U.S. International Trade: Trends and Forecasts

[Excerpt] This report provides an overview of the current status, trends, and forecasts for U.S. import and export flows as well as certain balances. The purpose of this report is to provide current data and brief explanations for the various types of trade flows along with a brief discussion of trends that may require attention or point to the need for policy changes. The use of trade policy as an economic or strategic tool is beyond the scope of this report but can be found in various other CRS reports. Further detail on trade in specific commodities, with particular countries or regions, or for different time periods, can be obtained from the Department of Commerce, U.S. International Trade Commission, or by contacting the authors of this report

Experiences with designing and managing organic rotation trials

This report was presented at the UK Organic Research 2002 Conference. Practical problems encountered in two long-term organic rotation trials at Aberdeen and Elgin are discussed. Compromises have had to be made in designing and managing the trials: how to include livestock and measure output, plot size, marking and fencing, discards and paths, replication, rotation length, randomisation of crop sequence, site uniformity, manoeuvrability of machines, soil compaction and exposure to pest damage

Effects of pH on Growth of Salvinia molesta Mitchell

Growth of giant salvinia ( Salvinia molesta Mitchell) under different pH regimes was examined at the Lewisville Aquatic Ecosystem Research Facility (LAERF) in Lewisville, Texas.(PDF has 5 pages.

Creating Common Ground

Chronicles the Embrace Open Space effort to protect land from development in Minnesota's Twin Cities. Outlines the collaboration between the foundation and nonprofit community partners to develop a multi-year public awareness communications campaign

Effect of organic crop rotations on long-term development of the weed seedbank

Changes in the weed seedbank were monitored between 1991 and 1998 in two experiments that were established to compare organic crop rotations at two sites in NE Scotland. Two rotations, replicated twice at each site, were compared and all courses of both rotations were present every year. There were relatively minor changes in weed species diversity over time, but major changes in seedbank abundance. Weed seed numbers were relatively low in rotations with a high proportion of grass/clover ley. Differences in level of seedbank across the rotation were relatively predictable at Tulloch but much less so at Woodside where factors such as the effect of the grass/clover ley seemed to play a lesser role. Other factors, such as weather and its influence on the effectiveness of weed control operations, and higher populations of ground-living arthropods, may be affecting the Woodside seedbanks

Large-Scale MIMO Detection for 3GPP LTE: Algorithms and FPGA Implementations

Large-scale (or massive) multiple-input multiple-output (MIMO) is expected to be one of the key technologies in next-generation multi-user cellular systems, based on the upcoming 3GPP LTE Release 12 standard, for example. In this work, we propose - to the best of our knowledge - the first VLSI design enabling high-throughput data detection in single-carrier frequency-division multiple access (SC-FDMA)-based large-scale MIMO systems. We propose a new approximate matrix inversion algorithm relying on a Neumann series expansion, which substantially reduces the complexity of linear data detection. We analyze the associated error, and we compare its performance and complexity to those of an exact linear detector. We present corresponding VLSI architectures, which perform exact and approximate soft-output detection for large-scale MIMO systems with various antenna/user configurations. Reference implementation results for a Xilinx Virtex-7 XC7VX980T FPGA show that our designs are able to achieve more than 600 Mb/s for a 128 antenna, 8 user 3GPP LTE-based large-scale MIMO system. We finally provide a performance/complexity trade-off comparison using the presented FPGA designs, which reveals that the detector circuit of choice is determined by the ratio between BS antennas and users, as well as the desired error-rate performance.Comment: To appear in the IEEE Journal of Selected Topics in Signal Processin

Audio-visual speech perception: a developmental ERP investigation

Being able to see a talking face confers a considerable advantage for speech perception in adulthood. However, behavioural data currently suggest that children fail to make full use of these available visual speech cues until age 8 or 9. This is particularly surprising given the potential utility of multiple informational cues during language learning. We therefore explored this at the neural level. The event-related potential (ERP) technique has been used to assess the mechanisms of audio-visual speech perception in adults, with visual cues reliably modulating auditory ERP responses to speech. Previous work has shown congruence-dependent shortening of auditory N1/P2 latency and congruence-independent attenuation of amplitude in the presence of auditory and visual speech signals, compared to auditory alone. The aim of this study was to chart the development of these well-established modulatory effects over mid-to-late childhood. Experiment 1 employed an adult sample to validate a child-friendly stimulus set and paradigm by replicating previously observed effects of N1/P2 amplitude and latency modulation by visual speech cues; it also revealed greater attenuation of component amplitude given incongruent audio-visual stimuli, pointing to a new interpretation of the amplitude modulation effect. Experiment 2 used the same paradigm to map cross-sectional developmental change in these ERP responses between 6 and 11 years of age. The effect of amplitude modulation by visual cues emerged over development, while the effect of latency modulation was stable over the child sample. These data suggest that auditory ERP modulation by visual speech represents separable underlying cognitive processes, some of which show earlier maturation than others over the course of development

Towards the Semantic Grid: A State of the Art Survey of Semantic Web Services and their Applicability to Collaborative Design, Engineering, and Procurement

Today, organizations within the engineering and manufacturing domains place as much emphasis on the management and flow of knowledge through a value chain as they do commodities that are more tangible in nature. For example, parts suppliers in the Canadian automotive sector are often asked to collaborate with auto manufacturers in designing and engineering their product, instead of simply producing and supplying it. Such fundamental changes in the overarching economics of this industry have led to a greater focus on collaboration, both in terms of communicating across geographic divides to design components, as well as new requirements to merge heterogeneous data stores in order to manage this distributed procurement process. Our work on this project centred on finding solutions to the above by surveying the state of the industry, as well as assessing the potential employability of related tools in the workplace. It was concluded that the Access Grid (a low-cost, open-source videoconferencing platform) held significant potential to facilitate the high-quality sharing of audiovisual material, while semantic technologies (the “semantic web” and “semantic web services”) represented a feasible solution to the issues of data integration. When combined, these technologies form the “semantic grid”, the focus of this paper. Overall, it is concluded that the past and present business success of this ICT in the information management sector may, with future work, link databases with the visualization interface to provide concurrent cost-benefit analyses