On the Segregation of Genetically Modified, Conventional, and Organic Products in European Agriculture: A Multi-market Equilibrium Analysis, October 2005

Evaluating the possible benefits of the introduction of genetically modified (GM) crops must address the issue of consumer resistance as well as the complex regulation that has ensued. In the European Union (EU) this regulation envisions the “co-existence” of GM food with conventional and quality-enhanced products, mandates the labelling and traceability of GM products, and allows only a stringent adventitious presence of GM content in other products. All these elements are brought together within a partial equilibrium model of the EU agricultural food sector. The model comprises conventional, GM and organic food. Demand is modelled in a novel fashion, whereby organic and conventional products are treated as horizontally differentiated but GM products are vertically differentiated (weakly inferior) relative to conventional ones. Supply accounts explicitly for the land constraint at the sector level and for the need for additional resources to produce organic food. Model calibration and simulation allow insights into the qualitative and quantitative effects of the large-scale introduction of GM products in the EU market. We find that the introduction of GM food reduces overall EU welfare, mostly because of the associated need for costly segregation of non-GM products, but the producers of quality-enhanced products actually benefit.

BIMS: Biomedical Information Management System

This final year project presents the design principles and prototype implementation of BIMS (Biomedical Information Management System), a flexible software system which provides an infrastructure to manage all information required by biomedical research projects.The BIMS project was initiated with the motivation to solve several limitations in medical data acquisition of some research projects, in which Universitat Pompeu Fabra takes part. These limitations,based on the lack of control mechanisms to constraint information submitted by clinicians, impact on the data quality, decreasing it.BIMS can easily be adapted to manage information of a wide variety of clinical studies, not being limited to a given clinical specialty. The software can manage both, textual information, like clinical data (measurements, demographics, diagnostics, etc ...), as well as several kinds of medical images (magnetic resonance imaging, computed tomography, etc ...). Moreover, BIMS provides a web - based graphical user interface and is designed to be deployed in a distributed andmultiuser environment. It is built on top of open source software products and frameworks.Specifically, BIMS has been used to represent all clinical data being currently used within the CardioLab platform (an ongoing project managed by Universitat Pompeu Fabra), demonstratingthat it is a solid software system, which could fulfill requirements of a real production environment.

Financing Constraints, Irreversibility, and Investment Dynamics

We develop a model of an industry with many heterogeneous firms that face both financing constraints and irreversibility constraints. The financing constraint implies that firms cannot borrow unless the debt is secured by collateral; the irreversibility constraint that they can only sell their fixed capital by selling their business. We use this model to examine the cyclical behavior of aggregate fixed investment, variable capital investment, and output in the presence of persistent idiosyncratic and aggregate shocks. Our model yields three main results. First, the effect of the irreversibility constraint on fixed capital investment is reinforced by the financing constraint. Second, the effect of the financing constraint on variable capital investment is reinforced by the irreversibility constraint. Finally, the interaction between the two constraints is key for explaining why input inventories and material deliveries of US manufacturing firms are so volatile and procyclical, and also why they are highly asymmetrical over the business cycle.

Trait decoupling promotes evolutionary diversification of the trophic and acoustic system of damselfishes.

Trait decoupling, wherein evolutionary release of constraints permits specialization of formerly integrated structures, represents a major conceptual framework for interpreting patterns of organismal diversity. However, few empirical tests of this hypothesis exist. A central prediction, that the tempo of morphological evolution and ecological diversification should increase following decoupling events, remains inadequately tested. In damselfishes (Pomacentridae), a ceratomandibular ligament links the hyoid bar and lower jaws, coupling two main morphofunctional units directly involved in both feeding and sound production. Here, we test the decoupling hypothesis by examining the evolutionary consequences of the loss of the ceratomandibular ligament in multiple damselfish lineages. As predicted, we find that rates of morphological evolution of trophic structures increased following the loss of the ligament. However, this increase in evolutionary rate is not associated with an increase in trophic breadth, but rather with morphofunctional specialization for the capture of zooplanktonic prey. Lineages lacking the ceratomandibular ligament also shows different acoustic signals (i.e. higher variation of pulse periods) from others, resulting in an increase of the acoustic diversity across the family. Our results support the idea that trait decoupling can increase morphological and behavioural diversity through increased specialization rather than the generation of novel ecotypes.

The representations of adolescents about gynecological consultation

Objective: To analyze the social representation of adolescents about gynecological consultation and the influence of those in searching for consultations. Method: Qualitative descriptive study based on the Social Representations Theory, conducted with 50 adolescents in their last year of middle school. The data was collected between April and May of 2010 by Evocations and a Focal Group. The software EVOC and contextual analysis were used in the data treatment. Results: The elements fear and constraint, constant in the central nucleus, can justify the low frequency of adolescents in consultations. The term embarrassment in the peripheral system reinforce current sociocultural norms, while prevention, associated with learning about sex and clarifying doubts, allows to envision an educative function. Obtained testimonies in the focal groups exemplify and reinforce those findings. Conclusion: For an effective health education, professionals, including nurses, need to clarify the youth individually and collectively about their rights to privacy, secrecy, in addition to focus the gynecological consultation as a promotion measure to sexual and reproductive health.

Segmental copy number variation shapes tissue transcriptomes.

Copy number variation (CNV) is a key source of genetic diversity, but a comprehensive understanding of its phenotypic effect is only beginning to emerge. We have generated a CNV map in wild mice and classical inbred strains. Genome-wide expression data from six major organs show not only that expression of genes within CNVs tend to correlate with copy number changes, but also that CNVs influence the expression of genes in their vicinity, an effect that extends up to half a megabase. Genes within CNVs show lower expression and more specific spatial expression patterns than genes mapping elsewhere. Our analyses reveal differential constraint on copy number changes of genes expressed in different tissues. Dosage alterations of brain-expressed genes are less frequent than those of other genes and are buffered by tighter transcriptional regulation. Our study provides initial evidence that CNVs shape tissue transcriptomes on a global scale.

Aplicação da Teoria dos Constrangimentos ao Sector de Transporte Público Colectivo – O Caso Da Transcor-Sv, S.A. –

Com a necessidade de adaptação às crescentes mudanças no mundo dos negócios, ao longo dos últimos anos a contabilidade de gestão tem sido criticada, pois os métodos de custeio tradicionalmente utilizados, não estão acompanhando estas mudanças, incapacitando a utilização destes como instrumentos de gestão eficazes. Na busca de ferramentas de gestão para auxiliar na tomada de decisão, foi desenvolvida a Teoria dos Constrangimentos (TOC) ou das Restrições, uma ferramenta de gestão cuja premissa é a identificação de constrangimentos que limitem a capacidade da empresa no alcance da sua meta. Muito se tem escrito sobre a aplicação desta teoria em empresas industriais, uma vez que, nessas organizações a existência de constrangimentos está mais presente. Tendo como objectivo verificar a viabilidade de aplicação desta teoria na actividade de prestação de serviços, o presente trabalho refere-se ao estudo de caso numa empresa de prestação de serviço de transporte público colectivo de passageiros TRANSCOR-SV,S.A., localizada na ilha de São Vicente. Para tal, identificámos factores considerados constrangimentos nos sistemas de transporte colectivo, através da aplicação de um questionário. Com estes factores em mãos, aplicámos a metodologia baseada no Processo de Raciocínio (PR) da OC. With the need of adaption to the growing changes happening in the business world, throughout the last few years, management accounting has been much criticized for the methods of costing used are not following such changes, turning the use of these meth-ods powerless to help provide an effective management in companies. In the search for creating useful tools to help guarantee effectiveness in decision making in companies, the Constraint Theory, or Restriction Theory, was created as a management tool in which the fundamental objective is to identify constraints that limit the capacity of a company to reach its goals successfully. Much has been written about the application of this theory in corporate industries, once in such business the existence of constraints is very present. With the aim of verifying the viability of its use in service rendered in collective public transport, this work is characterized by the case study of one such company in São Vicente. Initially, some factors that can be seen as constraints were identified in the public transport service, through the use of a questionnaire. With the results, follows the employ of the Thinking Process methodology in the analysis based in the Theory of Constraint.

Signal search analysis server.

Signal search analysis is a general method to discover and characterize sequence motifs that are positionally correlated with a functional site (e.g. a transcription or translation start site). The method has played an instrumental role in the analysis of eukaryotic promoter elements. The signal search analysis server provides access to four different computer programs as well as to a large number of precompiled functional site collections. The programs offered allow: (i) the identification of non-random sequence regions under evolutionary constraint; (ii) the detection of consensus sequence-based motifs that are over- or under-represented at a particular distance from a functional site; (iii) the analysis of the positional distribution of a consensus sequence- or weight matrix-based sequence motif around a functional site; and (iv) the optimization of a weight matrix description of a locally over-represented sequence motif. These programs can be accessed at: http://www.isrec.isb-sib.ch/ssa/.

Portfolio delegation under short-selling constraints

In this paper we study delegated portfolio management when themanager's ability to short-sell is restricted. Contrary to previousresults, we show that under moral hazard, linear performance-adjustedcontracts do provide portfolio managers with incentives to gatherinformation. The risk-averse manager's optimal effort is an increasingfunction of her share in the portfolio's return. This result affectsthe risk-averse investor's optimal contract decision. The first best,purely risk-sharing contract is proved to be suboptimal. Usingnumerical methods we show that the manager's share in the portfolioreturn is higher than the rst best share. Additionally, this deviationis shown to be: (i) increasing in the manager's risk aversion and (ii)larger for tighter short-selling restrictions. When the constraint isrelaxed the optimal contract converges towards the first best risksharing contract.

Recursive contracts

We obtain a recursive formulation for a general class of contractingproblems involving incentive constraints. Under these constraints,the corresponding maximization (sup) problems fails to have arecursive solution. Our approach consists of studying the Lagrangian.We show that, under standard assumptions, the solution to theLagrangian is characterized by a recursive saddle point (infsup)functional equation, analogous to Bellman's equation. Our approachapplies to a large class of contractual problems. As examples, westudy the optimal policy in a model with intertemporal participationconstraints (which arise in models of default) and intertemporalcompetitive constraints (which arise in Ramsey equilibria).

Financing constraints, irreversibility and investment dynamics

We develop a model of an industry with many heterogeneous firms that face both financingconstraints and irreversibility constraints. The financing constraint implies that firmscannot borrow unless the debt is secured by collateral; the irreversibility constraint thatthey can only sell their fixed capital by selling their business. We use this model to examinethe cyclical behavior of aggregate fixed investment, variable capital investment, and outputin the presence of persistent idiosyncratic and aggregate shocks. Our model yields threemain results. First, the effect of the irreversibility constraint on fixed capital investmentis reinforced by the financing constraint. Second, the effect of the financing constraint onvariable capital investment is reinforced by the irreversibility constraint. Finally, the interactionbetween the two constraints is key for explaining why input inventories and materialdeliveries of US manufacturing firms are so volatile and procyclical, and also why they arehighly asymmetrical over the business cycle.

Locating emergency services with different priorities: The priority queuing covering location problem

Previous covering models for emergency service consider all the calls to be of the sameimportance and impose the same waiting time constraints independently of the service's priority.This type of constraint is clearly inappropriate in many contexts. For example, in urban medicalemergency services, calls that involve danger to human life deserve higher priority over calls formore routine incidents. A realistic model in such a context should allow prioritizing the calls forservice.In this paper a covering model which considers different priority levels is formulated andsolved. The model heritages its formulation from previous research on Maximum CoverageModels and incorporates results from Queuing Theory, in particular Priority Queuing. Theadditional complexity incorporated in the model justifies the use of a heuristic procedure.

Evolution at Two Levels in Fire Ants: The Relationship between Patterns of Gene Expression and Protein Sequence Evolution.

Variation in protein sequence and gene expression each contribute to phenotypic diversity, and may be subject to similar selective pressures. Eusocial insects are particularly useful for investigating the evolutionary link between protein sequence and condition-dependent patterns of gene expression because gene expression plays a central role in determining differences between eusocial insect sexes and castes. We investigated the relationship between protein coding sequence evolution and gene expression patterns in the fire ants Solenopsis invicta, S. richteri, and their hybrids to gain greater insight into how selection jointly operates on gene expression and coding sequence. We found that genes with high expression variability within castes and sexes were frequently differentially expressed between castes and sexes, as well as between species and hybrids. These results indicate that genes showing high variation in expression in one context also tend to show high variation in expression in other contexts. Our analyses further revealed that variation in both intra- and interspecific gene expression was positively associated with rate of protein sequence evolution in Solenopsis. This suggests that selective constraints on a gene operate both at the level of protein sequence and at the level of gene expression regulation. Overall, our study provides one of the strongest demonstrations that selective constraints mediate both protein sequence evolution and gene expression variability across different biological contexts and timescales.

Corporate finance and the monetary transmission mechanism

This paper analyzes the transmission mechanisms of monetarypolicy in a general equilibrium model of securities marketsand banking with asymmetric information. Banks' optimal asset/liability policy is such that in equilibrium capital adequacy constraints are always binding. Asymmetric information about banks' net worth adds a cost to outside equity capital, which limits the extent to which banks can relax their capital constraint. In this context monetarypolicy does not affect bank lending through changes in bank liquidity. Rather, it has the effect of changing theaggregate composition of financing by firms. The model also produces multiple equilibria, one of which displays all the features of a "credit crunch". Thus, monetary policy can also have large effects when it induces a shift from one equilibrium to the other.

Specificity revisited: The role of cross-investments

Previous analysis has shown that traders may opt for specific technologies with nojoint productivity advantage as a way to commit themselves to trading jointly, butonly when long-term contracting is infeasible. This paper proves that speciÞcity canalso be optimal (by relaxing the budget-balance constraint) in settings with long-termcontracting. Traders will opt for specificity when one trader makes a cross-investmentand either (1) this cross-investment has a direct externality on the other trader, (2) bothparties invest, or (3) private information is present. The specificity (e.g. from non-salvageable investments, specific assets and technologies, narrow business strategies,and exclusivity restrictions) is equally effective regardless of which trader's alternativetrade payoff is reduced. Specificity supports long-term contracts in a broad rangeof settings - both with and without renegotiation. The theory also offers a novelperspective on franchising and vertical integration.