UNLABELLED: Cyanobacteria are ubiquitous aquatic organisms with a remarkable evolutionary history reaching as far as 1.9 Ga. They play a vital role in ecosystems yet also raise concerns due to their association with harmful algal blooms. Understanding the historical patterns and drivers behind these blooms is crucial for effective ecosystem management. Lake-sediment cores are valuable natural environmental archives, recording the histories of such blooms. Among others, phycocyanin, a pigment specific to cyanobacteria, emerges as a promising biomarker for reconstructing past cyanobacterial bloom events. However, due to the physicochemical properties of phycocyanin, there is no validated method available to extract and measure this pigment from complex sediment matrix. This study explores the applicability of hyperspectral imaging (HSI), a non-destructive technique, as a novel approach for high resolution in-situ detection and quantification of phycocyanin in lake sediments. Our experiments show that phycocyanin can be detected by HSI with an absorption trough at 620 nm (relative absorption band depth, RABD620). We established a semi-quantitative calibration of the spectral index RABD620 by conducting spiking experiments with phycocyanin standard (known phycocyanin mass) on organic-rich and mineral-rich sediments of varying water contents. We also assessed potential interference from chlorophyll a, another photosynthetic pigment, ensuring the reliability of hyperspectral phycocyanin measurements. Our findings demonstrate a significant correlation (R2 ranging from 0.37 to 0.997) between the RABD620 index and associated phycocyanin amounts in organic-rich and minerogenic sediments. This indicates the potential of the spectral index to directly measure in-situ biomarker concentrations on split sediment cores. Although confounding factors such as water and chlorophyll a content can influence the spectral signal, this method offers a rapid and non-destructive approach for studying historical cyanobacterial blooms in sedimentary records. This opens promising grounds for various applications, including ecosystem-health assessment and environmental change monitoring. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10933-024-00350-y.
- Keywords
- Algal blooms, Cyanobacteria, Environmental change, Paleolimnology, Pigments,
- Publication type
- Journal Article MeSH
The endorsement of conspiracy theories may be increased by subjectively perceived stress. Yet, it is not known whether this correlation is caused by the effects of the acute stress reaction on the brain or other psychological, social, or methodological factors. The effect of an experimentally induced acute stress reaction on conspiracy thinking was tested on a sample (n = 115) of students of medicine. Although the stress procedure caused a substantial increase in salivary cortisol, there was no significant effect on endorsing conspiracy theories or adopting conspiracy interpretations of novel information. The results confirmed no effect of the acute stress reaction on conspiracy thinking, suggesting it may be absent or weaker than expected. The study demonstrated the viability of psychophysiological experimental design in conspiracy research and may inspire further examination of the physiological mechanisms underlying susceptibility to conspiracy theories.
- Keywords
- Conspiracy theories, Maastricht Acute Stress Test, cortisol, stress,
- MeSH
- Adult MeSH
- Hydrocortisone analysis metabolism MeSH
- Humans MeSH
- Young Adult MeSH
- Stress, Psychological * psychology MeSH
- Saliva chemistry MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Hydrocortisone MeSH
Phytic acid is the main storage of phosphate in grains of staple crops. As phytic acid is hardly digestible for non-ruminants microbial phytases are used to supplement animal feed to enhance phosphate digestibility. A fungal phytase gene was introduced into barley with the aim of enhancing phosphate digestibility. Transgenic homozygous barley over-expressing fungal phytase phyA showed a 3.3fold increase in mature grain phytase activity. Field trials at two locations in the Czech Republic were conducted in a five-year experiment to test transgene stability and activity under field conditions. Increased phytase activity gradually decreased over the generations showing the most significant drop in the initial years of field trials. Molecular analysis revealed methylation in the coding sequence of the phyA transgene, suggesting transcription gene silencing. On the other hand, herbicide resistance used for selection of transgenic plants was functional over all generations. The feasibility of crossing the transgene into the feeding cultivar Azit was demonstrated with subsequent stabilization of hybrid progeny through androgenesis. Our results indicate that the Azit genetic background tended to reduce phytase activity in mature grains of hybrids. Grain-specific over-expression of fungal phytase driven by an amylase promoter improved phosphate levels during germination. Unfortunately, a malting experiment revealed that phytase over-expression did not significantly improve malting parameters. In fact, the higher nitrogen content in unmalted grain negatively affected the quality of the malt produced from them.
- Keywords
- Transgenic barley, androgenesis, field trials, hybridization, phytase,
- MeSH
- 6-Phytase * genetics metabolism MeSH
- Aspergillus niger * enzymology genetics MeSH
- Phosphates metabolism MeSH
- Fungal Proteins * genetics metabolism MeSH
- Plants, Genetically Modified * genetics metabolism MeSH
- Hordeum * genetics enzymology metabolism MeSH
- Phytic Acid metabolism MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- 6-Phytase * MeSH
- Phosphates MeSH
- Fungal Proteins * MeSH
- Phytic Acid MeSH
Inbred mouse strains provide phenotypic homogeneity between individual mice. However, stochastic morphogenetic events combined with epigenetic changes due to exposure to environmental factors and ontogenic experience result in variability among mice with virtually identical genotypes, reducing the reproducibility of experimental mouse models. Here we used microscopic and cytometric techniques to identify individual patterns in gut-associated lymphoid tissue (GALT) that are induced by exposure to microbiota. By comparing germ-free (GF), conventional (CV) and gnotobiotic mice colonized with a defined minimal mouse microbiota (oMM12) MHC II-EGFP knock-in mice we quantified antigen-presenting cells (APCs) in the lamina propria, cryptopatches (CP), isolated lymphoid follicles (ILFs), Peyer's patches (PPs) and specific sections of the mesenteric lymphoid complex. We found that GF mice had a significantly larger outer intestinal surface area compared to CV and oMM12-colonized mice, which partially compensated for their lower density of the villi in the distal ileum. GF mice also contained fewer APCs than oMM12 mice in the Iamina propria of the villi and had a significantly smaller volume of the solitary intestinal lymphoid tissue (SILT). In both GF and oMM12 mice, PP follicles were significantly smaller compared to CV mice, although number was similar. Concomitantly, the number of pDCs in PPs was significantly lower in GF mice than in CV mice. Moreover, the cecal patch was dispersed into small units in GF mice whereas it was compact in CV mice. Taken together, we here provide further evidence that microbiota regulates SILT differentiation, the size and morphology of PPs, the cellular composition of mesenteric lymph nodes (MLNs) and the morphology of cecal patch. As such, microbiota directly affect not only the functional configuration of the immune system but also the differentiation of lymphoid structures. These findings highlight how standardized microbiota, such as oMM12, can promote reproducibility in animal studies by enabling microbiologically controlled experiments across laboratories.
- Keywords
- Germ-free and gnotobiotic models, Gut-associated lymphoid tissue (GALT), Lymphoid tissue morphogenesis, MHCII-EGFP knock-in mice, Microbiota-induced immunity, Phenotypic plasticity,
- MeSH
- Antigen-Presenting Cells immunology MeSH
- Germ-Free Life MeSH
- Lymphoid Tissue * immunology cytology microbiology MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Peyer's Patches immunology cytology MeSH
- Gastrointestinal Microbiome * immunology MeSH
- Intestinal Mucosa immunology microbiology cytology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Chenopodium ficifolium is a close diploid relative of the tetraploid crop Chenopodium quinoa. Owing to its reproducible germination and seedling development, it becomes a promising model for studying floral induction, providing a basis for the comparison with C. quinoa. Two C. ficifolium genotypes differ in photoperiodic requirement: C. ficifolium 283 accelerates flowering under long days, whereas C. ficifolium 459 flowers earlier under short days. This study conducted a comprehensive transcriptomic and hormonomic analysis of floral induction in the long-day C. ficifolium 283 and compared the findings to previous experiments with the short-day C. ficifolium. Phytohormone concentrations and gene expression profiles during floral induction were largely similar between the two genotypes. However, a subset of genes exhibited contrasting expression patterns, aligning with the genotypes' differing photoperiodic requirements. These genes, predominantly homologs of flowering-related genes in Arabidopsis thaliana, were activated under long days in C. ficifolium 283 and under short days in C. ficifolium 459. Notably, the contrasting expression of the FLOWERING LOCUS T-LIKE 2-1 gene, which was previously shown to induce precocious flowering in A. thaliana, confirmed its role as a floral activator, despite its low expression levels.
- Keywords
- Flowering, genes with contrasting expression trends, long-day Chenopodium ficifolium, phytohormones, transcriptome,
- MeSH
- Chenopodium * genetics MeSH
- Photoperiod MeSH
- Genotype MeSH
- Flowers * genetics growth & development MeSH
- Gene Expression Regulation, Plant * MeSH
- Plant Growth Regulators metabolism MeSH
- Genes, Plant MeSH
- Plant Proteins genetics metabolism MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Plant Growth Regulators MeSH
- Plant Proteins MeSH
Super- and low-shedding phenomena have been observed in genetically homogeneous hosts infected by a single bacterial strain. To decipher the mechanisms underlying these phenotypes, we conducted an experiment with chicks infected with Salmonella Enteritidis in a non-sterile isolator, which prevents bacterial transmission between animals while allowing the development of the gut microbiota. We investigated the impact of four commensal bacteria called Mix4, inoculated at hatching, on chicken systemic immune response and intestinal microbiota composition and functions, before and after Salmonella infection. Our results revealed that these phenotypes were not linked to changes in cell invasion capacity of bacteria during infection. Mix4 inoculation had both short- and long-term effects on immune response and microbiota and promoted the low-shedder phenotype. Kinetic analysis revealed that Mix4 activated immune response from day 4, which modified the microbiota on day 6. This change promotes a more fermentative microbiota, using the aromatic compounds degradation pathway, which inhibited Salmonella colonization by day 11 and beyond. In contrast, control animals exhibited a delayed TNF-driven pro-inflammatory response and developed a microbiota using anaerobic respiration, which facilitates Salmonella colonization and growth. This strategy offers promising opportunities to strengthen the barrier effect against Salmonella and possibly other pathogens.
- Keywords
- Salmonella, carrier-state, chicken, excretion, immune response, microbiota, super-shedder, virulence,
- MeSH
- Bacteria * immunology classification genetics MeSH
- Chickens immunology microbiology MeSH
- Poultry Diseases * microbiology immunology prevention & control MeSH
- Salmonella enteritidis * immunology growth & development physiology MeSH
- Salmonella Infections, Animal * immunology microbiology prevention & control MeSH
- Gastrointestinal Microbiome * immunology MeSH
- Symbiosis MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
ABSTRACTBackground: European health care workers recently experienced serious challenges to their mental health. Following the extremely stressful experience of the COVID-19 pandemic, the war in Ukraine caused a humanitarian influx of refugees in need of social and healthcare. We aimed to explore: (1) how working with refugees has affected the mental well-being of health care workers in the context of the COVID-19 pandemic, and (2) the nature of health care workers' emotional strain related to the refugee situation and the war in Ukraine.Methods: We used a combination of quantitative regression analyses and qualitative content analysis to assess data collected by an online questionnaire in 2022. The study included 1121 health care workers from the Czech arm of the international HEROES Study.Results: Quantitative findings did not indicate that working with Ukrainian refugees was reliably associated with a greater occurrence of symptoms of depression, anxiety, distress, or burnout. Qualitative analysis revealed five categories of emotional strain: impacts on working conditions, emotional reactions to refugees and the war, comparisons with the COVID-19 pandemic, and coping strategies.Conclusions: This study highlights the resilience of health care workers but also points to the need for ongoing support to address the complex emotional challenges they face during health crises.
Although we did not find a significant association between working with refugees and mental health issues, health professionals encountered emotionally challenging situations.Emotionally challenging situations involved reactions to the war and refugees, worsening working conditions, and higher subjective strain than during the COVID-19 pandemic.When comparing health workers caring for with refugees and COVID-19 patients, we found differences in their mental health issues.
- Keywords
- COVID-19 pandemic, Migración, Migration, Russian-Ukrainian war, emotional strain, guerra ruso-ucraniana, malestar psicológico, pandemia de COVID-19, psychological distress,
- MeSH
- Adaptation, Psychological MeSH
- COVID-19 * psychology epidemiology MeSH
- Depression psychology epidemiology MeSH
- Adult MeSH
- Mental Health * MeSH
- Middle Aged MeSH
- Humans MeSH
- Pandemics MeSH
- Burnout, Professional * psychology epidemiology MeSH
- Surveys and Questionnaires MeSH
- Stress, Psychological * psychology MeSH
- SARS-CoV-2 MeSH
- Refugees * psychology MeSH
- Anxiety psychology epidemiology MeSH
- Health Personnel * psychology statistics & numerical data MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic epidemiology MeSH
- Ukraine ethnology MeSH
To avoid potentially noxious prey, predators need to discriminate between palatable and unpalatable prey species. Unpalatable prey often exhibits visual warning signals, which can consist of multiple components, such as color and pattern. Although the role of particular components of visual warning signals in predator discrimination learning has been intensively studied, the importance of different components for predator memory is considerably less understood. In this study, we tested adult wild-caught great tits (Parus major) to find out, which components of prey visual warning signals are important when the birds learn to discriminate between palatable and unpalatable prey, and when they remember their experience over a longer time period. Birds were trained to discriminate between palatable and unpalatable artificial prey items that differed in both color and pattern. After 4 wk, the birds were retested in 3 groups: the first group was presented with the same prey as in the training, the second group was tested with the two prey types differing only in color, and the third group could use only the pattern as a discrimination trait. The results suggest that the birds remember their experience with unpalatable prey even after the period of 4 wk. Although the color appears to be more important than the pattern, the combination of both signal components is more effective for prey recognition after several weeks than either the color or pattern alone.
- Keywords
- avian predators, color, discrimination learning, long-term memory, multicomponent signals, pattern, warning coloration,
- Publication type
- Journal Article MeSH
BACKGROUND: Targeted alpha therapy (TAT) is an effective option for cancer treatment. To maximize its efficacy and minimize side effects, carriers must deliver radionuclides to target tissues. Most of the nuclides used in TAT decay via the alpha cascade, producing several radioactive daughter nuclei with sufficient energy to escape from the original carrier. Therefore, studying these daughter atoms is crucial in the search for new carriers. Nanoparticles have potential as carriers due to their structure, which can prevent the escape of daughter atoms and reduce radiation exposure to non-target tissues. This work focuses on determining the released activity of 221Fr and 213Bi resulting from the decay of 225Ac labelled TiO2 nanoparticles. RESULTS: Labelling of TiO2 nanoparticles has shown high sorption rates of 225Ac and its progeny, 221Fr and 213Bi, with over 92 % of activities sorbed on the nanoparticle surface for all measured radionuclides. However, in the quasi-dynamic in vitro system, the released activity of 221Fr and 213Bi is strongly dependent on the nanoparticles concentration, ranging from 15 % for a concentration of 1 mg/mL to approximately 50 % for a nanoparticle concentration of 10 μg/mL in saline solution. The released activities of 213Bi were lower, with a maximum value of around 20 % for concentrations of 0.05, 0.025, and 0.01 mg/mL. The leakage of 225Ac and its progeny was tested in various biological matrices. Minimal released activity was measured in saline at around 10 % after 48 h, while the maximum activity was measured in blood serum and plasma at 20 %. The amount of 225Ac released into the media was minimal (<3 %). The in vitro results were confirmed in a healthy mouse model. The difference in %ID/g was clearly visible immediately after dissection and again after 6 h when 213Bi reached equilibrium with 225Ac. CONCLUSION: The study verified the potential release of 225Ac progeny from the labelled TiO2 nanoparticles. Experiments were performed to determine the dependence of released activity on nanoparticle concentration and the biological environment. The results demonstrated the high stability of the prepared 225Ac@TiO2 NPs and the potential release of progeny over time. In vivo studies confirmed our hypothesis. The data obtained suggest that the daughter atoms can escape from the original carrier and follow their own biological pathways in the organism.
- Keywords
- Actinium-225, Bismuth-213, Nanoparticles, Targeted alpha therapy, TiO(2),
- MeSH
- Actinium * chemistry MeSH
- Isotope Labeling MeSH
- Mice MeSH
- Nanoparticles * chemistry MeSH
- Radioisotopes * chemistry MeSH
- Titanium * chemistry MeSH
- Tissue Distribution MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Actinium-225 MeSH Browser
- Actinium * MeSH
- Radioisotopes * MeSH
- Titanium * MeSH
- titanium dioxide MeSH Browser
Phytocannabinoids, unique secondary metabolites of the plant Cannabis sativa L., are characterised by a wide spectrum of pharmacological activities and their use in medicine and food industry has increased exponentially in recent years. In this study, the bioavailability of 10 representatives of neutral cannabinoids and cannabinoid acids was evaluated using an in vitro model of Caco-2 cells, as well as in vivo using an inbred mouse model. In the context of a possible increase in bioavailability, the influence of matrix components associated with the 'cannabis synergy' phenomenon was also investigated. The analysis of cannabinoids and non-cannabinoid matrix components was performed using a sensitive and validated method based on ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC-HRMS/MS). As a proof of concept for testing formulation effects on bioavailability, the most abundant cannabinoid and its corresponding acid (CBD and CBDA) were encapsulated in nanomicelles and the effect of the formulation was tested both in vitro and in vivo. The experiments showed that cannabidiolic acid (CBDA) had a significantly better bioavailability compared to cannabidiol (CBD), especially in the in vivo model (CBDA concentrations in mouse plasma were approximately two orders of magnitude higher than those of CBD under the same dosing conditions). These results demonstrate the great potential of CBDA as a previously overlooked and therapeutically underutilized substance.
- Keywords
- Bioavailability, Caco-2, Cannabichromene (CBC), Cannabichromenic acid (CBCA), Cannabidiol (CBD), Cannabidiolic acid (CBDA), Cannabidivarin (CBDV), Cannabidivarinic acid (CBDVA), Cannabigerol (CBG), Cannabigerolic acid (CBGA), Cannabinol (CBN), Nanoformulation, Phytocannabinoids, UHPLC-HRMS/MS, Δ(9)-Tetrahydrocannabinolic acid A (Δ(9)-THCA-A),
- MeSH
- Biological Availability MeSH
- Caco-2 Cells MeSH
- Cannabis chemistry MeSH
- Cannabinoids * pharmacokinetics administration & dosage chemistry MeSH
- Humans MeSH
- Micelles MeSH
- Mice MeSH
- Nanoparticles chemistry MeSH
- Tandem Mass Spectrometry methods MeSH
- Chromatography, High Pressure Liquid methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- cannabidiolic acid MeSH Browser
- Cannabinoids * MeSH
- Micelles MeSH
