Validated environmental and physiological data from the CELSS Breadboard Projects Biomass Production Chamber. BWT931 (Wheat cv. Yecora Rojo)

This KSC database is being made available to the scientific research community to facilitate the development of crop development models, to test monitoring and control strategies, and to identify environmental limitations in crop production systems. The KSC validated dataset consists of 17 parameters necessary to maintain bioregenerative life support functions: water purification, CO2 removal, O2 production, and biomass production. The data are available on disk as either a DATABASE SUBSET (one week of 5-minute data) or DATABASE SUMMARY (daily averages of parameters). Online access to the VALIDATED DATABASE will be made available to institutions with specific programmatic requirements. Availability and access to the KSC validated database are subject to approval and limitations implicit in KSC computer security policies

A self-determination theory analysis of reflective debrief themes about dietetic student placement experiences in hospital: implications for education

Background. Healthcare placements in dietetics education contribute significantly to student learning. Exploring students’ self-conceptualisation of placement experiences may provide insights to better support learning. Self-determination theory (SDT) has been used to seek insight into clinical and educational settings but has not yet been applied to dietetic placement learning. This study investigated dietetics students’ reflections of key influences on placement learning experiences and their alignment with an SDT framework. Methodology. A post-placement two-stage critical incident debrief was conducted with seven successive cohorts (168 students) of dietetic undergraduate students on final placement. In debriefs, students’ anonymous themes were collected and discussed, inductively analysed, and then mapped against an SDT framework of psychological and motivational constructs. Results. Nine key themes were identified that impacted upon placement experiences. Four themes related to framework constructs: 1. Supervisor (and peer) autonomy support: 2. Perceived competence; 3. Relatedness; and, 4. Autonomy and intrinsic motivation. Non-SDT themes were also present including: 5. Learning environment and experience; and, themes about professional behaviours and identity: 6. Teamwork and interactions, 7. Managing emotions and self-care, 8. Dietetic professional communications and behaviours and, 9. Developing a professional identity. Conclusions. Embedding a structured debrief in the curriculum and using a psychological motivational SDT framework to analyse themes arising can provide valuable information about the learning needs of students on placement with potential for wider application in dietetic learning and teaching and workforce employability. The current findings may have application in university curricula before and after professional placement

Purification of hydroxylamine oxidase from Thiosphaera pantotropha Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification

AbstractThiosphaera pantotropha, a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic hydroxylamine oxidase that differs markedly from the hydroxylamine oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant

Corn Yield Potential and Optimal Soil Productivity in Irrigated Corn/Soybean Systems

In 1999, an interdisciplinary research team at the University of Nebraska established a field experiment to (1) quantify and understand the yield potential of corn and soybean under irrigated conditions, (2) identify efficient crop management practices to achieve yields that approach potential levels, and (3) determine the energy use efficiency, global warming and soil C-sequestration potential of intensively managed corn systems. The experiment compares systems that represent different levels of management intensity expressed as combinations of crop rotation (continuous corn, corn-soybean), plant density (low, medium, high) and nutrient management (recommended best management vs. intensive management). Detailed measurements include soil nutrient dynamics and C balance, crop growth and development, nutrient uptake and components of yield of corn and soybean, radiation use efficiency, soil surface fluxes of greenhouse gases, root biomass, C inputs through crop residues, translocation of non-structural carbohydrates, and amount, composition and activity of the microbial biomass. Selected results for corn are presented

Corn Yield Potential and Optimal Soil Productivity in Irrigated Corn/Soybean Systems

In 1999, an interdisciplinary research team at the University of Nebraska established a field experiment to (1) quantify and understand the yield potential of corn and soybean under irrigated conditions, (2) identify efficient crop management practices to achieve yields that approach potential levels, and (3) determine the energy use efficiency, global warming and soil C-sequestration potential of intensively managed corn systems. The experiment compares systems that represent different levels of management intensity expressed as combinations of crop rotation (continuous corn, corn-soybean), plant density (low, medium, high) and nutrient management (recommended best management vs. intensive management). Detailed measurements include soil nutrient dynamics and C balance, crop growth and development, nutrient uptake and components of yield of corn and soybean, radiation use efficiency, soil surface fluxes of greenhouse gases, root biomass, C inputs through crop residues, translocation of non-structural carbohydrates, and amount, composition and activity of the microbial biomass. Selected results for corn are presented