C\u3csub\u3e3\u3c/sub\u3e Perennial Grass Dominates Mixed C\u3csub\u3e3\u3c/sub\u3e/C\u3csub\u3e4\u3c/sub\u3e Grasslands After Invasion by a C\u3csub\u3e3\u3c/sub\u3e Woody Sprouter

Honey mesquite (Prosopis glandulosa) encroachment has resulted in decreased C4 mid-grass production and increased C3 mid-grass in the Southern Great Plains of the US. Woody legumes have had similar effects in Africa, Australia, and South America. Prosopis initially facilitates Texas wintergrass (Nassella leucotricha) growth under canopies, in part because N-fixation by this woody legume enriches subcanopy soils, favoring C3 species. As stand density increases, Nassella extends into interspaces between trees as well. Here we report Nassella responses in several studies that either reduced Prosopis to indirectly impact Nassella or treated Nassella directly. In a 9-year study following mechanical top-kill of Prosopis, Nassella increased production for the first 3 years before slowly declining to pre-treatment levels. C4 mid-grass production increased, but was limited to only a third of its potential by drought and Prosopis regrowth. Following a root-killing treatment of Prosopis, Nassella production and total herbaceous production were greater in treated than untreated intercanopy and subcanopy microsites 1-yr post-treatment. Nassella and perennial grass production declined in treated microsites 2-yrs post-treatment; however, total herbaceous production remained greater in treated than untreated microsites due to increased annual forb production. Targeted grazing reduced Nassella cover and reproduction, but increased bare ground. Multiple-stemmed Prosopis with low-hanging limbs protected Nassella, thus limiting targeted grazing success when trees were not removed. The Prosopis/Nassella state appears to be resistant to change and may permanently limit transition back to C4 grassland unless Prosopis is root-killed, though our results indicate that even root-killing Prosopis does not guarantee an immediate increase in C4 production. If so, managing Prosopis height and canopy cover, C:N ratios of the vegetative layer, and grazing Nassella during peak production and nutritional quality may allow profitable production until anthropogenic or natural processes result in large scale mortality of the Prosopis overstory

Soil organic

[1] We quantified the effects of repeated, seasonal fires on soil organic carbon (SOC), black carbon (BC), and total N in controls and four fire treatments differing in frequency and season of occurrence in a temperate savanna. The SOC at 0-20 cm depth increased from 2044 g C m À2 in controls to 2393-2534 g C m À2 in the three treatments that included summer fire. Similarly, soil total N (0-20 cm) increased from 224 g N m À2 in the control to 251-255 g N m À2 in the treatments that included summer fire. However, winter fires had no effect on SOC or total N. Plant species composition coupled with lower d 13 C of SOC suggested that increased soil C in summer fire treatments was related to shifts in community composition toward greater relative productivity by C 3 species. Lower d 15 N of soil total N in summer fire treatments was consistent with a scenario in which N inputs > N losses. The BC storage was not altered by fire, and comprised 13-17% of SOC in all treatments. Results indicated that fire and its season of occurrence can significantly alter ecosystem processes and the storage of C and N in savanna ecosystems

INTEC Groundwater Monitoring Report 2006

This report summarizes 2006 perched water and groundwater monitoring activities at the Idaho Nuclear Technology and Engineering Center (INTEC) located at the Idaho National Laboratory (INL). During 2006, groundwater samples were collected from a total of 22 Snake River Plain Aquifer (SRPA) monitoring wells, plus six aquifer wells sampled for the Idaho CERCLA Disposal Facility (ICDF) monitoring program. In addition, perched water samples were collected from 21 perched wells and 19 suction lysimeters. Groundwater and perched water samples were analyzed for a suite of radionuclides and inorganic constituents. Laboratory results in this report are compared to drinking water maximum contaminant levels (MCLs). Such comparison is for reference only and it should be noted that the Operable Unit 3-13 Record of Decision does not require that perched water comply with drinking water standards

Design and Development of On-orbit Servicing CubeSat-class Satellite

The long term vision of the Naval Academy Satellite Team for Autonomous Robotics (NSTAR) is to lower both the risk and cost of on-orbit space system construction and repair through the use of a CubeSat robotic arm system. NSTAR developments will enable space agencies and private companies to construct large, complex structures in space at a reduced cost with greater diagnostic assessment ability. Robotic Experimental Construction Satellite (RECS) is designed as NSTAR’s second project iteration and works to meet five different capabilities for semi-autonomous orbit assembly. RECS is a 3U CubeSat with two extendable robotic arms, each with six degrees of freedom. In coordination with the launch manifest, RECS has been designed, completed, and is awaiting launch to the ISS where it will conduct testing. This type of on-orbit demonstration has never been completed on CubeSat-scale systems. A successful mission will indicate entry into a new frontier of satellites, where space systems remain in operation longer, missions are of lower cost, and the ability to complete space-based scientific research is expanded. This paper provides the details of the design and capabilities of the NSTAR system

Optimization viewpoint on Kalman smoothing, with applications to robust and sparse estimation

In this paper, we present the optimization formulation of the Kalman filtering and smoothing problems, and use this perspective to develop a variety of extensions and applications. We first formulate classic Kalman smoothing as a least squares problem, highlight special structure, and show that the classic filtering and smoothing algorithms are equivalent to a particular algorithm for solving this problem. Once this equivalence is established, we present extensions of Kalman smoothing to systems with nonlinear process and measurement models, systems with linear and nonlinear inequality constraints, systems with outliers in the measurements or sudden changes in the state, and systems where the sparsity of the state sequence must be accounted for. All extensions preserve the computational efficiency of the classic algorithms, and most of the extensions are illustrated with numerical examples, which are part of an open source Kalman smoothing Matlab/Octave package.Comment: 46 pages, 11 figure

Education policy as an act of white supremacy: whiteness, critical race theory and education reform

The paper presents an empirical analysis of education policy in England that is informed by recent developments in US critical theory. In particular, I draw on ‘whiteness studies’ and the application of Critical Race Theory (CRT). These perspectives offer a new and radical way of conceptualising the role of racism in education. Although the US literature has paid little or no regard to issues outside North America, I argue that a similar understanding of racism (as a multifaceted, deeply embedded, often taken-for-granted aspect of power relations) lies at the heart of recent attempts to understand institutional racism in the UK. Having set out the conceptual terrain in the first half of the paper, I then apply this approach to recent changes in the English education system to reveal the central role accorded the defence (and extension) of race inequity. Finally, the paper touches on the question of racism and intentionality: although race inequity may not be a planned and deliberate goal of education policy neither is it accidental. The patterning of racial advantage and inequity is structured in domination and its continuation represents a form of tacit intentionality on the part of white powerholders and policy makers. It is in this sense that education policy is an act of white supremacy. Following others in the CRT tradition, therefore, the paper’s analysis concludes that the most dangerous form of ‘white supremacy’ is not the obvious and extreme fascistic posturing of small neonazi groups, but rather the taken-for-granted routine privileging of white interests that goes unremarked in the political mainstream

Even Between-Lap Pacing Despite High Within-Lap Variation During Mountain Biking

Purpose: Given the paucity of research on pacing strategies during competitive events, this study examined changes in dynamic high-resolution performance parameters to analyze pacing profiles during a multiple-lap mountain-bike race over variable terrain. Methods: A global-positioning-system (GPS) unit (Garmin, Edge 305, USA) recorded velocity (m/s), distance (m), elevation (m), and heart rate at 1 Hz from 6 mountain-bike riders (mean ± SD age = 27.2 ± 5.0 y, stature = 176.8 ± 8.1 cm, mass = 76.3 ± 11.7 kg, VO2max = 55.1 ± 6.0 mL · kg–1 . min–1) competing in a multilap race. Lap-by-lap (interlap) pacing was analyzed using a 1-way ANOVA for mean time and mean velocity. Velocity data were averaged every 100 m and plotted against race distance and elevation to observe the presence of intralap variation. Results: There was no significant difference in lap times (P = .99) or lap velocity (P = .65) across the 5 laps. Within each lap, a high degree of oscillation in velocity was observed, which broadly reflected changes in terrain, but high-resolution data demonstrated additional nonmonotonic variation not related to terrain. Conclusion: Participants adopted an even pace strategy across the 5 laps despite rapid adjustments in velocity during each lap. While topographical and technical variations of the course accounted for some of the variability in velocity, the additional rapid adjustments in velocity may be associated with dynamic regulation of self-paced exercise

Chemical Weed and Brush Control: Suggestions for Rangeland

34 pp.,2 tables, 3 chartsMillions of acres of Texas rangeland support an excessive cover of woody plants and forbs. This publication lists herbicides to use for controlling brush and weeds on rangeland. It can help in developing a brush management program that gives optimum benefits to livestock and wildlife. See B-1466A for a 2007 update of information in this publication. A copy of B-1466A is included with each orde

The Decline of Remarriage: Evidence From German Village Populations in the Eighteenth and Nineteenth Centuries

Family reconstitution data for fourteen German village populations permit the examination of remarriage during the eighteenth and nineteenth cen turies. The results provide compelling evidence for a secular decline in the tenden cy to remarry. Pronounced age and sex differentials in the likelihood of remar riage were evident: widows were far less likely to remarry than widowers, and the probability of remarriage declined rapidly with age, particularly for women. The probability of remarriage was also inversely associated with the number and age of children. There were, however, no clear differences in either the probability of remarriage or its tendency to decline over time among major occupational groups. The decline in remarriage probabilities was caused in part by declines in adult mortality, which gradually raised the ages of surviving spouses to levels at which remarriage has historically been rather unlikely. However, age-specific marriage probabilities also declined, affecting both men and women and all oc cupational groups, suggesting the presence of a social change of wide scope. Some comments on possible factors contributing to the decline of remarriage are presented. The need for a comprehensive explanation of remarriage trends and differentials remains an important challenge for family historians.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68212/2/10.1177_036319908501000103.pd

A multi-decade record of high quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) “living data” publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT_V3_GRID