623 research outputs found
Characterization of the Physical Properties of the Coconut Fiber Residue With a View to its Agroindustrial Use
Ecuador is a multi-climatic country with the capacity to host a large number of plant species; one example is the coconut (Cocos nucifera), an ancestral food of tropical areas and warm climates, which is considered as raw material for various industrial processes, such as obtaining fats, oils, candies, etc. However, the external part of the coconut constituted by the bast or mesocarp has not been properly exploited. Coconut bast, which has high fiber content (coir fiber), from which three main types can be distinguished: long and thin, coarse, and shorter type, can become an agroindustrial alternative due to its mechanical properties. These properties are as good or better than synthetic fibers or polyester. This research therefore aims to characterize the physical parameters that determine the functionality of coconut fiber, such as its length, softness, brightness, color, diameter, and its appearance or slenderness, which is the relationship between length and diameter. This research also contributes to solving the environmental problem of waste generated by coconut production, moving towards a sustainable economy from an environmental point of view. This work determines that coconut fiber is composed of cellulose and wood that has low heat conductivity and impact resistance, and that its resistance and durability make it an adequate raw material in several production sectors.
Keywords: coconut fiber, characterization, properties, agribusiness.
Resumen
El Ecuador es un país multi climático con la capacidad de alojar una gran cantidad de especies vegetales, un ejemplo de ello es el coco (Cocos nucifera) un alimento ancestral de zonas tropicales y climas cálidos, este es considerado como materia prima de diversos procesos industriales como obtención de grasas, aceites, confites, etc., sin embargo, la parte externa del coco constituida por la estopa o mesocarpio no ha sido correctamente explotada. La estopa del coco por su alto contenido de fibra (fibra bonote), de la cual se pueden distinguir tres tipos principales: una larga y fina, una tosca y una más corta, se convertir en una alternativa agroindustrial debido a sus propiedades físico - mecánicas que son tan buenas o mejores que fibras sintéticas o el poliéster. Esta investigación tuvo por objeto caracterizar los parámetros físicos que describan la funcionalidad de la fibra de coco como son su longitud, suavidad, brillo, color. Para lo cual se realizó un estadística descriptiva de medidas de tendencia central como la media, se analizaron un total de 10 muestras de fibra de coco tomadas al azar de los 15 Kg de fibra obtenida de 50 cocos, teniéndose como resultado que para la suavidad el 80% de los participantes la ubican en el octavo lugar y el restante 20% en el noveno, lo que permite inferir que se tara de una fibra gruesa, rígida y áspera, para el brillo y luminosidad el 90% de los observadores determinaron que la fibra no posee esta característica. El 70% de las panelistas delimitaron que el color característico de la fibra fue el café claro y el restante 30% la considera de color beige.
Palabras clave: fibra de coco, caracterización, propiedades, agroindustria
Role of topical magnesium in post-operative sore throat: A systematic review and meta-analysis of randomised controlled trials
Effect of urban vs. rural residence on the association between atopy and wheeze in Latin America: findings from a case-control analysis.
BACKGROUND: The association between atopy and asthma is attenuated in non-affluent populations, an effect that may be explained by childhood infections such as geohelminths. OBJECTIVE: To investigate the association between atopy and wheeze in schoolchildren living in urban and rural areas of Ecuador and examine the effects of geohelminths on this association. METHODS: We performed nested case-control studies among comparable populations of schoolchildren living in rural communities and urban neighbourhoods in the Province of Esmeraldas, Ecuador. We detected geohelminths in stool samples, measured recent wheeze and environmental exposures by parental questionnaire, and atopy by specific IgE (sIgE) and skin prick test (SPT) reactivity to aeroallergens. RESULTS: Atopy, particularly sIgE to house dust mite (HDM), was more strongly associated with recent wheeze in urban than rural schoolchildren: (urban, adj. OR 5.19, 95% CI 3.37-8.00, P < 0.0001; rural, adj. OR 1.81, 95%CI 1.09-2.99, P = 0.02; interaction, P < 0.001). The population fractions of wheeze attributable to atopy were approximately two-fold greater in urban schoolchildren: SPT to any allergen (urban 23.5% vs. rural 10.1%), SPT to HDM (urban 18.5% vs. rural 9.6%), and anti-HDM IgE (urban 26.5% vs. rural 10.5%), while anti-Ascaris IgE was related to wheeze in a high proportion of rural (49.7%) and urban (35.4%) children. The association between atopy and recent wheeze was attenuated by markers of geohelminth infections. CONCLUSIONS: Our data suggest that urban residence modifies the association between HDM atopy and recent wheeze, and this effect is explained partly by geohelminth infections
Unreflective use of old data sources produced echo chambers in the water-electricity nexus
This meta-analysis of over 2,400 papers tracks the influence of older publications that have 'echoed' through the decades, cited in countless publications and creating a potentially false confirmation bias. Echo chambers in science describe the amplification and repetition of information within closed networks. Frequently used data sources can cause echo chambers as scientists keep reading similar outputs from different sources, creating false perceptions of certainty and variety of data sources. We show this effect by studying the scientific and grey literature on water use by electricity systems. The power sector is the largest contributor to anthropogenic carbon emissions and the second largest water consumer. We have assessed the scope and references of 2,426 papers and created a citation network to trace original data sources. Most data sources used for the last 30 years originate from a few old US publications, recently also Chinese, that echo through publications. This echo effect, also reflected in recent scientific publications, creates a confirmation bias, also facilitating double counting of the water intensities of electricity generation. This example from sustainability science warns of the risk of echo chambers in other scientific disciplines
Molecular characterization, expression and localization of a peroxiredoxin from the sheep scab mite, Psoroptes ovis
The sheep scab mite, Psoroptes ovis, induces an intensely pruritic exudative dermatitis which is responsible for restlessness, loss of appetite and weight loss. Within the first 24 h of infection, there is a rapid inflammatory influx of eosinophils and apoptosis of the keratinocytes at the site of infection. The former cell type is capable of a sustained respiratory burst, toxic products of which may directly damage the mite and also contribute to lesion formation. Analysis of a P. ovis expressed sequence tag (EST) database identified a number of antioxidant enzyme-encoding sequences, including peroxiredoxin (thioredoxin peroxidase EC 1.11.1.15), all of which may help the mite endure the potentially toxic skin environment. A full length sequence encoding Po-TPx, a protein of 206 amino acids which showed high homology to a peroxiredoxin from the salivary gland of the tick Ixodes scapularis, was amplified from P. ovis cDNA. Recombinant Po-TPx was expressed in bacteria and antiserum to this protein was used to localize native Po-TPx in mite sections. Peroxiredoxin was localized, amongst other sites, to a subpharyngeal region in mite sections. The recombinant protein was recognized by sera from sheep infested with the mite suggesting that it may be secreted or excreted by the mite and interact with the host immune response
Security Policies to Mitigate Attacks VLAN Hopping in the Data Link Layer of LA Networks
A proposal of security policies based on the ISO 27002 standard is presented, which allows to mitigate VLAN HOPPING attacks at the data link layer level in LAN networks, as it is evident that network administrators pay more attention to policies to ensure the layers of the OSI model, so that internal users with certain privileges can take advantage of these vulnerabilities to access valuable information of the organization. For this purpose, a base network infrastructure of the companies in the city of Riobamba-Ecuador was determined as a case study. In this scenario, a standard four-phase Pentesting was performed to test VLAN HOPPING attacks (Switch Spoofing and Double Tagging) before and after applying the proposed policies, resulting in a 100% mitigation of the technological vulnerabilities found and 90% of organizational, operational, and physical vulnerabilities.
Keywords: VLAN HOPPING, Security Policies, Vulnerability Mitigation, Security Mechanism
Virtual reality and physiotherapy in post-stroke functional re-education of the lower extremity: A controlled clinical trial on a new approach
Numerous Virtual Reality (VR) systems address post-stroke functional recovery of the lower extremity (LE), most of them with low early applicability due to the gait autonomy they require. The aim of the present study was to evaluate the feasibility of a specific VR treatment and its clinical effect on LE functionality, gait, balance, and trunk control post-stroke. A controlled, prospective, clinical trial was carried out with 20 stroke patients, who were divided into two groups: the first group (VR + CP; n = 10) received combined therapy of 1 h VR and 1 h of conventional physiotherapy (CP) and the second group (CP; n = 10) received 2 h of CP (5 days/week, for 3 weeks). The following pre-post-intervention measuring scales were used: Functional Ambulatory Scale (FAC), Functional Independence Measure (FIM), Fugl-Meyer Assessment (FM), Berg Balance Scale (BBS), and Trunk Control Test (TCT). Only VR + CP showed a significant improvement in FAC. In FIM, CP presented a tendency to significance, whereas VR + CP showed significance. Both groups improved significantly in FM (especially in amplitude/pain in VR + CP and in sensitivity in CP) and in BBS. In TCT, there was a non-significant improvement in both groups. The results indicate that the intervention with VR is a feasible treatment in the post-stroke functional re-education of the LE, with the potential to be an optimal complement of CP
Short-Term Changes in Algometry, Inclinometry, Stabilometry, and Urinary pH Analysis After a Thoracolumbar Junction Manipulation in Patients with Kidney Stones
Objectives: To determine the efficacy of a high-velocity low-amplitude manipulation of the thoracolumbar junction in different urologic and musculoskeletal parameters in subjects suffering from renal lithiasis.
Design: Randomized, controlled blinded clinical study.
Settings/Location: The Nephrology departments of two hospitals and one private consultancy of physiotherapy in Valencia (Spain).
Subjects: Forty-six patients suffering from renal lithiasis.
Interventions: The experimental group (EG, n¿=¿23) received a spinal manipulation of the thoracolumbar junction, and the control group (CG, n¿=¿23) received a sham procedure.
Outcome measures: Pressure pain thresholds (PPTs) of both quadratus lumborum and spinous processes from T10 to L1, lumbar flexion range of motion, stabilometry, and urinary pH were measured before and immediately after the intervention. A comparison between pre- and postintervention phases was performed and an analysis of variance for repeated measures using time (pre- and postintervention) as intrasubject variable and group (CG or EG) as intersubject variable.
Results: Intragroup comparison showed a significant improvement for the EG in the lumbar flexion range of motion (p¿<¿0.001) and in all the PPT (p¿<¿0.001 in all cases). Between-group comparison showed significant changes in PPT in quadratus lumborum (p¿<¿0.001), as well as in the spinous processes of all of the evaluated levels (p¿<¿0.05). No changes in urinary pH were observed (p¿=¿0.419).
Conclusion: Spinal manipulation of the thoracolumbar junction seems to be effective in short term to improve pain sensitivity, as well as to increase the lumbar spine flexion
The pressure-volume-temperature relationship of cellulose
Pressure–volume–temperature (PVT) mea- surements of a-cellulose with different water contents, were performed at temperatures from 25 to 180 °C and pressures from 19.6 to 196 MPa. PVT measurements allowed observation of the combined effects of pressure and temperature on the specific volume during cellulose thermo-compression. All isobars showed a decrease in cellulose specific volume with temperature. This densification is associated with a transition process of the cellulose, occurring at a temperature defined by the inflection point Tt of the isobar curve. Tt decreases from 110 to 40 °C with pressure and is lower as moisture content increases. For isobars obtained at high pressures and high moisture contents, after attaining a minimum, an increase in volume is observed with temperature that may be related to free water evaporation. PVT a-cellulose experimental data was compared with predicted values from a regression analysis of the Tait equations of state, usually applied to synthetic polymers. Good correla- tions were observed at low temperatures and low pressures. The densification observed from the PVT experimental data, at a temperature that decreases with pressure, could result from a sintering phenomenon, but more research is needed to actually understand the cohesion mechanism under these conditions
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