ABSTRACT. In fruit tree breeding, selection indices are used to identify the genotypes that combine desirable commercial and non-commercial characteristics. As Theobroma grandiflorum is generally cultivated in agroforestry systems (AFS), there is a need to develop cultivars that are adapted to such environments. In this study, the objective was to select the most promising genotypes for their future use in AFS based on the additive index, a pioneering method for this crop. The trial was carried out for 12 years in an agroforestry system in the municipality of Tomé-Açu, Pará State, Brazil. The 16 evaluated clones were completely randomised with a variable number of repetitions. The average number of fruits produced as well as the morpho-agronomic characteristics of the fruits were analysed. Mixed linear models were used to estimate the components of variance and predict the genotypic values. The genetic correlation between the variables was estimated, and the selection of genotypes was based on the additive index, with a positive orientation of all variables except the thickness of the fruit shells and the weight of the fruits. Clones 42, 44, 46, 47, 57, 61, and 64 performed well for all the analysed variables, resulting in a selection gain of 7.3% and low incidence rates of witches’ broom disease. These genotypes can be made available to producers in the form of clones for use in AFS and can further be included in future hybridisations in T. grandiflorum breeding. ABSTRACT breeding noncommercial non AFS, , (AFS) environments study index crop 1 ToméAçu, ToméAçu Tomé Açu, Açu Tomé-Açu State Brazil repetitions morphoagronomic morpho agronomic values estimated 42 44 46 47 57 61 6 73 7 3 7.3 witches disease T (AFS 4 5 7.

ABSTRACT At the moment one of the main environmental problems is the existence of pollutants in the bodies of water due to the emission of polluted efluentes mainly for heavy metals. These compounds are characterized to be persistent and not biodegradable, of there the importance of their elimination. The interior part of the bay of Santiago from Cuba is the polluted due to the characteristic hydro geographical that presents. In this study investigative works related with the bioadsorventes no conventional employees were revised at world level for the mitigation of heavy metals, which possess advantages on the conventional ones to be highly available, to be of low costs and degradable. Of the bibliographical revision it could be proven that among the no conventional methods they are the biopolímeros application, the biorremediación and the use of agroindustrial residuals. The search was focused in the agroindustrial residuals to be the most abundant under our conditions. Of the employees the shells of Yucca are with more tendencies, of banana, of citric, it erases it of coffee, egg shell and the cane of sugar. The present work has as objective to present a revision of the main bioadsorbentes of low costs more employees at world level in the mitigation of the heavy metals, of there the selection of the most feasible for its use in the waters of the bay of Santiago from Cuba under the current conditions.

RESUMEN Actualmente uno de los principales problemas medioambientales es la existencia de contaminantes en los cuerpos de agua debido a la emisión de efluentes contaminados principalmente por metales pesados. Estos compuestos se caracterizan por ser persistentes y no biodegradables, de ahí la importancia de su eliminación. La parte interior de la bahía de Santiago de Cuba es la más contaminada debido a las características hidrogeográficas que presenta. En este estudio se revisaron trabajos investigativos relacionados con los bioadsorbentes no convencionales empleados a nivel mundial para la mitigación de metales pesados, los cuales poseen ventajas sobre los convencionales por estar altamente disponibles, ser de bajo costos y degradables. De la revisión bibliográfica se pudo comprobar que entre los métodos no convencionales se encuentran la aplicación de biopolímeros, la biorremediación y el uso de residuos agroindustriales. Se enfocó la búsqueda en los residuos agroindustriales por ser los más abundantes en nuestras condiciones. De los empleados con mayores tendencias están las cáscaras de yuca, de plátano, de cítricos, la borra de café, cáscara de huevo y la caña de azúcar. El presente trabajo tiene como objetivo presentar una revisión de los principales bioadsorbentes de bajo costos más empleados a nivel mundial en la mitigación de los metales pesados, de ahí la selección del más factible para su uso en las aguas de la bahía de Santiago de Cuba en las condiciones actuales.

RESUMEN Muchos invertebrados marinos sésiles tienen ciclos de vida que involucran el desarrollo de larvas que se asientan en sustratos específicos iniciando su metamorfosis a formas juveniles. Aunque es conocido que biopelículas bacterianas participan en este proceso, las señales químicas responsables hasta ahora se empiezan a investigar. Aquí evaluamos el papel de biofilms bacterianos y sus extractos de moléculas de señalización de "Quorum Sensing' (QSSM) sobre la quimiotaxis y el asentamiento larvario en Hydractinia symbiolongicarpus, un hidrozoario que crece sobre conchas de gastrópodos ocupadas por cangrejos ermitaños. Nosotros aislamos e identificamos taxonómicamente por secuenciación de rDNA 16S 14 cepas bacterianas de conchas con H. symbiolongicarpus. Tres de ellas, Shigella flexneri, Microbacterium liquefaciens, and Kocuria erythromyxa, mostraron producción de QSSMs usando biosensores que detectan N-acil-L-homoserin lactonas. Biopelículas y extractos de QSSMs de estas bacterias mostraron efectos quimiotácticos sobre larvas de H. symbiolongicarpus, efecto no observado en ensayos con cepas mutantes de E. coli y Chromobacterium violaceum que son incapaces de producir QSSMs. Las biopelículas y sus extractos indujeron adhesión larvaria sobre superficies, aunque solamente el 1 % de las larvas asentadas hicieron metamorfosis hacia pólipo primario, en contraste con 99 % de larvas incubadas con CsCl, un inductor artificial de asentamiento y metamorfosis. Estas observaciones sugieren que QSSMs de biopelículas bacterianas participan en la selección de sustrato de H. symbiolongicarpus, induciendo quimiotaxis y asentamiento de sus larvas. También sugieren que el asentamiento en cnidarios tiene dos procesos, adhesión y metamorfosis, donde las QSSMs participarían en el primero, pero no en el segundo.

ABSTRACT Many sessile marine invertebrates have life cycles involving the development of larvae that settle on specific substrates to initiate metamorphosis to juvenile forms. Although is recognized that bacterial biofilms play a role in this process, the responsible chemical cues are beginning to be investigated. Here, we tested the role of substrate-specific bacteria biofilms and their Quorum Sensing Signaling Molecule (QSSM) extracts on chemotaxis and settlement of larvae from Hydractinia symbiolongicarpus, a hydroid that grows on gastropod shells occupied by hermit crabs. We isolated and taxonomically identified by 16S rDNA sequencing, 14 bacterial strains from shells having H. symbiolongicarpus. Three isolates, Shigella flexneri, Microbacterium liquefaciens, and Kocuria erythromyxa, were identified to produce QSSMs using biosensors detecting N-acyl-L-homoserine lactones. Multispecies biofilms and QSSM extracts from these bacteria showed a positive chemotactic effect on H. symbiolongicarpus larvae, a phenomenon not observed with mutant strains of E. coli and Chromobacterium violaceum that are unable to produce QSSMs. These biofilms and QSSMs extracts induced high rates of larval attachment, although only 1 % of the attached larvae metamorphosed to primary polyps, in contrast to 99 % of larvae incubated with CsCl, an artificial inductor of attachment and metamorphosis. These observations suggest that bacterial QSSMs participate in H. symbiolongicarpus substrate selection by inducing larval chemotaxis and attachment. Furthermore, they support the notion that settlement in cnidarians is decoupled into two processes, attachment to the substrate and metamorphosis to a primary polyp, where QSSMs likely participate in the former but not in the latter.

Abstract Mucoadhesive nanoparticles are particularly interesting for delivery through nasal or pulmonary routes, as an approach to overcome the mucociliary clearance. Moreover, these nanoparticles are attractive for peptide and protein delivery, particularly for insulin to treat diabetes, as an alternative to conventional parenteral administration. Thus, chitosan, a cationic mucoadhesive polysaccharide found in shells of crustaceans, and the negatively-charged dextran sulfate are able to form nanoparticles through ionic condensation, representing a potential insulin carrier. Herein, chitosan/dextran sulfate nanoparticles at various ratios were prepared for insulin loading. Formulations were characterized for particle size, zeta potential, encapsulation efficiency, scanning electron microscopy, differential scanning calorimetry, and in vitro drug release. Moreover, the interaction with mucin and the cytotoxicity against a lung cell line were studied, which altogether have not been addressed before. Results evidenced that a proper selection of polyelectrolytes is necessary for smaller particle size formation and also the composition and zeta potential impact encapsulation efficiency, which is benefited by the positive charge of chitosan. Insulin remained stable after encapsulation as evidenced by calorimetric assays, and was released in a sustained manner in the first 10 h. Positively-charged nanoparticles based on chitosan/dextran-sulfate at the ratio of 6:4 successfully interacted with mucin, which is a prerequisite for delivery to mucus-containing tissues. Finally, insulin-loaded nanoparticles displayed no cytotoxicity effect against lung cells at tested concentrations, suggesting the potential for further in vivo studies.

Abstract The aim of this study was to characterize the pattern of gastropod shell occupation in the field and selection of shell size and type under laboratory conditions by the hermit crab Pagurus criniticornis (Dana, 1852), inhabiting the infralittoral area of Anchieta Island, São Paulo, Brazil. Hermit crabs were obtained monthly during 1999 by SCUBA diving. For experiments under laboratory conditions, samplings were performed in 2002. The hermit crabs occupied 16 species of gastropods shells. Cerithium atratum (Born, 1778) was the most occupied shell (89.31%), followed by Morula nodulosa (4.73%) (Adams, 1845). No difference was observed in the pattern of occupation between males and females. The equations that best demonstrated the relationship between hermit crabs and their shells were those that involved Shell Wet Weight (SWW) and Shell Internal Volume (SIV). The laboratory experiments were in accordance to the pattern of occupation observed in the field; the mean value of SAI (Shell Adequacy Index) recorded to the population studied was 1.13 with a trend to increase this value in the last size classes. The results obtained corroborate with the hypothesis of the occupation process of shells governed not only by availability of shells, but also by its architecture. In addition, the shell stock in the area is one another important condition related to the exhibited pattern of shell occupation by P. criniticornis, and allows the stable coexistence among the island assemblage. The pattern of occupation observed promotes a high reproductive profile for the population studied, maximizing the populational growth.

Abstract The goal of this study was to identify patterns of shell occupation by different species of hermit crabs from the southern Brazilian coast. In total, 644 individuals were collected, represented by six hermit species. Isocheles sawayai Forest & Saint Laurent, 1968 showed the highest abundance, with 575 individuals, followed by Loxopagurus loxochelis (Moreira, 1901) (n = 56). The other species were Petrochirus diogenes (Linnaeus, 1758), Dardanus insignis (Saussure, 1858), Pagurus exilis (Benedict, 1892) and Pagurus leptonyx Forest & Saint Laurent, 1968. Loxopagurus loxochelis was found associated with shells of 12 gastropod species, with 75% of males occupying shells of Olivancilaria urceus (Roding, 1798) and 78% of females inhabiting shells of Semicassis granulata (Born, 1778). Shells of Semicassis granulata were the lightest of all gastropod shells, demonstrating differential resource utilization. Additionally, I. sawayai occupied shells of 10 species, highlighting Stramonita haemastoma (Linnaeus, 1767) with the highest occupation percentage in all demographic classes, confirming a pattern of occupation with a strong relationship to the availability of the resource. The comparison of our results with those of other studies corroborated the influence of region and gastropod diversity on gastropod shell occupation.

This paper discusses the mine planning process for Letseng diamond mine in the Kingdom of Lesotho, in conjunction with the various software packages used during the process. The major pillars of the long-term mine planning process at Letseng are pit optimization followed by pit design and scheduling. Letseng uses Gemcom Whittle and GEMS for pit optimization and design and Runge XPAC for scheduling. The output of the mine planning process results in the generation of published mineral reserves and provides input into the Letseng overall business plan. The process of defining the key inputs for the entire mine planning process is discussed, which covers: ► Slope design as an input ► Diamond price inputs ► Operating and capital cost inputs ► Generation of pit shells ► Selection of an optimum pit shell and interim cutbacks using operational scenarios ► Sensitivity analysis on the selected optimum pit shell. ► Slope design criteria in the detailed design ► Split shell vs concentric pit design ► Practical mining widths to determine cutback design ► Pit design process in the GEMS software package. ► Development of scheduling scenarios in the XPAC software package ► Planning through mining production bottlenecks. ► Company-level NPV model ► Comparing scenarios and input of the different schedule scenarios into the company NPV model.

This paper presents the general characteristics of this research aimed to studying the mechanisms used to collect wood by hunter-gatherers, living on the northern shore of San Matías gulf during the last six thousand years. The collected wood was used to build fires where these groups would crack the shells of the collected shellfish. This paper also shows a synthesis of the first results obtained in three archaeological localities. The results obtained through the charcoal analysis will be discussed taking into account the new data available through pollen analysis. The aim is to evaluate the mechanisms applied to the collection of firewood used during the environmental conditions depicted through the palynological techniques. These mechanisms range from a "random gathering" to a thorough "selection" of the wood types according to the properties that make them optimal to be used as fuel.

En este trabajo se indagan los mecanismos de recolección de leñas destinadas al encendido de fuegos, utilizadas por los cazadores-recolectores que habitaron la costa norte del golfo San Matías (Río Negro) durante el Holoceno Medio-Tardío. Se sintetizan los primeros resultados obtenidos a partir de análisis antracológicos de carbones arqueológicos recuperados en concheros ubicados en tres de las localidades arqueológicas que componen dicha investigación. Luego, a la luz de los datos aportados por nuevas líneas de evidencia como la palinología, se replantean hipótesis previas y se presentan los datos a ser discutidos en el escenario ambiental delineado a partir de los análisis polínicos. Por último, se evalúa qué tipo de estrategias -en un rango que se extiende desde la recolección azarosa hasta la selección de un determinado taxón- utilizaron estos grupos para la recolección de combustible vegetal.

Ethnographic accounts often describe the long shell bead necklaces worn by Patagonian canoe indians. Numerous exemplars of these artefacts are curated in museums around the world. Whilst the decorative function of these necklaces is generally taken for granted, little is known about the ways in which they were manufactured. In order to expand our knowledge of these techniques, twelve necklaces from the Salesian Museum in Punta Arenas and a further necklace from the Regional Museum of Magallanes were studied focusing on the manufacturing techniques employed and the ways in which they were used. The beads evidence a careful selection of shells, their modification according to a particular aesthetic, and recurrently employed drilling techniques. Also recorded are the types of fibres used for cordage and related twinning techniques. We also observe occasional painting/colouring of some of them. The study demonstrates outstanding technical complexity coupled with careful craftsmanship in the production of these ornaments, offering new insights to understand the technical systems of indigens

Los relatos etnográficos describen a menudo los largos collares compuestos de pequeñas conchas que llevaban los canoeros de Patagonia. Se conservan numerosos ejemplares de éstos en varios museos del mundo. Si la función decorativa de estos collares se supone obviamente, pocos datos están disponibles en cuanto a su fabricación. Para enriquecer nuestro conocimiento de las técnicas de los canoeros modernos, emprendimos el estudio de 13 de estos collares. Doce están conservados en el Museo Salesiano de Punta Arenas y un collar en el Museo Regional de Magallanes en la misma ciudad. El estudio es tecnológico, interesándose en los métodos de fabricación y utilización de estos collares. Las perlas muestran una selección precisa de la concha, modificaciones estéticas de la concha y técnicas de perforación recurrentes. Se observaron también la materia de las fibras y las técnicas de trenzado. Los collares fueron a veces coloreados. El estudio muestra una gran complejidad técnica y todo el cuidado para la fabricación de estos objetos de adorno. Aporta un nuevo elemento a la comprensión de los sistemas técnicos de los indígenas

The studied Pagurus hermit crabs (Decapoda: Anomura: Paguridae) are macroinvertebrates from the marine rocky shore from the central coast of Peru. Every fifteen days between August to October 2000 (winter and spring), the morphometric parameters, sexual proportion and selection of gastropod shells of Pagurus villosus (Nicolet, 1849), P. edwardsi (Dana, 1852) and P. perlatus (H. Milne Edwards 1848) collected at San Francisco (SFB) and Los Enanos (LEB) beach, Bay of Ancon (11° 44,5' LS, 77°6' LW), Lima, Peru, were evaluated. Only P. perlatus from PLE separated from a sex ratio 1:1, representing the females a 74.46 %. The values of five morphometric parameters in mm: cephalothoracic length (CL), right forceps length (RFL), left forceps length (LFL), maximum right forceps width (MRFW) and cephalothoracic width (CW) were higher in males than in females of P. villosus and P. edwardsi. The exception was P. perlatus which presented an opposite pattern in LEB. The three species of Pagurus presented an observed preference to shells of the following gastropods: Nassarius dentifer (Powys, 1835), N. gayi (Kiener 1835), Nodilittorina peruviana (Lamarck 1822), Stramonita haemastoma (Linnaeus 1767), Tegula atra (Lesson 1830), T. euryomphala (Jones 1844) and Xantochorus buxea (Broderip 1833)

Los cangrejos "ermitaños" estudiados del género Pagurus (Decapoda: Anomura: Paguridae) son macroinvertebrados del intermareal rocoso marino de la costa central del Perú. Se evaluaron quincenalmente, desde agosto a octubre del 2000 (invierno-primavera) tres especies: Pagurus villosus (Nicolet, 1849), P. edwardsi (Dana, 1852) y P. perlatus (H. Milne Edwards 1848) recolectados en las playas San Francisco (PSF) y Los Enanos (PLE), de la Bahía de Ancón (11° 44,5' LS, 77°6' LW), Lima, Perú, parámetros morfométricos, proporción sexual y de selectividad a conchillas de gasterópodos. Sólo P. perlatus, de PLE, se apartó de la proporción sexual 1:1, representando las hembras un 74,46 %. Los cinco parámetros morfométricos están expresados en mm: longitud del cefalotórax (LC), longitud de quela derecha (LQD), longitud de quela izquierda (LQI), ancho máximo de quela derecha (AMQD) y ancho del cefalotórax (AC) fueron mayores en machos que en hembras para P. villosus y P. edwardsi, a excepción de P. perlatus que presentó un patrón opuesto en PLE. Las tres especies presentaron preferencia a las conchillas de los siguientes gasterópodos: Nassarius dentifer (Powys 1835), N. gayi (Kiener 1835), Nodilittorina peruviana (Lamarck 1822), Stramonita haemastoma (Linnaeus 1767), Tegula atra (Lesson 1830), T. euryomphala (Jones 1844) y Xantochorus buxea (Broderip 1833)

Shell selection by the hermit crab Paguristes tortugae Schmitt, 1933 from Anchieta Island (Brazil) was analyzed using the six most frequently occupied shell species in the field and taking into account the sexual condition of the individuals, the shell size and the shell species. The experiments were conducted under laboratory conditions and the shell species preference was estimated on the basis of the frequency that each species was chosen by the individuals. The preferred shell species and size were determined by regression analysis. The highest correlation coefficients were obtained for the relations between the hermit dimensions and shell dry weight. The ovigerous females preferred shells with larger internal volume: Leucozonia nassa (Gmelin, 1791) and Cerithium atratum (Born, 1778). In the experiment of shell size, males preferred heavier shells whereas females selected the shape characteristics of the shell, such as the aperture and the internal volume, which are probably related to the growth and offspring guarantee, respectively. In general, and independent of sex condition, P. tortugae showed significant selection among all shells utilized. The results suggest that shell selection by P. tortugae involves sexual and reproductive condition preferences.

The relative abundance of "el loco", Concholepas concholepas, and the possible causes of its variability in cultural shell deposits dated from the Early-Middle Holocene of Los Vilos littoral (31º55'S, 71º32'W) were studied. The samples were obtained in archaeologic excavations from five sites. These samples were dated with C14: Punta Purgatorio (LV079: 10.040 ± 70 years before present, y.b.p.), Caleta Ñagué (LV098: 10.120 ± 80 y.b.p.), Dunas de Agua Amarilla (LV166: 6.700 ± 60 y.b.p.), Borde Norte de Quebrada de Quereo (LV036: 6.030 ± 80 y.b.p.) and Fundo Agua Amarilla (LV099: 5.480 ± 70 y.b.p.). These gastropod shells correspond to juvenile and young adult specimens, whose lengths oscillate between 20 and 145 mm. The wide range of sizes found indicates that collectors did not make mollusk selection by sizes during the captures. The majority of these specimens are of a size longer than 50 mm. This latter length corresponds to first maturity size found in current Concholepas concholepas populations. The abundance of this species in the shellmidden is greater in the most recent sites: 46,200 specimens in LV166 and 4,185,000 in LV036. The variability in the records substantiates the hypothesis that the principal cause in the observed changes was originated in palaeoclimatic changes that affected directly the ecologic characteristics of the region, and influenced, indirectly, the species extraction

Se estudió la abundancia relativa del loco, Concholepas concholepas, y las causas posibles de su variabilidad en los conchales culturales más antiguos del Holoceno Temprano-Medio del litoral de Los Vilos (31º55'S, 71º32'W). Las muestras se obtuvieron en excavaciones arqueológicas de cinco sitios y se dataron con C14: Punta Purgatorio (LV079: 10.040 ± 70 años antes del presente, a.a.p.), Caleta Ñagué (LV098: 10.120 ± 80 a.a.p.), Dunas de Agua Amarilla (LV166: 6.700 ± 60 a.a.p.), Borde Norte de Quebrada de Quereo (LV036, 6.030 ± 80 a.a.p.) y Fundo Agua Amarilla (LV099: 5.480 ± 70 a.a.p.). Las conchas corresponden a ejemplares juveniles y adultos jóvenes, cuyas tallas varían entre 20 y 145 mm. Este amplio rango de tamaño refleja que los recolectores que formaron los conchales extrajeron los moluscos sin selección de tallas. La mayoría de los especímenes son de talla superior a 50 mm, longitud que corresponde a la talla de primera madurez en las poblaciones de locos actuales. La abundancia de esta especie en los conchales es mayor en los sitios más recientes: 46.200 ejemplares en LV166 y 4.185.000 en LV036. La variabilidad observada en los registros sustenta la hipótesis que éstos fueron motivados por cambios paleoclimáticos que afectaron directamente las características ecológicas de la región, las que influyeron, indirectamente, en la extracción de las especies

Espécies de ermitões coexistentes podem realizar interações competitivas por conchas e microambientes, principalmente quando a disponibilidade de conchas está relacionada aos microambientes. Três espécies de ermitões do gênero Clibanarius (C. antillensis, C. sclopetarius e C. vittatus) coexistem na região entremarés da Ilha de Pernambuco, região do Araçá, Canal de São Sebastião, Sudeste brasileiro. Este estudo avaliou a preferência dos ermitões por quatro tipos de substrato (costão, seixos, areia e lodo) utilizados por eles na natureza em tratamentos alopátricos (uma espécie) e simpátricos (três espécies) em situações simuladas de marés alta e baixa. A preferência por tipos de substrato não variou entre as simulações de marés alta e baixa. Na maré baixa, os ermitões deslocaram-se para buracos e fendas ou enterraram-se no lodo. A seleção de substratos pode explicar o padrão de uso de substratos na natureza apenas para C. vittatus. Clibanarius antillensis e C. sclopetarius apresentaram maiores similaridades na seleção de substratos no tratamento simpátrico e no uso na natureza que no tratamento alopátrico, indicando influência positiva (dependência) da presença de uma espécie em função da outra. O uso de substratos subótimos no campo, principalmente por C. antillensis, pode ter sido causado por outros fatores, como suas baixas tolerâncias à dessecação. Se houver competição por substratos entre as três espécies, ela será mais intensa entre C. sclopetarius e C. vittatus, dada a maior sobreposição na preferência por substratos entre essas espécies que entre elas e C. antillensis.

Coexisting hermit crabs may competitively interact for shells and microhabitats, mainly when shell availability is habitat-related. Three species of Clibanarius (C. antillensis, C. sclopetarius, and C. vittatus) coexist in the intertidal region of Pernambuco Islet, Araçá Region, São Sebastião Channel, southeastern Brazil. This study evaluated crab preferences for four substrate types used by these species in nature (rocky shore, pebbles, sand, and mud) in allopatric (single species) and sympatric (three species) treatments in simulations of high tide and low tide. The substrate preference of the three hermit crabs did not vary between low and high tide situations. At low tide the crabs either moved into holes in the highly complex rocky substrate or buried themselves in mud. Substrate selection may explain the patterns of substrate use in nature only for C. vittatus. Clibanarius antillensis and C. sclopetarius showed closer similarities in the pattern of substrate selection in the sympatric treatment with the substrate use in nature than in allopatric treatment, indicating a positive influence (dependence) of the presence of one species on the presence of another. Use of sub-optimal substrates, mainly by C. antillensis, may be caused by other factors such as its low desiccation tolerances. If competition for space takes place among these species, it would be more intense between C. sclopetarius and C. vittatus given their higher overlap in substrate preference than between them and C. antillensis.

Com o crescimento das aplicações de Sistemas Especialistas (SE), surge a necessidade de avaliar seu valor e assegurar o sucesso da implantação. Este estudo identificou e testou empiricamente oito variáveis principais apresentadas na literatura como determinantes do êxito de um SE, neste caso medido em termos de satisfação do usuário. O Centro de Projeto de Sistemas Especialistas da Divisão de Manufatura da IBM, coletou dados de 69 gerentes de projeto para dar suporte ao estudo. Os resultados confirmam claramente as hipóteses e sugerem a necessidade dos gerentes de projetos de SE dedicarem especial atenção aos determinantes do êxito da implantação. O êxito do SE está diretamente relacionado à qualificação dos que o desenvolvem, à qualidade dos shells utilizados, às características da finalidade da aplicação e ao grau de envolvimento do usuário no desenvolvimento do SE, conforme definidos neste estudo. Para propósitos de investigação, os itens que compõem cada uma dessas variáveis foram correlacionados com os itens componentes da variável satisfação do usuário. Com base nesses resultados, diversas recomendações são propostas aos gerentes de projetos de SE visando o aumento da probabilidade de êxito do projeto: incluir o grau de dificuldade do problema como critério para seleção de aplicação de SE; aumento de treinamento das pessoas que desenvolvem o SE para melhorar suas qualificações; definir as atitudes e expectativas do usuário final em relação ao SE; melhorar a seleção dos especialistas; melhorar o entendimento sobre o impacto do SE no trabalho do usuário final; restringir a aquisição de shells baseando-se em um conjunto proposto de critérios; e assegurar a adequação das técnicas e ferramentas de desenvolvimento de SE ao problema abordado.

As the widespread use and company dependency on Expert Systems increase, so does the need to assess their value and to ensure implementation success. This study identified and empirically tested eight major variables proposed in the literature as determinants of ES success, in this case measured in terms of user satisfaction. IBM's Corporate Manufacturing Expert Systems Project Center collected information from 69 project managers to support the study. The results clearly support the hypothesized relationships and suggest the need for ES project managers to pay special attention to these determinants of ES implementation success. ES success is directly related to the quality of developers and of the ES shells used, end-user characteristics and degree of user involvement in ES development, as each has been defined in this study. For exploratory purposes, the component items for each of these major variables were correlated with the components of user satisfaction. Based on the results, several recommendations are proposed for ES project managers to enhance the likelihood of project success, including: adding problem difficulty as a criterion for ES application selection; increasing ES developer training to improve their people skills, ability to model and to use a systems approach in solving business problems; shaping end-user attitudes and expectations regarding ES; improving the selection of domain experts; more thoroughly understanding the ES impact on end-user jobs; restricting the acquisition of ES shells based on a proposed set of criteria; and ensuring a proper match of ES development techniques and tools to the business problem at hand.