CASH FLOW PLANNING AND OPTIMIZATION THROUGH GENETIC ALGRORITMS

This article describes an intelligent system for financial planning and cashflow optimization named ICF: Intelligent Cash Flow. ICF is a computational tool for decision support which provides short-term and long-term financial managing strategies, considering financial products of the market. The ICF system makes use of Genetic Algorithms to elaborate cash flow projections which improve the company's profit for a specific period. ICF helps to deal with the complex aspects of cash flow planning: the large number of alternatives to consider, i. e. the mix of investments which offer the higher profit rates over a period; the intensive numerical processing involved; the dynamic changes in the Financial Market (e.g. rates, terms and tax regulations); and the changes in the company's daily financial position. The ICF system integrates two models: the financial and the genetic models. The financial model is used to calculate the cash flow profitability, based on the IDC (Interbank Deposit Certificate), by projecting profits and taxes for each kind of investment, for any term in the considered period. The genetic model, on the other hand, is used to search for cash flow plannings which promote profitability and liquidity. The chromosome of the ICF genetic model consists of n genes. Each gene stands for a day in the considered period and has four fields. The first two identify an investment option and its term; the last two identify a resource taking option and its term. For each analyzed day, only two of these fields are used, which depends whether the operational balance is positive or negative that day.According to the Evolutionary Computation theory, problems such as the optimization of the cash flow are highly epistatic, which means that there is a strong interdependency between genes of the respective representation (for example, the investment on day d depends on the availability of financial resources that day, which can be due to the redemption made on day d-n). Such genes consist of genetic patterns that can be set apart by the crossover operator. In order to deal with the epistasy in this problem, the chromosome has been adapted in way that each gene is represented by its allele and by its locus (position in the chromosome). This kind of representation has the objective to relax the positional rigidity of the genes, increasing the chances of distant interdependent genes to come closer to each other. Thus, genetic patterns with high fitness have more chances to proliferate in forthcoming generations. To manipulate this chromosome structure we have employed an extension of the partially-mapped crossover (PMX) operator proposed by Goldberg, which explores important similarities of value and order simultaneously. The mutation operator applied in the ICF implements a random choice of a gene (day) and the random assignment of a new term and a new type of financial application (investment or loan). The fitness function calculates the liquid returns (profit or tax) of each suggested application/loan for each day in the considered period, projected to the last day of the same. A more satisfactory planning is obtained by finding the maximum return value to this function.ICF has been tested and is currently in use by a Brazilian company. The model manages to find cash flow plannings which present profits, in average, 38% higher during evolution, making evident the importance of a such decision-supporting system. Comparing to the random search, the ICF in average leads to profits 50% higher. Many experiments were made for different periods of the year. The results show that the profitability is obviously affected by the company's operational balance, but it is also strongly influenced by the planning strategy. In this point, the ICF was capable of identifying strategies, with matched operations of application and redemption, which increased the cashbox in days of the flow, in which there was the option of highly profitable investments.

Nontumoral portal vein thrombosis in patients with and without cirrhosis : clinical significance, natural history of varices and efficacy of anticoagulation

A cirrose caracteriza-se por um estado de hipercoagulabilidade. A incidência de trombose da veia porta (TVP) aumenta na cirrose avançada. O impacto da TVP na história natural de cirrose não é claro. A segurança de anticoagulação na cirrose avançada e TVP não é clara e o seu impacto na sobrevida livre de transplante hepático ortotopico (THO) na cirrose avançada e TVP é controverso. Em doentes com trombose da veia porta não-cirrótica e não-tumoral (TVPNCNT) crónica, existe escassa evidência sobre a história natural de varizes esófagogastricas que são habitualmente manejadas como na cirrose. Não existe evidência relativa à eficácia desta estratégia. No primeiro estudo desta tese, uma coorte de 241 doentes com cirrose sem TVP foi seguida prospectivamente e verificamos que a descompensação prévia de cirrose e trombocitopenia foram factores independentes predizentes de desenvolvimento de TVP. A TVP não foi factor predizente independente de descompensações de cirrose ou de sobrevida livre de THO. No segundo estudo, uma análise retrospectiva duma coorte prospectiva de 178 doentes com TVPNCNT crónica, verificamos que o curso natural de varizes esofagogástricas é semelhante ao de doentes com cirrose. No terceiro estudo, uma análise retrospectiva de 80 doentes com cirrose e TVP não-tumoral, constatamos que a anticoagulação, embora não melhorasse a sobrevida global livre de THO, associou-se a melhoria de sobrevida apenas em doentes com cirrose avançada. A anticoagulação aumentou significativamente a recanalização da TVP e deverá ser mantida para prevenir a retrombose. Em conclusão, a descompensação prévia de cirrose e trombocitopenia predizem independentemente, maior risco de desenvolvimento de TVP. A TVP não influenciou independentemente, descompensações de cirrose ou a sobrevida livre de THO. A anticoagulação foi segura e aparenta melhorar a sobrevida livre de THO na cirrose avançada. Na TVPNCNT crónica a mesma estratégia terapêutica como na cirrose associou-se a um baixo risco de hemorragia e mortalidade.Cirrhosis is considered a hipercoagulable state and there is strong evidence that the incidence of nontumoral portal vein thrombosis (PVT) increases in advanced cirrhosis. There is conflicting data regarding the impact of PVT on the natural history of cirrhosis. The safety of anticoagulation especially in patients with advanced cirrhosis and PVT is unclear. The impact of anticoagulation in patients with cirrhosis and PVT on orthotopic liver transplant (OLT) free survival is controversial. There is scant data regarding natural history of gastroesophageal varices in patients with chronic noncirrhotic nontumoral PVT (NCNTPVT), which are usually managed as in cirrhosis. There is no evidence regarding efficacy of this policy. In the first study of this thesis, a cohort of 241 patients with cirrhosis without PVT at study inclusion were evaluated prospectively and we found that prior decompensation of cirrhosis and thrombocytopenia independently predicted development of PVT. PVT did not independently predict higher risk of cirrhosis decompensations and lower OLT free survival. In the second study, a retrospective analysis of a prospective cohort of 178 patients with chronic NCNTPVT, we found that the course of esophagogastric varices appears to be similar to that in cirrhosis. In the third study, a retrospective analysis of 80 patients with cirrhosis with nontumoral PVT, although anticoagulation did not improve OLT free survival of the entire study cohort, it was associated with significantly higher survival in advanced cirrhosis. Anticoagulation was safe, significantly increased PVT recanalization and should be maintained to avoid rethrombosis. In conclusion, prior decompensation of cirrhosis and thrombocytopenia predicted higher risk of developing PVT. PVT did not independently influence cirrhosis decompensations or OLT free survival. Anticoagulation appears to improve OLT free survival only in advanced cirrhosis. In chronic NCNTPVT using the same therapeutic approach as for cirrhosis was associated with a low risk of bleeding and death

Vanishing DC holographic conductivity from a magnetic monopole condensate

We show how to obtain a vanishing DC conductivity in 3-dimensional strongly coupled QFT's using a massive 2-form field in the bulk that satisfies a special kind of boundary condition. The real and imaginary parts of the AC conductivity are evaluated in this holographic setup and we show that the DC conductivity identically vanishes even for an arbitrarily small (though nonzero) value of the 2-form mass in the bulk. We identify the bulk action of the massive 2-form with an effective theory describing a phase in which magnetic monopoles have condensed in the bulk. Our results indicate that a condensate of magnetic monopoles in a 4-dimensional bulk leads to a vanishing DC holographic conductivity in 3-dimensional strongly coupled QFT's.Comment: 24 pages, 2 figures, accepted for publication in JHE

An empirical study of cultural values in total quality management : a Chinese culture-specific model.

Although total quality management (TQM) has been so widely adopted, its theoretical underpinnings remain relatively unexplored as compared to other management theories. A frequently pointed out research gap is on the cultural side of TQM as a human-oriented management philosophy. TQM is known to begin mainly in Japan and the United States. However, the cultural values of the Japanese and the American people are very different. In Japan, the importance of group harmony is stressed, while the Americans mainly value individual creativity and achievements. Even so, companies in these different cultures have succeeded in implementing TQM and have achieved world class performance. It is reasonable to believe that when TQM, as a culture-free system itself, is being implemented in a particular cultural setting, it must accommodate to a certain extent the local culture. That is to say, Japanese-style TQM is obviously different from American-style TQM and a culture-specific TQM indeed exists. As TQM and ISO 9000 have recently become some of the hottest managerial issues in mainland China and the overseas Chinese regions, this empirical study is concerned with the influence of Chinese cultural values on TQM. In particular, the operations of ISO 9000 certified companies in mainland China, Hong Kong, and Taiwan and the cultural values of their Chinese managers were analyzed. Grounded on sociological and psychological theories, quantitative (structural equation modeling) and qualitative (case studies and interviews) research methods were employed to devise a general theoretical model of cultural ii influence on TQM. Furthermore, using Chinese cultural values as a case, the specificities of a Chinese-style TQM were uncovered. The study has not only contributed its modest share towards the theoretical development of TQM but has also paved way for understanding indigenous managerial psychology from a different perspective

The HIV-1 Protein Vpr Targets the Endoribonuclease Dicer for Proteasomal Degradation to Boost Macrophage Infection

The HIV-1 protein Vpr enhances macrophage infection, triggers G2 cell cycle arrest, and targets cells for NK-cell killing. Vpr acts through the CRL4DCAF1 ubiquitin ligase complex to cause G2 arrest and trigger expression of NK ligands. Corresponding ubiquitination targets have not been identified. UNG2 and SMUG1 are the only known substrates for Vpr-directed depletion through CRL4DCAF1. Here we identify the endoribonuclease Dicer as a target of HIV-1 Vpr-directed proteasomal degradation through CRL4DCAF1. We show that HIV-1 Vpr inhibits short hairpin RNA function as expected upon reduction of Dicer levels. Dicer inhibits HIV-1 replication in T cells. We demonstrate that Dicer also restricts HIV-1 replication in human monocyte-derived macrophages (MDM) and that reducing Dicer expression in MDMs enhances HIV-1 infection in a Vpr-dependent manner. Our results support a model in which Vpr complexes with human Dicer to boost its interaction with the CRL4DCAF1 ubiquitin ligase complex and its subsequent degradation