Experimental Estimation of Slipping in the Supporting Point of a Biped Robot

When developing a gait cycle on a low-friction surface, a biped robot eventually tends to slip. In general, it is commonto overcome this problem by means of either slow movements or physical adaptations of the robot at the contact pointwith the walking surface in order to increase the frictional characteristics. In the case of slipping, several types ofsensors have been used to identify the relative displacement at the contact point of the supporting leg with the walkingsurface for control purposes. This work is focused on the experimental implementation of a low-cost force sensor as ameasurement system of the slipping phenomenon. It is shown how, supported on a suitable change of coordinates,the force measurement at the contact point is used to obtain the total displacement at the supporting point due to thelow-friction conditions. This is an important issue when an accurate Cartesian task is required

Delineation of site‐specific management zones using estimation of distribution algorithms

In this paper, we present a novel methodology to solve the problem of delineating homogeneous site-specific management zones (SSMZ) in agricultural fields. This problem consists of dividing the field into small regions for which a specific rate of inputs is required. The objec- tive is to minimize the number of management zones, which must be homogeneous according to a specific soil property: physical or chem- ical. Furthermore, as opposed to oval zones, SSMZ with rectangular shapes are preferable since they are more practical for agricultural technologies. The methodology we propose is based on evolutionary computation, specifically on a class of the estimation of distribution algorithms (EDAs). One of the strongest contributions of this study is the representation used to model the management zones, which gener- ates zones with orthogonal shapes, e.g., L or T shapes, and minimizes the number of zones required to delineate the field. The experimental results show that our method is efficient to solve real-field and ran- domly generated instances. The average improvement of our method consists in reducing the number of management zones in the agricul- tural fields concerning other operations research methods presented in the literature. The improvement depends on the size of the field and the level of homogeneity established for the resulting management zones.IT1244-19 TIN2016-78365-R PID2019-104966GB-I0

Influence of telomerase activity and initial distribution on human follicular aging: Moving from a discrete to a continuum model

Producción CientíficaA discrete model is proposed for the temporal evolution of a population of cells sorted according to their telomeric length. This model assumes that, during cell division, the distribution of the genetic material to daughter cells is asymmetric, i.e. chromosomes of one daughter cell have the same telomere length as the mother, while in the other daughter cell telomeres are shorter. Telomerase activity and cell death are also taken into account. The continuous model is derived from the discrete model by introducing the generational age as a continuous variable in , being the Hayflick limit, i.e. the number of times that a cell can divide before reaching the senescent state. A partial differential equation with boundary conditions is obtained. The solution to this equation depends on the initial telomere length distribution. The initial and boundary value problem is solved exactly when the initial distribution is of exponential type. For other types of initial distributions, a numerical solution is proposed. The model is applied to the human follicular growth from preantral to preovulatory follicle as a case study and the aging rate is studied as a function of telomerase activity, the initial distribution and the Hayflick limit. Young, middle and old cell-aged initial normal distributions are considered. In all cases, when telomerase activity decreases, the population ages and the smaller the value, the higher the aging rate becomes. However, the influence of these two parameters is different depending on the initial distribution. In conclusion, the worst-case scenario corresponds to an aged initial telomere distribution.Ministerio de Ciencia e Innovación (PGC2018-101443-B-I00)CDTI and FEDER (IDI-20190160 and IDI-20181240)Instituto de Salud Carlos III (Spanish Government) (PI20/00252)FINOX through FORWARD 2018-6 to E.V. and J.A.G.V. and by IVIRMA (2004-FIVI-041-MV; 1711-FIVI-111-MV; 1707-FIVI-084-MV; 1711-FIVI-112-MV; 2207-MAD-093-MV)

Equivalence of two approaches for the inhomogeneous density in the canonical ensemble

In this article we show that the inhomogeneous density obtained from a density-functional theory of classical fluids in the canonical ensemble (CE), recently presented by White et al [Phys. Rev. Lett. 84 (2000) 1220], is equivalent to first order to the result of the series expansion of the CE inhomogeneous density introduced by Gonzalez et al [Phys. Rev. Lett. 79 (1997) 2466].Comment: 6 pages, RevTe

Identification and quantification of pathogenic helminth eggs using a digital image system

AbstractA system was developed to identify and quantify up to seven species of helminth eggs (Ascaris lumbricoides -fertile and unfertile eggs-, Trichuris trichiura, Toxocara canis, Taenia saginata, Hymenolepis nana, Hymenolepis diminuta, and Schistosoma mansoni) in wastewater using different image processing tools and pattern recognition algorithms. The system was developed in three stages. Version one was used to explore the viability of the concept of identifying helminth eggs through an image processing system, while versions 2 and 3 were used to improve its efficiency. The system development was based on the analysis of different properties of helminth eggs in order to discriminate them from other objects in samples processed using the conventional United States Environmental Protection Agency (US EPA) technique to quantify helminth eggs. The system was tested, in its three stages, considering two parameters: specificity (capacity to discriminate between species of helminth eggs and other objects) and sensitivity (capacity to correctly classify and identify the different species of helminth eggs). The final version showed a specificity of 99% while the sensitivity varied between 80 and 90%, depending on the total suspended solids content of the wastewater samples. To achieve such values in samples with total suspended solids (TSS) above 150 mg/L, it is recommended to dilute the concentrated sediment just before taking the images under the microscope. The system allows the helminth eggs most commonly found in wastewater to be reliably and uniformly detected and quantified. In addition, it provides the total number of eggs as well as the individual number by species, and for Ascaris lumbricoides it differentiates whether or not the egg is fertile. The system only requires basically trained technicians to prepare the samples, as for visual identification there is no need for highly trained personnel. The time required to analyze each image is less than a minute. This system could be used in central analytical laboratories providing a remote analysis service

Abordaje transvasto mínimamente invasivo versus abordaje parapatelar medial convencional en la artroplastia total de rodilla en pacientes con gonartrosis: estudio prospectivo comparativo no randomizado

Objetivos: valorar y comparar los resultados a corto plazo de la artroplastia total de rodilla realizada mediante dos vías de abordaje. Material y métodos: estudio prospectivo comparativo que compara abordaje parapatelar medial (24 pacientes) y transvasto mínimamente invasivo (25 pacientes) en artroplastia total de rodilla. Se incluyeron pacientes con gonartrosis grado IV de la clasificación de Kellgren-Lawrence y se excluyeron aquellos menores de 50 años, deformidad en varo (> 15º) o valgo (> 10º), artrosis postraumática, artritis reumatoide, cirugías de revisión, osteotomías correctoras previas, IMC > 40 kg/m2, infección activa local o sistémica y/o deterioro mental. Resultados: se encontraron diferencias estadísticamente significativas en dolor del primer y segundo día postoperatorios a favor del abordaje mínimamente invasivo (1º día: 3,8 ± 2,5 vs. 6,7 ± 2,1; p< 0,001. 2º día: 3 ± 2,1 vs. 6 ± 2; p< 0,001). Conclusiones: no existen diferencias relevantes entre ambos abordajes, por lo que se recomienda la utilización del abordaje con el que el cirujano se encuentre más cómodo y familiarizadoAim: Assess and compare short-term outcomes of total knee arthroplasty performed using two surgical approaches. Material and methods: a prospective study with 49 patients comparing medial parapatellar approach (24 patients) and minimally invasive trans-vastus access (25 patients) in total knee replacement. The patients included suffered knee osteoarthritis grade IV the Kellgren-Lawrence’s classification. Exclusion criteria were age under 50 years, large axial deformity (varus deformity > 15° or valgus > 10°), posttraumatic osteoarthritis, rheumatoid arthritis, revision surgeries, previous osteotomies, BMI> 40 kg/m2 and of course local or systemic active infection and mental impairment. Results: statistically significant differences were found for pain in first and second postoperative days for the minimally invasive approach (1st day: 3.8 ± 2.5 vs. 6.7 ± 2.1; p <0.001. 2nd day: 3 ± 2.1 vs. 6 ± 2; p <0.001). Conclusions: there are not significant differences between mini and standard approaches in knee replacement, so decision about which access to use in knee reconstruction surgery depends on surgeon’s preferences

Civil society participation in international governance : the UN and the WTO compared

Civil society participation has become a buzzword in the debate about the legitimacy and accountability of international governance. Many organizations, prominently among them the World Trade Organization (WTO), have come under considerable pressure to open up their policy-making process towards non-state actors. Although the WTO has become more transparent in recent years, direct stakeholder access to its policy making is still denied. This situation is often contrasted with that at the United Nations (UN), where there is (allegedly) much more formally regulated and more substantial participation of civil society. In this paper, we compare the patterns of participation in these two organizations and seek to identify some common dynamics. We present a general framework for analysis based on a model of the policy cycle that allows us to distinguish ‘push’ and ‘pull’ factors that determine cooperation in different phases of policy making. In our empirical study, we find that in the WTO, there are few incentives for the organization itself to pull civil society actors into its policy-making process. Agendasetting is the task of governments; research and analysis is delivered by the Secretariat; compliance control is undertaken jointly by the organization and its members. To push the door to trade policy making open, civil society can only rely on public shaming, that is, threatening to undermine the organization’s legitimacy as it violates widely accepted standards of good governance. In the UN system, there is in fact more cooperation, but it remains largely limited to the policy phases of agenda-setting, research and analysis and compliance control. Quite like the WTO, the UN protects an intergovernmental core of policy making in which cooperation with civil society remains at the discretion of state parties. Evidence for this are informal and ad hoc ways of collaboration and a lack of participatory rights for non-state actors in the Security Council and the General Assembly. We conclude that studying civil society participation in international public organizations through the lens of the policy cycle can give us a fine-grained picture of cooperative arrangements and enables us to identify potentials for cooperation as well as exclusion. Yet, we also observed two other factors at work that were not really grasped by the model of the policy cycle. First, the institutional culture of organizations can be more or less amenable to civil society. Second, organizations are susceptible to campaigns for ‘good governance’ that invoke standards of due process and may open the door to nonstate actors

Fractura de Maisonneuve abierta: una entidad infrecuente: a propósito de un caso y revisión de la literatura

Introducción. La fractura de Maisonneuve representa aproximadamente el 5% de todas las fracturas de tobillo tratadas quirúrgicamente. Debido a que suelen ser fracturas cerradas, presentamos el caso de una fractura de Maisonneuve abierta por su infrecuencia. Caso Clínico. Varón de 63 años que acudió a urgencias tras traumatismo de miembro inferior derecho. En la exploración se evidenció una solución de continuidad de la piel en cara medial de tobillo con exposición de maléolo tibial. La radiografía mostró una apertura de la mortaja tibio-peronea y una fractura espiroidea en el tercio proximal del peroné. Se realizó osteosíntesis con dos tornillos canulados. Tras 12 meses de seguimiento, el paciente presenta una puntuación media de 86,8 puntos en la escala AOFAS. Conclusión. Ante una luxación abierta de tobillo, debe sospecharse una fractura de Maisonneuve aunque sea poco frecuente, siendo la osteosíntesis una opción terapéutica eficaz en este tipo de fracturas.Introduction. Maisonneuve fracture represents approximately 5% of all surgically treated ankle fractures. Because these fractures are usually closed, we present the case of a Maisonneuve open fracture owing to its rarity. Case report. A 63-year-old man presented to his emergency department after a right leg trauma. Physical examination revealed a skin solution of continuity above the ankle joint, with a medial tibial malleolus exposure. The radiography showed an opening of the tibiofibular mortise and a spiral fracture of the proximal third of the fibula. Fixation with two cannulated screws was performed. After 12 months of follow up, the patient has an average score of 86.8 points on the AOFAS scale. Conclusion. In the face of an open ankle dislocation, a Maisonneuve open fracture should be suspected in spite of its infrequency, being the osteosynthesis an effective therapeutic option in this type of fracture

Selective oxidation of alkyl and aryl glyceryl monoethers catalysed by an engineered and immobilised glycerol dehydrogenase

Enzymes acting over glyceryl ethers are scarce in living cells, and consequently biocatalytic transformations of these molecules are rare despite their interest for industrial chemistry. In this work, we have engineered and immobilised a glycerol dehydrogenase from Bacillus stearothermophilus (BsGlyDH) to accept a battery of alkyl/aryl glyceryl monoethers and catalyse their enantioselective oxidation to yield the corresponding 3-alkoxy/aryloxy-1-hydroxyacetones. QM/MM computational studies decipher the key role of D123 in the oxidation catalytic mechanism, and reveal that this enzyme is highly enantioselective towards S-isomers (ee > 99%). Through structure-guided site-selective mutagenesis, we find that the mutation L252A sculpts the active site to accommodate a productive configuration of 3-monoalkyl glycerols. This mutation enhances the kcat 163-fold towards 3-ethoxypropan-1, 2-diol, resulting in a specific activity similar to the one found for the wild-type towards glycerol. Furthermore, we immobilised the L252A variant to intensify the process, demonstrating the reusability and increasing the operational stability of the resulting heterogeneous biocatalyst. Finally, we manage to integrate this immobilised enzyme into a one-pot chemoenzymatic process to convert glycidol and ethanol into 3-ethoxy-1-hydroxyacetone and (R)-3-ethoxypropan-1, 2-diol, without affecting the oxidation activity. These results thus expand the uses of engineered glycerol dehydrogenases in applied biocatalysis for the kinetic resolution of glycerol ethers and the manufacturing of substituted hydroxyacetones. This journal i