Ultraviolet-B exposure induces photo-oxidative damage and subsequent repair strategies in a desert cyanobacterium Microcoleus vaginatus Gom.

Biological soil crusts are important in reversing desertification. Ultraviolet radiation, however, may be detrimental for the development of soil crusts. The cyanobacterium Microcoleus vaginatus can be a dominant species occurring in desert soil crusts all over the world. To investigate the physico-chemical consequences of ultraviolet-B radiation on M. vaginatus, eight parameters including the contents of chlorophyll a, reactive oxygen species, malondialdehyde and proline, as well as the activities of photosynthesis, superoxide dismutase (EC 1.15.1.1), peroxiclase (EC 1.11.1.7) and catalase (EC 1.11.1.6) were determined. As shown by the results of determinations, ultraviolet-B radiation caused decreases both in contents of chlorophyll a and in ratios of variable fluorescence over maximum fluorescence that indicate the growth and photosynthesis of M. vaginatus, besides, increases both in levels of reactive oxygen species and in contents of malondialdehyde and proline, while intensified activities of superoxide dismutase, peroxiclase and catalase reflecting the abilities of enzymatic preventive substances to oxidative stress of the treated cells. Therefore, ultraviolet-B radiation affects the growth of M. vaginatus and leads to oxidative stress in cells. Under ultraviolet-B radiation, the treated cells can improve their antioxidant abilities to alleviate oxidative injury. The change trends of reactive oxygen species, superoxide dismutase, peroxiclase and catalase are synchronous. These results suggest that a balance between the antioxidant system and the reactive oxygen species content may be one part of a complex stress response pathway in which multiple environmental factors including ultraviolet-B radiation affect the Survival of M. vaginatus. (C) 2009 Elsevier Masson SAS. All rights reserved.

Effects of salt stress on carbohydrate metabolism in desert soil alga Microcoleus vaginatus Gom.

The effects of salt stress on carbohydrate metabolism in Microcoleus vaginatus Gom., a cyanobacterium isolated from desert algal crusts, were investigated in the present study. Extracellular total carbohydrates and exopolysaccharides (EPS) in the culture medium produced by M. vaginatus increased significantly during the growth phase and reached a maximum during the stationary phase. The production of extracellular carbohydrates also significantly increased under higher salt concentrations, which was attributed to an increase in low molecular weight carbohydrates. In the presence of NaCl, the production of cellular total carbohydrates decreased and photosynthetic activity was impaired, whereas cellular reducing sugars, water-soluble sugars and sucrose content and sucrose phosphate synthase activity increased, reaching a maximum in the presence of 200 mmol/L NaCl. These parameters were restored to original levels when the algae were transferred to a non-saline medium. Sodium and K+ concentrations of stressed cells decreased significantly and H+-ATPase activity increased after the addition of exogenous sucrose or EPS. The results suggest that EPS and sucrose are synthesized to maintain the cellular osmotic equilibrium between the intra- and extracellular environment, thus protecting algal cells from osmotic damage, which was attributed to the selective exclusion of cellular Na+ and K+ by H+-ATPase.

Salt tolerance of Microcoleus vaginatus Gom., a cyanobacterium isolated from desert algal crust, was enhanced by exogenous carbohydrates

Microcoleus vaginatus isolated from a desert algal crust of Shapotou was cultured in BG-11 medium containing 0.2mol l(-1) NaCl or 0.2mol l(-1) NaCl plus 100mg l(-1) sucrose, extracellular polymeric substances (EPS) or hot water-soluble polysaccharides (HWP), respectively. Photosynthetic oxygen evolution rates, photosystem 11 activity (Fv/Fm) and dark respiration of NaCl-stressed cells were enhanced significantly by the added sucrose or EPS under salt stress conditions (0.2mol l(-1) NaCl). Compared with cells treated with salt alone, sodium contents in cells reduced significantly; the content of cellular total carbohydrate did not change, and intracellular sucrose, water-soluble sugar increased significantly following the addition of exogenous carbohydrates. Sucrose synthase (SS) activity of NaCl-stressed cells increased following the addition of sucrose, and sucrose phosphate synthase (SPS) activity of NaCl-stressed cells increased following the addition of exogenous sucrose, EPS or HWP compared with cells stressed with NaCl only. The results suggested that the extruded EPS might be re-absorbed by cells of M. vaginatus as carbon source, they could increase salt tolerance of M. vaginatus through the changes of carbohydrate metabolism and the selective uptake of sodium ions. (C) 2003 Elsevier Science Ltd. All rights reserved.

Grade of membership (GoM) por algoritmos genéticos

Muitas vezes é necessário trabalhar com variáveis categóricas, porem há um número restrito de análisesque as abordam. Uma boa técnica de segmentação é a grade of membership (GoM), muito utilizada na área médica, em psicologia e em sociologia. Essa metodologia possui uma interpretação interessante baseada em perfis extremos (segmentos) e grau de pertencimento. Porém o modelo possui grande complexidade de estimação dos parâmetros pormáxima verossimilhança. Assim, neste trabalho propõe-se o uso de algoritmos genéticos para diminuir a complexidade e o tempo de cálculo, e aumentar a acurácia. A técnica é nomeada de Genetics Algorithms grade of membership (GA-GoM). Para averiguar a efetividade, o modelo foi primeiramente abordado por simulação – foi executado um experimento fatorial levando em conta o número de segmentos e variáveis trabalhadas. Em seguida, foi abordado um caso prático de segmentação de engajamento em redes sociais. Os resultados são superiores para modelos de maior complexidade. Conclui-se, assim, que é útil a abordagem para grandes bases de dados que contenham dados categóricos.

GOM : new genetic optimizing model for broadcasting tree in MANET

Data broadcasting in a mobile ad-hoc network (MANET) is the main method of information dissemination in many applications, in particular for sending critical information to all hosts. Finding an optimal broadcast tree in such networks is a challenging task due to the broadcast storm problem. The aim of this work is to propose a new genetic model using a fitness function with the primary goal of finding an optimal broadcast tree. Our new method, called Genetic Optimisation Model (GOM) alleviates the broadcast storm problem to a great extent as the experimental simulations result in efficient broadcast tree with minimal flood and minimal hops. The result of this model also shows that it has the ability to give different optimal solutions according to the nature of the network.

Paloma Fernández Gomá : latidos de poesía que unen orillas

En la lírica española contemporánea ya no cabe duda de que la poesía de mujer constituye un aporte significativo. Dentro de su entramado, en la panorámica actual de la lírica femenina de Andalucía, Paloma Fernández Gomá se perfila como una de las poetas más interesantes y singulares. Nacida en Madrid y asentada en Algeciras (Cádiz) desde niña, su poesía se inicia tempranamente pero recién se da a conocer en 1991 con El ocaso del girasol, al que le siguen hasta el momento una decena de poemarios más, con sucesivos crecimientos y maduración de expresión y sentir. Por la temática de sus obras, de ahondamiento en sí misma y en el misterio que todo lo impregna, de diálogo y comunión interrogativa con lo próximo y lo sideral, de firme voluntad de encuentro con otras orillas y culturas del Estrecho de Gibraltar y mundo andalusí, y sobre todo por la permanente y rigurosa búsqueda de una expresión "propia" y a la par reveladora de realidades e irrealidades, se ha convertido en un referente importante en el ámbito de la cultura y las Letras no sólo de la región andaluza sino de España, hecho corroborado por su inclusión en importantes antologías de lírica femenina nacionales y extranjeras.

Paloma Fernández Gomá : latidos de poesía que unen orillas

En la lírica española contemporánea ya no cabe duda de que la poesía de mujer constituye un aporte significativo. Dentro de su entramado, en la panorámica actual de la lírica femenina de Andalucía, Paloma Fernández Gomá se perfila como una de las poetas más interesantes y singulares. Nacida en Madrid y asentada en Algeciras (Cádiz) desde niña, su poesía se inicia tempranamente pero recién se da a conocer en 1991 con El ocaso del girasol, al que le siguen hasta el momento una decena de poemarios más, con sucesivos crecimientos y maduración de expresión y sentir. Por la temática de sus obras, de ahondamiento en sí misma y en el misterio que todo lo impregna, de diálogo y comunión interrogativa con lo próximo y lo sideral, de firme voluntad de encuentro con otras orillas y culturas del Estrecho de Gibraltar y mundo andalusí, y sobre todo por la permanente y rigurosa búsqueda de una expresión "propia" y a la par reveladora de realidades e irrealidades, se ha convertido en un referente importante en el ámbito de la cultura y las Letras no sólo de la región andaluza sino de España, hecho corroborado por su inclusión en importantes antologías de lírica femenina nacionales y extranjeras.

Paloma Fernández Gomá : latidos de poesía que unen orillas

En la lírica española contemporánea ya no cabe duda de que la poesía de mujer constituye un aporte significativo. Dentro de su entramado, en la panorámica actual de la lírica femenina de Andalucía, Paloma Fernández Gomá se perfila como una de las poetas más interesantes y singulares. Nacida en Madrid y asentada en Algeciras (Cádiz) desde niña, su poesía se inicia tempranamente pero recién se da a conocer en 1991 con El ocaso del girasol, al que le siguen hasta el momento una decena de poemarios más, con sucesivos crecimientos y maduración de expresión y sentir. Por la temática de sus obras, de ahondamiento en sí misma y en el misterio que todo lo impregna, de diálogo y comunión interrogativa con lo próximo y lo sideral, de firme voluntad de encuentro con otras orillas y culturas del Estrecho de Gibraltar y mundo andalusí, y sobre todo por la permanente y rigurosa búsqueda de una expresión "propia" y a la par reveladora de realidades e irrealidades, se ha convertido en un referente importante en el ámbito de la cultura y las Letras no sólo de la región andaluza sino de España, hecho corroborado por su inclusión en importantes antologías de lírica femenina nacionales y extranjeras.

El Vaticano y el estallido de la guerra civil: el Cardenal Gomá reparó el fracaso diplomático del Marqués de Magaz

La posición de la Santa Sede ante el conflicto español que se desencadena tras el golpe de estado fallido del 17 de julio de 1936 fue de gran cautela, cautela que no fue entendida por los refugiados católicos en Roma que habían huido de la tremenda persecución religiosa desatada en la zona republicana, ni por la diplomacia del bando nacional que desplazó a Roma al Marqués de Magaz y consiguió desplazar al Embajador de la República Luis Zulueta. El pésimo hacer diplomático del Marqués de Magaz, unido a la actuación expeditiva del gobierno nacional contra el obispo de Vitoria y el fusilamiento sumario por el bando nacional de varios sacerdotes que apoyaban al Partido Nacionalista Vasco hizo que en la Santa Sede se empezase a considerar a los dos bandos de forma bastante similar. En esta situación, el viaje a Roma en diciembre de 1936 del Cardenal Isidro Gomá consiguió enderezar la situación en un sentido algo más favorable para el bando nacional

Testing a framework for the quality of process models: A case study

Process modeling can be regarded as the currently most popular form of conceptual modeling. Research evidence illustrates how process modeling is applied across the different information system life cycle phases for a range of different applications, such as configuration of Enterprise Systems, workflow management, or software development. However, a detailed discussion of critical factors of the quality of process models is still missing. This paper proposes a framework consisting of six quality factors, which is derived from a comprehensive literature review. It then presents in a case study, a utility provider, who had designed various business process models for the selection of an Enterprise System. The paper summarizes potential means of conducting a successful process modeling initiative and evaluates the described modeling approach within the Guidelines of Modeling (GoM) framework. An outlook shows the potential lessons learnt, and concludes with insights to the next phases of this study.

CADASIL: molecular studies on the most common hereditary vascular dementing disorder

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the most common hereditary vascular dementia. CADASIL is a systemic disease of small and medium-sized arteries although the symptoms are almost exclusively neurological, including migraineous headache, recurrent ischemic episodes, cognitive impairment and, finally, subcortical dementia. CADASIL is caused by over 170 different mutations in the NOTCH3 gene, which encodes a receptor expressed in adults predominantly in the vascular smooth muscle cells. The function of NOTCH3 is not crucial for embryonic development but is needed after birth. NOTCH3 directs postnatal arterial maturation and helps to maintain arterial integrity. It is involved in regulation of vascular tone and in the wound healing of a vascular injury. In addition, NOTCH3 promotes cell survival by inducing expression of anti-apoptotic proteins. NOTCH3 is a membrane-spanning protein with a large extracellular domain (N3ECD) containing 34 epidermal growth factor-like (EGF) repeats and a smaller intracellular domain with six ankyrin repeats. All CADASIL mutations are located in the EGF repeats and the majority of the mutations cause gain or loss of one cysteine residue in one of these repeats leading to an odd number of cysteine residues, which in turn leads to misfolding of N3ECD. This misfolding most likely alters the maturation, targetting, degradation and/or function of the NOTCH3 receptor. CADASIL mutations do not seem to affect the canonical NOTCH3 signalling pathway. The main pathological findings are the accumulation of the NOTCH3 extracellular domain on degenerating vascular smooth muscle cells (VSMCs), accumulation of granular osmiophilic material (GOM) in the close vicinity of VSMCs as well as fibrosis and thickening of arterial walls. Narrowing of the arterial lumen and local thrombosis cause insufficient blood flow, mainly in small arteries of the cerebral white matter, resulting in tissue damage and lacunar infarcts. CADASIL is suspected in patients with a suggestive family history and clinical picture as well as characteristic white matter alterations in magnetic resonance imaging. A definitive verification of the diagnosis can be achieved by identifying a pathogenic mutation in the NOTCH3 gene or through the detection of GOM by electron microscopy. To understand the pathology underlying CADASIL, we have generated a unique set of cultured vascular smooth muscle cell (VSMC) lines from umbilical cord, placental, systemic and cerebral arteries of CADASIL patients and controls. Analyses of these VSMCs suggest that mutated NOTCH3 is misfolded, thus causing endoplasmic reticulum stress, activation of the unfolded protein response and increased production of reactive oxygen species. In addition, mutation in NOTCH3 causes alterations in actin cytoskeletal structures and protein expression, increased branching and abnormal node formation. These changes correlate with NOTCH3 expression levels within different VSMCs lines, suggesting that the phenotypic differences of SMCs may affect the vulnerability of the VSMCs and, therefore, the pathogenic impact of mutated NOTCH3 appears to vary in the arteries of different locations. Furthermore, we identified PDGFR- as an immediate downstream target gene of NOTCH3 signalling. Activation of NOTCH induces up-regulation of the PDGFR- expression in control VSMCs, whereas this up-regulation is impaired in CADASIL VSMCs and might thus serve as an alternative molecular mechanism that contributes to CADASIL pathology. In addition, we have established the congruence between NOTCH3 mutations and electron microscopic detection of GOM with a view to constructing a strategy for CADASIL diagnostics. In cases where the genetic analysis is not available or the mutation is difficult to identify, a skin biopsy is an easy-to-perform and highly reliable diagnostic method. Importantly, it is invaluable in setting guidelines concerning how far one should proceed with the genetic analyses.

Coral diseases are major contributors to coral mortality in Shingle Island, Gulf of Mannar, southeastern India

The present study reports coral mortality, driven primarily by coral diseases, around Shingle Island, Gulf of Mannar (GOM), Indian Ocean. In total, 2910 colonies were permanently monitored to assess the incidence of coral diseases and consequent mortality for 2 yr. Four types of lesions consistent with white band disease (WBD), black disease (BD), white plaque disease (WPD), and pink spot disease (PSD) were recorded from 4 coral genera: Montipora, Pocillopora, Acropora, and Porites. Porites were affected by 2 disease types, while the other 3 genera were affected by only 1 disease type. Overall disease prevalence increased from 8% (n = 233 colonies) to 41.9% (n = 1219) over the 2 yr study period. BD caused an unprecedented 100% mortality in Pocillopora, followed by 20.4 and 13.1% mortality from WBD in Montipora and Acropora, respectively. Mean disease progression rates of 0.8 +/- 1.0 and 0.6 +/- 0.5 cm mo(-1) over live coral colonies were observed for BD and WBD. Significant correlations between temperature and disease progression were observed for BD (r = 0.86, R-2 = 0.75, p < 0.001) and WBD (R-2 = 0.76, p < 0.001). This study revealed the increasing trend of disease prevalence and progression of disease over live coral in a relatively limited study area; further study should investigate the status of the entire coral reef in the GOM and the role of diseases in reef dynamics.

A scientific forum on the Gulf of Mexico: The Islands in the Stream Concept. Proceedings of the Forum: 23 January 2008, Keating Education Center, Mote Marine Laboratory, Sarasota, Florida

The Scientific Forum on the Gulf of Mexico: The Islands in the Stream Concept took place in January 2008 in Sarasota, Florida. The purpose of the meeting was to bring together scientists and managers from around the Gulf of Mexico to discuss a range of topics on our knowledge of the Gulf of Mexico, from its geology to larger-scale connectivity to the Caribbean region, and their applications to the concept of a more integrated approach to area-based management. The forum included six panels of invited experts who spoke on the oceanographic and biological features in the Gulf of Mexico, including connections with Mexico and the Mesoamerican barrier reef system, and the legal and regulatory structure currently in place. The charge to the group was to share information, identify gaps in our knowledge, identify additional potential areas for protection, and discuss available science about connectivity and the potential value of establishing a marine protected area network in the Gulf of Mexico. (PDF has 108 pages.)

人体健康状态系统辨识研究

21世纪,随着中国人口老龄化的到来,各种非传染性慢性疾病(NCD)、老年性疾病的问题和医疗费用的恶性膨胀将引发严重社会问题和医疗危机。解决当前全球医疗危机的唯一出路将医学的首要目标设定为"预防疾病和损伤,维持和促进健康"(WHO的GOM小组,1996.11)。预防疾病应着重检测从正常生理向病理生理的渐变过程。然而,这一过程中身心状态的变化规律则一直处在目前医学研究视线之外。而在人体从正常生理向病理生理某些生理特征参数必然发生变异。我们的研究发现通过对动态体表温度变化模式、血清内多蛋白表达规律,应激条件下的心电变化模式的分析可以大大提高疾病的诊断准确率。因此进一步综合利用多个生理参数的动态、长期变化规律,特别是对其变化模式进行识别,据此建立起与健康状态的关联关系,将有助于解决人类健康状态辨识的根本问题。

Spatial and temporal variability in the relative contribution of king mackerel (Scomberomorus cavalla) stocks to winter mixed fisheries off South Florida

King mackerel (Scomberomorus cavalla) are ecologically and economically important scombrids that inhabit U.S. waters of the Gulf of Mexico (GOM) and Atlantic Ocean (Atlantic). Separate migratory groups, or stocks, migrate from eastern GOM and southeastern U.S. Atlantic to south Florida waters where the stocks mix during winter. Currently, all winter landings from a management-defined south Florida mixing zone are attributed to the GOM stock. In this study, the stock composition of winter landings across three south Florida sampling zones was estimated by using stock-specific otolith morphological variables and Fourier harmonics. The mean accuracies of the jackknifed classifications from stepwise linear discriminant function analysis of otolith shape variables ranged from 66−76% for sex-specific models. Estimates of the contribution of the Atlantic stock to winter landings, derived from maximum likelihood stock mixing models, indicated the contribution was highest off southeastern Florida (as high as 82.8% for females in winter 2001−02) and lowest off southwestern Florida (as low as 14.5% for females in winter 2002−03). Overall, results provided evidence that the Atlantic stock contributes a certain, and perhaps a significant (i.e., ≥50%), percentage of landings taken in the management-defined winter mixing zone off south Florida, and the practice of assigning all winter mixing zone landings to the GOM stock should