University of Wisconsin–Milwaukee

About: University of Wisconsin–Milwaukee is a education organization based out in Milwaukee, Wisconsin, United States. It is known for research contribution in the topics: Population & Gravitational wave. The organization has 11839 authors who have published 28034 publications receiving 936438 citations. The organization is also known as: UWM & University of Wisconsin-Milwaukee.

What is the role and nature of programmed cell death in phytoplankton ecology

Abstract: Cell death is a fundamental process in all metazoan organisms. In contrast, the ecological role of cell death in phytoplankton has been sorely neglected: the causes and biochemistry of cell death, and the quantitative significance of cell death in the ecology of phytoplankton populations and in broader biogeochemical cycles, are not well understood. Metazoan cell death is much better described, due to its accepted roles in the regulation of multicellular life. In metazoan cells, an influential paradigm suggests that there are two morphological outcomes of cell death, one caused by an ‘active’ pathway within the cell (so-called ‘programmed cell death’; PCD), and the other from a ‘passive’ externally-driven process (necrosis). Here, we examine the development of this paradigm, and associated concepts, in plant, animal, and microbial life, and discuss the role of cell death amongst the diverse taxa of the phytoplankton. Several recent studies suggest PCD operates in cyanobacteria, chlorophytes, and dinoflage...

GALACTIC OUTFLOWS IN ABSORPTION AND EMISSION: NEAR-ULTRAVIOLET SPECTROSCOPY OF GALAXIES AT 1 < z < 2*

Abstract: We study large-scale outflows in a sample of 96 star-forming galaxies at 1 {approx}< z {approx}< 2, using near-UV spectroscopy of Fe II and Mg II absorption and emission. The average blueshift of the Fe II interstellar absorption lines with respect to the systemic velocity is -85 {+-} 10 km s{sup -1} at z {approx} 1.5, with standard deviation 87 km s{sup -1}; this is a decrease of a factor of two from the average blueshift measured for far-UV interstellar absorption lines in similarly selected galaxies at z {approx} 2. The profiles of the Mg II {lambda}{lambda}2796, 2803 lines show much more variety than the Fe II profiles, which are always seen in absorption; Mg II ranges from strong emission to pure absorption, with emission more common in galaxies with blue UV slopes and at lower stellar masses. Outflow velocities, as traced by the centroids and maximum extent of the absorption lines, increase with increasing stellar mass with 2{sigma}-3{sigma} significance, in agreement with previous results. We study fine structure emission from Fe II*, finding several lines of evidence in support of the model in which this emission is generated by the re-emission of continuum photons absorbed in the Fe IImore » resonance transitions in outflowing gas. In contrast, photoionization models indicate that Mg II emission arises from the resonant scattering of photons produced in H II regions, accounting for the differing profiles of the Mg II and Fe II lines. A comparison of the strengths of the Fe II absorption and Fe II* emission lines indicates that massive galaxies have more extended outflows and/or greater extinction, while two-dimensional composite spectra indicate that emission from the outflow is stronger at a radius of {approx}10 kpc in high-mass galaxies than in low-mass galaxies.« less

Life in Ice-Covered Oceans

Abstract: Recent reports that Jupiter's satellites Europa and Callisto may have ice-covered oceans have fueled speculation that they may be inhabited by living organisms. Gaidos et al. analyze the thermodynamic requirements for life on Europa by analogy with life on Earth today and during past "snowball" Earth episodes. They conclude that nearly all metabolic life-styles on the present Earth will be denied to organisms on Europa and indicate which types of organisms, if any, are most likely to be found there.

Effects of autocorrelation on control chart performance

Abstract: In this article, we study the capability of the standard control chart for individual observations with fixed control limits to identify special causes reflected as isolated extreme points in the presence of autocorrelation. We consider both the application of standard Shewhart limits and moving-range limits and derive the risks of false positive and false negative when the control chart observations follow a general ARMA(p,q) process.