Co-producing uncomfortable, transdisciplinary, actionable knowledges against the corporate food regime through critical science approaches.

The current corporate food regime generates some of the most challenging ecological, social, and ethical problems for humanity in its quest for sustainability and ecological justice. Different scientific disciplines have analyzed these problems in-depth, but usually from their comfort zone, i.e., without engagement with other disciplines and epistemologies. The predominance of disciplinary visions seriously limits, however, understanding the complexities of the corporate food regime, including the impacts it generates. Further, most research concerned with this food regime confronts epistemological, methodological, and political limitations to engage with the type of solutions that could lead to transitions to just sustainabilities. Here we review and integrate the findings from scientific literature focused on the ecological, social, or ethical impacts of the corporate food regime, with an emphasis on impacts that operate on a global scale. In addition, we analyze the need for critical science approaches to trigger generative processes for the co-production of uncomfortable, transdisciplinary, actionable knowledges that are fit for designing just and sustainable food regimes. Much of the evidence presented in our analysis is in tension with the interests of the corporate food regime, which fosters decision-making processes based on selective ignorance of the impacts caused by this regime. Our work provides arguments that justify the need to promote transitions to just sustainabilities in agricultural systems from multiple domains (e.g., research and development, public policies, grassroots innovations). We posit that strategies to co-design and build such transitions can emerge from the co-production of uncomfortable, transdisciplinary, actionable knowledges through critical science approaches.

Periselectivity in the aza-Diels-Alder Cycloaddition between α-Oxoketenes and N-(5-Pyrazolyl)imines: A Combined Experimental and Theoretical Study.

The thermal 6π aza-Diels-Alder cycloadditions between α-oxoketenes, in situ derived from a thermally induced Wolff rearrangement of 2-diazo-1,3-diketones, and N-(5-pyrazolyl)imines as prototypical electron-rich 2-azadienes lead to two distinct sets of products, essentially as a function of the nature of the α-oxoketenes involved. For instance, cyclic five-membered α-oxoketenes lead preferentially to spiro hydropyridin-4-ones, which involves the α-oxoketenes as the 2π partners at their C═C double bond and the N-(5-pyrazolyl)imines as the 4π partners at their 2-azadiene moiety. In contrast, other cyclic and acyclic α-oxoketenes lead preferentially to 1,3-oxazin-4-ones, which now involves the α-oxoketenes as the 4π partners at their 1-oxadiene moiety and the N-(5-pyrazolyl)imines as the 2π partners at their C═N double bond. A computational modeling study using DFT methods allowed rationalizing this change of periselectivity: the formation of spiro hydropyridin-4-ones is under thermodynamic control while the formation of 1,3-oxazin-4-ones is kinetically controlled, and slightly thermodynamically disfavored in the five-membered ring series. The competing cyclodimerization of the α-oxoketenes is also studied in detail.

Synthesis and Antifungal in Vitro Evaluation of Pyrazolo[3,4-b]pyridines Derivatives Obtained by Aza-Diels-Alder Reaction and Microwave Irradiation.

A series of pyrazolo[3,4-b]pyridines were prepared by a microwave-assisted aza-Diels-Alder reaction between pyrazolylformimidamides 1 and ß-nitrostyrenes 2 in toluene as the solvent. This procedure provides a simple one-step and environmentally friendly methodology with good yields for the synthesis of these compounds. All compounds were tested for antifungal activity against two clinically important fungi Candida albicans and Cryptococcus neoformans. Within the compounds of the series bearing a -CH3 group on the carbon C-3 of the azole ring (3a-e), the compound without a substituent on the p'-phenyl ring (3a), showed the best activity against both fungi, followed by the p'-Br-phenyl (3c). Within the compounds of the series bearing a tert-butyl group in the carbon C-3 of the azole ring (3f-j), the non-substituted p'-compound (3f) was the most active one, followed by (3h) (p'-Br substituted) that showed the best activity against both fungi. The remaining compounds of this sub-series (3g, i, j) showed similar moderate activities. The antifungal activity of the compounds of the series was found to be correlated with a higher log P and a lower dipole moment in the more active compounds.

Shifts in indigenous culture relate to forest tree diversity: a case study from the Tsimane', Bolivian Amazon.

Understanding how indigenous peoples' management practices relate to biological diversity requires addressing contemporary changes in indigenous peoples' way of life. This study explores the association between cultural change among a Bolivian Amazonian indigenous group, the Tsimane', and tree diversity in forests surrounding their villages. We interviewed 86 informants in six villages about their level of attachment to traditional Tsimane' values, our proxy for cultural change. We estimated tree diversity (Fisher's Alpha index) by inventorying trees in 48 0.1-ha plots in old-growth forests distributed in the territory of the same villages. We used multivariate models to assess the relation between cultural change and alpha tree diversity. Cultural change was associated with alpha tree diversity and the relation showed an inverted U-shape, thus suggesting that tree alpha diversity peaked in villages undergoing intermediate cultural change. Although the results do not allow for testing the direction of the relation, we propose that cultural change relates to tree diversity through the changes in practices and behaviors that affect the traditional ecological knowledge of Tsimane' communities; further research is needed to determine the causality. Our results also find support in the intermediate disturbance hypothesis, and suggest that indigenous management can be seen as an intermediate form of anthropogenic disturbance affecting forest communities in a subtle, non-destructive way.

Highly efficient and diastereoselective synthesis of new pyrazolylpyrrolizine and pyrazolylpyrrolidine derivates by a three-component domino process.

Diastereoselective reactions between 4-formylpyrazoles, N-substituted maleimides and glycine derivates led to new series of pyrazolyldipyrrolo [3,4-a:3',4'-f]pyrrolizines and pyrazolylpyrrolo[3,4-c]pyrroles in good yields. The reactions proceeded by a domino process through azomethine ylides formed in situ via a 1,3-dipolar cycloaddition reaction.

Cultural change and traditional ecological knowledge. An empirical analysis from the Tsimane' in the Bolivian Amazon.

Among the different factors associated to change in traditional ecological knowledge, the study of the relations between cultural change and traditional ecological knowledge has received scan and inadequate scholarly attention. Using data from indigenous peoples of an Amazonian society facing increasing exposure to the mainstream Bolivian society, we analyzed the relation between traditional ecological knowledge, proxied with individual plant use knowledge (n=484), and cultural change, proxied with individual- and village-level (n=47) measures of attachment to traditional beliefs and values. We found that both the individual level of detachment to traditional values and the village level of agreement in detachment to traditional values were associated with individual levels of plant use knowledge, irrespective of other proxy measures for cultural change. Because both the individual- and the village-level variables bear statistically significant associations with plant use knowledge, our results suggest that both the individual- and the supra-individual level processes of cultural change are related to the erosion of plant use knowledge. Results from our work highlight the importance of analyzing processes that happen at intermediary social units -the village in our case study- to explain changes in traditional ecological knowledge.

Are ecologically important tree species the most useful? A case study from indigenous people in the Bolivian Amazon.

Researchers have argued that indigenous peoples preferably use the most apparent plant species, particularly for medicinal uses. However, the association between the ecological importance of a species and its usefulness remains unclear. In this paper we quantify such association for six use categories (firewood, construction, materials, food, medicines and other uses). We collected data on the uses of 58 tree species, as reported by 93 informants in 22 villages in the Tsimane' territory (Bolivian Amazon). We calculated the ecological importance of the same species by deriving their importance value index (IVI) in 48 0.1-ha old-growth forest plots. Matching both data sets, we found a positive relation between the IVI of a species and its overall use value (UV) as well as with its UV for construction and materials. We found a negative relation between IVI and UV for species that were reportedly used for medicine and food uses, and no clear pattern for the other categories. We hypothesize that species used for construction or crafting purposes because of their physical properties are more easily substitutable than species used for medicinal or edible purposes because of their chemical properties.

Influence of Graphene Oxide on Mechanical Properties and Durability of Cement Mortar.

The effect of graphene oxide (GO) on the mechanical strengths and durability of cement composites was researched by preparing GO-modified cement mortars. Thermogravimetric analysis (TGA) and nuclear magnetic resonance (29Si MAS-NMR) were performed on the cement paste to evaluate the influence of GO on the hydration process and chain structure of calcium-silicate-hydrate (C-S-H) gels. TGA revealed that the high GO dosage increased the content of C-S-H by 5.46% compared with the control at 28 days. Similarly, 29Si-NMR improved the hydration degree and main chain length (MCL) in GO-modified samples at 28 days. The GO led to increases of 2.54% and 7.01% in the hydration degree and MCL, respectively, compared with the control at 28 days. These findings underscore the multifaceted role of GO in improving the mechanical properties and durability of cement composites. Mechanical strength tests, such as compressive and flexural tests, were conducted on cement mortars. The optimal dosage of GO increased the compressive strength by 9.02% after 28 days. Furthermore, the flexural strength of cement mortars with the combination of GO and superplasticizer (SP) after 28 days increased by 21.86%, compared with reference mortar. The impact of GO proved to be more pronounced and beneficial in the durability tests, suggesting that GO can enhance the microstructure through hydration products to create a dense and interconnected microstructure.

Evidence of traditional knowledge loss among a contemporary indigenous society.

As biological and linguistic diversity, the world's cultural diversity is on decline. However, to date there are no estimates of the rate at which the specific cultural traits of a group disappear, mainly because we lack empirical data to assess how the cultural traits of a given population change over time. Here we estimate changes in cultural traits associated to the traditional knowledge of wild plant uses among an Amazonian indigenous society. We collected data among 1151 Tsimane' Amerindians at two periods of time. Results show that between 2000 and 2009, Tsimane' adults experienced a net decrease in the report of plant uses ranging from 9% (for the female subsample) to 26% (for the subsample of people living close to towns), equivalent to a 1 to 3 % per year. Results from a Monte Carlo simulation show that the observed changes were not the result of randomness. Changes were more acute for men than for women and for informants living in villages close to market towns than for informants settled in remote villages. The Tsimane' could be abandoning their traditional knowledge as they perceive that this form of knowledge do not equip them well to deal with the new socio-economic and cultural conditions they face nowadays.

Two methyl 3-(1H-pyrazol-4-yl)octahydropyrrolo[3,4-c]pyrrole-1-carboxylates form different hydrogen-bonded sheets.

In the molecules of both methyl (1RS,3SR,3aRS,6aSR)-1-methyl-3-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-4,6-dioxo-5-phenyloctahydropyrrolo[3,4-c]pyrrole-1-carboxylate, C25H24N4O4, (I), and methyl (1RS,3SR,3aRS,6aSR)-5-(4-chlorophenyl)-1-methyl-3-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-4,6-dioxooctahydropyrrolo[3,4-c]pyrrole-1-carboxylate, C25H23ClN4O4, (II), the two rings of the pyrrolopyrrole fragment are both nonplanar, with conformations close to half-chair forms. The overall conformations of the molecules of (I) and (II) are very similar, apart from the orientation of the ester function. The molecules of (I) are linked into sheets by a combination of an N-H∙∙∙π(pyrrole) hydrogen bond and three independent C-H∙∙∙O hydrogen bonds. The molecules of (II) are also linked into sheets, which are generated by a combination of an N-H∙∙∙N hydrogen bond and two independent C-H∙∙∙O hydrogen bonds, weakly augmented by a C-H∙∙∙π(arene) hydrogen bond.

Secular trends on traditional ecological knowledge: An analysis of different domains of knowledge among Tsimane' men.

Empirical research provides contradictory evidence of the loss of traditional ecological knowledge across societies. Researchers have argued that culture, methodological differences, and site-specific conditions are responsible for such contradictory evidences. We advance and test a third explanation: the adaptive nature of traditional ecological knowledge systems. Specifically, we test whether different domains of traditional ecological knowledge experience different secular changes and analyze trends in the context of other changes in livelihoods. We use data collected among 651 Tsimane' men (Bolivian Amazon). Our findings indicate that different domains of knowledge follow different secular trends. Among the domains of knowledge analyzed, medicinal and wild edible knowledge appear as the most vulnerable; canoe building and firewood knowledge seem to remain constant across generations; whereas house building knowledge seems to experience a slight secular increase. Our analysis reflects on the adaptive nature of traditional ecological knowledge, highlighting how changes in this knowledge system respond to the particular needs of a society in a given point of time.

Numerical Simulation of PFRC Fracture Subjected to High Temperature by Means of a Trilinear Softening Diagram.

Fibre-reinforced concrete (FRC) has been used for decades in certain applications in the construction industry, such as tunnel linings and precast elements, but has experienced important progress in recent times, boosted by the inclusion of guidelines for its use in some national and international standards. Traditional steel fibres have been studied in depth and their performance is well-known, although in recent years new materials have been proposed as possible alternatives. Polyolefin macro-fibres, for instance, have been proven to enhance the mechanical properties of concrete and the parameters that define their behaviour (fibre length, fibre proportion or casting method, for instance) have been identified. These fibres overcome certain traditional problems related to steel fibres, such as corrosion or their interaction with magnetic fields, which can limit the use of steel in some applications. The behaviour of polyolefin fibre-reinforced concrete (PFRC) has been numerically reproduced with success through an embedded cohesive crack formulation that uses a trilinear softening diagram to describe the fracture behaviour of the material. Furthermore, concrete behaves well under high temperatures or fire events, especially when it is compared with other construction materials, but the behaviour of PFRC must be analysed if the use of these fibres is to be extended. To this end, the degradation of PFRC fracture properties has been recently experimentally analysed under a temperature range between 20 °C and 200 °C. As temperature increases, polyolefin fibres modify their mechanical properties and their shape, which reduce their performance as reinforcements of concrete. In this work, those experimental results, which include results of low (3 kg/m3) and high (10 kg/m3) proportion PFRC specimens, are used as reference to study the fracture behaviour of PFRC exposed to high temperatures from a numerical point of view. The experimental load-deflection diagrams are reproduced by modifying the trilinear diagram used in the cohesive model, which helps to understand how the trilinear diagram parameters are affected by high temperature exposure. Finally, some expressions are proposed to adapt the initial trilinear diagram (obtained with specimens not exposed to high temperature) in order to numerically reproduce the fracture behaviour of PFRC affected by high temperature exposure.

Methyl (3aRS,3cRS,6cSR,7RS,8RS,8aSR)-2,5-bis(4-chlorophenyl)-7,9-bis(1,3-diphenyl-1H-pyrazol-4-yl)-1,3,4,6-tetraoxododecahydro-1H-dipyrrolo[3,4-a:3',4'-f]pyrrolizine-3b-carboxylate dimethylformamide disolvate: a three-dimensional hydrogen-bonded framework.

The racemic title dipyrrolopyrrolizine compound crystallizes from dimethylformamide as a disolvate, C(55)H(39)Cl(2)N(7)O(6)·2C(3)H(7)NO. None of the four fused heterocyclic rings is planar; one adopts an envelope conformation, two others adopt half-chair conformations and the fourth adopts a conformation intermediate between an envelope and a half-chair. The arrangement of the ring fusions is such as to preclude the possibility of internal mirror symmetry. The three independent molecular components are weakly linked by C-H···O hydrogen bonds, and the dipyrrolopyrrolizine molecules are linked by a combination of four C-H···O and one C-H···π(arene) hydrogen bond to form a three-dimensional framework, from which the dimethylformamide solvent molecules are pendent. However, aromatic π-π stacking interactions are absent in the structure.

Effect of Sulfate Ions on Galvanized Post-Tensioned Steel Corrosion in Alkaline Solutions and the Interaction with Other Ions.

Zinc protection of galvanized steel is initially dissolved in alkaline solutions. However, a passive layer is formed over time which protects the steel from corrosion. The behavior of galvanized steel exposed to strong alkaline solutions (pH values of 12.7) with a fixed concentration of sulfate ions of 0.04 M is studied here. Electrochemical measurement techniques such as corrosion potential, linear polarization resistance and electrochemical impedance spectroscopy are used. Synergistic effects of sulfate ions are also studied together with other anions such as chloride Cl− or bicarbonate ion HCO3− and with other cations such as calcium Ca2+, ammonium NH4+ and magnesium Mg2+. The presence of sulfate ions can also depassivate the steel, leading to a corrosion current density of 0.3 µA/cm2 at the end of the test. The presence of other ions in the solution increases this effect. The increase in corrosion current density caused by cations and anions corresponds to the following orders (greater to lesser influence): NH4+ > Ca2+ > Mg2+ and HCO3− > Cl− > SO42−.

Suitability of Constitutive Models of the Structural Concrete Codes When Applied to Polyolefin Fibre Reinforced Concrete.

The use of fibres as structural reinforcement in concrete is included in standards, providing guidelines to reproduce their behaviour, which have been proven adequate when steel fibres are used. Nevertheless, in recent years new materials, such as polyolefin fibres, have undergone significant development as concrete reinforcement. This work gives insight on how suitable the constitutive models proposed by the Model Code 2010 (MC2010) are in the case of such polymer fibres. A set of numerical models has been carried out to reproduce the material behaviour proposed by the MC2010 and the approach based on the softening function proposed by the authors. The results show remarkable differences between the experimental results and the numerical simulations when the constitutive models described in the MC2010 are employed for different polyolefin fibre reinforced concrete mixes, while the material behaviour can be reproduced with greater accuracy if the softening function proposed by the authors is employed when this type of macro-polymer fibres is used. Moreover, the relatively complex behaviour of polyolefin fibre reinforced concrete may be reproduced by using such constitutive model.

Grassroots innovation for the pluriverse: evidence from Zapatismo and autonomous Zapatista education.

The social and environmental failure of successive Western development models imposed on the global South has led local communities to pursue alternatives to development. Such alternatives seek radical societal transformations that require the production of new knowledge, practices, technologies, and institutions that are effective to achieve more just and sustainable societies. We may think of such a production as innovation driven by social movements, organizations, collectives, indigenous peoples, and local communities. Innovation that is driven by such grassroots groups has been theorized in the academic literature as "grassroots innovation". However, research on alternatives to development has rarely examined innovation using grassroots innovation as an analytical framework. Here, we assess how grassroots innovation may contribute to building alternatives to development using Zapatismo in Chiapas (Mexico) as a case study. We focus on grassroots innovation in autonomous Zapatista education because this alternative to formal education plays a vital role in knowledge generation and the production of new social practices within Zapatista communities, which underpin the radical societal transformation being built by Zapatismo. We reviewed the academic literature on grassroots innovation as well as gray literature and audiovisual media on Zapatismo and autonomous Zapatista education. We also conducted ethnographic fieldwork in a Zapatista community and its school. We found innovative educational, pedagogical, and teaching-learning practices based on the (re)production of knowledge and learning, which are not limited to the classroom but linked to all the activities of Zapatistas. Our findings suggest that innovation self-realized by Zapatistas plays a key role on the everyday construction of Zapatismo. Therefore, we argue that a specific theoretical framework of grassroots innovation for the pluriverse, based on empirical work carried out in different alternatives to development, is an urgent task that will contribute to a better understanding of how such alternatives grassroots groups imagine, design, and build, particularly across the global South.

Matrix Optimization of Ultra High Performance Concrete for Improving Strength and Durability.

This paper seeks to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC). To meet this objective, concrete specimens were manufactured by using 1100 kg/m3 of binder, water/binder ratio 0.20, silica sand and last generation of superplasticizer. Silica fume, metakaolin and two types of nano silica were used for improving the performances of the concrete. Additional mixtures included 13 mm long OL steel fibers. Compressive strength, electrical resistivity, mercury intrusion porosimetry tests, and differential and thermogravimetric thermal analysis were carried out. The binary combination of nano silica and metakaolin, and the ternary combination of nano silica with metakaolin and silica fume, led to the best performances of the UHPC, both mechanical and durable performances.

Assessment of the Post-Cracking Fatigue Behavior of Steel and Polyolefin Fiber-Reinforced Concrete.

Some types of fiber-reinforced concrete (FRC) such as steel fiber-reinforced concrete (SFRC) or polyolefin fiber-reinforced concrete (PFRC) are suitable for structural uses but there is still scarce knowledge regarding their flexural fatigue behavior. This study aimed to provide some insight into the matter by carrying out flexural fatigue tests in pre-cracked notched specimens that previously reached the Service Limit State (SLS) or the Ultimate Limit State (ULS). The fatigue cycles applied between 30% and 70% of the pre-crack load at 5 Hz until the collapse of the material or until 1,000,000 cycles were reached. The results showed that the fatigue life of PFRC both at SLS or ULS was remarkably higher than the correspondent of SFRC. The fracture surface analysis carried out found a linear relation between the fibers present in the fracture surface and the number of cycles that both SFRC and PFRC could bear.

Numerical Simulation of the Fracture Behavior of High-Performance Fiber-Reinforced Concrete by Using a Cohesive Crack-Based Inverse Analysis.

Fiber-reinforced concrete (FRC) has become an alternative for structural applications due its outstanding mechanical properties. The appearance of new types of fibres and the fibre cocktails that can be configured by mixing them has created FRC that clearly exceeds the minimum mechanical properties required in the standards. Consequently, in order to take full advantage of the contribution of the fibres in construction projects, it is of interest to have constitutive models that simulate the behaviour of the materials. This study aimed to simulate the fracture behaviour of five types of FRC, three with steel fibres, one with a combination of two types of steel fibers, and one with a combination of polyolefin fibres and two types of steel fibres, by means of an inverse analysis based on the cohesive crack approach. The results of the numerical simulations defined the softening functions of each FRC formulation and have pointed out the synergies that are created through use of fibre cocktails. The information supplied can be of help to engineers in designing structures with high-performance FRC.