Ecophysiology and population genetics of Frangula caroliniana (Walt) Gray (Rhamnaceae)

Frangula caroliniana (Walt.) Gray (or Rhamnus caroliniana Walt.) (Carolina buckthorn) is a woody species distributed throughout the southeastern United States. Due to its ornamental characteristics and the various soil conditions in which it grows, there is interest in promoting the species as a nursery crop within and beyond its native range. Concerns about the invasive potential of F. caroliniana need to be alleviated before it is promoted in horticultural commerce. These concerns are based on the aggressive spread of related species introduced to North America, including Rhamnus cathartica L. (common buckthorn). Thus, I sought to assess the landscape fitness of F. caroliniana by comparing some of its ecophysiological traits to those of R. cathartica . In addition, I determined the genetic structure of F. caroliniana through analysis of populations indigenous to 16 states. Frangula caroliniana fixed carbon at rates that permitted its survival in soils that ranged from dry to wet, but plants with inundated roots did not survive. Cold stratification at 4°C for up to 112 days enhanced seed germination of F. caroliniana, but its seeds were more resistant to germination than were seeds of R. cathartica. Vernal bud break of F. caroliniana occurred 5.7 days later than that of R. cathartica, and depth of cold hardiness of F. caroliniana (-21°C) may permit use of provenance-based selections of the species in regions where winters are harsher than those of the native habitat. While fruit set per unit stem length and unit leaf area of F. caroliniana was only 41% of that of R. cathartica, seedlings of both species established similarly in field soils. Analysis of amplified polymorphism fragment length (AFLP) markers revealed two distinct groups of genotypes of F. caroliniana; the first group was comprised of plants from South Carolina, which had the highest source of genetic variation, and the second consisted of the other sampled F. caroliniana populations from 15 states. I conclude that the fitness for managed landscapes of F. caroliniana is promising, and that F. caroliniana lacks the capacity to be as invasive as R. cathartica

A Candidate Brightest Proto-Cluster Galaxy at z = 3.03

We report the discovery of a very bright (m_R = 22.2) Lyman break galaxy at z = 3.03 that appears to be a massive system in a late stage of merging. Deep imaging reveals multiple peaks in the brightness profile with angular separations of ~0.''8 (~25 h^-1 kpc comoving). In addition, high signal-to-noise ratio rest-frame UV spectroscopy shows evidence for ~5 components based on stellar photospheric and ISM absorption lines with a velocity dispersion of sigma ~460 km s^-1 for the three strongest components. Both the dynamics and high luminosity, as well as our analysis of a LCDM numerical simulation, suggest a very massive system with halo mass M ~ 10^13 M_solar. The simulation finds that all halos at z = 3 of this mass contain sub-halos in agreement with the properties of these observed components and that such systems typically evolve into M ~ 10^14 M_solar halos in groups and clusters by z = 0. This discovery provides a rare opportunity to study the properties and individual components of z ~ 3 systems that are likely to be the progenitors to brightest cluster galaxies.Comment: 14 pages, 3 figures, submitted to ApJ Letter

Transaminase triggered aza-Michael approach for the enantioselective synthesis of piperidine scaffolds

The expanding “toolbox” of biocatalysts opens new opportunities to redesign synthetic strategies to target molecules by incorporating a key enzymatic step into the synthesis. Herein, we describe a general biocatalytic approach for the enantioselective preparation of 2,6-disubstituted piperidines starting from easily accessible pro-chiral ketoenones. The strategy represents a new biocatalytic disconnection, which relies on an ω-TA-mediated aza-Michael reaction. Significantly, we show that the reversible enzymatic process can power the shuttling of amine functionality across a molecular framework, providing access to the desired aza-Michael products

Using Design Interventions to Develop Communication Solutions for Integrated Pest Management

Iowa State University’s (ISU) Integrated Pest Management (IPM) program partnered with the ISU College of Design (COD) to use Design Thinking and other practical design methodologies and theories to identify and develop approaches to address IPM extension and communication issues. ISU IPM met with agriculture industry, program colleagues, and ISU COD faculty to discuss IPM-related needs in agriculture and to determine the program’s primary challenges. ISU COD faculty developed a two-semester course for undergraduate students, allocating various resources to solve these challenges. Undergraduates in the course, as the primary agents and problem solvers, developed various strategies the IPM program and its colleagues could implement. A model of interdisciplinary collaboration was developed, where design and science may function as equal partners in a design education setting. In our collaboration, the partners bought into a design-led process-based methodology that began with identifying IPM communication needs. This project resulted in unique design interventions to communicate IPM to stakeholders and the public, as well as created a model for interdisciplinary cooperation that can be exported to fields outside of agriculture and IPM

Dengue Vector Dynamics (Aedes aegypti) Influenced by Climate and Social Factors in Ecuador: Implications for Targeted Control

Background Dengue fever, a mosquito-borne viral disease, is now the fastest spreading tropical disease globally. Previous studies indicate that climate and human behavior interact to influence dengue virus and vector (Aedes aegypti) population dynamics; however, the relative effects of these variables depends on local ecology and social context. We investigated the roles of climate and socio-ecological factors on Ae. aegypti population dynamics in Machala, a city in southern coastal Ecuador where dengue is hyper-endemic. Methods/Principal findings We studied two proximate urban localities where we monitored weekly Ae. aegypti oviposition activity (Nov. 2010-June 2011), conducted seasonal pupal surveys, and surveyed household to identify dengue risk factors. The results of this study provide evidence that Ae. aegypti population dynamics are influenced by social risk factors that vary by season and lagged climate variables that vary by locality. Best-fit models to predict the presence of Ae. aegypti pupae included parameters for household water storage practices, access to piped water, the number of households per property, condition of the house and patio, and knowledge and perceptions of dengue. Rainfall and minimum temperature were significant predictors of oviposition activity, although the effect of rainfall varied by locality due to differences in types of water storage containers. Conclusions These results indicate the potential to reduce the burden of dengue in this region by conducting focused vector control interventions that target high-risk households and containers in each season and by developing predictive models using climate and non-climate information. These findings provide the region's public health sector with key information for conducting time and location-specific vector control campaigns, and highlight the importance of local socio-ecological studies to understand dengue dynamics. See Text S1 for an executive summary in Spanish

Development of a Biodegradable Subcutaneous Implant for Prolonged Drug Delivery Using 3D Printing

Implantable drug delivery devices offer many advantages over other routes of drug delivery. Most significantly, the delivery of lower doses of drug, thus, potentially reducing side-effects and improving patient compliance. Three dimensional (3D) printing is a flexible technique, which has been subject to increasing interest in the past few years, especially in the area of medical devices. The present work focussed on the use of 3D printing as a tool to manufacture implantable drug delivery devices to deliver a range of model compounds (methylene blue, ibuprofen sodium and ibuprofen acid) in two in vitro models. Five implant designs were produced, and the release rate varied, depending on the implant design and the drug properties. Additionally, a rate controlling membrane was produced, which further prolonged the release from the produced implants, signalling the potential use of these devices for chronic conditions

Linearization of homogeneous, nearly-isotropic cosmological models

Homogeneous, nearly-isotropic Bianchi cosmological models are considered. Their time evolution is expressed as a complete set of non-interacting linear modes on top of a Friedmann-Robertson-Walker background model. This connects the extensive literature on Bianchi models with the more commonly-adopted perturbation approach to general relativistic cosmological evolution. Expressions for the relevant metric perturbations in familiar coordinate systems can be extracted straightforwardly. Amongst other possibilities, this allows for future analysis of anisotropic matter sources in a more general geometry than usually attempted. We discuss the geometric mechanisms by which maximal symmetry is broken in the context of these models, shedding light on the origin of different Bianchi types. When all relevant length-scales are super-horizon, the simplest Bianchi I models emerge (in which anisotropic quantities appear parallel transported). Finally we highlight the existence of arbitrarily long near-isotropic epochs in models of general Bianchi type (including those without an exact isotropic limit).Comment: 31 pages, 2 figures. Submitted to CQ

MicroRNA Biomarkers for Infectious Diseases: From Basic Research to Biosensing

In the pursuit of improved diagnostic tests for infectious diseases, several classes of molecules have been scrutinized as prospective biomarkers. Small (18–22 nucleotide), non-coding RNA transcripts called microRNAs (miRNAs) have emerged as promising candidates with extensive diagnostic potential, due to their role in numerous diseases, previously established methods for quantitation and their stability within biofluids. Despite efforts to identify, characterize and apply miRNA signatures as diagnostic markers in a range of non-infectious diseases, their application in infectious disease has advanced relatively slowly. Here, we outline the benefits that miRNA biomarkers offer to the diagnosis, management, and treatment of infectious diseases. Investigation of these novel biomarkers could advance the use of personalized medicine in infectious disease treatment, which raises important considerations for validating their use as diagnostic or prognostic markers. Finally, we discuss new and emerging miRNA detection platforms, with a focus on rapid, point-of-care testing, to evaluate the benefits and obstacles of miRNA biomarkers for infectious disease

Talking SMAAC: A New Tool to Measure Soil Respiration and Microbial Activity

Soil respiration measurements are widely used to quantify carbon fluxes and ascertain soil biological properties related to soil microbial ecology and soil health, yet current methods to measure soil respiration either require expensive equipment or use discrete spot measurements that may have limited accuracy, and neglect underlying response dynamics. To overcome these drawbacks, we developed an inexpensive setup for measuring CO2 called the soil microbial activity assessment contraption (SMAAC). We then compared the SMAAC with a commercial infrared gas analyzer (IRGA) unit by analyzing a soil that had been subjected to two different management practices: grass buffer vs. row crop cultivation with tillage. These comparisons were done using three configurations that detected (1) in situ soil respiration, (2) CO2 burst tests, and (3) substrate induced respiration (SIR), a measure of active microbial biomass. The SMAAC provided consistent readings with the commercial IRGA unit for all three configurations tested, showing that the SMAAC can perform well as an inexpensive yet accurate tool for measuring soil respiration and microbial activity