Tempo de busca e de manuseio de larvas de Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) alimentadas com Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae)

Searching and handling time of Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) larvae fed on Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae). The objective of this research was to determine the searching and handling times of three larval instars of C. externa fed on U. ambrosiae at densities of 30, 40 and 50 per vial, with the feeding of the larvae at the preceding instars being U. ambrosiae nymphs or Sitotroga cerealella (Olivier, 1819) eggs. The larvae were maintained at 25 ± 2 ºC, 70 ± 10% RH and a 14-h photophase. A completely randomized design in a 6 x 3 factorial scheme with 12 replicates was adopted. The shortest searching time was found for the 2nd and 3rd instar larvae of C. externa, and this parameter was variable depending on the feeding given to the larvae previously. The handling time was similar for the 1st, 2nd and 3rd instar larvae. The longest searching time was found at an aphid density of 30, as compared to densities of 40 and 50 prey, with which there were no significant differences. Prey density did not have any influence on handling time.

O gênero Xylocopa Latreille no Rio Grande do Sul, Brasil (Hymenoptera, Anthophoridae)

The genus Xylocopa Latreille in Rio Grande do Sul, Brazil (Hymenoptera, Anthophoridae). A survey of the genus Xylocopa Latreille, 1802 is given for Rio Grande do Sul, the southernmost State of Brazil. Data are based on several studies on the bee fauna of southern Brazil and on unpublished observations. A key is provided to the species (males and females) and information on distribution, nesting habits and relation to flowers. Rio Grande do Sul is strikingly rich in species of Xylocopa because of the diversity of habitats and its geographic position in the transition of tropical/subtropical to temperate climate. Nineteen species, classified into ten subgenera, have been recorded in Rio Grande do Sul. Here we maintain the subgenera Ioxylocopa, Megaxylocopa and Xylocospila, which were put into synonymy recently by Minckley (1998). The species are: Xylocopa (Dasyxylocopa) bimaculata Friese, 1903; Xylocopa (Ioxylocopa) chrysopoda Schrottky, 1902; Xylocopa (Megaxylocopa) frontalis (Olivier, 1789); Xylocopa (Nanoxylocopa) ciliata Burmeister, 1876; Xylocopa (Neoxylocopa) augusti Lepeletier, 1841; Xylocopa (N.) brasilianorum (Linnaeus, 1767); Xylocopa (N.) haematospila Moure, 1951; Xylocopa (N.) hirsutissima Maidl, 1912; Xylocopa (N.) nigrocincta Smith, 1854; Xylocopa (N.) ordinaria Smith, 1874; Xylocopa (N.) suspecta Moure & Camargo, 1988; Xylocopa (N.) tacanensis Moure, 1949; Xylocopa (Schonnherria) macrops Lepeletier, 1841; Xylocopa (S.) simillima Smith, 1854; Xylocopa (S.) splendidula Lepeletier, 1841; Xylocopa (S.) varians Smith, 1874; Xylocopa (Stenoxylocopa) artifex Smith, 1874; Xylocopa (Xylocopoda) elegans Hurd & Moure, 1963; Xylocopa (Xylocopsis) funesta Maidl, 1912; Xylocopa (Xylocospila) bambusae Schrottky, 1902. Xylocopa tacanensis is for the first time recorded in Brasil.

Catholic Loyalism, Service and Careerism: Lewes Lewkenor's Quest for Favour

This article discusses one of Lewkenor's more obscure works, The Resolved Gentleman (1594 - STC 15139), in the context of Elizabethan court politics in the 1590s, with a particular emphasis on the author's own experience of dissent, exile to Catholic Spain in the 1580s and return to England in the early 1590s. A translation of Hernando de Acuña's El Caballero Determinado, itself a reworking of Olivier de la Marche's Chevalier Délibéré (1483), the Resolved Gentleman bends the conventions of medieval chivalric allegory to articulate Lewkenor's own experience of alienation and dissent in the specific context of the factionalism of the 1590s. Beneath Lewkenor's seemingly self-effacing, 'humanist' translation it is in fact possible to discern a complex set of criticisms of Elizabeth's court. The knight's 'wandering' and 'errance' thus becomes a complex, multivalent figure that reverberates with a number of autobiographical meanings: the knight's exile becomes in Lewkenor's hands a figure of his own forced exile to Catholic Spain, and the account of the knight's quest functions as an oblique allusion to his own efforts to make his way back to Elizabeth's court. More importantly, however, these 'personal' meanings acquire a wider, political valence in the context of the allegory, and the narrative as a whole thus becomes a subtle, perceptive but scathing criticism of the Elizabethan court in the 1590's and the 'contraction' of royal favour that resulted in particular in the exclusion of capable, experienced but Catholic counsellors like Lewkenor himself. Articulating the frustration of this younger generation of alienated but fundamentally loyalist Catholics, Lewkenor paints a picture of a failed quest for favour, where the questing knight is finally forced to retire from the active life and withdraw to a rustic hermitage that is not only incompatible with his own ideal of the vita activa, but also dangerously smacks of unregenerate, and potentially seditious Catholicism.

Cerambycidae (Coleoptera) da Colômbia: IV. Cerambycinae com olhos grosseiramente granulados

New records for Colombian Cerambycidae - Achrysonini: Achryson immaculipenne Gounelle, 1909, A. lineolatum Erichson, 1847, A. quadrimaculatum (Fabricius, 1792); Ectenessini: Ectenessa lurida Martins, 1973; Cerambycini: Jupoata rufipennnis (Gory, 1831), Poeciloxestia carlyslei Fragoso, 1978, P. paraensis Lane, 1965; Elaphidionini: Ambonus electus (Gahan & Arrow, 1903), Paramallocera cribripennis (Bates, 1885), Periboeum pubescens (Olivier, 1790), Stizocera plicicollis (Germar, 1824), S. poeyi (Guérin-Méneville, 1838), Pantonyssus glabricollis Fuchs, 1961; Piezocerini: Haruspex lineolatus Bates, 1870; Eligmodermini: Eligmoderma spinicolle Aurivillius, 1923, E. ziczac Nonfried, 1895. New species described: Pantonyssus suturale sp. nov. (Santander); Anelaphus colombianus sp. nov. (Santander); A. sparsus sp. nov. (Magdalena).

Iterated local search

Iterated Local Search has many of the desirable features of a metaheuristic: it is simple, easy to implement, robust, and highly effective. The essential idea of Iterated Local Search lies in focusing the search not on the full space of solutions but on a smaller subspace defined by the solutions that are locally optimal for a given optimization engine. The success of Iterated Local Search lies in the biased sampling of this set of local optima. How effective this approach turns out to be depends mainly on the choice of the local search, the perturbations, and the acceptance criterion. So far, in spite of its conceptual simplicity, it has lead to a number of state-of-the-art results without the use of too much problem-specific knowledge. But with further work so that the different modules are well adapted to the problem at hand, Iterated Local Search can often become a competitive or even state of the artalgorithm. The purpose of this review is both to give a detailed description of this metaheuristic and to show where it stands in terms of performance.

Effectiveness of interventions targeting frequent users of emergency departments: a systematic review

Texte intégral: http://www.springerlink.com/content/3q68180337551r47/fulltext.pdf

Finite sample nonparametric tests for linear regressions

We introduce several exact nonparametric tests for finite sample multivariatelinear regressions, and compare their powers. This fills an important gap inthe literature where the only known nonparametric tests are either asymptotic,or assume one covariate only.

On the impact of leverage constraints on asset prices and trading volume

Researchers have used stylized facts on asset prices and trading volumein stock markets (in particular, the mean reversion of asset returnsand the correlations between trading volume, price changes and pricelevels) to support theories where agents are not rational expected utilitymaximizers. This paper shows that this empirical evidence is in factconsistent with a standard infite horizon perfect information expectedutility economy where some agents face leverage constraints similar tothose found in todays financial markets. In addition, and in sharpcontrast to the theories above, we explain some qualitative differencesthat are observed in the price-volume relation on stock and on futuresmarkets. We consider a continuous-time economy where agents maximize theintegral of their discounted utility from consumption under both budgetand leverage con-straints. Building on the work by Vila and Zariphopoulou(1997), we find a closed form solution, up to a negative constant, for theequilibrium prices and demands in the region of the state space where theconstraint is non-binding. We show that, at the equilibrium, stock holdingsvolatility as well as its ratio to stock price volatility are increasingfunctions of the stock price and interpret this finding in terms of theprice-volume relation.