Allelopathic and bloom-forming picocyanobacteria in a changing world

Picocyanobacteria are extremely important organisms in the world’s oceans and freshwater ecosystems. They play an essential role in primary production and their domination in phytoplankton biomass is common in both oligotrophic and eutrophic waters. Their role is expected to become even more relevant with the effect of climate change. However, this group of photoautotrophic organisms still remains insufficiently recognized. Only a few works have focused in detail on the occurrence of massive blooms of picocyanobacteria, their toxicity and allelopathic activity. Filling the gap in our knowledge about the mechanisms involved in the proliferation of these organisms could provide a better understanding of aquatic environments. In this review, we gathered and described recent information about allelopathic activity of picocyanobacteria and occurrence of their massive blooms in many aquatic ecosystems. We also examined the relationships between climate change and representative picocyanobacterial genera from freshwater, brackish and marine ecosystems. This work emphasizes the importance of studying the smallest picoplanktonic fractions of cyanobacteria. © 2018 MDPI. All Rights reserved.Acknowledgments: We thank Sabina Jodłowska for execution photographic documentations of Synechococcus sp. strains on electron microscope. This study was supported by BMN grants, Poland, No. 538-G245-B568-17

Ecophysiological characteristics of red, green, and brown strains of the Baltic picocyanobacterium <i>Synechococcus</i> sp. – a laboratory study

The contribution of picocyanobacteria (PCY) to summer phytoplankton blooms, accompanied by an ecological crisis is a new phenomenon in Europe. This issue requires careful investigation. The present study examined the response of Synechococcus sp. physiology to different environmental conditions. Three strains of Synechococcus sp. (red BA-120, green BA-124, and brown BA-132) were cultivated in a laboratory under previously determined environmental conditions. These conditions were as follows: temperature (T) from 10 by 5 to 25&thinsp;°C, salinity from 3 by 5 to 18 PSU, and photosynthetically active radiation (PAR) from 10 by 90 to 280&thinsp;µmol&thinsp;photons&thinsp;m−2&thinsp;s−1, which gave 64 combinations of synthetic, though realistic, environmental scenarios. Scenarios reflecting all possible combinations were applied in the laboratory experiments. Results pointed to differences in final numbers of cells among strains. However, there was also a similar tendency for BA-124 and BA-132, which demonstrated the highest concentrations of PCY cells at elevated T and PAR. This was also the case for BA-120 but only to a certain degree as the number of cells started to decrease above 190&thinsp;µmol&thinsp;photons&thinsp;m−2&thinsp;s−1&thinsp;PAR. Pigmentation, chlorophyll a (Chl a), fluorescence, and rate of photosynthesis presented both similarities and differences among strains. In this context, more consistent features were observed between brown and red strains when compared to the green. In this paper, the ecophysiological responses of PCY are defined.</p

Experimental evaluation of vibrotactile training mappings for dual-joystick directional guidance

Two joystick-based teleoperation is a common method for controlling a remote machine or a robot. Their use could be counter-intuitive and could require a heavy mental workload. The goal of this paper is to investigate whether vibrotactile prompts could be used to trigger dual-joystick responses quickly and intuitively, so to possibly employ them for training. In particular, we investigate the effects of: (1) stimuli delivered either on the palm or on the back of the hand, (2) with attractive and repulsive mappings, (3) with single and sequential stimuli. We find that 38 participants responded quicker and more accurately when stimuli were delivered on the back of the hand, preferred to move towards the vibration. Sequential stimuli led to intermediate responses in terms of speed and accuracy

Three DNA Polymorphisms Previously Identified as Markers for Handgrip Strength Are Associated With Strength in Weightlifters and Muscle Fiber Hypertrophy.

Three DNA polymorphisms previously identified as markers for handgrip strength are associated with strength in weightlifters and muscle fiber hypertrophy. J Strength Cond Res XX(X): 000-000, 2019-Muscle strength is a highly heritable trait. So far, 196 single nucleotide polymorphisms (SNPs) associated with handgrip strength have been identified in 3 genome-wide association studies. The aim of our study was to validate the association of 35 SNPs with strength of elite Russian weightlifters and replicate the study in Polish weightlifters. Genotyping was performed using micro-array analysis or real-time polymerase chain reaction. We found that the rs12055409 G-allele near the MLN gene (p = 0.004), the rs4626333 G-allele near the ZNF608 gene (p = 0.0338), and the rs2273555 A-allele in the GBF1 gene (p = 0.0099) were associated with greater competition results (total lifts in snatch and clean and jerk adjusted for sex and weight) in 53 elite Russian weightlifters. In the replication study of 76 sub-elite Polish weightlifters, rs4626333 GG homozygotes demonstrated greater competition results (p = 0.0155) and relative muscle mass (p = 0.046), adjusted for sex, weight, and age, compared with carriers of the A-allele. In the following studies, we tested the hypotheses that these SNPs would be associated with skeletal muscle hypertrophy and handgrip strength. We found that the number of strength-associated alleles was positively associated with fast-twitch muscle fiber cross-sectional area in the independent cohort of 20 male power athletes (p = 0.021) and with handgrip strength in 87 physically active individuals (p = 0.015). In conclusion, by replicating previous findings in 4 independent studies, we demonstrate that the rs12055409 G-, rs4626333 G-, and rs2273555 A-alleles are associated with higher levels of strength, muscle mass, and muscle fiber size

Pitch Processing of Speech : Comparison of Psychoacoustic and Electrophysiological Data

The present study consisted of two experiments. The goal of the first experiment was to establish the just noticeable differences for the fundamental frequency of the vowel /u/ by using the 2AFC method. We obtained the threshold value for 27 cents. This value is larger than the motor reaction values which had been observed in previous experiments (e.g. 9 or 19 cents). The second experiment was intended to provide neurophysiological confirmation of the detection of shifts in a frequency, using event-related potentials (ERPs). We concentrated on the mismatch negativity (MMN) - the component elicited by the change in the pattern of stimuli. Its occurrence is correlated with the discrimination threshold. In our study, MMN was observed for changes greater than 27 cents - shifts of ±50 and 100 cents (effect size - Cohen’s d = 2.259). MMN did not appear for changes of ±10 and 20 cents. The results showed that the values for which motor responses can be observed are indeed lower than those for perceptual thresholds

Advances in combination therapies based on nanoparticles for efficacious cancer treatment: an analytical report

International audienceThe main objective of nanomedicine research is the development of nanoparticles as drug delivery systems or drugs per se to tackle diseases as cancer, which are a leading cause of death with developed nations. Targeted treatments against solid tumors generally lead to dramatic regressions, but, unfortunately, the responses are often short-lived due to resistant cancer cells. In addition, one of the major challenges of combination drug therapy (called ?cocktail?) is the crucial optimization of different drug parameters. This issue can be solved using combination nanotherapy. Nanoparticles developed in oncology based on combination nanotherapy are either (a) those designed to combat multidrug resistance or (b) those used to circumvent resistance to clinical cancer drugs. This review provides an overview of the different nanoparticles currently used in clinical treatments in oncology. We analyze in detail the development of combinatorial nanoparticles including dendrimers for dual drug delivery via two strategic approaches: (a) use of chemotherapeutics and chemosensitizers to combat multidrug resistance and (b) use of multiple cytotoxic drugs. Finally, in this review, we discuss the challenges, clinical outlook, and perspectives of the nanoparticle-based combination therapy in cancer

Allelopathic activity of the picocyanobacterium Synechococcus sp. on unicellular eukaryote planktonic microalgae

The production and release of allelopathic compounds is an important adaptation by which some species of cyanobacteria can achieve a competitive advantage over other primary producers. In the present study we tested the allelopathic activity of the picocyanobacterium Synechococcus sp. against the following coexisting unicellular eukaryote microalgae: Porphyridium purpureum, Stichococcus bacillaris, Prymnesium parvum and Nitzschia dissipata. With these species, we covered a wide range of taxonomic groups. We demonstrated that both the addition of Synechococcus sp. cell-free filtrate and coculture inhibited the growth, chlorophyll content and photosynthetic rate of P. purpureum and S. bacillaris. Conversely, P. parvum, a well-known mixotroph, was positively affected by both Synechococcus sp. treatments. In contrast, N. dissipata was not affected by either the picocyanobacterial filtrate or coculture. These results suggest that the negative allelopathic effect is related to a reduction in the photosynthetic rate, and that Synechococcus sp. allelopathy should be taken into account in the interactions between picocyanobacteria and eukaryote competitors coexisting in a planktonic system. © CSIRO.This study was supported by grants from BMN, Poland (number 538-G245-B568-17) and FCT Project UID/Multi/04423/2013

Cationic phosphorus dendrimer enhances photodynamic activity of rose Bengal against Basal cell Carcinoma cell lines

International audienceIn the last couple of decades, photodynamic therapy emerged as a useful tool in the treatment of basal cell carcinoma. However, it still meets limitations due to unfavorable properties of photosensitizers such as poor solubility or lack of selectivity. Dendrimers, polymers widely studied in biomedical field, may play a role as photosensitizer carriers and improve the efficacy of photodynamic treatment. Here, we describe the evaluation of an electrostatic complex of cationic phosphorus dendrimer and rose bengal in such aspects as singlet oxygen production, cellular uptake, and phototoxicity against three basal cell carcinoma cell lines. Rose bengal–cationic dendrimer complex in molar ratio 5:1 was compared to free rose bengal. Obtained results showed that the singlet oxygen production in aqueous medium was significantly higher for the complex than for free rose bengal. The cellular uptake of the complex was 2–7-fold higher compared to a free photosensitizer. Importantly, rose bengal, rose bengal–dendrimer complex, and dendrimer itself showed no dark toxicity against all three cell lines. Moreover, we observed that phototoxicity of the complex was remarkably enhanced presumably due to high cellular uptake. On the basis of the obtained results, we conclude that rose bengal–cationic dendrimer complex has a potential in photodynamic treatment of basal cell carcinoma

Fat Mass Index and dietary behaviours of the Polish Border Guard officers

Background. Due to specific requirements of service, Border Guard officers should be characterized by good health. Whereas there is lack of studies assessing nutritional status as well as dietary behaviours among Polish Border Guard officers. Objective. The aim of the study was to assess the impact of dietary behaviours of the Polish Border Guard officers on the Fat Mass Index. Material and methods. The study was carried out with participation of 250 Border Guard officers (187 men and 63 women), aged 37±6; years of service: 12±6. Nutritional status was determined with the electrical bioimpedance method using the TANITA MC-780 analyzer. According to the calculated Fat Mass Index value each person was qualified to one of the following groups: fat deficit, normal fat or excess fat. The Border Guard officers were asked to fill in the original questionnaire containing questions about nutritional behaviours in line with the recommendations of the Swiss Food Pyramid for Athletes in the basic version. Results. The excessive amount of fat in every third officer of the Border Guard and numerous irregularities in eating behaviours were found. According to the food pyramid the smallest scale of rational dietary choices (especially regularity of meals, fruit and vegetable consumption) was characteristic of officers with excess fat. In addition, officers from the excess fat group obtained, on average, a lower sum of points for compliance of nutritional behaviours with the recommendations of the Swiss Food Pyramid than those from other groups (49% vs. 59% and 56%, p=0.002). Conclusions. There is a need for nutritional education and further monitoring of both the nutritional status and dietary behaviours of Border Guard officers.Wprowadzenie. Z uwagi na specyfikę służby funkcjonariusze Straży Granicznej powinni charakteryzować się dobrym stanem zdrowia. Tymczasem brakuje badań na temat stanu odżywienia, jak również zachowań żywieniowych funkcjonariuszy Straży Granicznej w Polsce. Cel. Celem badań była ocena wpływu zachowań żywieniowych na Wskaźnik Tkanki Tłuszczowej funkcjonariuszy Straży Granicznej pełniących służbę w Polsce. Materiał i metody. Badania przeprowadzono w 2018 roku z udziałem 250 funkcjonariuszy Straży Granicznej (187 mężczyzn i 63 kobiet) w wieku 37±6 lat, pełniących służbę od 12±6 lat. Stan odżywienia oceniono metodą elektrycznej bioimpedancji z użyciem analizatora TANITA MC-780. Na podstawie obliczonej wartości Wskaźnika Tkanki Tłuszczowej każdą z osób zakwalifikowano do jednej z następujących grup: zbyt niska ilość tkanki tłuszczowej, prawidłowa ilość tkanka tłuszczowa lub nadmierna ilość tkanki tłuszczowej. Funkcjonariuszy poproszono o wypełnienie autorskiego kwestionariusza ankiety, zawierającego pytania na temat zachowań żywieniowych zgodnych z rekomendacjami szwajcarskiej piramidy żywienia dla sportowców w wersji podstawowej. Wyniki. Stwierdzono nadmierną ilość tkanki tłuszczowej u co trzeciego funkcjonariusza Straży Granicznej oraz liczne nieprawidłowości w zachowaniach żywieniowych tych osób. W odniesieniu do piramidy żywienia najmniejszą skalą racjonalnych wyborów żywieniowych (w szczególności dotyczącą regularności posiłków oraz spożycia owoców i warzyw) charakteryzowali się funkcjonariusze z nadmierną tkanką tłuszczową. Ponadto, funkcjonariusze z nadmierną ilością tkanki tłuszczowej uzyskali średnio niższą sumę punktów za zgodność zachowań żywieniowych z zaleceniami szwajcarskiej piramidy żywienia niż badani z pozostałych grup (49% vs 59% i 56%; p=0.002). Wnioski. Istnieje potrzeba edukacji żywieniowej oraz dalszego monitorowania zarówno stanu odżywienia jak i zachowań żywieniowych funkcjonariuszy Straży Granicznej

Can dendrimer based nanoparticles fight neurodegenerative diseases? Current situation versus other established approaches

International audienceFor several decades, the treatment of central nervous system (CNS) disorders such as, for instance, Alzheimer’s disease (AD), Huntington’s disease (HD), and Parkinson’s disease (PD) represented an important challenge due to the difficulty in delivering drug molecules and imaging agents to the brain. Two strategies have been developed aimed at achieving the efficient delivery of drugs to the brain: invasive (e.g., temporary osmotic Blood Brain Barrier (BBB) opening, direct local delivery of nanoparticles with encapsulated CNS drugs etc.) and noninvasive approaches. As a part of the noninvasive approach among systemic delivery of drug molecules across BBB using nanocarriers, dendrimers represent promising therapeutics agents per se or nanocarriers of CNS drugs and for gene therapies. This original review emphasizes and analyzes the use of dendrimers as promising systems in the treatment of AD and PD, ischemia/reperfusion injury, neuroinflammation including cerebral palsy, neurological injury after cardiac surgery and particularly after hypothermic circulatory arrest, and for retinal degeneration purposes