THE PROSPECT OF BIOGAS AMONG SMALL-HOLDER DAIRY GOAT FARMERS IN THE ULUGURU MOUNTAINS, TANZANIA

Biogas can be a clean cooking alternative where biomass is the dominant source of cooking energy and where feedstock for anaerobic digestion is available. By substituting woody biomass for energy, biogas may reduce local deforestation. Tanzania has more than 15.6 million goats. Dairy goats of different breeds are found in the mid- to high altitudes of the country. Population density has made firewood increasingly scarce and there are few energy alternatives in mountainous areas such as in the Uluguru Mountains. In Mgeta ward, Morogoro region, introduction of Norwegian dairy goats in the 1980s has improved livelihoods in the area. In this study, goat manure was assessed as feedstock for biogas and as fertilizer. Field work among small-holder dairy goat farmers in Mgeta was conducted to measure daily manure production, and to provide a basic model for prediction of the quantity of droppings which may be collected by farmers. Biogas and fertilizer potential from goat manure was compared to cow and pig manure. Buswell’s formula was used to calculate approximate methane yield. The results show that goat manure from Mgeta can yield 167 l∙kg Volatile Solids-1 (VS). Compared with other substrates approximate methane yield can be ranked as pig > guatemala grass > cow > goat. The average goat of 25 kg in Mgeta leaves 61 kg Total Solids (TS) droppings per year. It was estimated that 15 goats capita-1 would be required to meet the total cooking energy needs of small-holder households in the study location. N:P:K content in goat manure (TS) is 2:1:1, similar to cow and pig manure. Goat droppings had to be macerated to reduce particle size for anaerobic digestion. Biogas from dairy goats could be combined with the year-round irrigated horticulture production in Mgeta. Vegetable gardens in the slope below the digesters could be fertilized by gravitation with the NH4+-rich bioslurry, to save labour and increase yields.

Between the rose and the shoulders of giants

The following are thoughts on 2 of the most well-known phrases in the English language, recognized as universal academic icons. That of Juliet Capuleto’s in Act II, scene II, “The Balcony”, in the immortal work of William shakespeare’s Romeo and Juliet about “A rose by any other name”, and “On the shoulders of giants”, traditionally attributed to Isaac Newton, the discoverer of the Mechanical Universal Laws, including that of Universal Law of Gravitation, in the 17th Century, but in reality first said by the humanistic philosopher and theologist Bernard of Chartres in the 12th Century

An updated evolutionary classification of CRISPR–Cas systems

The evolution of CRISPR–cas loci, which encode adaptive immune systems in archaea and bacteria, involves rapid changes, in particular numerous rearrangements of the locus architecture and horizontal transfer of complete loci or individual modules. These dynamics complicate straightforward phylogenetic classification, but here we present an approach combining the analysis of signature protein families and features of the architecture of cas loci that unambiguously partitions most CRISPR–cas loci into distinct classes, types and subtypes. The new classification retains the overall structure of the previous version but is expanded to now encompass two classes, five types and 16 subtypes. The relative stability of the classification suggests that the most prevalent variants of CRISPR–Cas systems are already known. However, the existence of rare, currently unclassifiable variants implies that additional types and subtypes remain to be characterized.

A gravitação da ética do cuidado na mediação : intervenção social e escolar nas escolas

Na resolução de conflitos, no incumprimento de normas e nas situações de indisciplina escolar, exigem-se mediadores e programas de mediação. Na implementação destes programas é essencial formar mediadores para intervirem em contexto socioeducativo com alunos, professores e família, sendo exigido a esses profissionais uma ética profissional mediadora. A necessidade de educar os alunos para integrarem as equipes de mediação implica a promoção de valores de convivência e uma ética do cuidado com os outros. A ética do cuidado e do encontro permite mais possibilidades de convívio e novas formas de existência humana. Procuramos interpretar os pontos de vista de alguns autores sobre a mediação (modelos e programas), destacando a educação para a tolerância, solidariedade, responsabilidade e cidadania, que são exigências da escola no âmbito da educação para os valores. A mediação contribui para resolver conflitos, melhorar a comunicação, as relações e a convivência.