Digitally reconstructing Van Gogh's Field with Irises near Arles. Part 2: Pigment concentration maps

Colors in many paintings of great art historical value have changed over time, due to the combined effects of natural ageing, accumulated surface grime, and materials added during later conservation treatments. The physical restoration of the colors in such paintings is not possible. This article describes one part of work done to digitally restore the colors of Van Gogh's painting Field with Irises near Arles, dating from May 1888. We have used multispectral reflectance data to estimate absorption K and backscattering S parameters of Kubelka‐Munk 2‐constant theory. This was done for all 13 pigments known to have been used by Van Gogh in this painting, and based on this the concentration maps for each of these pigments were calculated. We validated the calculated concentration maps in several ways. For some pigments, we were able to predict spots on the painting where the pigment is expected to occur in unmixed form based on visual examination. For several other pigments, the concentration maps could be shown to agree with XRF data. Finally, for some other pigments the concentration maps were supported by additional evidence from microscopic examinations, remarks in Van Gogh's letters and from early color reproductions. For the 1.7 million pixels for which multispectral data is available, the average color difference between the calculated and measured spectral reflectance curves is CIEDE2000 = 1.05. This further confirms that the Kubelka‐Munk calculations are well suited to describe the variety of spectral reflectance on the painting.     

超越边界

当我们在欣赏和思考中国当代艺术的时候,面对着纷繁的潮流变化,无论艺术家、评论家还是爱好者,总会不自抑地想接下来将会发生什么。然而,在当下日益国际化、多元化的社会文化背景之下,当代艺术也越来越趋向一种非主流性,不同文化地区的艺术家共同肩负起了探索当代艺术发展的使命。由是,当代艺术     

MIPS Technologies美普思科技公司

回顾2010: 2010年重大产品/技术新闻: 1.推出新的1074K一致处理系统,为现有CPU内核自定义实现提供高性能. 2.展示了全球第一款Android机顶盒 3.优化关键软件平台,包括Skype、Adobe Flash Player、Yahoo!TV Widgets等. 2010年重要营运策略 1.宣布进入移动处理器市场,宣布了移动电话开发MIPS-Based解决方案的多项授权. 2.更加注重提供完整硬/软件解决方案和参考平台.     

Large-scale dendrimer-based uneven nanopatterns for the study of local arginine-glycine-aspartic acid （RGD） density effects on cell adhesion

Cell adhesion processes are governed by the nanoscale arrangement of the extracellular matrix （ECM）, being more affected by local rather than global concentrations of cell adhesive ligands. In many cell-based studies, grafting of dendrimers on surfaces has shown the benefits of the local increase in concentration provided by the dendritic configuration, although the lack of any reported surface characterization has limited any direct correlation between dendrimer disposition and cell response. In order to establish a proper correlation, some control over dendrimer surface deposition is desirable. Here, dendrimer nanopatterning has been employed to address arginine-glycine-aspartic acid （RGD） density effects on cell adhesion. Nanopatterned surfaces were fully characterized by atomic force microscopy （AFM）, scanning tunneling microscopy （STM） and X-ray photoelectron spectroscopy （XPS）, showing that tunable distributions of cell adhesive ligands on the surface are obtained as a function of the initial dendrimer bulk concentration. Cell experiments showed a clear correlation with dendrimer surface layout： Substrates presenting regions of high local ligand density resulted in a higher percentage of adhered cells and a higher degree of maturation of focal adhesions （FAs）. Therefore, dendrimer nano- patterning is presented as a suitable and controlled approach to address the effect of local ligand density on cell response. Moreover, due to the easy modification of dendrimer peripheral groups, dendrimer nanopatterning can be further extended to other ECM ligands having density effects on cells.     

论我国科技中介机构体系的最优选择

论述了科技中介机构本身的类型与特点．指出了它更适宜选择隐名合伙、有限合伙以及两合公司等组织形式。阐述了完善的科技中介机构体系应包括政府支持、民营非营利和商业机构三大类；从功能范围角度看，应涵盖直接参与服务对象技术创新过程的机构；主要利用技术、管理和市场等方面的知识为创新主体提供咨询服务的机构以及主要为科技资源有效流动、合理配置提供服务的机构。     

Process Parameters Affecting Listeria innocua Inactivation by Pulsed Light

The impact of several processing parameters on the effectiveness of pulsed light (PL) technology was investigated. The distribution of the light on the surface of the PL treatment chamber and the fluence striking on the sample under different treatment conditions were evaluated. Higher pulse fluences were registered when input voltage increased and the distance from the sample to the light source decreased. Distance from the sample to the xenon lamp also played a major role in the light distribution onto the surface of the treatment zone. Whereas quartz shelf placed close to the xenon lamp resulted in a non-uniform distribution of fluence, a homogeneous light distribution was found when increasing the distance to the flash lamp. Moreover, the impact of several PL processing parameters on microbial inactivation was investigated. Neither pulse voltage nor total voltage determined the antimicrobial effectiveness of PL technology in the operating range tested. Reduction in Listeria innocua counts increased with the number of pulses and the pulse fluence, being total fluence reaching the samples the most relevant process factor affecting microbial inactivation by PL. Considering the importance of this processing parameter, an accurate quantification of the fluence striking on the sample will be needed in order to design effective PL treatments.     

Changes in pigment profile and surface colour of fig (Ficus carica L.) during drying

In this study, anthocyanins in three fresh fig varieties (Ficus carica L.) cultivated in Turkey were characterised and quantified by HPLC/DAD and HPLC/MS. In addition, the carotenoid composition of Sar?lop and Sar?zeybek, yellow fig varieties, was determined, and then the ripening‐ and drying‐related changes in carotenoids and surface colour of figs were monitored during conventional sun‐drying. Four different anthocyanins, cyanidin‐3‐glucoside, cyanidin‐3,5‐diglucoside, cyanidin‐3‐rutinoside (major anthocyanin) and pelargonidin‐3‐glucoside, were identified in samples. Lutein, zeaxanthin, β‐cryptoxanthin and β‐carotene were carotenoids in yellow fig varieties. Approximately 80% of carotenoid compounds in yellow fig varieties degraded at the end of drying (i.e. seventh day). L (lightness), a (redness and greenness) and b (yellowness and blueness) colour parameters were measured by Hunter Lab system. Great changes in carotenoid composition and surface colour were observed at ripening stage on tree. A significant reduction in L and b values that refers to browning in figs was made in the first 3 days of drying process.     

Capacitated clustering problem in computational biology: Combinatorial and statistical approach for sibling reconstruction

The capacitated clustering problem (CCP) has been studied in a wide range of applications. In this study, we investigate a challenging CCP in computational biology, namely, sibling reconstruction problem (SRP). The goal of SRP is to establish the sibling relationship (i.e., groups of siblings) of a population from genetic data. The SRP has gained more and more interests from computational biologists over the past decade as it is an important and necessary keystone for studies in genetic and population biology. We propose a large-scale mixed-integer formulation of the CCP for SRP that is based on both combinatorial and statistical genetic concepts. The objective is not only to find the minimum number of sibling groups, but also to maximize the degree of similarity of individuals in the same sibling groups while each sibling group is subject to genetic constraints derived from Mendel's laws. We develop a new randomized greedy optimization algorithm to effectively and efficiently solve this SRP. The algorithm consists of two key phases: construction and enhancement. In the construction phase, a greedy approach with randomized perturbation is applied to construct multiple sibling groups iteratively. In the enhancement phase, a two-stage local search with a memory function is used to improve the solution quality with respect to the similarity measure. We demonstrate the effectiveness of the proposed algorithm using real biological data sets and compare it with state-of-the-art approaches in the literature. We also test it on larger simulated data sets. The experimental results show that the proposed algorithm provide the best reconstruction solutions.