Differential Effects of Reduced Cyclic Stretch and Perturbed Shear Stress Within the Arterial Wall and on Smooth Muscle Function

Background Cyclic circumferential stretch and shear stress act in concert and yet are capable of independently mediating arterial smooth muscle function, modulating the production of superoxide and stimulating arterial remodeling. Methods Porcine carotid arteries were perfused ex vivo for 72 h. Groups combining normal (5%) and reduced (1%) stretch with high shear (6 ± 3 dyn/cm2) and oscillatory shear (0.3 ± 3 dyn/cm2) stress were created, while maintaining a pulse pressure of 80 ± 10 mm Hg. Results Total superoxide production, fibronectin expression, and gelatinase activation were mediated by shear stress, but expression in the endothelial region was mediated by reduced cyclic stretch. By plotting intensity vs. radius, we saw that superoxide and gelatinase activity were in part mediated by stress distributions throughout the vascular wall, whereas fibronectin and p22-phox were much less or not at all. These findings, when coupled with our results from tissue reactive studies, suggest that the arterial remodeling process triggered in the endothelial region due to reduced stretch causes the most significant changes in arterial smooth muscle function. Conclusions We have found that the remodeling process triggered by reduced compliance in the endothelial region of large conduit arteries has a more profound detrimental effect to smooth muscle function than that brought on by perturbed shear stress. This work provides new insight by suggesting that although mechanical stimuli such as cyclic stretch and shear stress are known to augment similar markers of vascular remodeling, the location of their expression throughout the vascular wall differs greatly and this can have dramatic effects on vascular function. American Journal of Hypertension 2009; 22:1250-1257 © 2009 American Journal of Hypertension, Lt

Health effects in fish of long-term exposure to effluents from wastewater treatment works

The effects of simple mixtures of chemicals, with similar mechanisms of action, can be predicted using the concentration addition model (CA). The ability of this model to predict the estrogenic effects of more complex mixtures such as effluent discharges, however, has yet to be established. Effluents from 43 U.K. wastewater treatment works were analyzed for the presence of the principal estrogenic chemical contaminants, estradiol, estrone, ethinylestradiol, and nonylphenol. The measured concentrations were used to predict the estrogenic activity of each effluent, employing the model of CA, based on the relative potencies of the individual chemicals in an in vitro recombinant yeast estrogen screen (rYES) and a short-term (14-day) in vivo rainbow trout vitellogenin induction assay. Based on the measured concentrations of the four chemicals in the effluents and their relative potencies in each assay, the calculated in vitro and in vivo responses compared well and ranged between 3.5 and 87 ng/L of estradiol equivalents (E2 EQ) for the different effluents. In the rYES, however, the measured E2 EQ concentrations in the effluents ranged between 0.65 and 43 ng E2 EQ/L, and they varied against those predicted by the CA model. Deviations in the estimation of the estrogenic potency of the effluents by the CA model, compared with the measured responses in the rYES, are likely to have resulted from inaccuracies associated with the measurement of the chemicals in the extracts derived from the complex effluents. Such deviations could also result as a consequence of interactions between chemicals present in the extracts that disrupted the activation of the estrogen response elements in the rYES. E2 EQ concentrations derived from the vitellogenic response in fathead minnows exposed to a series of effluent dilutions were highly comparable with the E2 EQ concentrations derived from assessments of the estrogenic potency of these dilutions in the rYES. Together these data support the use of bioassays for determining the estrogenic potency of WwTW effluents, and they highlight the associated problems for modeling approaches that are reliant on measured concentrations of estrogenic chemicals

Towards Lightweight Data Integration using Multi-workflow Provenance and Data Observability

Modern large-scale scientific discovery requires multidisciplinary collaboration across diverse computing facilities, including High Performance Computing (HPC) machines and the Edge-to-Cloud continuum. Integrated data analysis plays a crucial role in scientific discovery, especially in the current AI era, by enabling Responsible AI development, FAIR, Reproducibility, and User Steering. However, the heterogeneous nature of science poses challenges such as dealing with multiple supporting tools, cross-facility environments, and efficient HPC execution. Building on data observability, adapter system design, and provenance, we propose MIDA: an approach for lightweight runtime Multi-workflow Integrated Data Analysis. MIDA defines data observability strategies and adaptability methods for various parallel systems and machine learning tools. With observability, it intercepts the dataflows in the background without requiring instrumentation while integrating domain, provenance, and telemetry data at runtime into a unified database ready for user steering queries. We conduct experiments showing end-to-end multi-workflow analysis integrating data from Dask and MLFlow in a real distributed deep learning use case for materials science that runs on multiple environments with up to 276 GPUs in parallel. We show near-zero overhead running up to 100,000 tasks on 1,680 CPU cores on the Summit supercomputer.Comment: 10 pages, 5 figures, 2 Listings, 42 references, Paper accepted at IEEE eScience'2

Characterization of distinct subpopulations of hepatic macrophages in HFD/obese mice.

The current dogma is that obesity-associated hepatic inflammation is due to increased Kupffer cell (KC) activation. However, recruited hepatic macrophages (RHMs) were recently shown to represent a sizable liver macrophage population in the context of obesity. Therefore, we assessed whether KCs and RHMs, or both, represent the major liver inflammatory cell type in obesity. We used a combination of in vivo macrophage tracking methodologies and adoptive transfer techniques in which KCs and RHMs are differentially labeled with fluorescent markers. With these approaches, the inflammatory phenotype of these distinct macrophage populations was determined under lean and obese conditions. In vivo macrophage tracking revealed an approximately sixfold higher number of RHMs in obese mice than in lean mice, whereas the number of KCs was comparable. In addition, RHMs comprised smaller size and immature, monocyte-derived cells compared with KCs. Furthermore, RHMs from obese mice were more inflamed and expressed higher levels of tumor necrosis factor-α and interleukin-6 than RHMs from lean mice. A comparison of the MCP-1/C-C chemokine receptor type 2 (CCR2) chemokine system between the two cell types showed that the ligand (MCP-1) is more highly expressed in KCs than in RHMs, whereas CCR2 expression is approximately fivefold greater in RHMs. We conclude that KCs can participate in obesity-induced inflammation by causing the recruitment of RHMs, which are distinct from KCs and are not precursors to KCs. These RHMs then enhance the severity of obesity-induced inflammation and hepatic insulin resistance

Soil methane sink capacity response to a long-term wildfire chronosequence in Northern Sweden

Boreal forests occupy nearly one fifth of the terrestrial land surface and are recognised as globally important regulators of carbon (C) cycling and greenhouse gas emissions. Carbon sequestration processes in these forests include assimilation of CO2 into biomass and subsequently into soil organic matter, and soil microbial oxidation of methane (CH4). In this study we explored how ecosystem retrogression, which drives vegetation change, regulates the important process of soil CH4 oxidation in boreal forests. We measured soil CH4 oxidation processes on a group of 30 forested islands in northern Sweden differing greatly in fire history, and collectively representing a retrogressive chronosequence, spanning 5000 years. Across these islands the build-up of soil organic matter was observed to increase with time since fire disturbance, with a significant correlation between greater humus depth and increased net soil CH4 oxidation rates. We suggest that this increase in net CH4 oxidation rates, in the absence of disturbance, results as deeper humus stores accumulate and provide niches for methanotrophs to thrive. By using this gradient we have discovered important regulatory controls on the stability of soil CH4 oxidation processes that could not have not been explored through shorter-term experiments. Our findings indicate that in the absence of human interventions such as fire suppression, and with increased wildfire frequency, the globally important boreal CH4 sink could be diminished

Quantification of finfish assemblages associated with mussel and seaweed farms in southwest UK provides evidence of potential benefits to fisheries

This is the final version. Available on open access from Inter-Research Science Publisher via the DOI in this recordLow trophic aquaculture, including shellfish and seaweed farming, offers a potentially sustainable food source and may provide additional environmental benefits, including the creation of new feeding, breeding and nursery areas for fish of commercial and ecological importance. However, quantitative assessments of fish assemblages associated with aquaculture sites are lacking. We used pelagic baited remote underwater videos (BRUVs) and hook and line catches to survey summer fish assemblages at 2 integrated blue mussel Mytilus edulis and kelp (predominantly Saccharina latissima) farms in southwest UK. We recorded at least 11 finfish species across the surveys, including several of commercial importance, with farmed mussels and/or kelps supporting significantly higher levels of abundance and richness than reference areas outside farm infrastructure. Farmed kelp provided temporary habitat due to seasonal harvesting schedules, whereas farmed mussels provided greater habitat stability due to overlapping interannual growth cycles. Stomach content analysis of fish caught at the farms revealed that some low trophic level species had high proportions of amphipods in their stomachs, which also dominated epibiont assemblages at the farms. Higher trophic level fish stomachs contained several lower trophic level fish species, suggesting that farms provide new foraging grounds and support secondary and tertiary production. Although not identified to species level, juvenile fish were abundant at both farms, suggesting potential provisioning of nursery or breeding grounds; however, this needs further verification. Overall, this study provides evidence that shellfish and seaweed aquaculture can support and enhance populations of commercially and ecologically important fish species through habitat provisioning.Worshipful Company of FishmongersCentre for Environment, Fisheries and Aquaculture Science (Cefas)Marine Biological AssociationNatural Environment Research Council (NERC)University of ExeterUKR

Differential effects of reduced cyclic stretch and perturbed shear stress within the arterial wall and on smooth muscle function

Cyclic circumferential stretch and shear stress act in concert and yet are capable of independently mediating arterial smooth muscle function, modulating the production of superoxide and stimulating arterial remodeling

An Assessment of the Model of Concentration Addition for Predicting the Estrogenic Activity of Chemical Mixtures in Wastewater Treatment Works Effluents

The effects of simple mixtures of chemicals, with similar mechanisms of action, can be predicted using the concentration addition model (CA). The ability of this model to predict the estrogenic effects of more complex mixtures such as effluent discharges, however, has yet to be established. Effluents from 43 U.K. wastewater treatment works were analyzed for the presence of the principal estrogenic chemical contaminants, estradiol, estrone, ethinylestradiol, and nonylphenol. The measured concentrations were used to predict the estrogenic activity of each effluent, employing the model of CA, based on the relative potencies of the individual chemicals in an in vitro recombinant yeast estrogen screen (rYES) and a short-term (14-day) in vivo rainbow trout vitellogenin induction assay. Based on the measured concentrations of the four chemicals in the effluents and their relative potencies in each assay, the calculated in vitro and in vivo responses compared well and ranged between 3.5 and 87 ng/L of estradiol equivalents (E2 EQ) for the different effluents. In the rYES, however, the measured E2 EQ concentrations in the effluents ranged between 0.65 and 43 ng E2 EQ/L, and they varied against those predicted by the CA model. Deviations in the estimation of the estrogenic potency of the effluents by the CA model, compared with the measured responses in the rYES, are likely to have resulted from inaccuracies associated with the measurement of the chemicals in the extracts derived from the complex effluents. Such deviations could also result as a consequence of interactions between chemicals present in the extracts that disrupted the activation of the estrogen response elements in the rYES. E2 EQ concentrations derived from the vitellogenic response in fathead minnows exposed to a series of effluent dilutions were highly comparable with the E2 EQ concentrations derived from assessments of the estrogenic potency of these dilutions in the rYES. Together these data support the use of bioassays for determining the estrogenic potency of WwTW effluents, and they highlight the associated problems for modeling approaches that are reliant on measured concentrations of estrogenic chemicals

Quadriceps foam rolling and rolling massage increases hip flexion and extension passive range-of-motion

Increases in joint range-of-motion may be beneficial for improving performance and reducing injury risk. This study investigated the effects of different self-massage volumes and modalities on passive hip range-of-motion. Twenty-five recreationally resistance-trained men performed four experimental protocols using a counterbalanced, randomized, and within-subjects design; foam rolling (FR) or roller massage (RM) for 60 or 120-s. Passive hip flexion and extension range-of-motion were measured in a counterbalanced and randomized order via manual goniometry before self-massage (baseline) and immediately, 10-, 20-, and 30-min following each self-massage intervention. Following FR or RM of quadriceps, there was an increase in hip flexion range-of-motion at Post-0 (FR: Δ = 19.28°; RM: Δ = 14.96°), Post-10 (FR: Δ = 13.03°; RM: Δ = 10.40°), and Post-20 (FR: Δ = 6.00°; RM: Δ = 4.64°) for all protocols, but these did not exceed the minimum detectable change at Post-10 for RM60 and RM120, and Post-20 for FR60, FR120, RM60, and RM120. Similarly, hip extension range-of-motion increased at Post-0 (FR: Δ = 8.56°; RM: Δ = 6.56°), Post-10 (FR: Δ = 4.64°; RM: Δ = 3.92°), and Post-20 (FR: Δ = 2.80°; RM: Δ = 1.92°), but did not exceed the minimum detectable change at Post-10 for FR60, RM60, and RM120, and Post-20 for FR60, FR120, RM60, and RM120. In conclusion, both FR and RM increased hip range-of-motion but larger volumes (120- vs. 60-second) and FR produced the greatest increases. These findings have implications for self-massage prescription and implementation, in both rehabilitation and athletic populations