64 research outputs found
The enhancement of polygalacturonase and polymethylgalacturonase production on solid-state conditions by Aspergillus foetidus
No full textIn this study, a previously isolated strain of Aspergillus foetidus Ege-K-635 producing highly active polygalacturonase and polymethylgalacturonase was used for improvement of enzyme production using solid-state conditions. To enhance the enzyme yield, the mixture of two substrates such as sugar beet pulp and wheat bran, having different ratios of carbon-nitrogen and moisture levels was used. Further the effect of the amount of inoculum was investigated. Physical parameters for the highest polygalacturonase and polymethylgalacturonase production under solid state conditions were determined on wheat bran: the sugar beet pulp (1:2) mixture substrate composition having a 31:1 carbon-nitrogen ratio with 8 x 10(6) spores/gram of dry substrate as the inoculum amount. Adequate moisture levels were 75% and 70% for polygalacturonase and polymethylgalacturonase, respectively. Under these conditions, the highest activities obtained were 385 +/- 12.3 Ug(-1) on the third day for polygalacturonase and 18.3 +/- 3.2 Ug(-1) on the second day for polymethylgalacturonase.Scientific Research Commission at Celal Bayar UniversityCelal Bayar UniversityThe authors gratefully thank to the Scientific Research Commission at Celal Bayar University for providing support to carry out a part of the present work and to Dr. Ergun Taskin for obtaining and handling the beet pulp
Quantification and comparison of quorum sensing response to various quinolone molecules in Pseudomonas aeruginosa and Burkholderia thailandensis
No full textBacteria have a quorum sensing mechanism that helps them communicate to other bacteria. It helps optimize activities such as altering behavior in response to other bacteria, facilitating cell-to-cell communication, and defeating competitors. By studying different quorum sensing signaling molecules in Pseudomonas aeruginosa and Burkholderia thailandensis, we have concluded that bacteria exert synergistic and antagonistic relationship in response to their environment. Bioluminescence studies have proven that different quinolones possess different characteristics. The difference in quorum sensing response between the Pseudomonas and Burkholderia species is largely dictated by the methylation of the quinolone ring named 4-hydroxy-3-methyl-2-alkylquinolines (HMAQs) rather than unsaturation of the alkyl chain of Burkholderia species. Also, our results indicate that there is little cross-talk between the quinolone quorum sensing molecules of both P. aeruginosa and methylated Burkholderia species. Furthermore, limited response to N-oxide quinolones indicates an attenuation of the quinolone quorum sensing response.M.S.Includes bibliographical referencesIncludes vitaby Evrim Arsla
Political Endowments and Electricity Market Regulation in Turkey: An Institutional Analysis
No full textTurkey has been going through a liberalization process in its electricity market over the last decade. So far, the regulatory content of the market reforms has been in the center of attention in the literature, to the negligence of regulatory governance. However, recent studies, which applied the theoretical insights of new institutional economics to utilities regulation, have demonstrated that political endowments of the country draw the boundaries to which extent such regulatory content can be effectively implemented. In line with these studies, this paper adopts an institutional approach and attempts to identify the political endowments of Turkey in order to further analyze whether the market reforms succeeded in bringing about sufficient checks to cure the institutional problems. In other words, the paper takes a picture of the overall regulatory arena. The results show that the current regulatory structure, especially government-regulator relations, fails to meet good regulatory governance criteria. The paper also provides some policy suggestions.electricity regulation; regulatory governance; institutions
Spectroscopic observations of some long period binary systems
No full textThe long period eclipsing binaries are the best tools to determine accurate spectroscopic elements of the orbit. Unfortunately, the number of well-studied long period eclipsing binaries (LPEBs) is quite small due to necessity of long term observing programmes with big telescopes together with relatively high resolution spectrographs. At the UBT60 telescope of Akdeniz University located in TUBITAK National Observatory, we started a programme to study LPEBs spectroscopically. In this study, we present spectroscopic orbital parameters of some selected long period early-type eclipsing binary stars
Dynamic connectedness and portfolio strategies: Energy and metal markets
No full textIn this paper, we investigate the volatility spillover effect among the global commodity futures (including both energy and metal futures; global stock markets (covering both Developed and Emerging Markets); the US bond market and the US Dollar index by employing the dynamic connectedness approach of (Diebold and Yilmaz, 2012, 2014) based on the time-varying parameter vector autoregressive (TVP-VAR) model and using daily data for the period from January 3, 1992 to December 27, 2019. Our results indicate a moderate connectedness among the volatilities changing over time and approaching its peak level during 2007/08 global financial crises. In addition, we determine the optimal hedge ratios and portfolio weights for the commodity investors and portfolio managers. Our results indicate that for the equity market volatility investors, the highest hedging effectiveness can be reached by taking short positions in energy futures (such as natural gas), on the other hand for both the US bond and US Dollar volatility investors it can be reached by taking short positions in metal futures (such as gold)
The short- and long-run efficiency of energy, precious metals, and base metals markets: Evidence from the exponential smooth transition autoregressive models
No full textThe aim of this paper is to investigate the long and short-run relationship between spot and futures prices of the energy, precious metals, and base metals markets. We analyze daily data from January 1985 to February 2019. The empirical findings based on the cointegration test, which follows a nonlinear process, suggest that the spot prices of energy and metals assets have long-run relationships with their futures prices. Nonparametric Granger causality test results also indicate bi-directional causality among futures and spot prices. These findings indicate that the energy and metals markets are informationally efficient in the sense of Fama (1970). (C) 2019 Elsevier B.V. All rights reserved
BIODIVERSITY AND FLORA OF MICROFUNGI FROM SULTANA-TYPE VINEYARD SOILS IN TURKEY
No full textIn this study, the culturable microfungi flora of vineyard soils belonging to Manisa and Izmir provinces (Turkey) were investigated quantitatively and qualitatively (species composition, diversity characteristics, such as species richness, evenness). Soil samples of 62 sultana-type vineyards from five locations (Alasehir, Manisa 1, Manisa 11, Manisa III and Izmir) were collected using the Brown's technique. The soil dilution technique was used for microfungi isolation. The mean microfungi number of I fresh soil was counted to be 71 000 colony forming units (CFUs). A total of 66 species and 3 varieties belonging to 16 genera were encountered including Aspergillus, Penicillium, Cladosporium, Alternaria, Rhjzopus, Trichoderma, Chaetomium, Chrysosporium, Dreschlera, Glomerularia, Gliocladium, Fusarium, Fusidium, Nectria, Spicaria, and Rhizomucor. Members of "Aspergillus section Nigri", generally known as black Aspergilli, dominated all locations and their incidence among all isolated fungi was 80.4%. Aspergillus aculeatus was the most encountered species with 100% ratio. It was followed by A. foetidus var. pallidus with 93.3%, and A. awamori with 73.3%. The highest microfungal diversity was found in location Manisa 11 (station Saruhanh) with indexes for biodiversity as Shannon (H) 3.28, Simpson's (D) 0.93 and Evenness (J) 0.96. This is the first extensive study carried out on biodiversity and microfunci flora of vineyard soils in Turkey.TARIS-ARGE (Bornova-Izmir, Turkey)We would like to thank TARIS-ARGE (Bornova-Izmir, Turkey) for the collection of soil samples
The Impact Of Women Board Of Directors On Firm Performance
No full textBu çalışmada, Türkiye'de şirketlerin yönetim kurulunda yer alan kadın üye sayısının firmaların performansına etkisi incelenmektedir. Çalışma kapsamında 2008-2015 yılları arasında BIST-100 endeksinde yer alan firmaların yönetim kurulunda yer alan kadın sayThis paper analyzes the impact of number of women on the board of directors in Turkishkey on the performance of firms. The data covers the period between 2008-2015 for the BIST-100 companies and analyze the impact of number of women in the boards to the
Studies aimed at understanding how phosphorylation and miRNAs contribute to the circadian clock mechanism in drosophila
No full textCircadian (≈24 hr) rhythms in physiology and behavior are driven by endogenous cellular clocks that can be synchronized (entrained) by environmental cues, most notably the daily light-dark and temperature cycles. Circadian timing mechanisms in a wide variety of organisms are based on a small set of species-specific clock genes that participate in negative transcriptional feedback loops intertwined with post-transcriptional and post- translational regulatory schemes that ultimately drive cyclical gene expression. Phosphorylation is the most pervasive post-translational modification of clock proteins and is central to setting the pace of the clock. PERIOD (PER), the main repressor in animal clocks, is progressively phosphorylated during its life cycle, which has potent effects on its stability and nuclear localization. In this thesis I used D. melanogaster as an animal model system and identified a new role for PER phosphorylation in entraining to light-dark and temperature cycles. Prior work showed that the light-mediated degradation of TIMELESS (TIM), a key partner of PER, is critical for photic entrainment. My studies have significantly revised this model with the demonstration that the light-mediated degradation of TIM leads to an increase in the phosphorylation of two nearby sites on PER (S826/828), and that blocking phosphorylation at these sites causes altered entrainment, revealing a surprising new role for PER in circadian responses to environmental cues. In related work I contributed to studies that identified phosphorylation sites on the central circadian transcription factor termed CLOCK (CLK), and showed that these modifications are also involved in entrainment. Together, these studies reveal that phosphorylation of PER and CLK is not only critical for setting the pace of the clock but also its ability to interpret external time cues. In another study I found that the miRNA bantam (ban) regulates Clk through three target sites on its 3’ UTR. Flies harboring mutations in ban target sites on Clk show weaker circadian rhythms and less CLK protein staining specifically in the s-LNvs, the key circadian pacemaker cells. These findings show that ban imparts robustness to circadian rhythms by adjusting CLK levels in master pacemaker neurons, and suggest a non- conventional mode-of-operation for ban on Clk expression.Ph.D.Includes bibliographical referencesby Evrim Yildiri
Neden Vejetaryenim
No full textJ. Howard Moore's Neden Vejetaryenim (Why I Am a Vegetarian) is a striking manifesto that elevates vegetarianism from a mere dietary choice to an evolutionary and ethical foundation. Based on Darwinian evolutionary theory, the author emphasizes the biological and emotional kinship humans share with other animals, advocating for the principle of "Universal Kinship". Moore characterizes the exploitation of animals for food or entertainment as a crime akin to the slavery historically imposed on humans, arguing that the "Golden Rule" should be expanded to encompass all living beings. The book supports the argument that humans are not anatomically carnivorous and that a plant-based diet is superior both physiologically and economically, citing examples like the endurance of Turkish porters and Suez Canal workers. The work harshly critiques the brutality of slaughterhouses and the moral contradiction between human claims of "mercy" and meat consumption, inviting the reader to a fairer and more compassionate life.J. Howard Moore'un Neden Vejetaryenim adlı eseri, vejetaryenliği sadece bir diyet tercihi olmaktan çıkarıp evrimsel ve etik bir temele oturtan çarpıcı bir manifestodur. Yazar, Darwinci evrim teorisini temel alarak, insanların diğer hayvanlarla olan biyolojik ve duygusal akrabalığını vurgular ve "Evrensel Akrabalık" (Universal Kinship) ilkesini savunur. Moore, hayvanların gıda veya eğlence için sömürülmesini, geçmişte insanlara uygulanan kölelik gibi bir suç olarak nitelendirir ve "Altın Kural"ın (sana yapılmasını istemediğini başkasına yapma) tüm canlıları kapsayacak şekilde genişletilmesi gerektiğini belirtir. Kitapta, insanın anatomik olarak etçil olmadığı, bitkisel beslenmenin hem fizyolojik hem de ekonomik açıdan daha üstün olduğu, Türk hamalların ve Süveyş Kanalı işçilerinin dayanıklılığı gibi örneklerle desteklenir. Eser, mezbahalardaki vahşeti ve insanların "merhamet" iddiaları ile et tüketimi arasındaki ahlaki çelişkiyi sert bir dille eleştirerek, okuyucuyu daha adil ve şefkatli bir yaşama davet eder
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