Controlled Ecological Life Support Systems: Natural and Artificial Ecosystems

The scientists supported by the NASA sponsored Controlled Ecological Life Support Systems (CELSS) program have played a major role in creating a Committee on Space Research (COSPAR) section devoted to the development of bioregenerative life support for use in space. The series of 22 papers were sponsored by Subcommission F.4. The papers deal with many of the diverse aspects of life support, and with outgrowth technologies that may have commercial applications in fields such as biotechnology and bioengineering. Papers from researchers in France, Canada, Japan and the USSR are also presented

Utah’s Watershed Restoration Initiative: Restoring Watersheds at a Landscape Scale

Abstract: The Utah Watershed Restoration Initiative (WRI) is a partnership-based program, administered by the Utah Department of Natural Resources, which seeks to improve the functional capacity of high priority watersheds throughout the state. Since its inception in 2006, the WRI partnership has completed nearly 1,500 projects to restore and rehabilitate over 526,091 ha in Utah watersheds. The WRI program is unique to the west, in that it transcends jurisdictional boundaries, and local, state, and federal management authority to focus finite resources on completing high priority conservation projects. We surveyed selected WRI selected participants in 2015 to determine what factors they believed most contributed to the overall success of the program. Survey respondents attributed the success of the WRI program to: 1) engaged leadership at multiple levels, 2) a bottom-up hierarchy, 3) a history of collaboration, 4) practice partnerships, 5) a science-based approach, 6) operating at a meaningful spatial scale, 7) being solution minded, not problem focused, and 8) unselfish sharing of resources. In this paper we discuss these success factors and provide recommendations to those desiring to implement voluntary incentive-based landscape conservation strategies

The Detection and Characterization of cm Radio Continuum Emission from the Low-mass Protostar L1014-IRS

Observations by the Cores to Disk Legacy Team with the Spitzer Space Telescope have identified a low luminosity, mid-infrared source within the dense core, Lynds 1014, which was previously thought to harbor no internal source. Followup near-infrared and submillimeter interferometric observations have confirmed the protostellar nature of this source by detecting scattered light from an outflow cavity and a weak molecular outflow. In this paper, we report the detection of cm continuum emission with the VLA. The emission is characterized by a quiescent, unresolved 90 uJy 6 cm source within 0.2" of the Spitzer source. The spectral index of the quiescent component is $\alpha = 0.37\pm 0.34$ between 6 cm and 3.6 cm. A factor of two increase in 6 cm emission was detected during one epoch and circular polarization was marginally detected at the $5\sigma$ level with Stokes {V/I} $= 48 \pm 16$% . We have searched for 22 GHz H2O maser emission toward L1014-IRS, but no masers were detected during 7 epochs of observations between June 2004 and December 2006. L1014-IRS appears to be a low-mass, accreting protostar which exhibits cm emission from a thermal jet or a wind, with a variable non-thermal emission component. The quiescent cm radio emission is noticeably above the correlation of 3.6 cm and 6 cm luminosity versus bolometric luminosity, indicating more radio emission than expected. We characterize the cm continuum emission in terms of observations of other low-mass protostars, including updated correlations of centimeter continuum emission with bolometric luminosity and outflow force, and discuss the implications of recent larger distance estimates on the physical attributes of the protostar and dense molecular core.Comment: 14 pages. Accepted for publication in Ap

Natural history of Arabidopsis thaliana and oomycete symbioses

Molecular ecology of plant–microbe interactions has immediate significance for filling a gap in knowledge between the laboratory discipline of molecular biology and the largely theoretical discipline of evolutionary ecology. Somewhere in between lies conservation biology, aimed at protection of habitats and the diversity of species housed within them. A seemingly insignificant wildflower called Arabidopsis thaliana has an important contribution to make in this endeavour. It has already transformed botanical research with deepening understanding of molecular processes within the species and across the Plant Kingdom; and has begun to revolutionize plant breeding by providing an invaluable catalogue of gene sequences that can be used to design the most precise molecular markers attainable for marker-assisted selection of valued traits. This review describes how A. thaliana and two of its natural biotrophic parasites could be seminal as a model for exploring the biogeography and molecular ecology of plant–microbe interactions, and specifically, for testing hypotheses proposed from the geographic mosaic theory of co-evolution

The Spitzer c2d Survey of Nearby Dense Cores: I: First Direct Detection of the Embedded Source in IRAM 04191+1522

We report the first detections of the Class 0 protostellar source IRAM 04191+1522 at wavelengths shortward of 60 microns with the Spitzer Space Telescope. We see extended emission in the Spitzer images that suggests the presence of an outflow cavity in the circumstellar envelope. We combine the Spitzer observations with existing data to form a complete dataset ranging from 3.6 to 1300 microns and use these data to construct radiative transfer models of the source. We conclude that the internal luminosity of IRAM 04191+1522, defined to be the sum of the luminosity from the internal sources (a star and a disk), is L_int = 0.08 +/- 0.04 L_sun, placing it among the lowest luminosity protostars known. Though it was discovered before the launch of the Spitzer Space Telescope, IRAM 04191+1522 falls within a new class of Very Low Luminosity Objects being discovered by Spitzer. Unlike the two other well-studied objects in this class, which are associated either with weak, compact outflows or no outflows at all, IRAM 04191+1522 has a well-defined molecular outflow with properties consistent with those expected based on relations derived from higher luminosity (L_int > 1 L_sun) protostars. We discuss the difficulties in understanding IRAM 04191+1522 in the context of the standard model of star formation, and suggest a possible explanation for the very low luminosity of this source.Comment: Accepted for publication in the Astrophysical Journal. 39 pages, 9 figures. See http://peggysue.as.utexas.edu/SIRTF/ for high-resolution figure

Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form

Search for Gravitational Wave Bursts from Soft Gamma Repeaters

We present the results of a LIGO search for short-duration gravitational waves (GWs) associated with Soft Gamma Repeater (SGR) bursts. This is the first search sensitive to neutron star f-modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14 which occurred during the first year of LIGO's fifth science run. GW strain upper limits and model-dependent GW emission energy upper limits are estimated for individual bursts using a variety of simulated waveforms. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the model-dependent isotropic GW emission energies (at a nominal distance of 10 kpc) between 3x10^45 and 9x10^52 erg depending on waveform type, detector antenna factors and noise characteristics at the time of the burst. These upper limits are within the theoretically predicted range of some SGR models.Comment: 6 pages, 1 Postscript figur