13 research outputs found
Creation and utilization of a World Wide Web based space radiation effects code: SIREST.
In order for humans and electronics to fully and safely operate in the space environment, codes like HZETRN (High Charge and Energy Transport) must be included in any designer's toolbox for design evaluation with respect to radiation damage. Currently, spacecraft designers do not have easy access to accurate radiation codes like HZETRN to evaluate their design for radiation effects on humans and electronics. Today, the World Wide Web is sophisticated enough to support the entire HZETRN code and all of the associated pre and post processing tools. This package is called SIREST (Space Ionizing Radiation Effects and Shielding Tools). There are many advantages to SIREST. The most important advantage is the instant update capability of the web. Another major advantage is the modularity that the web imposes on the code. Right now, the major disadvantage of SIREST will be its modularity inside the designer's system. This mostly comes from the fact that a consistent interface between the designer and the computer system to evaluate the design is incomplete. This, however, is to be solved in the Intelligent Synthesis Environment (ISE) program currently being funded by NASA
Invasive Andropogon gayanus (Gamba grass) alters litter decomposition and nitrogen fluxes in an Australian tropical savanna
What Counts as Evidence: A Review of Validity Studies in Educational and Psychological Measurement
Metabolic regulation of innate immunity to fungal infection
In recent years, the renewed interest in immune cell metabolism has driven the emergence of a research field aimed at studying the role of metabolic processes during innate and adaptive immune responses. Although the specific requirements of myeloid cells after the canonical lipopolysaccharide/TLR4 stimulation have been extensively addressed, recent evidence suggests that this model may not represent a universally accurate metabolic blueprint. Instead, different microbial stimuli, pathogens, or tissue microenvironments trigger specific and complex metabolic rewiring of myeloid cells. This chapter aims to provide an overview of the metabolic heterogeneity in activated myeloid cells during fungal disease. Directions for future research in dissecting the uniqueness of metabolic signatures during fungal infection are suggested to ultimately provide new tailored diagnostic and therapeutic interventions.(undefined)info:eu-repo/semantics/publishedVersio
Ecosystem Recovery from Disturbance is Constrained by N Cycle Openness, Vegetation-Soil N Distribution, Form of N Losses, and the Balance Between Vegetation and Soil-Microbial Processes
Tree nutrient status and nutrient cycling in tropical forest - lessons from fertilization experiments
Highly productive tropical forests often occur on nutrient-poor soils . The apparent lack of a relationship between tree growth and site fertility has generated decades of research into which nutrients, if any, limit tropical forest productivity. This chapter looks at the lessons we have learned from several decades of fertilization experiments, which investigate nutrient limitation by measuring changes in growth and productivity in response to the addition of specific nutrients. The enormous diversity of tropical forest ecosystems often confounds attempts to measure a clear ecosystem response to fertilization because tree species’ nutrient requirements differ according to life history strategy , adaptation to site fertility, and the life stage of the individuals under study. Importantly, other limiting resources, such as light and water, constrain individual responses to nutrient availability, whereas species interactions such as competition, herbivory , and symbioses can mask growth responses to nutrient amendments. Finally, fertilization changes the timing and balance of nutrient inputs to the forest, whereas litter manipulation studies demonstrate that the combined addition of many different nutrients and organic carbon minimizes nutrient losses. Most fertilization studies have investigated responses to nitrogen and phosphorus additions but there is still no general consensus on nutrient limitation in tropical forests. Future experiments will need to evaluate how the balance of multiple macro- and micronutrients affects tropical forest growth and ecosystem dynamics