Prenatal diagnosis of CLCN4-related neurodevelopmental disorder in fetuses with congenital brain anomalies

We report two male fetuses born to a healthy unrelated couple, with agenesis of the corpus callosum identified on detailed 20-week ultrasound scans and confirmed by in-utero MRI. Whole-genome sequencing identified a likely pathogenic missense variant in the CLCN4 gene, establishing this as the causative gene in the family. Pathogenic variants in the CLCN4 gene cause a neurodevelopmental disorder (also called Raynaud-Claes syndrome) inherited in an X-linked pattern. The disorder is characterised by developmental delay, intellectual disability, autism spectrum disorder, epilepsy, mental health conditions, and significant feeding difficulties, predominantly, but not exclusively, affecting males. This is the first report of a prenatal phenotype associated with variants in the CLCN4 gene. The diagnosis of the CLCN4-related neurodevelopmental disorder in this family allowed accurate genetic counseling and discussion of reproductive choices. This leaves uncertainty about the possibility of a postnatal neurodevelopmental phenotype in heterozygous females, which we discuss.     

Narratives Can Motivate Environmental Action: The Whiskey Creek Ocean Acidification Story

Even when environmental data quantify the risks and benefits of delayed responses to rapid anthropogenic change, institutions rarely respond promptly. We propose that narratives complementing environmental datasets can motivate responsive environmental policy. To explore this idea, we relate a case study in which a narrative of economic loss due to regionally rapid ocean acidification—an anthropogenic change—helped connect knowledge with action. We pose three hypotheses to explain why narratives might be particularly effective in linking science to environmental policy, drawing from the literature of economics, environmental policy, and cognitive psychology. It seems that yet-untold narratives may hold similar potential for strengthening the feedback between environmental data and policy and motivating regional responses to other environmental problems.     

Sustainable Rainwater Catchment Systems for Micronesian Atoll Communities

Atoll island communities rely on rainwater catchment systems (RWCS) as a primary method of storing freshwater. However, stored freshwater can be depleted during times of drought, requiring importation of water to sustain community living. To maintain adequate water supply under future climatic conditions, the functioning of RWCS for atoll communities must be analyzed and optimal designs must be adopted. In this study, a quantitative analysis of stored daily water volumes is provided for atoll islands within the Federated States of Micronesia (FSM), with Nikahlap Island, Pakein Atoll, and a generic island in western FSM used as representative cases. Using a daily water balance model for the RWCS, baseline conditions are simulated for the 1997‐1999 time period, during which an intense El Niño‐induced drought occurred, and a sensitivity analysis is performed to quantify the influence of RWCS features on water system outputs, whereupon an optimal RWCS design using existing infrastructure is analyzed. Results indicate the strong influence of catchment area, system efficiency, and storage capacity on water volumes and the depletion of water during dry seasons and drought periods using current RWCS infrastructure. Adequate storage can be maintained during a major drought if unused RWCS features are employed and if minimal rationing is adopted. Study results provide water resource managers and government officials with valuable data for consideration in water security measures.     

Nest- and colony-mate recognition in polydomous colonies of meat ants (Iridomyrmex purpureus)

Workers of polydomous colonies of social insects must recognize not only colony-mates residing in the same nest but also those living in other nests. We investigated the impact of a decentralized colony structure on colony- and nestmate recognition in the polydomous Australian meat ant (Iridomyrmex purpureus). Field experiments showed that ants of colonies with many nests were less aggressive toward alien conspecifics than those of colonies with few nests. In addition, while meat ants were almost never aggressive toward nestmates, they were frequently aggressive when confronted with an individual from a different nest within the same colony. Our chemical analysis of the cuticular hydrocarbons of workers using a novel comprehensive two-dimensional gas chromatography technique that increases the number of quantifiable compounds revealed both colony- and nest-specific patterns. Combined, these data indicate an incomplete transfer of colony odor between the nests of polydomous meat ant colonies.     

Ecological opportunity and phenotypic plasticity interact to promote character displacement and species coexistence

We investigated the roles of resource availability and phenotypic plasticity in promoting ecological character displacement (i.e., trait evolution stemming from resource competition between species). Because ecological character displacement generates new populations that differ in resource use, this process should only occur when exploitable resources are available. We tested this hypothesis in two species of spadefoot toads (Spea bombifrons and S. multiplicata) whose tadpoles use phenotypic plasticity to develop into either an omnivore morph, which specializes on detritus, or a physically distinctive carnivore morph, which specializes on shrimp. Both species grow best on shrimp, but when reared together, S. bombifrons outcompetes S. multiplicata for shrimp and S. multiplicata outcompetes S. bombifrons for detritus. We found that when each species occurred alone in the field, they produced similar proportions of omnivores and carnivores. When the two species occurred together, however, they underwent ecological character displacement in larval development, with S. multiplicata producing mostly omnivores, and S. bombifrons producing mostly carnivores. We combined observations of natural populations with experiments to evaluate whether such character displacement was only possible when both shrimp and detritus were relatively abundant. Mixed-species ponds contained abundant detritus and shrimp, in contrast with nearby pure-species ponds, which were deficient in one resource. Experiments revealed that S. multiplicata competed poorly when detritus was rare and that S. bombifrons competed poorly when shrimp was rare. In nature, when one of these two resources was scarce, one species was missing, perhaps through competitive exclusion by the species that was the superior competitor for the remaining resource. Thus, ecological character displacement and, therefore, coexistence of close competitors, was only possible when diverse resources were available. Finally, even if exploitable resources are available, character displacement is not guaranteed to transpire if species cannot utilize such resources expeditiously. Phenotypic plasticity provides a general and important mechanism for facilitating resource partitioning. Thus, by facilitating shifts in resource use, phenotypic plasticity and ecological opportunity may often interact to promote divergence and coexistence of competitors.     

Natural and waste materials as metal sorbents in permeable reactive barriers (PRBs)

A range of waste products and natural materials including chitin, fly ash, clay soil, cocoa shell, calcified seaweed and the natural zeolite clinoptilolite were tested in batch experiments to assess their ability to remove metals from a synthetic groundwater containing 10 mg l^–1 Cu, Pb and Zn and 1 mg l^–1 Cd. All had the ability to remove more than 70% of the metals from solution with fly ash being the most efficient, then chitin, clinoptilolite, calcified seaweed, clay soil and cocoa shell. After consideration of geochemical and morphological properties, calcified seaweed and clinoptilolite were shown to have potential as barrier materials. Given current issues with regard to the longevity of zero-valent iron barriers alternative materials could be the key to the future adoption of this remediation technology.     

Development of the escape response in larval walleye pollock (Theragra chalcogramma)

The development of the escape response of walleye pollock (Theragra chalcogramma) larvae from attacks by macrozooplanktonic and small-fish predators was quantified in laboratory experiments. Behavior was recorded using video cameras with silhouette illumination from infrared-emitting diodes and by visual observation. Laboratory-reared larvae of 1, 3, 8, 10, 12, 18, 22, 27, 42 days post-hatching, ranging in size from 4 mm to 10 mm total length, were used in the experiments. Even the youngest larvae were observed to exhibit a fast startle response. The percentage of successful larval escapes from the different predators increased as the larvae developed. Euphausiids (Thysanoessa raschii) and amphipods (Calliopiella pratti) often touched larvae but the larvae were usually able to escape and no successful captures of larvae over 22 days old were observed. Although successful escape from initial attacks by three-spine sticklebacks (Gasterosteus aculeatus) increased ontogenetically, sticklebacks were able to consume most larvae, even of the oldest age group, by repeated attacks. Day-old larvae had the lowest percent of escapes after encounters with jellyfish (Sarsia sp.), but the percentage of escapes increased dramatically for 3-day-old larvae. Escape speeds after an attack also increased with age, and tended to be higher after stickleback attacks and lower after jellyfish attacks. This study revealed that the escape response of larval pollock to attack by predators improves rapidly with development during the early larval stage.