From Preparedness to Recovery: A Tri-Level Programming Model for Disaster Relief Planning

This paper proposes a tri-level programming model for disaster preparedness planning. The top level addresses facility location and inventory pre-positioning decisions; the second level represents damage caused by the disaster, while the third level determines response and recovery decisions. We use an interdiction framework instead of a stochastic or chance-constrained model. This allows the extent of damage to be treated as a parameter to facilitate scenario exploration for decision-support. We develop an iterative dual-ascent solution approach. Computational results show that our approach is efficient, and we can also draw some insights on disaster relief planning. © 2013 Springer-Verlag.Link_to_subscribed_fulltex

Decision Support in Supply Chain Management for Disaster Relief in Somalia

Somalia, a country situated in Eastern Africa has been struggling between rival warlords and an inability to deal with famine. Diseases have resulted to the deaths of up to millions of people. According to a New York Times article on 25 November 2011, Somalia has become a suffering and failed state. The inadequate infrastructure and poorly planned logistics of Somalia may lead to the destruction of the country. To address these concerns, it is necessary that humanitarian aid is prepositioned to provide victims with sufficient relief. This chapter addresses some of the issues in supply chain management with the trade-off between stockpile cost and shortage cost by using pre-emptive multi-objective programming. The proposed criteria of the model are described. This is followed by a case study based on Somalia, illustrating the functionality of the model.National Research Foundation and the University of Pretoria.http://www.springer.com/series/11156hb201

Social insect genomes exhibit dramatic evolution in gene composition and regulation while preserving regulatory features linked to sociality.

Genomes of eusocial insects code for dramatic examples of phenotypic plasticity and social organization. We compared the genomes of seven ants, the honeybee, and various solitary insects to examine whether eusocial lineages share distinct features of genomic organization. Each ant lineage contains ∼4000 novel genes, but only 64 of these genes are conserved among all seven ants. Many gene families have been expanded in ants, notably those involved in chemical communication (e.g., desaturases and odorant receptors). Alignment of the ant genomes revealed reduced purifying selection compared with Drosophila without significantly reduced synteny. Correspondingly, ant genomes exhibit dramatic divergence of noncoding regulatory elements; however, extant conserved regions are enriched for novel noncoding RNAs and transcription factor-binding sites. Comparison of orthologous gene promoters between eusocial and solitary species revealed significant regulatory evolution in both cis (e.g., Creb) and trans (e.g., fork head) for nearly 2000 genes, many of which exhibit phenotypic plasticity. Our results emphasize that genomic changes can occur remarkably fast in ants, because two recently diverged leaf-cutter ant species exhibit faster accumulation of species-specific genes and greater divergence in regulatory elements compared with other ants or Drosophila. Thus, while the "socio-genomes" of ants and the honeybee are broadly characterized by a pervasive pattern of divergence in gene composition and regulation, they preserve lineage-specific regulatory features linked to eusociality. We propose that changes in gene regulation played a key role in the origins of insect eusociality, whereas changes in gene composition were more relevant for lineage-specific eusocial adaptations