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Las imágenes obtenidas por percepción remota a través de vehículos aéreos no tripulados proveen de información que incide en la administración del campo y da soporte a la toma de decisiones. El proceso de análisis de estas imágenes involucra diferentes fases, como la adquisición y el preprocesamiento de las mismas. Estos datos son la entrada para métodos de aprendizaje supervisado en la clasificación de imágenes. Ejemplo de estos son las redes neuronales que han marcado un cambio radical en el análisis de información aplicada a la agricultura. Como métodos supervisados de aprendizaje requieren de dos etapas principales para realizar su tarea: el entrenamiento y las pruebas. El desempeño de la red neuronal depende en gran medida de que tan bien se ha conformado las imágenes de entrada que la entrenan para aprender. El presente trabajo propone un método para el preprocesado de imágenes con el objetivo de integrar el conjunto de datos de entrada a una red neuronal artificial (RNA). El método aquí descrito tiene como sujeto de estudio cultivos de caña de azúcar, describe la adquisición de imágenes por medio de vehículos aéreos no tripulados (VANT), su procesamiento para la integración de ortoimágenes, la división en ventanas de menor dimensión y la segmentación de la clase de interés (caña de azúcar).

Resumen: La cirugía bariátrica es el tratamiento más efectivo para tratar la obesidad y sus comorbilidades, sin embargo, hay barreras que evitan que estas sean aceptadas de forma generalizada. Ante la creciente epidemia de obesidad, surge la necesidad de crear nuevos tratamientos menos invasivos, los cuales deben tener un amplio margen de seguridad y efectividad para condicionar pérdida de peso, al menos mayor que un tratamiento basado en dieta y ejercicio. Estos incluyen dispositivos que se colocan y retiran por endoscopía y se clasifican en: dispositivos ocupativos, procedimientos restrictivos o remodelantes de la anatomía, bypass endoluminal y remodelación duodenal. También se dispone de técnicas percutáneas y de cirugías «menos» invasivas.En general, los resultados obtenidos muestran mejoría en el metabolismo de la glucosa de los pacientes diabéticos y en cuanto a la pérdida de peso, aunque no superan a la cirugía bariátrica, se observan resultados que tienen mayor alcance si se comparan con el tratamiento conservador (dieta y ejercicio). La tasa de eventos adversos es baja. El uso clínico de una nueva tecnología debe practicarse dentro de un programa de manejo multidisciplinario que incluya soporte nutricional, psicológico, deportivo, y médico. Es de suma importancia reconocer que estas terapias no son creadas para sustituir a la cirugía bariátrica, sino para aumentar las opciones de tratamientos y generar mayor alcance e impacto en la población general. Este trabajo tiene por objeto una revisión actualizada de la literatura sobre tecnologías emergentes para el tratamiento de la obesidad. Abstract: Bariatric surgery is the most effective treatment for obesity and its comorbidities but there are barriers that prevent its general acceptance. The growing obesity epidemic has resulted in the need for the creation of new, less invasive treatments, with a wide margin of safety and effectiveness for conditioning weight loss, at least greater than that resulting from treatment based on diet and exercise. Emerging therapies include devices that are endoscopically placed and removed, classified as: space-occupying devices, restrictive or anatomic-remodeling procedures, endoluminal bypass, and duodenal mucosal resurfacing. Percutaneous techniques and less invasive surgeries are also included.In general, results have shown improvement in glucose metabolism in diabetic patients. With respect to weight loss, results do not surpass those of bariatric surgery, but are better than results with conservative treatment (diet and exercise) and have a low rate of adverse events. Clinical use of a new technique should be carried out within a multidisciplinary management program that includes nutritional, psychologic, physical activity, and medical support. It must be understood that novel therapies are not being created to substitute bariatric surgery, but rather to increase treatment options in the general population, with greater reach and impact. The aim of the present study was to provide an up-to-date literature review on emerging technologies for the treatment of obesity.

Background Clostridioides (Clostridium) difficile colonization is common among infants. Serological sequelae of infant C. difficile colonization are poorly understood. Methods In this prospective cohort study of healthy infants, stools serially collected between ages 1-2 and 9-12 months were tested for non-toxigenic and toxigenic C. difficile (TCD). Cultured isolates underwent whole-genome sequencing. Serum collected at 9–12 months underwent measurement of IgA, IgG, and IgM against TCD toxins A and B and neutralizing antibody (NAb) titers against toxin B. For comparison, antitoxin IgG and NAb were measured in cord blood from 50 mothers unrelated to study infants. Results Among 32 infants, 16 (50%) were colonized with TCD; 12 were first colonized >1 month before serology measurements. A variety of sequence types were identified, and there was evidence of putative in-home (enrolled siblings) and outpatient clinic transmission. Infants first colonized with TCD >1 month prior had significantly greater serum antitoxin IgA and IgG against toxins A (P = .02 for both) and B (P = .009 and .008, respectively) compared with non–TCD-colonized infants, and greater IgG compared with unrelated cord blood (P = .005). Five of 12 (42%) colonized infants had detectable NAb titers compared with zero non–TCD-colonized infants (P = .02). Breastfeeding was not associated with differences in serological measurements. Conclusions TCD colonization is associated with a humoral immune response against toxins A and B, with evidence of toxin B neutralization in vitro. The extent and duration of protection against CDI later in life afforded by natural C. difficile immunization events require further investigation.

Study question Is dydrogesterone (DYG) equivalent compared to cetrorelix with respect to clinical pregnancy rate, ongoing pregnancy rate and live birth rate in oocyte donation (OD) cycles? Summary answer DYG is comparable to cetrorelix in terms of clinical pregnancy, but higher rates of ongoing pregnancy and live birth were observed in the DYG group What is known already Progestin-primed ovarian stimulation (PPOS) is an ovarian stimulation regimen based on a freeze-all strategy using progestin as an alternative to GnRH analog for suppressing a premature LH surge. DYG is an oral progestin that has been studied in PPOS protocols. Published reports indicate that length of ovarian stimulation, dose of gonadotrophin needed and number of MII retrieved from PPOS cycles are comparable to short protocol of GnRH agonists during OD cycles. However, while some studies noted no differences in terms of live births, worse pregnancy rates have been reported in recipients of oocytes from PPOS cycles compared to GnRH antagonists. Study design, size, duration Prospective controlled study to assess the reproductive outcomes of OD recipients in which the donors were subjected to the DYG protocol (20mg/day) compared with those subjected to the short protocol with cetrorelix (0.25 mg/day) from Day 7 or since a leading follicle reached 14 mm. The OD cycles were triggered with triptoreline acetate and the trigger criterion was ≥3 follicles of diameter >18mm. Participants/materials, setting, methods 202 oocyte donors were included, 92 under DYG and 110 under cetrorelix. The study was performed in a private infertility center between January 2017 and December 2020. The main outcome included the rates of clinical pregnancy, ongoing pregnancy and live births. Secondary outcomes included the number of oocytes retrieved, number of MII, fertilization rate, length of stimulation and total gonadotropin dose. Differences were tested using a Student’s t-test or a Chi2 test, as appropriate. Main results and the role of chance Compared to antagonist cycles, cycles under DYG had fewer days of stimulation (9.9 ± 0.9 vs. 10.8 ± 1.1, p Limitations, reasons for caution These results should be evaluated with caution. The limitations of this study include the limited number of participants enrolled and the limited data on pregnancy outcomes. A randomized controlled trial is necessary to provide more evidence on the efficacy of the DYG protocol. Wider implications of the findings: The efficacy of PPOS protocol compared to GnRH-antagonist protocol in terms of reproductive outcomes has been little studied. PPOS using DYG yields comparable clinical pregnancy rates compared to cetrorelix in OD cycles. The differences found regarding the rates of ongoing pregnancy and live births should be further investigated. Trial registration number Not applicable

Summary In this paper, a novel discontinuous control strategy for robust stabilization of a class of uncertain multivariable linear time-delay systems with delays in both the state and control variables is proposed. Two predictors are first designed to compensate the delay effect in the control input, and then an integral sliding mode control technique is applied to compensate partially the effect of the perturbation term. Finally, a nominal delay-free component of the full control input is designed to stabilize the sliding mode dynamics. Conditions for the stability of the closed-loop perturbed system are then derived. The proposed framework is then extended to the class of systems modeled in regular form. Some examples illustrate the feasibility of the proposed scheme. Copyright © 2017 John Wiley & Sons, Ltd.

Background & Aim The establishment of human keratinocytes’ culture (KTs) to obtain human Tissue Engineered Skin Substitutes is under research nowadays. Best results have been achieved culturing KTs on a feeder layer of irradiated 3T3 murine fibroblasts (i3T3s). Nevertheless, molecular effects of murine cells on KTs is unknown and for this reason, irradiated human fibroblasts (iHFs) have been studied. The objective of this study is to evaluate the effect of different irradiation doses on cell reducing power and cell proliferation of both fibroblasts. Methods, Results & Conclusion Methods 3T3s were obtained from a commercial vial of 3T3-Swiss Albino. HFs were isolated from human skin biopsies. After culturing and final recovery, both cell types were irradiated to doses of 50 and 100 Gy to constitute the feeder. Non-irradiated cells were used as control. Each condition was cultured 15 days in two 24-well plates (2 cm2/well). In each plate, cell densities cultured in triplicate were: 7,500 cells/cm2 and 10,000 cells/cm2. One plate was used for reducing power analysis; using a dilution of PrestoBlue™ (10%). The other plate was used for cell proliferation analysis; using Trypan Blue solution. N for each plate was 3 and a value of p Results Analysis of each type of feeder (Figs. 1-2) revealed significant differences at Days 10 and 15, between both irradiation doses and non-irradiated cells. In the case of iHFs, irradiation dose had a significant effect on cell reducing power, mainly at Day 15. Analysis of i3T3s revealed that the effect of irradiation on reducing power was extremely significant from Day 3 to 15, but no dose-dependent. A comparative analysis (Fig. 3) indicated that the number of non-irradiated cells after 15 days was higher in the case of 3T3s than HFs (644,620 cells vs 143,740 cells), but cell reducing power was lower in the case of murine fibroblasts (72.33% vs 80.67%). In the case of irradiated cells, iHFs were more resistant to irradiation in both, cell reducing power (27.5% vs 4.92%) and cell proliferation (5,962 cells vs 1,351 cells) at Day 15. Conclusion No differences exist considering initial cell density or irradiation dose in both feeders. Comparative analysis revealed that irradiation process is more effective in 3T3s than in HFs. This study needs to be completed with the incorporation of KTs on the different feeder conditions analyzed. Supported by PI17/02083, SAS PI-0458-2016 and PhD fellowship FI18/00269–Alvaro Sierra-Sanchez).

As part of the energy sustainability program intended to reduce the carbon footprint of the National Polytechnic Institute, solar photovoltaic electricity generation systems along with electricity consumption reduction actions have been implemented in three entities. These actions were implemented in accordance with recommendations defined by environmental committees and considering the diagnoses of baseline energy consumption. This work reports the quantification of the savings generated by the implementation of operational measures of technological substitution and solar photovoltaic electric power generation. The foregoing includes a process of identification of the baseline of electricity consumption, the replacement of infrastructure and equipment of high energy consumption with equipment of low consumption and environmental impact, as well as the installation of technology for the generation of electrical energy by renewable sources. Three solar photovoltaic systems were installed, replacement of luminaires, replacement of hand dryers and replacement of obsolete air conditioning equipment. It was found that on average the reduction in monthly electricity consumption is 31% with the consequent economic savings. Regarding the reduction of the carbon footprint, an impact on non-generation of tonnes of CO2 equivalent amount 37% quantified with reference to the generation before the implementation of the operational and power generation measures. This is equivalent to not having generated 18.31 tCO2e per month. This work describes the activities carried out and the methodology used to calculate the savings found, both in energy consumption, economic, and in reducing the carbon footprint.

Background & Aim The aim of this study was evaluated the epidermal barrier function in an artificial bioengineered skin substitutes (ABSS) based on hyaluronic acid biomaterial. The study was performed evaluating specific skin ointments at different test period. Methods, Results & Conclusion Dermal fibroblasts (DF) and Keratinocytes (KT) were enzymatically isolated from 9 cm2 skin biopsies. After 4-5 weeks in culture, DF were part of dermal fibrin-hyaluronic acid stroma. KT (obtained using feeder-free method) were seeded on the surface to establish ABSS. Flow cytometry assay was carried out to phenotypically evaluate of keratinocytes: CD49f (integrin α6) and CD90 (fibroblast cell surface marker). Cell viability (LIVE/DEAD® assay), structural integrity (histological evaluation) and epidermal barrier function (transepidermal water loss, TEWL: Tewameter®) were measured after 5, 15 and 30 minutes to apply beclomethasone, mupirocin and vaseline. Acellular ABSS were used as controls. Specific cell culture parameters were evaluated after final recovery of keratinocytes. The cell expansion rate was significantly higher (p≤0.001%) with the CNT-57S media were supplemented with human platelet lysate. CD49f percentage was higher in keratinocytes with CNT-57S (95.2%). The CD90 percentage was lower in keratinocytes expanded with CNT-57S human lysate supplemented (1.60%). A viability assay was carried out in ABSS at first (85.1%) and second week (87.8%). Finally, barrier function evaluation of ABSS was carried out by measuring TEWL in the first and in the second week of maintenance. TEWL values in acellular ABSS were higher than in cellular ABSS, although the difference was not significant. Cells improved ABSS barrier function, thus favouring the reduction of water loss. Regarding the evaluation period, significant differences of TEWL were observed, decreasing the values in the second week. This may be due to the growth of the epithelial layer in cellular ABSS, which contributes to improvement of the barrier function. TEWL measures also decreased over the measurement time, although the differences were not significant. No difference was observed with respect to the type of ointment. In conclusion, keratinocytes culture was optimized using animal component-free and feeder-free method. A novel way to evaluate keratinocytes contribution to epidermal barrier function has been development in vitro.

Objetivo: Verificar o efeito de 30 sessões do Método Pilates na postura corporal estática no plano sagital e na flexibilidade da cadeia muscular posterior de mulheres adultas. Método: 10 mulheres foram submetidas a 30 sessões de Mat Pilates, ministradas por profissional capacitado, três vezes na semana por 50 minutos. Foram avaliados, pré e pós-intervenção, a flexibilidade da cadeia muscular posterior por meio do banco de Wells, e a postura corporal estática no plano sagital (equilíbrio ântero-posterior do tronco, posição da cabeça, da pelve - inclinação e pulsão -, e dos joelhos), por meio do protocolo e software DIPA. A análise estatística, descritiva e inferencial, foi realizada no software SPSS v. 20.0. A normalidade dos dados escalares foi verificada pelo teste de Shapiro- Wilk, sendo realizados, para comparação do fator tempo, testes t de amostra em pares e de Wilcoxon, para os dados com distribuição normal e não normal, respectivamente, onde α0.05). Conclusão: 30 sessões de Mat Pilates promoveram melhora na flexibilidade da cadeia muscular posterior, contudo, não foram suficientes para surtir mudanças significativas na postura corporal estática no plano sagital. Objective: To verify the effect of 30 sessions of the Pilates Method on the body static posture in the sagittal plane and on the flexibility of the posterior muscular chain of adult women. Method: 10 women underwent 30 sessions of Mat Pilates, taught by a trained professional, three times a week for 50 minutes. The flexibility of the posterior muscular chain through Wells’ bench, and the body static posture in the sagittal plane (anteroposterior trunk balance and the position of the head, pelvis - tilt and drive - and knees) through protocol and software DIPA were assessed pre and post intervention. Statistical analysis, descriptive and inferential, was performed in SPSS v. 20.0. The normality of the scalar data was verified by the Shapiro-Wilk test, being conducted for comparison of the time factor, paired sample t-test and Wilcoxon test for data with normal and non-normal distribution, respectively, where α0.05). Conclusion: 30 sessions of Mat Pilates promoted improvement in the flexibility of the posterior muscle chain, however, were not enough to make significant changes in the static body posture in the sagittal plane. Objetivo: Verificar el efecto de 30 sesiones de Método Pilates en la postura corporal estática en el plano sagital y en la flexibilidad de la cadena muscular posterior en mujeres adultas. Método: 10 mujeres realizaron 30 sesiones de Mat Pilates, impartidas por un profesional capacitado, tres veces a la semana durante 50 minutos. Fueron evaluadas antes y después de la intervención, la flexibilidad de la cadena muscular posterior a través del banco de Wells, y la postura corporal estática en el plano sagital (equilibrio anteroposterior del tronco, posición de la cabeza, de la pelvis – inclinación y pulsión - y de las rodillas), por medio de software y protocolo DIPA. Las estadísticas, análisis descriptivo e inferencial se realizó con el software SPSS v. 20.0. La normalidad de los datos escalares se verificó mediante el test de Shapiro-Wilk, siendo realizados, para la comparación del factor tiempo, test t de muestras pareadas y de Wilcoxon, para datos con distribución normal y no normal, respectivamente, donde α0.05). Conclusión: 30 sesiones de Mat Pilates fomentaron la mejora de la flexibilidad de la cadena muscular posterior, aunque no fueron suficientes para surtir cambios significativos en la postura corporal estática en el plano sagital.

Background Although pediatric Clostridium difficile infections (CDIs) are increasing, C. difficile transmission patterns among children are poorly understood. Methods We performed whole genome sequencing (WGS) on C. difficile isolates collected from children diagnosed with CDI between December 2012 and December 2013 at a single academic medical center. Genome sequences of isolates from CDIs diagnosed ≥8 weeks after study initiation were compared to all study isolate genome sequences. Among patients with isogenic isolates (≤2-3 core genome single nucleotide variants [SNVs] identified by pairwise SNV analyses), common inpatient and/or outpatient healthcare exposures were investigated. Results Among 131 CDIs in 107 children, WGS identified 104 genetically distinct isolates. Of 84 incident CDIs occurring ≥8 weeks after study initiation, only 10 (11.9%) were caused by a strain isogenic to another cohort CDI isolate (putative transmission events). Proportions of each CDI class putatively associated with transmission were hospital-onset healthcare facility-associated (HCFA), 2/16 (12.5%); community-onset HCFA, 1/17 (5.9%); indeterminate, 1/11 (9.1%); community-associated (CA), 5/40 (12.5%); and recurrent, 1/21 (4.8%). Transmission events among CA and HCFA CDIs were similarly infrequent (5/40 [12.5%] vs 3/33 [9.1%]; P = .64). Shared healthcare facility exposures were only identified among 7/10 putative transmission events. Potential community transmission (same postal code) was not identified. Conclusions WGS identified a highly diverse group of C. difficile isolates among children with CDI, including those with HCFA CDI. Clostridium difficile transmission among symptomatic children was very uncommon. Among putatively transmitted cases, investigation of shared healthcare exposures often did not identify a potential transmission source.

We report here the complete genome sequence of Clostridioides difficile strain DH/NAP11/106/ST-42, which is now the most common strain causing C. difficile infection among U.S. adults. This strain was isolated from the stool from a hospitalized pediatric patient with frequent relapses of C. difficile infection.

Background Infant C. difficile colonization is common, but the molecular epidemiology and immunologic consequences of colonization are poorly understood. Methods In this prospective cohort study of healthy infants, serial stools collected between 1–2 and 9–12 month olds were tested for glutamate dehydrogenase (detects nontoxigenic or toxigenic C. difficile [TCD]), tcdB PCR (detects TCD), and cultured for C. difficile. Isolates underwent whole genome sequencing and multilocus sequence typing (MLST). Clonal strains were identified by single nucleotide variant (SNV) analysis. TCD was confirmed by BLAST identification of tcdA/tcdB. Serum collected at 9–12 month olds underwent ELISA for measurement of IgA, IgG, and IgM against TCD toxins A and B. For comparison, anti-toxin IgG was measured in cord blood of 50 consecutive full-term deliveries (unrelated to study infants). Arbitrary ELISA units were compared by Wilcoxon rank-sum test. Results Among 32 infants, 16 (50%) had at least one TCD+ stool, 12 of whom were colonized at least 1 m prior to serology measurements (Figures 1 and 2). A variety of STs were identified, and evidence of putative in-home (enrolled siblings) and outpatient clinic transmission was identified (Figure 3). Infants with TCD colonization had significantly greater levels of anti-toxin IgA and IgG compared with non-colonized infants and IgG compared with unrelated cord blood (Table 1). Conclusion Infant C. difficile colonization is a dynamic process with variable strain types and duration. Outpatient clinics may be a C. difficile reservoir for some patients. TCD colonization is associated with a humoral immune response against toxins A and B, but whether natural TCD immunization protects against CDI later in life requires further investigation. Disclosures L. Kociolek, Alere/Techlab: Investigator, Research support. C. P. Kelly, Actelion: Consultant, Consulting fee. Artugen: Consultant, Consulting fee. Facile: Consultant, Consulting fee. GSK: Consultant, Consulting fee. MSD: Consultant, Consulting fee. Seres: Consultant, Consulting fee. Summit: Consultant, Consulting fee. Vedanta: Consultant, Consulting fee. D. N. Gerding, Merck: Scientific Advisor, Consulting fee. Actelion: Scientific Advisor, Consulting fee. DaVolterra: Scientific Advisor, Consulting fee. Summit: Scientific Advisor, Consulting fee. Rebiotix: Medical Officer and Scientific Advisor, Consulting fee. Pfizer: Consultant, Consulting fee. MGB Pharma: Consultant, Consulting fee. sanofi pasteur: Consultant, Consulting fee. Seres: Investigator, Research grant. CDC: Investigator, Research grant. US Dept VA: Investigator, Research grant. Treatment/Prevention of C. difficile: Patent Holder, no license or royalties.

Background Clostridium difficile colonization is common in children. PCR does not distinguish infection (CDI) from colonization. Toxin enzyme immunoassay (EIA) and PCR cycle threshold (Ct) may predict CDI in PCR+ adults, but assay performance in children is poorly understood. Methods Stools from children aged 2–21 years with laboratory-identified (labID) CDI (tcdB PCR+; GeneXpert) underwent: toxin EIA (QUIK CHEK Complete [QCC] and Immunocard [IC]); cell culture cytotoxicity neutralization assay (CCCNA); and C. difficile stool culture (Cx). Children were determined to have clinical CDI (cCDI) by chart review and/or parent communication if all were noted: at least three unformed stools (Bristol type 5–7) in 24 hours; response to CDI treatment within 5 days; and no other likely diarrheal etiology. EIA and PCR Ct performance were measured for various reference standards (RefStd) based on stool assay results and/or cCDI classification. Results A total of 253 PCR+ stools were included. All stools underwent QCC; 218 (86%) were quantity sufficient for IC. Discordant EIA results occurred in 19/218 (8.7%) stools. Table 1 lists EIA sensitivity (Sn), EIA specificity (Sp), and median PCR Ct for each RefStd. Figure 1 shows the receiver operating characteristic (ROC) curve for PCR Ct to identify PCR+/CCCNA+/cCDI+ children (area under curve = 0.76). The difference between sensitivity (71%) and specificity (72%) was minimized at Ct < 23.5. Conclusion Only a minority of PCR+ children meets strict clinical and laboratory CDI criteria. More stringent CDI definitions are associated with increasing toxin EIA Sn and lower PCR Ct (i.e., greater stool C. difficile inoculum). However, both toxin EIA and PCR Ct perform suboptimally as stand-alone tests to distinguish CDI from colonization in PCR+ children. Disclosures L. Kociolek, Alere/Techlab: Investigator, Research support.

We read with interest the article by Vigarios et al.1 describing eight patients treated with a variety of BRAF inhibitors who developed asymptomatic hyperkeratotic oral mucosal lesions. These were frequently multifocal and presented following a mean onset of three months of treatment with a BRAF inhibitor. In one patient, one such lesion rapidly developed into oral squamous cell carcinoma requiring excision. We would like to highlight delayed oral toxicity in a long-term responder to a BRAF inhibitor.

This paper proposes the simulation and verification of coverage and electromagnetic compatibility (EMC) for the implementation of digital television transmitters in Quito city. To analyze and simulate uses SIRENET like electronic tool and compares the results obtained for the simulation with field tests conducted to digital television. The digital TV service provider in this work was ECTV. The purpose of this research is to identify the coverage area and determine the location of sectors which could be put relay stations, should it be required; this aims to ensure the transmission of television in digital form, according to the new standard adopted in Ecuador including Quito, (ISDB-Tb). Additionally, based on the study of electromagnetic compatibility, the effect on transmission / reception when transmission technology digital and analog simultaneously present is described.

Trapping efficiency (TE) is defined as the percent of particles that are retained within an impoundment. TE can vary from ⩽0% indicating no sediment is retained or is lost, to 100% where all the sediment is retained. In this paper a high quality, long-term data set (32 years) was used to demonstrate that annual sediment trap efficiencies for a run of the river impoundment are variable. For water years 1973–2005, annual trap efficiencies for Coralville Reservoir ranged from 5.6 to 95.8%, with a mean of 74.7% and a median of 79.9%. Overall trap efficiency for the entire period was determined to be 80.3% and a detention time of 12.4 days . A comparison of the observed long-term TE was done against different empirical TE equations that are commonly used (Brown, Brune, Churchill, Dendy, Heinemann, & USDA/Summit Co., Water District). The Churchill equation provided the best fit of the empirical trap efficiency equations ( TEC =79.1%) ; all other empirical TE relationships underestimated the observed trap effici...

In this paper, a new discontinuous control strategy is proposed for robust stabilization of a class of uncertain multivariable linear time-delay system with delays in both the state and control variables. The integral sliding mode control technique is applied to compensate the uncertainty term and then a predictor is used to obtain free-delay closed-loop system with desired spectra. For systems presented in Block Controllable (BC) form with delay, a block dead time compensation algorithm which gives a sliding manifold is derived. An example of the application of the proposed control strategy is presented.

Research on teaching listening and speaking skills has been conducted at many levels. The purpose of this study was to analyze the current implementation of classroom and extracurricular activities, as well as the use of educational resources for teaching both skills in public senior high schools in the Amazon region of Ecuador, particularly in the towns of Zamora and Yantzaza. The participants included 188 students between the ages of 15 and 18 years, and 10 English teachers in the area. This study was conducted using a mixed-method (quantitative and qualitative) approach. The instruments to collect information were students’ and teachers’ questionnaires, teacher’s interviews, and observation sheets. In addition, the Cambridge English Unlimited Placement Test was applied in order to determine the students’ English proficiency level of listening and speaking skills. The findings revealed that the completion of exercises based on a listening passage and dialogues were the most frequent activities used by students to practice listening in the classroom; meanwhile, dialogues and repetition drills were the most frequent activities applied to develop speaking. With respect to extracurricular activities, listening to English music with lyrics, watching videos, discussions, and conversations with native speakers were most frequently suggested for enhancing listening and speaking. Among the resources, audio CDs and textbooks were the most frequent aids to prompt listening and speaking activities.

This paper presents a structurally stable scheme for nonlinear systems which do not satisfy the so-called FIB conditions for the existence of a linear solution to the structurally stable regulator solution, namely, the case when some necessary detectability condition with respect to the original system’s output does not hold. Under certain additional conditions, it is shown that the proposed scheme guarantees zero output tracking error between the actual output and the desired reference signal, in spite of the presence of parameter variations. Application to the model of a rotary inverted pendulum shows the effectiveness of the proposed scheme.

This paper applies the block control method to form a decomposed control law suitabal for multivariable linear time-delay systems. A block controllable form is introduced and a non-singular transformation that reduces the system to this form, is proposed. A block deadtime compensation algorithm wich gives a sliding manifold, is derived. An example of the application of the proposed control strategy is illustrated.

Tumors of endothelial cell origin are relatively common. Soft tissue tumors and numerous subtypes of benign and malignant vascular tumors have been described; the histogenesis of many of these tumors is uncertain, and distinguishing between benign and malignant vascular tumors, some of which express lymphatic endothelial cell markers, can be problematic. In the present study, immunophenotypic expression of a novel hyaluronan receptor (LYVE-1), which is expressed by endothelial cells of normal lymphatic vessels but not blood vessels, was determined in benign and malignant vascular tumors. It was found that, except in lymphangiomas, intramuscular hemangiomas, and Masson's hemangiomas, endothelial cells in benign blood vessel tumors (including capillary and cavernous hemangiomas, glomus tumors, pyogenic granulomas, and epithelioid hemangiomas) were negative for LYVE-1, and that all angiosarcomas and Kaposi's sarcomas were positive for LYVE-1. Expression of LYVE-1 and other lymphatic endothelial cell markers in relatively few vascular neoplasms has implications for the histogenesis of these lesions, and may prove useful in distinguishing angiosarcoma and Kaposi's sarcoma from most common benign vascular tumors.

Objective: To determine the clinical and laboratory features, malignancy, outcome and their association in a Hispanic mestizo population with Inflammatory Idiopathic Myopathies (IIM). Material and methods: The medical records of Hispanic mestizo patients with dermatomyositis, polymyositis or overlap syndrome from a single center were reviewed. Several variables were studied with emphasis on malignancy. Results: We report the clinical and laboratorial features of 118 patients with IIM; the female to male ratio was 2.3:1. Elevated CK, proximal weakness, compatible biopsy and elevated LDH were the most frequent findings. Malignancy was found in 9,3%, gynecological tumors were the most common (55%). Mortality was 10.2%, mainly related to infections and respiratory failure. Conclusions: The overall rate of malignancy in this large series of patients with IIM was 9.3%. The majority of our patients reached a good outcome. No risk factors for malignancy were found.

This paper combines the block control and sliding mode control techniques to design a discontinuous regulator for a class of nonlinear systems presented in so-called Nonlinear Block Controllable Form with matched and unmatched uncertainties. The Sliding Mode Regulation Problem is formulated, and the existence solution conditions are derived.

In this paper the use of a liquid homogeneous catalyst has been studied in reactivity vacuum residues by hydroconversion under different conditions. To cover a wide range of compositions, six (6) vacuum residues were selected from crude mixtures. Hydroconversion test were performed in batch reactor with hydrogen atmosphere at about 2000psi in a temperature range between 430 and 480°C. The results allowed to establish that the reactivity hydroconversion conditions about coke formation is higher in vacuum residues with higher content of resins and asphaltenes. The reaction conditions promote distillate formation, however, with increasing stringency conditions, the distillate yield decreases due to distillate transformation into temperature range 430 and 460°C compared to the tests performed without catalyst demonstrating that the use of homogeneous catalyst is an alternative to treating vacuum residues and results are satisfactory in the conversion processes. Finally, predictive expressions have been developed in the formation of products depending on the conditions of temperature and physicochemical properties of processed vacuum residue.

Analogously to the formulation of the so-called classical servomechanism problem, the problem of tracking a reference signal while rejecting the effect of a disturbance signal by means of the VSS technique is studied by formulating the sliding mode servomechanism problem for which conditions for the existence of a solution for in general case and for a classes of nonlinear system presented in the Regular Form or in the Nonlinear Block Controllable Form are derived. The effectiveness of the proposed method is demonstrated by the application to the Pendubot system.