952 resultados para New Structures


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The purpose of this study was to (a) develop an evaluation instrument capable of rating students' perceptions of the instructional quality of an online course and the instructor’s performance, and (b) validate the proposed instrument with a study conducted at a major public university. The instrument was based upon the Seven Principles of Good Practice for Undergraduate Education (Chickering & Gamson, 1987). The study examined four specific questions. 1. Is the underlying factor structure of the new instrument consistent with Chickering and Gamson's Seven Principles? 2. Is the factor structure of the new instrument invariant for male and female students? 3. Are the scores on the new instrument related students’ expected grades? 4. Are the scores on the new instrument related to the students' perceived course workload? ^ The instrument was designed to measure students’ levels of satisfaction with their instruction, and also gathered information concerning the students’ sex, the expected grade in the course, and the students’ perceptions of the amount of work required by the course. A cluster sample consisting of an array of online courses across the disciplines yielded a total 297 students who responded to the online survey. The students for each course selected were asked to rate their instructors with the newly developed instrument. ^ Question 1 was answered using exploratory factor analysis, and yielded a factor structure similar to the Seven Principles.^ Question 2 was answered by separately factor-analyzing the responses of male and female students and comparing the factor structures. The resulting factor structures for men and women were different. However, 14 items could be realigned under five factors that paralleled some of the Seven Principles. When the scores of only those 14 items were entered in two principal components factor analyses using only men and only women, respectively and restricting the factor structure to five factors, the factor structures were the same for men and women.^ A weak positive relationship between students’ expected grades and their scores on the instrument was found (Question 3). There was no relationship between students’ perceived workloads for the course and their scores on the instrument (Question 4).^

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Climate change is one of the most important and urgent issues of our time. Since 2006, China has overtaken the United States as the world’s largest greenhouse gas (GHG) emitter. China’s role in an international climate change solution has gained increased attention. Although much literature has addressed the functioning, performance, and implications of existing climate change mitigation policies and actions in China, there is insufficient literature that illuminates how the national climate change mitigation policies have been formulated and shaped. This research utilizes the policy network approach to explore China’s climate change mitigation policy making by examining how a variety of government, business, and civil society actors have formed networks to address environmental contexts and influence the policy outcomes and changes. The study is qualitative in nature. Three cases are selected to illustrate structural and interactive features of the specific policy network settings in shaping different policy arrangements and influencing the outcomes in the Chinese context. The three cases include the regulatory evolution of China’s climate change policy making; the country’s involvement in the Clean Development Mechanism (CDM) activity, and China’s exploration of voluntary agreement through adopting the Top-1000 Industrial Energy Conservation Program. The historical analysis of the policy process uses both primary data from interviews and fieldwork, and secondary data from relevant literature. The study finds that the Chinese central government dominates domestic climate change policy making; however, expanded action networks that involve actors at all levels have emerged in correspondence to diverse climate mitigation policy arrangements. The improved openness and accessibility of climate change policy network have contributed to its proactive engagement in promoting mitigation outcomes. In conclusion, the research suggests that the policy network approach provides a useful tool for studying China’s climate change policy making process. The involvement of various types of state and non-state actors has shaped new relations and affected the policy outcomes and changes. In addition, through the cross-case analysis, the study challenges the “fragmented authoritarianism” model and argues that this once-influential model is not appropriate in explaining new development and changes of policy making processes in contemporary China.

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Since El Salvador’s civil war formally ended in 1992 the small Central American nation has undergone profound social changes and significant reforms. However, few changes have been as important or as devastating as the nation’s emergence as a central hub in the transnational criminal “pipeline” or series of recombinant, overlapping chains of routes and actors that illicit organizations use to traffic in drugs, money weapons, human being, endangered animals and other products. The erasing of the once-clear ideological lines that drove the civil war and the ability of erstwhile enemies to join forces in criminal enterprises in the post-war period is an enduring and dangerous characteristic of El Salvador’s transnational criminal evolution. Trained, elite cadres from both sides, with few legitimate job opportunities, found their skills were marketable in the growing criminal structures. The groups moved from kidnapping and extortion to providing protection services to transnational criminal organizations to becoming integral parts of the organizations themselves. The demand for specialized military and transportation services in El Salvador have exploded as the Mexican DTOs consolidate their hold on the cocaine market and their relationships with the transportista networks, which is still in flux. The value of their services has risen dramatically also because of the fact that multiple Mexican DTOs, at war with each other in Mexico and seeking to physically control the geographic space of the lucrative pipeline routes in from Guatemala to Panama, are eager to increase their military capabilities and intelligence gathering capacities. The emergence of multiple non-state armed groups, often with significant ties to the formal political structure (state) through webs of judicial, legislative and administrative corruption, has some striking parallels to Colombia in the 1980s, where multiple types of violence ultimately challenged the sovereignty of state and left a lasting legacy of embedded corruption within the nation’s political structure. Organized crime in El Salvador is now transnational in nature and more integrated into stronger, more versatile global networks such as the Mexican DTOs. It is a hybrid of both local crime – with gangs vying for control off specific geographic space so they can extract payment for the safe passage of illicit products – and transnational groups that need to use that space to successfully move their products. These symbiotic relationships are both complex and generally transient in nature but growing more consolidated and dangerous.

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Natural CO2 venting systems can mimic conditions that resemble intermediate to high pCO2 levels as predicted for our future oceans. They represent ideal sites to investigate potential long-term effects of ocean acidification on marine life. To test whether microbes are affected by prolonged exposure to pCO2 levels, we examined the composition and diversity of microbial communities in oxic sandy sediments along a natural CO2 gradient. Increasing pCO2 was accompanied by higher bacterial richness and by a strong increase in rare members in both bacterial and archaeal communities. Microbial communities from sites with CO2 concentrations close to today's conditions had different structures than those of sites with elevated CO2 levels. We also observed increasing sequence abundance of several organic matter degrading types of Flavobacteriaceae and Rhodobacteraceae, which paralleled concurrent shifts in benthic cover and enhanced primary productivity. With increasing pCO2, sequences related to bacterial nitrifying organisms such as Nitrosococcus and Nitrospirales decreased, and sequences affiliated to the archaeal ammonia-oxidizing Thaumarchaeota Nitrosopumilus maritimus increased. Our study suggests that microbial community structure and diversity, and likely key ecosystem functions, may be altered in coastal sediments by long-term CO2 exposure to levels predicted for the end of the century.

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The computational modeling of ocean waves and ocean-faring devices poses numerous challenges. Among these are the need to stably and accurately represent both the fluid-fluid interface between water and air as well as the fluid-structure interfaces arising between solid devices and one or more fluids. As techniques are developed to stably and accurately balance the interactions between fluid and structural solvers at these boundaries, a similarly pressing challenge is the development of algorithms that are massively scalable and capable of performing large-scale three-dimensional simulations on reasonable time scales. This dissertation introduces two separate methods for approaching this problem, with the first focusing on the development of sophisticated fluid-fluid interface representations and the second focusing primarily on scalability and extensibility to higher-order methods.

We begin by introducing the narrow-band gradient-augmented level set method (GALSM) for incompressible multiphase Navier-Stokes flow. This is the first use of the high-order GALSM for a fluid flow application, and its reliability and accuracy in modeling ocean environments is tested extensively. The method demonstrates numerous advantages over the traditional level set method, among these a heightened conservation of fluid volume and the representation of subgrid structures.

Next, we present a finite-volume algorithm for solving the incompressible Euler equations in two and three dimensions in the presence of a flow-driven free surface and a dynamic rigid body. In this development, the chief concerns are efficiency, scalability, and extensibility (to higher-order and truly conservative methods). These priorities informed a number of important choices: The air phase is substituted by a pressure boundary condition in order to greatly reduce the size of the computational domain, a cut-cell finite-volume approach is chosen in order to minimize fluid volume loss and open the door to higher-order methods, and adaptive mesh refinement (AMR) is employed to focus computational effort and make large-scale 3D simulations possible. This algorithm is shown to produce robust and accurate results that are well-suited for the study of ocean waves and the development of wave energy conversion (WEC) devices.

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Engaging Ireland’s rich heritages of traditional music, story-telling, song, dance, and language, this doctoral composition project is a unique undertaking in the amalgamation of native art forms and the narrative realisation of Irish legends. The centrepiece of the project comprises of two collections of compositions inspired by the legends Oidhe Chloinne Lir (the tragic fate of the children of Lir) and Loinges Mac nUislenn (the exile of the sons of Uisliu). An interdisciplinary approach of traditional research and creative practice was employed in the development of this project, which informed and supported the formulation of personal and distinctive recensions of the chosen narratives, and the composition of over three hundred new works. Grounded in Irish traditional music, the compositional voice speaks in the familiar styles and structures of the idiom, and also resonates in contemporary and singular spaces. The Irish harping tradition is continued and extended in this research through the composition and recording of new music which is particularly suited to the instrument. Outputs include contextual, critical, and creative writings, recordings, video materials, musical scores, and storyboard and performance design artwork.

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The commodification of natural resources and the pursuit of continuous growth has resulted in environmental degradation, depletion, and disparity in access to these life-sustaining resources, including water. Utility-based objectification and exploitation of water in some societies has brought us to the brink of crisis through an apathetic disregard for present and future generations. The ongoing depletion and degradation of the world’s water sources, coupled with a reliance on Western knowledge and the continued omission of Indigenous knowledge to manage our relationship with water has unduly burdened many, but particularly so for Indigenous communities. The goal of my thesis research is to call attention to and advance the value and validity of using both Indigenous and Western knowledge systems (also known as Two-Eyed Seeing) in water research and management to better care for water. To achieve this goal, I used a combined systematic and realist review method to identify and synthesize the peer-reviewed, integrative water literature, followed by semi-structured interviews with first authors of the exemplars from the included literature to identify the challenges and insights that researchers have experienced in conducting integrative water research. Findings suggest that these authors recognize that many previous attempts to integrate Indigenous knowledges have been tokenistic rather than meaningful, and that new methods for knowledge implementation are needed. Community-based participatory research methods, and the associated tenets of balancing power, fostering trust, and community ownership over the research process, emerged as a pathway towards the meaningful implementation of Indigenous and Western knowledge systems. Data also indicate that engagement and collaborative governance structures developed from a position of mutual respect are integral to the realization of a given project. The recommendations generated from these findings offer support for future Indigenous-led research and partnerships through the identification and examination of approaches that facilitate the meaningful implementation of Indigenous and Western knowledge systems in water research and management. Asking Western science questions and seeking Indigenous science solutions does not appear to be working; instead, the co-design of research projects and asking questions directed at the problem rather than the solution better lends itself to the strengths of Indigenous science.

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Cardiac tissue engineering (CTE) is currently a prime focus of research due to an enormous clinical need. In this work, a novel functional material, Poly(3-hydroxyoctanoate), P(3HO), a medium chain length polyhydroxyalkanoate (PHA), produced using bacterial fermentation, was studied as a new potential material for CTE. Engineered constructs with improved mechanical properties, crucial for supporting the organ during new tissue regeneration, and enhanced surface topography, to allow efficient cell adhesion and proliferation, were fabricated. Our results showed that the mechanical properties of the final patches were close to that of cardiac muscle. Biocompatibility of the P(3HO) neat patches, assessed using Neonatal ventricular rat myocytes (NVRM), showed that the polymer was as good as collagen in terms of cell viability, proliferation and adhesion. Enhanced cell adhesion and proliferation properties were observed when porous and fibrous structures were incorporated to the patches. Also, no deleterious effect was observed on the adults cardiomyocytes’ contraction when cardiomyocytes were seeded on the P(3HO) patches. Hence, P(3HO) based multifunctional cardiac patches are promising constructs for efficient CTE. This work will provide a positive impact on the development of P(3HO) and other PHAs as a novel new family of biodegradable functional materials with huge potential in a range of different biomedical applications, particularly CTE, leading to further interest and exploitation of these materials.

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The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cortés Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cortés Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is also interpreted here as rapid. More importantly, the contact between the Villar del Arzobispo and Aldea de Cortés Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cortés Fm, previously considered Valangian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cortés Fms.

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Several landforms found in the fold-and-thrust belt area of Central Precordillera, Pre-Andes of Argentina, which were often associated with tectonic efforts, are in fact related to non-tectonic processes or gravitational superficial structures. These second-order structures, interpreted as gravitational collapse structures, have developed in the western flank of sierras de La Dehesa and Talacasto. These include rock-slides, rock falls, wrinkle folds, slip sheets and flaps, among others; which together constitute a monoclinal fold dipping between 30º and 60º to the west. Gravity collapse structures are parallel to the regional strike of the Sierra de la Dehesa and are placed in Ordovician limestones and dolomites. Their sloping towards the west, the presence of bed planes, fractures and joints; and the lithology (limestone interbedded with incompetent argillaceous banks) would have favored their occurrence. Movement of the detached structures has been controlled by lithology characteristics, as well as by bedding and joints. Detachment and initial transport of gravity collapse structures and rockslides in the western flank of the Sierra de la Dehesa were tightly controlled by three structural elements: 1) sliding surfaces developed on parallel bedded strata when dipping >30° in the slope direction; 2) Joint’s sets constitute lateral and transverse traction cracks which release extensional stresses and 3) Discontinuities fragmenting sliding surfaces.  Some other factors that could be characterized as local (lithology, structure and topography) and as regional (high seismic activity and possibly wetter conditions during the postglacial period) were determining in favoring the steady loss of the western mountain side in the easternmost foothills of Central Precordillera.

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Many of the principles and indeed the rhetoric of New Public Management proved attractive to both politicians and senior bureaucrats across the developed world as a remedy for problems in policy processes. Ireland shares many features of its constitutional structures and political practices with Britain, Canada, Australia, New Zealand, all of them early and enthusiastic adopters of NPM. Some of the organizational and procedural changes in Irish public administration do indeed bear similarities to those we would expect to see as a result of adopting principles of NPM. However, we contend that surface impressions are misleading. Drawing on a time-series database of Irish state institutions, we show that organizational changes were not necessarily driven by NPM. The absence of strong political drivers meant that reform initiatives did not fundamentally alter the configuration of the Irish public administration. Many of the problems that NPM was intended to address are only now coming under scrutiny.

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Phyllomedusine frogs are an extraordinary source of biologically active peptides. At least 8 families of antimicrobial peptides have been reported in this frog clade, the dermaseptins being the most diverse. By a peptidomic approach, integrating molecular cloning, Edman degradation sequencing and tandem mass spectrometry, a new family of antimicrobial peptides has been identified in Cruziohyla calcarifer. These 15 novel antimicrobial peptides of 20–32 residues in length are named cruzioseptins. They are characterized by having a unique shared N-terminal sequence GFLD– and the sequence motifs –VALGAVSK– or –GKAAL(N/G/S) (V/A)V– in the middle of the peptide. Cruzioseptins have a broad spectrum of antimicrobial activity and low haemolytic effect. The most potent cruzioseptin was CZS-1 that had a MIC of 3.77 μM against the Gram positive bacterium, Staphylococcus aureus and the yeast Candida albicans. In contrast, CZS-1 was 3–fold less potent against the Gram negative bacterium, Escherichia coli (MIC 15.11 μM). CZS-1 reached 100% haemolysis at 120.87 μM. Skin secretions from unexplored species such as C. calcarifer continue to demonstrate the enormous molecular diversity hidden in the amphibian skin. Some of these novel peptides may provide lead structures for the development of a new class of antibiotics and antifungals of therapeutic use.

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Migrant labour has transformed local economies in many places, often helping to reverse long-term decline. The emergence of new immigrant destinations (NID) globally brings mixed opportunities for the individuals involved. This article uses empirical evidence, focusing on the workplace, to show the performance, construction and significance of migrant identity. By using social identity theory to examine what it means to be a ‘migrant’, it follows from Goffman’s overarching concern with social interactions and his promotion of microanalysis as analytical lenses.
The article reveals the ambiguity of the label ‘migrant’. It shows how the external application or internal enactment of migrant identities bestow particular status that represents an asset or an obstacle to integration. It can mean ‘hard working’, ‘less deserving’ and ‘exploitable’ and it also denotes ‘lazy’ and individuals. While some individuals assume the hard working migrant and ‘exploitable’ identity in certain circumstances because of the benefits that it brings, this status can also cause high levels of dissatisfaction and distress among migrants. The research shows how the creation of a migrant identity limits the structures and networks from which migrants may draw resources and in so doing curtails the possibilities for social change due to migration.

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Labour and capital mobility from globalisation has given rise to significant increases in the reliance of migrant labour in established gateways, but also in new migration destinations. Many aspects of migrant incorporation in new migration destinations have received some attention, not least regarding employer and employee relations. Less attention has been focused on the construction of migrant as a marker of identification, although identities, particularly regarding gender and ethnicity, in the workplace have received considerable attention. This article aims to illuminate knowledge on how migration produces social change thereby responding to a call from Batnitzky et al. (2009, p. 1290) for additional attention on what ‘the practical and symbolic effects of migration are as people move across different structures and institutions of social control….’ Mindful of Goffman’s (1969, 1983) emphasis on individual interactions and experiences, it examines what it means to be a migrant in terms of everyday encounters and experiences. It investigates the array and interplay of internal and external processes that create migrant identities and the implications of this for social integration.

The paper argues that one of the paradoxes of globalisation, and of the associated increased levels of migrant labour, is the construction of the migrant identity that ultimately impedes social integration. It shows how the application of migrant identity (internally and externally) bestows a particular status that affects (options for) individual behaviour and subsequent actions and outcomes. The paper argues that while migrants value the migrant identity status because of the benefits that it brings, this status can also cause high levels of dissatisfaction among migrants and it can exclude migrants from wider benefits of full citizenship. Migrants have individual identification processes, but external forces, including social structures and institutions, also affect migrant identity. These forces help to shape individual expectations and standards, contributing to identity interruption and dissonance.

The paper is structured as follows: it uses social identity theory as a means of understanding what it is to be a ‘migrant’ in a new destination, while simultaneously recognising the inevitability of this generic label - migrants are an extremely heterogeneous group, made up of individuals with different experiences, values and so forth. The analysis considers the significance of context and of social interactions, thus paying attention to how identity is constructed and performed by the individual and also assigned by others. Empirical evidence is used to examine how having a migrant status affects individual prospects. The paper evaluates the extent to which patterns and processes of migration present an opportunity for social change, positive or negative.

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In the near future, geopolymers or alkali-activated cementitious materials will be used as new high-performance construction materials of low environmental impact with a reasonable cost. This material is a good candidate to partially replace ordinary portland cement (OPC) in concrete as a major construction material that plays an outstanding role in the construction industry of different structures. Geopolymer materials are inorganic polymers based on alumina and silica units; they are synthesized from a wide range of dehydroxylated alumina-silicate powders condensed with alkaline silicate in a highly alkaline environment. Geopolymeric materials can be produced from a wide range of alumina-silica, including natural products--such as natural pozzolan and metakaolin--or coproducts--such as fly ash (coal and lignite), oil fuel ash, blast furnace or steel slag, and silica fume--and provide a route toward sustainable development. Using lesser amounts of calcium-based raw materials, lower manufacturing temperature, and lower amounts of fuel result in reduced carbon emissions for geopolymer cement manufacture up to 22 to 72% in comparison with portland cement. A study has been done by the authors to investigate the intrinsic nature of different types of Iranian natural pozzolans to determine the activators and methods that could be used to produce a geopolymer concrete based on alkali-activated natural pozzolan (AANP) and optimize mixture design. The mechanical behavior and durability of these types of geopolymer concrete were investigated and compared with normal OPC concrete mixtures cast by the authors and also reported in the literature. This paper summarizes the main conclusions of the research regarding pozzolanic activity, activator properties, engineering and durability properties, applications and evaluation of carbon footprint, and cost for AANP concrete.