Assessing the effects of habitat characteristics and co-occurrence with closely related species on occupancy of resident ‘wood-warblers’ in a Neotropical working landscape

The simultaneous effects of habitat traits and interspecific interactions determine the occurrence and habitat use of wildlife populations. However, little research has been devoted to examining spatial co-occurrence among closely related species while considering the effect of habitat variation and imperfect detectability of species in the field. In this study, we focused on migratory and resident 'wood-warblers' that coexist during the winter in a Neotropical working landscape in southern Mexico to understand if habitat occupancy of resident wood-warblers is influenced by habitat characteristics and by the presence of other species of resident and migratory wood-warblers. For this purpose, we implemented two-species occupancy models, which account for the imperfect detectability of these birds in the field. Our results revealed that habitat occupancy of resident wood-warblers was positively influenced by the presence of other closely related species (both migratory and resident). These positive relationships may be explained by the fact that different species of wood-warblers frequently participate in mixed-species flocks. However, these patterns of species co-occurrence were more evident among resident species than between migratory and resident species, which may be explained by micro-habitat segregation and differences in behaviours between resident and migratory wood-warblers. We also found that some habitat characteristics may mediate the observed patterns of species co-occurrence. Specifically, sites with larger trees were associated with the co-occurrence of some species of resident wood-warblers. In addition, we discuss the possibility that species co-occurrence might be the result of shared preferences for environmental factors that we did not consider. Our study highlights the importance of the interplay between species co-occurrence and habitat traits in determining the presence and habitat use of resident birds in Neotropical working landscapes.     

Common dolphinfish,Coryphaena hippurus,spawn at their easternmost Atlantic range adjacent to the Mediterranean Sea

This study provides sound evidence of the spawning activity of common dolphinfish (Coryphaena hippurus) in the Gulf of Cadiz (southwest Spain) during summer months. Along with waters off Côte d'Ivoire, this area adjacent to the Mediterranean Sea is the easternmost Atlantic spawning ground documented for the species. All the fish analysed (5 males and 15 females) were at spawning stage, except the smallest female (61.5 cm in fork length), which might not have yet reached sexual maturation. The oceanographic conditions during the samplings were similar to those occurring during the peak spawning season in the Gulf of Mexico. The study results are consistent with recent genetic studies indicating differentiation between Mediterranean and Atlantic dolphinfish populations, with the Strait of Gibraltar representing a boundary between two distinct reproductive units. The present results may contribute to improve the understanding of the dynamics of dolphinfish population and the management of eastern Atlantic and Mediterranean stocks.     

Progesterone and a phospholipase inhibitor increase the endosomal bis(monoacylglycero)phosphate content and block HIV viral particle intercellular transmission

Progesterone, the cationic amphiphile U18666A and a phospholipase inhibitor (Methyl Arachidonyl Fluoro Phosphonate, MAFP) inhibited by 70%–90% HIV production in viral reservoir cells, i.e. human THP-1 monocytes and monocyte-derived macrophages (MDM). These compounds triggered an inhibition of fluid phase endocytosis (macropinocytosis) and modified cellular lipid homeostasis since endosomes accumulated filipin-stained sterols and Bis(Monoacylglycero)Phosphate (BMP). BMP was quantified using a new cytometry procedure and was increased by 1.25 times with MAFP, 1.7 times with U18666A and 2.5 times with progesterone. MAFP but not progesterone or U18666A inhibited the hydrolysis of BMP by the Pancreatic Lipase Related Protein 2 (PLRP2) as shown by in-vitro experiments. The possible role of sterol transporters in steroid-mediated BMP increase is discussed.     

Species richness and endemicity in the Spanish vascular flora

Data from an updated and revised checklist of the Spanish flora is analyzed. The Spanish vascular plant flora is composed of 204 families, 1433 genera and 7071 species. Floristic data are analysed by considering three regions: mainland Spain with 5984 species, the Balearic Islands with 1521 species and Canary Islands with 2066 species. Extinct species are included in the analysis, with an extinction rate of 0.35% of the flora. A total of 1488 endemic species are recognized, which account for 21% of the Spanish flora. The rate of endemism in the Canary Islands is 25.9%, considerably higher than for the Balearic Islands (6.9%) and for mainland Spain (13.8%). A list of the 35 strict endemic genera is compiled, of which 65.7% are Canarian, and another list of 27 subendemic genera of which 48.1% are also Canarian. An estimated 12% of the Spanish flora is non‐native, with large variation between the 20.7% of the Canary flora, 10.5% of mainland Spain and 9.7% of the Balearic Islands. Finally, the composition of the Spanish flora for large groups and families is ana lysed. The data show that species richness and endemicity rates have been overestimated by previous authors, and are similar to other Mediterranean countries. It is concluded that a complete revision of the Macaronesian flora is strongly needed to obtain an accurate comparison with the flora of other areas.     

Mapping Dominican transnationalism: narrow and broad transnational practices

This article maps the structure for understanding the Dominican transnational field. By transnational field we refer to a web of linkages that affects the lives of Dominicans in their places of residence in every social field. We find that social boundaries of the nation do not coincide with political ones and the degree of participation in transnational exchanges varies. We suggest that the structure of the transnational social field is better understood by establishing and defining broad and narrow transnational social practices.     

Isolation and Characterization of Mercury Resistant Bacillus sp. from Soils with an Extensive History as Substrates for Mercury Extraction in Mexico

Metal phytoextraction assisted by bacteria plays an important role in bioremediation systems. In this work, mercury-resistant bacterial strains were isolated from soils with high levels of mercury (San Joaquin, Queretaro State, Mexico) and identified as Bacillus sp. based on the 16S rDNA gene sequence analysis. The bacterial strains were found to exhibit different multiple mercury-resistance and carbon source utilization characteristics. The mercury reduction ability was tested through a volatilization assay. The bacterial isolates were also evaluated for their ability to promote growth and mercury uptake in tomato plants. In a roll towel assay, the maximum vigor index of tomato plants was obtained with the inoculation of Bacillus sp. A2, A12, B11, B15 and C1, while in a pot assay, the maximum vigor index was obtained with the inoculation of Bacillus sp. A6, A7 and B20, compared with un-inoculated controls in the presence of HgCl₂. Maximum Hg accumulation in the roots and shoots of tomato plants was obtained only with Bacillus sp. A7 in the roll towel assay, whereas in the pot assay, maximum accumulation was obtained with Bacillus sp. A12 compared with un-inoculated controls. Our results show that mercury accumulation in tissue is enhanced by these plant growth promoting bacterial strains, which recommends their possible use as microbe-assisted phytoremediation systems in mercury-polluted soils.     

Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin,Venezuela

To explore the effects of deforestation and resulting differences in vegetation and land cover on entomological parameters, such as anopheline species composition, abundance, biting rate, parity and entomological inoculation rate (EIR), three villages were selected in the Lower Caura River Basin, state of Bolívar, Venezuela. All-night mosquito collections were conducted between March 2008-January 2009 using CDC light traps and Mosquito Magnet^(r) Liberty Plus. Human landing catches were performed between 06:00 pm-10:00 pm, when anophelines were most active. Four types of vegetation were identified. The Annual Parasite Index was not correlated with the type of vegetation. The least abundantly forested village had the highest anopheline abundance, biting rate and species diversity. Anopheles darlingi and Anopheles nuneztovari were the most abundant species and were collected in all three villages. Both species showed unique biting cycles. The more abundantly forested village of El Palmar reported the highest EIR. The results confirmed previous observations that the impacts of deforestation and resulting changes in vegetation cover on malaria transmission are complex and vary locally.     

Occurrence of Poecilochirus austroasiaticus (Acari: Parasitidae) in forensic autopsies and its application on postmortem interval estimation

Despite the fact that mites were used at the dawn of forensic entomology to elucidate the postmortem interval, their use in current cases remains quite low for procedural reasons such as inadequate taxonomic knowledge. A special interest is focused on the phoretic stages of some mite species, because the phoront-host specificity allows us to deduce in many occasions the presence of the carrier (usually Diptera or Coleoptera) although it has not been seen in the sampling performed in situ or in the autopsy room. In this article, we describe two cases where Poecilochirus austroasiaticus Vitzthum (Acari: Parasitidae) was sampled in the autopsy room. In the first case, we could sample the host, Thanatophilus ruficornis (Küster) (Coleoptera: Silphidae), which was still carrying phoretic stages of the mite on the body. That attachment allowed, by observing starvation/feeding periods as a function of the digestive tract filling, the establishment of chronological cycles of phoretic behavior, showing maximum peaks of phoronts during arrival and departure from the corpse and the lowest values in the phase of host feeding. From the sarcosaprophagous fauna, we were able to determine in this case a minimum postmortem interval of 10 days. In the second case, we found no Silphidae at the place where the corpse was found or at the autopsy, but a postmortem interval of 13 days could be established by the high specificity of this interspecific relationship and the departure from the corpse of this family of Coleoptera.     

The study of habitat use by censuses and molecular methods in birds: the case of two sympatric pigeons

Capsule Faecal DNA gives accurate results of habitat use.