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The boreal biome is characterised by extensive wildfires that frequently burn into the thick organic soils found in many forests and wetlands. Previous studies investigating surface fuel consumption generally have not accounted for variation in the properties of organic soils or how this affects the severity of fuel consumption. We experimentally altered soil moisture profiles of peat monoliths collected from several vegetation types common in boreal bogs and used laboratory burn tests to examine the effects of depth-dependent variation in bulk density and moisture on depth of fuel consumption. Depth of burning ranged from 1 to 17cm, comparable with observations following natural wildfires. Individually, fuel bulk density and moisture were unreliable predictors of depth of burning. However, they demonstrated a cumulative influence on the thermodynamics of downward combustion propagation. By modifying Van Wagner’s surface fuel consumption model to account for stratigraphic changes in fuel conditions, we were able to accurately predict the maximum depth of fuel consumption for most of the laboratory burn tests. This modified model for predicting the depth of surface fuel consumption in boreal ecosystems may provide a useful framework for informing wildland fire management activities and guiding future development of operational fire behaviour and carbon emission models. [ABSTRACT FROM AUTHOR]

Background:Hyperthyroidism of Graves'' disease is caused by auto-antibodies to human thyrotropin receptor (hTSH-R). To elucidate important T-cell epitopes in TSH-R, we studied three models of immunity to TSH-R in mice.Methods:Mice transgenic for histocompatibility leukocyte antigen DR3 or DR2 were immunized with cDNA for hTSH-R-extracellular domain (hTSH-R-ECD), or hTSH-R-ECD protein, or hTSH-R peptide epitopes. Proliferative responses of immunized splenocytes to epitopes derived from the hTSH-ECD sequence, anti-TSH-R antibody responses, serum thyroxine and TSH, and thyroid histology were recorded.Results:DR3 mice responded to genomic immunization with proliferative responses to several epitopes, which increased in intensity and spread to include more epitopes, during a 6-week immunization program. DR2 transgenic mice developed weak proliferative responses. Both types of mice developed anti-TSH-R antibodies measured by enzyme-linked immunosorbent assay or TSH-binding inhibition assay in 16–60% of animals. There was evidence of weak thyroid stimulation in one group of animals. Immunization of DR3 transgenic mice to hTSH-R-ECD protein induced a striking response to an epitope with sequence ISRIYVSIDVTLQQLES (aa78–94). Immunization to peptides derived from the TSH-R-ECD sequence (including aa78–94) caused strong responses to the epitopes, and development of immune responses to several other nonoverlapping epitopes within the hTSH sequence (epitope spreading) and antibodies reacting with hTSH-R. This implies that immunization with hTSH-R epitopes produced immunity to mouse TSH-R.Conclusion:T-cell and B-cell responses to genetic immunization differ in DR3 and DR2 transgenic mice, and there is less genetic control of antibody than of T-cell responses. During both genomic and peptide epitope immunization there was evidence of epitope spreading during the immunization. Several functionally important epitopes are evident, especially aa78–94. However, if similar progressive epitope recruitment occurs in human disease, epitope-based therapy will be difficult to achieve. [ABSTRACT FROM AUTHOR]

Abstract  Targeting the epidermal growth factor receptor (EGFR) may be effective in a subset of glioblastoma patients. This phase II study assessed the clinical activity of erlotinib plus carboplatin and to determine molecular predictors of response. The primary endpoint was progression free survival (PFS). Patients with recurrent glioblastoma with no more than two prior relapses received carboplatin intravenously on day 1 of every 28-day cycle (target AUC of 6 mg × ml/min). Daily erlotinib at 150 mg/day was dose escalated to 200 mg/day, as tolerated. Clinical and MRI assessments were made every 4 and 8 weeks, respectively. Tumor tissue was evaluated for EGFR, AKT and phosphatase and tensin homolog (PTEN) status. One partial response (PR) was observed out of 43 assessable patients. Twenty patients (47%) had stable disease (SD) for an average of 12 weeks. Median PFS was 9 weeks. The 6-month PFS rate was 14%. Median overall survival (OS) was 30 weeks. This regimen was well tolerated with grade 3/4 toxicities of fatigue, leukopenia, thrombocytopenia and rash requiring dose reductions. A recursive partitioning analysis (RPA) predicted that patients with KPS ≥90 treated with more than 1 prior regimen had the highest OS. No correlation was observed between EGFR, Akt or PTEN expression and either PFS or OS. Carboplatin plus erlotinib is well tolerated but has modest activity in unselected patients. Future trials should be stratified based on optimal molecular or clinical characteristics. [ABSTRACT FROM AUTHOR]

Grass moisture and ignition studies were conducted in central Sumatra, Indonesia, to develop an indicator of grass ignition potential using the Fine Fuel Moisture Code (FFMC) of the Canadian Forest Fire Weather Index System. Moisture content of live and dead grass was measured at three sites every 6 days over an 8-month period. Grass curing was highly variable but averaged 37?39% and often exceeded 50% from April to mid-August. Grass fuel loads averaged 420?722 g/m2. There was a highly significant decrease in dead grass moisture content with increasing FFMC, decreasing grass height, and decreasing total grass biomass. The FFMC was the most influential factor, explaining 54?61% of the dead grass moisture content variation. Ignition tests were applied to live and dead grass samples with specific moisture contents. The ignition threshold of dead and live grass occurred at 35.4% and 27.8% moisture content, respectively. The dead grass ignition threshold corresponded to FFMC values of 81.0?83.3 at the three study sites. Of historical hot spots in South-east Asia, 86% occurred when the FFMC was ?78, representing the lower 95% confidence interval of the dead grass ignition threshold. The FFMC was calibrated using experimental results for fire management applications. [ABSTRACT FROM AUTHOR]

No Heading Recently, a superconductive reference device, SRD1000, with ten reference materials has been developed to enable simplified in situ calibration of interpolating thermometers. We report on the evaluation of SRD1000 prototypes at various laboratories. The devices were built and tested by HDL and KOL, calibrated at NMi-VSL and then distributed to other partners where they were re-calibrated against the local realisations of the PLTS-2000 or laboratory scales. As a result, we obtained data on the superconductive transition temperatures, widths and shapes for four different devices. Reproducibility, sharpness of the transitions, supercooling and sensitivity to magnetic fields are evaluated. This leads to estimates of the uncertainty in determination of the transition midpoint and temperature. [ABSTRACT FROM AUTHOR]

Betula glandulosa survives over a wide range of North American fire regimes by resprouting from the rhizome. Over-winter root carbohydrate reserves are important to sprout production and growth in the following spring. Nursery and field experiments were conducted to examine the effects of seasonal clipping and fire severity (lethal heat applied to different soil depths) on B. glandulosa sprouting and growth, and seasonal burning and clipping on over-winter root carbohydrate storage. Low fire severity increased sprout numbers, and low fire severity in spring caused a large increase in height growth and above-ground biomass production over a 2-year period. Mortality rates increased sharply with higher levels of fire severity. Over-winter total non-structural carbohydrate (TNC) concentrations in roots were significantly higher in plants burned immediately after leaf-flush than in mid-summer burned plants. None of the other seasonal burning or clipping treatments significantly influenced over-winter root TNC. Post-disturbance sprout growth reflected over-winter root TNC levels. B. glandulosa survives a wide range of fire frequencies by growing in plant communities that are most likely to burn in spring or autumn, and seldom burn in summer. This provides the greatest opportunity for maximum over-winter TNC storage. As well, high soil moisture after snowmelt ensures spring fires are almost always of low severity, which promotes increased sprout production, height growth and above-ground biomass. [ABSTRACT FROM AUTHOR]

Abstract Longitudinal lesions in menisci are among the most frequent orthopedic problems of the knee. Repair by simple techniques is only limited to the vascular part of the meniscus. For repair of the avascular part of the meniscus a scaffold, which will assist the body in the formation of new meniscus cell tissue, might be applicable. In this study a biomedical segmented polyurethane with poly(ɛ-caprolactone) as soft segment and 1,4-butanediisocyanate and 1,4-butanediol as uniform hard segments has been synthesised. The material has a micro phase separated morphology and excellent mechanical properties. A porous scaffold was prepared via a combination of liquid–liquid phase separation and salt leaching. The foams prepared combined a very high interconnectivity and porosity with the desired compression modulus. After six months of implantation in the knees of beagles full ingrowth with cells was obtained and it was found that meniscus like tissue had been formed in the scaffold. Moreover, compression behaviour appeared to be comparable to native meniscus tissue. [ABSTRACT FROM AUTHOR]

Oral feeding of proteins causes peripheral T-cell tolerance, as revealed by reduced delayed-type hypersensitivity (DTH) reactivity after immunization. This type of tolerance can be due both to passive T-cell anergy and active immunosuppression. Using ovalbumin-fed mice we studied whether putatively immunostimulatory cytokines could break this state of mucosal tolerance. Cytokines were administered locally at the site of attempted sensitization. It was found that neither interleukin-2 (IL-2), interferon-γ (IFN-γ) nor granulocyte-macrophage colony-stimulating factor (GM-CSF) could restore the response to immunization. In contrast, local administration of IL-12 at the site of attempted immunization resulted in full recovery of DTH reactivity. The dichotomy between the two Th1 stimulatory cytokines IFN-γ and IL-12 was also reflected by different effects on ovalbumin-specific antibody isotypes. Although both IFN-γ and IL-12 downregulated serum IgG1-levels in tolerant mice, suggesting decreased ovalbumin-specific Th2 function, only local administration of IL-12 led to increased serum IgG2a levels. These results support the view that potentiation of Th1 effector function is critical for reversal of mucosal tolerance. [ABSTRACT FROM AUTHOR]

Exchange-coupled hard and soft magnetic layers find extensive use in data storage applications, for which their dynamical response has great importance. With bulk techniques, such as ferromagnetic resonance (FMR), it is difficult to access the behaviour and precise influence of each individual layer. By contrast, the synchrotron radiation-based technique of x-ray detected ferromagnetic resonance (XFMR) allows element-specific and phase-resolved FMR measurements in the frequency range 0.5–11 GHz. Here, we report the study of the magnetization dynamics of an exchange-coupled Ni0.81Fe0.19 (43.5 nm)/Co0.5Fe0.5 (30 nm) bilayer system using magnetometry and vector network analyser FMR, combined with XFMR at the Ni and Co L2 x-ray absorption edges. The epitaxially grown bilayer exhibits two principal resonances denoted as the acoustic and optical modes. FMR experiments show that the Kittel curves of the two layers cannot be taken in isolation, but that their modelling needs to account for an interlayer exchange coupling. The angular dependence of FMR indicates a collective effect for the modes of the magnetically hard CoFe and soft NiFe layer. The XFMR precessional scans show that the acoustic mode is dominated by the Ni signal with the Co and Ni magnetization precessing in phase, whereas the optical mode is dominated by the Co signal with the Co and Ni magnetization precessing in anti-phase. The response of the Co signal at the Ni resonance, and vice versa, show induced changes in both amplitude and phase, which can be ascribed to the interface exchange coupling. An interesting aspect of phase-resolved XFMR is the ability to distinguish between static and dynamic exchange coupling. The element-specific precessional scans of the NiFe/CoFe bilayer clearly have the signature of static exchange coupling, in which the effective field in one layer is aligned along the magnetization direction of the other layer. [ABSTRACT FROM AUTHOR]