RESUMO
Biofilters based on earthworms-microorganisms represent, particularly in developing countries, an interesting alternative for domestic wastewater treatment due to their easy operation and low cost. However, there are several operational aspects that should be better understood in order to improve their performance. This paper studies the effect of using intermittent hydraulic loading rates to improve organic matter and nutrient removal from domestic wastewater using these biofilters. Three laboratory-scale columns, operating at a 2.5 m3 m-2day-1 hydraulic loading rate, were used. The B1-24 h, B2-8 h, B3-4 h column loading rates indicate that the columns were operated continuously for 24, 8 and 4 h, respectively. Each column (biomass biofilm/earthworms, redox potential, and head loss) and its corresponding operational performance parameters (TCOD, NH4 +, NO3 -, NO2 -, TP) were monitored. The results showed that the B2-8 h intermittent hydraulic loading rate results in the best global performance, with 74%, 57%, and 20% average removal efficiencies for TCOD, nitrogen, and phosphorus, respectively. Moreover, it showed the best biomass growth (biofilm and earthworms), activity (as redox potential changes) and the lowest clogging effects (up to -1.0 cm). The intermittent operation influences the behavior of the earthworm-microorganism biofilters and offers the possibility of optimizing its global performance and achieving a resilient technology.
Assuntos
Oligoquetos , Águas Residuárias , Animais , Reatores Biológicos , Filtração , Nitrogênio/análise , Nutrientes , Fósforo , Eliminação de Resíduos LíquidosRESUMO
Biofiltration is one of the main alternatives developed to improve wastewater quality and increase its recyclability. Support materials are extremely important when using this technology since they impact the cost of the treatment. In this work, we study the use of wood chips/peanut shell as support medium within biofilters incorporating microorganisms (BM), plants and microorganisms (BPM), earthworms and microorganisms (BEM) and all organisms (hybrid biofilters, HB). These typologies were evaluated to remove organic matter from synthetic domestic wastewater. For this purpose, twelve biofilters were operated in parallel under three different nominal hydraulic rates (0.5, 1 and 1.5 m3 m-2 day-1). Previously, support materials were individually characterized and acute/chronic toxicity tests on plants (Eleocharis palustris (L.) Roem. & Schult.) and earthworms (Eisenia foetida Savigny) were driven. Results showed that both materials have good adsorbent properties, providing adequate environmental conditions for biofiltration. Moreover, non toxicological response was reported when a 25 v/v % peanut shell fraction was selected. With this fraction used in every biofilter studied, the average hydraulic conductivity was between 321 and 502 mm h-1, reaching organic matter removal efficiencies close to 80% (measured as COD), and between 40 and 63% (measured as VS). Higher efficiencies, attributed to the longer contact times, and lower clogging were observed at lower hydraulic rates. The incorporation of earthworms and plants improved the solids removal and reduced clogging. The statistical analysis indicated that the results obtained for biofilters operating at 0.5 m3 m-2 day-1 showed significant differences (p < 0.05) with respect to the other rates. Moreover, BEM were the ones that presented significant differences. As a conclusion, low-cost organic materials (wood chip/peanut shell mix) can be successfully used as support medium, since they provide adequate environmental conditions for plants and earthworms, improving the operation and maintaining contaminant (organic matter) removal within biofiltration typologies.
Assuntos
Oligoquetos , Águas Residuárias , Animais , Arachis , Filtração , MadeiraRESUMO
In this study we have analysed and compared the genomic composition, meiotic behaviour, and meiotic affinities of Zea perennis and Zea mays ssp. mays. To do so we studied the parental taxa and the interspecific hybrid Zea perennis x Zea mays ssp. mays, using classical cytogenetic methods, as well as GISH and FISH. GISH enabled us to recognize the genomic source of each chromosome involved in the meiotic configurations of this hybrid, and established the genomic affinities between their parental species. The results obtained here reinforce the hypothesis of the amphiploid origin of Zea perennis and, together with previous research, indicate that the chromosomes with divergent repetitive sequences in maize and Zea luxurians could be the remnants of a relict parental genome not shared with Zea perennis.
Assuntos
Cruzamentos Genéticos , Genoma de Planta , Hibridização in Situ Fluorescente/métodos , Zea mays/genética , Cromossomos de Plantas , DNA de Plantas/genética , Meiose , Especificidade da Espécie , Zea mays/classificaçãoRESUMO
The present review summarizes our classical and molecular cytogenetic investigations in the genus Zea. The results obtained from the meiotic behavior analysis of Zea species and hybrids, confirm the amphiploid nature of all species in the genus, with a basic number of x = 5 chromosomes. All species with 2n = 20 are diploidized allotetraploids, whereas Z. perennis (2n = 40) is an allooctoploid with four genomes somewhat divergent from one another. These analyses also revealed the existence of postzygotic reproductive isolation among Zea species. Our studies using genomic in situ hybridization (GISH) provide evidence about the evolutionary relationships among maize and its allied species, and reveal remarkable genomic divergences. Particularly, knob sequences were not completely shared between taxa previously considered to be closely related. Our data strongly suggest that the teosinte Z. mays parviglumis is not the only progenitor of cultivated maize. Introgression of Tripsacum into cultivated maize cannot be discarded.
Assuntos
Genoma de Planta , Zea mays/genética , DNA de Plantas/genética , Hibridização In Situ/métodos , Hibridização in Situ Fluorescente , Zea mays/classificação , Zea mays/ultraestruturaRESUMO
BACKGROUND: Home oxygen therapy is the only intervention that significantly prolongs survival of patients with chronic obstructive pulmonary disease. Since this therapy is expensive, it is imperative to calculate its cost-benefit ratio. AIM: To compare health care costs for patients in a home oxygen therapy program, with those of a similar group of patients in a waiting list for this therapy. MATERIAL AND METHODS: A retrospective analysis of 21 patients on home oxygen therapy for 36 months or less and a group of 13 patients in the waiting list during a similar lapse. Medical consultations, drugs delivered and the cost of oxygen therapy were considered among ambulatory costs. Hospitalization costs included the number of days on regular or intermediary care beds, laboratory tests and drugs delivered. RESULTS: The annual health care costs for patients on home oxygen therapy were 709,656 Chilean pesos and the costs for patients in the waiting list were 797,320 Chilean pesos. CONCLUSIONS: The overall health care costs of home oxygen therapy are similar to the cost required by patients with chronic obstructive pulmonary disease remaining in waiting lists.
Assuntos
Serviços de Assistência Domiciliar/economia , Oxigenoterapia/economia , Doença Pulmonar Obstrutiva Crônica/terapia , Idoso , Análise Custo-Benefício/economia , Feminino , Custos Hospitalares , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/economia , Estudos Retrospectivos , Listas de EsperaRESUMO
The frequency of childhood deafness is estimated at 1:1,000 and at least half of these cases are genetic. Recently, mutations in the GJB2 gene have been found in a great number of familial and sporadic cases of congenital deafness in Caucasians. The most common mutation (70%) is the frameshift mutation of a single guanine in position 35 (35delG). More than 20 mutations in the GJB2 gene are associated with DFNB1, a prevalent type of autosomal recessive non-syndromic neurosensory deafness. Last year we initiated a systematic screening programme to evaluate the causes of deafness in the population of prelingually deaf children who are referred to our cochlear implant programme. All of the deaf children and their parents undergo a comprehensive medical review, directed to identify causes of acquired deafness and manifestations of syndromic hearing impairment. DNA is extracted from the blood of all of the children. The technique AS-PCR (allele-specific polymerase chain reaction) is used for the identification of the mutation 35delG. Screening for other GJB2 gene mutations is carried out by single-strand conformation polymorphisms (SSCP). Our results on the identification of DFNB1 will be presented, as well as a discussion on the implications of an aetiological diagnosis in cochlear implantation.
Assuntos
Conexinas/genética , Surdez/genética , Mutação da Fase de Leitura/genética , Criança , Aberrações Cromossômicas , Implantes Cocleares , Conexina 26 , Surdez/reabilitação , Feminino , Genes Dominantes/genética , Genes Recessivos/genética , Testes Genéticos , Humanos , Masculino , Miosinas/genéticaRESUMO
We initiated a clinical and genetic linkage study on members of a large Venezuelan family with hereditary hearing loss. A medical history and a physical examination were performed on 30 family members. Audiometry was carried out in 25 subjects, and in 2 additional children auditory brainstem responses were obtained. Additional testing (site-of-lesion, electronystagmography and computed tomography) was also obtained in a few subjects. DNA was extracted from blood samples from 25 family members. The type of deafness in this family is neurosensorial, non-syndromic and postlingual. The average age of onset of deafness is 7 years and there is a rapid progression leading to profound deafness. Deafness is possibly of cochlear origin and there is no associated vestibular pathology. Analysis of the pedigree discloses a maternal pattern of inheritance with a significant female predominance, compatible with a mutation of the mitochondrial DNA. The molecular DNA analysis for the known mitochondrial mutations are discussed.
Assuntos
DNA Mitocondrial/genética , Surdez/genética , Mutação , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Ligação Genética , Humanos , Masculino , Linhagem , VenezuelaRESUMO
El sistema para el monitoreo continuo de pacientes usado en el tomógrafo cubano de RMI Giroimag - 02 es presentado. Se detallan los métodos de obtención y procesamiento de las bioseñales así como el modo en que se establecen los sincronismos y el formato de visualización de las ondas
Abstract A Continuous monitrning system for cuban NMR Scanner Giroimag 02 is presenteei. Biosignal processing is explained and thc methods uscd for data adquisition is presenteei. Also. syncronism anel the fonnat of wave displaying are shown
Assuntos
Imageamento por Ressonância Magnética/métodos , Monitorização Fisiológica/métodos , Coração/efeitos da radiação , Pulmão/efeitos da radiaçãoRESUMO
Este trabajo ha tomado en consideración, el diagnóstico de la situación actual del manejo y disposición final de los desechos sólidos municipales y la evaluación del nivel de recuperación de algunos de los constituyentes de los desechos generados,proponiendo los autores una Metodología para Diseño, Operación, Control y Mantenimiento de Rellenos Sanitarios en Venezuela. Esta metodología puede extrapolarse a otras regiones, ajustándola a cada condición
Assuntos
Engenharia Sanitária , Resíduos Sólidos , Aterros Sanitários , Congresso , MétodosRESUMO
El objetivo del trabajo es conocer el nivel de recuperación de algunos constituyentes de los desechos generados por la actividad municipal y su influencia en la disposición final. Evaluado todo el proceso de recolección surge la necesidad de recomendar programas de concientización ciudadana para implementar sistemas de recuperación en el origen y recolección selectiva de los desechos para disminuir en forma significativa la cantidad de desechos a manejar y disponer
Assuntos
Engenharia Sanitária , Eliminação de Resíduos , CongressoRESUMO
El objetivo del trabajo es conocer la situación actual de algunos sitios de disposición final en Venezuela y su relación con el manejo de los desechos sólidos. Se seleccionaron 11 sitios en distintas ciudades del país tomando en cuenta toda la información recopilada se constató el estado de deterioro y abandono que presenta la disposición final. Se presenta la necesidad de iniciar acciones tendientes a modificar los actuales esquemas de manejo de los desechos sólidos, para planificar integralmente todas sus actividades
Assuntos
Engenharia Sanitária , Eliminação de Resíduos , CongressoRESUMO
The nuclear DNA amount and the heterochromatin content in species and hybrids of Zea were analyzed in telophase nuclei (2C) of the root apex of germinating seeds. The results revealed significant differences among taxa and also among lines and races of maize. The hybrids between Z. mays ssp. mays x Z. mays ssp. mexicana (2n=20), Z. diploperennis x Z. perennis (2n=30), and Z. diploperennis x Z.perennis (2n=40) showed DNA content intermediate between that of the parents. The number of chromosomal C-bands and the proportion of the genome comprising C-band heterochromatin were positively related to genome size. In the different lines and races of maize studied, there was a positive correlation between genome size and the interval from germination to flowering. Octoploid Z. perennis (2n=40) showed the smallest DNA content per basic genome and the smallest heterochromatic blocks, suggesting that the DNA lost by this species consisted mainly of repetitive sequences. Considering that the extant species of Zea are tetraploid (2n=20) and octoploid (2n=40) and that the ancestral diploids are extinct, any consideration of the direction (increase or decrease) of the DNA change would be entirely speculative. The extant species could be the product of natural and artificial selection acting on different genotypic and nucleotypical constitutions at the diploid and/or tetraploid levels.
RESUMO
Premeiotic colchicine treatment brings about the production of one to five quadrivalents in Zea mays ssp. mays (maize, 2n=20) and an increase in the number of quadrivalents from five to ten in Zea perennis (2n=40). The results confirm the allotetraploid nature of maize and suggest that the species possesses two homoeologous genomes (A2A2 B2B2) that fail to pair, probably due to the presence of Ph-like genes. Moreover, the autoallooctoploid nature of Zea perennis, with a genome formula A'1A'1 Aâ³1Aâ³1 C1C1 C2C2, is supported by the present results.
RESUMO
New cytological evidence supporting x = 5 as the basic chromosome number of the genus Zea has been obtained as a consequence of our analysis of the meiotic configurations of Zea mays ssp. mays, Z. diploperennis, Z. perennis and of four F1 artificial interspecific hybrids. Z. mays ssp. mays (2n = 20) presents regular meiosis with 10 bivalents (II) and is considered here as a typical allotetraploid (A2A2B2B2). In Z. diploperennis (2n = 20) 10II are formed in the majority of the cells, but the formation of 1III + 8II + 1I or 1III + 711 + 3I in 4% of the cells would indicate its segmental allotetraploid nature (A1A1B1B1). Z. perennis (2n = 40) had 5IV + 10II in 55% of the cells and would be considered as an auto-allooctoploid (A'1A'1A''1A''1C1C1C2C2). Z. diploperennis x Z. mays ssp. mays (2n = 20) presents 10II in ca. 70% of the cells and no multivalents are formed. In the two 2n = 30 hybrids (Z. mays ssp. mays x Z. perennis and Z. diploperennis x Z. perennis) the most frequent meiotic configuration was 5III + 5II + 5I and in 2n = 40 hybrid (Z. diploperennis x Z. perennis) was 5IV + 10II. Moreover, secondary association was observed in the three abovementioned tetraploid taxa (2n = 20) where one to five groups of two bivalents each at diakinesis-metaphase I was formed showing the affinities between homoeologous genomes. The results, as a whole, can be interpreed by assuming a basic x = 5 in this polyploid complex. The main previous contributions that support this working hypothesis are reviewed and its phylogenetic implications studied are discussed.
RESUMO
The frequency and types of adverse reactions (ARs) occurring in hospitalized patients receiving furosemide were surveyed prospectively in a four-year study at the José Joaquin Aquirre Hospital in Santiago, Chile. A team of clinical pharmacists and clinical pharmacologists monitored 533 patients receiving furosemide and recorded patient characteristics, laboratory test results, drugs administered, and suspected ARs. Definite or probably furosemide-induced ARs were detected in 220 (39.8%) patients. No ARs were fatal but 7.6% of patients, all having cirrhosis of the liver, had severe ARs. Of the ARs recorded, 95.2% were dose-related. The most common ARs were electrolyte disturbances (23.5% of patients), extracellular volume depletion (9.0% of patients) and hepatic comma (3.6% of patients). Total and daily furosemide doses, lengthened hospitalization and hepatic disease were significantly associated with the frequency of ARs (p less than 0.001). The dosage of furosemide did not account for the increased frequency of ARs in patients with hepatic disease. The frequency of hypokalemia was not reduced significantly when furosemide was administered with potassium chloride or potassium-sparing diuretics (p less than 0.05). The frequency of severe furosemide-induced ARs is low, but ARs are more common in patients with cirrhosis of the liver. These patients should be closely monitored for furosemide-induced ARs.