Biodegradability of Thermally Aged PHB,PHB-V,and PCL in Soil Compostage

The biodegradability of poly--hydroxybutyrate (PHB), poly--hydroxybutyrate-co-valerate (PHB-V) and poly--caprolactone (PCL) were examined following thermal aging in an oven for 192, 425 and 600 h. Different temperatures, 100, 120 and 140°C for PHB and PHB-V and 30, 40 and 50^oC for PCL were used to assess the influence of this parameter on biodegradation. The biodegradability tests were done in soil compostage at pH 11.0 and involved measuring the residual mass of polymer. Thermal analysis of the polymers was done using a differential scanning calorimeter (DSC). The melting temperature and crystallinity were also determined. Thermal ageing increased the biodegradability only for PHB at 120 and 140^oC, and there was no correlation between crystallinity and the biodegradation of the polymers.     

Assessment of plastic lumber production in Brazil as a substitute for natural wood

Environment, Development and Sustainability - This review aimed to analyze plastic lumber manufacturing in Brazil, a country with a large amount of natural wood, and devise strategies to boost...     

接种不同普通活性污泥培养厌氧氨氧化污泥的研究

采用厌氧氨氧化反应器（ASBR）,分别以普通厌氧活性污泥、混合污泥、好氧活性污泥为种泥,通过对氨氮,NO2^--N等指标监测、分析及污泥颜色的观察,研究采用不同普通活性污泥为种泥启动ASBR的可行性及差异。结果表明．ASBR反应器A和B成功启动,C因反应器故障．启动失败。采用厌氧活性污泥为接种污泥（反应器A）,当进水N的容积负荷为kg／（m^3·d）时,氨氮平均去除率为14.4％。P（NO2^--N）：p（NH4^＋-N）变化量为1．24。采用混合污泥为接种污泥（反应器B）．N的容积负荷于前者相同时,氨氮去除率平均29．7％,p（NO2^--N）：p（NH4^＋-N）变化量为1．27。采用混合普通活性污泥作为种泥培养厌氧氨氧化污泥优于单一厌氧普通活性污泥。     

How ants determine the number of potential recruits

In this paper we present a model that determines the number of potential recruits of Lasius niger, when feeding on a liquid sugar source. The core of the model are two rules: (i) there is a number of workers (facultative foragers) that become potential recruits if starved and (ii) facultative foragers are more likely to become starved than nonforagers because they are more likely to donate food in a trophallaxis (sugar-exchange) event. We develop and explore an analytical model based on these rules, deriving the number of potential recruits after an arbitrary period of starvation. We develop a simplified recruitment model and observe that the predictions of the model are in rough agreement with the empirical data.     

Cytogenetic analysis of human oocytes after subzonal insemination

Subzonal insemination has been proposed to achieve fertilization in cases where standard in vitro fertilization has failed. We present the results of chromosome analysis of oocytes after subzonal insemination. Our data suggest that the main cause (76 per cent) of the absence of cleavage after subzonal insemination is the total absence of sperm nucleus evolution of the injected spermatozoa. Our results also suggest that spermatozoa chromatin development is normal after subzonal insemination. Aneuploidy does not seem to be increased in zygotes after subzonal insemination. However, polyploidy was often more important than predicted by the observation of pronuclei (PN). Pronucleus development might be asynchronous and can appear earlier or later than after standard IVF. The cytogenetic risk after subzonal insemination might therefore be triploidy (if a triploid egg is transferred, because only 2 PN were seen) rather than aneuploidy or structural abnormalities.     

Correction to: Ecological restoration as a strategy for mitigating and adapting to climate change: lessons and challenges from Brazil

Mitigation and Adaptation Strategies for Global Change - The original version of the article unfortunately contained an error.     

Behavioural determinants of gene flow in the bat Miniopterus schreibersii

Dispersal and migratory behaviours are often important determinants of gene flow in wild species, and we have studied their role using ringing-recapture data in the Portuguese population of Miniopterus schreibersii, a cave-dwelling bat that forms large maternity colonies. Juvenile dispersal, usually a major agent of gene flow, appears to be negligible, as young females never settled to give birth in foreign colonies. Likewise, there was virtually no dispersal of adult females to foreign maternity colonies. This strong philopatry virtually eliminated female-mediated gene flow, but we found a great potential for male-mediated gene flow among colonies, as regional migrations temporarily joined both sexes from different colonies in the same roosts, during the mating season. In fact, females from some colonies were more likely to mate with males from foreign colonies than from their own, thus potentially bringing home genes of foreign males. In spite of this abundant gene flow, we found a pattern of isolation by distance and even strong barriers to gene flow, which is explained by the fact that migrations were usually too short to allow direct flow among distant colonies. We concluded that potential gene flow is influenced by the distance between colonies and the availability of mating roosts between them. In addition, we found this flow to be asymmetrical, with a dominant direction from the largest to the smallest colonies. Our ringing-recapture estimates of potential gene flow based on dispersal and migratory behaviour are compatible with the genetic structure of the population for both nuclear and mitochondrial DNA. Our conclusions have implications for the conservation of bats with a spatial behaviour similar to that of M. schreibersii. Colonies should be managed individually because strict female philopatry not only promotes their isolation but also minimises the contribution of immigration in rescuing declining colonies. Furthermore, the results underline the importance of preserving mating roosts to maintain gene flow among colonies.     

Connectivity between countries established by landbirds and raptors migrating along the African–Eurasian flyway

The conservation of long-distance migratory birds requires coordination between the multiple countries connected by the movements of these species. The recent expansion of tracking studies is shedding new light on these movements, but much of this information is fragmented and inaccessible to conservation practitioners and policy makers. We synthesized current knowledge on the connectivity established between countries by landbirds and raptors migrating along the African–Eurasian flyway. We reviewed tracking studies to compile migration records for 1229 individual birds, from which we derived 544 migratory links, each link corresponding to a species’ connection between a breeding country in Europe and a nonbreeding country in sub-Saharan Africa. We used these migratory links to analyze trends in knowledge over time and spatial patterns of connectivity per country (across species), per species (across countries), and at the flyway scale (across all countries and all species). The number of tracking studies available increased steadily since 2010 (particularly for landbirds), but the coverage of existing tracking data was highly incomplete. An average of 7.5% of migratory landbird species and 14.6% of raptor species were tracked per country. More data existed from central and western European countries, and it was biased toward larger bodied species. We provide species- and country-level syntheses of the migratory links we identified from the reviewed studies, involving 123 populations of 43 species, migrating between 28 European and 43 African countries. Several countries (e.g., Spain, Poland, Ethiopia, Democratic Republic of Congo) are strategic priorities for future tracking studies to complement existing data, particularly on landbirds. Despite the limitations in existing tracking data, our data and results can inform discussions under 2 key policy instruments at the flyway scale: the African–Eurasian Migratory Landbirds Action Plan and the Memorandum of Understanding on the Conservation of Migratory Birds of Prey in Africa and Eurasia.     

Anaerobic whey treatment by a stirred sequencing batch reactor (ASBR): effects of organic loading and supplemented alkalinity

An assessment was made of cheese whey treatment in a mechanically stirred anaerobic sequencing batch reactor (ASBR) containing granular biomass. The effect of increasing organic load and decreasing influent alkalinity supplementation (as sodium bicarbonate) was analyzed. The reactor operated on 8-h cycles with influent COD concentrations of 500, 1000, 2000 and 4000 mg/L, corresponding to volumetric organic loads of 0.6 to 4.8 mgCOD/L.d. Organic COD removal efficiencies were always above 90% for filtered samples. These results were obtained with an optimized alkalinity supplementation of 50% (ratio between mass of NaHCO3 added and mass of influent mgNaHCO3/mgCOD) in the assays with 500 and 1000 mgCOD/L and of 25% in the assays with 2000 and 4000 mgCOD/L. Initial alkalinity supplementation was equal to the mass of influent COD (100%). The system showed formation of viscous polymer-like substances. These were probably of microbiological origin occurring mainly at influent CODs of 2000 and 4000 mg/L and caused some biomass flotation. This could, however be controlled to enable efficient and stable reactor operation.