8,289 research outputs found

    True high-order VCO-based ADC

    Get PDF
    A novel approach to use a voltage-controlled oscillator (VCO) as the first integrator of a high-order continuous-time delta-sigma modulator (CT-DSM) is presented. In the proposed architecture, the VCO is combined with a digital up-down counter to implement the first integrator of the CT-DSM. Thus, the first integrator is digital-friendly and hence can maximally benefit from technological scaling

    Computable randomness is about more than probabilities

    Get PDF
    We introduce a notion of computable randomness for infinite sequences that generalises the classical version in two important ways. First, our definition of computable randomness is associated with imprecise probability models, in the sense that we consider lower expectations (or sets of probabilities) instead of classical 'precise' probabilities. Secondly, instead of binary sequences, we consider sequences whose elements take values in some finite sample space. Interestingly, we find that every sequence is computably random with respect to at least one lower expectation, and that lower expectations that are more informative have fewer computably random sequences. This leads to the intriguing question whether every sequence is computably random with respect to a unique most informative lower expectation. We study this question in some detail and provide a partial answer

    Investigating the trade-off between the effectiveness and efficiency of process modeling

    Get PDF
    Despite recent efforts to improve the quality of process models, we still observe a significant dissimilarity in quality between models. This paper focuses on the syntactic condition of process models, and how it is achieved. To this end, a dataset of 121 modeling sessions was investigated. By going through each of these sessions step by step, a separate ‘revision’ phase was identified for 81 of them. Next, by cutting the modeling process off at the start of the revision phase, a partial process model was exported for these modeling sessions. Finally, each partial model was compared with its corresponding final model, in terms of time, effort, and the number of syntactic errors made or solved, in search for a possible trade-off between the effectiveness and efficiency of process modeling. Based on the findings, we give a provisional explanation for the difference in syntactic quality of process models

    Critical Behaviour of integrable mixed spins chains

    Full text link
    We construct a mixed spin 1/2 and SS integrable model and investigate its finite size properties. For a certain conformal invariant mixed spin system the central charge can be decomposed in terms of the conformal anomaly of two single integrable models of spin 1/2 and spin (S1/2)(S-1/2). We also compute the ground state energy and the sound velocity in the thermodynamic limit.Comment: This was the first correct calculation of the central charge in mixed integrable spin chains. For effects of a magnetic field see J.Phys.A:Math.Gen. 26 (1993) 730

    Surgical Menopause and Bilateral Oophorectomy:Effect of Estrogen-Progesterone and Testosterone Replacement Therapy on Psychological Well-being and Sexual Functioning; A Systematic Literature Review

    Get PDF
    Background: Besides experiencing vasomotor symptoms, after surgical menopause and bilateral salpingo-oophorectomy (BSO), women experience moderate to severe psychological and sexual symptoms. Aims: To systematically review and meta-analyze the effect of systemic hormone replacement therapy (sHRT) on psychological well-being and sexual functioning in women after surgical menopause and BSO. Methods: Medline/Pubmed, EMBASE and PsychInfo were systematically searched until November 2021. Randomized controlled trials investigating the effect of sHRT on psychological well-being and/or sexual functioning in surgically menopausal women and women after BSO were eligible for inclusion. Two independent authors performed study selection, risk of bias assessment and data extraction. Standardized mean differences (SMDs) were calculated. Outcomes: Primary outcomes for psychological well-being were defined as overall psychological well-being, depression, and anxiety. Primary outcomes for sexual functioning were defined as overall sexual functioning, sexual desire, and sexual satisfaction. All outcomes were assessed on short (≤12 weeks) or medium term (13–26 weeks). Results: Twelve studies were included. Estradiol had a beneficial effect on depressed mood on short term 3–6 years after surgery or 2 years (median) after surgery with high heterogeneity (SMD: −1.37, 95%CI: −2.38 to −0.37, P = .007, I2 79%). Testosterone had a beneficial effect on overall sexual functioning on short to medium term 4.6 years (mean) after surgery (SMD 0.38, 95%CI 0.11–0.65, I2 0%) and on sexual desire on medium term at least 3–12 months after surgery (SMD 0.38, 95%CI 0.19–0.56, I2 54%). For most studies, risk of bias was uncertain. Clinical implications: Estradiol may beneficially affect psychological symptoms after surgical menopause or BSO and testosterone might improve sexual desire and overall sexual functioning. Strengths and limitations: This review only included patient-reported outcomes, thereby reflected perceived and not simply objective symptoms in surgically menopausal women and women after BSO. The small number of studies highly varied in nature and bias could not be excluded, therefore our results should be interpreted with great caution. Conclusion: Independent randomized controlled clinical trials investigating the effects of estrogen-progesterone and testosterone on psychological and sexual symptoms after surgical menopause are needed. PROSPERO registration number: CRD42019136698

    The Evaluation of More Lymph Nodes in Colon Cancer Is Associated with Improved Survival in Patients of All Ages

    Get PDF
    BACKGROUND:Improvement in survival of patients with colon cancer is reduced in elderly patients compared to younger patients. The aim of this study was to investigate whether the removal of ≥ 12 lymph nodes can explain differences in survival rates between elderly and younger patients diagnosed with colon cancer. METHODS:In a population-based cohort study, all patients (N = 41,074) diagnosed with colon cancer stage I to III from 2003 through 2010 from the Netherlands Cancer Registry were included. Age groups were defined as < 66, 66-75 and > 75 years of age. Main outcome measures were overall and relative survival, the latter as a proxy for disease specific survival. RESULTS:Over an eight years time period there was a 41.2% increase in patients with ≥ 12 lymph nodes removed, whereas the percentage of patients with the presence of lymph node metastases remained stable (35.7% to 37.5%). After adjustment for patient and tumour characteristics and adjuvant chemotherapy, it was found that for patients in which ≥ 12 lymph nodes were removed compared to patients with < 12 lymph nodes removed, there was a statistically significant higher overall survival (< 66: HR: 0.858 (95% CI, 0.789-0.933); 66-75: HR: 0.763 (95% CI, 0.714-0.814); > 75: HR: 0.734 (95% CI, 0.700-0.771)) and relative survival (< 66: RER: 0.783 (95% CI, 0.708-0.865); 66-75: RER: 0.672 (95% CI, 0.611-0.739); > 75: RER: 0.621 (95% CI, 0.567-0.681)) in all three age groups. CONCLUSIONS:The removal of ≥ 12 lymph nodes is associated with an improvement in both overall and relative survival in all patients. This association was stronger in the elderly patient. The biology of this association needs further clarification

    Polarization of the WMAP Point Sources

    Get PDF
    The detection of polarized sources in the WMAP 5-year data is a very difficult task. The maps are dominated by instrumental noise and only a handful of sources show up as clear peaks in the Q and U maps. Optimal linear filters applied at the position of known bright sources detect with a high level of significance a polarized flux P from many more sources, but estimates of P are liable to biases. Using a new technique, named the "filtered fusion technique", we have detected in polarization, with a significance level greater than 99.99% in at least one WMAP channel, 22 objects, 5 of which, however, do not have a plausible low radio frequency counterpart and are therefore doubtful. Estimated polarized fluxes P < 400 mJy at 23 GHz were found to be severely affected by the Eddington bias. The corresponding polarized flux limit for Planck/LFI at 30 GHz, obtained via realistic simulations, is 300 mJy. We have also obtained statistical estimates of, or upper limits to the mean polarization degrees of bright WMAP sources at 23, 33, 41, and 61 GHz, finding that they are of a few percent.Comment: 10 pages, 6 figures. Accepted for publication in Ap

    A Neural Circuit Arbitrates between Persistence and Withdrawal in Hungry Drosophila

    No full text
    In pursuit of food, hungry animals mobilize significant energy resources and overcome exhaustion and fear. How need and motivation control the decision to continue or change behavior is not understood. Using a single fly treadmill, we show that hungry flies persistently track a food odor and increase their effort over repeated trials in the absence of reward suggesting that need dominates negative experience. We further show that odor tracking is regulated by two mushroom body output neurons (MBONs) connecting the MB to the lateral horn. These MBONs, together with dopaminergic neurons and Dop1R2 signaling, control behavioral persistence. Conversely, an octopaminergic neuron, VPM4, which directly innervates one of the MBONs, acts as a brake on odor tracking by connecting feeding and olfaction. Together, our data suggest a function for the MB in internal state-dependent expression of behavior that can be suppressed by external inputs conveying a competing behavioral drive
    corecore