Cancer Biomarker Discovery: The Entropic Hallmark

Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

Forests and global change: what can genetics contribute to the major forest management and policy challenges of the twenty-first century?

The conservation and sustainable use of forests in the twenty-first century pose huge challenges for forest management and policy. Society demands that forests provide a wide range of ecosystem services, from timber products, raw materials and renewable energy to sociocultural amenities and habitats for nature conservation. Innovative management and policy approaches need to be developed to meet these often-conflicting demands in a context of environmental change of uncertain magnitude and scale. Genetic diversity is a key component of resilience and adaptability. Overall, forest tree populations are genetically very diverse, conferring them an enormous potential for genetic adaptation via the processes of gene flow and natural selection. Here, we review the main challenges facing our forests in the coming century and focus on how recent progress in genetics can contribute to the development of appropriate practical actions that forest managers and policy makers can adopt to promote forest resilience to climate change. Emerging knowledge will inform and clarify current controversies relating to the choice of appropriate genetic resources for planting, the effect of silvicultural systems and stand tending on adaptive potential and the best ways to harness genetic diversity in breeding and conservation programs. Gaps in our knowledge remain, and we identify where additional information is needed (e.g.;the adaptive value of peripheral populations or the genetic determinism of key adaptive traits) and the types of studies that are required to provide this key understanding. © 2015, Springer-Verlag Berlin Heidelberg

Social Conditions and Urban Health Inequities: Realities, Challenges and Opportunities to Transform the Urban Landscape through Research and Action

The process of urbanization entails social improvements with the consequential better quality-of-life for urban residents. However, in many low-income and some middle-income countries, urbanization conveys inequality and exclusion, creating cities and dwellings characterized by poverty, overcrowded conditions, poor housing, severe pollution, and absence of basic services such as water and sanitation. Slums in large cities often have an absence of schools, transportation, health centers, recreational facilities, and other such amenities. Additionally, the persistence of certain conditions, such as poverty, ethnic heterogeneity, and high population turnover, contributes to a lowered ability of individuals and communities to control crime, vandalism, and violence. The social vulnerability in health is not a “natural” or predefined condition but occurs because of the unequal social context that surrounds the daily life of the disadvantaged, and often, socially excluded groups. Social exclusion of individuals and groups is a major threat to development, whether to the community social cohesion and economic prosperity or to the individual self-realization through lack of recognition and acceptance, powerlessness, economic vulnerability, ill health, diminished life experiences, and limited life prospects. In contrast, social inclusion is seen to be vital to the material, psychosocial, and political aspects of empowerment that underpin social well-being and equitable health. Successful experiences of cooperation and networking between slum-based organizations, grassroots groups, local and international NGOs, and city government are important mechanisms that can be replicated in urban settings of different low- and middle-income countries. With increasing urbanization, it is imperative to design health programs for the urban poor that take full advantage of the social resources and resourcefulness of their own communities