Spatial and Temporal Variation of Sea Ice Geophysical Properties and Microwave Remote Sensing Observations: The SIMS'90 Experiment

In this paper we present results from a sea ice field experiment conducted coincidentally with overflights of orbital and aerial remote sensing instrumentation in Resolute Passage and Barrow Strait, Northwest Territories, Canada. Our principal focus is to describe the spatial and temporal distribution of selected geophysical variables in the context of how microwave energy interacts with this seasonally varying snow-covered sea ice surface. Over the duration of the experiment, snow crystal size, structure, and snow volume salinities changed sufficiently to affect synthetic aperture radar (SAR) scattering; thermal profiles through the snow cover were diurnally driven; ice surface microscale roughness increased due to sublimation of water vapour from the snow pack onto the ice surface; and bulk ice surface; and bulk ice salinities did not change. Results from the SAR data analysis indicate that the geophysical structure of multiyear ice created a larger and more rapid change in the seasonal SAR scattering signature than did the structure for early consolidated smooth first-year ice. These results are considered fundamental to measurement and monitoring of the seasonal evolution of the snow-covered arctic sea ice surface using SAR remote sensing.Key words: snow, sea ice, synthetic aperture radar, seasonal evolution, remote sensingRÉSUMÉ. On présente dans cet article les résultats d’expériences sur le terrain portant sur la glace marine, menées paralltAernent à des survols d’appareils de télédétection en orbite ou aéroportés, dans la baie Resolute et le détroit de Barrow (Territoires du Nord-Ouest). Notre objectif principalest de décrire la distribution spatiale et temporelle de variables géophysiques choisies, en considérant la façon dont l’énergie micro-onde réagit avec la surface de glace marine couverte de neige et qui varie avec les saisons. Pendant la durée des expériences, la taille des cristaux de neige, leur structure et la salinité du volume nival ont changé suffisamment pour influer sur la diffusion du radar à antenne synthétique (RAAS); les profils thermiques à travers le couvert nival suivaient un rythme diurne; la rugosité à petite échelle de la surface de la glace augmentait par suite de la sublimation de la vapeur d’eau venant de la neige qui y était accumulée; et la salinité de la masse de glace n’était pas modifiée. Les résultats de l’analyse des données recueillies avec le RAAS montrent que la structure géophysique de la glace de plusieurs années créait un changement plus important et plus rapide dans la signature saisonnière de la diffusion du RAAS, que ne le faisait la structure de la glace lisse de l’année récemment consolidée. On pense que ces résultats sont très importants pour les mesures et la surveillance, à l’aide de la télédétection au RAAS, de l’évolution saisonnière de la surface de la glace marine arctique recouverte de neige.Mots clés: neige, glace marine, radar à antenne synthétique, évolution saisonnière. télédétectio

Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

Diplonine, a neurotoxin isolated from cultures of the fungus Stenocarpella maydis (Berk.) Sacc. that induces Diplodiosis

Diplodiosis is a neuromycotoxicosis of cattle and sheep caused by ingestion of maize infected with the ear-rot fungus Stenocarpella (= Diplodia) maydis. Apart from ataxia, paresis, and paralysis, the toxin is responsible for stillbirths and neonatal losses characterized by the presence of spongiform degeneration in the white matter of the brain in the offspring of dams exposed to infected maize cobs. In the present study a toxin, named diplonine, which induced neurological signs in guinea pigs resembling some of those occurring in cattle and sheep, was isolated from S. maydis cultures. Purification of diplonine was achieved by methanol extraction followed by chromatographic separation on silica gel and RP-18 stationary phases. The structure and relative configuration of diplonine were defined by analysis of NMR and MS data as (S)-2-amino-2-[(1R,2S)-1-hydroxy-2-methylcyclopropyl] acetic acid or the (S)-2-amino-2-[(1S,2R)-diastereomer.The Maize Trust and the Gauteng Department of Agriculture, Conservation and Environment through the Directorate: Technology Development and Support.http://pubs.acs.org/JAF

Carbon dioxide capture and geological storage

Carbon dioxide capture and geological storage is a technology that could be used to reduce carbon dioxide emissions to the atmosphere from large industrial installations such as fossil fuel-fired power stations by 80–90%. It involves the capture of carbon dioxide at a large industrial plant, its transport to a geological storage site and its longterm isolation in a geological storage reservoir. The technology has aroused considerable interest because it can help reduce emissions from fossil fuels which are likely to remain the dominant source of primary energy for decades to come. The main issues for the technology are cost and its implications for financing new or retrofitted plants, and the security of underground storage