Universal Polar Codes for More Capable and Less Noisy Channels and Sources

We prove two results on the universality of polar codes for source coding and channel communication. First, we show that for any polar code built for a source $P_{X,Z}$ there exists a slightly modified polar code - having the same rate, the same encoding and decoding complexity and the same error rate - that is universal for every source $P_{X,Y}$ when using successive cancellation decoding, at least when the channel $P_{Y|X}$ is more capable than $P_{Z|X}$ and $P_X$ is such that it maximizes $I(X;Y) - I(X;Z)$ for the given channels $P_{Y|X}$ and $P_{Z|X}$. This result extends to channel coding for discrete memoryless channels. Second, we prove that polar codes using successive cancellation decoding are universal for less noisy discrete memoryless channels.Comment: 10 pages, 3 figure

How to allocate scarce health resources without discriminating against people with disabilities

One widely used method for allocating health care resources involves the use of cost-effectiveness analysis (CEA) to rank treatments in terms of quality-adjusted life-years (QALYs) gained. CEA has been criticized for discriminating against people with disabilities by valuing their lives less than those of non-disabled people. Avoiding discrimination seems to lead to the ’QALY trap’: we cannot value saving lives equally and still value raising quality of life. This paper reviews existing responses to the QALY trap and argues that all are problematic. Instead, we argue that adopting a moderate form of prioritarianism avoids the QALY trap and disability discrimination

Swollen limbs and bone pain : a case report

A 50 year old man presented with peripheral oedema, abdominal distension and a pulmonary opacity on CXR. He subsequently perforated his sigmoid colon as a complication of diverticulitis with pericolic abscess. After colectomy his postoperative period was marked by severe hypokalaemia, metabolic alkalosis, hyperglycaemia and recurrent chest infections. Paraneoplastic Cushing's syndrome was diagnosed after finding elevated serum cortisol and ACTH levels. CT-guided biopsy of the lung lesion revealed small-cell carcinoma. Bone scan disclosed collapse of numerous thoracic vertebrae possibly due to osteoporosis or oncogenic osteomalacia. Treatment with steroid-synthesis blockers was commenced but the patient died before tumour-directed therapy could be started. Ectopic ACTH syndrome and oncogenic osteomalacia are discussed.peer-reviewe

Gender differences in paid and unpaid work: findings from a New Zealand birth cohort

This study uses data from a birth cohort of New Zealand-born 30-year-olds to examine gender differences in time use and satisfaction with time use. The specific aims of the study are: to examine gender difference in time spent in paid employment and unpaid work; to examine the extent to which males and females are satisfied with their time use

Blazes: Coordination Analysis for Distributed Programs

Distributed consistency is perhaps the most discussed topic in distributed systems today. Coordination protocols can ensure consistency, but in practice they cause undesirable performance unless used judiciously. Scalable distributed architectures avoid coordination whenever possible, but under-coordinated systems can exhibit behavioral anomalies under fault, which are often extremely difficult to debug. This raises significant challenges for distributed system architects and developers. In this paper we present Blazes, a cross-platform program analysis framework that (a) identifies program locations that require coordination to ensure consistent executions, and (b) automatically synthesizes application-specific coordination code that can significantly outperform general-purpose techniques. We present two case studies, one using annotated programs in the Twitter Storm system, and another using the Bloom declarative language.Comment: Updated to include additional materials from the original technical report: derivation rules, output stream label

Timing Measurements of the Relativistic Binary Pulsar PSR B1913+16

We present results of more than three decades of timing measurements of the first known binary pulsar, PSR B1913+16. Like most other pulsars, its rotational behavior over such long time scales is significantly affected by small-scale irregularities not explicitly accounted for in a deterministic model. Nevertheless, the physically important astrometric, spin, and orbital parameters are well determined and well decoupled from the timing noise. We have determined a significant result for proper motion, $\mu_{\alpha} = -1.43\pm0.13$, $\mu_{\delta}=-0.70\pm0.13$ mas yr$^{-1}$. The pulsar exhibited a small timing glitch in May 2003, with ${\Delta f}/f=3.7\times10^{-11}$, and a smaller timing peculiarity in mid-1992. A relativistic solution for orbital parameters yields improved mass estimates for the pulsar and its companion, m_1=1.4398\pm0.0002 \ M_{\sun} and m_2=1.3886\pm0.0002 \ M_{\sun}. The system's orbital period has been decreasing at a rate $0.997\pm0.002$ times that predicted as a result of gravitational radiation damping in general relativity. As we have shown before, this result provides conclusive evidence for the existence of gravitational radiation as predicted by Einstein's theory.Comment: Published in APJ, 722, 1030 (2010