The effect of iron oxide nanoparticles on the fate and transformation of arsenic in aquatic environments

Iron oxides and arsenic are prevalent in the environment. With the increase interest in the use of iron oxide nanoparticles (IONPs) for contaminant remediation and the high toxicity of arsenic, it is crucial that we evaluate the interactions between IONPs and arsenic. The goal was to understand the environmental behavior of IONPs in regards to their particle size, aggregation and stability, and to determine how this behavior influences IONPs-arsenic interactions. ^ A variety of dispersion techniques were investigated to disperse bare commercial IONPs. Vortex was able to disperse commercial hematite nanoparticles into unstable dispersions with particles in the micrometer size range while probe ultrasonication dispersed the particles into stable dispersions of nanometer size ranges for a prolonged period of time. Using probe ultrasonication and vortex to prepare IONPs suspensions of different particle sizes, the adsorption of arsenite and arsenate to bare hematite nanoparticles and hematite aggregates were investigated. To understand the difference in the adsorptive behavior, adsorption kinetics and isotherm parameters were determined. Both arsenite and arsenate were capable of adsorbing to hematite nanoparticles and hematite aggregates but the rate and capacity of adsorption is dependent upon the hematite particle size, the stability of the dispersion and the type of sorbed arsenic species. Once arsenic was adsorbed onto the hematite surface, both iron and arsenic can undergo redox transformation both microbially and photochemically and these processes can be intertwined. Arsenic speciation studies in the presence of hematite particles were performed and the effect of light on the redox process was preliminary quantified. The redox behavior of arsenite and arsenate were different depending on the hematite particle size, the stability of the suspension and the presence of environmental factors such as microbes and light. The results from this study are important and have significant environmental implications as arsenic mobility and bioavailability can be affected by its adsorption to hematite particles and by its surface mediated redox transformation. Moreover, this study furthers our understanding on how the particle size influences the interactions between IONPs and arsenic thereby clarifying the role of IONPs in the biogeochemical cycling of arsenic.^

Educação ambiental como estratégia para inserção da sustentabilidade na formação em odontologia

This thesis proposes environmental education as a strategy for the inclusion of sustainability in the academic education of higher level. The dentistry course has been the object of study, which is justified by the recognition of the need for reflection on environmental issues in the dental academia, initially based on professional experience of the author as a dental surgeon. The aim of this study is to investigate the scientific production of dentistry and its content related to environmental issues, in addition to expanding discussions and reflections on the need to insert environmental education as academic content. With the specific purpose of verifying the amount and analyze the content of scientific articles involving issues related to sustainability in dentistry, Chapter 01 presents research in leading journals portals available on the internet. Works were surveyed where sustainability and related issues were present and placed in a theoretical framework that analyzes the dental service inclusion in the dominant economic model. These procedures are intended to prove the hypothesis that the dental profession does not produce significant scientific content that relates the profession to the environment and sustainability. A literature review was conducted with the statement of dentistry changes from its origins to the front position to the dominant development model and exemplification of the deleterious effects of this model on the environment. In addition, there was a scientific research in journals portals available on the internet and investigated the amount and content of scientific articles involving issues related to sustainability in dentistry. Chapter 02 has the specific purpose of providing content to expand discussions and reflections on the need to insert environmental education in undergraduate courses in dentistry, such as insertion strategy into a new development model guided by sustainability. In this, students questionnaires were given the 8th dentistry course of the period the Federal University of Rio Grande do Norte (UFRN), to be understood environmental perception of learners and were obtained grants for proof of the thesis that environmental education applied dentistry has the potential to make people aware and willing to act practicing and propagating sustainability in their conduct. The overall results indicate little scientific production, as the research and work that relates to dentistry to sustainability and the issues related to the environment have not significantly been present in the syllabus of the undergraduate courses in dentistry, despite the interest shown by survey respondents When such issues are addressed. In this context, it is proposed fostering actions to environmental education, so that dental professionals are engaged in the construction of a new development model based on sustainability, as despite the environmental theme seems to be little explored in the academic and scientific world of dentistry, there interest from students and great potential multiplier for appropriate environmental behavior. After proving the hypothesis that the environment-related content are poorly explored in the academic and scientific world of dentistry, the main conclusions were recognizing the importance of environmental education as an interdisciplinary tool for environmental thematic approach in undergraduate courses dentistry, in addition to implementing this new pedagogical proposal in the professional practice of dentists, given their potential multiplier for environmental knowledge.

Motivating residents to combat invasive species on private lands: social norms and community reciprocity

Invasive species (IS) threaten biodiversity and ecosystem functioning. To achieve landscape-scale reductions in IS and the associated gains for biodiversity, IS control efforts must be expanded across private lands. Enhancing IS control across private lands requires an understanding of the factors that motivate residents to engage or prohibit residents from engaging in efforts to control IS. Drawing from the collective interest model and literature, we sought to understand how a wide range of interpersonal, intrapersonal, and contextual factors might influence resident action around combating the invasive tree albizia (Falcataria moluccana), in the Puna District of Hawaiʻi. To do so, we used a cross-sectional survey of 243 residents and elastic net regression techniques. We found that residents’ actions related to IS control were related to their perceptions of social norms and community reciprocity regarding albizia control, as well as their knowledge of effective control strategies and their risk perceptions regarding albizia. These findings suggest that, although common intervention approaches that focus on providing education or subsidies are important, they may be more effective at reducing the spread of IS if coupled with approaches that build community reciprocity and norms.

“I know, therefore I adapt?” Complexities of individual adaptation to climate-induced forest dieback in Alaska

Individual actions to avoid, benefit from, or cope with climate change impacts partly shape adaptation; much research on adaptation has focused at the systems level, overlooking drivers of individual responses. Theoretical frameworks and empirical studies of environmental behavior identify a complex web of cognitive, affective, and evaluative factors that motivate stewardship. We explore the relationship between knowledge of, and adaptation to, widespread, climate-induced tree mortality to understand the cognitive (i.e., knowledge and learning), affective (i.e., attitudes and place attachment), and evaluative (i.e., use values) factors that influence how individuals respond to climate-change impacts. From 43 semistructured interviews with forest managers and users in a temperate forest, we identified distinct responses to local, climate-induced environmental changes that we then categorized as either behavioral or psychological adaptations. Interviewees developed a depth of knowledge about the dieback through a combination of direct, place-based experiences and indirect, mediated learning through social interactions. Knowing that the dieback was associated with climate change led to different adaptive responses among the interviewees, although knowledge alone did not explain this variation. Forest users reported psychological adaptations to process negative attitudes; these adaptations were spurred by knowledge of the causes, losses of intangible values, and impacts to a species to which they held attachment. Behavioral adaptations exclusive to a high level of knowledge included actions such as using the forests to educate others or changing transportation behaviors to reduce personal energy consumption. Managers integrated awareness of the dieback and its dynamics across spatial scales into current management objectives. Our findings suggest that adaptive management may occur from the bottom up, as individual managers implement new practices in advance of policies. As knowledge of climate-change impacts in local environments increases, resource users may benefit from programs and educational interventions that facilitate coping strategies.

BALD EAGLES (HALIAEETUS LEUCOCEPHALUS) AS INDICATORS OF GREAT LAKES ECOSYSTEM HEALTH

Environmental indicators have been proposed as a means to assess ecological integrity, monitoring both chemical and biological stressors. In this study, we used nestling bald eagles as indicators to quantify direct or indirect tertiary-level contaminant exposure. The spatial and temporal trends of polychlorinated biphenyl (PCB) congeners were evaluated in nestling plasma from 1999–2014. Two hexa-chlorinated congeners, PCB-138 and 153, were detected with the highest frequency and greatest concentrations throughout Michigan. Less-chlorinated congeners such as PCB-52 and 66 however, comprised a greater percentage of total PCB concentrations in nestlings proximate to urbanized areas, such as along the shorelines of Lake Erie. Toxic equivalents were greatest in the samples collected from nestlings located on Lake Erie, followed by the other Great Lakes spatial regions. Nestling plasma samples were also used to measure concentrations of the most heavily-used group of flame retardants, brominated diphenyl ethers (BDEs), and three groups of alternative flame retardants, non-BDE Brominated Flame Retardants (NBFRS), Dechloranes, and organophosphate esters (OPs). BDE-47, 99 and 100 contributed the greatest to total BDE concentrations. Concentrations of structurally similar NBFRs found in this study and recent atmospheric studies indicate that they are largely used as replacements to previously used BDE mixtures. A variety of Dechloranes, or derivatives of Mirex and Dechlorane Plus, were measured. Although, measured at lesser concentrations, environmental behavior of these compounds may be similar to mirex and warrant future research in aquatic species. Concentrations of OPs in nestling plasma were two to three orders of magnitude greater than all other groups of flame retardants. In addition to chemical indicators, bald eagles have also been proposed as indicators to identify ecological stressors using population measures that are tied to the fitness of individuals and populations. Using mortality as a population vitality rate, vehicle collisions were found to be the main source of mortality with a greater incidence for females during white-tailed deer (Odocoileus virginianus) hunting months and spring snow-melt. Lead poisoning was the second greatest source of mortality, with sources likely due to unretrieved hunter-killed, white-tailed deer carcasses, and possibly exacerbated by density-dependent effects due to the growing population in Michigan.

The Effect of Iron Oxide Nanoparticles on the Fate and Transformation of Arsenic in Aquatic Environments

Iron oxides and arsenic are prevalent in the environment. With the increase interest in the use of iron oxide nanoparticles (IONPs) for contaminant remediation and the high toxicity of arsenic, it is crucial that we evaluate the interactions between IONPs and arsenic. The goal was to understand the environmental behavior of IONPs in regards to their particle size, aggregation and stability, and to determine how this behavior influences IONPs-arsenic interactions. A variety of dispersion techniques were investigated to disperse bare commercial IONPs. Vortex was able to disperse commercial hematite nanoparticles into unstable dispersions with particles in the micrometer size range while probe ultrasonication dispersed the particles into stable dispersions of nanometer size ranges for a prolonged period of time. Using probe ultrasonication and vortex to prepare IONPs suspensions of different particle sizes, the adsorption of arsenite and arsenate to bare hematite nanoparticles and hematite aggregates were investigated. To understand the difference in the adsorptive behavior, adsorption kinetics and isotherm parameters were determined. Both arsenite and arsenate were capable of adsorbing to hematite nanoparticles and hematite aggregates but the rate and capacity of adsorption is dependent upon the hematite particle size, the stability of the dispersion and the type of sorbed arsenic species. Once arsenic was adsorbed onto the hematite surface, both iron and arsenic can undergo redox transformation both microbially and photochemically and these processes can be intertwined. Arsenic speciation studies in the presence of hematite particles were performed and the effect of light on the redox process was preliminary quantified. The redox behavior of arsenite and arsenate were different depending on the hematite particle size, the stability of the suspension and the presence of environmental factors such as microbes and light. The results from this study are important and have significant environmental implications as arsenic mobility and bioavailability can be affected by its adsorption to hematite particles and by its surface mediated redox transformation. Moreover, this study furthers our understanding on how the particle size influences the interactions between IONPs and arsenic thereby clarifying the role of IONPs in the biogeochemical cycling of arsenic.

Diseño, implementación y seguimiento de estrategias de sensibilización en valores corporativos orientados a la sostenibilidad para el personal administrativo de OMA

Nacional e internacionalmente, la sostenibilidad se ha convertido en el punto clave de las grandes organizaciones, sus actividades y los participantes que se encuentran involucrados. Una empresa es sostenible cuando ha encontrado el equilibrio entre el aspecto económico, social y ambiental, logrando sin lugar a dudas éxito y perdurabilidad en el entorno al que pertenece. Es por esto que el principal objetivo de este proyecto es el diseño e implementación de estrategias de sensibilización en valores corporativos para el personal administrativo de OMA, el cual se enfoca en la creación y desarrollo de actividades que permitan la concientización y cambios en el comportamiento ambiental de los colaboradores de la compañía. A partir de múltiples herramientas como conceptos básicos, normatividad y actividades dinámicas se logró informar y capacitar a los colaboradores de la compañía en temas como la importancia del desarrollo sostenible, política ambiental y prácticas ambientales adecuadas dentro del entorno laboral y sus hogares.

Solastalgia y conductas pro-ambientales en un conflicto socioambiental por la construcción de una hidroeléctrica

Introducción: La construcción de megaproyectos hídricos implica una reconfiguración territorial donde se ven afectadas las fuentes de agua dulce, la biodiversidad terrestre y acuática, y los asentamientos humanos que colindan con dichas construcciones. Objetivo: estimar la asociación entre las conductas proambientales con la solastalgia entre las personas que se encuentran ejerciendo un proceso de resistencia social contra la Central Hidrosogamoso en el departamento de Santander, Colombia. Metodología: se utilizó un diseño de estudio transversal en el que se entrevistaron integrantes y no integrantes de grupos ambientalistas de las zonas de influencia del proyecto. Se realizó un análisis descriptivo de las variables sociodemográficas de los dos grupos de comparación presentando frecuencias absolutas y relativas y diferencias significativas por medio de la prueba ji cuadrado, exacta de Fisher y U de Mann Whitney. Se utilizó un modelo de regresión lineal múltiple en el que la variable dependiente fue el puntaje de solastalgia y las variables independientes fueron las escalas de las conductas proambientales: altruismo, austeridad, equidad, conducta ecológica, deliberación, indignación y aprecio por lo natural, además, se ajustó por algunas variables sociodemográficas de interés. Resultados: los grupos comparados presentaron diferencias importantes en cuanto a la zona de procedencia, condiciones económicas y organización social. El incremento de 5 puntos en la escala del sentimiento de indignación incrementó 0.98 la escala de solastalgia (IC95%: 0.19; 1.78). Las personas sin pareja estable tuvieron 3.02 puntos menos de solastalgia comparadas con personas casadas o en unión libre (IC95%: -4.96; -1.44), mientras que aquellas con alto nivel educativo obtuvieron 2.02 puntos menos que las personas con primaria y bachillerato (IC95%: -3.99; -0.06). Un modelo alterno mostró que no pertenecer a un grupo ambientalista disminuye en 2.29 puntos la solastalgia, comparado con pertenecer a un grupo (IC95%: -4.31; -0.28),. Conclusión: posiblemente las motivaciones por las cuales los actores involucrados se resisten a las transformaciones territoriales ocasionadas por la construcción de las represas son más un reflejo de la condición socioeconómica que de la preocupación de los actores por el daño del medio ambiente y además, esta resistencia es un fenómeno que se limita a aquellos que están afectados directamente en el área de influencia del proyecto

Reciclaje de residuos sólidos domésticos y conductas pro-ambientales en una comunidad residencial de Bogotá, Colombia

Introducción: La implicación social dentro de la problemática ambiental, establece una relación causal entre hábitos e impacto ambiental; aspectos del comportamiento humano tales como la conveniencia, familiaridad, presión social y actitud, nos permiten realizar un acercamiento acerca de la decisión de reciclar o no en un hogar. Objetivo: identificar los factores ambientales asociados con el manejo de residuos domésticos entre los miembros de una comunidad residencial en la ciudad de Bogotá. Materiales y métodos: Se realizó un estudio transversal realizado a 200 personas de una comunidad residencial. La evaluación de la conducta pro-ambiental se llevó a cabo por medio de la utilización de la Escala del Comportamiento Pro-ambiental desarrollada por Corral-Verdugo unida a la escala de Reciclaje de Sidique. Para el tratamiento estadístico se empleó el análisis de regresión lineal múltiple. Resultados: La mayoría de los encuestados fueron hombres (55%), con una mediana de edad de 37,5 años. Más de la mitad tenía por lo menos formación en pregrado (53%), el 55,5% contaban con un empleo al momento de la entrevista, cerca del 50% de las personas refirieron tener casa propia y la mediana del tamaño de las mismas fue de 80 m2. De los aspectos sociodemográficos, el tipo de vivienda, sexo y edad, estuvieron relacionados con los factores ambientales pro reciclaje. Mientras que las conductas proambientales relacionadas fueron: altruismo, frugalidad, conducta ecológica general, indignación y aprecio por la naturaleza. Conclusiones: Las conductas proambientales Altruismo, Frugalidad, Conducta Ecológica, Indignación y Aprecio por lo natural, están relacionadas con la intención de reciclar. Para futuras investigaciones es necesario constatar la realización del comportamiento proambiental, para aseverar de manera irrebatible que las dimensiones analizadas pueden soportar una acción real y no un auto reporte de una conducta.

Agonistic behavior and environmental enrichment of cats communally housed in a shelter

Objective-To evaluate the presence of a dominance rank in a group of cats and the relation between agonistic behavior and the use of resources, including environmental enrichment, in these cats. Design-Observational analytic study. Animals-27 neutered cats in a shelter in Sao Paulo, Brazil. Procedures-The cats were video recorded for 4 consecutive days to obtain baseline data. Subsequently, a puzzle feeder was added as an enrichment device every other day over 8 days, for a total of 4 days with enrichment. Cats were also video recorded on these days. All pretreatment and posttreatment agonistic behaviors and interactions with the puzzle feeder were recorded by reviewing the videotapes. Results-143 agonistic encounters were recorded, of which 44 were related to resources and 99 were not. There were insufficient agonistic interactions to determine a dominance rank. Presence or absence of the puzzle feeder did not affect the rate of aggression. There was no significant effect of weight, sex, or coat color on the rate of aggression, and aggressive behavior did not correlate with time spent with the puzzle feeder. Twenty-three of the 27 cats interacted with the puzzle feeder. Conclusions and Clinical Relevance-In a stable group of communally housed cats, environmental enrichment did not cause increased aggression as a result of competition for the source of enrichment. Because environmental enrichment increases the opportunity to perform exploratory behaviors, it may improve the welfare of groups of cats maintained long-term in shelters, sanctuaries, or multicat households. (J Am Vet Med Assoc 2011239:796-802)

La dépendance à l'égard de l'environnement lors de lésions cérébrales: conduites d'imitation, de préhension et d'utilisation [Environmental dependence in brain lesions: imitative behavior, prehension and utilization].

This paper reviews the literature on clinical signs such as imitation behavior, grasp reaction, manipulation of tools, utilization behavior, environmental dependency, hyperlexia, hypergraphia and echolalia. Some aspects of this semiology are of special interest because they refer to essential notions such as free-will and autonomy.

Influence of Environmental Conditioning on the Shear Behavior of Poly(phenylene sulfide)/Glass Fiber Composites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Broiler breeder behavior and egg production as function of environmental temperature

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)