Fate and Reactivity of Natural and Manufactured Nanoparticles in Soil/Water Environments

Nanoparticles (NPs), \u3c 100 nm in diameter, make up the smallest component of solid material. This small size often causes increased reactivity in soil/water environments, which is true for both natural NPs, such as very fine clay particles, and for manufactured nanoparticles, such as silver nanoparticles (AgNPs). As the importance of these particles is more widely recognized, and as manufactured nanoparticles, especially AgNPs, are increasing in production, it is essential to consider their effect on terrestrial and aquatic environments. The studies presented in this dissertation show that both the physicochemical characteristics of the NPs (e.g., particle size, surface coating, elemental composition), as well as soil-water interfacial chemistry (e.g., ionic strength, ligand concentration, pH), are instrumental in predicting environmental fate and reactivity. Ligand type and concentration were especially important in NP reactivity and bioavailability. Using the hard/soft acid/base concept, the effect of phosphate ligand (hard base) on Fe/Al (hard acid) oxyhydroxide natural NPs was investigated in Chapters 2 and 3. Adding phosphate to soil NPs and reference nano-minerals (Fe-(oxyhydr)oxides and kaolinite) caused coagulation or dispersion, changing the particle size of the NPs, as well as affecting the amount of phosphate in its bioavailable (i.e., dissolved) form. A review of the literature in Chapters 1 and 3 revealed that changes in the soil conditions, and therefore, soil colloids/NPs (e.g., increasing organic matter via amendments), also has a direct impact on the soil NP-facilitated phosphate transport processes. Silver, a soft acid, reacts readily with thiol functional groups, soft bases, in humic substances prevalent in soil environments. The effect of soil constituents on AgNP reactivity and phase transformation was investigated in Chapters 4 and 5. The presence of solid surfaces facilitated sorption and phase transformation in all AgNPs studied over the course of 30 days, especially when compared to the same AgNPs aged in aqueous environments in the absence of soil. When the bioavailability of Ag (as ionic and NPs), a known antimicrobial agent, was assessed via denitrification experiments in Chapter 5, the AgNPs exhibited much less toxicity than expected, perhaps due to their strong sorption onto soil particles, as observed in the adsorption isotherm experiments conducted in Chapter 4. A more in-depth study of Ag(I) and AgNPs, and their interactions with cysteine, an amino acid with a thiol functional group, at the goethite-water interface in Chapter 6 revealed that, while cysteine enhanced the sorption of Ag(I) on goethite surfaces by forming inner-sphere ternary surface complexes, AgNP sorption to goethite was largely unaffected by cysteine. The behavior suggests hydrophobic interactions of AgNPs on goethite surfaces, revealing the effects of a soft ligand on Ag are via species specific (Ag(I) or AgNPs) mineral interactions, and are important in predicting AgNP fate in soil systems. This dissertation provides a novel viewpoint of natural and manufactured NP interactions in soil environments. These interactions are dictated by both particle-specific characteristics and environmental conditions. When environmental conditions, especially the presence of reactive ligands (based on the hard/soft acid/base theory), are altered by anthropogenic or indigenous means, the reactivity of certain NPs changes dramatically, impacting the bioavailability of contaminants such as phosphate, Ag(I), or AgNPs

Parallel-Correctness and Transferability for Conjunctive Queries under Bag Semantics

Single-round multiway join algorithms first reshuffle data over many servers and then evaluate the query at hand in a parallel and communication-free way. A key question is whether a given distribution policy for the reshuffle is adequate for computing a given query. This property is referred to as parallel-correctness. Another key problem is to detect whether the data reshuffle step can be avoided when evaluating subsequent queries. The latter problem is referred to as transfer of parallel-correctness. This paper extends the study of parallel-correctness and transfer of parallel-correctness of conjunctive queries to incorporate bag semantics. We provide semantical characterizations for both problems, obtain complexity bounds and discuss the relationship with their set semantics counterparts. Finally, we revisit both problems under a modified distribution model that takes advantage of a linear order on compute nodes and obtain tight complexity bounds

Robustness Against Read Committed for Transaction Templates with Functional Constraints

The popular isolation level Multiversion Read Committed (RC) trades some of the strong guarantees of serializability for increased transaction throughput. Sometimes, transaction workloads can be safely executed under RC obtaining serializability at the lower cost of RC. Such workloads are said to be robust against RC. Previous work has yielded a tractable procedure for deciding robustness against RC for workloads generated by transaction programs modeled as transaction templates. An important insight of that work is that, by more accurately modeling transaction programs, we are able to recognize larger sets of workloads as robust. In this work, we increase the modeling power of transaction templates by extending them with functional constraints, which are useful for capturing data dependencies like foreign keys. We show that the incorporation of functional constraints can identify more workloads as robust that otherwise would not be. Even though we establish that the robustness problem becomes undecidable in its most general form, we show that various restrictions on functional constraints lead to decidable and even tractable fragments that can be used to model and test for robustness against RC for realistic scenarios

Introduction to Environmental Science: 2nd Edition

2nd Edition: Revised by Kalina Manoylov, Allison Rick VandeVoort, Christine Mutiti, Samuel Mutiti and Donna Bennett in 2017. Authors\u27 Description: This course uses the basic principles of biology and earth science as a context for understanding environmental policies and resource management practices. Our planet is facing unprecedented environmental challenges, from oil spills to global climate change. In ENSC 1000, you will learn about the science behind these problems; preparing you to make an informed, invaluable contribution to Earth’s future. I hope that each of you is engaged by the material presented and participates fully in the search for, acquisition of, and sharing of information within our class. Environmental Science Laboratory (ENSC 1000L) is a separate class and you will receive a separate grade for that course. Course Objectives Upon completion of this course, you will be able to: Evaluate the diverse responses of peoples, groups, and cultures to environmental issues, themes and topics. Use critical observation and analysis to predict outcomes associated with environmental modifications. Demonstrate knowledge of the causes & consequences of climate change. Apply quantitative skills to solve environmental science problems. Demonstrate knowledge of environmental law and policy. Design and critically evaluate experiments. Interpret data in figures and graphs. This open textbook for Introduction to Environmental Science was created under a Round Two ALG Textbook Transformation Grant. Accessible files with optical character recognition (OCR) and auto-tagging provided by the Center for Inclusive Design and Innovation.https://oer.galileo.usg.edu/biology-textbooks/1003/thumbnail.jp

Mammalian oocytes are targets for prostaglandin E2 (PGE2) action

<p>Abstract</p> <p>Background</p> <p>The ovulatory gonadotropin surge increases synthesis of prostaglandin E2 (PGE2) by the periovulatory follicle. PGE2 actions on granulosa cells are essential for successful ovulation. The aim of the present study is to determine if PGE2 also acts directly at the oocyte to regulate periovulatory events.</p> <p>Methods</p> <p>Oocytes were obtained from monkeys and mice after ovarian follicular stimulation and assessed for PGE2 receptor mRNA and proteins. Oocytes were cultured with vehicle or PGE2 and assessed for cAMP generation, resumption of meiosis, and in vitro fertilization.</p> <p>Results</p> <p>Germinal vesicle intact (GV) oocytes from both monkeys and mice expressed mRNA for the PGE2 receptors EP2, EP3, and EP4. EP2 and EP4 proteins were detected by confocal microscopy in oocytes of both species. Monkey and mouse oocytes responded to PGE2 as well as agonists selective for EP2 and EP4 receptors with elevated cAMP, consistent with previous identification of EP2 and EP4 as Gαs/adenylyl cyclase coupled receptors. Incubation of mouse GV stage oocytes with PGE2 delayed oocyte nuclear maturation in vitro, but PGE2 treatment did not alter the percentage of mouse oocytes that fertilized successfully. PGE2 treatment also decreased the percentage of monkey oocytes that resumed meiosis in vitro. In contrast with mouse oocytes, the percentage of monkey oocytes which fertilized in vitro was lower after treatment with PGE2. Monkey oocytes with intact cumulus showed delayed nuclear maturation, but fertilization rate was not affected by PGE2 treatment.</p> <p>Conclusions</p> <p>Monkey and mouse oocytes express functional PGE2 receptors. PGE2 acts directly at mammalian oocytes to delay nuclear maturation. Surrounding cumulus cells modulate the effect of PGE2 to alter subsequent fertilization.</p

Introduction to Environmental Science

This Grants Collection uses the grant-supported open textbook Introduction to Environmental Science from Georgia College and State University: http://oer.galileo.usg.edu/biology-textbooks/4/ This Grants Collection for Introduction to Environmental Science was created under a Round Two ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/biology-collections/1001/thumbnail.jp

A participatory process to build the competence profile of teachers in a network of Higher Education Institutions in the Latin America context

[ES] En este texto se presenta la experiencia realizada por un red de instituciones de educación superior (IUS) que operan en seis estados de Sudamérica. Para alcanzar el objetivo de pasar de una docencia centrada en la enseñanza a un estilo docente cuyo compromiso básico es el de propiciar un aprendizaje de calidad en los estudiantes, las universidades han definido un nuevo perfil del docente universitario. Esta acción tiene tres características, que se describen en el texto: la primera se refiere al perfil como el "producto" de una comunidad de pensamiento; la segunda, al "proceso participativo" de trabajo que ha permitido la construcción del perfil con los docentes, el personal administrativo y los referentes de los recursos humanos de cada universidad; la tercera se relaciona con los instrumentos y las tecnologías, utilizadas de manera integrada durante el proceso (el Ambiente Virtual de Aprendizaje Colaborativo basado en el web 2.0, el Human Resource Management, la video investigación, el e- portafolio). El proyecto - desarrollado a través de la R-A - ha tenido como finalidad la de definir una idea compartida de calidad de la enseñanza, de autoevaluación y de monitorear la calidad con planes de mejora continua. La experiencia es un resultado de una de investigación promovida por la Fundación Edulife Onlus.[EN] This paper presents the experience carried out by a confederation of Higher Education Institution (IUS) operating in six states of Latin America. To achieve the goal of new model of teaching and learning based on “learning process” and shift the paradigm of learning as “centered teaching”, the Higher Education Institution have defined a new profile of the university teachers. This action expresses three characteristics presented in this paper: the first refers at the profile as "product" of a Community of Thought; the second refers to "participated process", a working model that allowed the co-construction of the profile with the teachers, the administrative and the human resources staff of the universities; the third presents the tools and technologies used in integrated way (Virtual Collaborative Learning Environment based on Web 2.0, the human resource Management, video-research, e-portfolio). The project - developed by action-research - has defined a shared idea of teaching´ quality, researchbased and supported by tools that allow self-assessment of every teachers, to monitor the quality of universities, to develop plans of continuous improvement building a community of learning. There are presented some qualitative and quantitative data of research.Ellerani, PG.; Gil Mendoza, MJ.; Fiorese, L. (2012). Un proceso de construcción participada del perfil docente en una red de Instituciones de Educación Superior de América Latina. REDU. Revista de Docencia Universitaria. 10(2):121-147. https://doi.org/10.4995/redu.2012.6100OJS12114710