ALBERT

Description: The biodiversity and high productivity of coastal terrestrial and aquatic habitats are the foundation for important benefits to human societies around the world. These globally distributed habitats need frequent and broad systematic assessments, but field surveys only cover a small fraction of these areas. Satellite-based sensors can repeatedly record the visible and near-infrared reflectance spectra that contain the absorption, scattering, and fluorescence signatures of functional phytoplankton groups, colored dissolved matter, and particulate matter near the surface ocean, and of biologically structured habitats (floating and emergent vegetation, benthic habitats like coral, seagrass, and algae). These measures can be incorporated into Essential Biodiversity Variables (EBVs), including the distribution, abundance, and traits of groups of species populations, and used to evaluate habitat fragmentation. However, current and planned satellites are not designed to observe the EBVs that change rapidly with extreme tides, salinity, temperatures, storms, pollution, or physical habitat destruction over scales relevant to human activity. Making these observations requires a new generation of satellite sensors able to sample with these combined characteristics: (1) spatial resolution on the order of 30 to 100-m pixels or smaller; (2) spectral resolution on the order of 5 nm in the visible and 10 nm in the short-wave infrared spectrum (or at least two or more bands at 1,030, 1,240, 1,630, 2,125, and/or 2,260 nm) for atmospheric correction and aquatic and vegetation assessments; (3) radiometric quality with signal to noise ratios (SNR) above 800 (relative to signal levels typical of the open ocean), 14-bit digitization, absolute radiometric calibration 〈2%, relative calibration of 0.2%, polarization sensitivity 〈1%, high radiometric stability and linearity, and operations designed to minimize sunglint; and (4) temporal resolution of hours to days. We refer to these combined specifications as H4 imaging. Enabling H4 imaging is vital for the conservation and management of global biodiversity and ecosystem services, including food provisioning and water security. An agile satellite in a 3-d repeat low-Earth orbit could sample 30-km swath images of several hundred coastal habitats daily. Nine H4 satellites would provide weekly coverage of global coastal zones. Such satellite constellations are now feasible and are used in various applications.

Description: 〈p〉Nutrient overload in combination with decreased energy dissipation promotes obesity and diabetes. Obesity results in a hormonal imbalance, which among others activates G protein-coupled receptors utilizing diacylglycerol (DAG) as secondary messenger. Protein kinase D1 (PKD1) is a DAG effector, which integrates multiple nutritional and hormonal inputs, but its physiological role in adipocytes is unknown. Here, we show that PKD1 promotes lipogenesis and suppresses mitochondrial fragmentation, biogenesis, respiration, and energy dissipation in an AMP-activated protein kinase (AMPK)-dependent manner. Moreover, mice lacking PKD1 in adipocytes are resistant to diet-induced obesity due to elevated energy expenditure. Beiging of adipocytes promotes energy expenditure and counteracts obesity. Consistently, deletion of PKD1 promotes expression of the β3-adrenergic receptor (ADRB3) in a CCAAT/enhancer binding protein (C/EBP)-α- and -dependent manner, which leads to the elevated expression of beige markers in adipocytes and subcutaneous adipose tissue. Finally, deletion of PKD1 in adipocytes improves insulin sensitivity and ameliorates liver steatosis. Thus, depletion of PKD1 in adipocytes increases energy dissipation by several complementary mechanisms and might represent an attractive strategy to treat obesity and its related complications.〈/p〉

Description: 〈sec〉〈st〉Synopsis〈/st〉〈p〉〈textbox textbox-type="graphic"〉〈p〉〈inline-fig〉〈/inline-fig〉〈/p〉〈/textbox〉〈/p〉 〈p〉Nutrient overload results in hormone imbalance and activation of DAG-dependent signaling cascades including protein kinase D1 (PKD1). Here, mouse models reveal a causal role for PKD1 in controlling mitochondrial metabolism and lipid accumulation in fat cells, promoting obesity and diabetes.〈/p〉 〈p〉 〈l type="unord"〉〈li〉〈p〉PKD1 drives lipogenesis by inhibiting AMPK.〈/p〉〈/li〉 〈li〉〈p〉PKD1 inhibits mitochondrial fragmentation and respiration in adipocytes.〈/p〉〈/li〉 〈li〉〈p〉PKD1 suppresses C/EBP-α/-dependent transcription of β3 adrenergic receptor and beige adipocyte markers.〈/p〉〈/li〉 〈li〉〈p〉Deletion of PKD1 in adipocytes protects mice from obesity, type 2 diabetes and liver steatosis 〈i〉in vivo〈/i〉.〈/p〉〈/li〉〈/l〉 〈/p〉〈/sec〉