Demonstration of low differential phase noise for optical phased arrays with optical amplification

Optical phased arrays (OPAs) are key enablers for light detection and ranging (LiDAR) in autonomous vehicles, free space optical communications, imaging and coherent beam combining. Active OPAs (with amplitude and phase control) allow the control of individual channel gains along with phases for enhanced control of far-field beam pattern. Path length variations and noise from amplifiers degrade the differential phase noise between the OPA channels, which is a key performance indicator that determines the far-field performance in terms of power in the main lobe, extinction of side lobes and pointing error. Conventionally, in fiber-based platforms, multiple phase locked loops are required to reduce the differential phase noise by locking the channels.In this work, we investigate the differential phase noise in an InP active OPA and demonstrate less than 10 mrad differential phase noise corresponding to a stability better than λ/600. To the best of our knowledge, this is the first demonstration of low differential phase noise in an active OPA with amplification in a photonic integrated platform. This result enables on-chip OPA amplification in the InP platform without active locking, thus reducing the system complexity and power consumption

Integrated optical phased array with on-chip amplification enabling programmable beam shaping

We present an integrated optical phased array (OPA) which embeds in-line optical amplifiers and phase modulators to provide beam-forming capability with gain and beam steering in the 1465–1590 nm wavelength range. We demonstrate up to 21.5 dB net on-chip gain and up to 35.5 mW optical output power. The OPA circuit is based on an InP photonic integration platform and features the highest measured on-chip gain and output power level recorded in an active OPA (i.e., with amplification), to the best of our knowledge. Furthermore, the OPA enables the independent control of both amplitude and phase in its arms and through this we demonstrate programmable beam shaping for two cases. First, we carried out a Gaussian apodization of the power distribution profile in the OPA emitter waveguides, leading to 19.8 dB sidelobe suppression in the far-field beam, which is the highest value recorded for active OPAs, and then we demonstrated beam forming of 0th, 1st, and 2nd order 1D Hermite–Gaussian beams in free-space

Solución al problema del despacho de energía en sistemas hidrotérmicos usando simulated annealing

Este artículo describe el problema de Despacho Hidrotérmico (DHT) en Sistemas Eléctricos de Potencia. El modelo matemático que lo describe, es linealizado y para su solución se emplea Programación Lineal (PL) apoyada de una metodología de optimización combinatorial denominada Simulated Annealing (SA). Un sistema eléctrico compuesto por tres unidades hidráulicas y dos plantas térmicas es usado para llevar a cabo la implementación de la metodología propuesta. Los resultados obtenidos con SA son comparados con los obtenidos por Branch and Bound (ByB), una técnica clásica y eficiente de la Programación Entera Mixta (PEM). El algoritmo de SA encuentra respuestas de excelente calidad, mostrando el gran potencial del método de solución a este tipo de problemas

Síndrome de «burnout» y apoyo social en maestros de Educación Primaria

This paper examines the relationship between burnout and perceived social support in a sample of 801 Primary School teachers. The Maslach Burnout Inventory (MBI) and the Duke-UNC-11 questionnaire were used. The statistical method used was canonical correspondence analysis, where the linear combination of the social support factors that maximises the dispersion of values of the three dimensions of the MBI was selected. The results of the study show that perceived social support relates to each of the dimensions of burnout syndrome in a different way and that is key to restore psychosocial balance.Este trabajo examina la relación entre burnout y apoyo social percibido en una muestra de 801 maestros de Educación Primaria. Para ello se usa el Maslach Burnout Inventory (MBI) y el cuestionario Duke-UNC-11. El método estadístico empleado fue el análisis canónico de correspondencias, donde se seleccionó la combinación lineal de los factores del apoyo social que maximiza la dispersión de valores de las tres dimensiones del MBI. Los resultados muestran que un 20,8% de los maestros sufre burnout. El apoyo social percibido, en su carácter restaurador del equilibrio psicosocial, se relaciona de distinto modo con las tres dimensiones del burnout.</em

An integrated hypothesis on the domestication of Bactris gasipaes

Data Availability Statement: All relevant data are within the paper and its Supporting Information files.Peach palm (Bactris gasipaes Kunth) has had a central place in the livelihoods of people in the Americas since pre-Columbian times, notably for its edible fruits and multi-purpose wood. The botanical taxon includes both domesticated and wild varieties. Domesticated var gasipaes is believed to derive from one or more of the three wild types of var. chichagui identified today, although the exact dynamics and location of the domestication are still uncertain. Drawing on a combination of molecular and phenotypic diversity data, modeling of past climate suitability and existing literature, we present an integrated hypothesis about peach palm’s domestication. We support a single initial domestication event in south western Amazonia, giving rise to var. chichagui type 3, the putative incipient domesticate. We argue that subsequent dispersal by humans across western Amazonia, and possibly into Central America allowed for secondary domestication events through hybridization with resident wild populations, and differential human selection pressures, resulting in the diversity of present-day landraces. The high phenotypic diversity in the Ecuadorian and northern Peruvian Amazon suggest that human selection of different traits was particularly intense there. While acknowledging the need for further data collection, we believe that our results contribute new insights and tools to understand domestication and dispersal patterns of this important native staple, as well as to plan for its conservatio

Healthcare providers' adherence to breast cancer guidelines in Europe : a systematic literature review

Clinical guidelines' (CGs) adherence supports high-quality care. However, healthcare providers do not always comply with CGs recommendations. This systematic literature review aims to assess the extent of healthcare providers' adherence to breast cancer CGs in Europe and to identify the factors that impact on healthcare providers' adherence. We searched for systematic reviews and quantitative or qualitative primary studies in MEDLINE and Embase up to May 2019. The eligibility assessment, data extraction, and risk of bias assessment were conducted by one author and cross-checked by a second author. We conducted a narrative synthesis attending to the modality of the healthcare process, methods to measure adherence, the scope of the CGs, and population characteristics. Out of 8137 references, we included 41 primary studies conducted in eight European countries. Most followed a retrospective cohort design (19/41; 46%) and were at low or moderate risk of bias. Adherence for overall breast cancer care process (from diagnosis to follow-up) ranged from 54 to 69%; for overall treatment process [including surgery, chemotherapy (CT), endocrine therapy (ET), and radiotherapy (RT)] the median adherence was 57.5% (interquartile range (IQR) 38.8-67.3%), while for systemic therapy (CT and ET) it was 76% (IQR 68-77%). The median adherence for the processes assessed individually was higher, ranging from 74% (IQR 10-80%), for the follow-up, to 90% (IQR 87-92.5%) for ET. Internal factors that potentially impact on healthcare providers' adherence were their perceptions, preferences, lack of knowledge, or intentional decisions. A substantial proportion of breast cancer patients are not receiving CGs-recommended care. Healthcare providers' adherence to breast cancer CGs in Europe has room for improvement in almost all care processes. CGs development and implementation processes should address the main factors that influence healthcare providers' adherence, especially patient-related ones. Registration:: PROSPERO (CRD42018092884)

Adherence to breast cancer guidelines is associated with better survival outcomes : A systematic review and meta-analysis of observational studies in EU countries

Breast cancer (BC) clinical guidelines offer evidence-based recommendations to improve quality of healthcare for patients with or at risk of BC. Suboptimal adherence to recommendations has the potential to negatively affect population health. However, no study has systematically reviewed the impact of BC guideline adherence -as prognosis factor- on BC healthcare processes and health outcomes. The objectives are to analyse the impact of guideline adherence on health outcomes and on healthcare costs. We searched systematic reviews and primary studies in MEDLINE and Embase, conducted in European Union (EU) countries (inception to May 2019). Eligibility assessment, data extraction, and risk of bias assessment were conducted by one author and crosschecked by a second. We used random-effects meta-analyses to examine the impact of guideline adherence on overall survival and disease-free survival, and assessed certainty of evidence using GRADE. We included 21 primary studies. Most were published during the last decade (90%), followed a retrospective cohort design (86%), focused on treatment guideline adherence (95%), and were at low (80%) or moderate (20%) risk of bias. Nineteen studies (95%) examined the impact of guideline adherence on health outcomes, while two (10%) on healthcare cost. Adherence to guidelines was associated with increased overall survival (HR = 0.67, 95%CI 0.59-0.76) and disease-free survival (HR = 0.35, 95%CI 0.15-0.82), representing 138 more survivors (96 more to 178 more) and 336 patients free of recurrence (73 more to 491 more) for every 1000 women receiving adherent CG treatment compared to those receiving non-adherent treatment at 5 years follow-up (moderate certainty). Adherence to treatment guidelines was associated with higher costs, but adherence to follow-up guidelines was associated with lower costs (low certainty). Our review of EU studies suggests that there is moderate certainty that adherence to BC guidelines is associated with an improved survival. BC guidelines should be rigorously implemented in the clinical setting. Trial registration: PROSPERO (CRD42018092884)

New approaches to measuring anthelminthic drug efficacy: parasitological responses of childhood schistosome infections to treatment with praziquantel

By 2020, the global health community aims to control and eliminate human helminthiases, including schistosomiasis in selected African countries, principally by preventive chemotherapy (PCT) through mass drug administration (MDA) of anthelminthics. Quantitative monitoring of anthelminthic responses is crucial for promptly detecting changes in efficacy, potentially indicative of emerging drug resistance. Statistical models offer a powerful means to delineate and compare efficacy among individuals, among groups of individuals and among populations.; We illustrate a variety of statistical frameworks that offer different levels of inference by analysing data from nine previous studies on egg counts collected from African children before and after administration of praziquantel.; We quantify responses to praziquantel as egg reduction rates (ERRs), using different frameworks to estimate ERRs among population strata, as average responses, and within strata, as individual responses. We compare our model-based average ERRs to corresponding model-free estimates, using as reference the World Health Organization (WHO) 90 % threshold of optimal efficacy. We estimate distributions of individual responses and summarize the variation among these responses as the fraction of ERRs falling below the WHO threshold.; Generic models for evaluating responses to anthelminthics deepen our understanding of variation among populations, sub-populations and individuals. We discuss the future application of statistical modelling approaches for monitoring and evaluation of PCT programmes targeting human helminthiases in the context of the WHO 2020 control and elimination goals