Modelling of a dynamic multiphase flash: the positive flash. Application to the calculation of ternary diagrams

A general and polyvalent model for the dynamic simulation of a vapor, liquid, liquid-liquid, vapor-liquid or vapor-liquid-liquid stage is proposed. This model is based on the -method introduced as a minimization problem by Han & Rangaiah (1998) for steady-state simulation. They suggested modifying the mole fraction summation such that the same set of governing equations becomes valid for all phase regions. Thanks to judicious additional switch equations, the -formulation is extended to dynamic simulation and the minimization problem is transformed into a set of differential algebraic equations (DAE). Validation of the model consists in testing its capacity to overcome phase number changes and to be able to solve several problems with the same set of equations: calculation of heterogeneous residue curves, azeotropic points and distillation boundaries in ternary diagrams

Disposición a pagar por un sistema integral de residuos sólidos urbanos en poblaciones Semi-urbanas

In Yucatan, the transition from rural to semi-urban communities has occurred mainly in the municipality seats; this transition comes with the problems of waste management. The municipalities oversee the Integral Urban SolidWaste Management (IUSWM); but in recent years, the public-private partnership for waste management has proved to be an effective strategy. There are few studies on the IUSWM in rural or semi-urban areas and the users’ willingness to pay, information that would help public policymakers to design adequate plans and programs for its management. Therefore, the purpose of this study is to determine the socioeconomic factors associated with the willingness to pay for the IUSWM of users in semi-urban municipalities of Yucatan. A total of 1,144 interviews were conducted in 6 semi-urban localities in Yucatan, and the data were analyzed using descriptive and inferential statistics with a Tobit regression econometric model. 69.75% of the surveyed users declared that they were willing to pay an average of 17.65 Mexican pesos (0.85 U.S. dollars) for the integral urban solid waste management. The willingness to pay decreases when the Mayan language predominates among the member of the household, and when they have fewer tangible assets and rooms. There are cultural and social factors rooted in solid waste collection, this integrated system may be accompanied by other types of economic incentives to modify consumers’ behavior towards something more beneficial for the environment, such as the homes’ income.La transición de lo rural a lo semiurbano en Yucatán ocurre principalmente en las cabeceras municipales, y trae consigo problemas de gestión de los residuos. Las autoridades municipales son las encargadas del Manejo Integral de los Residuos Sólidos Urbanos (MIRSU); pero en últimos años, la asociación entre el sector público y el privado para la gestión de los residuos resulta una estrategia eficaz. Existen pocos estudios sobre el MIRSU en zonas rurales o semiurbanas y la disposición a pagar de los usuarios, información que ayudaría a los creadores de política pública a diseñar planes y programas adecuados para su gestión. Por lo tanto, el objetivo de este estudio es determinar los factores socioeconómicos asociados a la disposición a pagar por el MIRSU de los usuarios de municipios semiurbanos de Yucatán. Se realizaron 1,144 encuestas en 6 localidades semiurbanas de Yucatán, los datos se analizaron mediante estadística descriptiva e inferencial con un modelo econométrico de regresión Tobit. El 69,75% de los usuarios encuestados declararon estar dispuestos a pagar por el manejo integral de los residuos sólidos un monto promedio de 17,65 pesos mexicanos (0,85 dólares estadounidenses). La disposición a pagar disminuye cuando predomina el idioma maya, y mientras menos activos físicos y habitaciones tenga el hogar. Existen elementos culturales y sociales arraigados en la recolección de residuos sólidos, este sistema integral puede ir acompañado de otro tipo de incentivos económicos para modificar el comportamiento de los consumidores hacia algo más beneficioso para el medio ambiente, tal como el ingreso familiar

Antibacterial effects and toxigenesis of Penicillium aurantiogriseum and P. viridicatum

The toxigenesis of one Penicillium aurantiogriseum and one Penicillium viridicatum isolates was investigated. Sterile culture filtrates of both fungi had a clear antibacterial effect only against Bacillus subtilis. The effect on B. subtilis varied with amount of filtrate used and temperature. The antibacterial activity of chloroform extracts varied with the nature of media used to grow the fungi. Different mycotoxins were identified in the fungal cultures using thin-layer chromatography. P. aurantiogriseumwas found to produce penicillic acid, terrestric acid and aurantiamine, while penicillic acid, terrestric acid, brevianamide A and xanthomegnin were produced by P. viridicatum

ANÁLISIS INFORME CONTINUIDAD DE CUIDADOS SEGÚN CRITERIO ENFERMERO.

Consensuar qué pacientes deben salir del Hospital con Informe Continuidad de Cuidados es una discusión sin solucionar dentro del foro enfermero, y cada vez son más las voces que avalan que debe ponderar el criterio enfermero y la situación específica del paciente. Objetivos:Analizar el perfil de los pacientes que salen del Hospital con Informe Continuidad de Cuidados identificando las indicaciones más prevalentes. Ver el número total de altas con Informe Continuidad de Cuidados estratificado por especialidades. Metodología: Estudio observacional descriptivo cualitativo y cuantitativo, analizando todos los informes realizados de septiembre a diciembre de 2006 en unidades Médico-Quirúrgicas. Metodología cualitativa y cuantitativa. Fuente de datos: Servidor Gestión pacientes/Gestión de cuidados e Informe de Continuidad de Cuidados. Resultados: Cuantitativos: Emitidos 234 informes sobre un total de 676 altas, supone un 35% de pacientes con Informe de Continuidad de Cuidados. El 59,4% corresponden al área médica y el 40,5% quirúrgica, siendo Urología (57%) la unidad con más informes. Cualitativos: El 57% son mujeres y el 78% mayores de 65 años. Necesidades humanas no cubiertas más prevalentes: Movilidad 29%, Piel/Mucosa 28%, Eliminación 14%, Oxigenación/Respiración 12%, Nutrición 10%, Aprendizaje 7%.. Se presentan las situaciones y diagnósticos al alta más prevalentes. Conclusiones: Tras revisión bibliográfica, el porcentaje de pacientes con Informe de Continuidad de Cuidados es alto en nuestra área (35%). Perfil: podemos decir mujer, mayor de 65 años, con deterioro importante en la movilidad e intolerancia a la actividad (encamado), con UPP o herida quirúrgica, con anticoagulantes por vía subcutánea, insulinodependiente, con sonda vesical y/o sonda nasogástrica

Filogenia del virus linfotrópico humano htlv-1 en sudamérica

Se postula que el HTLV-I salió de África hacia otras áreas del mundo incluyendo Suramérica; sin embargo, actualmente no existe un consenso sobre las rutas de introducción ni el periodo en que ocurrieron

Genome-enabled phylogeographic investigation of the quarantine pathogen Ralstonia solanacearum race 3 biovar 2 and screening for sources of resistance against its core effectors.

Phylogeographic studies inform about routes of pathogen dissemination and are instrumental for improving import/export controls. Genomes of seventeen isolates of the bacterial wilt and potato brown rot pathogen Ralstonia solanacearum race 3 biovar 2 (R3bv2), a select agent in the USA, were thus analyzed to get insight into the phylogeography of this pathogen. Thirteen of fourteen isolates from Europe, Africa, and Asia were found to belong to a single clonal lineage while isolates from South America were genetically diverse and carried ancestral alleles at the analyzed genomic loci consistent with a South American origin of R3bv2. The R3bv2 isolates share a core repertoire of thirty-one type III-secreted effector genes representing excellent candidates to be targeted with resistance genes in breeding programs to develop durable disease resistance. Towards this goal, 27 R3bv2 effectors were tested in eggplant, tomato, pepper, tobacco, and lettuce for induction of a hypersensitive-like response indicative of recognition by cognate resistance receptors. Fifteen effectors, eight of them core effectors, triggered a response in one or more plant species. These genotypes may harbor resistance genes that could be identified and mapped, cloned and expressed in tomato or potato, for which sources of genetic resistance to R3bv2 are extremely limited.National Science Foundatio

Recurring adaptive introgression of a supergene variant that determines social organization

Introgression has been proposed as an essential source of adaptive genetic variation. However, a key barrier to adaptive introgression is that recombination can break down combinations of alleles that underpin many traits. This barrier might be overcome in supergene regions, where suppressed recombination leads to joint inheritance across many loci. Here, we study the evolution of a large supergene region that determines a major social and ecological trait in Solenopsis fire ants: whether colonies have one queen or multiple queens. Using coalescent-based phylogenies built from the genomes of 365 haploid fire ant males, we show that the supergene variant responsible for multiple-queen colonies evolved in one species and repeatedly spread to other species through introgressive hybridization. This finding highlights how supergene architecture can enable a complex adaptive phenotype to recurrently permeate species boundaries

High frequency of the IVS2-2A>G DNA sequence variation in SLC26A5, encoding the cochlear motor protein prestin, precludes its involvement in hereditary hearing loss

BACKGROUND: Cochlear outer hair cells change their length in response to variations in membrane potential. This capability, called electromotility, is believed to enable the sensitivity and frequency selectivity of the mammalian cochlea. Prestin is a transmembrane protein required for electromotility. Homozygous prestin knockout mice are profoundly hearing impaired. In humans, a single nucleotide change in SLC26A5, encoding prestin, has been reported in association with hearing loss. This DNA sequence variation, IVS2-2A>G, occurs in the exon 3 splice acceptor site and is expected to abolish splicing of exon 3. METHODS: To further explore the relationship between hearing loss and the IVS2-2A>G transition, and assess allele frequency, genomic DNA from hearing impaired and control subjects was analyzed by DNA sequencing. SLC26A5 genomic DNA sequences from human, chimp, rat, mouse, zebrafish and fruit fly were aligned and compared for evolutionary conservation of the exon 3 splice acceptor site. Alternative splice acceptor sites within intron 2 of human SLC26A5 were sought using a splice site prediction program from the Berkeley Drosophila Genome Project. RESULTS: The IVS2-2A>G variant was found in a heterozygous state in 4 of 74 hearing impaired subjects of Hispanic, Caucasian or uncertain ethnicity and 4 of 150 Hispanic or Caucasian controls (p = 0.45). The IVS2-2A>G variant was not found in 106 subjects of Asian or African American descent. No homozygous subjects were identified (n = 330). Sequence alignment of SLC26A5 orthologs demonstrated that the A nucleotide at position IVS2-2 is invariant among several eukaryotic species. Sequence analysis also revealed five potential alternative splice acceptor sites in intron 2 of human SLC26A5. CONCLUSION: These data suggest that the IVS2-2A>G variant may not occur more frequently in hearing impaired subjects than in controls. The identification of five potential alternative splice acceptor sites in intron 2 of human SLC26A5 suggests a potential mechanism by which expression of prestin might be maintained in cells carrying the SLC26A5 IVS2-2A>G DNA sequence variation. Additional studies are needed to evaluate the effect of the IVS2-2A>G transition on splicing of SLC26A5 transcripts and characterize the hearing status of individuals homozygous for the IVS2-2A>G variant