1,725 research outputs found
Observability analysis and optimal sensor placement in stereo radar odometry
© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Localization is the key perceptual process closing the loop of autonomous navigation, allowing self-driving vehicles to operate in a deliberate way. To ensure robust localization, autonomous vehicles have to implement redundant estimation processes, ideally independent in terms of the underlying physics behind sensing principles. This paper presents a stereo radar odometry system, which can be used as such a redundant system, complementary to other odometry estimation processes, providing robustness for long-term operability. The presented work is novel with respect to previously published methods in that it contains: (i) a detailed formulation of the Doppler error and its associated uncertainty; (ii) an observability analysis that gives the minimal conditions to infer a 2D twist from radar readings; and (iii) a numerical analysis for optimal vehicle sensor placement. Experimental results are also detailed that validate the theoretical insights.Peer ReviewedPostprint (author's final draft
Desarrollo, investigación y agricultura en Costa Rica
En el artículo se resume la evolución y la interacción de los procesos de desarrollo e investigación agropecuaria en Costa Rica. Se describe los principales modelos de desarrollo utilizados, así como los factores que determinan el mismo, empleando una definición economisista del término, y mencionando las principales actividades agrícolas que se vieron afectadas en su momento por la aplicación de dichos modelos. El desarrollo de la investigación sigue también un proceso histórico evolutivo, de manera que se presenta los principales cambios producidos en el tiempo en los componentes más importantes que lo determinan. Una tercera sección incluye algunas reflexiones del por qué no hay relación entre los modelos de desarrollo y los principales logros de investigación, demostrándose que, a pesar de que la investigación tiene un costo, esta paga con creces su valor
Why are people afraid of the dentist?
Introducción: el objetivo del presente artículo es describir la actitud de los pacientes en relación a diferentes factores subyacentes a los miedos dentales. Método: se realiza una en- cuesta con una muestra de 399 sujetos que acudieron a la consulta de Odontología del Centro de Salud de Lepe (Huelva). Se utilizó un cuestionario con 19 ítemes. El tratamiento estadístico se desarrolló con el paquete de programas SPSS, versión 9.0 (SPSS Inc., Chicago, Ill, 1999). Re- sultados: al analizar la estructura factorial de la escala de miedos dentales se encontraron cua- tro factores resultantes que se corresponderían con otras tantas dimensiones presentes. El prin- cipal temor de los pacientes se centra en las actuaciones terapéuticas que generan o posibili- tan daño físico, mientras que los aspectos no relacionados con la profesión les generan menos miedo. Conclusiones: en los miedos al dentista, se identifican cuatro dimensiones o aspectos que podrían diferenciarse y que constituirían respuestas a la pregunta ¿por qué se le tiene mie- do al dentista? Dos de estas dimensiones generan un bajo grado de temor, son las denomina- das como aspectos no profesionales y aspectos inherentes al tratamiento. Sin embargo, las otras dos dimensiones sí provocan temor en cierta medida y son las llamadas trato humano, y mala praxis profesionalIntroduction: the aim of the current article is to describe the patient’s attitude regar- ding several factors hidden in dental fears. Patients and methods: An survey has been performed among 399 patients who visited the Dental department of the Public Health Center localized in Lepe (Huelva, Spain). The questionnaire used included 19 items. The statistical data processing was carried out with the help of the specific software SPSS, version 9.0 (SPSS Inc., Chicago, Ill, 1999). Results: Analysing the factorial composition of dental fears scale, we detected four fac- tors. The main factor is related to therapeutic actions that may cause physical damage, while fac- tors not related to the professional field generate less fear. Conclusion: among dental fears, it has been possible to differentiate four aspects or dimensions that could represent answers to the question about why people are afraid of the dentist. Two of these dimensions, which generate a low level fear, are the so-called non-professional aspects and treatment inherent aspects. Ho- wever, the other two dimensions do provoke a certain degree of fear and consist in factors re- lated to the treatment received at a personal level and professional malpractice
Ecotoxicological risks of the abandoned F-Ba-Pb-Zn mining area of Osor (Spain)
This is a copy of the author 's final draft version of an article published in the journal Environmental geochemistry and health.
The final publication is available at Springer via
http://dx.doi.org/10.1007/s10653-016-9840-2Due to its potential toxic properties, metal mobilization is of major concern in areas surrounding Pb-Zn mines. In the present study, metal contents and toxicity of soils, water extracts from soils, and mine drainage waters from an abandoned F-Ba-Pb-Zn mining area in Osor (Girona, NE Spain) were evaluated through chemical extractions and ecotoxicity bioassays. Toxicity assessment in the terrestrial compartment included lethal and sublethal endpoints on earthworms Eisenia foetida, arthropods Folsomia candida and several plant species whereas aquatic tests involved bacteria Vibrio fischeri, microalgae Raphidocelis subcapitata and crustaceans Daphnia magna. Metal quantifications revealed high concentrations of Ba (250-5110 mg kg-1), Pb (940->5000 mg kg-1) and Zn (2370-11300 mg kg-1) that exceeded intervention values to protect human health. Risks for the aquatic compartment were identified through the release of drainage waters and by leaching and run-offs from metal-contaminated soils. Cd (1.98-9.15 µg L-1), Pb (2.11-326 µg L-1) and Zn (280-2900 µg L-1) in water samples surpassed international values of aquatic life criteria. Terrestrial ecotoxicity tests were in accordance with metal quantifications and identified the most polluted soil as the most toxic. Avoidance and reproduction tests with earthworms showed the highest sensitivity to metal contamination. Aquatic bioassays with extracts from soils confirmed the results from terrestrial tests and detected severe toxic effects caused by the mine drainage waters. Algal growth inhibition was the most sensitive aquatic endpoint. In view of the results, the application of a containment or remediative procedure in the area is encouraged.Peer ReviewedPostprint (author's final draft
Effect of biochar amendment on morphology, productivity and water relations of sunflower plants under non-irrigation conditions
páginas.-- 6 figuras.-- 2 tablas.-- 56 referencias.-- Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.catena.2016.07.037.Three biochars (B1: pine wood, B2: paper-sludge, B3: sewage-sludge) produced under controlled pyrolysis conditions and one produced in kilns (B4: grapevine wood) were used as organic ameliorants in a Calcic Cambisol, which represents a typical agricultural soil of the Mediterranean region. This field study was performed with plants of sunflower (Helianthus annuus L.) at the experimental station “La Hampa”, located in the Guadalquivir river valley (SW Spain). The soil was amended with doses equivalent to 1.5 and 15 t ha− 1 of the four biochars in two independent plantations. In addition, un-amended plots were prepared in both experiments for comparison purposes. The major goal of this study was the assessment of the effect of biochar amendment on the physiology and development of sunflower plants at field conditions. During most of the growing period plants of un-amended and amended plots showed no stress symptoms either by their appearance or by stress-sensitive biochemical parameters such as the stability of the photosystem II (QY). Biochar addition had no effect on seed germination. Addition of 1.5 t ha− 1 biochar did not significantly change the pH of the soil, its electrical conductivity (EC) or its water holding capacity (WHC). Concomitantly the plant development and plant biomass production remained unaltered. Amendments with 15 t ha− 1 slightly increased the WHC of the soil but showed no lasting impact on the soil pH. It stimulated plant growth and led to a greater leaf area, larger plant stems and wider inflorescences of the sunflower plants than those cultivated on the un-amended soil. At the end of the experiment, biochar amendment of soil caused no significant increase of the total biomass production excepting B4, the biochar with the lowest capacity of water retention, which exhibited the highest vegetative growth and seed production. The lack of rain during the last weeks caused a water shortage in the culture that produced greater QY loss in non-amended plants. Interestingly, better growth of amended plants during the drought period correlated with higher reduction of stomatal conductance, indicating that the greater water use efficiency is at the origin of the better crop performance of biochar-amended plants. This finding points to the agronomic relevance of biochar amendment of Mediterranean rain fed crops.The Marie Skłodowska-Curie actions of the European Union's FP7 People Programme (REA grant agreement no PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The Spanish Ministry of Education, Culture and Sport is acknowledged for funding the FPU fellowship (FPU 13/05831) of Marina Paneque, and the contract of Juan De Dios Franco-Navarro (AGL2009-08339/AGR). The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples. M. Velasco is gratefully acknowledged for her technical assistance at field.Peer reviewe
Diversidad de sistemas de cultivo y transición agroecológica: estudio de caso en la Sierra Norte del estado de Puebla, México
Objective. To contribute to characterize the diversity and functioning of croppingsystems of four communities in the Northern Sierra of the state of Puebla, Mexico, topropose actions through sociotechnical practices in order to contribute towards anagroecological transition and territorial sustainability.Design and methodology. Surveys were applied to key informants in four communities,afterwards a stratified random sampling (SRS) was used to apply a questioner to 76family systems and their main plot. R program ver. 3.5.2. was used to test normality,basic statistics, ANOVA and HSD Tukey.Results. Family systems have 2.21 ha for farming, main plot is 0.74 ha on average. Sixcropping systems were identified, and they are practiced by families in different
2proportions: 1) maize, collecting weeds and fruits (Mmr), 47.37% of families; 2) coffeemonoculture (Uc), 15.79%; 3) split plot (Pd), 11.84%; 4) maize-bean intercrop withcollecting (Amfr), 10.53%; 5) fruits and annual crops intercrops (Afa), 9.21%; 6) Othercropping systems (Osc), 5.26%. There were identified eight crops and 16 collectingspecies. Pd system had statistical advantage related to production value.Limitation. Management strategies are explained at family farming system scale.Conclusions. Cropping systems show a diversity of farming management, and due totheir knowledge, local resources and socio technical practices evidence a favourablestate for the agroecological transition of the territorial agriculture.Objetivo. Contribuir a caracterizar la diversidad y funcionamiento de los sistemas decultivo de cuatro localidades de Sierra Norte del estado de Puebla, México, paraproponer acciones mediante prácticas sociotécnicas que contribuyan hacia unatransición agroecológica y la sustentabilidad territorial.Diseño y metodología. Entrevistas a personas clave en cuatro comunidades,posteriormente muestreo aleatorio estratificado (MAE) y selección de 76 sistemas defamiliares y su parcela principal, aplicación cuestionario. Utilización del programa Rversión 3.5.2 para pruebas de normalidad, determinación estadísticos básicos, análisisde correlación, ANOVA y HSD Tukey.Resultados. El sistema productivo familiar dispone de 2.21 ha de uso agrícola, la parcela principal en promedio 0.74 ha. Seis modalidades de sistemas de cultivo: 1) maíz con recolección de arvenses y frutas (Mmr) manejado por 47.37% de familias; 2) 3 unicultivo cafeto (Uc) el 15.79%; 3) parcela dividida (Pd) el 11.84%; 4) asociación maíz-frijol con recolección de otros satisfactores (Amfr) el 10.53%; 5) asociación frutales con cultivos anuales (Afa) el 9.21%; 6) otros sistemas de cultivo (Osc) 5.26% de familias. Seregistraron hasta: ocho especies agrícolas cultivadas y 16 especies de recolección. El sistema Pd muestra ventaja estadística significativa referente al valor de la producción.Limitante. Las lógicas de manejo se explican en escala sistema producción familiar.Conclusiones. Los sistemas de cultivo ilustran una diversidad de manejos culturales agrícolas, los cuales por sus saberes, recursos locales y prácticas sociotécnicas evidencian su estado favorable en el proceso de transición agroecológica de una agricultura territorial
Chloride regulates leaf cell size and water relations in tobacco plants
19 páginas.-- 9 figuras.-- 5 tablas.-- 77 referencias.-- Supplementary Data: Supplementary_figures_S1_S7___Tables_S1_S7.pdfChloride (Cl–) is a micronutrient that accumulates to macronutrient levels since it is normally available in nature and actively taken up by higher plants. Besides a role as an unspecific cell osmoticum, no clear biological roles have been explicitly associated with Cl– when accumulated to macronutrient concentrations. To address this question, the glycophyte tobacco (Nicotiana tabacum L. var. Habana) has been treated with a basal nutrient solution supplemented with one of three salt combinations containing the same cationic balance: Cl–-based (CL), nitrate-based (N), and sulphate+phosphate-based (SP) treatments. Under non-saline conditions (up to 5mM Cl–) and no water limitation, Cl– specifically stimulated higher leaf cell size and led to a moderate increase of plant fresh and dry biomass mainly due to higher shoot expansion. When applied in the 1–5mM range, Cl– played specific roles in regulating leaf osmotic potential and turgor, allowing plants to improve leaf water balance parameters. In addition, Cl– also altered water relations at the whole-plant level through reduction of plant transpiration. This was a consequence of a lower stomatal conductance, which resulted in lower water loss and greater photosynthetic and integrated water-use efficiency. In contrast to Cl–, these effects were not observed for essential anionic macronutrients such as nitrate, sulphate, and phosphate. We propose that the abundant uptake and accumulation of Cl– responds to adaptive functions improving water homeostasis in higher plants.This work was supported by the Spanish Ministry of Science and Innovation-FEDER grant AGL2009-08339/AGR. The help, expertise, and technical assistance of C. Rivero, A. Vázquez, S. Luque, B.J. Sañudo, F.J. Durán, Y. Pinto, and J. Espartero are gratefully acknowledged. We would like to extend our gratitude to the valuable reviews and contributions by the anonymous referees and the editor, Timothy Colmer, which helped us to improve the manuscript substantially.Peer reviewe
Effect of foot health-related quality of life in rural population: A case-control study
[Abstract] Background: Foot health problems can affect quality of life and general health producing a source of discomfort
and pain. Low levels of foot health-related quality of life (HRQoL) are present in patients with foot disabilities,
such as hallux valgus, plantar fasciitis, or minor toe deformities.
Objective: The objective was to analyze the foot health status in patients with and without foot problems in a rural
population and its relationship with quality of life.
Material and methods: A prospective case-control study was developed with a sample of 152 patients, 76 subjects
with podiatric pathologies and 76 without, in a rural population. HRQoL was measured through the SF-36 Health
Questionnaire in the Spanish version.
Results: The case group had a mean age of 49.18 ± 14.96 and the control group 44.16 ± 11.79. Regarding the
score of the lowest levels of quality of life related to foot problems, the case group compared to the controls
showed: for physical function (79.86 ± 26.38 vs. 92.63 ± 11 0.17, p < 0.001); for the physical role (73.68 ±
41.00 vs. 88.48 ± 27.51, p < 0.0022); for body pain (45.81 ± 27.18 vs. 73.68 ± 41.00, p < 0.035); and for
general health (60.36 ± 30.58 vs. 68.71 ± 18.52, p < 0.047). The differences between groups were analyzed
using the Mann-Whitney U test, which showed statistical significance (P < 0.05).
Conclusions: In the rural population, people with foot pathologies present a worse quality of life compared to
those who do not present foot pathology, especially for the health domains: physical function, physical role, body
pain and health general
Marketing and Exploitation of Sillar Añashuayco - Arequipa
The Sillar Route is located and developed in the ashlar quarries of Arequipa and is managed by the Ashlar Cutters Association. This research seeks to analyze the social determinants of the viability of sustainable tourism in the Cutters sector of the quarries of Arequipa. ashlar based on the opinion and perception of the quarry workers. The city of Arequipa was distinguished by UNESCO as a Cultural Heritage of Humanity in November 2000, in consideration of the buildings that make up the Cercado in its centuries-old neighborhoods, defined as a Monumental Zone and categorized as: religious monuments, military monuments, monuments civil-public and civil-domestic monuments. All of them share an element that, before the arrival of the conquerors, was already used in buildings built by Andean societies, ashlar. In this article we will see the main input of the buildings that have continued to be used for half a millennium, emerging as a fundamental element of the regional identity and the proposal to value the ashlar quarries, with a thematic tourist route that has been implemented
Trends in Prevalence of Diabetes among Twin Pregnancies and Perinatal Outcomes in Catalonia between 2006 and 2015 : the DIAGESTCAT Study
The aims of our study were to evaluate the trends in the prevalence of diabetes among twin pregnancies in Catalonia, Spain between 2006 and 2015, to assess the influence of diabetes on perinatal outcomes of twin gestations and to ascertain the interaction between twin pregnancies and glycaemic status. A population-based study was conducted using the Spanish Minimum Basic Data Set. Cases of gestational diabetes mellitus (GDM) and pre-existing diabetes were identified using ICD-9-CM codes. Data from 743,762 singleton and 15,956 twin deliveries between 2006 and 2015 in Catalonia was analysed. Among twin pregnancies, 1088 (6.82%) were diagnosed with GDM and 83 (0.52%) had pre-existing diabetes. The prevalence of GDM among twin pregnancies increased from 6.01% in 2006 to 8.48% in 2015 (p < 0.001) and the prevalence of pre-existing diabetes remained stable (from 0.46% to 0.27%, p = 0.416). The risk of pre-eclampsia was higher in pre-existing diabetes (15.66%, p = 0.015) and GDM (11.39%, p < 0.001) than in normoglycaemic twin pregnancies (7.55%). Pre-existing diabetes increased the risk of prematurity (69.62% vs. 51.84%, p = 0.002) and large-for-gestational-age (LGA) infants (20.9% vs. 11.6%, p = 0.001) in twin gestations. An attenuating effect on several adverse perinatal outcomes was found between twin pregnancies and the presence of GDM and pre-existing diabetes. As a result, unlike in singleton pregnancies, diabetes did not increase the risk of all perinatal outcomes in twins and the effect of pre-existing diabetes on pre-eclampsia and LGA appeared to be attenuated. In conclusion, prevalence of GDM among twin pregnancies increased over the study period. Diabetes was associated with a higher risk of pre-eclampsia, prematurity and LGA in twin gestations. However, the impact of both, pre-existing diabetes and GDM, on twin pregnancy outcomes was attenuated when compared with its impact on singleton gestations
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