Symmetric equilibria in double auctions with markdown buyers and markup sellers

Zhan and Friedman (2007) study double auctions where buyers and sellers are constrained to using simple markdown and markup rules. In spite of the alleged symmetry in roles and assumptions, buyers are shown to have the upper hand both in the call market and in the continuous double auction. We replicate the study and show that their formulation of the sellers’ markup strategies, while seemingly natural, exhibits a hidden asymmetry.We introduce a symmetric set of markup strategies for the sellers and show how it explains away the paradox of buyers’ advantage in three different double-sided market protocols

Unknown Quantum States: The Quantum de Finetti Representation

We present an elementary proof of the quantum de Finetti representation theorem, a quantum analogue of de Finetti's classical theorem on exchangeable probability assignments. This contrasts with the original proof of Hudson and Moody [Z. Wahrschein. verw. Geb. 33, 343 (1976)], which relies on advanced mathematics and does not share the same potential for generalization. The classical de Finetti theorem provides an operational definition of the concept of an unknown probability in Bayesian probability theory, where probabilities are taken to be degrees of belief instead of objective states of nature. The quantum de Finetti theorem, in a closely analogous fashion, deals with exchangeable density-operator assignments and provides an operational definition of the concept of an ``unknown quantum state'' in quantum-state tomography. This result is especially important for information-based interpretations of quantum mechanics, where quantum states, like probabilities, are taken to be states of knowledge rather than states of nature. We further demonstrate that the theorem fails for real Hilbert spaces and discuss the significance of this point.Comment: 30 pages, 2 figure

Nomenclature for renal replacement therapy and blood purification techniques in critically ill patients: practical applications

This article reports the conclusions of the second part of a consensus expert conference on the nomenclature of renal replacement therapy (RRT) techniques currently utilized to manage acute kidney injury and other organ dysfunction syndromes in critically ill patients. A multidisciplinary approach was taken to achieve harmonization of definitions, components, techniques, and operations of the extracorporeal therapies. The article describes the RRT techniques in detail with the relevant technology, procedures, and phases of treatment and key aspects of volume management/fluid balance in critically ill patients. In addition, the article describes recent developments in other extracorporeal therapies, including therapeutic plasma exchange, multiple organ support therapy, liver support, lung support, and blood purification in sepsis. This is a consensus report on nomenclature harmonization in extracorporeal blood purification therapies, such as hemofiltration, plasma exchange, multiple organ support therapies, and blood purification in sepsis

The p53 Codon 72 Pro/Pro Genotype Identifies Poor-Prognosis Neuroblastoma Patients: Correlation with Reduced Apoptosis and Enhanced Senescence by the p53-72P Isoform.

The p53 gene is rarely mutated in neuroblastoma, but codon 72 polymorphism that modulates its proapoptotic activity might influence cancer risk and clinical outcome. We investigated whether this polymorphism affects neuroblastoma risk and disease outcome and assessed the biologic effects of the p53-72R and p53-72P isoforms in p53-null cells. Comparison of 288 healthy subjects and 286 neuroblastoma patients revealed that the p53-72 polymorphism had no significant impact on the risk of developing neuroblastoma; however, patients with the Pro/Pro genotype had a shorter survival than those with the Arg/Arg or the Arg/Pro genotypes even in the stage 3 and 4 subgroup without MYCN amplification. By Cox regression analysis, the p53 Pro/Pro genotype seems to be an independent marker of poor prognosis (hazard ratio = 2.74; 95% confidence interval = 1.14\u20136.55, P = .014) together with clinical stage, MYCN status, and age at diagnosis. In vitro, p53-72P was less effective than p53-72R in inducing apoptosis and inhibiting survival of p53-null LAN-1 cells treated with etoposide, topotecan, or ionizing radiation but not taxol. By contrast, p53-72P was more effective in promoting p21-dependent accelerated senescence, alone or in the presence of etoposide. Thus, the p53-72 Pro/Pro genotype might be a marker of poor outcome independent of MYCN amplification, possibly improving risk stratification. Moreover, the lower apoptosis and the enhanced accelerated senescence by the p53-72P isoform in response to DNA damage suggest that patients with neuroblastoma with the p53-72 Pro/Pro genotype may benefit from therapeutic protocols that do not rely only on cytotoxic drugs that function, in part, through p53 activation

Home mechanical ventilation patients: a retrospective survey to identify level of burden in real life

Background and Aim. Home care for patients under home mechanical ventilation (HMV) may cause dramatic physical and economic burden in addition to the burden of time on family/caregivers and health care service (HCS) with difficult resource allocation decision-making. Our aims were: 1. To identify conditions causing major care burden in managing HMV patients according to family and payer’s perspectives related to characteristics of the disease, dependency and accessibility; and 2. To find, if any, differences among diseases. Methods. A questionnaire was sent to eight pulmonary centres to identify factors connected with the greater care burden. Retrospective data of 792 patients still alive and in HMV was reviewed. Results. Compared to neuromuscular disorders (NM) and chest wall deformities, the COPD group have presented a statistically greater number of hospitalisations/yr (1.37 ± 0.77), greater length of stay (13 ± 10 days), higher number of outpatient visits/yr (2.55 ± 1.73) or emergency room accesses/ yr (0.74 ± 1.08). Patients with NM diseases need more home care. The prevalence of one, two and three among five selected burden criteria (needs of MV > 12 hrs/day, tracheotomy, high dependency, distance from hospital, frequent hospitalisations) was respectively 19%, 30% and 33% of the cases; the NM was the group most represented. Conclusions. In HMV patients: 1. underlying disease, level of their dependency, hours spent under MV, presence of tracheotomy, home distance from hospital, hospital accesses are the causes of major care burden; and 2. as a novelty we have demonstrated that more than fifty percent of them present two or three contemporaneous criteria selected as care burden, being NM and COPD patients the most representative group necessitating of family’s and HCS’s care respectively

Home mechanical ventilation patients: a retrospective survey to identify level of burden in real life

Background and Aim. Home care for patients under home mechanical ventilation (HMV) may cause dramatic physical and economic burden in addition to the burden of time on family/caregivers and health care service (HCS) with difficult resource allocation decision-making. Our aims were: 1. To identify conditions causing major care burden in managing HMV patients according to family and payer's perspectives related to characteristics of the disease, dependency and accessibility; and 2. To find, if any, differences among diseases. Methods. A questionnaire was sent to eight pulmonary centres to identify factors connected with the greater care burden. Retrospective data of 792 patients still alive and in HMV was reviewed. Results. Compared to neuromuscular disorders (NM) and chest wall deformities, the COPD group have presented a statistically greater number of hospitalisations/yr (1.37 ± 0.77), greater length of stay (13 ± 10 days), higher number of outpatient visits/yr (2.55 ± 1.73) or emergency room accesses/ yr (0.74 ± 1.08). Patients with NM diseases need more home care. The prevalence of one, two and three among five selected burden criteria (needs of MV > 12 hrs/day, tracheotomy, high dependency, distance from hospital, frequent hospitalisations) was respectively 19%, 30% and 33% of the cases; the NM was the group most represented. Conclusions. In HMV patients: 1. underlying disease, level of their dependency, hours spent under MV, presence of tracheotomy, home distance from hospital, hospital accesses are the causes of major care burden; and 2. as a novelty we have demonstrated that more than fifty percent of them present two or three contemporaneous criteria selected as care burden, being NM and COPD patients the most representative group necessitating of family's and HCS's care respectively

Long-fiber carbon nanotubes replicate asbestos-induced mesothelioma with disruption of the tumor suppressor gene Cdkn2a ( Ink4a/Arf )

Mesothelioma is a fatal tumor of the pleura and is strongly associated with asbestos exposure. The molecular mechanisms underlying the long latency period of mesothelioma and driving carcinogenesis are unknown. Moreover, late diagnosis means that mesothelioma research is commonly focused on end-stage disease. Although disruption of the CDKN2A (INK4A/ARF) locus has been reported in end-stage disease, information is lacking on the status of this key tumor suppressor gene in pleural lesions preceding mesothelioma. Manufactured carbon nanotubes (CNTs) are similar to asbestos in terms of their fibrous shape and biopersistent properties and thus may pose an asbestos-like inhalation hazard. Here we show that instillation of either long CNTs or long asbestos fibers into the pleural cavity of mice induces mesothelioma that exhibits common key pro-oncogenic molecular events throughout the latency period of disease progression. Sustained activation of pro-oncogenic signaling pathways, increased proliferation, and oxidative DNA damage form a common molecular signature of long-CNT- and long-asbestos-fiber-induced pathology. We show that hypermethylation of p16/Ink4a and p19/Arf in CNT- and asbestos-induced inflammatory lesions precedes mesothelioma; this results in silencing of Cdkn2a (Ink4a/Arf) and loss of p16 and p19 protein, consistent with epigenetic alterations playing a gatekeeper role in cancer. In end-stage mesothelioma, silencing of p16/Ink4a is sustained and deletion of p19/Arf is detected, recapitulating human disease. This study addresses the long-standing question of which early molecular changes drive carcinogenesis during the long latency period of mesothelioma development and shows that CNT and asbestos pose a similar health hazard

Increased somatic mutation burdens in normal human cells due to defective DNA polymerases.

Funder: Wellcome PhD StudentshipFunder: Jean Shank/Pathological Society Intermediate FellowshipFunder: Wellcome Clinical PhD fellowshipMutation accumulation in somatic cells contributes to cancer development and is proposed as a cause of aging. DNA polymerases Pol ε and Pol δ replicate DNA during cell division. However, in some cancers, defective proofreading due to acquired POLE/POLD1 exonuclease domain mutations causes markedly elevated somatic mutation burdens with distinctive mutational signatures. Germline POLE/POLD1 mutations cause familial cancer predisposition. Here, we sequenced normal tissue and tumor DNA from individuals with germline POLE/POLD1 mutations. Increased mutation burdens with characteristic mutational signatures were found in normal adult somatic cell types, during early embryogenesis and in sperm. Thus human physiology can tolerate ubiquitously elevated mutation burdens. Except for increased cancer risk, individuals with germline POLE/POLD1 mutations do not exhibit overt features of premature aging. These results do not support a model in which all features of aging are attributable to widespread cell malfunction directly resulting from somatic mutation burdens accrued during life

Machine Learning in Automated Text Categorization

The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert manpower, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey