Interdisciplinary knowledge integration through group model building: recognizing dualities and triadizing the conversation

As part of the inquiry into managing an interdisciplinary research process on adaptive water governance, we investigated the process of group model building (GMB) and, more specifically, the role of Unified Modeling Language (UML) in this process. An analysis of group interaction reveals several tensions in the process of knowledge integration, which can be grouped into three overarching dualities: ‘simplicity versus complexity’, ‘constraining versus containing’ and ‘defining versus refining’. As group members take different positions with regard to these dualities, these represent sources of tension and potential ‘stuckness’ of the GMB. Hence the question arises how the group can manage duality in ways that take the GMB beyond its opposing forces. We suggest that knowledge integration processes may benefit from early recognition of the dualities at hand and strategies aimed at creating ‘thirdness’, including some suggestions on the concrete forms such ‘thirdness’ may take.     

Gaseous emissions from weaned pigs raised on different floor systems

Gaseous emissions from agriculture contribute to a number of environmental effects. Carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) are greenhouse gases taking part to the global problem of climate change. Ammonia (NH₃) emissions are responsible of soil acidification and eutrophication and contribute also to indirect emissions of N₂O. This work evaluated the influence of the type of floor on the emissions of these gases in the raising of weaned pigs. Two trials were carried out. In the first trial, the animals were kept either on fully slatted floor or on straw-based deep litter and, in the second one, either on fully slatted floor or on sawdust-based deep litter. For each trial and on each type of floor, 2 successive batches of weaned pigs were raised without changing the litter or emptying the slurry pit between the 2 batches. The rooms were automatically ventilated to maintain a constant ambient temperature.The performance of the animals was not significantly different according to the floor type. In trial 1, the nitrogen contents of the straw deep litter (including the substrate) and slurry were respectively 276 and 389 g pig⁻¹. In trial 2, the sawdust deep litter and slurry nitrogen contents were respectively 122 and 318 g pig⁻¹.Raising pigs on straw deep litter produced proportionately around 100% more NH₃ than raising pigs on slatted floor (0.61 g NH₃-N d⁻¹ pig⁻¹ vs. 0.31 g NH₃-N d⁻¹ pig⁻¹; P < 0.05). Differences in CO₂, H₂O and CH₄ emissions were not significant between systems. Raising pigs on sawdust deep litter produced also proportionately more NH₃ (+52%; 0.55 g NH₃-N d⁻¹ pig⁻¹ vs. 0.36 g NH₃-N d⁻¹ pig⁻¹; P < 0.01) but also more CO₂ (+25%; 427 g d⁻¹ pig⁻¹ vs. 341 g d⁻¹ pig⁻¹; P < 0.001) and H₂O (+65%; 981 g d⁻¹ pig⁻¹ vs. 593 g d⁻¹ pig⁻¹; P < 0.001) and less CH₄ (−40%; 0.52 g d⁻¹ pig⁻¹ vs. 0.86 g d⁻¹ pig⁻¹; P < 0.001) than raising pigs on slatted floor. Practically no N₂O emission was observed from rooms with slatted floor while the N₂O emissions were 0.03 and 0.32 g N₂O-N d⁻¹ pig⁻¹ for the straw and sawdust deep litter respectively. The warming potential of the greenhouse gases (N₂O + CH₄), were about 22, 34 and 168 g CO₂ equivalents per day and per pig on fully slatted floor, straw or sawdust deep litter respectively.In conclusion, pollutant gas emissions from rearing of weaned pig seem lower with fully slatted plastic floor system than with deep litter systems.     

Alarming decline of freshwater trigger species in western Mediterranean key biodiversity areas

Theidentification of key biodiversity areas (KBA) was initiated by the International Union for Conservation of Nature in 2004 to overcome taxonomic biases in the selection of important areas for conservation, including freshwater ecosystems. Since then, several KBAs have been identified mainly based on the presence of trigger species (i.e., species that trigger either the vulnerability and or the irreplaceability criterion and thus identify a site as a KBA). However, to our knowledge, many of these KBAs have not been validated. Therefore, classical surveys of the taxa used to identify freshwater KBAs (fishes, molluscs, odonates, and aquatic plants) were conducted in Douro (Iberian Peninsula) and Sebou (Morocco) River basins in the Mediterranean Biodiversity Hotspot. Environmental DNA analyses were undertaken in the Moroccan KBAs. There was a mismatch between the supposed and actual presence of trigger species. None of the trigger species were found in 43% and 50% of all KBAs surveyed in the Douro and Sebou basins, respectively. Shortcomings of freshwater KBA identification relate to flawed or lack of distribution data for trigger species. This situation results from a misleading initial identification of KBAs based on poor (or even inaccurate) ecological information or due to increased human disturbance between initial KBA identification and the present. To improve identification of future freshwater KBAs, we suggest selecting trigger species with a more conservative approach; use of local expert knowledge and digital data (to assess habitat quality, species distribution, and potential threats); consideration of the subcatchment when delineating KBAs boundaries; thoughtful consideration of terrestrial special areas for conservation limits; and periodic field validation.     

The development of aquaculture on the northern coast of Manila Bay (Philippines): an analysis of long-term land-use changes and their causes

This study documents the event chronology and causes of land-use change in a deltaic region of the Philippines since the beginnings of aquaculture in the late nineteenth century. Satellite images and topographic maps spanning the period 1972–2013 were processed to map fishponds and the natural habitats over which they have encroached. Historical archives were consulted and interviews were conducted to understand the historical exploitation of local natural resources and the reasons behind the recorded land changes. Results showed that aquaculture developed in the late nineteenth century and expanded subsequently across the landscape under a succession of forcing factors. The global market, for example, played an early role but a number of land-use changes were also a direct response to changing environmental constraints and natural hazards. These cumulative events have promoted continuous gain in favor of aquaculture, to the detriment of other land-use options.     

Metal contamination recorded in the sediment of the semi-closed Bakar Bay (Croatia)

This study presents metal levels in the sediments of the Bakar Bay, with its main goal to evaluate recent anthropogenic influence, as well as over previous decades. Sediment profiles at 7 sampling points were taken. Chemical contents in bulk sediment were obtained using ICP, ICP-MS, and AAS methodologies, and 20 most significant elements were presented. Concentrations of selected elements were evaluated by factor statistical analyses to identify their source. Also, metal enrichment factor and geoaccumulation index were calculated, and spatial distribution maps for three sediment layers were constructed. Measured metal concentrations in sediment were compared with concentrations in other sediments from the Adriatic Sea. In addition, a set of sediment quality guidelines were also applied in order to predict the probability of adverse biological effects on the benthic community: This was found not to be very serious. Factor analysis clearly demonstrates the segregation between metals of natural origin resulted from soil and bedrock weathering (Li, Al, Cr, Sc), and with two anthropogenic sources originating from the city of Bakar and bulk cargo terminal (Hg, Pb, Zn, Ag, Sn, and Fe). Mercury (max 0.65 μg g^?1) is found to be the heaviest contaminant, followed by lead (max 71.5 μg g^?1), copper (89.3 μg g^?1), and zinc (156 μg g^?1). However, this study shows that Bakar Bay is considerably less polluted with toxic metals than it was believed.     

The effects of pesticides on greenhouse workers and their produced products

Pesticides are chemicals used in agriculture but are known to produce adverse effects on humans. In this study, blood activities of superoxide dismutase (SOD), catalase (CAT), aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transaminase, lactate dehydrogenase (LDH), and levels of malondialdhyde (MDA) were determined in 44 greenhouse workers (24 tomato workers, 20 clove workers) and in tomato (24 samples) and clove (20 samples) products. At the end of this study, blood MDA levels and activities of ALT, AST, and LDH levels in greenhouse workers were significantly increased while SOD and CAT activity levels fell significantly. Pesticide residues were not found in agricultural worker blood. Malathion residues (average 0.8?ppm) were detected in tomatoes (8 samples) in these greenhouses. Data suggest that the health of the greenhouse workers may be adversely affected by pesticides.     

Effects of Matricaria chamomilla L. on lipid peroxidation,antioxidant enzyme systems,and key liver enzymes in CCl4-treated rats

In this study, we investigated the effects of Matricaria chamomilla L. extract (MCE) on lipid peroxidation, antioxidant enzyme systems, and several liver enzymes in carbon tetrachloride (CCl₄)-treated rats. Rats were divided into five groups. The first group (control group) was fed on standard feed. The rats in the other groups (CCl₄, MCE50, MCE100, and MCE200) were injected intraperitoneally with 0.8?mL?kg^?1 CCl₄. Moreover, rats in the MCE50, MCE100, and MCE200 groups were gavaged with 50?mg?kg^?1, 100?mg?kg^?1, and 200?mg?kg^?1 MCE, respectively. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, whole blood malondialdehyde (MDA) and glutathione (GSH) levels, and erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity levels were measured after 14 days of exposure. ALT and AST in the CCl₄ group increased significantly in comparison to the control group (p?4, MCE50, MCE100, and MCE200 groups at different significance levels. In conclusion, the findings suggest that, depending on the dose administered, MCE decreases CCl₄-induced damage and consequent oxidative stress in rats; it affects the antioxidant system positively.