Palaeoclimate inferred from δ18O and palaeobotanical indicators in freshwater tufa of Lake Äntu Sinijärv, Estonia

We investigated a 3.75-m-long lacustrine sediment record from Lake Äntu Sinijärv, northern Estonia, which has a modeled basal age >12,800 cal yr BP. Our multi-proxy approach focused on the stable oxygen isotope composition (δ18O) of freshwater tufa. Our new palaeoclimate information for the Eastern Baltic region, based on high-resolution δ18O data (219 samples), is supported by pollen and plant macrofossil data. Radiocarbon dates were used to develop a core chronology and estimate sedimentation rates. Freshwater tufa precipitation started ca. 10,700 cal yr BP, ca. 2,000 years later than suggested by previous studies on the same lake. Younger Dryas cooling is documented clearly in Lake Äntu Sinijärv sediments by abrupt appearance of diagnostic pollen (Betula nana, Dryas octopetala), highest mineral matter content in sediments (up to 90 %) and low values of δ18O (less than −12 ‰). Globally recognized 9.3- and 8.2-ka cold events are weakly defined by negative shifts in δ18O values, to −11.3 and −11.7 ‰, respectively, and low concentrations of herb pollen and charcoal particles. The Holocene thermal maximum (HTM) is palaeobotanically well documented by the first appearance and establishment of nemoral thermophilous taxa and presence of water lilies requiring warm conditions. Isotope values show an increasing trend during the HTM, from −11.5 to −10.5 ‰. Relatively stable environmental conditions, represented by only a small-scale increase in δ18O (up to 1 ‰) and high pollen concentrations between 5,000 and 3,000 cal yr BP, were followed by a decrease in δ18O, reaching the most negative value (−12.7 ‰) recorded in the freshwater tufa ca. 900 cal yr BP

Anhydrite and gypsum in the Devonian and Permian evaporite lithofacies of Belarus : a review

Anhydrite is widespread in the Prypiać Trough in the form of beds and nodules in the Subsaliferous Terrigenous and Carbonate formations (Eifelian and Frasnian), the Lower Saliferous Formation (Frasnian), the Intersaliferous and Upper Saliferous formations (Famennian). It is also present in the Asselian and Sakmarian (Lower Permian) deposits of the trough. The anhydrite is grey, blue, pink and orange. It has massive and, more rarely, horizontal bedding, and a fine- and micro-crystalline structure. Gypsum extends widely across the Orša Depression, Žlobin and Latvijas Saddles and partly in the Belarusian Anteclise, where it lies within the Eifelian deposits. It is also found in the Frasnian strata of the North-Prypiać Shoulder. As a component of facial analogue of the Upper Saliferous Formation gypsum forms the Bryniou deposit in the west of the Prypiać Trough. This mineral is also observed in the Oversaliferous Formation (Famennian) and in the Asselian and Sakmarian strata of the trough. There are spar, saccharoidal, alabastrine and selenitic varieties of gypsum. A medium to coarse crystalline structure is typical. The gypsum is grey, pink, yellow or orange

Extracellular vesicles of human glial cells exert neuroprotective effects via brain miRNA modulation in a rat model of traumatic brain injury

Abstract Stem cell-based therapeutic approaches for neurological disorders are widely studied. Paracrine factors secreted by stem cells in vitro and delivered intranasally might allow bypassing the disadvantages associated with a surgical cell delivery procedure with likely immune rejection of a transplant. In this study, we investigated the therapeutic effect of the extracellular vesicles secreted by glial progenitor cells (GPC-EV) derived from human induced pluripotent stem cell in a traumatic brain injury model. Intranasal administration of GPC-EV to Wistar rats for 6 days improved sensorimotor functions assessed over a 14-day observation period. Beside, deep sequencing of microRNA transcriptome of GPC-EV was estimate, and was revealed 203 microRNA species that might be implicated in prevention of various brain pathologies. Modulation of microRNA pools might contribute to the observed decrease in the number of astrocytes that inhibit neurorecovery processes while enhancing neuroplasticity by decreasing phosphorylated Tau forms, preventing inflammation and apoptosis associated with secondary damage to brain tissue. The course of GPC-EV administration was promoted the increasing protein levels of NF-κB in studied areas of the rat brain, indicating NF-κB dependent mechanisms as a plausible route of neuroprotection within the damaged area. This investigation showed that GPC-EV may be representing a therapeutic approach in traumatic brain injury, though its translation into the clinic would require an additional research and development

The Study of Youth Resilience Across Cultures: Lessons from a Pilot Study of Measurement Development

Resilience researchers from diverse disciplines and cultural settings face formidable challenges in conceptualizing and developing standardized metrics of resilience that are representative of adolescent and young adult experiences across cultures. We discuss these issues using the case example of a pilot study involving researchers in 14 sites in 11 countries. The goal of the International Resilience Project was to develop a culturally and contextually relevant measure of youth resilience, the Child and Youth Resilience Measure (CYRM). Cultural sensitivity and an iterative research design introduced to the study a number of problems that future studies of resilience will need to address: ambiguity in the definition of positive outcomes; a lack of predictability of models across cultures; and measurement design challenges