Averaging for retarded functional differential equations

We consider retarded functional differential equations in the setting of Kurzweil-Henstock integrable functions and we state an averaging result for these equations. Our result generalizes previous ones. (C) 2011 Elsevier Inc. All rights reserved.

Breeding of the Rufous-thighed Hawk (Accipiter erythronemius) in Argentina and Brazil

The Rufous-thighed, Hawk (Accipiter erythronemius) is a poorly-known, small raptor that dwells in forests and wooded savannas in south and eastern Brazil, Taraguay, eastern Bolivia, north and central Argentina, and Uruguay. We studied breeding biology and food habits of the Rufous-thighed Hawk from 1994 to 2007. We documented 14 breeding attempts recorded at nine nest sites in eight localities in Argentina and Brazil. Rufous-thighed Hawks were year-round residents at the study areas. The breeding season was c. 38 weeks long (June through March). Territorial behavior and courtship spanned for 22 weeks starting in mid June. Nest-building started in August. Nestlings were observed throughout December and into early January while fledglings were observed from late December through late March. Most nest sites were conifer plantations averaging 32.2 (SD = 10) years old, 12.6 ha (SD = 11.3) in size with trees averaging d 37.5 cm (SD = 13.5) of diameter at breast height. Nests were placed 20.2 m high (SD = 5.7), near the trunks of non-emergent conifers (Pinus sp. or Araucaria angustifolia). Nests were made of sticks, greater diameter averaging 48.8 cm (SD = 11.4), while nest depth averaged 23.3 cm (SD = 14). Prey items were birds (n = 49) ranging in size from c. 10 g [House Wren (Troglodytes, aedon)] to c. 140 g [White-tipped Dove (Leptotila verreauxi)]. Young started to chase birds at the age of 42-45 days in mid January. Adult males were primarily food providers but also aided in nest defense against other raptors. Females incubated, brooded, and fed young, and took leading roles in defense against humans. Rufous-thighed Hawks had unlined nests placed high in trees, and breeding season was markedly protracted.

Untangling associations between chironomid taxa in Neotropical streams using local and landscape filters

1. Analyses of species association have major implications for selecting indicators for freshwater biomonitoring and conservation, because they allow for the elimination of redundant information and focus on taxa that can be easily handled and identified. These analyses are particularly relevant in the debate about using speciose groups (such as the Chironomidae) as indicators in the tropics, because they require difficult and time-consuming analysis, and their responses to environmental gradients, including anthropogenic stressors, are poorly known. 2. Our objective was to show whether chironomid assemblages in Neotropical streams include clear associations of taxa and, if so, how well these associations could be explained by a set of models containing information from different spatial scales. For this, we formulated a priori models that allowed for the influence of local, landscape and spatial factors on chironomid taxon associations (CTA). These models represented biological hypotheses capable of explaining associations between chironomid taxa. For instance, CTA could be best explained by local variables (e.g. pH, conductivity and water temperature) or by processes acting at wider landscape scales (e.g. percentage of forest cover). 3. Biological data were taken from 61 streams in Southeastern Brazil, 47 of which were in well-preserved regions, and 14 of which drained areas severely affected by anthropogenic activities. We adopted a model selection procedure using Akaike`s information criterion to determine the most parsimonious models for explaining CTA. 4. Applying Kendall`s coefficient of concordance, seven genera (Tanytarsus/Caladomyia, Ablabesmyia, Parametriocnemus, Pentaneura, Nanocladius, Polypedilum and Rheotanytarsus) were identified as associated taxa. The best-supported model explained 42.6% of the total variance in the abundance of associated taxa. This model combined local and landscape environmental filters and spatial variables (which were derived from eigenfunction analysis). However, the model with local filters and spatial variables also had a good chance of being selected as the best model. 5. Standardised partial regression coefficients of local and landscape filters, including spatial variables, derived from model averaging allowed an estimation of which variables were best correlated with the abundance of associated taxa. In general, the abundance of the associated genera tended to be lower in streams characterised by a high percentage of forest cover (landscape scale), lower proportion of muddy substrata and high values of pH and conductivity (local scale). 6. Overall, our main result adds to the increasing number of studies that have indicated the importance of local and landscape variables, as well as the spatial relationships among sampling sites, for explaining aquatic insect community patterns in streams. Furthermore, our findings open new possibilities for the elimination of redundant data in the assessment of anthropogenic impacts on tropical streams.

Reaction microtextures of monazite: Correlation between chemical and age domains in the Nazare Paulista migmatite, SE Brazil

Back-scattered imaging, X-ray element mapping and electron microprobe analyzer (EMPA) chemical dating reveal complex compositional and age zoning in monazite crystals from different layers and textural positions in a garnet-bearing migmatite in SE Brazil. Y-rich (variable Y(2)O(3), averaging 2.5 wt.%) relict cores are preserved in mesosome and melanosome monazite, and correspond to 793 +/- 6 Ma inherited crystals possibly generated in a previous metamorphic event. These cores are overgrown and widely replaced by two generations of monazite, which are present in all migmatite layers. The first, also Y-rich (average 2.5 wt.% Y(2)O(3)), was produced at similar to 635 Ma during prograde metamorphism under subsolidus conditions, while the second has an Y-poor (<1.5 wt.% Y(2)O(3)), low Th/U signature, and precipitated from low Y and HREE anatectic melts produced by reactions in which garnet was inert. Quartz-rich trondhjemitic leucosome represents lower temperature melt (bearing some subsolidus quartz and garnet with included monazite) formed at temperatures below muscovite breakdown; its Y-poor monazite indicates an age of 617 +/- 6 Ma. Granitic leucosomes formed close to peak metamorphic conditions (T>750 degrees C) above muscovite breakdown have their slightly younger character confirmed by a 609 +/- 7 Ma low-Y monazite age. A similar 606 +/- 5 Ma age was obtained for low-Y monazite rims and domains in mesosome and melanosome, and reflects the time of monazite saturation in interstitial granitic melt that was trapped in these layers. Our results confirm that inherited monazite crystals can be preserved during partial melting at temperatures above muscovite breakdown. Moreover, careful textural control aided by X-ray chemical mapping may allow monazite generated at different stages in a similar to 25 Myr prograde metamorphic path to be identified and dated using an electron microprobe. (C) 2008 Elsevier B.V. All rights reserved.

THE EXTENT OF MULTIDISCIPLINARY AUTHORSHIP OF ARTICLES ON SCIENTOMETRICS AND BIBLIOMETRICS IN BRAZIL

The publications in scientometrics and bibliometrics with Brazilian authorship expanded exponentially in the 1990-2006 period, reaching 13 times in the Web of Science database and 19.5 times in the Google Scholar database. This increase is rather superior to that of the total Brazilian scientific production in the same time period (5.6 times in the Web of Science). Some characteristics to be noticed in this rise are: 1) The total number of articles during this period was 197; in that, 78% were published in 57 Brazilian journals and 22% in 13 international journals. 2) The national and international articles averaged 4.3 and 5.9 citations/article, respectively; two journals stood out among these, the national Ciencia da Informacao (44 articles averaging 6.7 citations/article) and the international Scientometrics (32 articles averaging 6.2 citations/article). 3) The articles encompass an impressive participation of authors from areas other than information science; only one-fourth of the authors are bound to the information science field, the remaining ones being distributed among the areas of humanities/business administration, biology/biomedicine, health and hard sciences. The occurrence of adventitious authors at this level of multidisciplinarity is uncommon in science. However, the possible benefits of such patterns are not clear in view of a fragmented intercommunication among the authors, as noticed through the citations. The advantages of changing this trend and of using other scientometric and bibliometric databases, such as SciELO, to avoid an almost exclusive use of the Web of Science database, are discussed.