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Microorganism biomass is a sustainable and innovative source of biopolymers, such as proteins and polysaccharides, that is suitable for the development of biodegradable films. The aim of this research was to evaluate the synthesis, morphology, rheology, and morphological and mechanical properties on the production of edible biofilms based on water kefir grains, and compare them with edible films based on thermoplastic compounds from starch (TPS) obtained from taro (Colocasia esculenta) and cassava (Manihot esculenta). Edible biofilms were prepared in solution with 30% wt/wt glycerol relative to starch mass and kefir grain biofilms using the casting method. A stationary rheological analysis was performed on the film-forming suspensions of kefir, taro starch, and cassava starch. Once the films were obtained, a physicochemical and morphological characterization was carried out. Results of the characterization showed the following main aspects: The results indicated an increase in biomass production using muscovado and pineapple peel. The film-forming suspensions had a dilating behavior; however, the results obtained not only show the viscoelastic behavior but also the elastic limit (σ0), which varied from 0.077 to 0.059 Pa for suspensions of water kefir grains and from 0.077 to 0.072 Pa for starch suspensions. These elastic limit variations can be defined as the minimum shear stress required to start the flow, and all these rheological data were adjusted to the Herschel–Bulkley model; the morphological and mechanical characterization of the films obtained showed homogeneous surfaces with transparency and without cracks; regarding the water activity, values lower than 6 were obtained, which indicates that there will be no growth of any microorganism, and the hardness data showed differences between those obtained from kefir and taro and cassava starch. The similar results of the rheological characterization in the formation of the kefir biofilm and the conventional edible starch films, in addition to the similar results in the water activity below 6 and the hardness, points to an attractive alternative capable of replacing the conventional materials with a mass production of biofilms of probiotic microorganisms. The results also revealed that water kefir grains biomass is a viable and innovative source of biodegradable materials, and these grains can be an alternative to conventional established starch materials.

Las rebanadas de ciruela (diámetro 2,5 cm y espesor 0,2 cm) fueron secadas usando el secado vertical por charolas (VTD) y la liofilización (FD). Se utilizaron modelos para determinar la conductividad térmica (k) y el calor específico (Cp). Además, la actividad de agua (aw), el cambio total de color (∆E), el rendimiento de pectina (ypec) y la capacidad de rehidratación fueron investigados. El contenido de humedad de la ciruela seca y liofilizada fue relativamente significativo (p < 0,05). No se encontraron diferencias significativas en términos de aw. Hubo un máximo decremento en k y Cp del 90% y 95% durante el proceso de secado, respectivamente. En términos de calidad, ∆E mostró que las muestras secadas en charolas tuvieron un ligero oscurecimiento (pardeamiento), mientras las muestras liofilizadas tuvieron un color más luminoso en comparación con la muestra fresca. La calidad y las características de rehidratación fueron mayores que las de un producto secado por charolas; sin embargo, VTD podría ser apropiado para la producción industrial debido a sus ventajas de bajo costo y consumo energético. Plum slices (diameter 2.5 cm and thickness 0.2 cm) were dried using vertical tray-drying (VTD) and freeze-drying. Models were used to determine the thermal conductivity (k) and specific heat (Cp). In addition, water activity (aw), colour total change (∆E), pectin yield (ypec) and rehydration capacity were investigated. The moisture content of tray- and freeze-dried plum was relatively significant (p < 0.05). No significant difference was found in terms of aw. There was a maximum decrease in k and Cp of 90% and 91.5% during drying process, respectively. In terms of quality, ∆E showed that tray-dried samples had slight darker (browning), whereas the freeze-dried samples had a lighter colouring compared to the fresh fruit. The quality and rehydration characteristics of freeze-dried plum were higher than that of a tray-dried product; however, VTD could be appropriate for industrial production because of its advantages in lower cost and energy consumption.

At present, strategies on personnel management and development are the most important factors that allow the achievement of institutional objectives. Within this field, there are processes that intervene directly, such as training, remuneration, working conditions, motivation and organizational climate. The human factor constitutes a vital element for the development of the processes of any organization. To analyze the satisfaction of the work environment in the Economic, Administrative and Trade Sciences Department of the University of the Armed Forces, a quantitative study was carried out, to present proposals for solution. The sample was composed of a total of 134 teachers to whom a survey was applied. The questionnaire was composed of 14 questions, distributed in 11 modules that integrate information on the factors that influence the degree of teacher satisfaction in the department, such as the relationship with peers and superiors, recognition, physical environment, supervision and participation in decision making. The Multiple Correspondence analysis was performed. The results confirm the impact of the set of factors such as the relationship between colleagues and supervisors. It is concluded that the physical environment and the recognition for their work influence, in a special way, upon the degree of teacher satisfaction. En la actualidad, las estrategias sobre dirección y desarrollo del personal son el factor más importante que permite el logro de los objetivos institucionales. Dentro de este campo existen procesos que intervienen directamente, tales como la capacitación, remuneración, condiciones de trabajo, motivación y clima organizacional. El factor humano constituye un elemento vital para el desarrollo de los procesos de cualquier organización. Para analizar la satisfacción del ambiente laboral en el Departamento de Ciencias Económicas, Administrativas y del Comercio de la Universidad de las Fuerzas Armadas, se realizó un estudio cuantitativo, para presentar propuestas de solución. La muestra quedó conformada por un total de 134 profesores a los que se les aplicó una encuesta. El cuestionario de ésta quedó compuesto por 14 preguntas, distribuidas en 11 módulos que integran información sobre los factores que influyen en el grado de satisfacción de los docentes del departamento, tales como la relación con los compañeros y superiores, reconocimiento, entorno físico, supervisión y participación en la toma de decisiones. Se realizó el análisis de Correspondencia Múltiple. Los resultados confirman el impacto que tiene el conjunto de factores como la relación entre compañeros y supervisores. Se concluyen que el entorno físico y el reconocimiento por su trabajo influyen, de manera especial, en el grado de satisfacción de los docentes.

This work arises from the constant concern about the teaching performance at the level of higher education institutions and the relationship that this has with the organizational culture that the institution professes. Higher education institutions require a good teaching performance and also to have good interpersonal relationships, teamwork and excellent communication. When a poor organizational culture is observed in the institution, there is also a low teaching performance. The purpose of the study is to present the methodology and tools that will allow universities to determine the relationship between these two variables. In this sense, according to previous research, it is based on the premise and the assumption that there is a significant relationship between the organizational culture and the teaching performance; however, it is necessary to demonstrate it by applying one or more tools that support this relationship. With the results that can be obtained from them, one can see the strengths and weaknesses that will have great value in educational institutions, according to their own situation and needs. Este trabajo surge de la preocupación constante sobre el desempeño docente a nivel de instituciones de educación superior y la relación que este tiene con la cultura organizacional que la institución profesa. Las instituciones de educación superior (IES) requieren de un buen desempeño docente y que además existan buenas relaciones interpersonales, trabajo en equipo y una excelente comunicación. Cuando en la institución se observa una deficiente cultura organizacional, también se observa un bajo desempeño docente. El estudio tiene como finalidad presentar la metodología y herramientas que le permitan a las universidades determinar la relación existente entre estas dos variables. En tal sentido, de acuerdo a las investigaciones previas, se parte de la premisa y el supuesto que existe una relación significativa entre la cultura organizacional y el desempeño docente; sin embargo, es necesario demostrarlo mediante la aplicación de una o más herramientas que sustenten esta relación. Con los resultados que se puedan obtener de las mismas, se podrán observar fortalezas y debilidades que tendrán gran valor en las instituciones educativas de acuerdo con su propia situación y necesidades.&nbsp

The purpose of this study was to investigate how the properties of Mexican kefir grains (MKG) are affected by the operating parameters used in the freeze-drying process. The factors investigated were the freezing time (3&ndash, 9 h), freezing temperature (&minus, 20 to &minus, 80 &deg, C), pressure (0.2&ndash, 0.8 mbar), and lyophilization time (5&ndash, 20 h). The maximum range of change and one-way analysis of variance showed that lyophilization time and freezing time significant affects (p &lt, 0.05) the response variables, residual moisture content and water activity, and pressure had a significant effect on the color difference and survival rate of probiotic microorganisms. The best drying conditions were a freezing time of 3 h, a freezing temperature of &minus, 20 &deg, C, a pressure of 0.6 mbar, and a lyophilization time of 15 h. Under these conditions, we obtained a product with residual moisture content below 6%, water activity below 0.2, and survival rates above 8.5 log cfu per gram of lactic acid bacteria and above 8.6 log for yeast.

The application of a variable control structure for tubular reactors, based on multiple temperature measurements, is explored. The proposed structure allows the controller to adapt to temperature error variations along the tubular reactor. Controllers can be designed from simple input-output first-order dynamical models obtained from step responses and are coupled with a dynamic law for assigning a variable weight to conventional feedback cascade control loops. The simulation results show that the variable structure based on linear proportional-integral controllers enhances the performance and robustness properties of conventional cascade schemes for controlling the outlet reactor concentration. Major advantages are shown in the face of a variety of concentration and temperature feed disturbances.

This work presents a study on the agitation rate effects on the average diameter (% volume D(4,3)) in the batch crystallization of sugar cane in pilot-scale process. The mathematical model presented in this work includes the population balance equation (PBE), the mass and energy balances, and the kinetics equations of nucleation and growth rate. The kinetic parameters were calculated from optimization using experimental data obtained from a pilot-scale process. An uncertainty analysis was performed and used to specify robust agitation trajectories that minimize the variations of crystal size from batch to batch. Four cases studies are presented to obtain 920, 1000, 1200, and 1300 μm of D(4,3) subject to a constraint in the formed crystal mass (FCM) of 4700 g under uncertainty in the kinetic parameters. The resulting robust agitation trajectories were implemented in the pilot-scale process. Comparisons between experimental data and the model predictions are presented.

This paper presents a control strategy based on stage temperature measurements to control composition of the products in a Petlyuk-type distillation column. This column is formed by a prefractionator in which feed is introduced and a main column from which three product streams are extracted. Prefractionator and main-column modules are connected through the exchange of liquid and vapor streams resulting in a strong interaction that can result in operating problems, poor control performance, and instability due to their complex structure. Different steady-state methods for the selection of appropriate control structures were analyzed. The control structure comprises four controllers implemented as follows: three Proportional-Integral (PI) controllers to regulate the temperature of three stages along the main column and a cascade controller to regulate temperature at a stage in the main column manipulating temperature in a prefractionator stage. Controllers were designed using internal model control guidelines for traditional PI compensation. Feed composition disturbances were introduced in order to observe the response of the control system. The obtained results show that the control structure maintains the purity of the final products within acceptable ranges despite the existence of disturbance. Copyright © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.

Background. The aim of this study was to perform a systematic review of the literature on the efficacy of antimicrobial photodynamic therapy (PDTa) on cariogenic dental biofilm. Types of Studies Reviewed. Studies in vivo, in vitro, and in situ were included. Articles that did not address PDTa, those that did not involve cariogenic biofilm, those that used microorganisms in the plankton phase, and reviews were excluded. Data extraction and quality assessments were performed independently by two raters using a scale. Results. Two hundred forty articles were retrieved; only seventeen of them met the eligibility criteria and were analyzed in the present review. Considerable variability was found regarding the methodologies and application protocols for antimicrobial PDTa. Two articles reported unfavorable results. Practical Implications. The present systematic review does not allow drawing any concrete conclusions regarding the efficacy of antimicrobial PDTa, although this method seems to be a promising option.

A double temperature-cascade control strategy for controlling distillate composition is proposed. The control structure is based on two secondary loops that are designed for tracking the temperature of one tray in the rectifying and stripping section by manipulation of the reflux rate and reboiler heat input, respectively. Simulation results show that when saturations are imposed on controller outputs (reflux rate and heat input) both cascade controllers can act in a switching-like scheme without interaction problems. It is also shown that an adequate setting of a saturation parameter allows a low energy regulation of distillate composition under disturbances in feed composition.

In children5 years of age, Streptococcus pneumoniae (SP) is, globally, the leading cause of vaccine-preventable death. Surveillance conducted in Bogotá, Colombia estimated incidence rates of invasive pneumococcal disease (IPD), clinical and chest radiograph-confirmed pneumonia (CXR+Pn); SP serotype distribution and antimicrobial susceptibility.This prospective population-based surveillance was conducted from 2006 to 2008 in children 28 days to36 months of age seeking care at SaludCoop centers. We determined incidence rates of IPD and pneumonia (clinical and CXR+Pn). Eligibility criteria included: temperature ≥39.0°C within 24h and/or clinical suspicion of IPD or pneumonia. Blood was obtained for culture in all children. Other sterile site specimens were obtained per routine practice.Of 8261 subjects enrolled, a total of 64 had invasive pneumococcal disease detected by isolation of SP from nonduplicative cultures (62) or detected solely by PCR and a clinical picture consistent with IPD (2). The overall IPD incidence rates for culture-positive only cases for children aged 28 days to36 months was 76.4/100,000 per year for years 1 and 2 combined. Age stratification found the highest rates in children 6-12 and 12 to24 months of age. IPD incidence rates were assessed for bacteremic pneumonia (54.2/100,000), bacteremia (17.2/100,000), meningitis (3.7/100,000), and sepsis (1.2/100,000). Most common serotypes causing IPD were: 14 (51.6%), 6B (9.7%), and 19F (9.7%). Coverage of IPD cases by pneumococcal conjugate vaccine (PCV) 7, PCV10, and PCV13 was 77.4%, 85.5%, and 91.9%, respectively. Twenty-eight isolates (45.2%) were penicillin-nonsusceptible; PCV7 covered 96.3% of these; PCV10 covered 96.3% and PCV13 covered 100%. The overall incidence of clinical pneumonia and CXR+Pn was 6276/100,000 and 2120/100,000, respectively.Pneumococcal disease and pneumonia burden is considerable in children in Bogotá, Colombia. Vaccination with pneumococcal conjugate vaccines has the potential to decrease this burden. Epidemiologic data are critical in assessing the potential impact of introduction of PCVs into national immunization schedules.

This paper studied the dynamics of civilian and military fatalities in the Iraq War during the 2003-2010 period. R/S-scaling analysis, a method to characterize fractality and memory effects in sequences, was used to estimate time variations in the correlations of daily fatalities. Together with concepts from complex social networks and systems theories, the dynamics of correlations (measured in terms of the so-called scaling Hurst exponent) provide a framework to describe the Iraq War evolution and to evaluate the effects of the major military and political events. In terms of changes in a correlations parameter, five regimes in the evolution of the war were identified. The first regime, occurring in the first months after the invasion, corresponds to a conventional confrontation. In the second regime occurred in the last months of 2004, the dynamics of civilian fatalities evolved toward uncorrelated behavior, indicating that the occurrence of daily fatalities was basically governed by random processes. This is in contrast to the dynamics of military fatalities that showed increased correlations. The second regime can be seen as the advent of a chaotic episode where the different insurgency groups acted within an erratic, poorly coordinated, manner. In the third regime that occurred in the first two 2005 quarters, correlations of civilian fatalities increased and converged into the correlations patterns of military fatalities, and this was interpreted as the surging of a well-organized, although non-centralized, insurgency structure. The fourth regime lasted from mid-2005 to the last 2007 months and showed an important correlation decrement for the military fatalities. This was related to the clash of two antagonist war structures, namely, the traditional centralized Coalition Army and a non-centralized insurgent army. Finally, the fifth regime, from mid-2007 to date, is characterized by stable fatality dynamics converging to uncorrelated behavior. It is apparent that this behavior is related to the start of the endgame to achieve stable economy and government. The concept of a scale-free network was used to describe the insurgency operations and the subsequent war and political events oriented to incorporate the former Baath Party member in the formation of a national Iraqi government. It is concluded that, given the availability of data (fatalities, economic activity, migration, etc.) in contemporary conflicts, the usage of mathematical methods and tools would provide further insights of the conflict evolution and, in this way, help to design better policies and strategies to reduce the adverse effects of violence on civilians.