Online communication among student design teams

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.Cataloged from PDF version of thesis.Includes bibliographical references (pages 79-82).New technological developments are quickly changing the ways the product design community communicates in the workplace and in the classroom. Slack, an online communication software with some project management features, has become a popular communication tool among many workers and students. This thesis examines the Slack conversation conducted by 16 student product development teams in a course at MIT, 2.009: Product Engineering Processes. Following a typical product development process, teams of 17-20 students each used the online communication tool in addition to face-to-face meetings to design new products in one semester. The resulting conversations were analyzed for message count over the course of the semester, message count by day of the week and hour of the day, message count breakdown by user, and communication organization. From these results, it was observed that teams tended to increase their communication right before a deadline and decrease it right after. When viewing teams' communication patterns by day of the week and the hour of the day, it was seen that many teams increased their communication in a short period after team meetings. In both of these graphs, successful teams tended to have more consistent communication. There was a positive correlation (granted, with low a R-squared value) between the amount teams report working on the class and their Slack activity by day. When looking at a team's total amount of communication, it may indicate team members are working well, but it may also indicate they are struggling. Teams with higher levels of success tended to have a more organized communication structure than teams with lower levels of success, as assessed by instructors. In addition to the data collected in this thesis, further research is still needed to understand with more certainty how online communication patterns correlate to teams' levels of success or team behaviors.by Georgia D. Van de Zande.S.M

Urbanization

Antiquity (Religious Texts and Tradition in Antiquity

DNA methylation plays a crucial role during early <i>Nasonia</i> development

Although the role of DNA methylation in insect development is still poorly understood, the number and role of DNA methyltransferases in insects vary strongly between species. DNA methylation appears to be widely present among the social hymenoptera and functional studies in Apis have suggested a crucial role for de novo methylation in a wide variety of developmental processes. The sequencing of three parasitoid Nasonia genomes revealed the presence of three Dnmt1 (Dnmt1a, Dnmt1b and Dnmt1c) genes and one Dnmt2 and Dnmt3 gene, suggesting a role of DNA methylation in Nasonia development. In the present study we show that in Nasonia vitripennis all Dnmt1 messenger RNAs (mRNAs) and Dnmt3 mRNA are maternally provided to the embryo and, of these, Dnmt1a is essential during early embryogenesis. Lowering of maternal Dnmt1a mRNA results in embryonic lethality during the onset of gastrulation. This dependence on maternal Dnmt1a during embryogenesis in an organismal group outside the vertebrates, suggests evolutionary conservation of the function of Dnmt1 during embryogenesis.</p

The AGE reader:a non-invasive method to assess long term tissue damage

AIMS: Advanced glycation endproducts (AGEs) are sugar modified adducts which arise during non-enzymatic glycoxidative stress. These compounds may become systemically elevated in disease states, and accumulate in tissue, especially on long-lived proteins. AGEs have been implicated in various acute, and chronic diseases, stressing the need for reliable and comprehensive measuring techniques. Measurement of AGEs in tissue such as skin requires skin biopsies, which is an invasive procedure. The AGE Reader has been developed to assess skin autofluorescence (SAF) non-invasively by the fluorescent properties of several AGEs. RESULTS/CONCLUSION: Various studies have shown that SAF is a useful marker of disease processes associated with oxidative stress. It is prospectively associated with development of cardiovascular events in patients with diabetes, renal or cardiovascular disease, and it predicts diabetes, cardiovascular disease and mortality in the general population. However, when measuring SAF in individual subjects, several factors may limit the reliability of the measurement, and hamper its use as a systemic biomarker for AGEs. These include endogenous factors present in the skin that absorb emission light such as melanin in dark-skinned subjects, but also factors that lead to temporal changes in SAF such as acute diseases and strenuous physical exercise associated with glycoxidative stress. Also, exogenous factors could potentially influence SAF levels inadvertently such as nutrition, and for example the application of skin care products. This review will give an overview of the AGE Reader functionality and the intrinsic, and exogenous factors which potentially influence the SAF assessment in individual subjects

Recombination and its impact on the genome of the haplodiploid parasitoid wasp Nasonia

Homologous meiotic recombination occurs in most sexually reproducing organisms, yet its evolutionary advantages are elusive. Previous research explored recombination in the honeybee, a eusocial hymenopteran with an exceptionally high genome-wide recombination rate. A comparable study in a non-social member of the Hymenoptera that would disentangle the impact of sociality from Hymenoptera-specific features such as haplodiploidy on the evolution of the high genome-wide recombination rate in social Hymenoptera is missing. Utilizing single-nucleotide polymorphisms (SNPs) between two Nasonia parasitoid wasp genomes, we developed a SNP genotyping microarray to infer a high-density linkage map for Nasonia. The map comprises 1,255 markers with an average distance of 0.3 cM. The mapped markers enabled us to arrange 265 scaffolds of the Nasonia genome assembly 1.0 on the linkage map, representing 63.6% of the assembled N. vitripennis genome. We estimated a genome-wide recombination rate of 1.4-1.5 cM/Mb for Nasonia, which is less than one tenth of the rate reported for the honeybee. The local recombination rate in Nasonia is positively correlated with the distance to the center of the linkage groups, GC content, and the proportion of simple repeats. In contrast to the honeybee genome, gene density in the parasitoid wasp genome is positively associated with the recombination rate; regions of low recombination are characterized by fewer genes with larger introns and by a greater distance between genes. Finally, we found that genes in regions of the genome with a low recombination frequency tend to have a higher ratio of non-synonymous to synonymous substitutions, likely due to the accumulation of slightly deleterious non-synonymous substitutions. These findings are consistent with the hypothesis that recombination reduces interference between linked sites and thereby facilitates adaptive evolution and the purging of deleterious mutations. Our results imply that the genomes of haplodiploid and of diploid higher eukaryotes do not differ systematically in their recombination rates and associated parameters.Publisher PDFPeer reviewe

Demographics, presentation and clinical outcomes after traumatic bifrontal contusions: a systematic review

Traumatic bifrontal contusions (TBC) form a recognised clinical entity among patients with traumatic brain injury (TBI). This study aims to systematically review current literature on demographics, management, and predictors of outcomes of patients with TBC. A multi-database literature search (PubMed, Cochrane, OVID Medline/Embase) was performed using PRISMA as a search strategy. Studies were selected by predefined selection criteria (PROSPERO: CRD42018055390), and risk of bias was assessed using an adapted form of ROBINS-I tool. Of the 275 studies yielded by the literature search, seven articles met the criteria for inclusion, all of which were level III evidence. Total cohort consisted of 468 patients; predominantly male (n = 5; 303/417 patients) with average age 44.3 years (range, 7–81). Falls (44.9%) and road traffic accidents (46.6%) were the commonest mechanisms of injury with an average presentation GCS of 9.2 (n = 3, 119 patients). GCS on admission of ≤ 13.1 and contusion volume at day 2 post-injury of ≥ 62.9cm3 were associated with increased risk of deterioration needing surgical interventions (n = 1, 7 patients). The majority of patients underwent surgery; the average GOS was 4, at an average follow-up duration of 11.7 months (n = 6, 356 patients). The currently available evidence on the management of TBC is scarce. Larger multicentre well-designed studies are needed to further delineate the factors behind acute deterioration, the effectiveness of management options. Once in place, this can be used to develop and test an algorithmic approach to management of TBC resulting in consistently improved outcomes