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The stringent response exerted by (p)ppGpp and RNA-polymerase binding protein DksA regulates gene expression in diverse bacterial species. To control gene expression (p)ppGpp, synthesized by enzymes RelA and SpoT, interacts with two sites within the RNA polymerase; site 1, located in the interphase between subunits β' and ω (rpoZ), and site 2 located in the secondary channel that is dependent on DksA protein. In Escherichia coli, inactivation of dksA results in a reduced sigma factor RpoS expression. In Azotobacter vinelandii the synthesis of polyhydroxybutyrate (PHB) is under RpoS regulation. In this study, we found that the inactivation of relA or dksA, but not rpoZ, resulted in a negative effect on PHB synthesis. We also found that the dksA, but not the relA mutation reduced both rpoS transcription and RpoS protein levels, implying that (p)ppGpp and DksA control PHB synthesis through different mechanisms. Interestingly, despite expressing rpoS from a constitutive promoter in the dksA mutant, PHB synthesis was not restored to wild type levels. A transcriptomic analysis in the dksA mutant, revealed downregulation of genes encoding enzymes needed for the synthesis of acetyl-CoA, the precursor substrate for PHB synthesis. Together, these data indicate that DksA is required for optimal expression of RpoS which in turn activates transcription of genes for PHB synthesis. Additionally, DksA is required for optimal transcription of genes responsible for the synthesis of precursors for PHB synthesis. [ABSTRACT FROM AUTHOR]

In several Gram‐negative bacteria, the general stress response is mediated by the alternative sigma factor RpoS, a subunit of RNA polymerase that confers promoter specificity. In Escherichia coli, regulation of protein levels of RpoS involves the adaptor protein RssB, which binds RpoS for presenting it to the ClpXP protease for its degradation. However, in species from the Pseudomonadaceae family, RpoS is also degraded by ClpXP, but an adaptor has not been experimentally demonstrated. Here, we investigated the role of an E. coli RssB‐like protein in two representative Pseudomonadaceae species such as Azotobacter vinelandii and Pseudomonas aeruginosa. In these bacteria, inactivation of the rssB gene increased the levels and stability of RpoS during exponential growth. Downstream of rssB lies a gene that encodes a protein annotated as an anti‐sigma factor antagonist (rssC). However, inactivation of rssC in both A. vinelandii and P. aeruginosa also increased the RpoS protein levels, suggesting that RssB and RssC work together to control RpoS degradation. Furthermore, we identified an in vivo interaction between RssB and RpoS only in the presence of RssC using a bacterial three‐hybrid system. We propose that both RssB and RssC are necessary for the ClpXP‐dependent RpoS degradation during exponential growth in two species of the Pseudomonadaceae family. [ABSTRACT FROM AUTHOR]

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A significant body of research has analyzed the socioeconomic determinants of ethical consumption, nevertheless, most of those studies have been conducted in high-income countries. With data from a survey with national representation (n = 11,526), this study aimed at analyzing the socioeconomic factors shaping decisions of ethical consumption in Ecuador, a middle-income country, where agroecological production has been proposed as a strategy to reduce rural poverty while promoting sustainable agriculture. Price is the principal purchasing criterion for 78% of the households in the sample, while ecological/organic label and support to local farmers account for 11 and 3% of the sample, respectively. Brand is the principal buying criterion for 8% of the sample. Consistent with prior research, the results of a multinomial probit regression show that ecological consumers are statistically likely to be wealthier and more educated than their price-driven counterparts. Contrary to the findings of previous research in Ecuador, ecological consumers do exhibit environmental awareness. Those with support to local producers as their main purchasing driver are also featured by high levels of wealth and education, nevertheless, they are not as concerned about the environment as their ecological counterparts. The implications of these findings for policy are explored in the Discussion section. [ABSTRACT FROM AUTHOR]

Bacteria have a mechanism to rescue stalled ribosomes known as trans -translation consisting of SsrA, a transfer-messenger RNA (tmRNA), and the small protein SmpB. Other alternative rescue mechanisms mediated by ArfA and ArfB proteins are present only in some species. Ribosome rescue mechanisms also play a role in tolerance to antibiotics and various stresses such as heat. This study shows that the genome of the soil bacterium A. vinelandii harbours genes encoding for tmRNA, SmpB, two paralogs of ArfA (arfA1 and arfA2), and ArfB. A number of mutant strains carrying mutations in the ssrA, arfA1, arfA2 , and arfB genes were constructed and tested for their growth and susceptibility to heat and the antibiotic tetracycline. We found that the inactivation of both ssrA and one or the two arfA genes was detrimental to growth and caused a higher susceptibility to heat and to the antibiotic tetracycline. Interestingly, the arfB mutant strain was unable to grow after 2 h of incubation at 45°C. Inactivation of arfB in the ssrA-arfA1-arfA2 strain caused a lethal phenotype since the quadruple mutant could not be isolated. Taken together, our data suggest that both arfA1 and arfA2 , as well as arfB , are functional as back up mechanisms, and that the ArfB pathway has an essential role that confers A. vinelandii resistance to high temperatures. [ABSTRACT FROM AUTHOR]

This paper analyzes the socioeconomic factors influencing crop diversity and the likelihood of adopting monocropping as among rural households in the Esmeraldas province. With data of a household survey (n=226) conducted in October 2020 and by means of multivariate analysis techniques, it was possible determine that households with heads holding a university degree, receive non-farm income, are not recipients of the Bono de Desarrollo Humano and spend more on agricultural inputs have lower crop diversity in their farms. In terms of adoption of monocropping, households with higher endowments of education, that own larger farms, spend more on agricultural inputs and have been granted with credit are more likely to adopt monocropping as a production system. The implications of this findings for policy are discussed in the conclusion section. [ABSTRACT FROM AUTHOR]

This paper analyzes the land use patterns of mestizo-colonists and indigenous populations in the Ecuadorian Amazon. With data from a household survey conducted in colonist, Kichwa and Shuar communities in the Pastaza province, Ecuador, we determined that, as expected, colonists mostly engage in commercial agriculture and cattle ranching. There are substantial differences in land use patterns of both indigenous groups under study. Like colonists, the Shuar engage in produce cash crops and cattle, whereas the Kichwa almost exclusively engage in subsistence farming. Such different patterns appear to be related to local conditions, migratory and settlement patterns and the degree of exposure to the market economy. Beyond this, the results presented here indicate that, contrary to the general wisdom, the livelihood strategies and land use patterns of indigenous peoples do not necessarily differ from those adopted by indigenous peoples. [ABSTRACT FROM AUTHOR]

This paper analyzes the socioeconomic determinants of consumption of wild fish among the Kichwa and Shuar indigenous peoples in the Ecuadorian Amazon. The results of a random-effect linear model show that the consumption of wild fish is higher for households with younger heads that do not have off-farm work and reside far from urban centers, in communities with low population densities. Although various actors promoting aquaculture in the region often claim that it helps to relieve the pressure on wild fish stocks, no statistically significant effect of the consumption of cultivated fish on the consumption of wild fish could be shown. Thus, our analysis suggests that public policies and development interventions which increase access to off-farm employment can both improve local livelihoods and conserve biodiversity, but that the same affirmation cannot be made for the promotion of aquaculture. [ABSTRACT FROM AUTHOR]

With data from a survey conducted in April-May 2017 among the costumers of farmers’ markets, we analyzed the motivations for the consumption of agroecological foodstuffs in Quito, Ecuador. The results reveal that agroecological consumers substantially differ from the rest of the population in terms of education and income. The principal motivations to buy in agroecological farmers’ markets is that agroecological produce is perceived as healthier than conventionally produced food. On the other hand, environmental concern is the least important motivation to consume agroecological food. Additionally, the results of a linear regression model show that educated individuals with higher incomes that belong to a social/environmental are those who spend the most on agroecological products. [ABSTRACT FROM AUTHOR]

This paper compares land use patterns of mestizo colonists and indigenous populations in the central Ecuadorian Amazon, based on data from a household survey covering mestizo colonist, Kichwa and Shuar households. As expected, colonists mostly engage in commercial agriculture and cattle ranching, but there are substantial differences in land use patterns between the Shuar and the Kichwa. The Shuar engage in cash cropping and cattle ranching, and on average, devote even more land to agricultural uses than mestizo colonists in this sample. In contrast, the Kichwa engage more in subsistence crop production and less in commercial agriculture. Such different patterns appear related to local conditions, earlier migratory and settlement patterns, and the level of exposure to markets. The implications of this for policy are explored in the conclusions. [ABSTRACT FROM AUTHOR]

Knowledge of the driving forces behind indigenous participation in the market is essential for practitioners intending to integrate conservation and development policies in indigenous territories. Nevertheless, empirical research on the determinants of market integration among indigenous peoples is still scarce. This article uses household survey data and multivariate techniques to examine the drivers of market integration among indigenous groups in the Ecuadorian Amazon. We use multiple measures of market integration, including the sale of crops, timber, and wildlife; the use of credit; and participation in wage labor. The results show that the way in which indigenous peoples integrate into the market depends on their endowments of human, financial, and physical capital. More educated households are able to engage in commercial agriculture and nonagricultural wage work, whereas uneducated poor households in communities in conflict with outsiders are pushed to engage in poorly paid agricultural wage work and (often illegal) timber operations. [ABSTRACT FROM PUBLISHER]

Este artículo analiza los determinantes de la participación en el empleo no agrícola y de los ingresos no agrícolas en el Ecuador. Los resultados obtenidos con el método de estimación en dos etapas de Dubin y McFadden muestran que las mujeres son más propensas que los hombres a dedicarse al autoempleo no agrícola pero ganan mucho menos que los hombres empleados en el sector no agrícola. El empleo asalariado no agrícola es una opción común entre las personas más instruidas provenientes de hogares sin tierras, mientras que el empleo asalariado agrícola parece ser la única fuente de empleo para las personas que carecen de tierras e instrucción. La participación en el trabajo no agrícola es más probable en áreas situadas cerca de ciudades medianas con economías dinámicas. Finalmente, se observan diferencias regionales en los patrones de empleo que parecen estar relacionadas con la disponibilidad y la calidad de la tierra. [ABSTRACT FROM AUTHOR]

Off-farm employment in rural households has been cited in the literature as a potentially ideal alternative to reduce forest clearing and pressure on natural resources, since it provides income while at the same time taking household labor away from the farm. Nonetheless, empirical research on the relationship between off-farm work and natural resource use is still scarce. This paper examines the impact of off-farm work on forest clearing, logging, hunting, and fishing among both migrant colonists and indigenous populations in the Ecuadorian Amazon. In contrast to prior research, we use an instrumental variable approach to control for the potential endogeneity of off-farm work with respect to natural resource use. The results indicate that the higher the number of days worked off-farm at the household level, the lower the forest clearing. On the other hand, the number of days worked off-farm has no effect on logging, hunting, and fishing. The implications of this for sustainable development and conservation are explored in the conclusion section. [ABSTRACT FROM AUTHOR]

With data from a household survey covering migrant settlers and indigenous (Kichwa) communities in the Sumaco Biosphere Reserve (SBR), this study analyses the drivers of agricultural diversification/specialisation, focusing on the role of ethnicity and the livelihood strategies (LS) they follow. Data were collected using the Poverty and Environment Network methodology of the Center for International Forestry Research (CIFOR-PEN). In order to establish the drivers of agricultural diversification, the number of crops and the Shannon index of crops areas were used as the dependent variables in ordinary least square (OLS) models, while a multinomial logit model (MLM) was used to assess a household’s degree of diversification. The results of the OLS regression provides evidence supporting the notion that households, with Livestock-based and Wage-based livelihood strategies (LS) are less diversified and more specialized than households with Crop-based LS. Ethnicity has a positive and significant effect on agricultural diversification, with Kichwa farms more diversified than those of their migrant colonist counterparts. The results of the multinomial logit model (MLM) show that large Kichwa households, with Crop-based and Forest-based LS are more likely to adopt a highly diversified agricultural strategy. Based on these findings, we recommend a redirection of agricultural incentives, towards the adoption of diversified agricultural systems, as a strategy to promote more sustainable production systems in the Ecuadorian Amazon Region. [ABSTRACT FROM AUTHOR]