Star Formation triggered by cloud-cloud collisions

We present the results of SPH simulations in which two clouds, each having mass $M_{_{\rm{o}}}\!=\!500\,{\rm M}_{_\odot}$ and radius $R_{_{\rm{o}}}\!=\!2\,{\rm pc}$, collide head-on at relative velocities of $\Delta v_{_{\rm{o}}} =2.4,\;2.8,\;3.2,\;3.6\;{\rm and}\;4.0\,{\rm km}\,{\rm s}^{-1}$. There is a clear trend with increasing $\Delta v_{_{\rm{o}}}$. At low $\Delta v_{_{\rm{o}}}$, star formation starts later, and the shock-compressed layer breaks up into an array of predominantly radial filaments; stars condense out of these filaments and fall, together with residual gas, towards the centre of the layer, to form a single large-$N$ cluster, which then evolves by competitive accretion, producing one or two very massive protostars and a diaspora of ejected (mainly low-mass) protostars; the pattern of filaments is reminiscent of the hub and spokes systems identified recently by observers. At high $\Delta v_{_{\rm{o}}}$, star formation occurs sooner and the shock-compressed layer breaks up into a network of filaments; the pattern of filaments here is more like a spider's web, with several small-$N$ clusters forming independently of one another, in cores at the intersections of filaments, and since each core only spawns a small number of protostars, there are fewer ejections of protostars. As the relative velocity is increased, the {\it mean} protostellar mass increases, but the {\it maximum} protostellar mass and the width of the mass function both decrease. We use a Minimal Spanning Tree to analyse the spatial distributions of protostars formed at different relative velocities.Comment: 10 pages, 11 figure

The Molecular Line Opacity of MgH in Cool Stellar Atmospheres

A new, complete, theoretical rotational and vibrational line list for the A-X electronic transition in MgH is presented. The list includes transition energies and oscillator strengths for all possible allowed transitions and was computed using the best available theoretical potential energies and dipole transition moment function with the former adjusted to account for experimental data. The A-X line list, as well as new line lists for the B'-X and the X-X (pure rovibrational) transitions, were included in comprehensive stellar atmosphere models for M, L, and T dwarfs and solar-type stars. The resulting spectra, when compared to models lacking MgH, show that MgH provides significant opacity in the visible between 4400 and 5600 Angstrom. Further, comparison of the spectra obtained with the current line list to spectra obtained using the line list constructed by Kurucz (1993) show that the Kurucz list significantly overestimates the opacity due to MgH particularly for the bands near 5150 and 4800 Angstrom with the discrepancy increasing with decreasing effective temperature.Comment: 10 pages, 4 figures, 3 table

Advocating co-productive engagement with marginalised people: a specific perspective on and by survivors of childhood sexual abuse

Co-production is gaining ground as a key dimension of public policy reform across the globe.This paper argues in favour of social welfare shaped by the principles of co-production and suggests that the promotion of democratic relationships is more likely to enable the agency and recovery of victim-survivors of childhood sexual abuse. The paper, based on an autoethnographical approach, is likely to be of relevance to social care practitioners who work with a range of marginalised people, particularly in liberal states that promote organisational cultures shaped disproportionately by risk. Cultures of risk, it is argued, promote power balances and ‘othering’, arguably an institutional perpetuation of the original abuse. Co-production, on the other hand, has the potential to legitimise expertise by experience, enabling victim-survivors to be reinstated as citizens with associated rights of participation. The paper subsequently draws out some of the benefits of co-production for practitioners whose professional engagement may be stifled. We suggest that co-production potentially points towards practice based on the valuing of expertise by experience and social solidarity

Appetite for self-destruction: suicidal biting as a nest defense strategy in Trigona stingless bees

Self-sacrificial behavior represents an extreme and relatively uncommon form of altruism in worker insects. It can occur, however, when inclusive fitness benefits are high, such as when defending the nest. We studied nest defense behaviors in stingless bees, which live in eusocial colonies subject to predation. We introduced a target flag to nest entrances to elicit defensive responses and quantified four measures of defensivity in 12 stingless bee species in São Paulo State, Brazil. These included three Trigona species, which are locally known for their aggression. Species varied significantly in their attack probability (cross species range = 0–1, P < 0.001), attack latency (7.0–23.5 s, P = 0.002), biting duration of individual bees (3.5–508.7 s, P < 0.001), and number of attackers (1.0–10.8, P < 0.001). A “suicide” bioassay on the six most aggressive species determined the proportion of workers willing to suffer fatal damage rather than disengage from an intruder. All six species had at least some suicidal individuals (7–83 %, P < 0.001), reaching 83 % in Trigona hyalinata. Biting pain was positively correlated with an index of overall aggression (P = 0.002). Microscopic examination revealed that all three Trigona species had five sharp teeth per mandible, a possible defensive adaptation and cause of increased pain. Suicidal defense via biting is a new example of self-sacrificial altruism and has both parallels and differences with other self-sacrificial worker insects, such as the honey bee. Our results indicate that suicidal biting may be a widespread defense strategy in stingless bees, but it is not universal

Importance of private and communal lands to sustainable conservation of Africa's rhinoceroses

A new path for rhinoceros (rhino) conservation is needed. Recent data signal the alarming impact of poaching on populations in Africa's rhino stronghold, the state-run Kruger National Park (South Africa), which today supports one quarter the rhinos than a decade ago. We aggregated African rhino population data, highlighting the growing role of private and community rhino custodians, who likely now conserve >50% of Africa's rhinos. Their contribution has been enabled by a supportive policy and economic environment, but this arrangement is becoming more difficult to sustain as costs associated with protecting rhinos skyrocket and revenue-generating options become insufficient. Some privately held rhino populations are small or intensively managed, raising questions about their conservation value. As the role of private and community custodianship becomes increasingly central to the protection of Africa's remaining rhinos, its resilience must be strengthened through implementation of adaptive policies that incentivize rhino conservation. We outline policy pathways to provide an enabling environment for rhino conservation beyond state parks.Peer reviewe

Consumer response to computerised nutritional information at the point-of-purchase in catering establishments.

Increased scientific understanding of the links between nutrition and health has led to a demand for more nutrition information to be made available to consumers. Nutrition information is widely available on supermarket products but is rarely found in catering establishments. This research involved the provision of nutrition information in canteens and restaurants and studied the effect on consumer meal choices. A study was designed to find the optimum visual method of displaying nutrition information. Eight nutritional formats were systematically tested on customers in a shopping centre food court. Graphical formats displaying nutrition information in relation to current dietary advice relayed the nutrition information significantly quicker than, and as accurately as, tabular displays. A database system was developed to provide nutrition information on menu items making up a selected meal. A program suite was designed to enable the creation of recipes and menus. The nutritional breakdown of a selected meal was displayed to the customer who was then given the opportunity to change their meal before that meal was acquired. All initial choices and subsequent changes were recorded for analysis. Surveys carried out in two canteen locations (n=694) revealed that a significant percentage of customers (16%) did make changes to their meal after viewing the nutritional information on their first choice. Those who did not change were, on average, making "healthy" choices of meal. Those who did change made second choices which were, on average, significantly lower in energy, saturated fatty acids and non-milk extrinsic sugars than their first selections. Overall "healthier" choices were made with the second selection which did not differ significantly from the nutritional content of the meals chosen by those respondents who had not wished to change. Further research is necessary to determine whether the intention to change a selected meal as demonstrated by this research would be carried through by the respondents to the actual food selection

The Cape Triage Score - a triage system for South Africa

The Cape Triage Score (CTS) has been derived by the Cape Triage Group (CTG) for use in emergency units throughout South Africa. It can also be used in the pre-hospital setting, although it is not designed for mass casualty situations. The CTS comprises a physiologically based scoring system and a list of discriminators, designed to triage patients into one of five priority groups for medical attention. Three versions have been developed, for adults, children and infants. As part of the ongoing assessment process the CTG would value feedback from the readers of this Journal

Modelling the evolution of distributions : an application to major league baseball

We develop Bayesian techniques for modelling the evolution of entire distributions over time and apply them to the distribution of team performance in Major League baseball for the period 1901-2000. Such models offer insight into many key issues (e.g. competitive balance) in a way that regression-based models cannot. The models involve discretizing the distribution and then modelling the evolution of the bins over time through transition probability matrices. We allow for these matrices to vary over time and across teams. We find that, with one exception, the transition probability matrices (and, hence, competitive balance) have been remarkably constant across time and over teams. The one exception is the Yankees, who have outperformed all other teams

Influence of Crohn’s disease related polymorphisms in innate immune function on ileal microbiome

We have previously identified NOD2 genotype and inflammatory bowel diseases (IBD) phenotype, as associated with shifts in the ileal microbiome (“dysbiosis”) in a patient cohort. Here we report an integrative analysis of an expanded number of Crohn's disease (CD) related genetic defects in innate immune function (NOD2, ATG16L1, IRGM, CARD9, XBP1, ORMDL3) and composition of the ileal microbiome by combining the initial patient cohort (Batch 1, 2005–2010, n = 165) with a second consecutive patient cohort (Batch 2, 2010–2012, n = 118). These combined patient cohorts were composed of three non-overlapping phenotypes: 1.) 106 ileal CD subjects undergoing initial ileocolic resection for diseased ileum, 2.) 88 IBD colitis subjects without ileal disease (predominantly ulcerative colitis but also Crohn’s colitis and indeterminate colitis, and 3.) 89 non-IBD subjects. Significant differences (FDR C. difficile infection, and NOD2 genotype on ileal dysbiosis in the expanded analysis. The relative abundance of the Proteobacteria phylum was positively associated with ileal CD and colitis phenotypes, but negatively associated with NOD2R genotype. Additional associations with ORMDL3 and XBP1 were detected at the phylum/subphylum level. IBD medications, such as immunomodulators and anti-TNFα agents, may have a beneficial effect on reversing dysbiosis associated with the IBD phenotype. Exploratory analysis comparing microbial composition of the disease unaffected region of the resected ileum between 27 ileal CD patients who subsequently developed endoscopic recurrence within 6–12 months versus 34 patients who did not, suggested that microbial biomarkers in the resected specimen helped stratify patients with respect to risk of post-surgical recurrence.</div