The Structure of Molecular Clouds: III - A link between cloud structure and star formation mode

We analyse extinction maps of nearby Giant Molecular Clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self shielding threshold of 1mag Av and below the star formation threshold -- the regime in which turbulence is expected to dominate. We identify clouds with shallow mass distributions as cluster forming. Clouds that form stars in a less clustered or isolated mode show a steeper mass distribution. Structure functions prove inadequate to distinguish between clouds of different star formation mode. They may, however, suggest that the turbulence in the average cloud is governed by solenoidal forcing. The same is found using the Delta-variance analysis which also indicates that clouds with a clustered mode of star formation show an enhanced component of compressive driving in the turbulent field. Thus, while star formation occurs in each cloud, independent of the turbulent driving mechanism, compressive forcing appears to be associated with the formation of stellar clusters.Comment: 10 pages, 3 figures, 2 tables, accepted for publication by MNRAS, a version with higher resolution figures can be found at http://astro.kent.ac.uk/~df

The Structure of Molecular Clouds: II - Column Density and Mass Distributions

The formation of stars is inextricably linked to the structure of their parental molecular clouds. Here we take a number of nearby giant molecular clouds (GMCs) and analyse their column density and mass distributions. This investigation is based on four new all-sky median colour excess extinction maps determined from 2MASS. The four maps span a range of spatial resolution of a factor of eight. This allows us to determine cloud properties at a common spatial scale of 0.1pc, as well as to study the scale dependence of the cloud properties. We find that the low column density and turbulence dominated part of the clouds can be well fit by a log-normal distribution. However, above a universal extinction threshold of 6.0 \pm 1.5mag A_V there is excess material compared to the log-normal distribution in all investigated clouds. This material represents the part of the cloud that is currently involved in star formation, and thus dominated by gravity. Its contribution to the total mass of the clouds ranges over two orders of magnitude from 0.1 to 10%. This implies that our clouds sample various stages in the evolution of GMCs. Furthermore, we find that the column density and mass distributions are extremely similar between clouds if we analyse only the high extinction material. On the other hand, there are significant differences between the distributions if only the low extinction, turbulence dominated regions are considered. This shows that the turbulent properties differ between clouds depending on their environment. However, no significant influence on the predominant mode of star formation (clustered or isolated) could be found. Furthermore, the fraction of the cloud actively involved in star formation is only governed by gravity, with the column density and mass distributions not significantly altered by local feedback processes.Comment: 31 pages, 4 tables, 99 figures, accepted for publication by MNRAS, a version with higher resolution figures can be found at http://astro.kent.ac.uk/extinction

The content of Recovery College courses in England: a 71 college document analysis

Introduction: Recovery Colleges (RCs) exist in 28 countries and across five continents. The concept of recovery and recovery-oriented care has become widespread internationally and embedded in policy documentation and mental health services. As a result, Recovery Colleges, which focus on adult learning and co-production, have now developed a global presence, but many psychiatrists are unfamiliar with this intervention. RCs can be categorized as ‘Strengths Oriented’, focusing on skills and knowledge development, or ‘Community-oriented’, emphasizing strengthening community and social connections. Research has not sufficiently investigated RC curriculum and how course provision differs depending on RC orientation. The study aimed to develop a typology of RC courses and assess differences in course types across RC orientations.Method: A document analysis was conducted. The websites of 88 RCs in England were searched to collect online prospectuses. Overall, 2,330 courses described in 551 documents from 71 RCs were collated. Inductive content analysis was applied to the course titles to develop a typology of courses offered. Mann-Whitney U tests were used to assess differences in the median number of course types offered by Strengths-Oriented versus Community-Oriented colleges.Results: A typology of 14 superordinate course categories was created. The three most common course categories were Self-management of Well-being (96% RCs ≥1 course, median 10 courses per RC), Mental Health Conditions and Symptoms (85% RCs ≥1 course, 4 courses per RC), and Creativity (86% RCs ≥1 course, 3 courses per RC). The least common course categories included Issues relating to the Extended Support Network and Issues relating to Staff (38% RCs ≥1 course, 0 courses per RC) (6% RCs ≥1 course, 0 courses per RC). The median number of courses did not differ between Strengths-oriented versus Community-oriented RCs, with the exception of more Practical Life Skills (p=0.021) and Involvement, Co-production and Research (p=0.036) courses in Strengths-oriented RCs.Conclusions: RCs support mental health recovery through a diverse curriculum. Community-facing and strengths-based, health service-affiliated RCs offer similar courses. RCs prioritize equipping students with knowledge about living with mental health issues. Courses targeted to informal carers are lacking. Further cross-cultural extension of the typology is needed

Genomic infrastructure for cetacean research and conservation: reference genomes for eight families spanning the cetacean tree of life

Reference genomes from representative species across families provide the critical infrastructure for research and conservation. The Cetacean Genomes Project (CGP) began in early 2020 to facilitate the generation of near error-free, chromosome-resolved reference genomes for all cetacean species. Towards that goal, and using the methods, goals and genome assembly quality standards of the Vertebrate Genomes Project (VGP), we generated 13 new reference genomes across eight of the 14 cetacean families. Additionally, we summarize the genome assembly characteristics for 18 species, including these newly-generated and five published genome assemblies that meet the completeness and quality standards. We infer ancestral linkage groups (ALG) for cetaceans, showing that the ancestral karyotype of 22 ALGs is largely conserved in extant species, except for Ziphiidae, and for Balaenidae and Kogiidae, which exhibit similar independent fusions. Gene annotation, characterization of historical demography, heterozygosity and runs of homozygosity (ROH) reveal important information for conservation applications. By comparing the new reference genomes to previous draft assemblies, we show that the reference genomes have enhanced characteristics that will support and promote scientific research. Specifically, the genomes improve resolution and characterization of repetitive elements, provide validation (or exclusion) of genes linked to complex traits, and allow more complete characterization of gene regions such as the highly complex Major Histocompatibility Complex (MHC) Class I and II gene clusters that are important for population health

The structure of molecular clouds

The physics and turbulent properties responsible for shaping the structure in molecular clouds are analysed. Data from the Two-Micron All-Sky Survey are used to determine all-sky median near-infrared extinction maps. Two types of map are made: maps with a near-constant noise in each pixel and maps with a constant resolution. The standard map has a resolution as high as l' along the Galactic plane. The resolution and depth of optical extinction are significantly better than those achieved in previous large-scale studies. The maps are used to examine the column density and mass distributions of 30 nearby molecular clouds. The low column density (i.e. turbulence dominated) parts of the clouds could be well fit by a log-normal distribution. A universal extinction threshold of AV = 5.6 ± 1.2 mag is found, above which there is an excess of material when compared to a log-normal distribution. Gravity is implied as the dominant factor in structure shap­ing above this threshold, as the column density and mass distributions are similar for all clouds. Below this threshold, the structure is determined by turbulence and the environ­ment of the cloud. Two groups of clouds with distinct column density/mass distributions are identified, that correspond to ‘star forming’ and ‘non-star forming’ groups. Structure function and Δ-variance analyses are performed on the same nearby molec­ular clouds. Average values are calculated for the structure function parameters A, intermittency, codimension and fractal dimension. The results imply a mixture of solenoidal and compressive forcing in the turbulence dominated regions of the clouds. An average value for the mass index scaling exponent is calculated which is close to the value expected for clouds where turbulence is driven/governed by solenoidal forc­ing. For the ‘star forming’ clouds the average value implies a mixture of solenoidal and compressive forcing, while the value for the ‘non-star forming’ group implies exclusively solenoidal forcing. It is concluded from this that compressive forcing is associated with the presence of clustered star formation

Removal of N-Linked Glycosylation Sites in the V1 Region of Simian Immunodeficiency Virus gp120 Results in Redirection of B-Cell Responses to V3

One mechanism of immune evasion utilized by human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) envelope glycoproteins is the presence of a dense carbohydrate shield. Accumulating evidence from in vitro and in vivo experiments suggests that alterations in N-linked glycosylation of SIV gp120 can enhance host humoral immune responses that may be involved in immune control. The present study was designed to determine the ability of glycosylation mutant viruses to redirect antibody responses to shielded envelope epitopes. The influence of glycosylation on the maturation and specificity of antibody responses elicited by glycosylation mutant viruses containing mutations of specific N-linked sites in and near the V1 and V2 regions of SIVmac239 gp120 was determined. Results from these studies demonstrated a remarkably similar maturation of antibody responses to native, fully glycosylated envelope proteins. However, analyses of antibodies to defined envelope domains revealed that mutation of glycosylation sites in V1 resulted in increased antibody recognition to epitopes in V1. In addition, we demonstrated for the first time that mutation of glycosylation sites in V1 resulted in a redirection of antibody responses to the V3 loop. Taken together, these results demonstrate that N-linked glycosylation is a determinant of SIV envelope B-cell immunogenicity in addition to in vitro antigenicity. In addition, our results demonstrate that the absence of N-linked carbohydrates at specific sites can influence the exposure of epitopes quite distant in the linear sequence