The Costs and Returns of Scottish Potato Production

The gross and net margins for a representative sample of 53 Scottish potato producers classed as "Seed" (>80% of area grown for seed), "Ware" (>80% of area grown for Ware) and "Mixed" for the rest were obtained for the 1999 growing season according to the methodology of MAFF (1990,1999). The farms were arable. Yields were average but for seed growers for whom tuber number in the seed size is more important. Prices were the lowest for six years variable costs were high and gross margins are above the best for cereals. However fixed costs excluding seasonally rented land are considerable leaving negative net margins. Potato price fluctuates widely. Prices were high in 1998. Applying these prices to the 1999 data left good net margins. Average prices still left reasonable net margins. Break-even prices were £85/t for ware and £200/t for seed, which were not reached in three of the last six years. These results show the considerable investment in both fixed and variable costs and risk for this important Scottish crop.Crop Production/Industries,

Superintendents and Professional Development: Voices from the Field

The primary task of the educational leader is to assure high quality learning environments for all students. Research (Gordon, 2004; Sparks, 2007) supports the proposition that effective professional development contributes to instructional improvement by building educator capacity. Much of the research on professional development focuses in principal leadership in improving instruction (Blase & Blase, 2004). But district level administrators, especially the superintendent of schools, also have a role to play in school improvement. Standards for the preparation of school leaders specify competencies for superintendents that include the design and implementation of professional development programs based on sound research, best practices, district-and school-level data, and other contextual information (National Policy Board, 2002). The National Staff Development Council\u27s Standards (2001) also describe a comprehensive set of activities to improve student learning that apply to both campus and district level personnel. But while the research on the instructional leadership role of principals is extensive, comparatively little is said about how superintendents meet their own responsibilities in this area (Dufour, 2000; Hirsch, 2009; Firestone, Manquin, & Martinez, 2005)

Effect of Farm-Level Constraints, Existing and Prospective Policies on Expansion of Coconut-Based Intercropping in Sri Lanka

Coconut-based intercropping (CBI) in Sri Lanka was introduced some 20 years ago to overcome the two main limitations of traditional coconut monocropping, inefficient land use and low incomes to farmers, but it has not been widely adopted. This study analyses the effect of farm-level resource constraints, and government policies on the intensity of adoption of CBI. A multiperiod linear programming (MLP) model was applied for three farmer groups - resource poor, medium endowed, well endowed - categorised using cluster analysis. Data was collected from a survey of randomly selected 113 intercroppers. Empirical results reveal that expansion of CBI is mainly constrained by seasonal labour shortages for all farmer groups, particularly the well endowed, and by the scarcity of cash in the case of resource-poor farmers. CBI policies aimed at subsidising inputs or intercrop prices are not likely to be efficient in raising adoption, but alternative policies aimed at alleviating resource constraints would be more effective. The study concluded that the low adoption of CBI is mainly attributable to the scarcity of different farm-level resources (other than land), at varying degrees among different farmer groups. Hence a targeted approach to alleviate them is suggested.Crop Production/Industries,

The inclusions afforded by a value-led design process for technology-nature hybrids in a walled kitchen garden

This paper describes the importance of a values-led approach within a design collaboration in a National Trust garden in Nottinghamshire, UK. The project demonstrates the power of values to shape not only the designed artefacts but the whole design process. The work responds to reports from the National Trust and other organizations of people’s increased disconnection from the natural world, and seeks to challenge the perception that technology is instrumental in fueling such detachment. The primary contribution of our value-based and critically engaged design process is the creation of prototypes that embody values and act as a focal point for reflection and re-encounter by the stakeholder organization. A process that itself acts as a continuous prompt for renewed consideration of interpretation approaches and organizational messages. The research involves the design of technology-nature hybrids for interpretation of a Walled Kitchen Garden, to support connection to nature. Designs are grounded in organizational values drawn from National Trust and researcher- designer values drawn from critical theory of technology. The project explores an area of intersecting and overlapping values and discusses the tensions experienced working in this space. The project illustrates how the inclusion of values and critical philosophy opens up new possibilities for the use of materials and technologies to increase our connection to nature

High throughput sequencing in acute lymphoblastic leukemia reveals clonal architecture of central nervous system and bone marrow compartments

No abstract available

Schematics of a Water Balloon Launcher Design and Reproducible Water-Balloon-Filling Procedures Used for a Middle School Summer Science Camp

We recently held a Science Summer Camp for middle school students, designed to infuse young people with increased excitement for STEM (Science, Technology, Engineering, and Math) subjects. Our efforts, which received nationally-syndicated news coverage,1 included the invention of a versatile water balloon launcher. This document contains: (1) detailed construction schematics and user operation guidelines for our balloon launcher; (2) data and instructions for reproducibly filling water balloons to specific volumes and weights, within used by students during the summer camp

Smoothing tautologies, hidden dynamics, and sigmoid asymptotics for piecewise smooth systems

Switches in real systems take many forms, such as impacts, electronic relays, mitosis, and the implementation of decisions or control strategies. To understand what is lost, and what can be retained, when we model a switch as an instantaneous event, requires a consideration of so-called hidden terms. These are asymptotically vanishing outside the switch, but can be encoded in the form of nonlinear switching terms. A general expression for the switch can be developed in the form of a series of sigmoid functions. We review the key steps in extending the Filippov's method of sliding modes to such systems. We show how even slight nonlinear effects can hugely alter the behaviour of an electronic control circuit, and lead to `hidden' attractors inside the switching surface.Comment: 12 page