Tweeting Supertyphoon Haiyan: Evolving Functions of Twitter during and after a Disaster Event

When disaster events capture global attention users of Twitter form transient interest communities that disseminate information and other messages online. This paper examines content related to Typhoon Haiyan (locally known as Yolanda) as it hit the Philippines and triggered international humanitarian response and media attention. It reveals how Twitter conversations about disasters evolve over time, showing an issue attention cycle on a social media platform. The paper examines different functions of Twitter and the information hubs that drive and sustain conversation about the event. Content analysis shows that the majority of tweets contain information about the typhoon or its damage, and disaster relief activities. There are differences in types of content between the most retweeted messages and posts that are original tweets. Original tweets are more likely to come from ordinary users, who are more likely to tweet emotions, messages of support, and political content compared with official sources and key information hubs that include news organizations, aid organization, and celebrities. Original tweets reveal use of the site beyond information to relief coordination and response.     

Gene family evolution: an in-depth theoretical and simulation analysis of non-linear birth-death-innovation models

Background  

The size distribution of gene families in a broad range of genomes is well approximated by a generalized Pareto function. Evolution of ensembles of gene families can be described with Birth, Death, and Innovation Models (BDIMs). Analysis of the properties of different versions of BDIMs has the potential of revealing important features of genome evolution.     

Abstracts of the fourth joint german-italian purine club meeting 2011

Abstract

Abstracts of the Fourth Joint German-Italian Purine Club Meeting 2011     

Report of the 2011 annual meeting of the Italian Society for Virology

The 10th annual meeting of the Italian Society for Virology (SIV) comprised seven plenary sessions focused on: General virology and viral genetics; Virus-Host interaction and pathogenesis; Viral oncology; Emerging viruses and zoonotic, foodborne and environmental pathways of transmission; Viral immunology and vaccines; Medical virology and antiviral therapy; Viral biotechnologies and gene therapy. The meeting had an attendance of 143 virologists, about 60% were senior, and the other were young scientists. The submitted abstracts amounted to 88 and the abstracts selected for oral presentation were 41. Complete abstracts of oral and poster presentations are available at the web site www.siv-virologia.it. A summary of the plenary lectures and oral selected presentations is reported.     

The EEG, spike activity and the brain processor: an attempt at paradigm analysis]

A notion is introduced about the brain processor as a natural mechanism of brain activity, which is close to the neurocomputer technology. In contrast to the common computer metaphor, this notion can be used as a real basis for explanation of many brain phenomena.     

ATR signalling: more than meeting at the fork

Preservation of genome integrity via the DNA-damage response is critical to prevent disease. ATR (ataxia telangiectasia mutated- and Rad3-related) is essential for life and functions as a master regulator of the DNA-damage response, especially during DNA replication. ATR controls and co-ordinates DNA replication origin firing, replication fork stability, cell cycle checkpoints and DNA repair. Since its identification 15 years ago, a model of ATR activation and signalling has emerged that involves localization to sites of DNA damage and activation through protein-protein interactions. Recent research has added an increasingly detailed understanding of the canonical ATR pathway, and an appreciation that the canonical model does not fully capture the complexity of ATR regulation. In the present article, we review the ATR signalling process, focusing on mechanistic findings garnered from the identification of new ATR-interacting proteins and substrates. We discuss how to incorporate these new insights into a model of ATR regulation and point out the significant gaps in our understanding of this essential genome-maintenance pathway.     

Decreased NK activity in hairy cell leukemia (HCL): an analysis at the cellular level

Peripheral blood lymphocytes (PBL) of eleven patients with Hairy Cell Leukemia were studied for surface phenotype and for NK activity against the K 562 cell line (using both the standard 51Cr Release Assay and the Single Cell Cytotoxicity Assay on poly-L-lysine coated coverslips). A significant reduction in NK activity, target binding cells (TBC) and NK active cells (NKa) was detected. In some cases however, despite a very low percentage of NKa, residual NK activity was observed, suggesting an efficient recycling capacity.     

Quantitative in-depth analysis of the dynamic secretome of activated Jurkat T-cells

Proteins secreted by cells are of the highest biomedical relevance since they play a significant role in the progression of numerous diseases. However, characterization of the proteins specifically secreted in response to precise stimuli is challenging, since these proteins are contaminated by cellular byproducts. Here we present a method to characterize a dynamic secretome and demonstrate its utility by performing the deepest quantitative analysis to date of proteins secreted by lymphoid Jurkat T-cells upon activation. Cell-free supernatant proteins were analyzed by using an optimized protocol for differential (18)O/(16)O-labeling and LC-MS/MS, followed by statistical analysis using a random-effects model. More than 4000 unique peptides belonging to 1288 proteins were identified and a large proportion could be quantified. To determine the proteins whose secretion was up-regulated upon T-cell activation, protein variance of the null hypothesis was estimated after protein classification in terms of secretion and ontology using bioinformatic tools. 62 proteins showed a statistically significant change in abundance upon cell activation and most of them (49 proteins) were up-regulated. These proteins were functionally involved mainly in inflammatory response, signal transduction, cell growth and differentiation and cell redox homeostasis. Our approach provides a promising technology for the high-throughput quantitative study of dynamic secretomes.     

Abstracts of papers read at the winter meeting at the University of Bristol

Summaries of changes since 1965 in the phytoplankton fora of Lake Mälren, the third largest lake in Sweden, are presented. The phosphorus load was reduced by 90% in 1970–1973 and a fertilizer factory on the lake decreased its N-outlet by 80%. The phosphorus concentrations in the water decreased by up to 40% and the total nitrogen concentration by 50% between 1970 and 1983. But in one part of the lake the N-concentration increased by 50% due to drainage from surrounding land and atmospheric deposition. With changes in the ratios of N/P and Si/P as well as the turbidity of the water there have been drastic alterations in species composition and total phytoplankton biomasses.

There was a rise in the number of species over the period of study at all times of the year. Colonial species decreased while small and large flagellates of chrysophytes, cryptomonads and dinoflagellates increased. In the most polluted basins cyanobacterial blooms have halved their peak biomasses or have almost disappeared.

At times during the 19 years of the study the summer phytoplankton communities have been tested to fits of a log-normal distribution, assuming such a distribution to be valid in well-balanced ecosystems. The general trend indicates an increasing adjustment to a log-normal distribution. Phytoplankton changes in the lake are associated with effects known to cause reversed eutrophication, although climatically induced variations may also be identified.