Loading fluorescent Ca²⁺ indicators into living cells

Small-molecule fluorescent Ca2+ reporters are the most widely used tools in the field of Ca2+ signaling. The excellent spatial and temporal resolution afforded by fluorescent reporters has driven the understanding of Ca2+ as a messenger in many different cell types. In many situations, the cellular loading and monitoring of fluorescent Ca2+ indicators is quite trivial. However, there are numerous pitfalls that require consideration to ensure that optimal data are recorded. Fluorescent Ca2+ indicators have carboxylic acid groups for binding of Ca2+. Because these “free-acid” forms of the indicators are hydrophilic they cannot readily cross cell membranes and need to be introduced into cells using techniques such as microinjection, pinocytosis, or diffusion from a patch pipette. However, the most convenient and widely used method for loading indicators into cells is as hydrophobic compounds in which the carboxylic acid groups are esterified (commonly as acetoxymethyl [AM] or acetate esters). The ester versions of the indicators permeate the plasma membrane. The Ca2+-sensitive, free-acid form of the indicator is liberated following hydrolysis of the ester groups by intracellular esterases

Approaching Freshet beneath Landfast Ice in Kugmallit Bay on the Canadian Arctic Shelf: Evidence from Sensor and Ground Truth Data

The Mackenzie River is the largest river in the North American Arctic. Its huge freshwater and sediment load impacts the Canadian Beaufort Shelf, transporting large quantities of sediment and associated organic carbon into the Arctic Ocean. The majority of this sediment transport occurs during the freshet peak flow season (May to June). Mackenzie River-Arctic Ocean coupling has been widely studied during open water seasons, but has rarely been investigated in shallow water under landfast ice in Kugmallit Bay with field-based surveys, except for those using remote sensing. We observed and measured sedimentation rates (51 g m-2 d-1) and the concentrations of chlorophyll a (mean 2.2 ?g L-1) and suspended particulate matter (8.5 mg L-1) and determined the sediment characteristics during early spring, before the breakup of landfast ice in Kugmallit Bay. We then compared these results with comparable data collected from the same site the previous summer. Comparison of organic quality in seston and trapped material demonstrated substantial seasonal differences. The subtle changes in biological and oceanographic variables beneath landfast ice that we measured using sensors and field sampling techniques suggest the onset of a spring melt occurring hundreds of kilometres farther south in the Mackenzie Basin.Le fleuve Mackenzie est le plus grand fleuve de l’Arctique nord-américain. Son énorme bassin d’eau douce et sa masse de sédiments ont des effets sur la plateforme externe de la mer de Beaufort canadienne, transportant ainsi de grandes quantités de sédiments et de carbone organique associé dans l’océan Arctique. La plus grande partie du transport des sédiments se produit pendant la saison haute d’écoulement du courant d’eau douce dans la mer (de mai à juin). Même si le couplage du fleuve Mackenzie et de l’océan Arctique a fait l’objet d’études approfondies durant les saisons d’eau libre, il a rarement été étudié en eau peu profonde sous la banquise de la baie Kugmallit au moyen d’études sur le terrain, sauf dans le cas d’études faisant appel à la télédétection. Nous avons observé et mesuré les taux de sédimentation (51 g m-2 d-1) et les concentrations de chlorophylle a (moyenne de 2,2 ?g L-1) et de matière particulaire en suspension (8,5 mg L-1), puis déterminé les caractéristiques des sédiments au début du printemps, avant la rupture de la banquise dans la baie Kugmallit. Ensuite, nous avons comparé ces résultats à des données comparables recueillies au même emplacement l’été précédent. La comparaison de la qualité organique du seston et des matières emprisonnées faisait ressortir d’importantes différences saisonnières. Les changements subtils sur le plan des variables biologiques et océanographiques sous la banquise que nous avons mesurés à l’aide de capteurs et de techniques d’échantillonnage sur le terrain laissent entrevoir un début de fonte du printemps se produisant à des centaines de kilomètres plus au sud, dans le bassin du Mackenzie

The Physics of Galaxy Cluster Outskirts

As the largest virialized structures in the universe, galaxy clusters continue to grow and accrete matter from the cosmic web. Due to the low gas density in the outskirts of clusters, measurements are very challenging, requiring extremely sensitive telescopes across the entire electromagnetic spectrum. Observations using X-rays, the Sunyaev-Zeldovich effect, and weak lensing and galaxy distributions from the optical band, have over the last decade helped to unravel this exciting new frontier of cluster astrophysics, where the infall and virialization of matter takes place. Here, we review the current state of the art in our observational and theoretical understanding of cluster outskirts, and discuss future prospects for exploration using newly planned and proposed observatories.Comment: 56 pages. Review paper. Published in Space Science Review

Terrestrial pollution in the Pechora basin, north-eastern European Russia

The chemical composition of snow, terricolous lichens and top-soil along with abundance and diversity of lichen communities were assessed in the Pechora and Usa basins, North-Eastern European Russia. Transects were established through the principal industrial towns of Vorkuta, Inta and Usinsk to assess the spatial extent of acid or alkaline and metal deposition. A further eight sites were selected to assess local impacts of oil and gas operations. In the Usa basin decreases of nitrogen concentration in the lichen Cladonia stellaris and winter deposition of non-sea salt sulphate moving northward were attributed to long range transport of oxides of nitrogen and sulphur from lower latitudes. Increased ionic content and pH of snow, along with elevated nitrogen concentrations and modified cation ratios in lichens (Cladonia arbuscula and Flavocetraria cucullata) within 25-40 km of Vorkuta and Inta were attributed to local deposition of alkaline coal ash. Nitrate concentration in snow did not vary with proximity to perceived pollution sources. Trace metal composition of winter snowpack, snow-melt filter residues and top-soils indicated elevated concentrations of elements associated with alkaline combustion ash around coal mining operations in Vorkuta and Inta, adding significantly to the soil metal loading as a result of ash fallout. Around the petrochemical industry near Usinsk there was little evidence of trace metal deposition. Acid deposition was associated with pristine areas, whereas alkaline combustion ash near to emission sources more than compensated for the acidity due to S02 and NOx. There were limited perturbations in the chemical signals in lichens, top-soils and lichen diversity close to an oil and gas industrial complex on the Kolva river. Here, there were elevations of lead and nitrogen concentrations in lichen apices and in the apical : basal nitrogen ratio in Flavocetraria cucullata, with lower lichen diversity of epigeal and epiphytic lichens. Elevated concentrations of Ba and Ca were found in soil-ash, probably as a result of local emissions from construction activity and gas flaring, rather than from long-range transport. Virtually all other sites remained unmodified and reflected background concentrations.The ecological impacts of the measured pollution loads are discussed

Predictors and outcomes of recognition of intellectual disability for adults during hospital admissions : A retrospective data linkage study in NSW, Australia

Adults with intellectual disability have high health care needs. Despite frequent contact with health services, they often receive inadequate health care. One method to improve health care delivery is reasonable adjustments, that is, the adaptation of health care delivery such that barriers to participation are removed for the person with disability. A starting point for the provision of reasonable adjustments is recognition of intellectual disability during the health care contact. To determine rates and predictors of the recognition of intellectual disability during hospital admissions, and its impact on admission metrics, we examined a population of adults with intellectual disability identified from disability services datasets from New South Wales, Australia between 2005 and 2014. Recognition of intellectual disability was determined by the recording of an International Classification of Diseases 10th revision (ICD-10) diagnostic code for intellectual disability during a given hospital admission. We examined how recognition of intellectual disability related to length of hospital episodes. We found an overall low rate of recognition of intellectual disability (23.79%) across all hospital episodes, with the proportion of hospital episodes recognising intellectual disability decreasing from 2005–2015. Admissions for adults with complex health profiles (e.g., those with many comorbidities, those with Autism Spectrum Disorder, and those admitted for urgent treatment) were more likely to recognise intellectual disability, but admissions for adults with complexity in other domains (i.e., for those in custody, or those with drug and alcohol disorders) were less likely to recognise intellectual disability. Recognition of intellectual disability was associated with longer episodes of care, possibly indicating the greater provision of reasonable adjustments. To improve the recognition of intellectual disability for adults during health service contacts, we advocate for the implementation of targeted initiatives (such as a nationwide disability flag to be included in health service records) to improve the provision of reasonable adjustments

Terrestrial pollution in the Pechora basin, north-eastern European Russia

The chemical composition of snow, terricolous lichens and top-soil along with abundance and diversity of lichen communities were assessed in the Pechora and Usa basins, North-Eastern European Russia. Transects were established through the principal industrial towns of Vorkuta, Inta and Usinsk to assess the spatial extent of acid or alkaline and metal deposition. A further eight sites were selected to assess local impacts of oil and gas operations. In the Usa basin decreases of nitrogen concentration in the lichen Cladonia stellaris and winter deposition of non-sea salt sulphate moving northward were attributed to long range transport of oxides of nitrogen and sulphur from lower latitudes. Increased ionic content and pH of snow, along with elevated nitrogen concentrations and modified cation ratios in lichens (Cladonia arbuscula and Flavocetraria cucullata) within 25-40 km of Vorkuta and Inta were attributed to local deposition of alkaline coal ash. Nitrate concentration in snow did not vary with proximity to perceived pollution sources. Trace metal composition of winter snowpack, snow-melt filter residues and top-soils indicated elevated concentrations of elements associated with alkaline combustion ash around coal mining operations in Vorkuta and Inta, adding significantly to the soil metal loading as a result of ash fallout. Around the petrochemical industry near Usinsk there was little evidence of trace metal deposition. Acid deposition was associated with pristine areas, whereas alkaline combustion ash near to emission sources more than compensated for the acidity due to S02 and NOx. There were limited perturbations in the chemical signals in lichens, top-soils and lichen diversity close to an oil and gas industrial complex on the Kolva river. Here, there were elevations of lead and nitrogen concentrations in lichen apices and in the apical : basal nitrogen ratio in Flavocetraria cucullata, with lower lichen diversity of epigeal and epiphytic lichens. Elevated concentrations of Ba and Ca were found in soil-ash, probably as a result of local emissions from construction activity and gas flaring, rather than from long-range transport. Virtually all other sites remained unmodified and reflected background concentrations.The ecological impacts of the measured pollution loads are discussed

Do’s and don’ts of microplastic research: a comprehensive guide

Microplastics are environmental contaminants consisting of small plastics ≤ 5 mm. Concerns over the adverse effects of microplastics have led to a rapid growth in the available literature despite the lack of harmonized methods and materials. Therefore, the field is becoming increasingly daunting to new researchers. A state-of-theart guide was assembled following a comprehensive literature review of microplastics research with the intent of addressing contemporary challenges, prioritized based on a survey, and introducing best practices. The lack of standardized methods and reference materials, the lack of access to analytical equipment, and the difficulty in working with lower environmental concentrations in laboratory tests (e.g., toxicity assays) remain a great challenge. The present work addresses these issues across three main sections: definitions, sampling, and evaluation of adverse effects. Harmonized methods and greater collaboration were identified as opportunities in this rapidly evolving field. A review of available interlaboratory comparison tests was also conducted to support additional recommendations.Padrão J would like to acknowledge the funding by the Portuguese Foundation for Science and Technology (FCT), European Regional Development Fund (FEDER), Operational Program for Competitiveness Factors (COMPETE), and Portuguese Ministry of Science, Technology and Higher Education (MCTS): [UID/CTM/00264/2021]