Modeling soil organic carbon change in croplands of China

Using 1990 conditions, we modeled carbon (C) and nitrogen (N) biogeochemical cycles in croplands of China (and, for comparison, the United States) to estimate the annual soil organic-carbon (SOC) balance for all cropland. Overall, we estimate that China\u27s croplands lost 1.6% of their SOC (to a depth of 0.3 m) in 1990, and that U.S. cropland lost 0.1%. A key element in this difference was that ∼25% of aboveground crop residue in China was returned to the soil, compared to ∼90% in the United States. In China, SOC losses were greatest in the northeast (∼103 kg C·ha–1·yr–1), and were generally smaller (\u3c0.5 × 103 kg C·ha–1·yr–1) in regions with a longer cultivation history. Some regions showed SOC gains, generally \u3c103 kg C·ha–1·yr–1. Reduced organic-matter input to China\u27s cropland soils, and lower overall SOC levels in those soils, led to lower levels of N mineralization in the simulations, consistent with higher rates of synthetic-fertilizer application in China. C and N cycles are closely linked to soil fertility, crop yield, and non-point-source environmental pollution

P19. Head impacts in youth soccer are comparable to American Football

Head Impacts in youth soccer are comparable to American Football Alexandra Harriss1, Aakash Naik1, David M. Walton2, James P. Dickey1 School of Kinesiology1, School of Physical Therapy2, Western University, London, Canada Background: Research has unequivocally demonstrated that females and youth soccer players are at a significant high risk of concussion. Recently, concerns for “heading” have been raised due to possible adverse neurological effects. While head impact accelerations and rotations have been investigated in American football, head impacts in youth soccer have not been rigorously studied. The purpose is to measure impact accelerations that result from different heading scenarios during youth soccer games. Methods: 16 players on an U-14 female youth soccer team were fitted with headbands instrumented with wireless sensors (GForceTracker, Artaflex Inc., Markham, Ontario, Canada) during eight soccer games. All games were video recorded to characterize heading scenario. Peak linear acceleration, and peak rotational velocity were recorded for each header. Results: A total of 126 header impacts were recorded, and long-range kicks accounted for 40% of all headers. Average header peak linear acceleration was 16.78 g and ranged from 7.96 g (ball deflection) to 38.62 g (drop kick). Average header peak rotational velocity was 1063 °/s and ranged from 37 °/s (long-range kick) to 2791 °/s (long-range kick). Discussions and conclusions: Header accelerations experienced by youth players depend on game scenario with largest impact accelerations from drop kicks and long-range kicks. Although the number of head impacts is smaller in soccer compared to American football, the impact magnitudes are comparable. Interdisciplinary Reflection: While the measured head accelerations are below injury thresholds, these data provide insight into the magnitude of head impacts in soccer and possible contribution to long-term cognitive deficits

Methane flux from the Central Amazonian Floodplain

A total of 186 methane measurements from the three primary Amazon floodplain environments of open water lakes, flood forests, and floating grass mats were made over the period 18 July through 2 September 1985. These data indicate that emissions were lowest over open water lakes. Flux from flooded forests and grass mats was significantly higher. At least three transport processes contribute to tropospheric emissions: ebullition from sediments, diffusion along the concentration gradient from sediment to overlaying water to air, and transport through the roots and stems of aquatic plants. Measurements indicate that the first two of these processes are most significant. It was estimated that on the average bubbling makes up 49% of the flux from open water, 54% of that from flooded forests, and 64% of that from floating mats. If the measurements were applied to the entire Amazonian floodplain, it is calculated that the region could supply up to 12% of the estimated global natural sources of methane

Abetting the market: on property, propriety and actually existing capitalisms

Global Challenges (FGGA

Translating transactions: markets as epistemic and moral spheres

In this Modern Asian Studies book symposium, scholars of South Asia analyse the political, ethical, and epistemic aspects of market life. They build on the 2020 Cambridge volume, Rethinking Markets in Modern India: Embedded Exchange and Contested Jurisdiction, edited by Ajay Gandhi, Barbara Harriss-White, Douglas Haynes, and Sebastian Schwecke. This interdisciplinary conversation approaches transactional realms from the disciplines of history, anthropology, development studies, and political economy. The symposium’s contributors examine a range of pertinent issues that encompass customary forms of exchange and capitalist aspects of trade. Among the topics discussed are those of market fetishism, bazaar knowledge, social embeddedness, forms of transactional representation and translation, and institutional and regulatory contexts for commerce.Global Challenges (FGGA

Experiencing space–time: the stretched lifeworlds of migrant workers in India

In the relatively rare instances when the spatialities of temporary migrant work, workers’ journeys, and labour-market negotiations have been the subject of scholarly attention, there has been little work that integrates time into the analysis. Building on a case study of low-paid and insecure migrant manual workers in the context of rapid economic growth in India, we examine both material and subjective dimensions of these workers’ spatiotemporal experiences. What does it mean to live life stretched out, multiplyattached to places across national space? What kinds of place attachments emerge for people temporarily sojourning in, rather than moving to, new places to reside and work? Our analysis of the spatiotemporalities of migrant workers’ experiences in India suggests that, over time, this group of workers use their own agency to seek to avoid the experience of humiliation and indignity in employment relations. Like David Harvey, we argue that money needs to be integrated into such analysis, along with space and time. The paper sheds light on processes of exclusion, inequality and diff erentiation, unequal power geometries, and social topographies that contrast with neoliberalist narratives of ‘Indian shining

An evaluation of heart rate variability in female youth soccer players following soccer heading: A pilot study

Most head impacts in soccer occur from purposeful heading; however, the link between heading and neurological impairment is unknown. Previous work suggests concussion may result in an uncoupling between the autonomic nervous system and cardiovascular system. Accordingly, heart rate variability (HRV) may be a sensitive measure to provide meaningful information regarding repetitive heading in soccer. The purpose of this pilot study assesses the feasibility of measuring HRV to evaluate autonomic function following soccer heading. Sixteen youth female participants underwent heart rate monitoring during a heading and footing condition. Participants completed a five minute resting supine trial at the start and end of each testing session. Standard 450 g soccer balls were projected at 6 m/s towards participants. Participants performed five headers, for the header condition, and five footers for the footer condition. The HRV for resting supine trials, pre-and post-header and footer conditions were assessed for both time and frequency domains. HRV effect sizes were small when comparing conditions, except absolute low frequency (d = 0.61) and standard deviation of the normal-normal (NN) intervals (d = 0.63). Participant retention and adherence were high, without adverse events. Findings suggest HRV is a feasible measure for evaluating the effects of heading on autonomic function

First Multicharged Ion Irradiation Results from the CUEBIT Facility at Clemson University

A new electron beam ion trap (EBIT) based ion source and beamline were recently commissioned at Clemson University to produce decelerated beams of multi- to highly-charged ions for surface and materials physics research. This user facility is the first installation of a DREEBIT-designedsuperconducting trap and ion source (EBIS-SC) in the U.S. and includes custom-designed target preparation and irradiation setups. An overview of the source, beamline, and other facilities as well as results from first measurements on irradiated targets are discussed here. Results include extracted charge state distributions and first data on a series of irradiated metal-oxide-semiconductor (MOS) device targets. For the MOS devices, we show that voltage-dependent capacitance can serve as a record of theelectronic component of ion stopping power for an irradiated, encapsulated oxide target