Mandelbrot's stochastic time series models

I survey and illustrate the main time series models that Mandelbrot introduced into time series analysis in the 1960s and 1970s. I focus particularly on the members of the additive fractional stable family including Lévy flights and fractional Brownian motion (fBm), noting some of the less well‐known aspects of this family, such as the cases when the self‐similarity exponent H and the Hurst exponent J differ. I briefly discuss the role of multiplicative models in modeling the physics of cascades. I then recount the still little‐known story of Mandelbrot's work on fractional renewal models in the late 1960s, explaining how these differ from their more familiar fBm counterpart and form a “missing link” between fBm and the problem of random change points. I conclude by highlighting the frontier problem of damped fractional models

Gravitational wave background from sub-luminous GRBs: prospects for second and third generation detectors

We assess the detection prospects of a gravitational wave background associated with sub-luminous gamma-ray bursts (SL-GRBs). We assume that the central engines of a significant proportion of these bursts are provided by newly born magnetars and consider two plausible GW emission mechanisms. Firstly, the deformation-induced triaxial GW emission from a newly born magnetar. Secondly, the onset of a secular bar-mode instability, associated with the long lived plateau observed in the X-ray afterglows of many gamma-ray bursts (Corsi & Meszaros 2009a). With regards to detectability, we find that the onset of a secular instability is the most optimistic scenario: under the hypothesis that SL-GRBs associated with secularly unstable magnetars occur at a rate of (48; 80)Gpc^{-3}yr^{-1} or greater, cross-correlation of data from two Einstein Telescopes (ETs) could detect the GW background associated to this signal with a signal-to-noise ratio of 3 or greater after 1 year of observation. Assuming neutron star spindown results purely from triaxial GW emissions, we find that rates of around (130;350)Gpc^{-3}yr^{-1} will be required by ET to detect the resulting GW background. We show that a background signal from secular instabilities could potentially mask a primordial GW background signal in the frequency range where ET is most sen- sitive. Finally, we show how accounting for cosmic metallicity evolution can increase the predicted signal-to-noise ratio for background signals associated with SL-GRBs.Comment: Accepted by MNRA

Presence of D4 dopamine receptors in human prefrontal cortex: a postmortem study = Presença de receptores dopaminérgicos D4 em córtex cerebral humano: um estudo post-mortem

OBJECTIVE: The aim of our study was to explore the presence and the distribution of D4 dopamine receptors in postmortem human prefrontal cortex, by means of the binding of [³H]YM-09151-2, an antagonist that has equal affinity for D2, D3 and D4 receptors. It was therefore necessary to devise a unique assay method in order to distinguish and detect the D4 component. METHOD: Frontal cortex samples were harvested postmortem, during autopsy sessions, from 5 subjects. In the first assay, tissue homogenates were incubated with increasing concentrations of [³H]YM-09151-2, whereas L-745870, which has a high affinity for D4 and a low affinity for D2/D3 receptors, was used as the displacer. In the second assay, raclopride, which has a high affinity for D2/D3 receptors and a low affinity for D4 receptors, was used to block D2/D3. The L-745870 (500 nM) was added to both assays in order to determine the nonspecific binding. RESULTS: Our experiments revealed the presence of specific and saturable binding of [³H]YM-09151-2. The blockade of D2 and D3 receptors with raclopride ensured that the D4 receptors were labeled. The mean maximum binding capacity was 88 ± 25 fmol/mg protein, and the dissociation constant was 0.8 ± 0.4 nM. DISCUSSION AND CONCLUSIONS: Our findings, although not conclusive, suggest that the density of D4 receptors is low in the human prefrontal cortex

Fitoterápicos como coadjuvante no tratamento da síndrome metabólica: uma revisão integrativa

A síndrome metabólica é uma condição complexa caracterizada pela interação de diversos fatores de risco cardiovasculares e metabólicos. O tratamento convencional geralmente envolve modificações no estilo de vida e medicação. No entanto, o interesse crescente em terapias alternativas e complementares tem destacado o potencial dos fitoterápicos. Sumarizar estudos que avaliaram o uso de fitoterápicos como estratégia terapêutica para o tratamento síndrome metabólica. Metodologia: Trata-se de uma revisão integrativa de artigos indexados na base de dados PubMed, Capes Periódicos e Biblioteca Virtual em Saúde e Scielo, publicados entre os anos de 2017 a 2023, a partir da conjugação dos descritores “Fitoterápicos, “Síndrome metabólica”, “Obesidade” e “Fitoterapia”, nos idiomas português e inglês. Foram encontrados um total de 1.832 artigos, destes, 06 foram selecionados para revisão integrativa. O tempo de duração dos estudos, teve variação de 6 semanas até 26 semanas. Quanto aos principais fitoterápicos estudados, verificou-se que 50% (n = 3), utilizaram Camelia sinensis, 33,3% (n= 2) utilizaram Curcuma longa e 16,6% (n = 1) aplicaram em seus estudos o Allium sativum L. Outros fitoterápicos também incluídos foram: Linun usitatissimun L., Zingiber officinale, Capsicum spp, Trigonella foenum graecum e Citrus aurantium. As plantas medicinais demonstraram em estudos, sua capacidade de modular diversos aspectos metabólicos, como controle glicêmico, redução do colesterol e triglicerídeos, e melhoria da sensibilidade à insulina

Efficacy and Safety of High-Dose Rifampin in Pulmonary Tuberculosis. A Randomized Controlled Trial

Rationale: We examined whether increased rifampin doses could shorten standard therapy for tuberculosis without increased toxicity. Objectives: To assess the differences across three daily oral doses of rifampin in change in elimination rate of Mycobacterium tuberculosis in sputum and frequency of rifampin-related adverse events. Methods: We conducted a blinded, randomized, controlled phase 2 clinical trial of 180 adults with new smear-positive pulmonary tuberculosis, susceptible to isoniazid and rifampin. We randomized 1:1:1 to rifampin at 10, 15, and 20 mg/kg/d during the intensive phase. We report the primary efficacy and safety endpoints: change in elimination rate of M. tuberculosis log10 colony-forming units and frequency of grade 2 or higher rifampin-related adverse events. We report efficacy by treatment arm and by primary (area under the plasma concentration–time curve [AUC]/minimum inhibitory concentration [MIC]) and secondary (AUC) pharmacokinetic exposure. Measurements and Main Results: Each 5-mg/kg/d increase in rifampin dose resulted in differences of −0.011 (95% confidence interval, −0.025 to +0.002; P = 0.230) and −0.022 (95% confidence interval, −0.046 to −0.002; P = 0.022) log10 cfu/ml/d in the modified intention-to-treat and per-protocol analyses, respectively. The elimination rate in the per-protocol population increased significantly with rifampin AUC0–6 (P = 0.011) but not with AUC0–6/MIC99.9 (P = 0.053). Grade 2 or higher rifampin-related adverse events occurred with similar frequency across the three treatment arms: 26, 31, and 23 participants (43.3%, 51.7%, and 38.3%, respectively) had at least one event (P = 0.7092) up to 4 weeks after the intensive phase. Treatment failed or disease recurred in 11 participants (6.1%). Conclusions: Our findings of more rapid sputum sterilization and similar toxicity with higher rifampin doses support investigation of increased rifampin doses to shorten tuberculosis treatment

Anthocyanins in relation to nutrients, stomatal density, and yield of purple lettuce (Lactuca sativa L.) fertilized with compost based on bleaching earth

Abstract In Peru, in recent years, the gastronomic boom has stood out globally, which has increased the production of edible oil in the oil industries, generating too much bleaching land. This study investigated anthocyanins in relation to nutrients, stomata density and yield of purple lettuce nourished with bleaching soil-based compost. The objective was to analyze the concentration of anthocyanins as a function of nutrients, stomata density and yield of purple lettuce nourished with such compost. It is based on a methodology applied with an experimental approach; for which the statistical model of the Completely Randomized Block Design was used, consisting of 3 blocks and 5 treatments which were T1 with 0, T2 with 6, T3 with 8, T4 with 10 and T5 with 12 t/ha of compost based on bleaching soil and the doses were applied 15 days after transplanting. Total plant length, plant height, plant weight, commercial yield, and equatorial diameter were evaluated. Additionally, the concentration of nutrients in leaves (Nitrogen, potassium, phosphorus, calcium, magnesium, sulfur, molybdenum, iron, manganese, copper, zinc, boron, chlorides, and sodium), anthocyanin, stomatal density, and profitability. The results determined that T5 stood out in total plant length with 32 cm, plant height with 27 cm, plant weight with 200.27 g, commercial yield with 23.57 t/ha and equatorial diameter with 16.17 cm. Total nitrogen supply was 255.1 kg/ha. Nutrient concentrations in leaves were phosphorus, sulfur, molybdenum, manganese, copper, zinc and boron. Stomata density in leaves with 118 stomata/mm2. Profitability with 129% and anthocyanin concentration in T2 leaves with 89.25 mg/100g. It is concluded that adequate anthocyanin concentration in T5, with 62.86 mg/100 g, influenced the concentration of most nutrients and greater density of stomata in the leaves, acting as a defense mechanism against nutritional and environmental stress, obtaining higher yields, 30% higher compared to the control

Search for gravitational waves associated with fast radio bursts detected by CHIME/FRB during the LIGO-Virgo observing Run O3a

We search for gravitational-wave (GW) transients associated with fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project, during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC–2019 October 1 15:00 UTC). Triggers from 22 FRBs were analyzed with a search that targets both binary neutron star (BNS) and neutron star–black hole (NSBH) mergers. A targeted search for generic GW transients was conducted on 40 FRBs. We find no significant evidence for a GW association in either search. Given the large uncertainties in the distances of our FRB sample, we are unable to exclude the possibility of a GW association. Assessing the volumetric event rates of both FRB and binary mergers, an association is limited to 15% of the FRB population for BNS mergers or 1% for NSBH mergers. We report 90% confidence lower bounds on the distance to each FRB for a range of GW progenitor models and set upper limits on the energy emitted through GWs for a range of emission scenarios. We find values of order 1051–1057 erg for models with central GW frequencies in the range 70–3560 Hz. At the sensitivity of this search, we find these limits to be above the predicted GW emissions for the models considered. We also find no significant coincident detection of GWs with the repeater, FRB 20200120E, which is the closest known extragalactic FRB

Reconstruction and identification of tau lepton decays to hadrons and tau neutrino at CMS

This paper describes the algorithms used by the CMS experiment to reconstruct and identify tau to hadrons + tau neutrino decays during Run 1 of the LHC. The performance of the algorithms is studied in proton-proton collisions recorded at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 inverse femtobarns. The algorithms achieve an identification efficiency of 50-60%, with misidentification rates for quark and gluon jets, electrons, and muons between per mille and per cent levels.Comment: Replaced with published version. Added journal referenc

Reconstruction and identification of τ lepton decays to hadrons and ντ at CMS

This paper describes the algorithms used by the CMS experiment to reconstruct and identify tau -> hadrons + nu(tau) decays during Run 1 of the LHC. The performance of the algorithms is studied in proton-proton collisions recorded at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb(-1). The algorithms achieve an identification efficiency of 50-60%, with misidentification rates for quark and gluon jets, electrons, and muons between per mille and per cent levels