Patients without colonoscopic follow-up after abnormal fecal immunochemical tests are often unaware of the abnormal result and report several barriers to colonoscopy.

BackgroundThe fecal immunochemical test (FIT) is the second most commonly used colorectal cancer (CRC) screening modality in the United States; yet, follow-up of abnormal FIT results with diagnostic colonoscopy is underutilized. Our objective was to determine patient-reported barriers to diagnostic colonoscopy following abnormal FIT in an academic healthcare setting.MethodsWe included patients age 50-75 with an abnormal FIT result between 1/1/2015 and 10/31/2017 and no documented follow-up diagnostic colonoscopy. We abstracted demographic data from the electronic health record (EHR). Study personnel conducted telephone surveys with patients to confirm colonoscopy completion and elicit data on notification of FIT results and barriers to colonoscopy. We also provided brief verbal education about diagnostic colonoscopy. We calculated frequencies of demographic data and survey responses and compared survey responses by interest in colonoscopy after education.ResultsWe surveyed 67 patients. Fifty-one were aware of the abnormal FIT result, and a majority learned of the abnormal FIT result by direct communication with providers (19, 37.3%) or EHR messaging (11, 21.6%). Overall, fifty-three patients (79.1%) confirmed lack of colonoscopy, citing provider-related (19, 35.8%), patient-related (16, 30.2%), system-related (1, 1.9%), or multifactorial (17, 32.1%) reasons. Lack of knowledge of FIT result (14, 26.4%) was most common. After brief education, 20 (37.7%) patients requested colonoscopy.ConclusionPatients with an abnormal FIT reported various multi-level barriers to diagnostic colonoscopy after abnormal FIT, including knowledge of FIT results. When provided with brief education, participants expressed interest in diagnostic colonoscopy. Future efforts will evaluate interventions to improve colonoscopy follow-up

Toma de decisiones estratégicas soportadas por un modelo de optimización que integra la manufactura y distribución en una compañía química global

A medida que las organizaciones crecen, las cadenas de suministro lo hacen también en complejidad, lo cual plantea un reto importante que representa al mismo tiempo oportunidades de mejora que pueden tornarse en ventajas competitivas; por ello surge la necesidad de tomar mejores decisiones a un nivel estratégico tales como la definición de en dónde producir materiales y desde dónde distribuir a los clientes, de tal manera que los beneficios se maximicen. Este problema es conocido como el de rediseño de una red logística. En esta ponencia se presenta un problema de este tipo donde se busca mejorar la utilidad bruta de una compañía química global en cinco plantas y ocho centro de distribución de la región latinoamericana.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Application of Linear Programming for the Timetabling Model in Technical Education Institution in Mexico

Diverse scheduling problems in education such as planning of lectures’ or exams’ timetables are among the most recurrent problems each begging of an academic period. Therefore, these areas have been gaining interest, the planning of the schedules of professors or exams for a set of groups and courses. The timetabling problem involves scheduling a number of resources, each consisting of class of students, a teacher, a subject and a room, to a fixed number of time slots. The problem of school timetabling is addressed for an institution of technical education, analyzing three groups of one specialty among those offered by the institution. A mathematical programming model using branch and bound technique was designed to solve the timetable problem for a Mexican Institution. The solutions obtained by this approximation were implemented in the 2013 - 2014 academic period. The proposed approach has proved very good results by helping the decision makers in the institution to solve the planning of courses at the beginning of the academic period.Un problema recurrente en cada inicio de periodo escolar en las Instituciones Educativas (IEs) es la calendarización de horarios de los profesores para un conjunto de grupos y cursos. En este trabajo se pretende optimizar la asignación de cursos a grupos en un conjunto de periodos de tiempo con determinados requerimientos. Se aborda este problema dentro de un plantel de educación técnica media, en el cual se analizan tres grupos de la especialidad de Laboratorista químico ofertada por la institución. Se diseñó un modelo de programación matemática que fue resuelto mediante la técnica de ramificación y acotamiento disponible en un software comercial de optimización llamado LINGO® 10. Este caso real fue implementado en el ciclo 2013 – 2014 y validado con éxito al resolver en 4 segundos las actividades que realizarán los empleados dentro de una franja horaria de entre 5 a 7 horas. El enfoque planteado contribuye a agilizar la toma de decisiones del centro escolar al inicio del ciclo académico

GESTIÓN DE POLÍTICAS DE INVENTARIO EN EL ALMACENAMIENTO DE MATERIALES DE ACERO PARA LA CONSTRUCCIÓN

El control de inventarios es de vital importancia, por el monto de la inversión que representa y por el grado de dificultad que implica una administración financiera efectiva, para no incurrir en altos costos de almacenamiento. Este artículo presenta el uso del modelo de lote económico de pedido (Economic Order Quantity –EOQ) y el modelo de revisión continua con demanda incierta y con desviación estándar (q, R) para establecer políticas de inventarios en la demanda de materiales de acero para la construcción, comercializados en una empresa de aceros tomando en cuenta la variabilidad de la demanda y los tiempos de suministro de la aplicación de los modelos, quedan establecidas las cantidades optimas a ordenar de los materiales con respecto al tiempo de duración del ciclo de pedido, generando un ahorro del 30 % en los costos logísticos totales e incrementando el nivel de servicio de un 69% a un 90,4%. El empleo de los modelos propuestos brinda el soporte a las decisiones que han de tomarse en los niveles de inventario de los materiales, minimizando los costos logísticos totales y mejorando la calidad de servicio al cliente.The control of inventories is of vital importance, for the amount of investment it represents and for the degree of difficulty involved in effective financial management, so as not to incur high storage costs. This article presents the use of the economic order lot model (Economic Order Quantity –EOQ) and the continuous review model with uncertain demand and with standard deviation (q, R) to establish inventory policies in the demand for steel materials for construction marketed in a steel company taking into account the variability of demand and supply times. From the application of the models, the optimal quantities to the order of the materials are established with respect to the duration of the order cycle, generating a 30% savings in total logistics costs and increasing the level of service from 69% to 90,4%. The use of the proposed models provides support to the decisions that have to be taken in the inventory levels of the materials minimizing the total logistics costs and improving the quality of customer service.&nbsp

Análisis de series de tiempo en el pronóstico de la demanda de almacenamiento de productos perecederos

Los pronósticos son una herramienta que proporciona un estimado cuantitativo de la probabilidad de eventos futuros. La relevancia de incorporar pronósticos en la demanda de almacenamiento en productos perecederos dentro de la cadena de frio deriva de su importancia económica y social. Este caso de estudio presenta una empresa con tendencia de crecimiento dedicada al almacenamiento de productos perecederos e incorpora técnicas de pronósticos de series de tiempo, en el volumen de ingreso y egreso de los productos en una cámara frigorífica, con el fin de estimar el volumen de almacenamiento para prever los requerimientos de instalaciones adicionales, personal y materiales necesarios para la movilidad de los productos

Three-axes rotation algorithm for the relaxed 3L-CVRP

The purpose of this work is to present a developed three-axes rotation algorithm to improve the solving methodology for the relaxed 3L-CVRP (Three-Dimensional Capacitated Vehicle Routing Problem). Although there are reported works on solving approaches for the relaxed 3L-CVRP that consider product rotation to optimize load capacity, rotation on the three axes has not been thoroughly studied. In this aspect, the present work explicitly explores the three-axes rotation and its impact on load capacity optimization. In order to improve the relaxed 3L-CVRP problem, a two-phase solution was developed. The first phase consists of finding the solution for the CVRP problem, using a demand previously obtained with a heuristic developed to convert the 3L-CVRP demand into CVRP demand. The second phase is to obtain the loading of the vehicle using a heuristic developed to load the items using rules to obtain the rotation of the items. The proposed approach was able to improve the load assignment in 48.1% of well-known 3L-CVRP instances when compared to similar approaches on the relaxed 3L-CVRP. The outcomes of this research can be applied to transportation problems where package rotation on the z-axis is an option, and there are not fragile items to load in the vehicles

FACILITY LOCATION MODEL WITH INVENTORY TRANSPORTATION AND MANAGEMENT COSTS

This work is focused on the integration of the standard EOQ (Economic Order Quantity) model within the facility location decision model. This is proposed to extend on the facility location task which is usually performed based on just the overall demand of the customer locations to be served. If the inventory costs are considered within the demand supply process, these may affect the overall transportation costs as these are not linearly dependent of the demand. As such, the extended model considers, besides the distances, performance and capacity of the vehicles, the order quantities and the period in which they should be fulfilled. This model was tested with a reference instance of 200 suppliers and one distribution centre. The distances were estimated by considering the geographical locations of all elements in the network and the spherical model of the Earth’s surface to obtain the metric in kilometres. As analysed, by considering the inventory costs within the facility location model, it can lead to refine the location to obtain long-term savings in transportation

Recent Biomarkers for Monitoring the Systemic Fluoride Levels in Exposed Populations: A Systematic Review

Fluorides are compounds that can be found in the minerals of soil with volcanic rocks. Different populations are exposed to high levels of fluorides through drinking water that, due to their chronic intake, cause several types of damage to health. Nails and hair, denominated as recent biomarkers, have been employed for monitoring systemic fluoride from long-term exposure to fluorides. The aim of this study was to perform a systematic review of the use of recent biomarkers for monitoring systemic fluoride levels in exposed populations and verify their validity in hemeasurement of the fluorine (F−) concentration within the body. A digital search was performed in the databases PubMed/Medline, Springer Link, Cochrane, and Scopus of original articles that employed recent biomarkers for monitoring systemic F−. Seventeen articles were included in this analysis; the recorded variables were the F− amount in each assessed biomarker, source of exposure ,and total daily fluoride intake (TDFI). TDFI was associated with F− in nails and hair, as well asthe exposure through drinking water. In conclusion, recent biomarkers are adequate for monitoring the systemic fluoride levels by evaluating the chronic/subchronic exposure through different sources, mainly drinking water, considering nails better than hair for this purpo

Modeling the Hidden Risk of Polyethylene Contaminants within the Supply Chain

Inventory management is very important to support the supply chain of the manufacturing and service industries. All inventories involve warehousing; however, most of the products and packages are associated to plastic which is the main generator of polyethylene (phthalate) pollution in the air and water resources. In fact, phthalate has been identified as the cause of serious health conditions and its impact within the operation of logistic processes has not been studied. In this work, we perform research on the generation of phthalate as the control on these emissions is important to adjust the supply strategy to reduce the human risk exposure and contamination of the environment. For this purpose, generation of phthalate is modeled through the use of artificial neural networks (ANNs) and its impact on the supply strategy is assessed through its integration within a stochastic inventory control model. As presented, it is possible to adjust the supply strategy to reduce the cumulative generation of phthalate within the warehouse and thus reduce its impact on human health and environment sustainability

Cadena de suministro de productos agrícolas de traspatio

Objective: This study aims to analyze the backyard agricultural production system with a logistical focus, assuming that the knowledge of the links that make up the supply chain will contribute to developing productive and operational strategies that link backyard producers with short agro-food chains. Design/methodology/approach: The case study of the highly marginalized localities and indigenous presence of the municipalities of Chontla and Tempoal, Veracruz is presented. The supply chain of backyard agricultural products was analyzed from a generic model identifying the products, furthermore making an annualized economic projection. The information was collected with opportunity sampling through surveys of backyard producers, intermediaries, retail and wholesale marketers, municipal agents, and local authorities. Results: Five echelons define the backyard agricultural products supply chain of the case study: raw materials production, processing, manufacturing, product presentation, and the final consumer. It has a semi-structured marketing scheme between traditional and short commercialization circuits. Four opportunity areas were identified: non-standardized product processing, inappropriate storage conditions, production records absence, and poor distribution and marketing channels. Limitations on study/implications: The annualized economic projection indicated that 35.8% of the products are destined for self-consumption, 21.2% are commercialized in local and municipal markets, and 43% of the production is not commercialized. Findings/conclusions: This study proposes to locate strategically (in each municipality) collection, and distribution centers for backyard agricultural products to reduce the amount of non-commercialized products and link backyard agricultural producers in short agri-food chains and thereby contribute to strengthening the local economy.Objetivo: Estudiar el sistema de producción agrícola de traspatio con un enfoque logístico, asumiendo que el conocimiento de los eslabones que componen la cadena de suministro contribuirá a desarrollar estrategias productivas y operacionales que vinculen a los productores con cadenas agroalimentarias cortas. Diseño/metodología/aproximación: Se presenta el caso de estudio de las localidades de alta marginación y presencia indígena de los municipios de Chontla y Tempoal, Veracruz. Se analizó la cadena de productos agrícolas de traspatio a partir de un modelo genérico identificando los productos del caso de estudio y realizando una proyección económica anualizada. La información se recolectó con muestreo de oportunidad mediante encuestas a productores de traspatio, intermediarios, comercializadores minoristas y mayoristas, agentes municipales y autoridades locales. Resultados: La cadena de suministro de productos agrícolas de traspatio está definida por cinco eslabones: producción de materias primas, procesamiento, manufactura, presentación del producto y consumidor final; el esquema de comercialización es semiestructurado entre tradicional y de circuitos cortos. Se identificaron cuatro áreas de oportunidad: procesamiento no estandarizado, condiciones inapropiadas de almacenamiento, ausencia de registros y deficientes canales de distribución y comercialización. Limitaciones del estudio/implicaciones: La proyección económica indicó que 35.8 % de los productos se destina al autoconsumo, 21.2 % se comercializa en mercados locales y municipales y el 43 % de la producción no se comercializa. Hallazgos/conclusiones: Para disminuir la cantidad de producto no comercializado y fortalecer la economía local, se propone ubicar estratégicamente centros de acopio para vincular a los productores en cadenas agroalimentarias cortas