On Twitter, Republican Senators are more polarizing than Democrats

While President Donald Trump has become well known for his use of Twitter to criticize Democrats and cajole Republicans, he is not the only politician to use that social media network to chastise their political opponents. In new research, Annelise Russell examines how US Senators use Twitter, finding that, even when they are in the majority, Senate Republicans are more ..

The Rhetorical Agenda: What Twitter Tells Us About Congressional Attention

Understanding how Members of Congress (MCs) distribute their political attention is key to a number of areas of political science research including agenda setting, framing, and issue evolution. Tweets illuminate what lawmakers are paying attention to by aggregating information from newsletters, press releases, and floor debates to provide a birds-eye view of a lawmaker’s diverse agenda. In order to leverage this data efficiently, we trained a supervised machine learning classifier to label tweets according to the Comparative Agenda Project’s Policy Codebook and used the results to examine the differential attention that policy topics receive from MCs. The classifier achieved an F1 score of 0.79 and a Cohen’s kappa with human labelers of 0.78, suggesting good performance. Using this classifier, we labeled 1,485,834 original MC tweets (Retweets were excluded) and conducted a multinomial logistic regression to understand what influenced the policy areas MCs Tweeted about. Our model reveals differences in political attention along party, chamber, and gender lines and their interactions. Our approach allows us to study MCs’ political attention in near real-time and to uncover both intra- and inter-group differences.https://deepblue.lib.umich.edu/bitstream/2027.42/148323/1/Rhetorical Agenda for MPSA 2019.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148323/5/Political Attention under review.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148323/6/Political Attention Supplementary Docs.pdf5056Description of Rhetorical Agenda for MPSA 2019.pdf : Paper presented at MPSA 2019Description of Political Attention under review.pdf : Manuscript submitted for peer reviewDescription of Political Attention Supplementary Docs.pdf : Peer review copy supplementary doc

U.S. senators on Twitter : party polarization in 140 characters

textThe tenor of the Senate no longer relies on traditions of apprenticeship and courtesy. The modern reality is a highly party-polarized institution, encouraging intraparty loyalty and interparty discord. Senators’ behavior on roll-call votes and amendments exhibit this hyper-partisan culture, but that culture extends beyond voting behavior. Members' media activities, including communications with constituents and each other, are equally appealing venues to express excessive partisanship. New media technologies, such as Twitter, are extending this partisan game and punching a ticket for every member of the Senate. Twitter offers a low-cost alternative for members to express malcontent with an opposing party while signaling intra-party party support. In this paper, I tease out the extent to which a member’s party and leadership status affect their likelihood to engage in the partisan discourse that now spans social media. I introduce a unique dataset from the 112th Congress that catalogues six months of senatorial Twitter activity and find that minority party members and party leaders are more likely to name-call and express party loyalty. Twitter may be an alternative agenda space for minority interests that seek to alter the status quo and a public relations platform for party leaders who are tasked with shaping the debate.Governmen

Comblike, Monodisperse Polypeptoid Drag-Tags for DNA Separations by End-Labeled Free-Solution Electrophoresis (ELFSE)

The development of innovative technologies designed to reduce the cost and increase the throughput of DNA separations continues to be important for large-scale sequencing and genotyping efforts. We report research aimed at the further development of a free-solution bioconjugate method of DNA size separation by capillary electrophoresis (CE), in particular, the determination of an optimal molecular architecture for polyamide-based "drag-tags". We synthesized several branched poly(N-methoxyethyl glycine)s (poly(NMEG)s, a class of polypeptoids) as novel friction-generating entities for end-on attachment to DNA molecules. A 30-mer poly(NMEG) "backbone," comprising five evenly spaced reactive -amino groups, was synthesized on solid phase, cleaved, and purified to monodispersity by RP-HPLC. Three different comblike derivatives of this backbone molecule were created by (1) acetylating the -amino groups or (2) appending small, monodisperse NMEG oligomers (a tetramer and an octamer). Grafting of the oligo(NMEG)s was done using solution-phase amide bond formation chemistry. Once purified to total monodispersity, the three different drag-tags were studied by freesolution electrophoresis to observe the effect of branching on their hydrodynamic drag or "R" and hence their ability to separate DNA. Drag was found to scale linearly with total molecular weight, regardless of branch length. The octamer-branched drag-tag-DNA conjugate was used to separate ssDNA products of 50, 75, 100, and 150 bases in length by free-solution CE in less than 10 min. Hence, the use of branched or comblike drag-tags is both a feasible and an effective way to achieve high frictional drag, allowing the high-resolution separation of relatively large DNA molecules by free-solution CE without the need to synthesize very long polymers

Dengue Spatial and Temporal Patterns, French Guiana, 2001

To study a 2001 dengue fever outbreak in Iracoubo, French Guiana, we recorded the location of all patients’ homes and the date when symptoms were first observed. A geographic information system was used to integrate the patient-related information. The Knox test, a classic space-time analysis technique, was used to detect spatiotemporal clustering. Analysis of the relative-risk (RR) variations when space and time distances vary, highlighted the maximum space and time extent of a dengue transmission focus. The results show that heterogeneity in the RR variations in space and time corresponds to known entomologic and epidemiologic factors, such as the mosquito feeding cycle and host-seeking behavior. This finding demonstrates the relevance and potential of the use of GIS and spatial statistics for elaborating a dengue fever surveillance strategy

The politics of prioritization

Political agenda-setting research primarily studies how political institutions direct policy attention and gives little consideration to individual decision-making (Baumgartner and Jones 2009; Kingdon 1995; Baumgartner et al. 2011). This dissertation examines policymakers’ strategic communications to illuminate the important but less understood agenda-setting patterns of individuals. The normalization of social media platforms, like Twitter, gives U.S. senators a new platform to aggregate their policy priorities into a complex agenda that reveals individual decision-making and prioritization. Senators face pressures from constituents, the party, and the institution that lead them to structure unique agenda setting patterns that have implications for both policy and representation. Using a new dataset of all tweets by U.S. senators, I offer new insight into how individual senators divide their limited attention. First, senators must strike a balance between policy and representation because attention to policy results in less time for constituent issues. Second, for political priorities, there is an asymmetric pattern of partisan attention such that Republicans prioritize politics and use partisan rhetoric more often in their political communication. By using a hybrid media measure like Twitter, I glean useful insight into a politician’s agenda to not only understand how politicians rank issues but more broadly the role of policy, politics and representation within a senator’s agenda.Governmen

An experimental series investigating the effects of hyperinsulinemic euglycemia on myocardial blood flow reserve in healthy individuals and on myocardial perfusion defect size following ST-segment elevation myocardial infarction

BackgroundIncomplete restoration of myocardial blood flow (MBF) is reported in up to 30% of ST-segment elevation myocardial infarction (STEMI) despite prompt mechanical revascularization. Experimental hyperinsulinemic euglycemia (HE) increases MBF reserve (MBFR). If fully exploited, this effect may also improve MBF to ischemic myocardium. Using insulin-dextrose infusions to induce HE, we conducted four experiments to determine (1) how insulin infusion duration, dose, and presence of insulin resistance affect MBFR response; and (2) the effect of an insulin-dextrose infusion given immediately following revascularization of STEMI on myocardial perfusion.MethodsThe MBFR was determined using myocardial contrast echocardiography. Experiment 1 (insulin duration): 12 participants received an insulin-dextrose or saline infusion for 120 minutes. MBFR was measured at four time intervals during infusion. Experiment 2 (insulin dose): 22 participants received one of three insulin doses (0.5, 1.5, 3.0 mU/kg/minute) for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 3 (insulin resistance): five metabolic syndrome and six type 2 diabetes (T2DM) participants received 1.5 mU/kg/minute of insulin-dextrose for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 4 (STEMI): following revascularization for STEMI, 20 patients were randomized to receive either 1.5 mU/kg/minute insulin-dextrose infusion for 120 minutes or standard care. Myocardial contrast echocardiography was performed at four time intervals to quantify percentage contrast defect length.ResultsExperiment 1: MBFR increased with time through to 120 minutes in the insulin-dextrose group and did not change in controls. Experiment 2: compared with baseline, MBFR increased in the 1.5 (2.42 ± 0.39 to 3.25 ± 0.77, P = .002), did not change in the 0.5, and decreased in the 3.0 (2.64 ± 0.25 to 2.16 ± 0.33, P = .02) mU/kg/minute groups. Experiment 3: compared with baseline, MBFR increase was only borderline significant in metabolic syndrome and T2DM participants (1.98 ± 0.33 to 2.59 ± 0.45, P = .04, and 1.67 ± 0.35 to 2.14 ± 0.21, P = .05). Experiment 4: baseline percentage contrast defect length was similar in both groups but with insulin decreased with time and was significantly lower than in controls at 60 minutes (2.8 ± 5.7 vs 13.7 ± 10.6, P = .02).ConclusionsPresence of T2DM, insulin infusion duration, and dose are important determinants of the MBFR response to HE. When given immediately following revascularization for STEMI, insulin-dextrose reduces perfusion defect size at one hour. Hyperinsulinemic euglycemia may improve MBF following ischemia, but further studies are needed to clarify this