Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us

Supernova remnants (SNRs) arise from the interaction between the ejecta of a supernova (SN) explosion and the surrounding circumstellar and interstellar medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However, to understand SNRs as a whole, large samples of SNRs must be assembled and studied. Here, we describe the radio, optical, and X-ray techniques which have been used to identify and characterize almost 300 Galactic SNRs and more than 1200 extragalactic SNRs. We then discuss which types of SNRs are being found and which are not. We examine the degree to which the luminosity functions, surface-brightness distributions and multi-wavelength comparisons of the samples can be interpreted to determine the class properties of SNRs and describe efforts to establish the type of SN explosion associated with a SNR. We conclude that in order to better understand the class properties of SNRs, it is more important to study (and obtain additional data on) the SNRs in galaxies with extant samples at multiple wavelength bands than it is to obtain samples of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and Paul Murdin. Final version available at https://doi.org/10.1007/978-3-319-20794-0_90-

DQB1*0602 rather than DRB1*1501 confers susceptibility to multiple sclerosis-like disease induced by proteolipid protein (PLP)

<p>Abstract</p> <p>Background</p> <p>Multiple sclerosis (MS) is associated with pathogenic autoimmunity primarily focused on major CNS-myelin target antigens including myelin basic protein (MBP), proteolipidprotein (PLP), myelin oligodendrocyte protein (MOG). MS is a complex trait whereby the HLA genes, particularly class-II genes of HLA-DR15 haplotype, dominate the genetic contribution to disease-risk. Due to strong linkage disequilibrium in HLA-II region, it has been hard to establish precisely whether the functionally relevant effect derives from the DRB1*1501, DQA1*0102-DQB1*0602, or DRB5*0101 loci of HLA-DR15 haplotype, their combinations, or their epistatic interactions. Nevertheless, most genetic studies have indicated DRB1*1501 as a primary risk factor in MS. Here, we used 'HLA-humanized' mice to discern the potential relative contribution of DRB1*1501 and DQB1*0602 alleles to susceptibility to "humanized" MS-like disease induced by PLP, one of the most prominent and encephalitogenic target-antigens implicated in human MS.</p> <p>Methods</p> <p>The HLA-DRB1*1501- and HLA-DQB1*0602-Tg mice (MHC-II^-/-), and control non-HLA-DR15-relevant-Tg mice were immunized with a set of overlapping PLP peptides or with recombinant soluble PLP for induction of "humanized" MS-like disease, as well as for ex-vivo analysis of immunogenic/immunodominant HLA-restricted T-cell epitopes and associated cytokine secretion profile.</p> <p>Results</p> <p>PLP autoimmunity in both HLA-DR15-Tg mice was focused on 139-151 and 175-194 epitopes. Strikingly, however, the HLA-DRB1*1501-transgenics were refractory to disease induction by any of the overlapping PLP peptides, while HLA-DQB1*0602 transgenics were susceptible to disease induction by PLP139-151 and PLP175-194 peptides. Although both transgenics responded to both peptides, the PLP139-151- and PLP175-194-reactive T-cells were directed to Th1/Th17 phenotype in DQB1*0602-Tg mice and towards Th2 in DRB1*1501-Tg mice.</p> <p>Conclusions</p> <p>While genome studies map a strong MS susceptibility effect to the region of DRB1*1501, our findings offer a rationale for potential involvement of pathogenic DQ6-associated autoimmunity in MS. Moreover, that DQB1*0602, but not DRB1*1501, determines disease-susceptibility to PLP in HLA-transgenics, suggests a potential differential, functional role for DQB1*0602 as a predisposing allele in MS. This, together with previously demonstrated disease-susceptibility to MBP and MOG in DRB1*1501-transgenics, also suggests a differential role for DRB1*1501 and DQB1*0602 depending on target antigen and imply a potential complex 'genotype/target antigen/phenotype' relationship in MS heterogeneity.</p

Studying Evidence Use for Health Policymaking from a Policy Perspective

Individuals working within the health sector widely embrace the idea of using evidence to achieve their goals of improving individual and population health. Yet while these actors embrace an ideal form of rational-instrumental evidence use under the banner of ‘evidence based policymaking’, they often struggle to understand when, why, or how evidence is used in policy processes. This chapter sets out the conceptual framework employed in this volume to study the use of evidence within policymaking from a public policy perspective. It explores the importance of both political contestation and institutional context to understand when and how evidence will be used within policy processes. The chapter then outlines the structure of this book and the focus of subsequent chapters, highlighting how each of these talks to these themes

The xylan-degrading enzyme system of Talaromyces emersonii : novel enzymes with activity against aryl β-D-xylosides and unsubstituted xylans

Talaromyces emersonii, a thermophilic aerobic fungus, produces a complete xylan-degrading enzyme system when grown on appropriate substrates. In this paper we present the physicochemical and catalytic properties of three enzymes, xylosidase (Xy1) I (M, 181 000; pI 8.9), II (M, 131 000; pl 5.3) and III (M(r) 54200; pI 4.2). Xyl I and II appear to be dimeric and Xyl III is a single-subunit protein. All three enzymes catalyse the hydrolysis of aryl beta-D-xylosides and xylo-oligosaccharides. Xyl I is a classic beta-xylosidase (1,4-beta-D-Xylan xylohydrolase; EC 3.2.1.37), and Xyl II and III are novel xylanases (endo- 1,4-beta-D-xylan xylanohydrolase; EC 3.2.1.8) which we believe have not hitherto been reported. In addition to the above substrates, they also catalyse the extensive hydrolysis of unsubstituted xylans, and may have considerable biotechnological potential. The hydrolysis product profiles and bond-cleavage frequencies with various substrates are presented

Kinetic parameters and mode of action of the cellobiohydrolases produced by Talaromyces emersonii.

A

Metabolic engineering for improved microbial pentose fermentation

Global concern over the depletion of fossil fuel reserves, and the detrimental impact that combustion of these materials has on the environment, is focusing attention on initiatives to create sustainable approaches for the production and use of biofuels from various biomass substrates. The development of a low-cost, safe and eco-friendly process for the utilization of renewable resources to generate value-added products with biotechnological potential as well as robust microorganisms capable of efficient fermentation of all types of sugars are essential to underpin the economic production of biofuels from biomass feedstocks. Saccharomyces cerevisiae, the most established fermentation yeast used in large scale bioconversion strategies, does not however metabolise the pentose sugars, xylose and arabinose and bioengineering is required for introduction of efficient pentose metabolic pathways and pentose sugar transport proteins for bioconversion of these substrates. Our approach provided a basis for future experiments that may ultimately lead to the development of industrial S. cerevisiae strains engineered to express pentose metabolising proteins from thermophilic fungi living on decaying plant material and here we expand our original article and discuss the strategies implemented to improve pentose fermentation

An integrated assessment of nitrogen source, transformation and fate within an intensive dairy system to inform management change

From an environmental perspective optimised dairy systems, which follow current regulations, still have low nitrogen (N) use efficiency, high N surplus (kg N ha¯¹) and enable ad-hoc delivery of direct and indirect reactive N losses to water and the atmosphere. The objective of the present study was to divide an intensive dairy farm into N attenuation capacity areas based on this ad-hoc delivery. Historical and current spatial and temporal multi-level data-sets (stable isotope and dissolved gas) were combined and interpreted. Results showed that the farm had four distinct attenuation areas: high N attenuation: characterised by ammonium-N (NH₄⁺-N) below 0.23 mg NH₄⁺-N l¯¹ and nitrate (NO₃¯-N) below 5.65 mg NO₃-N l¯¹ in surface, drainage and groundwater, located on imperfectly to moderately-well drained soils with high denitrification potential and low nitrous oxide (N₂O) emissions (av. 0.0032 mg N₂O-N l¯¹); moderate N attenuation: characterised by low NO₃¯-N concentration in drainage water but high N₂O production (0.0317 mg N₂O-N l¯¹) and denitrification potential lower than group 1 (av. δ¹⁵N-NO3-: 16.4, av. δ¹⁸O-NO₃-: 9.2), on well to moderately drained soils; low N attenuation—area 1: characterised by high NO₃-¯N (av. 6.90 mg NO₃¯-N l¯¹) in drainage water from well to moderately-well drained soils, with low denitrification potential (av. δ¹⁵N-NO₃-: 9.5, av. δ¹⁸O-NO₃-: 5.9) and high N₂O emissions (0.0319 mg N₂O l-1); and low N attenuation—area 2: characterised by high NH₄⁺-N (av. 3.93 mg NH4+-N l¯¹ and high N₂O emissions (av. 0.0521 mg N₂O l¯¹) from well to imperfectly drained soil. N loads on site should be moved away from low attenuation areas and emissions to air and water should be assessed

Influences and hegemonies in health reform research

Analizamos la evolución de las publicaciones, incluidas en MEDLINE, LILACS y Sociological Abstracts, sobre las Reformas de Salud en el mundo y las influencias que determinan su orientación y distribución en el período de 1990-2004. En total se seleccionaron 8.729 publicaciones. Los principios de “Sostenibilidad” y “Calidad y Efectividad” son los más atendidos, existiendo distintos patrones de atención, dependiendo de regiones y países. De 199 países, el 61% tiene referencia sobre sus procesos de reforma, siendo Estados Unidos y Gran Bretaña los que agrupan la mayor cantidad. Se observó que existen fuertes influencias para el estudio de las Reformas de Salud, provenientes de los patrones Británico y Norteamericano de atención a los Principios de Reforma. Esto puede estar limitando la visibilidad científica de cuestiones como la equidad, participación y eficiencia.The authors analyze the evolution in publications indexed in MEDLINE, LILACS, and Sociological Abstracts concerning health reforms around the world and the determinants of their orientation and distribution from 1990 to 2004. A total of 8,729 publications were selected. The principles of “sustainability” and “quality and effectiveness” were dealt with most frequently, with different patterns of attention, depending on the regions and countries. Of 199 countries, 61% included references as to their health reform processes, with the largest numbers in the United States and the Great Britain. The British and U.S. standards for attention to health reform principles displayed strong influences on the study of health reforms elsewhere. This may limit the scientific visibility of issues like equity, participation, and efficiency