David J. Phillips

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We describe the semidefinite analog of the vector packing problem, and show that the semidefinite programming relaxations for Maxcut [10] and graph coloring [16] are in this class of problems. We extend a method of Bienstock and Iyengar [4] which was based on ideas from Nesterov [24] to design an algorithm for computing-approximate solutions for this class(More)
In this paper we define semidefinite packing programs and describe an algorithm to approximately solve these problems. Semidefinite packing programs arise in many applications such as semidefinite programming relaxations for combinatorial optimization problems, sparse principal component analysis, and sparse variance unfolding technique for dimension(More)
As privacy issues have gained social salience, entrepreneurs have begun to offer privacy enhancing technologies (PETs) and the U.S. has begun to enact privacy legislation. But"privacy"is an ambiguous notion. In the liberal tradition, it is an individualistic value protecting citizens from intrusion into a realm of autonomy. A feminist critique suggests that(More)
In this paper we describe an algorithm to approximately solve a class of semidefinite programs called covering semidefinite programs. This class includes many semidefinite programs that arise in the context of developing algorithms for important optimization problems such as Undirected SPARSEST CUT, wireless multicasting, and pattern classification. We give(More)
AIMS Activins A and B, and their binding protein, follistatin, regulate glucose metabolism and inflammation. Consequently, their role in type 2 diabetes (T2D) was examined. METHODS Blood was taken from fasted participants (34 males; 58 females; 50-75 years) with diabetes or during an oral glucose tolerance test (OGTT). Clinical parameters were assessed,(More)
Cystic fibrosis (CF) is the most common life-limiting genetically acquired respiratory disorder. Patients with CF have thick mucus obstructing the airways leading to recurrent infections, bronchiectasis and neutrophilic airway inflammation culminating in deteriorating lung function. Current management targets airway infection and mucus clearance, but(More)
Keloid scars represent a pathological response to cutaneous injury under the regulation of many growth factors. Activin-A, a dimeric protein and a member of the transforming growth factor-beta superfamily, has been shown to regulate various aspects of cell growth and differentiation in the repair of the skin mesenchyme and the epidermis. Thus our aim was to(More)
  • David M. de Kretser, Jonathan G. Bensley, David J. Phillips, Bronwyn J. Levvey, Greg I. Snell, Enjarn Lin +3 others
  • 2016
BACKGROUND Lung transplantation exposes the donated lung to a period of anoxia. Re-establishing the circulation after ischemia stimulates inflammation causing organ damage. Since our published data established that activin A is a key pro-inflammatory cytokine, we assessed the roles of activin A and B, and their binding protein, follistatin, in patients(More)