The Dark Energy Survey and operations: Years 4 and 5

The Dark Energy Survey (DES) is an operating optical survey aimed at understanding the accelerating expansion of the universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the 5000 sq-degree wide field and 30 sq-degree supernova surveys, the DES Collaboration built the Dark Energy Camera (DECam), a 3 square-degree, 570-Megapixel CCD camera that was installed at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO). DES has completed its third observing season out of a nominal five. This paper describes DES “Year 4” (Y4) and “Year 5” (Y5), the survey strategy, an outline of the survey operations procedures, the efficiency of operations and the causes of lost observing time. It provides details about the quality of these two-season's data, a summary of the overall status, and plans for the final survey season

A study of soil methane sink regulation in two grasslands exposed to drought and N fertilization

Oxidation by soil bacteria is the only biological sink for atmospheric methane (CH4). There are substantial uncertainties regarding the global size of this sink, in part because the ecological controls of the involved processes are not well understood to date. We have investigated effects of severe summer drought and of nitrogen inputs (ammonium nitrate or cattle urine) on soil CH4 fluxes in a field experiment. Soil moisture was the most important factor regulating the temporal dynamics of CH4 fluxes. Simulated drought episodes altered the soil’s water balance throughout the year, increasing CH4 oxidation by 50% on an annual basis. N fertilizers exerted only small and transient effects at the ecosystem level. Laboratory incubations suggested that effects differed between soil layers, with larger effects of drought and N application in the top soil than in deeper layers. With soil moisture being the primary controlling factor of methanotrophy, a detailed understanding of the ecosystem’s water balance is required to predict CH4 budgets under future climatic conditions

Social touch

The more social aspects of touch, despite their relevance to numerous domains of human behavior, from cultural anthropology to cognitive neuroscience, and from virtual reality through to linguistics, have not been extensively studied by scientists. That is, psychologists and neuroscientists are only now beginning to uncover some of the neurocognitive mechanisms responsible for these important real-world interactions. In this chapter, we summarize the latest developments in this field of research. In particular, we highlight a number of studies where touch, no matter whether direct or mediated by technological devices, has been shown to affect our behavior, as well as our physiological reactions. We show how this sensory modality often acts as a powerful interface allowing us to interact socially and emotionally with the world around us. The available research also suggests that touch plays an important role in supporting our well-being