One children's hospital planning and development process to adhere to the FDA recommendation that babies and young children undergo thyroid function testing after receiving an injection of iodine-containing contrast media for medical imaging.

The United States (US) Food and Drug Administration (FDA) has issued multiple statements and guidelines since 2015 on the topic of thyroid function testing in babies and children through 3 years old after receiving iodinated contrast media for medical imaging exams. In April 2023, the FDA adjusted this recommendation to target babies and young children younger than 4 years of age who have a history of prematurity, very low birth weight, or underlying conditions which affect thyroid gland function, largely in response to solid arguments from expert statements from the American College of Radiology (ACR) which is endorsed by the Society for Pediatric Radiology (SPR), Pediatric Endocrinology Society (PES), and the Society for Cardiovascular Angiography & Intervention (SCAI). Herein we describe our approach and development of a clinical care guideline along with the steps necessary for implementation of the plan including alterations in ordering exams requiring iodinated contrast media, automatic triggering of lab orders, reporting, and follow-up, to address the 2022 FDA guidance statement to monitor thyroid function in children after receiving iodinated contrast media. The newly implemented clinical care guideline at Ann and Robert H. Lurie Children's Hospital of Chicago remains applicable following the 2023 updated recommendation from the FDA. We will track patients less than 3 months of age who undergo thyroid function testing following computed tomography (CT), interventional radiology, and cardiac catheterization exams for which an iodinated contrast media is administered as a clinical care quality initiative.

Echocardiographic measured shunt velocity does not predict pulmonary blood flow in patients with Blalock-Thomas-Taussig shunt.

INTRODUCTION: Catheterisation is the gold standard used to evaluate pulmonary blood flow in patients with a Blalock-Thomas-Taussig shunt. It involves risk and cannot be performed frequently. This study aimed to evaluate if echocardiographic measurements obtained in a clinical setting correlate with catheterisation-derived pulmonary blood flow in patients with a Blalock-Thomas-Taussig shunt as the sole source of pulmonary blood flow. METHODS: Chart review was performed retrospectively on consecutive patients referred to the catheterisation lab with a Blalock-Thomas-Taussig shunt. Echocardiographic parameters included peak, mean, and diastolic gradients across the Blalock-Thomas-Taussig shunt and forward and reverse velocity time integral across the distal transverse aorta. In addition to direct correlations, we tested a previously published formula for pulmonary blood flow calculated as velocity time integral across the shunt × heart rate × Blalock-Thomas-Taussig shunt area. Catheterisation parameters included pulmonary and systemic blood flow as calculated by the Fick principle. RESULTS: 18 patients were included. The echocardiography parameters and oxygen saturation did not correlate with catheterisation-derived pulmonary blood flow, systemic blood flow, or the ratio of pulmonary to systemic blood flow. As the ratio of reverse to forward velocity time integral across the transverse aorta increased, the probability of shunt stenosis decreased. CONCLUSION: Echocardiographic measurements obtained outside the catheterisation lab do not correlate with catheterisation-derived pulmonary blood flow. The ratio of reverse to forward velocity time integral across the transverse aortic arch may be predictive of Blalock-Thomas-Taussig shunt narrowing; this finding should be investigated further.

Echocardiogram-Guided Balloon Valvuloplasty of the Aortic Valve in Neonates and Infants Reduces Contrast Exposure with Maintained Efficacy and Less Aortic Regurgitation.

Balloon aortic valvuloplasty (BAV) is performed in children with significant aortic stenosis (AS). Traditionally, contrast angiography measures the annulus and assesses aortic regurgitation (AR) after each dilation. Echocardiographic guidance is hypothesized to reduce contrast and radiation exposure, without compromising efficacy or safety. Patients < 10 kg undergoing BAV from 2013 to 2022 were retrospectively investigated. Agreement between echocardiographic and angiographic annulus measurements was assessed. Echocardiogram-guided (eBAV) and traditional angiogram-guided (tBAV) outcomes were compared controlling for weight, critical AS, and other congenital heart disease (CHD). Twelve eBAV and 19 tBAV procedures were performed. The median age was 33 days, median weight was 4.3 kg, 7 patients (23%) had critical AS, and 9 patients (29%) had other CHD. Annulus measurements by intraprocedural echocardiography and angiography displayed excellent correlation (ICC 0.95, p < 0.001). eBAV patients received less contrast (0.5 vs 3.5 ml/kg, p < 0.01). Five recent eBAV procedures were performed contrast free. Radiation exposure was not statistically different between the eBAV and tBAV groups (155 vs 313 µGy·M2, p = 0.12). One eBAV patient (8%) and 3 tBAV patients (16%, p = 0.62) experienced serious adverse events. Technical success (gradient < 35 mmHg and increase in AR by ≤ 1 grade) occurred in 11 eBAV patients (92%) and 16 tBAV patients (84%, p = 0.22). AR increased in 2 eBAV patients (17%) and 8 tBAV patients (44%, p = 0.02). eBAV was associated with similar efficacy and significantly lower contrast exposure and risk of aortic regurgitation. There was strong agreement between aortic valve annulus measurements by intraprocedural echocardiography and angiography, ultimately permitting contrast free BAV.

Elucidating the Roles of Maternal Overcontrol and Warmth in the Development of Childhood Anxiety and Depression: A Moderated Mediation Framework.

Studies have linked childhood anxiety and depression with parenting characterized by high control and low warmth. However, few studies have examined how control and warmth may work together to influence internalizing symptoms in children. Therefore, the goal of this study was to examine the moderating effect of warmth on the relationship between overcontrol and anxiety and depressive symptoms, as well as whether negative thoughts serve as a mediator of these pathways. A total of 182 fourth and fifth grade children completed measures of maternal parenting behavior, negative thoughts, and anxiety and depressive symptoms. Results showed an interaction between overcontrol and warmth for depressive but not anxiety symptoms. Furthermore, low warmth increased the strength of the mediating relationship between overcontrol and depression via thoughts of personal failure. Findings may signal a need for early interventions to address parenting behaviors, such as controlling behaviors, in parents of children at risk for internalizing difficulties.

Occasional long distance dispersal increases spatial synchrony of population cycles.

Spatially separated populations of the same species often exhibit correlated fluctuations in abundance, a phenomenon known as spatial synchrony. Dispersal can generate spatial synchrony. In nature, most individuals disperse short distances with a minority dispersing long distances. The effect of occasional long distance dispersal on synchrony is untested, and theoretical predictions are contradictory. Occasional long distance dispersal might either increase both overall synchrony and the spatial scale of synchrony, or reduce them. We conducted a protist microcosm experiment to test whether occasional long distance dispersal increases or decreases overall synchrony and the spatial scale of synchrony. We assembled replicate 15-patch ring metapopulations of the protist predator Euplotes patella and its protist prey Tetrahymena pyriformis. All metapopulations experienced the same dispersal rate, but differed in dispersal distance. Some metapopulations experienced strictly short distance (nearest neighbour) dispersal, others experienced a mixture of short- and long distance dispersal. Occasional long distance dispersal increased overall spatial synchrony and the spatial scale of synchrony for both prey and predators, though the effects were not statistically significant for predators. As predicted by theory, dispersal generated spatial synchrony by entraining the phases of the predator-prey cycles in different patches, a phenomenon known as phase locking. Our results are consistent with theoretical models predicting that occasional long distance dispersal increases spatial synchrony. However, our results also illustrate that the spatial scale of synchrony need not match the spatial scale of the processes generating synchrony. Even strictly short distance dispersal maintained high spatial synchrony for many generations at spatial scales much longer than the dispersal distance, thanks to phase locking.

Effects of intraspecific phenotypic variation on species coexistence.

Intraspecific variation can promote or inhibit species coexistence, both by increasing species' competitive abilities, and by altering the relative strengths of intraspecific and interspecific competition. Effects of intraspecific variation on coexistence can occur via complementarity of different variants, and via a selection effect: initially-variable populations are more likely to contain highly competitive variants that might determine the ability of the population as a whole to both invade and resist invasion. We tested the effects of intraspecific variation and composition on coexistence by assaying the mutual invasibility of populations of two competing bean weevil species (Callosobruchus maculatus and C. chinensis) when each was initiated with one, three, or five genetically- and phenotypically-distinct lineages. Our results reveal that intraspecific variation is a double-edged sword for species coexistence. Increasing intraspecific variation increased species' abilities to invade, and to resist invasion, via selection effects and intraspecific niche complementarity among conspecific lineages, thereby creating the potential for exclusion among mismatched competitors. But intraspecific variation also increased the scope for resource partitioning, creating the potential for stable coexistence. Stable coexistence occurred only when intraspecific variation caused species to exhibit both relatively evenly-matched competitive abilities and sufficiently-strong resource partitioning. Our work explains the conflicting results of previous studies.

From Here to Eternity--The Theory and Practice of a Really Long Experiment.

In February 1988, Richard Lenski set up 12 replicate populations of a single genotype of Escherichia coli in a simple nutrient medium. He has been following their evolution ever since. Here, Lenski answers provocative questions from Jeremy Fox about his iconic "Long-Term Evolution Experiment" (LTEE). The LTEE is a remarkable case study of the interplay of determinism and chance in evolution-and in the conduct of science.

Moving forward in circles: challenges and opportunities in modelling population cycles.

Population cycling is a widespread phenomenon, observed across a multitude of taxa in both laboratory and natural conditions. Historically, the theory associated with population cycles was tightly linked to pairwise consumer-resource interactions and studied via deterministic models, but current empirical and theoretical research reveals a much richer basis for ecological cycles. Stochasticity and seasonality can modulate or create cyclic behaviour in non-intuitive ways, the high-dimensionality in ecological systems can profoundly influence cycling, and so can demographic structure and eco-evolutionary dynamics. An inclusive theory for population cycles, ranging from ecosystem-level to demographic modelling, grounded in observational or experimental data, is therefore necessary to better understand observed cyclical patterns. In turn, by gaining better insight into the drivers of population cycles, we can begin to understand the causes of cycle gain and loss, how biodiversity interacts with population cycling, and how to effectively manage wildly fluctuating populations, all of which are growing domains of ecological research.

The relative importance of pollinator abundance and species richness for the temporal variance of pollination services.

The relationship between biodiversity and the stability of ecosystem function is a fundamental question in community ecology, and hundreds of experiments have shown a positive relationship between species richness and the stability of ecosystem function. However, these experiments have rarely accounted for common ecological patterns, most notably skewed species abundance distributions and non-random extinction risks, making it difficult to know whether experimental results can be scaled up to larger, less manipulated systems. In contrast with the prolific body of experimental research, few studies have examined how species richness affects the stability of ecosystem services at more realistic, landscape scales. The paucity of these studies is due in part to a lack of analytical methods that are suitable for the correlative structure of ecological data. A recently developed method, based on the Price equation from evolutionary biology, helps resolve this knowledge gap by partitioning the effect of biodiversity into three components: richness, composition, and abundance. Here, we build on previous work and present the first derivation of the Price equation suitable for analyzing temporal variance of ecosystem services. We applied our new derivation to understand the temporal variance of crop pollination services in two study systems (watermelon and blueberry) in the mid-Atlantic United States. In both systems, but especially in the watermelon system, the stronger driver of temporal variance of ecosystem services was fluctuations in the abundance of common bee species, which were present at nearly all sites regardless of species richness. In contrast, temporal variance of ecosystem services was less affected by differences in species richness, because lost and gained species were rare. Thus, the findings from our more realistic landscapes differ qualitatively from the findings of biodiversity-stability experiments.

Assessing Clinical Improvement in School-Based Treatment for Social Anxiety Disorder: Agreement Between Adolescents, Parents, and Independent Evaluators.

The Clinical Global Impressions of Improvement (CGI-I) scale is widely used in clinical trials to monitor clinically meaningful change during treatment. Although it is standard practice in research to have independent evaluators (IEs) complete the CGI-I, this approach is not practical in school and community settings. Few studies have explored the potential utility of other informants, such as youth and parents. Therefore, this study aimed to investigate agreement between IEs and both adolescents and parents in CGI-I improvement ratings in the context of a randomized controlled trial of cognitive-behavioral therapy for social anxiety disorder, as delivered by psychologists and school counselors. Multilevel growth models indicated that IEs were generally more conservative in their ratings of positive treatment response across time and treatment conditions, though greater agreement was observed between parents and IEs by post-intervention and 5-month follow-up. Possible explanations for these findings and suggestions for alternative approaches are discussed.

Can school counselors deliver cognitive-behavioral treatment for social anxiety effectively? A randomized controlled trial.

BACKGROUND: Social anxiety disorder (SAD) typically onsets in adolescence and is associated with multiple impairments. Despite promising clinical interventions, most socially anxious adolescents remain untreated. To address this clinical neglect, we developed a school-based, 12-week group intervention for youth with SAD, Skills for Academic and Social Success (SASS). When implemented by psychologists, SASS has been found effective. To promote dissemination and optimize treatment access, we tested whether school counselors could be effective treatment providers. METHOD: We randomized 138, ninth through 11th graders with SAD to one of three conditions: (a) SASS delivered by school counselors (C-SASS), (b) SASS delivered by psychologists (P-SASS), or (c) a control condition, Skills for Life (SFL), a nonspecific counseling program. Blind, independent, evaluations were conducted with parents and adolescents at baseline, post-intervention, and 5 months beyond treatment completion. We hypothesized that C-SASS and P-SASS would be superior to the control, immediately after treatment and at follow-up. No prediction was made about the relative efficacy of C-SASS and P-SASS. RESULTS: Compared to controls, adolescents treated with C-SASS or P-SASS experienced significantly greater improvement and reductions of anxiety at the end of treatment and follow-up. There were no significant differences between SASS delivered by school counselors and psychologists. CONCLUSION: With training, school counselors are effective treatment providers to adolescents with social anxiety, yielding benefits comparable to those obtained by specialized psychologists. Questions remain regarding means to maintain counselors' practice standards without external support.

Abundance of common species, not species richness, drives delivery of a real-world ecosystem service.

Biodiversity-ecosystem functioning experiments have established that species richness and composition are both important determinants of ecosystem function in an experimental context. Determining whether this result holds for real-world ecosystem services has remained elusive, however, largely due to the lack of analytical methods appropriate for large-scale, associational data. Here, we use a novel analytical approach, the Price equation, to partition the contribution to ecosystem services made by species richness, composition and abundance in four large-scale data sets on crop pollination by native bees. We found that abundance fluctuations of dominant species drove ecosystem service delivery, whereas richness changes were relatively unimportant because they primarily involved rare species that contributed little to function. Thus, the mechanism behind our results was the skewed species-abundance distribution. Our finding that a few common species, not species richness, drive ecosystem service delivery could have broad generality given the ubiquity of skewed species-abundance distributions in nature.

The extended Price equation quantifies species selection on mammalian body size across the Palaeocene/Eocene Thermal Maximum.

Species selection, covariation of species' traits with their net diversification rates, is an important component of macroevolution. Most studies have relied on indirect evidence for its operation and have not quantified its strength relative to other macroevolutionary forces. We use an extension of the Price equation to quantify the mechanisms of body size macroevolution in mammals from the latest Palaeocene and earliest Eocene of the Bighorn and Clarks Fork Basins of Wyoming. Dwarfing of mammalian taxa across the Palaeocene/Eocene Thermal Maximum (PETM), an intense, brief warming event that occurred at approximately 56 Ma, has been suggested to reflect anagenetic change and the immigration of small bodied-mammals, but might also be attributable to species selection. Using previously reconstructed ancestor-descendant relationships, we partitioned change in mean mammalian body size into three distinct mechanisms: species selection operating on resident mammals, anagenetic change within resident mammalian lineages and change due to immigrants. The remarkable decrease in mean body size across the warming event occurred through anagenetic change and immigration. Species selection also was strong across the PETM but, intriguingly, favoured larger-bodied species, implying some unknown mechanism(s) by which warming events affect macroevolution.

Phase-locking and environmental fluctuations generate synchrony in a predator-prey community.

Spatially synchronized fluctuations in system state are common in physical and biological systems ranging from individual atoms to species as diverse as viruses, insects and mammals. Although the causal factors are well known for many synchronized phenomena, several processes concurrently have an impact on spatial synchrony of species, making their separate effects and interactions difficult to quantify. Here we develop a general stochastic model of predator-prey spatial dynamics to predict the outcome of a laboratory microcosm experiment testing for interactions among all known synchronizing factors: (1) dispersal of individuals between populations; (2) spatially synchronous fluctuations in exogenous environmental factors (the Moran effect); and (3) interactions with other species (for example, predators) that are themselves spatially synchronized. The Moran effect synchronized populations of the ciliate protist Tetrahymena pyriformis; however, dispersal only synchronized prey populations in the presence of the predator Euplotes patella. Both model and data indicate that synchrony depends on cyclic dynamics generated by the predator. Dispersal, but not the Moran effect, 'phase-locks' cycles, which otherwise become 'decoherent' and drift out of phase. In the absence of cycles, phase-locking is not possible and the synchronizing effect of dispersal is negligible. Interspecific interactions determine population synchrony, not by providing an additional source of synchronized fluctuations, but by altering population dynamics and thereby enhancing the action of dispersal. Our results are robust to wide variation in model parameters representative of many natural predator-prey or host-pathogen systems. This explains why cyclic systems provide many of the most dramatic examples of spatial synchrony in nature.

Species richness and the temporal stability of biomass production: a new analysis of recent biodiversity experiments.

The relationship between biological diversity and ecological stability has fascinated ecologists for decades. Determining the generality of this relationship, and discovering the mechanisms that underlie it, are vitally important for ecosystem management. Here, we investigate how species richness affects the temporal stability of biomass production by reanalyzing 27 recent biodiversity experiments conducted with primary producers. We find that, in grasslands, increasing species richness stabilizes whole-community biomass but destabilizes the dynamics of constituent populations. Community biomass is stabilized because species richness impacts mean biomass more strongly than its variance. In algal communities, species richness has a minimal effect on community stability because richness affects the mean and variance of biomass nearly equally. Using a new measure of synchrony among species, we find that for both grasslands and algae, temporal correlations in species biomass are lower when species are grown together in polyculture than when grown alone in monoculture. These results suggest that interspecific interactions tend to stabilize community biomass in diverse communities. Contrary to prevailing theory, we found no evidence that species' responses to environmental variation in monoculture predicted the strength of diversity's stabilizing effect. Together, these results deepen our understanding of when and why increasing species richness stabilizes community biomass.

Synchronous dynamics of zooplankton competitors prevail in temperate lake ecosystems.

Although competing species are expected to exhibit compensatory dynamics (negative temporal covariation), empirical work has demonstrated that competitive communities often exhibit synchronous dynamics (positive temporal covariation). This has led to the suggestion that environmental forcing dominates species dynamics; however, synchronous and compensatory dynamics may appear at different length scales and/or at different times, making it challenging to identify their relative importance. We compiled 58 long-term datasets of zooplankton abundance in north-temperate and sub-tropical lakes and used wavelet analysis to quantify general patterns in the times and scales at which synchronous/compensatory dynamics dominated zooplankton communities in different regions and across the entire dataset. Synchronous dynamics were far more prevalent at all scales and times and were ubiquitous at the annual scale. Although we found compensatory dynamics in approximately 14% of all combinations of time period/scale/lake, there were no consistent scales or time periods during which compensatory dynamics were apparent across different regions. Our results suggest that the processes driving compensatory dynamics may be local in their extent, while those generating synchronous dynamics operate at much larger scales. This highlights an important gap in our understanding of the interaction between environmental and biotic forces that structure communities.

The dynamics of community assembly under sudden mixing in experimental microcosms.

Landscape connectivity has been shown to alter community assembly and its consequences. Here we examine how strong, sudden changes in connectivity may affect community assembly by conducting experiments on the effects of "community mixing," situations where previously isolated communities become completely connected with consequent community reorganization. Previous theory indicates that assembly history dictates the outcome of mixing: mixing randomly assembled communities leads to a final community with random representation from the original communities, while mixing communities that were assembled via a long history of colonizations and extinctions leads to strong asymmetry, with one community dominating the other. It also predicts that asymmetry should be stronger in the presence of predators in the system. We experimentally tested and explored this theory by mixing aquatic microcosms inhabited by a complex food web of heterotrophic protists, and algae. Our results confirm the prediction that long assembly history can produce asymmetry under mixing and suggest these dynamics could be important in natural systems. However, in contrast to previous theory we also found asymmetry weaker under mixing of communities with more complex trophic structure.

Biodiversity simultaneously enhances the production and stability of community biomass, but the effects are independent.

To predict the ecological consequences of biodiversity loss, researchers have spent much time and effort quantifying how biological variation affects the magnitude and stability of ecological processes that underlie the functioning of ecosystems. Here we add to this work by looking at how biodiversity jointly impacts two aspects of ecosystem functioning at once: (1) the production of biomass at any single point in time (biomass/area or biomass/ volume), and (2) the stability of biomass production through time (the CV of changes in total community biomass through time). While it is often assumed that biodiversity simultaneously enhances both of these aspects of ecosystem functioning, the joint distribution of data describing how species richness regulates productivity and stability has yet to be quantified. Furthermore, analyses have yet to examine how diversity effects on production covary with diversity effects on stability. To overcome these two gaps, we reanalyzed the data from 34 experiments that have manipulated the richness of terrestrial plants or aquatic algae and measured how this aspect of biodiversity affects community biomass at multiple time points. Our reanalysis confirms that biodiversity does indeed simultaneously enhance both the production and stability of biomass in experimental systems, and this is broadly true for terrestrial and aquatic primary producers. However, the strength of diversity effects on biomass production is independent of diversity effects on temporal stability. The independence of effect sizes leads to two important conclusions. First, while it may be generally true that biodiversity enhances both productivity and stability, it is also true that the highest levels of productivity in a diverse community are not associated with the highest levels of stability. Thus, on average, diversity does not maximize the various aspects of ecosystem functioning we might wish to achieve in conservation and management. Second, knowing how biodiversity affects productivity gives no information about how diversity affects stability (or vice versa). Therefore, to predict the ecological changes that occur in ecosystems after extinction, we will need to develop separate mechanistic models for each independent aspect of ecosystem functioning.

Reliability of measurements of clavicle shaft fracture shortening in adolescents.

BACKGROUND: A relative indication for surgical treatment of midshaft clavicle fractures is shortening ≥2.0 cm. A standard method for determining shortening with routine clavicle radiographs has not been established. This study evaluated the interobserver and intraobserver reliability when measuring shortening of midshaft clavicle fractures in adolescents. METHODS: We identified all clavicle radiographs of simple midshaft clavicle fractures in adolescents from 2006 to 2010. Thirty-two radiographs were chosen following a power analysis for 7 observers. Each film was measured twice by each evaluator using 2 separate methods. Method 1 was the evaluator's method of choice to determine shortening on the digital radiographs. Method 2 was standardized. Intraclass correlation coefficient and confidence intervals (CI) were calculated to determine interrater reliability, and average differences between the 2 time points with 95% CI were calculated to determine intrarater reliability. RESULTS: Interrater reliability for method 1 was 0.771 (95% CI, 0.655-0.865) and 0.743 (95% CI, 0.604-0.851) at the 2 time points for fair agreement. Interrater reliability for method 2 was 0.741 (95% CI, 0.629-0.842) and 0.685 (95% CI, 0.554-0.805) at the 2 time points, for fair and poor agreement, respectively. Neither method was statistically superior to the other. For method 1, the SD for the measurements averaged 3.1 mm. For method 2, the average SD was 3.0 mm. Intrarater reliability for method 1 was 2.62 mm average difference between the 2 time points (95% CI, 2.24-3.00), and for method 2 it was 3.34 mm average (95% CI, 2.88-3.80). Method 2 had a significantly greater difference at the 2 time points than method 1 (P=0.027). CONCLUSIONS: There is only fair agreement among observers when measuring the shortening of clavicle fractures in adolescents on digital clavicle radiographs by either method described. However, as the average difference among measurers was only 3 mm, this is unlikely to influence clinical decision making. A lack of standardization of measurement in previous studies on clavicle fracture treatment may not represent a significant problem. LEVEL OF EVIDENCE: Level III diagnostic study.