Social media and protest mobilization: evidence from the Tunisian revolution

This article explores how social media acted as a catalyst for protest mobilization during the Tunisian revolution in late 2010 and early 2011. Using evidence from protests we argue that social media acted as an important resource for popular mobilization against the Ben Ali regime. Drawing on insights from “resource mobilization theory”, we show that social media (1) allowed a “digital elite” to break the national media blackout through brokering information for mainstream media; (2) provided a basis for intergroup collaboration for a large “cycle of protest”; (3) reported event magnitudes that raised the perception of success for potential free riders, and (4) provided additional “emotional mobilization” through depicting the worst atrocities associated with the regime’s response to the protests. These findings are based on background talks with Tunisian bloggers and digital activists and a revealed preference survey conducted among a sample of Tunisian internet users (February–May 2012)

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Ceramic Spheres—A Novel Solution to Deep Sea Buoyancy Modules

Ceramic-based hollow spheres are considered a great driving force for many applications such as offshore buoyancy modules due to their large diameter to wall thickness ratio and uniform wall thickness geometric features. We have developed such thin-walled hollow spheres made of alumina using slip casting and sintering processes. A diameter as large as 50 mm with a wall thickness of 0.5–1.0 mm has been successfully achieved in these spheres. Their material and structural properties were examined by a series of characterization tools. Particularly, the feasibility of these spheres was investigated with respect to its application for deep sea (>3000 m) buoyancy modules. These spheres, sintered at 1600 °C and with 1.0 mm of wall thickness, have achieved buoyancy of more than 54%. As the sphere’s wall thickness was reduced (e.g., 0.5 mm), their buoyancy reached 72%. The mechanical performance of such spheres has shown a hydrostatic failure pressure above 150 MPa, corresponding to a rating depth below sea level of 5000 m considering a safety factor of 3. The developed alumina-based ceramic spheres are feasible for low cost and scaled-up production and show great potential at depths greater than those achievable by the current deep-sea buoyancy module technologies

Pemetrexed/oxaliplatin for first-line treatment of patients with advanced colorectal cancer: a phase II trial of the National Surgical Adjuvant Breast and Bowel Project Foundation Research Program.

BACKGROUND: Pemetrexed and oxaliplatin have clinical activity as single agents in colorectal cancer (response rates, 10%-17%). In this study, these drugs were used in combination as first-line therapy in a group of patients with metastatic colorectal cancer. PATIENTS AND METHODS: Fifty-four evaluable patients were to receive pemetrexed (500 mg/m2) with folic acid and vitamin B12 supplementation and oxaliplatin (120 mg/m2) every 21 days for 6 cycles or until disease progression occurred. Patients with stable or responding disease could continue therapy beyond 6 cycles at the discretion of the investigator. Eligibility criteria included a diagnosis of untreated metastatic adenocarcinoma of the colon or rectum, measurable disease, Zubrod performance status or=12 weeks life expectancy. RESULTS: The confirmed clinical response rate (primary endpoint) was 29.6% (95% confidence interval [CI], 18%-48.6%), with 1 complete response and 15 partial responses. Median time to progression was 5.3 months (95% CI, 3.9-6.3 months), and median survival was 12.3 months (95% CI, 8.6-17 months). Grade 3/4 nadir neutropenia occurred in 33.3% of patients, and 3 patients experienced grade 3 febrile neutropenia or infection associated with grade 3/4 neutropenia. Grade 3/4 nadir thrombocytopenia was seen in 11.1% of patients. Only 4% of the patients developed grade 3/4 neurotoxicity. CONCLUSION: This regimen of pemetrexed and oxaliplatin has activity in advanced colorectal cancer, and the toxicity profile suggests that escalation of the dose of pemetrexed in this combination may be possible