Detecting Singularities with Harmonic Wavelets

A simple method,based on harmonic wavelet analysis is proposed for the decomposition of a given energy bounded signal into a periodic signal and a pulse.Alike a denoising method,the first part signal it might represent a smooth periodic function while the pulse is a singular unpredicted perturbation (taken as a fault).It will be shown that,under some general conditions,by a simple projection into two disjoint space of functions we can easily separate the periodic component of the signal from the fault (repr...     

Mitochondrial dysfunction and apoptosis in myopathic mice with collagen VI deficiency

Collagen VI is an extracellular matrix protein that forms a microfilamentous network in skeletal muscles and other organs. Inherited mutations in genes encoding collagen VI in humans cause two muscle diseases, Bethlem myopathy and Ullrich congenital muscular dystrophy. We previously generated collagen VI-deficient (Col6a1-/-) mice and showed that they have a muscle phenotype that strongly resembles Bethlem myopathy. The pathophysiological defects and mechanisms leading to the myopathic disorder were not known. Here we show that Col6a1-/- muscles have a loss of contractile strength associated with ultrastructural alterations of sarcoplasmic reticulum (SR) and mitochondria and spontaneous apoptosis. We found a latent mitochondrial dysfunction in myofibers of Col6a1-/- mice on incubation with the selective F1F(O)-ATPase inhibitor oligomycin, which caused mitochondrial depolarization, Ca2+ deregulation and increased apoptosis. These defects were reversible, as they could be normalized by plating Col6a1-/- myofibers on collagen VI or by addition of cyclosporin A (CsA), the inhibitor of mitochondrial permeability transition pore (PTP). Treatment of Col6a1-/- mice with CsA rescued the muscle ultrastructural defects and markedly decreased the number of apoptotic nuclei in vivo. These findings indicate that collagen VI myopathies have an unexpected mitochondrial pathogenesis that could be exploited for therapeutic intervention.     

The coconut pathosystem: weed hosts of nymphs of the American palm Cixiid Haplaxius crudus (Hemiptera: Fulgoroidea)

Lethal yellowing (LY) of coconut palm (Cocos nucifera L., Arecaceae) is a disease of economic importance that is caused by the phytoplasma ‘Candidatus Phytoplasma palmae’ and is transmitted by the planthopper Haplaxius crudus (Van Duzee) (Hemiptera: Cixiidae). This study explores the weeds used by H. crudus nymphs and other Cixiidae in a coconut pathosystem in southern Mexico. Nymphs were collected directly from the root system of each weed by hand or with the help of a vacuum after carefully opening the culm. This study included 11 species of weeds: nine Poaceae [Brachiaria decumbens Stapf, B. humidicola (Rendle) Schweick, B. mutica (Forssk.) Stapf, Digitaria abyssinica (Hochst. Ex A. Rich.) Stapf, Eustachys petraea (Sw.) Desv., Leersia hexandra Sw., Panicum laxum Sw., P. maximum Jacq., Paspalum notatum Flüggé]; one Cyperaceae [Cyperus ligularis L.], and one Portulacaceae: [Portulaca pilosa L.]. Brachiaria mutica, E. petraea, B. humidicola, P. maximum were identified as the principal host species for H. crudus nymphs. Brachiaria decumbens, D. abyssinica, and C. ligularis are new host records for the nymphs of H. crudus. Additionally, it was found that H. crudus may coexist with its cogeners H. skarphion Kramer (Cixiidae) and H. caldwelli Kramer (Cixiidae), on B. mutica. On C. ligularis, H. crudus may coexist with Oecleus snowi Ball (Cixiidae) nymphs. These results suggest that in the coconut pathosystem there is a complex of multitrophic interactions that should be considered in integrated management of LY.     

Eukaryotic initiation factor 6 is rate-limiting in translation, growth and transformation

Cell growth and proliferation require coordinated ribosomal biogenesis and translation. Eukaryotic initiation factors (eIFs) control translation at the rate-limiting step of initiation. So far, only two eIFs connect extracellular stimuli to global translation rates: eIF4E acts in the eIF4F complex and regulates binding of capped messenger RNA to 40S subunits, downstream of growth factors, and eIF2 controls loading of the ternary complex on the 40S subunit and is inhibited on stress stimuli. No eIFs have been found to link extracellular stimuli to the activity of the large 60S ribosomal subunit. eIF6 binds 60S ribosomes precluding ribosome joining in vitro. However, studies in yeasts showed that eIF6 is required for ribosome biogenesis rather than translation. Here we show that mammalian eIF6 is required for efficient initiation of translation, in vivo. eIF6 null embryos are lethal at preimplantation. Heterozygous mice have 50% reduction of eIF6 levels in all tissues, and show reduced mass of hepatic and adipose tissues due to a lower number of cells and to impaired G1/S cell cycle progression. eIF6(+/-) cells retain sufficient nucleolar eIF6 and normal ribosome biogenesis. The liver of eIF6(+/-) mice displays an increase of 80S in polysomal profiles, indicating a defect in initiation of translation. Consistently, isolated hepatocytes have impaired insulin-stimulated translation. Heterozygous mouse embryonic fibroblasts recapitulate the organism phenotype and have normal ribosome biogenesis, reduced insulin-stimulated translation, and delayed G1/S phase progression. Furthermore, eIF6(+/-) cells are resistant to oncogene-induced transformation. Thus, eIF6 is the first eIF associated with the large 60S subunit that regulates translation in response to extracellular signals.     

Mn_7C_3@C核壳型纳米粒子制备及其超级电容器电极特性

以甲烷作为碳源气体,块体锰作为原料,采用一种简单的直流电弧等离子体法成功制备了Mn_7C_3@C核壳型纳米粒子,用于高性能超级电容器的电极材料.所制备的Mn_7C_3@C核壳型纳米粒子平均直径为30~35nm.拉曼光谱结果显示石墨碳壳具有良好的导电性.通过循环伏安、恒电流充放电及电化学交流阻抗谱对Mn_7C_3@C核壳型纳米粒子电极材料进行电化学性能分析,结果表明其具有高比电容、快速充放电等优异的电化学性能.在扫描速率为1mV/s时,比电容最高可达185.8F/g.同时具有良好的循环稳定性,在100mV/s扫描速率下1 000次循环伏安测试后,比电容仍保持为最初的88%,与单纯Mn_7C_3(79%)相比,有明显提高.Mn_7C_3@C核壳型纳米粒子电极材料优异的电化学性能归因于其良好的核壳结构,富缺陷碳层具有良好的导电性,有助于离子的传输和结构的稳定,而内核Mn_7C_3主要产生赝电容,在C和Mn_7C_3的协同作用下产生双电层和赝电容双模式储能机制.     

Giordano Bruno and the heresy of many worlds

This paper analyses the importance of Giordano Bruno's belief in many worlds, including the Moon, the planets and the stars, in the context of his trial by the Inquisitions in Venice and Rome. Historians have claimed that this belief was not heretical and therefore was not a major factor in Bruno's trial or execution. On the contrary, by examining neglected treatises on theology, heresies and Catholic canon law, I show that the belief in many worlds was formally heretical. Multiple Christian authorities denounced it. A systematic analysis of the extant primary sources shows that Bruno's belief in many worlds was, surprisingly, of primary importance in his trial and execution. The evidence includes recent and newly discovered primary sources.     

Design of Blurring Mean-Shift Algorithms for Data Classification

The mean-shift algorithm is an iterative method of mode seeking and data clustering based on the kernel density estimator. The blurring mean-shift is an accelerated version which uses the original data only in the first step, then re-smoothes previous estimates. It converges to local centroids, but may suffer from problems of asymptotic bias, which fundamentally depend on the design of its smoothing components. This paper develops nearest-neighbor implementations and data-driven techniques of bandwidth selection, which enhance the clustering performance of the blurring method. These solutions can be applied to the whole class of mean-shift algorithms, including the iterative local mean method. Extended simulation experiments and applications to well known data-sets show the goodness of the blurring estimator with respect to other algorithms.