Methodological approach to study the dynamics of production networks: Discrete-event simulation modelling

This paper shows how discrete-event simulation represents an appropriate tool for approaching the dynamics of production networks. Three important factors influencing production network dynamics, specifically finite production capacity, manufacturing lead time, and its variability are discussed and a basic discrete-event simulation model is presented. Such model, which in its basic form represents a simple retail/distribution two-stage supply chain, is then extended in order to take into account those factors that can not be included in a classical control theoretical model

Acoustic inversion of the cold water filaments off the Southwest coast of Portugal

Cold water filaments have important implications in the biological and chemical exchanges between the coastal and offshore ocean. The Cape São Vicente area in the Southwest coast of Portugal is a well know region where such phenomenon is observed. In October 2004, the multidisciplinary project ATOMS, involving oceanographers and acousticians, was conducted with the objective to complement the sea surface temperature (SST) satellite observation with a full water column characterization. Due to weather and technical conditions during the project sea trial, only CTD measurements in upper layers of the water column were performed. These at sea collected data together with archival data from the NODC database, allowed to establish realistic scenario of the 3D temperature distribution in the area, including deeper water layers. Archival data of temperature profiles suggest the occurrence of other important oceanic phenomena such as the subduction of warm Mediterrenean water, that should also influence the acoustic propagation. With the help of forward acoustic modelling the significance and signature of the individual oceanographic phenomena on the acoustic propagation, regarding different sampling strategies of the area by acoustic means is investigated. These investigations allowed to develop strategies to settle the main problem addressed by this work: invert the cold water filament structure by acoustic means in a complex environment where acoustic propagation is affected also by other important oceanic and bathymetric features. Since, the objective of this work, is to evaluate the ability to perform a 3D characterization of vertical structure of the ocean, a minimal transmit-receive acquisition composed of a suspended source from a ship and a drifting vertical array, is assumed. The spatial structure is obtained by a combination of inversions for ”mean” sound speed/temperature perturbations obtained for source-array cross-sections covering the area of interest. Matched-field and ray tracing based tomography techniques are used in the inversion for the ”mean” perturbations. The planned sampling strategies and necessary acoustic equipment to resolve such oceanic features is discussed having in mind future sea trials.ATOMS - POCTI/MAR/15296/1999; FCT Program POSI - QCA III

A Violência no Local de Trabalho em Instituições de Saúde: Um Estudo Monocêntrico sobre Causas, Consequências e Estratégias de Prevenção

Introduction: Workplace violence is one of the main risk factors in the professional world. Healthcare workers are at higher risk when compared to other sectors. Our study aimed to characterize physical and verbal violence in a public hospital and to define occupational health prevention and surveillance strategies. Material and Methods: Single center observational cross-sectional study, carried amongst healthcare workers in a public hospital in Lisbon. A qualitative survey was carried out through six in-depth interviews. A quantitative survey was carried through questionnaires delivered to 32 workers. A significance level of 5% was accepted in the assessment of statistical differences. The Mann-Whitney test and the Fisher’s exact test were used to calculate p values. Results: The main results are: (1) 41 violence incidents were reported in the quantitative phase; (2) 5/21 [23.81%] victims notified the incident to the occupational health department; (3) 18/21 [85.71%] victims reported a permanent state of hypervigilance; (4) 22/28 [78.57%] participants self-reported poor or no familiarity with internal reporting procedures; (5) 24/28 [85.71%] participants believed it is possible to minimize workplace violence. Discussion: Workplace violence is favored by unrestricted access to working areas, absence of security guards and police officers or scarce intervention. The low notification rate contributes to organizational lack of action. The state of hypervigilance reported in our study reflects the negative effects of threatening occupational stressors on mental health. Conclusion: Our results show that workplace violence is a relevant risk factor that significantly impacts workers’ health in a noxious manner, deserving a tailored occupational health approach whose priority areas and strategies have been determined.Introdução: A violência no local de trabalho é um dos principais fatores de risco no mundo do trabalho. Os trabalhadores da saúde apresentam um risco superior. O nosso estudo teve como objetivo caracterizar a violência física e verbal num hospital público e definir estratégias de prevenção e vigilância em saúde ocupacional. Material e Métodos: Estudo observacional transversal monocêntrico, conduzido num hospital público em Lisboa com trabalhadores da saúde. Foi realizado um inquérito qualitativo com entrevistas em profundidade a seis trabalhadores e um inquérito quantitativo com questionários a 32 trabalhadores. Aceitou-se um nível de significância de 5% na avaliação das diferenças estatísticas. O teste de Mann-Whitney e o teste exato de Fisher foram usados para calcular os valores de p. Resultados: Os principais resultados são: (1) 41 episódios reportados na fase quantitativa; (2) 5/21 [23,81%] vítimas notificaram o incidente; (3) 18/21 [85.71%] vítimas reportaram estados de hipervigilância permanente; (4) 22/28 [78,57%] participantes não conheciam ou conheciam mal os procedimentos de notificação; (5) 24/28 [85,71%] consideravam possível minimizar o problema. Discussão: A violência é favorecida pelo acesso livre às zonas de trabalho, ausência de agentes de segurança e polícia ou falta da respetiva intervenção. A baixa notificação contribui para a ausência de medidas organizacionais. O estado de hipervigilância relatado reflete o efeito prejudicial da exposição a fontes de stress e ameaça. Conclusão: A violência no local de trabalho é um fator de risco relevante, com impacto negativo na saúde dos trabalhadores e merece uma abordagem individualizada no âmbito da saúde ocupacional, cujas áreas e estratégias prioritárias foram definidas neste estudo. Palavras-chave: Fatores de Risco Profissionais; Prevenção; Saúde Ocupacional; Trabalhadores da Saúde; Violência no Local de trabalho.info:eu-repo/semantics/publishedVersio

Sediment-matrix igneous breccias at the top contacts of felsic units in the IPB : implications for VHMS exploration

The Volcanic Sedimentary Complex of the Iberian Pyrite Belt is dominated by mudstone units and comprises felsic lavas/domes and pyroclastic units that define lava-cryptodome-pumice cone volcanoes. Sediment-matrix igneous breccias may outline the contacts of volcanic units, occur within them, or lie laterally to the volcanic centres. These breccias can form by several processes, each with its genetic implications, having nevertheless very similar final aspect. We have distinguished and characterized several sediment-matrix breccia types. The most abundant types are sediment-infill volcanic breccia and peperite; however other types of sediment-matrix breccia were also identified. The correct identification of these breccias is crucial to reconstruct the volcanic centres and to define the stratigraphy, which in mineralized volcanic provinces is a major issue both for metallogenic and mineral exploration models

The effect of inventory record inaccuracy in information exchange supply chains

The goal of this paper is to quantify the impact of Inventory Record Inaccuracy on the dynamics of collaborative supply chains, both in terms of operational performance (i.e. order and inventory stability), and customer service level. To do so, we model an Information Exchange Supply Chain under shrinkage errors in the inventory item recording activity of their nodes, present the mathematical formulation of such supply chain model, and conduct a numerical simulation assuming different levels of errors. Results clearly show that Inventory Record Inaccuracy strongly compromises supply chain stability, particularly when moving upwards in the supply chain. Important managerial insights can be extracted from this analysis, such as the role of 'benefit-sharing' strategies in order to guarantee the advantage of investments in connectivity technologies

Obsessive Compulsive Disorder as a functional interhemispheric imbalance at the thalamic level

Obsessive Compulsive Disorder (OCD) involves failures in two main inhibitory processes, namely cognitive (obsessions) and behavioral (compulsions). Recent research has supported two cortical-subcortical pathways on OCD pathogenesis: (a) the frontostriatal loop (dorsolateral-caudate-striatum-thalamus) responsible for impairments of behavioral inhibition; (b) the orbitofrontal loop (orbitofrontal, medial prefrontal and cingulate) responsible for impairments with cognitive inhibitory processes. These failures in both cognitive and motor inhibitory systems may mediate several neuropsychological deficits in these patients, namely memory, attention, planning and decision making. But are those deficits related to specific hemispheric effects, namely functional imbalance between hemispheres? In this article we hypothesize that: (1) OCD patients have an inter-hemispheric functional imbalance, probably due to inadequate filtering at the thalamic level; (2) the restoration of inter-hemispheric balance, will be correlative to symptomatic improvement

Raising Awareness and Early Detection of Atrial Fibrillation, an Experience Resorting to Mobile Technology Centred on Informed Individuals

Background: Atrial fibrillation (AF) is a cardiac arrhythmia responsible for one third of ischemic strokes. Early detection of AF plays an important role in preventing embolic stroke. Objectives: This study aimed to test the feasibility of an awareness event including opportunistic screening for atrial fibrillation; and to test the reliability of the innovative portable electrocardiogram (ECG) device used. Methods: An awareness campaign was held during two weeks, where individuals consenting to participate in a pharmacist-led detection event, received a manual pulse check, were clinically evaluated and subject to a single-lead electrocardiogram using AliveCor Kardia® mobile. ECGs highlighted as possible AF were confirmed by the cardiologist and those signalled with abnormalities in cardiac rhythm were referred to their physician. Data were collected in a password protected application and analyzed using SPSS, v.24. The Kardia® mobile's sensitivity and specificity was tested against the standard 12-lead ECG. Results: The awareness event involved 223 individuals, among which 205 were screened. Mean age was 66 years (SD = 15) and hypertension was the most frequently reported (n = 107; 52.2%). Mean CHAD2DS2- VASc score was 3 (SD = 1.8). Cardiac irregularities were identified in 45 individuals, 14 confirmed to be new cases of AF (6.8%) by the cardiologist. The sensitivity and specificity were 90.9% and 97.4%. Conclusion: Data suggests this device to be potentially useful for opportunistic early detection of AF, provided interprofessional collaboration is guaranteed so that suspect cases are adequately managed and in a timely way. Fourteen new cases of AF were identified in the population studied, suggesting the pharmacist working in a multiprofessional context, may have had an important role in preventing potential ischemic-related strokes with this initiative. All healthcare professionals involved in the patient pathway should play a more active role in contributing to better health outcomes, particularly within primary care.info:eu-repo/semantics/publishedVersio