Shannon Snow, soprano; Paul Feaver, tenor; Leslee Heys, piano; Katie Fang, piano

Shannon Snow, soprano; Paul Feaver, tenor; Leslee Heys, piano; Katie Fang, pianoShannon Snow et al: presented in partial fulfilment of the requirements for Music 440B. -- Katie Fang: presented in partial fulfilment of the requirements for Music 345B

Ontogenetic shifts in trait-mediated mechanisms of plant community assembly

Identifying the processes that maintain highly diverse plant communities remains a central goal in ecology. Species variation in growth and survival rates across ontogeny, represented by tree size classes and life history stage-specific niche partitioning, are potentially important mechanisms for promoting forest diversity. However, the role of ontogeny in mediating competitive dynamics and promoting functional diversity is not well understood, particular in high-diversity systems such as tropical forests. The interaction between interspecific functional trait variation and ontogenetic shifts in competitive dynamics may yield insights into the ecophysiological mechanisms promoting community diversity. We investigated how functional trait (seed size, maximum height, SLA, leaf N, and wood density) associations with growth, survival, and response to competing neighbors differ among seedlings and two size classes of trees in a subtropical rain forest in Puerto Rico. We used a hierarchical Bayes model of diameter growth and survival to infer trait relationships with ontogenetic change in competitive dynamics. Traits were more strongly associated with average growth and survival than with neighborhood interactions, and were highly consistent across ontogeny for most traits. The associations between trait values and tree responses to crowding by neighbors showed significant shifts as trees grew. Large trees exhibited greater growth as the difference in species trait values among neighbors increased, suggesting trait-associated niche partitioning was important for the largest size class. Our results identify potential axes of niche partitioning and performance-equalizing functional trade-offs across ontogeny, promoting species coexistence in this diverse forest community

Multiscale digital Arabidopsis predicts individual organ and whole-organism growth

Understanding how dynamic molecular networks affect wholeorganism physiology, analogous to mapping genotype to phenotype, remains a key challenge in biology. Quantitative models that represent processes at multiple scales and link understanding from several research domains can help to tackle this problem. Such integrated models are more common in crop science and ecophysiology than in the research communities that elucidate molecular networks. Several laboratories have modeled particular aspects of growth in Arabidopsis thaliana, but it was unclear whether these existing models could productively be combined. We test this approach by constructing a multiscale model of Arabidopsis rosette growth. Four existing models were integrated with minimal parameter modification (leaf water content and one flowering parameter used measured data). The resulting framework model links genetic regulation and biochemical dynamics to events at the organ and whole-plant levels, helping to understand the combined effects of endogenous and environmental regulators on Arabidopsis growth. The framework model was validated and tested with metabolic, physiological, and biomass data from two laboratories, for five photoperiods, three accessions, and a transgenic line, highlighting the plasticity of plant growth strategies. The model was extended to include stochastic development. Model simulations gave insight into the developmental control of leaf production and provided a quantitative explanation for the pleiotropic developmental phenotype caused by overexpression of miR156, which was an open question. Modular, multiscale models, assembling knowledge from systems biology to ecophysiology, will help to understand and to engineer plant behavior from the genome to the field. (Résumé d'auteur

Associations among arbuscular mycorrhizal fungi and seedlings are predicted to change with tree successional status

Arbuscular mycorrhizal (AM) fungi in the soil may influence tropical tree dynamics and forest succession. The mechanisms are poorly understood, because the functional characteristics and abundances of tree species and AM fungi are likely to be codependent. We used generalized joint attribute modeling to evaluate if AM fungi are associated with three forest community metrics for a sub-tropical montane forest in Puerto Rico. The metrics chosen to reflect changes during forest succession are: the abundance of seedlings of different successional status, the amount of foliar damage on seedlings of different successional status, and community-weighted mean functional trait values (adult specific leaf area (SLA), adult wood density, and seed mass). We used high-throughput DNA sequencing to identify fungal operational taxonomic units (OTUs) in the soil. Model predictions showed that seedlings of mid- and late-successional species had less leaf damage when the 12 most common AM fungi were abundant compared to when these fungi were absent. We also found that seedlings of mid-successional species were predicted to be more abundant when the 12 most common AM fungi were abundant compared to when these fungi were absent. In contrast, early-successional tree seedlings were predicted to be less abundant when the 12 most common AM fungi were abundant compared to when these fungi were absent. Finally, we showed that, among the 12 most common AM fungi, different AM fungi were correlated with functional trait characteristics of early- or late-successional species. Together, these results suggest that early-successional species might not rely as much as mid- and late-successional species on AM fungi, and AM fungi might accelerate forest succession

Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD

Hematopoietic Cell Transplantation Cures Adenosine Deaminase 2 Deficiency: Report on 30 Patients

PURPOSE: Deficiency of adenosine deaminase 2 (DADA2) is an inherited inborn error of immunity, characterized by autoinflammation (recurrent fever), vasculopathy (livedo racemosa, polyarteritis nodosa, lacunar ischemic strokes, and intracranial hemorrhages), immunodeficiency, lymphoproliferation, immune cytopenias, and bone marrow failure (BMF). Tumor necrosis factor (TNF-α) blockade is the treatment of choice for the vasculopathy, but often fails to reverse refractory cytopenia. We aimed to study the outcome of hematopoietic cell transplantation (HCT) in patients with DADA2. METHODS: We conducted a retrospective study on the outcome of HCT in patients with DADA2. The primary outcome was overall survival (OS). RESULTS: Thirty DADA2 patients from 12 countries received a total of 38 HCTs. The indications for HCT were BMF, immune cytopenia, malignancy, or immunodeficiency. Median age at HCT was 9 years (range: 2-28 years). The conditioning regimens for the final transplants were myeloablative (n = 20), reduced intensity (n = 8), or non-myeloablative (n = 2). Donors were HLA-matched related (n = 4), HLA-matched unrelated (n = 16), HLA-haploidentical (n = 2), or HLA-mismatched unrelated (n = 8). After a median follow-up of 2 years (range: 0.5-16 years), 2-year OS was 97%, and 2-year GvHD-free relapse-free survival was 73%. The hematological and immunological phenotypes resolved, and there were no new vascular events. Plasma ADA2 enzyme activity normalized in 16/17 patients tested. Six patients required more than one HCT. CONCLUSION: HCT was an effective treatment for DADA2, successfully reversing the refractory cytopenia, as well as the vasculopathy and immunodeficiency. CLINICAL IMPLICATIONS: HCT is a definitive cure for DADA2 with > 95% survival

Why Reform Fails : The ‘Politics of Policies’ in Costa Rican Telecommunications Liberalization

As the \u27Washington Consensus\u27 reforms are losing momentum in Latin America, the Inter- American Development Bank (IDB) is calling for shifting the focus from the content of policy choices to the political process of their implementation. As this paper studies the paradigmatic case of telecommunications reform in Costa Rica it underscores the importance of these \u27politics of policies\u27. The analysis finds, however, that the failure of repeated liberalization initiatives was not only due to policy-makers\u27 errors in steering the project through \u27the messy world of politics\u27 (IDB); instead, as liberalization remained unpopular, policy content indeed mattered, and only the interaction of both explains the outcome. Particular attention is drawn to the political feed-back effects, as the failed reform, precisely because it had been backed by bi-partisan support, became a catalyst for the disintegration of the country\u27s long-standing two-party system.In dem Maße, in dem die mit dem „Washington Consensus“ verbundenen Reformen in Lateinamerika ins Stocken geraten sind, plädiert die Inter-American Development Bank (IDB) für eine stärkere Berücksichtigung nicht nur der Politikinhalte (policies), sondern auch des politischen Prozesses von deren Umsetzung (politics). Die vorliegende Untersuchung zum paradigmatischen Fall der Reform des Telekommunikationssektors in Costa Rica unterstreicht die Bedeutung dieser „politics of policies“. Sie zeigt allerdings auch, dass Ursache für das Scheiten wiederholter Liberalisierungsinitiativen nicht nur Fehler der Politiker sind, das Vorhaben durch „die unordentliche Welt der politics“ (IDB) zu steuern. Die breite gesellschaftliche Opposition gegen den Liberalisierungskurs bleibt. Nur die Interaktion von beiden, politics und policies, erklärt Verlauf und Ergebnis der Reform. Besonderes Augenmerk widmet die Studie den politischen Rückwirkungen der gescheiterten Reform: Sie wurde, just weil sie von beiden etablierten Parteien unterstützt wurde, zum Katalysator für den Zerfall des seit Jahrzehnten etablierten Zweiparteiensystems des Landes