Diagnostic and therapeutic approaches for nonmetastatic breast cancer in Canada, and their associated costs

In an era of fiscal restraint, it is important to evaluate the resources required to diagnose and treat serious illnesses. As breast cancer is the major malignancy affecting Canadian women, Statistics Canada has analysed the resources required to manage this disease in Canada, and the associated costs. Here we report the cost of initial diagnosis and treatment of nonmetastatic breast cancer, including adjuvant therapies. Treatment algorithms for Stages I, II, and III of the disease were derived by age group (< 50 or ≥ 50 years old), principally from Canadian cancer registry data, supplemented, where necessary, by the results of surveys of Canadian oncologists. Data were obtained on breast cancer incidence by age, diagnostic work-up, stage at diagnosis, initial treatment, follow-up practice, duration of hospitalization and direct care costs. The direct health care costs associated with ‘standard’ diagnostic and therapeutic approaches were calculated for a cohort of 17 700 Canadian women diagnosed in 1995. Early stage (Stages I and II) breast cancer represented 87% of all incident cases, with 77% of cases occurring in women ≥ 50 years. Variations were noted in the rate of partial vs total mastectomy, according to stage and age group. Direct costs for diagnosis and initial treatment ranged from $8014 for Stage II women ≥ 50 years old, to$10 897 for Stage III women < 50 years old. Except for Stage III women < 50 years old, the largest expenditure was for hospitalization for surgery, followed by radiotherapy costs. Chemotherapy was the largest cost component for Stage III women < 50 years old. This report describes the cost of diagnosis and initial treatment of nonmetastatic breast cancer in Canada, assuming current practice patterns. A second report will describe the lifetime costs of treating all stages of breast cancer. These data will then be incorporated into Statistics Canada's Population Health Model (POHEM) to perform cost-effectiveness studies of new therapeutic interventions for breast cancer, such as the cost-effectiveness of day surgery, or of radiotherapy to all breast cancer patients undergoing breast surgery. © 1999 Cancer Research Campaig

Measurements in two bases are sufficient for certifying high-dimensional entanglement

High-dimensional encoding of quantum information provides a promising method of transcending current limitations in quantum communication. One of the central challenges in the pursuit of such an approach is the certification of high-dimensional entanglement. In particular, it is desirable to do so without resorting to inefficient full state tomography. Here, we show how carefully constructed measurements in two bases (one of which is not orthonormal) can be used to faithfully and efficiently certify bipartite high-dimensional states and their entanglement for any physical platform. To showcase the practicality of this approach under realistic conditions, we put it to the test for photons entangled in their orbital angular momentum. In our experimental setup, we are able to verify 9-dimensional entanglement for a pair of photons on a 11-dimensional subspace each, at present the highest amount certified without any assumptions on the state.Comment: 11+14 pages, 2+7 figure

A quantum spin transducer based on nano electro-mechancial resonator arrays

Implementation of quantum information processing faces the contradicting requirements of combining excellent isolation to avoid decoherence with the ability to control coherent interactions in a many-body quantum system. For example, spin degrees of freedom of electrons and nuclei provide a good quantum memory due to their weak magnetic interactions with the environment. However, for the same reason it is difficult to achieve controlled entanglement of spins over distances larger than tens of nanometers. Here we propose a universal realization of a quantum data bus for electronic spin qubits where spins are coupled to the motion of magnetized mechanical resonators via magnetic field gradients. Provided that the mechanical system is charged, the magnetic moments associated with spin qubits can be effectively amplified to enable a coherent spin-spin coupling over long distances via Coulomb forces. Our approach is applicable to a wide class of electronic spin qubits which can be localized near the magnetized tips and can be used for the implementation of hybrid quantum computing architectures

The decatenation checkpoint

The decatenation checkpoint delays entry into mitosis until the chromosomes have been disentangled. Deficiency in or bypass of the decatenation checkpoint can cause chromosome breakage and nondisjunction during mitosis, which results in aneuploidy and chromosome rearrangements in the daughter cells. A deficiency in the decatenation checkpoint has been reported in lung and bladder cancer cell lines and may contribute to the accumulation of chromosome aberrations that commonly occur during tumour progression. A checkpoint deficiency has also been documented in cultured stem and progenitor cells, and cancer stem cells are likely to be derived from stem and progenitor cells that lack an effective decatenation checkpoint. An inefficient decatenation checkpoint is likely to be a source of the chromosome aberrations that are common features of most tumours, but an inefficient decatenation checkpoint in cancer stem cells could also provide a potential target for chemotherapy

Phenotypic Variation and Bistable Switching in Bacteria

Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.

Multiday expected shortfall under generalized t distributions : evidence from global stock market

We apply seven alternative t-distributions to estimate the market risk measures Value at Risk (VaR) and its extension Expected Shortfall (ES). Of these seven, the twin t-distribution (TT) of Baker and Jackson (2014) and generalized asymmetric distribution (GAT) of Baker (2016) are applied for the first time to estimate market risk. We analytically estimate VaR and ES over one-day horizon and extend this to multi-day horizon using Monte Carlo simulation. We find that taken together TT and GAT distributions provide the best back-testing results across individual confidence levels and horizons for majority of scenarios. Moreover, we find that with the lengthening of time horizon, TT and GAT models performs well, such that at the ten-day horizon, GAT provides the best back-testing results for all of the five indices and the TT model provides the second best results, irrespective period of study and confidence level

Electron spin coherence exceeding seconds in high purity silicon

Silicon is undoubtedly one of the most promising semiconductor materials for spin-based information processing devices. Its highly advanced fabrication technology facilitates the transition from individual devices to large-scale processors, and the availability of an isotopically-purified $^{28}$Si form with no magnetic nuclei overcomes what is a main source of spin decoherence in many other materials. Nevertheless, the coherence lifetimes of electron spins in the solid state have typically remained several orders of magnitude lower than what can be achieved in isolated high-vacuum systems such as trapped ions. Here we examine electron spin coherence of donors in very pure $^{28}$Si material, with a residual $^{29}$Si concentration of less than 50 ppm and donor densities of $10^{14-15}$ per cm$^3$. We elucidate three separate mechanisms for spin decoherence, active at different temperatures, and extract a coherence lifetime $T_2$ up to 2 seconds. In this regime, we find the electron spin is sensitive to interactions with other donor electron spins separated by ~200 nm. We apply a magnetic field gradient in order to suppress such interactions and obtain an extrapolated electron spin $T_2$ of 10 seconds at 1.8 K. These coherence lifetimes are without peer in the solid state by several orders of magnitude and comparable with high-vacuum qubits, making electron spins of donors in silicon ideal components of a quantum computer, or quantum memories for systems such as superconducting qubits.Comment: 18 pages, 4 figures, supplementary informatio

Hypnotic analgesia reduces brain responses to pain seen in others.

Brain responses to pain experienced by oneself or seen in other people show consistent overlap in the pain processing network, particularly anterior insula, supporting the view that pain empathy partly relies on neural processes engaged by self-nociception. However, it remains unresolved whether changes in one's own pain sensation may affect empathic responding to others' pain. Here we show that inducing analgesia through hypnosis leads to decreased responses to both self and vicarious experience of pain. Activations in the right anterior insula and amygdala were markedly reduced when participants received painful thermal stimuli following hypnotic analgesia on their own hand, but also when they viewed pictures of others' hand in pain. Functional connectivity analysis indicated that this hypnotic modulation of pain responses was associated with differential recruitment of right prefrontal regions implicated in selective attention and inhibitory control. Our results provide novel support to the view that self-nociception is involved during empathy for pain, and demonstrate the possibility to use hypnotic procedures to modulate higher-level emotional and social processes

Survey of A_LT' asymmetries in semi-exclusive electron scattering on He4 and C12

Single spin azimuthal asymmetries A_LT' were measured at Jefferson Lab using 2.2 and 4.4 GeV longitudinally polarized electrons incident on He4 and C12 targets in the CLAS detector. A_LT' is related to the imaginary part of the longitudinal-transverse interference and in quasifree nucleon knockout it provides an unambiguous signature for final state interactions (FSI). Experimental values of A_LT' were found to be below 5%, typically |A_LT'| < 3% for data with good statistical precision. Optical Model in Eikonal Approximation (OMEA) and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations are shown to be consistent with the measured asymmetries.Comment: 9 pages, 5 figure