Using simulations to explore the conditions under which "true" dose-response relationships are detectable for environmental exposures: polychlorinated biphenyls (PCBs) and birthweight: a case study.

In environmental epidemiology, we use systematic reviews to evaluate the evidence of exposure-outcome relationships with an eye towards regulation. Conflicting results across studies thwart consensus on toxicity. In humans, only observational data is available from studies of environmental exposures, complicating the construction of dose-response relationships across the full range of exposure levels.

Solubilization of Membrane Proteins using designed protein WRAPS.

The development of therapies and vaccines targeting integral membrane proteins has been complicated by their extensive hydrophobic surfaces, which can make production and structural characterization difficult. Here we describe a general deep learning-based design approach for solubilizing native membrane proteins while preserving their sequence, fold, and function using genetically encoded protein WRAPs (Water-soluble RFdiffused Amphipathic Proteins) that surround the lipid-interacting hydrophobic surfaces, rendering them stable and water-soluble without the need for detergents. We design WRAPs for both beta-barrel outer membrane and helical multi-pass transmembrane proteins, and show that the solubilized proteins retain the binding and enzymatic functions of the native targets with enhanced stability.

Toxicological evaluation, postmortem case descriptions, and pharmacological activity of N,N-dimethylpentylone and related analogs.

Identification of N,N-dimethylpentylone (DMP) in counterfeit "Ecstasy" and "Molly" tablets poses risk to public health due to its adverse effects. Little information is available regarding the pharmacological activity or relevant blood or tissue concentrations of DMP, and even less is known about other structurally related beta-keto methylenedioxyamphetamine analogs on recreational drug markets, such as N-propyl butylone. Here, a novel toxicological assay utilizing liquid chromatography-tandem quadrupole mass spectrometry was developed and validated for the quantitation of DMP and five related synthetic cathinones [eutylone, pentylone, N-ethyl pentylone (NEP), N-propyl butylone, and N-cyclohexyl butylone], with chromatographic resolution from isomeric variants and quantitation performed by standard addition.

Detection of selected vector-borne pathogens in domestic animals, ectoparasites, and their owners in a rural community in Southwest Guatemala.

Vector-borne pathogens, which are transmitted by blood-feeding arthropods to animals and people, are common in tropical regions where, combined with economic factors, can cause significant public health burden. A community-level study was undertaken in southwestern Guatemala to assess the presence of vector-borne pathogens in blood samples from humans (n = 98), their animals (n = 90), and ectoparasites (n = 83) over a period of 2 weeks. Human capillary blood was collected from participant's index finger, and animal venous blood (chickens, pigs, dogs, and cats) was collected from the jugular or cephalic veins at the enrollment period of a concurrent study.

Wave ripples formed in ancient, ice-free lakes in Gale crater, Mars.

Symmetrical wave ripples identified with NASA's Curiosity rover in ancient lake deposits at Gale crater provide a key paleoclimate constraint for early Mars: At the time of ripple formation, climate conditions must have supported ice-free liquid water on the surface of Mars. These features are the most definitive examples of wave ripples on another planet. The ripples occur in two stratigraphic intervals within the orbitally defined Layered Sulfate Unit: a thin but laterally extensive unit at the base of the Amapari member of the Mirador formation, and a sandstone lens within the Contigo member of the Mirador formation.