Generalized Geologic Map for Land-Use Planning: Breckinridge County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock

WNT8 and BMP2B co-regulate non-axial mesoderm patterning during zebrafish gastrulation

AbstractDuring vertebrate mesoderm formation, fates are established according to position in the dorsoventral (D/V) axis of the embryo. Initially, maternal signaling divides nascent mesoderm into axial (dorsal) and non-axial (ventral) domains. Although the subsequent subdivision of non-axial mesoderm into multiple D/V fate domains is known to involve zygotic Wnt8 and BMP signaling as well as the Vent/Vox/Ved family of transcriptional repressors, how levels of signaling activity are translated into differential regulation of fates is not well understood. To address this question, we have analyzed zebrafish embryos lacking Wnt8 and BMP2b. Zebrafish wnt8; swr (bmp2b) double mutants display a progressive loss of non-axial mesoderm and a concomitant expansion of axial mesoderm during gastrulation. Mesoderm induction and specification of the axial domain occur normally in wnt8; swr mutants, but dorsal mesoderm genes eventually come to be expressed throughout the mesoderm, suggesting that the establishment of non-axial mesoderm identity requires continual repression of dorsal mesoderm factors, including repressors of ventral genes. Loss-of-function for Vent, Vox, and Ved phenocopies the wnt8; swr mutant phenotype, consistent with Wnt8 and BMP2b maintaining non-axial mesoderm identity during gastrulation through the regulation of these three transcriptional repressors. We postulate that timely differentiation of the mesoderm requires the maintenance of non-axial mesoderm identity by Wnt8 and BMP2b at the onset of gastrulation followed by subdivision of the non-axial mesoderm into different functional domains during gastrulation

Interannual and (multi-)decadal variability in the sedimentary BIT index of Lake Challa, East Africa, over the past 2200 years: assessment of the precipitation proxy

The branched vs. isoprenoid tetraether (BIT) index is based on the relative abundance of branched tetraether lipids (brGDGTs) and the isoprenoidal GDGT crenarchaeol. In Lake Challa sediments the BIT index has been applied as a proxy for local monsoon precipitation on the assumption that the primary source of brGDGTs is soil washed in from the lake's catchment. Since then, microbial production within the water column has been identified as the primary source of brGDGTs in Lake Challa sediments, meaning that either an alternative mechanism links BIT index variation with rainfall or that the proxy's application must be reconsidered. We investigated GDGT concentrations and BIT index variation in Lake Challa sediments at a decadal resolution over the past 2200 years, in combination with GDGT time-series data from 45 monthly sediment-trap samples and a chronosequence of profundal surface sediments.Our 2200-year geochemical record reveals high-frequency variability in GDGT concentrations, and therefore in the BIT index, superimposed on distinct lower-frequency fluctuations at multi-decadal to century timescales. These changes in BIT index are correlated with changes in the concentration of crenarchaeol but not with those of the brGDGTs. A clue for understanding the indirect link between rainfall and crenarchaeol concentration (and thus thaumarchaeotal abundance) was provided by the observation that surface sediments collected in January 2010 show a distinct shift in GDGT composition relative to sediments collected in August 2007. This shift is associated with increased bulk flux of settling mineral particles with high Ti?/?Al ratios during March–April 2008, reflecting an event of unusually high detrital input to Lake Challa concurrent with intense precipitation at the onset of the principal rain season that year. Although brGDGT distributions in the settling material are initially unaffected, this soil-erosion event is succeeded by a massive dry-season diatom bloom in July–September 2008 and a concurrent increase in the flux of GDGT-0. Complete absence of crenarchaeol in settling particles during the austral summer following this bloom indicates that no Thaumarchaeota bloom developed at that time. We suggest that increased nutrient availability, derived from the eroded soil washed into the lake, caused the massive bloom of diatoms and that the higher concentrations of ammonium (formed from breakdown of this algal matter) resulted in a replacement of nitrifying Thaumarchaeota, which in typical years prosper during the austral summer, by nitrifying bacteria. The decomposing dead diatoms passing through the suboxic zone of the water column probably also formed a substrate for GDGT-0-producing archaea. Hence, through a cascade of events, intensive rainfall affects thaumarchaeotal abundance, resulting in high BIT index values.Decade-scale BIT index fluctuations in Lake Challa sediments exactly match the timing of three known episodes of prolonged regional drought within the past 250 years. Additionally, the principal trends of inferred rainfall variability over the past two millennia are consistent with the hydroclimatic history of equatorial East Africa, as has been documented from other (but less well dated) regional lake records. We therefore propose that variation in GDGT production originating from the episodic recurrence of strong soil-erosion events, when integrated over (multi-)decadal and longer timescales, generates a stable positive relationship between the sedimentary BIT index and monsoon rainfall at Lake Challa. Application of this paleoprecipitation proxy at other sites requires ascertaining the local processes which affect the productivity of crenarchaeol by Thaumarchaeota and brGDGTs

Shelter from the storm : the land struggles of bonded labor in India

Meeting: Celebrating Dialogue : An International SAS2 Forum, November 3, 2008, Carleton University, Ottawa, ON, CASAS reports are made available in order to provide timely access to the information by interested researchers. This report has been subject to an internal review process to ensure accuracy and quality

SAS2

SAS reports are made available in order to provide timely access to the information by interested researchers. This report has been subject to an internal review process to ensure accuracy and quality.Towards the end of this assessment process, participants decided to present a land petition at the village assembly and with officials of the revenue department, in an attempt to broaden their network of support and draw attention to their rights. The focus of the assessment was neglect of government officials and elected representatives. Participants also recognized that gaps in information and communication related to the Katkari’s legal rights as residents of tribal lands, worsen the situation by keeping from public view illegal advantages held by wealthy landowners. The paper provides a brief overview of this situation

SAS2

SAS reports are made available in order to provide timely access to the information by interested researchers. This report has been subject to an internal review process to ensure accuracy and quality.The Katkari are classified as a Primitive Tribal Group with specific measures for legal protection of their rights, and there are provisions in the Integrated Tribal Development Project (ITDP) to compensate land owners in cases of expropriation of land. This paper provides a rationale, co-created by the villagers, to continue learning about their land rights, and to explore more actively the options for diversifying community livelihoods. The vast majority work as bonded labour on brick-making units in the region, and fear eviction now that land has been sold to a wealthy Mumbai landowner

SAS2

SAS reports are made available in order to provide timely access to the information by interested researchers. This report has been subject to an internal review process to ensure accuracy and quality.The paper outlines issues arising in a planning process with a poor tribal group who have no legal title to the land where their homes have been for decades. Families live with the constant fear of eviction, an ever-increasing occurrence in Thane District where land prices are rising rapidly due to proximity to Mumbai. The character of the project was identified and a planning approach and management tool was selected. Six months later, a second assessment was done and project modalities adjusted

SAS2

SAS reports are made available in order to provide timely access to the information by interested researchers. This report has been subject to an internal review process to ensure accuracy and quality

System support software for the Space Ultrareliable Modular Computer (SUMC)

The highly transportable programming system designed and implemented to support the development of software for the Space Ultrareliable Modular Computer (SUMC) is described. The SUMC system support software consists of program modules called processors. The initial set of processors consists of the supervisor, the general purpose assembler for SUMC instruction and microcode input, linkage editors, an instruction level simulator, a microcode grid print processor, and user oriented utility programs. A FORTRAN 4 compiler is undergoing development. The design facilitates the addition of new processors with a minimum effort and provides the user quasi host independence on the ground based operational software development computer. Additional capability is provided to accommodate variations in the SUMC architecture without consequent major modifications in the initial processors

Stability Measurements for Alignment of the NIF Neutron Imaging System Pinhole Array

The alignment system for the National Ignition Facility's neutron imaging system has been commissioned and measurements of the relative stability of the 90-315 DIM, the front and the back of the neutron imaging pinhole array and an exploding pusher target have been made using the 90-135 and the 90-258 opposite port alignment systems. Additionally, a laser beam shot from the neutron-imaging Annex and reflected from a mirror at the back of the pinhole array was used to monitor the pointing of the pinhole. Over a twelve hour period, the relative stability of these parts was found to be within {approx} {+-}18 {micro}m rms even when using manual methods for tracking the position of the objects. For highly visible features, use of basic particle tracking techniques found that the front of the pinhole array was stable relative to the 90-135 opposite port alignment camera to within {+-}3.4 {micro}m rms. Reregistration, however, of the opposite port alignment systems themselves using the target alignment sensor was found to change the expected position of target chamber center by up to 194 {micro}m