Assessment of Laparoscopic Skills Performance: 2D Versus 3D Vision and Classic Instrument Versus New Hand-Held Robotic Device for Laparoscopy

Introduction and Objectives. Laparoscopic surgery has undeniable advantages, such as reduced postoperative pain, smaller incisions, and faster recovery. However, to improve surgeons’ performance, ergonomic adaptations of the laparoscopic instruments and introduction of robotic technology are needed. The aim of this study was to ascertain the influence of a new hand-held robotic device for laparoscopy (HHRDL) and 3D vision on laparoscopic skills performance of 2 different groups, naïve and expert. Materials and Methods. Each participant performed 3 laparoscopic tasks—Peg transfer, Wire chaser, Knot—in 4 different ways. With random sequencing we assigned the execution order of the tasks based on the first type of visualization and laparoscopic instrument. Time to complete each laparoscopic task was recorded and analyzed with one-way analysis of variance. Results. Eleven experts and 15 naïve participants were included. Three-dimensional video helps the naïve group to get better performance in Peg transfer, Wire chaser 2 hands, and Knot; the new device improved the execution of all laparoscopic tasks (P < .05). For expert group, the 3D video system benefited them in Peg transfer and Wire chaser 1 hand, and the robotic device in Peg transfer, Wire chaser 1 hand, and Wire chaser 2 hands (P < .05). Conclusion. The HHRDL helps the execution of difficult laparoscopic tasks, such as Knot, in the naïve group. Three-dimensional vision makes the laparoscopic performance of the participants without laparoscopic experience easier, unlike those with experience in laparoscopic procedures.

Taking the "cross" out of cross-cultural transfer of management practice

Multi-national enterprises often attempt to replicate successful management practices in "foreign" environments. However, such practices may be ethnocentric because they fit the assumptions, behaviors, expectations, and values of the home cultural environment. Unless the underlying assumptions are shared, transfer to a differing environment may fail. Even if the focus is shifted from cultural differences to implementation, implementation approaches may also be criticized as ethnocentric for the same reasons. In this article, a non-ethnocentric model is expanded and used to test the portability of one management practice, performance appraisal, from the USA to Brazil. This "Test of Portability" may help managers understand which management practices are portable, and, perhaps even more valuable, provide a rationale for adaptation or rejection.

Preliminary Overview over Requirements Regarding Tools and Methods Derived from LUDA Cases

LUDA is a research project of Key Action 4 "City of Tomorrow & Cultural Heritage" of the programme "Energy, Environment and Sustainable Development" within the Fifth Framework Programme of the European Commission

Scenario Planning and Evaluation of Pricing Strategies in the Portuguese Bulk LPG Market

Portugal has the largest LPG (Liquefied Petroleum Gas) share of primary energy demand in the EU (about 5%). Due to the increasing international cost of LPG in the last years and the high price sensitivity of the consumers the preference for substitute energy sources in new and existing consumers has been increasing. To select the kind of energy, some consumer estimate and compare the total costs while others follow agents (equipment sellers) recommendations. It takes time to build agents perception about the most advantageous source of energy, which is seen as an important resource that drives client resource accumulation and retention. Marketing strategies have to take into consideration some market dynamic effects derived from the accumulation and depletion of these resources. A simple system dynamics model was built, combined with Economic Value Added framework, to evaluate some pricing strategies under different scenarios of LPG international cost.

Scenario Planning and Evaluation of Pricing Strategies in the Portuguese Bulk LPG Market

Portugal has the largest LPG (Liquefied Petroleum Gas) share of primary energy demand in the EU (about 5%). Due to the increasing international cost of LPG in the last years and the high price sensitivity of the consumers the preference for substitute energy sources in new and existing consumers has been increasing. To select the kind of energy, some consumer estimate and compare the total costs while others follow agents (equipment sellers) recommendations. It takes time to build agents perception about the most advantageous source of energy, which is seen as an important resource that drives client resource accumulation and retention. Marketing strategies have to take into consideration some market dynamic effects derived from the accumulation and depletion of these resources. A simple system dynamics model was built, combined with Economic Value Added framework, to evaluate some pricing strategies under different scenarios of LPG international cost.

Seasonal variation of total particulate matter and children respiratory diseases at Lisbon primary schools using passive methods

In this work, 14 primary schools of Lisbon city, Portugal, followed a questionnaire of the ISAAC - International Study of Asthma and Allergies in Childhood Program, in 2009/2010. The questionnaire contained questions to identify children with respiratory diseases (wheeze, asthma and rhinitis). Total particulate matter (TPM) was passively collected inside two classrooms of each of 14 primary schools. Two types of filter matrices were used to collect TPM: Millipore (IsoporeTM) polycarbonate and quartz. Three campaigns were selected for the measurement of TPM: Spring, Autumn and Winter. The highest difference between the two types of filters is that the mass of collected particles was higher in quartz filters than in polycarbonate filters, even if their correlation is excellent. The highest TPM depositions occurred between October 2009 and March 2010, when related with rhinitis proportion. Rhinitis was found to be related to TPM when the data were grouped seasonally and averaged for all the schools. For the data of 2006/2007, the seasonal variation was found to be related to outdoor particle deposition (below 10 μm).

Epidemiological methods for research with drug misusers: review of methods for studying prevalence and morbidity

Epidemiological studies of drug misusers have until recently relied on two main forms of sampling: probability and convenience. The former has been used when the aim was simply to estimate the prevalence of the condition and the latter when in depth studies of the characteristics, profiles and behaviour of drug users were required, but each method has its limitations. Probability samples become impracticable when the prevalence of the condition is very low, less than 0.5% for example, or when the condition being studied is a clandestine activity such as illicit drug use. When stratified random samples are used, it may be difficult to obtain a truly representative sample, depending on the quality of the information used to develop the stratification strategy. The main limitation of studies using convenience samples is that the results cannot be generalised to the whole population of drug users due to selection bias and a lack of information concerning the sampling frame. New methods have been developed which aim to overcome some of these difficulties, for example, social network analysis, snowball sampling, capture-recapture techniques, privileged access interviewer method and contact tracing. All these methods have been applied to the study of drug misuse. The various methods are described and examples of their use given, drawn from both the Brazilian and international drug misuse literature.

Constructing good deals in discrete time arbitrage-free dynamic pricing models

Recent literature has proved that many classical pricing models (Black and Scholes, Heston, etc.) and risk measures (V aR, CV aR, etc.) may lead to “pathological meaningless situations”, since traders can build sequences of portfolios whose risk leveltends to −infinity and whose expected return tends to +infinity, i.e., (risk = −infinity, return = +infinity). Such a sequence of strategies may be called “good deal”. This paper focuses on the risk measures V aR and CV aR and analyzes this caveat in a discrete time complete pricing model. Under quite general conditions the explicit expression of a good deal is given, and its sensitivity with respect to some possible measurement errors is provided too. We point out that a critical property is the absence of short sales. In such a case we first construct a “shadow riskless asset” (SRA) without short sales and then the good deal is given by borrowing more and more money so as to invest in the SRA. It is also shown that the SRA is interested by itself, even if there are short selling restrictions.