Search results for " life cycle"
showing 10 items of 158 documents
Evolutionary Hysteresis and Ratchets in the Evolution of Periodical Cicadas
2019
It has been previously hypothesized that the perfectly synchronized mass emergence of periodical cicadas (Magicicada spp.) evolved as a result of a switch from size-based to age-based emergence. In the former case, cicada nymphs emerge immediately (at the first opportunity) on reaching maturity, whereas in the latter case, nymphs wait in order to emerge at a specific age. Here we use an individual-based model to simulate the cicada life cycle and to study the evolution of periodicity. We find that if age-based emergence evolves in a constant abiotic environment, it typically results in a population that is protoperiodic, and synchronous emergence of the whole population is not achieved. How…
Plant growth promoting potential of bacterial endophytes from three terrestrial mediterranean orchid species
2020
Orchids are highly dependent on symbiotic microorganisms during their entire life cycle. Whereas an important role in orchid seed germination and early plant development is well established for mycorrhizal fungi, the influence of endophytic bacteria on orchid growth has been less investigated. Here, we report the isolation of endophytic bacteria from different organs of three terrestrial Mediterranean orchid species (Spiranthes spiralis, Serapias vomeracea and Neottia ovata), the investigation of their potential Plant Growth-Promoting (PGP) traits and their interaction with the orchid mycorrhizal (OM) fungus Tulasnella calospora in vitro. Little overlap was found among endophytic bacteria i…
Candidate Targets for Hepatitis C Virus-Specific Antiviral Therapy
1997
The hepatitis C virus (HCV) was identified as the major causative agent of posttransfusion and community-acquired non-A, non-B hepatitis throughout the world. It is an enveloped virus with a plus-strand RNA genome encoding a polyprotein of about 3,010 amino acids. This polyprotein is cleaved co- and posttranslationally into mature viral proteins by host cell signal peptidases and 2 viral enzymes designated the NS2-3 proteinase and the NS3/4A proteinase complex. It is assumed that virus replication takes place in a membrane-associated complex containing at least 2 viral enzymatic activities: the NS3 nucleoside triphosphatase (NTPase)/helicase and the NS5B RNA-dependent RNA polymerase (RdRp).…
Chronic toxicity of methylparathion to the rotifer Brachionus calyciflorus fed on Nannochloris oculata and Chlorella pyrenoidosa
1993
The effect of sublethal levels of methylparathion (0,1, 3, 5, 7 mg 1−1) on the freshwater rotifer, Brachionus calyciflorus, during their entire life cycle was studied. Rotifers were fed on two species of unicellular algae: Nannochloris oculata and Chlorella pyrenoidosa; both algal concentrations were 5 × 105 cell ml−1.
New exergy criterion in the multicriteria context: a life cycle assessment of two plaster products
2003
This paper deals with the exergy analysis (EXA) of plaster materials and ranks the environmental burdens due to the production of such materials. The calculation of the exergy loss during the whole examined process represents a relevant index, looking at the technology improvement of a process, as a suitable tool in aid of the trade-off of alternative materials in the decision making. A life cycle inventory is performed for building plaster products and the matrix method is used. The authors extend the application of EXA to life cycle assessment, conducting an exergetic life cycle assessment, and propose an exergetic index in the framework of multi-criteria decision making. An exergy balanc…
Layered dry envelope insulated with sheep wool-lime mix
2014
This poster describes the results of a research aimed to design and assess a new layered envelope component that might be implemented on buildings of the Mediterranean area, in order to improve the energy efficiency and the environmental sustainability. These goals have been achieved by means of the use of local and natural building materials or arising from renewable resources. In particular, thermal insulating has been realize utilizing a mix of natural and mineral materials, obtaining a biocomposite with comparable building physics and mechanical properties to commonly used building materials. Among natural materials, the sheep wool was chosen since it is, on the hand, a waste to exploit…
Life Cycle Assessment of olive oil: a case study in Southern Italy
2018
The paper describes the results of a specific LCA based analysis of the production of oil in the region of Calabria, in southern Italy. The goal of the study is to assess the energy and environmental impacts of different scenarios involving conventional and organic cultivations, plains and hills cultivations and involving different operating techniques. The study also aims at assessing the share of each life cycle step on the total of energy and environmental impacts. The functional unit chosen for the comparative analysis is a glass bottle of 0.75 l of extra-vergine oil. A “from cradle to gate” perspective was chosen. The analysis was developed according to the LCA standards of the ISO 140…
Costructal law, exergy analysis and life cycle energy sustainability assessment: an expanded framework applied to a boiler
2020
Purpose Life cycle sustainability assessment (LCSA) is one of the most relevant tools delving in sustainability science, based currently on the triple bottom line idea that is defined as the contemporary implementation of the three tools of life cycle assessment (LCA), life cycle costing (LCC) and social life cycle assessment (S-LCA). The methodology is currently being applied to a wide set of products and systems. However, as per in the large interest towards energy-related products, the sustainability assessment of energy systems—in particular those where fluid streams are used—could be more effective if some further stages could be included in the analysis, i.e. a process level analysis …
Multicriteria-Oriented Optimization of Building Energy Performances: The Annex 72 IEA-EBC Experience
2021
International audience; This chapter describes the research experience of the International Energy Agency-Energy in Buildings and Communities Programme Annex 72 members on the application of multi-objective optimization processes for the selection of design or retrofit actions that allow for improving different aspects (energy, environmental, economic, etc.) of buildings in a life cycle perspective. Thirteen case studies were examined focussing on methodologies, applications and results and deriving generic conclusions and guidelines for building designers and decision-makers.
Parasite specificity in Podarcis bocagei and P. carbonelli (Lacertidae) from NW Portugal: a host-parasite history
2015
Host parasite specificity is related to several factors including the type of life cycle of the parasite, the habitat occupied by both parasites and hosts, and the food habits of the hosts. In this work, gastrointestinal helminths in two congeneric lacertid lizards, Podarcis bocagei and Podarcis carbonelli living in sintopy, have been analysed. Out of four helminth species found, three of them, the trematode Brachylaima sp., the cestode Oochoristica gallica and the nematode Skrjabinelazia hoffmanni, have indirect life cycles while the nematode Spauligodon carbonelli has a direct life cycle. Heteroxenous helminths showed low host specificity whereas S. carbonelli may be placed at an intermed…