758 research outputs found

    The Electronic and Superconducting Properties of Oxygen-Ordered MgB2 compounds of the form Mg2B3Ox

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    Possible candidates for the Mg2B3Ox nanostructures observed in bulk of polycrystalline MgB2 (Ref.1) have been studied using a combination of Z-contrast imaging, electron energy loss spectroscopy (EELS) and first-principles calculations. The electronic structures, phonon modes, and electron phonon coupling parameters are calculated for two oxygen-ordered MgB2 compounds of composition Mg2B3O and Mg2B3O2, and compared with those of MgB2. We find that the density of states for both Mg2B3Ox structures show very good agreement with EELS, indicating that they are excellent candidates to explain the observed coherent oxygen precipitates. Incorporation of oxygen reduces the transition temperature and gives calculated TC values of 18.3 K and 1.6 K for Mg2B3O and Mg2B3O2, respectively.Comment: Submitted to PR

    Obogaćivanje kefira vlaknima jabuke i limuna

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    The effects of apple and lemon fiber addition on some properties of kefir were investigated. Five different kefirs were produced (A is control, B, C, D, E, F and G: contain 0.25 % apple fiber, 0.5 % apple fiber, 1 % apple fiber, 0.25 % lemon fiber, 0.5 % lemon fiber and 1 % lemon fiber, respectively) and stored for 20 days at 4±1 °C. pH, titratable acidity, dry matter, water activity, water holding capacity, viscosity, L, a and b values, sensorial analysis, total lactic bacteria, Lactococcus spp., Leuconostoc spp. and yeast counts of kefirs were determined at 1st, 10th and 20th days of storage. The addition of apple and lemon fiber enhanced rheological, microbiological and sensorial properties of kefirs (p<0.01). Apple and lemon fiber could be used for kefir production at a rate of 0.25 or 0.5 %.Istražen je utjecaj dodatka vlakana jabuke i limuna na neka svojstva kefira. U tu svrhu proizvedeno je pet različitih kefira (A je kontrolni, B, C, D, E, F i G: sadrže 0,25 % jabučnih vlakana, 0,5 % jabučnih vlakana, 1 % jabučnih vlakana, 0,25 % limunskih vlakana, 0,5% limunskih vlakana i 1 % limunskih vlakana), koji su bili pohranjeni 20 dana na 4±1 °C. pH, titriracijska kiselost, suha tvar, aktivnost vode, kapacitet zadržavanja vode, viskoznost, L, a i b vrijednosti, senzorska analiza, ukupni broj bakterija mliječne kiseline, Lactococcus spp., Leuconostoc spp. i broj kvasaca u kefiru određeni su 1., 10. i 20. dana skladištenja. Dobiveni rezultati upućuju na to da dodatak vlakana jabuke i limuna poboljšava reološka, mikrobiološka i senzorska svojstva kefira (p<0,01), te da se vlakna jabuke i limuna mogu koristiti za proizvodnju kefira do udjela od 0,25 % ili 0,5 %

    Up-regulation of protein serine/threonine phosphatase type 2C during 1α,25-dihydroxyvitamin D3-induced monocytic differentiation of leukemic HL-60 cells

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    AbstractTreatment with 20 nM 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) caused a progressive increase in the activity of Mg2+-dependent protein serine/threonine phosphatase type 2C (PP2C) in subcellular fractions of HL-60 cells, whereas PP2C activity was relatively constant throughout all-trans retinoic acid-induced (1 μM) granulocytic differentiation. The increase in PP2C activity appeared to parallel the 1,25(OH)2D3-induced phenotypic and functional changes in HL-60 cells. Immunoblot and Northern blot analysis indicated that the increase in PP2C activity corresponded to the increased expression of PP2C protein, which was preceded by an increase in the level of mRNA for PP2Cβ. No mRNA for PP2Cα was detected in resting or 1,25(OH)2D3-stimulated HL-60 cells. These results suggest that the increased expression of PP2C is related with the 1,25(OH)2D3-induced monocytic differentiation of HL-60 cells

    A Cross-Cultural Perspective on Human-Robot Interaction and Artificial Intelligence

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    Humanity is facing a turning point in its history. Artificial Intelligence (AI) plays a crucial role not only in computer science and robotics but also in the communication between machines and machines, and between humans and machines. With the rise of this new interactive space, it is becoming ever more critical to ask what role intercultural communications will play in this complex correlation. Does culture still matter in the era of AI

    The impact assessment of cage aquaculture on benthic communities along the south eastern Black Sea

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    The present study was conducted to examine the impact of cage aquaculture on benthic communities in coastal areas (depth 25 to 50 m) from fish farming operations located along the southeastern Black Sea (Ordu-Perşembe, Trabzon-Yomra and Rize central). Sampling was conducted seasonally from April 2007 to 2009. Sediment samples were taken using Ekman Grab (box core- 0.04 m2). Temperature, salinity, and water velocity were periodically measured to determine influencing sedimentary organic matter in the sediment, oxygenation, and anoxic conditions. In addition, grain size of sediment, organic carbon content, and distribution of benthic communities were investigated. In order to determine benthic impact of fish farms on the region, Shannon – Wiener diversity index (H’), AMBI (AZTI Marine Biotic Index) and M-AMBI (Multivariate- Marine Biotic Index) indices were used. Results of current study showed that benthic zone ecological quality of stations with number 01, 02, 03, and 04 at Ordu-Perşembefish-farming habitat was found to be very low. In autumn 2008, there were 3 species which belonged to Capitella capitata (844 individuals/m2), Capitella sp. (133 individuals/m2), and Heteromastus filliformis (311 individuals/m2) at OP-01 station. In addition, the impact of Trabzon-Yomra fish-farming activity on benthic communities was low. The degree of exposure for Rize fish-farming area in all seasons was quite low, which was not a significant negative impact

    A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue

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    <p>Abstract</p> <p>Background</p> <p>Aromatase, the key enzyme in estrogen biosynthesis, is encoded by the Cyp19a1 gene. Thus far, 3 unique untranslated first exons associated with distinct promoters in the mouse Cyp19a1 gene have been described (brain, ovary, and testis-specific). It remains unknown whether aromatase is expressed in other mouse tissues via novel and tissue-specific promoters.</p> <p>Methods</p> <p>Real-time PCR was used to examine the aromatase expression levels in various C57BL/6 mouse tissues. 5'-rapid amplification of cDNA ends (5'-RACE) was used to determine the transcriptional start sites of Cyp19a1 transcripts. Promoter activity was measured using serial deletion mutants of DNA fused to the luciferase reporter gene. Primary mouse adipose fibroblasts were isolated and cultured from 16-week-old mouse gonadal fat pads.</p> <p>Results</p> <p>We systematically analyzed Cyp19a1 expression in a large number of mouse tissues, and demonstrated for the first time that aromatase was expressed in the male but not female gonadal fat pad. Subcutaneous and brown adipose tissue did not contain detectable Cyp19a1 mRNA. We used 5'-RACE to clone a novel gonadal fat-specific untranslated first exon, which is spliced onto a common junction 15 bp upstream of the translation start site. This adipose-specific first exon was mapped to approximately 75 kb upstream of the translation start site. Transfection of luciferase reporter gene plasmids containing the promoter region upstream of the adipose-specific first exon into murine 3T3-L1 adipose fibroblasts demonstrated significant basal promoter activity conferred primarily by the sequence located at -343/-1 bp. Dexamethasone significantly induced activity of this adipose-specific promoter region. Adipose-specific Cyp19a1 mRNA was expressed in primary mouse adipose fibroblasts and significantly induced by dexamethasone alone or serum plus dexamethasone.</p> <p>Conclusion</p> <p>Taken together, this research identified a novel, adipose-specific first exon of Cyp19a1 and its hormonally regulated promoter region in male murine gonadal fat. These results expand the known 5'-regulatory region of the murine Cyp19a1 gene to 75 kb upstream of the translation start site. Cyp19a1 expression in mouse adipose tissue may play an important role in reproductive biology and lipid metabolism.</p

    The Future of Storytelling in the Age of AI and Posthuman

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    Computer scientists are building a vast array of machine learning systems (often called Artificial Intelligence or AI) that can perform daily human tasks reliably, sometimes more so than humans. Indeed, AI is becoming capable of capturing the unique essence that makes us “human”: storytelling. Humans are intrinsically storytellers and able to express themselves through stories that already exist (Fisher, 1987; Frank, 2012). Moreover, people have always learnt about themselves and made sense of the rest of the world through narratives (Ebanda de B'béri, 2006; Tunçer, 2018). However, in recent years, AI-generated games and articles have already started to emerge (Fitch, 2019). While AI is able to exceed certain functions of natural human intelligence as it gains self-learning capacity in repetitive or analytical tasks, it may have the potential to harness the persuasive capabilities of storytelling. What will become of humanity if AI can perform such “human” talents as storytelling? Indeed, some have gone as far as declaring AI will be the greatest danger to humanity (Bramer, 2015). While other scholars have already hailed the arrival of the posthuman (Wolfe, 2010; Braidotti, 2013) with such advances as neural nets that allow biological (human) and silicon-based artificial brain cells to communicate with each other (Serb et al., 2020). What will the future look like if AI can harness the influential potential of storytelling? What would be the story landscape in this era of posthumanism
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