Aquatic polymers can drive pathogen transmission in coastal ecosystems.

Gelatinous polymers including extracellular polymeric substances (EPSs) are fundamental to biophysical processes in aquatic habitats, including mediating aggregation processes and functioning as the matrix of biofilms. Yet insight into the impact of these sticky molecules on the environmental transmission of pathogens in the ocean is limited. We used the zoonotic parasite Toxoplasma gondii as a model to evaluate polymer-mediated mechanisms that promote transmission of terrestrially derived pathogens to marine fauna and humans. We show that transparent exopolymer particles, a particulate form of EPS, enhance T. gondii association with marine aggregates, material consumed by organisms otherwise unable to access micrometre-sized particles. Adhesion to EPS biofilms on macroalgae also captures T. gondii from the water, enabling uptake of pathogens by invertebrates that feed on kelp surfaces. We demonstrate the acquisition, concentration and retention of T. gondii by kelp-grazing snails, which can transmit T. gondii to threatened California sea otters. Results highlight novel mechanisms whereby aquatic polymers facilitate incorporation of pathogens into food webs via association with particle aggregates and biofilms. Identifying the critical role of invisible polymers in transmission of pathogens in the ocean represents a fundamental advance in understanding and mitigating the health impacts of coastal habitat pollution with contaminated runoff

Printed dose-recording tag based on organic complementary circuits and ferroelectric nonvolatile memories.

We have demonstrated a printed electronic tag that monitors time-integrated sensor signals and writes to nonvolatile memories for later readout. The tag is additively fabricated on flexible plastic foil and comprises a thermistor divider, complementary organic circuits, and two nonvolatile memory cells. With a supply voltage below 30 V, the threshold temperatures can be tuned between 0 °C and 80 °C. The time-temperature dose measurement is calibrated for minute-scale integration. The two memory bits are sequentially written in a thermometer code to provide an accumulated dose record

Phylogenetically Driven Sequencing of Extremely Halophilic Archaea Reveals Strategies for Static and Dynamic Osmo-response

© 2014. Organisms across the tree of life use a variety of mechanisms to respond to stress-inducing fluctuations in osmotic conditions. Cellular response mechanisms and phenotypes associated with osmoadaptation also play important roles in bacterial virulence, human health, agricultural production and many other biological systems. To improve understanding of osmoadaptive strategies, we have generated 59 high-quality draft genomes for the haloarchaea (a euryarchaeal clade whose members thrive in hypersaline environments and routinely experience drastic changes in environmental salinity) and analyzed these new genomes in combination with those from 21 previously sequenced haloarchaeal isolates. We propose a generalized model for haloarchaeal management of cytoplasmic osmolarity in response to osmotic shifts, where potassium accumulation and sodium expulsion during osmotic upshock are accomplished via secondary transport using the proton gradient as an energy source, and potassium loss during downshock is via a combination of secondary transport and non-specific ion loss through mechanosensitive channels. We also propose new mechanisms for magnesium and chloride accumulation. We describe the expansion and differentiation of haloarchaeal general transcription factor families, including two novel expansions of the TATA-binding protein family, and discuss their potential for enabling rapid adaptation to environmental fluxes. We challenge a recent high-profile proposal regarding the evolutionary origins of the haloarchaea by showing that inclusion of additional genomes significantly reduces support for a proposed large-scale horizontal gene transfer into the ancestral haloarchaeon from the bacterial domain. The combination of broad (17 genera) and deep (≥5 species in four genera) sampling of a phenotypically unified clade has enabled us to uncover both highly conserved and specialized features of osmoadaptation. Finally, we demonstrate the broad utility of such datasets, for metagenomics, improvements to automated gene annotation and investigations of evolutionary processes

Acquisition, Concentration, and Retention of Toxoplasma gondii Oocysts From Seawater by Marine Snails

Toxoplasma gondii is a zoonotic protozoan parasite that has a worldwide distribution. The prevalence of T. gondii infection in southern sea otters approaches 80% in some areas of the California coast, and causes significant sea otter mortality. Sea otters likely acquire the infection by ingestion of oocysts that are transported to the sea in watersheds. The objective of this study was to measure the acquisition, concentration, and retention of T. gondii oocysts by marine snails upon which sea otters prey. Trochid marine snails were experimentally exposed to T. gondii oocysts and microscopy was used to enumerate oocysts in tissue samples and feces from the exposed snails. The snails acquired oocysts, concentrated them, and retained them for up to ten days post-exposure. No naturally-acquired oocysts were detected in field-collected snails. These results suggest that marine snails might play an important role in the transmission of T. gondii to sea otters

Organic inkjet-patterned memory array based on ferroelectric field-effect transistors

An inkjet-patterned, flexible organic memory array was demonstrated using non-volatile ferroelectric field-effect transistors which remained functional below 0.6% tensile strain. Each memory cell is comprised of an addressing transistor and a ferroelectric memory transistor. Less than 20% cross-talk was observed between neighboring cells, and binary memory states in a 7 × 8 array were retained for at least 8 h. Variations among the printed memory transistors were characterized and shown to be caused by different rates of charge trapping in the semiconductor-ferroelectric interface. © 2011 Elsevier B.V. All rights reserved

All printed thin film transistors for flexible electronics

Methods used to deposit and integrate solution-processed materials to fabricate thin film transistors by ink-jet printing are presented. We demonstrate successful integration of a complete additive process with the fabrication of simple prototype TFT backplanes on glass and on flexible plastic substrates, and we discuss the factors that make the process possible. Surface energy control of the gate dielectric layer allows printing of the metal source-drain contacts with gaps as small as 10 um as well as the polymer semiconductor whose electronic properties are very sensitive to surface energy. Silver nanoparticles are used as gate and data metals, and a polythiophene derivative (PQT-12) is used as the semiconducting layer, and the gate dielectric is a polymer. The maximum processing temperature used is 150°C, making the process compatible with flexible substrates. The ION/IOFF ratio is 105-106, and TFT mobilities of 0.05 cm 2/Vs were obtained. The electrical stability of the all-printed transistors was compared to conventional fabrication methods and it is shown to be acceptable for array operation. Here we discuss the yield of the printing process and show arrays that are integrated with E-ink media to form flexible paper-like displays

Draft Genome Sequence of Cobetia sp. UCD-24C, Isolated from Roots and Leaves of the Seagrass Zostera marina.

Here, we present the 4,230,758-bp draft genome for Cobetia sp. UCD-24C. This strain was isolated from Zostera marina roots collected in Woods Hole, Massachusetts, USA