A Linear Active Disturbance Rejection Control for a Ball and Rigid Triangle System

This paper proposes an application of linear flatness control along with active disturbance rejection control (ADRC) for the local stabilization and trajectory tracking problems in the underactuated ball and rigid triangle system. To this end, an observer-based linear controller of the ADRC type is designed based on the flat tangent linearization of the system around its corresponding unstable equilibrium rest position. It was accomplished through two decoupled linear extended observers and a single linear output feedback controller, with disturbance cancelation features. The controller guarantees locally exponentially asymptotic stability for the stabilization problem and practical local stability in the solution of the tracking error. An advantage of combining the flatness and the ADRC methods is that it possible to perform online estimates and cancels the undesirable effects of the higher-order nonlinearities discarded by the linearization approximation. Simulation indicates that the proposed controller behaves remarkably well, having an acceptable domain of attraction

Analysis of ecosystem services provision in the Colombian Amazon using participatory research and mapping techniques

Over the last two decades indigenous peoples in the lower Caquetá River basin in Colombia have experienced detrimental changes in the provision of important ecosystem services in ways that have significant implications for the maintenance of their traditional livelihoods. To assess these changes we conducted eight participatory mapping activities and convened 22 focus group discussions. We focused the analysis on two types of change: (1) changes in the location of ecosystem services provisioning areas and (2) changes in the stock of ecosystem services. The focal ecosystem services include services such as provision of food, raw materials and medicinal resources. Results from the study show that in the past two decades the demand for food and raw materials has intensified and, as a result, locations of provisioning areas and the stocks of ecosystem services have changed. We found anecdotal evidence that these changes correlate well with socio-economic factors such as greater need for income generation, change in livelihood practices and consumption patterns. We discuss the use of participatory mapping techniques in the context of marginalized and data-poor regions. We also show how this kind of information can strengthen existing ecosystem-based management strategies used by indigenous peoples in the Colombian Amazon

Extraction of antioxidant phenolic compounds by autohydrolysis of spent coffee grounds

The extraction of antioxidant phenolic compounds from spent coffee grounds (SCG) was studied. Experimental assays were carried out by the autohydrolysis technique and the effect of the process variables temperature, water/SCG ratio and extraction time on the amount of phenolic compounds and antioxidant activity of the produced extracts was evaluated. The variables were combined according to a 23 central composite design. The statistical model revealed that the optimum condition to produce extracts with high content of phenolic compounds (35.07 mg GAE/g SCG) and antioxidant activity (FRAP = 0.25 mmol Fe(II)/g SCG, DPPH = 121.7 μmol TE/g SCG, ABTS = 130.0 μmol TE/g SCG, TAA = 64.17 mg α-TOC/g SCG) was achieved when maximizing the process variables (temperature = 200 °C, ratio = 15 ml/g and time = 50 min)

Toxicity of four Cuban botanical derivatives against two stored-products coleopteran pests: Poster

Plants are a source of substances for protection of stored products. The Cuban flora has not yet been fully studied as a source of pesticides for postharvest protection, partly due to its great diversity. The toxicity of four Cuban plant derivatives against Lasioderma serricorne (F.) and Sitophilus zeamais Motschulsky was investigated. The anti-insect activity of the powders and the essential oil from plants belonging to Asteraceae, Fabaceae and Piperaceae was tested. Mortality and emergence of adult insects and the repellent effect of products were evaluated. Two products derived from Piper aduncum subsp. ossanum, caused high mortality (81,6 and 100%), reduced emergence (27,9 and 0,4%) and exhibited strong repellent activity on L. serricorne. Against S. zeamais, treatments with the highest mortality values were stems of Lonchocarpus punctatus (72,4%), seeds and stems of Canavalia ensiformis (64,9 and 69,9%), and leaves of Tithonia diversifolia (67,2%). The progeny production of S. zeamais was inhibited by powders of L. punctatus stems (31,8%), C. ensiformis seeds (40,5%), leaves (43,7%) and stems (30,6%), and T. diversifolia leaves (38,7%). The stems of C. ensiformis, leaves of T. diversifolia and L. punctatus had the highest repellent effect. These products have potential for small-scale treatments of grains for protection against both insects, and P. aduncum subsp. ossanum-based products to control L. serricorne infestation in tobacco. Identification of local candidates to develop effective and safe pesticides offers new alternatives to the Cuban agriculture in the control of storage pests.Plants are a source of substances for protection of stored products. The Cuban flora has not yet been fully studied as a source of pesticides for postharvest protection, partly due to its great diversity. The toxicity of four Cuban plant derivatives against Lasioderma serricorne (F.) and Sitophilus zeamais Motschulsky was investigated. The anti-insect activity of the powders and the essential oil from plants belonging to Asteraceae, Fabaceae and Piperaceae was tested. Mortality and emergence of adult insects and the repellent effect of products were evaluated. Two products derived from Piper aduncum subsp. ossanum, caused high mortality (81,6 and 100%), reduced emergence (27,9 and 0,4%) and exhibited strong repellent activity on L. serricorne. Against S. zeamais, treatments with the highest mortality values were stems of Lonchocarpus punctatus (72,4%), seeds and stems of Canavalia ensiformis (64,9 and 69,9%), and leaves of Tithonia diversifolia (67,2%). The progeny production of S. zeamais was inhibited by powders of L. punctatus stems (31,8%), C. ensiformis seeds (40,5%), leaves (43,7%) and stems (30,6%), and T. diversifolia leaves (38,7%). The stems of C. ensiformis, leaves of T. diversifolia and L. punctatus had the highest repellent effect. These products have potential for small-scale treatments of grains for protection against both insects, and P. aduncum subsp. ossanum-based products to control L. serricorne infestation in tobacco. Identification of local candidates to develop effective and safe pesticides offers new alternatives to the Cuban agriculture in the control of storage pests

Abdominal Obesity Associated To Medical-Related Absenteeism At A Company Of Metal-Mechanical Industry In Cali, Colombia

Con el objetivo de examinar la frecuencia de obesidad abdominal y el ausentismo laboral por causa médica, se realizó un estudio transversal en 185 varones pertenecientes a una industria metalmecánica. En ellos, además de datos sociodemográficos, se recogió datos antropométricos y se midió la circunferencia de cintura (CC) en centímetros como indicador de obesidad abdominal. Se encontró, además de una alta frecuencia de obesidad abdominal (28,7%), que los trabajadores con obesidad abdominal presentaron mayor frecuencia, mayor tiempo y mayores costos por las incapacidades médicas. Se concluye que la obesidad abdominal en esta muestra fue altamente frecuente; no obstante, al tratarse de un riesgo reversible, las empresas podrían beneficiarse, en términos de ausentismo laboral, de programas preventivo promocionales destinados a controlar este problemaThe aim of this study was examined the abdominal obesity prevalence and association with medical-related absenteeism. A cross-sectional study in 185 men from the metal-mechanical industry was conducted. Sociodemografic and antropometrics data of was gathered, waist circumference was measured as an indicator of abdominal obesity. The prevalence of central obesity was 28.7 %. Subjects with higher values of central obesity showed higher frequency, higher duration and higher costs of medical-related absenteeism, however, this relationship was not significant. We conclude that abdominal obesity is highly frequent in this sample; however, since it’s a reversible risk, enterprises could get benefits from preventive and promotional programs destiny to control this problem

Transport and Health: A Look at Three Latin American Cities

Transport is associated with environmental problems, economic losses, health and social inequalities. A number of European and US cities have implemented initiatives to promote multimodal modes of transport. In Latin America changes are occurring in public transport systems and a number of projects aimed at stimulating non-motorized modes of transport (walking and cycling) have already been implemented. Based on articles from peer-reviewed academic journals, this paper examines experiences in Bogota (Colombia), Curitiba (Brazil), and Santiago (Chile), and identifies how changes to the transport system contribute to encourage active transportation. Bus rapid transit, ciclovias, bike paths/lanes, and car use restriction are initiatives that contribute to promoting active transportation in these cities. Few studies have been carried out on the relationship between transport and physical activity. Car ownership continues to increase. The public health sector needs to be a stronger activist in the transport policy decision-making process to incorporate health issues into the transport agenda in Latin America

The embedded clusters DBS 77, 78, 102, and 160-161, and their link with the interstellar medium

Aims. We report on a study of the global properties of some embedded clusters that are found in the fourth quadrant of the Milky Way. We aim to clarify some issues that relate to their location in the Galaxy and their stellar formation processes. Methods. We performed BVI photometric observations in the region of DBS 77, 78, 102, 160, and 161 clusters, and infrared spectroscopy in the DBS 77 region. These were complemented with JHK data from the VVV survey combined with the 2MASS catalogue, and used mid-infrared information from the GLIMPSE catalogue. We also searched for HI data from the SGPS and PMN radio surveys, and previous spectroscopic stellar classifications. The spectroscopic and photometric information enabled us to estimate the spectral classification of the brightest stars for each of the studied regions. On the other hand, we used radio data to investigate the interstellar material parameters and the continuum sources that are probably associated with the respective stellar components. Results. We estimated the basic physical parameters of the clusters (reddening, distance, age, and initial mass function). We searched for HII regions located near to the studied clusters and we analyzed the possible links between them. In the particular case of the DBS 160-161 clusters, we identified the HI bubble B332.5-0.1-42 that is located around them. We found that the mechanical energy injected in to the interstellar medium by the more massive stars of this couple of clusters was enough to generate the bubble.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La PlataInstituto Argentino de Radioastronomí

Effusive silicic volcanism in the Central Andes: The Chao dacite and other young lavas of the Altiplano-Puna Volcanic Complex

The largest known Quaternary silicic lava body in the world is Cerro Chao in north Chile, a 14-km-long coulée with a volume of at least 26 km³. It is the largest of a group of several closely similar dacitic lavas erupted during a recent (< 100,000 year old) magmatic episode in the Altiplano-Puna Volcanic Complex (APVC; 21-24°S) of the Central Andean Volcanic Zone. The eruption of Chao proceeded in three phases. Phase 1 was explosive and produced ∼1 km³ of coarse, nonwelded dacitic pumice deposits and later block and ash flows that form an apron in front of the main lava body. Phase 2 was dominantly effusive and erupted ∼22.5 km³ of magma in the form of a composite couleé covering ∼53 km² with a 400-m-high flow front and a small cone of poorly expanded pumice around the vent. The lava is homogeneous with rare flow banding and vesicular tops and selvages. Ogives (flow ridges) reaching heights of 30 m form prominent features on its surface. Phase 3 produced a 6-km-long, 3-km-wide flow that emanated from a collapsed dome. Ogives are subdued, and the lava is glassier than that produced in previous phases. All the Chao products are crystal-rich high-K dacites and rhyodacites with phenocrysts of plagioclase, quartz, hornblende, biotite, sphene, rare sanidine, and oxides. Phenocryst contents reach 40–60 vol % (vesicle free) in the main phase 2 lavas but are lower in the phase 1 (20–25%) and phase 3 (∼40%) lavas. Ovoid andesitic inclusions with vesicular interiors and chilled margins up to 10 cm are found in the later stages of phase 2 and compose up to 5% of the phase 3 lava. There is little evidence for preemptive zonation of the magma body in composition, temperature (∼840°C), fO₂ (10⁻¹¹), or water content, so we propose that eruption of the Chao complex was driven by intrusion of fresh, hot andesitic magma into a crystallizing and largely homogeneous body of dacitic magma. Morphological measurements suggest that the Chao lavas had internal plastic viscosities of 10¹⁰ to 10¹²Pa s, apparent viscosities of 10⁹ Pa s, surface viscosities of 10¹⁵ to 10²⁴ Pa s, and a yield strength of 8 × 10⁵ Pa. These estimates indicate that Chao would have exhibited largely similar rheological properties to other silicic lava extrusions, notwithstanding its high phenocryst content. We suggest that Chao's anomalous size is a function of both the relatively steep local slope (20° to 3°) and the available volume of magma. The eruption duration for Chao's emplacement is thought to have been about 100 to 150 years, with maximum effusion rates of about 25 m³ s⁻¹ for short periods. Four other lavas in the vicinity with volumes of ∼5 km³ closely resemble Chao and are probably comagmatic. The suite as a whole shares a petrologic and chemical similarity with the voluminous regional Tertiary to Pleistocene ignimbrites of the APVC and may be derived from a zone of silicic magmatism that is thought to have been active since the late Tertiary. Chao and the other young lavas may represent either the waning of this system or a new episode fueled by intrusions of mafic magma.Keywords: model, iron-titanium-oxides, rheological properties, magma chambers, rocks, Chile, flows, eruption

Differential Role of Human Choline Kinase α and β Enzymes in Lipid Metabolism: Implications in Cancer Onset and Treatment

11 pages, 6 figures, 1 table.Background The Kennedy pathway generates phosphocoline and phosphoethanolamine through its two branches. Choline Kinase (ChoK) is the first enzyme of the Kennedy branch of synthesis of 1phosphocholine, the major component of the plasma membrane. ChoK family of proteins is composed by ChoKα and ChoKβ isoforms, the first one with two different variants of splicing. Recently ChoKα has been implicated in the carcinogenic process, since it is over-expressed in a variety of human cancers. However, no evidence for a role of ChoKβ in carcinogenesis has been reported. Methodology/Principal Findings Here we compare the in vitro and in vivo properties of ChoKα1 and ChoKβ in lipid metabolism, and their potential role in carcinogenesis. Both ChoKα1 and ChoKβ showed choline and ethanolamine kinase activities when assayed in cell extracts, though with different affinity for their substrates. However, they behave differentially when overexpressed in whole cells. Whereas ChoKβ display an ethanolamine kinase role, ChoKα1 present a dual choline/ethanolamine kinase role, suggesting the involvement of each ChoK isoform in distinct biochemical pathways under in vivo conditions. In addition, while overexpression of ChoKα1 is oncogenic when overexpressed in HEK293T or MDCK cells, ChoKβ overexpression is not sufficient to induce in vitro cell transformation nor in vivo tumor growth. Furthermore, a significant upregulation of ChoKα1 mRNA levels in a panel of breast and lung cancer cell lines was found, but no changes in ChoKβ mRNA levels were observed. Finally, MN58b, a previously described potent inhibitor of ChoK with in vivo antitumoral activity, shows more than 20-fold higher efficiency towards ChoKα1 than ChoKβ. Conclusion/Significance This study represents the first evidence of the distinct metabolic role of ChoKα and ChoKβ isoforms, suggesting different physiological roles and implications in human carcinogenesis. These findings constitute a step forward in the design of an antitumoral strategy based on ChoK inhibition.This work has been supported by grants to JCL from Comunidad de Madrid (GR-SAL-0821-2004), Ministerio de Ciencia e Innovación (SAF2008-03750, RD06/0020/0016), Fundación Mutua Madrileña, and by a grant to ARM from Fundación Mutua Madrileña.Peer reviewe