Species Loss Scenarios Identify Canada's Northern Ecosystems as Disproportionately Vulnerable

ABSTRACT Aim Amid ongoing and accelerating global change, predicting the ecological consequences of future species loss is important for prioritising conservation actions to protect biodiversity. Species richness has long been thought to protect communities from species loss by providing ecological redundancy, whereby the loss of any one species hardly impacts the integrity of the wider community due to overlap in species' ecological roles. However, the extent to which species richness will buffer the impacts of future species loss remains unclear due to concurrent variation in both the distribution and ecological roles of species likely to be lost. Location Canada. Taxon Terrestrial vertebrates. Methods To understand how future species loss threatens ecosystems and whether species richness mitigates this threat, we simulated the loss of imperilled taxa from Canadian ecosystems across spatial scales and measured the extent to which community functional and interaction (predator–prey) diversity, two important components of ecosystem integrity, declined. Results We report that, despite harbouring far fewer species at risk, northern ecosystems are disproportionately vulnerable, whereby the loss of imperilled taxa could result in up to 25% and 20% declines in functional and interaction diversity, respectively. Surprisingly, despite high species richness, some southern ecosystems containing high numbers of imperilled taxa were also vulnerable, indicating that richness alone is likely insufficient at predicting community vulnerability to species loss. Main Conclusions Together, these findings demonstrate the need to account for future species loss when evaluating the vulnerability of Earth's ecosystems and highlight the importance of conserving species at risk, specifically in northern communities where they potentially play outsized roles in structuring and maintaining the integrity of ecosystems.

French guidelines for the management of atopic dermatitis

Associations Between Relational Ethics With Parental Marital Quality and Family Adversity in Family of Origin

ABSTRACT In this study, we examined whether family adversity and parental marital quality were associated with family‐of‐origin relational ethics, a hallmark feature of contextual therapy theory. Data were collected from 211 adult clients at a university‐based therapy center between 2014 and 2018. A three‐step hierarchical regression model was tested, controlling for age and gender. Parental marital happiness and parental infidelity, as well as indicators of family adversity such as physical abuse experiences and living with a parent or caregiver with drug dependence in childhood, significantly correlated with family‐of‐origin relationships. The entire model explained 45% of the variance of the outcome. Findings provide empirical evidence of the relationship between recalled experiences of family adversity, parental marital quality, and relational ethics in one's family, as hypothesized by contextual therapy theory. Clinical implications of these findings include the need for a thorough assessment of family‐of‐origin factors and relational dynamics when working with adult individuals.

CASPR2 Autoimmune Antibodies Induce Neuronal Hyperactivity in Human Brain Organoids

ABSTRACT Gestational transfer of brain‐reactive antibodies is a risk factor for neurodevelopmental disorders. Contactin‐associated protein‐like 2 (CASPR2) is a known target for pathogenic maternal autoantibodies which have been proposed to interfere with fetal neurodevelopment. However, the impact of CASPR2 antibodies on human brain development remains largely unknown. Here, to better understand the neurophysiological changes that occur in the presence of these pathogenic autoantibodies, we cultured unguided human neural organoids for a period of 6‐months in media containing anti‐CASPR2 antibodies. We then performed neurophysiological characterization via whole‐cell patch‐clamp and calcium imaging in acute organoid slices. Our results reveal that CASPR2 antibody exposure increased spontaneous synaptic activity, enhanced the maximal frequency of action potential firing and of spontaneous network activity. These findings are consistent with a state of neuronal hyperexcitability, a phenotype which is observed in several models of neurodevelopmental disorders. Mechanistically, the alterations observed in action potential waveform are in accordance with a role for CASPR2 in the regulation of voltage‐gated potassium channels and a pathological role for CASPR2 autoantibodies in driving neuronal hyperexcitability.

More Seats at the Table: Bringing Linguistics Behind Bars

Substitution of Fe 3+ into anorthite in oxidized, Al‐deficient ferrobasaltic systems with implications for the petrogenesis of angrite meteorites

Abstract Angrite meteorites are critically silica‐undersaturated igneous rocks with high Ca/Al and Fe/Mg, along with depletion in volatile lithophile elements Na and K such that they crystallize anorthite along with olivine and calcic pyroxene. The anorthite in angrites contains substantial Fe, and in NWA 1670 and NWA 1296, it is present at major element levels correlated with deficiency in Al, suggesting abundant Fe 2 O 3 ‐Al 2 O 3 exchange. One possible explanation is that these angrites had higher Fe 3+ contents and their final interstitial melts crystallized under higher oxygen fugacities ( f O 2 ) than those of other angrites. Here, we present melting experiments on angritic compositions over a range of f O 2 conditions. These experiments crystallized anorthite and Ca‐rich pyroxene among other phases, showing that large substitutions of Fe 3+ into Al‐deficient anorthite (a “ferri‐anorthite” component) are natural consequences of angritic melt crystallization at high f O 2 . At face value, these experiments suggest substantial anorthite Fe 2 O 3 ‐Al 2 O 3 exchange in NWA 1670 and NWA 1296 due to fractionated magmas crystallizing near the surface of the angrite parent body under oxidizing conditions. However, the inferred f O 2 is several log units higher than the iron‐wüstite redox buffer and even higher than the fayalite–magnetite–quartz redox buffer. While extensive fractional crystallization might raise f O 2 by ~1 log unit by removal of ferrosilicates, it seems unlikely to explain the occurrence of this phase. The presence of Fe 3+ ‐rich anorthite might be attributed to rapid crystallization driving kinetic incorporation of excess Fe and disequilibrium degassing of SO 2 from a small dissolved sulfate component, leading to metastable preservation of this phase.

Passive Acoustic Monitoring Reveals Temporal and Environmental Drivers of the Cetacean Community in the Southern Great Barrier Reef

ABSTRACT Monitoring cetaceans in Australia's Great Barrier Reef (GBR) is essential for understanding their ecological roles and informing conservation, yet traditional visual surveys are limited by logistical constraints. Passive acoustic monitoring (PAM) offers a complementary solution, particularly in acoustically complex coral‐reef habitats of the southern GBR. Over 2 years, we deployed an autonomous recorder at Lady Elliot Island to document cetacean presence and assess environmental associations. We detected vocalizations from humpback whales ( Megaptera novaeangliae ), dwarf minke whales ( Balaenoptera acutorostrata subsp.), and delphinids, likely spinner ( Stenella longirostris ) and/or bottlenose dolphins ( Tursiops spp.). Humpback whale song dominated recordings from June through October, while dwarf minke whale “Star‐Wars” calls occurred from May to August, marking the first acoustic evidence of this subspecies within the southern GBR. Dwarf minke whale detections correlated positively with chlorophyll‐ a concentration, whereas humpback whale detections were negatively associated with wind speed. Rorqual vocalizations declined during periods of elevated anthropogenic noise, while odontocete detections remained unaffected. These results highlight PAM's effectiveness for detecting cetaceans within complex reef soundscapes and suggest acoustic niche partitioning among taxa. These critical baseline data inform management strategies for understudied GBR cetacean populations and establish a robust framework for future long‐term monitoring efforts and effective conservation actions.

Dominique Bergmann

Dominique Bergmann, Stanford University (USA) and the Howard Hughes Medical Institute (USA).

SPEECHLESS duplication in grasses expands potential for environmental regulation of stomatal development

Summary Plants regulate stomatal development and function to acquire atmospheric carbon dioxide for photosynthesis while minimizing water loss. The ancestral basic helix–loop–helix transcription factor (TF) gene that drove stomata production in early land plants diversified to become paralogs SPEECHLESS ( SPCH ), MUTE , and FAMA . Extant grasses exhibit a particularly interesting set of duplications and losses of SPCH . Using phylogenetic methods, we tracked the history of SPCH duplications. Brachypodium distachyon and Oryza sativa plants bearing mutations in either SPCH1 or SPCH2 , and B. distachyon plants with SPCH1 or SPCH2 translational reporters were assayed under different environmental conditions for their effects on stomatal development. We identified the Poaceae‐specific rho whole‐genome duplication as the origin of SPCH1 and SPCH2 and demonstrated that both paralogs remain under selection. We found paralog‐specific divergence in response to two environmental perturbations in both B. distachyon and O. sativa . Plausible molecular mechanisms underpinning paralog divergence and cellular mechanisms driving the stomatal phenotypes are supported by analyses of BdSPCH1 and BdSPCH2 RNA and protein expression and by sequence variation among grasses. These studies suggest ways in which a duplication of a key stomatal regulator enables adaptation and could inform genetic strategies to mitigate anticipated stressors in agronomically important plants.

Causes and consequences of bacterial local adaptation via MGEs in the plant microbiome

Summary Adaptations that enable plant‐associated bacteria to fill disparate niches comprise a critical component of microbial diversity. Genes that confer locally adaptive bacterial traits, ranging from heavy metal resistance to pathogen or symbiont infectivity, often reside within mobile genetic elements (MGEs) that can move between genomes. While MGEs may speed microbial adaptation, they also have selfish fitness interests and potentially separate evolutionary trajectories from their host genome. MGEs can also impose physiological burdens and be limited in the transmissibility of function across hosts, which likely constrains bacterial local adaptation. Given these constraints, the prevalence of adaptive loci on potentially exploitative MGEs poses a dilemma: how do fitness conflicts and alignments between MGEs and the main replicon shape bacterial local adaptation and impact plant hosts? We synthesize research on ways MGEs confer rapid, niche‐specific fitness advantages to bacteria, identify factors that promote or constrain bacterial adaptation, and highlight MGE impacts on plants. We focus on large, self‐transmissible MGEs (islands, plasmids, and prophages; though we expect relevance to other MGEs as well) to better understand how MGEs bolster yet constrain bacterial local adaptation. We specifically explore the role of MGEs in shaping bacteria that themselves play a role in expanding or contracting the plant niche.