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Di-hadron correlations with identified leading hadrons in 200 GeV Au+Au and d+Au collisions at STAR
(2015)
The STAR collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au+Au and minimum-bias d+Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au+Au data with respect to the d+Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the \emph{ridge region}, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.
We present the first measurements of charge-dependent correlations on angular difference variables η1 − η2 (pseudorapidity) and φ1 − φ2 (azimuth) for primary charged hadrons with transverse momentum 0.15 <= pt <= 2 GeV/c and |η| <= 1.3 from Au–Au collisions at √sNN = 130 GeV. We observe correlation structures not predicted by theory but consistent with evolution of hadron emission geometry with increasing centrality from one-dimensional fragmentation of color strings along the beam direction to an at least two-dimensional hadronization geometry along the beam and azimuth directions of a hadron-opaque bulk medium.
Background: Predicted increases in suicide were not generally observed in the early months of the COVID-19 pandemic. However, the picture may be changing and patterns might vary across demographic groups. We aimed to provide a timely, granular picture of the pandemic's impact on suicides globally.
Methods: We identified suicide data from official public-sector sources for countries/areas-within-countries, searching websites and academic literature and contacting data custodians and authors as necessary. We sent our first data request on 22nd June 2021 and stopped collecting data on 31st October 2021. We used interrupted time series (ITS) analyses to model the association between the pandemic's emergence and total suicides and suicides by sex-, age- and sex-by-age in each country/area-within-country. We compared the observed and expected numbers of suicides in the pandemic's first nine and first 10-15 months and used meta-regression to explore sources of variation.
Findings: We sourced data from 33 countries (24 high-income, six upper-middle-income, three lower-middle-income; 25 with whole-country data, 12 with data for area(s)-within-the-country, four with both). There was no evidence of greater-than-expected numbers of suicides in the majority of countries/areas-within-countries in any analysis; more commonly, there was evidence of lower-than-expected numbers. Certain sex, age and sex-by-age groups stood out as potentially concerning, but these were not consistent across countries/areas-within-countries. In the meta-regression, different patterns were not explained by countries’ COVID-19 mortality rate, stringency of public health response, economic support level, or presence of a national suicide prevention strategy. Nor were they explained by countries’ income level, although the meta-regression only included data from high-income and upper-middle-income countries, and there were suggestions from the ITS analyses that lower-middle-income countries fared less well.
Interpretation: Although there are some countries/areas-within-countries where overall suicide numbers and numbers for certain sex- and age-based groups are greater-than-expected, these countries/areas-within-countries are in the minority. Any upward movement in suicide numbers in any place or group is concerning, and we need to remain alert to and respond to changes as the pandemic and its mental health and economic consequences continue.
Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process.
Native vegetation of the NSW south coast, escarpment and southeast tablelands was classified into 191 floristic assemblages at a level of detail appropriate for the discrimination of Threatened Ecological Communities and other vegetation units referred to in government legislation. Assemblages were derived by a numerical analysis of 10832 field sample quadrats including 8523 compiled from 63 previous vegetation surveys. Past bias in the distribution of field data towards land under public tenure was corrected by extensive surveys carried out on private land. The classification revises and integrates the units described in recent vegetation studies of Eden, Cumberland Plain and Sydney-south coast into a single, consistent classification. Relationships between floristic assemblages and climate, terrain, substrate and vegetation structure were used to map the distribution of communities prior to clearing at 1:100 000 scale. The extent of clearing was mapped using interpretations of remote imagery (1991–2001) from previous work, standardised and merged into a single coverage and supplemented with additional work. Profiles for each assemblage, which we term ‘communities’ or ‘map units’, describe their species composition, vegetation structure, environmental habitat, the extent of clearing and conservation status. Lists of diagnostic species were defined using a statistical fidelity measure and a procedure for using these for community identification is described. Approximately 66% of the study area retains a cover of native vegetation, primarily in areas with low fertility soils and dissected topography. Communities subject to over-clearing (>70%) are concentrated in a few large areas characterised by clay/loam soils and flat to undulating terrain. These include the Sydney metropolis, Wingecarribee Plateau, Illawarra Plain, Shoalhaven floodplain, Araluen Valley and Bega Valley, and various smaller river valleys. Forty-one percent of remaining native vegetation is protected within conservation reserves while 31% occurs on private land, 20% in State Forests and 8% on other Crown lands. Forty-five Threatened Ecological Communities (TECs) were recorded in the study area. The majority of TECs are represented by a single map unit, although in some cases a TEC is included within a broader map unit. Twelve TECs are represented by combinations of two or more map units.
Terrestrial, freshwater and estuarine native vegetation of the Eden region was classified into 79 floristic assemblages and mapped at 1:100,000 scale. Assemblages were derived from multivariate analysis of 1604 quantitative vegetation samples. Mapping was carried out using a hybrid decision tree-expert system approach based on quantitative relationships between floristic assemblages and spatial variables (land cover pattern, substrate, climatic variables and terrain variables) and qualitative expert knowledge derived from field experience. The use of vegetation environment relationships and sampling of remnants allowed prediction of vegetation patterns prior to European clearing. The map was validated using three procedures: qualitative checking by experts; reliability mapping using sampling intensity; and accuracy quantification using independent sample data. The map units were described using comprehensive profiles of diagnostic species, structural features, habitat characteristics and sample distributions.
The 79 floristic assemblages include rainforests, mesic eucalypt forests, dry grassy eucalypt forests of the coastal rain shadow valleys, hinterland and tableland, dry shrubby eucalypt forests, grasslands, heathlands, scrubs and wetlands. Variation in climate and geological substrate influence vegetation patterns at regional scales, while variation in topography, local soil moisture and nutrient status and disturbance regimes influence vegetation patterns at local scales. Sixty-eight per cent of the region retained a cover of native vegetation in 1994. Processes threatening various portions of the remainder include further habitat loss from clearing, high-frequency disturbances and certain other disturbance regimes, overgrazing, habitat degradation due to nutrification, dumping and vandalism, and feral animal activity. Past depletion of habitat has been highly biased. Some grassy assemblages on fertile flat terrain are depleted by more than 90%, while some forests with shrubby understories in steep infertile terrain retain close to their original extent. The former assemblages are distributed principally as remnants on privately owned land, while the latter occur in remote areas of public land. Representation in conservation reserves is also biased against grassy assemblages in fertile flat terrain, as well as some other assemblages with restricted distributions. Opportunities for conservation of these assemblages are now very limited and rely on integrated planning, reservation and cooperative management with emphasis on private land.
An exhaustive review of available information revealed 1522 native vascular plant taxa with confirmed records in the Eden region. A further 136 taxa potentially occur in the region, but these remain to be confirmed. Families represented by large numbers of taxa in the indigenous flora include the Fabaceae, Poaceae, Asteraceae, Myrtaceae and Orchidaceae. Species frequencies were highly skewed with 74% of the flora represented in less than 1% of survey samples and only three taxa represented in more than 40% of samples. A large number of records (350 taxa) were evaluated and refuted, emphasizing the importance of critical validation when compiling biological inventory data from multiple sources. Errors are most likely to arise from nomenclatural synonymy and other duplications, misidentifications and erroneous locality information.
The confirmed vascular flora of the Eden region is relatively species-rich compared with other regions in tropical, temperate and semi-arid Australia, although these regions are less well-known botanically. However, the proportion of endemism (1%) is comparatively low, with 18 taxa unique to the region and a further 14 taxa with distributions extending just beyond the region. The Eden region includes 32 taxa listed as endangered or vulnerable in Australia and a further six taxa listed as endangered in New South Wales but not throughout Australia. Thirty-eight taxa were listed as rare in Australia and a further 39 were considered to be uncommon throughout their distribution. Four hundred and sixty-six taxa were considered to be uncommon within the Eden region. Two hundred and seventy-six taxa reached their distributional limits in the Eden region, about three quarters of these reaching their southern limits. Fifty taxa were represented in the region by disjunct populations.
Introduced taxa accounted for approximately 20% of the total regional vascular flora, although this proportion is likely to underestimate the introduced flora given the limitations of available data. The introduced flora is dominated by Poaceae, Asteraceae, Fabaceae and Caryophyllaceae. Very few introduced taxa were widespread in native vegetation. The most common introduced taxa were herbs with long-distance propagule dispersal mechanisms.