Chronic Hypoxia Induces Epigenetic Modifications in the Fetal Rat Heart

Heart disease remains the leading cause of death worldwide. As a result of studies done by Barker and associates, our awareness of the significance of stress during gestation as a risk factor for heart diseases has expanded. We now know that events in utero can significantly alter gene expression patterns in heart tissue leading to increase susceptibility to ischemia reperfusion injury in adulthood. The focus of this project was to elucidate the role of chronic hypoxia in the programming of the cardio-protective gene, Protein Kinase C epsilon (PKCε) in fetal rat heart. We used an animal, organ base, and cell culturing with the rat embryonic cell line H9c2 to determine the molecular events underpinning the heightened sensitivity to ischemia reperfusion injury of adult offspring exposed to chronic hypoxia in utero. We determined that chronic hypoxia directly represses PKCε expression through increase methylation of CpG dinucleotides for two SP1 binding sites located at proximal region of the PKCε promoter. Previous studies using reporter gene assays concluded the region encompassing both SP1 binding sites played a significant role in the activity of PKCε promoter. Chromatin immunoprecipitation (ChIP) assays further verified the functional significance of methylation for both Sp1 sites in reducing SP1 protein binding. In the presence of the DNA methylation inhibitor, 5-aza-2-deoxycytidine, binding of SP1 to PKCε promoter, promoter methylation, and PKCε protein and mRNA were restored to control levels. Connecting epigenetics to chronic hypoxia in utero led us to further investigate the underlining mechanism of hypoxia-induced methylation of PKCε promoter. The dominant pathway of cellular adaptation to hypoxic stress involves the stabilization of the Hypoxia-Inducible-Factor 1 alpha (HIF-1α). We found blockade of nuclear accumulation of HIF-1α did not restore PKCε mRNA to control values. Next, we found the ROS Scavengers N-acetylcysteine and 4-hydroxy Tempo protect against hypoxia-induced repression of PKCε gene activity, which linked oxidative stress to PKCε repression in fetal hearts. This project has demonstrated that chronic hypoxia directly regulates PKCε gene expression through ROS mediated epigenetic repression of PKCε promoter, which leads to long term programming of the fetal heart

Effectiveness of short-term heat acclimation on intermittent exercise in thermoneutral and hot environments

It is well-established that repetition of heat stress exposure has been shown to facilitate adaptations to the heat but these protocols have tended to be of a fixed work intensity, continuous exercise, long-term in duration (>7 days) and use hydration. Secondly, there is limited information on the potential use of heat acclimation as a training method for human performance in thermoneutral conditions. Therefore, the aims of this study were to investigate the effectiveness of short-term heat acclimation (STHA) for 5 days, using the controlled hyperthermia technique with dehydration, on intermittent exercise in thermoneutral and hot environments

Body mass estimates of phytosaurs (Archosauria: Parasuchidae) from the Petrified Forest Formation (Chinle Group: Revueltian : early-mid Norian) based on skull and limb bone measurements

Phytosaurs were the largest and most common semi-aquatic predators of the Late Triassic. Although their skulls are relatively common in the fossil record, articulated, or even associated skeletons are extremely rare, so it has always been difficult to gauge just how large (mass or length) an individual phytosaur may have been. Body mass in particular is an important physiological variable, often used for the scaling of organs, biomass determination, biomechanics, and locomotion. We take advantage of phytosaurs’ general similarity to extant crocodilians to attempt to reconstruct body mass and length based on measurements of the skulls and limbs of phytosaurs from the Upper Triassic Snyder and Canjilon quarries in north-central New Mexico. These quarries, in the Painted Desert Member of the Petrified Forest Formation (Revueltian: early-mid Norian) preserve catastrophic death assemblages that appear to well-represent discrete populations of phytosaurs. We also utilize a snout-vent measurement based on an articulated skeleton from the Canjilon quarry to compare the accuracy of different equations based on discrete limb elements. Body mass estimates for Snyder quarry phytosaurs range between 25 and 500 kg, with most specimens yielding estimates of approximately 200-350 kg. The Canjilon quarry sample encompasses fewer juveniles and more robust adults, including one individual that may have weighed as much as 535 kg. From equations based on nine extant crocodilian genera, these Revueltian phytosaurs appear to have approached 4.5 m total body length for a ~ 400 kg phytosaur. The prevalence of subadult to adult phytosaurs in both quarries based on body mass estimates corroborates qualitative estimates of the population structure based on skull sizes alone, thereby reinforcing the hypothesis that both quarries are catastrophic assemblages

Hybrid localized surface plasmon resonance and quartz crystal microbalance sensor for label free biosensing

We report on the design and fabrication of a hybrid sensor that integrates transmission-mode localized surface plasmonic resonance (LSPR) into a quartz crystal microbalance (QCM) for studying biochemical surface reactions. The coupling of LSPR nanostructures and a QCM allows optical spectra and QCM resonant frequency shifts to be recorded simultaneously and analyzed in real time for a given surface adsorption process. This integration simplifies the conventional combination of SPR and QCM and has the potential to be miniaturized for application in point-of-care (POC) diagnostics. The influence of antibody-antigen recognition effect on both the QCM and LSPR has been analyzed and discussed.`

Developing Performance Indicators for Nature-Based Solution Projects in Urban Areas: The Case of Trees in Revitalized Commercial Spaces

It is becoming increasingly important to audit nature-based solutions (NBS) projects to understand their utility in addressing urban sustainability goals. However, the ecological and social complexity of such projects makes it difficult to develop performance indicators. Focusing on specific case studies and specific natural elements could advance this area of research. Urban trees are a vital component of many NBS initiatives. Cities with ambitious tree-planting goals rely on urban revitalization to provide the conditions necessary to grow trees in highly urbanized areas, and in this way deploy NBS projects. We present a conceptual and methodological framework of case-specific performance indicators in the context of NBS projects. This framework addresses the type of parameters, measures, and data that could be considered when assessing small-scale, NBS-inspired, revitalization projects, taking the natural elements of these projects, in this case the trees, as the unit of assessment. Our framework integrates ecological, environmental, and social indicators of tree performance and was developed with the experience gained from on-going, multi-year research projects at two revitalization sites in Toronto, Canada, where street trees grew in engineered sub-surface habitats. The framework includes indicators related to: urban tree ecology; tree characteristics; soils; climate and atmosphere; built environment; tree planting, care, and maintenance; social characteristics of the urban space; and human decisions and governance. This study frames the need for interdisciplinarity and case specificity in the development of performance indicators for NBS projects

Magnetically Focused Proton Irradiation of Small Volume Radiosurgery Targets Using a Triplet of Quadrupole Magnets

Proton therapy is an advantageous choice for the irradiation of tumors in proximity of critical structures due to rapid dose fall off and high dose deposition at target compared to dose at the surface of the patient (ie, peak-to-entrance dose ratio (P/E)). However, with target fields below 1.0 cm, as often encountered in proton radiosurgery, multiple Coulomb scattering (MCS) broadens proton beams leading to diminished P/E advantages and reduced dose delivery efficiency (DDE). Magnetic focusing tends to counteract MCS and is a promising method to reduce these undesirable effects. The purpose of this research is to investigate the advantages of proton magnetic focusing with a triplet of quadrupole rare earth permanent magnets

DiOLISTIC Labeling of Neurons from Rodent and Non-human Primate Brain Slices

DiOLISTIC staining uses the gene gun to introduce fluorescent dyes, such as DiI, into neurons of brain slices (Gan et al., 2009; O'Brien and Lummis, 2007; Gan et al., 2000). Here we provide a detailed description of each step required together with exemplary images of good and bad outcomes that will help when setting up the technique. In our experience, a few steps proved critical for the successful application of DiOLISTICS. These considerations include the quality of the DiI-coated bullets, the extent of fixative exposure, and the concentration of detergent used in the incubation solutions. Tips and solutions for common problems are provided