108 research outputs found

    Impact of sound attenuation on ultrasound-driven yield improvements during olive oil extraction

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    High frequency ultrasound can enhance olive oil extractability industrially. However, the ultrasound attenuation phenomena and their implications on extractability, are not well understood. This work aims at evaluating the ultrasound attenuation effects on the oil extraction efficiency, while providing deeper insights into the physics behind the ultrasound extraction in a heterogeneous medium. Olives were collected and processed both in Italy and Uruguay during their respective harvest seasons. Sound pressure distribution was characterized in a high frequency ultrasound reactor, carrying 3 kg of water or paste, by using an indirect contact hydrophone device at 0.4 MHz or 2 MHz. A through-transmission ultrasonic technique was applied to determine attenuation profiles and coefficients in paste at the central frequency of each transducer, with various paste to water ratios and reactor sizes. Other ultrasound improvements on extractability were evaluated including reduction of malaxation time (10, 30 min), sonication time (2.5, 5 min) and power level (174, 280 W) without water addition and in a reactor with a 14.5 cm transducer to wall distance. However, no sound pressure levels in paste were detectable beyond 9 cm from the transducer at both frequencies. Among the various effects evaluated, an emission frequency of 0.4 MHz better improved extractability compared to 2 MHz. The attenuation profiles corroborated these findings with attenuation coefficients of 3.9 and 5.3 dB/cm measured near the respective frequencies. Improvements in oil extractability due to increasing sonication time and power level were significant (p < 0.05) also when sonicating beyond 14.5 cm and without water addition. Oil extractability improvements were observed even when sound pressure was undetectable beyond 9 cm from the transducer, suggesting that the standing wave oil trapping effect is not the governing mechanism for separation in high attenuation media for large scale systems

    An unaware agenda: interictal consciousness impairments in epileptic patients.

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    Consciousness impairments have been described as a cornerstone of epilepsy. Generalized seizures are usually characterized by a complete loss of consciousness, whereas focal seizures have more variable degrees of responsiveness. In addition to these impairments that occur during ictal episodes, alterations of consciousness have also been repeatedly observed between seizures (i.e. during interictal periods). In this opinion article, we review evidence supporting the novel hypothesis that epilepsy produces consciousness impairments which remain present interictally. Then, we discuss therapies aimed to reduce seizure frequency, which may modulate consciousness between epileptic seizures. We conclude with a consideration of relevant pathophysiological mechanisms. In particular, the thalamocortical network seems to be involved in both seizure generation and interictal consciousness impairments, which could inaugurate a promising translational agenda for epilepsy studies

    Intervención energética en el sector residencial del sur de España: Retos actuales

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    It can be estimated that approximately half of energy consumption in Spanish residential buildings derives from heating and air conditioning systems. It is therefore advisable to invest in retrofitting projects to reduce energy demand. However, although as a rule energy interventions are expected to bring about significant potential energy savings, it should be noted that this is often not so straightforward, particularly in southern Spain, where there are significant deviations from the expected energy scenario. Recent research shows that in many cases there is no direct relationship between energy demand and real energy use, and the low energy rate is combined with deficiencies in comfort conditions. In order to ensure the real cost-efficiency of the actions is essential, further research for defining these behaviours. The European EnergyTIC project is a continuation of the work already carried out in this context by the EFFICACIA and AMEC research projects.En los edificios de viviendas españoles podemos estimar que la mitad del consumo energético se debe a los sistemas de calefacción y refrigeración. En general, resulta aconsejable invertir en proyectos de rehabilitación para limitar su demanda energética, sin embargo, aunque las intervenciones energéticas puedan suponer un significativo potencial de ahorro de energía, habría que manifestar que en muchas situaciones, especialmente en el área sur, no siempre será así, con desviaciones importantes de los comportamientos energéticos esperados. Investigaciones recientes sobre edificios de viviendas protegidas en el Sur de España señalan que no existe habitualmente una relación directa entre demanda de energía y uso real de la misma, asociado el bajo consumo a una carencia de prestaciones de confort. Para rentabilizar las actuaciones es fundamental profundizar en investigación y caracterización de estos comportamientos. En este contexto, se han desarrollado los proyectos de EFFICACIA, AMEC y el proyecto europeo EnergyTIC

    Acute torsion of the gallbladder: a case report

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Pensamiento crítico: reflexiones en torno a su importancia para la autonomía

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    En este artículo se exponen los avances de la investigación: El Pensamiento crítico como camino hacia la Autonomía, adelantada en el Colegio Boyacá de Duitama. La investigación se desarrolla con un enfoque cualitativo, tipo acción educativa. Esta tiene como objetivo potenciar el pensamiento crítico para el desarrollo de la autonomía en los estudiantes de los grados 602 y 1101, de donde se sigue la propuesta metodológica que busca el desarrollo de la autonomía a través del pensamiento crítico. El artículo hace énfasis en el ensayo de Kant: Respuesta a la pregunta ¿Qué es la Ilustración?, y considera las principales premisas expuestas en la Fundamentación de la metafísica de las costumbres de este mismo autor, en lo relacionado con la propuesta investigativa. En primera instancia, se hace una contextualización y descripción diagnóstica; seguidamente, se exponen algunos planteamientos basados en Kant, Adorno y Foucault con relación al pensamiento crítico y su importancia para la autonomía; además, se hace una alusión general a Richard Paul y Linda Elder en cuanto al pensamiento crítico y la educación. Por último, se presenta la propuesta metodológica en relación con los postulados de Paulo Freire referidos al pensamiento crítico y la autonomía, en el campo de la educación y la pedagogía, y se consideran los alcances de la investigación

    Increasing Compliance with Mass Drug Administration Programs for Lymphatic Filariasis in India through Education and Lymphedema Management Programs

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    Global elimination of lymphatic filariasis requires giving drugs at least annually to populations who live at risk of becoming infected with the parasite. At least 80% of people at risk need to take the drugs annually for 5 or more years to stop transmission of the infection. People suffering from the long-term effects of infection, such as swollen legs, benefit from programs that teach self-care of their affected limbs. In this study, we assessed the impact of an educational campaign that, after addressing previously identified predictors of compliance, significantly improved drug compliance. The specific factors improving compliance included knowing about the drug distribution in advance, knowing that everyone is at risk for acquiring the infection, knowing that the drug distribution was for lymphatic filariasis prevention, and knowing at least one component of leg care. We also found that areas with programs to assist people with swollen legs had greater increases in compliance. This research provides evidence that program evaluation can be used to improve drug compliance. In addition, our work shows for the first time that programs to benefit people with swollen legs caused by lymphatic filariasis also increase the participation of people without disease in drug treatment programs

    National Mass Drug Administration Costs for Lymphatic Filariasis Elimination

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    Lymphatic filariasis (LF), commonly known as elephantiasis, is a profoundly disfiguring parasitic disease caused by thread-like nematode worms. This disease can often be disabling, thus reducing the potential productivity of the affected individuals. The WHO places the number of people at risk in 83 countries at 1.307 billion. This study was undertaken in seven countries—Burkina Faso, Ghana, Egypt, Tanzania, the Philippines, the Dominican Republic, and Haiti—using a common protocol to determine the costs of mass drug administration (MDA) programs to interrupt transmission of infection with LF, because there is lack of sufficient information about the costs of these programs. The results demonstrate that LF MDA is affordable and relatively inexpensive when compared to other public health programs. In the context of initiatives for integrating programs for the control and elimination of neglected tropical diseases, this study adds specifically to the relatively scarce body of information about the costs of MDA programs for LF. It also adds to the general knowledge about the application of methods that can be used to estimate the costs and cost-effectiveness of an integrated approach

    A Multicentre Randomized Controlled Trial of the Efficacy and Safety of Single-Dose Praziquantel at 40 mg/kg vs. 60 mg/kg for Treating Intestinal Schistosomiasis in the Philippines, Mauritania, Tanzania and Brazil

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    Control of urinary and intestinal schistosomiasis is based on mass administration of praziquantel at the World Health Organization (WHO) recommended dose of 40 mg/kg, though some countries use 60 mg/kg. This multi-country randomized clinical trial compared the efficacy (cure and egg reduction rates three weeks post-treatment) and safety of these two doses for treating intestinal schistosomiasis in 856 patients in Brazil, Mauritania and Tanzania (Schistosoma mansoni), and The Philippines (S. japonicum). Transmission and infection intensities varied across the sites, but there was no bias or heterogeneity in efficacy outcomes. The two doses are equally effective in curing intestinal schistosomiasis; the higher dose may be less well tolerated, though effects are generally mild and transient. In endemic areas people can be re-infected; one year post-treatment patients on 60 mg/kg had fewer re-infections but this finding is difficult to explain. This study was conducted to respond to the demand for evidence about the dose of praziquantel when deployed in endemic countries. The results, along with those of systematic reviews, support the current WHO recommendation for using praziquantel at 40 mg/kg and should inform policy decisions in countries. The Philippines has already changed from 60 to 40 mg/kg after this study

    A Community-Based Study of Factors Associated with Continuing Transmission of Lymphatic Filariasis in Leogane, Haiti

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    Seven rounds of mass drug administration (MDA) have been administered in Leogane, Haiti, an area hyperendemic for lymphatic filariasis (LF). Sentinel site surveys showed that the prevalence of microfilaremia was reduced to <1% from levels as high as 15.5%, suggesting that transmission had been reduced. A separate 30-cluster survey of 2- to 4-year-old children was conducted to determine if MDA interrupted transmission. Antigen and antifilarial antibody prevalence were 14.3% and 19.7%, respectively. Follow-up surveys were done in 6 villages, including those selected for the cluster survey, to assess risk factors related to continued LF transmission and to pinpoint hotspots of transmission. One hundred houses were mapped in each village using GPS-enabled PDAs, and then 30 houses and 10 alternates were chosen for testing. All individuals in selected houses were asked to participate in a short survey about participation in MDA, history of residence in Leogane and general knowledge of LF. Survey teams returned to the houses at night to collect blood for antigen testing, microfilaremia and Bm14 antibody testing and collected mosquitoes from these communities in parallel. Antigen prevalence was highly variable among the 6 villages, with the highest being 38.2% (Dampus) and the lowest being 2.9% (Corail Lemaire); overall antigen prevalence was 18.5%. Initial cluster surveys of 2- to 4-year-old children were not related to community antigen prevalence. Nearest neighbor analysis found evidence of clustering of infection suggesting that LF infection was focal in distribution. Antigen prevalence among individuals who were systematically noncompliant with the MDAs, i.e. they had never participated, was significantly higher than among compliant individuals (p<0.05). A logistic regression model found that of the factors examined for association with infection, only noncompliance was significantly associated with infection. Thus, continuing transmission of LF seems to be linked to rates of systematic noncompliance
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