Tailoring discrete quantum walk dynamics via extended initial conditions: Towards homogeneous probability distributions

We study the evolution of initially extended distributions in the coined quantum walk on the line by analyzing the dispersion relation of the process and its associated wave equations. This allows us, in particular, to devise an initially extended condition leading to a uniform probability distribution whose width increases linearly with time, with increasing homogeneity.Comment: 4 pages, 2 figure

Intercomparison of regional-scale hydrological models and climate change impacts projected for 12 large river basins worldwide—a synthesis

An intercomparison of climate change impacts projected by nine regional-scale hydrological models for 12 large river basins on all continents was performed, and sources of uncertainty were quantified in the framework of the ISIMIP project. The models ECOMAG, HBV, HYMOD, HYPE, mHM, SWAT, SWIM, VIC and WaterGAP3 were applied in the following basins: Rhine and Tagus in Europe, Niger and Blue Nile in Africa, Ganges, Lena, Upper Yellow and Upper Yangtze in Asia, Upper Mississippi, MacKenzie and Upper Amazon in America, and Darling in Australia. The model calibration and validation was done using WATCH climate data for the period 1971–2000. The results, evaluated with 14 criteria, are mostly satisfactory, except for the low flow. Climate change impacts were analyzed using projections from five global climate models under four representative concentration pathways. Trends in the period 2070–2099 in relation to the reference period 1975–2004 were evaluated for three variables: the long-term mean annual flow and high and low flow percentiles Q10 and Q90, as well as for flows in three months high- and low-flow periods denoted as HF and LF. For three river basins: the Lena, MacKenzie and Tagus strong trends in all five variables were found (except for Q10 in the MacKenzie); trends with moderate certainty for three to five variables were confirmed for the Rhine, Ganges and Upper Mississippi; and increases in HF and LF were found for the Upper Amazon, Upper Yangtze and Upper Yellow. The analysis of projected streamflow seasonality demonstrated increasing streamflow volumes during the high-flow period in four basins influenced by monsoonal precipitation (Ganges, Upper Amazon, Upper Yangtze and Upper Yellow), an amplification of the snowmelt flood peaks in the Lena and MacKenzie, and a substantial decrease of discharge in the Tagus (all months). The overall average fractions of uncertainty for the annual mean flow projections in the multi-model ensemble applied for all basins were 57% for GCMs, 27% for RCPs, and 16% for hydrological models.Intercomparison of regional-scale hydrological models and climate change impacts projected for 12 large river basins worldwide—a synthesispublishedVersio

Prevalencia de parásitos gastrointestinales en equinos y factores de riesgo asociados en varias zonas de Antioquia, Colombia

ABSTRACT: There are few reports on the prevalence of gastrointestinal parasites in equines in Colombia. In this study, 946 horses were sampled from a total of 204 farms in the municipalities of Rionegro and those that comprise the Valle de Aburrá, in the department of Antioquia. Fecal samples were taken directly from the rectum and processed by the McMaster, Baermann and Graham techniques. The prevalence of parasites at the farm level was 56.3% for Strongylidae, 10.7% for Strongyloides spp, 2.8% for Oxyuridae and 0.3% for Dictyocaulus spp. From a practical point of view, the most pathogenic parasites and of greatest resistance concern were the Cyathostomids, which are included within the Strongylidae and whose prevalence was greater than 50%. The OR of presenting Strongylidae was 49% lower in equines that participated in fairs compared to those that did not. The OR of presenting Strongylidae was 56% lower in equines that use stables than those not being stalled. Also, the OR of being positive to Oxyuris equi was 88% lower in animals that participate in fairs compared to those that did not, and was 3.66 times higher in equines with body condition ≤ 2 in comparison with those of body condition ≥3. Based on this information, it is important to initiate studies that evaluate the state of antihelminthic resistance and the relationship between parasitic load and clinical condition in order to determine the real impact of these parasites on the equines of these regions.RESUMEN: Existen pocos reportes de la prevalencia de parásitos gastrointestinales en equinos en Colombia. En este estudio se muestrearon 946 caballos de un total de 204 predios en los municipios de Rionegro y los que comprenden el Valle de Aburra departamento de Antioquia. La materia fecal fue tomada directamente del recto y procesada por las tecnicas de McMaster, Baermann y Graham. La prevalencia de parásitos a nivel de predios fue del 56,3% para Strongylidae, 10,7% para Strongyloides spp, 2,8% para Oxyuridae y 0,3% para Dictyocaulus spp. Desde el punto de vista práctico, los más patogénicos y de mayor problema de resistencia son los Cyathostomidos, que se incluyen dentro de los Strongylidae y cuya prevalencia fue superior al 50%. El OR de presentar Strongylidae es 49% menor en equinos que participan en ferias en comparación con los que no lo hacen. El OR de presentar Strongylidae es 56% menor en equinos que usan pesebrera en comparación con los que no la usan. Por su parte, el OR de ser positivo a Oxyuris equi es 88% menor en animales que salen a ferias en comparación con los que no salen a feria y el OR de ser positivo a Oxyuris equi es 3,66 veces mayor en equinos con condición corporal ≤2 en comparación con equinos de condición corporal ≥3. Con base en esta información es importante iniciar estudios de resistencia a antihelminticos y evaluar la relación entre la carga parasitaria y las posibles afecciones clínicas para así determinar el impacto real de estas parasitosis en los equinos de estas regiones

Prevalence of Babesia Caballi, Theileria Equi and Trypanosomiasis and analysis of risk factors in horses of Antioquia, Colombia

ABSTRACT: This research was carried out due to the little existing national information on equine hemoparasites; the objective was to determine babesiosis and trypanosomiasis prevalence in the Aburrá Valley and Rionegro Antioquia (Colombia) as well as some risk factors associated with the seropositivitie of these diseases. In 223 lots with a population of 1.008 equine venous blood sample was taken for serological diagnosis and molecular. Epidemiological information was obtained through the application of a survey addressed to persons in charge of the animals. For the statistical analysis, Chi square of independence or Fisher’s Exact Test was applied when necessary. For the bivariate associations, risk estimates (OR) were calculated by explanatory variable, with their respective 95% confidence intervals (95% CI).It was found a prevalence of 11.9% for babesiosis and 1.9% for trypanosomiasis and as protection factor found the fact of going to trade fairs. Geographic location, sex and being neutered, be positive for Equine Infectious Anemia (AIE), strongyles or oxiurus was a risk factor for piroplasmosis. For Trypanosomiasis the risk factor was to be infested with ticks Dermacentor nitens or be mule. Methods of active epidemiological surveillance should be reinforced, especially in cases of continuous mobilization of equines or development of events that involve massive presence of horses.RESUMEN: La investigación se llevó a cabo debido a la poca información nacional existente en hemoparásitos equinos y su objetivo fue determinar la prevalencia de babesiosis y tripanosomiasis, en el Valle de Aburrá y Rionegro, municipios de Antioquia (Colombia), así como algunos factores de riesgo asociados a la presentación de seropositividad, a estas enfermedades. En 223 predios, con una población de 1.008 equinos, se tomó muestra de sangre venosa, para realizar el diagnóstico serológico y molecular. La información epidemiológica fue obtenida a través de la aplicación de una encuesta dirigida a las personas a cargo de los animales. Para el análisis estadístico, se aplicó Chi cuadrado de independencia y la Prueba Exacta de Fisher, cuando fue necesario. Para las asociaciones bivariadas, se calcularon estimaciones del riesgo (OR) por variable explicativa, con sus respectivos intervalos de confianza, del 95% (I.C. 95%). Se encontró una prevalencia del 11,9%, para babesiosis y de 1,9%, para tripanosomiasis; como factor de protección, se encontró el hecho de salir a una feria. Para la piroplasmosis, el lugar geográfico, el sexo, estar castrado, ser positivos a Anemia Infecciosa Equina (AIE), estrongilidos u oxiurus fueron factores de riesgo. Para tripanosomiasis, el factor de riesgo fue estar infestado con Dermacentor nitens o ser mular. Se deben reforzar métodos de vigilancia epidemiológica activa, sobre todo, en casos de movilización continua de equinos o desarrollo de eventos, que involucren presencia masiva de ejemplares

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Spontaneous Breathing in Early Acute Respiratory Distress Syndrome: Insights From the Large Observational Study to UNderstand the Global Impact of Severe Acute Respiratory FailurE Study

OBJECTIVES: To describe the characteristics and outcomes of patients with acute respiratory distress syndrome with or without spontaneous breathing and to investigate whether the effects of spontaneous breathing on outcome depend on acute respiratory distress syndrome severity. DESIGN: Planned secondary analysis of a prospective, observational, multicentre cohort study. SETTING: International sample of 459 ICUs from 50 countries. PATIENTS: Patients with acute respiratory distress syndrome and at least 2 days of invasive mechanical ventilation and available data for the mode of mechanical ventilation and respiratory rate for the 2 first days. INTERVENTIONS: Analysis of patients with and without spontaneous breathing, defined by the mode of mechanical ventilation and by actual respiratory rate compared with set respiratory rate during the first 48 hours of mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Spontaneous breathing was present in 67% of patients with mild acute respiratory distress syndrome, 58% of patients with moderate acute respiratory distress syndrome, and 46% of patients with severe acute respiratory distress syndrome. Patients with spontaneous breathing were older and had lower acute respiratory distress syndrome severity, Sequential Organ Failure Assessment scores, ICU and hospital mortality, and were less likely to be diagnosed with acute respiratory distress syndrome by clinicians. In adjusted analysis, spontaneous breathing during the first 2 days was not associated with an effect on ICU or hospital mortality (33% vs 37%; odds ratio, 1.18 [0.92-1.51]; p = 0.19 and 37% vs 41%; odds ratio, 1.18 [0.93-1.50]; p = 0.196, respectively ). Spontaneous breathing was associated with increased ventilator-free days (13 [0-22] vs 8 [0-20]; p = 0.014) and shorter duration of ICU stay (11 [6-20] vs 12 [7-22]; p = 0.04). CONCLUSIONS: Spontaneous breathing is common in patients with acute respiratory distress syndrome during the first 48 hours of mechanical ventilation. Spontaneous breathing is not associated with worse outcomes and may hasten liberation from the ventilator and from ICU. Although these results support the use of spontaneous breathing in patients with acute respiratory distress syndrome independent of acute respiratory distress syndrome severity, the use of controlled ventilation indicates a bias toward use in patients with higher disease severity. In addition, because the lack of reliable data on inspiratory effort in our study, prospective studies incorporating the magnitude of inspiratory effort and adjusting for all potential severity confounders are required

Identifying associations between diabetes and acute respiratory distress syndrome in patients with acute hypoxemic respiratory failure: an analysis of the LUNG SAFE database

Background: Diabetes mellitus is a common co-existing disease in the critically ill. Diabetes mellitus may reduce the risk of acute respiratory distress syndrome (ARDS), but data from previous studies are conflicting. The objective of this study was to evaluate associations between pre-existing diabetes mellitus and ARDS in critically ill patients with acute hypoxemic respiratory failure (AHRF). Methods: An ancillary analysis of a global, multi-centre prospective observational study (LUNG SAFE) was undertaken. LUNG SAFE evaluated all patients admitted to an intensive care unit (ICU) over a 4-week period, that required mechanical ventilation and met AHRF criteria. Patients who had their AHRF fully explained by cardiac failure were excluded. Important clinical characteristics were included in a stepwise selection approach (forward and backward selection combined with a significance level of 0.05) to identify a set of independent variables associated with having ARDS at any time, developing ARDS (defined as ARDS occurring after day 2 from meeting AHRF criteria) and with hospital mortality. Furthermore, propensity score analysis was undertaken to account for the differences in baseline characteristics between patients with and without diabetes mellitus, and the association between diabetes mellitus and outcomes of interest was assessed on matched samples. Results: Of the 4107 patients with AHRF included in this study, 3022 (73.6%) patients fulfilled ARDS criteria at admission or developed ARDS during their ICU stay. Diabetes mellitus was a pre-existing co-morbidity in 913 patients (22.2% of patients with AHRF). In multivariable analysis, there was no association between diabetes mellitus and having ARDS (OR 0.93 (0.78-1.11); p = 0.39), developing ARDS late (OR 0.79 (0.54-1.15); p = 0.22), or hospital mortality in patients with ARDS (1.15 (0.93-1.42); p = 0.19). In a matched sample of patients, there was no association between diabetes mellitus and outcomes of interest. Conclusions: In a large, global observational study of patients with AHRF, no association was found between diabetes mellitus and having ARDS, developing ARDS, or outcomes from ARDS. Trial registration: NCT02010073. Registered on 12 December 2013

Epidemiology and patterns of tracheostomy practice in patients with acute respiratory distress syndrome in ICUs across 50 countries

Background: To better understand the epidemiology and patterns of tracheostomy practice for patients with acute respiratory distress syndrome (ARDS), we investigated the current usage of tracheostomy in patients with ARDS recruited into the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) study. Methods: This is a secondary analysis of LUNG-SAFE, an international, multicenter, prospective cohort study of patients receiving invasive or noninvasive ventilation in 50 countries spanning 5 continents. The study was carried out over 4 weeks consecutively in the winter of 2014, and 459 ICUs participated. We evaluated the clinical characteristics, management and outcomes of patients that received tracheostomy, in the cohort of patients that developed ARDS on day 1-2 of acute hypoxemic respiratory failure, and in a subsequent propensity-matched cohort. Results: Of the 2377 patients with ARDS that fulfilled the inclusion criteria, 309 (13.0%) underwent tracheostomy during their ICU stay. Patients from high-income European countries (n = 198/1263) more frequently underwent tracheostomy compared to patients from non-European high-income countries (n = 63/649) or patients from middle-income countries (n = 48/465). Only 86/309 (27.8%) underwent tracheostomy on or before day 7, while the median timing of tracheostomy was 14 (Q1-Q3, 7-21) days after onset of ARDS. In the subsample matched by propensity score, ICU and hospital stay were longer in patients with tracheostomy. While patients with tracheostomy had the highest survival probability, there was no difference in 60-day or 90-day mortality in either the patient subgroup that survived for at least 5 days in ICU, or in the propensity-matched subsample. Conclusions: Most patients that receive tracheostomy do so after the first week of critical illness. Tracheostomy may prolong patient survival but does not reduce 60-day or 90-day mortality. Trial registration: ClinicalTrials.gov, NCT02010073. Registered on 12 December 2013

Temporal competition between differentiation programs determines cell fate choice

Multipotent differentiation, where cells adopt one of several possible fates, occurs in diverse systems ranging from bacteria to mammals. This decision-making process is driven by multiple differentiation programs that operate simultaneously in the cell. How these programs interact to govern cell fate choice is poorly understood. To investigate this issue, we simultaneously measured activities of the competing sporulation and competence programs in single Bacillus subtilis cells. This approach revealed that these competing differentiation programs progress independently without cross-regulation before the decision point. Cells seem to arrive at a fate choice through differences in the relative timing between the two programs. To test this proposed dynamic mechanism, we altered the relative timing by engineering artificial cross-regulation between the sporulation and competence circuits. Results suggest a simple model that does not require a checkpoint or intricate cross-regulation before cellular decision-making. Rather, cell fate choice appears to be the outcome of a 'molecular race' between differentiation programs that compete in time, providing a simple dynamic mechanism for decision-making