Infanticide by male house sparrows: gaining time or manipulating females?

The killing of genetically unrelated young by males has been viewed as a strategy that forces victimized females to advance the onset of their next fertile period, thus infanticidal males gain a time advantage that may be crucial to maximize reproductive success. Among females that may raise several broods in a year, a failure occurring relatively earlier in the time-course of the previous breeding attempt may result in an increased investment in the next breeding attempt. This female strategy may be exploited by males in their own interest, and may strongly select for male infanticidal behaviour. I demonstrate that, in the house sparrow, females mated with infanticidal males re-laid earlier, initiated more breeding attempts and fledged more offspring than females mated with non-infanticidal males. These results suggest that both the time saving and the manipulation of female investment are independent mechanisms conferring advantages that may have selected for male infanticide in the studied population.     

Population growth rate of the depredating Podisus nigrispinus (Heteroptera: Pentatomidae) and of the Tuta absoluta (Leptoptera: gelechiidae) in wintering place

The fertility life table of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) preying either on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) caterpillars or on alternative prey Tenebrio molitor L. (Coleoptera: Tenebrionidae) under greenhouse conditions (30 +/- 5 degrees C, 61 +/- 23% RH) were studied. The life table was also determined for the pest T. absoluta under the same conditions. The net reproductive rate (Ro) and the intrinsic rate of natural increase (rm) were higher 14.13 and 46.32 times for predators fed on T. molitor prey, however, the generation time (T) was similar between prey. The pest T. absoluta showed Ro and rm higher 2.15 and 32.10 times than those achieved for predators fed on this pest. However, females fed on a suitable prey T. molitor showed higher Ro and rm than those yielded for the pest. The survival curves were similar for P. nigrispinus females fed on both prey and classified as being type II by Weibull analysis. The results suggest that P. nigrispinus is able to maintain its population preying only on T. absoluta caterpillars; however, the life table parameters determined individually for both showed that the pest produces more generations per year and faster population natural growth than the predator.     

Building Capacity in Small-Scale Mining Communities: Health,Ecosystem Sustainability,and the Global Mercury Project

The Global Mercury Project (GMP) is an initiative of the United Nations in collaboration with numerous government and nongovernment organizations to promote knowledge and capacity building on the links between small-scale gold mining practices and health, ecosystem, and social factors, and to implement interventions that reduce mercury pollution and exposure caused by mining activities in developing countries. Knowledge regarding the use of mercury and the dynamics of complex environmental, health, socioeconomic, and cultural conditions in and surrounding small-scale mining sites is particularly needed for the purpose of developing appropriate community-based measures to reduce mercury-related problems. GMP strategies aim to build upon local knowledge and practices to train miners on the use of cleaner and affordable technologies of mining and mineral processing in order to minimize negative impacts. The initiative is especially proactive in facilitating transdisciplinary and participatory models of community interaction, involving local, regional, and international stakeholders in each of the strategy design, community assessment, and community intervention phases. The six participating countries are Brazil, Indonesia, Lao People’s Democratic Republic, Sudan, Tanzania, and Zimbabwe. This article outlines GMP’s objectives and scope of activities and also highlights achievements, challenges, and opportunities for future development.     

Feathers at nests are potential female signals in the spotless starling

Although the presence of feathers in the nest is widespread among birds, it has not been previously suggested that feathers can be used as sexual signals. Females of the spotless starling (Sturnus unicolor) regularly carry feathers to their nest, mostly during laying and incubation. We show that the arrangement of these feathers was non-random with respect to the side (obverse or reverse) placed upwards (which can be viewed from the nest entrance). Feathers of the wood pigeon (Columba palumbus) and the spotless starling, which exhibit higher ultraviolet and visible reflectance on their reverse side, were predominantly placed with this side upwards. On the contrary, feathers of the jay (Garrulus glandarius) were predominantly found exhibiting the obverse side, which possesses higher reflectance in this species. Feathers of the azure-winged magpie (Cyanopica cyana), with similar reflectance values on either side, were placed indiscriminately in obverse and reverse positions. The results suggest that feathers are arranged to maximize their conspicuousness within the nest and hence that they might be potentially used as intraspecific signals.     

Coliform concentration reduction and related performance evaluation of a down-flow anaerobic fixed bed reactor treating low-strength saline wastewater

Low-strength saline wastewater may be generated by tourist facilities, industries and communities located in coastal areas. Sea salts, mostly chlorides, when present in wastewaters at high concentrations, can cause inhibition on biological treatment processes. In this study, a laboratory down-flow anaerobic fixed bed reactor (DFAFBR) was used for treating saline wastewater. This wastewater was simulated by dilution of piggery manure in a synthetic saline water to obtain a final total COD concentration in the range of 1100-2900 mg/l and a salt concentration of 15 g/l. The DFAFBR was operated at hydraulic retention times (HRT) of 96, 48, 24 and 12 h. The results showed that at sea salts concentrations in the range from 5 to 15 g/l, total coliform concentration reduction efficiencies higher than 97% were achieved. A decrease in the total and faecal coliform concentration reduction efficiencies from 99.5% to 90.5% and 92.5%, respectively, was observed when the HRT decreased from 96 to 12 h. Enumeration of coliform bacteria isolated from the biofilm in different zones of the reactor showed that more than 94% of the total amount was removed in the upper zone. A HRT of 24 h was required to obtain total COD, organic-N, total-P and faecal coliform concentration reduction efficiencies higher than 72%, 51%, 39% and 98%, respectively. A concentration of 8.4 g/l for chlorides, 1.25 g/l for sulphates and 4.6 g/l for sodium did not affect the process performance.     

Construction and characterization of a minimized version of the HIV-1 pNL4-3 plasmid and its application for pseudotyping HIV-1 vectors

The pUC-based pNL4-3 plasmid is the most widely used vector for in vitro manipulations of the HIV-1 proviral sequences. We have developed a minimal plasmid (pCHUS) based on pNL4-3, which may be useful to facilitate the design of HIV-based constructions. The strategy that has allowed us to construct pCHUS includes the following steps: (1) pNL-3 digestion by using restriction sites contained within the long terminal repeats (LTRs), (2) recircularization of the fragment containing the pUC18 sequence, (3) amplification of the LTR region restored in the previous step, (4) double digestion of the products obtained in steps 2 and 3, (5) ligation of the fragment containing ColE1+Amp^R with the LTR fragment, (6) linearization of the intermediate plasmid obtained, and (7) insertion of the fragment containing the proviral genome into the linearized vector. The pCHUS plasmid includes essential information for its replication and antibiotic selection in bacteria, but it lacks all the unnecessary sequences. Our results suggest that pCHUS may be more advantageous than pNL4-3 for in vitro manipulation of the HIV-1 proviral genome. In addition, we describe a potential application of this new vector for pseudotyping HIV-1 particles, using a single plasmid transfection, as a more helpful alternative to the traditionally used cotransfection method.     

Structural and hemostatic activities of a sulfated galactofucan from the brown alga Spatoglossum schroederi. An ideal antithrombotic agent?

The brown alga Spatoglossum schroederi contains three fractions of sulfated polysaccharides. One of them was purified by acetone fractionation, ion exchange, and molecular sieving chromatography. It has a molecular size of 21.5 kDa and contains fucose, xylose, galactose, and sulfate in a molar ratio of 1.0:0.5:2.0:2.0 and contains trace amounts of glucuronic acid. Chemical analyses, methylation studies, and NMR spectroscopy showed that the polysaccharide has a unique structure, composed of a central core formed mainly by 4-linked beta-galactose units, partially sulfated at the 3-O position. Approximately 25% of these units contain branches of oligosaccharides (mostly tetrasaccharides) composed of 3-sulfated, 4-linked alpha-fucose and one or two nonsulfated, 4-linked beta-xylose units at the reducing and nonreducing end, respectively. This sulfated galactofucan showed no anticoagulant activity on several "in vitro" assays. Nevertheless, it had a potent antithrombotic activity on an animal model of experimental venous thrombosis. This effect is time-dependent, reaching the maximum 8 h after its administration compared with the more transient action of heparin. The effect was not observed with the desulfated molecule. Furthermore, the sulfated galactofucan was 2-fold more potent than heparin in stimulating the synthesis of an antithrombotic heparan sulfate by endothelial cells. Again, this action was also abolished by desulfation of the polysaccharide. Because this sulfated galactofucan has no anticoagulant activity but strongly stimulates the synthesis of heparan sulfate by endothelial cells, we suggested that this last effect may be related to the "in vivo" antithrombotic activity of this polysaccharide. In this case the highly sulfated heparan sulfate produced by the endothelial cells is in fact the antithrombotic agent. Our results suggested that this sulfated galactofucan may have a potential application as an antithrombotic drug.     

Cyanide-resistant respiration is frequent, but confined to yeasts incapable of aerobic fermentation

In Pichia membranifaciens, cyanide-resistant respiration (CRR) sensitive to salicylhydroxamic acid emerged after forced aeration of starved cells for 4 h. Surveying a large number of species by this simple methodology, we found that CRR is very frequent among yeasts. Remarkably, considering our results together with previous data in the literature, CRR was present in 24 out of 28 non-fermentative or Crabtree-negative yeasts and absent in 10 out of 12 Crabtree-positive yeasts. We submit that, as alternatives to cytochromic respiration, yeasts developed two strategies: either aerobic fermentation in Crabtree-positive yeasts or CRR in non-fermentative or Crabtree-negative yeasts.