146 research outputs found

    How Could an Intranet be Like a Friend to Me?: Why Standardized UX Scales Don't Always Fit

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    "I hope that this survey is a joke because it made me laugh so much". This quote is just one example of many negative respondents' reactions gathered during a large-scale user experience (UX) study. Unfortunately, the survey was no joke, rather a well-constructed and validated standardized UX scale. This paper critically reflects on the use and relevance of standardized UX scales for the evaluation of UX in business contexts. We report on a real-world use case where the meCUE questionnaire has been used to assess employees' experience (N=263) with their organization's intranet. Strong users' reactions to the survey's items and statistical analyses both suggest that the scale is unsuitable for the evaluation of business-oriented systems. Drawing on the description of this inadequacy, we discuss the quality of academic UX tools, calling into question the relevance for practice of academic methods

    Genome Evolution of a Tertiary Dinoflagellate Plastid

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    The dinoflagellates have repeatedly replaced their ancestral peridinin-plastid by plastids derived from a variety of algal lineages ranging from green algae to diatoms. Here, we have characterized the genome of a dinoflagellate plastid of tertiary origin in order to understand the evolutionary processes that have shaped the organelle since it was acquired as a symbiont cell. To address this, the genome of the haptophyte-derived plastid in Karlodinium veneficum was analyzed by Sanger sequencing of library clones and 454 pyrosequencing of plastid enriched DNA fractions. The sequences were assembled into a single contig of 143 kb, encoding 70 proteins, 3 rRNAs and a nearly full set of tRNAs. Comparative genomics revealed massive rearrangements and gene losses compared to the haptophyte plastid; only a small fraction of the gene clusters usually found in haptophytes as well as other types of plastids are present in K. veneficum. Despite the reduced number of genes, the K. veneficum plastid genome has retained a large size due to expanded intergenic regions. Some of the plastid genes are highly diverged and may be pseudogenes or subject to RNA editing. Gene losses and rearrangements are also features of the genomes of the peridinin-containing plastids, apicomplexa and Chromera, suggesting that the evolutionary processes that once shaped these plastids have occurred at multiple independent occasions over the history of the Alveolata

    Genome Fragmentation Is Not Confined to the Peridinin Plastid in Dinoflagellates

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    When plastids are transferred between eukaryote lineages through series of endosymbiosis, their environment changes dramatically. Comparison of dinoflagellate plastids that originated from different algal groups has revealed convergent evolution, suggesting that the host environment mainly influences the evolution of the newly acquired organelle. Recently the genome from the anomalously pigmented dinoflagellate Karlodinium veneficum plastid was uncovered as a conventional chromosome. To determine if this haptophyte-derived plastid contains additional chromosomal fragments that resemble the mini-circles of the peridin-containing plastids, we have investigated its genome by in-depth sequencing using 454 pyrosequencing technology, PCR and clone library analysis. Sequence analyses show several genes with significantly higher copy numbers than present in the chromosome. These genes are most likely extrachromosomal fragments, and the ones with highest copy numbers include genes encoding the chaperone DnaK(Hsp70), the rubisco large subunit (rbcL), and two tRNAs (trnE and trnM). In addition, some photosystem genes such as psaB, psaA, psbB and psbD are overrepresented. Most of the dnaK and rbcL sequences are found as shortened or fragmented gene sequences, typically missing the 3′-terminal portion. Both dnaK and rbcL are associated with a common sequence element consisting of about 120 bp of highly conserved AT-rich sequence followed by a trnE gene, possibly serving as a control region. Decatenation assays and Southern blot analysis indicate that the extrachromosomal plastid sequences do not have the same organization or lengths as the minicircles of the peridinin dinoflagellates. The fragmentation of the haptophyte-derived plastid genome K. veneficum suggests that it is likely a sign of a host-driven process shaping the plastid genomes of dinoflagellates

    Pioglitazone administration alters ovarian gene expression in aging obese lethal yellow mice

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    <p>Abstract</p> <p>Background</p> <p>Women with polycystic ovary syndrome (PCOS) are often treated with insulin-sensitizing agents, e.g. thiazolidinediones (TZD), which have been shown to reduce androgen levels and improved ovulatory function. Acting via peroxisome proliferator-activated receptor (PPAR) gamma, TZD alter the expression of a large variety of genes. Lethal yellow (LY; C57BL/6J Ay/a) mice, possessing a mutation (Ay) in the agouti gene locus, exhibit progressive obesity, reproductive dysfunction, and altered metabolic regulation similar to women with PCOS. The current study was designed to test the hypothesis that prolonged treatment of aging LY mice with the TZD, pioglitazone, alters the ovarian expression of genes that may impact reproduction.</p> <p>Methods</p> <p>Female LY mice received daily oral doses of either 0.01 mg pioglitazone (n = 4) or an equal volume of vehicle (DMSO; n = 4) for 8 weeks. At the end of treatment, ovaries were removed and DNA microarrays were used to analyze differential gene expression.</p> <p>Results</p> <p>Twenty-seven genes showed at least a two-fold difference in ovarian expression with pioglitazone treatment. These included leptin, angiopoietin, angiopoietin-like 4, Foxa3, PGE1 receptor, resistin-like molecule-alpha (RELM), and actin-related protein 6 homolog (ARP6). For most altered genes, pioglitazone changed levels of expression to those seen in untreated C57BL/6J(a/a) non-mutant lean mice.</p> <p>Conclusion</p> <p>TZD administration may influence ovarian function via numerous diverse mechanisms that may or may not be directly related to insulin/IGF signaling.</p

    Patient complexity in quality comparisons for glycemic control: An observational study

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    <p>Abstract</p> <p>Background</p> <p>Patient complexity is not incorporated into quality of care comparisons for glycemic control. We developed a method to adjust hemoglobin A1c levels for patient characteristics that reflect complexity, and examined the effect of using adjusted A1c values on quality comparisons.</p> <p>Methods</p> <p>This cross-sectional observational study used 1999 national VA (US Department of Veterans Affairs) pharmacy, inpatient and outpatient utilization, and laboratory data on diabetic veterans. We adjusted individual A1c levels for available domains of complexity: age, social support (marital status), comorbid illnesses, and severity of disease (insulin use). We used adjusted A1c values to generate VA medical center level performance measures, and compared medical center ranks using adjusted versus unadjusted A1c levels across several thresholds of A1c (8.0%, 8.5%, 9.0%, and 9.5%).</p> <p>Results</p> <p>The adjustment model had R<sup>2 </sup>= 8.3% with stable parameter estimates on thirty random 50% resamples. Adjustment for patient complexity resulted in the greatest rank differences in the best and worst performing deciles, with similar patterns across all tested thresholds.</p> <p>Conclusion</p> <p>Adjustment for complexity resulted in large differences in identified best and worst performers at all tested thresholds. Current performance measures of glycemic control may not be reliably identifying quality problems, and tying reimbursements to such measures may compromise the care of complex patients.</p

    Defining Haptic Experience: Foundations for Understanding, Communicating, and Evaluating HX

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    Haptic technology is maturing, with expectations and evidence that it will contribute to user experience (UX). However, we have very little understanding about how haptic technology can influence people’s experience. Researchers and designers need a way to understand, communicate, and evaluate haptic technology’s effect on UX. From a literature review and two studies – one with haptics novices, the other with expert hapticians – we developed a theoretical model of the factors that constitute a good haptic experience (HX). We define HX and propose its constituent factors: design parameters of Timeliness, Density, Intensity, and Timbre; the cross-cutting concern of Personalization; usability requirements of Utility, Causality, Consistency, and Saliency; and experiential factors of Harmony, Expressivity, Autotelics, Immersion, and Realism as guiding constructs important for haptic experience. This model will help guide design and research of haptic systems, inform language around haptics, and provide the basis for evaluative instruments, such as checklists, heuristics, or questionnaires.We acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), [funding reference number 2019-06589

    Multigene Phylogeny of Choanozoa and the Origin of Animals

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    Animals are evolutionarily related to fungi and to the predominantly unicellular protozoan phylum Choanozoa, together known as opisthokonts. To establish the sequence of events when animals evolved from unicellular ancestors, and understand those key evolutionary transitions, we need to establish which choanozoans are most closely related to animals and also the evolutionary position of each choanozoan group within the opisthokont phylogenetic tree. Here we focus on Ministeria vibrans, a minute bacteria-eating cell with slender radiating tentacles. Single-gene trees suggested that it is either the closest unicellular relative of animals or else sister to choanoflagellates, traditionally considered likely animal ancestors. Sequencing thousands of Ministeria protein genes now reveals about 14 with domains of key significance for animal cell biology, including several previously unknown from deeply diverging Choanozoa, e.g. domains involved in hedgehog, Notch and tyrosine kinase signaling or cell adhesion (cadherin). Phylogenetic trees using 78 proteins show that Ministeria is not sister to animals or choanoflagellates (themselves sisters to animals), but to Capsaspora, another protozoan with thread-like (filose) tentacles. The Ministeria/Capsaspora clade (new class Filasterea) is sister to animals and choanoflagellates, these three groups forming a novel clade (filozoa) whose ancestor presumably evolved filose tentacles well before they aggregated as a periciliary collar in the choanoflagellate/sponge common ancestor. Our trees show ichthyosporean choanozoans as sisters to filozoa; a fusion between ubiquitin and ribosomal small subunit S30 protein genes unifies all holozoa (filozoa plus Ichthyosporea), being absent in earlier branching eukaryotes. Thus, several successive evolutionary innovations occurred among their unicellular closest relatives prior to the origin of the multicellular body-plan of animals

    Elevated Non-Esterified Fatty Acid Concentrations during Bovine Oocyte Maturation Compromise Early Embryo Physiology

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    Elevated concentrations of serum non-esterified fatty acids (NEFA), associated with maternal disorders such as obesity and type II diabetes, alter the ovarian follicular micro-environment and have been associated with subfertility arising from reduced oocyte developmental competence. We have asked whether elevated NEFA concentrations during oocyte maturation affect the development and physiology of zygotes formed from such oocytes, using the cow as a model. The zygotes were grown to blastocysts, which were evaluated for their quality in terms of cell number, apoptosis, expression of key genes, amino acid turnover and oxidative metabolism. Oocyte maturation under elevated NEFA concentrations resulted in blastocysts with significantly lower cell number, increased apoptotic cell ratio and altered mRNA abundance of DNMT3A, IGF2R and SLC2A1. In addition, the blastocysts displayed reduced oxygen, pyruvate and glucose consumption, up-regulated lactate consumption and higher amino acid metabolism. These data indicate that exposure of maturing oocytes to elevated NEFA concentrations has a negative impact on fertility not only through a reduction in oocyte developmental capacity but through compromised early embryo quality, viability and metabolism
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