Ocorrência de sirfídeos afidófagos (Diptera, Syrphidae) em Lavras, MG

A ocorrência de sirfídeos afidófagos nas culturas de citros, couve, pepino, trigo e batata foi registrada. As amostragens foram realizadas, quinzenalmente, de agosto a dezembro de 2002. Constatou-se as espécies:Ocyptamus gastrostactus (Wiedemann, 1830), Allograpta exotica (Wiedemann, 1830), Pseudodorus clavatus (Fabricius, 1794) e Ocyptamus anthiphates (Walker, 1849). P. clavatus ocorreu em todas as culturas amostradas, com a maior densidade populacional (72%), seguido de O. gastrostactus (16%), A. exotica (11%) e O. anthiphates (1%). A ocorrência dos sirfídeos esteve correlacionada com os fatores climáticos e a presença dos afídeos.

Testing I(1) against I(d) alternatives in the presence of deteministic components

This paper discusses the role of deterministic components in the DGP and in the auxiliaryregression model which underlies the implementation of the Fractional Dickey-Fuller (FDF) test for I(1) against I(d) processes with d [0, 1). This is an important test in many economic applications because I(d) processess with d < 1 are mean-reverting although, when 0.5 = d < 1, like I(1) processes, they are nonstationary. We show how simple is the implementation of the FDF in these situations, and argue that it has better properties than LM tests. A simple testing strategy entailing only asymptotically normally distributedtests is also proposed. Finally, an empirical application is provided where the FDF test allowing for deterministic components is used to test for long-memory in the per capita GDP of several OECD countries, an issue that has important consequences to discriminate between growth theories, and on which there is some controversy.

Revisão do gênero Antiteuchus Dallas (Heteroptera, Pentatomidae, Discocephalinae)

Revisão do gênero Antiteuchus Dallas (Heteroptera, Pentatomidae, Discocephalinae). O gênero Antiteuchus Dallas, 1851 com 46 espécies descritas é revisado; as espécies são redescritas com base na morfologia externa da genitália do macho e em algumas características da morfologia geral do corpo. Neodine Kirkaldy, 1909 é considerado sinônimo junior de Antiteuchus. As espécies foram subdivididas em seis grupos aqui propostos: A. amplus, A. supinatus, A. peruensis, A. tesselatus, A. marmoratus e A. mixtus. Oito novas espécies são descritas: A. amapensis sp. nov., A. beckerae sp. nov., A. doesburgi sp. nov., A. exiguus sp. nov., A. ledeburi sp. nov., A. marini sp. nov., A. melanicus sp. nov. and A. similis sp. nov. Nove espécies e uma subespécie são sinonimizadas. Antiteuchus varians Ruckes, 1964 é considerada sinônimo júnior de A. pallescens Stål, 1868; A. englemani Rolston, 1993 de A. amplus (Walker, 1867); A. tripterus limbativentris Ruckes, 1964 e A. minor Engleman, 1983 de A. tripterus (Fabricius, 1787); A. fuscus (Ruckes, 1959), A. piceus (Palisot de Beauvois, 1805), A. subgibbus Engleman, 1983, A. subimpunctatus Ruckes, 1964, A. unicolor (Westwood, 1837) e A. variolosus (Westwood, 1837) de A. mixtus (Fabricius, 1787). Antiteuchus tatei (Ruckes, 1958) é considerada species inquirenda. Empicoris marmoreus Spinola, 1837 é colocada em incertae sedis e tratada como species inquirenda. O macho de A. pictus, até agora desconhecido, é descrito. Chaves de identificação para os machos das espécies de Antiteuchus e para os grupos de espécies são apresentadas.

Organisational values as "attractors of chaos": An emerging cultural change to manage organisational complexity

Business organisations are excellent representations of what in physics and mathematics are designated "chaotic" systems. Because a culture of innovation will be vital for organisational survival in the 21st century, the present paper proposes that viewing organisations in terms of "complexity theory" may assist leaders in fine-tuning managerial philosophies that provide orderly management emphasizing stability within a culture of organised chaos, for it is on the "boundary of chaos" that the greatest creativity occurs. It is argued that 21st century companies, as chaotic social systems, will no longer be effectively managed by rigid objectives (MBO) nor by instructions (MBI). Their capacity for self-organisation will be derived essentially from how their members accept a shared set of values or principles for action (MBV). Complexity theory deals with systems that show complex structures in time or space, often hiding simple deterministic rules. This theory holds that once these rules are found, it is possible to make effective predictions and even to control the apparent complexity. The state of chaos that self-organises, thanks to the appearance of the "strange attractor", is the ideal basis for creativity and innovation in the company. In this self-organised state of chaos, members are not confined to narrow roles, and gradually develop their capacity for differentiation and relationships, growing continuously toward their maximum potential contribution to the efficiency of the organisation. In this way, values act as organisers or "attractors" of disorder, which in the theory of chaos are equations represented by unusually regular geometric configurations that predict the long-term behaviour of complex systems. In business organisations (as in all kinds of social systems) the starting principles end up as the final principles in the long term. An attractor is a model representation of the behavioral results of a system. The attractor is not a force of attraction or a goal-oriented presence in the system; it simply depicts where the system is headed based on its rules of motion. Thus, in a culture that cultivates or shares values of autonomy, responsibility, independence, innovation, creativity, and proaction, the risk of short-term chaos is mitigated by an overall long-term sense of direction. A more suitable approach to manage the internal and external complexities that organisations are currently confronting is to alter their dominant culture under the principles of MBV.

Further evidence on the statistical properties of real GNP

The well-known lack of power of unit root tests has often been attributed to the shortlength of macroeconomic variables and also to DGP s that depart from the I(1)-I(0)alternatives. This paper shows that by using long spans of annual real GNP and GNPper capita (133 years) high power can be achieved, leading to the rejection of both theunit root and the trend-stationary hypothesis. This suggests that possibly neither modelprovides a good characterization of these data. Next, more flexible representations areconsidered, namely, processes containing structural breaks (SB) and fractional ordersof integration (FI). Economic justification for the presence of these features in GNP isprovided. It is shown that the latter models (FI and SB) are in general preferred to theARIMA (I(1) or I(0)) ones. As a novelty in this literature, new techniques are appliedto discriminate between FI and SB models. It turns out that the FI specification ispreferred, implying that GNP and GNP per capita are non-stationary, highly persistentbut mean-reverting series. Finally, it is shown that the results are robust when breaksin the deterministic component are allowed for in the FI model. Some macroeconomicimplications of these findings are also discussed.

O gênero Chinavia Orian (Hemiptera, Pentatomidae, Pentatominae) no Brasil, com chave pictórica para os adultos

Chinavia Orian é um dos gêneros mais diversos da subfamília Pentatominae, distribuído nas regiões Afrotropical, Neártica e Neotropical. Para o Brasil, são conhecidas 32 espécies, dentre as quais 18 são endêmicas. Do total de espécies com registro para o Brasil, 18 têm algum tipo de registro com plantas-hospedeiras, a maioria delas cultivadas; apenas seis espécies têm os imaturos conhecidos ou algum aspecto de sua biologia estudado. Neste trabalho, é fornecida uma chave pictórica para os adultos das espécies registradas no Brasil, acompanhada da diagnose comparada de cada uma delas, além das informações disponíveis na literatura sobre imaturos e biologia das espécies. Duas novas sinonímias são propostas: Acrosternum (Chinavia) bellum Rolston, 1983 é sinônimo júnior de Chinavia nigrodorsata (Breddin, 1903) e Acrosternum (Chinavia) panizzii Frey-da-Silva & Grazia, 2001 é sinônimo júnior de Chinavia obstinata (Stål, 1860). Chinavia nigritarsis (Stål, 1872), anteriormente considerada sinônimo júnior de Chinavia gravis (Walker, 1867), é revalidada. Fotografias coloridas do aspecto dorsal de todas as espécies são fornecidas, a maioria delas confeccionadas a partir do material-tipo estudado. Novos registros de distribuição geográfica e de associação com plantas-hospedeiras no Brasil são apresentados.

Swiss consensus statement: Recommendations for optimising re-treatment with MabThera (rituximab) in rheumatoid arthritis.

Rituximab is an effective treatment of rheumatoid arthritis (RA), which has been approved for the treatment of moderate to severe disease in patients with an inadequate response to anti-TNF therapies. Rituximab differs from other available biological agents for RA by way of its unique mode of action and unrivalled long dosing interval. The efficacy of rituximab subsides progressively over time and re-therapy is generally required to maintain long term disease control. The timing of re-treatment is currently not well established and varies widely in clinical practice. The present document is a concise recommendation regarding re-treatment with rituximab, based on validated outcomes such as the DAS28 and the EULAR response criteria. The recommendation was established through consensus between practitioners familiar with rituximab therapy in RA. Optimisation of the rituximab re-treatment schedule may improve patient outcomes and balance risks and benefits for the individual patient.

Cumulative dominance and heuristic performance in binary multi-attribute choice

Several studies have reported high performance of simple decision heuristics multi-attribute decision making. In this paper, we focus on situations where attributes are binary and analyze the performance of Deterministic-Elimination-By-Aspects (DEBA) and similar decision heuristics. We consider non-increasing weights and two probabilistic models for the attribute values: one where attribute values are independent Bernoulli randomvariables; the other one where they are binary random variables with inter-attribute positive correlations. Using these models, we show that good performance of DEBA is explained by the presence of cumulative as opposed to simple dominance. We therefore introduce the concepts of cumulative dominance compliance and fully cumulative dominance compliance and show that DEBA satisfies those properties. We derive a lower bound with which cumulative dominance compliant heuristics will choose a best alternative and show that, even with many attributes, this is not small. We also derive an upper bound for the expected loss of fully cumulative compliance heuristics and show that this is moderateeven when the number of attributes is large. Both bounds are independent of the values ofthe weights.

Revisão taxonômica de Kanaima Distant (Hemiptera, Cercopidae, Ischnorhininae)

Kanaima Distant, 1909 é revisado, sendo suas espécies descritas e redefinidas. Este trabalho ressalta os caracteres taxonomicamente importantes das espécies de Kanaima, como os da morfologia externa e da genitália. Quatro espécies são reconhecidas como válidas: K. katzensteinii (Berg, 1879), K. fluvialis (Lallemand, 1924), K. fusca (Lallemand, 1927) comb. nov., e K. nigra sp. nov. (Brasil, RS). Os nomes Monecphora fluvialis var. lateralis Lallemand, 1924 e Monecphora fluvialis var. bipunctata Lallemand, 1924 são sinonimizados sob Kanaima fluvialis. Quatro espécies incluídas em Kanaima são transferidas para Mahanarva: M. (Ipiranga) vittata (Walker, 1851) comb. nov., M. (Ipiranga) fortunata (Lallemand, 1924) comb. nov., M. (Mahanarva) radiata (Walker, 1851) comb. nov. e M. (Mahanarva) dubia (Stancik & Cavichioli, 2003) comb. nov. Pachypterinella Lallemand, 1927 sin. nov.

Local volatility changes in the black-scholes model

In this paper we address a problem arising in risk management; namely the study of price variations of different contingent claims in the Black-Scholes model due to anticipating future events. The method we propose to use is an extension of the classical Vega index, i.e. the price derivative with respect to the constant volatility, in thesense that we perturb the volatility in different directions. Thisdirectional derivative, which we denote the local Vega index, will serve as the main object in the paper and one of the purposes is to relate it to the classical Vega index. We show that for all contingent claims studied in this paper the local Vega index can be expressed as a weighted average of the perturbation in volatility. In the particular case where the interest rate and the volatility are constant and the perturbation is deterministic, the local Vega index is an average of this perturbation multiplied by the classical Vega index. We also study the well-known goal problem of maximizing the probability of a perfect hedge and show that the speed of convergence is in fact dependent of the local Vega index.

New species and records of Chimarra Stephens (Trichoptera, Philopotamidae) from Central Amazonia, Brazil

Chimarra (Curgia) paucispina sp. nov., of the aurivittata group Flint, 1998 is described and illustrated from specimens collected in Amazonas State. The key to species of Chimarra (Curgia) Walker, 1860 presented by Flint was modified to include the new species. Chimarra (Chimarrita) chela Blahnik, 1997 and Chimarra (Curgia) jugescens Flint, 1998 are for first time reported for the Amazonas State. This is the first record of C. chela in Brazil.

Long-run selection and the work ethic

That individuals contribute in social dilemma interactions even when contributing is costly is a well-established observation in the experimental literature. Since a contributor is always strictly worse off than a non-contributor the question is raised if an intrinsic motivation to contribute can survive in an evolutionary setting. Using recent results on deterministic approximation of stochastic evolutionary dynamics we give conditions for equilibria with a positive number of contributors to be selected in the long run.

Frugivoria de larvas de Neosilba McAlpine (Diptera, Lonchaeidae) sobre Psittacanthus plagiophyllus Eichler (Santalales, Loranthaceae) no sudoeste de Mato Grosso do Sul, Brasil

Loranthaceae são plantas hemiparasitas com distribuição geográfica mundial e representadas no Brasil por seis gêneros. Os mais importantes são Phthirusa, Psittacanthus e Struthanthus, os quais parasitam uma grande diversidade de plantas hospedeiras. Este trabalho avaliou a occurrência e a flutuação sazonal de moscas infestando os frutos de Psittacanthus plagiophyllus nos municípios de Anastácio, Aquidauana e Miranda, Mato Grosso do Sul, Brasil, onde ervas-de-passarinho são disseminadas. As coletas foram realizadas de junho de 1998 a julho de 2000 para obtenção de frutos maduros de P. plagiophyllus, seus insetos associados e catalogação dos seus hospedeiros. Os insetos foram criados para identificação, sendo obtidos 1.522 adultos de Neosilba spp., destes, 612 machos foram identificados a nível específico: Neosilba bifida Strikis & Prado (6 indivíduos), N. certa (Walker) (26 indivíduos), N. pendula (Bezzi) (16 indivíduos), N. zadolicha McAlpine & Steyskal (4 indivíduos) e duas diferentes espécies: morfotipo MSP1 (478 indivíduos) e morfotipo 4 (82 indivíduos). O período de mais alta infestação por Neosilba spp. ocorreu durante agosto de 1998 e de 1999 e, a espécie morfotipo MSP1 foi significativamente mais abundante que todas as outras. A morfotipo 4 foi a segunda mais abundante, diferindo significativamente de Neosilba zadolicha. Neosilba foi o único gênero de moscas frugívoras (Tephritoidea) infestante dos frutos de P. plagiophyllus e comportou-se como um invasor primário neste hospedeiro.

Adaptive model selection using empirical complexities

Given $n$ independent replicates of a jointly distributed pair $(X,Y)\in {\cal R}^d \times {\cal R}$, we wish to select from a fixed sequence of model classes ${\cal F}_1, {\cal F}_2, \ldots$ a deterministic prediction rule $f: {\cal R}^d \to {\cal R}$ whose risk is small. We investigate the possibility of empirically assessingthe {\em complexity} of each model class, that is, the actual difficulty of the estimation problem within each class. The estimated complexities are in turn used to define an adaptive model selection procedure, which is based on complexity penalized empirical risk.The available data are divided into two parts. The first is used to form an empirical cover of each model class, and the second is used to select a candidate rule from each cover based on empirical risk. The covering radii are determined empirically to optimize a tight upper bound on the estimation error. An estimate is chosen from the list of candidates in order to minimize the sum of class complexity and empirical risk. A distinguishing feature of the approach is that the complexity of each model class is assessed empirically, based on the size of its empirical cover.Finite sample performance bounds are established for the estimates, and these bounds are applied to several non-parametric estimation problems. The estimates are shown to achieve a favorable tradeoff between approximation and estimation error, and to perform as well as if the distribution-dependent complexities of the model classes were known beforehand. In addition, it is shown that the estimate can be consistent,and even possess near optimal rates of convergence, when each model class has an infinite VC or pseudo dimension.For regression estimation with squared loss we modify our estimate to achieve a faster rate of convergence.

Revisão de Ceyxia Girault, stat. rev. (Hymenoptera, Chalcididae, Brachymeriini)

O gênero Ceyxia Girault é revalidado e 27 espécies são combinadas a ele. Sete espécies previamente descritas são diagnosticadas (ou redescritas) e discutidas, e 20 espécies novas são descritas. Ceyxia flaviscapus Girault, 1911 and C. ventrispinosa Girault, 1911 stat. rev. foram originalmente combinadas com Ceyxia e as seguintes são combinações novas: C. belfragei (Crawford, 1910) comb. nov., stat. rev.; C. concitator (Walker, 1862) comb. nov.; C. decreta (Walker, 1862) comb. nov.; C. dorsalis (Walker, 1861) comb. nov.; e C. villosa (Olivier, 1790) comb. nov. Ceyxia paraguayensis Girault, 1911 é consyiderada sinônimo júnior de Ceyxia flaviscapus Girault, 1911. As novas espécies são: C. acutigaster sp. nov.; C. amazonica sp. nov.; C. atuberculata sp. nov.; C. bellissima sp. nov.; C. dentiformis sp. nov.; C. diminuta sp. nov.; C. fusidentata sp. nov.; C. gibbosa sp. nov.; C. laminata sp. nov.; C. laticlipeata sp. nov.; C. latilabra sp. nov.; C. longiarticulata sp. nov.; C. longiscutellaris sp. nov.; C. longispina sp. nov.; C. nigropetiolata sp. nov.; C. paraensis sp. nov.; C. parvidentata sp. nov.; C. perparva sp. nov.; C. pseudovillosa sp. nov.; e C. tibiodilatata sp. nov. Dados sobre a associação com hospedeiros são apresentados para algumas espécies do gênero. Uma chave para as espécies do gênero é incluída.