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One of the main problems in current agriculture is the reduction of chemical fertilizers by replacing them with biofertilizers composed of beneficial microorganisms for soils and plants. Therefore, the present work aims to evaluate the effect of Pseudoxanthomonas indica named H32, previously isolated from healthy tomato plants rhizosphere, on the growth, development and yield of chard, carrot and radish crops. To this end, its ability to produce indoleacetic acid (IAA) was determined. In addition, its property to solubilizing insoluble phosphate in Pikovskaya-agar medium. The seeds were inoculated by soaking in a H32 cells suspension with 105 UFC/mL in 0.1 % carboxymetyl cellulose solution, for 3 h. A similar procedure using only carboxymetyl cellulose solution was done for non-inoculated seeds. All Seeds were then sown in 1 x 10 m plots. H32 was inoculated around the root of the seedlings of inoculated seeds, seven days after germination. The results showed that plants from inoculated seeds had greater humid weight, greater height, and roots with greater length and weight than plants from non-inoculated seeds (P < 0.01). The inoculation of the seeds and soil with H32 increased the yield by 19 % for radish, 88.7 % and 68.5 % for chard and carrot, respectively. These results show that Pseudoxanthomonas indica H32 has potential for use as a growth promoter in the crops studied. [ABSTRACT FROM AUTHOR]

Copyright of MESO is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La protección de los recursos hídricos a través de la implementación de procesos de tratamiento de las aguas residuales que son depositadas en estos se ha convertido en un gran reto para la región centroamericana, dado que cada vez es más notoria la eutrofización de los cuerpos de agua derivado de las descargas de agua residual con significativas concentraciones de nitrógeno y fósforo. Derivado de lo anterior, se ha estado realizando diversas investigaciones para proponer mecanismos locales que permitan reducir estos nutrientes, siendo uno de ellos la utilización de la semilla de Tamarindus índica debido a que su composición química se ha encontrado ácido glutámico lo cual según Campos y colaboradores (2003) son responsables de su capacidad de coagulación. En este estudio se analizó el desarrollo de un coagulante a base de la semilla de Tamarindus índica para evaluar su capacidad de reducción de fosfato-P y nitrato-N en aguas residuales proveniente del tratamiento secundario, obteniéndose una reducción máxima de 46.42±24.06% para el fosfato-P y de 37.87±29.61% para el nitrato-N, aplicando dosis de 120 y 95 miligramos de coagulante orgánico respectivamente. Por lo anterior la semilla de Tamarindus índica puede ser una opción para reducir el fosfato y nitrato cuando se requieran reducciones menores a 50%.

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De tiempo atrás se conoce que los fosfatos económicamente explotables en Colombia se encuentran en sucesiones sedimentarias marinas del Cretácico Superior (Cathcart y Zambrano, 1967; Mojica, 1987; Zambrano y Mojica, 1990). En el occidente de la subcuenca de Neiva del Valle Superior del Magdalena (VSM), estos niveles están restringidos al intervalo Santoniano-Maastrichtiano, representado en las formaciones Lidita Inferior, Lidita Superior y Yaguará. Los fosfatos son lateralmente discontinuos y presentan variaciones faciales en distancias cortas. El análisis facial y las correlaciones estratigráficas permitieron inferir que las facies presentes en estas unidades representan un ambiente marino muy somero desde la zona de transición con el offshore hasta el shoreface superior, incluyendo condiciones de laggon para la Formación Aico. Posiblemente, la paleotopografía y la subsidencia diferencial han afectado la continuidad lateral y el espesor de las unidades litoestratigráficas del intervalo Santoniano-Maastrichtiano, y los eventos tectónicos posteriores han modificado la distribución espacial de los depósitos de fosfatos. La falla de La Plata (Chusma) divide la zona en cuestión en dos dominios estructurales: uno localizado en el occidente, en el bloque levantado, donde afloran las rocas más antiguas del basamento pre-Cretácico, y otro dominio localizado en el oriente, en el bloque hundido, donde aflora la secuencia sedimentaria cretácica-cuaternaria característica de la subcuenca de Neiva. En el bloque hundido se encuentran pliegues importantes, como el Sinclinal de Media Luna y el Anticlinal de San Francisco en el norte, el Anticlinal de La Guagua en la parte central, y el Anticlinal de La Hocha y el Sinclinal de El Vegón en el sur. Algunos de estos pliegues están truncados por fallas regionales inversas con componente de rumbo dextral, como las fallas de La Plata (Chusma), San Francisco y Betania.

Introduction: Food grade inorganic phosphates are normally used for phosphorus (P) supplementation in diets for pigs, since the grains and by-products used in the formulation of diets do not cover the P requirements, these phosphates are normally imported having a high share of the cost within the formulation, therefore it is necessary to find a source of good quality P at a competitive price to maximize the efficiency in the use of this nutrient. Objective: To economically and productively evaluate diets made with three sources of national and imported phosphates. Methods: The study was carried out at the San Pablo Agricultural Station of the National University of Colombia, in a complete cycle pig production system. 30 pigs were taken in the lifting stage, they were administered 3 diets (Diet A: source of imported monodicalcium phosphate, diet B: source of national monodicalcium phosphate and diet C: source of national monodicalcium phosphate) for a period of 30 days, during which weekly weight, weight gain, consumption, and food conversion were measured. Results and Discussion: The productive response of pigs fed with different sources of phosphorus, under this study in terms of final weight, weight gains, consumption and feed conversion did not present a statistically significant difference (P>0.05), however, the diet B presented lower cost. per kg/feed followed by diet A and C respectively, but diet C presented a better cost-benefit since the pigs fed with this diet managed to have better weights with lower feed consumption. Conclusion: The sources of phosphorus of national origin used in this work to feed growing pigs are profitable sources that presented a lower production cost per kg of feed and that also showed similar results to the imported sources in terms of the parameters zootechnicians evaluated. [ABSTRACT FROM AUTHOR]

En caña de azúcar y sorgo azucarado el fosfato existe en formas inorgánica (soluble e insoluble) y orgánica. Los fosfatos inorgánicos solubles son un factor importante en la clarificación de los jugos de caña y sorgo sacarino, ya que participan de reacciones químicas con los iones calcio agregados formando fosfatos insolubles que son muy efectivos en remover del jugo de caña, coloides, colorantes y otras especies. En la literatura se recomiendan concentraciones de 300 mg P2O5/L en el jugo para obtener una buena clarificación. Los resultados de varios años de pruebas en la Estación Experimental Agroindustrial Obispo Colombres (EEAOC) indican una alta variabilidad de sus niveles, que van desde 100 a 700 mg P2O5/L. La alta variabilidad de la concentración de este compuesto hace que sea importante el análisis frecuente de fosfatos solubles para un control adecuado del proceso de clarificación. Se revisó el método colorimétrico empleado en la determinación, dado por ICUMSA y se realizó una simplificación en el procedimiento de filtración que hace más eficiente el uso de recursos y tiempo. Se redujo, además, el tiempo de análisis en un 60% y se validó la metodología con estas modificaciones, determinándose los límites de detección y cuantificación iguales a 4 mg P2O5/L y 10 mg P2O5/L, respectivamente. La recuperación promedio fue de 99% en un rango de trabajo comprendido entre 10 - 1000 mg P2O5/L. Se encontraron niveles de fosfatos insolubles inferiores al límite de detección en un conjunto de muestras de jugos mixtos y clarificados de buena calidad de caña de azúcar y sorgo azucarado. La incertidumbre expandida del método fue de 7,9%.

This research was carried out in the 2016-2018 period, its objective was to determine the concentrations of nitrates, phosphates and surfactants in the sub-basin of the Puyo River and their correlation with other variables and rainfall. It was monitored in 28 points: 10 in the main course and 18 of its tributaries. The areas were characterized as high, urban and low. The average showed greater concentration in nitrates at the points: Rosario Yacu, bridge of Indulama river and headwaters of the Putuimi river, phosphates in: Fatima dam, Bellavista Baja, Pambay dam, Palmas dam and Bellavista and in surfactants at dam of the Mechanics and bridge of the Indulama river. It is concluded that the average concentrations do not exceed the limits established in the regulations. [ABSTRACT FROM AUTHOR]

Ion exchange and the dissemination of agrochemicals or pollutants depend, to different extents, on the diffusion of the chemical species involved. Modeling the transport and dispersion of different substances in the soil requires the knowledge of the parameters that determine their rate of diffusion in the soil environment. The objective of this work was to determine the diffusion coefficients of phosphate and chloride anions in a Typic Haplustoll of the central region of the Province of Córdoba, Argentina, affected by different intensity of cultivation. The situations evaluated were: 1) no cultivation, (in a closed area), 2) alfalfa meadow rotating with other pastures in the last 50 years and, 3) a continuous agriculture plot, with more than 80 years of continuous agriculture (initially peanut/currently soybean). The diffusion experiments were carried out in saturated soil columns, generating flow from a soil column fertilized with the ion of interest, towards a soil column with its natural level of these ions. The diffusional transport parameter showed a high sensitivity to the soil history of use, constituting an indicator of its physical and chemical quality as a support for plant growth. The phosphate diffusion coefficient (D), in the conditions of this study, was mainly related to the bioavailability of the nutrient, defined by the concentration in the solution, which unfolds the position of the matrix/solution equilibrium towards the solid phase. The estimated average D values, for phosphates, differ significantly between the situations evaluated, decreasing as the intensity of agricultural activity increases. In the case of chlorides, no significant differrences were observed between treatments. [ABSTRACT FROM AUTHOR]

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With the purpose of correcting variables indicating organic contamination in waters for human consumption from the localities Severino, Julián and Balsa en Medio located in the microbasin of the Carrizal River (Manabí, Ecuador), depuration strategies based on zeolite filters and efficient microorganisms (EM) were evaluated. Three water sources were sampled: springs, tanks and faucets of regular consumption. Five treatments were tested: a) incubated with EM•1® at 5 mL/L and filtered in Cuban zeolite; b) incubated with EM • 1® at 5 mL/L and filtered in Ecuadorian zeolite; c) incubated with 5 mL/L; d) 10 mL/L and e) 15 mL/L of autochthonous microorganisms, respectively. A randomized block experimental design was used, with four repetitions. The comparison of treatments was performed by orthogonal contrasts. The variables evaluated were pH, biological oxygen demand, nitrites and phosphates. It was determined that, regardless of the location and source of treated water, the application of doses of 15 mL/L of autochthonous microorganisms and the filtration with zeolite + efficient microorganisms (EM•1®), induced significant corrections in the variables biological oxygen demand (BOD5), nitrites and pH. With the exception of the BOD5, the purification treatments reduced the levels of organic components of the waters of the localities Severino, Julian and Balsa en Medio to values acceptable for the quality regulations of drinking water and freshwater bodies in force in Ecuador. The application of autochthonous microorganisms represents a viable alternative for the reduction of organic pollutants in rural areas of the Carrizal River micro-basin. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciencias Agricolas is the property of University of Narino, Faculty of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mining for iron resources in the Gavà area of Catalonia occurred intermittently during the Iberian and Roman epochs, the Middle Ages, and continuing until the industrial era, as evidenced by historical and archaeological documents. Iron mining in this area could have occurred even earlier, during the Neolithic period. Iron ores were formed in two stages: (1) a regional hydrothermal alteration associated with Hercynian thrusts that produced the ankeritization of limestones within the Paleozoic series, and (2) the karstic replacement of these iron-rich carbonates during the Pliocene and Quaternary by means of supergenic fluids that produced ochres with goethite and hematite. The style of mineralization largely depends on the characteristics of the replaced protolith, and three styles of mineralization can be defined: (1)The supergenic replacement of ankeritized massive Pridolian limestones only produced local replacements that were restricted to structural or stratigraphic discontinuities, therefore, the mineralization has reduced dimensions and occurs as irregular veinlets or pipes; (2) The replacement of interbedded ankeritized limestones and pyrite-bearing shales (Lockovian) produced massive ores in podshaped bodies rich in silica impurities derived from the altered shales; and (3) The replacement of carbonates overthrust by pyrite- and phosphate-rich shales favored the formation of massive stratabound deposits, which are the largest and highest grade deposits in the study area, and may be locally enriched in minerals of the alunite supergroup and Ca- and Fe-rich phosphates. Outcrops of all of these styles of mineralization were mined by the Iberian cultures, during the roman period and in the Middle Ages, taking advantage of the relatively high metallurgical quality of the ores. Therefore, the exploitation during these epochs was artisanal by means of trenches or small pits. In contrast, during the industrial era only the massive stratabound deposits were exploited in open pits and underground galleries. [ABSTRACT FROM AUTHOR]

Copyright of MESO is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phosphorus fixation in tropical soils may decrease under no-till. In this case, P fertilizer could be surface-spread, which would improve farm operations by decreasing the time spend in reloading the planter with fertilizers. In the long term, less soluble P sources could be viable. In this experiment, the effect of surface-broadcast P fertilization with both soluble and reactive phosphates on soil P forms and availability to soybean was studied with or without fertilization with soluble P in the planting furrow in a long-term experiment in which soybean was grown in rotation with Ruzigrass (Brachiaria ruziziensis). No P or 80 kg ha-1 of P2O5 in the form of triple superphosphate or Arad reactive rock phosphate was applied on the surface of a soil with variable P fertilization history. Soil samples were taken to a depth of 60 cm and soil P was fractionated. Soybean was grown with 0, 30, and 60 kg ha-1 of P2O5 in the form of triple phosphate applied in the seed furrow. Both fertilizers applied increased available P in the uppermost soil layers and the moderately labile organic and inorganic forms of P in the soil profile, probably as result of root decay. Soybean responded to phosphates applied on the soil surface or in the seed furrow; however, application of soluble P in the seed furrow should not be discarded. In tropical soils with a history of P fertilization, soluble P sources may be substituted for natural reactive phosphates broadcast on the surface. The planting operation may be facilitated through reduction in the rate of P applied in the planting furrow in relation to the rates currently applied.

Copyright of MESO is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geominas is the property of FUNDA-GEOMINAS. (Fundacion de Egresados d Amigos de la Escuela de Ingenieria Geologica y de Minas) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Para evaluar el efecto medioambiental de la actividad agraria, el Gobierno de Navarra dispone de una red de cuencas experimentales donde se registran –en forma continua– datos hidrológicos y meteorológicos y de calidad de las aguas. En este artículo se reseña los resultados obtenidos –luego de cerca de 15 años de registros– en dos cuencas cerealistas –La Tejería y Latxaga– y una ganadera-forestal con una sub-cuenca casi enteramente forestal –Oskotz–, en cuanto a precipitación, escorrentía y exportación de sedimentos, nitratos y fosfatos. Se analiza tanto la variabilidad interanual como la espacial (o intercuencas) del proceso de exportación y sus implicaciones en la calidad del agua y en el ecosistema local. Aunque las lluvias estivales son las potencialmente más erosivas, el mayor registro de sedimentos en todas las cuencas se produce en invierno. Esto, se atribuye al alto contenido de humedad de los suelos en esta época, lo cual facilita la generación de escorrentía. Cuencas cerealistas, aparentemente, similares presentan marcadas diferencias en exportación de sedimentos: en La Tejería, la producción anual media es de 1800 kg/ha año, mientras que en Latxaga alcanza sólo 450 kg/ha año. Las diferencias morfológicas, topográficas y de cobertura vegetal de los cauces entre ambas cuencas explicarían –en gran parte– estas discrepancias. En Oskotz, los valores son normalmente inferiores a los registrados en cuencas cerealistas, pero a veces superiores a los de Latxaga, dependiendo del manejo forestal que se haya hecho. La calidad del agua se ve seriamente afectada en La Tejería por la polución con nitratos, siempre superior a valores críticos. En Latxaga, en cambio, la contaminación por nitrato es mucho menor. La contaminación por fosfatos supera, en ambas cuencas cerealistas, los umbrales de tolerancia. La actividad ganadera genera, en Oskotz, insospechados niveles de fosfatos, muy superiores a los registrados en las cuencas cerealistas.

Objetivando-se avaliar diferentes fontes, doses e métodos de aplicação de fósforo na recuperação da Brachiaria decumbens, um experimento foi conduzido na Fazenda Caminho das Pedras, município de Uberlândia-MG, em Latossolo Vermelho distrófico, textura média, entre novembro de 2003 e abril de 2004. Os tratamentos constaram de três fontes de fósforo (Superfosfato Triplo, Termofosfato magnesiano e hiperfosfato de Gafsa) nas dosagens de 0; 50; 100 e 150 kg ha-1 de P2O5, com manejo incorporado e não incorporado, em três repetições, no delineamento de blocos casualizados. Foram utilizadas parcelas de 2,0 x 5,0 m, as quais foram adubadas uniformemente com 330 kg ha-1 de N e 220 kg ha-1 K2O, na forma de uréia + sulfato de amônio e cloreto de potássio, respectivamente. Foi avaliada a produtividade da Brachiaria em três cortes da parte aérea, em um intervalo de 30 dias entre os cortes. A aplicação de fósforo com diferentes fontes e doses promoveu incremento na produtividade da Brachiaria, porém não houve diferença comparando-se os métodos de aplicação. A maior resposta foi obtida com 150 kg ha-1 de P2O5, na forma de superfosfato triplo com produtividade média de 2997 kg ha-1 de MS por corte, e a menor produtividade ocorreu no tratamento com 50 kg ha-1 de P2O5 na forma de hiperfosfato de Gafsa. Houve aumento na porcentagem do fósforo foliar e do fósforo no solo, com aumento da dose em todas as fontes, em ambos extratores. Na avaliação dos extratores, o Mehlich-1 apresentou maior extração na fonte hiperfosfato de Gafsa, contrariando os resultados de produção.The objective of this work was to evaluate different sources, doses and methods of phosphorus application in the recovery of Brachiaria decumbens. An experiment was installed on the "Caminho das Pedras" Farm, in Uberlândia-MG, in Acroustox soil, medium texture, between November 2003 and April 2004. The treatments were three phosphorus sources (Triple Superphosphate, magnesium Thermophosphate and Gafsa hiperphosphate) in the doses of 0; 50; 100, and 150 kg ha-1 of P2O5, incorporating or not incorporating, in three repetitions, in a randomized blocks experimental design. The plots were of 2.0 x 5.0 m, that were fertilizer evenly with 330 kg ha-1 of N and 220 kg ha-1 K2O, using urea + ammonium sulphate and potassium chloride, respectively as fertilizer sources. The productivity of Brachiaria was evaluated in three cuts of the shoot, in an interval of 30 days between cuts. Phosphorus application with different sources and doses promoted increment in the dry matter production of Brachiaria, however, there was no significant difference in production between application methods. The greatest dry matter productivity was obtained with 150 kg ha-1 of P2O5 using triple superphosphate with an average productivity of 2997 kg ha-1 of dry matter per cut. The smallest productivity was obtained applying 50 kg ha-1 of P2O5 using the Gafsa hiperphosphate. With increased phosphorus doses, to all the sources, there was increased phosphorus in the leaf and in the soil, to both extractors. In the extractors evaluation, Mehlich-1 presented highest extraction for the source Gafsa hiperphosphate, not corroborating with the production results.

En Colombia son escasos los estudios biogeoquímicos en quebradas naturales. Por esa razón se midieron varios parámetros físico-químicos y las concentraciones de carbono orgánico disuelto, nitrógeno total, fósforo total, cloruros y sulfatos para aproximarnos al papel de procesos geológicos, atmosféricos y biológicos en las quebradas de la Isla Gorgona en periodos de baja y alta precipitación durante 2008. Las aguas superficiales son prístinas por los bajos contenidos de nitrógeno. La litología volcánica, predominantemente basáltica e instrusiva ultramáfica, posiblemente determina la ocurrencia de aguas salinas (conductividad > 500 µMhos/cm), neutro-alcalinas (pH < 8,5) y ricas en fósforo total (< 200 µg/l). Los aerosoles marinos son los posibles responsables de una alta concentración de cloruros (> 2 mg/l). La concentración de carbono orgánico disuelto fue mayor en bosques maduros (> 60 mg/l) que en secundarios y rastrojos (< 60 mg/l). La baja concentración de sulfatos sugiere que no hay aportes atmosféricos desde fuentes industriales o volcánicas, aunque existen emisiones submarinas de gases en La Azufrada. El disturbio hidrológico alteró la concentración de los elementos dependiendo de su naturaleza y de las características de las cuencas.Biogeochemical studies in Colombian streams are scarce, for this reason I measured several physico-chemical variables, along with total dissolved organic carbon, total nitrogen, total phosphorous, chloride and sulfur to determine the influence of geologic, atmospheric and biotic processes during low and high rainfall periods. Volcanic lithology (basalts and ultramafic intrusives) is seemly responsible for the occurrence of saline (conductivity > 500 µmhos/cm), neutro-alkaline (pH < 8,5) and phosphorus-rich (< 200 µg/l) waters. Marine aerosols are possibly responsible for chloride inputs (> 2 mg/l). The dissolved organic carbon was higher in mature forest (> 60 mg/l) than in secondary forests and shrublands (< 60 mg/l). The low concentration of sulfates suggests that industrial and volcanic gas emissions do not exist, although underwater gas-bubbling is noticeable at La Azufrada reef. Increased rainfall and discharge altered element concentrations depending on their nature and basin features.

Se estudió la capacidad del fosfito para suplir la necesidad de P en lechuga, tomate y banano. Se comparó la efectividad relativa del fosfito con respecto al fosfato como fuente de P vía raíz, a través del crecimiento y la absorción del elemento por los 3 cultivos, en condiciones de invernadero en soluciones nutritivas sin P, con fosfito, con fosfato y con ambos. En las mismas condiciones, pero con soluciones nutritivas sin P, se comparó el suplemento de P vía foliar a partir de 4 fuentes comerciales y 2 de calidad reactivo, una de fosfito y otra de fosfato. En el ensayo de absorción vía raíz, los resultados demuestran que el P en forma de fosfito, calidad reactivo, a la solución nutritiva, no es utilizable por la planta para llenar sus necesidades de P, y tiende a causar daño. La combinación de fosfito más fosfato vía raíz, tendió a promover una mayor absorción total de P; sin embargo, en este experimento no se pudo identificar la forma química en que se encuentra ese P dentro de la planta. En el segundo ensayo se demuestra que resulta imposible llenar las necesidades de P de un cultivo con suplemento estrictamente foliar. En condiciones de carencia del elemento vía raíz, los productos comerciales no contribuyeron al crecimiento de los cultivos; tampoco atenuaron la expresión de deficiencia del elemento, ni mejoraron la absorción de este nutrimento en el follaje, más bien, intensificaron el deterioro del follaje y la raíz. El efecto sinergístico de la aplicación vía raíz de fosfatos y fosfitos, así como la respuesta a los fosfitos foliares con un suplemento adecuado de fosfato vía raíz, ya sea aportado por una solución nutritiva en condiciones hidropónicas o por medio del suelo, merecen ser estudiados con mayor profundidad.

Bernard Pelletier (1761-1797) a pharmacist and physician, devoted his short life to the application of chemistry to practical problems of industry and national activity in France. Among them we can mention the behavior of deliquescent salts, phosphorus and its derivatives, graphite and molybdenite, platinum, copper, chlorine, gunpowder, soap, and ethers. [ABSTRACT FROM AUTHOR]

Carp (Cyprinus carpio) is produced in several countries, although its commercial value may be low, and a way of adding value is to generate meat products based on this type of meat. In the preparation of such products, the ingredients may affect their final thermal and physical properties. The aim of this study was to evaluate the influence of added water, amount of fat, phosphates and carrageenan on the quality and stability of an emulsified sausage produced with carp meat. Two successive experiments were carried out with 12 treatments, each with random designs. With the data, an analysis of variance was carried out, along with a Tukey test (p£0.05). Sausages were measured for color, texture profile (TPA), firmness when cut with a Warner-Bratzler blade, Kramer shear cell, heat penetration, water activity and losses due to cooking. Results show an increase in firmness, elasticity, and resilience with more fat and phosphates, with a lower inclusion of fat and added water; contrary to cohesiveness. Brightness values (B*) increasing when including phosphates; the use of carrageenan increased the firmness of the product and the values for b*. Thermal diffusivity fluctuated between 7.1 and 9.6'10-4m2 s-1 with the use of carrageenan, fat, and water. This indicates that sausages can be produced with better elasticity, resilience, cohesiveness, firmness, and color when including phosphates, carrageenan, pig fat, and water in their preparation. [ABSTRACT FROM AUTHOR]

Several archaeological black earth (ABE) sites occur in the Amazon region. They contain fragments of ceramic artifacts, which are very important for the archaeological purpose. In order to improve the archaeological study in the region we carried out a detailed mineralogical and chemical study of the fragments of ceramic artifacts found in the two ABE sites of Cachoeira-Porteira, in the Lower Amazon Region. Their ceramics comprise the following tempers: cauixi, cariapé, sand, sand +feldspars, crushed ceramic and so on and are composed of quartz, clay equivalent material (mainly burned kaolinite), feldspars, hematite, goethite, maghemite, phosphates, anatase, and minerals of Mn and Ba. Cauixi and cariapé, siliceous organic compounds, were found too. The mineralogical composition and the morphology of their grains indicate a saprolite (clayey material rich on quartz) derived from fine-grained felsic igneous rocks or sedimentary rocks as source material for ceramic artifacts, where silica-rich components such cauixi, cariapé and/or sand (feldspar and rock fragments) were intentionally added to them. The high content of (Al,Fe)-phosphates, amorphous to low crystalline, must be product of the contact between the clayey matrix of pottery wall and the hot aqueous solution formed during the daily cooking of animal foods (main source of phosphor). The phosphate crystallization took place during the discharge of the potteries put together with waste of organic material from animal and vegetal origin, and leaving to the formation of the ABE-soil profile.Sítios arqueológicos com Terra Preta, denominados de Terra Preta de Índio ou ainda Terra Preta Arqueológica (TPA) são muito freqüentes na Amazônia. As TPA geralmente contém fragmentos de vasos cerâmicos, por vezes abundantes, além de líticos, que são materiais de grande importância para os estudos arqueológicos. Para consubstanciar esses estudos, realizou-se pesquisas mineralógicas e químicas em fragmentos cerâmicos provenientes de dois sítios arqueológicos da região de Cachoeira-Porteira, Estado do Pará. Os fragmentos foram classificados segundo seus principais temperos em: cauixi, cariapé, areia+feldspatos e caco de vaso cerâmico. Mineralogicamente são compostos de quartzo, minerais de argila calcinados (especialmente caulinita), feldspatos (albita e microclínio), hematita, goethita, maghemita, variscita-estrengita, fosfatos amorfos, anatásio, e raramente apatita, rhabdophana e óxidos de Mn e Ba. Cauixi e cariapé são componentes orgânicos silicosos e amorfos a DRX. A composição mineralógica e a morfologia dos seus grãos indicam saprólito (material argiloso rico em quartzo) derivado de rochas ígneas félsicas de granulação fina ou rochas sedimentares ricas em argilominerais como matéria-prima dos vasos cerâmicos. Neste material argiloso cauixi, cariapé e/ou areias, ricas em sílica, foram intencionalmente adicionados. O elevado conteúdo de fosfatos de Al-Fe, amorfos ou como de baixa cristalinidade, originou-se a partir do contato entre a matriz argilosa da parede do vaso cerâmico com a solução aquosa quente durante o cozimento diário de alimentos de origem animal (principal fonte de fósforo). A cristalização dos fosfatos deve ter prosseguida mesmo depois que os vasos foram descartados, e juntos com os restos de matéria orgânica vegetal e animal incorporaram-se aos solos residuais. Participaram desta forma na formação dos solos tipo TPA.

Objetivou-se ajustar modelos biomatemáticos ao metabolismo e à cinética do fósforo e determinar a absorção real e disponibilidade biológica do fósforo, em dietas de eqüinos, contendo diferentes níveis de suplementação de fósforo do fosfato bicálcico, utilizando-se o modelo, determinístico e compartimental, adaptado de Aubert e Milhaud, em que o trato gastrintestinal, os ossos e tecidos moles, em conjunto, representaram os compartimentos, em fluxo bidirecional com o sangue. Foram utilizadas informações sobre estudo de metabolismo e cinética do P em tecidos obtidas pela técnica da diluição isotópica. Constatou-se que os níveis de P dietéticos não influenciam as trocas desse mineral entre o sangue e o trato digestivo; a deposição de P nos ossos e tecidos moles tendem a aumentar com a elevação dos níveis de P, ocorrendo o inverso com a solubilização; a absorção real, o P excretado nas fezes e o balanço de P nos ossos e tecidos moles, em eqüinos, são positivamente relacionados com os níveis de P dietéticos do fosfato bicálcico; o incremento do P em dietas suplementadas com fosfato bicálcico não interfere na disponibilidade biológica desse mineral em eqüinos.This experiment was designed to adjust the biomathematical models of the phosphorus (P) flow between the physiologic or anatomical compartments of horses and to evaluate the P absorption and availability in horses, fed diets with different P levels from dicalcium phosphate. The model, deterministic and compartimental, was adapted of Aubert and Milhaud, in which the digestive tract and the bone and soft tissues represented the compartments in bi-directional flow with the blood. The informations on metabolism and kinetic of P in tissues obtained by the isotopic dilution technique were used. It was verified that the P levels from diets don't influence the changes of P between the blood and digestive tract; the P accretion in the bones and soft tissues tend to increase with the elevation of the levels of P, happening the inverse with the P re-sorption; the true absorption and P excreted in the feces and P balance in the bone and soft tissues in horse are positively related with the P dietary levels from dicalcium phosphate; the increase of supplemental P in diets containing dicalcium phosphate does not interfere in the P biological availability in horse.

Objetivou-se estudar o fluxo de fósforo (P) entre os compartimentos fisiológicos ou anatômicos de eqüinos e avaliar a absorção e disponibilidade desse mineral com o P proveniente de diferentes fontes de fosfato: Tapira, Patos de Minas, bicálcico e farinha de ossos, utilizando-se o modelo, determinístico e compartimental, adaptado de Aubert e Milhaud. Nesse modelo, o trato gastrintestinal, os ossos e tecidos moles, em conjunto, representaram os compartimentos, em fluxo bidirecional com o sangue. Foram utilizadas informações sobre estudo de metabolismo e cinética do P em tecidos obtidas pela técnica da diluição isotópica. Constatou-se que o P excretado nas fezes e na urina e o fluxo bidirecional de P dos tecidos moles e ossos para o sangue não são influenciados pelo tipo de fonte de fósforo, quando os fosfatos Tapira, Patos de Minas, bicálcico ou farinha de ossos são adicionados às dietas de eqüinos; o fluxo de P do trato digestivo para o sangue depende do tipo de fosfato existente nas dietas, sendo maior nos fosfatos bicálcico, Patos de Minas e farinha de ossos; a disponibilidade biológica e a absorção real do fósforo nos fosfatos Patos de Minas e da farinha de ossos em dietas de eqüinos são similares à do fosfato bicálcico, constituindo esses fosfatos em fontes alternativas para suplementação dietética de fósforo em eqüinos.

El interés metropolitano por la colonia del Sáhara Español se multiplicó a finales de la década de los sesenta del siglo XX, cuando se descubrieron importantes yacimiento de fosfatos. Esto coincidió con las presiones de Naciones Unidas para completar los procesos de descolonización en África, lo que impulsó al gobierno español a iniciar la denominada política de “provincialización”. Pese al argumento de que la incorporación al territorio nacional hacía desaparecer el carácter colonial del dominio español sobre el Sáhara, la relación colonial no sólo se mantuvo sino que se intensificó. Durante la provincialización se produjo una importante penetración en las estructuras políticas y sociales locales, lo que, de facto, supuso una “segunda ocupación” del territorio. Se realizaron grandes inversiones que contribuyeron a la sedentarización de la población nativa y la llegada de población de la península, en un marco de desigualdad y fragmentación social. Estas transformaciones fueron alimentando nuevos movimientos sociales y políticos que acabaron demandando la independencia. El Estado español respondió con distintos “ensayos” políticos y legislativos. Sin embargo, las tensiones en el territorio, el final del régimen franquista, las reclamaciones marroquíes y los nuevos aires internacionales precipitaron un conflicto que, casi 40 años después, está aún sin resolver.

Se propone un mecanismo de comunicación hidráulica entre el lago y el acuífero de la ciénega de Chapala localizado en la margen oriental del mismo. Se consideran indicadores químicos como los fosfatos (fósforo total) y cloruros, incorporando aspec- tos como temperatura, conductividad eléctrica y piezometría, sobre todo por la posibilidad de que el lago (dado su continuo deterioro ambiental, disminución de volumen, incremento de nutrientes) pudiera ser considerado como área preferencial de recar- ga y por lo tanto fuente potencial de contaminación de los acuíferos de la ciénega. Las formaciones sedimentarias que subyacen al lago permiten suponer la continuidad hidráulica hacia la Ciénega. Hasta 1910, cerca del 56 % de la ciénega era ocupada por el lago. Aunque predominan materiales arcillosos, las alternancias de sedimentos de grano más grueso le dan un carácter permeable al relleno del graben que define al lago. La hipótesis de comunicación se soporta por los gradientes piezométricos, así como los de cloruros y fosfatos que indican flujos del lago hacia el acuífero. El alto contenido de arcilla en los estratos someros limita la incorporación de fosfatos de origen agrícola. Como una primera aproximación para la zona se propone un modelo funcional mixto del tipo lagos de flujo directo, basado en el modelo hidroestratigráfico del acuífero, en los principales mecanismos de recarga y en las tendencias químicas y piezométricas de la ciénega. doi: https://doi.org/10.22201/igeof.00167169p.2002.41.1.262

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