Developing agricultural solutions with smallholder farmers - How to get started with participatory approaches

Farm Management,

A generalized approach for the calculation and automation of potentiometric titrations Part 2. Redox Titrations

The very fast calculation procedure described earlier is applied to calculate the titration curves of complicated redox systems. The theory is extended slightly to cover inhomogeneous redox systems. Titrations of iodine or 2,6-dichloroindophenol with ascorbic acid are described. It is shown that correspondence between theory and practice is good as long as the relevant stability constants and redox potentials are known with sufficient accuracy

A generalized approach for the calculation and automation of potentiometric titrations Part 1. Acid-Base Titrations

Fast and accurate calculation procedures for pH and redox potentials are required for optimum control of automatic titrations. The procedure suggested is based on a three-dimensional titration curve V = f(pH, redox potential). All possible interactions between species in the solution, e.g., changes in activity coefficients and influences of redox potential on pH variations, are taken into account. The number of titrant additions can be reduced considerably without loss of precision, by using the fact that the pH of a protolyte or mixture of protolytes at some fraction titrated does not depend strongly on the actual concentration

Forage Legumes for supplementing village pigs in Lao PDR

The Lao government has placed highest priority in its rural development strategy to improving livestock production systems, given the potential of livestock production to alleviate poverty and reduce shifting cultivation. Pig rearing is a common smallholder livelihood activity in northern Laos with almost all farm households raising a few pigs. Pigs are sold to cover household expenses such as school fees and medications, and they are an asset that can be liquidated to cover expenses in emergencies. Pig production is almost invariably the domain of women, who spend 2-3 hours each day to collect and prepare feed for pigs. Recent surveys identified poorly balanced pig diets in northern Laos, particularly highlighting very low protein content, as a major contributor to the observed poor growth rates and poor reproductive performance of pigs in northern Laos, and showed that farmers who had started to supplement traditional pig diets with the forage legume Stylosanthes guianensis (Stylo) were experiencing increased animal growth rates and reduced labour requirements for feeding

Description of the Alpine Micropsectra oberaarensis sp. n. with taxonomic comments on the attenuata group (Diptera: Chironomidae)

Ahitherto unknown species in the Micropsectra attenuata group, Micropsectra oberaarensis sp. n., has recently been collected from high elevation in the Berner Alps (Switzerland).The male and pupa of the new species, and the previously unknown larva of the closely related Micropsectra seguyi Casas & Laville, are here described and diagnosed. These two species, Micropsectra attenuata Reiss and Micropsectra auvergnensis Reiss are morphologically similar as adult males, but can easily be separated in their pupal life stage. Partial COI gene sequences indicate sufficient interspecific variation to separate the morphologically two most similar species, M. oberaarensis and M. seguyi. Micropsectra davigra Gilka & Abramczuk is presented as a new junior synonymto M. pharetrophora Fittkau& Reiss and a key to males of all eight West Palaearctic species in the attenuata group is given. The diagnostic characters separating the genera Parapsectra and Krenopsectra from the attenuata group are briefly discussed

New findings and an overall assessment of Norwegian biting midges (Diptera, Ceratopogonidae)

Source at: http://www.entomologi.no/journals/nje/2022-1/pdf/nje-vol69-no1-2022-82-190-dominiak.pdfFaunistic studies on biting midges conducted mostly in South Norway between 2006 and 2020, as well as a revision of available literature, resulted in a new comprehensive checklist of the species known from mainland Norway. In total, 21 genera and 216 species of Ceratopogonidae have been registered, of which as many as 165 are with Linnaean names. For the remaining 51 species interim names are given as no existing nominal species could be assigned. Four genera, namely Ceratoculicoides Wirth & Ratanaworabhan, 1971, Monohelea Kieffer, 1917b, Phaenobezzia Haeselbarth, 1965 and Probezzia Kieffer, 1906, and 58 species are reported from Norway for the first time. Records of nine biting midge species previously mentioned from the country turned out to be uncertain and are currently treated as doubtful. In Norway, the most species-rich genera of Ceratopogonidae are: Culicoides Latreille, 1809 with 34, Forcipomyia Meigen, 1818 with 29, Dasyhelea Kieffer, 1911a with 22, Atrichopogon Kieffer, 1906 with 16, Bezzia Kieffer, 1899 with 15, and Palpomyia Meigen, 1818 with 15 reported species

Adición del Silicato de Sodio en un concreto F’c 210 kg/cm2 para mejorar el comportamiento físico y mecánico, Callao 2023

El objetivo general de la investigación es centrarse en, Analizar la adición del silicato de sodio en un concreto F’c = 210 kg/cm2 para mejorar el comportamiento físico y mecánico. Siendo de un tipo de investigación aplicada, con un nivel de investigación descriptivo, diseño experimental y enfoque de investigación cuantitativo. Se recopilaron y analizaron los resultados de los ensayos de los agregados finos y gruesos, posteriormente se realizó el diseño de la mezcla del concreto en base, de esta manera se obtuvo el diseño patrón para posteriormente adicionar silicato de sodio líquido en proporciones de 2%, 5%, 7% y 10%; se realizaron ensayos de concreto en estado fresco para obtener las variaciones en los ensayos de asentamiento y densidad, llegando a observar que a medida que aumenta las adiciones de silicato este disminuye su asentamiento y mejora su rendimiento; para los ensayos de concreto en estado endurecido se llegaron a evaluar 90 probetas a las edades de 7, 14 y 28 días, para el ensayo de compresión y tracción se observó que la adición al 7% nos da un incremento de la resistencia y que al llegar al 10% la resistencia disminuye

CHIRONOMIDAE TYPES IN THE MUSEUM OF ZOOLOGY, BERGEN

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Psyllid Resistance in the Leucaena Genus

Leucaena species varied from highly susceptible to highly resistant in their response to the psyllid insect (Heteropsylla cubana) at 2 sites, a high psyllid environment at Brisbane, Australia and a moderate psyllid environment at Los Baños, Philippines. L. leucocephala was the most susceptible species. There was considerable intraspecific variation in psyllid resistance within L. collinsii, L. diversifolia and L. pallida. Plant reponse to psyllid challenge between environments was highly correlated but not linear. The higher psyllid challenge environment at Brisbane permitted greater discrimination between species and fewer Leucaena species were ranked as psyllid resistant