A New Diterpenoid Alkaloid from the Roots of a White‐Flowering Aconitum orientale Sample

From the roots of a white‐flowering Aconitum orientale Miller sample, collected in Artvin‐?av?at, Turkey, a new diterpenoid alkaloid named aconitorientaline ( 1 ) was isolated, along with the known diterpenoid alkaloids septentiriodine, lappaconitine, finaconitine, ranaconitine, puberanidine and delstaphinine (Fig.). The structure of 1 was established on the basis of ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, NOESY, HSQC, and HMBC studies. All the known compounds were identified by comparison of their ¹H‐ and ¹³C‐NMR data and co‐TLC behavior with those of authentic samples.     

A DSC study of the effect of ascorbic acid on bound water content and distribution in chitosan-enriched bread rolls during storage

Changes of tightly and loosely bound water relative content in bread were studied using differential scanning calorimetry method. Combination of chitosan with ascorbic acid changes water redistribution between starch and gluten and in such a way can be related to bread quality and sensory properties. The decrease of the water vaporization temperatures, melting temperatures and enthalpies in fresh bread containing chitosan were detected when ascorbic acid was added in combination with chitosan. The decrease of melting peak temperature has been attributed to the increase of interaction of loosely bound water and the decrease of vaporization peak temperature has been attributed to the decrease of interaction of tightly bound water with bread components as a result of ascorbic acid addition. Freezable water amount and total water amount in crumb decrease more rapidly during first stage of staling and more slowly at the second stage of staling in the bread nutritionally fortified with chitosan.     

Kronecker representation and decompositional analysis of closed queueing networks with phase-type service distributions and arbitrary buffer sizes

Two approximative fixed-point iterative methods based on decomposition for closed queueing networks with Coxian service distributions and arbitrary buffer sizes are extended to include phase-type service distributions. The irreducible Markov chain associated with each subnetwork in the respective decompositions is represented hierarchically using Kronecker products. The two methods are implemented in a software tool capable of computing the steady-state probability vector of each subnetwork by a multilevel method at each fixed-point iteration and are compared with other methods for accuracy and efficiency. Numerical results indicate that there is a niche filled by the two approximative methods. The authors thank Jean-Michel Fourneau for pointing out Marie’s method and Brouwer’s fixed-point theorem. The first author gratefully acknowledges grant TüBA-GEBİP from the Turkish Academy of Sciences.     

Mechanical Properties of Polyethylene and Poly(Ethylene Terephthalate) Blends

The results of experimental investigation of mechanical properties in tension of polyethylene (PE) and poly(ethylene terephthalate) (PET) blends are reported. Seven types of specimens with PE/PET weight ratios of 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, and 0/100 were examined. The data on the influence of blend composition on the yield stress, breaking stress, yield strain, and ultimate elongation are obtained. The features of the effect of PE/PET ratio on the elastic properties of the blends are discussed.     

The application of tunable tridendate P‐based ligands for the Ru(II)‐catalysed transfer hydrogenation of various ketones

Two novel versatile tridendate aminophosphine–phosphinite and phosphinite ligands were prepared and their trinuclear neutral ruthenium(II) dichloro complexes were found to be effective catalysts for the transfer hydrogenation of various ketones in excellent conversions up to 99% in the presence of 2‐propanol/NaOH in 0.1 M isopropanol solution. Particularly, [Ru₃(PPh₂OC₂H₄)₂ N–PPh₂(η⁶‐p‐cymene)₃Cl₆] acts as an excellent catalyst giving the corresponding alcohols in excellent conversion up to 99% (turnover frequency ≤ 1176 h^?1). A comparison of the catalytic properties of the complexes is also discussed briefly. Furthermore, the structures of these ligands and their corresponding complexes have also been clarified using a combination of multinuclear NMR spectroscopy, infrared spectroscopy and elemental analysis. ¹H–¹³C HETCOR or ¹H–¹H COSY correlation experiments were used to confirm the spectral assignments. Copyright © 2014 John Wiley & Sons, Ltd.     

Analysis of the interface configuration and flow characteristics in tanks in a multiphase liquid–gas system using numerical simulation

A multiphase study was conducted using a turbulence model of large eddy simulation to investigate the interaction between the gaseous phase and the interface and its respective behaviour until the liquid phase movement was established, first in the near interface, as well as the presence of turbulent structures in the study of transport between phases. The results are shown for three surface configurations: a surface with waves in which the Reynolds number and friction velocity of the gaseous phase are, respectively, 210 and 0.25 m/s; a surface with small undulations, 86 and 0.10 m/s; and a flat surface, 43 and 0.05 m/s. Coherent structures are detected on both sides of the interface; these are intensified and less elongated for larger Reynolds numbers. Additionally, the interface exhibits distinct behaviour with regard to the examined phases. For the gaseous phase, it behaves like a no-slip surface.     

Exploring the quality of the mathematical tasks in the new Turkish elementary school mathematics curriculum guidebook: the case of algebra

To take its due place in the world of education, Turkey has been through serious reform initiatives in the curriculums of various school subjects since 2003. The new Turkish elementary school curriculum was prepared considering the research studies conducted in Turkey and in other countries, as well as the educational systems of developed countries and previous experiences with mathematics education in Turkey. This study attempts to provide a perspective on the nature of the instructional tasks in the new elementary school mathematics curriculum. In particular, our focus is to explore the level of cognitive demands (LCD) in the algebra tasks provided in the national elementary mathematics curriculum guidebook. This curriculum document is a major resource for administrators, stakeholders, textbook publishers and ultimately for teachers. For every learning objective, it provides sample tasks to be used in mathematics instructions. In this study, our purpose is to explore the LCD of each of these tasks by utilizing a framework developed by Smith and Stein (Math Teach Middle School 3:344–350, 1998). The framework classifies mathematical tasks according to the level of demands: lower-level and higher-level demands. While the lower-level demands are related to memorization and procedures without connections, the higher-level demands are related to procedures with connections and doing mathematics. The findings revealed that 60% of algebra tasks for each grade level required higher LCD and a great majority of the remaining tasks were at the level of procedures without connections. The findings of the study particularly inform curriculum developers about issues regarding the quality of the tasks given in the curriculum guide and provide possible suggestions to improve the implementation of the curriculum change process.     

An integer programming dynamic farm-household model to evaluate the impact of agricultural policy reforms on farm investment behaviour

We develop a multi-objective farm-household dynamic integer programming model to simulate investment behaviour in different policy and price scenarios, with a particular focus on the decoupling of the Common Agricultural Policy (CAP). The model takes into account the characteristics of individual assets, including ageing and fixity through the explicit consideration of transaction costs. A case study application in the context of arable farming in Northern Italy is provided as an example. The results emphasise different patterns of reaction of different farm-household types over time, as an effect of the varying opportunity costs of resources and initial asset endowments. Overall, this application highlights the potentialities and limits of the methodology. In particular, the approach proved to be effective in providing a variety of results depending on the individual features of each farm-household, such as the differences between: (a) a ‘no reaction’ attitude; (b) an adaptation of farm activity and assets; and (c) a radical reaction pattern guided by high-income alternatives to farming. This highlights the potential of this tool as a generator of ideas and working hypotheses. We argue that, in view of the further developments of the CAP, the use of instruments able to account for multiple objectives, dynamics and investment choices will become even more relevant in the analysis of EU agricultural policy.     

Preoperative localization of the sensorimotor area using independent component analysis of resting-state fMRI

Analysis of resting-state functional magnetic resonance imaging (fMRI) data is based on detecting low-frequency signal fluctuations in functionally connected brain areas. These synchronous fluctuations in resting-state networks have been observed in several studies with healthy subjects. In this study, we explored if independent component analysis (ICA) can be used to localize the sensorimotor area from resting-state fMRI data in patients with brain tumors. Finger-tapping activation task and resting-state blood-oxygenation-level-dependent fMRI data were acquired from 8 patients with brain tumors and 10 healthy volunteers. Sensorimotor task independent components (IC_task) were used to verify resting-state independent components (IC_rest) individually. In addition, sensorimotor IC_rests were compared between the groups and no significant differences were detected in volume, spatial correlation or temporal correlation. These results show that it is possible to localize a sensorimotor area from resting-state data using ICA in patients with brain tumors. This offers a complementary method for assessing the sensorimotor area in subjects with brain tumors who have difficulties in performing motor paradigms.     

Flavonoids of Crataegus microphylla

Crataegus microphylla C. Koch is one of the 17 species of Crataegus growing in Turkey [H.P.T. Ammon and R. Kaul (1994). Dtsch. Apoth. Ztg., 134, 2433, 2521, 2631.]. This report is part of a series on the chemical investigations of Crataegus species from Turkey. Nine flavonoids have been isolated from the leaves and flowers of C. microphylla C. Koch. The amounts of the flavonoids from the leaves and flowers of the plant were determined.