Tuning the Peri Effect for Enantioselectivity: Asymmetric Hydrogenation of Unfunctionalized Olefins with the BIPI Ligands

The modular nature of the BIPI ligands allows for systematic optimization of each ligand region. The development of ligands optimized for asymmetric hydrogenation of the challenging unfunctionalized olefin substrate class is described. The naphthyl peri position, C‐8, has been identified as a critical stereocontrol element in the design of these ligands. Highly enantioselective ligands suitable for hydrogenation of tri‐ and tetrasubstituted olefins are detailed.     

Contents of Carotenoids, Tocopherols and Sterols in Acacia cyanophylla Seed Oils

Seeds from 12 Acacia cyanophylla ecotypes, harvested in Tunisia, were examined for their seed oil contents of carotenoids, tocopherols and phytosterols. The average carotenoid content (lutein and zeaxanthin) was ca. 102 mg kg^?1 of total extracted lipids. Lutein (ca. 97 mg kg^?1 of total extracted lipids) was usually more abundant than zeaxanthin (ca. 5 mg kg^?1 of total extracted lipids). The mean total tocopherol content was ca. 704 mg kg^?1 of total extracted lipids. The main isomer was α‐tocopherol, with more than 75 % of total tocopherols (ca. 528 mg kg^?1 of total extracted lipids), followed by γ‐tocopherol (ca. 168 mg kg^?1 of total extracted lipids) and δ‐tocopherol (ca. 86 mg kg^?1 of total lipids). High levels of phytosterols (ca. 7.8 g kg^?1 of total extracted lipids) were detected, among which β‐sitosterol was the most abundant (47 %). All these results highlight the richness of carotenoids, tocopherols and sterols in A. cyanophylla seed oil, and imply that this species might constitute a potential resource for the development of functional foods.     

A Simple Priority Mechanism for Shared-Protection Schemes

One of the major challenges of optical network operators is ensuring the stringent levels of availability required by their highest-class clients. To achieve this, we introduce relative priorities among the different primary connections contending for access to the protection paths. In this letter, we propose an analytical model for the proposed priority-enabled scheme. As a key distinguishing feature from existing literature, we derive explicit analytic expressions for the average availability and service disruption rate for the different priority classes     

Optimization of NaOH Molarity,LUSI Mud/Alkaline Activator,and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na₂SiO₃/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na₂SiO₃/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm³ and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.     

平面设计在印度尼西亚

平面设计在印尼是比较新的行业,虽然它已存在约40年.大约在上世纪70年代,“平面设计”一词才在印尼为人所知,在此之前,它被称之为“广告艺术”,因为当时它是广告的一部分.后来,两所艺术学院——万隆技术学院和印尼艺术学院把应用艺术专业从美术专业分离,自此,平面设计作为一个专业被确立并不断壮大。     

Discrete visual features modeling via leave-one-out likelihood estimation and applications

Discrete data are an important component in many image processing and computer vision applications. In this work we propose an unsupervised statistical approach to learn structures of this kind of data. The central ingredient in our model is the introduction of the generalized Dirichlet distribution as a prior to the multinomial. An estimation algorithm, based on leave-one-out likelihood and empirical Bayesian inference, for the parameters is developed. This estimation algorithm can be viewed as a hybrid expectation–maximization (EM) which alternates EM iterations with Newton–Raphson iterations using the Hessian matrix. We propose then the use of our model as a parametric basis for support vector machines within a hybrid generative/discriminative framework. In a series of experiments involving scene modeling and classification using visual words, and color texture modeling we show the efficiency of the proposed approach.     

Symbolic-to-statistical hybridization: extending generation-heavy machine translation

The last few years have witnessed an increasing interest in hybridizing surface-based statistical approaches and rule-based symbolic approaches to machine translation (MT). Much of that work is focused on extending statistical MT systems with symbolic knowledge and components. In the brand of hybridization discussed here, we go in the opposite direction: adding statistical bilingual components to a symbolic system. Our base system is Generation-heavy machine translation (GHMT), a primarily symbolic asymmetrical approach that addresses the issue of Interlingual MT resource poverty in source-poor/target-rich language pairs by exploiting symbolic and statistical target-language resources. GHMT’s statistical components are limited to target-language models, which arguably makes it a simple form of a hybrid system. We extend the hybrid nature of GHMT by adding statistical bilingual components. We also describe the details of retargeting it to Arabic–English MT. The morphological richness of Arabic brings several challenges to the hybridization task. We conduct an extensive evaluation of multiple system variants. Our evaluation shows that this new variant of GHMT—a primarily symbolic system extended with monolingual and bilingual statistical components—has a higher degree of grammaticality than a phrase-based statistical MT system, where grammaticality is measured in terms of correct verb-argument realization and long-distance dependency translation.     

Optical resources provisioning: multipoint‐to‐point lightpaths mapping in all‐optical networks

In wavelength‐division multiplexing (WDM) optical networks, the bandwidth request of a traffic stream can be much lower than the capacity of a lightpath. Efficiently grooming low‐speed connections onto high‐capacity lightpaths will improve the network throughput and reduce the network cost. In this paper, we propose and evaluate a new concept of traffic aggregation in WDM mesh networks that aims to eliminate both the bandwidth under‐utilization and scalability concerns that are typical in all‐optical wavelength routed networks. This approach relies on the multipoint‐to‐point lightpath concept. In order to assess the efficiency of our proposal, all underlying network costs are compared. To achieve this aim, we devise a new provisioning algorithm to map the multipoint‐to‐point lightpaths in the network. Our results show that the proposed aggregation technique can significantly improve the network throughput while reducing its cost. Copyright © 2005 John Wiley & Sons, Ltd.