Buchsahin0050

Z Iurium Wiki

The resuspension dynamics of microphytobenthos (MPB) and sediment fluxes were investigated in a disturbed coastal environment by employing an in situ mooring system. We aimed to identify the interrelationship between microalgal biomass and sediment particles in aspect of their (de)coupling mechanism in a tidal channel system. In specific, the Chl-a (as a proxy of MPB biomass) and the suspended sediment concentration (SSC) were simultaneously measured under natural tidal conditions at different time scales, encompassing daily to fortnightly variations. Looking for the sediment dynamics, the SSC showed a strong positive correlation (p  less then  0.001) with the Reynolds stress; however, this relationship was not observed for benthic Chl-a. This could be due to more dynamic characteristics of the smaller biological cells, i.e., the decoupled benthic Chl-a from the sediment particles might randomly distribute in the turbid water column above the tidal channel. Notably, the iteration between MPB coupling (prevailing in spring) and segregation (prevailing in neap) with the sediment particles across the flood and ebb tidal cycles was evident during the study period. Meantime, the onshore flux of suspended sediment was almost balanced by its offshore flux, but that of Chl-a appeared to be unbalanced due to an excessive onshore transport. Altogether, the study area seems to experience a time lag in resuspension between MPB and sediment, followed by biological trapping in the tidal channel system, which would support a productive shallow water environment. The present study is the first to address the tidal resuspension of benthic microalgae in relation to sediment dynamics in a disturbed coastal environment of the Yellow Sea. High concentrations of microplastics have been found in sea ice but the mechanisms by which they get captured into the ice and which role ice algae might play in this process remain unknown. Similarly, we do not know how the presence of microplastics might impact the colonization of sea ice by ice algae. To estimate the ecological impact of microplastics for Polar ecosystems, it is essential to understand their behaviour during ice formation and possible interactions with organisms inhabiting sea ice. In this study we tested the interaction between the ice algae Fragillariopsis cylindrus and microplastic beads with and without sea ice present and, in a third experiment, during the process of ice formation. With sea ice present, we found significantly less algae cells in the ice when incubated together with microplastics compared to the incubation without microplastics. However, during ice formation, the presence of microplastics did not impact the colonisation of the ice by F. cylindrus cells. Further, we observed a strong correlation between salinity and the relative amount of beads in the water and ice. With increasing salinity of the water, the relative amount of beads in the water decreased significantly. At the same time, the relative amount of beads in the ice increased significantly with increasing ice salinity. Both processes were not influenced by the presence of F. cylindrus. Also, we found indications that the presence of algae can affect the amount of microplastic beads sticking to the container walls. This could indicate that EPS produced by ice algae plays a significant role in surface binding properties of microplastics. Overall, our results highlight that the interactions between algae and microplastics have an influence on the uptake of microplastics into sea ice with possible implications for the sea ice food web. selleck compound BACKGROUND Recently, the impact of fine particulate matter pollution on cardiovascular system is drawing considerable concern worldwide. The association between ambient fine particulate and the cardiac arrhythmias is not clear now. OBJECTIVE To study associations of ambient fine particulate with incidence of arrhythmias in outpatients. METHODS Data was collected from the remote electrocardiogram (ECG) system covering 282 community hospitals in Shanghai from June 24th, 2014 to June 23rd, 2016. ECG was performed for patients admitted to above hospitals with complaining of chest discomfort or palpitation, or for regular check-ups. Air quality data during this time period was obtained from China National Environment Monitoring Center. A generalized additive quasi-Poisson model was established to examine the associations between PM2.5 and cardiac arrhythmias. RESULTS Cardiac arrhythmias were detected in 202,661 out of 1,016,579 outpatients (19.9%) and fine particulate matter ranged from 6 to 219 μg/m3 during this risk of arrhythmias in outpatients visiting Shanghai community hospitals, with an immediate or lag effect. The arrhythmogenic effect varies among different types of cardiac arrhythmias. A number of fatty acids have been found in porcine oocytes and early embryos. Recent studies have indicated the importance of fatty acids in the development of pre-implantation porcine embryos, whether derived from in vivo or somatic cell nuclear transfer. However, the effects of fatty acids on porcine embryos produced by in vitro fertilization (IVF) remain poorly defined. This study aimed to investigate the patterns of gene expression and functions of fatty acids in pre-implantation IVF porcine embryos at different stages using transcriptome sequencing. We found that, in IVF porcine embryos, genes related to fatty acid metabolism were positively expressed during early embryonic development. Additionally, the expression of genes related to lipid metabolism changed dramatically during the maternal-to-zygotic transition (MZT), and the genes associated with lipid metabolism were correlated with zygotic genome activation in porcine IVF embryos, suggesting that fatty acid metabolism plays an important role in MZT. In summary, fatty acid metabolism may be an indicator of MZT in porcine IVF embryos, which presents new considerations for exploring the regulatory mechanisms of this process. To interact and penetrate the egg, the spermatozoon must undergo a maturation step called the acrosome reaction (AR) in close proximity to the egg. This process can take place only after a series of biochemical changes to the sperm occur in the female reproductive tract, collectively called capacitation. Spermatozoa can undergo spontaneous-acrosome reaction (sAR) before reaching the vicinity of the egg, preventing successful fertilization. Several mechanisms were shown to protect spermatozoa from undergoing sAR. Here we describe the involvement of the actin cross-linker, Ezrin in the mechanism that protects spermatozoa from sAR. Inhibition of Ezrin stimulates sAR and inhibits actin polymerization. Ezrin is highly phosphorylated/activated during the first hour of the capacitation process, and its phosphorylation rate is subsequently decreased. Ezrin phosphorylation depends on protein kinase A (PKA) and calmodulin kinase II (CaMKII) activities, and to some extent on phosphatidyl-inositol-4-kinase (PI4K) activity.

Autoři článku: Buchsahin0050 (Lanier Randolph)