Slaves out of context: domestic slavery and the Anglo-Indian family, c. 1780–1830

This paper explores the place of domestic slaves in British families resident in India, c. 1780–1830, and the ways in which the presence of slaves within these Anglo-Indian households challenged British understandings of slavery as a practice. Drawing upon probate data, private correspondence and the Parliamentary Papers, it suggests that the history of slavery in the British empire must be situated within wider histories of family, household and kin. Located within the family and often conflated with servants, domestic slaves in Anglo-India came to be seen as dependent female subordinates whose gender and status placed them outside the emerging politics of emancipation

Colonial gifts : family politics and the exchange of goods in British India, c.1780 –1820

This paper situates Anglo-Indian gifts within a spectrum of emotionally-charged exchange mechanisms through which material objects circulated in British India. At one end of this spectrum was the market, perhaps best exemplified by the public auctions at which the personal possessions of deceased Anglo-Indians were sold to any buyer who could pay the purchase price set at probate. At the other end of the spectrum of exchange were gifts, commissions and bequests, forms of exchange that offered the British colonial elite mechanisms for combating the powerful centrifugal forces that operated within Anglo-Indian families—most notably disease, death and distance

Law’s empire : English legal cultures at home and abroad [Review Article]

The past few decades have witnessed a welcome expansion in historians’ understanding of English legal cultures, a development that has extended the reach of legal history far beyond the boundaries circumscribed by the Inns of Court, the central tribunals of Westminster, and the periodic provincial circuits of their judges, barristers, and attorneys. The publication of J. G. A. Pocock’s classic study. The ancient constitution and the feudal law, in 1957 laid essential foundations for this expansion by underlining the centrality of legal culture to wider political and intellectual developments in the early modern period. Recent years have seen social historians elaborate further upon the purchase exercised by legal norms outside the courtroom. Criminal law was initially at the vanguard of this historiographical trend, and developments in this field continue to revise and enrich our understanding of the law’s pervasive reach in British culture. But civil litigation – most notably disputes over contracts and debts – now occupies an increasingly prominent position within the social history of the law. Law’s empire, denoting the area of dominion marked out by the myriad legal cultures that emanated both from parliamentary statutes and English courts, is now a far more capacious field of study than an earlier generation of legal scholars could imagine. Without superseding the need for continued attention to established lines of legal history, the mapping of this imperial terrain has underscored the imperative for new approaches to legal culture that emphasize plurality and dislocation rather than the presumed coherence of the common law

The Albedo, Size, and Density of Binary Kuiper Belt Object (47171) 1999 TC36

We measured the system-integrated thermal emission of the binary Kuiper Belt Object 1999 TC36 at wavelengths near 24 and 70 microns using the Spitzer space telescope. We fit these data and the visual magnitude using both the Standard Thermal Model and thermophysical models. We find that the effective diameter of the binary is 405 km, with a range of 350 -- 470 km, and the effective visible geometric albedo for the system is 0.079 with a range of 0.055 -- 0.11. The binary orbit, magnitude contrast between the components, and system mass have been determined from HST data (Margot et al., 2004; 2005a; 2005b). Our effective diameter, combined with that system mass, indicate an average density for the objects of 0.5 g/cm3, with a range 0.3 -- 0.8 g/cm3. This density is low compared to that of materials expected to be abundant in solid bodies in the trans-Neptunian region, requiring 50 -- 75% of the interior of 1999 TC36 be taken up by void space. This conclusion is not greatly affected if 1999 TC36 is ``differentiated'' (in the sense of having either a rocky or just a non-porous core). If the primary is itself a binary, the average density of that (hypothetical) triple system would be in the range 0.4 -- 1.1 g/cm3, with a porosity in the range 15 -- 70%.Comment: ApJ, in press (May, 2006

Limits to ion energy control in high density glow discharges: Measurement of absolute metastable ion concentrations

Unprecedented demands for uniformity, throughput, anisotropy, and damage control in submicron pattern transfer are spurring development of new, low pressure, high charge density plasma reactors. Wafer biasing, independent of plasma production in these new systems is intended to provide improved ion flux and energy control so that selectivity can be optimized and damage can be minimized. However, as we show here, an inherent property of such discharges is the generation of significant densities of excited, metastable ionic states that can bombard workpiece surfaces with higher translational and internal energy. Absolute metastable ion densities are measured using the technique of self-absorption, while the corresponding velocity distributions and density scaling with pressure and electron density are measured using laser-induced fluorescence. For a low pressure, helicon-wave excited plasma, the metastable ion flux is at least 24% of the total ion flux to device surfaces. Because the metastable ion density scales roughly as the reciprocal of the pressure and as the square of the electron density, the metastable flux is largest in low pressure, high charge density plasmas. This metastable ion energy flux effectively limits ion energy and flux control in these plasma reactors, but the consequences for etching and deposition of thin films depend on the material system and remain an open question

Slow carbon and nutrient accumulation in trees established following fire exclusion in the southwestern United States.

Increasing tree density that followed fire exclusion after the 1880s in the southwestern United States may have also altered nutrient cycles and led to a carbon (C) sink that constitutes a significant component of the U.S. C budget. Yet, empirical data quantifying century-scale changes in C or nutrients due to fire exclusion are rare. We used tree-ring reconstructions of stand structure from five ponderosa pine-dominated sites from across northern Arizona to compare live tree C, nitrogen (N), and phosphorus (P) storage between the 1880s and 1990s. Live tree biomass in the 1990s contained up to three times more C, N, and P than in 1880s. However, the increase in C storage was smaller than values used in recent U.S. C budgets. Furthermore, trees that had established prior to the 1880s accounted for a large fraction (28-66%) of the C, N, and P stored in contemporary stands. Overall, our century-scale analysis revealed that forests of the 1880s were on a trajectory to accumulate C and nutrients in trees even in the absence of fire exclusion, either because growing conditions became more favorable after the 1880s or because forests in the 1880s included age or size cohorts poised for accelerated growth. These results may lead to a reduction in the C sink attributed to fire exclusion, and they refine our understanding of reference conditions for restoration management of fire-prone forests

Teachers’ perception of STEM integration and education: a systematic literature review

Background: For schools to include quality STEM education, it is important to understand teachers’ beliefs and perceptions related to STEM talent development. Teachers, as important persons within a student’s talent development, hold prior views and experiences that will influence their STEM instruction. This study attempts to understand what is known about teachers’ perceptions of STEM education by examining existing literature. Results: Study inclusion criteria consisted of empirical articles, which aligned with research questions, published in a scholarly journal between 2000 and 2016 in English. Participants included in primary studies were preK-12 teachers. After quality assessment, 25 articles were included in the analysis. Thematic analysis was used to find themes within the data. Findings indicate that while teachers value STEM education, they reported barriers such as pedagogical challenges, curriculum challenges, structural challenges, concerns about students, concerns about assessments, and lack of teacher support. Teachers felt supports that would improve their effort to implement STEM education included collaboration with peers, quality curriculum, district support, prior experiences, and effective professional development. Conclusions: Recommendations for practice include quality in-service instruction over STEM pedagogy best practices and district support of collaboration time with peer teachers. Recommendations for future research are given

Seismic Tremor Reveals Spatial Organization and Temporal Changes of Subglacial Water System

©2019. American Geophysical Union. All Rights Reserved.Subglacial water flow impacts glacier dynamics and shapes the subglacial environment. However, due to the challenges of observing glacier beds, the spatial organization of subglacial water systems and the time scales of conduit evolution and migration are largely unknown. To address these questions, we analyze 1.5‐ to 10‐Hz seismic tremor that we associate with subglacial water flow, that is, glaciohydraulic tremor, at Taku Glacier, Alaska, throughout the 2016 melt season. We use frequency‐dependent polarization analysis to estimate glaciohydraulic tremor propagation direction (related to the subglacial conduit location) and a degree day melt model to monitor variations in melt‐water input. We suggest that conduit formation requires sustained water input and that multiconduit flow paths can be distinguished from single‐conduit flow paths. Theoretical analysis supports our seismic interpretations that subglacial discharge likely flows through a single‐conduit in regions of steep hydraulic potential gradients but may be distributed among multiple conduits in regions with shallower potential gradients. Seismic tremor in regions with multiple conduits evolves through abrupt jumps between stable configurations that last 3–7 days, while tremor produced by single‐conduit flow remains more stationary. We also find that polarized glaciohydraulic tremor wave types are potentially linked to the distance from source to station and that multiple peak frequencies propagate from a similar direction. Tremor appears undetectable at distances beyond 2–6 km from the source. This new understanding of the spatial organization and temporal development of subglacial conduits informs our understanding of dynamism within the subglacial hydrologic system.Raw seismic data described in this paper are available through the Incorporated Research Institutions for Seismology Data Management Center (http://ds.iris.edu/mda/ZQ? timewindow=2015‐2016; Amundson et al., 2015). The raw weather data used in this paper can be found through the Arctic Data Center (https://doi.org/ 10.18739/A2H98ZC7V; Bartholomaus & Walter, 2018). Python code developed to carry out the analyses presented here is available at https://github.com/ voremargot/Seismic‐Tremor‐Reveals‐ Spatial‐Organization‐and‐Temporal‐ Changes‐of Subglacial‐Water‐System and https://github.com/ tbartholomaus/med_spec. This study was made possible with support from the University of Texas Institute for Geophysics and the University of Idaho. We thank Ginny Catania for the loan of weather stations. J. P. W.'s and J. M. A.'s contributions to this work were supported by the U.S. National Science Foundation (OPP‐1337548 and OPP‐ 1303895). T. C. B. thanks Dylan Mikesell for an early conversation, which inspired the analysis presented here.Ye

Detection of Contact Binaries Using Sparse High Phase Angle Lightcurves

We show that candidate contact binary asteroids can be efficiently identified from sparsely sampled photometry taken at phase angles >60deg. At high phase angle, close/contact binary systems produce distinctive lightcurves that spend most of the time at maximum or minimum (typically >1mag apart) brightness with relatively fast transitions between the two. This means that a few (~5) sparse observations will suffice to measure the large range of variation and identify candidate contact binary systems. This finding can be used in the context of all-sky surveys to constrain the fraction of contact binary near-Earth objects. High phase angle lightcurve data can also reveal the absolute sense of the spin.Comment: 4 pages, 4 figures, 1 table. Accepted for publication in ApJ

Seismic Tremor Reveals Spatial Organization and Temporal Changes of Subglacial Water System

©2019. American Geophysical Union. All Rights Reserved.Subglacial water flow impacts glacier dynamics and shapes the subglacial environment. However, due to the challenges of observing glacier beds, the spatial organization of subglacial water systems and the time scales of conduit evolution and migration are largely unknown. To address these questions, we analyze 1.5‐ to 10‐Hz seismic tremor that we associate with subglacial water flow, that is, glaciohydraulic tremor, at Taku Glacier, Alaska, throughout the 2016 melt season. We use frequency‐dependent polarization analysis to estimate glaciohydraulic tremor propagation direction (related to the subglacial conduit location) and a degree day melt model to monitor variations in melt‐water input. We suggest that conduit formation requires sustained water input and that multiconduit flow paths can be distinguished from single‐conduit flow paths. Theoretical analysis supports our seismic interpretations that subglacial discharge likely flows through a single‐conduit in regions of steep hydraulic potential gradients but may be distributed among multiple conduits in regions with shallower potential gradients. Seismic tremor in regions with multiple conduits evolves through abrupt jumps between stable configurations that last 3–7 days, while tremor produced by single‐conduit flow remains more stationary. We also find that polarized glaciohydraulic tremor wave types are potentially linked to the distance from source to station and that multiple peak frequencies propagate from a similar direction. Tremor appears undetectable at distances beyond 2–6 km from the source. This new understanding of the spatial organization and temporal development of subglacial conduits informs our understanding of dynamism within the subglacial hydrologic system.Raw seismic data described in this paper are available through the Incorporated Research Institutions for Seismology Data Management Center (http://ds.iris.edu/mda/ZQ? timewindow=2015‐2016; Amundson et al., 2015). The raw weather data used in this paper can be found through the Arctic Data Center (https://doi.org/ 10.18739/A2H98ZC7V; Bartholomaus & Walter, 2018). Python code developed to carry out the analyses presented here is available at https://github.com/ voremargot/Seismic‐Tremor‐Reveals‐ Spatial‐Organization‐and‐Temporal‐ Changes‐of Subglacial‐Water‐System and https://github.com/ tbartholomaus/med_spec. This study was made possible with support from the University of Texas Institute for Geophysics and the University of Idaho. We thank Ginny Catania for the loan of weather stations. J. P. W.'s and J. M. A.'s contributions to this work were supported by the U.S. National Science Foundation (OPP‐1337548 and OPP‐ 1303895). T. C. B. thanks Dylan Mikesell for an early conversation, which inspired the analysis presented here.Ye