Unmasked: The Author of Narrative of a Voyage to the Spanish Main in the Ship Two Friends

In 1819 John Miller of Burlington Arcade, Piccadilly, London, published the Narrative of a Voyage to the Spanish Main in the Ship Two Friends for an anonymous author, a young Englishman.1 The author, calling himself the Narrator, recounted his earlier voyage to Madeira Island, the Dutch island of St. Thomas, and Spanish East Florida. The Narrative paints a revealing portrait of northeast Florida during the waning years of the Second Spanish Period. In his introduction to the 1978 republication of the Narrative John W. Griffin posed two candidates, both named John Miller, for authorship; however, he concluded [w]ithal the author ... remains anonymous. 2 The Narrator\u27s anonymity has persisted, but overlooked sources render his identification possible

Uninvited Guests: A Night at Cedar Point Plantation

In October 1817 a mariner\u27s mistake at the entrance of the St. Johns River and a subsequent mishap proved fortuitous in preserving a rare glimpse of plantation life in Spanish East Florida in a time of turmoil. Documents describing these events reveal details regarding the humiliating dispossession of Spanish authority on Amelia Island and its town of Fernandina, first by filibusters led by Gregor McGregor and later by rogues headed by the pirate Luis Aury

Knots modify the coil–stretch transition in linear DNA polymers

We perform single-molecule DNA experiments to investigate the relaxation dynamics of knotted polymers and examine the steady-state behavior of knotted polymers in elongational fields. The occurrence of a knot reduces the relaxation time of a molecule and leads to a shift in the molecule's coil-stretch transition to larger strain rates. We measure chain extension and extension fluctuations as a function of strain rate for unknotted and knotted molecules. The curves for knotted molecules can be collapsed onto the unknotted curves by defining an effective Weissenberg number based on the measured knotted relaxation time in the low extension regime, or a relaxation time based on Rouse/Zimm scaling theories in the high extension regime. Because a knot reduces a molecule's relaxation time, we observe that knot untying near the coil-stretch transition can result in dramatic changes in the molecule's conformation. For example, a knotted molecule at a given strain rate can experience a stretch-coil transition, followed by a coil-stretch transition, after the knot partially or fully unties.National Science Foundation (U.S.) (Grant CBET-1602406

Hydrogel microparticles for biosensing

Due to their hydrophilic, biocompatible, and highly tunable nature, hydrogel materials have attracted strong interest in the recent years for numerous biotechnological applications. In particular, their solution-like environment and non-fouling nature in complex biological samples render hydrogels as ideal substrates for biosensing applications. Hydrogel coatings, and later, gel dot surface microarrays, were successfully used in sensitive nucleic acid assays and immunoassays. More recently, new microfabrication techniques for synthesizing encoded particles from hydrogel materials have enabled the development of hydrogel-based suspension arrays. Lithography processes and droplet-based microfluidic techniques enable generation of libraries of particles with unique spectral or graphical codes, for multiplexed sensing in biological samples. In this review, we discuss the key questions arising when designing hydrogel particles dedicated to biosensing. How can the hydrogel material be engineered in order to tune its properties and immobilize bioprobes inside? What are the strategies to fabricate and encode gel particles, and how can particles be processed and decoded after the assay? Finally, we review the bioassays reported so far in the literature that have used hydrogel particle arrays and give an outlook of further developments of the field. Keywords: Hydrogel; Biosensor; Microparticle; Multiplex assayNovartis Institutes of Biomedical Research (Presidential Fellowship)Novartis Institutes of Biomedical Research (Education Office)National Cancer Institute (U.S.) (Grant 5R21CA177393-02)National Science Foundation (U.S.) (Grant CMMI-1120724)Institute for Collaborative Biotechnologies (Grant W911NF-09-0001)United States. Army Research Offic

Thermal processing of thermogelling nanoemulsions as a route to tune material properties

Many soft matter systems have properties which depend on their processing history. It is generally accepted that material properties can be finely tuned by carefully directing self-assembly. However, for gelling colloidal systems, it is difficult to characterize such path-dependent effects since the colloidal attraction is often provided by adding another component to the system such as salts or depletants. Therefore, studies of and an understanding of the role of processing on the material properties of attractive colloidal systems are largely lacking. In this work, we systematically studied how processing greatly influences the properties and the microstructures of model attractive colloidal systems. We perform experiments using a thermogelling nanoemulsion as a model system where the isotropic attraction can be precisely tuned via the temperature. The effects of processing conditions on gel formation and properties is tested by performing well-designed sequential temperature jumps. By properly controlling the thermal history, we demonstrate that properties of colloidal gels can be beyond the limit set by direct quenching, which has been a major focus in literature, and that otherwise slow aging of the system associated with a decrease in elasticity can be prevented. Our results provide new experimental evidence of path-dependent rheology and associated microstructures in attractive colloidal systems and provide guidance to future applications in manufacturing complex colloid-based materials.National Science Foundation (U.S.) (DMR – 1419807)Think Global Education Trust (Taiwan) (scholarship

Mechanical signatures of microbial biofilms in micropillar-embedded growth chambers

Biofilms are surface-attached communities of microorganisms embedded in an extracellular matrix and are essential for the cycling of organic matter in natural and engineered environments. They are also the leading cause of many infections, for example, those associated with chronic wounds and implanted medical devices. The extracellular matrix is a key biofilm component that determines its architecture and defines its physical properties. Herein, we used growth chambers embedded with micropillars to study the net mechanical forces (differential pressure) exerted during biofilm formation in situ. Pressure from the biofilm is transferred to the micropillars via the extracellular matrix, and reduction of major matrix components decreases the magnitude of micropillar deflections. The spatial arrangement of micropillar deflections caused by pressure differences in the different biofilm strains may potentially be used as mechanical signatures for biofilm characterization. Hence, we submit that micropillar-embedded growth chambers provide insights into the mechanical properties and dynamics of the biofilm and its matrix.Singapore. National Research Foundation (Singapore-MIT Alliance for Research and Technology (SMART)

Flare energetics: analysis of a large flare on YZ Canis Minoris observed simultaneously in the ultraviolet, optical and radio.

The results of coordinated observations of the dMe star YZ CMi at optical, UV and radio wavelengths during 3-7 February 1983 are presented. YZ CMi showed repeated optical flaring with the largest flare having a magnitude of 3.8 in the U-band. This flare coincided with an IUE exposure which permits a comparison of the emission measure curves of YZ CMi in its flaring and quiescent state. During the flare a downward shift of the transition zone is observed while the radiative losses in the range 10^4^-10^7^K strongly increase. The optical flare is accompanied with a radio flare at 6cm, while at 20cm no emission is detected. The flare is interpreted in terms of optically thick synchrotron emission. We present a combined interpretation of the optical/radio flare and show that the flare can be interpreted within the context of solar two-ribbon/white-light flares. Special attention is paid to the bombardment of dMe atmospheres by particle beams. We show that the characteristic temperature of the heated atmosphere is almost independent of the beam flux and lies within the range of solar white-light flare temperatures. We also show that it is unlikely that stellar flares emit black-body spectra. The fraction of accelerated particles, as follows from our combined optical/radio interpretation is in good agreement with the fraction determined by two-ribbon flare reconnection models

Description of an Intensive Residential Aphasia Treatment Program: Rationale, Clinical Processes, and Outcomes

Purpose: The purpose of this article is to describe the rationale, clinical processes, and outcomes of an intensive comprehensive aphasia program (ICAP). Method: Seventy-three community-dwelling adults with aphasia completed a residentially based ICAP. Participants received 5 hr of daily 1:1 evidence-based cognitivelinguistically oriented aphasia therapy, supplemented with weekly socially oriented and therapeutic group activities over a 23-day treatment course. Standardized measures of aphasia severity and communicative functioning were obtained at baseline, program entry, program exit, and follow-up. Results were analyzed using a Bayesian latent growth curve model with 2 factors representing (a) the initial level and (b) change over time, respectively, for each outcome measure. Results: Model parameter estimates showed reliable improvement on all outcome measures between the initial and final assessments. Improvement during the treatment interval was greater than change observed across the baseline interval, and gains were maintained at follow-up on all measures. Conclusions: The rationale, clinical processes, and outcomes of a residentially based ICAP have been described. ICAPs differ with respect to treatments delivered, dosing parameters, and outcomes measured. Specifying the defining components of complex interventions, establishing their feasibility, and describing their outcomes are necessary to guide the development of controlled clinical trials

The effects of nitroxyl (HNO) on soluble guanylate cyclase activity: interactions at ferrous heme and cysteine thiols

It has been previously proposed that nitric oxide (NO) is the only biologically relevant nitrogen oxide capable of activating the enzyme soluble guanylate cyclase (sGC). However, recent reports implicate HNO as another possible activator of sGC. Herein, we examine the affect of HNO donors on the activity of purified bovine lung sGC and find that, indeed, HNO is capable of activating this enzyme. Like NO, HNO activation appears to occur via interaction with the regulatory ferrous heme on sGC. Somewhat unexpectedly, HNO does not activate the ferric form of the enzyme. Finally, HNO-mediated cysteine thiol modification appears to also affect enzyme activity leading to inhibition. Thus, sGC activity can be regulated by HNO via interactions at both the regulatory heme and cysteine thiols