Adaptation of a cold vapour mercury analyser to flow injection analysis

Minor modifications to a Coleman MAS-50A Mercury Analyser System allowed the determination of mercury by flow injection analysis. Using sample volumes of 600 μl it was possible to analyse up to 120 samples per hour, with a detection limit of 0.2 μg. l-1 (120 pg) of mercury. The authors also report on a simple digestion procedure which replaces the time- and reagent-consuming EPA procedure, when the sample content permits

Phosphogypsum applied in surface and mixed at soil on hydraulic conductivity, pH and leaching of sodium of one saline sodic soil

Samples of a saline-sodic soil (of the Irrigated Perimeter of São Gonçalo, Souza towm, Paraiba State - Brazil) that has 61.25 me/100 of exchangeable sodium, were collected at depth 0-30 cm and phosphogypsum was applied in two levels (50% and 100% of the gypsum requirement - GR of the soil). The study v;as realized with the soil put in column of paltic tuble of 40 cm of tall and 5 cm of diametr. Both the quantities of the phosphogypsum (31 g (level-50% GR) and 62 g (level-100% GR)) were applied in the surface of the soil and too incorporated at depth 0-15 in such column. The water volume applied was 314 me and the time for star and the finish the leaching was read for to evaluate the hydraulic conductivity. In the end of the leaching each column was dismonted and divided in six parts of 5 cm that were made saturation extracts (1:5) of where were determinated pH, electric conductivity, soluble sodium content and the remaining sodium percentage (RSP). The data evidencied positive effects of the phosphogypsum on hydraulic conductivity of the soil, especially when the chemical corretive was incorporeted at 15 cm under surface of the soil. The hydraulic conductivity (k) valours showed that the less level (50% GR) was more efficient than great level (100% GR of the soil). The data of k for the phosphogypsum incorporated were 2.45 cm/h (level-50% GR) and 1.41 cm/h to level 100% of the gypsum requirement of the soil. In spite the chemistry aspects the electric conductivity data, soluble sodium contents and calours of remaining sodium percentage (RSP) of each interval of 5 cm of the columns , indicated that the phosphogypsum were more efficient in the displacement of exchangeable sodium when it was appliaed in the susrface of the soil. This way the chemical corretive showed to exercise differenced behaviour on physical and chemical properties of the soil alike its way of applications at soil.O trabalho foi realizado com amostras de um solo salino sódico do Perímetro Irrigado de São Gonçalo - Souza-PB, coletadas a 30 cm de profundidade. As amostras foram acondicionadas em tubos de polietileno com 5 cm de diâmetro e 40 cm de altura, com capacidade para um quilo de terra. Em função do teor de sódio trocável determinou-se a necessidade de gesso e foram aplicadas 32 g (dose-1) e 64 g (dose-2) de fosfogesso da Ultrafértil na superfície e incorporadas de 0 a 15 cm de superfície. Essas doses correponderam a 50 e 100% da exigência máxima de gesso pelo solo. Em seguida aplicou-se água correspondente ao volume de poros, registrou-se o tempo inicial e final de lixiviação e o volume drenado nesse período para o cálculo da condutividade hidraulica. Após cessar a lixiviação as colunas foram desmontadas e divididas em seis amostras de 5 cm, de onde determinou-se o pH, condutividade elétrica, teor de sódio solúvel do extrato de saturação 1:5 e a percentagem de sódio remanescente. Os resultados evidenciaram efieots positivos do gesso industrial (fosfogesso ) na capacidade de transmissão de água,especialmete quando incorporado na proporção de 50% (dose-1) da necessidade de gesso do solo. Em relação a condutividade hidráulica o fornecimento do corretivo foi .mais eficiente quando incorporado do que quando aplicado na superfície do solo. Do ponto de vista químico, os valores de condutividade elétrica, teores de sódio do extrato de saturação e percentagem de sódio remanescente de cada um dos intervalos, indica ram que o fosfogesso foi mais eficiente na lixiviação de sais quando aplicado na superfície. Pelo exposto, o modo de aplicação do fosfogesso mostrou exercer comportamento diferenciado entre as características físicas e químicas do solo, para uma única lixiviação

Transcriptome analysis of the venom gland of the Mexican scorpion Hadrurus gertschi (Arachnida: Scorpiones)

<p>Abstract</p> <p>Background</p> <p>Scorpions like other venomous animals posses a highly specialized organ that produces, secretes and disposes the venom components. In these animals, the last postabdominal segment, named telson, contains a pair of venomous glands connected to the stinger. The isolation of numerous scorpion toxins, along with cDNA-based gene cloning and, more recently, proteomic analyses have provided us with a large collection of venom components sequences. However, all of them are secreted, or at least are predicted to be secretable gene products. Therefore very little is known about the cellular processes that normally take place inside the glands for production of the venom mixture. To gain insights into the scorpion venom gland biology, we have decided to perform a transcriptomic analysis by constructing a cDNA library and conducting a random sequencing screening of the transcripts.</p> <p>Results</p> <p>From the cDNA library prepared from a single venom gland of the scorpion <it>Hadrurus gertschi</it>, 160 expressed sequence tags (ESTs) were analyzed. These transcripts were further clustered into 68 unique sequences (20 contigs and 48 singlets), with an average length of 919 bp. Half of the ESTs can be confidentially assigned as homologues of annotated gene products. Annotation of these ESTs, with the aid of Gene Ontology terms and homology to eukaryotic orthologous groups, reveals some cellular processes important for venom gland function; including high protein synthesis, tuned posttranslational processing and trafficking. Nonetheless, the main group of the identified gene products includes ESTs similar to known scorpion toxins or other previously characterized scorpion venom components, which account for nearly 60% of the identified proteins.</p> <p>Conclusion</p> <p>To the best of our knowledge this report contains the first transcriptome analysis of genes transcribed by the venomous gland of a scorpion. The data were obtained for the species <it>Hadrurus gertschi</it>, belonging to the family Caraboctonidae. One hundred and sixty ESTs were analyzed, showing enrichment in genes that encode for products similar to known venom components, but also provides the first sketch of cellular components, molecular functions, biological processes and some unique sequences of the scorpion venom gland.</p

INFLU\ucaNCIA DAS CARACTER\ucdSTICAS ANAT 4MICAS E DO TEOR DE EXTRATIVOS TOTAIS DA MADEIRA DE Eucalyptus grandis W. Hill ex Maiden NA QUALIDADE DA COLAGEM

The study aimed to anatomically characterize and to quantify the total extractives in different positions of the log of Eucalyptus grandis W. Hill ex Maiden with 18 years of age and to assess their influence on the shear strength and percentage of wood failure in adhesive bonded joints with thermosetting resorcinolformaldehyde. Histological slides were prepared for an anatomical study and determined the total extractive content. The preparation of bonded joints was made according to ASTM D 2339-98(2000). It was used the correlation coefficient of Pearson, 1 % probability by t test to evaluate the correlation between the anatomical and extractives content with the quality of the glued joints. It was found that there was a correlation between the shear strength with the following characteristics: vessel diameter, wall width, length and width of the fiber, the width of the radius and total extractives content. For the percentage of wood failure, there was a correlation between this with the following characteristics: the frequency of vessels, thickness of the heat of fiber, and high frequency of lightning. Both the radial direction as in the longitudinal direction of the logs there was change in the values found for the measurement of the anatomical elements, the total amount of extractives, the shear test strength and the percentage of wood failure.O trabalho teve como objetivo caracterizar anatomicamente e quantificar os extrativos totais em diferentes posi\ue7\uf5es de toras de Eucalyptus grandis W. Hill ex Maiden com 18 anos de idade e avaliar a influ\ueancia dessas caracter\uedsticas sobre a resist\ueancia ao cisalhamento e percentagem de falhas na madeira de juntas coladas com adesivo termoendurecedor resorcinol-formalde\ueddo. Foram preparadas l\ue2minas histol\uf3gicas para o estudo anat\uf4mico e determinou-se o teor de extrativos totais. A prepara\ue7\ue3o das juntas coladas foi feita de acordo com a norma ASTM D 2339-98(2000). Utilizou-se o coeficiente de correla\ue7\ue3o de Pearson, a 1 % de probabilidade pelo teste t de Student, para avaliar as correla\ue7\uf5es existentes entre as caracter\uedsticas anat\uf4micas e teor de extrativos com a qualidade das juntas coladas. Verificou-se que houve correla\ue7\ue3o entre resist\ueancia ao cisalhamento com as seguintes caracter\uedsticas: di\ue2metro do vaso, espessura da parede, largura e comprimento da fibra, largura do raio e teor de extrativos totais. E, em rela\ue7\ue3o \ue0 percentagem de falhas na madeira, houve correla\ue7\ue3o entre esta com as seguintes caracter\uedsticas: frequ\ueancia de vasos, espessura do lume da fibra, frequ\ueancia e altura do raio. Tanto no sentido radial quanto no sentido longitudinal das toras, houve varia\ue7\ue3o dos valores encontrados para a mensura\ue7\ue3o dos elementos anat\uf4micos, quantidade de extrativos totais, resist\ueancia ao cisalhamento e percentagem de falhas na madeira

Agronomic Performance and Genetic Variability of \u3cem\u3ePanicum Maximum\u3c/em\u3e Accessions in the Cerrado of Federal District, Brazil

In the last three decades, the Brazilian Savanna (locally called Cerrado ) became the most important beef cattle production region in Brazil. Around 90% of all beef produced in the region comes from pasture-based systems. Intensively-managed and fertilised Panicum maximum pastures can be highly productive and economic. As a result, farmers are demanding new P. maximum cultivars for using in well-fertilised pastures or in crop-pasture rotation systems. This study aimed to evaluate the agronomic performance and the genetic variability of P. maximum accessions in the Brazilian Cerrado

Biofertilizers in horticultural crops

Bovine manure biofertilizers can exert physical, chemical, and biological effects on the soil and the phytoprotective, physiological, and productive actions in horticultural crops. The literature review was performed to compile information on the production, uses, and effects of bovine manure biofertilizers on soil properties and plants. Biofertilizers are produced by organic components, minerals, and inoculants. Among the organic sources, the bovine manure is the most used. The fermentation of the bovine manure in water constitutes the Vairo biofertilizer, the most employed in Brazilian horticulture. With the chemical enrichment of this preparation came the Supermagro, Agrobio, and Agrobom biofertilizers. In the soil, it can act in the improvement of soil fertility, physical properties, and in the diversity and abundance of the biota. Also, it can act in control of pests and diseases, leaf composition concerning macro and micronutrients, and in the production and post-harvest quality of horticultural crops. Therefore, this review describes the preparation, chemical composition, and utilization of bovine manure biofertilizers in both soil and plants, offering perspectives of research on the formulations, application, and effects of these inputs on horticultural species.Bovine manure biofertilizers can exert physical, chemical, and biological effects on the soil and the phytoprotective, physiological, and productive actions in horticultural crops. The literature review was performed to compile information on the production, uses, and effects of bovine manure biofertilizers on soil properties and plants. Biofertilizers are produced by organic components, minerals, and inoculants. Among the organic sources, the bovine manure is the most used. The fermentation of the bovine manure in water constitutes the Vairo biofertilizer, the most employed in Brazilian horticulture. With the chemical enrichment of this preparation came the Supermagro, Agrobio, and Agrobom biofertilizers. In the soil, it can act in the improvement of soil fertility, physical properties, and in the diversity and abundance of the biota. Also, it can act in control of pests and diseases, leaf composition concerning macro and micronutrients, and in the production and post-harvest quality of horticultural crops. Therefore, this review describes the preparation, chemical composition, and utilization of bovine manure biofertilizers in both soil and plants, offering perspectives of research on the formulations, application, and effects of these inputs on horticultural species