Three-Dimensional Flow, Morphologic Change, and Sediment Deposition and Distribution of Actively Evolving Neck Cutoffs Located on the White River, Arkansas

Neck cutoffs are important and prominent features of alluvial rivers yet detailed field-based research of neck cutoffs has been insufficient to fully characterize three-dimensional flow, morphologic change, and sediment deposition and distribution. The main objectives of this research are to examine the formation and evolution of neck cutoffs by characterizing the flow field, morphology, and sediment distribution through neck cutoffs with complex planform configurations located on the White River, Arkansas. Results led to the production of two conceptual models. The flow model has main hydrodynamic characteristics of (1) tight bend flow resulting from flow redirection of nearly 180° through the point of cutoff, (2) a zone of flow separation and recirculation adjacent to the cutoff junction corner within the downstream limb, (3) zones of recirculation at the entrance and exit of the abandoned loop, (4) highly asymmetric flow through the cutoff channel, (5) a zone of recirculation along the outer bank within the apex region of the downstream loop, and (6) reversal of helical flow. The morphologic model shows (1) the formation of a longitudinal bar in the upstream meander limb, (2) the development of a deep scour hole in the downstream meander limb, 3) erosion of the bank opposite the cutoff in the downstream meander limb, 4) a cutoff bar in the downstream meander limb at the junction corner of the cutoff channel and the downstream meander limb, and 5) perching of the exit of the abandoned bend above the cutoff channel due to channel bed incision. A combination of sediment cores, surface and grab samples, and dune tracking were used to estimate bedload sediment transport and sediment distribution through two of the neck cutoffs. Results indicate similar bedload sediment transport during bankfull and flood stages and revealed mixed load deposition associated with cutoffs that plug slowly is occurring within the abandoned bends. The research should result in invaluable information about hydrodynamic and morphologic processes of neck cutoffs, refine current conceptual models of neck cutoffs, and contribute to our understanding of meandering rivers with complex planform configurations

The Effects of Augmented Attentional Focus on the Performance with Practice of a Closed Perceptual-Motor Task for Individuals Who Differ in Task Mastery

The purpose of this study was to investigate the effects of augmented attentional focus on the performance with practice, of a closed perceptual-motor task for individuals who differ in task mastery. Sixty-four male volunteers were assigned to either the beginning or advanced task mastery group (n = 32) based on bowling averages (≤ 130, ≥ 150 respectively). Each subject in the task mastery groups was randomly assigned to one of four augmented focus of attention conditions, i.e., focus on: (a) environmental results of the movement that was performed (KR); (b) the movement that was performed (KP); (c) self via presence of VTR camera and monitor (VTR); or (d) nothing by experimental manipulation (control). The hypotheses tested the theoretical projections of Gentile (1972) and Fleishman and Rich (1963), i.e., (a) for beginning bowlers the augmented attention to KR group would perform better than the KP, VTR, or control groups, and (b) for advanced bowlers the augmented attention to KP and/or VTR groups would perform better than the KR or control groups. Each subject rolled 30 balls at a full ten-pin set-up. The pinfall and distance from target scores were averaged and grouped into six blocks of five trials each. For both levels of task mastery, an a priori test of planned comparisons and an analysis of variance for the split plot factorial (4.6) were used to analyze the data. Results indicated that: (a) the bowling accuracy of beginning bowlers who received an augmented attentional focus to KR was significantly better ( p_ ≤ .004) than that of the beginning control group with no other group differences; (b) the distance from target scores of the advanced bowlers who received an augmented attentional focus to KP were more accurate ( p_ = .038) than those of the KR focus or advanced control group; (c) there were no significant ( p_ ≤ .03) main effects for pinfall between group factors at either level of task mastery; and (d) there were no significant ( p_ ≤ .05) main or interaction effects for within group factors at either level of task mastery. In conclusion, the results of the study partially supported the theoretical projections of Gentile (1972) and Fleishman and Rich (1963)

New South Wales Vegetation classification and Assessment: Part 3, plant communities of the NSW Brigalow Belt South, Nandewar and west New England Bioregions and update of NSW Western Plains and South-western Slopes plant communities, Version 3 of the NSWVCA database

This fourth paper in the NSW Vegetation Classification and Assessment series covers the Brigalow Belt South-/1(BBS) and Nandewar (NAN) Bioregions and the western half of the New England Bioregion (NET), an area of 9.3 million hectares being 11.6% of NSW. It completes the NSWVCA coverage for the Border Rivers-Gwydir and Namoi CMA areas and records plant communities in the Central West and Hunter–Central Rivers CMA areas. In total, 585 plant communities are now classified in the NSWVCA covering 11.5 of the 18 Bioregions in NSW (78% of the State). Of these 226 communities are in the NSW Western Plains and 416 are in the NSW Western Slopes. 315 plant communities are classified in the BBS, NAN and west-NET Bioregions including 267 new descriptions since Version 2 was published in 2008. Descriptions of the 315 communities are provided in a 919 page report on the DVD accompanying this paper along with updated reports on other inland NSW bioregions and nine Catchment Management Authority areas fully or partly classified in the NSWVCA to date. A read-only version of Version 3 of the NSWVCA database is on the DVD for use on personal computers. A feature of the BBS and NAN Bioregions is the array of ironbark and bloodwood Eucalyptusdominated shrubby woodlands on sandstone and acid volcanic substrates extending from Dubbo to Queensland. This includes iconic natural areas such as Warrumbungle and Mount Kaputar National Parks and the 500,000 ha Pilliga Scrub forests. Large expanses of basalt-derived soils support grassy box woodland and native grasslands including those on the Liverpool Plains; near Moree; and around Inverell, most of which are cleared and threatened. Wetlands occur on sodic soils near Yetman and in large clay gilgais in the Pilliga region. Sedgelands are rare but occupy impeded creeks. Aeolian lunettes occur at Narran Lake and near Gilgandra. Areas of deep sand contain Allocasuarina, eucalypt mallee and Melaleuca uncinata heath. Tall grassy or ferny open forests occur on mountain ranges above 1000m elevation in the New England Bioregion and on the Liverpool Range while grassy box woodlands occupy lower elevations with lower rainfall and higher temperatures. The vegetation classification and assessment is based on over 100 published and unpublished vegetation surveys and map unit descriptions, expert advice, extra plot sampling and data analysis and over 25 000 km of road traverse with field checking at 805 sites. Key sources of data included floristic analyses produced in western regional forest assessments in the BBS and NAN Bioregions, floristic analyses in over 60 surveys of conservation reserves and analysis of plot data in the western NET Bioregion and covering parts of the Namoi and Border Rivers- Gwydir CMA areas. Approximately 60% of the woody native vegetation in the study area has been cleared resulting in large areas of “derived” native grasslands. As of June 2010, 7% of the area was in 136 protected areas and 127 of the 315 plant communities were assessed to be adequately protected in reserves. Using the NSWVCA database threat criteria, 15 plant communities were assessed as being Critically Endangered, 59 Endangered, 60 Vulnerable, 99 Near Threatened and 82 Least Concern. 61 of these communities are assessed as part of NSW or Commonwealth-listed Threatened Ecological Communities. Current threats include expanding dryland and irrigated cropping on alluvial plains, floodplains and gently undulating topography at lower elevations; over-grazing of steep hills; altered water tables and flooding regimes; localized mining; and the spread of exotic species, notably Coolatai Grass (Hyparrhenia hirta)

Effects of the federal programs for corn and other grains on corn prices, feed grains production and livestock production

This is the second report in a series dealing with the effects of the federal corn program on producers, processors and distributors, and consumers. The first report showed the effects of the corn stabilization program on corn utilization and the size and location of corn stabilization stocks.1 The present report covers a broader field. It analyzes the effects of the corn and other feed grains programs on the prices and production of these grains and livestock

Durrington Walls to West Amesbury by way of Stonehenge: a major transformation of the Holocene landscape

A new sequence of Holocene landscape change has been discovered through an investigation of sediment sequences, palaeosols, pollen and molluscan data discovered during the Stonehenge Riverside Project. The early post-glacial vegetational succession in the Avon valley at Durrington Walls was apparently slow and partial, with intermittent woodland modification and the opening-up of this landscape in the later Mesolithic and earlier Neolithic, though a strong element of pine lingered into the third millennium BC. There appears to have been a major hiatus around 2900 cal BC, coincident with the beginnings of demonstrable human activities at Durrington Walls, but slightly after activity started at Stonehenge. This was reflected in episodic increases in channel sedimentation and tree and shrub clearance, leading to a more open downland, with greater indications of anthropogenic activity, and an increasingly wet floodplain with sedges and alder along the river’s edge. Nonetheless, a localized woodland cover remained in the vicinity of DurringtonWalls throughout the third and second millennia BC, perhaps on the higher parts of the downs, while stable grassland, with rendzina soils, predominated on the downland slopes, and alder–hazel carr woodland and sedges continued to fringe the wet floodplain. This evidence is strongly indicative of a stable and managed landscape in Neolithic and Bronze Age times. It is not until c 800–500 cal BC that this landscape was completely cleared, except for the marshy-sedge fringe of the floodplain, and that colluvial sedimentation began in earnest associated with increased arable agriculture, a situation that continued through Roman and historic times

Does the Loan and Storage Program Support Corn Prices?

Market prices of corn in recent years have been falling below the loan ( support ) rate. Some attribute this to the large stocks which have built up. Research evidence, however, indicates not necessarily

The demise of the Parliament’s Political and Constitutional Reform Comittee: executive power is again predominant

Just how strong is the Conservatives mandate? With only 24.7% of eligible voters opting to support them, perhaps not as strong as their majority might suggest. One of their first moves has been to abolish the House of Commons Political and Constitutional Reform Committee, a key organ of democracy in the struggle to improve British democracy. Here, the most recent Chair of the Committee Graham Allen MP, Martin Smith, and Dave Richards argue that the whole affair illustrates an indulgence of executive power over the legislature

Molecular and serological evidence of flea-associated typhus group and spotted fever group rickettsial infections in Madagascar

This research was supported by the Wellcome Trust (RCDF and Senior Fellowship to ST, #081705 and #095171), the Institut Pasteur de Madagascar, and the Global Emerging Infections Surveillance and Response System, a Division of the Armed Forces Health Surveillance Center [847705.82000.25GB.A0074].Peer reviewedPublisher PD

The Grain-Storage Picture

Grain storage and the capacity for it have grown rapidly in the past 10 years, and there\u27s much interest in the cost of the over-all operation. Here\u27s a brief summary of the situation-nationally and here in Iowa