Amazonian Context Research Articles

Brazil nut journey under future climate change in Amazon.

Climate change is among the principal threats to global terrestrial biodiversity, especially to megadiverse ecosystems such as the Amazon rainforest. In this study, we investigate how it could affect an iconic forest species-Bertholletia excelsa-(the Brazil nut) which has values in multiple dimensions in an Amazonian context. We used an ensemble from various distribution modeling methods designed for four different climate scenarios from CMIP6 by the end of the century. Then, we simulate how spatial dynamics under climate change, including explicitly dispersal events, can affect the persistence, colonization, and potential extinction of Bertholletia excelsa in the future. Our results show that by the end of the century there would be a generalized loss of suitability on the Amazon biome, regardless of the climate scenario evaluated, which could promote a significant loss (up to 94%) of the area available for the species via extinction. Our results also show that, in the future, the species would colonize higher altitudes in search of favorable conditions for its survival. Finally, we detected that areas that had previously become unsuitable because of climate change would have favorable conditions by the end of the century. Such an outcome could be useful in fostering an active restoration agenda that can mitigate the negative effects of climate change on species in this study.

Local social perception of mining in Parauapebas and Canaã dos Carajás in the eastern Amazonia, Brazil

The mineral industry plays a role in structural transformations in southeastern Pará, Eastern Amazonia, where large projects in this sector are located. This study analyzes aspects of the social perception of mining from image and reputation concepts in the Amazonian context. This paper aimed to examine the role of socioeconomic, political, and historical variables on social perception. It focused on four dimensions - economic, environmental, relationship and image, and general dimensions in Parauapebas and Canaã dos Carajás cities. The methodology consisted of the application in April of 2018 of questionnaires in a stratified sample of 960 and 349 randomly selected households in each of those cities, respectively. We employed the PCA/factor analysis method to examine whether a set of variables is relevant to social perception. The study found that the mining industry is a partner – not an intruder – because its beginning coincided with the social and historical formation of the territory. Perceptions of image and reputation were positive. Interviewee education, age, income, Whatsapp and Facebook usage, having a formal job, belonging to a union and a political party, occupation, and time of arrival are the main factors for social perception of mining. Despite their significantly negative opinion concerning mining's environmental impact, most interviewees pointed out that mining is reliable, friendly, transparent, and involved with the municipalities' problems. Our work fills a gap in growing literature that shows the challenges of companies, governments, and civil society in contemplating the dynamic aspects of mining for effective planning aiming at the social sustainability of mining regions.

VIDA NUA: o desvalimento social das personagens infantis em Chove nos Campos de Cachoeira de Dalcídio Jurandir

This work is an analysis of the work chove nos campos de cachoeira (1941) by Dalcídio Jurandir. The text portrays a decadent image of the environment by revealing the instability of the lives of those who live in Cachoeira do Arari. Existential problems linked to identity, at the same time that it denounces a series of social facts linked to the class struggle. In this way, the embryonic novel portrays countless children's characters, boys and girls who want to have a name, and sometimes even have a voice. Therefore, we seek to verify, through the attentive and detailed look of the protagonist Alfredo, the social reality of child characters who are socially inferior and dependent on other people's charity, poor children who are on the margins of childhood and a dignified life. Therefore, to discuss this declining environment in the post-rubber cycle Amazonian context, we will use the ideas of the Italian, Giorgio Agamben, on the state of exception and Vida Nana, as well as José Hage's considerations on the figurations of the poor in Dalcídio Jurandir.

Food Systems and Access to Healthy Food in an Amazonian Context

The article aims to identify how systemic, multi-scale dynamics influence access to adequate and healthy food and eating and how food is produced and circulated in the Amazonian context of the Metropolitan Region of Santarém (PA). We conducted a literature review, qualitative interviews with key actors, discussion groups and visits to food retailers to address the following research questions: how do socio-economic and political dynamics, especially those related to the soy-meat agroindustrial complex, create or reproduce social inequalities, injustices and inequities, and how do they affect the access to adequate and healthy food? Our findings suggest that the expansion of large-scale soybean growing and livestock, forming the industrial soy-meat complex, contributes to the impoverishment of certain social segments of the local population, accompanied by the erosion of the base for food production. Smallholder farmers and Indigenous and traditional people are among the main affected groups, while violence in rural areas contributes to restricting access to adequate and healthy food. The novelties of our study lie in approaching food systems, taking access to food as the entry point and linking adverse effects of the soy-meat complex to inequalities in access to healthy food. The study also discusses value conflicts between “traditional” and “modern food” (e.g., ultra-processed food), reflecting intergenerational disputes between ways of life and culture, which are also nurtured by the expansion of the soy-meat complex. These multi-scale dynamics have significant repercussions on how food is produced and circulated and highlight the relations between local food politics and conflicts, as well as their connections with processes beyond the local scale. Finally, the article calls for advancing integrated and multi-scale analysis of food production and access to address challenges of social injustices in food system transitions, fostering sustainability, human health and climate change mitigation and adaptation.

CUIDADO DOMICILIAR DA CRIANÇA EM USO DE TRAQUEOSTOMIA: PERSPECTIVA DOS CUIDADORES NO CONTEXTO AMAZÔNICO

ABSTRACT Objective: To describe caregivers’ perception of tracheostomized children about the challenges in discharge to their homes in the Amazonian context. Method: A descriptive, qualitative study was conducted with 16 caregivers of tracheostomized children who experienced dehospitalization in a children’s hospital in Rio Branco - Acre - Brazil. Saturation-defined sampling, data collected with a semi-structured script from August to December 2021, submitted to Bardin Content Analysis. Results: the analysis resulted in four categories: (1) feelings experienced with the use of the tracheal device; (2) routine tracheostomy care that caregivers consider important; (3) questions and reports about tracheal aspiration; and (4) conduct in the face of complications in children using tracheostomy. Final remarks: the fear of learning the tracheal aspiration technique and of being discharged from the hospital reinforces the need for early and continuous education for caregivers, focusing on routine and emergency care for tracheostomized children.

Participation in an indigenous Amazonian-led ayahuasca retreat associated with increases in nature relatedness – a pilot study

Indigenous Amazonian shamanic ayahuasca practice is embedded in a nature-based context and is employed as an ecological mediating agent and in collective environmental decision-making processes by some of the groups that use it. Phenomenologically, the ayahuasca experience is often rich in nature-based themes and content, and its usage has been associated with eliciting shifts in perspectives and attitudes towards nature. In this proof-of-concept study, participation in an ayahuasca retreat in a traditional Indigenous Amazonian context (with a mean of 6.31 ceremonies attended) was associated with significant increases in nature relatedness directly following ayahuasca retreats as assessed via the Short form Nature Relatedness Scale (NR-6) and The Extended Inclusion of Nature in Self scale (EINS), and improvements in depression and stress as assessed via the Depression, Anxiety and Stress Scale (DASS-21) were also found, but not on the anxiety subscale. Furthermore, a significant negative correlation with moderate effect size was found between changes in nature-relatedness and stress, suggesting that an increase in nature relatedness is associated with decreased stress levels after attending Amazonian ayahuasca retreats in our sample. It is currently unclear if the changes seen were due to consumption of the ayahuasca brew, participation in ceremony, or the retreat setting itself. Although this pilot study suggests a potential therapeutic role for Amazonian ayahuasca retreats as a multidimensional intervention, further work is required to assess the role of possible mediators underlying such shifts, while evaluating to what extent these are sustained for long term.

Challenges and Opportunities in the Practice of Environmental Education in the Amazon Context: a Legal-Constitutional Approach

This work aims to analyze the challenges and opportunities encountered in the practice of environmental education in the Amazonian context, adopting a legal-constitutional approach. The methodology used consists of a literature review and critical analysis of studies, laws, and legal documents related to environmental education and environmental protection in the Amazon region. The originality and relevance of this study lie in filling a theoretical gap by investigating how the legal-constitutional approach can contribute to the effectiveness of environmental education in the Amazon. Furthermore, the addressed theme holds great academic and social significance, considering the importance of the Amazon region for global biodiversity and the fundamental role of environmental education in awareness and environmental preservation. The main results indicate the need for greater integration between legal-constitutional aspects and the practice of environmental education in the Amazon region. The legal approach contributes to strengthening legal instruments for environmental protection and promoting greater awareness and engagement of society in preserving the Amazon. The theoretical and methodological contributions of this study are related to understanding the importance of the legal-constitutional framework as a fundamental support for the effectiveness of environmental education. Additionally, the social and environmental implications are significant, as effective environmental education can promote public awareness and encourage sustainable practices, thereby contributing to the preservation of the environment and sustainable development of the Amazon region.

Demographic Profile, Health, and Associated Factors of Family Caregivers and Functionality of Hospitalized Older Adults: Cross-Sectional, Exploratory, and Descriptive Study.

The longevity of the world population can contribute to an increase in hospitalizations and, consequently, to the emergence of functional limitations, resulting in the need for family caregivers. Hospitalized older adults may become dependent and require more care, increasing the burden on family caregivers. Thus, the nursing team in the hospital environment faces a new situation: an increase in the number of older adults occupying hospital beds and the presence of their family caregivers. We aimed to analyze the association between the demographic variables of interest and the self-rated health of family caregivers and to describe the functionality of older adults hospitalized in a university hospital in the Amazonian context. This cross-sectional, quantitative, exploratory, and descriptive study was carried out through individual interviews with 98 interviewees, divided into 49 family caregivers and 49 older adults hospitalized in the surgical clinic sector of a university hospital in Brazil between February and March 2023. Demographic data and health conditions were collected from family caregivers, and to describe the functionality of hospitalized older adults, the Barthel Index was applied. Descriptive (frequency and percentage) and inferential analyses were used, and the student t test was applied. The significance level of 5% was adopted. Among the 49 family caregivers, the majority were women (n=40, 81.6%) with an average age of 46.9 (SD 13.3) years. Most were single (n=28, 57.1%) and had completed an average level of education (n=26, 53.1%). Additionally, 25 (51%) caregivers were caring for their parents. Regarding health conditions, respondents self-assessed their health as good (25/49, 51%; P=.01), and they considered that their health status was not affected by the provision of care (36/49, 73.5%; P=.01). There was a significant association between demographic variables (ie, gender, age, and education) and self-assessment of family caregivers (P=.01, P=.01, and P=.04, respectively). Of the 49 older adults hospitalized, the majority (n=31, 63.2%) were men, with a mean age of 69.2 (SD 7.12) years. Regarding the assessment of functionality, most older adults were classified as having mild dependence on care (n=23, 46.9%), specifically in the age group between 60 and 69 years (21/49, 67.8%). The data revealed that female gender, age, and education of family caregivers contributed favorably to the provision of care to hospitalized older adults with a lower degree of functional dependence. It is important to emphasize that during the older adult's hospitalization, the family caregiver should not be seen as a delegation of responsibilities or as a complement of human resources to assist in their recovery. Health professionals need to implement assertive interventions so that the family caregiver functions as a therapeutic resource.

Amazon Biobusiness Center: legal advantages to its management by a Social Organization

This article deals with the management of the Amazon Biobusiness Center (CBA), which in 2023 became led by the Fundação Universitas de Estudos Amazônicos (FUEA). It aims to present to the scientific community and society in general some legal funding, as well as an analysis related to the new management of CBA as a Social Organization (SO). In an Amazonian context of biodiversity, the case of the Center is analyzed from a historical perspective. For that, the case study is used to verify that the difficulty of the CBA in emerging as a biobusiness center, based on biotechnology, had some roots in its old legal nature - whose change can bring some solutions to the case in question, without leaving to consider other obstacles that the management model per OS can flourish.

Identifying Urban and Socio-Environmental Patterns of Brazilian Amazonian Cities by Remote Sensing and Machine Learning

Identifying urban patterns in the cities in the Brazilian Amazon can help to understand the impact of human actions on the environment, to protect local cultures, and secure the cultural heritage of the region. The objective of this study is to produce a classification of intra-urban patterns in Amazonian cities. Concretely, we produce a set of Urban and Socio-Environmental Patterns (USEPs) in the cities of Santarém and Cametá in Pará, Brazilian Amazon. The contributions of this study are as follows: (1) we use a reproducible research framework based on remote sensing data and machine learning techniques; (2) we integrate spatial data from various sources into a cellular grid, separating the variables into environmental, urban morphological, and socioeconomic dimensions; (3) we generate variables specific to the Amazonian context; and (4) we validate these variables by means of a field visit to Cametá and comparison with patterns described in other works. Machine learning-based clustering is useful to identify seven urban patterns in Santarém and eight urban patterns in Cametá. The urban patterns are semantically explainable and are consistent with the existing scientific literature. The paper provides reproducible and open research that uses only open software and publicly available data sources, making the data product and code available for modification and further contributions to spatial data science analysis.

Nickel mass balance and isotopic records in a serpentinic weathering profile: Implications on the continental Ni budget

During serpentinite rock weathering, Ni is concentrated in the regolith owing to residual and secondary enrichment, forming a Ni-rich deposit under tropical conditions. This study presents geochemical, isotopic, and mineralogical data for Ni from the Serra do Puma Complex (SPC) weathering profile in Carajas (Brazil). The Ni fluxes, redistribution, and Ni isotopic fractionation magnitudes were quantified along the entire weathering profile: rock, saprock, lower and upper saprolite, and limonite. The results show that chlorite and serpentine are the primary Ni-scavenging phases in saprolite, whereas Fe oxyhydroxides are the main Ni-hosting minerals in the limonite unit. The mass balance model confirmed a global Ni gain at the weathered profile scale, with larger Ni enrichment in the upper saprolite. The isotopic dataset obtained in this study contributes greatly to the knowledge of the current Ni cycle on regional and global scales. The detailed insights into Ni isotopes in the SPC, coupled with chemical and mineralogical composition, allow for the first time a Ni mass balance and Ni isotopic values for an entire weathering profile in an Amazonian context. The Ni isotopic profile agrees with the preferential retention of light Ni isotopes in the residual material relative to the parent rock during weathering processes, with the Δ60Ni limonite-saprock of −0.72‰. In the SPC, major isotopic fractionation was notably recorded during saprolitization, while limonitization was accompanied by an overall Ni loss without significant Ni isotopic fractionation. As already observed in previous studies, heavier Ni isotopes, preferentially leached during weathering processes, can be further mobilized downward and lost from the profile or incorporated in secondary minerals in the saprolite and limonite sections. The Ni isotopic mass balance model indicated that the Ni loss from the weathered serpentinite profile was isotopically heavy, in agreement with the isotopically heavier composition of the dissolved load of Amazonian rivers. The isotopically light Ni pool, associated with the significant Ni gain encountered in the upper saprolite, is notable in the SPC weathering profile and confirms the existence of a light Ni isotope reservoir in the continent.

Inquiry-Based Science Teaching and the Development of Teaching Knowledge in Amazonia

Background: In the face of investigations on how Amazonia is presented in textbooks (TBs), it is clear that there is a limitation in approaching this topic, as it is loaded with stereotypes disregarding socio-environmental issues. Objectives: To understand how teaching knowledge is mobilised by teachers from a formative activity centred on investigative teaching sequences in the Amazonian context. Design: With this in mind, we started with an action research. Setting and Participants: It took place in a municipal school in Ananindeu/PA, with the participation of all teachers who worked in the initial years of elementary school of this institution, a total of five teachers, aged between 28 and 49 years. They are the only members of the teaching staff serving the eight classes at the school, in the morning and afternoon shifts, all with a background in pedagogy and at least one specialisation. Data collection and analysis: We used semi-structured collective interviews, recorded in audio and video, which were later transcribed and analysed through content analysis, carried out in three stages: 1 - Pre-analysis, 2 - Exploration of the material and 3 – Treatment of results and interpretation, based on the theoretical framework adopted in the investigation Results: We understand the mobilisation of teaching knowledge in the construction of Investigative Teaching Sequences (ITSs) aimed at the Amazon context, as a viable alternative, since textbooks disregard the reality of Amazonia, making it invisible throughout its entirety complexity. Conclusions: In this sense, the proposition of inquiry-based science teaching through ITSs focused on the Amazonian context favours overcoming this regional neglect. Therefore, teachers and students can start with an investigative process that takes into account relevant and significant themes for both.

Incidence, causes, and risk factors of stillbirth in an Amazonian context: Saint Laurent du Maroni maternity ward 2016–2021

We aimed to describe the epidemiology of intrauterine fetal deaths in multiethnic western French Guiana and to assess its main causes and risk factors. A retrospective descriptive study was conducted based on data from January 2016 to December 2021. All information on stillbirth with a gestational age ≥20 weeks in the Western French Guiana Hospital Center was extracted. Terminations of pregnancy were excluded. We focused on medical history, clinical investigation, biological findings, placental histology, and autopsy examination to elucidate the cause of death. We used the Initial Cause of Fetal Death (INCODE) classification system for assessment. Univariable and multivariable logistic regression analyses were performed. Overall, 331 fetuses in 318 stillbirth deliveries were reviewed and compared to live births that occurred during the same period. The rate of fetal death varied between 1.3 % and 2.1 %, with an average of 1.8 % over the 6-year period. Poor antenatal care (104/318, 32.7 %), obesity ≥30kg/m2 (88/318, 31.7 %), and preeclampsia (59/318, 18.5 %) were the main risk factors associated with fetal death in this group. Four hypertensive crises were reported. According to the INCODE classification, the main causes of fetal death were obstetric complications (112/331, 33.8 %), particularly intrapartum fetal death with labor-associated asphyxia under 26 weeks (64/112, 57.1 %), and placental abruption (29/112, 25.9 %). Maternal-fetal infections were common, particularly mosquito-borne diseases (e.g., Zika virus, dengue, and malaria), re-emerging infectious agents such as syphilis, and severe maternal infections (8/331, 2.4 %). 19.3 % of fetal deaths (64/331) remained unexplained. Change in lifestyle as well as social deprivation and isolation adversely affect pregnancy in western French Guiana, in the context of a poor health care system that is similar to what is found in the Amazonian basin. Particular attention must be paid to emerging infectious agents in pregnant women and travelers returning from the Amazon region.

A Port by Any Other Name: A Preliminary Spatial Analysis of Ancient Infrastructural Landscapes and Settlement Organization at Macurany, Brazil

AbstractComplex human–environmental processes form identifiable, lasting features on the landscape that can illuminate past human behavior and human–environment interactions. We examine the anthropogenic landscape of the ancient port of Macurany, located along the middle Amazon River in Parintins, Brazil, and identify four classes of anthropogenic landscape features at the site: wharfs, middens, terra preta (dark or black earths), and cultural forests. Middens, terra preta, and cultural forests have been found at archaeological sites in regions surrounding Macurany, but wharfs have not previously been reported in Amazonian contexts predating European contact. Taken together, these features are clearly the result of anthropogenesis and represent a range of subsistence, settlement, and infrastructure-building activities pointing to an ancient society that was actively engaged in modifying the surrounding landscape for purposes beyond settlement and subsistence. Evidence for a permanent, extensive, continuously settled society practicing intensive landscape engineering in this region of Amazonia reinforces findings of dense habitation, infrastructure, and early urbanization in Amazonia prior to European contact. This research helps expand our understanding of human–environment interactions, landscape formation processes, and settlement organization in ancient Amazonia.

Socio-ecological conflicts and (cosmo)political reconfigurations in the Peruvian Amazonia: the case of the Wampis Nation

ABSTRACT This paper, which draws on research carried out in collaboration with the first indigenous government to be officially constituted in the Peruvian Amazonia, the Gobierno Territorial Autónomo de la Nación Wampís (GTANW), describes the governance structure and territorial policies of this new political actor. Research activities conducted between June and August 2017 included fourteen interviews with Wampis political leaders and GTANW activists, three discussion groups organized and co-animated by the participants and the participant observation of a variety of activities related to the democratic life and territorial governance of the Wampis Nation. In the context of an explosion of social conflictuality caused by the expansion of extractive industries in Wampis territory, the GTANW puts into practice a vision of indigenous political and territorial self-determination that revendicates Wampis cosmopraxis, ancestral knowledge and traditional institutions of political leadership. Through a participatory democracy based on consensus building, Wampis political leaders and GTANW activists seek to establish an economic development model compatible with their worldview. Results suggest that, in the Peruvian Amazonian context, socio-ecological conflicts are rooted in different ontological understandings of the territory that is being disputed and of the stakeholder entities involved in the conflict, and therefore do not occur in a unified system of signs and cosmovisions shared by all the conflict stakeholders. The newly formed indigenous government’s intent is to create spaces for political dialogue in epistemic equality by translating their cosmovisions into terms that are negotiable to the State and other institutions.

Environmental conservation, spatial mobility, and living conditions of traditional populations in protected areas: for adequate health access models in the Amazonian context.

Environmental conservation, spatial mobility, and living conditions of traditional populations in protected areas: for adequate health access models in the Amazonian context.

Pedagogical practice in pandemic times: possibilities and challenges of basic education in the amazonian context from a perspective of creativity

We have experienced a scenario of transformations in education, where a resiginification emerges in the pedagogical practices to meet the reflexes of the covid 19 pandemic. In this sense, we will seek to discuss the context of the Amazon region and the pedagogical practices from the perspective of creativity. The objective is to analyze the current situation in a FullTime School, identifying the possibilities of creative practices in a pandemic context, if these practices that are being projected by SEMD through the Plan for the Resumption of Activities value creativity. We will seek to answer the question: What possibilities and challenges have teachers faced when planning their practice in this online teaching proposal? The research will be by theoretical and empiric al study, qualitative approach, data collection tool questionnaire in Google Forms. The results show that there was no system of collaboration between teachers, school and SEMED at the time of preparation.

FOOD CONSUMPTION OF MACRONUTRIENTS AND NUTRITIONAL STATUS OF PEOPLE WITH OSTOMY

Objective: To evaluate the food intake of macronutrients and nutritional status of people with ostomy in the Amazonian context. Method: Quantitative cross-sectional study carried out in the specialized reference unit for people with ostomy, in the period from January to March 2020. The sample consisted of 77 people with ostomies, aged 21 to 88 years old, of both genders. We used sociodemographic information, clinical and behavioral aspects, anthropometric measurements and 24-hour recall. Statistical analysis was performed using BioEstat 5.0 and EpiInfo 3.5.1 software. Results: Most were male, aged between 35 and 50 years old. The most frequent types of ostomy were: colostomy (69%) and ileostomy (21%), with a temporary nature (43%), with neoplastic etiology in both sexes (60%). As for the nutritional status, most presented eutrophy according to the body mass index, but waist circumference showed increased metabolic risk in females, and the triceps skinfold thickness indicated excess adiposity in males (<0.0001). Regarding food consumption, there was inadequacy of energy and macronutrients. Conclusion: Eating habits in the Amazonian context may be related to inadequate food consumption and changes in nutritional status.

Evaluation of Lean Manufacturing Practices in an Automotive Component Manufacturer

Purpose: This study aims to evaluate lean manufacturing (LM) practices used in a company in the automotive component industry located in Polo Industrial de Manaus (PIM), a manufacturing hub in the city of Manaus. Theoretical framework: The AME Lean Assessment instrument was used as the research framework in this study. This instrument was developed by the Association for Manufacturing Excellence (AME) to benchmark where a company is on its lean journey.Design/methodology/approach: An exploratory case study was carried out, and since a more detailed study was needed, a research framework was used, composed of 14 attributes on lean manufacturing.Findings: The findings point to a high level of LM practices adopted by the company, in addition to allowing the practical application of the fundamental concepts to be observed for the Toyota Production System (TPS) at Polo Industrial de Manaus. The findings have increased the understanding in organizational behavior relating to LM.Research, Practical & Social implications: the study contributes to the body of knowledge on lean manufacturing considering its application in the Amazonian context. The study has made a substantial contribution to the understanding of lean manufacturing in the context of an important industrial park in Brazil. Originality/value: Originality is the adoption of a research framework for evaluating lean manufacturing practices in an Amazonia context, allowing the specific characteristics of lean manufacturing to be understood in Amazonia, from an in-depth case.Keywords: Lean manufacturing; Lean Assessment; Industry; Automotive components; Amazonas.

Hydrological Scenarios and Malaria Incidence in the Amazonian Context

In Brazil, approximately 99% of malaria cases are concentrated in the Amazon region. An acute febrile infectious disease, malaria is closely related to climatic and hydrological factors. Environmental variables such as rainfall, flow, level, and color of rivers, the latter associated with the suspended sediment concentration, are important factors that can affect the dynamics of the incidence of some infectious diseases, including malaria. This study explores the possibility that malaria incidence is influenced by precipitation, fluctuations in river levels, and suspended sediment concentration. The four studied municipalities are located in two Brazilian states (Amazonas and Pará) on the banks of rivers with different hydrological characteristics. The results suggest that precipitation and river level fluctuations modulate the seasonal pattern of the disease and evidence the existence of delayed effects of river floods on malaria incidence. The seasonality of the disease has a different influence in each municipality studied. However, municipalities close to rivers with the same characteristic color of waters (as a function of the concentration of suspended sediments) have similar responses to the disease.