Seasonal change in acclimatised respiration rate of Temora longicornis

We investigated the seasonal changes in the respiration rate (R) of adult Temora longicornis (Müller) acclimatised to in situ conditions over 1 yr. Mean (±1 SE) R varied from 50.5 ± 2.8 nl O2 ind.-1 h-1 in December to 73.2 ± 3.53 nl O2 ind.-1 h-1 in August for copepods of mean body dry weight (DW) of 33.5 ± 1.1 and 26.3 ± 0.95 µg, respectively. Males represented ~8% of the total measurements, and their respiration did not differ significantly from that of females. R scaled isometrically with dry weight (DW), i.e. the allometric exponent of the power function (R = aDWb) did not differ significantly from unity (b = 0.83 to 1.35). The relationship between in situ weight-specific respiration rate (Rsp) and temperature (T) was described by a sigmoid trend with Q10 ranging from 1 to 2.88 (mean 1.57 to 1.89). In contrast, the acclimated and acutely measured Rsp of copepods maintained under optimal feeding conditions in the laboratory increased exponentially with temperature and were characterised by higher mean Q10 of 2.05 and 2.41, respectively. Acclimatised ln R increased significantly with ln DW, T, ln chlorophyll a (ln Chl) and ln egg production rate (ln EPR). Our results indicate that seasonal changes in T. longicornis respiration rate are not simply determined by body mass and temperature but also reflect copepod nutritional and reproductive condition. We argue that predictive ecological models using fixed thermal coefficient values may overestimate copepod respiration, particularly under ambient conditions limiting growth and reproduction. Our findings have important implications for the calculation of carbon flow in marine food-webs and for understanding how zooplankton physiology responds to changes in global temperature

Immobilization of inulinase on Concanavalin A attached super macroporous cryogels for production of high fructose syrup

07.02.2016 tarihine kadar kullanımı yazar tarafından kısıtlanmıştır.Bu çalışmada Aspergillus niger inulinaz enziminin immobilizasyonu için Concanavalin A (Con A) bağlı poli(etilen glikol dimetakrilat) [poli(EGDMA)] kriyojelleri kullanılmıştır. Bu amaçla, monolitik kriyojel kolon, monomer olarak EGDMA ve çapraz bağlayıcı olarak N-N'-metilen bisakrilamidin radikalik kriyokopolimerizasyonu ile hazırlanmıştır. Daha sonra Con A, glutaraldehit aktivasyonuyla poli(EGDMA) kriyojeline kovalent olarak bağlanmıştır. Kriyojellerin karakterizasyonu FTIR, SEM, EDX ve şişme çalışmalarıyla gerçekleştirilmiştir. Kriyojeller, opak, süngerimsi ve elastiktir. Poli(EGDMA) kriyojelleri oldukça yoğun gözenekli ve gözenek boyutları yaklaşık olarak 50 µm dir. Con A bağlı poli(EGDMA) kriyojelleri, sulu çözeltiden inulinaz enziminin adsorpsiyonu için kullanılmıştır. Con A bağlı poli(EGDMA) kriyojeline inulinaz adsorpsiyonu sürekli sistemde gerçekleştirilmiş ve adsorpsiyona pH, inulinaz derişimi, sıcaklık, iyonik şiddet ve akış hızının etkisi araştırılmıştır. Maksimum inulinaz adsorpsiyonu, 1.0 mg/mL inulinaz derişiminde ve pH 4.0 asetat tamponunda 27.85 mg/g kriyojel olarak hesaplanmıştır. İmmobilize inulinaz sürekli sistemde yüksek fruktozlu şurup hazırlanmasında etkili bir şekilde kullanılmıştır. İnulin, sürekli sistemde fruktoza dönüştürülmüş ve 5 dakikalık hidroliz sonunda fruktoz derişimi 0,23 mg/mL olarak bulunmuştur. Şurubun yüksek fruktoz içeriği ince tabaka kromatografisi ile gösterilmiştir.In this study, Concanavalin A (Con A) attached poly(ethylene glycol dimethacrylate) [poly(EGDMA)] cryogels were used for immobilization of Aspergillus niger inulinase. For this purposes, the monolithic cryogel column was prepared by radical cryocopolymerization of EGDMA as a monomer and N,N'-methylene-bisacrylamide as a crosslinker. Then Con A was attached by covalent binding onto poly(EGDMA) cryogel via gluteraldehyde activation. Characterization of cryogels was performed by FTIR, SEM, EDX and swelling studies. Cryogels were opaque, sponge like and elastic. Poly (EGDMA) cryogels were highly porous and pore size is approximately 50 µm. Con A attached poly(EGDMA) cryogels was used in the adsorption of inulinase from aqueous solutions. Adsorption of inulinase on the Con A attached poly (EGDMA) cryogel was performed in continuous system and the effects of pH, inulinase concentration, temperature, ionic strength and flow rate on adsorption were investigated. The maximum amount of inulinase adsorption was calculated to be 27.85 mg/g cryogel at 1.0 mg/mL inulinase concentration and acetate buffer at pH 4.0. Immobilized inulinase was effectively used in continuous preparation of high fructose syrup. Inulin was converted to fructose at continuous system and the fructose concentration was found to be 0,23 mg/mL at the end of 5 minute of hydrolysis. High fructose content of the syrup was demonstrated by thin layer chromatography

The effect of CEO power on bank risk: do boards and institutional investors matter?

We test for a link between CEO power and risk-taking in US banks. Banks are more likely to take risks if they have powerful CEOs and relatively poor balance sheets. There is little evidence that executive board size and independence have a dampening effect on the channels through which powerful CEOs influence risk-taking and some evidence that institutional investors reinforce the risk-taking preferences of powerful CEOs

Corporate governance and corporate ownership: The investment behaviour of Japanese institutional investor

In this paper, we investigate the investment behaviour of institutional investors in terms of their shareholdings in 2,938 companies listed on the Tokyo and Osaka Stock Exchanges at the end of June 2002. By doing so, we provide one of the first detailed empirical analyses of the involvement of institutional investors in the ownership structure of Japanese listed firms. At the same time, we compare this aspect of Japanese corporate governance with the shareholdings of banks in the same group of firms. Our results show that the equity investments of financial investors – institutional investors and banks – in Japanese listed companies at the end of June 2002 were predominantly in the high-tech manufacturing, traditional manufacturing and communications industries. All financial investors combined held more than 60% of the equity capital of the firms listed on the Tokyo and Osaka Stock Exchanges, with banks being the largest group of these financial investors. Further analysis shows that on average most financial investors were minority shareholders, holding up to 3% of a firm’s total shares. Domestic financial investors tended to have higher levels of ownership than foreign institutions, and small and minority shareholdings were more common among foreign financial investors than among domestic banks and institutional investors. Finally, the average shareholdings of six large Japanese financial groups in Japanese listed companies were considerable, representing an average ownership level of 3.3% of a firm’s stock. However, they were not as high as to exert a significant degree of corporate control. All in all, we conclude that as of end-June 2002, banks continued to be important shareholders of Japanese listed firms, owing around 34% of the market capitalisation of all listed firms on the Tokyo and Osaka Stock Exchanges. At the same time, institutional investors, predominantly investment firms and insurance companies, were important shareholders as well, accounting for around 27% of total market capitalisation. Moreover, we found that foreign investment funds were very important shareholders of Japanese listed firms, which confirms the general perception that foreign ownership of Japan’s corporate sector has become a rather crucial characteristic of the system of corporate governance in Japa

İlkokul Çocuklarının Kullandıkları İletişim Biçimleri

Bireyin, yaşadığı toplumun üyesi olabilmesi için, o toplumun değerlerini ve geçerli olan temel rolleri öğrenmesi gerekmektedir. Öğrenme sürecinde, birey çevresiyle kurduğu etkileşimlerle değişir ve çevresini değiştirir. Toplumsallaşma sürecindeki çocuğun anne-babası ve çevresindeki diğer yetişkinlerle olan etkileşimi, bu konu ile ilgilenen araştırmacılar tarafından, çeşitli boyutlar açısından incelenmiştir. Özellikle çocuk yetiştirme tutumları ve ailede uygulanan disiplin tekniklerinin, çocuğun kişiliğine olan etkisi araştırılan konuların başında gelmektedir. (Sears, Maccoby ve Levin 1957, Whiting ve Child 1953). Çocuk yetiştirme tutumlarının, çocuğun kişilik yapısını etkilemesinin yanısıra, bilişsel tarzlarını da (cognitive sstyle) etkilediği anlaşılmaktadır (Hesss ve Shipman, 1965). Toplumsallaşma sürecinde anne-baba ile çocuk arasında kurulan iletişimin incelendiği bir araştırmada (Jones, 1972), yüksek sözel yeteneği olan çocukların anne-babalarının : a.Çocuklarını çevreleri ile etkileşim kurmaya cesaretlendirecek bir kişilik yapısına, b.Yüksek akademik ve mesleki beklentilere, c.Çocuğun akademik ve zihinsel gelişimi için daha çok bilgiye sahip oldukları ve ayrıca, d.Dilin gelişimi ve kullanımı için çocuğa daha çok materyal ve fırsat sağladıkları bulunmuştur

In vitro comparison of four different electronic apex locators to determine the major foramen using the clearing technique

Objectives: The aim of this study was to evaluate the accuracy of four electronic apex locators (EALs) (DentaPort ZX, Raypex 5, Endo Master and VDW Gold) in detecting the major foramen using the clearing technique.Materials and Methods: Forty‑eight extracted single‑rooted extracted teeth with mature apices were used for the study and divided into four groups of 12 teeth each. All teeth were embedded in an alginate model. Electronic measurements were taken using a size 15 K‑file attached to the holder. Then, the teeth were cleared and photographed under a stereomicroscope with a digital camera. The distance between the tip of the file and the major foramen was measured by using an image analysis software program. Positive and negative values were recorded when the file tip was beyond or short of the major foramen and zero value when the file tip and the major foramen coincided. Statistical analysis was performed using the Kruskal-Wallis and Chi‑square tests at a significance level of 0.05.Results: Mean distance from the file tip to the major foramen were 0.302 ± 0.202, 0.065 ± 0.293, 0.117 ± 0.475, and 0.258 ± 0.160 mm in the DentaPort ZX, Raype 5, Endo Master, and VDW Gold groups, respectively. There were no statistically significant differences among the devices (P > 0.05). Conclusion: Under the experimental conditions, all EALs showed an acceptable determination of the major foramen.Keywords: Clearing technique, electronic apex locator, major forame

Comparative Evaluation of the Shaping Ability of Five Different Nickel-Titanium Rotary File Systems in Simulated Canals

Objectives: The aim of this study was to compare the simulated canal shaping efficiencies of five different NiTi rotary file systems. Materials and Methods: In the study, 100 transparent resin blocks with J-shaped canals were randomly divided into five groups (n=20). Simulated canals were shaped with VDW.Rotate (VR), TruNatomy (TRN), HyFlex CM (HF), EdgeFile X7 (EF), or ProTaper Next (PTN) files. Ten measuring points were detected on the pre- and post-preparation images taken from the blocks and superimposed. After preparation, the total canal width and the amount of transportation were calculated for the determined measuring levels. Zipping and ledge formation, instrument fracture and deformation, and change in working length were evaluated. The data were statistically analyzed with the Kolmogorov-Smirnov test, one-way ANOVA, Tukey test, Chi-Square test, and a Monte Carlo version of the Fisher Exact tests. The error level was taken as 0.05. Results: There were significant differences between the groups at all measuring levels in terms of total canal width after instrumentation (p = 0.001). Significant differences in the amount of transportation were found between the groups (p = 0.001) except at levels 4 (p = 0.169) and 10 (p = 0.054). Zip and instrument fractures did not occur in any group. 3 EF size 25/.04 files were deformed (p = 0.021). There was no significant difference between the groups in terms of ledge formation and working length change (p > 0.05). Conclusions: According to findings obtained in the study, transportation occurred at all 10 measuring levels with all file systems used. HF and EF systems were found to be more reliable in terms of transportation in the middle and coronal regions. Wider canal preparation was obtained with the PTN system in the middle and coronal regions

Effect of different torque settings selected during instrumentation on fracture strength of endodontically treated teeth

Background: The study evaluated the effect of root canal instrumentation at low and high torque settings on the fracture strength of endodontically treated teeth. Methods: Ninety extracted single-rooted human mandibular incisors were randomly divided into one control (CG) and two experimental groups (n=30): no instrumentation or filling (CG), instrumentation with ProTaper Universal files at low torque settings, and instrumentation with ProTaper Universal files at high torque settings. Root canal filling was performed with an epoxy resin-based sealer and gutta-percha using a single-cone technique in the experimental groups. Each specimen was tested for fracture strength. The analysis of variance and Tukey test were used to analyze the obtained data. The significance level was set at 0.05. Results: Statistically significant differences were observed between the groups (p = 0.001). While the difference between the CG and low torque groups was not significant (p > 0.05), the difference between the CG and high torque, low and high torque groups was significant (p < 0.05). Conclusion: According to this study results, since the lowest fracture strength value was observed in the high torque group, clinicians may be advised to choose the lowest torque settings recommended by the manufacturers for rotary systems

Numerical analysis of failure mechanism observed in backfills supported by masonry walls

Masonry retaining walls are designed to resist lateral forces. Their stability is essentially warranted by the correct determination of the failure surface geometry. Accordingly, this study intended to investigate the influence of wall and backfill properties that control failure surface geometry of cohesionless backfills. For this purpose, the discrete element method (DEM) is utilized, and a series of parametric studies were conducted. As the wall-joint parameters reflect the mortar quality of the blocks that constitute the masonry wall, three binder types from weak to strong were defined. Additionally, loose to dense backfill soil conditions and wall-backfill interface properties were also investigated. The results indicate that in the case of a thin rigid wall, the failure surface of dense backfill is identical with the classical earth pressure theory. However, for the masonry walls with a higher foundation width, the failure surfaces are much deeper and wider; particularly on the active side compared to the classical earth pressure theories. In addition to that the deformation mechanism and the associated failure surfaces are greatly influenced from the mortar quality which results with either a deep-seated or sliding type of failure