Investigating the Mechanism of Cell Competition in mESCs

Cell competition is a type of cell-cell interaction first described in Drosophila by Morato and Ripoll (1976), whereupon the co-existence of two cell populations with different metabolic properties or growth rates results in the growth of the stronger population at the expensive of the weaker one. BMP2 and 4 are the Drosophila homologues of Decapentaplegic which has been shown to have roles in cell competition. Based on data from studies on Drosophila models of cell competition, the lab generated mESCs null for Bmpr1a and investigated their behaviour when co-cultured with wild-type mESCs as a mammalian model of cell competition. This report further investigates changes in proliferation and apoptosis among competing cells and begins to investigate the signalling pathways which drive loser cells to initiate apoptosis. We report that apoptosis is caspase-dependent and possibly mediated by ERK and Wnt signalling as modulating these pathways changes the dynamics of competing cells. The report utilises a transwell growth system to demonstrate that cell competition is mediated by unknown signalling factors, an observation which has also been described in models of competing cells in Drosophila. The report shows that differentiation of mESCs is an important inducing factor for cell competition as naïve mESCs do not compete. Lastly this study shows that cell competition is a general mechanism of maintaining stem cell quality as other mutations which incur a growth or metabolic disadvantage as mESCs with defects in autophagy or are tetraploid are also eliminated by cell competition when co-cultured with wild-type cells.Open Acces

Mapping Digital Media: Kenya

The Mapping Digital Media project examines the global opportunities and risks created by the transition from traditional to digital media. Covering 60 countries, the project examines how these changes affect the core democratic service that any media system should provide: news about political, economic, and social affairs.The new constitution of Kenya, promulgated in August 2010, is considered a major positive development in ensuring the free flow of information. It provides for freedom of media as a right and fundamental freedom. Section 34 guarantees the independence of electronic, print, and all other types of media. The government has also pledged to enhance Kenya's technological infrastructure by investing in the roll-out of fiber optic cable throughout the country and working on "digital villages" to enable people in remote parts of the country to access broadband internet. Stiff competition in the mobile phone market has also lowered access costs and there is a significant increase in news diversity as a direct result of the convergence of internet, television, and radio on mobile platforms.In online journalism, the virtues associated with ethics—accuracy, honesty, truth, impartiality, fairness, balance, respect for autonomy of ordinary people—are barely respected, largely because there is no effective way of policing this, and there are no legal penalties. Concentration of ownership has increased in the last five years and transparency in ownership of media has improved only slightly over the past five years. The government controls media licensing—a process that is shrouded in secrecy, so that it is difficult to establish who owns which media house.The overall framework of policy and law is not yet adequate for digitized media in Kenya. The national ICT policy of 2006 committed the government to support and encourage pluralism and diversity. While this led to a proliferation of channels, it did not do much for content diversity due to the level of concentration of media. A lack of resources to build the digital infrastructure, consumer ignorance of what the switch means and whether the public can afford the end-user devices are some of the challenges faced in Kenya's digital switchove

Land Grant Application- Fulmer, George (Bangor)

Land grant application submitted to the Maine Land Office on behalf of George Fulmer for service in the Revolutionary War, by their widow Nancy.https://digitalmaine.com/revolutionary_war_me_land_office/1357/thumbnail.jp

Retrospective Evaluation of Clinical Experience With Intravenous Ascorbic Acid in Patients With Cancer.

BACKGROUND: Intravenous ascorbic acid (IV AA) has been used extensively in cancer patients throughout the United States. Currently, there are limited data on the safety and clinical effects of IV AA. The purpose of this study was to expand the current literature using a retrospective analysis of adverse events and symptomatic changes of IV AA in a large sample of cancer patients. METHODS: We conducted a retrospective chart review of all patients receiving IV AA for cancer at the Thomas Jefferson University Hospital over a 7-year period. We assessed all reports of adverse events, laboratory findings, and hospital or emergency department admissions. We also reviewed quality-of-life data, including fatigue, nausea, pain, appetite, and mood. RESULTS: There were 86 patients who received a total of 3034 doses of IV AA ranging from 50 to 150g. In all, 32 patients received only ascorbic acid as part of their cancer management (1197 doses), whereas 54 patients received ascorbic acid in conjunction with chemotherapy (1837 doses). The most common adverse events related to ascorbic acid were temporary nausea and discomfort at the injection site. All events reported in the ascorbic acid alone group were associated with less than 3% of the total number of infusions. Patients, overall, reported improvements in fatigue, pain, and mood while receiving ascorbic acid. CONCLUSIONS: The results of this retrospective analysis support the growing evidence that IV AA is generally safe and well tolerated in patients with cancer, and may be useful in symptom management and improving quality of life