4,062 research outputs found
Coral reef ecosystem services in the Anthropocene
Coral reefs underpin a range of ecosystem goods and services that contribute to the well‐being of millions of people. However, tropical coral reefs in the Anthropocene are likely to be functionally different from reefs in the past. In this perspective piece, we ask, what does the Anthropocene mean for the provision of ecosystem services from coral reefs? First, we provide examples of the provisioning, regulating, cultural and supporting services underpinned by coral reef ecosystems. We conclude that coral reef ecosystem service research has lagged behind multidisciplinary advances in broader ecosystem services science, such as an explicit recognition that interactions between social and ecological systems underpin ecosystem services. Second, drawing on tools from functional ecology, we outline how these social–ecological relationships can be incorporated into a mechanistic understanding of service provision and how this might be used to anticipate future changes in coral reef ecosystem services. Finally, we explore the emergence of novel reef ecosystem services, for example from tropicalized coastlines, or through changing technological connections to coral reefs. Indeed, when services are conceived as coming from social–ecological system dynamics, novelty in services can emerge from elements of the interactions between people and the ecosystem. This synthesis of the coral reef ecosystem services literature suggests the field is poorly prepared to understand the changing service provision anticipated in the Anthropocene. A new research agenda is needed that better connects reef functional ecology to ecosystem service provision. This research agenda should embrace more holistic approaches to ecosystem service research, recognizing them as co‐produced by ecosystems and society. Importantly, the likelihood of novel ecosystem service configurations requires further conceptualization and empirical assessment. As with current ecosystem services, the loss or gain of services will not affect all people equally and must be understood in the context in which they occur. With the uncertainty surrounding the future of coral reefs in the Anthropocene, research exploring how the benefits to people change will be of great importance
Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study
Background: Human genetic factors are important determinants of malaria risk. We investigated associations between multiple candidate polymorphisms—many related to the structure or function of red blood cells—and risk for severe Plasmodium falciparum malaria and its specific phenotypes, including cerebral malaria, severe malaria anaemia, and respiratory distress. Methods: We did a case-control study in Kilifi County, Kenya. We recruited as cases children presenting with severe malaria to the high-dependency ward of Kilifi County Hospital. We included as controls infants born in the local community between Aug 1, 2006, and Sept 30, 2010, who were part of a genetics study. We tested for associations between a range of candidate malaria-protective genes and risk for severe malaria and its specific phenotypes. We used a permutation approach to account for multiple comparisons between polymorphisms and severe malaria. We judged p values less than 0·005 significant for the primary analysis of the association between candidate genes and severe malaria. Findings: Between June 11, 1995, and June 12, 2008, 2244 children with severe malaria were recruited to the study, and 3949 infants were included as controls. Overall, 263 (12%) of 2244 children with severe malaria died in hospital, including 196 (16%) of 1233 with cerebral malaria. We investigated 121 polymorphisms in 70 candidate severe malaria-associated genes. We found significant associations between risk for severe malaria overall and polymorphisms in 15 genes or locations, of which most were related to red blood cells: ABO, ATP2B4, ARL14, CD40LG, FREM3, INPP4B, G6PD, HBA (both HBA1 and HBA2), HBB, IL10, LPHN2 (also known as ADGRL2), LOC727982, RPS6KL1, CAND1, and GNAS. Combined, these genetic associations accounted for 5·2% of the variance in risk for developing severe malaria among individuals in the general population. We confirmed established associations between severe malaria and sickle-cell trait (odds ratio [OR] 0·15, 95% CI 0·11–0·20; p=2·61 × 10−58), blood group O (0·74, 0·66–0·82; p=6·26 × 10−8), and –α3·7-thalassaemia (0·83, 0·76–0·90; p=2·06 × 10−6). We also found strong associations between overall risk of severe malaria and polymorphisms in both ATP2B4 (OR 0·76, 95% CI 0·63–0·92; p=0·001) and FREM3 (0·64, 0·53–0·79; p=3·18 × 10−14). The association with FREM3 could be accounted for by linkage disequilibrium with a complex structural mutation within the glycophorin gene region (comprising GYPA, GYPB, and GYPE) that encodes for the rare Dantu blood group antigen. Heterozygosity for Dantu was associated with risk for severe malaria (OR 0·57, 95% CI 0·49–0·68; p=3·22 × 10−11), as was homozygosity (0·26, 0·11–0·62; p=0·002). Interpretation: Both ATP2B4 and the Dantu blood group antigen are associated with the structure and function of red blood cells. ATP2B4 codes for plasma membrane calcium-transporting ATPase 4 (the major calcium pump on red blood cells) and the glycophorins are ligands for parasites to invade red blood cells. Future work should aim at uncovering the mechanisms by which these polymorphisms can result in severe malaria protection and investigate the implications of these associations for wider health. Funding: Wellcome Trust, UK Medical Research Council, European Union, and Foundation for the National Institutes of Health as part of the Bill & Melinda Gates Grand Challenges in Global Health Initiative
The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad-Line Region
We present models of the H-emitting broad-line region (BLR) in seven
Seyfert 1 galaxies from the Lick AGN (Active Galactic Nucleus) Monitoring
Project 2011 sample, drawing inferences on the BLR structure and dynamics as
well as the mass of the central supermassive black hole. We find that the BLR
is generally a thick disk, viewed close to face-on, with preferential emission
back toward the ionizing source. The dynamics in our sample range from
near-circular elliptical orbits to inflowing or outflowing trajectories. We
measure black hole masses of for PG 1310108, for Mrk 50,
for Mrk 141, for Mrk 279,
for Mrk 1511, for NGC 4593, and
for Zw 229015. We use these black hole mass
measurements along with cross-correlation time lags and line widths to recover
the scale factor used in traditional reverberation mapping measurements.
Combining our results with other studies that use this modeling technique,
bringing our sample size to 16, we calculate a scale factor that can be used
for measuring black hole masses in other reverberation mapping campaigns. When
using the root-mean-square (rms) spectrum and using the line dispersion to
measure the line width, we find . Finally, we search for correlations between and other AGN
and BLR parameters and find marginal evidence that is correlated with
and the BLR inclination angle, but no significant evidence of a
correlation with the AGN luminosity or Eddington ratio.Comment: 26 pages, 14 figures. Accepted for publication in Ap
Evolutionary trait-based approaches for predicting future global impacts of plant pathogens in the genus Phytophthora
1. Plant pathogens are introduced to new geographical regions ever more frequently as global connectivity increases. Predicting the threat they pose to plant health can be difficult without in‐depth knowledge of behaviour, distribution and spread. Here, we evaluate the potential for using biological traits and phylogeny to predict global threats from emerging pathogens.
2. We use a species‐level trait database and phylogeny for 179 Phytophthora species: oomycete pathogens impacting natural, agricultural, horticultural and forestry settings. We compile host and distribution reports for Phytophthora species across 178 countries and evaluate the power of traits, phylogeny and time since description (reflecting species‐level knowledge) to explain and predict their international transport, maximum latitude and host breadth using Bayesian phylogenetic generalised linear mixed models.
3. In the best‐performing models, traits, phylogeny and time since description together explained up to 90%, 97% and 87% of variance in number of countries reached, latitudinal limits and host range, respectively. Traits and phylogeny together explained up to 26%, 41% and 34% of variance in the number of countries reached, maximum latitude and host plant families affected, respectively, but time since description had the strongest effect.
4. Root‐attacking species were reported in more countries, and on more host plant families than foliar‐attacking species. Host generalist pathogens had thicker‐walled resting structures (stress‐tolerant oospores) and faster growth rates at their optima. Cold‐tolerant species are reported in more countries and at higher latitudes, though more accurate interspecific empirical data are needed to confirm this finding.
5. Policy implications. We evaluate the potential of an evolutionary trait‐based framework to support horizon‐scanning approaches for identifying pathogens with greater potential for global‐scale impacts. Potential future threats from Phytophthora include Phytophthora x heterohybrida, P. lactucae, P. glovera, P. x incrassata, P. amnicola and P. aquimorbida, which are recently described, possibly under‐reported species, with similar traits and/or phylogenetic proximity to other high‐impact species. Priority traits to measure for emerging species may be thermal minima, oospore wall index and growth rate at optimum temperature. Trait‐based horizon‐scanning approaches would benefit from the development of international and cross‐sectoral collaborations to deliver centralised databases incorporating pathogen distributions, traits and phylogeny
The Mre11-Rad50-Nbs1 complex mediates activation of TopBP1 by ATM
The activation of ATR-ATRIP in response to double-stranded DNA breaks (DSBs) depends upon ATM in human cells and Xenopus egg extracts. One important aspect of this dependency involves regulation of TopBP1 by ATM. In Xenopus egg extracts, ATM associates with TopBP1 and thereupon phosphorylates it on S1131. This phosphorylation enhances the capacity of TopBP1 to activate the ATR-ATRIP complex. We show that TopBP1 also interacts with the Mre11-Rad50-Nbs1 (MRN) complex in egg extracts in a checkpoint-regulated manner. This interaction involves the Nbs1 subunit of the complex. ATM can no longer interact with TopBP1 in Nbs1-depleted egg extracts, which suggests that the MRN complex helps to bridge ATM and TopBP1 together. The association between TopBP1 and Nbs1 involves the first pair of BRCT repeats in TopBP1. In addition, the two tandem BRCT repeats of Nbs1 are required for this binding. Functional studies with mutated forms of TopBP1 and Nbs1 suggested that the BRCT-dependent association of these proteins is critical for a normal checkpoint response to DSBs. These findings suggest that the MRN complex is a crucial mediator in the process whereby ATM promotes the TopBP1-dependent activation of ATR-ATRIP in response to DSBs
Implementation of Complex Interventions Lessons Learned From the Patient-Centered Outcomes Research Institute Transitional Care Portfolio
Background:
Despite the well-documented risks to patient safety associated with transitions from one care setting to another, health care organizations struggle to identify which interventions to implement. Multiple strategies are often needed, and studying the effectiveness of these complex interventions is challenging. Objective:
The objective of this study was to present lessons learned in implementing and evaluating complex transitional care interventions in routine clinical care. Research Design:
Nine transitional care study teams share important common lessons in designing complex interventions with stakeholder engagement, implementation, and evaluation under pragmatic conditions (ie, using only existing resources), and disseminating findings in outlets that reach policy makers and the people who could ultimately benefit from the research. Results:
Lessons learned serve as a guide for future studies in 3 areas: (1) Delineating the function (intended purpose) versus form (prespecified modes of delivery of the intervention); (2) Evaluating both the processes supporting implementation and the impact of adaptations; and (3) Engaging stakeholders in the design and delivery of the intervention and dissemination of study results. Conclusion:
These lessons can help guide future pragmatic studies of care transitions
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Are power calculations useful? A multicentre neuroimaging study
There are now many reports of imaging experiments with small cohorts of typical participants that precede large-scale, often multicentre studies of psychiatric and neurological disorders. Data from these calibration experiments are sufficient to make estimates of statistical power and predictions of sample size and minimum observable effect sizes. In this technical note, we suggest how previously reported voxel-based power calculations can support decision making in the design, execution and analysis of cross-sectional multicentre imaging studies. The choice of MRI acquisition sequence, distribution of recruitment across acquisition centres, and changes to the registration method applied during data analysis are considered as examples. The consequences of modification are explored in quantitative terms by assessing the impact on sample size for a fixed effect size and detectable effect size for a fixed sample size. The calibration experiment dataset used for illustration was a precursor to the now complete Medical Research Council Autism Imaging Multicentre Study (MRC-AIMS). Validation of the voxel-based power calculations is made by comparing the predicted values from the calibration experiment with those observed in MRC-AIMS. The effect of non-linear mappings during image registration to a standard stereotactic space on the prediction is explored with reference to the amount of local deformation. In summary, power calculations offer a validated, quantitative means of making informed choices on important factors that influence the outcome of studies that consume significant resources
A Standardised Procedure for Evaluating Creative Systems: Computational Creativity Evaluation Based on What it is to be Creative
Computational creativity is a flourishing research area, with a variety of creative systems being produced and developed. Creativity evaluation has not kept pace with system development with an evident lack of systematic evaluation of the creativity of these systems in the literature. This is partially due to difficulties in defining what it means for a computer to be creative; indeed, there is no consensus on this for human creativity, let alone its computational equivalent. This paper proposes a Standardised Procedure for Evaluating Creative Systems (SPECS). SPECS is a three-step process: stating what it means for a particular computational system to be creative, deriving and performing tests based on these statements. To assist this process, the paper offers a collection of key components of creativity, identified empirically from discussions of human and computational creativity. Using this approach, the SPECS methodology is demonstrated through a comparative case study evaluating computational creativity systems that improvise music
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