Tine options for alleviating compaction in wheelings

Repeated trafficking and harvesting operations lead to high levels of compaction in inter-row wheelings used in asparagus (Asparagus officinalis) production. This reduces soil porosity and infiltration resulting in water ponding on the soil surface. Even on gently sloping land this can result in runoff generation and an increased risk of soil erosion. A winged tine (WT) is currently used by a leading asparagus grower to loosen compacted inter-row wheelings. In order to test the effectiveness of this tine for alleviating compaction and implications for runoff and soil erosion control, it was evaluated alongside several other tine configurations. These were a narrow tine (NT); a narrow tine with two shallow leading tines (NSLT); a winged tine with two shallow leading tines (WSLT); and a modified para-plough (MPP). Testing was conducted under controlled conditions on a sandy loam soil in the Soil Management Facility at Cranfield University, Bedfordshire, UK. Tine performance was assessed at 3 depths (175, 250 and 300 mm) by draught force; soil disturbance (both above and below ground); specific draught for a given level of soil disturbance; surface roughness; and estimated change in soil bulk density. The effectiveness of tines for compaction alleviation and potential for mitigating runoff and soil erosion varied with depth. The most effective tines were found to be the MPP NSLT and the WSLT at 175 mm, 250 mm and 300 mm depth, respectively

“How did I not know any of this?” Teaching Reproductive Justice in an Abortion Desert

Reproductive justice is often used interchangeably with reproductive rights and reproductive health, overshadowing the importance of each movement’s contributions to understanding bodily autonomy. I am a former abortion care worker, now faculty at a Lutheran liberal arts college in an abortion desert. Antiabortion events on campus motivated students to request evidence-based education about reproductive issues, leading me to develop an immersive reproductive justice course. Reproductive justice is a framework that analyzes how systems of power prevent equitable access to and enjoyment of rights and health. The course examined how multifaceted oppressions shape reproductive self-determination and included content about abortion, adoption, childbirth, parenting, sterilization, and other topics. Learning about reproductive justice at a religiously affiliated institution in an abortion desert amplified the relevance of reproductive autonomy for students, exposing the lacuna of information most came to college with. Reflective teaching strategies helped students apply course concepts to their lived experiences

Custodians of contemporary pluralism? Acas' evolving role in addressing conflict during a time of economic and regulatory flux

AbstractThis paper charts the development of Acas over the last two decades as it responds to the changing context of British employment relations. While dispute resolution services have evolved to focus on individual disputes, Acas has remained true to its pluralist roots through its training and advisory services that continue to promote ‘good employment relations’

Development of Optimization Systems Analysis Technique for Texas Water Resources

This report summarizes the results of the research project, Development of Optimization - Systems Analysis Techniques for Texas Water Resources. Several analytical models which were obtained and modified for use in evaluating water resource problems are described. A method for evaluating the optimum blend of water from two or more reservoirs to meet several concurent quality criteria is presented. The special importance of estuarine analysis methods relating to water quality is outlined and two models are presented one for a steady state dispersion of wastes in partially mixed estuaries and the other an optimization xcheme using linear systems analysis to determine the optimum waste loads into an estuarine system under a variety of constraints. Interbasin transfer of water is examined and one plan evaluated to demonstrate teh use of analytical models for streamflow evaluation, field determination and reservoir simulation. The use of a Leontif input-output model to predict economic growth asa function of resource use is developed and an example presented using the area affected by the Blackburn Crossing Reservoir in East Central Texas

Chronicles of HBV and the Road to HBV Cure

Chronic hepatitis B remains a major public health concern and a leading cause of morbidity and mortality worldwide, specifically through its causative role in chronic liver disease and hepatocellular carcinoma. Worldwide, it affects up to 292 million people. In this paper, we review the historic discovery of the hepatitis B virus and chronicle the significant advances in our understanding of the virus and its interactions with the human host to cause disease. We also overview advancements in therapies for hepatitis B virus and the current absence of curative therapies and highlight on-going therapeutic efforts in search of curative therapies to control transmission and eradicate hepatitis B virus

Symptomatology and health attitudes of chronic hepatitis B patients in the USA

This study was conducted to understand the symptomatology, attitudes, and behaviours of chronic hepatitis B (CHB) patients in the USA. CHB patients enrolled in this study were recruited through multiple methods, including newspaper advertisements. Interviews were conducted in multiple languages, and all participants had a history of CHB infection for at least 6 months. Patients with documented human immunodeficiency virus or hepatitis C virus coinfection were excluded from data analyses, resulting in a total study population of 258 respondents who completed interviews between April and June 2004. The majority of monoinfected patients were male (57%) and non-Asian (92%, including 52% Caucasian, 32% African American and others). Length of diagnosis was 5.8 years for all participants (9.1-year Asian and 5.1-year non-Asian). Ninety-five per cent of CHB patients reported symptoms of differing severity in the 12 months prior to the survey. The most common symptoms included fatigue/loss of energy (90%) and loss of appetite (79%). Non-Asian patients described greater symptomatology, and were more likely than Asians to consider CHB an overriding concern in their daily activities. Patients were treated either currently or previously with interferon (IFN) described greater symptomatology than those treated without IFN. Survey results indicate that CHB patients may have greater symptomatology than recognized. Disease perceptions and treatment attitudes differ between Asian and non-Asian ethnic groups, with the former appearing to be more accepting and less concerned about the disease. Additional research about CHB symptomatology and health attitudes by ethnicity is needed to ensure that individuals with CHB are educated on the potential health risks and the availability of current treatment options

Daily enteral feeding practice on the ICU: attainment of goals and interfering factors

BACKGROUND: The purpose of this study was to evaluate the daily feeding practice of enterally fed patients in an intensive care unit (ICU) and to study the impact of preset factors in reaching predefined optimal nutritional goals. METHODS: The feeding practice of all ICU patients receiving enteral nutrition for at least 48 hours was recorded during a 1-year period. Actual intake was expressed as the percentage of the prescribed volume of formula (a success is defined as 90% or more). Prescribed volume (optimal intake) was guided by protocol but adjusted to individual patient conditions by the intensivist. The potential barriers to the success of feeding were assessed by multivariate analysis. RESULTS: Four-hundred-and-three eligible patients had a total of 3,526 records of feeding days. The desired intake was successful in 52% (1,842 of 3,526) of feeding days. The percentage of successful feeding days increased from 39% (124 of 316) on day 1 to 51% (112 of 218) on day 5. Average ideal protein intake was 54% (95% confidence interval (CI) 52 to 55), energy intake was 66% (95% CI 65 to 68) and volume 75% (95% CI 74 to 76). Factors impeding successful nutrition were the use of the feeding tube to deliver contrast, the need for prokinetic drugs, a high Therapeutic Intervention Score System category and elective admissions. CONCLUSION: The records revealed an unsatisfactory feeding process. A better use of relative successful volume intake, namely increasing the energy and protein density, could enhance the nutritional yield. Factors such as an improper use of tubes and feeding intolerance were related to failure. Meticulous recording of intake and interfering factors helps to uncover inadequacies in ICU feeding practice

Optimal Operation of Large Agricultural Watersheds with Water Quality Restraints

Improved technology is needed for use in properly managing large agricultural watersheds. Proper watershed management means selecting land uses that are appropriate for each subarea, using erosion control measures where necessary, and applying fertilizers at rates that maximize agricultural production without polluting the environment. Watershed runoff and industrial and municipal effluents pollute streams and reservoirs. Point source pollution (industries and municipalities) can be monitored. Nonpoint-source pollution (watersheds) is widely dispersed and not easily measured. Mathematical models are needed to predict nonpoint-source pollution as affected by watershed characteristics, land use, conservation practices, chemical fertilizers, and climatic variables. Routing models are needed to determine the quality of water as it flows from nonpoint sources through streams and valleys to rivers and large reservoirs. Models are also needed to determine optimal strategies for planning land use, conservation practices, and fertilizer application to maximize agricultural production subject to water quality constraints. Three of the most important agricultural pollutants are suspended sediment, phosphorus, and nitrogen. Robinson [1971] pointed out that sediment is the greatest pollutant of water in terms of volume. Sediment also transports other pollutants, like phosphorus and nitrogen. These two elements are principally involved in lake eutrophication. Frequently algae blooms develop in nutrient-laden water and cause it to have an off-taste and an unpleasant odor. The odor of decaying plants becomes offensive; fish are killed because of reduced dissolved oxygen in the water, and recreation is deterred. The objective of this research was to develop models for use in managing large agricultural watersheds to obtain maximum agricultural production and to maintain water quality standards. The models were designed to: 1. Simulate daily runoff, and sediment, phosphorus, and nitrogen yields from small watersheds (areas < 40 km2) and determine frequency relationships. 2. Route various frequency hydrography and sediment, phosphorus, and nitrogen yields from subwatersheds through streams and valleys of large agricultural watersheds (areas < 2500 km2) to obtain frequency relationships at the entrance of a river or reservoir. 3. Determine strategies that are acceptable to the decision makers (land owners and operators) for planning land use, fertilizer application, and conservation practices on subwatersheds. 4. Determine the optimal strategy for each subwatershed to maximize agricultural production for the entire watershed subject to water quality constraints. Generally, water-quality models are developed by adding chemical modeling components to existing runoff and sediment models because runoff and sediment provide transportation for chemicals. Several conceptual models for predicting chemical yields from small watersheds have been presented [Crawford and Donigian, 1973; Donigian and Crawford, 1976; Frere, et al., 1975; Hagin and Amberger, 1974; Kling, 1974; Johnson and Straub, 1971]. However, these models are not applicable to large watersheds because they have no routing mechanism. For this reason, runoff, sediment, and nutrient models were refined and developed here for application to large watersheds. Probably, the most widely used and accepted model for predicting runoff volume is the Soil Conservation Service (SCS) curve number system [U.S. Soil Conservation Service, 1972]. The SCS model was modified by adding a soil-moisture-index accounting procedure [Williams and Laseur, 1976]. The modified water yield model is considerably more accurate than the original SCS model. On a watershed near Riesel, Texas, the modified model explained 95% of the variation in monthly runoff as compared with 65% for the original model. The water-yield model was refined here by replacing the climatic index (lake evaporation) with daily consumptive water use for individual crops. Besides predicting individual storm runoff volumes, it is also necessary to predict hydrographs and to perform flood routing for water quality modeling on large agricultural watersheds. HYMO, a problemoriented computer language for building hydrologic models [Williams and Hann, 1973] was selected to compute hydrographs and perform flood routings. Worldwide use has shown that HYMO is convenient and reliable for extremely varied hydrologic conditions. The Variable Travel Time (VTT) flood routing method [Williams, 1975a] used in HYMO is about as accurate as an implicit solution of the unsteady flow equations of continuity and motion and is free of convergence problems. The USLE [Wischmeier and Smith, 1965] is the most widely used and accepted erosion model. It can be used to predict long-term average annual sediment yields for watersheds by applying a delivery ratio. However, the USLE was not designed for application to individual storms and is, therefore, not appropriate for individual storm water quality modeling. The USLE was modified [Williams, 1975c] by replacing the rainfall energy factor with a runoff factor. The modified universal soil loss equation (MUSLE) increased sediment-yield-prediction accuracy, eliminated the need for delivery ratios, and is applicable to individual storms. In tests with data from Riesel, Texas; Chickasha, Oklahoma; Oxford, Mississippi; Treynor, Iowa; Hastings, Nebraska; and Boise, Idaho, MUSLE generally explained 80% or more of the variation in individual storm sediment yield for each watershed. These tests included 60 watersheds with areas ranging from 0.01 to 234 km2 and slopes ranging from less than 1 to about 30%. The MUSLE was combined with the modified SCS water-yield model and HYMO to form a daily runoff-sediment prediction model [Williams and Berndt, 1976]. Satisfactory results were obtained when the runoff-sediment model was tested with data from 26 watersheds in Texas. The MUSLE is useful in predicting sediment yield from small watersheds (area < 40 km2), but sediment routing is needed to maintain prediction accuracy on large watersheds with nonuniformly distributed sediment sources. A sediment routing model was developed for large agricultural watersheds [Williams, 1975b] and has had limited testing. The sediment routing model was refined here and combined with nutrient-loading functions to develop a sediment-phosphorus-nitrogen routing model. Nitrogen and phosphorus loading functions [McElroy, et al., 1976] were developed for use on small agricultural watersheds. The loading functions were designed for predicting long-term average annual phosphorus and nitrogen yields based on predicted sediment yield, nutrient concentration in the soil, and enrichment ratios. However, there is no provision for predicting nitrate yield, since it is not attached to the sediment. There are no functions provided for determining nutrient concentrations in the soil as affected by fertilizer application. Also, relations were not developed for predicting enrichment ratios. Here the loading functions were adapted to individual storm prediction of phosphorus and nitrogen yields from small watersheds. A nitrate component was added and the enrichment ratios were related to particle-size distributions of the soil and the sediment. Since water quality models are not well developed for large agricultural watersheds, little has been done to develop models to determine optimal watershed management strategies subject to water quality constraints. Onishi and Swanson [1974] used linear programming to determine crop systems and practices that are economically optimal on a 4.86-km2 watershed subject to sediment and nitrogen constraints. Wade, et al. [1974] described a model that uses linear programming to minimize national agricultural production costs subject to meeting agricultural production demands and sediment yield constraints. Miller and Gill [1976] used a linear programming model to maximize net revenue to farm firms constrained by acreage limits and soil loss limits. Heady [1976] developed a national model to minimize the cost of producing and transporting farm commodities subject to soil loss and other constraints. None of these models are directly applicable to large agricultural watershed management, because only soil loss or nutrient losses are considered constraints. By including routing models, yields of sediment, phosphorus, and nitrogen can be determined and used as constraints. Considering yields to rivers or reservoirs provides more flexibility in management and higher potential agricultural production for the large watershed. Soil loss may not contribute to pollution because it may never reach a point to cause damage (permanent stream or reservoir). Yields of sediment, nitrogen, and phosphorus depend upon location of the source within a watershed, hydraulic efficiency of the channels, and the particle-size distribution as well as soil loss. If only soil loss is considered as a constraint, agricultural production cannot be truly maximized. The model presented here uses linear programming to maximize agricultural utility subject to constraints of sediment, phosphorus, and nitrogen yields at the watershed outlet. Decision analysis, as described by Raiffa [1970], is used to determine strategies that are acceptable to the decision makers (landowners and land operators) and to calculate the utility of the strategies. A strategy specifies land use, fertilization rate, and conservation practice. Utility is described with a multiattribute utility function based on gross income, production cost, dependability, and disease, insect, and weed control. Utility theory expresses the decision makers' preferences on a scale from zero to one. This provides for easier and clearer decisions because attributes with various units can be compared and combined directly. To apply decision analysis, each subwatershed is subdivided according to land capability classes. This simplifies the selection of strategies for the decision maker because different land classes have different production and pollution potentials. The number of possible strategies for operating each land capability class within a subwatershed approaches infinity, but the number can be reduced greatly by considering only strategies that are acceptable to the decision makers. Generally, crop production records are not adequate to evaluate the attributes for all strategies. However, the analyst or modeler can evaluate the attributes through the use of subjective probability distributions. Raiffa [1970] suggested special techniques for developing subjective probability distributions by interviewing the decision makers. Each year as the crops are harvested, the probability distributions are revised using Bayes' Theorem [1763] to include the observed data. Since there is usually more than one decision maker per subwatershed, most decisions concerning utility functions and probability distributions are group decisions. Raiffa [1970] suggested using Pareto-optimality in making group decisions. A joint action is Pareto-optimal if no alternative action exists that is at least as acceptable to all and definitely preferred by some. Decision analysis has been used very little in water-resources planning. McCuen [1973] used decision analysis to determine benefits from recreation facilities; Dean and Shih [1973] showed the advantages of subjective decision making for urban water resources development; and Russell [1974] applied decision theory to reservoir operation