Search

ISLET1 is a homeodomain transcription factor necessary for development of the pituitary, retina, motor neurons, heart, and pancreas. Isl1-deficient mice (Isl1−/−) die early during embryogenesis at embryonic day 10.5 due to heart defects, and at that time, they have an undersized pituitary primordium. ISL1 is expressed in differentiating pituitary cells in early embryogenesis. Here, we report the cell-specific expression of ISL1 and assessment of its role in gonadotropes and thyrotropes. Isl1expression is elevated in pituitaries of Cga−/−mice, a model of hypothyroidism with thyrotrope hypertrophy and hyperplasia. Thyrotrope-specific disruption of Isl1with Tshb-creis permissive for normal serum TSH, but T4levels are decreased, suggesting decreased thyrotrope function. Inducing hypothyroidism in normal mice causes a reduction in T4levels and dramatically elevated TSH response, but mice with thyrotrope-specific disruption of Isl1have a blunted TSH response. In contrast, deletion of Isl1in gonadotropes with an Lhb-cretransgene has no obvious effect on gonadotrope function or fertility. These results show that ISL1 is necessary for maximal thyrotrope response to hypothyroidism, in addition to its role in development of Rathke's pouch. more...

Abstract. Certain genera of bacteria found in the near-surface layer of the ocean can be involved in the production and decay of surface active materials (surfactants), resulting in slicks on the sea surface. Slicks can be observed with airborne or satellite-based synthetic aperture radar (SAR). Here, we report results that point to a connection between the presence of surfactant-producing bacteria in the upper layer of the ocean and slicks, observed visually and in SAR imagery of the sea surface. From DNA analysis of in situ samples taken during RADARSAT-2 satellite overpass in the Straits of Florida during the 2010 Deepwater Horizon oil spill, we found a higher abundance of known surfactant-producing bacteria in the slick compared to the nonslick area; furthermore, a higher abundance of these bacteria were observed in the water column compared to those taken from the sea surface. Surfactants produced by marine bacteria in the organic matter-rich water column can then be transported to the sea surface through diffusion or advection. Within a certain range of wind-wave conditions, the organic materials (such as dissolved oil) in the water column processed by surfactant-associated bacteria can, thus, be monitored with high-resolution remote sensing techniques.Résumé. Certains genres de bactéries présents près de la surface de l'océan peuvent être impliqués dans la production et la décomposition de matières actives à la surface (agents tensioactifs), causant des films sur la surface de l'océan. Ces films peuvent être observés à l'aide de radars à synthèse d'ouverture (RSO) aéroportés ou satellitaires. Ici, nous rapportons des résultats qui suggèrent un lien entre la présence de bactéries productrices d'agents tensioactifs dans la couche supérieure de l'océan et des films observés visuellement et dans l'imagerie RSO de la surface de l'océan. À partir d'analyses d'ADN provenant d'échantillons in situ pris lors du passage du satellite RADARSAT-2 au-dessus du détroit de Floride au cours du déversement de pétrole de la plateforme Deepwater Horizon en 2010, nous avons trouvé une plus grande abondance de bactéries connues comme productrices d'agents tensioactifs dans la nappe par rapport à la zone à l'extérieur de la nappe. En outre, une plus grande abondance de ces bactéries a été observée dans la colonne d'eau par rapport à la surface. Les agents tensioactifs produits par les bactéries marines dans la colonne d'eau riche en matière organique peuvent ensuite être transportés à la surface de l'océan par diffusion ou advection. Dans une certaine gamme de conditions de vent et de vagues, les matières organiques (tels que le pétrole dissous) dans la colonne d'eau transformées par des bactéries qui sont associées à des agents tensioactifs peuvent ainsi être surveillées par des techniques de télédétection à haute résolution. more...

Healthy governance systems are key to delivering effective outcomes in any broad domain of natural resource management (NRM). One of Australia's emerging NRM governance domains is our national framework for greenhouse gas abatement (GGA), as delivered through a wide range of management practices in the Australian landscape. The emerging Landscape-Based GGA Domainrepresents an innovative governance space that straddles both the nation's broader NRM Policy and Delivery Domainand Australia's GGA Domain. As a point-in-time benchmark, we assess the health of this hybrid domain as it stood at the end of 2013. At that time, the domain was being progressed through the Australian government's Clean Energy Package and, more particularly, its Carbon Farming Initiative (CFI). While significant changes are currently under development by a new Australian government, this paper explores key areas of risk within the governance system underpinning this emerging hybrid domain at that point in time. We then map some potential reform or continuous improvement pathways required (from national to paddock scale) with the view to securing improved landscape outcomes over time through widespread GGA activities. more...

Using a state, pressure, response framework, we provide an evidence-based reflection on environmental outcomes in Australia and New Zealand across the domains of climate change, biodiversity, freshwater and marine management, emphasising the role of Indigenous and business perspectives. Significant developments have occurred in the past 20 years through affirmation of Indigenous rights and responsibilities. Responses to climate change have tended to emphasise passive risk management with unclear outcomes. Despite meeting biodiversity protection targets, outcomes are worsening, suggesting a need to challenge the dualistic preservation/production land categorisations. In freshwater and marine management, a mix of collaborative and market-based responses has emerged, although their efficacy remains untested. A reliance on voluntary approaches by business makes critical assessment of progress difficult. Thus, despite strong progress in some areas, the adaptiveness of environmental management remains limited, and many indicators suggest continuing decline in environmental condition. Our responses have been largely pacifying in nature, leading to perverse outcomes and failure to acknowledge alternatives that might address deteriorating environmental conditions. A shift is needed towards deliberative policy experimentation that truly values the application of novel and diversified approaches and facilitates integrated learning across environmental domains. more...

Objective:To review the use of intravenous albumin solutions in intensive care units in the United Kingdom.