Probabilistic Graphical Models on Multi-Core CPUs using Java 8

In this paper, we discuss software design issues related to the development of parallel computational intelligence algorithms on multi-core CPUs, using the new Java 8 functional programming features. In particular, we focus on probabilistic graphical models (PGMs) and present the parallelisation of a collection of algorithms that deal with inference and learning of PGMs from data. Namely, maximum likelihood estimation, importance sampling, and greedy search for solving combinatorial optimisation problems. Through these concrete examples, we tackle the problem of defining efficient data structures for PGMs and parallel processing of same-size batches of data sets using Java 8 features. We also provide straightforward techniques to code parallel algorithms that seamlessly exploit multi-core processors. The experimental analysis, carried out using our open source AMIDST (Analysis of MassIve Data STreams) Java toolbox, shows the merits of the proposed solutions.Comment: Pre-print version of the paper presented in the special issue on Computational Intelligence Software at IEEE Computational Intelligence Magazine journa

Poor household participation in payments for environmental services in Nicaragua and Colombia

We evaluate the extent to which poor households are able to participate in Payments for Environmental Services (PES) scheme using data from a PES scheme implemented at two sites in Latin America. This allows us to compare environmental and livelihood impacts of PES across regions with different agronomic and socio-economic characteristics. In particular, one of our sites is composed almost entirely of poor or extremely poor households, while the other has households ranging from extremely poor to very well off. The results show that poorer households are in fact able to participate—indeed, by some measures they participated to a greater extent than better-off households. Moreover, their participation was not limited to the simpler, least expensive options. Extremely poor households had a somewhat greater difficulty in participating, but even in their case the difference is solely a relative one. Transaction costs may be greater obstacles to the participation of poorer households than household-specific constraints.Payments for environmental services, PES, poverty, silvopastoral

Constructing three emotion knowledge tests from the invariant measurement approach

Background. Psychological constructionist models like the Conceptual Act Theory (CAT) postulate that complex states such as emotions are composed of basic psychological ingredients that are more clearly respected by the brain than basic emotions. The objective of this study was the construction and initial validation of Emotion Knowledge measures from the CAT frame by means of an invariant measurement approach, the Rasch Model (RM). Psychological distance theory was used to inform item generation. Methods. Three EK testsemotion vocabulary (EV), close emotional situations (CES) and far emotional situations (FES)were constructed and tested with the RM in a community sample of 100 females and 100 males (age range: 18-65), both separately and conjointly. Results. It was corroborated that data-RM fit was sufficient. Then, the effect of type of test and emotion on Rasch-modelled item difficulty was tested. Significant effects of emotion on EK item difficulty were found, but the only statistically significant difference was that between "happiness" and the remaining emotions; neither type of test, nor interaction effects on EK item difficulty were statistically significant. The testing of gender differences was carried out after corroborating that differential item functioning (DIF) would not be a plausible alternative hypothesis for the results. No statistically significant sex-related differences were found out in EV, CES, FES, or total EK. However, the sign of d indicate that female participants were consistently better than male ones, a result that will be of interest for future meta-analyses. Discussion. The three EK tests are ready to be used as components of a higher-level measurement process.Fil: Delgado, Ana R.. Universidad de Salamanca; EspañaFil: Prieto, Gerardo. Universidad de Salamanca; EspañaFil: Burin, Debora Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Psicología; Argentin

Indirect ELISA for Detection of Fascioliasis IgG Antibodies in Human Sera

Currently, coprological examination based on egg detection in stool samples is used as the most ideal standard for the diagnosis of human fascioliasis. However, this method has been proven not to be adequate when being employed in the acute phase of the disease, and presents a poor sensitivity during the chronic phase. Serodiagnosis has become an excellent alternative to coprological examination in efforts to combat the effects of fascioliasis on human and animal health. Human fascioliasis is usually recognized as an infection of the bile ducts and liver caused by Fasciola hepatica, known to affect over 2 million humans. In this research, Indirect Enzyme-linked Immunosorbent Assay (ELISA) was performed to discern between positive and negative IgG antibody titers in sera in collaboration with a lab in Peru. A batch of approximately 325 samples of human sera of endemic Fasciola hepatica from regions in Peru was gathered and sent to the laboratory in order to be examined with the method explained in the following paragraph. In the search for a test for the diagnosis of fascioliasis on humans, indirect ELISA started to be employed in order to determine positive and negative values. In the indirect ELISA test, the sample antibody is sandwiched between the antigen coated on the plate and an enzyme-labeled, anti-species globulin conjugate. The addition of an enzyme substrate-chromogen reagent causes color to develop. This color is directly proportional to the amount of bound sample antibody. The more antibody present in the sample, the stronger the color development in the test wells. Positive samples presented a very strong optical density value, while negative samples were clear or low optical density value, measured with the aid of a spectrophotometer

Farm size and nonparametric efficiency measurements for coffee farms in Vietnam

We study the efficiency of smallholder coffee farms in Vietnam. Data from a 2004 survey of farms in two districts in Dak Lak Province are used in a two-step analysis. In the first step, technical and cost efficiency measures are calculated using DEA. In the second step, Tobit regressions are used to identify factors correlated with technical and cost inefficiency. Results indicate that small farms were less efficient than large farms. Inefficiencies observed on small farms appear to be related, in part, to the scale of investments in irrigation infrastructure.Farm Management,