IMPACT World+: a globally regionalized life cycle impact assessment method

The International Journal of Life Cycle Assessment - This paper addresses the need for a globally regionalized method for life cycle impact assessment (LCIA), integrating multiple state-of-the-art...     

Acetic acid bacteria encode two levansucrase types of different ecological relationship

Acetic acid bacteria (AAB) are associated with plants and insects. Determinants for the targeting and occupation of these widely different environments are unknown. However, most of these natural habitats share plant-derived sucrose, which can be metabolized by some AAB via polyfructose building levansucrases (LS) known to be involved in biofilm formation. Here, we propose two LS types (T) encoded by AAB as determinants for habitat selection, which emerged from vertical (T1) and horizontal (T2) lines of evolution and differ in their genetic organization, structural features and secretion mechanism, as well as their occurrence in proteobacteria. T1-LS are secreted by plant-pathogenic α- and γ-proteobacteria, while T2-LS genes are common in diazotrophic, plant-growth-promoting α-, β- and γ-proteobacteria. This knowledge may be exploited for a better understanding of microbial ecology, plant health and biofilm formation by sucrase-secreting proteobacteria in eukaryotic hosts.     

Genetic Structure of Wild Bonobo Populations: Diversity of Mitochondrial DNA and Geographical Distribution

Bonobos (Pan paniscus) inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits of the species’ range. In 136 effective samples from different individuals (range: 7–37 per population), we distinguished 54 haplotypes in six clades (A1, A2, B1, B2, C, D), which included a newly identified clade (D). MtDNA haplotypes were regionally clustered; 83 percent of haplotypes were locality-specific. The distribution of haplotypes across populations and the genetic diversity within populations thus showed highly geographical patterns. Using population distance measures, seven populations were categorized in three clusters: the east, central, and west cohorts. Although further elucidation of historical changes in the geological setting is required, the geographical patterns of genetic diversity seem to be shaped by paleoenvironmental changes during the Pleistocene. The present day riverine barriers appeared to have a weak effect on gene flow among populations, except for the Lomami River, which separates the TL2 population from the others. The central cohort preserves a high genetic diversity, and two unique clades of haplotypes were found in the Wamba/Iyondji populations in the central cohort and in the TL2 population in the eastern cohort respectively. This knowledge may contribute to the planning of bonobo conservation.     

Learning-by-doing: experience from 20 years of teaching LCA to future engineers

Purpose

In support of the sustainable development of our societies, future engineers should have elementary knowledge in sustainability assessment and use of life cycle assessment. Publications on pedagogical experience with teaching life cycle assessment (LCA) in high-level education are however scarce. Here, we describe and discuss 20 years of experience in teaching LCA at MSc level in an engineering university with the ambition to share our insights and inspire teaching of LCA as part of a university curriculum.

Methods

We detail the design of an LCA course taught at the Technical University of Denmark since 1997. The course structure relies on (i) a structured combination of theoretical teaching, practical assignments and hands-on practice on LCA case studies, and (ii) the conduct of real-life LCA case studies in collaboration with companies or other organisations. Through the semester-long duration of the course, students from different engineering backgrounds perform full-fledged LCA studies in groups, passing through two iterations—a screening LCA supporting a more targeted LCA.

Results and discussion

The course design, which relies on a learning-by-doing principle, is transparently described to inspire LCA teachers among the readers. Historical evolution and statistics about the course, including its 192 case studies run in collaboration with 105 companies and institutions, are analysed and serve as basis to discuss the benefits and challenges of its different components, such as the theory acquisition, the assignment work, the LCA software learning, the conduct of case studies, the merits of industrial collaborations and grading approaches.

Conclusions

We demonstrate the win-win situation created by the setting of the course, in which the students are actively engaged and learn efficiently how to perform an LCA while the collaborating companies often get useful insights into their analysed case studies. The course can also be an eye opener for companies unfamiliar with LCA, who get introduced to life cycle thinking and the potential benefits of LCA. We have no hesitation in recommending industries and LCA teachers to engage into such collaborations even in the fundamental teaching of LCA techniques.

     

Differentiated influence of off-road and on-road cycling practice on balance control and the related-neurosensory organization

This study aimed to determine the sensorimotor strategies privileged by mountain bikers (MTB) and road cyclists (RC) for balance control. Twenty-four MTB and 24 RC (off-road Olympics, world, continental and national champions, Tour-de-France participants, on-road world cup race winner) volunteered to answer a questionnaire about the characteristics of cycling practice and perform a sensory organization test, aiming to evaluate balance control in 6 different sensory situations based upon visual and support surface perturbations (C1^ES to C6^ES). RC balance performances were better than those of MTB both during quiet stance eyes opened (C1^ES, p = 0.011) and when only somatosensory information is disrupted (C4^ES, p = 0.039), highlighting a higher use of vision to control balance in RC. Moreover, a positive correlation was shown in the whole population (MTB + RC) between the visual ratio (R^VIS = C4^ES/C1^ES) and the proportion of riding distance of on-road cycling (ρ = 0.28, p = 0.054). In MTB, the use of proprioception (somatosensory ratio: R^SOM = C2^{ES(eyes closed)}/C1^ES) was increased by a higher intensity of off-road cycling (ρ = 0.49, p = 0.018) and that of vision (R^VIS) by a higher intensity of on-road cycling (ρ = 0.41, p = 0.048). The difference in sensory organization between MTB and RC could be explained by adaptive processes elaborated from environmental stimulations and technical specificities of these disciplines.     

Birds of Antioquia: Georeferenced database of specimens from the Colección de Ciencias Naturales del Museo Universitario de la Universidad de Antioquia (MUA)

The department of Antioquia, Colombia, lies in the northwestern corner of South America and provides a biogeographical link among divergent faunas, including Caribbean, Andean, Pacific and Amazonian. Information about the distribution of biodiversity in this area is of relevance for academic, practical and social purposes. This data paper describes the dataset containing all bird specimens deposited in the Colección de Ciencias Naturales del Museo Universitario de la Universidad de Antioquia (MUA). We curated all the information associated with the bird specimens, including the georeferences and taxonomy, and published the database through the Global Biodiversity Information Facility network. During this process we checked the species identification and existing georeferences and completed the information when possible. The collection holds 663 bird specimens collected between 1940 and 2011. Even though most specimens are from Antioquia (70%), the collection includes material from several other departments and one specimen from the United States. The collection holds specimens from three endemic and endangered species (Coeligena orina, Diglossa gloriossisima, and Hypopirrhus pyrohipogaster), and includes localities poorly represented in other collections. The information contained in the collection has been used for biodiversity modeling, conservation planning and management, and we expect to further facilitate these activities by making it publicly available.     

Adaptive Changes in Postsynaptic Dopamine Receptors Despite Unaltered Dopamine Dynamics in Mice Lacking Monoamine Oxidase B

Monoamine oxidase (MAO) B is considered a key enzyme in dopamine metabolism. The present studies, conducted in MAO B knockout mice, show that lack of MAO B does not alter extracellular levels of dopamine in striatum. Similarly, the synthesis, storage, uptake, and release of dopamine are also unaltered. However, autoradiography revealed a significant up-regulation of the D2-like dopamine receptors in the striatum of MAO B knockout mice. Mutant mice also exhibit a functional supersensitivity of D1-dopamine receptors in the nucleus accumbens. Thus, the agonist SKF 38,393-induced c-Fos immunoreactivity was significantly increased in knockout mice as compared with wild-type controls. In view of the apparently normal basal dopamine dynamics observed in MAO B knockout mice, we hypothesize that a dopamine-independent mechanism underlies adaptations in dopamine receptor function that occur as a consequence of MAO B depletion. Finally, these findings suggest that chronic administration of MAO inhibitors, as occurs in the treatment of Parkinson's disease and depression, may be associated with an increased responsiveness of CNS neurons to dopamine receptor ligands.