29 research outputs found
Preliminary Study on the 3D Digitization of Millimeter Scale Products by Means of Photogrammetry
AbstractPhotogrammetry is a passive 3D digitization technique, mainly oriented to large sized objects, since its origins are in architectural and civil engineering. With the continuos development of digital imaging hardware and software, photogrammetric applications are involving smaller and smaller fields of view, with some critical aspects such as the depth of field getting narrower. In this conditions the lack of focus becomes important and affects heavily the possibility of accurately calibrate cameras. Bi-dimensional calibration patterns are affected by this problem when the camera principal axis has an angle with the pattern plane higher than a critical value. Moreover, the accuracy of the pattern, in terms of both shape and 3D positions of the targets, becomes critical decreasing the size of the pattern. In this paper the authors address these problems through a comparison of several calibration patterns included into the open source computer vision software library called OpenCV. 3D digitization of a small object is presented to test the best resulting calibration, using a consumer reflex camera equipped with macro lens and extension tube
Intensive Habitat Loss in South Spain: Arborescent Scrubs with <em>Ziziphus</em> (5220*)
The habitat arborescent matorral with Ziziphus (5220*) was included in the Habitats Directive of the European Commission. These plant formations represent the maximum potential vegetation in a very restrictive arid environment, since it encompasses endemic, tropical, or Maghrebian floristic elements, and from other areas of the ancient Thetis Sea. In fact, the version of this community with Gymnosporia senegalensis (Lam.) Loes. [=Maytenus senegalensis (Lam.) Exell] constitutes extraordinarily singular flora formations in the Iberian southeast. These are unique communities in Europe and ecologically extremely valuable and, however, have been included among the Europe’s most endangered habitats. The vast economic development experienced in South Spain based on the remarkable transformation of traditional farming patterns into a highly profitable agriculture that uses industrial production methods and the groundwater intensively (agriculture intensification and land-use change), in addition to urbanization without sustainable land planning, determines that European G. senegalensis populations are seriously threatened by severe habitat destruction and fragmentation
Sobre el grado de aceptación de la teoría evolutiva de los alumnos de Enseñanza Secundaria Obligatoria
La Teoría de la Evolución (TE) es una teoría unificadora en la Biología y su comprensión es fundamental para entender la naturaleza y nuestro lugar en ella. En este trabajo se ha evaluado si 137 alumnos de Enseñanza Secundaria Obligatoria (E.S.O.) en Almería aceptan la TE. Para esto se ha utilizado el cuestionario MATE y los datos han sido analizados mediante una prueba t de Student. De esta manera se pudo concluir que los alumnos de cursos superiores presentan un mayor grado de aceptación de la TE. Por otra parte, aquellos con una orientación científica tuvieron una aceptación muy alta si los comparamos con los que tenían una orientación de ciencias sociales cuya aceptación fue moderada. Los alumnos cuyo padre tiene una formación superior, mostraron también un mayor grado de aceptación de la TE, mientras que en el caso de la madre la diferencia no llegó a ser significativa
Photogrammetric measurement of 3D freeform millimetre-sized objects with micro features: an experimental validation of the close-range camera calibration model for narrow angles of view
The measurement of millimetre and micro-scale features is performed by high-cost systems
based on technologies with narrow working ranges to accurately control the position of the
sensors. Photogrammetry would lower the costs of 3D inspection of micro-features and
would be applicable to the inspection of non-removable micro parts of large objects too.
Unfortunately, the behaviour of photogrammetry is not known when photogrammetry is
applied to micro-features.
In this paper, the authors address these issues towards the application of digital closerange
photogrammetry (DCRP) to the micro-scale, taking into account that in literature there
are research papers stating that an angle of view (AOV) around 10° is the lower limit to the
application of the traditional pinhole close-range calibration model (CRCM), which is the basis
of DCRP.
At first a general calibration procedure is introduced, with the aid of an open-source
software library, to calibrate narrow AOV cameras with the CRCM. Subsequently the
procedure is validated using a reflex camera with a 60mm macro lens, equipped with
extension tubes (20 and 32mm) achieving magnification of up to 2 times approximately, to
verify literature findings with experimental photogrammetric 3D measurements of millimetresized
objects with micro-features. The limitation experienced by the laser printing technology,
used to produce the bi-dimensional pattern on common paper, has been overcome using an
accurate pattern manufactured with a photolithographic process.
The results of the experimental activity prove that the CRCM is valid for AOVs down to
3.4° and that DCRP results are comparable with the results of existing and more expensive
commercial techniques.Percoco, G.; Sánchez Salmerón, AJ. (2015). Photogrammetric measurement of 3D freeform millimetre-sized objects with micro features: an experimental validation of the close-range camera calibration model for narrow angles of view. Measurement Science and Technology. 26(9):1-9. doi:10.1088/0957-0233/26/9/095203S19269Mitchell, H. L., Kniest, H. T., & Won‐Jin, O. (1999). Digital Photogrammetry and Microscope Photographs. The Photogrammetric Record, 16(94), 695-704. doi:10.1111/0031-868x.00148Chen, Z., Liao, H., & Zhang, X. (2014). Telecentric stereo micro-vision system: Calibration method and experiments. Optics and Lasers in Engineering, 57, 82-92. doi:10.1016/j.optlaseng.2014.01.021Stamatopoulos, C., & Fraser, C. S. (2011). Calibration of long focal length cameras in close range photogrammetry. The Photogrammetric Record, 26(135), 339-360. doi:10.1111/j.1477-9730.2011.00648.xYang, X., & Fang, S. (2014). Effect of field of view on the accuracy of camera calibration. Optik, 125(2), 844-849. doi:10.1016/j.ijleo.2013.07.089Strobl, K. H., Sepp, W., & Hirzinger, G. (2009). On the issue of camera calibration with narrow angular field of view. 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems. doi:10.1109/iros.2009.5354776Ricolfe-Viala, C., & Sanchez-Salmeron, A.-J. (2010). Lens distortion models evaluation. Applied Optics, 49(30), 5914. doi:10.1364/ao.49.005914Ricolfe-Viala, C., Sanchez-Salmeron, A.-J., & Valera, A. (2013). Efficient Lens Distortion Correction for Decoupling in Calibration of Wide Angle Lens Cameras. IEEE Sensors Journal, 13(2), 854-863. doi:10.1109/jsen.2012.2229704Zhang, Z. (2000). A flexible new technique for camera calibration. IEEE Transactions on Pattern Analysis and Machine Intelligence, 22(11), 1330-1334. doi:10.1109/34.888718Percoco, G., Lavecchia, F., & Salmerón, A. J. S. (2015). Preliminary Study on the 3D Digitization of Millimeter Scale Products by Means of Photogrammetry. Procedia CIRP, 33, 257-262. doi:10.1016/j.procir.2015.06.046Ricolfe-Viala, C., & Sanchez-Salmeron, A.-J. (2011). Camera calibration under optimal conditions. Optics Express, 19(11), 10769. doi:10.1364/oe.19.010769Guidi, G. (2013). Metrological characterization of 3D imaging devices. Videometrics, Range Imaging, and Applications XII; and Automated Visual Inspection. doi:10.1117/12.2021037Herráez, J., Martínez-Llario, J., Coll, E., Rodríguez, J., & Martin, M. T. (2013). Design and calibration of a 3D modeling system by videogrammetry. Measurement Science and Technology, 24(3), 035001. doi:10.1088/0957-0233/24/3/03500
Fold and fault activity in the Campo de Dalias from GNSS networks
IV Reunión Ibérica sobre Fallas Activas y Paleosismología, del 7 al 10 de septiembre de 2022 en Teruel.-- 3 pages, 1 figure, 1 table[EN] The Campo de Dalias GNSS network monitors since 2006 the active tectonic deformation of the most seismic area on the boundary of the Alboran Sea and the Betic Cordillera. The residual deformation rates determined with respect to Eurasia range from 1.7 to 3.0 mm/yr. The displacements are roughly homogenous towards WSW of the northern sites while the southern sites evidence irregular displacements towards the W and NW. This deformation pattern supports simultaneous NNWSSE shortening that develops ENE-WSW folds and ENE-WSW extension, accommodated by normal and oblique faults. Moreover, the GNSS results point to dextral kinematics of the main NW-SE Balanegra Fault, that was previously considered as a normal fault. These GNSS results thus reveal, for the first time, present-day interaction of the roll-back tectonics of the Rif-Gibraltar-Betics slab in the western part of the Gibraltar Arc with the indentation tectonics affecting the eastern and southern areas, providing new insights for seismic hazard studies in this region[ES] La red GNSS del Campo de Dalias monitoriza desde 2006 la deformación tectónica activa de la zona con mayor sismicidad del límite entre la Cordillera Bética y el Mar de Alborán. Las velocidades de deformación residuales calculadas con respecto a Eurasia oscilan entre 1,7 y 3,0 mm/año. Los desplazamientos son aproximadamente homogéneos hacia el OSO de las estaciones del norte, mientras que las estaciones del sur evidencian desplazamientos irregulares hacia el O y el NO. Este patrón de deformación indica el acortamiento NNO-SSE que desarrolla pliegues ENE-OSO simultáneo a la extensión ENEOSO, acomodada por fallas normales y oblicuas. Además, los resultados de la red GNSS indican un salto dextro de la falla de Balanegra, con orientación NO-SE, que había sido considerada anteriormente como una falla normal. Las redes GNSS revelan, por primera vez, la interacción actual de la tectónica de roll-back asociada a la subducción Rif-Gibraltar-Bética en la parte occidental del Arco de Gibraltar y la tectónica de indentación que afecta a las zonas oriental y meridional del Mar de Alborán. Además, proporciona nuevos datos para los estudios de peligrosidad sísmica en esta regiónJunta de Andalucía; FEDER: AGORA P18-RT-3275, PAPEL B-RNM-301-UGR18; Programa Operativo FEDER-Andalucía 2014–2020 1263446; Universidad de Jaén. CEACTEMA. POAIUJA 21/22, Junta de Andalucía. RNM-148, RNM-282, RNM-370; V.T.S. FPU (16/04038)Peer reviewe
Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure
A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants
© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)
From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions
Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants
Background
Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories.
Methods
We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age.
Findings
The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran.
Interpretation
Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings