Neighborhood and Efficiency in Manufacturing in Brazilian Regions: A Spatial Markov Chain Analysis

This paper analyzes the geography of regional competitiveness in manufacturing in Brazil. The authors estimate stochastic frontiers to calculate regional efficiency of representative firms in 137 regions in the period 2000-2006, in four sectors defined by technological intensity. The efficiency results are analyzed using Markov Spatial Transition Matrices to provide insights into the transition of regions between efficiency levels, considering their local spatial context. The results indicate that geography plays an important role in manufacturing competitiveness. In particular, regions with more competitive neighbors are more likely to improve their relative efficiency (pull effect) over time, and regions with less competitive neighbors are more likely to lose relative efficiency (drag effect). The authors find that the pull effect is stronger than the drag effect.

Compensation for obesity-induced insulin resistance in dogs: Causal web analysis of the associations of leptin and GLP-1.

Obesity affects aspects of glucose homeostasis such as insulin secretion and insulin sensitivity. Hormones secreted by adipocytes like leptin mediate the metabolic consequences of obesity. Incretin hormones like glucagon-like peptide-1 (GLP-1) increase insulin secretion in response to changes in blood glucose concentration and have been proposed to regulate insulin secretion in fasting, overweight dogs. The aim of this study was to examine hormonal mechanisms by which adiposity alters glucose homeostasis, plasma insulin concentration, and insulin sensitivity in spontaneously overweight dogs.

Direct Effect of Birth Weight on Childhood Blood Pressure: a Causal Mediation Analysis

Background: Numerous studies have shown a negative association between birth weight (BW) and blood pressure (BP) later in life. To estimate the direct effect of BW on BP, it is conventional to condition on current weight (CW). However, such conditioning can induce collider stratification bias in the estimate of the direct effect. Objective: To bound the potential bias due to U, an unmeasured common cause of CW and BP, on the estimate of the (controlled) direct effect of BW on BP. Methods: Data from a school based study in Switzerland were used (N = 4,005; 2,010 B/1,995 G; mean age: 12.3 yr [range: 10.1-14.9]). Measured common causes of BW-BP (SES, smoking, body weight, and hypertension status of the mother) and CW-BP (breastfeeding and child's physical activity and diet) were identified with DAGs. Linear regression models were fitted to estimate the association between BW and BP. Sensitivity analyses were conducted to assess the potential effect of U on the association between BW and BP. U was assumed 1) to be a binary variable that affected BP by the same magnitude in low BWand in normal BW children and 2) to have a different prevalence in low BW children and in normal BW children for a given CW. Results: A small negative association was observed between BW and BP [beta: -0.3 mmHg/kg (95% CI: -0.9 to 0.3)]. The association was strengthened upon conditioning for CW [beta: -1.5 mmHg/kg (95% CI: -2.1 to -0.9)]. Upon further conditioning on common causes of BW-BP and CW-BP, the association did not change substantially [beta: -1.4 mmHg/kg (95% CI: -2.0 to -0.8)]. The negative association could be explained by U only if U was strongly associated with BP and if there was a large difference in the prevalence of U between low BWand normal BW children. Conclusion: The observed negative association between BW and BP upon adjustment for CW was not easily explained by an unmeasured common cause of CWand BP.

Determination of the critical activities of a public-private intermediary organization with the help of value chain analysis

Tämän diplomityön tavoitteena oli selvittää arvoketjuanalyysin avulla toiminnot, joilla voittoatavoittelemattoman, julkisen osakeyhtiön toimintaa voitaisiin kuvata. Tarkoituksena oli selvittää mainitut toiminnot yleisesti ja luoda malli kohdeyrityksen arvoketjusta ja sen toiminnoista. Tutkielma jakautuu teoreettiseen ja empiiriseen osaan. Ensimmäinen pohjautuu aikaisempaan tutkimukseen ja kirjallisuuteen sidosryhmistä, arvon muodostumisesta ja arvoketjuanalyysistä. Jälkimmäinen on laadullista tapaustutkimusta. Empiriassa mallinnettiin Lappeenranta Innovation Oy:nsisäisiä toimintoja ja sidosryhmien odotuksia. Empiirinen tutkimus perustui kohdeyrityksen omistajille ja henkilöstölle tehtyihin haastatteluihin sekä yrityksen toiminnan päivittäiseen seurantaan. Johtopäätöksenätodettiin, että julkisen, voittoa tavoittelemattoman yrityksen toiminnot on mahdollista kuvata arvoketjuanalyysin avulla. Alan ja yrityksen asettamat erityispiirteet toivat haasteita määrittelylle, mutta silti arvoketju antoi selkeän tavan kohdeyrityksen toimintojen mallintamiselle.

Value chain analysis in graphical boards business

Tällä tutkielmalla oli kaksi tavoitetta. Ensimmäinen tavoite oli selvittää, kuinka valittujen tuotteiden arvoa asiakkaiden silmissä voisi lisätä. Toisena tavoitteena oli selvittää tuotteiden arvon lisääntyminen arvoketjun jokaisella portaalla kartonkitehtaaltaloppuasiakkaalle. Tutkimuksen kohteena oli kolme erilaista arvoketjua. Tutkimusoli luonteeltaan kvalitatiivinen ja tarvittavat tiedot kerättiin haastatteluilla. Tutkimuksen tuloksena voidaan mainita, että asiakkaat arvostavat laskua kustannuksissa enemmän kuin lisähyötyjä. Myös prosentuaalinen arvonlisäys valittuihintuotteisiin arvoketjun eri portaissa saatiin selville. Tästä työstä on tehty kaksi versiota; tämä versio, joka tulee julkiseksi neljän vuoden salassapitoajan jälkeen, ja toinen versio, joka sisältää arkaluontoisempaa kustannusinformaatiotaja on siitä syystä kokonaan salainen.

A Markov chain analysis of emotional exchange in voice-to-voice communication: Testing for the mimicry hypothesis of emotional contagion

Mimicry is a central plank of the emotional contagion theory; however, it was only tested with facial and postural emotional stimuli. This study explores the existence of mimicry in voice-to-voice communication by analyzing 8,747 sequences of emotional displays between customers and employees in a call-center context. We listened live to 967 telephone inter-actions, registered the sequences of emotional displays, and analyzed them with a Markov chain. We also explored other propositions of emotional contagion theory that were yet to be tested in vocal contexts. Results supported that mimicry is significantly present at all levels. Our findings fill an important gap in the emotional contagion theory; have practical implications regarding voice-to-voice interactions; and open doors for future vocal mimicry research.

BIOMASS SUPPLY CHAIN ANALYSIS WITH DENSIFIED WASTE

ABSTRACT The possibility to vary the energy matrix, thus reducing the dependency on fossil fuels, has amplified the acceptance of biomass as an alternative fuel. Despite being a cheap and renewable option and the fact that Brazil is a major producer of waste from agriculture and forestry activities, the use of these materials has barriers due to its low density and low energetic efficiency, which can raise the costs of its utilization. Biomass densification has drawn attention due to its advantage in comparison to in natura biomass due to its better physical and combustion characteristics. The objective of this paper is to evaluate the impact of biomass densification in distribution and transport costs. To reach this objective, a mathematical model was used to represent decisions at a supply chain that coordinates the purchase and sale of forestry and wood waste. The model can evaluate the options to deliver biomass through the supply chain combining demand meeting and low cost. Results point to the possibility of an economy of 60% in transport cost and a reduction of 63% in the required quantity of trucks when densified waste is used. However, costs related to the densifying process lead to an increase of total supply costs of at least 37,8% in comparison to in natura waste. Summing up, the viability of biomass briquettes industry requires a cheaper densification process.

Global Spare Parts Supply Chain Analysis

In today’s global industrial service business, markets are dynamic and finding new ways of value creation towards customers has become more and more challenging. Customer orientation is needed because of the demanding after-sales business which is both quickly changing and stochastic in nature. In after-sales business customers require fast and reliable service for their spare part needs. This thesis objective is to clarify this challenging after-sales business environment and find ways to increase customer satisfaction via balanced measurement system which will help to find possible targets to reduce order cycle times in a large metal and mineral company Outotec (Filters)’ Spare Part Supply business line. In case study, internal documents and data and numerical calculations together with qualitative interviews with different persons in key roles of Spare Part Supply organizations are used to analyze the performance of different processes from the spare parts delivery function. The chosen performance measurement tool is Balanced Scorecard which is slightly modified to suit the lead time study from customer’s perspective better. Findings show that many different processes in spare parts supply are facing different kind of challenges in achieving the lead time levels wanted and that these processes’ problems seem to accumulate. Findings also show that putting effort in supply side challenges and information flows visibility should give the best results.

The Cycle Times of Working Capital: Financial Value Chain Analysis Method

Interest towards working capital management increased among practitioners and researchers because the financial crisis of 2008 caused the deterioration of the general financial situation. The importance of managing working capital effectively increased dramatically during the financial crisis. On one hand, companies highlighted the importance of working capital management as part of short-term financial management to overcome funding difficulties. On the other hand, in academia, it has been highlighted the need to analyze working capital management from a wider perspective namely from the value chain perspective. Previously, academic articles mostly discussed working capital management from a company-centered perspective. The objective of this thesis was to put working capital management in a wider and more academic perspective and present case studies of the value chains of industries as instrumental in theoretical contributions and practical contributions as complementary to theoretical contributions and conclusions. The principal assumption of this thesis is that selffinancing of value chains can be established through effective working capital management. Thus, the thesis introduces the financial value chain analysis method which is employed in the empirical studies. The effectiveness of working capital management of the value chains is studied through the cycle time of working capital. The financial value chain analysis method employed in this study is designed for considering value chain level phenomena. This method provides a holistic picture of the value chain through financial figures. It extends the value chain analysis to the industry level. Working capital management is studied by the cash conversion cycle that measures the length (days) of time a company has funds tied up in working capital, starting from the payment of purchases to the supplier and ending when remittance of sales is received from the customers. The working capital management practices employed in the automotive, pulp and paper and information and communication technology industries have been studied in this research project. Additionally, the Finnish pharmaceutical industry is studied to obtain a deeper understanding of the working capital management of the value chain. The results indicate that the cycle time of working capital is constant in the value chain context over time. The cash conversion cycle of automotive, pulp and paper, and ICT industries are on average 70, 60 and 40 days, respectively. The difference is mainly a consequence of the different cycle time of inventories. The financial crisis of 2008 affected the working capital management of the industries similarly. Both the cycle time of accounts receivable and accounts payable increased between 2008 and 2009. The results suggest that the companies of the automotive, pulp and paper and ICT value chains were not able to self-finance. Results do not indicate the improvement of value chains position in regard to working capital management either. The findings suggest that companies operating in the Finnish pharmaceutical industry are interested in developing their own working capital management, but collaboration with the value chain partners is not considered interesting. Competition no longer occurs between individual companies, but between value chains. Therefore the financial value chain analysis method introduced in this thesis has the potential to support value chains in improving their competitiveness.

Intra- and inter-hemispheric interactions in somatosensory processing of pain : dynamical causal modeling analysis of fMRI data

La douleur est une expérience perceptive comportant de nombreuses dimensions. Ces dimensions de douleur sont inter-reliées et recrutent des réseaux neuronaux qui traitent les informations correspondantes. L’élucidation de l'architecture fonctionnelle qui supporte les différents aspects perceptifs de l'expérience est donc une étape fondamentale pour notre compréhension du rôle fonctionnel des différentes régions de la matrice cérébrale de la douleur dans les circuits corticaux qui sous tendent l'expérience subjective de la douleur. Parmi les diverses régions du cerveau impliquées dans le traitement de l'information nociceptive, le cortex somatosensoriel primaire et secondaire (S1 et S2) sont les principales régions généralement associées au traitement de l'aspect sensori-discriminatif de la douleur. Toutefois, l'organisation fonctionnelle dans ces régions somato-sensorielles n’est pas complètement claire et relativement peu d'études ont examiné directement l'intégration de l'information entre les régions somatiques sensorielles. Ainsi, plusieurs questions demeurent concernant la relation hiérarchique entre S1 et S2, ainsi que le rôle fonctionnel des connexions inter-hémisphériques des régions somatiques sensorielles homologues. De même, le traitement en série ou en parallèle au sein du système somatosensoriel constitue un autre élément de questionnement qui nécessite un examen plus approfondi. Le but de la présente étude était de tester un certain nombre d'hypothèses sur la causalité dans les interactions fonctionnelle entre S1 et S2, alors que les sujets recevaient des chocs électriques douloureux. Nous avons mis en place une méthode de modélisation de la connectivité, qui utilise une description de causalité de la dynamique du système, afin d'étudier les interactions entre les sites d'activation définie par un ensemble de données provenant d'une étude d'imagerie fonctionnelle. Notre paradigme est constitué de 3 session expérimentales en utilisant des chocs électriques à trois différents niveaux d’intensité, soit modérément douloureux (niveau 3), soit légèrement douloureux (niveau 2), soit complètement non douloureux (niveau 1). Par conséquent, notre paradigme nous a permis d'étudier comment l'intensité du stimulus est codé dans notre réseau d'intérêt, et comment la connectivité des différentes régions est modulée dans les conditions de stimulation différentes. Nos résultats sont en faveur du mode sériel de traitement de l’information somatosensorielle nociceptive avec un apport prédominant de la voie thalamocorticale vers S1 controlatérale au site de stimulation. Nos résultats impliquent que l'information se propage de S1 controlatéral à travers notre réseau d'intérêt composé des cortex S1 bilatéraux et S2. Notre analyse indique que la connexion S1→S2 est renforcée par la douleur, ce qui suggère que S2 est plus élevé dans la hiérarchie du traitement de la douleur que S1, conformément aux conclusions précédentes neurophysiologiques et de magnétoencéphalographie. Enfin, notre analyse fournit des preuves de l'entrée de l'information somatosensorielle dans l'hémisphère controlatéral au côté de stimulation, avec des connexions inter-hémisphériques responsable du transfert de l'information à l'hémisphère ipsilatéral.

Persistence of UK Real Estate returns: a Markov chain analysis

The persistence of investment performance is a topic of perennial interest to investors. Efficient Markets theory tells us that past performance can not be used to predict future performance yet investors appear to be influenced by the historical performance in making their investment allocation decisions. The problem has been of particular interest to investors in real estate; not least because reported returns from investment in real estate are serially correlated thus implying some persistence in investment performance. This paper applies the established approach of Markov Chain analysis to investigate the relationship between past and present performance of UK real estate over the period 1981 to 1996. The data are analysed by sector, region and size. Furthermore some variations in investment performance classification are reported and the results are shown to be robust.

Agrofood chain analysis: production, commercialisation and consumption of healthy food for population at risk of poverty in Italy

Italy registers a fast increase of low income population. Academics and policy makers consider income inequalities as a key determinant for low or inadequate healthy food consumption. Thus the objective is to understand how to overcome the agrofood chain barriers towards healthy food production, commercialisation and consumption for population at risk of poverty (ROP) in Italy. The study adopts a market oriented food chain approach, focusing the research ambit on ROP consumers, processing industries and retailers. The empirical investigation adopts a qualitative methodology with an explorative approach. The actors are investigated through 4 focus groups for consumers and carrying out 27 face to face semi-structured interviews for industries and retailers’ representatives. The results achieved provide the perceptions of each actor integrated into an overall chain approach. The analysis shows that all agrofood actors lack of an adequate level of knowledge towards healthy food definition. Food industries and retailers also show poor awareness about ROP consumers’ segment. In addition they perceive that the high costs for producing healthy food conflict with the low economic performances expected from ROP consumers’ segment. These aspects induce a scarce interest in investing on commercialisation strategies for healthy food for ROP consumers. Further ROP consumers show other notable barriers to adopt healthy diets caused, among others, by a personal strong negative attitude and lack of motivation. The personal barriers are also negatively influenced by several external socio-economic factors. The solutions to overcome the barriers shall rely on the improvement of the agrofood chain internal relations to identify successful strategies for increasing interest on low cost healthy food. In particular the focus should be on improved collaboration on innovation adoption and marketing strategies, considering ROP consumers’ preferences and needs. An external political intervention is instead necessary to fill the knowledge and regulations’ gaps on healthy food issues.

Semiparametric Theory for Causal Mediation Analysis: efficiency bounds, multiple robustness, and sensitivity analysis

Whilst estimation of the marginal (total) causal effect of a point exposure on an outcome is arguably the most common objective of experimental and observational studies in the health and social sciences, in recent years, investigators have also become increasingly interested in mediation analysis. Specifically, upon establishing a non-null total effect of the exposure, investigators routinely wish to make inferences about the direct (indirect) pathway of the effect of the exposure not through (through) a mediator variable that occurs subsequently to the exposure and prior to the outcome. Although powerful semiparametric methodologies have been developed to analyze observational studies, that produce double robust and highly efficient estimates of the marginal total causal effect, similar methods for mediation analysis are currently lacking. Thus, this paper develops a general semiparametric framework for obtaining inferences about so-called marginal natural direct and indirect causal effects, while appropriately accounting for a large number of pre-exposure confounding factors for the exposure and the mediator variables. Our analytic framework is particularly appealing, because it gives new insights on issues of efficiency and robustness in the context of mediation analysis. In particular, we propose new multiply robust locally efficient estimators of the marginal natural indirect and direct causal effects, and develop a novel double robust sensitivity analysis framework for the assumption of ignorability of the mediator variable.

On Causal Mediation Analysis with a Survival Outcome

Suppose that having established a marginal total effect of a point exposure on a time-to-event outcome, an investigator wishes to decompose this effect into its direct and indirect pathways, also know as natural direct and indirect effects, mediated by a variable known to occur after the exposure and prior to the outcome. This paper proposes a theory of estimation of natural direct and indirect effects in two important semiparametric models for a failure time outcome. The underlying survival model for the marginal total effect and thus for the direct and indirect effects, can either be a marginal structural Cox proportional hazards model, or a marginal structural additive hazards model. The proposed theory delivers new estimators for mediation analysis in each of these models, with appealing robustness properties. Specifically, in order to guarantee ignorability with respect to the exposure and mediator variables, the approach, which is multiply robust, allows the investigator to use several flexible working models to adjust for confounding by a large number of pre-exposure variables. Multiple robustness is appealing because it only requires a subset of working models to be correct for consistency; furthermore, the analyst need not know which subset of working models is in fact correct to report valid inferences. Finally, a novel semiparametric sensitivity analysis technique is developed for each of these models, to assess the impact on inference, of a violation of the assumption of ignorability of the mediator.