Regulation and wage adjustment patterns : non parametric evidence from longitudinal data

This paper gives a first step toward a methodology to quantify the influences of regulation on short-run earnings dynamics. It also provides evidence on the patterns of wage adjustment adopted during the recent high inflationary experience in Brazil.The large variety of official wage indexation rules adopted in Brazil during the recent years combined with the availability of monthly surveys on labor markets makes the Brazilian case a good laboratory to test how regulation affects earnings dynamics. In particular, the combination of large sample sizes with the possibility of following the same worker through short periods of time allows to estimate the cross-sectional distribution of longitudinal statistics based on observed earnings (e.g., monthly and annual rates of change).The empirical strategy adopted here is to compare the distributions of longitudinal statistics extracted from actual earnings data with simulations generated from minimum adjustment requirements imposed by the Brazilian Wage Law. The analysis provides statistics on how binding were wage regulation schemes. The visual analysis of the distribution of wage adjustments proves useful to highlight stylized facts that may guide future empirical work.

Large scale laboratory cultures of Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) and Diaphanosoma biergei Korinek, 1981 (Cladocera)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Likelihood approximations and discrete models for tied survival data

Ties among event times are often recorded in survival studies. For example, in a two week laboratory study where event times are measured in days, ties are very likely to occur. The proportional hazards model might be used in this setting using an approximated partial likelihood function. This approximation works well when the number of ties is small. on the other hand, discrete regression models are suggested when the data are heavily tied. However, in many situations it is not clear which approach should be used in practice. In this work, empirical guidelines based on Monte Carlo simulations are provided. These recommendations are based on a measure of the amount of tied data present and the mean square error. An example illustrates the proposed criterion.

Stochastic dynamics in exotic and native blowflies: an analysis combining laboratory experiments and a two-patch metapopulation model

In this study we explored the stochastic population dynamics of three exotic blowfly species, Chrysomya albiceps, Chrysomya megacephala and Chrysomya putoria, and two native species, Cochliomyia macellaria and Lucilia eximia, by combining a density-dependent growth model with a two-patch metapopulation model. Stochastic fecundity, survival and migration were investigated by permitting random variations between predetermined demographic boundary values based on experimental data. Lucilia eximia and Chrysomya albiceps were the species most susceptible to the risk of local extinction. Cochliomyia macellaria, C. megacephala and C. putoria exhibited lower risks of extinction when compared to the other species. The simultaneous analysis of stochastic fecundity and survival revealed an increase in the extinction risk for all species. When stochastic fecundity, survival and migration were simulated together, the coupled populations were synchronized in the five species. These results are discussed, emphasizing biological invasion and interspecific interaction dynamics.

Laboratory Assessment of two Active Ingredients for Control of Coptotermes gestroi (Isoptera: Rhinotermitidae)

The subterranean termite Coptotermes gestroi Wasmann (Isoptera: Rhinotermitidae) is a pest of major economic importance in urban environments of southeastern Brazil. Compared to using pesticides for termite control, termite bait products target termites more specifically and also address environmental contamination issues. In this point of view, we performed two different bioassays ill order to evaluate the efficacy of boric acid and fipronil against different populations of C. gestroi. The results showed that concentration between 2000 and 3000 ppm of boric acid caused approximately 100 percent mortality ill termites. Concentrations between 0.01 and 0.0001 ppm of fipronil resulted in 100% termite mortality after 2 wk exposure. The data displayed a fast mortality of termites contaminated with fipronil, even with small concentrations, and therefore it is riot a Suitable product to be used ill baits against C gestroi. The present Study showed a delayed toxicity of boric acid against the subterranean termite C gestroi which suggests a need for further field tests.

Laboratory study on the bioremediation of diesel oil contaminated soil from a petrol station

O objetivo do presente estudo foi investigar possíveis métodos para aumentar a taxa de biodegradação aeróbia de hidrocarbonetos (tratamentos ex-situ). Neste trabalho, processos de biorremediação foram aplicados a um solo arenoso com alto nível de contaminação ocasionada por um vazamento de um tanque de armazenamento de óleo diesel subterrâneo em um posto de combustíveis. Experimentos em escala laboratorial (respirômetros de Bartha) foram utilizados para avaliar a biodegradação do óleo diesel. Estímulo da biodegradação foi realizado utilizando-se as técnicas de bioestímulo (adição de soluções de nitrogênio e fósforo ou surfactante Tween 80) e de bioaumento (consórcio bacteriano isolado de um sistema de landfarming). Para investigar as interações entre os fatores otimizadores, e encontrar a melhor combinação entre esses agentes, o estudo foi baseado em um delineamento experimental fatorial completo. A eficiência de biodegradação foi simultaneamente medida com dois métodos: respirométrico (produção de CO2 microbiano) e cromatografia gasosa. Testes de toxicidade aguda com Daphnia similis foram aplicados para examinar a eficiência dos processos em termos de geração de produtos menos tóxicos. Resultados mostraram que todas as estratégias de biorremediação aceleraram a biorremediação natural do solo contaminado e os melhores resultados foram obtidos quando os tratamentos tinham adição de nutrientes. Dados respirométricos indicaram uma máxima mineralização de hidrocarbonetos de 19,8%, obtida com a combinação dos três agentes, com uma remoção de hidrocarbonetos totais de petróleo (TPH) de 45,5% em 55 dias de tratamento. No final dos experimentos, duas espécies predominantes de bactéria foram isoladas e identificadas como Staphylococcus hominis e Kocuria palustris.

Zoeal morphology of Pachygrapsus transversus (Gibbes) (Decapoda, Grapsidae) reared in the laboratory

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Life cycle and host specificity of Amblyomma triste (Acari : Ixodidae) under laboratory conditions

We report biological data of two generations of Amblyomma triste in laboratory and compared the suitability of different host species. Infestations by larval and nymphal stages were performed on guinea pigs (Cavia porcellus), chickens (Gallus gallus), rats (Rattus norvegicus), rabbits (Oryctolagus cuniculus), wild mice (Calomys callosus), dogs (Canis familiaris) and capybaras (Hydrochaeris hydrochaeris). Infestations by adult ticks were performed on dogs, capybaras and rabbits. Tick developmental periods were observed in an incubator at 27degreesC and RH 90%. Guinea pigs were the most suitable hosts for larvae and nymphs, followed by chickens. The remaining host species were less suitable for immature ticks as fewer engorged ticks were recovered from them. Mean larval feeding periods varied from 3.8 to 4.7 d between different host species. Mean larval premolt periods ranged from 8.9 to 10.4 d. Nymphal mean feeding periods varied from 4.2 to 6.2 d for ticks fed on different host species. Premolt period of male nymphs (mean: 15.4 d) was significantly longer than that of female nymphs (14.7 d). Female nymphs were significantly heavier than male nymphs. The overall sex ratio of the adult ticks emerged from nymphs was 0.9:1 (M:F). Capybaras were the most suitable host for the tick adult stage as significantly more engorged females were recovered from them and these females were significantly heavier than those recovered from dogs or rabbits. The life cycle of A. triste in laboratory could be completed in an average period of 155 d. The potential role of guinea pigs, birds and capybaras, as hosts for A. triste in nature, is discussed.

Inversion polymorphism in laboratory strains and natural samples of Drosophila sturtevanti (saltans group, sturtevanti subgroup)

Drosophila sturtevanti (37 strains) showed eighteen inversions, five new and thirteen previously described. Among these strains, 24 were maintained for seven to 21 years under laboratory conditions, eight for less than 1 year, and six were natural samples analysed in the first generation after collection. Flies from natural samples were the most polymorphic in the number of different inversions as well as in the frequency of flies bearing heterozygous inversions. In all cases, chromosome III presented the greatest number of inversions, and most of them occurred in strains from the Amazonian region. The data obtained were consistent with the hypothesis that the inversion variability of a species is proportional to the variability of its habitats.

Clinical pathological data and analyses of mineral elements of cattle affected by epizootic botulism in the State of São Paulo

In order to study laboratorial aspects of beef cow mortality, a syndrome popularly known as ''doenca da vaca caida'', examens were made of blood, cerebrospinal fluid, serum, bone and liver samples from 32 naturally affected 4 to 9 year old cows, 27 belonging to the Nellore breed and 5 were crossbred Nellore, all originating from farms located in municipalities near Botucatu, State of São Paulo. Laboratory determinations were analysed by descriptive statistics and included hematological values, total plasma protein, plasma fibrinogen, cerebrospinal fluid analysis, and concentration measurements of serum calcium, phosphorus, magnesium, sodium, potassium, chloride, total protein, albumin, globulin, alkaline phosphatase, aspartate aminotransferase, gama-glutamyltransferase and creatine kinase activities, included bone ash percentage and concentrations of calcium, phosphorus and magnesium, and also hepatic levels of copper, zinc, iron, manganese and cobalt. In addition, mouse bioassays and complement micro-fixation tests were performed to detect botulinum toxins in liver samples. The results indicated leukocytosis (13,3+/-3,9 x10(3)/mm(3)) with neutrophilia (8,9+/-3,2 x10(3)/mm(3)), hypocalcemia (7,8+/-1,7mg/dl), hypophosphatemia (3,6+/-1,6mg/dl), hypoalbuminemia (2,9+/-0,9g/dl), increased creatine kinase activity (691,0+/-829,7 UI/1), and reduced ash percentage (60,3+/-1,9%) and low phosphorus (17,2+/-0,4%) in bone. The other values were ail within normal limits. The diagnosis of botulism, involving type C and D toxins, was confirmed as the cause of the mortality in the region of study, what is strongly consistent with the other laboratorial findings.

Growth and juvenile development of Uca maracoani Latreille 1802-1803 in laboratory conditions (Crustacea, Decapoda, Brachyura, Ocypodidae).

The life cycle of decapod crustaceans can be classified into three distinct morphological phases: larval, juvenile and adult. Despite its recognized importance, studies of the juvenile phase have been neglected. The present Study aimed to analyze the growth of juveniles from a single population of Uca maracoani under laboratory conditions, and also to describe the morphological differentiation of pleopods in each sex. Megalopae and juvenile crabs or U. maracoani obtained on a Mud beach at Jabaquara, Paraty, on the southern coast of the state of Rio de Janeiro (Brazil), were reared in the laboratory. The specimens were checked daily for molts and deaths. The carapace widths (CW) of intact exuviae and dead individuals were measured under a stereoscopic microscope provided with a micrometer rule. These data allowed the definition of a growth equation as well as the stages related to the beginning of pleopod development, which begins when females reach 3.0 mill CW (6th juvenile developmental stage), similar to the sizes reported for other species of the genus. In males, however, pleopods appear when the crabs reach 3.5 mm CW, equivalent to the 7th developmental stage. This difference may be related to differential growth between sexes. It also may be a consequence of laboratory rearing, or may represent an actual feature of the species.

Oviposition and survival in females of Procornitermes araujoi under laboratory conditions (Isoptera, Termitidae, Nasutitermitinae)

After an enormous swarming of Procornitermes araujoi when a great number of females were collected, we investigated the occurrence of parthenogenesis beyond oviposition and survival of these females under laboratory conditions. The groups of virgin females were faster in their first oviposition than females of male-female pairs, nevertheless their eggs never hatch. The survival data showed higher longevity in the group of three females when compared with groups of two and four females.

Growth patterns of incipient colonies of Coptotermes havilandi (Isoptera, Rhinotermitidae) initiated in the laboratory from swarming alates

Fifty two colonies of Coptotermes havilandi were set up under laboratory conditions using alates collected from an urban area during a period of swarming. The first artificial nest used for each royal couple was a 6cm diameter Petri dish (22ml) filled with a moistened matrix of decayed pine sawdust. After 6 months, these colonies were transferred to 250ml plastic containers with the same culturing matrix. After 24 months a census of all colonies was performed. Each young colony had a live royal pair and the population size of all colonies indicated a nonlinear development. The total population (workers + soldiers + immatures + reproductives) of these incipient colonies ranged from 64 to 1, 164, with a mean of 345 individuals. The number of workers ranged from 53 to 830 individuals, and the number of soldiers ranged from 6 to 83. The present data showed a higher population of incipient colonies than our previous record for the species. We also compared the development of 12 transferred colonies to that of 12 untransferred incipient colonies. The results showed a higher population in transferred colonies, but in both incipient colonies (transferred and untransferred) there was a wide variation in total population. The correlation between queen weight and population size was positive in all 24 colonies.

Population dynamics of Ectatomma brunneum (Hymenoptera, Formicidae) under laboratory conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biological aspects of Amblyomma brasiliense (Acari: Ixodidae) under laboratory conditions

Although Amblyomma brasiliense Aragão 1908 has been reported as one of the most aggressive ticks to humans in Brazil, information about the biology of this tick species is virtually inexistent. This work reports data on the life cycle of A. brasiliense fed on rabbits and pigs and maintained in an incubator at 20°C, 90% RH and 12 h of light for off-host development. Tick yield of adult females fed on pigs and rabbits was 81.2% and 58.3%, respectively. Females fed on pigs had mean engorgement weight of 862.3 mg and egg mass of 208 mg, while females fed on rabbits had mean engorgement weight of 606.1 mg and egg mass of 160 mg; these values did not differ statistically between host species. Feeding period of female ticks fed on pigs (10 days) was significantly shorter than that on rabbits (17 days). Mean preoviposition period was slightly longer (35.9 days) for ticks fed on pigs than on rabbits (30 days). The minimum incubation period of eggs of ticks from both host species was similar and over 100 days. Egg production efficiency was low for females fed on both hosts (less than 30% and 20% for ticks from pigs and rabbits, respectively). More than 55% of larvae and 79% of nymphs fed on rabbits, set free inside the feeding chambers, engorged successfully. These ticks attained an engorgement weight of 1.3 and 18.2 mg, respectively, and fed for approximately 5 days. The minimum pre-molt period was 30 days for engorged larvae and over 44 days for nymphs. Molting success was low, less than 50% in the case of larvae and less than 20% for nymphs. Further studies are required to better determine the off-host requirements of this tick species. © 2008 Springer Science+Business Media B.V.