High power, broadband light sources emitting in the 2-2.5 um wavelength range important for optical sensing of important biomolecules in aqueous solutions such as glucose. Here we demonstrate and analyze superluminescent diodes with output centered at 2.4 ums (range ~2.2-2.5 ums) from GaInAsSb/AlGaAsSb quantum wells in a separate confinement structure. Quasi-continuous wave output of 1 mW is achieved at room temperature for 40m x 2mm devices. Superluminescence is evidenced in superlinear growth, spectral narrowing, and angular narrowing of light output with increasing current injection. The output is analyzed and modeled with semiconductor rate equations, and by varying parameters, potential routes for future improvements are explored, such as additional Auger suppression and photonic mode engineering.

Changes in the demands on educational leaders have necessitated shifts in the roles and responsibilities of school principals. Meeting the needs of students with disabilities is among the critical challenges that administrators face today. The purpose of this study was to examine the lived experiences of elementary school principals where students with Specific Learning Disabilities (SLD) demonstrate reading proficiency. Phenomenological research was conducted to identify the themes associated with effective school leadership, related to this specific population, students with SLD. Informal, non evaluative observations were conducted in conjunction with analysis of leadership summaries that were submitted by teachers who were nominated by the participants, to determine theme congruence. These results indicated that the lived experiences of elementary school principals are a complex blend of characteristics and practices. Seven specific themes were identified in the qualitative interviews: 1) Embedded personal and/or professional experiences; 2) Adaptability; 3) Relationship orientation and commitment to collaboration; 4) Focused responsibility and accountability; 5) Hiring and supporting teachers while maintaining a culture of high expectations; 6) Resource allocation; 7) Reflection that informs decision making. This research provided preliminary evidence to demonstrate the lived experiences of elementary school principals, with a particular focus on students with SLD, and can be used to inform and adapt current practices to address anticipated challenges in the future.

Thesis advisor: Richard Jackson / A significant body of research has examined the impact of technology on pedagogy (Cuban, 1999; Enyedy, 2014), student achievement (Schachter, 1999; Cheung & Slavin, 2013, OECD, 2015), and equity (Reich, Murnane & Willett, 2012; Van Deursen & Van Dijk, 2011) with both positive and negative results within each domain. Research has also examined the impact of technology on the success of students with disabilities in various domains (Corn, Tagsold, & Argueta, 2012; Hargreaves & Braun, 2012; Harris & Smith, 2004; Penuel, 2006). However, no research has assessed the impact of one to one technology, in particular, on the self-efficacy of students with specific learning disabilities in educational settings. This dissertation examined the experience of nine middle school students with specific learning disabilities in the first year of a one to one laptop program. Among the guiding questions for this research was the following: What characteristics of 1:1 programs present particular challenges or opportunities for students with learning disabilities? A series of interviews with students, parents, and teachers, as well as pre and post-surveys gauging student self-efficacy, were organized within the frame of activity theory and analyzed using a case-study narrative approach. Findings from the research suggest the presence of several critical conditions that support student self-efficacy in this one to one program. These critical conditions include the presence of a culture of collaboration, putting the needs of teachers first in terms of comfort with technology, providing a system of professional development for both students and teachers, encouraging the philosophy of a growth mindset in relation to technology, and adopting a Universal Design for Learning (UDL) framework as a model for curriculum design that emphasizes equity through flexibility. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.

In order to study inlight ice adhesion at the droplet-scale, a strategy is presented to simulate the impact and solidification of a supercooled water droplet on a cooled substrate. Upon impact, nucleation is assumed to occur instantaneously, and properties of the droplet are chosen to account for the nucleation process. Simulations are performed in ANSYS Fluent using a coupled Volume of Fluid and Level-Set method to capture the air-water interface and an Enthalpy-Porosity method to capture the liquid-solid interface. Calibration of a simulation parameter, Amush, is performed in order to match experimental data for different surface types and surface temperatures. The calibrated simulation strategy is applied to low-speed, inlight icing conditions. The effects of surface variation and droplet diameter variation are investigated, providing insight into the icephobicity of superhydrophobic surfaces. Numerical results suggest that large droplets (approximately 200 micron-diameter) will freeze and adhere to a superhydrophobic surface.

Subclinical endotoxemia (low levels of circulating bacterial endotoxin) has been observed in patients suffering from chronic inflammatory diseases such as atherosclerosis, diabetes, and obesity. However, the link between this condition and chronic inflammation is poorly understood. Previous work from our lab has shown that chronic exposure to super-low doses of bacterial endotoxin (LPS) aggravates atherosclerosis resulting in increased plaque size and instability in a macrophage-dependent manner in a mouse model of atherosclerosis. Further, we showed that super-low dose LPS (SLD-LPS) treatment was able to inhibit lysosomal fusion in immortalized macrophages. However, this was done under more acute treatment conditions. The aim of this project was to examine the molecular mechanisms by which chronic SLD-LPS may polarize macrophages to a non-resolving pro-inflammatory state consistent with chronic inflammation. This was carried out in two projects, the first a more broad phenotypic paper showing the disruption in homeostasis by chronic SLD-LPS in immortalized macrophages, while the second uses primary bone marrow-derived mouse macrophages to identify specific molecular signaling pathways used by chronic SLD-LPS. Here we show that chronic SLD-LPS led to the novel upregulation of pro-inflammatory mediators p62 and ccl2 with simultaneous downregulation of homeostatic mediators Nrf2 and slc40a1 in immortalized wild-type mouse macrophages. Further we showed this effect was reversed using the homeostatic restorative agent sodium phenylbutyrate (4-PBA), a newly reported activity for this reagent in mouse macrophages. This indicated that a disruption in homeostasis, possibly involving autophagy, may be responsible for the non-resolving pro-inflammatory polarization of macrophages. Therefore, in our second project, we further explored the effect of chronic SLD-LPS treatment on the homeostatic arm of the response by focusing on the Nrf2 inhibitor Keap1. Here we show that chronic SLD-LPS results in an accumulation of Keap1 in mouse bone marrow-derived macrophages, an effect specific to chronic SLD-LPS, as high doses of LPS failed to induce Keap1. We suggest that this effect may be related to a disruption in lysosomal fusion as evidenced by accumulation of autophagy flux markers MLKL and p62. Further, we show that these effects are dependent on the non-traditional TLR4 adaptor TRAM, suggesting an alternative dose-dependent signaling pathway for LPS. Together this work identifies novel signaling mechanisms involved in non-resolving pro-inflammatory polarization of murine macrophages, providing new insight behind how chronic super-low dose LPS exposure may lead to chronic inflammation. / Doctor of Philosophy / Inflammation is the body's natural response to injury or insult and can be beneficial in certain contexts such as pathogen clearance. However, left un-checked, chronic inflammation can exacerbate or even lead to disease pathology, such as is the case with modern diseases such as atherosclerosis, obesity, diabetes, etc. Despite the high prevalence of these diseases, effective treatments and therapies are still lacking. Recently it was discovered that many patients suffering from chronic inflammatory diseases had low levels bacterial endotoxin (LPS) in their circulation, a condition referred to as subclinical endotoxemia. However, possible links between this condition and chronic inflammatory disease remain poorly understood. Using a mouse model of atherosclerosis, previous research from our lab showed that persistent exposure to super-low doses of bacterial endotoxin (similar to those observed in humans) lead to aggravated atherosclerosis with both increased plaque size and instability. Further, we showed that this effect was primarily mediated by pro-inflammatory polarized immune cells called macrophages, but the molecular mechanism behind this polarization is still unclear. Further research into these molecular mechanisms may provide better targets for the development of future chronic inflammatory disease treatments. Here using a combination of mouse cell line and primary cell cultures, we discuss how chronic exposure to super-low doses of bacterial endotoxin leads to the chronic non-resolving pro-inflammatory polarization of macrophage immune cells, with particular emphasis on the distinct molecular signaling mechanisms induced by chronic super-low dose LPS.

Many studies have investigated problems with the ability achievement discrepancy (AAD) method of diagnosing specific learning disabilities (SLDs). The definition of an SLD includes the presence of a deficit in one or more cognitive processing systems. Researchers in other studies found that the AAD method overdiagnoses English language learners and students from low socioeconomic backgrounds, and underdiagnoses students with cognitive processing deficits. Although SLD diagnostic methods have been widely researched, much less information is available regarding SLD diagnostic methods that predict important student outcomes, such as high school completion. The General Abilities Index (GAI) is an SLD diagnostic method that can identify cognitive processing deficits. This study examined the relationships between cognitive processing deficits and the GAI method, high school completion status, performance on state standards assessments, and SLD eligibility. Using a multivariate, nonexperimental design, this study analyzed 149 datasets from records of students tested for an SLD between 1996 to 2013. A GLM analysis found that several types of cognitive processing deficits predicted math and writing performance on the state standards assessment and predicted not being diagnosed with an SLD, while the GAI method failed to predict any relationship with the dependent variables. Positive social changes from this study may include improved SLD diagnostic practices and improved educational interventions that target the cognitive processing deficits. Improved educational outcomes for SLD persons may reduce the high rates of unemployment, substance abuse, and incarceration experienced by the adult SLD population.

Många aktörer i samhället har behov av geodata levererat från olika myndigheter med flera. Det är ofta nödvändigt att kombinera olika typer av geodata. Stilsättning av vektordata sker genom att tillsammans med rumsliga, geografiska data läsa in en separat stilfil som talar om hur ingående objekt ska presenteras. Fördelen med stilsatt vektordata är att det möjliggör för användaren att modifiera utseendet på ett visst objekt i kartbilden, till skillnad från när en WMS-tjänst används och användaren får ett förutbestämt utseende. Nackdelen med stilsatt vektordata är när data som levererats från olika aktörer ska kombineras. Geografiska informationssystem finns både som licensierade och som öppen källkod. Bland de stilsättningsformat som används i programvaror baserade på öppen källkod, är många format kompatibla och kan tolkas av olika system mer eller mindre korrekt. I detta examensarbete har data stilsatts i QGIS där stilfiler skapats genom användning av tre olika metoder. Stilfilerna exporterades för inläsning i GeoServer. Samtliga metoder användes för stilsättning av punkt-, linje- och polygonobjekt. Metod 1 användes för att spara stilfilen i QGIS i det OGC-standardiserade formatet SLD 1.1.0, vilket genererade det mest likartade resultatet vid visualisering. Resultatet vid stilsättning av punktobjekt visar på 73 % överensstämmelse, linjeobjekt 56 % och polygoner 42 %. Metod 2, innebar en export av stilfilen via insticksprogrammet GeoServer Explorer vilket genererade det OGC standardiserade formatet SLD 1.0.0. Resultatet visar att en mängd olika parametrar för att beskriva stilsättningen inte tolkas i GeoServer samt att storleken för objekten i regel fyrdubblades. Resultatet för punktobjekten visar  54 % överensstämmelse, linjeobjekten 44 % och polygonerna 53 %. Metod 3 utfördes genom att exportera QGIS stilsättning via insticksprogrammet Lib-mapboxgl-qgis, och därmed generera stilsättningen i MBstyle-format. Punktobjekten, som visualiserades via en PNG-fil, resulterar i en likartad överensstämmelse på 62 %. Linjeobjekten som testades var tre enkla linjer, skapade enbart för test i MBstyle, eftersom mer avancerad stilsättning inte valideras vid export. Dessa tre linjer klassades som ”Liknande", med någon defekt vilket genererade 67 % överensstämmelse. Polygonerna i MB-style visar på ett icke-likartat visuellt resultat. Samtliga polygoner visualiseras enbart med en solid fyllning (som inte alltid stämmer överens färgmässigt) och kantlinje. Polygonernas överensstämmelse är 39 %. Stickprovsmodifiering utfördes i syfte att undersöka möjligheten att skapa en stilfil som genererar ett likartat visuellt resultat med den ordinarie stilsättningen i QGIS. Modifiering gjordes enbart på de två SLD-versionerna. Metod 1 genererade en mer detaljerad översättning där fler parametrar medföljde. Metod 2 översatte stilsättning med font till en markör utan detaljerat innehåll, vilket resulterade i att en standardstilsättning applicerades. / Many actors in society need geodata delivered from, among others, governmental agencies. Often there is also the need to combine data from different sources. Style of vector data is visualized, in conjunction with geodata, using a separate style file that describes how each object will be presented. The advantage is the ability to retrospectively modify the appearance of a particular object in the map image, unlike when a WMS service is applied, and the user gets a predetermined look that cannot be changed. However, the disadvantages of styled vector data are obvious when combining geodata from different providers, who uses different systems. GIS software are available as both licensed and open source. Among the style formats used in open source software, many are compatible with each other and can be interpreted in different systems. Having said that, this does not always work seamlessly. In this thesis QGIS was used. The style file was exported to GeoServer using three different methods. In all methods included styling of point, line and polygon objects. Using method 1, the style file imported in QGIS in the OGC standard format SLD 1.1.0, this generated the most similar result for the visualization. The result for the point features shows 81 %, the line features 56 % and the polygon features 47 % similarity. Using method 2, the style file was imported in the GeoServer Explorer plugin, generated the OGC standard format SLD 1.0.0. The result shows that a variety of parameters for describing the style are not interpreted correctly and the size of the objects is consistently quadrupled. The result for the point features shows 58 % similarity, the line features 39 % and the polygon features 44 % similarity. Using method 3, the QGIS styling was exported via the Lib-mapboxgl-qgis plugin, thus generating the style in MBstyle format. The point features, which were visualized through a PNG file and results shows 62 % similarity. The line features were tested with three simple line features created only for the MBstyle test, as more advanced styling was not validated during export. The three lines were classified as similar with some kind of defect, giving 67 % similarity. Polygon features in MBstyle showed a non-similar visual result. All polygons were visualized with only a solid fill and a stroke, which did not even appear in correct color. The similarity of the polygons was measured as 39 %. However, this relatively high percentage is due to the fact that the chosen judgement criteria rewards points for simply generating a visual output. The purpose with the sampling modification was to investigate whether it was possible to create a style file that generated a similar visual result as the original style in QGIS. Modification was made only to the two SLD versions. The differences between the methods and styles in the different versions turned out to depend on how the styles were translated. Method 1 generated a more detailed translation with more parameters included, such as reference to a font. Method 2 translated a font style to a Mark without detailed content, resulting in that a default setting was applied.

According to the UNICEF report, up to ten percent of children in the world have affected specific learning disabilities (SLD) and the majority of these children are educated in general education classrooms. An important resource for children with learning disabilities to flourish in the classroom is access to assistive technology. To prepare children on how to utilize assistive technology in the learning environment is important for teachers. This systematic review focused on teacher perspectives on assistive technology regarding children with SLD. Six scholarly articles were used for this study. The information drawn from the articles showed that teachers are receptive to assistive technology in their classrooms. They perceived assistive technology as an important supportive device for improving the vital skills of reading and writing comprehension. However, it is clear from their perspectives that the teachers needed more support than they were able to access in order to feel comfortable to implement and use assistive technology in the classroom. Therefore the need for professional development and training and the integration of appropriate technical devices are vital to enhance the development of children with SLD. Future research will be focus on how pre-service teachers are being prepared for AT use as a part of their pre-service training program and professional development.

Studies show that the microstructure of the fine aggregate matrix has a significant influence on the mechanical properties and evolution of damage in an asphalt mixture. However, very little work has been done to quantitatively characterize the microstructure of the asphalt binder within the fine aggregate matrix of asphalt mixtures. The first objective of this study was to quantitatively characterize the three dimensional microstructure of the asphalt binder within the fine aggregate matrix (FAM) of an asphalt mixture and compare the influence of binder content, coarse aggregate gradation, and fine aggregate gradation on this microstructure. Studies indicate that gradation of the fine aggregate has the most influence of the degree of anisotropy whereas gradation of the coarse aggregate has the most influence on the direction anisotropy of the asphalt mastic within the fine aggregate matrix. Addition of asphalt binder or adjustments to the fine aggregate gradation also resulted in a more uniform distribution of the asphalt mastic within the fine aggregate matrix. The second objective of this study was to compare the internal microstructure of the mortar within a full-scale asphalt mixture to the internal microstructure of the FAM specimen and also conduct a limited evaluation of the influence of mixture properties and methods of compaction on the engineering properties of the FAM specimens. Fatigue cracking is a significant form of pavement distress in flexible pavements. The properties of the sand-asphalt mortars or FAM can be used to characterize the evolution of fatigue crack growth and self-healing in full-scale asphalt mixtures. The results from this study, although limited in number, indicate that in most cases the SGC (Superpave Gyratory Compactor) compacted FAM specimen had a microstructure that most closely resembled the microstructure of the mortar within a full-scale asphalt mixture. Another finding from this study was that, at a given level of damage, the healing characteristic of the three different types of FAM mixes evaluated was not significantly different. This indicates that the healing rate is mostly dictated by the type of binder and not significantly influenced by the gradation or binder content, as long as the volumetric distribution of the mastic was the same. / text

The effects of Sr90 beta radiation and Co60 gamma radiation on the operation of EEV buried channel charge coupled devices (CCDs) have been studied. This work was instigated by the need to qualify CCDs for the SLD vertex detector. However, the work is also relevant to other small signal, low noise applications. The results of the batch qualification are presented and the data base of ionising radiation effects on EEV CCDs has been extended to include the effects of irradiation whilst clocking at 180K. Particular attention has been aimed at investigating the charge transfer degradation due to low levels of bulk defects. The measured energy level, capture cross section and introduction rate of the main radiation induced defect agrees well with published results for the Si-E centre. Annealing studies are also presented. A model for the charge transfer degradation is proposed. This includes the effects of temperature, readout rate, signal density and irradiation type and energy. Observations are also presented on the effect of irradiation on the noise characteristics of the single stage output circuit. For low noise applications the output is run in buried channel mode. In this mode the increase in noise is dominated by the change in the operating point of the output MOSFET.