Ethanol exposure perturbs sea urchin development and disrupts developmental timing.

Ethanol is a known vertebrate teratogen that causes craniofacial defects as a component of fetal alcohol syndrome (FAS). Our results show that sea urchin embryos treated with ethanol similarly show broad skeletal patterning defects, potentially analogous to the defects associated with FAS. The sea urchin larval skeleton is a simple patterning system that involves only two cell types: the primary mesenchymal cells (PMCs) that secrete the calcium carbonate skeleton and the ectodermal cells that provide migratory, positional, and differentiation cues for the PMCs. Perturbations in RA biosynthesis and Hh signaling pathways are thought to be causal for the FAS phenotype in vertebrates. Surprisingly, our results indicate that these pathways are not functionally relevant for the teratogenic effects of ethanol in developing sea urchins. We found that developmental morphology as well as the expression of some ectodermal and PMC genes was delayed by ethanol exposure. Temporal transcriptome analysis revealed significant impacts of ethanol on signaling and metabolic gene expression, and a disruption in the timing of GRN gene expression that includes both delayed and precocious gene expression throughout the specification network. We conclude that the skeletal patterning perturbations in ethanol-treated embryos likely arise from a loss of temporal synchrony within and between the instructive and responsive tissues.

Per- and Polyfluoroalkyl Substance Exposure Risks in US Carceral Facilities, 2022.

Objectives. To assess the US incarcerated population's risk of exposure to per- and polyfluoroalkyl substances (PFASs). Methods. We assessed how many of the 6118 US carceral facilities were located in the same hydrologic unit code watershed boundaries as known or likely locations of PFAS contamination. We conducted geospatial analyses on data aggregated from Environmental Protection Agency databases and a PFAS site tracker in 2022 to model the hydrologically feasible known and presumptive PFAS contamination sites for nearly 2 million incarcerated people. Results. Findings indicate that 5% (∼310) of US carceral facilities have at least 1 known source of PFAS contamination in the same watershed boundary and that it is at a higher elevation than the facility; also 47% (∼2285) have at least 1 presumptive source. A minimum of 990 000 people are incarcerated in these facilities, including at least 12 800 juveniles. Exposure risks faced by incarcerated youths are disproportionately underassessed. Conclusions. The long-term impacts from potential exposures to PFAS are preventable and exacerbate health inequities among incarcerated populations. Widespread public attention to PFASs can be parlayed into broader environmental monitoring for imprisoned people. (Am J Public Health. 2024;114(5):501-510. https://doi.org/10.2105/AJPH.2024.307571).

Naturalizing unnatural death in Los Angeles County jails.

In this paper we use quantitative and qualitative methods to examine how death investigations in Los Angeles County jails disproportionately naturalize death among Black and Latino incarcerated people. Our study is based on an assessment of 58 autopsies, coroner investigator narratives, and toxicology reports produced between 2009 and 2018. We found that the Medical Examiner frequently arrived at natural or undetermined death determinations that minimized the culpability of carceral staff for loss of life that occurred within county jail. In our dataset, Black people were disproportionately classified as natural. Undetermined deaths were almost exclusively Latino. More than 75% of the cases in our study were deaths that occurred before standing trial. Our findings reveal how biomedical knowledge about incarcerated Black and Latino people is used to erase the life-diminishing effects of punishment, neglect, and maltreatment that are central to the project of mass incarceration.

The Environmental Protection Agency in the Early Trump Administration: Prelude to Regulatory Capture.

We explore and contextualize changes at the Environmental Protection Agency (EPA) over the first 6 months of the Trump administration, arguing that its pro-business direction is enabling a form of regulatory capture. We draw on news articles, public documents, and a rapid response, multisited interview study of current and retired EPA employees to (1) document changes associated with the new administration, (2) contextualize and compare the current pro-business makeover with previous ones, and (3) publicly convey findings in a timely manner. The lengthy, combined experience of interviewees with previous Republican and Democratic administrations made them valuable analysts for assessing recent shifts at the Scott Pruitt-led EPA and the extent to which these shifts steer the EPA away from its stated mission to "protect human and environmental health." Considering the extent of its pro-business leanings in the absence of mitigating power from the legislative branch, we conclude that its regulatory capture has become likely-more so than at similar moments in the agency's 47-year history. The public and environmental health consequences of regulatory capture of the EPA will probably be severe and far-reaching.

History of US Presidential Assaults on Modern Environmental Health Protection.

The Trump administration has undertaken an assault on the Environmental Protection Agency (EPA), an agency critical to environmental health. This assault has precedents in the administrations of Ronald Reagan and George W. Bush. The early Reagan administration (1981-1983) launched an overt attack on the EPA, combining deregulation with budget and staff cuts, whereas the George W. Bush administration (2001-2008) adopted a subtler approach, undermining science-based policy. The current administration combines both these strategies and operates in a political context more favorable to its designs on the EPA. The Republican Party has shifted right and now controls the executive branch and both chambers of Congress. Wealthy donors, think tanks, and fossil fuel and chemical industries have become more influential in pushing deregulation. Among the public, political polarization has increased, the environment has become a partisan issue, and science and the mainstream media are distrusted. For these reasons, the effects of today's ongoing regulatory delays, rollbacks, and staff cuts may well surpass those of the administrations of Reagan and Bush, whose impacts on environmental health were considerable.

Community interest and feasibility of using a novel smartphone-based formaldehyde exposure detection technology.

OBJECTIVE: This study is the first community engagement phase of a project to develop a residential formaldehyde detection system. The objectives were to conduct a feasibility assessment for device use, and identify factors associated with concerns about environmental exposure and community interest in this device. DESIGN AND SAMPLE: A cross-sectional, internet-based survey employing community-based participatory research principles was utilized. 147 individuals participated from a focused Waycross, Georgia (58.5%) and broader national sample (41.5%). MEASURES: Variables included acceptable cost and number of testing samples, interest in conducting tests, levels of concern over pollutants, health status, housing, and demographics. RESULTS: The majority of participants desired a system with fewer than 10 samples at ≤$15.00 per sample. Statistically significant higher levels of concern over air quality, formaldehyde exposure, and interest in testing formaldehyde were observed for those with overall worse health status and living in the Waycross, Georgia geographic region. Significant differences in formaldehyde testing interest were observed by health status (OR = 0.31, 95% CI = 0.12-0.81 for home testing) and geographic location (OR = 3.16, 95% CI = 1.22-8.14 for home and OR = 4.06, 95% CI = 1.48-11.12 for ambient testing) in multivariate models. CONCLUSIONS: Geographic location and poorer general health status were associated with concerns over and interest in formaldehyde testing.

A novel systems solution for accurate colorimetric measurement through smartphone-based augmented reality.

Quantifying the colors of objects is useful in a wide range of applications, including medical diagnosis, agricultural monitoring, and food safety. Accurate colorimetric measurement of objects is a laborious process normally performed through a color matching test in the laboratory. A promising alternative is to use digital images for colorimetric measurement, due to their portability and ease of use. However, image-based measurements suffer from errors caused by the non-linear image formation process and unpredictable environmental lighting. Solutions to this problem often perform relative color correction among multiple images through discrete color reference boards, which may yield biased results due to the lack of continuous observation. In this paper, we propose a smartphone-based solution, that couples a designated color reference board with a novel color correction algorithm, to achieve accurate and absolute color measurements. Our color reference board contains multiple color stripes with continuous color sampling at the sides. A novel correction algorithm is proposed to utilize a first-order spatial varying regression model to perform the color correction, which leverages both the absolute color magnitude and scale to maximize the correction accuracy. The proposed algorithm is implemented as a "human-in-the-loop" smartphone application, where users are guided by an augmented reality scheme with a marker tracking module to take images at an angle that minimizes the impact of non-Lambertian reflectance. Our experimental results show that our colorimetric measurement is device independent and can reduce up to 90% color variance for images collected under different lighting conditions. In the application of reading pH values from test papers, we show that our system performs 200% better than human reading. The designed color reference board, the correction algorithm, and our augmented reality guiding approach form an integrated system as a novel solution to measure color with increased accuracy. This technique has the flexibility to improve color reading performance in systems beyond existing applications, evidenced by both qualitative and quantitative experiments on example applications such as pH-test reading.

Three-dimensional neural constructs: a novel platform for neurophysiological investigation.

Morphological and electrophysiological properties of neural cells are substantially influenced by their immediate extracellular surroundings, yet the features of this environment are difficult to mimic in vitro. Therefore, there is a tremendous need to develop a new generation of culture systems that more closely model the complexity of nervous tissue. To this end, we engineered novel electrophysiologically active 3D neural constructs composed of neurons and astrocytes within a bioactive extracellular matrix-based scaffold. Neurons within these constructs exhibited extensive 3D neurite outgrowth, expressed mature neuron-specific cytoskeletal proteins, and remained viable for several weeks. Moreover, neurons assumed complex 3D morphologies with rich neurite arborization and clear indications of network connectivity, including synaptic junctures. Furthermore, we modified whole-cell patch clamp techniques to permit electrophysiological probing of neurons deep within the 3D constructs, revealing that these neurons displayed both spontaneous and evoked electrophysiological action potentials and exhibited functional synapse formation and network properties. This is the first report of individual patch clamp recordings of neurons deep within 3D scaffolds. These tissue engineered cellular constructs provide an innovative platform for neurobiological and electrophysiological investigations, serving as an important step towards the development of more physiologically relevant neural tissue models.

Synaptic amplification versus bistability in motoneuron dendritic processing: a top-down modeling approach.

Motoneurons have been shown to exhibit both bistable firing and synaptic amplification. Both of these behaviors have generally been attributed to a single mechanism-dendritic plateau potentials based on L-type Ca(2+) conductances. However, our recent discovery of a fast-amplification mode calls this into question. Here we examine the possibility that two mechanisms underlie these behaviors, one being a slow-mode bistability mechanism (i.e., the L-type Ca(2+)-conductance-based dendritic plateaus) and the other being a theoretical fast-mode amplification mechanism. A "top-down" motoneuron model that encapsulated these and other hypotheses was developed in which these mechanisms could be explored. The resulting final model simultaneously exhibits synaptic amplification, plateau potential formation, bistable firing patterns, and current-voltage (I-V) and frequency-current (F-I) hystereses. This model suggests that amplification and plateaus are mutually exclusive in the same dendrite/dendritic branch. Thus we predict that plateau generation does not occur in all dendritic branches. This could be readily accomplished by a large degree of variation in the density of L-type Ca(2+) channels believed to underlie plateau formation in these cells with the added benefit of spreading plateau onset over a wider voltage range, as is observed experimentally.

Parsimonious design principles for motor unit models.

Motor units are known to display type-specific differences in passive and active electrical properties, and attempts to predict motor unit type based on the measurement of membrane properties have been rather successful. Quantitative models of motoneurons have also grown in complexity and their predictive power is predicated upon the accurate description of basic membrane properties. This paper presents results from a modeling study which sought to specify a small and simple set of "design rules" that motoneurons might obey during type-specific differentiation.

Synaptic amplification in motoneurons: computational and mechanistic implications.

Motoneurons are known to possess the latent ability to amplify their inputs in a voltage-dependent manner. Additionally, this synaptic amplification is known to be under neuromodulatory control. This paper presents results from a computer modeling study for one possible mechanism, termed electrotonic compression, which could underlie this behavior.