Strategies for reducing fumigant loss to the atmosphere

A model is developed to describe transport and loss of methyl bromide (MeBr) in soil following application as a soil fumigant. The model is used to investigate the effect of soil and management factors on MeBr volatilization. Factors studied include depth of injection, soil water content, presence or absence of tarp, depth to downward barrier, and irrigation after injection. Of these factors, the most important was irrigation after injection followed by covering with the tarp, which increased the diffusive resistance of the soil and prevented early loss of MeBr. The model offers an explanation for the apparently contradictory observations of earlier field studies of MeBr volatilization from soils under different conditions. The model was also used to calculate the concentration-time index for various management alternatives, showing that the irrigation application did not make the surface soil more difficult to fumigate, except at very early times. Therefore, irrigation shows promise for reducing fumigant loss while at the same time permitting control of target organisms during fumigation.

Regulation of Spec genes in aboral ectoderm cells of sea urchin {\it Strongylocentrotus purpuratus}

The Spec genes of the sea urchin Stronylocentrotus purpuratus serves as an excellent model for studying cell type-specific gene expression during early embryogenesis. The Spec1/Spec2 genes encode cytosolic calcium-binding proteins related to the calmodulin/troponin C/myosin light chain superfamily. Members of the Spec gene family are activated shortly after the sixth cleavage as the lineage-specific founder cells giving rise to aboral ectoderm are established, and the accumulation of the Spec mRNAs is limited exclusively to aboral ectoderm cell lineages. In this dissertation, the transcriptional regulation of the Spec genes was studied. Sequence comparisons of the Spec gene 5$\sp\prime$ flanking regions showed that a DNA block of approximately 800 bp from the 3$\sp\prime$ end of the first exon to the 5$\sp\prime$ end of a repetitive DNA element, termed RSR, was highly conserved. In Spec2a, the conserved region was a continuous stretch of DNA, but in Spec1 and Spec2c, DNA insertions interrupt the conserved sequence block and alter the relative placement of the RSR element and other 5$\sp\prime$ flanking DNA. Thus, drastic rearrangements have occurred within the putative control regions of the Spec genes. In vivo expression experiments using the sea urchin embryo gene-transfer system showed that while the 5$\sp\prime$ flanking regions of all three Spec genes conferred proper temporal activation to the reporter CAT gene, only the Spec2a 5$\sp\prime$ flanking region could restrict lacZ gene expression to aboral ectoderm cells. However, the Spec2a conserved region alone was not sufficient to confer proper spatial expression, suggesting that negative spatial elements are also associated with the proper activation of Spec2a. A major positive regulatory region, defined as the RSR enhancer, was identified between base pairs $-$631 and $-$443 on Spec2a. The RSR enhancer was essential for maximal activity and conferred preferential aboral ectoderm expression to a lacZ reporter gene. DNaseI footprinting and band-shift analysis of the RSR enhancer revealed multiple DNA-elements. One of the elements, an A/T-rich sequence called the A/T palindrome was studied in detail. This element binds a single 45-kDa nuclear protein, the A/T palindrome binding protein (A/TBP), whose DNA-binding specificity suggests a possible relationship with the bicoid-class homeodomain proteins. Mutated A/T palindromes are incapable of binding the 45-kDa protein and lower promoter activity by 8-fold. DNA-binding activity for A/TBP is low in unfertilized eggs, increases by the 16-cell stage and continues rising in blastulae. These data suggest that A/TBP plays a major role in the activation of the Spec2a gene in aboral ectoderm cells. ^

Prescriptions of Chinese medicinal herbs in Switzerland: the example of suan zao ren (Ziziphi Spinosae Semen)

Introduction According to the Swiss Health Survey 2007, 1.7% of the adult population use traditional Chinese medicine (including Chinese herbal medicine, but excluding acupuncture). In contrast to conventional drugs, that contain single chemically defined substances, prescriptions of Chinese herbs are mixtures of up to 40 ingredients (parts of plants, fungi, animal substances and minerals). Originally they were taken in the form of decoctions, but nowadays granules are more popular. Medium daily dosages of granules range between 8 to 12g. In a recent work we identified the most commonly used Chinese herbs (all ingredients are referred to as herbs for reasons of simplicity) and classical formulas (mixtures). Here we present a short overview and the example of suan zao ren (Ziziphi Spinosae Semen), which is used in the treatment of insomnia and anxiety and contains saponins that have been shown to increase sleep in animal studies. Material and Methods A random sample of 1,053 prescriptions was drawn from the database of Lian Chinaherb AG, Switzerland, and analysed according to the most frequently used individual herbs and classical formulas. Cluster analysis (Jaccard similarity coefficient, complete linkage method) was applied to identify common combinations of herbs. Results The most frequently used herbs were dang gui (Angelicae Sinensis Radix), fu ling (Poria), bai shao (Paeoniae Radix Alba), and gan cao (Glycyrrhizae Radix et Rhizoma); the most frequently used classical formulas were gui pi tang (Restore the Spleen Decoction) and xiao yao san (Rambling Powder). The average number of herbs per prescription was 12.0, and the average daily dosage of granules was 8.7g. 74.3% of the prescriptions were for female, 24.8% for male patients. Suan zao ren was present in 14.2% of all prescriptions. These prescriptions contained on average 13.7 herbs, and the daily dosage of granules was 8.9g. Suan zao ren was more frequently prescribed by practitioners of non-Asian than of Asian origin but equally often for female and male patients. Cluster analysis grouped suan zao ren with yuan zhi (Polygalae Radix), bai zi ren (Platycladi Semen), sheng di huang (Rehmanniae Radix) and dan shen (Salviae Miltiorrhizae Radix et Rhizoma). Discussion Prescriptions including suan zao ren contained on average slightly more herbs than other prescriptions. This might be due to the fact that two of the three most popular classical formulas with suan zao ren are composed of 13 and 12 herbs with the possibility of adding more ingredients when necessary. Cluster analysis resulted in the clustering of suan zao ren with other herbs of the classical formula tian wang bu xin dan (Emperor of Heaven’s Special Pill to Tonify the Heart), indicating the use of suan zao ren for the treatment of insomnia and irritability. Unfortunately, the diagnoses of the patients were unavailable and thus correlations between use of suan zao ren and diseases could not be analysed.

La educación especial y sus protagonistas : desde la recuperación democrática hasta nuestros días. La ética en la agenda

La recuperación de la democracia en diciembre de 1983, fue el inicio de una nueva etapa en la vida de la República Argentina. Sin embargo, ciclos repetidos de ilusiones y desilusiones, de incertidumbres y esperanzas, de encuentros y desencuentros, de proyectos y frustraciones, marcaron fuertemente a toda la población y a las instituciones que la representan. La educación, las escuelas y sus protagonistas no quedaron fuera de esta realidad, lo que limitó su posibilidad de mejorar la oferta educativa. Sin embargo, las fuertes experiencias cotidianas, marcaron a cada uno y a las relaciones con el otro, con los otros, con las organizaciones sociales. Se ganó algo muy importante: La vida en democracia. Pero se trastocaron valores y muchos principios éticos quedaron fuertemente mancillados. Esta es la reflexión que nos proponemos.

As entranhas da colonialidade do saber : Notas sobre a relação entre povos indígenas e Estado em contextos latino-americanos

A partir de recientes trabajos de campo dedicados a entender la relación entre las comunidades indígenas y las instituciones del Estado en Brasil y Bolivia, se intenta examinar con mayor profundidad los modos de operación, la reproducción y, en especial, la legitimación de la llamada colonialidad del poder - categoría de los estudios poscoloniales/descoloniales presentada por el sociólogo peruano Aníbal Quijano que ganó proyección dando énfasis justamente a la continuación de los patrones coloniales en la toma de decisiones, después del cierre del proceso histórico y formal del colonialismo político. Entre los distintos puntosanalizados, uno de los cuales emergen con mayor énfasis en la comprensión de la colonialidad del poder es el que oculta detrás de la idea de nación, el fundamento de los proyectos políticos que apoyan al Estado en diferentes contextos. Se entiende, por lo tanto, que sin una profunda deconstrucción (histórica, epistemológica y ontológica) de la nación, que se construyó de acuerdo a la forma establecida por el colonialismo interno y sus vínculos con el sistema-mundo occidental y capitalista dominante, los debates en torno del Estado, en las antiguas colonias europeas hoy "emancipadas" en América Latina, tienden a limitarse a los aspectos superficiales, sin tocar la lógica colonial de exclusión. Hay, todavía, experiencias protagonizadas por los pueblos indígenas de ambos países hacia la construcción de otros paradigmas de políticas públicas

Entre la universidad y la política. Algunos elementos para investigar las luchas estudiantiles de Corrientes, Rosario, Córdoba y Tucumán entre el golpe de Estado de Onganía y el de Lanusse

Con el golpe de Estado de Onganía en 1966 comenzó un intento de consolidación de un Estado Burocrático Autoritario. El gobierno de facto, cuya base social era el gran capital, impulsó reformas estructurales en la economía y las instituciones tendientes a la despolitización y la concentración del capital. Este proyecto entró en una crisis irreversible en mayo de 1969 con los hechos de masas conocidos como Rosariazo y Cordobazo. La descomposición de la dictadura llegó a su punto crítico tras el Tucumanazo y el Viborazo. Tras estos hechos Lanusse dio un golpe de Estado, promovió el GAN y la convocatoria a elecciones sin proscripciones para 1973. Se considera que a partir de 1969 se inauguró una nueva etapa en las luchas sociales en Argentina expresada en una ?nueva izquierda?, de agrupaciones revolucionarias armadas, un auge del activismo obrero y estudiantil, etc. Sin embargo, a pesar de que siempre se menciona el rol de los estudiantes del litoral y del interior en el proceso que derrotó a la dictadura, se haya ausente un estudio sistemático de las luchas del movimiento estudiantil de las regiones donde se desarrollaron los mayores enfrentamientos al régimen militar. Aquí presento algunas dimensiones para su investigación