The provenance, date and significance of a Cook-voyage Polynesian sculpture

A unique wooden sculpture collected by James Cook during his first voyage to the Pacific is widely considered to be a masterpiece of Oceanic art, but its exact provenance has been unclear. New analysis of shavings from the object now indicate that a) the tree from which it was carved was felled between 1690 and 1728, and that the carving was therefore up to 80 years old when obtained, and b) it originated in Tahiti, despite its stylistic affinities with art from the Austral Islands. Motifs and forms clearly travelled within regions, and populations interacted in ways that blur presumed tribal boundaries. It is perhaps time to reconsider the association between region and style upon which the cataloguing and identification of objects routinely depends.The research reported upon here has taken place in the context of two projects, 'Artefacts of Encounter', funded by the UK Arts and Humanities Research Council over 2010-13, and 'Pacific Presences', funded by the European Research Council over 2013-18. We are grateful to both agencies for their support. We also thank: Julie Adams (British Museum); Peter Brunt (Victoria University); Caroline Cartwright (British Museum); Steven Hooper (University of East Anglia); JeanYves Meyer (Ministère des Ressources Marines, des Mines et de la Recherche, Polynésie Française); Mark Nesbitt (Economic Botany Collection, Royal Botanic Gardens, Kew); Tamsin O’Connell (Dorothy Garrod Laboratory for Isotopic Analysis, McDonald Institute for Archaeological Research); Jessica Royles (Department of Plant Sciences, University of Cambridge); Matthew Spriggs (Australian National University); and the University of Oxford Radiocarbon Accelerator Unit

Population Monte Carlo algorithms

We give a cross-disciplinary survey on ``population'' Monte Carlo algorithms. In these algorithms, a set of ``walkers'' or ``particles'' is used as a representation of a high-dimensional vector. The computation is carried out by a random walk and split/deletion of these objects. The algorithms are developed in various fields in physics and statistical sciences and called by lots of different terms -- ``quantum Monte Carlo'', ``transfer-matrix Monte Carlo'', ``Monte Carlo filter (particle filter)'',``sequential Monte Carlo'' and ``PERM'' etc. Here we discuss them in a coherent framework. We also touch on related algorithms -- genetic algorithms and annealed importance sampling.Comment: Title is changed (Population-based Monte Carlo -> Population Monte Carlo). A number of small but important corrections and additions. References are also added. Original Version is read at 2000 Workshop on Information-Based Induction Sciences (July 17-18, 2000, Syuzenji, Shizuoka, Japan). No figure

The association between green space and cause-specific mortality in urban New Zealand: an ecological analysis of green space utility

<b>Background:</b> There is mounting international evidence that exposure to green environments is associated with health benefits, including lower mortality rates. Consequently, it has been suggested that the uneven distribution of such environments may contribute to health inequalities. Possible causative mechanisms behind the green space and health relationship include the provision of physical activity opportunities, facilitation of social contact and the restorative effects of nature. In the New Zealand context we investigated whether there was a socioeconomic gradient in green space exposure and whether green space exposure was associated with cause-specific mortality (cardiovascular disease and lung cancer). We subsequently asked what is the mechanism(s) by which green space availability may influence mortality outcomes, by contrasting health associations for different types of green space. <b>Methods:</b> This was an observational study on a population of 1,546,405 living in 1009 small urban areas in New Zealand. A neighbourhood-level classification was developed to distinguish between usable (i.e., visitable) and non-usable green space (i.e., visible but not visitable) in the urban areas. Negative binomial regression models were fitted to examine the association between quartiles of area-level green space availability and risk of mortality from cardiovascular disease (n = 9,484; 1996 - 2005) and from lung cancer (n = 2,603; 1996 - 2005), after control for age, sex, socio-economic deprivation, smoking, air pollution and population density. <b>Results:</b> Deprived neighbourhoods were relatively disadvantaged in total green space availability (11% less total green space for a one standard deviation increase in NZDep2001 deprivation score, p < 0.001), but had marginally more usable green space (2% more for a one standard deviation increase in deprivation score, p = 0.002). No significant associations between usable or total green space and mortality were observed after adjustment for confounders. <b>Conclusion</b> Contrary to expectations we found no evidence that green space influenced cardiovascular disease mortality in New Zealand, suggesting that green space and health relationships may vary according to national, societal or environmental context. Hence we were unable to infer the mechanism in the relationship. Our inability to adjust for individual-level factors with a significant influence on cardiovascular disease and lung cancer mortality risk (e.g., diet and alcohol consumption) will have limited the ability of the analyses to detect green space effects, if present. Additionally, green space variation may have lesser relevance for health in New Zealand because green space is generally more abundant and there is less social and spatial variation in its availability than found in other contexts

Monitoring health inequalities: life expectancy and small area deprivation in New Zealand

BACKGROUND: Socioeconomic and ethnic inequalities in health are of great concern, and life expectancy provides a readily understood means of monitoring such inequalities. The objectives of this study are to (1) measure life expectancy by socioeconomic deprivation and ethnicity, and (2) describe trends in the deprivation gradient in life expectancy since the mid-1990s. METHODS: Three years of national mortality data have been combined with mid-point population denominators to produce life tables within nationally determined levels of small area deprivation (NZDep96) for three ethnic group: European, Mäori and Pacific peoples. This process has been repeated for the periods 1995–97, 1996–98, 1997–99 and 1998–2000. RESULTS: There was a strong relationship between increasing small area deprivation and decreasing life expectancy. Through the mid- to late 1990s, males living in the most deprived small areas in New Zealand experienced life expectancies at birth approximately nine years less than their counterparts living in the least deprived areas; for females the corresponding difference was under seven years. Mäori and Pacific life expectancies at birth were lower than those of Europeans at each level of deprivation. Over the study period (1995–2000) the gradient in life expectancy across deprivation deciles remained stable. CONCLUSION: Small area deprivation analyses of life expectancy could be repeated routinely at regular intervals, which would provide a useful approach to monitoring trends in socioeconomic, geographic, ethnic and gender inequalities in mortality

Combinatorial quorum sensing allows bacteria to resolve their social and physical environment

Quorum sensing (QS) is a cell–cell communication system that controls gene expression in many bacterial species, mediated by diffusible signal molecules. Although the intracellular regulatory mechanisms of QS are often well-understood, the functional roles of QS remain controversial. In particular, the use of multiple signals by many bacterial species poses a serious challenge to current functional theories. Here, we address this challenge by showing that bacteria can use multiple QS signals to infer both their social (density) and physical (mass-transfer) environment. Analytical and evolutionary simulation models show that the detection of, and response to, complex social/physical contrasts requires multiple signals with distinct half-lives and combinatorial (nonadditive) responses to signal concentrations. We test these predictions using the opportunistic pathogen Pseudomonas aeruginosa and demonstrate significant differences in signal decay betweeallyn its two primary signal molecules, as well as diverse combinatorial responses to dual-signal inputs. QS is associated with the control of secreted factors, and we show that secretome genes are preferentially controlled by synergistic “AND-gate” responses to multiple signal inputs, ensuring the effective expression of secreted factors in high-density and low mass-transfer environments. Our results support a new functional hypothesis for the use of multiple signals and, more generally, show that bacteria are capable of combinatorial communication

Hematopoietic stem cell gene therapy targeting TGFβ enhances the efficacy of irradiation therapy in a preclinical glioblastoma model

Patients with glioblastoma (GBM) have a poor prognosis, and inefficient delivery of drugs to tumors represents a major therapeutic hurdle. Hematopoietic stem cell (HSC)-derived myeloid cells efficiently home to GBM and constitute up to 50% of intratumoral cells, making them highly appropriate therapeutic delivery vehicles. Because myeloid cells are ubiquitously present in the body, we recently established a lentiviral vector containing matrix metalloproteinase 14 (MMP14) promoter, which is active specifically in tumor-infiltrating myeloid cells as opposed to myeloid cells in other tissues, and resulted in a specific delivery of transgenes to brain metastases in HSC gene therapy. Here, we used this novel approach to target transforming growth factor beta (TGFβ) as a key tumor-promoting factor in GBM. Transplantation of HSCs transduced with lentiviral vector expressing green fluorescent protein (GFP) into lethally irradiated recipient mice was followed by intracranial implantation of GBM cells. Tumor-infiltrating HSC progeny was characterized by flow cytometry. In therapy studies, mice were transplanted with HSCs transduced with lentiviral vector expressing soluble TGFβ receptor II–Fc fusion protein under MMP14 promoter. This TGFβ-blocking therapy was compared with the targeted tumor irradiation, the combination of the two therapies, and control. Tumor growth and survival were quantified (statistical significance determined by t-test and log-rank test). T cell memory response was probed through a repeated tumor challenge. Myeloid cells were the most abundant HSC-derived population infiltrating GBM. TGFβ-blocking HSC gene therapy in combination with irradiation significantly reduced tumor burden as compared with monotherapies and the control, and significantly prolonged survival as compared with the control and TGFβ-blocking monotherapy. Long-term protection from GBM was achieved only with the combination treatment (25% of the mice) and was accompanied by a significant increase in CD8+ T cells at the tumor implantation site following tumor rechallenge. We demonstrated a preclinical proof-of-principle for tumor myeloid cell-specific HSC gene therapy in GBM. In the clinic, HSC gene therapy is being successfully used in non-cancerous brain disorders and the feasibility of HSC gene therapy in patients with glioma has been demonstrated in the context of bone marrow protection. This indicates an opportunity for clinical translation of our therapeutic approach