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The first enantioselective decarboxylative Negishi-type alkylations of a-oxy carboxylic acids is reported via the intermediacy of redox-active esters (RAEs). This transformation enables a radical-based retrosynthesis of seemingly trivial enantiopure dialkylcarbinols. This article includes a discussion of the history of such couplings, the retrosynthetic ramifications of such a coupling, the development of general conditions, and an extensive series of applications that vividly demonstrate how it can simplify synthesis.

The polar retrosynthetic analysis has been widely employed in the field of organic synthesis and forms the basis of undergraduate curriculum. Although most reactions in organic synthesis rely on this rubric to guide their strategic application, their implementation often requires a long list of ancillary considerations to mitigate chemoselectivity and oxidation state issues involving protecting groups and precise reaction choreography. Here we demonstrate a complete departure from this norm by the use of a radical based Ni/Ag-electrocatalytic cross coupling of α-substituted carboxylic acids, thereby enabling an intuitive and modular approach to accessing complex molecular architectures. This new method relies on a key silver additive that forms an active Ag-nanoparticle coated electrode surface in situ along with carefully chosen ligands that modulate the reactivity of Ni. Through judicious choice of conditions and ligands, the cross-couplings can be rendered highly diastereoselective. To demonstrate the simplifying power of these reactions, exceedingly concise syntheses of 14 natural products and two medicinally relevant molecules were completed.

Small‐molecule stabilization of protein–protein interactions (PPIs) is a promising concept in drug discovery, however the question how to identify or design chemical starting points in a “bottom‐up” approach is largely unanswered. We report a novel concept for identifying initial chemical matter for PPI stabilization based on imine‐forming fragments. The imine bond offers a covalent anchor for site‐directed fragment targeting, whereas its transient nature enables efficient analysis of structure–activity relationships. This bond enables fragment identification and optimisation using protein crystallography. We report novel fragments that bind specifically to a lysine at the PPI interface of the p65‐subunit‐derived peptide of NF‐κB with the adapter protein 14‐3‐3. Those fragments that subsequently establish contacts with the p65‐derived peptide, rather than with 14‐3‐3, efficiently stabilize the 14‐3‐3/p65 complex and offer novel starting points for molecular glues., A novel concept for optimizing orthosteric protein–protein interaction (PPI) stabilization is reported. Increasing interactions with the protein partner that contributes less to the composite binding pocket of the stabilizer (NF‐κB, red surface) results in increased stabilization, whereas further enhancing the interaction with the dominant partner protein (14‐3‐3, white surface) does not contribute to the stabilizing effect.

Recent studies show that the exploration of ways to involve students in effective bi/multilingual science education is gaining attention at all educational levels. Introducing students to the construction of bilingual scientific argument maps – visual representations of scientific argument structure using two languages – contributes to the quality of bilingual science education as they are a key aspect of bilingual scientific literacy; however, very little is known about how to promote the construction of these maps in bilingual science courses. Here we provide evidence for the claim that peer feedback and instructor feedback can be integrated to support the construction of bilingual scientific argument maps. A pedagogical strategy that integrates both peer feedback and instructor feedback was implemented in a university bilingual science course with 29 students (23 females and 6 males, 18–24 years-old) in Colombia. Results show that the strategy effectively supported the construction of scientific argument maps in Spanish and English. Implications for research and practice are discussed.

Most smarthome and smartphone technologies are designed with younger adults in mind, even though many older adults can benefit greatly from their use. Through our examination of how to make these technologies more accessible to adults aging in place with mobility impairments, we have found remote troubleshooting to be a possible solution to many problems. However, we have found most current teleconferencing solutions to be lacking in the limited perspectives of a single webcam, as well as from a lack of ability to point out specific items and locations within a camera view. As such, Our team developed a prototype system that used multiple desk space and room space views, as well as on screen annotations, to facilitate remote troubleshooting and social interactions through a teleconferencing service. This prototype was then evaluated with adults aging in place with mobility impairments, as well as accessibility experts, in order to see what parts of the system could be utilized for troubleshooting, as well as to see where the system was lacking. The studies tested the system’s ability to be used for troubleshooting, as well as their uses in games and social interactions. We have gathered positive feedback for these prototypes in the areas of troubleshooting, socialization, games, and for use in other accessibility studies. From these results, we have begun development of a mobile deployment kit for use of our teleconferencing solution in other accessibility studies.

We recently developed a molecule (GT-73) that blocked leukocyte transendothelial migration from blood to the peripheral tissues, supposedly by affecting the platelet endothelial cell adhesion molecule (PECAM-1) function. GT-73 was tested in an LPS-induced acute respiratory distress syndrome (ARDS) mouse model. The rationale for this is based on the finding that the mortality of COVID-19 patients is partly caused by ARDS induced by a massive migration of leukocytes to the lungs. In addition, the role of tert-butyl and methyl ester moieties in the biological effect of GT-73 was investigated. A human leukocyte, transendothelial migration assay was applied to validate the blocking effect of GT-73 derivatives. Finally, a mouse model of LPS-induced ARDS was used to evaluate the histological and biochemical effects of GT-73. The obtained results showed that GT-73 has a unique structure that is responsible for its biological activity, two of its chemical moieties (tert-butyl and a methyl ester) are critical for this effect. GT-73 is a prodrug, and its lipophilic tail covalently binds to PECAM-1 via Lys536. GT-73 significantly decreased the number of infiltrating leukocytes in the lungs and reduced the inflammation level. Finally, GT-73 reduced the levels of IL-1β, IL-6, and MCP-1 in bronchoalveolar lavage fluid (BALF). In summary, we concluded that GT-73, a blocker of white blood cell transendothelial migration, has a favorable profile as a drug candidate for the treatment of ARDS in COVID-19 patients.

Protein-protein modulation has emerged as a proven approach to drug discovery. While significant progress has been gained in developing protein-protein interaction (PPI) inhibitors, the orthogonal approach of PPI stabilization lacks established methodologies for drug design. Here, we report the systematic ″bottom-up″ development of a reversible covalent PPI stabilizer. An imine bond was employed to anchor the stabilizer at the interface of the 14-3-3/p65 complex, leading to a molecular glue that elicited an 81-fold increase in complex stabilization. Utilizing protein crystallography and biophysical assays, we deconvoluted how chemical properties of a stabilizer translate to structural changes in the ternary 14-3-3/p65/molecular glue complex. Furthermore, we explore how this leads to high cooperativity and increased stability of the complex.

Protein-protein interactions (PPIs) are at the core of regulation mechanisms in biological systems and consequently became an attractive target for therapeutic intervention. PPIs involving the adapter protein 14-3-3 are representative examples given the broad range of partner proteins forming a complex with one of its seven human isoforms. Given the challenges represented by the nature of these interactions, fragment-based approaches offer a valid alternative for the development of PPI modulators. After having assembled a fragment set tailored on PPIs' modulation, we started a screening campaign on the sigma isoform of 14-3-3 adapter proteins. Through the use of both mono-and bi-dimensional nuclear magnetic resonance spectroscopy measurements, coupled with differential scanning fluorimetry, three fragment hits were identified. These molecules bind the protein at two different regions distant from the usual binding groove highlighting new possibilities for selective modulation of 14-3-3 complexes.

The global COVID-19 pandemic forced all large in-person events to pivot to virtual or online platforms. IEEEVR2020 coincided with rising concerns and restrictions on travel and large gatherings, becoming one of the first academic conferences to rapidly adapt its programming to a completely virtual format. The global pandemic provided an impetus to re-examine the possibility of holding social interactions in virtual worlds. This article aims to: (1) revisit the issues of virtual conferences noted in earlier studies, focusing specifically on academic conferences, (2) introduce new survey and observational data from the recent IEEEVR2020 conference, and (3) present insights and future directions for virtual conferences during and after the COVID-19 pandemic. Findings from a field observation during the conference and a post-conference survey point to complex relationships among users, media platforms selected, and social constraints during the virtual conference.

Despite the highly strained nature of cyclopropanes possessing three vicinal quaternary carbon stereocenters, the regio- and diastereoselective copper-catalyzed carbomagnesiation reaction of cyclopropenes provides an easy and efficient access to these novel persubstituted cyclopropyl cores with a complete regio- and diastereoselectivity.

Working or WERKing on a wearable technology project in a transdisciplinary group can be an effective way of learning new skills and collaboration techniques. This paper describes a case study of running a wearable technology group project within an undergraduate course entitled Wearable Technology and Society. The computational media students in the class collaborated with outside performance artists (drag queens and a street dancer) to create interactive performance garments. Design methods such as the use of boundary objects aided in communication of ideas and cooperation across disciplines and cultural barriers. The requirement that the interactive garment function appropriately in a real performance lent urgency and gravity to the experience, motivating cohesive and expedited problem solving in the transdisciplinary group. The use of these methods on a project with real world outcomes and consequences facilitated an authentic learning experience for the students involved.

The serine/threonine kinase, GSK-3, is a promising drug discovery target for treating multiple pathological disorders. Most GSK-3 inhibitors that were developed function as ATP competitive inhibitors, with typical limitations in specificity, safety and drug-induced resistance. In contrast, substrate competitive inhibitors (SCIs), are considered highly selective, and more suitable for clinical practice. The development of SCIs has been largely neglected in the past because the ambiguous, undefined nature of the substrate-binding site makes them difficult to design. In this study, we used our previously described structural models of GSK-3 bound to SCI peptides, to design a pharmacophore model and to virtually screen the &ldquo, drug-like&rdquo, Zinc database (~6.3 million compounds). We identified leading hits that interact with critical binding elements in the GSK-3 substrate binding site and are chemically distinct from known GSK-3 inhibitors. Accordingly, novel GSK-3 SCI compounds were designed and synthesized with IC50 values of~1&ndash, 4 &mu, M. Biological activity of the SCI compound was confirmed in cells and in primary neurons that showed increased &beta, catenin levels and reduced tau phosphorylation in response to compound treatment. We have generated a new type of small molecule GSK-3 inhibitors and propose to use this strategy to further develop SCIs for other protein kinases.

Chemical chaperones prevent protein aggregation. However, the use of chemical chaperones as drugs against diseases due to protein aggregation is limited by the very high active concentrations (mm range) required to mediate their effect. One of the most common chemical chaperones is 4-phenylbutyric acid (4-PBA). Despite its unfavorable pharmacokinetic properties, 4-PBA was approved as a drug to treat ornithine cycle diseases. Here, we report that 2-isopropyl-4-phenylbutanoic acid (5) has been found to be 2-10-fold more effective than 4-PBA in several in vitro models of protein aggregation. Importantly, compound 5 reduced the secretion rate of autism-linked Arg451Cys Neuroligin3 (R451C NLGN3).

We report the synthesis of substituted indolizidines and quinolizidines using the modified Julia olefination previously developed on imides. The study focuses on the regioselectivity of this reaction on unsymmetrically substituted imides. The scope and regioselectivity of the reaction are presented here, and its utility as a tool for synthesizing natural products is demonstrated through the total synthesis of Pandalizine A.

We are grateful to the participants of the PEN-CAFoRR COST action, who have so far warmly welcomed this experiment by signing up to establishing local sites, and we look forward to ful filling this collaboration. We thank A. Palma, J. Oliet and T. Mora´n for suggestions on improv ing this protocol., The choice of revegetating via direct seeding or planting nursery-grown seedlings influences the potential stresses suffered by seedlings such as herbivory and drought. The outcome of the balance between both revegetation methods may ultimately depend on how species identity and traits such as seed and seedling size interact with environmental conditions. To test this, we will conduct a continental-scale experiment consisting of one mini-experiment replicated by multiple participants across Europe. Each participant will establish a site with seeded and planted individuals of one or more native, locally growing oak (Quercus) species; the selection of this genus aims to favour continental-scale participation and to allow testing the response of a widely distributed genus of broad ecological and economic relevance. At each site, participants will follow the present protocol for seed collection, seeding in the field, nursery cultivation, outplanting, protection against herbivores, site maintenance, and measurement of seedling performance and environmental variables. Each measurement on each species at each site will produce one effect size; the data will be analysed through mixed-effects meta-analysis. With this approach we will assess the main effect of revegetation method, species, plant functional traits, and the potential effect of site-specific effect moderators. Overall, we will provide a continental-scale estimate on the seeding vs. planting dilemma and analyse to what extent the differences in environmental conditions across sites, seed size, functional traits, and the phylogenetic relatedness of species can account for the differences in the effect of revegetation method on seedling performance across study sites and species., This collaborative experiment lacks specific funding and was designed to be as small, low-cost, and easy-to-implement as possible for each participant. The resources necessary to establish and monitor each experimental site as described in this document will be made available by each participant. Funding for the coordination of this experiment is available from grant RTI2018- 096187-J-100 from FEDER/ Spanish Ministry of Science, Innovation and Universities. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Video games offer conceptual examples of future technologies and provide interactive contexts in which these technologies can be designed, tested, and evaluated. Human-Computer Interaction (HCI) has been an integral part of video games since their inception, as it offers interface designers and technology developers a platform by which they can build scenarios and interactive prototypes to engage players. Real-world and game-world technologies draw from each other and lend themselves to evaluation through the lens of human-computer interaction paradigms. This paper seeks to provide further evidence supporting the relevance of HCI principles for evaluating general video game and in-game world technologies, and to establish a set of frameworks through which technologists can examine future technology concepts in video games, often in the form of science fiction artifacts and systems.

While many digital asset management platforms and digital libraries exist, most have been designed for technically savvy users and not the older adults who are a key audience for our Digital Drawer platform. In the domain of digital humanities collections, our project is significant in that we are utilizing a participatory design (PD) process wherein all of the stakeholders and potential users of a system are actively involved in the design process to help insure the result meets their needs and is usable. This paper presents a case study on the PD process and the challenges of designing a crowd-sourced media and metadata submission tool for the Historic Rural Churches of Georgia to accommodate older adult users with low technical savvy and disabilities. We report on the PD process to design the user interface and user experience (UI/UX) for this user demographic, present conclusions and plans for future work.

Video games are enjoyed as creative, emotional, and social outlets for many. However, for a growing number of people with disabilities and/or those acquiring disabilities due to age-related decline, this kind of media is becoming inaccessible. The future of accessible game design hinges on teaching the next generation of game developer professionals of best practices and providing them experience to create their own accessible games. Still, little is known for effective pedagogic practices that instill domain knowledge and awareness in students on accessibility design. In this early work, researchers explore the impact of one 60-min accessibility lecture on the way student participants sonified a game for those with visual impairments. Results indicate that students receiving the lecture produced a more accessible product for player with visual impairments, while also intimating higher levels of empathy for those with disabilities. Based on these findings, we present recommendations for how instructors can implement a minimum viable pedagogic intervention for accessible game design, if a longer engagement with this material is not possible.

Mild cognitive impairment (MCI) affects millions of older Americans and progression to dementia is common. Although people with MCI may experience impairments, they are often highly verbal, able, and eager to uphold beloved routines. Moreover, many seek opportunities to stay active, physically and mentally, to support their brain health. Some forms of cognitive training and social engagement potentially delay the onset and progression of disease, including dementia. This 12-month project used mixed methods to co-design and test an accessible version of well-known board games for people with MCI and a care partner without MCI. The overall goal was to foster a meaningful, joyous, social activity for players with differing capabilities using adapted game mechanics to create a compelling experience for both players. Coping strategies of care partners were studied to learn ways to foster positive interactions. Findings inform recommendations for game design and clinical interventions. Part of a symposium sponsored by Technology and Aging Interest Group.

Pancreatic β-cell membranes and presynaptic areas of neurons contain analogous protein complexes that control the secretion of bioactive molecules. These complexes include the neuroligins (NLs) and their binding partners, the neurexins (NXs). It has been recently reported that both insulin secretion and the proliferation rates of β-cells increase when cells are co-cultured with full-length NL-2 clusters. The pharmacological use of full-length protein is always problematic due to its unfavorable pharmacokinetic properties. Thus, NL-2-derived short peptide was conjugated to the surface of polyamidoamine-based (PAMAM) dendrimers. This nanoscale composite improved β-cell functions in terms of the rate of proliferation, glucose-stimulated insulin secretion (GSIS), and functional maturation. This functionalized dendrimer also protected β-cells under cellular stress conditions. In addition, various novel peptidomimetic scaffolds of NL-2-derived peptide were designed, synthesized, and conjugated to the surface of PAMAM in order to increase the biostability of the conjugates. However, after being covered by peptidomimetics, PAMAM dendrimers were inactive. Thus, the original peptide-based PAMAM dendrimer is a leading compound for continued research that might provide a unique starting point for designing an innovative class of antidiabetic therapeutics that possess a unique mode of action.

Video games have great value for collecting rich data that can be used to study fundamental research questions in fields such as psychology and human-computer interaction. There is an increased use of games as scientific tools to assess and train the cognitive, as well as non-cognitive traits and abilities of players. However, games designed as research tools have a unique and challenging set of considerations so that they meet both the requirements of a scientific protocol, while also maintaining an acceptable gaming experience. Additionally, the success of a research game requires extensive planning and co-creation support for trans-disciplinary teams. This paper describes five critical considerations for the design and implementation of custom-built games as scientifically valid and reliable experimental test beds. These findings resulted from several years of work creating game artifacts to study cognitive training and assessment of individual differences. This class of games presents unique design challenges that are often at odds with traditional game design conventions. However, there are many promising applications and use cases for thoughtfully instrumented games that are capable of generating data with comparable accuracy to traditional and previously validated measures.

LE MONSTRE is a responsive performance garment, changing the sound and projection of the performance space through audience interaction. As the audience is invited to investigate the garment through touch and pull, capacitive and resistive strain sensors relay the interaction as wifi MIDI signals. The garment was designed as an investigation into the technology and arts collaborative design process.

A series of novel polycyclic aromatic compounds that augment the rate of glucose uptake in L6 myotubes and increase glucose-stimulated insulin secretion from beta-cells were synthesized. Designing these molecules, we have aimed at the two main pathogenic mechanisms of T2D, deficient insulin secretion and diminished glucose clearance. The ultimate purpose of this work was to create a novel antidiabetic drug candidate with bi-functional mode of action. All presented compounds were synthesized, and characterized in house. INS-1E cells and L6 myoblasts were used for the experiments. The rate of glucose uptake, mechanism of action, level of insulin secretion and the druggability of the lead compound were studied. The lead compound (6-(1,3-dithiepan-2-yl)-2-phenylchromane), dose- and time-dependently at the low μM range increased the rate of glucose uptake in L6 myotubes and insulin secretion in INS-1E cells. The compound exerted its effects through the activation of the LKB1 (Liver Kinase B1)-AMPK pathway. In vitro metabolic parameters of this lead compound exhibited good druggability. We anticipate that bi-functionality (increased rate of glucose uptake and augmented insulin secretion) will allow the lead compound to be a starting point for the development of a novel class of antidiabetic drugs.

Leukocyte transendothelial migration is one of the most important step in launching an inflammatory immune response and chronic inflammation can lead to devastating diseases. Leukocyte migration inhibitors are considered as promising and potentially effective therapeutic agents to treat inflammatory and auto-immune disorders. In this study, based on previous trioxotetrahydropyrimidin based integrin inhibitors that suboptimally blocked leukocyte adhesion, twelve molecules with a modified scaffold were designed, synthesized, and tested in vitro for their capacity to block the transendothelial migration of immune cells. One of the molecules, namely, methyl 4-((2-(tert-butyl)-6-((2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) methyl) phenoxy) methyl) benzoate, (compound 12), completely blocked leukocyte transendothelial migration, without any toxic effects on immune or endothelial cells (IC50 = 2.4 µM). In vivo, compound 12 exhibited significant therapeutic effects in inflammatory bowel disease (IBD)/Crohn’s disease, multiple sclerosis, fatty liver disease, and rheumatoid arthritis models. A detailed acute and chronic toxicity profile of the lead compound in vivo did not reveal any toxic effects. Such a type of molecule might therefore provide a unique starting point for designing a novel class of leukocyte transmigration blocking agents with broad therapeutic applications in inflammatory and auto-immune pathologies.

Internet of Things (IoT) devices (including smart thermostats, lightbulbs, and door locks) have the potential to greatly enhance independence and promote aging-in-place among older adults with mobility disabilities. However, these devices require extensive information technology expertise to select, configure, use, and adapt to meet one’s needs and this creates considerable barriers to their adoption, acceptance, and utilization. Meanwhile, increasingly available consumer augmented reality (AR) technologies can enable individuals to experience how IoT function and are used within the context of one’s own abilities and home. This may provide potential users an effective means of overcoming barriers to adoption, acceptance, and utilization of IoT to support aging in place. We present preliminary results from a participatory design study of older adults with mobility disabilities on the use of AR on a smart phone device to support IoT understanding.

I intend to contribute to the knowledge base about the nature of mistrust as a social construct. My inquiry includes an unpacking of the construct of mistrust from the construct of trust based in the current literature. Once situated, I undertook a semiotic study of empirical data about the construct of mistrust based on the experiences of stakeholders in a local nonprofit organization as events unfolded during a 9-month period from August 2018 until April 2019. Applying repeated iterations of the data I constructed a contextualized thick description of mistrust. The findings of the study impact the common sense and didactic interpretations of mistrust. Practitioners of social change can apply the results to expand available strategies to mitigate mistrust and reduce the stresses that compromise the resources available to their communities and organizations to fulfill their objectives.

People now have access to many sources of data about their health and wellbeing. Yet, most people cannot wade through all of this data to answer basic questions about their long-term wellbeing: Do I gain weight when I have busy days? Do I walk more when I work in the city? Do I sleep better on nights after I work out? We built the Health Mashups system to identify connections that are significant over time between weight, sleep, step count, calendar data, location, weather, pain, food intake, and mood. These significant observations are displayed in a mobile application using natural language, for example, “You are happier on days when you sleep more.” We performed a pilot study, made improvements to the system, and then conducted a 90-day trial with 60 diverse participants, learning that interactions between wellbeing and context are highly individual and that our system supported an increased self-understanding that lead to focused behavior changes.

Over ten years ago, we created a novel dramatic augmented reality (AR) experience exploring bias and point-of-view (PoV) based upon the classic film “Twelve Angry Men,” which allowed a user to experience a dramatic jury room deliberation from the PoV of each of four different characters. Recently, informed by this previous work, we have created a new AR platform for engaging users in different PoVs, exposing forms of biases, and studying cultural conflicts. We are currently using this system for training and assessment in two domains: healthcare and psychological studies of terrorism. In this paper we present the requirements we have identified for this type of user experience, the co-design of both AR environments with domain experts, and the results of an initial user study of technology acceptance that yielded positive feedback from participants.

Board Member Perceptions of Nonprofit Organization Effectiveness by Laura Levy Maurer MA, New York University, 1973 BS, Cornell University, 1970 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Human Services Walden University August 2014 Abstract In contemporary American society, the nonprofit board is accountable for ensuring that an organization has sufficient resources to carry out its mission. Filling the gap between demands for services and the resources to meet them is often a struggle for small, local nonprofit organizations. This hermeneutic phenomenological study examined how boardIn contemporary American society, the nonprofit board is accountable for ensuring that an organization has sufficient resources to carry out its mission. Filling the gap between demands for services and the resources to meet them is often a struggle for small, local nonprofit organizations. This hermeneutic phenomenological study examined how board members of small, local nonprofits in the focal community perceive organizational effectiveness. Understanding the nature of nonprofit organization effectiveness according to board members contributes to understanding how those accountable meet their organizational objectives. A review of the literature revealed that nonprofit effectiveness involves the action of contributing and the motivation behind the action, both of which are associated with trust and reciprocity. Guided by social constructivism, this study employed a qualitative analysis of repeated iterations of semiotic data from board members (n = 30) and text analysis of organizational mission statements (n = 21), generating thick descriptions of the board members’ understanding of effectiveness. Findings were derived from successive coding iterations starting with the raw data, through locating text related to specific codes, to verifying relationships among codes, and incorporating researcher reflection. The analysis revealed that strategies focused on developing reciprocity and mitigating mistrust among board members contribute to board members’ perceiving their organizations as effectively achieving their objectives. The study’s findings support positive social change by informing social scientists and members of local nonprofit boards of the perceived gap between services demands and the resources to meet them among board members. Board Member Perceptions of Nonprofit Organization Effectiveness by Laura Levy Maurer MA, New York University, 1973 BS, Cornell University, 1970 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Human Services Walden University August 2014 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, MI 48106 1346 UMI 3637335 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. UMI Number: 3637335 Dedication I dedicate this document to my father, Barnett Levy and to my grandmother, Doris Kirschenbaum Grogan. Acknowledgments I acknowledge the invaluable contribution of my dissertation committee of Walden Faculty, Drs. Pamela Denning, Barbara Benoliel, and Andrew Garland-Forshee. I also gratefully acknowledge the unwavering support of my husband, Gary Maurer.

Social insects work together to complete tasks. However, different individuals within a colony may vary in task proficiency. We investigated if fire ant ( Solenopsis invicta ) worker body size influenced the ability to construct tunnels—a key component of subterranean nests. We monitored excavation by worker groups in a substrate of small wetted glass particles in quasi-two-dimensional arenas. Morphological and network features of the tunnel system were measured. Total tunnel area did not differ significantly between groups of large and small workers, although the tunnel area of control sized workers was significantly larger than that of large workers. Moreover, large workers created wider but shorter tunnels, with slower growth rate of tunnel number. However, edge–vertex scaling and degree distribution of the tunnel network were similar across all treatments. In all cases, the amount of excavated material was correlated with the number of active workers. Our study reveals that morphological features of excavated tunnels show modest variation when constructed by workers of varying sizes, but topological features associated with the tunnel network are conserved. These results suggest that important behavioural aspects of tunnel construction—and thus nest building—are similar among morphologically distinct members of fire ant societies.

The genetic variation present in a species depends on the interplay between mutation, population size, and natural selection. At mutation-(purifying) selection balance (MSB) in a large population, the standing genetic variance for a trait (VG) is predicted to be proportional to the mutational variance for the trait (VM); VM is proportional to the mutation rate for the trait. The ratio VM/VG predicts the average strength of selection (S) against a new mutation. Here we compare VM and VG for lifetime reproductive success (≈ fitness) and body volume in two species of self-fertilizing rhabditid nematodes, Caenorhabditis briggsae and C. elegans, which the evidence suggests have different mutation rates. Averaged over traits, species, and populations within species, the relationship between VG and VM is quite stable, consistent with the hypothesis that differences among groups in standing variance can be explained by differences in mutational input. The average (homozygous) selection coefficient inferred from VM/VG is a few percent, smaller than typical direct estimates from mutation accumulation (MA) experiments. With one exception, the variance present in a worldwide sample of these species is similar to the variance present within a sample from a single locale. These results are consistent with specieswide MSB and uniform purifying selection, but genetic draft (hitchhiking) is a plausible alternative possibility.

Music exerts powerful effects on human performance, behavior, and experience, yet very little is understood about how they are affected by game music. This paper describes a works-in-progress study examining the effects of music and music tempo on game play performance, behavior, and experience in a cognitive game. We found that music influenced mouse activity not directly related to game play, and increased players' feelings of flow.

Midtown Buzz is a partnership between Georgia Tech and Midtown Alliance (MA), focusing on engaging urban communities through mobile innovation. Since 2013, we have been collaborating with the Midtown Atlanta community with the goal of transforming the area into an innovation district. This approach provided us with an opportunity to utilize Midtown as a living laboratory for civic computing research. During the two years of this project we have engaged in a participatory design process with diverse stakeholders to explore the needs of people in the Midtown area, and develop new technologies and approaches to address the identified needs. In this paper we discuss the lessons learned regarding the challenges of bridging the gap between concepts and deployable systems that can create positive transformation in a community.

The Argon project was started to explore the creation of Augmented Reality applications with web technology. We have found this approach to be particularly useful for community-based applications. The Argon web browser has gone through two versions, informed by the work of our students and collaborators on these kinds of applications. In this paper, we highlight a number of the applications we and others have created, what we learned from them, and how our experiences creating these applications informed the design of Argon2 and the requirements for the next version, Argon3.

It is often assumed that the mutation rate is an evolutionarily optimized property of a taxon. The relevant mutation rate is for mutations that affect fitness, U, but the strength of selection on the mutation rate depends on the average effect of a mutation. Determination of U is complicated by the possibility that mutational effects depend on the particular environmental context in which the organism exists. It has been suggested that the effects of deleterious mutations are typically magnified in stressful environments, but most studies confound genotype with environment, so it is unclear to what extent environmental specificity of mutations is specific to a particular starting genotype. We report a study designed to separate effects of species, genotype, and environment on the degradation of fitness resulting from new mutations. Mutations accumulated for >200 generations at 20° in two strains of two species of nematodes that differ in thermal sensitivity. Caenorhabditis briggsae and C. elegans have similar demography at 20°, but C. elegans suffers markedly reduced fitness at 25°. We find little evidence that mutational properties differ depending on environmental conditions and mutational correlations between environments are close to those expected if effects were identical in both environments.

Inter- and intra-regional variations in vertebrae morphology and growth increment counts (band counts) were analyzed for two carcharhinid shark species, Carcharhinus plumbeus (n = 10) and C. limbatus (n = 11). Five sequential vertebrae were removed from the cervical region, above the branchial chamber and posterior to the chondrocrainium, and thoracic region, below the first dorsal fin. Dorsal-ventral height, medial-lateral breadth, and caudal-cranial length were measured for each sampled vertebra. Results indicate no significant difference in vertebral morphology within a sampled region of the vertebral column. However, a significant difference in vertebral morphology was noted between regions for both shark species, with thoracic vertebrae consistently larger than cervical vertebrae. A sub-set of three vertebrae was taken from each sampled region of each shark for sectioning and counting of growth increments. Analyses of growth increment counts by two readers indicated no significant difference in band counts within and between sampled regions.

In this poster, we examine gender differences in older adults playing an off-the-shelf puzzle game (Boom Blox, EA 2008). Game design research for the elderly is an under-developed area, even though one-fifth of adults over the age of sixty-five reported playing video games and those that do so play more often that their younger counterparts. Gender differences in older adult gamers are even less understood. We use quantitative and qualitative techniques to identify gender differences in older adult game players and we discuss ramifications for cognitive game design.

El hospital Garrahan brinda asistencia a pacientes pediatricos con patologias complejas. Las infecciones, incluidas las alimentarias, contribuyen considerablemente en la morbilidad y mortalidad en esta poblacion en riesgo. Con la finalidad de prevenir infecciones alimentarias, el Area de Alimentacion desarrolla un Sistema Preventivo de Analisis de Peligros y Puntos Criticos de Control con enfoque en procesos (HACCP process approach) en la produccion y servicio de alimentos. Objetivo: realizar una exhaustiva revision y evaluacion de los patogenos alimentarios de riesgo segun patologia o practica terapeutica de los pacientes y estandarizar la produccion y servicio de alimentos. Con el criterio "grado de inocuidad al momento del servicio" se estandarizaron las medidas preventivas. La alimentacion fue clasificada en cuatro niveles de proceso. A cada grupo de poblacion asistida, segun riesgo, se le indica uno o mas niveles de alimentacion y se realizan los ajustes individuales necesarios.