Unitary invariants of qubit systems

We give an algorithm allowing to construct bases of local unitary invariants of pure k-qubit states from the knowledge of polynomial covariants of the group of invertible local filtering operations. The simplest invariants obtained in this way are explicited and compared to various known entanglement measures. Complete sets of generators are obtained for up to four qubits, and the structure of the invariant algebras is discussed in detail.Comment: 19 pages, 1 figur

Unconstrained Nonlinear Optimization of a Distributed SWE Model Using Modis and In Situ Measurements Over the French Alps

International audienceIn this paper we propose the optimization of the snow sub-model of MORDOR using MODIS and in situ measurements for the case study of the Serre-Ponçon reservoir (one of the largest artificial lakes in Western Europe) on the Durance River in the French Alps. We consider the problem of optimizing the snow model as an unconstrained nonlinear optimization problem

An unexpected gene cluster for downstream degradation of alkylphenols in Sphingomonas sp. strain TTNP3

In silico analysis of nucleotide sequences flanking the recently found hydroquinone dioxygenase in Sphingomonas sp. strain TTNP3 revealed a gene cluster that encodes a hydroquinone catabolic pathway. In addition to the two open-reading frames encoding the recently characterized hydroquinone dioxygenase, the cluster consisted of six open-reading frames. We were able to express the three open-reading frames, hqdC, hqdD, and hqdE, and demonstrated that the three gene products, HqdC, HqdD, and HqdE had 4-hydroxymuconic semialdehyde dehydrogenase, maleylacetate reductase, and intradiol dioxygenase activity, respectively. Surprisingly, the gene cluster showed similarities to functionally related clusters found in members of the β- and γ-proteobacteria rather than to those found in other members of the genus Sphingomonas sensu lat

Adaptaciones metodológicas de muestreo para la cuantificación de gases de efecto invernadero en embalses de montaña

Hasta hace muy poco, la energía hidroeléctrica comparada con las energías térmicas era considerada como una energía limpia desde el punto de vista de los gases de efecto invernadero (GEI). Ahora, la construcción y la explotación de sistemas de embalses se enmarcan en el contexto de una importante modificación de uso del suelo a causa de una actividad que es básicamente antrópica. En efecto, las barreras de estos sistemas modifican la distribución de los ecosistemas al transformar un ecosistema fluvial y terrestre en uno acuático lacustre. Los flujos resultantes de los GEI, como el dióxido de carbono (CO2) y el metano (CH4), entre las superficies continentales, las aguas continentales y la atmósfera son completamente modificados: se suprime la absorción de CO2 por la vegetación continental (deforestación y muerte de árboles ahogados, eliminación de la vegetación del fondo del reservorio), la materia orgánica (M.O.) presente en los suelos ahogados es mineralizada siguiendo nuevas dinámicas (por ejemplo, mineralización anaerobia) generando GEI que son emitidos hacia la atmósfera y, finalmente, la M.O. particular que es transportada por los ríos desde los continentes hacia los océanos es atrapada por las barreras de los embalses. A lo largo de la última década, las retenciones de estos sistemas han sido identificados como fuentes de CO2 y CH4 para la atmósfera, bien sea en zona boreal, intermedia o tropical (Abril et al., 2005 y Tremblay y Bastien, 2009). A escala global, los embalses contribuyen entre un 4% y 12% de emisiones de origen antrópico de CO2 y CH4 respectivamente. Un 90% de estas emisiones de CH4 tendrían lugar en la región tropical (Lima et al., 2008). Estas estimaciones están basadas en un número limitado de datos adquiridos únicamente en embalses y represas tropicales de América del Sur, así como una estimación de superficies inundadas poco precisas (Downing et al., 2006). Diferentes estudios liderados por el Instituto de Investigación para el Desarrollo de Francia – IRD y la Universidad Nacional de Colombia sede Palmira han propuesto el análisis de las fuentes de carbono, así como los procesos físicos y biológicos que están al origen de las emisiones de GEI sobre diferentes sistemas de embalses de la zona tropical en Colombia. Nuestras experiencias en este dominio de la ciencia nos han permitido desarrollar y adaptar cada uno de los aspectos metodológicos que deben ser tenidos en cuenta para la cuantificación de emisiones de GEI con origen en estos tipos de ecosistemas y que ahora presentamos de manera sintetizada en este documento

Rationale and Recent Advances in Targeted Drug Delivery for Cancer Pain: Is It Time to Change the Paradigm?

BackgroundCancer pain prevalence remains high with more than 60% of patients with advanced cancer experiencing cancer-related pain. The undertreatment of pain due to concerns of opioid dependence or diversion, as well as the potential effect of opioids on tumor neogenesis, add to the suffering among cancer populations.ObjectivesThe aim of this narrative review was to assess evidence on the effectiveness, safety, cost-effectiveness, and advances of Intrathecal (IT) Drug Delivery Systems (IDDS) for the management of cancer pain.Study designThe present review was performed by searching for articles indexed in PubMed, MEDLINE, SciELO, Google Scholar, and Scopus.MethodsStudies were included if they investigated patients with chronic cancer-related pain treated with IDDS and assessed experienced pain. We performed a narrative synthesis.ResultsIDDS have demonstrated efficacy in relieving cancer pain even in the challenging treatment of head and neck cancer pain. IDDS is also associated with a large reduction in serum opioid concentrations limiting adverse effects. When combined with other analgesics commonly used in the spinal space, but not systemically, pain relief may be dramatically improved. Advances in IT drug diffusion, including mixtures created with pharmaceutical compounding, improve the safety and accuracy of this therapy. IDDS is cost-effective and safe yet remains underutilized in this patient population.LimitationsDespite numerous clinical studies, only a small number of randomized trials have been conducted to evaluate the effectiveness of IDDS for cancer pain.ConclusionsThis article presents an overview of the current state of evidence on the effectiveness, safety, cost-effectiveness, and advances of IDDS for the management of cancer pain. Despite current evidence, IDDS remains underutilized for people with cancer pain. Potential areas to facilitate its use are discussed. A shift in the paradigm of cancer pain treatment should be considered given the undertreatment rate, lack of benefits, and considerable risks associated with oral opioid medication in many patients who suffer from chronic cancer pain