How can organic agriculture contribute to long-term climate goals?

The EU countries aim to reduce their emissions of greenhouse gases (GHG) by 80-95% by 2050 (European Commission, 2011). The food sector accounts today for 25% of Swedish greenhouse gas emissions, most of which arise in agricultural production, so there is a need for radical reduction of GHG emissions in this sector. For organic farming in Sweden, this implies that it is time to move beyond the discussion on whether organic products have a lower or higher life-cycle climate impact than conventional products (Cederberg et al 2011). Instead, the interesting question is: What can and should be done to drastically reduce the climate impact of organic agriculture? The science-based response to that question is relevant for Swedish agriculture as a whole. Development towards lower climate impact from organic agriculture requires further monitoring and technology development to reduce emissions of nitrous oxide, methane and carbon dioxide. But it also involves developing production systems that are more efficient in the use of nutrients, energy and land, as well as shifting focus from producing animal food towards more legume, grain, vegetable and fruit products

Organic farming without fossil fuels - life cycle assessment of two Swedish cases

Organic agriculture is dependent on fossil fuels, just like conventional agriculture, but this can be reduced by the use of on-farm biomass resources. The energy efficiency and environmental impacts of different alternatives can be assessed by life cycle assessment (LCA), which we have done in this project. Swedish organic milk production can become self-sufficient in energy by using renewable sources available on the farm, with biogas from manure as the main energy source. Thereby greenhouse gas (GHG) emissions from the production system can be reduced, both by substituting fossil fuels and by reducing methane emissions from manure. The arable organic farm studied in the project could be self-sufficient in energy by using the residues available in the crop rotation. Because of soil carbon losses, the greenhouse gas emission savings were lower with the use of straw ethanol, heat and power (9%) than by using ley for biogas production (35%). In this research project, the system boundaries were set at energy self-sufficiency at farm or farm-cluster level. Heat and fuel were supplied as needed, and electricity production was equal to use on an annual basis. In practice, however, better resource efficiency can be achieved by making full use of available energy infrastructure, and basing production on resource availability and economic constraints, rather than a narrow self-sufficiency approach

Frequency domain model for analysis of paralleled, series-output-connected Mapham inverters

The Mapham resonant inverter is characterized as a two-port network driven by a selected periodic voltage. The two-port model is then used to model a pair of Mapham inverters connected in series and employing phasor voltage regulation. It is shown that the model is useful for predicting power output in paralleled inverter units, and for predicting harmonic current output of inverter pairs, using standard power flow techniques. Some examples are compared to data obtained from testing hardware inverters

Preservation of vaccine-induced long-term B cell memory and the effects of immunosuppressive treatment

Immune memory after vaccination is largely dependent on the combination of antibody production from long-lived plasma cells, and a supporting pool of antigen-primed memory B cells. It has been observed that individuals with certain immunosuppressive conditions or treatments have a weakened B cell memory, but the mechanisms behind remain elusive. The aim of this thesis was to evaluate B cell immunity in healthy children, and how HIV-1 infection, antineoplastic therapy, and rheumatic disease and treatment can impact on various features of B cell memory induction and maintenance. In paper I, we explored the hyperactivation of B cells observed in patients carrying HIV-1 infection, and showed that it can be partly induced by ligation of soluble cleaved CD27 to CD70 on the surface of memory B cells. In paper II, we aimed at comparing the establishment of serum antibody titers and memory B cells after vaccination against measles and rubella in healthy children. We found that the memory B cell pool remained stable also early after vaccination, whereas the corresponding serum IgG titers decayed with time. In contrast, both the serum IgG levels and frequency of blood memory B cells in healthy young adults appeared stable. This implied that the antibody production and memory B cell compartment are two separate entities with independent regulation, and that it takes longer time to establish a stable pool of circulating antibodies. How these two parts of B cell memory are affected by immunosuppressive disease and treatment was addressed in papers III and IV. In paper III, we used a rhesus macaque model for high-dose Doxorubicin treatment, and concluded that the established vaccine-induced memory B cell pool was depleted, contrary to long-lived plasma cells and the resulting serum IgG titers. These observations supported the finding of independent regulation of the two B cell memory compartments, and revealed different sensitivity to chemotherapy. The bone marrow plasma cell niche was additionally studied in an in vitro model for plasma cell – stromal cell cross talk, where we discovered that in vivo relevant concentrations of Doxorubicin could hamper the output of pivotal survival factors from stromal cells. In paper IV, we examined memory B cells and circulating IgG titers in children with rheumatic disease, treated with low-dose Methotrexate and TNF-α inhibition. We noted that serum IgG titers against tetanus were lower in rheumatic patients than in healthy controls, and that patients who had only received one measles vaccine dose had lower levels of measles-specific memory B cells. This stresses the importance for children with rheumatic disease and treatment to follow the full vaccine schedule. To summarize, this thesis has contributed to enhanced knowledge on how B cell memory is induced, preserved and at risk of disruption by common immune disorders and treatment. Hopefully, our findings can aid future improvement of functional vaccine regimes for immunocompromised children

Muscle Fatigue from the Perspective of a Single Crossbridge

The repeated intense stimulation of skeletal muscle rapidly decreases its force- and motion-generating capacity. This type of fatigue can be temporally correlated with the accumulation of metabolic by-products, including phosphate (Pi) and protons (H+). Experiments on skinned single muscle fibers demonstrate that elevated concentrations of these ions can reduce maximal isometric force, unloaded shortening velocity, and peak power, providing strong evidence for a causative role in the fatigue process. This seems to be due, in part, to their direct effect on muscle’s molecular motor, myosin, because in assays using isolated proteins, these ions directly inhibit myosin’s ability to move actin. Indeed, recent work using a single molecule laser trap assay has revealed the specific steps in the crossbridge cycle affected by these ions. In addition to their direct effects, these ions also indirectly affect myosin by decreasing the sensitivity of the myofilaments to calcium, primarily by altering the ability of the muscle regulatory proteins, troponin and tropomyosin, to govern myosin binding to actin. This effect seems to be partially due to fatigue-dependent alterations in the structure and function of specific subunits of troponin. Parallel efforts to understand the molecular basis of muscle contraction are providing new technological approaches that will allow us to gain unprecedented molecular detail of the fatigue process. This will be crucial to fully understand this ubiquitous phenomenon and develop appropriately targeted therapies to attenuate the debilitating effects of fatigue in clinical populations

Distortion and regulation characterization of a Mapham inverter

Output voltage Total Harmonic Distortion (THD) of a 20kHz, 6kVA Mapham resonant inverter is characterized as a function of its switching-to-resonant frequency ratio, f sub s/f sub r, using the EASY5 engineering analysis system. EASY5 circuit simulation results are compared with hardware test results to verify the accuracy of the simulations. The effects of load on the THD versus f sub s/f sub r ratio is investigated for resistive, leading, and lagging power factor load impedances. The effect of the series output capacitor on the Mapham inverter output voltage distortion and inherent load regulation is characterized under loads of various power factors and magnitudes. An optimum series capacitor value which improves the inherent load regulation to better than 3 percent is identified. The optimum series capacitor value is different than the value predicted from a modeled frequency domain analysis. An explanation is proposed which takes into account the conduction overlap in the inductor pairs during steady-state inverter operation, which decreases the effective inductance of a Mapham inverter. A fault protection and current limit method is discussed which allows the Mapham inverter to operate into a short circuit, even when the inverter resonant circuit becomes overdamped

At-Risk Preschoolers Become Beginning Readers With Neurologically Integrated Alphabet Instruction

This is the author's accepted manuscript. The publisher's version is available on their website.Massengill Shaw, D., & Sundberg, M.L. (2008). At-risk preschoolers become beginning readers with neurologically integrated alphabet instruction. Journal of Education Research, 2(1), 61-73

How A Neurologically Integrated Approach Which Teaches Sound-Symbol Correspondence and Legible Letter Formations Impacts At-Risk First Graders

This is the author's accepted manuscript. The publisher's official version is available at: http://www.eric.ed.gov/PDFS/EJ942830.pdfThe setting of this study took place in an inner city. The purpose was to determine the effectiveness of a neurologically integrated approach in teaching 43 at-risk pre-first graders their letter sounds and formations during 45-50 hours of summer school. There were four sequential phases to teaching this alphabetic approach: imagery, auditory, integration and sound blending, and motor plan. Students received three pre and post-tests: sound, letter formation, and phonic knowledge as assessed through alphabet exercises and the Early Reading Screening Instrument. Repeated measures and descriptive statistics of the three assessments were used to measure growth. Results indicate that despite an average attendance of 84%, significant changes occurred in the students’ knowledge of letter sounds, letter formations and their ability to write words (phonics). It is recommended to explicitly teach at-risk children their alphabet knowledge through a neurologically integrated approach that mirrors brain development

Quantitative evaluation of ontology design patterns for combining pathology and anatomy ontologies.

Data are increasingly annotated with multiple ontologies to capture rich information about the features of the subject under investigation. Analysis may be performed over each ontology separately, but recently there has been a move to combine multiple ontologies to provide more powerful analytical possibilities. However, it is often not clear how to combine ontologies or how to assess or evaluate the potential design patterns available. Here we use a large and well-characterized dataset of anatomic pathology descriptions from a major study of aging mice. We show how different design patterns based on the MPATH and MA ontologies provide orthogonal axes of analysis, and perform differently in over-representation and semantic similarity applications. We discuss how such a data-driven approach might be used generally to generate and evaluate ontology design patterns.National Institutes of Health (AG038070-05, for the Shock Aging Center) King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. URF/1/3454-01-01 and FCC/1/1976-08-01. King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. FCS/1/3657-02-0