78 research outputs found

    Exploring goal-setting, rewards, selfmonitoring, and sharing to motivate physical activity

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    Abstract—Many people have turned to technological tools to help them be physically active. To better understand how goal-setting, rewards, self-monitoring, and sharing can encourage physical activity, we designed a mobile phone application and deployed it in a four-week field study (n=23). Participants found it beneficial to have secondary and primary weekly goals and to receive nonjudgmental reminders. However, participants had problems with some features that are commonly used in practice and suggested in the literature. For example, trophies and ribbons failed to motivate most participants, which raises questions about how such rewards should be designed. A feature to post updates to a subset of their Facebook NewsFeed created some benefits, but barriers remained for most participants. Keywords-Exercise; mobile applications; goal-setting; reminders; rewards; sharing; social networks; persuasive technology I

    altVerto: using intervention and community to promote alternative transportation

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    This paper was submitted to the CHI 2007 Conference as a student design competition project, winning the design competition.We seek to motivate drivers who regularly use web-based local and mapping services and have access to viable alternative transit methods — such as public transportation, carpooling, walking or bicycling — to use these alternatives instead of driving alone. altVerto works with users’ existing habits to intervene during trip planning, and then sustains long-term positive behavior through progress tracking and community-building around alternatives to driving. Our study investigates how computer-mediated intervention at decision making moments and online transit-related community motivates and sustains the use of alternative transit methods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78393/1/altVerto_2007_GukeisenHutchfulKleymeerMunson.pd

    Expression of the Flp proteins by Haemophilus ducreyi is necessary for virulence in human volunteers

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    <p>Abstract</p> <p>Background</p> <p><it>Haemophilus ducreyi</it>, the causative agent of the sexually transmitted disease chancroid, contains a <it>flp </it>(fimbria like protein) operon that encodes proteins predicted to contribute to adherence and pathogenesis. <it>H. ducreyi </it>mutants that lack expression of Flp1 and Flp2 or TadA, which has homology to NTPases of type IV secretion systems, have decreased abilities to attach to and form microcolonies on human foreskin fibroblasts (HFF). A <it>tadA </it>mutant is attenuated in its ability to cause disease in human volunteers and in the temperature dependent rabbit model, but a <it>flp1flp2 </it>mutant is virulent in rabbits. Whether a <it>flp </it>deletion mutant would cause disease in humans is not clear.</p> <p>Results</p> <p>We constructed 35000HPΔ<it>flp1-3</it>, a deletion mutant that lacks expression of all three Flp proteins but has an intact <it>tad </it>secretion system. 35000HPΔ<it>flp1-3 </it>was impaired in its ability to form microcolonies and to attach to HFF in vitro when compared to its parent (35000HP). Complementation of the mutant with <it>flp1-3 </it>in trans restored the parental phenotype. To test whether expression of Flp1-3 was necessary for virulence in humans, ten healthy adult volunteers were experimentally infected with a fixed dose of 35000HP (ranging from 54 to 67 CFU) on one arm and three doses of 35000HPΔ<it>flp1-3 </it>(ranging from 63 to 961 CFU) on the other arm. The overall papule formation rate for the parent was 80% (95% confidence interval, CI, 55.2%-99.9%) and for the mutant was 70.0% (95% CI, 50.5%-89.5%) (<it>P </it>= 0.52). Mutant papules were significantly smaller (mean, 11.2 mm<sup>2</sup>) than were parent papules (21.8 mm<sup>2</sup>) 24 h after inoculation (<it>P </it>= 0.018). The overall pustule formation rates were 46.7% (95% CI 23.7-69.7%) at 30 parent sites and 6.7% (95% CI, 0.1-19.1%) at 30 mutant sites (<it>P </it>= 0.001).</p> <p>Conclusion</p> <p>These data suggest that production and secretion of the Flp proteins contributes to microcolony formation and attachment to HFF cells in vitro. Expression of <it>flp1-3 </it>is also necessary for <it>H. ducreyi </it>to initiate disease and progress to pustule formation in humans. Future studies will focus on how Flp proteins contribute to microcolony formation and attachment in vivo.</p

    Balancing diversity to counter-measure geographical centralization in microblogging platforms

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    We study whether geographical centralization is reflected in the virtual population of microblogging platforms. A consequence of centralization is the decreased visibility and findability of content from less central locations. We propose to counteract geographical centralization in microblogging timelines by promoting geographical diversity through: 1) a characterization of imbalance in location interaction centralization over a graph of geographical interactions from user generated content; 2) geolocation of microposts using imbalance-aware content features in text classifiers, and evaluation of those classifiers according to their diversity and accuracy; 3) definition of a two-step information filtering algorithm to ensure diversity in summary timelines of events. We study our proposal through an analysis of a datase

    Broadening Exposure to Socio-Political Opinions via a Pushy Smart Home Device

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    Motivated by the effects of the filter bubble and echo chamber phenomena on social media, we developed a smart home device, Spkr, that unpredictably “pushes” socio-political discussion topics into the home. The device utilised trending Twitter discussions, categorised by their socio-political alignment, to present people with a purposefully assorted range of viewpoints. We deployed Spkr in 10 homes for 28 days with a diverse range of participants and interviewed them about their experiences. Our results show that Spkr presents a novel means of combating selective exposure to socio-political issues, providing participants with identifiably diverse viewpoints. Moreover, Spkr acted as a conversational prompt for discussion within the home, initiating collective processes and engaging those who would not often be involved in political discussions. We demonstrate how smart home assistants can be used as a catalyst for provocation by altering and pluralising political discussions within households

    A novel approach of homozygous haplotype sharing identifies candidate genes in autism spectrum disorder

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    Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiology. It is primarily characterized by altered cognitive ability including impaired language and communication skills and fundamental deficits in social reciprocity. Despite some notable successes in neuropsychiatric genetics, overall, the high heritability of ASD (~90%) remains poorly explained by common genetic risk variants. However, recent studies suggest that rare genomic variation, in particular copy number variation, may account for a significant proportion of the genetic basis of ASD. We present a large scale analysis to identify candidate genes which may contain low-frequency recessive variation contributing to ASD while taking into account the potential contribution of population differences to the genetic heterogeneity of ASD. Our strategy, homozygous haplotype (HH) mapping, aims to detect homozygous segments of identical haplotype structure that are shared at a higher frequency amongst ASD patients compared to parental controls. The analysis was performed on 1,402 Autism Genome Project trios genotyped for 1 million single nucleotide polymorphisms (SNPs). We identified 25 known and 1,218 novel ASD candidate genes in the discovery analysis including CADM2, ABHD14A, CHRFAM7A, GRIK2, GRM3, EPHA3, FGF10, KCND2, PDZK1, IMMP2L and FOXP2. Furthermore, 10 of the previously reported ASD genes and 300 of the novel candidates identified in the discovery analysis were replicated in an independent sample of 1,182 trios. Our results demonstrate that regions of HH are significantly enriched for previously reported ASD candidate genes and the observed association is independent of gene size (odds ratio 2.10). Our findings highlight the applicability of HH mapping in complex disorders such as ASD and offer an alternative approach to the analysis of genome-wide association data

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
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