2,880 research outputs found
Digital holography-based 3D particle localization for single-molecule tweezer techniques
We present a three-dimensional (3D) imaging technique for the fast tracking of microscopic objects in a fluid environment. Our technique couples digital holographic microscopy with three-dimensional localization via parabolic masking. Compared with existing approaches, our method reconstructs 3D volumes from single-plane images, which greatly simplifies image acquisition, reduces the demand on microscope hardware, and facilitates tracking higher densities of microscopic particles while maintaining similar levels of precision. We demonstrate utility of this method in magnetic tweezer experiments, opening their use to multiplexed single-molecule force spectroscopy assays, which were previously limited by particle crowding and fast dissociation times. We propose that our technique will also be useful in other applications that involve the tracking of microscopic objects in three dimensions, such as studies of microorganism motility and 3D flow characterization of microfluidic devices
Social Media Fingerprints of Unemployment
Anexo: Supporting Information. This file contains Figures A-I, Tables A-F and Sections A-I.Recent widespread adoption of electronic and pervasive technologies has enabled the study of human behavior at an unprecedented level, uncovering universal patterns underlying human activity, mobility, and interpersonal communication. In the present work, we investigate whether deviations from these universal patterns may reveal information about the socio-economical status of geographical regions. We quantify the extent to which deviations in diurnal rhythm, mobility patterns, and communication styles across regions relate to their unemployment incidence. For this we examine a country-scale publicly articulated social media dataset, where we quantify individual behavioral features from over 19 million geo-located messages distributed among more than 340 different Spanish economic regions, inferred by computing communities of cohesive mobility fluxes. We find that regions exhibiting more diverse mobility fluxes, earlier diurnal rhythms, and more correct grammatical styles display lower unemployment rates. As a result, we provide a simple model able to produce accurate, easily interpretable reconstruction of regional unemployment incidence from their social-media digital fingerprints alone. Our results show that cost-effective economical indicators can be built based on publicly-available social media datasets.Partial funding came from the Spanish Ministry of Economy and Competitiveness through grant FIS2013-47532-C3-3-P, the Australian Government, and the Australian Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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Ethylene-mediated plant responses to severe water deficit in strawberry
The research described in this thesis focussed on the potential effect of ethylene
produced under severe water deficit conditions (SWD) on the concentration of phenolic
compounds in fruit and leaves of commercial strawberry (Fragaria x ananassa Duch.).
An increased ethylene production rate was detected in green fruit and leaves at
midday of the second day of wilting in response to SWD. The stress-induced rise in
ethylene production was successfully inhibited by applications of
aminoethoxyvinylglycine (AVG) and subsequently re-instated by 1-aminocyclopropane-
1-carboxylic acid (ACC) or replaced by abscisic acid (ABA) in fruits. Initially, fruit total
ellagic acid concentration increased along with ethylene production but conclusive
evidence for the causal role of ethylene in the accumulation of individual phenolics in
fruit from the inhibition, re-instatement and replacement of the ethylene signal was not
obtained. The quantitative expression of selected genes in leaves was investigated,
and a significant reduction in the relative expression of FaACS1 (coding for ACC
synthase), an increase in FaACO1, FaACO4 (coding for ACC oxidase) expression and
no change on the expression FaPAL (coding for Phenylalanine ammonia lyase) was
observed. Increased leaf ethylene production rate was likely due to increased
expression of genes regulating ACC oxidase activity. However, no evidence was found
from these genetic studies to confirm the role of stress-induced ethylene production in
accumulation of phenolics in fruit or leaves
Optimizing diffusion, morphology and minority carrier lifetime in silicon for GaAsP/Si dual-junction solar cells
Dual-junction solar cells formed by a GaAsP cell on a silicon bottom cell seem to be attractive candidates to materialize the long sought-for integration of III-V materials on Si for photovoltaic applications. In this study, we analyze several factors for the optimization of the bottom cell, namely, 1) the emitter formation as a result of phosphorus diffusion; 2) the growth of a high quality GaP nucleation layer; and 3) the process impact on the bottom subcell PV properties
3D hp-Adaptive Finite Element Simulations of Bend, Step, and Magic-T Electromagnetic Waveguide Structures
Metallic rectangular waveguides are often the preferred choice on telecommunication systems and medical equipment working on the upper microwave and millimeter wave frequency bands due to the simplicity of its geometry, low losses, and the capacity to handle high powers. Waveguide translational symmetry is interrupted by the unavoidable presence of bends, transitions, and junctions, among others. This paper employs a 3D hp self-adaptive grid-refinement finite element strategy for the solution of these relevant electromagnetic waveguide problems. These structures often incorporate dielectrics, metallic screws, round corners, and so on, which may facilitate its construction or improve its design, but significantly difficult its modeling when employing semi-analytical techniques. The hp-adaptive finite element method enables accurate modeling of these structures even in the presence of complex materials and geometries. Numerical results demonstrate the suitability of the hp-adaptive method for modeling these waveguide structures, delivering errors below 0.5% with a limited number of unknowns. Solutions of waveguide problems obtained with the self-adaptive hp-FEM are of comparable accuracy to those obtained with semi-analytical techniques such as the Mode Matching method, for problems where the latest methods can be applied. At the same time, the hp-adaptive FEM enables accurate modeling of more complex waveguide structures.TEC2010-18175/TCM
MTM2010-1651
Barriers and Facilitators for Exclusive Breastfeeding within the Health System and Public Policies from In-Depth Interviews to Primary Care Midwives in Tenerife (Canary Islands, Spain)
The aim of this study is to describe the perspectives of Primary Care midwives regarding factors that benefit or are detrimental to exclusive breastfeeding (EBF) within the health system and public policies. The study was carried out in Tenerife (Canary Islands, Spain) and is based on qualitative methodology. Twenty in-depth interviews were carried out with midwives who work in Primary Care centres in Tenerife, using a content analysis approach. The transcript data were then encoded following an inductive approach. The factors, according to midwives, that affect EBF, with regard to the healthcare system, are related to training of healthcare professionals in breastfeeding and their support to women during pregnancy, childbirth and postnatal care. Regarding public policies, midwives believe the maternity leave periods in Spain, together with a lack of laws and social policies to protect EBF are detrimental. The findings from our study show that there is a need to boost training and the role of professionals in EBF and, at the same time, promote protective policies that foster equality, favouring, among other issues, the work-life balance.This research was funded by the Spanish Health Research Fund (PIFIISC 19/15). Canary Islands Foundation Health Research Institute of the Canary Islands (FIISC). CIF: G76208396 Barranco de la Ballena, s/n Edificio Anexo al Hospital Universitario de Gran Canaria “NegrĂn” 35019—Las Palmas de Gran Canaria, Canary Island, Spain.S
Patient No-Show Prediction: A Systematic Literature Review
Nowadays, across the most important problems faced by health centers are those caused by
the existence of patients who do not attend their appointments. Among others, these patients
cause loss of revenue to the health centers and increase the patients’ waiting list. In order to
tackle these problems, several scheduling systems have been developed. Many of them require
predicting whether a patient will show up for an appointment. However, obtaining these estimates accurately is currently a challenging problem. In this work, a systematic review of the literature on predicting patient no-shows is conducted aiming at establishing the current state-of-the-art. Based on a systematic review following the PRISMA methodology, 50 articles were found and analyzed.
Of these articles, 82% were published in the last 10 years and the most used technique was logistic regression. In addition, there is significant growth in the size of the databases used to build the classifiers. An important finding is that only two studies achieved an accuracy higher than the show rate. Moreover, a single study attained an area under the curve greater than the 0.9 value. These facts indicate the difficulty of this problem and the need for further research
Effects of leaf wetness duration and temperature on infection of Prunus by Xanthomonas arboricola pv. pruni
Xanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits and almond. The bacterium is distributed throughout the major stone-fruit-producing areas of the World and is considered a quarantine organism in the European Union according to the Council Directive 2000/29/EC, and by the European and Mediterranean Plant Protection Organization. The effect of leaf wetness duration and temperature on infection of Prunus by X. arboricola pv. pruni was determined in controlled environment experiments. Potted plants of the peach-almond hybrid GF-677 were inoculated with bacterial suspensions and exposed to combinations of six leaf wetness durations (from 0 to 24 h) and seven fixed temperatures (from 5 to 35°C) during the infection period. Then, plants were transferred to a biosafety greenhouse, removed from bags, and incubated at optimal conditions for disease development. Although leaf wetness was required for infection of Prunus by X. arboricola pv. pruni, temperature had a greater effect than leaf wetness duration on disease severity. The combined effect of wetness duration and temperature on disease severity was quantified using a modification of the Weibull equation proposed by Duthie. The reduced-form of Duthie's model obtained by nonlinear regression analysis fitted well to data (R = 0.87 and R2adj = 0.85), and all parameters were significantly different from 0. The estimated optimal temperature for infection by X. arboricola pv. pruni was 28.9°C. Wetness periods longer than 10 h at temperatures close to 20°C, or 5 h at temperatures between 25 and 35°C were necessary to cause high disease severity. The predictive capacity of the model was evaluated using an additional set of data obtained from new wetness duration-temperature combinations. In 92% of the events the observed severity agreed with the predicted level of infection risk. The risk chart derived from the reduced form of Duthie's model can be used to estimate the potential risk for infection of Prunus by X. arboricola pv. pruni based on observed or forecasted temperature and wetness durationMinisterio de Educación, Ciencia y Deporte (AGL2013-41405-R, FPU13/04123) of
Spain (https://www.mecd.gob.es/). University of Girona (SING12/13, MPCUdG2016/085) (www.
udg.edu). European Union’s Seventh Framework Programme for research, technological
development and demonstration under grant agreement number 613678 (DROPSA
Basis for a predictive model of Xanthomonas arboricola pv pruni growth and infections in host plants
Xanthomonas arboricola pv. pruni (Xap) is the causal agent of bacterial spot disease of stone fruits and almond. The bacterium is considered a quarantine pathogen in Europe and it has become a new and emerging threat for European crops. As the disease is strongly influenced by the weather, a forecasting model that predicts Xap infections based on climatic conditions could be implemented in stone fruit integrated pest management. The objective of this work was to constrain the basis for the development of a predictive model of Xap growth and infections, determining the effects of pathogen, host and climatic parameters on infection and disease development. A non-pathogenic specialization of Xap and cross-infection among host species was observed, although strains isolated from peach were the most virulent in peach leaves. Xap was able to infect unwounded leaves and it was observed that the presence of wounds on the leave surface did not favour Xap penetration in peach leaves. Otherwise, the water condition of plants played an important role in Xap infections and disease development in peach. The presence of water congestion and leaf wetness 48 h before inoculation favoured Xap infections and the duration of leaf wetness after inoculation was directly correlated to disease severity. Temperature and leaf age had a significant effect on Xap infections. Temperatures above 20°C favoured Xap infections, which were basically produced in young leaves; whereas severity was significantly lower at temperatures below 15°C and in mature leavesSupported by research grants BR 2013/31 from University of Girona and
FPU13/04123 from Spain MECD, and the projects AGL2013-41405-R from Spain MINECO and the European Union Seventh Framework (FP7 / 2007-2013) under the agreement n°613678 (DROPSA
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