The Value of Private Information within Evolving Groups

This note offers an analytical framework aimed at explaining how individual agents purposefully act with the goal of managing the value of their information sets. Agents undertake a process of private accumulation of information, which takes into account the non-rival nature of this peculiar entity. Non rivalry introduces an externality that might trigger long-term endogenous fluctuations. The dynamics of interaction, namely the possibility of entering or exiting the group to which the individuals belong, wil l determine time trajectories for the information flows that are unique for the specific conditions of interaction that are being considered at a given momentEste artigo apresenta uma estrutura analítica que tem por objetivo explicar como é que os agentes individuais atuam, de modo intencional, com o propósito de gerir o valor da informação que detêm. Os agentes prosseguem um processo de acumulação privada de informação, o qual toma em consideração a natureza não rival desta entidade que detém características específicas. A não rivalidade introduz uma externalidade que pode despoletar flutuações endógenas de longo prazo. A dinâmica de interação, nomeadamente a possibilidade de entrar ou sair do grupo a que os indivíduos pertencem, vai determinar a formação de trajetórias no tempo para os fluxos de informação, as quais são únicas para as condições particulares de interação que estão a ser consideradas num determinado momento.

Social wasps of two Cerrado localities in the northeast of Maranhão state, Brazil (Hymenoptera, Vespidae, Polistinae)

Social wasps of two Cerrado localities in the northeast of Maranhão state, Brazil (Hymenoptera, Vespidae, Polistinae). Results are presented of a survey of social wasps from two savanna localities 30 km apart from each other in the northeastern part of the Brazilian state of Maranhão, Brazil: village of Bom Jesus (municipality of Urbano Santos) and village of Tabocas (municipality of Barreirinhas). Two hundred and twenty-seven nests of 31 species of 13 genera were found and mapped. Polybia rejecta was the species with the largest average density of colonies/ha in both areas. The similarity (Jaccard's index) between the Tabocas and Bom Jesus faunas was 41.9%. Twenty-seven species of plants were utilized as nesting substrate. In Tabocas, Qualea parviflora Mart. (Vochysiaceae) trees were used as substrate by 30.3% of the wasp colonies. In Bom Jesus, the vast majority of colonies (27.9%) were found in a secondary vegetation type, the so-called carrasco, indicator of vegetation change. The number of social wasp species recorded in this study is similar to others obtained in several areas of Cerrado vegetation in Brazil. Nine species are new to Maranhão, and Mischocyttarus cerberus had its distribution confirmed, increasing to 58 the number of species known to occur in that state.

Organic matter in upwelling off northern Peru, november 1977

Analiza la cantidad de carbon organico y nitrogeno en las costas del norte del Perú en noviembre de 1977

Local-scale spatial variation in diversity of social wasps in an Amazonian rain forest in Caxiuanã, Pará, Brazil (Hymenoptera, Vespidae, Polistinae)

Polistine wasps are important in Neotropical ecosystems due to their ubiquity and diversity. Inventories have not adequately considered spatial attributes of collected specimens. Spatial data on biodiversity are important for study and mitigation of anthropogenic impacts over natural ecosystems and for protecting species. We described and analyzed local-scale spatial patterns of collecting records of wasp species, as well as spatial variation of diversity descriptors in a 2500-hectare area of an Amazon forest in Brazil. Rare species comprised the largest fraction of the fauna. Close range spatial effects were detected for most of the more common species, with clustering of presence-data at short distances. Larger spatial lag effects could also be identified in some species, constituting probably cases of exogenous autocorrelation and candidates for explanations based on environmental factors. In a few cases, significant or near significant correlations were found between five species (of Agelaia, Angiopolybia, and Mischocyttarus) and three studied environmental variables: distance to nearest stream, terrain altitude, and the type of forest canopy. However, association between these factors and biodiversity variables were generally low. When used as predictors of polistine richness in a linear multiple regression, only the coefficient for the forest canopy variable resulted significant. Some level of prediction of wasp diversity variables can be attained based on environmental variables, especially vegetation structure. Large-scale landscape and regional studies should be scheduled to address this issue.

Guia de identificação dos ninhos de vespas sociais (Hymenoptera, Vespidae, Polistinae) na Reserva Ducke, Manaus, Amazonas, Brasil

Vespidae sociais utilizam principalmente material vegetal para a elaboração de seus ninhos. Embora existam alguns estudos referentes à fauna de vespas na região Amazônica, nenhum trabalho trata exclusivamente dos ninhos. Além disso, nas coleções biológicas poucos são os ninhos tombados, devido principalmente à fragilidade e difícil conservação dos mesmos. O objetivo desse trabalho foi o conhecimento de alguns ninhos encontrados na Reserva Ducke, apresentando informações a respeito dos mesmos e uma chave de identificação dos gêneros. Os ninhos foram coletados através da busca direta, percorrendo os transectos da grade do Programa de Pesquisa em Biodiversidade; locais como margens de igarapés, bordas de acampamentos e construções na sede da reserva também foram explorados. Para todos os ninhos obteve-se o registro fotográfico e a localização exata por GPS. Foram registrados 39 ninhos de vespas sociais alocados em 17 espécies de Polistinae: Agelaia constructor, A. pallipes, Angiopolybia pallens, Apoica pallens, Metapolybia unilineata, Mischocyttarus lecointei, M. saturatus, Polybia bistriata, P. dimidiata, P. jurinei, P. liliacea, P. occidentalis, P. procellosa, P. rejecta, Protopolybia bituberculata, P. chartergoides e Synoeca virginea. Cinco ninhos desabitados de Mischocyttarus, Polybia e Polistes também foram coletados.

Social wasp species of Mischocyttarus (Phi) related to M. alfkenii (Ducke) and M. paraguayensis Zikán (Hymenoptera, Vespidae, Polistinae)

Social wasp species of Mischocyttarus (Phi) related to M. alfkenii (Ducke) and M. paraguayensis Zikán (Hymenoptera, Vespidae, Polistinae). A revision of the taxonomic status and an identification key are presented for species of the genus Mischocyttarus related to M. alfkenii (Ducke) and M. paraguayensis Zikán. Seven new species are proposed in the alfkenii and basimacula groups (M. achagua sp. nov.; M. arawak sp. nov.; M. awa sp. nov.; M. embera sp. nov.; M. muisca sp. nov.; M. uniformis sp. nov.; M. waunan sp. nov.), with five new synonymies [M. mamirauae Raw = M. alfkenii (Ducke); M. alfkenii excrucians Richards = M. flavicornis nigricornis Zikán = M. flavicornis Zikán; M. basimacula superpictus Richards = M. basimacula (Cameron)]. Specific status is also newly recognized for M. trinitatis Richards. Two new species are described in the paraguayensis and bahiae group (M. suzannae sp. nov.; M. tayacaja sp. nov.), while fifteen new synonymies are proposed (M. aracatubaensis Zikán = M. araujoi Zikán = M. costalimai Zikán = M. gilvus Zikán = M. infrastrigatoides Zikán = M. infrastrigatus Zikán = M. infrastrigatus Zikán = M. ornatulus Zikán = M. riograndensis Richards = M. rivulorum Richards = M. schrottkyi Zikán = M. scitulus Zikán = M. similaris Zikán = M. similatus Zikán = M. paraguayensis Zikán). These numbers change the picture of diversity in these species groups, as partly found in Richards's revision, published in 1978, reflecting higher diversity in northern Andean areas than in the Brazilian Atlantic region.

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest

Diversity and aspects of the ecology of social wasps (Vespidae, Polistinae) in Central Amazonian "terra firme" forest. The knowledge of social wasp richness and biology in the Amazonian region is considered insufficient. Although the Amazonas state is the largest in the region, until now only two brief surveys were conducted there. Considering that the systematic inventory of an area is the first step towards its conservation and wise use, this study presents faunal data on social wasp diversity in a 25 km² area of "terra firme" (upland forest) at the Ducke Reserve, Manaus, Amazonas, Brazil. Wasps were collected in the understory, following a protocol of three collectors walking along 60 trails 1,000 m in extension for 16 days between August and October 2010. Methods used were active search of individuals with entomological nets and nest collecting. Fifty-eight species of social wasps, allocated in 13 genera, were recorded; 67% of the collected species belong to Polybia, Agelaia and Mischocyttarus; other genera were represented by only four species or less. The most frequent species in active searches were Agelaia fulvofasciata (DeGeer, 1773), Agelaia testacea (Fabricius, 1804) and Angiopolybia pallens (Lepeletier, 1836). Twelve species were collected in nests. Prior to this study, 65 Polistinae species were deposited at the INPA Collection. Collecting in the study grid, an area not previously sampled for wasps, resulted in an increase of 25% species, and species richness was 86. According to the results, there is evidence that the diversity of social wasps at the Ducke Reserve is even higher, making it one of the richest areas in the Brazilian Amazonia.

Áreas de pesca de la flota artesanal de la zona norte del Perú (3,4° S A 6,5° S) 1996-1999

Analiza los resultados del procesamiento de la información relacionada a la potencialidad y dinámica extractiva de los pescadores artesanales, del área litoral comprendida entre los paralelos 3,4° y 6,5° de latitud sur (S) y los meridianos 80,0°-82,5°de longitud oeste (W) que conforman la zona de más alta diversidad y producción pesquera artesanal en el litoral peruano, frete a las costas de los departamentos de Tumbes y Piura.

Notes on social wasps of the group of Mischocyttarus(Omega) punctatus (Ducke), with description of six new species (Hymenoptera, Vespidae, Polistinae)

ABSTRACTA revision of the taxonomic status and an identification key for wasp species of the genus Mischocyttarus related to M. punctatus (Ducke, 1904) are presented here. Six new species are proposed (M. tayrona Silveira sp. nov.; M. anchicaya Silveira sp. nov.; M. caxiuana Silveira sp. nov.; M. verissimoi Silveira sp. nov.; M. rodriguesi Silveira sp. nov.; M. ryani Silveira sp. nov.), raising to nine the number of species in the M. punctatus group. The highest diversity of the group concentrates in northern South America, in Andean areas and Amazonia. New information concerning the very peculiar nests of these wasps is also given.

Condiciones biooceanográficas durante la evaluación del recurso merluza. Crucero BIC Jose Olaya Balandra 9901

La presencia frente a las costas de Sudamérica de una masa de agua subsuperficial, procedente del Pacífico occidental, ocasionó que el área de estudio presentara condiciones frías y una baja concentración de oxígeno en toda la columna de agua.

Note on predation of the brood of Mischocyttarus injucundus (de Saussure) by another social wasp in Caxiuanã, Pará, Brazil, with new records of species for the Ferreira Penna Research Station (Hymenoptera, Vespidae, Polistinae)

ABSTRACT Predation of the brood of Mischocyttarus injucundus by another polistine social wasp is reported from an Amazonian rainforest locality. This is the first report for the American tropics of naturally occurring predation by one social wasp on the brood of another. Three species are added to the list of the Ferreira Penna Research Station, raising known local richness to 81 species: Mischocyttarus filiformis (de Saussure, 1854), Mischocyttarus vaqueroi Zikán, 1949, and Parachartergus griseus (Fox, 1898).

Composición bioquímica y distribución de la materia orgánica sedimentaria y sus efectos sobre la estructura comunitaria de la meiofauna en la plataforma continental frente a Callao.

Se estudió la composición y distribución de la materia orgánica sedimentaria en términos de Carbohidratos, Lípidos y Proteínas, así como sus repercusiones sobre la estructura comunitaria de la meiofauna metazoaria (abundancia, biomasa y diversidad a nivel de grandes grupos), además, se estima su rol en el flujo de energía del sub-sistema bentónico mediante el cálculo de la producción secundaria y respiración frente a las costas de Perú Central, Callao (12ºS). Las muestras se recolectaron en el mes de Abril del año 2010, en un gradiente batimétrico en cinco estaciones: Estación E1 (48m) y E2 (93m) correspondiente a la plataforma interna, estación E3 (117m) correspondiente a la plataforma intermedia y la estación E4 (143m) y E5 (148m) correspondiente a la plataforma externa. En cada estación se determinaron parámetros fisicoquímicos como oxígeno disuelto, salinidad y temperatura. Asimismo se determinó el contenido de pigmentos fotosintéticos (clorofila- a y feopigmentos) en la columna de sedimento.

Escala de madurez gonadal del Lenguado Paralichthys adspersus (Steindachner, 1867)

Paralichthys adspersus "lenguado", especie endémica de las costas de Perú y Chile, es muy valorada comercialmente y los estudios demuestran la factibilidad de su cultivo. En tal sentido, la clasificación del desarrollo gonadal en escalas de madurez, viene a ser una fuente de información para conocer el ciclo reproductivo de esta especie y necesario para el manejo de los recursos en el medio natural así como en cautiverio. Los 162 individuos utilizados en la presente tesis, fueron adquiridos de capturas realizadas en la costa central del Perú. Los peces se evaluaron biométrica y biológicamente. Se analizaron y procesaron histológicamente 96 ovarios y 66 testículos. Se realizó la caracterización del desarrollo de los gametos y de las gónadas microscópica y macroscópicamente; además se evaluó la homogeneidad del ovario, la caracterización morfométrica de las poblaciones ovocitarias en cada estadio de madurez gonadal, la proporción sexual por grupos de longitudes totales, la talla de primera madurez gonadal y otros parámetros indicadores del desarrollo gonadal. Del grupo evaluado, las hembras representaron el 59,3% mientras que los machos el 40,7%.

Una Cort italianitzant a València. Notes sobre la recepció d’Ariosto a Espanya

Aquest estudi pretén mostrar com una cort perifèrica dins de la monarquia espanyola com la dels Centelles, comtes d’Oliva, tot imitant fil per randa la dels Este de Ferrara i la seva brillant presència en la Itàlia renaixentista mitjançant el mecenatge de Boiardo i d’Ariosto, va importar aquells esquemes i es va envoltar d’un grup d’escriptors que van constituir el nucli inicial de la recepció, difusió i continuació castellana de l’èpica d’Ariosto a la península Ibèrica. Gairebé es podria afirmar que la propagació en castellà de l’Orlando furioso a la península Ibèrica estava monopolitzada en gran part pel clan dels Centelles. Un cercle en el qual localitzem, segons tots els indicis, el traductor de Gli asolani de Bembo al castellà: Lluís Santàngel

Caracterización de la Zona de Mínimo de Oxígeno (ZMO) frente a la costa peruana entre 3°N y 14°S, 1999 - 2009

Se analizaron datos de oxígeno disuelto, frente a las costas del Perú, para comprender las variaciones de la ZMO, caracterizadas por: a) el espesor de esa zona, limitada por las isolíneas de oxígeno de 0,5 mL.L-1; y b) la profundidad de su límite superior en la franja marino costera. Se muestran los resultados de las evaluaciones en la columna de agua, en la bahía de Callao en el periodo 1999 – 2009, y además en enero - febrero 2009 en un estudio de la ZMO, durante el Crucero Meteor 77-4 0901-02: Interacción en el Océano Tropical, Biogeoquímica y Clima. En la zona costera del Callao (12°S) se acentúa la hipoxia; la ZMO se ve restringida por la plataforma y su límite superior más superficial se ubicó a los 2,5 m de profundidad. A partir de la información obtenida en enero–febrero 2009 (Crucero 0901-02) se analizó la variabilidad espacial de la ZMO, en donde se halló un espesor de ~637,8 m, en la sección Punta Falsa (6°S). Se analizó la dinámica de la ZMO y su límite superior, debido al gran interés que ha tomado, por el posible incremento de su espesor, en el contexto de cambio climático, con grandes repercusiones sobre los recursos pesqueros.