Synchaeta jollyae (Shiel & Koste) (Rotifera, Synchaetidae): an overlooked species or a newcomer in Neotropical freshwaters?

Populations of Synchaeta jollyae (Shiel & Koste, 1993) (Rotifera), a species recently recorded for the first time in Brazil and South America, were analyzed in reservoirs in Southeast Brazil. Sampling was carried out monthly from August 2006 to July 2007 at Furnas Reservoir in the Rio Grande basin, state of Minas Gerais, and in four cascade reservoirs in the Tietê River basin (Barra Bonita, Bariri, Ibitinga and Nova Avanhandava) state of São Paulo, in June and September 2008 and in January and May 2009. Synchaeta jollyae occurred in most samples and periods. From the results obtained it is evident that S. jollyae occurs in water bodies of varied trophic status but reaches larger populations in eutrophic water bodies and during lower temperature periods. The greatest densities of S. jollyae were found in the eutrophic Bariri Reservoir, on the Tietê River, during the winter. Mann-Whitney test confirmed the significant difference between the population densities in periods of high and low temperatures, with populations reaching higher densities at lower temperatures. It is not yet possible to tell whether S. jollyae is a widely distributed species that has been overlooked in previous plankton studies in South America. Wherever these populations of S. jollyae might have originated, it appears to be a species well established and adapted to a wide range of conditions in the Neotropics.

Abundance of Conepatus chinga (Carnivora, Mephitidae) and other medium-sized mammals in grasslands of southern Brazil

Between January 2007 and December 2010, the abundance of medium-sized mammals was studied, with special focus on the Molina's hog-nosed skunk, Conepatus chinga (Molina, 1782), at four locations in southern Brazil. In this study, transect line methodology was used to obtain data for Distance Analyses. Transects were traveled by car at night, searching with spotlights along the edges of secondary roads in agricultural landscapes. Along 1,811 km, we obtained 620 observations of 20 mammal species. The most common species was the exotic European hare, Lepus europaeus (Pallas, 1778); the highest abundance estimated for South America was observed in one of the study areas, where its density was estimated as 32 individuals/km². Carnivores were the most commonly recorded mammals, represented by 10 species and comprising 51% of all observations. Molina's hog-nosed skunk occurred in all study areas, but occurred in sufficient numbers to obtain density estimates in only two of the areas. We estimated 1.4 to 3.8 individuals/km², in the first density estimate made by the transect method for a member of Conepatus in the Neotropics. These values are similar to those estimated for North American species of Mephitidae. In Brazil, C. chinga is apparently more abundant in the Pampa biome than in the grasslands of the Atlantic Forest. For two other carnivores, Lycalopex gymnocercus (Fisher, 1814) and Cerdocyon thous (Linnaeus, 1766), we estimated preliminary densities that were similar to those previously cited for different regions.

Temporal and spatial variation of rocky shores intertidal benthic communities in Southeast Brazil

The relationships between environmental factors and temporal and spatial variations of benthic communities of three rocky shores of the state of Espírito Santo, Southeast Brazil, were studied. Sampling was conducted every three months, from August 2006 to May 2007, using intersection points. Chthamalus bisinuatus (Pilsbry, 1916) (Crustacea) and Brachidontes spp. (Mollusca) were the most abundant taxa, occupying the upper level of the intertidal zone of the rocky shore. The species richness was higher at the lower levels. The invasive species Isognomon bicolor (C. B. Adams, 1845) (Mollusca) occurred at low densities in the studied areas. The clustering analysis dendrogram indicated a separation of communities based on exposed and sheltered areas. According to the variance analyses, the communities were significantly different among the studied areas and seasons. The extent of wave exposure and shore slope influenced the species variability. The Setibão site showed the highest diversity and richness, most likely due to greater wave exposure. The communities showed greater variation in the lower levels where environmental conditions were less severe, relative to the other levels.

Cubic spline population density functions and subcentre delimitation. The case of Barcelona

The presence of subcentres cannot be captured by an exponential function. Cubic spline functions seem more appropriate to depict the polycentricity pattern of modern urban systems. Using data from Barcelona Metropolitan Region, two possible population subcentre delimitation procedures are discussed. One, taking an estimated derivative equal to zero, the other, a density gradient equal to zero. It is argued that, in using a cubic spline function, a delimitation strategy based on derivatives is more appropriate than one based on gradients because the estimated density can be negative in sections with very low densities and few observations, leading to sudden changes in estimated gradients. It is also argued that using as a criteria for subcentre delimitation a second derivative with value zero allow us to capture a more restricted subcentre area than using as a criteria a first derivative zero. This methodology can also be used for intermediate ring delimitation.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease. 1 - Comparative xenodiagnosis with nine triatomine species of animals with acute infections by Trypanosoma cruzi

In search of a suitable vector species for xenodiagnosis of humans and animals with chronic Chagas' disease we first investigated the reactions of different vector species to acute infection with Trypanosoma cruzi. Vector species utilized in this study were: Triatoma infestans, Rhodnius prolixus and Triatoma dimidiata, all well adapted to human habitats; Triatoma rubrovaria and Rhodnius neglectus both considered totally wild species; Panstrongylus megistus, Triatoma sordida, Triatoma pseudomaculata and Triatoma brasiliensis, all essentially sylvatic but some with domiciliary tendencies and others restricted to peridomestic biotopes with incipient colonization of human houses after successful eradication of T. infestans. Results summarized in Table IV suggest the following order of infectivity among the 9 studied vector species: P. megistus with 97.8% of infected bugs, T. rubrovaria with 95% of positive bugs a close second followed by T. Pseudomaculata with 94.3% and R. neglectus with 93.8% of infected bugs, almost identical thirds. R. prolixus, T. infestans and T. dimidiata exhibited low infection rates of 53.1%, 51.6% and 38.2% respectively, coupled with sharp decreases occuring with aging of infection (Fig. 1). The situation was intermediate in T. brasiliensis and T. sordida infection rates being 76.9% and 80% respectively. Results also point to the existence of a close correlation between prevalence and intensity of infection in that, species with high infection rates ranging from 93.8% to 97.8% exhibited relatively large proportions of insects (27.3% - 33.5%) harbouring very dense populations of T. cruzi. In species with low infection rates ranging from 38.2% to 53.1% the proportion of bugs demonstrating comparable parasite densities was at most 6%. No differences attributable to blood-meal size or to greater susceptibility of indigenous vector species to parasites of their own geographical area, as suggested in earlier...

Observations on the dipteran fauna in a focus of dermal leishmaniasis in the State of Minas Gerais: II. The distribution of families in relation to their medical, veterinary and economic importance

Miniature light traps used to collect Phlebotominae in a focus of dermal leishmaniasis in the eastern part of the State of Minas Gerais, Brazil. Over a period of seven months, the other Diptera captured in 179 light trap samples were identified to family level. The traps were placed in eight localities which constituted three different biotopes: three woodland aresas, cultivated land, and a peridomestic site. A comparison is made between the totals of Dipeterans collected in each biotope, the total numbers of families collected in each biotope and the estimated indices of diversity. Dendograms representing the degrees of association between families of Diptera in different biotopes are presented. Some families of Diptera are uniformly distributed throughout the study area; a few families seem to have become adapted to areas where human activity has induced the greatest ecological changes. The impact between Dipterans and human well-being is discussed. The availabel evidence indicates that transmission of dermal leishmaniasis does not occur in areas where sand flies can be captured in greatest densities.

Minimal invasive surgery for coronoid fracture: technical note.

Operative treatment of coronoid fracture often requires a large dissection of soft tissue, resulting in elbow stiffness and functional limitation. The authors present a minimal invasive, safe technique, useful in the case of isolated coronoid fracture associated with elbow dislocation. This technique does not require soft tissue dissection and allows an early unlimited resumption of sports activities.

The change of behavior of two strains of Leishmania after cultivation in a defined medium

Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamsters, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.

Two's company, three's a crowd: experimental evaluation of the evolutionary maintenance of trioecy in Mercurialis annua (Euphorbiaceae).

Trioecy is an uncommon sexual system in which males, females, and hermaphrodites co-occur as three clearly different gender classes. The evolutionary stability of trioecy is unclear, but would depend on factors such as hermaphroditic sex allocation and rates of outcrossing vs. selfing. Here, trioecious populations of Mercurialis annua are described for the first time. We examined the frequencies of females, males and hermaphrodites across ten natural populations and evaluated the association between the frequency of females and plant densities. Previous studies have shown that selfing rates in this species are density-dependent and are reduced in the presence of males, which produce substantially more pollen than hermaphrodites. Accordingly, we examined the evolutionary stability of trioecy using an experiment in which we (a) indirectly manipulated selfing rates by altering plant densities and the frequency of males in a fully factorial manner across 20 experimental plots and (b) examined the effect of these manipulations on the frequency of the three sex phenotypes in the next generation of plants. In the parental generation, we measured the seed and pollen allocations of hermaphrodites and compared them with allocations by unisexual plants. In natural populations, females occurred at higher frequencies in denser patches, a finding consistent with our expectations. Under our experimental conditions, however, no combination of plant densities and male frequencies was associated with increased frequencies of females. Our results suggest that the factors that regulate female frequencies in trioecious populations of M. annua are independent of those regulating male frequencies (density), and that the stable co-existence of all three sex phenotypes within populations is unlikely.

Niche conservatism in non-native birds in Europe: niche unfilling rather than niche expansion

Aim Niche conservatism, or the extent to which niches are conserved across space and time, is of special concern for the study of non-native species as it underlies predictions of invasion risk. Based on the occurrence of 28 non-native birds in Europe, we assess to what extent Grinnellian realized niches are conserved during invasion, formulate hypotheses to explain the variation in observed niche changes and test how well species distribution models can predict non-native bird occurrence in Europe. Location Europe. Methods To quantify niche changes, a recent method that applies kernel smoothers to densities of species occurrence in a gridded environmental space was used. This corrects for differences in the availability of environments between study areas and allows discrimination between 'niche expansion' into environments new to the species and 'niche unfilling', whereby the species only partially fills its niche in the invaded range. Predictions of non-native bird distribution in Europe were generated using several distribution modelling techniques. Results Niche overlap between native and non-native bird populations is low, but niche changes are smaller for species having a higher propagule pressure and that were introduced longer ago. Non-native birds in Europe occupy a subset of the environments they inhabit in their native ranges. Niche expansion into novel environments is rare for most species, allowing species distribution models to accurately predict invasion risk. Main conclusions Because of the recent nature of most bird introductions, species occupy only part of the suitable environments available in the invaded range. This signals that apart from purely ecological factors, patterns of niche conservatism may also be contingent on population-specific historical factors. These results also suggest that many claims of niche differences may be due to a partial filling of the native niche in the invaded range and thus do not represent true niche changes.

Diagnostic et traitement de l'instabilité rotulienne [Diagnosis and treatment of patellar instability].

Patellar instability concerns mostly young and active patients. Because of the condition's multifactorial origin, knowledge about the risk factors of patella instability and the biomechanics of the femoropatellar joint are necessary to understand this disorder. Most of the patellar dislocations are spontaneously reduced. Only the patient's history, clinical examination and appropriate imaging lead to the correct diagnosis. If haemarthrosis is present, MRI is recommended to rule out concomitant injuries. A traumatic patellar dislocation without history of prior dislocation is treated conservatively. Surgical treatment is indicated in presence of intra-articular injury or for recurrent dislocations. The surgical procedure should correct the different factors of patella instability identified by preoperative analysis.

Point-occurrence self-similarity in crackling-noise systems and in other complex systems

It has been recently found that a number of systems displaying crackling noise also show a remarkable behavior regarding the temporal occurrence of successive events versus their size: a scaling law for the probability distributions of waiting times as a function of a minimum size is fulfilled, signaling the existence on those systems of self-similarity in time-size. This property is also present in some non-crackling systems. Here, the uncommon character of the scaling law is illustrated with simple marked renewal processes, built by definition with no correlations. Whereas processes with a finite mean waiting time do not fulfill a scaling law in general and tend towards a Poisson process in the limit of very high sizes, processes without a finite mean tend to another class of distributions, characterized by double power-law waiting-time densities. This is somehow reminiscent of the generalized central limit theorem. A model with short-range correlations is not able to escape from the attraction of those limit distributions. A discussion on open problems in the modeling of these properties is provided.

The Distribution Dynamics of Output Multipliers in Scotland 1998–2007

In an input-output context the impact of any particular industrial sector is commonly measured in terms of the output multiplier for that industry. Although such measures are routinely calculated and often used to guide regional industrial policy the behaviour of such measures over time is an area that has attracted little academic study. The output multipliers derived from any one table will have a distribution; for some industries the multiplier will be relatively high, for some it will be relatively low. The recentpublication of consistent input-output tables for the Scottish economy makes it possible to examine trends in this mdistribution over the ten year period 1998-2007. This is done by comparing the means and other summary measures of the distributions, the histograms and the cumulative densities. The results indicate a tendency for the multipliers to increase over the period. A Markov chain modelling approach suggests that this drift is a slow but long term phenomenon which appears not to tend to an equilibrium state. The prime reason for the increase in the output multipliers is traced to a decline in the relative importance of imported (both from the rest of the UK and the rest of the world) intermediate inputs used by Scottish industries. This suggests that models calibrated on the set of tables might have to be interpreted with caution.

Nylon wool column: a tool for obtaining monokine-rich eluates in the absence of serum

Diverse conditions for stimulating human mononuclear cells to release thymocyte costimulatory factors were tested for their contribution to the generation of supernatants high titers of these monokines. Activity titers increased with LPS concentration, reaching a plateau between 1 and 10 microng/ml. Indomethacin did not modify the monokine, but the assay for thymocyte costimulatory activity was substantially affected by inhibitory substances produced by the monocytes in the absence of indomethacin. The use of nylon wool columns to trap the cells was shown to be effective in raising cellular densities without decreasing activity titers. As result, the yield per cell could be maintained even in the absence of serum, an important step toward the goal of purifiying bioactive from crude broths.

Ghosts in contemporary African diasporic literature : re-visioning history, memory and identity

Starting from the observation that ghosts are strikingly recurrent and prominent figures in late-twentieth African diasporic literature, this dissertation proposes to account for this presence by exploring its various functions. It argues that, beyond the poetic function the ghost performs as metaphor, it also does cultural, theoretical and political work that is significant to the African diaspora in its dealings with issues of history, memory and identity. Toni Morrison's Beloved (1987) serves as a guide for introducing the many forms, qualities and significations of the ghost, which are then explored and analyzed in four chapters that look at Fred D'Aguiar's Feeding the Ghosts (1998), Gloria Naylor's Mama Day (1988), Paule Marshall's Praisesong for the Widow (1983) and a selection of novels, short stories and poetry by Michelle Cliff. Moving thematically through these texts, the discussion shifts from history through memory to identity as it examines how the ghost trope allows the writers to revisit sites of trauma; revise historical narratives that are constituted and perpetuated by exclusions and invisibilities; creatively and critically repossess a past marked by violence, dislocation and alienation and reclaim the diasporic culture it contributed to shaping; destabilize and deconstruct the hegemonic, normative categories and boundaries that delimit race or sexuality and envision other, less limited and limiting definitions of identity. These diverse and interrelated concerns are identified and theorized as participating in a project of "re-vision," a critical project that constitutes an epistemological as much as a political gesture. The author-based structure allows for a detailed analysis of the texts and highlights the distinctive shapes the ghost takes and the particular concerns it serves to address in each writer's literary and political project. However, using the ghost as a guide into these texts, taken collectively, also throws into relief new connections between them and sheds light on the complex ways in which the interplay of history, memory and identity positions them as products of and contributions to an African diasporic (literary) culture. If it insists on the cultural specificity of African diasporic ghosts, tracing its origins to African cultures and spiritualities, the argument also follows gothic studies' common view that ghosts in literary and cultural productions-like other related figures of the living dead-respond to particular conditions and anxieties. Considering the historical and political context in which the texts under study were produced, the dissertation makes connections between the ghosts in them and African diasporic people's disillusionment with the broken promises of the civil rights movement in the United States and of postcolonial independence in the Caribbean. It reads the texts' theoretical concerns and narrative qualities alongside the contestation of traditional historiography by black and postcolonial studies as well as the broader challenge to conventional notions such as truth, reality, meaning, power or identity by poststructuralism, postcolonialism or queer theory. Drawing on these various theoretical approaches and critical tools to elucidate the ghost's deconstructive power for African diasporic writers' concerns, this work ultimately offers a contribution to "speciality studies," which is currently emerging as a new field of scholarship in cultural theory.