18 Works

Data from: Factors essential for L,D-transpeptidase-mediated peptidoglycan cross-linking and β-lactam resistance in Escherichia coli

Christiane Bouchier, Jean-Emmanuel Hugonnet, Michel Arthur, Dominique Mengin-Lecreulx, Yves Brun, Michael Van Nieuwenhze, Louis B Rice, Alejandro Monton, Tanneke Den Blaauwen, Etienne Carbonnelle, Carole Veckerlé & Kuyek Tu
The target of β-lactam antibiotics is the D,D-transpeptidase activity of penicillin-binding proteins (PBPs) for synthesis of 4→3 cross-links in the peptidoglycan of bacterial cell walls. Unusual 3→3 cross-links formed by L,D-transpeptidases were first detected in Escherichia coli more than four decades ago, however no phenotype has previously been associated with their synthesis. Here we show that production of the L,D-transpeptidase YcbB in combination with elevated synthesis of the (p)ppGpp alarmone by RelA lead to full...

Data from: Effects of fertilizer on inorganic soil N in East Africa maize systems: vertical distributions and temporal dynamics

Katherine L. Tully, Jonathan Hickman, Madeline McKenna, Christopher Neill & Cheryl A. Palm
Fertilizer applications are poised to increase across sub-Saharan Africa (SSA), but the fate of added nitrogen (N) is largely unknown. We measured vertical distributions and temporal variations of soil inorganic N following fertilizer application in two maize (Zea mays L.)-growing regions of contrasting soil type. Fertilizer trials were established on a clayey soil in Yala, Kenya, and on a sandy soil in Tumbi, Tanzania, with application rates of 0–200 kg N/ha/yr. Soil profiles were collected...

Data from: Both morph- and species-dependent asymmetries affect reproductive barriers between heterostylous species

Barbara Keller, Jurriaan M. De Vos, Alexander N. Schmidt-Lebuhn, James D. Thomson & Elena Conti
The interaction between floral traits and reproductive isolation is crucial to explaining the extraordinary diversity of angiosperms. Heterostyly, a complex floral polymorphism that optimizes outcrossing, evolved repeatedly and has been shown to accelerate diversification in primroses, yet its potential influence on isolating mechanisms remains unexplored. Furthermore, the relative contribution of pre- versus postmating barriers to reproductive isolation is still debated. No experimental study has yet evaluated the possible effects of heterostyly on pre- and postmating...

Data from: Incompressible fluid plays a mechanical role in the development of passive muscle tension

David A. Sleboda & Thomas J. Roberts
Over short time scales, muscle fibres maintain a nearly constant volume of intracellular fluid. This fluid is essential to normal biochemical function, but its role in determining the mechanical properties of muscle has been considered in only a few theoretical analyses. Here we investigate the mechanical role of fluid in a fundamental property of muscle, its development of passive tension in response to stretch. We test a model of muscle structure in which incompressible fluid...

Data from: Biomass resilience of Neotropical secondary forests

Lourens Poorter, Frans Bongers, T. Mitchell Aide, Angélica M. Almeyda Zambrano, Patricia Balvanera, Justin M. Becknell, Vanessa Boukili, Pedro H. S. Brancalion, Eben N. Broadbent, Robin L. Chazdon, Dylan Craven, Jarcilene S. De Almeida-Cortez, George A. L. Cabral, Ben H. J. De Jong, Julie S. Denslow, Daisy H. Dent, Saara J. DeWalt, Juan M. Dupuy, Sandra M. Durán, Mario M. Espírito-Santo, María C. Fandino, Ricardo G. César, Jefferson S. Hall, José Luis Hernandez-Stefanoni, Catarina C. Jakovac … & Danaë M. A. Rozendaal
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle1. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use2, 3, 4. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major...

Data from: Solute and sediment export from Amazon forest and soybean headwater streams

Shelby H. Riskin, Christopher Neill, KathiJo Jankowski, Alex V. Krusche, Richard McHorney, Helmut Elsenbeer, Marcia N. Macedo, Darlisson Costa Nunes & Stephen Porder
Intensive cropland agriculture commonly increases streamwater solute concentrations and export from small watersheds. In recent decades, the lowland tropics have become the world's largest and most important region of cropland expansion. Although the effects of intensive cropland agriculture on streamwater chemistry and watershed export have been widely studied in temperate regions, their effects in tropical regions are poorly understood. We sampled seven headwater streams draining watersheds in forest (n=3) or soybeans (n=4) to examine the...

Data from: Phylogeny and generic delimitation in Molluginaceae, new pigment data in Caryophyllales, and the new family Corbichoniaceae

Mats Thulin, Abigail J. Moore, Hesham El-Seedi, Anders Larsson, Pascal-Antoine Christin & Erika J. Edwards
The circumscription of Molluginaceae has changed radically in recent years, with Corbichonia being moved to Lophiocarpaceae, Limeum to Limeaceae, Macarthuria to Macarthuriaceae and all species of Hypertelis, except the type, to Kewa in Kewaceae. In a broad analysis of core Caryophyllales using plastid trnK-matK and rbcL sequences, the position of Molluginaceae in a strict sense as sister to the Portulacineae clade is corroborated, as are the positions of Corbichonia, Limeum and Kewa outside the family....

Data from: Nutrient limitation in tropical secondary forests following different management practices

R. Chelsea Nagy, Edward B. Rastetter, Christopher Neill & Stephen Porder
Secondary forests now make up more than half of all tropical forests, and constraints on their biomass accumulation will influence the strength of the terrestrial carbon (C) sink in the coming decades. However the variance in secondary tropical forest biomass for a given stand age and climate is high and our understanding of why is limited. We constructed a model of terrestrial C, nitrogen (N), and phosphorus (P) cycling to examine the influence of disturbance...

Data from: Environmental controls on canopy foliar N distributions in a neotropical lowland forest

Christopher S. Balzotti, Gregory P. Asner, Philip G. Taylor, Cory C. Cleveland, Rebecca Cole, Roberta E. Martin, Megan Nasto, Brooke B. Osborne, Stephen Porder & Alan R. Townsend
Distributions of foliar nutrients across forest canopies can give insight into their plant functional diversity and improve our understanding of biogeochemical cycling. We used airborne remote sensing and Partial Least Squares Regression (PLSR) to quantify canopy foliar nitrogen (N) across ~164 km2 of wet lowland tropical forest in the Osa Peninsula, Costa Rica. We determined the relative influence of climate and topography on the observed patterns of canopy foliar N using a gradient boosting model...

Data from: Muscle–spring dynamics in time-limited, elastic movements

Michael V. Rosario, Gregory P. Sutton, Sheila N. Patek & Gregory S. Sawicki
Muscle contractions that load in-series springs with slow speed over a long duration do maximal work and store the most elastic energy. However, time constraints, such as those experienced during escape and predation behaviours, may prevent animals from achieving maximal force capacity from their muscles during spring-loading. Here, we ask whether animals that have limited time for elastic energy storage operate with springs that are tuned to submaximal force production. To answer this question, we...

Data from: Predicting the evolutionary dynamics of seasonal adaptation to novel climates in Arabidopsis thaliana

Alexandre Fournier-Level, Emily O. Perry, Jonathan A. Wang, Peter T. Braun, Andrew Migneault, Martha D. Cooper, C. Jessica E. Metcalf & Johanna Schmitt
Anticipating the effect of climate change on plants requires understanding its evolutionary consequence on traits and genes in complex realistic environments. How seasonal variation has an impact on the dynamics of adaptation in natural populations remains unclear. We simulated adaptation to different climate change scenarios, grounding our analysis in experimental data and explicitly exploring seasonal variation. Seasonal variation dramatically affected the dynamics of adaptation: Marked seasonality led to genetic differentiation within the population to different...

Data from: A new framework for investigating biotic homogenization and exploring future trajectories: oceanic island plant and bird assemblages as a case study

Kyle C. Rosenblad & Dov F. Sax
Studies of biotic homogenization have focused primarily on characterizing changes that have occurred between some past baseline and the present day. In order to understand how homogenization may change in the future, it is important to contextualize the processes driving these changes. Here, we examine empirical patterns of change in taxonomic similarity among oceanic island plant and bird assemblages. We use these empirical cases to unpack dynamic properties of biotic homogenization, thereby elucidating two important...

Data from: Mitochondrial–nuclear epistasis affects fitness within species but does not contribute to fixed incompatibilities between species of Drosophila

Kristi L. Montooth, Colin D. Meiklejohn, Dawn N. Abt & David M. Rand
Efficient mitochondrial function requires physical interactions between the proteins encoded by the mitochondrial and nuclear genomes. Coevolution between these genomes may result in the accumulation of incompatibilities between divergent lineages. We test whether mitochondrial–nuclear incompatibilities have accumulated within the Drosophila melanogaster species subgroup by combining divergent mitochondrial and nuclear lineages and quantifying the effects on relative fitness. Precise placement of nine mtDNAs from D. melanogaster, D. simulans, and D. mauritiana into two D. melanogaster nuclear...

Data from: Modeling of kidney hemodynamics: probability-based topology of an arterial network

Dmitry D. Postnov, Donald J. Marsh, Thomas H. Braunstein, Niels-Henrik Holstein-Rathlou, Erik A. Martens & Olga Sosnovtseva
Through regulation of the extracellular fluid volume, the kidneys provide important long-term regulation of blood pressure. At the level of the individual functional unit (the nephron), pressure and flow control involves two different mechanisms that both produce oscillations. The nephrons are arranged in a complex branching structure that delivers blood to each nephron and, at the same time, provides a basis for an interaction between adjacent nephrons. The functional consequences of this interaction are not...

Data from: Phylogenomic analyses support traditional relationships within Cnidaria

Felipe Zapata, Freya E. Goetz, Stephen A. Smith, Mark Howison, Stefan Siebert, Samuel H. Church, Steven M. Sanders, Cheryl Lewis Ames, Catherine S. McFadden, Scott C. France, Marymegan Daly, Allen G. Collins, Steven H. D. Haddock, Casey W. Dunn & Paulyn Cartwright
Cnidaria, the sister group to Bilateria, is the most diverse group of animals in terms of morphology, lifecycles, ecology, and development. How this diversity originated and evolved is not well understood because phylogenetic relationships among major cnidarian lineages are unclear, and recent studies present contrasting phylogenetic hypotheses. Here, we use transcriptome data from 15 newly-sequenced species in combination with 26 publicly available genomes and transcriptomes to assess phylogenetic relationships among major cnidarian lineages. Phylogenetic analyses...

Data from: Estimating colony sizes of emerging bats using acoustic recordings

Laura N. Kloepper, Meike Linnenschmidt, Zelda Blowers, Brian Branstetter, Joel Ralston & James A. Simmons
The decline of bats demands more widespread monitoring of populations for conservation and management. Current censusing methods are either prone to bias or require costly equipment. Here, we report a new method using passive acoustics to determine bat count census from overall acoustic amplitude of the emerging bat stream. We recorded the video and audio of an emerging colony of Mexican free-tailed bats from two cave locations across multiple nights. Instantaneous bat counts were calculated...

Data from: Catecholaminergic regulation of learning rate in a dynamic environment

Marieke Jepma, Peter R. Murphy, Matthew R. Nassar, Mauricio Rangel-Gomez, Martijn Meeter & Sander Nieuwenhuis
Adaptive behavior in a changing world requires flexibly adapting one’s rate of learning to the rate of environmental change. Recent studies have examined the computational mechanisms by which various environmental factors determine the impact of new outcomes on existing beliefs (i.e., the ‘learning rate’). However, the brain mechanisms, and in particular the neuromodulators, involved in this process are still largely unknown. The brain-wide neurophysiological effects of the catecholamines norepinephrine and dopamine on stimulus-evoked cortical responses...

Data from: Intraspecific variation in seed dispersal of a Neotropical tree and its relationship to fruit and tree traits

Carol K. Augspurger, Susan E. Franson, Katherine C. Cushman & Helene C. Muller-Landau
The distribution of wind-dispersed seeds around a parent tree depends on diaspore and tree traits, as well as wind conditions and surrounding vegetation. This study of a neotropical canopy tree, Platypodium elegans, explored the extent to which parental variation in diaspore and tree traits explained (1) rate of diaspore descent in still air, (2) distributions of diaspores dispersed from a 40-m tower in the forest, and (3) natural diaspore distributions around the parent tree. The...

Registration Year

  • 2016
    18

Resource Types

  • Dataset
    18

Affiliations

  • Brown University
    18
  • University of Maryland, College Park
    3
  • Columbia University
    2
  • Duke University
    2
  • Smithsonian Tropical Research Institute
    2
  • University of Sao Paulo
    2
  • Woods Hole Research Center
    2
  • University of Amsterdam
    2
  • University of Kansas
    1
  • University of Montana
    1