1,317 research outputs found

    Water droplet breakup in high speed airstreams

    Get PDF
    Water droplet disintegration in supersonic airstream

    In situ study of soil processes in an oxisol-spodosol sequence of Amazonia (Brazil)

    Get PDF
    L'étude in situ de l'évolution d'échantillons de vermiculite et de résines à cations échangeables et kelates insérés dans le sol met en évidence les processsus pédogénétiques caractérisant une séquence de sols de la région de Manaus (Brésil

    Tracing the origin of dissolved silicon transferred from various soil-plant systems towards rivers: a review

    Get PDF
    Silicon (Si) released as H4SiO4 by weathering of Si-containing solid phases is partly recycled through vegetation before its land-to-rivers transfer. By accumulating in terrestrial plants to a similar extent as some major macronutrients (0.1–10% Si dry weight), Si becomes largely mobile in the soil-plant system. Litter-fall leads to a substantial reactive biogenic silica pool in soil, which contributes to the release of dissolved Si (DSi) in soil solution. Understanding the biogeochemical cycle of silicon in surface environments and the DSi export from soils into rivers is crucial given that the marine primary bio-productivity depends on the availability of H4SiO4 for phytoplankton that requires Si. Continental fluxes of DSi seem to be deeply influenced by climate (temperature and runoff) as well as soil-vegetation systems. Therefore, continental areas can be characterized by various abilities to transfer DSi from soil-plant systems towards rivers. Here we pay special attention to those processes taking place in soil-plant systems and controlling the Si transfer towards rivers. We aim at identifying relevant geochemical tracers of Si pathways within the soil-plant system to obtain a better understanding of the origin of DSi exported towards rivers. In this review, we compare different soil-plant systems (weathering-unlimited and weathering-limited environments) and the variations of the geochemical tracers (Ge/Si ratios and d30Si) in DSi outputs. We recommend the use of biogeochemical tracers in combination with Si mass-balances and detailed physico-chemical characterization of soil-plant systems to allow better insight in the sources and fate of Si in these biogeochemical systems

    Cnidaria in UK coastal waters: description of spatio-temporal patterns and inter-annual variability

    Get PDF
    Note that the accepted version of this paper is available on open access in ORE at: http://hdl.handle.net/10871/15245Concern has been expressed over future biogeographical expansion and habitat capitalization by species of the phylum Cnidaria, as this may have negative implications on human activities and ecosystems. There is, however, a paucity of knowledge and understanding of jellyfish ecology, in particular species distribution and seasonality. Recent studies in the UK have principally focused on the Celtic, Irish and North Seas, but all in isolation. In this study we analyse data from a publicly- driven sightings scheme across UK coastal waters (2003–2011; 9 years), with the aim of increasing knowledge on spatial and temporal patterns and trends. We describe inter-annual variability, seasonality and patterns of spatial distribution, and compare these with existing historic literature. Although incidentally-collected data lack quantification of effort, we suggest that with appropriate data management and interpretation, publicly-driven, citizen-science-based, recording schemes can provide for large-scale (spatial and temporal) coverage that would otherwise be logistically and financially unattainable. These schemes may also contribute to baseline data from which future changes in patterns or trends might be identified. We further suggest that findings from such schemes may be strengthened by the inclusion of some element of effort-corrected data collection

    Monitoring Handbook 6: Analyzing and interpreting monitoring data

    Get PDF
    The basic purpose of data analysis is to identify patterns of change in your indicator over time, and to evaluate these changes. Without doing some kind of analysis, it will be difficult for you to know the effect your project is actually having. The data analysis techniques presented in this handbook are not difficult. Most of them can be easily done using little more than a calculator and scratch paper. If necessary, there are resources listed in the handbook for additional assistance analyzing your data

    Predicting Content Views Using Finite Integrals

    Get PDF
    Video hosting and sharing services enable creators and advertisers to create campaigns that engage viewers. To price the advertisements, and to give advertisers on the campaign an idea of the popularity of the content, the viewership is predicted. Both under- and over-prediction of views are associated with penalties, respectively of wasted inventory and capacity crunches. View estimations based on channel average suffer from sample bias and invisible trends. This disclosure describes techniques of in-flight view prediction, e.g., predictions of views done after the launch of a campaign for the remaining days of a campaign. The predictions of the total views on a line-up of in-flight videos are based on the distributions of prior view history. The described predictor delivers continuously improving predictions for live videos, and enables determination of whether a campaign is meeting view goals. It thereby enables real-time fine-tuning of inventory and capacity for the remaining days of the campaign

    Weekly Survivorship Curves of Soybean Aphid Biotypes 1 and 4 on Insecticidal Seed-Treated Soybean

    Get PDF
    Thiamethoxam, an insecticide used in soybean seed treatments, effectively suppresses soybean aphids (Aphis glycines) Matsumura (Hemiptera: Aphididae) for a short time after planting. However, exactly when and how quickly soybean aphid populations could increase is unknown. Likewise, we lack data on virulent soybean aphid biotypes (that can overcome soybean resistance) when fed on seed-treated soybean. Determining the survival of soybean aphids over time on insecticidal seed-treated soybean is critical for improving soybean aphid management and may provide insights to manage aphid virulence to aphid resistant-soybean. In greenhouse and field experiments, aphid-susceptible soybean plants (with and without an insecticidal seed treatment) were infested at 7, 14, 21, 28, 35, and 42 days after planting (DAP). We compared aphid survival among biotypes 1 (avirulent) and 4 (virulent) and insecticide treatment 72 h after infestation. We also measured thiamethoxam concentrations in plant tissue using liquid chromatography-tandem mass spectrometry. As expected, soybean aphid survival was significantly lower on seed-treated soybean up to 35 DAP for both biotypes, which correlates with the decrease of thiamethoxam in the plant over time. Moreover, we found no significant difference between avirulent and virulent biotype survivorship on insecticidal seed-treated soybean plants, although we did find significantly greater survival for the virulent biotype compared with the avirulent biotype on untreated soybean in the field. In conclusion, our study further characterized the relative short duration of seed treatment effectiveness on soybean aphid and showed that survivorship of virulent aphids on seed-treated soybean is similar to avirulent aphids

    A Multidimensional Approach to Pain Assessment in Critically Ill Infants During a Painful Procedure

    Get PDF
    Objectives: Inferring the pain level of a critically ill infant is complex. The ability to accurately extract the appropriate pain cues from observations is often jeopardized when heavy sedation and muscular blocking agents are administered. Near-infrared spectroscopy is a noninvasive method that may provide the bridge between behavioral observational indicators and cortical pain processing. We aimed to describe regional cerebral and systemic hemodynamic changes, as well as behavioral reactions in critically ill infants with congenital heart defects during chest-drain removal after cardiac surgery. Methods: Our sample included 20 critically ill infants with congenital heart defects, less than 12 months of age, admitted to the cardiac intensive care unit after surgery. Results: Cerebral deoxygenated hemoglobin concentrations significantly differed across the epochs (ie, baseline, tactile stimulus, noxious stimulus) (P=0.01). Physiological systemic responses and Face Leg Activity Cry Consolability (FLACC) pain scores differed significantly across the events (P<0.01). The 3 outcome measures were not found to be associated with each other. Mean FLACC pain scores during the painful procedure was 7/10 despite administration of morphine. Midazolam administration accounted for 36% of the variance in pain scores. Discussion: We demonstrated with a multidimensional pain assessment approach that significant cerebral, physiological, and behavioral activity was present in response to a noxious procedure in critically ill infants despite the administration of analgesic treatment. Considering that the sedating agent significantly dampened pain behaviors, assessment of cerebral hemodynamic in the context of pain seems to be an important addition.National Institutes of Health (U.S.) (Grant R01EB001659)National Institutes of Health (U.S.) (Grant K24NS057568)National Institutes of Health (U.S.) (Grant R21HD056009)National Institute for Biomedical Imaging and Bioengineering (U.S.)National Institute of Neurological Disorders and Stroke (U.S.)Eunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.
    corecore