Multiuser detection with an unknown number of active users: receiver design

In multiuser detection, the set of users active at any time may be unknown to the receiver. In these conditions, optimum reception consists of detecting simultaneously the set of activeusers and their data, problem that can be solved exactly by applying random-set theory (RST) and Bayesian recursions (BR). However, implementation of optimum receivers may be limited by their complexity, which grows exponentially with the number of potential users. In this paper we examine three strategies leading to reduced-complexity receivers.In particular, we show how a simple approximation of BRs enables the use of Sphere Detection (SD) algorithm, whichexhibits satisfactory performance with limited complexity.

Immigration controls and the erosion of popular sovereignty

The idea that immigration controls in Western developed states are a response to popular pressure is axiomatic in the academic literature on migration. In the academic literature and in policy circles it is also commonplace to hear that migration is eroding the sovereignty of states. This article challenges both of these ideas. We argue that both of these ideas overlook or ignore the erosion of popular sovereignty from within states. We argue that engaging with, rather than evading, public debate on migration can potentially help to reinvigorate popular sovereignty.

Beta(1)-selective agonist (-)-1-(3,4-dimethoxyphenetylamino)-3-(3,4-dihydroxy)-2-propanol [(-)-RO363] differentially interacts with key amino acids responsible for beta(1)-selective binding in resting and active states.

(-)-1-(3,4-Dimethoxyphenetylamino)-3-(3,4-dihydroxy)-2-propanol [(-)-RO363] is a highly selective beta(1)-adrenergic receptor (beta(1)AR) agonist. To study the binding site of beta(1)-selective agonist, chimeric beta(1)/beta(2)ARs and Ala-substituted beta(1)ARs were constructed. Several key residues of beta(1)AR [Leu(110) and Thr(117) in transmembrane domain (TMD) 2], and Phe(359) in TMD 7] were found to be responsible for beta(1)-selective binding of (-)-RO363, as determined by competitive binding. Based on these results, we built a three-dimensional model of the binding domain for (-)-RO363. The model indicated that TMD 2 and TMD 7 of beta(1)AR form a binding pocket; the methoxyphenyl group of N-substituent of (-)-RO363 seems to locate within the cavity surrounded by Leu(110), Thr(117), and Phe(359). The amino acids Leu(110) and Phe(359) interact with the phenyl ring of (-)-RO363, whereas Thr(117) forms hydrogen bond with the methoxy group of (-)-RO363. To examine the interaction of these residues with beta(1)AR in an active state, each of the amino acids was changed to Ala in a constitutively active (CA)-beta(1)AR mutant. The degree of decrease in the affinity of CA-beta(1)AR for (-)-RO363 was essentially the same as that of wild-type beta(1)AR when mutated at Leu(110) and Thr(117). However, the affinity was decreased in Ala-substituted mutant of Phe(359) compared with that of wild-type beta(1)AR. These results indicated that Leu(110) and Thr(117) are necessary for the initial binding of (-)-RO363 with beta(1)-selectivity, and interaction of Phe(359) with the N-substituent of (-)-RO363 in an active state is stronger than in the resting state.

FGF-2 controls the differentiation of resident cardiac precursors into functional cardiomyocytes.

Recent evidence suggests that the heart possesses a greater regeneration capacity than previously thought. In the present study, we isolated undifferentiated precursors from the cardiac nonmyocyte cell population of neonatal hearts, expanded them in culture, and induced them to differentiate into functional cardiomyocytes. These cardiac precursors appear to express stem cell antigen-1 and demonstrate characteristics of multipotent precursors of mesodermal origin. Following infusion into normal recipients, these cells home to the heart and participate in physiological and pathophysiological cardiac remodeling. Cardiogenic differentiation in vitro and in vivo depends on FGF-2. Interestingly, this factor does not control the number of precursors but regulates the differentiation process. These findings suggest that, besides its angiogenic actions, FGF-2 could be used in vivo to facilitate the mobilization and differentiation of resident cardiac precursors in the treatment of cardiac diseases.

Report of Recommendations to the State University of Iowa on the Review of Selected General and Application Controls over the University's Human Resources Information System, June 7, 2005-July 29, 2005

Other Audit Reports - Regent Institutions

La surveillance active dans la prise en charge du cancer de la prostate précoce. [Active surveillance for early-stage prostate cancer]

Diagnostic and treatment management of prostate cancer at its initial stage continues to raise important debates within the involved medical community. To establish a protocol for active surveillance, a validated option in specific conditions of localised prostate cancer management for eight years, is a unique opportunity to gather different specialists in this field. This paper presents this concept.

Processing of tumor-associated antigen by the proteasomes of dendritic cells controls in vivo T-cell responses.

Dendritic cells are unique in their capacity to process antigens and prime naive CD8(+) T cells. Contrary to most cells, which express the standard proteasomes, dendritic cells express immunoproteasomes constitutively. The melanoma-associated protein Melan-A(MART1) contains an HLA-A2-restricted peptide that is poorly processed by melanoma cells expressing immunoproteasomes in vitro. Here, we show that the expression of Melan-A in dendritic cells fails to elicit T-cell responses in vitro and in vivo because it is not processed by the proteasomes of dendritic cells. In contrast, dendritic cells lacking immunoproteasomes induce strong anti-Melan-A T-cell responses in vitro and in vivo. These results suggest that the inefficient processing of self-antigens, such as Melan-A, by the immunoproteasomes of professional antigen-presenting cells prevents the induction of antitumor T-cell responses in vivo.

Report of Recommendations to the Iowa Department of Transportation on Review of Selected General and Application Controls over the Accounts Payable System, July 11, 2005 to August 3, 2005

State Audit Reports

The impotence of price controls: failed attempts to constrain pharmaceutical expenditures in Greece.

BACKGROUND: While the prices of pharmaceuticals are relatively low in Greece, expenditure on them is growing more rapidly than almost anywhere else in the European Union. OBJECTIVE: To describe and explain the rise in drug expenditures through decomposition of the increase into the contribution of changes in prices, in volumes and a product-mix effect. METHODS: The decomposition of the growth in pharmaceutical expenditures in Greece over the period 1991-2006 was conducted using data from the largest social insurance fund (IKA) that covers more than 50% of the population. RESULTS: Real drug spending increased by 285%, despite a 58% decrease in the relative price of pharmaceuticals. The increase in expenditure is mainly attributable to a switch to more innovative, but more expensive, pharmaceuticals, indicated by a product-mix residual of 493% in the decomposition. A rising volume of drugs also plays a role, and this is due to an increase in the number of prescriptions issued per doctor visit, rather than an increase in the number of visits or the population size. CONCLUSIONS: Rising pharmaceutical expenditures are strongly determined by physicians' prescribing behaviour, which is not subject to any monitoring and for which there are no incentives to be cost conscious.