Laurendecumallenes A-B and laurendecumenynes A-B, halogenated nonterpenoid C-15-Acetogenins from the marine red alga Laurencia decumbens

Four new halogenated nonterpenoid C-15-acetogenins, 4:7,6:13-bisepoxy-9,10-diol-1,12-dibromopentadeca-1,2-diene (1, laurendecumallene A), 4:7,6:12-bisepoxy-9,10-diol-1,13-dibromopentadeca-1,2-diene (2, laurendecumallene 13), (3Z)-6:10,7:13-bisepoxy-12-bromo-9-hydroperoxylpentadeca-3-en-1-yne (3, laurendecumenyne A), and (3Z)-6:10,9:13-bisepoxy-12-bromo-7-chloropentadeca-3-en-1-yne (4, laurendecumenyne 13), together with one known halogenated C-15-acetogenin elatenyne (5) were isolated and identified from the organic extract of the marine red alga Laurencia decumbens. Their structures and relative stereochemistry were established by means of spectroscopic analysis including UV, IR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and ID and 2D NMR techniques. All these metabolites were submitted for the cytotoxic assay against tumor cell line A549 (human lung adenocarcinoma), but all of them were found inactive (IC50 > 10 mu g/mL).

Comparison of photobioreactors for cultivation of Undaria pinnatifida gametophytes

Undaria pinnatifida gametophytes were grown in 2.5 l bubble column and airlift reactor at 25 degreesC and light intensity of 40 mumol m(-2) s(-1) for 6 days. With aeration at 1 l min(-1), the airlift reactor yielded higher growth rate (0.12 mg DW ml(-1) d(-1)) than a bubble column (0.08 mg DW ml(-1) d(-1)). The advantages were related to the more homogeneous fluid dynamic characteristics of the airlift reactor.

INVESTIGATION OF C-PHYCOCYANIN FROM BLUE-GREEN-ALGA SPIRULINA-PLATENSIS WITH SCANNING TUNNELING MICROSCOPE

C-phycocyanin (C-PC) was isolated from blue-green alga spirulina platensis. A scanning tunneling microscope (STM) has been used to investigate its three-dimensional structure. The samples were dialyzed before the STM experiment, and then deposited on highly oriented pyrolytic graphite (HOPG). The measurement was carried out in ambient condition at room temperature. STM images showed that C-phycocyanin was uniformly distributed on solid-state substrate HOPG. The shape of C-phycocyanin is disklike with a channel in the center. It is concluded that STM has great potential to observe the structure of biliproteins and phycobilisomes.

Assessing the potential of VEGETATION sensor data for mapping snow and ice cover: a Normalized Difference Snow and Ice Index

The VEGETATION (VGT) sensor in SPOT 4 has four spectral bands that are equivalent to Landsat Thematic Mapper (TM) bands (blue, red, near-infrared and mid-infrared spectral bands) and provides daily images of the global land surface at a 1-km spatial resolution. We propose a new index for identifying and mapping of snow ice cover, namely the Normalized Difference Snow/Ice Index (NDSII), which uses reflectance values of red and mid-infrared spectral bands of Landsat TM and VGT. For Landsat TM data, NDSII is calculated as NDSIITM =(TM3 -TM5)/(TM3 +TM5); for VGT data, NDSII is calculated as NDSIIVGT =(B2- MIR)/(B2 + MIR). As a case study we used a Landsat TM image that covers the eastern part of the Qilian mountain range in the Qinghai-Xizang (Tibetan) plateau of China. NDSIITM gave similar estimates of the area and spatial distribution of snow/ice cover to the Normalized Difference Snow Index (NDSI=(TM2-TM5)/(TM2+TM5)) which has been proposed by Hall et al. The results indicated that the VGT sensor might have the potential for operational monitoring and mapping of snow/ice cover from regional to global scales, when using NDSIIVGT.

复印机送纸检测装置

复印机送纸检测装置在复印机复印过程中，经常出现无纸传送或传送两张以上纸的情况，使复印工作不能顺利进行，因此急需一种能够检测复印时有无纸传送，或传送两张以上纸的装置。对此，作者设计了一种采用红外传感器的检测装置，安装在复印机中，用于检测复印机的送纸情况..。

贵阳市阿哈湖水体和沉积物间隙水中汞的含量和形态分布初步研究

为了弄清楚酸性矿井废水的排放是否对阿哈湖造成了汞污染,我们研究了阿哈湖中汞的各种赋存形态(包括溶解气态汞、活性汞、颗粒态汞、溶解态汞、溶解态甲基汞、颗粒态甲基汞,以及沉积物间隙水体的溶解态汞和溶解态甲基汞)及其在水体和沉积物间隙水中的剖面分布.实验数据表明,溶解态甲基汞浓度在沉积物下2～5 cm处最高,随深度增加而逐渐降低,与硫酸盐还原菌(SRB)的分布相吻合,说明水体-沉积物界面是甲基汞的产生地点;并且在沉积物中高浓度硫酸根浓度高达1100mg/L时,硫酸根浓度与甲基汞浓度依然一致.

黔北新蒲红色风化壳剖面的粒度分布特征——兼论岩溶区上覆土层的物质来源

粒度分析在风化壳物源示踪方面是一种新的尝试，具有指示直接的特点。尤其当常规的地球化学、矿物学等方法难以直观反映母岩的不均一性对风化壳的影响时，粒度分布特征却可以建立两者的对应关系，从而更为合理地指示风化壳和下伏基岩的关系。黔北新蒲剖面的下伏基岩为局部夹碎屑岩薄层的连续型碳酸盐岩，本文通过对其酸不溶物及上覆红色风化壳粒度分布特征的研究，表明基岩的垂向不均一，导致上覆风化壳粒度分布特征的差异性，同时存在与下伏不同基岩酸不溶物粒度分布特征相对应的风化壳，指示了碳酸盐岩为其上覆风化壳的成土母岩。化学风化指标在剖面的变化也支持了粒度分析结果，即风化壳母岩的不均一性。从碎屑岩夹层和碳酸盐岩对风化壳提供物源的相对份额中指出碳酸盐岩的酸不溶物对上覆风化壳的优势贡献。从粒度参数角度进一步诠释了连续型碳酸盐岩风化残积成土的现实性，为正确理解中国西南岩溶区红色风化壳的成因提供了新的探索手段。综合资料显示，碳酸盐岩特别是连续型碳酸盐岩酸不溶物构成中国西南岩溶区上覆红色风化壳的主要物质来源也是可能的。

Estimation of Pose and Illuminant Direction for Face Processing

In this paper three problems related to the analysis of facial images are addressed: the illuminant direction, the compensation of illumination effects and, finally, the recovery of the pose of the face, restricted to in-depth rotations. The solutions proposed for these problems rely on the use of computer graphics techniques to provide images of faces under different illumination and pose, starting from a database of frontal views under frontal illumination.

Asymptotic behaviour of the elastic solution near the tip of a crack situated at a nonideal interface

Mishuris, G; Kuhn, G., (2001) 'Asymptotic behaviour of the elastic solution near the tip of a crack situated at a nonideal interface', Zeitschrift f?r Angewandte Mathematik und Mechanik 81(12) pp.811-826 RAE2008

Optical and ion-scattering study of SiO2 layers thermally grown on 4H-SiC

Jenkins, Tudor; Hayton, D.J.; Bailey, P.; Noakes, T.C.Q., (2002) 'Optical and ion-scattering study of SiO2 layers thermally grown on 4H-SiC', Semiconductor Science and Technology 17 pp.L29-L32 RAE2008

Asesoría en tejido plano en seda para Timbío Cauca.

[12] hojas : ilustraciones, fotografías.

Exploiting Phonological Constraints for Handshape Inference in ASL Video

Handshape is a key articulatory parameter in sign language, and thus handshape recognition from signing video is essential for sign recognition and retrieval. Handshape transitions within monomorphemic lexical signs (the largest class of signs in signed languages) are governed by phonological rules. For example, such transitions normally involve either closing or opening of the hand (i.e., to exclusively use either folding or unfolding of the palm and one or more fingers). Furthermore, akin to allophonic variations in spoken languages, both inter- and intra- signer variations in the production of specific handshapes are observed. We propose a Bayesian network formulation to exploit handshape co-occurrence constraints, also utilizing information about allophonic variations to aid in handshape recognition. We propose a fast non-rigid image alignment method to gain improved robustness to handshape appearance variations during computation of observation likelihoods in the Bayesian network. We evaluate our handshape recognition approach on a large dataset of monomorphemic lexical signs. We demonstrate that leveraging linguistic constraints on handshapes results in improved handshape recognition accuracy. As part of the overall project, we are collecting and preparing for dissemination a large corpus (three thousand signs from three native signers) of American Sign Language (ASL) video. The video have been annotated using SignStream® [Neidle et al.] with labels for linguistic information such as glosses, morphological properties and variations, and start/end handshapes associated with each ASL sign.

On the Convergence of Statistical Techniques for Inferring Network Traffic Demands

Accurate knowledge of traffic demands in a communication network enables or enhances a variety of traffic engineering and network management tasks of paramount importance for operational networks. Directly measuring a complete set of these demands is prohibitively expensive because of the huge amounts of data that must be collected and the performance impact that such measurements would impose on the regular behavior of the network. As a consequence, we must rely on statistical techniques to produce estimates of actual traffic demands from partial information. The performance of such techniques is however limited due to their reliance on limited information and the high amount of computations they incur, which limits their convergence behavior. In this paper we study strategies to improve the convergence of a powerful statistical technique based on an Expectation-Maximization iterative algorithm. First we analyze modeling approaches to generating starting points. We call these starting points informed priors since they are obtained using actual network information such as packet traces and SNMP link counts. Second we provide a very fast variant of the EM algorithm which extends its computation range, increasing its accuracy and decreasing its dependence on the quality of the starting point. Finally, we study the convergence characteristics of our EM algorithm and compare it against a recently proposed Weighted Least Squares approach.