Environmental filtering mediates desert ant community assembly at two spatial scales.

Understanding the mechanisms that maintain species coexistence and determine patterns of community assembly are fundamental goals of ecology. Quantifying the relationship between species traits and stress gradients is a necessary step to disentangle assembly processes and to be able to predict the outcome of environmental change. We examined the hypothesis that desert ant communities are assembled by niche-based processes i.e., environmental filtering and limiting similarity. First, we used population-level morphological trait measurements to study the functional structure of ant communities along a dryland environmental stress gradient. Second, we developed species distribution models for each species to quantify large-scale climatic niche overlap between species. Body, femur, antennal scape, and head lengths were correlated with environmental gradients. Regionally, the ant community was significantly and functionally overdispersed in terms of morphological traits which suggests the importance of competition to ant community structure. Ant community assembly was also strongly influenced by environmental factors as the degree of functional trait divergence, but not phylogenetic divergence, decreased with increasing environmental stress. Thus, environmental stress likely mediates limiting similarity in these desert ecosystems. Species with lower climatic niche overlap were more dissimilar in morphological traits. This suggests that environmental filtering on ant functional traits is important at the scale of species distributions in addition to regional scales. This study shows that environmental and biotic filtering (i.e., niche-based assembly mechanisms) are jointly and non-independently structuring the ant community.

Facilitation with a grain of salt: reduced pollinator visitation is an indirect cost of association with the foundation species creosote bush (Larrea tridentata).

PREMISE: In arid ecosystems, shrub facilitation is a critical process driving plant community structure and assembly, often resulting in increased densities of annual plants beneath shrub canopies. Pollinator-mediated interactions can have fitness consequences for both plant interactors but are largely unexplored as an indirect consequence of direct shrub-annual facilitation. METHODS: We tested the capacity of the geographically widespread creosote bush (Larrea tridentata) to influence pollinator visitation to its annual understory during its phenological shift into spring flowering. We used small video cameras to record pollinator visitation and foraging behavior on potted transplants of a representative flowering annual. We concurrently evaluated L. tridentata's positive role as a foundation plant in this system by measuring the associated plant and arthropod communities and deploying data loggers to measure understory microclimates. RESULTS: Pollinator visitation to the flowering annual desert dandelion, Malacothrix glabrata, was lower when beneath the canopy of L. tridentata, and further declined throughout the study site as L. tridentata entered full bloom. We confirmed the role of L. tridentata as a foundation species in this system through its concurrent, positive effects on annual plant cover (a proxy for biomass), the abundance and richness of the understory arthropod community and its ability to create stable microclimates. CONCLUSIONS: Direct and indirect shrub effects on other species function simultaneously to shift net outcomes even within predominantly net positive facilitation complexes.

Plant networks are more connected by invasive brome and native shrub facilitation in Central California drylands.

Dominant vegetation in many ecosystems is an integral component of structure and habitat. In many drylands, native shrubs function as foundation species that benefit other plants and animals. However, invasive exotic plant species can comprise a significant proportion of the vegetation. In Central California drylands, the facilitative shrub Ephedra californica and the invasive Bromus rubens are widely dispersed and common. Using comprehensive survey data structured by shrub and open gaps for the region, we compared network structure with and without this native shrub canopy and with and without the invasive brome. The presence of the invasive brome profoundly shifted the network measure of centrality in the microsites structured by a shrub canopy (centrality scores increased from 4.3 under shrubs without brome to 6.3, i.e. a relative increase of 42%). This strongly suggests that plant species such as brome can undermine the positive and stabilizing effects of native foundation plant species provided by shrubs in drylands by changing the frequency that the remaining species connect to one another. The net proportion of positive and negative associations was consistent across all microsites (approximately 50% with a total of 14% non-random co-occurrences on average) suggesting that these plant-plant networks are rewired but not more negative. Maintaining resilience in biodiversity thus needs to capitalize on protecting native shrubs whilst also controlling invasive grass species particularly when associated with shrubs.

Obesity in Adolescents: Understanding the Combined Role of Food Security and Emotional and Behavioral Disorders.

PURPOSE: To examine the associations and interactions between levels of food security and emotional and behavioral disorders with obesity in adolescents. METHODS: Multiple logistic regression modeling was used to analyze the association of adolescent obesity with levels of food security and emotional and behavior disorders in children aged 12-17 years using data from National Health Interview Survey 2016-2018 combined years. Presence of emotional and behavioral disorders within food security categories was added to logistic regression modeling to examine interactions. RESULTS: When added individually to multiple logistic regression models, marginal and low food security, Attention Deficit Hyperactivity Disorder (ADHD) and anxiety were associated with increased odds of obesity, but very low food security and depression were not. Within the group of adolescents with very low food security, those with anxiety, depression, or ADHD had a nearly two to three-fold increase in odds of obesity compared to adolescents with very low food security and no emotional and behavioral disorders. A similar increase in the odds of obesity with the presence of anxiety, depression, or ADHD was not seen in the adolescents with high food security. DISCUSSION: This study finds a significant interaction between food security level and emotional and behavioral disorders. The distinction that very low food security in adolescents is only associated with obesity when either anxiety, depression or ADHD are present, but not independently, is an important contribution to understanding complex interactions contributing to obesity.

Teprotumumab for the treatment of chronic thyroid eye disease.

BACKGROUND: Teprotumumab, a novel IGF-1R antibody was recently shown to significantly reduce the signs of active Thyroid eye disease (TED). The current study reviews its efficacy in chronic TED. METHODS: In this retrospective review, consecutive patients with chronic stable TED (>2 years), who had received ≥3 infusions of teprotumumab were included. All patients had measurements of proptosis, and calculation of the CAS and diplopia scores before and after therapy. Five-point strabismus scores were also calculated. Patients who had imaging within 4 months prior to therapy and 6 weeks post therapy underwent orbital 3D volumetric analysis. RESULTS: Thirty-one patients met the inclusion criteria. The mean (SD) duration of TED was 81 months (56) and the mean (SD) number of infusions received by each patient was 7 (2). Mean (SD) reduction in proptosis for each study orbit was 3.5 mm (0.4) and 3 mm (0.3) for the fellow orbit. The CAS response was 90% for the study orbit and 87% for the fellow orbit. Of the 15 patients who had diplopia at baseline, 67% had a clinically significant response, while 47% had complete resolution following treatment. Following teprotumumab, mean (SD) reduction of muscle tissue was 2011 mm3 (1847) in the study orbit and 1620 mm3 (1759) in the fellow orbit. The mean (SD) reduction of fat volume was 2101 mm3 (1681) in the study orbit and 1370 mm3 (1181) in the fellow orbit. CONCLUSION: Teprotumumab significantly reduces proptosis, inflammation, diplopia, strabismus and orbital soft tissue volume in patients with chronic TED.

Facial and Eyelid Changes in Thyroid Eye Disease Are Reversed by Teprotumumab.

Thyroid eye disease (TED) causes orbital soft-tissue expansion. Recent studies have suggested that brow and temple changes may also occur. Teprotumumab, a monoclonal antibody to the insulin-like growth factor 1 receptor reduces soft-tissue swelling in TED. In this study, we quantified the changes to pan facial soft-tissue volumes and eyelid position, following treatment with teprotumumab. METHODS: In this prospective study, consecutive patients who were treated with teprotumumab were appraised for study eligibility. All patients had 3D facial imaging using the Vectra H2. Soft-tissue volume changes in the upper face, periorbita, temples, midface, and lower face were quantified before and after teprotumumab therapy. Furthermore, the marginal reflex distance (MRD)1, MRD2, and intercanthal distance were also measured pretreatment and posttreatment. RESULTS: Twenty-three patients were included in the study. The mean duration of TED was 29 months (38). Following teprotumumab therapy, the mean (SD) decrease in volume for each region was 0.75 mL (0.84) in the upper face, 1.8 mL (1.3) in the periorbital region, 0.17 mL (0.5) in the temples, 1.62 mL (3.16) in the midface, and 2.67 mL (4.6) in the lower face. The mean (SD) decrease in the volume of the full face was 8.9 mL (8.7). There was also a significant reduction in MRD1, MRD2, and the intercanthal space following treatment. There was no relationship between previous steroid use and total body weight reduction and changes in facial volume. CONCLUSION: TED may cause significant tissue expansion across the entire face and this may be reduced following teprotumumab therapy.

Infusion Center Guidelines for Teprotumumab Infusions: Informed Consent, Safety, and Management of Side Effects.

Teprotumumab was the first and only medication approved by the US Food and Drug Administration for the treatment of thyroid eye disease in January 2020. Thyroid eye disease is a complex autoimmune inflammatory disease that can be sight-threatening, debilitating, and disfiguring to affected patients. Although biologic therapies are a preferred treatment option for many complex immunologic and oncologic conditions, their use in ophthalmology and endocrinology may be more novel. The goals of this article are to introduce this new therapeutic option; discuss its mechanism of action, indications for use, administration protocol, infusion precautions, and informed consent; and review common side effects and management.

A checklist for choosing between R packages in ecology and evolution.

The open source and free programming language R is a phenomenal mechanism to address a multiplicity of challenges in ecology and evolution. It is also a complex ecosystem because of the diversity of solutions available to the analyst.Packages for R enhance and specialize the capacity to explore both niche data/experiments and more common needs. However, the paradox of choice or how we select between many seemingly similar options can be overwhelming and lead to different potential outcomes.There is extensive choice in ecology and evolution between packages for both fundamental statistics and for more specialized domain-level analyses.Here, we provide a checklist to inform these decisions based on the principles of resilience, need, and integration with scientific workflows for evidence.It is important to explore choices in any analytical coding environment-not just R-for solutions to challenges in ecology and evolution, and document this process because it advances reproducible science, promotes a deeper understand of the scientific evidence, and ensures that the outcomes are correct, representative, and robust.

Shrub and vegetation cover predict resource selection use by an endangered species of desert lizard.

Globally, no species is exempt from the constraints associated with limited available habitat or resources, and endangered species in particular warrant critical examination. In most cases, these species are restricted to limited locations, and the relative likelihood of resource use within the space they can access is important. Using Gambelia sila, one of the first vertebrate species listed as endangered, we used resource selection function analysis of telemetry and remotely sensed data to identity key drivers of selected versus available locations for this species in Carrizo Plain National Monument, USA. We examined the probability of selection given different resource types. Increasing shrub cover, lower and relatively more flat sites, increasing normalized difference vegetation index, and solar radiation all significantly predicted likelihood of observed selection within the area sampled. Imagery data were also validated with fine-scale field data showing that large-scale contrasts of selection relative to available location patterns for animal species are a useful lens for potential habitat. Key environmental infrastructure such as foundation plant species including shrubs or local differences in the physical attributes were relevant to this endangered species.