102 research outputs found
RAM function is dependent on Kapβ2-mediated nuclear entry
Eukaryotic gene expression is dependent on the modification of the first transcribed nucleotide of pre-mRNA by the addition of the 7-methylguanosine cap. The cap protects transcripts from exonucleases and recruits complexes which mediate transcription elongation, processing and translation initiation. The cap is synthesized by a series of reactions which link 7-methylguanosine to the first transcribed nucleotide via a 5′ to 5′ triphosphate bridge. In mammals, cap synthesis is catalysed by the sequential action of RNGTT (RNA guanylyltransferase and 5′-phosphatase) and RNMT (RNA guanine-7 methyltransferase), enzymes recruited to RNA pol II (polymerase II) during the early stages of transcription. We recently discovered that the mammalian cap methyltransferase is a heterodimer consisting of RNMT and the RNMT-activating subunit RAM (RNMT-activating mini-protein). RAM activates and stabilizes RNMT and thus is critical for cellular cap methylation and cell viability. In the present study we report that RNMT interacts with the N-terminal 45 amino acids of RAM, a domain necessary and sufficient for maximal RNMT activation. In contrast, smaller components of this RAM domain are sufficient to stabilize RNMT. RAM functions in the nucleus and we report that nuclear import of RAM is dependent on PY nuclear localization signals and Kapβ2 (karyopherin β2) nuclear transport protein
Mapping Flow-Obstructing Structures on Global Rivers
To help store water, facilitate navigation, generate energy, mitigate floods, and support industrial and agricultural production, people have built and continue to build obstructions to natural flow in rivers. However, due to the long and complex history of constructing and removing such obstructions, we lack a globally consistent record of their locations and types. Here, we used a consistent method to visually locate and classify obstructions on 2.1 million km of large rivers (width ≥30 m) globally. We based our mapping on Google Earth Engine’s high resolution images, which for many places have meter-scale resolution. The resulting Global River Obstruction Database (GROD) consists of 30,549 unique obstructions, covering six different obstruction types: dam, lock, low head dam, channel dam, and two types of partial dams. By classifying a subset of the obstructions multiple times, we are able to show high classification consistency (87% mean balanced accuracy) for the three types of obstructions that fully intersect rivers: dams, low head dams, and locks. The classification of the three types of partial obstructions are somewhat less consistent (61% mean balanced accuracy). Overall, by comparing GROD to similar datasets, we estimate GROD likely captured >90% of the obstructions on large rivers. We anticipate that GROD will be of wide interest to the hydrological modeling, aquatic ecology, geomorphology, and water resource management communities
A Picture of the Research Field of Doctoral Education from the Students’ Perspectives : Studies Using Questionnaires and Scales
Peer reviewe
Estrutura fitossociológica da floresta semidecídua de altitude do parque municipal da Grota Funda (Atibaia - estado de São Paulo)
Composição florística da floresta semidecídua de altitude do Parque Municipal da Grota Funda (Atibaia - Estado de São Paulo)
Region, Turkey
In this investigation, Hyla orientalis (eastern tree frog) was collected in different localities from Denizli province (Inner-west Anatolia Region - the eastern part of Aegean Region) Turkey, between 2008 and 2011 and examined for the first time for helminths. Also, this study contains first detailed SEM imaging attempt of the some amphibian helminths from Turkey. Of 17 Hyla orientalis 8 (47.05 %) were infected with one or more helminths. Hyla orientalis harbored one species of Monogenea 1 (Polystoma skrjabini), one species of Digenea (Pleurogenoides medians), three species of nematoda (Oswaldocruzia filiformis, Cosmocerca ornata and Abbreviata sp.), and one species of Acanthocephala (Acanthocephalus ranae). All helminths recorded first time for Hyla orientalis
EVALUATION OF ANTIOXIDANT, ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF
This study was designed to investigate the antioxidant, antimicrobial and cytotoxic activities of the several extracts obtained from the bulb and flowers of Muscari muscarimi which is endemic for the flora of Turkey. While beta-carotene/linoleic acid and DPPH methods were used for the determining antioxidant activity, Folin-Ciocalteu assay was used to detect the total phenolic contents in all extracts of M. muscarimi. The brine shrimp lethality test was used to screen for the possible cytotoxic activity of the extracts. Also, the ethanolic and methanolic extracts of M. muscari were tested against different microorganisms by means of disc diffusion method. In this case, Candid a albicans and Bacillus subtilis were found to be the most sensitive microorganisms with the zone of inhibition 19.2 mm and 17.1 mm, respectively. The results of the cytotoxic activity of the extracts revealed that the bulb extracts were more active than the flower extracts. The ethanolic bulb extract showed most noticeable activity with LC50 7.43 mu g/ml. Total phenolic contents of the extracts ranged from 18.35 to 38.13 mgGAEs/g extracts. Antioxidant and antimicrobial activities in all flower extracts were found to be higher than the bulb extracts. The results for higher antioxidant activity in flower extracts could be explained by presence of greater concentration of phenolics in the extracts. Results of the present study give strong scientific evidence for traditional uses of M. muscarimi
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