Neurotoxic Shellfish Poisoning

Neurotoxic shellfish poisoning (NSP) is caused by consumption of molluscan shellfish contaminated with brevetoxins primarily produced by the dinoflagellate, Karenia brevis. Blooms of K. brevis, called Florida red tide, occur frequently along the Gulf of Mexico. Many shellfish beds in the US (and other nations) are routinely monitored for presence of K. brevis and other brevetoxin-producing organisms. As a result, few NSP cases are reported annually from the US. However, infrequent larger outbreaks do occur. Cases are usually associated with recreationally-harvested shellfish collected during or post red tide blooms. Brevetoxins are neurotoxins which activate voltage-sensitive sodium channels causing sodium influx and nerve membrane depolarization. No fatalities have been reported, but hospitalizations occur. NSP involves a cluster of gastrointestinal and neurological symptoms: nausea and vomiting, paresthesias of the mouth, lips and tongue as well as distal paresthesias, ataxia, slurred speech and dizziness. Neurological symptoms can progress to partial paralysis; respiratory distress has been recorded. Recent research has implicated new species of harmful algal bloom organisms which produce brevetoxins, identified additional marine species which accumulate brevetoxins, and has provided additional information on the toxicity and analysis of brevetoxins. A review of the known epidemiology and recommendations for improved NSP prevention are presented

Peroxisome Proliferator-Activated Receptors Alpha, Beta, and Gamma mRNA and Protein Expression in Human Fetal Tissues

Peroxisome proliferator-activated receptors (PPARs) regulate lipid and glucose homeostasis, are targets of pharmaceuticals, and are also activated by environmental contaminants. Almost nothing is known about expression of PPARs during human fetal development. This study examines expression of PPARα, β, and γ mRNA and protein in human fetal tissues. With increasing fetal age, mRNA expression of PPARα and β increased in liver, but PPARβ decreased in heart and intestine, and PPARγ decreased in adrenal. Adult and fetal mean expression of PPARα, β, and γ mRNA did not differ in intestine, but expression was lower in fetal stomach and heart. PPARα and β mRNA in kidney and spleen, and PPARγ mRNA in lung and adrenal were lower in fetal versus adult. PPARγ in liver and PPARβ mRNA in thymus were higher in fetal versus adult. PPARα protein increased with fetal age in intestine and decreased in lung, kidney, and adrenal. PPARβ protein in adrenal and PPARγ in kidney decreased with fetal age. This study provides new information on expression of PPAR subtypes during human development and will be important in evaluating the potential for the developing human to respond to PPAR environmental or pharmaceutical agonists

Probing the structure and dynamics of molecular clusters using rotational wavepackets

The chemical and physical properties of molecular clusters can heavily depend on their size, which makes them very attractive for the design of new materials with tailored properties. Deriving the structure and dynamics of clusters is therefore of major interest in science. Weakly bound clusters can be studied using conventional spectroscopic techniques, but the number of lines observed is often too small for a comprehensive structural analysis. Impulsive alignment generates rotational wavepackets, which provides simultaneous information on structure and dynamics, as has been demonstrated successfully for isolated molecules. Here, we apply this technique for the firsttime to clusters comprising of a molecule and a single helium atom. By forcing the population of high rotational levels in intense laser fields we demonstrate the generation of rich rotational line spectra for this system, establishing the highly delocalised structure and the coherence of rotational wavepacket propagation. Our findings enable studies of clusters of different sizes and complexity as well as incipient superfluidity effects using wavepacket methods.Comment: 5 pages, 6 figure

Hachimoji DNA and RNA: A genetic system with eight building blocks

Reported here are DNA and RNA-like systems built from eight (hachi-) nucleotide letters (-moji) that form four orthogonal pairs. This synthetic genetic biopolymer meets the structural requirements needed to support Darwinism, including a polyelectrolyte backbone, predictable thermodynamic stability, and stereoregular building blocks that fit a Schrödinger aperiodic crystal. Measured thermodynamic parameters predict the stability of hachimoji duplexes, allowing hachimoji DNA to double the information density of natural terran DNA. Three crystal structures show that the synthetic building blocks do not perturb the aperiodic crystal seen in the DNA double helix. Hachimoji DNA was then transcribed to give hachimoji RNA in the form of a functioning fluorescent hachimoji aptamer. These results expand the scope of molecular structures that might support life, including life throughout the cosmos

Managing climate risk in water supply systems : materials and tools designed to empower technical professionals to better understand key issues

This manual has been developed as a learning tool to be used with a companion series of practical exercises. They have been developed to provide a hands-on approach to learning key concepts in hydrology and climate science as they relate to climate risk management in water supply systems, as introduced in the text

TCR deep sequencing of transgenic RAG-1-deficient mice reveals endogenous TCR recombination: a cause for caution

The utility of T‐cell receptor (TCR) transgenic mice in medical research has been considerable, with applications ranging from basic biology all the way to translational and clinical investigations. Crossing of TCR transgenic mice with either recombination‐activating gene (RAG)‐1 or RAG‐2 knockouts is frequently used to generate mice with a monoclonal T‐cell repertoire. However, low level productive TCR rearrangement has been reported in RAG‐deficient mice expressing transgenic TCRs. Using deep sequencing, we set out to directly examine and quantify the presence of these endogenous TCRs. Our demonstration that functional nontransgenic TCRs are present in nonmanipulated mice has wide reaching ramifications worthy of critical consideration