Quantum Error Correction via Convex Optimization

We show that the problem of designing a quantum information error correcting procedure can be cast as a bi-convex optimization problem, iterating between encoding and recovery, each being a semidefinite program. For a given encoding operator the problem is convex in the recovery operator. For a given method of recovery, the problem is convex in the encoding scheme. This allows us to derive new codes that are locally optimal. We present examples of such codes that can handle errors which are too strong for codes derived by analogy to classical error correction techniques.Comment: 16 page

Prediction of Severe Complications and Mortality in Patients Admitted to a Coronary Care Unit

The aim of this study was to design a statistical model which will predict death or life-threatening complications in patients admitted to Coronary Care Unit using data which is available at the time of presentation. The study included 3721 consecutive admissions over a period four year period. Predictive models were developed using logistic regression analysis (with data from 1000 patients) and their performance was assessed using receiver operating characteristic (ROC) curve analysis. The most useful model included nine data items and was tested on data from 2721 patients. These could be divided into four groups according to their calculated probability of developing a serious complication. The lowest risk group had a mortality of 0.05%, compared with 3.5%, 6.4% and 18.1% respectively in the higher risk groups (p1000 U/1) in the four groups was 14.1%, 21.2%, 46.9% and 51.5% respectively (p<0.001). The overall complication rates were 16.9%, 35.4%, 75.4% and 71.8% respectively (p<0.001)

Life history and morphological studies of Punctaria tenuissima (Chordariaceae, Phaeophyceae), a new record for the Azores

Copyright © 2010 by Walter de Gruyter.Punctaria tenuissima (Chordariaceae, Phaeophyceae) is reported for the first time from the Azores. Erect thalli were collected on the Island of Sa˜o Miguel; they were up to 3 cm long, flattened and often twisted. The plurilocular sporangia were formed from surface cells that were quadrate or rectangular in surface view. Unilocular sporangia were not observed in the field. In culture, the plurispores of P. tenuissima developed into Hecatonema-like, tufted, prostrate thalli that formed plurilocular sporangia. The plurispores of the prostrate thalli cultured at 158C with a long day (LD) photoperiod developed into new prostrate thalli, which in turn formed plurilocular sporangia. This cycle was repeated 5 times, resulting in several generations of reproductive prostrate thalli. When these cultures were cooled to 108C with a short day (SD) photoperiod, new erect thalli developed from the prostrate thalli resembling the thalli collected in the field. These erect blades produced unilocular and plurilocular sporangia on the same or on different thalli. The plurispores and unispores produced by the erect thalli at 108C under SD conditions once again developed into new prostrate thalli. This is the first report of unilocular sporangia formed in cultures of P. tenuissima. Sexual reproduction was not observed. The culture conditions, particularly temperature and daylength, appeared to influence the formation of erect blades. The Punctaria-like thalli were produced in 108C/SD conditions, whilst the Hecatonema-like thalli were produced under 108–158C/LD and SD conditions. These results are similar to those reported for P. tenuissima from other locations and suggest the occurrence of both direct and heteromorphic life histories in the Azorean algae

Example of function optimization via hybrid computation

Iterative techniques for function optimization have been considered extensivezy for use in all-digital computation. Relatively little has been done to take advantage of the much higher integration speed of hybrid computation systems. This paper demonstrates application of one simple procedure in a hybrid envi ronment and compares the results to those obtained by an efficient digital procedure. Even though a much more efficient procedure was used on the digital, time-saving factors between 8 and 2 were obtained via the simpler hybrid implementation. Since the dollar cost of the hybrid is much less than that of the digital, the hybrid has a large advantage per solution.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68324/2/10.1177_003754977302100204.pd

Artificial Intelligence and Human Error Prevention: A Computer Aided Decision Making Approach: Technical Report No. 4: Survey and Analysis of Research on Learning Systems from Artificial Intelligence

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryU.S. Department of Transportation / DOT FA79WA-4360 ABFederal Aviation Administratio

Epidemiologic situation of bovine brucellosis in the State of Mato Grosso, Brazil

Caracterizou-se a brucelose bovina em Mato Grosso por meio de um estudo transversal realizado em 2003 para auxiliar na implementação do Programa Nacional de Controle e Erradicação da Brucelose e Tuberculose. No Estado, estratificado em quatro circuitos pecuários, foram amostrados 13.684 animais, provenientes de 1.152 rebanhos. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e os soros reagentes foram testados pelo 2-mercaptoetanol (ME) e concomitantemente retestados pelo teste de Rosa Bengala para resultado conclusivo. As prevalências de focos e de animais infectados foram: 41,2% [38,0-44,4%] e 10,2% [7,4-13,1%], respectivamente. Nos circuitos produtivos, as prevalências de focos foram 36,9% [29,2-45,2%], 27,2% [22,8-32,1%], 40,4% [38,8-46,2%] e 50,3% [44,5-56,1%]; e as prevalências de animais 7,9% [3,0-12,9%], 4,1% [2,8-5,4%], 8,1% [5,2-11,1%] e 15,3% [9,2-21,3%], respectivamente, para os circuitos 1, 2, 3 e 4. Os fatores de risco (odds ratio, OR) associados à condição de foco no Estado foram: exploração de gado de corte (OR= 1,8 [1,2-2,5]), exploração mista (OR=1,8 [1,2-2,7]), número de fêmeas no rebanho de 11 a 50 (OR=4,8 [1,1-20,8]), número de fêmeas no rebanho acima de 51 (OR=6,8 [1,6-29,0]), ocorrência de aborto (OR=1,7 [1,3-2,2]). A brucelose está homogeneamente distribuída no Estado, o que permite uniformidade de medidas sanitárias. Adicionalmente, sugere-se a intensificação da vacinação de fêmeas para todo o Estado. _______________________________________________________________________________________________________ ABSTRACTA study to characterize bovine brucellosis in the State of Mato Grosso was carried out in 2003 in order to support the implementation of the National Program for the Control and Eradication of Bovine Brucellosis. The State was divided into four productive regions, and 13,684 bovines from 1,152 herds were sampled. The serum samples were screened for antibodies to Brucella spp. by the Rose-Bengal test (RBT) and all RBT-positive sera were re-tested by the 2-mercaptoethanol test (2-ME), and again by RBT for confirmation. The prevalence of infected herds and animals in the State of Mato Grosso were 41.2% [38.0-44.4%] and 10.2% [7.4-13.1%], respectively. In the productive regions, the prevalence of infected herds were 36.9% [29.2-45.2%], 27.2% [22.8-32.1%], 40.4% [38.8-46.2%], and 50.3% [44.5-56.1%], respectively; and the prevalence of infected animals were 7.9% [3.0-12.9%], 4.1% [2.8-5.4%], 8.1% [5.2-11.1%], and 15.3% [9.2-21.3%], respectively, for regions 1, 2, 3, and 4. The risk factors (odds ratio, OR) associated with the presence of the infection in the State were: beef cattle farming (OR=1.8 [1.2-2.5]), mixed (beef and dairy) cattle farming (OR=1.8 [1.2-2.7]), farms with 11 to 50 females (OR=4.8 [1.1-20.8]), farms with more than 51 females (OR=6.8 [1.6-29.0]), and occurrence of abortion (OR=1.7 [1.3-2.2]). Given that brucellosis is homogeneously distributed in the State, uniform sanitary measures might be adopted. As a homogeneous additional measure for the State, the intensification of female vaccination is suggested

Asteroseismic diagrams from a survey of solar-like oscillations with Kepler

Photometric observations made by the NASA Kepler Mission have led to a dramatic increase in the number of main-sequence and subgiant stars with detected solar-like oscillations. We present an ensemble asteroseismic analysis of 76 solar-type stars. Using frequencies determined from the Kepler time-series photometry, we have measured three asteroseismic parameters that characterize the oscillations: the large frequency separation (\Delta \nu), the small frequency separation between modes of l=0 and l=2 (\delta \nu_02), and the dimensionless offset (\epsilon). These measurements allow us to construct asteroseismic diagrams, namely the so-called C-D diagram of \delta \nu_02 versus \Delta \nu, and the recently re-introduced {\epsilon} diagram. We compare the Kepler results with previously observed solar-type stars and with theoretical models. The positions of stars in these diagrams places constraints on their masses and ages. Additionally, we confirm the observational relationship between {\epsilon} and T_eff that allows for the unambiguous determination of radial order and should help resolve the problem of mode identification in F stars.Comment: 6 pages, 5 figures, accepted for publication in The Astrophysical Journal Letter

FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK

Color categories: Evidence for the cultural relativity hypothesis

The question of whether language affects our categorization of perceptual continua is of particular interest for the domain of color where constraints on categorization have been proposed both within the visual system and in the visual environment. Recent research (Roberson, Davies, & Davidoff, 2000; Roberson et al., in press) found substantial evidence of cognitive color differences between different language communities, but concerns remained as to how representative might be a tiny, extremely remote community. The present study replicates and extends previous findings using additional paradigms among a larger community in a different visual environment. Adult semi-nomadic tribesmen in Southern Africa carried out similarity judgments, short-term memory and long-term learning tasks. They showed different cognitive organization of color to both English and another language with the five color terms. Moreover, Categorical Perception effects were found to differ even between languages with broadly similar color categories. The results provide further evidence of the tight relationship between language and cognition