Book review: behind the screen: content moderation in the shadows of social media by Sarah T. Roberts

In Behind the Screen: Content Moderation in the Shadows of Social Media, Sarah T. Roberts explores the work conditions and experiences of people employed in ‘commercial content moderation’, drawing on interviews with those tasked with detecting and removing harmful and upsetting online content. As the problems faced by CCM workers reveal the economic, social and political distortions of the digital age, this book will be of interest to social science researchers as well as anyone who is a user of social media, writes H. Guney Akgul

DIVERSITY OF MICROFUNGI ON FAGACEAE IN ULUDAG FORESTS

WOS: 000363091600042Forests ecosystems are sources of oxygen and wood products, also they prevent soil erosion, improve water and air quality, serve as homes for wildlife; and therefore, they preserve and increase biodiversity. Forests can host a diverse community of fungal species with various effects on their host trees. In this research, trees of Fagaceae family of Uludag forests of Bursa province were investigated between the years of 2002 and 2008. By microscopic examination we identified 38 microfungi species in 27 genera belongs to Ascomycota and 1 microfungus species in 1 genus belongs to Basidiomycota. The taxa belong to 15 families: Botryosphaeriaceae, Diaporthaceae, Diatrypaceae, Dothioraceae, Erysiphaceae, Gnomoniaceae, Incertae sedis, Melanconidaceae, Microstromataceae, Nectriaceae, Pseudovalsaceae, Rhytismataceae, Trichosphaeriaceae, Valsaceae and Xylariaceae. The distribution of species by trophic groups revealed a dominance of xylotrophic species. With this study, fungal diversity of Fagaceae family in Uludag forests was identified and included in the mycobiota of Turkey

Determination of cadmium accumulation capabilities of aquatic macrophytes Ceratophyllum demersum, Bacopa monnieri and Rotala rotundifolia

In the present study, cadmium (Cd) accumulation capabilities of aquatic macrophytes Ceratophyllum demersum, Bacopa monnieri and Rotala rotundifolia were determined after treating both individual and triple macrophytes. The macrophytes were treated with Cd at 0, 0.1, 1 and 10 mg/L concentrations in a controlled chamber for 12-days. Cadmium accumulations increased with increasing Cd concentrations in all macrophytes. Bioconcentration factor (BCF), which indicates the efficiency of the macrophyte to accumulate Cd, decreased with increased external Cd concentrations. When compared to single macrophyte applications, reductions were observed in Cd accumulation of the combined macrophyte treatments. The maximum Cd accumulation was recorded in R. rotundifolia followed by C. demersum and B. monnieri in both single and combined macrophyte applications. Consequently, the macrophytes in both applications proved highly effective in the accumulation of Cd. Thus, they may be used especially in the abatement and monitoring of Cd pollution

Macrocrystals of Colloidal Quantum Dots in Anthrancene: Exciton Trannsfer and Polarized Emission

Cataloged from PDF version of article.In this work, centimeter-scale macrocrystals of nonpolar colloidal quantum dots (QDs) incorporated into anthracene were grown for the first time. The exciton transfer from the anthracene host to acceptor QDs was systematically investigated, and anisotropic emission from the isotropic QDs in the anthracene macrocrystals was discovered. Results showed a decreasing photoluminescence lifetime of the donor anthracene, indicating a strengthening energy transfer with increasing QD concentration in the macrocrystals. With the anisotropy study, QDs inside the anthracene host acquired a polarization ratio of similar to 1.5 at 0 degrees collection angle, and this increases to similar to 2.5 at the collection angle of 60 degrees. A proof-of-concept application of these excitonic macrocrystals as tunable color converters on light-emitting diodes was also demonstrated

Study on determination of bioactive potentials of certain lichens

Lichens are symbiotic associations that are formed by fungi and algae or cyanobacteria. The number of lichen species investigated pharmaceutically is still very low at present. The present study aims to determine the antioxidant activities, antibacterial activities, DNA protective activities, and oxidative stress status of Bryoria fuscescens (Gyeln.) Brodo & D. Hawksw., Parmelina tiliacea (Hoffm.) Hale, and Umbilicaria decussata (Vill.) Zahlbr. Lichens were extracted with ethanol in the Soxhlet device. The DPPH method was used to determine antioxidant activities. DNA protective activity was determined using pBR322 supercoil DNA. Antibacterial activity was determined with dilution test on 5 different species of bacteria (Enterocossus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus). Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were defined with Rel Assay Diagnostics kits. It was observed that DPPH free radical scavenging activities in lichen ethanol extracts increased with increasing concentration. The highest antioxidant activity was observed in B. fuscescens and the lowest activity was determined in U. decussata. It was also determined that the ethanol extracts of all lichen samples had DNA-protective activity. The highest antibacterial activity was detected in B. fuscescens, while the lowest activity was detected in U. decussata. It was determined that B. fuscescens had the highest oxidative stress index and U. decussata had the lowest value. It appears that the ethanol extracts of the lichen samples utilized in the study could be used as an alternative and complementary resource in medical treatment

Fomitopsis pinicola in healthful dietary approach and their therapeutic potentials

Certain macrofungi species have been used for medical purposes and as nutrients since the old times. The present study aims to determine and compare total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI) values, and Fe, Zn, Cu, Pb, and Ni levels in Fomitopsis pinicola (Sw.) P. Karst samples gathered in Balıkesir province Kazdağı National Park and Yalova province Çınarcık Hasan Baba Woods in Turkey. TAS, TOS, and OSI values of mushroom samples were measured with Rel Assay kits. Mushroom heavy metal content was determined using an atomic absorption spectrophotometer and wet decomposition procedure. In the samples collected from Çınarcık district, OSI values were 0.99±0.03, while in the samples collected from Kazdağı National Park, OSI values were 0.13±0.01. Fe content in the samples collected from Çınarcık district were 265.9±70.5 ppm, while Fe content in the samples collected from Kazdağı National Park were 31.31±1.43 ppm. As a result, it is considered that the mushrooms could be used as antioxidant source. Furthermore, it could be argued that as a result of the increase in heavy metal levels, the production of oxidants increases in living organisms, which in turn increases the oxidative stress index

Omacetaxine may have a role in chronic myeloid leukaemia eradication through downregulation of Mcl-1 and induction of apoptosis in stem/progenitor cells

Chronic myeloid leukaemia (CML) is maintained by a rare population of tyrosine kinase inhibitor (TKI)-insensitive malignant stem cells. Our long-term aim is to find a BcrAbl-independent drug that can be combined with a TKI to improve overall disease response in chronic-phase CML. Omacetaxine mepesuccinate, a first in class cetaxine, has been evaluated by clinical trials in TKI-insensitive/resistant CML. Omacetaxine inhibits synthesis of anti-apoptotic proteins of the Bcl-2 family, including (myeloid cell leukaemia) Mcl-1, leading to cell death. Omacetaxine effectively induced apoptosis in primary CML stem cells (CD34<sup>+</sup>38<sup>lo</sup>) by downregulation of Mcl-1 protein. In contrast to our previous findings with TKIs, omacetaxine did not accumulate undivided cells <i>in vitro</i>. Furthermore, the functionality of surviving stem cells following omacetaxine exposure was significantly reduced in a dose-dependant manner, as determined by colony forming cell and the more stringent long-term culture initiating cell colony assays. This stem cell-directed activity was not limited to CML stem cells as both normal and non-CML CD34<sup>+</sup> cells were sensitive to inhibition. Thus, although omacetaxine is not leukaemia stem cell specific, its ability to induce apoptosis of leukaemic stem cells distinguishes it from TKIs and creates the potential for a curative strategy for persistent disease

Downregulation of Mcl-1 has anti-inflammatory pro-resolution effects and enhances bacterial clearance from the lung

Phagocytes not only coordinate acute inflammation and host defense at mucosal sites, but also contribute to tissue damage. Respiratory infection causes a globally significant disease burden and frequently progresses to acute respiratory distress syndrome, a devastating inflammatory condition characterized by neutrophil recruitment and accumulation of protein-rich edema fluid causing impaired lung function. We hypothesized that targeting the intracellular protein myeloid cell leukemia 1 (Mcl-1) by a cyclin-dependent kinase inhibitor (AT7519) or a flavone (wogonin) would accelerate neutrophil apoptosis and resolution of established inflammation, but without detriment to bacterial clearance. Mcl-1 loss induced human neutrophil apoptosis, but did not induce macrophage apoptosis nor impair phagocytosis of apoptotic neutrophils. Neutrophil-dominant inflammation was modelled in mice by either endotoxin or bacteria (Escherichia coli). Downregulating inflammatory cell Mcl-1 had anti-inflammatory, pro-resolution effects, shortening the resolution interval (R(i)) from 19 to 7 h and improved organ dysfunction with enhanced alveolar–capillary barrier integrity. Conversely, attenuating drug-induced Mcl-1 downregulation inhibited neutrophil apoptosis and delayed resolution of endotoxin-mediated lung inflammation. Importantly, manipulating lung inflammatory cell Mcl-1 also accelerated resolution of bacterial infection (R(i); 50 to 16 h) concurrent with enhanced bacterial clearance. Therefore, manipulating inflammatory cell Mcl-1 accelerates inflammation resolution without detriment to host defense against bacteria, and represents a target for treating infection-associated inflammation

Wogonin and related natural flavones are inhibitors of CDK9 that induce apoptosis in cancer cells by transcriptional suppression of Mcl-1

The wogonin-containing herb Scutellaria baicalensis has successfully been used for curing various diseases in traditional Chinese medicine. Wogonin has been shown to induce apoptosis in different cancer cells and to suppress growth of human cancer xenografts in vivo. However, its direct targets remain unknown. In this study, we demonstrate for the first time that wogonin and structurally related natural flavones, for example, apigenin, chrysin and luteolin, are inhibitors of cyclin-dependent kinase 9 (CDK9) and block phosphorylation of the carboxy-terminal domain of RNA polymerase II at Ser2. This effect leads to reduced RNA synthesis and subsequently rapid downregulation of the short-lived anti-apoptotic protein myeloid cell leukemia 1 (Mcl-1) resulting in apoptosis induction in cancer cells. We show that genetic inhibition of Mcl-1 or CDK9 expression by siRNA is sufficient to mimic flavone-induced apoptosis. Pull-down and in silico docking studies demonstrate that wogonin directly binds to CDK9, presumably to the ATP-binding pocket. In contrast, wogonin does not inhibit CDK2, CDK4 and CDK6 at doses that inhibit CDK9 activity. Furthermore, we show that wogonin preferentially inhibits CDK9 in malignant compared with normal lymphocytes. Thus, our study reveals a new mechanism of anti-cancer action of natural flavones and supports CDK9 as a therapeutic target in oncology