Cities of North Africa experienced a long occupation up to the late 7th c. CE. Despite numerous studies on Late Antique urbanism, no systematic investigation of urban hydraulics has been carried out so far. This paper examines the hydraulic topography of three cities in the Byzantine period (ca. 6th c. CE): Leptis Magna (Tripolitania), Sbeitla (Byzacena), and Timgad (Numidia). This analysis assesses to what extent Late Antique societies managed the cities’ water supply by maintaining or transforming preexisting hydraulic networks. It considers the continuity of aqueducts and the reorganization of water networks, the state of hydraulic management and technology, and the perception of water resources. The hydraulic networks inherited from the Early Roman period were to some extent preserved, although greatly adapted to new concerns for security and new technical and environmental constraints, illustrating the resilience of Late Antique societies.

This study aimed to evaluate the fermentation profile and nutritional quality of silages composed of cactus pear and maniçoba. Two experiments were performed: the first evaluated the fermentation characteristics, chemical composition and determined the organic acids in cactus pear silages with the inclusion of five levels of maniçoba (0, 25, 50, 75 and 100%) in six opening times (1, 7, 15, 30, 60 and 90 days). The second experiment determined the nutrient intake, digestibility, water balance and nitrogen balance in Canindé goats fed diets based on cactus pear silage with the inclusion of four levels of maniçoba (25, 50, 75 and 100%), with six animals per treatment. The increase in maniçoba levels in cactus pear silage provided a linear increase in the butyric acid, dry matter (DM), ether extract, crude protein, neutral detergent fibre, acid detergent fibre, lignin, cellulose, hemicellulose, water intake via drinking fountain and metabolic water, and reduced the pH, lactic acid, acetic acid, mineral matter, total carbohydrates, non-fibrous carbohydrates, water intake via food, total water intake, water excreted in the faeces, water excreted in the urine, total water excretion and water balance. Quadratic behaviour was observed for N-NH3, DM recovery and propionic acid, with an increase in maniçoba levels in cactus pear silages. Regarding the different opening times, there was a significant effect in pH, N-NH3, acetic acid, lactic acid and butyric acid (P < 0.050). The inclusion of maniçoba in cactus pear silage improved the fermentation characteristics and nutritional quality to be used in diets for goats.

This article examines the ways in which the perception of Rio de Janeiro's drinking water contributed to shaping the city's hydric management in colonial and imperial times. Even though the general assessment of climate and vegetation changed from paradisiacal to noxious in the second half of the eighteenth century in accordance with Enlightenment ideas, this had no effect on the locals’ appreciation of the city's drinking water. The criteria for evaluating the quality and quantity of available water were based on works from classical antiquity and remained essentially unchanged from early colonial times to the end of the empire. Not even population growth and increasing susceptibility to epidemics in the nineteenth century induced the authorities to reform the water supply system, as they were confident that the city was provided with good and abundant water by virtue of its natural predisposition.

Plant invasions can have large effects on ecosystem services. Some plant invaders were introduced specifically to restore key services to ecosystems, and other invaders are having unintended, detrimental effects on services, such as the quantity and quality of water delivered, flood control, erosion control, and food production. Many ecosystem services are difficult to measure directly, and although there are extensive studies on plant invaders and ecosystem processes, a number of challenges prevent us from confidently extrapolating those processes as proxies for services. To extrapolate local, short-term measures of processes to ecosystem services, we must: (1) determine which processes are the key contributors to a service, (2) assess how multiple processes interact to provide a given service, (3) determine how vegetation types and species affect those processes, and (4) explicitly assess how ecosystem services and their controls vary over space and time, including reliance of ecosystem services on “hot spots” and “hot moments” and a minimum size of a vegetation type in the landscape. A given invader can have positive effects on some services and negative effects on others. It is important to consider that, in some systems, shifting environmental conditions may no longer support native species and that invasive species may be critical contributors to the resilience of ecosystem services.

The paper is a bibliographical and critical survey of the archaeological research on ancient Ostia and Portus in the decade 2004–2014. The first part deals with some general themes, such as cults, architectural typologies and urban history, decoration: wall-paintings, mosaics and marble, the guilds and their seats, trades, etc. The second part is a survey of individual monuments and buildings which have been the subject of recent excavations and interpretations. The critical problem of late antique Ostia is treated separately, as well as the archaeology of Isola Sacra and Portus, with the Imperial harbours.

Irrigation water is produced within the irrigation subprocess of a farm. Water supply is identified for effective field water, which sets the upper bound on water available for plant use. Georgescu-Roegen process analysis concepts are merged with the neoclassical theory of cost as the underlying framework. The approach is illustrated for a permanent overhead system used in a Florida citrus grove. The marginal cost for the 2.54 centimeters application depth dominates all other depths for the higher water levels. Process analysis is an important analytical tool for increasing understanding of the features of irrigation water supply.

Despite its importance in benefit-cost analyses in the water supply, transportation, and health care sectors, there are relatively few empirical estimates of the value of travel time savings (VTT) in low-income countries, particularly in rural areas. Analysts instead often rely on a textbook “rule of thumb” of valuing time at 50% of prevailing unskilled wage rates, though these benchmarks have little empirical support in these settings. We estimate the value of travel time through the use of a repeated discrete choice stated preference exercise. We asked 325 rural households in Meru County, Kenya to rank two new hypothetical water sources against their current water source. The two new hypothetical sources were described as safe and reliable to use, but varied only in their distance from the household and the price charged per water container. Results from random-parameters logit models imply an average value of travel time of 18 Ksh/hr, and generally support the 50% rule. These models produce the first individual-level VTT estimates reported in a low-income setting, and indicate statistically-significant heterogeneity in VTTs, though the heterogeneity is not well correlated with observables. A latent-class approach identifies four classes of respondents: one class (about one third of respondents) values time very highly (49 Ksh/hr), one poorer group values time hardly at all (less than 1 Ksh/hr), and two groups value time at approximately 9 Ksh/hr.