Cooking and co-ingested polyphenols reduce in vitro methylmercury bioaccessibility from fish and may alter exposure in humans

Fish consumption is a major pathway for mercury exposure in humans. Current guidelines and risk assessments assume that 100% of methylmercury (MeHg) in fish is absorbed by the human body after ingestion. However, a growing body of literature suggests that this absorption rate may be overestimated. We used an in vitro digestion method to measure MeHg bioaccessibility in commercially-purchased fish, and investigated the effects of dietary practices on MeHg bioaccessibility. Cooking had the greatest effect, decreasing bioaccessibility on average to 12.5 ± 5.6%. Polyphenol-rich beverages also significantly reduced bioaccessibility to 22.7 ± 3.8% and 28.6 ± 13.9%, for green and black tea respectively. We confirmed the suspected role of polyphenols in tea as being a driver of MeHg's reduced bioaccessibility, and found that epicatechin, epigallocatechin gallate, rutin and cafeic acid could individually decrease MeHg bioaccessibility by up to 55%. When both cooking and polyphenol-rich beverage treatments were combined, only 1% of MeHg remained bioaccessible. These results call for in vivo validation, and suggest that dietary practices should be considered when setting consumer guidelines for MeHg. More realistic risk assessments could promote consumption of fish as a source of fatty acids, which can play a protective role against cardiovascular disease

Theoretical foundations of educational strategies used in e-learning environments for developing clinical reasoning in nursing students : a scoping review

E-learning environments expand opportunities for the use of educational strategies that may contribute to the development of clinical reasoning in nursing students. The purposes of this scoping review were the following: 1) to map the principles of cognitive companionship and the theoretical foundations underlying the design and implementation of educational strategies used in e-learning environments for developing clinical reasoning in nursing students; and 2) to identify the types of educational strategies used in e-learning environments for developing or assessing clinical reasoning in nursing students. A scoping review was conducted and was based on the Joanna Briggs Institute Framework. Bibliographical databases were searched for studies published between January 2010 to July 2017. Out of 1202 screened articles, 18 met eligibility criteria and were included in this review. Principles of cognitive companionship in e-learning environments provide key clues from a learning support perspective, such as integrated feedback, interactive group discussion, gaming, and questioning. However, theoretical foundations underlying educational strategies in e-learning environments are poorly documented and insufficiently associated with cognitive learning models. E-learning environments must have solid theoretical foundations to provide support for the development of CR in nursing students

Radium isotopes as submarine groundwater discharge (SGD) tracers: review and recommendations

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Garcia-Orellana, J., Rodellas, V., Tamborski, J., Diego-Feliu, M., van Beek, P., Weinstein, Y., Charette, M., Alorda-Kleinglass, A., Michael, H. A., Stieglitz, T., & Scholten, J. Radium isotopes as submarine groundwater discharge (SGD) tracers: review and recommendations. Earth-Science Reviews, 220, (2021): 103681, https://doi.org/10.1016/j.earscirev.2021.103681.Submarine groundwater discharge (SGD) is now recognized as an important process of the hydrological cycle worldwide and plays a major role as a conveyor of dissolved compounds to the ocean. Naturally occurring radium isotopes (223Ra, 224Ra, 226Ra and 228Ra) are widely employed geochemical tracers in marine environments. Whilst Ra isotopes were initially predominantly applied to study open ocean processes and fluxes across the continental margins, their most common application in the marine environment has undoubtedly become the identification and quantification of SGD. This review focuses on the application of Ra isotopes as tracers of SGD and associated inputs of water and solutes to the coastal ocean. In addition, we review i) the processes controlling Ra enrichment and depletion in coastal groundwater and seawater; ii) the systematics applied to estimate SGD using Ra isotopes and iii) we summarize additional applications of Ra isotopes in groundwater and marine studies. We also provide some considerations that will help refine SGD estimates and identify the critical knowledge gaps and research needs related to the current use of Ra isotopes as SGD tracers.J.Garcia-Orellana acknowledges the financial support of the Spanish Ministry of Science, Innovation and Universities, through the “Maria de Maeztu” programme for Units of Excellence (CEX2019-000940-M), the Generalitat de Catalunya (MERS; 2017 SGR – 1588) and the project OPAL (PID2019-110311RB-C21). V. Rodellas acknowledges financial support from the Beatriu de Pinós postdoctoral program of the Generalitat de Catalunya (2017-BP-00334 and 2019-BP-00241). M. Charette received support from the U.S. National Science Foundation (OCE-1736277). J. Scholten acknowledges the support through the SEAMOUNT BONUS project (art. 185), which is funded jointly by the EU and the Federal Ministry of Education and Research of Germany (BMBF, grant no. 03F0771B). P. van Beek and T. Stieglitz acknowledge support from the French ANR project MED-SGD (ANR-15-01CE-0004) and chair @RAction MED-LOC (ANR-14-ACHN-0007-01). A. Alorda-Kleinglass acknowledges financial support from ICTA “Unit of Excellence” (MinECo, MDM2015-0552-17-1) and PhD fellowship, BES-2017-080740. H. Michael acknowledges support from the U.S. National Science Foundation (EAR-1759879). M. Diego-Feliu acknowledges the financial support from the FI-2017 fellowships of the Generalitat de Catalunya (2017-FIB-00365). Fig. 3, Fig. 4, Fig. 7, Fig. 12 were designed by Gemma Solà (www.gemmasola.com)

Variability of protein level and phosphorylation status caused by biopsy protocol design in human skeletal muscle analyses

<p>Abstract</p> <p>Background</p> <p>Bergström needle biopsy is widely used to sample skeletal muscle in order to study cell signaling directly in human tissue. Consequences of the biopsy protocol design on muscle protein quantity and quality remain unclear. The aim of the present study was to assess the impact of different events surrounding biopsy protocol on the stability of the Western blot signal of eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), Akt, glycogen synthase kinase-3β (GSK-3β), muscle RING finger protein 1 (MuRF1) and p70 S6 kinase (p70 S6K). Six healthy subjects underwent four biopsies of the <it>vastus lateralis</it>, distributed into two distinct visits spaced by 48 hrs. At visit 1, a basal biopsy in the right leg was performed in the morning (R1) followed by a second in the left leg in the afternoon (AF). At visit 2, a second basal biopsy (R2) was collected from the right leg. Low intensity mobilization (3 × 20 right leg extensions) was performed and a final biopsy (Mob) was collected using the same incision site as R2.</p> <p>Results</p> <p>Akt and p70 S6K phosphorylation levels were increased by 83% when AF biopsy was compared to R1. Mob condition induced important phosphorylation of p70 S6K when compared to R2. Comparison of R1 and R2 biopsies revealed a relative stability of the signal for both total and phosphorylated proteins.</p> <p>Conclusions</p> <p>This study highlights the importance to standardize muscle biopsy protocols in order to minimize the method-induced variation when analyzing Western blot signals.</p

A graphical method for performance mapping of machines and milling tools

Optimal design of the machining setup in terms of installed machines, cutting tools and process parameters is of paramount importance for every manufacturing company. In most of the metal cutting companies, all choices related to machine eligibility and cutting parameters selection typically come from heuristic approaches and follow supplier indications or base on the skill of experienced machine operators. More advanced solutions, such as model-based and virtual approaches, are adopted less frequently mainly due to the lack of these techniques in grasping the underlying knowledge successfully. Aim of this work is to introduce a synthetic graphical representation of machining centers and cutting tools capabilities, to provide an accessible way to evaluate the feasibility and close-to-limit conditions of the cutting process. Taking inspiration from previous scientific works from the measurement engineering field, a set of 2D and 3D graphs are presented to map machine, tools and process capabilities, as well as their obtainable manufacturing performances and expectable tool life. This approach synthesizes the nominal data coming from different sources (catalogues, database, tool model geometries etc.) and the real cutting tools parameters used during the production phase. Some examples are provided to show the potential of this graphical evaluation in supporting process planning and decision-making and in formalizing the machining setup knowledge. Further developments are devoted to extend the method to other manufacturing processes, including hybrid processes. At the same time, an in-process data gathering software will be integrated for building a solid database that can be used by an autonomous multi-technological process selector, as well as by a pre-process condition advisor in an Industry 4.0 oriented way

Perspectives on Cognitive Phenotypes and Models of Vascular Disease

Clinical investigations have established that vascular-Associated medical conditions are significant risk factors for various kinds of dementia. And yet, we are unable to associate certain types of vascular deficiencies with specific cognitive impairments. The reasons for this are many, not the least of which are that most vascular disorders are multi-factorial and the development of vascular dementia in humans is often a multi-year or multi-decade progression. To better study vascular disease and its underlying causes, the National Heart, Lung, and Blood Institute of the National Institutes of Health has invested considerable resources in the development of animal models that recapitulate various aspects of human vascular disease. Many of these models, mainly in the mouse, are based on genetic mutations, frequently using single-gene mutations to examine the role of specific proteins in vascular function. These models could serve as useful tools for understanding the association of specific vascular signaling pathways with specific neurological and cognitive impairments related to dementia. To advance the state of the vascular dementia field and improve the information sharing between the vascular biology and neurobehavioral research communities, National Heart, Lung, and Blood Institute convened a workshop to bring in scientists from these knowledge domains to discuss the potential utility of establishing a comprehensive phenotypic cognitive assessment of a selected set of existing mouse models, representative of the spectrum of vascular disorders, with particular attention focused on age, sex, and rigor and reproducibility. The workshop highlighted the potential of associating well-characterized vascular disease models, with validated cognitive outcomes, that can be used to link specific vascular signaling pathways with specific cognitive and neurobehavioral deficits

Evolutionary Consequences of Altered Atmospheric Oxygen in Drosophila melanogaster

Twelve replicate populations of Drosophila melanogaster, all derived from a common ancestor, were independently evolved for 34+ generations in one of three treatment environments of varying PO2: hypoxia (5.0–10.1 kPa), normoxia (21.3 kPa), and hyperoxia (40.5 kPa). Several traits related to whole animal performance and metabolism were assayed at various stages via “common garden” and reciprocal transplant assays to directly compare evolved and acclimatory differences among treatments. Results clearly demonstrate the evolution of a greater tolerance to acute hypoxia in the hypoxia-evolved populations, consistent with adaptation to this environment. Greater hypoxia tolerance was associated with an increase in citrate synthase activity in fly homogenate when compared to normoxic (control) populations, suggesting an increase in mitochondrial volume density in these populations. In contrast, no direct evidence of increased performance of the hyperoxia-evolved populations was detected, although a significant decrease in the tolerance of these populations to acute hypoxia suggests a cost to adaptation to hyperoxia. Hyperoxia-evolved populations had lower productivity overall (i.e., across treatment environments) and there was no evidence that hypoxia or hyperoxia-evolved populations had greatest productivity or longevity in their respective treatment environments, suggesting that these assays failed to capture the components of fitness relevant to adaptation

Mapping metal (Hg, As, Se), lipid and protein levels within fish muscular system in two fish species (Striped Bass and Northern Pike)

Current guidelines tend to limitfish consumption based on mercury (Hg) or monomethylmercury(MeHg) content infishflesh, without considering the presence of antagonist chemical elements thatcould modulate Hg toxicity. However, it is difficult to assess the potential for antagonistic interactions ofthese elements since their covariation within muscle tissues is poorly known. Here we present thefirststudy simultaneously mapping multiple metal(oid)s (Hg, As and Se), lipids and proteins infishfillets inorder to assess the magnitude of intra-organ variability of metals and the potential for antagonisticinteractions. We mapped twofish species (Striped Bass and Northern Pike) with contrasting muscularstructure with respect to the presence of white, intermediate and red muscles. In individual Striped Bassmuscle tissues, metals varied on average by 2.2-fold. Methylmercury and selenium covaried strongly andwere related to protein content as assessed by % N; arsenic was inversely related to these elements andwas associated with the lipid fraction of the muscle. In Pike, no such relationship was found because thecontents in proteins and lipids were less variable. Arsenic speciation revealed that arsenobetaine andarsenolipids were the only As species in thosefish species, whereas the toxic inorganic As species (As3þ)was under the detection limit. Arsenobetaine was related to % N, whereas arsenolipids covaried with %lipids. Elemental associations found with muscle lipids and proteins could help explain changes inbioaccumulation patterns within and between individuals with potential implications onfish toxicology,biomonitoring and human consumption guidelines