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'Dead' DNA feeds deep sea life
Marta Paterlini
Genome Biology , 2004, DOI: 10.1186/gb-spotlight-20051006-02
Abstract: The researchers propose that the main source of DNA originates from dead cells in the surface layers of the oceans, and pelagic-benthic coupling processes control the extracellular DNA distribution in world ocean sediments. In other words, phytoplankton, cyanobacteria, and other dead organisms, free or attached to aggregates -- the so-called marine snow -- travel through the water column to the deep-sea bed, where their DNA is deposited."Our study shows that the concentration of DNA in deep-sea sediments worldwide is extremely high," study co-author Roberto Danovaro of the Marine Science Institute of the University of Ancona in Italy told The Scientist. "This makes DNA a key molecule once it is dead, as well." Danovaro suggested that researchers consider DNA as a "multifunctional molecule," acting as a reservoir of prokaryotic carbon, nitrogen and phosphorus, all vital to other organisms. The P cycle takes place on the bottom of the oceans, where new nucleic acids are generated from degraded DNA.Although DNA is a phosphate-rich molecule, it's been unclear what role genetic material plays in the P cycle. For decades, scientists measured living biomass, and detected more DNA than expected in all ecosystems. In order to look closer at the deep-sea environment, Danovaro and his colleague Antonio Dell'Anno spent 10 years collecting samples from the abyss in all oceans and seas, confirming that extracellular DNA is always a major ingredient.To make sure the DNA was truly extracellular, the researchers measured the difference between the total DNA and the DNA within living microorganisms. They confirmed the results by testing samples with an enzyme that degrades only extracellular DNA, and found that approximately 65% of the material was digested.Moreover, the researchers found that this extracellular DNA may contribute to P cycling, by sustaining 50% of the microbial life in the abyss. The DNA is selectively mineralized within the organic P pool and rapidly degraded. "The
Pokemon's cancer role revealed
Marta Paterlini
Genome Biology , 2004, DOI: 10.1186/gb-spotlight-20050120-01
Abstract: The team led, by cancer geneticist Pier Paolo Pandolfi, showed for the first time that the so-called Pokemon gene - which shares a name with a Japanese cartoon popular with children - functions as a proto-oncogene repressing the tumor suppressor ARF."This is a very elegant paper," said Gary Gilliland, a Howard Hughes scholar at Harvard Medical School, who did not participate in the study. "The observations of Dr. Pandolfi and his colleagues provide new insights into mechanisms of tumorigenesis."Gilliland noted that loss of function of critical tumor suppressors may occur through mutation or deletion and that decreased expression due to epigenetic modifications may also explain loss of function of tumor suppressors."Several lines of evidence in this report indicate that a novel mechanism of inhibition of expression of tumor suppressors, such as ARF, by transcriptional repression mediated by Pokemon, may also contribute to development of cancers," Gilliland told us.Pokemon, which stands for POK erythroid myeloid ontogenic factor, belongs to the POK family (POZ domain and Kruppel zinc fingers) of transcriptional factors. If mutated, they become transcriptional repressors through the engagement of histone deacetylases, causing chromatin remodeling and in turn tumorigenesis.Pokemon was already known to be crucial in cellular differentiation and to physically interact with other members of the POK family. These facts made Pokemon an appealing molecule to investigate further.To nail down the role of Pokemon in oncogenesis, Pandolif's team used in vitro and in vivo approaches. They established that Pokemon is an oncogene by coexpressing it in mouse embryonic fibroblasts (MEFs) with other well established oncogenes, such as Myc, H-ras, and T-Ag."Oncogenes always work in tandem and never alone, and Pokemon coexpression blocks oncogene-induced apoptosis and senescence," Pandolfi told us. "And even more interesting, by switching off Pokemon, other oncogenes were blocked too."Th
Asset Allocation Strategies Based on Penalized Quantile Regression
Giovanni Bonaccolto,Massimiliano Caporin,Sandra Paterlini
Quantitative Finance , 2015,
Abstract: It is well known that quantile regression model minimizes the portfolio extreme risk, whenever the attention is placed on the estimation of the response variable left quantiles. We show that, by considering the entire conditional distribution of the dependent variable, it is possible to optimize different risk and performance indicators. In particular, we introduce a risk-adjusted profitability measure, useful in evaluating financial portfolios under a pessimistic perspective, since the reward contribution is net of the most favorable outcomes. Moreover, as we consider large portfolios, we also cope with the dimensionality issue by introducing an l1-norm penalty on the assets weights.
Cistectomía radical laparoscópica con extracción de pieza por vagina: Caso clínico
Vitagliano,Gonzalo; Villasante,Nicolas; Paterlini,Juan; Ameri,Carlos; Mazza,Osvaldo;
Archivos Espa?oles de Urología (Ed. impresa) , 2009, DOI: 10.4321/S0004-06142009000400007
Abstract: objective: to report a case of laparoscopic radical cystectomy and pelvic lymphadenectomy with vaginal extraction of the surgical specimen in an elderly patient with muscle invasive bladder tumor. method: a 78 year old patient with history of hematuria was diagnosed of muscle invasive bladder cancer. lapa-roscopic radical cystectomy and pelvic lymphadenectomy with vaginal extraction of the surgical specimen was performed without incident. results: operative time was 240 minutes, surgical bleeding was 200 ml and hospital stay 8 days. the patient evolved uneventfully and remains disease free after 9 months of follow-up. conclusion: laparoscopic radical cystectomy provides adequate oncologic results with decreased morbidity, making this surgery an attractive alternative for the management of patients in a delicate condition.
A reinser o escolar na área de oncologia infantil – avan os & perspectivas
Ana Carolina Carvalho Rocha Paterlini,Magali Roseira Boemer
Revista Eletr?nica de Enfermagem , 2008,
Abstract: A proposta deste estudo é um ensaio sobre o tema, mencionando alguns avan os e perspectivas no que tange à reinser o escolar dessas crian as. é importante que a crian a com cancer mantenha sua escolaridade, preservando sua vida normal, seu desenvolvimento integral e tenha esperan a de cura para construir seu futuro. Porém, sua reinser o escolar tem sido difícil para professores, familiares e para ela própria. Os professores enfrentam dificuldades em como lidar com esta crian a frente aos seus colegas de classe e relacionadas à falta de informa o sobre a doen a. Os familiares sofrem com a preocupa o diante da integridade física e emocional da crian a, preferindo, muitas vezes, mantê-las em casa. Já as crian as lidam com a desinforma o, curiosidade e zombaria, face às mudan as na sua aparência física (perda de peso, queda de cabelo e uso de máscara).
Adaptive Minimax Estimation over Sparse $\ell_q$-Hulls
Zhan Wang,Sandra Paterlini,Frank Gao,Yuhong Yang
Statistics , 2011,
Abstract: Given a dictionary of $M_n$ initial estimates of the unknown true regression function, we aim to construct linearly aggregated estimators that target the best performance among all the linear combinations under a sparse $q$-norm ($0 \leq q \leq 1$) constraint on the linear coefficients. Besides identifying the optimal rates of aggregation for these $\ell_q$-aggregation problems, our multi-directional (or universal) aggregation strategies by model mixing or model selection achieve the optimal rates simultaneously over the full range of $0\leq q \leq 1$ for general $M_n$ and upper bound $t_n$ of the $q$-norm. Both random and fixed designs, with known or unknown error variance, are handled, and the $\ell_q$-aggregations examined in this work cover major types of aggregation problems previously studied in the literature. Consequences on minimax-rate adaptive regression under $\ell_q$-constrained true coefficients ($0 \leq q \leq 1$) are also provided. Our results show that the minimax rate of $\ell_q$-aggregation ($0 \leq q \leq 1$) is basically determined by an effective model size, which is a sparsity index that depends on $q$, $t_n$, $M_n$, and the sample size $n$ in an easily interpretable way based on a classical model selection theory that deals with a large number of models. In addition, in the fixed design case, the model selection approach is seen to yield optimal rates of convergence not only in expectation but also with exponential decay of deviation probability. In contrast, the model mixing approach can have leading constant one in front of the target risk in the oracle inequality while not offering optimality in deviation probability.
Primer registro de reproducción de la Gaviota Cocinera (Larus dominicanus) en la Bahía Samborombón, provincia de Buenos Aires, Argentina
Mauco,Laura; Paterlini,Carla; Isaldo,Diego I.; Quintero Blanco,Sergio A.; Navarro,Maximiliano;
El hornero , 2007,
Abstract: we describe a new kelp gull (larus dominicanus) colony, the most northern one along the argentine atlantic coast, located near punta rasa reserve, samborombón bay. the colony was found on one of several island of the san clemente's tidal creek located near san clemente del tuyú harbour. the first visit to the colony was made during courtship and nest formation in 3 september 2005. the second visit was made during the egg laying period between 24-26 september 2005. a total of 54 nests were found, 50 of them upon pickle weed, 2 upon dense-flowered pampas grass and 2 in the mud near a burrowing crab area. on 15 december 2005 we counted a total of 64 chicks in 54 nests. although this is the first record of kelp gull reproduction in the area, local fishermen recall this colony being there since at least 20 years ago. its location near san clemente harbour suggests that human presence may be frequent and that egg collection could occur frequently.
Métodos gravi-magnetométricos modernos para analizar las características estructurales de la plataforma continental Argentina
Introcaso,Antonio; Ghidella,Marta Elba; Ruiz,Francisco; Crovetto,Carolina Beatriz; Introcaso,Beatriz; Paterlini,Carlos Marcelo;
Geoacta , 2008,
Abstract: the argentinean continental shelf will be studied by analysing the continental and the oceanic crusts, the faulting and the neighbour sedimentary basins. in the frame of an academic agreement with copla (national commission on the limits of the continental shelf), which leads to determine the limits of our shelf, a preliminary study on the claromecó basin (buenos aires province and the continental shelf) was performed. to the traditional gravi-magnetometric methods employed to define the model from 2d, 2?d and 3d inversions, we have incorporated the following ones to our study: a) semi-empirical methods: euler and werner deconvolution, analytical signal and gradients, which allow finding lineaments, contacts and faults. b) determination of the curie isoterm from spectral analysis of magnetic anomalies (determination of the basement top and bottom depths and the curie temperature). its rises or falls are important to understand the actual crustal state. c) studies of the crustal characteristics (thickness and densities, isostatic balance) from the geoid undulations n, and the future mobility. d) double inversion of gravity and geoid, in order to obtain a more consistent model. alter the application of this methodology to the claromecó basin, very important lineaments were found, and the isostatic balance was certified. the basin was found to present a sedimentary thickness of one third the normal crustal thickness of the area.
Las Secuencias Depositacionales del Plioceno-Cuaternario en la Plataforma Submarina adyacente al Litoral del Este Bonaerense Pliocene-Quaternary depositional sequences of the continental shelf adjacent to eastern Buenos Aires Province, Argentina
Gerardo Parker,Roberto A Violante,C. Marcelo Paterlini,Irundo P Costa
Latin American Journal of Sedimentology and Basin Analysis , 2008,
Abstract: Se describen las características sismoestratigráficas, sedimentológicas y morfológicas del sector de plataforma submarina adyacente al este bonaerense. El trabajo se basa en los resultados obtenidos durante el desarrollo de sucesivos proyectos destinados al estudio de la cubierta sedimentaria del Plioceno-Cuaternario y reciente, utilizando metodologías de relevamiento sísmico de reflexión de media a alta resolución y muestreos de sedimentos. El sector de plataforma estudiado constituye una típica plataforma submarina silicoclástica de margen pasivo, de gran extensión y suave relieve. Su configuración morfológica está caracterizada por relieves aterrazados con una cobertura sedimentaria de depósitos arenosos relicto a palimpsestos que resultaron del retrabajamiento de sistemas costeros de playas, barreras y lagunas litorales durante el retroceso de la línea de costa como consecuencia del ascenso del nivel del mar durante la transgresión postglacial, con una etapa final de remodelado parcial durante el descenso del nivel del mar del Holoceno superior. Se diferencian dos ámbitos, la plataforma interior ("Terraza Rioplatense", entre la línea de costa y los 30/40 m de profundidad) con geoformas ajustadas a la hidrodinámica actual, y la plataforma exterior (entre la isobata de 70 m y el borde exterior de la plataforma en transición al talud), con sedimentos relicto de poca movilidad; en ambas se hallan relieves pre-transgresivos labrados en depósitos marinos y continentales del Plio-Pleistoceno que afloran bajo la cubierta sedimentaria reciente. Un escalón abrupto de 30/40 m de desnivel separa ambas plataformas. La secuencia estratigráfica estudiada está constituida por seis Secuencias Depositacionales (SD 1 a SD 6 de techo a base) que representan paquetes sedimentarios separados por discordancias. La SD 6 constituye la base de la secuencia, y corresponde a depósitos marinos del Mioceno correlacionables con las unidades costeras conocida como "Paranense-Entrerriense-Chapadmalense". La SD 5 son depósitos marinos en transición a continentales equivalentes a la Fm Barranca de los Lobos del litoral marplatense y a la unidad conocida como "Fm Puelches Equivalente" del Plioceno. La SD 4 está caracterizada por sedimentos marinos correspondientes al denominado "Interensenadense" en el litoral bonaerense, de edad aproximada a los 2,41 Ma (Plioceno superior), y se reconocen en ella diversas sismofacies de ambientes marinos, costeros y continentales con una secuencia litológica granodecreciente hacia arriba. La SD 3, marina, tiene la particularidad de tener una distribuc
Sismoestratigrafia y evolución geomorfológica del talud continental adyacente al litoral del este bonaerense, Argentina
Roberto A. Violante,C. Marcelo Paterlini,I. Pastor Costa,F. Javier Hernández-Molina
Latin American Journal of Sedimentology and Basin Analysis , 2010,
Abstract: El Margen Continental Argentino es uno de los márgenes más extensos del mundo (2 x 10(6) km2) cuyo mayor desarrollo, entre 35 y 48oS, corresponde a un típico margen pasivo volcánico. Allí se desarrollan los siguientes rasgos: plataforma, talud, emersión y el Ca ón Submarino Mar del Plata. Este trabajo describe los aspectos morfosedimentarios, estratigráficos y evolutivos del talud adyacente al litoral del este bonaerense. El estudio se basó en información sísmica mono y multicanal de alta resolución complementada con el análisis de muestras del fondo marino, fundamentalmente testigos verticales. El talud se desarrolla entre 120 y 3500 m de profundidad. Está formado por tres sectores principales. El más cercano a la plataforma es el talud superior situado por encima de los 700/800 m, de fuerte pendiente. A partir de allí se desarrolla el talud medio, constituido por la Terraza Ewing, cuya superficie de baja pendiente llega hasta los 1300 m de profundidad. Finalmente, el talud inferior vuelve a ser de fuerte pendiente y llega hasta los 3500 m, desde donde grada hacia la emersión continental. El talud es atravesado por el Ca ón Submarino Mar del Plata, que comienza alrededor de los 500 m de profundidad aunque adquiere una típica configuración de valle en V entre 1200 y 3700 metros. La cobertura sedimentaria del talud es silicoclástica, formada por fangos algo arenosos que muestran mayores porcentajes de arena e inclusive rodados en los alrededores del ca ón, particularmente en sus cabeceras. La asociación mineralógica es volcánico-piroclástica de origen pampeano-patagónico. A través de la aplicación de métodos sismoestratigráficos se identificaron siete "Secuencias Depositacionales" que abarcan desde el Cretácico superior hasta el presente, las cuales están separadas por horizontes sísmicos mayores que representan discontinuidades resultantes de la ocurrencia de significativos eventos climáticos-oceanográficos de amplia extensión regional. La sucesión de secuencias se ala que el talud comenzó a evolucionar a partir de la transición Eoceno-Oligoceno en respuesta a complejos procesos de agradación y progradación con depósitos turbidíticos y contorníticos, y formación de ca ones submarinos. Se definen cuatro etapas evolutivas principales: 1) Agradacional, del Cretácico-Eoceno, con fuerte acreción vertical del talud asociada a subsidencia térmica de la Cuenca del Salado, con alta tasa de sedimentación. 2) Desarrollo del talud durante el Eoceno superior-Mioceno medio, cuando se estructura el margen pasivo y comienza a evidenciarse la influencia de las masas de a
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