 5.8% and 8.7% for dataset 1 and of 11.5% and 16.4% for dataset 2. Bias increased when patients had lower creatinine clearance. Conclusions: We presented two limited sampling designs for estimation of pemetrexed pharmacokinetics. Either one can be used based on preference and feasibility
A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector
A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance
O uso de praias arenosas com diferentes concentrações humanas por espécies de aves limícolas (Charadriidae e Scolopacidae) neárticas no sudeste do Brasil
Carcinoembryonic antigen-specific, fluorescent image-guided cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for metastatic colorectal cancer
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