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Ongoing, rapid innovations in fields ranging from microelectronics, aerospace, and automotive to defense, energy, and health demand new advanced materials at even greater rates and lower costs. Traditional materials R&D methods offer few paths to achieve both outcomes simultaneously. Materials informatics, while a nascent field, offers such a promise through screening, growing databases of materials for new applications, learning new relationships from existing data resources, and building fast predictive models. We highlight key materials informatics successes from the atomic-scale modeling community, and discuss the ecosystem of open data, software, services, and infrastructure that have led to broad adoption of materials informatics approaches. We then examine emerging opportunities for informatics in materials science and describe an ideal data ecosystem capable of supporting similar widespread adoption of materials informatics, which we believe will enable the faster design of materials.
There is strong evidence that people born in winter and in spring have a small increased risk of schizophrenia. As this ‘season of birth’ effect underpins some of the most influential hypotheses concerning potentially modifiable risk exposures, it is important to exclude other possible explanations for the phenomenon.
Here we sought to determine whether the season of birth effect reflects gene-environment confounding rather than a pathogenic process indexing environmental exposure. We directly measured, in 136 538 participants from the UK Biobank (UKBB), the burdens of common schizophrenia risk alleles and of copy number variants known to increase the risk for the disorder, and tested whether these were correlated with a season of birth.
Neither genetic measure was associated with season or month of birth within the UKBB sample.
As our study was highly powered to detect small effects, we conclude that the season of birth effect in schizophrenia reflects a true pathogenic effect of environmental exposure.
Modern water-supply systems — hidden beneath the ground, constructed, expanded, adapted and repaired intermittently by multiple groups of people — are often messy and difficult to comprehend. The ancient water-supply system we consider here is no different — and perhaps even more complex as it was developed over 1200 years and then had a modern city built on top. Despite this, we are beginning to understand how one of the Roman world's most important cities provided its population with water.
The remains of water infrastructure in Constantinople attest to a complex system of water-management and distribution, one that developed from the colony of Byzantium, through the growth and eventual decline of the new capital of the Roman empire, until conquest by the Ottomans. Aqueducts — the system of channels, bridges and tunnels designed to carry water through the landscape — were the focus of infrastructure investment in earlier periods, but cisterns for the storage and distribution of water were constructed throughout the time of Byzantine Constantinople.
Objectives: Despite recent development of health technology assessment (HTA) methods, there are still methodological gaps for the assessment of complex health technologies. The INTEGRATE-HTA guidance for effectiveness, economic, ethical, socio-cultural, and legal aspects, deals with challenges when assessing complex technologies, such as heterogeneous study designs, multiple stakeholder perspectives, and unpredictable outcomes. The objective of this article is to outline this guidance and describe the added value of integrating these assessment aspects.
Methods: Different methods were used to develop the various parts of the guidance, but all draw on existing, published knowledge and were supported by stakeholder involvement. The guidance was modified after application in a case study and in response to feedback from internal and external reviewers.
Results: The guidance consists of five parts, addressing five core aspects of HTA, all presenting stepwise approaches based on the assessment of complexity, context, and stakeholder involvement. The guidance on effectiveness, health economics and ethics aspects focus on helping users choose appropriate, or further develop, existing methods. The recommendations are based on existing methods’ applicability for dealing with problems arising with complex interventions. The guidance offers new frameworks to identify socio-cultural and legal issues, along with overviews of relevant methods and sources.
Conclusions: The INTEGRATE-HTA guidance outlines a wide range of methods and facilitates appropriate choices among them. The guidance enables understanding of how complexity matters for HTA and brings together assessments from disciplines, such as epidemiology, economics, ethics, law, and social theory. This indicates relevance for a broad range of technologies.
Policy-makers and practitioners have a need to assess community resilience in disasters. Prior efforts conflated resilience with community functioning, combined resistance and recovery (the components of resilience), and relied on a static model for what is inherently a dynamic process. We sought to develop linked conceptual and computational models of community functioning and resilience after a disaster.
We developed a system dynamics computational model that predicts community functioning after a disaster. The computational model outputted the time course of community functioning before, during, and after a disaster, which was used to calculate resistance, recovery, and resilience for all US counties.
The conceptual model explicitly separated resilience from community functioning and identified all key components for each, which were translated into a system dynamics computational model with connections and feedbacks. The components were represented by publicly available measures at the county level. Baseline community functioning, resistance, recovery, and resilience evidenced a range of values and geographic clustering, consistent with hypotheses based on the disaster literature.
The work is transparent, motivates ongoing refinements, and identifies areas for improved measurements. After validation, such a model can be used to identify effective investments to enhance community resilience. (Disaster Med Public Health Preparedness. 2018;12:127–137)
Arterial wall thickening, stimulated by low-grade systemic inflammation, underlies many cardiovascular events. As diet is a significant moderator of systemic inflammation, the dietary inflammatory index (DIITM) has recently been devised to assess the overall inflammatory potential of an individual’s diet. The primary objective of this study was to assess the association of the DII with common carotid artery–intima-media thickness (CCA–IMT) and carotid plaques. To substantiate the clinical importance of these findings we assessed the relationship of DII score with atherosclerotic vascular disease (ASVD)-related mortality, ischaemic cerebrovascular disease (CVA)-related mortality and ischaemic heart disease (IHD)-related mortality more. The study was conducted in Western Australian women aged over 70 years (n 1304). Dietary data derived from a validated FFQ (completed at baseline) were used to calculate a DII score for each individual. In multivariable-adjusted models, DII scores were associated with sub-clinical atherosclerosis: a 1 sd (2·13 units) higher DII score was associated with a 0·013-mm higher mean CCA–IMT (P=0·016) and a 0·016-mm higher maximum CCA–IMT (P=0·008), measured at 36 months. No relationship was seen between DII score and carotid plaque severity. There were 269 deaths during follow-up. High DII scores were positively associated with ASVD-related death (per sd, hazard ratio (HR): 1·36; 95 % CI 1·15, 1·60), CVA-related death (per sd, HR: 1·30; 95 % CI 1·00, 1·69) and IHD-related death (per sd, HR: 1·40; 95 % CI 1·13, 1·75). These results support the hypothesis that a pro-inflammatory diet increases systemic inflammation leading to development and progression of atherosclerosis and eventual ASVD-related death.
Efforts to address health disparities and achieve health equity are critically dependent on the development of a diverse research workforce. However, many researchers from underrepresented backgrounds face challenges in advancing their careers, securing independent funding, and finding the mentorship needed to expand their research.
Faculty from the University of Maryland at College Park and the University of Wisconsin-Madison developed and evaluated an intensive week-long research and career-development institute—the Health Equity Leadership Institute (HELI)—with the goal of increasing the number of underrepresented scholars who can sustain their ongoing commitment to health equity research.
In 2010-2016, HELI brought 145 diverse scholars (78% from an underrepresented background; 81% female) together to engage with each other and learn from supportive faculty. Overall, scholar feedback was highly positive on all survey items, with average agreement ratings of 4.45-4.84 based on a 5-point Likert scale. Eighty-five percent of scholars remain in academic positions. In the first three cohorts, 73% of HELI participants have been promoted and 23% have secured independent federal funding.
HELI includes an evidence-based curriculum to develop a diverse workforce for health equity research. For those institutions interested in implementing such an institute to develop and support underrepresented early stage investigators, a resource toolbox is provided.
Reintroduction practitioners must often make critical decisions about reintroduction protocols despite having little understanding of the reintroduction biology of the focal species. To enhance the available knowledge on the reintroduction biology of the warru, or black-footed rock-wallaby Petrogale lateralis MacDonnell Ranges race, we conducted a trial reintroduction of 16 captive individuals into a fenced predator and competitor exclosure on the An̲angu Pitjantjatjara Yankunytjatjara Lands in South Australia. We conducted seven trapping sessions and used radio-tracking and camera traps to monitor survival, reproduction and recruitment to the population over 36 months. Blood samples were collected pre-release and during two trapping sessions post-release to assess nutritional health. The survival rate of founders was 63%, with all losses occurring within 10 weeks of release. Post-release blood biochemistry indicated that surviving warru adapted to their new environment and food sources. Female warru conceived within 6 months of release; 28 births were recorded during the study period and 52% of births successfully recruited to the population. Our results suggest that captive-bred warru are capable of establishing and persisting in the absence of introduced predators. However, the high mortality rate immediately post-release, with only a modest recruitment rate, suggests that future releases into areas where predators and competitors are present should use a trial approach to determine the viability of reintroduction. We recommend that future releases of warru into unfenced areas include an intensive monitoring period in the first 3 months post-release followed by a comprehensive long-term monitoring schedule to facilitate effective adaptive management.
Large collections of well-preserved specimens of the ammonite Baculites inornatus Meek (1862) from two lower to middle Campanian localities on the Pacific coast of North America are analyzed quantitatively to examine both variability and evolutionary change of species-level distinguishing characters. To this end, we present a new method of describing the morphology of the biostratigraphically important Upper Cretaceous zonal index fossil Baculites, using five independent shell characters that can be measured quantitatively. We then use this method to test hypotheses of phyletic evolutionary change in B. inornatus specimens collected from Sucia Island, Washington, USA, and Punta San Jose, Baja California, Mexico.
The greatest observed character change is in mature shell size: baculitids from the older of the two outcrops (Sucia islands) show a smaller mean diameter at maturity compared to those of the younger of the two outcrops (Punta San Jose). Other than this phyletic size increase, no other directional changes were observed from specimens collected at sub-meter precision from the 90 m-thick measured stratigraphic section of the Rosario Formation located at Punta San Jose. Importantly, neither the younger nor older baculitid assemblages show a size distribution of mature specimens that can be attributed to sexual dimorphism. We observed fluctuating proportions of individuals with ribs and/or keels through this section; since both characters have been used in previous taxonomic studies to define, or differentiate between, other Baculites species, our results indicate that no single character is sufficient to discriminate species within this lineage, and that there is far more variation of these characters than has previously been accepted. Our methodology can also be used to assess morphologic variation and taxonomic assignments of Baculites species in other biogeographic provinces, as well as to evaluate ecological influences on population variation and to test hypotheses of lineage evolution.
The depth of a trie has been deeply studied when the source which produces the words is a simple source (a memoryless source or a Markov chain). When a source is simple but not an unbiased memoryless source, the expectation and the variance are both of logarithmic order and their dominant terms involve characteristic objects of the source, for instance the entropy. Moreover, there is an asymptotic Gaussian law, even though the speed of convergence towards the Gaussian law has not yet been precisely estimated. The present paper describes a ‘natural’ class of general sources, which does not contain any simple source, where the depth of a random trie, built on a set of words independently drawn from the source, has the same type of probabilistic behaviour as for simple sources: the expectation and the variance are both of logarithmic order and there is an asymptotic Gaussian law. There are precise asymptotic expansions for the expectation and the variance, and the speed of convergence toward the Gaussian law is optimal. The paper first provides analytical conditions on the Dirichlet series of probabilities of a general source under which this Gaussian law can be derived: a pole-free region where the series is of polynomial growth. In a second step, the paper focuses on sources associated with dynamical systems, called dynamical sources, where the Dirichlet series of probabilities is expressed with the transfer operator of the dynamical system. Then, the paper extends results due to Dolgopyat, already generalized by Baladi and Vallée, and shows that the previous analytical conditions are fulfilled for ‘most’ dynamical sources, provided that they ‘strongly differ’ from simple sources. Finally, the present paper describes a class of sources not containing any simple source, where the trie depth has the same type of probabilistic behaviour as for simple sources, even with more precise estimates.
We study the coefficients of algebraic functions
∑n≥0fnzn. First, we recall the too-little-known fact that these coefficients
fn always admit a closed form. Then we study their asymptotics, known to be
of the type fn ~ CAnnα. When the function is a power series
associated to a context-free grammar, we solve a folklore conjecture: the
critical exponents α cannot be 1/3 or −5/2; they in fact
belong to a proper subset of the dyadic numbers. We initiate the study of the
set of possible values for A. We extend what Philippe Flajolet
called the Drmota–Lalley–Woods theorem (which states that
α=−3/2 when the dependency graph associated to the
algebraic system defining the function is strongly connected). We fully
characterize the possible singular behaviours in the non-strongly connected
case. As a corollary, the generating functions of certain lattice paths and
planar maps are not determined by a context-free grammar (i.e.,
their generating functions are not ℕ-algebraic). We give examples of
Gaussian limit laws (beyond the case of the
Drmota–Lalley–Woods theorem), and examples of non-Gaussian
limit laws. We then extend our work to systems involving non-polynomial entire
functions (non-strongly connected systems, fixed points of entire functions with
positive coefficients). We give several closure properties for
ℕ-algebraic functions. We end by discussing a few extensions of our
results (infinite systems of equations, algorithmic aspects).