The first compilations of Proterozoic eukaryote diversity, published in the 1980s showed a dramatic peak in the Tonian Period (1000–720 Ma), interpreted as the initial radiation of eukaryotes in the marine realm. Over the decades, new discoveries filled in the older part of the record and the peak diminished, but the idea of a Tonian radiation of eukaryotes has remained strong, and is now widely accepted as fact. We present a new diversity compilation based on 181 species and 713 species occurrences from 145 formations ranging in age from 1890 Ma to 720 Ma and find a significant increase in diversity in the Tonian. However, we also find that the number of eukaryotic species through time is highly correlated with the number of formations in our dataset (i.e. eukaryote-bearing formations) through time. This correlation is robust to interpretations of eukaryote affinity, bin size, and bin boundaries. We also find that within-assemblage diversity—a measure thought to circumvent sampling bias—is related to the number of eukaryote-bearing formations through time. Biomarkers show a similar pattern to body fossils, where the rise of eukaryotic biosignatures correlates with increased sampling. We find no evidence that the proportion of eukaryote-bearing versus all fossiliferous formations changed through the Proterozoic, as might be expected if the correlation reflected an increase in eukaryote diversity driving an increase in the number of eukaryote-bearing formations. Although the correlation could reflect a common cause such as changes in sea level driving both diversification and an increase in sedimentary rock volume, we favor the explanation that the pattern of early eukaryote diversity is driven by variations in paleontological sampling.

Maladaptive daydreaming is a distinct syndrome in which the main symptom is excessive vivid fantasising that causes clinically significant distress and functional impairment in academic, vocational and social domains. Unlike normal daydreaming, maladaptive daydreaming is persistent, compulsive and detrimental to one’s life. It involves detachment from reality in favour of intense emotional engagement with alternative realities and often includes specific features such as psychomotor stereotypies (e.g. pacing in circles, jumping or shaking one’s hands), mouthing dialogues, facial gestures or enacting fantasy events. Comorbidity is common, but existing disorders do not account for the phenomenology of the symptoms. Whereas non-specific therapy is ineffective, targeted treatment seems promising. Thus, we propose that maladaptive daydreaming be considered a formal syndrome in psychiatric taxonomies, positioned within the dissociative disorders category. Maladaptive daydreaming satisfactorily meets criteria for conceptualisation as a psychiatric syndrome, including reliable discrimination from other disorders and solid interrater agreement. It involves significant dissociative aspects, such as disconnection from perception, behaviour and sense of self, and has some commonalities with but is not subsumed under existing dissociative disorders. Formal recognition of maladaptive daydreaming as a dissociative disorder will encourage awareness of a growing problem and spur theoretical, research and clinical developments.

Limited analyses based on national samples have assessed whether early attention-deficit/hyperactivity disorder (ADHD) symptoms predict later internalizing and externalizing symptoms in youth and the influence of sex and pubertal timing on subsequent psychiatric symptoms. This study analyzed data (n = 2818) from the Environmental influences on Child Health Outcomes Program national cohort. Analyses used data from early childhood (mean age = 5.3 years) utilizing parent-reported ADHD symptoms to predict rates of internalizing and externalizing symptoms from late childhood/adolescence (mean age = 11.9 years). Within a subsample age at peak height velocity (APHV) acted as a proxy to assess pubertal timing from early childhood (mean age = 5.4 years) to adolescence (mean age = 12.3 years). Early-childhood ADHD symptoms predicted later psychiatric symptoms, including anxiety, depression, aggressive behavior, conduct problems, oppositional defiant disorder, and rule-breaking behavior. Earlier APHV was associated with increased Conduct Disorder symptoms from late childhood to adolescence for females only. A stronger relation between ADHD symptoms and later aggression was observed in females with earlier APHV, whereas this same pattern with aggression, conduct problems and depression was observed in males with later APHV. Clinicians should consider that both young girls and boys with elevated ADHD symptoms, particularly with off-set pubertal timing, may be at risk for later psychiatric symptoms.

Full-count random sampling has been the traditional method of obtaining weed densities. Currently it is the recommended scouting procedure when using HERB, a herbicide selection decision aid. However, alternative methods of scouting that are quicker and more economical need to be investigated. One possibility that has been considered is binomial sampling. Binomial sampling is the procedure by which density is estimated from the number of random quadrats in which the count of individuals is equal to or less than a specified cutoff value. This sampling method has been widely used for insect scouting. There has also been interest in using binomial sampling for weed scouting. However, an economic analysis of this sampling method for weeds has not been performed. In this paper, the results of an economic analysis using simulations with binomial sampling and the HERB model are presented. Full-count sampling was included in the simulations to provide a benchmark for comparison. The comparison was made in terms of economic losses incurred when the estimated weed density obtained from sampling was inaccurate and a herbicide treatment was selected that did not maximize profits. These types of losses are referred to as opportunity losses. The opportunity losses obtained from the simulations indicate that in some situations binomial sampling may be a viable economic alternative to full-count sampling for fields with weed populations that follow a negative binomial distribution, assuming no prior knowledge of weed densities or negative binomial k values.

This paper provides an overview of the U.S. Department of Energy’s (DOE) hydrogen and fuel cell activities within the Office of Energy Efficiency and Renewable Energy (EERE), focusing on key targets, progress towards meeting those targets, and materials-related issues that need to be addressed. The most recent, state-of-the-art data on metrics such as cost, durability, and performance of fuel cell and hydrogen technologies are presented. Key technical accomplishments to date include a 50% reduction in the modeled high volume cost of fuel cells since 2006, and an 80% cost reduction for electrolyzers since 2002. The statuses of various hydrogen production, delivery, and storage technologies are also presented along with a summary of materials-related challenges for hydrogen infrastructure technologies such as compression, dispensing, seals, pipeline materials/embrittlement, and storage materials. Specific examples and areas requiring more research are discussed. Finally, future plans including EERE’s lab consortium approach such as HyMARC (Hydrogen Storage Materials Advanced Research Consortium) and FC-PAD (Fuel Cell Performance and Durability) Consortia, are summarized.

The emergence of hydrogen and fuel cell technologies in transportation and stationary power sectors offers the world important and potentially transformative environmental and energy security benefits. In recent years, research supported by the U.S. Department of Energy’s (DOE) Fuel Cell Technologies Office has contributed substantially to the development of these technologies. Enhanced performance and reduced cost in automotive fuel cells are important examples of achievement. The research investments are clearly paying off, as commercial fuel-cell electric vehicles (FCEVs) are being rolled out by major car manufacturers today. With increasing market penetration of FCEVs, enabling technologies for the affordable and widespread production, storage and delivery of renewable hydrogen are becoming increasingly important. Long term commercial viability of hydrogen and fuel cells in the commercial marketplace will rely on continued materials research on several important fronts. Examples include the discovery and development of: (1) non-platinum-group-metal catalysts for next-generation fuel cells; (2) durable, high-performance photocatalytic materials systems for direct solar water splitting; (3) advanced materials-based systems for low-pressure, high-volumetric-density hydrogen storage; and (4) low-cost, hydrogen-compatible pipeline materials for hydrogen delivery and distribution. Research innovations in macro-, meso- and nano-scale materials are all needed for pushing forward the state-of-the-art in these areas. New approaches in accelerated materials development facilitated by a national Energy Materials Network of advanced scientific resources in theory, computation and experimentation are being adopted at DOE. Application of these approaches to address the key materials challenges in hydrogen and fuel cell technologies are discussed.