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Host shifts of parasites are often causing devastating effects in the new hosts. The Varroa genus is known for a lineage of Varroa destructor that shifted to the Western honey bee, Apis mellifera, with disastrous effects on wild populations and the beekeeping industry. Despite this, the biology of Varroa spp. remains poorly understood in its native distribution range, where it naturally parasitizes the Eastern honey bee, Apis cerana. Here, we combined mitochondrial and nuclear DNA analyses with the assessment of mite reproduction to determine the population structure and host specificity of V. destructor and Varroa jacobsonii in Thailand, where both hosts and several Varroa species and haplotypes are sympatric. Our data confirm previously described mite haplogroups, and show three novel haplotypes. Multiple infestations of single host colonies by both mite species and introgression of alleles between V. destructor and V. jacobsonii suggest that hybridization occurs between the two species. Our results indicate that host specificity and population genetic structure in the genus Varroa is more labile than previously thought. The ability of the host shifted V. destructor haplotype to spillback to A. cerana and to hybridize with V. jacobsonii could threaten honey bee populations of Asia and beyond.
In the current investigation, a novel navigational controller has been designed and implemented for humanoids in cluttered environments. Here, regression analysis is hybridized with genetic algorithm (GA) for designing the controller. The obstacle distances collected in the form of sensor outputs are initially fed to the regression controller; and based on the previous training pattern data, an intermediate advancing angle (AA) is obtained as the first output. The intermediate AA obtained from the regression controller along with other inputs is again fed to the GA controller, which generates the final AA as the desired final output to avoid the obstacles present in a complex environment and reach the destination successfully. The working of the controller is tested on a V-REP simulation platform. In the current work, navigation of both single as well as multiple humanoids has been attempted. To avoid inter-collision among multiple humanoids during their navigation in a common platform, a Petri-Net model has been proposed. The simulation results are validated through a real-time experimental platform developed under laboratory conditions. The results obtained from both the simulation and experimental platforms are compared against each other and are found to be in good agreement with acceptable percentage of errors. Finally, the proposed controller is also compared with other existing navigational controller and an improvement in performance has been observed.
Invasive populations of Dalmation toadflax [Linaria dalmatica (L.) Mill.] and yellow toadflax (Linaria vulgaris Mill.) are widespread throughout the Intermountain West, where gene flow between these nonnative species is producing vigorous and fertile hybrids. These hybrid toadflax populations are less responsive to herbicides than either parent species, and biocontrol agents routinely released on L. dalmatica and L. vulgaris often fail to establish on hybrid hosts. Early detection of hybrid Linaria populations is therefore essential for effective management, but resources are limited for scouting large expanses of range and wildland. We used species distribution modeling to identify environmentally suitable areas for these invasive Linaria taxa in Montana, Wyoming, and Colorado. Areas suitable for hybrid Linaria establishment were estimated using two different modeling approaches: first, based on known hybrid occurrence and associated environmental conditions, and second, based on zones environmentally suitable for co-occurrence of the parent species. This also allowed comparison of different model outputs, especially relevant when modeling emerging invasives, such as novel hybrids, with minimal occurrence data. Combining the two model outputs identified areas at greatest risk of hybrid Linaria invasion, including parts of north-central Montana, where model estimates indicate the hybrid may spread without prior co-invasion of the parents. Potential hybrid hot spots were also identified in western Montana; northwestern, northeastern, and southeastern Wyoming; and the Western Slope and Front Range of Colorado. Despite relatively few confirmed occurrences of hybrid populations to date, our results indicate that extensive spread of hybrid populations is possible within the studied area. Model-based maps of potential Linaria distributions will allow area weed managers to direct limited resources more effectively for locating and controlling these invaders.
To investigate the extent of suspected hybridization between the brolga Antigone rubicunda and the Australian sarus crane Antigone antigone gillae, first noted in the 1970s, we analysed the genetic diversity of 389 feathers collected from breeding and flocking areas in north Queensland, Australia. We compared these with 15 samples from birds of known identity, or that were phenotypically typical. Bayesian clustering based on 10 microsatellite loci identified nine admixed birds, confirming that Australian cranes hybridize in the wild. Four of these were backcrosses, also confirming that wild Australian crane hybrids are fertile. Genetic analyses identified 10 times more hybrids than our accompanying visual field observations. Our analyses also provide the first definitive evidence that both brolgas and sarus cranes migrate between the Gulf Plains, the principal breeding area for sarus cranes, and major non-breeding locations on the Atherton Tablelands. We suggest that genetic analysis of shed feathers could potentially offer a cost-effective means to provide ongoing monitoring of this migration. The first observations of hybrids coincided with significantly increased opportunities for interaction between the two species when foraging on agricultural crops, which have developed significantly in the Atherton Tablelands flocking area since the 1960s. As the sarus crane is declining in much of its Asian range, challenges to the genetic integrity of the Australian sarus crane populations have international conservation significance.
This article investigates the extent to which provincial political parties made use of social media in their strategy, organization and communication in order to achieve their electoral goals during the Quebec 2012 general election. Using data from a series of 19 interviews conducted with online strategists and campaign directors from the five leading parties active in the 2012 election, we identify the strategic objectives these organizations followed when developing their social media campaigns. The strategists' narratives reveal that social media became a central component of electioneering and that parties were carrying out, in various forms, hybrid campaigns that combined traditional and emergent communication technologies and employed both old and new types of organizational principles.
The genus Clinostomoides Dollfus, 1950 was erected to accommodate a single worm from Ardea goliath sampled in the Belgian Congo. The specimen was distinguished from other clinostomids by its large size and posterior genitalia. In the following years, metacercariae of Clinostomoides brieni, have been described in Clarias spp. in southern and western Africa. A few authors have referred to Clinostomum brieni, but all such usages appear to be lapsus calami, and the validity of Clinostomoides remains widely accepted. In this study our aim was: position C. brieni among the growing clinostomids molecular database, and redescribe the species with emphasis on characters that have emerged as important in recent work. We sequenced two nuclear (partial 18S and ITS) and one mitochondrial marker (partial cytochrome c oxidase I) and studied morphology in metacercariae from hosts and localities likely to harbour the type species (Clarias spp., Democratic Republic of the Congo, South Africa). Phylogenetic analysis shows C. brieni belongs within Clinostomum Leidy, 1856. We therefore transfer C. brieni to Clinostomum, amend the diagnosis for the genus Clinostomum and provide a critical analysis of other species in Clinostomoides, all of which we consider species inquirendae, as they rest on comparisons of different developmental stages.
Hybridization events between Schistosoma species (Digenea, Platyhelminthes) are reported with increasing frequency, largely due to improved access to molecular tools. Nevertheless, little is known about the distribution and frequency of hybrid schistosomes in nature. Screening for hybrids on a large scale is complicated by the need for nuclear and mitochondrial sequence information, precluding a ‘simple’ barcoding approach. Here we aimed to determine and understand the spatiotemporal distribution of Schistosoma haematobium × Schistosoma bovis hybrids in the Senegal River Basin. From ten villages, distributed over the four main water basins, we genotyped a total of 1236 schistosome larvae collected from human urine samples using a partial mitochondrial cox1 fragment; a subset of 268 parasites was also genotyped using ITS rDNA. Hybrid schistosomes were unevenly distributed, with substantially higher numbers in villages bordering Lac de Guiers than in villages from the Lampsar River and the Middle Valley of the Senegal River. The frequency of hybrids per village was not linked with the prevalence of urinary schistosomiasis in that village. However, we did find a significant positive association between the frequency of hybrids per village and the prevalence of Schistosoma mansoni. We discuss the potential consequences of adopting a barcoding approach when studying hybrids in nature.
European dry-wood termites belong to the genus Kalotermes (Kalotermitidae), one of the two termite genera in Europe. Until the recent description of two new species, Kalotermes italicus in Italy and Kalotermes phoenicae in the eastern Mediterranean area, Kalotermes flavicollis was the only taxon known in this region. The presence of additional entities, suggested by morphological and physiological variation observed in K. flavicollis, was supported by molecular studies revealing four distinct genetic lineages: lineage A, K. flavicollis sensu strictu, from the Aegean area to Italy; lineage B, in Tuscany; lineage SC, in Sardinia and Corsica; lineage SF, in southern France. Lineages A and B may form mixed colonies, suggesting hybridization. To draw a more detailed picture of Kalotermes evolution and biogeography in Europe, we analyzed samples from previously unsampled areas, such as Spain and southern Italy, by means of the highly informative cox1/trnL/cox2 mitochondrial DNA marker. Overall, phylogenetic analyses confirmed previously identified lineages and taxa, but widened the distribution of the lineage SC to the mainland and of the lineage SF to Spain and Portugal. Results further provided evidence for the synonymy between lineage B and K. italicus. Species delimitation analysis suggested that the three K. flavicollis lineages, as well as K. italicus, can be separate taxa. Data also suggest a possible interspecific hybridization between K. italicus and both K. flavicollis lineages A and SC.
In this study, we isolate and analyse a new set of microsatellite loci for Cattleya walkeriana. Twenty-two primer pairs were screened for C. walkeriana (n = 32) and assessed for their transferability to Cattleya loddigesii (n = 12) and Cattleya nobilior (n = 06). All loci amplified for C. walkeriana; however, for C. loddigesii and C. nobilior, four and five primers, respectively, did not present amplification. The polymorphic loci presented between 2 and 13 alleles per locus for both C. walkeriana and C. loddigesii, with respective averages of 5.1 and 4.2. For C. nobilior, we found between two and five alleles per locus, with an average of 2.6. For C. walkeriana, observed heterozygosity varied from 0.100 to 0.966, whereas expected heterozygosity ranged from 0.097 to 0.900. The observed and expected heterozygosity for C. loddigesii and C. nobilior were also estimated. We found no significant linkage disequilibrium between any pair of loci, and evidence of null alleles at four loci (Cw16, Cw24, Cw30 and Cw31) for C. walkeriana. The combined power to exclude the first parent and combined non-exclusion probability of identity were 0.999 and 2.3 × 10−20, respectively. These new loci can be used in studies of germplasm resources, and assessments of genotypic and genetic diversity and population structure, thus improving the accuracy of such analyses and their applicability in the conservation and protection of these endangered species.
Breeding and larval performance of novel hybrids from reciprocal crosses of Asian catfish Pangasianodon hypophthalmus (Sauvage, 1878) and African catfish Clarias gariepinus (Burchell, 1822) were investigated in this study. Spawning was by hormonal injection of brood fish, artificial fertilization, and incubation in triplicate aquarium tanks (0.5 × 0.5 × 0.5 m3) with continuous aeration. Reciprocal crosses (♀C. gariepinus × ♂P. hypophthalmus and ♀P. hypophthalmus × ♂C. gariepinus) had lower hatchability (≤50%) than their pure siblings (≥75%). Fish from all crosses survived until the juvenile stage but survival at 35 days post hatching (dph) was higher for pure C. gariepinus sib. ♀C. gariepinus × ♂P. hypophthalmus was observed to be less resistant to degradation of water quality than the other crosses, however it had higher body weight compared with the other crosses that showed similar performance. Morphological comparison of surviving juvenile at 35 dph, showed that all ♀P. hypophthalmus × ♂C. gariepinus and 13% of the ♀C. gariepinus × ♂P. hypophthalmus exhibited the very same morphology as that of their maternal parent species, while the other portion of the ♀C. gariepinus × ♂P. hypophthalmus cross exhibited morphological traits that were intermediate between those of both parent species. This study been the first successful attempt to hybridize both species and therefore, laid the groundwork for further studies on the aquaculture potentials of the novel hybrids.
Hybrid parasites may have an increased transmission potential and higher virulence compared to their parental species. Consequently, hybrid detection is critical for disease control. Previous crossing experiments showed that hybrid schistosome eggs have distinct morphotypes. We therefore compared the performance of egg morphology with molecular markers with regard to detecting hybridization in schistosomes. We studied the morphology of 303 terminal-spined eggs, originating from 19 individuals inhabiting a hybrid zone with natural crosses between the human parasite Schistosoma haematobium and the livestock parasite Schistosoma bovis in Senegal. The egg sizes showed a high variability and ranged between 92·4 and 176·4 µm in length and between 35·7 and 93·0 µm in width. No distinct morphotypes were found and all eggs resembled, to varying extent, the typical S. haematobium egg type. However, molecular analyses on the same eggs clearly showed the presence of two distinct partial mitochondrial cox1 profiles, namely S. bovis and S. haematobium, and only a single nuclear ITS rDNA profile (S. haematobium). Therefore, in these particular crosses, egg morphology appears not a good indicator of hybrid ancestry. We conclude by discussing strengths and limitations of molecular methods to detect hybrids in the context of high-throughput screening of field samples.
The European winter moth, Operophtera brumata, is a non-native pest in the Northeastern USA causing defoliation of forest trees and crops such as apples and blueberries. This species is known to hybridize with O. bruceata, the Bruce spanworm, a native species across North America, although it is not known if there are hybrid generations beyond F1. To study winter moth population genetics and hybridization with Bruce spanworm, we developed two sets of genetic markers, single nucleotide polymorphisms (SNPs) and microsatellites, using genomic approaches. Both types of markers were validated using samples from the two species and their hybrids. We identified 1216 SNPs and 24 variable microsatellite loci. From them we developed a subset of 95 species-diagnostic SNPs and ten microsatellite loci that could be used for hybrid identification. We further validated the ten microsatellite loci by screening field collected samples of both species and putative hybrids. In addition to confirming the presence of F1 hybrids reported in previous studies, we found evidence for multi-generation asymmetric hybridization, as suggested by the occurrence of hybrid backcrosses with the winter month, but not with the Bruce spanworm. Laboratory crosses between winter moth females and Bruce spanworm males resulted in a higher proportion of viable eggs than the reciprocal cross, supporting this pattern. We discuss the possible roles of population demographics, sex chromosome genetic incompatibility, and bacterial symbionts as causes of this asymmetrical hybridization and the utility of the developed markers for future studies.
The well-known pathogens of fasciolosis, Fasciola hepatica (Fh) and Fasciola Gigantica (Fg), possess abundant mature sperms in their seminal vesicles, and thus, they reproduce bisexually. On the other hand, aspermic Fasciola flukes reported from Asian countries, which have no sperm in their seminal vesicles, probably reproduce parthenogenetically. The aim of this study was to reveal the origin of aspermic Fasciola flukes. The nuclear single copy markers, phosphoenolpyruvate carboxykinase and DNA polymerase delta, were employed for analysis of Fasciola species from China. The hybrid origin of aspermic Fasciola flukes was strongly suggested by the presence of the Fh/Fg type, which includes DNA fragments of both F. hepatica and F. gigantica. China can be regarded as the cradle of the interspecific hybridization because F. hepatica and F. gigantica were detected in the northern and southern parts of China, respectively, and hybrids flukes were distributed between the habitats of the two species. The Chinese origin was supported by the fact that a larger number of mitochondrial NADH dehydrogenase subunit 1 (nad1) haplotypes was detected in Chinese aspermic Fasciola populations than in aspermic populations from the neighbouring countries. Hereafter, ‘aspermic’ Fasciola flukes should be termed as ‘hybrid’ Fasciola flukes.
A yellow nutsedge biotype (Res) from an Arkansas rice field
has evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides.
The Res biotype previously exhibited cross-resistance to
ALS inhibitors from four chemical families (imidazolinone, pyrimidinyl
benzoate, sulfonylurea, and triazolopyrimidine). Experiments were conducted
to evaluate alternative herbicides (i.e., glyphosate, bentazon, propanil,
quinclorac, and 2,4-D) currently labeled in Arkansas rice–soybean production
systems. Based on the percentage of aboveground dry weight reduction,
control of the yellow nutsedge biotypes with the labeled rate of bentazon,
propanil, quinclorac, and 2,4-D was < 44%. Glyphosate (867 g ae
ha−1) resulted in 68 and > 94% control of the
Res and susceptible yellow nutsedge biotypes,
respectively, at 28 d after treatment. Dose-response studies were conducted
to estimate the efficacy of glyphosate on the Res biotype,
three susceptible yellow nutsedge biotypes, and purple nutsedge. Based on
the dry weights, the Res biotype was ≥ 5- and ≥ 1.3-fold
less responsive to glyphosate compared to the susceptible biotypes and
purple nutsedge, respectively. Differences in absorption and translocation
of radiolabeled glyphosate were observed among the yellow nutsedge biotypes
and purple nutsedge. The susceptible biotype had less
14C-glyphosate radioactivity in the tissues above the treated
leaf and greater radioactivity in tissues below the treated leaf compared to
the Res biotype and purple nutsedge. Reduced translocation
of glyphosate in tissues below the treated leaf of the Res
biotype could be a reason for the lower glyphosate efficacy in the
Res biotype. No amino acid substitution that would
correspond to glyphosate resistance was found in the
5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene of the
Res biotype. However, an amino acid (serine) addition
was detected in the EPSPS gene of the Res biotype; albeit,
it is not believed that this addition contributes to lower efficacy of
glyphosate in this biotype.
Hybridization of parasites is an emerging public health concern in our changing world. Hybridization and introgression in parasites and pathogens can have major impacts on the host and the epidemiology and evolution of disease. Schistosomiasis is a Neglected Tropical Disease of profound medical and veterinary importance across many parts of the world, with the greatest human burden within sub-Saharan Africa. Here we review how early phenotypic identification and recent confirmation through molecular studies on naturally occurring infections, combined with experimental manipulations, have revealed evidence of viable hybridization and introgressions within and between human and animal schistosome species. Environmental and anthropogenic changes in selective pressures following, for instance, new dam constructions, altered agricultural practices, together with mass drug administration programmes, may all be predicted to further impact the availability of suitable definitive and intermediate hosts for schistosomes. It is therefore imperative to understand the distribution and role of such novel zoonotic hybrid schistosomes on host range, drug efficacy, and hence ultimately transmission potential, if we are to achieve and maintain sustainable control.
More than 100 years ago, Japanese knotweed was introduced to North America. Given its vigorous rhizome system and capability to grow from rhizome and stem fragments, it persists and spreads locally, forming monotypic stands. The Japanese knotweed clone originally introduced was a male sterile female clone; thus, early in the invasion, reproduction from seed was not an issue. The implication was that long-distance dispersal was relatively rare. However, recently, widespread hybridization between Japanese knotweed and Sakhalin (giant) knotweed has been reported, with the hybrid species, Bohemian knotweed, forming the majority of knotweed plants in many areas and possessing higher variability than the parent species. The hybrids produce large numbers of wind-dispersed viable seeds that germinate at rates approaching 100% in some populations. As temperatures increase, knotweed is predicted to expand its range farther north and to higher elevations. With the ability to regenerate from vegetative fragments and disperse via seeds, invasive knotweed species are on the move. An arsenal of chemical weapons, the ability to shade out competitors, and the ability to adapt rapidly through epigenetic change makes knotweed a formidable invader. We observed that knotweed species clearly possess 8 of the 12 ideal weed characteristics, with Bohemian knotweed likely exhibiting still more because of prolific seed production. More research is needed to answer pressing questions. How does hybridization affect knotweed epigenetics? Under what conditions might seed production become more frequent? What kind of niche expansion is possible with the increased variability? Given the considerable challenges posed by knotweed species that promise to become even greater with the proliferation and spread of Bohemian ecotypes, only a thoroughly researched, well-informed approach to knotweed management across North America can be successful.
Invasive species with distributions that encompass much of the North American environment often demand a range of management approaches, for several key reasons. Firstly, the North American environment includes a large number of highly variable habitats in terms of climatic, edaphic, and landscape features. Secondly, these regional habitat differences are accentuated by jurisdictions within Canada and the United States, whereby approaches and available resources differ at local, regional, and national scales. Another important consideration is whether an invasive species or complex also possesses genetic variation. All three of these factors render the knotweed complex in North America a highly variable target for management. In this paper we review existing knowledge of the variable nature of knotweed species (Fallopia japonica (Houtt.) Ronse Decr., Fallopia sachalinensis (F. Schmidt ex Maxim) Ronse Decr., and Fallopia × bohemica, (Chrtek and Chrtková) J. P. Bailey in North America, and evaluate how herbicidal, mechanical and biological control measures must account for this genetic variation, as well as accounting for regional differences and the potential northward expansion of knotweed under climate change. The imminent release of the psyllid, Aphalara itadori Shinji as a biological control agent in North America must also navigate regional and genetic differences. Prior European experience dealing with the three knotweed species should prove useful, but additional research is needed to meet the emerging challenge posed by F. × bohemica in North America, including the possibility of glyphosate resistance. Managers also face challenges associated with posttreatment restoration measures. Furthermore, disparities in resources available to address knotweed management across the continent need to be addressed to contain the rapid spread of this highly persistent and adaptable species. Linking practitioners dealing with knotweed “on the ground” with academic research is a crucial step in the process of marshalling all available resources to reduce the rapidly spreading populations of knotweed.
Cattleya walkeriana, one of the most improved Brazilian Cattleyas, is a popular tropical orchid endemic from Brazil and currently endangered. In the present study, for the first time microsatellite markers were developed for C. walkeriana and their transferability was tested for the species C. loddigesii and C. nobilior. The markers were used for genotyping 26 C. walkeriana specimens from different growers and from different levels of improvement. The transferability was successful, with five polymorphic loci transferred to C. loddigesii and six polymorphic loci to C. nobilior. Eight loci were polymorphic, revealing a maximum of two to ten alleles per locus in C. walkeriana and two to four and two to five in C. loddigesii and C. nobilior, respectively. There was no significant linkage disequilibrium in the studied loci. For C. walkeriana, the observed and expected heterozygosities ranged from 0 to 0.963 and from 0.138 to 0.841, respectively. These markers identified polymorphisms and may be used to study the genetic diversity, gene flow or hybridization of these species.
Yellow nutsedge is one of the most problematic weedy sedges in rice–soybean
systems of the Mississippi Delta region. An acetolactate synthase
(ALS)-inhibiting, herbicide-resistant (Res) yellow nutsedge
biotype was recently documented in eastern Arkansas, which showed
intermediary growth habit between yellow nutsedge and purple nutsedge and
also exhibited differential photoperiodic sensitivity to flowering. The
objectives of this study were to: (a) determine variation in reproductive
characteristics of the Res biotype and three susceptible
(Sus) yellow nutsedge biotypes, (b) understand the
influence of photoperiod on growth and reproduction, (c) understand the
potential role of seeds in population establishment, and (d) elucidate the
phylogenetic relationships between the Res yellow nutsedge
biotype and purple nutsedge. Tuber production per plant and tuber weight of
the Res biotype were less than that of the
Sus biotypes. Differences in quantitative traits, such
as shoot and tuber production existed between the Res and
Sus biotypes for photoperiods ranging from 12 to 16 h.
Generally, photoperiods greater than 12 h increased shoot development in all
yellow nutsedge biotypes, with differential responses among the biotypes.
Number of tubers reached the maximum for the Res biotype at
a 14-h photoperiod. Over a 90-d period, inflorescence formation was only
observed in the Res biotype with maximum flowering and seed
production in the 14-h photoperiod. Subsequent tests revealed up to 18% seed
germination, suggesting that seed could also play a role (in addition to
tubers) in the persistence and spread of the Res yellow
nutsedge. Phylogenetic analysis based on ribosomal DNA internal transcribed
spacer (ITS) regions and mitochondrial nad4 gene intergenic
spacer sequences indicated that the Res biotype was more
closely associated with Sus yellow nutsedge biotypes.
Nevertheless, 100% similarity for the nad4 gene sequences
between the Res yellow nutsedge biotype and a reference
purple nutsedge suggests that the Res biotype is likely a
result of hybridization between yellow and purple nutsedges, which perhaps
explains the intermediary growth characteristics observed in the
The future evolution of energy supply technologies strongly depends on (and affects) the
economic and environmental systems, due to the high dependency of this sector on the
availability and cost of fossil fuels, especially on the small regional scale. This paper
aims at presenting the modeling system and preliminary results of a research project
conducted on the scale of Luxembourg to assess the environmental impact of future energy
scenarios for the country, integrating outputs from partial and computable general
equilibrium models within hybrid Life Cycle Assessment (LCA) frameworks. The general
equilibrium model for Luxembourg, LUXGEM, is used to evaluate the economic impacts of
policy decisions and other economic shocks over the time horizon 2006−2030. A techno-economic (partial
equilibrium) model for Luxembourg, ETEM, is used instead to compute operation levels of
various technologies to meet the demand for energy services at the least cost along the
same timeline. The future energy demand and supply are made consistent by coupling ETEM
with LUXGEM so as to have the same macro-economic variables and energy shares driving both
models. The coupling results are then implemented within a set of Environmentally-Extended
Input-Output (EE-IO) models in historical time series to test the feasibility of the
integrated framework and then to assess the environmental impacts of the country.
Accordingly, a disaggregated energy sector was built with the different ETEM technologies
in the EE-IO to allow hybridization with Life Cycle Inventory (LCI) and enrich the process
detail. The results show that the environmental impact slightly decreased overall from
2006 to 2009. Most of the impacts come from some imported commodities (natural gas, used
to produce electricity, and metalliferous ores and metal scrap). The main energy
production technology is the combined-cycle gas turbine plant “Twinerg”, representing
almost 80% of the domestic electricity production in Luxembourg. In the hybrid EE-IO
model, this technology contributes to around 7% of the total impact of the country’s net
consumption. The causes of divergence between ETEM and LUXGEM are also thoroughly
investigated to outline possible strategies of modeling improvements for future assessment
of environmental impacts using EE-IO. Further analyses focus first on the completion of
the models’ coupling and its application to the defined scenarios. Once the coupling is
consistently accomplished, LUXGEM can compute the IO flows from 2010 to 2030, while the
LCI processes in the hybrid system are harmonized with ETEM to represent the future
domestic and imported energy technologies.